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dnsmasq v2.69test3
[tomato.git] / release / src / router / busybox / networking / udhcp / dhcpc.c
blobbb06d02081ca5abfd5c7a8cedcfefde2e0db3ca0
1 /* vi: set sw=4 ts=4: */
2 /*
3 * udhcp client
4 *
5 * Russ Dill <Russ.Dill@asu.edu> July 2001
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21 #include <syslog.h>
22 /* Override ENABLE_FEATURE_PIDFILE - ifupdown needs our pidfile to always exist */
23 #define WANT_PIDFILE 1
24 #include "common.h"
25 #include "dhcpd.h"
26 #include "dhcpc.h"
27
28 #include <asm/types.h>
29 /*#if (defined(__GLIBC__) && __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 1) || defined(_NEWLIB_VERSION)
30 # include <linux/if_packet.h>
31 # include <netinet/if_ether.h>
32 #else */
33 # include <linux/if_packet.h>
34 # include <linux/if_ether.h>
35 /*#endif*/
36 #include <linux/filter.h>
37
38 /* "struct client_config_t client_config" is in bb_common_bufsiz1 */
39
40 #if ENABLE_LONG_OPTS
41 static const char udhcpc_longopts[] ALIGN1 =
42 "clientid-none\0" No_argument "C"
43 "vendorclass\0" Required_argument "V"
44 "hostname\0" Required_argument "H"
45 "fqdn\0" Required_argument "F"
46 "interface\0" Required_argument "i"
47 "now\0" No_argument "n"
48 "pidfile\0" Required_argument "p"
49 "quit\0" No_argument "q"
50 "release\0" No_argument "R"
51 "request\0" Required_argument "r"
52 "script\0" Required_argument "s"
53 "timeout\0" Required_argument "T"
54 "version\0" No_argument "v"
55 "retries\0" Required_argument "t"
56 "tryagain\0" Required_argument "A"
57 "syslog\0" No_argument "S"
58 "request-option\0" Required_argument "O"
59 "no-default-options\0" No_argument "o"
60 "foreground\0" No_argument "f"
61 "background\0" No_argument "b"
62 "broadcast\0" No_argument "B"
63 IF_FEATURE_UDHCPC_ARPING("arping\0" No_argument "a")
64 IF_FEATURE_UDHCP_PORT("client-port\0" Required_argument "P")
65 ;
66 #endif
67 /* Must match getopt32 option string order */
68 enum {
69 OPT_C = 1 << 0,
70 OPT_V = 1 << 1,
71 OPT_H = 1 << 2,
72 OPT_h = 1 << 3,
73 OPT_F = 1 << 4,
74 OPT_i = 1 << 5,
75 OPT_n = 1 << 6,
76 OPT_p = 1 << 7,
77 OPT_q = 1 << 8,
78 OPT_R = 1 << 9,
79 OPT_r = 1 << 10,
80 OPT_s = 1 << 11,
81 OPT_T = 1 << 12,
82 OPT_t = 1 << 13,
83 OPT_S = 1 << 14,
84 OPT_A = 1 << 15,
85 OPT_O = 1 << 16,
86 OPT_o = 1 << 17,
87 OPT_x = 1 << 18,
88 OPT_f = 1 << 19,
89 OPT_B = 1 << 20,
90 OPT_m = 1 << 21, // zzz
91 /* The rest has variable bit positions, need to be clever */
92 OPTBIT_LAST = 21,
93 USE_FOR_MMU( OPTBIT_b,)
94 IF_FEATURE_UDHCPC_ARPING(OPTBIT_a,)
95 IF_FEATURE_UDHCP_PORT( OPTBIT_P,)
96 USE_FOR_MMU( OPT_b = 1 << OPTBIT_b,)
97 IF_FEATURE_UDHCPC_ARPING(OPT_a = 1 << OPTBIT_a,)
98 IF_FEATURE_UDHCP_PORT( OPT_P = 1 << OPTBIT_P,)
99 };
100
101
102 /*** Script execution code ***/
103
104 /* get a rough idea of how long an option will be (rounding up...) */
105 static const uint8_t len_of_option_as_string[] = {
106 [OPTION_IP ] = sizeof("255.255.255.255 "),
107 [OPTION_IP_PAIR ] = sizeof("255.255.255.255 ") * 2,
108 [OPTION_STATIC_ROUTES ] = sizeof("255.255.255.255/32 255.255.255.255 "),
109 [OPTION_6RD ] = sizeof("32 128 FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF 255.255.255.255 "),
110 [OPTION_STRING ] = 1,
111 [OPTION_STRING_HOST ] = 1,
112 #if ENABLE_FEATURE_UDHCP_RFC3397
113 [OPTION_DNS_STRING ] = 1, /* unused */
114 /* Hmmm, this severely overestimates size if SIP_SERVERS option
115 * is in domain name form: N-byte option in binary form
116 * mallocs ~16*N bytes. But it is freed almost at once.
117 */
118 [OPTION_SIP_SERVERS ] = sizeof("255.255.255.255 "),
119 #endif
120 // [OPTION_BOOLEAN ] = sizeof("yes "),
121 [OPTION_U8 ] = sizeof("255 "),
122 [OPTION_U16 ] = sizeof("65535 "),
123 // [OPTION_S16 ] = sizeof("-32768 "),
124 [OPTION_U32 ] = sizeof("4294967295 "),
125 [OPTION_S32 ] = sizeof("-2147483684 "),
126 };
127
128 /* note: ip is a pointer to an IP in network order, possibly misaliged */
129 static int sprint_nip(char *dest, const char *pre, const uint8_t *ip)
130 {
131 return sprintf(dest, "%s%u.%u.%u.%u", pre, ip[0], ip[1], ip[2], ip[3]);
132 }
133
134 /* really simple implementation, just count the bits */
135 static int mton(uint32_t mask)
136 {
137 int i = 0;
138 mask = ntohl(mask); /* 111110000-like bit pattern */
139 while (mask) {
140 i++;
141 mask <<= 1;
142 }
143 return i;
144 }
145
146 /* Check if a given label represents a valid DNS label
147 * Return pointer to the first character after the label upon success,
148 * NULL otherwise.
149 * See RFC1035, 2.3.1
150 */
151 /* We don't need to be particularly anal. For example, allowing _, hyphen
152 * at the end, or leading and trailing dots would be ok, since it
153 * can't be used for attacks. (Leading hyphen can be, if someone uses
154 * cmd "$hostname"
155 * in the script: then hostname may be treated as an option)
156 */
157 static const char *valid_domain_label(const char *label)
158 {
159 unsigned char ch;
160 unsigned pos = 0;
161
162 for (;;) {
163 ch = *label;
164 if ((ch|0x20) < 'a' || (ch|0x20) > 'z') {
165 if (pos == 0) {
166 /* label must begin with letter */
167 return NULL;
168 }
169 if (ch < '0' || ch > '9') {
170 if (ch == '\0' || ch == '.')
171 return label;
172 /* DNS allows only '-', but we are more permissive */
173 if (ch != '-' && ch != '_')
174 return NULL;
175 }
176 }
177 label++;
178 pos++;
179 //Do we want this?
180 //if (pos > 63) /* NS_MAXLABEL; labels must be 63 chars or less */
181 // return NULL;
182 }
183 }
184
185 /* Check if a given name represents a valid DNS name */
186 /* See RFC1035, 2.3.1 */
187 static int good_hostname(const char *name)
188 {
189 //const char *start = name;
190
191 for (;;) {
192 name = valid_domain_label(name);
193 if (!name)
194 return 0;
195 if (!name[0])
196 return 1;
197 //Do we want this?
198 //return ((name - start) < 1025); /* NS_MAXDNAME */
199 name++;
200 }
201 }
202
203 /* Create "opt_name=opt_value" string */
204 static NOINLINE char *xmalloc_optname_optval(uint8_t *option, const struct dhcp_optflag *optflag, const char *opt_name)
205 {
206 unsigned upper_length;
207 int len, type, optlen;
208 char *dest, *ret;
209
210 /* option points to OPT_DATA, need to go back to get OPT_LEN */
211 len = option[-OPT_DATA + OPT_LEN];
212
213 type = optflag->flags & OPTION_TYPE_MASK;
214 optlen = dhcp_option_lengths[type];
215 upper_length = len_of_option_as_string[type]
216 * ((unsigned)(len + optlen - 1) / (unsigned)optlen);
217
218 dest = ret = xmalloc(upper_length + strlen(opt_name) + 2);
219 dest += sprintf(ret, "%s=", opt_name);
220
221 while (len >= optlen) {
222 switch (type) {
223 case OPTION_IP:
224 case OPTION_IP_PAIR:
225 dest += sprint_nip(dest, "", option);
226 if (type == OPTION_IP)
227 break;
228 dest += sprint_nip(dest, "/", option + 4);
229 break;
230 // case OPTION_BOOLEAN:
231 // dest += sprintf(dest, *option ? "yes" : "no");
232 // break;
233 case OPTION_U8:
234 dest += sprintf(dest, "%u", *option);
235 break;
236 // case OPTION_S16:
237 case OPTION_U16: {
238 uint16_t val_u16;
239 move_from_unaligned16(val_u16, option);
240 dest += sprintf(dest, "%u", ntohs(val_u16));
241 break;
242 }
243 case OPTION_S32:
244 case OPTION_U32: {
245 uint32_t val_u32;
246 move_from_unaligned32(val_u32, option);
247 dest += sprintf(dest, type == OPTION_U32 ? "%lu" : "%ld", (unsigned long) ntohl(val_u32));
248 break;
249 }
250 /* Note: options which use 'return' instead of 'break'
251 * (for example, OPTION_STRING) skip the code which handles
252 * the case of list of options.
