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 28 static unsigned int 29 log_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 44 static 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 64 static void log_tg_destroy(const struct xt_tgdtor_param *par) 65 { 66 nf_logger_put(par->family, NF_LOG_TYPE_LOG); 67 } 68 69 static 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 92 static int __init log_tg_init(void) 93 { 94 return xt_register_targets(log_tg_regs, ARRAY_SIZE(log_tg_regs)); 95 } 96 97 static void __exit log_tg_exit(void) 98 { 99 xt_unregister_targets(log_tg_regs, ARRAY_SIZE(log_tg_regs)); 100 } 101 102 module_init(log_tg_init); 103 module_exit(log_tg_exit); 104 105 MODULE_LICENSE("GPL"); 106 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); 107 MODULE_AUTHOR("Jan Rekorajski <baggins@pld.org.pl>"); 108 MODULE_DESCRIPTION("Xtables: IPv4/IPv6 packet logging"); 109 MODULE_ALIAS("ipt_LOG"); 110 MODULE_ALIAS("ip6t_LOG"); 111