1 /*
2 * This is a module which is used for logging packets.
3 */
4
5 /* (C) 1999-2001 Paul `Rusty' Russell
6 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 #include <linux/module.h>
15 #include <linux/spinlock.h>
16 #include <linux/skbuff.h>
17 #include <linux/if_arp.h>
18 #include <linux/ip.h>
19 #include <net/ipv6.h>
20 #include <net/icmp.h>
21 #include <net/udp.h>
22 #include <net/tcp.h>
23 #include <net/route.h>
24
25 #include <linux/netfilter.h>
26 #include <linux/netfilter/x_tables.h>
27 #include <linux/netfilter/xt_LOG.h>
28 #include <linux/netfilter_ipv6/ip6_tables.h>
29 #include <net/netfilter/nf_log.h>
30
31 static unsigned int
log_tg(struct sk_buff * skb,const struct xt_action_param * par)32 log_tg(struct sk_buff *skb, const struct xt_action_param *par)
33 {
34 const struct xt_log_info *loginfo = par->targinfo;
35 struct net *net = xt_net(par);
36 struct nf_loginfo li;
37
38 li.type = NF_LOG_TYPE_LOG;
39 li.u.log.level = loginfo->level;
40 li.u.log.logflags = loginfo->logflags;
41
42 nf_log_packet(net, xt_family(par), xt_hooknum(par), skb, xt_in(par),
43 xt_out(par), &li, "%s", loginfo->prefix);
44 return XT_CONTINUE;
45 }
46
log_tg_check(const struct xt_tgchk_param * par)47 static int log_tg_check(const struct xt_tgchk_param *par)
48 {
49 const struct xt_log_info *loginfo = par->targinfo;
50
51 if (par->family != NFPROTO_IPV4 && par->family != NFPROTO_IPV6)
52 return -EINVAL;
53
54 if (loginfo->level >= 8) {
55 pr_debug("level %u >= 8\n", loginfo->level);
56 return -EINVAL;
57 }
58
59 if (loginfo->prefix[sizeof(loginfo->prefix)-1] != '\0') {
60 pr_debug("prefix is not null-terminated\n");
61 return -EINVAL;
62 }
63
64 return nf_logger_find_get(par->family, NF_LOG_TYPE_LOG);
65 }
66
log_tg_destroy(const struct xt_tgdtor_param * par)67 static void log_tg_destroy(const struct xt_tgdtor_param *par)
68 {
69 nf_logger_put(par->family, NF_LOG_TYPE_LOG);
70 }
71
72 static struct xt_target log_tg_regs[] __read_mostly = {
73 {
74 .name = "LOG",
75 .family = NFPROTO_IPV4,
76 .target = log_tg,
77 .targetsize = sizeof(struct xt_log_info),
78 .checkentry = log_tg_check,
79 .destroy = log_tg_destroy,
80 .me = THIS_MODULE,
81 },
82 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
83 {
84 .name = "LOG",
85 .family = NFPROTO_IPV6,
86 .target = log_tg,
87 .targetsize = sizeof(struct xt_log_info),
88 .checkentry = log_tg_check,
89 .destroy = log_tg_destroy,
90 .me = THIS_MODULE,
91 },
92 #endif
93 };
94
log_tg_init(void)95 static int __init log_tg_init(void)
96 {
97 return xt_register_targets(log_tg_regs, ARRAY_SIZE(log_tg_regs));
98 }
99
log_tg_exit(void)100 static void __exit log_tg_exit(void)
101 {
102 xt_unregister_targets(log_tg_regs, ARRAY_SIZE(log_tg_regs));
103 }
104
105 module_init(log_tg_init);
106 module_exit(log_tg_exit);
107
108 MODULE_LICENSE("GPL");
109 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
110 MODULE_AUTHOR("Jan Rekorajski <baggins@pld.org.pl>");
111 MODULE_DESCRIPTION("Xtables: IPv4/IPv6 packet logging");
112 MODULE_ALIAS("ipt_LOG");
113 MODULE_ALIAS("ip6t_LOG");
114
