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

Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.9 by pcg, Fri Mar 4 04:52:38 2005 UTC vs.
Revision 1.37 by pcg, Wed Mar 23 17:03:58 2005 UTC

…		…
25		25
26	// dns processing is EXTREMELY ugly. For obvious(?) reasons.	26	// dns processing is EXTREMELY ugly. For obvious(?) reasons.
27	// it's a hack, use only in emergency situations please.	27	// it's a hack, use only in emergency situations please.
28		28
29	#include <cstring>	29	#include <cstring>
		30	#include <cassert>
30		31
31	#include <sys/types.h>	32	#include <sys/types.h>
32	#include <sys/socket.h>	33	#include <sys/socket.h>
33	#include <sys/wait.h>	34	#include <sys/wait.h>
34	#include <sys/uio.h>	35	#include <sys/uio.h>
…		…
43		44
44	#include "netcompat.h"	45	#include "netcompat.h"
45		46
46	#include "vpn.h"	47	#include "vpn.h"
47		48
48	#define MIN_RETRY 1.	49	#define MAX_POLL_INTERVAL 5. // how often to poll minimally when the server has no data
49	#define MAX_RETRY 6.	50	#define ACTIVITY_INTERVAL 5.
50		51
51	#define MAX_OUTSTANDING 400 // max. outstanding requests	52	#define INITIAL_TIMEOUT 0.1 // retry timeouts
		53	#define INITIAL_SYN_TIMEOUT 2. // retry timeout for initial syn
		54
		55	#define MAX_SEND_INTERVAL 2. // optimistic?
		56
52	#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING	57	#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog
53	#define MAX_RATE 100 // requests/s
54	#define MAX_BACKLOG (10*1024) // size of protocol backlog, must be > MAXSIZE	58	#define MAX_BACKLOG (64*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
55		59
56	#define MAX_DOMAIN_SIZE 220 // 255 is legal limit, but bind doesn't compress well	60	#define MAX_DOMAIN_SIZE 240 // 255 is legal limit, but bind doesn't compress well
57	// 240 leaves about 4 bytes of server reply data	61	// 240 leaves about 4 bytes of server reply data
58	// every two request byte sless give room for one reply byte	62	// every request byte less give room for two reply bytes
59		63
60	#define SEQNO_MASK 0xffff	64	#define SEQNO_MASK 0x3fff
61	#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )	65	#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
62		66
63	#define MAX_LBL_SIZE 63	67	#define MAX_LBL_SIZE 63
64	#define MAX_PKT_SIZE 512	68	#define MAX_PKT_SIZE 512
65		69
		70	#define RR_TYPE_A 1
		71	#define RR_TYPE_NULL 10
66	#define RR_TYPE_TXT 16	72	#define RR_TYPE_TXT 16
67	#define RR_TYPE_ANY 255	73	#define RR_TYPE_ANY 255
		74
68	#define RR_CLASS_IN 1	75	#define RR_CLASS_IN 1
		76
		77	#define CMD_IP_1 207
		78	#define CMD_IP_2 46
		79	#define CMD_IP_3 236
		80	#define CMD_IP_RST 29
		81	#define CMD_IP_SYN 113
		82	#define CMD_IP_REJ 32
69		83
70	// works for cmaps up to 255 (not 256!)	84	// works for cmaps up to 255 (not 256!)
71	struct charmap	85	struct charmap
72	{	86	{
73	enum { INVALID = (u8)255 };	87	enum { INVALID = (u8)255 };
…		…
153	return dec_len [len];	167	return dec_len [len];
154	}	168	}
155		169
156	unsigned int basecoder::encode (char dst, u8 src, unsigned int len)	170	unsigned int basecoder::encode (char dst, u8 src, unsigned int len)
157	{	171	{
158	if (!len)	172	if (!len \|\| len > MAX_DEC_LEN)
159	return 0;	173	return 0;
160		174
161	int elen = encode_len (len);	175	int elen = encode_len (len);
162		176
163	mp_limb_t m [MAX_LIMBS];	177	mp_limb_t m [MAX_LIMBS];
…		…
182	return elen;	196	return elen;
183	}	197	}
184		198
185	unsigned int basecoder::decode (u8 dst, char src, unsigned int len)	199	unsigned int basecoder::decode (u8 dst, char src, unsigned int len)
186	{	200	{
187	if (!len)	201	if (!len \|\| len > MAX_ENC_LEN)
188	return 0;	202	return 0;
189		203
190	u8 src_ [MAX_ENC_LEN];	204	u8 src_ [MAX_ENC_LEN];
191	unsigned int elen = 0;	205	unsigned int elen = 0;
192		206
…		…
239	}	253	}
240	abort ();	254	abort ();
241	}	255	}
242	#endif	256	#endif
243		257
244	// the following sequence has been crafted to	258	//static basecoder cdc64 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI-");
245	// a) look somewhat random
246	// b) the even (and odd) indices never share the same character as upper/lowercase
247	// the "_" is not valid but widely accepted (all octets should be supported, but let's be conservative)
248	// the other sequences are obviously derived
249	//static basecoder cdc63 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");	259	//static basecoder cdc63 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");
250	static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");	260	static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");
251	//static basecoder cdc36 ("dphzr06qmjkb34tsvl81xaef92wgyo57ucni"); // unused as of yet	261	//static basecoder cdc36 ("dphzr06qmjkb34tsvl81xaef92wgyo57ucni"); // unused as of yet
252	static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");	262	static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");
253		263
254	/////////////////////////////////////////////////////////////////////////////	264	/////////////////////////////////////////////////////////////////////////////
255		265
