[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, 95 insertions, 747 deletions

diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 877bc96d333..2371b2062c2 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -2,7 +2,7 @@
  * Packet matching code.
  *
  * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
- * Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org>
+ * Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
  *
  * 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
@@ -11,6 +11,8 @@
  * 19 Jan 2002 Harald Welte <laforge@gnumonks.org>
  *      - increase module usage count as soon as we have rules inside
  *        a table
+ * 08 Oct 2005 Harald Welte <lafore@netfilter.org>
+ *      - Generalize into "x_tables" layer and "{ip,ip6,arp}_tables"
  */
 #include <linux/config.h>
 #include <linux/cache.h>
@@ -20,8 +22,6 @@
 #include <linux/vmalloc.h>
 #include <linux/netdevice.h>
 #include <linux/module.h>
-#include <linux/tcp.h>
-#include <linux/udp.h>
 #include <linux/icmp.h>
 #include <net/ip.h>
 #include <asm/uaccess.h>
@@ -30,6 +30,7 @@
 #include <linux/err.h>
 #include <linux/cpumask.h>
 
+#include <linux/netfilter/x_tables.h>
 #include <linux/netfilter_ipv4/ip_tables.h>
 
 MODULE_LICENSE("GPL");
@@ -62,14 +63,6 @@ do {								\
 #else
 #define IP_NF_ASSERT(x)
 #endif
-#define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
-
-static DECLARE_MUTEX(ipt_mutex);
-
-/* Must have mutex */
-#define ASSERT_READ_LOCK(x) IP_NF_ASSERT(down_trylock(&ipt_mutex) != 0)
-#define ASSERT_WRITE_LOCK(x) IP_NF_ASSERT(down_trylock(&ipt_mutex) != 0)
-#include <linux/netfilter_ipv4/listhelp.h>
 
 #if 0
 /* All the better to debug you with... */
@@ -86,36 +79,6 @@ static DECLARE_MUTEX(ipt_mutex);
 
    Hence the start of any table is given by get_table() below.  */
 
-/* The table itself */
-struct ipt_table_info
-{
-        /* Size per table */
-        unsigned int size;
-        /* Number of entries: FIXME. --RR */
-        unsigned int number;
-        /* Initial number of entries. Needed for module usage count */
-        unsigned int initial_entries;
-
-        /* Entry points and underflows */
-        unsigned int hook_entry[NF_IP_NUMHOOKS];
-        unsigned int underflow[NF_IP_NUMHOOKS];
-
-        /* ipt_entry tables: one per CPU */
-        void *entries[NR_CPUS];
-};
-
-static LIST_HEAD(ipt_target);
-static LIST_HEAD(ipt_match);
-static LIST_HEAD(ipt_tables);
-#define SET_COUNTER(c,b,p) do { (c).bcnt = (b); (c).pcnt = (p); } while(0)
-#define ADD_COUNTER(c,b,p) do { (c).bcnt += (b); (c).pcnt += (p); } while(0)
-
-#if 0
-#define down(x) do { printk("DOWN:%u:" #x "\n", __LINE__); down(x); } while(0)
-#define down_interruptible(x) ({ int __r; printk("DOWNi:%u:" #x "\n", __LINE__); __r = down_interruptible(x); if (__r != 0) printk("ABORT-DOWNi:%u\n", __LINE__); __r; })
-#define up(x) do { printk("UP:%u:" #x "\n", __LINE__); up(x); } while(0)
-#endif
-
 /* Returns whether matches rule or not. */
 static inline int
 ip_packet_match(const struct iphdr *ip,
@@ -234,7 +197,8 @@ int do_match(struct ipt_entry_match *m,
              int *hotdrop)
 {
         /* Stop iteration if it doesn't match */
-        if (!m->u.kernel.match->match(skb, in, out, m->data, offset, hotdrop))
+        if (!m->u.kernel.match->match(skb, in, out, m->data, offset, 
+            skb->nh.iph->ihl*4, hotdrop))
                 return 1;
         else
                 return 0;
@@ -265,6 +229,7 @@ ipt_do_table(struct sk_buff **pskb,
         const char *indev, *outdev;
         void *table_base;
         struct ipt_entry *e, *back;
+        struct xt_table_info *private = table->private;
 
         /* Initialization */
         ip = (*pskb)->nh.iph;
@@ -281,24 +246,11 @@ ipt_do_table(struct sk_buff **pskb,
 
         read_lock_bh(&table->lock);
         IP_NF_ASSERT(table->valid_hooks & (1 << hook));
-        table_base = (void *)table->private->entries[smp_processor_id()];
-        e = get_entry(table_base, table->private->hook_entry[hook]);
-
-#ifdef CONFIG_NETFILTER_DEBUG
-        /* Check noone else using our table */
-        if (((struct ipt_entry *)table_base)->comefrom != 0xdead57ac
-            && ((struct ipt_entry *)table_base)->comefrom != 0xeeeeeeec) {
-                printk("ASSERT: CPU #%u, %s comefrom(%p) = %X\n",
-                       smp_processor_id(),
-                       table->name,
-                       &((struct ipt_entry *)table_base)->comefrom,
-                       ((struct ipt_entry *)table_base)->comefrom);
-        }
-        ((struct ipt_entry *)table_base)->comefrom = 0x57acc001;
-#endif
+        table_base = (void *)private->entries[smp_processor_id()];
+        e = get_entry(table_base, private->hook_entry[hook]);
 
