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busybox: update to 1.23.2
[tomato.git] / release / src / router / busybox / networking / udhcp / dhcpc.c
blobb8c165ad4c66166d65d073e29edc3390bf3341b7
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" Optional_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 #if ENABLE_FEATURE_UDHCPC_SANITIZEOPT
147 /* Check if a given label represents a valid DNS label
148 * Return pointer to the first character after the label upon success,
149 * NULL otherwise.
150 * See RFC1035, 2.3.1
151 */
152 /* We don't need to be particularly anal. For example, allowing _, hyphen
153 * at the end, or leading and trailing dots would be ok, since it
154 * can't be used for attacks. (Leading hyphen can be, if someone uses
155 * cmd "$hostname"
156 * in the script: then hostname may be treated as an option)
157 */
158 static const char *valid_domain_label(const char *label)
159 {
160 unsigned char ch;
161 unsigned pos = 0;
162
163 for (;;) {
164 ch = *label;
165 if ((ch|0x20) < 'a' || (ch|0x20) > 'z') {
166 if (pos == 0) {
167 /* label must begin with letter */
168 return NULL;
169 }
170 if (ch < '0' || ch > '9') {
171 if (ch == '\0' || ch == '.')
172 return label;
173 /* DNS allows only '-', but we are more permissive */
174 if (ch != '-' && ch != '_')
175 return NULL;
176 }
177 }
178 label++;
179 pos++;
180 //Do we want this?
181 //if (pos > 63) /* NS_MAXLABEL; labels must be 63 chars or less */
182 // return NULL;
183 }
184 }
185
186 /* Check if a given name represents a valid DNS name */
187 /* See RFC1035, 2.3.1 */
188 static int good_hostname(const char *name)
189 {
190 //const char *start = name;
191
192 for (;;) {
193 name = valid_domain_label(name);
194 if (!name)
195 return 0;
196 if (!name[0])
197 return 1;
198 //Do we want this?
199 //return ((name - start) < 1025); /* NS_MAXDNAME */
200 name++;
201 }
202 }
203 #else
204 # define good_hostname(name) 1
205 #endif
206
207 /* Create "opt_name=opt_value" string */
208 static NOINLINE char *xmalloc_optname_optval(uint8_t *option, const struct dhcp_optflag *optflag, const char *opt_name)
209 {
210 unsigned upper_length;
211 int len, type, optlen;
212 char *dest, *ret;
213
214 /* option points to OPT_DATA, need to go back to get OPT_LEN */
215 len = option[-OPT_DATA + OPT_LEN];
216
217 type = optflag->flags & OPTION_TYPE_MASK;
218 optlen = dhcp_option_lengths[type];
219 upper_length = len_of_option_as_string[type]
220 * ((unsigned)(len + optlen - 1) / (unsigned)optlen);
221
222 dest = ret = xmalloc(upper_length + strlen(opt_name) + 2);
223 dest += sprintf(ret, "%s=", opt_name);
224
225 while (len >= optlen) {
226 switch (type) {
227 case OPTION_IP:
228 case OPTION_IP_PAIR:
229 dest += sprint_nip(dest, "", option);
230 if (type == OPTION_IP)
231 break;
232 dest += sprint_nip(dest, "/", option + 4);
233 break;
234 // case OPTION_BOOLEAN:
235 // dest += sprintf(dest, *option ? "yes" : "no");
236 // break;
237 case OPTION_U8:
238 dest += sprintf(dest, "%u", *option);
239 break;
240 // case OPTION_S16:
241 case OPTION_U16: {
242 uint16_t val_u16;
243 move_from_unaligned16(val_u16, option);
244 dest += sprintf(dest, "%u", ntohs(val_u16));
245 break;
246 }
247 case OPTION_S32:
248 case OPTION_U32: {
249 uint32_t val_u32;
250 move_from_unaligned32(val_u32, option);
251 dest += sprintf(dest, type == OPTION_U32 ? "%lu" : "%ld", (unsigned long) ntohl(val_u32));
252 break;
253 }
254 /* Note: options which use 'return' instead of 'break'
255 * (for example, OPTION_STRING) skip the code which handles
256 * the case of list of options.
257 */
258 case OPTION_STRING:
259 case OPTION_STRING_HOST:
260 memcpy(dest, option, len);
261 dest[len] = '\0';
262 if (type == OPTION_STRING_HOST && !good_hostname(dest))
263 safe_strncpy(dest, "bad", len);
264 return ret;
265 case OPTION_STATIC_ROUTES: {
266 /* Option binary format:
267 * mask [one byte, 0..32]
268 * ip [big endian, 0..4 bytes depending on mask]
269 * router [big endian, 4 bytes]
270 * may be repeated
271 *
272 * We convert it to a string "IP/MASK ROUTER IP2/MASK2 ROUTER2"
273 */
274 const char *pfx = "";
275
276 while (len >= 1 + 4) { /* mask + 0-byte ip + router */
277 uint32_t nip;
278 uint8_t *p;
279 unsigned mask;
280 int bytes;
281
282 mask = *option++;
283 if (mask > 32)
284 break;
285 len--;
286
287 nip = 0;
288 p = (void*) &nip;
289 bytes = (mask + 7) / 8; /* 0 -> 0, 1..8 -> 1, 9..16 -> 2 etc */
290 while (--bytes >= 0) {
291 *p++ = *option++;
292 len--;
293 }
294 if (len < 4)
295 break;
296
297 /* print ip/mask */
298 dest += sprint_nip(dest, pfx, (void*) &nip);
299 pfx = " ";
300 dest += sprintf(dest, "/%u ", mask);
301 /* print router */
302 dest += sprint_nip(dest, "", option);
303 option += 4;
304 len -= 4;
305 }
306
307 return ret;
308 }
309 case OPTION_6RD:
310 /* Option binary format (see RFC 5969):
311 * 0 1 2 3
312 * 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
313 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
314 * | OPTION_6RD | option-length | IPv4MaskLen | 6rdPrefixLen |
315 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
316 * | 6rdPrefix |
317 * ... (16 octets) ...
318 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
319 * ... 6rdBRIPv4Address(es) ...
320 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
321 * We convert it to a string
322 * "IPv4MaskLen 6rdPrefixLen 6rdPrefix 6rdBRIPv4Address..."
323 *
324 * Sanity check: ensure that our length is at least 22 bytes, that
325 * IPv4MaskLen <= 32,
326 * 6rdPrefixLen <= 128,
327 * 6rdPrefixLen + (32 - IPv4MaskLen) <= 128
328 * (2nd condition need no check - it follows from 1st and 3rd).
329 * Else, return envvar with empty value ("optname=")
330 */
331 if (len >= (1 + 1 + 16 + 4)
332 && option[0] <= 32
333 && (option[1] + 32 - option[0]) <= 128
334 ) {
335 /* IPv4MaskLen */
336 dest += sprintf(dest, "%u ", *option++);
337 /* 6rdPrefixLen */
338 dest += sprintf(dest, "%u ", *option++);
339 /* 6rdPrefix */
340 dest += sprint_nip6(dest, /* "", */ option);
341 option += 16;
342 len -= 1 + 1 + 16 + 4;
343 /* "+ 4" above corresponds to the length of IPv4 addr
344 * we consume in the loop below */
345 while (1) {
346 /* 6rdBRIPv4Address(es) */
347 dest += sprint_nip(dest, " ", option);
348 option += 4;
349 len -= 4; /* do we have yet another 4+ bytes? */
350 if (len < 0)
351 break; /* no */
352 }
353 }
354
355 return ret;
356 #if ENABLE_FEATURE_UDHCP_RFC3397
357 case OPTION_DNS_STRING:
358 /* unpack option into dest; use ret for prefix (i.e., "optname=") */
359 dest = dname_dec(option, len, ret);
360 if (dest) {
361 free(ret);
362 return dest;
363 }
364 /* error. return "optname=" string */
365 return ret;
366 case OPTION_SIP_SERVERS:
367 /* Option binary format:
368 * type: byte
369 * type=0: domain names, dns-compressed
370 * type=1: IP addrs
371 */
372 option++;
373 len--;
374 if (option[-1] == 0) {
375 dest = dname_dec(option, len, ret);
376 if (dest) {
377 free(ret);
378 return dest;
379 }
380 } else
381 if (option[-1] == 1) {
382 const char *pfx = "";
383 while (1) {
384 len -= 4;
385 if (len < 0)
386 break;
387 dest += sprint_nip(dest, pfx, option);
388 pfx = " ";
389 option += 4;
390 }
391 }
392 return ret;
393 #endif
394 } /* switch */
395
396 /* If we are here, try to format any remaining data
397 * in the option as another, similarly-formatted option
398 */
399 option += optlen;
400 len -= optlen;
401 // TODO: it can be a list only if (optflag->flags & OPTION_LIST).
