1 /*- 2 * Copyright (c) 2001 Charles Mott <cm@linktel.net> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29 /* 30 * Alias_local.h contains the function prototypes for alias.c, 31 * alias_db.c, alias_util.c and alias_ftp.c, alias_irc.c (as well 32 * as any future add-ons). It also includes macros, globals and 33 * struct definitions shared by more than one alias*.c file. 34 * 35 * This include file is intended to be used only within the aliasing 36 * software. Outside world interfaces are defined in alias.h 37 * 38 * This software is placed into the public domain with no restrictions 39 * on its distribution. 40 * 41 * Initial version: August, 1996 (cjm) 42 * 43 * <updated several times by original author and Eivind Eklund> 44 */ 45 46 #ifndef _ALIAS_LOCAL_H_ 47 #define _ALIAS_LOCAL_H_ 48 49 #include <sys/types.h> 50 #include <sys/sysctl.h> 51 52 #ifdef _KERNEL 53 #include <sys/malloc.h> 54 #include <sys/lock.h> 55 /* XXX: LibAliasSetTarget() uses this constant. */ 56 #define INADDR_NONE 0xffffffff 57 #endif 58 59 /* Sizes of input and output link tables */ 60 #define LINK_TABLE_OUT_SIZE 101 61 #define LINK_TABLE_IN_SIZE 4001 62 63 struct proxy_entry; 64 65 struct libalias { 66 LIST_ENTRY(libalias) instancelist; 67 68 int packetAliasMode; /* Mode flags */ 69 /* - documented in alias.h */ 70 71 struct in_addr aliasAddress; /* Address written onto source */ 72 /* field of IP packet. */ 73 74 struct in_addr targetAddress; /* IP address incoming packets */ 75 /* are sent to if no aliasing */ 76 /* link already exists */ 77 78 struct in_addr nullAddress; /* Used as a dummy parameter for */ 79 /* some function calls */ 80 81 LIST_HEAD (, alias_link) linkTableOut[LINK_TABLE_OUT_SIZE]; 82 /* Lookup table of pointers to */ 83 /* chains of link records. Each */ 84 85 LIST_HEAD (, alias_link) linkTableIn[LINK_TABLE_IN_SIZE]; 86 /* link record is doubly indexed */ 87 /* into input and output lookup */ 88 /* tables. */ 89 90 /* Link statistics */ 91 int icmpLinkCount; 92 int udpLinkCount; 93 int tcpLinkCount; 94 int pptpLinkCount; 95 int protoLinkCount; 96 int fragmentIdLinkCount; 97 int fragmentPtrLinkCount; 98 int sockCount; 99 100 int cleanupIndex; /* Index to chain of link table */ 101 /* being inspected for old links */ 102 103 int timeStamp; /* System time in seconds for */ 104 /* current packet */ 105 106 int lastCleanupTime; /* Last time 107 * IncrementalCleanup() */ 108 /* was called */ 109 110 int houseKeepingResidual; /* used by HouseKeeping() */ 111 112 int deleteAllLinks; /* If equal to zero, DeleteLink() */ 113 /* will not remove permanent links */ 114 115 /* log descriptor */ 116 #ifdef _KERNEL 117 char *logDesc; 118 #else 119 FILE *logDesc; 120 #endif 121 /* statistics monitoring */ 122 123 int newDefaultLink; /* Indicates if a new aliasing */ 124 /* link has been created after a */ 125 /* call to PacketAliasIn/Out(). */ 126 127 #ifndef NO_FW_PUNCH 128 int fireWallFD; /* File descriptor to be able to */ 129 /* control firewall. Opened by */ 130 /* PacketAliasSetMode on first */ 131 /* setting the PKT_ALIAS_PUNCH_FW */ 132 /* flag. */ 133 int fireWallBaseNum; /* The first firewall entry 134 * free for our use */ 135 int fireWallNumNums; /* How many entries can we 136 * use? */ 137 int fireWallActiveNum; /* Which entry did we last 138 * use? */ 139 char *fireWallField; /* bool array for entries */ 140 #endif 141 142 unsigned int skinnyPort; /* TCP port used by the Skinny */ 143 /* protocol. */ 144 145 struct proxy_entry *proxyList; 146 147 struct in_addr true_addr; /* in network byte order. */ 148 u_short true_port; /* in host byte order. */ 149 150 }; 151 152 /* Macros */ 153 154 /* 155 * The following macro is used to update an 156 * internet checksum. "delta" is a 32-bit 157 * accumulation of all the changes to the 158 * checksum (adding in new 16-bit words and 159 * subtracting out old words), and "cksum" 160 * is the checksum value to be updated. 