ipv4: Cache learned redirect information in inetpeer.

Note that we do not generate the redirect netevent any longer, because we don't create a new cached route. Instead, once the new neighbour is bound to the cached route, we emit a neigh update event instead. Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: Cache learned redirect information in inetpeer.
Note that we do not generate the redirect netevent any longer, because we don't create a new cached route. Instead, once the new neighbour is bound to the cached route, we emit a neigh update event instead. Signed-off-by: David S. Miller <davem@davemloft.net>
David S. Miller · Eric Lee · Eric Lee · Eric Lee
1 parent 2c8cec5c10
Showing 1 changed file with 42 additions and 94 deletions Side-by-side Diff
net/ipv4/route.c
@@ -1294,13 +1294,8 @@
 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
 		    __be32 saddr, struct net_device *dev)
 {
-	int i, k;
 	struct in_device *in_dev = __in_dev_get_rcu(dev);
-	struct rtable *rth;
-	struct rtable __rcu **rthp;
-	__be32  skeys[2] = { saddr, 0 };
-	int  ikeys[2] = { dev->ifindex, 0 };
-	struct netevent_redirect netevent;
+	struct inet_peer *peer;
 	struct net *net;
  
 	if (!in_dev)
@@ -1312,9 +1307,6 @@
 	    ipv4_is_zeronet(new_gw))
 		goto reject_redirect;
  
-	if (!rt_caching(net))
-		goto reject_redirect;
-
 	if (!IN_DEV_SHARED_MEDIA(in_dev)) {
 		if (!inet_addr_onlink(in_dev, new_gw, old_gw))
 			goto reject_redirect;
  
  
@@ -1325,93 +1317,13 @@
 			goto reject_redirect;
 	}
  
-	for (i = 0; i < 2; i++) {
-		for (k = 0; k < 2; k++) {
-			unsigned hash = rt_hash(daddr, skeys[i], ikeys[k],
-						rt_genid(net));
+	peer = inet_getpeer_v4(daddr, 1);
+	if (peer) {
+		peer->redirect_learned.a4 = new_gw;
  
-			rthp = &rt_hash_table[hash].chain;
+		inet_putpeer(peer);
  
-			while ((rth = rcu_dereference(*rthp)) != NULL) {
-				struct rtable *rt;
-
-				if (rth->fl.fl4_dst != daddr ||
-				    rth->fl.fl4_src != skeys[i] ||
-				    rth->fl.oif != ikeys[k] ||
-				    rt_is_input_route(rth) ||
-				    rt_is_expired(rth) ||
-				    !net_eq(dev_net(rth->dst.dev), net)) {
-					rthp = &rth->dst.rt_next;
-					continue;
-				}
-
-				if (rth->rt_dst != daddr ||
-				    rth->rt_src != saddr ||
-				    rth->dst.error ||
-				    rth->rt_gateway != old_gw ||
-				    rth->dst.dev != dev)
-					break;
-
-				dst_hold(&rth->dst);
-
-				rt = dst_alloc(&ipv4_dst_ops);
-				if (rt == NULL) {
-					ip_rt_put(rth);
-					return;
-				}
-
-				/* Copy all the information. */
-				*rt = *rth;
-				rt->dst.__use		= 1;
-				atomic_set(&rt->dst.__refcnt, 1);
-				rt->dst.child		= NULL;
-				if (rt->dst.dev)
-					dev_hold(rt->dst.dev);
-				rt->dst.obsolete	= -1;
-				rt->dst.lastuse	= jiffies;
-				rt->dst.path		= &rt->dst;
-				rt->dst.neighbour	= NULL;
-				rt->dst.hh		= NULL;
-#ifdef CONFIG_XFRM
-				rt->dst.xfrm		= NULL;
-#endif
-				rt->rt_genid		= rt_genid(net);
-				rt->rt_flags		|= RTCF_REDIRECTED;
-
-				/* Gateway is different ... */
-				rt->rt_gateway		= new_gw;
-
-				/* Redirect received -> path was valid */
-				dst_confirm(&rth->dst);
-
-				if (rt->peer)
-					atomic_inc(&rt->peer->refcnt);
-				if (rt->fi)
-					atomic_inc(&rt->fi->fib_clntref);
-
-				if (arp_bind_neighbour(&rt->dst) ||
-				    !(rt->dst.neighbour->nud_state &
-					    NUD_VALID)) {
-					if (rt->dst.neighbour)
-						neigh_event_send(rt->dst.neighbour, NULL);
-					ip_rt_put(rth);
-					rt_drop(rt);
-					goto do_next;
-				}
-
-				netevent.old = &rth->dst;
-				netevent.new = &rt->dst;
-				call_netevent_notifiers(NETEVENT_REDIRECT,
-							&netevent);
-
-				rt_del(hash, rth);
-				if (!rt_intern_hash(hash, rt, &rt, NULL, rt->fl.oif))
-					ip_rt_put(rt);
-				goto do_next;
-			}
-		do_next:
-			;
-		}
+		atomic_inc(&__rt_peer_genid);
 	}
 	return;
  
