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