libnftnl 1.3.1
log.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 <stdio.h>
9#include <stdint.h>
10#include <string.h>
11#include <arpa/inet.h>
12#include <errno.h>
13#include <linux/netfilter/nf_tables.h>
14#include <linux/netfilter/nf_log.h>
15
16#include "internal.h"
17#include <libmnl/libmnl.h>
18#include <libnftnl/expr.h>
19#include <libnftnl/rule.h>
20
21struct nftnl_expr_log {
22 uint32_t snaplen;
23 uint16_t group;
24 uint16_t qthreshold;
25 uint32_t level;
26 uint32_t flags;
27 const char *prefix;
28};
29
30static int nftnl_expr_log_set(struct nftnl_expr *e, uint16_t type,
31 const void *data, uint32_t data_len)
32{
33 struct nftnl_expr_log *log = nftnl_expr_data(e);
34
35 switch(type) {
36 case NFTNL_EXPR_LOG_PREFIX:
37 if (log->flags & (1 << NFTNL_EXPR_LOG_PREFIX))
38 xfree(log->prefix);
39
40 log->prefix = strdup(data);
41 if (!log->prefix)
42 return -1;
43 break;
44 case NFTNL_EXPR_LOG_GROUP:
45 memcpy(&log->group, data, data_len);
46 break;
47 case NFTNL_EXPR_LOG_SNAPLEN:
48 memcpy(&log->snaplen, data, data_len);
49 break;
50 case NFTNL_EXPR_LOG_QTHRESHOLD:
51 memcpy(&log->qthreshold, data, data_len);
52 break;
53 case NFTNL_EXPR_LOG_LEVEL:
54 memcpy(&log->level, data, data_len);
55 break;
56 case NFTNL_EXPR_LOG_FLAGS:
57 memcpy(&log->flags, data, data_len);
58 break;
59 }
60 return 0;
61}
62
63static const void *
64nftnl_expr_log_get(const struct nftnl_expr *e, uint16_t type,
65 uint32_t *data_len)
66{
67 struct nftnl_expr_log *log = nftnl_expr_data(e);
68
69 switch(type) {
70 case NFTNL_EXPR_LOG_PREFIX:
71 *data_len = strlen(log->prefix)+1;
72 return log->prefix;
73 case NFTNL_EXPR_LOG_GROUP:
74 *data_len = sizeof(log->group);
75 return &log->group;
76 case NFTNL_EXPR_LOG_SNAPLEN:
77 *data_len = sizeof(log->snaplen);
78 return &log->snaplen;
79 case NFTNL_EXPR_LOG_QTHRESHOLD:
80 *data_len = sizeof(log->qthreshold);
81 return &log->qthreshold;
82 case NFTNL_EXPR_LOG_LEVEL:
83 *data_len = sizeof(log->level);
84 return &log->level;
85 case NFTNL_EXPR_LOG_FLAGS:
86 *data_len = sizeof(log->flags);
87 return &log->flags;
88 }
89 return NULL;
90}
91
92static int nftnl_expr_log_cb(const struct nlattr *attr, void *data)
93{
94 const struct nlattr **tb = data;
95 int type = mnl_attr_get_type(attr);
96
97 if (mnl_attr_type_valid(attr, NFTA_LOG_MAX) < 0)
98 return MNL_CB_OK;
99
100 switch(type) {
101 case NFTA_LOG_PREFIX:
102 if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0)
103 abi_breakage();
104 break;
105 case NFTA_LOG_GROUP:
106 case NFTA_LOG_QTHRESHOLD:
107 if (mnl_attr_validate(attr, MNL_TYPE_U16) < 0)
108 abi_breakage();
109 break;
110 case NFTA_LOG_SNAPLEN:
111 case NFTA_LOG_LEVEL:
112 case NFTA_LOG_FLAGS:
113 if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
114 abi_breakage();
115 break;
116 }
117
118 tb[type] = attr;
119 return MNL_CB_OK;
120}
121
122static void
123nftnl_expr_log_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
124{
125 struct nftnl_expr_log *log = nftnl_expr_data(e);
126
127 if (e->flags & (1 << NFTNL_EXPR_LOG_PREFIX))
128 mnl_attr_put_strz(nlh, NFTA_LOG_PREFIX, log->prefix);
129 if (e->flags & (1 << NFTNL_EXPR_LOG_GROUP))
130 mnl_attr_put_u16(nlh, NFTA_LOG_GROUP, htons(log->group));
131 if (e->flags & (1 << NFTNL_EXPR_LOG_SNAPLEN))
132 mnl_attr_put_u32(nlh, NFTA_LOG_SNAPLEN, htonl(log->snaplen));
133 if (e->flags & (1 << NFTNL_EXPR_LOG_QTHRESHOLD))
134 mnl_attr_put_u16(nlh, NFTA_LOG_QTHRESHOLD, htons(log->qthreshold));
135 if (e->flags & (1 << NFTNL_EXPR_LOG_LEVEL))
136 mnl_attr_put_u32(nlh, NFTA_LOG_LEVEL, htonl(log->level));
137 if (e->flags & (1 << NFTNL_EXPR_LOG_FLAGS))
138 mnl_attr_put_u32(nlh, NFTA_LOG_FLAGS, htonl(log->flags));
139}
140
141static int
142nftnl_expr_log_parse(struct nftnl_expr *e, struct nlattr *attr)
143{
144 struct nftnl_expr_log *log = nftnl_expr_data(e);
