1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2006 Patrick McHardy <kaber@trash.net>
4  */
5 
6 #include <linux/module.h>
7 #include <linux/init.h>
8 #include <linux/skbuff.h>
9 
10 #include <linux/netfilter/x_tables.h>
11 #include <linux/netfilter/xt_NFLOG.h>
12 #include <net/netfilter/nf_log.h>
13 
14 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
15 MODULE_DESCRIPTION("Xtables: packet logging to netlink using NFLOG");
16 MODULE_LICENSE("GPL");
17 MODULE_ALIAS("ipt_NFLOG");
18 MODULE_ALIAS("ip6t_NFLOG");
19 
20 static unsigned int
nflog_tg(struct sk_buff * skb,const struct xt_action_param * par)21 nflog_tg(struct sk_buff *skb, const struct xt_action_param *par)
22 {
23 	const struct xt_nflog_info *info = par->targinfo;
24 	struct net *net = xt_net(par);
25 	struct nf_loginfo li;
26 
27 	li.type		     = NF_LOG_TYPE_ULOG;
28 	li.u.ulog.copy_len   = info->len;
29 	li.u.ulog.group	     = info->group;
30 	li.u.ulog.qthreshold = info->threshold;
31 	li.u.ulog.flags	     = 0;
32 
33 	if (info->flags & XT_NFLOG_F_COPY_LEN)
34 		li.u.ulog.flags |= NF_LOG_F_COPY_LEN;
35 
36 	nf_log_packet(net, xt_family(par), xt_hooknum(par), skb, xt_in(par),
37 		      xt_out(par), &li, "%s", info->prefix);
38 
39 	return XT_CONTINUE;
40 }
41 
nflog_tg_check(const struct xt_tgchk_param * par)42 static int nflog_tg_check(const struct xt_tgchk_param *par)
43 {
44 	const struct xt_nflog_info *info = par->targinfo;
45 	int ret;
46 
47 	if (info->flags & ~XT_NFLOG_MASK)
48 		return -EINVAL;
49 	if (info->prefix[sizeof(info->prefix) - 1] != '\0')
50 		return -EINVAL;
51 
52 	ret = nf_logger_find_get(par->family, NF_LOG_TYPE_ULOG);
53 	if (ret != 0 && !par->nft_compat) {
54 		request_module("%s", "nfnetlink_log");
55 
56 		ret = nf_logger_find_get(par->family, NF_LOG_TYPE_ULOG);
57 	}
58 
59 	return ret;
60 }
61 
nflog_tg_destroy(const struct xt_tgdtor_param * par)62 static void nflog_tg_destroy(const struct xt_tgdtor_param *par)
63 {
64 	nf_logger_put(par->family, NF_LOG_TYPE_ULOG);
65 }
66 
67 static struct xt_target nflog_tg_reg __read_mostly = {
68 	.name       = "NFLOG",
69 	.revision   = 0,
70 	.family     = NFPROTO_UNSPEC,
71 	.checkentry = nflog_tg_check,
72 	.destroy    = nflog_tg_destroy,
73 	.target     = nflog_tg,
74 	.targetsize = sizeof(struct xt_nflog_info),
75 	.me         = THIS_MODULE,
76 };
77 
nflog_tg_init(void)78 static int __init nflog_tg_init(void)
79 {
80 	return xt_register_target(&nflog_tg_reg);
81 }
82 
nflog_tg_exit(void)83 static void __exit nflog_tg_exit(void)
84 {
85 	xt_unregister_target(&nflog_tg_reg);
86 }
87 
88 module_init(nflog_tg_init);
89 module_exit(nflog_tg_exit);
90 MODULE_SOFTDEP("pre: nfnetlink_log");
91