NetBSD/usr.sbin/ifwatchd/ifwatchd.c

395 lines
9.2 KiB
C

/* $NetBSD: ifwatchd.c,v 1.5 2002/01/10 20:21:50 martin Exp $ */
/*
* Copyright (c) 2001-2002 Martin Husemann <martin@duskware.de>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. The name of the author may not be used to endorse or promote products
* derived from this software withough specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Define this for special treatment of sys/net/if_spppsubr.c based interfaces.
*/
#define SPPP_IF_SUPPORT
#include <sys/types.h>
#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/queue.h>
#include <net/if.h>
#include <net/if_dl.h>
#ifdef SPPP_IF_SUPPORT
#include <net/if_sppp.h>
#endif
#include <net/route.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <netdb.h>
#include <err.h>
#include <ifaddrs.h>
/* local functions */
static void usage(void);
static void dispatch(void*, size_t);
static void check_addrs(char *cp, int addrs, int is_up);
static void invoke_script(struct sockaddr *sa, struct sockaddr *dst, int is_up, int ifindex);
static void list_interfaces(const char *ifnames);
static void rescan_interfaces(void);
static void free_interfaces(void);
static int find_interface(int index);
static void run_initial_ups(void);
#ifdef SPPP_IF_SUPPORT
static int if_is_connected(const char * ifname);
#else
#define if_is_connected(X) 1
#endif
/* stolen from /sbin/route */
#define ROUNDUP(a) \
((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
#define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))
/* global variables */
static int verbose = 0;
static int inhibit_initial = 0;
static const char *up_script = NULL;
static const char *down_script = NULL;
struct interface_data {
SLIST_ENTRY(interface_data) next;
int index;
char * ifname;
};
SLIST_HEAD(,interface_data) ifs = SLIST_HEAD_INITIALIZER(ifs);
int
main(int argc, char **argv)
{
int c, s, n;
int errs = 0;
char msg[2048], *msgp;
while ((c = getopt(argc, argv, "vhiu:d:")) != -1)
switch (c) {
case 'h':
usage();
return 0;
case 'i':
inhibit_initial = 1;
break;
case 'v':
verbose++;
break;
case 'u':
up_script = optarg;
break;
case 'd':
down_script = optarg;
break;
default:
errs++;
break;
}
if (errs)
usage();
argv += optind;
argc -= optind;
if (argc <= 0)
usage();
if (verbose) {
printf("up_script: %s\ndown_script: %s\n",
up_script, down_script);
printf("verbosity = %d\n", verbose);
}
while (argc > 0) {
list_interfaces(argv[0]);
argv++; argc--;
}
if (!verbose)
daemon(0,0);
if (!inhibit_initial)
run_initial_ups();
s = socket(PF_ROUTE, SOCK_RAW, 0);
if (s < 0) {
perror("open routing socket");
exit(1);
}
for (;;) {
n = read(s, msg, sizeof msg);
msgp = msg;
for (msgp = msg; n > 0; n -= ((struct rt_msghdr*)msgp)->rtm_msglen, msgp += ((struct rt_msghdr*)msgp)->rtm_msglen) {
dispatch(msgp, n);
}
}
close(s);
free_interfaces();
exit(0);
}
static void
usage()
{
fprintf(stderr,
"usage:\n"
"\tifwatchd [-h] [-v] [-u up-script] [-d down-script] ifname(s)\n"
"\twhere:\n"
"\t -h show this help message\n"
"\t -v verbose/debug output, don't run in background\n"
"\t -i no (!) initial run of the up script if the interface\n"
"\t is already up on ifwatchd startup\n"
"\t -u <cmd> specify command to run on interface up event\n"
"\t -d <cmd> specify command to run on interface down event\n");
exit(1);
}
static void
dispatch(void *msg, size_t len)
{
struct rt_msghdr *hd = msg;
struct ifa_msghdr *ifam;
int is_up;
is_up = 0;
switch (hd->rtm_type) {
case RTM_NEWADDR:
is_up = 1;
goto work;
case RTM_DELADDR:
is_up = 0;
goto work;
case RTM_IFANNOUNCE:
rescan_interfaces();
break;
}
if (verbose)
printf("unknown message ignored\n");
return;
work:
ifam = (struct ifa_msghdr *)msg;
check_addrs((char *)(ifam + 1), ifam->ifam_addrs, is_up);
}
static void
check_addrs(cp, addrs, is_up)
char *cp;
int addrs, is_up;
{
struct sockaddr *sa, *ifa = NULL, *brd = NULL;
int ifndx = 0, i;
