From: Roy Marples <roy@marples.name>
Date: Thu, 4 Sep 2008 11:30:11 +0000 (+0000)
Subject: When OS reports new and removed interfaces, dhcpcd sees this and either starts or... 
X-Git-Tag: v5.0.0~302
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=96d0673a2cd58d50f0e4c8e0c60b332a7fff92a8;p=thirdparty%2Fdhcpcd.git

When OS reports new and removed interfaces, dhcpcd sees this and either starts or stops watching them. BSD only, Linux to follow.
---

diff --git a/dhcpcd.c b/dhcpcd.c
index 1afa77a2..306f4d02 100644
--- a/dhcpcd.c
+++ b/dhcpcd.c
@@ -66,6 +66,8 @@ const char copyright[] = "Copyright (c) 2006-2008 Roy Marples";
 
 int master = 0;
 int pidfd = -1;
+static char **ifv = NULL;
+static int ifc = 0;
 static int linkfd = -1;
 static char cffile[PATH_MAX];
 static char pidfile[PATH_MAX] = { '\0' };
@@ -195,6 +197,7 @@ stop_interface(struct interface *iface)
 {
 	struct interface *ifp, *ifl = NULL;
 
+	logger(LOG_ERR, "%s: removing interface", iface->name);
 	drop_config(iface, "STOP");
 	close_sockets(iface);
 	delete_timeout(NULL, iface);
@@ -272,8 +275,6 @@ send_message(struct interface *iface, int type,
 	}
 	free(dhcp);
 	if (r == -1) {
-		logger(LOG_ERR, "%s: removing interface from dhcpcd",
-		       iface->name);
 		stop_interface(iface);
 	} else {
 		if (callback)
@@ -592,44 +593,29 @@ open_sockets(struct interface *iface)
 }
 
 static void
-handle_link(_unused void *arg)
+handle_carrier(struct interface *iface)
 {
-	struct interface *iface;
-	int retval;
-
-	retval = link_changed(linkfd, ifaces);
-	if (retval == -1) {
-		logger(LOG_ERR, "link_changed: %s", strerror(errno));
+	if (!(iface->state->options->options & DHCPCD_LINK))
 		return;
-	}
-	if (retval == 0)
-		return;
-	for (iface = ifaces; iface; iface = iface->next) {
-		if (iface->state->options->options & DHCPCD_LINK) {
-			switch (carrier_status(iface->name)) {
-			case -1:
-				logger(LOG_ERR, "carrier_status: %s",
-				       strerror(errno));
-				break;
-			case 0:
-				if (iface->state->carrier != LINK_DOWN) {
-					iface->state->carrier = LINK_DOWN;
-					logger(LOG_INFO, "%s: carrier lost",
-					       iface->name);
-					close_sockets(iface);
-					delete_timeouts(iface, start_expire, NULL);
-				}
-				break;
-			default:
-				if (iface->state->carrier != LINK_UP) {
-					iface->state->carrier = LINK_UP;
-					logger(LOG_INFO, "%s: carrier acquired",
-					       iface->name);
-					start_interface(iface);
-				}
-				break;
-			}
+	switch (carrier_status(iface->name)) {
+	case -1:
+		logger(LOG_ERR, "carrier_status: %s", strerror(errno));
+		break;
+	case 0:
+		if (iface->state->carrier != LINK_DOWN) {
+			iface->state->carrier = LINK_DOWN;
+			logger(LOG_INFO, "%s: carrier lost", iface->name);
+			close_sockets(iface);
+			delete_timeouts(iface, start_expire, NULL);
+		}
+		break;
+	default:
+		if (iface->state->carrier != LINK_UP) {
+			iface->state->carrier = LINK_UP;
+			logger(LOG_INFO, "%s: carrier acquired", iface->name);
+			start_interface(iface);
 		}
+		break;
 	}
 }
 
@@ -785,6 +771,43 @@ init_state(struct interface *iface, int argc, char **argv)
 		start_interface(iface);
 }
 
+static void
+handle_new_interface(const char *name)
+{
+	struct interface *ifs, *ifp;
+	const char * const argv[] = { "dhcpcd", name };
+	int i;
+
+	/* If running off an interface list, check it's in it. */
+	if (ifc) {
+		for (i = 0; i < ifc; i++)
+			if (strcmp(ifv[i], name) == 0)
+				break;
+		if (i >= ifc)
+			return;
+	}
+
+	if ((ifs = discover_interfaces(2, UNCONST(argv)))) {
+		for (ifp = ifs; ifp; ifp = ifp->next)
+			init_state(ifp, 2, UNCONST(argv));
+		if (ifaces) {
+			ifp = ifaces;
+			while (ifp->next)
+				ifp = ifp->next;
+			ifp->next = ifs;
+		} else
+			ifaces = ifs;
+	}
+}
+
+static void
+handle_link(_unused void *arg)
+{
+	if (manage_link(linkfd, ifaces, handle_carrier,
+			handle_new_interface, stop_interface) == -1)
+		logger(LOG_ERR, "manage_link: %s", strerror(errno));
+}
+
 static void
 handle_signal(_unused void *arg)
 {
@@ -1091,13 +1114,15 @@ main(int argc, char **argv)
 	}
 	free_options(ifo);
 
