1 files changed, 133 insertions, 83 deletions

diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c
index 09a3d73b45ba..4397e89d3123 100644
--- a/net/ipv4/nexthop.c
+++ b/net/ipv4/nexthop.c
@@ -541,6 +541,7 @@ static struct nexthop *nexthop_alloc(void)
 		INIT_LIST_HEAD(&nh->f6i_list);
 		INIT_LIST_HEAD(&nh->grp_list);
 		INIT_LIST_HEAD(&nh->fdb_list);
+		spin_lock_init(&nh->lock);
 	}
 	return nh;
 }
@@ -1272,10 +1273,8 @@ static int nh_check_attr_group(struct net *net,
 			       u16 nh_grp_type, struct netlink_ext_ack *extack)
 {
 	unsigned int len = nla_len(tb[NHA_GROUP]);
-	u8 nh_family = AF_UNSPEC;
 	struct nexthop_grp *nhg;
 	unsigned int i, j;
-	u8 nhg_fdb = 0;
 
 	if (!len || len & (sizeof(struct nexthop_grp) - 1)) {
 		NL_SET_ERR_MSG(extack,
@@ -1307,10 +1306,41 @@ static int nh_check_attr_group(struct net *net,
 		}
 	}
 
-	if (tb[NHA_FDB])
-		nhg_fdb = 1;
 	nhg = nla_data(tb[NHA_GROUP]);
-	for (i = 0; i < len; ++i) {
+	for (i = NHA_GROUP_TYPE + 1; i < tb_size; ++i) {
+		if (!tb[i])
+			continue;
+		switch (i) {
+		case NHA_HW_STATS_ENABLE:
+		case NHA_FDB:
+			continue;
+		case NHA_RES_GROUP:
+			if (nh_grp_type == NEXTHOP_GRP_TYPE_RES)
+				continue;
+			break;
+		}
+		NL_SET_ERR_MSG(extack,
+			       "No other attributes can be set in nexthop groups");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int nh_check_attr_group_rtnl(struct net *net, struct nlattr *tb[],
+				    struct netlink_ext_ack *extack)
+{
+	u8 nh_family = AF_UNSPEC;
+	struct nexthop_grp *nhg;
+	unsigned int len;
+	unsigned int i;
+	u8 nhg_fdb;
+
+	len = nla_len(tb[NHA_GROUP]) / sizeof(*nhg);
+	nhg = nla_data(tb[NHA_GROUP]);
+	nhg_fdb = !!tb[NHA_FDB];
+
+	for (i = 0; i < len; i++) {
 		struct nexthop *nh;
 		bool is_fdb_nh;
 
@@ -1330,22 +1360,6 @@ static int nh_check_attr_group(struct net *net,
 			return -EINVAL;
 		}
 	}
-	for (i = NHA_GROUP_TYPE + 1; i < tb_size; ++i) {
-		if (!tb[i])
-			continue;
-		switch (i) {
-		case NHA_HW_STATS_ENABLE:
-		case NHA_FDB:
-			continue;
-		case NHA_RES_GROUP:
-			if (nh_grp_type == NEXTHOP_GRP_TYPE_RES)
-				continue;
-			break;
-		}
-		NL_SET_ERR_MSG(extack,
-			       "No other attributes can be set in nexthop groups");
-		return -EINVAL;
-	}
 
 	return 0;
 }
@@ -1542,12 +1556,12 @@ int fib6_check_nexthop(struct nexthop *nh, struct fib6_config *cfg,
 	if (nh->is_group) {
 		struct nh_group *nhg;
 
-		nhg = rtnl_dereference(nh->nh_grp);
+		nhg = rcu_dereference_rtnl(nh->nh_grp);
 		if (nhg->has_v4)
 			goto no_v4_nh;
 		is_fdb_nh = nhg->fdb_nh;
 	} else {
-		nhi = rtnl_dereference(nh->nh_info);
+		nhi = rcu_dereference_rtnl(nh->nh_info);
 		if (nhi->family == AF_INET)
 			goto no_v4_nh;
 		is_fdb_nh = nhi->fdb_nh;
@@ -2105,7 +2119,7 @@ static void remove_nexthop_group(struct nexthop *nh, struct nl_info *nlinfo)
 /* not called for nexthop replace */
 static void __remove_nexthop_fib(struct net *net, struct nexthop *nh)
 {
-	struct fib6_info *f6i, *tmp;
+	struct fib6_info *f6i;
 	bool do_flush = false;
 	struct fib_info *fi;
 
@@ -2116,13 +2130,24 @@ static void __remove_nexthop_fib(struct net *net, struct nexthop *nh)
 	if (do_flush)
 		fib_flush(net);
 
