#!/bin/bash

insert() {
    ebtables -t broute -I BROUTING -p ipv4 --ip-proto 17  --log --log-prefix 'ebtable/broute-BROUTING' --log-level debug --log-ip
    ebtables -t nat -I PREROUTING -p ipv4 --ip-proto 17  --log --log-prefix 'ebtable/nat-PREROUTE' --log-level debug --log-ip
    ebtables -t nat -I POSTROUTING -p ipv4 --ip-proto 17   --log --log-prefix 'ebtable/nat-POSTROUTE' --log-level debug --log-ip
    ebtables -t nat -I OUTPUT -p ipv4 --ip-proto 17  --log --log-prefix 'ebtable/nat-OUTPUT' --log-level debug --log-ip
    ebtables -t filter -I INPUT -p ipv4 --ip-proto 17  --log --log-prefix 'ebtable/filter-INPUT' --log-level debug --log-ip
    ebtables -t filter -I OUTPUT -p ipv4 --ip-proto 17  --log --log-prefix 'ebtable/filter-OUTPUT' --log-level debug --log-ip
    ebtables -t filter -I FORWARD -p ipv4 --ip-proto 17   --log --log-prefix 'ebtable/filter-FORWARD' --log-level debug --log-ip
}

delete() {
    ebtables -t broute -D BROUTING --log --log-prefix 'ebtable/broute-BROUTING' --log-level debug -p ipv4 --ip-proto 17 --log-ip
    ebtables -t nat -D PREROUTING --log --log-prefix 'ebtable/nat-PREROUTE' --log-level debug  -p ipv4 --ip-proto 17 --log-ip
    ebtables -t nat -D POSTROUTING --log --log-prefix 'ebtable/nat-POSTROUTE' --log-level debug  -p ipv4 --ip-proto 17 --log-ip
    ebtables -t nat -D OUTPUT --log --log-prefix 'ebtable/nat-OUTPUT' --log-level debug  -p ipv4 --ip-proto 17 --log-ip 
    ebtables -t filter -D INPUT --log --log-prefix 'ebtable/filter-INPUT' --log-level debug  -p ipv4 --ip-proto 17 --log-ip
    ebtables -t filter -D OUTPUT --log --log-prefix 'ebtable/filter-OUTPUT' --log-level debug  -p ipv4 --ip-proto 17  --log-ip
    ebtables -t filter -D FORWARD --log --log-prefix 'ebtable/filter-FORWARD' --log-level debug  -p ipv4 --ip-proto 17  --log-ip
}

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,
};

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 = xt_net(par);

	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, xt_hooknum(par), skb,
			      xt_in(par), xt_out(par), &li, "%s",
			      info->prefix);
	else
		ebt_log_packet(net, NFPROTO_BRIDGE, xt_hooknum(par), skb,
			       xt_in(par), xt_out(par), &li, info->prefix);
	return EBT_CONTINUE;
}


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) && !sysctl_nf_log_all_netns)
		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_DEFAULT_MASK;
//如果设置了控制选项（–log-ip），并且报文为IP报文，显示IP头部信息，以及尝试显示四层报文信息（print_ports）。
	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) {
			pr_cont(" INCOMPLETE IP header");
			goto out;
		}
		pr_cont(" 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;
	}
//对于ARP协议报文，如果设置了选项（–log-arp），显示ARP头部信息。对于Ethernet，另外显示报文信息，
//包括发送者（Sender）的MAC和IP地址，目标（Target）的MAC和IP地址。
	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) {
			pr_cont(" INCOMPLETE ARP header");
			goto out;
		}
		pr_cont(" 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) {
				pr_cont(" INCOMPLETE ARP payload");
				goto out;
			}
			pr_cont(" 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:
	pr_cont("\n");
	spin_unlock_bh(&ebt_log_lock);
}