alias_db.c@ 28023

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1	/*-
2	* Copyright (c) 2001 Charles Mott <[email protected]>
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
27	#ifndef VBOX
28	#include <sys/cdefs.h>
29	__FBSDID("$FreeBSD: src/sys/netinet/libalias/alias_db.c,v 1.71.2.2.4.1 2009/04/15 03:14:26 kensmith Exp $");
30	#endif
31	/*
32	Alias_db.c encapsulates all data structures used for storing
33	packet aliasing data. Other parts of the aliasing software
34	access data through functions provided in this file.
35
36	Data storage is based on the notion of a "link", which is
37	established for ICMP echo/reply packets, UDP datagrams and
38	TCP stream connections. A link stores the original source
39	and destination addresses. For UDP and TCP, it also stores
40	source and destination port numbers, as well as an alias
41	port number. Links are also used to store information about
42	fragments.
43
44	There is a facility for sweeping through and deleting old
45	links as new packets are sent through. A simple timeout is
46	used for ICMP and UDP links. TCP links are left alone unless
47	there is an incomplete connection, in which case the link
48	can be deleted after a certain amount of time.
49
50
51	Initial version: August, 1996 (cjm)
52
53	Version 1.4: September 16, 1996 (cjm)
54	Facility for handling incoming links added.
55
56	Version 1.6: September 18, 1996 (cjm)
57	ICMP data handling simplified.
58
59	Version 1.7: January 9, 1997 (cjm)
60	Fragment handling simplified.
61	Saves pointers for unresolved fragments.
62	Permits links for unspecified remote ports
63	or unspecified remote addresses.
64	Fixed bug which did not properly zero port
65	table entries after a link was deleted.
66	Cleaned up some obsolete comments.
67
68	Version 1.8: January 14, 1997 (cjm)
69	Fixed data type error in StartPoint().
70	(This error did not exist prior to v1.7
71	and was discovered and fixed by Ari Suutari)
72
73	Version 1.9: February 1, 1997
74	Optionally, connections initiated from packet aliasing host
75	machine will will not have their port number aliased unless it
76	conflicts with an aliasing port already being used. (cjm)
77
78	All options earlier being #ifdef'ed are now available through
79	a new interface, SetPacketAliasMode(). This allows run time
80	control (which is now available in PPP+pktAlias through the
81	'alias' keyword). (ee)
82
83	Added ability to create an alias port without
84	either destination address or port specified.
85	port type = ALIAS_PORT_UNKNOWN_DEST_ALL (ee)
86
87	Removed K&R style function headers
88	and general cleanup. (ee)
89
90	Added packetAliasMode to replace compiler #defines's (ee)
91
92	Allocates sockets for partially specified
93	ports if ALIAS_USE_SOCKETS defined. (cjm)
94
95	Version 2.0: March, 1997
96	SetAliasAddress() will now clean up alias links
97	if the aliasing address is changed. (cjm)
98
99	PacketAliasPermanentLink() function added to support permanent
100	links. (J. Fortes suggested the need for this.)
101	Examples:
102
103	(192.168.0.1, port 23) <-> alias port 6002, unknown dest addr/port
104
105	(192.168.0.2, port 21) <-> alias port 3604, known dest addr
106	unknown dest port
107
108	These permanent links allow for incoming connections to
109	machines on the local network. They can be given with a
110	user-chosen amount of specificity, with increasing specificity
111	meaning more security. (cjm)
112
113	Quite a bit of rework to the basic engine. The portTable[]
114	array, which kept track of which ports were in use was replaced
115	by a table/linked list structure. (cjm)
116
117	SetExpire() function added. (cjm)
118
119	DeleteLink() no longer frees memory association with a pointer
120	to a fragment (this bug was first recognized by E. Eklund in
121	v1.9).
122
123	Version 2.1: May, 1997 (cjm)
124	Packet aliasing engine reworked so that it can handle
125	multiple external addresses rather than just a single
126	host address.
127
128	PacketAliasRedirectPort() and PacketAliasRedirectAddr()
129	added to the API. The first function is a more generalized
130	version of PacketAliasPermanentLink(). The second function
131	implements static network address translation.
132
133	Version 3.2: July, 2000 (salander and satoh)
134	Added FindNewPortGroup to get contiguous range of port values.
135
136	Added QueryUdpTcpIn and QueryUdpTcpOut to look for an aliasing
137	link but not actually add one.
138
139	Added FindRtspOut, which is closely derived from FindUdpTcpOut,
140	except that the alias port (from FindNewPortGroup) is provided
141	as input.
142
143	See HISTORY file for additional revisions.
144	*/
145
146	#ifndef VBOX
147	#ifdef _KERNEL
148	#include <machine/stdarg.h>
149	#include <sys/param.h>
150	#include <sys/kernel.h>
151	#include <sys/module.h>
152	#include <sys/syslog.h>
153	#else
154	#include <stdarg.h>
155	#include <stdlib.h>
156	#include <stdio.h>
157	#include <sys/errno.h>
158	#include <sys/time.h>
159	#include <unistd.h>
160	#endif
161
162	#include <sys/socket.h>
163	#include <netinet/tcp.h>
164
165	#ifdef _KERNEL
166	#include <netinet/libalias/alias.h>
167	#include <netinet/libalias/alias_local.h>
168	#include <netinet/libalias/alias_mod.h>
169	#include <net/if.h>
170	#else
171	#include "alias.h"
172	#include "alias_local.h"
173	#include "alias_mod.h"
174	#endif
175	#else /* !VBOX */
176	# include <iprt/assert.h>
177	# include "alias.h"
178	# include "alias_local.h"
179	# include "alias_mod.h"
180	# include <slirp.h>
181	#endif /* VBOX */
182
183	#ifndef VBOX
184	static LIST_HEAD(, libalias) instancehead = LIST_HEAD_INITIALIZER(instancehead);
185	#endif
186
187
188	/*
189	Constants (note: constants are also defined
190	near relevant functions or structs)
191	*/
192
193	/* Parameters used for cleanup of expired links */
194	/* NOTE: ALIAS_CLEANUP_INTERVAL_SECS must be less then LINK_TABLE_OUT_SIZE */
195	#define ALIAS_CLEANUP_INTERVAL_SECS 64
196	#define ALIAS_CLEANUP_MAX_SPOKES (LINK_TABLE_OUT_SIZE/5)
197
198	/* Timeouts (in seconds) for different link types */
199	#define ICMP_EXPIRE_TIME 60
200	#define UDP_EXPIRE_TIME 60
201	#define PROTO_EXPIRE_TIME 60
202	#define FRAGMENT_ID_EXPIRE_TIME 10
203	#define FRAGMENT_PTR_EXPIRE_TIME 30
204
205	/* TCP link expire time for different cases */
206	/* When the link has been used and closed - minimal grace time to
207	allow ACKs and potential re-connect in FTP (XXX - is this allowed?) */
208	#ifndef TCP_EXPIRE_DEAD
209	#define TCP_EXPIRE_DEAD 10
210	#endif
211
212	/* When the link has been used and closed on one side - the other side
213	is allowed to still send data */
214	#ifndef TCP_EXPIRE_SINGLEDEAD
215	#define TCP_EXPIRE_SINGLEDEAD 90
216	#endif
217
218	/* When the link isn't yet up */
219	#ifndef TCP_EXPIRE_INITIAL
220	#define TCP_EXPIRE_INITIAL 300
221	#endif
222
223	/* When the link is up */
224	#ifndef TCP_EXPIRE_CONNECTED
225	#define TCP_EXPIRE_CONNECTED 86400
226	#endif
227
228
229	/* Dummy port number codes used for FindLinkIn/Out() and AddLink().
230	These constants can be anything except zero, which indicates an
231	unknown port number. */
232
233	#define NO_DEST_PORT 1
234	#define NO_SRC_PORT 1
235
236
237
238	/* Data Structures
239
240	The fundamental data structure used in this program is
241	"struct alias_link". Whenever a TCP connection is made,
242	a UDP datagram is sent out, or an ICMP echo request is made,
243	a link record is made (if it has not already been created).
244	The link record is identified by the source address/port
245	and the destination address/port. In the case of an ICMP
246	echo request, the source port is treated as being equivalent
247	with the 16-bit ID number of the ICMP packet.
248
249	The link record also can store some auxiliary data. For
250	TCP connections that have had sequence and acknowledgment
251	modifications, data space is available to track these changes.
252	A state field is used to keep track in changes to the TCP
253	connection state. ID numbers of fragments can also be
254	stored in the auxiliary space. Pointers to unresolved
255	fragments can also be stored.
256
257	The link records support two independent chainings. Lookup
258	tables for input and out tables hold the initial pointers
259	the link chains. On input, the lookup table indexes on alias
260	port and link type. On output, the lookup table indexes on
261	source address, destination address, source port, destination
262	port and link type.
263	*/
264
265	struct ack_data_record { /* used to save changes to ACK/sequence
266	* numbers */
267	u_long ack_old;
268	u_long ack_new;
269	int delta;
270	int active;
271	};
272
273	struct tcp_state { /* Information about TCP connection */
274	int in; /* State for outside -> inside */
275	int out; /* State for inside -> outside */
276	int index; /* Index to ACK data array */
277	int ack_modified; /* Indicates whether ACK and
278	* sequence numbers */
279	/* been modified */
280	};
281
282	#define N_LINK_TCP_DATA 3 /* Number of distinct ACK number changes
283	* saved for a modified TCP stream */
284	struct tcp_dat {
285	struct tcp_state state;
286	struct ack_data_record ack[N_LINK_TCP_DATA];
287	int fwhole; /* Which firewall record is used for this
288	* hole? */
289	};
290
291	struct server { /* LSNAT server pool (circular list) */
292	struct in_addr addr;
293	u_short port;
294	struct server *next;
295	};
296
297	struct alias_link { /* Main data structure */
298	struct libalias *la;
299	struct in_addr src_addr; /* Address and port information */
300	struct in_addr dst_addr;
301	struct in_addr alias_addr;
302	struct in_addr proxy_addr;
303	u_short src_port;
304	u_short dst_port;
305	u_short alias_port;
306	u_short proxy_port;
307	struct server *server;
308
309	int link_type; /* Type of link: TCP, UDP, ICMP,
310	* proto, frag */
311
312	/* values for link_type */
313	#define LINK_ICMP IPPROTO_ICMP
314	#define LINK_UDP IPPROTO_UDP
315	#define LINK_TCP IPPROTO_TCP
316	#define LINK_FRAGMENT_ID (IPPROTO_MAX + 1)
317	#define LINK_FRAGMENT_PTR (IPPROTO_MAX + 2)
318	#define LINK_ADDR (IPPROTO_MAX + 3)
319	#define LINK_PPTP (IPPROTO_MAX + 4)
320
321	int flags; /* indicates special characteristics */
322	int pflags; /* protocol-specific flags */
323
324	/* flag bits */
325	#define LINK_UNKNOWN_DEST_PORT 0x01
326	#define LINK_UNKNOWN_DEST_ADDR 0x02
327	#define LINK_PERMANENT 0x04
328	#define LINK_PARTIALLY_SPECIFIED 0x03 /* logical-or of first two bits */
329	#define LINK_UNFIREWALLED 0x08
330
331	#ifndef VBOX
332	int timestamp; /* Time link was last accessed */
333	int expire_time; /* Expire time for link */
334	#else
335	unsigned int timestamp; /* Time link was last accessed */
336	unsigned int expire_time; /* Expire time for link */
337	#endif
338
339	#ifndef NO_USE_SOCKETS
340	# ifndef VBOX
341	/*
342	* in VBox we do not use host's sockets here, which are managed
343	* inside slirp. yes we have to create new sockets here but latter
344	* managment and deletion are in repsponsible of Slirp.
