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function old new delta bb_unsetenv_and_free - 17 +17 tcpudpsvd_main 1819 1810 -9 safe_setenv 58 47 -11 udhcp_run_script 630 616 -14 make_device 1683 1663 -20 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 0/4 up/down: 17/-54) Total: -37 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
1318 lines
38 KiB
C
1318 lines
38 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* udhcp client
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*
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* Russ Dill <Russ.Dill@asu.edu> July 2001
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <syslog.h>
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/* Override ENABLE_FEATURE_PIDFILE - ifupdown needs our pidfile to always exist */
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#define WANT_PIDFILE 1
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#include "common.h"
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#include "dhcpd.h"
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#include "dhcpc.h"
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#include <asm/types.h>
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#if (defined(__GLIBC__) && __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 1) || defined(_NEWLIB_VERSION)
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# include <netpacket/packet.h>
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# include <net/ethernet.h>
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#else
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# include <linux/if_packet.h>
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# include <linux/if_ether.h>
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#endif
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#include <linux/filter.h>
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/* struct client_config_t client_config is in bb_common_bufsiz1 */
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/*** Script execution code ***/
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/* get a rough idea of how long an option will be (rounding up...) */
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static const uint8_t len_of_option_as_string[] = {
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[OPTION_IP ] = sizeof("255.255.255.255 "),
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[OPTION_IP_PAIR ] = sizeof("255.255.255.255 ") * 2,
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[OPTION_STATIC_ROUTES ] = sizeof("255.255.255.255/32 255.255.255.255 "),
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[OPTION_STRING ] = 1,
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#if ENABLE_FEATURE_UDHCP_RFC3397
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[OPTION_DNS_STRING ] = 1, /* unused */
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/* Hmmm, this severely overestimates size if SIP_SERVERS option
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* is in domain name form: N-byte option in binary form
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* mallocs ~16*N bytes. But it is freed almost at once.
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*/
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[OPTION_SIP_SERVERS ] = sizeof("255.255.255.255 "),
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#endif
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// [OPTION_BOOLEAN ] = sizeof("yes "),
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[OPTION_U8 ] = sizeof("255 "),
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[OPTION_U16 ] = sizeof("65535 "),
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// [OPTION_S16 ] = sizeof("-32768 "),
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[OPTION_U32 ] = sizeof("4294967295 "),
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[OPTION_S32 ] = sizeof("-2147483684 "),
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};
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/* note: ip is a pointer to an IP in network order, possibly misaliged */
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static int sprint_nip(char *dest, const char *pre, const uint8_t *ip)
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{
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return sprintf(dest, "%s%u.%u.%u.%u", pre, ip[0], ip[1], ip[2], ip[3]);
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}
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/* really simple implementation, just count the bits */
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static int mton(uint32_t mask)
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{
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int i = 0;
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mask = ntohl(mask); /* 111110000-like bit pattern */
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while (mask) {
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i++;
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mask <<= 1;
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}
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return i;
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}
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/* Create "opt_name=opt_value" string */
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static NOINLINE char *xmalloc_optname_optval(uint8_t *option, const struct dhcp_optflag *optflag, const char *opt_name)
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{
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unsigned upper_length;
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int len, type, optlen;
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char *dest, *ret;
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/* option points to OPT_DATA, need to go back and get OPT_LEN */
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len = option[OPT_LEN - OPT_DATA];
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type = optflag->flags & OPTION_TYPE_MASK;
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optlen = dhcp_option_lengths[type];
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upper_length = len_of_option_as_string[type] * ((unsigned)len / (unsigned)optlen);
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dest = ret = xmalloc(upper_length + strlen(opt_name) + 2);
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dest += sprintf(ret, "%s=", opt_name);
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while (len >= optlen) {
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switch (type) {
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case OPTION_IP_PAIR:
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dest += sprint_nip(dest, "", option);
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*dest++ = '/';
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option += 4;
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optlen = 4;
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case OPTION_IP:
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dest += sprint_nip(dest, "", option);
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// TODO: it can be a list only if (optflag->flags & OPTION_LIST).
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// Should we bail out/warn if we see multi-ip option which is
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// not allowed to be such? For example, DHCP_BROADCAST...
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break;
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// case OPTION_BOOLEAN:
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// dest += sprintf(dest, *option ? "yes" : "no");
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// break;
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case OPTION_U8:
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dest += sprintf(dest, "%u", *option);
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break;
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// case OPTION_S16:
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case OPTION_U16: {
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uint16_t val_u16;
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move_from_unaligned16(val_u16, option);
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dest += sprintf(dest, "%u", ntohs(val_u16));
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break;
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}
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case OPTION_S32:
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case OPTION_U32: {
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uint32_t val_u32;
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move_from_unaligned32(val_u32, option);
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dest += sprintf(dest, type == OPTION_U32 ? "%lu" : "%ld", (unsigned long) ntohl(val_u32));
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break;
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}
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case OPTION_STRING:
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memcpy(dest, option, len);
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dest[len] = '\0';
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return ret; /* Short circuit this case */
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case OPTION_STATIC_ROUTES: {
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/* Option binary format:
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* mask [one byte, 0..32]
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* ip [big endian, 0..4 bytes depending on mask]
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* router [big endian, 4 bytes]
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* may be repeated
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*
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* We convert it to a string "IP/MASK ROUTER IP2/MASK2 ROUTER2"
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*/
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const char *pfx = "";
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while (len >= 1 + 4) { /* mask + 0-byte ip + router */
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uint32_t nip;
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uint8_t *p;
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unsigned mask;
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int bytes;
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mask = *option++;
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if (mask > 32)
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break;
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len--;
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nip = 0;
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p = (void*) &nip;
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bytes = (mask + 7) / 8; /* 0 -> 0, 1..8 -> 1, 9..16 -> 2 etc */
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while (--bytes >= 0) {
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*p++ = *option++;
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len--;
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}
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if (len < 4)
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break;
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/* print ip/mask */
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dest += sprint_nip(dest, pfx, (void*) &nip);
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pfx = " ";
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dest += sprintf(dest, "/%u ", mask);
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/* print router */
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dest += sprint_nip(dest, "", option);
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option += 4;
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len -= 4;
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}
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return ret;
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}
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#if ENABLE_FEATURE_UDHCP_RFC3397
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case OPTION_DNS_STRING:
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/* unpack option into dest; use ret for prefix (i.e., "optname=") */
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dest = dname_dec(option, len, ret);
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if (dest) {
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free(ret);
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return dest;
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}
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/* error. return "optname=" string */
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return ret;
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case OPTION_SIP_SERVERS:
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/* Option binary format:
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* type: byte
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* type=0: domain names, dns-compressed
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* type=1: IP addrs
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*/
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option++;
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len--;
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if (option[-1] == 0) {
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dest = dname_dec(option, len, ret);
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if (dest) {
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free(ret);
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return dest;
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}
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} else
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if (option[-1] == 1) {
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const char *pfx = "";
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while (1) {
