X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=blobdiff_plain;f=include%2Flinux%2Fnetfilter%2Fx_tables.h;h=3caf5e151102600e18051140ca949ef115b6ba16;hp=bcd40ec83257b5bdcf4aa74afb3d498304389ef0;hb=f54e9367f8499a9bf6b2afbc0dce63e1d53c525a;hpb=f7108a20dee44e5bb037f9e48f6a207b42e6ae1c

diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h
index bcd40ec..3caf5e1 100644
--- a/include/linux/netfilter/x_tables.h
+++ b/include/linux/netfilter/x_tables.h
@@ -1,54 +1,54 @@
 #ifndef _X_TABLES_H
 #define _X_TABLES_H
 
+#include <linux/types.h>
+
 #define XT_FUNCTION_MAXNAMELEN 30
 #define XT_TABLE_MAXNAMELEN 32
 
-struct xt_entry_match
-{
+struct xt_entry_match {
 	union {
 		struct {
-			u_int16_t match_size;
+			__u16 match_size;
 
 			/* Used by userspace */
 			char name[XT_FUNCTION_MAXNAMELEN-1];
 
-			u_int8_t revision;
+			__u8 revision;
 		} user;
 		struct {
-			u_int16_t match_size;
+			__u16 match_size;
 
 			/* Used inside the kernel */
 			struct xt_match *match;
 		} kernel;
 
 		/* Total length */
-		u_int16_t match_size;
+		__u16 match_size;
 	} u;
 
 	unsigned char data[0];
 };
 
-struct xt_entry_target
-{
+struct xt_entry_target {
 	union {
 		struct {
-			u_int16_t target_size;
+			__u16 target_size;
 
 			/* Used by userspace */
 			char name[XT_FUNCTION_MAXNAMELEN-1];
 
-			u_int8_t revision;
+			__u8 revision;
 		} user;
 		struct {
-			u_int16_t target_size;
+			__u16 target_size;
 
 			/* Used inside the kernel */
 			struct xt_target *target;
 		} kernel;
 
 		/* Total length */
-		u_int16_t target_size;
+		__u16 target_size;
 	} u;
 
 	unsigned char data[0];
@@ -62,19 +62,17 @@ struct xt_entry_target
 	},								       \
 }
 
-struct xt_standard_target
-{
+struct xt_standard_target {
 	struct xt_entry_target target;
 	int verdict;
 };
 
 /* The argument to IPT_SO_GET_REVISION_*.  Returns highest revision
  * kernel supports, if >= revision. */
-struct xt_get_revision
-{
+struct xt_get_revision {
 	char name[XT_FUNCTION_MAXNAMELEN-1];
 
-	u_int8_t revision;
+	__u8 revision;
 };
 
 /* CONTINUE verdict for targets */
@@ -88,12 +86,11 @@ struct xt_get_revision
  * ip6t_entry and arpt_entry.  This sucks, and it is a hack.  It will be my
  * personal pleasure to remove it -HW
  */
-struct _xt_align
-{
-	u_int8_t u8;
-	u_int16_t u16;
-	u_int32_t u32;
-	u_int64_t u64;
+struct _xt_align {
+	__u8 u8;
+	__u16 u16;
+	__u32 u32;
+	__u64 u64;
 };
 
 #define XT_ALIGN(s) (((s) + (__alignof__(struct _xt_align)-1)) 	\
@@ -107,14 +104,12 @@ struct _xt_align
 #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)
 
-struct xt_counters
-{
-	u_int64_t pcnt, bcnt;			/* Packet and byte counters */
+struct xt_counters {
+	__u64 pcnt, bcnt;			/* Packet and byte counters */
 };
 
 /* The argument to IPT_SO_ADD_COUNTERS. */
-struct xt_counters_info
-{
+struct xt_counters_info {
 	/* Which table. */
 	char name[XT_TABLE_MAXNAMELEN];
 