402 // Should we bail out/warn if we see multi-ip option which is
403 // not allowed to be such (for example, DHCP_BROADCAST)? -
404 if (len < optlen /* || !(optflag->flags & OPTION_LIST) */)
405 break;
406 *dest++ = ' ';
407 *dest = '\0';
408 } /* while */
409
410 return ret;
411 }
412
413 /* put all the parameters into the environment */
414 static char **fill_envp(struct dhcp_packet *packet)
415 {
416 int envc;
417 int i;
418 char **envp, **curr;
419 const char *opt_name;
420 uint8_t *temp;
421 uint8_t overload = 0;
422
423 #define BITMAP unsigned
424 #define BBITS (sizeof(BITMAP) * 8)
425 #define BMASK(i) (1 << (i & (sizeof(BITMAP) * 8 - 1)))
426 #define FOUND_OPTS(i) (found_opts[(unsigned)i / BBITS])
427 BITMAP found_opts[256 / BBITS];
428
429 memset(found_opts, 0, sizeof(found_opts));
430
431 /* We need 6 elements for:
432 * "interface=IFACE"
433 * "ip=N.N.N.N" from packet->yiaddr
434 * "siaddr=IP" from packet->siaddr_nip (unless 0)
435 * "boot_file=FILE" from packet->file (unless overloaded)
436 * "sname=SERVER_HOSTNAME" from packet->sname (unless overloaded)
437 * terminating NULL
438 */
439 envc = 6;
440 /* +1 element for each option, +2 for subnet option: */
441 if (packet) {
442 /* note: do not search for "pad" (0) and "end" (255) options */
443 //TODO: change logic to scan packet _once_
444 for (i = 1; i < 255; i++) {
445 temp = udhcp_get_option(packet, i);
446 if (temp) {
447 if (i == DHCP_OPTION_OVERLOAD)
448 overload = *temp;
449 else if (i == DHCP_SUBNET)
450 envc++; /* for $mask */
451 envc++;
452 /*if (i != DHCP_MESSAGE_TYPE)*/
453 FOUND_OPTS(i) |= BMASK(i);
454 }
455 }
456 }
457 curr = envp = xzalloc(sizeof(envp[0]) * envc);
458
459 *curr = xasprintf("interface=%s", client_config.interface);
460 putenv(*curr++);
461
462 if (!packet)
463 return envp;
464
465 /* Export BOOTP fields. Fields we don't (yet?) export:
466 * uint8_t op; // always BOOTREPLY
467 * uint8_t htype; // hardware address type. 1 = 10mb ethernet
468 * uint8_t hlen; // hardware address length
469 * uint8_t hops; // used by relay agents only
470 * uint32_t xid;
471 * uint16_t secs; // elapsed since client began acquisition/renewal
472 * uint16_t flags; // only one flag so far: bcast. Never set by server
473 * uint32_t ciaddr; // client IP (usually == yiaddr. can it be different
474 * // if during renew server wants to give us differn IP?)
475 * uint32_t gateway_nip; // relay agent IP address
476 * uint8_t chaddr[16]; // link-layer client hardware address (MAC)
477 * TODO: export gateway_nip as $giaddr?
478 */
479 /* Most important one: yiaddr as $ip */
480 *curr = xmalloc(sizeof("ip=255.255.255.255"));
481 sprint_nip(*curr, "ip=", (uint8_t *) &packet->yiaddr);
482 putenv(*curr++);
483 if (packet->siaddr_nip) {
484 /* IP address of next server to use in bootstrap */
485 *curr = xmalloc(sizeof("siaddr=255.255.255.255"));
486 sprint_nip(*curr, "siaddr=", (uint8_t *) &packet->siaddr_nip);
487 putenv(*curr++);
488 }
489 if (!(overload & FILE_FIELD) && packet->file[0]) {
490 /* watch out for invalid packets */
491 *curr = xasprintf("boot_file=%."DHCP_PKT_FILE_LEN_STR"s", packet->file);
492 putenv(*curr++);
493 }
494 if (!(overload & SNAME_FIELD) && packet->sname[0]) {
495 /* watch out for invalid packets */
496 *curr = xasprintf("sname=%."DHCP_PKT_SNAME_LEN_STR"s", packet->sname);
497 putenv(*curr++);
498 }
499
500 /* Export known DHCP options */
501 opt_name = dhcp_option_strings;
502 i = 0;
503 while (*opt_name) {
504 uint8_t code = dhcp_optflags[i].code;
505 BITMAP *found_ptr = &FOUND_OPTS(code);
506 BITMAP found_mask = BMASK(code);
507 if (!(*found_ptr & found_mask))
508 goto next;
509 *found_ptr &= ~found_mask; /* leave only unknown options */
510 temp = udhcp_get_option(packet, code);
511 *curr = xmalloc_optname_optval(temp, &dhcp_optflags[i], opt_name);
512 putenv(*curr++);
513 if (code == DHCP_SUBNET) {
514 /* Subnet option: make things like "$ip/$mask" possible */
515 uint32_t subnet;
516 move_from_unaligned32(subnet, temp);
517 *curr = xasprintf("mask=%u", mton(subnet));
518 putenv(*curr++);
519 }
520 next:
521 opt_name += strlen(opt_name) + 1;
522 i++;
523 }
524 /* Export unknown options */
525 for (i = 0; i < 256;) {
526 BITMAP bitmap = FOUND_OPTS(i);
527 if (!bitmap) {
528 i += BBITS;
529 continue;
530 }
531 if (bitmap & BMASK(i)) {
532 unsigned len, ofs;
533
534 temp = udhcp_get_option(packet, i);
535 /* udhcp_get_option returns ptr to data portion,
536 * need to go back to get len
537 */
538 len = temp[-OPT_DATA + OPT_LEN];
539 *curr = xmalloc(sizeof("optNNN=") + 1 + len*2);
540 ofs = sprintf(*curr, "opt%u=", i);
541 *bin2hex(*curr + ofs, (void*) temp, len) = '\0';
542 putenv(*curr++);
543 }
544 i++;
545 }
546
547 return envp;
548 }
549
550 /* Call a script with a par file and env vars */
551 static void udhcp_run_script(struct dhcp_packet *packet, const char *name)
552 {
553 char **envp, **curr;
554 char *argv[3];
555
556 envp = fill_envp(packet);
557
558 /* call script */
559 log1("Executing %s %s", client_config.script, name);
560 argv[0] = (char*) client_config.script;
561 argv[1] = (char*) name;
562 argv[2] = NULL;
563 spawn_and_wait(argv);
564
565 for (curr = envp; *curr; curr++) {
566 log2(" %s", *curr);
567 bb_unsetenv_and_free(*curr);
568 }
569 free(envp);
570 }
571
572
573 /*** Sending/receiving packets ***/
574
575 static ALWAYS_INLINE uint32_t random_xid(void)
576 {
577 return rand();
578 }
579
580 /* Initialize the packet with the proper defaults */
581 static void init_packet(struct dhcp_packet *packet, char type)
582 {
583 uint16_t secs;
584
585 /* Fill in: op, htype, hlen, cookie fields; message type option: */
586 udhcp_init_header(packet, type);
587
588 packet->xid = random_xid();
589
590 client_config.last_secs = monotonic_sec();
591 if (client_config.first_secs == 0)
592 client_config.first_secs = client_config.last_secs;
593 secs = client_config.last_secs - client_config.first_secs;
594 packet->secs = htons(secs);
595
596 memcpy(packet->chaddr, client_config.client_mac, 6);
597 if (client_config.clientid)
598 udhcp_add_binary_option(packet, client_config.clientid);
599 }
600
601 static void add_client_options(struct dhcp_packet *packet)
602 {
603 int i, end, len;
604
605 len = sizeof(struct ip_udp_dhcp_packet);
606 if (client_config.client_mtu == 0 ||
607 client_config.client_mtu > len)
608 udhcp_add_simple_option(packet, DHCP_MAX_SIZE, htons(len));
609
610 /* Add a "param req" option with the list of options we'd like to have
611 * from stubborn DHCP servers. Pull the data from the struct in common.c.
