Bind SCTP socket in a specific IP. Fixed #43, fixed #45

mmt-5greplay.conf

@@ -95,10 +95,11 @@ forward
 	default    = DROP #default action when packets are not selected/satisfied by any rule
 		# either FORWARD to forward the packets or DROP to drop the packets
 
-	#forward packets to a target using SCTP protocol: MMT will be a SCTP client, 
+	#forward packets to a target using SCTP protocol: 5Greplay will be a SCTP client, 
 	# - it connects to the given "sctp-host" at "sctp-port"
 	# - the SCTP packets' payload will be sent to the target using this SCTP connection
 	# target-protocols = { SCTP, UDP, HTTP2}
 	# target-hosts     = { "127.0.0.5", "127.0.0.7", "127.0.0.7" }
 	# target-ports     = { 38412, 2152, 8080 }
+	bind-ip    = "127.0.0.1" #bind sockets on a specific NIC which is given via its IP
 }

src/engine/configure.c

@@ -85,6 +85,7 @@ static inline cfg_t *_load_cfg_from_file(const char *filename) {
 			CFG_INT("snap-len",                 0, CFGF_NONE),
 			CFG_INT("nb-copies",                1, CFGF_NONE),
 			CFG_INT("promisc",                  0, CFGF_NONE),
+			CFG_STR("bind-ip",        "127.0.0.1", CFGF_NONE),
 			CFG_INT_CB("default",               ACTION_DROP, CFGF_NONE, _conf_parse_forward_default_action),
 			CFG_STR_LIST("target-protocols", "{}", CFGF_NONE),
 			CFG_STR_LIST("target-hosts",     "{}", CFGF_NONE),
@@ -265,6 +266,7 @@ static inline forward_packet_conf_t *_parse_forward_packet( cfg_t *cfg ){
 	ret->nb_copies = _cfg_getint( cfg, "nb-copies", 1, UINT32_MAX, 1 );
 	ret->promisc = _cfg_getint( cfg, "promisc", 0, 1, 1 );
 	ret->default_action = cfg_getint( cfg, "default" );
+	ret->bind_ip = _cfg_get_str(cfg, "bind-ip");
 
 	ret->target_size = cfg_size( cfg, "target-protocols");
 	ASSERT( ret->target_size == cfg_size( cfg, "target-hosts"), "Number of elements in target-protocols and target-hosts are different");

src/engine/configure.h

@@ -84,6 +84,7 @@ typedef struct forward_packet_conf_struct{
 	uint16_t promisc;
 	uint32_t nb_copies;
 	forward_action_t default_action;
+	char *bind_ip;
 
 	forward_packet_target_conf_t *targets;
 	uint16_t target_size;

src/engine/configure_override.h

@@ -141,6 +141,8 @@ DECLARE_CONF_ATT(
 	(CONF_ATT__FORWARD__SNAP_LEN,  "forward.snap-len",   &conf->forward->snap_len,   UINT16_T),
 	(CONF_ATT__FORWARD__NB_COPIES, "forward.nb-copies",  &conf->forward->nb_copies,  UINT32_T),
 	(CONF_ATT__FORWARD__DEFAULT,   "forward.default",    &conf->forward->default_action,  UINT32_T),
+	(CONF_ATT__FORWARD__BIND_IP,   "forward.bind-ip",    &conf->forward->bind_ip,  CHAR_STAR),
+
 	(CONF_ATT__FORWARD__TARGET_PROTOCOLS,   "forward.target-protocols", &conf->forward->targets,  LIST),
 	(CONF_ATT__FORWARD__TARGET_HOSTS,       "forward.target-hosts",     &conf->forward->targets,  LIST),
 	(CONF_ATT__FORWARD__TARGET_PORTS,       "forward.target-ports",     &conf->forward->targets,  LIST),

src/forward/proto/inject_proto.c

@@ -20,7 +20,7 @@ inject_proto_context_t* inject_proto_alloc( const config_t *config ){
 		target = & conf->targets[i];
 		switch( target->protocol ){
 		case FORWARD_PACKET_PROTO_SCTP:
-			context->sctp = inject_sctp_alloc(target, conf->nb_copies );
+			context->sctp = inject_sctp_alloc(target, conf->nb_copies, config->forward->bind_ip );
 			break;
 		case FORWARD_PACKET_PROTO_UDP:
 			context->udp = inject_udp_alloc(target, conf->nb_copies );

src/forward/proto/inject_sctp.c

@@ -42,6 +42,9 @@ struct inject_sctp_context_struct{
 	const char* host;
 	uint16_t port;
 
