libnftnl 1.2.7
log.c
1/*
2 * (C) 2012-2013 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 <stdio.h>
13#include <stdint.h>
14#include <string.h>
15#include <arpa/inet.h>
16#include <errno.h>
17#include <linux/netfilter/nf_tables.h>
18#include <linux/netfilter/nf_log.h>
19
20#include "internal.h"
21#include <libmnl/libmnl.h>
22#include <libnftnl/expr.h>
23#include <libnftnl/rule.h>
24
26 uint32_t snaplen;
27 uint16_t group;
28 uint16_t qthreshold;
29 uint32_t level;
30 uint32_t flags;
31 const char *prefix;
32};
33
34static int nftnl_expr_log_set(struct nftnl_expr *e, uint16_t type,
35 const void *data, uint32_t data_len)
36{
37 struct nftnl_expr_log *log = nftnl_expr_data(e);
38
39 switch(type) {
40 case NFTNL_EXPR_LOG_PREFIX:
41 if (log->flags & (1 << NFTNL_EXPR_LOG_PREFIX))
42 xfree(log->prefix);
43
44 log->prefix = strdup(data);
45 if (!log->prefix)
46 return -1;
47 break;
48 case NFTNL_EXPR_LOG_GROUP:
49 memcpy(&log->group, data, data_len);
50 break;
51 case NFTNL_EXPR_LOG_SNAPLEN:
52 memcpy(&log->snaplen, data, data_len);
53 break;
54 case NFTNL_EXPR_LOG_QTHRESHOLD:
55 memcpy(&log->qthreshold, data, data_len);
56 break;
57 case NFTNL_EXPR_LOG_LEVEL:
58 memcpy(&log->level, data, data_len);
59 break;
60 case NFTNL_EXPR_LOG_FLAGS:
61 memcpy(&log->flags, data, data_len);
62 break;
63 }
64 return 0;
65}
66
67static const void *
68nftnl_expr_log_get(const struct nftnl_expr *e, uint16_t type,
69 uint32_t *data_len)
70{
71 struct nftnl_expr_log *log = nftnl_expr_data(e);
72
73 switch(type) {
74 case NFTNL_EXPR_LOG_PREFIX:
75 *data_len = strlen(log->prefix)+1;
76 return log->prefix;
77 case NFTNL_EXPR_LOG_GROUP:
78 *data_len = sizeof(log->group);
79 return &log->group;
80 case NFTNL_EXPR_LOG_SNAPLEN:
81 *data_len = sizeof(log->snaplen);
82 return &log->snaplen;
83 case NFTNL_EXPR_LOG_QTHRESHOLD:
84 *data_len = sizeof(log->qthreshold);
85 return &log->qthreshold;
86 case NFTNL_EXPR_LOG_LEVEL:
87 *data_len = sizeof(log->level);
88 return &log->level;
89 case NFTNL_EXPR_LOG_FLAGS:
90 *data_len = sizeof(log->flags);
91 return &log->flags;
92 }
93 return NULL;
94}
95
96static int nftnl_expr_log_cb(const struct nlattr *attr, void *data)
97{
98 const struct nlattr **tb = data;
99 int type = mnl_attr_get_type(attr);
100
101 if (mnl_attr_type_valid(attr, NFTA_LOG_MAX) < 0)
102 return MNL_CB_OK;
103
104 switch(type) {
105 case NFTA_LOG_PREFIX:
106 if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0)
107 abi_breakage();
108 break;
109 case NFTA_LOG_GROUP:
110 case NFTA_LOG_QTHRESHOLD:
111 if (mnl_attr_validate(attr, MNL_TYPE_U16) < 0)
112 abi_breakage();
113 break;
114 case NFTA_LOG_SNAPLEN:
115 case NFTA_LOG_LEVEL:
116 case NFTA_LOG_FLAGS:
117 if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
118 abi_breakage();
119 break;
120 }
121
122 tb[type] = attr;
123 return MNL_CB_OK;
124}
125
126static void
127nftnl_expr_log_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
128{
129 struct nftnl_expr_log *log = nftnl_expr_data(e);
130
131 if (e->flags & (1 << NFTNL_EXPR_LOG_PREFIX))
132 mnl_attr_put_strz(nlh, NFTA_LOG_PREFIX, log->prefix);
133 if (e->flags & (1 << NFTNL_EXPR_LOG_GROUP))
134 mnl_attr_put_u16(nlh, NFTA_LOG_GROUP, htons(log->group));
135 if (e->flags & (1 << NFTNL_EXPR_LOG_SNAPLEN))
136 mnl_attr_put_u32(nlh, NFTA_LOG_SNAPLEN, htonl(log->snaplen));
137 if (e->flags & (1 << NFTNL_EXPR_LOG_QTHRESHOLD))
138 mnl_attr_put_u16(nlh, NFTA_LOG_QTHRESHOLD, htons(log->qthreshold));
139 if (e->flags & (1 << NFTNL_EXPR_LOG_LEVEL))
140 mnl_attr_put_u32(nlh, NFTA_LOG_LEVEL, htonl(log->level));
141 if (e->flags & (1 << NFTNL_EXPR_LOG_FLAGS))
142 mnl_attr_put_u32(nlh, NFTA_LOG_FLAGS, htonl(log->flags));
143}
144
145static int
146nftnl_expr_log_parse(struct nftnl_expr *e, struct nlattr *attr)
147{
148 struct nftnl_expr_log *log = nftnl_expr_data(e);