345	*/
346	int sockfd; /* socket descriptor */
347	# endif
348	#endif
349	LIST_ENTRY (alias_link) list_out; /* Linked list of
350	* pointers for */
351	LIST_ENTRY (alias_link) list_in; /* input and output
352	* lookup tables */
353
354	union { /* Auxiliary data */
355	char *frag_ptr;
356	struct in_addr frag_addr;
357	struct tcp_dat *tcp;
358	} data;
359	};
360
361	/* Clean up procedure. */
362	#ifndef VBOX
363	static void finishoff(void);
364	#endif
365
366	/* Kernel module definition. */
367	#ifdef _KERNEL
368	MALLOC_DEFINE(M_ALIAS, "libalias", "packet aliasing");
369
370	MODULE_VERSION(libalias, 1);
371
372	static int
373	alias_mod_handler(module_t mod, int type, void *data)
374	{
375	int error;
376
377	switch (type) {
378	case MOD_LOAD:
379	error = 0;
380	handler_chain_init();
381	break;
382	case MOD_QUIESCE:
383	case MOD_UNLOAD:
384	handler_chain_destroy();
385	finishoff();
386	error = 0;
387	break;
388	default:
389	error = EINVAL;
390	}
391
392	return (error);
393	}
394
395	static moduledata_t alias_mod = {
396	"alias", alias_mod_handler, NULL
397	};
398
399	DECLARE_MODULE(alias, alias_mod, SI_SUB_DRIVERS, SI_ORDER_SECOND);
400	#endif
401
402	/* Internal utility routines (used only in alias_db.c)
403
404	Lookup table starting points:
405	StartPointIn() -- link table initial search point for
406	incoming packets
407	StartPointOut() -- link table initial search point for
408	outgoing packets
409
410	Miscellaneous:
411	SeqDiff() -- difference between two TCP sequences
412	ShowAliasStats() -- send alias statistics to a monitor file
413	*/
414
415
416	/* Local prototypes */
417	static u_int StartPointIn(struct in_addr, u_short, int);
418
419	static u_int
420	StartPointOut(struct in_addr, struct in_addr,
421	u_short, u_short, int);
422
423	static int SeqDiff(u_long, u_long);
424
425	#ifndef NO_FW_PUNCH
426	/* Firewall control */
427	static void InitPunchFW(struct libalias *);
428	static void UninitPunchFW(struct libalias *);
429	static void ClearFWHole(struct alias_link *);
430
431	#endif
432
433	/* Log file control */
434	static void ShowAliasStats(struct libalias *);
435	static int InitPacketAliasLog(struct libalias *);
436	static void UninitPacketAliasLog(struct libalias *);
437
438	static u_int
439	StartPointIn(struct in_addr alias_addr,
440	u_short alias_port,
441	int link_type)
442	{
443	u_int n;
444
445	n = alias_addr.s_addr;
446	if (link_type != LINK_PPTP)
447	n += alias_port;
448	n += link_type;
449	return (n % LINK_TABLE_IN_SIZE);
450	}
451
452
453	static u_int
454	StartPointOut(struct in_addr src_addr, struct in_addr dst_addr,
455	u_short src_port, u_short dst_port, int link_type)
456	{
457	u_int n;
458
459	n = src_addr.s_addr;
460	n += dst_addr.s_addr;
461	if (link_type != LINK_PPTP) {
462	n += src_port;
463	n += dst_port;
464	}
465	n += link_type;
466
467	return (n % LINK_TABLE_OUT_SIZE);
468	}
469
470
471	static int
472	SeqDiff(u_long x, u_long y)
473	{
474	/* Return the difference between two TCP sequence numbers */
475
476	/*
477	This function is encapsulated in case there are any unusual
478	arithmetic conditions that need to be considered.
479	*/
480
481	return (ntohl(y) - ntohl(x));
482	}
483
484	#ifdef _KERNEL
485
486	static void
487	AliasLog(char str, const char format, ...)
488	{
489	va_list ap;
490
491	va_start(ap, format);
492	vsnprintf(str, LIBALIAS_BUF_SIZE, format, ap);
493	va_end(ap);
494	}
495	#else
496	static void
497	AliasLog(FILE stream, const char format, ...)
498	{
499	# ifndef VBOX
500	va_list ap;
501
502	va_start(ap, format);
503	vfprintf(stream, format, ap);
504	va_end(ap);
505	fflush(stream);
506	# else
507
508	va_list args;
509	char buffer[1024];
510	memset(buffer, 0, 1024);
511	va_start(args, format);
512	RTStrPrintfV(buffer, 1024, format, args);
513	va_end(args);
514	/make it grepable /
515	Log2(("NAT:ALIAS: %s\n", buffer));
516	# endif
517	}
518	#endif
519
520	static void
521	ShowAliasStats(struct libalias *la)
522	{
523
524	LIBALIAS_LOCK_ASSERT(la);
525	/* Used for debugging */
526	if (la->logDesc) {
527	int tot = la->icmpLinkCount + la->udpLinkCount +
528	la->tcpLinkCount + la->pptpLinkCount +
529	la->protoLinkCount + la->fragmentIdLinkCount +
530	la->fragmentPtrLinkCount;
531
532	AliasLog(la->logDesc,
533	"icmp=%u, udp=%u, tcp=%u, pptp=%u, proto=%u, frag_id=%u frag_ptr=%u / tot=%u",
534	la->icmpLinkCount,
535	la->udpLinkCount,
536	la->tcpLinkCount,
537	la->pptpLinkCount,
538	la->protoLinkCount,
539	la->fragmentIdLinkCount,
540	la->fragmentPtrLinkCount, tot);
541	#ifndef _KERNEL
542	AliasLog(la->logDesc, " (sock=%u)\n", la->sockCount);
543	#endif
544	}
545	}
546
547	/* Internal routines for finding, deleting and adding links
548
549	Port Allocation:
550	GetNewPort() -- find and reserve new alias port number
551	GetSocket() -- try to allocate a socket for a given port
552
553	Link creation and deletion:
554	CleanupAliasData() - remove all link chains from lookup table
555	IncrementalCleanup() - look for stale links in a single chain
556	DeleteLink() - remove link
557	AddLink() - add link
558	ReLink() - change link
559
560	Link search:
561	FindLinkOut() - find link for outgoing packets
562	FindLinkIn() - find link for incoming packets
563
564	Port search:
565	FindNewPortGroup() - find an available group of ports
566	*/
567
568	/* Local prototypes */
569	static int GetNewPort(struct libalias , struct alias_link , int);
570	#ifndef NO_USE_SOCKETS
571	static u_short GetSocket(struct libalias , u_short, int , int);
572	#endif
573	static void CleanupAliasData(struct libalias *);
574
575	static void IncrementalCleanup(struct libalias *);
576
577	static void DeleteLink(struct alias_link *);
578
579	static struct alias_link *
580	AddLink(struct libalias *, struct in_addr, struct in_addr, struct in_addr,
581	u_short, u_short, int, int);
582
583	static struct alias_link *
584	ReLink(struct alias_link *,
585	struct in_addr, struct in_addr, struct in_addr,
586	u_short, u_short, int, int);
587
588	static struct alias_link *
589	FindLinkOut (struct libalias *, struct in_addr, struct in_addr, u_short, u_short, int, int);
590
591	static struct alias_link *
592	FindLinkIn (struct libalias *, struct in_addr, struct in_addr, u_short, u_short, int, int);
593
594
595	#define ALIAS_PORT_BASE 0x08000
596	#define ALIAS_PORT_MASK 0x07fff
597	#define ALIAS_PORT_MASK_EVEN 0x07ffe
598	#define GET_NEW_PORT_MAX_ATTEMPTS 20
599
600	#define GET_ALIAS_PORT -1
601	#define GET_ALIAS_ID GET_ALIAS_PORT
602
603	#define FIND_EVEN_ALIAS_BASE 1
604
605	/* GetNewPort() allocates port numbers. Note that if a port number
606	is already in use, that does not mean that it cannot be used by
607	another link concurrently. This is because GetNewPort() looks for
608	unused triplets: (dest addr, dest port, alias port). */
609
610	static int
611	GetNewPort(struct libalias la, struct alias_link lnk, int alias_port_param)
612	{
613	int i;
614	int max_trials;
615	u_short port_sys;
616	u_short port_net;
617
618	LIBALIAS_LOCK_ASSERT(la);
619	/*
620	Description of alias_port_param for GetNewPort(). When
621	this parameter is zero or positive, it precisely specifies
622	the port number. GetNewPort() will return this number
623	without check that it is in use.
624
625	When this parameter is GET_ALIAS_PORT, it indicates to get a randomly
626	selected port number.
627	*/
628
629	if (alias_port_param == GET_ALIAS_PORT) {
630	/*
631	* The aliasing port is automatically selected by one of
632	* two methods below:
633	*/
634	max_trials = GET_NEW_PORT_MAX_ATTEMPTS;
635
636	if (la->packetAliasMode & PKT_ALIAS_SAME_PORTS) {
637	/*
638	* When the PKT_ALIAS_SAME_PORTS option is chosen,
639	* the first try will be the actual source port. If
640	* this is already in use, the remainder of the
641	* trials will be random.
642	*/
643	port_net = lnk->src_port;
644	port_sys = ntohs(port_net);
645	} else {
646	/* First trial and all subsequent are random. */
647	port_sys = arc4random() & ALIAS_PORT_MASK;
648	port_sys += ALIAS_PORT_BASE;
649	port_net = htons(port_sys);
650	}
651	} else if (alias_port_param >= 0 && alias_port_param < 0x10000) {
652	lnk->alias_port = (u_short) alias_port_param;
653	return (0);
654	} else {
655	#ifdef LIBALIAS_DEBUG
656	fprintf(stderr, "PacketAlias/GetNewPort(): ");
657	fprintf(stderr, "input parameter error\n");
658	#endif
659	return (-1);
660	}
661
662
663	/* Port number search */
664	for (i = 0; i < max_trials; i++) {
665	int go_ahead;
666	struct alias_link *search_result;
667
668	search_result = FindLinkIn(la, lnk->dst_addr, lnk->alias_addr,
669	lnk->dst_port, port_net,
670	lnk->link_type, 0);
671
672	if (search_result == NULL)
673	go_ahead = 1;
674	else if (!(lnk->flags & LINK_PARTIALLY_SPECIFIED)
675	&& (search_result->flags & LINK_PARTIALLY_SPECIFIED))
676	go_ahead = 1;
677	else
678	go_ahead = 0;
679
680	if (go_ahead) {
681	#ifndef NO_USE_SOCKETS
682	if ((la->packetAliasMode & PKT_ALIAS_USE_SOCKETS)
683	&& (lnk->flags & LINK_PARTIALLY_SPECIFIED)
684	&& ((lnk->link_type == LINK_TCP) \|\|
685	(lnk->link_type == LINK_UDP))) {
686	#ifndef VBOX
687	if (GetSocket(la, port_net, &lnk->sockfd, lnk->link_type)) {
688	#else
689	if (GetSocket(la, port_net, NULL, lnk->link_type)) {
690	#endif
691	lnk->alias_port = port_net;
692	return (0);
693	}
694	} else {
695	#endif
696	lnk->alias_port = port_net;
697	return (0);
698	#ifndef NO_USE_SOCKETS
699	}
700	#endif
701	}
702	port_sys = arc4random() & ALIAS_PORT_MASK;
703	port_sys += ALIAS_PORT_BASE;
704	port_net = htons(port_sys);
705	}
706
707	#ifdef LIBALIAS_DEBUG
708	fprintf(stderr, "PacketAlias/GetnewPort(): ");
709	fprintf(stderr, "could not find free port\n");
710	#endif
711
712	return (-1);
713	}
714
715	#ifndef NO_USE_SOCKETS
716	static u_short
717	GetSocket(struct libalias la, u_short port_net, int sockfd, int link_type)
718	{
719	int err;
720	int sock;
721	struct sockaddr_in sock_addr;
722	#ifdef VBOX
723	int opt = 1;
724	int status = 0;
725	struct socket *so = NULL;
726	struct sockaddr sa_addr;
727	socklen_t socklen = sizeof(struct sockaddr);
728	#endif
729
730	LIBALIAS_LOCK_ASSERT(la);
731	#ifdef VBOX
732	so = socreate();
733	if (so == NULL)
734	{
735	return 0;
736	}
737	#endif
738	if (link_type == LINK_TCP)
739	sock = socket(AF_INET, SOCK_STREAM, 0);
740	else if (link_type == LINK_UDP)
741	sock = socket(AF_INET, SOCK_DGRAM, 0);
742	else {
743	#ifdef LIBALIAS_DEBUG
744	fprintf(stderr, "PacketAlias/GetSocket(): ");
745	fprintf(stderr, "incorrect link type\n");
746	#endif
747	#ifdef VBOX
748	RTMemFree(so);
749	#endif
750	return (0);
751	}
752
753	if (sock < 0) {
754	#ifdef LIBALIAS_DEBUG
755	fprintf(stderr, "PacketAlias/GetSocket(): ");
756	# ifndef VBOX
757	fprintf(stderr, "socket() error %d\n", *sockfd);
758	# else
759	fprintf(stderr, "socket() error %d\n", errno);
760	# endif
761	#endif
762	return (0);
763	}
764	#ifdef VBOX
765	so->s = sock;
766	fd_nonblock(so->s);
767	#endif
768	memset(&sock_addr, 0, sizeof(struct sockaddr_in));
769	sock_addr.sin_family = AF_INET;
770	sock_addr.sin_addr.s_addr = htonl(INADDR_ANY);
771	sock_addr.sin_port = htons(port_net);
772	#ifdef RT_OS_DARWIN
773	sock_addr.sin_len = sizeof(struct sockaddr_in);
774	#endif
775
776	err = bind(sock,
777	(struct sockaddr *)&sock_addr,
778	sizeof(sock_addr));
779	if (err == 0) {
780	la->sockCount++;
781	#ifdef VBOX
782	so->so_expire = la->curtime + SO_EXPIRE;
783	setsockopt(so->s, SOL_SOCKET, SO_BROADCAST,
784	(const char *)&opt, sizeof(opt));
785	status = getsockname(so->s, &sa_addr, &socklen);
786	if (status != 0 \|\| sa_addr.sa_family != AF_INET)
787	{
788	closesocket(so->s);
789	RTMemFree(so);
790	return 0;
791	}
792	so->so_hlport = ((struct sockaddr_in *)&sa_addr)->sin_port;
793	so->so_hladdr.s_addr =
794	((struct sockaddr_in *)&sa_addr)->sin_addr.s_addr;
795	NSOCK_INC_EX(la);
796	if (link_type == LINK_TCP)
797	{
798	insque(la->pData, so, &la->tcb);
799	}
800	else if (link_type == LINK_UDP)
801	{
802	insque(la->pData, so, &la->udb);
803	}
804	else {
805	Assert(!"Shouldn't be here");
806	}
807
808	#else
809	*sockfd = sock;
810	#endif
811	return (1);
812	} else {
813	#ifdef VBOX
814	if (sock >= 0)
815	closesocket(sock);
816	/* socket wasn't enqueued so we shouldn't use sofree */
817	RTMemFree(so);
818	#else
819	close(sock);
820	#endif
821	return (0);
822	}
823	}
824	#endif
825
826	/* FindNewPortGroup() returns a base port number for an available
827	range of contiguous port numbers. Note that if a port number
828	is already in use, that does not mean that it cannot be used by
829	another link concurrently. This is because FindNewPortGroup()
830	looks for unused triplets: (dest addr, dest port, alias port). */
831
832	int
833	FindNewPortGroup(struct libalias *la,
834	struct in_addr dst_addr,
835	struct in_addr alias_addr,
836	u_short src_port,
837	u_short dst_port,
838	u_short port_count,
839	u_char proto,
840	u_char align)
841	{
842	int i, j;
843	int max_trials;
844	u_short port_sys;
845	int link_type;
846
847	LIBALIAS_LOCK_ASSERT(la);
848	/*
849	* Get link_type from protocol
850	*/
851
852	switch (proto) {
853	case IPPROTO_UDP:
854	link_type = LINK_UDP;
855	break;
856	case IPPROTO_TCP:
857	link_type = LINK_TCP;
858	break;
859	default:
860	return (0);
861	break;
862	}
863
864	/*
865	* The aliasing port is automatically selected by one of two
866	* methods below:
867	*/
868	max_trials = GET_NEW_PORT_MAX_ATTEMPTS;
869
870	if (la->packetAliasMode & PKT_ALIAS_SAME_PORTS) {
871	/*
872	* When the ALIAS_SAME_PORTS option is chosen, the first
873	* try will be the actual source port. If this is already
874	* in use, the remainder of the trials will be random.
