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- /*
- * ebt_log
- *
- * Authors:
- * Bart De Schuymer <bdschuym@pandora.be>
- * Harald Welte <laforge@netfilter.org>
- *
- * April, 2002
- *
- */
- #include <linux/module.h>
- #include <linux/ip.h>
- #include <linux/in.h>
- #include <linux/if_arp.h>
- #include <linux/spinlock.h>
- #include <net/netfilter/nf_log.h>
- #include <linux/ipv6.h>
- #include <net/ipv6.h>
- #include <linux/in6.h>
- #include <linux/netfilter/x_tables.h>
- #include <linux/netfilter_bridge/ebtables.h>
- #include <linux/netfilter_bridge/ebt_log.h>
- #include <linux/netfilter.h>
- static DEFINE_SPINLOCK(ebt_log_lock);
- static int ebt_log_tg_check(const struct xt_tgchk_param *par)
- {
- struct ebt_log_info *info = par->targinfo;
- 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
- {
- __be16 src;
- __be16 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_ports(const struct sk_buff *skb, uint8_t protocol, int offset)
- {
- if (protocol == IPPROTO_TCP ||
- protocol == IPPROTO_UDP ||
- protocol == IPPROTO_UDPLITE ||
- protocol == IPPROTO_SCTP ||
- protocol == IPPROTO_DCCP) {
- const struct tcpudphdr *pptr;
- struct tcpudphdr _ports;
- pptr = skb_header_pointer(skb, offset,
- sizeof(_ports), &_ports);
- if (pptr == NULL) {
- printk(" INCOMPLETE TCP/UDP header");
- return;
- }
- printk(" SPT=%u DPT=%u", ntohs(pptr->src), ntohs(pptr->dst));
- }
- }
- static void
- ebt_log_packet(struct net *net, u_int8_t 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;
- /* FIXME: Disabled from containers until syslog ns is supported */
- if (!net_eq(net, &init_net))
- return;
- spin_lock_bh(&ebt_log_lock);
- printk(KERN_SOH "%c%s IN=%s OUT=%s MAC source = %pM MAC dest = %pM proto = 0x%04x",
- '0' + loginfo->u.log.level, prefix,
- in ? in->name : "", out ? out->name : "",
- eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest,
- 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)) {
- const struct iphdr *ih;
- struct iphdr _iph;
- ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph);
- if (ih == NULL) {
- printk(" INCOMPLETE IP header");
- goto out;
- }
- printk(" IP SRC=%pI4 IP DST=%pI4, IP tos=0x%02X, IP proto=%d",
- &ih->saddr, &ih->daddr, ih->tos, ih->protocol);
- print_ports(skb, ih->protocol, ih->ihl*4);
- goto out;
- }
- #if IS_ENABLED(CONFIG_BRIDGE_EBT_IP6)
- if ((bitmask & EBT_LOG_IP6) && eth_hdr(skb)->h_proto ==
- htons(ETH_P_IPV6)) {
- const struct ipv6hdr *ih;
- struct ipv6hdr _iph;
- uint8_t nexthdr;
- __be16 frag_off;
- int offset_ph;
- ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph);
- if (ih == NULL) {
- printk(" INCOMPLETE IPv6 header");
- goto out;
- }
- printk(" IPv6 SRC=%pI6 IPv6 DST=%pI6, IPv6 priority=0x%01X, Next Header=%d",
- &ih->saddr, &ih->daddr, ih->priority, ih->nexthdr);
- nexthdr = ih->nexthdr;
- offset_ph = ipv6_skip_exthdr(skb, sizeof(_iph), &nexthdr, &frag_off);
- if (offset_ph == -1)
- goto out;
- print_ports(skb, nexthdr, offset_ph);
- goto out;
- }
- #endif
- if ((bitmask & EBT_LOG_ARP) &&
- ((eth_hdr(skb)->h_proto == htons(ETH_P_ARP)) ||
- (eth_hdr(skb)->h_proto == htons(ETH_P_RARP)))) {
- const struct arphdr *ah;
- struct arphdr _arph;
- 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(__be32)) {
- const struct arppayload *ap;
- struct arppayload _arpp;
- ap = skb_header_pointer(skb, sizeof(_arph),
- sizeof(_arpp), &_arpp);
- if (ap == NULL) {
- printk(" INCOMPLETE ARP payload");
- goto out;
- }
- printk(" ARP MAC SRC=%pM ARP IP SRC=%pI4 ARP MAC DST=%pM ARP IP DST=%pI4",
- ap->mac_src, ap->ip_src, ap->mac_dst, ap->ip_dst);
- }
- }
- out:
- printk("\n");
- spin_unlock_bh(&ebt_log_lock);
- }
- static unsigned int
- ebt_log_tg(struct sk_buff *skb, const struct xt_action_param *par)
- {
- const struct ebt_log_info *info = par->targinfo;
- struct nf_loginfo li;
- struct net *net = par->net;
- li.type = NF_LOG_TYPE_LOG;
- li.u.log.level = info->loglevel;
- li.u.log.logflags = info->bitmask;
- /* Remember that we have to use ebt_log_packet() not to break backward
- * compatibility. We cannot use the default bridge packet logger via
- * nf_log_packet() with NFT_LOG_TYPE_LOG here. --Pablo
- */
- if (info->bitmask & EBT_LOG_NFLOG)
- nf_log_packet(net, NFPROTO_BRIDGE, par->hooknum, skb,
- par->in, par->out, &li, "%s", info->prefix);
- else
- ebt_log_packet(net, NFPROTO_BRIDGE, par->hooknum, skb, par->in,
- par->out, &li, info->prefix);
- return EBT_CONTINUE;
- }
- static struct xt_target ebt_log_tg_reg __read_mostly = {
- .name = "log",
- .revision = 0,
- .family = NFPROTO_BRIDGE,
- .target = ebt_log_tg,
- .checkentry = ebt_log_tg_check,
- .targetsize = sizeof(struct ebt_log_info),
- .me = THIS_MODULE,
- };
- static int __init ebt_log_init(void)
- {
- return xt_register_target(&ebt_log_tg_reg);
- }
- static void __exit ebt_log_fini(void)
- {
- xt_unregister_target(&ebt_log_tg_reg);
- }
- module_init(ebt_log_init);
- module_exit(ebt_log_fini);
- MODULE_DESCRIPTION("Ebtables: Packet logging to syslog");
- MODULE_LICENSE("GPL");
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