IPv6: fix race between cleanup and add/delete address
[linux-2.6.git] / net / netfilter / x_tables.c
index a657ab5..0a12ced 100644 (file)
@@ -13,7 +13,6 @@
  *
  */
 
-#include <linux/config.h>
 #include <linux/kernel.h>
 #include <linux/socket.h>
 #include <linux/net.h>
 #include <linux/string.h>
 #include <linux/vmalloc.h>
 #include <linux/mutex.h>
+#include <linux/mm.h>
+#include <net/net_namespace.h>
 
 #include <linux/netfilter/x_tables.h>
 #include <linux/netfilter_arp.h>
-
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv6/ip6_tables.h>
+#include <linux/netfilter_arp/arp_tables.h>
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
-MODULE_DESCRIPTION("[ip,ip6,arp]_tables backend module");
+MODULE_DESCRIPTION("{ip,ip6,arp,eb}_tables backend module");
 
 #define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
 
+struct compat_delta {
+       struct compat_delta *next;
+       unsigned int offset;
+       int delta;
+};
+
 struct xt_af {
        struct mutex mutex;
        struct list_head match;
        struct list_head target;
-       struct list_head tables;
+#ifdef CONFIG_COMPAT
+       struct mutex compat_mutex;
+       struct compat_delta *compat_offsets;
+#endif
 };
 
 static struct xt_af *xt;
@@ -48,23 +60,20 @@ static struct xt_af *xt;
 #define duprintf(format, args...)
 #endif
 
-enum {
-       TABLE,
-       TARGET,
-       MATCH,
-};
-
-static const char *xt_prefix[NPROTO] = {
-       [AF_INET]       = "ip",
-       [AF_INET6]      = "ip6",
-       [NF_ARP]        = "arp",
+static const char *const xt_prefix[NFPROTO_NUMPROTO] = {
+       [NFPROTO_UNSPEC] = "x",
+       [NFPROTO_IPV4]   = "ip",
+       [NFPROTO_ARP]    = "arp",
+       [NFPROTO_BRIDGE] = "eb",
+       [NFPROTO_IPV6]   = "ip6",
 };
 
 /* Registration hooks for targets. */
 int
 xt_register_target(struct xt_target *target)
 {
-       int ret, af = target->family;
+       u_int8_t af = target->family;
+       int ret;
 
        ret = mutex_lock_interruptible(&xt[af].mutex);
        if (ret != 0)
@@ -78,18 +87,49 @@ EXPORT_SYMBOL(xt_register_target);
 void
 xt_unregister_target(struct xt_target *target)
 {
-       int af = target->family;
+       u_int8_t af = target->family;
 
        mutex_lock(&xt[af].mutex);
-       LIST_DELETE(&xt[af].target, target);
+       list_del(&target->list);
        mutex_unlock(&xt[af].mutex);
 }
 EXPORT_SYMBOL(xt_unregister_target);
 
 int
+xt_register_targets(struct xt_target *target, unsigned int n)
+{
+       unsigned int i;
+       int err = 0;
+
+       for (i = 0; i < n; i++) {
+               err = xt_register_target(&target[i]);
+               if (err)
+                       goto err;
+       }
+       return err;
+
+err:
+       if (i > 0)
+               xt_unregister_targets(target, i);
+       return err;
+}
+EXPORT_SYMBOL(xt_register_targets);
+
+void
+xt_unregister_targets(struct xt_target *target, unsigned int n)
+{
+       unsigned int i;
+
+       for (i = 0; i < n; i++)
+               xt_unregister_target(&target[i]);
+}
+EXPORT_SYMBOL(xt_unregister_targets);
+
+int
 xt_register_match(struct xt_match *match)
 {
-       int ret, af = match->family;
+       u_int8_t af = match->family;
+       int ret;
 
        ret = mutex_lock_interruptible(&xt[af].mutex);
        if (ret != 0)
@@ -105,14 +145,44 @@ EXPORT_SYMBOL(xt_register_match);
 void
 xt_unregister_match(struct xt_match *match)
 {
-       int af =  match->family;
+       u_int8_t af = match->family;
 
        mutex_lock(&xt[af].mutex);
-       LIST_DELETE(&xt[af].match, match);
+       list_del(&match->list);
        mutex_unlock(&xt[af].mutex);
 }
 EXPORT_SYMBOL(xt_unregister_match);
 
+int
+xt_register_matches(struct xt_match *match, unsigned int n)
+{
+       unsigned int i;
+       int err = 0;
+
+       for (i = 0; i < n; i++) {
+               err = xt_register_match(&match[i]);
+               if (err)
+                       goto err;
+       }
+       return err;
+
+err:
+       if (i > 0)
+               xt_unregister_matches(match, i);
+       return err;
+}
+EXPORT_SYMBOL(xt_register_matches);
+
+void
+xt_unregister_matches(struct xt_match *match, unsigned int n)
+{
+       unsigned int i;
+
+       for (i = 0; i < n; i++)
+               xt_unregister_match(&match[i]);
+}
+EXPORT_SYMBOL(xt_unregister_matches);
+
 
 /*
  * These are weird, but module loading must not be done with mutex
@@ -121,7 +191,7 @@ EXPORT_SYMBOL(xt_unregister_match);
  */
 
 /* Find match, grabs ref.  Returns ERR_PTR() on error. */
-struct xt_match *xt_find_match(int af, const char *name, u8 revision)
+struct xt_match *xt_find_match(u8 af, const char *name, u8 revision)
 {
        struct xt_match *m;
        int err = 0;
@@ -141,12 +211,17 @@ struct xt_match *xt_find_match(int af, const char *name, u8 revision)
                }
        }
        mutex_unlock(&xt[af].mutex);
+
+       if (af != NFPROTO_UNSPEC)
+               /* Try searching again in the family-independent list */
+               return xt_find_match(NFPROTO_UNSPEC, name, revision);
+
        return ERR_PTR(err);
 }
 EXPORT_SYMBOL(xt_find_match);
 
