1 /* vi: set sw=4 ts=4: */
3 * Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001
5 * Licensed under GPLv2, see file LICENSE in this source tree.
9 #if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
10 unsigned dhcp_verbose;
13 const uint8_t MAC_BCAST_ADDR[6] ALIGN2 = {
14 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
17 /* Supported options are easily added here.
18 * See RFC2132 for more options.
19 * OPTION_REQ: these options are requested by udhcpc (unless -o).
21 const struct dhcp_optflag dhcp_optflags[] = {
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_HOST | OPTION_REQ, 0x0c }, /* DHCP_HOST_NAME */
33 { OPTION_U16 , 0x0d }, /* DHCP_BOOT_SIZE */
34 { OPTION_STRING_HOST | 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 //TODO: why do we request DHCP_BROADCAST? Can't we assume that
40 //in the unlikely case it is different from typical N.N.255.255,
41 //server would let us know anyway?
42 { OPTION_IP | OPTION_REQ, 0x1c }, /* DHCP_BROADCAST */
43 { OPTION_IP_PAIR | OPTION_LIST , 0x21 }, /* DHCP_ROUTES */
44 { OPTION_STRING_HOST , 0x28 }, /* DHCP_NIS_DOMAIN */
45 { OPTION_IP | OPTION_LIST , 0x29 }, /* DHCP_NIS_SERVER */
46 { OPTION_IP | OPTION_LIST | OPTION_REQ, 0x2a }, /* DHCP_NTP_SERVER */
47 { OPTION_IP | OPTION_LIST , 0x2c }, /* DHCP_WINS_SERVER */
48 { OPTION_U32 , 0x33 }, /* DHCP_LEASE_TIME */
49 { OPTION_IP , 0x36 }, /* DHCP_SERVER_ID */
50 { OPTION_STRING , 0x38 }, /* DHCP_ERR_MESSAGE */
51 //TODO: must be combined with 'sname' and 'file' handling:
52 { OPTION_STRING_HOST , 0x42 }, /* DHCP_TFTP_SERVER_NAME */
53 { OPTION_STRING , 0x43 }, /* DHCP_BOOT_FILE */
54 //TODO: not a string, but a set of LASCII strings:
55 // { OPTION_STRING , 0x4D }, /* DHCP_USER_CLASS */
56 #if ENABLE_FEATURE_UDHCP_RFC3397
57 { OPTION_DNS_STRING | OPTION_LIST , 0x77 }, /* DHCP_DOMAIN_SEARCH */
58 { OPTION_SIP_SERVERS , 0x78 }, /* DHCP_SIP_SERVERS */
60 { OPTION_STATIC_ROUTES | OPTION_LIST , 0x79 }, /* DHCP_STATIC_ROUTES */
61 #if ENABLE_FEATURE_UDHCP_8021Q
62 { OPTION_U16 , 0x84 }, /* DHCP_VLAN_ID */
63 { OPTION_U8 , 0x85 }, /* DHCP_VLAN_PRIORITY */
65 { OPTION_STRING , 0xd1 }, /* DHCP_PXE_CONF_FILE */
66 { OPTION_6RD , 0xd4 }, /* DHCP_6RD */
67 { OPTION_STATIC_ROUTES | OPTION_LIST , 0xf9 }, /* DHCP_MS_STATIC_ROUTES */
68 { OPTION_STRING , 0xfc }, /* DHCP_WPAD */
70 /* Options below have no match in dhcp_option_strings[],
71 * are not passed to dhcpc scripts, and cannot be specified
72 * with "option XXX YYY" syntax in dhcpd config file.
73 * These entries are only used internally by udhcp[cd]
74 * to correctly encode options into packets.
77 { OPTION_IP , 0x32 }, /* DHCP_REQUESTED_IP */
78 { OPTION_U8 , 0x35 }, /* DHCP_MESSAGE_TYPE */
79 { OPTION_U16 , 0x39 }, /* DHCP_MAX_SIZE */
80 //looks like these opts will work just fine even without these defs:
81 // { OPTION_STRING , 0x3c }, /* DHCP_VENDOR */
82 // /* not really a string: */
83 // { OPTION_STRING , 0x3d }, /* DHCP_CLIENT_ID */
84 { 0, 0 } /* zeroed terminating entry */
87 /* Used for converting options from incoming packets to env variables
88 * for udhcpc stript, and for setting options for udhcpd via
89 * "opt OPTION_NAME OPTION_VALUE" directives in udhcpd.conf file.
