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

Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.8 by pcg, Fri Mar 4 03:43:09 2005 UTC vs.
Revision 1.18 by pcg, Sat Mar 5 19:13:16 2005 UTC

…		…
43		43
44	#include "netcompat.h"	44	#include "netcompat.h"
45		45
46	#include "vpn.h"	46	#include "vpn.h"
47		47
48	#define MIN_RETRY 1.	48	#define MIN_POLL_INTERVAL .02 // how often to poll minimally when the server has data
49	#define MAX_RETRY 60.	49	#define MAX_POLL_INTERVAL 6. // how often to poll minimally when the server has no data
		50	#define ACTIVITY_INTERVAL 5.
50		51
		52	#define INITIAL_TIMEOUT 0.1 // retry timeouts
		53	#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn
		54
		55	#define MIN_SEND_INTERVAL 0.01 // wait at least this time between sending requests
		56	#define MAX_SEND_INTERVAL 0.5 // optimistic?
		57
51	#define MAX_OUTSTANDING 400 // max. outstanding requests	58	#define MAX_OUTSTANDING 10 // max. outstanding requests
52	#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING	59	#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog
53	#define MAX_RATE 10000 // requests/s
54	#define MAX_BACKLOG (10*1024) // size of protocol backlog, must be > MAXSIZE	60	#define MAX_BACKLOG (100*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
55		61
56	#define MAX_DOMAIN_SIZE 220 // 255 is legal limit, but bind doesn't compress well	62	#define MAX_DOMAIN_SIZE 220 // 255 is legal limit, but bind doesn't compress well
57	// 240 leaves about 4 bytes of server reply data	63	// 240 leaves about 4 bytes of server reply data
58	// every two request byte sless give room for one reply byte	64	// every two request bytes less give room for one reply byte
59		65
60	// seqno has 12 bits (3 bytes a 4 bits in the header)
61	#define SEQNO_MASK 0x7fff	66	#define SEQNO_MASK 0x3fff
62	#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )	67	#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
63		68
64	#define MAX_LBL_SIZE 63	69	#define MAX_LBL_SIZE 63
65	#define MAX_PKT_SIZE 512	70	#define MAX_PKT_SIZE 512
66		71
		72	#define RR_TYPE_A 1
		73	#define RR_TYPE_NULL 10
67	#define RR_TYPE_TXT 16	74	#define RR_TYPE_TXT 16
68	#define RR_TYPE_ANY 255	75	#define RR_TYPE_ANY 255
		76
69	#define RR_CLASS_IN 1	77	#define RR_CLASS_IN 1
		78
		79	#define CMD_IP_1 207
		80	#define CMD_IP_2 46
		81	#define CMD_IP_3 236
		82	#define CMD_IP_RST 29
		83	#define CMD_IP_SYN 113
		84	#define CMD_IP_REJ 32
70		85
71	// works for cmaps up to 255 (not 256!)	86	// works for cmaps up to 255 (not 256!)
72	struct charmap	87	struct charmap
73	{	88	{
74	enum { INVALID = (u8)255 };	89	enum { INVALID = (u8)255 };
…		…
154	return dec_len [len];	169	return dec_len [len];
155	}	170	}
156		171
157	unsigned int basecoder::encode (char dst, u8 src, unsigned int len)	172	unsigned int basecoder::encode (char dst, u8 src, unsigned int len)
158	{	173	{
159	if (!len)	174	if (!len \|\| len > MAX_DEC_LEN)
160	return 0;	175	return 0;
161		176
162	int elen = encode_len (len);	177	int elen = encode_len (len);
163		178
164	mp_limb_t m [MAX_LIMBS];	179	mp_limb_t m [MAX_LIMBS];
…		…
183	return elen;	198	return elen;
184	}	199	}
185		200
186	unsigned int basecoder::decode (u8 dst, char src, unsigned int len)	201	unsigned int basecoder::decode (u8 dst, char src, unsigned int len)
187	{	202	{
188	if (!len)	203	if (!len \|\| len > MAX_ENC_LEN)
189	return 0;	204	return 0;
190		205
191	u8 src_ [MAX_ENC_LEN];	206	u8 src_ [MAX_ENC_LEN];
192	unsigned int elen = 0;	207	unsigned int elen = 0;
193		208
…		…
240	}	255	}
241	abort ();	256	abort ();
242	}	257	}
243	#endif	258	#endif
244		259
245	// the following sequence has been crafted to	260	//static basecoder cdc64 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI-");
246	// a) look somewhat random
247	// b) the even (and odd) indices never share the same character as upper/lowercase
248	// the "_" is not valid but widely accepted (all octets should be supported, but let's be conservative)
249	// the other sequences are obviously derived
250	//static basecoder cdc63 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");	261	//static basecoder cdc63 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");
251	static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");	262	static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");
252	//static basecoder cdc36 ("dphzr06qmjkb34tsvl81xaef92wgyo57ucni"); // unused as of yet	263	//static basecoder cdc36 ("dphzr06qmjkb34tsvl81xaef92wgyo57ucni"); // unused as of yet
253	static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");	264	static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");
254		265
255	/////////////////////////////////////////////////////////////////////////////	266	/////////////////////////////////////////////////////////////////////////////
256		267
257	#define HDRSIZE 6	268	#define HDRSIZE 6
258		269
259	inline void encode_header (char *data, int clientid, int seqno)	270	inline void encode_header (char *data, int clientid, int seqno, int retry = 0)
260	{	271	{
261	u8 hdr[3] = { clientid, seqno >> 8, seqno };	272	seqno &= SEQNO_MASK;
		273
		274	u8 hdr[3] = {
		275	clientid,
		276	(seqno >> 8) \| (retry << 6),
		277	seqno,
		278	};
262		279
