source: MondoRescue/branches/2.2.9/mindi-busybox/networking/udhcp/common.c@ 3320

Last change on this file since 3320 was 3320, checked in by Bruno Cornec, 9 years ago
  • Re-add (thanks git BTW) the 2.2.9 branch which had been destroyed in the move to 3.0
  • Property svn:eol-style set to native
File size: 17.1 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001
4 *
5 * Licensed under GPLv2, see file LICENSE in this source tree.
6 */
7#include "common.h"
8
9#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
10unsigned dhcp_verbose;
11#endif
12
13const uint8_t MAC_BCAST_ADDR[6] ALIGN2 = {
14 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
15};
16
17/* Supported options are easily added here.
18 * See RFC2132 for more options.
19 * OPTION_REQ: these options are requested by udhcpc (unless -o).
20 */
21const struct dhcp_optflag dhcp_optflags[] = {
22 /* flags code */
23 { OPTION_IP | OPTION_REQ, 0x01 }, /* DHCP_SUBNET */
24 { OPTION_S32 , 0x02 }, /* DHCP_TIME_OFFSET */
25 { OPTION_IP | OPTION_LIST | OPTION_REQ, 0x03 }, /* DHCP_ROUTER */
26// { OPTION_IP | OPTION_LIST , 0x04 }, /* DHCP_TIME_SERVER */
27// { OPTION_IP | OPTION_LIST , 0x05 }, /* DHCP_NAME_SERVER */
28 { OPTION_IP | OPTION_LIST | OPTION_REQ, 0x06 }, /* DHCP_DNS_SERVER */
29// { OPTION_IP | OPTION_LIST , 0x07 }, /* DHCP_LOG_SERVER */
30// { OPTION_IP | OPTION_LIST , 0x08 }, /* DHCP_COOKIE_SERVER */
31 { OPTION_IP | OPTION_LIST , 0x09 }, /* DHCP_LPR_SERVER */
32 { OPTION_STRING | OPTION_REQ, 0x0c }, /* DHCP_HOST_NAME */
33 { OPTION_U16 , 0x0d }, /* DHCP_BOOT_SIZE */
34 { OPTION_STRING | OPTION_REQ, 0x0f }, /* DHCP_DOMAIN_NAME */
35 { OPTION_IP , 0x10 }, /* DHCP_SWAP_SERVER */
36 { OPTION_STRING , 0x11 }, /* DHCP_ROOT_PATH */
37 { OPTION_U8 , 0x17 }, /* DHCP_IP_TTL */
38 { OPTION_U16 , 0x1a }, /* DHCP_MTU */
39 { OPTION_IP | OPTION_REQ, 0x1c }, /* DHCP_BROADCAST */
40 { OPTION_IP_PAIR | OPTION_LIST , 0x21 }, /* DHCP_ROUTES */
41 { OPTION_STRING , 0x28 }, /* DHCP_NIS_DOMAIN */
42 { OPTION_IP | OPTION_LIST , 0x29 }, /* DHCP_NIS_SERVER */
43 { OPTION_IP | OPTION_LIST | OPTION_REQ, 0x2a }, /* DHCP_NTP_SERVER */
44 { OPTION_IP | OPTION_LIST , 0x2c }, /* DHCP_WINS_SERVER */
45 { OPTION_U32 , 0x33 }, /* DHCP_LEASE_TIME */
46 { OPTION_IP , 0x36 }, /* DHCP_SERVER_ID */
47 { OPTION_STRING , 0x38 }, /* DHCP_ERR_MESSAGE */
48//TODO: must be combined with 'sname' and 'file' handling:
49 { OPTION_STRING , 0x42 }, /* DHCP_TFTP_SERVER_NAME */
50 { OPTION_STRING , 0x43 }, /* DHCP_BOOT_FILE */
51//TODO: not a string, but a set of LASCII strings:
52// { OPTION_STRING , 0x4D }, /* DHCP_USER_CLASS */
53#if ENABLE_FEATURE_UDHCP_RFC3397
54 { OPTION_DNS_STRING | OPTION_LIST , 0x77 }, /* DHCP_DOMAIN_SEARCH */
55 { OPTION_SIP_SERVERS , 0x78 }, /* DHCP_SIP_SERVERS */
56#endif
57 { OPTION_STATIC_ROUTES , 0x79 }, /* DHCP_STATIC_ROUTES */
58 { OPTION_STATIC_ROUTES , 0xf9 }, /* DHCP_MS_STATIC_ROUTES */
59 { OPTION_STRING , 0xfc }, /* DHCP_WPAD */
60
61 /* Options below have no match in dhcp_option_strings[],
62 * are not passed to dhcpc scripts, and cannot be specified
63 * with "option XXX YYY" syntax in dhcpd config file.
