From: Roy Marples <roy@marples.name>
Date: Mon, 22 Jul 2013 19:05:54 +0000 (+0000)
Subject: Stop sending FQDN by default.
X-Git-Tag: v6.0.4~7
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=2326c6baed39e56964a5f9f96a55f204609411aa;p=thirdparty%2Fdhcpcd.git

Stop sending FQDN by default.
Instead, if sending the hostname in DHCPv4, send a FQDN in DHCPv6.

This allows for a cleaner configuration file and fixes some DDNS problems
with upstream servers.
---

diff --git a/dhcp.c b/dhcp.c
index 669624d1..06ed6111 100644
--- a/dhcp.c
+++ b/dhcp.c
@@ -986,25 +986,10 @@ make_message(struct dhcp_message **message,
 			}
 		}
 
-		/* Regardless of RFC2132, we should always send a hostname
-		 * upto the first dot (the short hostname) as otherwise
-		 * confuses some DHCP servers when updating DNS.
-		 * The FQDN option should be used if a FQDN is required. */
 		if (ifo->hostname[0] == '\0')
 			hostname = get_hostname();
 		else
 			hostname = ifo->hostname;
-		if (ifo->options & DHCPCD_HOSTNAME && hostname) {
-			*p++ = DHO_HOSTNAME;
-			hp = strchr(hostname, '.');
-			if (hp)
-				len = hp - hostname;
-			else
-				len = strlen(hostname);
-			*p++ = len;
-			memcpy(p, hostname, len);
-			p += len;
-		}
 		if (ifo->fqdn != FQDN_DISABLE) {
 			/* IETF DHC-FQDN option (81), RFC4702 */
 			*p++ = DHO_FQDN;
@@ -1031,6 +1016,22 @@ make_message(struct dhcp_message **message,
 				*lp += ul;
 				p += ul;
 			}
+		} else if (ifo->options & DHCPCD_HOSTNAME && hostname) {
+			*p++ = DHO_HOSTNAME;
+			/*
+			 * Regardless of RFC2132, we should always send a
+			 * hostname upto the first dot (the short hostname) as
+			 * a FQDN confuses some DHCP servers when updating DNS.
+			 * The FQDN option should be used if a FQDN is wanted.
+			 */
+			hp = strchr(hostname, '.');
+			if (hp)
+				len = hp - hostname;
+			else
+				len = strlen(hostname);
+			*p++ = len;
+			memcpy(p, hostname, len);
+			p += len;
 		}
 
 		/* vendor is already encoded correctly, so just add it */
diff --git a/dhcp6.c b/dhcp6.c
index 8ae5466f..9e95b279 100644
--- a/dhcp6.c
+++ b/dhcp6.c
@@ -380,6 +380,7 @@ dhcp6_makemessage(struct interface *ifp)
 	uint32_t u32;
 	const struct ipv6_addr *ap;
 	const char *hostname = NULL; /* assignment just to appease GCC*/
+	int fqdn;
 
 	state = D6_STATE(ifp);
 	if (state->send) {
@@ -387,8 +388,22 @@ dhcp6_makemessage(struct interface *ifp)
 		state->send = NULL;
 	}
 
-	/* Work out option size first */
 	ifo = ifp->options;
+	fqdn = ifo->fqdn;
+
+	if (fqdn == FQDN_DISABLE || ifo->options & DHCPCD_HOSTNAME) {
+		/* We're sending the DHCPv4 hostname option, so send FQDN as
+		 * DHCPv6 has no FQDN option and DHCPv4 must not send
+		 * hostname and FQDN according to RFC4702 */
+		if (fqdn == FQDN_DISABLE)
+			fqdn = FQDN_BOTH;
+		if (ifo->hostname[0] == '\0')
+			hostname = get_hostname();
+		else
+			hostname = ifo->hostname;
+	}
+
+	/* Work out option size first */
 	n_options = 0;
 	len = 0;
 	si = NULL;
@@ -405,13 +420,8 @@ dhcp6_makemessage(struct interface *ifp)
 		if (len)
 			len += sizeof(*o);
 
-		if (ifo->fqdn != FQDN_DISABLE) {
-			if (ifo->hostname[0] == '\0')
-				hostname = get_hostname();
-			else
-				hostname = ifo->hostname;
+		if (fqdn != FQDN_DISABLE)
 			len += sizeof(*o) + 1 + encode_rfc1035(hostname, NULL);
-		}
 	}
 
 	len += sizeof(*state->send);
@@ -617,11 +627,11 @@ dhcp6_makemessage(struct interface *ifp)
 	}
 
 	if (state->send->type !=  DHCP6_RELEASE) {
-		if (ifo->fqdn != FQDN_DISABLE) {
+		if (fqdn != FQDN_DISABLE) {
 			o = D6_NEXT_OPTION(o);
 			o->code = htons(D6_OPTION_FQDN);
 			p = D6_OPTION_DATA(o);
-			switch (ifo->fqdn) {
+			switch (fqdn) {
 			case FQDN_BOTH:
 				*p = D6_FQDN_BOTH;
 				break;
@@ -2303,7 +2313,8 @@ dhcp6_start1(void *arg)
 				add_option_mask(ifo->requestmask6,
 				    dhc->dhcp6_opt);
 		}
-		if (ifo->fqdn != FQDN_DISABLE)
+		if (ifo->fqdn != FQDN_DISABLE ||
+		    ifo->options & DHCPCD_HOSTNAME)
 			add_option_mask(ifo->requestmask6, D6_OPTION_FQDN);
 	}
 
diff --git a/dhcpcd.conf b/dhcpcd.conf
index a646e93c..349c6f22 100644
--- a/dhcpcd.conf
+++ b/dhcpcd.conf
@@ -1,15 +1,9 @@
 # A sample configuration for dhcpcd.
 # See dhcpcd.conf(5) for details.
 
-# Inform the DHCPv4 server of our hostname for DDNS.
-# This has been superceded by the FQDN option below, but is included
-# by default for servers which do not understand it.
+# Inform the DHCP server of our hostname for DDNS.
 hostname
 
-# Inform the DHCP server of our hostname for DDNS
-# and/or query for what it should be.
-fqdn
-
 # Use the hardware address of the interface for the Client ID.
 #clientid
 # or
@@ -22,7 +16,7 @@ duid
 option rapid_commit
 
 # A list of options to request from the DHCP server.
-option domain_name_servers, domain_name, domain_search, host_name, fqdn
+option domain_name_servers, domain_name, domain_search, host_name
 option classless_static_routes
 # Most distributions have NTP support.
 option ntp_servers