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+/* This is auto-generated file. See bpf_helpers_doc.py for details. */
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+
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+/* Forward declarations of BPF structs */
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+struct bpf_fib_lookup;
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+struct bpf_sk_lookup;
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+struct bpf_perf_event_data;
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+struct bpf_perf_event_value;
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+struct bpf_pidns_info;
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+struct bpf_sock;
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+struct bpf_sock_addr;
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+struct bpf_sock_ops;
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+struct bpf_sock_tuple;
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+struct bpf_spin_lock;
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+struct bpf_sysctl;
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+struct bpf_tcp_sock;
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+struct bpf_tunnel_key;
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+struct bpf_xfrm_state;
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+struct pt_regs;
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+struct sk_reuseport_md;
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+struct sockaddr;
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+struct tcphdr;
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+struct seq_file;
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+struct tcp6_sock;
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+struct tcp_sock;
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+struct tcp_timewait_sock;
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+struct tcp_request_sock;
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+struct udp6_sock;
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+struct task_struct;
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+struct __sk_buff;
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+struct sk_msg_md;
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+struct xdp_md;
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+
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+/*
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+ * bpf_map_lookup_elem
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+ *
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+ * Perform a lookup in *map* for an entry associated to *key*.
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+ *
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+ * Returns
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+ * Map value associated to *key*, or **NULL** if no entry was
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+ * found.
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+ */
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+static void *(*bpf_map_lookup_elem)(void *map, const void *key) = (void *) 1;
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+
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+/*
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+ * bpf_map_update_elem
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+ *
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+ * Add or update the value of the entry associated to *key* in
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+ * *map* with *value*. *flags* is one of:
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+ *
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+ * **BPF_NOEXIST**
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+ * The entry for *key* must not exist in the map.
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+ * **BPF_EXIST**
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+ * The entry for *key* must already exist in the map.
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+ * **BPF_ANY**
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+ * No condition on the existence of the entry for *key*.
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+ *
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+ * Flag value **BPF_NOEXIST** cannot be used for maps of types
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+ * **BPF_MAP_TYPE_ARRAY** or **BPF_MAP_TYPE_PERCPU_ARRAY** (all
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+ * elements always exist), the helper would return an error.
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+ *
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+ * Returns
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+ * 0 on success, or a negative error in case of failure.
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+ */
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+static long (*bpf_map_update_elem)(void *map, const void *key, const void *value, __u64 flags) = (void *) 2;
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+
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+/*
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+ * bpf_map_delete_elem
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+ *
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+ * Delete entry with *key* from *map*.
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+ *
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+ * Returns
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+ * 0 on success, or a negative error in case of failure.
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+ */
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+static long (*bpf_map_delete_elem)(void *map, const void *key) = (void *) 3;
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+
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+/*
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+ * bpf_probe_read
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+ *
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+ * For tracing programs, safely attempt to read *size* bytes from
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+ * kernel space address *unsafe_ptr* and store the data in *dst*.
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+ *
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+ * Generally, use **bpf_probe_read_user**\ () or
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+ * **bpf_probe_read_kernel**\ () instead.
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+ *
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+ * Returns
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+ * 0 on success, or a negative error in case of failure.
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+ */
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+static long (*bpf_probe_read)(void *dst, __u32 size, const void *unsafe_ptr) = (void *) 4;
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+
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+/*
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+ * bpf_ktime_get_ns
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+ *
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+ * Return the time elapsed since system boot, in nanoseconds.
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+ * Does not include time the system was suspended.
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+ * See: **clock_gettime**\ (**CLOCK_MONOTONIC**)
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+ *
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+ * Returns
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+ * Current *ktime*.
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+ */
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+static __u64 (*bpf_ktime_get_ns)(void) = (void *) 5;
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+
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+/*
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+ * bpf_trace_printk
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+ *
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+ * This helper is a "printk()-like" facility for debugging. It
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+ * prints a message defined by format *fmt* (of size *fmt_size*)
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+ * to file *\/sys/kernel/debug/tracing/trace* from DebugFS, if
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+ * available. It can take up to three additional **u64**
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+ * arguments (as an eBPF helpers, the total number of arguments is
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+ * limited to five).
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+ *
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+ * Each time the helper is called, it appends a line to the trace.
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+ * Lines are discarded while *\/sys/kernel/debug/tracing/trace* is
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+ * open, use *\/sys/kernel/debug/tracing/trace_pipe* to avoid this.
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+ * The format of the trace is customizable, and the exact output
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+ * one will get depends on the options set in
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+ * *\/sys/kernel/debug/tracing/trace_options* (see also the
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+ * *README* file under the same directory). However, it usually
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+ * defaults to something like:
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+ *
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+ * ::
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+ *
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+ * telnet-470 [001] .N.. 419421.045894: 0x00000001: <formatted msg>
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+ *
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+ * In the above:
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+ *
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+ * * ``telnet`` is the name of the current task.
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+ * * ``470`` is the PID of the current task.
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+ * * ``001`` is the CPU number on which the task is
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+ * running.
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+ * * In ``.N..``, each character refers to a set of
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+ * options (whether irqs are enabled, scheduling
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+ * options, whether hard/softirqs are running, level of
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+ * preempt_disabled respectively). **N** means that
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+ * **TIF_NEED_RESCHED** and **PREEMPT_NEED_RESCHED**
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+ * are set.
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+ * * ``419421.045894`` is a timestamp.
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+ * * ``0x00000001`` is a fake value used by BPF for the
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+ * instruction pointer register.
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+ * * ``<formatted msg>`` is the message formatted with
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+ * *fmt*.
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+ *
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+ * The conversion specifiers supported by *fmt* are similar, but
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+ * more limited than for printk(). They are **%d**, **%i**,
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+ * **%u**, **%x**, **%ld**, **%li**, **%lu**, **%lx**, **%lld**,
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+ * **%lli**, **%llu**, **%llx**, **%p**, **%s**. No modifier (size
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+ * of field, padding with zeroes, etc.) is available, and the
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+ * helper will return **-EINVAL** (but print nothing) if it
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+ * encounters an unknown specifier.
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+ *
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+ * Also, note that **bpf_trace_printk**\ () is slow, and should
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+ * only be used for debugging purposes. For this reason, a notice
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+ * bloc (spanning several lines) is printed to kernel logs and
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+ * states that the helper should not be used "for production use"
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+ * the first time this helper is used (or more precisely, when
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+ * **trace_printk**\ () buffers are allocated). For passing values
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+ * to user space, perf events should be preferred.
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+ *
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+ * Returns
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+ * The number of bytes written to the buffer, or a negative error
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+ * in case of failure.
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+ */
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+static long (*bpf_trace_printk)(const char *fmt, __u32 fmt_size, ...) = (void *) 6;
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+
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+/*
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+ * bpf_get_prandom_u32
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+ *
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+ * Get a pseudo-random number.
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+ *
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+ * From a security point of view, this helper uses its own
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+ * pseudo-random internal state, and cannot be used to infer the
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+ * seed of other random functions in the kernel. However, it is
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+ * essential to note that the generator used by the helper is not
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+ * cryptographically secure.
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+ *
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+ * Returns
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+ * A random 32-bit unsigned value.
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+ */
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+static __u32 (*bpf_get_prandom_u32)(void) = (void *) 7;
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+
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+/*
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+ * bpf_get_smp_processor_id
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+ *
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+ * Get the SMP (symmetric multiprocessing) processor id. Note that
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+ * all programs run with preemption disabled, which means that the
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+ * SMP processor id is stable during all the execution of the
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+ * program.
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+ *
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+ * Returns
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+ * The SMP id of the processor running the program.
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+ */
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+static __u32 (*bpf_get_smp_processor_id)(void) = (void *) 8;
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+
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+/*
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+ * bpf_skb_store_bytes
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+ *
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+ * Store *len* bytes from address *from* into the packet
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+ * associated to *skb*, at *offset*. *flags* are a combination of
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+ * **BPF_F_RECOMPUTE_CSUM** (automatically recompute the
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+ * checksum for the packet after storing the bytes) and
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+ * **BPF_F_INVALIDATE_HASH** (set *skb*\ **->hash**, *skb*\
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+ * **->swhash** and *skb*\ **->l4hash** to 0).
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+ *
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+ * A call to this helper is susceptible to change the underlying
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+ * packet buffer. Therefore, at load time, all checks on pointers
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+ * previously done by the verifier are invalidated and must be
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+ * performed again, if the helper is used in combination with
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+ * direct packet access.
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+ *
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+ * Returns
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+ * 0 on success, or a negative error in case of failure.
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+ */
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+static long (*bpf_skb_store_bytes)(struct __sk_buff *skb, __u32 offset, const void *from, __u32 len, __u64 flags) = (void *) 9;
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+
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+/*
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+ * bpf_l3_csum_replace
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+ *
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+ * Recompute the layer 3 (e.g. IP) checksum for the packet
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+ * associated to *skb*. Computation is incremental, so the helper
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+ * must know the former value of the header field that was
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+ * modified (*from*), the new value of this field (*to*), and the
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+ * number of bytes (2 or 4) for this field, stored in *size*.
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+ * Alternatively, it is possible to store the difference between
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+ * the previous and the new values of the header field in *to*, by
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+ * setting *from* and *size* to 0. For both methods, *offset*
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+ * indicates the location of the IP checksum within the packet.
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+ *
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+ * This helper works in combination with **bpf_csum_diff**\ (),
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+ * which does not update the checksum in-place, but offers more
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+ * flexibility and can handle sizes larger than 2 or 4 for the
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+ * checksum to update.
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+ *
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+ * A call to this helper is susceptible to change the underlying
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+ * packet buffer. Therefore, at load time, all checks on pointers
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+ * previously done by the verifier are invalidated and must be
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+ * performed again, if the helper is used in combination with
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+ * direct packet access.
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+ *
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+ * Returns
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+ * 0 on success, or a negative error in case of failure.
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+ */
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+static long (*bpf_l3_csum_replace)(struct __sk_buff *skb, __u32 offset, __u64 from, __u64 to, __u64 size) = (void *) 10;
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+
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+/*
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+ * bpf_l4_csum_replace
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+ *
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+ * Recompute the layer 4 (e.g. TCP, UDP or ICMP) checksum for the
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+ * packet associated to *skb*. Computation is incremental, so the
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+ * helper must know the former value of the header field that was
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+ * modified (*from*), the new value of this field (*to*), and the
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+ * number of bytes (2 or 4) for this field, stored on the lowest
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+ * four bits of *flags*. Alternatively, it is possible to store
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+ * the difference between the previous and the new values of the
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+ * header field in *to*, by setting *from* and the four lowest
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+ * bits of *flags* to 0. For both methods, *offset* indicates the
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+ * location of the IP checksum within the packet. In addition to
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+ * the size of the field, *flags* can be added (bitwise OR) actual
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+ * flags. With **BPF_F_MARK_MANGLED_0**, a null checksum is left
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+ * untouched (unless **BPF_F_MARK_ENFORCE** is added as well), and
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+ * for updates resulting in a null checksum the value is set to
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+ * **CSUM_MANGLED_0** instead. Flag **BPF_F_PSEUDO_HDR** indicates
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+ * the checksum is to be computed against a pseudo-header.
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+ *
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+ * This helper works in combination with **bpf_csum_diff**\ (),
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+ * which does not update the checksum in-place, but offers more
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+ * flexibility and can handle sizes larger than 2 or 4 for the
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+ * checksum to update.
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+ *
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+ * A call to this helper is susceptible to change the underlying
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+ * packet buffer. Therefore, at load time, all checks on pointers
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+ * previously done by the verifier are invalidated and must be
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+ * performed again, if the helper is used in combination with
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+ * direct packet access.
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+ *
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+ * Returns
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+ * 0 on success, or a negative error in case of failure.
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+ */
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+static long (*bpf_l4_csum_replace)(struct __sk_buff *skb, __u32 offset, __u64 from, __u64 to, __u64 flags) = (void *) 11;
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+
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+/*
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+ * bpf_tail_call
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+ *
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+ * This special helper is used to trigger a "tail call", or in
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+ * other words, to jump into another eBPF program. The same stack
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+ * frame is used (but values on stack and in registers for the
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+ * caller are not accessible to the callee). This mechanism allows
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+ * for program chaining, either for raising the maximum number of
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+ * available eBPF instructions, or to execute given programs in
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+ * conditional blocks. For security reasons, there is an upper
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+ * limit to the number of successive tail calls that can be
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+ * performed.
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+ *
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+ * Upon call of this helper, the program attempts to jump into a
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+ * program referenced at index *index* in *prog_array_map*, a
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+ * special map of type **BPF_MAP_TYPE_PROG_ARRAY**, and passes
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+ * *ctx*, a pointer to the context.
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+ *
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+ * If the call succeeds, the kernel immediately runs the first
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+ * instruction of the new program. This is not a function call,
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+ * and it never returns to the previous program. If the call
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+ * fails, then the helper has no effect, and the caller continues
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+ * to run its subsequent instructions. A call can fail if the
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+ * destination program for the jump does not exist (i.e. *index*
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+ * is superior to the number of entries in *prog_array_map*), or
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+ * if the maximum number of tail calls has been reached for this
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+ * chain of programs. This limit is defined in the kernel by the
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+ * macro **MAX_TAIL_CALL_CNT** (not accessible to user space),
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+ * which is currently set to 32.
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+ *
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+ * Returns
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+ * 0 on success, or a negative error in case of failure.
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+ */
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+static long (*bpf_tail_call)(void *ctx, void *prog_array_map, __u32 index) = (void *) 12;
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+
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+/*
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+ * bpf_clone_redirect
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+ *
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+ * Clone and redirect the packet associated to *skb* to another
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+ * net device of index *ifindex*. Both ingress and egress
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+ * interfaces can be used for redirection. The **BPF_F_INGRESS**
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+ * value in *flags* is used to make the distinction (ingress path
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+ * is selected if the flag is present, egress path otherwise).
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+ * This is the only flag supported for now.
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+ *
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+ * In comparison with **bpf_redirect**\ () helper,
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+ * **bpf_clone_redirect**\ () has the associated cost of
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+ * duplicating the packet buffer, but this can be executed out of
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+ * the eBPF program. Conversely, **bpf_redirect**\ () is more
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+ * efficient, but it is handled through an action code where the
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+ * redirection happens only after the eBPF program has returned.
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+ *
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+ * A call to this helper is susceptible to change the underlying
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+ * packet buffer. Therefore, at load time, all checks on pointers
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+ * previously done by the verifier are invalidated and must be
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+ * performed again, if the helper is used in combination with
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+ * direct packet access.
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+ *
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+ * Returns
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+ * 0 on success, or a negative error in case of failure.
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+ */
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+static long (*bpf_clone_redirect)(struct __sk_buff *skb, __u32 ifindex, __u64 flags) = (void *) 13;
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+
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+/*
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+ * bpf_get_current_pid_tgid
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+ *
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+ *
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+ * Returns
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+ * A 64-bit integer containing the current tgid and pid, and
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+ * created as such:
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+ * *current_task*\ **->tgid << 32 \|**
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+ * *current_task*\ **->pid**.
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+ */
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+static __u64 (*bpf_get_current_pid_tgid)(void) = (void *) 14;
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+
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+/*
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+ * bpf_get_current_uid_gid
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+ *
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+ *
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+ * Returns
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+ * A 64-bit integer containing the current GID and UID, and
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+ * created as such: *current_gid* **<< 32 \|** *current_uid*.
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+ */
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+static __u64 (*bpf_get_current_uid_gid)(void) = (void *) 15;
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+
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+/*
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+ * bpf_get_current_comm
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+ *
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+ * Copy the **comm** attribute of the current task into *buf* of
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+ * *size_of_buf*. The **comm** attribute contains the name of
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+ * the executable (excluding the path) for the current task. The
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+ * *size_of_buf* must be strictly positive. On success, the
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+ * helper makes sure that the *buf* is NUL-terminated. On failure,
|
|
|
+ * it is filled with zeroes.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_get_current_comm)(void *buf, __u32 size_of_buf) = (void *) 16;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_get_cgroup_classid
|
|
|
+ *
|
|
|
+ * Retrieve the classid for the current task, i.e. for the net_cls
|
|
|
+ * cgroup to which *skb* belongs.
|
|
|
+ *
|
|
|
+ * This helper can be used on TC egress path, but not on ingress.
|
|
|
+ *
|
|
|
+ * The net_cls cgroup provides an interface to tag network packets
|
|
|
+ * based on a user-provided identifier for all traffic coming from
|
|
|
+ * the tasks belonging to the related cgroup. See also the related
|
|
|
+ * kernel documentation, available from the Linux sources in file
|
|
|
+ * *Documentation/admin-guide/cgroup-v1/net_cls.rst*.
|
|
|
+ *
|
|
|
+ * The Linux kernel has two versions for cgroups: there are
|
|
|
+ * cgroups v1 and cgroups v2. Both are available to users, who can
|
|
|
+ * use a mixture of them, but note that the net_cls cgroup is for
|
|
|
+ * cgroup v1 only. This makes it incompatible with BPF programs
|
|
|
+ * run on cgroups, which is a cgroup-v2-only feature (a socket can
|
|
|
+ * only hold data for one version of cgroups at a time).
|
|
|
+ *
|
|
|
+ * This helper is only available is the kernel was compiled with
|
|
|
+ * the **CONFIG_CGROUP_NET_CLASSID** configuration option set to
|
|
|
+ * "**y**" or to "**m**".
