1 /*
2 * Argument parser
3 * Copyright © Jan Engelhardt, 2011
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation; either version 2 of
8 * the License, or (at your option) any later version.
9 */
10 #include <ctype.h>
11 #include <errno.h>
12 #include <getopt.h>
13 #include <limits.h>
14 #include <netdb.h>
15 #include <stdbool.h>
16 #include <stdint.h>
17 #include <stdio.h>
18 #include <stdlib.h>
19 #include <string.h>
20 #include <syslog.h>
21 #include <arpa/inet.h>
22 #include <netinet/ip.h>
23 #include "xtables.h"
24 #include "xshared.h"
25 #ifndef IPTOS_NORMALSVC
26 # define IPTOS_NORMALSVC 0
27 #endif
28
29 #define XTOPT_MKPTR(cb) \
30 ((void *)((char *)(cb)->data + (cb)->entry->ptroff))
31
32 /**
33 * Simple key-value pairs for syslog levels
34 */
35 struct syslog_level {
36 char name[8];
37 uint8_t level;
38 };
39
40 struct tos_value_mask {
41 uint8_t value, mask;
42 };
43
44 static const size_t xtopt_psize[] = {
45 /*
46 * All types not listed here, and thus essentially being initialized to
47 * zero have zero on purpose.
48 */
49 [XTTYPE_UINT8] = sizeof(uint8_t),
50 [XTTYPE_UINT16] = sizeof(uint16_t),
51 [XTTYPE_UINT32] = sizeof(uint32_t),
52 [XTTYPE_UINT64] = sizeof(uint64_t),
53 [XTTYPE_UINT8RC] = sizeof(uint8_t[2]),
54 [XTTYPE_UINT16RC] = sizeof(uint16_t[2]),
55 [XTTYPE_UINT32RC] = sizeof(uint32_t[2]),
56 [XTTYPE_UINT64RC] = sizeof(uint64_t[2]),
57 [XTTYPE_DOUBLE] = sizeof(double),
58 [XTTYPE_STRING] = -1,
59 [XTTYPE_SYSLOGLEVEL] = sizeof(uint8_t),
60 [XTTYPE_HOST] = sizeof(union nf_inet_addr),
61 [XTTYPE_HOSTMASK] = sizeof(union nf_inet_addr),
62 [XTTYPE_PROTOCOL] = sizeof(uint8_t),
63 [XTTYPE_PORT] = sizeof(uint16_t),
64 [XTTYPE_PORTRC] = sizeof(uint16_t[2]),
65 [XTTYPE_PLENMASK] = sizeof(union nf_inet_addr),
66 [XTTYPE_ETHERMAC] = sizeof(uint8_t[6]),
67 };
68
69 /**
70 * Creates getopt options from the x6-style option map, and assigns each a
71 * getopt id.
72 */
73 struct option *
xtables_options_xfrm(struct option * orig_opts,struct option * oldopts,const struct xt_option_entry * entry,unsigned int * offset)74 xtables_options_xfrm(struct option *orig_opts, struct option *oldopts,
75 const struct xt_option_entry *entry, unsigned int *offset)
76 {
77 unsigned int num_orig, num_old = 0, num_new, i;
78 struct option *merge, *mp;
79
80 if (entry == NULL)
81 return oldopts;
82 for (num_orig = 0; orig_opts[num_orig].name != NULL; ++num_orig)
83 ;
84 if (oldopts != NULL)
85 for (num_old = 0; oldopts[num_old].name != NULL; ++num_old)
86 ;
87 for (num_new = 0; entry[num_new].name != NULL; ++num_new)
88 ;
89
90 /*
91 * Since @oldopts also has @orig_opts already (and does so at the
92 * start), skip these entries.
93 */
94 oldopts += num_orig;
95 num_old -= num_orig;
96
97 merge = malloc(sizeof(*mp) * (num_orig + num_old + num_new + 1));
98 if (merge == NULL)
99 return NULL;
100
101 /* Let the base options -[ADI...] have precedence over everything */
102 memcpy(merge, orig_opts, sizeof(*mp) * num_orig);
103 mp = merge + num_orig;
104
105 /* Second, the new options */
106 xt_params->option_offset += XT_OPTION_OFFSET_SCALE;
107 *offset = xt_params->option_offset;
108
109 for (i = 0; i < num_new; ++i, ++mp, ++entry) {
110 mp->name = entry->name;
111 mp->has_arg = entry->type != XTTYPE_NONE;
112 mp->flag = NULL;
113 mp->val = entry->id + *offset;
114 }
115
116 /* Third, the old options */
117 memcpy(mp, oldopts, sizeof(*mp) * num_old);
118 mp += num_old;
119 xtables_free_opts(0);
120
121 /* Clear trailing entry */
122 memset(mp, 0, sizeof(*mp));
123 return merge;
124 }
125
126 /**
127 * Give the upper limit for a certain type.
128 */
xtopt_max_by_type(enum xt_option_type type)129 static uintmax_t xtopt_max_by_type(enum xt_option_type type)
130 {
131 switch (type) {
132 case XTTYPE_UINT8:
133 case XTTYPE_UINT8RC:
134 return UINT8_MAX;
135 case XTTYPE_UINT16:
136 case XTTYPE_UINT16RC:
137 return UINT16_MAX;
138 case XTTYPE_UINT32:
139 case XTTYPE_UINT32RC:
140 return UINT32_MAX;
141 case XTTYPE_UINT64:
142 case XTTYPE_UINT64RC:
143 return UINT64_MAX;
144 default:
145 return 0;
146 }
147 }
148
149 /**
150 * Return the size of a single entity based upon a type - predominantly an
151 * XTTYPE_UINT*RC type.
152 */
xtopt_esize_by_type(enum xt_option_type type)153 static size_t xtopt_esize_by_type(enum xt_option_type type)
154 {
155 switch (type) {
156 case XTTYPE_UINT8RC:
157 return xtopt_psize[XTTYPE_UINT8];
158 case XTTYPE_UINT16RC:
159 return xtopt_psize[XTTYPE_UINT16];
160 case XTTYPE_UINT32RC:
161 return xtopt_psize[XTTYPE_UINT32];
162 case XTTYPE_UINT64RC:
163 return xtopt_psize[XTTYPE_UINT64];
164 default:
165 return xtopt_psize[type];
166 }
167 }
168
169 /**
170 * Require a simple integer.
