OpenBSD-4.6/sbin/dhclient/dispatch.c
/* $OpenBSD: dispatch.c,v 1.44 2009/06/06 04:02:42 krw Exp $ */
/*
* Copyright 2004 Henning Brauer <henning@openbsd.org>
* Copyright (c) 1995, 1996, 1997, 1998, 1999
* The Internet Software Consortium. 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. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of The Internet Software Consortium nor the names
* of its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
* CONTRIBUTORS ``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 INTERNET SOFTWARE CONSORTIUM OR
* CONTRIBUTORS 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.
*
* This software has been written for the Internet Software Consortium
* by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
* Enterprises. To learn more about the Internet Software Consortium,
* see ``http://www.vix.com/isc''. To learn more about Vixie
* Enterprises, see ``http://www.vix.com''.
*/
#include "dhcpd.h"
#include <sys/ioctl.h>
#include <net/if_media.h>
#include <ifaddrs.h>
#include <poll.h>
struct timeout *timeouts;
static struct timeout *free_timeouts;
static int interfaces_invalidated;
/*
* Use getifaddrs() to get a list of all the attached interfaces. For
* each interface that's of type INET and not the loopback interface,
* register that interface with the network I/O software, figure out
* what subnet it's on, and add it to the list of interfaces.
*/
void
discover_interface(void)
{
struct ifaddrs *ifap, *ifa;
struct ifreq *tif;
int len = IFNAMSIZ + sizeof(struct sockaddr_storage);
if (getifaddrs(&ifap) != 0)
error("getifaddrs failed");
for (ifa = ifap; ifa != NULL; ifa = ifa->ifa_next) {
if ((ifa->ifa_flags & IFF_LOOPBACK) ||
(ifa->ifa_flags & IFF_POINTOPOINT) ||
(!(ifa->ifa_flags & IFF_UP)))
continue;
if (strcmp(ifi->name, ifa->ifa_name))
continue;
/*
* If we have the capability, extract link information
* and record it in a linked list.
*/
if (ifa->ifa_addr->sa_family == AF_LINK) {
struct sockaddr_dl *foo =
(struct sockaddr_dl *)ifa->ifa_addr;
ifi->index = foo->sdl_index;
ifi->hw_address.hlen = foo->sdl_alen;
ifi->hw_address.htype = HTYPE_ETHER; /* XXX */
memcpy(ifi->hw_address.haddr,
LLADDR(foo), foo->sdl_alen);
}
if (!ifi->ifp) {
if ((tif = malloc(len)) == NULL)
error("no space to remember ifp");
strlcpy(tif->ifr_name, ifa->ifa_name, IFNAMSIZ);
ifi->ifp = tif;
}
}
if (!ifi->ifp)
error("%s: not found", ifi->name);
/* Register the interface... */
if_register_receive();
if_register_send();
freeifaddrs(ifap);
}
void
reinitialize_interface(void)
{
interfaces_invalidated = 1;
}
/*
* Wait for packets to come in using poll(). When a packet comes in, call
* receive_packet to receive the packet and possibly strip hardware addressing
* information from it, and then call do_packet to try to do something with it.
*/
void
dispatch(void)
{
int count, to_msec;
struct pollfd fds[2];
time_t howlong;
do {
/*
* Call any expired timeouts, and then if there's still
* a timeout registered, time out the select call then.
*/
another:
if (!ifi->linkstat)
interfaces_invalidated = 0;
if (timeouts) {
struct timeout *t;
if (timeouts->when <= cur_time) {
t = timeouts;
timeouts = timeouts->next;
(*(t->func))();
t->next = free_timeouts;
free_timeouts = t;
goto another;
}
/*
* Figure timeout in milliseconds, and check for
* potential overflow, so we can cram into an
* int for poll, while not polling with a
* negative timeout and blocking indefinitely.
*/
howlong = timeouts->when - cur_time;
if (howlong > INT_MAX / 1000)
howlong = INT_MAX / 1000;
to_msec = howlong * 1000;
} else
to_msec = -1;
/* Set up the descriptors to be polled. */
if (!ifi || ifi->rfdesc == -1)
error("No live interface to poll on");
fds[0].fd = ifi->rfdesc;
fds[1].fd = routefd; /* Could be -1, which will be ignored. */
fds[0].events = fds[1].events = POLLIN;
/* Wait for a packet or a timeout... XXX */
count = poll(fds, 2, to_msec);
/* Get the current time... */
time(&cur_time);
/* Not likely to be transitory... */
if (count == -1) {
if (errno == EAGAIN || errno == EINTR) {
continue;
} else
error("poll: %m");
}
if ((fds[0].revents & (POLLIN | POLLHUP))) {
if (ifi && ifi->linkstat && ifi->rfdesc != -1)
got_one();
}
if ((fds[1].revents & (POLLIN | POLLHUP))) {
if (ifi && !interfaces_invalidated)
routehandler();
}
interfaces_invalidated = 0;
} while (1);
}
void
got_one(void)
{
struct sockaddr_in from;
struct hardware hfrom;
struct iaddr ifrom;
ssize_t result;
if ((result = receive_packet(&from, &hfrom)) == -1) {
warning("receive_packet failed on %s: %s", ifi->name,
strerror(errno));
ifi->errors++;
if ((!interface_status(ifi->name)) ||