         /* For return from builtin chain */
-        back = get_entry(table_base, table->private->underflow[hook]);
+        back = get_entry(table_base, private->underflow[hook]);
 
         do {
                 IP_NF_ASSERT(e);
@@ -384,9 +336,6 @@ ipt_do_table(struct sk_buff **pskb,
                 }
         } while (!hotdrop);
 
-#ifdef CONFIG_NETFILTER_DEBUG
-        ((struct ipt_entry *)table_base)->comefrom = 0xdead57ac;
-#endif
         read_unlock_bh(&table->lock);
 
 #ifdef DEBUG_ALLOW_ALL
@@ -398,145 +347,6 @@ ipt_do_table(struct sk_buff **pskb,
 #endif
 }
 
-/*
- * These are weird, but module loading must not be done with mutex
- * held (since they will register), and we have to have a single
- * function to use try_then_request_module().
- */
-
-/* Find table by name, grabs mutex & ref.  Returns ERR_PTR() on error. */
-static inline struct ipt_table *find_table_lock(const char *name)
-{
-        struct ipt_table *t;
-
-        if (down_interruptible(&ipt_mutex) != 0)
-                return ERR_PTR(-EINTR);
-
-        list_for_each_entry(t, &ipt_tables, list)
-                if (strcmp(t->name, name) == 0 && try_module_get(t->me))
-                        return t;
-        up(&ipt_mutex);
-        return NULL;
-}
-
-/* Find match, grabs ref.  Returns ERR_PTR() on error. */
-static inline struct ipt_match *find_match(const char *name, u8 revision)
-{
-        struct ipt_match *m;
-        int err = 0;
-
-        if (down_interruptible(&ipt_mutex) != 0)
-                return ERR_PTR(-EINTR);
-
-        list_for_each_entry(m, &ipt_match, list) {
-                if (strcmp(m->name, name) == 0) {
-                        if (m->revision == revision) {
-                                if (try_module_get(m->me)) {
-                                        up(&ipt_mutex);
-                                        return m;
-                                }
-                        } else
-                                err = -EPROTOTYPE; /* Found something. */
-                }
-        }
-        up(&ipt_mutex);
-        return ERR_PTR(err);
-}
-
-/* Find target, grabs ref.  Returns ERR_PTR() on error. */
-static inline struct ipt_target *find_target(const char *name, u8 revision)
-{
-        struct ipt_target *t;
-        int err = 0;
-
-        if (down_interruptible(&ipt_mutex) != 0)
-                return ERR_PTR(-EINTR);
-
-        list_for_each_entry(t, &ipt_target, list) {
-                if (strcmp(t->name, name) == 0) {
-                        if (t->revision == revision) {
-                                if (try_module_get(t->me)) {
-                                        up(&ipt_mutex);
-                                        return t;
-                                }
-                        } else
-                                err = -EPROTOTYPE; /* Found something. */
-                }
-        }
-        up(&ipt_mutex);
-        return ERR_PTR(err);
-}
-
-struct ipt_target *ipt_find_target(const char *name, u8 revision)
-{
-        struct ipt_target *target;
-
-        target = try_then_request_module(find_target(name, revision),
-                                         "ipt_%s", name);
-        if (IS_ERR(target) || !target)
-                return NULL;
-        return target;
-}
-
-static int match_revfn(const char *name, u8 revision, int *bestp)
-{
-        struct ipt_match *m;
-        int have_rev = 0;
-
-        list_for_each_entry(m, &ipt_match, list) {
-                if (strcmp(m->name, name) == 0) {
-                        if (m->revision > *bestp)
-                                *bestp = m->revision;
-                        if (m->revision == revision)
-                                have_rev = 1;
-                }
-        }
-        return have_rev;
-}
-
-static int target_revfn(const char *name, u8 revision, int *bestp)
-{
-        struct ipt_target *t;
-        int have_rev = 0;
-
-        list_for_each_entry(t, &ipt_target, list) {
-                if (strcmp(t->name, name) == 0) {
-                        if (t->revision > *bestp)
-                                *bestp = t->revision;
-                        if (t->revision == revision)
-                                have_rev = 1;
-                }
-        }
-        return have_rev;
-}
-
-/* Returns true or false (if no such extension at all) */
-static inline int find_revision(const char *name, u8 revision,
-                                int (*revfn)(const char *, u8, int *),
-                                int *err)
-{
-        int have_rev, best = -1;
-
-        if (down_interruptible(&ipt_mutex) != 0) {
-                *err = -EINTR;
-                return 1;
-        }
-        have_rev = revfn(name, revision, &best);
-        up(&ipt_mutex);
-
-        /* Nothing at all?  Return 0 to try loading module. */
-        if (best == -1) {
-                *err = -ENOENT;
-                return 0;
-        }
-
-        *err = best;
-        if (!have_rev)
-                *err = -EPROTONOSUPPORT;
-        return 1;
-}
-
-
 /* All zeroes == unconditional rule. */
 static inline int
 unconditional(const struct ipt_ip *ip)
@@ -553,7 +363,7 @@ unconditional(const struct ipt_ip *ip)
 /* Figures out from what hook each rule can be called: returns 0 if
    there are loops.  Puts hook bitmask in comefrom. */
 static int
-mark_source_chains(struct ipt_table_info *newinfo,
+mark_source_chains(struct xt_table_info *newinfo,
                    unsigned int valid_hooks, void *entry0)
 {
         unsigned int hook;
@@ -699,7 +509,7 @@ check_match(struct ipt_entry_match *m,
 {
         struct ipt_match *match;
 