875	*/
876	port_sys = ntohs(src_port);
877
878	} else {
879
880	/* First trial and all subsequent are random. */
881	if (align == FIND_EVEN_ALIAS_BASE)
882	port_sys = arc4random() & ALIAS_PORT_MASK_EVEN;
883	else
884	port_sys = arc4random() & ALIAS_PORT_MASK;
885
886	port_sys += ALIAS_PORT_BASE;
887	}
888
889	/* Port number search */
890	for (i = 0; i < max_trials; i++) {
891
892	struct alias_link *search_result;
893
894	for (j = 0; j < port_count; j++)
895	if (0 != (search_result = FindLinkIn(la, dst_addr, alias_addr,
896	dst_port, htons(port_sys + j),
897	link_type, 0)))
898	break;
899
900	/* Found a good range, return base */
901	if (j == port_count)
902	return (htons(port_sys));
903
904	/* Find a new base to try */
905	if (align == FIND_EVEN_ALIAS_BASE)
906	port_sys = arc4random() & ALIAS_PORT_MASK_EVEN;
907	else
908	port_sys = arc4random() & ALIAS_PORT_MASK;
909
910	port_sys += ALIAS_PORT_BASE;
911	}
912
913	#ifdef LIBALIAS_DEBUG
914	fprintf(stderr, "PacketAlias/FindNewPortGroup(): ");
915	fprintf(stderr, "could not find free port(s)\n");
916	#endif
917
918	return (0);
919	}
920
921	static void
922	CleanupAliasData(struct libalias *la)
923	{
924	struct alias_link *lnk;
925	int i;
926
927	LIBALIAS_LOCK_ASSERT(la);
928	for (i = 0; i < LINK_TABLE_OUT_SIZE; i++) {
929	lnk = LIST_FIRST(&la->linkTableOut[i]);
930	while (lnk != NULL) {
931	struct alias_link *link_next = LIST_NEXT(lnk, list_out);
932	DeleteLink(lnk);
933	lnk = link_next;
934	}
935	}
936
937	la->cleanupIndex = 0;
938	}
939
940
941	static void
942	IncrementalCleanup(struct libalias *la)
943	{
944	struct alias_link lnk, lnk_tmp;
945
946	LIBALIAS_LOCK_ASSERT(la);
947	LIST_FOREACH_SAFE(lnk, &la->linkTableOut[la->cleanupIndex++],
948	list_out, lnk_tmp) {
949	#ifndef VBOX
950	if (la->timeStamp - lnk->timestamp > lnk->expire_time)
951	#else
952	/* libalias counts time in seconds while slirp in millis */
953	if (la->timeStamp - lnk->timestamp > (1000 * lnk->expire_time))
954	#endif
955	DeleteLink(lnk);
956	}
957
958	if (la->cleanupIndex == LINK_TABLE_OUT_SIZE)
959	la->cleanupIndex = 0;
960	}
961
962	static void
963	DeleteLink(struct alias_link *lnk)
964	{
965	struct libalias *la = lnk->la;
966
967	LIBALIAS_LOCK_ASSERT(la);
968	/* Don't do anything if the link is marked permanent */
969	if (la->deleteAllLinks == 0 && lnk->flags & LINK_PERMANENT)
970	return;
971
972	#ifndef NO_FW_PUNCH
973	/* Delete associated firewall hole, if any */
974	ClearFWHole(lnk);
975	#endif
976
977	/* Free memory allocated for LSNAT server pool */
978	if (lnk->server != NULL) {
979	struct server head, curr, *next;
980
981	head = curr = lnk->server;
982	do {
983	next = curr->next;
984	free(curr);
985	} while ((curr = next) != head);
986	}
987	/* Adjust output table pointers */
988	LIST_REMOVE(lnk, list_out);
989
990	/* Adjust input table pointers */
991	LIST_REMOVE(lnk, list_in);
992	#ifndef NO_USE_SOCKETS
993	/* Close socket, if one has been allocated */
994	# ifndef VBOX
995	if (lnk->sockfd != -1) {
996	la->sockCount--;
997	close(lnk->sockfd);
998	}
999	# else
1000	/* Slirp will close the socket in its own way */
1001	# endif
1002	#endif
1003	/* Link-type dependent cleanup */
1004	switch (lnk->link_type) {
1005	case LINK_ICMP:
1006	la->icmpLinkCount--;
1007	break;
1008	case LINK_UDP:
1009	la->udpLinkCount--;
1010	break;
1011	case LINK_TCP:
1012	la->tcpLinkCount--;
1013	free(lnk->data.tcp);
1014	break;
1015	case LINK_PPTP:
1016	la->pptpLinkCount--;
1017	break;
1018	case LINK_FRAGMENT_ID:
1019	la->fragmentIdLinkCount--;
1020	break;
1021	case LINK_FRAGMENT_PTR:
1022	la->fragmentPtrLinkCount--;
1023	if (lnk->data.frag_ptr != NULL)
1024	free(lnk->data.frag_ptr);
1025	break;
1026	case LINK_ADDR:
1027	break;
1028	default:
1029	la->protoLinkCount--;
1030	break;
1031	}
1032
1033	/* Free memory */
1034	free(lnk);
1035
1036	/* Write statistics, if logging enabled */
1037	if (la->packetAliasMode & PKT_ALIAS_LOG) {
1038	ShowAliasStats(la);
1039	}
1040	}
1041
1042
1043	static struct alias_link *
1044	AddLink(struct libalias *la, struct in_addr src_addr,
1045	struct in_addr dst_addr,
1046	struct in_addr alias_addr,
1047	u_short src_port,
1048	u_short dst_port,
1049	int alias_port_param, /* if less than zero, alias */
1050	int link_type)
1051	{ /* port will be automatically // chosen.
1052	* If greater than */
1053	u_int start_point; /* zero, equal to alias port */
1054	struct alias_link *lnk;
1055
1056	LIBALIAS_LOCK_ASSERT(la);
1057	lnk = malloc(sizeof(struct alias_link));
1058	if (lnk != NULL) {
1059	/* Basic initialization */
1060	lnk->la = la;
1061	lnk->src_addr = src_addr;
1062	lnk->dst_addr = dst_addr;
1063	lnk->alias_addr = alias_addr;
1064	lnk->proxy_addr.s_addr = INADDR_ANY;
1065	lnk->src_port = src_port;
1066	lnk->dst_port = dst_port;
1067	lnk->proxy_port = 0;
1068	lnk->server = NULL;
1069	lnk->link_type = link_type;
1070	#ifndef NO_USE_SOCKETS
1071	# ifndef VBOX
1072	lnk->sockfd = -1;
1073	# endif
1074	#endif
1075	lnk->flags = 0;
1076	lnk->pflags = 0;
1077	lnk->timestamp = la->timeStamp;
1078
1079	/* Expiration time */
1080	switch (link_type) {
1081	case LINK_ICMP:
1082	lnk->expire_time = ICMP_EXPIRE_TIME;
1083	break;
1084	case LINK_UDP:
1085	lnk->expire_time = UDP_EXPIRE_TIME;
1086	break;
1087	case LINK_TCP:
1088	lnk->expire_time = TCP_EXPIRE_INITIAL;
1089	break;
1090	case LINK_PPTP:
1091	lnk->flags \|= LINK_PERMANENT; /* no timeout. */
1092	break;
1093	case LINK_FRAGMENT_ID:
1094	lnk->expire_time = FRAGMENT_ID_EXPIRE_TIME;
1095	break;
1096	case LINK_FRAGMENT_PTR:
1097	lnk->expire_time = FRAGMENT_PTR_EXPIRE_TIME;
1098	break;
1099	case LINK_ADDR:
1100	break;
1101	default:
1102	lnk->expire_time = PROTO_EXPIRE_TIME;
1103	break;
1104	}
1105
1106	/* Determine alias flags */
1107	if (dst_addr.s_addr == INADDR_ANY)
1108	lnk->flags \|= LINK_UNKNOWN_DEST_ADDR;
1109	if (dst_port == 0)
1110	lnk->flags \|= LINK_UNKNOWN_DEST_PORT;
1111
1112	/* Determine alias port */
1113	if (GetNewPort(la, lnk, alias_port_param) != 0) {
1114	free(lnk);
1115	return (NULL);
1116	}
1117	/* Link-type dependent initialization */
1118	switch (link_type) {
1119	struct tcp_dat *aux_tcp;
1120
1121	case LINK_ICMP:
1122	la->icmpLinkCount++;
1123	break;
1124	case LINK_UDP:
1125	la->udpLinkCount++;
1126	break;
1127	case LINK_TCP:
1128	aux_tcp = malloc(sizeof(struct tcp_dat));
1129	if (aux_tcp != NULL) {
1130	int i;
1131
1132	la->tcpLinkCount++;
1133	aux_tcp->state.in = ALIAS_TCP_STATE_NOT_CONNECTED;
1134	aux_tcp->state.out = ALIAS_TCP_STATE_NOT_CONNECTED;
1135	aux_tcp->state.index = 0;
1136	aux_tcp->state.ack_modified = 0;
1137	for (i = 0; i < N_LINK_TCP_DATA; i++)
1138	aux_tcp->ack[i].active = 0;
1139	aux_tcp->fwhole = -1;
1140	lnk->data.tcp = aux_tcp;
1141	} else {
1142	#ifdef LIBALIAS_DEBUG
1143	fprintf(stderr, "PacketAlias/AddLink: ");
1144	fprintf(stderr, " cannot allocate auxiliary TCP data\n");
1145	#endif
1146	free(lnk);
1147	return (NULL);
1148	}
1149	break;
1150	case LINK_PPTP:
1151	la->pptpLinkCount++;
1152	break;
1153	case LINK_FRAGMENT_ID:
1154	la->fragmentIdLinkCount++;
1155	break;
1156	case LINK_FRAGMENT_PTR:
1157	la->fragmentPtrLinkCount++;
1158	break;
1159	case LINK_ADDR:
1160	break;
1161	default:
1162	la->protoLinkCount++;
1163	break;
1164	}
1165
1166	/* Set up pointers for output lookup table */
1167	start_point = StartPointOut(src_addr, dst_addr,
1168	src_port, dst_port, link_type);
1169	LIST_INSERT_HEAD(&la->linkTableOut[start_point], lnk, list_out);
1170
1171	/* Set up pointers for input lookup table */
1172	start_point = StartPointIn(alias_addr, lnk->alias_port, link_type);
1173	LIST_INSERT_HEAD(&la->linkTableIn[start_point], lnk, list_in);
1174	} else {
1175	#ifdef LIBALIAS_DEBUG
1176	fprintf(stderr, "PacketAlias/AddLink(): ");
1177	fprintf(stderr, "malloc() call failed.\n");
1178	#endif
1179	}
1180	if (la->packetAliasMode & PKT_ALIAS_LOG) {
1181	ShowAliasStats(la);
1182	}
1183	return (lnk);
1184	}
1185
1186	static struct alias_link *
1187	ReLink(struct alias_link *old_lnk,
1188	struct in_addr src_addr,
1189	struct in_addr dst_addr,
1190	struct in_addr alias_addr,
1191	u_short src_port,
1192	u_short dst_port,
1193	int alias_port_param, /* if less than zero, alias */
1194	int link_type)
1195	{ /* port will be automatically // chosen.