-	/* ip6_del_rt removes the entry from this list hence the _safe */
-	list_for_each_entry_safe(f6i, tmp, &nh->f6i_list, nh_list) {
+	spin_lock_bh(&nh->lock);
+
+	nh->dead = true;
+
+	while (!list_empty(&nh->f6i_list)) {
+		f6i = list_first_entry(&nh->f6i_list, typeof(*f6i), nh_list);
+
 		/* __ip6_del_rt does a release, so do a hold here */
 		fib6_info_hold(f6i);
+
+		spin_unlock_bh(&nh->lock);
 		ipv6_stub->ip6_del_rt(net, f6i,
 				      !READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode));
+
+		spin_lock_bh(&nh->lock);
 	}
+
+	spin_unlock_bh(&nh->lock);
 }
 
 static void __remove_nexthop(struct net *net, struct nexthop *nh,
@@ -2679,9 +2704,6 @@ static struct nexthop *nexthop_create_group(struct net *net,
 	int err;
 	int i;
 
-	if (WARN_ON(!num_nh))
-		return ERR_PTR(-EINVAL);
-
 	nh = nexthop_alloc();
 	if (!nh)
 		return ERR_PTR(-ENOMEM);
@@ -2915,11 +2937,6 @@ static struct nexthop *nexthop_add(struct net *net, struct nh_config *cfg,
 	struct nexthop *nh;
 	int err;
 
-	if (cfg->nlflags & NLM_F_REPLACE && !cfg->nh_id) {
-		NL_SET_ERR_MSG(extack, "Replace requires nexthop id");
-		return ERR_PTR(-EINVAL);
-	}
-
 	if (!cfg->nh_id) {
 		cfg->nh_id = nh_find_unused_id(net);
 		if (!cfg->nh_id) {
@@ -3016,19 +3033,13 @@ static int rtm_to_nh_config_grp_res(struct nlattr *res, struct nh_config *cfg,
 }
 
 static int rtm_to_nh_config(struct net *net, struct sk_buff *skb,
-			    struct nlmsghdr *nlh, struct nh_config *cfg,
+			    struct nlmsghdr *nlh, struct nlattr **tb,
+			    struct nh_config *cfg,
 			    struct netlink_ext_ack *extack)
 {
 	struct nhmsg *nhm = nlmsg_data(nlh);
-	struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_new)];
 	int err;
 
-	err = nlmsg_parse(nlh, sizeof(*nhm), tb,
-			  ARRAY_SIZE(rtm_nh_policy_new) - 1,
-			  rtm_nh_policy_new, extack);
-	if (err < 0)
-		return err;
-
 	err = -EINVAL;
 	if (nhm->resvd || nhm->nh_scope) {
 		NL_SET_ERR_MSG(extack, "Invalid values in ancillary header");
@@ -3093,7 +3104,8 @@ static int rtm_to_nh_config(struct net *net, struct sk_buff *skb,
 			NL_SET_ERR_MSG(extack, "Invalid group type");
 			goto out;
 		}
-		err = nh_check_attr_group(net, tb, ARRAY_SIZE(tb),
+
+		err = nh_check_attr_group(net, tb, ARRAY_SIZE(rtm_nh_policy_new),
 					  cfg->nh_grp_type, extack);
 		if (err)
 			goto out;
@@ -3126,25 +3138,6 @@ static int rtm_to_nh_config(struct net *net, struct sk_buff *skb,
 		goto out;
 	}
 
-	if (!cfg->nh_fdb && tb[NHA_OIF]) {
-		cfg->nh_ifindex = nla_get_u32(tb[NHA_OIF]);
-		if (cfg->nh_ifindex)
-			cfg->dev = __dev_get_by_index(net, cfg->nh_ifindex);
-
-		if (!cfg->dev) {
-			NL_SET_ERR_MSG(extack, "Invalid device index");
-			goto out;
-		} else if (!(cfg->dev->flags & IFF_UP)) {
-			NL_SET_ERR_MSG(extack, "Nexthop device is not up");
-			err = -ENETDOWN;
-			goto out;
-		} else if (!netif_carrier_ok(cfg->dev)) {
-			NL_SET_ERR_MSG(extack, "Carrier for nexthop device is down");
-			err = -ENETDOWN;
-			goto out;
-		}
-	}
-
 	err = -EINVAL;
 	if (tb[NHA_GATEWAY]) {
 		struct nlattr *gwa = tb[NHA_GATEWAY];
@@ -3206,22 +3199,76 @@ out:
 	return err;
 }
 
+static int rtm_to_nh_config_rtnl(struct net *net, struct nlattr **tb,
+				 struct nh_config *cfg,
+				 struct netlink_ext_ack *extack)
+{
+	if (tb[NHA_GROUP])
+		return nh_check_attr_group_rtnl(net, tb, extack);
+
+	if (tb[NHA_OIF]) {
+		cfg->nh_ifindex = nla_get_u32(tb[NHA_OIF]);
+		if (cfg->nh_ifindex)
+			cfg->dev = __dev_get_by_index(net, cfg->nh_ifindex);
+
+		if (!cfg->dev) {
+			NL_SET_ERR_MSG(extack, "Invalid device index");
+			return -EINVAL;
+		}
+
+		if (!(cfg->dev->flags & IFF_UP)) {
+			NL_SET_ERR_MSG(extack, "Nexthop device is not up");
+			return -ENETDOWN;
+		}
+
+		if (!netif_carrier_ok(cfg->dev)) {
+			NL_SET_ERR_MSG(extack, "Carrier for nexthop device is down");
+			return -ENETDOWN;
+		}
+	}
+
+	return 0;
+}
+
 /* rtnl */
 static int rtm_new_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
 			   struct netlink_ext_ack *extack)
 {
+	struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_new)];
 	struct net *net = sock_net(skb->sk);
 	struct nh_config cfg;
 	struct nexthop *nh;
 	int err;
 
