/*
 * Copyright (c) 1993 Daniel Boulet
 * Copyright (c) 1994 Ugen J.S.Antsilevich
 *
 * Redistribution and use in source forms, with and without modification,
 * are permitted provided that this entire comment appears intact.
 *
 * Redistribution in binary form may occur without any restrictions.
 * Obviously, it would be nice if you gave credit where credit is due
 * but requiring it would be too onerous.
 *
 * This software is provided ``AS IS'' without any warranties of any kind.
 *
 *	$Id: ip6_fw.h,v 1.1 1999/08/06 14:10:09 itojun Exp $
 * $FreeBSD$
 */

#ifndef _IP6_FW_H
#define _IP6_FW_H

#include <net/if.h>

/*
 * This union structure identifies an interface, either explicitly
 * by name or implicitly by IP address. The flags IP_FW_F_IIFNAME
 * and IP_FW_F_OIFNAME say how to interpret this structure. An
 * interface unit number of -1 matches any unit number, while an
 * IP address of 0.0.0.0 indicates matches any interface.
 *
 * The receive and transmit interfaces are only compared against the
 * the packet if the corresponding bit (IP_FW_F_IIFACE or IP_FW_F_OIFACE)
 * is set. Note some packets lack a receive or transmit interface
 * (in which case the missing "interface" never matches).
 */

union ip6_fw_if {
	struct	in6_addr fu_via_ip6;	/* Specified by IPv6 address */
	struct {			/* Specified by interface name */
#define FW_IFNLEN     IFNAMSIZ
		char	name[FW_IFNLEN];
		short	unit;		/* -1 means match any unit */
    } fu_via_if;
};

/*
 * Format of an IP firewall descriptor
 *
 * fw_src, fw_dst, fw_smsk, fw_dmsk are always stored in network byte order.
 * fw_flg and fw_n*p are stored in host byte order (of course).
 * Port numbers are stored in HOST byte order.
 * Warning: setsockopt() will fail if sizeof(struct ip_fw) > MLEN (108)
 */

struct ip6_fw {
	u_long	fw_pcnt,fw_bcnt;		/* Packet and byte counters */
	struct	in6_addr fw_src, fw_dst; /* Source and destination IPv6 addr */
	/* Mask for src and dest IPv6 addr */
	struct	in6_addr fw_smsk, fw_dmsk;
	u_short	fw_number;			/* Rule number */
	u_short	fw_flg;				/* Flags word */
#define	IPV6_FW_MAX_PORTS	10		/* A reasonable maximum */
	/* Array of port numbers to match */
	u_short	fw_pts[IPV6_FW_MAX_PORTS];
	u_char	fw_ip6opt,fw_ip6nopt;		/* IPv6 options set/unset */
	u_char	fw_tcpf,fw_tcpnf;		/* TCP flags set/unset */
#define	IPV6_FW_ICMPTYPES_DIM (32 / (sizeof(unsigned) * 8))
	/* ICMP types bitmap */
	unsigned	fw_icmp6types[IPV6_FW_ICMPTYPES_DIM];
	long	timestamp;		/* timestamp (tv_sec) of last match */
	/* Incoming and outgoing interfaces */
	union	ip6_fw_if fw_in_if, fw_out_if;
	union {
		u_short	fu_divert_port;		/* Divert/tee port (options IP6DIVERT) */
		u_short	fu_skipto_rule;		/* SKIPTO command rule number */
		u_short	fu_reject_code;		/* REJECT response code */
	} fw_un;
	u_char	fw_prot;			/* IPv6 protocol */
	u_char	fw_nports;	/* N'of src ports and # of dst ports */
				/* in ports array (dst ports follow */
				/* src ports; max of 10 ports in all; */
				/* count of 0 means match all ports) */
};

#define	IPV6_FW_GETNSRCP(rule)		((rule)->fw_nports & 0x0f)
#define	IPV6_FW_SETNSRCP(rule, n)		do {			\
					  (rule)->fw_nports &= ~0x0f;	\
					  (rule)->fw_nports |= (n);	\
					} while (0)
#define	IPV6_FW_GETNDSTP(rule)		((rule)->fw_nports >> 4)
#define	IPV6_FW_SETNDSTP(rule, n)		do {			\
					  (rule)->fw_nports &= ~0xf0;	\
					  (rule)->fw_nports |= (n) << 4;\
					} while (0)

#define	fw_divert_port	fw_un.fu_divert_port
#define	fw_skipto_rule	fw_un.fu_skipto_rule
#define	fw_reject_code	fw_un.fu_reject_code

struct	ip6_fw_chain {
	LIST_ENTRY(ip6_fw_chain) chain;
	struct	ip6_fw    *rule;
};

