diff --git a/src/basic/missing_socket.h b/src/basic/missing_socket.h index a5fd457244..276be366c3 100644 --- a/src/basic/missing_socket.h +++ b/src/basic/missing_socket.h @@ -32,6 +32,10 @@ struct sockaddr_vm { #define SO_PEERGROUPS 59 #endif +#ifndef SO_BINDTOIFINDEX +#define SO_BINDTOIFINDEX 62 +#endif + #ifndef SOL_NETLINK #define SOL_NETLINK 270 #endif diff --git a/src/basic/socket-util.c b/src/basic/socket-util.c index 3c156fd659..3d929f5418 100644 --- a/src/basic/socket-util.c +++ b/src/basic/socket-util.c @@ -1354,3 +1354,39 @@ int sockaddr_un_set_path(struct sockaddr_un *ret, const char *path) { return (int) (offsetof(struct sockaddr_un, sun_path) + l + 1); /* include trailing NUL in size */ } } + +int socket_bind_to_ifname(int fd, const char *ifname) { + assert(fd >= 0); + + /* Call with NULL to drop binding */ + + if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen_ptr(ifname)) < 0) + return -errno; + + return 0; +} + +int socket_bind_to_ifindex(int fd, int ifindex) { + char ifname[IFNAMSIZ] = ""; + + assert(fd >= 0); + + if (ifindex <= 0) { + /* Drop binding */ + if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, NULL, 0) < 0) + return -errno; + + return 0; + } + + if (setsockopt(fd, SOL_SOCKET, SO_BINDTOIFINDEX, &ifindex, sizeof(ifindex)) >= 0) + return 0; + if (errno != ENOPROTOOPT) + return -errno; + + /* Fall back to SO_BINDTODEVICE on kernels < 5.0 which didn't have SO_BINDTOIFINDEX */ + if (!if_indextoname(ifindex, ifname)) + return -errno; + + return socket_bind_to_ifname(fd, ifname); +} diff --git a/src/basic/socket-util.h b/src/basic/socket-util.h index 574d2b73f5..6920fd99ba 100644 --- a/src/basic/socket-util.h +++ b/src/basic/socket-util.h @@ -198,3 +198,6 @@ static inline int setsockopt_int(int fd, int level, int optname, int value) { return 0; } + +int socket_bind_to_ifname(int fd, const char *ifname); +int socket_bind_to_ifindex(int fd, int ifindex);