[deliverable/linux.git] / net / bridge / netfilter / nft_reject_bridge.c

/*
 * Copyright (c) 2014 Pablo Neira Ayuso <pablo@netfilter.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/netlink.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nft_reject.h>
#include <net/netfilter/ipv4/nf_reject.h>
#include <net/netfilter/ipv6/nf_reject.h>
#include <linux/ip.h>
#include <net/ip.h>
#include <net/ip6_checksum.h>
#include <linux/netfilter_bridge.h>
#include "../br_private.h"

static void nft_reject_br_push_etherhdr(struct sk_buff *oldskb,
					struct sk_buff *nskb)
{
	struct ethhdr *eth;

	eth = (struct ethhdr *)skb_push(nskb, ETH_HLEN);
	skb_reset_mac_header(nskb);
	ether_addr_copy(eth->h_source, eth_hdr(oldskb)->h_dest);
	ether_addr_copy(eth->h_dest, eth_hdr(oldskb)->h_source);
	eth->h_proto = eth_hdr(oldskb)->h_proto;
	skb_pull(nskb, ETH_HLEN);
}

static int nft_reject_iphdr_validate(struct sk_buff *oldskb)
{
	struct iphdr *iph;
	u32 len;

	if (!pskb_may_pull(oldskb, sizeof(struct iphdr)))
		return 0;

	iph = ip_hdr(oldskb);
	if (iph->ihl < 5 || iph->version != 4)
		return 0;

	len = ntohs(iph->tot_len);
	if (oldskb->len < len)
		return 0;
	else if (len < (iph->ihl*4))
		return 0;

	if (!pskb_may_pull(oldskb, iph->ihl*4))
		return 0;

	return 1;
}

static void nft_reject_br_send_v4_tcp_reset(struct sk_buff *oldskb, int hook)
{
	struct sk_buff *nskb;
	struct iphdr *niph;
	const struct tcphdr *oth;
	struct tcphdr _oth;

	if (!nft_reject_iphdr_validate(oldskb))
		return;

	oth = nf_reject_ip_tcphdr_get(oldskb, &_oth, hook);
	if (!oth)
		return;

	nskb = alloc_skb(sizeof(struct iphdr) + sizeof(struct tcphdr) +
			 LL_MAX_HEADER, GFP_ATOMIC);
	if (!nskb)
		return;

	skb_reserve(nskb, LL_MAX_HEADER);
	niph = nf_reject_iphdr_put(nskb, oldskb, IPPROTO_TCP,
				   sysctl_ip_default_ttl);
	nf_reject_ip_tcphdr_put(nskb, oldskb, oth);
	niph->ttl	= sysctl_ip_default_ttl;
	niph->tot_len	= htons(nskb->len);
	ip_send_check(niph);

	nft_reject_br_push_etherhdr(oldskb, nskb);

	br_deliver(br_port_get_rcu(oldskb->dev), nskb);
}

static void nft_reject_br_send_v4_unreach(struct sk_buff *oldskb, int hook,
					  u8 code)
{
	struct sk_buff *nskb;
	struct iphdr *niph;
	struct icmphdr *icmph;
	unsigned int len;
	void *payload;
	__wsum csum;

	if (!nft_reject_iphdr_validate(oldskb))
		return;

	/* IP header checks: fragment. */
	if (ip_hdr(oldskb)->frag_off & htons(IP_OFFSET))
		return;

	/* RFC says return as much as we can without exceeding 576 bytes. */
	len = min_t(unsigned int, 536, oldskb->len);

	if (!pskb_may_pull(oldskb, len))
		return;

	if (nf_ip_checksum(oldskb, hook, ip_hdrlen(oldskb), 0))
		return;

	nskb = alloc_skb(sizeof(struct iphdr) + sizeof(struct icmphdr) +
			 LL_MAX_HEADER + len, GFP_ATOMIC);
	if (!nskb)
		return;

	skb_reserve(nskb, LL_MAX_HEADER);
	niph = nf_reject_iphdr_put(nskb, oldskb, IPPROTO_ICMP,
				   sysctl_ip_default_ttl);

