[ViewVC] Diff of: cvs/gvpe/src/vpn

Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.4 by pcg, Wed Mar 2 05:49:31 2005 UTC vs.
Revision 1.7 by pcg, Thu Mar 3 16:54:34 2005 UTC

…		…
1	/*	1	/*
2	vpn_dns.C -- handle the dns tunnel part of the protocol.	2	vpn_dns.C -- handle the dns tunnel part of the protocol.
3	Copyright (C) 2003-2004 Marc Lehmann <pcg@goof.com>	3	Copyright (C) 2003-2005 Marc Lehmann <gvpe@schmorp.de>
4		4
		5	This file is part of GVPE.
		6
5	This program is free software; you can redistribute it and/or modify	7	GVPE is free software; you can redistribute it and/or modify
6	it under the terms of the GNU General Public License as published by	8	it under the terms of the GNU General Public License as published by
7	the Free Software Foundation; either version 2 of the License, or	9	the Free Software Foundation; either version 2 of the License, or
8	(at your option) any later version.	10	(at your option) any later version.
9		11
10	This program is distributed in the hope that it will be useful,	12	This program is distributed in the hope that it will be useful,
11	but WITHOUT ANY WARRANTY; without even the implied warranty of	13	but WITHOUT ANY WARRANTY; without even the implied warranty of
12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the	14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13	GNU General Public License for more details.	15	GNU General Public License for more details.
14		16
15	You should have received a copy of the GNU General Public License	17	You should have received a copy of the GNU General Public License
16	along with this program; if not, write to the Free Software	18	along with gvpe; if not, write to the Free Software
17	Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA	19	Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18	*/	20	*/
19		21
20	#include "config.h"	22	#include "config.h"
21		23
42	#include "vpn.h"	44	#include "vpn.h"
43		45
44	#define MIN_RETRY 1.	46	#define MIN_RETRY 1.
45	#define MAX_RETRY 60.	47	#define MAX_RETRY 60.
46		48
47	#define MAX_OUTSTANDING 10 // max. outstanding requests	49	#define MAX_OUTSTANDING 40 // max. outstanding requests
48	#define MAX_WINDOW 100 // max. for MAX_OUTSTANDING	50	#define MAX_WINDOW 100 // max. for MAX_OUTSTANDING
49	#define MAX_RATE 1 // requests/s	51	#define MAX_RATE 1000 // requests/s
50	#define MAX_BACKLOG (10*1024) // size of protocol backlog	52	#define MAX_BACKLOG (10*1024) // size of protocol backlog, must be > MAXSIZE
		53
		54	#define MAX_DOMAIN_SIZE 220 // 255 is legal limit, but bind doesn't compress well
		55	// 240 leaves about 4 bytes of server reply data
		56	// every two request byte sless give room for one reply byte
		57
		58	// seqno has 12 bits, but the lower bit is always left as zero
		59	// as bind caches ttl=0 records and we have to generate
		60	// sequence numbers that always differ case-insensitively
		61	#define SEQNO_MASK 0x07ff
51		62
52	/*	63	/*
53		64
54	protocol, in shorthand :)	65	protocol, in shorthand :)
55		66
…		…
84	static int decode (u8 dst, char src, int len);	95	static int decode (u8 dst, char src, int len);