+	const char *bind_host;
+	uint16_t bind_port;
+
 	// the parameters to pass to sctp_sendmsg function to send sctp packets
 	// see more: https://linux.die.net/man/3/sctp_sendmsg
 	sctp_param_t sctp_param;
@@ -57,9 +60,29 @@ void _sctp_connect( inject_sctp_context_t *context ){
 			.sin_addr.s_addr = inet_addr( context->host ),
 	};
 
+	struct sockaddr_in bind_addr = {
+			.sin_family = AF_INET
+	};
+
 	conn_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_SCTP);
 	ASSERT( conn_fd >= 0, "Cannot create SCTP socket" );
 
+	//bind to a specific NIC
+	if( context->bind_host ){
+		bind_addr.sin_port = htons( context->bind_port );
+		bind_addr.sin_addr.s_addr = inet_addr( context->bind_host );
+		ret = sctp_bindx( conn_fd, (struct sockaddr *) &bind_addr,
+				1, //number of addresses
+				SCTP_BINDX_ADD_ADDR //to associate additional addresses
+				);
+		if( ret )
+			log_write( LOG_WARNING, "Cannot bind socket to %s:%d using SCTP: %s. Ignore it.",
+								context->bind_host, context->bind_port, strerror(errno) );
+		else
+			log_write( LOG_INFO, "Binded successfully socket to %s:%d using SCTP.",
+								context->bind_host, context->bind_port );
+	}
+
 	opt = 1;
 	ret = setsockopt(conn_fd, IPPROTO_SCTP, SCTP_NODELAY, &opt, sizeof(opt));
 	ASSERT( ret >= 0, "Cannot set SCTP_NODELAY to SCTP socket" );
@@ -77,14 +100,17 @@ void _sctp_connect( inject_sctp_context_t *context ){
 	context->shown_error = false;
 }
 
-inject_sctp_context_t* inject_sctp_alloc( const forward_packet_target_conf_t *conf, uint32_t nb_copies ){
+inject_sctp_context_t* inject_sctp_alloc( const forward_packet_target_conf_t *conf, uint32_t nb_copies, const char *bind_host ){
 
 
 	inject_sctp_context_t *context = mmt_mem_alloc_and_init_zero( sizeof( struct inject_sctp_context_struct ));
 	context->host      = conf->host;
 	context->port      = conf->port;
 	context->nb_copies = nb_copies;
 	context->total_sent_pkt = 0;
+	context->bind_host = bind_host;
+	context->bind_port = 0; //auto
+
 	//sctp parameters to send packets
 	inject_sctp_update_param( context,
 			60, //payload protocol id of NGAP protcol

src/forward/proto/inject_sctp.h

@@ -12,10 +12,9 @@
 
 typedef struct inject_sctp_context_struct inject_sctp_context_t;
 
-inject_sctp_context_t* inject_sctp_alloc( const forward_packet_target_conf_t *conf, uint32_t nb_copies );
+inject_sctp_context_t* inject_sctp_alloc( const forward_packet_target_conf_t *conf, uint32_t nb_copies, const char *bind_host );
 int inject_sctp_send_packet( inject_sctp_context_t *context, const uint8_t *packet_data, uint16_t packet_size );
 void inject_sctp_release( inject_sctp_context_t *context );
 
 void inject_sctp_update_param( inject_sctp_context_t *injector_context, uint32_t ppid, uint32_t flags, uint16_t stream_no, uint32_t timetolive, uint32_t ctx );
-
 #endif /* SRC_MODULES_SECURITY_FORWARD_PROTO_INJECT_SCTP_H_ */