libnftnl  1.2.0
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 EXPORT_SYMBOL(nftnl_gen_alloc);
33 struct nftnl_gen *nftnl_gen_alloc(void)
34 {
35  return calloc(1, sizeof(struct nftnl_gen));
36 }
37 
38 EXPORT_SYMBOL(nftnl_gen_free);
39 void nftnl_gen_free(const struct nftnl_gen *gen)
40 {
41  xfree(gen);
42 }
43 
44 EXPORT_SYMBOL(nftnl_gen_is_set);
45 bool nftnl_gen_is_set(const struct nftnl_gen *gen, uint16_t attr)
46 {
47  return gen->flags & (1 << attr);
48 }
49 
50 EXPORT_SYMBOL(nftnl_gen_unset);
51 void nftnl_gen_unset(struct nftnl_gen *gen, uint16_t attr)
52 {
53  if (!(gen->flags & (1 << attr)))
54  return;
55 
56  switch (attr) {
57  case NFTNL_GEN_ID:
58  break;
59  }
60  gen->flags &= ~(1 << attr);
61 }
62 
63 static uint32_t nftnl_gen_validate[NFTNL_GEN_MAX + 1] = {
64  [NFTNL_GEN_ID] = sizeof(uint32_t),
65 };
66 
67 EXPORT_SYMBOL(nftnl_gen_set_data);
68 int nftnl_gen_set_data(struct nftnl_gen *gen, uint16_t attr,
69  const void *data, uint32_t data_len)
70 {
71  nftnl_assert_attr_exists(attr, NFTNL_GEN_MAX);
72  nftnl_assert_validate(data, nftnl_gen_validate, attr, data_len);
73 
74  switch (attr) {
75  case NFTNL_GEN_ID:
76  memcpy(&gen->id, data, sizeof(gen->id));
77  break;
78  }
79  gen->flags |= (1 << attr);
80  return 0;
81 }
82 
83 int nftnl_gen_set(struct nftnl_gen *gen, uint16_t attr, const void *data) __visible;
84 int nftnl_gen_set(struct nftnl_gen *gen, uint16_t attr, const void *data)
85 {
86  return nftnl_gen_set_data(gen, attr, data, nftnl_gen_validate[attr]);
87 }
88 
89 EXPORT_SYMBOL(nftnl_gen_set_u32);
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 
95 EXPORT_SYMBOL(nftnl_gen_get_data);
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  *data_len = sizeof(gen->id);
105  return &gen->id;
106  }
107  return NULL;
108 }
109 
110 EXPORT_SYMBOL(nftnl_gen_get);
111 const void *nftnl_gen_get(const struct nftnl_gen *gen, uint16_t attr)
112 {
113  uint32_t data_len;
114  return nftnl_gen_get_data(gen, attr, &data_len);
115 }
116 
117 EXPORT_SYMBOL(nftnl_gen_get_u32);
118 uint32_t nftnl_gen_get_u32(const struct nftnl_gen *gen, uint16_t attr)
119 {
120  const void *ret = nftnl_gen_get(gen, attr);
121  return ret == NULL ? 0 : *((uint32_t *)ret);
122 }
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 EXPORT_SYMBOL(nftnl_gen_nlmsg_parse);
144 int nftnl_gen_nlmsg_parse(const struct nlmsghdr *nlh, struct nftnl_gen *gen)
145 {
146  struct nlattr *tb[NFTA_GEN_MAX + 1] = {};
147 
148  if (mnl_attr_parse(nlh, sizeof(struct nfgenmsg),
149  nftnl_gen_parse_attr_cb, tb) < 0)
150  return -1;
151 
152  if (tb[NFTA_GEN_ID]) {
153  gen->id = ntohl(mnl_attr_get_u32(tb[NFTA_GEN_ID]));
154  gen->flags |= (1 << NFTNL_GEN_ID);
155  }
156  return 0;
157 }
158 
159 static int nftnl_gen_cmd_snprintf(char *buf, size_t remain,
160  const struct nftnl_gen *gen, uint32_t cmd,
161  uint32_t type, uint32_t flags)
162 {
163  int ret, offset = 0;
164 
165  if (type != NFTNL_OUTPUT_DEFAULT)
166  return -1;
167 
168  ret = snprintf(buf, remain, "ruleset generation ID %u", gen->id);
169  SNPRINTF_BUFFER_SIZE(ret, remain, offset);
170  return offset;
171 }
172 
173 EXPORT_SYMBOL(nftnl_gen_snprintf);
174 int nftnl_gen_snprintf(char *buf, size_t size, const struct nftnl_gen *gen,
175  uint32_t type, uint32_t flags)
176 {
177  if (size)
178  buf[0] = '\0';
179 
180  return nftnl_gen_cmd_snprintf(buf, size, gen, nftnl_flag2cmd(flags), type,
181  flags);
182 }
183 
184 static int nftnl_gen_do_snprintf(char *buf, size_t size, const void *gen,
185  uint32_t cmd, uint32_t type, uint32_t flags)
186 {
187  return nftnl_gen_snprintf(buf, size, gen, type, flags);
188 }
189 
190 EXPORT_SYMBOL(nftnl_gen_fprintf);
191 int nftnl_gen_fprintf(FILE *fp, const struct nftnl_gen *gen, uint32_t type,
192  uint32_t flags)
193 {
194  return nftnl_fprintf(fp, gen, NFTNL_CMD_UNSPEC, type, flags,
195  nftnl_gen_do_snprintf);
196 }
Definition: gen.c:26