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 #if ENABLE_UDHCPC || ENABLE_UDHCPD
18 /* Supported options are easily added here.
19 * See RFC2132 for more options.
20 * OPTION_REQ: these options are requested by udhcpc (unless -o).
22 const struct dhcp_optflag dhcp_optflags[] = {
24 { OPTION_IP | OPTION_REQ, 0x01 }, /* DHCP_SUBNET */
25 { OPTION_S32 , 0x02 }, /* DHCP_TIME_OFFSET */
26 { OPTION_IP | OPTION_LIST | OPTION_REQ, 0x03 }, /* DHCP_ROUTER */
27 // { OPTION_IP | OPTION_LIST , 0x04 }, /* DHCP_TIME_SERVER */
28 // { OPTION_IP | OPTION_LIST , 0x05 }, /* DHCP_NAME_SERVER */
29 { OPTION_IP | OPTION_LIST | OPTION_REQ, 0x06 }, /* DHCP_DNS_SERVER */
30 // { OPTION_IP | OPTION_LIST , 0x07 }, /* DHCP_LOG_SERVER */
31 // { OPTION_IP | OPTION_LIST , 0x08 }, /* DHCP_COOKIE_SERVER */
32 { OPTION_IP | OPTION_LIST , 0x09 }, /* DHCP_LPR_SERVER */
33 { OPTION_STRING_HOST | OPTION_REQ, 0x0c }, /* DHCP_HOST_NAME */
34 { OPTION_U16 , 0x0d }, /* DHCP_BOOT_SIZE */
35 { OPTION_STRING_HOST | OPTION_REQ, 0x0f }, /* DHCP_DOMAIN_NAME */
36 { OPTION_IP , 0x10 }, /* DHCP_SWAP_SERVER */
37 { OPTION_STRING , 0x11 }, /* DHCP_ROOT_PATH */
38 { OPTION_U8 , 0x17 }, /* DHCP_IP_TTL */
39 { OPTION_U16 , 0x1a }, /* DHCP_MTU */
40 //TODO: why do we request DHCP_BROADCAST? Can't we assume that
41 //in the unlikely case it is different from typical N.N.255.255,
42 //server would let us know anyway?
43 { OPTION_IP | OPTION_REQ, 0x1c }, /* DHCP_BROADCAST */
44 { OPTION_IP_PAIR | OPTION_LIST , 0x21 }, /* DHCP_ROUTES */
45 { OPTION_STRING_HOST , 0x28 }, /* DHCP_NIS_DOMAIN */
46 { OPTION_IP | OPTION_LIST , 0x29 }, /* DHCP_NIS_SERVER */
47 { OPTION_IP | OPTION_LIST | OPTION_REQ, 0x2a }, /* DHCP_NTP_SERVER */
48 { OPTION_IP | OPTION_LIST , 0x2c }, /* DHCP_WINS_SERVER */
49 { OPTION_U32 , 0x33 }, /* DHCP_LEASE_TIME */
50 { OPTION_IP , 0x36 }, /* DHCP_SERVER_ID */
51 { OPTION_STRING , 0x38 }, /* DHCP_ERR_MESSAGE */
52 //TODO: must be combined with 'sname' and 'file' handling:
53 { OPTION_STRING_HOST , 0x42 }, /* DHCP_TFTP_SERVER_NAME */
54 { OPTION_STRING , 0x43 }, /* DHCP_BOOT_FILE */
55 //TODO: not a string, but a set of LASCII strings:
56 // { OPTION_STRING , 0x4D }, /* DHCP_USER_CLASS */
57 #if ENABLE_FEATURE_UDHCP_RFC3397
58 { OPTION_DNS_STRING | OPTION_LIST , 0x77 }, /* DHCP_DOMAIN_SEARCH */
59 { OPTION_SIP_SERVERS , 0x78 }, /* DHCP_SIP_SERVERS */
61 { OPTION_STATIC_ROUTES | OPTION_LIST , 0x79 }, /* DHCP_STATIC_ROUTES */
62 #if ENABLE_FEATURE_UDHCP_8021Q
63 { OPTION_U16 , 0x84 }, /* DHCP_VLAN_ID */
64 { OPTION_U8 , 0x85 }, /* DHCP_VLAN_PRIORITY */
66 { OPTION_STRING , 0xd1 }, /* DHCP_PXE_CONF_FILE */
67 { OPTION_STRING , 0xd2 }, /* DHCP_PXE_PATH_PREFIX */
68 { OPTION_6RD , 0xd4 }, /* DHCP_6RD */
69 { OPTION_STATIC_ROUTES | OPTION_LIST , 0xf9 }, /* DHCP_MS_STATIC_ROUTES */
70 { OPTION_STRING , 0xfc }, /* DHCP_WPAD */
72 /* Options below have no match in dhcp_option_strings[],
73 * are not passed to dhcpc scripts, and cannot be specified
74 * with "option XXX YYY" syntax in dhcpd config file.
