[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 1.38 by pcg, Tue Apr 19 04:23:38 2005 UTC

…		…
17	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
18	along with gvpe; if not, write to the Free Software	18	along with gvpe; if not, write to the Free Software
19	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
20	*/	20	*/
21		21
		22	// TODO: EDNS0 option to increase dns mtu?
		23	// TODO: re-write dns packet parsing/creation using a safe mem-buffer
		24	// to ensure no buffer overflows or similar problems.
		25
22	#include "config.h"	26	#include "config.h"
23		27
24	#if ENABLE_DNS	28	#if ENABLE_DNS
25		29
26	// dns processing is EXTREMELY ugly. For obvious(?) reasons.	30	// dns processing is EXTREMELY ugly. For obvious(?) reasons.
27	// it's a hack, use only in emergency situations please.	31	// it's a hack, use only in emergency situations please.
28		32
29	#include <cstring>	33	#include <cstring>
		34	#include <cassert>
30		35
31	#include <sys/types.h>	36	#include <sys/types.h>
32	#include <sys/socket.h>	37	#include <sys/socket.h>
33	#include <sys/wait.h>	38	#include <sys/wait.h>
34	#include <sys/uio.h>	39	#include <sys/uio.h>
…		…
43		48
44	#include "netcompat.h"	49	#include "netcompat.h"
45		50
46	#include "vpn.h"	51	#include "vpn.h"
47		52
48	#define MIN_RETRY 1.	53	#define MAX_POLL_INTERVAL 5. // how often to poll minimally when the server has no data
49	#define MAX_RETRY 6.	54	#define ACTIVITY_INTERVAL 5.
50		55
51	#define MAX_OUTSTANDING 400 // max. outstanding requests	56	#define INITIAL_TIMEOUT 0.1 // retry timeouts
		57	#define INITIAL_SYN_TIMEOUT 2. // retry timeout for initial syn
		58
		59	#define MAX_SEND_INTERVAL 2. // optimistic?
		60
52	#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING	61	#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	62	#define MAX_BACKLOG (64*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
55		63
56	#define MAX_DOMAIN_SIZE 220 // 255 is legal limit, but bind doesn't compress well	64	#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	65	// 240 leaves about 4 bytes of server reply data
58	// every two request byte sless give room for one reply byte	66	// every request byte less give room for two reply bytes
59		67
60	#define SEQNO_MASK 0xffff	68	#define SEQNO_MASK 0x3fff
61	#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )	69	#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
62		70
63	#define MAX_LBL_SIZE 63	71	#define MAX_LBL_SIZE 63
64	#define MAX_PKT_SIZE 512	72	#define MAX_PKT_SIZE 512
65		73
		74	#define RR_TYPE_A 1
		75	#define RR_TYPE_NULL 10
66	#define RR_TYPE_TXT 16	76	#define RR_TYPE_TXT 16
67	#define RR_TYPE_ANY 255	77	#define RR_TYPE_ANY 255
		78
68	#define RR_CLASS_IN 1	79	#define RR_CLASS_IN 1
		80
		81	#define CMD_IP_1 207
		82	#define CMD_IP_2 46
		83	#define CMD_IP_3 236
		84	#define CMD_IP_RST 29
		85	#define CMD_IP_SYN 113
		86	#define CMD_IP_REJ 32
69		87
70	// works for cmaps up to 255 (not 256!)	88	// works for cmaps up to 255 (not 256!)