253 */
254 case OPTION_STRING:
255 case OPTION_STRING_HOST:
256 memcpy(dest, option, len);
257 dest[len] = '\0';
258 if (type == OPTION_STRING_HOST && !good_hostname(dest))
259 safe_strncpy(dest, "bad", len);
260 return ret;
261 case OPTION_STATIC_ROUTES: {
262 /* Option binary format:
263 * mask [one byte, 0..32]
264 * ip [big endian, 0..4 bytes depending on mask]
265 * router [big endian, 4 bytes]
266 * may be repeated
267 *
268 * We convert it to a string "IP/MASK ROUTER IP2/MASK2 ROUTER2"
269 */
270 const char *pfx = "";
271
272 while (len >= 1 + 4) { /* mask + 0-byte ip + router */
273 uint32_t nip;
274 uint8_t *p;
275 unsigned mask;
276 int bytes;
277
278 mask = *option++;
279 if (mask > 32)
280 break;
281 len--;
282
283 nip = 0;
284 p = (void*) &nip;
285 bytes = (mask + 7) / 8; /* 0 -> 0, 1..8 -> 1, 9..16 -> 2 etc */
286 while (--bytes >= 0) {
287 *p++ = *option++;
288 len--;
289 }
290 if (len < 4)
291 break;
292
293 /* print ip/mask */
294 dest += sprint_nip(dest, pfx, (void*) &nip);
295 pfx = " ";
296 dest += sprintf(dest, "/%u ", mask);
297 /* print router */
298 dest += sprint_nip(dest, "", option);
299 option += 4;
300 len -= 4;
301 }
302
303 return ret;
304 }
305 case OPTION_6RD:
306 /* Option binary format (see RFC 5969):
307 * 0 1 2 3
308 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
309 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
310 * | OPTION_6RD | option-length | IPv4MaskLen | 6rdPrefixLen |
311 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
312 * | 6rdPrefix |
313 * ... (16 octets) ...
314 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
315 * ... 6rdBRIPv4Address(es) ...
316 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
317 * We convert it to a string
318 * "IPv4MaskLen 6rdPrefixLen 6rdPrefix 6rdBRIPv4Address..."
319 *
320 * Sanity check: ensure that our length is at least 22 bytes, that
321 * IPv4MaskLen <= 32,
322 * 6rdPrefixLen <= 128,
323 * 6rdPrefixLen + (32 - IPv4MaskLen) <= 128
324 * (2nd condition need no check - it follows from 1st and 3rd).
325 * Else, return envvar with empty value ("optname=")
326 */
327 if (len >= (1 + 1 + 16 + 4)
328 && option[0] <= 32
329 && (option[1] + 32 - option[0]) <= 128
330 ) {
331 /* IPv4MaskLen */
332 dest += sprintf(dest, "%u ", *option++);
333 /* 6rdPrefixLen */
334 dest += sprintf(dest, "%u ", *option++);
335 /* 6rdPrefix */
336 dest += sprint_nip6(dest, /* "", */ option);
337 option += 16;
338 len -= 1 + 1 + 16 + 4;
339 /* "+ 4" above corresponds to the length of IPv4 addr
340 * we consume in the loop below */
341 while (1) {
342 /* 6rdBRIPv4Address(es) */
343 dest += sprint_nip(dest, " ", option);
344 option += 4;
345 len -= 4; /* do we have yet another 4+ bytes? */
346 if (len < 0)
347 break; /* no */
348 }
349 }
350
351 return ret;
352 #if ENABLE_FEATURE_UDHCP_RFC3397
353 case OPTION_DNS_STRING:
354 /* unpack option into dest; use ret for prefix (i.e., "optname=") */
355 dest = dname_dec(option, len, ret);
356 if (dest) {
357 free(ret);
358 return dest;
359 }
360 /* error. return "optname=" string */
361 return ret;
362 case OPTION_SIP_SERVERS:
363 /* Option binary format:
364 * type: byte
365 * type=0: domain names, dns-compressed
366 * type=1: IP addrs
367 */
368 option++;
369 len--;
370 if (option[-1] == 0) {
371 dest = dname_dec(option, len, ret);
372 if (dest) {
373 free(ret);
374 return dest;
375 }
376 } else
377 if (option[-1] == 1) {
378 const char *pfx = "";
379 while (1) {
380 len -= 4;
381 if (len < 0)
382 break;
383 dest += sprint_nip(dest, pfx, option);
384 pfx = " ";
385 option += 4;
386 }
387 }
388 return ret;
389 #endif
390 } /* switch */
391
392 /* If we are here, try to format any remaining data
393 * in the option as another, similarly-formatted option
394 */
395 option += optlen;
396 len -= optlen;
397 // TODO: it can be a list only if (optflag->flags & OPTION_LIST).
398 // Should we bail out/warn if we see multi-ip option which is
399 // not allowed to be such (for example, DHCP_BROADCAST)? -
400 if (len < optlen /* || !(optflag->flags & OPTION_LIST) */)
401 break;
402 *dest++ = ' ';
403 *dest = '\0';
404 } /* while */
405
406 return ret;
407 }
408
409 /* put all the parameters into the environment */
410 static char **fill_envp(struct dhcp_packet *packet)
411 {
412 int envc;
413 int i;
414 char **envp, **curr;
415 const char *opt_name;
416 uint8_t *temp;
417 uint8_t overload = 0;
418
419 #define BITMAP unsigned
420 #define BBITS (sizeof(BITMAP) * 8)
421 #define BMASK(i) (1 << (i & (sizeof(BITMAP) * 8 - 1)))
422 #define FOUND_OPTS(i) (found_opts[(unsigned)i / BBITS])
423 BITMAP found_opts[256 / BBITS];
424
425 memset(found_opts, 0, sizeof(found_opts));
426
427 /* We need 6 elements for:
428 * "interface=IFACE"
429 * "ip=N.N.N.N" from packet->yiaddr
430 * "siaddr=IP" from packet->siaddr_nip (unless 0)
431 * "boot_file=FILE" from packet->file (unless overloaded)
432 * "sname=SERVER_HOSTNAME" from packet->sname (unless overloaded)
433 * terminating NULL
434 */
435 envc = 6;
436 /* +1 element for each option, +2 for subnet option: */
437 if (packet) {
438 /* note: do not search for "pad" (0) and "end" (255) options */
439 //TODO: change logic to scan packet _once_
440 for (i = 1; i < 255; i++) {
441 temp = udhcp_get_option(packet, i);
442 if (temp) {
443 if (i == DHCP_OPTION_OVERLOAD)
444 overload = *temp;
445 else if (i == DHCP_SUBNET)
446 envc++; /* for $mask */
447 envc++;
448 /*if (i != DHCP_MESSAGE_TYPE)*/
449 FOUND_OPTS(i) |= BMASK(i);
450 }
451 }
452 }
453 curr = envp = xzalloc(sizeof(envp[0]) * envc);
454
455 *curr = xasprintf("interface=%s", client_config.interface);
456 putenv(*curr++);
457
458 if (!packet)
459 return envp;
460
461 /* Export BOOTP fields. Fields we don't (yet?) export:
462 * uint8_t op; // always BOOTREPLY
463 * uint8_t htype; // hardware address type. 1 = 10mb ethernet
464 * uint8_t hlen; // hardware address length
465 * uint8_t hops; // used by relay agents only
466 * uint32_t xid;
467 * uint16_t secs; // elapsed since client began acquisition/renewal
468 * uint16_t flags; // only one flag so far: bcast. Never set by server
469 * uint32_t ciaddr; // client IP (usually == yiaddr. can it be different
470 * // if during renew server wants to give us differn IP?)
471 * uint32_t gateway_nip; // relay agent IP address
472 * uint8_t chaddr[16]; // link-layer client hardware address (MAC)
473 * TODO: export gateway_nip as $giaddr?