263	assert (clientid < 256);	280	assert (clientid < 256);
264		281
265	cdc26.encode (data, hdr, 3);	282	cdc26.encode (data, hdr, 3);
266	}	283	}
…		…
269	{	286	{
270	u8 hdr[3];	287	u8 hdr[3];
271		288
272	cdc26.decode (hdr, data, HDRSIZE);	289	cdc26.decode (hdr, data, HDRSIZE);
273		290
274	printf ("DEC %02x %02x %02x %02x\n", hdr[0], hdr[1], hdr[2], hdr[3]);
275
276	clientid = hdr[0];	291	clientid = hdr[0];
277	seqno = (hdr[1] << 8) \| hdr[2];	292	seqno = ((hdr[1] << 8) \| hdr[2]) & SEQNO_MASK;
278	}	293	}
279		294
280	/////////////////////////////////////////////////////////////////////////////	295	/////////////////////////////////////////////////////////////////////////////
281		296
282	struct byte_stream	297	struct byte_stream
…		…
311	}	326	}
312		327
313	void byte_stream::remove (int count)	328	void byte_stream::remove (int count)
314	{	329	{
315	if (count > fill)	330	if (count > fill)
316	abort ();	331	assert (count <= fill);
317		332
318	memmove (data, data + count, fill -= count);	333	memmove (data, data + count, fill -= count);
319	}	334	}
320		335
321	bool byte_stream::put (u8 *data, unsigned int datalen)	336	bool byte_stream::put (u8 *data, unsigned int datalen)
…		…
334	return false;	349	return false;
335		350
336	data [fill++] = pkt->len >> 8;	351	data [fill++] = pkt->len >> 8;
337	data [fill++] = pkt->len;	352	data [fill++] = pkt->len;
338		353
339	memcpy (data + fill, &((*pkt)[0]), pkt->len); fill += pkt->len;	354	memcpy (data + fill, pkt->at (0), pkt->len); fill += pkt->len;
340		355
341	return true;	356	return true;
342	}	357	}
343		358
344	vpn_packet *byte_stream::get ()	359	vpn_packet *byte_stream::get ()
345	{	360	{
		361	unsigned int len;
		362
		363	for (;;)
		364	{
346	int len = (data [0] << 8) \| data [1];	365	len = (data [0] << 8) \| data [1];
347		366
348	if (len > MAXSIZE && fill >= 2)	367	if (len <= MAXSIZE \|\| fill < 2)
349	abort (); // TODO handle this gracefully, connection reset	368	break;
350		369
		370	// TODO: handle this better than skipping, e.g. by reset
		371	slog (L_DEBUG, _("DNS: corrupted packet stream skipping a byte..."));
		372	remove (1);
		373	}
		374
351	if (fill < len + 2)	375	if (fill < len + 2)
352	return 0;	376	return 0;
353		377
354	vpn_packet *pkt = new vpn_packet;	378	vpn_packet *pkt = new vpn_packet;
355		379
356	pkt->len = len;	380	pkt->len = len;
357	memcpy (&((*pkt)[0]), data + 2, len);	381	memcpy (pkt->at (0), data + 2, len);
358	remove (len + 2);	382	remove (len + 2);
359		383
360	return pkt;	384	return pkt;
361	}	385	}
362		386
363	/////////////////////////////////////////////////////////////////////////////	387	/////////////////////////////////////////////////////////////////////////////
364		388
365	#define FLAG_QUERY ( 0 << 15)	389	#define FLAG_QUERY ( 0 << 15)
366	#define FLAG_RESPONSE ( 1 << 15)	390	#define FLAG_RESPONSE ( 1 << 15)
367	#define FLAG_OP_MASK (15 << 14)	391	#define FLAG_OP_MASK (15 << 11)
368	#define FLAG_OP_QUERY ( 0 << 11)	392	#define FLAG_OP_QUERY ( 0 << 11)
369	#define FLAG_AA ( 1 << 10)	393	#define FLAG_AA ( 1 << 10)
370	#define FLAG_TC ( 1 << 9)	394	#define FLAG_TC ( 1 << 9)
371	#define FLAG_RD ( 1 << 8)	395	#define FLAG_RD ( 1 << 8)
372	#define FLAG_RA ( 1 << 7)	396	#define FLAG_RA ( 1 << 7)
…		…
379	#define FLAG_RCODE_REFUSED ( 5 << 0)	403	#define FLAG_RCODE_REFUSED ( 5 << 0)
380		404
381	#define DEFAULT_CLIENT_FLAGS (FLAG_QUERY \| FLAG_OP_QUERY \| FLAG_RD)	405	#define DEFAULT_CLIENT_FLAGS (FLAG_QUERY \| FLAG_OP_QUERY \| FLAG_RD)
382	#define DEFAULT_SERVER_FLAGS (FLAG_RESPONSE \| FLAG_OP_QUERY \| FLAG_AA \| FLAG_RD \| FLAG_RA)	406	#define DEFAULT_SERVER_FLAGS (FLAG_RESPONSE \| FLAG_OP_QUERY \| FLAG_AA \| FLAG_RD \| FLAG_RA)
383		407
		408	struct dns_cfg
		409	{
		410	static int next_uid;
		411
		412	u8 id1, id2, id3, id4;
		413	u8 version;
		414	u8 rrtype;
		415	u8 flags;
		416	u8 def_ttl;
		417	u8 rcv_cdc;
		418	u8 snd_cdc;
		419	u16 max_size;
		420	u16 client;
		421	u16 uid; // to make request unique
		422
		423	u8 reserved[8];
		424
		425	void reset (int clientid);
		426	bool valid ();
		427	};
		428
		429	int dns_cfg::next_uid;
		430
		431	void dns_cfg::reset (int clientid)
		432	{
		433	id1 = 'G';
		434	id2 = 'V';
		435	id3 = 'P';
		436	id4 = 'E';
		437
		438	version = 1;
		439
		440	rrtype = RR_TYPE_TXT;
		441	flags = 0;
		442	def_ttl = 1;
		443	rcv_cdc = 0;
		444	snd_cdc = 62;
		445	max_size = ntohs (MAX_PKT_SIZE);
		446	client = ntohs (clientid);
		447	uid = next_uid++;
		448
		449	memset (reserved, 0, 8);
		450	}
		451
		452	bool dns_cfg::valid ()
		453	{
		454	return id1 == 'G'
		455	&& id2 == 'V'
		456	&& id3 == 'P'
		457	&& id4 == 'E'
		458	&& version == 1
		459	&& flags == 0
		460	&& rcv_cdc == 0
		461	&& snd_cdc == 62
		462	&& max_size == ntohs (MAX_PKT_SIZE);
		463	}
		464
384	struct dns_packet : net_packet	465	struct dns_packet : net_packet
385	{	466	{
386	u16 id;	467	u16 id;
387	u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4	468	u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4
388	u16 qdcount, ancount, nscount, arcount;	469	u16 qdcount, ancount, nscount, arcount;
…		…
426	return data - orig;	507	return data - orig;
427	}	508	}
428		509
429	/////////////////////////////////////////////////////////////////////////////	510	/////////////////////////////////////////////////////////////////////////////