612 * No bounds checking because it goes towards the head of the packet. */
613 end = udhcp_end_option(packet->options);
614 len = 0;
615 for (i = 1; i < DHCP_END; i++) {
616 if (client_config.opt_mask[i >> 3] & (1 << (i & 7))) {
617 packet->options[end + OPT_DATA + len] = i;
618 len++;
619 }
620 }
621 if (len) {
622 packet->options[end + OPT_CODE] = DHCP_PARAM_REQ;
623 packet->options[end + OPT_LEN] = len;
624 packet->options[end + OPT_DATA + len] = DHCP_END;
625 }
626
627 if (client_config.vendorclass)
628 udhcp_add_binary_option(packet, client_config.vendorclass);
629 if (client_config.hostname)
630 udhcp_add_binary_option(packet, client_config.hostname);
631 if (client_config.fqdn)
632 udhcp_add_binary_option(packet, client_config.fqdn);
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 /* Request broadcast replies if we have no IP addr */
639 if ((option_mask32 & OPT_B) && packet->ciaddr == 0)
640 packet->flags |= htons(BROADCAST_FLAG);
641
642 /* Add -x options if any */
643 {
644 struct option_set *curr = client_config.options;
645 while (curr) {
646 udhcp_add_binary_option(packet, curr->data);
647 curr = curr->next;
648 }
649 // if (client_config.sname)
650 // strncpy((char*)packet->sname, client_config.sname, sizeof(packet->sname) - 1);
651 // if (client_config.boot_file)
652 // strncpy((char*)packet->file, client_config.boot_file, sizeof(packet->file) - 1);
653 }
654
655 // This will be needed if we remove -V VENDOR_STR in favor of
656 // -x vendor:VENDOR_STR
657 //if (!udhcp_find_option(packet.options, DHCP_VENDOR))
658 // /* not set, set the default vendor ID */
659 // ...add (DHCP_VENDOR, "udhcp "BB_VER) opt...
660 }
661
662 /* RFC 2131
663 * 4.4.4 Use of broadcast and unicast
664 *
665 * The DHCP client broadcasts DHCPDISCOVER, DHCPREQUEST and DHCPINFORM
666 * messages, unless the client knows the address of a DHCP server.
667 * The client unicasts DHCPRELEASE messages to the server. Because
668 * the client is declining the use of the IP address supplied by the server,
669 * the client broadcasts DHCPDECLINE messages.
670 *
671 * When the DHCP client knows the address of a DHCP server, in either
672 * INIT or REBOOTING state, the client may use that address
673 * in the DHCPDISCOVER or DHCPREQUEST rather than the IP broadcast address.
674 * The client may also use unicast to send DHCPINFORM messages
675 * to a known DHCP server. If the client receives no response to DHCP
676 * messages sent to the IP address of a known DHCP server, the DHCP
677 * client reverts to using the IP broadcast address.
678 */
679
680 static int raw_bcast_from_client_config_ifindex(struct dhcp_packet *packet)
681 {
682 return udhcp_send_raw_packet(packet,
683 /*src*/ INADDR_ANY, CLIENT_PORT,
684 /*dst*/ INADDR_BROADCAST, SERVER_PORT, MAC_BCAST_ADDR,
685 client_config.ifindex);
686 }
687
688 static int bcast_or_ucast(struct dhcp_packet *packet, uint32_t ciaddr, uint32_t server)
689 {
690 if (server)
691 return udhcp_send_kernel_packet(packet,
692 ciaddr, CLIENT_PORT,
693 server, SERVER_PORT);
694 return raw_bcast_from_client_config_ifindex(packet);
695 }
696
697 /* Broadcast a DHCP discover packet to the network, with an optionally requested IP */
698 /* NOINLINE: limit stack usage in caller */
699 static NOINLINE int send_discover(uint32_t xid, uint32_t requested)
700 {
701 struct dhcp_packet packet;
702 static int msgs = 0;
703
704 /* Fill in: op, htype, hlen, cookie, chaddr fields,
705 * random xid field (we override it below),
706 * client-id option (unless -C), message type option:
707 */
708 init_packet(&packet, DHCPDISCOVER);
709
710 packet.xid = xid;
711 if (requested)
712 udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
713
714 /* Add options: maxsize,
715 * optionally: hostname, fqdn, vendorclass,
716 * "param req" option according to -O, options specified with -x
717 */
718 add_client_options(&packet);
719
720 if (msgs++ < 3)
721 bb_info_msg("Sending discover...");
722 return raw_bcast_from_client_config_ifindex(&packet);
723 }
724
725 /* Broadcast a DHCP request message */
726 /* RFC 2131 3.1 paragraph 3:
727 * "The client _broadcasts_ a DHCPREQUEST message..."
728 */
729 /* NOINLINE: limit stack usage in caller */
730 static NOINLINE int send_select(uint32_t xid, uint32_t server, uint32_t requested)
731 {
732 struct dhcp_packet packet;
733 struct in_addr addr;
734
735 /*
736 * RFC 2131 4.3.2 DHCPREQUEST message
737 * ...
738 * If the DHCPREQUEST message contains a 'server identifier'
739 * option, the message is in response to a DHCPOFFER message.
740 * Otherwise, the message is a request to verify or extend an
741 * existing lease. If the client uses a 'client identifier'
742 * in a DHCPREQUEST message, it MUST use that same 'client identifier'
743 * in all subsequent messages. If the client included a list
744 * of requested parameters in a DHCPDISCOVER message, it MUST
745 * include that list in all subsequent messages.
746 */
747 /* Fill in: op, htype, hlen, cookie, chaddr fields,
748 * random xid field (we override it below),
749 * client-id option (unless -C), message type option:
750 */
751 init_packet(&packet, DHCPREQUEST);
752
753 packet.xid = xid;
754 udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
755
756 udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
757
758 /* Add options: maxsize,
759 * optionally: hostname, fqdn, vendorclass,
760 * "param req" option according to -O, and options specified with -x
761 */
762 add_client_options(&packet);
763
764 addr.s_addr = requested;
765 bb_info_msg("Sending select for %s...", inet_ntoa(addr));
766 return raw_bcast_from_client_config_ifindex(&packet);
767 }
768
769 /* Unicast or broadcast a DHCP renew message */
770 /* NOINLINE: limit stack usage in caller */
771 static NOINLINE int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr)
772 {
773 struct dhcp_packet packet;
774
775 /*
776 * RFC 2131 4.3.2 DHCPREQUEST message
777 * ...
778 * DHCPREQUEST generated during RENEWING state:
779 *
780 * 'server identifier' MUST NOT be filled in, 'requested IP address'
781 * option MUST NOT be filled in, 'ciaddr' MUST be filled in with
782 * client's IP address. In this situation, the client is completely
783 * configured, and is trying to extend its lease. This message will
784 * be unicast, so no relay agents will be involved in its
785 * transmission. Because 'giaddr' is therefore not filled in, the
786 * DHCP server will trust the value in 'ciaddr', and use it when
787 * replying to the client.
788 */
789 /* Fill in: op, htype, hlen, cookie, chaddr fields,
790 * random xid field (we override it below),
791 * client-id option (unless -C), message type option:
792 */
793 init_packet(&packet, DHCPREQUEST);
794
795 packet.xid = xid;
796 packet.ciaddr = ciaddr;
797
798 /* Add options: maxsize,
799 * optionally: hostname, fqdn, vendorclass,
800 * "param req" option according to -O, and options specified with -x
801 */
802 add_client_options(&packet);
803
804 bb_info_msg("Sending renew...");
805 return bcast_or_ucast(&packet, ciaddr, server);
806 }
807
808 #if ENABLE_FEATURE_UDHCPC_ARPING
809 /* Broadcast a DHCP decline message */
810 /* NOINLINE: limit stack usage in caller */
811 static NOINLINE int send_decline(/*uint32_t xid,*/ uint32_t server, uint32_t requested)
812 {
813 struct dhcp_packet packet;
814
815 /* Fill in: op, htype, hlen, cookie, chaddr, random xid fields,
816 * client-id option (unless -C), message type option:
817 */
818 init_packet(&packet, DHCPDECLINE);
819
820 #if 0
821 /* RFC 2131 says DHCPDECLINE's xid is randomly selected by client,
822 * but in case the server is buggy and wants DHCPDECLINE's xid
823 * to match the xid which started entire handshake,
824 * we use the same xid we used in initial DHCPDISCOVER:
825 */
826 packet.xid = xid;
827 #endif
828 /* DHCPDECLINE uses "requested ip", not ciaddr, to store offered IP */
829 udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
830
831 udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
832
833 bb_info_msg("Sending decline...");
834 return raw_bcast_from_client_config_ifindex(&packet);
835 }
836 #endif
837
838 /* Unicast a DHCP release message */
839 static int send_release(uint32_t server, uint32_t ciaddr)
840 {
841 struct dhcp_packet packet;
842
843 /* Fill in: op, htype, hlen, cookie, chaddr, random xid fields,
844 * client-id option (unless -C), message type option:
845 */
846 init_packet(&packet, DHCPRELEASE);
847
848 /* DHCPRELEASE uses ciaddr, not "requested ip", to store IP being released */
849 packet.ciaddr = ciaddr;
850
851 udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
852
853 bb_info_msg("Sending release...");
854 /* Note: normally we unicast here since "server" is not zero.