474 */
475 /* Most important one: yiaddr as $ip */
476 *curr = xmalloc(sizeof("ip=255.255.255.255"));
477 sprint_nip(*curr, "ip=", (uint8_t *) &packet->yiaddr);
478 putenv(*curr++);
479 if (packet->siaddr_nip) {
480 /* IP address of next server to use in bootstrap */
481 *curr = xmalloc(sizeof("siaddr=255.255.255.255"));
482 sprint_nip(*curr, "siaddr=", (uint8_t *) &packet->siaddr_nip);
483 putenv(*curr++);
484 }
485 if (!(overload & FILE_FIELD) && packet->file[0]) {
486 /* watch out for invalid packets */
487 *curr = xasprintf("boot_file=%."DHCP_PKT_FILE_LEN_STR"s", packet->file);
488 putenv(*curr++);
489 }
490 if (!(overload & SNAME_FIELD) && packet->sname[0]) {
491 /* watch out for invalid packets */
492 *curr = xasprintf("sname=%."DHCP_PKT_SNAME_LEN_STR"s", packet->sname);
493 putenv(*curr++);
494 }
495
496 /* Export known DHCP options */
497 opt_name = dhcp_option_strings;
498 i = 0;
499 while (*opt_name) {
500 uint8_t code = dhcp_optflags[i].code;
501 BITMAP *found_ptr = &FOUND_OPTS(code);
502 BITMAP found_mask = BMASK(code);
503 if (!(*found_ptr & found_mask))
504 goto next;
505 *found_ptr &= ~found_mask; /* leave only unknown options */
506 temp = udhcp_get_option(packet, code);
507 *curr = xmalloc_optname_optval(temp, &dhcp_optflags[i], opt_name);
508 putenv(*curr++);
509 if (code == DHCP_SUBNET) {
510 /* Subnet option: make things like "$ip/$mask" possible */
511 uint32_t subnet;
512 move_from_unaligned32(subnet, temp);
513 *curr = xasprintf("mask=%u", mton(subnet));
514 putenv(*curr++);
515 }
516 next:
517 opt_name += strlen(opt_name) + 1;
518 i++;
519 }
520 /* Export unknown options */
521 for (i = 0; i < 256;) {
522 BITMAP bitmap = FOUND_OPTS(i);
523 if (!bitmap) {
524 i += BBITS;
525 continue;
526 }
527 if (bitmap & BMASK(i)) {
528 unsigned len, ofs;
529
530 temp = udhcp_get_option(packet, i);
531 /* udhcp_get_option returns ptr to data portion,
532 * need to go back to get len
533 */
534 len = temp[-OPT_DATA + OPT_LEN];
535 *curr = xmalloc(sizeof("optNNN=") + 1 + len*2);
536 ofs = sprintf(*curr, "opt%u=", i);
537 *bin2hex(*curr + ofs, (void*) temp, len) = '\0';
538 putenv(*curr++);
539 }
540 i++;
541 }
542
543 return envp;
544 }
545
546 /* Call a script with a par file and env vars */
547 static void udhcp_run_script(struct dhcp_packet *packet, const char *name)
548 {
549 char **envp, **curr;
550 char *argv[3];
551
552 envp = fill_envp(packet);
553
554 /* call script */
555 log1("Executing %s %s", client_config.script, name);
556 argv[0] = (char*) client_config.script;
557 argv[1] = (char*) name;
558 argv[2] = NULL;
559 spawn_and_wait(argv);
560
561 for (curr = envp; *curr; curr++) {
562 log2(" %s", *curr);
563 bb_unsetenv_and_free(*curr);
564 }
565 free(envp);
566 }
567
568
569 /*** Sending/receiving packets ***/
570
571 static ALWAYS_INLINE uint32_t random_xid(void)
572 {
573 return rand();
574 }
575
576 /* Initialize the packet with the proper defaults */
577 static void init_packet(struct dhcp_packet *packet, char type)
578 {
579 uint16_t secs;
580
581 /* Fill in: op, htype, hlen, cookie fields; message type option: */
582 udhcp_init_header(packet, type);
583
584 packet->xid = random_xid();
585
586 client_config.last_secs = monotonic_sec();
587 if (client_config.first_secs == 0)
588 client_config.first_secs = client_config.last_secs;
589 secs = client_config.last_secs - client_config.first_secs;
590 packet->secs = htons(secs);
591
592 memcpy(packet->chaddr, client_config.client_mac, 6);
593 if (client_config.clientid)
594 udhcp_add_binary_option(packet, client_config.clientid);
595 }
596
597 static void add_client_options(struct dhcp_packet *packet)
598 {
599 int i, end, len;
600
601 len = sizeof(struct ip_udp_dhcp_packet);
602 if (client_config.client_mtu == 0 ||
603 client_config.client_mtu > len)
604 udhcp_add_simple_option(packet, DHCP_MAX_SIZE, htons(len));
605
606 /* Add a "param req" option with the list of options we'd like to have
607 * from stubborn DHCP servers. Pull the data from the struct in common.c.
608 * No bounds checking because it goes towards the head of the packet. */
609 end = udhcp_end_option(packet->options);
610 len = 0;
611 for (i = 1; i < DHCP_END; i++) {
612 if (client_config.opt_mask[i >> 3] & (1 << (i & 7))) {
613 packet->options[end + OPT_DATA + len] = i;
614 len++;
615 }
616 }
617 if (len) {
618 packet->options[end + OPT_CODE] = DHCP_PARAM_REQ;
619 packet->options[end + OPT_LEN] = len;
620 packet->options[end + OPT_DATA + len] = DHCP_END;
621 }
622
623 if (client_config.vendorclass)
624 udhcp_add_binary_option(packet, client_config.vendorclass);
625 if (client_config.hostname)
626 udhcp_add_binary_option(packet, client_config.hostname);
627 if (client_config.fqdn)
628 udhcp_add_binary_option(packet, client_config.fqdn);
629
630 /* Request broadcast replies if we have no IP addr */
631 if ((option_mask32 & OPT_B) && packet->ciaddr == 0)
632 packet->flags |= htons(BROADCAST_FLAG);
633
634 /* Request broadcast replies if we have no IP addr */
635 if ((option_mask32 & OPT_B) && packet->ciaddr == 0)
636 packet->flags |= htons(BROADCAST_FLAG);
637
638 /* Add -x options if any */
639 {
640 struct option_set *curr = client_config.options;
641 while (curr) {
642 udhcp_add_binary_option(packet, curr->data);
643 curr = curr->next;
644 }
645 // if (client_config.sname)
646 // strncpy((char*)packet->sname, client_config.sname, sizeof(packet->sname) - 1);
647 // if (client_config.boot_file)
648 // strncpy((char*)packet->file, client_config.boot_file, sizeof(packet->file) - 1);
649 }
650
651 // This will be needed if we remove -V VENDOR_STR in favor of
652 // -x vendor:VENDOR_STR
653 //if (!udhcp_find_option(packet.options, DHCP_VENDOR))
654 // /* not set, set the default vendor ID */
655 // ...add (DHCP_VENDOR, "udhcp "BB_VER) opt...
656 }
657
658 /* RFC 2131
659 * 4.4.4 Use of broadcast and unicast
660 *
661 * The DHCP client broadcasts DHCPDISCOVER, DHCPREQUEST and DHCPINFORM
662 * messages, unless the client knows the address of a DHCP server.
663 * The client unicasts DHCPRELEASE messages to the server. Because
664 * the client is declining the use of the IP address supplied by the server,
665 * the client broadcasts DHCPDECLINE messages.
666 *
667 * When the DHCP client knows the address of a DHCP server, in either
668 * INIT or REBOOTING state, the client may use that address
669 * in the DHCPDISCOVER or DHCPREQUEST rather than the IP broadcast address.
670 * The client may also use unicast to send DHCPINFORM messages
671 * to a known DHCP server. If the client receives no response to DHCP
672 * messages sent to the IP address of a known DHCP server, the DHCP
673 * client reverts to using the IP broadcast address.
674 */
675
676 static int raw_bcast_from_client_config_ifindex(struct dhcp_packet *packet)
677 {
678 return udhcp_send_raw_packet(packet,
679 /*src*/ INADDR_ANY, CLIENT_PORT,
680 /*dst*/ INADDR_BROADCAST, SERVER_PORT, MAC_BCAST_ADDR,
681 client_config.ifindex);
682 }
683
684 /* Broadcast a DHCP discover packet to the network, with an optionally requested IP */
685 /* NOINLINE: limit stack usage in caller */
686 static NOINLINE int send_discover(uint32_t xid, uint32_t requested)
687 {
688 struct dhcp_packet packet;
689 static int msgs = 0;
690
691 /* Fill in: op, htype, hlen, cookie, chaddr fields,
692 * random xid field (we override it below),
693 * client-id option (unless -C), message type option:
694 */
695 init_packet(&packet, DHCPDISCOVER);
696
697 packet.xid = xid;
698 if (requested)
699 udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
700
701 /* Add options: maxsize,
702 * optionally: hostname, fqdn, vendorclass,
703 * "param req" option according to -O, options specified with -x
704 */
705 add_client_options(&packet);
706
707 if (msgs++ < 3)
708 bb_info_msg("Sending discover...");
709 return raw_bcast_from_client_config_ifindex(&packet);
710 }
711
712 /* Broadcast a DHCP request message */
713 /* RFC 2131 3.1 paragraph 3:
714 * "The client _broadcasts_ a DHCPREQUEST message..."
715 */
716 /* NOINLINE: limit stack usage in caller */
717 static NOINLINE int send_select(uint32_t xid, uint32_t server, uint32_t requested)
718 {
719 struct dhcp_packet packet;
720 struct in_addr addr;
721
722 /*
723 * RFC 2131 4.3.2 DHCPREQUEST message
724 * ...
725 * If the DHCPREQUEST message contains a 'server identifier'
726 * option, the message is in response to a DHCPOFFER message.
