libnftnl 1.2.8
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, data_len);
38 break;
39 case NFTNL_EXPR_RANGE_OP:
40 memcpy(&range->op, data, data_len);
41 break;
42 case NFTNL_EXPR_RANGE_FROM_DATA:
43 return nftnl_data_cpy(&range->data_from, data, data_len);
44 case NFTNL_EXPR_RANGE_TO_DATA:
45 return nftnl_data_cpy(&range->data_to, data, data_len);
46 }
47 return 0;
48}
49
50static const void *nftnl_expr_range_get(const struct nftnl_expr *e,
51 uint16_t type, uint32_t *data_len)
52{
53 struct nftnl_expr_range *range = nftnl_expr_data(e);
54
55 switch(type) {
56 case NFTNL_EXPR_RANGE_SREG:
57 *data_len = sizeof(range->sreg);
58 return &range->sreg;
59 case NFTNL_EXPR_RANGE_OP:
60 *data_len = sizeof(range->op);
61 return &range->op;
62 case NFTNL_EXPR_RANGE_FROM_DATA:
63 *data_len = range->data_from.len;
64 return &range->data_from.val;
65 case NFTNL_EXPR_RANGE_TO_DATA:
66 *data_len = range->data_to.len;
67 return &range->data_to.val;
68 }
69 return NULL;
70}
71
72static int nftnl_expr_range_cb(const struct nlattr *attr, void *data)
73{
74 const struct nlattr **tb = data;
75 int type = mnl_attr_get_type(attr);
76
77 if (mnl_attr_type_valid(attr, NFTA_RANGE_MAX) < 0)
78 return MNL_CB_OK;
79
80 switch(type) {
81 case NFTA_RANGE_SREG:
82 case NFTA_RANGE_OP:
83 if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
84 abi_breakage();
85 break;
86 case NFTA_RANGE_FROM_DATA:
87 case NFTA_RANGE_TO_DATA:
88 if (mnl_attr_validate(attr, MNL_TYPE_BINARY) < 0)
89 abi_breakage();
90 break;
91 }
92
93 tb[type] = attr;
94 return MNL_CB_OK;
95}
96
97static void
98nftnl_expr_range_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
99{
100 struct nftnl_expr_range *range = nftnl_expr_data(e);
101
102 if (e->flags & (1 << NFTNL_EXPR_RANGE_SREG))
103 mnl_attr_put_u32(nlh, NFTA_RANGE_SREG, htonl(range->sreg));
104 if (e->flags & (1 << NFTNL_EXPR_RANGE_OP))
105 mnl_attr_put_u32(nlh, NFTA_RANGE_OP, htonl(range->op));
106 if (e->flags & (1 << NFTNL_EXPR_RANGE_FROM_DATA)) {
107 struct nlattr *nest;
108
109 nest = mnl_attr_nest_start(nlh, NFTA_RANGE_FROM_DATA);
110 mnl_attr_put(nlh, NFTA_DATA_VALUE, range->data_from.len,
111 range->data_from.val);
112 mnl_attr_nest_end(nlh, nest);
113 }
114 if (e->flags & (1 << NFTNL_EXPR_RANGE_TO_DATA)) {
115 struct nlattr *nest;
116
117 nest = mnl_attr_nest_start(nlh, NFTA_RANGE_TO_DATA);
118 mnl_attr_put(nlh, NFTA_DATA_VALUE, range->data_to.len,
119 range->data_to.val);
120 mnl_attr_nest_end(nlh, nest);
121 }
122}
123
124static int
125nftnl_expr_range_parse(struct nftnl_expr *e, struct nlattr *attr)
126{
127 struct nftnl_expr_range *range = nftnl_expr_data(e);
128 struct nlattr *tb[NFTA_RANGE_MAX+1] = {};
129 int ret = 0;
130
131 if (mnl_attr_parse_nested(attr, nftnl_expr_range_cb, tb) < 0)
132 return -1;
133
134 if (tb[NFTA_RANGE_SREG]) {
135 range->sreg = ntohl(mnl_attr_get_u32(tb[NFTA_RANGE_SREG]));
136 e->flags |= (1 << NFTA_RANGE_SREG);
137 }
138 if (tb[NFTA_RANGE_OP]) {
139 range->op = ntohl(mnl_attr_get_u32(tb[NFTA_RANGE_OP]));
140 e->flags |= (1 << NFTA_RANGE_OP);
141 }
142 if (tb[NFTA_RANGE_FROM_DATA]) {
143 ret = nftnl_parse_data(&range->data_from,
144 tb[NFTA_RANGE_FROM_DATA], NULL);
145 e->flags |= (1 << NFTA_RANGE_FROM_DATA);
146 }
147 if (tb[NFTA_RANGE_TO_DATA]) {
148 ret = nftnl_parse_data(&range->data_to,
149 tb[NFTA_RANGE_TO_DATA], NULL);
150 e->flags |= (1 << NFTA_RANGE_TO_DATA);
151 }
152
153 return ret;
154}
155
156static const char *expr_range_str[] = {
157 [NFT_RANGE_EQ] = "eq",
158 [NFT_RANGE_NEQ] = "neq",
159};
160
161static const char *range2str(uint32_t op)
162{
163 if (op > NFT_RANGE_NEQ)
164 return "unknown";
165
166 return expr_range_str[op];
167}
168
169static inline int nftnl_str2range(const char *op)
170{
171 if (strcmp(op, "eq") == 0)
172 return NFT_RANGE_EQ;
173 else if (strcmp(op, "neq") == 0)
174 return NFT_RANGE_NEQ;
175 else {
176 errno = EINVAL;
177 return -1;
178 }
179}
180
181static int nftnl_expr_range_snprintf(char *buf, size_t remain,
182 uint32_t flags, const struct nftnl_expr *e)
183{
184 struct nftnl_expr_range *range = nftnl_expr_data(e);
185 int offset = 0, ret;
186
187 ret = snprintf(buf, remain, "%s reg %u ",
188 range2str(range->op), range->sreg);
189 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
190
191 ret = nftnl_data_reg_snprintf(buf + offset, remain, &range->data_from,
192 0, DATA_VALUE);
193 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
194
195 ret = nftnl_data_reg_snprintf(buf + offset, remain, &range->data_to,
196 0, DATA_VALUE);
197 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
198
199 return offset;
200}
201
202static struct attr_policy range_attr_policy[__NFTNL_EXPR_RANGE_MAX] = {
203 [NFTNL_EXPR_RANGE_SREG] = { .maxlen = sizeof(uint32_t) },
204 [NFTNL_EXPR_RANGE_OP] = { .maxlen = sizeof(uint32_t) },
205 [NFTNL_EXPR_RANGE_FROM_DATA] = { .maxlen = NFT_DATA_VALUE_MAXLEN },
206 [NFTNL_EXPR_RANGE_TO_DATA] = { .maxlen = NFT_DATA_VALUE_MAXLEN },
207};
208
209struct expr_ops expr_ops_range = {
210 .name = "range",
211 .alloc_len = sizeof(struct nftnl_expr_range),
212 .nftnl_max_attr = __NFTNL_EXPR_RANGE_MAX - 1,
213 .attr_policy = range_attr_policy,
214 .set = nftnl_expr_range_set,
215 .get = nftnl_expr_range_get,
216 .parse = nftnl_expr_range_parse,
217 .build = nftnl_expr_range_build,
218 .output = nftnl_expr_range_snprintf,
219};