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 * 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_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 */ 101 102 struct 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 dyn_type; /* type for dynamic rule */ 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 124 125 struct ip_fw_chain { 126 LIST_ENTRY(ip_fw_chain) chain; 127 struct ip_fw *rule; 128 }; 129 130 /* 131 * Flow mask/flow id for each queue. 132 */ 133 struct ipfw_flow_id { 134 u_int32_t dst_ip, src_ip ; 135 u_int16_t dst_port, src_port ; 136 u_int8_t proto ; 137 u_int8_t flags ; /* protocol-specific flags */ 138 } ; 139 140 /* 141 * dynamic ipfw rule 142 */ 143 struct ipfw_dyn_rule { 144 struct ipfw_dyn_rule *next ; 145 146 struct ipfw_flow_id id ; 147 struct ipfw_flow_id mask ; 148 struct ip_fw_chain *chain ; /* pointer to parent rule */ 149 u_int32_t type ; /* rule type */ 150 u_int32_t expire ; /* expire time */ 151 u_int64_t pcnt, bcnt; /* match counters */ 152 u_int32_t bucket ; /* which bucket in hash table */ 153 u_int32_t state ; /* state of this rule (typ. a */ 154 /* combination of TCP flags) */ 155 } ; 156 157 /* 158 * Values for "flags" field . 159 */ 160 #define IP_FW_F_COMMAND 0x000000ff /* Mask for type of chain entry: */ 161 #define IP_FW_F_DENY 0x00000000 /* This is a deny rule */ 162 #define IP_FW_F_REJECT 0x00000001 /* Deny and send a response packet */ 163 #define IP_FW_F_ACCEPT 0x00000002 /* This is an accept rule */ 164 #define IP_FW_F_COUNT 0x00000003 /* This is a count rule */ 165 #define IP_FW_F_DIVERT 0x00000004 /* This is a divert rule */ 166 #define IP_FW_F_TEE 0x00000005 /* This is a tee rule */ 167 #define IP_FW_F_SKIPTO 0x00000006 /* This is a skipto rule */ 168 #define IP_FW_F_FWD 0x00000007 /* This is a "change forwarding address" rule */ 169 #define IP_FW_F_PIPE 0x00000008 /* This is a dummynet rule */ 170 171 #define IP_FW_F_IN 0x00000100 /* Check inbound packets */ 172 #define IP_FW_F_OUT 0x00000200 /* Check outbound packets */ 173 #define IP_FW_F_IIFACE 0x00000400 /* Apply inbound interface test */ 174 #define IP_FW_F_OIFACE 0x00000800 /* Apply outbound interface test */ 175 176 #define IP_FW_F_PRN 0x00001000 /* Print if this rule matches */ 177 178 #define IP_FW_F_SRNG 0x00002000 /* The first two src ports are a min * 179 * and max range (stored in host byte * 180 * order). */ 181 182 #define IP_FW_F_DRNG 0x00004000 /* The first two dst ports are a min * 183 * and max range (stored in host byte * 184 * order). */ 185 186 #define IP_FW_F_FRAG 0x00008000 /* Fragment */ 187 188 #define IP_FW_F_IIFNAME 0x00010000 /* In interface by name/unit (not IP) */ 189 #define IP_FW_F_OIFNAME 0x00020000 /* Out interface by name/unit (not IP) */ 190 191 #define IP_FW_F_INVSRC 0x00040000 /* Invert sense of src check */ 192 #define IP_FW_F_INVDST 0x00080000 /* Invert sense of dst check */ 193 194 #define IP_FW_F_ICMPBIT 0x00100000 /* ICMP type bitmap is valid */ 195 196 #define IP_FW_F_UID 0x00200000 /* filter by uid */ 197 198 #define IP_FW_F_GID 0x00400000 /* filter by gid */ 199 200 #define IP_FW_F_RND_MATCH 0x00800000 /* probabilistic rule match */ 201 #define IP_FW_F_SMSK 0x01000000 /* src-port + mask */ 202 #define IP_FW_F_DMSK 0x02000000 /* dst-port + mask */ 203 #define IP_FW_BRIDGED 0x04000000 /* only match bridged packets */ 204 #define IP_FW_F_KEEP_S 0x08000000 /* keep state */ 205 #define IP_FW_F_CHECK_S 0x10000000 /* check state */ 206 207 #define IP_FW_F_MASK 0x1FFFFFFF /* All possible flag bits mask */ 208 209 /* 210 * For backwards compatibility with rules specifying "via iface" but 211 * not restricted to only "in" or "out" packets, we define this combination 212 * of bits to represent this configuration. 213 */ 214 215 #define IF_FW_F_VIAHACK (IP_FW_F_IN|IP_FW_F_OUT|IP_FW_F_IIFACE|IP_FW_F_OIFACE) 216 217 /* 218 * Definitions for REJECT response codes. 219 * Values less than 256 correspond to ICMP unreachable codes. 220 */ 221 #define IP_FW_REJECT_RST 0x0100 /* TCP packets: send RST */ 222 223 /* 224 * Definitions for IP option names. 225 */ 226 #define IP_FW_IPOPT_LSRR 0x01 227 #define IP_FW_IPOPT_SSRR 0x02 228 #define IP_FW_IPOPT_RR 0x04 229 #define IP_FW_IPOPT_TS 0x08 230 231 /* 232 * Definitions for TCP flags. 233 */ 234 #define IP_FW_TCPF_FIN TH_FIN 235 #define IP_FW_TCPF_SYN TH_SYN 236 #define IP_FW_TCPF_RST TH_RST 237 #define IP_FW_TCPF_PSH TH_PUSH 238 #define IP_FW_TCPF_ACK TH_ACK 239 #define IP_FW_TCPF_URG TH_URG 240 #define IP_FW_TCPF_ESTAB 0x40 241 242 /* 243 * Main firewall chains definitions and global var's definitions. 244 */ 245 #ifdef _KERNEL 246 247 #define IP_FW_PORT_DYNT_FLAG 0x10000 248 #define IP_FW_PORT_TEE_FLAG 0x20000 249 250 /* 251 * Function definitions. 252 */ 253 void ip_fw_init __P((void)); 254 255 /* Firewall hooks */ 256 struct ip; 257 struct sockopt; 258 typedef int ip_fw_chk_t __P((struct ip **, int, struct ifnet *, u_int16_t *, 259 struct mbuf **, struct ip_fw_chain **, struct sockaddr_in **)); 260 typedef int ip_fw_ctl_t __P((struct sockopt *)); 261 extern ip_fw_chk_t *ip_fw_chk_ptr; 262 extern ip_fw_ctl_t *ip_fw_ctl_ptr; 263 extern int fw_one_pass; 264 extern int fw_enable; 265 extern struct ipfw_flow_id last_pkt ; 266 #endif /* _KERNEL */ 267 268 #endif /* _IP_FW_H */ 269