libnftnl 1.2.9
byteorder.c
1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * (C) 2012-2013 by Pablo Neira Ayuso <pablo@netfilter.org>
4 *
5 * This code has been sponsored by Sophos Astaro <http://www.sophos.com>
6 */
7
8#include "internal.h"
9
10#include <stdio.h>
11#include <stdint.h>
12#include <string.h> /* for memcpy */
13#include <arpa/inet.h>
14#include <errno.h>
15#include <libmnl/libmnl.h>
16#include <linux/netfilter/nf_tables.h>
17#include <libnftnl/expr.h>
18#include <libnftnl/rule.h>
19
21 enum nft_registers sreg;
22 enum nft_registers dreg;
23 enum nft_byteorder_ops op;
24 unsigned int len;
25 unsigned int size;
26};
27
28static int
29nftnl_expr_byteorder_set(struct nftnl_expr *e, uint16_t type,
30 const void *data, uint32_t data_len)
31{
32 struct nftnl_expr_byteorder *byteorder = nftnl_expr_data(e);
33
34 switch(type) {
35 case NFTNL_EXPR_BYTEORDER_SREG:
36 memcpy(&byteorder->sreg, data, data_len);
37 break;
38 case NFTNL_EXPR_BYTEORDER_DREG:
39 memcpy(&byteorder->dreg, data, data_len);
40 break;
41 case NFTNL_EXPR_BYTEORDER_OP:
42 memcpy(&byteorder->op, data, data_len);
43 break;
44 case NFTNL_EXPR_BYTEORDER_LEN:
45 memcpy(&byteorder->len, data, data_len);
46 break;
47 case NFTNL_EXPR_BYTEORDER_SIZE:
48 memcpy(&byteorder->size, data, data_len);
49 break;
50 }
51 return 0;
52}
53
54static const void *
55nftnl_expr_byteorder_get(const struct nftnl_expr *e, uint16_t type,
56 uint32_t *data_len)
57{
58 struct nftnl_expr_byteorder *byteorder = nftnl_expr_data(e);
59
60 switch(type) {
61 case NFTNL_EXPR_BYTEORDER_SREG:
62 *data_len = sizeof(byteorder->sreg);
63 return &byteorder->sreg;
64 case NFTNL_EXPR_BYTEORDER_DREG:
65 *data_len = sizeof(byteorder->dreg);
66 return &byteorder->dreg;
67 case NFTNL_EXPR_BYTEORDER_OP:
68 *data_len = sizeof(byteorder->op);
69 return &byteorder->op;
70 case NFTNL_EXPR_BYTEORDER_LEN:
71 *data_len = sizeof(byteorder->len);
72 return &byteorder->len;
73 case NFTNL_EXPR_BYTEORDER_SIZE:
74 *data_len = sizeof(byteorder->size);
75 return &byteorder->size;
76 }
77 return NULL;
78}
79
80static int nftnl_expr_byteorder_cb(const struct nlattr *attr, void *data)
81{
82 const struct nlattr **tb = data;
83 int type = mnl_attr_get_type(attr);
84
85 if (mnl_attr_type_valid(attr, NFTA_BYTEORDER_MAX) < 0)
86 return MNL_CB_OK;
87
88 switch(type) {
89 case NFTA_BYTEORDER_SREG:
90 case NFTA_BYTEORDER_DREG:
91 case NFTA_BYTEORDER_OP:
92 case NFTA_BYTEORDER_LEN:
93 case NFTA_BYTEORDER_SIZE:
94 if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
95 abi_breakage();
96 break;
97 }
98
99 tb[type] = attr;
100 return MNL_CB_OK;
101}
102
103static void
104nftnl_expr_byteorder_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
105{
106 struct nftnl_expr_byteorder *byteorder = nftnl_expr_data(e);
107
108 if (e->flags & (1 << NFTNL_EXPR_BYTEORDER_SREG)) {
109 mnl_attr_put_u32(nlh, NFTA_BYTEORDER_SREG,
110 htonl(byteorder->sreg));
111 }
112 if (e->flags & (1 << NFTNL_EXPR_BYTEORDER_DREG)) {
113 mnl_attr_put_u32(nlh, NFTA_BYTEORDER_DREG,
114 htonl(byteorder->dreg));
115 }
116 if (e->flags & (1 << NFTNL_EXPR_BYTEORDER_OP)) {
