1 /* 2 * Copyright (c) 1993 Daniel Boulet 3 * Copyright (c) 1994 Ugen J.S.Antsilevich 4 * 5 * Redistribution and use in source forms, with and without modification, 6 * are permitted provided that this entire comment appears intact. 7 * 8 * Redistribution in binary form may occur without any restrictions. 9 * Obviously, it would be nice if you gave credit where credit is due 10 * but requiring it would be too onerous. 11 * 12 * This software is provided ``AS IS'' without any warranties of any kind. 13 * 14 * $Id: ip_fw.h,v 1.1 1997/05/09 17:46:45 archie Exp $ 15 */ 16 17 #ifndef _IP_FW_H 18 #define _IP_FW_H 19 20 /* 21 * This union structure identifies an interface, either explicitly 22 * by name or implicitly by IP address. The flags IP_FW_F_IIFNAME 23 * and IP_FW_F_OIFNAME say how to interpret this structure. An 24 * interface unit number of -1 matches any unit number, while an 25 * IP address of 0.0.0.0 indicates matches any interface. 26 * 27 * The receive and transmit interfaces are only compared against the 28 * the packet if the corresponding bit (IP_FW_F_IIFACE or IP_FW_F_OIFACE) 29 * is set. Note some packets lack a receive or transmit interface 30 * (in which case the missing "interface" never matches). 31 */ 32 33 union ip_fw_if { 34 struct in_addr fu_via_ip; /* Specified by IP address */ 35 struct { /* Specified by interface name */ 36 #define FW_IFNLEN 6 /* To keep structure on 2^x boundary */ 37 char name[FW_IFNLEN]; 38 short unit; /* -1 means match any unit */ 39 } fu_via_if; 40 }; 41 42 /* 43 * Format of an IP firewall descriptor 44 * 45 * fw_src, fw_dst, fw_smsk, fw_dmsk are always stored in network byte order. 46 * fw_flg and fw_n*p are stored in host byte order (of course). 47 * Port numbers are stored in HOST byte order. 48 * Warning: setsockopt() will fail if sizeof(struct ip_fw) > MLEN (108) 49 */ 50 51 struct ip_fw { 52 u_long fw_pcnt,fw_bcnt; /* Packet and byte counters */ 53 struct in_addr fw_src, fw_dst; /* Source and destination IP addr */ 54 struct in_addr fw_smsk, fw_dmsk; /* Mask for src and dest IP addr */ 55 u_short fw_number; /* Rule number */ 56 u_short fw_flg; /* Flags word */ 57 #define IP_FW_MAX_PORTS 10 /* A reasonable maximum */ 58 u_short fw_pts[IP_FW_MAX_PORTS]; /* Array of port numbers to match */ 59 u_char fw_ipopt,fw_ipnopt; /* IP options set/unset */ 60 u_char fw_tcpf,fw_tcpnf; /* TCP flags set/unset */ 61 #define IP_FW_ICMPTYPES_DIM (256 / (sizeof(unsigned) * 8)) 62 unsigned fw_icmptypes[IP_FW_ICMPTYPES_DIM]; /* ICMP types bitmap */ 63 long timestamp; /* timestamp (tv_sec) of last match */ 64 union ip_fw_if fw_in_if, fw_out_if; /* Incoming and outgoing interfaces */ 65 union { 66 u_short fu_divert_port; /* Divert/tee port (options IPDIVERT) */ 67 u_short fu_skipto_rule; /* SKIPTO command rule number */ 68 u_short fu_reject_code; /* REJECT response code */ 69 } fw_un; 70 u_char fw_prot; /* IP protocol */ 71 u_char fw_nports; /* N'of src ports and # of dst ports */ 72 /* in ports array (dst ports follow */ 73 /* src ports; max of 10 ports in all; */ 74 /* count of 0 means match all ports) */ 75 }; 76 77 #define IP_FW_GETNSRCP(rule) ((rule)->fw_nports & 0x0f) 78 #define IP_FW_SETNSRCP(rule, n) do { \ 79 (rule)->fw_nports &= ~0x0f; \ 80 (rule)->fw_nports |= (n); \ 81 } while (0) 82 #define IP_FW_GETNDSTP(rule) ((rule)->fw_nports >> 4) 83 #define IP_FW_SETNDSTP(rule, n) do { \ 84 (rule)->fw_nports &= ~0xf0; \ 85 (rule)->fw_nports |= (n) << 4;\ 86 } while (0) 87 88 #define fw_divert_port fw_un.fu_divert_port 89 #define fw_skipto_rule fw_un.fu_skipto_rule 90 #define fw_reject_code fw_un.fu_reject_code 91 92 struct ip_fw_chain { 93 LIST_ENTRY(ip_fw_chain) chain; 94 struct ip_fw *rule; 95 }; 96 97 /* 98 * Values for "flags" field . 