moby/profiles/seccomp/kernel_linux.go
Kir Kolyshkin 8a5c13155e all: use unix.ByteSliceToString for utsname fields
This also fixes the GetOperatingSystem function in
pkg/parsers/operatingsystem which mistakenly truncated utsname.Machine
to the index of \0 in utsname.Sysname.

Fixes: 7aeb3efcb4
Cc: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
2022-05-18 17:13:20 -07:00

58 lines
1.7 KiB
Go

package seccomp
import (
"fmt"
"sync"
"golang.org/x/sys/unix"
)
var (
currentKernelVersion *KernelVersion
kernelVersionError error
once sync.Once
)
// getKernelVersion gets the current kernel version.
func getKernelVersion() (*KernelVersion, error) {
once.Do(func() {
var uts unix.Utsname
if err := unix.Uname(&uts); err != nil {
return
}
// Remove the \x00 from the release for Atoi to parse correctly
currentKernelVersion, kernelVersionError = parseRelease(unix.ByteSliceToString(uts.Release[:]))
})
return currentKernelVersion, kernelVersionError
}
// parseRelease parses a string and creates a KernelVersion based on it.
func parseRelease(release string) (*KernelVersion, error) {
var version = KernelVersion{}
// We're only make sure we get the "kernel" and "major revision". Sometimes we have
// 3.12.25-gentoo, but sometimes we just have 3.12-1-amd64.
_, err := fmt.Sscanf(release, "%d.%d", &version.Kernel, &version.Major)
if err != nil {
return nil, fmt.Errorf("failed to parse kernel version %q: %w", release, err)
}
return &version, nil
}
// kernelGreaterEqualThan checks if the host's kernel version is greater than, or
// equal to the given kernel version v. Only "kernel version" and "major revision"
// can be specified (e.g., "3.12") and will be taken into account, which means
// that 3.12.25-gentoo and 3.12-1-amd64 are considered equal (kernel: 3, major: 12).
func kernelGreaterEqualThan(minVersion KernelVersion) (bool, error) {
kv, err := getKernelVersion()
if err != nil {
return false, err
}
if kv.Kernel > minVersion.Kernel {
return true, nil
}
if kv.Kernel == minVersion.Kernel && kv.Major >= minVersion.Major {
return true, nil
}
return false, nil
}