1 files changed, 82 insertions, 31 deletions

diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 02feda73a98e..49884f96232b 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *	Linux INET6 implementation
  *	Forwarding Information Database
@@ -5,11 +6,6 @@
  *	Authors:
  *	Pedro Roque		<roque@di.fc.ul.pt>
  *
- *	This program is free software; you can redistribute it and/or
- *      modify it under the terms of the GNU General Public License
- *      as published by the Free Software Foundation; either version
- *      2 of the License, or (at your option) any later version.
- *
  *	Changes:
  *	Yuji SEKIYA @USAGI:	Support default route on router node;
  *				remove ip6_null_entry from the top of
@@ -320,9 +316,10 @@ struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
 
 	rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, skb, flags);
 	if (rt->dst.error == -EAGAIN) {
-		ip6_rt_put(rt);
+		ip6_rt_put_flags(rt, flags);
 		rt = net->ipv6.ip6_null_entry;
-		dst_hold(&rt->dst);
+		if (!(flags | RT6_LOOKUP_F_DST_NOREF))
+			dst_hold(&rt->dst);
 	}
 
 	return &rt->dst;
@@ -385,6 +382,22 @@ int call_fib6_entry_notifiers(struct net *net,
 	return call_fib6_notifiers(net, event_type, &info.info);
 }
 
+int call_fib6_multipath_entry_notifiers(struct net *net,
+					enum fib_event_type event_type,
+					struct fib6_info *rt,
+					unsigned int nsiblings,
+					struct netlink_ext_ack *extack)
+{
+	struct fib6_entry_notifier_info info = {
+		.info.extack = extack,
+		.rt = rt,
+		.nsiblings = nsiblings,
+	};
+
+	rt->fib6_table->fib_seq++;
+	return call_fib6_notifiers(net, event_type, &info.info);
+}
+
 struct fib6_dump_arg {
 	struct net *net;
 	struct notifier_block *nb;
@@ -451,12 +464,19 @@ static int fib6_dump_node(struct fib6_walker *w)
 	struct fib6_info *rt;
 
 	for_each_fib6_walker_rt(w) {
-		res = rt6_dump_route(rt, w->args);
-		if (res < 0) {
+		res = rt6_dump_route(rt, w->args, w->skip_in_node);
+		if (res >= 0) {
 			/* Frame is full, suspend walking */
 			w->leaf = rt;
+
+			/* We'll restart from this node, so if some routes were
+			 * already dumped, skip them next time.
+			 */
+			w->skip_in_node += res;
+
 			return 1;
 		}
+		w->skip_in_node = 0;
 
 		/* Multipath routes are dumped in one route with the
 		 * RTA_MULTIPATH attribute. Jump 'rt' to point to the
@@ -508,6 +528,7 @@ static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
 	if (cb->args[4] == 0) {
 		w->count = 0;
 		w->skip = 0;
+		w->skip_in_node = 0;
 
 		spin_lock_bh(&table->tb6_lock);
 		res = fib6_walk(net, w);
@@ -523,6 +544,7 @@ static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
 			w->state = FWS_INIT;
 			w->node = w->root;
 			w->skip = w->count;
+			w->skip_in_node = 0;
 		} else
 			w->skip = 0;
 
@@ -540,9 +562,10 @@ static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
 
 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
 {
+	struct rt6_rtnl_dump_arg arg = { .filter.dump_exceptions = true,
+					 .filter.dump_routes = true };
 	const struct nlmsghdr *nlh = cb->nlh;
 	struct net *net = sock_net(skb->sk);
-	struct rt6_rtnl_dump_arg arg = {};
 	unsigned int h, s_h;
 	unsigned int e = 0, s_e;
 	struct fib6_walker *w;
@@ -559,13 +582,10 @@ static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
 	} else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) {
 		struct rtmsg *rtm = nlmsg_data(nlh);
 
-		arg.filter.flags = rtm->rtm_flags & (RTM_F_PREFIX|RTM_F_CLONED);
+		if (rtm->rtm_flags & RTM_F_PREFIX)
+			arg.filter.flags = RTM_F_PREFIX;
 	}
 
