From 73196e77fb28d71f5ab536d4e6265cfcbb169b3d Mon Sep 17 00:00:00 2001 From: Philipp Maier Date: Thu, 23 Aug 2018 20:11:50 +0200 Subject: socket: add flag to enforce SO_REUSEADDR on UDP sockets When IPPROTO_UDP is used then SO_REUSEADDR omitted since UDP is connection less we do not have to wait until lingering connections time out. There were also negative effects such as that two applicatications could use the same UDP port, normally one of the two applications would get an error, but with SO_REUSEADDR this is supressed. However, there are applications (UDP MULTICAST) where two applications must be able to use the same port. In the osmocom project those are osmo-bts-virtual, virtphy and gsmtap in general. Lets introduce a flag that the API user can supply in order to have SO_REUSEADDR applied. - Add new flag OSMO_SOCK_F_UDP_REUSEADDR Change-Id: I94aaf6d5224ab23bde5ea5c4a83569b6145ab32b Related: OS#3497 --- include/osmocom/core/socket.h | 2 ++ src/socket.c | 6 +++--- 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/include/osmocom/core/socket.h b/include/osmocom/core/socket.h index 20515b99..f23a2436 100644 --- a/include/osmocom/core/socket.h +++ b/include/osmocom/core/socket.h @@ -24,6 +24,8 @@ struct osmo_fd; #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) +/*! use SO_REUSEADDR on UDP ports (required for multicast) */ +#define OSMO_SOCK_F_UDP_REUSEADDR (1 << 5) 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 210dbf96..7e7f6d96 100644 --- a/src/socket.c +++ b/src/socket.c @@ -209,7 +209,7 @@ int osmo_sock_init2(uint16_t family, uint16_t type, uint8_t proto, if (sfd < 0) continue; - if (proto != IPPROTO_UDP) { + if (proto != IPPROTO_UDP || flags & OSMO_SOCK_F_UDP_REUSEADDR) { rc = setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)); if (rc < 0) { @@ -349,7 +349,7 @@ int osmo_sock_init(uint16_t family, uint16_t type, uint8_t proto, continue; } } else { - if (proto != IPPROTO_UDP) { + if (proto != IPPROTO_UDP || flags & OSMO_SOCK_F_UDP_REUSEADDR) { rc = setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)); if (rc < 0) { @@ -379,7 +379,7 @@ int osmo_sock_init(uint16_t family, uint16_t type, uint8_t proto, return -ENODEV; } - if (proto != IPPROTO_UDP) { + if (proto != IPPROTO_UDP || flags & OSMO_SOCK_F_UDP_REUSEADDR) { rc = setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)); if (rc < 0) { LOGP(DLGLOBAL, LOGL_ERROR, -- cgit v1.2.3