171 */
xtopt_parse_int(struct xt_option_call * cb)172 static void xtopt_parse_int(struct xt_option_call *cb)
173 {
174 const struct xt_option_entry *entry = cb->entry;
175 uintmax_t lmin = 0, lmax = xtopt_max_by_type(entry->type);
176 uintmax_t value;
177
178 if (cb->entry->min != 0)
179 lmin = cb->entry->min;
180 if (cb->entry->max != 0)
181 lmax = cb->entry->max;
182
183 if (!xtables_strtoul(cb->arg, NULL, &value, lmin, lmax))
184 xt_params->exit_err(PARAMETER_PROBLEM,
185 "%s: bad value for option \"--%s\", "
186 "or out of range (%ju-%ju).\n",
187 cb->ext_name, entry->name, lmin, lmax);
188
189 if (entry->type == XTTYPE_UINT8) {
190 cb->val.u8 = value;
191 if (entry->flags & XTOPT_PUT)
192 *(uint8_t *)XTOPT_MKPTR(cb) = cb->val.u8;
193 } else if (entry->type == XTTYPE_UINT16) {
194 cb->val.u16 = value;
195 if (entry->flags & XTOPT_PUT)
196 *(uint16_t *)XTOPT_MKPTR(cb) = cb->val.u16;
197 } else if (entry->type == XTTYPE_UINT32) {
198 cb->val.u32 = value;
199 if (entry->flags & XTOPT_PUT)
200 *(uint32_t *)XTOPT_MKPTR(cb) = cb->val.u32;
201 } else if (entry->type == XTTYPE_UINT64) {
202 cb->val.u64 = value;
203 if (entry->flags & XTOPT_PUT)
204 *(uint64_t *)XTOPT_MKPTR(cb) = cb->val.u64;
205 }
206 }
207
208 /**
209 * Require a simple floating point number.
210 */
xtopt_parse_float(struct xt_option_call * cb)211 static void xtopt_parse_float(struct xt_option_call *cb)
212 {
213 const struct xt_option_entry *entry = cb->entry;
214 double value;
215 char *end;
216
217 value = strtod(cb->arg, &end);
218 if (end == cb->arg || *end != '\0' ||
219 (entry->min != entry->max &&
220 (value < entry->min || value > entry->max)))
221 xt_params->exit_err(PARAMETER_PROBLEM,
222 "%s: bad value for option \"--%s\", "
223 "or out of range (%u-%u).\n",
224 cb->ext_name, entry->name, entry->min, entry->max);
225
226 cb->val.dbl = value;
227 if (entry->flags & XTOPT_PUT)
228 *(double *)XTOPT_MKPTR(cb) = cb->val.dbl;
229 }
230
231 /**
232 * Copy the parsed value to the appropriate entry in cb->val.
233 */
xtopt_mint_value_to_cb(struct xt_option_call * cb,uintmax_t value)234 static void xtopt_mint_value_to_cb(struct xt_option_call *cb, uintmax_t value)
235 {
236 const struct xt_option_entry *entry = cb->entry;
237
238 if (cb->nvals >= ARRAY_SIZE(cb->val.u32_range))
239 return;
240 if (entry->type == XTTYPE_UINT8RC)
241 cb->val.u8_range[cb->nvals] = value;
242 else if (entry->type == XTTYPE_UINT16RC)
243 cb->val.u16_range[cb->nvals] = value;
244 else if (entry->type == XTTYPE_UINT32RC)
245 cb->val.u32_range[cb->nvals] = value;
246 else if (entry->type == XTTYPE_UINT64RC)
247 cb->val.u64_range[cb->nvals] = value;
248 }
249
250 /**
251 * Copy the parsed value to the data area, using appropriate type access.
252 */
xtopt_mint_value_to_ptr(struct xt_option_call * cb,void ** datap,uintmax_t value)253 static void xtopt_mint_value_to_ptr(struct xt_option_call *cb, void **datap,
254 uintmax_t value)
255 {
256 const struct xt_option_entry *entry = cb->entry;
257 void *data = *datap;
258
259 if (!(entry->flags & XTOPT_PUT))
260 return;
261 if (entry->type == XTTYPE_UINT8RC)
262 *(uint8_t *)data = value;
263 else if (entry->type == XTTYPE_UINT16RC)
264 *(uint16_t *)data = value;
265 else if (entry->type == XTTYPE_UINT32RC)
266 *(uint32_t *)data = value;
267 else if (entry->type == XTTYPE_UINT64RC)
268 *(uint64_t *)data = value;
269 data += xtopt_esize_by_type(entry->type);
270 *datap = data;
271 }
272
273 /**
274 * Multiple integer parse routine.
275 *
276 * This function is capable of parsing any number of fields. Only the first
277 * two values from the string will be put into @cb however (and as such,
278 * @cb->val.uXX_range is just that large) to cater for the few extensions that
279 * do not have a range[2] field, but {min, max}, and which cannot use
280 * XTOPT_POINTER.
