patch-2.3.99-pre2 linux/include/linux/netfilter_ipv4/ip_tables.h

• Lines: 421
• Date: Sat Mar 18 16:51:35 2000
• Orig file: v2.3.99-pre1/linux/include/linux/netfilter_ipv4/ip_tables.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.99-pre1/linux/include/linux/netfilter_ipv4/ip_tables.h linux/include/linux/netfilter_ipv4/ip_tables.h
@@ -0,0 +1,420 @@
+/*
+ * 25-Jul-1998 Major changes to allow for ip chain table
+ *
+ * 3-Jan-2000 Named tables to allow packet selection for different uses.
+ */
+
+/*
+ * 	Format of an IP firewall descriptor
+ *
+ * 	src, dst, src_mask, dst_mask are always stored in network byte order.
+ * 	flags are stored in host byte order (of course).
+ * 	Port numbers are stored in HOST byte order.
+ */
+
+#ifndef _IPTABLES_H
+#define _IPTABLES_H
+
+#ifdef __KERNEL__
+#include <linux/if.h>
+#include <linux/types.h>
+#include <linux/in.h>
+#include <linux/ip.h>
+#include <linux/skbuff.h>
+#endif
+#include <linux/netfilter_ipv4.h>
+
+#define IPT_FUNCTION_MAXNAMELEN 32
+#define IPT_TABLE_MAXNAMELEN 32
+
+/* Yes, Virginia, you have to zero the padding. */
+struct ipt_ip {
+	/* Source and destination IP addr */
+	struct in_addr src, dst;
+	/* Mask for src and dest IP addr */
+	struct in_addr smsk, dmsk;
+	char iniface[IFNAMSIZ], outiface[IFNAMSIZ];
+	unsigned char iniface_mask[IFNAMSIZ], outiface_mask[IFNAMSIZ];
+
+	/* Protocol, 0 = ANY */
+	u_int16_t proto;
+
+	/* Flags word */
+	u_int8_t flags;
+	/* Inverse flags */
+	u_int8_t invflags;
+};
+
+struct ipt_entry_match
+{
+	/* Total length */
+	u_int16_t match_size;
+	union {
+		/* Used by userspace */
+		char name[IPT_FUNCTION_MAXNAMELEN];
+		/* Used inside the kernel */
+		struct ipt_match *match;
+	} u;
+
+	unsigned char data[0];
+};
+
+struct ipt_entry_target
+{
+	/* Total length */
+	u_int16_t target_size;
+	union {
+		/* Used by userspace */
+		char name[IPT_FUNCTION_MAXNAMELEN];
+		/* Used inside the kernel */
+		struct ipt_target *target;
+	} u;
+
+	unsigned char data[0];
+};
+
+struct ipt_standard_target
+{
+	struct ipt_entry_target target;
+	int verdict;
+};
+
+struct ipt_counters
+{
+	u_int64_t pcnt, bcnt;			/* Packet and byte counters */
+};
+
+/* Values for "flag" field in struct ipt_ip (general ip structure). */
+#define IPT_F_FRAG		0x01	/* Set if rule is a fragment rule */
+#define IPT_F_MASK		0x01	/* All possible flag bits mask. */
+
+/* Values for "inv" field in struct ipt_ip. */
+#define IPT_INV_VIA_IN		0x01	/* Invert the sense of IN IFACE. */
+#define IPT_INV_VIA_OUT		0x02	/* Invert the sense of OUT IFACE */
+#define IPT_INV_TOS		0x04	/* Invert the sense of TOS. */
+#define IPT_INV_SRCIP		0x08	/* Invert the sense of SRC IP. */
+#define IPT_INV_DSTIP		0x10	/* Invert the sense of DST OP. */
+#define IPT_INV_FRAG		0x20	/* Invert the sense of FRAG. */
+#define IPT_INV_PROTO		0x40	/* Invert the sense of PROTO. */
+#define IPT_INV_MASK		0x7F	/* All possible flag bits mask. */
+
+/* This structure defines each of the firewall rules.  Consists of 3
+   parts which are 1) general IP header stuff 2) match specific
+   stuff 3) the target to perform if the rule matches */
+struct ipt_entry
+{
+	struct ipt_ip ip;
+
+	/* Mark with fields that we care about. */
+	unsigned int nfcache;
+
+	/* Size of ipt_entry + matches */
+	u_int16_t target_offset;
+	/* Size of ipt_entry + matches + target */
+	u_int16_t next_offset;
+
+	/* Back pointer */
+	unsigned int comefrom;
+
+	/* Packet and byte counters. */
+	struct ipt_counters counters;
+
+	/* The matches (if any), then the target. */
+	unsigned char elems[0];
+};
+
+/*
+ * New IP firewall options for [gs]etsockopt at the RAW IP level.
