libnftnl  1.2.9
gen.c
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * (C) 2012-2014 by Pablo Neira Ayuso <pablo@netfilter.org>
4  */
5 #include "internal.h"
6 
7 #include <time.h>
8 #include <endian.h>
9 #include <stdint.h>
10 #include <limits.h>
11 #include <stdlib.h>
12 #include <string.h>
13 #include <netinet/in.h>
14 #include <errno.h>
15 
16 #include <libmnl/libmnl.h>
17 #include <linux/netfilter/nfnetlink.h>
18 #include <linux/netfilter/nf_tables.h>
19 
20 #include <libnftnl/gen.h>
21 
22 struct nftnl_gen {
23  uint32_t id;
24 
25  uint32_t flags;
26 };
27 
28 EXPORT_SYMBOL(nftnl_gen_alloc);
29 struct nftnl_gen *nftnl_gen_alloc(void)
30 {
31  return calloc(1, sizeof(struct nftnl_gen));
32 }
33 
34 EXPORT_SYMBOL(nftnl_gen_free);
35 void nftnl_gen_free(const struct nftnl_gen *gen)
36 {
37  xfree(gen);
38 }
39 
40 EXPORT_SYMBOL(nftnl_gen_is_set);
41 bool nftnl_gen_is_set(const struct nftnl_gen *gen, uint16_t attr)
42 {
43  return gen->flags & (1 << attr);
44 }
45 
46 EXPORT_SYMBOL(nftnl_gen_unset);
47 void nftnl_gen_unset(struct nftnl_gen *gen, uint16_t attr)
48 {
49  if (!(gen->flags & (1 << attr)))
50  return;
51 
52  switch (attr) {
53  case NFTNL_GEN_ID:
54  break;
55  }
56  gen->flags &= ~(1 << attr);
57 }
58 
59 static uint32_t nftnl_gen_validate[NFTNL_GEN_MAX + 1] = {
60  [NFTNL_GEN_ID] = sizeof(uint32_t),
61 };
62 
63 EXPORT_SYMBOL(nftnl_gen_set_data);
64 int nftnl_gen_set_data(struct nftnl_gen *gen, uint16_t attr,
65  const void *data, uint32_t data_len)
66 {
67  nftnl_assert_attr_exists(attr, NFTNL_GEN_MAX);
68  nftnl_assert_validate(data, nftnl_gen_validate, attr, data_len);
69 
70  switch (attr) {
71  case NFTNL_GEN_ID:
72  memcpy(&gen->id, data, sizeof(gen->id));
73  break;
74  }
75  gen->flags |= (1 << attr);
76  return 0;
77 }
78 
79 int nftnl_gen_set(struct nftnl_gen *gen, uint16_t attr, const void *data) __visible;
80 int nftnl_gen_set(struct nftnl_gen *gen, uint16_t attr, const void *data)
81 {
82  return nftnl_gen_set_data(gen, attr, data, nftnl_gen_validate[attr]);
83 }
84 
85 EXPORT_SYMBOL(nftnl_gen_set_u32);
86 void nftnl_gen_set_u32(struct nftnl_gen *gen, uint16_t attr, uint32_t val)
87 {
88  nftnl_gen_set_data(gen, attr, &val, sizeof(uint32_t));
89 }
90 
91 EXPORT_SYMBOL(nftnl_gen_get_data);
92 const void *nftnl_gen_get_data(const struct nftnl_gen *gen, uint16_t attr,
93  uint32_t *data_len)
94 {
95  if (!(gen->flags & (1 << attr)))
96  return NULL;
97 
98  switch(attr) {
99  case NFTNL_GEN_ID:
100  *data_len = sizeof(gen->id);
101  return &gen->id;
102  }
103  return NULL;
104 }
105 
106 EXPORT_SYMBOL(nftnl_gen_get);
107 const void *nftnl_gen_get(const struct nftnl_gen *gen, uint16_t attr)
108 {
109  uint32_t data_len;
110  return nftnl_gen_get_data(gen, attr, &data_len);
111 }
112 
113 EXPORT_SYMBOL(nftnl_gen_get_u32);
114 uint32_t nftnl_gen_get_u32(const struct nftnl_gen *gen, uint16_t attr)
115 {
116  const void *ret = nftnl_gen_get(gen, attr);
117  return ret == NULL ? 0 : *((uint32_t *)ret);
118 }
119 
120 static int nftnl_gen_parse_attr_cb(const struct nlattr *attr, void *data)
121 {
122  const struct nlattr **tb = data;
123  int type = mnl_attr_get_type(attr);
124 
125  if (mnl_attr_type_valid(attr, NFTA_GEN_MAX) < 0)
126  return MNL_CB_OK;
127 
128  switch(type) {
129  case NFTA_GEN_ID:
130  if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
131  abi_breakage();
132  break;
133  }
134 
135  tb[type] = attr;
136  return MNL_CB_OK;
137 }
138 
139 EXPORT_SYMBOL(nftnl_gen_nlmsg_parse);
140 int nftnl_gen_nlmsg_parse(const struct nlmsghdr *nlh, struct nftnl_gen *gen)
141 {
142  struct nlattr *tb[NFTA_GEN_MAX + 1] = {};
143 
144  if (mnl_attr_parse(nlh, sizeof(struct nfgenmsg),
145  nftnl_gen_parse_attr_cb, tb) < 0)
146  return -1;
147 
148  if (tb[NFTA_GEN_ID]) {
149  gen->id = ntohl(mnl_attr_get_u32(tb[NFTA_GEN_ID]));
150  gen->flags |= (1 << NFTNL_GEN_ID);
151  }
152  return 0;
153 }
154 
155 static int nftnl_gen_cmd_snprintf(char *buf, size_t remain,
156  const struct nftnl_gen *gen, uint32_t cmd,
157  uint32_t type, uint32_t flags)
158 {
159  int ret, offset = 0;
160 
161  if (type != NFTNL_OUTPUT_DEFAULT)
162  return -1;
163 
164  ret = snprintf(buf, remain, "ruleset generation ID %u", gen->id);
165  SNPRINTF_BUFFER_SIZE(ret, remain, offset);
166  return offset;
167 }
168 
169 EXPORT_SYMBOL(nftnl_gen_snprintf);
170 int nftnl_gen_snprintf(char *buf, size_t size, const struct nftnl_gen *gen,
171  uint32_t type, uint32_t flags)
172 {
173  if (size)
174  buf[0] = '\0';
175 
176  return nftnl_gen_cmd_snprintf(buf, size, gen, nftnl_flag2cmd(flags), type,
177  flags);
178 }
179 
180 static int nftnl_gen_do_snprintf(char *buf, size_t size, const void *gen,
181  uint32_t cmd, uint32_t type, uint32_t flags)
182 {
183  return nftnl_gen_snprintf(buf, size, gen, type, flags);
184 }
185 
186 EXPORT_SYMBOL(nftnl_gen_fprintf);
187 int nftnl_gen_fprintf(FILE *fp, const struct nftnl_gen *gen, uint32_t type,
188  uint32_t flags)
189 {
190  return nftnl_fprintf(fp, gen, NFTNL_CMD_UNSPEC, type, flags,
191  nftnl_gen_do_snprintf);
192 }
Definition: gen.c:22