75 * These entries are only used internally by udhcp[cd]
76 * to correctly encode options into packets.
79 { OPTION_IP , 0x32 }, /* DHCP_REQUESTED_IP */
80 { OPTION_U8 , 0x35 }, /* DHCP_MESSAGE_TYPE */
81 { OPTION_U16 , 0x39 }, /* DHCP_MAX_SIZE */
82 //looks like these opts will work just fine even without these defs:
83 // { OPTION_STRING , 0x3c }, /* DHCP_VENDOR */
84 // /* not really a string: */
85 // { OPTION_STRING , 0x3d }, /* DHCP_CLIENT_ID */
86 { 0, 0 } /* zeroed terminating entry */
89 /* Used for converting options from incoming packets to env variables
90 * for udhcpc script, and for setting options for udhcpd via
91 * "opt OPTION_NAME OPTION_VALUE" directives in udhcpd.conf file.
93 /* Must match dhcp_optflags[] order */
94 const char dhcp_option_strings[] ALIGN1 =
95 "subnet" "\0" /* DHCP_SUBNET */
96 "timezone" "\0" /* DHCP_TIME_OFFSET */
97 "router" "\0" /* DHCP_ROUTER */
98 // "timesrv" "\0" /* DHCP_TIME_SERVER */
99 // "namesrv" "\0" /* DHCP_NAME_SERVER */
100 "dns" "\0" /* DHCP_DNS_SERVER */
101 // "logsrv" "\0" /* DHCP_LOG_SERVER */
102 // "cookiesrv" "\0" /* DHCP_COOKIE_SERVER */
103 "lprsrv" "\0" /* DHCP_LPR_SERVER */
104 "hostname" "\0" /* DHCP_HOST_NAME */
105 "bootsize" "\0" /* DHCP_BOOT_SIZE */
106 "domain" "\0" /* DHCP_DOMAIN_NAME */
107 "swapsrv" "\0" /* DHCP_SWAP_SERVER */
108 "rootpath" "\0" /* DHCP_ROOT_PATH */
109 "ipttl" "\0" /* DHCP_IP_TTL */
110 "mtu" "\0" /* DHCP_MTU */
111 "broadcast" "\0" /* DHCP_BROADCAST */
112 "routes" "\0" /* DHCP_ROUTES */
113 "nisdomain" "\0" /* DHCP_NIS_DOMAIN */
114 "nissrv" "\0" /* DHCP_NIS_SERVER */
115 "ntpsrv" "\0" /* DHCP_NTP_SERVER */
116 "wins" "\0" /* DHCP_WINS_SERVER */
117 "lease" "\0" /* DHCP_LEASE_TIME */
118 "serverid" "\0" /* DHCP_SERVER_ID */
119 "message" "\0" /* DHCP_ERR_MESSAGE */
120 "tftp" "\0" /* DHCP_TFTP_SERVER_NAME */
121 "bootfile" "\0" /* DHCP_BOOT_FILE */
122 // "userclass" "\0" /* DHCP_USER_CLASS */
123 #if ENABLE_FEATURE_UDHCP_RFC3397
124 "search" "\0" /* DHCP_DOMAIN_SEARCH */
125 // doesn't work in udhcpd.conf since OPTION_SIP_SERVERS
126 // is not handled yet by "string->option" conversion code:
127 "sipsrv" "\0" /* DHCP_SIP_SERVERS */
129 "staticroutes" "\0"/* DHCP_STATIC_ROUTES */
130 #if ENABLE_FEATURE_UDHCP_8021Q
131 "vlanid" "\0" /* DHCP_VLAN_ID */
132 "vlanpriority" "\0"/* DHCP_VLAN_PRIORITY */
134 "pxeconffile" "\0" /* DHCP_PXE_CONF_FILE */
135 "pxepathprefix" "\0" /* DHCP_PXE_PATH_PREFIX */
136 "ip6rd" "\0" /* DHCP_6RD */
137 "msstaticroutes""\0"/* DHCP_MS_STATIC_ROUTES */
138 "wpad" "\0" /* DHCP_WPAD */
142 /* Lengths of the option types in binary form.
144 * udhcp_str2optset: to determine how many bytes to allocate.
145 * xmalloc_optname_optval: to estimate string length
146 * from binary option length: (option[LEN] / dhcp_option_lengths[opt_type])
147 * is the number of elements, multiply it by one element's string width
148 * (len_of_option_as_string[opt_type]) and you know how wide string you need.
150 const uint8_t dhcp_option_lengths[] ALIGN1 = {
152 [OPTION_IP_PAIR] = 8,
153 // [OPTION_BOOLEAN] = 1,
154 [OPTION_STRING] = 1, /* ignored by udhcp_str2optset */
155 [OPTION_STRING_HOST] = 1, /* ignored by udhcp_str2optset */
156 #if ENABLE_FEATURE_UDHCP_RFC3397
157 [OPTION_DNS_STRING] = 1, /* ignored by both udhcp_str2optset and xmalloc_optname_optval */
158 [OPTION_SIP_SERVERS] = 1,
165 /* Just like OPTION_STRING, we use minimum length here */
166 [OPTION_STATIC_ROUTES] = 5,
167 [OPTION_6RD] = 12, /* ignored by udhcp_str2optset */
168 /* The above value was chosen as follows:
169 * len_of_option_as_string[] for this option is >60: it's a string of the form
170 * "32 128 ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff 255.255.255.255 ".
171 * Each additional ipv4 address takes 4 bytes in binary option and appends
172 * another "255.255.255.255 " 16-byte string. We can set [OPTION_6RD] = 4
173 * but this severely overestimates string length: instead of 16 bytes,
174 * it adds >60 for every 4 bytes in binary option.
175 * We cheat and declare here that option is in units of 12 bytes.
176 * This adds more than 60 bytes for every three ipv4 addresses - more than enough.
177 * (Even 16 instead of 12 should work, but let's be paranoid).