64 * These entries are only used internally by udhcp[cd]
65 * to correctly encode options into packets.
66 */
67
68 { OPTION_IP , 0x32 }, /* DHCP_REQUESTED_IP */
69 { OPTION_U8 , 0x35 }, /* DHCP_MESSAGE_TYPE */
70 { OPTION_U16 , 0x39 }, /* DHCP_MAX_SIZE */
71//looks like these opts will work just fine even without these defs:
72// { OPTION_STRING , 0x3c }, /* DHCP_VENDOR */
73// /* not really a string: */
74// { OPTION_STRING , 0x3d }, /* DHCP_CLIENT_ID */
75 { 0, 0 } /* zeroed terminating entry */
76};
77
78/* Used for converting options from incoming packets to env variables
79 * for udhcpc stript, and for setting options for udhcpd via
80 * "opt OPTION_NAME OPTION_VALUE" directives in udhcpd.conf file.
81 */
82/* Must match dhcp_optflags[] order */
83const char dhcp_option_strings[] ALIGN1 =
84 "subnet" "\0" /* DHCP_SUBNET */
85 "timezone" "\0" /* DHCP_TIME_OFFSET */
86 "router" "\0" /* DHCP_ROUTER */
87// "timesrv" "\0" /* DHCP_TIME_SERVER */
88// "namesrv" "\0" /* DHCP_NAME_SERVER */
89 "dns" "\0" /* DHCP_DNS_SERVER */
90// "logsrv" "\0" /* DHCP_LOG_SERVER */
91// "cookiesrv" "\0" /* DHCP_COOKIE_SERVER */
92 "lprsrv" "\0" /* DHCP_LPR_SERVER */
93 "hostname" "\0" /* DHCP_HOST_NAME */
94 "bootsize" "\0" /* DHCP_BOOT_SIZE */
95 "domain" "\0" /* DHCP_DOMAIN_NAME */
96 "swapsrv" "\0" /* DHCP_SWAP_SERVER */
97 "rootpath" "\0" /* DHCP_ROOT_PATH */
98 "ipttl" "\0" /* DHCP_IP_TTL */
99 "mtu" "\0" /* DHCP_MTU */
100 "broadcast" "\0" /* DHCP_BROADCAST */
101 "routes" "\0" /* DHCP_ROUTES */
102 "nisdomain" "\0" /* DHCP_NIS_DOMAIN */
103 "nissrv" "\0" /* DHCP_NIS_SERVER */
104 "ntpsrv" "\0" /* DHCP_NTP_SERVER */
105 "wins" "\0" /* DHCP_WINS_SERVER */
106 "lease" "\0" /* DHCP_LEASE_TIME */
107 "serverid" "\0" /* DHCP_SERVER_ID */
108 "message" "\0" /* DHCP_ERR_MESSAGE */
109 "tftp" "\0" /* DHCP_TFTP_SERVER_NAME */
110 "bootfile" "\0" /* DHCP_BOOT_FILE */
111// "userclass" "\0" /* DHCP_USER_CLASS */
112#if ENABLE_FEATURE_UDHCP_RFC3397
113 "search" "\0" /* DHCP_DOMAIN_SEARCH */
114// doesn't work in udhcpd.conf since OPTION_SIP_SERVERS
115// is not handled yet by "string->option" conversion code:
116 "sipsrv" "\0" /* DHCP_SIP_SERVERS */
117#endif
118// doesn't work in udhcpd.conf since OPTION_STATIC_ROUTES
119// is not handled yet by "string->option" conversion code:
120 "staticroutes" "\0"/* DHCP_STATIC_ROUTES */
121 "msstaticroutes""\0"/* DHCP_MS_STATIC_ROUTES */
122 "wpad" "\0" /* DHCP_WPAD */
123 ;
124
125/* Lengths of the option types in binary form.
