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

Pablo Neira Ayuso says:

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

The following patchset contains Netfilter updates for your net-next
tree. Basically, updates to the conntrack core, enhancements for
nf_tables, conversion of netfilter hooks from linked list to array to
improve memory locality and asorted improvements for the Netfilter
codebase. More specifically, they are:

1) Add expection to hashes after timer initialization to prevent
   access from another CPU that walks on the hashes and calls
   del_timer(), from Florian Westphal.

2) Don't update nf_tables chain counters from hot path, this is only
   used by the x_tables compatibility layer.

3) Get rid of nested rcu_read_lock() calls from netfilter hook path.
   Hooks are always guaranteed to run from rcu read side, so remove
   nested rcu_read_lock() where possible. Patch from Taehee Yoo.

4) nf_tables new ruleset generation notifications include PID and name
   of the process that has updated the ruleset, from Phil Sutter.

5) Use skb_header_pointer() from nft_fib, so we can reuse this code from
   the nf_family netdev family. Patch from Pablo M. Bermudo.

6) Add support for nft_fib in nf_tables netdev family, also from Pablo.

7) Use deferrable workqueue for conntrack garbage collection, to reduce
   power consumption, from Patch from Subash Abhinov Kasiviswanathan.

8) Add nf_ct_expect_iterate_net() helper and use it. From Florian
   Westphal.

9) Call nf_ct_unconfirmed_destroy only from cttimeout, from Florian.

10) Drop references on conntrack removal path when skbuffs has escaped via
    nfqueue, from Florian.

11) Don't queue packets to nfqueue with dying conntrack, from Florian.

12) Constify nf_hook_ops structure, from Florian.

13) Remove neededlessly branch in nf_tables trace code, from Phil Sutter.

14) Add nla_strdup(), from Phil Sutter.

15) Rise nf_tables objects name size up to 255 chars, people want to use
    DNS names, so increase this according to what RFC 1035 specifies.
    Patch series from Phil Sutter.

16) Kill nf_conntrack_default_on, it's broken. Default on conntrack hook
    registration on demand, suggested by Eric Dumazet, patch from Florian.

17) Remove unused variables in compat_copy_entry_from_user both in
    ip_tables and arp_tables code. Patch from Taehee Yoo.

18) Constify struct nf_conntrack_l4proto, from Julia Lawall.

19) Constify nf_loginfo structure, also from Julia.

20) Use a single rb root in connlimit, from Taehee Yoo.

21) Remove unused netfilter_queue_init() prototype, from Taehee Yoo.

22) Use audit_log() instead of open-coding it, from Geliang Tang.

23) Allow to mangle tcp options via nft_exthdr, from Florian.

24) Allow to fetch TCP MSS from nft_rt, from Florian. This includes
    a fix for a miscalculation of the minimal length.

25) Simplify branch logic in h323 helper, from Nick Desaulniers.

26) Calculate netlink attribute size for conntrack tuple at compile
    time, from Florian.

27) Remove protocol name field from nf_conntrack_{l3,l4}proto structure.
    From Florian.

28) Remove holes in nf_conntrack_l4proto structure, so it becomes
    smaller. From Florian.

29) Get rid of print_tuple() indirection for /proc conntrack listing.
    Place all the code in net/netfilter/nf_conntrack_standalone.c.
    Patch from Florian.

30) Do not built in print_conntrack() if CONFIG_NF_CONNTRACK_PROCFS is
    off. From Florian.

31) Constify most nf_conntrack_{l3,l4}proto helper functions, from
    Florian.

32) Fix broken indentation in ebtables extensions, from Colin Ian King.

33) Fix several harmless sparse warning, from Florian.

34) Convert netfilter hook infrastructure to use array for better memory
    locality, joint work done by Florian and Aaron Conole. Moreover, add
    some instrumentation to debug this.

35) Batch nf_unregister_net_hooks() calls, to call synchronize_net once
    per batch, from Florian.

36) Get rid of noisy logging in ICMPv6 conntrack helper, from Florian.

37) Get rid of obsolete NFDEBUG() instrumentation, from Varsha Rao.

38) Remove unused code in the generic protocol tracker, from Davide
    Caratti.

