6 files changed, 280 insertions, 192 deletions

diff --git a/include/net/netfilter/ipv4/nf_reject.h b/include/net/netfilter/ipv4/nf_reject.h
index 40e0e0623f46..0d8ff84a2588 100644
--- a/include/net/netfilter/ipv4/nf_reject.h
+++ b/include/net/netfilter/ipv4/nf_reject.h
@@ -18,4 +18,14 @@ struct iphdr *nf_reject_iphdr_put(struct sk_buff *nskb,
 void nf_reject_ip_tcphdr_put(struct sk_buff *nskb, const struct sk_buff *oldskb,
 			     const struct tcphdr *oth);
 
+struct sk_buff *nf_reject_skb_v4_unreach(struct net *net,
+                                         struct sk_buff *oldskb,
+                                         const struct net_device *dev,
+                                         int hook, u8 code);
+struct sk_buff *nf_reject_skb_v4_tcp_reset(struct net *net,
+					   struct sk_buff *oldskb,
+					   const struct net_device *dev,
+					   int hook);
+
+
 #endif /* _IPV4_NF_REJECT_H */
diff --git a/include/net/netfilter/ipv6/nf_reject.h b/include/net/netfilter/ipv6/nf_reject.h
index 4a3ef9ebdf6f..edcf6d1cd316 100644
--- a/include/net/netfilter/ipv6/nf_reject.h
+++ b/include/net/netfilter/ipv6/nf_reject.h
@@ -20,4 +20,13 @@ void nf_reject_ip6_tcphdr_put(struct sk_buff *nskb,
 			      const struct sk_buff *oldskb,
 			      const struct tcphdr *oth, unsigned int otcplen);
 
+struct sk_buff *nf_reject_skb_v6_tcp_reset(struct net *net,
+					   struct sk_buff *oldskb,
+					   const struct net_device *dev,
+					   int hook);
+struct sk_buff *nf_reject_skb_v6_unreach(struct net *net,
+					 struct sk_buff *oldskb,
+					 const struct net_device *dev,
+					 int hook, u8 code);
+
 #endif /* _IPV6_NF_REJECT_H */
diff --git a/net/bridge/netfilter/Kconfig b/net/bridge/netfilter/Kconfig
index 5040fe43f4b4..e4d287afc2c9 100644
--- a/net/bridge/netfilter/Kconfig
+++ b/net/bridge/netfilter/Kconfig
@@ -17,7 +17,7 @@ config NFT_BRIDGE_META
 
 config NFT_BRIDGE_REJECT
 	tristate "Netfilter nf_tables bridge reject support"
-	depends on NFT_REJECT && NFT_REJECT_IPV4 && NFT_REJECT_IPV6
+	depends on NFT_REJECT
 	help
 	  Add support to reject packets.
 
diff --git a/net/bridge/netfilter/nft_reject_bridge.c b/net/bridge/netfilter/nft_reject_bridge.c
index deae2c9a0f69..25ca7723c6c2 100644
--- a/net/bridge/netfilter/nft_reject_bridge.c
+++ b/net/bridge/netfilter/nft_reject_bridge.c
@@ -39,30 +39,6 @@ static void nft_reject_br_push_etherhdr(struct sk_buff *oldskb,
 	}
 }
 
-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).
  */
@@ -72,29 +48,11 @@ static void nft_reject_br_send_v4_tcp_reset(struct net *net,
 					    int hook)
 {
 	struct sk_buff *nskb;
-	struct iphdr *niph;
-	const struct tcphdr *oth;
-	struct tcphdr _oth;
 
-	if (!nft_bridge_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);
+	nskb = nf_reject_skb_v4_tcp_reset(net, oldskb, dev, hook);
 	if (!nskb)
 		return;
 
