alias_local.h revision 147623
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: head/sys/netinet/libalias/alias_local.h 147623 2005-06-27 07:36:02Z glebius $
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/queue.h>
50
51/* Use kernel allocator. */
52#if defined(_KERNEL) && defined(_SYS_MALLOC_H_)
53MALLOC_DECLARE(M_ALIAS);
54#define	malloc(x)	malloc(x, M_ALIAS, M_NOWAIT|M_ZERO)
55#define	calloc(x, n)	malloc(x*n)
56#define	free(x)		free(x, M_ALIAS)
57#endif
58
59/* XXX: LibAliasSetTarget() uses this constant. */
60#ifdef _KERNEL
61#define	INADDR_NONE	0xffffffff
62#endif
63
64/* Sizes of input and output link tables */
65#define LINK_TABLE_OUT_SIZE         101
66#define LINK_TABLE_IN_SIZE         4001
67
68struct proxy_entry;
69
70struct libalias {
71	LIST_ENTRY(libalias) instancelist;
72
73	int		packetAliasMode;	/* Mode flags                      */
74	/* - documented in alias.h  */
75
76	struct in_addr	aliasAddress;	/* Address written onto source     */
77	/* field of IP packet.           */
78
79	struct in_addr	targetAddress;	/* IP address incoming packets     */
80	/* are sent to if no aliasing    */
81	/* link already exists           */
82
83	struct in_addr	nullAddress;	/* Used as a dummy parameter for   */
84	/* some function calls           */
85
86			LIST_HEAD     (, alias_link) linkTableOut[LINK_TABLE_OUT_SIZE];
87	/* Lookup table of pointers to     */
88	/* chains of link records. Each  */
89
90			LIST_HEAD     (, alias_link) linkTableIn[LINK_TABLE_IN_SIZE];
91	/* link record is doubly indexed */
92	/* into input and output lookup  */
93	/* tables.                       */
94
95	/* Link statistics                 */
96	int		icmpLinkCount;
97	int		udpLinkCount;
98	int		tcpLinkCount;
99	int		pptpLinkCount;
100	int		protoLinkCount;
101	int		fragmentIdLinkCount;
102	int		fragmentPtrLinkCount;
103	int		sockCount;
104
105	int		cleanupIndex;	/* Index to chain of link table    */
106	/* being inspected for old links   */
107
108	int		timeStamp;	/* System time in seconds for      */
109	/* current packet                  */
110
111	int		lastCleanupTime;	/* Last time
112						 * IncrementalCleanup()  */
113	/* was called                      */
114
115	int		houseKeepingResidual;	/* used by HouseKeeping()          */
116
117	int		deleteAllLinks;	/* If equal to zero, DeleteLink()  */
118	/* will not remove permanent links */
119#ifndef	NO_LOGGING
120	FILE           *monitorFile;	/* File descriptor for link        */
121#endif
122	/* statistics monitoring file      */
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
151};
152
153/* Macros */
154
155/*
156 * The following macro is used to update an
157 * internet checksum.  "delta" is a 32-bit
158 * accumulation of all the changes to the
159 * checksum (adding in new 16-bit words and
160 * subtracting out old words), and "cksum"
161 * is the checksum value to be updated.
162 */
163#define	ADJUST_CHECKSUM(acc, cksum) \
164	do { \
165		acc += cksum; \
166		if (acc < 0) { \
167			acc = -acc; \
168			acc = (acc >> 16) + (acc & 0xffff); \
169			acc += acc >> 16; \
170			cksum = (u_short) ~acc; \
171		} else { \
172			acc = (acc >> 16) + (acc & 0xffff); \
173			acc += acc >> 16; \
174			cksum = (u_short) acc; \
175		} \
176	} while (0)
177
178
179/* Prototypes */
180
181/*
182 * We do not calculate TCP checksums when libalias is a kernel
183 * module, since it has no idea about checksum offloading.
184 * If TCP data has changed, then we just set checksum to zero,
185 * and caller must recalculate it himself.
186 * In case if libalias will edit UDP data, the same approach
187 * should be used.