85		96
86	dns64 ();	97	dns64 ();
87	} dns64;	98	} dns64;
88		99
89	const char dns64::encode_chars[64 + 1] = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_-";	100	// the following sequence has been crafted to
		101	// a) look somewhat random
		102	// b) the even (and odd) indices never share the same character as upper/lowercase
		103	const char dns64::encode_chars[64 + 1] = "_-dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI";
90	s8 dns64::decode_chars[256];	104	s8 dns64::decode_chars[256];
91		105
92	dns64::dns64 ()	106	dns64::dns64 ()
93	{	107	{
94	for (int i = 0; i < 64; i++)	108	for (int i = 0; i < 64; i++)
…		…
129	while (len--)	143	while (len--)
130	{	144	{
131	s8 chr = decode_chars [(u8)*src++];	145	s8 chr = decode_chars [(u8)*src++];
132		146
133	if (!chr)	147	if (!chr)
134	break;	148	continue;
135		149
136	accum <<= 6;	150	accum <<= 6;
137	accum \|= chr - 1;	151	accum \|= chr - 1;
138	bits += 6;	152	bits += 6;
139		153
…		…
159	~byte_stream ();	173	~byte_stream ();
160		174
161	bool empty () { return !fill; }	175	bool empty () { return !fill; }
162	int size () { return fill; }	176	int size () { return fill; }
163		177
		178	bool put (u8 *data, unsigned int datalen);
164	bool put (vpn_packet *pkt);	179	bool put (vpn_packet *pkt);
165	vpn_packet *get ();	180	vpn_packet *get ();
166		181
167	u8 *begin () { return data; }	182	u8 *begin () { return data; }
168	void remove (int count);	183	void remove (int count);
…		…
185	abort ();	200	abort ();
186		201
187	memmove (data, data + count, fill -= count);	202	memmove (data, data + count, fill -= count);
188	}	203	}
189		204
		205	bool byte_stream::put (u8 *data, unsigned int datalen)
		206	{
		207	if (maxsize - fill < datalen)
		208	return false;
		209
		210	memcpy (this->data + fill, data, datalen); fill += datalen;
		211
		212	return true;
		213	}
		214
190	bool byte_stream::put (vpn_packet *pkt)	215	bool byte_stream::put (vpn_packet *pkt)
191	{	216	{
192	if (maxsize - fill < pkt->len + 2)	217	if (maxsize - fill < pkt->len + 2)
193	return false;	218	return false;
194		219
…		…
202		227
203	vpn_packet *byte_stream::get ()	228	vpn_packet *byte_stream::get ()
204	{	229	{
205	int len = (data [0] << 8) \| data [1];	230	int len = (data [0] << 8) \| data [1];
206		231
		232	if (len > MAXSIZE && fill >= 2)
		233	abort (); // TODO handle this gracefully, connection reset
		234
207	if (fill < len + 2)	235	if (fill < len + 2)
208	return 0;	236	return 0;
209		237
210	vpn_packet *pkt = new vpn_packet;	238	vpn_packet *pkt = new vpn_packet;
		239
		240	pkt->len = len;
211	memcpy (&((*pkt)[0]), data + 2, len);	241	memcpy (&((*pkt)[0]), data + 2, len);
212	remove (len + 2);	242	remove (len + 2);
213		243
214	return pkt;	244	return pkt;
215	}	245	}
…		…
222	#define FLAG_OP_QUERY ( 0 << 11)	252	#define FLAG_OP_QUERY ( 0 << 11)
223	#define FLAG_AA ( 1 << 10)	253	#define FLAG_AA ( 1 << 10)
224	#define FLAG_TC ( 1 << 9)	254	#define FLAG_TC ( 1 << 9)
225	#define FLAG_RD ( 1 << 8)	255	#define FLAG_RD ( 1 << 8)
226	#define FLAG_RA ( 1 << 7)	256	#define FLAG_RA ( 1 << 7)