1196	* If greater than */
1197	struct alias_link new_lnk; / zero, equal to alias port */
1198	struct libalias *la = old_lnk->la;
1199
1200	LIBALIAS_LOCK_ASSERT(la);
1201	new_lnk = AddLink(la, src_addr, dst_addr, alias_addr,
1202	src_port, dst_port, alias_port_param,
1203	link_type);
1204	#ifndef NO_FW_PUNCH
1205	if (new_lnk != NULL &&
1206	old_lnk->link_type == LINK_TCP &&
1207	old_lnk->data.tcp->fwhole > 0) {
1208	PunchFWHole(new_lnk);
1209	}
1210	#endif
1211	DeleteLink(old_lnk);
1212	return (new_lnk);
1213	}
1214
1215	static struct alias_link *
1216	_FindLinkOut(struct libalias *la, struct in_addr src_addr,
1217	struct in_addr dst_addr,
1218	u_short src_port,
1219	u_short dst_port,
1220	int link_type,
1221	int replace_partial_links)
1222	{
1223	u_int i;
1224	struct alias_link *lnk;
1225
1226	LIBALIAS_LOCK_ASSERT(la);
1227	i = StartPointOut(src_addr, dst_addr, src_port, dst_port, link_type);
1228	LIST_FOREACH(lnk, &la->linkTableOut[i], list_out) {
1229	if (lnk->dst_addr.s_addr == dst_addr.s_addr &&
1230	lnk->src_addr.s_addr == src_addr.s_addr &&
1231	lnk->src_port == src_port &&
1232	lnk->dst_port == dst_port &&
1233	lnk->link_type == link_type &&
1234	lnk->server == NULL) {
1235	lnk->timestamp = la->timeStamp;
1236	break;
1237	}
1238	}
1239
1240	/* Search for partially specified links. */
1241	if (lnk == NULL && replace_partial_links) {
1242	if (dst_port != 0 && dst_addr.s_addr != INADDR_ANY) {
1243	lnk = _FindLinkOut(la, src_addr, dst_addr, src_port, 0,
1244	link_type, 0);
1245	if (lnk == NULL)
1246	lnk = _FindLinkOut(la, src_addr, la->nullAddress, src_port,
1247	dst_port, link_type, 0);
1248	}
1249	if (lnk == NULL &&
1250	(dst_port != 0 \|\| dst_addr.s_addr != INADDR_ANY)) {
1251	lnk = _FindLinkOut(la, src_addr, la->nullAddress, src_port, 0,
1252	link_type, 0);
1253	}
1254	if (lnk != NULL) {
1255	lnk = ReLink(lnk,
1256	src_addr, dst_addr, lnk->alias_addr,
1257	src_port, dst_port, lnk->alias_port,
1258	link_type);
1259	}
1260	}
1261	return (lnk);
1262	}
1263
1264	static struct alias_link *
1265	FindLinkOut(struct libalias *la, struct in_addr src_addr,
1266	struct in_addr dst_addr,
1267	u_short src_port,
1268	u_short dst_port,
1269	int link_type,
1270	int replace_partial_links)
1271	{
1272	struct alias_link *lnk;
1273
1274	LIBALIAS_LOCK_ASSERT(la);
1275	lnk = _FindLinkOut(la, src_addr, dst_addr, src_port, dst_port,
1276	link_type, replace_partial_links);
1277
1278	if (lnk == NULL) {
1279	/*
1280	* The following allows permanent links to be specified as
1281	* using the default source address (i.e. device interface
1282	* address) without knowing in advance what that address
1283	* is.
1284	*/
1285	if (la->aliasAddress.s_addr != INADDR_ANY &&
1286	src_addr.s_addr == la->aliasAddress.s_addr) {
1287	lnk = _FindLinkOut(la, la->nullAddress, dst_addr, src_port, dst_port,
1288	link_type, replace_partial_links);
1289	}
1290	}
1291	return (lnk);
1292	}
1293
1294
1295	static struct alias_link *
1296	_FindLinkIn(struct libalias *la, struct in_addr dst_addr,
1297	struct in_addr alias_addr,
1298	u_short dst_port,
1299	u_short alias_port,
1300	int link_type,
1301	int replace_partial_links)
1302	{
1303	int flags_in;
1304	u_int start_point;
1305	struct alias_link *lnk;
1306	struct alias_link *lnk_fully_specified;
1307	struct alias_link *lnk_unknown_all;
1308	struct alias_link *lnk_unknown_dst_addr;
1309	struct alias_link *lnk_unknown_dst_port;
1310
1311	LIBALIAS_LOCK_ASSERT(la);
1312	/* Initialize pointers */
1313	lnk_fully_specified = NULL;
1314	lnk_unknown_all = NULL;
1315	lnk_unknown_dst_addr = NULL;
1316	lnk_unknown_dst_port = NULL;
1317
1318	/* If either the dest addr or port is unknown, the search
1319	loop will have to know about this. */
1320
1321	flags_in = 0;
1322	if (dst_addr.s_addr == INADDR_ANY)
1323	flags_in \|= LINK_UNKNOWN_DEST_ADDR;
1324	if (dst_port == 0)
1325	flags_in \|= LINK_UNKNOWN_DEST_PORT;
1326
1327	/* Search loop */
1328	start_point = StartPointIn(alias_addr, alias_port, link_type);
1329	LIST_FOREACH(lnk, &la->linkTableIn[start_point], list_in) {
1330	int flags;
1331
1332	flags = flags_in \| lnk->flags;
1333	if (!(flags & LINK_PARTIALLY_SPECIFIED)) {
1334	if (lnk->alias_addr.s_addr == alias_addr.s_addr
1335	&& lnk->alias_port == alias_port
1336	&& lnk->dst_addr.s_addr == dst_addr.s_addr
1337	&& lnk->dst_port == dst_port
1338	&& lnk->link_type == link_type) {
1339	lnk_fully_specified = lnk;
1340	break;
1341	}
1342	} else if ((flags & LINK_UNKNOWN_DEST_ADDR)
1343	&& (flags & LINK_UNKNOWN_DEST_PORT)) {
1344	if (lnk->alias_addr.s_addr == alias_addr.s_addr
1345	&& lnk->alias_port == alias_port
1346	&& lnk->link_type == link_type) {
1347	if (lnk_unknown_all == NULL)
1348	lnk_unknown_all = lnk;
1349	}
1350	} else if (flags & LINK_UNKNOWN_DEST_ADDR) {
1351	if (lnk->alias_addr.s_addr == alias_addr.s_addr
1352	&& lnk->alias_port == alias_port
1353	&& lnk->link_type == link_type
1354	&& lnk->dst_port == dst_port) {
1355	if (lnk_unknown_dst_addr == NULL)
1356	lnk_unknown_dst_addr = lnk;
1357	}
1358	} else if (flags & LINK_UNKNOWN_DEST_PORT) {
1359	if (lnk->alias_addr.s_addr == alias_addr.s_addr
1360	&& lnk->alias_port == alias_port
1361	&& lnk->link_type == link_type
1362	&& lnk->dst_addr.s_addr == dst_addr.s_addr) {
1363	if (lnk_unknown_dst_port == NULL)
1364	lnk_unknown_dst_port = lnk;
1365	}
1366	}
1367	}
1368
1369
1370
1371	if (lnk_fully_specified != NULL) {
1372	lnk_fully_specified->timestamp = la->timeStamp;
1373	lnk = lnk_fully_specified;
1374	} else if (lnk_unknown_dst_port != NULL)
1375	lnk = lnk_unknown_dst_port;
1376	else if (lnk_unknown_dst_addr != NULL)
1377	lnk = lnk_unknown_dst_addr;
1378	else if (lnk_unknown_all != NULL)
1379	lnk = lnk_unknown_all;
1380	else
1381	return (NULL);
1382
1383	if (replace_partial_links &&
1384	(lnk->flags & LINK_PARTIALLY_SPECIFIED \|\| lnk->server != NULL)) {
1385	struct in_addr src_addr;
1386	u_short src_port;
1387
1388	if (lnk->server != NULL) { /* LSNAT link */
1389	src_addr = lnk->server->addr;
1390	src_port = lnk->server->port;
1391	lnk->server = lnk->server->next;
1392	} else {
1393	src_addr = lnk->src_addr;
1394	src_port = lnk->src_port;
1395	}
1396
1397	lnk = ReLink(lnk,
1398	src_addr, dst_addr, alias_addr,
1399	src_port, dst_port, alias_port,
1400	link_type);
1401	}
1402	return (lnk);
1403	}
1404
1405	static struct alias_link *
1406	FindLinkIn(struct libalias *la, struct in_addr dst_addr,
1407	struct in_addr alias_addr,
1408	u_short dst_port,
1409	u_short alias_port,
1410	int link_type,
1411	int replace_partial_links)
1412	{
1413	struct alias_link *lnk;
1414
1415	LIBALIAS_LOCK_ASSERT(la);
1416	lnk = _FindLinkIn(la, dst_addr, alias_addr, dst_port, alias_port,
1417	link_type, replace_partial_links);
1418
1419	if (lnk == NULL) {
1420	/*
1421	* The following allows permanent links to be specified as
1422	* using the default aliasing address (i.e. device
1423	* interface address) without knowing in advance what that
1424	* address is.