430		511
431	struct dns_req
432	{
433	dns_packet *pkt;
434	tstamp next;
435	int retry;
436	connection *conn;
437	int seqno;
438
439	dns_req (connection *c);
440	void gen_stream_req (int seqno, byte_stream *stream);
441	};
442
443	static u16 dns_id = 12098; // TODO: should be per-vpn	512	static u16 dns_id = 0; // TODO: should be per-vpn
444		513
445	static u16 next_id ()	514	static u16 next_id ()
446	{	515	{
		516	if (!dns_id)
		517	dns_id = time (0);
		518
447	// the simplest lsfr with periodicity 65535 i could find	519	// the simplest lsfr with periodicity 65535 i could find
448	dns_id = (dns_id << 1)	520	dns_id = (dns_id << 1)
449	\| (((dns_id >> 1)	521	\| (((dns_id >> 1)
450	^ (dns_id >> 2)	522	^ (dns_id >> 2)
451	^ (dns_id >> 4)	523	^ (dns_id >> 4)
452	^ (dns_id >> 15)) & 1);	524	^ (dns_id >> 15)) & 1);
453		525
454	return dns_id;	526	return dns_id;
455	}	527	}
456		528
457	dns_req::dns_req (connection *c)	529	struct dns_rcv;
458	: conn (c)	530	struct dns_snd;
		531
		532	struct dns_connection
459	{	533	{
460	next = 0;	534	connection *c;
		535	struct vpn *vpn;
		536
		537	dns_cfg cfg;
		538
		539	bool established;
		540
		541	tstamp last_received;
		542	tstamp last_sent;
		543	double last_latency;
		544	double poll_interval, send_interval;
		545
		546	vector<dns_rcv *> rcvpq;
		547
		548	byte_stream rcvdq; int rcvseq;
		549	byte_stream snddq; int sndseq;
		550
		551	void time_cb (time_watcher &w); time_watcher tw;
		552	void receive_rep (dns_rcv *r);
		553
		554	dns_connection (connection *c);
		555	~dns_connection ();
		556	};
		557
		558	struct dns_snd
		559	{
		560	dns_packet *pkt;
		561	tstamp timeout, sent;
		562	int retry;
		563	struct dns_connection *dns;
		564	int seqno;
		565	bool stdhdr;
		566
		567	void gen_stream_req (int seqno, byte_stream &stream);
		568	void gen_syn_req ();
		569
		570	dns_snd (dns_connection *dns);
		571	~dns_snd ();
		572	};
		573
		574	dns_snd::dns_snd (dns_connection *dns)
		575	: dns (dns)
		576	{
		577	timeout = 0;
461	retry = 0;	578	retry = 0;
		579	seqno = 0;
		580	sent = NOW;
		581	stdhdr = false;
462		582
463	pkt = new dns_packet;	583	pkt = new dns_packet;
464		584
465	pkt->id = next_id ();	585	pkt->id = next_id ();
466	}	586	}
467		587
		588	dns_snd::~dns_snd ()
		589	{
		590	delete pkt;
		591	}
		592
		593	static void append_domain (dns_packet &pkt, int &offs, const char *domain)
		594	{
		595	// add tunnel domain
		596	for (;;)
		597	{
		598	const char *end = strchr (domain, '.');
		599
		600	if (!end)
		601	end = domain + strlen (domain);
		602
		603	int len = end - domain;
		604
		605	pkt [offs++] = len;
		606	memcpy (pkt.at (offs), domain, len);
		607	offs += len;
		608
		609	if (!*end)
		610	break;
		611
		612	domain = end + 1;
		613	}
		614	}
		615
468	void dns_req::gen_stream_req (int seqno, byte_stream *stream)	616	void dns_snd::gen_stream_req (int seqno, byte_stream &stream)
469	{	617	{
		618	stdhdr = true;
470	this->seqno = seqno;	619	this->seqno = seqno;
		620
		621	timeout = NOW + INITIAL_TIMEOUT;
471		622
472	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);	623	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
473	pkt->qdcount = htons (1);	624	pkt->qdcount = htons (1);
474		625
475	int offs = 6*2;	626	int offs = 6*2;
…		…
480	char enc[256], *encp = enc;	631	char enc[256], *encp = enc;
481	encode_header (enc, THISNODE->id, seqno);	632	encode_header (enc, THISNODE->id, seqno);
482		633
483	int datalen = cdc62.decode_len (dlen - (dlen + MAX_LBL_SIZE - 1) / MAX_LBL_SIZE - HDRSIZE);	634	int datalen = cdc62.decode_len (dlen - (dlen + MAX_LBL_SIZE - 1) / MAX_LBL_SIZE - HDRSIZE);
484		635
485	if (datalen > stream->size ())	636	if (datalen > stream.size ())
486	datalen = stream->size ();	637	datalen = stream.size ();
487		638
488	int enclen = cdc62.encode (enc + HDRSIZE, stream->begin (), datalen) + HDRSIZE;	639	int enclen = cdc62.encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE;
489
490	printf ("cdc62.encode %d->%d:%02x %02x %02x %02x\n", datalen, enclen,
491	stream->begin ()[0],
492	stream->begin ()[1],
493	stream->begin ()[2],
494	stream->begin ()[3]);
495
496	stream->remove (datalen);	640	stream.remove (datalen);
497		641
498	while (enclen)	642	while (enclen)
499	{	643	{
500	int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE;	644	int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE;
501		645
…		…
506	encp += lbllen;	650	encp += lbllen;
507		651
508	enclen -= lbllen;	652	enclen -= lbllen;
509	}	653	}
510		654
511	const char *suffix = THISNODE->domain;	655	append_domain (*pkt, offs, THISNODE->domain);
512
513	// add tunnel domain
514	for (;;)
515	{
516	const char *end = strchr (suffix, '.');
517
518	if (!end)
519	end = suffix + strlen (suffix);
520
521	int len = end - suffix;
522
523	(*pkt)[offs++] = len;
524	memcpy (&((*pkt)[offs]), suffix, len);
525	offs += len;
526
527	if (!*end)
528	break;
529
530	suffix = end + 1;
531	}
532		656
533	(*pkt)[offs++] = 0;	657	(*pkt)[offs++] = 0;
534	(pkt)[offs++] = RR_TYPE_ANY >> 8; (pkt)[offs++] = RR_TYPE_ANY;	658	(pkt)[offs++] = RR_TYPE_ANY >> 8; (pkt)[offs++] = RR_TYPE_ANY;
		659	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;
		660
		661	pkt->len = offs;
		662	}
		663
		664	void dns_snd::gen_syn_req ()
		665	{
		666	timeout = NOW + INITIAL_SYN_TIMEOUT;
		667
		668	printf ("send syn\n");//D
		669
		670	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
		671	pkt->qdcount = htons (1);
		672
		673	int offs = 6 * 2;
		674
		675	int elen = cdc26.encode ((char )pkt->at (offs + 1), (u8 )&dns->cfg, sizeof (dns_cfg));
		676
		677	assert (elen <= MAX_LBL_SIZE);
		678
		679	(*pkt)[offs] = elen;
		680	offs += elen + 1;
		681	append_domain (*pkt, offs, THISNODE->domain);
		682
		683	(*pkt)[offs++] = 0;
		684	(pkt)[offs++] = RR_TYPE_A >> 8; (pkt)[offs++] = RR_TYPE_A;
535	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;	685	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;
536		686
537	pkt->len = offs;	687	pkt->len = offs;
538	}	688	}
539		689
…		…
558	{	708	{
559	delete pkt;	709	delete pkt;
560	}	710	}
561		711
562	/////////////////////////////////////////////////////////////////////////////	712	/////////////////////////////////////////////////////////////////////////////
563		713
564	struct dns_cfg	714	dns_connection::dns_connection (connection *c)
		715	: c (c)
		716	, rcvdq (MAX_BACKLOG * 2)
		717	, snddq (MAX_BACKLOG * 2)
		718	, tw (this, &dns_connection::time_cb)
565	{	719	{
566	u8 id1, id2, id3;	720	vpn = c->vpn;
567	u8 def_ttl;
568	u8 unused1;
569	u16 max_size;
570	u8 flags1, flags2;
571	};
572		721
		722	established = false;
		723
		724	rcvseq = sndseq = 0;
		725
		726	last_sent = last_received = 0;
		727	poll_interval = MIN_POLL_INTERVAL;
		728	send_interval = 0.5; // starting rate
		729	last_latency = INITIAL_TIMEOUT;
		730	}
		731
		732	dns_connection::~dns_connection ()
		733	{
		734	for (vector<dns_rcv *>::iterator i = rcvpq.begin ();
		735	i != rcvpq.end ();
		736	++i)
		737	delete *i;
		738	}
		739
573	void connection::dnsv4_receive_rep (struct dns_rcv *r)	740	void dns_connection::receive_rep (dns_rcv *r)
574	{	741	{
		742	if (r->datalen)
		743	{
		744	last_received = NOW;
		745	tw.trigger ();
		746
		747	poll_interval = send_interval;
		748	}
		749	else
		750	{
		751	poll_interval *= 1.5;
		752	if (poll_interval > MAX_POLL_INTERVAL)
		753	poll_interval = MAX_POLL_INTERVAL;
		754	}
		755
575	dns_rcvpq.push_back (r);	756	rcvpq.push_back (r);
576		757
577	printf ("%d got inketc %d (%02x %02x %02x %02x)\n", THISNODE->id, r->seqno
578	,r->data[0]
579	,r->data[1]
580	,r->data[2]
581	,r->data[3]
582	);
583	redo:	758	redo:
584		759
585	// find next packet	760	// find next packet
586	for (vector<dns_rcv *>::iterator i = dns_rcvpq.end (); i-- != dns_rcvpq.begin (); )	761	for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); )
587	if (SEQNO_EQ (dns_rcvseq, (*i)->seqno))	762	if (SEQNO_EQ (rcvseq, (*i)->seqno))
588	{	763	{
589	// enter the packet into our input stream	764	// enter the packet into our input stream
590	r = *i;	765	r = *i;
591		766
592	printf ("%d checking for older packet %d\n", THISNODE->id, dns_rcvseq);
593	// remove the oldest packet, look forward, as it's oldest first	767	// remove the oldest packet, look forward, as it's oldest first
594	for (vector<dns_rcv *>::iterator j = dns_rcvpq.begin (); j != dns_rcvpq.end (); ++j)	768	for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j)
595	if (SEQNO_EQ ((*j)->seqno, dns_rcvseq - MAX_WINDOW))	769	if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW))
596	{	770	{
597	printf ("%d removing %d\n", THISNODE->id, (*j)->seqno);
598	delete *j;	771	delete *j;
599	dns_rcvpq.erase (j);	772	rcvpq.erase (j);
600	break;	773	break;
601	}	774	}
602		775
603	dns_rcvseq = (dns_rcvseq + 1) & SEQNO_MASK;	776	rcvseq = (rcvseq + 1) & SEQNO_MASK;
604		777
605	if (!dns_snddq && !dns_rcvdq)	778	if (!rcvdq.put (r->data, r->datalen))
606	{	779	{
607	dns_rcvdq = new byte_stream (MAX_BACKLOG * 2);	780	slog (L_ERR, "DNS: !rcvdq.put (r->data, r->datalen)");
608	dns_snddq = new byte_stream (MAX_BACKLOG);	781	abort (); // MUST never overflow, can be caused by data corruption, TODO
609
610	dns_si.set (::conf.dns_forw_host, ::conf.dns_forw_port, PROT_DNSv4);
611	}	782	}
612		783
613	if (!dns_rcvdq->put (r->data, r->datalen))
614	abort (); // MUST never overflow, can be caused by data corruption, TODO
615
616	while (vpn_packet *pkt = dns_rcvdq->get ())	784	while (vpn_packet *pkt = rcvdq.get ())
617	{	785	{
618	sockinfo si;	786	sockinfo si;
619	si.host = 0; si.port = 0; si.prot = PROT_DNSv4;	787	si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4;
620		788
621	vpn->recv_vpn_packet (pkt, si);	789	vpn->recv_vpn_packet (pkt, si);
		790
		791	delete pkt;
622	}	792	}
623		793
624	// check for further packets	794	// check for further packets
625	goto redo;	795	goto redo;
626	}	796	}
627	}	797	}
628		798
629	dns_packet *	799	void
630	vpn::dnsv4_server (dns_packet *pkt)	800	vpn::dnsv4_server (dns_packet &pkt)
631	{	801	{
632	u16 flags = ntohs (pkt->flags);	802	u16 flags = ntohs (pkt.flags);
633		803
634	//memcpy (&((rep)[0]), &((pkt)[0]), pkt->len);
635	int offs = 6 * 2; // skip header	804	int offs = 6 * 2; // skip header
636		805
637	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);	806	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
638		807
639	if (!(flags & (FLAG_RESPONSE \| FLAG_OP_MASK \| FLAG_TC))	808	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK))
