diff options
Diffstat (limited to 'include/linux/netfilter_ipv4/ip_tables.h')
| -rw-r--r-- | include/linux/netfilter_ipv4/ip_tables.h | 490 |
1 files changed, 490 insertions, 0 deletions
diff --git a/include/linux/netfilter_ipv4/ip_tables.h b/include/linux/netfilter_ipv4/ip_tables.h new file mode 100644 index 00000000000..12ce47808e7 --- /dev/null +++ b/include/linux/netfilter_ipv4/ip_tables.h @@ -0,0 +1,490 @@ +/* + * 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/compiler.h> +#include <linux/netfilter_ipv4.h> + +#define IPT_FUNCTION_MAXNAMELEN 30 +#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 +{ + union { + struct { + u_int16_t match_size; + + /* Used by userspace */ + char name[IPT_FUNCTION_MAXNAMELEN-1]; + + u_int8_t revision; + } user; + struct { + u_int16_t match_size; + + /* Used inside the kernel */ + struct ipt_match *match; + } kernel; + + /* Total length */ + u_int16_t match_size; + } u; + + unsigned char data[0]; +}; + +struct ipt_entry_target +{ + union { + struct { + u_int16_t target_size; + + /* Used by userspace */ + char name[IPT_FUNCTION_MAXNAMELEN-1]; + + u_int8_t revision; + } user; + struct { + u_int16_t target_size; + + /* Used inside the kernel */ + struct ipt_target *target; + } kernel; + + /* Total length */ + u_int16_t target_size; + } 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_REVISION_MATCH (IPT_BASE_CTL + 2) +#define IPT_SO_GET_REVISION_TARGET (IPT_BASE_CTL + 3) +#define IPT_SO_GET_MAX IPT_SO_GET_REVISION_TARGET + +/* CONTINUE verdict for targets */ +#define IPT_CONTINUE 0xFFFFFFFF + +/* For standard target */ +#define IPT_RETURN (-NF_REPEAT - 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 __user *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. */ + struct ipt_entry entrytable[0]; +}; + +/* The argument to IPT_SO_GET_REVISION_*. Returns highest revision + * kernel supports, if >= revision. */ +struct ipt_get_revision +{ + char name[IPT_FUNCTION_MAXNAMELEN-1]; + + u_int8_t revision; +}; + +/* Standard return verdict, or do jump. */ +#define IPT_STANDARD_TARGET "" +/* Error verdict. */ +#define IPT_ERROR_TARGET "ERROR" + +/* Helper functions */ +static __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 *__match; \ + \ + for (__i = sizeof(struct ipt_entry); \ + __i < (e)->target_offset; \ + __i += __match->u.match_size) { \ + __match = (void *)(e) + __i; \ + \ + __ret = fn(__match , ## 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 *__entry; \ + \ + for (__i = 0; __i < (size); __i += __entry->next_offset) { \ + __entry = (void *)(entries) + __i; \ + \ + __ret = fn(__entry , ## 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-1]; + + u_int8_t revision; + + /* Return true or false: return FALSE and set *hotdrop = 1 to + force immediate packet drop. */ + /* Arguments changed since 2.4, as this must now handle + non-linear skbs, using skb_copy_bits and + skb_ip_make_writable. */ + int (*match)(const struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + const void *matchinfo, + int offset, + 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); + + /* Called when entry of this type deleted. */ + void (*destroy)(void *matchinfo, unsigned int matchinfosize); + + /* Set this to THIS_MODULE. */ + struct module *me; +}; + +/* Registration hooks for targets. */ +struct ipt_target +{ + struct list_head list; + + const char name[IPT_FUNCTION_MAXNAMELEN-1]; + + u_int8_t revision; + + /* 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); + + /* Called when entry of this type deleted. */ + void (*destroy)(void *targinfo, unsigned int targinfosize); + + /* Returns verdict. Argument order changed since 2.4, as this + must now handle non-linear skbs, using skb_copy_bits and + skb_ip_make_writable. */ + unsigned int (*target)(struct sk_buff **pskb, + const struct net_device *in, + const struct net_device *out, + unsigned int hooknum, + const void *targinfo, + void *userdata); + + /* Set this to THIS_MODULE. */ + 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]; + + /* 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; + + /* Set to THIS_MODULE. */ + struct module *me; +}; + +/* net/sched/ipt.c: Gimme access to your targets! Gets target->me. */ +extern struct ipt_target *ipt_find_target(const char *name, u8 revision); + +/* Standard entry. */ +struct ipt_standard +{ + struct ipt_entry entry; + struct ipt_standard_target target; +}; + +struct ipt_error_target +{ + struct ipt_entry_target target; + char errorname[IPT_FUNCTION_MAXNAMELEN]; +}; + +struct ipt_error +{ + struct ipt_entry entry; + struct ipt_error_target target; +}; + +extern int ipt_register_table(struct ipt_table *table, + const struct ipt_replace *repl); +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_entry)-1)) & ~(__alignof__(struct ipt_entry)-1)) +#endif /*__KERNEL__*/ +#endif /* _IPTABLES_H */ |