	skb_reset_transport_header(nskb);
	icmph = (struct icmphdr *)skb_put(nskb, sizeof(struct icmphdr));
	memset(icmph, 0, sizeof(*icmph));
	icmph->type     = ICMP_DEST_UNREACH;
	icmph->code	= code;

	payload = skb_put(nskb, len);
	memcpy(payload, skb_network_header(oldskb), len);

	csum = csum_partial((void *)icmph, len + sizeof(struct icmphdr), 0);
	icmph->checksum = csum_fold(csum);

	niph->tot_len	= htons(nskb->len);
	ip_send_check(niph);

	nft_reject_br_push_etherhdr(oldskb, nskb);

	br_deliver(br_port_get_rcu(oldskb->dev), nskb);
}

static int nft_reject_ip6hdr_validate(struct sk_buff *oldskb)
{
	struct ipv6hdr *hdr;
	u32 pkt_len;

	if (!pskb_may_pull(oldskb, sizeof(struct ipv6hdr)))
		return 0;

	hdr = ipv6_hdr(oldskb);
	if (hdr->version != 6)
		return 0;

	pkt_len = ntohs(hdr->payload_len);
	if (pkt_len + sizeof(struct ipv6hdr) > oldskb->len)
		return 0;

	return 1;
}

static void nft_reject_br_send_v6_tcp_reset(struct net *net,
					    struct sk_buff *oldskb, int hook)
{
	struct sk_buff *nskb;
	const struct tcphdr *oth;
	struct tcphdr _oth;
	unsigned int otcplen;
	struct ipv6hdr *nip6h;

	if (!nft_reject_ip6hdr_validate(oldskb))
		return;

	oth = nf_reject_ip6_tcphdr_get(oldskb, &_oth, &otcplen, hook);
	if (!oth)
		return;

	nskb = alloc_skb(sizeof(struct ipv6hdr) + sizeof(struct tcphdr) +
			 LL_MAX_HEADER, GFP_ATOMIC);
	if (!nskb)
		return;

	skb_reserve(nskb, LL_MAX_HEADER);
	nip6h = nf_reject_ip6hdr_put(nskb, oldskb, IPPROTO_TCP,
				     net->ipv6.devconf_all->hop_limit);
	nf_reject_ip6_tcphdr_put(nskb, oldskb, oth, otcplen);
	nip6h->payload_len = htons(nskb->len - sizeof(struct ipv6hdr));

	nft_reject_br_push_etherhdr(oldskb, nskb);

	br_deliver(br_port_get_rcu(oldskb->dev), nskb);
}

static void nft_reject_br_send_v6_unreach(struct net *net,
					  struct sk_buff *oldskb, int hook,
					  u8 code)
{
	struct sk_buff *nskb;
	struct ipv6hdr *nip6h;
	struct icmp6hdr *icmp6h;
	unsigned int len;
	void *payload;

	if (!nft_reject_ip6hdr_validate(oldskb))
		return;

	/* Include "As much of invoking packet as possible without the ICMPv6
	 * packet exceeding the minimum IPv6 MTU" in the ICMP payload.
	 */
	len = min_t(unsigned int, 1220, oldskb->len);

	if (!pskb_may_pull(oldskb, len))
		return;

	nskb = alloc_skb(sizeof(struct iphdr) + sizeof(struct icmp6hdr) +
			 LL_MAX_HEADER + len, GFP_ATOMIC);
	if (!nskb)
		return;

	skb_reserve(nskb, LL_MAX_HEADER);
	nip6h = nf_reject_ip6hdr_put(nskb, oldskb, IPPROTO_ICMPV6,
				     net->ipv6.devconf_all->hop_limit);

	skb_reset_transport_header(nskb);
	icmp6h = (struct icmp6hdr *)skb_put(nskb, sizeof(struct icmp6hdr));
	memset(icmp6h, 0, sizeof(*icmp6h));
	icmp6h->icmp6_type = ICMPV6_DEST_UNREACH;
	icmp6h->icmp6_code = code;

	payload = skb_put(nskb, len);
	memcpy(payload, skb_network_header(oldskb), len);
	nip6h->payload_len = htons(nskb->len - sizeof(struct ipv6hdr));