281 */
xtopt_parse_mint(struct xt_option_call * cb)282 static void xtopt_parse_mint(struct xt_option_call *cb)
283 {
284 const struct xt_option_entry *entry = cb->entry;
285 const char *arg = cb->arg;
286 size_t esize = xtopt_esize_by_type(entry->type);
287 const uintmax_t lmax = xtopt_max_by_type(entry->type);
288 void *put = XTOPT_MKPTR(cb);
289 unsigned int maxiter;
290 uintmax_t value;
291 char *end = "";
292 char sep = ':';
293
294 maxiter = entry->size / esize;
295 if (maxiter == 0)
296 maxiter = ARRAY_SIZE(cb->val.u32_range);
297 if (entry->size % esize != 0)
298 xt_params->exit_err(OTHER_PROBLEM, "%s: memory block does "
299 "not have proper size\n", __func__);
300
301 cb->nvals = 0;
302 for (arg = cb->arg, end = (char *)arg; ; arg = end + 1) {
303 if (cb->nvals == maxiter)
304 xt_params->exit_err(PARAMETER_PROBLEM, "%s: Too many "
305 "components for option \"--%s\" (max: %u)\n",
306 cb->ext_name, entry->name, maxiter);
307 if (*arg == '\0' || *arg == sep) {
308 /* Default range components when field not spec'd. */
309 end = (char *)arg;
310 value = (cb->nvals == 1) ? lmax : 0;
311 } else {
312 if (!xtables_strtoul(arg, &end, &value, 0, lmax))
313 xt_params->exit_err(PARAMETER_PROBLEM,
314 "%s: bad value for option \"--%s\" near "
315 "\"%s\", or out of range (0-%ju).\n",
316 cb->ext_name, entry->name, arg, lmax);
317 if (*end != '\0' && *end != sep)
318 xt_params->exit_err(PARAMETER_PROBLEM,
319 "%s: Argument to \"--%s\" has "
320 "unexpected characters near \"%s\".\n",
321 cb->ext_name, entry->name, end);
322 }
323 xtopt_mint_value_to_cb(cb, value);
324 ++cb->nvals;
325 xtopt_mint_value_to_ptr(cb, &put, value);
326 if (*end == '\0')
327 break;
328 }
329 }
330
xtopt_parse_string(struct xt_option_call * cb)331 static void xtopt_parse_string(struct xt_option_call *cb)
332 {
333 const struct xt_option_entry *entry = cb->entry;
334 size_t z = strlen(cb->arg);
335 char *p;
336
337 if (entry->min != 0 && z < entry->min)
338 xt_params->exit_err(PARAMETER_PROBLEM,
339 "Argument must have a minimum length of "
340 "%u characters\n", entry->min);
341 if (entry->max != 0 && z > entry->max)
342 xt_params->exit_err(PARAMETER_PROBLEM,
343 "Argument must have a maximum length of "
344 "%u characters\n", entry->max);
345 if (!(entry->flags & XTOPT_PUT))
346 return;
347 if (z >= entry->size)
348 z = entry->size - 1;
349 p = XTOPT_MKPTR(cb);
350 strncpy(p, cb->arg, z);
351 p[z] = '\0';
352 }
353
354 static const struct tos_symbol_info {
355 unsigned char value;
356 const char *name;
357 } tos_symbol_names[] = {
358 {IPTOS_LOWDELAY, "Minimize-Delay"},
359 {IPTOS_THROUGHPUT, "Maximize-Throughput"},
360 {IPTOS_RELIABILITY, "Maximize-Reliability"},
361 {IPTOS_MINCOST, "Minimize-Cost"},
362 {IPTOS_NORMALSVC, "Normal-Service"},
363 {},
364 };
365
366 /*
367 * tos_parse_numeric - parse a string like "15/255"
368 *
369 * @str: input string
370 * @tvm: (value/mask) tuple
371 * @max: maximum allowed value (must be pow(2,some_int)-1)
372 */
tos_parse_numeric(const char * str,struct xt_option_call * cb,unsigned int max)373 static bool tos_parse_numeric(const char *str, struct xt_option_call *cb,
374 unsigned int max)
375 {
376 unsigned int value;
377 char *end;
378
379 xtables_strtoui(str, &end, &value, 0, max);
380 cb->val.tos_value = value;
381 cb->val.tos_mask = max;
382
383 if (*end == '/') {
384 const char *p = end + 1;
385
386 if (!xtables_strtoui(p, &end, &value, 0, max))
387 xtables_error(PARAMETER_PROBLEM, "Illegal value: \"%s\"",
388 str);
389 cb->val.tos_mask = value;
390 }
391
392 if (*end != '\0')
393 xtables_error(PARAMETER_PROBLEM, "Illegal value: \"%s\"", str);
394 return true;
395 }
396
397 /**
398 * @str: input string
399 * @tvm: (value/mask) tuple
400 * @def_mask: mask to force when a symbolic name is used
401 */
xtopt_parse_tosmask(struct xt_option_call * cb)402 static void xtopt_parse_tosmask(struct xt_option_call *cb)
403 {
404 const struct tos_symbol_info *symbol;
405 char *tmp;
406
407 if (xtables_strtoui(cb->arg, &tmp, NULL, 0, UINT8_MAX)) {
408 tos_parse_numeric(cb->arg, cb, UINT8_MAX);
409 return;
410 }
411 /*
412 * This is our way we deal with different defaults
413 * for different revisions.
414 */
415 cb->val.tos_mask = cb->entry->max;
416 for (symbol = tos_symbol_names; symbol->name != NULL; ++symbol)
417 if (strcasecmp(cb->arg, symbol->name) == 0) {
418 cb->val.tos_value = symbol->value;
419 return;
420 }
421
422 xtables_error(PARAMETER_PROBLEM, "Symbolic name \"%s\" is unknown",
423 cb->arg);
424 }
425
426 /**
427 * Validate the input for being conformant to "mark[/mask]".
