libnftnl  1.0.6
gen.c
1 /*
2  * (C) 2012-2014 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/gen.h>
25 
26 struct nftnl_gen {
27  uint32_t id;
28 
29  uint32_t flags;
30 };
31 
32 struct nftnl_gen *nftnl_gen_alloc(void)
33 {
34  return calloc(1, sizeof(struct nftnl_gen));
35 }
36 EXPORT_SYMBOL_ALIAS(nftnl_gen_alloc, nft_gen_alloc);
37 
38 void nftnl_gen_free(const struct nftnl_gen *gen)
39 {
40  xfree(gen);
41 }
42 EXPORT_SYMBOL_ALIAS(nftnl_gen_free, nft_gen_free);
43 
44 bool nftnl_gen_is_set(const struct nftnl_gen *gen, uint16_t attr)
45 {
46  return gen->flags & (1 << attr);
47 }
48 EXPORT_SYMBOL_ALIAS(nftnl_gen_is_set, nft_gen_attr_is_set);
49 
50 void nftnl_gen_unset(struct nftnl_gen *gen, uint16_t attr)
51 {
52  if (!(gen->flags & (1 << attr)))
53  return;
54 
55  switch (attr) {
56  case NFTNL_GEN_ID:
57  break;
58  }
59  gen->flags &= ~(1 << attr);
60 }
61 EXPORT_SYMBOL_ALIAS(nftnl_gen_unset, nft_gen_attr_unset);
62 
63 static uint32_t nftnl_gen_validate[NFTNL_GEN_MAX + 1] = {
64  [NFTNL_GEN_ID] = sizeof(uint32_t),
65 };
66 
67 void nftnl_gen_set_data(struct nftnl_gen *gen, uint16_t attr,
68  const void *data, uint32_t data_len)
69 {
70  if (attr > NFTNL_GEN_MAX)
71  return;
72 
73  nftnl_assert_validate(data, nftnl_gen_validate, attr, data_len);
74 
75  switch (attr) {
76  case NFTNL_GEN_ID:
77  gen->id = *((uint32_t *)data);
78  break;
79  }
80  gen->flags |= (1 << attr);
81 }
82 EXPORT_SYMBOL_ALIAS(nftnl_gen_set_data, nft_gen_attr_set_data);
83 
84 void nftnl_gen_set(struct nftnl_gen *gen, uint16_t attr, const void *data)
85 {
86  nftnl_gen_set_data(gen, attr, data, nftnl_gen_validate[attr]);
87 }
88 EXPORT_SYMBOL_ALIAS(nftnl_gen_set, nft_gen_attr_set);
89 
90 void nftnl_gen_set_u32(struct nftnl_gen *gen, uint16_t attr, uint32_t val)
91 {
92  nftnl_gen_set_data(gen, attr, &val, sizeof(uint32_t));
93 }
94 EXPORT_SYMBOL_ALIAS(nftnl_gen_set_u32, nft_gen_attr_set_u32);
95 
96 const void *nftnl_gen_get_data(const struct nftnl_gen *gen, uint16_t attr,
97  uint32_t *data_len)
98 {
99  if (!(gen->flags & (1 << attr)))
100  return NULL;
101 
102  switch(attr) {
103  case NFTNL_GEN_ID:
104  return &gen->id;
105  }
106  return NULL;
107 }
108 EXPORT_SYMBOL_ALIAS(nftnl_gen_get_data, nft_gen_attr_get_data);
109 
110 const void *nftnl_gen_get(const struct nftnl_gen *gen, uint16_t attr)
111 {
112  uint32_t data_len;
113  return nftnl_gen_get_data(gen, attr, &data_len);
114 }
115 EXPORT_SYMBOL_ALIAS(nftnl_gen_get, nft_gen_attr_get);
116 
117 uint32_t nftnl_gen_get_u32(const struct nftnl_gen *gen, uint16_t attr)
118 {
119  const void *ret = nftnl_gen_get(gen, attr);
120  return ret == NULL ? 0 : *((uint32_t *)ret);
121 }
122 EXPORT_SYMBOL_ALIAS(nftnl_gen_get_u32, nft_gen_attr_get_u32);
123 
124 static int nftnl_gen_parse_attr_cb(const struct nlattr *attr, void *data)
125 {
126  const struct nlattr **tb = data;
127  int type = mnl_attr_get_type(attr);
128 
129  if (mnl_attr_type_valid(attr, NFTA_GEN_MAX) < 0)
130  return MNL_CB_OK;
131 
132  switch(type) {
133  case NFTA_GEN_ID:
134  if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
135  abi_breakage();
136  break;
137  }
138 
139  tb[type] = attr;
140  return MNL_CB_OK;
141 }
142 
143 int nftnl_gen_nlmsg_parse(const struct nlmsghdr *nlh, struct nftnl_gen *gen)
144 {
145  struct nlattr *tb[NFTA_GEN_MAX + 1] = {};
146  struct nfgenmsg *nfg = mnl_nlmsg_get_payload(nlh);
147 
148  if (mnl_attr_parse(nlh, sizeof(*nfg), nftnl_gen_parse_attr_cb, tb) < 0)
149  return -1;
150 
151  if (tb[NFTA_GEN_ID]) {
152  gen->id = ntohl(mnl_attr_get_u32(tb[NFTA_GEN_ID]));
153  gen->flags |= (1 << NFTNL_GEN_ID);
154  }
155  return 0;
156 }
157 EXPORT_SYMBOL_ALIAS(nftnl_gen_nlmsg_parse, nft_gen_nlmsg_parse);
158 
159 static int nftnl_gen_snprintf_default(char *buf, size_t size,
160  const struct nftnl_gen *gen)
161 {
162  return snprintf(buf, size, "ruleset generation ID %u", gen->id);
163 }
164 
165 static int nftnl_gen_cmd_snprintf(char *buf, size_t size,
166  const struct nftnl_gen *gen, uint32_t cmd,
167  uint32_t type, uint32_t flags)
168 {
169  int ret, len = size, offset = 0;
170 
171  ret = nftnl_cmd_header_snprintf(buf + offset, len, cmd, type, flags);
172  SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
173 
174  switch(type) {
175  case NFTNL_OUTPUT_DEFAULT:
176  ret = nftnl_gen_snprintf_default(buf + offset, len, gen);
177  break;
178  default:
179  return -1;
180  }
181  SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
182 
183  ret = nftnl_cmd_footer_snprintf(buf + offset, len, cmd, type, flags);
184  SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
185 
186  return offset;
187 }
188 
189 int nftnl_gen_snprintf(char *buf, size_t size, const struct nftnl_gen *gen,
190  uint32_t type, uint32_t flags)
191 {;
192  return nftnl_gen_cmd_snprintf(buf, size, gen, nftnl_flag2cmd(flags), type,
193  flags);
194 }
195 EXPORT_SYMBOL_ALIAS(nftnl_gen_snprintf, nft_gen_snprintf);
196 
197 static int nftnl_gen_do_snprintf(char *buf, size_t size, const void *gen,
198  uint32_t cmd, uint32_t type, uint32_t flags)
199 {
200  return nftnl_gen_snprintf(buf, size, gen, type, flags);
201 }
202 
203 int nftnl_gen_fprintf(FILE *fp, const struct nftnl_gen *gen, uint32_t type,
204  uint32_t flags)
205 {
206  return nftnl_fprintf(fp, gen, NFTNL_CMD_UNSPEC, type, flags,
207  nftnl_gen_do_snprintf);
208 }
209 EXPORT_SYMBOL_ALIAS(nftnl_gen_fprintf, nft_gen_fprintf);
Definition: gen.c:26