api.h, api_lib.c, api_msg.c, sockets.c, opt.h: add SO_RCVBUF option for UDP & RAW netconn. You need to set LWIP_SO_RCVBUF=1 in your lwipopts.h (it's disabled by default). Netconn API users can use the netconn_recv_bufsize macro to access it. This is a first release which have to be improve for TCP. Note it used the netconn::recv_avail which need to be more "thread-safe" (note there is already the problem for FIONREAD with lwip_ioctl/ioctlsocket).

CHANGELOG

@@ -19,6 +19,14 @@ HISTORY
 
   ++ New features:
 
+  2007-11-03 Frédéric Bernon
+  * api.h, api_lib.c, api_msg.c, sockets.c, opt.h: add SO_RCVBUF option for UDP &
+    RAW netconn. You need to set LWIP_SO_RCVBUF=1 in your lwipopts.h (it's disabled
+    by default). Netconn API users can use the netconn_recv_bufsize macro to access
+    it. This is a first release which have to be improve for TCP. Note it used the
+    netconn::recv_avail which need to be more "thread-safe" (note there is already
+    the problem for FIONREAD with lwip_ioctl/ioctlsocket).
+
   2007-11-01 Frédéric Bernon, Marc Chaland
   * sockets.h, sockets.c, api.h, api_lib.c, api_msg.h, api_msg.c, tcp.h, tcp_out.c:
     Integrate "patch #6250 : MSG_MORE flag for send". MSG_MORE is used at socket api

src/api/api_lib.c

@@ -89,6 +89,9 @@ netconn *netconn_new_with_proto_and_callback(enum netconn_type t, u8_t proto,
 #if LWIP_SO_RCVTIMEO
   conn->recv_timeout = 0;
 #endif /* LWIP_SO_RCVTIMEO */
+#if LWIP_SO_RCVBUF
+  conn->recv_bufsize = INT_MAX;
+#endif /* LWIP_SO_RCVBUF */
 
   msg.function = do_newconn;
   msg.msg.msg.n.proto = proto;

src/api/api_msg.c

@@ -69,7 +69,12 @@ recv_raw(void *arg, struct raw_pcb *pcb, struct pbuf *p,
 
   conn = arg;
 
+#if LWIP_SO_RCVBUF
+  if ((conn != NULL) && (conn->recvmbox != SYS_MBOX_NULL) &&
+      (((int)(conn->recv_avail) + (int)(p->tot_len)) <= conn->recv_bufsize)) {
+#else  /* LWIP_SO_RCVBUF */
   if ((conn != NULL) && (conn->recvmbox != SYS_MBOX_NULL)) {
+#endif /* LWIP_SO_RCVBUF */
     buf = memp_malloc(MEMP_NETBUF);
     if (buf == NULL) {
       return 0;
@@ -108,7 +113,12 @@ recv_udp(void *arg, struct udp_pcb *pcb, struct pbuf *p,
 
   conn = arg;
 
+#if LWIP_SO_RCVBUF
+  if ((conn == NULL) || (conn->recvmbox == SYS_MBOX_NULL) ||
+      (((int)(conn->recv_avail) + (int)(p->tot_len)) > conn->recv_bufsize)) {
+#else  /* LWIP_SO_RCVBUF */
   if ((conn == NULL) || (conn->recvmbox == SYS_MBOX_NULL)) {
+#endif /* LWIP_SO_RCVBUF */
     pbuf_free(p);
     return;
   }
@@ -340,6 +350,9 @@ accept_function(void *arg, struct tcp_pcb *newpcb, err_t err)
 #if LWIP_SO_RCVTIMEO
   newconn->recv_timeout = 0;
 #endif /* LWIP_SO_RCVTIMEO */
+#if LWIP_SO_RCVBUF
+  newconn->recv_bufsize = INT_MAX;
+#endif /* LWIP_SO_RCVBUF */
 
   sys_mbox_post(conn->acceptmbox, newconn);
   return ERR_OK;