	icmp6h->icmp6_cksum =
		csum_ipv6_magic(&nip6h->saddr, &nip6h->daddr,
				nskb->len - sizeof(struct ipv6hdr),
				IPPROTO_ICMPV6,
				csum_partial(icmp6h,
					     nskb->len - sizeof(struct ipv6hdr),
					     0));

	nft_reject_br_push_etherhdr(oldskb, nskb);

	br_deliver(br_port_get_rcu(oldskb->dev), nskb);
}

static void nft_reject_bridge_eval(const struct nft_expr *expr,
				 struct nft_data data[NFT_REG_MAX + 1],
				 const struct nft_pktinfo *pkt)
{
	struct nft_reject *priv = nft_expr_priv(expr);
	struct net *net = dev_net((pkt->in != NULL) ? pkt->in : pkt->out);
	const unsigned char *dest = eth_hdr(pkt->skb)->h_dest;

	if (is_broadcast_ether_addr(dest) ||
	    is_multicast_ether_addr(dest))
		goto out;

	switch (eth_hdr(pkt->skb)->h_proto) {
	case htons(ETH_P_IP):
		switch (priv->type) {
		case NFT_REJECT_ICMP_UNREACH:
			nft_reject_br_send_v4_unreach(pkt->skb,
						      pkt->ops->hooknum,
						      priv->icmp_code);
			break;
		case NFT_REJECT_TCP_RST:
			nft_reject_br_send_v4_tcp_reset(pkt->skb,
							pkt->ops->hooknum);
			break;
		case NFT_REJECT_ICMPX_UNREACH:
			nft_reject_br_send_v4_unreach(pkt->skb,
						      pkt->ops->hooknum,
						      nft_reject_icmp_code(priv->icmp_code));
			break;
		}
		break;
	case htons(ETH_P_IPV6):
		switch (priv->type) {
		case NFT_REJECT_ICMP_UNREACH:
			nft_reject_br_send_v6_unreach(net, pkt->skb,
						      pkt->ops->hooknum,
						      priv->icmp_code);
			break;
		case NFT_REJECT_TCP_RST:
			nft_reject_br_send_v6_tcp_reset(net, pkt->skb,
							pkt->ops->hooknum);
			break;
		case NFT_REJECT_ICMPX_UNREACH:
			nft_reject_br_send_v6_unreach(net, pkt->skb,
						      pkt->ops->hooknum,
						      nft_reject_icmpv6_code(priv->icmp_code));
			break;
		}
		break;
	default:
		/* No explicit way to reject this protocol, drop it. */
		break;
	}
out:
	data[NFT_REG_VERDICT].verdict = NF_DROP;
}

static int nft_reject_bridge_validate_hooks(const struct nft_chain *chain)
{
	struct nft_base_chain *basechain;

	if (chain->flags & NFT_BASE_CHAIN) {
		basechain = nft_base_chain(chain);

		switch (basechain->ops[0].hooknum) {
		case NF_BR_PRE_ROUTING:
		case NF_BR_LOCAL_IN:
			break;
		default:
			return -EOPNOTSUPP;
		}
	}
	return 0;
}

static int nft_reject_bridge_init(const struct nft_ctx *ctx,
				  const struct nft_expr *expr,
				  const struct nlattr * const tb[])
{
	struct nft_reject *priv = nft_expr_priv(expr);
	int icmp_code, err;

	err = nft_reject_bridge_validate_hooks(ctx->chain);
	if (err < 0)
		return err;

	if (tb[NFTA_REJECT_TYPE] == NULL)
		return -EINVAL;

	priv->type = ntohl(nla_get_be32(tb[NFTA_REJECT_TYPE]));
	switch (priv->type) {
	case NFT_REJECT_ICMP_UNREACH:
	case NFT_REJECT_ICMPX_UNREACH:
		if (tb[NFTA_REJECT_ICMP_CODE] == NULL)
			return -EINVAL;

		icmp_code = nla_get_u8(tb[NFTA_REJECT_ICMP_CODE]);
		if (priv->type == NFT_REJECT_ICMPX_UNREACH &&
		    icmp_code > NFT_REJECT_ICMPX_MAX)
			return -EINVAL;