855 * However, there _are_ people who run "address-less" DHCP servers,
856 * and reportedly ISC dhcp client and Windows allow that.
857 */
858 return bcast_or_ucast(&packet, ciaddr, server);
859 }
860
861 /* Returns -1 on errors that are fatal for the socket, -2 for those that aren't */
862 /* NOINLINE: limit stack usage in caller */
863 static NOINLINE int udhcp_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd)
864 {
865 int bytes;
866 struct ip_udp_dhcp_packet packet;
867 uint16_t check;
868 unsigned char cmsgbuf[CMSG_LEN(sizeof(struct tpacket_auxdata))];
869 struct iovec iov;
870 struct msghdr msg;
871 struct cmsghdr *cmsg;
872
873 /* used to use just safe_read(fd, &packet, sizeof(packet))
874 * but we need to check for TP_STATUS_CSUMNOTREADY :(
875 */
876 iov.iov_base = &packet;
877 iov.iov_len = sizeof(packet);
878 memset(&msg, 0, sizeof(msg));
879 msg.msg_iov = &iov;
880 msg.msg_iovlen = 1;
881 msg.msg_control = cmsgbuf;
882 msg.msg_controllen = sizeof(cmsgbuf);
883 for (;;) {
884 bytes = recvmsg(fd, &msg, 0);
885 if (bytes < 0) {
886 if (errno == EINTR)
887 continue;
888 log1("Packet read error, ignoring");
889 /* NB: possible down interface, etc. Caller should pause. */
890 return bytes; /* returns -1 */
891 }
892 break;
893 }
894
895 if (bytes < (int) (sizeof(packet.ip) + sizeof(packet.udp))) {
896 log1("Packet is too short, ignoring");
897 return -2;
898 }
899
900 if (bytes < ntohs(packet.ip.tot_len)) {
901 /* packet is bigger than sizeof(packet), we did partial read */
902 log1("Oversized packet, ignoring");
903 return -2;
904 }
905
906 /* ignore any extra garbage bytes */
907 bytes = ntohs(packet.ip.tot_len);
908
909 /* make sure its the right packet for us, and that it passes sanity checks */
910 if (packet.ip.protocol != IPPROTO_UDP
911 || packet.ip.version != IPVERSION
912 || packet.ip.ihl != (sizeof(packet.ip) >> 2)
913 || packet.udp.dest != htons(CLIENT_PORT)
914 /* || bytes > (int) sizeof(packet) - can't happen */
915 || ntohs(packet.udp.len) != (uint16_t)(bytes - sizeof(packet.ip))
916 ) {
917 log1("Unrelated/bogus packet, ignoring");
918 return -2;
919 }
920
921 /* verify IP checksum */
922 check = packet.ip.check;
923 packet.ip.check = 0;
924 if (check != inet_cksum((uint16_t *)&packet.ip, sizeof(packet.ip))) {
925 log1("Bad IP header checksum, ignoring");
926 return -2;
927 }
928
929 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
930 if (cmsg->cmsg_level == SOL_PACKET
931 && cmsg->cmsg_type == PACKET_AUXDATA
932 ) {
933 /* some VMs don't checksum UDP and TCP data
934 * they send to the same physical machine,
935 * here we detect this case:
936 */
937 struct tpacket_auxdata *aux = (void *)CMSG_DATA(cmsg);
938 if (aux->tp_status & TP_STATUS_CSUMNOTREADY)
939 goto skip_udp_sum_check;
940 }
941 }
942
943 /* verify UDP checksum. IP header has to be modified for this */
944 memset(&packet.ip, 0, offsetof(struct iphdr, protocol));
945 /* ip.xx fields which are not memset: protocol, check, saddr, daddr */
946 packet.ip.tot_len = packet.udp.len; /* yes, this is needed */
947 check = packet.udp.check;
948 packet.udp.check = 0;
949 if (check && check != inet_cksum((uint16_t *)&packet, bytes)) {
950 log1("Packet with bad UDP checksum received, ignoring");
951 return -2;
952 }
953 skip_udp_sum_check:
954
955 if (packet.data.cookie != htonl(DHCP_MAGIC)) {
956 bb_info_msg("Packet with bad magic, ignoring");
957 return -2;
958 }
959
960 log1("Received a packet");
961 udhcp_dump_packet(&packet.data);
962
963 bytes -= sizeof(packet.ip) + sizeof(packet.udp);
964 memcpy(dhcp_pkt, &packet.data, bytes);
965 return bytes;
966 }
967
968
969 /*** Main ***/
970
971 static int sockfd = -1;
972
973 #define LISTEN_NONE 0
974 #define LISTEN_KERNEL 1
975 #define LISTEN_RAW 2
976 static smallint listen_mode;
977
978 /* initial state: (re)start DHCP negotiation */
979 #define INIT_SELECTING 0
980 /* discover was sent, DHCPOFFER reply received */
981 #define REQUESTING 1
982 /* select/renew was sent, DHCPACK reply received */
983 #define BOUND 2
984 /* half of lease passed, want to renew it by sending unicast renew requests */
985 #define RENEWING 3
986 /* renew requests were not answered, lease is almost over, send broadcast renew */
987 #define REBINDING 4
988 /* manually requested renew (SIGUSR1) */
989 #define RENEW_REQUESTED 5
990 /* release, possibly manually requested (SIGUSR2) */
991 #define RELEASED 6
992 static smallint state;
993
994 static int udhcp_raw_socket(int ifindex)
995 {
996 int fd;
997 struct sockaddr_ll sock;
998
999 log1("Opening raw socket on ifindex %d", ifindex); //log2?
1000
1001 fd = xsocket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP));
1002 /* ^^^^^
1003 * SOCK_DGRAM: remove link-layer headers on input (SOCK_RAW keeps them)
1004 * ETH_P_IP: want to receive only packets with IPv4 eth type
1005 */
1006 log1("Got raw socket fd"); //log2?
1007
1008 sock.sll_family = AF_PACKET;
1009 sock.sll_protocol = htons(ETH_P_IP);
1010 sock.sll_ifindex = ifindex;
1011 xbind(fd, (struct sockaddr *) &sock, sizeof(sock));
1012
1013 #if 0 /* Several users reported breakage when BPF filter is used */
1014 if (CLIENT_PORT == 68) {
1015 /* Use only if standard port is in use */
1016 /*
1017 * I've selected not to see LL header, so BPF doesn't see it, too.
1018 * The filter may also pass non-IP and non-ARP packets, but we do
1019 * a more complete check when receiving the message in userspace.
1020 *
1021 * and filter shamelessly stolen from:
1022 *
1023 * http://www.flamewarmaster.de/software/dhcpclient/
1024 *
1025 * There are a few other interesting ideas on that page (look under
1026 * "Motivation"). Use of netlink events is most interesting. Think
1027 * of various network servers listening for events and reconfiguring.
1028 * That would obsolete sending HUP signals and/or make use of restarts.
1029 *
1030 * Copyright: 2006, 2007 Stefan Rompf <sux@loplof.de>.
1031 * License: GPL v2.
1032 */
1033 static const struct sock_filter filter_instr[] = {
1034 /* load 9th byte (protocol) */
1035 BPF_STMT(BPF_LD|BPF_B|BPF_ABS, 9),
1036 /* jump to L1 if it is IPPROTO_UDP, else to L4 */
1037 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, IPPROTO_UDP, 0, 6),
1038 /* L1: load halfword from offset 6 (flags and frag offset) */
1039 BPF_STMT(BPF_LD|BPF_H|BPF_ABS, 6),
1040 /* jump to L4 if any bits in frag offset field are set, else to L2 */
1041 BPF_JUMP(BPF_JMP|BPF_JSET|BPF_K, 0x1fff, 4, 0),
1042 /* L2: skip IP header (load index reg with header len) */
1043 BPF_STMT(BPF_LDX|BPF_B|BPF_MSH, 0),
1044 /* load udp destination port from halfword[header_len + 2] */
1045 BPF_STMT(BPF_LD|BPF_H|BPF_IND, 2),
1046 /* jump to L3 if udp dport is CLIENT_PORT, else to L4 */
1047 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 68, 0, 1),
1048 /* L3: accept packet ("accept 0x7fffffff bytes") */
1049 /* Accepting 0xffffffff works too but kernel 2.6.19 is buggy */
1050 BPF_STMT(BPF_RET|BPF_K, 0x7fffffff),
1051 /* L4: discard packet ("accept zero bytes") */
1052 BPF_STMT(BPF_RET|BPF_K, 0),
1053 };
1054 static const struct sock_fprog filter_prog = {
1055 .len = sizeof(filter_instr) / sizeof(filter_instr[0]),
1056 /* casting const away: */
1057 .filter = (struct sock_filter *) filter_instr,
1058 };
1059 /* Ignoring error (kernel may lack support for this) */
1060 if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter_prog,
1061 sizeof(filter_prog)) >= 0)
1062 log1("Attached filter to raw socket fd"); // log?