428 */
xtopt_parse_markmask(struct xt_option_call * cb)429 static void xtopt_parse_markmask(struct xt_option_call *cb)
430 {
431 unsigned int mark = 0, mask = ~0U;
432 char *end;
433
434 if (!xtables_strtoui(cb->arg, &end, &mark, 0, UINT32_MAX))
435 xt_params->exit_err(PARAMETER_PROBLEM,
436 "%s: bad mark value for option \"--%s\", "
437 "or out of range.\n",
438 cb->ext_name, cb->entry->name);
439 if (*end == '/' &&
440 !xtables_strtoui(end + 1, &end, &mask, 0, UINT32_MAX))
441 xt_params->exit_err(PARAMETER_PROBLEM,
442 "%s: bad mask value for option \"--%s\", "
443 "or out of range.\n",
444 cb->ext_name, cb->entry->name);
445 if (*end != '\0')
446 xt_params->exit_err(PARAMETER_PROBLEM,
447 "%s: trailing garbage after value "
448 "for option \"--%s\".\n",
449 cb->ext_name, cb->entry->name);
450 cb->val.mark = mark;
451 cb->val.mask = mask;
452 }
453
xtopt_sysloglvl_compare(const void * a,const void * b)454 static int xtopt_sysloglvl_compare(const void *a, const void *b)
455 {
456 const char *name = a;
457 const struct syslog_level *entry = b;
458
459 return strcmp(name, entry->name);
460 }
461
xtopt_parse_sysloglevel(struct xt_option_call * cb)462 static void xtopt_parse_sysloglevel(struct xt_option_call *cb)
463 {
464 static const struct syslog_level log_names[] = { /* must be sorted */
465 {"alert", LOG_ALERT},
466 {"crit", LOG_CRIT},
467 {"debug", LOG_DEBUG},
468 {"emerg", LOG_EMERG},
469 {"error", LOG_ERR}, /* deprecated */
470 {"info", LOG_INFO},
471 {"notice", LOG_NOTICE},
472 {"panic", LOG_EMERG}, /* deprecated */
473 {"warning", LOG_WARNING},
474 };
475 const struct syslog_level *e;
476 unsigned int num = 0;
477
478 if (!xtables_strtoui(cb->arg, NULL, &num, 0, 7)) {
479 e = bsearch(cb->arg, log_names, ARRAY_SIZE(log_names),
480 sizeof(*log_names), xtopt_sysloglvl_compare);
481 if (e == NULL)
482 xt_params->exit_err(PARAMETER_PROBLEM,
483 "log level \"%s\" unknown\n", cb->arg);
484 num = e->level;
485 }
486 cb->val.syslog_level = num;
487 if (cb->entry->flags & XTOPT_PUT)
488 *(uint8_t *)XTOPT_MKPTR(cb) = num;
489 }
490
xtables_sa_host(const void * sa,unsigned int afproto)491 static void *xtables_sa_host(const void *sa, unsigned int afproto)
492 {
493 if (afproto == AF_INET6)
494 return &((struct sockaddr_in6 *)sa)->sin6_addr;
495 else if (afproto == AF_INET)
496 return &((struct sockaddr_in *)sa)->sin_addr;
497 return (void *)sa;
498 }
499
xtables_sa_hostlen(unsigned int afproto)500 static socklen_t xtables_sa_hostlen(unsigned int afproto)
501 {
502 if (afproto == AF_INET6)
503 return sizeof(struct in6_addr);
504 else if (afproto == AF_INET)
505 return sizeof(struct in_addr);
506 return 0;
507 }
508
509 /**
510 * Accepts: a hostname (DNS), or a single inetaddr - without any mask. The
511 * result is stored in @cb->val.haddr. Additionally, @cb->val.hmask and
512 * @cb->val.hlen are set for completeness to the appropriate values.
513 */
xtopt_parse_host(struct xt_option_call * cb)514 static void xtopt_parse_host(struct xt_option_call *cb)
515 {
516 struct addrinfo hints = {.ai_family = afinfo->family};
517 unsigned int adcount = 0;
518 struct addrinfo *res, *p;
519 int ret;
520
521 ret = getaddrinfo(cb->arg, NULL, &hints, &res);
522 if (ret < 0)
523 xt_params->exit_err(PARAMETER_PROBLEM,
524 "getaddrinfo: %s\n", gai_strerror(ret));
525
526 memset(&cb->val.hmask, 0xFF, sizeof(cb->val.hmask));
527 cb->val.hlen = (afinfo->family == NFPROTO_IPV4) ? 32 : 128;
528
529 for (p = res; p != NULL; p = p->ai_next) {
530 if (adcount == 0) {
531 memset(&cb->val.haddr, 0, sizeof(cb->val.haddr));
532 memcpy(&cb->val.haddr,
533 xtables_sa_host(p->ai_addr, p->ai_family),
534 xtables_sa_hostlen(p->ai_family));
535 ++adcount;
536 continue;
537 }
538 if (memcmp(&cb->val.haddr,
539 xtables_sa_host(p->ai_addr, p->ai_family),
540 xtables_sa_hostlen(p->ai_family)) != 0)
541 xt_params->exit_err(PARAMETER_PROBLEM,
542 "%s resolves to more than one address\n",
543 cb->arg);
544 }
545
546 freeaddrinfo(res);
547 if (cb->entry->flags & XTOPT_PUT)
548 /* Validation in xtables_option_metavalidate */
549 memcpy(XTOPT_MKPTR(cb), &cb->val.haddr,
550 sizeof(cb->val.haddr));
551 }
552
553 /**
554 * @name: port name, or number as a string (e.g. "http" or "80")
555 *
556 * Resolve a port name to a number. Returns the port number in integral
557 * form on success, or <0 on error. (errno will not be set.)
558 */
xtables_getportbyname(const char * name)559 static int xtables_getportbyname(const char *name)
560 {
561 struct addrinfo *res = NULL, *p;
562 int ret;
563
564 ret = getaddrinfo(NULL, name, NULL, &res);
565 if (ret < 0)
566 return -1;
567 ret = -1;
568 for (p = res; p != NULL; p = p->ai_next) {
569 if (p->ai_family == AF_INET6) {
570 ret = ((struct sockaddr_in6 *)p->ai_addr)->sin6_port;
571 break;
572 } else if (p->ai_family == AF_INET) {
573 ret = ((struct sockaddr_in *)p->ai_addr)->sin_port;
574 break;
575 }
576 }
577 freeaddrinfo(res);
578 if (ret < 0)
579 return ret;
580 return ntohs(ret);
581 }
582
583 /**
584 * Validate and parse a protocol specification (number or name) by use of
585 * /etc/protocols and put the result into @cb->val.protocol.
586 */
xtopt_parse_protocol(struct xt_option_call * cb)587 static void xtopt_parse_protocol(struct xt_option_call *cb)
588 {
589 cb->val.protocol = xtables_parse_protocol(cb->arg);
590 if (cb->entry->flags & XTOPT_PUT)
591 *(uint8_t *)XTOPT_MKPTR(cb) = cb->val.protocol;
592 }
593
594 /**
595 * Validate and parse a port specification and put the result into
596 * @cb->val.port.
