Commit c1dacb45 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'nexthop-convert-rtm_-new-del-nexthop-to-per-netns-rtnl' 

Kuniyuki Iwashima says:

====================
nexthop: Convert RTM_{NEW,DEL}NEXTHOP to per-netns RTNL.

Patch 1 - 5 move some validation for RTM_NEWNEXTHOP so that it can be
called without RTNL.

Patch 6 & 7 converts RTM_NEWNEXTHOP and RTM_DELNEXTHOP to per-netns RTNL.

Note that RTM_GETNEXTHOP and RTM_GETNEXTHOPBUCKET are not touched in
this series.

rtm_get_nexthop() can be easily converted to RCU, but rtm_dump_nexthop()
needs more work due to the left-to-right rbtree walk, which looks prone
to node deletion and tree rotation without a retry mechanism.

v1: https://lore.kernel.org/netdev/20250318233240.53946-1-kuniyu@amazon.com/
====================

Link: https://patch.msgid.link/20250319230743.65267-1-kuniyu@amazon.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents b709857e 29c8e323

net/ipv4/nexthop.c

+112 −71
Original line number Diff line number Diff line
@@ -1272,10 +1272,8 @@ 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 +1305,41 @@ 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 +1359,6 @@ 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;

}
@@ -2679,9 +2692,6 @@ 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 +2925,6 @@ 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 +3021,13 @@ 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 +3092,8 @@ 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 +3126,6 @@ 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];
@@ -3188,7 +3169,7 @@ static int rtm_to_nh_config(struct net *net, struct sk_buff *skb, 


		cfg->nh_encap_type = nla_get_u16(tb[NHA_ENCAP_TYPE]);

		err = lwtunnel_valid_encap_type(cfg->nh_encap_type,

						extack, true);

						extack, false);

		if (err < 0)

			goto out;
@@ -3207,22 +3188,76 @@ static int rtm_to_nh_config(struct net *net, struct sk_buff *skb, 
	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) {

	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;

}
@@ -3279,13 +3314,17 @@ static int rtm_del_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh, 
	if (err)

		return err;



	nh = nexthop_find_by_id(net, id);

	if (!nh)

		return -ENOENT;

	rtnl_net_lock(net);



	nh = nexthop_find_by_id(net, id);

	if (nh)

		remove_nexthop(net, nh, &nlinfo);

	else

		err = -ENOENT;



	return 0;

	rtnl_net_unlock(net);



	return err;

}



/* rtnl */
@@ -4037,18 +4076,20 @@ static struct pernet_operations nexthop_net_ops = { 
};



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},

};