Fixed bug #22110 (recv() makes receive window update for data that wasn't received by application); added function-like macros to correctly access/change conn->recv_timeout and conn->recv_bufsize

CHANGELOG

@@ -103,6 +103,12 @@ HISTORY
 
   ++ Bugfixes:
 
+  2010-02-09: Simon Goldschmidt
+  * api_lib.c, api_msg.c, sockets.c, api.h, api_msg.h: Fixed bug #22110
+   (recv() makes receive window update for data that wasn't received by
+    application)
+
+
   2010-02-09: Simon Goldschmidt/Stephane Lesage
   * sockets.c: Fixed bug #28853 (lwip_recvfrom() returns 0 on receive time-out
     or any netconn_recv() error)

src/api/api_lib.c

@@ -388,6 +388,7 @@ netconn_recv(struct netconn *conn, struct netbuf **new_buf)
     buf->port = 0;
     buf->addr = NULL;
 
+    if (!netconn_get_noautorecved(conn) || (buf == NULL)) {
       /* Let the stack know that we have taken the data. */
       /* TODO: Speedup: Don't block and wait for the answer here
          (to prevent multiple thread-switches). */
@@ -400,6 +401,7 @@ netconn_recv(struct netconn *conn, struct netbuf **new_buf)
       }
       /* don't care for the return value of do_recv */
       TCPIP_APIMSG(&msg);
+    }
 #endif /* LWIP_TCP */
   } else {
 #if (LWIP_UDP || LWIP_RAW)
@@ -427,6 +429,33 @@ netconn_recv(struct netconn *conn, struct netbuf **new_buf)
   return ERR_OK;
 }
 
+/**
+ * TCP: update the receive window: by calling this, the application
+ * tells the stack that it has processed data and is able to accept
+ * new data.
+ * ATTENTION: use with care, this is mainly used for sockets!
+ * Can only be used when calling netconn_set_noautorecved(conn, 1) before.
+ *
+ * @param conn the netconn for which to update the receive window
+ * @param length amount of data processed (ATTENTION: this must be accurate!)
+ */
+void
+netconn_recved(struct netconn *conn, u32_t length)
+{
+  if ((conn != NULL) && (conn->type == NETCONN_TCP) &&
+      (netconn_get_noautorecved(conn))) {
+    struct api_msg msg;
+    /* Let the stack know that we have taken the data. */
+    /* TODO: Speedup: Don't block and wait for the answer here
+       (to prevent multiple thread-switches). */
+    msg.function = do_recv;
+    msg.msg.conn = conn;
+    msg.msg.msg.r.len = length;
+    /* don't care for the return value of do_recv */
+    TCPIP_APIMSG(&msg);
+  }
+}
+
 /**
  * Send data (in form of a netbuf) to a specific remote IP address and port.
  * Only to be used for UDP and RAW netconns (not TCP).

src/api/api_msg.c

@@ -1102,7 +1102,12 @@ do_recv(struct api_msg_msg *msg)
       } else
 #endif /* TCP_LISTEN_BACKLOG */
       {
-        tcp_recved(msg->conn->pcb.tcp, msg->msg.r.len);
+        u32_t remaining = msg->msg.r.len;
+        do {
+          u16_t recved = (remaining > 0xffff) ? 0xffff : (u16_t)remaining;
+          tcp_recved(msg->conn->pcb.tcp, recved);
+          remaining -= recved;
+        }while(remaining != 0);
       }
     }
   }

src/api/sockets.c

@@ -304,6 +304,8 @@ lwip_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
     return -1;
   }
   LWIP_ASSERT("newconn != NULL", newconn != NULL);
+  /* Prevent automatic window updates, we do this on our own! */
+  netconn_set_noautorecved(newconn, 1);
 
   /* get the IP address and port of the remote host */
   err = netconn_peer(newconn, &naddr, &port);
@@ -519,6 +521,8 @@ lwip_recvfrom(int s, void *mem, size_t len, int flags,
       if (((flags & MSG_DONTWAIT) || netconn_is_nonblocking(sock->conn)) && 
           (sock->rcvevent <= 0)) {
         if (off > 0) {
+          /* update receive window */
+          netconn_recved(sock->conn, (u32_t)off);
           /* already received data, return that */
           sock_set_errno(sock, 0);
           return off;
@@ -536,6 +540,8 @@ lwip_recvfrom(int s, void *mem, size_t len, int flags,
 
       if (err != ERR_OK) {
         if (off > 0) {
+          /* update receive window */
+          netconn_recved(sock->conn, (u32_t)off);
           /* already received data, return that */
           sock_set_errno(sock, 0);
           return off;
@@ -649,6 +655,10 @@ lwip_recvfrom(int s, void *mem, size_t len, int flags,
     }
   } while (!done);
 