(ifi->noifmedia && ifi->errors > 20)) {
/* our interface has gone away. */
warning("Interface %s no longer appears valid.",
ifi->name);
interfaces_invalidated = 1;
close(ifi->rfdesc);
ifi->rfdesc = -1;
}
return;
}
if (result == 0)
return;
ifrom.len = 4;
memcpy(ifrom.iabuf, &from.sin_addr, ifrom.len);
do_packet(result, from.sin_port, ifrom, &hfrom);
}
int
interface_link_forceup(char *ifname)
{
struct ifreq ifr;
int sock;
if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
error("Can't create socket");
memset(&ifr, 0, sizeof(ifr));
strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
if (ioctl(sock, SIOCGIFFLAGS, (caddr_t)&ifr) == -1) {
close(sock);
return (-1);
}
if ((ifr.ifr_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
ifr.ifr_flags |= IFF_UP;
if (ioctl(sock, SIOCSIFFLAGS, (caddr_t)&ifr) == -1) {
close(sock);
return (-1);
}
close(sock);
return (0);
}
close(sock);
return (1);
}
void
interface_link_forcedown(char *ifname)
{
struct ifreq ifr;
int sock;
if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
error("Can't create socket");
memset(&ifr, 0, sizeof(ifr));
strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
if (ioctl(sock, SIOCGIFFLAGS, (caddr_t)&ifr) == -1) {
close(sock);
return;
}
if ((ifr.ifr_flags & IFF_UP) == IFF_UP) {
ifr.ifr_flags &= ~IFF_UP;
if (ioctl(sock, SIOCSIFFLAGS, (caddr_t)&ifr) == -1) {
close(sock);
return;
}
}
close(sock);
}
int
interface_status(char *ifname)
{
struct ifreq ifr;
struct ifmediareq ifmr;
int sock;
if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
error("Can't create socket");
/* get interface flags */
memset(&ifr, 0, sizeof(ifr));
strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
if (ioctl(sock, SIOCGIFFLAGS, &ifr) < 0) {
warning("ioctl(SIOCGIFFLAGS) on %s: %m", ifname);
goto inactive;
}
/*
* if one of UP and RUNNING flags is dropped,
* the interface is not active.
*/
if ((ifr.ifr_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING))
goto inactive;
/* Next, check carrier on the interface, if possible */
if (ifi->noifmedia)
goto active;
memset(&ifmr, 0, sizeof(ifmr));
strlcpy(ifmr.ifm_name, ifname, sizeof(ifmr.ifm_name));
if (ioctl(sock, SIOCGIFMEDIA, (caddr_t)&ifmr) < 0) {
/*
* EINVAL or ENOTTY simply means that the interface
* does not support the SIOCGIFMEDIA ioctl. We regard it alive.
*/
#ifdef DEBUG
if (errno != EINVAL && errno != ENOTTY)
debug("ioctl(SIOCGIFMEDIA) on %s: %m", ifname);
#endif
ifi->noifmedia = 1;
goto active;
}
if (ifmr.ifm_status & IFM_AVALID) {
if (ifmr.ifm_status & IFM_ACTIVE)
goto active;
else
goto inactive;
}
inactive:
close(sock);
return (0);
active:
close(sock);
return (1);
}
void
add_timeout(time_t when, void (*where)(void))
{
struct timeout *t, *q;
/* See if this timeout supersedes an existing timeout. */
t = NULL;
for (q = timeouts; q; q = q->next) {
if (q->func == where) {
if (t)
t->next = q->next;
else
timeouts = q->next;
break;
}
t = q;
}
/* If we didn't supersede a timeout, allocate a timeout
structure now. */
if (!q) {
if (free_timeouts) {
q = free_timeouts;
free_timeouts = q->next;
q->func = where;
} else {
q = malloc(sizeof(struct timeout));
if (!q)
error("Can't allocate timeout structure!");
q->func = where;
}
}
q->when = when;
/* Now sort this timeout into the timeout list. */
/* Beginning of list? */
if (!timeouts || timeouts->when > q->when) {
q->next = timeouts;
timeouts = q;
return;
}
/* Middle of list? */
for (t = timeouts; t->next; t = t->next) {
if (t->next->when > q->when) {
q->next = t->next;
t->next = q;
return;
}
}
/* End of list. */
t->next = q;
q->next = NULL;
}
void
cancel_timeout(void (*where)(void))
{
struct timeout *t, *q;
/* Look for this timeout on the list, and unlink it if we find it. */
t = NULL;
for (q = timeouts; q; q = q->next) {
if (q->func == where) {
if (t)
t->next = q->next;
else
timeouts = q->next;
break;
}
t = q;
}
/* If we found the timeout, put it on the free list. */
if (q) {
q->next = free_timeouts;
free_timeouts = q;
}
}
int
interface_link_status(char *ifname)
{
struct ifmediareq ifmr;
int sock;
if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
error("Can't create socket");
memset(&ifmr, 0, sizeof(ifmr));
strlcpy(ifmr.ifm_name, ifname, sizeof(ifmr.ifm_name));
if (ioctl(sock, SIOCGIFMEDIA, (caddr_t)&ifmr) == -1) {
/* EINVAL/ENOTTY -> link state unknown. treat as active */
#ifdef DEBUG
if (errno != EINVAL && errno != ENOTTY)
debug("ioctl(SIOCGIFMEDIA) on %s: %m", ifname);
#endif
close(sock);
return (1);
}
close(sock);
if (ifmr.ifm_status & IFM_AVALID) {
if (ifmr.ifm_status & IFM_ACTIVE)
return (1);
else
return (0);
}
return (1);
}