 /* Find target, grabs ref.  Returns ERR_PTR() on error. */
-struct xt_target *xt_find_target(int af, const char *name, u8 revision)
+struct xt_target *xt_find_target(u8 af, const char *name, u8 revision)
 {
        struct xt_target *t;
        int err = 0;
@@ -166,11 +241,16 @@ struct xt_target *xt_find_target(int af, const char *name, u8 revision)
                }
        }
        mutex_unlock(&xt[af].mutex);
+
+       if (af != NFPROTO_UNSPEC)
+               /* Try searching again in the family-independent list */
+               return xt_find_target(NFPROTO_UNSPEC, name, revision);
+
        return ERR_PTR(err);
 }
 EXPORT_SYMBOL(xt_find_target);
 
-struct xt_target *xt_request_find_target(int af, const char *name, u8 revision)
+struct xt_target *xt_request_find_target(u8 af, const char *name, u8 revision)
 {
        struct xt_target *target;
 
@@ -182,9 +262,9 @@ struct xt_target *xt_request_find_target(int af, const char *name, u8 revision)
 }
 EXPORT_SYMBOL_GPL(xt_request_find_target);
 
-static int match_revfn(int af, const char *name, u8 revision, int *bestp)
+static int match_revfn(u8 af, const char *name, u8 revision, int *bestp)
 {
-       struct xt_match *m;
+       const struct xt_match *m;
        int have_rev = 0;
 
        list_for_each_entry(m, &xt[af].match, list) {
@@ -195,12 +275,16 @@ static int match_revfn(int af, const char *name, u8 revision, int *bestp)
                                have_rev = 1;
                }
        }
+
+       if (af != NFPROTO_UNSPEC && !have_rev)
+               return match_revfn(NFPROTO_UNSPEC, name, revision, bestp);
+
        return have_rev;
 }
 
-static int target_revfn(int af, const char *name, u8 revision, int *bestp)
+static int target_revfn(u8 af, const char *name, u8 revision, int *bestp)
 {
-       struct xt_target *t;
+       const struct xt_target *t;
        int have_rev = 0;
 
        list_for_each_entry(t, &xt[af].target, list) {
@@ -211,11 +295,15 @@ static int target_revfn(int af, const char *name, u8 revision, int *bestp)
                                have_rev = 1;
                }
        }
+
+       if (af != NFPROTO_UNSPEC && !have_rev)
+               return target_revfn(NFPROTO_UNSPEC, name, revision, bestp);
+
        return have_rev;
 }
 
 /* Returns true or false (if no such extension at all) */
-int xt_find_revision(int af, const char *name, u8 revision, int target,
+int xt_find_revision(u8 af, const char *name, u8 revision, int target,
                     int *err)
 {
        int have_rev, best = -1;
@@ -243,80 +331,308 @@ int xt_find_revision(int af, const char *name, u8 revision, int target,
 }
 EXPORT_SYMBOL_GPL(xt_find_revision);
 
-int xt_check_match(const struct xt_match *match, unsigned short family,
-                   unsigned int size, const char *table, unsigned int hook_mask,
-                  unsigned short proto, int inv_proto)
+static char *textify_hooks(char *buf, size_t size, unsigned int mask)
+{
+       static const char *const names[] = {
+               "PREROUTING", "INPUT", "FORWARD",
+               "OUTPUT", "POSTROUTING", "BROUTING",
+       };
+       unsigned int i;
+       char *p = buf;
+       bool np = false;
+       int res;
+
+       *p = '\0';
+       for (i = 0; i < ARRAY_SIZE(names); ++i) {
+               if (!(mask & (1 << i)))
+                       continue;
+               res = snprintf(p, size, "%s%s", np ? "/" : "", names[i]);
+               if (res > 0) {
+                       size -= res;
+                       p += res;
+               }
+               np = true;
+       }
+
+       return buf;
+}
+
+int xt_check_match(struct xt_mtchk_param *par,
+                  unsigned int size, u_int8_t proto, bool inv_proto)
 {
-       if (XT_ALIGN(match->matchsize) != size) {
-               printk("%s_tables: %s match: invalid size %Zu != %u\n",
-                      xt_prefix[family], match->name,
-                      XT_ALIGN(match->matchsize), size);
+       if (XT_ALIGN(par->match->matchsize) != size &&
+           par->match->matchsize != -1) {
+               /*
+                * ebt_among is exempt from centralized matchsize checking
+                * because it uses a dynamic-size data set.
+                */
+               pr_err("%s_tables: %s.%u match: invalid size "
+                      "%u (kernel) != (user) %u\n",
+                      xt_prefix[par->family], par->match->name,
+                      par->match->revision,
+                      XT_ALIGN(par->match->matchsize), size);
                return -EINVAL;
        }
-       if (match->table && strcmp(match->table, table)) {
-               printk("%s_tables: %s match: only valid in %s table, not %s\n",
-                      xt_prefix[family], match->name, match->table, table);
+       if (par->match->table != NULL &&
+           strcmp(par->match->table, par->table) != 0) {
+               pr_err("%s_tables: %s match: only valid in %s table, not %s\n",
+                      xt_prefix[par->family], par->match->name,
+                      par->match->table, par->table);
                return -EINVAL;
        }
-       if (match->hooks && (hook_mask & ~match->hooks) != 0) {
-               printk("%s_tables: %s match: bad hook_mask %u\n",
-                      xt_prefix[family], match->name, hook_mask);
+       if (par->match->hooks && (par->hook_mask & ~par->match->hooks) != 0) {
+               char used[64], allow[64];
+
+               pr_err("%s_tables: %s match: used from hooks %s, but only "
+                      "valid from %s\n",
+                      xt_prefix[par->family], par->match->name,
+                      textify_hooks(used, sizeof(used), par->hook_mask),
+                      textify_hooks(allow, sizeof(allow), par->match->hooks));
                return -EINVAL;
        }
-       if (match->proto && (match->proto != proto || inv_proto)) {
-               printk("%s_tables: %s match: only valid for protocol %u\n",
-                      xt_prefix[family], match->name, match->proto);
+       if (par->match->proto && (par->match->proto != proto || inv_proto)) {
+               pr_err("%s_tables: %s match: only valid for protocol %u\n",
+                      xt_prefix[par->family], par->match->name,
+                      par->match->proto);
                return -EINVAL;
        }
+       if (par->match->checkentry != NULL && !par->match->checkentry(par))
+               return -EINVAL;
        return 0;
 }
 EXPORT_SYMBOL_GPL(xt_check_match);
 