597 */
xtopt_parse_port(struct xt_option_call * cb)598 static void xtopt_parse_port(struct xt_option_call *cb)
599 {
600 const struct xt_option_entry *entry = cb->entry;
601 int ret;
602
603 ret = xtables_getportbyname(cb->arg);
604 if (ret < 0)
605 xt_params->exit_err(PARAMETER_PROBLEM,
606 "Port \"%s\" does not resolve to anything.\n",
607 cb->arg);
608 if (entry->flags & XTOPT_NBO)
609 ret = htons(ret);
610 cb->val.port = ret;
611 if (entry->flags & XTOPT_PUT)
612 *(uint16_t *)XTOPT_MKPTR(cb) = cb->val.port;
613 }
614
xtopt_parse_mport(struct xt_option_call * cb)615 static void xtopt_parse_mport(struct xt_option_call *cb)
616 {
617 static const size_t esize = sizeof(uint16_t);
618 const struct xt_option_entry *entry = cb->entry;
619 char *lo_arg, *wp_arg, *arg;
620 unsigned int maxiter;
621 int value;
622
623 wp_arg = lo_arg = strdup(cb->arg);
624 if (lo_arg == NULL)
625 xt_params->exit_err(RESOURCE_PROBLEM, "strdup");
626
627 maxiter = entry->size / esize;
628 if (maxiter == 0)
629 maxiter = 2; /* ARRAY_SIZE(cb->val.port_range) */
630 if (entry->size % esize != 0)
631 xt_params->exit_err(OTHER_PROBLEM, "%s: memory block does "
632 "not have proper size\n", __func__);
633
634 cb->val.port_range[0] = 0;
635 cb->val.port_range[1] = UINT16_MAX;
636 cb->nvals = 0;
637
638 while ((arg = strsep(&wp_arg, ":")) != NULL) {
639 if (cb->nvals == maxiter)
640 xt_params->exit_err(PARAMETER_PROBLEM, "%s: Too many "
641 "components for option \"--%s\" (max: %u)\n",
642 cb->ext_name, entry->name, maxiter);
643 if (*arg == '\0') {
644 ++cb->nvals;
645 continue;
646 }
647
648 value = xtables_getportbyname(arg);
649 if (value < 0)
650 xt_params->exit_err(PARAMETER_PROBLEM,
651 "Port \"%s\" does not resolve to "
652 "anything.\n", arg);
653 if (entry->flags & XTOPT_NBO)
654 value = htons(value);
655 if (cb->nvals < ARRAY_SIZE(cb->val.port_range))
656 cb->val.port_range[cb->nvals] = value;
657 ++cb->nvals;
658 }
659
660 if (cb->nvals == 1) {
661 cb->val.port_range[1] = cb->val.port_range[0];
662 ++cb->nvals;
663 }
664 if (entry->flags & XTOPT_PUT)
665 memcpy(XTOPT_MKPTR(cb), cb->val.port_range, sizeof(uint16_t) *
666 (cb->nvals <= maxiter ? cb->nvals : maxiter));
667 free(lo_arg);
668 }
669
xtopt_parse_mask(struct xt_option_call * cb)670 static int xtopt_parse_mask(struct xt_option_call *cb)
671 {
672 struct addrinfo hints = {.ai_family = afinfo->family,
673 .ai_flags = AI_NUMERICHOST };
674 struct addrinfo *res;
675 int ret;
676
677 ret = getaddrinfo(cb->arg, NULL, &hints, &res);
678 if (ret < 0)
679 return 0;
680
681 memcpy(&cb->val.hmask, xtables_sa_host(res->ai_addr, res->ai_family),
682 xtables_sa_hostlen(res->ai_family));
683
684 switch(afinfo->family) {
685 case AF_INET:
686 cb->val.hlen = xtables_ipmask_to_cidr(&cb->val.hmask.in);
687 break;
688 case AF_INET6:
689 cb->val.hlen = xtables_ip6mask_to_cidr(&cb->val.hmask.in6);
690 break;
691 }
692
693 freeaddrinfo(res);
694 return 1;
695 }
696
697 /**
698 * Parse an integer and ensure it is within the address family's prefix length
699 * limits. The result is stored in @cb->val.hlen.
700 */
xtopt_parse_plen(struct xt_option_call * cb)701 static void xtopt_parse_plen(struct xt_option_call *cb)
702 {
703 const struct xt_option_entry *entry = cb->entry;
704 unsigned int prefix_len = 128; /* happiness is a warm gcc */
705
706 cb->val.hlen = (afinfo->family == NFPROTO_IPV4) ? 32 : 128;
707 if (!xtables_strtoui(cb->arg, NULL, &prefix_len, 0, cb->val.hlen)) {
708 /* Is this mask expressed in full format? e.g. 255.255.255.0 */
709 if (xtopt_parse_mask(cb))
710 return;
711
712 xt_params->exit_err(PARAMETER_PROBLEM,
713 "%s: bad value for option \"--%s\", "
714 "neither a valid network mask "
715 "nor valid CIDR (%u-%u).\n",
716 cb->ext_name, entry->name, 0, cb->val.hlen);
717 }
718 cb->val.hlen = prefix_len;
719 }
720
721 /**
722 * Reuse xtopt_parse_plen for testing the integer. Afterwards convert this to
723 * a bitmask, and make it available through @cb->val.hmask (hlen remains
724 * valid). If %XTOPT_PUT is used, hmask will be copied to the target area.
725 */
xtopt_parse_plenmask(struct xt_option_call * cb)726 static void xtopt_parse_plenmask(struct xt_option_call *cb)
727 {
728 const struct xt_option_entry *entry = cb->entry;
729 uint32_t *mask = cb->val.hmask.all;
730
731 xtopt_parse_plen(cb);
732
733 memset(mask, 0xFF, sizeof(union nf_inet_addr));
734 /* This shifting is AF-independent. */
735 if (cb->val.hlen == 0) {
736 mask[0] = mask[1] = mask[2] = mask[3] = 0;
737 } else if (cb->val.hlen <= 32) {
738 mask[0] <<= 32 - cb->val.hlen;
739 mask[1] = mask[2] = mask[3] = 0;
740 } else if (cb->val.hlen <= 64) {
741 mask[1] <<= 32 - (cb->val.hlen - 32);
742 mask[2] = mask[3] = 0;
743 } else if (cb->val.hlen <= 96) {
744 mask[2] <<= 32 - (cb->val.hlen - 64);
745 mask[3] = 0;
746 } else if (cb->val.hlen <= 128) {
747 mask[3] <<= 32 - (cb->val.hlen - 96);
748 }
749 mask[0] = htonl(mask[0]);
750 mask[1] = htonl(mask[1]);
751 mask[2] = htonl(mask[2]);
752 mask[3] = htonl(mask[3]);
753 if (entry->flags & XTOPT_PUT)
754 memcpy(XTOPT_MKPTR(cb), mask, sizeof(union nf_inet_addr));
755 }
756
xtopt_parse_hostmask(struct xt_option_call * cb)757 static void xtopt_parse_hostmask(struct xt_option_call *cb)
758 {
759 const char *orig_arg = cb->arg;
760 char *work, *p;
761
762 if (strchr(cb->arg, '/') == NULL) {
763 xtopt_parse_host(cb);
764 return;
765 }
766 work = strdup(orig_arg);
767 if (work == NULL)
768 xt_params->exit_err(PARAMETER_PROBLEM, "strdup");
769 p = strchr(work, '/'); /* by def this can't be NULL now */
770 *p++ = '\0';
771 /*
772 * Because xtopt_parse_host and xtopt_parse_plenmask would store
773 * different things in the same target area, XTTYPE_HOSTMASK must
774 * disallow XTOPT_PUT, which it does by forcing its absence,
775 * cf. not being listed in xtopt_psize.