src/api/sockets.c

@@ -1044,8 +1044,10 @@ lwip_getsockopt(int s, int level, int optname, void *optval, socklen_t *optlen)
 #if LWIP_SO_RCVTIMEO
     case SO_RCVTIMEO:
 #endif /* LWIP_SO_RCVTIMEO */
+#if LWIP_SO_RCVBUF
+    case SO_RCVBUF:
+#endif /* LWIP_SO_RCVBUF */
     /* UNIMPL case SO_OOBINLINE: */
-    /* UNIMPL case SO_RCVBUF: */
     /* UNIMPL case SO_SNDBUF: */
     /* UNIMPL case SO_RCVLOWAT: */
     /* UNIMPL case SO_SNDLOWAT: */
@@ -1275,6 +1277,11 @@ lwip_getsockopt_internal(void *arg)
       *(int *)optval = sock->conn->recv_timeout;
       break;
 #endif /* LWIP_SO_RCVTIMEO */
+#if LWIP_SO_RCVBUF
+    case SO_RCVBUF:
+      *(int *)optval = sock->conn->recv_bufsize;
+      break;
+#endif /* LWIP_SO_RCVBUF */
 #if LWIP_UDP
     case SO_NO_CHECK:
       *(int*)optval = (udp_flags(sock->conn->pcb.udp) & UDP_FLAGS_NOCHKSUM) ? 1 : 0;
@@ -1399,8 +1406,10 @@ lwip_setsockopt(int s, int level, int optname, const void *optval, socklen_t opt
 #if LWIP_SO_RCVTIMEO
     case SO_RCVTIMEO:
 #endif /* LWIP_SO_RCVTIMEO */
+#if LWIP_SO_RCVBUF
+    case SO_RCVBUF:
+#endif /* LWIP_SO_RCVBUF */
     /* UNIMPL case SO_OOBINLINE: */
-    /* UNIMPL case SO_RCVBUF: */
     /* UNIMPL case SO_SNDBUF: */
     /* UNIMPL case SO_RCVLOWAT: */
     /* UNIMPL case SO_SNDLOWAT: */
@@ -1613,6 +1622,11 @@ lwip_setsockopt_internal(void *arg)
       sock->conn->recv_timeout = ( *(int*)optval );
       break;
 #endif /* LWIP_SO_RCVTIMEO */
+#if LWIP_SO_RCVBUF
+    case SO_RCVBUF:
+      sock->conn->recv_bufsize = ( *(int*)optval );
+      break;
+#endif /* LWIP_SO_RCVBUF */
 #if LWIP_UDP
     case SO_NO_CHECK:
       if (*(int*)optval) {

src/include/lwip/api.h

@@ -114,6 +114,9 @@ struct netconn {
 #if LWIP_SO_RCVTIMEO
   int recv_timeout;
 #endif /* LWIP_SO_RCVTIMEO */
+#if LWIP_SO_RCVBUF
+  int recv_bufsize;
+#endif /* LWIP_SO_RCVBUF */
   u16_t recv_avail;
   /** TCP: when data passed to netconn_write doesn't fit into the send buffer,
       this temporarily stores the message. */
@@ -177,6 +180,7 @@ err_t             netconn_join_leave_group (struct netconn *conn,
 #endif /* LWIP_IGMP */
 
 #define netconn_err(conn)          ((conn)->err)
+#define netconn_recv_bufsize(conn) ((conn)->recv_bufsize)
 
 #ifdef __cplusplus
 }

src/include/lwip/opt.h

@@ -927,6 +927,13 @@
 #define LWIP_SO_RCVTIMEO                0
 #endif
 
+/**
+ * LWIP_SO_RCVBUF==1: Enable SO_RCVBUF processing.
+ */
+#ifndef LWIP_SO_RCVBUF
+#define LWIP_SO_RCVBUF                  0
+#endif
+
 /**
  * SO_REUSE==1: Enable SO_REUSEADDR and SO_REUSEPORT options. DO NOT USE!
  */