126 * Used by:
127 * udhcp_str2optset: to determine how many bytes to allocate.
128 * xmalloc_optname_optval: to estimate string length
129 * from binary option length: (option[LEN] / dhcp_option_lengths[opt_type])
130 * is the number of elements, multiply in by one element's string width
131 * (len_of_option_as_string[opt_type]) and you know how wide string you need.
132 */
133const uint8_t dhcp_option_lengths[] ALIGN1 = {
134 [OPTION_IP] = 4,
135 [OPTION_IP_PAIR] = 8,
136// [OPTION_BOOLEAN] = 1,
137 [OPTION_STRING] = 1, /* ignored by udhcp_str2optset */
138#if ENABLE_FEATURE_UDHCP_RFC3397
139 [OPTION_DNS_STRING] = 1, /* ignored by both udhcp_str2optset and xmalloc_optname_optval */
140 [OPTION_SIP_SERVERS] = 1,
141#endif
142 [OPTION_U8] = 1,
143 [OPTION_U16] = 2,
144// [OPTION_S16] = 2,
145 [OPTION_U32] = 4,
146 [OPTION_S32] = 4,
147 /* Just like OPTION_STRING, we use minimum length here */
148 [OPTION_STATIC_ROUTES] = 5,
149};
150
151
152#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 2
153static void log_option(const char *pfx, const uint8_t *opt)
154{
155 if (dhcp_verbose >= 2) {
156 char buf[256 * 2 + 2];
157 *bin2hex(buf, (void*) (opt + OPT_DATA), opt[OPT_LEN]) = '\0';
158 bb_info_msg("%s: 0x%02x %s", pfx, opt[OPT_CODE], buf);
159 }
160}
161#else
162# define log_option(pfx, opt) ((void)0)
163#endif
164
165unsigned FAST_FUNC udhcp_option_idx(const char *name)
166{
167 int n = index_in_strings(dhcp_option_strings, name);
168 if (n >= 0)
169 return n;
170
171 {
172 char buf[sizeof(dhcp_option_strings)];
173 char *d = buf;
174 const char *s = dhcp_option_strings;
175 while (s < dhcp_option_strings + sizeof(dhcp_option_strings) - 2) {
176 *d++ = (*s == '\0' ? ' ' : *s);
177 s++;
178 }
179 *d = '\0';
180 bb_error_msg_and_die("unknown option '%s', known options: %s", name, buf);
181 }
182}
183
184/* Get an option with bounds checking (warning, result is not aligned) */
185uint8_t* FAST_FUNC udhcp_get_option(struct dhcp_packet *packet, int code)
186{
187 uint8_t *optionptr;
188 int len;
189 int rem;
190 int overload = 0;
191 enum {
192 FILE_FIELD101 = FILE_FIELD * 0x101,
193 SNAME_FIELD101 = SNAME_FIELD * 0x101,
194 };
195
196 /* option bytes: [code][len][data1][data2]..[dataLEN] */
197 optionptr = packet->options;
198 rem = sizeof(packet->options);
199 while (1) {
200 if (rem <= 0) {
201 bb_error_msg("bad packet, malformed option field");
202 return NULL;
203 }
204 if (optionptr[OPT_CODE] == DHCP_PADDING) {
205 rem--;
206 optionptr++;
207 continue;
208 }
209 if (optionptr[OPT_CODE] == DHCP_END) {
210 if ((overload & FILE_FIELD101) == FILE_FIELD) {
211 /* can use packet->file, and didn't look at it yet */
212 overload |= FILE_FIELD101; /* "we looked at it" */
213 optionptr = packet->file;
214 rem = sizeof(packet->file);
215 continue;
216 }
217 if ((overload & SNAME_FIELD101) == SNAME_FIELD) {
218 /* can use packet->sname, and didn't look at it yet */
219 overload |= SNAME_FIELD101; /* "we looked at it" */
220 optionptr = packet->sname;
221 rem = sizeof(packet->sname);
222 continue;
223 }
224 break;
