/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ /* * 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 #include <linux/types.h> #include <linux/if.h> #include <linux/netfilter_arp.h> #include <linux/netfilter/x_tables.h> #define ARPT_FUNCTION_MAXNAMELEN XT_FUNCTION_MAXNAMELEN #define ARPT_TABLE_MAXNAMELEN XT_TABLE_MAXNAMELEN #define arpt_entry_target xt_entry_target #define arpt_standard_target xt_standard_target #define arpt_error_target xt_error_target #define ARPT_CONTINUE XT_CONTINUE #define ARPT_RETURN XT_RETURN #define arpt_counters_info xt_counters_info #define arpt_counters xt_counters #define ARPT_STANDARD_TARGET XT_STANDARD_TARGET #define ARPT_ERROR_TARGET XT_ERROR_TARGET #define ARPT_ENTRY_ITERATE(entries, size, fn, args...) \ XT_ENTRY_ITERATE(struct arpt_entry, entries, size, fn, ## args) #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 */ __u8 arhln, arhln_mask; struct arpt_devaddr_info src_devaddr; struct arpt_devaddr_info tgt_devaddr; /* ARP operation code. */ __be16 arpop, arpop_mask; /* ARP hardware address and protocol address format. */ __be16 arhrd, arhrd_mask; __be16 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 */ __u8 flags; /* Inverse flags */ __u16 invflags; }; /* 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 */ __u16 target_offset; /* Size of arpt_entry + matches + target */ __u16 next_offset; /* Back pointer */ unsigned int comefrom; /* Packet and byte counters. */ struct xt_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. * * ATTENTION: check linux/in.h before adding new number here. */ #define ARPT_BASE_CTL 96 #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 (APRT_BASE_CTL + 2) */ #define ARPT_SO_GET_REVISION_TARGET (ARPT_BASE_CTL + 3) #define ARPT_SO_GET_MAX (ARPT_SO_GET_REVISION_TARGET) /* The argument to ARPT_SO_GET_INFO */ struct arpt_getinfo { /* Which table: caller fills this in. */ char name[XT_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[XT_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 xt_counters *counters; /* The entries (hang off end: not really an array). */ struct arpt_entry entries[0]; }; /* The argument to ARPT_SO_GET_ENTRIES. */ struct arpt_get_entries { /* Which table: user fills this in. */ char name[XT_TABLE_MAXNAMELEN]; /* User fills this in: total entry size. */ unsigned int size; /* The entries. */ struct arpt_entry entrytable[0]; }; /* Helper functions */ static __inline__ struct xt_entry_target *arpt_get_target(struct arpt_entry *e) { return (struct xt_entry_target *)((char *)e + e->target_offset); } /* * Main firewall chains definitions and global var's definitions. */ #endif /* _ARPTABLES_H */