776 */
777 cb->arg = work;
778 xtopt_parse_host(cb);
779 cb->arg = p;
780 xtopt_parse_plenmask(cb);
781 cb->arg = orig_arg;
782 }
783
xtopt_parse_ethermac(struct xt_option_call * cb)784 static void xtopt_parse_ethermac(struct xt_option_call *cb)
785 {
786 const char *arg = cb->arg;
787 unsigned int i;
788 char *end;
789
790 for (i = 0; i < ARRAY_SIZE(cb->val.ethermac) - 1; ++i) {
791 cb->val.ethermac[i] = strtoul(arg, &end, 16);
792 if (*end != ':' || end - arg > 2)
793 goto out;
794 arg = end + 1;
795 }
796 i = ARRAY_SIZE(cb->val.ethermac) - 1;
797 cb->val.ethermac[i] = strtoul(arg, &end, 16);
798 if (*end != '\0' || end - arg > 2)
799 goto out;
800 if (cb->entry->flags & XTOPT_PUT)
801 memcpy(XTOPT_MKPTR(cb), cb->val.ethermac,
802 sizeof(cb->val.ethermac));
803 return;
804 out:
805 xt_params->exit_err(PARAMETER_PROBLEM, "ether");
806 }
807
808 static void (*const xtopt_subparse[])(struct xt_option_call *) = {
809 [XTTYPE_UINT8] = xtopt_parse_int,
810 [XTTYPE_UINT16] = xtopt_parse_int,
811 [XTTYPE_UINT32] = xtopt_parse_int,
812 [XTTYPE_UINT64] = xtopt_parse_int,
813 [XTTYPE_UINT8RC] = xtopt_parse_mint,
814 [XTTYPE_UINT16RC] = xtopt_parse_mint,
815 [XTTYPE_UINT32RC] = xtopt_parse_mint,
816 [XTTYPE_UINT64RC] = xtopt_parse_mint,
817 [XTTYPE_DOUBLE] = xtopt_parse_float,
818 [XTTYPE_STRING] = xtopt_parse_string,
819 [XTTYPE_TOSMASK] = xtopt_parse_tosmask,
820 [XTTYPE_MARKMASK32] = xtopt_parse_markmask,
821 [XTTYPE_SYSLOGLEVEL] = xtopt_parse_sysloglevel,
822 [XTTYPE_HOST] = xtopt_parse_host,
823 [XTTYPE_HOSTMASK] = xtopt_parse_hostmask,
824 [XTTYPE_PROTOCOL] = xtopt_parse_protocol,
825 [XTTYPE_PORT] = xtopt_parse_port,
826 [XTTYPE_PORTRC] = xtopt_parse_mport,
827 [XTTYPE_PLEN] = xtopt_parse_plen,
828 [XTTYPE_PLENMASK] = xtopt_parse_plenmask,
829 [XTTYPE_ETHERMAC] = xtopt_parse_ethermac,
830 };
831
832 /**
833 * The master option parsing routine. May be used for the ".x6_parse"
834 * function pointer in extensions if fully automatic parsing is desired.
835 * It may be also called manually from a custom x6_parse function.
836 */
xtables_option_parse(struct xt_option_call * cb)837 void xtables_option_parse(struct xt_option_call *cb)
838 {
839 const struct xt_option_entry *entry = cb->entry;
840 unsigned int eflag = 1 << cb->entry->id;
841
842 /*
843 * With {.id = P_FOO, .excl = P_FOO} we can have simple double-use
844 * prevention. Though it turned out that this is too much typing (most
845 * of the options are one-time use only), so now we also have
846 * %XTOPT_MULTI.
847 */
848 if ((!(entry->flags & XTOPT_MULTI) || (entry->excl & eflag)) &&
849 cb->xflags & eflag)
850 xt_params->exit_err(PARAMETER_PROBLEM,
851 "%s: option \"--%s\" can only be used once.\n",
852 cb->ext_name, cb->entry->name);
853 if (cb->invert && !(entry->flags & XTOPT_INVERT))
854 xt_params->exit_err(PARAMETER_PROBLEM,
855 "%s: option \"--%s\" cannot be inverted.\n",
856 cb->ext_name, entry->name);
857 if (entry->type != XTTYPE_NONE && optarg == NULL)
858 xt_params->exit_err(PARAMETER_PROBLEM,
859 "%s: option \"--%s\" requires an argument.\n",
860 cb->ext_name, entry->name);
861 /*
862 * Fill in fallback value for "nvals", in case an extension (as it
863 * happened with libxt_conntrack.2) tries to read it, despite not using
864 * a *RC option type.
865 */
866 cb->nvals = 1;
867 if (entry->type <= ARRAY_SIZE(xtopt_subparse) &&
868 xtopt_subparse[entry->type] != NULL)
869 xtopt_subparse[entry->type](cb);
870 /* Exclusion with other flags tested later in finalize. */
871 cb->xflags |= 1 << entry->id;
872 }
873
874 /**
875 * Verifies that an extension's option map descriptor is valid, and ought to
876 * be called right after the extension has been loaded, and before option
877 * merging/xfrm.