-        match = try_then_request_module(find_match(m->u.user.name,
+        match = try_then_request_module(xt_find_match(AF_INET, m->u.user.name,
                                                    m->u.user.revision),
                                         "ipt_%s", m->u.user.name);
         if (IS_ERR(match) || !match) {
@@ -744,7 +554,8 @@ check_entry(struct ipt_entry *e, const char *name, unsigned int size,
                 goto cleanup_matches;
 
         t = ipt_get_target(e);
-        target = try_then_request_module(find_target(t->u.user.name,
+        target = try_then_request_module(xt_find_target(AF_INET,
+                                                     t->u.user.name,
                                                      t->u.user.revision),
                                          "ipt_%s", t->u.user.name);
         if (IS_ERR(target) || !target) {
@@ -781,7 +592,7 @@ check_entry(struct ipt_entry *e, const char *name, unsigned int size,
 
 static inline int
 check_entry_size_and_hooks(struct ipt_entry *e,
-                           struct ipt_table_info *newinfo,
+                           struct xt_table_info *newinfo,
                            unsigned char *base,
                            unsigned char *limit,
                            const unsigned int *hook_entries,
@@ -815,7 +626,7 @@ check_entry_size_and_hooks(struct ipt_entry *e,
            < 0 (not IPT_RETURN). --RR */
 
         /* Clear counters and comefrom */
-        e->counters = ((struct ipt_counters) { 0, 0 });
+        e->counters = ((struct xt_counters) { 0, 0 });
         e->comefrom = 0;
 
         (*i)++;
@@ -845,7 +656,7 @@ cleanup_entry(struct ipt_entry *e, unsigned int *i)
 static int
 translate_table(const char *name,
                 unsigned int valid_hooks,
-                struct ipt_table_info *newinfo,
+                struct xt_table_info *newinfo,
                 void *entry0,
                 unsigned int size,
                 unsigned int number,
@@ -922,48 +733,10 @@ translate_table(const char *name,
         return ret;
 }
 
-static struct ipt_table_info *
-replace_table(struct ipt_table *table,
-              unsigned int num_counters,
-              struct ipt_table_info *newinfo,
-              int *error)
-{
-        struct ipt_table_info *oldinfo;
-
-#ifdef CONFIG_NETFILTER_DEBUG
-        {
-                int cpu;
-
-                for_each_cpu(cpu) {
-                        struct ipt_entry *table_base = newinfo->entries[cpu];
-                        if (table_base)
-                                table_base->comefrom = 0xdead57ac;
-                }
-        }
-#endif
-
-        /* Do the substitution. */
-        write_lock_bh(&table->lock);
-        /* Check inside lock: is the old number correct? */
-        if (num_counters != table->private->number) {
-                duprintf("num_counters != table->private->number (%u/%u)\n",
-                         num_counters, table->private->number);
-                write_unlock_bh(&table->lock);
-                *error = -EAGAIN;
-                return NULL;
-        }
-        oldinfo = table->private;
-        table->private = newinfo;
-        newinfo->initial_entries = oldinfo->initial_entries;
-        write_unlock_bh(&table->lock);
-
-        return oldinfo;
-}
-
 /* Gets counters. */
 static inline int
 add_entry_to_counter(const struct ipt_entry *e,
-                     struct ipt_counters total[],
+                     struct xt_counters total[],
                      unsigned int *i)
 {
         ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
@@ -984,8 +757,8 @@ set_entry_to_counter(const struct ipt_entry *e,
 }
 
 static void
-get_counters(const struct ipt_table_info *t,
-             struct ipt_counters counters[])
+get_counters(const struct xt_table_info *t,
+             struct xt_counters counters[])
 {
         unsigned int cpu;
         unsigned int i;
@@ -1024,14 +797,15 @@ copy_entries_to_user(unsigned int total_size,
 {
         unsigned int off, num, countersize;
         struct ipt_entry *e;
-        struct ipt_counters *counters;
+        struct xt_counters *counters;
+        struct xt_table_info *private = table->private;
         int ret = 0;
         void *loc_cpu_entry;
 
         /* We need atomic snapshot of counters: rest doesn't change
            (other than comefrom, which userspace doesn't care
            about). */
-        countersize = sizeof(struct ipt_counters) * table->private->number;
+        countersize = sizeof(struct xt_counters) * private->number;
         counters = vmalloc_node(countersize, numa_node_id());
 
         if (counters == NULL)
@@ -1039,14 +813,14 @@ copy_entries_to_user(unsigned int total_size,
 
         /* First, sum counters... */
         write_lock_bh(&table->lock);
-        get_counters(table->private, counters);
+        get_counters(private, counters);
         write_unlock_bh(&table->lock);
 
         /* choose the copy that is on our node/cpu, ...
          * This choice is lazy (because current thread is
          * allowed to migrate to another cpu)
          */
-        loc_cpu_entry = table->private->entries[raw_smp_processor_id()];
+        loc_cpu_entry = private->entries[raw_smp_processor_id()];
         /* ... then copy entire thing ... */
         if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
                 ret = -EFAULT;
@@ -1108,74 +882,36 @@ get_entries(const struct ipt_get_entries *entries,
         int ret;
         struct ipt_table *t;
 