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * The classid, or 0 for the default unconfigured classid.
|
|
|
+ */
|
|
|
+static __u32 (*bpf_get_cgroup_classid)(struct __sk_buff *skb) = (void *) 17;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_skb_vlan_push
|
|
|
+ *
|
|
|
+ * Push a *vlan_tci* (VLAN tag control information) of protocol
|
|
|
+ * *vlan_proto* to the packet associated to *skb*, then update
|
|
|
+ * the checksum. Note that if *vlan_proto* is different from
|
|
|
+ * **ETH_P_8021Q** and **ETH_P_8021AD**, it is considered to
|
|
|
+ * be **ETH_P_8021Q**.
|
|
|
+ *
|
|
|
+ * A call to this helper is susceptible to change the underlying
|
|
|
+ * packet buffer. Therefore, at load time, all checks on pointers
|
|
|
+ * previously done by the verifier are invalidated and must be
|
|
|
+ * performed again, if the helper is used in combination with
|
|
|
+ * direct packet access.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_skb_vlan_push)(struct __sk_buff *skb, __be16 vlan_proto, __u16 vlan_tci) = (void *) 18;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_skb_vlan_pop
|
|
|
+ *
|
|
|
+ * Pop a VLAN header from the packet associated to *skb*.
|
|
|
+ *
|
|
|
+ * A call to this helper is susceptible to change the underlying
|
|
|
+ * packet buffer. Therefore, at load time, all checks on pointers
|
|
|
+ * previously done by the verifier are invalidated and must be
|
|
|
+ * performed again, if the helper is used in combination with
|
|
|
+ * direct packet access.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_skb_vlan_pop)(struct __sk_buff *skb) = (void *) 19;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_skb_get_tunnel_key
|
|
|
+ *
|
|
|
+ * Get tunnel metadata. This helper takes a pointer *key* to an
|
|
|
+ * empty **struct bpf_tunnel_key** of **size**, that will be
|
|
|
+ * filled with tunnel metadata for the packet associated to *skb*.
|
|
|
+ * The *flags* can be set to **BPF_F_TUNINFO_IPV6**, which
|
|
|
+ * indicates that the tunnel is based on IPv6 protocol instead of
|
|
|
+ * IPv4.
|
|
|
+ *
|
|
|
+ * The **struct bpf_tunnel_key** is an object that generalizes the
|
|
|
+ * principal parameters used by various tunneling protocols into a
|
|
|
+ * single struct. This way, it can be used to easily make a
|
|
|
+ * decision based on the contents of the encapsulation header,
|
|
|
+ * "summarized" in this struct. In particular, it holds the IP
|
|
|
+ * address of the remote end (IPv4 or IPv6, depending on the case)
|
|
|
+ * in *key*\ **->remote_ipv4** or *key*\ **->remote_ipv6**. Also,
|
|
|
+ * this struct exposes the *key*\ **->tunnel_id**, which is
|
|
|
+ * generally mapped to a VNI (Virtual Network Identifier), making
|
|
|
+ * it programmable together with the **bpf_skb_set_tunnel_key**\
|
|
|
+ * () helper.
|
|
|
+ *
|
|
|
+ * Let's imagine that the following code is part of a program
|
|
|
+ * attached to the TC ingress interface, on one end of a GRE
|
|
|
+ * tunnel, and is supposed to filter out all messages coming from
|
|
|
+ * remote ends with IPv4 address other than 10.0.0.1:
|
|
|
+ *
|
|
|
+ * ::
|
|
|
+ *
|
|
|
+ * int ret;
|
|
|
+ * struct bpf_tunnel_key key = {};
|
|
|
+ *
|
|
|
+ * ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
|
|
|
+ * if (ret < 0)
|
|
|
+ * return TC_ACT_SHOT; // drop packet
|
|
|
+ *
|
|
|
+ * if (key.remote_ipv4 != 0x0a000001)
|
|
|
+ * return TC_ACT_SHOT; // drop packet
|
|
|
+ *
|
|
|
+ * return TC_ACT_OK; // accept packet
|
|
|
+ *
|
|
|
+ * This interface can also be used with all encapsulation devices
|
|
|
+ * that can operate in "collect metadata" mode: instead of having
|
|
|
+ * one network device per specific configuration, the "collect
|
|
|
+ * metadata" mode only requires a single device where the
|
|
|
+ * configuration can be extracted from this helper.
|
|
|
+ *
|
|
|
+ * This can be used together with various tunnels such as VXLan,
|
|
|
+ * Geneve, GRE or IP in IP (IPIP).
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_skb_get_tunnel_key)(struct __sk_buff *skb, struct bpf_tunnel_key *key, __u32 size, __u64 flags) = (void *) 20;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_skb_set_tunnel_key
|
|
|
+ *
|
|
|
+ * Populate tunnel metadata for packet associated to *skb.* The
|
|
|
+ * tunnel metadata is set to the contents of *key*, of *size*. The
|
|
|
+ * *flags* can be set to a combination of the following values:
|
|
|
+ *
|
|
|
+ * **BPF_F_TUNINFO_IPV6**
|
|
|
+ * Indicate that the tunnel is based on IPv6 protocol
|
|
|
+ * instead of IPv4.
|
|
|
+ * **BPF_F_ZERO_CSUM_TX**
|
|
|
+ * For IPv4 packets, add a flag to tunnel metadata
|
|
|
+ * indicating that checksum computation should be skipped
|
|
|
+ * and checksum set to zeroes.
|
|
|
+ * **BPF_F_DONT_FRAGMENT**
|
|
|
+ * Add a flag to tunnel metadata indicating that the
|
|
|
+ * packet should not be fragmented.
|
|
|
+ * **BPF_F_SEQ_NUMBER**
|
|
|
+ * Add a flag to tunnel metadata indicating that a
|
|
|
+ * sequence number should be added to tunnel header before
|
|
|
+ * sending the packet. This flag was added for GRE
|
|
|
+ * encapsulation, but might be used with other protocols
|
|
|
+ * as well in the future.
|
|
|
+ *
|
|
|
+ * Here is a typical usage on the transmit path:
|
|
|
+ *
|
|
|
+ * ::
|
|
|
+ *
|
|
|
+ * struct bpf_tunnel_key key;
|
|
|
+ * populate key ...
|
|
|
+ * bpf_skb_set_tunnel_key(skb, &key, sizeof(key), 0);
|
|
|
+ * bpf_clone_redirect(skb, vxlan_dev_ifindex, 0);
|
|
|
+ *
|
|
|
+ * See also the description of the **bpf_skb_get_tunnel_key**\ ()
|
|
|
+ * helper for additional information.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_skb_set_tunnel_key)(struct __sk_buff *skb, struct bpf_tunnel_key *key, __u32 size, __u64 flags) = (void *) 21;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_perf_event_read
|
|
|
+ *
|
|
|
+ * Read the value of a perf event counter. This helper relies on a
|
|
|
+ * *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. The nature of
|
|
|
+ * the perf event counter is selected when *map* is updated with
|
|
|
+ * perf event file descriptors. The *map* is an array whose size
|
|
|
+ * is the number of available CPUs, and each cell contains a value
|
|
|
+ * relative to one CPU. The value to retrieve is indicated by
|
|
|
+ * *flags*, that contains the index of the CPU to look up, masked
|
|
|
+ * with **BPF_F_INDEX_MASK**. Alternatively, *flags* can be set to
|
|
|
+ * **BPF_F_CURRENT_CPU** to indicate that the value for the
|
|
|
+ * current CPU should be retrieved.
|
|
|
+ *
|
|
|
+ * Note that before Linux 4.13, only hardware perf event can be
|
|
|
+ * retrieved.
|
|
|
+ *
|
|
|
+ * Also, be aware that the newer helper
|
|
|
+ * **bpf_perf_event_read_value**\ () is recommended over
|
|
|
+ * **bpf_perf_event_read**\ () in general. The latter has some ABI
|
|
|
+ * quirks where error and counter value are used as a return code
|
|
|
+ * (which is wrong to do since ranges may overlap). This issue is
|
|
|
+ * fixed with **bpf_perf_event_read_value**\ (), which at the same
|
|
|
+ * time provides more features over the **bpf_perf_event_read**\
|
|
|
+ * () interface. Please refer to the description of
|
|
|
+ * **bpf_perf_event_read_value**\ () for details.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * The value of the perf event counter read from the map, or a
|
|
|
+ * negative error code in case of failure.
|
|
|
+ */
|
|
|
+static __u64 (*bpf_perf_event_read)(void *map, __u64 flags) = (void *) 22;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_redirect
|
|
|
+ *
|
|
|
+ * Redirect the packet to another net device of index *ifindex*.
|
|
|
+ * This helper is somewhat similar to **bpf_clone_redirect**\
|
|
|
+ * (), except that the packet is not cloned, which provides
|
|
|
+ * increased performance.
|
|
|
+ *
|
|
|
+ * Except for XDP, both ingress and egress interfaces can be used
|
|
|
+ * for redirection. The **BPF_F_INGRESS** value in *flags* is used
|
|
|
+ * to make the distinction (ingress path is selected if the flag
|
|
|
+ * is present, egress path otherwise). Currently, XDP only
|
|
|
+ * supports redirection to the egress interface, and accepts no
|
|
|
+ * flag at all.
|
|
|
+ *
|
|
|
+ * The same effect can also be attained with the more generic
|
|
|
+ * **bpf_redirect_map**\ (), which uses a BPF map to store the
|
|
|
+ * redirect target instead of providing it directly to the helper.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * For XDP, the helper returns **XDP_REDIRECT** on success or
|
|
|
+ * **XDP_ABORTED** on error. For other program types, the values
|
|
|
+ * are **TC_ACT_REDIRECT** on success or **TC_ACT_SHOT** on
|
|
|
+ * error.
|
|
|
+ */
|
|
|
+static long (*bpf_redirect)(__u32 ifindex, __u64 flags) = (void *) 23;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_get_route_realm
|
|
|
+ *
|
|
|
+ * Retrieve the realm or the route, that is to say the
|
|
|
+ * **tclassid** field of the destination for the *skb*. The
|
|
|
+ * indentifier retrieved is a user-provided tag, similar to the
|
|
|
+ * one used with the net_cls cgroup (see description for
|
|
|
+ * **bpf_get_cgroup_classid**\ () helper), but here this tag is
|
|
|
+ * held by a route (a destination entry), not by a task.
|
|
|
+ *
|
|
|
+ * Retrieving this identifier works with the clsact TC egress hook
|
|
|
+ * (see also **tc-bpf(8)**), or alternatively on conventional
|
|
|
+ * classful egress qdiscs, but not on TC ingress path. In case of
|
|
|
+ * clsact TC egress hook, this has the advantage that, internally,
|
|
|
+ * the destination entry has not been dropped yet in the transmit
|
|
|
+ * path. Therefore, the destination entry does not need to be
|
|
|
+ * artificially held via **netif_keep_dst**\ () for a classful
|
|
|
+ * qdisc until the *skb* is freed.
|
|
|
+ *
|
|
|
+ * This helper is available only if the kernel was compiled with
|
|
|
+ * **CONFIG_IP_ROUTE_CLASSID** configuration option.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * The realm of the route for the packet associated to *skb*, or 0
|
|
|
+ * if none was found.
|
|
|
+ */
|
|
|
+static __u32 (*bpf_get_route_realm)(struct __sk_buff *skb) = (void *) 24;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_perf_event_output
|
|
|
+ *
|
|
|
+ * Write raw *data* blob into a special BPF perf event held by
|
|
|
+ * *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf
|
|
|
+ * event must have the following attributes: **PERF_SAMPLE_RAW**
|
|
|
+ * as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and
|
|
|
+ * **PERF_COUNT_SW_BPF_OUTPUT** as **config**.
|
|
|
+ *
|
|
|
+ * The *flags* are used to indicate the index in *map* for which
|
|
|
+ * the value must be put, masked with **BPF_F_INDEX_MASK**.
|
|
|
+ * Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU**
|
|
|
+ * to indicate that the index of the current CPU core should be
|
|
|
+ * used.
|
|
|
+ *
|
|
|
+ * The value to write, of *size*, is passed through eBPF stack and
|
|
|
+ * pointed by *data*.
|
|
|
+ *
|
|
|
+ * The context of the program *ctx* needs also be passed to the
|
|
|
+ * helper.
|
|
|
+ *
|
|
|
+ * On user space, a program willing to read the values needs to
|
|
|
+ * call **perf_event_open**\ () on the perf event (either for
|
|
|
+ * one or for all CPUs) and to store the file descriptor into the
|
|
|
+ * *map*. This must be done before the eBPF program can send data
|
|
|
+ * into it. An example is available in file
|
|
|
+ * *samples/bpf/trace_output_user.c* in the Linux kernel source
|
|
|
+ * tree (the eBPF program counterpart is in
|
|
|
+ * *samples/bpf/trace_output_kern.c*).
|
|
|
+ *
|
|
|
+ * **bpf_perf_event_output**\ () achieves better performance
|
|
|
+ * than **bpf_trace_printk**\ () for sharing data with user
|
|
|
+ * space, and is much better suitable for streaming data from eBPF
|
|
|
+ * programs.
|
|
|
+ *
|
|
|
+ * Note that this helper is not restricted to tracing use cases
|
|
|
+ * and can be used with programs attached to TC or XDP as well,
|
|
|
+ * where it allows for passing data to user space listeners. Data
|
|
|
+ * can be:
|
|
|
+ *
|
|
|
+ * * Only custom structs,
|
|
|
+ * * Only the packet payload, or
|
|
|
+ * * A combination of both.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_perf_event_output)(void *ctx, void *map, __u64 flags, void *data, __u64 size) = (void *) 25;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_skb_load_bytes
|
|
|
+ *
|
|
|
+ * This helper was provided as an easy way to load data from a
|
|
|
+ * packet. It can be used to load *len* bytes from *offset* from
|
|
|
+ * the packet associated to *skb*, into the buffer pointed by
|
|
|
+ * *to*.
|
|
|
+ *
|
|
|
+ * Since Linux 4.7, usage of this helper has mostly been replaced
|
|
|
+ * by "direct packet access", enabling packet data to be
|
|
|
+ * manipulated with *skb*\ **->data** and *skb*\ **->data_end**
|
|
|
+ * pointing respectively to the first byte of packet data and to
|
|
|
+ * the byte after the last byte of packet data. However, it
|
|
|
+ * remains useful if one wishes to read large quantities of data
|
|
|
+ * at once from a packet into the eBPF stack.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_skb_load_bytes)(const void *skb, __u32 offset, void *to, __u32 len) = (void *) 26;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_get_stackid
|
|
|
+ *
|
|
|
+ * Walk a user or a kernel stack and return its id. To achieve
|
|
|
+ * this, the helper needs *ctx*, which is a pointer to the context
|
|
|
+ * on which the tracing program is executed, and a pointer to a
|
|
|
+ * *map* of type **BPF_MAP_TYPE_STACK_TRACE**.
|
|
|
+ *
|
|
|
+ * The last argument, *flags*, holds the number of stack frames to
|
|
|
+ * skip (from 0 to 255), masked with
|
|
|
+ * **BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set
|
|
|
+ * a combination of the following flags:
|
|
|
+ *
|
|
|
+ * **BPF_F_USER_STACK**
|
|
|
+ * Collect a user space stack instead of a kernel stack.
|
|
|
+ * **BPF_F_FAST_STACK_CMP**
|
|
|
+ * Compare stacks by hash only.
|
|
|
+ * **BPF_F_REUSE_STACKID**
|
|
|
+ * If two different stacks hash into the same *stackid*,
|
|
|
+ * discard the old one.
|
|
|
+ *
|
|
|
+ * The stack id retrieved is a 32 bit long integer handle which
|
|
|
+ * can be further combined with other data (including other stack
|
|
|
+ * ids) and used as a key into maps. This can be useful for
|
|
|
+ * generating a variety of graphs (such as flame graphs or off-cpu
|
|
|
+ * graphs).
|
|
|
+ *
|
|
|
+ * For walking a stack, this helper is an improvement over
|
|
|
+ * **bpf_probe_read**\ (), which can be used with unrolled loops
|
|
|
+ * but is not efficient and consumes a lot of eBPF instructions.
|
|
|
+ * Instead, **bpf_get_stackid**\ () can collect up to
|
|
|
+ * **PERF_MAX_STACK_DEPTH** both kernel and user frames. Note that
|
|
|
+ * this limit can be controlled with the **sysctl** program, and
|
|
|
+ * that it should be manually increased in order to profile long
|
|
|
+ * user stacks (such as stacks for Java programs). To do so, use:
|
|
|
+ *
|
|
|
+ * ::
|
|
|
+ *
|
|
|
+ * # sysctl kernel.perf_event_max_stack=<new value>
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * The positive or null stack id on success, or a negative error
|
|
|
+ * in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_get_stackid)(void *ctx, void *map, __u64 flags) = (void *) 27;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_csum_diff
|
|
|
+ *
|
|
|
+ * Compute a checksum difference, from the raw buffer pointed by
|
|
|
+ * *from*, of length *from_size* (that must be a multiple of 4),
|
|
|
+ * towards the raw buffer pointed by *to*, of size *to_size*
|
|
|
+ * (same remark). An optional *seed* can be added to the value
|
|
|
+ * (this can be cascaded, the seed may come from a previous call
|
|
|
+ * to the helper).
|
|
|
+ *
|
|
|
+ * This is flexible enough to be used in several ways:
|
|
|
+ *
|
|
|
+ * * With *from_size* == 0, *to_size* > 0 and *seed* set to
|
|
|
+ * checksum, it can be used when pushing new data.
|
|
|
+ * * With *from_size* > 0, *to_size* == 0 and *seed* set to
|
|
|
+ * checksum, it can be used when removing data from a packet.
|
|
|
+ * * With *from_size* > 0, *to_size* > 0 and *seed* set to 0, it
|
|
|
+ * can be used to compute a diff. Note that *from_size* and
|
|
|
+ * *to_size* do not need to be equal.
|
|
|
+ *
|
|
|
+ * This helper can be used in combination with
|
|
|
+ * **bpf_l3_csum_replace**\ () and **bpf_l4_csum_replace**\ (), to
|
|
|
+ * which one can feed in the difference computed with
|
|
|
+ * **bpf_csum_diff**\ ().
