Everywhere: Port to String::copy_characters_to_buffer()

Author: https://github.com/bugaevc
Commit: https://github.com/SerenityOS/serenity/commit/852454746ea
Pull-request: https://github.com/SerenityOS/serenity/pull/3296
Reviewed-by: https://github.com/BenWiederhake
Reviewed-by: https://github.com/alimpfard

Libraries/LibC/time.cpp

@@ -304,10 +304,9 @@ size_t strftime(char* destination, size_t max_size, const char* format, const st
             return 0;
     }
 
-    if (builder.length() + 1 > max_size)
-        return 0;
-    strcpy(destination, builder.build().characters());
-    return builder.length();
+    auto str = builder.build();
+    bool fits = str.copy_characters_to_buffer(destination, max_size);
+    return fits ? str.length() : 0;
 }
 
 long timezone = 0;

Libraries/LibCore/Socket.cpp

@@ -112,13 +112,12 @@ bool Socket::connect(const SocketAddress& address)
     sockaddr_un saddr;
     saddr.sun_family = AF_LOCAL;
     auto dest_address = address.to_string();
-    if (dest_address.length() >= sizeof(saddr.sun_path)) {
+    bool fits = dest_address.copy_characters_to_buffer(saddr.sun_path, sizeof(saddr.sun_path));
+    if (!fits) {
         fprintf(stderr, "Core::Socket: Failed to connect() to %s: Path is too long!\n", dest_address.characters());
         errno = EINVAL;
         return false;
     }
-    strcpy(saddr.sun_path, address.to_string().characters());
-
     m_destination_address = address;
 
     return common_connect((const sockaddr*)&saddr, sizeof(saddr));

Libraries/LibCore/SocketAddress.h

@@ -87,10 +87,9 @@ public:
         ASSERT(type() == Type::Local);
         sockaddr_un address;
         address.sun_family = AF_LOCAL;
-        if (m_local_address.length() >= sizeof(address.sun_path)) {
+        bool fits = m_local_address.copy_characters_to_buffer(address.sun_path, sizeof(address.sun_path));
+        if (!fits)
             return {};
-        }
-        strcpy(address.sun_path, m_local_address.characters());
         return address;
     }
 

Libraries/LibCrypt/crypt.cpp

@@ -55,7 +55,11 @@ char* crypt_r(const char* key, const char* salt, struct crypt_data* data)
             size_t salt_len = min(strcspn(salt_value, "$"), crypt_salt_max);
             size_t header_len = salt_len + 3;
 
-            strncpy(data->result, salt, header_len);
+            bool fits = String(salt, header_len).copy_characters_to_buffer(data->result, sizeof(data->result));
+            if (!fits) {
+                errno = EINVAL;
+                return nullptr;
+            }
             data->result[header_len] = '$';
 
             Crypto::Hash::SHA256 sha;
@@ -65,7 +69,11 @@ char* crypt_r(const char* key, const char* salt, struct crypt_data* data)
             auto digest = sha.digest();
             auto string = encode_base64(ReadonlyBytes(digest.immutable_data(), digest.data_length()));
 
-            strncpy(data->result + header_len + 1, string.characters(), sha_string_length);
+            fits = string.copy_characters_to_buffer(data->result + header_len + 1, sizeof(data->result) - header_len - 1);
+            if (!fits) {
+                errno = EINVAL;
+                return nullptr;
+            }
 
             return data->result;
         }

Services/DHCPClient/DHCPv4Client.cpp

@@ -71,7 +71,12 @@ static void set_params(const InterfaceDescriptor& iface, const IPv4Address& ipv4
 
     struct ifreq ifr;
     memset(&ifr, 0, sizeof(ifr));
-    strlcpy(ifr.ifr_name, iface.m_ifname.characters(), IFNAMSIZ);
+
+    bool fits = iface.m_ifname.copy_characters_to_buffer(ifr.ifr_name, IFNAMSIZ);
+    if (!fits) {
+        dbg() << "Interface name doesn't fit into IFNAMSIZ!";
+        return;
+    }
 
     // set the IP address
     ifr.ifr_addr.sa_family = AF_INET;

Services/DHCPClient/DHCPv4Client.h

@@ -27,9 +27,9 @@
 #pragma once
 
 #include "DHCPv4.h"
-#include <AK/FlyString.h>
 #include <AK/HashMap.h>
 #include <AK/OwnPtr.h>
+#include <AK/String.h>
 #include <AK/Vector.h>
 #include <LibCore/UDPServer.h>
 #include <LibCore/UDPSocket.h>
@@ -39,7 +39,7 @@
 #include <sys/socket.h>
 
 struct InterfaceDescriptor {
-    FlyString m_ifname;
+    String m_ifname;
     MACAddress m_mac_address;
 };
 

Userland/ifconfig.cpp

@@ -116,7 +116,11 @@ int main(int argc, char** argv)
             struct ifreq ifr;
             memset(&ifr, 0, sizeof(ifr));
 
-            strlcpy(ifr.ifr_name, ifname.characters(), IFNAMSIZ);
+            bool fits = ifname.copy_characters_to_buffer(ifr.ifr_name, IFNAMSIZ);
+            if (!fits) {
+                fprintf(stderr, "Interface name '%s' is too long\n", ifname.characters());
+                return 1;
+            }
             ifr.ifr_addr.sa_family = AF_INET;
             ((sockaddr_in&)ifr.ifr_addr).sin_addr.s_addr = address.value().to_in_addr_t();
 
@@ -144,7 +148,11 @@ int main(int argc, char** argv)
             struct ifreq ifr;
             memset(&ifr, 0, sizeof(ifr));
 
-            strlcpy(ifr.ifr_name, ifname.characters(), IFNAMSIZ);
+            bool fits = ifname.copy_characters_to_buffer(ifr.ifr_name, IFNAMSIZ);
+            if (!fits) {
+                fprintf(stderr, "Interface name '%s' is too long\n", ifname.characters());
+                return 1;
+            }
             ifr.ifr_netmask.sa_family = AF_INET;
             ((sockaddr_in&)ifr.ifr_netmask).sin_addr.s_addr = address.value().to_in_addr_t();
 

Userland/ping.cpp

@@ -125,7 +125,10 @@ int main(int argc, char** argv)
         ping_packet.header.code = 0;
         ping_packet.header.un.echo.id = htons(pid);
         ping_packet.header.un.echo.sequence = htons(seq++);
-        strlcpy(ping_packet.msg, "Hello there!\n", sizeof(ping_packet.msg));
+
+        bool fits = String("Hello there!\n").copy_characters_to_buffer(ping_packet.msg, sizeof(ping_packet.msg));
+        // It's a constant string, we can be sure that it fits.
+        ASSERT(fits);
 
         ping_packet.header.checksum = internet_checksum(&ping_packet, sizeof(PingPacket));