libnftnl  1.2.5
object.c
1 /*
2  * (C) 2012-2016 by Pablo Neira Ayuso <pablo@netfilter.org>
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published
6  * by the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  */
9 #include "internal.h"
10 
11 #include <time.h>
12 #include <endian.h>
13 #include <stdint.h>
14 #include <limits.h>
15 #include <stdlib.h>
16 #include <string.h>
17 #include <netinet/in.h>
18 #include <errno.h>
19 
20 #include <libmnl/libmnl.h>
21 #include <linux/netfilter/nfnetlink.h>
22 #include <linux/netfilter/nf_tables.h>
23 
24 #include <libnftnl/object.h>
25 #include "obj.h"
26 
27 static struct obj_ops *obj_ops[__NFT_OBJECT_MAX] = {
28  [NFT_OBJECT_COUNTER] = &obj_ops_counter,
29  [NFT_OBJECT_QUOTA] = &obj_ops_quota,
30  [NFT_OBJECT_CT_HELPER] = &obj_ops_ct_helper,
31  [NFT_OBJECT_LIMIT] = &obj_ops_limit,
32  [NFT_OBJECT_TUNNEL] = &obj_ops_tunnel,
33  [NFT_OBJECT_CT_TIMEOUT] = &obj_ops_ct_timeout,
34  [NFT_OBJECT_SECMARK] = &obj_ops_secmark,
35  [NFT_OBJECT_CT_EXPECT] = &obj_ops_ct_expect,
36  [NFT_OBJECT_SYNPROXY] = &obj_ops_synproxy,
37 };
38 
39 static struct obj_ops *nftnl_obj_ops_lookup(uint32_t type)
40 {
41  if (type > NFT_OBJECT_MAX)
42  return NULL;
43 
44  return obj_ops[type];
45 }
46 
47 EXPORT_SYMBOL(nftnl_obj_alloc);
48 struct nftnl_obj *nftnl_obj_alloc(void)
49 {
50  return calloc(1, sizeof(struct nftnl_obj));
51 }
52 
53 EXPORT_SYMBOL(nftnl_obj_free);
54 void nftnl_obj_free(const struct nftnl_obj *obj)
55 {
56  if (obj->flags & (1 << NFTNL_OBJ_TABLE))
57  xfree(obj->table);
58  if (obj->flags & (1 << NFTNL_OBJ_NAME))
59  xfree(obj->name);
60  if (obj->flags & (1 << NFTNL_OBJ_USERDATA))
61  xfree(obj->user.data);
62 
63  xfree(obj);
64 }
65 
66 EXPORT_SYMBOL(nftnl_obj_is_set);
67 bool nftnl_obj_is_set(const struct nftnl_obj *obj, uint16_t attr)
68 {
69  return obj->flags & (1 << attr);
70 }
71 
72 static uint32_t nftnl_obj_validate[NFTNL_OBJ_MAX + 1] = {
73  [NFTNL_OBJ_FAMILY] = sizeof(uint32_t),
74  [NFTNL_OBJ_USE] = sizeof(uint32_t),
75  [NFTNL_OBJ_HANDLE] = sizeof(uint64_t),
76 };
77 
78 EXPORT_SYMBOL(nftnl_obj_set_data);
79 void nftnl_obj_set_data(struct nftnl_obj *obj, uint16_t attr,
80  const void *data, uint32_t data_len)
81 {
82  if (attr < NFTNL_OBJ_MAX)
83  nftnl_assert_validate(data, nftnl_obj_validate, attr, data_len);
84 
85  switch (attr) {
86  case NFTNL_OBJ_TABLE:
87  xfree(obj->table);
88  obj->table = strdup(data);
89  break;
90  case NFTNL_OBJ_NAME:
91  xfree(obj->name);
92  obj->name = strdup(data);
93  break;
94  case NFTNL_OBJ_TYPE:
95  obj->ops = nftnl_obj_ops_lookup(*((uint32_t *)data));
96  if (!obj->ops)
97  return;
98  break;
99  case NFTNL_OBJ_FAMILY:
100  memcpy(&obj->family, data, sizeof(obj->family));
101  break;
102  case NFTNL_OBJ_USE:
103  memcpy(&obj->use, data, sizeof(obj->use));
104  break;
105  case NFTNL_OBJ_HANDLE:
106  memcpy(&obj->handle, data, sizeof(obj->handle));
107  break;
108  case NFTNL_OBJ_USERDATA:
109  if (obj->flags & (1 << NFTNL_OBJ_USERDATA))
110  xfree(obj->user.data);
111 
112  obj->user.data = malloc(data_len);
113  if (!obj->user.data)
114  return;
115  memcpy(obj->user.data, data, data_len);
