socket: Add new OSMO_SOCK_F_NO_MCAST_ALL option
Using this option at socket creation, the caller can request disabling
the IP_MULTICAST_ALL socket option.
Change-Id: I5ab5de45c0b64ceb3636ea98245a23defa24ffd4
diff --git a/include/osmocom/core/socket.h b/include/osmocom/core/socket.h
index 695e1d7..ebfcab3 100644
--- a/include/osmocom/core/socket.h
+++ b/include/osmocom/core/socket.h
@@ -22,6 +22,8 @@
#define OSMO_SOCK_F_NONBLOCK (1 << 2)
/*! disable multiast loop (IP_MULTICAST_LOOP) */
#define OSMO_SOCK_F_NO_MCAST_LOOP (1 << 3)
+/*! disable receiving all multiast even for non-subscribed groups */
+#define OSMO_SOCK_F_NO_MCAST_ALL (1 << 4)
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 c7d081c..ca50b6f 100644
--- a/src/socket.c
+++ b/src/socket.c
@@ -132,6 +132,16 @@
}
}
+ if (flags & OSMO_SOCK_F_NO_MCAST_ALL) {
+ rc = osmo_sock_mcast_all_set(fd, false);
+ if (rc < 0) {
+ LOGP(DLGLOBAL, LOGL_ERROR, "unable to disable receive of all multicast: %s\n",
+ strerror(errno));
+ /* do not abort here, as this is just an
+ * optional additional optimization that only
+ * exists on Linux only */
+ }
+ }
return 0;
}