From 32988844e41ba2dafefd4b0ca819b8c48ecbbb81 Mon Sep 17 00:00:00 2001
From: Renato Botelho <renato@netgate.com>
Date: Thu, 6 Oct 2016 07:51:32 -0300
Subject: Revert "bridge: Fix fragment handling and memory leak"

This reverts commit 7a332daf8ec44bea09dd38a4026773c41caf9758.
---
 sys/net/if_bridge.c | 86 +++++++++++++++++++----------------------------------
 1 file changed, 31 insertions(+), 55 deletions(-)

(limited to 'sys')

diff --git a/sys/net/if_bridge.c b/sys/net/if_bridge.c
index b484191..3b723c1 100644
--- a/sys/net/if_bridge.c
+++ b/sys/net/if_bridge.c
@@ -333,7 +333,7 @@ static int	bridge_ip_checkbasic(struct mbuf **mp);
 #ifdef INET6
 static int	bridge_ip6_checkbasic(struct mbuf **mp);
 #endif /* INET6 */
-static int	bridge_fragment(struct ifnet *, struct mbuf **mp,
+static int	bridge_fragment(struct ifnet *, struct mbuf *,
 		    struct ether_header *, int, struct llc *);
 static void	bridge_linkstate(struct ifnet *ifp);
 static void	bridge_linkcheck(struct bridge_softc *sc);
@@ -1921,7 +1921,6 @@ bridge_enqueue(struct bridge_softc *sc, struct ifnet *dst_ifp, struct mbuf *m)
 			m->m_flags &= ~M_VLANTAG;
 		}
 
-		M_ASSERTPKTHDR(m); /* We shouldn't transmit mbuf without pkthdr */
 		if ((err = dst_ifp->if_transmit(dst_ifp, m))) {
 			m_freem(m0);
 			if_inc_counter(sc->sc_ifp, IFCOUNTER_OERRORS, 1);
@@ -3239,12 +3238,10 @@ bridge_pfil(struct mbuf **mp, struct ifnet *bifp, struct ifnet *ifp, int dir)
 			break;
 
 		/* check if we need to fragment the packet */
-		/* bridge_fragment generates a mbuf chain of packets */
-		/* that already include eth headers */
 		if (V_pfil_member && ifp != NULL && dir == PFIL_OUT) {
 			i = (*mp)->m_pkthdr.len;
 			if (i > ifp->if_mtu) {
-				error = bridge_fragment(ifp, mp, &eh2, snap,
+				error = bridge_fragment(ifp, *mp, &eh2, snap,
 					    &llc1);
 				return (error);
 			}
@@ -3483,77 +3480,56 @@ bad:
 /*
  * bridge_fragment:
  *
- *	Fragment mbuf chain in multiple packets and prepend ethernet header.
+ *	Return a fragmented mbuf chain.
  */
 static int
-bridge_fragment(struct ifnet *ifp, struct mbuf **mp, struct ether_header *eh,
+bridge_fragment(struct ifnet *ifp, struct mbuf *m, struct ether_header *eh,
     int snap, struct llc *llc)
 {
-	struct mbuf *m = *mp, *nextpkt = NULL, *mprev = NULL, *mcur = NULL;
+	struct mbuf *m0;
 	struct ip *ip;
 	int error = -1;
 
 	if (m->m_len < sizeof(struct ip) &&
 	    (m = m_pullup(m, sizeof(struct ip))) == NULL)
-		goto dropit;
+		goto out;
 	ip = mtod(m, struct ip *);
 
 	m->m_pkthdr.csum_flags |= CSUM_IP;
 	error = ip_fragment(ip, &m, ifp->if_mtu, ifp->if_hwassist);
 	if (error)
-		goto dropit;
+		goto out;
 
-	/*
-	 * Walk the chain and re-add the Ethernet header for
-	 * each mbuf packet.
-	 */
-	for (mcur = m; mcur; mcur = mcur->m_nextpkt) {
-		nextpkt = mcur->m_nextpkt;
-		mcur->m_nextpkt = NULL;
-		if (snap) {
-			M_PREPEND(mcur, sizeof(struct llc), M_NOWAIT);
-			if (mcur == NULL) {
+	/* walk the chain and re-add the Ethernet header */
+	for (m0 = m; m0; m0 = m0->m_nextpkt) {
+		if (error == 0) {
+			if (snap) {
+				M_PREPEND(m0, sizeof(struct llc), M_NOWAIT);
+				if (m0 == NULL) {
+					error = ENOBUFS;
+					continue;
+				}
+				bcopy(llc, mtod(m0, caddr_t),
+				    sizeof(struct llc));
+			}
+			M_PREPEND(m0, ETHER_HDR_LEN, M_NOWAIT);
+			if (m0 == NULL) {
 				error = ENOBUFS;
-				if (mprev != NULL)
-					mprev->m_nextpkt = nextpkt;
-				goto dropit;
+				continue;
 			}
-			bcopy(llc, mtod(mcur, caddr_t),sizeof(struct llc));
-		}
-
-		M_PREPEND(mcur, ETHER_HDR_LEN, M_NOWAIT);
-		if (mcur == NULL) {
-			error = ENOBUFS;
-			if (mprev != NULL)
-				mprev->m_nextpkt = nextpkt;
-			goto dropit;
-		}
-		bcopy(eh, mtod(mcur, caddr_t), ETHER_HDR_LEN);
-
-		/*
-		 * The previous two M_PREPEND could have inserted one or two
-		 * mbufs in front so we have to update the previous packet's
-		 * m_nextpkt.
-		 */
-		mcur->m_nextpkt = nextpkt;
-		if (mprev != NULL)
-			mprev->m_nextpkt = mcur;
-		else {
-			/* The first mbuf in the original chain needs to be
-			 * updated. */
-			*mp = mcur;
-		}
-		mprev = mcur;
+			bcopy(eh, mtod(m0, caddr_t), ETHER_HDR_LEN);
+		} else
+			m_freem(m);
 	}
 
-	KMOD_IPSTAT_INC(ips_fragmented);
+	if (error == 0)
+		KMOD_IPSTAT_INC(ips_fragmented);
+
 	return (error);
 
-dropit:
-	for (mcur = *mp; mcur; mcur = m) { /* droping the full packet chain */
-		m = mcur->m_nextpkt;
-		m_freem(mcur);
-	}
+out:
+	if (m != NULL)
+		m_freem(m);
 	return (error);
 }
 
-- 
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