From: Roy Marples <roy@marples.name>
Date: Fri, 26 Feb 2010 15:06:51 +0000 (+0000)
Subject: When trying IPv4LL from a DHCP lease with an IPv4LL address, just
X-Git-Tag: v5.2.0~3
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=716f28888275611c14c492f6f4d2aaab24f59a8f;p=thirdparty%2Fdhcpcd.git

When trying IPv4LL from a DHCP lease with an IPv4LL address, just
use the address and nothing else.
---

diff --git a/ipv4ll.c b/ipv4ll.c
index 46b169a5..7a8e585d 100644
--- a/ipv4ll.c
+++ b/ipv4ll.c
@@ -40,8 +40,8 @@
 #include "ipv4ll.h"
 #include "net.h"
 
-static struct dhcp_message*
-make_ipv4ll_lease(uint32_t old_addr)
+static struct dhcp_message *
+make_ipv4ll_lease(uint32_t addr)
 {
 	uint32_t u32;
 	struct dhcp_message *dhcp;
@@ -49,6 +49,7 @@ make_ipv4ll_lease(uint32_t old_addr)
 
 	dhcp = xzalloc(sizeof(*dhcp));
 	/* Put some LL options in */
+	dhcp->yiaddr = addr;
 	p = dhcp->options;
 	*p++ = DHO_SUBNETMASK;
 	*p++ = sizeof(u32);
@@ -62,21 +63,30 @@ make_ipv4ll_lease(uint32_t old_addr)
 	p += sizeof(u32);
 	*p++ = DHO_END;
 
+	return dhcp;
+}
+
+static struct dhcp_message *
+find_ipv4ll_lease(uint32_t old_addr)
+{
+	uint32_t addr;
+
 	for (;;) {
-		dhcp->yiaddr = htonl(LINKLOCAL_ADDR |
+		addr = htonl(LINKLOCAL_ADDR |
 		    (((uint32_t)abs((int)arc4random())
 			% 0xFD00) + 0x0100));
-		if (dhcp->yiaddr != old_addr &&
-		    IN_LINKLOCAL(ntohl(dhcp->yiaddr)))
+		if (addr != old_addr &&
+		    IN_LINKLOCAL(ntohl(addr)))
 			break;
 	}
-	return dhcp;
+	return make_ipv4ll_lease(addr);
 }
 
 void
 start_ipv4ll(void *arg)
 {
 	struct interface *iface = arg;
+	uint32_t addr;
 
 	delete_timeout(NULL, iface);
 	iface->state->probes = 0;
@@ -89,19 +99,23 @@ start_ipv4ll(void *arg)
 		}
 	}
 
+	if (iface->state->offer == NULL)
+		addr = 0;
+	else {
+		addr = iface->state->offer->yiaddr;
+		free(iface->state->offer);
+	}
 	/* We maybe rebooting an IPv4LL address. */
-	if (!iface->state->offer ||
-	    !IN_LINKLOCAL(htonl(iface->state->offer->yiaddr)))
-	{
+	if (!IN_LINKLOCAL(htonl(addr))) {
 		syslog(LOG_INFO, "%s: probing for an IPv4LL address",
 		    iface->name);
-		delete_timeout(NULL, iface);
-		free(iface->state->offer);
-		iface->state->offer = make_ipv4ll_lease(0);
-		iface->state->lease.frominfo = 0;
+		addr = 0;
 	}
-	/* Ensure we don't have a cookie */
-	iface->state->offer->cookie = 0;
+	if (addr == 0)
+		iface->state->offer = find_ipv4ll_lease(addr);
+	else
+		iface->state->offer = make_ipv4ll_lease(addr);
+	iface->state->lease.frominfo = 0;
 	send_arp_probe(iface);
 }