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"Robert P. J. Day"63fc1a92006-07-02 19:47:05 +00001/* vi: set sw=4 ts=4: */
Denys Vlasenko6b24d532010-03-22 13:42:13 +01002/*
Denys Vlasenko385b4562010-03-26 10:09:34 +01003 * udhcp client
Mike Frysinger7031f622006-05-08 03:20:50 +00004 *
5 * Russ Dill <Russ.Dill@asu.edu> July 2001
6 *
Denys Vlasenko6b24d532010-03-22 13:42:13 +01007 * 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.
Mike Frysinger7031f622006-05-08 03:20:50 +000020 */
Denis Vlasenkoaf1c8432007-03-26 13:22:35 +000021#include <syslog.h>
Denis Vlasenko1caca342007-08-02 10:14:29 +000022/* Override ENABLE_FEATURE_PIDFILE - ifupdown needs our pidfile to always exist */
23#define WANT_PIDFILE 1
Mike Frysinger7031f622006-05-08 03:20:50 +000024#include "common.h"
25#include "dhcpd.h"
26#include "dhcpc.h"
Denis Vlasenko5a3395b2006-11-18 19:51:32 +000027
Dan Fandrichf533ec82011-06-10 05:17:59 +020028#include <netinet/if_ether.h>
29#include <netpacket/packet.h>
Denys Vlasenko6b24d532010-03-22 13:42:13 +010030#include <linux/filter.h>
31
Denis Vlasenkodeabacd2007-09-30 17:55:43 +000032/* struct client_config_t client_config is in bb_common_bufsiz1 */
Denis Vlasenkoe2d3ded2006-11-27 23:43:28 +000033
Mike Frysinger7031f622006-05-08 03:20:50 +000034
Keith Younge6bb8d32011-03-07 03:18:46 +010035#if ENABLE_LONG_OPTS
36static const char udhcpc_longopts[] ALIGN1 =
37 "clientid-none\0" No_argument "C"
38 "vendorclass\0" Required_argument "V"
39 "hostname\0" Required_argument "H"
40 "fqdn\0" Required_argument "F"
41 "interface\0" Required_argument "i"
42 "now\0" No_argument "n"
43 "pidfile\0" Required_argument "p"
44 "quit\0" No_argument "q"
45 "release\0" No_argument "R"
46 "request\0" Required_argument "r"
47 "script\0" Required_argument "s"
48 "timeout\0" Required_argument "T"
49 "version\0" No_argument "v"
50 "retries\0" Required_argument "t"
51 "tryagain\0" Required_argument "A"
52 "syslog\0" No_argument "S"
53 "request-option\0" Required_argument "O"
54 "no-default-options\0" No_argument "o"
55 "foreground\0" No_argument "f"
56 "background\0" No_argument "b"
57 "broadcast\0" No_argument "B"
58 IF_FEATURE_UDHCPC_ARPING("arping\0" No_argument "a")
59 IF_FEATURE_UDHCP_PORT("client-port\0" Required_argument "P")
60 ;
61#endif
62/* Must match getopt32 option string order */
63enum {
64 OPT_C = 1 << 0,
65 OPT_V = 1 << 1,
66 OPT_H = 1 << 2,
67 OPT_h = 1 << 3,
68 OPT_F = 1 << 4,
69 OPT_i = 1 << 5,
70 OPT_n = 1 << 6,
71 OPT_p = 1 << 7,
72 OPT_q = 1 << 8,
73 OPT_R = 1 << 9,
74 OPT_r = 1 << 10,
75 OPT_s = 1 << 11,
76 OPT_T = 1 << 12,
77 OPT_t = 1 << 13,
78 OPT_S = 1 << 14,
79 OPT_A = 1 << 15,
80 OPT_O = 1 << 16,
81 OPT_o = 1 << 17,
82 OPT_x = 1 << 18,
83 OPT_f = 1 << 19,
84 OPT_B = 1 << 20,
85/* The rest has variable bit positions, need to be clever */
86 OPTBIT_B = 20,
87 USE_FOR_MMU( OPTBIT_b,)
88 IF_FEATURE_UDHCPC_ARPING(OPTBIT_a,)
89 IF_FEATURE_UDHCP_PORT( OPTBIT_P,)
90 USE_FOR_MMU( OPT_b = 1 << OPTBIT_b,)
91 IF_FEATURE_UDHCPC_ARPING(OPT_a = 1 << OPTBIT_a,)
92 IF_FEATURE_UDHCP_PORT( OPT_P = 1 << OPTBIT_P,)
93};
94
95
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +010096/*** Script execution code ***/
97
98/* get a rough idea of how long an option will be (rounding up...) */
99static const uint8_t len_of_option_as_string[] = {
Denys Vlasenko243ddcb2010-04-03 17:34:52 +0200100 [OPTION_IP ] = sizeof("255.255.255.255 "),
101 [OPTION_IP_PAIR ] = sizeof("255.255.255.255 ") * 2,
102 [OPTION_STATIC_ROUTES ] = sizeof("255.255.255.255/32 255.255.255.255 "),
Denys Vlasenko1f56e512011-10-19 22:40:35 +0200103 [OPTION_6RD ] = sizeof("32 128 ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff 255.255.255.255 "),
Denys Vlasenko243ddcb2010-04-03 17:34:52 +0200104 [OPTION_STRING ] = 1,
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100105#if ENABLE_FEATURE_UDHCP_RFC3397
Denys Vlasenko243ddcb2010-04-03 17:34:52 +0200106 [OPTION_DNS_STRING ] = 1, /* unused */
107 /* Hmmm, this severely overestimates size if SIP_SERVERS option
108 * is in domain name form: N-byte option in binary form
109 * mallocs ~16*N bytes. But it is freed almost at once.
110 */
111 [OPTION_SIP_SERVERS ] = sizeof("255.255.255.255 "),
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100112#endif
Denys Vlasenko243ddcb2010-04-03 17:34:52 +0200113// [OPTION_BOOLEAN ] = sizeof("yes "),
114 [OPTION_U8 ] = sizeof("255 "),
115 [OPTION_U16 ] = sizeof("65535 "),
116// [OPTION_S16 ] = sizeof("-32768 "),
117 [OPTION_U32 ] = sizeof("4294967295 "),
118 [OPTION_S32 ] = sizeof("-2147483684 "),
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100119};
120
121/* note: ip is a pointer to an IP in network order, possibly misaliged */
122static int sprint_nip(char *dest, const char *pre, const uint8_t *ip)
123{
124 return sprintf(dest, "%s%u.%u.%u.%u", pre, ip[0], ip[1], ip[2], ip[3]);
125}
126
Denys Vlasenko42816c22011-10-20 10:52:07 +0200127static int sprint_nip6(char *dest, /*const char *pre,*/ const uint8_t *ip)
Denys Vlasenko1f56e512011-10-19 22:40:35 +0200128{
129 char hexstrbuf[16 * 2];
130 bin2hex(hexstrbuf, (void*)ip, 16);
Denys Vlasenko42816c22011-10-20 10:52:07 +0200131 return sprintf(dest, /* "%s" */
Denys Vlasenko1f56e512011-10-19 22:40:35 +0200132 "%.4s:%.4s:%.4s:%.4s:%.4s:%.4s:%.4s:%.4s",
Denys Vlasenko42816c22011-10-20 10:52:07 +0200133 /* pre, */
Denys Vlasenko1f56e512011-10-19 22:40:35 +0200134 hexstrbuf + 0 * 4,
135 hexstrbuf + 1 * 4,
136 hexstrbuf + 2 * 4,
137 hexstrbuf + 3 * 4,
138 hexstrbuf + 4 * 4,
139 hexstrbuf + 5 * 4,
140 hexstrbuf + 6 * 4,
141 hexstrbuf + 7 * 4
142 );
143}
144
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100145/* really simple implementation, just count the bits */
146static int mton(uint32_t mask)
147{
148 int i = 0;
149 mask = ntohl(mask); /* 111110000-like bit pattern */
150 while (mask) {
151 i++;
152 mask <<= 1;
153 }
154 return i;
155}
156
157/* Create "opt_name=opt_value" string */
Denys Vlasenkoc03602b2010-04-04 15:28:49 +0200158static NOINLINE char *xmalloc_optname_optval(uint8_t *option, const struct dhcp_optflag *optflag, const char *opt_name)
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100159{
160 unsigned upper_length;
161 int len, type, optlen;
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100162 char *dest, *ret;
163
Denys Vlasenko1dff6722011-10-20 12:29:18 +0200164 /* option points to OPT_DATA, need to go back to get OPT_LEN */
165 len = option[-OPT_DATA + OPT_LEN];
Vladislav Grishenkoad8def22010-10-17 12:27:50 +0200166
Denys Vlasenkoc03602b2010-04-04 15:28:49 +0200167 type = optflag->flags & OPTION_TYPE_MASK;
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100168 optlen = dhcp_option_lengths[type];
Denys Vlasenko1f56e512011-10-19 22:40:35 +0200169 upper_length = len_of_option_as_string[type]
170 * ((unsigned)(len + optlen - 1) / (unsigned)optlen);
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100171
172 dest = ret = xmalloc(upper_length + strlen(opt_name) + 2);
173 dest += sprintf(ret, "%s=", opt_name);
174
175 while (len >= optlen) {
176 switch (type) {
Denys Vlasenkocd4d78f2011-10-20 13:21:55 +0200177 case OPTION_IP:
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100178 case OPTION_IP_PAIR:
179 dest += sprint_nip(dest, "", option);
Denys Vlasenkocd4d78f2011-10-20 13:21:55 +0200180 if (type == OPTION_IP)
181 break;
182 dest += sprint_nip(dest, "/", option + 4);
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100183 break;
Denys Vlasenkoa8f6b992010-03-26 08:35:24 +0100184// case OPTION_BOOLEAN:
185// dest += sprintf(dest, *option ? "yes" : "no");
186// break;
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100187 case OPTION_U8:
188 dest += sprintf(dest, "%u", *option);
189 break;
Denys Vlasenko243ddcb2010-04-03 17:34:52 +0200190// case OPTION_S16:
191 case OPTION_U16: {
192 uint16_t val_u16;
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100193 move_from_unaligned16(val_u16, option);
194 dest += sprintf(dest, "%u", ntohs(val_u16));
195 break;
Denys Vlasenko243ddcb2010-04-03 17:34:52 +0200196 }
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100197 case OPTION_S32:
Denys Vlasenko243ddcb2010-04-03 17:34:52 +0200198 case OPTION_U32: {
199 uint32_t val_u32;
200 move_from_unaligned32(val_u32, option);
201 dest += sprintf(dest, type == OPTION_U32 ? "%lu" : "%ld", (unsigned long) ntohl(val_u32));
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100202 break;
Denys Vlasenko243ddcb2010-04-03 17:34:52 +0200203 }
Denys Vlasenkocd4d78f2011-10-20 13:21:55 +0200204 /* Note: options which use 'return' instead of 'break'
205 * (for example, OPTION_STRING) skip the code which handles
206 * the case of list of options.
207 */
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100208 case OPTION_STRING:
209 memcpy(dest, option, len);
210 dest[len] = '\0';
Denys Vlasenkocd4d78f2011-10-20 13:21:55 +0200211 return ret;
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100212 case OPTION_STATIC_ROUTES: {
213 /* Option binary format:
214 * mask [one byte, 0..32]
215 * ip [big endian, 0..4 bytes depending on mask]
216 * router [big endian, 4 bytes]
217 * may be repeated
218 *
219 * We convert it to a string "IP/MASK ROUTER IP2/MASK2 ROUTER2"
220 */
221 const char *pfx = "";
222
223 while (len >= 1 + 4) { /* mask + 0-byte ip + router */
224 uint32_t nip;
225 uint8_t *p;
226 unsigned mask;
227 int bytes;
228
229 mask = *option++;
230 if (mask > 32)
231 break;
232 len--;
233
234 nip = 0;
235 p = (void*) &nip;
236 bytes = (mask + 7) / 8; /* 0 -> 0, 1..8 -> 1, 9..16 -> 2 etc */
237 while (--bytes >= 0) {
238 *p++ = *option++;
239 len--;
240 }
241 if (len < 4)
242 break;
243
244 /* print ip/mask */
245 dest += sprint_nip(dest, pfx, (void*) &nip);
246 pfx = " ";
247 dest += sprintf(dest, "/%u ", mask);
248 /* print router */
249 dest += sprint_nip(dest, "", option);
250 option += 4;
251 len -= 4;
252 }
253
254 return ret;
255 }
Denys Vlasenko1dff6722011-10-20 12:29:18 +0200256 case OPTION_6RD:
Denys Vlasenko1f56e512011-10-19 22:40:35 +0200257 /* Option binary format (see RFC 5969):
Denys Vlasenko1dff6722011-10-20 12:29:18 +0200258 * 0 1 2 3
259 * 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
Denys Vlasenko1f56e512011-10-19 22:40:35 +0200260 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
261 * | OPTION_6RD | option-length | IPv4MaskLen | 6rdPrefixLen |
262 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Denys Vlasenko1f56e512011-10-19 22:40:35 +0200263 * | 6rdPrefix |
Denys Vlasenko1dff6722011-10-20 12:29:18 +0200264 * ... (16 octets) ...
