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 1.34 1998/08/23 03:07:14 wollman Exp $ 15 */ 16 17 #ifndef _IP_FW_H 18 #define _IP_FW_H 19 20 #include <sys/queue.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_int64_t 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_int fw_flg; /* Flags word */ 59 #define IP_FW_MAX_PORTS 10 /* A reasonable maximum */ 60 union { 61 u_short fw_pts[IP_FW_MAX_PORTS]; /* Array of port numbers to match */ 62 #define IP_FW_ICMPTYPES_MAX 128 63 #define IP_FW_ICMPTYPES_DIM (IP_FW_ICMPTYPES_MAX / (sizeof(unsigned) * 8)) 64 unsigned fw_icmptypes[IP_FW_ICMPTYPES_DIM]; /* ICMP types bitmap */ 65 } fw_uar; 66 u_char fw_ipopt,fw_ipnopt; /* IP options set/unset */ 67 u_char fw_tcpf,fw_tcpnf; /* TCP flags set/unset */ 68 long timestamp; /* timestamp (tv_sec) of last match */ 69 union ip_fw_if fw_in_if, fw_out_if; /* Incoming and outgoing interfaces */ 70 union { 71 u_short fu_divert_port; /* Divert/tee port (options IPDIVERT) */ 72 u_short fu_skipto_rule; /* SKIPTO command rule number */ 73 u_short fu_reject_code; /* REJECT response code */ 74 struct sockaddr_in fu_fwd_ip; 75 } fw_un; 76 u_char fw_prot; /* IP protocol */ 77 u_char fw_nports; /* N'of src ports and # of dst ports */ 78 /* in ports array (dst ports follow */ 79 /* src ports; max of 10 ports in all; */ 80 /* count of 0 means match all ports) */ 81 }; 82 83 #define IP_FW_GETNSRCP(rule) ((rule)->fw_nports & 0x0f) 84 #define IP_FW_SETNSRCP(rule, n) do { \ 85 (rule)->fw_nports &= ~0x0f; \ 86 (rule)->fw_nports |= (n); \ 87 } while (0) 88 #define IP_FW_GETNDSTP(rule) ((rule)->fw_nports >> 4) 89 #define IP_FW_SETNDSTP(rule, n) do { \ 90 (rule)->fw_nports &= ~0xf0; \ 91 (rule)->fw_nports |= (n) << 4;\ 92 } while (0) 93 94 #define fw_divert_port fw_un.fu_divert_port 95 #define fw_skipto_rule fw_un.fu_skipto_rule 96 #define fw_reject_code fw_un.fu_reject_code 97 #define fw_fwd_ip fw_un.fu_fwd_ip 98 99 struct ip_fw_chain { 100 LIST_ENTRY(ip_fw_chain) chain; 101 struct ip_fw *rule; 102 }; 103 104 /* 105 * Values for "flags" field . 106 */ 107 #define IP_FW_F_COMMAND 0x000000ff /* Mask for type of chain entry: */ 108 #define IP_FW_F_DENY 0x00000000 /* This is a deny rule */ 109 #define IP_FW_F_REJECT 0x00000001 /* Deny and send a response packet */ 110 #define IP_FW_F_ACCEPT 0x00000002 /* This is an accept rule */ 111 #define IP_FW_F_COUNT 0x00000003 /* This is a count rule */ 112 #define IP_FW_F_DIVERT 0x00000004 /* This is a divert rule */ 113 #define IP_FW_F_TEE 0x00000005 /* This is a tee rule */ 114 #define IP_FW_F_SKIPTO 0x00000006 /* This is a skipto rule */ 115 #define IP_FW_F_FWD 0x00000007 /* This is a "change forwarding address" rule */ 116 117 #define IP_FW_F_IN 0x00000100 /* Check inbound packets */ 118 #define IP_FW_F_OUT 0x00000200 /* Check outbound packets */ 119 #define IP_FW_F_IIFACE 