| /* |
| * Format of an ARP firewall descriptor |
| * |
| * src, tgt, src_mask, tgt_mask, arpop, arpop_mask are always stored in |
| * network byte order. |
| * flags are stored in host byte order (of course). |
| */ |
| |
| #ifndef _ARPTABLES_H |
| #define _ARPTABLES_H |
| |
| #ifdef __KERNEL__ |
| #include <linux/if.h> |
| #include <linux/types.h> |
| #include <linux/in.h> |
| #include <linux/if_arp.h> |
| #include <linux/skbuff.h> |
| #endif |
| #include <linux/compiler.h> |
| #include <linux/netfilter_arp.h> |
| |
| #define ARPT_FUNCTION_MAXNAMELEN 30 |
| #define ARPT_TABLE_MAXNAMELEN 32 |
| |
| #define ARPT_DEV_ADDR_LEN_MAX 16 |
| |
| struct arpt_devaddr_info { |
| char addr[ARPT_DEV_ADDR_LEN_MAX]; |
| char mask[ARPT_DEV_ADDR_LEN_MAX]; |
| }; |
| |
| /* Yes, Virginia, you have to zero the padding. */ |
| struct arpt_arp { |
| /* Source and target IP addr */ |
| struct in_addr src, tgt; |
| /* Mask for src and target IP addr */ |
| struct in_addr smsk, tmsk; |
| |
| /* Device hw address length, src+target device addresses */ |
| u_int8_t arhln, arhln_mask; |
| struct arpt_devaddr_info src_devaddr; |
| struct arpt_devaddr_info tgt_devaddr; |
| |
| /* ARP operation code. */ |
| u_int16_t arpop, arpop_mask; |
| |
| /* ARP hardware address and protocol address format. */ |
| u_int16_t arhrd, arhrd_mask; |
| u_int16_t arpro, arpro_mask; |
| |
| /* The protocol address length is only accepted if it is 4 |
| * so there is no use in offering a way to do filtering on it. |
| */ |
| |
| char iniface[IFNAMSIZ], outiface[IFNAMSIZ]; |
| unsigned char iniface_mask[IFNAMSIZ], outiface_mask[IFNAMSIZ]; |
| |
| /* Flags word */ |
| u_int8_t flags; |
| /* Inverse flags */ |
| u_int16_t invflags; |
| }; |
| |
| struct arpt_entry_target |
| { |
| union { |
| struct { |
| u_int16_t target_size; |
| |
| /* Used by userspace */ |
| char name[ARPT_FUNCTION_MAXNAMELEN-1]; |
| u_int8_t revision; |
| } user; |
| struct { |
| u_int16_t target_size; |
| |
| /* Used inside the kernel */ |
| struct arpt_target *target; |
| } kernel; |
| |
| /* Total length */ |
| u_int16_t target_size; |
| } u; |
| |
| unsigned char data[0]; |
| }; |
| |
| struct arpt_standard_target |
| { |
| struct arpt_entry_target target; |
| int verdict; |
| }; |
| |
| struct arpt_counters |
| { |
| u_int64_t pcnt, bcnt; /* Packet and byte counters */ |
| }; |
| |
| /* Values for "flag" field in struct arpt_ip (general arp structure). |
| * No flags defined yet. |
| */ |
| #define ARPT_F_MASK 0x00 /* All possible flag bits mask. */ |
| |
| /* Values for "inv" field in struct arpt_arp. */ |
| #define ARPT_INV_VIA_IN 0x0001 /* Invert the sense of IN IFACE. */ |
| #define ARPT_INV_VIA_OUT 0x0002 /* Invert the sense of OUT IFACE */ |
| #define ARPT_INV_SRCIP 0x0004 /* Invert the sense of SRC IP. */ |
| #define ARPT_INV_TGTIP 0x0008 /* Invert the sense of TGT IP. */ |
| #define ARPT_INV_SRCDEVADDR 0x0010 /* Invert the sense of SRC DEV ADDR. */ |
| #define ARPT_INV_TGTDEVADDR 0x0020 /* Invert the sense of TGT DEV ADDR. */ |
| #define ARPT_INV_ARPOP 0x0040 /* Invert the sense of ARP OP. */ |
| #define ARPT_INV_ARPHRD 0x0080 /* Invert the sense of ARP HRD. */ |
| #define ARPT_INV_ARPPRO 0x0100 /* Invert the sense of ARP PRO. */ |
| #define ARPT_INV_ARPHLN 0x0200 /* Invert the sense of ARP HLN. */ |
| #define ARPT_INV_MASK 0x03FF /* All possible flag bits mask. */ |
| |
| /* This structure defines each of the firewall rules. Consists of 3 |
| parts which are 1) general ARP header stuff 2) match specific |
| stuff 3) the target to perform if the rule matches */ |
| struct arpt_entry |
| { |
| struct arpt_arp arp; |
| |
| /* Size of arpt_entry + matches */ |
| u_int16_t target_offset; |
| /* Size of arpt_entry + matches + target */ |
| u_int16_t next_offset; |
| |
| /* Back pointer */ |
| unsigned int comefrom; |
| |
| /* Packet and byte counters. */ |
| struct arpt_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 ARPT_BASE_CTL 96 /* base for firewall socket options */ |
| |
| #define ARPT_SO_SET_REPLACE (ARPT_BASE_CTL) |
| #define ARPT_SO_SET_ADD_COUNTERS (ARPT_BASE_CTL + 1) |
| #define ARPT_SO_SET_MAX ARPT_SO_SET_ADD_COUNTERS |
| |
| #define ARPT_SO_GET_INFO (ARPT_BASE_CTL) |
