libnftnl 1.2.6
range.c
1/*
2 * (C) 2016 by Pablo Neira Ayuso <pablo@netfilter.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 "internal.h"
11
12#include <stdio.h>
13#include <stdint.h>
14#include <string.h>
15#include <arpa/inet.h>
16#include <errno.h>
17
18#include <libmnl/libmnl.h>
19#include <linux/netfilter/nf_tables.h>
20#include <libnftnl/expr.h>
21#include <libnftnl/rule.h>
22
24 union nftnl_data_reg data_from;
25 union nftnl_data_reg data_to;
26 enum nft_registers sreg;
27 enum nft_range_ops op;
28};
29
30static int nftnl_expr_range_set(struct nftnl_expr *e, uint16_t type,
31 const void *data, uint32_t data_len)
32{
33 struct nftnl_expr_range *range = nftnl_expr_data(e);
34
35 switch(type) {
36 case NFTNL_EXPR_RANGE_SREG:
37 memcpy(&range->sreg, data, sizeof(range->sreg));
38 break;
39 case NFTNL_EXPR_RANGE_OP:
40 memcpy(&range->op, data, sizeof(range->op));
41 break;
42 case NFTNL_EXPR_RANGE_FROM_DATA:
43 memcpy(&range->data_from.val, data, data_len);
44 range->data_from.len = data_len;
45 break;
46 case NFTNL_EXPR_RANGE_TO_DATA:
47 memcpy(&range->data_to.val, data, data_len);
48 range->data_to.len = data_len;
49 break;
50 default:
51 return -1;
52 }
53 return 0;
54}
55
56static const void *nftnl_expr_range_get(const struct nftnl_expr *e,
57 uint16_t type, uint32_t *data_len)
58{
59 struct nftnl_expr_range *range = nftnl_expr_data(e);
60
61 switch(type) {
62 case NFTNL_EXPR_RANGE_SREG:
63 *data_len = sizeof(range->sreg);
64 return &range->sreg;
65 case NFTNL_EXPR_RANGE_OP:
66 *data_len = sizeof(range->op);
67 return &range->op;
68 case NFTNL_EXPR_RANGE_FROM_DATA:
69 *data_len = range->data_from.len;
70 return &range->data_from.val;
71 case NFTNL_EXPR_RANGE_TO_DATA:
72 *data_len = range->data_to.len;
73 return &range->data_to.val;
74 }
75 return NULL;
76}
77
78static int nftnl_expr_range_cb(const struct nlattr *attr, void *data)
79{
80 const struct nlattr **tb = data;
81 int type = mnl_attr_get_type(attr);
82
83 if (mnl_attr_type_valid(attr, NFTA_RANGE_MAX) < 0)
84 return MNL_CB_OK;
85
86 switch(type) {
87 case NFTA_RANGE_SREG:
88 case NFTA_RANGE_OP:
89 if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
90 abi_breakage();
91 break;
92 case NFTA_RANGE_FROM_DATA:
93 case NFTA_RANGE_TO_DATA:
94 if (mnl_attr_validate(attr, MNL_TYPE_BINARY) < 0)
95 abi_breakage();
96 break;
97 }
98
99 tb[type] = attr;
100 return MNL_CB_OK;
101}
102
103static void
104nftnl_expr_range_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
105{
106 struct nftnl_expr_range *range = nftnl_expr_data(e);
107
108 if (e->flags & (1 << NFTNL_EXPR_RANGE_SREG))
109 mnl_attr_put_u32(nlh, NFTA_RANGE_SREG, htonl(range->sreg));
110 if (e->flags & (1 << NFTNL_EXPR_RANGE_OP))
111 mnl_attr_put_u32(nlh, NFTA_RANGE_OP, htonl(range->op));
112 if (e->flags & (1 << NFTNL_EXPR_RANGE_FROM_DATA)) {
113 struct nlattr *nest;
114
