ip_fw.h revision 55205
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 * $FreeBSD: head/sys/netinet/ip_fw.h 55205 1999-12-29 04:46:21Z peter $ 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 35union ip_fw_if { 36 struct in_addr fu_via_ip; /* Specified by IP address */ 37 struct { /* Specified by interface name */ 38#define FW_IFNLEN 10 /* need room ! was 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 53struct 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_pipe_nr; /* pipe number (option DUMMYNET) */ 73 u_short fu_skipto_rule; /* SKIPTO command rule number */ 74 u_short fu_reject_code; /* REJECT response code */ 75 struct sockaddr_in fu_fwd_ip; 76 } fw_un; 77 u_char fw_prot; /* IP protocol */ 78 /* 79 * N'of src ports and # of dst ports in ports array (dst ports 80 * follow src ports; max of 10 ports in all; count of 0 means 81 * match all ports) 82 */ 83 u_char fw_nports; 84 void *pipe_ptr; /* Pipe ptr in case of dummynet pipe */ 85 void *next_rule_ptr ; /* next rule in case of match */ 86 uid_t fw_uid; /* uid to match */ 87 gid_t fw_gid; /* gid to match */ 88 int fw_logamount; /* amount to log */ 89 u_int64_t fw_loghighest; /* highest number packet to log */ 90}; 91 92/* 93 * extended ipfw structure... some fields in the original struct 94 * can be used to pass parameters up/down, namely pointers 95 * void *pipe_ptr 96 * void *next_rule_ptr 97 * some others can be used to pass parameters down, namely counters etc. 98 * u_int64_t fw_pcnt,fw_bcnt; 99 * long timestamp; 100 */ 101 102struct ip_fw_ext { /* extended structure */ 103 struct ip_fw rule; /* must be at offset 0 */ 104 long dont_match_prob; /* 0x7fffffff means 1.0, always fail */ 105 u_int param1; /* unused at the moment */ 106}; 107 108#define IP_FW_GETNSRCP(rule) ((rule)->fw_nports & 0x0f) 109#define IP_FW_SETNSRCP(rule, n) do { \ 110 (rule)->fw_nports &= ~0x0f; \ 111 (rule)->fw_nports |= (n); \ 112 } while (0) 113#define IP_FW_GETNDSTP(rule) ((rule)->fw_nports >> 4) 114#define IP_FW_SETNDSTP(rule, n) do { \ 115 (rule)->fw_nports &= ~0xf0; \ 116 (rule)->fw_nports |= (n) << 4;\ 117 } while (0) 118 119#define fw_divert_port fw_un.fu_divert_port 120#define fw_skipto_rule fw_un.fu_skipto_rule 121#define fw_reject_code fw_un.fu_reject_code 122#define fw_pipe_nr fw_un.fu_pipe_nr 123#define fw_fwd_ip fw_un.fu_fwd_ip 124 125struct ip_fw_chain { 126 LIST_ENTRY(ip_fw_chain) chain; 127 struct ip_fw *rule; 128}; 129 130/* 131 * Values for "flags" field . 132 */ 133#define IP_FW_F_COMMAND 0x000000ff /* Mask for type of chain entry: */ 134#define IP_FW_F_DENY 0x00000000 /* This is a deny rule */ 135#define IP_FW_F_REJECT 0x00000001 /* Deny and send a response packet */ 136#define IP_FW_F_ACCEPT 0x00000002 /* This is an accept rule */ 137#define IP_FW_F_COUNT 0x00000003 /* This is a count rule */ 138#define IP_FW_F_DIVERT 0x00000004 /* This is a divert rule */ 139#define IP_FW_F_TEE 0x00000005 /* This is a tee rule */ 140#define IP_FW_F_SKIPTO 0x00000006 /* This is a skipto rule */ 141#define IP_FW_F_FWD 0x00000007 /* This