		257	#define FLAG_AUTH ( 1 << 5)
227	#define FLAG_RCODE_MASK (15 << 0)	258	#define FLAG_RCODE_MASK (15 << 0)
228	#define FLAG_RCODE_OK ( 0 << 0)	259	#define FLAG_RCODE_OK ( 0 << 0)
229	#define FLAG_RCODE_FORMERR ( 1 << 0)	260	#define FLAG_RCODE_FORMERR ( 1 << 0)
230	#define FLAG_RCODE_SERVFAIL ( 2 << 0)	261	#define FLAG_RCODE_SERVFAIL ( 2 << 0)
231	#define FLAG_RCODE_NXDOMAIN ( 3 << 0)	262	#define FLAG_RCODE_NXDOMAIN ( 3 << 0)
232	#define FLAG_RCODE_REFUSED ( 5 << 0)	263	#define FLAG_RCODE_REFUSED ( 5 << 0)
233		264
234	#define DEFAULT_CLIENT_FLAGS (FLAG_QUERY \| FLAG_OP_QUERY \| FLAG_RD)	265	#define DEFAULT_CLIENT_FLAGS (FLAG_QUERY \| FLAG_OP_QUERY \| FLAG_RD)
235	#define DEFAULT_SERVER_FLAGS (FLAG_RESPONSE \| FLAG_OP_QUERY \| FLAG_AA \| FLAG_RD)	266	#define DEFAULT_SERVER_FLAGS (FLAG_RESPONSE \| FLAG_OP_QUERY \| FLAG_AA \| FLAG_RD \| FLAG_RA)
236		267
237	struct dns_packet : net_packet	268	struct dns_packet : net_packet
238	{	269	{
239	u16 id;	270	u16 id;
240	u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4	271	u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4
…		…
285	{	316	{
286	dns_packet *pkt;	317	dns_packet *pkt;
287	tstamp next;	318	tstamp next;
288	int retry;	319	int retry;
289	connection *conn;	320	connection *conn;
		321	int seqno;
290		322
		323	dns_req (connection *c);
291	dns_req (connection c, int seqno, byte_stream stream);	324	void gen_stream_req (int seqno, byte_stream *stream);
292	};	325	};
293		326
294	struct dns_rep
295	{
296	};
297
298	static u16 dns_id; // TODO: should be per-vpn	327	static u16 dns_id = 12098; // TODO: should be per-vpn
299		328
300	dns_req::dns_req (connection c, int seqno, byte_stream stream)	329	static u16 next_id ()
		330	{
		331	// the simplest lsfr with periodicity 65535 i could find
		332	dns_id = (dns_id << 1)
		333	\| (((dns_id >> 1)
		334	^ (dns_id >> 2)
		335	^ (dns_id >> 4)
		336	^ (dns_id >> 15)) & 1);
		337
		338	return dns_id;
		339	}
		340
		341	dns_req::dns_req (connection *c)
301	: conn (c)	342	: conn (c)
302	{	343	{
303	next = 0;	344	next = 0;
304	retry = 0;	345	retry = 0;
305		346
306	pkt = new dns_packet;	347	pkt = new dns_packet;
307		348
308	pkt->id = dns_id++;	349	pkt->id = next_id ();
		350	}
		351
		352	void dns_req::gen_stream_req (int seqno, byte_stream *stream)
		353	{
		354	this->seqno = seqno;
		355
309	pkt->flags = DEFAULT_CLIENT_FLAGS;	356	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
310	pkt->qdcount = htons (1);	357	pkt->qdcount = htons (1);
311	pkt->ancount = 0;
312	pkt->nscount = 0;
313	pkt->arcount = 0;
314		358
315	int offs = 6*2;	359	int offs = 6*2;
316	int dlen = 255 - strlen (THISNODE->domain) - 1; // here we always have room for the max. label length	360	int dlen = MAX_DOMAIN_SIZE - strlen (THISNODE->domain) - 2;
		361	// MAX_DOMAIN_SIZE is technically 255, but bind doesn't compress responses well,
		362	// so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra
317		363
318	u8 lbl[64]; //D	364	u8 data[256]; //TODO
319	char enc[65];	365
320	int lbllen = 3;	366	data[0] = THISNODE->id; //TODO
321	lbl[0] = c->conf->id; //D
