sys/net/libalias/alias_local.h

   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: src/sys/netinet/libalias/alias_local.h,v 1.34.2.1.2.1 2008/11/25 02:59:29 kensmith Exp $
  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 lock mutex;
 155 #endif
 156 };
 157
 158 /* Macros */
 159
 160 #ifdef _KERNEL
 161 #define LIBALIAS_LOCK_INIT(l) \
 162                 lockinit(&l->mutex, "per-instance libalias mutex", 0, LK_CANRECURSE);
 163 //#define LIBALIAS_LOCK_ASSERT(l) KKASSERT(lockstatus(&l->mutex, curthread) != 0)
 164 #define LIBALIAS_LOCK_ASSERT(l)
 165 #define LIBALIAS_LOCK(l) lockmgr(&l->mutex, LK_EXCLUSIVE);
 166 #define LIBALIAS_UNLOCK(l) lockmgr(&l->mutex, LK_RELEASE);
 167 #define LIBALIAS_LOCK_DESTROY(l)        lockuninit(&l->mutex)
 168 #else
 169 #define LIBALIAS_LOCK_INIT(l)
 170 #define LIBALIAS_LOCK_ASSERT(l)
 171 #define LIBALIAS_LOCK(l)
 172 #define LIBALIAS_UNLOCK(l)
 173 #define LIBALIAS_LOCK_DESTROY(l)
 174 #endif
 175
 176 /*
 177  * The following macro is used to update an
 178  * internet checksum.  "delta" is a 32-bit
 179  * accumulation of all the changes to the
 180  * checksum (adding in new 16-bit words and
 181  * subtracting out old words), and "cksum"
 182  * is the checksum value to be updated.
 183  */
 184 #define ADJUST_CHECKSUM(acc, cksum) \
 185         do { \
 186                 acc += cksum; \
 187                 if (acc < 0) { \
 188                         acc = -acc; \
 189                         acc = (acc >> 16) + (acc & 0xffff); \
 190                         acc += acc >> 16; \
 191                         cksum = (u_short) ~acc; \
 192                 } else { \
 193                         acc = (acc >> 16) + (acc & 0xffff); \
 194                         acc += acc >> 16; \
 195                         cksum = (u_short) acc; \
 196                 } \
 197         } while (0)
 198
 199
 200 /* Prototypes */
 201
 202 /*
 203  * We do not calculate TCP checksums when libalias is a kernel
 204  * module, since it has no idea about checksum offloading.
 205  * If TCP data has changed, then we just set checksum to zero,
 206  * and caller must recalculate it himself.
 207  * In case if libalias will edit UDP data, the same approach
 208  * should be used.
 209  */
 210 #ifndef _KERNEL
 211 u_short         IpChecksum(struct ip *_pip);
 212 u_short         TcpChecksum(struct ip *_pip);
 213 #endif
 214 void
 215 DifferentialChecksum(u_short * _cksum, void * _new, void * _old, int _n);
 216
 217 /* Internal data access */
 218 struct alias_link *
 219 FindIcmpIn(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr,
 220         u_short _id_alias, int _create);
 221 struct alias_link *
 222 FindIcmpOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr,
 223         u_short _id, int _create);
 224 struct alias_link *
 225 FindFragmentIn1(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr,
 226         u_short _ip_id);
 227 struct alias_link *
 228 FindFragmentIn2(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr,
 229         u_short _ip_id);
 230 struct alias_link *
 231                 AddFragmentPtrLink(struct libalias *la, struct in_addr _dst_addr, u_short _ip_id);
 232 struct alias_link *
 233                 FindFragmentPtr(struct libalias *la, struct in_addr _dst_addr, u_short _ip_id);
 234 struct alias_link *
 235 FindProtoIn(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr,
 236         u_char _proto);
 237 struct alias_link *
 238 FindProtoOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr,
 239         u_char _proto);
 240 struct alias_link *
 241 FindUdpTcpIn(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr,
 242         u_short _dst_port, u_short _alias_port, u_char _proto, int _create);
 243 struct alias_link *
 244 FindUdpTcpOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr,
 245         u_short _src_port, u_short _dst_port, u_char _proto, int _create);
 246 struct alias_link *
 247 AddPptp(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr,
 248         struct in_addr _alias_addr, u_int16_t _src_call_id);
 249 struct alias_link *
 250 FindPptpOutByCallId(struct libalias *la, struct in_addr _src_addr,