225 }
226 len = 2 + optionptr[OPT_LEN];
227 rem -= len;
228 if (rem < 0)
229 continue; /* complain and return NULL */
230
231 if (optionptr[OPT_CODE] == code) {
232 log_option("Option found", optionptr);
233 return optionptr + OPT_DATA;
234 }
235
236 if (optionptr[OPT_CODE] == DHCP_OPTION_OVERLOAD) {
237 overload |= optionptr[OPT_DATA];
238 /* fall through */
239 }
240 optionptr += len;
241 }
242
243 /* log3 because udhcpc uses it a lot - very noisy */
244 log3("Option 0x%02x not found", code);
245 return NULL;
246}
247
248/* Return the position of the 'end' option (no bounds checking) */
249int FAST_FUNC udhcp_end_option(uint8_t *optionptr)
250{
251 int i = 0;
252
253 while (optionptr[i] != DHCP_END) {
254 if (optionptr[i] != DHCP_PADDING)
255 i += optionptr[i + OPT_LEN] + OPT_DATA-1;
256 i++;
257 }
258 return i;
259}
260
261/* Add an option (supplied in binary form) to the options.
262 * Option format: [code][len][data1][data2]..[dataLEN]
263 */
264void FAST_FUNC udhcp_add_binary_option(struct dhcp_packet *packet, uint8_t *addopt)
265{
266 unsigned len;
267 uint8_t *optionptr = packet->options;
268 unsigned end = udhcp_end_option(optionptr);
269
270 len = OPT_DATA + addopt[OPT_LEN];
271 /* end position + (option code/length + addopt length) + end option */
272 if (end + len + 1 >= DHCP_OPTIONS_BUFSIZE) {
273//TODO: learn how to use overflow option if we exhaust packet->options[]
274 bb_error_msg("option 0x%02x did not fit into the packet",
275 addopt[OPT_CODE]);
276 return;
277 }
278 log_option("Adding option", addopt);
279 memcpy(optionptr + end, addopt, len);
280 optionptr[end + len] = DHCP_END;
281}
282
283/* Add an one to four byte option to a packet */
284void FAST_FUNC udhcp_add_simple_option(struct dhcp_packet *packet, uint8_t code, uint32_t data)
285{
286 const struct dhcp_optflag *dh;
287
288 for (dh = dhcp_optflags; dh->code; dh++) {
289 if (dh->code == code) {
290 uint8_t option[6], len;
291
292 option[OPT_CODE] = code;
293 len = dhcp_option_lengths[dh->flags & OPTION_TYPE_MASK];
294 option[OPT_LEN] = len;
295 if (BB_BIG_ENDIAN)
296 data <<= 8 * (4 - len);
297 /* Assignment is unaligned! */
298 move_to_unaligned32(&option[OPT_DATA], data);
299 udhcp_add_binary_option(packet, option);
300 return;
301 }
302 }
303
304 bb_error_msg("can't add option 0x%02x", code);
305}
306
307/* Find option 'code' in opt_list */
308struct option_set* FAST_FUNC udhcp_find_option(struct option_set *opt_list, uint8_t code)
309{
310 while (opt_list && opt_list->data[OPT_CODE] < code)
311 opt_list = opt_list->next;
312
313 if (opt_list && opt_list->data[OPT_CODE] == code)
314 return opt_list;
315 return NULL;
316}
317
318/* Parse string to IP in network order */
319int FAST_FUNC udhcp_str2nip(const char *str, void *arg)
320{
321 len_and_sockaddr *lsa;
322
323 lsa = host_and_af2sockaddr(str, 0, AF_INET);
324 if (!lsa)
325 return 0;
326 *(uint32_t*)arg = lsa->u.sin.sin_addr.s_addr;
327 free(lsa);
328 return 1;
329}
330
331/* udhcp_str2optset:
332 * Parse string option representation to binary form and add it to opt_list.
