diff options
Diffstat (limited to 'dhcpcd/ipv4ll.c')
| -rw-r--r-- | dhcpcd/ipv4ll.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/dhcpcd/ipv4ll.c b/dhcpcd/ipv4ll.c new file mode 100644 index 00000000..731a6f4b --- /dev/null +++ b/dhcpcd/ipv4ll.c @@ -0,0 +1,170 @@ +/* + * dhcpcd - DHCP client daemon + * Copyright (c) 2006-2014 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 "config.h" +#include "arp.h" +#include "common.h" +#include "dhcp.h" +#include "eloop.h" +#include "if-options.h" +#include "ipv4ll.h" +#include "net.h" + +static struct dhcp_message * +ipv4ll_make_lease(uint32_t addr) +{ + uint32_t u32; + struct dhcp_message *dhcp; + uint8_t *p; + + dhcp = calloc(1, sizeof(*dhcp)); + if (dhcp == NULL) + return NULL; + /* 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 * +ipv4ll_find_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 ipv4ll_make_lease(addr); +} + +void +ipv4ll_start(void *arg) +{ + struct interface *ifp = arg; + struct dhcp_state *state = D_STATE(ifp); + uint32_t addr; + + eloop_timeout_delete(NULL, ifp); + state->probes = 0; + state->claims = 0; + if (state->addr.s_addr) { + state->conflicts = 0; + if (IN_LINKLOCAL(htonl(state->addr.s_addr))) { + arp_announce(ifp); + return; + } + } + + if (state->offer == NULL) + addr = 0; + else { + addr = state->offer->yiaddr; + free(state->offer); + } + /* We maybe rebooting an IPv4LL address. */ + if (!IN_LINKLOCAL(htonl(addr))) { + syslog(LOG_INFO, "%s: probing for an IPv4LL address", + ifp->name); + addr = 0; + } + if (addr == 0) + state->offer = ipv4ll_find_lease(addr); + else + state->offer = ipv4ll_make_lease(addr); + if (state->offer == NULL) + syslog(LOG_ERR, "%s: %m", __func__); + else { + state->lease.frominfo = 0; + arp_probe(ifp); + } +} + +void +ipv4ll_handle_failure(void *arg) +{ + struct interface *ifp = arg; + struct dhcp_state *state = D_STATE(ifp); + time_t up; + + if (state->fail.s_addr == state->addr.s_addr) { + /* RFC 3927 Section 2.5 */ + up = uptime(); + if (state->defend + DEFEND_INTERVAL > up) { + syslog(LOG_WARNING, + "%s: IPv4LL %d second defence failed", + ifp->name, DEFEND_INTERVAL); + dhcp_drop(ifp, "EXPIRE"); + state->conflicts = -1; + } else { + syslog(LOG_DEBUG, "%s: defended IPv4LL address", + ifp->name); + state->defend = up; + return; + } + } + + dhcp_close(ifp); + free(state->offer); + state->offer = NULL; + eloop_timeout_delete(NULL, ifp); + if (++state->conflicts > MAX_CONFLICTS) { + syslog(LOG_ERR, "%s: failed to acquire an IPv4LL address", + ifp->name); + if (ifp->options->options & DHCPCD_DHCP) { + state->interval = RATE_LIMIT_INTERVAL / 2; + dhcp_discover(ifp); + } else + eloop_timeout_add_sec(RATE_LIMIT_INTERVAL, + ipv4ll_start, ifp); + } else { + eloop_timeout_add_sec(PROBE_WAIT, ipv4ll_start, ifp); + } +} |