From: Roy Marples <roy@marples.name>
Date: Mon, 26 Jan 2009 12:00:01 +0000 (+0000)
Subject: We should only send short hostnames as qualfied ones confuse ISC DHCP server. If... 
X-Git-Tag: v5.0.0~101
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9d9af32de8a952e1dd93f38206acea8fb18f48c8;p=thirdparty%2Fdhcpcd.git

We should only send short hostnames as qualfied ones confuse ISC DHCP server. If a FQDN is required, then use that option instead of the hostname.
---

diff --git a/dhcp.c b/dhcp.c
index a1029c93..b157c6f8 100644
--- a/dhcp.c
+++ b/dhcp.c
@@ -766,6 +766,7 @@ make_message(struct dhcp_message **message,
 	uint32_t ul;
 	uint16_t sz;
 	size_t len;
+	const char *hp;
 	const struct dhcp_opt *opt;
 	const struct if_options *ifo = iface->state->options;
 	const struct dhcp_lease *lease = &iface->state->lease;
@@ -889,10 +890,23 @@ 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]) {
 			*p++ = DHO_HOSTNAME;
-			memcpy(p, ifo->hostname, ifo->hostname[0] + 1);
-			p += ifo->hostname[0] + 1;
+			hp = strchr(ifo->hostname, '.');
+			if (hp) {
+				*p++ = hp - ifo->hostname;
+				memcpy(p, ifo->hostname, hp - ifo->hostname);
+				p += hp - ifo->hostname;
+			} else {
+				len = strlen(ifo->hostname);
+				*p++ = len;
+				memcpy(p, ifo->hostname, len);
+				p += len;
+			}
 		}
 		if (ifo->fqdn != FQDN_DISABLE) {
 			/* IETF DHC-FQDN option (81), RFC4702 */
@@ -912,8 +926,8 @@ make_message(struct dhcp_message **message,
 			*p++ = (ifo->fqdn & 0x09) | 0x04;
 			*p++ = 0; /* from server for PTR RR */
 			*p++ = 0; /* from server for A RR if S=1 */
-			ul = encode_rfc1035(ifo->hostname + 1, p,
-					    ifo->hostname[0]);
+			ul = encode_rfc1035(ifo->hostname, p,
+					    strlen(ifo->hostname));
 			*lp += ul;
 			p += ul;
 		}
diff --git a/if-options.c b/if-options.c
index e8eb5186..36dd1a0d 100644
--- a/if-options.c
+++ b/if-options.c
@@ -676,13 +676,12 @@ read_config(const char *file, const char *ifname, const char *ssid)
 	ifo->timeout = DEFAULT_TIMEOUT;
 	ifo->reboot = DEFAULT_REBOOT;
 	ifo->metric = -1;
-	gethostname(ifo->hostname + 1, HOSTNAME_MAX_LEN);
+	gethostname(ifo->hostname, HOSTNAME_MAX_LEN);
 	/* Ensure that the hostname is NULL terminated */
-	ifo->hostname[HOSTNAME_MAX_LEN + 1] = '\0';
-	if (strcmp(ifo->hostname + 1, "(none)") == 0 ||
-	    strcmp(ifo->hostname + 1, "localhost") == 0)
-		ifo->hostname[1] = '\0';
-	*ifo->hostname = strlen(ifo->hostname + 1);
+	ifo->hostname[HOSTNAME_MAX_LEN] = '\0';
+	if (strcmp(ifo->hostname, "(none)") == 0 ||
+	    strcmp(ifo->hostname, "localhost") == 0)
+		ifo->hostname[0] = '\0';
 	strlcpy(ifo->script, SCRIPT, sizeof(ifo->script));
 	ifo->vendorclassid[0] = snprintf((char *)ifo->vendorclassid + 1,
 					     VENDORCLASSID_MAX_LEN,
diff --git a/if-options.h b/if-options.h
index 5a8b8aaf..02f5f2dc 100644
--- a/if-options.h
+++ b/if-options.h
@@ -88,8 +88,8 @@ struct if_options {
 
 	char **environ;
 	char script[PATH_MAX];
-
-	char hostname[HOSTNAME_MAX_LEN + 2];
+	
+	char hostname[HOSTNAME_MAX_LEN + 1]; /* We don't store the lenth */
 	int fqdn;
 	uint8_t vendorclassid[VENDORCLASSID_MAX_LEN + 2];
 	char clientid[CLIENTID_MAX_LEN + 2];