1 // SPDX-License-Identifier: GPL-2.0-only
2 /* This is a module which is used to mark packets for tracing.
3 */
4 #include <linux/module.h>
5 #include <linux/skbuff.h>
6
7 #include <linux/netfilter/x_tables.h>
8 #include <net/netfilter/nf_log.h>
9
10 MODULE_DESCRIPTION("Xtables: packet flow tracing");
11 MODULE_LICENSE("GPL");
12 MODULE_ALIAS("ipt_TRACE");
13 MODULE_ALIAS("ip6t_TRACE");
14
trace_tg_check(const struct xt_tgchk_param * par)15 static int trace_tg_check(const struct xt_tgchk_param *par)
16 {
17 return nf_logger_find_get(par->family, NF_LOG_TYPE_LOG);
18 }
19
trace_tg_destroy(const struct xt_tgdtor_param * par)20 static void trace_tg_destroy(const struct xt_tgdtor_param *par)
21 {
22 nf_logger_put(par->family, NF_LOG_TYPE_LOG);
23 }
24
25 static unsigned int
trace_tg(struct sk_buff * skb,const struct xt_action_param * par)26 trace_tg(struct sk_buff *skb, const struct xt_action_param *par)
27 {
28 skb->nf_trace = 1;
29 return XT_CONTINUE;
30 }
31
32 static struct xt_target trace_tg_reg[] __read_mostly = {
33 {
34 .name = "TRACE",
35 .revision = 0,
36 .family = NFPROTO_IPV4,
37 .table = "raw",
38 .target = trace_tg,
39 .checkentry = trace_tg_check,
40 .destroy = trace_tg_destroy,
41 .me = THIS_MODULE,
42 },
43 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
44 {
45 .name = "TRACE",
46 .revision = 0,
47 .family = NFPROTO_IPV6,
48 .table = "raw",
49 .target = trace_tg,
50 .checkentry = trace_tg_check,
51 .destroy = trace_tg_destroy,
52 .me = THIS_MODULE,
53 },
54 #endif
55 };
56
trace_tg_init(void)57 static int __init trace_tg_init(void)
58 {
59 return xt_register_targets(trace_tg_reg, ARRAY_SIZE(trace_tg_reg));
60 }
61
trace_tg_exit(void)62 static void __exit trace_tg_exit(void)
63 {
64 xt_unregister_targets(trace_tg_reg, ARRAY_SIZE(trace_tg_reg));
65 }
66
67 module_init(trace_tg_init);
68 module_exit(trace_tg_exit);
69 MODULE_SOFTDEP("pre: nf_log_syslog");
70