727 * Otherwise, the message is a request to verify or extend an
728 * existing lease. If the client uses a 'client identifier'
729 * in a DHCPREQUEST message, it MUST use that same 'client identifier'
730 * in all subsequent messages. If the client included a list
731 * of requested parameters in a DHCPDISCOVER message, it MUST
732 * include that list in all subsequent messages.
733 */
734 /* Fill in: op, htype, hlen, cookie, chaddr fields,
735 * random xid field (we override it below),
736 * client-id option (unless -C), message type option:
737 */
738 init_packet(&packet, DHCPREQUEST);
739
740 packet.xid = xid;
741 udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
742
743 udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
744
745 /* Add options: maxsize,
746 * optionally: hostname, fqdn, vendorclass,
747 * "param req" option according to -O, and options specified with -x
748 */
749 add_client_options(&packet);
750
751 addr.s_addr = requested;
752 bb_info_msg("Sending select for %s...", inet_ntoa(addr));
753 return raw_bcast_from_client_config_ifindex(&packet);
754 }
755
756 /* Unicast or broadcast a DHCP renew message */
757 /* NOINLINE: limit stack usage in caller */
758 static NOINLINE int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr)
759 {
760 struct dhcp_packet packet;
761
762 /*
763 * RFC 2131 4.3.2 DHCPREQUEST message
764 * ...
765 * DHCPREQUEST generated during RENEWING state:
766 *
767 * 'server identifier' MUST NOT be filled in, 'requested IP address'
768 * option MUST NOT be filled in, 'ciaddr' MUST be filled in with
769 * client's IP address. In this situation, the client is completely
770 * configured, and is trying to extend its lease. This message will
771 * be unicast, so no relay agents will be involved in its
772 * transmission. Because 'giaddr' is therefore not filled in, the
773 * DHCP server will trust the value in 'ciaddr', and use it when
774 * replying to the client.
775 */
776 /* Fill in: op, htype, hlen, cookie, chaddr fields,
777 * random xid field (we override it below),
778 * client-id option (unless -C), message type option:
779 */
780 init_packet(&packet, DHCPREQUEST);
781
782 packet.xid = xid;
783 packet.ciaddr = ciaddr;
784
785 /* Add options: maxsize,
786 * optionally: hostname, fqdn, vendorclass,
787 * "param req" option according to -O, and options specified with -x
788 */
789 add_client_options(&packet);
790
791 bb_info_msg("Sending renew...");
792 if (server)
793 return udhcp_send_kernel_packet(&packet,
794 ciaddr, CLIENT_PORT,
795 server, SERVER_PORT);
796 return raw_bcast_from_client_config_ifindex(&packet);
797 }
798
799 #if ENABLE_FEATURE_UDHCPC_ARPING
800 /* Broadcast a DHCP decline message */
801 /* NOINLINE: limit stack usage in caller */
802 static NOINLINE int send_decline(/*uint32_t xid,*/ uint32_t server, uint32_t requested)
803 {
804 struct dhcp_packet packet;
805
806 /* Fill in: op, htype, hlen, cookie, chaddr, random xid fields,
807 * client-id option (unless -C), message type option:
808 */
809 init_packet(&packet, DHCPDECLINE);
810
811 #if 0
812 /* RFC 2131 says DHCPDECLINE's xid is randomly selected by client,
813 * but in case the server is buggy and wants DHCPDECLINE's xid
814 * to match the xid which started entire handshake,
815 * we use the same xid we used in initial DHCPDISCOVER:
816 */
817 packet.xid = xid;
818 #endif
819 /* DHCPDECLINE uses "requested ip", not ciaddr, to store offered IP */
820 udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
821
822 udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
823
824 bb_info_msg("Sending decline...");
825 return raw_bcast_from_client_config_ifindex(&packet);
826 }
827 #endif
828
829 /* Unicast a DHCP release message */
830 static int send_release(uint32_t server, uint32_t ciaddr)
831 {
832 struct dhcp_packet packet;
833
834 /* Fill in: op, htype, hlen, cookie, chaddr, random xid fields,
835 * client-id option (unless -C), message type option:
836 */
837 init_packet(&packet, DHCPRELEASE);
838
839 /* DHCPRELEASE uses ciaddr, not "requested ip", to store IP being released */
840 packet.ciaddr = ciaddr;
841
842 udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
843
844 bb_info_msg("Sending release...");
845 return udhcp_send_kernel_packet(&packet, ciaddr, CLIENT_PORT, server, SERVER_PORT);
846 }
847
848 /* Returns -1 on errors that are fatal for the socket, -2 for those that aren't */
849 /* NOINLINE: limit stack usage in caller */
850 static NOINLINE int udhcp_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd)
851 {
852 int bytes;
853 struct ip_udp_dhcp_packet packet;
854 uint16_t check;
855 unsigned char cmsgbuf[CMSG_LEN(sizeof(struct tpacket_auxdata))];
856 struct iovec iov;
857 struct msghdr msg;
858 struct cmsghdr *cmsg;
859
860 /* used to use just safe_read(fd, &packet, sizeof(packet))
861 * but we need to check for TP_STATUS_CSUMNOTREADY :(
862 */
863 iov.iov_base = &packet;
864 iov.iov_len = sizeof(packet);
865 memset(&msg, 0, sizeof(msg));
866 msg.msg_iov = &iov;
867 msg.msg_iovlen = 1;
868 msg.msg_control = cmsgbuf;
869 msg.msg_controllen = sizeof(cmsgbuf);
870 for (;;) {
871 bytes = recvmsg(fd, &msg, 0);
872 if (bytes < 0) {
873 if (errno == EINTR)
874 continue;
875 log1("Packet read error, ignoring");
876 /* NB: possible down interface, etc. Caller should pause. */
877 return bytes; /* returns -1 */
878 }
879 break;
880 }
881
882 if (bytes < (int) (sizeof(packet.ip) + sizeof(packet.udp))) {
883 log1("Packet is too short, ignoring");
884 return -2;
885 }
886
887 if (bytes < ntohs(packet.ip.tot_len)) {
888 /* packet is bigger than sizeof(packet), we did partial read */
889 log1("Oversized packet, ignoring");
890 return -2;
891 }
892
893 /* ignore any extra garbage bytes */
894 bytes = ntohs(packet.ip.tot_len);
895
896 /* make sure its the right packet for us, and that it passes sanity checks */
897 if (packet.ip.protocol != IPPROTO_UDP
898 || packet.ip.version != IPVERSION
899 || packet.ip.ihl != (sizeof(packet.ip) >> 2)
900 || packet.udp.dest != htons(CLIENT_PORT)
901 /* || bytes > (int) sizeof(packet) - can't happen */
902 || ntohs(packet.udp.len) != (uint16_t)(bytes - sizeof(packet.ip))
903 ) {
904 log1("Unrelated/bogus packet, ignoring");
905 return -2;
906 }
907
908 /* verify IP checksum */
909 check = packet.ip.check;
910 packet.ip.check = 0;
911 if (check != inet_cksum((uint16_t *)&packet.ip, sizeof(packet.ip))) {
912 log1("Bad IP header checksum, ignoring");
913 return -2;
914 }
915
916 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
917 if (cmsg->cmsg_level == SOL_PACKET
918 && cmsg->cmsg_type == PACKET_AUXDATA
919 ) {
920 /* some VMs don't checksum UDP and TCP data
921 * they send to the same physical machine,
922 * here we detect this case:
923 */
924 struct tpacket_auxdata *aux = (void *)CMSG_DATA(cmsg);
925 if (aux->tp_status & TP_STATUS_CSUMNOTREADY)
926 goto skip_udp_sum_check;
927 }
928 }
929
930 /* verify UDP checksum. IP header has to be modified for this */
931 memset(&packet.ip, 0, offsetof(struct iphdr, protocol));
932 /* ip.xx fields which are not memset: protocol, check, saddr, daddr */
933 packet.ip.tot_len = packet.udp.len; /* yes, this is needed */
934 check = packet.udp.check;
935 packet.udp.check = 0;
936 if (check && check != inet_cksum((uint16_t *)&packet, bytes)) {
937 log1("Packet with bad UDP checksum received, ignoring");
938 return -2;
939 }
940 skip_udp_sum_check:
941
942 if (packet.data.cookie != htonl(DHCP_MAGIC)) {
943 bb_info_msg("Packet with bad magic, ignoring");
944 return -2;
945 }
946
947 log1("Received a packet");
948 udhcp_dump_packet(&packet.data);
949
950 bytes -= sizeof(packet.ip) + sizeof(packet.udp);
951 memcpy(dhcp_pkt, &packet.data, bytes);
952 return bytes;
953 }
954
955
956 /*** Main ***/
957
958 static int sockfd = -1;
959
960 #define LISTEN_NONE 0
961 #define LISTEN_KERNEL 1
962 #define LISTEN_RAW 2
963 static smallint listen_mode;
964
965 /* initial state: (re)start DHCP negotiation */
966 #define INIT_SELECTING 0
967 /* discover was sent, DHCPOFFER reply received */
968 #define REQUESTING 1
969 /* select/renew was sent, DHCPACK reply received */
970 #define BOUND 2
971 /* half of lease passed, want to renew it by sending unicast renew requests */
972 #define RENEWING 3
973 /* renew requests were not answered, lease is almost over, send broadcast renew */
974 #define REBINDING 4
975 /* manually requested renew (SIGUSR1) */
976 #define RENEW_REQUESTED 5
977 /* release, possibly manually requested (SIGUSR2) */
978 #define RELEASED 6
979 static smallint state;
980
981 static int udhcp_raw_socket(int ifindex)
982 {
983 int fd;
984 struct sockaddr_ll sock;
985
986 /*
987 * Comment:
988 *
989 * I've selected not to see LL header, so BPF doesn't see it, too.