256	#define HDRSIZE 6	266	#define HDRSIZE 6
257		267
258	inline void encode_header (char *data, int clientid, int seqno)	268	inline void encode_header (char *data, int clientid, int seqno, int retry = 0)
259	{	269	{
260	u8 hdr[3] = { clientid, seqno >> 8, seqno };	270	seqno &= SEQNO_MASK;
		271
		272	u8 hdr[3] = {
		273	clientid,
		274	(seqno >> 8) \| (retry << 6),
		275	seqno,
		276	};
261		277
262	assert (clientid < 256);	278	assert (clientid < 256);
263		279
264	cdc26.encode (data, hdr, 3);	280	cdc26.encode (data, hdr, 3);
265	}	281	}
…		…
269	u8 hdr[3];	285	u8 hdr[3];
270		286
271	cdc26.decode (hdr, data, HDRSIZE);	287	cdc26.decode (hdr, data, HDRSIZE);
272		288
273	clientid = hdr[0];	289	clientid = hdr[0];
274	seqno = (hdr[1] << 8) \| hdr[2];	290	seqno = ((hdr[1] << 8) \| hdr[2]) & SEQNO_MASK;
275	}	291	}
276		292
277	/////////////////////////////////////////////////////////////////////////////	293	/////////////////////////////////////////////////////////////////////////////
278		294
279	struct byte_stream	295	struct byte_stream
…		…
308	}	324	}
309		325
310	void byte_stream::remove (int count)	326	void byte_stream::remove (int count)
311	{	327	{
312	if (count > fill)	328	if (count > fill)
313	abort ();	329	assert (count <= fill);
314		330
315	memmove (data, data + count, fill -= count);	331	memmove (data, data + count, fill -= count);
316	}	332	}
317		333
318	bool byte_stream::put (u8 *data, unsigned int datalen)	334	bool byte_stream::put (u8 *data, unsigned int datalen)
…		…
331	return false;	347	return false;
332		348
333	data [fill++] = pkt->len >> 8;	349	data [fill++] = pkt->len >> 8;
334	data [fill++] = pkt->len;	350	data [fill++] = pkt->len;
335		351
336	memcpy (data + fill, &((*pkt)[0]), pkt->len); fill += pkt->len;	352	memcpy (data + fill, pkt->at (0), pkt->len); fill += pkt->len;
337		353
338	return true;	354	return true;
339	}	355	}
340		356
341	vpn_packet *byte_stream::get ()	357	vpn_packet *byte_stream::get ()
342	{	358	{
		359	unsigned int len;
		360
		361	for (;;)
		362	{
343	int len = (data [0] << 8) \| data [1];	363	len = (data [0] << 8) \| data [1];
344		364
345	if (len > MAXSIZE && fill >= 2)	365	if (len <= MAXSIZE \|\| fill < 2)
346	abort (); // TODO handle this gracefully, connection reset	366	break;
347		367
		368	// TODO: handle this better than skipping, e.g. by reset
		369	slog (L_DEBUG, _("DNS: corrupted packet stream skipping a byte..."));
		370	remove (1);
		371	}
		372
348	if (fill < len + 2)	373	if (fill < len + 2)
349	return 0;	374	return 0;
350		375
351	vpn_packet *pkt = new vpn_packet;	376	vpn_packet *pkt = new vpn_packet;
352		377
353	pkt->len = len;	378	pkt->len = len;
354	memcpy (&((*pkt)[0]), data + 2, len);	379	memcpy (pkt->at (0), data + 2, len);
355	remove (len + 2);	380	remove (len + 2);
356		381
357	return pkt;	382	return pkt;
358	}	383	}
359		384
…		…
376	#define FLAG_RCODE_REFUSED ( 5 << 0)	401	#define FLAG_RCODE_REFUSED ( 5 << 0)
377		402
378	#define DEFAULT_CLIENT_FLAGS (FLAG_QUERY \| FLAG_OP_QUERY \| FLAG_RD)	403	#define DEFAULT_CLIENT_FLAGS (FLAG_QUERY \| FLAG_OP_QUERY \| FLAG_RD)
379	#define DEFAULT_SERVER_FLAGS (FLAG_RESPONSE \| FLAG_OP_QUERY \| FLAG_AA \| FLAG_RD \| FLAG_RA)	404	#define DEFAULT_SERVER_FLAGS (FLAG_RESPONSE \| FLAG_OP_QUERY \| FLAG_AA \| FLAG_RD \| FLAG_RA)
380		405
		406	struct dns_cfg
		407	{
		408	static int next_uid;
		409
		410	u8 id1, id2, id3, id4;
		411
		412	u8 version;
		413	u8 flags;
		414	u8 rrtype;
		415	u8 def_ttl;
		416
		417	u16 client;
		418	u16 uid; // to make request unique
		419
		420	u16 max_size;
		421	u8 seq_cdc;
		422	u8 req_cdc;
		423
		424	u8 rep_cdc;
		425	u8 delay; // time in 0.01s units that the server may delay replying packets
		426	u8 r3, r4;
		427
		428	u8 r5, r6, r7, r8;
		429
		430	void reset (int clientid);
		431	bool valid ();
		432	};
		433
		434	int dns_cfg::next_uid;
		435
		436	void dns_cfg::reset (int clientid)
		437	{
		438	id1 = 'G';
		439	id2 = 'V';
		440	id3 = 'P';
		441	id4 = 'E';
		442
		443	version = 1;
		444
		445	rrtype = RR_TYPE_TXT;
		446	flags = 0;
		447	def_ttl = 0;
		448	seq_cdc = 26;
		449	req_cdc = 62;
		450	rep_cdc = 0;
		451	max_size = htons (MAX_PKT_SIZE);
		452	client = htons (clientid);
		453	uid = next_uid++;
		454	delay = 0;
		455
		456	r3 = r4 = 0;
		457	r4 = r5 = r6 = r7 = 0;
		458	}
		459
		460	bool dns_cfg::valid ()
		461	{
		462	return id1 == 'G'
		463	&& id2 == 'V'
		464	&& id3 == 'P'
		465	&& id4 == 'E'
		466	&& seq_cdc == 26
		467	&& req_cdc == 62
		468	&& rep_cdc == 0
		469	&& version == 1;
		470	}
		471
381	struct dns_packet : net_packet	472	struct dns_packet : net_packet
382	{	473	{
383	u16 id;	474	u16 id;
384	u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4	475	u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4
385	u16 qdcount, ancount, nscount, arcount;	476	u16 qdcount, ancount, nscount, arcount;
386		477
387	u8 data[MAXSIZE - 6 * 2];	478	u8 data [MAXSIZE - 6 * 2];
388		479
389	int decode_label (char *data, int size, int &offs);	480	int decode_label (char *data, int size, int &offs);
390	};	481	};
391		482