640	&& pkt->qdcount == htons (1))	809	&& pkt.qdcount == htons (1))
641	{	810	{
642	char qname[MAXSIZE];	811	char qname[MAXSIZE];
643	int qlen = pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);	812	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
644		813
645	u16 qtype = (pkt) [offs++] << 8; qtype \|= (pkt) [offs++];	814	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];
646	u16 qclass = (pkt) [offs++] << 8; qclass \|= (pkt) [offs++];	815	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];
647		816
648	pkt->qdcount = htons (1);	817	pkt.qdcount = htons (1);
649	pkt->ancount = 0;	818	pkt.ancount = 0;
650	pkt->nscount = 0; // should be self, as other nameservers reply like this	819	pkt.nscount = 0; // should be self, as other nameservers reply like this
651	pkt->arcount = 0; // a record for self, as other nameservers reply like this	820	pkt.arcount = 0; // a record for self, as other nameservers reply like this
652		821
653	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_NXDOMAIN);	822	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_SERVFAIL);
654		823
655	int dlen = strlen (THISNODE->domain);	824	int dlen = strlen (THISNODE->domain);
656		825
657	if (qclass == RR_CLASS_IN	826	if (qclass == RR_CLASS_IN
658	&& (qtype == RR_TYPE_ANY \|\| qtype == RR_TYPE_TXT)
659	&& qlen > dlen + 1 + HDRSIZE	827	&& qlen > dlen + 1
660	&& !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen))	828	&& !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen))
661	{	829	{
662	// correct class, domain: parse	830	// now generate reply
663	int client, seqno;	831	pkt.ancount = htons (1); // one answer RR
664	decode_header (qname, client, seqno);	832	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);
665		833
666	u8 data[MAXSIZE];	834	if ((qtype == RR_TYPE_ANY
667	int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));	835	\|\| qtype == RR_TYPE_TXT
668		836	\|\| qtype == RR_TYPE_NULL)
669	printf ("cdc62.decode %d(%d): %02x %02x %02x %02x\n",
670	qlen - (dlen + 1 + HDRSIZE), datalen	837	&& qlen > dlen + 1 + HDRSIZE)
671	,data[0]
672	,data[1]
673	,data[2]
674	,data[3]);
675
676	printf ("SRV got %d <%.*s>\n", seqno, qlen, qname + HDRSIZE);//D
677	printf ("SRV got %d <%.*s>\n", seqno, qlen - (dlen + 1 + HDRSIZE), qname + HDRSIZE);//D
678
679	if (0 < client && client <= conns.size ())
680	{	838	{
681	connection *c = conns [client - 1];	839	// correct class, domain: parse
		840	int client, seqno;
		841	decode_header (qname, client, seqno);
682		842
683	for (vector<dns_rcv *>::iterator i = c->dns_rcvpq.end (); i-- != c->dns_rcvpq.begin (); )	843	u8 data[MAXSIZE];
684	if (SEQNO_EQ ((*i)->seqno, seqno))	844	int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
685	{
686	// already seen that request: simply reply with the cached reply
687	dns_rcv r = i;
688		845
689	printf ("DUPLICATE %d\n", htons (r->pkt->id));//D	846	if (0 < client && client <= conns.size ())
690
691	memcpy (pkt->at (0), r->pkt->at (0), offs = r->pkt->len);
692	pkt->id = r->pkt->id;
693	goto duplicate_request;
694	}
695
696	// new packet, queue
697	dns_rcv *rcv = new dns_rcv (seqno, data, datalen);
698	c->dnsv4_receive_rep (rcv);
699
700	// now generate reply
701	pkt->ancount = htons (1); // one answer RR
702	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);
703
704	(*pkt) [offs++] = 0xc0;
705	(pkt) [offs++] = 6 2; // same as in query section
706
707	(pkt) [offs++] = RR_TYPE_TXT >> 8; (pkt) [offs++] = RR_TYPE_TXT;
708	(pkt) [offs++] = RR_CLASS_IN >> 8; (pkt) [offs++] = RR_CLASS_IN;
709
710	(pkt) [offs++] = 0; (pkt) [offs++] = 0;
711	(pkt) [offs++] = 0; (pkt) [offs++] = 0; // TTL
712
713	int dlen = MAX_PKT_SIZE - offs - 2;
714
715	// bind doesn't compress well, so reduce further by one label length
716	dlen -= qlen;
717
718	int rdlen_offs = offs += 2;
719
720	while (c->dns_snddq
721	&& !c->dns_snddq->empty ()
722	&& dlen > 1)
723	{	847	{
		848	connection *c = conns [client - 1];
		849	dns_connection *dns = c->dns;
		850	dns_rcv *rcv;
		851	bool in_seq;
		852
		853	if (dns)
		854	{
		855	for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
		856	if (SEQNO_EQ ((*i)->seqno, seqno))
		857	{
		858	// already seen that request: simply reply with the cached reply
		859	dns_rcv r = i;
		860
		861	slog (L_DEBUG, "DNS: duplicate packet received ID %d, SEQ %d", htons (r->pkt->id), seqno);
		862
		863	// refresh header & id, as the retry count could have changed
		864	memcpy (r->pkt->at (6 * 2 + 1), pkt.at (6 * 2 + 1), HDRSIZE);
		865	r->pkt->id = pkt.id;
		866
		867	memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
		868
		869	goto duplicate_request;
		870	}
		871
		872	in_seq = dns->rcvseq == seqno;
		873
		874	// new packet, queue
		875	rcv = new dns_rcv (seqno, data, datalen);
		876	dns->receive_rep (rcv);
		877	}
		878
		879	pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section
		880
		881	int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;
		882	pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type
		883	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
		884	pkt [offs++] = 0; pkt [offs++] = 0;
		885	pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
		886
		887	int rdlen_offs = offs += 2;
		888
