This set of changes eliminates the use of MT_TAG "pseudo mbufs", replacing

them mostly with packet tags (one case is handled by using an mbuf flag
since the linkage between "caller" and "callee" is direct and there's no
need to incur the overhead of a packet tag).

This is (mostly) work from: sam

Silence from: -arch
Approved by: bms(mentor), sam, rwatson

1 files changed, 18 insertions, 67 deletions

diff --git a/sys/netinet/ip_fastfwd.c b/sys/netinet/ip_fastfwd.c
index 4041712..3db615d 100644
--- a/sys/netinet/ip_fastfwd.c
+++ b/sys/netinet/ip_fastfwd.c
@@ -110,6 +110,7 @@
 #include <machine/in_cksum.h>
 
 #include <netinet/ip_fw.h>
+#include <netinet/ip_divert.h>
 #include <netinet/ip_dummynet.h>
 
 static int ipfastforward_active = 0;
@@ -132,7 +133,7 @@ ip_fastforward(struct mbuf *m)
 	struct ip *tip;
 	struct mbuf *teem = NULL;
 #endif
-	struct mbuf *tag = NULL;
+	struct m_tag *mtag;
 	struct route ro;
 	struct sockaddr_in *dst = NULL;
 	struct in_ifaddr *ia = NULL;
@@ -150,16 +151,6 @@ ip_fastforward(struct mbuf *m)
 	if (!ipfastforward_active || !ipforwarding)
 		return 0;
 
-	/*
-	 * If there is any MT_TAG we fall back to ip_input because we can't
-	 * handle TAGs here. Should never happen as we get directly called
-	 * from the if_output routines.
-	 */
-	if (m->m_type == MT_TAG) {
-		KASSERT(0, ("%s: packet with MT_TAG not expected", __func__));
-		return 0;
-	}
-
 	M_ASSERTVALID(m);
 	M_ASSERTPKTHDR(m);
 
@@ -373,25 +364,13 @@ fallback:
 			/*
 			 * See if this is a fragment
 			 */
-			if (ip->ip_off & (IP_MF | IP_OFFMASK)) {
-				MGETHDR(tag, M_DONTWAIT, MT_TAG);
-				if (tag == NULL)
-					goto drop;
-				tag->m_flags = PACKET_TAG_DIVERT;
-				tag->m_data = (caddr_t)(intptr_t)args.divert_rule;
-				tag->m_next = m;
-				/* XXX: really bloody hack, see ip_input */
-				tag->m_nextpkt = (struct mbuf *)1;
-				m = tag;
-				tag = NULL;
-
+			if (ip->ip_off & (IP_MF | IP_OFFMASK))
 				goto droptoours;
-			}
 			/*
 			 * Tee packet
 			 */
 			if ((ipfw & IP_FW_PORT_TEE_FLAG) != 0)
-				teem = m_dup(m, M_DONTWAIT);
+				teem = divert_clone(m);
 			else
 				teem = m;
 			if (teem == NULL)
@@ -413,7 +392,7 @@ fallback:
 			/*
 			 * Deliver packet to divert input routine
 			 */
-			divert_packet(teem, 0, ipfw & 0xffff, args.divert_rule);
+			divert_packet(teem, 0);
 			/*
 			 * If this was not tee, we are done
 			 */
@@ -560,27 +539,13 @@ passin:
 			/*
 			 * See if this is a fragment
 			 */
-			if (ip->ip_off & (IP_MF | IP_OFFMASK)) {
-				MGETHDR(tag, M_DONTWAIT, MT_TAG);
-				if (tag == NULL) {
-					RTFREE(ro.ro_rt);
-					goto drop;
-				}
-				tag->m_flags = PACKET_TAG_DIVERT;
-				tag->m_data = (caddr_t)(intptr_t)args.divert_rule;
-				tag->m_next = m;
-				/* XXX: really bloody hack, see ip_input */
-				tag->m_nextpkt = (struct mbuf *)1;
-				m = tag;
-				tag = NULL;
-
+			if (ip->ip_off & (IP_MF | IP_OFFMASK))
 				goto droptoours;
-			}
 			/*
 			 * Tee packet
 			 */
 			if ((ipfw & IP_FW_PORT_TEE_FLAG) != 0)
-				teem = m_dup(m, M_DONTWAIT);
+				teem = divert_clone(m);
 			else
 				teem = m;
 			if (teem == NULL)
@@ -602,7 +567,7 @@ passin:
 			/*
 			 * Deliver packet to divert input routine
 			 */
-			divert_packet(teem, 0, ipfw & 0xffff, args.divert_rule);
+			divert_packet(teem, 0);
 			/*
 			 * If this was not tee, we are done
 			 */
@@ -638,38 +603,24 @@ passout:
 			if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr) {
 forwardlocal:
 				if (args.next_hop) {
-					/* XXX leak */
-					MGETHDR(tag, M_DONTWAIT, MT_TAG);
-					if (tag == NULL) {
+					mtag = m_tag_get(PACKET_TAG_IPFORWARD,
+						   sizeof(struct sockaddr_in *),
+						   M_NOWAIT);
+					if (mtag == NULL) {
+						/* XXX statistic */
 						if (ro.ro_rt)
 							RTFREE(ro.ro_rt);
 						goto drop;
 					}
-					tag->m_flags = PACKET_TAG_IPFORWARD;
-					tag->m_data = (caddr_t)args.next_hop;
-					tag->m_next = m;
-					/* XXX: really bloody hack,
-					 * see ip_input */
-					tag->m_nextpkt = (struct mbuf *)1;
-					m = tag;
-					tag = NULL;
+					*(struct sockaddr_in **)(mtag+1) =
+						args.next_hop;
+					m_tag_prepend(m, mtag);
 				}
 #ifdef IPDIVERT
 droptoours:	/* Used for DIVERT */
 #endif
-				MGETHDR(tag, M_DONTWAIT, MT_TAG);
-				if (tag == NULL) {
-					if (ro.ro_rt)
-						RTFREE(ro.ro_rt);
-					goto drop;
-				}
-				tag->m_flags = PACKET_TAG_IPFASTFWD_OURS;
-				tag->m_data = NULL;
-				tag->m_next = m;
-				/* XXX: really bloody hack, see ip_input */
-				tag->m_nextpkt = (struct mbuf *)1;
-				m = tag;
-				tag = NULL;
+				/* NB: ip_input understands this */
+				m->m_flags |= M_FASTFWD_OURS;
 
 				/* ip still points to the real packet */
 				ip->ip_len = htons(ip->ip_len);