117 mnl_attr_put_u32(nlh, NFTA_BYTEORDER_OP,
118 htonl(byteorder->op));
119 }
120 if (e->flags & (1 << NFTNL_EXPR_BYTEORDER_LEN)) {
121 mnl_attr_put_u32(nlh, NFTA_BYTEORDER_LEN,
122 htonl(byteorder->len));
123 }
124 if (e->flags & (1 << NFTNL_EXPR_BYTEORDER_SIZE)) {
125 mnl_attr_put_u32(nlh, NFTA_BYTEORDER_SIZE,
126 htonl(byteorder->size));
127 }
128}
129
130static int
131nftnl_expr_byteorder_parse(struct nftnl_expr *e, struct nlattr *attr)
132{
133 struct nftnl_expr_byteorder *byteorder = nftnl_expr_data(e);
134 struct nlattr *tb[NFTA_BYTEORDER_MAX+1] = {};
135 int ret = 0;
136
137 if (mnl_attr_parse_nested(attr, nftnl_expr_byteorder_cb, tb) < 0)
138 return -1;
139
140 if (tb[NFTA_BYTEORDER_SREG]) {
141 byteorder->sreg =
142 ntohl(mnl_attr_get_u32(tb[NFTA_BYTEORDER_SREG]));
143 e->flags |= (1 << NFTNL_EXPR_BYTEORDER_SREG);
144 }
145 if (tb[NFTA_BYTEORDER_DREG]) {
146 byteorder->dreg =
147 ntohl(mnl_attr_get_u32(tb[NFTA_BYTEORDER_DREG]));
148 e->flags |= (1 << NFTNL_EXPR_BYTEORDER_DREG);
149 }
150 if (tb[NFTA_BYTEORDER_OP]) {
151 byteorder->op =
152 ntohl(mnl_attr_get_u32(tb[NFTA_BYTEORDER_OP]));
153 e->flags |= (1 << NFTNL_EXPR_BYTEORDER_OP);
154 }
155 if (tb[NFTA_BYTEORDER_LEN]) {
156 byteorder->len =
157 ntohl(mnl_attr_get_u32(tb[NFTA_BYTEORDER_LEN]));
158 e->flags |= (1 << NFTNL_EXPR_BYTEORDER_LEN);
159 }
160 if (tb[NFTA_BYTEORDER_SIZE]) {
161 byteorder->size =
162 ntohl(mnl_attr_get_u32(tb[NFTA_BYTEORDER_SIZE]));
163 e->flags |= (1 << NFTNL_EXPR_BYTEORDER_SIZE);
164 }
165
166 return ret;
167}
168
169static const char *expr_byteorder_str[] = {
170 [NFT_BYTEORDER_HTON] = "hton",
171 [NFT_BYTEORDER_NTOH] = "ntoh",
172};
173
174static const char *bo2str(uint32_t type)
175{
176 if (type > NFT_BYTEORDER_HTON)
177 return "unknown";
178
179 return expr_byteorder_str[type];
180}
181
182static int
183nftnl_expr_byteorder_snprintf(char *buf, size_t remain,
184 uint32_t flags, const struct nftnl_expr *e)
185{
186 struct nftnl_expr_byteorder *byteorder = nftnl_expr_data(e);
187 int offset = 0, ret;
188
189 ret = snprintf(buf, remain, "reg %u = %s(reg %u, %u, %u) ",
190 byteorder->dreg, bo2str(byteorder->op),
191 byteorder->sreg, byteorder->size, byteorder->len);
192 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
193
194 return offset;
195}
196
197static struct attr_policy byteorder_attr_policy[__NFTNL_EXPR_BYTEORDER_MAX] = {
198 [NFTNL_EXPR_BYTEORDER_DREG] = { .maxlen = sizeof(uint32_t) },
199 [NFTNL_EXPR_BYTEORDER_SREG] = { .maxlen = sizeof(uint32_t) },
200 [NFTNL_EXPR_BYTEORDER_OP] = { .maxlen = sizeof(uint32_t) },
201 [NFTNL_EXPR_BYTEORDER_LEN] = { .maxlen = sizeof(uint32_t) },
202 [NFTNL_EXPR_BYTEORDER_SIZE] = { .maxlen = sizeof(uint32_t) },
203};
204
205struct expr_ops expr_ops_byteorder = {
206 .name = "byteorder",
207 .alloc_len = sizeof(struct nftnl_expr_byteorder),
208 .nftnl_max_attr = __NFTNL_EXPR_BYTEORDER_MAX - 1,
209 .attr_policy = byteorder_attr_policy,
210 .set = nftnl_expr_byteorder_set,
211 .get = nftnl_expr_byteorder_get,
212 .parse = nftnl_expr_byteorder_parse,
213 .build = nftnl_expr_byteorder_build,
214 .output = nftnl_expr_byteorder_snprintf,
215};