Denys Vlasenko1f56e512011-10-19 22:40:35 +0200265 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Denys Vlasenko1dff6722011-10-20 12:29:18 +0200266 * ... 6rdBRIPv4Address(es) ...
Denys Vlasenko1f56e512011-10-19 22:40:35 +0200267 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Denys Vlasenko1f56e512011-10-19 22:40:35 +0200268 * We convert it to a string
269 * "IPv4MaskLen 6rdPrefixLen 6rdPrefix 6rdBRIPv4Address..."
Denys Vlasenko1dff6722011-10-20 12:29:18 +0200270 *
271 * Sanity check: ensure that our length is at least 22 bytes, that
Denys Vlasenko1f56e512011-10-19 22:40:35 +0200272 * IPv4MaskLen <= 32,
273 * 6rdPrefixLen <= 128,
274 * 6rdPrefixLen + (32 - IPv4MaskLen) <= 128
275 * (2nd condition need no check - it follows from 1st and 3rd).
Denys Vlasenko1dff6722011-10-20 12:29:18 +0200276 * Else, return envvar with empty value ("optname=")
Denys Vlasenko1f56e512011-10-19 22:40:35 +0200277 */
Denys Vlasenko1dff6722011-10-20 12:29:18 +0200278 if (len >= (1 + 1 + 16 + 4)
Denys Vlasenko1f56e512011-10-19 22:40:35 +0200279 && option[0] <= 32
280 && (option[1] + 32 - option[0]) <= 128
281 ) {
282 /* IPv4MaskLen */
283 dest += sprintf(dest, "%u ", *option++);
284 /* 6rdPrefixLen */
285 dest += sprintf(dest, "%u ", *option++);
286 /* 6rdPrefix */
Denys Vlasenko42816c22011-10-20 10:52:07 +0200287 dest += sprint_nip6(dest, /* "", */ option);
Denys Vlasenko1f56e512011-10-19 22:40:35 +0200288 option += 16;
Denys Vlasenko1dff6722011-10-20 12:29:18 +0200289 len -= 1 + 1 + 16 + 4;
290 /* "+ 4" above corresponds to the length of IPv4 addr
291 * we consume in the loop below */
Denys Vlasenko1f56e512011-10-19 22:40:35 +0200292 while (1) {
Denys Vlasenko1dff6722011-10-20 12:29:18 +0200293 /* 6rdBRIPv4Address(es) */
Denys Vlasenko1f56e512011-10-19 22:40:35 +0200294 dest += sprint_nip(dest, " ", option);
295 option += 4;
Denys Vlasenko1dff6722011-10-20 12:29:18 +0200296 len -= 4; /* do we have yet another 4+ bytes? */
Denys Vlasenko1f56e512011-10-19 22:40:35 +0200297 if (len < 0)
Denys Vlasenko1dff6722011-10-20 12:29:18 +0200298 break; /* no */
Denys Vlasenko1f56e512011-10-19 22:40:35 +0200299 }
300 }
301
302 return ret;
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100303#if ENABLE_FEATURE_UDHCP_RFC3397
Denys Vlasenko243ddcb2010-04-03 17:34:52 +0200304 case OPTION_DNS_STRING:
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100305 /* unpack option into dest; use ret for prefix (i.e., "optname=") */
306 dest = dname_dec(option, len, ret);
307 if (dest) {
308 free(ret);
309 return dest;
310 }
311 /* error. return "optname=" string */
312 return ret;
Denys Vlasenko243ddcb2010-04-03 17:34:52 +0200313 case OPTION_SIP_SERVERS:
314 /* Option binary format:
315 * type: byte
316 * type=0: domain names, dns-compressed
317 * type=1: IP addrs
318 */
319 option++;
320 len--;
321 if (option[-1] == 0) {
322 dest = dname_dec(option, len, ret);
323 if (dest) {
324 free(ret);
325 return dest;
326 }
327 } else
328 if (option[-1] == 1) {
329 const char *pfx = "";
330 while (1) {
331 len -= 4;
332 if (len < 0)
333 break;
334 dest += sprint_nip(dest, pfx, option);
335 pfx = " ";
336 option += 4;
337 }
338 }
339 return ret;
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100340#endif
Denys Vlasenko243ddcb2010-04-03 17:34:52 +0200341 } /* switch */
Denys Vlasenko1dff6722011-10-20 12:29:18 +0200342
343 /* If we are here, try to format any remaining data
344 * in the option as another, similarly-formatted option
345 */
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100346 option += optlen;
347 len -= optlen;
Vladislav Grishenkoad8def22010-10-17 12:27:50 +0200348// TODO: it can be a list only if (optflag->flags & OPTION_LIST).
349// Should we bail out/warn if we see multi-ip option which is
350// not allowed to be such (for example, DHCP_BROADCAST)? -
Denys Vlasenkocd4d78f2011-10-20 13:21:55 +0200351 if (len < optlen /* || !(optflag->flags & OPTION_LIST) */)
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100352 break;
353 *dest++ = ' ';
354 *dest = '\0';
Denys Vlasenko1dff6722011-10-20 12:29:18 +0200355 } /* while */
356
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100357 return ret;
358}
359
360/* put all the parameters into the environment */
361static char **fill_envp(struct dhcp_packet *packet)
362{
Denys Vlasenkob7d19cc2010-05-30 23:41:23 +0200363 int envc;
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100364 int i;
365 char **envp, **curr;
366 const char *opt_name;
367 uint8_t *temp;
Denys Vlasenkob7d19cc2010-05-30 23:41:23 +0200368 uint8_t overload = 0;
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100369
Nigel Hathawayc37d4c62011-04-26 02:38:29 +0200370#define BITMAP unsigned
371#define BBITS (sizeof(BITMAP) * 8)
372#define BMASK(i) (1 << (i & (sizeof(BITMAP) * 8 - 1)))
373#define FOUND_OPTS(i) (found_opts[(unsigned)i / BBITS])
374 BITMAP found_opts[256 / BBITS];
375
376 memset(found_opts, 0, sizeof(found_opts));
377
Denys Vlasenkob7d19cc2010-05-30 23:41:23 +0200378 /* We need 6 elements for:
379 * "interface=IFACE"
380 * "ip=N.N.N.N" from packet->yiaddr
381 * "siaddr=IP" from packet->siaddr_nip (unless 0)
382 * "boot_file=FILE" from packet->file (unless overloaded)
383 * "sname=SERVER_HOSTNAME" from packet->sname (unless overloaded)
384 * terminating NULL
385 */
386 envc = 6;
387 /* +1 element for each option, +2 for subnet option: */
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100388 if (packet) {
Nigel Hathawayc37d4c62011-04-26 02:38:29 +0200389 /* note: do not search for "pad" (0) and "end" (255) options */
390 for (i = 1; i < 255; i++) {
391 temp = udhcp_get_option(packet, i);
392 if (temp) {
393 if (i == DHCP_OPTION_OVERLOAD)
394 overload = *temp;
395 else if (i == DHCP_SUBNET)
Denys Vlasenkofbca0c62011-10-20 14:24:18 +0200396 envc++; /* for $mask */
Denys Vlasenkob7d19cc2010-05-30 23:41:23 +0200397 envc++;
Nigel Hathawayc37d4c62011-04-26 02:38:29 +0200398 /*if (i != DHCP_MESSAGE_TYPE)*/
399 FOUND_OPTS(i) |= BMASK(i);
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100400 }
401 }
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100402 }
Nigel Hathawayc37d4c62011-04-26 02:38:29 +0200403 curr = envp = xzalloc(sizeof(envp[0]) * envc);
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100404
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100405 *curr = xasprintf("interface=%s", client_config.interface);
406 putenv(*curr++);
407
Denys Vlasenkob7d19cc2010-05-30 23:41:23 +0200408 if (!packet)
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100409 return envp;
410
Denys Vlasenkofbca0c62011-10-20 14:24:18 +0200411 /* Export BOOTP fields. Fields we don't (yet?) export:
412 * uint8_t op; // always BOOTREPLY
413 * uint8_t htype; // hardware address type. 1 = 10mb ethernet
414 * uint8_t hlen; // hardware address length
415 * uint8_t hops; // used by relay agents only
416 * uint32_t xid;
417 * uint16_t secs; // elapsed since client began acquisition/renewal
418 * uint16_t flags; // only one flag so far: bcast. Never set by server
419 * uint32_t ciaddr; // client IP (usually == yiaddr. can it be different
420 * // if during renew server wants to give us differn IP?)
421 * uint32_t gateway_nip; // relay agent IP address
422 * uint8_t chaddr[16]; // link-layer client hardware address (MAC)
423 * TODO: export gateway_nip as $giaddr?
424 */
425 /* Most important one: yiaddr as $ip */
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100426 *curr = xmalloc(sizeof("ip=255.255.255.255"));
427 sprint_nip(*curr, "ip=", (uint8_t *) &packet->yiaddr);
428 putenv(*curr++);
Denys Vlasenkofbca0c62011-10-20 14:24:18 +0200429 if (packet->siaddr_nip) {
430 /* IP address of next server to use in bootstrap */
431 *curr = xmalloc(sizeof("siaddr=255.255.255.255"));
432 sprint_nip(*curr, "siaddr=", (uint8_t *) &packet->siaddr_nip);
433 putenv(*curr++);
434 }
435 if (!(overload & FILE_FIELD) && packet->file[0]) {
436 /* watch out for invalid packets */
437 *curr = xasprintf("boot_file=%."DHCP_PKT_FILE_LEN_STR"s", packet->file);
438 putenv(*curr++);
439 }
440 if (!(overload & SNAME_FIELD) && packet->sname[0]) {
441 /* watch out for invalid packets */
442 *curr = xasprintf("sname=%."DHCP_PKT_SNAME_LEN_STR"s", packet->sname);
443 putenv(*curr++);
444 }
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100445
Denys Vlasenkofbca0c62011-10-20 14:24:18 +0200446 /* Export known DHCP options */
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100447 opt_name = dhcp_option_strings;
448 i = 0;
449 while (*opt_name) {
Nigel Hathawayc37d4c62011-04-26 02:38:29 +0200450 uint8_t code = dhcp_optflags[i].code;
451 BITMAP *found_ptr = &FOUND_OPTS(code);
452 BITMAP found_mask = BMASK(code);
453 if (!(*found_ptr & found_mask))
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100454 goto next;
Nigel Hathawayc37d4c62011-04-26 02:38:29 +0200455 *found_ptr &= ~found_mask; /* leave only unknown options */
456 temp = udhcp_get_option(packet, code);
Denys Vlasenkoc03602b2010-04-04 15:28:49 +0200457 *curr = xmalloc_optname_optval(temp, &dhcp_optflags[i], opt_name);
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100458 putenv(*curr++);
Nigel Hathawayc37d4c62011-04-26 02:38:29 +0200459 if (code == DHCP_SUBNET) {
Denys Vlasenkob7d19cc2010-05-30 23:41:23 +0200460 /* Subnet option: make things like "$ip/$mask" possible */
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100461 uint32_t subnet;
462 move_from_unaligned32(subnet, temp);
Denys Vlasenkofbca0c62011-10-20 14:24:18 +0200463 *curr = xasprintf("mask=%u", mton(subnet));
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100464 putenv(*curr++);
465 }
466 next:
467 opt_name += strlen(opt_name) + 1;
468 i++;
469 }
Denys Vlasenkofbca0c62011-10-20 14:24:18 +0200470 /* Export unknown options */
Nigel Hathawayc37d4c62011-04-26 02:38:29 +0200471 for (i = 0; i < 256;) {
472 BITMAP bitmap = FOUND_OPTS(i);
473 if (!bitmap) {
474 i += BBITS;
475 continue;
476 }
477 if (bitmap & BMASK(i)) {
478 unsigned len, ofs;
479
480 temp = udhcp_get_option(packet, i);
481 /* udhcp_get_option returns ptr to data portion,
482 * need to go back to get len
483 */
484 len = temp[-OPT_DATA + OPT_LEN];
485 *curr = xmalloc(sizeof("optNNN=") + 1 + len*2);
486 ofs = sprintf(*curr, "opt%u=", i);
Denys Vlasenko1f56e512011-10-19 22:40:35 +0200487 *bin2hex(*curr + ofs, (void*) temp, len) = '\0';
Nigel Hathawayc37d4c62011-04-26 02:38:29 +0200488 putenv(*curr++);
489 }
490 i++;
491 }
Denys Vlasenkofbca0c62011-10-20 14:24:18 +0200492
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100493 return envp;
494}
495
496/* Call a script with a par file and env vars */
497static void udhcp_run_script(struct dhcp_packet *packet, const char *name)
498{
499 char **envp, **curr;
500 char *argv[3];
501
502 if (client_config.script == NULL)
503 return;
504
505 envp = fill_envp(packet);
506
507 /* call script */
508 log1("Executing %s %s", client_config.script, name);
509 argv[0] = (char*) client_config.script;
510 argv[1] = (char*) name;
511 argv[2] = NULL;
512 spawn_and_wait(argv);
513
514 for (curr = envp; *curr; curr++) {
515 log2(" %s", *curr);
Denys Vlasenkodd8adde2010-06-24 05:00:50 +0200516 bb_unsetenv_and_free(*curr);
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100517 }
518 free(envp);
519}
520
521
522/*** Sending/receiving packets ***/
523
Denys Vlasenko8d114452010-03-22 13:44:09 +0100524static ALWAYS_INLINE uint32_t random_xid(void)
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100525{
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100526 return rand();
527}
528
529/* Initialize the packet with the proper defaults */
530static void init_packet(struct dhcp_packet *packet, char type)
531{
Denys Vlasenko9ac55962011-03-12 05:37:54 +0100532 uint16_t secs;
533
Denys Vlasenkob3af65b2010-10-20 21:37:23 +0200534 /* Fill in: op, htype, hlen, cookie fields; message type option: */
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100535 udhcp_init_header(packet, type);
Denys Vlasenkob3af65b2010-10-20 21:37:23 +0200536
537 packet->xid = random_xid();
538
Denys Vlasenko9ac55962011-03-12 05:37:54 +0100539 client_config.last_secs = monotonic_sec();
540 if (client_config.first_secs == 0)
541 client_config.first_secs = client_config.last_secs;
542 secs = client_config.last_secs - client_config.first_secs;
543 packet->secs = htons(secs);
544
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100545 memcpy(packet->chaddr, client_config.client_mac, 6);
546 if (client_config.clientid)
Denys Vlasenko7724c762010-03-26 09:32:09 +0100547 udhcp_add_binary_option(packet, client_config.clientid);
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100548}
549
Denys Vlasenko7e6add12010-03-25 20:32:38 +0100550static void add_client_options(struct dhcp_packet *packet)
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100551{
Denys Vlasenkob3af65b2010-10-20 21:37:23 +0200552 uint8_t c;
553 int i, end, len;
554
555 udhcp_add_simple_option(packet, DHCP_MAX_SIZE, htons(IP_UDP_DHCP_SIZE));
Denys Vlasenkob3af65b2010-10-20 21:37:23 +0200556
Denys Vlasenko7724c762010-03-26 09:32:09 +0100557 /* Add a "param req" option with the list of options we'd like to have
Denys Vlasenkoa8f6b992010-03-26 08:35:24 +0100558 * from stubborn DHCP servers. Pull the data from the struct in common.c.