322	lbl[1] = seqno >> 8; //D	367	data[1] = seqno >> 7; //TODO
323	lbl[2] = seqno; //D	368	data[2] = seqno << 1; //TODO
324		369
325	while (dlen > 0)	370	int datalen = dns64::decode_len (dlen - (dlen + MAX_LBL_SIZE - 1) / MAX_LBL_SIZE) - 3;
326	{
327	int sndlen = dlen;
328		371
329	if (sndlen + lbllen > dns64::decode_len (MAX_LBL_SIZE))
330	sndlen = dns64::decode_len (MAX_LBL_SIZE) - lbllen;
331
332	if (sndlen > stream->size ())	372	if (datalen > stream->size ())
333	sndlen = stream->size ();	373	datalen = stream->size ();
334		374
335	if (sndlen + lbllen == 0)	375	char enc[256], *encp = enc;
336	break;	376
337
338	memcpy (lbl + lbllen, stream->begin (), sndlen);	377	memcpy (data + 3, stream->begin (), datalen);
		378	int enclen = dns64::encode (enc, data, datalen + 3);
339	stream->remove (sndlen);	379	stream->remove (datalen);
340	lbllen += sndlen;
341		380
342	dns64::encode (enc, lbl, lbllen);	381	while (enclen)
		382	{
		383	int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE;
343		384
344	int elen = dns64::encode_len (lbllen);
345	(*pkt)[offs++] = elen;	385	(*pkt)[offs++] = lbllen;
346	memcpy (&((*pkt)[offs]), enc, elen);	386	memcpy (pkt->at (offs), encp, lbllen);
		387
347	offs += elen;	388	offs += lbllen;
348	dlen -= elen + 1;	389	encp += lbllen;
349		390
350	lbllen = 0;	391	enclen -= lbllen;
351	}	392	}
352		393
353	const char *suffix = THISNODE->domain;	394	const char *suffix = THISNODE->domain;
354		395
355	// add tunnel domain	396	// add tunnel domain
…		…
375	(*pkt)[offs++] = 0;	416	(*pkt)[offs++] = 0;
376	(pkt)[offs++] = RR_TYPE_ANY >> 8; (pkt)[offs++] = RR_TYPE_ANY;	417	(pkt)[offs++] = RR_TYPE_ANY >> 8; (pkt)[offs++] = RR_TYPE_ANY;
377	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;	418	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;
378		419
379	pkt->len = offs;	420	pkt->len = offs;
		421	}
380		422
381	c->vpn->dns_sndpq.push_back (this);	423	struct dns_rcv
		424	{
		425	int seqno;
		426	dns_packet *pkt; // reply packet
		427	u8 data [MAXSIZE]; // actually part of the reply packet...
		428	int datalen;
		429
		430	dns_rcv (int seqno, u8 *data, int datalen);
		431	~dns_rcv ();
		432	};
		433
		434	dns_rcv::dns_rcv (int seqno, u8 *data, int datalen)
		435	: seqno (seqno), pkt (new dns_packet), datalen (datalen)
		436	{
		437	memcpy (this->data, data, datalen);
		438	}
		439
		440	dns_rcv::~dns_rcv ()
		441	{
		442	delete pkt;
382	}	443	}
383		444
384	/////////////////////////////////////////////////////////////////////////////	445	/////////////////////////////////////////////////////////////////////////////
385		446
386	struct dns_cfg	447	struct dns_cfg
…		…
390	u8 unused1;	451	u8 unused1;
391	u16 max_size;	452	u16 max_size;
392	u8 flags1, flags2;	453	u8 flags1, flags2;
393	};	454	};
394		455
		456	void connection::dnsv4_receive_rep (struct dns_rcv *r)
		457	{
		458	dns_rcvpq.push_back (r);
		459
		460	redo:
		461
		462	for (vector<dns_rcv *>::iterator i = dns_rcvpq.begin ();
		463	i != dns_rcvpq.end ();
		464	++i)
		465	if (dns_rcvseq == (*i)->seqno)
		466	{
		467	dns_rcv r = i;
		468
		469	dns_rcvseq = (dns_rcvseq + 1) & SEQNO_MASK;
		470
		471	if (!dns_snddq && !dns_rcvdq)
		472	{
		473	dns_rcvdq = new byte_stream (MAX_BACKLOG * 2);
		474	dns_snddq = new byte_stream (MAX_BACKLOG);
		475
		476	dns_si.set (::conf.dns_forw_host, ::conf.dns_forw_port, PROT_DNSv4);
		477	}
		478
		479	if (!dns_rcvdq->put (r->data, r->datalen))
		480	abort (); // MUST never overflow, can be caused by data corruption, TODO
		481
		482	while (vpn_packet *pkt = dns_rcvdq->get ())
		483	{
		484	sockinfo si;
		485	si.host = 0; si.port = 0; si.prot = PROT_DNSv4;
		486
		487	vpn->recv_vpn_packet (pkt, si);
		488	}
		489	}
		490	else if ((u32)(i)->seqno - (u32)dns_rcvseq + MAX_WINDOW > MAX_WINDOW 2)
		491	{
		492	//D
		493	//abort();
		494	printf ("%d erasing %d (%d)\n", THISNODE->id, (u32)(*i)->seqno, dns_rcvseq);
		495	dns_rcvpq.erase (i);
		496	goto redo;
		497	}
		498	}
		499
395	dns_packet *	500	dns_packet *
396	vpn::dnsv4_server (dns_packet *pkt)	501	vpn::dnsv4_server (dns_packet *pkt)
397	{	502	{
398	u16 flags = ntohs (pkt->flags);	503	u16 flags = ntohs (pkt->flags);
399		504
…		…
405	if (!(flags & (FLAG_RESPONSE \| FLAG_OP_MASK \| FLAG_TC))	510	if (!(flags & (FLAG_RESPONSE \| FLAG_OP_MASK \| FLAG_TC))
406	&& pkt->qdcount == htons (1))	511	&& pkt->qdcount == htons (1))
407	{	512	{
408	char qname[MAXSIZE];	513	char qname[MAXSIZE];
409	int qlen = pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);	514	int qlen = pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);
410
411	printf ("rcvd packet len %d, id%04x flags%04x q%04x a%04x n%04x a%04x <%s>\n", pkt->len,
412	pkt->id, flags, pkt->qdcount, pkt->ancount, pkt->nscount, pkt->arcount, qname);//D
413		515
414	u16 qtype = (pkt) [offs++] << 8; qtype \|= (pkt) [offs++];	516	u16 qtype = (pkt) [offs++] << 8; qtype \|= (pkt) [offs++];
415	u16 qclass = (pkt) [offs++] << 8; qclass \|= (pkt) [offs++];	517	u16 qclass = (pkt) [offs++] << 8; qclass \|= (pkt) [offs++];
416		518
417	pkt->qdcount = htons (1);	519	pkt->qdcount = htons (1);
…		…
426	if (qclass == RR_CLASS_IN	528	if (qclass == RR_CLASS_IN
427	&& (qtype == RR_TYPE_ANY \|\| qtype == RR_TYPE_TXT)	529	&& (qtype == RR_TYPE_ANY \|\| qtype == RR_TYPE_TXT)
428	&& qlen > dlen + 1	530	&& qlen > dlen + 1
429	&& !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen))	531	&& !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen))
430	{	532	{
431	// correct class, domain, parse	533	// correct class, domain: parse
432	u8 data[MAXSIZE];	534	u8 data[MAXSIZE];
433	int datalen = dns64::decode (data, qname, qlen - dlen - 1);	535	int datalen = dns64::decode (data, qname, qlen - dlen - 1);
434		536
435	for (int i = 0; i < datalen; i++)
436	printf ("%02x ", data[i]);
437	printf ("\n");
438
439
440
441
442	#if 0
443	// now generate reply
444	rep->ancount = htons (1); // one answer RR
445	rep->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);
446
447	(*rep) [offs++] = 0xc0;
448	(rep) [offs++] = 6 2; // same as in query section
449
450	(rep) [offs++] = RR_TYPE_TXT >> 8; (rep) [offs++] = RR_TYPE_TXT;
451	(rep) [offs++] = RR_CLASS_IN >> 8; (rep) [offs++] = RR_CLASS_IN;
452
