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 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 nf_loginfo li; 36 struct net *net = par->net; 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, par->family, par->hooknum, skb, par->in, par->out, 43 &li, "%s", loginfo->prefix); 44 return XT_CONTINUE; 45 } 46 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 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 95 static int __init log_tg_init(void) 96 { 97 return xt_register_targets(log_tg_regs, ARRAY_SIZE(log_tg_regs)); 98 } 99 100 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