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len -= 4;
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if (len < 0)
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break;
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dest += sprint_nip(dest, pfx, option);
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pfx = " ";
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option += 4;
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}
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}
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return ret;
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#endif
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} /* switch */
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option += optlen;
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len -= optlen;
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if (len <= 0)
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break;
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*dest++ = ' ';
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*dest = '\0';
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}
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return ret;
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}
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/* put all the parameters into the environment */
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static char **fill_envp(struct dhcp_packet *packet)
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{
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int envc;
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int i;
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char **envp, **curr;
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const char *opt_name;
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uint8_t *temp;
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uint8_t overload = 0;
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/* We need 6 elements for:
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* "interface=IFACE"
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* "ip=N.N.N.N" from packet->yiaddr
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* "siaddr=IP" from packet->siaddr_nip (unless 0)
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* "boot_file=FILE" from packet->file (unless overloaded)
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* "sname=SERVER_HOSTNAME" from packet->sname (unless overloaded)
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* terminating NULL
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*/
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envc = 6;
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/* +1 element for each option, +2 for subnet option: */
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if (packet) {
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for (i = 0; dhcp_optflags[i].code; i++) {
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if (udhcp_get_option(packet, dhcp_optflags[i].code)) {
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if (dhcp_optflags[i].code == DHCP_SUBNET)
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envc++; /* for mton */
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envc++;
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}
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}
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temp = udhcp_get_option(packet, DHCP_OPTION_OVERLOAD);
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if (temp)
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overload = *temp;
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}
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curr = envp = xzalloc(sizeof(char *) * envc);
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*curr = xasprintf("interface=%s", client_config.interface);
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putenv(*curr++);
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if (!packet)
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return envp;
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*curr = xmalloc(sizeof("ip=255.255.255.255"));
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sprint_nip(*curr, "ip=", (uint8_t *) &packet->yiaddr);
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putenv(*curr++);
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opt_name = dhcp_option_strings;
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i = 0;
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while (*opt_name) {
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temp = udhcp_get_option(packet, dhcp_optflags[i].code);
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if (!temp)
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goto next;
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*curr = xmalloc_optname_optval(temp, &dhcp_optflags[i], opt_name);
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putenv(*curr++);
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if (dhcp_optflags[i].code == DHCP_SUBNET) {
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/* Subnet option: make things like "$ip/$mask" possible */
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uint32_t subnet;
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move_from_unaligned32(subnet, temp);
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*curr = xasprintf("mask=%d", mton(subnet));
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putenv(*curr++);
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}
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next:
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opt_name += strlen(opt_name) + 1;
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i++;
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}
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if (packet->siaddr_nip) {
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*curr = xmalloc(sizeof("siaddr=255.255.255.255"));
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sprint_nip(*curr, "siaddr=", (uint8_t *) &packet->siaddr_nip);
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putenv(*curr++);
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}
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if (!(overload & FILE_FIELD) && packet->file[0]) {
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/* watch out for invalid packets */
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*curr = xasprintf("boot_file=%."DHCP_PKT_FILE_LEN_STR"s", packet->file);
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putenv(*curr++);
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}
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if (!(overload & SNAME_FIELD) && packet->sname[0]) {
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/* watch out for invalid packets */
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*curr = xasprintf("sname=%."DHCP_PKT_SNAME_LEN_STR"s", packet->sname);
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putenv(*curr++);
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}
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return envp;
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}
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/* Call a script with a par file and env vars */
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static void udhcp_run_script(struct dhcp_packet *packet, const char *name)
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{
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char **envp, **curr;
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char *argv[3];
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if (client_config.script == NULL)
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return;
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envp = fill_envp(packet);
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/* call script */
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log1("Executing %s %s", client_config.script, name);
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argv[0] = (char*) client_config.script;
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argv[1] = (char*) name;
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argv[2] = NULL;
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spawn_and_wait(argv);
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for (curr = envp; *curr; curr++) {
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log2(" %s", *curr);
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bb_unsetenv_and_free(*curr);
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}
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free(envp);
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}
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/*** Sending/receiving packets ***/
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static ALWAYS_INLINE uint32_t random_xid(void)
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{
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return rand();
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}
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/* Initialize the packet with the proper defaults */
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static void init_packet(struct dhcp_packet *packet, char type)
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{
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udhcp_init_header(packet, type);
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memcpy(packet->chaddr, client_config.client_mac, 6);
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if (client_config.clientid)
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udhcp_add_binary_option(packet, client_config.clientid);
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if (client_config.hostname)
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udhcp_add_binary_option(packet, client_config.hostname);
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if (client_config.fqdn)
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udhcp_add_binary_option(packet, client_config.fqdn);
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if (type != DHCPDECLINE
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&& type != DHCPRELEASE
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&& client_config.vendorclass
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) {
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udhcp_add_binary_option(packet, client_config.vendorclass);
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}
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}
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static void add_client_options(struct dhcp_packet *packet)
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{
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/* Add a "param req" option with the list of options we'd like to have
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* from stubborn DHCP servers. Pull the data from the struct in common.c.
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* No bounds checking because it goes towards the head of the packet. */
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uint8_t c;
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int end = udhcp_end_option(packet->options);
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int i, len = 0;
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for (i = 0; (c = dhcp_optflags[i].code) != 0; i++) {
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if (( (dhcp_optflags[i].flags & OPTION_REQ)
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&& !client_config.no_default_options
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)
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|| (client_config.opt_mask[c >> 3] & (1 << (c & 7)))
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) {
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packet->options[end + OPT_DATA + len] = c;
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len++;
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}
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}
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if (len) {
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packet->options[end + OPT_CODE] = DHCP_PARAM_REQ;
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packet->options[end + OPT_LEN] = len;
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packet->options[end + OPT_DATA + len] = DHCP_END;
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}
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/* Add -x options if any */
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{
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struct option_set *curr = client_config.options;
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while (curr) {
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udhcp_add_binary_option(packet, curr->data);
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curr = curr->next;
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}
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// if (client_config.sname)
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// strncpy((char*)packet->sname, client_config.sname, sizeof(packet->sname) - 1);
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// if (client_config.boot_file)
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// strncpy((char*)packet->file, client_config.boot_file, sizeof(packet->file) - 1);
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}
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}
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/* RFC 2131
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* 4.4.4 Use of broadcast and unicast
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*
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* The DHCP client broadcasts DHCPDISCOVER, DHCPREQUEST and DHCPINFORM
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* messages, unless the client knows the address of a DHCP server.