-	skb_reserve(nskb, LL_MAX_HEADER);
-	niph = nf_reject_iphdr_put(nskb, oldskb, IPPROTO_TCP,
-				   net->ipv4.sysctl_ip_default_ttl);
-	nf_reject_ip_tcphdr_put(nskb, oldskb, oth);
-	niph->tot_len = htons(nskb->len);
-	ip_send_check(niph);
-
 	nft_reject_br_push_etherhdr(oldskb, nskb);
 
 	br_forward(br_port_get_rcu(dev), nskb, false, true);
@@ -106,139 +64,32 @@ static void nft_reject_br_send_v4_unreach(struct net *net,
 					  int hook, u8 code)
 {
 	struct sk_buff *nskb;
-	struct iphdr *niph;
-	struct icmphdr *icmph;
-	unsigned int len;
-	__wsum csum;
-	u8 proto;
-
-	if (!nft_bridge_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 (pskb_trim_rcsum(oldskb, ntohs(ip_hdr(oldskb)->tot_len)))
-		return;
-
-	proto = ip_hdr(oldskb)->protocol;
-
-	if (!skb_csum_unnecessary(oldskb) &&
-	    nf_reject_verify_csum(proto) &&
-	    nf_ip_checksum(oldskb, hook, ip_hdrlen(oldskb), proto))
-		return;
-
-	nskb = alloc_skb(sizeof(struct iphdr) + sizeof(struct icmphdr) +
-			 LL_MAX_HEADER + len, GFP_ATOMIC);
+	nskb = nf_reject_skb_v4_unreach(net, oldskb, dev, hook, code);
 	if (!nskb)
 		return;
 
-	skb_reserve(nskb, LL_MAX_HEADER);
-	niph = nf_reject_iphdr_put(nskb, oldskb, IPPROTO_ICMP,
-				   net->ipv4.sysctl_ip_default_ttl);
-
-	skb_reset_transport_header(nskb);
-	icmph = skb_put_zero(nskb, sizeof(struct icmphdr));
-	icmph->type     = ICMP_DEST_UNREACH;
-	icmph->code	= code;
-
-	skb_put_data(nskb, 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_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,
 					    int hook)
 {
 	struct sk_buff *nskb;
-	const struct tcphdr *oth;
-	struct tcphdr _oth;
-	unsigned int otcplen;
-	struct ipv6hdr *nip6h;
-
-	if (!nft_bridge_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);
+	nskb = nf_reject_skb_v6_tcp_reset(net, oldskb, dev, hook);
 	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_forward(br_port_get_rcu(dev), nskb, false, true);
 }
 
-static bool reject6_br_csum_ok(struct sk_buff *skb, int hook)
-{
-	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
-	int thoff;
-	__be16 fo;
-	u8 proto = ip6h->nexthdr;
-
-	if (skb_csum_unnecessary(skb))
-		return true;
-
-	if (ip6h->payload_len &&
-	    pskb_trim_rcsum(skb, ntohs(ip6h->payload_len) + sizeof(*ip6h)))
-		return false;
-
-	ip6h = ipv6_hdr(skb);
-	thoff = ipv6_skip_exthdr(skb, ((u8*)(ip6h+1) - skb->data), &proto, &fo);
-	if (thoff < 0 || thoff >= skb->len || (fo & htons(~0x7)) != 0)
-		return false;
-
-	if (!nf_reject_verify_csum(proto))
-		return true;
-
-	return nf_ip6_checksum(skb, hook, thoff, proto) == 0;
-}
 
 static void nft_reject_br_send_v6_unreach(struct net *net,
 					  struct sk_buff *oldskb,
@@ -246,49 +97,11 @@ static void nft_reject_br_send_v6_unreach(struct net *net,
 					  int hook, u8 code)
 {
 	struct sk_buff *nskb;
-	struct ipv6hdr *nip6h;
-	struct icmp6hdr *icmp6h;
-	unsigned int len;
-
-	if (!nft_bridge_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;
 