| #define ARPT_SO_GET_ENTRIES (ARPT_BASE_CTL + 1) |
| /* #define ARPT_SO_GET_REVISION_MATCH (ARPT_BASE_CTL + 2)*/ |
| #define ARPT_SO_GET_REVISION_TARGET (ARPT_BASE_CTL + 3) |
| #define ARPT_SO_GET_MAX ARPT_SO_GET_REVISION_TARGET |
| |
| /* CONTINUE verdict for targets */ |
| #define ARPT_CONTINUE 0xFFFFFFFF |
| |
| /* For standard target */ |
| #define ARPT_RETURN (-NF_REPEAT - 1) |
| |
| /* The argument to ARPT_SO_GET_INFO */ |
| struct arpt_getinfo |
| { |
| /* Which table: caller fills this in. */ |
| char name[ARPT_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_ARP_NUMHOOKS]; |
| |
| /* Underflow points. */ |
| unsigned int underflow[NF_ARP_NUMHOOKS]; |
| |
| /* Number of entries */ |
| unsigned int num_entries; |
| |
| /* Size of entries. */ |
| unsigned int size; |
| }; |
| |
| /* The argument to ARPT_SO_SET_REPLACE. */ |
| struct arpt_replace |
| { |
| /* Which table. */ |
| char name[ARPT_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_ARP_NUMHOOKS]; |
| |
| /* Underflow points. */ |
| unsigned int underflow[NF_ARP_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 arpt_counters __user *counters; |
| |
| /* The entries (hang off end: not really an array). */ |
| struct arpt_entry entries[0]; |
| }; |
| |
| /* The argument to ARPT_SO_ADD_COUNTERS. */ |
| struct arpt_counters_info |
| { |
| /* Which table. */ |
| char name[ARPT_TABLE_MAXNAMELEN]; |
| |
| unsigned int num_counters; |
| |
| /* The counters (actually `number' of these). */ |
| struct arpt_counters counters[0]; |
| }; |
| |
| /* The argument to ARPT_SO_GET_ENTRIES. */ |
| struct arpt_get_entries |
| { |
| /* Which table: user fills this in. */ |
| char name[ARPT_TABLE_MAXNAMELEN]; |
| |
| /* User fills this in: total entry size. */ |
| unsigned int size; |
| |
| /* The entries. */ |
| struct arpt_entry entrytable[0]; |
| }; |
| |
| /* The argument to ARPT_SO_GET_REVISION_*. Returns highest revision |
| * kernel supports, if >= revision. */ |
| struct arpt_get_revision |
| { |
| char name[ARPT_FUNCTION_MAXNAMELEN-1]; |
| |
| u_int8_t revision; |
| }; |
| |
| /* Standard return verdict, or do jump. */ |
| #define ARPT_STANDARD_TARGET "" |
| /* Error verdict. */ |
| #define ARPT_ERROR_TARGET "ERROR" |
| |
| /* Helper functions */ |
| static __inline__ struct arpt_entry_target *arpt_get_target(struct arpt_entry *e) |
| { |
| return (void *)e + e->target_offset; |
| } |
| |
| /* fn returns 0 to continue iteration */ |
| #define ARPT_ENTRY_ITERATE(entries, size, fn, args...) \ |
| ({ \ |
| unsigned int __i; \ |
| int __ret = 0; \ |
| struct arpt_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__ |
| |
| /* Registration hooks for targets. */ |
| struct arpt_target |
| { |
| struct list_head list; |
| |
| const char name[ARPT_FUNCTION_MAXNAMELEN-1]; |
| |
| u_int8_t revision; |
| |
| /* 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 arpt_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); |
| |
| /* Set this to THIS_MODULE if you are a module, otherwise NULL */ |
| struct module *me; |
| }; |
| |
| extern int arpt_register_target(struct arpt_target *target); |
| extern void arpt_unregister_target(struct arpt_target *target); |
| |
| /* Furniture shopping... */ |
| struct arpt_table |
| { |
| struct list_head list; |
| |
| /* A unique name... */ |
| char name[ARPT_TABLE_MAXNAMELEN]; |
| |
| /* What hooks you will enter on */ |
| unsigned int valid_hooks; |
| |
| /* Lock for the curtain */ |
| rwlock_t lock; |
| |
| /* Man behind the curtain... */ |
| struct arpt_table_info *private; |
| |
| /* Set this to THIS_MODULE if you are a module, otherwise NULL */ |
| struct module *me; |
| }; |
| |
| extern int arpt_register_table(struct arpt_table *table, |
| const struct arpt_replace *repl); |
| extern void arpt_unregister_table(struct arpt_table *table); |
| extern unsigned int arpt_do_table(struct sk_buff **pskb, |
| unsigned int hook, |
| const struct net_device *in, |
| const struct net_device *out, |
| struct arpt_table *table, |
| void *userdata); |
| |
| #define ARPT_ALIGN(s) (((s) + (__alignof__(struct arpt_entry)-1)) & ~(__alignof__(struct arpt_entry)-1)) |
| #endif /*__KERNEL__*/ |
| #endif /* _ARPTABLES_H */ |