IPv4LL: Restart ARP probling on address conflict (#340)

* IPv4LL: Restart ARP probling on address conflict

When IPv4LL address conflict is detected, it is failed to restart IPv4LL
since IPv4LL is running. The commit fixes the problem by restarting ARP
probing instead of restarting IPv4LL.

---------

Co-authored-by: Roy Marples <roy@marples.name>

diff --git a/src/ipv4ll.c b/src/ipv4ll.c
index 89b3dce628405c46fc827a1d0b30d733d1a6cfbf..43974a80bea06f45587acf445a6860bb46ffc187 100644 (file)
--- a/src/ipv4ll.c
+++ b/src/ipv4ll.c
@@ -50,6 +50,8 @@
 #include "sa.h"
 #include "script.h"
 
+static void ipv4ll_start_arp(void *arg);
+
 static const struct in_addr inaddr_llmask = {
        .s_addr = HTONL(LINKLOCAL_MASK)
 };
@@ -275,7 +277,7 @@ ipv4ll_found(struct interface *ifp)
        eloop_timeout_add_sec(ifp->ctx->eloop,
            state->conflicts >= MAX_CONFLICTS ?
            RATE_LIMIT_INTERVAL : PROBE_WAIT,
-           ipv4ll_start, ifp);
+           ipv4ll_start_arp, ifp);
 }
 
 static void
@@ -290,7 +292,7 @@ ipv4ll_defend_failed(struct interface *ifp)
        rt_build(ifp->ctx, AF_INET);
        script_runreason(ifp, "IPV4LL");
        ipv4ll_pickaddr(ifp);
-       ipv4ll_start(ifp);
+       ipv4ll_start_arp(ifp);
 }
 
 #ifndef KERNEL_RFC5227
@@ -323,9 +325,6 @@ ipv4ll_start(void *arg)
        struct ipv4ll_state *state;
        struct ipv4_addr *ia;
        bool repick;
-#ifndef KERNEL_RFC5227
-       struct arp_state *astate;
-#endif
 
        if ((state = IPV4LL_STATE(ifp)) == NULL) {
                ifp->if_data[IF_DATA_IPV4LL] = calloc(1, sizeof(*state));
@@ -407,9 +406,21 @@ ipv4ll_start(void *arg)
                        ipv4ll_pickaddr(ifp);
        }
 
+       ipv4ll_start_arp(ifp);
+}
+
+static void
+ipv4ll_start_arp(void *arg)
+{
+       struct interface *ifp = arg;
 #ifdef KERNEL_RFC5227
        ipv4ll_not_found(ifp);
 #else
+       struct ipv4ll_state *state;
+       struct arp_state *astate;
+
+       state = IPV4LL_STATE(ifp);
+
        ipv4ll_freearp(ifp);
        state->arp = astate = arp_new(ifp, &state->pickedaddr);
        if (state->arp == NULL)