Handle a bug that LBL thought was fixed in 4.4BSD but wasn't: send()

on a socket with a pending error doesn't reset the error, so the socket
is effectively useless.  Use getsockopt(...SO_ERROR...) to clear the
error status.  The kernel should also be patched, but this patch is
required for backwards compatibility.

1 files changed, 117 insertions, 0 deletions

diff --git a/mbone/vat/files/patch-af b/mbone/vat/files/patch-af
new file mode 100644
index 000000000000..6b73cca9f5c8
--- /dev/null
+++ b/mbone/vat/files/patch-af
@@ -0,0 +1,117 @@
+--- net.cc.orig	1997/10/07 19:07:01
++++ net.cc	1998/01/26 22:21:41
+@@ -163,46 +163,48 @@
+ {
+ 	int cc = ::send(fd, (char*)buf, len, 0);
+ 	if (cc < 0) {
+-		switch (errno) {
++		/*
++		 * Due to a bug in kern/uipc_socket.c, on several
++		 * systems, datagram sockets incorrectly persist
++		 * in an error state on receipt of any ICMP
++		 * error.  This causes unicast connection
++		 * rendezvous problems, and worse, multicast
++		 * transmission problems because several systems
++		 * incorrectly send port unreachables for 
++		 * multicast destinations.  Our work around
++		 * is to call getsockopt(..., SO_ERROR, ...)
++		 * which resets so->so_error.
++		 *
++		 * This bug originated at CSRG in Berkeley
++		 * and was present in the BSD Reno networking
++		 * code release.  It has since been fixed
++		 * in OSF-3.x.  It is know to remain
++		 * in 4.4BSD and AIX-4.1.3.
++		 *
++		 * A fix is to change the following lines from
++		 * kern/uipc_socket.c:
++		 *
++		 *	if (so_serror)
++		 *		snderr(so->so_error);
++		 *
++		 * to:
++		 *
++		 *	if (so->so_error) {
++		 * 		error = so->so_error;
++		 *		so->so_error = 0;
++		 *		splx(s);
++		 *		goto release;
++		 *	}
++		 *
++		 */
++		int err, errlen = sizeof(err), savederrno;
++
++		savederrno = errno;
++		getsockopt(fd, SOL_SOCKET, SO_ERROR, &err,
++			&errlen);
++		switch (savederrno) {
+ 		case ECONNREFUSED:
+ 			/* no one listening at some site - ignore */
+-#if defined(__osf__) || defined(_AIX)
+-			/*
+-			 * Due to a bug in kern/uipc_socket.c, on several
+-			 * systems, datagram sockets incorrectly persist
+-			 * in an error state on receipt of an ICMP
+-			 * port-unreachable.  This causes unicast connection
+-			 * rendezvous problems, and worse, multicast
+-			 * transmission problems because several systems
+-			 * incorrectly send port unreachables for 
+-			 * multicast destinations.  Our work around
+-			 * is to simply close and reopen the socket
+-			 * (by calling reset() below).
+-			 *
+-			 * This bug originated at CSRG in Berkeley
+-			 * and was present in the BSD Reno networking
+-			 * code release.  It has since been fixed
+-			 * in 4.4BSD and OSF-3.x.  It is know to remain
+-			 * in AIX-4.1.3.
+-			 *
+-			 * A fix is to change the following lines from
+-			 * kern/uipc_socket.c:
+-			 *
+-			 *	if (so_serror)
+-			 *		snderr(so->so_error);
+-			 *
+-			 * to:
+-			 *
+-			 *	if (so->so_error) {
+-			 * 		error = so->so_error;
+-			 *		so->so_error = 0;
+-			 *		splx(s);
+-			 *		goto release;
+-			 *	}
+-			 *
+-			 */
+-			reset();
+-#endif
+ 			break;
+ 
+ 		case ENETUNREACH:
+@@ -217,7 +219,7 @@
+ 			 * icmp unreachable, so we should be able to
+ 			 * send now.
+ 			 */
+-			(void)::send(ssock_, (char*)buf, len, 0);
++			(void)::send(fd, (char*)buf, len, 0);
+ 			break;
+ 
+ 		default:
+@@ -264,12 +266,14 @@
+ 	}
+ 	int cc = ::sendmsg(ssock_, (msghdr*)&mh, 0);
+ 	if (cc < 0) {
+-		switch (errno) {
++		int err, errlen = sizeof(err), savederrno;
++
++		savederrno = errno;
++		getsockopt(ssock_, SOL_SOCKET, SO_ERROR, &err,
++			&errlen);
++		switch (savederrno) {
+ 		case ECONNREFUSED:
+ 			/* no one listening at some site - ignore */
+-#if defined(__osf__) || defined(_AIX)
+-			reset();
+-#endif
+ 			break;
+ 
+ 		case ENETUNREACH: