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/param.h> 55 #include <sys/lock.h> 56 #include <sys/mutex.h> 57 58 /* XXX: LibAliasSetTarget() uses this constant. */ 59 #define INADDR_NONE 0xffffffff 60 61 #include <netinet/libalias/alias_sctp.h> 62 #else 63 #include "alias_sctp.h" 64 #endif 65 66 /* Sizes of input and output link tables */ 67 #define LINK_TABLE_OUT_SIZE 4001 68 #define LINK_TABLE_IN_SIZE 4001 69 70 struct proxy_entry; 71 72 struct libalias { 73 LIST_ENTRY(libalias) instancelist; 74 75 int packetAliasMode; /* Mode flags */ 76 /* - documented in alias.h */ 77 78 struct in_addr aliasAddress; /* Address written onto source */ 79 /* field of IP packet. */ 80 81 struct in_addr targetAddress; /* IP address incoming packets */ 82 /* are sent to if no aliasing */ 83 /* link already exists */ 84 85 struct in_addr nullAddress; /* Used as a dummy parameter for */ 86 /* some function calls */ 87 88 LIST_HEAD (, alias_link) linkTableOut[LINK_TABLE_OUT_SIZE]; 89 /* Lookup table of pointers to */ 90 /* chains of link records. Each */ 91 92 LIST_HEAD (, alias_link) linkTableIn[LINK_TABLE_IN_SIZE]; 93 /* link record is doubly indexed */ 94 /* into input and output lookup */ 95 /* tables. */ 96 97 /* Link statistics */ 98 int icmpLinkCount; 99 int udpLinkCount; 100 int tcpLinkCount; 101 int pptpLinkCount; 102 int protoLinkCount; 103 int fragmentIdLinkCount; 104 int fragmentPtrLinkCount; 105 int sockCount; 106 107 int cleanupIndex; /* Index to chain of link table */ 108 /* being inspected for old links */ 109 110 int timeStamp; /* System time in seconds for */ 111 /* current packet */ 112 113 int lastCleanupTime; /* Last time 114 * IncrementalCleanup() */ 115 /* was called */ 116 117 int deleteAllLinks; /* If equal to zero, DeleteLink() */ 118 /* will not remove permanent links */ 119 120 /* log descriptor */ 121 #ifdef _KERNEL 122 char *logDesc; 123 #else 124 FILE *logDesc; 125 #endif 126 /* statistics monitoring */ 127 128 int newDefaultLink; /* Indicates if a new aliasing */ 129 /* link has been created after a */ 130 /* call to PacketAliasIn/Out(). */ 131 132 #ifndef NO_FW_PUNCH 133 int fireWallFD; /* File descriptor to be able to */ 134 /* control firewall. Opened by */ 135 /* PacketAliasSetMode on first */ 136 /* setting the PKT_ALIAS_PUNCH_FW */ 137 /* flag. */ 138 int fireWallBaseNum; /* The first firewall entry 139 * free for our use */ 140 int fireWallNumNums; /* How many entries can we 141 * use? */ 142 int fireWallActiveNum; /* Which entry did we last 143 * use? */ 144 char *fireWallField; /* bool array for entries */ 145 #endif 146 147 unsigned int skinnyPort; /* TCP port used by the Skinny */ 148 /* protocol. */ 149 150 struct proxy_entry *proxyList; 151 152 struct in_addr true_addr; /* in network byte order. */ 153 u_short true_port; /* in host byte order. */ 154 155 /* 156 * sctp code support 157 */ 158 159 /* counts associations that have progressed to UP and not yet removed */ 160 int sctpLinkCount; 161 #ifdef _KERNEL 162 /* timing queue for keeping track of association timeouts */ 163 struct sctp_nat_timer sctpNatTimer; 164 165 /* size of hash table used in this instance */ 166 u_int sctpNatTableSize; 167 168 /* 169 * local look up table sorted by l_vtag/l_port 170 */ 171 LIST_HEAD(sctpNatTableL, sctp_nat_assoc) *sctpTableLocal; 172 /* 173 * global look up table sorted by g_vtag/g_port 174 */ 175 LIST_HEAD(sctpNatTableG, sctp_nat_assoc) *sctpTableGlobal; 176 177 /* 178 * avoid races in libalias: every public function has to use it. 179 */ 180 struct mtx mutex; 181 #endif 182 }; 183 184 /* Macros */ 185 186 #ifdef _KERNEL 187 #define LIBALIAS_LOCK_INIT(l) \ 188 mtx_init(&l->mutex, "per-instance libalias mutex", NULL, MTX_DEF) 189 #define LIBALIAS_LOCK_ASSERT(l) mtx_assert(&l->mutex, MA_OWNED) 190 #define