878 */
xtables_option_metavalidate(const char * name,const struct xt_option_entry * entry)879 void xtables_option_metavalidate(const char *name,
880 const struct xt_option_entry *entry)
881 {
882 for (; entry->name != NULL; ++entry) {
883 if (entry->id >= CHAR_BIT * sizeof(unsigned int) ||
884 entry->id >= XT_OPTION_OFFSET_SCALE)
885 xt_params->exit_err(OTHER_PROBLEM,
886 "Extension %s uses invalid ID %u\n",
887 name, entry->id);
888 if (!(entry->flags & XTOPT_PUT)) {
889 if (entry->ptroff != 0)
890 xt_params->exit_err(OTHER_PROBLEM,
891 "%s: ptroff for \"--%s\" is non-"
892 "zero but no XTOPT_PUT is specified. "
893 "Oversight?", name, entry->name);
894 continue;
895 }
896 if (entry->type >= ARRAY_SIZE(xtopt_psize) ||
897 xtopt_psize[entry->type] == 0)
898 xt_params->exit_err(OTHER_PROBLEM,
899 "%s: entry type of option \"--%s\" cannot be "
900 "combined with XTOPT_PUT\n",
901 name, entry->name);
902 if (xtopt_psize[entry->type] != -1 &&
903 xtopt_psize[entry->type] != entry->size)
904 xt_params->exit_err(OTHER_PROBLEM,
905 "%s: option \"--%s\" points to a memory block "
906 "of wrong size (expected %zu, got %zu)\n",
907 name, entry->name,
908 xtopt_psize[entry->type], entry->size);
909 }
910 }
911
912 /**
913 * Find an option entry by its id.
914 */
915 static const struct xt_option_entry *
xtables_option_lookup(const struct xt_option_entry * entry,unsigned int id)916 xtables_option_lookup(const struct xt_option_entry *entry, unsigned int id)
917 {
918 for (; entry->name != NULL; ++entry)
919 if (entry->id == id)
920 return entry;
921 return NULL;
922 }
923
924 /**
925 * @c: getopt id (i.e. with offset)
926 * @fw: struct ipt_entry or ip6t_entry
927 *
928 * Dispatch arguments to the appropriate parse function, based upon the
929 * extension's choice of API.
930 */
xtables_option_tpcall(unsigned int c,char ** argv,bool invert,struct xtables_target * t,void * fw)931 void xtables_option_tpcall(unsigned int c, char **argv, bool invert,
932 struct xtables_target *t, void *fw)
933 {
934 struct xt_option_call cb;
935
936 if (t->x6_parse == NULL) {
937 if (t->parse != NULL)
938 t->parse(c - t->option_offset, argv, invert,
939 &t->tflags, fw, &t->t);
940 return;
941 }
942
943 c -= t->option_offset;
944 cb.entry = xtables_option_lookup(t->x6_options, c);
945 if (cb.entry == NULL)
946 xtables_error(OTHER_PROBLEM,
947 "Extension does not know id %u\n", c);
948 cb.arg = optarg;
949 cb.invert = invert;
950 cb.ext_name = t->name;
951 cb.data = t->t->data;
952 cb.xflags = t->tflags;
953 cb.target = &t->t;
954 cb.xt_entry = fw;
955 cb.udata = t->udata;
956 t->x6_parse(&cb);
957 t->tflags = cb.xflags;
958 }
959
960 /**
961 * @c: getopt id (i.e. with offset)
962 * @fw: struct ipt_entry or ip6t_entry
963 *
964 * Dispatch arguments to the appropriate parse function, based upon the
965 * extension's choice of API.
966 */
xtables_option_mpcall(unsigned int c,char ** argv,bool invert,struct xtables_match * m,void * fw)967 void xtables_option_mpcall(unsigned int c, char **argv, bool invert,
968 struct xtables_match *m, void *fw)
969 {
970 struct xt_option_call cb;
971
972 if (m->x6_parse == NULL) {
973 if (m->parse != NULL)
974 m->parse(c - m->option_offset, argv, invert,
975 &m->mflags, fw, &m->m);
976 return;
977 }
978
979 c -= m->option_offset;
980 cb.entry = xtables_option_lookup(m->x6_options, c);
981 if (cb.entry == NULL)
982 xtables_error(OTHER_PROBLEM,
983 "Extension does not know id %u\n", c);
984 cb.arg = optarg;
985 cb.invert = invert;
986 cb.ext_name = m->name;
987 cb.data = m->m->data;
988 cb.xflags = m->mflags;
989 cb.match = &m->m;
990 cb.xt_entry = fw;
991 cb.udata = m->udata;
992 m->x6_parse(&cb);
993 m->mflags = cb.xflags;
994 }
995
996 /**
997 * @name: name of extension
998 * @entry: current option (from all ext's entries) being validated
999 * @xflags: flags the extension has collected
1000 * @i: conflicting option (id) to test for
1001 */
1002 static void
xtables_option_fcheck2(const char * name,const struct xt_option_entry * entry,const struct xt_option_entry * other,unsigned int xflags)1003 xtables_option_fcheck2(const char *name, const struct xt_option_entry *entry,
1004 const struct xt_option_entry *other,
1005 unsigned int xflags)
1006 {
1007 unsigned int ef = 1 << entry->id, of = 1 << other->id;
1008
1009 if (entry->also & of && !(xflags & of))
1010 xt_params->exit_err(PARAMETER_PROBLEM,
1011 "%s: option \"--%s\" also requires \"--%s\".\n",
1012 name, entry->name, other->name);
1013
1014 if (!(entry->excl & of))
1015 /* Use of entry does not collide with other option, good. */
1016 return;
1017 if ((xflags & (ef | of)) != (ef | of))
1018 /* Conflicting options were not used. */
1019 return;
1020
1021 xt_params->exit_err(PARAMETER_PROBLEM,
1022 "%s: option \"--%s\" cannot be used together with \"--%s\".\n",
1023 name, entry->name, other->name);
1024 }
1025
1026 /**
1027 * @name: name of extension
1028 * @xflags: accumulated flags
1029 * @entry: extension's option table
1030 *
1031 * Check that all option constraints have been met. This effectively replaces
1032 * ->final_check of the older API.
