X-Git-Url: https://git.decadent.org.uk/gitweb/?p=nfs-utils.git;a=blobdiff_plain;f=support%2Fnfs%2Fsvc_socket.c;h=f44217a404821dcd059e8374531d3ac32c12d1fa;hp=d712cabbba387967d21275b546acafa3dc6be3f7;hb=2bb403d1547790e731e5b151f9ef41880a6eb6c7;hpb=3d7e64fd2a1e226a5169c2fde2852bfcca07845f

diff --git a/support/nfs/svc_socket.c b/support/nfs/svc_socket.c
index d712cab..f44217a 100644
--- a/support/nfs/svc_socket.c
+++ b/support/nfs/svc_socket.c
@@ -101,8 +101,6 @@ svc_socket (u_long number, int type, int protocol, int reuse)
     }
   else
     {
-      if (bindresvport (sock, &addr))
-	{
 	  addr.sin_port = 0;
 	  if (bind (sock, (struct sockaddr *) &addr, len) < 0)
 	    {
@@ -110,14 +108,24 @@ svc_socket (u_long number, int type, int protocol, int reuse)
 	      (void) __close (sock);
 	      sock = -1;
 	    }
-	}
     }
 
-  if (sock >= 0 && protocol == IPPROTO_TCP)
+  if (sock >= 0)
     {
-	/* Make the TCP rendezvous socket non-block to avoid
-	 * problems with blocking in accept() after a spurious
-	 * wakeup from the kernel */
+	    /* This socket might be shared among multiple processes
+	     * if mountd is run multi-threaded.  So it is safest to
+	     * make it non-blocking, else all threads might wake
+	     * one will get the data, and the others will block
+	     * indefinitely.
+	     * In all cases, transaction on this socket are atomic
+	     * (accept for TCP, packet-read and packet-write for UDP)
+	     * so O_NONBLOCK will not confuse unprepared code causing
+	     * it to corrupt messages.
+	     * It generally safest to have O_NONBLOCK when doing an accept
+	     * as if we get a RST after the SYN and before accept runs,
+	     * we can block despite being told there was an acceptable
+	     * connection.
+	     */
 	int flags;
 	if ((flags = fcntl(sock, F_GETFL)) < 0)
 	  {
@@ -151,7 +159,7 @@ svctcp_socket (u_long number, int reuse)
 int
 svcudp_socket (u_long number, int reuse)
 {
-  return svc_socket (number, SOCK_DGRAM, IPPROTO_UDP, reuse);
+  return svc_socket (number, SOCK_DGRAM, IPPROTO_UDP, 0);
 }
 
 #ifdef TEST