ip_fw.h   [plain text]


/*
 * Copyright (c) 2008-2013 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 *
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/*
 * 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.
 *
 */

#ifndef _IP_FW_H
#define _IP_FW_H
#ifdef __APPLE_API_OBSOLETE

#include <sys/appleapiopts.h>

#ifdef IPFW2
#include <netinet/ip_fw2.h>
#else /* !IPFW2, good old ipfw */

#include <sys/queue.h>
#include <sys/types.h>          /* u_ types */

#define IP_FW_CURRENT_API_VERSION 20    /* Version of this API */


/*
 * 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_int32_t version;              /* Version of this structure.  Should always be */
	/* set to IP_FW_CURRENT_API_VERSION by clients. */
	void *context;                  /* Context that is usable by user processes to */
	/* identify this rule. */
	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;                   /* 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_char fw_tcpopt, fw_tcpnopt;   /* TCP options set/unset */
	u_char fw_tcpf, fw_tcpnf;       /* TCP flags set/unset */
	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 */
	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_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_TCPEST 0x00000020      /* established TCP connection */
#define IP_FW_IF_TCPMSK 0x00000020      /* mask of all TCP values */

/*
 * 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 BSD_KERNEL_PRIVATE

#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(void);

/* Firewall hooks */
struct ip;
struct sockopt;
typedef int ip_fw_chk_t(struct ip **, int, struct ifnet *, u_int16_t *,
    struct mbuf **, struct ip_fw_chain **, struct sockaddr_in **);
typedef int ip_fw_ctl_t(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;
#define IPFW_LOADED     (ip_fw_chk_ptr != NULL)
extern struct ipfw_flow_id last_pkt;
#endif /* BSD_KERNEL_PRIVATE */

#endif /* !IPFW2 */
#endif /* __APPLE_API_OBSOLETE */
#endif /* _IP_FW_H */