1063 }
1064 #endif
1065
1066 if (setsockopt(fd, SOL_PACKET, PACKET_AUXDATA,
1067 &const_int_1, sizeof(int)) < 0
1068 ) {
1069 if (errno != ENOPROTOOPT)
1070 log1("Can't set PACKET_AUXDATA on raw socket");
1071 }
1072
1073 log1("Created raw socket");
1074
1075 return fd;
1076 }
1077
1078 static void change_listen_mode(int new_mode)
1079 {
1080 log1("Entering listen mode: %s",
1081 new_mode != LISTEN_NONE
1082 ? (new_mode == LISTEN_KERNEL ? "kernel" : "raw")
1083 : "none"
1084 );
1085
1086 listen_mode = new_mode;
1087 if (sockfd >= 0) {
1088 close(sockfd);
1089 sockfd = -1;
1090 }
1091 if (new_mode == LISTEN_KERNEL)
1092 sockfd = udhcp_listen_socket(/*INADDR_ANY,*/ CLIENT_PORT, client_config.interface);
1093 else if (new_mode != LISTEN_NONE)
1094 sockfd = udhcp_raw_socket(client_config.ifindex);
1095 /* else LISTEN_NONE: sockfd stays closed */
1096 }
1097
1098 /* Called only on SIGUSR1 */
1099 static void perform_renew(void)
1100 {
1101 bb_info_msg("Performing a DHCP renew");
1102 switch (state) {
1103 case BOUND:
1104 change_listen_mode(LISTEN_RAW); // zzz
1105 case RENEWING:
1106 case REBINDING:
1107 // state = RENEW_REQUESTED; // zzz
1108 // break;
1109 case RENEW_REQUESTED: /* impatient are we? fine, square 1 */
1110 case REQUESTING:
1111 case RELEASED:
1112 change_listen_mode(LISTEN_RAW);
1113 state = INIT_SELECTING;
1114 break;
1115 case INIT_SELECTING:
1116 break;
1117 }
1118 }
1119
1120 static void perform_release(uint32_t server_addr, uint32_t requested_ip)
1121 {
1122 char buffer[sizeof("255.255.255.255")];
1123 struct in_addr temp_addr;
1124
1125 /* send release packet */
1126 if (state == BOUND || state == RENEWING || state == REBINDING) {
1127 temp_addr.s_addr = server_addr;
1128 strcpy(buffer, inet_ntoa(temp_addr));
1129 temp_addr.s_addr = requested_ip;
1130 bb_info_msg("Unicasting a release of %s to %s",
1131 inet_ntoa(temp_addr), buffer);
1132 send_release(server_addr, requested_ip); /* unicast */
1133 udhcp_run_script(NULL, "deconfig");
1134 }
1135 bb_info_msg("Entering released state");
1136
1137 change_listen_mode(LISTEN_NONE);
1138 state = RELEASED;
1139 }
1140
1141 static uint8_t* alloc_dhcp_option(int code, const char *str, int extra)
1142 {
1143 uint8_t *storage;
1144 int len = strnlen(str, 255);
1145 storage = xzalloc(len + extra + OPT_DATA);
1146 storage[OPT_CODE] = code;
1147 storage[OPT_LEN] = len + extra;
1148 memcpy(storage + extra + OPT_DATA, str, len);
1149 return storage;
1150 }
1151
1152 #if BB_MMU
1153 static void client_background(void)
1154 {
1155 bb_daemonize(0);
1156 logmode &= ~LOGMODE_STDIO;
1157 /* rewrite pidfile, as our pid is different now */
1158 write_pidfile(client_config.pidfile);
1159 }
1160 #endif
1161
1162 //usage:#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
1163 //usage:# define IF_UDHCP_VERBOSE(...) __VA_ARGS__
1164 //usage:#else
1165 //usage:# define IF_UDHCP_VERBOSE(...)
1166 //usage:#endif
1167 //usage:#define udhcpc_trivial_usage
1168 //usage: "[-fbq"IF_UDHCP_VERBOSE("v")"RB]"IF_FEATURE_UDHCPC_ARPING(" [-a[MSEC]]")" [-t N] [-T SEC] [-A SEC/-n]\n"
1169 //usage: " [-i IFACE]"IF_FEATURE_UDHCP_PORT(" [-P PORT]")" [-s PROG] [-p PIDFILE]\n"
1170 //usage: " [-oC] [-r IP] [-V VENDOR] [-F NAME] [-x OPT:VAL]... [-O OPT]..."
1171 //usage:#define udhcpc_full_usage "\n"
1172 //usage: IF_LONG_OPTS(
1173 //usage: "\n -i,--interface IFACE Interface to use (default eth0)"
1174 //usage: IF_FEATURE_UDHCP_PORT(
1175 //usage: "\n -P,--client-port PORT Use PORT (default 68)"
1176 //usage: )
1177 //usage: "\n -s,--script PROG Run PROG at DHCP events (default "CONFIG_UDHCPC_DEFAULT_SCRIPT")"
1178 //usage: "\n -p,--pidfile FILE Create pidfile"
1179 //usage: "\n -B,--broadcast Request broadcast replies"
1180 //usage: "\n -t,--retries N Send up to N discover packets (default 3)"
1181 //usage: "\n -T,--timeout SEC Pause between packets (default 3)"
1182 //usage: "\n -A,--tryagain SEC Wait if lease is not obtained (default 20)"
1183 //usage: "\n -n,--now Exit if lease is not obtained"
1184 //usage: "\n -q,--quit Exit after obtaining lease"
1185 //usage: "\n -R,--release Release IP on exit"
1186 //usage: "\n -f,--foreground Run in foreground"
1187 //usage: USE_FOR_MMU(
1188 //usage: "\n -b,--background Background if lease is not obtained"
1189 //usage: )
1190 //usage: "\n -S,--syslog Log to syslog too"
1191 //usage: IF_FEATURE_UDHCPC_ARPING(
1192 //usage: "\n -a[MSEC],--arping[=MSEC] Validate offered address with ARP ping"
1193 //usage: )
1194 //usage: "\n -r,--request IP Request this IP address"
1195 //usage: "\n -o,--no-default-options Don't request any options (unless -O is given)"
1196 //usage: "\n -O,--request-option OPT Request option OPT from server (cumulative)"
1197 //usage: "\n -x OPT:VAL Include option OPT in sent packets (cumulative)"
1198 //usage: "\n Examples of string, numeric, and hex byte opts:"
1199 //usage: "\n -x hostname:bbox - option 12"
1200 //usage: "\n -x lease:3600 - option 51 (lease time)"
1201 //usage: "\n -x 0x3d:0100BEEFC0FFEE - option 61 (client id)"
1202 //usage: "\n -F,--fqdn NAME Ask server to update DNS mapping for NAME"
1203 //usage: "\n -V,--vendorclass VENDOR Vendor identifier (default 'udhcp VERSION')"
1204 //usage: "\n -C,--clientid-none Don't send MAC as client identifier"
1205 //usage: IF_UDHCP_VERBOSE(
1206 //usage: "\n -v Verbose"
1207 //usage: )
1208 //usage: )
1209 //usage: IF_NOT_LONG_OPTS(
1210 //usage: "\n -i IFACE Interface to use (default eth0)"
1211 //usage: IF_FEATURE_UDHCP_PORT(
1212 //usage: "\n -P PORT Use PORT (default 68)"
1213 //usage: )
1214 //usage: "\n -s PROG Run PROG at DHCP events (default "CONFIG_UDHCPC_DEFAULT_SCRIPT")"
1215 //usage: "\n -p FILE Create pidfile"
1216 //usage: "\n -B Request broadcast replies"
1217 //usage: "\n -t N Send up to N discover packets (default 3)"
1218 //usage: "\n -T SEC Pause between packets (default 3)"
1219 //usage: "\n -A SEC Wait if lease is not obtained (default 20)"
1220 //usage: "\n -n Exit if lease is not obtained"
1221 //usage: "\n -q Exit after obtaining lease"
1222 //usage: "\n -R Release IP on exit"
1223 //usage: "\n -f Run in foreground"
1224 //usage: USE_FOR_MMU(
1225 //usage: "\n -b Background if lease is not obtained"
1226 //usage: )
1227 //usage: "\n -S Log to syslog too"
1228 //usage: IF_FEATURE_UDHCPC_ARPING(
1229 //usage: "\n -a[MSEC] Validate offered address with ARP ping"
1230 //usage: )
1231 //usage: "\n -r IP Request this IP address"
1232 //usage: "\n -o Don't request any options (unless -O is given)"
1233 //usage: "\n -O OPT Request option OPT from server (cumulative)"
1234 //usage: "\n -x OPT:VAL Include option OPT in sent packets (cumulative)"
1235 //usage: "\n Examples of string, numeric, and hex byte opts:"
1236 //usage: "\n -x hostname:bbox - option 12"