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* The client unicasts DHCPRELEASE messages to the server. Because
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* the client is declining the use of the IP address supplied by the server,
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* the client broadcasts DHCPDECLINE messages.
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*
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* When the DHCP client knows the address of a DHCP server, in either
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* INIT or REBOOTING state, the client may use that address
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* in the DHCPDISCOVER or DHCPREQUEST rather than the IP broadcast address.
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* The client may also use unicast to send DHCPINFORM messages
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* to a known DHCP server. If the client receives no response to DHCP
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* messages sent to the IP address of a known DHCP server, the DHCP
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* client reverts to using the IP broadcast address.
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*/
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static int raw_bcast_from_client_config_ifindex(struct dhcp_packet *packet)
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{
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return udhcp_send_raw_packet(packet,
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/*src*/ INADDR_ANY, CLIENT_PORT,
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/*dst*/ INADDR_BROADCAST, SERVER_PORT, MAC_BCAST_ADDR,
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client_config.ifindex);
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}
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/* Broadcast a DHCP discover packet to the network, with an optionally requested IP */
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static int send_discover(uint32_t xid, uint32_t requested)
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{
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struct dhcp_packet packet;
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init_packet(&packet, DHCPDISCOVER);
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packet.xid = xid;
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if (requested)
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udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
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/* Explicitly saying that we want RFC-compliant packets helps
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* some buggy DHCP servers to NOT send bigger packets */
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udhcp_add_simple_option(&packet, DHCP_MAX_SIZE, htons(576));
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add_client_options(&packet);
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bb_info_msg("Sending discover...");
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return raw_bcast_from_client_config_ifindex(&packet);
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}
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|
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/* Broadcast a DHCP request message */
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|
/* RFC 2131 3.1 paragraph 3:
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* "The client _broadcasts_ a DHCPREQUEST message..."
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|
*/
|
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static int send_select(uint32_t xid, uint32_t server, uint32_t requested)
|
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{
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struct dhcp_packet packet;
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struct in_addr addr;
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init_packet(&packet, DHCPREQUEST);
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packet.xid = xid;
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udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
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udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
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add_client_options(&packet);
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addr.s_addr = requested;
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bb_info_msg("Sending select for %s...", inet_ntoa(addr));
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return raw_bcast_from_client_config_ifindex(&packet);
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}
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/* Unicast or broadcast a DHCP renew message */
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static int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr)
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{
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struct dhcp_packet packet;
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init_packet(&packet, DHCPREQUEST);
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packet.xid = xid;
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packet.ciaddr = ciaddr;
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add_client_options(&packet);
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bb_info_msg("Sending renew...");
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if (server)
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return udhcp_send_kernel_packet(&packet,
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ciaddr, CLIENT_PORT,
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server, SERVER_PORT);
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return raw_bcast_from_client_config_ifindex(&packet);
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}
|
|
|
|
#if ENABLE_FEATURE_UDHCPC_ARPING
|
|
/* Broadcast a DHCP decline message */
|
|
static int send_decline(uint32_t xid, uint32_t server, uint32_t requested)
|
|
{
|
|
struct dhcp_packet packet;
|
|
|
|
init_packet(&packet, DHCPDECLINE);
|
|
packet.xid = xid;
|
|
udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
