Add an option to fallback to a profile when DHCP fails.

4 files changed, 35 insertions, 6 deletions

diff --git a/dhcpcd.c b/dhcpcd.c
index b7653883..11107daf 100644
--- a/dhcpcd.c
+++ b/dhcpcd.c
@@ -766,6 +766,17 @@ select_profile(struct interface *iface, const char *profile)
 }
 
 static void
+start_fallback(void *arg)
+{
+	struct interface *iface;
+
+	iface = (struct interface *)arg;
+	select_profile(iface, iface->state->options->fallback);
+	configure_interface1(iface);
+	start_interface(iface);
+}
+
+static void
 configure_interface(struct interface *iface, int argc, char **argv)
 {
 	select_profile(iface, NULL);
@@ -773,12 +784,13 @@ configure_interface(struct interface *iface, int argc, char **argv)
 	configure_interface1(iface);
 }
 
-
 static void
 handle_carrier(const char *ifname)
 {
 	struct interface *iface;
 
+	if (!(options & DHCPCD_LINK))
+		return;
 	for (iface = ifaces; iface; iface = iface->next)
 		if (strcmp(iface->name, ifname) == 0)
 			break;
@@ -823,7 +835,9 @@ start_discover(void *arg)
 	iface->state->xid = arc4random();
 	open_sockets(iface);
 	delete_timeout(NULL, iface);
-	if (ifo->options & DHCPCD_IPV4LL &&
+	if (ifo->fallback)
+		add_timeout_sec(ifo->timeout, start_fallback, iface);
+	else if (ifo->options & DHCPCD_IPV4LL &&
 	    !IN_LINKLOCAL(htonl(iface->addr.s_addr)))
 	{
 		if (IN_LINKLOCAL(htonl(iface->state->fail.s_addr)))
@@ -974,7 +988,10 @@ start_reboot(struct interface *iface)
 	iface->state->xid = arc4random();
 	iface->state->lease.server.s_addr = 0;
 	delete_timeout(NULL, iface);
-	if (ifo->options & DHCPCD_LASTLEASE && iface->state->lease.frominfo)
+	if (ifo->fallback)
+		add_timeout_sec(ifo->reboot, start_fallback, iface);
+	else if (ifo->options & DHCPCD_LASTLEASE &&
+	    iface->state->lease.frominfo)
 		add_timeout_sec(ifo->reboot, start_timeout, iface);
 	else if (!(ifo->options & DHCPCD_INFORM &&
 		options & (DHCPCD_MASTER | DHCPCD_DAEMONISED)))
diff --git a/dhcpcd.conf.5.in b/dhcpcd.conf.5.in
index 51793773..ec58b866 100644
--- a/dhcpcd.conf.5.in
+++ b/dhcpcd.conf.5.in
@@ -22,7 +22,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd March 31, 2009
+.Dd April 18, 2009
 .Dt DHCPCD.CONF 5 SMM
 .Os
 .Sh NAME
@@ -59,7 +59,7 @@ which is a space or comma separated list of patterns passed to
 .Xr fnmatch 3 .
 .It Ic arping Ar address Op address
 .Nm dhcpcd
-will arping each address in order.
+will arping each address in order before attempting DHCP.
 If an address is found, we will select the replying hardware address as the
 profile, otherwise the ip address.
 Example:
@@ -98,9 +98,12 @@ not enabled by default.
 The duid generated will be held in
 .Pa @SYSCONFDIR@/dhcpcd.duid
 and should not be copied to other hosts.
+.It Ic fallback Ar profile
+Fallback to using this profile if DHCP fails.
+This allows you to configure a static profile instead of using ZeroConf.
 .It Ic hostname Ar name
 Sends specified
-.Ar hostname 
+.Ar hostname
 to the DHCP server so it can be registered in DNS. If
 .Ar hostname
 if a FQDN (ie, contains a .) then it will be encoded as such.
diff --git a/if-options.c b/if-options.c
index 8f52d931..81226978 100644
--- a/if-options.c
+++ b/if-options.c
@@ -49,6 +49,7 @@
    valid short options for them */
 #define O_BASE		MAX('z', 'Z') + 1
 #define O_ARPING	O_BASE + 1
+#define O_FALLBACK	O_BASE + 2
 
 const struct option cf_options[] = {
 	{"background",      no_argument,       NULL, 'b'},
@@ -92,6 +93,7 @@ const struct option cf_options[] = {
 	{"blacklist",       required_argument, NULL, 'X'},
 	{"denyinterfaces",  required_argument, NULL, 'Z'},
 	{"arping",          required_argument, NULL, O_ARPING},
+	{"fallback",        required_argument, NULL, O_FALLBACK},
 	{NULL,              0,                 NULL, '\0'}
 };
 
@@ -673,6 +675,10 @@ parse_option(struct if_options *ifo, int opt, const char *arg)
 		    sizeof(in_addr_t) * (ifo->arping_len + 1));
 		ifo->arping[ifo->arping_len++] = addr.s_addr;
 		break;
+	case O_FALLBACK:
+		free(ifo->fallback);
+		ifo->fallback = xstrdup(arg);
+		break;
 	default:
 		return 0;
 	}
@@ -831,7 +837,9 @@ free_options(struct if_options *ifo)
 			free(ifo->config);
 		}
 		free_routes(ifo->routes);
+		free(ifo->arping);
 		free(ifo->blacklist);
+		free(ifo->fallback);
 		free(ifo);
 	}
 }
diff --git a/if-options.h b/if-options.h
index c6fcf882..8fa122ab 100644
--- a/if-options.h
+++ b/if-options.h
@@ -102,6 +102,7 @@ struct if_options {
 	in_addr_t *blacklist;
 	size_t arping_len;
 	in_addr_t *arping;
+	char *fallback;
 };
 
 struct if_options *read_config(const char *,