453	(rep) [offs++] = 0; (rep) [offs++] = 0;
454	(rep) [offs++] = 0; (rep) [offs++] = 0; // TTL
455
456	int dlen = MAX_PKT_SIZE - offs - 2;
457
458	printf ("we have room for %d bytes\n", dlen);
459
460	int rdlen_offs = offs += 2;
461
462	u8 txt[255];
463	txt[0] = 0;
464	txt[1] = 0;
465
466	int txtlen = 2;	537	int client = data[0];
		538	int seqno = ((data[1] << 7) \| (data[2] >> 1)) & SEQNO_MASK;
467		539
468	while (dlen > 1)	540	if (0 < client && client <= conns.size ())
469	{	541	{
470	int sndlen = --dlen;	542	connection *c = conns [client - 1];
471		543
472	if (sndlen + txtlen > 255)	544	redo:
473	sndlen = 255 - txtlen;
474		545
		546	for (vector<dns_rcv *>::iterator i = c->dns_rcvpq.begin ();
		547	i != c->dns_rcvpq.end ();
		548	++i)
		549	if ((*i)->seqno == seqno)
		550	{
		551	// already seen that request: simply reply with the cached reply
		552	dns_rcv r = i;
		553
		554	printf ("DUPLICATE %d\n", htons (r->pkt->id));//D
		555
		556	offs = r->pkt->len;
		557	memcpy (pkt->at (0), r->pkt->at (0), offs);
		558	goto duplicate_request;
		559	}
		560
		561	// new packet, queue
		562	dns_rcv *rcv = new dns_rcv (seqno, data + 3, datalen - 3);
		563	c->dnsv4_receive_rep (rcv);
		564
		565	// now generate reply
		566	pkt->ancount = htons (1); // one answer RR
		567	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);
		568
		569	(*pkt) [offs++] = 0xc0;
		570	(pkt) [offs++] = 6 2; // same as in query section
		571
		572	(pkt) [offs++] = RR_TYPE_TXT >> 8; (pkt) [offs++] = RR_TYPE_TXT;
		573	(pkt) [offs++] = RR_CLASS_IN >> 8; (pkt) [offs++] = RR_CLASS_IN;
		574
		575	(pkt) [offs++] = 0; (pkt) [offs++] = 0;
		576	(pkt) [offs++] = 0; (pkt) [offs++] = 0; // TTL
		577
		578	int dlen = MAX_PKT_SIZE - offs - 2;
		579
		580	// bind doesn't compress well, so reduce further by one label length
475	sndlen = 0;	581	dlen -= qlen;
476		582
		583	int rdlen_offs = offs += 2;
		584
		585	while (c->dns_snddq
		586	&& !c->dns_snddq->empty ()
		587	&& dlen > 1)
		588	{
		589	int txtlen = dlen <= 255 ? dlen - 1 : 255;
		590
		591	if (txtlen > c->dns_snddq->size ())
		592	txtlen = c->dns_snddq->size ();
		593
477	(*rep)[offs++] = sndlen + txtlen;	594	(*pkt)[offs++] = txtlen;
478	memcpy (&((*rep)[offs]), txt, txtlen);	595	memcpy (pkt->at (offs), c->dns_snddq->begin (), txtlen);
479	offs += txtlen;	596	offs += txtlen;
		597	c->dns_snddq->remove (txtlen);
480		598
481	//if (sndlen + txtlen > dns_snddq.	599	dlen -= txtlen + 1;
		600	}
		601
		602	// avoid empty TXT rdata
		603	if (offs == rdlen_offs)
		604	(*pkt)[offs++] = 0;
		605
		606	int rdlen = offs - rdlen_offs;
		607
		608	(*pkt) [rdlen_offs - 2] = rdlen >> 8;
		609	(*pkt) [rdlen_offs - 1] = rdlen;
		610
		611	// now update dns_rcv copy
		612	rcv->pkt->len = offs;
		613	memcpy (rcv->pkt->at (0), pkt->at (0), offs);
		614
		615	duplicate_request: ;
482	}	616	}
483		617	else
484	int rdlen = offs - rdlen_offs;	618	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
485
486	(*rep) [rdlen_offs - 2] = rdlen >> 8;
487	(*rep) [rdlen_offs - 1] = rdlen;
488	#endif
489	}	619	}
490	}
491		620
492	pkt->len = offs;	621	pkt->len = offs;
