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 * $FreeBSD$ 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 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 */ 51 52 struct ip_fw { 53 u_int64_t fw_pcnt,fw_bcnt; /* Packet and byte counters */ 54 struct in_addr fw_src, fw_dst; /* Source and destination IP addr */ 55 struct in_addr fw_smsk, fw_dmsk; /* Mask for src and dest IP addr */ 56 u_short fw_number; /* Rule number */ 57 u_int fw_flg; /* Operational Flags word */ 58 #define IP_FW_MAX_PORTS 10 /* A reasonable maximum */ 59 union { 60 u_short fw_pts[IP_FW_MAX_PORTS]; /* Array of port numbers to match */ 61 #define IP_FW_ICMPTYPES_MAX 128 62 #define IP_FW_ICMPTYPES_DIM (IP_FW_ICMPTYPES_MAX / (sizeof(unsigned) * 8)) 63 unsigned fw_icmptypes[IP_FW_ICMPTYPES_DIM]; /* ICMP types bitmap */ 64 } fw_uar; 65 u_int fw_ipflg; /* IP flags word */ 66 u_char fw_ipopt,fw_ipnopt; /* IP options set/unset */ 67 u_short fw_iplen, fw_ipid; /* IP length, identification */ 68 u_char fw_iptos, fw_ipntos; /* IP type of service set/unset */ 69 u_char fw_ipttl; /* IP time to live */ 70 u_int fw_ipver:4; /* IP version */ 71 u_char fw_tcpopt,fw_tcpnopt; /* TCP options set/unset */ 72 u_char fw_tcpf,fw_tcpnf; /* TCP flags set/unset */ 73 u_int32_t fw_tcpseq, fw_tcpack; /* TCP sequence and acknowledgement */ 74 u_short fw_tcpwin; /* TCP window size */ 75 long timestamp; /* timestamp (tv_sec) of last match */ 76 union ip_fw_if fw_in_if, fw_out_if; /* Incoming and outgoing interfaces */ 77 union { 78 u_short fu_divert_port; /* Divert/tee port (options IPDIVERT) */ 79 u_short fu_pipe_nr; /* queue number (option DUMMYNET) */ 80 u_short fu_skipto_rule; /* SKIPTO command rule number */ 81 u_short fu_reject_code; /* REJECT response code */ 82 struct sockaddr_in fu_fwd_ip; 83 } fw_un; 84 u_char fw_prot; /* IP protocol */ 85 /* 86 * N'of src ports and # of dst ports in ports array (dst ports 87 * follow src ports; max of 10 ports in all; count of 0 means 88 * match all ports) 89 */ 90 u_char fw_nports; 91 void *pipe_ptr; /* flow_set ptr for dummynet pipe */ 92 void *next_rule_ptr ; /* next rule in case of match */ 93 uid_t fw_uid; /* uid to match */ 94 gid_t fw_gid; /* gid to match */ 95 int fw_logamount; /* amount to log */ 96 u_int64_t fw_loghighest; /* highest number packet to log */ 97 }; 98 99 /* 100 * extended ipfw structure... some fields in the original struct 101 * can be used to pass parameters up/down, namely pointers 102 * void *pipe_ptr 103 * void *next_rule_ptr 104 * some others can be used to pass parameters down, namely counters etc. 105 * u_int64_t fw_pcnt,fw_bcnt; 106 * long timestamp; 107 */ 108 109 struct ip_fw_ext { /* extended structure */ 110 struct ip_fw rule; /* must be at offset 0 */ 111 long dont_match_prob; /* 0x7fffffff means 1.0, always fail */ 112 u_int dyn_type; /* type for dynamic rule */ 113 }; 114 115 #define IP_FW_GETNSRCP(rule) ((rule)->fw_nports & 0x0f) 116 #define IP_FW_SETNSRCP(rule, n) do { \ 117 (rule)->fw_nports &= ~0x0f; \ 118 (rule)->fw_nports |= (n); \ 119 } while (0) 120 #define IP_FW_GETNDSTP(rule) ((rule)->fw_nports >> 4) 121 #define IP_FW_SETNDSTP(rule, n) do { \ 122 (rule)->fw_nports &= ~0xf0; \ 123 (rule)->fw_nports |= (n) << 4;\ 124 } while (0) 125 126 #define fw_divert_port fw_un.fu_divert_port 127 #define fw_skipto_rule fw_un.fu_skipto_rule 128 #define fw_reject_code fw_un.fu_reject_code 129 #define fw_pipe_nr fw_un.fu_pipe_nr 130 #define fw_fwd_ip fw_un.fu_fwd_ip 131 132 struct ip_fw_chain { 133 LIST_ENTRY(ip_fw_chain) chain; 134 struct ip_fw *rule; 135 }; 136 137 /* 138 * Flow mask/flow id for each queue. 