freebsd-src/sbin/dhclient/dispatch.c
Sam Leffler f8c44ada2e Fix the logic to count the number of "live interfaces". With this change
dhclient now terminates when the underlying ifnet is destroyed (e.g.
on card eject).

Reviewed by:	brooks
Approved by:	re (kib)
2009-07-21 15:06:10 +00:00

504 lines
12 KiB
C

/* $OpenBSD: dispatch.c,v 1.31 2004/09/21 04:07:03 david 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "dhcpd.h"
#include <sys/ioctl.h>
#include <net/if_media.h>
#include <ifaddrs.h>
#include <poll.h>
struct protocol *protocols;
struct timeout *timeouts;
static struct timeout *free_timeouts;
static int interfaces_invalidated;
void (*bootp_packet_handler)(struct interface_info *,
struct dhcp_packet *, int, unsigned int,
struct iaddr, struct hardware *);
static int interface_status(struct interface_info *ifinfo);
/*
* 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_interfaces(struct interface_info *iface)
{
struct ifaddrs *ifap, *ifa;
struct sockaddr_in foo;
struct ifreq *tif;
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(iface->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;
iface->index = foo->sdl_index;
iface->hw_address.hlen = foo->sdl_alen;
iface->hw_address.htype = HTYPE_ETHER; /* XXX */
memcpy(iface->hw_address.haddr,
LLADDR(foo), foo->sdl_alen);
} else if (ifa->ifa_addr->sa_family == AF_INET) {
struct iaddr addr;
memcpy(&foo, ifa->ifa_addr, sizeof(foo));
if (foo.sin_addr.s_addr == htonl(INADDR_LOOPBACK))
continue;
if (!iface->ifp) {
int len = IFNAMSIZ + ifa->ifa_addr->sa_len;
if ((tif = malloc(len)) == NULL)
error("no space to remember ifp");
strlcpy(tif->ifr_name, ifa->ifa_name, IFNAMSIZ);
memcpy(&tif->ifr_addr, ifa->ifa_addr,
ifa->ifa_addr->sa_len);
iface->ifp = tif;
iface->primary_address = foo.sin_addr;
}
addr.len = 4;
memcpy(addr.iabuf, &foo.sin_addr.s_addr, addr.len);
}
}
if (!iface->ifp)
error("%s: not found", iface->name);
/* Register the interface... */
if_register_receive(iface);
if_register_send(iface);
add_protocol(iface->name, iface->rfdesc, got_one, iface);
freeifaddrs(ifap);
}
void
reinitialize_interfaces(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 through the
* bootp_packet_handler hook to try to do something with it.
*/
void
dispatch(void)
{
int count, live_interfaces, i, to_msec, nfds = 0;
struct protocol *l;
struct pollfd *fds;
time_t howlong;
for (l = protocols; l; l = l->next)
nfds++;
fds = malloc(nfds * sizeof(struct pollfd));
if (fds == NULL)
error("Can't allocate poll structures.");
do {
/*
* Call any expired timeouts, and then if there's still
* a timeout registered, time out the select call then.
*/
another:
if (timeouts) {
struct timeout *t;
if (timeouts->when <= cur_time) {
t = timeouts;
timeouts = timeouts->next;
(*(t->func))(t->what);
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. */
live_interfaces = 0;
for (i = 0, l = protocols; l; l = l->next) {
struct interface_info *ip = l->local;
if (ip == NULL || ip->dead)
continue;
fds[i].fd = l->fd;
fds[i].events = POLLIN;
fds[i].revents = 0;
i++;
if (l->handler == got_one)
live_interfaces++;
}
if (live_interfaces == 0)
error("No live interfaces to poll on - exiting.");
/* Wait for a packet or a timeout... XXX */
count = poll(fds, nfds, to_msec);
/* Not likely to be transitory... */
if (count == -1) {
if (errno == EAGAIN || errno == EINTR) {
time(&cur_time);
continue;
} else
error("poll: %m");
}
/* Get the current time... */
time(&cur_time);
i = 0;
for (l = protocols; l; l = l->next) {
struct interface_info *ip;
ip = l->local;
if ((fds[i].revents & (POLLIN | POLLHUP))) {
fds[i].revents = 0;
if (ip && (l->handler != got_one ||
!ip->dead))
(*(l->handler))(l);