Denys Vlasenko7e6add12010-03-25 20:32:38 +0100559 * No bounds checking because it goes towards the head of the packet. */
Denys Vlasenkob3af65b2010-10-20 21:37:23 +0200560 end = udhcp_end_option(packet->options);
561 len = 0;
Denys Vlasenkoc03602b2010-04-04 15:28:49 +0200562 for (i = 0; (c = dhcp_optflags[i].code) != 0; i++) {
563 if (( (dhcp_optflags[i].flags & OPTION_REQ)
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100564 && !client_config.no_default_options
565 )
566 || (client_config.opt_mask[c >> 3] & (1 << (c & 7)))
567 ) {
568 packet->options[end + OPT_DATA + len] = c;
569 len++;
570 }
571 }
572 if (len) {
573 packet->options[end + OPT_CODE] = DHCP_PARAM_REQ;
574 packet->options[end + OPT_LEN] = len;
575 packet->options[end + OPT_DATA + len] = DHCP_END;
576 }
Denys Vlasenko7e6add12010-03-25 20:32:38 +0100577
Denys Vlasenkoc72c1d72010-10-20 22:08:16 +0200578 if (client_config.vendorclass)
579 udhcp_add_binary_option(packet, client_config.vendorclass);
580 if (client_config.hostname)
581 udhcp_add_binary_option(packet, client_config.hostname);
582 if (client_config.fqdn)
583 udhcp_add_binary_option(packet, client_config.fqdn);
584
Keith Younge6bb8d32011-03-07 03:18:46 +0100585 /* Request broadcast replies if we have no IP addr */
586 if ((option_mask32 & OPT_B) && packet->ciaddr == 0)
587 packet->flags |= htons(BROADCAST_FLAG);
588
Denys Vlasenko7e6add12010-03-25 20:32:38 +0100589 /* Add -x options if any */
590 {
591 struct option_set *curr = client_config.options;
592 while (curr) {
Denys Vlasenko7724c762010-03-26 09:32:09 +0100593 udhcp_add_binary_option(packet, curr->data);
Denys Vlasenko7e6add12010-03-25 20:32:38 +0100594 curr = curr->next;
595 }
596// if (client_config.sname)
597// strncpy((char*)packet->sname, client_config.sname, sizeof(packet->sname) - 1);
598// if (client_config.boot_file)
599// strncpy((char*)packet->file, client_config.boot_file, sizeof(packet->file) - 1);
600 }
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100601}
602
603/* RFC 2131
604 * 4.4.4 Use of broadcast and unicast
605 *
606 * The DHCP client broadcasts DHCPDISCOVER, DHCPREQUEST and DHCPINFORM
607 * messages, unless the client knows the address of a DHCP server.
608 * The client unicasts DHCPRELEASE messages to the server. Because
609 * the client is declining the use of the IP address supplied by the server,
610 * the client broadcasts DHCPDECLINE messages.
611 *
612 * When the DHCP client knows the address of a DHCP server, in either
613 * INIT or REBOOTING state, the client may use that address
614 * in the DHCPDISCOVER or DHCPREQUEST rather than the IP broadcast address.
615 * The client may also use unicast to send DHCPINFORM messages
616 * to a known DHCP server. If the client receives no response to DHCP
617 * messages sent to the IP address of a known DHCP server, the DHCP
618 * client reverts to using the IP broadcast address.
619 */
620
621static int raw_bcast_from_client_config_ifindex(struct dhcp_packet *packet)
622{
623 return udhcp_send_raw_packet(packet,
624 /*src*/ INADDR_ANY, CLIENT_PORT,
625 /*dst*/ INADDR_BROADCAST, SERVER_PORT, MAC_BCAST_ADDR,
626 client_config.ifindex);
627}
628
629/* Broadcast a DHCP discover packet to the network, with an optionally requested IP */
Denys Vlasenko0bb35e12010-10-21 12:33:10 +0200630/* NOINLINE: limit stack usage in caller */
Denys Vlasenkoc72c1d72010-10-20 22:08:16 +0200631static NOINLINE int send_discover(uint32_t xid, uint32_t requested)
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100632{
633 struct dhcp_packet packet;
634
Denys Vlasenkob3af65b2010-10-20 21:37:23 +0200635 /* Fill in: op, htype, hlen, cookie, chaddr fields,
636 * random xid field (we override it below),
637 * client-id option (unless -C), message type option:
638 */
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100639 init_packet(&packet, DHCPDISCOVER);
Denys Vlasenkob3af65b2010-10-20 21:37:23 +0200640
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100641 packet.xid = xid;
642 if (requested)
Denys Vlasenko7724c762010-03-26 09:32:09 +0100643 udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
Denys Vlasenkob3af65b2010-10-20 21:37:23 +0200644
645 /* Add options: maxsize,
646 * optionally: hostname, fqdn, vendorclass,
647 * "param req" option according to -O, options specified with -x
648 */
Denys Vlasenko7e6add12010-03-25 20:32:38 +0100649 add_client_options(&packet);
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100650
651 bb_info_msg("Sending discover...");
652 return raw_bcast_from_client_config_ifindex(&packet);
653}
654
655/* Broadcast a DHCP request message */
656/* RFC 2131 3.1 paragraph 3:
657 * "The client _broadcasts_ a DHCPREQUEST message..."
658 */
Denys Vlasenko0bb35e12010-10-21 12:33:10 +0200659/* NOINLINE: limit stack usage in caller */
Denys Vlasenkoc72c1d72010-10-20 22:08:16 +0200660static NOINLINE int send_select(uint32_t xid, uint32_t server, uint32_t requested)
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100661{
662 struct dhcp_packet packet;
663 struct in_addr addr;
664
Denys Vlasenkob3af65b2010-10-20 21:37:23 +0200665/*
666 * RFC 2131 4.3.2 DHCPREQUEST message
667 * ...
668 * If the DHCPREQUEST message contains a 'server identifier'
669 * option, the message is in response to a DHCPOFFER message.
670 * Otherwise, the message is a request to verify or extend an
671 * existing lease. If the client uses a 'client identifier'
672 * in a DHCPREQUEST message, it MUST use that same 'client identifier'
673 * in all subsequent messages. If the client included a list
674 * of requested parameters in a DHCPDISCOVER message, it MUST
675 * include that list in all subsequent messages.
676 */
677 /* Fill in: op, htype, hlen, cookie, chaddr fields,
678 * random xid field (we override it below),
679 * client-id option (unless -C), message type option:
680 */
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100681 init_packet(&packet, DHCPREQUEST);
Denys Vlasenkob3af65b2010-10-20 21:37:23 +0200682
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100683 packet.xid = xid;
Denys Vlasenko7724c762010-03-26 09:32:09 +0100684 udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
Denys Vlasenkob3af65b2010-10-20 21:37:23 +0200685
Denys Vlasenko7724c762010-03-26 09:32:09 +0100686 udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
Denys Vlasenkob3af65b2010-10-20 21:37:23 +0200687
688 /* Add options: maxsize,
689 * optionally: hostname, fqdn, vendorclass,
690 * "param req" option according to -O, and options specified with -x
691 */
Denys Vlasenko7e6add12010-03-25 20:32:38 +0100692 add_client_options(&packet);
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100693
694 addr.s_addr = requested;
695 bb_info_msg("Sending select for %s...", inet_ntoa(addr));
696 return raw_bcast_from_client_config_ifindex(&packet);
697}
698
699/* Unicast or broadcast a DHCP renew message */
Denys Vlasenko0bb35e12010-10-21 12:33:10 +0200700/* NOINLINE: limit stack usage in caller */
701static NOINLINE int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr)
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100702{
703 struct dhcp_packet packet;
704
Denys Vlasenkob3af65b2010-10-20 21:37:23 +0200705/*
706 * RFC 2131 4.3.2 DHCPREQUEST message
707 * ...
708 * DHCPREQUEST generated during RENEWING state:
709 *
710 * 'server identifier' MUST NOT be filled in, 'requested IP address'
711 * option MUST NOT be filled in, 'ciaddr' MUST be filled in with
712 * client's IP address. In this situation, the client is completely
713 * configured, and is trying to extend its lease. This message will
714 * be unicast, so no relay agents will be involved in its
715 * transmission. Because 'giaddr' is therefore not filled in, the
716 * DHCP server will trust the value in 'ciaddr', and use it when
717 * replying to the client.
