- Compile time NO_DNS option to compile without DNS client

  (this means CNAMEs will not be followed to find the true
   host name that needs updating, and no "server" line will
   be given in the DDNS update package)
- Support for Linux 2.4
   * differences in netlink constants
   * IPv6 addresses do not always have lifetime info so use default TTL

Author: vandry

dnsquery.c

@@ -137,6 +137,7 @@ int ttl;
 	return found;
 }
 
+#ifndef NO_DNS
 static int
 res_init_callback(struct dns_qcache *c)
 {
@@ -151,6 +152,7 @@ do_res_init(void)
 	if (!query_item('r', NULL, res_init_callback)) return 0;
 	return 1;
 }
+#endif
 
 static int
 local_hostname_callback(struct dns_qcache *c)
@@ -180,6 +182,7 @@ struct dns_qcache *c;
 	return c->value;
 }
 
+#ifndef NO_DNS
 static int
 domain_length(unsigned char *buf, int startpos, int len, int seed)
 {
@@ -362,15 +365,21 @@ unsigned char buf[4096];
 	if (verbose) fprintf(stderr, "DNS response incomplete (no answer or authority section)");
 	return -1;
 }
+#endif /* NO_DNS */
 
 char *
 canonical_hostname(void)
 {
 char *hostname;
+#ifndef NO_DNS
 struct dns_qcache *c;
 int tries = 8;
+#endif
 
 	if (!(hostname = local_hostname())) return NULL;
+#ifdef NO_DNS
+	return hostname;
+#else
 	if (!do_res_init()) return NULL;
 
 	while (tries-- > 0) {
@@ -381,8 +390,10 @@ int tries = 8;
 
 	fprintf(stderr, "Too many CNAMEs encountered while querying local hostname\n");
 	return NULL;
+#endif
 }
 
+#ifndef NO_DNS
 char *
 soa_mname(char *host)
 {
@@ -398,3 +409,4 @@ struct dns_qcache *c;
 	}
 	return NULL;
 }
+#endif

dnsupdate.c

@@ -20,7 +20,9 @@ static int
 update_with_list(struct ipl *todo, int verbose, char *override_hostname, char **argv)
 {
 char *hostname;
+#ifndef NO_DNS
 char *server;
+#endif
 int hostname_len, n;
 int total_len, written, pid;
 int pipefd[2];
@@ -43,6 +45,7 @@ char ipbuf[64];
 		return 0;
 	}
 
+#ifndef NO_DNS
 	if (!(server = soa_mname(hostname))) {
 		fprintf(stderr, "DNS update: cannot find server to which to send update\n");
 		free(hostname);
@@ -53,10 +56,16 @@ char ipbuf[64];
 		free(hostname);
 		return 0;
 	}
+#endif
 
 	hostname_len = strlen(hostname);
 		/* "server " + host + " 53\n" + blank line at the end */
-	total_len = 7 + strlen(server) + 4 + 1;
+	total_len =
+#ifdef NO_DNS
+		0;
+#else
+		7 + strlen(server) + 4 + 1;
+#endif
 	for (cur = todo; cur; cur = cur->next) {
 			/* "update delete " + host + " " + ttl + " aaaa (ffff:){7}ffff\n" */
 		total_len += 14 + hostname_len + 1 + 12 + 46;
@@ -65,12 +74,18 @@ char ipbuf[64];
 	if (!(buf = malloc(total_len))) {
 		fprintf(stderr, "DNS update: malloc failure\n");
 		free(hostname);
+#ifndef NO_DNS
 		free(server);
+#endif
 		return 0;
 	}
 
+#ifdef NO_DNS
+	p = buf;
+#else
 	sprintf(buf, "server %s 53\n", server);
 	p = buf + strlen(buf);
+#endif
 
 	for (cur = todo; cur; cur = cur->next) {
 		if (cur->ttl == -2) {
@@ -102,7 +117,9 @@ char ipbuf[64];
 		perror("DNS update: pipe");
 		free(buf);
 		free(hostname);
+#ifndef NO_DNS
 		free(server);
+#endif
 		return 0;
 	}
 