71	struct charmap	89	struct charmap
72	{	90	{
73	enum { INVALID = (u8)255 };	91	enum { INVALID = (u8)255 };
…		…
153	return dec_len [len];	171	return dec_len [len];
154	}	172	}
155		173
156	unsigned int basecoder::encode (char dst, u8 src, unsigned int len)	174	unsigned int basecoder::encode (char dst, u8 src, unsigned int len)
157	{	175	{
158	if (!len)	176	if (!len \|\| len > MAX_DEC_LEN)
159	return 0;	177	return 0;
160		178
161	int elen = encode_len (len);	179	int elen = encode_len (len);
162		180
163	mp_limb_t m [MAX_LIMBS];	181	mp_limb_t m [MAX_LIMBS];
…		…
182	return elen;	200	return elen;
183	}	201	}
184		202
185	unsigned int basecoder::decode (u8 dst, char src, unsigned int len)	203	unsigned int basecoder::decode (u8 dst, char src, unsigned int len)
186	{	204	{
187	if (!len)	205	if (!len \|\| len > MAX_ENC_LEN)
188	return 0;	206	return 0;
189		207
190	u8 src_ [MAX_ENC_LEN];	208	u8 src_ [MAX_ENC_LEN];
191	unsigned int elen = 0;	209	unsigned int elen = 0;
192		210
…		…
239	}	257	}
240	abort ();	258	abort ();
241	}	259	}
242	#endif	260	#endif
243		261
244	// the following sequence has been crafted to	262	//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");	263	//static basecoder cdc63 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");
250	static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");	264	static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");
251	//static basecoder cdc36 ("dphzr06qmjkb34tsvl81xaef92wgyo57ucni"); // unused as of yet	265	//static basecoder cdc36 ("dphzr06qmjkb34tsvl81xaef92wgyo57ucni"); // unused as of yet
252	static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");	266	static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");
253		267
254	/////////////////////////////////////////////////////////////////////////////	268	/////////////////////////////////////////////////////////////////////////////
255		269
256	#define HDRSIZE 6	270	#define HDRSIZE 6
257		271
258	inline void encode_header (char *data, int clientid, int seqno)	272	inline void encode_header (char *data, int clientid, int seqno, int retry = 0)
259	{	273	{
260	u8 hdr[3] = { clientid, seqno >> 8, seqno };	274	seqno &= SEQNO_MASK;
		275
		276	u8 hdr[3] = {
		277	clientid,
		278	(seqno >> 8) \| (retry << 6),
		279	seqno,
		280	};
261		281
262	assert (clientid < 256);	282	assert (clientid < 256);
263		283
264	cdc26.encode (data, hdr, 3);	284	cdc26.encode (data, hdr, 3);
265	}	285	}
…		…
269	u8 hdr[3];	289	u8 hdr[3];
270		290
271	cdc26.decode (hdr, data, HDRSIZE);	291	cdc26.decode (hdr, data, HDRSIZE);
272		292
273	clientid = hdr[0];	293	clientid = hdr[0];
274	seqno = (hdr[1] << 8) \| hdr[2];	294	seqno = ((hdr[1] << 8) \| hdr[2]) & SEQNO_MASK;
275	}	295	}
276		296
277	/////////////////////////////////////////////////////////////////////////////	297	/////////////////////////////////////////////////////////////////////////////
278		298
279	struct byte_stream	299	struct byte_stream
…		…
308	}	328	}
309		329
310	void byte_stream::remove (int count)	330	void byte_stream::remove (int count)
311	{	331	{
312	if (count > fill)	332	if (count > fill)
313	abort ();	333	assert (count <= fill);
314		334
315	memmove (data, data + count, fill -= count);	335	memmove (data, data + count, fill -= count);
316	}	336	}
317		337
318	bool byte_stream::put (u8 *data, unsigned int datalen)	338	bool byte_stream::put (u8 *data, unsigned int datalen)
…		…
331	return false;	351	return false;
332		352
333	data [fill++] = pkt->len >> 8;	353	data [fill++] = pkt->len >> 8;
334	data [fill++] = pkt->len;	354	data [fill++] = pkt->len;
335		355
336	memcpy (data + fill, &((*pkt)[0]), pkt->len); fill += pkt->len;	356	memcpy (data + fill, pkt->at (0), pkt->len); fill += pkt->len;
337		357
338	return true;	358	return true;
339	}	359	}
340		360
341	vpn_packet *byte_stream::get ()	361	vpn_packet *byte_stream::get ()
342	{	362	{
		363	unsigned int len;
		364
		365	for (;;)
		366	{
343	int len = (data [0] << 8) \| data [1];	367	len = (data [0] << 8) \| data [1];
344		368