718 */
719 /* Fill in: op, htype, hlen, cookie, chaddr fields,
720 * random xid field (we override it below),
721 * client-id option (unless -C), message type option:
722 */
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100723 init_packet(&packet, DHCPREQUEST);
Denys Vlasenkob3af65b2010-10-20 21:37:23 +0200724
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100725 packet.xid = xid;
726 packet.ciaddr = ciaddr;
Denys Vlasenkob3af65b2010-10-20 21:37:23 +0200727
728 /* Add options: maxsize,
729 * optionally: hostname, fqdn, vendorclass,
730 * "param req" option according to -O, and options specified with -x
731 */
Denys Vlasenko7e6add12010-03-25 20:32:38 +0100732 add_client_options(&packet);
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100733
734 bb_info_msg("Sending renew...");
735 if (server)
736 return udhcp_send_kernel_packet(&packet,
737 ciaddr, CLIENT_PORT,
738 server, SERVER_PORT);
739 return raw_bcast_from_client_config_ifindex(&packet);
740}
741
742#if ENABLE_FEATURE_UDHCPC_ARPING
743/* Broadcast a DHCP decline message */
Denys Vlasenko0bb35e12010-10-21 12:33:10 +0200744/* NOINLINE: limit stack usage in caller */
Denys Vlasenkoc72c1d72010-10-20 22:08:16 +0200745static NOINLINE int send_decline(uint32_t xid, uint32_t server, uint32_t requested)
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100746{
747 struct dhcp_packet packet;
748
Denys Vlasenkob3af65b2010-10-20 21:37:23 +0200749 /* Fill in: op, htype, hlen, cookie, chaddr, random xid fields,
750 * client-id option (unless -C), message type option:
751 */
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100752 init_packet(&packet, DHCPDECLINE);
Denys Vlasenkob3af65b2010-10-20 21:37:23 +0200753
754 /* RFC 2131 says DHCPDECLINE's xid is randomly selected by client,
755 * but in case the server is buggy and wants DHCPDECLINE's xid
756 * to match the xid which started entire handshake,
757 * we use the same xid we used in initial DHCPDISCOVER:
758 */
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100759 packet.xid = xid;
Denys Vlasenkob3af65b2010-10-20 21:37:23 +0200760 /* DHCPDECLINE uses "requested ip", not ciaddr, to store offered IP */
Denys Vlasenko7724c762010-03-26 09:32:09 +0100761 udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
Denys Vlasenkob3af65b2010-10-20 21:37:23 +0200762
Denys Vlasenko7724c762010-03-26 09:32:09 +0100763 udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100764
765 bb_info_msg("Sending decline...");
766 return raw_bcast_from_client_config_ifindex(&packet);
767}
768#endif
769
770/* Unicast a DHCP release message */
771static int send_release(uint32_t server, uint32_t ciaddr)
772{
773 struct dhcp_packet packet;
774
Denys Vlasenkob3af65b2010-10-20 21:37:23 +0200775 /* Fill in: op, htype, hlen, cookie, chaddr, random xid fields,
776 * client-id option (unless -C), message type option:
777 */
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100778 init_packet(&packet, DHCPRELEASE);
Denys Vlasenkob3af65b2010-10-20 21:37:23 +0200779
780 /* DHCPRELEASE uses ciaddr, not "requested ip", to store IP being released */
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100781 packet.ciaddr = ciaddr;
782
Denys Vlasenko7724c762010-03-26 09:32:09 +0100783 udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100784
785 bb_info_msg("Sending release...");
786 return udhcp_send_kernel_packet(&packet, ciaddr, CLIENT_PORT, server, SERVER_PORT);
787}
788
789/* Returns -1 on errors that are fatal for the socket, -2 for those that aren't */
Denys Vlasenko0bb35e12010-10-21 12:33:10 +0200790/* NOINLINE: limit stack usage in caller */
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100791static NOINLINE int udhcp_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd)
792{
793 int bytes;
794 struct ip_udp_dhcp_packet packet;
795 uint16_t check;
796
797 memset(&packet, 0, sizeof(packet));
798 bytes = safe_read(fd, &packet, sizeof(packet));
799 if (bytes < 0) {
800 log1("Packet read error, ignoring");
801 /* NB: possible down interface, etc. Caller should pause. */
802 return bytes; /* returns -1 */
803 }
804
805 if (bytes < (int) (sizeof(packet.ip) + sizeof(packet.udp))) {
806 log1("Packet is too short, ignoring");
807 return -2;
808 }
809
810 if (bytes < ntohs(packet.ip.tot_len)) {
811 /* packet is bigger than sizeof(packet), we did partial read */
812 log1("Oversized packet, ignoring");
813 return -2;
814 }
815
816 /* ignore any extra garbage bytes */
817 bytes = ntohs(packet.ip.tot_len);
818
819 /* make sure its the right packet for us, and that it passes sanity checks */
Denys Vlasenko7981d792011-10-20 10:34:05 +0200820 if (packet.ip.protocol != IPPROTO_UDP
821 || packet.ip.version != IPVERSION
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100822 || packet.ip.ihl != (sizeof(packet.ip) >> 2)
823 || packet.udp.dest != htons(CLIENT_PORT)
824 /* || bytes > (int) sizeof(packet) - can't happen */
825 || ntohs(packet.udp.len) != (uint16_t)(bytes - sizeof(packet.ip))
826 ) {
827 log1("Unrelated/bogus packet, ignoring");
828 return -2;
829 }
830
831 /* verify IP checksum */
832 check = packet.ip.check;
833 packet.ip.check = 0;
Baruch Siache8f36332011-09-07 17:52:37 +0200834 if (check != inet_cksum((uint16_t *)&packet.ip, sizeof(packet.ip))) {
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100835 log1("Bad IP header checksum, ignoring");
836 return -2;
837 }
838
839 /* verify UDP checksum. IP header has to be modified for this */
840 memset(&packet.ip, 0, offsetof(struct iphdr, protocol));
841 /* ip.xx fields which are not memset: protocol, check, saddr, daddr */
842 packet.ip.tot_len = packet.udp.len; /* yes, this is needed */
843 check = packet.udp.check;
844 packet.udp.check = 0;
Baruch Siache8f36332011-09-07 17:52:37 +0200845 if (check && check != inet_cksum((uint16_t *)&packet, bytes)) {
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100846 log1("Packet with bad UDP checksum received, ignoring");
847 return -2;
848 }
849
Denys Vlasenko7981d792011-10-20 10:34:05 +0200850 if (packet.data.cookie != htonl(DHCP_MAGIC)) {
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100851 bb_info_msg("Packet with bad magic, ignoring");
852 return -2;
853 }
Denys Vlasenko7981d792011-10-20 10:34:05 +0200854
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100855 log1("Got valid DHCP packet");
Denys Vlasenko7981d792011-10-20 10:34:05 +0200856 udhcp_dump_packet(&packet.data);
857
858 bytes -= sizeof(packet.ip) + sizeof(packet.udp);
859 memcpy(dhcp_pkt, &packet.data, bytes);
860 return bytes;
Denys Vlasenko501e35c2010-03-22 13:43:12 +0100861}
Denys Vlasenko6b24d532010-03-22 13:42:13 +0100862
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +0100863
864/*** Main ***/
865
866static int sockfd = -1;
867
868#define LISTEN_NONE 0
869#define LISTEN_KERNEL 1
870#define LISTEN_RAW 2
871static smallint listen_mode;
872
873/* initial state: (re)start DHCP negotiation */
874#define INIT_SELECTING 0
875/* discover was sent, DHCPOFFER reply received */
876#define REQUESTING 1
877/* select/renew was sent, DHCPACK reply received */
878#define BOUND 2
879/* half of lease passed, want to renew it by sending unicast renew requests */
880#define RENEWING 3
881/* renew requests were not answered, lease is almost over, send broadcast renew */
882#define REBINDING 4
883/* manually requested renew (SIGUSR1) */
884#define RENEW_REQUESTED 5
885/* release, possibly manually requested (SIGUSR2) */
886#define RELEASED 6
887static smallint state;
888
Denys Vlasenko6b24d532010-03-22 13:42:13 +0100889static int udhcp_raw_socket(int ifindex)
890{
891 int fd;
892 struct sockaddr_ll sock;
893
894 /*
895 * Comment:
896 *
897 * I've selected not to see LL header, so BPF doesn't see it, too.
898 * The filter may also pass non-IP and non-ARP packets, but we do
899 * a more complete check when receiving the message in userspace.
900 *
901 * and filter shamelessly stolen from:
902 *
903 * http://www.flamewarmaster.de/software/dhcpclient/
904 *
905 * There are a few other interesting ideas on that page (look under
906 * "Motivation"). Use of netlink events is most interesting. Think
907 * of various network servers listening for events and reconfiguring.
908 * That would obsolete sending HUP signals and/or make use of restarts.
909 *
910 * Copyright: 2006, 2007 Stefan Rompf <sux@loplof.de>.
911 * License: GPL v2.
912 *
913 * TODO: make conditional?
914 */
Denys Vlasenko6b24d532010-03-22 13:42:13 +0100915 static const struct sock_filter filter_instr[] = {
Vladislav Grishenko713e6d72011-02-14 04:50:30 +0100916 /* load 9th byte (protocol) */
Denys Vlasenko6b24d532010-03-22 13:42:13 +0100917 BPF_STMT(BPF_LD|BPF_B|BPF_ABS, 9),
Vladislav Grishenko713e6d72011-02-14 04:50:30 +0100918 /* jump to L1 if it is IPPROTO_UDP, else to L4 */
919 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, IPPROTO_UDP, 0, 6),
920 /* L1: load halfword from offset 6 (flags and frag offset) */
921 BPF_STMT(BPF_LD|BPF_H|BPF_ABS, 6),
922 /* jump to L4 if any bits in frag offset field are set, else to L2 */
923 BPF_JUMP(BPF_JMP|BPF_JSET|BPF_K, 0x1fff, 4, 0),
924 /* L2: skip IP header (load index reg with header len) */
925 BPF_STMT(BPF_LDX|BPF_B|BPF_MSH, 0),
926 /* load udp destination port from halfword[header_len + 2] */
927 BPF_STMT(BPF_LD|BPF_H|BPF_IND, 2),
928 /* jump to L3 if udp dport is CLIENT_PORT, else to L4 */
929 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 68, 0, 1),
930 /* L3: accept packet */
931 BPF_STMT(BPF_RET|BPF_K, 0xffffffff),
932 /* L4: discard packet */
933 BPF_STMT(BPF_RET|BPF_K, 0),
Denys Vlasenko6b24d532010-03-22 13:42:13 +0100934 };
935 static const struct sock_fprog filter_prog = {
936 .len = sizeof(filter_instr) / sizeof(filter_instr[0]),
937 /* casting const away: */
938 .filter = (struct sock_filter *) filter_instr,
939 };
940
941 log1("Opening raw socket on ifindex %d", ifindex); //log2?
942
943 fd = xsocket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP));
944 log1("Got raw socket fd %d", fd); //log2?
945
Vladislav Grishenko713e6d72011-02-14 04:50:30 +0100946 sock.sll_family = AF_PACKET;
947 sock.sll_protocol = htons(ETH_P_IP);
948 sock.sll_ifindex = ifindex;
949 xbind(fd, (struct sockaddr *) &sock, sizeof(sock));
950
951 if (CLIENT_PORT == 68) {
952 /* Use only if standard port is in use */
Denys Vlasenko6b24d532010-03-22 13:42:13 +0100953 /* Ignoring error (kernel may lack support for this) */
954 if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter_prog,
955 sizeof(filter_prog)) >= 0)
956 log1("Attached filter to raw socket fd %d", fd); // log?
957 }
958
Denys Vlasenko6b24d532010-03-22 13:42:13 +0100959 log1("Created raw socket");
960
961 return fd;
962}
963
Denis Vlasenko9cdfd142007-11-22 01:00:00 +0000964static void change_listen_mode(int new_mode)
Mike Frysinger7031f622006-05-08 03:20:50 +0000965{
Denys Vlasenko4945ed32009-06-17 11:58:11 +0200966 log1("Entering listen mode: %s",
Denys Vlasenko13ca4b12009-07-19 04:07:21 +0200967 new_mode != LISTEN_NONE
968 ? (new_mode == LISTEN_KERNEL ? "kernel" : "raw")
969 : "none"
970 );
Denis Vlasenko517413f2008-12-10 11:16:47 +0000971
972 listen_mode = new_mode;
Denis Vlasenkofbd29182007-04-07 01:05:47 +0000973 if (sockfd >= 0) {
974 close(sockfd);
975 sockfd = -1;
976 }
Denis Vlasenko517413f2008-12-10 11:16:47 +0000977 if (new_mode == LISTEN_KERNEL)
978 sockfd = udhcp_listen_socket(/*INADDR_ANY,*/ CLIENT_PORT, client_config.interface);
979 else if (new_mode != LISTEN_NONE)
980 sockfd = udhcp_raw_socket(client_config.ifindex);
Denys Vlasenko6b24d532010-03-22 13:42:13 +0100981 /* else LISTEN_NONE: sockfd stays closed */
Mike Frysinger7031f622006-05-08 03:20:50 +0000982}
983
Denys Vlasenko9ac55962011-03-12 05:37:54 +0100984/* Called only on SIGUSR1 */
Mike Frysinger7031f622006-05-08 03:20:50 +0000985static void perform_renew(void)
986{
Denis Vlasenko3538b9a2006-09-06 18:36:50 +0000987 bb_info_msg("Performing a DHCP renew");
Mike Frysinger7031f622006-05-08 03:20:50 +0000988 switch (state) {
989 case BOUND:
Denis Vlasenko9cdfd142007-11-22 01:00:00 +0000990 change_listen_mode(LISTEN_KERNEL);
Mike Frysinger7031f622006-05-08 03:20:50 +0000991 case RENEWING:
992 case REBINDING:
993 state = RENEW_REQUESTED;
994 break;
995 case RENEW_REQUESTED: /* impatient are we? fine, square 1 */
Rob Landley3f785612006-05-28 01:06:36 +0000996 udhcp_run_script(NULL, "deconfig");
Mike Frysinger7031f622006-05-08 03:20:50 +0000997 case REQUESTING:
998 case RELEASED:
Denis Vlasenko9cdfd142007-11-22 01:00:00 +0000999 change_listen_mode(LISTEN_RAW);
Mike Frysinger7031f622006-05-08 03:20:50 +00001000 state = INIT_SELECTING;
1001 break;
1002 case INIT_SELECTING:
1003 break;
1004 }
Mike Frysinger7031f622006-05-08 03:20:50 +00001005}
1006
Denis Vlasenkofc9e1082008-05-26 17:32:35 +00001007static void perform_release(uint32_t requested_ip, uint32_t server_addr)
Mike Frysinger7031f622006-05-08 03:20:50 +00001008{
Denis Vlasenko42b3dea2007-07-03 15:47:50 +00001009 char buffer[sizeof("255.255.255.255")];
Mike Frysinger7031f622006-05-08 03:20:50 +00001010 struct in_addr temp_addr;
1011
1012 /* send release packet */
1013 if (state == BOUND || state == RENEWING || state == REBINDING) {
1014 temp_addr.s_addr = server_addr;
Denis Vlasenko42b3dea2007-07-03 15:47:50 +00001015 strcpy(buffer, inet_ntoa(temp_addr));
Mike Frysinger7031f622006-05-08 03:20:50 +00001016 temp_addr.s_addr = requested_ip;
Denis Vlasenko3538b9a2006-09-06 18:36:50 +00001017 bb_info_msg("Unicasting a release of %s to %s",
Mike Frysinger7031f622006-05-08 03:20:50 +00001018 inet_ntoa(temp_addr), buffer);
1019 send_release(server_addr, requested_ip); /* unicast */
Rob Landley3f785612006-05-28 01:06:36 +00001020 udhcp_run_script(NULL, "deconfig");
Mike Frysinger7031f622006-05-08 03:20:50 +00001021 }
Denis Vlasenko3538b9a2006-09-06 18:36:50 +00001022 bb_info_msg("Entering released state");
Mike Frysinger7031f622006-05-08 03:20:50 +00001023
Denis Vlasenko9cdfd142007-11-22 01:00:00 +00001024 change_listen_mode(LISTEN_NONE);
Mike Frysinger7031f622006-05-08 03:20:50 +00001025 state = RELEASED;
Mike Frysinger7031f622006-05-08 03:20:50 +00001026}
1027
Denis Vlasenkoe2d3ded2006-11-27 23:43:28 +00001028static uint8_t* alloc_dhcp_option(int code, const char *str, int extra)
1029{
1030 uint8_t *storage;
Denys Vlasenko87fa2162010-03-20 18:06:23 +01001031 int len = strnlen(str, 255);
Denis Vlasenkoe2d3ded2006-11-27 23:43:28 +00001032 storage = xzalloc(len + extra + OPT_DATA);
1033 storage[OPT_CODE] = code;
1034 storage[OPT_LEN] = len + extra;
1035 memcpy(storage + extra + OPT_DATA, str, len);
1036 return storage;
1037}
1038
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +01001039#if BB_MMU
1040static void client_background(void)
1041{
1042 bb_daemonize(0);
1043 logmode &= ~LOGMODE_STDIO;
1044 /* rewrite pidfile, as our pid is different now */
1045 write_pidfile(client_config.pidfile);
1046}
1047#endif
1048
Denys Vlasenko9e244c72010-10-20 01:38:56 +02001049//usage:#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
1050//usage:# define IF_UDHCP_VERBOSE(...) __VA_ARGS__
1051//usage:#else
1052//usage:# define IF_UDHCP_VERBOSE(...)