-	if (!reject6_br_csum_ok(oldskb, hook))
-		return;
-
-	nskb = alloc_skb(sizeof(struct ipv6hdr) + sizeof(struct icmp6hdr) +
-			 LL_MAX_HEADER + len, GFP_ATOMIC);
+	nskb = nf_reject_skb_v6_unreach(net, oldskb, dev, hook, code);
 	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 = skb_put_zero(nskb, sizeof(struct icmp6hdr));
-	icmp6h->icmp6_type = ICMPV6_DEST_UNREACH;
-	icmp6h->icmp6_code = code;
-
-	skb_put_data(nskb, 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_forward(br_port_get_rcu(dev), nskb, false, true);
diff --git a/net/ipv4/netfilter/nf_reject_ipv4.c b/net/ipv4/netfilter/nf_reject_ipv4.c
index 9dcfa4e461b6..8ca99342879c 100644
--- a/net/ipv4/netfilter/nf_reject_ipv4.c
+++ b/net/ipv4/netfilter/nf_reject_ipv4.c
@@ -12,6 +12,128 @@
 #include <linux/netfilter_ipv4.h>
 #include <linux/netfilter_bridge.h>
 
+static int nf_reject_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;
+}
+
+struct sk_buff *nf_reject_skb_v4_tcp_reset(struct net *net,
+					   struct sk_buff *oldskb,
+					   const struct net_device *dev,
+					   int hook)
+{
+	const struct tcphdr *oth;
+	struct sk_buff *nskb;
+	struct iphdr *niph;
+	struct tcphdr _oth;
+
+	if (!nf_reject_iphdr_validate(oldskb))
+		return NULL;
+
+	oth = nf_reject_ip_tcphdr_get(oldskb, &_oth, hook);
+	if (!oth)
+		return NULL;
+
+	nskb = alloc_skb(sizeof(struct iphdr) + sizeof(struct tcphdr) +
+			 LL_MAX_HEADER, GFP_ATOMIC);
+	if (!nskb)
+		return NULL;
+
+	nskb->dev = (struct net_device *)dev;
+
+	skb_reserve(nskb, LL_MAX_HEADER);
+	niph = nf_reject_iphdr_put(nskb, oldskb, IPPROTO_TCP,
+				   net->ipv4.sysctl_ip_default_ttl);
+	nf_reject_ip_tcphdr_put(nskb, oldskb, oth);
+	niph->tot_len = htons(nskb->len);
+	ip_send_check(niph);
+
+	return nskb;
+}
+EXPORT_SYMBOL_GPL(nf_reject_skb_v4_tcp_reset);
+
+struct sk_buff *nf_reject_skb_v4_unreach(struct net *net,
+					 struct sk_buff *oldskb,
+					 const struct net_device *dev,
+					 int hook, u8 code)
+{
+	struct sk_buff *nskb;
+	struct iphdr *niph;
+	struct icmphdr *icmph;
+	unsigned int len;
+	__wsum csum;
+	u8 proto;
+
+	if (!nf_reject_iphdr_validate(oldskb))
+		return NULL;
+
+	/* IP header checks: fragment. */
+	if (ip_hdr(oldskb)->frag_off & htons(IP_OFFSET))
+		return NULL;
+
+	/* 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 NULL;
+
+	if (pskb_trim_rcsum(oldskb, ntohs(ip_hdr(oldskb)->tot_len)))
+		return NULL;
+
+	proto = ip_hdr(oldskb)->protocol;
+
+	if (!skb_csum_unnecessary(oldskb) &&
+	    nf_reject_verify_csum(proto) &&
+	    nf_ip_checksum(oldskb, hook, ip_hdrlen(oldskb), proto))
+		return NULL;
+
+	nskb = alloc_skb(sizeof(struct iphdr) + sizeof(struct icmphdr) +
+			 LL_MAX_HEADER + len, GFP_ATOMIC);
+	if (!nskb)
+		return NULL;
+
+	nskb->dev = (struct net_device *)dev;
+
+	skb_reserve(nskb, LL_MAX_HEADER);
+	niph = nf_reject_iphdr_put(nskb, oldskb, IPPROTO_ICMP,
+				   net->ipv4.sysctl_ip_default_ttl);
+
+	skb_reset_transport_header(nskb);
+	icmph = skb_put_zero(nskb, sizeof(struct icmphdr));
+	icmph->type     = ICMP_DEST_UNREACH;
+	icmph->code	= code;
+
+	skb_put_data(nskb, 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);
+
+	return nskb;
+}
+EXPORT_SYMBOL_GPL(nf_reject_skb_v4_unreach);
+
 const struct tcphdr *nf_reject_ip_tcphdr_get(struct sk_buff *oldskb,
 					     struct tcphdr *_oth, int hook)
 {
diff --git a/net/ipv6/netfilter/nf_reject_ipv6.c b/net/ipv6/netfilter/nf_reject_ipv6.c
index 4aef6baaa55e..8dcceda6c32a 100644
--- a/net/ipv6/netfilter/nf_reject_ipv6.c
+++ b/net/ipv6/netfilter/nf_reject_ipv6.c
@@ -12,6 +12,140 @@
 #include <linux/netfilter_ipv6.h>
 #include <linux/netfilter_bridge.h>
 