392	int dns_packet::decode_label (char *data, int size, int &offs)	483	int dns_packet::decode_label (char *data, int size, int &offs)
…		…
423	return data - orig;	514	return data - orig;
424	}	515	}
425		516
426	/////////////////////////////////////////////////////////////////////////////	517	/////////////////////////////////////////////////////////////////////////////
427		518
428	struct dns_req
429	{
430	dns_packet *pkt;
431	tstamp next;
432	int retry;
433	struct dns_connection *dns;
434	int seqno;
435
436	dns_req (dns_connection *dns);
437	void gen_stream_req (int seqno, byte_stream &stream);
438	};
439
440	static u16 dns_id = 12098; // TODO: should be per-vpn	519	static u16 dns_id = 0; // TODO: should be per-vpn
441		520
442	static u16 next_id ()	521	static u16 next_id ()
443	{	522	{
		523	if (!dns_id)
		524	dns_id = time (0);
		525
444	// the simplest lsfr with periodicity 65535 i could find	526	// the simplest lsfr with periodicity 65535 i could find
445	dns_id = (dns_id << 1)	527	dns_id = (dns_id << 1)
446	\| (((dns_id >> 1)	528	\| (((dns_id >> 1)
447	^ (dns_id >> 2)	529	^ (dns_id >> 2)
448	^ (dns_id >> 4)	530	^ (dns_id >> 4)
449	^ (dns_id >> 15)) & 1);	531	^ (dns_id >> 15)) & 1);
450		532
451	return dns_id;	533	return dns_id;
452	}	534	}
453		535
		536	struct dns_rcv;
		537	struct dns_snd;
		538
		539	struct dns_connection
		540	{
		541	connection *c;
		542	struct vpn *vpn;
		543
		544	dns_cfg cfg;
		545
		546	bool established;
		547
		548	tstamp last_received;
		549	tstamp last_sent;
		550	double min_latency;
		551	double poll_interval, send_interval;
		552
		553	vector<dns_rcv *> rcvpq;
		554
		555	byte_stream rcvdq; int rcvseq; int repseq;
		556	byte_stream snddq; int sndseq;
		557
		558	void time_cb (time_watcher &w); time_watcher tw;
		559	void receive_rep (dns_rcv *r);
		560
		561	dns_connection (connection *c);
		562	~dns_connection ();
		563	};
		564
		565	struct dns_snd
		566	{
		567	dns_packet *pkt;
		568	tstamp timeout, sent;
		569	int retry;
		570	struct dns_connection *dns;
		571	int seqno;
		572	bool stdhdr;
		573
		574	void gen_stream_req (int seqno, byte_stream &stream);
		575	void gen_syn_req ();
		576
		577	dns_snd (dns_connection *dns);
		578	~dns_snd ();
		579	};
		580
454	dns_req::dns_req (dns_connection *dns)	581	dns_snd::dns_snd (dns_connection *dns)
455	: dns (dns)	582	: dns (dns)
456	{	583	{
457	next = 0;	584	timeout = 0;
458	retry = 0;	585	retry = 0;
		586	seqno = 0;
		587	sent = NOW;
		588	stdhdr = false;
459		589
460	pkt = new dns_packet;	590	pkt = new dns_packet;
461		591
462	pkt->id = next_id ();	592	pkt->id = next_id ();
463	}	593	}
464		594
		595	dns_snd::~dns_snd ()
		596	{
		597	delete pkt;
		598	}
		599
		600	static void append_domain (dns_packet &pkt, int &offs, const char *domain)
		601	{
		602	// add tunnel domain
		603	for (;;)
		604	{
		605	const char *end = strchr (domain, '.');
		606
		607	if (!end)
		608	end = domain + strlen (domain);
		609
		610	int len = end - domain;
		611
		612	pkt [offs++] = len;
		613	memcpy (pkt.at (offs), domain, len);
		614	offs += len;
		615
		616	if (!*end)
		617	break;
		618
		619	domain = end + 1;
		620	}
		621	}
		622
465	void dns_req::gen_stream_req (int seqno, byte_stream &stream)	623	void dns_snd::gen_stream_req (int seqno, byte_stream &stream)
466	{	624	{
		625	stdhdr = true;
467	this->seqno = seqno;	626	this->seqno = seqno;
		627
		628	timeout = NOW + INITIAL_TIMEOUT;
468		629
469	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);	630	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
470	pkt->qdcount = htons (1);	631	pkt->qdcount = htons (1);
471		632
472	int offs = 6*2;	633	int offs = 6*2;
473	int dlen = MAX_DOMAIN_SIZE - (strlen (THISNODE->domain) + 2);	634	int dlen = MAX_DOMAIN_SIZE - (strlen (dns->c->conf->domain) + 2);
474	// MAX_DOMAIN_SIZE is technically 255, but bind doesn't compress responses well,	635	// MAX_DOMAIN_SIZE is technically 255, but bind doesn't compress responses well,
475	// so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra	636	// so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra
476		637
477	char enc[256], *encp = enc;	638	char enc[256], *encp = enc;
478	encode_header (enc, THISNODE->id, seqno);	639	encode_header (enc, THISNODE->id, seqno);
…		…
496	encp += lbllen;	657	encp += lbllen;
497		658
498	enclen -= lbllen;	659	enclen -= lbllen;
499	}	660	}
500		661
501	const char *suffix = THISNODE->domain;	662	append_domain (*pkt, offs, dns->c->conf->domain);
502
503	// add tunnel domain
504	for (;;)
505	{
506	const char *end = strchr (suffix, '.');
507
508	if (!end)
509	end = suffix + strlen (suffix);
510
511	int len = end - suffix;
512
513	(*pkt)[offs++] = len;
514	memcpy (&((*pkt)[offs]), suffix, len);
515	offs += len;
516
517	if (!*end)
518	break;
519
520	suffix = end + 1;
521	}
522		663
523	(*pkt)[offs++] = 0;	664	(*pkt)[offs++] = 0;
524	(pkt)[offs++] = RR_TYPE_ANY >> 8; (pkt)[offs++] = RR_TYPE_ANY;	665	(pkt)[offs++] = RR_TYPE_ANY >> 8; (pkt)[offs++] = RR_TYPE_ANY;
		666	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;
		667
		668	pkt->len = offs;
		669	}
		670