if (addrs == 0)
return;
for (i = 1; i; i <<= 1) {
if (i & addrs) {
sa = (struct sockaddr *)cp;
if (i == RTA_IFP) {
struct sockaddr_dl * li = (struct sockaddr_dl*)sa;
ifndx = li->sdl_index;
if (!find_interface(ifndx)) {
if (verbose)
printf("ignoring change on interface #%d\n", ifndx);
return;
}
} else if (i == RTA_IFA) {
ifa = sa;
} else if (i == RTA_BRD) {
brd = sa;
}
ADVANCE(cp, sa);
}
}
if (ifa != NULL)
invoke_script(ifa, brd, is_up, ifndx);
}
static void
invoke_script(sa, dest, is_up, ifindex)
struct sockaddr *sa, *dest;
int is_up, ifindex;
{
char addr[NI_MAXHOST], daddr[NI_MAXHOST], ifname_buf[IFNAMSIZ],
*ifname, *cmd;
const char *script;
daddr[0] = 0;
ifname = if_indextoname(ifindex, ifname_buf);
if (sa->sa_len == 0) {
fprintf(stderr, "illegal socket address (sa_len == 0)\n");
return;
}
if (getnameinfo(sa, sa->sa_len, addr, sizeof addr, NULL, 0, NI_NUMERICHOST)) {
if (verbose)
printf("getnameinfo failed\n");
return; /* this address can not be handled */
}
if (dest != NULL) {
if (getnameinfo(dest, dest->sa_len, daddr, sizeof daddr, NULL, 0, NI_NUMERICHOST)) {
if (verbose)
printf("getnameinfo failed\n");
return; /* this address can not be handled */
}
}
script = is_up? up_script : down_script;
if (script == NULL) return;
asprintf(&cmd, "%s \"%s\" %s \"%s\" \"%s\"", script, ifname,
is_up?"up":"down", addr, daddr);
if (cmd == NULL) {
fprintf(stderr, "out of memory\n");
return;
}
if (verbose)
printf("calling: %s\n", cmd);
system(cmd);
free(cmd);
}
static void list_interfaces(const char *ifnames)
{
char * names = strdup(ifnames);
char * name, *lasts;
static const char sep[] = " \t";
struct interface_data * p;
for (name = strtok_r(names, sep, &lasts); name != NULL; name = strtok_r(NULL, sep, &lasts)) {
p = malloc(sizeof(*p));
SLIST_INSERT_HEAD(&ifs, p, next);
p->ifname = strdup(name);
p->index = if_nametoindex(p->ifname);
if (verbose)
printf("interface \"%s\" has index %d\n", p->ifname, p->index);
}
free(names);
}
static void rescan_interfaces()
{
struct interface_data * p;
SLIST_FOREACH(p, &ifs, next) {
p->index = if_nametoindex(p->ifname);
if (verbose)
printf("interface \"%s\" has index %d\n", p->ifname, p->index);
}
}
static void free_interfaces()
{
struct interface_data * p;
while (!SLIST_EMPTY(&ifs)) {
p = SLIST_FIRST(&ifs);
SLIST_REMOVE_HEAD(&ifs, next);
free(p->ifname);
free(p);
}
}
static int find_interface(index)
int index;
{
struct interface_data * p;
SLIST_FOREACH(p, &ifs, next)
if (p->index == index)
return 1;
return 0;
}
static void run_initial_ups()
{
struct interface_data * ifd;
struct ifaddrs *res = NULL, *p;
if (getifaddrs(&res) == 0) {
for (p = res; p; p = p->ifa_next) {
if ((p->ifa_flags & IFF_UP) == 0)
continue;
if (p->ifa_addr == NULL)
continue;
if (p->ifa_addr->sa_family == AF_LINK)
continue;
SLIST_FOREACH(ifd, &ifs, next) {
if (strcmp(ifd->ifname, p->ifa_name) == 0) {
if (if_is_connected(ifd->ifname))
invoke_script(p->ifa_addr, p->ifa_dstaddr, 1, ifd->index);
break;
}
}
}
freeifaddrs(res);
}
}
#ifdef SPPP_IF_SUPPORT
/*
* Special case support for in-kernel PPP interfaces.
* If these are IFF_UP, but have not yet connected or completed authentication
* we don't want to call the up script in the initial interface scan (there
* will be an UP event generated later, when IPCP completes, anyway).
*
* If this is no if_spppsubr.c based interface, this ioctl just fails and we
* treat is as connected.
*/
static int
if_is_connected(const char * ifname)
{
int s, err;
struct spppstatus status;
memset(&status, 0, sizeof status);
strncpy(status.ifname, ifname, sizeof status.ifname);
s = socket(AF_INET, SOCK_DGRAM, 0);
if (s < 0)
return 1; /* no idea how to handle this... */
err = ioctl(s, SPPPGETSTATUS, &status);
if (err != 0)
/* not if_spppsubr.c based - call it connected */
status.phase = SPPP_PHASE_NETWORK;
close(s);
return status.phase == SPPP_PHASE_NETWORK;
}
#endif