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 12#include <linux/in.h> 13#include <linux/netfilter_bridge/ebtables.h> 14#include <linux/netfilter_bridge/ebt_log.h> 15#include <linux/netfilter.h> 16#include <linux/module.h> 17#include <linux/ip.h> 18#include <linux/in.h> 19#include <linux/if_arp.h> 20#include <linux/spinlock.h> 21 22static DEFINE_SPINLOCK(ebt_log_lock); 23 24static int ebt_log_check(const char *tablename, unsigned int hookmask, 25 const struct ebt_entry *e, void *data, unsigned int datalen) 26{ 27 struct ebt_log_info *info = (struct ebt_log_info *)data; 28 29 if (datalen != EBT_ALIGN(sizeof(struct ebt_log_info))) 30 return -EINVAL; 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 print_MAC(unsigned char *p) 54{ 55 int i; 56 57 for (i = 0; i < ETH_ALEN; i++, p++) 58 printk("%02x%c", *p, i == ETH_ALEN - 1 ? ' ':':'); 59} 60 61#define myNIPQUAD(a) a[0], a[1], a[2], a[3] 62static void 63ebt_log_packet(unsigned int pf, unsigned int hooknum, 64 const struct sk_buff *skb, const struct net_device *in, 65 const struct net_device *out, const struct nf_loginfo *loginfo, 66 const char *prefix) 67{ 68 unsigned int bitmask; 69 70 spin_lock_bh(&ebt_log_lock); 71 printk("<%c>%s IN=%s OUT=%s MAC source = ", '0' + loginfo->u.log.level, 72 prefix, in ? in->name : "", out ? out->name : ""); 73 74 print_MAC(eth_hdr(skb)->h_source); 75 printk("MAC dest = "); 76 print_MAC(eth_hdr(skb)->h_dest); 77 78 printk("proto = 0x%04x", ntohs(eth_hdr(skb)->h_proto)); 79 80 if (loginfo->type == NF_LOG_TYPE_LOG) 81 bitmask = loginfo->u.log.logflags; 82 else 83 bitmask = NF_LOG_MASK; 84 85 if ((bitmask & EBT_LOG_IP) && eth_hdr(skb)->h_proto == 86 htons(ETH_P_IP)){ 87 struct iphdr _iph, *ih; 88 89 ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph); 90 if (ih == NULL) { 91 printk(" INCOMPLETE IP header"); 92 goto out; 93 } 94 printk(" IP SRC=%u.%u.%u.%u IP DST=%u.%u.%u.%u, IP " 95 "tos=0x%02X, IP proto=%d", NIPQUAD(ih->saddr), 96 NIPQUAD(ih->daddr), ih->tos, ih->protocol); 97 if (ih->protocol == IPPROTO_TCP || 98 ih->protocol == IPPROTO_UDP || 99 ih->protocol == IPPROTO_UDPLITE || 100 ih->protocol == IPPROTO_SCTP || 101 ih->protocol == IPPROTO_DCCP) { 102 struct tcpudphdr _ports, *pptr; 103 104 pptr = skb_header_pointer(skb, ih->ihl*4, 105 sizeof(_ports), &_ports); 106 if (pptr == NULL) { 107 printk(" INCOMPLETE TCP/UDP header"); 108 goto out; 109 } 110 printk(" SPT=%u DPT=%u", ntohs(pptr->src), 111 ntohs(pptr->dst)); 112 } 113 goto out; 114 } 115 116 if ((bitmask & EBT_LOG_ARP) && 117 ((eth_hdr(skb)->h_proto == htons(ETH_P_ARP)) || 118 (eth_hdr(skb)->h_proto == htons(ETH_P_RARP)))) { 119 struct arphdr _arph, *ah; 120 121 ah = skb_header_pointer(skb, 0, sizeof(_arph), &_arph); 122 if (ah == NULL) { 123 printk(" INCOMPLETE ARP header"); 124 goto out; 125 } 126 printk(" ARP HTYPE=%d, PTYPE=0x%04x, OPCODE=%d", 127 ntohs(ah->ar_hrd), ntohs(ah->ar_pro), 128 ntohs(ah->ar_op)); 129 130 /* If it's for Ethernet and the lengths are OK, 131 * then log the ARP payload */ 132 if (ah->ar_hrd == htons(1) && 133 ah->ar_hln == ETH_ALEN && 134 ah->ar_pln == sizeof(__be32)) { 135 struct arppayload _arpp, *ap; 136 137 ap = skb_header_pointer(skb, sizeof(_arph), 138 sizeof(_arpp), &_arpp); 139 if (ap == NULL) { 140 printk(" INCOMPLETE ARP payload"); 141 goto out; 142 } 143 printk(" ARP MAC SRC="); 144 print_MAC(ap->mac_src); 145 printk(" ARP IP SRC=%u.%u.%u.%u", 146 myNIPQUAD(ap->ip_src)); 147 printk(" ARP MAC DST="); 148 print_MAC(ap->mac_dst); 149 printk(" ARP IP DST=%u.%u.%u.%u", 150 myNIPQUAD(ap->ip_dst)); 151 } 152 } 153out: 154 printk("\n"); 155 spin_unlock_bh(&ebt_log_lock); 156 157} 158 159static void ebt_log(const struct sk_buff *skb, unsigned int hooknr, 160 const struct net_device *in, const struct net_device *out, 161 const void *data, unsigned int datalen) 162{ 163 struct ebt_log_info *info = (struct ebt_log_info *)data; 164 struct nf_loginfo li; 165 166 li.type = NF_LOG_TYPE_LOG; 167 li.u.log.level = info->loglevel; 168 li.u.log.logflags = info->bitmask; 169 170 if (info->bitmask & EBT_LOG_NFLOG) 171 nf_log_packet(PF_BRIDGE, hooknr, skb, in, out, &li, 172 "%s", info->prefix); 173 else 174 ebt_log_packet(PF_BRIDGE, hooknr, skb, in, out, &li, 175 info->prefix); 176} 177 178static struct ebt_watcher log = 179{ 180 .name = EBT_LOG_WATCHER, 181 .watcher = ebt_log, 182 .check = ebt_log_check, 183 .me = THIS_MODULE, 184}; 185 186static struct nf_logger ebt_log_logger = { 187 .name = "ebt_log", 188 .logfn = &ebt_log_packet, 189 .me = THIS_MODULE, 190}; 191 192static int __init ebt_log_init(void) 193{ 194 int ret; 195 196 ret = ebt_register_watcher(&log); 197 if (ret < 0) 198 return ret; 199 ret = nf_log_register(PF_BRIDGE, &ebt_log_logger); 200 if (ret < 0 && ret != -EEXIST) 201 ebt_unregister_watcher(&log); 202 return ret; 203} 204 205static void __exit ebt_log_fini(void) 206{ 207 nf_log_unregister(&ebt_log_logger); 208 ebt_unregister_watcher(&log); 209} 210 211module_init(ebt_log_init); 212module_exit(ebt_log_fini); 213MODULE_LICENSE("GPL"); 214