145 struct nlattr *tb[NFTA_LOG_MAX+1] = {};
146
147 if (mnl_attr_parse_nested(attr, nftnl_expr_log_cb, tb) < 0)
148 return -1;
149
150 if (nftnl_parse_str_attr(tb[NFTA_LOG_PREFIX],
151 NFTNL_EXPR_LOG_PREFIX,
152 &log->prefix, &e->flags) < 0)
153 return -1;
154 if (tb[NFTA_LOG_GROUP]) {
155 log->group = ntohs(mnl_attr_get_u16(tb[NFTA_LOG_GROUP]));
156 e->flags |= (1 << NFTNL_EXPR_LOG_GROUP);
157 }
158 if (tb[NFTA_LOG_SNAPLEN]) {
159 log->snaplen = ntohl(mnl_attr_get_u32(tb[NFTA_LOG_SNAPLEN]));
160 e->flags |= (1 << NFTNL_EXPR_LOG_SNAPLEN);
161 }
162 if (tb[NFTA_LOG_QTHRESHOLD]) {
163 log->qthreshold = ntohs(mnl_attr_get_u16(tb[NFTA_LOG_QTHRESHOLD]));
164 e->flags |= (1 << NFTNL_EXPR_LOG_QTHRESHOLD);
165 }
166 if (tb[NFTA_LOG_LEVEL]) {
167 log->level = ntohl(mnl_attr_get_u32(tb[NFTA_LOG_LEVEL]));
168 e->flags |= (1 << NFTNL_EXPR_LOG_LEVEL);
169 }
170 if (tb[NFTA_LOG_FLAGS]) {
171 log->flags = ntohl(mnl_attr_get_u32(tb[NFTA_LOG_FLAGS]));
172 e->flags |= (1 << NFTNL_EXPR_LOG_FLAGS);
173 }
174
175 return 0;
176}
177
178static int
179nftnl_expr_log_snprintf(char *buf, size_t remain,
180 uint32_t flags, const struct nftnl_expr *e)
181{
182 struct nftnl_expr_log *log = nftnl_expr_data(e);
183 int ret, offset = 0;
184
185 if (e->flags & (1 << NFTNL_EXPR_LOG_PREFIX)) {
186 ret = snprintf(buf, remain, "prefix %s ", log->prefix);
187 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
188 }
189
190 if (e->flags & (1 << NFTNL_EXPR_LOG_GROUP)) {
191 ret = snprintf(buf + offset, remain,
192 "group %u snaplen %u qthreshold %u ",
193 log->group, log->snaplen, log->qthreshold);
194 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
195 } else {
196 if (e->flags & (1 << NFTNL_EXPR_LOG_LEVEL)) {
197 ret = snprintf(buf + offset, remain, "level %u ",
198 log->level);
199 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
200 }
201 if (e->flags & (1 << NFTNL_EXPR_LOG_FLAGS)) {
202 if (log->flags & NF_LOG_TCPSEQ) {
203 ret = snprintf(buf + offset, remain, "tcpseq ");
204 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
205 }
206 if (log->flags & NF_LOG_TCPOPT) {
207 ret = snprintf(buf + offset, remain, "tcpopt ");
208 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
209 }
210 if (log->flags & NF_LOG_IPOPT) {
211 ret = snprintf(buf + offset, remain, "ipopt ");
212 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
213 }
214 if (log->flags & NF_LOG_UID) {
215 ret = snprintf(buf + offset, remain, "uid ");
216 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
217 }
218 if (log->flags & NF_LOG_MACDECODE) {
219 ret = snprintf(buf + offset, remain,
220 "macdecode ");
221 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
222 }
223 }
224 }
225
226 return offset;
227}
228
229static void nftnl_expr_log_free(const struct nftnl_expr *e)
230{
231 struct nftnl_expr_log *log = nftnl_expr_data(e);
232
233 xfree(log->prefix);
234}
235
236static struct attr_policy log_attr_policy[__NFTNL_EXPR_LOG_MAX] = {
237 [NFTNL_EXPR_LOG_PREFIX] = { .maxlen = NF_LOG_PREFIXLEN },
238 [NFTNL_EXPR_LOG_GROUP] = { .maxlen = sizeof(uint16_t) },
239 [NFTNL_EXPR_LOG_SNAPLEN] = { .maxlen = sizeof(uint32_t) },
240 [NFTNL_EXPR_LOG_QTHRESHOLD] = { .maxlen = sizeof(uint16_t) },
241 [NFTNL_EXPR_LOG_LEVEL] = { .maxlen = sizeof(uint32_t) },
242 [NFTNL_EXPR_LOG_FLAGS] = { .maxlen = sizeof(uint32_t) },
243};
244
245struct expr_ops expr_ops_log = {
246 .name = "log",
247 .alloc_len = sizeof(struct nftnl_expr_log),
248 .nftnl_max_attr = __NFTNL_EXPR_LOG_MAX - 1,
249 .attr_policy = log_attr_policy,
250 .free = nftnl_expr_log_free,
251 .set = nftnl_expr_log_set,
252 .get = nftnl_expr_log_get,
253 .parse = nftnl_expr_log_parse,
254 .build = nftnl_expr_log_build,
255 .output = nftnl_expr_log_snprintf,
256};
nftnl_expr_log
Definition log.c:21
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