139 */ 140 struct ipfw_flow_id { 141 u_int32_t dst_ip, src_ip ; 142 u_int16_t dst_port, src_port ; 143 u_int8_t proto ; 144 u_int8_t flags ; /* protocol-specific flags */ 145 } ; 146 147 /* 148 * dynamic ipfw rule 149 */ 150 struct ipfw_dyn_rule { 151 struct ipfw_dyn_rule *next ; 152 153 struct ipfw_flow_id id ; 154 struct ipfw_flow_id mask ; 155 struct ip_fw_chain *chain ; /* pointer to parent rule */ 156 u_int32_t type ; /* rule type */ 157 u_int32_t expire ; /* expire time */ 158 u_int64_t pcnt, bcnt; /* match counters */ 159 u_int32_t bucket ; /* which bucket in hash table */ 160 u_int32_t state ; /* state of this rule (typ. a */ 161 /* combination of TCP flags) */ 162 } ; 163 164 /* 165 * Values for "flags" field . 166 */ 167 #define IP_FW_F_COMMAND 0x000000ff /* Mask for type of chain entry: */ 168 #define IP_FW_F_DENY 0x00000000 /* This is a deny rule */ 169 #define IP_FW_F_REJECT 0x00000001 /* Deny and send a response packet */ 170 #define IP_FW_F_ACCEPT 0x00000002 /* This is an accept rule */ 171 #define IP_FW_F_COUNT 0x00000003 /* This is a count rule */ 172 #define IP_FW_F_DIVERT 0x00000004 /* This is a divert rule */ 173 #define IP_FW_F_TEE 0x00000005 /* This is a tee rule */ 174 #define IP_FW_F_SKIPTO 0x00000006 /* This is a skipto rule */ 175 #define IP_FW_F_FWD 0x00000007 /* This is a "change forwarding address" rule */ 176 #define IP_FW_F_PIPE 0x00000008 /* This is a dummynet rule */ 177 #define IP_FW_F_QUEUE 0x00000009 /* This is a dummynet queue */ 178 179 #define IP_FW_F_IN 0x00000100 /* Check inbound packets */ 180 #define IP_FW_F_OUT 0x00000200 /* Check outbound packets */ 181 #define IP_FW_F_IIFACE 0x00000400 /* Apply inbound interface test */ 182 #define IP_FW_F_OIFACE 0x00000800 /* Apply outbound interface test */ 183 184 #define IP_FW_F_PRN 0x00001000 /* Print if this rule matches */ 185 186 #define IP_FW_F_SRNG 0x00002000 /* The first two src ports are a min * 187 * and max range (stored in host byte * 188 * order). */ 189 190 #define IP_FW_F_DRNG 0x00004000 /* The first two dst ports are a min * 191 * and max range (stored in host byte * 192 * order). */ 193 194 #define IP_FW_F_FRAG 0x00008000 /* Fragment */ 195 196 #define IP_FW_F_IIFNAME 0x00010000 /* In interface by name/unit (not IP) */ 197 #define IP_FW_F_OIFNAME 0x00020000 /* Out interface by name/unit (not IP) */ 198 199 #define IP_FW_F_INVSRC 0x00040000 /* Invert sense of src check */ 200 #define IP_FW_F_INVDST 0x00080000 /* Invert sense of dst check */ 201 202 #define IP_FW_F_ICMPBIT 0x00100000 /* ICMP type bitmap is valid */ 203 204 #define IP_FW_F_UID 0x00200000 /* filter by uid */ 205 206 #define IP_FW_F_GID 0x00400000 /* filter by gid */ 207 208 #define IP_FW_F_RND_MATCH 0x00800000 /* probabilistic rule match */ 209 #define IP_FW_F_SMSK 0x01000000 /* src-port + mask */ 210 #define IP_FW_F_DMSK 0x02000000 /* dst-port + mask */ 211 #define IP_FW_BRIDGED 0x04000000 /* only match bridged packets */ 212 #define IP_FW_F_KEEP_S 0x08000000 /* keep state */ 213 #define IP_FW_F_CHECK_S 0x10000000 /* check state */ 214 215 #define IP_FW_F_MASK 0x1FFFFFFF /* All possible flag bits mask */ 216 217 /* 218 * Flags for the 'fw_ipflg' field, for comparing values of ip and its protocols. 