99 */ 100 #define IP_FW_F_IN 0x0001 /* Check inbound packets */ 101 #define IP_FW_F_OUT 0x0002 /* Check outbound packets */ 102 #define IP_FW_F_IIFACE 0x0004 /* Apply inbound interface test */ 103 #define IP_FW_F_OIFACE 0x0008 /* Apply outbound interface test */ 104 105 #define IP_FW_F_COMMAND 0x0070 /* Mask for type of chain entry: */ 106 #define IP_FW_F_DENY 0x0000 /* This is a deny rule */ 107 #define IP_FW_F_REJECT 0x0010 /* Deny and send a response packet */ 108 #define IP_FW_F_ACCEPT 0x0020 /* This is an accept rule */ 109 #define IP_FW_F_COUNT 0x0030 /* This is a count rule */ 110 #define IP_FW_F_DIVERT 0x0040 /* This is a divert rule */ 111 #define IP_FW_F_TEE 0x0050 /* This is a tee rule */ 112 #define IP_FW_F_SKIPTO 0x0060 /* This is a skipto rule */ 113 114 #define IP_FW_F_PRN 0x0080 /* Print if this rule matches */ 115 116 #define IP_FW_F_SRNG 0x0100 /* The first two src ports are a min * 117 * and max range (stored in host byte * 118 * order). */ 119 120 #define IP_FW_F_DRNG 0x0200 /* The first two dst ports are a min * 121 * and max range (stored in host byte * 122 * order). */ 123 124 #define IP_FW_F_IIFNAME 0x0400 /* In interface by name/unit (not IP) */ 125 #define IP_FW_F_OIFNAME 0x0800 /* Out interface by name/unit (not IP) */ 126 127 #define IP_FW_F_INVSRC 0x1000 /* Invert sense of src check */ 128 #define IP_FW_F_INVDST 0x2000 /* Invert sense of dst check */ 129 130 #define IP_FW_F_FRAG 0x4000 /* Fragment */ 131 132 #define IP_FW_F_ICMPBIT 0x8000 /* ICMP type bitmap is valid */ 133 134 #define IP_FW_F_MASK 0xFFFF /* All possible flag bits mask */ 135 136 /* 137 * For backwards compatibility with rules specifying "via iface" but 138 * not restricted to only "in" or "out" packets, we define this combination 139 * of bits to represent this configuration. 140 */ 141 142 #define IF_FW_F_VIAHACK (IP_FW_F_IN|IP_FW_F_OUT|IP_FW_F_IIFACE|IP_FW_F_OIFACE) 143 144 /* 145 * Definitions for REJECT response codes. 146 * Values less than 256 correspond to ICMP unreachable codes. 147 */ 148 #define IP_FW_REJECT_RST 0x0100 /* TCP packets: send RST */ 149 150 /* 151 * Definitions for IP option names. 152 */ 153 #define IP_FW_IPOPT_LSRR 0x01 154 #define IP_FW_IPOPT_SSRR 0x02 155 #define IP_FW_IPOPT_RR 0x04 156 #define IP_FW_IPOPT_TS 0x08 157 158 /* 159 * Definitions for TCP flags. 160 */ 161 #define IP_FW_TCPF_FIN TH_FIN 162 #define IP_FW_TCPF_SYN TH_SYN 163 #define IP_FW_TCPF_RST TH_RST 164 #define IP_FW_TCPF_PSH TH_PUSH 165 #define IP_FW_TCPF_ACK TH_ACK 166 #define IP_FW_TCPF_URG TH_URG 167 #define IP_FW_TCPF_ESTAB 0x40 168 169 /* 170 * Main firewall chains definitions and global var's definitions. 171 */ 172 #ifdef KERNEL 173 174 /* 175 * Function definitions. 176 */ 177 void ip_fw_init(void); 178 179 #endif /* KERNEL */ 180 181 #endif /* _IP_FW_H */ 182