ifstated, from mpf@. This daemon listens on the routing socket for

interface link state changes and runs commands when these changes occur.
This is particularly useful with carp(4) interfaces; stay tuned for
additional features and documentation.

ok deraadt@ mpf@

2 files changed, 330 insertions, 0 deletions

diff --git a/usr.sbin/ifstated/Makefile b/usr.sbin/ifstated/Makefile
new file mode 100644
index 00000000000..3633d77d9e4
--- /dev/null
+++ b/usr.sbin/ifstated/Makefile
@@ -0,0 +1,7 @@
+#	$OpenBSD: Makefile,v 1.1 2004/01/23 21:34:30 mcbride Exp $
+
+PROG=	ifstated
+MAN=
+LDADD+=-lutil
+
+.include <bsd.prog.mk>
diff --git a/usr.sbin/ifstated/ifstated.c b/usr.sbin/ifstated/ifstated.c
new file mode 100644
index 00000000000..0dd2fab3241
--- /dev/null
+++ b/usr.sbin/ifstated/ifstated.c
@@ -0,0 +1,323 @@
+/*	$OpenBSD: ifstated.c,v 1.1 2004/01/23 21:34:30 mcbride Exp $	*/
+
+/*
+ * Copyright (c) 2004 Marco Pfatschbacher <mpf@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * ifstated listens to link_state transitions on interfaces
+ * and executes predefined commands.
+ */
+
+#include <sys/types.h>
+#include <sys/time.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+
+#include <net/if.h>
+#include <net/route.h>
+#include <netinet/in.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <err.h>
+#include <util.h>
+#include <unistd.h>
+#include <syslog.h>
+#include <stdarg.h>
+
+
+#define CMD_LENGTH 100
+#define CONF_LINES 50
+
+struct conf_t {
+	u_short dev;			/* if_index  */
+	u_char state;			/* if_link_state */
+	char cmd[CMD_LENGTH];
+} conf_table[CONF_LINES];
+
+char	*state_name[] = { "UNKNOWN", "DOWN", "UP" };
+int	opt_debug = 0;
+int	opt_inhibit = 0; 		/* don't run scripts on startup */
+char 	*configfile = "/etc/ifstated.conf";
+
+#define MAX_IFINDEX 64
+int 	prev_states[MAX_IFINDEX]; 	/* -1 to trigger init */
+
+volatile sig_atomic_t got_sighup;
+
+void	loop(void);
+void	eval_rtmsg(struct rt_msghdr *, int);
+void	scan_table(int, int);
+void	fetch_state(void);
+void	usage(void);
+void	doconfig(const char*);
+void	sighup_handler(int);
+#define LOG(s,a) if (opt_debug) \
+	printf("ifstated: " s , a ); \
+	else \
+	syslog(LOG_DAEMON, s , a);
+
+
+void
+usage(void)
+{
+	fprintf(stderr, "usage: ifstated [-hdi] [-f config]\n");
+	exit(1);
+}
+
+int
+main(int argc, char *argv[])
+{
+	int ch;
+	struct sigaction sact;
+
+	while ((ch = getopt(argc, argv, "hdif:")) != -1) {
+		switch (ch) {
+		case 'h':
+			usage();
+			break;
+		case 'd':
+			opt_debug = 1;
+			break;
+		case 'i':
+			opt_inhibit = 1;
+			break;
+		case 'f':
+			configfile = optarg;
+			break;
+		default:
+			usage();
+		}
+	}
+
+	doconfig(configfile);
+
+	bzero((char *)&sact, sizeof sact);
+	sigemptyset(&sact.sa_mask);
+	sact.sa_flags = 0;
+	/* sact.sa_flags |= SA_RESTART; */
+	sact.sa_handler = sighup_handler;
+	(void) sigaction(SIGHUP, &sact, NULL);
+
+	if (!opt_debug) {
+		daemon(0, 0);
+		setproctitle(NULL);
+	}
+
+	LOG("%s\n", "started");
+
+	loop();
+
+	LOG("%s\n", "dropped out of main loop. exiting");
+	return (0);
+}
+
+void
+doconfig(const char *conf)
+{
+	FILE *fconfig = NULL;
+	char *line = NULL;
+	size_t len, lineno = 0;
+	int device = -1;
+	int state = -1;
+	int nrofstates = sizeof(state_name) / sizeof(char *);
+	int cf_line = 0;
+
+	fconfig = fopen(conf, "r");
+
+	if (fconfig == NULL)
+		errx(1, "could not open config: %s\n", conf);
+
+	bzero(conf_table, sizeof(conf_table));
+	bzero(prev_states, sizeof(prev_states));