-int xt_check_target(const struct xt_target *target, unsigned short family,
-                   unsigned int size, const char *table, unsigned int hook_mask,
-                   unsigned short proto, int inv_proto)
+#ifdef CONFIG_COMPAT
+int xt_compat_add_offset(u_int8_t af, unsigned int offset, short delta)
+{
+       struct compat_delta *tmp;
+
+       tmp = kmalloc(sizeof(struct compat_delta), GFP_KERNEL);
+       if (!tmp)
+               return -ENOMEM;
+
+       tmp->offset = offset;
+       tmp->delta = delta;
+
+       if (xt[af].compat_offsets) {
+               tmp->next = xt[af].compat_offsets->next;
+               xt[af].compat_offsets->next = tmp;
+       } else {
+               xt[af].compat_offsets = tmp;
+               tmp->next = NULL;
+       }
+       return 0;
+}
+EXPORT_SYMBOL_GPL(xt_compat_add_offset);
+
+void xt_compat_flush_offsets(u_int8_t af)
 {
-       if (XT_ALIGN(target->targetsize) != size) {
-               printk("%s_tables: %s target: invalid size %Zu != %u\n",
-                      xt_prefix[family], target->name,
-                      XT_ALIGN(target->targetsize), size);
+       struct compat_delta *tmp, *next;
+
+       if (xt[af].compat_offsets) {
+               for (tmp = xt[af].compat_offsets; tmp; tmp = next) {
+                       next = tmp->next;
+                       kfree(tmp);
+               }
+               xt[af].compat_offsets = NULL;
+       }
+}
+EXPORT_SYMBOL_GPL(xt_compat_flush_offsets);
+
+int xt_compat_calc_jump(u_int8_t af, unsigned int offset)
+{
+       struct compat_delta *tmp;
+       int delta;
+
+       for (tmp = xt[af].compat_offsets, delta = 0; tmp; tmp = tmp->next)
+               if (tmp->offset < offset)
+                       delta += tmp->delta;
+       return delta;
+}
+EXPORT_SYMBOL_GPL(xt_compat_calc_jump);
+
+int xt_compat_match_offset(const struct xt_match *match)
+{
+       u_int16_t csize = match->compatsize ? : match->matchsize;
+       return XT_ALIGN(match->matchsize) - COMPAT_XT_ALIGN(csize);
+}
+EXPORT_SYMBOL_GPL(xt_compat_match_offset);
+
+int xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr,
+                             unsigned int *size)
+{
+       const struct xt_match *match = m->u.kernel.match;
+       struct compat_xt_entry_match *cm = (struct compat_xt_entry_match *)m;
+       int pad, off = xt_compat_match_offset(match);
+       u_int16_t msize = cm->u.user.match_size;
+
+       m = *dstptr;
+       memcpy(m, cm, sizeof(*cm));
+       if (match->compat_from_user)
+               match->compat_from_user(m->data, cm->data);
+       else
+               memcpy(m->data, cm->data, msize - sizeof(*cm));
+       pad = XT_ALIGN(match->matchsize) - match->matchsize;
+       if (pad > 0)
+               memset(m->data + match->matchsize, 0, pad);
+
+       msize += off;
+       m->u.user.match_size = msize;
+
+       *size += off;
+       *dstptr += msize;
+       return 0;
+}
+EXPORT_SYMBOL_GPL(xt_compat_match_from_user);
+
+int xt_compat_match_to_user(const struct xt_entry_match *m,
+                           void __user **dstptr, unsigned int *size)
+{
+       const struct xt_match *match = m->u.kernel.match;
+       struct compat_xt_entry_match __user *cm = *dstptr;
+       int off = xt_compat_match_offset(match);
+       u_int16_t msize = m->u.user.match_size - off;
+
+       if (copy_to_user(cm, m, sizeof(*cm)) ||
+           put_user(msize, &cm->u.user.match_size) ||
+           copy_to_user(cm->u.user.name, m->u.kernel.match->name,
+                        strlen(m->u.kernel.match->name) + 1))
+               return -EFAULT;
+
+       if (match->compat_to_user) {
+               if (match->compat_to_user((void __user *)cm->data, m->data))
+                       return -EFAULT;
+       } else {
+               if (copy_to_user(cm->data, m->data, msize - sizeof(*cm)))
+                       return -EFAULT;
+       }
+
+       *size -= off;
+       *dstptr += msize;
+       return 0;
+}
+EXPORT_SYMBOL_GPL(xt_compat_match_to_user);
+#endif /* CONFIG_COMPAT */
+
+int xt_check_target(struct xt_tgchk_param *par,
+                   unsigned int size, u_int8_t proto, bool inv_proto)
+{
+       if (XT_ALIGN(par->target->targetsize) != size) {
+               pr_err("%s_tables: %s.%u target: invalid size "
+                      "%u (kernel) != (user) %u\n",
+                      xt_prefix[par->family], par->target->name,
+                      par->target->revision,
+                      XT_ALIGN(par->target->targetsize), size);
                return -EINVAL;
        }
-       if (target->table && strcmp(target->table, table)) {
-               printk("%s_tables: %s target: only valid in %s table, not %s\n",
-                      xt_prefix[family], target->name, target->table, table);
+       if (par->target->table != NULL &&
+           strcmp(par->target->table, par->table) != 0) {
+               pr_err("%s_tables: %s target: only valid in %s table, not %s\n",
+                      xt_prefix[par->family], par->target->name,
+                      par->target->table, par->table);
                return -EINVAL;
        }
-       if (target->hooks && (hook_mask & ~target->hooks) != 0) {
-               printk("%s_tables: %s target: bad hook_mask %u\n",
-                      xt_prefix[family], target->name, hook_mask);
+       if (par->target->hooks && (par->hook_mask & ~par->target->hooks) != 0) {
+               char used[64], allow[64];
+
+               pr_err("%s_tables: %s target: used from hooks %s, but only "
+                      "usable from %s\n",
+                      xt_prefix[par->family], par->target->name,
+                      textify_hooks(used, sizeof(used), par->hook_mask),
+                      textify_hooks(allow, sizeof(allow), par->target->hooks));
                return -EINVAL;
        }
-       if (target->proto && (target->proto != proto || inv_proto)) {
-               printk("%s_tables: %s target: only valid for protocol %u\n",
-                      xt_prefix[family], target->name, target->proto);
+       if (par->target->proto && (par->target->proto != proto || inv_proto)) {
+               pr_err("%s_tables: %s target: only valid for protocol %u\n",
+                      xt_prefix[par->family], par->target->name,
+                      par->target->proto);
                return -EINVAL;
        }
+       if (par->target->checkentry != NULL && !par->target->checkentry(par))
+               return -EINVAL;
        return 0;
 }
 EXPORT_SYMBOL_GPL(xt_check_target);
 
