libnftnl  1.0.6
log.c
1 /*
2  * (C) 2012-2013 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  * This code has been sponsored by Sophos Astaro <http://www.sophos.com>
10  */
11 
12 #include <stdio.h>
13 #include <stdint.h>
14 #include <string.h>
15 #include <arpa/inet.h>
16 #include <errno.h>
17 #include <linux/netfilter/nf_tables.h>
18 
19 #include "internal.h"
20 #include <libmnl/libmnl.h>
21 #include <libnftnl/expr.h>
22 #include <libnftnl/rule.h>
23 
25  uint32_t snaplen;
26  uint16_t group;
27  uint16_t qthreshold;
28  uint32_t level;
29  uint32_t flags;
30  const char *prefix;
31 };
32 
33 static int nftnl_expr_log_set(struct nftnl_expr *e, uint16_t type,
34  const void *data, uint32_t data_len)
35 {
36  struct nftnl_expr_log *log = nftnl_expr_data(e);
37 
38  switch(type) {
39  case NFTNL_EXPR_LOG_PREFIX:
40  if (log->prefix)
41  xfree(log->prefix);
42 
43  log->prefix = strdup(data);
44  break;
45  case NFTNL_EXPR_LOG_GROUP:
46  log->group = *((uint16_t *)data);
47  break;
48  case NFTNL_EXPR_LOG_SNAPLEN:
49  log->snaplen = *((uint32_t *)data);
50  break;
51  case NFTNL_EXPR_LOG_QTHRESHOLD:
52  log->qthreshold = *((uint16_t *)data);
53  break;
54  case NFTNL_EXPR_LOG_LEVEL:
55  log->level = *((uint32_t *)data);
56  break;
57  case NFTNL_EXPR_LOG_FLAGS:
58  log->flags = *((uint32_t *)data);
59  break;
60  default:
61  return -1;
62  }
63  return 0;
64 }
65 
66 static const void *
67 nftnl_expr_log_get(const struct nftnl_expr *e, uint16_t type,
68  uint32_t *data_len)
69 {
70  struct nftnl_expr_log *log = nftnl_expr_data(e);
71 
72  switch(type) {
73  case NFTNL_EXPR_LOG_PREFIX:
74  *data_len = strlen(log->prefix)+1;
75  return log->prefix;
76  case NFTNL_EXPR_LOG_GROUP:
77  *data_len = sizeof(log->group);
78  return &log->group;
79  case NFTNL_EXPR_LOG_SNAPLEN:
80  *data_len = sizeof(log->snaplen);
81  return &log->snaplen;
82  case NFTNL_EXPR_LOG_QTHRESHOLD:
83  *data_len = sizeof(log->qthreshold);
84  return &log->qthreshold;
85  case NFTNL_EXPR_LOG_LEVEL:
86  *data_len = sizeof(log->level);
87  return &log->level;
88  case NFTNL_EXPR_LOG_FLAGS:
89  *data_len = sizeof(log->flags);
90  return &log->flags;
91  }
92  return NULL;
93 }
94 
95 static int nftnl_expr_log_cb(const struct nlattr *attr, void *data)
96 {
97  const struct nlattr **tb = data;
98  int type = mnl_attr_get_type(attr);
99 
100  if (mnl_attr_type_valid(attr, NFTA_LOG_MAX) < 0)
101  return MNL_CB_OK;
102 
103  switch(type) {
104  case NFTA_LOG_PREFIX:
105  if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0)
106  abi_breakage();
107  break;
108  case NFTA_LOG_GROUP:
109  case NFTA_LOG_QTHRESHOLD:
110  if (mnl_attr_validate(attr, MNL_TYPE_U16) < 0)
111  abi_breakage();
112  break;
113  case NFTA_LOG_SNAPLEN:
114  case NFTA_LOG_LEVEL:
115  case NFTA_LOG_FLAGS:
116  if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
117  abi_breakage();
118  break;
119  }
120 
121  tb[type] = attr;
122  return MNL_CB_OK;
123 }
124 
125 static void
126 nftnl_expr_log_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
127 {
128  struct nftnl_expr_log *log = nftnl_expr_data(e);
129 
130  if (e->flags & (1 << NFTNL_EXPR_LOG_PREFIX))
131  mnl_attr_put_strz(nlh, NFTA_LOG_PREFIX, log->prefix);
132  if (e->flags & (1 << NFTNL_EXPR_LOG_GROUP))
133  mnl_attr_put_u16(nlh, NFTA_LOG_GROUP, htons(log->group));
134  if (e->flags & (1 << NFTNL_EXPR_LOG_SNAPLEN))
135  mnl_attr_put_u32(nlh, NFTA_LOG_SNAPLEN, htonl(log->snaplen));
136  if (e->flags & (1 << NFTNL_EXPR_LOG_QTHRESHOLD))
137  mnl_attr_put_u16(nlh, NFTA_LOG_QTHRESHOLD, htons(log->qthreshold));
138  if (e->flags & (1 << NFTNL_EXPR_LOG_LEVEL))
139  mnl_attr_put_u32(nlh, NFTA_LOG_LEVEL, htonl(log->level));
140  if (e->flags & (1 << NFTNL_EXPR_LOG_FLAGS))
141  mnl_attr_put_u32(nlh, NFTA_LOG_FLAGS, htonl(log->flags));
142 }
143 
144 static int
145 nftnl_expr_log_parse(struct nftnl_expr *e, struct nlattr *attr)
146 {
147  struct nftnl_expr_log *log = nftnl_expr_data(e);
148  struct nlattr *tb[NFTA_LOG_MAX+1] = {};
149 
150  if (mnl_attr_parse_nested(attr, nftnl_expr_log_cb, tb) < 0)
151  return -1;
152 
153  if (tb[NFTA_LOG_PREFIX]) {
154  if (log->prefix)
155  xfree(log->prefix);
156 
157  log->prefix = strdup(mnl_attr_get_str(tb[NFTA_LOG_PREFIX]));
158  e->flags |= (1 << NFTNL_EXPR_LOG_PREFIX);
159  }
160  if (tb[NFTA_LOG_GROUP]) {
161  log->group = ntohs(mnl_attr_get_u16(tb[NFTA_LOG_GROUP]));
162  e->flags |= (1 << NFTNL_EXPR_LOG_GROUP);
163  }
164  if (tb[NFTA_LOG_SNAPLEN]) {
165  log->snaplen = ntohl(mnl_attr_get_u32(tb[NFTA_LOG_SNAPLEN]));
166  e->flags |= (1 << NFTNL_EXPR_LOG_SNAPLEN);
167  }
168  if (tb[NFTA_LOG_QTHRESHOLD]) {
169  log->qthreshold = ntohs(mnl_attr_get_u16(tb[NFTA_LOG_QTHRESHOLD]));
170  e->flags |= (1 << NFTNL_EXPR_LOG_QTHRESHOLD);
171  }
172  if (tb[NFTA_LOG_LEVEL]) {
173  log->level = ntohl(mnl_attr_get_u32(tb[NFTA_LOG_LEVEL]));
174  e->flags |= (1 << NFTNL_EXPR_LOG_LEVEL);
175  }
176  if (tb[NFTA_LOG_FLAGS]) {
177  log->flags = ntohl(mnl_attr_get_u32(tb[NFTA_LOG_FLAGS]));
178  e->flags |= (1 << NFTNL_EXPR_LOG_FLAGS);
179  }
180 
181  return 0;
182 }
183 
184 static int nftnl_expr_log_json_parse(struct nftnl_expr *e, json_t *root,
185  struct nftnl_parse_err *err)
186 {
187 #ifdef JSON_PARSING
188  const char *prefix;
189  uint32_t snaplen, level, flags;