91 /* Must match dhcp_optflags[] order */
92 const char dhcp_option_strings[] ALIGN1 =
93 "subnet" "\0" /* DHCP_SUBNET */
94 "timezone" "\0" /* DHCP_TIME_OFFSET */
95 "router" "\0" /* DHCP_ROUTER */
96 // "timesrv" "\0" /* DHCP_TIME_SERVER */
97 // "namesrv" "\0" /* DHCP_NAME_SERVER */
98 "dns" "\0" /* DHCP_DNS_SERVER */
99 // "logsrv" "\0" /* DHCP_LOG_SERVER */
100 // "cookiesrv" "\0" /* DHCP_COOKIE_SERVER */
101 "lprsrv" "\0" /* DHCP_LPR_SERVER */
102 "hostname" "\0" /* DHCP_HOST_NAME */
103 "bootsize" "\0" /* DHCP_BOOT_SIZE */
104 "domain" "\0" /* DHCP_DOMAIN_NAME */
105 "swapsrv" "\0" /* DHCP_SWAP_SERVER */
106 "rootpath" "\0" /* DHCP_ROOT_PATH */
107 "ipttl" "\0" /* DHCP_IP_TTL */
108 "mtu" "\0" /* DHCP_MTU */
109 "broadcast" "\0" /* DHCP_BROADCAST */
110 "routes" "\0" /* DHCP_ROUTES */
111 "nisdomain" "\0" /* DHCP_NIS_DOMAIN */
112 "nissrv" "\0" /* DHCP_NIS_SERVER */
113 "ntpsrv" "\0" /* DHCP_NTP_SERVER */
114 "wins" "\0" /* DHCP_WINS_SERVER */
115 "lease" "\0" /* DHCP_LEASE_TIME */
116 "serverid" "\0" /* DHCP_SERVER_ID */
117 "message" "\0" /* DHCP_ERR_MESSAGE */
118 "tftp" "\0" /* DHCP_TFTP_SERVER_NAME */
119 "bootfile" "\0" /* DHCP_BOOT_FILE */
120 // "userclass" "\0" /* DHCP_USER_CLASS */
121 #if ENABLE_FEATURE_UDHCP_RFC3397
122 "search" "\0" /* DHCP_DOMAIN_SEARCH */
123 // doesn't work in udhcpd.conf since OPTION_SIP_SERVERS
124 // is not handled yet by "string->option" conversion code:
125 "sipsrv" "\0" /* DHCP_SIP_SERVERS */
127 "staticroutes" "\0"/* DHCP_STATIC_ROUTES */
128 #if ENABLE_FEATURE_UDHCP_8021Q
129 "vlanid" "\0" /* DHCP_VLAN_ID */
130 "vlanpriority" "\0"/* DHCP_VLAN_PRIORITY */
132 "pxeconffile" "\0" /* DHCP_PXE_CONF_FILE */
133 "ip6rd" "\0" /* DHCP_6RD */
134 "msstaticroutes""\0"/* DHCP_MS_STATIC_ROUTES */
135 "wpad" "\0" /* DHCP_WPAD */
138 /* Lengths of the option types in binary form.
140 * udhcp_str2optset: to determine how many bytes to allocate.
141 * xmalloc_optname_optval: to estimate string length
142 * from binary option length: (option[LEN] / dhcp_option_lengths[opt_type])
143 * is the number of elements, multiply in by one element's string width
144 * (len_of_option_as_string[opt_type]) and you know how wide string you need.