		622	}
		623
493	return pkt;	624	return pkt;
494	}	625	}
495		626
496	void	627	void
497	vpn::dnsv4_client (dns_packet *pkt)	628	vpn::dnsv4_client (dns_packet *pkt)
…		…
500	int offs = 6 * 2; // skip header	631	int offs = 6 * 2; // skip header
501		632
502	pkt->qdcount = ntohs (pkt->qdcount);	633	pkt->qdcount = ntohs (pkt->qdcount);
503	pkt->ancount = ntohs (pkt->ancount);	634	pkt->ancount = ntohs (pkt->ancount);
504		635
		636	// go through our request list and find the corresponding request
505	for (vector<dns_req *>::iterator i = dns_sndpq.begin ();	637	for (vector<dns_req *>::iterator i = dns_sndpq.begin ();
506	i != dns_sndpq.end ();	638	i != dns_sndpq.end ();
507	++i)	639	++i)
508	if ((*i)->pkt->id == pkt->id)	640	if ((*i)->pkt->id == pkt->id)
509	{	641	{
510	connection c = (i)->conn;	642	connection c = (i)->conn;
511	printf ("GOT RESPONSE id %x %p\n", pkt->id, c);//D	643	int seqno = (*i)->seqno;
		644	u8 data[MAXSIZE], *datap = data;
		645
512	delete *i;	646	delete *i;
513	dns_sndpq.erase (i);	647	dns_sndpq.erase (i);
514		648
515	if (flags & (FLAG_RESPONSE \| FLAG_OP_MASK \| FLAG_TC))	649	if (flags & (FLAG_RESPONSE \| FLAG_OP_MASK \| FLAG_TC))
516	{	650	{
…		…
533	ttl \|= (*pkt) [offs++] << 8;	667	ttl \|= (*pkt) [offs++] << 8;
534	ttl \|= (*pkt) [offs++];	668	ttl \|= (*pkt) [offs++];
535		669
536	u16 rdlen = (pkt) [offs++] << 8; rdlen \|= (pkt) [offs++];	670	u16 rdlen = (pkt) [offs++] << 8; rdlen \|= (pkt) [offs++];
537		671
538	printf ("REPLY %d:%d TTL %d RD %d\n", qtype, qclass, ttl, rdlen);
539
540	offs += rdlen;
541
542	if (MAXSIZE - offs < rdlen)	672	if (rdlen <= MAXSIZE - offs)
543	{	673	{
544	// decode bytes, finally	674	// decode bytes, finally
		675
		676	while (rdlen)
		677	{
		678	int txtlen = (*pkt) [offs++];
		679
		680	assert (txtlen + offs < MAXSIZE - 1);
		681
		682	memcpy (datap, pkt->at (offs), txtlen);
		683	datap += txtlen; offs += txtlen;
		684
		685	rdlen -= txtlen + 1;
		686	}
		687
545	}	688	}
		689
546	}	690	}
547	}	691	}
548		692
		693	// todo: pkt now used
		694	c->dnsv4_receive_rep (new dns_rcv (seqno, data, datap - data));
		695
549	break;	696	break;
550	}	697	}
		698
		699	delete pkt;
551	}	700	}
552		701
553	void	702	void
554	vpn::dnsv4_ev (io_watcher &w, short revents)	703	vpn::dnsv4_ev (io_watcher &w, short revents)
555	{	704	{
…		…
560	socklen_t sa_len = sizeof (sa);	709	socklen_t sa_len = sizeof (sa);
561		710
562	pkt->len = recvfrom (w.fd, &((pkt)[0]), MAXSIZE, 0, (sockaddr )&sa, &sa_len);	711	pkt->len = recvfrom (w.fd, &((pkt)[0]), MAXSIZE, 0, (sockaddr )&sa, &sa_len);
563		712
564	if (pkt->len > 0)	713	if (pkt->len > 0)
		714	{
		715	if (pkt->flags & htons (FLAG_TC))
		716	{
		717	slog (L_WARN, _("DNS request/response truncated, check protocol settings."));
		718	//TODO connection reset
		719	}
		720
565	if (THISNODE->dns_port)	721	if (THISNODE->dns_port)
566	{	722	{
567	pkt = dnsv4_server (pkt);	723	pkt = dnsv4_server (pkt);
568	sendto (w.fd, &((pkt)[0]), pkt->len, 0, (sockaddr )&sa, sa_len);	724	sendto (w.fd, &((pkt)[0]), pkt->len, 0, (sockaddr )&sa, sa_len);
569	}	725	}
