DEVEL15-rx-user-socket-buffer-sizes-20090110

LICENSE MIT

if the socket buffer size specified by the configuration is too large
to be applied, do not drop down immediately to 32766 bytes.  Instead
try increasingly smaller values trying to find the largest one that
works.  use the same value for the send buf size as well.

(cherry picked from commit 5b0e23567e1ed64f448bb3253ad90d39cad31271)

diff --git a/src/rx/rx_user.c b/src/rx/rx_user.c
index 4ad17f7..43adbb3 100644 (file)
--- a/src/rx/rx_user.c
+++ b/src/rx/rx_user.c
@@ -165,15 +165,26 @@ rxi_GetHostUDPSocket(u_int ahost, u_short port)
 
        len1 = 32766;
        len2 = rx_UdpBufSize;
-       greedy =
-           (setsockopt
-            (socketFd, SOL_SOCKET, SO_RCVBUF, (char *)&len2,
-             sizeof(len2)) >= 0);
-       if (!greedy) {
-           len2 = 32766;       /* fall back to old size... uh-oh! */
-       }
 
-       greedy =
+        /* find the size closest to rx_UdpBufSize that will be accepted */
+        while (!greedy && len2 > len1) {
+            greedy =
+                (setsockopt
+                  (socketFd, SOL_SOCKET, SO_RCVBUF, (char *)&len2,
+                   sizeof(len2)) >= 0);
+            if (!greedy)
+                len2 /= 2;
+        }
+
+        /* but do not let it get smaller than 32K */ 
+        if (len2 < len1)
+            len2 = len1;
+
+        if (len1 < len2)
+            len1 = len2;
+
+
+        greedy =
            (setsockopt
             (socketFd, SOL_SOCKET, SO_SNDBUF, (char *)&len1,
              sizeof(len1)) >= 0)