From 941c2e1cd1e62387d1e876739b5e6b0c46fef332 Mon Sep 17 00:00:00 2001
From: Robert Watson <rwatson@FreeBSD.org>
Date: Sun, 21 Jun 2009 10:10:44 +0000
Subject: [PATCH] Remove historical support for capturing IPX packets in the
 output path using raw IPX sockets.  While functional, this support is
 disabled using a flag that can't be changed from userspace, and google
 reveals no documentation or use of that flag anywhere.  This eliminates a
 potential lock order reversal and code reentrance issue in which the output
 path reentered the input path in IPX.

An alternative to removal would be to use the netisr, as a comment I
added in 2005 suggests.  While this change is fairly straight-forward,
the lack of any consumers or the easy possibility of consumers (kernel
modification and recompile required) suggests that this is simply an
unused feature.

Update README to remove this TODO, and a TODO regarding IPX/IP
encapsulation which was also removed a few years ago.

MFC after:	1 week
---
 sys/netipx/README         |  8 -------
 sys/netipx/ipx_input.c    | 50 ---------------------------------------
 sys/netipx/ipx_outputfl.c |  8 -------
 sys/netipx/ipx_var.h      |  1 -
 4 files changed, 67 deletions(-)

diff --git a/sys/netipx/README b/sys/netipx/README
index a067daf877d..c05b4e9c9b6 100644
--- a/sys/netipx/README
+++ b/sys/netipx/README
@@ -39,11 +39,3 @@ Modifications Copyright (c) 2004-2006 Robert N. M. Watson
     but unsent data.  As with TCP, it should instead grab its own
     reference to the socket so that it is not released, as hold onto it
     until the data transfer is complete.
-
-(3) Raw socket capture of IPX output intercepts packets in the SPX output
-    routine in order to feed them back into the raw socket.  This results
-    in recursion into the socket code in the transmit path; instead,
-    captured packets should be fed into a netisr that reinjects them into
-    raw sockets from a new (asynchronous) context.
-
-(4) IPX over IP encapsulation needs work to make it properly MPSAFE.
diff --git a/sys/netipx/ipx_input.c b/sys/netipx/ipx_input.c
index 2a0980a4ff3..f046e2304fb 100644
--- a/sys/netipx/ipx_input.c
+++ b/sys/netipx/ipx_input.c
@@ -452,53 +452,3 @@ ipx_undo_route(struct route *ro)
 		RTFREE(ro->ro_rt);
 	}
 }
-
-/*
- * XXXRW: This code should be run in its own netisr dispatch to avoid a call
- * back into the socket code from the IPX output path.
- */
-void
-ipx_watch_output(struct mbuf *m, struct ifnet *ifp)
-{
-	struct ipxpcb *ipxp;
-	struct ifaddr *ifa;
-	struct ipx_ifaddr *ia;
-
-	/*
-	 * Give any raw listeners a crack at the packet
-	 */
-	IPX_LIST_LOCK();
-	LIST_FOREACH(ipxp, &ipxrawpcb_list, ipxp_list) {
-		struct mbuf *m0 = m_copy(m, 0, (int)M_COPYALL);
-		if (m0 != NULL) {
-			struct ipx *ipx;
-
-			M_PREPEND(m0, sizeof(*ipx), M_DONTWAIT);
-			if (m0 == NULL)
-				continue;
-			ipx = mtod(m0, struct ipx *);
-			ipx->ipx_sna.x_net = ipx_zeronet;
-			for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
-				if (ifp == ia->ia_ifp)
-					break;
-			if (ia == NULL)
-				ipx->ipx_sna.x_host = ipx_zerohost;
-			else
-				ipx->ipx_sna.x_host =
-				    ia->ia_addr.sipx_addr.x_host;
-
-			if (ifp != NULL && (ifp->if_flags & IFF_POINTOPOINT))
-			    TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
-				if (ifa->ifa_addr->sa_family == AF_IPX) {
-				    ipx->ipx_sna = IA_SIPX(ifa)->sipx_addr;
-				    break;
-				}
-			    }
-			ipx->ipx_len = ntohl(m0->m_pkthdr.len);
-			IPX_LOCK(ipxp);
-			ipx_input(m0, ipxp);
-			IPX_UNLOCK(ipxp);
-		}
-	}
-	IPX_LIST_UNLOCK();
-}
diff --git a/sys/netipx/ipx_outputfl.c b/sys/netipx/ipx_outputfl.c
index 9c88f4327ca..f6be964fd1b 100644
--- a/sys/netipx/ipx_outputfl.c
+++ b/sys/netipx/ipx_outputfl.c
@@ -74,8 +74,6 @@ __FBSDID("$FreeBSD$");
 #include <netipx/ipx_if.h>
 #include <netipx/ipx_var.h>
 
-static int ipx_copy_output = 0;
-
 int
 ipx_outputfl(struct mbuf *m0, struct route *ro, int flags)
 {
@@ -150,9 +148,6 @@ gotif:
 
 	if (htons(ipx->ipx_len) <= ifp->if_mtu) {
 		ipxstat.ipxs_localout++;
-		if (ipx_copy_output) {
-			ipx_watch_output(m0, ifp);
-		}
 		error = (*ifp->if_output)(ifp, m0,
 					(struct sockaddr *)dst, ro);
 		goto done;
@@ -161,9 +156,6 @@ gotif:
 		error = EMSGSIZE;
 	}
 bad:
-	if (ipx_copy_output) {
-		ipx_watch_output(m0, ifp);
-	}
 	m_freem(m0);
 done:
 	if (ro == &ipxroute && (flags & IPX_ROUTETOIF) == 0 &&
diff --git a/sys/netipx/ipx_var.h b/sys/netipx/ipx_var.h
index 1c76613f450..7661328532e 100644
--- a/sys/netipx/ipx_var.h
+++ b/sys/netipx/ipx_var.h
@@ -124,7 +124,6 @@ int	ipx_output_type20(struct mbuf *);
 int	ipx_peeraddr(struct socket *so, struct sockaddr **nam);
 void	ipx_printhost(struct ipx_addr *addr);
 int	ipx_sockaddr(struct socket *so, struct sockaddr **nam);
-void	ipx_watch_output(struct mbuf *m, struct ifnet *ifp);
 
 #endif /* _KERNEL */