1053//usage:#endif
1054//usage:#define udhcpc_trivial_usage
Keith Younge6bb8d32011-03-07 03:18:46 +01001055//usage: "[-fbnq"IF_UDHCP_VERBOSE("v")"oCRB] [-i IFACE] [-r IP] [-s PROG] [-p PIDFILE]\n"
Denys Vlasenko1cbdc032010-10-20 01:42:37 +02001056//usage: " [-H HOSTNAME] [-V VENDOR] [-x OPT:VAL]... [-O OPT]..." IF_FEATURE_UDHCP_PORT(" [-P N]")
Denys Vlasenko9e244c72010-10-20 01:38:56 +02001057//usage:#define udhcpc_full_usage "\n"
1058//usage: IF_LONG_OPTS(
1059//usage: "\n -i,--interface IFACE Interface to use (default eth0)"
1060//usage: "\n -p,--pidfile FILE Create pidfile"
Denys Vlasenko9e244c72010-10-20 01:38:56 +02001061//usage: "\n -s,--script PROG Run PROG at DHCP events (default "CONFIG_UDHCPC_DEFAULT_SCRIPT")"
Keith Younge6bb8d32011-03-07 03:18:46 +01001062//usage: "\n -B,--broadcast Request broadcast replies"
Denys Vlasenko9e244c72010-10-20 01:38:56 +02001063//usage: "\n -t,--retries N Send up to N discover packets"
1064//usage: "\n -T,--timeout N Pause between packets (default 3 seconds)"
1065//usage: "\n -A,--tryagain N Wait N seconds after failure (default 20)"
1066//usage: "\n -f,--foreground Run in foreground"
1067//usage: USE_FOR_MMU(
1068//usage: "\n -b,--background Background if lease is not obtained"
1069//usage: )
Denys Vlasenko9e244c72010-10-20 01:38:56 +02001070//usage: "\n -n,--now Exit if lease is not obtained"
1071//usage: "\n -q,--quit Exit after obtaining lease"
1072//usage: "\n -R,--release Release IP on exit"
Denys Vlasenkoc59e06e2010-10-20 16:10:59 +02001073//usage: "\n -S,--syslog Log to syslog too"
Denys Vlasenko9e244c72010-10-20 01:38:56 +02001074//usage: IF_FEATURE_UDHCP_PORT(
1075//usage: "\n -P,--client-port N Use port N (default 68)"
1076//usage: )
1077//usage: IF_FEATURE_UDHCPC_ARPING(
1078//usage: "\n -a,--arping Use arping to validate offered address"
1079//usage: )
Denys Vlasenko1cbdc032010-10-20 01:42:37 +02001080//usage: "\n -O,--request-option OPT Request option OPT from server (cumulative)"
Denys Vlasenko9e244c72010-10-20 01:38:56 +02001081//usage: "\n -o,--no-default-options Don't request any options (unless -O is given)"
Denys Vlasenkoc59e06e2010-10-20 16:10:59 +02001082//usage: "\n -r,--request IP Request this IP address"
Denys Vlasenko9e244c72010-10-20 01:38:56 +02001083//usage: "\n -x OPT:VAL Include option OPT in sent packets (cumulative)"
Denys Vlasenkoc59e06e2010-10-20 16:10:59 +02001084//usage: "\n Examples of string, numeric, and hex byte opts:"
1085//usage: "\n -x hostname:bbox - option 12"
1086//usage: "\n -x lease:3600 - option 51 (lease time)"
1087//usage: "\n -x 0x3d:0100BEEFC0FFEE - option 61 (client id)"
Denys Vlasenko9e244c72010-10-20 01:38:56 +02001088//usage: "\n -F,--fqdn NAME Ask server to update DNS mapping for NAME"
1089//usage: "\n -H,-h,--hostname NAME Send NAME as client hostname (default none)"
1090//usage: "\n -V,--vendorclass VENDOR Vendor identifier (default 'udhcp VERSION')"
Denys Vlasenko1cbdc032010-10-20 01:42:37 +02001091//usage: "\n -C,--clientid-none Don't send MAC as client identifier"
Denys Vlasenko9e244c72010-10-20 01:38:56 +02001092//usage: IF_UDHCP_VERBOSE(
1093//usage: "\n -v Verbose"
1094//usage: )
1095//usage: )
1096//usage: IF_NOT_LONG_OPTS(
1097//usage: "\n -i IFACE Interface to use (default eth0)"
1098//usage: "\n -p FILE Create pidfile"
Denys Vlasenko9e244c72010-10-20 01:38:56 +02001099//usage: "\n -s PROG Run PROG at DHCP events (default "CONFIG_UDHCPC_DEFAULT_SCRIPT")"
Keith Younge6bb8d32011-03-07 03:18:46 +01001100//usage: "\n -B Request broadcast replies"
Denys Vlasenko9e244c72010-10-20 01:38:56 +02001101//usage: "\n -t N Send up to N discover packets"
1102//usage: "\n -T N Pause between packets (default 3 seconds)"
1103//usage: "\n -A N Wait N seconds (default 20) after failure"
Denys Vlasenko9e244c72010-10-20 01:38:56 +02001104//usage: "\n -f Run in foreground"
1105//usage: USE_FOR_MMU(
1106//usage: "\n -b Background if lease is not obtained"
1107//usage: )
Denys Vlasenko9e244c72010-10-20 01:38:56 +02001108//usage: "\n -n Exit if lease is not obtained"
1109//usage: "\n -q Exit after obtaining lease"
1110//usage: "\n -R Release IP on exit"
Denys Vlasenkoc59e06e2010-10-20 16:10:59 +02001111//usage: "\n -S Log to syslog too"
Denys Vlasenko9e244c72010-10-20 01:38:56 +02001112//usage: IF_FEATURE_UDHCP_PORT(
1113//usage: "\n -P N Use port N (default 68)"
1114//usage: )
1115//usage: IF_FEATURE_UDHCPC_ARPING(
1116//usage: "\n -a Use arping to validate offered address"
1117//usage: )
Denys Vlasenkoc59e06e2010-10-20 16:10:59 +02001118//usage: "\n -O OPT Request option OPT from server (cumulative)"
1119//usage: "\n -o Don't request any options (unless -O is given)"
1120//usage: "\n -r IP Request this IP address"
1121//usage: "\n -x OPT:VAL Include option OPT in sent packets (cumulative)"
1122//usage: "\n Examples of string, numeric, and hex byte opts:"
1123//usage: "\n -x hostname:bbox - option 12"
1124//usage: "\n -x lease:3600 - option 51 (lease time)"
1125//usage: "\n -x 0x3d:0100BEEFC0FFEE - option 61 (client id)"
Denys Vlasenko9e244c72010-10-20 01:38:56 +02001126//usage: "\n -F NAME Ask server to update DNS mapping for NAME"
1127//usage: "\n -H,-h NAME Send NAME as client hostname (default none)"
1128//usage: "\n -V VENDOR Vendor identifier (default 'udhcp VERSION')"
Denys Vlasenko1cbdc032010-10-20 01:42:37 +02001129//usage: "\n -C Don't send MAC as client identifier"
Denys Vlasenko9e244c72010-10-20 01:38:56 +02001130//usage: IF_UDHCP_VERBOSE(
1131//usage: "\n -v Verbose"
1132//usage: )
1133//usage: )
Denys Vlasenko8993c3f2010-12-25 06:21:54 +01001134//usage: "\nSignals:"
1135//usage: "\n USR1 Renew current lease"
1136//usage: "\n USR2 Release current lease"
1137
Denys Vlasenko9e244c72010-10-20 01:38:56 +02001138
Denis Vlasenko9b49a5e2007-10-11 10:05:36 +00001139int udhcpc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
Denis Vlasenkoa60f84e2008-07-05 09:18:54 +00001140int udhcpc_main(int argc UNUSED_PARAM, char **argv)
Mike Frysinger7031f622006-05-08 03:20:50 +00001141{
1142 uint8_t *temp, *message;
Denys Vlasenko1cbdc032010-10-20 01:42:37 +02001143 const char *str_V, *str_h, *str_F, *str_r;
Denis Vlasenko5e34ff22009-04-21 11:09:40 +00001144 IF_FEATURE_UDHCP_PORT(char *str_P;)
Denys Vlasenko5d374e92010-10-20 22:26:38 +02001145 void *clientid_mac_ptr;
Denis Vlasenko19183682007-12-10 07:03:38 +00001146 llist_t *list_O = NULL;
Denys Vlasenko7e6add12010-03-25 20:32:38 +01001147 llist_t *list_x = NULL;
Denis Vlasenko68af8e72007-11-22 21:41:14 +00001148 int tryagain_timeout = 20;
1149 int discover_timeout = 3;
1150 int discover_retries = 3;
Denis Vlasenkofc9e1082008-05-26 17:32:35 +00001151 uint32_t server_addr = server_addr; /* for compiler */
1152 uint32_t requested_ip = 0;
Denis Vlasenko42b3dea2007-07-03 15:47:50 +00001153 uint32_t xid = 0;
Denis Vlasenko9cdfd142007-11-22 01:00:00 +00001154 uint32_t lease_seconds = 0; /* can be given as 32-bit quantity */
Denis Vlasenkob539c842007-11-29 08:17:45 +00001155 int packet_num;
Denis Vlasenkofc9e1082008-05-26 17:32:35 +00001156 int timeout; /* must be signed */
Denis Vlasenko19903f02008-05-21 07:03:03 +00001157 unsigned already_waited_sec;
Denis Vlasenkoe2d3ded2006-11-27 23:43:28 +00001158 unsigned opt;
Mike Frysinger7031f622006-05-08 03:20:50 +00001159 int max_fd;
Denis Vlasenkoe2d3ded2006-11-27 23:43:28 +00001160 int retval;
Denis Vlasenkoe2d3ded2006-11-27 23:43:28 +00001161 struct timeval tv;
Denys Vlasenko31af3d52009-06-17 11:57:09 +02001162 struct dhcp_packet packet;
Denis Vlasenko80edead2007-08-02 22:31:05 +00001163 fd_set rfds;
Mike Frysinger7031f622006-05-08 03:20:50 +00001164
Denys Vlasenko5d374e92010-10-20 22:26:38 +02001165 /* Default options */
Denis Vlasenko5e34ff22009-04-21 11:09:40 +00001166 IF_FEATURE_UDHCP_PORT(SERVER_PORT = 67;)
1167 IF_FEATURE_UDHCP_PORT(CLIENT_PORT = 68;)
Denis Vlasenkoe2d3ded2006-11-27 23:43:28 +00001168 client_config.interface = "eth0";
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +01001169 client_config.script = CONFIG_UDHCPC_DEFAULT_SCRIPT;
Denys Vlasenko87fa2162010-03-20 18:06:23 +01001170 str_V = "udhcp "BB_VER;
Mike Frysinger7031f622006-05-08 03:20:50 +00001171
Denis Vlasenkoe2d3ded2006-11-27 23:43:28 +00001172 /* Parse command line */
Denys Vlasenko1cbdc032010-10-20 01:42:37 +02001173 /* O,x: list; -T,-t,-A take numeric param */
Leonid Lisovskiy6c9c0a12011-10-18 00:35:47 +02001174 opt_complementary = "O::x::T+:t+:A+" IF_UDHCP_VERBOSE(":vv") ;
Denys Vlasenkof3b92d32009-06-19 12:10:38 +02001175 IF_LONG_OPTS(applet_long_options = udhcpc_longopts;)
Keith Younge6bb8d32011-03-07 03:18:46 +01001176 opt = getopt32(argv, "CV:H:h:F:i:np:qRr:s:T:t:SA:O:ox:fB"
Denis Vlasenko21765fa2008-06-13 20:44:05 +00001177 USE_FOR_MMU("b")
Denis Vlasenko5e34ff22009-04-21 11:09:40 +00001178 IF_FEATURE_UDHCPC_ARPING("a")
1179 IF_FEATURE_UDHCP_PORT("P:")
Denys Vlasenkoac906fa2009-06-17 11:54:52 +02001180 "v"
Denys Vlasenko1cbdc032010-10-20 01:42:37 +02001181 , &str_V, &str_h, &str_h, &str_F