		priv->icmp_code = icmp_code;
		break;
	case NFT_REJECT_TCP_RST:
		break;
	default:
		return -EINVAL;
	}
	return 0;
}

static int nft_reject_bridge_dump(struct sk_buff *skb,
				  const struct nft_expr *expr)
{
	const struct nft_reject *priv = nft_expr_priv(expr);

	if (nla_put_be32(skb, NFTA_REJECT_TYPE, htonl(priv->type)))
		goto nla_put_failure;

	switch (priv->type) {
	case NFT_REJECT_ICMP_UNREACH:
	case NFT_REJECT_ICMPX_UNREACH:
		if (nla_put_u8(skb, NFTA_REJECT_ICMP_CODE, priv->icmp_code))
			goto nla_put_failure;
		break;
	}

	return 0;

nla_put_failure:
	return -1;
}

static int nft_reject_bridge_validate(const struct nft_ctx *ctx,
				      const struct nft_expr *expr,
				      const struct nft_data **data)
{
	return nft_reject_bridge_validate_hooks(ctx->chain);
}

static struct nft_expr_type nft_reject_bridge_type;
static const struct nft_expr_ops nft_reject_bridge_ops = {
	.type		= &nft_reject_bridge_type,
	.size		= NFT_EXPR_SIZE(sizeof(struct nft_reject)),
	.eval		= nft_reject_bridge_eval,
	.init		= nft_reject_bridge_init,
	.dump		= nft_reject_bridge_dump,
	.validate	= nft_reject_bridge_validate,
};

static struct nft_expr_type nft_reject_bridge_type __read_mostly = {
	.family		= NFPROTO_BRIDGE,
	.name		= "reject",
	.ops		= &nft_reject_bridge_ops,
	.policy		= nft_reject_policy,
	.maxattr	= NFTA_REJECT_MAX,
	.owner		= THIS_MODULE,
};

static int __init nft_reject_bridge_module_init(void)
{
	return nft_register_expr(&nft_reject_bridge_type);
}

static void __exit nft_reject_bridge_module_exit(void)
{
	nft_unregister_expr(&nft_reject_bridge_type);
}