+#ifdef CONFIG_COMPAT
+int xt_compat_target_offset(const struct xt_target *target)
+{
+       u_int16_t csize = target->compatsize ? : target->targetsize;
+       return XT_ALIGN(target->targetsize) - COMPAT_XT_ALIGN(csize);
+}
+EXPORT_SYMBOL_GPL(xt_compat_target_offset);
+
+void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr,
+                               unsigned int *size)
+{
+       const struct xt_target *target = t->u.kernel.target;
+       struct compat_xt_entry_target *ct = (struct compat_xt_entry_target *)t;
+       int pad, off = xt_compat_target_offset(target);
+       u_int16_t tsize = ct->u.user.target_size;
+
+       t = *dstptr;
+       memcpy(t, ct, sizeof(*ct));
+       if (target->compat_from_user)
+               target->compat_from_user(t->data, ct->data);
+       else
+               memcpy(t->data, ct->data, tsize - sizeof(*ct));
+       pad = XT_ALIGN(target->targetsize) - target->targetsize;
+       if (pad > 0)
+               memset(t->data + target->targetsize, 0, pad);
+
+       tsize += off;
+       t->u.user.target_size = tsize;
+
+       *size += off;
+       *dstptr += tsize;
+}
+EXPORT_SYMBOL_GPL(xt_compat_target_from_user);
+
+int xt_compat_target_to_user(const struct xt_entry_target *t,
+                            void __user **dstptr, unsigned int *size)
+{
+       const struct xt_target *target = t->u.kernel.target;
+       struct compat_xt_entry_target __user *ct = *dstptr;
+       int off = xt_compat_target_offset(target);
+       u_int16_t tsize = t->u.user.target_size - off;
+
+       if (copy_to_user(ct, t, sizeof(*ct)) ||
+           put_user(tsize, &ct->u.user.target_size) ||
+           copy_to_user(ct->u.user.name, t->u.kernel.target->name,
+                        strlen(t->u.kernel.target->name) + 1))
+               return -EFAULT;
+
+       if (target->compat_to_user) {
+               if (target->compat_to_user((void __user *)ct->data, t->data))
+                       return -EFAULT;
+       } else {
+               if (copy_to_user(ct->data, t->data, tsize - sizeof(*ct)))
+                       return -EFAULT;
+       }
+
+       *size -= off;
+       *dstptr += tsize;
+       return 0;
+}
+EXPORT_SYMBOL_GPL(xt_compat_target_to_user);
+#endif
+
 struct xt_table_info *xt_alloc_table_info(unsigned int size)
 {
        struct xt_table_info *newinfo;
        int cpu;
 
        /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */
-       if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > num_physpages)
+       if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > totalram_pages)
                return NULL;
 
-       newinfo = kzalloc(sizeof(struct xt_table_info), GFP_KERNEL);
+       newinfo = kzalloc(XT_TABLE_INFO_SZ, GFP_KERNEL);
        if (!newinfo)
                return NULL;
 
        newinfo->size = size;
 
-       for_each_cpu(cpu) {
+       for_each_possible_cpu(cpu) {
                if (size <= PAGE_SIZE)
                        newinfo->entries[cpu] = kmalloc_node(size,
                                                        GFP_KERNEL,
@@ -339,7 +655,7 @@ void xt_free_table_info(struct xt_table_info *info)
 {
        int cpu;
 
-       for_each_cpu(cpu) {
+       for_each_possible_cpu(cpu) {
                if (info->size <= PAGE_SIZE)
                        kfree(info->entries[cpu]);
                else
@@ -350,14 +666,15 @@ void xt_free_table_info(struct xt_table_info *info)
 EXPORT_SYMBOL(xt_free_table_info);
 
 /* Find table by name, grabs mutex & ref.  Returns ERR_PTR() on error. */
-struct xt_table *xt_find_table_lock(int af, const char *name)
+struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af,
+                                   const char *name)
 {
        struct xt_table *t;
 
        if (mutex_lock_interruptible(&xt[af].mutex) != 0)
                return ERR_PTR(-EINTR);
 
-       list_for_each_entry(t, &xt[af].tables, list)
+       list_for_each_entry(t, &net->xt.tables[af], list)
                if (strcmp(t->name, name) == 0 && try_module_get(t->me))
                        return t;
        mutex_unlock(&xt[af].mutex);
@@ -371,6 +688,23 @@ void xt_table_unlock(struct xt_table *table)
 }
 EXPORT_SYMBOL_GPL(xt_table_unlock);
 
