From: Roy Marples <roy@marples.name>
Date: Wed, 9 Jul 2008 06:50:31 +0000 (+0000)
Subject: Add more error checking if the link was taken down or ip addresses removed - if this... 
X-Git-Tag: v4.0.2~228
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d31af5110f301c20859d2572850e4e5b7227e532;p=thirdparty%2Fdhcpcd.git

Add more error checking if the link was taken down or ip addresses removed - if this happens we reset to the init state.
---

diff --git a/client.c b/client.c
index d552f3a9..7c74d80e 100644
--- a/client.c
+++ b/client.c
@@ -585,17 +585,11 @@ do_socket(struct if_state *state, int mode)
 		state->interface->udp_fd = -1;
 	}
 
-	/* We need to bind to a port, otherwise we generate ICMP messages
-	 * that cannot connect the port when we have an address.
-	 * We don't actually use this fd at all, instead using our packet
-	 * filter socket. */
 	if (mode == SOCKET_OPEN &&
 	    state->interface->udp_fd == -1 &&
-	    state->lease.addr.s_addr != 0)
-		if (open_udp_socket(state->interface) == -1) {
-			logger(LOG_ERR, "open_udp_socket: %s", strerror(errno));
-			return -1;
-		}
+	    state->lease.addr.s_addr != 0 &&
+	    open_udp_socket(state->interface) == -1)
+		logger(LOG_ERR, "open_udp_socket: %s", strerror(errno));
 
 	if (mode == SOCKET_OPEN) 
 		if (open_socket(state->interface, ETHERTYPE_IP) == -1) {
@@ -615,12 +609,22 @@ send_message(struct if_state *state, int type, const struct options *options)
 	ssize_t r;
 	struct in_addr from;
 	struct in_addr to;
+	in_addr_t a = 0;
 
 	logger(LOG_DEBUG, "sending %s with xid 0x%x",
 	       get_dhcp_op(type), state->xid);
 	state->messages++;
+	/* If we couldn't open a UDP port for our IP address
+	 * then we cannot renew.
+	 * This could happen if our IP was pulled out from underneath us. */
+	if (state->interface->udp_fd == -1) {
+		a = state->interface->addr.s_addr;
+		state->interface->addr.s_addr = 0;
+	}
 	len = make_message(&dhcp, state->interface, &state->lease, state->xid,
 			   type, options);
+	if (state->interface->udp_fd == -1)
+		state->interface->addr.s_addr = a;
 	from.s_addr = dhcp->ciaddr;
 	if (from.s_addr)
 		to.s_addr = state->lease.server.s_addr;
@@ -634,9 +638,17 @@ send_message(struct if_state *state, int type, const struct options *options)
 		len = make_udp_packet(&udp, (uint8_t *)dhcp, len, from, to);
 		free(dhcp);
 		r = send_raw_packet(state->interface, ETHERTYPE_IP, udp, len);
+		free(udp);
 		if (r == -1)
 			logger(LOG_ERR, "send_raw_packet: %s", strerror(errno));
-		free(udp);
+	}
+
+	/* Failed to send the packet? Return to the init state */
+	if (r == -1) {
+		state->state = STATE_INIT;
+		state->timeout = 0;
+		timerclear(&state->stop);
+		do_socket(state, SOCKET_CLOSED);
 	}
 	return r;
 }
@@ -710,6 +722,24 @@ wait_for_packet(struct if_state *state)
 		if (errno == EINTR)
 			return 0;
 		logger(LOG_ERR, "poll: %s", strerror(errno));
+	} else if (retval != 0) {
+		/* Check if any of the fd's have an error */
+		while (nfds-- > 0) {
+			if (fds[nfds].revents & POLLERR) {
+				logger(LOG_ERR, "error on fd %d", fds[nfds].fd);
+				switch(state->state) {
+				case STATE_INIT: /* FALLTHROUGH */
+				case STATE_DISCOVERING: /* FALLTHROUGH */
+				case STATE_REQUESTING: /* FALLTHROUGH */
+					state->state = STATE_INIT;
+				default:
+					state->state = STATE_RENEW_REQUESTED;
+				}
+				state->timeout = 0;
+				timerclear(&state->stop);
+				return 0;
+			}
+		}
 	}
 	return retval;
 }
@@ -1059,6 +1089,7 @@ handle_timeout(struct if_state *state, const struct options *options)
 	case STATE_INIT:  /* FALLTHROUGH */
 	case STATE_BOUND: /* FALLTHROUGH */
 	case STATE_RENEW_REQUESTED:
+		up_interface(iface->name);
 		do_socket(state, SOCKET_OPEN);
 		state->xid = arc4random();
 		state->messages = 0;
diff --git a/net.c b/net.c
index 74dace15..fa1b7c92 100644
--- a/net.c
+++ b/net.c
@@ -278,6 +278,38 @@ do_interface(const char *ifname,
 	return retval;
 }
 
+int
+up_interface(const char *ifname)
+{
+	int s;
+	struct ifreq ifr;
+	int retval = -1;
+#ifdef __linux__
+	char *p;
+#endif
+
+	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
+		return -1;
+	memset(&ifr, 0, sizeof(ifr));
+	strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
+#ifdef __linux__
+	/* We can only bring the real interface up */
+	if ((p = strchr(ifr.ifr_name, ':')))
+		*p = '\0';
+#endif
+	if (ioctl(s, SIOCGIFFLAGS, &ifr) == 0) {
+		if ((ifr.ifr_flags & IFF_UP))
+			retval = 0;
+		else {
+			ifr.ifr_flags |= IFF_UP;
+			if (ioctl(s, SIOCSIFFLAGS, &ifr) == 0)
+				retval = 0;
+		}
+	}
+	close(s);
+	return retval;
+}
+
 struct interface *
 read_interface(const char *ifname, _unused int metric)
 {
@@ -287,9 +319,6 @@ read_interface(const char *ifname, _unused int metric)
 	unsigned char *hwaddr = NULL;
 	size_t hwlen = 0;
 	sa_family_t family = 0;
-#ifdef __linux__
-	char *p;
-#endif
 
 	memset(&ifr, 0, sizeof(ifr));
 	strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
@@ -342,20 +371,8 @@ read_interface(const char *ifname, _unused int metric)
 			goto eexit;
 	}
 
-	/* Bring the interface up if it's down */
-	strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
-#ifdef __linux__
-	/* We can only bring the real interface up */
-	if ((p = strchr(ifr.ifr_name, ':')))
-		*p = '\0';
-#endif
-	if (ioctl(s, SIOCGIFFLAGS, &ifr) == -1)
+	if (up_interface(ifname) != 0)
 		goto eexit;
-	if (!(ifr.ifr_flags & IFF_UP)) {
-		ifr.ifr_flags |= IFF_UP;
-		if (ioctl(s, SIOCSIFFLAGS, &ifr) != 0)
-			goto eexit;
-	}
 
 	iface = xzalloc(sizeof(*iface));
 	strlcpy(iface->name, ifname, IF_NAMESIZE);
diff --git a/net.h b/net.h
index 0be56cf5..3b030eb2 100644
--- a/net.h
+++ b/net.h
@@ -131,6 +131,7 @@ int do_mtu(const char *, short int);
 int inet_ntocidr(struct in_addr);
 int inet_cidrtoaddr(int, struct in_addr *);
 
+int up_interface(const char *);
 int do_interface(const char *, unsigned char *, size_t *,
 		 struct in_addr *, struct in_addr *, int);
 int if_address(const char *, const struct in_addr *, const struct in_addr *,