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * The checksum result, or a negative error code in case of
|
|
|
+ * failure.
|
|
|
+ */
|
|
|
+static __s64 (*bpf_csum_diff)(__be32 *from, __u32 from_size, __be32 *to, __u32 to_size, __wsum seed) = (void *) 28;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_skb_get_tunnel_opt
|
|
|
+ *
|
|
|
+ * Retrieve tunnel options metadata for the packet associated to
|
|
|
+ * *skb*, and store the raw tunnel option data to the buffer *opt*
|
|
|
+ * of *size*.
|
|
|
+ *
|
|
|
+ * This helper can be used with encapsulation devices that can
|
|
|
+ * operate in "collect metadata" mode (please refer to the related
|
|
|
+ * note in the description of **bpf_skb_get_tunnel_key**\ () for
|
|
|
+ * more details). A particular example where this can be used is
|
|
|
+ * in combination with the Geneve encapsulation protocol, where it
|
|
|
+ * allows for pushing (with **bpf_skb_get_tunnel_opt**\ () helper)
|
|
|
+ * and retrieving arbitrary TLVs (Type-Length-Value headers) from
|
|
|
+ * the eBPF program. This allows for full customization of these
|
|
|
+ * headers.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * The size of the option data retrieved.
|
|
|
+ */
|
|
|
+static long (*bpf_skb_get_tunnel_opt)(struct __sk_buff *skb, void *opt, __u32 size) = (void *) 29;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_skb_set_tunnel_opt
|
|
|
+ *
|
|
|
+ * Set tunnel options metadata for the packet associated to *skb*
|
|
|
+ * to the option data contained in the raw buffer *opt* of *size*.
|
|
|
+ *
|
|
|
+ * See also the description of the **bpf_skb_get_tunnel_opt**\ ()
|
|
|
+ * helper for additional information.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_skb_set_tunnel_opt)(struct __sk_buff *skb, void *opt, __u32 size) = (void *) 30;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_skb_change_proto
|
|
|
+ *
|
|
|
+ * Change the protocol of the *skb* to *proto*. Currently
|
|
|
+ * supported are transition from IPv4 to IPv6, and from IPv6 to
|
|
|
+ * IPv4. The helper takes care of the groundwork for the
|
|
|
+ * transition, including resizing the socket buffer. The eBPF
|
|
|
+ * program is expected to fill the new headers, if any, via
|
|
|
+ * **skb_store_bytes**\ () and to recompute the checksums with
|
|
|
+ * **bpf_l3_csum_replace**\ () and **bpf_l4_csum_replace**\
|
|
|
+ * (). The main case for this helper is to perform NAT64
|
|
|
+ * operations out of an eBPF program.
|
|
|
+ *
|
|
|
+ * Internally, the GSO type is marked as dodgy so that headers are
|
|
|
+ * checked and segments are recalculated by the GSO/GRO engine.
|
|
|
+ * The size for GSO target is adapted as well.
|
|
|
+ *
|
|
|
+ * All values for *flags* are reserved for future usage, and must
|
|
|
+ * be left at zero.
|
|
|
+ *
|
|
|
+ * A call to this helper is susceptible to change the underlying
|
|
|
+ * packet buffer. Therefore, at load time, all checks on pointers
|
|
|
+ * previously done by the verifier are invalidated and must be
|
|
|
+ * performed again, if the helper is used in combination with
|
|
|
+ * direct packet access.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_skb_change_proto)(struct __sk_buff *skb, __be16 proto, __u64 flags) = (void *) 31;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_skb_change_type
|
|
|
+ *
|
|
|
+ * Change the packet type for the packet associated to *skb*. This
|
|
|
+ * comes down to setting *skb*\ **->pkt_type** to *type*, except
|
|
|
+ * the eBPF program does not have a write access to *skb*\
|
|
|
+ * **->pkt_type** beside this helper. Using a helper here allows
|
|
|
+ * for graceful handling of errors.
|
|
|
+ *
|
|
|
+ * The major use case is to change incoming *skb*s to
|
|
|
+ * **PACKET_HOST** in a programmatic way instead of having to
|
|
|
+ * recirculate via **redirect**\ (..., **BPF_F_INGRESS**), for
|
|
|
+ * example.
|
|
|
+ *
|
|
|
+ * Note that *type* only allows certain values. At this time, they
|
|
|
+ * are:
|
|
|
+ *
|
|
|
+ * **PACKET_HOST**
|
|
|
+ * Packet is for us.
|
|
|
+ * **PACKET_BROADCAST**
|
|
|
+ * Send packet to all.
|
|
|
+ * **PACKET_MULTICAST**
|
|
|
+ * Send packet to group.
|
|
|
+ * **PACKET_OTHERHOST**
|
|
|
+ * Send packet to someone else.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_skb_change_type)(struct __sk_buff *skb, __u32 type) = (void *) 32;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_skb_under_cgroup
|
|
|
+ *
|
|
|
+ * Check whether *skb* is a descendant of the cgroup2 held by
|
|
|
+ * *map* of type **BPF_MAP_TYPE_CGROUP_ARRAY**, at *index*.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * The return value depends on the result of the test, and can be:
|
|
|
+ *
|
|
|
+ * * 0, if the *skb* failed the cgroup2 descendant test.
|
|
|
+ * * 1, if the *skb* succeeded the cgroup2 descendant test.
|
|
|
+ * * A negative error code, if an error occurred.
|
|
|
+ */
|
|
|
+static long (*bpf_skb_under_cgroup)(struct __sk_buff *skb, void *map, __u32 index) = (void *) 33;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_get_hash_recalc
|
|
|
+ *
|
|
|
+ * Retrieve the hash of the packet, *skb*\ **->hash**. If it is
|
|
|
+ * not set, in particular if the hash was cleared due to mangling,
|
|
|
+ * recompute this hash. Later accesses to the hash can be done
|
|
|
+ * directly with *skb*\ **->hash**.
|
|
|
+ *
|
|
|
+ * Calling **bpf_set_hash_invalid**\ (), changing a packet
|
|
|
+ * prototype with **bpf_skb_change_proto**\ (), or calling
|
|
|
+ * **bpf_skb_store_bytes**\ () with the
|
|
|
+ * **BPF_F_INVALIDATE_HASH** are actions susceptible to clear
|
|
|
+ * the hash and to trigger a new computation for the next call to
|
|
|
+ * **bpf_get_hash_recalc**\ ().
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * The 32-bit hash.
|
|
|
+ */
|
|
|
+static __u32 (*bpf_get_hash_recalc)(struct __sk_buff *skb) = (void *) 34;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_get_current_task
|
|
|
+ *
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * A pointer to the current task struct.
|
|
|
+ */
|
|
|
+static __u64 (*bpf_get_current_task)(void) = (void *) 35;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_probe_write_user
|
|
|
+ *
|
|
|
+ * Attempt in a safe way to write *len* bytes from the buffer
|
|
|
+ * *src* to *dst* in memory. It only works for threads that are in
|
|
|
+ * user context, and *dst* must be a valid user space address.
|
|
|
+ *
|
|
|
+ * This helper should not be used to implement any kind of
|
|
|
+ * security mechanism because of TOC-TOU attacks, but rather to
|
|
|
+ * debug, divert, and manipulate execution of semi-cooperative
|
|
|
+ * processes.
|
|
|
+ *
|
|
|
+ * Keep in mind that this feature is meant for experiments, and it
|
|
|
+ * has a risk of crashing the system and running programs.
|
|
|
+ * Therefore, when an eBPF program using this helper is attached,
|
|
|
+ * a warning including PID and process name is printed to kernel
|
|
|
+ * logs.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_probe_write_user)(void *dst, const void *src, __u32 len) = (void *) 36;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_current_task_under_cgroup
|
|
|
+ *
|
|
|
+ * Check whether the probe is being run is the context of a given
|
|
|
+ * subset of the cgroup2 hierarchy. The cgroup2 to test is held by
|
|
|
+ * *map* of type **BPF_MAP_TYPE_CGROUP_ARRAY**, at *index*.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * The return value depends on the result of the test, and can be:
|
|
|
+ *
|
|
|
+ * * 0, if the *skb* task belongs to the cgroup2.
|
|
|
+ * * 1, if the *skb* task does not belong to the cgroup2.
|
|
|
+ * * A negative error code, if an error occurred.
|
|
|
+ */
|
|
|
+static long (*bpf_current_task_under_cgroup)(void *map, __u32 index) = (void *) 37;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_skb_change_tail
|
|
|
+ *
|
|
|
+ * Resize (trim or grow) the packet associated to *skb* to the
|
|
|
+ * new *len*. The *flags* are reserved for future usage, and must
|
|
|
+ * be left at zero.
|
|
|
+ *
|
|
|
+ * The basic idea is that the helper performs the needed work to
|
|
|
+ * change the size of the packet, then the eBPF program rewrites
|
|
|
+ * the rest via helpers like **bpf_skb_store_bytes**\ (),
|
|
|
+ * **bpf_l3_csum_replace**\ (), **bpf_l3_csum_replace**\ ()
|
|
|
+ * and others. This helper is a slow path utility intended for
|
|
|
+ * replies with control messages. And because it is targeted for
|
|
|
+ * slow path, the helper itself can afford to be slow: it
|
|
|
+ * implicitly linearizes, unclones and drops offloads from the
|
|
|
+ * *skb*.
|
|
|
+ *
|
|
|
+ * A call to this helper is susceptible to change the underlying
|
|
|
+ * packet buffer. Therefore, at load time, all checks on pointers
|
|
|
+ * previously done by the verifier are invalidated and must be
|
|
|
+ * performed again, if the helper is used in combination with
|
|
|
+ * direct packet access.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_skb_change_tail)(struct __sk_buff *skb, __u32 len, __u64 flags) = (void *) 38;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_skb_pull_data
|
|
|
+ *
|
|
|
+ * Pull in non-linear data in case the *skb* is non-linear and not
|
|
|
+ * all of *len* are part of the linear section. Make *len* bytes
|
|
|
+ * from *skb* readable and writable. If a zero value is passed for
|
|
|
+ * *len*, then the whole length of the *skb* is pulled.
|
|
|
+ *
|
|
|
+ * This helper is only needed for reading and writing with direct
|
|
|
+ * packet access.
|
|
|
+ *
|
|
|
+ * For direct packet access, testing that offsets to access
|
|
|
+ * are within packet boundaries (test on *skb*\ **->data_end**) is
|
|
|
+ * susceptible to fail if offsets are invalid, or if the requested
|
|
|
+ * data is in non-linear parts of the *skb*. On failure the
|
|
|
+ * program can just bail out, or in the case of a non-linear
|
|
|
+ * buffer, use a helper to make the data available. The
|
|
|
+ * **bpf_skb_load_bytes**\ () helper is a first solution to access
|
|
|
+ * the data. Another one consists in using **bpf_skb_pull_data**
|
|
|
+ * to pull in once the non-linear parts, then retesting and
|
|
|
+ * eventually access the data.
|
|
|
+ *
|
|
|
+ * At the same time, this also makes sure the *skb* is uncloned,
|
|
|
+ * which is a necessary condition for direct write. As this needs
|
|
|
+ * to be an invariant for the write part only, the verifier
|
|
|
+ * detects writes and adds a prologue that is calling
|
|
|
+ * **bpf_skb_pull_data()** to effectively unclone the *skb* from
|
|
|
+ * the very beginning in case it is indeed cloned.
|
|
|
+ *
|
|
|
+ * A call to this helper is susceptible to change the underlying
|
|
|
+ * packet buffer. Therefore, at load time, all checks on pointers
|
|
|
+ * previously done by the verifier are invalidated and must be
|
|
|
+ * performed again, if the helper is used in combination with
|
|
|
+ * direct packet access.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_skb_pull_data)(struct __sk_buff *skb, __u32 len) = (void *) 39;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_csum_update
|
|
|
+ *
|
|
|
+ * Add the checksum *csum* into *skb*\ **->csum** in case the
|
|
|
+ * driver has supplied a checksum for the entire packet into that
|
|
|
+ * field. Return an error otherwise. This helper is intended to be
|
|
|
+ * used in combination with **bpf_csum_diff**\ (), in particular
|
|
|
+ * when the checksum needs to be updated after data has been
|
|
|
+ * written into the packet through direct packet access.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * The checksum on success, or a negative error code in case of
|
|
|
+ * failure.
|
|
|
+ */
|
|
|
+static __s64 (*bpf_csum_update)(struct __sk_buff *skb, __wsum csum) = (void *) 40;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_set_hash_invalid
|
|
|
+ *
|
|
|
+ * Invalidate the current *skb*\ **->hash**. It can be used after
|
|
|
+ * mangling on headers through direct packet access, in order to
|
|
|
+ * indicate that the hash is outdated and to trigger a
|
|
|
+ * recalculation the next time the kernel tries to access this
|
|
|
+ * hash or when the **bpf_get_hash_recalc**\ () helper is called.
|
|
|
+ *
|
|
|
+ */
|
|
|
+static void (*bpf_set_hash_invalid)(struct __sk_buff *skb) = (void *) 41;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_get_numa_node_id
|
|
|
+ *
|
|
|
+ * Return the id of the current NUMA node. The primary use case
|
|
|
+ * for this helper is the selection of sockets for the local NUMA
|
|
|
+ * node, when the program is attached to sockets using the
|
|
|
+ * **SO_ATTACH_REUSEPORT_EBPF** option (see also **socket(7)**),
|
|
|
+ * but the helper is also available to other eBPF program types,
|
|
|
+ * similarly to **bpf_get_smp_processor_id**\ ().
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * The id of current NUMA node.
|
|
|
+ */
|
|
|
+static long (*bpf_get_numa_node_id)(void) = (void *) 42;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_skb_change_head
|
|
|
+ *
|
|
|
+ * Grows headroom of packet associated to *skb* and adjusts the
|
|
|
+ * offset of the MAC header accordingly, adding *len* bytes of
|
|
|
+ * space. It automatically extends and reallocates memory as
|
|
|
+ * required.
|
|
|
+ *
|
|
|
+ * This helper can be used on a layer 3 *skb* to push a MAC header
|
|
|
+ * for redirection into a layer 2 device.
|
|
|
+ *
|
|
|
+ * All values for *flags* are reserved for future usage, and must
|
|
|
+ * be left at zero.
|
|
|
+ *
|
|
|
+ * A call to this helper is susceptible to change the underlying
|
|
|
+ * packet buffer. Therefore, at load time, all checks on pointers
|
|
|
+ * previously done by the verifier are invalidated and must be
|
|
|
+ * performed again, if the helper is used in combination with
|
|
|
+ * direct packet access.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_skb_change_head)(struct __sk_buff *skb, __u32 len, __u64 flags) = (void *) 43;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_xdp_adjust_head
|
|
|
+ *
|
|
|
+ * Adjust (move) *xdp_md*\ **->data** by *delta* bytes. Note that
|
|
|
+ * it is possible to use a negative value for *delta*. This helper
|
|
|
+ * can be used to prepare the packet for pushing or popping
|
|
|
+ * headers.
|
|
|
+ *
|
|
|
+ * A call to this helper is susceptible to change the underlying
|
|
|
+ * packet buffer. Therefore, at load time, all checks on pointers
|
|
|
+ * previously done by the verifier are invalidated and must be
|
|
|
+ * performed again, if the helper is used in combination with
|
|
|
+ * direct packet access.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_xdp_adjust_head)(struct xdp_md *xdp_md, int delta) = (void *) 44;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_probe_read_str
|
|
|
+ *
|
|
|
+ * Copy a NUL terminated string from an unsafe kernel address
|
|
|
+ * *unsafe_ptr* to *dst*. See **bpf_probe_read_kernel_str**\ () for
|
|
|
+ * more details.
|
|
|
+ *
|
|
|
+ * Generally, use **bpf_probe_read_user_str**\ () or
|
|
|
+ * **bpf_probe_read_kernel_str**\ () instead.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * On success, the strictly positive length of the string,
|
|
|
+ * including the trailing NUL character. On error, a negative
|
|
|
+ * value.
|
|
|
+ */
|
|
|
+static long (*bpf_probe_read_str)(void *dst, __u32 size, const void *unsafe_ptr) = (void *) 45;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_get_socket_cookie
|
|
|
+ *
|
|
|
+ * If the **struct sk_buff** pointed by *skb* has a known socket,
|
|
|
+ * retrieve the cookie (generated by the kernel) of this socket.
|
|
|
+ * If no cookie has been set yet, generate a new cookie. Once
|
|
|
+ * generated, the socket cookie remains stable for the life of the
|
|
|
+ * socket. This helper can be useful for monitoring per socket
|
|
|
+ * networking traffic statistics as it provides a global socket
|
|
|
+ * identifier that can be assumed unique.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * A 8-byte long non-decreasing number on success, or 0 if the
|
|
|
+ * socket field is missing inside *skb*.
|
|
|
+ */
|
|
|
+static __u64 (*bpf_get_socket_cookie)(void *ctx) = (void *) 46;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_get_socket_uid
|
|
|
+ *
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * The owner UID of the socket associated to *skb*. If the socket
|
|
|
+ * is **NULL**, or if it is not a full socket (i.e. if it is a
|
|
|
+ * time-wait or a request socket instead), **overflowuid** value
|
|
|
+ * is returned (note that **overflowuid** might also be the actual
|
|
|
+ * UID value for the socket).
|
|
|
+ */
|
|
|
+static __u32 (*bpf_get_socket_uid)(struct __sk_buff *skb) = (void *) 47;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_set_hash
|
|
|
+ *
|
|
|
+ * Set the full hash for *skb* (set the field *skb*\ **->hash**)
|
|
|
+ * to value *hash*.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0
|
|
|
+ */
|
|
|
+static long (*bpf_set_hash)(struct __sk_buff *skb, __u32 hash) = (void *) 48;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_setsockopt
|
|
|
+ *
|
|
|
+ * Emulate a call to **setsockopt()** on the socket associated to
|
|
|
+ * *bpf_socket*, which must be a full socket. The *level* at
|
|
|
+ * which the option resides and the name *optname* of the option
|
|
|
+ * must be specified, see **setsockopt(2)** for more information.
|
|
|
+ * The option value of length *optlen* is pointed by *optval*.
|
|
|
+ *
|
|
|
+ * *bpf_socket* should be one of the following:
|
|
|
+ *
|
|
|
+ * * **struct bpf_sock_ops** for **BPF_PROG_TYPE_SOCK_OPS**.
|
|
|
+ * * **struct bpf_sock_addr** for **BPF_CGROUP_INET4_CONNECT**
|
|
|
+ * and **BPF_CGROUP_INET6_CONNECT**.
|
|
|
+ *
|
|
|
+ * This helper actually implements a subset of **setsockopt()**.
|
|
|
+ * It supports the following *level*\ s:
|
|
|
+ *
|
|
|
+ * * **SOL_SOCKET**, which supports the following *optname*\ s:
|
|
|
+ * **SO_RCVBUF**, **SO_SNDBUF**, **SO_MAX_PACING_RATE**,
|
|
|
+ * **SO_PRIORITY**, **SO_RCVLOWAT**, **SO_MARK**,
|
|
|
+ * **SO_BINDTODEVICE**, **SO_KEEPALIVE**.
|
|
|
+ * * **IPPROTO_TCP**, which supports the following *optname*\ s:
|
|
|
+ * **TCP_CONGESTION**, **TCP_BPF_IW**,
|
|
|
+ * **TCP_BPF_SNDCWND_CLAMP**, **TCP_SAVE_SYN**,
|
|
|
+ * **TCP_KEEPIDLE**, **TCP_KEEPINTVL**, **TCP_KEEPCNT**,
|
|
|
+ * **TCP_SYNCNT**, **TCP_USER_TIMEOUT**.
|
|
|
+ * * **IPPROTO_IP**, which supports *optname* **IP_TOS**.
|
|
|
+ * * **IPPROTO_IPV6**, which supports *optname* **IPV6_TCLASS**.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_setsockopt)(void *bpf_socket, int level, int optname, void *optval, int optlen) = (void *) 49;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_skb_adjust_room
|
|
|
+ *
|
|
|
+ * Grow or shrink the room for data in the packet associated to
|
|
|
+ * *skb* by *len_diff*, and according to the selected *mode*.
|
|
|
+ *
|
|
|
+ * By default, the helper will reset any offloaded checksum
|
|
|
+ * indicator of the skb to CHECKSUM_NONE. This can be avoided
|
|
|
+ * by the following flag:
|
|
|
+ *
|
|
|
+ * * **BPF_F_ADJ_ROOM_NO_CSUM_RESET**: Do not reset offloaded
|
|
|
+ * checksum data of the skb to CHECKSUM_NONE.
|
|
|
+ *
|
|
|
+ * There are two supported modes at this time:
|
|
|
+ *
|
|
|
+ * * **BPF_ADJ_ROOM_MAC**: Adjust room at the mac layer
|
|
|
+ * (room space is added or removed below the layer 2 header).
|
|
|
+ *
|
|
|
+ * * **BPF_ADJ_ROOM_NET**: Adjust room at the network layer
|
|
|
+ * (room space is added or removed below the layer 3 header).
|
|
|
+ *
|
|
|
+ * The following flags are supported at this time:
|
|
|
+ *
|
|
|
+ * * **BPF_F_ADJ_ROOM_FIXED_GSO**: Do not adjust gso_size.
|
|
|
+ * Adjusting mss in this way is not allowed for datagrams.
|
|
|
+ *
|
|
|
+ * * **BPF_F_ADJ_ROOM_ENCAP_L3_IPV4**,
|
|
|
+ * **BPF_F_ADJ_ROOM_ENCAP_L3_IPV6**:
|
|
|
+ * Any new space is reserved to hold a tunnel header.
|
|
|
+ * Configure skb offsets and other fields accordingly.
