1 files changed, 12 insertions, 247 deletions

diff --git a/net/bridge/netfilter/nft_reject_bridge.c b/net/bridge/netfilter/nft_reject_bridge.c
index b325b569e761..71b54fed7263 100644
--- a/net/bridge/netfilter/nft_reject_bridge.c
+++ b/net/bridge/netfilter/nft_reject_bridge.c
@@ -31,30 +31,12 @@ static void nft_reject_br_push_etherhdr(struct sk_buff *oldskb,
 	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_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;
+	if (skb_vlan_tag_present(oldskb)) {
+		u16 vid = skb_vlan_tag_get(oldskb);
 
-	return 1;
+		__vlan_hwaccel_put_tag(nskb, oldskb->vlan_proto, vid);
+	}
 }
 
 /* We cannot use oldskb->dev, it can be either bridge device (NF_BRIDGE INPUT)
@@ -66,29 +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, NULL, 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);
@@ -100,139 +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, NULL, 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, NULL, 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,
@@ -240,49 +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, NULL, 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);
@@ -358,70 +177,15 @@ static int nft_reject_bridge_validate(const struct nft_ctx *ctx,
 						    (1 << NF_BR_LOCAL_IN));
 }
 
-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;
-
-	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;
-	default:
-		break;
-	}
-
-	return 0;
-
-nla_put_failure:
-	return -1;
-}
-
 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,
+	.init		= nft_reject_init,
+	.dump		= nft_reject_dump,
 	.validate	= nft_reject_bridge_validate,
+	.reduce		= NFT_REDUCE_READONLY,
 };
 
 static struct nft_expr_type nft_reject_bridge_type __read_mostly = {
@@ -449,3 +213,4 @@ 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");
+MODULE_DESCRIPTION("Reject packets from bridge via nftables");