1237 //usage: "\n -x lease:3600 - option 51 (lease time)"
1238 //usage: "\n -x 0x3d:0100BEEFC0FFEE - option 61 (client id)"
1239 //usage: "\n -F NAME Ask server to update DNS mapping for NAME"
1240 //usage: "\n -H,-h NAME Send NAME as client hostname (default none)"
1241 //usage: "\n -V VENDOR Vendor identifier (default 'udhcp VERSION')"
1242 //usage: "\n -C Don't send MAC as client identifier"
1243 //usage: IF_UDHCP_VERBOSE(
1244 //usage: "\n -v Verbose"
1245 //usage: )
1246 //usage: )
1247 //usage: "\nSignals:"
1248 //usage: "\n USR1 Renew current lease"
1249 //usage: "\n USR2 Release current lease"
1250
1251
1252 int udhcpc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1253 int udhcpc_main(int argc UNUSED_PARAM, char **argv)
1254 {
1255 uint8_t *message;
1256 const char *str_V, *str_h, *str_F, *str_r;
1257 IF_FEATURE_UDHCPC_ARPING(const char *str_a = "2000";)
1258 IF_FEATURE_UDHCP_PORT(char *str_P;)
1259 void *clientid_mac_ptr;
1260 llist_t *list_O = NULL;
1261 llist_t *list_x = NULL;
1262 int tryagain_timeout = 20;
1263 int discover_timeout = 3;
1264 int discover_retries = 5;
1265 uint32_t server_addr = server_addr; /* for compiler */
1266 uint32_t requested_ip = 0;
1267 uint32_t xid = xid; /* for compiler */
1268 int packet_num;
1269 int timeout; /* must be signed */
1270 unsigned already_waited_sec;
1271 unsigned opt;
1272 IF_FEATURE_UDHCPC_ARPING(unsigned arpping_ms;)
1273 int max_fd;
1274 int retval;
1275 fd_set rfds;
1276
1277 /* Default options */
1278 IF_FEATURE_UDHCP_PORT(SERVER_PORT = 67;)
1279 IF_FEATURE_UDHCP_PORT(CLIENT_PORT = 68;)
1280 client_config.interface = "eth0";
1281 client_config.script = CONFIG_UDHCPC_DEFAULT_SCRIPT;
1282 str_V = "udhcp "BB_VER;
1283
1284 /* Parse command line */
1285 /* O,x: list; -T,-t,-A take numeric param */
1286 opt_complementary = "O::x::T+:t+:A+" IF_UDHCP_VERBOSE(":vv") ;
1287
1288 IF_LONG_OPTS(applet_long_options = udhcpc_longopts;)
1289 opt = getopt32(argv, "CV:H:h:F:i:np:qRr:s:T:t:SA:O:ox:fB"
1290 "m" // zzz
1291 USE_FOR_MMU("b")
1292 IF_FEATURE_UDHCPC_ARPING("a::")
1293 IF_FEATURE_UDHCP_PORT("P:")
1294 "v"
1295 , &str_V, &str_h, &str_h, &str_F
1296 , &client_config.interface, &client_config.pidfile, &str_r /* i,p */
1297 , &client_config.script /* s */
1298 , &discover_timeout, &discover_retries, &tryagain_timeout /* T,t,A */
1299 , &list_O
1300 , &list_x
1301 IF_FEATURE_UDHCPC_ARPING(, &str_a)
1302 IF_FEATURE_UDHCP_PORT(, &str_P)
1303 IF_UDHCP_VERBOSE(, &dhcp_verbose)
1304 );
1305 if (opt & (OPT_h|OPT_H)) {
1306 //msg added 2011-11
1307 bb_error_msg("option -h NAME is deprecated, use -x hostname:NAME");
1308 client_config.hostname = alloc_dhcp_option(DHCP_HOST_NAME, str_h, 0);
1309 }
1310 if (opt & OPT_F) {
1311 /* FQDN option format: [0x51][len][flags][0][0]<fqdn> */
1312 client_config.fqdn = alloc_dhcp_option(DHCP_FQDN, str_F, 3);
1313 /* Flag bits: 0000NEOS
1314 * S: 1 = Client requests server to update A RR in DNS as well as PTR
1315 * O: 1 = Server indicates to client that DNS has been updated regardless
1316 * E: 1 = Name is in DNS format, i.e. <4>host<6>domain<3>com<0>,
1317 * not "host.domain.com". Format 0 is obsolete.
1318 * N: 1 = Client requests server to not update DNS (S must be 0 then)
1319 * Two [0] bytes which follow are deprecated and must be 0.
1320 */
1321 client_config.fqdn[OPT_DATA + 0] = 0x1;
1322 /*client_config.fqdn[OPT_DATA + 1] = 0; - xzalloc did it */
1323 /*client_config.fqdn[OPT_DATA + 2] = 0; */
1324 }
1325 if (opt & OPT_r)
1326 requested_ip = inet_addr(str_r);
1327 #if ENABLE_FEATURE_UDHCP_PORT
1328 if (opt & OPT_P) {
1329 CLIENT_PORT = xatou16(str_P);
1330 SERVER_PORT = CLIENT_PORT - 1;
1331 }
1332 #endif
1333 IF_FEATURE_UDHCPC_ARPING(arpping_ms = xatou(str_a);)
1334 while (list_O) {
1335 char *optstr = llist_pop(&list_O);
1336 unsigned n = bb_strtou(optstr, NULL, 0);
1337 if (errno || n > 254) {
1338 n = udhcp_option_idx(optstr);
1339 n = dhcp_optflags[n].code;
1340 }
1341 client_config.opt_mask[n >> 3] |= 1 << (n & 7);
1342 }
1343 if (!(opt & OPT_o)) {
1344 unsigned i, n;
1345 for (i = 0; (n = dhcp_optflags[i].code) != 0; i++) {
1346 if (dhcp_optflags[i].flags & OPTION_REQ) {
1347 client_config.opt_mask[n >> 3] |= 1 << (n & 7);
1348 }
1349 }
1350 }
1351 while (list_x) {
1352 char *optstr = llist_pop(&list_x);
1353 char *colon = strchr(optstr, ':');
1354 if (colon)
1355 *colon = ' ';
1356 /* now it looks similar to udhcpd's config file line:
1357 * "optname optval", using the common routine: */
1358 udhcp_str2optset(optstr, &client_config.options);
1359 }
1360
1361 if (opt & OPT_m) // zzz
1362 minpkt = 1;
1363
1364 if (udhcp_read_interface(client_config.interface,
1365 &client_config.ifindex,
1366 NULL,
1367 client_config.client_mac,
1368 &client_config.client_mtu)
1369 ) {
1370 return 1;
1371 }
1372
1373 clientid_mac_ptr = NULL;
1374 if (!(opt & OPT_C) && !udhcp_find_option(client_config.options, DHCP_CLIENT_ID)) {
1375 /* not suppressed and not set, set the default client ID */
1376 client_config.clientid = alloc_dhcp_option(DHCP_CLIENT_ID, "", 7);
1377 client_config.clientid[OPT_DATA] = 1; /* type: ethernet */
1378 clientid_mac_ptr = client_config.clientid + OPT_DATA+1;
1379 memcpy(clientid_mac_ptr, client_config.client_mac, 6);
1380 }
1381 if (str_V[0] != '\0') {
1382 // can drop -V, str_V, client_config.vendorclass,
1383 // but need to add "vendor" to the list of recognized
1384 // string opts for this to work;
1385 // and need to tweak add_client_options() too...
1386 // ...so the question is, should we?
1387 //bb_error_msg("option -V VENDOR is deprecated, use -x vendor:VENDOR");
1388 client_config.vendorclass = alloc_dhcp_option(DHCP_VENDOR, str_V, 0);
1389 }
1390
1391 #if !BB_MMU
1392 /* on NOMMU reexec (i.e., background) early */
1393 if (!(opt & OPT_f)) {
1394 bb_daemonize_or_rexec(0 /* flags */, argv);
1395 logmode = LOGMODE_NONE;
1396 }
1397 #endif
1398 if (opt & OPT_S) {
1399 openlog(applet_name, LOG_PID, LOG_DAEMON);
1400 logmode |= LOGMODE_SYSLOG;
1401 }
1402
1403 /* Make sure fd 0,1,2 are open */
1404 bb_sanitize_stdio();
1405 /* Equivalent of doing a fflush after every \n */
1406 setlinebuf(stdout);
1407 /* Create pidfile */
1408 write_pidfile(client_config.pidfile);
1409 /* Goes to stdout (unless NOMMU) and possibly syslog */
1410 bb_info_msg("%s (v"BB_VER") started", applet_name);
1411 /* Set up the signal pipe */
1412 udhcp_sp_setup();
1413 /* We want random_xid to be random... */
1414 srand(monotonic_us());
1415
1416 state = INIT_SELECTING;
1417 udhcp_run_script(NULL, "deconfig");
1418 change_listen_mode(LISTEN_RAW);
1419 packet_num = 0;
1420 timeout = 0;
1421 already_waited_sec = 0;
1422
1423 /* Main event loop. select() waits on signal pipe and possibly
1424 * on sockfd.
