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 1.28 1997/08/08 14:36:29 alex Exp $ 15 */ 16 17 #ifndef _IP_FW_H 18 #define _IP_FW_H 19 20 #include <net/if.h> 21 22 /* 23 * This union structure identifies an interface, either explicitly 24 * by name or implicitly by IP address. The flags IP_FW_F_IIFNAME 25 * and IP_FW_F_OIFNAME say how to interpret this structure. An 26 * interface unit number of -1 matches any unit number, while an 27 * IP address of 0.0.0.0 indicates matches any interface. 28 * 29 * The receive and transmit interfaces are only compared against the 30 * the packet if the corresponding bit (IP_FW_F_IIFACE or IP_FW_F_OIFACE) 31 * is set. Note some packets lack a receive or transmit interface 32 * (in which case the missing "interface" never matches). 33 */ 34 35 union ip_fw_if { 36 struct in_addr fu_via_ip; /* Specified by IP address */ 37 struct { /* Specified by interface name */ 38 #define FW_IFNLEN IFNAMSIZ 39 char name[FW_IFNLEN]; 40 short unit; /* -1 means match any unit */ 41 } fu_via_if; 42 }; 43 44 /* 45 * Format of an IP firewall descriptor 46 * 47 * fw_src, fw_dst, fw_smsk, fw_dmsk are always stored in network byte order. 48 * fw_flg and fw_n*p are stored in host byte order (of course). 49 * Port numbers are stored in HOST byte order. 50 * Warning: setsockopt() will fail if sizeof(struct ip_fw) > MLEN (108) 51 */ 52 53 struct ip_fw { 54 u_long fw_pcnt,fw_bcnt; /* Packet and byte counters */ 55 struct in_addr fw_src, fw_dst; /* Source and destination IP addr */ 56 struct in_addr fw_smsk, fw_dmsk; /* Mask for src and dest IP addr */ 57 u_short fw_number; /* Rule number */ 58 u_short fw_flg; /* Flags word */ 59 #define IP_FW_MAX_PORTS 10 /* A reasonable maximum */ 60 u_short fw_pts[IP_FW_MAX_PORTS]; /* Array of port numbers to match */ 61 u_char fw_ipopt,fw_ipnopt; /* IP options set/unset */ 62 u_char fw_tcpf,fw_tcpnf; /* TCP flags set/unset */ 63 #define IP_FW_ICMPTYPES_DIM (32 / (sizeof(unsigned) * 8)) 64 unsigned fw_icmptypes[IP_FW_ICMPTYPES_DIM]; /* ICMP types bitmap */ 65 long timestamp; /* timestamp (tv_sec) of last match */ 66 union ip_fw_if fw_in_if, fw_out_if; /* Incoming and outgoing interfaces */ 67 union { 68 u_short fu_divert_port; /* Divert/tee port (options IPDIVERT) */ 69 u_short fu_skipto_rule; /* SKIPTO command rule number */ 70 u_short fu_reject_code; /* REJECT response code */ 71 } fw_un; 72 u_char fw_prot; /* IP protocol */ 73 u_char fw_nports; /* N'of src ports and # of dst ports */ 74 /* in ports array (dst ports follow */ 75 /* src ports; max of 10 ports in all; */ 76 /* count of 0 means match all ports) */ 77 }; 78 79 #define IP_FW_GETNSRCP(rule) ((rule)->fw_nports & 0x0f) 80 #define IP_FW_SETNSRCP(rule, n) do { \ 81 (rule)->fw_nports &= ~0x0f; \ 82 (rule)->fw_nports |= (n); \ 83 } while (0) 84 #define IP_FW_GETNDSTP(rule) ((rule)->fw_nports >> 4) 85 #define IP_FW_SETNDSTP(rule, n) do { \ 86 (rule)->fw_nports &= ~0xf0; \ 87 (rule)->fw_nports |= (n) << 4;\ 88 } while (0) 89 90 #define fw_divert_port fw_un.fu_divert_port 91 #define fw_skipto_rule fw_un.fu_skipto_rule 92 #define fw_reject_code fw_un.fu_reject_code 93 94 struct ip_fw_chain { 95 LIST_ENTRY(ip_fw_chain) chain; 96 struct ip_fw *rule; 97 }; 98 99 /* 100 * Values for "flags" field . 