|
|
udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
|
|
|
|
bb_info_msg("Sending decline...");
|
|
return raw_bcast_from_client_config_ifindex(&packet);
|
|
}
|
|
#endif
|
|
|
|
/* Unicast a DHCP release message */
|
|
static int send_release(uint32_t server, uint32_t ciaddr)
|
|
{
|
|
struct dhcp_packet packet;
|
|
|
|
init_packet(&packet, DHCPRELEASE);
|
|
packet.xid = random_xid();
|
|
packet.ciaddr = ciaddr;
|
|
|
|
udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
|
|
|
|
bb_info_msg("Sending release...");
|
|
return udhcp_send_kernel_packet(&packet, ciaddr, CLIENT_PORT, server, SERVER_PORT);
|
|
}
|
|
|
|
/* Returns -1 on errors that are fatal for the socket, -2 for those that aren't */
|
|
static NOINLINE int udhcp_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd)
|
|
{
|
|
int bytes;
|
|
struct ip_udp_dhcp_packet packet;
|
|
uint16_t check;
|
|
|
|
memset(&packet, 0, sizeof(packet));
|
|
bytes = safe_read(fd, &packet, sizeof(packet));
|
|
if (bytes < 0) {
|
|
log1("Packet read error, ignoring");
|
|
/* NB: possible down interface, etc. Caller should pause. */
|
|
return bytes; /* returns -1 */
|
|
}
|
|
|
|
if (bytes < (int) (sizeof(packet.ip) + sizeof(packet.udp))) {
|
|
log1("Packet is too short, ignoring");
|
|
return -2;
|
|
}
|
|
|
|
if (bytes < ntohs(packet.ip.tot_len)) {
|
|
/* packet is bigger than sizeof(packet), we did partial read */
|
|
log1("Oversized packet, ignoring");
|
|
return -2;
|
|
}
|
|
|
|
/* ignore any extra garbage bytes */
|
|
bytes = ntohs(packet.ip.tot_len);
|
|
|
|
/* make sure its the right packet for us, and that it passes sanity checks */
|
|
if (packet.ip.protocol != IPPROTO_UDP || packet.ip.version != IPVERSION
|
|
|| packet.ip.ihl != (sizeof(packet.ip) >> 2)
|
|
|| packet.udp.dest != htons(CLIENT_PORT)
|
|
/* || bytes > (int) sizeof(packet) - can't happen */
|
|
|| ntohs(packet.udp.len) != (uint16_t)(bytes - sizeof(packet.ip))
|
|
) {
|
|
log1("Unrelated/bogus packet, ignoring");
|
|
return -2;
|
|
}
|
|
|
|
/* verify IP checksum */
|
|
check = packet.ip.check;
|
|
packet.ip.check = 0;
|
|
if (check != udhcp_checksum(&packet.ip, sizeof(packet.ip))) {
|
|
log1("Bad IP header checksum, ignoring");
|
|
return -2;
|
|
}
|
|
|
|
/* verify UDP checksum. IP header has to be modified for this */
|
|
memset(&packet.ip, 0, offsetof(struct iphdr, protocol));
|
|
/* ip.xx fields which are not memset: protocol, check, saddr, daddr */
|
|
packet.ip.tot_len = packet.udp.len; /* yes, this is needed */
|
|
check = packet.udp.check;
|
|
packet.udp.check = 0;
|
|
if (check && check != udhcp_checksum(&packet, bytes)) {
|
|
log1("Packet with bad UDP checksum received, ignoring");
|
|
return -2;
|
|
}
|
|
|
|
memcpy(dhcp_pkt, &packet.data, bytes - (sizeof(packet.ip) + sizeof(packet.udp)));
|
|
|
|
if (dhcp_pkt->cookie != htonl(DHCP_MAGIC)) {
|
|
bb_info_msg("Packet with bad magic, ignoring");
|
|
return -2;
|
|
}
|
|
log1("Got valid DHCP packet");
|
|
udhcp_dump_packet(dhcp_pkt);
|
|
return bytes - (sizeof(packet.ip) + sizeof(packet.udp));
|
|
}
|
|
|
|
|
|
/*** Main ***/
|
|
|
|
static int sockfd = -1;
|
|
|
|
#define LISTEN_NONE 0
|
|
#define LISTEN_KERNEL 1
|
|
#define LISTEN_RAW 2
|
|
static smallint listen_mode;
|
|
|
|
/* initial state: (re)start DHCP negotiation */
|
|
#define INIT_SELECTING 0
|
|
/* discover was sent, DHCPOFFER reply received */
|
|
#define REQUESTING 1
|
|
/* select/renew was sent, DHCPACK reply received */
|
|
#define BOUND 2
|
|
/* half of lease passed, want to renew it by sending unicast renew requests */
|
|
#define RENEWING 3
|
|
/* renew requests were not answered, lease is almost over, send broadcast renew */
|
|
#define REBINDING 4
|
|
/* manually requested renew (SIGUSR1) */
|
|
#define RENEW_REQUESTED 5
|
|
/* release, possibly manually requested (SIGUSR2) */
|
|
#define RELEASED 6
|
|
static smallint state;
|
|
|
|
static int udhcp_raw_socket(int ifindex)
|
|
{
|
|
int fd;
|
|
struct sockaddr_ll sock;
|
|
|
|
/*
|
|
* Comment:
|
|
*
|
|
* I've selected not to see LL header, so BPF doesn't see it, too.
|
|
* The filter may also pass non-IP and non-ARP packets, but we do
|
|
* a more complete check when receiving the message in userspace.
|
|
*
|
|
* and filter shamelessly stolen from:
|
|
*
|
|
* http://www.flamewarmaster.de/software/dhcpclient/
|
|
*
|
|
* There are a few other interesting ideas on that page (look under
|
|
* "Motivation"). Use of netlink events is most interesting. Think
|
|
* of various network servers listening for events and reconfiguring.
|
|
* That would obsolete sending HUP signals and/or make use of restarts.
|
|
*
|
|
* Copyright: 2006, 2007 Stefan Rompf <sux@loplof.de>.
|
|
* License: GPL v2.
|
|
*
|
|
* TODO: make conditional?
|
|
*/
|
|
#define SERVER_AND_CLIENT_PORTS ((67 << 16) + 68)
|
|
static const struct sock_filter filter_instr[] = {
|
|
/* check for udp */
|
|
BPF_STMT(BPF_LD|BPF_B|BPF_ABS, 9),
|
|
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, IPPROTO_UDP, 2, 0), /* L5, L1, is UDP? */
|
|
/* ugly check for arp on ethernet-like and IPv4 */
|
|
BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2), /* L1: */
|
|
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x08000604, 3, 4), /* L3, L4 */
|
|
/* skip IP header */
|
|
BPF_STMT(BPF_LDX|BPF_B|BPF_MSH, 0), /* L5: */
|
|
/* check udp source and destination ports */
|
|
BPF_STMT(BPF_LD|BPF_W|BPF_IND, 0),
|
|
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, SERVER_AND_CLIENT_PORTS, 0, 1), /* L3, L4 */
|
|
/* returns */
|
|
BPF_STMT(BPF_RET|BPF_K, 0x0fffffff ), /* L3: pass */
|
|
BPF_STMT(BPF_RET|BPF_K, 0), /* L4: reject */
|
|
};
|
|
static const struct sock_fprog filter_prog = {
|
|
.len = sizeof(filter_instr) / sizeof(filter_instr[0]),
|
|
/* casting const away: */
|
|
.filter = (struct sock_filter *) filter_instr,
|
|
};
|
|
|
|
log1("Opening raw socket on ifindex %d", ifindex); //log2?
|
|
|
|
fd = xsocket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP));
|
|
log1("Got raw socket fd %d", fd); //log2?
|
|
|
|
if (SERVER_PORT == 67 && CLIENT_PORT == 68) {
|
|
/* Use only if standard ports are in use */
|
|
/* Ignoring error (kernel may lack support for this) */
|
|
if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter_prog,
|
|
sizeof(filter_prog)) >= 0)
|
|
log1("Attached filter to raw socket fd %d", fd); // log?