LIBALIAS_LOCK(l) mtx_lock(&l->mutex) 191 #define LIBALIAS_UNLOCK(l) mtx_unlock(&l->mutex) 192 #define LIBALIAS_LOCK_DESTROY(l) mtx_destroy(&l->mutex) 193 #else 194 #define LIBALIAS_LOCK_INIT(l) 195 #define LIBALIAS_LOCK_ASSERT(l) 196 #define LIBALIAS_LOCK(l) 197 #define LIBALIAS_UNLOCK(l) 198 #define LIBALIAS_LOCK_DESTROY(l) 199 #endif 200 201 /* 202 * The following macro is used to update an 203 * internet checksum. "delta" is a 32-bit 204 * accumulation of all the changes to the 205 * checksum (adding in new 16-bit words and 206 * subtracting out old words), and "cksum" 207 * is the checksum value to be updated. 208 */ 209 #define ADJUST_CHECKSUM(acc, cksum) \ 210 do { \ 211 acc += cksum; \ 212 if (acc < 0) { \ 213 acc = -acc; \ 214 acc = (acc >> 16) + (acc & 0xffff); \ 215 acc += acc >> 16; \ 216 cksum = (u_short) ~acc; \ 217 } else { \ 218 acc = (acc >> 16) + (acc & 0xffff); \ 219 acc += acc >> 16; \ 220 cksum = (u_short) acc; \ 221 } \ 222 } while (0) 223 224 225 /* Prototypes */ 226 227 /* 228 * SctpFunction prototypes 229 * 230 */ 231 void AliasSctpInit(struct libalias *la); 232 void AliasSctpTerm(struct libalias *la); 233 int SctpAlias(struct libalias *la, struct ip *ip, int direction); 234 235 /* 236 * We do not calculate TCP checksums when libalias is a kernel 237 * module, since it has no idea about checksum offloading. 238 * If TCP data has changed, then we just set checksum to zero, 239 * and caller must recalculate it himself. 240 * In case if libalias will edit UDP data, the same approach 241 * should be used. 242 */ 243 #ifndef _KERNEL 244 u_short IpChecksum(struct ip *_pip); 245 u_short TcpChecksum(struct ip *_pip); 246 #endif 247 void 248 DifferentialChecksum(u_short * _cksum, void * _new, void * _old, int _n); 249 250 /* Internal data access */ 251 struct alias_link * 252 FindIcmpIn(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 253 u_short _id_alias, int _create); 254 struct alias_link * 255 FindIcmpOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 256 u_short _id, int _create); 257 struct alias_link * 258 FindFragmentIn1(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 259 u_short _ip_id); 260 struct alias_link * 261 FindFragmentIn2(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 262 u_short _ip_id); 263 struct alias_link * 264 AddFragmentPtrLink(struct libalias *la, struct in_addr _dst_addr, u_short _ip_id); 265 struct alias_link * 266 FindFragmentPtr(struct libalias *la, struct in_addr _dst_addr, u_short _ip_id); 267 struct alias_link * 268 FindProtoIn(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 269 u_char _proto); 270 struct alias_link * 271 FindProtoOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 272 u_char _proto); 273 struct alias_link * 274 FindUdpTcpIn(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 275 u_short _dst_port, u_short _alias_port, u_char _proto, int _create); 276 struct alias_link * 277 FindUdpTcpOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 278 u_short _src_port, u_short _dst_port, u_char _proto, int _create); 279 struct alias_link * 280 AddPptp(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 281 struct in_addr _alias_addr, u_int16_t _src_call_id); 282 struct alias_link * 283 FindPptpOutByCallId(struct libalias *la, struct in_addr _src_addr, 284 struct in_addr _dst_addr, u_int16_t _src_call_id); 285 struct alias_link * 286 FindPptpInByCallId(struct libalias *la, struct in_addr _dst_addr, 287 struct in_addr _alias_addr, u_int16_t _dst_call_id); 288 struct alias_link * 289 FindPptpOutByPeerCallId(struct libalias *la, struct in_addr _src_addr, 290 struct in_addr _dst_addr, u_int16_t _dst_call_id); 291 struct alias_link * 292 FindPptpInByPeerCallId(struct libalias *la, struct in_addr _dst_addr, 293 struct in_addr _alias_addr, u_int16_t _alias_call_id); 