libnftnl 1.2.6
target.c
1/*
2 * (C) 2012 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 * This code has been sponsored by Sophos Astaro <http://www.sophos.com>
10 */
11
12#include "internal.h"
13
14#include <stdio.h>
15#include <stdint.h>
16#include <string.h> /* for memcpy */
17#include <arpa/inet.h>
18#include <errno.h>
19#include <libmnl/libmnl.h>
20
21#include <linux/netfilter/nf_tables.h>
22#include <linux/netfilter/nf_tables_compat.h>
23
24#include <libnftnl/expr.h>
25#include <libnftnl/rule.h>
26
27/* From include/linux/netfilter/x_tables.h */
28#define XT_EXTENSION_MAXNAMELEN 29
29
31 char name[XT_EXTENSION_MAXNAMELEN];
32 uint32_t rev;
33 uint32_t data_len;
34 const void *data;
35};
36
37static int
38nftnl_expr_target_set(struct nftnl_expr *e, uint16_t type,
39 const void *data, uint32_t data_len)
40{
41 struct nftnl_expr_target *tg = nftnl_expr_data(e);
42
43 switch(type) {
44 case NFTNL_EXPR_TG_NAME:
45 snprintf(tg->name, sizeof(tg->name), "%.*s", data_len,
46 (const char *) data);
47 break;
48 case NFTNL_EXPR_TG_REV:
49 memcpy(&tg->rev, data, sizeof(tg->rev));
50 break;
51 case NFTNL_EXPR_TG_INFO:
52 if (e->flags & (1 << NFTNL_EXPR_TG_INFO))
53 xfree(tg->data);
54
55 tg->data = data;
56 tg->data_len = data_len;
57 break;
58 default:
59 return -1;
60 }
61 return 0;
62}
63
64static const void *
65nftnl_expr_target_get(const struct nftnl_expr *e, uint16_t type,
66 uint32_t *data_len)
67{
68 struct nftnl_expr_target *tg = nftnl_expr_data(e);
69
70 switch(type) {
71 case NFTNL_EXPR_TG_NAME:
72 *data_len = sizeof(tg->name);
73 return tg->name;
74 case NFTNL_EXPR_TG_REV:
75 *data_len = sizeof(tg->rev);
76 return &tg->rev;
77 case NFTNL_EXPR_TG_INFO:
78 *data_len = tg->data_len;
79 return tg->data;
80 }
81 return NULL;
82}
83
84static int nftnl_expr_target_cb(const struct nlattr *attr, void *data)
85{
86 const struct nlattr **tb = data;
87 int type = mnl_attr_get_type(attr);
88
89 if (mnl_attr_type_valid(attr, NFTA_TARGET_MAX) < 0)
90 return MNL_CB_OK;
91
92 switch(type) {
93 case NFTA_TARGET_NAME:
94 if (mnl_attr_validate(attr, MNL_TYPE_NUL_STRING) < 0)
95 abi_breakage();
96 break;
97 case NFTA_TARGET_REV:
98 if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
99 abi_breakage();
100 break;
101 case NFTA_TARGET_INFO:
102 if (mnl_attr_validate(attr, MNL_TYPE_BINARY) < 0)
103 abi_breakage();
104 break;
105 }
106
107 tb[type] = attr;
108 return MNL_CB_OK;
109}
110
111static void
112nftnl_expr_target_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
113{
114 struct nftnl_expr_target *tg = nftnl_expr_data(e);
115
116 if (e->flags & (1 << NFTNL_EXPR_TG_NAME))
117 mnl_attr_put_strz(nlh, NFTA_TARGET_NAME, tg->name);
118 if (e->flags & (1 << NFTNL_EXPR_TG_REV))
119 mnl_attr_put_u32(nlh, NFTA_TARGET_REV, htonl(tg->rev));
120 if (e->flags & (1 << NFTNL_EXPR_TG_INFO))
121 mnl_attr_put(nlh, NFTA_TARGET_INFO, tg->data_len, tg->data);
122}
123
124static int nftnl_expr_target_parse(struct nftnl_expr *e, struct nlattr *attr)
125{
126 struct nftnl_expr_target *target = nftnl_expr_data(e);
127 struct nlattr *tb[NFTA_TARGET_MAX+1] = {};
128
129 if (mnl_attr_parse_nested(attr, nftnl_expr_target_cb, tb) < 0)
130 return -1;
131
132 if (tb[NFTA_TARGET_NAME]) {
133 snprintf(target->name, XT_EXTENSION_MAXNAMELEN, "%s",
134 mnl_attr_get_str(tb[NFTA_TARGET_NAME]));
135
136 target->name[XT_EXTENSION_MAXNAMELEN-1] = '\0';
137 e->flags |= (1 << NFTNL_EXPR_TG_NAME);
138 }
139
140 if (tb[NFTA_TARGET_REV]) {
141 target->rev = ntohl(mnl_attr_get_u32(tb[NFTA_TARGET_REV]));
142 e->flags |= (1 << NFTNL_EXPR_TG_REV);
143 }
144
145 if (tb[NFTA_TARGET_INFO]) {
146 uint32_t len = mnl_attr_get_payload_len(tb[NFTA_TARGET_INFO]);
147 void *target_data;
148
149 if (target->data)
150 xfree(target->data);
151
152 target_data = calloc(1, len);
153 if (target_data == NULL)
154 return -1;
155
156 memcpy(target_data, mnl_attr_get_payload(tb[NFTA_TARGET_INFO]), len);
157
158 target->data = target_data;
159 target->data_len = len;
160
161 e->flags |= (1 << NFTNL_EXPR_TG_INFO);
162 }
163
164 return 0;
165}
166
167static int
168nftnl_expr_target_snprintf(char *buf, size_t len,
169 uint32_t flags, const struct nftnl_expr *e)
170{
171 struct nftnl_expr_target *target = nftnl_expr_data(e);
172
173 return snprintf(buf, len, "name %s rev %u ", target->name, target->rev);
174}
175
176static void nftnl_expr_target_free(const struct nftnl_expr *e)
177{
178 struct nftnl_expr_target *target = nftnl_expr_data(e);
179
180 xfree(target->data);
181}
182
183struct expr_ops expr_ops_target = {
184 .name = "target",
185 .alloc_len = sizeof(struct nftnl_expr_target),
186 .max_attr = NFTA_TARGET_MAX,
187 .free = nftnl_expr_target_free,
188 .set = nftnl_expr_target_set,
189 .get = nftnl_expr_target_get,
190 .parse = nftnl_expr_target_parse,
191 .build = nftnl_expr_target_build,
192 .output = nftnl_expr_target_snprintf,
193};