|
|
}
|
|
|
|
sock.sll_family = AF_PACKET;
|
|
sock.sll_protocol = htons(ETH_P_IP);
|
|
sock.sll_ifindex = ifindex;
|
|
xbind(fd, (struct sockaddr *) &sock, sizeof(sock));
|
|
log1("Created raw socket");
|
|
|
|
return fd;
|
|
}
|
|
|
|
static void change_listen_mode(int new_mode)
|
|
{
|
|
log1("Entering listen mode: %s",
|
|
new_mode != LISTEN_NONE
|
|
? (new_mode == LISTEN_KERNEL ? "kernel" : "raw")
|
|
: "none"
|
|
);
|
|
|
|
listen_mode = new_mode;
|
|
if (sockfd >= 0) {
|
|
close(sockfd);
|
|
sockfd = -1;
|
|
}
|
|
if (new_mode == LISTEN_KERNEL)
|
|
sockfd = udhcp_listen_socket(/*INADDR_ANY,*/ CLIENT_PORT, client_config.interface);
|
|
else if (new_mode != LISTEN_NONE)
|
|
sockfd = udhcp_raw_socket(client_config.ifindex);
|
|
/* else LISTEN_NONE: sockfd stays closed */
|
|
}
|
|
|
|
static void perform_renew(void)
|
|
{
|
|
bb_info_msg("Performing a DHCP renew");
|
|
switch (state) {
|
|
case BOUND:
|
|
change_listen_mode(LISTEN_KERNEL);
|
|
case RENEWING:
|
|
case REBINDING:
|
|
state = RENEW_REQUESTED;
|
|
break;
|
|
case RENEW_REQUESTED: /* impatient are we? fine, square 1 */
|
|
udhcp_run_script(NULL, "deconfig");
|
|
case REQUESTING:
|
|
case RELEASED:
|
|
change_listen_mode(LISTEN_RAW);
|
|
state = INIT_SELECTING;
|
|
break;
|
|
case INIT_SELECTING:
|
|
break;
|
|
}
|
|
}
|
|
|
|
static void perform_release(uint32_t requested_ip, uint32_t server_addr)
|
|
{
|
|
char buffer[sizeof("255.255.255.255")];
|
|
struct in_addr temp_addr;
|
|
|
|
/* send release packet */
|
|
if (state == BOUND || state == RENEWING || state == REBINDING) {
|
|
temp_addr.s_addr = server_addr;
|
|
strcpy(buffer, inet_ntoa(temp_addr));
|
|
temp_addr.s_addr = requested_ip;
|
|
bb_info_msg("Unicasting a release of %s to %s",
|
|
inet_ntoa(temp_addr), buffer);
|
|
send_release(server_addr, requested_ip); /* unicast */
|
|
udhcp_run_script(NULL, "deconfig");
|
|
}
|
|
bb_info_msg("Entering released state");
|
|
|
|
change_listen_mode(LISTEN_NONE);
|
|
state = RELEASED;
|
|
}
|
|
|
|
static uint8_t* alloc_dhcp_option(int code, const char *str, int extra)
|
|
{
|
|
uint8_t *storage;
|
|
int len = strnlen(str, 255);
|
|
storage = xzalloc(len + extra + OPT_DATA);
|
|
storage[OPT_CODE] = code;
|
|
storage[OPT_LEN] = len + extra;
|
|
memcpy(storage + extra + OPT_DATA, str, len);
|
|
return storage;
|
|
}
|
|
|
|
#if BB_MMU
|
|
static void client_background(void)
|
|
{
|
|
bb_daemonize(0);
|
|
logmode &= ~LOGMODE_STDIO;
|
|
/* rewrite pidfile, as our pid is different now */
|
|
write_pidfile(client_config.pidfile);
|
|
}
|
|
#endif
|
|
|
|
int udhcpc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
|
int udhcpc_main(int argc UNUSED_PARAM, char **argv)
|
|
{
|
|
uint8_t *temp, *message;
|
|
const char *str_c, *str_V, *str_h, *str_F, *str_r;
|
|
IF_FEATURE_UDHCP_PORT(char *str_P;)
|
|
llist_t *list_O = NULL;
|
|
llist_t *list_x = NULL;
|
|
int tryagain_timeout = 20;
|
|
int discover_timeout = 3;
|
|
int discover_retries = 3;
|
|
uint32_t server_addr = server_addr; /* for compiler */
|
|
uint32_t requested_ip = 0;
|
|
uint32_t xid = 0;
|
|
uint32_t lease_seconds = 0; /* can be given as 32-bit quantity */
|
|
int packet_num;
|
|
int timeout; /* must be signed */
|
|
unsigned already_waited_sec;
|
|
unsigned opt;
|
|
int max_fd;
|
|
int retval;
|
|
struct timeval tv;
|
|
struct dhcp_packet packet;
|
|
fd_set rfds;
|
|
|
|
#if ENABLE_LONG_OPTS
|
|
static const char udhcpc_longopts[] ALIGN1 =
|
|
"clientid\0" Required_argument "c"
|
|
"clientid-none\0" No_argument "C"
|
|
"vendorclass\0" Required_argument "V"
|
|
"hostname\0" Required_argument "H"
|
|
"fqdn\0" Required_argument "F"
|
|
"interface\0" Required_argument "i"
|
|
"now\0" No_argument "n"
|
|
"pidfile\0" Required_argument "p"
|
|
"quit\0" No_argument "q"
|
|
"release\0" No_argument "R"
|
|
"request\0" Required_argument "r"
|
|
"script\0" Required_argument "s"
|
|
"timeout\0" Required_argument "T"
|
|
"version\0" No_argument "v"
|
|
"retries\0" Required_argument "t"
|
|
"tryagain\0" Required_argument "A"
|
|
"syslog\0" No_argument "S"
|
|
"request-option\0" Required_argument "O"
|
|
"no-default-options\0" No_argument "o"
|
|
"foreground\0" No_argument "f"
|
|
"background\0" No_argument "b"
|
|
IF_FEATURE_UDHCPC_ARPING("arping\0" No_argument "a")
|
|
IF_FEATURE_UDHCP_PORT("client-port\0" Required_argument "P")
|
|
;
|
|
#endif
|
|
enum {
|
|
OPT_c = 1 << 0,
|
|
OPT_C = 1 << 1,
|
|
OPT_V = 1 << 2,
|
|
OPT_H = 1 << 3,
|
|
OPT_h = 1 << 4,
|
|
OPT_F = 1 << 5,
|
|
OPT_i = 1 << 6,
|
|
OPT_n = 1 << 7,
|
|
OPT_p = 1 << 8,
|
|
OPT_q = 1 << 9,
|
|
OPT_R = 1 << 10,
|
|
OPT_r = 1 << 11,
|
|
OPT_s = 1 << 12,
|
|
OPT_T = 1 << 13,
|
|
OPT_t = 1 << 14,
|
|
OPT_S = 1 << 15,
|
|
OPT_A = 1 << 16,
|
|
OPT_O = 1 << 17,
|
|
OPT_o = 1 << 18,
|
|
OPT_x = 1 << 19,
|
|
OPT_f = 1 << 20,
|
|
/* The rest has variable bit positions, need to be clever */
|
|
OPTBIT_f = 20,
|
|
USE_FOR_MMU( OPTBIT_b,)
|
|
IF_FEATURE_UDHCPC_ARPING(OPTBIT_a,)
|
|
IF_FEATURE_UDHCP_PORT( OPTBIT_P,)
|
|
USE_FOR_MMU( OPT_b = 1 << OPTBIT_b,)
|
|
IF_FEATURE_UDHCPC_ARPING(OPT_a = 1 << OPTBIT_a,)
|
|
IF_FEATURE_UDHCP_PORT( OPT_P = 1 << OPTBIT_P,)
|
|
};
|
|
|
|
/* Default options. */
|
|
IF_FEATURE_UDHCP_PORT(SERVER_PORT = 67;)
|
|
IF_FEATURE_UDHCP_PORT(CLIENT_PORT = 68;)
|
|
client_config.interface = "eth0";
|
|
client_config.script = CONFIG_UDHCPC_DEFAULT_SCRIPT;
|
|
str_V = "udhcp "BB_VER;
|
|
|
|
/* Parse command line */
|
|
/* Cc: mutually exclusive; O,x: list; -T,-t,-A take numeric param */
|
|
opt_complementary = "c--C:C--c:O::x::T+:t+:A+"
|
|
#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
|
|
":vv"
|
|
#endif
|
|
;
|
|
IF_LONG_OPTS(applet_long_options = udhcpc_longopts;)
|
|
opt = getopt32(argv, "c:CV:H:h:F:i:np:qRr:s:T:t:SA:O:ox:f"
|
|
USE_FOR_MMU("b")
|
|
IF_FEATURE_UDHCPC_ARPING("a")
|
|
IF_FEATURE_UDHCP_PORT("P:")
|
|
"v"
|
|
, &str_c, &str_V, &str_h, &str_h, &str_F
|
|
, &client_config.interface, &client_config.pidfile, &str_r /* i,p */
|
|
, &client_config.script /* s */
|
|
, &discover_timeout, &discover_retries, &tryagain_timeout /* T,t,A */
|
|
, &list_O
|
|
, &list_x
|
|
IF_FEATURE_UDHCP_PORT(, &str_P)
|
|
#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
|
|
, &dhcp_verbose
|
|
#endif
|
|
);
|
|
if (opt & (OPT_h|OPT_H))
|
|
client_config.hostname = alloc_dhcp_option(DHCP_HOST_NAME, str_h, 0);
|
|
if (opt & OPT_F) {
|
|
/* FQDN option format: [0x51][len][flags][0][0]<fqdn> */
|
|
client_config.fqdn = alloc_dhcp_option(DHCP_FQDN, str_F, 3);
|
|
/* Flag bits: 0000NEOS
|
|
* S: 1 = Client requests server to update A RR in DNS as well as PTR
|
|
* O: 1 = Server indicates to client that DNS has been updated regardless
|
|
* E: 1 = Name is in DNS format, i.e. <4>host<6>domain<3>com<0>,
|
|
* not "host.domain.com". Format 0 is obsolete.