190  uint16_t group, qthreshold;
191 
192  prefix = nftnl_jansson_parse_str(root, "prefix", err);
193  if (prefix != NULL)
194  nftnl_expr_set_str(e, NFTNL_EXPR_LOG_PREFIX, prefix);
195 
196  if (nftnl_jansson_parse_val(root, "group", NFTNL_TYPE_U16, &group,
197  err) == 0)
198  nftnl_expr_set_u16(e, NFTNL_EXPR_LOG_GROUP, group);
199 
200  if (nftnl_jansson_parse_val(root, "snaplen", NFTNL_TYPE_U32, &snaplen,
201  err) == 0)
202  nftnl_expr_set_u32(e, NFTNL_EXPR_LOG_SNAPLEN, snaplen);
203 
204  if (nftnl_jansson_parse_val(root, "qthreshold", NFTNL_TYPE_U16,
205  &qthreshold, err) == 0)
206  nftnl_expr_set_u16(e, NFTNL_EXPR_LOG_QTHRESHOLD, qthreshold);
207 
208  if (nftnl_jansson_parse_val(root, "level", NFTNL_TYPE_U32, &level,
209  err) == 0)
210  nftnl_expr_set_u32(e, NFTNL_EXPR_LOG_LEVEL, level);
211 
212  if (nftnl_jansson_parse_val(root, "flags", NFTNL_TYPE_U32, &flags,
213  err) == 0)
214  nftnl_expr_set_u32(e, NFTNL_EXPR_LOG_FLAGS, flags);
215 
216  return 0;
217 #else
218  errno = EOPNOTSUPP;
219  return -1;
220 #endif
221 }
222 
223 static int nftnl_expr_log_xml_parse(struct nftnl_expr *e,
224  mxml_node_t *tree,
225  struct nftnl_parse_err *err)
226 {
227 #ifdef XML_PARSING
228  const char *prefix;
229  uint32_t snaplen, level, flags;
230  uint16_t group, qthreshold;
231 
232  prefix = nftnl_mxml_str_parse(tree, "prefix", MXML_DESCEND_FIRST,
233  NFTNL_XML_MAND, err);
234  if (prefix != NULL)
235  nftnl_expr_set_str(e, NFTNL_EXPR_LOG_PREFIX, prefix);
236 
237  if (nftnl_mxml_num_parse(tree, "group", MXML_DESCEND_FIRST, BASE_DEC,
238  &group, NFTNL_TYPE_U16, NFTNL_XML_MAND, err) == 0)
239  nftnl_expr_set_u16(e, NFTNL_EXPR_LOG_GROUP, group);
240 
241  if (nftnl_mxml_num_parse(tree, "snaplen", MXML_DESCEND_FIRST, BASE_DEC,
242  &snaplen, NFTNL_TYPE_U32, NFTNL_XML_MAND, err) == 0)
243  nftnl_expr_set_u32(e, NFTNL_EXPR_LOG_SNAPLEN, snaplen);
244 
245  if (nftnl_mxml_num_parse(tree, "qthreshold", MXML_DESCEND_FIRST, BASE_DEC,
246  &qthreshold, NFTNL_TYPE_U16, NFTNL_XML_MAND,
247  err) == 0)
248  nftnl_expr_set_u16(e, NFTNL_EXPR_LOG_QTHRESHOLD, qthreshold);
249 
250  if (nftnl_mxml_num_parse(tree, "level", MXML_DESCEND_FIRST, BASE_DEC,
251  &level, NFTNL_TYPE_U16, NFTNL_XML_MAND,
252  err) == 0)
253  nftnl_expr_set_u32(e, NFTNL_EXPR_LOG_LEVEL, level);
254 
255  if (nftnl_mxml_num_parse(tree, "flags", MXML_DESCEND_FIRST, BASE_DEC,
256  &flags, NFTNL_TYPE_U16, NFTNL_XML_MAND,
257  err) == 0)
258  nftnl_expr_set_u32(e, NFTNL_EXPR_LOG_FLAGS, flags);
259 
260  return 0;
261 #else
262  errno = EOPNOTSUPP;
263  return -1;
264 #endif
265 }
266 
267 static int nftnl_expr_log_snprintf_default(char *buf, size_t size,