+
+	while ((line = fparseln(fconfig, &len, &lineno, 
+	    NULL, FPARSELN_UNESCALL)) != NULL) {
+
+		char statename[20];
+		char devname[IF_NAMESIZE];
+		int i;
+		char *cp;
+		
+#define WS      " \t\n"
+		cp = line;
+
+		cp += strspn(cp, WS);
+		if (cp[0] == '\0') {
+			/* empty line */
+			free(line);
+			continue;
+		}
+
+		if (cf_line >= CONF_LINES)
+			errx(1, "too much lines in config\n");
+
+		/* commands */
+		if (line[0] == ' ' || line[0] == '\t') {
+			cp = line;
+			while (*cp == ' ' || *cp == '\t')
+				cp++;
+
+			if (state == -1)
+				errx(1, "no context for config line: %lu\n",
+				    (u_long) lineno);
+
+			conf_table[cf_line].dev = device;
+			conf_table[cf_line].state = state;
+			snprintf(conf_table[cf_line].cmd, CMD_LENGTH, "%s", cp);
+			/* read state via fetch_state() at startup */
+			prev_states[device] = -1;
+
+			cf_line++;
+			free(line);
+			continue;
+		}
+
+		/* context */
+		state = -1;
+
+		if (sscanf(line, "%[^.].%19[^:]\n", devname, statename) != 2)
+			errx(1, "bad state definition at: %d\n", lineno);
+
+		if ((device = if_nametoindex(devname)) == 0)
+			errx(1, "no such device %s at: %d\n", devname, lineno);
+
+		for (i = nrofstates - 1; i >= 0; i--)
+			if (strncmp(state_name[i], statename, 
+			    strlen(state_name[i])) == 0)
+				state = i;
+
+		if (state == -1)
+			errx(1, "bad state definition at: %d\n", lineno);
+
+		if (device >= MAX_IFINDEX)
+			errx(1, "ifindex exceeded at: %d\n", lineno);
+
+		free(line);
+	}
+	fclose(fconfig);
+}
+
+void
+loop(void)
+{
+	int sockfd;
+	int n;
+	char msg[2048];
+
+	if ((sockfd = socket(PF_ROUTE, SOCK_RAW, 0)) < 0)
+		errx(1, "no routing socket");
+
+	if (!opt_inhibit)
+		fetch_state();
+
+	for (;;) {
+		n = read(sockfd, msg, sizeof(msg)); 
+
+		/* reread config, run commands for current states */
+		if (got_sighup) {
+			got_sighup = 0;
+			LOG("%s\n", "restart");
+			doconfig(configfile);
+			if (!opt_inhibit)
+				fetch_state();
+		}
+
+		eval_rtmsg((struct rt_msghdr *) msg, n);
+	}
+}
+
+void
+sighup_handler(int x)
+{
+	got_sighup = 1;
+}
+
+void
+eval_rtmsg(struct rt_msghdr *rtm, int msglen)
+{
+	struct if_msghdr *ifm;
+
+	/* XXX ignore errors? */
+	if (msglen < sizeof(struct rt_msghdr))
+		return;
+
+	if (rtm->rtm_version != RTM_VERSION)
+		return;
+
+	if (rtm->rtm_type != RTM_IFINFO)
+		return;
+
+	ifm = (struct if_msghdr *)rtm;
+	scan_table(ifm->ifm_index, ifm->ifm_data.ifi_link_state);
+}
+
+
+/*
+ * Scan conf_table for commands to run.
+ * Ignore, if there was no change to the previous state.
+ */
+void
+scan_table(int if_index, int state)
+{
+	int i = 0;
+
+	while (conf_table[i].cmd[0] != '\0') {
+		if (conf_table[i].dev == if_index &&
+		    conf_table[i].state == state &&
+		    if_index <= MAX_IFINDEX &&
+		    prev_states[if_index] != state) {
+
+			LOG("%s\n", conf_table[i].cmd);
+			system(conf_table[i].cmd);
+		}
+		i++;
+	}
+	prev_states[if_index] = state;
+}
+
+/* Fetch the current link states. */
+void
+fetch_state(void)
+{
+	int i;
+	int sock = socket(AF_INET, SOCK_DGRAM, 0);
+	
+	for (i = 0; i < MAX_IFINDEX; i++) {
+		struct ifreq ifr;
+		struct if_data  ifrdat;
+
+		char if_name[IF_NAMESIZE];
+
+		if (prev_states[i] != -1)
+			continue;
+
+		if_indextoname(i, if_name);
+
+		strlcpy(ifr.ifr_name, if_name, sizeof(ifr.ifr_name));
+		ifr.ifr_data = (caddr_t)&ifrdat;
+
+		if (ioctl(sock, SIOCGIFDATA, (caddr_t)&ifr) == -1)
+			continue;
+
+		scan_table(i, ifrdat.ifi_link_state);
+
+	}
+	close(sock);
+}