@@ -182,6 +177,9 @@ struct xt_counters_info
  * @matchinfo:	per-match data
  * @fragoff:	packet is a fragment, this is the data offset
  * @thoff:	position of transport header relative to skb->data
+ * @hook:	hook number given packet came from
+ * @family:	Actual NFPROTO_* through which the function is invoked
+ * 		(helpful when match->family == NFPROTO_UNSPEC)
  * @hotdrop:	drop packet if we had inspection problems
  */
 struct xt_match_param {
@@ -190,14 +188,87 @@ struct xt_match_param {
 	const void *matchinfo;
 	int fragoff;
 	unsigned int thoff;
+	unsigned int hooknum;
+	u_int8_t family;
 	bool *hotdrop;
 };
 
-struct xt_match
-{
+/**
+ * struct xt_mtchk_param - parameters for match extensions'
+ * checkentry functions
+ *
+ * @table:	table the rule is tried to be inserted into
+ * @entryinfo:	the family-specific rule data
+ * 		(struct ipt_ip, ip6t_ip, ebt_entry)
+ * @match:	struct xt_match through which this function was invoked
+ * @matchinfo:	per-match data
+ * @hook_mask:	via which hooks the new rule is reachable
+ */
+struct xt_mtchk_param {
+	struct net *net;
+	const char *table;
+	const void *entryinfo;
+	const struct xt_match *match;
+	void *matchinfo;
+	unsigned int hook_mask;
+	u_int8_t family;
+};
+
+/* Match destructor parameters */
+struct xt_mtdtor_param {
+	struct net *net;
+	const struct xt_match *match;
+	void *matchinfo;
+	u_int8_t family;
+};
+
+/**
+ * struct xt_target_param - parameters for target extensions' target functions
+ *
+ * @hooknum:	hook through which this target was invoked
+ * @target:	struct xt_target through which this function was invoked
+ * @targinfo:	per-target data
+ *
+ * Other fields see above.
+ */
+struct xt_target_param {
+	const struct net_device *in, *out;
+	const struct xt_target *target;
+	const void *targinfo;
+	unsigned int hooknum;
+	u_int8_t family;
+};
+
+/**
+ * struct xt_tgchk_param - parameters for target extensions'
+ * checkentry functions
+ *
+ * @entryinfo:	the family-specific rule data
+ * 		(struct ipt_entry, ip6t_entry, arpt_entry, ebt_entry)
+ *
+ * Other fields see above.
+ */
+struct xt_tgchk_param {
+	const char *table;
+	const void *entryinfo;
+	const struct xt_target *target;
+	void *targinfo;
+	unsigned int hook_mask;
+	u_int8_t family;
+};
+
+/* Target destructor parameters */
+struct xt_tgdtor_param {
+	const struct xt_target *target;
+	void *targinfo;
+	u_int8_t family;
+};
+
+struct xt_match {
 	struct list_head list;
 
 	const char name[XT_FUNCTION_MAXNAMELEN-1];
+	u_int8_t revision;
 
 	/* Return true or false: return FALSE and set *hotdrop = 1 to
            force immediate packet drop. */
@@ -208,15 +279,10 @@ struct xt_match
 		      const struct xt_match_param *);
 
 	/* Called when user tries to insert an entry of this type. */
-	/* Should return true or false. */
-	bool (*checkentry)(const char *tablename,
-			   const void *ip,
-			   const struct xt_match *match,
-			   void *matchinfo,
-			   unsigned int hook_mask);
+	bool (*checkentry)(const struct xt_mtchk_param *);
 
 	/* Called when entry of this type deleted. */
-	void (*destroy)(const struct xt_match *match, void *matchinfo);
+	void (*destroy)(const struct xt_mtdtor_param *);
 
 	/* Called when userspace align differs from kernel space one */
 	void (*compat_from_user)(void *dst, void *src);
@@ -235,12 +301,10 @@ struct xt_match
 	unsigned short proto;
 
 	unsigned short family;
-	u_int8_t revision;
 };
 
 /* Registration hooks for targets. */
-struct xt_target
-{
+struct xt_target {
 	struct list_head list;
 
 	const char name[XT_FUNCTION_MAXNAMELEN-1];
@@ -249,24 +313,16 @@ struct xt_target
 	   must now handle non-linear skbs, using skb_copy_bits and
 	   skb_ip_make_writable. */
 	unsigned int (*target)(struct sk_buff *skb,
-			       const struct net_device *in,
-			       const struct net_device *out,
-			       unsigned int hooknum,
-			       const struct xt_target *target,
-			       const void *targinfo);
+			       const struct xt_target_param *);
 