345	if (len > MAXSIZE && fill >= 2)	369	if (len <= MAXSIZE \|\| fill < 2)
346	abort (); // TODO handle this gracefully, connection reset	370	break;
347		371
		372	// TODO: handle this better than skipping, e.g. by reset
		373	slog (L_DEBUG, _("DNS: corrupted packet stream skipping a byte..."));
		374	remove (1);
		375	}
		376
348	if (fill < len + 2)	377	if (fill < len + 2)
349	return 0;	378	return 0;
350		379
351	vpn_packet *pkt = new vpn_packet;	380	vpn_packet *pkt = new vpn_packet;
352		381
353	pkt->len = len;	382	pkt->len = len;
354	memcpy (&((*pkt)[0]), data + 2, len);	383	memcpy (pkt->at (0), data + 2, len);
355	remove (len + 2);	384	remove (len + 2);
356		385
357	return pkt;	386	return pkt;
358	}	387	}
359		388
…		…
376	#define FLAG_RCODE_REFUSED ( 5 << 0)	405	#define FLAG_RCODE_REFUSED ( 5 << 0)
377		406
378	#define DEFAULT_CLIENT_FLAGS (FLAG_QUERY \| FLAG_OP_QUERY \| FLAG_RD)	407	#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)	408	#define DEFAULT_SERVER_FLAGS (FLAG_RESPONSE \| FLAG_OP_QUERY \| FLAG_AA \| FLAG_RD \| FLAG_RA)
380		409
		410	struct dns_cfg
		411	{
		412	static int next_uid;
		413
		414	u8 id1, id2, id3, id4;
		415
		416	u8 version;
		417	u8 flags;
		418	u8 rrtype;
		419	u8 def_ttl;
		420
		421	u16 client;
		422	u16 uid; // to make request unique
		423
		424	u16 max_size;
		425	u8 seq_cdc;
		426	u8 req_cdc;
		427
		428	u8 rep_cdc;
		429	u8 delay; // time in 0.01s units that the server may delay replying packets
		430	u8 r3, r4;
		431
		432	u8 r5, r6, r7, r8;
		433
		434	void reset (int clientid);
		435	bool valid ();
		436	};
		437
		438	int dns_cfg::next_uid;
		439
		440	void dns_cfg::reset (int clientid)
		441	{
		442	id1 = 'G';
		443	id2 = 'V';
		444	id3 = 'P';
		445	id4 = 'E';
		446
		447	version = 1;
		448
		449	rrtype = RR_TYPE_TXT;
		450	flags = 0;
		451	def_ttl = 0;
		452	seq_cdc = 26;
		453	req_cdc = 62;
		454	rep_cdc = 0;
		455	max_size = htons (MAX_PKT_SIZE);
		456	client = htons (clientid);
		457	uid = next_uid++;
		458	delay = 0;
		459
		460	r3 = r4 = 0;
		461	r4 = r5 = r6 = r7 = 0;
		462	}
		463
		464	bool dns_cfg::valid ()
		465	{
		466	return id1 == 'G'
		467	&& id2 == 'V'
		468	&& id3 == 'P'
		469	&& id4 == 'E'
		470	&& seq_cdc == 26
		471	&& req_cdc == 62
		472	&& rep_cdc == 0
		473	&& version == 1;
		474	}
		475
381	struct dns_packet : net_packet	476	struct dns_packet : net_packet
382	{	477	{
383	u16 id;	478	u16 id;
384	u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4	479	u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4
385	u16 qdcount, ancount, nscount, arcount;	480	u16 qdcount, ancount, nscount, arcount;
386		481
387	u8 data[MAXSIZE - 6 * 2];	482	u8 data [MAXSIZE - 6 * 2];
388		483
389	int decode_label (char *data, int size, int &offs);	484	int decode_label (char *data, int size, int &offs);
390	};	485	};
391		486
392	int dns_packet::decode_label (char *data, int size, int &offs)	487	int dns_packet::decode_label (char *data, int size, int &offs)
…		…
423	return data - orig;	518	return data - orig;
424	}	519	}
425		520
426	/////////////////////////////////////////////////////////////////////////////	521	/////////////////////////////////////////////////////////////////////////////
427		522
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	523	static u16 dns_id = 0; // TODO: should be per-vpn
441		524
442	static u16 next_id ()	525	static u16 next_id ()
443	{	526	{
		527	if (!dns_id)
		528	dns_id = time (0);
		529
444	// the simplest lsfr with periodicity 65535 i could find	530	// the simplest lsfr with periodicity 65535 i could find
445	dns_id = (dns_id << 1)	531	dns_id = (dns_id << 1)
446	\| (((dns_id >> 1)	532	\| (((dns_id >> 1)
447	^ (dns_id >> 2)	533	^ (dns_id >> 2)
448	^ (dns_id >> 4)	534	^ (dns_id >> 4)
449	^ (dns_id >> 15)) & 1);	535	^ (dns_id >> 15)) & 1);
450		536
451	return dns_id;	537	return dns_id;
452	}	538	}
453		539
		540	struct dns_rcv;
		541	struct dns_snd;
		542
		543	struct dns_connection
		544	{
		545	connection *c;
		546	struct vpn *vpn;
		547
		548	dns_cfg cfg;
