/* * ebt_log * * Authors: * Bart De Schuymer * Harald Welte * * April, 2002 * */ #include #include #include #include #include #include #include #include static DEFINE_SPINLOCK(ebt_log_lock); static int ebt_log_check(const char *tablename, unsigned int hookmask, const struct ebt_entry *e, void *data, unsigned int datalen) { struct ebt_log_info *info = (struct ebt_log_info *)data; if (datalen != EBT_ALIGN(sizeof(struct ebt_log_info))) return -EINVAL; if (info->bitmask & ~EBT_LOG_MASK) return -EINVAL; if (info->loglevel >= 8) return -EINVAL; info->prefix[EBT_LOG_PREFIX_SIZE - 1] = '\0'; return 0; } struct tcpudphdr { uint16_t src; uint16_t dst; }; struct arppayload { unsigned char mac_src[ETH_ALEN]; unsigned char ip_src[4]; unsigned char mac_dst[ETH_ALEN]; unsigned char ip_dst[4]; }; static void print_MAC(unsigned char *p) { int i; for (i = 0; i < ETH_ALEN; i++, p++) printk("%02x%c", *p, i == ETH_ALEN - 1 ? ' ':':'); } #define myNIPQUAD(a) a[0], a[1], a[2], a[3] static void ebt_log_packet(unsigned int pf, unsigned int hooknum, const struct sk_buff *skb, const struct net_device *in, const struct net_device *out, const struct nf_loginfo *loginfo, const char *prefix) { unsigned int bitmask; spin_lock_bh(&ebt_log_lock); printk("<%c>%s IN=%s OUT=%s MAC source = ", '0' + loginfo->u.log.level, prefix, in ? in->name : "", out ? out->name : ""); print_MAC(eth_hdr(skb)->h_source); printk("MAC dest = "); print_MAC(eth_hdr(skb)->h_dest); printk("proto = 0x%04x", ntohs(eth_hdr(skb)->h_proto)); if (loginfo->type == NF_LOG_TYPE_LOG) bitmask = loginfo->u.log.logflags; else bitmask = NF_LOG_MASK; if ((bitmask & EBT_LOG_IP) && eth_hdr(skb)->h_proto == htons(ETH_P_IP)){ struct iphdr _iph, *ih; ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph); if (ih == NULL) { printk(" INCOMPLETE IP header"); goto out; } printk(" IP SRC=%u.%u.%u.%u IP DST=%u.%u.%u.%u, IP " "tos=0x%02X, IP proto=%d", NIPQUAD(ih->saddr), NIPQUAD(ih->daddr), ih->tos, ih->protocol); if (ih->protocol == IPPROTO_TCP || ih->protocol == IPPROTO_UDP) { struct tcpudphdr _ports, *pptr; pptr = skb_header_pointer(skb, ih->ihl*4, sizeof(_ports), &_ports); if (pptr == NULL) { printk(" INCOMPLETE TCP/UDP header"); goto out; } printk(" SPT=%u DPT=%u", ntohs(pptr->src), ntohs(pptr->dst)); } goto out; } if ((bitmask & EBT_LOG_ARP) && ((eth_hdr(skb)->h_proto == htons(ETH_P_ARP)) || (eth_hdr(skb)->h_proto == htons(ETH_P_RARP)))) { struct arphdr _arph, *ah; ah = skb_header_pointer(skb, 0, sizeof(_arph), &_arph); if (ah == NULL) { printk(" INCOMPLETE ARP header"); goto out; } printk(" ARP HTYPE=%d, PTYPE=0x%04x, OPCODE=%d", ntohs(ah->ar_hrd), ntohs(ah->ar_pro), ntohs(ah->ar_op)); /* If it's for Ethernet and the lengths are OK, * then log the ARP payload */ if (ah->ar_hrd == htons(1) && ah->ar_hln == ETH_ALEN && ah->ar_pln == sizeof(uint32_t)) { struct arppayload _arpp, *ap; ap = skb_header_pointer(skb, sizeof(_arph), sizeof(_arpp), &_arpp); if (ap == NULL) { printk(" INCOMPLETE ARP payload"); goto out; } printk(" ARP MAC SRC="); print_MAC(ap->mac_src); printk(" ARP IP SRC=%u.%u.%u.%u", myNIPQUAD(ap->ip_src)); printk(" ARP MAC DST="); print_MAC(ap->mac_dst); printk(" ARP IP DST=%u.%u.%u.%u", myNIPQUAD(ap->ip_dst)); } } out: printk("\n"); spin_unlock_bh(&ebt_log_lock); } static void ebt_log(const struct sk_buff *skb, unsigned int hooknr, const struct net_device *in, const struct net_device *out, const void *data, unsigned int datalen) { struct ebt_log_info *info = (struct ebt_log_info *)data; struct nf_loginfo li; li.type = NF_LOG_TYPE_LOG; li.u.log.level = info->loglevel; li.u.log.logflags = info->bitmask; nf_log_packet(PF_BRIDGE, hooknr, skb, in, out, &li, info->prefix); } static struct ebt_watcher log = { .name = EBT_LOG_WATCHER, .watcher = ebt_log, .check = ebt_log_check, .me = THIS_MODULE, }; static struct nf_logger ebt_log_logger = { .name = "ebt_log", .logfn = &ebt_log_packet, .me = THIS_MODULE, }; static int __init init(void) { int ret; ret = ebt_register_watcher(&log); if (ret < 0) return ret; if (nf_log_register(PF_BRIDGE, &ebt_log_logger) < 0) { printk(KERN_WARNING "ebt_log: not logging via system console " "since somebody else already registered for PF_INET\n"); /* we cannot make module load fail here, since otherwise * ebtables userspace would abort */ } return 0; } static void __exit fini(void) { nf_log_unregister_logger(&ebt_log_logger); ebt_unregister_watcher(&log); } module_init(init); module_exit(fini); MODULE_LICENSE("GPL");