-        t = find_table_lock(entries->name);
+        t = xt_find_table_lock(AF_INET, entries->name);
         if (t && !IS_ERR(t)) {
+                struct xt_table_info *private = t->private;
                 duprintf("t->private->number = %u\n",
-                         t->private->number);
-                if (entries->size == t->private->size)
-                        ret = copy_entries_to_user(t->private->size,
+                         private->number);
+                if (entries->size == private->size)
+                        ret = copy_entries_to_user(private->size,
                                                    t, uptr->entrytable);
                 else {
                         duprintf("get_entries: I've got %u not %u!\n",
-                                 t->private->size,
+                                 private->size,
                                  entries->size);
                         ret = -EINVAL;
                 }
                 module_put(t->me);
-                up(&ipt_mutex);
+                xt_table_unlock(t);
         } else
                 ret = t ? PTR_ERR(t) : -ENOENT;
 
         return ret;
 }
 
-static void free_table_info(struct ipt_table_info *info)
-{
-        int cpu;
-        for_each_cpu(cpu) {
-                if (info->size <= PAGE_SIZE)
-                        kfree(info->entries[cpu]);
-                else
-                        vfree(info->entries[cpu]);
-        }
-        kfree(info);
-}
-
-static struct ipt_table_info *alloc_table_info(unsigned int size)
-{
-        struct ipt_table_info *newinfo;
-        int cpu;
-
-        newinfo = kzalloc(sizeof(struct ipt_table_info), GFP_KERNEL);
-        if (!newinfo)
-                return NULL;
-
-        newinfo->size = size;
-
-        for_each_cpu(cpu) {
-                if (size <= PAGE_SIZE)
-                        newinfo->entries[cpu] = kmalloc_node(size,
-                                GFP_KERNEL,
-                                cpu_to_node(cpu));
-                else
-                        newinfo->entries[cpu] = vmalloc_node(size, cpu_to_node(cpu));
-                if (newinfo->entries[cpu] == 0) {
-                        free_table_info(newinfo);
-                        return NULL;
-                }
-        }
-
-        return newinfo;
-}
-
 static int
 do_replace(void __user *user, unsigned int len)
 {
         int ret;
         struct ipt_replace tmp;
         struct ipt_table *t;
-        struct ipt_table_info *newinfo, *oldinfo;
-        struct ipt_counters *counters;
+        struct xt_table_info *newinfo, *oldinfo;
+        struct xt_counters *counters;
         void *loc_cpu_entry, *loc_cpu_old_entry;
 
         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
@@ -1185,11 +921,7 @@ do_replace(void __user *user, unsigned int len)
         if (len != sizeof(tmp) + tmp.size)
                 return -ENOPROTOOPT;
 
-        /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */
-        if ((SMP_ALIGN(tmp.size) >> PAGE_SHIFT) + 2 > num_physpages)
-                return -ENOMEM;
-
-        newinfo = alloc_table_info(tmp.size);
+        newinfo = xt_alloc_table_info(tmp.size);
         if (!newinfo)
                 return -ENOMEM;
 
@@ -1201,7 +933,7 @@ do_replace(void __user *user, unsigned int len)
                 goto free_newinfo;
         }
 
-        counters = vmalloc(tmp.num_counters * sizeof(struct ipt_counters));
+        counters = vmalloc(tmp.num_counters * sizeof(struct xt_counters));
         if (!counters) {
                 ret = -ENOMEM;
                 goto free_newinfo;
@@ -1215,7 +947,7 @@ do_replace(void __user *user, unsigned int len)
 
         duprintf("ip_tables: Translated table\n");
 
-        t = try_then_request_module(find_table_lock(tmp.name),
+        t = try_then_request_module(xt_find_table_lock(AF_INET, tmp.name),
                                     "iptable_%s", tmp.name);
         if (!t || IS_ERR(t)) {
                 ret = t ? PTR_ERR(t) : -ENOENT;
@@ -1230,7 +962,7 @@ do_replace(void __user *user, unsigned int len)
                 goto put_module;
         }
 
-        oldinfo = replace_table(t, tmp.num_counters, newinfo, &ret);
+        oldinfo = xt_replace_table(t, tmp.num_counters, newinfo, &ret);
         if (!oldinfo)
                 goto put_module;
 
@@ -1249,23 +981,23 @@ do_replace(void __user *user, unsigned int len)
         /* Decrease module usage counts and free resource */
         loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
         IPT_ENTRY_ITERATE(loc_cpu_old_entry, oldinfo->size, cleanup_entry,NULL);
-        free_table_info(oldinfo);
+        xt_free_table_info(oldinfo);
         if (copy_to_user(tmp.counters, counters,
-                         sizeof(struct ipt_counters) * tmp.num_counters) != 0)
+                         sizeof(struct xt_counters) * tmp.num_counters) != 0)
                 ret = -EFAULT;
         vfree(counters);
-        up(&ipt_mutex);
+        xt_table_unlock(t);
         return ret;
 
  put_module:
         module_put(t->me);
-        up(&ipt_mutex);
+        xt_table_unlock(t);
  free_newinfo_counters_untrans:
         IPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry,NULL);
  free_newinfo_counters:
         vfree(counters);
  free_newinfo:
-        free_table_info(newinfo);
+        xt_free_table_info(newinfo);
         return ret;
 }
 
@@ -1273,7 +1005,7 @@ do_replace(void __user *user, unsigned int len)
  * and everything is OK. */
 static inline int
 add_counter_to_entry(struct ipt_entry *e,
-                     const struct ipt_counters addme[],
+                     const struct xt_counters addme[],
                      unsigned int *i)
 {
 #if 0
@@ -1295,15 +1027,16 @@ static int
 do_add_counters(void __user *user, unsigned int len)
 {
         unsigned int i;
-        struct ipt_counters_info tmp, *paddc;
+        struct xt_counters_info tmp, *paddc;
         struct ipt_table *t;
+        struct xt_table_info *private;
         int ret = 0;
         void *loc_cpu_entry;
 
         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
                 return -EFAULT;
 