182 #if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 2
183 static void log_option(const char *pfx, const uint8_t *opt)
185 if (dhcp_verbose >= 2) {
186 char buf[256 * 2 + 2];
187 *bin2hex(buf, (void*) (opt + OPT_DATA), opt[OPT_LEN]) = '\0';
188 bb_error_msg("%s: 0x%02x %s", pfx, opt[OPT_CODE], buf);
192 # define log_option(pfx, opt) ((void)0)
195 unsigned FAST_FUNC udhcp_option_idx(const char *name, const char *option_strings)
197 int n = index_in_strings(option_strings, name);
209 d = buf = xzalloc(s - option_strings);
211 while (!(*s == '\0' && s[1] == '\0')) {
212 *d++ = (*s == '\0' ? ' ' : *s);
215 bb_error_msg_and_die("unknown option '%s', known options: %s", name, buf);
219 /* Get an option with bounds checking (warning, result is not aligned) */
220 uint8_t* FAST_FUNC udhcp_get_option(struct dhcp_packet *packet, int code)
227 FILE_FIELD101 = FILE_FIELD * 0x101,
228 SNAME_FIELD101 = SNAME_FIELD * 0x101,
231 /* option bytes: [code][len][data1][data2]..[dataLEN] */
232 optionptr = packet->options;
233 rem = sizeof(packet->options);
237 bb_error_msg("bad packet, malformed option field");
241 /* DHCP_PADDING and DHCP_END have no [len] byte */
242 if (optionptr[OPT_CODE] == DHCP_PADDING) {
247 if (optionptr[OPT_CODE] == DHCP_END) {
248 if ((overload & FILE_FIELD101) == FILE_FIELD) {
249 /* can use packet->file, and didn't look at it yet */
250 overload |= FILE_FIELD101; /* "we looked at it" */
251 optionptr = packet->file;
252 rem = sizeof(packet->file);
255 if ((overload & SNAME_FIELD101) == SNAME_FIELD) {
256 /* can use packet->sname, and didn't look at it yet */
257 overload |= SNAME_FIELD101; /* "we looked at it" */
258 optionptr = packet->sname;
259 rem = sizeof(packet->sname);
266 goto complain; /* complain and return NULL */
267 len = 2 + optionptr[OPT_LEN];
270 goto complain; /* complain and return NULL */
272 if (optionptr[OPT_CODE] == code) {
273 log_option("option found", optionptr);
274 return optionptr + OPT_DATA;
277 if (optionptr[OPT_CODE] == DHCP_OPTION_OVERLOAD) {
279 overload |= optionptr[OPT_DATA];
285 /* log3 because udhcpc uses it a lot - very noisy */
286 log3("option 0x%02x not found", code);
290 /* Return the position of the 'end' option (no bounds checking) */
291 int FAST_FUNC udhcp_end_option(uint8_t *optionptr)
295 while (optionptr[i] != DHCP_END) {
296 if (optionptr[i] != DHCP_PADDING)
297 i += optionptr[i + OPT_LEN] + OPT_DATA-1;
303 /* Add an option (supplied in binary form) to the options.
304 * Option format: [code][len][data1][data2]..[dataLEN]
306 void FAST_FUNC udhcp_add_binary_option(struct dhcp_packet *packet, uint8_t *addopt)
309 uint8_t *optionptr = packet->options;
310 unsigned end = udhcp_end_option(optionptr);
312 len = OPT_DATA + addopt[OPT_LEN];
313 /* end position + (option code/length + addopt length) + end option */
314 if (end + len + 1 >= DHCP_OPTIONS_BUFSIZE) {
315 //TODO: learn how to use overflow option if we exhaust packet->options[]
316 bb_error_msg("option 0x%02x did not fit into the packet",
320 log_option("adding option", addopt);
321 memcpy(optionptr + end, addopt, len);
322 optionptr[end + len] = DHCP_END;
325 #if ENABLE_UDHCPC || ENABLE_UDHCPD
326 /* Add an one to four byte option to a packet */
327 void FAST_FUNC udhcp_add_simple_option(struct dhcp_packet *packet, uint8_t code, uint32_t data)
329 const struct dhcp_optflag *dh;
331 for (dh = dhcp_optflags; dh->code; dh++) {
332 if (dh->code == code) {
333 uint8_t option[6], len;
335 option[OPT_CODE] = code;
336 len = dhcp_option_lengths[dh->flags & OPTION_TYPE_MASK];
337 option[OPT_LEN] = len;
339 data <<= 8 * (4 - len);
340 /* Assignment is unaligned! */
341 move_to_unaligned32(&option[OPT_DATA], data);
342 udhcp_add_binary_option(packet, option);
347 bb_error_msg("can't add option 0x%02x", code);
351 /* Find option 'code' in opt_list */
352 struct option_set* FAST_FUNC udhcp_find_option(struct option_set *opt_list, uint8_t code)
354 while (opt_list && opt_list->data[OPT_CODE] < code)
355 opt_list = opt_list->next;
357 if (opt_list && opt_list->data[OPT_CODE] == code)
362 /* Parse string to IP in network order */
363 int FAST_FUNC udhcp_str2nip(const char *str, void *arg)
365 len_and_sockaddr *lsa;
367 lsa = host_and_af2sockaddr(str, 0, AF_INET);
370 /* arg maybe unaligned */
371 move_to_unaligned32((uint32_t*)arg, lsa->u.sin.sin_addr.s_addr);
377 * Parse string option representation to binary form and add it to opt_list.