990 * The filter may also pass non-IP and non-ARP packets, but we do
991 * a more complete check when receiving the message in userspace.
992 *
993 * and filter shamelessly stolen from:
994 *
995 * http://www.flamewarmaster.de/software/dhcpclient/
996 *
997 * There are a few other interesting ideas on that page (look under
998 * "Motivation"). Use of netlink events is most interesting. Think
999 * of various network servers listening for events and reconfiguring.
1000 * That would obsolete sending HUP signals and/or make use of restarts.
1001 *
1002 * Copyright: 2006, 2007 Stefan Rompf <sux@loplof.de>.
1003 * License: GPL v2.
1004 *
1005 * TODO: make conditional?
1006 */
1007 static const struct sock_filter filter_instr[] = {
1008 /* load 9th byte (protocol) */
1009 BPF_STMT(BPF_LD|BPF_B|BPF_ABS, 9),
1010 /* jump to L1 if it is IPPROTO_UDP, else to L4 */
1011 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, IPPROTO_UDP, 0, 6),
1012 /* L1: load halfword from offset 6 (flags and frag offset) */
1013 BPF_STMT(BPF_LD|BPF_H|BPF_ABS, 6),
1014 /* jump to L4 if any bits in frag offset field are set, else to L2 */
1015 BPF_JUMP(BPF_JMP|BPF_JSET|BPF_K, 0x1fff, 4, 0),
1016 /* L2: skip IP header (load index reg with header len) */
1017 BPF_STMT(BPF_LDX|BPF_B|BPF_MSH, 0),
1018 /* load udp destination port from halfword[header_len + 2] */
1019 BPF_STMT(BPF_LD|BPF_H|BPF_IND, 2),
1020 /* jump to L3 if udp dport is CLIENT_PORT, else to L4 */
1021 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 68, 0, 1),
1022 /* L3: accept packet */
1023 BPF_STMT(BPF_RET|BPF_K, 0xffffffff),
1024 /* L4: discard packet */
1025 BPF_STMT(BPF_RET|BPF_K, 0),
1026 };
1027 static const struct sock_fprog filter_prog = {
1028 .len = sizeof(filter_instr) / sizeof(filter_instr[0]),
1029 /* casting const away: */
1030 .filter = (struct sock_filter *) filter_instr,
1031 };
1032
1033 log1("Opening raw socket on ifindex %d", ifindex); //log2?
1034
1035 fd = xsocket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP));
1036 log1("Got raw socket fd"); //log2?
1037
1038 sock.sll_family = AF_PACKET;
1039 sock.sll_protocol = htons(ETH_P_IP);
1040 sock.sll_ifindex = ifindex;
1041 xbind(fd, (struct sockaddr *) &sock, sizeof(sock));
1042
1043 if (CLIENT_PORT == 68) {
1044 /* Use only if standard port is in use */
1045 /* Ignoring error (kernel may lack support for this) */
1046 if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter_prog,
1047 sizeof(filter_prog)) >= 0)
1048 log1("Attached filter to raw socket fd"); // log?
1049 }
1050
1051 if (setsockopt(fd, SOL_PACKET, PACKET_AUXDATA,
1052 &const_int_1, sizeof(int)) < 0
1053 ) {
1054 if (errno != ENOPROTOOPT)
1055 log1("Can't set PACKET_AUXDATA on raw socket");
1056 }
1057
1058 log1("Created raw socket");
1059
1060 return fd;
1061 }
1062
1063 static void change_listen_mode(int new_mode)
1064 {
1065 log1("Entering listen mode: %s",
1066 new_mode != LISTEN_NONE
1067 ? (new_mode == LISTEN_KERNEL ? "kernel" : "raw")
1068 : "none"
1069 );
1070
1071 listen_mode = new_mode;
1072 if (sockfd >= 0) {
1073 close(sockfd);
1074 sockfd = -1;
1075 }
1076 if (new_mode == LISTEN_KERNEL)
1077 sockfd = udhcp_listen_socket(/*INADDR_ANY,*/ CLIENT_PORT, client_config.interface);
1078 else if (new_mode != LISTEN_NONE)
1079 sockfd = udhcp_raw_socket(client_config.ifindex);
1080 /* else LISTEN_NONE: sockfd stays closed */
1081 }
1082
1083 /* Called only on SIGUSR1 */
1084 static void perform_renew(void)
1085 {
1086 bb_info_msg("Performing a DHCP renew");
1087 switch (state) {
1088 case BOUND:
1089 change_listen_mode(LISTEN_RAW); // zzz
1090 case RENEWING:
1091 case REBINDING:
1092 // state = RENEW_REQUESTED; // zzz
1093 // break;
1094 case RENEW_REQUESTED: /* impatient are we? fine, square 1 */
1095 case REQUESTING:
1096 case RELEASED:
1097 change_listen_mode(LISTEN_RAW);
1098 state = INIT_SELECTING;
1099 break;
1100 case INIT_SELECTING:
1101 break;
1102 }
1103 }
1104
1105 static void perform_release(uint32_t server_addr, uint32_t requested_ip)
1106 {
1107 char buffer[sizeof("255.255.255.255")];
1108 struct in_addr temp_addr;
1109
1110 /* send release packet */
1111 if (state == BOUND || state == RENEWING || state == REBINDING) {
1112 temp_addr.s_addr = server_addr;
1113 strcpy(buffer, inet_ntoa(temp_addr));
1114 temp_addr.s_addr = requested_ip;
1115 bb_info_msg("Unicasting a release of %s to %s",
1116 inet_ntoa(temp_addr), buffer);
1117 send_release(server_addr, requested_ip); /* unicast */
1118 udhcp_run_script(NULL, "deconfig");
1119 }
1120 bb_info_msg("Entering released state");
1121
1122 change_listen_mode(LISTEN_NONE);
1123 state = RELEASED;
1124 }
1125
1126 static uint8_t* alloc_dhcp_option(int code, const char *str, int extra)
1127 {
1128 uint8_t *storage;
1129 int len = strnlen(str, 255);
1130 storage = xzalloc(len + extra + OPT_DATA);
1131 storage[OPT_CODE] = code;
1132 storage[OPT_LEN] = len + extra;
1133 memcpy(storage + extra + OPT_DATA, str, len);
1134 return storage;
1135 }
1136
1137 #if BB_MMU
1138 static void client_background(void)
1139 {
1140 bb_daemonize(0);
1141 logmode &= ~LOGMODE_STDIO;
1142 /* rewrite pidfile, as our pid is different now */
1143 write_pidfile(client_config.pidfile);
1144 }
1145 #endif
1146
1147 //usage:#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
1148 //usage:# define IF_UDHCP_VERBOSE(...) __VA_ARGS__
1149 //usage:#else
1150 //usage:# define IF_UDHCP_VERBOSE(...)