+ * Unlike BSD Linux inherits IP options so you don't have to use a raw
+ * socket for this. Instead we check rights in the calls. */
+#define IPT_BASE_CTL		64	/* base for firewall socket options */
+
+#define IPT_SO_SET_REPLACE	(IPT_BASE_CTL)
+#define IPT_SO_SET_ADD_COUNTERS	(IPT_BASE_CTL + 1)
+#define IPT_SO_SET_MAX		IPT_SO_SET_ADD_COUNTERS
+
+#define IPT_SO_GET_INFO		(IPT_BASE_CTL)
+#define IPT_SO_GET_ENTRIES	(IPT_BASE_CTL + 1)
+#define IPT_SO_GET_MAX		IPT_SO_GET_ENTRIES
+
+/* CONTINUE verdict for targets */
+#define IPT_CONTINUE 0xFFFFFFFF
+
+/* For standard target */
+#define IPT_RETURN (-NF_MAX_VERDICT - 1)
+
+/* TCP matching stuff */
+struct ipt_tcp
+{
+	u_int16_t spts[2];			/* Source port range. */
+	u_int16_t dpts[2];			/* Destination port range. */
+	u_int8_t option;			/* TCP Option iff non-zero*/
+	u_int8_t flg_mask;			/* TCP flags mask byte */
+	u_int8_t flg_cmp;			/* TCP flags compare byte */
+	u_int8_t invflags;			/* Inverse flags */
+};
+
+/* Values for "inv" field in struct ipt_tcp. */
+#define IPT_TCP_INV_SRCPT	0x01	/* Invert the sense of source ports. */
+#define IPT_TCP_INV_DSTPT	0x02	/* Invert the sense of dest ports. */
+#define IPT_TCP_INV_FLAGS	0x04	/* Invert the sense of TCP flags. */
+#define IPT_TCP_INV_OPTION	0x08	/* Invert the sense of option test. */
+#define IPT_TCP_INV_MASK	0x0F	/* All possible flags. */
+
+/* UDP matching stuff */
+struct ipt_udp
+{
+	u_int16_t spts[2];			/* Source port range. */
+	u_int16_t dpts[2];			/* Destination port range. */
+	u_int8_t invflags;			/* Inverse flags */
+};
+
+/* Values for "invflags" field in struct ipt_udp. */
+#define IPT_UDP_INV_SRCPT	0x01	/* Invert the sense of source ports. */
+#define IPT_UDP_INV_DSTPT	0x02	/* Invert the sense of dest ports. */
+#define IPT_UDP_INV_MASK	0x03	/* All possible flags. */
+
+/* ICMP matching stuff */
+struct ipt_icmp
+{
+	u_int8_t type;				/* type to match */
+	u_int8_t code[2];			/* range of code */
+	u_int8_t invflags;			/* Inverse flags */
+};
+
+/* Values for "inv" field for struct ipt_icmp. */
+#define IPT_ICMP_INV	0x01	/* Invert the sense of type/code test */
+
+/* The argument to IPT_SO_GET_INFO */
+struct ipt_getinfo
+{
+	/* Which table: caller fills this in. */
+	char name[IPT_TABLE_MAXNAMELEN];
+
+	/* Kernel fills these in. */
+	/* Which hook entry points are valid: bitmask */
+	unsigned int valid_hooks;
+
+	/* Hook entry points: one per netfilter hook. */
+	unsigned int hook_entry[NF_IP_NUMHOOKS];
+
+	/* Underflow points. */
+	unsigned int underflow[NF_IP_NUMHOOKS];
+
+	/* Number of entries */
+	unsigned int num_entries;
+
+	/* Size of entries. */
+	unsigned int size;
+};
+
+/* The argument to IPT_SO_SET_REPLACE. */
+struct ipt_replace
+{
+	/* Which table. */
+	char name[IPT_TABLE_MAXNAMELEN];
+
+	/* Which hook entry points are valid: bitmask.  You can't
+           change this. */
+	unsigned int valid_hooks;
+
+	/* Number of entries */
+	unsigned int num_entries;
+
+	/* Total size of new entries */
+	unsigned int size;
+
+	/* Hook entry points. */
+	unsigned int hook_entry[NF_IP_NUMHOOKS];
+
+	/* Underflow points. */
+	unsigned int underflow[NF_IP_NUMHOOKS];
+
+	/* Information about old entries: */
+	/* Number of counters (must be equal to current number of entries). */
+	unsigned int num_counters;
+	/* The old entries' counters. */
+	struct ipt_counters *counters;
+
+	/* The entries (hang off end: not really an array). */
+	struct ipt_entry entries[0];
+};
+
+/* The argument to IPT_SO_ADD_COUNTERS. */
+struct ipt_counters_info
+{
+	/* Which table. */
+	char name[IPT_TABLE_MAXNAMELEN];
+
+	unsigned int num_counters;
+
+	/* The counters (actually `number' of these). */
+	struct ipt_counters counters[0];
+};
+
+/* The argument to IPT_SO_GET_ENTRIES. */
+struct ipt_get_entries
+{
+	/* Which table: user fills this in. */
+	char name[IPT_TABLE_MAXNAMELEN];
+
+	/* User fills this in: total entry size. */
+	unsigned int size;
+
+	/* The entries. */
+	unsigned char entries[0];