		889	int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs;
		890	// bind doesn't compress well, so reduce further by one label length
		891	dlen -= qlen;
		892
		893	if (dns)
		894	{
		895	// only put data into in-order sequence packets, if
		896	// we receive out-of-order packets we generate empty
		897	// replies
		898	while (dlen > 1 && !dns->snddq.empty () && in_seq)
		899	{
724	int txtlen = dlen <= 255 ? dlen - 1 : 255;	900	int txtlen = dlen <= 255 ? dlen - 1 : 255;
725		901
726	if (txtlen > c->dns_snddq->size ())	902	if (txtlen > dns->snddq.size ())
727	txtlen = c->dns_snddq->size ();	903	txtlen = dns->snddq.size ();
728		904
729	(*pkt)[offs++] = txtlen;	905	pkt[offs++] = txtlen;
730	memcpy (pkt->at (offs), c->dns_snddq->begin (), txtlen);	906	memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
731	offs += txtlen;	907	offs += txtlen;
732	c->dns_snddq->remove (txtlen);	908	dns->snddq.remove (txtlen);
733		909
734	dlen -= txtlen + 1;	910	dlen -= txtlen + 1;
		911	}
		912
		913	// avoid empty TXT rdata
		914	if (offs == rdlen_offs)
		915	pkt[offs++] = 0;
		916
		917	slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
		918	}
		919	else
		920	{
		921	// send RST
		922	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
		923	pkt [offs++] = CMD_IP_RST;
		924	}
		925
		926	int rdlen = offs - rdlen_offs;
		927
		928	pkt [rdlen_offs - 2] = rdlen >> 8;
		929	pkt [rdlen_offs - 1] = rdlen;
		930
		931	if (dns)
		932	{
		933	// now update dns_rcv copy
		934	rcv->pkt->len = offs;
		935	memcpy (rcv->pkt->at (0), pkt.at (0), offs);
		936	}
		937
		938	duplicate_request: ;
735	}	939	}
736		940	else
737	// avoid empty TXT rdata	941	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
738	if (offs == rdlen_offs)
739	(*pkt)[offs++] = 0;
740
741	int rdlen = offs - rdlen_offs;
742
743	(*pkt) [rdlen_offs - 2] = rdlen >> 8;
744	(*pkt) [rdlen_offs - 1] = rdlen;
745
746	// now update dns_rcv copy
747	rcv->pkt->len = offs;
748	memcpy (rcv->pkt->at (0), pkt->at (0), offs);
749
750	duplicate_request: ;
751	}	942	}
752	else	943	else if (qtype == RR_TYPE_A
753	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);	944	&& qlen > dlen + 1 + cdc26.encode_len (sizeof (dns_cfg)))
		945	{
		946	dns_cfg cfg;
		947	cdc26.decode ((u8 *)&cfg, qname, cdc26.encode_len (sizeof (dns_cfg)));
		948	int client = ntohs (cfg.client);
		949
		950	pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section
		951
		952	pkt [offs++] = RR_TYPE_A >> 8; pkt [offs++] = RR_TYPE_A; // type
		953	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
		954	pkt [offs++] = 0; pkt [offs++] = 0;
		955	pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
		956	pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
		957
		958	slog (L_INFO, _("DNS: client %d tries to connect"), client);
		959
		960	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
		961	pkt [offs++] = CMD_IP_REJ;
		962
		963	if (0 < client && client <= conns.size ())
		964	{
		965	connection *c = conns [client - 1];
		966
		967	if (cfg.valid ())
		968	{
		969	pkt [offs - 1] = CMD_IP_SYN;
		970
		971	delete c->dns;
		972	c->dns = new dns_connection (c);
		973	c->dns->cfg = cfg;
		974	}
		975	}
		976	}
754	}	977	}
755		978
756	pkt->len = offs;	979	pkt.len = offs;
757	}	980	}
758
759	return pkt;
760	}	981	}
761		982
762	void	983	void
763	vpn::dnsv4_client (dns_packet *pkt)	984	vpn::dnsv4_client (dns_packet &pkt)
764	{	985	{
765	u16 flags = ntohs (pkt->flags);	986	u16 flags = ntohs (pkt.flags);
766	int offs = 6 * 2; // skip header	987	int offs = 6 * 2; // skip header
767		988
768	pkt->qdcount = ntohs (pkt->qdcount);	989	pkt.qdcount = ntohs (pkt.qdcount);
769	pkt->ancount = ntohs (pkt->ancount);	990	pkt.ancount = ntohs (pkt.ancount);
770		991
771	// go through our request list and find the corresponding request	992	// go through our request list and find the corresponding request
772	for (vector<dns_req *>::iterator i = dns_sndpq.begin ();	993	for (vector<dns_snd *>::iterator i = dns_sndpq.begin ();
773	i != dns_sndpq.end ();	994	i != dns_sndpq.end ();
774	++i)	995	++i)
775	if ((*i)->pkt->id == pkt->id)	996	if ((*i)->pkt->id == pkt.id)
776	{	997	{
		998	dns_connection dns = (i)->dns;
777	connection c = (i)->conn;	999	connection *c = dns->c;
778	int seqno = (*i)->seqno;	1000	int seqno = (*i)->seqno;
779	u8 data[MAXSIZE], *datap = data;	1001	u8 data[MAXSIZE], *datap = data;
780		1002
		1003	if ((*i)->retry)
		1004	{
		1005	dns->send_interval *= 1.01;
		1006	if (dns->send_interval > MAX_SEND_INTERVAL)
		1007	dns->send_interval = MAX_SEND_INTERVAL;
		1008	}
		1009	else
		1010	{
		1011	#if 1
		1012	dns->send_interval *= 0.999;
		1013	#endif
		1014	if (dns->send_interval < MIN_SEND_INTERVAL)
		1015	dns->send_interval = MIN_SEND_INTERVAL;
		1016
		1017	// the latency surely puts an upper bound on
		1018	// the minimum send interval
		1019	double latency = NOW - (*i)->sent;
		1020	dns->last_latency = latency;
		1021
		1022	if (dns->send_interval > latency)
		1023	dns->send_interval = latency;
		1024	}
		1025
781	delete *i;	1026	delete *i;
782	dns_sndpq.erase (i);	1027	dns_sndpq.erase (i);
783		1028
784	if (flags & (FLAG_RESPONSE \| FLAG_OP_MASK \| FLAG_TC))	1029	if (flags & FLAG_RESPONSE && !(flags & FLAG_OP_MASK))
785	{	1030	{