333 * Called to parse "udhcpc -x OPTNAME:OPTVAL"
334 * and to parse udhcpd.conf's "opt OPTNAME OPTVAL" directives.
335 */
336/* helper for the helper */
337static char *allocate_tempopt_if_needed(
338 const struct dhcp_optflag *optflag,
339 char *buffer,
340 int *length_p)
341{
342 char *allocated = NULL;
343 if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_BIN) {
344 const char *end;
345 allocated = xstrdup(buffer); /* more than enough */
346 end = hex2bin(allocated, buffer, 255);
347 if (errno)
348 bb_error_msg_and_die("malformed hex string '%s'", buffer);
349 *length_p = end - allocated;
350 }
351 return allocated;
352}
353/* helper: add an option to the opt_list */
354static NOINLINE void attach_option(
355 struct option_set **opt_list,
356 const struct dhcp_optflag *optflag,
357 char *buffer,
358 int length)
359{
360 struct option_set *existing, *new, **curr;
361 char *allocated = NULL;
362
363 existing = udhcp_find_option(*opt_list, optflag->code);
364 if (!existing) {
365 log2("Attaching option %02x to list", optflag->code);
366 allocated = allocate_tempopt_if_needed(optflag, buffer, &length);
367#if ENABLE_FEATURE_UDHCP_RFC3397
368 if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_DNS_STRING) {
369 /* reuse buffer and length for RFC1035-formatted string */
370 allocated = buffer = (char *)dname_enc(NULL, 0, buffer, &length);
371 }
372#endif
373 /* make a new option */
374 new = xmalloc(sizeof(*new));
375 new->data = xmalloc(length + OPT_DATA);
376 new->data[OPT_CODE] = optflag->code;
377 new->data[OPT_LEN] = length;
378 memcpy(new->data + OPT_DATA, (allocated ? allocated : buffer), length);
379
380 curr = opt_list;
381 while (*curr && (*curr)->data[OPT_CODE] < optflag->code)
382 curr = &(*curr)->next;
383
384 new->next = *curr;
385 *curr = new;
386 goto ret;
387 }
388
389 if (optflag->flags & OPTION_LIST) {
390 unsigned old_len;
391
392 /* add it to an existing option */
393 log2("Attaching option %02x to existing member of list", optflag->code);
394 allocated = allocate_tempopt_if_needed(optflag, buffer, &length);
395 old_len = existing->data[OPT_LEN];
396#if ENABLE_FEATURE_UDHCP_RFC3397
397 if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_DNS_STRING) {
398 /* reuse buffer and length for RFC1035-formatted string */
399 allocated = buffer = (char *)dname_enc(existing->data + OPT_DATA, old_len, buffer, &length);
400 }
401#endif
402 if (old_len + length < 255) {
403 /* actually 255 is ok too, but adding a space can overlow it */
404
405 existing->data = xrealloc(existing->data, OPT_DATA + 1 + old_len + length);
406 if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_STRING) {
407 /* add space separator between STRING options in a list */
408 existing->data[OPT_DATA + old_len] = ' ';
409 old_len++;
410 }
411 memcpy(existing->data + OPT_DATA + old_len, buffer, length);
412 existing->data[OPT_LEN] = old_len + length;
413 } /* else, ignore the data, we could put this in a second option in the future */
414 } /* else, ignore the new data */
