freebsd-dev/sys/netinet/ip_fw.h

/*
 * 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.
 *
 * $FreeBSD$
 */

#ifndef _IP_FW_H
#define _IP_FW_H

#include <sys/queue.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 ip_fw_if {
    struct in_addr fu_via_ip;	/* Specified by IP address */
    struct {			/* Specified by interface name */
#define FW_IFNLEN     10 /* need room ! was 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.
 */

struct ip_fw {
    u_int64_t fw_pcnt,fw_bcnt;		/* Packet and byte counters */
    struct in_addr fw_src, fw_dst;	/* Source and destination IP addr */
    struct in_addr fw_smsk, fw_dmsk;	/* Mask for src and dest IP addr */
    u_short fw_number;			/* Rule number */
    u_int fw_flg;			/* Operational Flags word */
#define IP_FW_MAX_PORTS	10		/* A reasonable maximum */
	union {
	u_short fw_pts[IP_FW_MAX_PORTS];	/* Array of port numbers to match */
#define IP_FW_ICMPTYPES_MAX	128
#define IP_FW_ICMPTYPES_DIM	(IP_FW_ICMPTYPES_MAX / (sizeof(unsigned) * 8))
	unsigned fw_icmptypes[IP_FW_ICMPTYPES_DIM]; /* ICMP types bitmap */
	} fw_uar;
    u_int fw_ipflg;			/* IP flags word */
    u_char fw_ipopt,fw_ipnopt;		/* IP options set/unset */
    u_short fw_iplen, fw_ipid;		/* IP length, identification */
    u_char fw_iptos, fw_ipntos;		/* IP type of service set/unset */
    u_char fw_ipttl;			/* IP time to live */
    u_int fw_ipver:4;			/* IP version */
    u_char fw_tcpopt,fw_tcpnopt;	/* TCP options set/unset */
    u_char fw_tcpf,fw_tcpnf;		/* TCP flags set/unset */
    u_int32_t fw_tcpseq, fw_tcpack;	/* TCP sequence and acknowledgement */
    u_short fw_tcpwin;			/* TCP window size */
    long timestamp;			/* timestamp (tv_sec) of last match */
    union ip_fw_if fw_in_if, fw_out_if;	/* Incoming and outgoing interfaces */
    union {
	u_short fu_divert_port;		/* Divert/tee port (options IPDIVERT) */
	u_short fu_pipe_nr;		/* queue number (option DUMMYNET) */
	u_short fu_skipto_rule;		/* SKIPTO command rule number */
	u_short fu_reject_code;		/* REJECT response code */
	struct sockaddr_in fu_fwd_ip;
    } fw_un;
    u_char fw_prot;			/* IP protocol */
	/*
	 * 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)
	 */
    u_char fw_nports;
    void *pipe_ptr;                    /* flow_set ptr for dummynet pipe */
    void *next_rule_ptr ;              /* next rule in case of match */
    uid_t fw_uid;			/* uid to match */
    gid_t fw_gid;			/* gid to match */
    int fw_logamount;			/* amount to log */
    u_int64_t fw_loghighest;		/* highest number packet to log */
};

/*
 * extended ipfw structure... some fields in the original struct
 * can be used to pass parameters up/down, namely pointers
 *     void *pipe_ptr
 *     void *next_rule_ptr 
 * some others can be used to pass parameters down, namely counters etc.
 *     u_int64_t fw_pcnt,fw_bcnt;
 *     long timestamp;
 */

struct ip_fw_ext {             /* extended structure */
    struct ip_fw rule;      /* must be at offset 0 */
    long    dont_match_prob;        /* 0x7fffffff means 1.0, always fail */
    u_int   dyn_type;  /* type for dynamic rule */
};