1425	*/
1426	if (la->aliasAddress.s_addr != INADDR_ANY &&
1427	alias_addr.s_addr == la->aliasAddress.s_addr) {
1428	lnk = _FindLinkIn(la, dst_addr, la->nullAddress, dst_port, alias_port,
1429	link_type, replace_partial_links);
1430	}
1431	}
1432	return (lnk);
1433	}
1434
1435
1436
1437
1438	/* External routines for finding/adding links
1439
1440	-- "external" means outside alias_db.c, but within alias*.c --
1441
1442	FindIcmpIn(), FindIcmpOut()
1443	FindFragmentIn1(), FindFragmentIn2()
1444	AddFragmentPtrLink(), FindFragmentPtr()
1445	FindProtoIn(), FindProtoOut()
1446	FindUdpTcpIn(), FindUdpTcpOut()
1447	AddPptp(), FindPptpOutByCallId(), FindPptpInByCallId(),
1448	FindPptpOutByPeerCallId(), FindPptpInByPeerCallId()
1449	FindOriginalAddress(), FindAliasAddress()
1450
1451	(prototypes in alias_local.h)
1452	*/
1453
1454
1455	struct alias_link *
1456	FindIcmpIn(struct libalias *la, struct in_addr dst_addr,
1457	struct in_addr alias_addr,
1458	u_short id_alias,
1459	int create)
1460	{
1461	struct alias_link *lnk;
1462
1463	LIBALIAS_LOCK_ASSERT(la);
1464	lnk = FindLinkIn(la, dst_addr, alias_addr,
1465	NO_DEST_PORT, id_alias,
1466	LINK_ICMP, 0);
1467	if (lnk == NULL && create && !(la->packetAliasMode & PKT_ALIAS_DENY_INCOMING)) {
1468	struct in_addr target_addr;
1469
1470	target_addr = FindOriginalAddress(la, alias_addr);
1471	lnk = AddLink(la, target_addr, dst_addr, alias_addr,
1472	id_alias, NO_DEST_PORT, id_alias,
1473	LINK_ICMP);
1474	}
1475	return (lnk);
1476	}
1477
1478
1479	struct alias_link *
1480	FindIcmpOut(struct libalias *la, struct in_addr src_addr,
1481	struct in_addr dst_addr,
1482	u_short id,
1483	int create)
1484	{
1485	struct alias_link *lnk;
1486
1487	LIBALIAS_LOCK_ASSERT(la);
1488	lnk = FindLinkOut(la, src_addr, dst_addr,
1489	id, NO_DEST_PORT,
1490	LINK_ICMP, 0);
1491	if (lnk == NULL && create) {
1492	struct in_addr alias_addr;
1493
1494	alias_addr = FindAliasAddress(la, src_addr);
1495	lnk = AddLink(la, src_addr, dst_addr, alias_addr,
1496	id, NO_DEST_PORT, GET_ALIAS_ID,
1497	LINK_ICMP);
1498	}
1499	return (lnk);
1500	}
1501
1502
1503	struct alias_link *
1504	FindFragmentIn1(struct libalias *la, struct in_addr dst_addr,
1505	struct in_addr alias_addr,
1506	u_short ip_id)
1507	{
1508	struct alias_link *lnk;
1509
1510	LIBALIAS_LOCK_ASSERT(la);
1511	lnk = FindLinkIn(la, dst_addr, alias_addr,
1512	NO_DEST_PORT, ip_id,
1513	LINK_FRAGMENT_ID, 0);
1514
1515	if (lnk == NULL) {
1516	lnk = AddLink(la, la->nullAddress, dst_addr, alias_addr,
1517	NO_SRC_PORT, NO_DEST_PORT, ip_id,
1518	LINK_FRAGMENT_ID);
1519	}
1520	return (lnk);
1521	}
1522
1523
1524	struct alias_link *
1525	FindFragmentIn2(struct libalias la, struct in_addr dst_addr, / Doesn't add a link if
1526	* one */
1527	struct in_addr alias_addr, /* is not found. */
1528	u_short ip_id)
1529	{
1530
1531	LIBALIAS_LOCK_ASSERT(la);
1532	return FindLinkIn(la, dst_addr, alias_addr,
1533	NO_DEST_PORT, ip_id,
1534	LINK_FRAGMENT_ID, 0);
1535	}
1536
1537
1538	struct alias_link *
1539	AddFragmentPtrLink(struct libalias *la, struct in_addr dst_addr,
1540	u_short ip_id)
1541	{
1542
1543	LIBALIAS_LOCK_ASSERT(la);
1544	return AddLink(la, la->nullAddress, dst_addr, la->nullAddress,
1545	NO_SRC_PORT, NO_DEST_PORT, ip_id,
1546	LINK_FRAGMENT_PTR);
1547	}
1548
1549
1550	struct alias_link *
1551	FindFragmentPtr(struct libalias *la, struct in_addr dst_addr,
1552	u_short ip_id)
1553	{
1554
1555	LIBALIAS_LOCK_ASSERT(la);
1556	return FindLinkIn(la, dst_addr, la->nullAddress,
1557	NO_DEST_PORT, ip_id,
1558	LINK_FRAGMENT_PTR, 0);
1559	}
1560
1561
1562	struct alias_link *
1563	FindProtoIn(struct libalias *la, struct in_addr dst_addr,
1564	struct in_addr alias_addr,
1565	u_char proto)
1566	{
1567	struct alias_link *lnk;
1568
1569	LIBALIAS_LOCK_ASSERT(la);
1570	lnk = FindLinkIn(la, dst_addr, alias_addr,
1571	NO_DEST_PORT, 0,
1572	proto, 1);
1573
1574	if (lnk == NULL && !(la->packetAliasMode & PKT_ALIAS_DENY_INCOMING)) {
1575	struct in_addr target_addr;
1576
1577	target_addr = FindOriginalAddress(la, alias_addr);
1578	lnk = AddLink(la, target_addr, dst_addr, alias_addr,
1579	NO_SRC_PORT, NO_DEST_PORT, 0,
1580	proto);
1581	}
1582	return (lnk);
1583	}
1584
1585
1586	struct alias_link *
1587	FindProtoOut(struct libalias *la, struct in_addr src_addr,
1588	struct in_addr dst_addr,
1589	u_char proto)
1590	{
1591	struct alias_link *lnk;
1592
1593	LIBALIAS_LOCK_ASSERT(la);
1594	lnk = FindLinkOut(la, src_addr, dst_addr,
1595	NO_SRC_PORT, NO_DEST_PORT,
1596	proto, 1);
1597
1598	if (lnk == NULL) {
1599	struct in_addr alias_addr;
1600
1601	alias_addr = FindAliasAddress(la, src_addr);
1602	lnk = AddLink(la, src_addr, dst_addr, alias_addr,
1603	NO_SRC_PORT, NO_DEST_PORT, 0,
1604	proto);
1605	}
1606	return (lnk);
1607	}
1608
1609
1610	struct alias_link *
1611	FindUdpTcpIn(struct libalias *la, struct in_addr dst_addr,
1612	struct in_addr alias_addr,
1613	u_short dst_port,
1614	u_short alias_port,
1615	u_char proto,
1616	int create)
1617	{
1618	int link_type;
1619	struct alias_link *lnk;
1620
1621	LIBALIAS_LOCK_ASSERT(la);
1622	switch (proto) {
1623	case IPPROTO_UDP:
1624	link_type = LINK_UDP;
1625	break;
1626	case IPPROTO_TCP:
1627	link_type = LINK_TCP;
1628	break;
1629	default:
1630	return (NULL);
1631	break;
1632	}
1633
1634	lnk = FindLinkIn(la, dst_addr, alias_addr,
1635	dst_port, alias_port,
1636	link_type, create);
1637
1638	if (lnk == NULL && create && !(la->packetAliasMode & PKT_ALIAS_DENY_INCOMING)) {
1639	struct in_addr target_addr;
1640
1641	target_addr = FindOriginalAddress(la, alias_addr);
1642	lnk = AddLink(la, target_addr, dst_addr, alias_addr,
1643	alias_port, dst_port, alias_port,
1644	link_type);
1645	}
1646	return (lnk);
1647	}
1648
1649
1650	struct alias_link *
1651	FindUdpTcpOut(struct libalias *la, struct in_addr src_addr,
1652	struct in_addr dst_addr,
1653	u_short src_port,
1654	u_short dst_port,
1655	u_char proto,
1656	int create)
1657	{
1658	int link_type;
1659	struct alias_link *lnk;
1660
1661	LIBALIAS_LOCK_ASSERT(la);
1662	switch (proto) {
1663	case IPPROTO_UDP:
1664	link_type = LINK_UDP;
1665	break;
1666	case IPPROTO_TCP:
1667	link_type = LINK_TCP;
1668	break;
1669	default:
1670	return (NULL);
1671	break;
1672	}
1673
1674	lnk = FindLinkOut(la, src_addr, dst_addr, src_port, dst_port, link_type, create);
1675
1676	if (lnk == NULL && create) {
1677	struct in_addr alias_addr;
1678
1679	alias_addr = FindAliasAddress(la, src_addr);
1680	lnk = AddLink(la, src_addr, dst_addr, alias_addr,
1681	src_port, dst_port, GET_ALIAS_PORT,
1682	link_type);
1683	}
1684	return (lnk);
1685	}
1686
1687
1688	struct alias_link *
1689	AddPptp(struct libalias *la, struct in_addr src_addr,
1690	struct in_addr dst_addr,
1691	struct in_addr alias_addr,
1692	u_int16_t src_call_id)
1693	{
1694	struct alias_link *lnk;
1695
1696	LIBALIAS_LOCK_ASSERT(la);
1697	lnk = AddLink(la, src_addr, dst_addr, alias_addr,
1698	src_call_id, 0, GET_ALIAS_PORT,
1699	LINK_PPTP);
1700
1701	return (lnk);
1702	}
1703
1704
1705	struct alias_link *
1706	FindPptpOutByCallId(struct libalias *la, struct in_addr src_addr,
1707	struct in_addr dst_addr,
1708	u_int16_t src_call_id)
1709	{
1710	u_int i;
1711	struct alias_link *lnk;
1712
1713	LIBALIAS_LOCK_ASSERT(la);
1714	i = StartPointOut(src_addr, dst_addr, 0, 0, LINK_PPTP);
1715	LIST_FOREACH(lnk, &la->linkTableOut[i], list_out)
1716	if (lnk->link_type == LINK_PPTP &&
1717	lnk->src_addr.s_addr == src_addr.s_addr &&
1718	lnk->dst_addr.s_addr == dst_addr.s_addr &&
1719	lnk->src_port == src_call_id)
1720	break;
1721
1722	return (lnk);
1723	}
1724
1725
1726	struct alias_link *
1727	FindPptpOutByPeerCallId(struct libalias *la, struct in_addr src_addr,
1728	struct in_addr dst_addr,
1729	u_int16_t dst_call_id)
1730	{
1731	u_int i;
1732	struct alias_link *lnk;
1733
1734	LIBALIAS_LOCK_ASSERT(la);
1735	i = StartPointOut(src_addr, dst_addr, 0, 0, LINK_PPTP);
1736	LIST_FOREACH(lnk, &la->linkTableOut[i], list_out)
1737	if (lnk->link_type == LINK_PPTP &&
1738	lnk->src_addr.s_addr == src_addr.s_addr &&
1739	lnk->dst_addr.s_addr == dst_addr.s_addr &&
1740	lnk->dst_port == dst_call_id)
1741	break;
1742
1743	return (lnk);
1744	}
1745
1746
1747	struct alias_link *
1748	FindPptpInByCallId(struct libalias *la, struct in_addr dst_addr,
1749	struct in_addr alias_addr,
1750	u_int16_t dst_call_id)
1751	{
1752	u_int i;
1753	struct alias_link *lnk;
1754
1755	LIBALIAS_LOCK_ASSERT(la);
1756	i = StartPointIn(alias_addr, 0, LINK_PPTP);
1757	LIST_FOREACH(lnk, &la->linkTableIn[i], list_in)
1758	if (lnk->link_type == LINK_PPTP &&
1759	lnk->dst_addr.s_addr == dst_addr.s_addr &&
1760	lnk->alias_addr.s_addr == alias_addr.s_addr &&
1761	lnk->dst_port == dst_call_id)
1762	break;
1763
1764	return (lnk);
1765	}
1766
1767
1768	struct alias_link *
1769	FindPptpInByPeerCallId(struct libalias *la, struct in_addr dst_addr,
1770	struct in_addr alias_addr,
1771	u_int16_t alias_call_id)
1772	{
1773	struct alias_link *lnk;
1774
1775	LIBALIAS_LOCK_ASSERT(la);
1776	lnk = FindLinkIn(la, dst_addr, alias_addr,
1777	0 /* any */ , alias_call_id,
1778	LINK_PPTP, 0);
1779
1780
1781	return (lnk);
1782	}
1783
1784
1785	struct alias_link *
1786	FindRtspOut(struct libalias *la, struct in_addr src_addr,
1787	struct in_addr dst_addr,
1788	u_short src_port,
1789	u_short alias_port,
1790	u_char proto)
1791	{
1792	int link_type;
1793	struct alias_link *lnk;
1794
1795	LIBALIAS_LOCK_ASSERT(la);
1796	switch (proto) {
1797	case IPPROTO_UDP:
1798	link_type = LINK_UDP;
1799	break;
1800	case IPPROTO_TCP:
1801	link_type = LINK_TCP;
1802	break;
1803	default:
1804	return (NULL);
1805	break;
1806	}
1807
1808	lnk = FindLinkOut(la, src_addr, dst_addr, src_port, 0, link_type, 1);
1809
1810	if (lnk == NULL) {
1811	struct in_addr alias_addr;
1812
1813	alias_addr = FindAliasAddress(la, src_addr);
1814	lnk = AddLink(la, src_addr, dst_addr, alias_addr,
1815	src_port, 0, alias_port,
1816	link_type);
1817	}
1818	return (lnk);
1819	}
1820
1821
1822	struct in_addr
1823	FindOriginalAddress(struct libalias *la, struct in_addr alias_addr)
1824	{
1825	struct alias_link *lnk;
1826
1827	LIBALIAS_LOCK_ASSERT(la);
1828	lnk = FindLinkIn(la, la->nullAddress, alias_addr,
1829	0, 0, LINK_ADDR, 0);
1830	if (lnk == NULL) {
1831	la->newDefaultLink = 1;
1832	if (la->targetAddress.s_addr == INADDR_ANY)
1833	return (alias_addr);
1834	else if (la->targetAddress.s_addr == INADDR_NONE)
1835	return (la->aliasAddress.s_addr != INADDR_ANY) ?
1836	la->aliasAddress : alias_addr;
1837	else
1838	return (la->targetAddress);
1839	} else {
1840	if (lnk->server != NULL) { /* LSNAT link */
1841	struct in_addr src_addr;
1842
1843	src_addr = lnk->server->addr;
1844	lnk->server = lnk->server->next;
1845	return (src_addr);
1846	} else if (lnk->src_addr.s_addr == INADDR_ANY)
1847	return (la->aliasAddress.s_addr != INADDR_ANY) ?
1848	la->aliasAddress : alias_addr;
1849	else
1850	return (lnk->src_addr);
1851	}
1852	}
1853
1854
1855	struct in_addr
1856	FindAliasAddress(struct libalias *la, struct in_addr original_addr)
1857	{
1858	struct alias_link *lnk;
1859
1860	LIBALIAS_LOCK_ASSERT(la);
1861	lnk = FindLinkOut(la, original_addr, la->nullAddress,
1862	0, 0, LINK_ADDR, 0);
1863	if (lnk == NULL) {
1864	return (la->aliasAddress.s_addr != INADDR_ANY) ?
1865	la->aliasAddress : original_addr;
1866	} else {
1867	if (lnk->alias_addr.s_addr == INADDR_ANY)
1868	return (la->aliasAddress.s_addr != INADDR_ANY) ?
