libnftnl 1.3.2
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
31nftnl_expr_log_set(struct nftnl_expr *e, uint16_t type,
32 const void *data, uint32_t data_len, uint32_t byteorder)
33{
34 struct nftnl_expr_log *log = nftnl_expr_data(e);
35
36 switch(type) {
37 case NFTNL_EXPR_LOG_PREFIX:
38 if (log->flags & (1 << NFTNL_EXPR_LOG_PREFIX))
39 xfree(log->prefix);
40
41 log->prefix = strdup(data);
42 if (!log->prefix)
43 return -1;
44 break;
45 case NFTNL_EXPR_LOG_GROUP:
46 memcpy(&log->group, data, data_len);
47 break;
48 case NFTNL_EXPR_LOG_SNAPLEN:
49 memcpy(&log->snaplen, data, data_len);
50 break;
51 case NFTNL_EXPR_LOG_QTHRESHOLD:
52 memcpy(&log->qthreshold, data, data_len);
53 break;
54 case NFTNL_EXPR_LOG_LEVEL:
55 memcpy(&log->level, data, data_len);
56 break;
57 case NFTNL_EXPR_LOG_FLAGS:
58 memcpy(&log->flags, data, data_len);
59 break;
60 }
61 return 0;
62}
63
64static const void *
65nftnl_expr_log_get(const struct nftnl_expr *e, uint16_t type,
66 uint32_t *data_len)
67{
68 struct nftnl_expr_log *log = nftnl_expr_data(e);
69
70 switch(type) {
71 case NFTNL_EXPR_LOG_PREFIX:
72 *data_len = strlen(log->prefix)+1;
73 return log->prefix;
74 case NFTNL_EXPR_LOG_GROUP:
75 *data_len = sizeof(log->group);
76 return &log->group;
77 case NFTNL_EXPR_LOG_SNAPLEN:
78 *data_len = sizeof(log->snaplen);
79 return &log->snaplen;
80 case NFTNL_EXPR_LOG_QTHRESHOLD:
81 *data_len = sizeof(log->qthreshold);
82 return &log->qthreshold;
83 case NFTNL_EXPR_LOG_LEVEL:
84 *data_len = sizeof(log->level);
85 return &log->level;
86 case NFTNL_EXPR_LOG_FLAGS:
87 *data_len = sizeof(log->flags);
88 return &log->flags;
89 }
90 return NULL;
91}
92
93static int nftnl_expr_log_cb(const struct nlattr *attr, void *data)
94{
95 const struct nlattr **tb = data;
96 int type = mnl_attr_get_type(attr);
97
98 if (mnl_attr_type_valid(attr, NFTA_LOG_MAX) < 0)
99 return MNL_CB_OK;
100
101 switch(type) {
102 case NFTA_LOG_PREFIX:
103 if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0)
104 abi_breakage();
105 break;
106 case NFTA_LOG_GROUP:
107 case NFTA_LOG_QTHRESHOLD:
108 if (mnl_attr_validate(attr, MNL_TYPE_U16) < 0)
109 abi_breakage();
110 break;
111 case NFTA_LOG_SNAPLEN:
112 case NFTA_LOG_LEVEL:
113 case NFTA_LOG_FLAGS:
114 if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
115 abi_breakage();
116 break;
117 }
118
119 tb[type] = attr;
120 return MNL_CB_OK;
121}
122
123static void
124nftnl_expr_log_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
125{
126 struct nftnl_expr_log *log = nftnl_expr_data(e);
127
128 if (e->flags & (1 << NFTNL_EXPR_LOG_PREFIX))
129 mnl_attr_put_strz(nlh, NFTA_LOG_PREFIX, log->prefix);
130 if (e->flags & (1 << NFTNL_EXPR_LOG_GROUP))
131 mnl_attr_put_u16(nlh, NFTA_LOG_GROUP, htons(log->group));
132 if (e->flags & (1 << NFTNL_EXPR_LOG_SNAPLEN))
133 mnl_attr_put_u32(nlh, NFTA_LOG_SNAPLEN, htonl(log->snaplen));
134 if (e->flags & (1 << NFTNL_EXPR_LOG_QTHRESHOLD))
135 mnl_attr_put_u16(nlh, NFTA_LOG_QTHRESHOLD, htons(log->qthreshold));
136 if (e->flags & (1 << NFTNL_EXPR_LOG_LEVEL))
137 mnl_attr_put_u32(nlh, NFTA_LOG_LEVEL, htonl(log->level));
138 if (e->flags & (1 << NFTNL_EXPR_LOG_FLAGS))
139 mnl_attr_put_u32(nlh, NFTA_LOG_FLAGS, htonl(log->flags));
140}
141
142static int
143nftnl_expr_log_parse(struct nftnl_expr *e, struct nlattr *attr)
144{
145 struct nftnl_expr_log *log = nftnl_expr_data(e);
146 struct nlattr *tb[NFTA_LOG_MAX+1] = {};
147
148 if (mnl_attr_parse_nested(attr, nftnl_expr_log_cb, tb) < 0)
149 return -1;
150
151 if (nftnl_parse_str_attr(tb[NFTA_LOG_PREFIX],
152 NFTNL_EXPR_LOG_PREFIX,
153 &log->prefix, &e->flags) < 0)