-	err = rtm_to_nh_config(net, skb, nlh, &cfg, extack);
-	if (!err) {
-		nh = nexthop_add(net, &cfg, extack);
-		if (IS_ERR(nh))
-			err = PTR_ERR(nh);
+	err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb,
+			  ARRAY_SIZE(rtm_nh_policy_new) - 1,
+			  rtm_nh_policy_new, extack);
+	if (err < 0)
+		goto out;
+
+	err = rtm_to_nh_config(net, skb, nlh, tb, &cfg, extack);
+	if (err)
+		goto out;
+
+	if (cfg.nlflags & NLM_F_REPLACE && !cfg.nh_id) {
+		NL_SET_ERR_MSG(extack, "Replace requires nexthop id");
+		err = -EINVAL;
+		goto out;
 	}
 
+	rtnl_net_lock(net);
+
+	err = rtm_to_nh_config_rtnl(net, tb, &cfg, extack);
+	if (err)
+		goto unlock;
+
+	nh = nexthop_add(net, &cfg, extack);
+	if (IS_ERR(nh))
+		err = PTR_ERR(nh);
+
+unlock:
+	rtnl_net_unlock(net);
+out:
 	return err;
 }
 
@@ -3278,13 +3325,17 @@ static int rtm_del_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
 	if (err)
 		return err;
 
+	rtnl_net_lock(net);
+
 	nh = nexthop_find_by_id(net, id);
-	if (!nh)
-		return -ENOENT;
+	if (nh)
+		remove_nexthop(net, nh, &nlinfo);
+	else
+		err = -ENOENT;
 
-	remove_nexthop(net, nh, &nlinfo);
+	rtnl_net_unlock(net);
 
-	return 0;
+	return err;
 }
 
 /* rtnl */
@@ -4000,14 +4051,11 @@ out:
 }
 EXPORT_SYMBOL(nexthop_res_grp_activity_update);
 
-static void __net_exit nexthop_net_exit_batch_rtnl(struct list_head *net_list,
-						   struct list_head *dev_to_kill)
+static void __net_exit nexthop_net_exit_rtnl(struct net *net,
+					     struct list_head *dev_to_kill)
 {
-	struct net *net;
-
-	ASSERT_RTNL();
-	list_for_each_entry(net, net_list, exit_list)
-		flush_all_nexthops(net);
+	ASSERT_RTNL_NET(net);
+	flush_all_nexthops(net);
 }
 
 static void __net_exit nexthop_net_exit(struct net *net)
@@ -4032,22 +4080,24 @@ static int __net_init nexthop_net_init(struct net *net)
 static struct pernet_operations nexthop_net_ops = {
 	.init = nexthop_net_init,
 	.exit = nexthop_net_exit,
-	.exit_batch_rtnl = nexthop_net_exit_batch_rtnl,
+	.exit_rtnl = nexthop_net_exit_rtnl,
 };
 
 static const struct rtnl_msg_handler nexthop_rtnl_msg_handlers[] __initconst = {
-	{.msgtype = RTM_NEWNEXTHOP, .doit = rtm_new_nexthop},
-	{.msgtype = RTM_DELNEXTHOP, .doit = rtm_del_nexthop},
+	{.msgtype = RTM_NEWNEXTHOP, .doit = rtm_new_nexthop,
+	 .flags = RTNL_FLAG_DOIT_PERNET},
+	{.msgtype = RTM_DELNEXTHOP, .doit = rtm_del_nexthop,
+	 .flags = RTNL_FLAG_DOIT_PERNET},
 	{.msgtype = RTM_GETNEXTHOP, .doit = rtm_get_nexthop,
 	 .dumpit = rtm_dump_nexthop},
 	{.msgtype = RTM_GETNEXTHOPBUCKET, .doit = rtm_get_nexthop_bucket,
 	 .dumpit = rtm_dump_nexthop_bucket},
 	{.protocol = PF_INET, .msgtype = RTM_NEWNEXTHOP,
-	 .doit = rtm_new_nexthop},
+	 .doit = rtm_new_nexthop, .flags = RTNL_FLAG_DOIT_PERNET},
 	{.protocol = PF_INET, .msgtype = RTM_GETNEXTHOP,
 	 .dumpit = rtm_dump_nexthop},
 	{.protocol = PF_INET6, .msgtype = RTM_NEWNEXTHOP,
-	 .doit = rtm_new_nexthop},
+	 .doit = rtm_new_nexthop, .flags = RTNL_FLAG_DOIT_PERNET},
 	{.protocol = PF_INET6, .msgtype = RTM_GETNEXTHOP,
 	 .dumpit = rtm_dump_nexthop},
 };