1151 //usage:#endif
1152 //usage:#define udhcpc_trivial_usage
1153 //usage: "[-fbnq"IF_UDHCP_VERBOSE("v")"oCRB] [-i IFACE] [-r IP] [-s PROG] [-p PIDFILE]\n"
1154 //usage: " [-V VENDOR] [-x OPT:VAL]... [-O OPT]..." IF_FEATURE_UDHCP_PORT(" [-P N]")
1155 //usage:#define udhcpc_full_usage "\n"
1156 //usage: IF_LONG_OPTS(
1157 //usage: "\n -i,--interface IFACE Interface to use (default eth0)"
1158 //usage: "\n -p,--pidfile FILE Create pidfile"
1159 //usage: "\n -s,--script PROG Run PROG at DHCP events (default "CONFIG_UDHCPC_DEFAULT_SCRIPT")"
1160 //usage: "\n -B,--broadcast Request broadcast replies"
1161 //usage: "\n -t,--retries N Send up to N discover packets"
1162 //usage: "\n -T,--timeout N Pause between packets (default 3 seconds)"
1163 //usage: "\n -A,--tryagain N Wait N seconds after failure (default 20)"
1164 //usage: "\n -f,--foreground Run in foreground"
1165 //usage: USE_FOR_MMU(
1166 //usage: "\n -b,--background Background if lease is not obtained"
1167 //usage: )
1168 //usage: "\n -n,--now Exit if lease is not obtained"
1169 //usage: "\n -q,--quit Exit after obtaining lease"
1170 //usage: "\n -R,--release Release IP on exit"
1171 //usage: "\n -S,--syslog Log to syslog too"
1172 //usage: IF_FEATURE_UDHCP_PORT(
1173 //usage: "\n -P,--client-port N Use port N (default 68)"
1174 //usage: )
1175 //usage: IF_FEATURE_UDHCPC_ARPING(
1176 //usage: "\n -a,--arping Use arping to validate offered address"
1177 //usage: )
1178 //usage: "\n -O,--request-option OPT Request option OPT from server (cumulative)"
1179 //usage: "\n -o,--no-default-options Don't request any options (unless -O is given)"
1180 //usage: "\n -r,--request IP Request this IP address"
1181 //usage: "\n -x OPT:VAL Include option OPT in sent packets (cumulative)"
1182 //usage: "\n Examples of string, numeric, and hex byte opts:"
1183 //usage: "\n -x hostname:bbox - option 12"
1184 //usage: "\n -x lease:3600 - option 51 (lease time)"
1185 //usage: "\n -x 0x3d:0100BEEFC0FFEE - option 61 (client id)"
1186 //usage: "\n -F,--fqdn NAME Ask server to update DNS mapping for NAME"
1187 //usage: "\n -V,--vendorclass VENDOR Vendor identifier (default 'udhcp VERSION')"
1188 //usage: "\n -C,--clientid-none Don't send MAC as client identifier"
1189 //usage: IF_UDHCP_VERBOSE(
1190 //usage: "\n -v Verbose"
1191 //usage: )
1192 //usage: )
1193 //usage: IF_NOT_LONG_OPTS(
1194 //usage: "\n -i IFACE Interface to use (default eth0)"
1195 //usage: "\n -p FILE Create pidfile"
1196 //usage: "\n -s PROG Run PROG at DHCP events (default "CONFIG_UDHCPC_DEFAULT_SCRIPT")"
1197 //usage: "\n -B Request broadcast replies"
1198 //usage: "\n -t N Send up to N discover packets"
1199 //usage: "\n -T N Pause between packets (default 3 seconds)"
1200 //usage: "\n -A N Wait N seconds (default 20) after failure"
1201 //usage: "\n -f Run in foreground"
1202 //usage: USE_FOR_MMU(
1203 //usage: "\n -b Background if lease is not obtained"
1204 //usage: )
1205 //usage: "\n -n Exit if lease is not obtained"
1206 //usage: "\n -q Exit after obtaining lease"
1207 //usage: "\n -R Release IP on exit"
1208 //usage: "\n -S Log to syslog too"
1209 //usage: IF_FEATURE_UDHCP_PORT(
1210 //usage: "\n -P N Use port N (default 68)"
1211 //usage: )
1212 //usage: IF_FEATURE_UDHCPC_ARPING(
1213 //usage: "\n -a Use arping to validate offered address"
1214 //usage: )
1215 //usage: "\n -O OPT Request option OPT from server (cumulative)"
1216 //usage: "\n -o Don't request any options (unless -O is given)"
1217 //usage: "\n -r IP Request this IP address"
1218 //usage: "\n -x OPT:VAL Include option OPT in sent packets (cumulative)"
1219 //usage: "\n Examples of string, numeric, and hex byte opts:"
1220 //usage: "\n -x hostname:bbox - option 12"
1221 //usage: "\n -x lease:3600 - option 51 (lease time)"
1222 //usage: "\n -x 0x3d:0100BEEFC0FFEE - option 61 (client id)"
1223 //usage: "\n -F NAME Ask server to update DNS mapping for NAME"
1224 //usage: "\n -H,-h NAME Send NAME as client hostname (default none)"
1225 //usage: "\n -V VENDOR Vendor identifier (default 'udhcp VERSION')"
1226 //usage: "\n -C Don't send MAC as client identifier"
1227 //usage: IF_UDHCP_VERBOSE(
1228 //usage: "\n -v Verbose"
1229 //usage: )
1230 //usage: )
1231 //usage: "\nSignals:"
1232 //usage: "\n USR1 Renew current lease"
1233 //usage: "\n USR2 Release current lease"
1234
1235
1236 int udhcpc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1237 int udhcpc_main(int argc UNUSED_PARAM, char **argv)
1238 {
1239 uint8_t *temp, *message;
1240 const char *str_V, *str_h, *str_F, *str_r;
1241 IF_FEATURE_UDHCP_PORT(char *str_P;)
1242 void *clientid_mac_ptr;
1243 llist_t *list_O = NULL;
1244 llist_t *list_x = NULL;
1245 int tryagain_timeout = 20;
1246 int discover_timeout = 3;
1247 int discover_retries = 5;
1248 uint32_t server_addr = server_addr; /* for compiler */
1249 uint32_t requested_ip = 0;
1250 uint32_t xid = xid; /* for compiler */
1251 int packet_num;
1252 int timeout; /* must be signed */
1253 unsigned already_waited_sec;
1254 unsigned opt;
1255 int max_fd;
1256 int retval;
1257 fd_set rfds;
1258
1259 /* Default options */
1260 IF_FEATURE_UDHCP_PORT(SERVER_PORT = 67;)
1261 IF_FEATURE_UDHCP_PORT(CLIENT_PORT = 68;)
1262 client_config.interface = "eth0";
1263 client_config.script = CONFIG_UDHCPC_DEFAULT_SCRIPT;
1264 str_V = "udhcp "BB_VER;
1265
1266 /* Parse command line */
1267 /* O,x: list; -T,-t,-A take numeric param */
1268 opt_complementary = "O::x::T+:t+:A+" IF_UDHCP_VERBOSE(":vv") ;
1269
1270 IF_LONG_OPTS(applet_long_options = udhcpc_longopts;)
1271 opt = getopt32(argv, "CV:H:h:F:i:np:qRr:s:T:t:SA:O:ox:fB"
1272 "m" // zzz
1273 USE_FOR_MMU("b")
1274 IF_FEATURE_UDHCPC_ARPING("a")
1275 IF_FEATURE_UDHCP_PORT("P:")
1276 "v"
1277 , &str_V, &str_h, &str_h, &str_F
1278 , &client_config.interface, &client_config.pidfile, &str_r /* i,p */
1279 , &client_config.script /* s */
1280 , &discover_timeout, &discover_retries, &tryagain_timeout /* T,t,A */
1281 , &list_O
1282 , &list_x
1283 IF_FEATURE_UDHCP_PORT(, &str_P)
1284 IF_UDHCP_VERBOSE(, &dhcp_verbose)
1285 );
1286 if (opt & (OPT_h|OPT_H)) {
1287 //msg added 2011-11
1288 bb_error_msg("option -h NAME is deprecated, use -x hostname:NAME");
1289 client_config.hostname = alloc_dhcp_option(DHCP_HOST_NAME, str_h, 0);
1290 }
1291 if (opt & OPT_F) {
1292 /* FQDN option format: [0x51][len][flags][0][0]<fqdn> */
1293 client_config.fqdn = alloc_dhcp_option(DHCP_FQDN, str_F, 3);
1294 /* Flag bits: 0000NEOS
1295 * S: 1 = Client requests server to update A RR in DNS as well as PTR
1296 * O: 1 = Server indicates to client that DNS has been updated regardless
1297 * E: 1 = Name is in DNS format, i.e. <4>host<6>domain<3>com<0>,
1298 * not "host.domain.com". Format 0 is obsolete.
1299 * N: 1 = Client requests server to not update DNS (S must be 0 then)
1300 * Two [0] bytes which follow are deprecated and must be 0.
1301 */
1302 client_config.fqdn[OPT_DATA + 0] = 0x1;
1303 /*client_config.fqdn[OPT_DATA + 1] = 0; - xzalloc did it */
1304 /*client_config.fqdn[OPT_DATA + 2] = 0; */
1305 }
1306 if (opt & OPT_r)
1307 requested_ip = inet_addr(str_r);
1308 #if ENABLE_FEATURE_UDHCP_PORT
1309 if (opt & OPT_P) {
1310 CLIENT_PORT = xatou16(str_P);
1311 SERVER_PORT = CLIENT_PORT - 1;
1312 }
1313 #endif
1314 while (list_O) {
1315 char *optstr = llist_pop(&list_O);
1316 unsigned n = bb_strtou(optstr, NULL, 0);
1317 if (errno || n > 254) {
1318 n = udhcp_option_idx(optstr);
1319 n = dhcp_optflags[n].code;
1320 }
1321 client_config.opt_mask[n >> 3] |= 1 << (n & 7);
1322 }
1323 if (!(opt & OPT_o)) {
1324 unsigned i, n;
1325 for (i = 0; (n = dhcp_optflags[i].code) != 0; i++) {
1326 if (dhcp_optflags[i].flags & OPTION_REQ) {
1327 client_config.opt_mask[n >> 3] |= 1 << (n & 7);
1328 }
1329 }
1330 }
1331 while (list_x) {
1332 char *optstr = llist_pop(&list_x);
1333 char *colon = strchr(optstr, ':');
1334 if (colon)
1335 *colon = ' ';
1336 /* now it looks similar to udhcpd's config file line:
1337 * "optname optval", using the common routine: */
1338 udhcp_str2optset(optstr, &client_config.options);
1339 }
1340
1341 if (opt & OPT_m) // zzz
1342 minpkt = 1;
1343
1344 if (udhcp_read_interface(client_config.interface,
1345 &client_config.ifindex,
1346 NULL,
1347 client_config.client_mac,
1348 &client_config.client_mtu)
1349 ) {
1350 return 1;
1351 }
1352
1353 clientid_mac_ptr = NULL;
1354 if (!(opt & OPT_C) && !udhcp_find_option(client_config.options, DHCP_CLIENT_ID)) {
1355 /* not suppressed and not set, set the default client ID */
1356 client_config.clientid = alloc_dhcp_option(DHCP_CLIENT_ID, "", 7);
1357 client_config.clientid[OPT_DATA] = 1; /* type: ethernet */
1358 clientid_mac_ptr = client_config.clientid + OPT_DATA+1;
1359 memcpy(clientid_mac_ptr, client_config.client_mac, 6);
1360 }
1361 if (str_V[0] != '\0') {
1362 // can drop -V, str_V, client_config.vendorclass,
1363 // but need to add "vendor" to the list of recognized
1364 // string opts for this to work;
1365 // and need to tweak add_client_options() too...
