X-Git-Url: https://git.decadent.org.uk/gitweb/?p=nfs-utils.git;a=blobdiff_plain;f=support%2Fnfs%2Fsvc_socket.c;h=03a53256c1f4469ec5a36839672eaa6a5a5f0c28;hp=888c915931b000f42d86d026bc94e86ed8329139;hb=0cdfd35cecc17eb1927f15d33205e43ec66675f2;hpb=11d34d11153df198103a57291937ea9ff8b7356e

diff --git a/support/nfs/svc_socket.c b/support/nfs/svc_socket.c
index 888c915..03a5325 100644
--- a/support/nfs/svc_socket.c
+++ b/support/nfs/svc_socket.c
@@ -42,7 +42,7 @@ svc_socket (u_long number, int type, int protocol, int reuse)
   socklen_t len = sizeof (struct sockaddr_in);
   char rpcdata [1024], servdata [1024];
   struct rpcent rpcbuf, *rpcp;
-  struct servent servbuf, *servp;
+  struct servent servbuf, *servp = NULL;
   int sock, ret;
   const char *proto = protocol == IPPROTO_TCP ? "tcp" : "udp";
 
@@ -64,7 +64,7 @@ svc_socket (u_long number, int type, int protocol, int reuse)
 	}
     }
 
-  __bzero ((char *) &addr, sizeof (addr));
+  memset (&addr, 0, sizeof (addr));
   addr.sin_family = AF_INET;
 
   ret = getrpcbynumber_r (number, &rpcbuf, rpcdata, sizeof rpcdata,
@@ -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)
 	  {
@@ -149,9 +157,9 @@ svctcp_socket (u_long number, int reuse)
  * Create and bind a UDP socket based on program number
  */
 int
-svcudp_socket (u_long number, int reuse)
+svcudp_socket (u_long number)
 {
-  return svc_socket (number, SOCK_DGRAM, IPPROTO_UDP, reuse);
+  return svc_socket (number, SOCK_DGRAM, IPPROTO_UDP, FALSE);
 }
 
 #ifdef TEST
@@ -166,7 +174,7 @@ check (u_long number, u_short port, int protocol, int reuse)
   if (protocol == IPPROTO_TCP)
     socket = svctcp_socket (number, reuse);
   else
-    socket = svcudp_socket (number, reuse);
+    socket = svcudp_socket (number);
 
   if (socket < 0)
     return 1;