378 * Called to parse "udhcpc -x OPTNAME:OPTVAL"
379 * and to parse udhcpd.conf's "opt OPTNAME OPTVAL" directives.
381 /* helper for the helper */
382 static char *allocate_tempopt_if_needed(
383 const struct dhcp_optflag *optflag,
387 char *allocated = NULL;
388 if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_BIN) {
390 allocated = xstrdup(buffer); /* more than enough */
391 end = hex2bin(allocated, buffer, 255);
393 bb_error_msg_and_die("malformed hex string '%s'", buffer);
394 *length_p = end - allocated;
398 /* helper: add an option to the opt_list */
399 static NOINLINE void attach_option(
400 struct option_set **opt_list,
401 const struct dhcp_optflag *optflag,
405 struct option_set *existing;
408 allocated = allocate_tempopt_if_needed(optflag, buffer, &length);
409 #if ENABLE_FEATURE_UDHCP_RFC3397
410 if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_DNS_STRING) {
411 /* reuse buffer and length for RFC1035-formatted string */
412 allocated = buffer = (char *)dname_enc(NULL, 0, buffer, &length);
416 existing = udhcp_find_option(*opt_list, optflag->code);
418 struct option_set *new, **curr;
420 /* make a new option */
421 log2("attaching option %02x to list", optflag->code);
422 new = xmalloc(sizeof(*new));
423 new->data = xmalloc(length + OPT_DATA);
424 new->data[OPT_CODE] = optflag->code;
425 new->data[OPT_LEN] = length;
426 memcpy(new->data + OPT_DATA, (allocated ? allocated : buffer), length);
429 while (*curr && (*curr)->data[OPT_CODE] < optflag->code)
430 curr = &(*curr)->next;
437 if (optflag->flags & OPTION_LIST) {
440 /* add it to an existing option */
441 log2("attaching option %02x to existing member of list", optflag->code);
442 old_len = existing->data[OPT_LEN];
443 if (old_len + length < 255) {
444 /* actually 255 is ok too, but adding a space can overlow it */
446 existing->data = xrealloc(existing->data, OPT_DATA + 1 + old_len + length);
447 if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_STRING
448 || (optflag->flags & OPTION_TYPE_MASK) == OPTION_STRING_HOST
450 /* add space separator between STRING options in a list */
451 existing->data[OPT_DATA + old_len] = ' ';
454 memcpy(existing->data + OPT_DATA + old_len, (allocated ? allocated : buffer), length);
455 existing->data[OPT_LEN] = old_len + length;
456 } /* else, ignore the data, we could put this in a second option in the future */
457 } /* else, ignore the new data */
463 int FAST_FUNC udhcp_str2optset(const char *const_str, void *arg, const struct dhcp_optflag *optflags, const char *option_strings)
465 struct option_set **opt_list = arg;
468 const struct dhcp_optflag *optflag;
469 struct dhcp_optflag bin_optflag;
472 /* IP_PAIR needs 8 bytes, STATIC_ROUTES needs 9 max */