1366 // ...so the question is, should we?
1367 //bb_error_msg("option -V VENDOR is deprecated, use -x vendor:VENDOR");
1368 client_config.vendorclass = alloc_dhcp_option(DHCP_VENDOR, str_V, 0);
1369 }
1370
1371 #if !BB_MMU
1372 /* on NOMMU reexec (i.e., background) early */
1373 if (!(opt & OPT_f)) {
1374 bb_daemonize_or_rexec(0 /* flags */, argv);
1375 logmode = LOGMODE_NONE;
1376 }
1377 #endif
1378 if (opt & OPT_S) {
1379 openlog(applet_name, LOG_PID, LOG_DAEMON);
1380 logmode |= LOGMODE_SYSLOG;
1381 }
1382
1383 /* Make sure fd 0,1,2 are open */
1384 bb_sanitize_stdio();
1385 /* Equivalent of doing a fflush after every \n */
1386 setlinebuf(stdout);
1387 /* Create pidfile */
1388 write_pidfile(client_config.pidfile);
1389 /* Goes to stdout (unless NOMMU) and possibly syslog */
1390 bb_info_msg("%s (v"BB_VER") started", applet_name);
1391 /* Set up the signal pipe */
1392 udhcp_sp_setup();
1393 /* We want random_xid to be random... */
1394 srand(monotonic_us());
1395
1396 state = INIT_SELECTING;
1397 udhcp_run_script(NULL, "deconfig");
1398 change_listen_mode(LISTEN_RAW);
1399 packet_num = 0;
1400 timeout = 0;
1401 already_waited_sec = 0;
1402
1403 /* Main event loop. select() waits on signal pipe and possibly
1404 * on sockfd.
1405 * "continue" statements in code below jump to the top of the loop.
1406 */
1407 for (;;) {
1408 struct timeval tv;
1409 struct dhcp_packet packet;
1410 /* silence "uninitialized!" warning */
1411 unsigned timestamp_before_wait = timestamp_before_wait;
1412
1413 //bb_error_msg("sockfd:%d, listen_mode:%d", sockfd, listen_mode);
1414
1415 /* Was opening raw or udp socket here
1416 * if (listen_mode != LISTEN_NONE && sockfd < 0),
1417 * but on fast network renew responses return faster
1418 * than we open sockets. Thus this code is moved
1419 * to change_listen_mode(). Thus we open listen socket
1420 * BEFORE we send renew request (see "case BOUND:"). */
1421
1422 max_fd = udhcp_sp_fd_set(&rfds, sockfd);
1423
1424 tv.tv_sec = timeout - already_waited_sec;
1425 tv.tv_usec = 0;
1426 retval = 0;
1427 /* If we already timed out, fall through with retval = 0, else... */
1428 if ((int)tv.tv_sec > 0) {
1429 log1("Waiting on select %u seconds", (int)tv.tv_sec);
1430 timestamp_before_wait = (unsigned)monotonic_sec();
1431 retval = select(max_fd + 1, &rfds, NULL, NULL, &tv);
1432 if (retval < 0) {
1433 /* EINTR? A signal was caught, don't panic */
1434 if (errno == EINTR) {
1435 already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait;
1436 continue;
1437 }
1438 /* Else: an error occured, panic! */
1439 bb_perror_msg_and_die("select");
1440 }
1441 }
1442
1443 /* If timeout dropped to zero, time to become active:
1444 * resend discover/renew/whatever
1445 */
1446 if (retval == 0) {
1447 /* When running on a bridge, the ifindex may have changed
1448 * (e.g. if member interfaces were added/removed
1449 * or if the status of the bridge changed).
1450 * Refresh ifindex and client_mac:
1451 */
1452 if (udhcp_read_interface(client_config.interface,
1453 &client_config.ifindex,
1454 NULL,
1455 client_config.client_mac,
1456 &client_config.client_mtu)
1457 ) {
1458 goto ret0; /* iface is gone? */
1459 }
1460 if (clientid_mac_ptr)
1461 memcpy(clientid_mac_ptr, client_config.client_mac, 6);
1462
1463 /* We will restart the wait in any case */
1464 already_waited_sec = 0;
1465
1466 switch (state) {
1467 case INIT_SELECTING:
1468 if (!discover_retries || packet_num < discover_retries) {
1469 if (packet_num == 0)
1470 xid = random_xid();
1471 /* broadcast */
1472 send_discover(xid, requested_ip);
1473 timeout = discover_timeout;
1474 packet_num++;
1475 continue;
1476 }
1477 leasefail:
1478 udhcp_run_script(NULL, "leasefail");
1479 #if BB_MMU /* -b is not supported on NOMMU */
1480 if (opt & OPT_b) { /* background if no lease */
1481 bb_info_msg("No lease, forking to background");
1482 client_background();
1483 /* do not background again! */
1484 opt = ((opt & ~OPT_b) | OPT_f);
1485 } else
1486 #endif
1487 if (opt & OPT_n) { /* abort if no lease */
1488 bb_info_msg("No lease, failing");
1489 retval = 1;
1490 goto ret;
1491 }
1492 /* wait before trying again */
1493 timeout = tryagain_timeout;
1494 packet_num = 0;
1495 continue;
1496 case REQUESTING:
1497 if (!discover_retries || packet_num < discover_retries) {
1498 /* send broadcast select packet */
1499 send_select(xid, server_addr, requested_ip);
1500 timeout = discover_timeout;
1501 packet_num++;
1502 continue;
1503 }
1504 /* Timed out, go back to init state.
1505 * "discover...select...discover..." loops
1506 * were seen in the wild. Treat them similarly
1507 * to "no response to discover" case */
1508 change_listen_mode(LISTEN_RAW);
1509 state = INIT_SELECTING;
1510 goto leasefail;
1511 case BOUND:
1512 /* 1/2 lease passed, enter renewing state */
1513 state = RENEWING;
1514 client_config.first_secs = 0; /* make secs field count from 0 */
1515 change_listen_mode(LISTEN_RAW); // was: LISTEN_KERNEL -- zzz
1516 log1("Entering renew state");
1517 /* fall right through */
1518 case RENEW_REQUESTED: /* manual (SIGUSR1) renew */
1519 case_RENEW_REQUESTED:
1520 case RENEWING:
1521 if (timeout > 60) {
1522 /* send an unicast renew request */
1523 /* Sometimes observed to fail (EADDRNOTAVAIL) to bind
1524 * a new UDP socket for sending inside send_renew.
1525 * I hazard to guess existing listening socket
1526 * is somehow conflicting with it, but why is it
1527 * not deterministic then?! Strange.
1528 * Anyway, it does recover by eventually failing through
1529 * into INIT_SELECTING state.