		549
		550	bool established;
		551
		552	tstamp last_received;
		553	tstamp last_sent;
		554	double min_latency;
		555	double poll_interval, send_interval;
		556
		557	vector<dns_rcv *> rcvpq;
		558
		559	byte_stream rcvdq; int rcvseq; int repseq;
		560	byte_stream snddq; int sndseq;
		561
		562	void time_cb (time_watcher &w); time_watcher tw;
		563	void receive_rep (dns_rcv *r);
		564
		565	dns_connection (connection *c);
		566	~dns_connection ();
		567	};
		568
		569	struct dns_snd
		570	{
		571	dns_packet *pkt;
		572	tstamp timeout, sent;
		573	int retry;
		574	struct dns_connection *dns;
		575	int seqno;
		576	bool stdhdr;
		577
		578	void gen_stream_req (int seqno, byte_stream &stream);
		579	void gen_syn_req ();
		580
		581	dns_snd (dns_connection *dns);
		582	~dns_snd ();
		583	};
		584
454	dns_req::dns_req (dns_connection *dns)	585	dns_snd::dns_snd (dns_connection *dns)
455	: dns (dns)	586	: dns (dns)
456	{	587	{
457	next = 0;	588	timeout = 0;
458	retry = 0;	589	retry = 0;
		590	seqno = 0;
		591	sent = NOW;
		592	stdhdr = false;
459		593
460	pkt = new dns_packet;	594	pkt = new dns_packet;
461		595
462	pkt->id = next_id ();	596	pkt->id = next_id ();
463	}	597	}
464		598
		599	dns_snd::~dns_snd ()
		600	{
		601	delete pkt;
		602	}
		603
		604	static void append_domain (dns_packet &pkt, int &offs, const char *domain)
		605	{
		606	// add tunnel domain
		607	for (;;)
		608	{
		609	const char *end = strchr (domain, '.');
		610
		611	if (!end)
		612	end = domain + strlen (domain);
		613
		614	int len = end - domain;
		615
		616	pkt [offs++] = len;
		617	memcpy (pkt.at (offs), domain, len);
		618	offs += len;
		619
		620	if (!*end)
		621	break;
		622
		623	domain = end + 1;
		624	}
		625	}
		626
465	void dns_req::gen_stream_req (int seqno, byte_stream &stream)	627	void dns_snd::gen_stream_req (int seqno, byte_stream &stream)
466	{	628	{
		629	stdhdr = true;
467	this->seqno = seqno;	630	this->seqno = seqno;
		631
		632	timeout = NOW + INITIAL_TIMEOUT;
468		633
469	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);	634	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
470	pkt->qdcount = htons (1);	635	pkt->qdcount = htons (1);
471		636
472	int offs = 6*2;	637	int offs = 6*2;
473	int dlen = MAX_DOMAIN_SIZE - (strlen (THISNODE->domain) + 2);	638	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,	639	// 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	640	// so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra
476		641
477	char enc[256], *encp = enc;	642	char enc[256], *encp = enc;
478	encode_header (enc, THISNODE->id, seqno);	643	encode_header (enc, THISNODE->id, seqno);
…		…
496	encp += lbllen;	661	encp += lbllen;
497		662
498	enclen -= lbllen;	663	enclen -= lbllen;
499	}	664	}
500		665
501	const char *suffix = THISNODE->domain;	666	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		667
523	(*pkt)[offs++] = 0;	668	(*pkt)[offs++] = 0;
524	(pkt)[offs++] = RR_TYPE_ANY >> 8; (pkt)[offs++] = RR_TYPE_ANY;	669	(pkt)[offs++] = RR_TYPE_ANY >> 8; (pkt)[offs++] = RR_TYPE_ANY;
		670	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;
		671
		672	pkt->len = offs;
		673	}
		674
		675	void dns_snd::gen_syn_req ()
		676	{
		677	timeout = NOW + INITIAL_SYN_TIMEOUT;
		678
		679	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
		680	pkt->qdcount = htons (1);
		681
		682	int offs = 6 * 2;
		683
		684	int elen = cdc26.encode ((char )pkt->at (offs + 1), (u8 )&dns->cfg, sizeof (dns_cfg));
		685
		686	assert (elen <= MAX_LBL_SIZE);
		687
		688	(*pkt)[offs] = elen;
		689	offs += elen + 1;
		690	append_domain (*pkt, offs, dns->c->conf->domain);
		691
		692	(*pkt)[offs++] = 0;
		693	(pkt)[offs++] = RR_TYPE_A >> 8; (pkt)[offs++] = RR_TYPE_A;
525	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;	694	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;
526		695
527	pkt->len = offs;	696	pkt->len = offs;
528	}	697	}
529		698
…		…
549	delete pkt;	718	delete pkt;
550	}	719	}
551		720
