Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next

Pablo Neira Ayuso says:

====================
Netfilter updates for net-next

1) Move existing bridge packet reject infra to nf_reject_{ipv4,ipv6}.c
   from Jose M. Guisado.

2) Consolidate nft_reject_inet initialization and dump, also from Jose.

3) Add the netdev reject action, from Jose.

4) Allow to combine the exist flag and the destroy command in ipset,
   from Joszef Kadlecsik.

5) Expose bucket size parameter for hashtables, also from Jozsef.

6) Expose the init value for reproducible ipset listings, from Jozsef.

7) Use __printf attribute in nft_request_module, from Andrew Lunn.

8) Allow to use reject from the inet ingress chain.

* git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next:
  netfilter: nft_reject_inet: allow to use reject from inet ingress
  netfilter: nftables: Add __printf() attribute
  netfilter: ipset: Expose the initval hash parameter to userspace
  netfilter: ipset: Add bucketsize parameter to all hash types
  netfilter: ipset: Support the -exist flag with the destroy command
  netfilter: nft_reject: add reject verdict support for netdev
  netfilter: nft_reject: unify reject init and dump into nft_reject
  netfilter: nf_reject: add reject skbuff creation helpers
====================

Link: https://lore.kernel.org/r/20201104141149.30082-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

2 files changed, 7 insertions, 250 deletions

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..eba0efe64d05 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);
@@ -364,69 +177,13 @@ 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,
 };