786	char qname[MAXSIZE];	1031	char qname[MAXSIZE];
787		1032
788	while (pkt->qdcount-- && offs < MAXSIZE - 4)	1033	while (pkt.qdcount-- && offs < MAXSIZE - 4)
789	{	1034	{
790	int qlen = pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);	1035	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
791	offs += 4; // skip qtype, qclass	1036	offs += 4; // skip qtype, qclass
792	}	1037	}
793		1038
794	while (pkt->ancount-- && offs < MAXSIZE - 10)	1039	while (pkt.ancount-- && offs < MAXSIZE - 10 && datap)
795	{	1040	{
796	int qlen = //D
797	pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);	1041	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
798		1042
799	printf ("got reply to <%.*s>\n", qlen, qname);//D
800
801	u16 qtype = (pkt) [offs++] << 8; qtype \|= (pkt) [offs++];	1043	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];
802	u16 qclass = (pkt) [offs++] << 8; qclass \|= (pkt) [offs++];	1044	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];
803	u32 ttl = (*pkt) [offs++] << 24;	1045	u32 ttl = pkt [offs++] << 24;
804	ttl \|= (*pkt) [offs++] << 16;	1046	ttl \|= pkt [offs++] << 16;
805	ttl \|= (*pkt) [offs++] << 8;	1047	ttl \|= pkt [offs++] << 8;
806	ttl \|= (*pkt) [offs++];	1048	ttl \|= pkt [offs++];
807
808	u16 rdlen = (pkt) [offs++] << 8; rdlen \|= (pkt) [offs++];	1049	u16 rdlen = pkt [offs++] << 8; rdlen \|= pkt [offs++];
809		1050
810	if (rdlen <= MAXSIZE - offs)	1051	if (qtype == RR_TYPE_NULL \|\| qtype == RR_TYPE_TXT)
811	{	1052	{
812	// decode bytes, finally	1053	if (rdlen <= MAXSIZE - offs)
813
814	while (rdlen)
815	{	1054	{
		1055	// decode bytes, finally
		1056
		1057	while (rdlen)
		1058	{
816	int txtlen = (*pkt) [offs++];	1059	int txtlen = pkt [offs++];
817		1060
818	assert (txtlen + offs < MAXSIZE - 1);	1061	assert (txtlen + offs < MAXSIZE - 1);
819		1062
820	memcpy (datap, pkt->at (offs), txtlen);	1063	memcpy (datap, pkt.at (offs), txtlen);
821	datap += txtlen; offs += txtlen;	1064	datap += txtlen; offs += txtlen;
822		1065
823	rdlen -= txtlen + 1;	1066	rdlen -= txtlen + 1;
		1067	}
824	}	1068	}
825
826	}	1069	}
		1070	else if (qtype == RR_TYPE_A)
		1071	{
		1072	u8 ip [4];
827		1073
		1074	ip [0] = pkt [offs++];
		1075	ip [1] = pkt [offs++];
		1076	ip [2] = pkt [offs++];
		1077	ip [3] = pkt [offs++];
		1078
		1079	if (ip [0] == CMD_IP_1
		1080	&& ip [1] == CMD_IP_2
		1081	&& ip [2] == CMD_IP_3)
		1082	{
		1083	slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]);
		1084
		1085	if (ip [3] == CMD_IP_RST)
		1086	{
		1087	slog (L_DEBUG, _("DNS: got tunnel RST request"));
		1088
		1089	delete dns; c->dns = 0;
		1090
		1091	return;
		1092	}
		1093	else if (ip [3] == CMD_IP_SYN)
		1094	{
		1095	slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us."));
		1096	dns->established = true;
		1097	}
		1098	else if (ip [3] == CMD_IP_REJ)
		1099	{
		1100	slog (L_DEBUG, _("DNS: got tunnel REJ reply, server does not like us, aborting."));
		1101	abort ();
		1102	}
		1103	else
		1104	slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]);
		1105	}
		1106	else
		1107	slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"),
		1108	ip [0], ip [1], ip [2], ip [3]);
		1109
		1110	return;
		1111	}
		1112
		1113	int client, rseqno;
		1114	decode_header (qname, client, rseqno);
		1115
		1116	if (client != THISNODE->id)
		1117	{
		1118	slog (L_INFO, _("DNS: got dns tunnel response with wrong clientid, ignoring"));
		1119	datap = 0;
		1120	}
		1121	else if (rseqno != seqno)
		1122	{
		1123	slog (L_DEBUG, _("DNS: got dns tunnel response with wrong seqno, badly caching nameserver?"));
		1124	datap = 0;
		1125	}
828	}	1126	}
829	}	1127	}
830		1128
831	// todo: pkt now used	1129	// todo: pkt now used
		1130	if (datap)
832	c->dnsv4_receive_rep (new dns_rcv (seqno, data, datap - data));	1131	dns->receive_rep (new dns_rcv (seqno, data, datap - data));
833		1132
834	break;	1133	break;
835	}	1134	}
836
837	delete pkt;
838	}	1135	}
839		1136
840	void	1137	void
841	vpn::dnsv4_ev (io_watcher &w, short revents)	1138	vpn::dnsv4_ev (io_watcher &w, short revents)
842	{	1139	{
…		…
844	{	1141	{
845	dns_packet *pkt = new dns_packet;	1142	dns_packet *pkt = new dns_packet;
846	struct sockaddr_in sa;	1143	struct sockaddr_in sa;
847	socklen_t sa_len = sizeof (sa);	1144	socklen_t sa_len = sizeof (sa);
848		1145
849	pkt->len = recvfrom (w.fd, &((pkt)[0]), MAXSIZE, 0, (sockaddr )&sa, &sa_len);	1146	pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
850		1147
851	if (pkt->len > 0)	1148	if (pkt->len > 0)
852	{	1149	{
853	if (pkt->flags & htons (FLAG_TC))
854	{
855	slog (L_WARN, _("DNS request/response truncated, check protocol settings."));
856	//TODO connection reset
857	}
858
859	if (THISNODE->dns_port)	1150	if (THISNODE->dns_port)
860	{	1151	{
861	pkt = dnsv4_server (pkt);	1152	dnsv4_server (*pkt);
862	sendto (w.fd, &((pkt)[0]), pkt->len, 0, (sockaddr )&sa, sa_len);	1153	sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);
863	}	1154	}
864	else	1155	else
865	dnsv4_client (pkt);	1156	dnsv4_client (*pkt);
		1157
		1158	delete pkt;
866	}	1159	}
867	}	1160	}
868	}	1161	}
869		1162
870	bool	1163	bool
871	connection::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)	1164	vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