-	/* fib entries are never clones */
-	if (arg.filter.flags & RTM_F_CLONED)
-		goto out;
-
 	w = (void *)cb->args[2];
 	if (!w) {
 		/* New dump:
@@ -910,19 +930,42 @@ static void __fib6_drop_pcpu_from(struct fib6_nh *fib6_nh,
 	}
 }
 
+struct fib6_nh_pcpu_arg {
+	struct fib6_info	*from;
+	const struct fib6_table *table;
+};
+
+static int fib6_nh_drop_pcpu_from(struct fib6_nh *nh, void *_arg)
+{
+	struct fib6_nh_pcpu_arg *arg = _arg;
+
+	__fib6_drop_pcpu_from(nh, arg->from, arg->table);
+	return 0;
+}
+
 static void fib6_drop_pcpu_from(struct fib6_info *f6i,
 				const struct fib6_table *table)
 {
-	struct fib6_nh *fib6_nh;
-
 	/* Make sure rt6_make_pcpu_route() wont add other percpu routes
 	 * while we are cleaning them here.
 	 */
 	f6i->fib6_destroying = 1;
 	mb(); /* paired with the cmpxchg() in rt6_make_pcpu_route() */
 
-	fib6_nh = f6i->fib6_nh;
-	__fib6_drop_pcpu_from(fib6_nh, f6i, table);
+	if (f6i->nh) {
+		struct fib6_nh_pcpu_arg arg = {
+			.from = f6i,
+			.table = table
+		};
+
+		nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_drop_pcpu_from,
+					 &arg);
+	} else {
+		struct fib6_nh *fib6_nh;
+
+		fib6_nh = f6i->fib6_nh;
+		__fib6_drop_pcpu_from(fib6_nh, f6i, table);
+	}
 }
 
 static void fib6_purge_rt(struct fib6_info *rt, struct fib6_node *fn,
@@ -1104,11 +1147,13 @@ next_iter:
 add:
 		nlflags |= NLM_F_CREATE;
 
-		err = call_fib6_entry_notifiers(info->nl_net,
-						FIB_EVENT_ENTRY_ADD,
-						rt, extack);
-		if (err)
-			return err;
+		if (!info->skip_notify_kernel) {
+			err = call_fib6_entry_notifiers(info->nl_net,
+							FIB_EVENT_ENTRY_ADD,
+							rt, extack);
+			if (err)
+				return err;
+		}
 
 		rcu_assign_pointer(rt->fib6_next, iter);
 		fib6_info_hold(rt);
@@ -1133,11 +1178,13 @@ add:
 			return -ENOENT;
 		}
 
-		err = call_fib6_entry_notifiers(info->nl_net,
-						FIB_EVENT_ENTRY_REPLACE,
-						rt, extack);
-		if (err)
-			return err;
+		if (!info->skip_notify_kernel) {
+			err = call_fib6_entry_notifiers(info->nl_net,
+							FIB_EVENT_ENTRY_REPLACE,
+							rt, extack);
+			if (err)
+				return err;
+		}
 
 		fib6_info_hold(rt);
 		rcu_assign_pointer(rt->fib6_node, fn);
@@ -1549,7 +1596,8 @@ static struct fib6_node *fib6_locate_1(struct fib6_node *root,
 		if (plen == fn->fn_bit)
 			return fn;
 
-		prev = fn;
+		if (fn->fn_flags & RTN_RTINFO)
+			prev = fn;
 
 next:
 		/*
@@ -1820,9 +1868,11 @@ static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn,
 
 	fib6_purge_rt(rt, fn, net);
 
-	call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, rt, NULL);
+	if (!info->skip_notify_kernel)
+		call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, rt, NULL);
 	if (!info->skip_notify)
 		inet6_rt_notify(RTM_DELROUTE, rt, info, 0);
+
 	fib6_info_release(rt);
 }
 
@@ -2054,6 +2104,7 @@ static void fib6_clean_tree(struct net *net, struct fib6_node *root,
 	c.w.func = fib6_clean_node;
 	c.w.count = 0;
 	c.w.skip = 0;
+	c.w.skip_in_node = 0;
 	c.func = func;
 	c.sernum = sernum;
 	c.arg = arg;