		671	void dns_snd::gen_syn_req ()
		672	{
		673	timeout = NOW + INITIAL_SYN_TIMEOUT;
		674
		675	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
		676	pkt->qdcount = htons (1);
		677
		678	int offs = 6 * 2;
		679
		680	int elen = cdc26.encode ((char )pkt->at (offs + 1), (u8 )&dns->cfg, sizeof (dns_cfg));
		681
		682	assert (elen <= MAX_LBL_SIZE);
		683
		684	(*pkt)[offs] = elen;
		685	offs += elen + 1;
		686	append_domain (*pkt, offs, dns->c->conf->domain);
		687
		688	(*pkt)[offs++] = 0;
		689	(pkt)[offs++] = RR_TYPE_A >> 8; (pkt)[offs++] = RR_TYPE_A;
525	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;	690	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;
526		691
527	pkt->len = offs;	692	pkt->len = offs;
528	}	693	}
529		694
…		…
549	delete pkt;	714	delete pkt;
550	}	715	}
551		716
552	/////////////////////////////////////////////////////////////////////////////	717	/////////////////////////////////////////////////////////////////////////////
553		718
554	struct dns_connection
555	{
556	connection *c;
557	struct vpn *vpn;
558
559	vector<dns_rcv *> rcvpq;
560
561	int rcvseq;
562	int sndseq;
563
564	byte_stream rcvdq;
565	byte_stream snddq;
566
567	void time_cb (time_watcher &w); time_watcher tw;
568	void receive_rep (dns_rcv *r);
569
570	dns_connection (connection *c);
571	~dns_connection ();
572	};
573
574	dns_connection::dns_connection (connection *c)	719	dns_connection::dns_connection (connection *c)
575	: c (c)	720	: c (c)
576	, rcvdq (MAX_BACKLOG * 2)	721	, rcvdq (MAX_BACKLOG * 2)
577	, snddq (MAX_BACKLOG * 2)	722	, snddq (MAX_BACKLOG)
578	, tw (this, &dns_connection::time_cb)	723	, tw (this, &dns_connection::time_cb)
579	{	724	{
580	vpn = c->vpn;	725	vpn = c->vpn;
581		726
		727	established = false;
		728
582	rcvseq = sndseq = 0;	729	rcvseq = repseq = sndseq = 0;
		730
		731	last_sent = last_received = 0;
		732	poll_interval = 0.5; // starting here
		733	send_interval = 0.5; // starting rate
		734	min_latency = INITIAL_TIMEOUT;
583	}	735	}
584		736
585	dns_connection::~dns_connection ()	737	dns_connection::~dns_connection ()
586	{	738	{
587	for (vector<dns_rcv *>::iterator i = rcvpq.begin ();	739	for (vector<dns_rcv *>::iterator i = rcvpq.begin ();
588	i != rcvpq.end ();	740	i != rcvpq.end ();
589	++i)	741	++i)
590	delete *i;	742	delete *i;
591	}	743	}
592		744
593	struct dns_cfg
594	{
595	u8 id1, id2, id3;
596	u8 def_ttl;
597	u8 unused1;
598	u16 max_size;
599	u8 flags1, flags2;
600	};
601
602	void dns_connection::receive_rep (dns_rcv *r)	745	void dns_connection::receive_rep (dns_rcv *r)
603	{	746	{
		747	if (r->datalen)
		748	{
		749	last_received = NOW;
		750	tw.trigger ();
		751
		752	poll_interval = send_interval;
		753	}
		754	else
		755	{
		756	poll_interval *= 1.5;
		757
		758	if (poll_interval > MAX_POLL_INTERVAL)
		759	poll_interval = MAX_POLL_INTERVAL;
		760	}
		761
604	rcvpq.push_back (r);	762	rcvpq.push_back (r);
605		763
606	redo:	764	redo:
607		765
608	// find next packet	766	// find next packet
…		…
622	}	780	}
623		781
624	rcvseq = (rcvseq + 1) & SEQNO_MASK;	782	rcvseq = (rcvseq + 1) & SEQNO_MASK;
625		783
626	if (!rcvdq.put (r->data, r->datalen))	784	if (!rcvdq.put (r->data, r->datalen))
		785	{
		786	slog (L_ERR, "DNS: !rcvdq.put (r->data, r->datalen)");
627	abort (); // MUST never overflow, can be caused by data corruption, TODO	787	abort (); // MUST never overflow, can be caused by data corruption, TODO
		788	}
628		789
629	while (vpn_packet *pkt = rcvdq.get ())	790	while (vpn_packet *pkt = rcvdq.get ())
630	{	791	{
631	sockinfo si;	792	sockinfo si;
632	si.host = 0; si.port = 0; si.prot = PROT_DNSv4;	793	si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4;
633		794
634	vpn->recv_vpn_packet (pkt, si);	795	vpn->recv_vpn_packet (pkt, si);
		796
		797	delete pkt;
635	}	798	}
636		799
637	// check for further packets	800	// check for further packets
638	goto redo;	801	goto redo;
639	}	802	}
640	}	803	}
641		804
642	dns_packet *	805	void
643	vpn::dnsv4_server (dns_packet *pkt)	806	vpn::dnsv4_server (dns_packet &pkt)
644	{	807	{
645	u16 flags = ntohs (pkt->flags);	808	u16 flags = ntohs (pkt.flags);
646		809
647	//memcpy (&((rep)[0]), &((pkt)[0]), pkt->len);
648	int offs = 6 * 2; // skip header	810	int offs = 6 * 2; // skip header
649		811
650	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);	812	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
651		813
652	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK \| FLAG_TC))	814	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK))
653	&& pkt->qdcount == htons (1))	815	&& pkt.qdcount == htons (1))
654	{	816	{
655	char qname[MAXSIZE];	817	char qname [MAXSIZE];
656	int qlen = pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);	818	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
657		819
658	u16 qtype = (pkt) [offs++] << 8; qtype \|= (pkt) [offs++];	820	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];
659	u16 qclass = (pkt) [offs++] << 8; qclass \|= (pkt) [offs++];	821	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];
660		822
661	pkt->qdcount = htons (1);	823	pkt.qdcount = htons (1);
