libnftnl  1.2.9
dup.c
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * (C) 2015 Pablo Neira Ayuso <pablo@netfilter.org>
4  */
5 
6 #include <stdio.h>
7 #include <stdint.h>
8 #include <string.h>
9 #include <arpa/inet.h>
10 #include <errno.h>
11 #include "internal.h"
12 #include <libmnl/libmnl.h>
13 #include <linux/netfilter/nf_tables.h>
14 #include <libnftnl/expr.h>
15 #include <libnftnl/rule.h>
16 #include "expr_ops.h"
17 #include "data_reg.h"
18 
20  enum nft_registers sreg_addr;
21  enum nft_registers sreg_dev;
22 };
23 
24 static int nftnl_expr_dup_set(struct nftnl_expr *e, uint16_t type,
25  const void *data, uint32_t data_len)
26 {
27  struct nftnl_expr_dup *dup = nftnl_expr_data(e);
28 
29  switch (type) {
30  case NFTNL_EXPR_DUP_SREG_ADDR:
31  memcpy(&dup->sreg_addr, data, data_len);
32  break;
33  case NFTNL_EXPR_DUP_SREG_DEV:
34  memcpy(&dup->sreg_dev, data, data_len);
35  break;
36  }
37  return 0;
38 }
39 
40 static const void *nftnl_expr_dup_get(const struct nftnl_expr *e,
41  uint16_t type, uint32_t *data_len)
42 {
43  struct nftnl_expr_dup *dup = nftnl_expr_data(e);
44 
45  switch (type) {
46  case NFTNL_EXPR_DUP_SREG_ADDR:
47  *data_len = sizeof(dup->sreg_addr);
48  return &dup->sreg_addr;
49  case NFTNL_EXPR_DUP_SREG_DEV:
50  *data_len = sizeof(dup->sreg_dev);
51  return &dup->sreg_dev;
52  }
53  return NULL;
54 }
55 
56 static int nftnl_expr_dup_cb(const struct nlattr *attr, void *data)
57 {
58  const struct nlattr **tb = data;
59  int type = mnl_attr_get_type(attr);
60 
61  if (mnl_attr_type_valid(attr, NFTA_DUP_MAX) < 0)
62  return MNL_CB_OK;
63 
64  switch (type) {
65  case NFTA_DUP_SREG_ADDR:
66  case NFTA_DUP_SREG_DEV:
67  if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
68  abi_breakage();
69  break;
70  }
71 
72  tb[type] = attr;
73  return MNL_CB_OK;
74 }
75 
76 static void nftnl_expr_dup_build(struct nlmsghdr *nlh,
77  const struct nftnl_expr *e)
78 {
79  struct nftnl_expr_dup *dup = nftnl_expr_data(e);
80 
81  if (e->flags & (1 << NFTNL_EXPR_DUP_SREG_ADDR))
82  mnl_attr_put_u32(nlh, NFTA_DUP_SREG_ADDR, htonl(dup->sreg_addr));
83  if (e->flags & (1 << NFTNL_EXPR_DUP_SREG_DEV))
84  mnl_attr_put_u32(nlh, NFTA_DUP_SREG_DEV, htonl(dup->sreg_dev));
85 }
86 
87 static int nftnl_expr_dup_parse(struct nftnl_expr *e, struct nlattr *attr)
88 {
89  struct nftnl_expr_dup *dup = nftnl_expr_data(e);
90  struct nlattr *tb[NFTA_DUP_MAX + 1] = {};
91  int ret = 0;
92 
93  if (mnl_attr_parse_nested(attr, nftnl_expr_dup_cb, tb) < 0)
94  return -1;
95 
96  if (tb[NFTA_DUP_SREG_ADDR]) {
97  dup->sreg_addr = ntohl(mnl_attr_get_u32(tb[NFTA_DUP_SREG_ADDR]));
98  e->flags |= (1 << NFTNL_EXPR_DUP_SREG_ADDR);
99  }
100  if (tb[NFTA_DUP_SREG_DEV]) {
101  dup->sreg_dev = ntohl(mnl_attr_get_u32(tb[NFTA_DUP_SREG_DEV]));
102  e->flags |= (1 << NFTNL_EXPR_DUP_SREG_DEV);
103  }
104 
105  return ret;
106 }
107 
108 static int nftnl_expr_dup_snprintf(char *buf, size_t remain,
109  uint32_t flags, const struct nftnl_expr *e)
110 {
111  struct nftnl_expr_dup *dup = nftnl_expr_data(e);
112  int offset = 0, ret;
113 
114  if (e->flags & (1 << NFTNL_EXPR_DUP_SREG_ADDR)) {
115  ret = snprintf(buf + offset, remain, "sreg_addr %u ", dup->sreg_addr);
116  SNPRINTF_BUFFER_SIZE(ret, remain, offset);
117  }
118 
119  if (e->flags & (1 << NFTNL_EXPR_DUP_SREG_DEV)) {
120  ret = snprintf(buf + offset, remain, "sreg_dev %u ", dup->sreg_dev);
121  SNPRINTF_BUFFER_SIZE(ret, remain, offset);
122  }
123 
124  return offset;
125 }
126 
127 static struct attr_policy dup_attr_policy[__NFTNL_EXPR_DUP_MAX] = {
128  [NFTNL_EXPR_DUP_SREG_ADDR] = { .maxlen = sizeof(uint32_t) },
129  [NFTNL_EXPR_DUP_SREG_DEV] = { .maxlen = sizeof(uint32_t) },
130 };
131 
132 struct expr_ops expr_ops_dup = {
133  .name = "dup",
134  .alloc_len = sizeof(struct nftnl_expr_dup),
135  .nftnl_max_attr = __NFTNL_EXPR_DUP_MAX - 1,
136  .attr_policy = dup_attr_policy,
137  .set = nftnl_expr_dup_set,
138  .get = nftnl_expr_dup_get,
139  .parse = nftnl_expr_dup_parse,
140  .build = nftnl_expr_dup_build,
141  .output = nftnl_expr_dup_snprintf,
142 };