+#ifdef CONFIG_COMPAT
+void xt_compat_lock(u_int8_t af)
+{
+       mutex_lock(&xt[af].compat_mutex);
+}
+EXPORT_SYMBOL_GPL(xt_compat_lock);
+
+void xt_compat_unlock(u_int8_t af)
+{
+       mutex_unlock(&xt[af].compat_mutex);
+}
+EXPORT_SYMBOL_GPL(xt_compat_unlock);
+#endif
+
+DEFINE_PER_CPU(struct xt_info_lock, xt_info_locks);
+EXPORT_PER_CPU_SYMBOL_GPL(xt_info_locks);
+
 
 struct xt_table_info *
 xt_replace_table(struct xt_table *table,
@@ -378,47 +712,67 @@ xt_replace_table(struct xt_table *table,
              struct xt_table_info *newinfo,
              int *error)
 {
-       struct xt_table_info *oldinfo, *private;
+       struct xt_table_info *private;
 
        /* Do the substitution. */
-       write_lock_bh(&table->lock);
+       local_bh_disable();
        private = table->private;
+
        /* Check inside lock: is the old number correct? */
        if (num_counters != private->number) {
                duprintf("num_counters != table->private->number (%u/%u)\n",
                         num_counters, private->number);
-               write_unlock_bh(&table->lock);
+               local_bh_enable();
                *error = -EAGAIN;
                return NULL;
        }
-       oldinfo = private;
+
        table->private = newinfo;
-       newinfo->initial_entries = oldinfo->initial_entries;
-       write_unlock_bh(&table->lock);
+       newinfo->initial_entries = private->initial_entries;
 
-       return oldinfo;
+       /*
+        * Even though table entries have now been swapped, other CPU's
+        * may still be using the old entries. This is okay, because
+        * resynchronization happens because of the locking done
+        * during the get_counters() routine.
+        */
+       local_bh_enable();
+
+       return private;
 }
 EXPORT_SYMBOL_GPL(xt_replace_table);
 
-int xt_register_table(struct xt_table *table,
-                     struct xt_table_info *bootstrap,
-                     struct xt_table_info *newinfo)
+struct xt_table *xt_register_table(struct net *net,
+                                  const struct xt_table *input_table,
+                                  struct xt_table_info *bootstrap,
+                                  struct xt_table_info *newinfo)
 {
        int ret;
        struct xt_table_info *private;
+       struct xt_table *t, *table;
+
+       /* Don't add one object to multiple lists. */
+       table = kmemdup(input_table, sizeof(struct xt_table), GFP_KERNEL);
+       if (!table) {
+               ret = -ENOMEM;
+               goto out;
+       }
 
        ret = mutex_lock_interruptible(&xt[table->af].mutex);
        if (ret != 0)
-               return ret;
+               goto out_free;
 
        /* Don't autoload: we'd eat our tail... */
-       if (list_named_find(&xt[table->af].tables, table->name)) {
-               ret = -EEXIST;
-               goto unlock;
+       list_for_each_entry(t, &net->xt.tables[table->af], list) {
+               if (strcmp(t->name, table->name) == 0) {
+                       ret = -EEXIST;
+                       goto unlock;
+               }
        }
 
        /* Simplifies replace_table code. */
        table->private = bootstrap;
+
        if (!xt_replace_table(table, 0, newinfo, &ret))
                goto unlock;
 
@@ -428,13 +782,16 @@ int xt_register_table(struct xt_table *table,
        /* save number of initial entries */
        private->initial_entries = private->number;
 
-       rwlock_init(&table->lock);
-       list_prepend(&xt[table->af].tables, table);
+       list_add(&table->list, &net->xt.tables[table->af]);
+       mutex_unlock(&xt[table->af].mutex);
+       return table;
 
-       ret = 0;
  unlock:
        mutex_unlock(&xt[table->af].mutex);
-       return ret;
+out_free:
+       kfree(table);
+out:
+       return ERR_PTR(ret);
 }
 EXPORT_SYMBOL_GPL(xt_register_table);
 
@@ -444,141 +801,294 @@ void *xt_unregister_table(struct xt_table *table)
 
        mutex_lock(&xt[table->af].mutex);
        private = table->private;
-       LIST_DELETE(&xt[table->af].tables, table);
+       list_del(&table->list);
        mutex_unlock(&xt[table->af].mutex);
+       kfree(table);
 
        return private;
 }
 EXPORT_SYMBOL_GPL(xt_unregister_table);
 
 #ifdef CONFIG_PROC_FS
-static char *xt_proto_prefix[NPROTO] = {
-       [AF_INET]       = "ip",
-       [AF_INET6]      = "ip6",
-       [NF_ARP]        = "arp",
+struct xt_names_priv {
+       struct seq_net_private p;
+       u_int8_t af;
 };
+static void *xt_table_seq_start(struct seq_file *seq, loff_t *pos)
+{
+       struct xt_names_priv *priv = seq->private;
+       struct net *net = seq_file_net(seq);
+       u_int8_t af = priv->af;
+
+       mutex_lock(&xt[af].mutex);
+       return seq_list_start(&net->xt.tables[af], *pos);
+}
 
-static struct list_head *xt_get_idx(struct list_head *list, struct seq_file *seq, loff_t pos)
+static void *xt_table_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
-       struct list_head *head = list->next;
+       struct xt_names_priv *priv = seq->private;
+       struct net *net = seq_file_net(seq);
+       u_int8_t af = priv->af;
 
-       if (!head || list_empty(list))
-               return NULL;
+       return seq_list_next(v, &net->xt.tables[af], pos);
+}
 
-       while (pos && (head = head->next)) {
-               if (head == list)
-                       return NULL;
-               pos--;
-       }
-       return pos ? NULL : head;
+static void xt_table_seq_stop(struct seq_file *seq, void *v)
+{
+       struct xt_names_priv *priv = seq->private;
+       u_int8_t af = priv->af;
+
+       mutex_unlock(&xt[af].mutex);
 }
 
-static struct list_head *type2list(u_int16_t af, u_int16_t type)
+static int xt_table_seq_show(struct seq_file *seq, void *v)
 {
-       struct list_head *list;
+       struct xt_table *table = list_entry(v, struct xt_table, list);
 
