Improve UDP support of ASYNC_IF

* peer_addr is now const
* new_link_udp_server() can bind to address or INADDR_ANY
* socket_udp_receive() happens without a loop
* socket_udp_send() happens without a loop
* sending in two packets (first size, then data) is only performed for TCP,
  SCTP, not for UDP anymore (it is unreliable, so we could miss something and
  will receive complete garbage)

openair2/UTIL/ASYNC_IF/link_manager.c

@@ -76,7 +76,7 @@ static void *link_manager_receiver_thread(void *_manager)
   LOG_D(MAC, "starting link manager receiver thread\n");
 
   while (manager->run) {
-    if (link_receive_packet(manager->socket_link, &data, &size, manager->type, manager->peer_addr, manager->port))
+    if (link_receive_packet(manager->socket_link, &data, &size, manager->type))
       goto error;
     /* todo: priority */
     if (message_put(manager->receive_queue, data, size, 0))

openair2/UTIL/ASYNC_IF/link_manager.h

@@ -46,7 +46,7 @@ typedef struct {
   message_queue_t *receive_queue;
   socket_link_t   *socket_link;
   uint16_t        type;
-  char            *peer_addr;
+  const char      *peer_addr;
   int             port;
   pthread_t       sender;
   pthread_t       receiver;

openair2/UTIL/ASYNC_IF/socket_link.c

@@ -163,8 +163,8 @@ error:
   return NULL;
 }
 
-socket_link_t *new_link_udp_server(int port){
-
+socket_link_t *new_link_udp_server(const char *bind_addr, int bind_port)
+{
   socket_link_t  *ret = NULL;
 
   struct sockaddr_in si_me;
@@ -188,11 +188,17 @@ socket_link_t *new_link_udp_server(int port){
   memset((char *) &si_me, 0, sizeof(si_me));
 
   si_me.sin_family = AF_INET;
-  si_me.sin_port = htons(port);
+  si_me.sin_port = htons(bind_port);
+  if (bind_addr) {
+    if (!inet_aton(bind_addr, &si_me.sin_addr))
+      goto error;
+  } else {
     si_me.sin_addr.s_addr = INADDR_ANY;
+  }
 
   //bind socket to port
   if( bind(socket_server , (struct sockaddr*)&si_me, sizeof(si_me) ) == -1) {
+    fprintf(stderr, "could not bind to address %s: %s\n", bind_addr, strerror(errno));
     goto error;
   }
   ret->socket_fd = socket_server;
@@ -356,12 +362,10 @@ error:
   return NULL;
 }
 
-static int socket_udp_send(int socket_fd, void *buf, int size, char *peer_addr, int port)
+static int socket_udp_send(int socket_fd, void *buf, int size, const char *peer_addr, int port)
 {
-  
   struct sockaddr_in si_other;
   int slen = sizeof(si_other);
-  char *s = buf;
   int l;
   int my_socket;
   
@@ -378,15 +382,10 @@ static int socket_udp_send(int socket_fd, void *buf, int size, char *peer_addr,
       exit(1);
   }
 
-  while (size) {
-    l = sendto(my_socket, s, size, 0, (struct sockaddr *) &si_other, slen);
+  l = sendto(my_socket, buf, size, 0, (struct sockaddr *) &si_other, slen);
   if (l == -1) goto error;
-    if (l == 0) { printf("\n\n\nERROR PROTO_AGENT: %s:%d: this cannot happen, normally...\n", __FILE__, __LINE__); abort(); }
-    size -= l;
-    s += l;
-  }
   
-  return 0;
+  return l;
 error:
   LOG_E(MAC,"socket_udp_send: ERROR: %s\n", strerror(errno));
   return -1;
@@ -398,20 +397,14 @@ static int socket_udp_receive(int socket_fd, void *buf, int size)
 
   struct sockaddr_in client;
   socklen_t slen;
-  char *s = buf;
   int   l;
 
-  while (size) {
-    l = recvfrom(socket_fd, s, size, 0, (struct sockaddr *) &client, &slen);
-    getsockname(socket_fd, (struct sockaddr *)&client, &slen);
-    LOG_D(PROTO_AGENT, "Got message from src port: %u\n", ntohs(client.sin_port));
+  l = recvfrom(socket_fd, buf, size, 0, (struct sockaddr *) &client, &slen);
+  //getsockname(socket_fd, (struct sockaddr *)&client, &slen);
   if (l == -1) goto error;
   if (l == 0) goto socket_closed;
-    size -= l;
-    s += l;
-  }
 
-  return ntohs(client.sin_port);
+  return l;
 
 error:
   LOG_E(MAC, "socket_udp_receive: ERROR: %s\n", strerror(errno));
@@ -476,18 +469,18 @@ socket_closed:
 /*
  * return -1 on error and 0 if the sending was fine
  */
-int link_send_packet(socket_link_t *link, void *data, int size, uint16_t proto_type, char *peer_addr, int port)
+int link_send_packet(socket_link_t *link, void *data, int size, uint16_t proto_type, const char *peer_addr, int peer_port)
 {
   char sizebuf[4];
   int32_t s = size;
 