872	{	1165	{
873	// never initialized	1166	int client = ntohs (si.port);
874	if (!dns_snddq && !dns_rcvdq)
875	{
876	dns_rcvdq = new byte_stream (MAX_BACKLOG * 2);
877	dns_snddq = new byte_stream (MAX_BACKLOG);
878		1167
879	//dns_rcvseq = dns_sndseq = 0;	1168	assert (0 < client && client <= conns.size ());
880		1169
881	dns_si.set (::conf.dns_forw_host, ::conf.dns_forw_port, PROT_DNSv4);	1170	connection *c = conns [client - 1];
882	}	1171
		1172	if (!c->dns)
		1173	c->dns = new dns_connection (c);
883		1174
884	if (!dns_snddq->put (pkt))	1175	if (!c->dns->snddq.put (pkt))
885	return false;	1176	return false;
886		1177
887	// start timer if neccessary	1178	c->dns->tw.trigger ();
888	if (!THISNODE->dns_port && !dnsv4_tw.active)
889	dnsv4_cb (dnsv4_tw);
890		1179
891	return true;	1180	return true;
892	}	1181	}
893		1182
894	void	1183	void
		1184	connection::dnsv4_reset_connection ()
		1185	{
		1186	//delete dns; dns = 0; //TODO
		1187	}
		1188
		1189	#define NEXT(w) do { if (next > (w)) next = w; } while (0)
		1190
		1191	void
895	connection::dnsv4_cb (time_watcher &w)	1192	dns_connection::time_cb (time_watcher &w)
896	{	1193	{
		1194	// servers have to be polled
		1195	if (THISNODE->dns_port)
		1196	return;
		1197
897	// check for timeouts and (re)transmit	1198	// check for timeouts and (re)transmit
898	tstamp next = NOW + 60;	1199	tstamp next = NOW + poll_interval;
899	dns_req *send = 0;	1200	dns_snd *send = 0;
900		1201
901	for (vector<dns_req *>::iterator i = vpn->dns_sndpq.begin ();	1202	for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
902	i != vpn->dns_sndpq.end ();	1203	i != vpn->dns_sndpq.end ();
903	++i)	1204	++i)
904	{	1205	{
905	dns_req r = i;	1206	dns_snd r = i;
906		1207
907	if (r->next <= NOW)	1208	if (r->timeout <= NOW)
908	{	1209	{
909	if (!send)	1210	if (!send)
910	{	1211	{
911	send = r;	1212	send = r;
912		1213
913	if (r->retry)//D
914	printf ("req %d:%d, retry %d\n", r->seqno, r->pkt->id, r->retry);
915	r->retry++;	1214	r->retry++;
916	r->next = NOW + r->retry;	1215	r->timeout = NOW + (r->retry * last_latency * 8.);
		1216
		1217	// the following code changes the query section a bit, forcing
		1218	// the forwarder to generate a new request
		1219	if (r->stdhdr)
		1220	{
		1221	//printf ("reencoded header for ID %d retry %d:%d:%d\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry);printf ("reencoded header for ID %d retry %d:%d:%d\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry);
		1222	//encode_header ((char )r->pkt->at (6 2 + 1), THISNODE->id, r->seqno, r->retry);
		1223	}
917	}	1224	}
918	}	1225	}
		1226	else
		1227	NEXT (r->timeout);
		1228	}
919		1229
920	if (r->next < next)	1230	if (last_sent + send_interval <= NOW)
921	next = r->next;
922	}	1231	{
923
924	if (!send	1232	if (!send)
		1233	{
		1234	// generate a new packet, if wise
		1235
		1236	if (!established)
		1237	{
		1238	if (vpn->dns_sndpq.empty ())
		1239	{
		1240	send = new dns_snd (this);
		1241
		1242	printf ("new conn %p %d\n", this, c->conf->id);//D
		1243	cfg.reset (THISNODE->id);
		1244	send->gen_syn_req ();
		1245	}
		1246	}
925	&& vpn->dns_sndpq.size () < MAX_OUTSTANDING)	1247	else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING
926	{	1248	&& !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
		1249	{
		1250	//printf ("sending data request etc.\n"); //D
		1251	if (!snddq.empty ())
		1252	{
		1253	poll_interval = send_interval;
		1254	NEXT (NOW + send_interval);
		1255	}
		1256
927	send = new dns_req (this);	1257	send = new dns_snd (this);
928	send->gen_stream_req (dns_sndseq, dns_snddq);	1258	send->gen_stream_req (sndseq, snddq);
		1259	send->timeout = NOW + last_latency * 8.;
		1260
		1261	sndseq = (sndseq + 1) & SEQNO_MASK;
		1262	}
		1263
		1264	if (send)
929	vpn->dns_sndpq.push_back (send);	1265	vpn->dns_sndpq.push_back (send);
		1266	}
930		1267
931	dns_sndseq = (dns_sndseq + 1) & SEQNO_MASK;
932	}
933
934	tstamp min_next = NOW + (1. / (tstamp)MAX_RATE);
935
936	if (send)	1268	if (send)
		1269	{
		1270	last_sent = NOW;
		1271	sendto (vpn->dnsv4_fd,
		1272	send->pkt->at (0), send->pkt->len, 0,
		1273	vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
		1274	}
937	{	1275	}
938	dns_packet *pkt = send->pkt;	1276	else
		1277	NEXT (last_sent + send_interval);
939		1278
940	next = min_next;	1279	slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d)",
		1280	poll_interval, send_interval, next - NOW,
		1281	vpn->dns_sndpq.size (), snddq.size ());
941		1282
942	sendto (vpn->dnsv4_fd, &((*pkt)[0]), pkt->len, 0, dns_si.sav4 (), dns_si.salenv4 ());	1283	// TODO: no idea when this happens, but when next < NOW, we have a problem
943	}	1284	if (next < NOW + 0.0001)
944	else if (next < min_next)	1285	next = NOW + 0.1;
945	next = min_next;
946		1286
947	w.start (next);	1287	w.start (next);
948	}	1288	}
949		1289
950	#endif	1290	#endif

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Comparing gvpe/src/vpn_dns.C (file contents): Revision 1.8 by pcg, Fri Mar 4 03:43:09 2005 UTC vs. Revision 1.18 by pcg, Sat Mar 5 19:13:16 2005 UTC

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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.8 by pcg, Fri Mar 4 03:43:09 2005 UTC vs.
Revision 1.18 by pcg, Sat Mar 5 19:13:16 2005 UTC