161 */ 162 #define ADJUST_CHECKSUM(acc, cksum) \ 163 do { \ 164 acc += cksum; \ 165 if (acc < 0) { \ 166 acc = -acc; \ 167 acc = (acc >> 16) + (acc & 0xffff); \ 168 acc += acc >> 16; \ 169 cksum = (u_short) ~acc; \ 170 } else { \ 171 acc = (acc >> 16) + (acc & 0xffff); \ 172 acc += acc >> 16; \ 173 cksum = (u_short) acc; \ 174 } \ 175 } while (0) 176 177 178 /* Prototypes */ 179 180 /* 181 * We do not calculate TCP checksums when libalias is a kernel 182 * module, since it has no idea about checksum offloading. 183 * If TCP data has changed, then we just set checksum to zero, 184 * and caller must recalculate it himself. 185 * In case if libalias will edit UDP data, the same approach 186 * should be used. 187 */ 188 #ifndef _KERNEL 189 u_short IpChecksum(struct ip *_pip); 190 u_short TcpChecksum(struct ip *_pip); 191 #endif 192 void 193 DifferentialChecksum(u_short * _cksum, void * _new, void * _old, int _n); 194 195 /* Internal data access */ 196 struct alias_link * 197 FindIcmpIn(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 198 u_short _id_alias, int _create); 199 struct alias_link * 200 FindIcmpOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 201 u_short _id, int _create); 202 struct alias_link * 203 FindFragmentIn1(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 204 u_short _ip_id); 205 struct alias_link * 206 FindFragmentIn2(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 207 u_short _ip_id); 208 struct alias_link * 209 AddFragmentPtrLink(struct libalias *la, struct in_addr _dst_addr, u_short _ip_id); 210 struct alias_link * 211 FindFragmentPtr(struct libalias *la, struct in_addr _dst_addr, u_short _ip_id); 212 struct alias_link * 213 FindProtoIn(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 214 u_char _proto); 215 struct alias_link * 216 FindProtoOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 217 u_char _proto); 218 struct alias_link * 219 FindUdpTcpIn(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 220 u_short _dst_port, u_short _alias_port, u_char _proto, int _create); 221 struct alias_link * 222 FindUdpTcpOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 223 u_short _src_port, u_short _dst_port, u_char _proto, int _create); 224 struct alias_link * 225 AddPptp(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 226 struct in_addr _alias_addr, u_int16_t _src_call_id); 227 struct alias_link * 228 FindPptpOutByCallId(struct libalias *la, struct in_addr _src_addr, 229 struct in_addr _dst_addr, u_int16_t _src_call_id); 230 struct alias_link * 231 FindPptpInByCallId(struct libalias *la, struct in_addr _dst_addr, 232 struct in_addr _alias_addr, u_int16_t _dst_call_id); 233 struct alias_link * 234 FindPptpOutByPeerCallId(struct libalias *la, struct in_addr _src_addr, 235 struct in_addr _dst_addr, u_int16_t _dst_call_id); 236 struct alias_link * 237 FindPptpInByPeerCallId(struct libalias *la, struct in_addr _dst_addr, 238 struct in_addr _alias_addr, u_int16_t _alias_call_id); 239 struct alias_link * 240 FindRtspOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 241 u_short _src_port, u_short _alias_port, u_char _proto); 242 struct in_addr 243 FindOriginalAddress(struct libalias *la, struct in_addr _alias_addr); 244 struct in_addr 245 FindAliasAddress(struct libalias *la, struct in_addr _original_addr); 246 247 /* External data access/modification */ 248 int 249 FindNewPortGroup(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 250 u_short _src_port, u_short _dst_port, u_short _port_count, 251 u_char _proto, u_char _align); 252 void GetFragmentAddr(struct alias_link *_lnk, struct in_addr *_src_addr); 253 void SetFragmentAddr(struct alias_link *_lnk, struct in_addr _src_addr); 254 void GetFragmentPtr(struct alias_link *_lnk, char **_fptr); 255 void SetFragmentPtr(struct alias_link *_lnk, char *fptr); 256 void SetStateIn(struct alias_link *_lnk, int _state); 257 void SetStateOut(struct alias_link *_lnk, int _state); 258 int GetStateIn (struct alias_link *_lnk); 259 int GetStateOut(struct alias_link *_lnk); 260 struct in_addr 261 GetOriginalAddress(struct alias_link *_lnk); 262 struct in_addr 263 GetDestAddress(struct alias_link *_lnk); 264 struct in_addr 265 GetAliasAddress(struct alias_link *_lnk); 266 struct in_addr 267 GetDefaultAliasAddress(struct libalias *la); 268 void SetDefaultAliasAddress(struct libalias *la, struct in_addr _alias_addr); 269 u_short GetOriginalPort(struct alias_link *_lnk); 270 u_short GetAliasPort(struct alias_link *_lnk); 271 struct in_addr 272 GetProxyAddress(struct alias_link *_lnk); 273 void SetProxyAddress(struct alias_link *_lnk, struct in_addr _addr); 274 u_short GetProxyPort(struct alias_link *_lnk); 275 void SetProxyPort(struct alias_link *_lnk, u_short _port); 276 void SetAckModified(struct alias_link *_lnk); 277 int GetAckModified(struct alias_link *_lnk); 278 int GetDeltaAckIn(struct ip *_pip, struct alias_link *_lnk); 279 int GetDeltaSeqOut(struct ip *_pip, struct alias_link *_lnk); 280 void AddSeq (struct ip *_pip, struct alias_link *_lnk, int _delta); 281 void SetExpire (struct alias_link *_lnk, int _expire); 282 void ClearCheckNewLink(struct libalias *la); 283 void SetProtocolFlags(struct alias_link *_lnk, int _pflags); 284 int GetProtocolFlags(struct alias_link *_lnk); 285 void SetDestCallId(struct alias_link *_lnk, u_int16_t _cid); 286 287 #ifndef NO_FW_PUNCH 288 void PunchFWHole(struct alias_link *_lnk); 289 290 #endif 291 292 /* Housekeeping function */ 293 void HouseKeeping(struct libalias *); 294 295 /* Tcp specfic routines */ 296 /* lint -save -library Suppress flexelint warnings */ 297 298 /* Transparent proxy routines */ 299 int 300 ProxyCheck(struct libalias *la, struct ip *_pip, struct in_addr *_proxy_server_addr, 301 u_short * _proxy_server_port); 302 void 303 ProxyModify(struct libalias *la, struct alias_link *_lnk, struct ip *_pip, 304 int _maxpacketsize, int _proxy_type); 305 306 enum alias_tcp_state { 307 ALIAS_TCP_STATE_NOT_CONNECTED, 308 ALIAS_TCP_STATE_CONNECTED, 309 ALIAS_TCP_STATE_DISCONNECTED 310 }; 311 312 #if defined(_NETINET_IP_H_) 313 static __inline void * 314 ip_next(struct ip *iphdr) 315 { 316 char *p = (char *)iphdr; 317 return (&p[iphdr->ip_hl * 4]); 318 } 319 #endif 320 321 #if defined(_NETINET_TCP_H_) 322 static __inline void * 323 tcp_next(struct tcphdr *tcphdr) 324 { 325 char *p = (char *)tcphdr; 326 return (&p[tcphdr->th_off * 4]); 327 } 328 #endif 329 330 #if defined(_NETINET_UDP_H_) 331 static __inline void * 332 udp_next(struct udphdr *udphdr) 333 { 334 return ((void *)(udphdr + 1)); 335 } 336 #endif 337 338 #endif /* !_ALIAS_LOCAL_H_ */ 339