116  obj->user.len = data_len;
117  break;
118  default:
119  if (obj->ops)
120  obj->ops->set(obj, attr, data, data_len);
121  break;
122  }
123  obj->flags |= (1 << attr);
124 }
125 
126 void nftnl_obj_set(struct nftnl_obj *obj, uint16_t attr, const void *data) __visible;
127 void nftnl_obj_set(struct nftnl_obj *obj, uint16_t attr, const void *data)
128 {
129  nftnl_obj_set_data(obj, attr, data, nftnl_obj_validate[attr]);
130 }
131 
132 EXPORT_SYMBOL(nftnl_obj_set_u8);
133 void nftnl_obj_set_u8(struct nftnl_obj *obj, uint16_t attr, uint8_t val)
134 {
135  nftnl_obj_set_data(obj, attr, &val, sizeof(uint8_t));
136 }
137 
138 EXPORT_SYMBOL(nftnl_obj_set_u16);
139 void nftnl_obj_set_u16(struct nftnl_obj *obj, uint16_t attr, uint16_t val)
140 {
141  nftnl_obj_set_data(obj, attr, &val, sizeof(uint16_t));
142 }
143 
144 EXPORT_SYMBOL(nftnl_obj_set_u32);
145 void nftnl_obj_set_u32(struct nftnl_obj *obj, uint16_t attr, uint32_t val)
146 {
147  nftnl_obj_set_data(obj, attr, &val, sizeof(uint32_t));
148 }
149 
150 EXPORT_SYMBOL(nftnl_obj_set_u64);
151 void nftnl_obj_set_u64(struct nftnl_obj *obj, uint16_t attr, uint64_t val)
152 {
153  nftnl_obj_set_data(obj, attr, &val, sizeof(uint64_t));
154 }
155 
156 EXPORT_SYMBOL(nftnl_obj_set_str);
157 void nftnl_obj_set_str(struct nftnl_obj *obj, uint16_t attr, const char *str)
158 {
159  nftnl_obj_set_data(obj, attr, str, 0);
160 }
161 
162 EXPORT_SYMBOL(nftnl_obj_get_data);
163 const void *nftnl_obj_get_data(struct nftnl_obj *obj, uint16_t attr,
164  uint32_t *data_len)
165 {
166  if (!(obj->flags & (1 << attr)))
167  return NULL;
168 
169  switch(attr) {
170  case NFTNL_OBJ_TABLE:
171  return obj->table;
172  case NFTNL_OBJ_NAME:
173  return obj->name;
174  case NFTNL_OBJ_TYPE:
175  if (!obj->ops)
176  return NULL;
177 
178  *data_len = sizeof(uint32_t);
179  return &obj->ops->type;
180  case NFTNL_OBJ_FAMILY:
181  *data_len = sizeof(uint32_t);
182  return &obj->family;
183  case NFTNL_OBJ_USE:
184  *data_len = sizeof(uint32_t);
185  return &obj->use;
186  case NFTNL_OBJ_HANDLE:
187  *data_len = sizeof(uint64_t);
188  return &obj->handle;
189  case NFTNL_OBJ_USERDATA:
190  *data_len = obj->user.len;
191  return obj->user.data;
192  default:
193  if (obj->ops)
194  return obj->ops->get(obj, attr, data_len);
195  break;
196  }
197  return NULL;
198 }
199 
200 EXPORT_SYMBOL(nftnl_obj_get);
201 const void *nftnl_obj_get(struct nftnl_obj *obj, uint16_t attr)
202 {
203  uint32_t data_len;
204  return nftnl_obj_get_data(obj, attr, &data_len);
205 }
206 
207 EXPORT_SYMBOL(nftnl_obj_get_u8);
208 uint8_t nftnl_obj_get_u8(struct nftnl_obj *obj, uint16_t attr)
209 {
210  const void *ret = nftnl_obj_get(obj, attr);
211  return ret == NULL ? 0 : *((uint8_t *)ret);
212 }
213 
214 EXPORT_SYMBOL(nftnl_obj_get_u16);
215 uint16_t nftnl_obj_get_u16(struct nftnl_obj *obj, uint16_t attr)
216 {
217  const void *ret = nftnl_obj_get(obj, attr);
218  return ret == NULL ? 0 : *((uint16_t *)ret);
219 }
220 
221 EXPORT_SYMBOL(nftnl_obj_get_u32);
222 uint32_t nftnl_obj_get_u32(struct nftnl_obj *obj, uint16_t attr)
223 {
224  const void *ret = nftnl_obj_get(obj, attr);
225  return ret == NULL ? 0 : *((uint32_t *)ret);