-	argc -= optind;
-	argv += optind;
-	ifaces = discover_interfaces(argc, argv);
-	argc += optind;
-	argv -= optind;
+	ifc = argc - optind;
+	ifv = argv + optind;
+	ifaces = discover_interfaces(ifc, ifv);
 	for (iface = ifaces; iface; iface = iface->next)
 		init_state(iface, argc, argv);
+	if (!ifaces && ifc == 1) {
+		logger(LOG_ERR, "interface `%s' does not exist", ifv[0]);
+		exit(EXIT_FAILURE);
+	}
 	start_eloop();
 	/* NOTREACHED */
 }
diff --git a/dhcpcd.h b/dhcpcd.h
index ccb7ba2f..608a41d0 100644
--- a/dhcpcd.h
+++ b/dhcpcd.h
@@ -105,6 +105,7 @@ struct interface
 };
 
 extern int pidfd;
+
 int handle_args(int, char **);
 void handle_exit_timeout(void *);
 void send_request(void *);
diff --git a/if-bsd.c b/if-bsd.c
index bad76832..58aa10ff 100644
--- a/if-bsd.c
+++ b/if-bsd.c
@@ -187,23 +187,29 @@ open_link_socket(void)
 	int fd;
 
 	fd = socket(PF_ROUTE, SOCK_RAW, 0);
-	if (fd != -1)
+	if (fd != -1) {
 		set_cloexec(fd);
+		set_nonblock(fd);
+	}
 	return fd;
 }
 
 #define BUFFER_LEN	2048
 int
-link_changed(int fd, const struct interface *ifaces)
+manage_link(int fd, struct interface *ifaces,
+	    void (*if_carrier)(struct interface *),
+	    void (*if_add)(const char *),
+	    void (*if_remove)(struct interface *))
 {
 	char buffer[2048], *p;
 	ssize_t bytes;
 	struct rt_msghdr *rtm;
+	struct if_announcemsghdr *ifa;
 	struct if_msghdr *ifm;
-	const struct interface *iface;
+	struct interface *iface;
 
 	for (;;) {
-		bytes = recv(fd, buffer, BUFFER_LEN, MSG_DONTWAIT);
+		bytes = read(fd, buffer, BUFFER_LEN);
 		if (bytes == -1) {
 			if (errno == EAGAIN)
 				return 0;
@@ -216,12 +222,31 @@ link_changed(int fd, const struct interface *ifaces)
 		     p += ((struct rt_msghdr *)p)->rtm_msglen)
 		{
 			rtm = (struct rt_msghdr *)p;
-			if (rtm->rtm_type != RTM_IFINFO)
-				continue;
-			ifm = (struct if_msghdr *)p;
-			for (iface = ifaces; iface; iface = iface->next)
-				if (ifm->ifm_index == if_nametoindex(iface->name))
-					return 1;
+			switch(rtm->rtm_type) {
+			case RTM_IFANNOUNCE:
+				ifa = (struct if_announcemsghdr *)p;
+				switch(ifa->ifan_what) {
+				case IFAN_ARRIVAL:
+					if_add(ifa->ifan_name);
+					break;
+				case IFAN_DEPARTURE:
+					for (iface = ifaces; iface; iface = iface->next)
+						if (strcmp(ifa->ifan_name, iface->name) == 0) {
+							if_remove(iface);
+							break;
+						}
+					break;
+				}
+				break;
+			case RTM_IFINFO:
+				ifm = (struct if_msghdr *)p;
+				for (iface = ifaces; iface; iface = iface->next)
+					if (ifm->ifm_index == if_nametoindex(iface->name)) {
+						if_carrier(iface);
+						break;
+					}
+				break;
+			}
 		}
 	}
 }
diff --git a/net.h b/net.h
index bf8e4ba5..08e29efc 100644
--- a/net.h
+++ b/net.h
@@ -149,6 +149,9 @@ ssize_t send_raw_packet(const struct interface *, int,
 ssize_t get_raw_packet(struct interface *, int, void *, ssize_t);
 
 int open_link_socket(void);
-int link_changed(int, const struct interface *);
+int manage_link(int, struct interface *,
+		void (*)(struct interface *),
+		void (*)(const char *),
+		void (*)(struct interface *));
 int carrier_status(const char *);
 #endif