From: Roy Marples <roy@marples.name>
Date: Tue, 28 Oct 2008 09:25:26 +0000 (+0000)
Subject: Explain why we decline the address in a message.
X-Git-Tag: v4.0.3~2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4816c6bcb94da81caa25dd210a12c3ffa88da005;p=thirdparty%2Fdhcpcd.git

Explain why we decline the address in a message.
---

diff --git a/dhcp.c b/dhcp.c
index 40f09626..0f61e187 100644
--- a/dhcp.c
+++ b/dhcp.c
@@ -52,6 +52,8 @@
 
 #define IPV4R	IPV4 | REQUEST
 
+#define DAD	"Duplicate address detected"
+
 /* Our aggregate option buffer.
  * We ONLY use this when options are split, which for most purposes is
  * practically never. See RFC3396 for details. */
@@ -762,6 +764,7 @@ make_message(struct dhcp_message **message,
 	uint32_t ul;
 	uint16_t sz;
 	const struct dhcp_opt *opt;
+	size_t len;
 
 	dhcp = xzalloc(sizeof (*dhcp));
 	m = (uint8_t *)dhcp;
@@ -793,15 +796,18 @@ make_message(struct dhcp_message **message,
 	case ARPHRD_IEEE1394:
 	case ARPHRD_INFINIBAND:
 		dhcp->hwlen = 0;
-		if (dhcp->ciaddr == 0)
+		if (dhcp->ciaddr == 0 &&
+		    type != DHCP_DECLINE && type != DHCP_RELEASE)
 			dhcp->flags = htons(BROADCAST_FLAG);
 		break;
 	}
 
-	if (up < 0 || up > (time_t)UINT16_MAX)
-		dhcp->secs = htons((uint16_t)UINT16_MAX);
-	else
-		dhcp->secs = htons(up);
+	if (type != DHCP_DECLINE && type != DHCP_RELEASE) {
+		if (up < 0 || up > (time_t)UINT16_MAX)
+			dhcp->secs = htons((uint16_t)UINT16_MAX);
+		else
+			dhcp->secs = htons(up);
+	}
 	dhcp->xid = xid;
 	dhcp->cookie = htonl(MAGIC_COOKIE);
 
@@ -827,6 +833,14 @@ make_message(struct dhcp_message **message,
 		}
 	}
 
+	if (type == DHCP_DECLINE) {
+		*p++ = DHO_MESSAGE;
+		len = strlen(DAD);
+		*p++ = len;
+		memcpy(p, DAD, len);
+		p += len;
+	}
+
 	if (type == DHCP_RELEASE) {
 		if (lease->server.s_addr)
 			PUTADDR(DHO_SERVERID, lease->server);