1530 */
1531 send_renew(xid, server_addr, requested_ip);
1532 timeout >>= 1;
1533 continue;
1534 }
1535 /* Timed out, enter rebinding state */
1536 log1("Entering rebinding state");
1537 state = REBINDING;
1538 /* fall right through */
1539 case REBINDING:
1540 /* Switch to bcast receive */
1541 change_listen_mode(LISTEN_RAW);
1542 /* Lease is *really* about to run out,
1543 * try to find DHCP server using broadcast */
1544 if (timeout > 0) {
1545 /* send a broadcast renew request */
1546 send_renew(xid, 0 /*INADDR_ANY*/, requested_ip);
1547 timeout >>= 1;
1548 continue;
1549 }
1550 /* Timed out, enter init state */
1551 bb_info_msg("Lease lost, entering init state");
1552 udhcp_run_script(NULL, "deconfig");
1553 state = INIT_SELECTING;
1554 client_config.first_secs = 0; /* make secs field count from 0 */
1555 /*timeout = 0; - already is */
1556 packet_num = 0;
1557 continue;
1558 /* case RELEASED: */
1559 }
1560 /* yah, I know, *you* say it would never happen */
1561 timeout = INT_MAX;
1562 continue; /* back to main loop */
1563 } /* if select timed out */
1564
1565 /* select() didn't timeout, something happened */
1566
1567 /* Is it a signal? */
1568 /* note: udhcp_sp_read checks FD_ISSET before reading */
1569 switch (udhcp_sp_read(&rfds)) {
1570 case SIGUSR1:
1571 client_config.first_secs = 0; /* make secs field count from 0 */
1572 // already_waited_sec = 0; /* shibby - this broke tomato renew button */
1573 perform_renew();
1574 if (state == RENEW_REQUESTED)
1575 // if (timeout > tryagain_timeout) /* shibby - this broke tomato renew button */
1576 // timeout = tryagain_timeout; /* shibby - this broke tomato renew button */
1577 goto case_RENEW_REQUESTED;
1578 /* Start things over */
1579 packet_num = 0;
1580 /* Kill any timeouts, user wants this to hurry along */
1581 timeout = 0;
1582 continue;
1583 case SIGUSR2:
1584 perform_release(server_addr, requested_ip);
1585 timeout = INT_MAX;
1586 continue;
1587 case SIGTERM:
1588 bb_info_msg("Received SIGTERM");
1589 goto ret0;
1590 }
1591
1592 /* Is it a packet? */
1593 if (listen_mode == LISTEN_NONE || !FD_ISSET(sockfd, &rfds))
1594 continue; /* no */
1595
1596 {
1597 int len;
1598
1599 /* A packet is ready, read it */
1600 if (listen_mode == LISTEN_KERNEL)
1601 len = udhcp_recv_kernel_packet(&packet, sockfd);
1602 else
1603 len = udhcp_recv_raw_packet(&packet, sockfd);
1604 if (len == -1) {
1605 /* Error is severe, reopen socket */
1606 bb_info_msg("Read error: %s, reopening socket", strerror(errno));
1607 sleep(discover_timeout); /* 3 seconds by default */
1608 change_listen_mode(listen_mode); /* just close and reopen */
1609 }
1610 /* If this packet will turn out to be unrelated/bogus,
1611 * we will go back and wait for next one.
1612 * Be sure timeout is properly decreased. */
1613 already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait;
1614 if (len < 0)
1615 continue;
1616 }
1617
1618 if (packet.xid != xid) {
1619 log1("xid %x (our is %x), ignoring packet",
1620 (unsigned)packet.xid, (unsigned)xid);
1621 continue;
1622 }
1623
1624 /* Ignore packets that aren't for us */
1625 if (packet.hlen != 6
1626 || memcmp(packet.chaddr, client_config.client_mac, 6) != 0
1627 ) {
1628 //FIXME: need to also check that last 10 bytes are zero
1629 log1("chaddr does not match, ignoring packet"); // log2?
1630 continue;
1631 }
1632
1633 message = udhcp_get_option(&packet, DHCP_MESSAGE_TYPE);
1634 if (message == NULL) {
1635 bb_error_msg("no message type option, ignoring packet");
1636 continue;
1637 }
1638
1639 switch (state) {
1640 case INIT_SELECTING:
1641 /* Must be a DHCPOFFER */
1642 if (*message == DHCPOFFER) {
1643 /* What exactly is server's IP? There are several values.
1644 * Example DHCP offer captured with tchdump:
1645 *
1646 * 10.34.25.254:67 > 10.34.25.202:68 // IP header's src
1647 * BOOTP fields:
1648 * Your-IP 10.34.25.202
1649 * Server-IP 10.34.32.125 // "next server" IP
1650 * Gateway-IP 10.34.25.254 // relay's address (if DHCP relays are in use)
1651 * DHCP options:
1652 * DHCP-Message Option 53, length 1: Offer
1653 * Server-ID Option 54, length 4: 10.34.255.7 // "server ID"
1654 * Default-Gateway Option 3, length 4: 10.34.25.254 // router
1655 *
1656 * We think that real server IP (one to use in renew/release)
1657 * is one in Server-ID option. But I am not 100% sure.
1658 * IP header's src and Gateway-IP (same in this example)
1659 * might work too.
1660 * "Next server" and router are definitely wrong ones to use, though...
1661 */
1662 temp = udhcp_get_option(&packet, DHCP_SERVER_ID);
1663 if (!temp) {
1664 bb_error_msg("no server ID, ignoring packet");
1665 continue;
1666 /* still selecting - this server looks bad */
1667 }
1668 /* it IS unaligned sometimes, don't "optimize" */
1669 move_from_unaligned32(server_addr, temp);
1670 /*xid = packet.xid; - already is */
1671 requested_ip = packet.yiaddr;
1672
1673 /* enter requesting state */
1674 state = REQUESTING;
1675 timeout = 0;
1676 packet_num = 0;
1677 already_waited_sec = 0;
1678 }
1679 continue;
1680 case REQUESTING:
1681 case RENEWING:
1682 case RENEW_REQUESTED:
1683 case REBINDING:
1684 if (*message == DHCPACK) {
1685 uint32_t lease_seconds;
1686 struct in_addr temp_addr;
1687
1688 temp = udhcp_get_option(&packet, DHCP_LEASE_TIME);
1689 if (!temp) {
1690 bb_error_msg("no lease time with ACK, using 1 hour lease");
1691 lease_seconds = 60 * 60;
1692 } else {
1693 /* it IS unaligned sometimes, don't "optimize" */
1694 move_from_unaligned32(lease_seconds, temp);
1695 lease_seconds = ntohl(lease_seconds);
1696 /* paranoia: must not be too small and not prone to overflows */
1697 if (lease_seconds < 0x10)
1698 lease_seconds = 0x10;
1699 if (lease_seconds >= 0x10000000)
1700 lease_seconds = 0x0fffffff;
1701 }
1702 #if ENABLE_FEATURE_UDHCPC_ARPING
1703 if (opt & OPT_a) {
1704 /* RFC 2131 3.1 paragraph 5:
1705 * "The client receives the DHCPACK message with configuration
1706 * parameters. The client SHOULD perform a final check on the
1707 * parameters (e.g., ARP for allocated network address), and notes
1708 * the duration of the lease specified in the DHCPACK message. At this
1709 * point, the client is configured. If the client detects that the
1710 * address is already in use (e.g., through the use of ARP),
1711 * the client MUST send a DHCPDECLINE message to the server and restarts
1712 * the configuration process..." */
1713 if (!arpping(packet.yiaddr,
1714 NULL,
1715 (uint32_t) 0,
1716 client_config.client_mac,
1717 client_config.interface)
1718 ) {
1719 bb_info_msg("Offered address is in use "
1720 "(got ARP reply), declining");
1721 send_decline(/*xid,*/ server_addr, packet.yiaddr);
1722
1723 if (state != REQUESTING)
1724 udhcp_run_script(NULL, "deconfig");
1725 change_listen_mode(LISTEN_RAW);
1726 state = INIT_SELECTING;
1727 client_config.first_secs = 0; /* make secs field count from 0 */
1728 requested_ip = 0;
1729 timeout = tryagain_timeout;
1730 packet_num = 0;
1731 already_waited_sec = 0;
1732 continue; /* back to main loop */
1733 }
1734 }
1735 #endif
1736 /* enter bound state */
1737 timeout = lease_seconds / 2;
1738 temp_addr.s_addr = packet.yiaddr;
1739 bb_info_msg("Lease of %s obtained, lease time %u",
1740 inet_ntoa(temp_addr), (unsigned)lease_seconds);
1741 requested_ip = packet.yiaddr;
1742 udhcp_run_script(&packet, state == REQUESTING ? "bound" : "renew");
1743
1744 state = BOUND;
1745 change_listen_mode(LISTEN_NONE);
1746 if (opt & OPT_q) { /* quit after lease */
1747 goto ret0;
1748 }
1749 /* future renew failures should not exit (JM) */
1750 opt &= ~OPT_n;
1751 #if BB_MMU /* NOMMU case backgrounded earlier */
1752 if (!(opt & OPT_f)) {
1753 client_background();
1754 /* do not background again! */
1755 opt = ((opt & ~OPT_b) | OPT_f);
1756 }
1757 #endif
1758 /* make future renew packets use different xid */
1759 /* xid = random_xid(); ...but why bother? */
1760 already_waited_sec = 0;
1761 continue; /* back to main loop */
1762 }
1763 if (*message == DHCPNAK) {
1764 /* return to init state */
1765 bb_info_msg("Received DHCP NAK");
1766 udhcp_run_script(&packet, "nak");
1767 if (state != REQUESTING)
1768 udhcp_run_script(NULL, "deconfig");
1769 change_listen_mode(LISTEN_RAW);
1770 sleep(3); /* avoid excessive network traffic */
1771 state = INIT_SELECTING;
1772 client_config.first_secs = 0; /* make secs field count from 0 */
1773 requested_ip = 0;
1774 timeout = 0;
1775 packet_num = 0;
1776 already_waited_sec = 0;
1777 }
1778 continue;
1779 /* case BOUND: - ignore all packets */
1780 /* case RELEASED: - ignore all packets */
1781 }
1782 /* back to main loop */
1783 } /* for (;;) - main loop ends */
1784
1785 ret0:
1786 if (opt & OPT_R) /* release on quit */
1787 perform_release(server_addr, requested_ip);
1788 retval = 0;
1789 ret:
1790 /*if (client_config.pidfile) - remove_pidfile has its own check */
1791 remove_pidfile(client_config.pidfile);
1792 return retval;
1793 }
Tomato firmware and modifications.