+  if (off > 0) {
+    /* update receive window */
+    netconn_recved(sock->conn, (u32_t)off);
+  }
   sock_set_errno(sock, 0);
   return off;
 }
@@ -819,6 +829,10 @@ lwip_socket(int domain, int type, int protocol)
     conn = netconn_new_with_callback(NETCONN_TCP, event_callback);
     LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_socket(%s, SOCK_STREAM, %d) = ",
                                  domain == PF_INET ? "PF_INET" : "UNKNOWN", protocol));
+    if (conn != NULL) {
+      /* Prevent automatic window updates, we do this on our own! */
+      netconn_set_noautorecved(conn, 1);
+    }
     break;
   default:
     LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_socket(%d, %d/UNKNOWN, %d) = -1\n",
@@ -1488,12 +1502,12 @@ lwip_getsockopt_internal(void *arg)
 
 #if LWIP_SO_RCVTIMEO
     case SO_RCVTIMEO:
-      *(int *)optval = sock->conn->recv_timeout;
+      *(int *)optval = netconn_get_recvtimeout(sock->conn);
       break;
 #endif /* LWIP_SO_RCVTIMEO */
 #if LWIP_SO_RCVBUF
     case SO_RCVBUF:
-      *(int *)optval = sock->conn->recv_bufsize;
+      *(int *)optval = netconn_get_recvbufsize(sock->conn);
       break;
 #endif /* LWIP_SO_RCVBUF */
 #if LWIP_UDP
@@ -1833,12 +1847,12 @@ lwip_setsockopt_internal(void *arg)
       break;
 #if LWIP_SO_RCVTIMEO
     case SO_RCVTIMEO:
-      sock->conn->recv_timeout = ( *(int*)optval );
+      netconn_set_recvtimeout(sock->conn, *(int*)optval);
       break;
 #endif /* LWIP_SO_RCVTIMEO */
 #if LWIP_SO_RCVBUF
     case SO_RCVBUF:
-      sock->conn->recv_bufsize = ( *(int*)optval );
+      netconn_set_recvbufsize(sock->conn, *(int*)optval);
       break;
 #endif /* LWIP_SO_RCVBUF */
 #if LWIP_UDP

src/include/lwip/api.h

@@ -69,7 +69,7 @@ extern "C" {
 #define NETCONN_FLAG_IN_NONBLOCKING_CONNECT  0x04
 /** If this is set, a TCP netconn must call netconn_recved() to update
     the TCP receive window (done automatically if not set). */
-#define NETCONN_FLAG_UPDATE_TCPWIN_MANUALLY   0x08
+#define NETCONN_FLAG_NO_AUTO_RECVED          0x08
 
 
 /* Helpers to process several netconn_types by the same code */
@@ -214,6 +214,7 @@ err_t   netconn_listen_with_backlog(struct netconn *conn, u8_t backlog);
 #define netconn_listen(conn) netconn_listen_with_backlog(conn, TCP_DEFAULT_LISTEN_BACKLOG)
 err_t   netconn_accept(struct netconn *conn, struct netconn **new_conn);
 err_t   netconn_recv(struct netconn *conn, struct netbuf **new_buf);
+void    netconn_recved(struct netconn *conn, u32_t length);
 err_t   netconn_sendto(struct netconn *conn, struct netbuf *buf,
                        ip_addr_t *addr, u16_t port);
 err_t   netconn_send(struct netconn *conn, struct netbuf *buf);
@@ -240,6 +241,27 @@ err_t   netconn_gethostbyname(const char *name, ip_addr_t *addr);
 /** Get the blocking status of netconn calls (@todo: write/send is missing) */
 #define netconn_is_nonblocking(conn)        (((conn)->flags & NETCONN_FLAG_NON_BLOCKING) != 0)
 
+/** TCP: Set the no-auto-recved status of netconn calls (see NETCONN_FLAG_NO_AUTO_RECVED) */
+#define netconn_set_noautorecved(conn, val)  do { if(val) { \
+  (conn)->flags |= NETCONN_FLAG_NO_AUTO_RECVED; \
+} else { \
+  (conn)->flags &= ~ NETCONN_FLAG_NO_AUTO_RECVED; }} while(0)
+/** TCP: Get the no-auto-recved status of netconn calls (see NETCONN_FLAG_NO_AUTO_RECVED) */
+#define netconn_get_noautorecved(conn)        (((conn)->flags & NETCONN_FLAG_NO_AUTO_RECVED) != 0)
+
+#if LWIP_SO_RCVTIMEO
+/** Set the receive timeout in miliseconds */
+#define netconn_set_recvtimeout(conn, timeout)      ((conn)->recv_timeout = (timeout))
+/** Get the receive timeout in miliseconds */
+#define netconn_get_recvtimeout(conn)               ((conn)->recv_timeout)
+#endif /* LWIP_SO_RCVTIMEO */
+#if LWIP_SO_RCVBUF
+/** Set the receive buffer in bytes */
+#define netconn_set_recvbufsize(conn, recvbufsize)  ((conn)->recv_bufsize = (recvbufsize))
+/** Get the receive buffer in bytes */
+#define netconn_get_recvbufsize(conn)               ((conn)->recv_bufsize)
+#endif /* LWIP_SO_RCVBUF*/
+
 #ifdef __cplusplus
 }
 #endif

src/include/lwip/api_msg.h

@@ -87,7 +87,7 @@ struct api_msg_msg {
     } w;
     /** used for do_recv */
     struct {
-      u16_t len;
+      u32_t len;
     } r;
 #if LWIP_IGMP
     /** used for do_join_leave_group */