Commit 196782ed authored by Jukka Rissanen's avatar Jukka Rissanen Committed by Fabio Baltieri
Browse files

net: if: Release the interface lock early when rejoining mcast groups 

In order to avoid any mutex deadlocks between iface->lock and
TX lock, release the interface lock before calling a function
that will acquire TX lock. See previous commit for similar issue
in RS timer handling. So here we create a separate list of multicast
addresses that are to be rejoined when network interface comes up
and then rejoin the groups without iface->lock held.

Signed-off-by: default avatarJukka Rissanen <jukka.rissanen@nordicsemi.no>
parent 1e88c62b

include/zephyr/net/net_if.h

+3 −0
Changes for include/zephyr/net/net_if.h: 3 added lines, 0 removed lines.
Original line number Diff line number Diff line
@@ -158,6 +158,9 @@ struct net_if_mcast_addr { 
	/** IP address */

	struct net_addr address;



	/** Rejoining multicast groups list node */

	sys_snode_t rejoin_node;



#if defined(CONFIG_NET_IPV4_IGMPV3)

	/** Sources to filter on */

	struct net_addr sources[CONFIG_NET_IF_MCAST_IPV4_SOURCE_COUNT];

subsys/net/ip/net_if.c

+51 −22
Changes for subsys/net/ip/net_if.c: 51 added lines, 22 removed lines.
Original line number Diff line number Diff line
@@ -1641,7 +1641,9 @@ out: 
 */

static void rejoin_ipv6_mcast_groups(struct net_if *iface)

{

	struct net_if_mcast_addr *ifaddr, *next;

	struct net_if_ipv6 *ipv6;

	sys_slist_t rejoin_needed;



	net_if_lock(iface);
@@ -1663,27 +1665,41 @@ static void rejoin_ipv6_mcast_groups(struct net_if *iface) 
		join_mcast_nodes(iface, &ipv6->unicast[i].address.in6_addr);

	}



	sys_slist_init(&rejoin_needed);



	/* Rejoin any mcast address present on the interface, but marked as not joined. */

	ARRAY_FOR_EACH(ipv6->mcast, i) {

		int ret;



		if (!ipv6->mcast[i].is_used ||

		    net_if_ipv6_maddr_is_joined(&ipv6->mcast[i])) {

			continue;

		}



		ret = net_ipv6_mld_join(iface, &ipv6->mcast[i].address.in6_addr);

		sys_slist_prepend(&rejoin_needed, &ipv6->mcast[i].rejoin_node);

	}



	net_if_unlock(iface);



	/* Start DAD for all the addresses without holding the iface lock

	 * to avoid any possible mutex deadlock issues.

	 */

	SYS_SLIST_FOR_EACH_CONTAINER_SAFE(&rejoin_needed,

					  ifaddr, next, rejoin_node) {

		int ret;



		ret = net_ipv6_mld_join(iface, &ifaddr->address.in6_addr);

		if (ret < 0) {

			NET_ERR("Cannot join mcast address %s for %d (%d)",

				net_sprint_ipv6_addr(&ipv6->mcast[i].address.in6_addr),

				net_sprint_ipv6_addr(&ifaddr->address.in6_addr),

				net_if_get_by_iface(iface), ret);

		} else {

			NET_DBG("Rejoined mcast address %s for %d",

				net_sprint_ipv6_addr(&ipv6->mcast[i].address.in6_addr),

				net_sprint_ipv6_addr(&ifaddr->address.in6_addr),

				net_if_get_by_iface(iface));

		}

	}



	return;



out:

	net_if_unlock(iface);

}
@@ -2024,18 +2040,7 @@ struct net_if_addr *net_if_ipv6_addr_add(struct net_if *iface, 
		if (!(l2_flags_get(iface) & NET_L2_POINT_TO_POINT) &&

		    !net_ipv6_is_addr_loopback(addr) &&

		    !net_if_flag_is_set(iface, NET_IF_IPV6_NO_ND)) {

			/* RFC 4862 5.4.2

			 * Before sending a Neighbor Solicitation, an interface

			 * MUST join the all-nodes multicast address and the

			 * solicited-node multicast address of the tentative

			 * address.

			 */

			/* The allnodes multicast group is only joined once as

			 * net_ipv6_mld_join() checks if we have already

			 * joined.

			 */

			join_mcast_nodes(iface,

					 &ipv6->unicast[i].address.in6_addr);

			/* The groups are joined without locks held */

			do_dad = true;

		} else {

			/* If DAD is not done for point-to-point links, then
@@ -2056,6 +2061,18 @@ struct net_if_addr *net_if_ipv6_addr_add(struct net_if *iface, 
	net_if_unlock(iface);



	if (ifaddr != NULL && do_dad) {

		/* RFC 4862 5.4.2

		 * Before sending a Neighbor Solicitation, an interface

		 * MUST join the all-nodes multicast address and the

		 * solicited-node multicast address of the tentative

		 * address.

		 */

		/* The allnodes multicast group is only joined once as

		 * net_ipv6_mld_join() checks if we have already

		 * joined.

		 */

		join_mcast_nodes(iface, &ifaddr->address.in6_addr);



		net_if_ipv6_start_dad(iface, ifaddr);

	}
@@ -4912,7 +4929,9 @@ static void iface_ipv4_start(struct net_if *iface) 
 */

static void rejoin_ipv4_mcast_groups(struct net_if *iface)

{

	struct net_if_mcast_addr *ifaddr, *next;

	struct net_if_ipv4 *ipv4;

	sys_slist_t rejoin_needed;



	net_if_lock(iface);
@@ -4924,27 +4943,37 @@ static void rejoin_ipv4_mcast_groups(struct net_if *iface) 
		goto out;

	}



	sys_slist_init(&rejoin_needed);



	/* Rejoin any mcast address present on the interface, but marked as not joined. */

	ARRAY_FOR_EACH(ipv4->mcast, i) {

		int ret;



		if (!ipv4->mcast[i].is_used ||

		    net_if_ipv4_maddr_is_joined(&ipv4->mcast[i])) {

			continue;

		}



		ret = net_ipv4_igmp_join(iface, &ipv4->mcast[i].address.in_addr, NULL);

		sys_slist_prepend(&rejoin_needed, &ipv4->mcast[i].rejoin_node);

	}



	net_if_unlock(iface);



	SYS_SLIST_FOR_EACH_CONTAINER_SAFE(&rejoin_needed, ifaddr, next, rejoin_node) {

		int ret;



		ret = net_ipv4_igmp_join(iface, &ifaddr->address.in_addr, NULL);

		if (ret < 0) {

			NET_ERR("Cannot join mcast address %s for %d (%d)",

				net_sprint_ipv4_addr(&ipv4->mcast[i].address.in_addr),

				net_sprint_ipv4_addr(&ifaddr->address.in_addr),

				net_if_get_by_iface(iface), ret);

		} else {

			NET_DBG("Rejoined mcast address %s for %d",

				net_sprint_ipv4_addr(&ipv4->mcast[i].address.in_addr),

				net_sprint_ipv4_addr(&ifaddr->address.in_addr),

				net_if_get_by_iface(iface));

		}

	}



	return;



out:

	net_if_unlock(iface);

}

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