1869	la->aliasAddress : original_addr;
1870	else
1871	return (lnk->alias_addr);
1872	}
1873	}
1874
1875
1876	/* External routines for getting or changing link data
1877	(external to alias_db.c, but internal to alias*.c)
1878
1879	SetFragmentData(), GetFragmentData()
1880	SetFragmentPtr(), GetFragmentPtr()
1881	SetStateIn(), SetStateOut(), GetStateIn(), GetStateOut()
1882	GetOriginalAddress(), GetDestAddress(), GetAliasAddress()
1883	GetOriginalPort(), GetAliasPort()
1884	SetAckModified(), GetAckModified()
1885	GetDeltaAckIn(), GetDeltaSeqOut(), AddSeq()
1886	SetProtocolFlags(), GetProtocolFlags()
1887	SetDestCallId()
1888	*/
1889
1890
1891	void
1892	SetFragmentAddr(struct alias_link *lnk, struct in_addr src_addr)
1893	{
1894	lnk->data.frag_addr = src_addr;
1895	}
1896
1897
1898	void
1899	GetFragmentAddr(struct alias_link lnk, struct in_addr src_addr)
1900	{
1901	*src_addr = lnk->data.frag_addr;
1902	}
1903
1904
1905	void
1906	SetFragmentPtr(struct alias_link lnk, char fptr)
1907	{
1908	lnk->data.frag_ptr = fptr;
1909	}
1910
1911
1912	void
1913	GetFragmentPtr(struct alias_link lnk, char *fptr)
1914	{
1915	*fptr = lnk->data.frag_ptr;
1916	}
1917
1918
1919	void
1920	SetStateIn(struct alias_link *lnk, int state)
1921	{
1922	/* TCP input state */
1923	switch (state) {
1924	case ALIAS_TCP_STATE_DISCONNECTED:
1925	if (lnk->data.tcp->state.out != ALIAS_TCP_STATE_CONNECTED)
1926	lnk->expire_time = TCP_EXPIRE_DEAD;
1927	else
1928	lnk->expire_time = TCP_EXPIRE_SINGLEDEAD;
1929	break;
1930	case ALIAS_TCP_STATE_CONNECTED:
1931	if (lnk->data.tcp->state.out == ALIAS_TCP_STATE_CONNECTED)
1932	lnk->expire_time = TCP_EXPIRE_CONNECTED;
1933	break;
1934	default:
1935	#ifdef _KERNEL
1936	panic("libalias:SetStateIn() unknown state");
1937	#else
1938	abort();
1939	#endif
1940	}
1941	lnk->data.tcp->state.in = state;
1942	}
1943
1944
1945	void
1946	SetStateOut(struct alias_link *lnk, int state)
1947	{
1948	/* TCP output state */
1949	switch (state) {
1950	case ALIAS_TCP_STATE_DISCONNECTED:
1951	if (lnk->data.tcp->state.in != ALIAS_TCP_STATE_CONNECTED)
1952	lnk->expire_time = TCP_EXPIRE_DEAD;
1953	else
1954	lnk->expire_time = TCP_EXPIRE_SINGLEDEAD;
1955	break;
1956	case ALIAS_TCP_STATE_CONNECTED:
1957	if (lnk->data.tcp->state.in == ALIAS_TCP_STATE_CONNECTED)
1958	lnk->expire_time = TCP_EXPIRE_CONNECTED;
1959	break;
1960	default:
1961	#ifdef _KERNEL
1962	panic("libalias:SetStateOut() unknown state");
1963	#else
1964	abort();
1965	#endif
1966	}
1967	lnk->data.tcp->state.out = state;
1968	}
1969
1970
1971	int
1972	GetStateIn(struct alias_link *lnk)
1973	{
1974	/* TCP input state */
1975	return (lnk->data.tcp->state.in);
1976	}
1977
1978
1979	int
1980	GetStateOut(struct alias_link *lnk)
1981	{
1982	/* TCP output state */
1983	return (lnk->data.tcp->state.out);
1984	}
1985
1986
1987	struct in_addr
1988	GetOriginalAddress(struct alias_link *lnk)
1989	{
1990	if (lnk->src_addr.s_addr == INADDR_ANY)
1991	return (lnk->la->aliasAddress);
1992	else
1993	return (lnk->src_addr);
1994	}
1995
1996
1997	struct in_addr
1998	GetDestAddress(struct alias_link *lnk)
1999	{
2000	return (lnk->dst_addr);
2001	}
2002
2003
2004	struct in_addr
2005	GetAliasAddress(struct alias_link *lnk)
2006	{
2007	if (lnk->alias_addr.s_addr == INADDR_ANY)
2008	return (lnk->la->aliasAddress);
2009	else
2010	return (lnk->alias_addr);
2011	}
2012
2013
2014	struct in_addr
2015	GetDefaultAliasAddress(struct libalias *la)
2016	{
2017
2018	LIBALIAS_LOCK_ASSERT(la);
2019	return (la->aliasAddress);
2020	}
2021
2022
2023	void
2024	SetDefaultAliasAddress(struct libalias *la, struct in_addr alias_addr)
2025	{
2026
2027	LIBALIAS_LOCK_ASSERT(la);
2028	la->aliasAddress = alias_addr;
2029	}
2030
2031
2032	u_short
2033	GetOriginalPort(struct alias_link *lnk)
2034	{
2035	return (lnk->src_port);
2036	}
2037
2038
2039	u_short
2040	GetAliasPort(struct alias_link *lnk)
2041	{
2042	return (lnk->alias_port);
2043	}
2044
2045	#ifndef NO_FW_PUNCH
2046	static u_short
2047	GetDestPort(struct alias_link *lnk)
2048	{
2049	return (lnk->dst_port);
2050	}
2051
2052	#endif
2053
2054	void
2055	SetAckModified(struct alias_link *lnk)
2056	{
2057	/* Indicate that ACK numbers have been modified in a TCP connection */
2058	lnk->data.tcp->state.ack_modified = 1;
2059	}
2060
2061
2062	struct in_addr
2063	GetProxyAddress(struct alias_link *lnk)
2064	{
2065	return (lnk->proxy_addr);
2066	}
2067
2068
2069	void
2070	SetProxyAddress(struct alias_link *lnk, struct in_addr addr)
2071	{
2072	lnk->proxy_addr = addr;
2073	}
2074
2075
2076	u_short
2077	GetProxyPort(struct alias_link *lnk)
2078	{
2079	return (lnk->proxy_port);
2080	}
2081
2082
2083	void
2084	SetProxyPort(struct alias_link *lnk, u_short port)
2085	{
2086	lnk->proxy_port = port;
2087	}
2088
2089
2090	int
2091	GetAckModified(struct alias_link *lnk)
2092	{
2093	/* See if ACK numbers have been modified */
2094	return (lnk->data.tcp->state.ack_modified);
2095	}
2096
2097
2098	int
2099	GetDeltaAckIn(struct ip pip, struct alias_link lnk)
2100	{
2101	/*
2102	Find out how much the ACK number has been altered for an incoming
2103	TCP packet. To do this, a circular list of ACK numbers where the TCP
2104	packet size was altered is searched.
2105	*/
2106
2107	int i;
2108	struct tcphdr *tc;
2109	int delta, ack_diff_min;
2110	u_long ack;
2111
2112	tc = ip_next(pip);
2113	ack = tc->th_ack;
2114
2115	delta = 0;
2116	ack_diff_min = -1;
2117	for (i = 0; i < N_LINK_TCP_DATA; i++) {
2118	struct ack_data_record x;
2119
2120	x = lnk->data.tcp->ack[i];
2121	if (x.active == 1) {
2122	int ack_diff;
2123
2124	ack_diff = SeqDiff(x.ack_new, ack);
2125	if (ack_diff >= 0) {
2126	if (ack_diff_min >= 0) {
2127	if (ack_diff < ack_diff_min) {
2128	delta = x.delta;
2129	ack_diff_min = ack_diff;
2130	}
2131	} else {
2132	delta = x.delta;
2133	ack_diff_min = ack_diff;
2134	}
2135	}
2136	}
2137	}
2138	return (delta);
2139	}
2140
2141
2142	int
2143	GetDeltaSeqOut(struct ip pip, struct alias_link lnk)
2144	{
2145	/*
2146	Find out how much the sequence number has been altered for an outgoing
2147	TCP packet. To do this, a circular list of ACK numbers where the TCP
2148	packet size was altered is searched.
2149	*/
2150
2151	int i;
2152	struct tcphdr *tc;
2153	int delta, seq_diff_min;
2154	u_long seq;
2155
2156	tc = ip_next(pip);
2157	seq = tc->th_seq;
2158
2159	delta = 0;
2160	seq_diff_min = -1;
2161	for (i = 0; i < N_LINK_TCP_DATA; i++) {
2162	struct ack_data_record x;
2163
2164	x = lnk->data.tcp->ack[i];
2165	if (x.active == 1) {
2166	int seq_diff;
2167
2168	seq_diff = SeqDiff(x.ack_old, seq);
2169	if (seq_diff >= 0) {
2170	if (seq_diff_min >= 0) {
2171	if (seq_diff < seq_diff_min) {
2172	delta = x.delta;
2173	seq_diff_min = seq_diff;
2174	}
2175	} else {
2176	delta = x.delta;
2177	seq_diff_min = seq_diff;
2178	}
2179	}
2180	}
2181	}
2182	return (delta);
2183	}
2184
2185
2186	void
2187	AddSeq(struct ip pip, struct alias_link lnk, int delta)
2188	{
2189	/*
2190	When a TCP packet has been altered in length, save this
2191	information in a circular list. If enough packets have
2192	been altered, then this list will begin to overwrite itself.
2193	*/
2194
2195	struct tcphdr *tc;
2196	struct ack_data_record x;
2197	int hlen, tlen, dlen;
2198	int i;
2199
2200	tc = ip_next(pip);
2201
2202	hlen = (pip->ip_hl + tc->th_off) << 2;
2203	tlen = ntohs(pip->ip_len);
2204	dlen = tlen - hlen;
2205
2206	x.ack_old = htonl(ntohl(tc->th_seq) + dlen);
2207	x.ack_new = htonl(ntohl(tc->th_seq) + dlen + delta);
2208	x.delta = delta;
2209	x.active = 1;
2210
2211	i = lnk->data.tcp->state.index;
2212	lnk->data.tcp->ack[i] = x;
2213
2214	i++;
2215	if (i == N_LINK_TCP_DATA)
2216	lnk->data.tcp->state.index = 0;
2217	else
2218	lnk->data.tcp->state.index = i;
2219	}
2220
2221	void
2222	SetExpire(struct alias_link *lnk, int expire)
2223	{
2224	if (expire == 0) {
2225	lnk->flags &= ~LINK_PERMANENT;
2226	DeleteLink(lnk);
2227	} else if (expire == -1) {
2228	lnk->flags \|= LINK_PERMANENT;
2229	} else if (expire > 0) {
2230	lnk->expire_time = expire;
2231	} else {
2232	#ifdef LIBALIAS_DEBUG
2233	fprintf(stderr, "PacketAlias/SetExpire(): ");
2234	fprintf(stderr, "error in expire parameter\n");
2235	#endif
2236	}
2237	}
2238
2239	void
2240	ClearCheckNewLink(struct libalias *la)
2241	{
2242
2243	LIBALIAS_LOCK_ASSERT(la);
2244	la->newDefaultLink = 0;
2245	}
2246
2247	void
2248	SetProtocolFlags(struct alias_link *lnk, int pflags)
2249	{
2250
2251	lnk->pflags = pflags;;
2252	}
2253
2254	int
2255	GetProtocolFlags(struct alias_link *lnk)
2256	{
2257
2258	return (lnk->pflags);
2259	}
2260
2261	void
2262	SetDestCallId(struct alias_link *lnk, u_int16_t cid)
2263	{
2264	struct libalias *la = lnk->la;
2265
2266	LIBALIAS_LOCK_ASSERT(la);
2267	la->deleteAllLinks = 1;
2268	ReLink(lnk, lnk->src_addr, lnk->dst_addr, lnk->alias_addr,
2269	lnk->src_port, cid, lnk->alias_port, lnk->link_type);
2270	la->deleteAllLinks = 0;
2271	}
2272
2273
2274	/* Miscellaneous Functions
2275
2276	HouseKeeping()
2277	InitPacketAliasLog()
2278	UninitPacketAliasLog()
2279	*/
2280
2281	/*
2282	Whenever an outgoing or incoming packet is handled, HouseKeeping()
2283	is called to find and remove timed-out aliasing links. Logic exists
2284	to sweep through the entire table and linked list structure
2285	every 60 seconds.
2286
2287	(prototype in alias_local.h)
2288	*/
2289
2290	void
2291	HouseKeeping(struct libalias *la)
2292	{
2293	int i, n;
2294	#ifndef VBOX
2295	#ifndef _KERNEL
2296	struct timeval tv;
2297	struct timezone tz;
2298	#endif
2299
2300	LIBALIAS_LOCK_ASSERT(la);
2301	/*
2302	* Save system time (seconds) in global variable timeStamp for use
2303	* by other functions. This is done so as not to unnecessarily
2304	* waste timeline by making system calls.
