From: Roy Marples <roy@marples.name>
Date: Thu, 4 Sep 2008 14:08:14 +0000 (+0000)
Subject: Enable detection of addition and removal of interfaces on Linux.
X-Git-Tag: v5.0.0~300
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=064dd58ee2542ff28fdc0e6615c434529c6c92a0;p=thirdparty%2Fdhcpcd.git

Enable detection of addition and removal of interfaces on Linux.
---

diff --git a/dhcpcd.c b/dhcpcd.c
index 306f4d02..fdfb1163 100644
--- a/dhcpcd.c
+++ b/dhcpcd.c
@@ -197,7 +197,7 @@ stop_interface(struct interface *iface)
 {
 	struct interface *ifp, *ifl = NULL;
 
-	logger(LOG_ERR, "%s: removing interface", iface->name);
+	logger(LOG_INFO, "%s: removing interface", iface->name);
 	drop_config(iface, "STOP");
 	close_sockets(iface);
 	delete_timeout(NULL, iface);
@@ -593,9 +593,14 @@ open_sockets(struct interface *iface)
 }
 
 static void
-handle_carrier(struct interface *iface)
+handle_carrier(const char *ifname)
 {
-	if (!(iface->state->options->options & DHCPCD_LINK))
+	struct interface *iface;
+
+	for (iface = ifaces; iface; iface = iface->next)
+		if (strcmp(iface->name, ifname) == 0)
+			break;
+	if (!iface || !(iface->state->options->options & DHCPCD_LINK))
 		return;
 	switch (carrier_status(iface->name)) {
 	case -1:
@@ -772,39 +777,59 @@ init_state(struct interface *iface, int argc, char **argv)
 }
 
 static void
-handle_new_interface(const char *name)
+handle_new_interface(const char *ifname)
 {
-	struct interface *ifs, *ifp;
-	const char * const argv[] = { "dhcpcd", name };
+	struct interface *ifs, *ifp, *ifn, *ifl = NULL;
+	const char * const argv[] = { "dhcpcd", ifname };
 	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)
+			if (strcmp(ifv[i], ifname) == 0)
 				break;
 		if (i >= ifc)
 			return;
 	}
 
 	if ((ifs = discover_interfaces(2, UNCONST(argv)))) {
-		for (ifp = ifs; ifp; ifp = ifp->next)
+		for (ifp = ifs; ifp; ifp = ifp->next) {
+			/* Check if we already have the interface */
+			for (ifn = ifaces; ifn; ifn = ifn->next) {
+				if (strcmp(ifn->name, ifp->name) == 0)
+					break;
+				ifl = ifn;
+			}
+			if (ifn)
+				continue;
 			init_state(ifp, 2, UNCONST(argv));
-		if (ifaces) {
-			ifp = ifaces;
-			while (ifp->next)
-				ifp = ifp->next;
-			ifp->next = ifs;
-		} else
-			ifaces = ifs;
+			if (ifl)
+				ifl->next = ifp;
+			else
+				ifaces = ifp;
+		}
 	}
 }
 
+static void
+handle_remove_interface(const char *ifname)
+{
+	struct interface *iface;
+
+	for (iface = ifaces; iface; iface = iface->next)
+		if (strcmp(iface->name, ifname) == 0)
+			break;
+	if (iface && iface->state->options->options & DHCPCD_LINK)
+		stop_interface(iface);
+}
+
 static void
 handle_link(_unused void *arg)
 {
-	if (manage_link(linkfd, ifaces, handle_carrier,
-			handle_new_interface, stop_interface) == -1)
+	if (manage_link(linkfd,
+			handle_carrier,
+			handle_new_interface,
+			handle_remove_interface) == -1)
 		logger(LOG_ERR, "manage_link: %s", strerror(errno));
 }
 