is a "change forwarding address" rule */ 142#define IP_FW_F_PIPE 0x00000008 /* This is a dummynet rule */ 143 144#define IP_FW_F_IN 0x00000100 /* Check inbound packets */ 145#define IP_FW_F_OUT 0x00000200 /* Check outbound packets */ 146#define IP_FW_F_IIFACE 0x00000400 /* Apply inbound interface test */ 147#define IP_FW_F_OIFACE 0x00000800 /* Apply outbound interface test */ 148 149#define IP_FW_F_PRN 0x00001000 /* Print if this rule matches */ 150 151#define IP_FW_F_SRNG 0x00002000 /* The first two src ports are a min * 152 * and max range (stored in host byte * 153 * order). */ 154 155#define IP_FW_F_DRNG 0x00004000 /* The first two dst ports are a min * 156 * and max range (stored in host byte * 157 * order). */ 158 159#define IP_FW_F_FRAG 0x00008000 /* Fragment */ 160 161#define IP_FW_F_IIFNAME 0x00010000 /* In interface by name/unit (not IP) */ 162#define IP_FW_F_OIFNAME 0x00020000 /* Out interface by name/unit (not IP) */ 163 164#define IP_FW_F_INVSRC 0x00040000 /* Invert sense of src check */ 165#define IP_FW_F_INVDST 0x00080000 /* Invert sense of dst check */ 166 167#define IP_FW_F_ICMPBIT 0x00100000 /* ICMP type bitmap is valid */ 168 169#define IP_FW_F_UID 0x00200000 /* filter by uid */ 170 171#define IP_FW_F_GID 0x00400000 /* filter by gid */ 172 173#define IP_FW_F_RND_MATCH 0x00800000 /* probabilistic rule match */ 174 175#define IP_FW_F_MASK 0x00FFFFFF /* All possible flag bits mask */ 176 177/* 178 * For backwards compatibility with rules specifying "via iface" but 179 * not restricted to only "in" or "out" packets, we define this combination 180 * of bits to represent this configuration. 181 */ 182 183#define IF_FW_F_VIAHACK (IP_FW_F_IN|IP_FW_F_OUT|IP_FW_F_IIFACE|IP_FW_F_OIFACE) 184 185/* 186 * Definitions for REJECT response codes. 187 * Values less than 256 correspond to ICMP unreachable codes. 188 */ 189#define IP_FW_REJECT_RST 0x0100 /* TCP packets: send RST */ 190 191/* 192 * Definitions for IP option names. 193 */ 194#define IP_FW_IPOPT_LSRR 0x01 195#define IP_FW_IPOPT_SSRR 0x02 196#define IP_FW_IPOPT_RR 0x04 197#define IP_FW_IPOPT_TS 0x08 198 199/* 200 * Definitions for TCP flags. 201 */ 202#define IP_FW_TCPF_FIN TH_FIN 203#define IP_FW_TCPF_SYN TH_SYN 204#define IP_FW_TCPF_RST TH_RST 205#define IP_FW_TCPF_PSH TH_PUSH 206#define IP_FW_TCPF_ACK TH_ACK 207#define IP_FW_TCPF_URG TH_URG 208#define IP_FW_TCPF_ESTAB 0x40 209 210/* 211 * Main firewall chains definitions and global var's definitions. 212 */ 213#ifdef _KERNEL 214 215#define IP_FW_PORT_DYNT_FLAG 0x10000 216#define IP_FW_PORT_TEE_FLAG 0x20000 217 218/* 219 * Function definitions. 220 */ 221void ip_fw_init __P((void)); 222 223/* Firewall hooks */ 224struct ip; 225struct sockopt; 226typedef int ip_fw_chk_t __P((struct ip **, int, struct ifnet *, u_int16_t *, 227 struct mbuf **, struct ip_fw_chain **, struct sockaddr_in **)); 228typedef int ip_fw_ctl_t __P((struct sockopt *)); 229extern ip_fw_chk_t *ip_fw_chk_ptr; 230extern ip_fw_ctl_t *ip_fw_ctl_ptr; 231 232#endif /* _KERNEL */ 233 234#endif /* _IP_FW_H */ 235