1425 * "continue" statements in code below jump to the top of the loop.
1426 */
1427 for (;;) {
1428 struct timeval tv;
1429 struct dhcp_packet packet;
1430 /* silence "uninitialized!" warning */
1431 unsigned timestamp_before_wait = timestamp_before_wait;
1432
1433 //bb_error_msg("sockfd:%d, listen_mode:%d", sockfd, listen_mode);
1434
1435 /* Was opening raw or udp socket here
1436 * if (listen_mode != LISTEN_NONE && sockfd < 0),
1437 * but on fast network renew responses return faster
1438 * than we open sockets. Thus this code is moved
1439 * to change_listen_mode(). Thus we open listen socket
1440 * BEFORE we send renew request (see "case BOUND:"). */
1441
1442 max_fd = udhcp_sp_fd_set(&rfds, sockfd);
1443
1444 tv.tv_sec = timeout - already_waited_sec;
1445 tv.tv_usec = 0;
1446 retval = 0;
1447 /* If we already timed out, fall through with retval = 0, else... */
1448 if ((int)tv.tv_sec > 0) {
1449 log1("Waiting on select %u seconds", (int)tv.tv_sec);
1450 timestamp_before_wait = (unsigned)monotonic_sec();
1451 retval = select(max_fd + 1, &rfds, NULL, NULL, &tv);
1452 if (retval < 0) {
1453 /* EINTR? A signal was caught, don't panic */
1454 if (errno == EINTR) {
1455 already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait;
1456 continue;
1457 }
1458 /* Else: an error occured, panic! */
1459 bb_perror_msg_and_die("select");
1460 }
1461 }
1462
1463 /* If timeout dropped to zero, time to become active:
1464 * resend discover/renew/whatever
1465 */
1466 if (retval == 0) {
1467 /* When running on a bridge, the ifindex may have changed
1468 * (e.g. if member interfaces were added/removed
1469 * or if the status of the bridge changed).
1470 * Refresh ifindex and client_mac:
1471 */
1472 if (udhcp_read_interface(client_config.interface,
1473 &client_config.ifindex,
1474 NULL,
1475 client_config.client_mac,
1476 &client_config.client_mtu)
1477 ) {
1478 goto ret0; /* iface is gone? */
1479 }
1480 if (clientid_mac_ptr)
1481 memcpy(clientid_mac_ptr, client_config.client_mac, 6);
1482
1483 /* We will restart the wait in any case */
1484 already_waited_sec = 0;
1485
1486 switch (state) {
1487 case INIT_SELECTING:
1488 if (!discover_retries || packet_num < discover_retries) {
1489 if (packet_num == 0)
1490 xid = random_xid();
1491 /* broadcast */
1492 send_discover(xid, requested_ip);
1493 timeout = discover_timeout;
1494 packet_num++;
1495 continue;
1496 }
1497 leasefail:
1498 udhcp_run_script(NULL, "leasefail");
1499 #if BB_MMU /* -b is not supported on NOMMU */
1500 if (opt & OPT_b) { /* background if no lease */
1501 bb_info_msg("No lease, forking to background");
1502 client_background();
1503 /* do not background again! */
1504 opt = ((opt & ~OPT_b) | OPT_f);
1505 } else
1506 #endif
1507 if (opt & OPT_n) { /* abort if no lease */
1508 bb_info_msg("No lease, failing");
1509 retval = 1;
1510 goto ret;
1511 }
1512 /* wait before trying again */
1513 timeout = tryagain_timeout;
1514 packet_num = 0;
1515 continue;
1516 case REQUESTING:
1517 if (!discover_retries || packet_num < discover_retries) {
1518 /* send broadcast select packet */
1519 send_select(xid, server_addr, requested_ip);
1520 timeout = discover_timeout;
1521 packet_num++;
1522 continue;
1523 }
1524 /* Timed out, go back to init state.
1525 * "discover...select...discover..." loops
1526 * were seen in the wild. Treat them similarly
1527 * to "no response to discover" case */
1528 change_listen_mode(LISTEN_RAW);
1529 state = INIT_SELECTING;
1530 goto leasefail;
1531 case BOUND:
1532 /* 1/2 lease passed, enter renewing state */
1533 state = RENEWING;
1534 client_config.first_secs = 0; /* make secs field count from 0 */
1535 change_listen_mode(LISTEN_RAW); // was: LISTEN_KERNEL -- zzz
1536 log1("Entering renew state");
1537 /* fall right through */
1538 case RENEW_REQUESTED: /* manual (SIGUSR1) renew */
1539 case_RENEW_REQUESTED:
1540 case RENEWING:
1541 if (timeout > 60) {
1542 /* send an unicast renew request */
1543 /* Sometimes observed to fail (EADDRNOTAVAIL) to bind
1544 * a new UDP socket for sending inside send_renew.
1545 * I hazard to guess existing listening socket
1546 * is somehow conflicting with it, but why is it
1547 * not deterministic then?! Strange.
1548 * Anyway, it does recover by eventually failing through
1549 * into INIT_SELECTING state.
1550 */
1551 send_renew(xid, server_addr, requested_ip);
1552 timeout >>= 1;
1553 continue;
1554 }
1555 /* Timed out, enter rebinding state */
1556 log1("Entering rebinding state");
1557 state = REBINDING;
1558 /* fall right through */
1559 case REBINDING:
1560 /* Switch to bcast receive */
1561 change_listen_mode(LISTEN_RAW);
1562 /* Lease is *really* about to run out,
1563 * try to find DHCP server using broadcast */
1564 if (timeout > 0) {
1565 /* send a broadcast renew request */
1566 send_renew(xid, 0 /*INADDR_ANY*/, requested_ip);
1567 timeout >>= 1;
1568 continue;
1569 }
1570 /* Timed out, enter init state */
1571 bb_info_msg("Lease lost, entering init state");
1572 udhcp_run_script(NULL, "deconfig");
1573 state = INIT_SELECTING;
1574 client_config.first_secs = 0; /* make secs field count from 0 */
1575 /*timeout = 0; - already is */
1576 packet_num = 0;
1577 continue;
1578 /* case RELEASED: */
1579 }
1580 /* yah, I know, *you* say it would never happen */
1581 timeout = INT_MAX;
1582 continue; /* back to main loop */
1583 } /* if select timed out */
1584
1585 /* select() didn't timeout, something happened */
1586
1587 /* Is it a signal? */
1588 /* note: udhcp_sp_read checks FD_ISSET before reading */
1589 switch (udhcp_sp_read(&rfds)) {
1590 case SIGUSR1:
1591 client_config.first_secs = 0; /* make secs field count from 0 */
1592 // already_waited_sec = 0; /* shibby - this broke tomato renew button */
1593 perform_renew();
1594 if (state == RENEW_REQUESTED)
1595 // if (timeout > tryagain_timeout) /* shibby - this broke tomato renew button */
1596 // timeout = tryagain_timeout; /* shibby - this broke tomato renew button */
1597 goto case_RENEW_REQUESTED;
1598 /* Start things over */
1599 packet_num = 0;
1600 /* Kill any timeouts, user wants this to hurry along */
1601 timeout = 0;
1602 continue;
1603 case SIGUSR2:
1604 perform_release(server_addr, requested_ip);
1605 timeout = INT_MAX;
1606 continue;
1607 case SIGTERM:
1608 bb_info_msg("Received SIGTERM");
1609 goto ret0;
1610 }
1611
1612 /* Is it a packet? */
1613 if (listen_mode == LISTEN_NONE || !FD_ISSET(sockfd, &rfds))
1614 continue; /* no */
1615
1616 {
1617 int len;
1618
1619 /* A packet is ready, read it */
1620 if (listen_mode == LISTEN_KERNEL)
1621 len = udhcp_recv_kernel_packet(&packet, sockfd);
1622 else
1623 len = udhcp_recv_raw_packet(&packet, sockfd);
1624 if (len == -1) {
1625 /* Error is severe, reopen socket */
1626 bb_info_msg("Read error: %s, reopening socket", strerror(errno));
1627 sleep(discover_timeout); /* 3 seconds by default */
1628 change_listen_mode(listen_mode); /* just close and reopen */
1629 }
1630 /* If this packet will turn out to be unrelated/bogus,
1631 * we will go back and wait for next one.
