Go through the loopback code with a broom..

Remove lots'o'hacks.
looutput is now static.

Other callers who want to use loopback to allow shortcutting
should call the special entrypoint for this, if_simloop(), which is
specifically designed for this purpose. Using looutput for this purpose
was problematic, particularly with bpf and trying to keep track
of whether one should be using the charateristics of the loopback interface
or the interface (e.g. if_ethersubr.c) that was requesting the loopback.
There was a whole class of errors due to this mis-use each of which had
hacks to cover them up.

Consists largly of hack removal :-)

1 files changed, 30 insertions, 60 deletions

diff --git a/sys/net/if_fddisubr.c b/sys/net/if_fddisubr.c
index 2450abb..ee4e847 100644
--- a/sys/net/if_fddisubr.c
+++ b/sys/net/if_fddisubr.c
@@ -33,7 +33,7 @@
  * SUCH DAMAGE.
  *
  *	from: if_ethersubr.c,v 1.5 1994/12/13 22:31:45 wollman Exp
- * $Id: if_fddisubr.c,v 1.29 1998/05/20 14:08:43 dufault Exp $
+ * $Id: if_fddisubr.c,v 1.30 1998/05/21 00:33:16 dg Exp $
  */
 
 #include "opt_atalk.h"
@@ -139,12 +139,11 @@ fddi_output(ifp, m0, dst, rt0)
 	struct rtentry *rt0;
 {
 	u_int16_t type;
-	int s, error = 0;
+	int s, loop_copy = 0, error = 0;
  	u_char edst[6];
 	register struct mbuf *m = m0;
 	register struct rtentry *rt;
 	register struct fddi_header *fh;
-	struct mbuf *mcopy = (struct mbuf *)0;
 	struct arpcom *ac = (struct arpcom *)ifp;
 
 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING))
@@ -186,47 +185,22 @@ fddi_output(ifp, m0, dst, rt0)
 		if (!arpresolve(ac, m, &((struct sockaddr_in *)dst)->sin_addr, edst, &usetrailers))
 			return (0);	/* if not yet resolved */
 #endif
-		/* If broadcasting on a simplex interface, loopback a copy */
-		if ((m->m_flags & M_BCAST) && (ifp->if_flags & IFF_SIMPLEX))
-			mcopy = m_copy(m, 0, (int)M_COPYALL);
 		type = htons(ETHERTYPE_IP);
 		break;
 	}
 #endif
 #ifdef IPX
 	case AF_IPX:
-		{
-		struct ifaddr *ia;
-
 		type = htons(ETHERTYPE_IPX);
  		bcopy((caddr_t)&(((struct sockaddr_ipx *)dst)->sipx_addr.x_host),
 		    (caddr_t)edst, sizeof (edst));
-
-		for(ia = ifp->if_addrhead.tqh_first; ia != 0;
-		    ia = ia->ifa_link.tqe_next) {
-			if(ia->ifa_addr->sa_family == AF_IPX &&
-			   !bcmp((caddr_t)edst,
-				 (caddr_t)&((struct ipx_ifaddr *)ia)->ia_addr.sipx_addr.x_host,
-				 sizeof(edst)) )
-				return (looutput(ifp, m, dst, rt));
-		}
-
-		/* If broadcasting on a simplex interface, loopback a copy */
-		if ((m->m_flags & M_BCAST) && (ifp->if_flags & IFF_SIMPLEX))
-			mcopy = m_copy(m, 0, (int)M_COPYALL);
 		break;
-		}
 #endif
 #ifdef NETATALK
 	case AF_APPLETALK: {
 	    struct at_ifaddr *aa;
-            if (!aarpresolve(ac, m, (struct sockaddr_at *)dst, edst)) {
-#ifdef NETATALKDEBUG
-                extern char *prsockaddr(struct sockaddr *);
-                printf("aarpresolv: failed for %s\n", prsockaddr(dst));
-#endif
+            if (!aarpresolve(ac, m, (struct sockaddr_at *)dst, edst))
                 return (0);
-            }
 	    /*
 	     * ifaddr is the first thing in at_ifaddr
 	     */
@@ -261,11 +235,6 @@ fddi_output(ifp, m0, dst, rt0)
 		type = htons(ETHERTYPE_NS);
  		bcopy((caddr_t)&(((struct sockaddr_ns *)dst)->sns_addr.x_host),
 		    (caddr_t)edst, sizeof (edst));
-		if (!bcmp((caddr_t)edst, (caddr_t)&ns_thishost, sizeof(edst)))
-			return (looutput(ifp, m, dst, rt));
-		/* If broadcasting on a simplex interface, loopback a copy */
-		if ((m->m_flags & M_BCAST) && (ifp->if_flags & IFF_SIMPLEX))
-			mcopy = m_copy(m, 0, (int)M_COPYALL);
 		break;
 #endif
 #ifdef	ISO
@@ -284,17 +253,6 @@ fddi_output(ifp, m0, dst, rt0)
 		/* If broadcasting on a simplex interface, loopback a copy */
 		if (*edst & 1)
 			m->m_flags |= (M_BCAST|M_MCAST);
-		if ((m->m_flags & M_BCAST) && (ifp->if_flags & IFF_SIMPLEX) &&
-		    (mcopy = m_copy(m, 0, (int)M_COPYALL))) {
-			M_PREPEND(mcopy, sizeof (*fh), M_DONTWAIT);
-			if (mcopy) {
-				fh = mtod(mcopy, struct fddi_header *);
-				bcopy((caddr_t)edst,
-				      (caddr_t)fh->fddi_dhost, sizeof (edst));
-				bcopy((caddr_t)ac->ac_enaddr,
-				      (caddr_t)fh->fddi_shost, sizeof (edst));
-			}
-		}
 		M_PREPEND(m, 3, M_DONTWAIT);
 		if (m == NULL)
 			return (0);
@@ -320,18 +278,8 @@ fddi_output(ifp, m0, dst, rt0)
 		if (sdl && sdl->sdl_family != AF_LINK && sdl->sdl_alen <= 0)
 			goto bad; /* Not a link interface ? Funny ... */
 		bcopy(LLADDR(sdl), (char *)edst, sizeof(edst));
-		if ((ifp->if_flags & IFF_SIMPLEX) && (*edst & 1) &&
-		    (mcopy = m_copy(m, 0, (int)M_COPYALL))) {
-			M_PREPEND(mcopy, sizeof (*fh), M_DONTWAIT);
-			if (mcopy) {
-				fh = mtod(mcopy, struct fddi_header *);
-				bcopy((caddr_t)edst,
-				      (caddr_t)fh->fddi_dhost, sizeof (edst));
-				bcopy((caddr_t)ac->ac_enaddr,
-				      (caddr_t)fh->fddi_shost, sizeof (edst));
-				fh->fddi_fc = FDDIFC_LLC_ASYNC|FDDIFC_LLC_PRIO4;
-			}
-		}
+		if (*edst & 1)
+			loop_copy = 1;
 		type = 0;
 #ifdef LLC_DEBUG
 		{
@@ -402,9 +350,6 @@ fddi_output(ifp, m0, dst, rt0)
 		senderr(EAFNOSUPPORT);
 	}
 