@@ -855,7 +880,7 @@ handle_signal(_unused void *arg)
 int
 handle_args(int argc, char **argv)
 {
-	struct interface *ifs, *ifp, *ifl = NULL;
+	struct interface *ifs, *ifp, *ifl = NULL, *ifn;
 	int do_exit = 0, do_release = 0, do_reboot = 0, opt, oi = 0;
 
 	optind = 0;
@@ -892,6 +917,7 @@ handle_args(int argc, char **argv)
 			if (do_release)
 				send_release(ifp);
 			if (do_exit || do_release) {
+				logger(LOG_INFO, "%s: removing interface", ifp->name);
 				drop_config(ifp, do_release ? "RELEASE" : "STOP");
 				close_sockets(ifp);
 				delete_timeout(NULL, ifp);
@@ -911,15 +937,20 @@ handle_args(int argc, char **argv)
 	if ((ifs = discover_interfaces(argc, argv))) {
 		argc += optind;
 		argv -= optind;
-		for (ifp = ifs; ifp; ifp = ifp->next)
-			init_state(ifp, argc, argv);
-		if (ifaces) {
-			ifp = ifaces;
-			while (ifp->next)
-				ifp = ifp->next;
-			ifp->next = ifs;
-		} else
-			ifaces = ifs;
+		for (ifp = ifs; ifp; ifp = ifp->next) {
+			for (ifn = ifaces; ifn; ifn = ifn->next) {
+				if (strcmp(ifn->name, ifp->name) == 0)
+					break;
+				ifl = ifn;
+			}
+			if (!ifn) {
+				init_state(ifp, argc, argv);
+				if (ifl)
+					ifl->next = ifp;
+				else
+					ifaces = ifp;
+			}
+		}
 	}
 	return 0;
 }
diff --git a/if-bsd.c b/if-bsd.c
index 58aa10ff..53bf2d66 100644
--- a/if-bsd.c
+++ b/if-bsd.c
@@ -196,12 +196,13 @@ open_link_socket(void)
 
 #define BUFFER_LEN	2048
 int
-manage_link(int fd, struct interface *ifaces,
-	    void (*if_carrier)(struct interface *),
+manage_link(int fd,
+	    void (*if_carrier)(const char *),
 	    void (*if_add)(const char *),
-	    void (*if_remove)(struct interface *))
+	    void (*if_remove)(const char *))
 {
 	char buffer[2048], *p;
+	char ifname[IFNAMSIZ + 1];
 	ssize_t bytes;
 	struct rt_msghdr *rtm;
 	struct if_announcemsghdr *ifa;
@@ -230,21 +231,14 @@ manage_link(int fd, struct interface *ifaces,
 					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;
-						}
+					if_remove(ifa->ifan_name);
 					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;
-					}
+				memset(ifname, 0, sizeof(ifname));
+				if (if_indextoname(ifm->ifm_index, ifname))
+					if_carrier(ifname);
 				break;
 			}
 		}
diff --git a/if-linux.c b/if-linux.c
index 695f033e..bece58cc 100644
--- a/if-linux.c
+++ b/if-linux.c
@@ -59,6 +59,10 @@
 
 #define BUFFERLEN 256
 
+static void (*nl_carrier)(const char *) = NULL;
+static void (*nl_add)(const char *) = NULL;
+static void (*nl_remove)(const char *) = NULL;
+
 int
 open_link_socket(void)
 {
@@ -78,8 +82,7 @@ open_link_socket(void)
 
 static int
 get_netlink(int fd, int flags,
-	    int (*callback)(struct nlmsghdr *, const struct interface *),
-	    const struct interface *iface)
+	    int (*callback)(struct nlmsghdr *))
 {
 	char *buffer = NULL;
 	ssize_t bytes;
@@ -102,7 +105,7 @@ get_netlink(int fd, int flags,
 		     NLMSG_OK(nlm, (size_t)bytes);
 		     nlm = NLMSG_NEXT(nlm, bytes))
 		{
-			r = callback(nlm, iface);
+			r = callback(nlm);
 			if (r != 0)
 				goto eexit;
 		}
@@ -114,7 +117,7 @@ eexit:
 }
 