#define IP_FW_GETNSRCP(rule)		((rule)->fw_nports & 0x0f)
#define IP_FW_SETNSRCP(rule, n)		do {				\
					  (rule)->fw_nports &= ~0x0f;	\
					  (rule)->fw_nports |= (n);	\
					} while (0)
#define IP_FW_GETNDSTP(rule)		((rule)->fw_nports >> 4)
#define IP_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
#define fw_pipe_nr	fw_un.fu_pipe_nr
#define fw_fwd_ip	fw_un.fu_fwd_ip

struct ip_fw_chain {
	LIST_ENTRY(ip_fw_chain) next;
	struct ip_fw *rule;
};

/*
 * Flow mask/flow id for each queue.
 */
struct ipfw_flow_id {
    u_int32_t dst_ip, src_ip ;
    u_int16_t dst_port, src_port ; 
    u_int8_t proto ;    
    u_int8_t flags ;    /* protocol-specific flags */
} ;

/*
 * dynamic ipfw rule
 */
struct ipfw_dyn_rule {
    struct ipfw_dyn_rule *next ;

    struct ipfw_flow_id id ;
    struct ipfw_flow_id mask ;
    struct ip_fw_chain *chain ;		/* pointer to parent rule	*/
    u_int32_t type ;			/* rule type			*/
    u_int32_t expire ;			/* expire time			*/
    u_int64_t pcnt, bcnt;		/* match counters		*/
    u_int32_t bucket ;			/* which bucket in hash table	*/
    u_int32_t state ;			/* state of this rule (typ. a   */
					/* combination of TCP flags)	*/
} ;

/*
 * Values for "flags" field .
 */
#define IP_FW_F_COMMAND 0x000000ff	/* Mask for type of chain entry:	*/
#define IP_FW_F_DENY	0x00000000	/* This is a deny rule			*/
#define IP_FW_F_REJECT	0x00000001	/* Deny and send a response packet	*/
#define IP_FW_F_ACCEPT	0x00000002	/* This is an accept rule		*/
#define IP_FW_F_COUNT	0x00000003	/* This is a count rule			*/
#define IP_FW_F_DIVERT	0x00000004	/* This is a divert rule		*/
#define IP_FW_F_TEE	0x00000005	/* This is a tee rule			*/
#define IP_FW_F_SKIPTO	0x00000006	/* This is a skipto rule		*/
#define IP_FW_F_FWD	0x00000007	/* This is a "change forwarding address" rule */
#define IP_FW_F_PIPE	0x00000008	/* This is a dummynet rule */
#define IP_FW_F_QUEUE	0x00000009	/* This is a dummynet queue */

#define IP_FW_F_IN	0x00000100	/* Check inbound packets		*/
#define IP_FW_F_OUT	0x00000200	/* Check outbound packets		*/
#define IP_FW_F_IIFACE	0x00000400	/* Apply inbound interface test		*/
#define IP_FW_F_OIFACE	0x00000800	/* Apply outbound interface test	*/

#define IP_FW_F_PRN	0x00001000	/* Print if this rule matches		*/

#define IP_FW_F_SRNG	0x00002000	/* The first two src ports are a min	*
					 * and max range (stored in host byte	*
					 * order).				*/

#define IP_FW_F_DRNG	0x00004000	/* The first two dst ports are a min	*
					 * and max range (stored in host byte	*
					 * order).				*/

#define IP_FW_F_FRAG	0x00008000	/* Fragment				*/

#define IP_FW_F_IIFNAME	0x00010000	/* In interface by name/unit (not IP)	*/
#define IP_FW_F_OIFNAME	0x00020000	/* Out interface by name/unit (not IP)	*/

#define IP_FW_F_INVSRC	0x00040000	/* Invert sense of src check		*/
#define IP_FW_F_INVDST	0x00080000	/* Invert sense of dst check		*/

#define IP_FW_F_ICMPBIT 0x00100000	/* ICMP type bitmap is valid		*/

#define IP_FW_F_UID	0x00200000	/* filter by uid			*/

#define IP_FW_F_GID	0x00400000	/* filter by gid			*/

#define IP_FW_F_RND_MATCH 0x00800000	/* probabilistic rule match		*/
#define IP_FW_F_SMSK	0x01000000	/* src-port + mask 			*/
#define IP_FW_F_DMSK	0x02000000	/* dst-port + mask 			*/
#define	IP_FW_BRIDGED	0x04000000	/* only match bridged packets		*/
#define IP_FW_F_KEEP_S	0x08000000	/* keep state	 			*/
#define IP_FW_F_CHECK_S	0x10000000	/* check state	 			*/