226 }
227 
228 EXPORT_SYMBOL(nftnl_obj_get_u64);
229 uint64_t nftnl_obj_get_u64(struct nftnl_obj *obj, uint16_t attr)
230 {
231  const void *ret = nftnl_obj_get(obj, attr);
232  return ret == NULL ? 0 : *((uint64_t *)ret);
233 }
234 
235 EXPORT_SYMBOL(nftnl_obj_get_str);
236 const char *nftnl_obj_get_str(struct nftnl_obj *obj, uint16_t attr)
237 {
238  return nftnl_obj_get(obj, attr);
239 }
240 
241 EXPORT_SYMBOL(nftnl_obj_nlmsg_build_payload);
242 void nftnl_obj_nlmsg_build_payload(struct nlmsghdr *nlh,
243  const struct nftnl_obj *obj)
244 {
245  if (obj->flags & (1 << NFTNL_OBJ_TABLE))
246  mnl_attr_put_strz(nlh, NFTA_OBJ_TABLE, obj->table);
247  if (obj->flags & (1 << NFTNL_OBJ_NAME))
248  mnl_attr_put_strz(nlh, NFTA_OBJ_NAME, obj->name);
249  if (obj->flags & (1 << NFTNL_OBJ_TYPE))
250  mnl_attr_put_u32(nlh, NFTA_OBJ_TYPE, htonl(obj->ops->type));
251  if (obj->flags & (1 << NFTNL_OBJ_HANDLE))
252  mnl_attr_put_u64(nlh, NFTA_OBJ_HANDLE, htobe64(obj->handle));
253  if (obj->flags & (1 << NFTNL_OBJ_USERDATA))
254  mnl_attr_put(nlh, NFTA_OBJ_USERDATA, obj->user.len, obj->user.data);
255  if (obj->ops) {
256  struct nlattr *nest = mnl_attr_nest_start(nlh, NFTA_OBJ_DATA);
257 
258  obj->ops->build(nlh, obj);
259  mnl_attr_nest_end(nlh, nest);
260  }
261 }
262 
263 static int nftnl_obj_parse_attr_cb(const struct nlattr *attr, void *data)
264 {
265  const struct nlattr **tb = data;
266  int type = mnl_attr_get_type(attr);
267 
268  if (mnl_attr_type_valid(attr, NFTA_OBJ_MAX) < 0)
269  return MNL_CB_OK;
270 
271  switch(type) {
272  case NFTA_OBJ_TABLE:
273  case NFTA_OBJ_NAME:
274  if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0)
275  abi_breakage();
276  break;
277  case NFTA_OBJ_HANDLE:
278  if (mnl_attr_validate(attr, MNL_TYPE_U64) < 0)
279  abi_breakage();
280  break;
281  case NFTA_OBJ_DATA:
282  if (mnl_attr_validate(attr, MNL_TYPE_NESTED) < 0)
283  abi_breakage();
284  break;
285  case NFTA_OBJ_USE:
286  if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
287  abi_breakage();
288  break;
289  case NFTA_OBJ_USERDATA:
290  if (mnl_attr_validate(attr, MNL_TYPE_BINARY) < 0)
291  abi_breakage();
292  break;
293  }
294 
295  tb[type] = attr;
296  return MNL_CB_OK;
297 }
298 
299 EXPORT_SYMBOL(nftnl_obj_nlmsg_parse);
300 int nftnl_obj_nlmsg_parse(const struct nlmsghdr *nlh, struct nftnl_obj *obj)
301 {
302  struct nfgenmsg *nfg = mnl_nlmsg_get_payload(nlh);
303  struct nlattr *tb[NFTA_OBJ_MAX + 1] = {};
304  int err;
305 
306  if (mnl_attr_parse(nlh, sizeof(*nfg), nftnl_obj_parse_attr_cb, tb) < 0)
307  return -1;
308 
309  if (tb[NFTA_OBJ_TABLE]) {
310  obj->table = strdup(mnl_attr_get_str(tb[NFTA_OBJ_TABLE]));
311  obj->flags |= (1 << NFTNL_OBJ_TABLE);
312  }
313  if (tb[NFTA_OBJ_NAME]) {
314  obj->name = strdup(mnl_attr_get_str(tb[NFTA_OBJ_NAME]));
315  obj->flags |= (1 << NFTNL_OBJ_NAME);
316  }
317  if (tb[NFTA_OBJ_TYPE]) {
318  uint32_t type = ntohl(mnl_attr_get_u32(tb[NFTA_OBJ_TYPE]));
319 
320  obj->ops = nftnl_obj_ops_lookup(type);
321  if (obj->ops)
322  obj->flags |= (1 << NFTNL_OBJ_TYPE);
323  }
324  if (tb[NFTA_OBJ_DATA]) {
325  if (obj->ops) {