+};
+
+/* Standard return verdict, or do jump. */
+#define IPT_STANDARD_TARGET ""
+/* Error verdict. */
+#define IPT_ERROR_TARGET "ERROR"
+
+/* Helper functions */
+extern __inline__ struct ipt_entry_target *
+ipt_get_target(struct ipt_entry *e)
+{
+	return (void *)e + e->target_offset;
+}
+
+/* fn returns 0 to continue iteration */
+#define IPT_MATCH_ITERATE(e, fn, args...)	\
+({						\
+	unsigned int __i;			\
+	int __ret = 0;				\
+	struct ipt_entry_match *__m;		\
+						\
+	for (__i = sizeof(struct ipt_entry);	\
+	     __i < (e)->target_offset;		\
+	     __i += __m->match_size) {		\
+		__m = (void *)(e) + __i;	\
+						\
+		__ret = fn(__m , ## args);	\
+		if (__ret != 0)			\
+			break;			\
+	}					\
+	__ret;					\
+})
+
+/* fn returns 0 to continue iteration */
+#define IPT_ENTRY_ITERATE(entries, size, fn, args...)		\
+({								\
+	unsigned int __i;					\
+	int __ret = 0;						\
+	struct ipt_entry *__e;					\
+								\
+	for (__i = 0; __i < (size); __i += __e->next_offset) {	\
+		__e = (void *)(entries) + __i;			\
+								\
+		__ret = fn(__e , ## args);			\
+		if (__ret != 0)					\
+			break;					\
+	}							\
+	__ret;							\
+})
+
+/*
+ *	Main firewall chains definitions and global var's definitions.
+ */
+#ifdef __KERNEL__
+
+#include <linux/init.h>
+extern void ipt_init(void) __init;
+
+struct ipt_match
+{
+	struct list_head list;
+
+	const char name[IPT_FUNCTION_MAXNAMELEN];
+
+	/* Return true or false: return FALSE and set *hotdrop = 1 to
+           force immediate packet drop. */
+	int (*match)(const struct sk_buff *skb,
+		     const struct net_device *in,
+		     const struct net_device *out,
+		     const void *matchinfo,
+		     int offset,
+		     const void *hdr,
+		     u_int16_t datalen,
+		     int *hotdrop);
+
+	/* Called when user tries to insert an entry of this type. */
+	/* Should return true or false. */
+	int (*checkentry)(const char *tablename,
+			  const struct ipt_ip *ip,
+			  void *matchinfo,
+			  unsigned int matchinfosize,
+			  unsigned int hook_mask);
+
+	/* Set this to THIS_MODULE if you are a module, otherwise NULL */
+	struct module *me;
+};
+
+/* Registration hooks for targets. */
+struct ipt_target
+{
+	struct list_head list;
+
+	const char name[IPT_FUNCTION_MAXNAMELEN];
+
+	/* Returns verdict. */
+	unsigned int (*target)(struct sk_buff **pskb,
+			       unsigned int hooknum,
+			       const struct net_device *in,
+			       const struct net_device *out,
+			       const void *targinfo,
+			       void *userdata);
+
+	/* 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. */
+	int (*checkentry)(const char *tablename,
+			  const struct ipt_entry *e,
+			  void *targinfo,
+			  unsigned int targinfosize,
+			  unsigned int hook_mask);
+
+	/* Set this to THIS_MODULE if you are a module, otherwise NULL */
+	struct module *me;
+};
+
+extern int ipt_register_target(struct ipt_target *target);
+extern void ipt_unregister_target(struct ipt_target *target);
+
+extern int ipt_register_match(struct ipt_match *match);
+extern void ipt_unregister_match(struct ipt_match *match);
+
+/* Furniture shopping... */
+struct ipt_table
+{
+	struct list_head list;
+
+	/* A unique name... */
+	char name[IPT_TABLE_MAXNAMELEN];
+
+	/* Seed table: copied in register_table */
+	struct ipt_replace *table;
+
+	/* What hooks you will enter on */
+	unsigned int valid_hooks;
+
+	/* Lock for the curtain */
+	rwlock_t lock;
+
+	/* Man behind the curtain... */
+	struct ipt_table_info *private;
+};
+
+extern int ipt_register_table(struct ipt_table *table);
+extern void ipt_unregister_table(struct ipt_table *table);
+extern unsigned int ipt_do_table(struct sk_buff **pskb,
+				 unsigned int hook,
+				 const struct net_device *in,
+				 const struct net_device *out,
+				 struct ipt_table *table,
+				 void *userdata);
+
+#define IPT_ALIGN(s) (((s) + (__alignof__(struct ipt_match)-1)) & ~(__alignof__(struct ipt_match)-1))
+#endif /*__KERNEL__*/
+#endif /* _IPTABLES_H */