|
|
|
+ *
|
|
|
+ * * **BPF_F_ADJ_ROOM_ENCAP_L4_GRE**,
|
|
|
+ * **BPF_F_ADJ_ROOM_ENCAP_L4_UDP**:
|
|
|
+ * Use with ENCAP_L3 flags to further specify the tunnel type.
|
|
|
+ *
|
|
|
+ * * **BPF_F_ADJ_ROOM_ENCAP_L2**\ (*len*):
|
|
|
+ * Use with ENCAP_L3/L4 flags to further specify the tunnel
|
|
|
+ * type; *len* is the length of the inner MAC header.
|
|
|
+ *
|
|
|
+ * A call to this helper is susceptible to change the underlying
|
|
|
+ * packet buffer. Therefore, at load time, all checks on pointers
|
|
|
+ * previously done by the verifier are invalidated and must be
|
|
|
+ * performed again, if the helper is used in combination with
|
|
|
+ * direct packet access.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_skb_adjust_room)(struct __sk_buff *skb, __s32 len_diff, __u32 mode, __u64 flags) = (void *) 50;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_redirect_map
|
|
|
+ *
|
|
|
+ * Redirect the packet to the endpoint referenced by *map* at
|
|
|
+ * index *key*. Depending on its type, this *map* can contain
|
|
|
+ * references to net devices (for forwarding packets through other
|
|
|
+ * ports), or to CPUs (for redirecting XDP frames to another CPU;
|
|
|
+ * but this is only implemented for native XDP (with driver
|
|
|
+ * support) as of this writing).
|
|
|
+ *
|
|
|
+ * The lower two bits of *flags* are used as the return code if
|
|
|
+ * the map lookup fails. This is so that the return value can be
|
|
|
+ * one of the XDP program return codes up to **XDP_TX**, as chosen
|
|
|
+ * by the caller. Any higher bits in the *flags* argument must be
|
|
|
+ * unset.
|
|
|
+ *
|
|
|
+ * See also **bpf_redirect**\ (), which only supports redirecting
|
|
|
+ * to an ifindex, but doesn't require a map to do so.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * **XDP_REDIRECT** on success, or the value of the two lower bits
|
|
|
+ * of the *flags* argument on error.
|
|
|
+ */
|
|
|
+static long (*bpf_redirect_map)(void *map, __u32 key, __u64 flags) = (void *) 51;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_sk_redirect_map
|
|
|
+ *
|
|
|
+ * Redirect the packet to the socket referenced by *map* (of type
|
|
|
+ * **BPF_MAP_TYPE_SOCKMAP**) at index *key*. Both ingress and
|
|
|
+ * egress interfaces can be used for redirection. The
|
|
|
+ * **BPF_F_INGRESS** value in *flags* is used to make the
|
|
|
+ * distinction (ingress path is selected if the flag is present,
|
|
|
+ * egress path otherwise). This is the only flag supported for now.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * **SK_PASS** on success, or **SK_DROP** on error.
|
|
|
+ */
|
|
|
+static long (*bpf_sk_redirect_map)(struct __sk_buff *skb, void *map, __u32 key, __u64 flags) = (void *) 52;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_sock_map_update
|
|
|
+ *
|
|
|
+ * Add an entry to, or update a *map* referencing sockets. The
|
|
|
+ * *skops* is used as a new value for the entry associated to
|
|
|
+ * *key*. *flags* is one of:
|
|
|
+ *
|
|
|
+ * **BPF_NOEXIST**
|
|
|
+ * The entry for *key* must not exist in the map.
|
|
|
+ * **BPF_EXIST**
|
|
|
+ * The entry for *key* must already exist in the map.
|
|
|
+ * **BPF_ANY**
|
|
|
+ * No condition on the existence of the entry for *key*.
|
|
|
+ *
|
|
|
+ * If the *map* has eBPF programs (parser and verdict), those will
|
|
|
+ * be inherited by the socket being added. If the socket is
|
|
|
+ * already attached to eBPF programs, this results in an error.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_sock_map_update)(struct bpf_sock_ops *skops, void *map, void *key, __u64 flags) = (void *) 53;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_xdp_adjust_meta
|
|
|
+ *
|
|
|
+ * Adjust the address pointed by *xdp_md*\ **->data_meta** by
|
|
|
+ * *delta* (which can be positive or negative). Note that this
|
|
|
+ * operation modifies the address stored in *xdp_md*\ **->data**,
|
|
|
+ * so the latter must be loaded only after the helper has been
|
|
|
+ * called.
|
|
|
+ *
|
|
|
+ * The use of *xdp_md*\ **->data_meta** is optional and programs
|
|
|
+ * are not required to use it. The rationale is that when the
|
|
|
+ * packet is processed with XDP (e.g. as DoS filter), it is
|
|
|
+ * possible to push further meta data along with it before passing
|
|
|
+ * to the stack, and to give the guarantee that an ingress eBPF
|
|
|
+ * program attached as a TC classifier on the same device can pick
|
|
|
+ * this up for further post-processing. Since TC works with socket
|
|
|
+ * buffers, it remains possible to set from XDP the **mark** or
|
|
|
+ * **priority** pointers, or other pointers for the socket buffer.
|
|
|
+ * Having this scratch space generic and programmable allows for
|
|
|
+ * more flexibility as the user is free to store whatever meta
|
|
|
+ * data they need.
|
|
|
+ *
|
|
|
+ * A call to this helper is susceptible to change the underlying
|
|
|
+ * packet buffer. Therefore, at load time, all checks on pointers
|
|
|
+ * previously done by the verifier are invalidated and must be
|
|
|
+ * performed again, if the helper is used in combination with
|
|
|
+ * direct packet access.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_xdp_adjust_meta)(struct xdp_md *xdp_md, int delta) = (void *) 54;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_perf_event_read_value
|
|
|
+ *
|
|
|
+ * Read the value of a perf event counter, and store it into *buf*
|
|
|
+ * of size *buf_size*. This helper relies on a *map* of type
|
|
|
+ * **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. The nature of the perf event
|
|
|
+ * counter is selected when *map* is updated with perf event file
|
|
|
+ * descriptors. The *map* is an array whose size is the number of
|
|
|
+ * available CPUs, and each cell contains a value relative to one
|
|
|
+ * CPU. The value to retrieve is indicated by *flags*, that
|
|
|
+ * contains the index of the CPU to look up, masked with
|
|
|
+ * **BPF_F_INDEX_MASK**. Alternatively, *flags* can be set to
|
|
|
+ * **BPF_F_CURRENT_CPU** to indicate that the value for the
|
|
|
+ * current CPU should be retrieved.
|
|
|
+ *
|
|
|
+ * This helper behaves in a way close to
|
|
|
+ * **bpf_perf_event_read**\ () helper, save that instead of
|
|
|
+ * just returning the value observed, it fills the *buf*
|
|
|
+ * structure. This allows for additional data to be retrieved: in
|
|
|
+ * particular, the enabled and running times (in *buf*\
|
|
|
+ * **->enabled** and *buf*\ **->running**, respectively) are
|
|
|
+ * copied. In general, **bpf_perf_event_read_value**\ () is
|
|
|
+ * recommended over **bpf_perf_event_read**\ (), which has some
|
|
|
+ * ABI issues and provides fewer functionalities.
|
|
|
+ *
|
|
|
+ * These values are interesting, because hardware PMU (Performance
|
|
|
+ * Monitoring Unit) counters are limited resources. When there are
|
|
|
+ * more PMU based perf events opened than available counters,
|
|
|
+ * kernel will multiplex these events so each event gets certain
|
|
|
+ * percentage (but not all) of the PMU time. In case that
|
|
|
+ * multiplexing happens, the number of samples or counter value
|
|
|
+ * will not reflect the case compared to when no multiplexing
|
|
|
+ * occurs. This makes comparison between different runs difficult.
|
|
|
+ * Typically, the counter value should be normalized before
|
|
|
+ * comparing to other experiments. The usual normalization is done
|
|
|
+ * as follows.
|
|
|
+ *
|
|
|
+ * ::
|
|
|
+ *
|
|
|
+ * normalized_counter = counter * t_enabled / t_running
|
|
|
+ *
|
|
|
+ * Where t_enabled is the time enabled for event and t_running is
|
|
|
+ * the time running for event since last normalization. The
|
|
|
+ * enabled and running times are accumulated since the perf event
|
|
|
+ * open. To achieve scaling factor between two invocations of an
|
|
|
+ * eBPF program, users can use CPU id as the key (which is
|
|
|
+ * typical for perf array usage model) to remember the previous
|
|
|
+ * value and do the calculation inside the eBPF program.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_perf_event_read_value)(void *map, __u64 flags, struct bpf_perf_event_value *buf, __u32 buf_size) = (void *) 55;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_perf_prog_read_value
|
|
|
+ *
|
|
|
+ * For en eBPF program attached to a perf event, retrieve the
|
|
|
+ * value of the event counter associated to *ctx* and store it in
|
|
|
+ * the structure pointed by *buf* and of size *buf_size*. Enabled
|
|
|
+ * and running times are also stored in the structure (see
|
|
|
+ * description of helper **bpf_perf_event_read_value**\ () for
|
|
|
+ * more details).
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_perf_prog_read_value)(struct bpf_perf_event_data *ctx, struct bpf_perf_event_value *buf, __u32 buf_size) = (void *) 56;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_getsockopt
|
|
|
+ *
|
|
|
+ * Emulate a call to **getsockopt()** on the socket associated to
|
|
|
+ * *bpf_socket*, which must be a full socket. The *level* at
|
|
|
+ * which the option resides and the name *optname* of the option
|
|
|
+ * must be specified, see **getsockopt(2)** for more information.
|
|
|
+ * The retrieved value is stored in the structure pointed by
|
|
|
+ * *opval* and of length *optlen*.
|
|
|
+ *
|
|
|
+ * *bpf_socket* should be one of the following:
|
|
|
+ *
|
|
|
+ * * **struct bpf_sock_ops** for **BPF_PROG_TYPE_SOCK_OPS**.
|
|
|
+ * * **struct bpf_sock_addr** for **BPF_CGROUP_INET4_CONNECT**
|
|
|
+ * and **BPF_CGROUP_INET6_CONNECT**.
|
|
|
+ *
|
|
|
+ * This helper actually implements a subset of **getsockopt()**.
|
|
|
+ * It supports the following *level*\ s:
|
|
|
+ *
|
|
|
+ * * **IPPROTO_TCP**, which supports *optname*
|
|
|
+ * **TCP_CONGESTION**.
|
|
|
+ * * **IPPROTO_IP**, which supports *optname* **IP_TOS**.
|
|
|
+ * * **IPPROTO_IPV6**, which supports *optname* **IPV6_TCLASS**.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_getsockopt)(void *bpf_socket, int level, int optname, void *optval, int optlen) = (void *) 57;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_override_return
|
|
|
+ *
|
|
|
+ * Used for error injection, this helper uses kprobes to override
|
|
|
+ * the return value of the probed function, and to set it to *rc*.
|
|
|
+ * The first argument is the context *regs* on which the kprobe
|
|
|
+ * works.
|
|
|
+ *
|
|
|
+ * This helper works by setting the PC (program counter)
|
|
|
+ * to an override function which is run in place of the original
|
|
|
+ * probed function. This means the probed function is not run at
|
|
|
+ * all. The replacement function just returns with the required
|
|
|
+ * value.
|
|
|
+ *
|
|
|
+ * This helper has security implications, and thus is subject to
|
|
|
+ * restrictions. It is only available if the kernel was compiled
|
|
|
+ * with the **CONFIG_BPF_KPROBE_OVERRIDE** configuration
|
|
|
+ * option, and in this case it only works on functions tagged with
|
|
|
+ * **ALLOW_ERROR_INJECTION** in the kernel code.
|
|
|
+ *
|
|
|
+ * Also, the helper is only available for the architectures having
|
|
|
+ * the CONFIG_FUNCTION_ERROR_INJECTION option. As of this writing,
|
|
|
+ * x86 architecture is the only one to support this feature.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0
|
|
|
+ */
|
|
|
+static long (*bpf_override_return)(struct pt_regs *regs, __u64 rc) = (void *) 58;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_sock_ops_cb_flags_set
|
|
|
+ *
|
|
|
+ * Attempt to set the value of the **bpf_sock_ops_cb_flags** field
|
|
|
+ * for the full TCP socket associated to *bpf_sock_ops* to
|
|
|
+ * *argval*.
|
|
|
+ *
|
|
|
+ * The primary use of this field is to determine if there should
|
|
|
+ * be calls to eBPF programs of type
|
|
|
+ * **BPF_PROG_TYPE_SOCK_OPS** at various points in the TCP
|
|
|
+ * code. A program of the same type can change its value, per
|
|
|
+ * connection and as necessary, when the connection is
|
|
|
+ * established. This field is directly accessible for reading, but
|
|
|
+ * this helper must be used for updates in order to return an
|
|
|
+ * error if an eBPF program tries to set a callback that is not
|
|
|
+ * supported in the current kernel.
|
|
|
+ *
|
|
|
+ * *argval* is a flag array which can combine these flags:
|
|
|
+ *
|
|
|
+ * * **BPF_SOCK_OPS_RTO_CB_FLAG** (retransmission time out)
|
|
|
+ * * **BPF_SOCK_OPS_RETRANS_CB_FLAG** (retransmission)
|
|
|
+ * * **BPF_SOCK_OPS_STATE_CB_FLAG** (TCP state change)
|
|
|
+ * * **BPF_SOCK_OPS_RTT_CB_FLAG** (every RTT)
|
|
|
+ *
|
|
|
+ * Therefore, this function can be used to clear a callback flag by
|
|
|
+ * setting the appropriate bit to zero. e.g. to disable the RTO
|
|
|
+ * callback:
|
|
|
+ *
|
|
|
+ * **bpf_sock_ops_cb_flags_set(bpf_sock,**
|
|
|
+ * **bpf_sock->bpf_sock_ops_cb_flags & ~BPF_SOCK_OPS_RTO_CB_FLAG)**
|
|
|
+ *
|
|
|
+ * Here are some examples of where one could call such eBPF
|
|
|
+ * program:
|
|
|
+ *
|
|
|
+ * * When RTO fires.
|
|
|
+ * * When a packet is retransmitted.
|
|
|
+ * * When the connection terminates.
|
|
|
+ * * When a packet is sent.
|
|
|
+ * * When a packet is received.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * Code **-EINVAL** if the socket is not a full TCP socket;
|
|
|
+ * otherwise, a positive number containing the bits that could not
|
|
|
+ * be set is returned (which comes down to 0 if all bits were set
|
|
|
+ * as required).
|
|
|
+ */
|
|
|
+static long (*bpf_sock_ops_cb_flags_set)(struct bpf_sock_ops *bpf_sock, int argval) = (void *) 59;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_msg_redirect_map
|
|
|
+ *
|
|
|
+ * This helper is used in programs implementing policies at the
|
|
|
+ * socket level. If the message *msg* is allowed to pass (i.e. if
|
|
|
+ * the verdict eBPF program returns **SK_PASS**), redirect it to
|
|
|
+ * the socket referenced by *map* (of type
|
|
|
+ * **BPF_MAP_TYPE_SOCKMAP**) at index *key*. Both ingress and
|
|
|
+ * egress interfaces can be used for redirection. The
|
|
|
+ * **BPF_F_INGRESS** value in *flags* is used to make the
|
|
|
+ * distinction (ingress path is selected if the flag is present,
|
|
|
+ * egress path otherwise). This is the only flag supported for now.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * **SK_PASS** on success, or **SK_DROP** on error.
|
|
|
+ */
|
|
|
+static long (*bpf_msg_redirect_map)(struct sk_msg_md *msg, void *map, __u32 key, __u64 flags) = (void *) 60;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_msg_apply_bytes
|
|
|
+ *
|
|
|
+ * For socket policies, apply the verdict of the eBPF program to
|
|
|
+ * the next *bytes* (number of bytes) of message *msg*.
|
|
|
+ *
|
|
|
+ * For example, this helper can be used in the following cases:
|
|
|
+ *
|
|
|
+ * * A single **sendmsg**\ () or **sendfile**\ () system call
|
|
|
+ * contains multiple logical messages that the eBPF program is
|
|
|
+ * supposed to read and for which it should apply a verdict.
|
|
|
+ * * An eBPF program only cares to read the first *bytes* of a
|
|
|
+ * *msg*. If the message has a large payload, then setting up
|
|
|
+ * and calling the eBPF program repeatedly for all bytes, even
|
|
|
+ * though the verdict is already known, would create unnecessary
|
|
|
+ * overhead.
|
|
|
+ *
|
|
|
+ * When called from within an eBPF program, the helper sets a
|
|
|
+ * counter internal to the BPF infrastructure, that is used to
|
|
|
+ * apply the last verdict to the next *bytes*. If *bytes* is
|
|
|
+ * smaller than the current data being processed from a
|
|
|
+ * **sendmsg**\ () or **sendfile**\ () system call, the first
|
|
|
+ * *bytes* will be sent and the eBPF program will be re-run with
|
|
|
+ * the pointer for start of data pointing to byte number *bytes*
|
|
|
+ * **+ 1**. If *bytes* is larger than the current data being
|
|
|
+ * processed, then the eBPF verdict will be applied to multiple
|
|
|
+ * **sendmsg**\ () or **sendfile**\ () calls until *bytes* are
|
|
|
+ * consumed.
|
|
|
+ *
|
|
|
+ * Note that if a socket closes with the internal counter holding
|
|
|
+ * a non-zero value, this is not a problem because data is not
|
|
|
+ * being buffered for *bytes* and is sent as it is received.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0
|
|
|
+ */
|
|
|
+static long (*bpf_msg_apply_bytes)(struct sk_msg_md *msg, __u32 bytes) = (void *) 61;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_msg_cork_bytes
|
|
|
+ *
|
|
|
+ * For socket policies, prevent the execution of the verdict eBPF
|
|
|
+ * program for message *msg* until *bytes* (byte number) have been
|
|
|
+ * accumulated.
|
|
|
+ *
|
|
|
+ * This can be used when one needs a specific number of bytes
|
|
|
+ * before a verdict can be assigned, even if the data spans
|
|
|
+ * multiple **sendmsg**\ () or **sendfile**\ () calls. The extreme
|
|
|
+ * case would be a user calling **sendmsg**\ () repeatedly with
|
|
|
+ * 1-byte long message segments. Obviously, this is bad for
|
|
|
+ * performance, but it is still valid. If the eBPF program needs
|
|
|
+ * *bytes* bytes to validate a header, this helper can be used to
|
|
|
+ * prevent the eBPF program to be called again until *bytes* have
|
|
|
+ * been accumulated.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0
|
|
|
+ */
|
|
|
+static long (*bpf_msg_cork_bytes)(struct sk_msg_md *msg, __u32 bytes) = (void *) 62;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_msg_pull_data
|
|
|
+ *
|
|
|
+ * For socket policies, pull in non-linear data from user space
|
|
|
+ * for *msg* and set pointers *msg*\ **->data** and *msg*\
|
|
|
+ * **->data_end** to *start* and *end* bytes offsets into *msg*,
|
|
|
+ * respectively.
