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 #define GET_ALIAS_PORT -1 71 #define GET_ALIAS_ID GET_ALIAS_PORT 72 73 struct proxy_entry; 74 75 struct libalias { 76 LIST_ENTRY(libalias) instancelist; 77 78 int packetAliasMode; /* Mode flags */ 79 /* - documented in alias.h */ 80 81 struct in_addr aliasAddress; /* Address written onto source */ 82 /* field of IP packet. */ 83 84 struct in_addr targetAddress; /* IP address incoming packets */ 85 /* are sent to if no aliasing */ 86 /* link already exists */ 87 88 struct in_addr nullAddress; /* Used as a dummy parameter for */ 89 /* some function calls */ 90 91 LIST_HEAD (, alias_link) linkTableOut[LINK_TABLE_OUT_SIZE]; 92 /* Lookup table of pointers to */ 93 /* chains of link records. Each */ 94 95 LIST_HEAD (, alias_link) linkTableIn[LINK_TABLE_IN_SIZE]; 96 /* link record is doubly indexed */ 97 /* into input and output lookup */ 98 /* tables. */ 99 100 /* Link statistics */ 101 int icmpLinkCount; 102 int udpLinkCount; 103 int tcpLinkCount; 104 int pptpLinkCount; 105 int protoLinkCount; 106 int fragmentIdLinkCount; 107 int fragmentPtrLinkCount; 108 int sockCount; 109 110 int cleanupIndex; /* Index to chain of link table */ 111 /* being inspected for old links */ 112 113 int timeStamp; /* System time in seconds for */ 114 /* current packet */ 115 116 int lastCleanupTime; /* Last time 117 * IncrementalCleanup() */ 118 /* was called */ 119 120 int deleteAllLinks; /* If equal to zero, DeleteLink() */ 121 /* will not remove permanent links */ 122 123 /* log descriptor */ 124 #ifdef _KERNEL 125 char *logDesc; 126 #else 127 FILE *logDesc; 128 #endif 129 /* statistics monitoring */ 130 131 int newDefaultLink; /* Indicates if a new aliasing */ 132 /* link has been created after a */ 133 /* call to PacketAliasIn/Out(). */ 134 135 #ifndef NO_FW_PUNCH 136 int fireWallFD; /* File descriptor to be able to */ 137 /* control firewall. Opened by */ 138 /* PacketAliasSetMode on first */ 139 /* setting the PKT_ALIAS_PUNCH_FW */ 140 /* flag. */ 141 int fireWallBaseNum; /* The first firewall entry 142 * free for our use */ 143 int fireWallNumNums; /* How many entries can we 144 * use? */ 145 int fireWallActiveNum; /* Which entry did we last 146 * use? */ 147 char *fireWallField; /* bool array for entries */ 148 #endif 149 150 unsigned int skinnyPort; /* TCP port used by the Skinny */ 151 /* protocol. */ 152 153 struct proxy_entry *proxyList; 154 155 struct in_addr true_addr; /* in network byte order. */ 156 u_short true_port; /* in host byte order. */ 157 158 /* 159 * sctp code support 160 */ 161 162 /* counts associations that have progressed to UP and not yet removed */ 163 int sctpLinkCount; 164 #ifdef _KERNEL 165 /* timing queue for keeping track of association timeouts */ 166 struct sctp_nat_timer sctpNatTimer; 167 168 /* size of hash table used in this instance */ 169 u_int sctpNatTableSize; 170 171 /* 172 * local look up table sorted by l_vtag/l_port 173 */ 174 LIST_HEAD(sctpNatTableL, sctp_nat_assoc) *sctpTableLocal; 175 /* 176 * global look up table sorted by g_vtag/g_port 177 */ 178 LIST_HEAD(sctpNatTableG, sctp_nat_assoc) *sctpTableGlobal; 179 180 /* 181 * avoid races in libalias: every public function has to use it. 182 */ 183 struct mtx mutex; 184 #endif 185 }; 186 187 /* Macros */ 188 189 #ifdef _KERNEL 190 #define LIBALIAS_LOCK_INIT(l) \ 191 mtx_init(&l->mutex, "per-instance libalias mutex", NULL, MTX_DEF) 192 #define LIBALIAS_LOCK_ASSERT(l) mtx_assert(&l->mutex, MA_OWNED) 193 #define LIBALIAS_LOCK(l) mtx_lock(&l->mutex) 194 #define LIBALIAS_UNLOCK(l) mtx_unlock(&l->mutex) 195 #define LIBALIAS_LOCK_DESTROY(l) mtx_destroy(&l->mutex) 196 #else 197 #define LIBALIAS_LOCK_INIT(l) 198 #define LIBALIAS_LOCK_ASSERT(l) 199 #define LIBALIAS_LOCK(l) 200 #define LIBALIAS_UNLOCK(l) 201 #define LIBALIAS_LOCK_DESTROY(l) 202 #endif 203 204 /* 205 * The following macro is used to update an 206 * internet checksum. "delta" is a 32-bit 207 * accumulation of all the changes to the 208 * checksum (adding in new 16-bit words and 209 * subtracting out old words), and "cksum" 210 * is the checksum value to be updated. 