libnftnl  1.2.8
dup.c
1 /*
2  * (C) 2015 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 
10 #include <stdio.h>
11 #include <stdint.h>
12 #include <string.h>
13 #include <arpa/inet.h>
14 #include <errno.h>
15 #include "internal.h"
16 #include <libmnl/libmnl.h>
17 #include <linux/netfilter/nf_tables.h>
18 #include <libnftnl/expr.h>
19 #include <libnftnl/rule.h>
20 #include "expr_ops.h"
21 #include "data_reg.h"
22 
24  enum nft_registers sreg_addr;
25  enum nft_registers sreg_dev;
26 };
27 
28 static int nftnl_expr_dup_set(struct nftnl_expr *e, uint16_t type,
29  const void *data, uint32_t data_len)
30 {
31  struct nftnl_expr_dup *dup = nftnl_expr_data(e);
32 
33  switch (type) {
34  case NFTNL_EXPR_DUP_SREG_ADDR:
35  memcpy(&dup->sreg_addr, data, data_len);
36  break;
37  case NFTNL_EXPR_DUP_SREG_DEV:
38  memcpy(&dup->sreg_dev, data, data_len);
39  break;
40  }
41  return 0;
42 }
43 
44 static const void *nftnl_expr_dup_get(const struct nftnl_expr *e,
45  uint16_t type, uint32_t *data_len)
46 {
47  struct nftnl_expr_dup *dup = nftnl_expr_data(e);
48 
49  switch (type) {
50  case NFTNL_EXPR_DUP_SREG_ADDR:
51  *data_len = sizeof(dup->sreg_addr);
52  return &dup->sreg_addr;
53  case NFTNL_EXPR_DUP_SREG_DEV:
54  *data_len = sizeof(dup->sreg_dev);
55  return &dup->sreg_dev;
56  }
57  return NULL;
58 }
59 
60 static int nftnl_expr_dup_cb(const struct nlattr *attr, void *data)
61 {
62  const struct nlattr **tb = data;
63  int type = mnl_attr_get_type(attr);
64 
65  if (mnl_attr_type_valid(attr, NFTA_DUP_MAX) < 0)
66  return MNL_CB_OK;
67 
68  switch (type) {
69  case NFTA_DUP_SREG_ADDR:
70  case NFTA_DUP_SREG_DEV:
71  if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
72  abi_breakage();
73  break;
74  }
75 
76  tb[type] = attr;
77  return MNL_CB_OK;
78 }
79 
80 static void nftnl_expr_dup_build(struct nlmsghdr *nlh,
81  const struct nftnl_expr *e)
82 {
83  struct nftnl_expr_dup *dup = nftnl_expr_data(e);
84 
85  if (e->flags & (1 << NFTNL_EXPR_DUP_SREG_ADDR))
86  mnl_attr_put_u32(nlh, NFTA_DUP_SREG_ADDR, htonl(dup->sreg_addr));
87  if (e->flags & (1 << NFTNL_EXPR_DUP_SREG_DEV))
88  mnl_attr_put_u32(nlh, NFTA_DUP_SREG_DEV, htonl(dup->sreg_dev));
89 }
90 
91 static int nftnl_expr_dup_parse(struct nftnl_expr *e, struct nlattr *attr)
92 {
93  struct nftnl_expr_dup *dup = nftnl_expr_data(e);
94  struct nlattr *tb[NFTA_DUP_MAX + 1] = {};
95  int ret = 0;
96 
97  if (mnl_attr_parse_nested(attr, nftnl_expr_dup_cb, tb) < 0)
98  return -1;
99 
100  if (tb[NFTA_DUP_SREG_ADDR]) {
101  dup->sreg_addr = ntohl(mnl_attr_get_u32(tb[NFTA_DUP_SREG_ADDR]));
102  e->flags |= (1 << NFTNL_EXPR_DUP_SREG_ADDR);
103  }
104  if (tb[NFTA_DUP_SREG_DEV]) {
105  dup->sreg_dev = ntohl(mnl_attr_get_u32(tb[NFTA_DUP_SREG_DEV]));
106  e->flags |= (1 << NFTNL_EXPR_DUP_SREG_DEV);
107  }
108 
109  return ret;
110 }
111 
112 static int nftnl_expr_dup_snprintf(char *buf, size_t remain,
113  uint32_t flags, const struct nftnl_expr *e)
114 {
115  struct nftnl_expr_dup *dup = nftnl_expr_data(e);
116  int offset = 0, ret;
117 
118  if (e->flags & (1 << NFTNL_EXPR_DUP_SREG_ADDR)) {
119  ret = snprintf(buf + offset, remain, "sreg_addr %u ", dup->sreg_addr);
120  SNPRINTF_BUFFER_SIZE(ret, remain, offset);
121  }
122 
123  if (e->flags & (1 << NFTNL_EXPR_DUP_SREG_DEV)) {
124  ret = snprintf(buf + offset, remain, "sreg_dev %u ", dup->sreg_dev);
125  SNPRINTF_BUFFER_SIZE(ret, remain, offset);
126  }
127 
128  return offset;
129 }
130 
131 static struct attr_policy dup_attr_policy[__NFTNL_EXPR_DUP_MAX] = {
132  [NFTNL_EXPR_DUP_SREG_ADDR] = { .maxlen = sizeof(uint32_t) },
133  [NFTNL_EXPR_DUP_SREG_DEV] = { .maxlen = sizeof(uint32_t) },
134 };
135 
136 struct expr_ops expr_ops_dup = {
137  .name = "dup",
138  .alloc_len = sizeof(struct nftnl_expr_dup),
139  .nftnl_max_attr = __NFTNL_EXPR_DUP_MAX - 1,
140  .attr_policy = dup_attr_policy,
141  .set = nftnl_expr_dup_set,
142  .get = nftnl_expr_dup_get,
143  .parse = nftnl_expr_dup_parse,
144  .build = nftnl_expr_dup_build,
145  .output = nftnl_expr_dup_snprintf,
146 };