1/* 2 * ebt_log 3 * 4 * Authors: 5 * Bart De Schuymer <bdschuym@pandora.be> 6 * Harald Welte <laforge@netfilter.org> 7 * 8 * April, 2002 9 * 10 */ 11#include <linux/module.h> 12#include <linux/ip.h> 13#include <linux/in.h> 14#include <linux/if_arp.h> 15#include <linux/spinlock.h> 16#include <net/netfilter/nf_log.h> 17#include <linux/ipv6.h> 18#include <net/ipv6.h> 19#include <linux/in6.h> 20#include <linux/netfilter/x_tables.h> 21#include <linux/netfilter_bridge/ebtables.h> 22#include <linux/netfilter_bridge/ebt_log.h> 23#include <linux/netfilter.h> 24 25static DEFINE_SPINLOCK(ebt_log_lock); 26 27static int ebt_log_tg_check(const struct xt_tgchk_param *par) 28{ 29 struct ebt_log_info *info = par->targinfo; 30 31 if (info->bitmask & ~EBT_LOG_MASK) 32 return -EINVAL; 33 if (info->loglevel >= 8) 34 return -EINVAL; 35 info->prefix[EBT_LOG_PREFIX_SIZE - 1] = '\0'; 36 return 0; 37} 38 39struct tcpudphdr 40{ 41 __be16 src; 42 __be16 dst; 43}; 44 45struct arppayload 46{ 47 unsigned char mac_src[ETH_ALEN]; 48 unsigned char ip_src[4]; 49 unsigned char mac_dst[ETH_ALEN]; 50 unsigned char ip_dst[4]; 51}; 52 53static void 54print_ports(const struct sk_buff *skb, uint8_t protocol, int offset) 55{ 56 if (protocol == IPPROTO_TCP || 57 protocol == IPPROTO_UDP || 58 protocol == IPPROTO_UDPLITE || 59 protocol == IPPROTO_SCTP || 60 protocol == IPPROTO_DCCP) { 61 const struct tcpudphdr *pptr; 62 struct tcpudphdr _ports; 63 64 pptr = skb_header_pointer(skb, offset, 65 sizeof(_ports), &_ports); 66 if (pptr == NULL) { 67 printk(" INCOMPLETE TCP/UDP header"); 68 return; 69 } 70 printk(" SPT=%u DPT=%u", ntohs(pptr->src), ntohs(pptr->dst)); 71 } 72} 73 74static void 75ebt_log_packet(u_int8_t pf, unsigned int hooknum, 76 const struct sk_buff *skb, const struct net_device *in, 77 const struct net_device *out, const struct nf_loginfo *loginfo, 78 const char *prefix) 79{ 80 unsigned int bitmask; 81 82 spin_lock_bh(&ebt_log_lock); 83 printk("<%c>%s IN=%s OUT=%s MAC source = %pM MAC dest = %pM proto = 0x%04x", 84 '0' + loginfo->u.log.level, prefix, 85 in ? in->name : "", out ? out->name : "", 86 eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest, 87 ntohs(eth_hdr(skb)->h_proto)); 88 89 if (loginfo->type == NF_LOG_TYPE_LOG) 90 bitmask = loginfo->u.log.logflags; 91 else 92 bitmask = NF_LOG_MASK; 93 94 if ((bitmask & EBT_LOG_IP) && eth_hdr(skb)->h_proto == 95 htons(ETH_P_IP)){ 96 const struct iphdr *ih; 97 struct iphdr _iph; 98 99 ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph); 100 if (ih == NULL) { 101 printk(" INCOMPLETE IP header"); 102 goto out; 103 } 104 printk(" IP SRC=%pI4 IP DST=%pI4, IP tos=0x%02X, IP proto=%d", 105 &ih->saddr, &ih->daddr, ih->tos, ih->protocol); 106 print_ports(skb, ih->protocol, ih->ihl*4); 107 goto out; 108 } 109 110#if defined(CONFIG_BRIDGE_EBT_IP6) || defined(CONFIG_BRIDGE_EBT_IP6_MODULE) 111 if ((bitmask & EBT_LOG_IP6) && eth_hdr(skb)->h_proto == 112 htons(ETH_P_IPV6)) { 113 const struct ipv6hdr *ih; 114 struct ipv6hdr _iph; 115 uint8_t nexthdr; 116 int offset_ph; 117 118 ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph); 119 if (ih == NULL) { 120 printk(" INCOMPLETE IPv6 header"); 121 goto out; 122 } 123 printk(" IPv6 SRC=%pI6 IPv6 DST=%pI6, IPv6 priority=0x%01X, Next Header=%d", 124 &ih->saddr, &ih->daddr, ih->priority, ih->nexthdr); 125 nexthdr = ih->nexthdr; 126 offset_ph = ipv6_skip_exthdr(skb, sizeof(_iph), &nexthdr); 127 if (offset_ph == -1) 128 goto out; 129 print_ports(skb, nexthdr, offset_ph); 130 goto out; 131 } 132#endif 133 134 if ((bitmask & EBT_LOG_ARP) && 135 ((eth_hdr(skb)->h_proto == htons(ETH_P_ARP)) || 136 (eth_hdr(skb)->h_proto == htons(ETH_P_RARP)))) { 137 const struct arphdr *ah; 138 struct arphdr _arph; 139 140 ah = skb_header_pointer(skb, 0, sizeof(_arph), &_arph); 141 if (ah == NULL) { 142 printk(" INCOMPLETE ARP header"); 143 goto out; 144 } 145 printk(" ARP HTYPE=%d, PTYPE=0x%04x, OPCODE=%d", 146 ntohs(ah->ar_hrd), ntohs(ah->ar_pro), 147 ntohs(ah->ar_op)); 148 149 /* If it's for Ethernet and the lengths are OK, 150 * then log the ARP payload */ 151 if (ah->ar_hrd == htons(1) && 152 ah->ar_hln == ETH_ALEN && 153 ah->ar_pln == sizeof(__be32)) { 154 const struct arppayload *ap; 155 struct arppayload _arpp; 156 157 ap = skb_header_pointer(skb, sizeof(_arph), 158 sizeof(_arpp), &_arpp); 159 if (ap == NULL) { 160 printk(" INCOMPLETE ARP payload"); 161 goto out; 162 } 163 printk(" ARP MAC SRC=%pM ARP IP SRC=%pI4 ARP MAC DST=%pM ARP IP DST=%pI4", 164 ap->mac_src, ap->ip_src, ap->mac_dst, ap->ip_dst); 165 } 166 } 167out: 168 printk("\n"); 169 spin_unlock_bh(&ebt_log_lock); 170 171} 172 173static unsigned int 174ebt_log_tg(struct sk_buff *skb, const struct xt_action_param *par) 175{ 176 const struct ebt_log_info *info = par->targinfo; 177 struct nf_loginfo li; 178 179 li.type = NF_LOG_TYPE_LOG; 180 li.u.log.level = info->loglevel; 181 li.u.log.logflags = info->bitmask; 182 183 if (info->bitmask & EBT_LOG_NFLOG) 184 nf_log_packet(NFPROTO_BRIDGE, par->hooknum, skb, par->in, 185 par->out, &li, "%s", info->prefix); 186 else 187 ebt_log_packet(NFPROTO_BRIDGE, par->hooknum, skb, par->in, 188 par->out, &li, info->prefix); 189 return EBT_CONTINUE; 190} 191 192static struct xt_target ebt_log_tg_reg __read_mostly = { 193 .name = "log", 194 .revision = 0, 195 .family = NFPROTO_BRIDGE, 196 .target = ebt_log_tg, 197 .checkentry = ebt_log_tg_check, 198 .targetsize = sizeof(struct ebt_log_info), 199 .me = THIS_MODULE, 200}; 201 202static struct nf_logger ebt_log_logger __read_mostly = { 203 .name = "ebt_log", 204 .logfn = &ebt_log_packet, 205 .me = THIS_MODULE, 206}; 207 208static int __init ebt_log_init(void) 209{ 210 int ret; 211 212 ret = xt_register_target(&ebt_log_tg_reg); 213 if (ret < 0) 214 return ret; 215 nf_log_register(NFPROTO_BRIDGE, &ebt_log_logger); 216 return 0; 217} 218 219static void __exit ebt_log_fini(void) 220{ 221 nf_log_unregister(&ebt_log_logger); 222 xt_unregister_target(&ebt_log_tg_reg); 223} 224 225module_init(ebt_log_init); 226module_exit(ebt_log_fini); 227MODULE_DESCRIPTION("Ebtables: Packet logging to syslog"); 228MODULE_LICENSE("GPL"); 229