101 */ 102 #define IP_FW_F_IN 0x0001 /* Check inbound packets */ 103 #define IP_FW_F_OUT 0x0002 /* Check outbound packets */ 104 #define IP_FW_F_IIFACE 0x0004 /* Apply inbound interface test */ 105 #define IP_FW_F_OIFACE 0x0008 /* Apply outbound interface test */ 106 107 #define IP_FW_F_COMMAND 0x0070 /* Mask for type of chain entry: */ 108 #define IP_FW_F_DENY 0x0000 /* This is a deny rule */ 109 #define IP_FW_F_REJECT 0x0010 /* Deny and send a response packet */ 110 #define IP_FW_F_ACCEPT 0x0020 /* This is an accept rule */ 111 #define IP_FW_F_COUNT 0x0030 /* This is a count rule */ 112 #define IP_FW_F_DIVERT 0x0040 /* This is a divert rule */ 113 #define IP_FW_F_TEE 0x0050 /* This is a tee rule */ 114 #define IP_FW_F_SKIPTO 0x0060 /* This is a skipto rule */ 115 116 #define IP_FW_F_PRN 0x0080 /* Print if this rule matches */ 117 118 #define IP_FW_F_SRNG 0x0100 /* The first two src ports are a min * 119 * and max range (stored in host byte * 120 * order). */ 121 122 #define IP_FW_F_DRNG 0x0200 /* The first two dst ports are a min * 123 * and max range (stored in host byte * 124 * order). */ 125 126 #define IP_FW_F_IIFNAME 0x0400 /* In interface by name/unit (not IP) */ 127 #define IP_FW_F_OIFNAME 0x0800 /* Out interface by name/unit (not IP) */ 128 129 #define IP_FW_F_INVSRC 0x1000 /* Invert sense of src check */ 130 #define IP_FW_F_INVDST 0x2000 /* Invert sense of dst check */ 131 132 #define IP_FW_F_FRAG 0x4000 /* Fragment */ 133 134 #define IP_FW_F_ICMPBIT 0x8000 /* ICMP type bitmap is valid */ 135 136 #define IP_FW_F_MASK 0xFFFF /* All possible flag bits mask */ 137 138 /* 139 * For backwards compatibility with rules specifying "via iface" but 140 * not restricted to only "in" or "out" packets, we define this combination 141 * of bits to represent this configuration. 142 */ 143 144 #define IF_FW_F_VIAHACK (IP_FW_F_IN|IP_FW_F_OUT|IP_FW_F_IIFACE|IP_FW_F_OIFACE) 145 146 /* 147 * Definitions for REJECT response codes. 148 * Values less than 256 correspond to ICMP unreachable codes. 149 */ 150 #define IP_FW_REJECT_RST 0x0100 /* TCP packets: send RST */ 151 152 /* 153 * Definitions for IP option names. 154 */ 155 #define IP_FW_IPOPT_LSRR 0x01 156 #define IP_FW_IPOPT_SSRR 0x02 157 #define IP_FW_IPOPT_RR 0x04 158 #define IP_FW_IPOPT_TS 0x08 159 160 /* 161 * Definitions for TCP flags. 162 */ 163 #define IP_FW_TCPF_FIN TH_FIN 164 #define IP_FW_TCPF_SYN TH_SYN 165 #define IP_FW_TCPF_RST TH_RST 166 #define IP_FW_TCPF_PSH TH_PUSH 167 #define IP_FW_TCPF_ACK TH_ACK 168 #define IP_FW_TCPF_URG TH_URG 169 #define IP_FW_TCPF_ESTAB 0x40 170 171 /* 172 * Main firewall chains definitions and global var's definitions. 173 */ 174 #ifdef KERNEL 175 176 /* 177 * Function definitions. 178 */ 179 void ip_fw_init __P((void)); 180 181 #endif /* KERNEL */ 182 183 #endif /* _IP_FW_H */ 184