-       switch (type) {
-       case TARGET:
-               list = &xt[af].target;
-               break;
-       case MATCH:
-               list = &xt[af].match;
-               break;
-       case TABLE:
-               list = &xt[af].tables;
+       if (strlen(table->name))
+               return seq_printf(seq, "%s\n", table->name);
+       else
+               return 0;
+}
+
+static const struct seq_operations xt_table_seq_ops = {
+       .start  = xt_table_seq_start,
+       .next   = xt_table_seq_next,
+       .stop   = xt_table_seq_stop,
+       .show   = xt_table_seq_show,
+};
+
+static int xt_table_open(struct inode *inode, struct file *file)
+{
+       int ret;
+       struct xt_names_priv *priv;
+
+       ret = seq_open_net(inode, file, &xt_table_seq_ops,
+                          sizeof(struct xt_names_priv));
+       if (!ret) {
+               priv = ((struct seq_file *)file->private_data)->private;
+               priv->af = (unsigned long)PDE(inode)->data;
+       }
+       return ret;
+}
+
+static const struct file_operations xt_table_ops = {
+       .owner   = THIS_MODULE,
+       .open    = xt_table_open,
+       .read    = seq_read,
+       .llseek  = seq_lseek,
+       .release = seq_release_net,
+};
+
+/*
+ * Traverse state for ip{,6}_{tables,matches} for helping crossing
+ * the multi-AF mutexes.
+ */
+struct nf_mttg_trav {
+       struct list_head *head, *curr;
+       uint8_t class, nfproto;
+};
+
+enum {
+       MTTG_TRAV_INIT,
+       MTTG_TRAV_NFP_UNSPEC,
+       MTTG_TRAV_NFP_SPEC,
+       MTTG_TRAV_DONE,
+};
+
+static void *xt_mttg_seq_next(struct seq_file *seq, void *v, loff_t *ppos,
+    bool is_target)
+{
+       static const uint8_t next_class[] = {
+               [MTTG_TRAV_NFP_UNSPEC] = MTTG_TRAV_NFP_SPEC,
+               [MTTG_TRAV_NFP_SPEC]   = MTTG_TRAV_DONE,
+       };
+       struct nf_mttg_trav *trav = seq->private;
+
+       switch (trav->class) {
+       case MTTG_TRAV_INIT:
+               trav->class = MTTG_TRAV_NFP_UNSPEC;
+               mutex_lock(&xt[NFPROTO_UNSPEC].mutex);
+               trav->head = trav->curr = is_target ?
+                       &xt[NFPROTO_UNSPEC].target : &xt[NFPROTO_UNSPEC].match;
+               break;
+       case MTTG_TRAV_NFP_UNSPEC:
+               trav->curr = trav->curr->next;
+               if (trav->curr != trav->head)
+                       break;
+               mutex_unlock(&xt[NFPROTO_UNSPEC].mutex);
+               mutex_lock(&xt[trav->nfproto].mutex);
+               trav->head = trav->curr = is_target ?
+                       &xt[trav->nfproto].target : &xt[trav->nfproto].match;
+               trav->class = next_class[trav->class];
                break;
+       case MTTG_TRAV_NFP_SPEC:
+               trav->curr = trav->curr->next;
+               if (trav->curr != trav->head)
+                       break;
+               /* fallthru, _stop will unlock */
        default:
-               list = NULL;
-               break;
+               return NULL;
        }
 
-       return list;
+       if (ppos != NULL)
+               ++*ppos;
+       return trav;
 }
 
-static void *xt_tgt_seq_start(struct seq_file *seq, loff_t *pos)
+static void *xt_mttg_seq_start(struct seq_file *seq, loff_t *pos,
+    bool is_target)
 {
-       struct proc_dir_entry *pde = (struct proc_dir_entry *) seq->private;
-       u_int16_t af = (unsigned long)pde->data & 0xffff;
-       u_int16_t type = (unsigned long)pde->data >> 16;
-       struct list_head *list;
+       struct nf_mttg_trav *trav = seq->private;
+       unsigned int j;
 
-       if (af >= NPROTO)
-               return NULL;
+       trav->class = MTTG_TRAV_INIT;
+       for (j = 0; j < *pos; ++j)
+               if (xt_mttg_seq_next(seq, NULL, NULL, is_target) == NULL)
+                       return NULL;
+       return trav;
+}
 
-       list = type2list(af, type);
-       if (!list)
-               return NULL;
+static void xt_mttg_seq_stop(struct seq_file *seq, void *v)
+{
+       struct nf_mttg_trav *trav = seq->private;
 
-       if (mutex_lock_interruptible(&xt[af].mutex) != 0)
-               return NULL;
-       
-       return xt_get_idx(list, seq, *pos);
+       switch (trav->class) {
+       case MTTG_TRAV_NFP_UNSPEC:
+               mutex_unlock(&xt[NFPROTO_UNSPEC].mutex);
+               break;
+       case MTTG_TRAV_NFP_SPEC:
+               mutex_unlock(&xt[trav->nfproto].mutex);
+               break;
+       }
 }
 
-static void *xt_tgt_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+static void *xt_match_seq_start(struct seq_file *seq, loff_t *pos)
 {
-       struct proc_dir_entry *pde = seq->private;
-       u_int16_t af = (unsigned long)pde->data & 0xffff;
-       u_int16_t type = (unsigned long)pde->data >> 16;
-       struct list_head *list;
+       return xt_mttg_seq_start(seq, pos, false);
+}
 
-       if (af >= NPROTO)
-               return NULL;
-       
-       list = type2list(af, type);
-       if (!list)
-               return NULL;
+static void *xt_match_seq_next(struct seq_file *seq, void *v, loff_t *ppos)
+{
+       return xt_mttg_seq_next(seq, v, ppos, false);
+}
 
-       (*pos)++;
-       return xt_get_idx(list, seq, *pos);
+static int xt_match_seq_show(struct seq_file *seq, void *v)
+{
+       const struct nf_mttg_trav *trav = seq->private;
+       const struct xt_match *match;
+
+       switch (trav->class) {
+       case MTTG_TRAV_NFP_UNSPEC:
+       case MTTG_TRAV_NFP_SPEC:
+               if (trav->curr == trav->head)
+                       return 0;
+               match = list_entry(trav->curr, struct xt_match, list);
+               return (*match->name == '\0') ? 0 :
+                      seq_printf(seq, "%s\n", match->name);
+       }
+       return 0;
 }
 