Denis Vlasenko21765fa2008-06-13 20:44:05 +00001182 , &client_config.interface, &client_config.pidfile, &str_r /* i,p */
1183 , &client_config.script /* s */
1184 , &discover_timeout, &discover_retries, &tryagain_timeout /* T,t,A */
Denis Vlasenko19183682007-12-10 07:03:38 +00001185 , &list_O
Denys Vlasenko7e6add12010-03-25 20:32:38 +01001186 , &list_x
Denis Vlasenko5e34ff22009-04-21 11:09:40 +00001187 IF_FEATURE_UDHCP_PORT(, &str_P)
Leonid Lisovskiy6c9c0a12011-10-18 00:35:47 +02001188 IF_UDHCP_VERBOSE(, &dhcp_verbose)
Denis Vlasenkoe2d3ded2006-11-27 23:43:28 +00001189 );
Denis Vlasenko68af8e72007-11-22 21:41:14 +00001190 if (opt & (OPT_h|OPT_H))
Denis Vlasenkoe2d3ded2006-11-27 23:43:28 +00001191 client_config.hostname = alloc_dhcp_option(DHCP_HOST_NAME, str_h, 0);
1192 if (opt & OPT_F) {
Denys Vlasenko87fa2162010-03-20 18:06:23 +01001193 /* FQDN option format: [0x51][len][flags][0][0]<fqdn> */
Denis Vlasenkoe2d3ded2006-11-27 23:43:28 +00001194 client_config.fqdn = alloc_dhcp_option(DHCP_FQDN, str_F, 3);
Denys Vlasenko87fa2162010-03-20 18:06:23 +01001195 /* Flag bits: 0000NEOS
1196 * S: 1 = Client requests server to update A RR in DNS as well as PTR
1197 * O: 1 = Server indicates to client that DNS has been updated regardless
1198 * E: 1 = Name is in DNS format, i.e. <4>host<6>domain<3>com<0>,
1199 * not "host.domain.com". Format 0 is obsolete.
1200 * N: 1 = Client requests server to not update DNS (S must be 0 then)
1201 * Two [0] bytes which follow are deprecated and must be 0.
1202 */
Denis Vlasenkoe2d3ded2006-11-27 23:43:28 +00001203 client_config.fqdn[OPT_DATA + 0] = 0x1;
Denys Vlasenko87fa2162010-03-20 18:06:23 +01001204 /*client_config.fqdn[OPT_DATA + 1] = 0; - xzalloc did it */
1205 /*client_config.fqdn[OPT_DATA + 2] = 0; */
Denis Vlasenkoe2d3ded2006-11-27 23:43:28 +00001206 }
Denis Vlasenkoe2d3ded2006-11-27 23:43:28 +00001207 if (opt & OPT_r)
1208 requested_ip = inet_addr(str_r);
Denis Vlasenkod55fe3e2008-02-04 13:12:16 +00001209#if ENABLE_FEATURE_UDHCP_PORT
1210 if (opt & OPT_P) {
1211 CLIENT_PORT = xatou16(str_P);
1212 SERVER_PORT = CLIENT_PORT - 1;
1213 }
1214#endif
Denis Vlasenko2e4c3c42008-04-02 13:04:19 +00001215 if (opt & OPT_o)
1216 client_config.no_default_options = 1;
Denis Vlasenko19183682007-12-10 07:03:38 +00001217 while (list_O) {
Denis Vlasenko18c93022008-08-27 22:29:43 +00001218 char *optstr = llist_pop(&list_O);
Denys Vlasenko5d3aace2011-06-04 05:07:16 +02001219 unsigned n = bb_strtou(optstr, NULL, 0);
1220 if (errno || n > 254) {
1221 n = udhcp_option_idx(optstr);
1222 n = dhcp_optflags[n].code;
1223 }
Denis Vlasenko19183682007-12-10 07:03:38 +00001224 client_config.opt_mask[n >> 3] |= 1 << (n & 7);
Denis Vlasenko19183682007-12-10 07:03:38 +00001225 }
Denys Vlasenko7e6add12010-03-25 20:32:38 +01001226 while (list_x) {
Denys Vlasenko7e6add12010-03-25 20:32:38 +01001227 char *optstr = llist_pop(&list_x);
1228 char *colon = strchr(optstr, ':');
1229 if (colon)
Denys Vlasenko7e6add12010-03-25 20:32:38 +01001230 *colon = ' ';
Denys Vlasenko9c0ea862010-04-04 02:12:03 +02001231 /* now it looks similar to udhcpd's config file line:
1232 * "optname optval", using the common routine: */
Denys Vlasenko7e6add12010-03-25 20:32:38 +01001233 udhcp_str2optset(optstr, &client_config.options);
1234 }
Mike Frysinger7031f622006-05-08 03:20:50 +00001235
Denys Vlasenko26918dd2009-06-16 12:04:23 +02001236 if (udhcp_read_interface(client_config.interface,
1237 &client_config.ifindex,
1238 NULL,
1239 client_config.client_mac)
1240 ) {
Mike Frysinger7031f622006-05-08 03:20:50 +00001241 return 1;
Denys Vlasenko26918dd2009-06-16 12:04:23 +02001242 }
1243
Denys Vlasenko5d374e92010-10-20 22:26:38 +02001244 clientid_mac_ptr = NULL;
Denys Vlasenko1cbdc032010-10-20 01:42:37 +02001245 if (!(opt & OPT_C) && !udhcp_find_option(client_config.options, DHCP_CLIENT_ID)) {
1246 /* not suppressed and not set, set the default client ID */
Denys Vlasenko87fa2162010-03-20 18:06:23 +01001247 client_config.clientid = alloc_dhcp_option(DHCP_CLIENT_ID, "", 7);
1248 client_config.clientid[OPT_DATA] = 1; /* type: ethernet */
Denys Vlasenko5d374e92010-10-20 22:26:38 +02001249 clientid_mac_ptr = client_config.clientid + OPT_DATA+1;
1250 memcpy(clientid_mac_ptr, client_config.client_mac, 6);
Denys Vlasenko87fa2162010-03-20 18:06:23 +01001251 }
1252 if (str_V[0] != '\0')
1253 client_config.vendorclass = alloc_dhcp_option(DHCP_VENDOR, str_V, 0);
Denis Vlasenko21765fa2008-06-13 20:44:05 +00001254#if !BB_MMU
1255 /* on NOMMU reexec (i.e., background) early */
1256 if (!(opt & OPT_f)) {
1257 bb_daemonize_or_rexec(0 /* flags */, argv);
Denis Vlasenkoa19e6492009-03-11 14:40:00 +00001258 logmode = LOGMODE_NONE;
Denis Vlasenko21765fa2008-06-13 20:44:05 +00001259 }
1260#endif
1261 if (opt & OPT_S) {
Denis Vlasenko5e4fda02009-03-08 23:46:48 +00001262 openlog(applet_name, LOG_PID, LOG_DAEMON);
Denis Vlasenko21765fa2008-06-13 20:44:05 +00001263 logmode |= LOGMODE_SYSLOG;
1264 }
Mike Frysinger7031f622006-05-08 03:20:50 +00001265
Denis Vlasenko80edead2007-08-02 22:31:05 +00001266 /* Make sure fd 0,1,2 are open */
1267 bb_sanitize_stdio();
1268 /* Equivalent of doing a fflush after every \n */
1269 setlinebuf(stdout);
Denis Vlasenko80edead2007-08-02 22:31:05 +00001270 /* Create pidfile */
1271 write_pidfile(client_config.pidfile);
Denis Vlasenko21765fa2008-06-13 20:44:05 +00001272 /* Goes to stdout (unless NOMMU) and possibly syslog */
Denis Vlasenkodef88982007-10-07 17:06:01 +00001273 bb_info_msg("%s (v"BB_VER") started", applet_name);
Denys Vlasenko4248c332009-06-26 23:23:16 +02001274 /* Set up the signal pipe */
Mike Frysinger7031f622006-05-08 03:20:50 +00001275 udhcp_sp_setup();
Denys Vlasenko8d114452010-03-22 13:44:09 +01001276 /* We want random_xid to be random... */
1277 srand(monotonic_us());
Mike Frysinger7031f622006-05-08 03:20:50 +00001278
1279 state = INIT_SELECTING;
Rob Landley3f785612006-05-28 01:06:36 +00001280 udhcp_run_script(NULL, "deconfig");
Denis Vlasenko9cdfd142007-11-22 01:00:00 +00001281 change_listen_mode(LISTEN_RAW);
Denis Vlasenkob539c842007-11-29 08:17:45 +00001282 packet_num = 0;
Denis Vlasenkofc9e1082008-05-26 17:32:35 +00001283 timeout = 0;
Denis Vlasenko19903f02008-05-21 07:03:03 +00001284 already_waited_sec = 0;
Mike Frysinger7031f622006-05-08 03:20:50 +00001285
Denis Vlasenko9cdfd142007-11-22 01:00:00 +00001286 /* Main event loop. select() waits on signal pipe and possibly
1287 * on sockfd.
1288 * "continue" statements in code below jump to the top of the loop.
1289 */
Mike Frysinger7031f622006-05-08 03:20:50 +00001290 for (;;) {
Denis Vlasenkoec64a572009-01-14 00:28:03 +00001291 /* silence "uninitialized!" warning */
1292 unsigned timestamp_before_wait = timestamp_before_wait;
Mike Frysinger7031f622006-05-08 03:20:50 +00001293
Denis Vlasenko517413f2008-12-10 11:16:47 +00001294 //bb_error_msg("sockfd:%d, listen_mode:%d", sockfd, listen_mode);
1295
1296 /* Was opening raw or udp socket here
1297 * if (listen_mode != LISTEN_NONE && sockfd < 0),
1298 * but on fast network renew responses return faster
1299 * than we open sockets. Thus this code is moved
1300 * to change_listen_mode(). Thus we open listen socket
1301 * BEFORE we send renew request (see "case BOUND:"). */
1302
Denis Vlasenkofbd29182007-04-07 01:05:47 +00001303 max_fd = udhcp_sp_fd_set(&rfds, sockfd);
Mike Frysinger7031f622006-05-08 03:20:50 +00001304
Denis Vlasenko19903f02008-05-21 07:03:03 +00001305 tv.tv_sec = timeout - already_waited_sec;
Denis Vlasenkob2342912008-05-21 07:02:16 +00001306 tv.tv_usec = 0;
Denys Vlasenko8d114452010-03-22 13:44:09 +01001307 retval = 0;
1308 /* If we already timed out, fall through with retval = 0, else... */
Denys Vlasenko13ca4b12009-07-19 04:07:21 +02001309 if ((int)tv.tv_sec > 0) {
Denis Vlasenkob2342912008-05-21 07:02:16 +00001310 timestamp_before_wait = (unsigned)monotonic_sec();
Denys Vlasenkoac906fa2009-06-17 11:54:52 +02001311 log1("Waiting on select...");
Mike Frysinger7031f622006-05-08 03:20:50 +00001312 retval = select(max_fd + 1, &rfds, NULL, NULL, &tv);
Denis Vlasenkob2342912008-05-21 07:02:16 +00001313 if (retval < 0) {
1314 /* EINTR? A signal was caught, don't panic */
Denys Vlasenko13ca4b12009-07-19 04:07:21 +02001315 if (errno == EINTR) {
1316 already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait;
Denis Vlasenkob2342912008-05-21 07:02:16 +00001317 continue;
Denys Vlasenko13ca4b12009-07-19 04:07:21 +02001318 }
Denis Vlasenko80edead2007-08-02 22:31:05 +00001319 /* Else: an error occured, panic! */
1320 bb_perror_msg_and_die("select");
1321 }
Denis Vlasenko9cdfd142007-11-22 01:00:00 +00001322 }
1323
1324 /* If timeout dropped to zero, time to become active:
1325 * resend discover/renew/whatever
1326 */
1327 if (retval == 0) {
Denys Vlasenkoa5048fa2010-10-20 21:38:29 +02001328 /* When running on a bridge, the ifindex may have changed
1329 * (e.g. if member interfaces were added/removed
1330 * or if the status of the bridge changed).
