From: Roy Marples <roy@marples.name>
Date: Fri, 15 May 2015 22:05:17 +0000 (+0000)
Subject: Don't send DHCP messages when we don't have a carrier.
X-Git-Tag: v6.9.0~7
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b60200260a02a86944e756e3681f1b5cecea65c3;p=thirdparty%2Fdhcpcd.git

Don't send DHCP messages when we don't have a carrier.
---

diff --git a/dhcp.c b/dhcp.c
index 3fb9ddd3..a8edf3eb 100644
--- a/dhcp.c
+++ b/dhcp.c
@@ -1593,12 +1593,16 @@ send_message(struct interface *ifp, uint8_t type,
 	struct ipv4_addr *ia;
 #endif
 
-	if (!callback)
+	s = -1;
+	if (!callback) {
+		/* No carrier? Don't bother sending the packet. */
+		if (ifp->carrier == LINK_DOWN)
+			return;
 		logger(ifp->ctx, LOG_DEBUG, "%s: sending %s with xid 0x%x",
 		    ifp->name,
 		    ifo->options & DHCPCD_BOOTP ? "BOOTP" : get_dhcp_op(type),
 		    state->xid);
-	else {
+	} else {
 		if (state->interval == 0)
 			state->interval = 4;
 		else {
@@ -1610,6 +1614,10 @@ send_message(struct interface *ifp, uint8_t type,
 		tv.tv_nsec = (suseconds_t)arc4random_uniform(
 		    (DHCP_RAND_MAX - DHCP_RAND_MIN) * NSEC_PER_SEC);
 		timespecnorm(&tv);
+		/* No carrier? Don't bother sending the packet.
+		 * However, we do need to advance the timeout. */
+		if (ifp->carrier == LINK_DOWN)
+			goto fail;
 		logger(ifp->ctx, LOG_DEBUG,
 		    "%s: sending %s (xid 0x%x), next in %0.1f seconds",
 		    ifp->name,
@@ -1635,8 +1643,7 @@ send_message(struct interface *ifp, uint8_t type,
 		if (s == -1 && errno != EADDRINUSE)
 			logger(ifp->ctx, LOG_ERR,
 			    "%s: dhcp_openudp: %m", ifp->name);
-	} else
-		s = -1;
+	}
 
 	/* If we couldn't open a UDP port for our IP address
 	 * then we cannot renew.
diff --git a/dhcp6.c b/dhcp6.c
index b35b02b7..c1b7bfdb 100644
--- a/dhcp6.c
+++ b/dhcp6.c
@@ -1019,6 +1019,9 @@ dhcp6_sendmessage(struct interface *ifp, void (*callback)(void *))
 	const char *broad_uni;
 	const struct in6_addr alldhcp = IN6ADDR_LINKLOCAL_ALLDHCP_INIT;
 
+	if (!callback && ifp->carrier == LINK_DOWN)
+		return 0;
+
 	memset(&dst, 0, sizeof(dst));
 	dst.sin6_family = AF_INET6;
 	dst.sin6_port = htons(DHCP6_SERVER_PORT);
@@ -1106,16 +1109,17 @@ dhcp6_sendmessage(struct interface *ifp, void (*callback)(void *))
 		}
 
 logsend:
-		logger(ifp->ctx, LOG_DEBUG,
-		    "%s: %s %s (xid 0x%02x%02x%02x),"
-		    " next in %0.1f seconds",
-		    ifp->name,
-		    broad_uni,
-		    dhcp6_get_op(state->send->type),
-		    state->send->xid[0],
-		    state->send->xid[1],
-		    state->send->xid[2],
-		    timespec_to_double(&state->RT));
+		if (ifp->carrier != LINK_DOWN)
+			logger(ifp->ctx, LOG_DEBUG,
+			    "%s: %s %s (xid 0x%02x%02x%02x),"
+			    " next in %0.1f seconds",
+			    ifp->name,
+			    broad_uni,
+			    dhcp6_get_op(state->send->type),
+			    state->send->xid[0],
+			    state->send->xid[1],
+			    state->send->xid[2],
+			    timespec_to_double(&state->RT));
 
 		/* Wait the initial delay */
 		if (state->IMD) {
@@ -1126,6 +1130,9 @@ logsend:
 		}
 	}
 
+	if (ifp->carrier == LINK_DOWN)
+		return 0;
+
 	/* Update the elapsed time */
 	dhcp6_updateelapsed(ifp, state->send, state->send_len);
 	if (ifp->options->auth.options & DHCPCD_AUTH_SEND &&