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Commit 10151d7b authored by Pablo Neira Ayuso's avatar Pablo Neira Ayuso
Browse files

netfilter: nf_tables_bridge: use nft_set_pktinfo_ipv{4, 6}_validate 



Consolidate pktinfo setup and validation by using the new generic
functions so we converge to the netdev family codebase.

We only need a linear IPv4 and IPv6 header from the reject expression,
so move nft_bridge_iphdr_validate() and nft_bridge_ip6hdr_validate()
to net/bridge/netfilter/nft_reject_bridge.c.

Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent ddc8b602

include/net/netfilter/nf_tables_bridge.h

deleted100644 → 0
+0 −7
Original line number Diff line number Diff line 
#ifndef _NET_NF_TABLES_BRIDGE_H

#define _NET_NF_TABLES_BRIDGE_H



int nft_bridge_iphdr_validate(struct sk_buff *skb);

int nft_bridge_ip6hdr_validate(struct sk_buff *skb);



#endif /* _NET_NF_TABLES_BRIDGE_H */

net/bridge/netfilter/nf_tables_bridge.c

+2 −70
Original line number Diff line number Diff line
@@ -13,79 +13,11 @@ 
#include <linux/module.h>

#include <linux/netfilter_bridge.h>

#include <net/netfilter/nf_tables.h>

#include <net/netfilter/nf_tables_bridge.h>

#include <linux/ip.h>

#include <linux/ipv6.h>

#include <net/netfilter/nf_tables_ipv4.h>

#include <net/netfilter/nf_tables_ipv6.h>



int nft_bridge_iphdr_validate(struct sk_buff *skb)

{

	struct iphdr *iph;

	u32 len;



	if (!pskb_may_pull(skb, sizeof(struct iphdr)))

		return 0;



	iph = ip_hdr(skb);

	if (iph->ihl < 5 || iph->version != 4)

		return 0;



	len = ntohs(iph->tot_len);

	if (skb->len < len)

		return 0;

	else if (len < (iph->ihl*4))

		return 0;



	if (!pskb_may_pull(skb, iph->ihl*4))

		return 0;



	return 1;

}

EXPORT_SYMBOL_GPL(nft_bridge_iphdr_validate);



int nft_bridge_ip6hdr_validate(struct sk_buff *skb)

{

	struct ipv6hdr *hdr;

	u32 pkt_len;



	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))

		return 0;



	hdr = ipv6_hdr(skb);

	if (hdr->version != 6)

		return 0;



	pkt_len = ntohs(hdr->payload_len);

	if (pkt_len + sizeof(struct ipv6hdr) > skb->len)

		return 0;



	return 1;

}

EXPORT_SYMBOL_GPL(nft_bridge_ip6hdr_validate);



static inline void nft_bridge_set_pktinfo_ipv4(struct nft_pktinfo *pkt,

					       struct sk_buff *skb,

					       const struct nf_hook_state *state)

{

	if (nft_bridge_iphdr_validate(skb))

		nft_set_pktinfo_ipv4(pkt, skb, state);

	else

		nft_set_pktinfo_unspec(pkt, skb, state);

}



static inline void nft_bridge_set_pktinfo_ipv6(struct nft_pktinfo *pkt,

					       struct sk_buff *skb,

					       const struct nf_hook_state *state)

{

#if IS_ENABLED(CONFIG_IPV6)

	if (nft_bridge_ip6hdr_validate(skb) &&

	    nft_set_pktinfo_ipv6(pkt, skb, state) == 0)

		return;

#endif

	nft_set_pktinfo_unspec(pkt, skb, state);

}



static unsigned int

nft_do_chain_bridge(void *priv,

		    struct sk_buff *skb,
@@ -95,10 +27,10 @@ nft_do_chain_bridge(void *priv, 


	switch (eth_hdr(skb)->h_proto) {

	case htons(ETH_P_IP):

		nft_bridge_set_pktinfo_ipv4(&pkt, skb, state);

		nft_set_pktinfo_ipv4_validate(&pkt, skb, state);

		break;

	case htons(ETH_P_IPV6):

		nft_bridge_set_pktinfo_ipv6(&pkt, skb, state);

		nft_set_pktinfo_ipv6_validate(&pkt, skb, state);

		break;

	default:

		nft_set_pktinfo_unspec(&pkt, skb, state);

net/bridge/netfilter/nft_reject_bridge.c

+43 −1
Original line number Diff line number Diff line
@@ -14,7 +14,6 @@ 
#include <linux/netfilter/nf_tables.h>

#include <net/netfilter/nf_tables.h>

#include <net/netfilter/nft_reject.h>

#include <net/netfilter/nf_tables_bridge.h>

#include <net/netfilter/ipv4/nf_reject.h>

#include <net/netfilter/ipv6/nf_reject.h>

#include <linux/ip.h>
@@ -37,6 +36,30 @@ static void nft_reject_br_push_etherhdr(struct sk_buff *oldskb, 
	skb_pull(nskb, ETH_HLEN);

}



static int nft_bridge_iphdr_validate(struct sk_buff *skb)

{

	struct iphdr *iph;

	u32 len;



	if (!pskb_may_pull(skb, sizeof(struct iphdr)))

		return 0;



	iph = ip_hdr(skb);

	if (iph->ihl < 5 || iph->version != 4)

		return 0;



	len = ntohs(iph->tot_len);

	if (skb->len < len)

		return 0;

	else if (len < (iph->ihl*4))

		return 0;



	if (!pskb_may_pull(skb, iph->ihl*4))

		return 0;



	return 1;

}



/* We cannot use oldskb->dev, it can be either bridge device (NF_BRIDGE INPUT)

 * or the bridge port (NF_BRIDGE PREROUTING).

 */
@@ -143,6 +166,25 @@ static void nft_reject_br_send_v4_unreach(struct net *net, 
	br_forward(br_port_get_rcu(dev), nskb, false, true);

}



static int nft_bridge_ip6hdr_validate(struct sk_buff *skb)

{

	struct ipv6hdr *hdr;

	u32 pkt_len;



	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))

		return 0;



	hdr = ipv6_hdr(skb);

	if (hdr->version != 6)

		return 0;



	pkt_len = ntohs(hdr->payload_len);

	if (pkt_len + sizeof(struct ipv6hdr) > skb->len)

		return 0;



	return 1;

}



static void nft_reject_br_send_v6_tcp_reset(struct net *net,

					    struct sk_buff *oldskb,

					    const struct net_device *dev,