+  if ((proto_type == 0) || (proto_type == 2))
+  {
     /* send the size first, maximum is 2^31 bytes */
     sizebuf[0] = (s >> 24) & 255;
     sizebuf[1] = (s >> 16) & 255;
     sizebuf[2] = (s >> 8) & 255;
     sizebuf[3] = s & 255;
-  if ((proto_type == 0) || (proto_type == 2))
-  {
     if (socket_send(link->socket_fd, sizebuf, 4) == -1)
       goto error;
 
@@ -496,28 +489,17 @@ int link_send_packet(socket_link_t *link, void *data, int size, uint16_t proto_t
     if (socket_send(link->socket_fd, data, size) == -1)
       goto error;
 
-    link->bytes_sent += size;
-    link->packets_sent++;
   }
   else if (proto_type == 1 )
   {
-    while (link->peer_port == 0)
-    {
-      sleep(0.1);
-    }
-    LOG_D(PROTO_AGENT, "peer port is %d", link->peer_port);
-    if (socket_udp_send(link->socket_fd, sizebuf, 4, peer_addr, link->peer_port) == -1)
+    /* UDP is connectionless -> only send the data */
+    if (socket_udp_send(link->socket_fd, data, size, peer_addr, peer_port) == -1)
       goto error;
 
-    LOG_I(PROTO_AGENT,"sent 4 bytes over the channel\n");
-    link->bytes_sent += 4;
-
-    if (socket_udp_send(link->socket_fd, data, size, peer_addr, link->peer_port) == -1)
-      goto error;
+  }
 
   link->bytes_sent += size;
   link->packets_sent++;
-  }
 
   return 0;
 
@@ -529,27 +511,17 @@ error:
  * return -1 on error and 0 if the sending was fine
  */
 
-int link_receive_packet(socket_link_t *link, void **ret_data, int *ret_size, uint16_t proto_type, char *peer_addr, int port)
+int link_receive_packet(socket_link_t *link, void **ret_data, int *ret_size, uint16_t proto_type)
 {
   unsigned char sizebuf[4];
-  int32_t       size;
+  int32_t       size = 0;
   void          *data = NULL;
   
-  int peer_port = 0;
   /* received the size first, maximum is 2^31 bytes */
   if ((proto_type == 0) || (proto_type == 2))
   {
     if (socket_receive(link->socket_fd, sizebuf, 4) == -1)
       goto error;
-  }
-  else if (proto_type == 1)
-  {
-      /* received the size first, maximum is 2^31 bytes */
-    peer_port = socket_udp_receive(link->socket_fd, sizebuf, 4);
-      if ( peer_port == -1)
-        goto error;
-    if (peer_port == 0) link->peer_port = peer_port;
-  }
 
     size = (sizebuf[0] << 24) |
            (sizebuf[1] << 16) |
@@ -558,21 +530,28 @@ int link_receive_packet(socket_link_t *link, void **ret_data, int *ret_size, uin
 
     link->bytes_received += 4;
 
-
     data = malloc(size);
     if (data == NULL) {
       LOG_E(MAC, "%s:%d: out of memory\n", __FILE__, __LINE__);
       goto error;
     }
-  if ((proto_type == 0) || (proto_type == 2))
-  {
 
     if (socket_receive(link->socket_fd, data, size) == -1)
       goto error;
   }
   else if (proto_type == 1)
   {
-    if (socket_udp_receive(link->socket_fd, data, size) == -1)
+    /* we get a single packet (no size, UDP could lose it). Therefore, prepare
+     * for the maximum UDP packet size */
+    size = 65535;
+    data = malloc(size);
+    if (data == NULL) {
+      LOG_E(MAC, "%s:%d: out of memory\n", __FILE__, __LINE__);
+      goto error;
+    }
+
+    size = socket_udp_receive(link->socket_fd, data, size);
+    if (size < 0)
       goto error;
   }
 

openair2/UTIL/ASYNC_IF/socket_link.h

@@ -48,12 +48,13 @@ typedef struct {
 
 socket_link_t *new_link_server(int port);
 socket_link_t *new_link_client(const char *server, int port);
-socket_link_t *new_link_udp_server(int port);
+/* setting bind_addr to NULL binds server to INADDR_ANY */
+socket_link_t *new_link_udp_server(const char *bind_addr, int bind_port);
 socket_link_t *new_link_udp_client(const char *server, int port);
 socket_link_t *new_link_sctp_server(int port);
 socket_link_t *new_link_sctp_client(const char *server, int port);
-int link_send_packet(socket_link_t *link, void *data, int size, uint16_t proto_type, char *peer_addr, int port);
-int link_receive_packet(socket_link_t *link, void **data, int *size, uint16_t proto_type, char *peer_addr, int port);
+int link_send_packet(socket_link_t *link, void *data, int size, uint16_t proto_type, const char *peer_addr, int port);
+int link_receive_packet(socket_link_t *link, void **data, int *size, uint16_t proto_type);
 int close_link(socket_link_t *link);