libnftnl 1.2.6
masq.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 uint32_t flags;
25 enum nft_registers sreg_proto_min;
26 enum nft_registers sreg_proto_max;
27};
28
29static int
30nftnl_expr_masq_set(struct nftnl_expr *e, uint16_t type,
31 const void *data, uint32_t data_len)
32{
33 struct nftnl_expr_masq *masq = nftnl_expr_data(e);
34
35 switch (type) {
36 case NFTNL_EXPR_MASQ_FLAGS:
37 memcpy(&masq->flags, data, sizeof(masq->flags));
38 break;
39 case NFTNL_EXPR_MASQ_REG_PROTO_MIN:
40 memcpy(&masq->sreg_proto_min, data, sizeof(masq->sreg_proto_min));
41 break;
42 case NFTNL_EXPR_MASQ_REG_PROTO_MAX:
43 memcpy(&masq->sreg_proto_max, data, sizeof(masq->sreg_proto_max));
44 break;
45 default:
46 return -1;
47 }
48 return 0;
49}
50
51static const void *
52nftnl_expr_masq_get(const struct nftnl_expr *e, uint16_t type,
53 uint32_t *data_len)
54{
55 struct nftnl_expr_masq *masq = nftnl_expr_data(e);
56
57 switch (type) {
58 case NFTNL_EXPR_MASQ_FLAGS:
59 *data_len = sizeof(masq->flags);
60 return &masq->flags;
61 case NFTNL_EXPR_MASQ_REG_PROTO_MIN:
62 *data_len = sizeof(masq->sreg_proto_min);
63 return &masq->sreg_proto_min;
64 case NFTNL_EXPR_MASQ_REG_PROTO_MAX:
65 *data_len = sizeof(masq->sreg_proto_max);
66 return &masq->sreg_proto_max;
67 }
68 return NULL;
69}
70
71static int nftnl_expr_masq_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_MASQ_MAX) < 0)
77 return MNL_CB_OK;
78
79 switch (type) {
80 case NFTA_MASQ_REG_PROTO_MIN:
81 case NFTA_MASQ_REG_PROTO_MAX:
82 case NFTA_MASQ_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_masq_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
94{
95 struct nftnl_expr_masq *masq = nftnl_expr_data(e);
96
97 if (e->flags & (1 << NFTNL_EXPR_MASQ_FLAGS))
98 mnl_attr_put_u32(nlh, NFTA_MASQ_FLAGS, htobe32(masq->flags));
99 if (e->flags & (1 << NFTNL_EXPR_MASQ_REG_PROTO_MIN))
100 mnl_attr_put_u32(nlh, NFTA_MASQ_REG_PROTO_MIN,
101 htobe32(masq->sreg_proto_min));
102 if (e->flags & (1 << NFTNL_EXPR_MASQ_REG_PROTO_MAX))
103 mnl_attr_put_u32(nlh, NFTA_MASQ_REG_PROTO_MAX,
104 htobe32(masq->sreg_proto_max));
105}
106
107static int
108nftnl_expr_masq_parse(struct nftnl_expr *e, struct nlattr *attr)
109{
110 struct nftnl_expr_masq *masq = nftnl_expr_data(e);
111 struct nlattr *tb[NFTA_MASQ_MAX+1] = {};
112
113 if (mnl_attr_parse_nested(attr, nftnl_expr_masq_cb, tb) < 0)
114 return -1;
115
116 if (tb[NFTA_MASQ_FLAGS]) {
117 masq->flags = be32toh(mnl_attr_get_u32(tb[NFTA_MASQ_FLAGS]));
118 e->flags |= (1 << NFTNL_EXPR_MASQ_FLAGS);
119 }
120 if (tb[NFTA_MASQ_REG_PROTO_MIN]) {
121 masq->sreg_proto_min =
122 be32toh(mnl_attr_get_u32(tb[NFTA_MASQ_REG_PROTO_MIN]));
123 e->flags |= (1 << NFTNL_EXPR_MASQ_REG_PROTO_MIN);
124 }
125 if (tb[NFTA_MASQ_REG_PROTO_MAX]) {
126 masq->sreg_proto_max =
127 be32toh(mnl_attr_get_u32(tb[NFTA_MASQ_REG_PROTO_MAX]));
128 e->flags |= (1 << NFTNL_EXPR_MASQ_REG_PROTO_MAX);
129 }
130
131 return 0;
132}
133
134static int nftnl_expr_masq_snprintf(char *buf, size_t remain,
135 uint32_t flags, const struct nftnl_expr *e)
136{
137 struct nftnl_expr_masq *masq = nftnl_expr_data(e);
138 int offset = 0, ret = 0;
139
140 if (e->flags & (1 << NFTNL_EXPR_MASQ_REG_PROTO_MIN)) {
141 ret = snprintf(buf + offset, remain, "proto_min reg %u ",
142 masq->sreg_proto_min);
143 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
144 }
145 if (e->flags & (1 << NFTNL_EXPR_MASQ_REG_PROTO_MAX)) {
146 ret = snprintf(buf + offset, remain, "proto_max reg %u ",
147 masq->sreg_proto_max);
148 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
149 }
150 if (e->flags & (1 << NFTNL_EXPR_MASQ_FLAGS)) {
151 ret = snprintf(buf + offset, remain, "flags 0x%x ", masq->flags);
152 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
153 }
154
155 return offset;
156}
157
158struct expr_ops expr_ops_masq = {
159 .name = "masq",
160 .alloc_len = sizeof(struct nftnl_expr_masq),
161 .max_attr = NFTA_MASQ_MAX,
162 .set = nftnl_expr_masq_set,
163 .get = nftnl_expr_masq_get,
164 .parse = nftnl_expr_masq_parse,
165 .build = nftnl_expr_masq_build,
166 .output = nftnl_expr_masq_snprintf,
167};