Linux kernel mirror (for testing)
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linux
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * This is a module which is used for logging packets.
4 */
5
6/* (C) 1999-2001 Paul `Rusty' Russell
7 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
8 */
9
10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11#include <linux/module.h>
12#include <linux/spinlock.h>
13#include <linux/skbuff.h>
14#include <linux/if_arp.h>
15#include <linux/ip.h>
16#include <net/ipv6.h>
17#include <net/icmp.h>
18#include <net/udp.h>
19#include <net/tcp.h>
20#include <net/route.h>
21
22#include <linux/netfilter.h>
23#include <linux/netfilter/x_tables.h>
24#include <linux/netfilter/xt_LOG.h>
25#include <linux/netfilter_ipv6/ip6_tables.h>
26#include <net/netfilter/nf_log.h>
27
28static unsigned int
29log_tg(struct sk_buff *skb, const struct xt_action_param *par)
30{
31 const struct xt_log_info *loginfo = par->targinfo;
32 struct net *net = xt_net(par);
33 struct nf_loginfo li;
34
35 li.type = NF_LOG_TYPE_LOG;
36 li.u.log.level = loginfo->level;
37 li.u.log.logflags = loginfo->logflags;
38
39 nf_log_packet(net, xt_family(par), xt_hooknum(par), skb, xt_in(par),
40 xt_out(par), &li, "%s", loginfo->prefix);
41 return XT_CONTINUE;
42}
43
44static int log_tg_check(const struct xt_tgchk_param *par)
45{
46 const struct xt_log_info *loginfo = par->targinfo;
47
48 if (par->family != NFPROTO_IPV4 && par->family != NFPROTO_IPV6)
49 return -EINVAL;
50
51 if (loginfo->level >= 8) {
52 pr_debug("level %u >= 8\n", loginfo->level);
53 return -EINVAL;
54 }
55
56 if (loginfo->prefix[sizeof(loginfo->prefix)-1] != '\0') {
57 pr_debug("prefix is not null-terminated\n");
58 return -EINVAL;
59 }
60
61 return nf_logger_find_get(par->family, NF_LOG_TYPE_LOG);
62}
63
64static void log_tg_destroy(const struct xt_tgdtor_param *par)
65{
66 nf_logger_put(par->family, NF_LOG_TYPE_LOG);
67}
68
69static struct xt_target log_tg_regs[] __read_mostly = {
70 {
71 .name = "LOG",
72 .family = NFPROTO_IPV4,
73 .target = log_tg,
74 .targetsize = sizeof(struct xt_log_info),
75 .checkentry = log_tg_check,
76 .destroy = log_tg_destroy,
77 .me = THIS_MODULE,
78 },
79#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
80 {
81 .name = "LOG",
82 .family = NFPROTO_IPV6,
83 .target = log_tg,
84 .targetsize = sizeof(struct xt_log_info),
85 .checkentry = log_tg_check,
86 .destroy = log_tg_destroy,
87 .me = THIS_MODULE,
88 },
89#endif
90};
91
92static int __init log_tg_init(void)
93{
94 return xt_register_targets(log_tg_regs, ARRAY_SIZE(log_tg_regs));
95}
96
97static void __exit log_tg_exit(void)
98{
99 xt_unregister_targets(log_tg_regs, ARRAY_SIZE(log_tg_regs));
100}
101
102module_init(log_tg_init);
103module_exit(log_tg_exit);
104
105MODULE_LICENSE("GPL");
106MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
107MODULE_AUTHOR("Jan Rekorajski <baggins@pld.org.pl>");
108MODULE_DESCRIPTION("Xtables: IPv4/IPv6 packet logging");
109MODULE_ALIAS("ipt_LOG");
110MODULE_ALIAS("ip6t_LOG");