From bc43a62f4128348b52af50ae75c84ba772c17e29 Mon Sep 17 00:00:00 2001 From: Harald Welte Date: Thu, 13 Jul 2017 16:20:21 +0200 Subject: socket: Allow disabling multicast loop on socket creation This introduces a new flag OSMO_SOCK_F_NO_MCAST_LOOP, which can be used to disable the looping back of multicast packets transmitted throug this socket to other local sockets on the machine. As this looping-back is active by default, a single option to deviate from the default is deemed sufficient. Change-Id: I24a5b1ebc3f84d2d5d4734e54df50efaea26490b --- include/osmocom/core/socket.h | 2 ++ src/socket.c | 20 ++++++++++++++++---- 2 files changed, 18 insertions(+), 4 deletions(-) diff --git a/include/osmocom/core/socket.h b/include/osmocom/core/socket.h index 6db436ae..695e1d7e 100644 --- a/include/osmocom/core/socket.h +++ b/include/osmocom/core/socket.h @@ -20,6 +20,8 @@ struct osmo_fd; #define OSMO_SOCK_F_BIND (1 << 1) /*! switch socket to non-blocking mode */ #define OSMO_SOCK_F_NONBLOCK (1 << 2) +/*! disable multiast loop (IP_MULTICAST_LOOP) */ +#define OSMO_SOCK_F_NO_MCAST_LOOP (1 << 3) int osmo_sock_init(uint16_t family, uint16_t type, uint8_t proto, const char *host, uint16_t port, unsigned int flags); diff --git a/src/socket.c b/src/socket.c index d0e4c243..c7d081c3 100644 --- a/src/socket.c +++ b/src/socket.c @@ -106,7 +106,7 @@ static int socket_helper(const struct addrinfo *rp, unsigned int flags) static int osmo_sock_init_tail(int fd, uint16_t type, unsigned int flags) { - int rc = 0; + int rc; /* Make sure to call 'listen' on a bound, connection-oriented sock */ if ((flags & (OSMO_SOCK_F_BIND|OSMO_SOCK_F_CONNECT)) == OSMO_SOCK_F_BIND) { @@ -114,13 +114,25 @@ static int osmo_sock_init_tail(int fd, uint16_t type, unsigned int flags) case SOCK_STREAM: case SOCK_SEQPACKET: rc = listen(fd, 10); + if (rc < 0) { + LOGP(DLGLOBAL, LOGL_ERROR, "unable to listen on socket: %s\n", + strerror(errno)); + return rc; + } + break; } } - if (rc < 0) - LOGP(DLGLOBAL, LOGL_ERROR, "unable to listen on socket: %s\n", strerror(errno)); + if (flags & OSMO_SOCK_F_NO_MCAST_LOOP) { + rc = osmo_sock_mcast_loop_set(fd, false); + if (rc < 0) { + LOGP(DLGLOBAL, LOGL_ERROR, "unable to disable multicast loop: %s\n", + strerror(errno)); + return rc; + } + } - return rc; + return 0; } /*! Initialize a socket (including bind and/or connect) -- cgit v1.2.3