1632 * Be sure timeout is properly decreased. */
1633 already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait;
1634 if (len < 0)
1635 continue;
1636 }
1637
1638 if (packet.xid != xid) {
1639 log1("xid %x (our is %x), ignoring packet",
1640 (unsigned)packet.xid, (unsigned)xid);
1641 continue;
1642 }
1643
1644 /* Ignore packets that aren't for us */
1645 if (packet.hlen != 6
1646 || memcmp(packet.chaddr, client_config.client_mac, 6) != 0
1647 ) {
1648 //FIXME: need to also check that last 10 bytes are zero
1649 log1("chaddr does not match, ignoring packet"); // log2?
1650 continue;
1651 }
1652
1653 message = udhcp_get_option(&packet, DHCP_MESSAGE_TYPE);
1654 if (message == NULL) {
1655 bb_error_msg("no message type option, ignoring packet");
1656 continue;
1657 }
1658
1659 switch (state) {
1660 case INIT_SELECTING:
1661 /* Must be a DHCPOFFER */
1662 if (*message == DHCPOFFER) {
1663 uint8_t *temp;
1664
1665 /* What exactly is server's IP? There are several values.
1666 * Example DHCP offer captured with tchdump:
1667 *
1668 * 10.34.25.254:67 > 10.34.25.202:68 // IP header's src
1669 * BOOTP fields:
1670 * Your-IP 10.34.25.202
1671 * Server-IP 10.34.32.125 // "next server" IP
1672 * Gateway-IP 10.34.25.254 // relay's address (if DHCP relays are in use)
1673 * DHCP options:
1674 * DHCP-Message Option 53, length 1: Offer
1675 * Server-ID Option 54, length 4: 10.34.255.7 // "server ID"
1676 * Default-Gateway Option 3, length 4: 10.34.25.254 // router
1677 *
1678 * We think that real server IP (one to use in renew/release)
1679 * is one in Server-ID option. But I am not 100% sure.
1680 * IP header's src and Gateway-IP (same in this example)
1681 * might work too.
1682 * "Next server" and router are definitely wrong ones to use, though...
1683 */
1684 /* We used to ignore pcakets without DHCP_SERVER_ID.
1685 * I've got user reports from people who run "address-less" servers.
1686 * They either supply DHCP_SERVER_ID of 0.0.0.0 or don't supply it at all.
1687 * They say ISC DHCP client supports this case.
1688 */
1689 server_addr = 0;
1690 temp = udhcp_get_option(&packet, DHCP_SERVER_ID);
1691 if (!temp) {
1692 bb_error_msg("no server ID, using 0.0.0.0");
1693 } else {
1694 /* it IS unaligned sometimes, don't "optimize" */
1695 move_from_unaligned32(server_addr, temp);
1696 }
1697 /*xid = packet.xid; - already is */
1698 requested_ip = packet.yiaddr;
1699
1700 /* enter requesting state */
1701 state = REQUESTING;
1702 timeout = 0;
1703 packet_num = 0;
1704 already_waited_sec = 0;
1705 }
1706 continue;
1707 case REQUESTING:
1708 case RENEWING:
1709 case RENEW_REQUESTED:
1710 case REBINDING:
1711 if (*message == DHCPACK) {
1712 unsigned start;
1713 uint32_t lease_seconds;
1714 struct in_addr temp_addr;
1715 uint8_t *temp;
1716
1717 temp = udhcp_get_option(&packet, DHCP_LEASE_TIME);
1718 if (!temp) {
1719 bb_error_msg("no lease time with ACK, using 1 hour lease");
1720 lease_seconds = 60 * 60;
1721 } else {
1722 /* it IS unaligned sometimes, don't "optimize" */
1723 move_from_unaligned32(lease_seconds, temp);
1724 lease_seconds = ntohl(lease_seconds);
1725 /* paranoia: must not be too small and not prone to overflows */
1726 if (lease_seconds < 0x10)
1727 lease_seconds = 0x10;
1728 if (lease_seconds >= 0x10000000)
1729 lease_seconds = 0x0fffffff;
1730 }
1731 #if ENABLE_FEATURE_UDHCPC_ARPING
1732 if (opt & OPT_a) {
1733 /* RFC 2131 3.1 paragraph 5:
1734 * "The client receives the DHCPACK message with configuration
1735 * parameters. The client SHOULD perform a final check on the
1736 * parameters (e.g., ARP for allocated network address), and notes
1737 * the duration of the lease specified in the DHCPACK message. At this
1738 * point, the client is configured. If the client detects that the
1739 * address is already in use (e.g., through the use of ARP),
1740 * the client MUST send a DHCPDECLINE message to the server and restarts
1741 * the configuration process..." */
1742 if (!arpping(packet.yiaddr,
1743 NULL,
1744 (uint32_t) 0,
1745 client_config.client_mac,
1746 client_config.interface,
1747 arpping_ms)
1748 ) {
1749 bb_info_msg("Offered address is in use "
1750 "(got ARP reply), declining");
1751 send_decline(/*xid,*/ server_addr, packet.yiaddr);
1752
1753 if (state != REQUESTING)
1754 udhcp_run_script(NULL, "deconfig");
1755 change_listen_mode(LISTEN_RAW);
1756 state = INIT_SELECTING;
1757 client_config.first_secs = 0; /* make secs field count from 0 */
1758 requested_ip = 0;
1759 timeout = tryagain_timeout;
1760 packet_num = 0;
1761 already_waited_sec = 0;
1762 continue; /* back to main loop */
1763 }
1764 }
1765 #endif
1766 /* enter bound state */
1767 timeout = lease_seconds / 2;
1768 temp_addr.s_addr = packet.yiaddr;
1769 bb_info_msg("Lease of %s obtained, lease time %u",
1770 inet_ntoa(temp_addr), (unsigned)lease_seconds);
1771 requested_ip = packet.yiaddr;
1772
1773 start = monotonic_sec();
1774 udhcp_run_script(&packet, state == REQUESTING ? "bound" : "renew");
1775 already_waited_sec = (unsigned)monotonic_sec() - start;
1776
1777 state = BOUND;
1778 change_listen_mode(LISTEN_NONE);
1779 if (opt & OPT_q) { /* quit after lease */
1780 goto ret0;
1781 }
1782 /* future renew failures should not exit (JM) */
1783 opt &= ~OPT_n;
1784 #if BB_MMU /* NOMMU case backgrounded earlier */
1785 if (!(opt & OPT_f)) {
1786 client_background();
1787 /* do not background again! */
1788 opt = ((opt & ~OPT_b) | OPT_f);
1789 }
1790 #endif
1791 /* make future renew packets use different xid */
1792 /* xid = random_xid(); ...but why bother? */
1793
1794 continue; /* back to main loop */
1795 }
1796 if (*message == DHCPNAK) {
1797 /* If network has more than one DHCP server,
1798 * "wrong" server can reply first, with a NAK.
1799 * Do not interpret it as a NAK from "our" server.
1800 */
1801 if (server_addr != 0) {
1802 uint32_t svid;
1803 uint8_t *temp;
1804
1805 temp = udhcp_get_option(&packet, DHCP_SERVER_ID);
1806 if (!temp) {
1807 non_matching_svid:
1808 log1("%s with wrong server ID, ignoring packet",
1809 "Received DHCP NAK"
1810 );
1811 continue;
1812 }
1813 move_from_unaligned32(svid, temp);
1814 if (svid != server_addr)
1815 goto non_matching_svid;
1816 }
1817 /* return to init state */
1818 bb_info_msg("Received DHCP NAK");
1819 udhcp_run_script(&packet, "nak");
1820 if (state != REQUESTING)
1821 udhcp_run_script(NULL, "deconfig");
1822 change_listen_mode(LISTEN_RAW);
1823 sleep(3); /* avoid excessive network traffic */
1824 state = INIT_SELECTING;
1825 client_config.first_secs = 0; /* make secs field count from 0 */
1826 requested_ip = 0;
1827 timeout = 0;
1828 packet_num = 0;
1829 already_waited_sec = 0;
1830 }
1831 continue;
1832 /* case BOUND: - ignore all packets */
1833 /* case RELEASED: - ignore all packets */
1834 }
1835 /* back to main loop */
1836 } /* for (;;) - main loop ends */
1837
1838 ret0:
1839 if (opt & OPT_R) /* release on quit */
1840 perform_release(server_addr, requested_ip);
1841 retval = 0;
1842 ret:
1843 /*if (client_config.pidfile) - remove_pidfile has its own check */
1844 remove_pidfile(client_config.pidfile);
1845 return retval;
1846 }
Tomato firmware and modifications.