149 struct nlattr *tb[NFTA_LOG_MAX+1] = {};
150
151 if (mnl_attr_parse_nested(attr, nftnl_expr_log_cb, tb) < 0)
152 return -1;
153
154 if (tb[NFTA_LOG_PREFIX]) {
155 if (log->prefix)
156 xfree(log->prefix);
157
158 log->prefix = strdup(mnl_attr_get_str(tb[NFTA_LOG_PREFIX]));
159 if (!log->prefix)
160 return -1;
161 e->flags |= (1 << NFTNL_EXPR_LOG_PREFIX);
162 }
163 if (tb[NFTA_LOG_GROUP]) {
164 log->group = ntohs(mnl_attr_get_u16(tb[NFTA_LOG_GROUP]));
165 e->flags |= (1 << NFTNL_EXPR_LOG_GROUP);
166 }
167 if (tb[NFTA_LOG_SNAPLEN]) {
168 log->snaplen = ntohl(mnl_attr_get_u32(tb[NFTA_LOG_SNAPLEN]));
169 e->flags |= (1 << NFTNL_EXPR_LOG_SNAPLEN);
170 }
171 if (tb[NFTA_LOG_QTHRESHOLD]) {
172 log->qthreshold = ntohs(mnl_attr_get_u16(tb[NFTA_LOG_QTHRESHOLD]));
173 e->flags |= (1 << NFTNL_EXPR_LOG_QTHRESHOLD);
174 }
175 if (tb[NFTA_LOG_LEVEL]) {
176 log->level = ntohl(mnl_attr_get_u32(tb[NFTA_LOG_LEVEL]));
177 e->flags |= (1 << NFTNL_EXPR_LOG_LEVEL);
178 }
179 if (tb[NFTA_LOG_FLAGS]) {
180 log->flags = ntohl(mnl_attr_get_u32(tb[NFTA_LOG_FLAGS]));
181 e->flags |= (1 << NFTNL_EXPR_LOG_FLAGS);
182 }
183
184 return 0;
185}
186
187static int
188nftnl_expr_log_snprintf(char *buf, size_t remain,
189 uint32_t flags, const struct nftnl_expr *e)
190{
191 struct nftnl_expr_log *log = nftnl_expr_data(e);
192 int ret, offset = 0;
193
194 if (e->flags & (1 << NFTNL_EXPR_LOG_PREFIX)) {
195 ret = snprintf(buf, remain, "prefix %s ", log->prefix);
196 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
197 }
198
199 if (e->flags & (1 << NFTNL_EXPR_LOG_GROUP)) {
200 ret = snprintf(buf + offset, remain,
201 "group %u snaplen %u qthreshold %u ",
202 log->group, log->snaplen, log->qthreshold);
203 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
204 } else {
205 if (e->flags & (1 << NFTNL_EXPR_LOG_LEVEL)) {
206 ret = snprintf(buf + offset, remain, "level %u ",
207 log->level);
208 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
209 }
210 if (e->flags & (1 << NFTNL_EXPR_LOG_FLAGS)) {
211 if (log->flags & NF_LOG_TCPSEQ) {
212 ret = snprintf(buf + offset, remain, "tcpseq ");
213 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
214 }
215 if (log->flags & NF_LOG_TCPOPT) {
216 ret = snprintf(buf + offset, remain, "tcpopt ");
217 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
218 }
219 if (log->flags & NF_LOG_IPOPT) {
220 ret = snprintf(buf + offset, remain, "ipopt ");
221 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
222 }
223 if (log->flags & NF_LOG_UID) {
224 ret = snprintf(buf + offset, remain, "uid ");
225 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
226 }
227 if (log->flags & NF_LOG_MACDECODE) {
228 ret = snprintf(buf + offset, remain,
229 "macdecode ");
230 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
231 }
232 }
233 }
234
235 return offset;
236}
237
238static void nftnl_expr_log_free(const struct nftnl_expr *e)
239{
240 struct nftnl_expr_log *log = nftnl_expr_data(e);
241
242 xfree(log->prefix);
243}
244
245static struct attr_policy log_attr_policy[__NFTNL_EXPR_LOG_MAX] = {
246 [NFTNL_EXPR_LOG_PREFIX] = { .maxlen = NF_LOG_PREFIXLEN },
247 [NFTNL_EXPR_LOG_GROUP] = { .maxlen = sizeof(uint16_t) },
248 [NFTNL_EXPR_LOG_SNAPLEN] = { .maxlen = sizeof(uint32_t) },
249 [NFTNL_EXPR_LOG_QTHRESHOLD] = { .maxlen = sizeof(uint16_t) },
250 [NFTNL_EXPR_LOG_LEVEL] = { .maxlen = sizeof(uint32_t) },
251 [NFTNL_EXPR_LOG_FLAGS] = { .maxlen = sizeof(uint32_t) },
252};
253
254struct expr_ops expr_ops_log = {
255 .name = "log",
256 .alloc_len = sizeof(struct nftnl_expr_log),
257 .nftnl_max_attr = __NFTNL_EXPR_LOG_MAX - 1,
258 .attr_policy = log_attr_policy,
259 .free = nftnl_expr_log_free,
260 .set = nftnl_expr_log_set,
261 .get = nftnl_expr_log_get,
262 .parse = nftnl_expr_log_parse,
263 .build = nftnl_expr_log_build,
264 .output = nftnl_expr_log_snprintf,
265};