@@ -112,7 +129,9 @@ char ipbuf[64];
 		close(pipefd[1]);
 		free(buf);
 		free(hostname);
+#ifndef NO_DNS
 		free(server);
+#endif
 		return 0;
 	}
 
@@ -138,7 +157,9 @@ char ipbuf[64];
 			close(pipefd[1]);
 			free(buf);
 			free(hostname);
+#ifndef NO_DNS
 			free(server);
+#endif
 			return 0;
 		}
 		written += n;
@@ -147,7 +168,9 @@ char ipbuf[64];
 
 	free(buf);
 	free(hostname);
+#ifndef NO_DNS
 	free(server);
+#endif
 
 	for (;;) {
 		while (waitpid(pid, &n, 0) < 0) sleep(1);

watchip.c

@@ -4,6 +4,7 @@
 #include <string.h>
 #include <errno.h>
 #include <sys/socket.h>
+#include <linux/types.h>
 #include <linux/netlink.h>
 #include <linux/rtnetlink.h>
 #include <arpa/inet.h>
@@ -461,10 +462,13 @@ int ttl = -2;
 		}
 	}
 	if (ttl == -2) {
-		if (ifa->ifa_family == AF_INET6) {
-			return 1;	/* no lifetime information -- ignore address */
-		} else {
+		/* no lifetime information -- use default TTL if there is one */
+		if (w->default_ttl >= 0) {
+			/* For IPv4, a default TTL should always be supplied */
 			ttl = w->default_ttl;
+		} else {
+			/* else ignore the address */
+			return 1;
 		}
 	}
 	if (!rta_addr) return 1;
@@ -653,9 +657,30 @@ int rcvbuf = 32768;
 	bindaddr.nl_family = AF_NETLINK;
 	bindaddr.nl_groups = 0;
 
-	if (((w->filter_sense) != 0) && (w->filter)) bindaddr.nl_groups |= 1 << (RTNLGRP_LINK-1);
-	if (w->filter6) bindaddr.nl_groups |= 1 << (RTNLGRP_IPV6_IFADDR-1);
-	if (w->filter4) bindaddr.nl_groups |= 1 << (RTNLGRP_IPV4_IFADDR-1);
+	if (((w->filter_sense) != 0) && (w->filter)) bindaddr.nl_groups |=
+#if defined(RTNLGRP_LINK)
+		1 << (RTNLGRP_LINK-1);
+#elif defined(RTMGRP_LINK)
+		RTMGRP_LINK;
+#else
+#error "Need either RTNLGRP_LINK or RTMGRP_LINK defined"
+#endif
+	if (w->filter6) bindaddr.nl_groups |=
+#if defined(RTNLGRP_IPV6_IFADDR)
+		1 << (RTNLGRP_IPV6_IFADDR-1);
+#elif defined(RTMGRP_IPV6_IFADDR)
+		RTMGRP_IPV6_IFADDR;
+#else
+#error "Need either RTNLGRP_IPV6_IFADDR or RTMGRP_IPV6_IFADDR defined"
+#endif
+	if (w->filter4) bindaddr.nl_groups |=
+#if defined(RTNLGRP_IPV4_IFADDR)
+		1 << (RTNLGRP_IPV4_IFADDR-1);
+#elif defined(RTMGRP_IPV4_IFADDR)
+		RTMGRP_IPV4_IFADDR;
+#else
+#error "Need either RTNLGRP_IPV4_IFADDR or RTMGRP_IPV4_IFADDR defined"
+#endif
 
 	if (bind(w->netlink_socket, (struct sockaddr *)(&bindaddr), sizeof(bindaddr)) < 0) {
 		perror("bind(..RTNLGRP_IPV4_IFADDR and/or RTNLGRP_IPV6_IFADDR..)");