From: Roy Marples <roy@marples.name>
Date: Thu, 25 Jun 2015 15:36:28 +0000 (+0000)
Subject: Add an free callback to ARP states so that they can notify their parents they
X-Git-Tag: v6.9.1~32
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c477e2458fa2d4e43493f8899c2020a1ea4193e5;p=thirdparty%2Fdhcpcd.git

Add an free callback to ARP states so that they can notify their parents they
are gone to avoid any double frees.
Fixes [5fdd9b8d08].
---

diff --git a/arp.c b/arp.c
index 70dd324a..f4369047 100644
--- a/arp.c
+++ b/arp.c
@@ -98,7 +98,7 @@ void
 arp_report_conflicted(const struct arp_state *astate, const struct arp_msg *amsg)
 {
 
-	if (amsg) {
+	if (amsg != NULL) {
 		char buf[HWADDR_LEN * 3];
 
 		logger(astate->iface->ctx, LOG_ERR,
@@ -362,6 +362,8 @@ arp_free(struct arp_state *astate)
 		eloop_timeout_delete(ifp->ctx->eloop, NULL, astate);
 		state =	ARP_STATE(ifp);
 		TAILQ_REMOVE(&state->arp_states, astate, next);
+		if (astate->free_cb)
+			astate->free_cb(astate);
 		free(astate);
 
 		/* If there are no more ARP states, close the socket. */
diff --git a/arp.h b/arp.h
index ce0e91fd..6eb3808c 100644
--- a/arp.h
+++ b/arp.h
@@ -57,6 +57,7 @@ struct arp_state {
 	void (*probed_cb)(struct arp_state *);
 	void (*announced_cb)(struct arp_state *);
 	void (*conflicted_cb)(struct arp_state *, const struct arp_msg *);
+	void (*free_cb)(struct arp_state *);
 
 	struct in_addr addr;
 	int probes;
diff --git a/ipv4ll.c b/ipv4ll.c
index fee857f6..e18bb5ef 100644
--- a/ipv4ll.c
+++ b/ipv4ll.c
@@ -243,6 +243,16 @@ ipv4ll_conflicted(struct arp_state *astate, const struct arp_msg *amsg)
 		ipv4ll_probe, astate);
 }
 
+static void
+ipv4ll_arpfree(struct arp_state *astate)
+{
+	struct ipv4ll_state *state;
+
+	state = IPV4LL_STATE(astate->iface);
+	if (state->arp == astate)
+		state->arp = NULL;
+}
+
 void
 ipv4ll_start(void *arg)
 {
@@ -289,6 +299,7 @@ ipv4ll_start(void *arg)
 	astate->probed_cb = ipv4ll_probed;
 	astate->announced_cb = ipv4ll_announced;
 	astate->conflicted_cb = ipv4ll_conflicted;
+	astate->free_cb = ipv4ll_arpfree;
 
 	/* Find an existing IPv4LL address and ensure we can work with it. */
 	ia = ipv4_iffindlladdr(ifp);