326  err = obj->ops->parse(obj, tb[NFTA_OBJ_DATA]);
327  if (err < 0)
328  return err;
329  }
330  }
331  if (tb[NFTA_OBJ_USE]) {
332  obj->use = ntohl(mnl_attr_get_u32(tb[NFTA_OBJ_USE]));
333  obj->flags |= (1 << NFTNL_OBJ_USE);
334  }
335  if (tb[NFTA_OBJ_HANDLE]) {
336  obj->handle = be64toh(mnl_attr_get_u64(tb[NFTA_OBJ_HANDLE]));
337  obj->flags |= (1 << NFTNL_OBJ_HANDLE);
338  }
339  if (tb[NFTA_OBJ_USERDATA]) {
340  nftnl_obj_set_data(obj, NFTNL_OBJ_USERDATA,
341  mnl_attr_get_payload(tb[NFTA_OBJ_USERDATA]),
342  mnl_attr_get_payload_len(tb[NFTA_OBJ_USERDATA]));
343  }
344 
345  obj->family = nfg->nfgen_family;
346  obj->flags |= (1 << NFTNL_OBJ_FAMILY);
347 
348  return 0;
349 }
350 
351 static int nftnl_obj_do_parse(struct nftnl_obj *obj, enum nftnl_parse_type type,
352  const void *data, struct nftnl_parse_err *err,
353  enum nftnl_parse_input input)
354 {
355  struct nftnl_parse_err perr = {};
356  int ret;
357 
358  switch (type) {
359  case NFTNL_PARSE_JSON:
360  case NFTNL_PARSE_XML:
361  default:
362  ret = -1;
363  errno = EOPNOTSUPP;
364  break;
365  }
366 
367  if (err != NULL)
368  *err = perr;
369 
370  return ret;
371 }
372 
373 EXPORT_SYMBOL(nftnl_obj_parse);
374 int nftnl_obj_parse(struct nftnl_obj *obj, enum nftnl_parse_type type,
375  const char *data, struct nftnl_parse_err *err)
376 {
377  return nftnl_obj_do_parse(obj, type, data, err, NFTNL_PARSE_BUFFER);
378 }
379 
380 EXPORT_SYMBOL(nftnl_obj_parse_file);
381 int nftnl_obj_parse_file(struct nftnl_obj *obj, enum nftnl_parse_type type,
382  FILE *fp, struct nftnl_parse_err *err)
383 {
384  return nftnl_obj_do_parse(obj, type, fp, err, NFTNL_PARSE_FILE);
385 }
386 
387 static int nftnl_obj_snprintf_dflt(char *buf, size_t remain,
388  const struct nftnl_obj *obj,
389  uint32_t type, uint32_t flags)
390 {
391  const char *name = obj->ops ? obj->ops->name : "(unknown)";
392  int ret, offset = 0;
393 
394  ret = snprintf(buf, remain, "table %s name %s use %u [ %s ",
395  obj->table, obj->name, obj->use, name);
396  SNPRINTF_BUFFER_SIZE(ret, remain, offset);
397 
398  if (obj->ops) {
399  ret = obj->ops->output(buf + offset, remain, flags, obj);
400  SNPRINTF_BUFFER_SIZE(ret, remain, offset);
401  }
402  ret = snprintf(buf + offset, remain, "]");
403  SNPRINTF_BUFFER_SIZE(ret, remain, offset);
404 
405  return offset;
406 }
407 
408 static int nftnl_obj_cmd_snprintf(char *buf, size_t remain,
409  const struct nftnl_obj *obj, uint32_t cmd,
410  uint32_t type, uint32_t flags)
411 {
412  int ret, offset = 0;
413 
414  if (type != NFTNL_OUTPUT_DEFAULT)
415  return -1;
416 
417  ret = nftnl_obj_snprintf_dflt(buf + offset, remain, obj, type, flags);
418  SNPRINTF_BUFFER_SIZE(ret, remain, offset);
419  return offset;
420 }
421 
422 EXPORT_SYMBOL(nftnl_obj_snprintf);
423 int nftnl_obj_snprintf(char *buf, size_t size, const struct nftnl_obj *obj,
424  uint32_t type, uint32_t flags)
425 {
426  if (size)
427  buf[0] = '\0';
428 
429  return nftnl_obj_cmd_snprintf(buf, size, obj, nftnl_flag2cmd(flags),
430  type, flags);
431 }
432 
433 static int nftnl_obj_do_snprintf(char *buf, size_t size, const void *obj,
434  uint32_t cmd, uint32_t type, uint32_t flags)