146 const uint8_t dhcp_option_lengths[] ALIGN1 = {
148 [OPTION_IP_PAIR] = 8,
149 // [OPTION_BOOLEAN] = 1,
150 [OPTION_STRING] = 1, /* ignored by udhcp_str2optset */
151 [OPTION_STRING_HOST] = 1, /* ignored by udhcp_str2optset */
152 #if ENABLE_FEATURE_UDHCP_RFC3397
153 [OPTION_DNS_STRING] = 1, /* ignored by both udhcp_str2optset and xmalloc_optname_optval */
154 [OPTION_SIP_SERVERS] = 1,
161 /* Just like OPTION_STRING, we use minimum length here */
162 [OPTION_STATIC_ROUTES] = 5,
163 [OPTION_6RD] = 22, /* ignored by udhcp_str2optset */
167 #if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 2
168 static void log_option(const char *pfx, const uint8_t *opt)
170 if (dhcp_verbose >= 2) {
171 char buf[256 * 2 + 2];
172 *bin2hex(buf, (void*) (opt + OPT_DATA), opt[OPT_LEN]) = '\0';
173 bb_info_msg("%s: 0x%02x %s", pfx, opt[OPT_CODE], buf);
177 # define log_option(pfx, opt) ((void)0)
180 unsigned FAST_FUNC udhcp_option_idx(const char *name)
182 int n = index_in_strings(dhcp_option_strings, name);
187 char buf[sizeof(dhcp_option_strings)];
189 const char *s = dhcp_option_strings;
190 while (s < dhcp_option_strings + sizeof(dhcp_option_strings) - 2) {
191 *d++ = (*s == '\0' ? ' ' : *s);
195 bb_error_msg_and_die("unknown option '%s', known options: %s", name, buf);
199 /* Get an option with bounds checking (warning, result is not aligned) */
200 uint8_t* FAST_FUNC udhcp_get_option(struct dhcp_packet *packet, int code)
207 FILE_FIELD101 = FILE_FIELD * 0x101,
208 SNAME_FIELD101 = SNAME_FIELD * 0x101,
211 /* option bytes: [code][len][data1][data2]..[dataLEN] */
212 optionptr = packet->options;
213 rem = sizeof(packet->options);
216 bb_error_msg("bad packet, malformed option field");
219 if (optionptr[OPT_CODE] == DHCP_PADDING) {
224 if (optionptr[OPT_CODE] == DHCP_END) {
225 if ((overload & FILE_FIELD101) == FILE_FIELD) {
226 /* can use packet->file, and didn't look at it yet */
227 overload |= FILE_FIELD101; /* "we looked at it" */
228 optionptr = packet->file;
229 rem = sizeof(packet->file);
232 if ((overload & SNAME_FIELD101) == SNAME_FIELD) {
233 /* can use packet->sname, and didn't look at it yet */
234 overload |= SNAME_FIELD101; /* "we looked at it" */
235 optionptr = packet->sname;
236 rem = sizeof(packet->sname);
241 len = 2 + optionptr[OPT_LEN];
244 continue; /* complain and return NULL */
246 if (optionptr[OPT_CODE] == code) {
247 log_option("Option found", optionptr);
248 return optionptr + OPT_DATA;
251 if (optionptr[OPT_CODE] == DHCP_OPTION_OVERLOAD) {
252 overload |= optionptr[OPT_DATA];
258 /* log3 because udhcpc uses it a lot - very noisy */
259 log3("Option 0x%02x not found", code);
263 /* Return the position of the 'end' option (no bounds checking) */
264 int FAST_FUNC udhcp_end_option(uint8_t *optionptr)
268 while (optionptr[i] != DHCP_END) {
269 if (optionptr[i] != DHCP_PADDING)
270 i += optionptr[i + OPT_LEN] + OPT_DATA-1;
276 /* Add an option (supplied in binary form) to the options.