 	/* Called when user tries to insert an entry of this type:
            hook_mask is a bitmask of hooks from which it can be
            called. */
 	/* Should return true or false. */
-	bool (*checkentry)(const char *tablename,
-			   const void *entry,
-			   const struct xt_target *target,
-			   void *targinfo,
-			   unsigned int hook_mask);
+	bool (*checkentry)(const struct xt_tgchk_param *);
 
 	/* Called when entry of this type deleted. */
-	void (*destroy)(const struct xt_target *target, void *targinfo);
+	void (*destroy)(const struct xt_tgdtor_param *);
 
 	/* Called when userspace align differs from kernel space one */
 	void (*compat_from_user)(void *dst, void *src);
@@ -286,34 +342,28 @@ struct xt_target
 };
 
 /* Furniture shopping... */
-struct xt_table
-{
+struct xt_table {
 	struct list_head list;
 
-	/* A unique name... */
-	const char name[XT_TABLE_MAXNAMELEN];
-
 	/* What hooks you will enter on */
 	unsigned int valid_hooks;
 
-	/* Lock for the curtain */
-	rwlock_t lock;
-
 	/* Man behind the curtain... */
-	//struct ip6t_table_info *private;
-	void *private;
+	struct xt_table_info *private;
 
 	/* Set this to THIS_MODULE if you are a module, otherwise NULL */
 	struct module *me;
 
 	u_int8_t af;		/* address/protocol family */
+
+	/* A unique name... */
+	const char name[XT_TABLE_MAXNAMELEN];
 };
 
 #include <linux/netfilter_ipv4.h>
 
 /* The table itself */
-struct xt_table_info
-{
+struct xt_table_info {
 	/* Size per table */
 	unsigned int size;
 	/* Number of entries: FIXME. --RR */
@@ -327,7 +377,7 @@ struct xt_table_info
 
 	/* ipt_entry tables: one per CPU */
 	/* Note : this field MUST be the last one, see XT_TABLE_INFO_SZ */
-	char *entries[1];
+	void *entries[1];
 };
 
 #define XT_TABLE_INFO_SZ (offsetof(struct xt_table_info, entries) \
@@ -342,17 +392,13 @@ extern void xt_unregister_match(struct xt_match *target);
 extern int xt_register_matches(struct xt_match *match, unsigned int n);
 extern void xt_unregister_matches(struct xt_match *match, unsigned int n);
 
-extern int xt_check_match(const struct xt_match *match, unsigned short family,
-			  unsigned int size, const char *table, unsigned int hook,
-			  unsigned short proto, int inv_proto,
-			  const void *entry, void *matchinfo);
-extern int xt_check_target(const struct xt_target *target, unsigned short family,
-			   unsigned int size, const char *table, unsigned int hook,
-			   unsigned short proto, int inv_proto,
-			   const void *entry, void *targinfo);
+extern int xt_check_match(struct xt_mtchk_param *,
+			  unsigned int size, u_int8_t proto, bool inv_proto);
+extern int xt_check_target(struct xt_tgchk_param *,
+			   unsigned int size, u_int8_t proto, bool inv_proto);
 
 extern struct xt_table *xt_register_table(struct net *net,
-					  struct xt_table *table,
+					  const struct xt_table *table,
 					  struct xt_table_info *bootstrap,
 					  struct xt_table_info *newinfo);
 extern void *xt_unregister_table(struct xt_table *table);
@@ -379,11 +425,101 @@ extern void xt_proto_fini(struct net *net, u_int8_t af);
 extern struct xt_table_info *xt_alloc_table_info(unsigned int size);
 extern void xt_free_table_info(struct xt_table_info *info);
 