435 {
436  return nftnl_obj_snprintf(buf, size, obj, type, flags);
437 }
438 
439 EXPORT_SYMBOL(nftnl_obj_fprintf);
440 int nftnl_obj_fprintf(FILE *fp, const struct nftnl_obj *obj, uint32_t type,
441  uint32_t flags)
442 {
443  return nftnl_fprintf(fp, obj, NFTNL_CMD_UNSPEC, type, flags,
444  nftnl_obj_do_snprintf);
445 }
446 
448  struct list_head list;
449 };
450 
451 EXPORT_SYMBOL(nftnl_obj_list_alloc);
452 struct nftnl_obj_list *nftnl_obj_list_alloc(void)
453 {
454  struct nftnl_obj_list *list;
455 
456  list = calloc(1, sizeof(struct nftnl_obj_list));
457  if (list == NULL)
458  return NULL;
459 
460  INIT_LIST_HEAD(&list->list);
461 
462  return list;
463 }
464 
465 EXPORT_SYMBOL(nftnl_obj_list_free);
466 void nftnl_obj_list_free(struct nftnl_obj_list *list)
467 {
468  struct nftnl_obj *r, *tmp;
469 
470  list_for_each_entry_safe(r, tmp, &list->list, head) {
471  list_del(&r->head);
472  nftnl_obj_free(r);
473  }
474  xfree(list);
475 }
476 
477 EXPORT_SYMBOL(nftnl_obj_list_is_empty);
478 int nftnl_obj_list_is_empty(struct nftnl_obj_list *list)
479 {
480  return list_empty(&list->list);
481 }
482 
483 EXPORT_SYMBOL(nftnl_obj_list_add);
484 void nftnl_obj_list_add(struct nftnl_obj *r, struct nftnl_obj_list *list)
485 {
486  list_add(&r->head, &list->list);
487 }
488 
489 EXPORT_SYMBOL(nftnl_obj_list_add_tail);
490 void nftnl_obj_list_add_tail(struct nftnl_obj *r,
491  struct nftnl_obj_list *list)
492 {
493  list_add_tail(&r->head, &list->list);
494 }
495 
496 EXPORT_SYMBOL(nftnl_obj_list_del);
497 void nftnl_obj_list_del(struct nftnl_obj *t)
498 {
499  list_del(&t->head);
500 }
501 
502 EXPORT_SYMBOL(nftnl_obj_list_foreach);
503 int nftnl_obj_list_foreach(struct nftnl_obj_list *table_list,
504  int (*cb)(struct nftnl_obj *t, void *data),
505  void *data)
506 {
507  struct nftnl_obj *cur, *tmp;
508  int ret;
509 
510  list_for_each_entry_safe(cur, tmp, &table_list->list, head) {
511  ret = cb(cur, data);
512  if (ret < 0)
513  return ret;
514  }
515  return 0;
516 }
517 
519  struct nftnl_obj_list *list;
520  struct nftnl_obj *cur;
521 };
522 
523 EXPORT_SYMBOL(nftnl_obj_list_iter_create);
524 struct nftnl_obj_list_iter *
525 nftnl_obj_list_iter_create(struct nftnl_obj_list *l)
526 {
527  struct nftnl_obj_list_iter *iter;
528 
529  iter = calloc(1, sizeof(struct nftnl_obj_list_iter));
530  if (iter == NULL)
531  return NULL;
532 
533  iter->list = l;
534  if (nftnl_obj_list_is_empty(l))
535  iter->cur = NULL;
536  else
537  iter->cur = list_entry(l->list.next, struct nftnl_obj, head);
538 
539  return iter;
540 }
541 
542 EXPORT_SYMBOL(nftnl_obj_list_iter_next);
543 struct nftnl_obj *nftnl_obj_list_iter_next(struct nftnl_obj_list_iter *iter)
544 {
545  struct nftnl_obj *r = iter->cur;
546 
547  if (r == NULL)
548  return NULL;
549 
550  /* get next table, if any */
551  iter->cur = list_entry(iter->cur->head.next, struct nftnl_obj, head);
552  if (&iter->cur->head == iter->list->list.next)
553  return NULL;
554 
555  return r;
556 }
557 
558 EXPORT_SYMBOL(nftnl_obj_list_iter_destroy);
559 void nftnl_obj_list_iter_destroy(struct nftnl_obj_list_iter *iter)
560 {
561  xfree(iter);
562 }