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