#define IP_FW_F_SME	0x20000000	/* source = me				*/
#define IP_FW_F_DME	0x40000000	/* destination = me			*/

#define IP_FW_F_MASK	0x7FFFFFFF	/* All possible flag bits mask		*/

/* 
 * Flags for the 'fw_ipflg' field, for comparing values of ip and its protocols.
 */
#define IP_FW_IF_TCPOPT	0x00000001      /* tcp options			*/
#define IP_FW_IF_TCPFLG	0x00000002      /* tcp flags			*/
#define IP_FW_IF_TCPSEQ	0x00000004      /* tcp sequence number		*/
#define IP_FW_IF_TCPACK	0x00000008      /* tcp acknowledgement number	*/
#define IP_FW_IF_TCPWIN	0x00000010      /* tcp window size		*/
#define	IP_FW_IF_TCPEST 0x00000020	/* established TCP connection	*/
#define	IP_FW_IF_TCPMSK	0x0000003f	/* mask of all tcp values	*/

#define IP_FW_IF_IPOPT	0x00000100	/* ip options			*/
#define IP_FW_IF_IPLEN	0x00000200	/* ip length			*/
#define IP_FW_IF_IPID	0x00000400	/* ip identification		*/
#define IP_FW_IF_IPTOS	0x00000800	/* ip type of service		*/
#define IP_FW_IF_IPTTL	0x00001000	/* ip time to live		*/
#define IP_FW_IF_IPVER	0x00002000	/* ip version			*/
#define IP_FW_IF_IPMSK	0x00003f00	/* mask of all ip values	*/

#define IP_FW_IF_MSK	0x0000ffff	/* All possible 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 IF_FW_F_VIAHACK	(IP_FW_F_IN|IP_FW_F_OUT|IP_FW_F_IIFACE|IP_FW_F_OIFACE)

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

/*
 * Definitions for IP option names.
 */
#define IP_FW_IPOPT_LSRR	0x01
#define IP_FW_IPOPT_SSRR	0x02
#define IP_FW_IPOPT_RR		0x04
#define IP_FW_IPOPT_TS		0x08

/*
 * Definitions for TCP option names.
 */
#define IP_FW_TCPOPT_MSS	0x01
#define IP_FW_TCPOPT_WINDOW	0x02
#define IP_FW_TCPOPT_SACK	0x04
#define IP_FW_TCPOPT_TS		0x08
#define IP_FW_TCPOPT_CC		0x10

/*
 * Definitions for TCP flags.
 */
#define IP_FW_TCPF_FIN		TH_FIN
#define IP_FW_TCPF_SYN		TH_SYN
#define IP_FW_TCPF_RST		TH_RST
#define IP_FW_TCPF_PSH		TH_PUSH
#define IP_FW_TCPF_ACK		TH_ACK
#define IP_FW_TCPF_URG		TH_URG

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

#define IP_FW_PORT_DYNT_FLAG	0x10000
#define IP_FW_PORT_TEE_FLAG	0x20000
#define IP_FW_PORT_DENY_FLAG	0x40000

/*
 * Function definitions.
 */
void ip_fw_init __P((void));

/* Firewall hooks */
struct ip;
struct sockopt;
typedef	int ip_fw_chk_t __P((struct ip **, int, struct ifnet *, u_int16_t *,
	     struct mbuf **, struct ip_fw_chain **, struct sockaddr_in **));
typedef	int ip_fw_ctl_t __P((struct sockopt *));
extern	ip_fw_chk_t *ip_fw_chk_ptr;
extern	ip_fw_ctl_t *ip_fw_ctl_ptr;
extern int fw_one_pass;
extern int fw_enable;
extern struct ipfw_flow_id last_pkt ;
#endif /* _KERNEL */

#endif /* _IP_FW_H */