libnftnl 1.2.6
redir.c
1/*
2 * (C) 2014 by Arturo Borrero Gonzalez <arturo@debian.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 <arpa/inet.h>
13#include <errno.h>
14#include <inttypes.h>
15
16#include <linux/netfilter/nf_tables.h>
17
18#include "internal.h"
19#include <libmnl/libmnl.h>
20#include <libnftnl/expr.h>
21#include <libnftnl/rule.h>
22
24 enum nft_registers sreg_proto_min;
25 enum nft_registers sreg_proto_max;
26 uint32_t flags;
27};
28
29static int
30nftnl_expr_redir_set(struct nftnl_expr *e, uint16_t type,
31 const void *data, uint32_t data_len)
32{
33 struct nftnl_expr_redir *redir = nftnl_expr_data(e);
34
35 switch (type) {
36 case NFTNL_EXPR_REDIR_REG_PROTO_MIN:
37 memcpy(&redir->sreg_proto_min, data, sizeof(redir->sreg_proto_min));
38 break;
39 case NFTNL_EXPR_REDIR_REG_PROTO_MAX:
40 memcpy(&redir->sreg_proto_max, data, sizeof(redir->sreg_proto_max));
41 break;
42 case NFTNL_EXPR_REDIR_FLAGS:
43 memcpy(&redir->flags, data, sizeof(redir->flags));
44 break;
45 default:
46 return -1;
47 }
48 return 0;
49}
50
51static const void *
52nftnl_expr_redir_get(const struct nftnl_expr *e, uint16_t type,
53 uint32_t *data_len)
54{
55 struct nftnl_expr_redir *redir = nftnl_expr_data(e);
56
57 switch (type) {
58 case NFTNL_EXPR_REDIR_REG_PROTO_MIN:
59 *data_len = sizeof(redir->sreg_proto_min);
60 return &redir->sreg_proto_min;
61 case NFTNL_EXPR_REDIR_REG_PROTO_MAX:
62 *data_len = sizeof(redir->sreg_proto_max);
63 return &redir->sreg_proto_max;
64 case NFTNL_EXPR_REDIR_FLAGS:
65 *data_len = sizeof(redir->flags);
66 return &redir->flags;
67 }
68 return NULL;
69}
70
71static int nftnl_expr_redir_cb(const struct nlattr *attr, void *data)
72{
73 const struct nlattr **tb = data;
74 int type = mnl_attr_get_type(attr);
75
76 if (mnl_attr_type_valid(attr, NFTA_REDIR_MAX) < 0)
77 return MNL_CB_OK;
78
79 switch (type) {
80 case NFTA_REDIR_REG_PROTO_MIN:
81 case NFTA_REDIR_REG_PROTO_MAX:
82 case NFTA_REDIR_FLAGS:
83 if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
84 abi_breakage();
85 break;
86 }
87
88 tb[type] = attr;
89 return MNL_CB_OK;
90}
91
92static void
93nftnl_expr_redir_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
94{
95 struct nftnl_expr_redir *redir = nftnl_expr_data(e);
96
97 if (e->flags & (1 << NFTNL_EXPR_REDIR_REG_PROTO_MIN))
98 mnl_attr_put_u32(nlh, NFTA_REDIR_REG_PROTO_MIN,
99 htobe32(redir->sreg_proto_min));
100 if (e->flags & (1 << NFTNL_EXPR_REDIR_REG_PROTO_MAX))
101 mnl_attr_put_u32(nlh, NFTA_REDIR_REG_PROTO_MAX,
102 htobe32(redir->sreg_proto_max));
103 if (e->flags & (1 << NFTNL_EXPR_REDIR_FLAGS))
104 mnl_attr_put_u32(nlh, NFTA_REDIR_FLAGS, htobe32(redir->flags));
105}
106
107static int
108nftnl_expr_redir_parse(struct nftnl_expr *e, struct nlattr *attr)
109{
110 struct nftnl_expr_redir *redir = nftnl_expr_data(e);
111 struct nlattr *tb[NFTA_REDIR_MAX + 1] = {};
112
113 if (mnl_attr_parse_nested(attr, nftnl_expr_redir_cb, tb) < 0)
114 return -1;
115
116 if (tb[NFTA_REDIR_REG_PROTO_MIN]) {
117 redir->sreg_proto_min =
118 ntohl(mnl_attr_get_u32(tb[NFTA_REDIR_REG_PROTO_MIN]));
119 e->flags |= (1 << NFTNL_EXPR_REDIR_REG_PROTO_MIN);
120 }
121 if (tb[NFTA_REDIR_REG_PROTO_MAX]) {
122 redir->sreg_proto_max =
123 ntohl(mnl_attr_get_u32(tb[NFTA_REDIR_REG_PROTO_MAX]));
124 e->flags |= (1 << NFTNL_EXPR_REDIR_REG_PROTO_MAX);
125 }
126 if (tb[NFTA_REDIR_FLAGS]) {
127 redir->flags = be32toh(mnl_attr_get_u32(tb[NFTA_REDIR_FLAGS]));
128 e->flags |= (1 << NFTNL_EXPR_REDIR_FLAGS);
129 }
130
131 return 0;
132}
133
134static int
135nftnl_expr_redir_snprintf(char *buf, size_t remain,
136 uint32_t flags, const struct nftnl_expr *e)
137{
138 int ret, offset = 0;
139 struct nftnl_expr_redir *redir = nftnl_expr_data(e);
140
141 if (nftnl_expr_is_set(e, NFTNL_EXPR_REDIR_REG_PROTO_MIN)) {
142 ret = snprintf(buf + offset, remain, "proto_min reg %u ",
143 redir->sreg_proto_min);
144 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
145 }
146
147 if (nftnl_expr_is_set(e, NFTNL_EXPR_REDIR_REG_PROTO_MAX)) {
148 ret = snprintf(buf + offset, remain, "proto_max reg %u ",
149 redir->sreg_proto_max);
150 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
151 }
152
153 if (nftnl_expr_is_set(e, NFTNL_EXPR_REDIR_FLAGS)) {
154 ret = snprintf(buf + offset, remain, "flags 0x%x ",
155 redir->flags);
156 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
157 }
158
159 return offset;
160}
161
162struct expr_ops expr_ops_redir = {
163 .name = "redir",
164 .alloc_len = sizeof(struct nftnl_expr_redir),
165 .max_attr = NFTA_REDIR_MAX,
166 .set = nftnl_expr_redir_set,
167 .get = nftnl_expr_redir_get,
168 .parse = nftnl_expr_redir_parse,
169 .build = nftnl_expr_redir_build,
170 .output = nftnl_expr_redir_snprintf,
171};