libnftnl 1.2.9
masq.c
1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * (C) 2014 by Arturo Borrero Gonzalez <arturo@debian.org>
4 */
5
6#include <stdio.h>
7#include <stdint.h>
8#include <arpa/inet.h>
9#include <errno.h>
10#include <inttypes.h>
11
12#include <linux/netfilter/nf_tables.h>
13
14#include "internal.h"
15#include <libmnl/libmnl.h>
16#include <libnftnl/expr.h>
17#include <libnftnl/rule.h>
18
20 uint32_t flags;
21 enum nft_registers sreg_proto_min;
22 enum nft_registers sreg_proto_max;
23};
24
25static int
26nftnl_expr_masq_set(struct nftnl_expr *e, uint16_t type,
27 const void *data, uint32_t data_len)
28{
29 struct nftnl_expr_masq *masq = nftnl_expr_data(e);
30
31 switch (type) {
32 case NFTNL_EXPR_MASQ_FLAGS:
33 memcpy(&masq->flags, data, data_len);
34 break;
35 case NFTNL_EXPR_MASQ_REG_PROTO_MIN:
36 memcpy(&masq->sreg_proto_min, data, data_len);
37 break;
38 case NFTNL_EXPR_MASQ_REG_PROTO_MAX:
39 memcpy(&masq->sreg_proto_max, data, data_len);
40 break;
41 }
42 return 0;
43}
44
45static const void *
46nftnl_expr_masq_get(const struct nftnl_expr *e, uint16_t type,
47 uint32_t *data_len)
48{
49 struct nftnl_expr_masq *masq = nftnl_expr_data(e);
50
51 switch (type) {
52 case NFTNL_EXPR_MASQ_FLAGS:
53 *data_len = sizeof(masq->flags);
54 return &masq->flags;
55 case NFTNL_EXPR_MASQ_REG_PROTO_MIN:
56 *data_len = sizeof(masq->sreg_proto_min);
57 return &masq->sreg_proto_min;
58 case NFTNL_EXPR_MASQ_REG_PROTO_MAX:
59 *data_len = sizeof(masq->sreg_proto_max);
60 return &masq->sreg_proto_max;
61 }
62 return NULL;
63}
64
65static int nftnl_expr_masq_cb(const struct nlattr *attr, void *data)
66{
67 const struct nlattr **tb = data;
68 int type = mnl_attr_get_type(attr);
69
70 if (mnl_attr_type_valid(attr, NFTA_MASQ_MAX) < 0)
71 return MNL_CB_OK;
72
73 switch (type) {
74 case NFTA_MASQ_REG_PROTO_MIN:
75 case NFTA_MASQ_REG_PROTO_MAX:
76 case NFTA_MASQ_FLAGS:
77 if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
78 abi_breakage();
79 break;
80 }
81
82 tb[type] = attr;
83 return MNL_CB_OK;
84}
85
86static void
87nftnl_expr_masq_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
88{
89 struct nftnl_expr_masq *masq = nftnl_expr_data(e);
90
91 if (e->flags & (1 << NFTNL_EXPR_MASQ_FLAGS))
92 mnl_attr_put_u32(nlh, NFTA_MASQ_FLAGS, htobe32(masq->flags));
93 if (e->flags & (1 << NFTNL_EXPR_MASQ_REG_PROTO_MIN))
94 mnl_attr_put_u32(nlh, NFTA_MASQ_REG_PROTO_MIN,
95 htobe32(masq->sreg_proto_min));
96 if (e->flags & (1 << NFTNL_EXPR_MASQ_REG_PROTO_MAX))
97 mnl_attr_put_u32(nlh, NFTA_MASQ_REG_PROTO_MAX,
98 htobe32(masq->sreg_proto_max));
99}
100
101static int
102nftnl_expr_masq_parse(struct nftnl_expr *e, struct nlattr *attr)
103{
104 struct nftnl_expr_masq *masq = nftnl_expr_data(e);
105 struct nlattr *tb[NFTA_MASQ_MAX+1] = {};
106
107 if (mnl_attr_parse_nested(attr, nftnl_expr_masq_cb, tb) < 0)
108 return -1;
109
110 if (tb[NFTA_MASQ_FLAGS]) {
111 masq->flags = be32toh(mnl_attr_get_u32(tb[NFTA_MASQ_FLAGS]));
112 e->flags |= (1 << NFTNL_EXPR_MASQ_FLAGS);
113 }
114 if (tb[NFTA_MASQ_REG_PROTO_MIN]) {
115 masq->sreg_proto_min =
116 be32toh(mnl_attr_get_u32(tb[NFTA_MASQ_REG_PROTO_MIN]));
117 e->flags |= (1 << NFTNL_EXPR_MASQ_REG_PROTO_MIN);
118 }
119 if (tb[NFTA_MASQ_REG_PROTO_MAX]) {
120 masq->sreg_proto_max =
121 be32toh(mnl_attr_get_u32(tb[NFTA_MASQ_REG_PROTO_MAX]));
122 e->flags |= (1 << NFTNL_EXPR_MASQ_REG_PROTO_MAX);
123 }
124
125 return 0;
126}
127
128static int nftnl_expr_masq_snprintf(char *buf, size_t remain,
129 uint32_t flags, const struct nftnl_expr *e)
130{
131 struct nftnl_expr_masq *masq = nftnl_expr_data(e);
132 int offset = 0, ret = 0;
133
134 if (e->flags & (1 << NFTNL_EXPR_MASQ_REG_PROTO_MIN)) {
135 ret = snprintf(buf + offset, remain, "proto_min reg %u ",
136 masq->sreg_proto_min);
137 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
138 }
139 if (e->flags & (1 << NFTNL_EXPR_MASQ_REG_PROTO_MAX)) {
140 ret = snprintf(buf + offset, remain, "proto_max reg %u ",
141 masq->sreg_proto_max);
142 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
143 }
144 if (e->flags & (1 << NFTNL_EXPR_MASQ_FLAGS)) {
145 ret = snprintf(buf + offset, remain, "flags 0x%x ", masq->flags);
146 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
147 }
148
149 return offset;
150}
151
152static struct attr_policy masq_attr_policy[__NFTNL_EXPR_MASQ_MAX] = {
153 [NFTNL_EXPR_MASQ_FLAGS] = { .maxlen = sizeof(uint32_t) },
154 [NFTNL_EXPR_MASQ_REG_PROTO_MIN] = { .maxlen = sizeof(uint32_t) },
155 [NFTNL_EXPR_MASQ_REG_PROTO_MAX] = { .maxlen = sizeof(uint32_t) },
156};
157
158struct expr_ops expr_ops_masq = {
159 .name = "masq",
160 .alloc_len = sizeof(struct nftnl_expr_masq),
161 .nftnl_max_attr = __NFTNL_EXPR_MASQ_MAX - 1,
162 .attr_policy = masq_attr_policy,
163 .set = nftnl_expr_masq_set,
164 .get = nftnl_expr_masq_get,
165 .parse = nftnl_expr_masq_parse,
166 .build = nftnl_expr_masq_build,
167 .output = nftnl_expr_masq_snprintf,
168};