1331 * Refresh ifindex and client_mac:
1332 */
Denys Vlasenko5d374e92010-10-20 22:26:38 +02001333 if (udhcp_read_interface(client_config.interface,
1334 &client_config.ifindex,
1335 NULL,
1336 client_config.client_mac)
1337 ) {
1338 return 1; /* iface is gone? */
1339 }
1340 if (clientid_mac_ptr)
1341 memcpy(clientid_mac_ptr, client_config.client_mac, 6);
Denys Vlasenkoa5048fa2010-10-20 21:38:29 +02001342
Denis Vlasenkof1980f62008-09-26 09:34:59 +00001343 /* We will restart the wait in any case */
Denis Vlasenko19903f02008-05-21 07:03:03 +00001344 already_waited_sec = 0;
1345
Mike Frysinger7031f622006-05-08 03:20:50 +00001346 switch (state) {
1347 case INIT_SELECTING:
Denis Vlasenko223bc972007-11-22 00:58:49 +00001348 if (packet_num < discover_retries) {
Mike Frysinger7031f622006-05-08 03:20:50 +00001349 if (packet_num == 0)
1350 xid = random_xid();
Denys Vlasenko13ca4b12009-07-19 04:07:21 +02001351 /* broadcast */
1352 send_discover(xid, requested_ip);
Denis Vlasenko9cdfd142007-11-22 01:00:00 +00001353 timeout = discover_timeout;
Mike Frysinger7031f622006-05-08 03:20:50 +00001354 packet_num++;
Denis Vlasenko9cdfd142007-11-22 01:00:00 +00001355 continue;
Mike Frysinger7031f622006-05-08 03:20:50 +00001356 }
Denis Vlasenkocdb0b652008-09-26 09:34:15 +00001357 leasefail:
Denis Vlasenko9cdfd142007-11-22 01:00:00 +00001358 udhcp_run_script(NULL, "leasefail");
Denis Vlasenko21765fa2008-06-13 20:44:05 +00001359#if BB_MMU /* -b is not supported on NOMMU */
1360 if (opt & OPT_b) { /* background if no lease */
Denis Vlasenko9cdfd142007-11-22 01:00:00 +00001361 bb_info_msg("No lease, forking to background");
1362 client_background();
Denis Vlasenko21765fa2008-06-13 20:44:05 +00001363 /* do not background again! */
1364 opt = ((opt & ~OPT_b) | OPT_f);
1365 } else
1366#endif
1367 if (opt & OPT_n) { /* abort if no lease */
Denis Vlasenko9cdfd142007-11-22 01:00:00 +00001368 bb_info_msg("No lease, failing");
1369 retval = 1;
1370 goto ret;
1371 }
Denis Vlasenko6de89942008-05-21 07:05:06 +00001372 /* wait before trying again */
Denis Vlasenko9cdfd142007-11-22 01:00:00 +00001373 timeout = tryagain_timeout;
1374 packet_num = 0;
1375 continue;
Mike Frysinger7031f622006-05-08 03:20:50 +00001376 case REQUESTING:
Denis Vlasenko223bc972007-11-22 00:58:49 +00001377 if (packet_num < discover_retries) {
Denys Vlasenko13ca4b12009-07-19 04:07:21 +02001378 /* send broadcast select packet */
1379 send_select(xid, server_addr, requested_ip);
Denis Vlasenko6de89942008-05-21 07:05:06 +00001380 timeout = discover_timeout;
Mike Frysinger7031f622006-05-08 03:20:50 +00001381 packet_num++;
Denis Vlasenko9cdfd142007-11-22 01:00:00 +00001382 continue;
Mike Frysinger7031f622006-05-08 03:20:50 +00001383 }
Denys Vlasenko13ca4b12009-07-19 04:07:21 +02001384 /* Timed out, go back to init state.
1385 * "discover...select...discover..." loops
Denis Vlasenko7d9399e2008-09-26 22:21:03 +00001386 * were seen in the wild. Treat them similarly
Denis Vlasenkocdb0b652008-09-26 09:34:15 +00001387 * to "no response to discover" case */
Denys Vlasenko13ca4b12009-07-19 04:07:21 +02001388 change_listen_mode(LISTEN_RAW);
Denis Vlasenko7d9399e2008-09-26 22:21:03 +00001389 state = INIT_SELECTING;
Denys Vlasenko13ca4b12009-07-19 04:07:21 +02001390 goto leasefail;
Mike Frysinger7031f622006-05-08 03:20:50 +00001391 case BOUND:
Denys Vlasenko7d6a7912009-07-19 04:24:23 +02001392 /* 1/2 lease passed, enter renewing state */
Denys Vlasenko13ca4b12009-07-19 04:07:21 +02001393 state = RENEWING;
Denys Vlasenko9ac55962011-03-12 05:37:54 +01001394 client_config.first_secs = 0; /* make secs field count from 0 */
Denis Vlasenko9cdfd142007-11-22 01:00:00 +00001395 change_listen_mode(LISTEN_KERNEL);
Denys Vlasenkoac906fa2009-06-17 11:54:52 +02001396 log1("Entering renew state");
Mike Frysinger7031f622006-05-08 03:20:50 +00001397 /* fall right through */
Denys Vlasenko13ca4b12009-07-19 04:07:21 +02001398 case RENEW_REQUESTED: /* manual (SIGUSR1) renew */
1399 case_RENEW_REQUESTED:
Mike Frysinger7031f622006-05-08 03:20:50 +00001400 case RENEWING:
Denis Vlasenko19903f02008-05-21 07:03:03 +00001401 if (timeout > 60) {
Denys Vlasenko7d6a7912009-07-19 04:24:23 +02001402 /* send an unicast renew request */
1403 /* Sometimes observed to fail (EADDRNOTAVAIL) to bind
1404 * a new UDP socket for sending inside send_renew.
1405 * I hazard to guess existing listening socket
1406 * is somehow conflicting with it, but why is it
1407 * not deterministic then?! Strange.
Denys Vlasenko753a3ce2009-07-19 04:27:10 +02001408 * Anyway, it does recover by eventually failing through
Denys Vlasenko7d6a7912009-07-19 04:24:23 +02001409 * into INIT_SELECTING state.
1410 */
Denys Vlasenko13ca4b12009-07-19 04:07:21 +02001411 send_renew(xid, server_addr, requested_ip);
Denis Vlasenko19903f02008-05-21 07:03:03 +00001412 timeout >>= 1;
Denis Vlasenko9cdfd142007-11-22 01:00:00 +00001413 continue;
Mike Frysinger7031f622006-05-08 03:20:50 +00001414 }
Denis Vlasenko9cdfd142007-11-22 01:00:00 +00001415 /* Timed out, enter rebinding state */
Denys Vlasenkoac906fa2009-06-17 11:54:52 +02001416 log1("Entering rebinding state");
Denis Vlasenko9cdfd142007-11-22 01:00:00 +00001417 state = REBINDING;
Denis Vlasenko6de89942008-05-21 07:05:06 +00001418 /* fall right through */
Mike Frysinger7031f622006-05-08 03:20:50 +00001419 case REBINDING:
Denys Vlasenko219757f2009-10-08 23:05:46 +02001420 /* Switch to bcast receive */
1421 change_listen_mode(LISTEN_RAW);
Denis Vlasenko9cdfd142007-11-22 01:00:00 +00001422 /* Lease is *really* about to run out,
1423 * try to find DHCP server using broadcast */
Denis Vlasenko19903f02008-05-21 07:03:03 +00001424 if (timeout > 0) {
Denys Vlasenko7d6a7912009-07-19 04:24:23 +02001425 /* send a broadcast renew request */
Denys Vlasenko13ca4b12009-07-19 04:07:21 +02001426 send_renew(xid, 0 /*INADDR_ANY*/, requested_ip);
Denis Vlasenko19903f02008-05-21 07:03:03 +00001427 timeout >>= 1;
Denis Vlasenko9cdfd142007-11-22 01:00:00 +00001428 continue;
Mike Frysinger7031f622006-05-08 03:20:50 +00001429 }
Denis Vlasenko9cdfd142007-11-22 01:00:00 +00001430 /* Timed out, enter init state */
1431 bb_info_msg("Lease lost, entering init state");
1432 udhcp_run_script(NULL, "deconfig");
Denis Vlasenko9cdfd142007-11-22 01:00:00 +00001433 state = INIT_SELECTING;
Denys Vlasenko9ac55962011-03-12 05:37:54 +01001434 client_config.first_secs = 0; /* make secs field count from 0 */
Denis Vlasenko19903f02008-05-21 07:03:03 +00001435 /*timeout = 0; - already is */
Denis Vlasenko9cdfd142007-11-22 01:00:00 +00001436 packet_num = 0;
1437 continue;
1438 /* case RELEASED: */
Mike Frysinger7031f622006-05-08 03:20:50 +00001439 }
Denis Vlasenko9cdfd142007-11-22 01:00:00 +00001440 /* yah, I know, *you* say it would never happen */
1441 timeout = INT_MAX;
1442 continue; /* back to main loop */
Denys Vlasenko4248c332009-06-26 23:23:16 +02001443 } /* if select timed out */
1444
1445 /* select() didn't timeout, something happened */
1446
1447 /* Is it a signal? */
1448 /* note: udhcp_sp_read checks FD_ISSET before reading */
1449 switch (udhcp_sp_read(&rfds)) {
1450 case SIGUSR1:
Denys Vlasenko9ac55962011-03-12 05:37:54 +01001451 client_config.first_secs = 0; /* make secs field count from 0 */
Vladislav Grishenko6464f152011-10-18 01:37:47 +02001452 already_waited_sec = 0;
Denys Vlasenko4248c332009-06-26 23:23:16 +02001453 perform_renew();
Vladislav Grishenko6464f152011-10-18 01:37:47 +02001454 if (state == RENEW_REQUESTED) {
1455 /* We might be either on the same network
1456 * (in which case renew might work),
1457 * or we might be on a completely different one
1458 * (in which case renew won't ever succeed).
1459 * For the second case, must make sure timeout
1460 * is not too big, or else we can send
1461 * futile renew requests for hours.
1462 * (Ab)use -A TIMEOUT value (usually 20 sec)
1463 * as a cap on the timeout.