662	pkt->ancount = 0;	824	pkt.ancount = 0;
663	pkt->nscount = 0; // should be self, as other nameservers reply like this	825	pkt.nscount = 0; // should be self, as other nameservers reply like this
664	pkt->arcount = 0; // a record for self, as other nameservers reply like this	826	pkt.arcount = 0; // a record for self, as other nameservers reply like this
665		827
666	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_NXDOMAIN);	828	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_SERVFAIL);
667		829
668	int dlen = strlen (THISNODE->domain);	830	int dlen = strlen (THISNODE->domain);
669		831
670	if (qclass == RR_CLASS_IN	832	if (qclass == RR_CLASS_IN
671	&& (qtype == RR_TYPE_ANY \|\| qtype == RR_TYPE_TXT)
672	&& qlen > dlen + 1 + HDRSIZE	833	&& qlen > dlen + 1
673	&& !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen))	834	&& !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen))
674	{	835	{
675	// correct class, domain: parse	836	// now generate reply
676	int client, seqno;	837	pkt.ancount = htons (1); // one answer RR
677	decode_header (qname, client, seqno);	838	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);
678		839
679	u8 data[MAXSIZE];	840	if ((qtype == RR_TYPE_ANY
680	int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));	841	\|\| qtype == RR_TYPE_TXT
681		842	\|\| qtype == RR_TYPE_NULL)
682	if (0 < client && client <= conns.size ())	843	&& qlen > dlen + 1 + HDRSIZE)
683	{	844	{
		845	// correct class, domain: parse
		846	int client, seqno;
		847	decode_header (qname, client, seqno);
		848
		849	u8 data[MAXSIZE];
		850	int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
		851
		852	if (0 < client && client <= conns.size ())
		853	{
684	connection *c = conns [client - 1];	854	connection *c = conns [client - 1];
685
686	if (!c->dns)
687	c->dns = new dns_connection (c);
688
689	dns_connection *dns = c->dns;	855	dns_connection *dns = c->dns;
		856	dns_rcv *rcv;
690		857
		858	if (dns)
		859	{
691	for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )	860	for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
692	if (SEQNO_EQ ((*i)->seqno, seqno))	861	if (SEQNO_EQ ((*i)->seqno, seqno))
		862	{
		863	// already seen that request: simply reply with the cached reply
		864	dns_rcv r = i;
		865
		866	slog (L_DEBUG, "DNS: duplicate packet received ID %d, SEQ %d", htons (r->pkt->id), seqno);
		867
		868	// refresh header & id, as the retry count could have changed
		869	memcpy (r->pkt->at (6 * 2 + 1), pkt.at (6 * 2 + 1), HDRSIZE);
		870	r->pkt->id = pkt.id;
		871
		872	memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
		873
		874	goto duplicate_request;
		875	}
		876
		877	// new packet, queue
		878	rcv = new dns_rcv (seqno, data, datalen);
		879	dns->receive_rep (rcv);
		880	}
		881
693	{	882	{
694	// already seen that request: simply reply with the cached reply	883	pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section
695	dns_rcv r = i;
696		884
697	printf ("DUPLICATE %d\n", htons (r->pkt->id));//D	885	int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;
		886	pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type
		887	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
		888	pkt [offs++] = 0; pkt [offs++] = 0;
		889	pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
698		890
699	memcpy (pkt->at (0), r->pkt->at (0), offs = r->pkt->len);	891	int rdlen_offs = offs += 2;
700	pkt->id = r->pkt->id;	892
701	goto duplicate_request;	893	if (dns)
		894	{
		895	int dlen = ntohs (dns->cfg.max_size) - offs;
		896
		897	// bind doesn't compress well, so reduce further by one label length
		898	dlen -= qlen;
		899
		900	// only put data into in-order sequence packets, if
		901	// we receive out-of-order packets we generate empty
		902	// replies
		903	//printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D
		904	if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW)
		905	{
		906	dns->repseq = seqno;
		907
		908	while (dlen > 1 && !dns->snddq.empty ())
		909	{
		910	int txtlen = dlen <= 255 ? dlen - 1 : 255;
		911
		912	if (txtlen > dns->snddq.size ())
		913	txtlen = dns->snddq.size ();
		914
		915	pkt[offs++] = txtlen;
		916	memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
		917	offs += txtlen;
		918	dns->snddq.remove (txtlen);
		919
		920	dlen -= txtlen + 1;
		921	}
		922	}
		923
		924	// avoid completely empty TXT rdata
		925	if (offs == rdlen_offs)
		926	pkt[offs++] = 0;
		927
		928	slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
		929	}
		930	else
		931	{
		932	// send RST
		933	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
		934	pkt [offs++] = CMD_IP_RST;
		935	}
		936
		937	int rdlen = offs - rdlen_offs;
		938
		939	pkt [rdlen_offs - 2] = rdlen >> 8;
		940	pkt [rdlen_offs - 1] = rdlen;
		941
		942	if (dns)
		943	{
		944	// now update dns_rcv copy
		945	rcv->pkt->len = offs;
		946	memcpy (rcv->pkt->at (0), pkt.at (0), offs);
		947	}
702	}	948	}
703		949
704	// new packet, queue	950	duplicate_request: ;
705	dns_rcv *rcv = new dns_rcv (seqno, data, datalen);	951	}