277 * Option format: [code][len][data1][data2]..[dataLEN]
279 void FAST_FUNC udhcp_add_binary_option(struct dhcp_packet *packet, uint8_t *addopt)
282 uint8_t *optionptr = packet->options;
283 unsigned end = udhcp_end_option(optionptr);
285 len = OPT_DATA + addopt[OPT_LEN];
286 /* end position + (option code/length + addopt length) + end option */
287 if (end + len + 1 >= DHCP_OPTIONS_BUFSIZE) {
288 //TODO: learn how to use overflow option if we exhaust packet->options[]
289 bb_error_msg("option 0x%02x did not fit into the packet",
293 log_option("Adding option", addopt);
294 memcpy(optionptr + end, addopt, len);
295 optionptr[end + len] = DHCP_END;
298 /* Add an one to four byte option to a packet */
299 void FAST_FUNC udhcp_add_simple_option(struct dhcp_packet *packet, uint8_t code, uint32_t data)
301 const struct dhcp_optflag *dh;
303 for (dh = dhcp_optflags; dh->code; dh++) {
304 if (dh->code == code) {
305 uint8_t option[6], len;
307 option[OPT_CODE] = code;
308 len = dhcp_option_lengths[dh->flags & OPTION_TYPE_MASK];
309 option[OPT_LEN] = len;
311 data <<= 8 * (4 - len);
312 /* Assignment is unaligned! */
313 move_to_unaligned32(&option[OPT_DATA], data);
314 udhcp_add_binary_option(packet, option);
319 bb_error_msg("can't add option 0x%02x", code);
322 /* Find option 'code' in opt_list */
323 struct option_set* FAST_FUNC udhcp_find_option(struct option_set *opt_list, uint8_t code)
325 while (opt_list && opt_list->data[OPT_CODE] < code)
326 opt_list = opt_list->next;
328 if (opt_list && opt_list->data[OPT_CODE] == code)
333 /* Parse string to IP in network order */
334 int FAST_FUNC udhcp_str2nip(const char *str, void *arg)
336 len_and_sockaddr *lsa;
338 lsa = host_and_af2sockaddr(str, 0, AF_INET);
341 /* arg maybe unaligned */
342 move_to_unaligned32((uint32_t*)arg, lsa->u.sin.sin_addr.s_addr);
348 * Parse string option representation to binary form and add it to opt_list.
349 * Called to parse "udhcpc -x OPTNAME:OPTVAL"
350 * and to parse udhcpd.conf's "opt OPTNAME OPTVAL" directives.
352 /* helper for the helper */
353 static char *allocate_tempopt_if_needed(
354 const struct dhcp_optflag *optflag,
358 char *allocated = NULL;
359 if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_BIN) {
361 allocated = xstrdup(buffer); /* more than enough */
362 end = hex2bin(allocated, buffer, 255);
364 bb_error_msg_and_die("malformed hex string '%s'", buffer);
365 *length_p = end - allocated;
369 /* helper: add an option to the opt_list */
370 static NOINLINE void attach_option(
371 struct option_set **opt_list,
372 const struct dhcp_optflag *optflag,
376 struct option_set *existing;
379 allocated = allocate_tempopt_if_needed(optflag, buffer, &length);
380 #if ENABLE_FEATURE_UDHCP_RFC3397
381 if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_DNS_STRING) {
382 /* reuse buffer and length for RFC1035-formatted string */
383 allocated = buffer = (char *)dname_enc(NULL, 0, buffer, &length);
387 existing = udhcp_find_option(*opt_list, optflag->code);
389 struct option_set *new, **curr;
391 /* make a new option */
392 log2("Attaching option %02x to list", optflag->code);
393 new = xmalloc(sizeof(*new));
394 new->data = xmalloc(length + OPT_DATA);
395 new->data[OPT_CODE] = optflag->code;
396 new->data[OPT_LEN] = length;
397 memcpy(new->data + OPT_DATA, (allocated ? allocated : buffer), length);
400 while (*curr && (*curr)->data[OPT_CODE] < optflag->code)
401 curr = &(*curr)->next;
408 if (optflag->flags & OPTION_LIST) {
411 /* add it to an existing option */
412 log2("Attaching option %02x to existing member of list", optflag->code);
413 old_len = existing->data[OPT_LEN];