188 */
189#ifndef _KERNEL
190u_short		IpChecksum(struct ip *_pip);
191u_short		TcpChecksum(struct ip *_pip);
192#endif
193void
194DifferentialChecksum(u_short * _cksum, void * _new, void * _old, int _n);
195
196/* Internal data access */
197struct alias_link *
198FindIcmpIn(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr,
199    u_short _id_alias, int _create);
200struct alias_link *
201FindIcmpOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr,
202    u_short _id, int _create);
203struct alias_link *
204FindFragmentIn1(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr,
205    u_short _ip_id);
206struct alias_link *
207FindFragmentIn2(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr,
208    u_short _ip_id);
209struct alias_link *
210		AddFragmentPtrLink(struct libalias *la, struct in_addr _dst_addr, u_short _ip_id);
211struct alias_link *
212		FindFragmentPtr(struct libalias *la, struct in_addr _dst_addr, u_short _ip_id);
213struct alias_link *
214FindProtoIn(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr,
215    u_char _proto);
216struct alias_link *
217FindProtoOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr,
218    u_char _proto);
219struct alias_link *
220FindUdpTcpIn(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr,
221    u_short _dst_port, u_short _alias_port, u_char _proto, int _create);
222struct alias_link *
223FindUdpTcpOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr,
224    u_short _src_port, u_short _dst_port, u_char _proto, int _create);
225struct alias_link *
226AddPptp(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr,
227    struct in_addr _alias_addr, u_int16_t _src_call_id);
228struct alias_link *
229FindPptpOutByCallId(struct libalias *la, struct in_addr _src_addr,
230    struct in_addr _dst_addr, u_int16_t _src_call_id);
231struct alias_link *
232FindPptpInByCallId(struct libalias *la, struct in_addr _dst_addr,
233    struct in_addr _alias_addr, u_int16_t _dst_call_id);
234struct alias_link *
235FindPptpOutByPeerCallId(struct libalias *la, struct in_addr _src_addr,
236    struct in_addr _dst_addr, u_int16_t _dst_call_id);
237struct alias_link *
238FindPptpInByPeerCallId(struct libalias *la, struct in_addr _dst_addr,
239    struct in_addr _alias_addr, u_int16_t _alias_call_id);
240struct alias_link *
241FindRtspOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr,
242    u_short _src_port, u_short _alias_port, u_char _proto);
243struct in_addr
244		FindOriginalAddress(struct libalias *la, struct in_addr _alias_addr);
245struct in_addr
246		FindAliasAddress(struct libalias *la, struct in_addr _original_addr);
247
248/* External data access/modification */
249int
250FindNewPortGroup(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr,
251    u_short _src_port, u_short _dst_port, u_short _port_count,
252    u_char _proto, u_char _align);
253void		GetFragmentAddr(struct alias_link *_lnk, struct in_addr *_src_addr);
254void		SetFragmentAddr(struct alias_link *_lnk, struct in_addr _src_addr);
255void		GetFragmentPtr(struct alias_link *_lnk, char **_fptr);
256void		SetFragmentPtr(struct alias_link *_lnk, char *fptr);
257void		SetStateIn(struct alias_link *_lnk, int _state);
258void		SetStateOut(struct alias_link *_lnk, int _state);
259int		GetStateIn (struct alias_link *_lnk);
260int		GetStateOut(struct alias_link *_lnk);
261struct in_addr
262		GetOriginalAddress(struct alias_link *_lnk);
263struct in_addr
264		GetDestAddress(struct alias_link *_lnk);
265struct in_addr
266		GetAliasAddress(struct alias_link *_lnk);
267struct in_addr
268		GetDefaultAliasAddress(struct libalias *la);
269void		SetDefaultAliasAddress(struct libalias *la, struct in_addr _alias_addr);