-        if (len != sizeof(tmp) + tmp.num_counters*sizeof(struct ipt_counters))
+        if (len != sizeof(tmp) + tmp.num_counters*sizeof(struct xt_counters))
                 return -EINVAL;
 
         paddc = vmalloc_node(len, numa_node_id());
@@ -1315,29 +1048,30 @@ do_add_counters(void __user *user, unsigned int len)
                 goto free;
         }
 
-        t = find_table_lock(tmp.name);
+        t = xt_find_table_lock(AF_INET, tmp.name);
         if (!t || IS_ERR(t)) {
                 ret = t ? PTR_ERR(t) : -ENOENT;
                 goto free;
         }
 
         write_lock_bh(&t->lock);
-        if (t->private->number != paddc->num_counters) {
+        private = t->private;
+        if (private->number != paddc->num_counters) {
                 ret = -EINVAL;
                 goto unlock_up_free;
         }
 
         i = 0;
         /* Choose the copy that is on our node */
-        loc_cpu_entry = t->private->entries[raw_smp_processor_id()];
+        loc_cpu_entry = private->entries[raw_smp_processor_id()];
         IPT_ENTRY_ITERATE(loc_cpu_entry,
-                          t->private->size,
+                          private->size,
                           add_counter_to_entry,
                           paddc->counters,
                           &i);
  unlock_up_free:
         write_unlock_bh(&t->lock);
-        up(&ipt_mutex);
+        xt_table_unlock(t);
         module_put(t->me);
  free:
         vfree(paddc);
@@ -1396,25 +1130,26 @@ do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
                 }
                 name[IPT_TABLE_MAXNAMELEN-1] = '\0';
 
-                t = try_then_request_module(find_table_lock(name),
+                t = try_then_request_module(xt_find_table_lock(AF_INET, name),
                                             "iptable_%s", name);
                 if (t && !IS_ERR(t)) {
                         struct ipt_getinfo info;
+                        struct xt_table_info *private = t->private;
 
                         info.valid_hooks = t->valid_hooks;
-                        memcpy(info.hook_entry, t->private->hook_entry,
+                        memcpy(info.hook_entry, private->hook_entry,
                                sizeof(info.hook_entry));
-                        memcpy(info.underflow, t->private->underflow,
+                        memcpy(info.underflow, private->underflow,
                                sizeof(info.underflow));
-                        info.num_entries = t->private->number;
-                        info.size = t->private->size;
+                        info.num_entries = private->number;
+                        info.size = private->size;
                         memcpy(info.name, name, sizeof(info.name));
 
                         if (copy_to_user(user, &info, *len) != 0)
                                 ret = -EFAULT;
                         else
                                 ret = 0;
-                        up(&ipt_mutex);
+                        xt_table_unlock(t);
                         module_put(t->me);
                 } else
                         ret = t ? PTR_ERR(t) : -ENOENT;
@@ -1441,7 +1176,7 @@ do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
         case IPT_SO_GET_REVISION_MATCH:
         case IPT_SO_GET_REVISION_TARGET: {
                 struct ipt_get_revision rev;
-                int (*revfn)(const char *, u8, int *);
+                int target;
 
                 if (*len != sizeof(rev)) {
                         ret = -EINVAL;
@@ -1453,12 +1188,13 @@ do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
                 }
 
                 if (cmd == IPT_SO_GET_REVISION_TARGET)
-                        revfn = target_revfn;
+                        target = 1;
                 else
-                        revfn = match_revfn;
+                        target = 0;
 
-                try_then_request_module(find_revision(rev.name, rev.revision,
-                                                      revfn, &ret),
+                try_then_request_module(xt_find_revision(AF_INET, rev.name,
+                                                         rev.revision,
+                                                         target, &ret),
                                         "ipt_%s", rev.name);
                 break;
         }
@@ -1471,60 +1207,15 @@ do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
         return ret;
 }
 
-/* Registration hooks for targets. */
-int
-ipt_register_target(struct ipt_target *target)
+int ipt_register_table(struct xt_table *table, const struct ipt_replace *repl)
 {
         int ret;
-
-        ret = down_interruptible(&ipt_mutex);
-        if (ret != 0)
-                return ret;
-        list_add(&target->list, &ipt_target);
-        up(&ipt_mutex);
-        return ret;
-}
-
-void
-ipt_unregister_target(struct ipt_target *target)
-{
-        down(&ipt_mutex);
-        LIST_DELETE(&ipt_target, target);
-        up(&ipt_mutex);
-}
-
-int
-ipt_register_match(struct ipt_match *match)
-{
-        int ret;
-
-        ret = down_interruptible(&ipt_mutex);
-        if (ret != 0)
-                return ret;
-
-        list_add(&match->list, &ipt_match);
-        up(&ipt_mutex);
-
-        return ret;
-}
-
-void
-ipt_unregister_match(struct ipt_match *match)
-{
-        down(&ipt_mutex);
-        LIST_DELETE(&ipt_match, match);
-        up(&ipt_mutex);
-}
-
-int ipt_register_table(struct ipt_table *table, const struct ipt_replace *repl)
-{
-        int ret;
-        struct ipt_table_info *newinfo;
-        static struct ipt_table_info bootstrap
+        struct xt_table_info *newinfo;
+        static struct xt_table_info bootstrap
                 = { 0, 0, 0, { 0 }, { 0 }, { } };
         void *loc_cpu_entry;
 
-        newinfo = alloc_table_info(repl->size);
+        newinfo = xt_alloc_table_info(repl->size);
         if (!newinfo)
                 return -ENOMEM;
 