|
|
* N: 1 = Client requests server to not update DNS (S must be 0 then)
|
|
* Two [0] bytes which follow are deprecated and must be 0.
|
|
*/
|
|
client_config.fqdn[OPT_DATA + 0] = 0x1;
|
|
/*client_config.fqdn[OPT_DATA + 1] = 0; - xzalloc did it */
|
|
/*client_config.fqdn[OPT_DATA + 2] = 0; */
|
|
}
|
|
if (opt & OPT_r)
|
|
requested_ip = inet_addr(str_r);
|
|
#if ENABLE_FEATURE_UDHCP_PORT
|
|
if (opt & OPT_P) {
|
|
CLIENT_PORT = xatou16(str_P);
|
|
SERVER_PORT = CLIENT_PORT - 1;
|
|
}
|
|
#endif
|
|
if (opt & OPT_o)
|
|
client_config.no_default_options = 1;
|
|
while (list_O) {
|
|
char *optstr = llist_pop(&list_O);
|
|
unsigned n = udhcp_option_idx(optstr);
|
|
n = dhcp_optflags[n].code;
|
|
client_config.opt_mask[n >> 3] |= 1 << (n & 7);
|
|
}
|
|
while (list_x) {
|
|
char *optstr = llist_pop(&list_x);
|
|
char *colon = strchr(optstr, ':');
|
|
if (colon)
|
|
*colon = ' ';
|
|
/* now it looks similar to udhcpd's config file line:
|
|
* "optname optval", using the common routine: */
|
|
udhcp_str2optset(optstr, &client_config.options);
|
|
}
|
|
|
|
if (udhcp_read_interface(client_config.interface,
|
|
&client_config.ifindex,
|
|
NULL,
|
|
client_config.client_mac)
|
|
) {
|
|
return 1;
|
|
}
|
|
|
|
if (opt & OPT_c) {
|
|
client_config.clientid = alloc_dhcp_option(DHCP_CLIENT_ID, str_c, 0);
|
|
} else if (!(opt & OPT_C)) {
|
|
/* not set and not suppressed, set the default client ID */
|
|
client_config.clientid = alloc_dhcp_option(DHCP_CLIENT_ID, "", 7);
|
|
client_config.clientid[OPT_DATA] = 1; /* type: ethernet */
|
|
memcpy(client_config.clientid + OPT_DATA+1, client_config.client_mac, 6);
|
|
}
|
|
if (str_V[0] != '\0')
|
|
client_config.vendorclass = alloc_dhcp_option(DHCP_VENDOR, str_V, 0);
|
|
#if !BB_MMU
|
|
/* on NOMMU reexec (i.e., background) early */
|
|
if (!(opt & OPT_f)) {
|
|
bb_daemonize_or_rexec(0 /* flags */, argv);
|
|
logmode = LOGMODE_NONE;
|
|
}
|
|
#endif
|
|
if (opt & OPT_S) {
|
|
openlog(applet_name, LOG_PID, LOG_DAEMON);
|
|
logmode |= LOGMODE_SYSLOG;
|
|
}
|
|
|
|
/* Make sure fd 0,1,2 are open */
|
|
bb_sanitize_stdio();
|
|
/* Equivalent of doing a fflush after every \n */
|
|
setlinebuf(stdout);
|
|
/* Create pidfile */
|
|
write_pidfile(client_config.pidfile);
|
|
/* Goes to stdout (unless NOMMU) and possibly syslog */
|
|
bb_info_msg("%s (v"BB_VER") started", applet_name);
|
|
/* Set up the signal pipe */
|
|
udhcp_sp_setup();
|
|
/* We want random_xid to be random... */
|
|
srand(monotonic_us());
|
|
|
|
state = INIT_SELECTING;
|
|
udhcp_run_script(NULL, "deconfig");
|
|
change_listen_mode(LISTEN_RAW);
|
|
packet_num = 0;
|
|
timeout = 0;
|
|
already_waited_sec = 0;
|
|
|
|
/* Main event loop. select() waits on signal pipe and possibly
|
|
* on sockfd.
|
|
* "continue" statements in code below jump to the top of the loop.