706	dns->receive_rep (rcv);	952	else
707
708	// now generate reply
709	pkt->ancount = htons (1); // one answer RR
710	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);	953	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
		954	}
		955	else if (qtype == RR_TYPE_A
		956	&& qlen > dlen + 1 + cdc26.encode_len (sizeof (dns_cfg)))
		957	{
		958	dns_cfg cfg;
		959	cdc26.decode ((u8 *)&cfg, qname, cdc26.encode_len (sizeof (dns_cfg)));
		960	int client = ntohs (cfg.client);
711		961
712	(*pkt) [offs++] = 0xc0;
713	(pkt) [offs++] = 6 2; // same as in query section	962	pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section
714		963
715	(pkt) [offs++] = RR_TYPE_TXT >> 8; (pkt) [offs++] = RR_TYPE_TXT;	964	pkt [offs++] = RR_TYPE_A >> 8; pkt [offs++] = RR_TYPE_A; // type
716	(pkt) [offs++] = RR_CLASS_IN >> 8; (pkt) [offs++] = RR_CLASS_IN;	965	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
717
718	(pkt) [offs++] = 0; (pkt) [offs++] = 0;	966	pkt [offs++] = 0; pkt [offs++] = 0;
719	(pkt) [offs++] = 0; (pkt) [offs++] = 0; // TTL	967	pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
		968	pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
720		969
721	int dlen = MAX_PKT_SIZE - offs - 2;	970	slog (L_INFO, _("DNS: client %d connects"), client);
722		971
723	// bind doesn't compress well, so reduce further by one label length	972	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
724	dlen -= qlen;	973	pkt [offs++] = CMD_IP_REJ;
725		974
726	int rdlen_offs = offs += 2;	975	if (0 < client && client <= conns.size ())
727
728	while (dlen > 1 && !dns->snddq.empty ())
729	{	976	{
730	int txtlen = dlen <= 255 ? dlen - 1 : 255;	977	connection *c = conns [client - 1];
731		978
732	if (txtlen > dns->snddq.size ())	979	if (cfg.valid ())
733	txtlen = dns->snddq.size ();	980	{
		981	pkt [offs - 1] = CMD_IP_SYN;
734		982
735	(*pkt)[offs++] = txtlen;	983	delete c->dns;
736	memcpy (pkt->at (offs), dns->snddq.begin (), txtlen);	984	c->dns = new dns_connection (c);
737	offs += txtlen;	985	c->dns->cfg = cfg;
738	dns->snddq.remove (txtlen);	986	}
739
740	dlen -= txtlen + 1;
741	}	987	}
742
743	// avoid empty TXT rdata
744	if (offs == rdlen_offs)
745	(*pkt)[offs++] = 0;
746
747	int rdlen = offs - rdlen_offs;
748
749	(*pkt) [rdlen_offs - 2] = rdlen >> 8;
750	(*pkt) [rdlen_offs - 1] = rdlen;
751
752	// now update dns_rcv copy
753	rcv->pkt->len = offs;
754	memcpy (rcv->pkt->at (0), pkt->at (0), offs);
755
756	duplicate_request: ;
757	}	988	}
758	else
759	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
760	}	989	}
761		990
762	pkt->len = offs;	991	pkt.len = offs;
763	}	992	}
764
765	return pkt;
766	}	993	}
767		994
768	void	995	void
769	vpn::dnsv4_client (dns_packet *pkt)	996	vpn::dnsv4_client (dns_packet &pkt)
770	{	997	{
771	u16 flags = ntohs (pkt->flags);	998	u16 flags = ntohs (pkt.flags);
772	int offs = 6 * 2; // skip header	999	int offs = 6 * 2; // skip header
773		1000
774	pkt->qdcount = ntohs (pkt->qdcount);	1001	pkt.qdcount = ntohs (pkt.qdcount);
775	pkt->ancount = ntohs (pkt->ancount);	1002	pkt.ancount = ntohs (pkt.ancount);
776		1003
777	// go through our request list and find the corresponding request	1004	// go through our request list and find the corresponding request
778	for (vector<dns_req *>::iterator i = dns_sndpq.begin ();	1005	for (vector<dns_snd *>::iterator i = dns_sndpq.begin ();
779	i != dns_sndpq.end ();	1006	i != dns_sndpq.end ();
780	++i)	1007	++i)
781	if ((*i)->pkt->id == pkt->id)	1008	if ((*i)->pkt->id == pkt.id)
782	{	1009	{
783	dns_connection dns = (i)->dns;	1010	dns_connection dns = (i)->dns;
		1011	connection *c = dns->c;
784	int seqno = (*i)->seqno;	1012	int seqno = (*i)->seqno;
785	u8 data[MAXSIZE], *datap = data;	1013	u8 data[MAXSIZE], *datap = data;
786		1014
		1015	if ((*i)->retry)
		1016	{
		1017	dns->send_interval *= 1.01;
		1018	if (dns->send_interval > MAX_SEND_INTERVAL)
		1019	dns->send_interval = MAX_SEND_INTERVAL;
		1020	}
		1021	else
		1022	{
		1023	#if 0
		1024	dns->send_interval *= 0.999;
		1025	#endif
		1026	// the latency surely puts an upper bound on
		1027	// the minimum send interval
		1028	double latency = NOW - (*i)->sent;
		1029
		1030	if (latency < dns->min_latency)
		1031	dns->min_latency = latency;
		1032
		1033	if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
		1034	dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
		1035
		1036	if (dns->send_interval < conf.dns_send_interval)
		1037	dns->send_interval = conf.dns_send_interval;
		1038	}
		1039
787	delete *i;	1040	delete *i;
788	dns_sndpq.erase (i);	1041	dns_sndpq.erase (i);
789		1042
790	if (flags & FLAG_RESPONSE && !(flags & (FLAG_OP_MASK \| FLAG_TC)))	1043	if (flags & FLAG_RESPONSE && !(flags & FLAG_OP_MASK))
791	{	1044	{
792	char qname[MAXSIZE];	1045	char qname[MAXSIZE];
793		1046
794	while (pkt->qdcount-- && offs < MAXSIZE - 4)	1047	while (pkt.qdcount-- && offs < MAXSIZE - 4)
795	{	1048	{
796	int qlen = pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);	1049	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
797	offs += 4; // skip qtype, qclass	1050	offs += 4; // skip qtype, qclass