|
|
|
+ *
|
|
|
+ * If a program of type **BPF_PROG_TYPE_SK_MSG** is run on a
|
|
|
+ * *msg* it can only parse data that the (**data**, **data_end**)
|
|
|
+ * pointers have already consumed. For **sendmsg**\ () hooks this
|
|
|
+ * is likely the first scatterlist element. But for calls relying
|
|
|
+ * on the **sendpage** handler (e.g. **sendfile**\ ()) this will
|
|
|
+ * be the range (**0**, **0**) because the data is shared with
|
|
|
+ * user space and by default the objective is to avoid allowing
|
|
|
+ * user space to modify data while (or after) eBPF verdict is
|
|
|
+ * being decided. This helper can be used to pull in data and to
|
|
|
+ * set the start and end pointer to given values. Data will be
|
|
|
+ * copied if necessary (i.e. if data was not linear and if start
|
|
|
+ * and end pointers do not point to the same chunk).
|
|
|
+ *
|
|
|
+ * A call to this helper is susceptible to change the underlying
|
|
|
+ * packet buffer. Therefore, at load time, all checks on pointers
|
|
|
+ * previously done by the verifier are invalidated and must be
|
|
|
+ * performed again, if the helper is used in combination with
|
|
|
+ * direct packet access.
|
|
|
+ *
|
|
|
+ * All values for *flags* are reserved for future usage, and must
|
|
|
+ * be left at zero.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_msg_pull_data)(struct sk_msg_md *msg, __u32 start, __u32 end, __u64 flags) = (void *) 63;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_bind
|
|
|
+ *
|
|
|
+ * Bind the socket associated to *ctx* to the address pointed by
|
|
|
+ * *addr*, of length *addr_len*. This allows for making outgoing
|
|
|
+ * connection from the desired IP address, which can be useful for
|
|
|
+ * example when all processes inside a cgroup should use one
|
|
|
+ * single IP address on a host that has multiple IP configured.
|
|
|
+ *
|
|
|
+ * This helper works for IPv4 and IPv6, TCP and UDP sockets. The
|
|
|
+ * domain (*addr*\ **->sa_family**) must be **AF_INET** (or
|
|
|
+ * **AF_INET6**). It's advised to pass zero port (**sin_port**
|
|
|
+ * or **sin6_port**) which triggers IP_BIND_ADDRESS_NO_PORT-like
|
|
|
+ * behavior and lets the kernel efficiently pick up an unused
|
|
|
+ * port as long as 4-tuple is unique. Passing non-zero port might
|
|
|
+ * lead to degraded performance.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_bind)(struct bpf_sock_addr *ctx, struct sockaddr *addr, int addr_len) = (void *) 64;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_xdp_adjust_tail
|
|
|
+ *
|
|
|
+ * Adjust (move) *xdp_md*\ **->data_end** by *delta* bytes. It is
|
|
|
+ * possible to both shrink and grow the packet tail.
|
|
|
+ * Shrink done via *delta* being a negative integer.
|
|
|
+ *
|
|
|
+ * A call to this helper is susceptible to change the underlying
|
|
|
+ * packet buffer. Therefore, at load time, all checks on pointers
|
|
|
+ * previously done by the verifier are invalidated and must be
|
|
|
+ * performed again, if the helper is used in combination with
|
|
|
+ * direct packet access.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_xdp_adjust_tail)(struct xdp_md *xdp_md, int delta) = (void *) 65;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_skb_get_xfrm_state
|
|
|
+ *
|
|
|
+ * Retrieve the XFRM state (IP transform framework, see also
|
|
|
+ * **ip-xfrm(8)**) at *index* in XFRM "security path" for *skb*.
|
|
|
+ *
|
|
|
+ * The retrieved value is stored in the **struct bpf_xfrm_state**
|
|
|
+ * pointed by *xfrm_state* and of length *size*.
|
|
|
+ *
|
|
|
+ * All values for *flags* are reserved for future usage, and must
|
|
|
+ * be left at zero.
|
|
|
+ *
|
|
|
+ * This helper is available only if the kernel was compiled with
|
|
|
+ * **CONFIG_XFRM** configuration option.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_skb_get_xfrm_state)(struct __sk_buff *skb, __u32 index, struct bpf_xfrm_state *xfrm_state, __u32 size, __u64 flags) = (void *) 66;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_get_stack
|
|
|
+ *
|
|
|
+ * Return a user or a kernel stack in bpf program provided buffer.
|
|
|
+ * To achieve this, the helper needs *ctx*, which is a pointer
|
|
|
+ * to the context on which the tracing program is executed.
|
|
|
+ * To store the stacktrace, the bpf program provides *buf* with
|
|
|
+ * a nonnegative *size*.
|
|
|
+ *
|
|
|
+ * The last argument, *flags*, holds the number of stack frames to
|
|
|
+ * skip (from 0 to 255), masked with
|
|
|
+ * **BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set
|
|
|
+ * the following flags:
|
|
|
+ *
|
|
|
+ * **BPF_F_USER_STACK**
|
|
|
+ * Collect a user space stack instead of a kernel stack.
|
|
|
+ * **BPF_F_USER_BUILD_ID**
|
|
|
+ * Collect buildid+offset instead of ips for user stack,
|
|
|
+ * only valid if **BPF_F_USER_STACK** is also specified.
|
|
|
+ *
|
|
|
+ * **bpf_get_stack**\ () can collect up to
|
|
|
+ * **PERF_MAX_STACK_DEPTH** both kernel and user frames, subject
|
|
|
+ * to sufficient large buffer size. Note that
|
|
|
+ * this limit can be controlled with the **sysctl** program, and
|
|
|
+ * that it should be manually increased in order to profile long
|
|
|
+ * user stacks (such as stacks for Java programs). To do so, use:
|
|
|
+ *
|
|
|
+ * ::
|
|
|
+ *
|
|
|
+ * # sysctl kernel.perf_event_max_stack=<new value>
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * A non-negative value equal to or less than *size* on success,
|
|
|
+ * or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_get_stack)(void *ctx, void *buf, __u32 size, __u64 flags) = (void *) 67;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_skb_load_bytes_relative
|
|
|
+ *
|
|
|
+ * This helper is similar to **bpf_skb_load_bytes**\ () in that
|
|
|
+ * it provides an easy way to load *len* bytes from *offset*
|
|
|
+ * from the packet associated to *skb*, into the buffer pointed
|
|
|
+ * by *to*. The difference to **bpf_skb_load_bytes**\ () is that
|
|
|
+ * a fifth argument *start_header* exists in order to select a
|
|
|
+ * base offset to start from. *start_header* can be one of:
|
|
|
+ *
|
|
|
+ * **BPF_HDR_START_MAC**
|
|
|
+ * Base offset to load data from is *skb*'s mac header.
|
|
|
+ * **BPF_HDR_START_NET**
|
|
|
+ * Base offset to load data from is *skb*'s network header.
|
|
|
+ *
|
|
|
+ * In general, "direct packet access" is the preferred method to
|
|
|
+ * access packet data, however, this helper is in particular useful
|
|
|
+ * in socket filters where *skb*\ **->data** does not always point
|
|
|
+ * to the start of the mac header and where "direct packet access"
|
|
|
+ * is not available.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_skb_load_bytes_relative)(const void *skb, __u32 offset, void *to, __u32 len, __u32 start_header) = (void *) 68;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_fib_lookup
|
|
|
+ *
|
|
|
+ * Do FIB lookup in kernel tables using parameters in *params*.
|
|
|
+ * If lookup is successful and result shows packet is to be
|
|
|
+ * forwarded, the neighbor tables are searched for the nexthop.
|
|
|
+ * If successful (ie., FIB lookup shows forwarding and nexthop
|
|
|
+ * is resolved), the nexthop address is returned in ipv4_dst
|
|
|
+ * or ipv6_dst based on family, smac is set to mac address of
|
|
|
+ * egress device, dmac is set to nexthop mac address, rt_metric
|
|
|
+ * is set to metric from route (IPv4/IPv6 only), and ifindex
|
|
|
+ * is set to the device index of the nexthop from the FIB lookup.
|
|
|
+ *
|
|
|
+ * *plen* argument is the size of the passed in struct.
|
|
|
+ * *flags* argument can be a combination of one or more of the
|
|
|
+ * following values:
|
|
|
+ *
|
|
|
+ * **BPF_FIB_LOOKUP_DIRECT**
|
|
|
+ * Do a direct table lookup vs full lookup using FIB
|
|
|
+ * rules.
|
|
|
+ * **BPF_FIB_LOOKUP_OUTPUT**
|
|
|
+ * Perform lookup from an egress perspective (default is
|
|
|
+ * ingress).
|
|
|
+ *
|
|
|
+ * *ctx* is either **struct xdp_md** for XDP programs or
|
|
|
+ * **struct sk_buff** tc cls_act programs.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * * < 0 if any input argument is invalid
|
|
|
+ * * 0 on success (packet is forwarded, nexthop neighbor exists)
|
|
|
+ * * > 0 one of **BPF_FIB_LKUP_RET_** codes explaining why the
|
|
|
+ * packet is not forwarded or needs assist from full stack
|
|
|
+ */
|
|
|
+static long (*bpf_fib_lookup)(void *ctx, struct bpf_fib_lookup *params, int plen, __u32 flags) = (void *) 69;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_sock_hash_update
|
|
|
+ *
|
|
|
+ * Add an entry to, or update a sockhash *map* referencing sockets.
|
|
|
+ * The *skops* is used as a new value for the entry associated to
|
|
|
+ * *key*. *flags* is one of:
|
|
|
+ *
|
|
|
+ * **BPF_NOEXIST**
|
|
|
+ * The entry for *key* must not exist in the map.
|
|
|
+ * **BPF_EXIST**
|
|
|
+ * The entry for *key* must already exist in the map.
|
|
|
+ * **BPF_ANY**
|
|
|
+ * No condition on the existence of the entry for *key*.
|
|
|
+ *
|
|
|
+ * If the *map* has eBPF programs (parser and verdict), those will
|
|
|
+ * be inherited by the socket being added. If the socket is
|
|
|
+ * already attached to eBPF programs, this results in an error.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_sock_hash_update)(struct bpf_sock_ops *skops, void *map, void *key, __u64 flags) = (void *) 70;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_msg_redirect_hash
|
|
|
+ *
|
|
|
+ * This helper is used in programs implementing policies at the
|
|
|
+ * socket level. If the message *msg* is allowed to pass (i.e. if
|
|
|
+ * the verdict eBPF program returns **SK_PASS**), redirect it to
|
|
|
+ * the socket referenced by *map* (of type
|
|
|
+ * **BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and
|
|
|
+ * egress interfaces can be used for redirection. The
|
|
|
+ * **BPF_F_INGRESS** value in *flags* is used to make the
|
|
|
+ * distinction (ingress path is selected if the flag is present,
|
|
|
+ * egress path otherwise). This is the only flag supported for now.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * **SK_PASS** on success, or **SK_DROP** on error.
|
|
|
+ */
|
|
|
+static long (*bpf_msg_redirect_hash)(struct sk_msg_md *msg, void *map, void *key, __u64 flags) = (void *) 71;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_sk_redirect_hash
|
|
|
+ *
|
|
|
+ * This helper is used in programs implementing policies at the
|
|
|
+ * skb socket level. If the sk_buff *skb* is allowed to pass (i.e.
|
|
|
+ * if the verdeict eBPF program returns **SK_PASS**), redirect it
|
|
|
+ * to the socket referenced by *map* (of type
|
|
|
+ * **BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and
|
|
|
+ * egress interfaces can be used for redirection. The
|
|
|
+ * **BPF_F_INGRESS** value in *flags* is used to make the
|
|
|
+ * distinction (ingress path is selected if the flag is present,
|
|
|
+ * egress otherwise). This is the only flag supported for now.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * **SK_PASS** on success, or **SK_DROP** on error.
|
|
|
+ */
|
|
|
+static long (*bpf_sk_redirect_hash)(struct __sk_buff *skb, void *map, void *key, __u64 flags) = (void *) 72;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_lwt_push_encap
|
|
|
+ *
|
|
|
+ * Encapsulate the packet associated to *skb* within a Layer 3
|
|
|
+ * protocol header. This header is provided in the buffer at
|
|
|
+ * address *hdr*, with *len* its size in bytes. *type* indicates
|
|
|
+ * the protocol of the header and can be one of:
|
|
|
+ *
|
|
|
+ * **BPF_LWT_ENCAP_SEG6**
|
|
|
+ * IPv6 encapsulation with Segment Routing Header
|
|
|
+ * (**struct ipv6_sr_hdr**). *hdr* only contains the SRH,
|
|
|
+ * the IPv6 header is computed by the kernel.
|
|
|
+ * **BPF_LWT_ENCAP_SEG6_INLINE**
|
|
|
+ * Only works if *skb* contains an IPv6 packet. Insert a
|
|
|
+ * Segment Routing Header (**struct ipv6_sr_hdr**) inside
|
|
|
+ * the IPv6 header.
|
|
|
+ * **BPF_LWT_ENCAP_IP**
|
|
|
+ * IP encapsulation (GRE/GUE/IPIP/etc). The outer header
|
|
|
+ * must be IPv4 or IPv6, followed by zero or more
|
|
|
+ * additional headers, up to **LWT_BPF_MAX_HEADROOM**
|
|
|
+ * total bytes in all prepended headers. Please note that
|
|
|
+ * if **skb_is_gso**\ (*skb*) is true, no more than two
|
|
|
+ * headers can be prepended, and the inner header, if
|
|
|
+ * present, should be either GRE or UDP/GUE.
|
|
|
+ *
|
|
|
+ * **BPF_LWT_ENCAP_SEG6**\ \* types can be called by BPF programs
|
|
|
+ * of type **BPF_PROG_TYPE_LWT_IN**; **BPF_LWT_ENCAP_IP** type can
|
|
|
+ * be called by bpf programs of types **BPF_PROG_TYPE_LWT_IN** and
|
|
|
+ * **BPF_PROG_TYPE_LWT_XMIT**.
|
|
|
+ *
|
|
|
+ * A call to this helper is susceptible to change the underlying
|
|
|
+ * packet buffer. Therefore, at load time, all checks on pointers
|
|
|
+ * previously done by the verifier are invalidated and must be
|
|
|
+ * performed again, if the helper is used in combination with
|
|
|
+ * direct packet access.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_lwt_push_encap)(struct __sk_buff *skb, __u32 type, void *hdr, __u32 len) = (void *) 73;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_lwt_seg6_store_bytes
|
|
|
+ *
|
|
|
+ * Store *len* bytes from address *from* into the packet
|
|
|
+ * associated to *skb*, at *offset*. Only the flags, tag and TLVs
|
|
|
+ * inside the outermost IPv6 Segment Routing Header can be
|
|
|
+ * modified through this helper.
|
|
|
+ *
|
|
|
+ * A call to this helper is susceptible to change the underlying
|
|
|
+ * packet buffer. Therefore, at load time, all checks on pointers
|
|
|
+ * previously done by the verifier are invalidated and must be
|
|
|
+ * performed again, if the helper is used in combination with
|
|
|
+ * direct packet access.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_lwt_seg6_store_bytes)(struct __sk_buff *skb, __u32 offset, const void *from, __u32 len) = (void *) 74;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_lwt_seg6_adjust_srh
|
|
|
+ *
|
|
|
+ * Adjust the size allocated to TLVs in the outermost IPv6
|
|
|
+ * Segment Routing Header contained in the packet associated to
|
|
|
+ * *skb*, at position *offset* by *delta* bytes. Only offsets
|
|
|
+ * after the segments are accepted. *delta* can be as well
|
|
|
+ * positive (growing) as negative (shrinking).
|
|
|
+ *
|
|
|
+ * A call to this helper is susceptible to change the underlying
|
|
|
+ * packet buffer. Therefore, at load time, all checks on pointers
|
|
|
+ * previously done by the verifier are invalidated and must be
|
|
|
+ * performed again, if the helper is used in combination with
|
|
|
+ * direct packet access.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_lwt_seg6_adjust_srh)(struct __sk_buff *skb, __u32 offset, __s32 delta) = (void *) 75;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_lwt_seg6_action
|
|
|
+ *
|
|
|
+ * Apply an IPv6 Segment Routing action of type *action* to the
|
|
|
+ * packet associated to *skb*. Each action takes a parameter
|
|
|
+ * contained at address *param*, and of length *param_len* bytes.
|
|
|
+ * *action* can be one of:
|
|
|
+ *
|
|
|
+ * **SEG6_LOCAL_ACTION_END_X**
|
|
|
+ * End.X action: Endpoint with Layer-3 cross-connect.
|
|
|
+ * Type of *param*: **struct in6_addr**.
|
|
|
+ * **SEG6_LOCAL_ACTION_END_T**
|
|
|
+ * End.T action: Endpoint with specific IPv6 table lookup.
|
|
|
+ * Type of *param*: **int**.
|
|
|
+ * **SEG6_LOCAL_ACTION_END_B6**
|
|
|
+ * End.B6 action: Endpoint bound to an SRv6 policy.
|
|
|
+ * Type of *param*: **struct ipv6_sr_hdr**.
|
|
|
+ * **SEG6_LOCAL_ACTION_END_B6_ENCAP**
|
|
|
+ * End.B6.Encap action: Endpoint bound to an SRv6
|
|
|
+ * encapsulation policy.
|
|
|
+ * Type of *param*: **struct ipv6_sr_hdr**.
|
|
|
+ *
|
|
|
+ * A call to this helper is susceptible to change the underlying
|
|
|
+ * packet buffer. Therefore, at load time, all checks on pointers
|
|
|
+ * previously done by the verifier are invalidated and must be
|
|
|
+ * performed again, if the helper is used in combination with
|
|
|
+ * direct packet access.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_lwt_seg6_action)(struct __sk_buff *skb, __u32 action, void *param, __u32 param_len) = (void *) 76;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_rc_repeat
|
|
|
+ *
|
|
|
+ * This helper is used in programs implementing IR decoding, to
|
|
|
+ * report a successfully decoded repeat key message. This delays
|
|
|
+ * the generation of a key up event for previously generated
|
|
|
+ * key down event.
|
|
|
+ *
|
|
|
+ * Some IR protocols like NEC have a special IR message for
|
|
|
+ * repeating last button, for when a button is held down.
|
|
|
+ *
|
|
|
+ * The *ctx* should point to the lirc sample as passed into
|
|
|
+ * the program.
|
|
|
+ *
|
|
|
+ * This helper is only available is the kernel was compiled with
|
|
|
+ * the **CONFIG_BPF_LIRC_MODE2** configuration option set to
|
|
|
+ * "**y**".
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0
|
|
|
+ */
|
|
|
+static long (*bpf_rc_repeat)(void *ctx) = (void *) 77;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_rc_keydown
|
|
|
+ *
|
|
|
+ * This helper is used in programs implementing IR decoding, to
|
|
|
+ * report a successfully decoded key press with *scancode*,
|
|
|
+ * *toggle* value in the given *protocol*. The scancode will be
|
|
|
+ * translated to a keycode using the rc keymap, and reported as
|
|
|
+ * an input key down event. After a period a key up event is
|
|
|
+ * generated. This period can be extended by calling either
|
|
|
+ * **bpf_rc_keydown**\ () again with the same values, or calling
|
|
|
+ * **bpf_rc_repeat**\ ().
|
|
|
+ *
|
|
|
+ * Some protocols include a toggle bit, in case the button was
|
|
|
+ * released and pressed again between consecutive scancodes.
|
|
|
+ *
|
|
|
+ * The *ctx* should point to the lirc sample as passed into
|
|
|
+ * the program.
|
|
|
+ *
|
|
|
+ * The *protocol* is the decoded protocol number (see
|
|
|
+ * **enum rc_proto** for some predefined values).
|
|
|
+ *
|
|
|
+ * This helper is only available is the kernel was compiled with
|
|
|
+ * the **CONFIG_BPF_LIRC_MODE2** configuration option set to
|
|
|
+ * "**y**".