570	else	726	else
571	dnsv4_client (pkt);	727	dnsv4_client (pkt);
		728	}
572	}	729	}
573	}	730	}
574		731
575	bool	732	bool
576	connection::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)	733	connection::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
…		…
579	if (!dns_snddq && !dns_rcvdq)	736	if (!dns_snddq && !dns_rcvdq)
580	{	737	{
581	dns_rcvdq = new byte_stream (MAX_BACKLOG * 2);	738	dns_rcvdq = new byte_stream (MAX_BACKLOG * 2);
582	dns_snddq = new byte_stream (MAX_BACKLOG);	739	dns_snddq = new byte_stream (MAX_BACKLOG);
583		740
584	dns_rcvseq = dns_sndseq = 0;	741	//dns_rcvseq = dns_sndseq = 0;
585		742
586	dns_si.set (::conf.dns_forw_host, ::conf.dns_forw_port, PROT_DNSv4);	743	dns_si.set (::conf.dns_forw_host, ::conf.dns_forw_port, PROT_DNSv4);
587	}	744	}
588		745
589	if (!dns_snddq->put (pkt))	746	if (!dns_snddq->put (pkt))
590	return false;	747	return false;
591		748
592	// start timer if neccessary	749	// start timer if neccessary
593	if (!dnsv4_tw.active)	750	if (!THISNODE->dns_port && !dnsv4_tw.active)
594	dnsv4_cb (dnsv4_tw);	751	dnsv4_cb (dnsv4_tw);
595		752
596	return true;	753	return true;
597	}	754	}
598		755
…		…
601	{	758	{
602	// check for timeouts and (re)transmit	759	// check for timeouts and (re)transmit
603	tstamp next = NOW + 60;	760	tstamp next = NOW + 60;
604	dns_req *send = 0;	761	dns_req *send = 0;
605		762
606	slog (L_NOISE, _("dnsv4, %d packets in send queue\n"), vpn->dns_sndpq.size ());
607
608	for (vector<dns_req *>::iterator i = vpn->dns_sndpq.begin ();	763	for (vector<dns_req *>::iterator i = vpn->dns_sndpq.begin ();
609	i != vpn->dns_sndpq.end ();	764	i != vpn->dns_sndpq.end ();
610	++i)	765	++i)
611	{	766	{
612	dns_req r = i;	767	dns_req r = i;
…		…
615	{	770	{
616	if (!send)	771	if (!send)
617	{	772	{
618	send = r;	773	send = r;
619		774
620	slog (L_NOISE, _("dnsv4, send req %d\n"), r->pkt->id);	775	if (r->retry)//D
		776	printf ("req %d, retry %d\n", r->pkt->id, r->retry);
621	r->retry++;	777	r->retry++;
622	r->next = NOW + r->retry;	778	r->next = NOW + r->retry;
623	}	779	}
624	}	780	}
625		781
…		…
627	next = r->next;	783	next = r->next;
628	}	784	}
629		785
630	if (!send	786	if (!send
631	&& vpn->dns_sndpq.size () < MAX_OUTSTANDING)	787	&& vpn->dns_sndpq.size () < MAX_OUTSTANDING)
632	send = new dns_req (this, dns_sndseq++, dns_snddq);	788	{
		789	send = new dns_req (this);
		790	send->gen_stream_req (dns_sndseq, dns_snddq);
		791	vpn->dns_sndpq.push_back (send);
		792
		793	dns_sndseq = (dns_sndseq + 1) & SEQNO_MASK;
		794	}
633		795
634	tstamp min_next = NOW + (1. / (tstamp)MAX_RATE);	796	tstamp min_next = NOW + (1. / (tstamp)MAX_RATE);
635		797
636	if (send)	798	if (send)
637	{	799	{

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Comparing gvpe/src/vpn_dns.C (file contents): Revision 1.4 by pcg, Wed Mar 2 05:49:31 2005 UTC vs. Revision 1.7 by pcg, Thu Mar 3 16:54:34 2005 UTC

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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.4 by pcg, Wed Mar 2 05:49:31 2005 UTC vs.
Revision 1.7 by pcg, Thu Mar 3 16:54:34 2005 UTC