0x00000400 /* Apply inbound interface test */ 120 #define IP_FW_F_OIFACE 0x00000800 /* Apply outbound interface test */ 121 122 #define IP_FW_F_PRN 0x00001000 /* Print if this rule matches */ 123 124 #define IP_FW_F_SRNG 0x00002000 /* The first two src ports are a min * 125 * and max range (stored in host byte * 126 * order). */ 127 128 #define IP_FW_F_DRNG 0x00004000 /* The first two dst ports are a min * 129 * and max range (stored in host byte * 130 * order). */ 131 132 #define IP_FW_F_FRAG 0x00008000 /* Fragment */ 133 134 #define IP_FW_F_IIFNAME 0x00010000 /* In interface by name/unit (not IP) */ 135 #define IP_FW_F_OIFNAME 0x00020000 /* Out interface by name/unit (not IP) */ 136 137 #define IP_FW_F_INVSRC 0x00040000 /* Invert sense of src check */ 138 #define IP_FW_F_INVDST 0x00080000 /* Invert sense of dst check */ 139 140 #define IP_FW_F_ICMPBIT 0x00100000 /* ICMP type bitmap is valid */ 141 142 #define IP_FW_F_MASK 0x001FFFFF /* All possible flag bits mask */ 143 144 /* 145 * For backwards compatibility with rules specifying "via iface" but 146 * not restricted to only "in" or "out" packets, we define this combination 147 * of bits to represent this configuration. 148 */ 149 150 #define IF_FW_F_VIAHACK (IP_FW_F_IN|IP_FW_F_OUT|IP_FW_F_IIFACE|IP_FW_F_OIFACE) 151 152 /* 153 * Definitions for REJECT response codes. 154 * Values less than 256 correspond to ICMP unreachable codes. 155 */ 156 #define IP_FW_REJECT_RST 0x0100 /* TCP packets: send RST */ 157 158 /* 159 * Definitions for IP option names. 160 */ 161 #define IP_FW_IPOPT_LSRR 0x01 162 #define IP_FW_IPOPT_SSRR 0x02 163 #define IP_FW_IPOPT_RR 0x04 164 #define IP_FW_IPOPT_TS 0x08 165 166 /* 167 * Definitions for TCP flags. 168 */ 169 #define IP_FW_TCPF_FIN TH_FIN 170 #define IP_FW_TCPF_SYN TH_SYN 171 #define IP_FW_TCPF_RST TH_RST 172 #define IP_FW_TCPF_PSH TH_PUSH 173 #define IP_FW_TCPF_ACK TH_ACK 174 #define IP_FW_TCPF_URG TH_URG 175 #define IP_FW_TCPF_ESTAB 0x40 176 177 /* 178 * Main firewall chains definitions and global var's definitions. 179 */ 180 #ifdef KERNEL 181 182 /* 183 * Function definitions. 184 */ 185 void ip_fw_init __P((void)); 186 187 /* Firewall hooks */ 188 struct ip; 189 struct sockopt; 190 typedef int ip_fw_chk_t __P((struct ip **, int, struct ifnet *, u_int16_t *, 191 struct mbuf **, struct sockaddr_in **)); 192 typedef int ip_fw_ctl_t __P((struct sockopt *)); 193 extern ip_fw_chk_t *ip_fw_chk_ptr; 194 extern ip_fw_ctl_t *ip_fw_ctl_ptr; 195 196 /* IP NAT hooks */ 197 typedef int ip_nat_t __P((struct ip **, struct mbuf **, struct ifnet *, int)); 198 typedef int ip_nat_ctl_t __P((struct sockopt *)); 199 extern ip_nat_t *ip_nat_ptr; 200 extern ip_nat_ctl_t *ip_nat_ctl_ptr; 201 #define IP_NAT_IN 0x00000001 202 #define IP_NAT_OUT 0x00000002 203 204 #endif /* KERNEL */ 205 206 #endif /* _IP_FW_H */ 207