552	/////////////////////////////////////////////////////////////////////////////	721	/////////////////////////////////////////////////////////////////////////////
553		722
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)	723	dns_connection::dns_connection (connection *c)
575	: c (c)	724	: c (c)
576	, rcvdq (MAX_BACKLOG * 2)	725	, rcvdq (MAX_BACKLOG * 2)
577	, snddq (MAX_BACKLOG * 2)	726	, snddq (MAX_BACKLOG)
578	, tw (this, &dns_connection::time_cb)	727	, tw (this, &dns_connection::time_cb)
579	{	728	{
580	vpn = c->vpn;	729	vpn = c->vpn;
581		730
		731	established = false;
		732
582	rcvseq = sndseq = 0;	733	rcvseq = repseq = sndseq = 0;
		734
		735	last_sent = last_received = 0;
		736	poll_interval = 0.5; // starting here
		737	send_interval = 0.5; // starting rate
		738	min_latency = INITIAL_TIMEOUT;
583	}	739	}
584		740
585	dns_connection::~dns_connection ()	741	dns_connection::~dns_connection ()
586	{	742	{
587	for (vector<dns_rcv *>::iterator i = rcvpq.begin ();	743	for (vector<dns_rcv *>::iterator i = rcvpq.begin ();
588	i != rcvpq.end ();	744	i != rcvpq.end ();
589	++i)	745	++i)
590	delete *i;	746	delete *i;
591	}	747	}
592		748
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)	749	void dns_connection::receive_rep (dns_rcv *r)
603	{	750	{
		751	if (r->datalen)
		752	{
		753	last_received = NOW;
		754	tw.trigger ();
		755
		756	poll_interval = send_interval;
		757	}
		758	else
		759	{
		760	poll_interval *= 1.5;
		761
		762	if (poll_interval > MAX_POLL_INTERVAL)
		763	poll_interval = MAX_POLL_INTERVAL;
		764	}
		765
604	rcvpq.push_back (r);	766	rcvpq.push_back (r);
605		767
606	redo:	768	redo:
607		769
608	// find next packet	770	// find next packet
…		…
622	}	784	}
623		785
624	rcvseq = (rcvseq + 1) & SEQNO_MASK;	786	rcvseq = (rcvseq + 1) & SEQNO_MASK;
625		787
626	if (!rcvdq.put (r->data, r->datalen))	788	if (!rcvdq.put (r->data, r->datalen))
		789	{
		790	slog (L_ERR, "DNS: !rcvdq.put (r->data, r->datalen)");
627	abort (); // MUST never overflow, can be caused by data corruption, TODO	791	abort (); // MUST never overflow, can be caused by data corruption, TODO
		792	}
628		793
629	while (vpn_packet *pkt = rcvdq.get ())	794	while (vpn_packet *pkt = rcvdq.get ())
630	{	795	{
631	sockinfo si;	796	sockinfo si;
632	si.host = 0; si.port = 0; si.prot = PROT_DNSv4;	797	si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4;
633		798
634	vpn->recv_vpn_packet (pkt, si);	799	vpn->recv_vpn_packet (pkt, si);
		800
		801	delete pkt;
635	}	802	}
636		803
637	// check for further packets	804	// check for further packets
638	goto redo;	805	goto redo;
639	}	806	}
640	}	807	}
641		808
642	dns_packet *	809	void
643	vpn::dnsv4_server (dns_packet *pkt)	810	vpn::dnsv4_server (dns_packet &pkt)
644	{	811	{
645	u16 flags = ntohs (pkt->flags);	812	u16 flags = ntohs (pkt.flags);
646		813
647	//memcpy (&((rep)[0]), &((pkt)[0]), pkt->len);
648	int offs = 6 * 2; // skip header	814	int offs = 6 * 2; // skip header
649		815
650	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);	816	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
651		817
652	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK \| FLAG_TC))	818	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK))
653	&& pkt->qdcount == htons (1))	819	&& pkt.qdcount == htons (1))
654	{	820	{
655	char qname[MAXSIZE];	821	char qname [MAXSIZE];
656	int qlen = pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);	822	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
657		823
658	u16 qtype = (pkt) [offs++] << 8; qtype \|= (pkt) [offs++];	824	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];
659	u16 qclass = (pkt) [offs++] << 8; qclass \|= (pkt) [offs++];	825	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];
660		826
661	pkt->qdcount = htons (1);	827	pkt.qdcount = htons (1);
662	pkt->ancount = 0;	828	pkt.ancount = 0;
663	pkt->nscount = 0; // should be self, as other nameservers reply like this	829	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	830	pkt.arcount = 0; // a record for self, as other nameservers reply like this
665		831