/*
 * Values for "flags" field .
 */
#define	IPV6_FW_F_IN		0x0001	/* Check inbound packets	*/
#define	IPV6_FW_F_OUT		0x0002	/* Check outbound packets	*/
#define	IPV6_FW_F_IIFACE	0x0004	/* Apply inbound interface test	*/
#define	IPV6_FW_F_OIFACE	0x0008	/* Apply outbound interface test */

#define	IPV6_FW_F_COMMAND 	0x0070	/* Mask for type of chain entry: */
#define	IPV6_FW_F_DENY		0x0000	/* This is a deny rule		*/
#define	IPV6_FW_F_REJECT	0x0010	/* Deny and send a response packet */
#define	IPV6_FW_F_ACCEPT	0x0020	/* This is an accept rule	*/
#define	IPV6_FW_F_COUNT		0x0030	/* This is a count rule		*/
#define	IPV6_FW_F_DIVERT	0x0040	/* This is a divert rule	*/
#define	IPV6_FW_F_TEE		0x0050	/* This is a tee rule		*/
#define	IPV6_FW_F_SKIPTO	0x0060	/* This is a skipto rule	*/

#define	IPV6_FW_F_PRN		0x0080	/* Print if this rule matches	*/

#define	IPV6_FW_F_SRNG		0x0100	/* The first two src ports are a min  *
					 * and max range (stored in host byte *
					 * order). */

#define	IPV6_FW_F_DRNG	0x0200	/* The first two dst ports are a min	*
				 * and max range (stored in host byte	*
				 * order).				*/

/* In interface by name/unit (not IP)	*/
#define	IPV6_FW_F_IIFNAME	0x0400
/* Out interface by name/unit (not IP)	*/
#define	IPV6_FW_F_OIFNAME	0x0800

#define	IPV6_FW_F_INVSRC	0x1000	/* Invert sense of src check	*/
#define	IPV6_FW_F_INVDST	0x2000	/* Invert sense of dst check	*/

#define	IPV6_FW_F_FRAG		0x4000	/* Fragment			*/

#define	IPV6_FW_F_ICMPBIT 	0x8000	/* ICMP type bitmap is valid	*/

#define	IPV6_FW_F_MASK		0xFFFF	/* All possible flag bits mask	*/

/*
 * For backwards compatibility with rules specifying "via iface" but
 * not restricted to only "in" or "out" packets, we define this combination
 * of bits to represent this configuration.
 */

#define	IF6_FW_F_VIAHACK	(IPV6_FW_F_IN|IPV6_FW_F_OUT|IPV6_FW_F_IIFACE|\
				 IPV6_FW_F_OIFACE)

/*
 * Definitions for REJECT response codes.
 * Values less than 256 correspond to ICMP unreachable codes.
 */
#define	IPV6_FW_REJECT_RST	0x0100		/* TCP packets: send RST */

/*
 * Definitions for IPv6 option names.
 */
#define	IPV6_FW_IP6OPT_HOPOPT	0x01
#define	IPV6_FW_IP6OPT_ROUTE	0x02
#define	IPV6_FW_IP6OPT_FRAG	0x04
#define	IPV6_FW_IP6OPT_ESP	0x08
#define	IPV6_FW_IP6OPT_AH	0x10
#define	IPV6_FW_IP6OPT_NONXT	0x20
#define	IPV6_FW_IP6OPT_OPTS	0x40

/*
 * Definitions for TCP flags.
 */
#define	IPV6_FW_TCPF_FIN	TH_FIN
#define	IPV6_FW_TCPF_SYN	TH_SYN
#define	IPV6_FW_TCPF_RST	TH_RST
#define	IPV6_FW_TCPF_PSH	TH_PUSH
#define	IPV6_FW_TCPF_ACK	TH_ACK
#define	IPV6_FW_TCPF_URG	TH_URG
#define	IPV6_FW_TCPF_ESTAB	0x40

/*
 * Main firewall chains definitions and global var's definitions.
 */
#ifdef _KERNEL

/*
 * Function definitions.
 */
void	ip6_fw_init(void);

/* Firewall hooks */
struct	ip6_hdr;
typedef	int	ip6_fw_chk_t __P((struct ip6_hdr**, struct ifnet*,
				u_short *, struct mbuf**));
typedef	int	ip6_fw_ctl_t __P((int, struct mbuf**));
extern	ip6_fw_chk_t *ip6_fw_chk_ptr;
extern	ip6_fw_ctl_t *ip6_fw_ctl_ptr;

#endif /* _KERNEL */

#endif /* _IP6_FW_H */