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0
|
|
|
+ */
|
|
|
+static long (*bpf_rc_keydown)(void *ctx, __u32 protocol, __u64 scancode, __u32 toggle) = (void *) 78;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_skb_cgroup_id
|
|
|
+ *
|
|
|
+ * Return the cgroup v2 id of the socket associated with the *skb*.
|
|
|
+ * This is roughly similar to the **bpf_get_cgroup_classid**\ ()
|
|
|
+ * helper for cgroup v1 by providing a tag resp. identifier that
|
|
|
+ * can be matched on or used for map lookups e.g. to implement
|
|
|
+ * policy. The cgroup v2 id of a given path in the hierarchy is
|
|
|
+ * exposed in user space through the f_handle API in order to get
|
|
|
+ * to the same 64-bit id.
|
|
|
+ *
|
|
|
+ * This helper can be used on TC egress path, but not on ingress,
|
|
|
+ * and is available only if the kernel was compiled with the
|
|
|
+ * **CONFIG_SOCK_CGROUP_DATA** configuration option.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * The id is returned or 0 in case the id could not be retrieved.
|
|
|
+ */
|
|
|
+static __u64 (*bpf_skb_cgroup_id)(struct __sk_buff *skb) = (void *) 79;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_get_current_cgroup_id
|
|
|
+ *
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * A 64-bit integer containing the current cgroup id based
|
|
|
+ * on the cgroup within which the current task is running.
|
|
|
+ */
|
|
|
+static __u64 (*bpf_get_current_cgroup_id)(void) = (void *) 80;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_get_local_storage
|
|
|
+ *
|
|
|
+ * Get the pointer to the local storage area.
|
|
|
+ * The type and the size of the local storage is defined
|
|
|
+ * by the *map* argument.
|
|
|
+ * The *flags* meaning is specific for each map type,
|
|
|
+ * and has to be 0 for cgroup local storage.
|
|
|
+ *
|
|
|
+ * Depending on the BPF program type, a local storage area
|
|
|
+ * can be shared between multiple instances of the BPF program,
|
|
|
+ * running simultaneously.
|
|
|
+ *
|
|
|
+ * A user should care about the synchronization by himself.
|
|
|
+ * For example, by using the **BPF_STX_XADD** instruction to alter
|
|
|
+ * the shared data.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * A pointer to the local storage area.
|
|
|
+ */
|
|
|
+static void *(*bpf_get_local_storage)(void *map, __u64 flags) = (void *) 81;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_sk_select_reuseport
|
|
|
+ *
|
|
|
+ * Select a **SO_REUSEPORT** socket from a
|
|
|
+ * **BPF_MAP_TYPE_REUSEPORT_ARRAY** *map*.
|
|
|
+ * It checks the selected socket is matching the incoming
|
|
|
+ * request in the socket buffer.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_sk_select_reuseport)(struct sk_reuseport_md *reuse, void *map, void *key, __u64 flags) = (void *) 82;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_skb_ancestor_cgroup_id
|
|
|
+ *
|
|
|
+ * Return id of cgroup v2 that is ancestor of cgroup associated
|
|
|
+ * with the *skb* at the *ancestor_level*. The root cgroup is at
|
|
|
+ * *ancestor_level* zero and each step down the hierarchy
|
|
|
+ * increments the level. If *ancestor_level* == level of cgroup
|
|
|
+ * associated with *skb*, then return value will be same as that
|
|
|
+ * of **bpf_skb_cgroup_id**\ ().
|
|
|
+ *
|
|
|
+ * The helper is useful to implement policies based on cgroups
|
|
|
+ * that are upper in hierarchy than immediate cgroup associated
|
|
|
+ * with *skb*.
|
|
|
+ *
|
|
|
+ * The format of returned id and helper limitations are same as in
|
|
|
+ * **bpf_skb_cgroup_id**\ ().
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * The id is returned or 0 in case the id could not be retrieved.
|
|
|
+ */
|
|
|
+static __u64 (*bpf_skb_ancestor_cgroup_id)(struct __sk_buff *skb, int ancestor_level) = (void *) 83;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_sk_lookup_tcp
|
|
|
+ *
|
|
|
+ * Look for TCP socket matching *tuple*, optionally in a child
|
|
|
+ * network namespace *netns*. The return value must be checked,
|
|
|
+ * and if non-**NULL**, released via **bpf_sk_release**\ ().
|
|
|
+ *
|
|
|
+ * The *ctx* should point to the context of the program, such as
|
|
|
+ * the skb or socket (depending on the hook in use). This is used
|
|
|
+ * to determine the base network namespace for the lookup.
|
|
|
+ *
|
|
|
+ * *tuple_size* must be one of:
|
|
|
+ *
|
|
|
+ * **sizeof**\ (*tuple*\ **->ipv4**)
|
|
|
+ * Look for an IPv4 socket.
|
|
|
+ * **sizeof**\ (*tuple*\ **->ipv6**)
|
|
|
+ * Look for an IPv6 socket.
|
|
|
+ *
|
|
|
+ * If the *netns* is a negative signed 32-bit integer, then the
|
|
|
+ * socket lookup table in the netns associated with the *ctx*
|
|
|
+ * will be used. For the TC hooks, this is the netns of the device
|
|
|
+ * in the skb. For socket hooks, this is the netns of the socket.
|
|
|
+ * If *netns* is any other signed 32-bit value greater than or
|
|
|
+ * equal to zero then it specifies the ID of the netns relative to
|
|
|
+ * the netns associated with the *ctx*. *netns* values beyond the
|
|
|
+ * range of 32-bit integers are reserved for future use.
|
|
|
+ *
|
|
|
+ * All values for *flags* are reserved for future usage, and must
|
|
|
+ * be left at zero.
|
|
|
+ *
|
|
|
+ * This helper is available only if the kernel was compiled with
|
|
|
+ * **CONFIG_NET** configuration option.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * Pointer to **struct bpf_sock**, or **NULL** in case of failure.
|
|
|
+ * For sockets with reuseport option, the **struct bpf_sock**
|
|
|
+ * result is from *reuse*\ **->socks**\ [] using the hash of the
|
|
|
+ * tuple.
|
|
|
+ */
|
|
|
+static struct bpf_sock *(*bpf_sk_lookup_tcp)(void *ctx, struct bpf_sock_tuple *tuple, __u32 tuple_size, __u64 netns, __u64 flags) = (void *) 84;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_sk_lookup_udp
|
|
|
+ *
|
|
|
+ * Look for UDP socket matching *tuple*, optionally in a child
|
|
|
+ * network namespace *netns*. The return value must be checked,
|
|
|
+ * and if non-**NULL**, released via **bpf_sk_release**\ ().
|
|
|
+ *
|
|
|
+ * The *ctx* should point to the context of the program, such as
|
|
|
+ * the skb or socket (depending on the hook in use). This is used
|
|
|
+ * to determine the base network namespace for the lookup.
|
|
|
+ *
|
|
|
+ * *tuple_size* must be one of:
|
|
|
+ *
|
|
|
+ * **sizeof**\ (*tuple*\ **->ipv4**)
|
|
|
+ * Look for an IPv4 socket.
|
|
|
+ * **sizeof**\ (*tuple*\ **->ipv6**)
|
|
|
+ * Look for an IPv6 socket.
|
|
|
+ *
|
|
|
+ * If the *netns* is a negative signed 32-bit integer, then the
|
|
|
+ * socket lookup table in the netns associated with the *ctx*
|
|
|
+ * will be used. For the TC hooks, this is the netns of the device
|
|
|
+ * in the skb. For socket hooks, this is the netns of the socket.
|
|
|
+ * If *netns* is any other signed 32-bit value greater than or
|
|
|
+ * equal to zero then it specifies the ID of the netns relative to
|
|
|
+ * the netns associated with the *ctx*. *netns* values beyond the
|
|
|
+ * range of 32-bit integers are reserved for future use.
|
|
|
+ *
|
|
|
+ * All values for *flags* are reserved for future usage, and must
|
|
|
+ * be left at zero.
|
|
|
+ *
|
|
|
+ * This helper is available only if the kernel was compiled with
|
|
|
+ * **CONFIG_NET** configuration option.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * Pointer to **struct bpf_sock**, or **NULL** in case of failure.
|
|
|
+ * For sockets with reuseport option, the **struct bpf_sock**
|
|
|
+ * result is from *reuse*\ **->socks**\ [] using the hash of the
|
|
|
+ * tuple.
|
|
|
+ */
|
|
|
+static struct bpf_sock *(*bpf_sk_lookup_udp)(void *ctx, struct bpf_sock_tuple *tuple, __u32 tuple_size, __u64 netns, __u64 flags) = (void *) 85;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_sk_release
|
|
|
+ *
|
|
|
+ * Release the reference held by *sock*. *sock* must be a
|
|
|
+ * non-**NULL** pointer that was returned from
|
|
|
+ * **bpf_sk_lookup_xxx**\ ().
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_sk_release)(struct bpf_sock *sock) = (void *) 86;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_map_push_elem
|
|
|
+ *
|
|
|
+ * Push an element *value* in *map*. *flags* is one of:
|
|
|
+ *
|
|
|
+ * **BPF_EXIST**
|
|
|
+ * If the queue/stack is full, the oldest element is
|
|
|
+ * removed to make room for this.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_map_push_elem)(void *map, const void *value, __u64 flags) = (void *) 87;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_map_pop_elem
|
|
|
+ *
|
|
|
+ * Pop an element from *map*.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_map_pop_elem)(void *map, void *value) = (void *) 88;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_map_peek_elem
|
|
|
+ *
|
|
|
+ * Get an element from *map* without removing it.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_map_peek_elem)(void *map, void *value) = (void *) 89;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_msg_push_data
|
|
|
+ *
|
|
|
+ * For socket policies, insert *len* bytes into *msg* at offset
|
|
|
+ * *start*.
|
|
|
+ *
|
|
|
+ * If a program of type **BPF_PROG_TYPE_SK_MSG** is run on a
|
|
|
+ * *msg* it may want to insert metadata or options into the *msg*.
|
|
|
+ * This can later be read and used by any of the lower layer BPF
|
|
|
+ * hooks.
|
|
|
+ *
|
|
|
+ * This helper may fail if under memory pressure (a malloc
|
|
|
+ * fails) in these cases BPF programs will get an appropriate
|
|
|
+ * error and BPF programs will need to handle them.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_msg_push_data)(struct sk_msg_md *msg, __u32 start, __u32 len, __u64 flags) = (void *) 90;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_msg_pop_data
|
|
|
+ *
|
|
|
+ * Will remove *len* bytes from a *msg* starting at byte *start*.
|
|
|
+ * This may result in **ENOMEM** errors under certain situations if
|
|
|
+ * an allocation and copy are required due to a full ring buffer.
|
|
|
+ * However, the helper will try to avoid doing the allocation
|
|
|
+ * if possible. Other errors can occur if input parameters are
|
|
|
+ * invalid either due to *start* byte not being valid part of *msg*
|
|
|
+ * payload and/or *pop* value being to large.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_msg_pop_data)(struct sk_msg_md *msg, __u32 start, __u32 len, __u64 flags) = (void *) 91;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_rc_pointer_rel
|
|
|
+ *
|
|
|
+ * This helper is used in programs implementing IR decoding, to
|
|
|
+ * report a successfully decoded pointer movement.
|
|
|
+ *
|
|
|
+ * The *ctx* should point to the lirc sample as passed into
|
|
|
+ * the program.
|
|
|
+ *
|
|
|
+ * This helper is only available is the kernel was compiled with
|
|
|
+ * the **CONFIG_BPF_LIRC_MODE2** configuration option set to
|
|
|
+ * "**y**".
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0
|
|
|
+ */
|
|
|
+static long (*bpf_rc_pointer_rel)(void *ctx, __s32 rel_x, __s32 rel_y) = (void *) 92;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_spin_lock
|
|
|
+ *
|
|
|
+ * Acquire a spinlock represented by the pointer *lock*, which is
|
|
|
+ * stored as part of a value of a map. Taking the lock allows to
|
|
|
+ * safely update the rest of the fields in that value. The
|
|
|
+ * spinlock can (and must) later be released with a call to
|
|
|
+ * **bpf_spin_unlock**\ (\ *lock*\ ).
|
|
|
+ *
|
|
|
+ * Spinlocks in BPF programs come with a number of restrictions
|
|
|
+ * and constraints:
|
|
|
+ *
|
|
|
+ * * **bpf_spin_lock** objects are only allowed inside maps of
|
|
|
+ * types **BPF_MAP_TYPE_HASH** and **BPF_MAP_TYPE_ARRAY** (this
|
|
|
+ * list could be extended in the future).
|
|
|
+ * * BTF description of the map is mandatory.
|
|
|
+ * * The BPF program can take ONE lock at a time, since taking two
|
|
|
+ * or more could cause dead locks.
|
|
|
+ * * Only one **struct bpf_spin_lock** is allowed per map element.
|
|
|
+ * * When the lock is taken, calls (either BPF to BPF or helpers)
|
|
|
+ * are not allowed.
|
|
|
+ * * The **BPF_LD_ABS** and **BPF_LD_IND** instructions are not
|
|
|
+ * allowed inside a spinlock-ed region.
|
|
|
+ * * The BPF program MUST call **bpf_spin_unlock**\ () to release
|
|
|
+ * the lock, on all execution paths, before it returns.
|
|
|
+ * * The BPF program can access **struct bpf_spin_lock** only via
|
|
|
+ * the **bpf_spin_lock**\ () and **bpf_spin_unlock**\ ()
|
|
|
+ * helpers. Loading or storing data into the **struct
|
|
|
+ * bpf_spin_lock** *lock*\ **;** field of a map is not allowed.
|
|
|
+ * * To use the **bpf_spin_lock**\ () helper, the BTF description
|
|
|
+ * of the map value must be a struct and have **struct
|
|
|
+ * bpf_spin_lock** *anyname*\ **;** field at the top level.
|
|
|
+ * Nested lock inside another struct is not allowed.
|
|
|
+ * * The **struct bpf_spin_lock** *lock* field in a map value must
|
|
|
+ * be aligned on a multiple of 4 bytes in that value.
|
|
|
+ * * Syscall with command **BPF_MAP_LOOKUP_ELEM** does not copy
|
|
|
+ * the **bpf_spin_lock** field to user space.
|
|
|
+ * * Syscall with command **BPF_MAP_UPDATE_ELEM**, or update from
|
|
|
+ * a BPF program, do not update the **bpf_spin_lock** field.
|
|
|
+ * * **bpf_spin_lock** cannot be on the stack or inside a
|
|
|
+ * networking packet (it can only be inside of a map values).
|
|
|
+ * * **bpf_spin_lock** is available to root only.
|
|
|
+ * * Tracing programs and socket filter programs cannot use
|
|
|
+ * **bpf_spin_lock**\ () due to insufficient preemption checks
|
|
|
+ * (but this may change in the future).
|
|
|
+ * * **bpf_spin_lock** is not allowed in inner maps of map-in-map.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0
|
|
|
+ */
|
|
|
+static long (*bpf_spin_lock)(struct bpf_spin_lock *lock) = (void *) 93;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_spin_unlock
|
|
|
+ *
|
|
|
+ * Release the *lock* previously locked by a call to
|
|
|
+ * **bpf_spin_lock**\ (\ *lock*\ ).
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0
|
|
|
+ */
|
|
|
+static long (*bpf_spin_unlock)(struct bpf_spin_lock *lock) = (void *) 94;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_sk_fullsock
|
|
|
+ *
|
|
|
+ * This helper gets a **struct bpf_sock** pointer such
|
|
|
+ * that all the fields in this **bpf_sock** can be accessed.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * A **struct bpf_sock** pointer on success, or **NULL** in
|
|
|
+ * case of failure.
|
|
|
+ */
|
|
|
+static struct bpf_sock *(*bpf_sk_fullsock)(struct bpf_sock *sk) = (void *) 95;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_tcp_sock
|
|
|
+ *
|
|
|
+ * This helper gets a **struct bpf_tcp_sock** pointer from a
|
|
|
+ * **struct bpf_sock** pointer.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * A **struct bpf_tcp_sock** pointer on success, or **NULL** in
|
|
|
+ * case of failure.
|
|
|
+ */
|
|
|
+static struct bpf_tcp_sock *(*bpf_tcp_sock)(struct bpf_sock *sk) = (void *) 96;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_skb_ecn_set_ce
|
|
|
+ *
|
|
|
+ * Set ECN (Explicit Congestion Notification) field of IP header
|
|
|
+ * to **CE** (Congestion Encountered) if current value is **ECT**
|
|
|
+ * (ECN Capable Transport). Otherwise, do nothing. Works with IPv6
|
|
|
+ * and IPv4.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 1 if the **CE** flag is set (either by the current helper call
|
|
|
+ * or because it was already present), 0 if it is not set.
|
|
|
+ */
|
|
|
+static long (*bpf_skb_ecn_set_ce)(struct __sk_buff *skb) = (void *) 97;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_get_listener_sock
|
|
|
+ *
|
|
|
+ * Return a **struct bpf_sock** pointer in **TCP_LISTEN** state.
|
|
|
+ * **bpf_sk_release**\ () is unnecessary and not allowed.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * A **struct bpf_sock** pointer on success, or **NULL** in
|
|
|
+ * case of failure.
|
|
|
+ */
|
|
|
+static struct bpf_sock *(*bpf_get_listener_sock)(struct bpf_sock *sk) = (void *) 98;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_skc_lookup_tcp
|
|
|
+ *
|
|
|
+ * Look for TCP socket matching *tuple*, optionally in a child
|
|
|
+ * network namespace *netns*. The return value must be checked,
|
|
|
+ * and if non-**NULL**, released via **bpf_sk_release**\ ().
|
|
|
+ *
|
|
|
+ * This function is identical to **bpf_sk_lookup_tcp**\ (), except
|
|
|
+ * that it also returns timewait or request sockets. Use
|
|
|
+ * **bpf_sk_fullsock**\ () or **bpf_tcp_sock**\ () to access the
|
|
|
+ * full structure.
|
|
|
+ *
|
|
|
+ * This helper is available only if the kernel was compiled with
|
|
|
+ * **CONFIG_NET** configuration option.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * Pointer to **struct bpf_sock**, or **NULL** in case of failure.
|
|
|
+ * For sockets with reuseport option, the **struct bpf_sock**
|
|
|
+ * result is from *reuse*\ **->socks**\ [] using the hash of the
|
|
|
+ * tuple.
|
|
|
+ */
|
|
|
+static struct bpf_sock *(*bpf_skc_lookup_tcp)(void *ctx, struct bpf_sock_tuple *tuple, __u32 tuple_size, __u64 netns, __u64 flags) = (void *) 99;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_tcp_check_syncookie
|
|
|
+ *
|
|
|
+ * Check whether *iph* and *th* contain a valid SYN cookie ACK for
|
|
|
+ * the listening socket in *sk*.
|
|
|
+ *
|
|
|
+ * *iph* points to the start of the IPv4 or IPv6 header, while
|
|
|
+ * *iph_len* contains **sizeof**\ (**struct iphdr**) or
|
|
|
+ * **sizeof**\ (**struct ip6hdr**).
|
|
|
+ *
|
|
|
+ * *th* points to the start of the TCP header, while *th_len*
|
|
|
+ * contains **sizeof**\ (**struct tcphdr**).