798	}	1051	}
799		1052
800	while (pkt->ancount-- && offs < MAXSIZE - 10 && datap)	1053	while (pkt.ancount-- && offs < MAXSIZE - 10 && datap)
801	{	1054	{
802	int qlen = pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);	1055	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
803		1056
804	u16 qtype = (pkt) [offs++] << 8; qtype \|= (pkt) [offs++];	1057	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];
805	u16 qclass = (pkt) [offs++] << 8; qclass \|= (pkt) [offs++];	1058	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];
806	u32 ttl = (*pkt) [offs++] << 24;	1059	u32 ttl = pkt [offs++] << 24;
807	ttl \|= (*pkt) [offs++] << 16;	1060	ttl \|= pkt [offs++] << 16;
808	ttl \|= (*pkt) [offs++] << 8;	1061	ttl \|= pkt [offs++] << 8;
809	ttl \|= (*pkt) [offs++];	1062	ttl \|= pkt [offs++];
810
811	u16 rdlen = (pkt) [offs++] << 8; rdlen \|= (pkt) [offs++];	1063	u16 rdlen = pkt [offs++] << 8; rdlen \|= pkt [offs++];
812		1064
813	if (rdlen <= MAXSIZE - offs)	1065	if (qtype == RR_TYPE_NULL \|\| qtype == RR_TYPE_TXT)
814	{	1066	{
815	// decode bytes, finally	1067	if (rdlen <= MAXSIZE - offs)
816
817	while (rdlen)
818	{	1068	{
		1069	// decode bytes, finally
		1070
		1071	while (rdlen)
		1072	{
819	int txtlen = (*pkt) [offs++];	1073	int txtlen = pkt [offs++];
820		1074
821	assert (txtlen + offs < MAXSIZE - 1);	1075	assert (txtlen + offs < MAXSIZE - 1);
822		1076
823	memcpy (datap, pkt->at (offs), txtlen);	1077	memcpy (datap, pkt.at (offs), txtlen);
824	datap += txtlen; offs += txtlen;	1078	datap += txtlen; offs += txtlen;
825		1079
826	rdlen -= txtlen + 1;	1080	rdlen -= txtlen + 1;
		1081	}
827	}	1082	}
828	}	1083	}
		1084	else if (qtype == RR_TYPE_A)
		1085	{
		1086	u8 ip [4];
		1087
		1088	ip [0] = pkt [offs++];
		1089	ip [1] = pkt [offs++];
		1090	ip [2] = pkt [offs++];
		1091	ip [3] = pkt [offs++];
		1092
		1093	if (ip [0] == CMD_IP_1
		1094	&& ip [1] == CMD_IP_2
		1095	&& ip [2] == CMD_IP_3)
		1096	{
		1097	slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]);
		1098
		1099	if (ip [3] == CMD_IP_RST)
		1100	{
		1101	slog (L_DEBUG, _("DNS: got tunnel RST request"));
		1102
		1103	delete dns; c->dns = 0;
		1104
		1105	return;
		1106	}
		1107	else if (ip [3] == CMD_IP_SYN)
		1108	{
		1109	slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us."));
		1110	dns->established = true;
		1111	}
		1112	else if (ip [3] == CMD_IP_REJ)
		1113	{
		1114	slog (L_DEBUG, _("DNS: got tunnel REJ reply, server does not like us, aborting."));
		1115	abort ();
		1116	}
		1117	else
		1118	slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]);
		1119	}
		1120	else
		1121	slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"),
		1122	ip [0], ip [1], ip [2], ip [3]);
		1123
		1124	return;
		1125	}
829		1126
830	int client, rseqno;	1127	int client, rseqno;
831	decode_header (qname, client, rseqno);	1128	decode_header (qname, client, rseqno);
832		1129
833	if (client != THISNODE->id)	1130	if (client != THISNODE->id)
834	{	1131	{
835	slog (L_INFO, _("got dns tunnel response with wrong clientid, ignoring"));	1132	slog (L_INFO, _("DNS: got dns tunnel response with wrong clientid, ignoring"));
836	datap = 0;	1133	datap = 0;
837	}	1134	}
838	else if (rseqno != seqno)	1135	else if (rseqno != seqno)
839	{	1136	{
840	slog (L_DEBUG, _("got dns tunnel response with wrong seqno, badly caching nameserver?"));	1137	slog (L_DEBUG, _("DNS: got dns tunnel response with wrong seqno, badly caching nameserver?"));
841	datap = 0;	1138	datap = 0;
842	}	1139	}
843	}	1140	}
844	}	1141	}
845		1142
…		…
847	if (datap)	1144	if (datap)
848	dns->receive_rep (new dns_rcv (seqno, data, datap - data));	1145	dns->receive_rep (new dns_rcv (seqno, data, datap - data));
849		1146
850	break;	1147	break;
851	}	1148	}
852
853	delete pkt;
854	}	1149	}
855		1150
856	void	1151	void
857	vpn::dnsv4_ev (io_watcher &w, short revents)	1152	vpn::dnsv4_ev (io_watcher &w, short revents)
858	{	1153	{
…		…
860	{	1155	{
861	dns_packet *pkt = new dns_packet;	1156	dns_packet *pkt = new dns_packet;
862	struct sockaddr_in sa;	1157	struct sockaddr_in sa;
863	socklen_t sa_len = sizeof (sa);	1158	socklen_t sa_len = sizeof (sa);
864		1159
865	pkt->len = recvfrom (w.fd, &((pkt)[0]), MAXSIZE, 0, (sockaddr )&sa, &sa_len);	1160	pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
866		1161
867	if (pkt->len > 0)	1162	if (pkt->len > 0)
868	{	1163	{
869	if (pkt->flags & htons (FLAG_TC))	1164	if (ntohs (pkt->flags) & FLAG_RESPONSE)
		1165	dnsv4_client (*pkt);
		1166	else
870	{	1167	{
871	slog (L_WARN, _("DNS request/response truncated, check protocol settings."));	1168	dnsv4_server (*pkt);
872	//TODO connection reset	1169	sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);
873	}	1170	}
874		1171
875	if (THISNODE->dns_port)	1172	delete pkt;
876	{
877	pkt = dnsv4_server (pkt);
878	sendto (w.fd, &((pkt)[0]), pkt->len, 0, (sockaddr )&sa, sa_len);
879	}
880	else
881	dnsv4_client (pkt);
882	}	1173	}
883	}	1174	}
884	}	1175	}
885		1176
886	bool	1177	bool
887	connection::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)	1178	vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
