/* * 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: ip_fw.h,v 1.1 1997/05/09 17:46:45 archie Exp $ */ #ifndef _IP_FW_H #define _IP_FW_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 6 /* To keep structure on 2^x boundary */ 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 (256 / (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 */