libnftnl  1.2.3
fwd.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_dev;
25  enum nft_registers sreg_addr;
26  uint32_t nfproto;
27 };
28 
29 static int nftnl_expr_fwd_set(struct nftnl_expr *e, uint16_t type,
30  const void *data, uint32_t data_len)
31 {
32  struct nftnl_expr_fwd *fwd = nftnl_expr_data(e);
33 
34  switch (type) {
35  case NFTNL_EXPR_FWD_SREG_DEV:
36  memcpy(&fwd->sreg_dev, data, sizeof(fwd->sreg_dev));
37  break;
38  case NFTNL_EXPR_FWD_SREG_ADDR:
39  memcpy(&fwd->sreg_addr, data, sizeof(fwd->sreg_addr));
40  break;
41  case NFTNL_EXPR_FWD_NFPROTO:
42  memcpy(&fwd->nfproto, data, sizeof(fwd->nfproto));
43  break;
44  default:
45  return -1;
46  }
47  return 0;
48 }
49 
50 static const void *nftnl_expr_fwd_get(const struct nftnl_expr *e,
51  uint16_t type, uint32_t *data_len)
52 {
53  struct nftnl_expr_fwd *fwd = nftnl_expr_data(e);
54 
55  switch (type) {
56  case NFTNL_EXPR_FWD_SREG_DEV:
57  *data_len = sizeof(fwd->sreg_dev);
58  return &fwd->sreg_dev;
59  case NFTNL_EXPR_FWD_SREG_ADDR:
60  *data_len = sizeof(fwd->sreg_addr);
61  return &fwd->sreg_addr;
62  case NFTNL_EXPR_FWD_NFPROTO:
63  *data_len = sizeof(fwd->nfproto);
64  return &fwd->nfproto;
65  }
66  return NULL;
67 }
68 
69 static int nftnl_expr_fwd_cb(const struct nlattr *attr, void *data)
70 {
71  const struct nlattr **tb = data;
72  int type = mnl_attr_get_type(attr);
73 
74  if (mnl_attr_type_valid(attr, NFTA_FWD_MAX) < 0)
75  return MNL_CB_OK;
76 
77  switch (type) {
78  case NFTA_FWD_SREG_DEV:
79  case NFTA_FWD_SREG_ADDR:
80  case NFTA_FWD_NFPROTO:
81  if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
82  abi_breakage();
83  break;
84  }
85 
86  tb[type] = attr;
87  return MNL_CB_OK;
88 }
89 
90 static void nftnl_expr_fwd_build(struct nlmsghdr *nlh,
91  const struct nftnl_expr *e)
92 {
93  struct nftnl_expr_fwd *fwd = nftnl_expr_data(e);
94 
95  if (e->flags & (1 << NFTNL_EXPR_FWD_SREG_DEV))
96  mnl_attr_put_u32(nlh, NFTA_FWD_SREG_DEV, htonl(fwd->sreg_dev));
97  if (e->flags & (1 << NFTNL_EXPR_FWD_SREG_ADDR))
98  mnl_attr_put_u32(nlh, NFTA_FWD_SREG_ADDR, htonl(fwd->sreg_addr));
99  if (e->flags & (1 << NFTNL_EXPR_FWD_NFPROTO))
100  mnl_attr_put_u32(nlh, NFTA_FWD_NFPROTO, htonl(fwd->nfproto));
101 }
102 
103 static int nftnl_expr_fwd_parse(struct nftnl_expr *e, struct nlattr *attr)
104 {
105  struct nftnl_expr_fwd *fwd = nftnl_expr_data(e);
106  struct nlattr *tb[NFTA_FWD_MAX + 1] = {};
107  int ret = 0;
108 
109  if (mnl_attr_parse_nested(attr, nftnl_expr_fwd_cb, tb) < 0)
110  return -1;
111 
112  if (tb[NFTA_FWD_SREG_DEV]) {
113  fwd->sreg_dev = ntohl(mnl_attr_get_u32(tb[NFTA_FWD_SREG_DEV]));
114  e->flags |= (1 << NFTNL_EXPR_FWD_SREG_DEV);
115  }
116  if (tb[NFTA_FWD_SREG_ADDR]) {
117  fwd->sreg_addr = ntohl(mnl_attr_get_u32(tb[NFTA_FWD_SREG_ADDR]));
118  e->flags |= (1 << NFTNL_EXPR_FWD_SREG_ADDR);
119  }
120  if (tb[NFTA_FWD_NFPROTO]) {
121  fwd->nfproto = ntohl(mnl_attr_get_u32(tb[NFTA_FWD_NFPROTO]));
122  e->flags |= (1 << NFTNL_EXPR_FWD_NFPROTO);
123  }
124 
125  return ret;
126 }
127 
128 static int nftnl_expr_fwd_snprintf(char *buf, size_t remain,
129  uint32_t flags, const struct nftnl_expr *e)
130 {
131  struct nftnl_expr_fwd *fwd = nftnl_expr_data(e);
132  int offset = 0, ret;
133 
134  if (e->flags & (1 << NFTNL_EXPR_FWD_SREG_DEV)) {
135  ret = snprintf(buf + offset, remain, "sreg_dev %u ",
136  fwd->sreg_dev);
137  SNPRINTF_BUFFER_SIZE(ret, remain, offset);
138  }
139  if (e->flags & (1 << NFTNL_EXPR_FWD_SREG_ADDR)) {
140  ret = snprintf(buf + offset, remain, "sreg_addr %u ",
141  fwd->sreg_addr);
142  SNPRINTF_BUFFER_SIZE(ret, remain, offset);
143  }
144  if (e->flags & (1 << NFTNL_EXPR_FWD_NFPROTO)) {
145  ret = snprintf(buf + offset, remain, "nfproto %u ",
146  fwd->nfproto);
147  SNPRINTF_BUFFER_SIZE(ret, remain, offset);
148  }
149 
150  return offset;
151 }
152 
153 struct expr_ops expr_ops_fwd = {
154  .name = "fwd",
155  .alloc_len = sizeof(struct nftnl_expr_fwd),
156  .max_attr = NFTA_FWD_MAX,
157  .set = nftnl_expr_fwd_set,
158  .get = nftnl_expr_fwd_get,
159  .parse = nftnl_expr_fwd_parse,
160  .build = nftnl_expr_fwd_build,
161  .output = nftnl_expr_fwd_snprintf,
162 };
nftnl_expr_fwd
Definition: fwd.c:23