270u_short		GetOriginalPort(struct alias_link *_lnk);
271u_short		GetAliasPort(struct alias_link *_lnk);
272struct in_addr
273		GetProxyAddress(struct alias_link *_lnk);
274void		SetProxyAddress(struct alias_link *_lnk, struct in_addr _addr);
275u_short		GetProxyPort(struct alias_link *_lnk);
276void		SetProxyPort(struct alias_link *_lnk, u_short _port);
277void		SetAckModified(struct alias_link *_lnk);
278int		GetAckModified(struct alias_link *_lnk);
279int		GetDeltaAckIn(struct ip *_pip, struct alias_link *_lnk);
280int		GetDeltaSeqOut(struct ip *_pip, struct alias_link *_lnk);
281void		AddSeq    (struct ip *_pip, struct alias_link *_lnk, int _delta);
282void		SetExpire (struct alias_link *_lnk, int _expire);
283void		ClearCheckNewLink(struct libalias *la);
284void		SetProtocolFlags(struct alias_link *_lnk, int _pflags);
285int		GetProtocolFlags(struct alias_link *_lnk);
286void		SetDestCallId(struct alias_link *_lnk, u_int16_t _cid);
287
288#ifndef NO_FW_PUNCH
289void		PunchFWHole(struct alias_link *_lnk);
290
291#endif
292
293/* Housekeeping function */
294void		HouseKeeping(struct libalias *);
295
296/* Tcp specfic routines */
297/* lint -save -library Suppress flexelint warnings */
298
299/* FTP routines */
300void
301AliasHandleFtpOut(struct libalias *la, struct ip *_pip, struct alias_link *_lnk,
302    int _maxpacketsize);
303
304/* IRC routines */
305void
306AliasHandleIrcOut(struct libalias *la, struct ip *_pip, struct alias_link *_lnk,
307    int _maxsize);
308
309/* RTSP routines */
310void
311AliasHandleRtspOut(struct libalias *la, struct ip *_pip, struct alias_link *_lnk,
312    int _maxpacketsize);
313
314/* PPTP routines */
315void		AliasHandlePptpOut(struct libalias *la, struct ip *_pip, struct alias_link *_lnk);
316void		AliasHandlePptpIn(struct libalias *la, struct ip *_pip, struct alias_link *_lnk);
317int		AliasHandlePptpGreOut(struct libalias *la, struct ip *_pip);
318int		AliasHandlePptpGreIn(struct libalias *la, struct ip *_pip);
319
320/* NetBIOS routines */
321int
322AliasHandleUdpNbt(struct libalias *la, struct ip *_pip, struct alias_link *_lnk,
323    struct in_addr *_alias_address, u_short _alias_port);
324int
325AliasHandleUdpNbtNS(struct libalias *la, struct ip *_pip, struct alias_link *_lnk,
326    struct in_addr *_alias_address, u_short * _alias_port,
327    struct in_addr *_original_address, u_short * _original_port);
328
329/* CUSeeMe routines */
330void		AliasHandleCUSeeMeOut(struct libalias *la, struct ip *_pip, struct alias_link *_lnk);
331void		AliasHandleCUSeeMeIn(struct libalias *la, struct ip *_pip, struct in_addr _original_addr);
332
333/* Skinny routines */
334void		AliasHandleSkinny(struct libalias *la, struct ip *_pip, struct alias_link *_lnk);
335
336/* Transparent proxy routines */
337int
338ProxyCheck(struct libalias *la, struct ip *_pip, struct in_addr *_proxy_server_addr,
339    u_short * _proxy_server_port);
340void
341ProxyModify(struct libalias *la, struct alias_link *_lnk, struct ip *_pip,
342    int _maxpacketsize, int _proxy_type);
343
344enum alias_tcp_state {
345	ALIAS_TCP_STATE_NOT_CONNECTED,
346	ALIAS_TCP_STATE_CONNECTED,
347	ALIAS_TCP_STATE_DISCONNECTED
348};
349
350#if defined(_NETINET_IP_H_)
351static __inline void *
352ip_next(struct ip *iphdr)
353{
354	char *p = (char *)iphdr;
355	return (&p[iphdr->ip_hl * 4]);
356}
357#endif
358
359#if defined(_NETINET_TCP_H_)
360static __inline void *
361tcp_next(struct tcphdr *tcphdr)
362{
363	char *p = (char *)tcphdr;
364	return (&p[tcphdr->th_off * 4]);
365}
366#endif
367
368#if defined(_NETINET_UDP_H_)
369static __inline void *
370udp_next(struct udphdr *udphdr)
371{
372	return ((void *)(udphdr + 1));
373}
374#endif
375
376/*lint -restore */
377
378#endif				/* !_ALIAS_LOCAL_H_ */
379