+static bool nf_reject_v6_csum_ok(struct sk_buff *skb, int hook)
+{
+	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
+	int thoff;
+	__be16 fo;
+	u8 proto = ip6h->nexthdr;
+
+	if (skb_csum_unnecessary(skb))
+		return true;
+
+	if (ip6h->payload_len &&
+	    pskb_trim_rcsum(skb, ntohs(ip6h->payload_len) + sizeof(*ip6h)))
+		return false;
+
+	ip6h = ipv6_hdr(skb);
+	thoff = ipv6_skip_exthdr(skb, ((u8*)(ip6h+1) - skb->data), &proto, &fo);
+	if (thoff < 0 || thoff >= skb->len || (fo & htons(~0x7)) != 0)
+		return false;
+
+	if (!nf_reject_verify_csum(proto))
+		return true;
+
+	return nf_ip6_checksum(skb, hook, thoff, proto) == 0;
+}
+
+static int nf_reject_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;
+}
+
+struct sk_buff *nf_reject_skb_v6_tcp_reset(struct net *net,
+					   struct sk_buff *oldskb,
+					   const struct net_device *dev,
+					   int hook)
+{
+	struct sk_buff *nskb;
+	const struct tcphdr *oth;
+	struct tcphdr _oth;
+	unsigned int otcplen;
+	struct ipv6hdr *nip6h;
+
+	if (!nf_reject_ip6hdr_validate(oldskb))
+		return NULL;
+
+	oth = nf_reject_ip6_tcphdr_get(oldskb, &_oth, &otcplen, hook);
+	if (!oth)
+		return NULL;
+
+	nskb = alloc_skb(sizeof(struct ipv6hdr) + sizeof(struct tcphdr) +
+			 LL_MAX_HEADER, GFP_ATOMIC);
+	if (!nskb)
+		return NULL;
+
+	nskb->dev = (struct net_device *)dev;
+
+	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));
+
+	return nskb;
+}
+EXPORT_SYMBOL_GPL(nf_reject_skb_v6_tcp_reset);
+
+struct sk_buff *nf_reject_skb_v6_unreach(struct net *net,
+					 struct sk_buff *oldskb,
+					 const struct net_device *dev,
+					 int hook, u8 code)
+{
+	struct sk_buff *nskb;
+	struct ipv6hdr *nip6h;
+	struct icmp6hdr *icmp6h;
+	unsigned int len;
+
+	if (!nf_reject_ip6hdr_validate(oldskb))
+		return NULL;
+
+	/* 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 NULL;
+
+	if (!nf_reject_v6_csum_ok(oldskb, hook))
+		return NULL;
+
+	nskb = alloc_skb(sizeof(struct ipv6hdr) + sizeof(struct icmp6hdr) +
+			 LL_MAX_HEADER + len, GFP_ATOMIC);
+	if (!nskb)
+		return NULL;
+
+	nskb->dev = (struct net_device *)dev;
+
+	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 = skb_put_zero(nskb, sizeof(struct icmp6hdr));
+	icmp6h->icmp6_type = ICMPV6_DEST_UNREACH;
+	icmp6h->icmp6_code = code;
+
+	skb_put_data(nskb, 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));
+
+	return nskb;
+}
+EXPORT_SYMBOL_GPL(nf_reject_skb_v6_unreach);
+
 const struct tcphdr *nf_reject_ip6_tcphdr_get(struct sk_buff *oldskb,
 					      struct tcphdr *otcph,
 					      unsigned int *otcplen, int hook)