+/*
+ * Per-CPU spinlock associated with per-cpu table entries, and
+ * with a counter for the "reading" side that allows a recursive
+ * reader to avoid taking the lock and deadlocking.
+ *
+ * "reading" is used by ip/arp/ip6 tables rule processing which runs per-cpu.
+ * It needs to ensure that the rules are not being changed while the packet
+ * is being processed. In some cases, the read lock will be acquired
+ * twice on the same CPU; this is okay because of the count.
+ *
+ * "writing" is used when reading counters.
+ *  During replace any readers that are using the old tables have to complete
+ *  before freeing the old table. This is handled by the write locking
+ *  necessary for reading the counters.
+ */
+struct xt_info_lock {
+	spinlock_t lock;
+	unsigned char readers;
+};
+DECLARE_PER_CPU(struct xt_info_lock, xt_info_locks);
+
+/*
+ * Note: we need to ensure that preemption is disabled before acquiring
+ * the per-cpu-variable, so we do it as a two step process rather than
+ * using "spin_lock_bh()".
+ *
+ * We _also_ need to disable bottom half processing before updating our
+ * nesting count, to make sure that the only kind of re-entrancy is this
+ * code being called by itself: since the count+lock is not an atomic
+ * operation, we can allow no races.
+ *
+ * _Only_ that special combination of being per-cpu and never getting
+ * re-entered asynchronously means that the count is safe.
+ */
+static inline void xt_info_rdlock_bh(void)
+{
+	struct xt_info_lock *lock;
+
+	local_bh_disable();
+	lock = &__get_cpu_var(xt_info_locks);
+	if (likely(!lock->readers++))
+		spin_lock(&lock->lock);
+}
+
+static inline void xt_info_rdunlock_bh(void)
+{
+	struct xt_info_lock *lock = &__get_cpu_var(xt_info_locks);
+
+	if (likely(!--lock->readers))
+		spin_unlock(&lock->lock);
+	local_bh_enable();
+}
+
+/*
+ * The "writer" side needs to get exclusive access to the lock,
+ * regardless of readers.  This must be called with bottom half
+ * processing (and thus also preemption) disabled.
+ */
+static inline void xt_info_wrlock(unsigned int cpu)
+{
+	spin_lock(&per_cpu(xt_info_locks, cpu).lock);
+}
+
+static inline void xt_info_wrunlock(unsigned int cpu)
+{
+	spin_unlock(&per_cpu(xt_info_locks, cpu).lock);
+}
+
+/*
+ * This helper is performance critical and must be inlined
+ */
+static inline unsigned long ifname_compare_aligned(const char *_a,
+						   const char *_b,
+						   const char *_mask)
+{
+	const unsigned long *a = (const unsigned long *)_a;
+	const unsigned long *b = (const unsigned long *)_b;
+	const unsigned long *mask = (const unsigned long *)_mask;
+	unsigned long ret;
+
+	ret = (a[0] ^ b[0]) & mask[0];
+	if (IFNAMSIZ > sizeof(unsigned long))
+		ret |= (a[1] ^ b[1]) & mask[1];
+	if (IFNAMSIZ > 2 * sizeof(unsigned long))
+		ret |= (a[2] ^ b[2]) & mask[2];
+	if (IFNAMSIZ > 3 * sizeof(unsigned long))
+		ret |= (a[3] ^ b[3]) & mask[3];
+	BUILD_BUG_ON(IFNAMSIZ > 4 * sizeof(unsigned long));
+	return ret;
+}
+
 #ifdef CONFIG_COMPAT
 #include <net/compat.h>
 
-struct compat_xt_entry_match
-{
+struct compat_xt_entry_match {
 	union {
 		struct {
 			u_int16_t match_size;
@@ -399,8 +535,7 @@ struct compat_xt_entry_match
 	unsigned char data[0];
 };
 
-struct compat_xt_entry_target
-{
+struct compat_xt_entry_target {
 	union {
 		struct {
 			u_int16_t target_size;
@@ -420,8 +555,7 @@ struct compat_xt_entry_target
  * need to change whole approach in order to calculate align as function of
  * current task alignment */
 
-struct compat_xt_counters
-{
+struct compat_xt_counters {
 #if defined(CONFIG_X86_64) || defined(CONFIG_IA64)
 	u_int32_t cnt[4];
 #else
@@ -429,8 +563,7 @@ struct compat_xt_counters
 #endif
 };
 
-struct compat_xt_counters_info
-{
+struct compat_xt_counters_info {
 	char name[XT_TABLE_MAXNAMELEN];
 	compat_uint_t num_counters;
 	struct compat_xt_counters counters[0];