libnftnl  1.1.8
reject.c
1 /*
2  * (C) 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 type;
26  uint8_t icmp_code;
27 };
28 
29 static int nftnl_expr_reject_set(struct nftnl_expr *e, uint16_t type,
30  const void *data, uint32_t data_len)
31 {
32  struct nftnl_expr_reject *reject = nftnl_expr_data(e);
33 
34  switch(type) {
35  case NFTNL_EXPR_REJECT_TYPE:
36  memcpy(&reject->type, data, sizeof(reject->type));
37  break;
38  case NFTNL_EXPR_REJECT_CODE:
39  memcpy(&reject->icmp_code, data, sizeof(reject->icmp_code));
40  break;
41  default:
42  return -1;
43  }
44  return 0;
45 }
46 
47 static const void *
48 nftnl_expr_reject_get(const struct nftnl_expr *e, uint16_t type,
49  uint32_t *data_len)
50 {
51  struct nftnl_expr_reject *reject = nftnl_expr_data(e);
52 
53  switch(type) {
54  case NFTNL_EXPR_REJECT_TYPE:
55  *data_len = sizeof(reject->type);
56  return &reject->type;
57  case NFTNL_EXPR_REJECT_CODE:
58  *data_len = sizeof(reject->icmp_code);
59  return &reject->icmp_code;
60  }
61  return NULL;
62 }
63 
64 static int nftnl_expr_reject_cb(const struct nlattr *attr, void *data)
65 {
66  const struct nlattr **tb = data;
67  int type = mnl_attr_get_type(attr);
68 
69  if (mnl_attr_type_valid(attr, NFTA_REJECT_MAX) < 0)
70  return MNL_CB_OK;
71 
72  switch(type) {
73  case NFTA_REJECT_TYPE:
74  if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
75  abi_breakage();
76  break;
77  case NFTA_REJECT_ICMP_CODE:
78  if (mnl_attr_validate(attr, MNL_TYPE_U8) < 0)
79  abi_breakage();
80  break;
81  }
82 
83  tb[type] = attr;
84  return MNL_CB_OK;
85 }
86 
87 static void
88 nftnl_expr_reject_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
89 {
90  struct nftnl_expr_reject *reject = nftnl_expr_data(e);
91 
92  if (e->flags & (1 << NFTNL_EXPR_REJECT_TYPE))
93  mnl_attr_put_u32(nlh, NFTA_REJECT_TYPE, htonl(reject->type));
94  if (e->flags & (1 << NFTNL_EXPR_REJECT_CODE))
95  mnl_attr_put_u8(nlh, NFTA_REJECT_ICMP_CODE, reject->icmp_code);
96 }
97 
98 static int
99 nftnl_expr_reject_parse(struct nftnl_expr *e, struct nlattr *attr)
100 {
101  struct nftnl_expr_reject *reject = nftnl_expr_data(e);
102  struct nlattr *tb[NFTA_REJECT_MAX+1] = {};
103 
104  if (mnl_attr_parse_nested(attr, nftnl_expr_reject_cb, tb) < 0)
105  return -1;
106 
107  if (tb[NFTA_REJECT_TYPE]) {
108  reject->type = ntohl(mnl_attr_get_u32(tb[NFTA_REJECT_TYPE]));
109  e->flags |= (1 << NFTNL_EXPR_REJECT_TYPE);
110  }
111  if (tb[NFTA_REJECT_ICMP_CODE]) {
112  reject->icmp_code = mnl_attr_get_u8(tb[NFTA_REJECT_ICMP_CODE]);
113  e->flags |= (1 << NFTNL_EXPR_REJECT_CODE);
114  }
115 
116  return 0;
117 }
118 
119 static int nftnl_expr_reject_snprintf_default(char *buf, size_t len,
120  const struct nftnl_expr *e)
121 {
122  struct nftnl_expr_reject *reject = nftnl_expr_data(e);
123 
124  return snprintf(buf, len, "type %u code %u ",
125  reject->type, reject->icmp_code);
126 }
127 
128 static int
129 nftnl_expr_reject_snprintf(char *buf, size_t len, uint32_t type,
130  uint32_t flags, const struct nftnl_expr *e)
131 {
132  switch (type) {
133  case NFTNL_OUTPUT_DEFAULT:
134  return nftnl_expr_reject_snprintf_default(buf, len, e);
135  case NFTNL_OUTPUT_XML:
136  case NFTNL_OUTPUT_JSON:
137  default:
138  break;
139  }
140  return -1;
141 }
142 
143 struct expr_ops expr_ops_reject = {
144  .name = "reject",
145  .alloc_len = sizeof(struct nftnl_expr_reject),
146  .max_attr = NFTA_REJECT_MAX,
147  .set = nftnl_expr_reject_set,
148  .get = nftnl_expr_reject_get,
149  .parse = nftnl_expr_reject_parse,
150  .build = nftnl_expr_reject_build,
151  .snprintf = nftnl_expr_reject_snprintf,
152 };
nftnl_expr_reject
Definition: reject.c:24