diff options
Diffstat (limited to 'ipv4ll.c')
| -rw-r--r-- | ipv4ll.c | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/ipv4ll.c b/ipv4ll.c new file mode 100644 index 0000000..4336540 --- /dev/null +++ b/ipv4ll.c @@ -0,0 +1,156 @@ +/* + * dhcpcd - DHCP client daemon + * Copyright (c) 2006-2008 Roy Marples <roy@marples.name> + * 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. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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. + */ + +#include <errno.h> +#include <signal.h> +#include <stdlib.h> +#include <string.h> +#include <syslog.h> +#include <unistd.h> + +#include "arp.h" +#include "common.h" +#include "dhcpcd.h" +#include "eloop.h" +#include "if-options.h" +#include "ipv4ll.h" +#include "net.h" + +static struct dhcp_message * +make_ipv4ll_lease(uint32_t addr) +{ + uint32_t u32; + struct dhcp_message *dhcp; + uint8_t *p; + + dhcp = xzalloc(sizeof(*dhcp)); + /* Put some LL options in */ + dhcp->yiaddr = addr; + p = dhcp->options; + *p++ = DHO_SUBNETMASK; + *p++ = sizeof(u32); + u32 = htonl(LINKLOCAL_MASK); + memcpy(p, &u32, sizeof(u32)); + p += sizeof(u32); + *p++ = DHO_BROADCAST; + *p++ = sizeof(u32); + u32 = htonl(LINKLOCAL_BRDC); + memcpy(p, &u32, sizeof(u32)); + p += sizeof(u32); + *p++ = DHO_END; + + return dhcp; +} + +static struct dhcp_message * +find_ipv4ll_lease(uint32_t old_addr) +{ + uint32_t addr; + + for (;;) { + addr = htonl(LINKLOCAL_ADDR | + (((uint32_t)abs((int)arc4random()) + % 0xFD00) + 0x0100)); + if (addr != old_addr && + IN_LINKLOCAL(ntohl(addr))) + break; + } + return make_ipv4ll_lease(addr); +} + +void +start_ipv4ll(void *arg) +{ + struct interface *iface = arg; + uint32_t addr; + + delete_timeout(NULL, iface); + iface->state->probes = 0; + iface->state->claims = 0; + if (iface->addr.s_addr) { + iface->state->conflicts = 0; + if (IN_LINKLOCAL(htonl(iface->addr.s_addr))) { + send_arp_announce(iface); + return; + } + } + + if (iface->state->offer == NULL) + addr = 0; + else { + addr = iface->state->offer->yiaddr; + free(iface->state->offer); + } + /* We maybe rebooting an IPv4LL address. */ + if (!IN_LINKLOCAL(htonl(addr))) { + syslog(LOG_INFO, "%s: probing for an IPv4LL address", + iface->name); + addr = 0; + } + if (addr == 0) + iface->state->offer = find_ipv4ll_lease(addr); + else + iface->state->offer = make_ipv4ll_lease(addr); + iface->state->lease.frominfo = 0; + send_arp_probe(iface); +} + +void +handle_ipv4ll_failure(void *arg) +{ + struct interface *iface = arg; + time_t up; + + if (iface->state->fail.s_addr == iface->addr.s_addr) { + up = uptime(); + if (iface->state->defend + DEFEND_INTERVAL > up) { + syslog(LOG_DEBUG, + "%s: IPv4LL %d second defence failed", + iface->name, DEFEND_INTERVAL); + drop_config(iface, "EXPIRE"); + iface->state->conflicts = -1; + } else { + syslog(LOG_DEBUG, "%s: defended IPv4LL address", + iface->name); + iface->state->defend = up; + return; + } + } + + close_sockets(iface); + free(iface->state->offer); + iface->state->offer = NULL; + delete_timeout(NULL, iface); + if (++iface->state->conflicts > MAX_CONFLICTS) { + syslog(LOG_ERR, "%s: failed to acquire an IPv4LL address", + iface->name); + iface->state->interval = RATE_LIMIT_INTERVAL / 2; + start_discover(iface); + } else { + add_timeout_sec(PROBE_WAIT, start_ipv4ll, iface); + } +} |