268  const struct nftnl_expr *e)
269 {
270  struct nftnl_expr_log *log = nftnl_expr_data(e);
271  int ret, offset = 0, len = size;
272 
273  ret = snprintf(buf, len, "prefix %s ", log->prefix);
274  SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
275 
276  if (e->flags & (1 << NFTNL_EXPR_LOG_GROUP)) {
277  ret = snprintf(buf + offset, len,
278  "group %u snaplen %u qthreshold %u",
279  log->group, log->snaplen, log->qthreshold);
280  SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
281  } else if (e->flags & (1 << NFTNL_EXPR_LOG_LEVEL)) {
282  ret = snprintf(buf + offset, len, "level %u flags %u",
283  log->level, log->flags);
284  SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
285  }
286 
287  return offset;
288 }
289 
290 static int nftnl_expr_log_export(char *buf, size_t size,
291  const struct nftnl_expr *e, int type)
292 {
293  struct nftnl_expr_log *log = nftnl_expr_data(e);
294  NFTNL_BUF_INIT(b, buf, size);
295 
296  if (e->flags & (1 << NFTNL_EXPR_LOG_PREFIX))
297  nftnl_buf_str(&b, type, log->prefix, PREFIX);
298  if (e->flags & (1 << NFTNL_EXPR_LOG_GROUP))
299  nftnl_buf_u32(&b, type, log->group, GROUP);
300  if (e->flags & (1 << NFTNL_EXPR_LOG_SNAPLEN))
301  nftnl_buf_u32(&b, type, log->snaplen, SNAPLEN);
302  if (e->flags & (1 << NFTNL_EXPR_LOG_QTHRESHOLD))
303  nftnl_buf_u32(&b, type, log->qthreshold, QTHRESH);
304  if (e->flags & (1 << NFTNL_EXPR_LOG_LEVEL))
305  nftnl_buf_u32(&b, type, log->level, LEVEL);
306  if (e->flags & (1 << NFTNL_EXPR_LOG_FLAGS))
307  nftnl_buf_u32(&b, type, log->level, FLAGS);
308 
309  return nftnl_buf_done(&b);
310 }
311 
312 static int
313 nftnl_expr_log_snprintf(char *buf, size_t len, uint32_t type,
314  uint32_t flags, const struct nftnl_expr *e)
315 {
316  switch(type) {
317  case NFTNL_OUTPUT_DEFAULT:
318  return nftnl_expr_log_snprintf_default(buf, len, e);
319  case NFTNL_OUTPUT_XML:
320  case NFTNL_OUTPUT_JSON:
321  return nftnl_expr_log_export(buf, len, e, type);
322  default:
323  break;
324  }
325  return -1;
326 }
327 
328 static void nftnl_expr_log_free(const struct nftnl_expr *e)
329 {
330  struct nftnl_expr_log *log = nftnl_expr_data(e);
331 
332  xfree(log->prefix);
333 }
334 
335 struct expr_ops expr_ops_log = {
336  .name = "log",
337  .alloc_len = sizeof(struct nftnl_expr_log),
338  .max_attr = NFTA_LOG_MAX,
339  .free = nftnl_expr_log_free,
340  .set = nftnl_expr_log_set,
341  .get = nftnl_expr_log_get,
342  .parse = nftnl_expr_log_parse,
343  .build = nftnl_expr_log_build,
344  .snprintf = nftnl_expr_log_snprintf,
345  .xml_parse = nftnl_expr_log_xml_parse,
346  .json_parse = nftnl_expr_log_json_parse,
347 };