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/*
* 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
#include <sys/queue.h> /* LIST_ENTRY */
#include <net/if.h>
#include <netinet/in.h> /* struct in_addr */
/*
* 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 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 ip_fw {
u_long 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_short fw_flg; /* Flags word */
#define IP_FW_MAX_PORTS 10 /* A reasonable maximum */
u_short fw_pts[IP_FW_MAX_PORTS]; /* Array of port numbers to match */
u_char fw_ipopt,fw_ipnopt; /* IP options set/unset */
u_char fw_tcpf,fw_tcpnf; /* TCP flags set/unset */
#define IP_FW_ICMPTYPES_DIM (32 / (sizeof(unsigned) * 8))
unsigned fw_icmptypes[IP_FW_ICMPTYPES_DIM]; /* ICMP types bitmap */
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_skipto_rule; /* SKIPTO command rule number */
u_short fu_reject_code; /* REJECT response code */
} fw_un;
u_char fw_prot; /* IP 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 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
struct ip_fw_chain {
LIST_ENTRY(ip_fw_chain) chain;
struct ip_fw *rule;
};
/*
* Values for "flags" field .
*/
#define IP_FW_F_IN 0x0001 /* Check inbound packets */
#define IP_FW_F_OUT 0x0002 /* Check outbound packets */
#define IP_FW_F_IIFACE 0x0004 /* Apply inbound interface test */
#define IP_FW_F_OIFACE 0x0008 /* Apply outbound interface test */
#define IP_FW_F_COMMAND 0x0070 /* Mask for type of chain entry: */
#define IP_FW_F_DENY 0x0000 /* This is a deny rule */
#define IP_FW_F_REJECT 0x0010 /* Deny and send a response packet */
#define IP_FW_F_ACCEPT 0x0020 /* This is an accept rule */
#define IP_FW_F_COUNT 0x0030 /* This is a count rule */
#define IP_FW_F_DIVERT 0x0040 /* This is a divert rule */
#define IP_FW_F_TEE 0x0050 /* This is a tee rule */
#define IP_FW_F_SKIPTO 0x0060 /* This is a skipto rule */
#define IP_FW_F_PRN 0x0080 /* Print if this rule matches */
#define IP_FW_F_SRNG 0x0100 /* The first two src ports are a min *
* and max range (stored in host byte *
* order). */
#define IP_FW_F_DRNG 0x0200 /* The first two dst ports are a min *
* and max range (stored in host byte *
* order). */
#define IP_FW_F_IIFNAME 0x0400 /* In interface by name/unit (not IP) */
#define IP_FW_F_OIFNAME 0x0800 /* Out interface by name/unit (not IP) */
#define IP_FW_F_INVSRC 0x1000 /* Invert sense of src check */
#define IP_FW_F_INVDST 0x2000 /* Invert sense of dst check */
#define IP_FW_F_FRAG 0x4000 /* Fragment */
#define IP_FW_F_ICMPBIT 0x8000 /* ICMP type bitmap is valid */
#define IP_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 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 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
#define IP_FW_TCPF_ESTAB 0x40
/*
* Main firewall chains definitions and global var's definitions.
*/
#ifdef _KERNEL
/*
* Function definitions.
*/
void ip_fw_init(void);
#endif /* _KERNEL */
#endif /* _IP_FW_H */
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