module_init(nft_reject_bridge_module_init);
module_exit(nft_reject_bridge_module_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
MODULE_ALIAS_NFT_AF_EXPR(AF_BRIDGE, "reject");
Commit	Line	Data
85f5b308 PNA	1	/*
	2	* Copyright (c) 2014 Pablo Neira Ayuso <pablo@netfilter.org>
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2 as
	6	* published by the Free Software Foundation.
	7	*/
	8
	9	#include <linux/kernel.h>
	10	#include <linux/init.h>
	11	#include <linux/module.h>
	12	#include <linux/netlink.h>
	13	#include <linux/netfilter.h>
	14	#include <linux/netfilter/nf_tables.h>
	15	#include <net/netfilter/nf_tables.h>
	16	#include <net/netfilter/nft_reject.h>
51b0a5d8 PNA	17	#include <net/netfilter/ipv4/nf_reject.h>
51b0a5d8 PNA	18	#include <net/netfilter/ipv6/nf_reject.h>
523b929d PNA	19	#include <linux/ip.h>
523b929d PNA	20	#include <net/ip.h>
c1207c04	21	#include <net/ip6_checksum.h>
127917c2	22	#include <linux/netfilter_bridge.h>
523b929d PNA	23	#include "../br_private.h"
	24
	25	static void nft_reject_br_push_etherhdr(struct sk_buff *oldskb,
	26	struct sk_buff *nskb)
	27	{
	28	struct ethhdr *eth;
	29
	30	eth = (struct ethhdr *)skb_push(nskb, ETH_HLEN);
	31	skb_reset_mac_header(nskb);
	32	ether_addr_copy(eth->h_source, eth_hdr(oldskb)->h_dest);
	33	ether_addr_copy(eth->h_dest, eth_hdr(oldskb)->h_source);
	34	eth->h_proto = eth_hdr(oldskb)->h_proto;
	35	skb_pull(nskb, ETH_HLEN);
	36	}
	37
	38	static int nft_reject_iphdr_validate(struct sk_buff *oldskb)
	39	{
	40	struct iphdr *iph;
	41	u32 len;
	42
	43	if (!pskb_may_pull(oldskb, sizeof(struct iphdr)))
	44	return 0;
	45
	46	iph = ip_hdr(oldskb);
	47	if (iph->ihl < 5 \|\| iph->version != 4)
	48	return 0;
	49
	50	len = ntohs(iph->tot_len);
	51	if (oldskb->len < len)
	52	return 0;
	53	else if (len < (iph->ihl*4))
	54	return 0;
	55
	56	if (!pskb_may_pull(oldskb, iph->ihl*4))
	57	return 0;
	58
	59	return 1;
	60	}
	61
	62	static void nft_reject_br_send_v4_tcp_reset(struct sk_buff *oldskb, int hook)
	63	{
	64	struct sk_buff *nskb;
	65	struct iphdr *niph;
	66	const struct tcphdr *oth;
	67	struct tcphdr _oth;
	68
	69	if (!nft_reject_iphdr_validate(oldskb))
	70	return;
	71
	72	oth = nf_reject_ip_tcphdr_get(oldskb, &_oth, hook);
	73	if (!oth)
	74	return;
	75
	76	nskb = alloc_skb(sizeof(struct iphdr) + sizeof(struct tcphdr) +
	77	LL_MAX_HEADER, GFP_ATOMIC);
	78	if (!nskb)
	79	return;
	80
	81	skb_reserve(nskb, LL_MAX_HEADER);
	82	niph = nf_reject_iphdr_put(nskb, oldskb, IPPROTO_TCP,
	83	sysctl_ip_default_ttl);
	84	nf_reject_ip_tcphdr_put(nskb, oldskb, oth);
	85	niph->ttl = sysctl_ip_default_ttl;
	86	niph->tot_len = htons(nskb->len);
87	ip_send_check(niph);
88
89	nft_reject_br_push_etherhdr(oldskb, nskb);
90
91	br_deliver(br_port_get_rcu(oldskb->dev), nskb);
92	}
93
94	static void nft_reject_br_send_v4_unreach(struct sk_buff *oldskb, int hook,
95	u8 code)
96	{
97	struct sk_buff *nskb;
98	struct iphdr *niph;
99	struct icmphdr *icmph;
100	unsigned int len;
101	void *payload;
102	__wsum csum;
103
104	if (!nft_reject_iphdr_validate(oldskb))
105	return;
106
107	/* IP header checks: fragment. */
108	if (ip_hdr(oldskb)->frag_off & htons(IP_OFFSET))
109	return;
110