 static int
-err_netlink(struct nlmsghdr *nlm, _unused const struct interface *iface)
+err_netlink(struct nlmsghdr *nlm)
 {
 	struct nlmsgerr *err;
 	int l;
@@ -134,13 +137,12 @@ err_netlink(struct nlmsghdr *nlm, _unused const struct interface *iface)
 }
 
 static int
-link_netlink(struct nlmsghdr *nlm, const struct interface *ifaces)
+link_netlink(struct nlmsghdr *nlm)
 {
 	int len;
 	struct rtattr *rta;
 	struct ifinfomsg *ifi;
 	char ifn[IF_NAMESIZE + 1];
-	const struct interface *iface;
 
 	if (nlm->nlmsg_type != RTM_NEWLINK && nlm->nlmsg_type != RTM_DELLINK)
 		return 0;
@@ -151,7 +153,7 @@ link_netlink(struct nlmsghdr *nlm, const struct interface *ifaces)
 	}
 	ifi = NLMSG_DATA(nlm);
 	if (ifi->ifi_flags & IFF_LOOPBACK)
-		return 0;
+		return 1;
 	rta = (struct rtattr *) ((char *)ifi + NLMSG_ALIGN(sizeof(*ifi)));
 	len = NLMSG_PAYLOAD(nlm, sizeof(*ifi));
 	*ifn = '\0';
@@ -160,8 +162,8 @@ link_netlink(struct nlmsghdr *nlm, const struct interface *ifaces)
 		case IFLA_WIRELESS:
 			/* Ignore wireless messages */
 			if (nlm->nlmsg_type == RTM_NEWLINK &&
-			    ifi->ifi_change  == 0)
-				return 0;
+			    ifi->ifi_change == 0)
+				return 1;
 			break;
 		case IFLA_IFNAME:
 			strlcpy(ifn, RTA_DATA(rta), sizeof(ifn));
@@ -169,19 +171,31 @@ link_netlink(struct nlmsghdr *nlm, const struct interface *ifaces)
 		}
 		rta = RTA_NEXT(rta, len);
 	}
-
-	for (iface = ifaces; iface; iface = iface->next)
-		if (strcmp(iface->name, ifn) == 0)
-			return 1;
-	return 0;
+	if (nlm->nlmsg_type == RTM_NEWLINK) {
+		if (ifi->ifi_change == ~0U) {
+			if (nl_add)
+				nl_add(ifn);
+		} else {
+			if (nl_carrier)
+				nl_carrier(ifn);
+		}
+	} else {
+		if (nl_remove)
+			nl_remove(ifn);
+	}
+	return 1;
 }
 
-manage_link(int fd, struct interface *ifaces,
-	    void (*if_carrier)(struct interface *),
+int
+manage_link(int fd,
+	    void (*if_carrier)(const char *),
 	    void (*if_add)(const char *),
-	    void (*if_remove)(struct interface *))
+	    void (*if_remove)(const char *))
 {
-	return get_netlink(fd, MSG_DONTWAIT, &link_netlink, ifaces);
+	nl_carrier = if_carrier;
+	nl_add = if_add;
+	nl_remove = if_remove;
+	return get_netlink(fd, MSG_DONTWAIT, &link_netlink);
 }
 
 static int
@@ -214,7 +228,7 @@ send_netlink(struct nlmsghdr *hdr)
 	hdr->nlmsg_seq = ++seq;
 
 	if (sendmsg(fd, &msg, 0) != -1)
-		r = get_netlink(fd, 0, &err_netlink, NULL);
+		r = get_netlink(fd, 0, &err_netlink);
 	else
 		r = -1;
 	close(fd);
diff --git a/net.h b/net.h
index 08e29efc..0629302a 100644
--- a/net.h
+++ b/net.h
@@ -149,9 +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 manage_link(int, struct interface *,
-		void (*)(struct interface *),
+int manage_link(int,
 		void (*)(const char *),
-		void (*)(struct interface *));
+		void (*)(const char *),
+		void (*)(const char *));
 int carrier_status(const char *);
 #endif