@@ -1540,246 +1231,29 @@ int ipt_register_table(struct ipt_table *table, const struct ipt_replace *repl)
                               repl->hook_entry,
                               repl->underflow);
         if (ret != 0) {
-                free_table_info(newinfo);
+                xt_free_table_info(newinfo);
                 return ret;
         }
 
-        ret = down_interruptible(&ipt_mutex);
-        if (ret != 0) {
-                free_table_info(newinfo);
+        if (xt_register_table(table, &bootstrap, newinfo) != 0) {
+                xt_free_table_info(newinfo);
                 return ret;
         }
 
-        /* Don't autoload: we'd eat our tail... */
-        if (list_named_find(&ipt_tables, table->name)) {
-                ret = -EEXIST;
-                goto free_unlock;
-        }
-
-        /* Simplifies replace_table code. */
-        table->private = &bootstrap;
-        if (!replace_table(table, 0, newinfo, &ret))
-                goto free_unlock;
-
-        duprintf("table->private->number = %u\n",
-                 table->private->number);
-        
-        /* save number of initial entries */
-        table->private->initial_entries = table->private->number;
-
-        rwlock_init(&table->lock);
-        list_prepend(&ipt_tables, table);
-
- unlock:
-        up(&ipt_mutex);
-        return ret;
-
- free_unlock:
-        free_table_info(newinfo);
-        goto unlock;
+        return 0;
 }
 
 void ipt_unregister_table(struct ipt_table *table)
 {
+        struct xt_table_info *private;
         void *loc_cpu_entry;
 
-        down(&ipt_mutex);
-        LIST_DELETE(&ipt_tables, table);
-        up(&ipt_mutex);
+        private = xt_unregister_table(table);
 
         /* Decrease module usage counts and free resources */
-        loc_cpu_entry = table->private->entries[raw_smp_processor_id()];
-        IPT_ENTRY_ITERATE(loc_cpu_entry, table->private->size,
-                          cleanup_entry, NULL);
-        free_table_info(table->private);
-}
-
-/* Returns 1 if the port is matched by the range, 0 otherwise */
-static inline int
-port_match(u_int16_t min, u_int16_t max, u_int16_t port, int invert)
-{
-        int ret;
-
-        ret = (port >= min && port <= max) ^ invert;
-        return ret;
-}
-
-static int
-tcp_find_option(u_int8_t option,
-                const struct sk_buff *skb,
-                unsigned int optlen,
-                int invert,
-                int *hotdrop)
-{
-        /* tcp.doff is only 4 bits, ie. max 15 * 4 bytes */
-        u_int8_t _opt[60 - sizeof(struct tcphdr)], *op;
-        unsigned int i;
-
-        duprintf("tcp_match: finding option\n");
-
-        if (!optlen)
-                return invert;
-
-        /* If we don't have the whole header, drop packet. */
-        op = skb_header_pointer(skb,
-                                skb->nh.iph->ihl*4 + sizeof(struct tcphdr),
-                                optlen, _opt);
-        if (op == NULL) {
-                *hotdrop = 1;
-                return 0;
-        }
-
-        for (i = 0; i < optlen; ) {
-                if (op[i] == option) return !invert;
-                if (op[i] < 2) i++;
-                else i += op[i+1]?:1;
-        }
-
-        return invert;
-}
-
-static int
-tcp_match(const struct sk_buff *skb,
-          const struct net_device *in,
-          const struct net_device *out,
-          const void *matchinfo,
-          int offset,
-          int *hotdrop)
-{
-        struct tcphdr _tcph, *th;
-        const struct ipt_tcp *tcpinfo = matchinfo;
-
-        if (offset) {
-                /* To quote Alan:
-
-                   Don't allow a fragment of TCP 8 bytes in. Nobody normal
-                   causes this. Its a cracker trying to break in by doing a
-                   flag overwrite to pass the direction checks.
-                */
-                if (offset == 1) {
-                        duprintf("Dropping evil TCP offset=1 frag.\n");
-                        *hotdrop = 1;
-                }
-                /* Must not be a fragment. */
-                return 0;
-        }
-
-#define FWINVTCP(bool,invflg) ((bool) ^ !!(tcpinfo->invflags & invflg))
-
-        th = skb_header_pointer(skb, skb->nh.iph->ihl*4,
-                                sizeof(_tcph), &_tcph);
-        if (th == NULL) {
-                /* We've been asked to examine this packet, and we
-                   can't.  Hence, no choice but to drop. */
-                duprintf("Dropping evil TCP offset=0 tinygram.\n");
-                *hotdrop = 1;
-                return 0;
-        }
-
-        if (!port_match(tcpinfo->spts[0], tcpinfo->spts[1],
-                        ntohs(th->source),
-                        !!(tcpinfo->invflags & IPT_TCP_INV_SRCPT)))
-                return 0;
-        if (!port_match(tcpinfo->dpts[0], tcpinfo->dpts[1],
-                        ntohs(th->dest),
-                        !!(tcpinfo->invflags & IPT_TCP_INV_DSTPT)))
-                return 0;
-        if (!FWINVTCP((((unsigned char *)th)[13] & tcpinfo->flg_mask)
-                      == tcpinfo->flg_cmp,
-                      IPT_TCP_INV_FLAGS))
-                return 0;
-        if (tcpinfo->option) {
-                if (th->doff * 4 < sizeof(_tcph)) {
-                        *hotdrop = 1;
-                        return 0;
-                }
-                if (!tcp_find_option(tcpinfo->option, skb,
-                                     th->doff*4 - sizeof(_tcph),
-                                     tcpinfo->invflags & IPT_TCP_INV_OPTION,
-                                     hotdrop))
-                        return 0;
-        }
-        return 1;
-}
-
-/* Called when user tries to insert an entry of this type. */
-static int
-tcp_checkentry(const char *tablename,
-               const struct ipt_ip *ip,
-               void *matchinfo,
-               unsigned int matchsize,
-               unsigned int hook_mask)
-{
-        const struct ipt_tcp *tcpinfo = matchinfo;
-
-        /* Must specify proto == TCP, and no unknown invflags */
-        return ip->proto == IPPROTO_TCP
-                && !(ip->invflags & IPT_INV_PROTO)
-                && matchsize == IPT_ALIGN(sizeof(struct ipt_tcp))
-                && !(tcpinfo->invflags & ~IPT_TCP_INV_MASK);
-}
-
-static int
-udp_match(const struct sk_buff *skb,
-          const struct net_device *in,
-          const struct net_device *out,
-          const void *matchinfo,
-          int offset,
-          int *hotdrop)
-{
-        struct udphdr _udph, *uh;
-        const struct ipt_udp *udpinfo = matchinfo;
-
-        /* Must not be a fragment. */
-        if (offset)
-                return 0;
-
-        uh = skb_header_pointer(skb, skb->nh.iph->ihl*4,
-                                sizeof(_udph), &_udph);
-        if (uh == NULL) {
-                /* We've been asked to examine this packet, and we
-                   can't.  Hence, no choice but to drop. */
-                duprintf("Dropping evil UDP tinygram.\n");
-                *hotdrop = 1;
-                return 0;
-        }
-
-        return port_match(udpinfo->spts[0], udpinfo->spts[1],
-                          ntohs(uh->source),
-                          !!(udpinfo->invflags & IPT_UDP_INV_SRCPT))
-                && port_match(udpinfo->dpts[0], udpinfo->dpts[1],
-                              ntohs(uh->dest),
-                              !!(udpinfo->invflags & IPT_UDP_INV_DSTPT));
-}
-
-/* Called when user tries to insert an entry of this type. */
-static int
-udp_checkentry(const char *tablename,
-               const struct ipt_ip *ip,
-               void *matchinfo,
-               unsigned int matchinfosize,
-               unsigned int hook_mask)
-{
-        const struct ipt_udp *udpinfo = matchinfo;
-
-        /* Must specify proto == UDP, and no unknown invflags */
-        if (ip->proto != IPPROTO_UDP || (ip->invflags & IPT_INV_PROTO)) {
-                duprintf("ipt_udp: Protocol %u != %u\n", ip->proto,
-                         IPPROTO_UDP);
-                return 0;
-        }
-        if (matchinfosize != IPT_ALIGN(sizeof(struct ipt_udp))) {
-                duprintf("ipt_udp: matchsize %u != %u\n",
-                         matchinfosize, IPT_ALIGN(sizeof(struct ipt_udp)));
-                return 0;
-        }
-        if (udpinfo->invflags & ~IPT_UDP_INV_MASK) {
-                duprintf("ipt_udp: unknown flags %X\n",
-                         udpinfo->invflags);
-                return 0;
-        }
-
-        return 1;
+        loc_cpu_entry = private->entries[raw_smp_processor_id()];
+        IPT_ENTRY_ITERATE(loc_cpu_entry, private->size, cleanup_entry, NULL);
+        xt_free_table_info(private);
 }
 