111	/* RFC says return as much as we can without exceeding 576 bytes. */
112	len = min_t(unsigned int, 536, oldskb->len);
113
114	if (!pskb_may_pull(oldskb, len))
115	return;
116
117	if (nf_ip_checksum(oldskb, hook, ip_hdrlen(oldskb), 0))
118	return;
119
120	nskb = alloc_skb(sizeof(struct iphdr) + sizeof(struct icmphdr) +
121	LL_MAX_HEADER + len, GFP_ATOMIC);
122	if (!nskb)
123	return;
124
125	skb_reserve(nskb, LL_MAX_HEADER);
126	niph = nf_reject_iphdr_put(nskb, oldskb, IPPROTO_ICMP,
127	sysctl_ip_default_ttl);
128
129	skb_reset_transport_header(nskb);
130	icmph = (struct icmphdr *)skb_put(nskb, sizeof(struct icmphdr));
131	memset(icmph, 0, sizeof(*icmph));
132	icmph->type = ICMP_DEST_UNREACH;
133	icmph->code = code;
134
135	payload = skb_put(nskb, len);
136	memcpy(payload, skb_network_header(oldskb), len);
137
138	csum = csum_partial((void *)icmph, len + sizeof(struct icmphdr), 0);
139	icmph->checksum = csum_fold(csum);
140
141	niph->tot_len = htons(nskb->len);
142	ip_send_check(niph);
143
144	nft_reject_br_push_etherhdr(oldskb, nskb);
145
146	br_deliver(br_port_get_rcu(oldskb->dev), nskb);
147	}
148
149	static int nft_reject_ip6hdr_validate(struct sk_buff *oldskb)
150	{
151	struct ipv6hdr *hdr;
152	u32 pkt_len;
153
154	if (!pskb_may_pull(oldskb, sizeof(struct ipv6hdr)))
155	return 0;
156
157	hdr = ipv6_hdr(oldskb);
158	if (hdr->version != 6)
159	return 0;
160
161	pkt_len = ntohs(hdr->payload_len);
162	if (pkt_len + sizeof(struct ipv6hdr) > oldskb->len)
163	return 0;
164
165	return 1;
166	}
167
168	static void nft_reject_br_send_v6_tcp_reset(struct net *net,
169	struct sk_buff *oldskb, int hook)
170	{
171	struct sk_buff *nskb;
172	const struct tcphdr *oth;
173	struct tcphdr _oth;
174	unsigned int otcplen;
175	struct ipv6hdr *nip6h;
176
177	if (!nft_reject_ip6hdr_validate(oldskb))
178	return;
179
180	oth = nf_reject_ip6_tcphdr_get(oldskb, &_oth, &otcplen, hook);
181	if (!oth)
182	return;
183
184	nskb = alloc_skb(sizeof(struct ipv6hdr) + sizeof(struct tcphdr) +
185	LL_MAX_HEADER, GFP_ATOMIC);
186	if (!nskb)
187	return;
188
189	skb_reserve(nskb, LL_MAX_HEADER);
190	nip6h = nf_reject_ip6hdr_put(nskb, oldskb, IPPROTO_TCP,
191	net->ipv6.devconf_all->hop_limit);
192	nf_reject_ip6_tcphdr_put(nskb, oldskb, oth, otcplen);
193	nip6h->payload_len = htons(nskb->len - sizeof(struct ipv6hdr));
194
195	nft_reject_br_push_etherhdr(oldskb, nskb);
196
197	br_deliver(br_port_get_rcu(oldskb->dev), nskb);
198	}
199
200	static void nft_reject_br_send_v6_unreach(struct net *net,
201	struct sk_buff *oldskb, int hook,
202	u8 code)
203	{
204	struct sk_buff *nskb;
205	struct ipv6hdr *nip6h;
206	struct icmp6hdr *icmp6h;
207	unsigned int len;
208	void *payload;
209
210	if (!nft_reject_ip6hdr_validate(oldskb))
211	return;
212
213	/* Include "As much of invoking packet as possible without the ICMPv6
214	* packet exceeding the minimum IPv6 MTU" in the ICMP payload.
215	*/
216	len = min_t(unsigned int, 1220, oldskb->len);
217
218	if (!pskb_may_pull(oldskb, len))
219	return;
220
221	nskb = alloc_skb(sizeof(struct iphdr) + sizeof(struct icmp6hdr) +
222	LL_MAX_HEADER + len, GFP_ATOMIC);
223	if (!nskb)
224	return;
225
226	skb_reserve(nskb, LL_MAX_HEADER);
