libnftnl  1.2.1
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, sizeof(dup->sreg_addr));
36  break;
37  case NFTNL_EXPR_DUP_SREG_DEV:
38  memcpy(&dup->sreg_dev, data, sizeof(dup->sreg_dev));
39  break;
40  default:
41  return -1;
42  }
43  return 0;
44 }
45 
46 static const void *nftnl_expr_dup_get(const struct nftnl_expr *e,
47  uint16_t type, uint32_t *data_len)
48 {
49  struct nftnl_expr_dup *dup = nftnl_expr_data(e);
50 
51  switch (type) {
52  case NFTNL_EXPR_DUP_SREG_ADDR:
53  *data_len = sizeof(dup->sreg_addr);
54  return &dup->sreg_addr;
55  case NFTNL_EXPR_DUP_SREG_DEV:
56  *data_len = sizeof(dup->sreg_dev);
57  return &dup->sreg_dev;
58  }
59  return NULL;
60 }
61 
62 static int nftnl_expr_dup_cb(const struct nlattr *attr, void *data)
63 {
64  const struct nlattr **tb = data;
65  int type = mnl_attr_get_type(attr);
66 
67  if (mnl_attr_type_valid(attr, NFTA_DUP_MAX) < 0)
68  return MNL_CB_OK;
69 
70  switch (type) {
71  case NFTA_DUP_SREG_ADDR:
72  case NFTA_DUP_SREG_DEV:
73  if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
74  abi_breakage();
75  break;
76  }
77 
78  tb[type] = attr;
79  return MNL_CB_OK;
80 }
81 
82 static void nftnl_expr_dup_build(struct nlmsghdr *nlh,
83  const struct nftnl_expr *e)
84 {
85  struct nftnl_expr_dup *dup = nftnl_expr_data(e);
86 
87  if (e->flags & (1 << NFTNL_EXPR_DUP_SREG_ADDR))
88  mnl_attr_put_u32(nlh, NFTA_DUP_SREG_ADDR, htonl(dup->sreg_addr));
89  if (e->flags & (1 << NFTNL_EXPR_DUP_SREG_DEV))
90  mnl_attr_put_u32(nlh, NFTA_DUP_SREG_DEV, htonl(dup->sreg_dev));
91 }
92 
93 static int nftnl_expr_dup_parse(struct nftnl_expr *e, struct nlattr *attr)
94 {
95  struct nftnl_expr_dup *dup = nftnl_expr_data(e);
96  struct nlattr *tb[NFTA_DUP_MAX + 1] = {};
97  int ret = 0;
98 
99  if (mnl_attr_parse_nested(attr, nftnl_expr_dup_cb, tb) < 0)
100  return -1;
101 
102  if (tb[NFTA_DUP_SREG_ADDR]) {
103  dup->sreg_addr = ntohl(mnl_attr_get_u32(tb[NFTA_DUP_SREG_ADDR]));
104  e->flags |= (1 << NFTNL_EXPR_DUP_SREG_ADDR);
105  }
106  if (tb[NFTA_DUP_SREG_DEV]) {
107  dup->sreg_dev = ntohl(mnl_attr_get_u32(tb[NFTA_DUP_SREG_DEV]));
108  e->flags |= (1 << NFTNL_EXPR_DUP_SREG_DEV);
109  }
110 
111  return ret;
112 }
113 
114 static int nftnl_expr_dup_snprintf(char *buf, size_t remain,
115  uint32_t flags, const struct nftnl_expr *e)
116 {
117  struct nftnl_expr_dup *dup = nftnl_expr_data(e);
118  int offset = 0, ret;
119 
120  if (e->flags & (1 << NFTNL_EXPR_DUP_SREG_ADDR)) {
121  ret = snprintf(buf + offset, remain, "sreg_addr %u ", dup->sreg_addr);
122  SNPRINTF_BUFFER_SIZE(ret, remain, offset);
123  }
124 
125  if (e->flags & (1 << NFTNL_EXPR_DUP_SREG_DEV)) {
126  ret = snprintf(buf + offset, remain, "sreg_dev %u ", dup->sreg_dev);
127  SNPRINTF_BUFFER_SIZE(ret, remain, offset);
128  }
129 
130  return offset;
131 }
132 
133 struct expr_ops expr_ops_dup = {
134  .name = "dup",
135  .alloc_len = sizeof(struct nftnl_expr_dup),
136  .max_attr = NFTA_DUP_MAX,
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  .snprintf = nftnl_expr_dup_snprintf,
142 };