|
|
*/
|
|
for (;;) {
|
|
/* silence "uninitialized!" warning */
|
|
unsigned timestamp_before_wait = timestamp_before_wait;
|
|
|
|
//bb_error_msg("sockfd:%d, listen_mode:%d", sockfd, listen_mode);
|
|
|
|
/* Was opening raw or udp socket here
|
|
* if (listen_mode != LISTEN_NONE && sockfd < 0),
|
|
* but on fast network renew responses return faster
|
|
* than we open sockets. Thus this code is moved
|
|
* to change_listen_mode(). Thus we open listen socket
|
|
* BEFORE we send renew request (see "case BOUND:"). */
|
|
|
|
max_fd = udhcp_sp_fd_set(&rfds, sockfd);
|
|
|
|
tv.tv_sec = timeout - already_waited_sec;
|
|
tv.tv_usec = 0;
|
|
retval = 0;
|
|
/* If we already timed out, fall through with retval = 0, else... */
|
|
if ((int)tv.tv_sec > 0) {
|
|
timestamp_before_wait = (unsigned)monotonic_sec();
|
|
log1("Waiting on select...");
|
|
retval = select(max_fd + 1, &rfds, NULL, NULL, &tv);
|
|
if (retval < 0) {
|
|
/* EINTR? A signal was caught, don't panic */
|
|
if (errno == EINTR) {
|
|
already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait;
|
|
continue;
|
|
}
|
|
/* Else: an error occured, panic! */
|
|
bb_perror_msg_and_die("select");
|
|
}
|
|
}
|
|
|
|
/* If timeout dropped to zero, time to become active:
|
|
* resend discover/renew/whatever
|
|
*/
|
|
if (retval == 0) {
|
|
/* We will restart the wait in any case */
|
|
already_waited_sec = 0;
|
|
|
|
switch (state) {
|
|
case INIT_SELECTING:
|
|
if (packet_num < discover_retries) {
|
|
if (packet_num == 0)
|
|
xid = random_xid();
|
|
/* broadcast */
|
|
send_discover(xid, requested_ip);
|
|
timeout = discover_timeout;
|
|
packet_num++;
|
|
continue;
|
|
}
|
|
leasefail:
|
|
udhcp_run_script(NULL, "leasefail");
|
|
#if BB_MMU /* -b is not supported on NOMMU */
|
|
if (opt & OPT_b) { /* background if no lease */
|
|
bb_info_msg("No lease, forking to background");
|
|
client_background();
|
|
/* do not background again! */
|
|
opt = ((opt & ~OPT_b) | OPT_f);
|
|
} else
|
|
#endif
|
|
if (opt & OPT_n) { /* abort if no lease */
|
|
bb_info_msg("No lease, failing");
|
|
retval = 1;
|
|
goto ret;
|
|
}
|
|
/* wait before trying again */
|
|
timeout = tryagain_timeout;
|
|
packet_num = 0;
|
|
continue;
|
|
case REQUESTING:
|
|
if (packet_num < discover_retries) {
|
|
/* send broadcast select packet */
|
|
send_select(xid, server_addr, requested_ip);
|
|
timeout = discover_timeout;
|
|
packet_num++;
|
|
continue;
|
|
}
|
|
/* Timed out, go back to init state.
|
|
* "discover...select...discover..." loops
|
|
* were seen in the wild. Treat them similarly
|
|
* to "no response to discover" case */
|
|
change_listen_mode(LISTEN_RAW);
|
|
state = INIT_SELECTING;
|
|
goto leasefail;
|
|
case BOUND:
|
|
/* 1/2 lease passed, enter renewing state */
|
|
state = RENEWING;
|
|
change_listen_mode(LISTEN_KERNEL);
|
|
log1("Entering renew state");
|
|
/* fall right through */
|
|
case RENEW_REQUESTED: /* manual (SIGUSR1) renew */
|
|
case_RENEW_REQUESTED:
|
|
case RENEWING:
|
|
if (timeout > 60) {
|
|
/* send an unicast renew request */
|
|
/* Sometimes observed to fail (EADDRNOTAVAIL) to bind
|
|
* a new UDP socket for sending inside send_renew.
|
|
* I hazard to guess existing listening socket
|
|
* is somehow conflicting with it, but why is it
|
|
* not deterministic then?! Strange.
|
|
* Anyway, it does recover by eventually failing through
|
|
* into INIT_SELECTING state.
|
|
*/
|
|
send_renew(xid, server_addr, requested_ip);
|
|
timeout >>= 1;
|
|
continue;
|
|
}
|
|
/* Timed out, enter rebinding state */
|
|
log1("Entering rebinding state");
|
|
state = REBINDING;
|
|
/* fall right through */
|
|
case REBINDING:
|
|
/* Switch to bcast receive */
|
|
change_listen_mode(LISTEN_RAW);
|
|
/* Lease is *really* about to run out,
|
|
* try to find DHCP server using broadcast */
|
|
if (timeout > 0) {
|
|
/* send a broadcast renew request */
|
|
send_renew(xid, 0 /*INADDR_ANY*/, requested_ip);
|
|
timeout >>= 1;
|
|
continue;
|
|
}
|
|
/* Timed out, enter init state */
|
|
bb_info_msg("Lease lost, entering init state");
|
|
udhcp_run_script(NULL, "deconfig");
|
|
state = INIT_SELECTING;
|
|
/*timeout = 0; - already is */
|
|
packet_num = 0;
|
|
continue;
|
|
/* case RELEASED: */
|
|
}
|
|
/* yah, I know, *you* say it would never happen */
|
|
timeout = INT_MAX;
|
|
continue; /* back to main loop */
|
|
} /* if select timed out */
|
|
|
|
/* select() didn't timeout, something happened */
|
|
|
|
/* Is it a signal? */
|
|
/* note: udhcp_sp_read checks FD_ISSET before reading */
|
|
switch (udhcp_sp_read(&rfds)) {
|
|
case SIGUSR1:
|
|
perform_renew();
|
|
if (state == RENEW_REQUESTED)
|
|
goto case_RENEW_REQUESTED;
|
|
/* Start things over */
|
|
packet_num = 0;
|
|
/* Kill any timeouts, user wants this to hurry along */
|
|
timeout = 0;
|
|
continue;
|
|
case SIGUSR2:
|
|
perform_release(requested_ip, server_addr);
|
|
timeout = INT_MAX;
|
|
continue;
|
|
case SIGTERM:
|
|
bb_info_msg("Received SIGTERM");
|
|
if (opt & OPT_R) /* release on quit */
|
|
perform_release(requested_ip, server_addr);
|
|
goto ret0;
|
|
}
|
|
|
|
/* Is it a packet? */
|
|
if (listen_mode == LISTEN_NONE || !FD_ISSET(sockfd, &rfds))
|
|
continue; /* no */
|
|
|
|
{
|
|
int len;
|
|
|
|
/* A packet is ready, read it */
|
|
if (listen_mode == LISTEN_KERNEL)
|
|
len = udhcp_recv_kernel_packet(&packet, sockfd);
|
|
else
|
|
len = udhcp_recv_raw_packet(&packet, sockfd);
|
|
if (len == -1) {
|
|
/* Error is severe, reopen socket */
|
|
bb_info_msg("Read error: %s, reopening socket", strerror(errno));
|
|
sleep(discover_timeout); /* 3 seconds by default */
|
|
change_listen_mode(listen_mode); /* just close and reopen */
|
|
}
|
|
/* If this packet will turn out to be unrelated/bogus,
|
|
* we will go back and wait for next one.
