libnftnl 1.2.8
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, data_len);
38 break;
39 case NFTNL_EXPR_REDIR_REG_PROTO_MAX:
40 memcpy(&redir->sreg_proto_max, data, data_len);
41 break;
42 case NFTNL_EXPR_REDIR_FLAGS:
43 memcpy(&redir->flags, data, data_len);
44 break;
45 }
46 return 0;
47}
48
49static const void *
50nftnl_expr_redir_get(const struct nftnl_expr *e, uint16_t type,
51 uint32_t *data_len)
52{
53 struct nftnl_expr_redir *redir = nftnl_expr_data(e);
54
55 switch (type) {
56 case NFTNL_EXPR_REDIR_REG_PROTO_MIN:
57 *data_len = sizeof(redir->sreg_proto_min);
58 return &redir->sreg_proto_min;
59 case NFTNL_EXPR_REDIR_REG_PROTO_MAX:
60 *data_len = sizeof(redir->sreg_proto_max);
61 return &redir->sreg_proto_max;
62 case NFTNL_EXPR_REDIR_FLAGS:
63 *data_len = sizeof(redir->flags);
64 return &redir->flags;
65 }
66 return NULL;
67}
68
69static int nftnl_expr_redir_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_REDIR_MAX) < 0)
75 return MNL_CB_OK;
76
77 switch (type) {
78 case NFTA_REDIR_REG_PROTO_MIN:
79 case NFTA_REDIR_REG_PROTO_MAX:
80 case NFTA_REDIR_FLAGS:
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
90static void
91nftnl_expr_redir_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
92{
93 struct nftnl_expr_redir *redir = nftnl_expr_data(e);
94
95 if (e->flags & (1 << NFTNL_EXPR_REDIR_REG_PROTO_MIN))
96 mnl_attr_put_u32(nlh, NFTA_REDIR_REG_PROTO_MIN,
97 htobe32(redir->sreg_proto_min));
98 if (e->flags & (1 << NFTNL_EXPR_REDIR_REG_PROTO_MAX))
99 mnl_attr_put_u32(nlh, NFTA_REDIR_REG_PROTO_MAX,
100 htobe32(redir->sreg_proto_max));
101 if (e->flags & (1 << NFTNL_EXPR_REDIR_FLAGS))
102 mnl_attr_put_u32(nlh, NFTA_REDIR_FLAGS, htobe32(redir->flags));
103}
104
105static int
106nftnl_expr_redir_parse(struct nftnl_expr *e, struct nlattr *attr)
107{
108 struct nftnl_expr_redir *redir = nftnl_expr_data(e);
109 struct nlattr *tb[NFTA_REDIR_MAX + 1] = {};
110
111 if (mnl_attr_parse_nested(attr, nftnl_expr_redir_cb, tb) < 0)
112 return -1;
113
114 if (tb[NFTA_REDIR_REG_PROTO_MIN]) {
115 redir->sreg_proto_min =
116 ntohl(mnl_attr_get_u32(tb[NFTA_REDIR_REG_PROTO_MIN]));
117 e->flags |= (1 << NFTNL_EXPR_REDIR_REG_PROTO_MIN);
118 }
119 if (tb[NFTA_REDIR_REG_PROTO_MAX]) {
120 redir->sreg_proto_max =
121 ntohl(mnl_attr_get_u32(tb[NFTA_REDIR_REG_PROTO_MAX]));
122 e->flags |= (1 << NFTNL_EXPR_REDIR_REG_PROTO_MAX);
123 }
124 if (tb[NFTA_REDIR_FLAGS]) {
125 redir->flags = be32toh(mnl_attr_get_u32(tb[NFTA_REDIR_FLAGS]));
126 e->flags |= (1 << NFTNL_EXPR_REDIR_FLAGS);
127 }
128
129 return 0;
130}
131
132static int
133nftnl_expr_redir_snprintf(char *buf, size_t remain,
134 uint32_t flags, const struct nftnl_expr *e)
135{
136 int ret, offset = 0;
137 struct nftnl_expr_redir *redir = nftnl_expr_data(e);
138
139 if (nftnl_expr_is_set(e, NFTNL_EXPR_REDIR_REG_PROTO_MIN)) {
140 ret = snprintf(buf + offset, remain, "proto_min reg %u ",
141 redir->sreg_proto_min);
142 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
143 }
144
145 if (nftnl_expr_is_set(e, NFTNL_EXPR_REDIR_REG_PROTO_MAX)) {
146 ret = snprintf(buf + offset, remain, "proto_max reg %u ",
147 redir->sreg_proto_max);
148 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
149 }
150
151 if (nftnl_expr_is_set(e, NFTNL_EXPR_REDIR_FLAGS)) {
152 ret = snprintf(buf + offset, remain, "flags 0x%x ",
153 redir->flags);
154 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
155 }
156
157 return offset;
158}
159
160static struct attr_policy redir_attr_policy[__NFTNL_EXPR_REDIR_MAX] = {
161 [NFTNL_EXPR_REDIR_REG_PROTO_MIN] = { .maxlen = sizeof(uint32_t) },
162 [NFTNL_EXPR_REDIR_REG_PROTO_MAX] = { .maxlen = sizeof(uint32_t) },
163 [NFTNL_EXPR_REDIR_FLAGS] = { .maxlen = sizeof(uint32_t) },
164};
165
166struct expr_ops expr_ops_redir = {
167 .name = "redir",
168 .alloc_len = sizeof(struct nftnl_expr_redir),
169 .nftnl_max_attr = __NFTNL_EXPR_REDIR_MAX - 1,
170 .attr_policy = redir_attr_policy,
171 .set = nftnl_expr_redir_set,
172 .get = nftnl_expr_redir_get,
173 .parse = nftnl_expr_redir_parse,
174 .build = nftnl_expr_redir_build,
175 .output = nftnl_expr_redir_snprintf,
176};