-static void xt_tgt_seq_stop(struct seq_file *seq, void *v)
+static const struct seq_operations xt_match_seq_ops = {
+       .start  = xt_match_seq_start,
+       .next   = xt_match_seq_next,
+       .stop   = xt_mttg_seq_stop,
+       .show   = xt_match_seq_show,
+};
+
+static int xt_match_open(struct inode *inode, struct file *file)
 {
-       struct proc_dir_entry *pde = seq->private;
-       u_int16_t af = (unsigned long)pde->data & 0xffff;
+       struct seq_file *seq;
+       struct nf_mttg_trav *trav;
+       int ret;
 
-       mutex_unlock(&xt[af].mutex);
+       trav = kmalloc(sizeof(*trav), GFP_KERNEL);
+       if (trav == NULL)
+               return -ENOMEM;
+
+       ret = seq_open(file, &xt_match_seq_ops);
+       if (ret < 0) {
+               kfree(trav);
+               return ret;
+       }
+
+       seq = file->private_data;
+       seq->private = trav;
+       trav->nfproto = (unsigned long)PDE(inode)->data;
+       return 0;
 }
 
-static int xt_name_seq_show(struct seq_file *seq, void *v)
+static const struct file_operations xt_match_ops = {
+       .owner   = THIS_MODULE,
+       .open    = xt_match_open,
+       .read    = seq_read,
+       .llseek  = seq_lseek,
+       .release = seq_release_private,
+};
+
+static void *xt_target_seq_start(struct seq_file *seq, loff_t *pos)
 {
-       char *name = (char *)v + sizeof(struct list_head);
+       return xt_mttg_seq_start(seq, pos, true);
+}
 
-       if (strlen(name))
-               return seq_printf(seq, "%s\n", name);
-       else
-               return 0;
+static void *xt_target_seq_next(struct seq_file *seq, void *v, loff_t *ppos)
+{
+       return xt_mttg_seq_next(seq, v, ppos, true);
 }
 
-static struct seq_operations xt_tgt_seq_ops = {
-       .start  = xt_tgt_seq_start,
-       .next   = xt_tgt_seq_next,
-       .stop   = xt_tgt_seq_stop,
-       .show   = xt_name_seq_show,
+static int xt_target_seq_show(struct seq_file *seq, void *v)
+{
+       const struct nf_mttg_trav *trav = seq->private;
+       const struct xt_target *target;
+
+       switch (trav->class) {
+       case MTTG_TRAV_NFP_UNSPEC:
+       case MTTG_TRAV_NFP_SPEC:
+               if (trav->curr == trav->head)
+                       return 0;
+               target = list_entry(trav->curr, struct xt_target, list);
+               return (*target->name == '\0') ? 0 :
+                      seq_printf(seq, "%s\n", target->name);
+       }
+       return 0;
+}
+
+static const struct seq_operations xt_target_seq_ops = {
+       .start  = xt_target_seq_start,
+       .next   = xt_target_seq_next,
+       .stop   = xt_mttg_seq_stop,
+       .show   = xt_target_seq_show,
 };
 
-static int xt_tgt_open(struct inode *inode, struct file *file)
+static int xt_target_open(struct inode *inode, struct file *file)
 {
+       struct seq_file *seq;
+       struct nf_mttg_trav *trav;
        int ret;
 
-       ret = seq_open(file, &xt_tgt_seq_ops);
-       if (!ret) {
-               struct seq_file *seq = file->private_data;
-               struct proc_dir_entry *pde = PDE(inode);
+       trav = kmalloc(sizeof(*trav), GFP_KERNEL);
+       if (trav == NULL)
+               return -ENOMEM;
 
-               seq->private = pde;
+       ret = seq_open(file, &xt_target_seq_ops);
+       if (ret < 0) {
+               kfree(trav);
+               return ret;
        }
 
-       return ret;
+       seq = file->private_data;
+       seq->private = trav;
+       trav->nfproto = (unsigned long)PDE(inode)->data;
+       return 0;
 }
 
-static struct file_operations xt_file_ops = {
+static const struct file_operations xt_target_ops = {
        .owner   = THIS_MODULE,
-       .open    = xt_tgt_open,
+       .open    = xt_target_open,
        .read    = seq_read,
        .llseek  = seq_lseek,
-       .release = seq_release,
+       .release = seq_release_private,
 };
 
 #define FORMAT_TABLES  "_tables_names"
@@ -587,99 +1097,178 @@ static struct file_operations xt_file_ops = {
 
 #endif /* CONFIG_PROC_FS */
 
-int xt_proto_init(int af)
+/**
+ * xt_hook_link - set up hooks for a new table
+ * @table:     table with metadata needed to set up hooks
+ * @fn:                Hook function
+ *
+ * This function will take care of creating and registering the necessary
+ * Netfilter hooks for XT tables.
+ */
+struct nf_hook_ops *xt_hook_link(const struct xt_table *table, nf_hookfn *fn)
+{
+       unsigned int hook_mask = table->valid_hooks;
+       uint8_t i, num_hooks = hweight32(hook_mask);
+       uint8_t hooknum;
+       struct nf_hook_ops *ops;
+       int ret;
+
+       ops = kmalloc(sizeof(*ops) * num_hooks, GFP_KERNEL);
+       if (ops == NULL)
+               return ERR_PTR(-ENOMEM);
+
+       for (i = 0, hooknum = 0; i < num_hooks && hook_mask != 0;
+            hook_mask >>= 1, ++hooknum) {
+               if (!(hook_mask & 1))
+                       continue;
+               ops[i].hook     = fn;
+               ops[i].owner    = table->me;
+               ops[i].pf       = table->af;
+               ops[i].hooknum  = hooknum;
+               ops[i].priority = table->priority;
+               ++i;
+       }
+
+       ret = nf_register_hooks(ops, num_hooks);
+       if (ret < 0) {
+               kfree(ops);
+               return ERR_PTR(ret);
+       }
+
+       return ops;
+}
+EXPORT_SYMBOL_GPL(xt_hook_link);
+
+/**
+ * xt_hook_unlink - remove hooks for a table
+ * @ops:       nf_hook_ops array as returned by nf_hook_link
+ * @hook_mask: the very same mask that was passed to nf_hook_link
+ */
+void xt_hook_unlink(const struct xt_table *table, struct nf_hook_ops *ops)
+{
+       nf_unregister_hooks(ops, hweight32(table->valid_hooks));
+       kfree(ops);
+}
+EXPORT_SYMBOL_GPL(xt_hook_unlink);
+
+int xt_proto_init(struct net *net, u_int8_t af)
 {
 #ifdef CONFIG_PROC_FS
        char buf[XT_FUNCTION_MAXNAMELEN];
        struct proc_dir_entry *proc;
 #endif
 