227	nip6h = nf_reject_ip6hdr_put(nskb, oldskb, IPPROTO_ICMPV6,
228	net->ipv6.devconf_all->hop_limit);
229
230	skb_reset_transport_header(nskb);
231	icmp6h = (struct icmp6hdr *)skb_put(nskb, sizeof(struct icmp6hdr));
232	memset(icmp6h, 0, sizeof(*icmp6h));
233	icmp6h->icmp6_type = ICMPV6_DEST_UNREACH;
234	icmp6h->icmp6_code = code;
235
236	payload = skb_put(nskb, len);
237	memcpy(payload, skb_network_header(oldskb), len);
238	nip6h->payload_len = htons(nskb->len - sizeof(struct ipv6hdr));
239
240	icmp6h->icmp6_cksum =
241	csum_ipv6_magic(&nip6h->saddr, &nip6h->daddr,
242	nskb->len - sizeof(struct ipv6hdr),
243	IPPROTO_ICMPV6,
244	csum_partial(icmp6h,
245	nskb->len - sizeof(struct ipv6hdr),
246	0));
247
248	nft_reject_br_push_etherhdr(oldskb, nskb);
249
250	br_deliver(br_port_get_rcu(oldskb->dev), nskb);
251	}
85f5b308 PNA	252
	253	static void nft_reject_bridge_eval(const struct nft_expr *expr,
	254	struct nft_data data[NFT_REG_MAX + 1],
	255	const struct nft_pktinfo *pkt)
	256	{
51b0a5d8 PNA	257	struct nft_reject *priv = nft_expr_priv(expr);
51b0a5d8 PNA	258	struct net *net = dev_net((pkt->in != NULL) ? pkt->in : pkt->out);
523b929d PNA	259	const unsigned char *dest = eth_hdr(pkt->skb)->h_dest;
	260
	261	if (is_broadcast_ether_addr(dest) \|\|
	262	is_multicast_ether_addr(dest))
	263	goto out;
51b0a5d8	264
85f5b308 PNA	265	switch (eth_hdr(pkt->skb)->h_proto) {
85f5b308 PNA	266	case htons(ETH_P_IP):
51b0a5d8 PNA	267	switch (priv->type) {
51b0a5d8 PNA	268	case NFT_REJECT_ICMP_UNREACH:
523b929d PNA	269	nft_reject_br_send_v4_unreach(pkt->skb,
	270	pkt->ops->hooknum,
	271	priv->icmp_code);
51b0a5d8 PNA	272	break;
51b0a5d8 PNA	273	case NFT_REJECT_TCP_RST:
523b929d PNA	274	nft_reject_br_send_v4_tcp_reset(pkt->skb,
523b929d PNA	275	pkt->ops->hooknum);
51b0a5d8 PNA	276	break;
51b0a5d8 PNA	277	case NFT_REJECT_ICMPX_UNREACH:
523b929d PNA	278	nft_reject_br_send_v4_unreach(pkt->skb,
	279	pkt->ops->hooknum,
	280	nft_reject_icmp_code(priv->icmp_code));
51b0a5d8 PNA	281	break;
	282	}
	283	break;
85f5b308	284	case htons(ETH_P_IPV6):
51b0a5d8 PNA	285	switch (priv->type) {
51b0a5d8 PNA	286	case NFT_REJECT_ICMP_UNREACH:
523b929d PNA	287	nft_reject_br_send_v6_unreach(net, pkt->skb,
	288	pkt->ops->hooknum,
	289	priv->icmp_code);
51b0a5d8 PNA	290	break;
51b0a5d8 PNA	291	case NFT_REJECT_TCP_RST:
523b929d PNA	292	nft_reject_br_send_v6_tcp_reset(net, pkt->skb,
523b929d PNA	293	pkt->ops->hooknum);
51b0a5d8 PNA	294	break;
51b0a5d8 PNA	295	case NFT_REJECT_ICMPX_UNREACH:
523b929d PNA	296	nft_reject_br_send_v6_unreach(net, pkt->skb,
	297	pkt->ops->hooknum,
	298	nft_reject_icmpv6_code(priv->icmp_code));
51b0a5d8 PNA	299	break;
	300	}
	301	break;
85f5b308 PNA	302	default:
85f5b308 PNA	303	/* No explicit way to reject this protocol, drop it. */
85f5b308 PNA	304	break;
85f5b308 PNA	305	}
523b929d	306	out:
51b0a5d8 PNA	307	data[NFT_REG_VERDICT].verdict = NF_DROP;
	308	}
	309
127917c2 PNA	310	static int nft_reject_bridge_validate_hooks(const struct nft_chain *chain)
	311	{
	312	struct nft_base_chain *basechain;
	313
	314	if (chain->flags & NFT_BASE_CHAIN) {
	315	basechain = nft_base_chain(chain);
	316
	317	switch (basechain->ops[0].hooknum) {
