X-Git-Url: https://git.decadent.org.uk/gitweb/?p=nfs-utils.git;a=blobdiff_plain;f=support%2Fnfs%2Fsvc_socket.c;h=f56f310fb5c4744ca8a8bcccb5d4ae265b7889c6;hp=d712cabbba387967d21275b546acafa3dc6be3f7;hb=12544486ef2de86e4f2dfc920cd2860fb81658d1;hpb=3d7e64fd2a1e226a5169c2fde2852bfcca07845f

diff --git a/support/nfs/svc_socket.c b/support/nfs/svc_socket.c
index d712cab..f56f310 100644
--- a/support/nfs/svc_socket.c
+++ b/support/nfs/svc_socket.c
@@ -13,8 +13,8 @@
 
    You should have received a copy of the GNU Lesser General Public
    License along with the GNU C Library; if not, write to the Free
-   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
-   02111-1307 USA.  */
+   Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+   Boston, MA 0211-1301 USA */
 
 #include <stdio.h>
 #include <string.h>
@@ -35,14 +35,43 @@
 # define __close(f)		close ((f))
 #endif
 
+int getservport(u_long number, const char *proto)
+{
+	char rpcdata[1024], servdata[1024];
+	struct rpcent rpcbuf, *rpcp;
+	struct servent servbuf, *servp = NULL;
+	int ret;
+
+	ret = getrpcbynumber_r(number, &rpcbuf, rpcdata, sizeof rpcdata,
+				&rpcp);
+	if (ret == 0 && rpcp != NULL) {
+		/* First try name.  */
+		ret = getservbyname_r(rpcp->r_name, proto, &servbuf, servdata,
+					sizeof servdata, &servp);
+		if ((ret != 0 || servp == NULL) && rpcp->r_aliases) {
+			const char **a;
+
+			/* Then we try aliases.  */
+			for (a = (const char **) rpcp->r_aliases; *a != NULL; a++) {
+				ret = getservbyname_r(*a, proto, &servbuf, servdata,
+							sizeof servdata, &servp);
+				if (ret == 0 && servp != NULL)
+					break;
+			}
+		}
+	}
+
+	if (ret == 0 && servp != NULL)
+		return ntohs(servp->s_port);
+
+	return 0;
+}
+
 static int
 svc_socket (u_long number, int type, int protocol, int reuse)
 {
   struct sockaddr_in addr;
   socklen_t len = sizeof (struct sockaddr_in);
-  char rpcdata [1024], servdata [1024];
-  struct rpcent rpcbuf, *rpcp;
-  struct servent servbuf, *servp = NULL;
   int sock, ret;
   const char *proto = protocol == IPPROTO_TCP ? "tcp" : "udp";
 
@@ -66,58 +95,31 @@ svc_socket (u_long number, int type, int protocol, int reuse)
 
   memset (&addr, 0, sizeof (addr));
   addr.sin_family = AF_INET;
+  addr.sin_port = htons(getservport(number, proto));
 
-  ret = getrpcbynumber_r (number, &rpcbuf, rpcdata, sizeof rpcdata,
-			  &rpcp);
-  if (ret == 0 && rpcp != NULL)
-    {
-      /* First try name.  */
-      ret = getservbyname_r (rpcp->r_name, proto, &servbuf, servdata,
-			     sizeof servdata, &servp);
-      if ((ret != 0 || servp == NULL) && rpcp->r_aliases)
-	{
-	  const char **a;
-
-	  /* Then we try aliases.  */
-	  for (a = (const char **) rpcp->r_aliases; *a != NULL; a++) 
-	    {
-	      ret = getservbyname_r (*a, proto, &servbuf, servdata,
-				     sizeof servdata, &servp);
-	      if (ret == 0 && servp != NULL)
-		break;
-	    }
-	}
-    }
-
-  if (ret == 0 && servp != NULL)
-    {
-      addr.sin_port = servp->s_port;
-      if (bind (sock, (struct sockaddr *) &addr, len) < 0)
-	{
-	  perror (_("svc_socket: bind problem"));
-	  (void) __close (sock);
-	  sock = -1;
-	}
-    }
-  else
+  if (bind(sock, (struct sockaddr *) &addr, len) < 0)
     {
-      if (bindresvport (sock, &addr))
-	{
-	  addr.sin_port = 0;
-	  if (bind (sock, (struct sockaddr *) &addr, len) < 0)
-	    {
-	      perror (_("svc_socket: bind problem"));
-	      (void) __close (sock);
-	      sock = -1;
-	    }
-	}
+      perror (_("svc_socket: bind problem"));
+      (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 +151,9 @@ 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 +168,7 @@ 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;