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 if *iph* and *th* are a valid SYN cookie ACK, or a negative
|
|
|
+ * error otherwise.
|
|
|
+ */
|
|
|
+static long (*bpf_tcp_check_syncookie)(struct bpf_sock *sk, void *iph, __u32 iph_len, struct tcphdr *th, __u32 th_len) = (void *) 100;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_sysctl_get_name
|
|
|
+ *
|
|
|
+ * Get name of sysctl in /proc/sys/ and copy it into provided by
|
|
|
+ * program buffer *buf* of size *buf_len*.
|
|
|
+ *
|
|
|
+ * The buffer is always NUL terminated, unless it's zero-sized.
|
|
|
+ *
|
|
|
+ * If *flags* is zero, full name (e.g. "net/ipv4/tcp_mem") is
|
|
|
+ * copied. Use **BPF_F_SYSCTL_BASE_NAME** flag to copy base name
|
|
|
+ * only (e.g. "tcp_mem").
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * Number of character copied (not including the trailing NUL).
|
|
|
+ *
|
|
|
+ * **-E2BIG** if the buffer wasn't big enough (*buf* will contain
|
|
|
+ * truncated name in this case).
|
|
|
+ */
|
|
|
+static long (*bpf_sysctl_get_name)(struct bpf_sysctl *ctx, char *buf, unsigned long buf_len, __u64 flags) = (void *) 101;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_sysctl_get_current_value
|
|
|
+ *
|
|
|
+ * Get current value of sysctl as it is presented in /proc/sys
|
|
|
+ * (incl. newline, etc), and copy it as a string into provided
|
|
|
+ * by program buffer *buf* of size *buf_len*.
|
|
|
+ *
|
|
|
+ * The whole value is copied, no matter what file position user
|
|
|
+ * space issued e.g. sys_read at.
|
|
|
+ *
|
|
|
+ * The buffer is always NUL terminated, unless it's zero-sized.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * Number of character copied (not including the trailing NUL).
|
|
|
+ *
|
|
|
+ * **-E2BIG** if the buffer wasn't big enough (*buf* will contain
|
|
|
+ * truncated name in this case).
|
|
|
+ *
|
|
|
+ * **-EINVAL** if current value was unavailable, e.g. because
|
|
|
+ * sysctl is uninitialized and read returns -EIO for it.
|
|
|
+ */
|
|
|
+static long (*bpf_sysctl_get_current_value)(struct bpf_sysctl *ctx, char *buf, unsigned long buf_len) = (void *) 102;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_sysctl_get_new_value
|
|
|
+ *
|
|
|
+ * Get new value being written by user space to sysctl (before
|
|
|
+ * the actual write happens) and copy it as a string into
|
|
|
+ * provided by program buffer *buf* of size *buf_len*.
|
|
|
+ *
|
|
|
+ * User space may write new value at file position > 0.
|
|
|
+ *
|
|
|
+ * The buffer is always NUL terminated, unless it's zero-sized.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * Number of character copied (not including the trailing NUL).
|
|
|
+ *
|
|
|
+ * **-E2BIG** if the buffer wasn't big enough (*buf* will contain
|
|
|
+ * truncated name in this case).
|
|
|
+ *
|
|
|
+ * **-EINVAL** if sysctl is being read.
|
|
|
+ */
|
|
|
+static long (*bpf_sysctl_get_new_value)(struct bpf_sysctl *ctx, char *buf, unsigned long buf_len) = (void *) 103;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_sysctl_set_new_value
|
|
|
+ *
|
|
|
+ * Override new value being written by user space to sysctl with
|
|
|
+ * value provided by program in buffer *buf* of size *buf_len*.
|
|
|
+ *
|
|
|
+ * *buf* should contain a string in same form as provided by user
|
|
|
+ * space on sysctl write.
|
|
|
+ *
|
|
|
+ * User space may write new value at file position > 0. To override
|
|
|
+ * the whole sysctl value file position should be set to zero.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success.
|
|
|
+ *
|
|
|
+ * **-E2BIG** if the *buf_len* is too big.
|
|
|
+ *
|
|
|
+ * **-EINVAL** if sysctl is being read.
|
|
|
+ */
|
|
|
+static long (*bpf_sysctl_set_new_value)(struct bpf_sysctl *ctx, const char *buf, unsigned long buf_len) = (void *) 104;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_strtol
|
|
|
+ *
|
|
|
+ * Convert the initial part of the string from buffer *buf* of
|
|
|
+ * size *buf_len* to a long integer according to the given base
|
|
|
+ * and save the result in *res*.
|
|
|
+ *
|
|
|
+ * The string may begin with an arbitrary amount of white space
|
|
|
+ * (as determined by **isspace**\ (3)) followed by a single
|
|
|
+ * optional '**-**' sign.
|
|
|
+ *
|
|
|
+ * Five least significant bits of *flags* encode base, other bits
|
|
|
+ * are currently unused.
|
|
|
+ *
|
|
|
+ * Base must be either 8, 10, 16 or 0 to detect it automatically
|
|
|
+ * similar to user space **strtol**\ (3).
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * Number of characters consumed on success. Must be positive but
|
|
|
+ * no more than *buf_len*.
|
|
|
+ *
|
|
|
+ * **-EINVAL** if no valid digits were found or unsupported base
|
|
|
+ * was provided.
|
|
|
+ *
|
|
|
+ * **-ERANGE** if resulting value was out of range.
|
|
|
+ */
|
|
|
+static long (*bpf_strtol)(const char *buf, unsigned long buf_len, __u64 flags, long *res) = (void *) 105;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_strtoul
|
|
|
+ *
|
|
|
+ * Convert the initial part of the string from buffer *buf* of
|
|
|
+ * size *buf_len* to an unsigned long integer according to the
|
|
|
+ * given base and save the result in *res*.
|
|
|
+ *
|
|
|
+ * The string may begin with an arbitrary amount of white space
|
|
|
+ * (as determined by **isspace**\ (3)).
|
|
|
+ *
|
|
|
+ * Five least significant bits of *flags* encode base, other bits
|
|
|
+ * are currently unused.
|
|
|
+ *
|
|
|
+ * Base must be either 8, 10, 16 or 0 to detect it automatically
|
|
|
+ * similar to user space **strtoul**\ (3).
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * Number of characters consumed on success. Must be positive but
|
|
|
+ * no more than *buf_len*.
|
|
|
+ *
|
|
|
+ * **-EINVAL** if no valid digits were found or unsupported base
|
|
|
+ * was provided.
|
|
|
+ *
|
|
|
+ * **-ERANGE** if resulting value was out of range.
|
|
|
+ */
|
|
|
+static long (*bpf_strtoul)(const char *buf, unsigned long buf_len, __u64 flags, unsigned long *res) = (void *) 106;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_sk_storage_get
|
|
|
+ *
|
|
|
+ * Get a bpf-local-storage from a *sk*.
|
|
|
+ *
|
|
|
+ * Logically, it could be thought of getting the value from
|
|
|
+ * a *map* with *sk* as the **key**. From this
|
|
|
+ * perspective, the usage is not much different from
|
|
|
+ * **bpf_map_lookup_elem**\ (*map*, **&**\ *sk*) except this
|
|
|
+ * helper enforces the key must be a full socket and the map must
|
|
|
+ * be a **BPF_MAP_TYPE_SK_STORAGE** also.
|
|
|
+ *
|
|
|
+ * Underneath, the value is stored locally at *sk* instead of
|
|
|
+ * the *map*. The *map* is used as the bpf-local-storage
|
|
|
+ * "type". The bpf-local-storage "type" (i.e. the *map*) is
|
|
|
+ * searched against all bpf-local-storages residing at *sk*.
|
|
|
+ *
|
|
|
+ * An optional *flags* (**BPF_SK_STORAGE_GET_F_CREATE**) can be
|
|
|
+ * used such that a new bpf-local-storage will be
|
|
|
+ * created if one does not exist. *value* can be used
|
|
|
+ * together with **BPF_SK_STORAGE_GET_F_CREATE** to specify
|
|
|
+ * the initial value of a bpf-local-storage. If *value* is
|
|
|
+ * **NULL**, the new bpf-local-storage will be zero initialized.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * A bpf-local-storage pointer is returned on success.
|
|
|
+ *
|
|
|
+ * **NULL** if not found or there was an error in adding
|
|
|
+ * a new bpf-local-storage.
|
|
|
+ */
|
|
|
+static void *(*bpf_sk_storage_get)(void *map, struct bpf_sock *sk, void *value, __u64 flags) = (void *) 107;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_sk_storage_delete
|
|
|
+ *
|
|
|
+ * Delete a bpf-local-storage from a *sk*.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success.
|
|
|
+ *
|
|
|
+ * **-ENOENT** if the bpf-local-storage cannot be found.
|
|
|
+ */
|
|
|
+static long (*bpf_sk_storage_delete)(void *map, struct bpf_sock *sk) = (void *) 108;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_send_signal
|
|
|
+ *
|
|
|
+ * Send signal *sig* to the process of the current task.
|
|
|
+ * The signal may be delivered to any of this process's threads.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success or successfully queued.
|
|
|
+ *
|
|
|
+ * **-EBUSY** if work queue under nmi is full.
|
|
|
+ *
|
|
|
+ * **-EINVAL** if *sig* is invalid.
|
|
|
+ *
|
|
|
+ * **-EPERM** if no permission to send the *sig*.
|
|
|
+ *
|
|
|
+ * **-EAGAIN** if bpf program can try again.
|
|
|
+ */
|
|
|
+static long (*bpf_send_signal)(__u32 sig) = (void *) 109;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_tcp_gen_syncookie
|
|
|
+ *
|
|
|
+ * Try to issue a SYN cookie for the packet with corresponding
|
|
|
+ * IP/TCP headers, *iph* and *th*, on the listening socket in *sk*.
|
|
|
+ *
|
|
|
+ * *iph* points to the start of the IPv4 or IPv6 header, while
|
|
|
+ * *iph_len* contains **sizeof**\ (**struct iphdr**) or
|
|
|
+ * **sizeof**\ (**struct ip6hdr**).
|
|
|
+ *
|
|
|
+ * *th* points to the start of the TCP header, while *th_len*
|
|
|
+ * contains the length of the TCP header.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * On success, lower 32 bits hold the generated SYN cookie in
|
|
|
+ * followed by 16 bits which hold the MSS value for that cookie,
|
|
|
+ * and the top 16 bits are unused.
|
|
|
+ *
|
|
|
+ * On failure, the returned value is one of the following:
|
|
|
+ *
|
|
|
+ * **-EINVAL** SYN cookie cannot be issued due to error
|
|
|
+ *
|
|
|
+ * **-ENOENT** SYN cookie should not be issued (no SYN flood)
|
|
|
+ *
|
|
|
+ * **-EOPNOTSUPP** kernel configuration does not enable SYN cookies
|
|
|
+ *
|
|
|
+ * **-EPROTONOSUPPORT** IP packet version is not 4 or 6
|
|
|
+ */
|
|
|
+static __s64 (*bpf_tcp_gen_syncookie)(struct bpf_sock *sk, void *iph, __u32 iph_len, struct tcphdr *th, __u32 th_len) = (void *) 110;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_skb_output
|
|
|
+ *
|
|
|
+ * Write raw *data* blob into a special BPF perf event held by
|
|
|
+ * *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf
|
|
|
+ * event must have the following attributes: **PERF_SAMPLE_RAW**
|
|
|
+ * as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and
|
|
|
+ * **PERF_COUNT_SW_BPF_OUTPUT** as **config**.
|
|
|
+ *
|
|
|
+ * The *flags* are used to indicate the index in *map* for which
|
|
|
+ * the value must be put, masked with **BPF_F_INDEX_MASK**.
|
|
|
+ * Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU**
|
|
|
+ * to indicate that the index of the current CPU core should be
|
|
|
+ * used.
|
|
|
+ *
|
|
|
+ * The value to write, of *size*, is passed through eBPF stack and
|
|
|
+ * pointed by *data*.
|
|
|
+ *
|
|
|
+ * *ctx* is a pointer to in-kernel struct sk_buff.
|
|
|
+ *
|
|
|
+ * This helper is similar to **bpf_perf_event_output**\ () but
|
|
|
+ * restricted to raw_tracepoint bpf programs.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_skb_output)(void *ctx, void *map, __u64 flags, void *data, __u64 size) = (void *) 111;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_probe_read_user
|
|
|
+ *
|
|
|
+ * Safely attempt to read *size* bytes from user space address
|
|
|
+ * *unsafe_ptr* and store the data in *dst*.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_probe_read_user)(void *dst, __u32 size, const void *unsafe_ptr) = (void *) 112;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_probe_read_kernel
|
|
|
+ *
|
|
|
+ * Safely attempt to read *size* bytes from kernel space address
|
|
|
+ * *unsafe_ptr* and store the data in *dst*.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_probe_read_kernel)(void *dst, __u32 size, const void *unsafe_ptr) = (void *) 113;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_probe_read_user_str
|
|
|
+ *
|
|
|
+ * Copy a NUL terminated string from an unsafe user address
|
|
|
+ * *unsafe_ptr* to *dst*. The *size* should include the
|
|
|
+ * terminating NUL byte. In case the string length is smaller than
|
|
|
+ * *size*, the target is not padded with further NUL bytes. If the
|
|
|
+ * string length is larger than *size*, just *size*-1 bytes are
|
|
|
+ * copied and the last byte is set to NUL.
|
|
|
+ *
|
|
|
+ * On success, the length of the copied string is returned. This
|
|
|
+ * makes this helper useful in tracing programs for reading
|
|
|
+ * strings, and more importantly to get its length at runtime. See
|
|
|
+ * the following snippet:
|
|
|
+ *
|
|
|
+ * ::
|
|
|
+ *
|
|
|
+ * SEC("kprobe/sys_open")
|
|
|
+ * void bpf_sys_open(struct pt_regs *ctx)
|
|
|
+ * {
|
|
|
+ * char buf[PATHLEN]; // PATHLEN is defined to 256
|
|
|
+ * int res = bpf_probe_read_user_str(buf, sizeof(buf),
|
|
|
+ * ctx->di);
|
|
|
+ *
|
|
|
+ * // Consume buf, for example push it to
|
|
|
+ * // userspace via bpf_perf_event_output(); we
|
|
|
+ * // can use res (the string length) as event
|
|
|
+ * // size, after checking its boundaries.
|
|
|
+ * }
|
|
|
+ *
|
|
|
+ * In comparison, using **bpf_probe_read_user**\ () helper here
|
|
|
+ * instead to read the string would require to estimate the length
|
|
|
+ * at compile time, and would often result in copying more memory
|
|
|
+ * than necessary.
|
|
|
+ *
|
|
|
+ * Another useful use case is when parsing individual process
|
|
|
+ * arguments or individual environment variables navigating
|
|
|
+ * *current*\ **->mm->arg_start** and *current*\
|
|
|
+ * **->mm->env_start**: using this helper and the return value,
|
|
|
+ * one can quickly iterate at the right offset of the memory area.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * On success, the strictly positive length of the string,
|
|
|
+ * including the trailing NUL character. On error, a negative
|
|
|
+ * value.
|
|
|
+ */
|
|
|
+static long (*bpf_probe_read_user_str)(void *dst, __u32 size, const void *unsafe_ptr) = (void *) 114;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_probe_read_kernel_str
|
|
|
+ *
|
|
|
+ * Copy a NUL terminated string from an unsafe kernel address *unsafe_ptr*
|
|
|
+ * to *dst*. Same semantics as with **bpf_probe_read_user_str**\ () apply.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * On success, the strictly positive length of the string, including
|
|
|
+ * the trailing NUL character. On error, a negative value.
|
|
|
+ */
|
|
|
+static long (*bpf_probe_read_kernel_str)(void *dst, __u32 size, const void *unsafe_ptr) = (void *) 115;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_tcp_send_ack
|
|
|
+ *
|
|
|
+ * Send out a tcp-ack. *tp* is the in-kernel struct **tcp_sock**.
|
|
|
+ * *rcv_nxt* is the ack_seq to be sent out.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_tcp_send_ack)(void *tp, __u32 rcv_nxt) = (void *) 116;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_send_signal_thread
|
|
|
+ *
|
|
|
+ * Send signal *sig* to the thread corresponding to the current task.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success or successfully queued.
|
|
|
+ *
|
|
|
+ * **-EBUSY** if work queue under nmi is full.
|
|
|
+ *
|
|
|
+ * **-EINVAL** if *sig* is invalid.
|
|
|
+ *
|
|
|
+ * **-EPERM** if no permission to send the *sig*.
|
|
|
+ *
|
|
|
+ * **-EAGAIN** if bpf program can try again.
|
|
|
+ */
|
|
|
+static long (*bpf_send_signal_thread)(__u32 sig) = (void *) 117;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_jiffies64
|
|
|
+ *
|
|
|
+ * Obtain the 64bit jiffies
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * The 64 bit jiffies
|
|
|
+ */
|
|
|
+static __u64 (*bpf_jiffies64)(void) = (void *) 118;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_read_branch_records
|
|
|
+ *
|
|
|
+ * For an eBPF program attached to a perf event, retrieve the
|
|
|
+ * branch records (**struct perf_branch_entry**) associated to *ctx*
|
|
|
+ * and store it in the buffer pointed by *buf* up to size
|
|
|
+ * *size* bytes.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * On success, number of bytes written to *buf*. On error, a
|
|
|
+ * negative value.
|
|
|
+ *
|
|
|
+ * The *flags* can be set to **BPF_F_GET_BRANCH_RECORDS_SIZE** to
|
|
|
+ * instead return the number of bytes required to store all the
|
|
|
+ * branch entries. If this flag is set, *buf* may be NULL.
|
|
|
+ *
|
|
|
+ * **-EINVAL** if arguments invalid or **size** not a multiple
|
|
|
+ * of **sizeof**\ (**struct perf_branch_entry**\ ).
|
|
|
+ *
|
|
|
+ * **-ENOENT** if architecture does not support branch records.
|
|
|
+ */
|
|
|
+static long (*bpf_read_branch_records)(struct bpf_perf_event_data *ctx, void *buf, __u32 size, __u64 flags) = (void *) 119;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_get_ns_current_pid_tgid
|
|
|
+ *
|
|
|
+ * Returns 0 on success, values for *pid* and *tgid* as seen from the current
|
|
|
+ * *namespace* will be returned in *nsdata*.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or one of the following in case of failure:
|
|
|
+ *
|
|
|
+ * **-EINVAL** if dev and inum supplied don't match dev_t and inode number
|
|
|
+ * with nsfs of current task, or if dev conversion to dev_t lost high bits.
