157 lines
4.1 KiB
C
157 lines
4.1 KiB
C
/*
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* dhcpcd - DHCP client daemon
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* Copyright (c) 2006-2008 Roy Marples <roy@marples.name>
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* All rights reserved
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <errno.h>
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#include <signal.h>
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#include <stdlib.h>
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#include <string.h>
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#include <syslog.h>
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#include <unistd.h>
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#include "arp.h"
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#include "common.h"
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#include "dhcpcd.h"
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#include "eloop.h"
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#include "if-options.h"
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#include "ipv4ll.h"
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#include "net.h"
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static struct dhcp_message *
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make_ipv4ll_lease(uint32_t addr)
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{
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uint32_t u32;
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struct dhcp_message *dhcp;
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uint8_t *p;
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dhcp = xzalloc(sizeof(*dhcp));
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/* Put some LL options in */
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dhcp->yiaddr = addr;
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p = dhcp->options;
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*p++ = DHO_SUBNETMASK;
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*p++ = sizeof(u32);
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u32 = htonl(LINKLOCAL_MASK);
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memcpy(p, &u32, sizeof(u32));
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p += sizeof(u32);
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*p++ = DHO_BROADCAST;
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*p++ = sizeof(u32);
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u32 = htonl(LINKLOCAL_BRDC);
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memcpy(p, &u32, sizeof(u32));
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p += sizeof(u32);
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*p++ = DHO_END;
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return dhcp;
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}
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static struct dhcp_message *
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find_ipv4ll_lease(uint32_t old_addr)
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{
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uint32_t addr;
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for (;;) {
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addr = htonl(LINKLOCAL_ADDR |
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(((uint32_t)abs((int)arc4random())
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% 0xFD00) + 0x0100));
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if (addr != old_addr &&
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IN_LINKLOCAL(ntohl(addr)))
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break;
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}
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return make_ipv4ll_lease(addr);
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}
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void
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start_ipv4ll(void *arg)
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{
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struct interface *iface = arg;
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uint32_t addr;
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delete_timeout(NULL, iface);
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iface->state->probes = 0;
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iface->state->claims = 0;
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if (iface->addr.s_addr) {
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iface->state->conflicts = 0;
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if (IN_LINKLOCAL(htonl(iface->addr.s_addr))) {
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send_arp_announce(iface);
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return;
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}
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}
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if (iface->state->offer == NULL)
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addr = 0;
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else {
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addr = iface->state->offer->yiaddr;
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free(iface->state->offer);
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}
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/* We maybe rebooting an IPv4LL address. */
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if (!IN_LINKLOCAL(htonl(addr))) {
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syslog(LOG_INFO, "%s: probing for an IPv4LL address",
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iface->name);
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addr = 0;
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}
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if (addr == 0)
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iface->state->offer = find_ipv4ll_lease(addr);
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else
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iface->state->offer = make_ipv4ll_lease(addr);
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iface->state->lease.frominfo = 0;
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send_arp_probe(iface);
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}
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void
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handle_ipv4ll_failure(void *arg)
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{
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struct interface *iface = arg;
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time_t up;
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if (iface->state->fail.s_addr == iface->addr.s_addr) {
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up = uptime();
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if (iface->state->defend + DEFEND_INTERVAL > up) {
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syslog(LOG_DEBUG,
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"%s: IPv4LL %d second defence failed",
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iface->name, DEFEND_INTERVAL);
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drop_config(iface, "EXPIRE");
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iface->state->conflicts = -1;
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} else {
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syslog(LOG_DEBUG, "%s: defended IPv4LL address",
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iface->name);
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iface->state->defend = up;
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return;
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}
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}
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close_sockets(iface);
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free(iface->state->offer);
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iface->state->offer = NULL;
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delete_timeout(NULL, iface);
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if (++iface->state->conflicts > MAX_CONFLICTS) {
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syslog(LOG_ERR, "%s: failed to acquire an IPv4LL address",
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iface->name);
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iface->state->interval = RATE_LIMIT_INTERVAL / 2;
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start_discover(iface);
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} else {
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add_timeout_sec(PROBE_WAIT, start_ipv4ll, iface);
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}
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}
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