[NETFILTER] x_tables: Abstraction layer for {ip,ip6,arp}_tables

This monster-patch tries to do the best job for unifying the data
structures and backend interfaces for the three evil clones ip_tables,
ip6_tables and arp_tables.  In an ideal world we would never have
allowed this kind of copy+paste programming... but well, our world
isn't (yet?) ideal.

o introduce a new x_tables module
o {ip,arp,ip6}_tables depend on this x_tables module
o registration functions for tables, matches and targets are only
  wrappers around x_tables provided functions
o all matches/targets that are used from ip_tables and ip6_tables
  are now implemented as xt_FOOBAR.c files and provide module aliases
  to ipt_FOOBAR and ip6t_FOOBAR
o header files for xt_matches are in include/linux/netfilter/,
  include/linux/netfilter_{ipv4,ipv6} contains compatibility wrappers
  around the xt_FOOBAR.h headers

Based on this patchset we're going to further unify the code,
gradually getting rid of all the layer 3 specific assumptions.

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 0 insertions, 127 deletions

diff --git a/net/ipv4/netfilter/ipt_tcpmss.c b/net/ipv4/netfilter/ipt_tcpmss.c
deleted file mode 100644
index 4dc9b16ab4a..00000000000
--- a/net/ipv4/netfilter/ipt_tcpmss.c
+++ /dev/null
@@ -1,127 +0,0 @@
-/* Kernel module to match TCP MSS values. */
-
-/* Copyright (C) 2000 Marc Boucher <marc@mbsi.ca>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-
-#include <linux/module.h>
-#include <linux/skbuff.h>
-#include <net/tcp.h>
-
-#include <linux/netfilter_ipv4/ipt_tcpmss.h>
-#include <linux/netfilter_ipv4/ip_tables.h>
-
-#define TH_SYN 0x02
-
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
-MODULE_DESCRIPTION("iptables TCP MSS match module");
-
-/* Returns 1 if the mss option is set and matched by the range, 0 otherwise */
-static inline int
-mssoption_match(u_int16_t min, u_int16_t max,
-		const struct sk_buff *skb,
-		int invert,
-		int *hotdrop)
-{
-	struct tcphdr _tcph, *th;
-	/* tcp.doff is only 4 bits, ie. max 15 * 4 bytes */
-	u8 _opt[15 * 4 - sizeof(_tcph)], *op;
-	unsigned int i, optlen;
-
-	/* If we don't have the whole header, drop packet. */
-	th = skb_header_pointer(skb, skb->nh.iph->ihl * 4,
-				sizeof(_tcph), &_tcph);
-	if (th == NULL)
-		goto dropit;
-
-	/* Malformed. */
-	if (th->doff*4 < sizeof(*th))
-		goto dropit;
-
-	optlen = th->doff*4 - sizeof(*th);
-	if (!optlen)
-		goto out;
-
-	/* Truncated options. */
-	op = skb_header_pointer(skb, skb->nh.iph->ihl * 4 + sizeof(*th),
-				optlen, _opt);
-	if (op == NULL)
-		goto dropit;
-
-	for (i = 0; i < optlen; ) {
-		if (op[i] == TCPOPT_MSS
-		    && (optlen - i) >= TCPOLEN_MSS
-		    && op[i+1] == TCPOLEN_MSS) {
-			u_int16_t mssval;
-
-			mssval = (op[i+2] << 8) | op[i+3];
-			
-			return (mssval >= min && mssval <= max) ^ invert;
-		}
-		if (op[i] < 2) i++;
-		else i += op[i+1]?:1;
-	}
-out:
-	return invert;
-
- dropit:
-	*hotdrop = 1;
-	return 0;
-}
-
-static int
-match(const struct sk_buff *skb,
-      const struct net_device *in,
-      const struct net_device *out,
-      const void *matchinfo,
-      int offset,
-      int *hotdrop)
-{
-	const struct ipt_tcpmss_match_info *info = matchinfo;
-
-	return mssoption_match(info->mss_min, info->mss_max, skb,
-			       info->invert, hotdrop);
-}
-
-static int
-checkentry(const char *tablename,
-           const struct ipt_ip *ip,
-           void *matchinfo,
-           unsigned int matchsize,
-           unsigned int hook_mask)
-{
-	if (matchsize != IPT_ALIGN(sizeof(struct ipt_tcpmss_match_info)))
-		return 0;
-
-	/* Must specify -p tcp */
-	if (ip->proto != IPPROTO_TCP || (ip->invflags & IPT_INV_PROTO)) {
-		printk("tcpmss: Only works on TCP packets\n");
-		return 0;
-	}
-
-	return 1;
-}
-
-static struct ipt_match tcpmss_match = {
-	.name		= "tcpmss",
-	.match		= &match,
-	.checkentry	= &checkentry,
-	.me		= THIS_MODULE,
-};
-
-static int __init init(void)
-{
-	return ipt_register_match(&tcpmss_match);
-}
-
-static void __exit fini(void)
-{
-	ipt_unregister_match(&tcpmss_match);
-}
-
-module_init(init);
-module_exit(fini);