1033 */
xtables_options_fcheck(const char * name,unsigned int xflags,const struct xt_option_entry * table)1034 void xtables_options_fcheck(const char *name, unsigned int xflags,
1035 const struct xt_option_entry *table)
1036 {
1037 const struct xt_option_entry *entry, *other;
1038 unsigned int i;
1039
1040 for (entry = table; entry->name != NULL; ++entry) {
1041 if (entry->flags & XTOPT_MAND &&
1042 !(xflags & (1 << entry->id)))
1043 xt_params->exit_err(PARAMETER_PROBLEM,
1044 "%s: option \"--%s\" must be specified\n",
1045 name, entry->name);
1046 if (!(xflags & (1 << entry->id)))
1047 /* Not required, not specified, thus skip. */
1048 continue;
1049
1050 for (i = 0; i < CHAR_BIT * sizeof(entry->id); ++i) {
1051 if (entry->id == i)
1052 /*
1053 * Avoid conflict with self. Multi-use check
1054 * was done earlier in xtables_option_parse.
1055 */
1056 continue;
1057 other = xtables_option_lookup(table, i);
1058 if (other == NULL)
1059 continue;
1060 xtables_option_fcheck2(name, entry, other, xflags);
1061 }
1062 }
1063 }
1064
1065 /**
1066 * Dispatch arguments to the appropriate final_check function, based upon the
1067 * extension's choice of API.
1068 */
xtables_option_tfcall(struct xtables_target * t)1069 void xtables_option_tfcall(struct xtables_target *t)
1070 {
1071 if (t->x6_fcheck != NULL) {
1072 struct xt_fcheck_call cb;
1073
1074 cb.ext_name = t->name;
1075 cb.data = t->t->data;
1076 cb.xflags = t->tflags;
1077 cb.udata = t->udata;
1078 t->x6_fcheck(&cb);
1079 } else if (t->final_check != NULL) {
1080 t->final_check(t->tflags);
1081 }
1082 if (t->x6_options != NULL)
1083 xtables_options_fcheck(t->name, t->tflags, t->x6_options);
1084 }
1085
1086 /**
1087 * Dispatch arguments to the appropriate final_check function, based upon the
1088 * extension's choice of API.
1089 */
xtables_option_mfcall(struct xtables_match * m)1090 void xtables_option_mfcall(struct xtables_match *m)
1091 {
1092 if (m->x6_fcheck != NULL) {
1093 struct xt_fcheck_call cb;
1094
1095 cb.ext_name = m->name;
1096 cb.data = m->m->data;
1097 cb.xflags = m->mflags;
1098 cb.udata = m->udata;
1099 m->x6_fcheck(&cb);
1100 } else if (m->final_check != NULL) {
1101 m->final_check(m->mflags);
1102 }
1103 if (m->x6_options != NULL)
1104 xtables_options_fcheck(m->name, m->mflags, m->x6_options);
1105 }
1106
xtables_lmap_init(const char * file)1107 struct xtables_lmap *xtables_lmap_init(const char *file)
1108 {
1109 struct xtables_lmap *lmap_head = NULL, *lmap_prev = NULL, *lmap_this;
1110 char buf[512];
1111 FILE *fp;
1112 char *cur, *nxt;
1113 int id;
1114
1115 fp = fopen(file, "re");
1116 if (fp == NULL)
1117 return NULL;
1118
1119 while (fgets(buf, sizeof(buf), fp) != NULL) {
1120 cur = buf;
1121 while (isspace(*cur))
1122 ++cur;
1123 if (*cur == '#' || *cur == '\n' || *cur == '\0')
1124 continue;
1125
1126 /* iproute2 allows hex and dec format */
1127 errno = 0;
1128 id = strtoul(cur, &nxt, strncmp(cur, "0x", 2) == 0 ? 16 : 10);
1129 if (nxt == cur || errno != 0)
1130 continue;
1131
1132 /* same boundaries as in iproute2 */
1133 if (id < 0 || id > 255)
1134 continue;
1135 cur = nxt;
1136
1137 if (!isspace(*cur))
1138 continue;
1139 while (isspace(*cur))
1140 ++cur;
1141 if (*cur == '#' || *cur == '\n' || *cur == '\0')
1142 continue;
1143 nxt = cur;
1144 while (*nxt != '\0' && !isspace(*nxt))
1145 ++nxt;
1146 if (nxt == cur)
1147 continue;
1148 *nxt = '\0';
1149
1150 /* found valid data */
1151 lmap_this = malloc(sizeof(*lmap_this));
1152 if (lmap_this == NULL) {
1153 perror("malloc");
1154 goto out;
1155 }
1156 lmap_this->id = id;
1157 lmap_this->name = strdup(cur);
1158 if (lmap_this->name == NULL) {
1159 free(lmap_this);
1160 goto out;
1161 }
1162 lmap_this->next = NULL;
1163
1164 if (lmap_prev != NULL)
1165 lmap_prev->next = lmap_this;
1166 else
1167 lmap_head = lmap_this;
1168 lmap_prev = lmap_this;
1169 }
1170
1171 fclose(fp);
1172 return lmap_head;
1173 out:
1174 fclose(fp);
1175 xtables_lmap_free(lmap_head);
1176 return NULL;
1177 }
1178
xtables_lmap_free(struct xtables_lmap * head)1179 void xtables_lmap_free(struct xtables_lmap *head)
1180 {
1181 struct xtables_lmap *next;
1182
1183 for (; head != NULL; head = next) {
1184 next = head->next;
1185 free(head->name);
1186 free(head);
1187 }
1188 }
1189
xtables_lmap_name2id(const struct xtables_lmap * head,const char * name)1190 int xtables_lmap_name2id(const struct xtables_lmap *head, const char *name)
1191 {
1192 for (; head != NULL; head = head->next)
1193 if (strcmp(head->name, name) == 0)
1194 return head->id;
1195 return -1;
1196 }
1197
xtables_lmap_id2name(const struct xtables_lmap * head,int id)1198 const char *xtables_lmap_id2name(const struct xtables_lmap *head, int id)
1199 {
1200 for (; head != NULL; head = head->next)
1201 if (head->id == id)
1202 return head->name;
1203 return NULL;
1204 }
1205