115 nest = mnl_attr_nest_start(nlh, NFTA_RANGE_FROM_DATA);
116 mnl_attr_put(nlh, NFTA_DATA_VALUE, range->data_from.len,
117 range->data_from.val);
118 mnl_attr_nest_end(nlh, nest);
119 }
120 if (e->flags & (1 << NFTNL_EXPR_RANGE_TO_DATA)) {
121 struct nlattr *nest;
122
123 nest = mnl_attr_nest_start(nlh, NFTA_RANGE_TO_DATA);
124 mnl_attr_put(nlh, NFTA_DATA_VALUE, range->data_to.len,
125 range->data_to.val);
126 mnl_attr_nest_end(nlh, nest);
127 }
128}
129
130static int
131nftnl_expr_range_parse(struct nftnl_expr *e, struct nlattr *attr)
132{
133 struct nftnl_expr_range *range = nftnl_expr_data(e);
134 struct nlattr *tb[NFTA_RANGE_MAX+1] = {};
135 int ret = 0;
136
137 if (mnl_attr_parse_nested(attr, nftnl_expr_range_cb, tb) < 0)
138 return -1;
139
140 if (tb[NFTA_RANGE_SREG]) {
141 range->sreg = ntohl(mnl_attr_get_u32(tb[NFTA_RANGE_SREG]));
142 e->flags |= (1 << NFTA_RANGE_SREG);
143 }
144 if (tb[NFTA_RANGE_OP]) {
145 range->op = ntohl(mnl_attr_get_u32(tb[NFTA_RANGE_OP]));
146 e->flags |= (1 << NFTA_RANGE_OP);
147 }
148 if (tb[NFTA_RANGE_FROM_DATA]) {
149 ret = nftnl_parse_data(&range->data_from,
150 tb[NFTA_RANGE_FROM_DATA], NULL);
151 e->flags |= (1 << NFTA_RANGE_FROM_DATA);
152 }
153 if (tb[NFTA_RANGE_TO_DATA]) {
154 ret = nftnl_parse_data(&range->data_to,
155 tb[NFTA_RANGE_TO_DATA], NULL);
156 e->flags |= (1 << NFTA_RANGE_TO_DATA);
157 }
158
159 return ret;
160}
161
162static const char *expr_range_str[] = {
163 [NFT_RANGE_EQ] = "eq",
164 [NFT_RANGE_NEQ] = "neq",
165};
166
167static const char *range2str(uint32_t op)
168{
169 if (op > NFT_RANGE_NEQ)
170 return "unknown";
171
172 return expr_range_str[op];
173}
174
175static inline int nftnl_str2range(const char *op)
176{
177 if (strcmp(op, "eq") == 0)
178 return NFT_RANGE_EQ;
179 else if (strcmp(op, "neq") == 0)
180 return NFT_RANGE_NEQ;
181 else {
182 errno = EINVAL;
183 return -1;
184 }
185}
186
187static int nftnl_expr_range_snprintf(char *buf, size_t remain,
188 uint32_t flags, const struct nftnl_expr *e)
189{
190 struct nftnl_expr_range *range = nftnl_expr_data(e);
191 int offset = 0, ret;
192
193 ret = snprintf(buf, remain, "%s reg %u ",
194 range2str(range->op), range->sreg);
195 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
196
197 ret = nftnl_data_reg_snprintf(buf + offset, remain, &range->data_from,
198 0, DATA_VALUE);
199 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
200
201 ret = nftnl_data_reg_snprintf(buf + offset, remain, &range->data_to,
202 0, DATA_VALUE);
203 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
204
205 return offset;
206}
207
208struct expr_ops expr_ops_range = {
209 .name = "range",
210 .alloc_len = sizeof(struct nftnl_expr_range),
211 .max_attr = NFTA_RANGE_MAX,
212 .set = nftnl_expr_range_set,
213 .get = nftnl_expr_range_get,
214 .parse = nftnl_expr_range_parse,
215 .build = nftnl_expr_range_build,
216 .output = nftnl_expr_range_snprintf,
217};