294 struct alias_link * 295 FindRtspOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 296 u_short _src_port, u_short _alias_port, u_char _proto); 297 struct in_addr 298 FindOriginalAddress(struct libalias *la, struct in_addr _alias_addr); 299 struct in_addr 300 FindAliasAddress(struct libalias *la, struct in_addr _original_addr); 301 struct in_addr 302 FindSctpRedirectAddress(struct libalias *la, struct sctp_nat_msg *sm); 303 304 /* External data access/modification */ 305 int 306 FindNewPortGroup(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 307 u_short _src_port, u_short _dst_port, u_short _port_count, 308 u_char _proto, u_char _align); 309 void GetFragmentAddr(struct alias_link *_lnk, struct in_addr *_src_addr); 310 void SetFragmentAddr(struct alias_link *_lnk, struct in_addr _src_addr); 311 void GetFragmentPtr(struct alias_link *_lnk, char **_fptr); 312 void SetFragmentPtr(struct alias_link *_lnk, char *fptr); 313 void SetStateIn(struct alias_link *_lnk, int _state); 314 void SetStateOut(struct alias_link *_lnk, int _state); 315 int GetStateIn (struct alias_link *_lnk); 316 int GetStateOut(struct alias_link *_lnk); 317 struct in_addr 318 GetOriginalAddress(struct alias_link *_lnk); 319 struct in_addr 320 GetDestAddress(struct alias_link *_lnk); 321 struct in_addr 322 GetAliasAddress(struct alias_link *_lnk); 323 struct in_addr 324 GetDefaultAliasAddress(struct libalias *la); 325 void SetDefaultAliasAddress(struct libalias *la, struct in_addr _alias_addr); 326 u_short GetOriginalPort(struct alias_link *_lnk); 327 u_short GetAliasPort(struct alias_link *_lnk); 328 struct in_addr 329 GetProxyAddress(struct alias_link *_lnk); 330 void SetProxyAddress(struct alias_link *_lnk, struct in_addr _addr); 331 u_short GetProxyPort(struct alias_link *_lnk); 332 void SetProxyPort(struct alias_link *_lnk, u_short _port); 333 void SetAckModified(struct alias_link *_lnk); 334 int GetAckModified(struct alias_link *_lnk); 335 int GetDeltaAckIn(u_long, struct alias_link *_lnk); 336 int GetDeltaSeqOut(u_long, struct alias_link *lnk); 337 void AddSeq(struct alias_link *lnk, int delta, u_int ip_hl, 338 u_short ip_len, u_long th_seq, u_int th_off); 339 void SetExpire (struct alias_link *_lnk, int _expire); 340 void ClearCheckNewLink(struct libalias *la); 341 void SetProtocolFlags(struct alias_link *_lnk, int _pflags); 342 int GetProtocolFlags(struct alias_link *_lnk); 343 void SetDestCallId(struct alias_link *_lnk, u_int16_t _cid); 344 345 #ifndef NO_FW_PUNCH 346 void PunchFWHole(struct alias_link *_lnk); 347 348 #endif 349 350 /* Housekeeping function */ 351 void HouseKeeping(struct libalias *); 352 353 /* Tcp specfic routines */ 354 /* lint -save -library Suppress flexelint warnings */ 355 356 /* Transparent proxy routines */ 357 int 358 ProxyCheck(struct libalias *la, struct in_addr *proxy_server_addr, 359 u_short * proxy_server_port, struct in_addr src_addr, 360 struct in_addr dst_addr, u_short dst_port, u_char ip_p); 361 void 362 ProxyModify(struct libalias *la, struct alias_link *_lnk, struct ip *_pip, 363 int _maxpacketsize, int _proxy_type); 364 365 enum alias_tcp_state { 366 ALIAS_TCP_STATE_NOT_CONNECTED, 367 ALIAS_TCP_STATE_CONNECTED, 368 ALIAS_TCP_STATE_DISCONNECTED 369 }; 370 371 #if defined(_NETINET_IP_H_) 372 static __inline void * 373 ip_next(struct ip *iphdr) 374 { 375 char *p = (char *)iphdr; 376 return (&p[iphdr->ip_hl * 4]); 377 } 378 #endif 379 380 #if defined(_NETINET_TCP_H_) 381 static __inline void * 382 tcp_next(struct tcphdr *tcphdr) 383 { 384 char *p = (char *)tcphdr; 385 return (&p[tcphdr->th_off * 4]); 386 } 387 #endif 388 389 #if defined(_NETINET_UDP_H_) 390 static __inline void * 391 udp_next(struct udphdr *udphdr) 392 { 393 return ((void *)(udphdr + 1)); 394 } 395 #endif 396 397 #endif /* !_ALIAS_LOCAL_H_ */ 398