2305	*/
2306	#ifdef _KERNEL
2307	la->timeStamp = time_uptime;
2308	#else
2309	gettimeofday(&tv, &tz);
2310	la->timeStamp = tv.tv_sec;
2311	#endif
2312	#else /* !VBOX */
2313	LIBALIAS_LOCK_ASSERT(la);
2314	la->timeStamp = la->curtime;
2315	#endif
2316
2317	/* Compute number of spokes (output table link chains) to cover */
2318	#ifndef VBOX
2319	n = LINK_TABLE_OUT_SIZE * (la->timeStamp - la->lastCleanupTime);
2320	#else
2321	n = LINK_TABLE_OUT_SIZE * ((la->timeStamp - la->lastCleanupTime)/1000);
2322	#endif
2323	n /= ALIAS_CLEANUP_INTERVAL_SECS;
2324
2325	/* Handle different cases */
2326	if (n > 0) {
2327	if (n > ALIAS_CLEANUP_MAX_SPOKES)
2328	n = ALIAS_CLEANUP_MAX_SPOKES;
2329	la->lastCleanupTime = la->timeStamp;
2330	for (i = 0; i < n; i++)
2331	IncrementalCleanup(la);
2332	} else if (n < 0) {
2333	#ifdef LIBALIAS_DEBUG
2334	fprintf(stderr, "PacketAlias/HouseKeeping(): ");
2335	fprintf(stderr, "something unexpected in time values\n");
2336	#endif
2337	la->lastCleanupTime = la->timeStamp;
2338	}
2339	}
2340
2341	/* Init the log file and enable logging */
2342	static int
2343	InitPacketAliasLog(struct libalias *la)
2344	{
2345
2346	LIBALIAS_LOCK_ASSERT(la);
2347	if (~la->packetAliasMode & PKT_ALIAS_LOG) {
2348	#ifndef VBOX
2349	#ifdef _KERNEL
2350	if ((la->logDesc = malloc(LIBALIAS_BUF_SIZE)))
2351	;
2352	#else
2353	if ((la->logDesc = fopen("/var/log/alias.log", "w")))
2354	fprintf(la->logDesc, "PacketAlias/InitPacketAliasLog: Packet alias logging enabled.\n");
2355	#endif
2356	else
2357	return (ENOMEM); /* log initialization failed */
2358	#else
2359	Log2(("NAT: PacketAlias/InitPacketAliasLog: Packet alias logging enabled.\n"));
2360	la->logDesc = (void )1; / XXX: in vbox we don't use this param */
2361	#endif
2362	la->packetAliasMode \|= PKT_ALIAS_LOG;
2363	}
2364
2365	return (1);
2366	}
2367
2368	/* Close the log-file and disable logging. */
2369	static void
2370	UninitPacketAliasLog(struct libalias *la)
2371	{
2372
2373	LIBALIAS_LOCK_ASSERT(la);
2374	if (la->logDesc) {
2375	#ifndef VBOX
2376	#ifdef _KERNEL
2377	free(la->logDesc);
2378	#else
2379	fclose(la->logDesc);
2380	#endif
2381	#endif /* !VBOX */
2382	la->logDesc = NULL;
2383	}
2384	la->packetAliasMode &= ~PKT_ALIAS_LOG;
2385	}
2386
2387	/* Outside world interfaces
2388
2389	-- "outside world" means other than alias*.c routines --
2390
2391	PacketAliasRedirectPort()
2392	PacketAliasAddServer()
2393	PacketAliasRedirectProto()
2394	PacketAliasRedirectAddr()
2395	PacketAliasRedirectDynamic()
2396	PacketAliasRedirectDelete()
2397	PacketAliasSetAddress()
2398	PacketAliasInit()
2399	PacketAliasUninit()
2400	PacketAliasSetMode()
2401
2402	(prototypes in alias.h)
2403	*/
2404
2405	/* Redirection from a specific public addr:port to a
2406	private addr:port */
2407	struct alias_link *
2408	LibAliasRedirectPort(struct libalias *la, struct in_addr src_addr, u_short src_port,
2409	struct in_addr dst_addr, u_short dst_port,
2410	struct in_addr alias_addr, u_short alias_port,
2411	u_char proto)
2412	{
2413	int link_type;
2414	struct alias_link *lnk;
2415
2416	LIBALIAS_LOCK(la);
2417	switch (proto) {
2418	case IPPROTO_UDP:
2419	link_type = LINK_UDP;
2420	break;
2421	case IPPROTO_TCP:
2422	link_type = LINK_TCP;
2423	break;
2424	default:
2425	#ifdef LIBALIAS_DEBUG
2426	fprintf(stderr, "PacketAliasRedirectPort(): ");
2427	fprintf(stderr, "only TCP and UDP protocols allowed\n");
2428	#endif
2429	lnk = NULL;
2430	goto getout;
2431	}
2432
2433	lnk = AddLink(la, src_addr, dst_addr, alias_addr,
2434	src_port, dst_port, alias_port,
2435	link_type);
2436
2437	if (lnk != NULL) {
2438	lnk->flags \|= LINK_PERMANENT;
2439	}
2440	#ifdef LIBALIAS_DEBUG
2441	else {
2442	fprintf(stderr, "PacketAliasRedirectPort(): "
2443	"call to AddLink() failed\n");
2444	}
2445	#endif
2446
2447	getout:
2448	LIBALIAS_UNLOCK(la);
2449	return (lnk);
2450	}
2451
2452	/* Add server to the pool of servers */
2453	int
2454	LibAliasAddServer(struct libalias la, struct alias_link lnk, struct in_addr addr, u_short port)
2455	{
2456	struct server *server;
2457	int res;
2458
2459	LIBALIAS_LOCK(la);
2460	(void)la;
2461
2462	server = malloc(sizeof(struct server));
2463
2464	if (server != NULL) {
2465	struct server *head;
2466
2467	server->addr = addr;
2468	server->port = port;
2469
2470	head = lnk->server;
2471	if (head == NULL)
2472	server->next = server;
2473	else {
2474	struct server *s;
2475
2476	for (s = head; s->next != head; s = s->next);
2477	s->next = server;
2478	server->next = head;
2479	}
2480	lnk->server = server;
2481	res = 0;
2482	} else
2483	res = -1;
2484
2485	LIBALIAS_UNLOCK(la);
2486	return (res);
2487	}
2488
2489	/* Redirect packets of a given IP protocol from a specific
2490	public address to a private address */
2491	struct alias_link *
2492	LibAliasRedirectProto(struct libalias *la, struct in_addr src_addr,
2493	struct in_addr dst_addr,
2494	struct in_addr alias_addr,
2495	u_char proto)
2496	{
2497	struct alias_link *lnk;
2498
2499	LIBALIAS_LOCK(la);
2500	lnk = AddLink(la, src_addr, dst_addr, alias_addr,
2501	NO_SRC_PORT, NO_DEST_PORT, 0,
2502	proto);
2503
2504	if (lnk != NULL) {
2505	lnk->flags \|= LINK_PERMANENT;
2506	}
2507	#ifdef LIBALIAS_DEBUG
2508	else {
2509	fprintf(stderr, "PacketAliasRedirectProto(): "
2510	"call to AddLink() failed\n");
2511	}
2512	#endif
2513
2514	LIBALIAS_UNLOCK(la);
2515	return (lnk);
2516	}
2517
2518	/* Static address translation */
2519	struct alias_link *
2520	LibAliasRedirectAddr(struct libalias *la, struct in_addr src_addr,
2521	struct in_addr alias_addr)
2522	{
2523	struct alias_link *lnk;
2524
2525	LIBALIAS_LOCK(la);
2526	lnk = AddLink(la, src_addr, la->nullAddress, alias_addr,
2527	0, 0, 0,
2528	LINK_ADDR);
2529
2530	if (lnk != NULL) {
2531	lnk->flags \|= LINK_PERMANENT;
2532	}
2533	#ifdef LIBALIAS_DEBUG
2534	else {
2535	fprintf(stderr, "PacketAliasRedirectAddr(): "
2536	"call to AddLink() failed\n");
2537	}
2538	#endif
2539
2540	LIBALIAS_UNLOCK(la);
2541	return (lnk);
2542	}
2543
2544
2545	/* Mark the aliasing link dynamic */
2546	int
2547	LibAliasRedirectDynamic(struct libalias la, struct alias_link lnk)
2548	{
2549	int res;
2550
2551	LIBALIAS_LOCK(la);
2552	(void)la;
2553
2554	if (lnk->flags & LINK_PARTIALLY_SPECIFIED)
2555	res = -1;
2556	else {
2557	lnk->flags &= ~LINK_PERMANENT;
2558	res = 0;
2559	}
2560	LIBALIAS_UNLOCK(la);
2561	return (res);
2562	}
2563
2564
2565	void
2566	LibAliasRedirectDelete(struct libalias la, struct alias_link lnk)
2567	{
2568	/* This is a dangerous function to put in the API,
2569	because an invalid pointer can crash the program. */
2570
2571	LIBALIAS_LOCK(la);
2572	la->deleteAllLinks = 1;
2573	DeleteLink(lnk);
2574	la->deleteAllLinks = 0;
2575	LIBALIAS_UNLOCK(la);
2576	}
2577
2578
2579	void
2580	LibAliasSetAddress(struct libalias *la, struct in_addr addr)
2581	{
2582
2583	LIBALIAS_LOCK(la);
2584	if (la->packetAliasMode & PKT_ALIAS_RESET_ON_ADDR_CHANGE
2585	&& la->aliasAddress.s_addr != addr.s_addr)
2586	CleanupAliasData(la);
2587
2588	la->aliasAddress = addr;
2589	LIBALIAS_UNLOCK(la);
2590	}
2591
2592
2593	void
2594	LibAliasSetTarget(struct libalias *la, struct in_addr target_addr)
2595	{
2596
2597	LIBALIAS_LOCK(la);
2598	la->targetAddress = target_addr;
2599	LIBALIAS_UNLOCK(la);
2600	}
2601
2602	#ifndef VBOX
2603	static void
2604	finishoff(void)
2605	{
2606
2607	while (!LIST_EMPTY(&instancehead))
2608	LibAliasUninit(LIST_FIRST(&instancehead));
2609	}
2610	#endif
2611
2612	struct libalias *
2613	#ifndef VBOX
2614	LibAliasInit(struct libalias *la)
2615	#else
2616	LibAliasInit(PNATState pData, struct libalias *la)
2617	#endif
2618	{
2619	int i;
2620	#ifndef VBOX
2621	#ifndef _KERNEL
2622	struct timeval tv;
2623	struct timezone tz;
2624	#endif
2625	#endif /* !VBOX */
2626
2627	if (la == NULL) {
2628	la = calloc(sizeof *la, 1);
2629	if (la == NULL)
2630	return (la);
2631
2632	#ifndef VBOX
2633	#ifndef _KERNEL /* kernel cleans up on module unload */
2634	if (LIST_EMPTY(&instancehead))
2635	atexit(finishoff);
2636	#endif
2637	#endif /!VBOX/
2638	LIST_INSERT_HEAD(&instancehead, la, instancelist);
2639
2640	#ifndef VBOX
2641	#ifdef _KERNEL
2642	la->timeStamp = time_uptime;
2643	la->lastCleanupTime = time_uptime;
2644	#else
2645	gettimeofday(&tv, &tz);
2646	la->timeStamp = tv.tv_sec;
2647	la->lastCleanupTime = tv.tv_sec;
2648	#endif
2649	#else /* !VBOX */
2650	la->pData = pData;
2651	la->timeStamp = curtime;
2652	la->lastCleanupTime = curtime;
2653	#endif /* VBOX */
2654
2655	for (i = 0; i < LINK_TABLE_OUT_SIZE; i++)
2656	LIST_INIT(&la->linkTableOut[i]);
2657	for (i = 0; i < LINK_TABLE_IN_SIZE; i++)
2658	LIST_INIT(&la->linkTableIn[i]);
2659	LIBALIAS_LOCK_INIT(la);
2660	LIBALIAS_LOCK(la);
2661	} else {
2662	LIBALIAS_LOCK(la);
2663	la->deleteAllLinks = 1;
2664	CleanupAliasData(la);
2665	la->deleteAllLinks = 0;
2666	}
2667
2668	la->aliasAddress.s_addr = INADDR_ANY;
2669	la->targetAddress.s_addr = INADDR_ANY;
2670
2671	la->icmpLinkCount = 0;
2672	la->udpLinkCount = 0;
2673	la->tcpLinkCount = 0;
2674	la->pptpLinkCount = 0;
2675	la->protoLinkCount = 0;
2676	la->fragmentIdLinkCount = 0;
2677	la->fragmentPtrLinkCount = 0;
2678	la->sockCount = 0;
2679
2680	la->cleanupIndex = 0;
2681
2682	la->packetAliasMode = PKT_ALIAS_SAME_PORTS
2683	#ifndef NO_USE_SOCKETS
2684	\| PKT_ALIAS_USE_SOCKETS
2685	#endif
2686	\| PKT_ALIAS_RESET_ON_ADDR_CHANGE;
2687	#ifndef NO_FW_PUNCH
2688	la->fireWallFD = -1;
2689	#endif
2690	#ifndef _KERNEL
2691	LibAliasRefreshModules();
2692	#endif
2693	LIBALIAS_UNLOCK(la);
2694	return (la);
2695	}
2696
2697	void
2698	LibAliasUninit(struct libalias *la)
2699	{
2700
2701	LIBALIAS_LOCK(la);
2702	la->deleteAllLinks = 1;
2703	CleanupAliasData(la);
2704	la->deleteAllLinks = 0;
2705	UninitPacketAliasLog(la);
2706	#ifndef NO_FW_PUNCH
2707	UninitPunchFW(la);
2708	#endif
2709	LIST_REMOVE(la, instancelist);
2710	LIBALIAS_UNLOCK(la);
2711	LIBALIAS_LOCK_DESTROY(la);
2712	free(la);
2713	}
2714
2715	/* Change mode for some operations */
2716	unsigned int
2717	LibAliasSetMode(
2718	struct libalias *la,
2719	unsigned int flags, /* Which state to bring flags to */
2720	unsigned int mask /* Mask of which flags to affect (use 0 to
2721	* do a probe for flag values) */
2722	)
2723	{
2724	int res = -1;
2725
2726	LIBALIAS_LOCK(la);
2727	/* Enable logging? */
2728	if (flags & mask & PKT_ALIAS_LOG) {
2729	/* Do the enable */
2730	if (InitPacketAliasLog(la) == ENOMEM)
2731	goto getout;
2732	} else
2733	/* _Disable_ logging? */
2734	if (~flags & mask & PKT_ALIAS_LOG) {
2735	UninitPacketAliasLog(la);
2736	}
2737	#ifndef NO_FW_PUNCH
2738	/* Start punching holes in the firewall? */
2739	if (flags & mask & PKT_ALIAS_PUNCH_FW) {
2740	InitPunchFW(la);
2741	} else
2742	/* Stop punching holes in the firewall? */
2743	if (~flags & mask & PKT_ALIAS_PUNCH_FW) {
2744	UninitPunchFW(la);
2745	}
2746	#endif
2747
2748	/* Other flags can be set/cleared without special action */
2749	la->packetAliasMode = (flags & mask) \| (la->packetAliasMode & ~mask);
2750	res = la->packetAliasMode;
2751	getout:
2752	LIBALIAS_UNLOCK(la);
2753	return (res);
2754	}
2755
2756
2757	int
2758	LibAliasCheckNewLink(struct libalias *la)
2759	{
2760	int res;
2761
2762	LIBALIAS_LOCK(la);
2763	res = la->newDefaultLink;
2764	LIBALIAS_UNLOCK(la);
2765	return (res);
2766	}
2767
2768
2769	#ifndef NO_FW_PUNCH
2770
2771	/*****************
2772	Code to support firewall punching. This shouldn't really be in this
2773	file, but making variables global is evil too.
