2 * Copyright (c) 2001 Charles Mott <cm@linktel.net>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
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.
35 * This include file is intended to be used only within the aliasing
36 * software. Outside world interfaces are defined in alias.h
38 * This software is placed into the public domain with no restrictions
39 * on its distribution.
41 * Initial version: August, 1996 (cjm)
43 * <updated several times by original author and Eivind Eklund>
46 #ifndef _ALIAS_LOCAL_H_
47 #define _ALIAS_LOCAL_H_
49 #include <sys/types.h>
50 #include <sys/sysctl.h>
53 #include <sys/malloc.h>
54 #include <sys/param.h>
56 #include <sys/mutex.h>
58 /* XXX: LibAliasSetTarget() uses this constant. */
59 #define INADDR_NONE 0xffffffff
62 /* Sizes of input and output link tables */
63 #define LINK_TABLE_OUT_SIZE 4001
64 #define LINK_TABLE_IN_SIZE 4001
69 LIST_ENTRY(libalias) instancelist;
71 int packetAliasMode; /* Mode flags */
72 /* - documented in alias.h */
74 struct in_addr aliasAddress; /* Address written onto source */
75 /* field of IP packet. */
77 struct in_addr targetAddress; /* IP address incoming packets */
78 /* are sent to if no aliasing */
79 /* link already exists */
81 struct in_addr nullAddress; /* Used as a dummy parameter for */
82 /* some function calls */
84 LIST_HEAD (, alias_link) linkTableOut[LINK_TABLE_OUT_SIZE];
85 /* Lookup table of pointers to */
86 /* chains of link records. Each */
88 LIST_HEAD (, alias_link) linkTableIn[LINK_TABLE_IN_SIZE];
89 /* link record is doubly indexed */
90 /* into input and output lookup */
99 int fragmentIdLinkCount;
100 int fragmentPtrLinkCount;
103 int cleanupIndex; /* Index to chain of link table */
104 /* being inspected for old links */
106 int timeStamp; /* System time in seconds for */
109 int lastCleanupTime; /* Last time
110 * IncrementalCleanup() */
113 int deleteAllLinks; /* If equal to zero, DeleteLink() */
114 /* will not remove permanent links */
122 /* statistics monitoring */
124 int newDefaultLink; /* Indicates if a new aliasing */
125 /* link has been created after a */
126 /* call to PacketAliasIn/Out(). */
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 */
134 int fireWallBaseNum; /* The first firewall entry
135 * free for our use */
136 int fireWallNumNums; /* How many entries can we
138 int fireWallActiveNum; /* Which entry did we last
140 char *fireWallField; /* bool array for entries */
143 unsigned int skinnyPort; /* TCP port used by the Skinny */
146 struct proxy_entry *proxyList;
148 struct in_addr true_addr; /* in network byte order. */
149 u_short true_port; /* in host byte order. */
152 * avoid races in libalias: every public function has to use it.
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)
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)
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.
183 #define ADJUST_CHECKSUM(acc, cksum) \
188 acc = (acc >> 16) + (acc & 0xffff); \
190 cksum = (u_short) ~acc; \
192 acc = (acc >> 16) + (acc & 0xffff); \
194 cksum = (u_short) acc; \
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
210 u_short IpChecksum(struct ip *_pip);
211 u_short TcpChecksum(struct ip *_pip);
214 DifferentialChecksum(u_short * _cksum, void * _new, void * _old, int _n);
216 /* Internal data access */
218 FindIcmpIn(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr,
219 u_short _id_alias, int _create);
221 FindIcmpOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr,
222 u_short _id, int _create);
224 FindFragmentIn1(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr,
227 FindFragmentIn2(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr,
230 AddFragmentPtrLink(struct libalias *la, struct in_addr _dst_addr, u_short _ip_id);
232 FindFragmentPtr(struct libalias *la, struct in_addr _dst_addr, u_short _ip_id);
234 FindProtoIn(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr,
237 FindProtoOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr,
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);
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);
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);
249 FindPptpOutByCallId(struct libalias *la, struct in_addr _src_addr,
250 struct in_addr _dst_addr, u_int16_t _src_call_id);
252 FindPptpInByCallId(struct libalias *la, struct in_addr _dst_addr,
253 struct in_addr _alias_addr, u_int16_t _dst_call_id);
255 FindPptpOutByPeerCallId(struct libalias *la, struct in_addr _src_addr,
256 struct in_addr _dst_addr, u_int16_t _dst_call_id);
258 FindPptpInByPeerCallId(struct libalias *la, struct in_addr _dst_addr,
259 struct in_addr _alias_addr, u_int16_t _alias_call_id);
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);
264 FindOriginalAddress(struct libalias *la, struct in_addr _alias_addr);
266 FindAliasAddress(struct libalias *la, struct in_addr _original_addr);
268 /* External data access/modification */
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);
282 GetOriginalAddress(struct alias_link *_lnk);
284 GetDestAddress(struct alias_link *_lnk);
286 GetAliasAddress(struct alias_link *_lnk);
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);
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(struct ip *_pip, struct alias_link *_lnk);
300 int GetDeltaSeqOut(struct ip *_pip, struct alias_link *_lnk);
301 void AddSeq (struct ip *_pip, struct alias_link *_lnk, int _delta);
302 void SetExpire (struct alias_link *_lnk, int _expire);
303 void ClearCheckNewLink(struct libalias *la);
304 void SetProtocolFlags(struct alias_link *_lnk, int _pflags);
305 int GetProtocolFlags(struct alias_link *_lnk);
306 void SetDestCallId(struct alias_link *_lnk, u_int16_t _cid);
309 void PunchFWHole(struct alias_link *_lnk);
313 /* Housekeeping function */
314 void HouseKeeping(struct libalias *);
316 /* Tcp specfic routines */
317 /* lint -save -library Suppress flexelint warnings */
319 /* Transparent proxy routines */
321 ProxyCheck(struct libalias *la, struct ip *_pip, struct in_addr *_proxy_server_addr,
322 u_short * _proxy_server_port);
324 ProxyModify(struct libalias *la, struct alias_link *_lnk, struct ip *_pip,
325 int _maxpacketsize, int _proxy_type);
327 enum alias_tcp_state {
328 ALIAS_TCP_STATE_NOT_CONNECTED,
329 ALIAS_TCP_STATE_CONNECTED,
330 ALIAS_TCP_STATE_DISCONNECTED
333 #if defined(_NETINET_IP_H_)
334 static __inline void *
335 ip_next(struct ip *iphdr)
337 char *p = (char *)iphdr;
338 return (&p[iphdr->ip_hl * 4]);
342 #if defined(_NETINET_TCP_H_)
343 static __inline void *
344 tcp_next(struct tcphdr *tcphdr)
346 char *p = (char *)tcphdr;
347 return (&p[tcphdr->th_off * 4]);
351 #if defined(_NETINET_UDP_H_)
352 static __inline void *
353 udp_next(struct udphdr *udphdr)
355 return ((void *)(udphdr + 1));
359 #endif /* !_ALIAS_LOCAL_H_ */