@@ -1678,6 +1590,31 @@
 	}
 }
  
+static int check_peer_redir(struct dst_entry *dst, struct inet_peer *peer)
+{
+	struct rtable *rt = (struct rtable *) dst;
+	__be32 orig_gw = rt->rt_gateway;
+
+	dst_confirm(&rt->dst);
+
+	neigh_release(rt->dst.neighbour);
+	rt->dst.neighbour = NULL;
+
+	rt->rt_gateway = peer->redirect_learned.a4;
+	if (arp_bind_neighbour(&rt->dst) ||
+	    !(rt->dst.neighbour->nud_state & NUD_VALID)) {
+		if (rt->dst.neighbour)
+			neigh_event_send(rt->dst.neighbour, NULL);
+		rt->rt_gateway = orig_gw;
+		return -EAGAIN;
+	} else {
+		rt->rt_flags |= RTCF_REDIRECTED;
+		call_netevent_notifiers(NETEVENT_NEIGH_UPDATE,
+					rt->dst.neighbour);
+	}
+	return 0;
+}
+
 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
 {
 	struct rtable *rt = (struct rtable *) dst;
@@ -1694,6 +1631,12 @@
 		if (peer && peer->pmtu_expires)
 			check_peer_pmtu(dst, peer);
  
+		if (peer && peer->redirect_learned.a4 &&
+		    peer->redirect_learned.a4 != rt->rt_gateway) {
+			if (check_peer_redir(dst, peer))
+				return NULL;
+		}
+
 		rt->rt_peer_genid = rt_peer_genid();
 	}
 	return dst;
@@ -1830,6 +1773,11 @@
  