473 char buffer[9] ALIGNED(4);
474 uint16_t *result_u16 = (uint16_t *) buffer;
475 uint32_t *result_u32 = (uint32_t *) buffer;
477 /* Cheat, the only *const* str possible is "" */
478 str = (char *) const_str;
479 opt = strtok(str, " \t=");
483 optcode = bb_strtou(opt, NULL, 0);
484 if (!errno && optcode < 255) {
485 /* Raw (numeric) option code */
486 bin_optflag.flags = OPTION_BIN;
487 bin_optflag.code = optcode;
488 optflag = &bin_optflag;
490 optflag = &optflags[udhcp_option_idx(opt, option_strings)];
495 val = strtok(NULL, ", \t");
498 length = dhcp_option_lengths[optflag->flags & OPTION_TYPE_MASK];
500 opt = buffer; /* new meaning for variable opt */
501 switch (optflag->flags & OPTION_TYPE_MASK) {
503 retval = udhcp_str2nip(val, buffer);
506 retval = udhcp_str2nip(val, buffer);
507 val = strtok(NULL, ", \t/-");
511 retval = udhcp_str2nip(val, buffer + 4);
514 case OPTION_STRING_HOST:
515 #if ENABLE_FEATURE_UDHCP_RFC3397
516 case OPTION_DNS_STRING:
518 length = strnlen(val, 254);
524 // case OPTION_BOOLEAN: {
525 // static const char no_yes[] ALIGN1 = "no\0yes\0";
526 // buffer[0] = retval = index_in_strings(no_yes, val);
527 // retval++; /* 0 - bad; 1: "no" 2: "yes" */
531 buffer[0] = bb_strtou32(val, NULL, 0);
532 retval = (errno == 0);
534 /* htonX are macros in older libc's, using temp var
535 * in code below for safety */
536 /* TODO: use bb_strtoX? */
538 uint32_t tmp = bb_strtou32(val, NULL, 0);
539 *result_u16 = htons(tmp);
540 retval = (errno == 0 /*&& tmp < 0x10000*/);
543 // case OPTION_S16: {
544 // long tmp = bb_strtoi32(val, NULL, 0);
545 // *result_u16 = htons(tmp);
546 // retval = (errno == 0);
550 uint32_t tmp = bb_strtou32(val, NULL, 0);
551 *result_u32 = htonl(tmp);
552 retval = (errno == 0);
556 int32_t tmp = bb_strtoi32(val, NULL, 0);
557 *result_u32 = htonl(tmp);
558 retval = (errno == 0);
561 case OPTION_STATIC_ROUTES: {
562 /* Input: "a.b.c.d/m" */
563 /* Output: mask(1 byte),pfx(0-4 bytes),gw(4 bytes) */
565 char *slash = strchr(val, '/');
568 retval = udhcp_str2nip(val, buffer + 1);
569 buffer[0] = mask = bb_strtou(slash + 1, NULL, 10);
570 val = strtok(NULL, ", \t/-");
571 if (!val || mask > 32 || errno)
574 length = ((mask + 7) >> 3) + 5;
575 retval = udhcp_str2nip(val, buffer + (length - 4));
580 case OPTION_BIN: /* handled in attach_option() */
587 attach_option(opt_list, optflag, opt, length);
588 } while (retval && (optflag->flags & OPTION_LIST));
593 /* note: ip is a pointer to an IPv6 in network order, possibly misaliged */
594 int FAST_FUNC sprint_nip6(char *dest, /*const char *pre,*/ const uint8_t *ip)
596 char hexstrbuf[16 * 2];
597 bin2hex(hexstrbuf, (void*)ip, 16);
598 return sprintf(dest, /* "%s" */
599 "%.4s:%.4s:%.4s:%.4s:%.4s:%.4s:%.4s:%.4s",