219 */ 220 #define IP_FW_IF_TCPOPT 0x00000001 /* tcp options */ 221 #define IP_FW_IF_TCPFLG 0x00000002 /* tcp flags */ 222 #define IP_FW_IF_TCPSEQ 0x00000004 /* tcp sequence number */ 223 #define IP_FW_IF_TCPACK 0x00000008 /* tcp acknowledgement number */ 224 #define IP_FW_IF_TCPWIN 0x00000010 /* tcp window size */ 225 #define IP_FW_IF_TCPMSK 0x0000001f /* mask of all tcp values */ 226 227 #define IP_FW_IF_IPOPT 0x00000100 /* ip options */ 228 #define IP_FW_IF_IPLEN 0x00000200 /* ip length */ 229 #define IP_FW_IF_IPID 0x00000400 /* ip identification */ 230 #define IP_FW_IF_IPTOS 0x00000800 /* ip type of service */ 231 #define IP_FW_IF_IPTTL 0x00001000 /* ip time to live */ 232 #define IP_FW_IF_IPVER 0x00002000 /* ip version */ 233 #define IP_FW_IF_IPMSK 0x00003f00 /* mask of all ip values */ 234 235 #define IP_FW_IF_MSK 0x0000ffff /* All possible bits mask */ 236 237 /* 238 * For backwards compatibility with rules specifying "via iface" but 239 * not restricted to only "in" or "out" packets, we define this combination 240 * of bits to represent this configuration. 241 */ 242 243 #define IF_FW_F_VIAHACK (IP_FW_F_IN|IP_FW_F_OUT|IP_FW_F_IIFACE|IP_FW_F_OIFACE) 244 245 /* 246 * Definitions for REJECT response codes. 247 * Values less than 256 correspond to ICMP unreachable codes. 248 */ 249 #define IP_FW_REJECT_RST 0x0100 /* TCP packets: send RST */ 250 251 /* 252 * Definitions for IP option names. 253 */ 254 #define IP_FW_IPOPT_LSRR 0x01 255 #define IP_FW_IPOPT_SSRR 0x02 256 #define IP_FW_IPOPT_RR 0x04 257 #define IP_FW_IPOPT_TS 0x08 258 259 /* 260 * Definitions for TCP option names. 261 */ 262 #define IP_FW_TCPOPT_MSS 0x01 263 #define IP_FW_TCPOPT_WINDOW 0x02 264 #define IP_FW_TCPOPT_SACK 0x04 265 #define IP_FW_TCPOPT_TS 0x08 266 #define IP_FW_TCPOPT_CC 0x10 267 268 /* 269 * Definitions for TCP flags. 270 */ 271 #define IP_FW_TCPF_FIN TH_FIN 272 #define IP_FW_TCPF_SYN TH_SYN 273 #define IP_FW_TCPF_RST TH_RST 274 #define IP_FW_TCPF_PSH TH_PUSH 275 #define IP_FW_TCPF_ACK TH_ACK 276 #define IP_FW_TCPF_URG TH_URG 277 #define IP_FW_TCPF_ESTAB 0x40 278 279 /* 280 * Main firewall chains definitions and global var's definitions. 281 */ 282 #ifdef _KERNEL 283 284 #define IP_FW_PORT_DYNT_FLAG 0x10000 285 #define IP_FW_PORT_TEE_FLAG 0x20000 286 287 /* 288 * Function definitions. 289 */ 290 void ip_fw_init __P((void)); 291 292 /* Firewall hooks */ 293 struct ip; 294 struct sockopt; 295 typedef int ip_fw_chk_t __P((struct ip **, int, struct ifnet *, u_int16_t *, 296 struct mbuf **, struct ip_fw_chain **, struct sockaddr_in **)); 297 typedef int ip_fw_ctl_t __P((struct sockopt *)); 298 extern ip_fw_chk_t *ip_fw_chk_ptr; 299 extern ip_fw_ctl_t *ip_fw_ctl_ptr; 300 extern int fw_one_pass; 301 extern int fw_enable; 302 extern struct ipfw_flow_id last_pkt ; 303 #endif /* _KERNEL */ 304 305 #endif /* _IP_FW_H */ 306