Commit 1a5e13a7 authored by Jukka Rissanen's avatar Jukka Rissanen Committed by Fabio Baltieri
Browse files

net: if: Release the interface lock early when starting IPv4 ACD 

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 ACD
addresses that are to be started when network interface comes up
without iface->lock held.

Signed-off-by: default avatarJukka Rissanen <jukka.rissanen@nordicsemi.no>
parent 196782ed

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
@@ -112,6 +112,9 @@ struct net_if_addr { 
			/** Address conflict detection (ACD) timer. */

			sys_snode_t acd_node;



			/** ACD needed list node */

			sys_snode_t acd_need_node;



			/** ACD timeout value. */

			k_timepoint_t acd_timeout;

subsys/net/ip/net_if.c

+28 −3
Changes for subsys/net/ip/net_if.c: 28 added lines, 3 removed lines.
Original line number Diff line number Diff line
@@ -4310,7 +4310,9 @@ void net_if_ipv4_start_acd(struct net_if *iface, struct net_if_addr *ifaddr) 


void net_if_start_acd(struct net_if *iface)

{

	struct net_if_addr *ifaddr, *next;

	struct net_if_ipv4 *ipv4;

	sys_slist_t acd_needed;

	int ret;



	net_if_lock(iface);
@@ -4332,6 +4334,11 @@ void net_if_start_acd(struct net_if *iface) 


	ipv4->conflict_cnt = 0;



	/* Start ACD for all the addresses that were added earlier when

	 * the interface was down.

	 */

	sys_slist_init(&acd_needed);



	/* Start ACD for all the addresses that were added earlier when

	 * the interface was down.

	 */
@@ -4343,9 +4350,21 @@ void net_if_start_acd(struct net_if *iface) 
			continue;

		}



		net_if_ipv4_start_acd(iface, &ipv4->unicast[i].ipv4);

		sys_slist_prepend(&acd_needed, &ipv4->unicast[i].ipv4.acd_need_node);

	}



	net_if_unlock(iface);



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

	 * to avoid any possible mutex deadlock issues.

	 */

	SYS_SLIST_FOR_EACH_CONTAINER_SAFE(&acd_needed,

					  ifaddr, next, acd_need_node) {

		net_if_ipv4_start_acd(iface, ifaddr);

	}



	return;



out:

	net_if_unlock(iface);

}
@@ -4439,7 +4458,8 @@ struct net_if_addr *net_if_ipv4_addr_add(struct net_if *iface, 


		if (!(l2_flags_get(iface) & NET_L2_POINT_TO_POINT) &&

		    !net_ipv4_is_addr_loopback(addr)) {

			net_if_ipv4_start_acd(iface, ifaddr);

			/* ACD is started after the lock is released. */

			;

		} else {

			ifaddr->addr_state = NET_ADDR_PREFERRED;

		}
@@ -4449,7 +4469,12 @@ struct net_if_addr *net_if_ipv4_addr_add(struct net_if *iface, 
		net_mgmt_event_notify_with_info(NET_EVENT_IPV4_ADDR_ADD, iface,

						&ifaddr->address.in_addr,

						sizeof(struct in_addr));

		goto out;



		net_if_unlock(iface);



		net_if_ipv4_start_acd(iface, ifaddr);



		return ifaddr;

	}



out:

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