 /* Returns 1 if the type and code is matched by the range, 0 otherwise */
@@ -1798,6 +1272,7 @@ icmp_match(const struct sk_buff *skb,
            const struct net_device *out,
            const void *matchinfo,
            int offset,
+           unsigned int protoff,
            int *hotdrop)
 {
         struct icmphdr _icmph, *ic;
@@ -1807,8 +1282,7 @@ icmp_match(const struct sk_buff *skb,
         if (offset)
                 return 0;
 
-        ic = skb_header_pointer(skb, skb->nh.iph->ihl*4,
-                                sizeof(_icmph), &_icmph);
+        ic = skb_header_pointer(skb, protoff, sizeof(_icmph), &_icmph);
         if (ic == NULL) {
                 /* We've been asked to examine this packet, and we
                  * can't.  Hence, no choice but to drop.
@@ -1828,11 +1302,12 @@ icmp_match(const struct sk_buff *skb,
 /* Called when user tries to insert an entry of this type. */
 static int
 icmp_checkentry(const char *tablename,
-           const struct ipt_ip *ip,
+           const void *info,
            void *matchinfo,
            unsigned int matchsize,
            unsigned int hook_mask)
 {
+        const struct ipt_ip *ip = info;
         const struct ipt_icmp *icmpinfo = matchinfo;
 
         /* Must specify proto == ICMP, and no unknown invflags */
@@ -1862,123 +1337,22 @@ static struct nf_sockopt_ops ipt_sockopts = {
         .get            = do_ipt_get_ctl,
 };
 
-static struct ipt_match tcp_matchstruct = {
-        .name           = "tcp",
-        .match          = &tcp_match,
-        .checkentry     = &tcp_checkentry,
-};
-
-static struct ipt_match udp_matchstruct = {
-        .name           = "udp",
-        .match          = &udp_match,
-        .checkentry     = &udp_checkentry,
-};
-
 static struct ipt_match icmp_matchstruct = {
         .name           = "icmp",
         .match          = &icmp_match,
         .checkentry     = &icmp_checkentry,
 };
 
