[EBTABLES]: Split ebt_replace into user and kernel variants, annotate.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/netfilter_bridge/ebtables.h

@@ -38,6 +38,23 @@ struct ebt_counter
 };
 
 struct ebt_replace
+{
+	char name[EBT_TABLE_MAXNAMELEN];
+	unsigned int valid_hooks;
+	/* nr of rules in the table */
+	unsigned int nentries;
+	/* total size of the entries */
+	unsigned int entries_size;
+	/* start of the chains */
+	struct ebt_entries __user *hook_entry[NF_BR_NUMHOOKS];
+	/* nr of counters userspace expects back */
+	unsigned int num_counters;
+	/* where the kernel will put the old counters */
+	struct ebt_counter __user *counters;
+	char __user *entries;
+};
+
+struct ebt_replace_kernel
 {
 	char name[EBT_TABLE_MAXNAMELEN];
 	unsigned int valid_hooks;
@@ -255,7 +272,7 @@ struct ebt_table
 {
 	struct list_head list;
 	char name[EBT_TABLE_MAXNAMELEN];
-	struct ebt_replace *table;
+	struct ebt_replace_kernel *table;
 	unsigned int valid_hooks;
 	rwlock_t lock;
 	/* e.g. could be the table explicitly only allows certain

net/bridge/netfilter/ebtable_broute.c

@@ -23,7 +23,7 @@ static struct ebt_entries initial_chain = {
 	.policy		= EBT_ACCEPT,
 };
 
-static struct ebt_replace initial_table =
+static struct ebt_replace_kernel initial_table =
 {
 	.name		= "broute",
 	.valid_hooks	= 1 << NF_BR_BROUTING,

net/bridge/netfilter/ebtable_filter.c

@@ -30,7 +30,7 @@ static struct ebt_entries initial_chains[] =
 	},
 };
 
-static struct ebt_replace initial_table =
+static struct ebt_replace_kernel initial_table =
 {
 	.name		= "filter",
 	.valid_hooks	= FILTER_VALID_HOOKS,

net/bridge/netfilter/ebtable_nat.c

@@ -30,7 +30,7 @@ static struct ebt_entries initial_chains[] =
 	}
 };
 
-static struct ebt_replace initial_table =
+static struct ebt_replace_kernel initial_table =
 {
 	.name		= "nat",
 	.valid_hooks	= NAT_VALID_HOOKS,

net/bridge/netfilter/ebtables.c

@@ -417,7 +417,8 @@ static int ebt_verify_pointers(struct ebt_replace *repl,
 		for (i = 0; i < NF_BR_NUMHOOKS; i++) {
 			if ((valid_hooks & (1 << i)) == 0)
 				continue;
-			if ((char *)repl->hook_entry[i] == repl->entries + offset)
+			if ((char __user *)repl->hook_entry[i] ==
+			     repl->entries + offset)
 				break;
 		}
 
@@ -1156,7 +1157,7 @@ int ebt_register_table(struct ebt_table *table)
 {
 	struct ebt_table_info *newinfo;
 	struct ebt_table *t;
-	struct ebt_replace *repl;
+	struct ebt_replace_kernel *repl;
 	int ret, i, countersize;
 	void *p;
 
@@ -1320,33 +1321,33 @@ static int update_counters(void __user *user, unsigned int len)
 }
 
 static inline int ebt_make_matchname(struct ebt_entry_match *m,
-   char *base, char *ubase)
+   char *base, char __user *ubase)
 {
-	char *hlp = ubase - base + (char *)m;
+	char __user *hlp = ubase + ((char *)m - base);
 	if (copy_to_user(hlp, m->u.match->name, EBT_FUNCTION_MAXNAMELEN))
 		return -EFAULT;
 	return 0;
 }
 
 static inline int ebt_make_watchername(struct ebt_entry_watcher *w,
-   char *base, char *ubase)
+   char *base, char __user *ubase)
 {
-	char *hlp = ubase - base + (char *)w;
+	char __user *hlp = ubase + ((char *)w - base);
 	if (copy_to_user(hlp , w->u.watcher->name, EBT_FUNCTION_MAXNAMELEN))
 		return -EFAULT;
 	return 0;
 }
 
-static inline int ebt_make_names(struct ebt_entry *e, char *base, char *ubase)
+static inline int ebt_make_names(struct ebt_entry *e, char *base, char __user *ubase)
 {
 	int ret;
-	char *hlp;
+	char __user *hlp;
 	struct ebt_entry_target *t;
 
 	if (e->bitmask == 0)
 		return 0;
 
-	hlp = ubase - base + (char *)e + e->target_offset;
+	hlp = ubase + (((char *)e + e->target_offset) - base);
 	t = (struct ebt_entry_target *)(((char *)e) + e->target_offset);
 	
 	ret = EBT_MATCH_ITERATE(e, ebt_make_matchname, base, ubase);