1464 */
1465 if (timeout > tryagain_timeout)
1466 timeout = tryagain_timeout;
Denys Vlasenko13ca4b12009-07-19 04:07:21 +02001467 goto case_RENEW_REQUESTED;
Vladislav Grishenko6464f152011-10-18 01:37:47 +02001468 }
Denys Vlasenko4248c332009-06-26 23:23:16 +02001469 /* Start things over */
1470 packet_num = 0;
Denys Vlasenko7d6a7912009-07-19 04:24:23 +02001471 /* Kill any timeouts, user wants this to hurry along */
Denys Vlasenko4248c332009-06-26 23:23:16 +02001472 timeout = 0;
1473 continue;
1474 case SIGUSR2:
1475 perform_release(requested_ip, server_addr);
1476 timeout = INT_MAX;
1477 continue;
1478 case SIGTERM:
1479 bb_info_msg("Received SIGTERM");
1480 if (opt & OPT_R) /* release on quit */
1481 perform_release(requested_ip, server_addr);
1482 goto ret0;
Denis Vlasenko9cdfd142007-11-22 01:00:00 +00001483 }
1484
Denis Vlasenko739e30f2008-09-26 23:45:20 +00001485 /* Is it a packet? */
Denys Vlasenko4248c332009-06-26 23:23:16 +02001486 if (listen_mode == LISTEN_NONE || !FD_ISSET(sockfd, &rfds))
1487 continue; /* no */
Mike Frysinger7031f622006-05-08 03:20:50 +00001488
Denys Vlasenko4248c332009-06-26 23:23:16 +02001489 {
1490 int len;
1491
1492 /* A packet is ready, read it */
Mike Frysinger7031f622006-05-08 03:20:50 +00001493 if (listen_mode == LISTEN_KERNEL)
Denis Vlasenko6de89942008-05-21 07:05:06 +00001494 len = udhcp_recv_kernel_packet(&packet, sockfd);
Denis Vlasenkob76b9a42008-01-25 22:46:34 +00001495 else
Denis Vlasenko6de89942008-05-21 07:05:06 +00001496 len = udhcp_recv_raw_packet(&packet, sockfd);
Denys Vlasenko4248c332009-06-26 23:23:16 +02001497 if (len == -1) {
1498 /* Error is severe, reopen socket */
Denys Vlasenkoac906fa2009-06-17 11:54:52 +02001499 bb_info_msg("Read error: %s, reopening socket", strerror(errno));
Denis Vlasenko6de89942008-05-21 07:05:06 +00001500 sleep(discover_timeout); /* 3 seconds by default */
1501 change_listen_mode(listen_mode); /* just close and reopen */
1502 }
Denis Vlasenkob2342912008-05-21 07:02:16 +00001503 /* If this packet will turn out to be unrelated/bogus,
1504 * we will go back and wait for next one.
1505 * Be sure timeout is properly decreased. */
Denis Vlasenko19903f02008-05-21 07:03:03 +00001506 already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait;
Denis Vlasenko6de89942008-05-21 07:05:06 +00001507 if (len < 0)
1508 continue;
Denys Vlasenko4248c332009-06-26 23:23:16 +02001509 }
Mike Frysinger7031f622006-05-08 03:20:50 +00001510
Denys Vlasenko4248c332009-06-26 23:23:16 +02001511 if (packet.xid != xid) {
1512 log1("xid %x (our is %x), ignoring packet",
1513 (unsigned)packet.xid, (unsigned)xid);
1514 continue;
1515 }
Mike Frysinger7031f622006-05-08 03:20:50 +00001516
Denys Vlasenko4248c332009-06-26 23:23:16 +02001517 /* Ignore packets that aren't for us */
1518 if (packet.hlen != 6
Denys Vlasenkob3af65b2010-10-20 21:37:23 +02001519 || memcmp(packet.chaddr, client_config.client_mac, 6) != 0
Denys Vlasenko4248c332009-06-26 23:23:16 +02001520 ) {
Denys Vlasenkoac906fa2009-06-17 11:54:52 +02001521//FIXME: need to also check that last 10 bytes are zero
Denys Vlasenko4248c332009-06-26 23:23:16 +02001522 log1("chaddr does not match, ignoring packet"); // log2?
1523 continue;
1524 }
Mike Frysinger7031f622006-05-08 03:20:50 +00001525
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +01001526 message = udhcp_get_option(&packet, DHCP_MESSAGE_TYPE);
Denys Vlasenko4248c332009-06-26 23:23:16 +02001527 if (message == NULL) {
1528 bb_error_msg("no message type option, ignoring packet");
1529 continue;
1530 }
Mike Frysinger7031f622006-05-08 03:20:50 +00001531
Denys Vlasenko4248c332009-06-26 23:23:16 +02001532 switch (state) {
1533 case INIT_SELECTING:
1534 /* Must be a DHCPOFFER to one of our xid's */
1535 if (*message == DHCPOFFER) {
Denys Vlasenko2af2acf2011-10-20 14:47:41 +02001536/* What exactly is server's IP? There are several values.
1537 * Example DHCP offer captured with tchdump:
1538 *
1539 * 10.34.25.254:67 > 10.34.25.202:68 // IP header's src
1540 * BOOTP fields:
1541 * Your-IP 10.34.25.202
1542 * Server-IP 10.34.32.125 // "next server" IP
1543 * Gateway-IP 10.34.25.254 // relay's address (if DHCP relays are in use)
1544 * DHCP options:
1545 * DHCP-Message Option 53, length 1: Offer
1546 * Server-ID Option 54, length 4: 10.34.255.7 // "server ID"
1547 * Default-Gateway Option 3, length 4: 10.34.25.254 // router
1548 *
1549 * We think that real server IP (one to use in renew/release)
1550 * is one in Server-ID option. But I am not 100% sure.
Denys Vlasenkoee320c62011-10-23 18:05:58 +02001551 * IP header's src and Gateway-IP (same in this example)
Denys Vlasenko2af2acf2011-10-20 14:47:41 +02001552 * might work too.
1553 * "Next server" and router are definitely wrong ones to use, though...
1554 */
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +01001555 temp = udhcp_get_option(&packet, DHCP_SERVER_ID);
Denys Vlasenko4248c332009-06-26 23:23:16 +02001556 if (!temp) {
Denys Vlasenkoc72c1d72010-10-20 22:08:16 +02001557 bb_error_msg("no server ID, ignoring packet");
Denys Vlasenko4248c332009-06-26 23:23:16 +02001558 continue;
1559 /* still selecting - this server looks bad */
Mike Frysinger7031f622006-05-08 03:20:50 +00001560 }
Denys Vlasenko4248c332009-06-26 23:23:16 +02001561 /* it IS unaligned sometimes, don't "optimize" */
1562 move_from_unaligned32(server_addr, temp);
Denys Vlasenkob3af65b2010-10-20 21:37:23 +02001563 /*xid = packet.xid; - already is */
Denys Vlasenko4248c332009-06-26 23:23:16 +02001564 requested_ip = packet.yiaddr;
1565
1566 /* enter requesting state */
1567 state = REQUESTING;
1568 timeout = 0;
1569 packet_num = 0;
1570 already_waited_sec = 0;
1571 }
1572 continue;
Denys Vlasenko4248c332009-06-26 23:23:16 +02001573 case REQUESTING:
1574 case RENEWING:
Denys Vlasenko13ca4b12009-07-19 04:07:21 +02001575 case RENEW_REQUESTED:
Denys Vlasenko4248c332009-06-26 23:23:16 +02001576 case REBINDING:
1577 if (*message == DHCPACK) {
Denys Vlasenkodde8bdc2010-03-22 14:29:13 +01001578 temp = udhcp_get_option(&packet, DHCP_LEASE_TIME);
Denys Vlasenko4248c332009-06-26 23:23:16 +02001579 if (!temp) {
1580 bb_error_msg("no lease time with ACK, using 1 hour lease");
1581 lease_seconds = 60 * 60;
1582 } else {
1583 /* it IS unaligned sometimes, don't "optimize" */
1584 move_from_unaligned32(lease_seconds, temp);
1585 lease_seconds = ntohl(lease_seconds);
1586 lease_seconds &= 0x0fffffff; /* paranoia: must not be prone to overflows */
1587 if (lease_seconds < 10) /* and not too small */
1588 lease_seconds = 10;
1589 }
Denis Vlasenko223bc972007-11-22 00:58:49 +00001590#if ENABLE_FEATURE_UDHCPC_ARPING
Denys Vlasenko4248c332009-06-26 23:23:16 +02001591 if (opt & OPT_a) {
Denis Vlasenko739e30f2008-09-26 23:45:20 +00001592/* RFC 2131 3.1 paragraph 5:
1593 * "The client receives the DHCPACK message with configuration
1594 * parameters. The client SHOULD perform a final check on the
1595 * parameters (e.g., ARP for allocated network address), and notes
1596 * the duration of the lease specified in the DHCPACK message. At this
1597 * point, the client is configured. If the client detects that the
1598 * address is already in use (e.g., through the use of ARP),
1599 * the client MUST send a DHCPDECLINE message to the server and restarts
1600 * the configuration process..." */
Denys Vlasenko4248c332009-06-26 23:23:16 +02001601 if (!arpping(packet.yiaddr,
1602 NULL,
1603 (uint32_t) 0,
1604 client_config.client_mac,
1605 client_config.interface)
1606 ) {
1607 bb_info_msg("Offered address is in use "
1608 "(got ARP reply), declining");
1609 send_decline(xid, server_addr, packet.yiaddr);
Denis Vlasenko223bc972007-11-22 00:58:49 +00001610
Denys Vlasenko4248c332009-06-26 23:23:16 +02001611 if (state != REQUESTING)
1612 udhcp_run_script(NULL, "deconfig");
1613 change_listen_mode(LISTEN_RAW);
1614 state = INIT_SELECTING;
Denys Vlasenko9ac55962011-03-12 05:37:54 +01001615 client_config.first_secs = 0; /* make secs field count from 0 */
Denys Vlasenko4248c332009-06-26 23:23:16 +02001616 requested_ip = 0;
1617 timeout = tryagain_timeout;
1618 packet_num = 0;
1619 already_waited_sec = 0;
1620 continue; /* back to main loop */
Denis Vlasenko223bc972007-11-22 00:58:49 +00001621 }
Denys Vlasenko4248c332009-06-26 23:23:16 +02001622 }
Denis Vlasenko223bc972007-11-22 00:58:49 +00001623#endif
Denys Vlasenko4248c332009-06-26 23:23:16 +02001624 /* enter bound state */
1625 timeout = lease_seconds / 2;
1626 {
1627 struct in_addr temp_addr;
1628 temp_addr.s_addr = packet.yiaddr;
1629 bb_info_msg("Lease of %s obtained, lease time %u",
1630 inet_ntoa(temp_addr), (unsigned)lease_seconds);
1631 }
1632 requested_ip = packet.yiaddr;
Denys Vlasenko4abfc262009-07-19 04:35:16 +02001633 udhcp_run_script(&packet, state == REQUESTING ? "bound" : "renew");
Mike Frysinger7031f622006-05-08 03:20:50 +00001634
Denys Vlasenko4248c332009-06-26 23:23:16 +02001635 state = BOUND;
1636 change_listen_mode(LISTEN_NONE);
1637 if (opt & OPT_q) { /* quit after lease */
1638 if (opt & OPT_R) /* release on quit */
1639 perform_release(requested_ip, server_addr);
1640 goto ret0;
1641 }
Justin Maggardaa369e02009-08-13 01:26:17 +02001642 /* future renew failures should not exit (JM) */
1643 opt &= ~OPT_n;
Denis Vlasenko21765fa2008-06-13 20:44:05 +00001644#if BB_MMU /* NOMMU case backgrounded earlier */
Denys Vlasenko4248c332009-06-26 23:23:16 +02001645 if (!(opt & OPT_f)) {
1646 client_background();
1647 /* do not background again! */
1648 opt = ((opt & ~OPT_b) | OPT_f);
1649 }
Denis Vlasenko21765fa2008-06-13 20:44:05 +00001650#endif
Denys Vlasenko4248c332009-06-26 23:23:16 +02001651 already_waited_sec = 0;
1652 continue; /* back to main loop */
Mike Frysinger7031f622006-05-08 03:20:50 +00001653 }
Denys Vlasenko4248c332009-06-26 23:23:16 +02001654 if (*message == DHCPNAK) {
1655 /* return to init state */
1656 bb_info_msg("Received DHCP NAK");
1657 udhcp_run_script(&packet, "nak");
1658 if (state != REQUESTING)
1659 udhcp_run_script(NULL, "deconfig");
1660 change_listen_mode(LISTEN_RAW);
1661 sleep(3); /* avoid excessive network traffic */
1662 state = INIT_SELECTING;
Denys Vlasenko9ac55962011-03-12 05:37:54 +01001663 client_config.first_secs = 0; /* make secs field count from 0 */
Denys Vlasenko4248c332009-06-26 23:23:16 +02001664 requested_ip = 0;
Denis Vlasenkob539c842007-11-29 08:17:45 +00001665 timeout = 0;
Denys Vlasenko4248c332009-06-26 23:23:16 +02001666 packet_num = 0;
1667 already_waited_sec = 0;
Mike Frysinger7031f622006-05-08 03:20:50 +00001668 }
Denys Vlasenko4248c332009-06-26 23:23:16 +02001669 continue;
1670 /* case BOUND: - ignore all packets */
1671 /* case RELEASED: - ignore all packets */
Mike Frysinger7031f622006-05-08 03:20:50 +00001672 }
Denys Vlasenko4248c332009-06-26 23:23:16 +02001673 /* back to main loop */
Denis Vlasenko9cdfd142007-11-22 01:00:00 +00001674 } /* for (;;) - main loop ends */
1675
Denis Vlasenko6e6d3312007-05-03 23:39:35 +00001676 ret0:
1677 retval = 0;
1678 ret:
Denis Vlasenkob2342912008-05-21 07:02:16 +00001679 /*if (client_config.pidfile) - remove_pidfile has its own check */
Denis Vlasenko6e6d3312007-05-03 23:39:35 +00001680 remove_pidfile(client_config.pidfile);
1681 return retval;
Mike Frysinger7031f622006-05-08 03:20:50 +00001682}