	318	case NF_BR_PRE_ROUTING:
	319	case NF_BR_LOCAL_IN:
	320	break;
	321	default:
	322	return -EOPNOTSUPP;
	323	}
	324	}
	325	return 0;
	326	}
	327
51b0a5d8 PNA	328	static int nft_reject_bridge_init(const struct nft_ctx *ctx,
	329	const struct nft_expr *expr,
	330	const struct nlattr * const tb[])
	331	{
	332	struct nft_reject *priv = nft_expr_priv(expr);
127917c2 PNA	333	int icmp_code, err;
	334
	335	err = nft_reject_bridge_validate_hooks(ctx->chain);
	336	if (err < 0)
	337	return err;
51b0a5d8 PNA	338
	339	if (tb[NFTA_REJECT_TYPE] == NULL)
	340	return -EINVAL;
	341
	342	priv->type = ntohl(nla_get_be32(tb[NFTA_REJECT_TYPE]));
	343	switch (priv->type) {
	344	case NFT_REJECT_ICMP_UNREACH:
	345	case NFT_REJECT_ICMPX_UNREACH:
	346	if (tb[NFTA_REJECT_ICMP_CODE] == NULL)
	347	return -EINVAL;
	348
	349	icmp_code = nla_get_u8(tb[NFTA_REJECT_ICMP_CODE]);
	350	if (priv->type == NFT_REJECT_ICMPX_UNREACH &&
	351	icmp_code > NFT_REJECT_ICMPX_MAX)
	352	return -EINVAL;
	353
	354	priv->icmp_code = icmp_code;
	355	break;
	356	case NFT_REJECT_TCP_RST:
	357	break;
	358	default:
	359	return -EINVAL;
	360	}
	361	return 0;
	362	}
	363
	364	static int nft_reject_bridge_dump(struct sk_buff *skb,
	365	const struct nft_expr *expr)
	366	{
	367	const struct nft_reject *priv = nft_expr_priv(expr);
	368
	369	if (nla_put_be32(skb, NFTA_REJECT_TYPE, htonl(priv->type)))
	370	goto nla_put_failure;
	371
	372	switch (priv->type) {
	373	case NFT_REJECT_ICMP_UNREACH:
	374	case NFT_REJECT_ICMPX_UNREACH:
	375	if (nla_put_u8(skb, NFTA_REJECT_ICMP_CODE, priv->icmp_code))
	376	goto nla_put_failure;
	377	break;
	378	}
	379
	380	return 0;
	381
	382	nla_put_failure:
	383	return -1;
85f5b308 PNA	384	}
85f5b308 PNA	385
127917c2 PNA	386	static int nft_reject_bridge_validate(const struct nft_ctx *ctx,
	387	const struct nft_expr *expr,
	388	const struct nft_data **data)
	389	{
	390	return nft_reject_bridge_validate_hooks(ctx->chain);
	391	}
	392
85f5b308 PNA	393	static struct nft_expr_type nft_reject_bridge_type;
	394	static const struct nft_expr_ops nft_reject_bridge_ops = {
	395	.type = &nft_reject_bridge_type,
	396	.size = NFT_EXPR_SIZE(sizeof(struct nft_reject)),
	397	.eval = nft_reject_bridge_eval,
51b0a5d8 PNA	398	.init = nft_reject_bridge_init,
51b0a5d8 PNA	399	.dump = nft_reject_bridge_dump,
127917c2	400	.validate = nft_reject_bridge_validate,
85f5b308 PNA	401	};
	402
	403	static struct nft_expr_type nft_reject_bridge_type __read_mostly = {
	404	.family = NFPROTO_BRIDGE,
	405	.name = "reject",
	406	.ops = &nft_reject_bridge_ops,
	407	.policy = nft_reject_policy,
	408	.maxattr = NFTA_REJECT_MAX,
	409	.owner = THIS_MODULE,
	410	};
	411
	412	static int __init nft_reject_bridge_module_init(void)
	413	{
	414	return nft_register_expr(&nft_reject_bridge_type);
	415	}
	416
	417	static void __exit nft_reject_bridge_module_exit(void)
	418	{
	419	nft_unregister_expr(&nft_reject_bridge_type);
	420	}
	421
	422	module_init(nft_reject_bridge_module_init);
	423	module_exit(nft_reject_bridge_module_exit);
	424
	425	MODULE_LICENSE("GPL");
	426	MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
	427	MODULE_ALIAS_NFT_AF_EXPR(AF_BRIDGE, "reject");