net/netfilter/xt_TRACE.c

   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
  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
  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
  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
  57 static int __init trace_tg_init(void)
  58 {
  59         return xt_register_targets(trace_tg_reg, ARRAY_SIZE(trace_tg_reg));
  60 }
  61
  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");