414 if (old_len + length < 255) {
415 /* actually 255 is ok too, but adding a space can overlow it */
417 existing->data = xrealloc(existing->data, OPT_DATA + 1 + old_len + length);
418 if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_STRING
419 || (optflag->flags & OPTION_TYPE_MASK) == OPTION_STRING_HOST
421 /* add space separator between STRING options in a list */
422 existing->data[OPT_DATA + old_len] = ' ';
425 memcpy(existing->data + OPT_DATA + old_len, (allocated ? allocated : buffer), length);
426 existing->data[OPT_LEN] = old_len + length;
427 } /* else, ignore the data, we could put this in a second option in the future */
428 } /* else, ignore the new data */
434 int FAST_FUNC udhcp_str2optset(const char *const_str, void *arg)
436 struct option_set **opt_list = arg;
439 const struct dhcp_optflag *optflag;
440 struct dhcp_optflag bin_optflag;
443 /* IP_PAIR needs 8 bytes, STATIC_ROUTES needs 9 max */
444 char buffer[9] ALIGNED(4);
445 uint16_t *result_u16 = (uint16_t *) buffer;
446 uint32_t *result_u32 = (uint32_t *) buffer;
448 /* Cheat, the only *const* str possible is "" */
449 str = (char *) const_str;
450 opt = strtok(str, " \t=");
454 optcode = bb_strtou(opt, NULL, 0);
455 if (!errno && optcode < 255) {
456 /* Raw (numeric) option code */
457 bin_optflag.flags = OPTION_BIN;
458 bin_optflag.code = optcode;
459 optflag = &bin_optflag;
461 optflag = &dhcp_optflags[udhcp_option_idx(opt)];
466 val = strtok(NULL, ", \t");
469 length = dhcp_option_lengths[optflag->flags & OPTION_TYPE_MASK];
471 opt = buffer; /* new meaning for variable opt */
472 switch (optflag->flags & OPTION_TYPE_MASK) {
474 retval = udhcp_str2nip(val, buffer);
477 retval = udhcp_str2nip(val, buffer);
478 val = strtok(NULL, ", \t/-");
482 retval = udhcp_str2nip(val, buffer + 4);
485 case OPTION_STRING_HOST:
486 #if ENABLE_FEATURE_UDHCP_RFC3397
487 case OPTION_DNS_STRING:
489 length = strnlen(val, 254);
495 // case OPTION_BOOLEAN: {
496 // static const char no_yes[] ALIGN1 = "no\0yes\0";
497 // buffer[0] = retval = index_in_strings(no_yes, val);
498 // retval++; /* 0 - bad; 1: "no" 2: "yes" */
502 buffer[0] = bb_strtou32(val, NULL, 0);
503 retval = (errno == 0);
505 /* htonX are macros in older libc's, using temp var
506 * in code below for safety */
507 /* TODO: use bb_strtoX? */
509 uint32_t tmp = bb_strtou32(val, NULL, 0);
510 *result_u16 = htons(tmp);
511 retval = (errno == 0 /*&& tmp < 0x10000*/);
514 // case OPTION_S16: {
515 // long tmp = bb_strtoi32(val, NULL, 0);
516 // *result_u16 = htons(tmp);
517 // retval = (errno == 0);
521 uint32_t tmp = bb_strtou32(val, NULL, 0);
522 *result_u32 = htonl(tmp);
523 retval = (errno == 0);
527 int32_t tmp = bb_strtoi32(val, NULL, 0);
528 *result_u32 = htonl(tmp);
529 retval = (errno == 0);
532 case OPTION_STATIC_ROUTES: {
533 /* Input: "a.b.c.d/m" */
534 /* Output: mask(1 byte),pfx(0-4 bytes),gw(4 bytes) */
536 char *slash = strchr(val, '/');
539 retval = udhcp_str2nip(val, buffer + 1);
540 buffer[0] = mask = bb_strtou(slash + 1, NULL, 10);
541 val = strtok(NULL, ", \t/-");
542 if (!val || mask > 32 || errno)
545 length = ((mask + 7) >> 3) + 5;
546 retval = udhcp_str2nip(val, buffer + (length - 4));
551 case OPTION_BIN: /* handled in attach_option() */
558 attach_option(opt_list, optflag, opt, length);
559 } while (retval && (optflag->flags & OPTION_LIST));
564 /* note: ip is a pointer to an IPv6 in network order, possibly misaliged */
565 int FAST_FUNC sprint_nip6(char *dest, /*const char *pre,*/ const uint8_t *ip)
567 char hexstrbuf[16 * 2];
568 bin2hex(hexstrbuf, (void*)ip, 16);
569 return sprintf(dest, /* "%s" */
570 "%.4s:%.4s:%.4s:%.4s:%.4s:%.4s:%.4s:%.4s",