-#ifdef CONFIG_PROC_FS
-static inline int print_name(const char *i,
-                             off_t start_offset, char *buffer, int length,
-                             off_t *pos, unsigned int *count)
-{
-        if ((*count)++ >= start_offset) {
-                unsigned int namelen;
-
-                namelen = sprintf(buffer + *pos, "%s\n",
-                                  i + sizeof(struct list_head));
-                if (*pos + namelen > length) {
-                        /* Stop iterating */
-                        return 1;
-                }
-                *pos += namelen;
-        }
-        return 0;
-}
-
-static inline int print_target(const struct ipt_target *t,
-                               off_t start_offset, char *buffer, int length,
-                               off_t *pos, unsigned int *count)
-{
-        if (t == &ipt_standard_target || t == &ipt_error_target)
-                return 0;
-        return print_name((char *)t, start_offset, buffer, length, pos, count);
-}
-
-static int ipt_get_tables(char *buffer, char **start, off_t offset, int length)
-{
-        off_t pos = 0;
-        unsigned int count = 0;
-
-        if (down_interruptible(&ipt_mutex) != 0)
-                return 0;
-
-        LIST_FIND(&ipt_tables, print_name, void *,
-                  offset, buffer, length, &pos, &count);
-
-        up(&ipt_mutex);
-
-        /* `start' hack - see fs/proc/generic.c line ~105 */
-        *start=(char *)((unsigned long)count-offset);
-        return pos;
-}
-
-static int ipt_get_targets(char *buffer, char **start, off_t offset, int length)
-{
-        off_t pos = 0;
-        unsigned int count = 0;
-
-        if (down_interruptible(&ipt_mutex) != 0)
-                return 0;
-
-        LIST_FIND(&ipt_target, print_target, struct ipt_target *,
-                  offset, buffer, length, &pos, &count);
-        
-        up(&ipt_mutex);
-
-        *start = (char *)((unsigned long)count - offset);
-        return pos;
-}
-
-static int ipt_get_matches(char *buffer, char **start, off_t offset, int length)
-{
-        off_t pos = 0;
-        unsigned int count = 0;
-
-        if (down_interruptible(&ipt_mutex) != 0)
-                return 0;
-        
-        LIST_FIND(&ipt_match, print_name, void *,
-                  offset, buffer, length, &pos, &count);
-
-        up(&ipt_mutex);
-
-        *start = (char *)((unsigned long)count - offset);
-        return pos;
-}
-
-static const struct { char *name; get_info_t *get_info; } ipt_proc_entry[] =
-{ { "ip_tables_names", ipt_get_tables },
-  { "ip_tables_targets", ipt_get_targets },
-  { "ip_tables_matches", ipt_get_matches },
-  { NULL, NULL} };
-#endif /*CONFIG_PROC_FS*/
-
 static int __init init(void)
 {
         int ret;
 
+        xt_proto_init(AF_INET);
+
         /* Noone else will be downing sem now, so we won't sleep */
-        down(&ipt_mutex);
-        list_append(&ipt_target, &ipt_standard_target);
-        list_append(&ipt_target, &ipt_error_target);
-        list_append(&ipt_match, &tcp_matchstruct);
-        list_append(&ipt_match, &udp_matchstruct);
-        list_append(&ipt_match, &icmp_matchstruct);
-        up(&ipt_mutex);
+        xt_register_target(AF_INET, &ipt_standard_target);
+        xt_register_target(AF_INET, &ipt_error_target);
+        xt_register_match(AF_INET, &icmp_matchstruct);
 
         /* Register setsockopt */
         ret = nf_register_sockopt(&ipt_sockopts);
@@ -1987,49 +1361,23 @@ static int __init init(void)
                 return ret;
         }
 
-#ifdef CONFIG_PROC_FS
-        {
-        struct proc_dir_entry *proc;
-        int i;
-
-        for (i = 0; ipt_proc_entry[i].name; i++) {
-                proc = proc_net_create(ipt_proc_entry[i].name, 0,
-                                       ipt_proc_entry[i].get_info);
-                if (!proc) {
-                        while (--i >= 0)
-                                proc_net_remove(ipt_proc_entry[i].name);
-                        nf_unregister_sockopt(&ipt_sockopts);
-                        return -ENOMEM;
-                }
-                proc->owner = THIS_MODULE;
-        }
-        }
-#endif
-
-        printk("ip_tables: (C) 2000-2002 Netfilter core team\n");
+        printk("ip_tables: (C) 2000-2006 Netfilter Core Team\n");
         return 0;
 }
 
 static void __exit fini(void)
 {
         nf_unregister_sockopt(&ipt_sockopts);
-#ifdef CONFIG_PROC_FS
-        {
-        int i;
-        for (i = 0; ipt_proc_entry[i].name; i++)
-                proc_net_remove(ipt_proc_entry[i].name);
-        }
-#endif
+
+        xt_unregister_match(AF_INET, &icmp_matchstruct);
+        xt_unregister_target(AF_INET, &ipt_error_target);
+        xt_unregister_target(AF_INET, &ipt_standard_target);
+
+        xt_proto_fini(AF_INET);
 }
 
 EXPORT_SYMBOL(ipt_register_table);
 EXPORT_SYMBOL(ipt_unregister_table);
-EXPORT_SYMBOL(ipt_register_match);
-EXPORT_SYMBOL(ipt_unregister_match);
 EXPORT_SYMBOL(ipt_do_table);
-EXPORT_SYMBOL(ipt_register_target);
-EXPORT_SYMBOL(ipt_unregister_target);
-EXPORT_SYMBOL(ipt_find_target);
-
 module_init(init);
 module_exit(fini);