415
416 ret:
417 free(allocated);
418}
419
420int FAST_FUNC udhcp_str2optset(const char *const_str, void *arg)
421{
422 struct option_set **opt_list = arg;
423 char *opt, *val, *endptr;
424 char *str;
425 const struct dhcp_optflag *optflag;
426 struct dhcp_optflag bin_optflag;
427 unsigned optcode;
428 int retval, length;
429 char buffer[8] ALIGNED(4);
430 uint16_t *result_u16 = (uint16_t *) buffer;
431 uint32_t *result_u32 = (uint32_t *) buffer;
432
433 /* Cheat, the only *const* str possible is "" */
434 str = (char *) const_str;
435 opt = strtok(str, " \t=");
436 if (!opt)
437 return 0;
438
439 optcode = bb_strtou(opt, NULL, 0);
440 if (!errno && optcode < 255) {
441 /* Raw (numeric) option code */
442 bin_optflag.flags = OPTION_BIN;
443 bin_optflag.code = optcode;
444 optflag = &bin_optflag;
445 } else {
446 optflag = &dhcp_optflags[udhcp_option_idx(opt)];
447 }
448
449 retval = 0;
450 do {
451 val = strtok(NULL, ", \t");
452 if (!val)
453 break;
454 length = dhcp_option_lengths[optflag->flags & OPTION_TYPE_MASK];
455 retval = 0;
456 opt = buffer; /* new meaning for variable opt */
457 switch (optflag->flags & OPTION_TYPE_MASK) {
458 case OPTION_IP:
459 retval = udhcp_str2nip(val, buffer);
460 break;
461 case OPTION_IP_PAIR:
462 retval = udhcp_str2nip(val, buffer);
463 val = strtok(NULL, ", \t/-");
464 if (!val)
465 retval = 0;
466 if (retval)
467 retval = udhcp_str2nip(val, buffer + 4);
468 break;
469 case OPTION_STRING:
470#if ENABLE_FEATURE_UDHCP_RFC3397
471 case OPTION_DNS_STRING:
472#endif
473 length = strnlen(val, 254);
474 if (length > 0) {
475 opt = val;
476 retval = 1;
477 }
478 break;
479// case OPTION_BOOLEAN: {
480// static const char no_yes[] ALIGN1 = "no\0yes\0";
481// buffer[0] = retval = index_in_strings(no_yes, val);
482// retval++; /* 0 - bad; 1: "no" 2: "yes" */
483// break;
484// }
485 case OPTION_U8:
486 buffer[0] = strtoul(val, &endptr, 0);
487 retval = (endptr[0] == '\0');
488 break;
489 /* htonX are macros in older libc's, using temp var
490 * in code below for safety */
491 /* TODO: use bb_strtoX? */
492 case OPTION_U16: {
493 unsigned long tmp = strtoul(val, &endptr, 0);
494 *result_u16 = htons(tmp);
495 retval = (endptr[0] == '\0' /*&& tmp < 0x10000*/);
496 break;
497 }
498// case OPTION_S16: {
499// long tmp = strtol(val, &endptr, 0);
500// *result_u16 = htons(tmp);
501// retval = (endptr[0] == '\0');
502// break;
503// }
504 case OPTION_U32: {
505 unsigned long tmp = strtoul(val, &endptr, 0);
506 *result_u32 = htonl(tmp);
507 retval = (endptr[0] == '\0');
508 break;
509 }
510 case OPTION_S32: {
511 long tmp = strtol(val, &endptr, 0);
512 *result_u32 = htonl(tmp);
513 retval = (endptr[0] == '\0');
514 break;
515 }
516 case OPTION_BIN: /* handled in attach_option() */
517 opt = val;
518 retval = 1;
519 default:
520 break;
521 }
522 if (retval)
523 attach_option(opt_list, optflag, opt, length);
524 } while (retval && optflag->flags & OPTION_LIST);
525
526 return retval;
527}
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