2774	****************/
2775
2776	/* Firewall include files */
2777	#include <net/if.h>
2778	#include <netinet/ip_fw.h>
2779	#include <string.h>
2780	#include <err.h>
2781
2782	/*
2783	* helper function, updates the pointer to cmd with the length
2784	* of the current command, and also cleans up the first word of
2785	* the new command in case it has been clobbered before.
2786	*/
2787	static ipfw_insn *
2788	next_cmd(ipfw_insn * cmd)
2789	{
2790	cmd += F_LEN(cmd);
2791	bzero(cmd, sizeof(*cmd));
2792	return (cmd);
2793	}
2794
2795	/*
2796	* A function to fill simple commands of size 1.
2797	* Existing flags are preserved.
2798	*/
2799	static ipfw_insn *
2800	fill_cmd(ipfw_insn * cmd, enum ipfw_opcodes opcode, int size,
2801	int flags, u_int16_t arg)
2802	{
2803	cmd->opcode = opcode;
2804	cmd->len = ((cmd->len \| flags) & (F_NOT \| F_OR)) \| (size & F_LEN_MASK);
2805	cmd->arg1 = arg;
2806	return next_cmd(cmd);
2807	}
2808
2809	static ipfw_insn *
2810	fill_ip(ipfw_insn * cmd1, enum ipfw_opcodes opcode, u_int32_t addr)
2811	{
2812	ipfw_insn_ip cmd = (ipfw_insn_ip ) cmd1;
2813
2814	cmd->addr.s_addr = addr;
2815	return fill_cmd(cmd1, opcode, F_INSN_SIZE(ipfw_insn_u32), 0, 0);
2816	}
2817
2818	static ipfw_insn *
2819	fill_one_port(ipfw_insn * cmd1, enum ipfw_opcodes opcode, u_int16_t port)
2820	{
2821	ipfw_insn_u16 cmd = (ipfw_insn_u16 ) cmd1;
2822
2823	cmd->ports[0] = cmd->ports[1] = port;
2824	return fill_cmd(cmd1, opcode, F_INSN_SIZE(ipfw_insn_u16), 0, 0);
2825	}
2826
2827	static int
2828	fill_rule(void *buf, int bufsize, int rulenum,
2829	enum ipfw_opcodes action, int proto,
2830	struct in_addr sa, u_int16_t sp, struct in_addr da, u_int16_t dp)
2831	{
2832	struct ip_fw rule = (struct ip_fw )buf;
2833	ipfw_insn cmd = (ipfw_insn ) rule->cmd;
2834
2835	bzero(buf, bufsize);
2836	rule->rulenum = rulenum;
2837
2838	cmd = fill_cmd(cmd, O_PROTO, F_INSN_SIZE(ipfw_insn), 0, proto);
2839	cmd = fill_ip(cmd, O_IP_SRC, sa.s_addr);
2840	cmd = fill_one_port(cmd, O_IP_SRCPORT, sp);
2841	cmd = fill_ip(cmd, O_IP_DST, da.s_addr);
2842	cmd = fill_one_port(cmd, O_IP_DSTPORT, dp);
2843
2844	rule->act_ofs = (u_int32_t ) cmd - (u_int32_t ) rule->cmd;
2845	cmd = fill_cmd(cmd, action, F_INSN_SIZE(ipfw_insn), 0, 0);
2846
2847	rule->cmd_len = (u_int32_t ) cmd - (u_int32_t ) rule->cmd;
2848
2849	return ((char )cmd - (char )buf);
2850	}
2851
2852	static void ClearAllFWHoles(struct libalias *la);
2853
2854
2855	#define fw_setfield(la, field, num) \
2856	do { \
2857	(field)[(num) - la->fireWallBaseNum] = 1; \
2858	} /lint -save -e717 / while(0)/* lint -restore */
2859
2860	#define fw_clrfield(la, field, num) \
2861	do { \
2862	(field)[(num) - la->fireWallBaseNum] = 0; \
2863	} /lint -save -e717 / while(0)/* lint -restore */
2864
2865	#define fw_tstfield(la, field, num) ((field)[(num) - la->fireWallBaseNum])
2866
2867	static void
2868	InitPunchFW(struct libalias *la)
2869	{
2870
2871	LIBALIAS_LOCK_ASSERT(la);
2872	la->fireWallField = malloc(la->fireWallNumNums);
2873	if (la->fireWallField) {
2874	memset(la->fireWallField, 0, la->fireWallNumNums);
2875	if (la->fireWallFD < 0) {
2876	la->fireWallFD = socket(AF_INET, SOCK_RAW, IPPROTO_RAW);
2877	}
2878	ClearAllFWHoles(la);
2879	la->fireWallActiveNum = la->fireWallBaseNum;
2880	}
2881	}
2882
2883	static void
2884	UninitPunchFW(struct libalias *la)
2885	{
2886
2887	LIBALIAS_LOCK_ASSERT(la);
2888	ClearAllFWHoles(la);
2889	if (la->fireWallFD >= 0)
2890	#ifdef VBOX /* this code is currently dead but anyway ... */
2891	closesocket(la->fireWallFD);
2892	#else
2893	close(la->fireWallFD);
2894	#endif
2895	la->fireWallFD = -1;
2896	if (la->fireWallField)
2897	free(la->fireWallField);
2898	la->fireWallField = NULL;
2899	la->packetAliasMode &= ~PKT_ALIAS_PUNCH_FW;
2900	}
2901
2902	/* Make a certain link go through the firewall */
2903	void
2904	PunchFWHole(struct alias_link *lnk)
2905	{
2906	struct libalias *la;
2907	int r; /* Result code */
2908	struct ip_fw rule; /* On-the-fly built rule */
2909	int fwhole; /* Where to punch hole */
2910
2911	LIBALIAS_LOCK_ASSERT(la);
2912	la = lnk->la;
2913
2914	/* Don't do anything unless we are asked to */
2915	if (!(la->packetAliasMode & PKT_ALIAS_PUNCH_FW) \|\|
2916	la->fireWallFD < 0 \|\|
2917	lnk->link_type != LINK_TCP)
2918	return;
2919
2920	memset(&rule, 0, sizeof rule);
2921
2922	/ Build rule /
2923
2924	/* Find empty slot */
2925	for (fwhole = la->fireWallActiveNum;
2926	fwhole < la->fireWallBaseNum + la->fireWallNumNums &&
2927	fw_tstfield(la, la->fireWallField, fwhole);
2928	fwhole++);
2929	if (fwhole == la->fireWallBaseNum + la->fireWallNumNums) {
2930	for (fwhole = la->fireWallBaseNum;
2931	fwhole < la->fireWallActiveNum &&
2932	fw_tstfield(la, la->fireWallField, fwhole);
2933	fwhole++);
2934	if (fwhole == la->fireWallActiveNum) {
2935	/* No rule point empty - we can't punch more holes. */
2936	la->fireWallActiveNum = la->fireWallBaseNum;
2937	#ifdef LIBALIAS_DEBUG
2938	fprintf(stderr, "libalias: Unable to create firewall hole!\n");
2939	#endif
2940	return;
2941	}
2942	}
2943	/* Start next search at next position */
2944	la->fireWallActiveNum = fwhole + 1;
2945
2946	/*
2947	* generate two rules of the form
2948	*
2949	* add fwhole accept tcp from OAddr OPort to DAddr DPort add fwhole
2950	* accept tcp from DAddr DPort to OAddr OPort
2951	*/
2952	if (GetOriginalPort(lnk) != 0 && GetDestPort(lnk) != 0) {
2953	u_int32_t rulebuf[255];
2954	int i;
2955
2956	i = fill_rule(rulebuf, sizeof(rulebuf), fwhole,
2957	O_ACCEPT, IPPROTO_TCP,
2958	GetOriginalAddress(lnk), ntohs(GetOriginalPort(lnk)),
2959	GetDestAddress(lnk), ntohs(GetDestPort(lnk)));
2960	r = setsockopt(la->fireWallFD, IPPROTO_IP, IP_FW_ADD, rulebuf, i);
2961	if (r)
2962	err(1, "alias punch inbound(1) setsockopt(IP_FW_ADD)");
2963
2964	i = fill_rule(rulebuf, sizeof(rulebuf), fwhole,
2965	O_ACCEPT, IPPROTO_TCP,
2966	GetDestAddress(lnk), ntohs(GetDestPort(lnk)),
2967	GetOriginalAddress(lnk), ntohs(GetOriginalPort(lnk)));
2968	r = setsockopt(la->fireWallFD, IPPROTO_IP, IP_FW_ADD, rulebuf, i);
2969	if (r)
2970	err(1, "alias punch inbound(2) setsockopt(IP_FW_ADD)");
2971	}
2972
2973	/* Indicate hole applied */
2974	lnk->data.tcp->fwhole = fwhole;
2975	fw_setfield(la, la->fireWallField, fwhole);
2976	}
2977
2978	/* Remove a hole in a firewall associated with a particular alias
2979	lnk. Calling this too often is harmless. */
2980	static void
2981	ClearFWHole(struct alias_link *lnk)
2982	{
2983	struct libalias *la;
2984
2985	LIBALIAS_LOCK_ASSERT(la);
2986	la = lnk->la;
2987	if (lnk->link_type == LINK_TCP) {
2988	int fwhole = lnk->data.tcp->fwhole; /* Where is the firewall
2989	* hole? */
2990	struct ip_fw rule;
2991
2992	if (fwhole < 0)
2993	return;
2994
2995	memset(&rule, 0, sizeof rule); /* useless for ipfw2 */
2996	while (!setsockopt(la->fireWallFD, IPPROTO_IP, IP_FW_DEL,
2997	&fwhole, sizeof fwhole));
2998	fw_clrfield(la, la->fireWallField, fwhole);
2999	lnk->data.tcp->fwhole = -1;
3000	}
3001	}
3002
3003	/* Clear out the entire range dedicated to firewall holes. */
3004	static void
3005	ClearAllFWHoles(struct libalias *la)
3006	{
3007	struct ip_fw rule; /* On-the-fly built rule */
3008	int i;
3009
3010	LIBALIAS_LOCK_ASSERT(la);
3011	if (la->fireWallFD < 0)
3012	return;
3013
3014	memset(&rule, 0, sizeof rule);
3015	for (i = la->fireWallBaseNum; i < la->fireWallBaseNum + la->fireWallNumNums; i++) {
3016	int r = i;
3017
3018	while (!setsockopt(la->fireWallFD, IPPROTO_IP, IP_FW_DEL, &r, sizeof r));
3019	}
3020	/* XXX: third arg correct here ? /phk */
3021	memset(la->fireWallField, 0, la->fireWallNumNums);
3022	}
3023
3024	#endif
3025
3026	void
3027	LibAliasSetFWBase(struct libalias *la, unsigned int base, unsigned int num)
3028	{
3029
3030	LIBALIAS_LOCK(la);
3031	#ifndef NO_FW_PUNCH
3032	la->fireWallBaseNum = base;
3033	la->fireWallNumNums = num;
3034	#endif
3035	LIBALIAS_UNLOCK(la);
3036	}
3037
3038	void
3039	LibAliasSetSkinnyPort(struct libalias *la, unsigned int port)
3040	{
3041
3042	LIBALIAS_LOCK(la);
3043	la->skinnyPort = port;
3044	LIBALIAS_UNLOCK(la);
3045	}

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source: vbox/trunk/src/VBox/Devices/Network/slirp/libalias/alias_db.c@ 28023

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