 251         struct in_addr _dst_addr, u_int16_t _src_call_id);
 252 struct alias_link *
 253 FindPptpInByCallId(struct libalias *la, struct in_addr _dst_addr,
 254         struct in_addr _alias_addr, u_int16_t _dst_call_id);
 255 struct alias_link *
 256 FindPptpOutByPeerCallId(struct libalias *la, struct in_addr _src_addr,
 257         struct in_addr _dst_addr, u_int16_t _dst_call_id);
 258 struct alias_link *
 259 FindPptpInByPeerCallId(struct libalias *la, struct in_addr _dst_addr,
 260         struct in_addr _alias_addr, u_int16_t _alias_call_id);
 261 struct alias_link *
 262 FindRtspOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr,
 263         u_short _src_port, u_short _alias_port, u_char _proto);
 264 struct in_addr
 265                 FindOriginalAddress(struct libalias *la, struct in_addr _alias_addr);
 266 struct in_addr
 267                 FindAliasAddress(struct libalias *la, struct in_addr _original_addr);
 268
 269 /* External data access/modification */
 270 int
 271 FindNewPortGroup(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr,
 272         u_short _src_port, u_short _dst_port, u_short _port_count,
 273         u_char _proto, u_char _align);
 274 void            GetFragmentAddr(struct alias_link *_lnk, struct in_addr *_src_addr);
 275 void            SetFragmentAddr(struct alias_link *_lnk, struct in_addr _src_addr);
 276 void            GetFragmentPtr(struct alias_link *_lnk, char **_fptr);
 277 void            SetFragmentPtr(struct alias_link *_lnk, char *fptr);
 278 void            SetStateIn(struct alias_link *_lnk, int _state);
 279 void            SetStateOut(struct alias_link *_lnk, int _state);
 280 int             GetStateIn (struct alias_link *_lnk);
 281 int             GetStateOut(struct alias_link *_lnk);
 282 struct in_addr
 283                 GetOriginalAddress(struct alias_link *_lnk);
 284 struct in_addr
 285                 GetDestAddress(struct alias_link *_lnk);
 286 struct in_addr
 287                 GetAliasAddress(struct alias_link *_lnk);
 288 struct in_addr
 289                 GetDefaultAliasAddress(struct libalias *la);
 290 void            SetDefaultAliasAddress(struct libalias *la, struct in_addr _alias_addr);
 291 u_short         GetOriginalPort(struct alias_link *_lnk);
 292 u_short         GetAliasPort(struct alias_link *_lnk);
 293 struct in_addr
 294                 GetProxyAddress(struct alias_link *_lnk);
 295 void            SetProxyAddress(struct alias_link *_lnk, struct in_addr _addr);
 296 u_short         GetProxyPort(struct alias_link *_lnk);
 297 void            SetProxyPort(struct alias_link *_lnk, u_short _port);
 298 void            SetAckModified(struct alias_link *_lnk);
 299 int             GetAckModified(struct alias_link *_lnk);
 300 int             GetDeltaAckIn(struct ip *_pip, struct alias_link *_lnk);
 301 int             GetDeltaSeqOut(struct ip *_pip, struct alias_link *_lnk);
 302 void            AddSeq  (struct ip *_pip, struct alias_link *_lnk, int _delta);
 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 ip *_pip, struct in_addr *_proxy_server_addr,
 323         u_short * _proxy_server_port);
 324 void
 325 ProxyModify(struct libalias *la, struct alias_link *_lnk, struct ip *_pip,
 326         int _maxpacketsize, int _proxy_type);
 327
 328 enum alias_tcp_state {
 329         ALIAS_TCP_STATE_NOT_CONNECTED,
 330         ALIAS_TCP_STATE_CONNECTED,
 331         ALIAS_TCP_STATE_DISCONNECTED
 332 };
 333
 334 #if defined(_NETINET_IP_H_)
 335 static __inline void *
 336 ip_next(struct ip *iphdr)
 337 {
 338         char *p = (char *)iphdr;
 339         return (&p[iphdr->ip_hl * 4]);
 340 }
 341 #endif
 342
 343 #if defined(_NETINET_TCP_H_)
 344 static __inline void *
 345 tcp_next(struct tcphdr *tcphdr)
 346 {
 347         char *p = (char *)tcphdr;
 348         return (&p[tcphdr->th_off * 4]);
 349 }
 350 #endif
 351
 352 #if defined(_NETINET_UDP_H_)
 353 static __inline void *
 354 udp_next(struct udphdr *udphdr)
 355 {
 356         return ((void *)(udphdr + 1));
 357 }
 358 #endif
 359
 360 #endif                          /* !_ALIAS_LOCAL_H_ */