-       if (af >= NPROTO)
+       if (af >= ARRAY_SIZE(xt_prefix))
                return -EINVAL;
 
 
 #ifdef CONFIG_PROC_FS
-       strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
+       strlcpy(buf, xt_prefix[af], sizeof(buf));
        strlcat(buf, FORMAT_TABLES, sizeof(buf));
-       proc = proc_net_fops_create(buf, 0440, &xt_file_ops);
+       proc = proc_create_data(buf, 0440, net->proc_net, &xt_table_ops,
+                               (void *)(unsigned long)af);
        if (!proc)
                goto out;
-       proc->data = (void *) ((unsigned long) af | (TABLE << 16));
 
-
-       strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
+       strlcpy(buf, xt_prefix[af], sizeof(buf));
        strlcat(buf, FORMAT_MATCHES, sizeof(buf));
-       proc = proc_net_fops_create(buf, 0440, &xt_file_ops);
+       proc = proc_create_data(buf, 0440, net->proc_net, &xt_match_ops,
+                               (void *)(unsigned long)af);
        if (!proc)
                goto out_remove_tables;
-       proc->data = (void *) ((unsigned long) af | (MATCH << 16));
 
-       strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
+       strlcpy(buf, xt_prefix[af], sizeof(buf));
        strlcat(buf, FORMAT_TARGETS, sizeof(buf));
-       proc = proc_net_fops_create(buf, 0440, &xt_file_ops);
+       proc = proc_create_data(buf, 0440, net->proc_net, &xt_target_ops,
+                               (void *)(unsigned long)af);
        if (!proc)
                goto out_remove_matches;
-       proc->data = (void *) ((unsigned long) af | (TARGET << 16));
 #endif
 
        return 0;
 
 #ifdef CONFIG_PROC_FS
 out_remove_matches:
-       strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
+       strlcpy(buf, xt_prefix[af], sizeof(buf));
        strlcat(buf, FORMAT_MATCHES, sizeof(buf));
-       proc_net_remove(buf);
+       proc_net_remove(net, buf);
 
 out_remove_tables:
-       strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
+       strlcpy(buf, xt_prefix[af], sizeof(buf));
        strlcat(buf, FORMAT_TABLES, sizeof(buf));
-       proc_net_remove(buf);
+       proc_net_remove(net, buf);
 out:
        return -1;
 #endif
 }
 EXPORT_SYMBOL_GPL(xt_proto_init);
 
-void xt_proto_fini(int af)
+void xt_proto_fini(struct net *net, u_int8_t af)
 {
 #ifdef CONFIG_PROC_FS
        char buf[XT_FUNCTION_MAXNAMELEN];
 
-       strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
+       strlcpy(buf, xt_prefix[af], sizeof(buf));
        strlcat(buf, FORMAT_TABLES, sizeof(buf));
-       proc_net_remove(buf);
+       proc_net_remove(net, buf);
 
-       strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
+       strlcpy(buf, xt_prefix[af], sizeof(buf));
        strlcat(buf, FORMAT_TARGETS, sizeof(buf));
-       proc_net_remove(buf);
+       proc_net_remove(net, buf);
 
-       strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
+       strlcpy(buf, xt_prefix[af], sizeof(buf));
        strlcat(buf, FORMAT_MATCHES, sizeof(buf));
-       proc_net_remove(buf);
+       proc_net_remove(net, buf);
 #endif /*CONFIG_PROC_FS*/
 }
 EXPORT_SYMBOL_GPL(xt_proto_fini);
 
+static int __net_init xt_net_init(struct net *net)
+{
+       int i;
+
+       for (i = 0; i < NFPROTO_NUMPROTO; i++)
+               INIT_LIST_HEAD(&net->xt.tables[i]);
+       return 0;
+}
+
+static struct pernet_operations xt_net_ops = {
+       .init = xt_net_init,
+};
 
 static int __init xt_init(void)
 {
-       int i;
+       unsigned int i;
+       int rv;
 
-       xt = kmalloc(sizeof(struct xt_af) * NPROTO, GFP_KERNEL);
+       for_each_possible_cpu(i) {
+               struct xt_info_lock *lock = &per_cpu(xt_info_locks, i);
+               spin_lock_init(&lock->lock);
+               lock->readers = 0;
+       }
+
+       xt = kmalloc(sizeof(struct xt_af) * NFPROTO_NUMPROTO, GFP_KERNEL);
        if (!xt)
                return -ENOMEM;
 
-       for (i = 0; i < NPROTO; i++) {
+       for (i = 0; i < NFPROTO_NUMPROTO; i++) {
                mutex_init(&xt[i].mutex);
+#ifdef CONFIG_COMPAT
+               mutex_init(&xt[i].compat_mutex);
+               xt[i].compat_offsets = NULL;
+#endif
                INIT_LIST_HEAD(&xt[i].target);
                INIT_LIST_HEAD(&xt[i].match);
-               INIT_LIST_HEAD(&xt[i].tables);
        }
-       return 0;
+       rv = register_pernet_subsys(&xt_net_ops);
+       if (rv < 0)
+               kfree(xt);
+       return rv;
 }
 
 static void __exit xt_fini(void)
 {
+       unregister_pernet_subsys(&xt_net_ops);
        kfree(xt);
 }