|
|
|
+ *
|
|
|
+ * **-ENOENT** if pidns does not exists for the current task.
|
|
|
+ */
|
|
|
+static long (*bpf_get_ns_current_pid_tgid)(__u64 dev, __u64 ino, struct bpf_pidns_info *nsdata, __u32 size) = (void *) 120;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_xdp_output
|
|
|
+ *
|
|
|
+ * Write raw *data* blob into a special BPF perf event held by
|
|
|
+ * *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf
|
|
|
+ * event must have the following attributes: **PERF_SAMPLE_RAW**
|
|
|
+ * as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and
|
|
|
+ * **PERF_COUNT_SW_BPF_OUTPUT** as **config**.
|
|
|
+ *
|
|
|
+ * The *flags* are used to indicate the index in *map* for which
|
|
|
+ * the value must be put, masked with **BPF_F_INDEX_MASK**.
|
|
|
+ * Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU**
|
|
|
+ * to indicate that the index of the current CPU core should be
|
|
|
+ * used.
|
|
|
+ *
|
|
|
+ * The value to write, of *size*, is passed through eBPF stack and
|
|
|
+ * pointed by *data*.
|
|
|
+ *
|
|
|
+ * *ctx* is a pointer to in-kernel struct xdp_buff.
|
|
|
+ *
|
|
|
+ * This helper is similar to **bpf_perf_eventoutput**\ () but
|
|
|
+ * restricted to raw_tracepoint bpf programs.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_xdp_output)(void *ctx, void *map, __u64 flags, void *data, __u64 size) = (void *) 121;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_get_netns_cookie
|
|
|
+ *
|
|
|
+ * Retrieve the cookie (generated by the kernel) of the network
|
|
|
+ * namespace the input *ctx* is associated with. The network
|
|
|
+ * namespace cookie remains stable for its lifetime and provides
|
|
|
+ * a global identifier that can be assumed unique. If *ctx* is
|
|
|
+ * NULL, then the helper returns the cookie for the initial
|
|
|
+ * network namespace. The cookie itself is very similar to that
|
|
|
+ * of **bpf_get_socket_cookie**\ () helper, but for network
|
|
|
+ * namespaces instead of sockets.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * A 8-byte long opaque number.
|
|
|
+ */
|
|
|
+static __u64 (*bpf_get_netns_cookie)(void *ctx) = (void *) 122;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_get_current_ancestor_cgroup_id
|
|
|
+ *
|
|
|
+ * Return id of cgroup v2 that is ancestor of the cgroup associated
|
|
|
+ * with the current task at the *ancestor_level*. The root cgroup
|
|
|
+ * is at *ancestor_level* zero and each step down the hierarchy
|
|
|
+ * increments the level. If *ancestor_level* == level of cgroup
|
|
|
+ * associated with the current task, then return value will be the
|
|
|
+ * same as that of **bpf_get_current_cgroup_id**\ ().
|
|
|
+ *
|
|
|
+ * The helper is useful to implement policies based on cgroups
|
|
|
+ * that are upper in hierarchy than immediate cgroup associated
|
|
|
+ * with the current task.
|
|
|
+ *
|
|
|
+ * The format of returned id and helper limitations are same as in
|
|
|
+ * **bpf_get_current_cgroup_id**\ ().
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * The id is returned or 0 in case the id could not be retrieved.
|
|
|
+ */
|
|
|
+static __u64 (*bpf_get_current_ancestor_cgroup_id)(int ancestor_level) = (void *) 123;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_sk_assign
|
|
|
+ *
|
|
|
+ * Helper is overloaded depending on BPF program type. This
|
|
|
+ * description applies to **BPF_PROG_TYPE_SCHED_CLS** and
|
|
|
+ * **BPF_PROG_TYPE_SCHED_ACT** programs.
|
|
|
+ *
|
|
|
+ * Assign the *sk* to the *skb*. When combined with appropriate
|
|
|
+ * routing configuration to receive the packet towards the socket,
|
|
|
+ * will cause *skb* to be delivered to the specified socket.
|
|
|
+ * Subsequent redirection of *skb* via **bpf_redirect**\ (),
|
|
|
+ * **bpf_clone_redirect**\ () or other methods outside of BPF may
|
|
|
+ * interfere with successful delivery to the socket.
|
|
|
+ *
|
|
|
+ * This operation is only valid from TC ingress path.
|
|
|
+ *
|
|
|
+ * The *flags* argument must be zero.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure:
|
|
|
+ *
|
|
|
+ * **-EINVAL** if specified *flags* are not supported.
|
|
|
+ *
|
|
|
+ * **-ENOENT** if the socket is unavailable for assignment.
|
|
|
+ *
|
|
|
+ * **-ENETUNREACH** if the socket is unreachable (wrong netns).
|
|
|
+ *
|
|
|
+ * **-EOPNOTSUPP** if the operation is not supported, for example
|
|
|
+ * a call from outside of TC ingress.
|
|
|
+ *
|
|
|
+ * **-ESOCKTNOSUPPORT** if the socket type is not supported
|
|
|
+ * (reuseport).
|
|
|
+ */
|
|
|
+static long (*bpf_sk_assign)(void *ctx, struct bpf_sock *sk, __u64 flags) = (void *) 124;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_ktime_get_boot_ns
|
|
|
+ *
|
|
|
+ * Return the time elapsed since system boot, in nanoseconds.
|
|
|
+ * Does include the time the system was suspended.
|
|
|
+ * See: **clock_gettime**\ (**CLOCK_BOOTTIME**)
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * Current *ktime*.
|
|
|
+ */
|
|
|
+static __u64 (*bpf_ktime_get_boot_ns)(void) = (void *) 125;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_seq_printf
|
|
|
+ *
|
|
|
+ * **bpf_seq_printf**\ () uses seq_file **seq_printf**\ () to print
|
|
|
+ * out the format string.
|
|
|
+ * The *m* represents the seq_file. The *fmt* and *fmt_size* are for
|
|
|
+ * the format string itself. The *data* and *data_len* are format string
|
|
|
+ * arguments. The *data* are a **u64** array and corresponding format string
|
|
|
+ * values are stored in the array. For strings and pointers where pointees
|
|
|
+ * are accessed, only the pointer values are stored in the *data* array.
|
|
|
+ * The *data_len* is the size of *data* in bytes.
|
|
|
+ *
|
|
|
+ * Formats **%s**, **%p{i,I}{4,6}** requires to read kernel memory.
|
|
|
+ * Reading kernel memory may fail due to either invalid address or
|
|
|
+ * valid address but requiring a major memory fault. If reading kernel memory
|
|
|
+ * fails, the string for **%s** will be an empty string, and the ip
|
|
|
+ * address for **%p{i,I}{4,6}** will be 0. Not returning error to
|
|
|
+ * bpf program is consistent with what **bpf_trace_printk**\ () does for now.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure:
|
|
|
+ *
|
|
|
+ * **-EBUSY** if per-CPU memory copy buffer is busy, can try again
|
|
|
+ * by returning 1 from bpf program.
|
|
|
+ *
|
|
|
+ * **-EINVAL** if arguments are invalid, or if *fmt* is invalid/unsupported.
|
|
|
+ *
|
|
|
+ * **-E2BIG** if *fmt* contains too many format specifiers.
|
|
|
+ *
|
|
|
+ * **-EOVERFLOW** if an overflow happened: The same object will be tried again.
|
|
|
+ */
|
|
|
+static long (*bpf_seq_printf)(struct seq_file *m, const char *fmt, __u32 fmt_size, const void *data, __u32 data_len) = (void *) 126;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_seq_write
|
|
|
+ *
|
|
|
+ * **bpf_seq_write**\ () uses seq_file **seq_write**\ () to write the data.
|
|
|
+ * The *m* represents the seq_file. The *data* and *len* represent the
|
|
|
+ * data to write in bytes.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure:
|
|
|
+ *
|
|
|
+ * **-EOVERFLOW** if an overflow happened: The same object will be tried again.
|
|
|
+ */
|
|
|
+static long (*bpf_seq_write)(struct seq_file *m, const void *data, __u32 len) = (void *) 127;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_sk_cgroup_id
|
|
|
+ *
|
|
|
+ * Return the cgroup v2 id of the socket *sk*.
|
|
|
+ *
|
|
|
+ * *sk* must be a non-**NULL** pointer to a full socket, e.g. one
|
|
|
+ * returned from **bpf_sk_lookup_xxx**\ (),
|
|
|
+ * **bpf_sk_fullsock**\ (), etc. The format of returned id is
|
|
|
+ * same as in **bpf_skb_cgroup_id**\ ().
|
|
|
+ *
|
|
|
+ * This helper is available only if the kernel was compiled with
|
|
|
+ * the **CONFIG_SOCK_CGROUP_DATA** configuration option.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * The id is returned or 0 in case the id could not be retrieved.
|
|
|
+ */
|
|
|
+static __u64 (*bpf_sk_cgroup_id)(struct bpf_sock *sk) = (void *) 128;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_sk_ancestor_cgroup_id
|
|
|
+ *
|
|
|
+ * Return id of cgroup v2 that is ancestor of cgroup associated
|
|
|
+ * with the *sk* at the *ancestor_level*. The root cgroup is at
|
|
|
+ * *ancestor_level* zero and each step down the hierarchy
|
|
|
+ * increments the level. If *ancestor_level* == level of cgroup
|
|
|
+ * associated with *sk*, then return value will be same as that
|
|
|
+ * of **bpf_sk_cgroup_id**\ ().
|
|
|
+ *
|
|
|
+ * The helper is useful to implement policies based on cgroups
|
|
|
+ * that are upper in hierarchy than immediate cgroup associated
|
|
|
+ * with *sk*.
|
|
|
+ *
|
|
|
+ * The format of returned id and helper limitations are same as in
|
|
|
+ * **bpf_sk_cgroup_id**\ ().
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * The id is returned or 0 in case the id could not be retrieved.
|
|
|
+ */
|
|
|
+static __u64 (*bpf_sk_ancestor_cgroup_id)(struct bpf_sock *sk, int ancestor_level) = (void *) 129;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_ringbuf_output
|
|
|
+ *
|
|
|
+ * Copy *size* bytes from *data* into a ring buffer *ringbuf*.
|
|
|
+ * If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification
|
|
|
+ * of new data availability is sent.
|
|
|
+ * If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification
|
|
|
+ * of new data availability is sent unconditionally.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_ringbuf_output)(void *ringbuf, void *data, __u64 size, __u64 flags) = (void *) 130;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_ringbuf_reserve
|
|
|
+ *
|
|
|
+ * Reserve *size* bytes of payload in a ring buffer *ringbuf*.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * Valid pointer with *size* bytes of memory available; NULL,
|
|
|
+ * otherwise.
|
|
|
+ */
|
|
|
+static void *(*bpf_ringbuf_reserve)(void *ringbuf, __u64 size, __u64 flags) = (void *) 131;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_ringbuf_submit
|
|
|
+ *
|
|
|
+ * Submit reserved ring buffer sample, pointed to by *data*.
|
|
|
+ * If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification
|
|
|
+ * of new data availability is sent.
|
|
|
+ * If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification
|
|
|
+ * of new data availability is sent unconditionally.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * Nothing. Always succeeds.
|
|
|
+ */
|
|
|
+static void (*bpf_ringbuf_submit)(void *data, __u64 flags) = (void *) 132;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_ringbuf_discard
|
|
|
+ *
|
|
|
+ * Discard reserved ring buffer sample, pointed to by *data*.
|
|
|
+ * If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification
|
|
|
+ * of new data availability is sent.
|
|
|
+ * If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification
|
|
|
+ * of new data availability is sent unconditionally.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * Nothing. Always succeeds.
|
|
|
+ */
|
|
|
+static void (*bpf_ringbuf_discard)(void *data, __u64 flags) = (void *) 133;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_ringbuf_query
|
|
|
+ *
|
|
|
+ * Query various characteristics of provided ring buffer. What
|
|
|
+ * exactly is queries is determined by *flags*:
|
|
|
+ *
|
|
|
+ * * **BPF_RB_AVAIL_DATA**: Amount of data not yet consumed.
|
|
|
+ * * **BPF_RB_RING_SIZE**: The size of ring buffer.
|
|
|
+ * * **BPF_RB_CONS_POS**: Consumer position (can wrap around).
|
|
|
+ * * **BPF_RB_PROD_POS**: Producer(s) position (can wrap around).
|
|
|
+ *
|
|
|
+ * Data returned is just a momentary snapshot of actual values
|
|
|
+ * and could be inaccurate, so this facility should be used to
|
|
|
+ * power heuristics and for reporting, not to make 100% correct
|
|
|
+ * calculation.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * Requested value, or 0, if *flags* are not recognized.
|
|
|
+ */
|
|
|
+static __u64 (*bpf_ringbuf_query)(void *ringbuf, __u64 flags) = (void *) 134;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_csum_level
|
|
|
+ *
|
|
|
+ * Change the skbs checksum level by one layer up or down, or
|
|
|
+ * reset it entirely to none in order to have the stack perform
|
|
|
+ * checksum validation. The level is applicable to the following
|
|
|
+ * protocols: TCP, UDP, GRE, SCTP, FCOE. For example, a decap of
|
|
|
+ * | ETH | IP | UDP | GUE | IP | TCP | into | ETH | IP | TCP |
|
|
|
+ * through **bpf_skb_adjust_room**\ () helper with passing in
|
|
|
+ * **BPF_F_ADJ_ROOM_NO_CSUM_RESET** flag would require one call
|
|
|
+ * to **bpf_csum_level**\ () with **BPF_CSUM_LEVEL_DEC** since
|
|
|
+ * the UDP header is removed. Similarly, an encap of the latter
|
|
|
+ * into the former could be accompanied by a helper call to
|
|
|
+ * **bpf_csum_level**\ () with **BPF_CSUM_LEVEL_INC** if the
|
|
|
+ * skb is still intended to be processed in higher layers of the
|
|
|
+ * stack instead of just egressing at tc.
|
|
|
+ *
|
|
|
+ * There are three supported level settings at this time:
|
|
|
+ *
|
|
|
+ * * **BPF_CSUM_LEVEL_INC**: Increases skb->csum_level for skbs
|
|
|
+ * with CHECKSUM_UNNECESSARY.
|
|
|
+ * * **BPF_CSUM_LEVEL_DEC**: Decreases skb->csum_level for skbs
|
|
|
+ * with CHECKSUM_UNNECESSARY.
|
|
|
+ * * **BPF_CSUM_LEVEL_RESET**: Resets skb->csum_level to 0 and
|
|
|
+ * sets CHECKSUM_NONE to force checksum validation by the stack.
|
|
|
+ * * **BPF_CSUM_LEVEL_QUERY**: No-op, returns the current
|
|
|
+ * skb->csum_level.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * 0 on success, or a negative error in case of failure. In the
|
|
|
+ * case of **BPF_CSUM_LEVEL_QUERY**, the current skb->csum_level
|
|
|
+ * is returned or the error code -EACCES in case the skb is not
|
|
|
+ * subject to CHECKSUM_UNNECESSARY.
|
|
|
+ */
|
|
|
+static long (*bpf_csum_level)(struct __sk_buff *skb, __u64 level) = (void *) 135;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_skc_to_tcp6_sock
|
|
|
+ *
|
|
|
+ * Dynamically cast a *sk* pointer to a *tcp6_sock* pointer.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * *sk* if casting is valid, or NULL otherwise.
|
|
|
+ */
|
|
|
+static struct tcp6_sock *(*bpf_skc_to_tcp6_sock)(void *sk) = (void *) 136;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_skc_to_tcp_sock
|
|
|
+ *
|
|
|
+ * Dynamically cast a *sk* pointer to a *tcp_sock* pointer.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * *sk* if casting is valid, or NULL otherwise.
|
|
|
+ */
|
|
|
+static struct tcp_sock *(*bpf_skc_to_tcp_sock)(void *sk) = (void *) 137;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_skc_to_tcp_timewait_sock
|
|
|
+ *
|
|
|
+ * Dynamically cast a *sk* pointer to a *tcp_timewait_sock* pointer.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * *sk* if casting is valid, or NULL otherwise.
|
|
|
+ */
|
|
|
+static struct tcp_timewait_sock *(*bpf_skc_to_tcp_timewait_sock)(void *sk) = (void *) 138;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_skc_to_tcp_request_sock
|
|
|
+ *
|
|
|
+ * Dynamically cast a *sk* pointer to a *tcp_request_sock* pointer.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * *sk* if casting is valid, or NULL otherwise.
|
|
|
+ */
|
|
|
+static struct tcp_request_sock *(*bpf_skc_to_tcp_request_sock)(void *sk) = (void *) 139;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_skc_to_udp6_sock
|
|
|
+ *
|
|
|
+ * Dynamically cast a *sk* pointer to a *udp6_sock* pointer.
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * *sk* if casting is valid, or NULL otherwise.
|
|
|
+ */
|
|
|
+static struct udp6_sock *(*bpf_skc_to_udp6_sock)(void *sk) = (void *) 140;
|
|
|
+
|
|
|
+/*
|
|
|
+ * bpf_get_task_stack
|
|
|
+ *
|
|
|
+ * Return a user or a kernel stack in bpf program provided buffer.
|
|
|
+ * To achieve this, the helper needs *task*, which is a valid
|
|
|
+ * pointer to struct task_struct. To store the stacktrace, the
|
|
|
+ * bpf program provides *buf* with a nonnegative *size*.
|
|
|
+ *
|
|
|
+ * The last argument, *flags*, holds the number of stack frames to
|
|
|
+ * skip (from 0 to 255), masked with
|
|
|
+ * **BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set
|
|
|
+ * the following flags:
|
|
|
+ *
|
|
|
+ * **BPF_F_USER_STACK**
|
|
|
+ * Collect a user space stack instead of a kernel stack.
|
|
|
+ * **BPF_F_USER_BUILD_ID**
|
|
|
+ * Collect buildid+offset instead of ips for user stack,
|
|
|
+ * only valid if **BPF_F_USER_STACK** is also specified.
|
|
|
+ *
|
|
|
+ * **bpf_get_task_stack**\ () can collect up to
|
|
|
+ * **PERF_MAX_STACK_DEPTH** both kernel and user frames, subject
|
|
|
+ * to sufficient large buffer size. Note that
|
|
|
+ * this limit can be controlled with the **sysctl** program, and
|
|
|
+ * that it should be manually increased in order to profile long
|
|
|
+ * user stacks (such as stacks for Java programs). To do so, use:
|
|
|
+ *
|
|
|
+ * ::
|
|
|
+ *
|
|
|
+ * # sysctl kernel.perf_event_max_stack=<new value>
|
|
|
+ *
|
|
|
+ * Returns
|
|
|
+ * A non-negative value equal to or less than *size* on success,
|
|
|
+ * or a negative error in case of failure.
|
|
|
+ */
|
|
|
+static long (*bpf_get_task_stack)(struct task_struct *task, void *buf, __u32 size, __u64 flags) = (void *) 141;
|
|
|
+
|
|
|
+
|
Akihiro Suda