RFC 3927 2.5 only metions the senders IP, not the targets.

Clarify other comments and fix formatting a little.

diff --git a/arp.c b/arp.c
index 462309057ffcb63c61d8ea10fa3d0d9060934c86..ca49e6a7a5f5afb0e20c70e71b55f222c245c698 100644 (file)
--- a/arp.c
+++ b/arp.c
@@ -1,6 +1,6 @@
 /*
  * dhcpcd - DHCP client daemon
- * Copyright (c) 2006-2013 Roy Marples <roy@marples.name>
+ * Copyright (c) 2006-2014 Roy Marples <roy@marples.name>
  * All rights reserved
 
  * Redistribution and use in source and binary forms, with or without
@@ -94,9 +94,9 @@ arp_failure(struct interface *ifp)
        /* If we failed without a magic cookie then we need to try
         * and defend our IPv4LL address. */
        if ((state->offer != NULL &&
-               state->offer->cookie != htonl(MAGIC_COOKIE)) ||
+           state->offer->cookie != htonl(MAGIC_COOKIE)) ||
            (state->new != NULL &&
-               state->new->cookie != htonl(MAGIC_COOKIE)))
+           state->new->cookie != htonl(MAGIC_COOKIE)))
        {
                ipv4ll_handle_failure(ifp);
                return;
@@ -167,8 +167,8 @@ arp_packet(void *arg)
                if (state->arping_index &&
                    state->arping_index <= opts->arping_len &&
                    (reply_s == opts->arping[state->arping_index - 1] ||
-                       (reply_s == 0 &&
-                           reply_t == opts->arping[state->arping_index - 1])))
+                   (reply_s == 0 &&
+                   reply_t == opts->arping[state->arping_index - 1])))
                {
                        ina.s_addr = reply_s;
                        hwaddr = hwaddr_ntoa((unsigned char *)hw_s,
@@ -185,16 +185,16 @@ arp_packet(void *arg)
                        return;
                }
 
-               /* Check for conflict */
+               /* RFC 2131 3.1.5, Client-server interaction
+                * RFC 3927 2.2.1, Probe Conflict Detection */
                if (state->offer &&
                    (reply_s == state->offer->yiaddr ||
-                       (reply_s == 0 && reply_t == state->offer->yiaddr)))
+                   (reply_s == 0 && reply_t == state->offer->yiaddr)))
                        state->fail.s_addr = state->offer->yiaddr;
 
-               /* Handle IPv4LL conflicts */
+               /* RFC 3927 2.5, Conflict Defense */
                if (IN_LINKLOCAL(htonl(state->addr.s_addr)) &&
-                   (reply_s == state->addr.s_addr ||
-                       (reply_s == 0 && reply_t == state->addr.s_addr)))
+                   reply_s == state->addr.s_addr)
                        state->fail.s_addr = state->addr.s_addr;
 
                if (state->fail.s_addr) {