888	{	1179	{
		1180	int client = ntohl (si.host);
		1181
		1182	assert (0 < client && client <= conns.size ());
		1183
		1184	connection *c = conns [client - 1];
		1185
889	if (!dns)	1186	if (!c->dns)
890	dns = new dns_connection (this);	1187	c->dns = new dns_connection (c);
891		1188
892	if (!dns->snddq.put (pkt))	1189	if (c->dns->snddq.put (pkt))
893	return false;
894
895	// start timer if neccessary
896	if (!THISNODE->dns_port && !dns->tw.active)
897	dns->tw.trigger ();	1190	c->dns->tw.trigger ();
898		1191
		1192	// always return true even if the buffer overflows
899	return true;	1193	return true;
900	}	1194	}
		1195
		1196	void
		1197	connection::dnsv4_reset_connection ()
		1198	{
		1199	//delete dns; dns = 0; //TODO
		1200	}
		1201
		1202	#define NEXT(w) do { if (next > (w)) next = w; } while (0)
901		1203
902	void	1204	void
903	dns_connection::time_cb (time_watcher &w)	1205	dns_connection::time_cb (time_watcher &w)
904	{	1206	{
		1207	// servers have to be polled
		1208	if (THISNODE->dns_port)
		1209	return;
		1210
905	// check for timeouts and (re)transmit	1211	// check for timeouts and (re)transmit
906	tstamp next = NOW + 60;	1212	tstamp next = NOW + poll_interval;
907	dns_req *send = 0;	1213	dns_snd *send = 0;
908		1214
909	for (vector<dns_req *>::iterator i = vpn->dns_sndpq.begin ();	1215	for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
910	i != vpn->dns_sndpq.end ();	1216	i != vpn->dns_sndpq.end ();
911	++i)	1217	++i)
912	{	1218	{
913	dns_req r = i;	1219	dns_snd r = i;
914		1220
915	if (r->next <= NOW)	1221	if (r->timeout <= NOW)
916	{	1222	{
917	if (!send)	1223	if (!send)
918	{	1224	{
919	send = r;	1225	send = r;
920		1226
921	if (r->retry)//D
922	printf ("req %d:%d, retry %d\n", r->seqno, r->pkt->id, r->retry);
923	r->retry++;	1227	r->retry++;
924	r->next = NOW + r->retry;	1228	r->timeout = NOW + (r->retry * min_latency * conf.dns_timeout_factor);
		1229
		1230	// the following code changes the query section a bit, forcing
		1231	// the forwarder to generate a new request
		1232	if (r->stdhdr)
		1233	{
		1234	//printf ("reencoded header for ID %d retry %d:%d:%d (%p)\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry);
		1235	//encode_header ((char )r->pkt->at (6 2 + 1), THISNODE->id, r->seqno, r->retry);
		1236	}
925	}	1237	}
926	}	1238	}
927		1239	else
928	if (r->next < next)	1240	NEXT (r->timeout);
929	next = r->next;
930	}	1241	}
931		1242
932	if (!send	1243	if (!send)
933	&& vpn->dns_sndpq.size () < MAX_OUTSTANDING)
934	{	1244	{
		1245	// generate a new packet, if wise
		1246
		1247	if (!established)
		1248	{
		1249	if (vpn->dns_sndpq.empty ())
		1250	{
935	send = new dns_req (this);	1251	send = new dns_snd (this);
		1252
		1253	cfg.reset (THISNODE->id);
		1254	send->gen_syn_req ();
		1255	}
		1256	}
		1257	else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
		1258	&& !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
		1259	{
		1260	if (last_sent + send_interval <= NOW)
		1261	{
		1262	//printf ("sending data request etc.\n"); //D
		1263	if (!snddq.empty () \|\| last_received + 1. > NOW)
		1264	{
		1265	poll_interval = send_interval;
		1266	NEXT (NOW + send_interval);
		1267	}
		1268
		1269	send = new dns_snd (this);
936	send->gen_stream_req (sndseq, snddq);	1270	send->gen_stream_req (sndseq, snddq);
		1271	send->timeout = NOW + min_latency * conf.dns_timeout_factor;
		1272
		1273	sndseq = (sndseq + 1) & SEQNO_MASK;
		1274	}
		1275	else
		1276	NEXT (last_sent + send_interval);
		1277	}
		1278
		1279	if (send)
937	vpn->dns_sndpq.push_back (send);	1280	vpn->dns_sndpq.push_back (send);
938
939	sndseq = (sndseq + 1) & SEQNO_MASK;
940	}	1281	}
941
942	tstamp min_next = NOW + (1. / (tstamp)MAX_RATE);
943		1282
944	if (send)	1283	if (send)
945	{	1284	{
946	dns_packet *pkt = send->pkt;	1285	last_sent = NOW;
947		1286	sendto (vpn->dnsv4_fd,
948	next = min_next;	1287	send->pkt->at (0), send->pkt->len, 0,
949
950	sendto (vpn->dnsv4_fd, &((*pkt)[0]), pkt->len, 0,
951	vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());	1288	vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
952	}	1289	}
953	else if (next < min_next)	1290
954	next = min_next;	1291	slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
		1292	poll_interval, send_interval, next - NOW,
		1293	vpn->dns_sndpq.size (), snddq.size (),
		1294	rcvpq.size ());
		1295
		1296	// TODO: no idea when this happens, but when next < NOW, we have a problem
		1297	// doesn't seem to happen anymore
		1298	if (next < NOW + 0.001)
		1299	next = NOW + 0.1;
955		1300
956	w.start (next);	1301	w.start (next);
957	}	1302	}
958		1303
959	#endif	1304	#endif

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Comparing gvpe/src/vpn_dns.C (file contents): Revision 1.9 by pcg, Fri Mar 4 04:52:38 2005 UTC vs. Revision 1.37 by pcg, Wed Mar 23 17:03:58 2005 UTC

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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.9 by pcg, Fri Mar 4 04:52:38 2005 UTC vs.
Revision 1.37 by pcg, Wed Mar 23 17:03:58 2005 UTC