libnftnl  1.1.4
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 #include <buffer.h>
23 
25  enum nft_registers sreg_addr;
26  enum nft_registers sreg_dev;
27 };
28 
29 static int nftnl_expr_dup_set(struct nftnl_expr *e, uint16_t type,
30  const void *data, uint32_t data_len)
31 {
32  struct nftnl_expr_dup *dup = nftnl_expr_data(e);
33 
34  switch (type) {
35  case NFTNL_EXPR_DUP_SREG_ADDR:
36  memcpy(&dup->sreg_addr, data, sizeof(dup->sreg_addr));
37  break;
38  case NFTNL_EXPR_DUP_SREG_DEV:
39  memcpy(&dup->sreg_dev, data, sizeof(dup->sreg_dev));
40  break;
41  default:
42  return -1;
43  }
44  return 0;
45 }
46 
47 static const void *nftnl_expr_dup_get(const struct nftnl_expr *e,
48  uint16_t type, uint32_t *data_len)
49 {
50  struct nftnl_expr_dup *dup = nftnl_expr_data(e);
51 
52  switch (type) {
53  case NFTNL_EXPR_DUP_SREG_ADDR:
54  *data_len = sizeof(dup->sreg_addr);
55  return &dup->sreg_addr;
56  case NFTNL_EXPR_DUP_SREG_DEV:
57  *data_len = sizeof(dup->sreg_dev);
58  return &dup->sreg_dev;
59  }
60  return NULL;
61 }
62 
63 static int nftnl_expr_dup_cb(const struct nlattr *attr, void *data)
64 {
65  const struct nlattr **tb = data;
66  int type = mnl_attr_get_type(attr);
67 
68  if (mnl_attr_type_valid(attr, NFTA_DUP_MAX) < 0)
69  return MNL_CB_OK;
70 
71  switch (type) {
72  case NFTA_DUP_SREG_ADDR:
73  case NFTA_DUP_SREG_DEV:
74  if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
75  abi_breakage();
76  break;
77  }
78 
79  tb[type] = attr;
80  return MNL_CB_OK;
81 }
82 
83 static void nftnl_expr_dup_build(struct nlmsghdr *nlh,
84  const struct nftnl_expr *e)
85 {
86  struct nftnl_expr_dup *dup = nftnl_expr_data(e);
87 
88  if (e->flags & (1 << NFTNL_EXPR_DUP_SREG_ADDR))
89  mnl_attr_put_u32(nlh, NFTA_DUP_SREG_ADDR, htonl(dup->sreg_addr));
90  if (e->flags & (1 << NFTNL_EXPR_DUP_SREG_DEV))
91  mnl_attr_put_u32(nlh, NFTA_DUP_SREG_DEV, htonl(dup->sreg_dev));
92 }
93 
94 static int nftnl_expr_dup_parse(struct nftnl_expr *e, struct nlattr *attr)
95 {
96  struct nftnl_expr_dup *dup = nftnl_expr_data(e);
97  struct nlattr *tb[NFTA_DUP_MAX + 1] = {};
98  int ret = 0;
99 
100  if (mnl_attr_parse_nested(attr, nftnl_expr_dup_cb, tb) < 0)
101  return -1;
102 
103  if (tb[NFTA_DUP_SREG_ADDR]) {
104  dup->sreg_addr = ntohl(mnl_attr_get_u32(tb[NFTA_DUP_SREG_ADDR]));
105  e->flags |= (1 << NFTNL_EXPR_DUP_SREG_ADDR);
106  }
107  if (tb[NFTA_DUP_SREG_DEV]) {
108  dup->sreg_dev = ntohl(mnl_attr_get_u32(tb[NFTA_DUP_SREG_DEV]));
109  e->flags |= (1 << NFTNL_EXPR_DUP_SREG_DEV);
110  }
111 
112  return ret;
113 }
114 
115 static int nftnl_expr_dup_snprintf_default(char *buf, size_t len,
116  const struct nftnl_expr *e,
117  uint32_t flags)
118 {
119  int remain = len, offset = 0, ret;
120  struct nftnl_expr_dup *dup = nftnl_expr_data(e);
121 
122  if (e->flags & (1 << NFTNL_EXPR_DUP_SREG_ADDR)) {
123  ret = snprintf(buf + offset, len, "sreg_addr %u ", dup->sreg_addr);
124  SNPRINTF_BUFFER_SIZE(ret, remain, offset);
125  }
126 
127  if (e->flags & (1 << NFTNL_EXPR_DUP_SREG_DEV)) {
128  ret = snprintf(buf + offset, len, "sreg_dev %u ", dup->sreg_dev);
129  SNPRINTF_BUFFER_SIZE(ret, remain, offset);
130  }
131 
132  return offset;
133 }
134 
135 static int nftnl_expr_dup_snprintf(char *buf, size_t len, uint32_t type,
136  uint32_t flags, const struct nftnl_expr *e)
137 {
138  switch (type) {
139  case NFTNL_OUTPUT_DEFAULT:
140  return nftnl_expr_dup_snprintf_default(buf, len, e, flags);
141  case NFTNL_OUTPUT_XML:
142  case NFTNL_OUTPUT_JSON:
143  default:
144  break;
145  }
146  return -1;
147 }
148 
149 struct expr_ops expr_ops_dup = {
150  .name = "dup",
151  .alloc_len = sizeof(struct nftnl_expr_dup),
152  .max_attr = NFTA_DUP_MAX,
153  .set = nftnl_expr_dup_set,
154  .get = nftnl_expr_dup_get,
155  .parse = nftnl_expr_dup_parse,
156  .build = nftnl_expr_dup_build,
157  .snprintf = nftnl_expr_dup_snprintf,
158 };