|
|
* Be sure timeout is properly decreased. */
|
|
already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait;
|
|
if (len < 0)
|
|
continue;
|
|
}
|
|
|
|
if (packet.xid != xid) {
|
|
log1("xid %x (our is %x), ignoring packet",
|
|
(unsigned)packet.xid, (unsigned)xid);
|
|
continue;
|
|
}
|
|
|
|
/* Ignore packets that aren't for us */
|
|
if (packet.hlen != 6
|
|
|| memcmp(packet.chaddr, client_config.client_mac, 6)
|
|
) {
|
|
//FIXME: need to also check that last 10 bytes are zero
|
|
log1("chaddr does not match, ignoring packet"); // log2?
|
|
continue;
|
|
}
|
|
|
|
message = udhcp_get_option(&packet, DHCP_MESSAGE_TYPE);
|
|
if (message == NULL) {
|
|
bb_error_msg("no message type option, ignoring packet");
|
|
continue;
|
|
}
|
|
|
|
switch (state) {
|
|
case INIT_SELECTING:
|
|
/* Must be a DHCPOFFER to one of our xid's */
|
|
if (*message == DHCPOFFER) {
|
|
/* TODO: why we don't just fetch server's IP from IP header? */
|
|
temp = udhcp_get_option(&packet, DHCP_SERVER_ID);
|
|
if (!temp) {
|
|
bb_error_msg("no server ID in message");
|
|
continue;
|
|
/* still selecting - this server looks bad */
|
|
}
|
|
/* it IS unaligned sometimes, don't "optimize" */
|
|
move_from_unaligned32(server_addr, temp);
|
|
xid = packet.xid;
|
|
requested_ip = packet.yiaddr;
|
|
|
|
/* enter requesting state */
|
|
state = REQUESTING;
|
|
timeout = 0;
|
|
packet_num = 0;
|
|
already_waited_sec = 0;
|
|
}
|
|
continue;
|
|
case REQUESTING:
|
|
case RENEWING:
|
|
case RENEW_REQUESTED:
|
|
case REBINDING:
|
|
if (*message == DHCPACK) {
|
|
temp = udhcp_get_option(&packet, DHCP_LEASE_TIME);
|
|
if (!temp) {
|
|
bb_error_msg("no lease time with ACK, using 1 hour lease");
|
|
lease_seconds = 60 * 60;
|
|
} else {
|
|
/* it IS unaligned sometimes, don't "optimize" */
|
|
move_from_unaligned32(lease_seconds, temp);
|
|
lease_seconds = ntohl(lease_seconds);
|
|
lease_seconds &= 0x0fffffff; /* paranoia: must not be prone to overflows */
|
|
if (lease_seconds < 10) /* and not too small */
|
|
lease_seconds = 10;
|
|
}
|
|
#if ENABLE_FEATURE_UDHCPC_ARPING
|
|
if (opt & OPT_a) {
|
|
/* RFC 2131 3.1 paragraph 5:
|
|
* "The client receives the DHCPACK message with configuration
|
|
* parameters. The client SHOULD perform a final check on the
|
|
* parameters (e.g., ARP for allocated network address), and notes
|
|
* the duration of the lease specified in the DHCPACK message. At this
|
|
* point, the client is configured. If the client detects that the
|
|
* address is already in use (e.g., through the use of ARP),
|
|
* the client MUST send a DHCPDECLINE message to the server and restarts
|
|
* the configuration process..." */
|
|
if (!arpping(packet.yiaddr,
|
|
NULL,
|
|
(uint32_t) 0,
|
|
client_config.client_mac,
|
|
client_config.interface)
|
|
) {
|
|
bb_info_msg("Offered address is in use "
|
|
"(got ARP reply), declining");
|
|
send_decline(xid, server_addr, packet.yiaddr);
|
|
|
|
if (state != REQUESTING)
|
|
udhcp_run_script(NULL, "deconfig");
|
|
change_listen_mode(LISTEN_RAW);
|
|
state = INIT_SELECTING;
|
|
requested_ip = 0;
|
|
timeout = tryagain_timeout;
|
|
packet_num = 0;
|
|
already_waited_sec = 0;
|
|
continue; /* back to main loop */
|
|
}
|
|
}
|
|
#endif
|
|
/* enter bound state */
|
|
timeout = lease_seconds / 2;
|
|
{
|
|
struct in_addr temp_addr;
|
|
temp_addr.s_addr = packet.yiaddr;
|
|
bb_info_msg("Lease of %s obtained, lease time %u",
|
|
inet_ntoa(temp_addr), (unsigned)lease_seconds);
|
|
}
|
|
requested_ip = packet.yiaddr;
|
|
udhcp_run_script(&packet, state == REQUESTING ? "bound" : "renew");
|
|
|
|
state = BOUND;
|
|
change_listen_mode(LISTEN_NONE);
|
|
if (opt & OPT_q) { /* quit after lease */
|
|
if (opt & OPT_R) /* release on quit */
|
|
perform_release(requested_ip, server_addr);
|
|
goto ret0;
|
|
}
|
|
/* future renew failures should not exit (JM) */
|
|
opt &= ~OPT_n;
|
|
#if BB_MMU /* NOMMU case backgrounded earlier */
|
|
if (!(opt & OPT_f)) {
|
|
client_background();
|
|
/* do not background again! */
|
|
opt = ((opt & ~OPT_b) | OPT_f);
|
|
}
|
|
#endif
|
|
already_waited_sec = 0;
|
|
continue; /* back to main loop */
|
|
}
|
|
if (*message == DHCPNAK) {
|
|
/* return to init state */
|
|
bb_info_msg("Received DHCP NAK");
|
|
udhcp_run_script(&packet, "nak");
|
|
if (state != REQUESTING)
|
|
udhcp_run_script(NULL, "deconfig");
|
|
change_listen_mode(LISTEN_RAW);
|
|
sleep(3); /* avoid excessive network traffic */
|
|
state = INIT_SELECTING;
|
|
requested_ip = 0;
|
|
timeout = 0;
|
|
packet_num = 0;
|
|
already_waited_sec = 0;
|
|
}
|
|
continue;
|
|
/* case BOUND: - ignore all packets */
|
|
/* case RELEASED: - ignore all packets */
|
|
}
|
|
/* back to main loop */
|
|
} /* for (;;) - main loop ends */
|
|
|
|
ret0:
|
|
retval = 0;
|
|
ret:
|
|
/*if (client_config.pidfile) - remove_pidfile has its own check */
|
|
remove_pidfile(client_config.pidfile);
|
|
return retval;
|
|
}
|