211 */ 212 #define ADJUST_CHECKSUM(acc, cksum) \ 213 do { \ 214 acc += cksum; \ 215 if (acc < 0) { \ 216 acc = -acc; \ 217 acc = (acc >> 16) + (acc & 0xffff); \ 218 acc += acc >> 16; \ 219 cksum = (u_short) ~acc; \ 220 } else { \ 221 acc = (acc >> 16) + (acc & 0xffff); \ 222 acc += acc >> 16; \ 223 cksum = (u_short) acc; \ 224 } \ 225 } while (0) 226 227 228 /* Prototypes */ 229 230 /* 231 * SctpFunction prototypes 232 * 233 */ 234 void AliasSctpInit(struct libalias *la); 235 void AliasSctpTerm(struct libalias *la); 236 int SctpAlias(struct libalias *la, struct ip *ip, int direction); 237 238 /* 239 * We do not calculate TCP checksums when libalias is a kernel 240 * module, since it has no idea about checksum offloading. 241 * If TCP data has changed, then we just set checksum to zero, 242 * and caller must recalculate it himself. 243 * In case if libalias will edit UDP data, the same approach 244 * should be used. 245 */ 246 #ifndef _KERNEL 247 u_short IpChecksum(struct ip *_pip); 248 u_short TcpChecksum(struct ip *_pip); 249 #endif 250 void 251 DifferentialChecksum(u_short * _cksum, void * _new, void * _old, int _n); 252 253 /* Internal data access */ 254 struct alias_link * 255 AddLink(struct libalias *la, struct in_addr src_addr, struct in_addr dst_addr, 256 struct in_addr alias_addr, u_short src_port, u_short dst_port, 257 int alias_param, int link_type); 258 struct alias_link * 259 FindIcmpIn(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 260 u_short _id_alias, int _create); 261 struct alias_link * 262 FindIcmpOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 263 u_short _id, int _create); 264 struct alias_link * 265 FindFragmentIn1(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 266 u_short _ip_id); 267 struct alias_link * 268 FindFragmentIn2(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 269 u_short _ip_id); 270 struct alias_link * 271 AddFragmentPtrLink(struct libalias *la, struct in_addr _dst_addr, u_short _ip_id); 272 struct alias_link * 273 FindFragmentPtr(struct libalias *la, struct in_addr _dst_addr, u_short _ip_id); 274 struct alias_link * 275 FindProtoIn(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 276 u_char _proto); 277 struct alias_link * 278 FindProtoOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 279 u_char _proto); 280 struct alias_link * 281 FindUdpTcpIn(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 282 u_short _dst_port, u_short _alias_port, u_char _proto, int _create); 283 struct alias_link * 284 FindUdpTcpOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 285 u_short _src_port, u_short _dst_port, u_char _proto, int _create); 286 struct alias_link * 287 AddPptp(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 288 struct in_addr _alias_addr, u_int16_t _src_call_id); 289 struct alias_link * 290 FindPptpOutByCallId(struct libalias *la, struct in_addr _src_addr, 291 struct in_addr _dst_addr, u_int16_t _src_call_id); 292 struct alias_link * 293 FindPptpInByCallId(struct libalias *la, struct in_addr _dst_addr, 294 struct in_addr _alias_addr, u_int16_t _dst_call_id); 295 struct alias_link * 296 FindPptpOutByPeerCallId(struct libalias *la, struct in_addr _src_addr, 297 struct in_addr _dst_addr, u_int16_t _dst_call_id); 298 struct alias_link * 299 FindPptpInByPeerCallId(struct libalias *la, struct in_addr _dst_addr, 300 struct in_addr _alias_addr, u_int16_t _alias_call_id); 301 struct alias_link * 302 FindRtspOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 303 u_short _src_port, u_short _alias_port, u_char _proto); 304 struct in_addr 305 FindOriginalAddress(struct libalias *la, struct in_addr _alias_addr); 306 struct in_addr 307 FindAliasAddress(struct libalias *la, struct in_addr _original_addr); 308 struct in_addr 309 FindSctpRedirectAddress(struct libalias *la, struct sctp_nat_msg *sm); 310 311 /* External data access/modification */ 312 int 313 FindNewPortGroup(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 314 u_short _src_port, u_short _dst_port, u_short _port_count, 315 u_char _proto, u_char _align); 316 void GetFragmentAddr(struct alias_link *_lnk, struct in_addr *_src_addr); 317 void SetFragmentAddr(struct alias_link *_lnk, struct in_addr _src_addr); 318 void GetFragmentPtr(struct alias_link *_lnk, char **_fptr); 319 void SetFragmentPtr(struct alias_link *_lnk, char *fptr); 320 void SetStateIn(struct alias_link *_lnk, int _state); 321 void SetStateOut(struct alias_link *_lnk, int _state); 322 int GetStateIn (struct alias_link *_lnk); 323 int GetStateOut(struct alias_link *_lnk); 324 struct in_addr 325 GetOriginalAddress(struct alias_link *_lnk); 326 struct in_addr 327 GetDestAddress(struct alias_link *_lnk); 328 struct in_addr 329 GetAliasAddress(struct alias_link *_lnk); 330 struct in_addr 331 GetDefaultAliasAddress(struct libalias *la); 332 void SetDefaultAliasAddress(struct libalias *la, struct in_addr _alias_addr); 333 u_short GetOriginalPort(struct alias_link *_lnk); 334 u_short GetAliasPort(struct alias_link *_lnk); 335 struct in_addr 336 GetProxyAddress(struct alias_link *_lnk); 337 void SetProxyAddress(struct alias_link *_lnk, struct in_addr _addr); 338 u_short GetProxyPort(struct alias_link *_lnk); 339 void SetProxyPort(struct alias_link *_lnk, u_short _port); 340 void SetAckModified(struct alias_link *_lnk); 341 int GetAckModified(struct alias_link *_lnk); 342 int GetDeltaAckIn(u_long, struct alias_link *_lnk); 343 int GetDeltaSeqOut(u_long, struct alias_link *lnk); 344 void AddSeq(struct alias_link *lnk, int delta, u_int ip_hl, 345 u_short ip_len, u_long th_seq, u_int th_off); 346 void SetExpire (struct alias_link *_lnk, int _expire); 347 void ClearCheckNewLink(struct libalias *la); 348 void SetProtocolFlags(struct alias_link *_lnk, int _pflags); 349 int GetProtocolFlags(struct alias_link *_lnk); 350 void SetDestCallId(struct alias_link *_lnk, u_int16_t _cid); 351 352 #ifndef NO_FW_PUNCH 353 void PunchFWHole(struct alias_link *_lnk); 354 355 #endif 356 357 /* Housekeeping function */ 358 void HouseKeeping(struct libalias *); 359 360 /* Tcp specific routines */ 361 /* lint -save -library Suppress flexelint warnings */ 362 363 /* Transparent proxy routines */ 364 int 365 ProxyCheck(struct libalias *la, struct in_addr *proxy_server_addr, 366 u_short * proxy_server_port, struct in_addr src_addr, 367 struct in_addr dst_addr, u_short dst_port, u_char ip_p); 368 void 369 ProxyModify(struct libalias *la, struct alias_link *_lnk, struct ip *_pip, 370 int _maxpacketsize, int _proxy_type); 371 372 enum alias_tcp_state { 373 ALIAS_TCP_STATE_NOT_CONNECTED, 374 ALIAS_TCP_STATE_CONNECTED, 375 ALIAS_TCP_STATE_DISCONNECTED 376 }; 377 378 #if defined(_NETINET_IP_H_) 379 static __inline void * 380 ip_next(struct ip *iphdr) 381 { 382 char *p = (char *)iphdr; 383 return (&p[iphdr->ip_hl * 4]); 384 } 385 #endif 386 387 #if defined(_NETINET_TCP_H_) 388 static __inline void * 389 tcp_next(struct tcphdr *tcphdr) 390 { 391 char *p = (char *)tcphdr; 392 return (&p[tcphdr->th_off * 4]); 393 } 394 #endif 395 396 #if defined(_NETINET_UDP_H_) 397 static __inline void * 398 udp_next(struct udphdr *udphdr) 399 { 400 return ((void *)(udphdr + 1)); 401 } 402 #endif 403 404 #endif /* !_ALIAS_LOCAL_H_ */ 405