-
-	if (mcopy)
-		(void) looutput(ifp, mcopy, dst, rt);
 	if (type != 0) {
 		register struct llc *l;
 		M_PREPEND(m, sizeof (struct llc), M_DONTWAIT);
@@ -417,6 +362,7 @@ fddi_output(ifp, m0, dst, rt0)
 		(void)memcpy((caddr_t) &l->llc_snap.ether_type, (caddr_t) &type,
 			sizeof(u_int16_t));
 	}
+
 	/*
 	 * Add local net header.  If no space in first mbuf,
 	 * allocate another.
@@ -430,6 +376,30 @@ fddi_output(ifp, m0, dst, rt0)
   queue_it:
  	(void)memcpy((caddr_t)fh->fddi_shost, (caddr_t)ac->ac_enaddr,
 	    sizeof(fh->fddi_shost));
+
+	/*
+	 * If a simplex interface, and the packet is being sent to our
+	 * Ethernet address or a broadcast address, loopback a copy.
+	 * XXX To make a simplex device behave exactly like a duplex
+	 * device, we should copy in the case of sending to our own
+	 * ethernet address (thus letting the original actually appear
+	 * on the wire). However, we don't do that here for security
+	 * reasons and compatibility with the original behavior.
+	 */
+	if (ifp->if_flags & IFF_SIMPLEX) {
+		if ((m->m_flags & M_BCAST) || loop_copy) {
+			struct mbuf *n = m_copy(m, 0, (int)M_COPYALL);
+
+			(void) if_simloop(ifp,
+				n, dst, sizeof(struct fddi_header));
+	     	} else if (bcmp(fh->fddi_dhost,
+		    fh->fddi_shost, sizeof(fh->fddi_shost)) == 0) {
+			(void) if_simloop(ifp,
+				m, dst, sizeof(struct fddi_header));
+			return(0);	/* XXX */
+		}
+	}
+
 	s = splimp();
 	/*
 	 * Queue message on interface, and start output if interface