if (interfaces_invalidated)
break;
}
i++;
}
interfaces_invalidated = 0;
} while (1);
}
void
got_one(struct protocol *l)
{
struct sockaddr_in from;
struct hardware hfrom;
struct iaddr ifrom;
ssize_t result;
union {
/*
* Packet input buffer. Must be as large as largest
* possible MTU.
*/
unsigned char packbuf[4095];
struct dhcp_packet packet;
} u;
struct interface_info *ip = l->local;
if ((result = receive_packet(ip, u.packbuf, sizeof(u), &from,
&hfrom)) == -1) {
warning("receive_packet failed on %s: %s", ip->name,
strerror(errno));
ip->errors++;
if ((!interface_status(ip)) ||
(ip->noifmedia && ip->errors > 20)) {
/* our interface has gone away. */
warning("Interface %s no longer appears valid.",
ip->name);
ip->dead = 1;
interfaces_invalidated = 1;
close(l->fd);
remove_protocol(l);
free(ip);
}
return;
}
if (result == 0)
return;
if (bootp_packet_handler) {
ifrom.len = 4;
memcpy(ifrom.iabuf, &from.sin_addr, ifrom.len);
(*bootp_packet_handler)(ip, &u.packet, result,
from.sin_port, ifrom, &hfrom);
}
}
int
interface_status(struct interface_info *ifinfo)
{
char *ifname = ifinfo->name;
int ifsock = ifinfo->rfdesc;
struct ifreq ifr;
struct ifmediareq ifmr;
/* get interface flags */
memset(&ifr, 0, sizeof(ifr));
strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
if (ioctl(ifsock, SIOCGIFFLAGS, &ifr) < 0) {
syslog(LOG_ERR, "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 (ifinfo->noifmedia)
goto active;
memset(&ifmr, 0, sizeof(ifmr));
strlcpy(ifmr.ifm_name, ifname, sizeof(ifmr.ifm_name));
if (ioctl(ifsock, SIOCGIFMEDIA, (caddr_t)&ifmr) < 0) {
if (errno != EINVAL) {
syslog(LOG_DEBUG, "ioctl(SIOCGIFMEDIA) on %s: %m",
ifname);
ifinfo->noifmedia = 1;
goto active;
}
/*
* EINVAL (or ENOTTY) simply means that the interface
* does not support the SIOCGIFMEDIA ioctl. We regard it alive.
*/
ifinfo->noifmedia = 1;
goto active;
}
if (ifmr.ifm_status & IFM_AVALID) {
switch (ifmr.ifm_active & IFM_NMASK) {
case IFM_ETHER:
case IFM_IEEE80211:
if (ifmr.ifm_status & IFM_ACTIVE)
goto active;
else
goto inactive;
break;
default:
goto inactive;
}
}
inactive:
return (0);
active:
return (1);
}
void
add_timeout(time_t when, void (*where)(void *), void *what)
{
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 && q->what == what) {
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;
q->what = what;
} else {
q = malloc(sizeof(struct timeout));
if (!q)
error("Can't allocate timeout structure!");
q->func = where;
q->what = what;
}
}
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 *), void *what)
{
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 && q->what == what) {
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;
}
}
/* Add a protocol to the list of protocols... */
void
add_protocol(char *name, int fd, void (*handler)(struct protocol *),
void *local)
{
struct protocol *p;
p = malloc(sizeof(*p));
if (!p)
error("can't allocate protocol struct for %s", name);
p->fd = fd;
p->handler = handler;
p->local = local;
p->next = protocols;
protocols = p;
}
void
remove_protocol(struct protocol *proto)
{
struct protocol *p, *next, *prev;
prev = NULL;
for (p = protocols; p; p = next) {
next = p->next;
if (p == proto) {
if (prev)
prev->next = p->next;
else
protocols = p->next;
free(p);
}
}
}
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 -> link state unknown. treat as active */
if (errno != EINVAL)
syslog(LOG_DEBUG, "ioctl(SIOCGIFMEDIA) on %s: %m",
ifname);
close(sock);
return (1);
}
close(sock);
if (ifmr.ifm_status & IFM_AVALID) {
switch (ifmr.ifm_active & IFM_NMASK) {
case IFM_ETHER:
case IFM_IEEE80211:
if (ifmr.ifm_status & IFM_ACTIVE)
return (1);
else
return (0);
}
}
return (1);
}