 		if (peer->pmtu_expires)
 			check_peer_pmtu(&rt->dst, peer);
+		if (peer->redirect_learned.a4 &&
+		    peer->redirect_learned.a4 != rt->rt_gateway) {
+			rt->rt_gateway = peer->redirect_learned.a4;
+			rt->rt_flags |= RTCF_REDIRECTED;
+		}
 	} else {
 		if (fi->fib_metrics != (u32 *) dst_default_metrics) {
 			rt->fi = fi;
...	...	@@ -1294,13 +1294,8 @@
1294	1294	void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1295	1295	__be32 saddr, struct net_device *dev)
1296	1296	{
1297		- int i, k;
1298	1297	struct in_device *in_dev = __in_dev_get_rcu(dev);
1299		- struct rtable *rth;
1300		- struct rtable __rcu **rthp;
1301		- __be32 skeys[2] = { saddr, 0 };
1302		- int ikeys[2] = { dev->ifindex, 0 };
1303		- struct netevent_redirect netevent;
	1298	+ struct inet_peer *peer;
1304	1299	struct net *net;
1305	1300
1306	1301	if (!in_dev)
...	...	@@ -1312,9 +1307,6 @@
1312	1307	ipv4_is_zeronet(new_gw))
1313	1308	goto reject_redirect;
1314	1309
1315		- if (!rt_caching(net))
1316		- goto reject_redirect;
1317		-
1318	1310	if (!IN_DEV_SHARED_MEDIA(in_dev)) {
1319	1311	if (!inet_addr_onlink(in_dev, new_gw, old_gw))
1320	1312	goto reject_redirect;
1321	1313
1322	1314
...	...	@@ -1325,93 +1317,13 @@
1325	1317	goto reject_redirect;
1326	1318	}
1327	1319
1328		- for (i = 0; i < 2; i++) {
1329		- for (k = 0; k < 2; k++) {
1330		- unsigned hash = rt_hash(daddr, skeys[i], ikeys[k],
1331		- rt_genid(net));
	1320	+ peer = inet_getpeer_v4(daddr, 1);
	1321	+ if (peer) {
	1322	+ peer->redirect_learned.a4 = new_gw;
1332	1323
1333		- rthp = &rt_hash_table[hash].chain;
	1324	+ inet_putpeer(peer);
1334	1325
1335		- while ((rth = rcu_dereference(*rthp)) != NULL) {
1336		- struct rtable *rt;
1337		-
1338		- if (rth->fl.fl4_dst != daddr \|\|
1339		- rth->fl.fl4_src != skeys[i] \|\|
1340		- rth->fl.oif != ikeys[k] \|\|
1341		- rt_is_input_route(rth) \|\|
1342		- rt_is_expired(rth) \|\|
1343		- !net_eq(dev_net(rth->dst.dev), net)) {
1344		- rthp = &rth->dst.rt_next;
1345		- continue;
1346		- }
1347		-
1348		- if (rth->rt_dst != daddr \|\|
1349		- rth->rt_src != saddr \|\|
1350		- rth->dst.error \|\|
1351		- rth->rt_gateway != old_gw \|\|
1352		- rth->dst.dev != dev)
1353		- break;
1354		-
1355		- dst_hold(&rth->dst);
1356		-
1357		- rt = dst_alloc(&ipv4_dst_ops);
1358		- if (rt == NULL) {
1359		- ip_rt_put(rth);
1360		- return;
1361		- }
1362		-
1363		- /* Copy all the information. */
1364		- rt = rth;
1365		- rt->dst.__use = 1;
1366		- atomic_set(&rt->dst.__refcnt, 1);
1367		- rt->dst.child = NULL;
1368		- if (rt->dst.dev)
1369		- dev_hold(rt->dst.dev);
1370		- rt->dst.obsolete = -1;
1371		- rt->dst.lastuse = jiffies;
1372		- rt->dst.path = &rt->dst;
1373		- rt->dst.neighbour = NULL;
1374		- rt->dst.hh = NULL;
1375		-#ifdef CONFIG_XFRM
1376		- rt->dst.xfrm = NULL;
1377		-#endif
1378		- rt->rt_genid = rt_genid(net);
1379		- rt->rt_flags \|= RTCF_REDIRECTED;
1380		-
1381		- /* Gateway is different ... */
1382		- rt->rt_gateway = new_gw;
1383		-
1384		- /* Redirect received -> path was valid */
1385		- dst_confirm(&rth->dst);
1386		-
1387		- if (rt->peer)
1388		- atomic_inc(&rt->peer->refcnt);
1389		- if (rt->fi)
1390		- atomic_inc(&rt->fi->fib_clntref);
1391		-
1392		- if (arp_bind_neighbour(&rt->dst) \|\|
1393		- !(rt->dst.neighbour->nud_state &
1394		- NUD_VALID)) {
1395		- if (rt->dst.neighbour)
1396		- neigh_event_send(rt->dst.neighbour, NULL);
1397		- ip_rt_put(rth);
1398		- rt_drop(rt);
1399		- goto do_next;
1400		- }
1401		-
1402		- netevent.old = &rth->dst;
1403		- netevent.new = &rt->dst;
1404		- call_netevent_notifiers(NETEVENT_REDIRECT,
1405		- &netevent);
1406		-
1407		- rt_del(hash, rth);
1408		- if (!rt_intern_hash(hash, rt, &rt, NULL, rt->fl.oif))
1409		- ip_rt_put(rt);
1410		- goto do_next;
1411		- }
1412		- do_next:
1413		- ;
1414		- }
	1326	+ atomic_inc(&__rt_peer_genid);
1415	1327	}
1416	1328	return;
1417	1329
...	...	@@ -1678,6 +1590,31 @@
1678	1590	}
1679	1591	}
1680	1592
	1593	+static int check_peer_redir(struct dst_entry dst, struct inet_peer peer)
	1594	+{
	1595	+ struct rtable rt = (struct rtable ) dst;
	1596	+ __be32 orig_gw = rt->rt_gateway;
	1597	+
	1598	+ dst_confirm(&rt->dst);
	1599	+
	1600	+ neigh_release(rt->dst.neighbour);
	1601	+ rt->dst.neighbour = NULL;
	1602	+
	1603	+ rt->rt_gateway = peer->redirect_learned.a4;
	1604	+ if (arp_bind_neighbour(&rt->dst) \|\|
	1605	+ !(rt->dst.neighbour->nud_state & NUD_VALID)) {
	1606	+ if (rt->dst.neighbour)
	1607	+ neigh_event_send(rt->dst.neighbour, NULL);
	1608	+ rt->rt_gateway = orig_gw;
	1609	+ return -EAGAIN;
	1610	+ } else {
	1611	+ rt->rt_flags \|= RTCF_REDIRECTED;
	1612	+ call_netevent_notifiers(NETEVENT_NEIGH_UPDATE,
	1613	+ rt->dst.neighbour);
	1614	+ }
	1615	+ return 0;
	1616	+}
	1617	+
1681	1618	static struct dst_entry ipv4_dst_check(struct dst_entry dst, u32 cookie)
1682	1619	{
1683	1620	struct rtable rt = (struct rtable ) dst;
...	...	@@ -1694,6 +1631,12 @@
1694	1631	if (peer && peer->pmtu_expires)
1695	1632	check_peer_pmtu(dst, peer);
1696	1633
	1634	+ if (peer && peer->redirect_learned.a4 &&
	1635	+ peer->redirect_learned.a4 != rt->rt_gateway) {
	1636	+ if (check_peer_redir(dst, peer))
	1637	+ return NULL;
	1638	+ }
	1639	+
1697	1640	rt->rt_peer_genid = rt_peer_genid();
1698	1641	}
1699	1642	return dst;
...	...	@@ -1830,6 +1773,11 @@
1830	1773
1831	1774	if (peer->pmtu_expires)
1832	1775	check_peer_pmtu(&rt->dst, peer);
	1776	+ if (peer->redirect_learned.a4 &&
	1777	+ peer->redirect_learned.a4 != rt->rt_gateway) {
	1778	+ rt->rt_gateway = peer->redirect_learned.a4;
	1779	+ rt->rt_flags \|= RTCF_REDIRECTED;
	1780	+ }
1833	1781	} else {
1834	1782	if (fi->fib_metrics != (u32 *) dst_default_metrics) {
1835	1783	rt->fi = fi;