I think I will have material for a second Netfilter batch in my queue if
time allow to make it fit in this merge window.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 70 insertions, 3 deletions

diff --git a/net/netfilter/nft_rt.c b/net/netfilter/nft_rt.c
index c7383d8f88d0..a6b7d05aeacf 100644
--- a/net/netfilter/nft_rt.c
+++ b/net/netfilter/nft_rt.c
@@ -23,6 +23,43 @@ struct nft_rt {
 	enum nft_registers	dreg:8;
 };
 
+static u16 get_tcpmss(const struct nft_pktinfo *pkt, const struct dst_entry *skbdst)
+{
+	u32 minlen = sizeof(struct ipv6hdr), mtu = dst_mtu(skbdst);
+	const struct sk_buff *skb = pkt->skb;
+	const struct nf_afinfo *ai;
+	struct flowi fl;
+
+	memset(&fl, 0, sizeof(fl));
+
+	switch (nft_pf(pkt)) {
+	case NFPROTO_IPV4:
+		fl.u.ip4.daddr = ip_hdr(skb)->saddr;
+		minlen = sizeof(struct iphdr) + sizeof(struct tcphdr);
+		break;
+	case NFPROTO_IPV6:
+		fl.u.ip6.daddr = ipv6_hdr(skb)->saddr;
+		minlen = sizeof(struct ipv6hdr) + sizeof(struct tcphdr);
+		break;
+	}
+
+	ai = nf_get_afinfo(nft_pf(pkt));
+	if (ai) {
+		struct dst_entry *dst = NULL;
+
+		ai->route(nft_net(pkt), &dst, &fl, false);
+		if (dst) {
+			mtu = min(mtu, dst_mtu(dst));
+			dst_release(dst);
+		}
+	}
+
+	if (mtu <= minlen || mtu > 0xffff)
+		return TCP_MSS_DEFAULT;
+
+	return mtu - minlen;
+}
+
 static void nft_rt_get_eval(const struct nft_expr *expr,
 			    struct nft_regs *regs,
 			    const struct nft_pktinfo *pkt)
@@ -46,8 +83,8 @@ static void nft_rt_get_eval(const struct nft_expr *expr,
 		if (nft_pf(pkt) != NFPROTO_IPV4)
 			goto err;
 
-		*dest = rt_nexthop((const struct rtable *)dst,
-				   ip_hdr(skb)->daddr);
+		*dest = (__force u32)rt_nexthop((const struct rtable *)dst,
+						ip_hdr(skb)->daddr);
 		break;
 	case NFT_RT_NEXTHOP6:
 		if (nft_pf(pkt) != NFPROTO_IPV6)
@@ -57,6 +94,9 @@ static void nft_rt_get_eval(const struct nft_expr *expr,
 					 &ipv6_hdr(skb)->daddr),
 		       sizeof(struct in6_addr));
 		break;
+	case NFT_RT_TCPMSS:
+		nft_reg_store16(dest, get_tcpmss(pkt, dst));
+		break;
 	default:
 		WARN_ON(1);
 		goto err;
@@ -67,7 +107,7 @@ err:
 	regs->verdict.code = NFT_BREAK;
 }
 
-const struct nla_policy nft_rt_policy[NFTA_RT_MAX + 1] = {
+static const struct nla_policy nft_rt_policy[NFTA_RT_MAX + 1] = {
 	[NFTA_RT_DREG]		= { .type = NLA_U32 },
 	[NFTA_RT_KEY]		= { .type = NLA_U32 },
 };
@@ -94,6 +134,9 @@ static int nft_rt_get_init(const struct nft_ctx *ctx,
 	case NFT_RT_NEXTHOP6:
 		len = sizeof(struct in6_addr);
 		break;
+	case NFT_RT_TCPMSS:
+		len = sizeof(u16);
+		break;
 	default:
 		return -EOPNOTSUPP;
 	}
@@ -118,6 +161,29 @@ nla_put_failure:
 	return -1;
 }
 
+static int nft_rt_validate(const struct nft_ctx *ctx, const struct nft_expr *expr,
+			   const struct nft_data **data)
+{
+	const struct nft_rt *priv = nft_expr_priv(expr);
+	unsigned int hooks;
+
+	switch (priv->key) {
+	case NFT_RT_NEXTHOP4:
+	case NFT_RT_NEXTHOP6:
+	case NFT_RT_CLASSID:
+		return 0;
+	case NFT_RT_TCPMSS:
+		hooks = (1 << NF_INET_FORWARD) |
+			(1 << NF_INET_LOCAL_OUT) |
+			(1 << NF_INET_POST_ROUTING);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return nft_chain_validate_hooks(ctx->chain, hooks);
+}
+
 static struct nft_expr_type nft_rt_type;
 static const struct nft_expr_ops nft_rt_get_ops = {
 	.type		= &nft_rt_type,
@@ -125,6 +191,7 @@ static const struct nft_expr_ops nft_rt_get_ops = {
 	.eval		= nft_rt_get_eval,
 	.init		= nft_rt_get_init,
 	.dump		= nft_rt_get_dump,
+	.validate	= nft_rt_validate,
 };
 
 static struct nft_expr_type nft_rt_type __read_mostly = {