154 return -1;
155 if (tb[NFTA_LOG_GROUP]) {
156 log->group = ntohs(mnl_attr_get_u16(tb[NFTA_LOG_GROUP]));
157 e->flags |= (1 << NFTNL_EXPR_LOG_GROUP);
158 }
159 if (tb[NFTA_LOG_SNAPLEN]) {
160 log->snaplen = ntohl(mnl_attr_get_u32(tb[NFTA_LOG_SNAPLEN]));
161 e->flags |= (1 << NFTNL_EXPR_LOG_SNAPLEN);
162 }
163 if (tb[NFTA_LOG_QTHRESHOLD]) {
164 log->qthreshold = ntohs(mnl_attr_get_u16(tb[NFTA_LOG_QTHRESHOLD]));
165 e->flags |= (1 << NFTNL_EXPR_LOG_QTHRESHOLD);
166 }
167 if (tb[NFTA_LOG_LEVEL]) {
168 log->level = ntohl(mnl_attr_get_u32(tb[NFTA_LOG_LEVEL]));
169 e->flags |= (1 << NFTNL_EXPR_LOG_LEVEL);
170 }
171 if (tb[NFTA_LOG_FLAGS]) {
172 log->flags = ntohl(mnl_attr_get_u32(tb[NFTA_LOG_FLAGS]));
173 e->flags |= (1 << NFTNL_EXPR_LOG_FLAGS);
174 }
175
176 return 0;
177}
178
179static int
180nftnl_expr_log_snprintf(char *buf, size_t remain,
181 uint32_t flags, const struct nftnl_expr *e)
182{
183 struct nftnl_expr_log *log = nftnl_expr_data(e);
184 int ret, offset = 0;
185
186 if (e->flags & (1 << NFTNL_EXPR_LOG_PREFIX)) {
187 ret = snprintf(buf, remain, "prefix %s ", log->prefix);
188 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
189 }
190
191 if (e->flags & (1 << NFTNL_EXPR_LOG_GROUP)) {
192 ret = snprintf(buf + offset, remain,
193 "group %u snaplen %u qthreshold %u ",
194 log->group, log->snaplen, log->qthreshold);
195 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
196 } else {
197 if (e->flags & (1 << NFTNL_EXPR_LOG_LEVEL)) {
198 ret = snprintf(buf + offset, remain, "level %u ",
199 log->level);
200 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
201 }
202 if (e->flags & (1 << NFTNL_EXPR_LOG_FLAGS)) {
203 if (log->flags & NF_LOG_TCPSEQ) {
204 ret = snprintf(buf + offset, remain, "tcpseq ");
205 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
206 }
207 if (log->flags & NF_LOG_TCPOPT) {
208 ret = snprintf(buf + offset, remain, "tcpopt ");
209 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
210 }
211 if (log->flags & NF_LOG_IPOPT) {
212 ret = snprintf(buf + offset, remain, "ipopt ");
213 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
214 }
215 if (log->flags & NF_LOG_UID) {
216 ret = snprintf(buf + offset, remain, "uid ");
217 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
218 }
219 if (log->flags & NF_LOG_MACDECODE) {
220 ret = snprintf(buf + offset, remain,
221 "macdecode ");
222 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
223 }
224 }
225 }
226
227 return offset;
228}
229
230static void nftnl_expr_log_free(const struct nftnl_expr *e)
231{
232 struct nftnl_expr_log *log = nftnl_expr_data(e);
233
234 xfree(log->prefix);
235}
236
237static struct attr_policy log_attr_policy[__NFTNL_EXPR_LOG_MAX] = {
238 [NFTNL_EXPR_LOG_PREFIX] = { .maxlen = NF_LOG_PREFIXLEN },
239 [NFTNL_EXPR_LOG_GROUP] = { .maxlen = sizeof(uint16_t) },
240 [NFTNL_EXPR_LOG_SNAPLEN] = { .maxlen = sizeof(uint32_t) },
241 [NFTNL_EXPR_LOG_QTHRESHOLD] = { .maxlen = sizeof(uint16_t) },
242 [NFTNL_EXPR_LOG_LEVEL] = { .maxlen = sizeof(uint32_t) },
243 [NFTNL_EXPR_LOG_FLAGS] = { .maxlen = sizeof(uint32_t) },
244};
245
246struct expr_ops expr_ops_log = {
247 .name = "log",
248 .alloc_len = sizeof(struct nftnl_expr_log),
249 .nftnl_max_attr = __NFTNL_EXPR_LOG_MAX - 1,
250 .attr_policy = log_attr_policy,
251 .free = nftnl_expr_log_free,
252 .set = nftnl_expr_log_set,
253 .get = nftnl_expr_log_get,
254 .parse = nftnl_expr_log_parse,
255 .build = nftnl_expr_log_build,
256 .output = nftnl_expr_log_snprintf,
257};
nftnl_expr_log
Definition log.c:21
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