666	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_NXDOMAIN);	832	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_SERVFAIL);
667		833
668	int dlen = strlen (THISNODE->domain);	834	int dlen = strlen (THISNODE->domain);
669		835
670	if (qclass == RR_CLASS_IN	836	if (qclass == RR_CLASS_IN
671	&& (qtype == RR_TYPE_ANY \|\| qtype == RR_TYPE_TXT)
672	&& qlen > dlen + 1 + HDRSIZE	837	&& qlen > dlen + 1
673	&& !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen))	838	&& !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen))
674	{	839	{
675	// correct class, domain: parse	840	// now generate reply
676	int client, seqno;	841	pkt.ancount = htons (1); // one answer RR
677	decode_header (qname, client, seqno);	842	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);
678		843
679	u8 data[MAXSIZE];	844	if ((qtype == RR_TYPE_ANY
680	int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));	845	\|\| qtype == RR_TYPE_TXT
681		846	\|\| qtype == RR_TYPE_NULL)
682	if (0 < client && client <= conns.size ())	847	&& qlen > dlen + 1 + HDRSIZE)
683	{	848	{
		849	// correct class, domain: parse
		850	int client, seqno;
		851	decode_header (qname, client, seqno);
		852
		853	u8 data[MAXSIZE];
		854	int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
		855
		856	if (0 < client && client <= conns.size ())
		857	{
684	connection *c = conns [client - 1];	858	connection *c = conns [client - 1];
685
686	if (!c->dns)
687	c->dns = new dns_connection (c);
688
689	dns_connection *dns = c->dns;	859	dns_connection *dns = c->dns;
		860	dns_rcv *rcv;
690		861
		862	if (dns)
		863	{
691	for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )	864	for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
692	if (SEQNO_EQ ((*i)->seqno, seqno))	865	if (SEQNO_EQ ((*i)->seqno, seqno))
		866	{
		867	// already seen that request: simply reply with the cached reply
		868	dns_rcv r = i;
		869
		870	slog (L_DEBUG, "DNS: duplicate packet received ID %d, SEQ %d", htons (r->pkt->id), seqno);
		871
		872	// refresh header & id, as the retry count could have changed
		873	memcpy (r->pkt->at (6 * 2 + 1), pkt.at (6 * 2 + 1), HDRSIZE);
		874	r->pkt->id = pkt.id;
		875
		876	memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
		877
		878	goto duplicate_request;
		879	}
		880
		881	// new packet, queue
		882	rcv = new dns_rcv (seqno, data, datalen);
		883	dns->receive_rep (rcv);
		884	}
		885
693	{	886	{
694	// already seen that request: simply reply with the cached reply	887	pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section
695	dns_rcv r = i;
696		888
697	printf ("DUPLICATE %d\n", htons (r->pkt->id));//D	889	int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;
		890	pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type
		891	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
		892	pkt [offs++] = 0; pkt [offs++] = 0;
		893	pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
698		894
699	memcpy (pkt->at (0), r->pkt->at (0), offs = r->pkt->len);	895	int rdlen_offs = offs += 2;
700	pkt->id = r->pkt->id;	896
701	goto duplicate_request;	897	if (dns)
		898	{
		899	int dlen = ntohs (dns->cfg.max_size) - offs;
		900
		901	// bind doesn't compress well, so reduce further by one label length
		902	dlen -= qlen;
		903
		904	// only put data into in-order sequence packets, if
		905	// we receive out-of-order packets we generate empty
		906	// replies
		907	//printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D
		908	if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW)
		909	{
		910	dns->repseq = seqno;
		911
		912	while (dlen > 1 && !dns->snddq.empty ())
		913	{
		914	int txtlen = dlen <= 255 ? dlen - 1 : 255;
		915
		916	if (txtlen > dns->snddq.size ())
		917	txtlen = dns->snddq.size ();
		918
		919	pkt[offs++] = txtlen;
		920	memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
		921	offs += txtlen;
		922	dns->snddq.remove (txtlen);
		923
		924	dlen -= txtlen + 1;
		925	}
		926	}
		927
		928	// avoid completely empty TXT rdata
		929	if (offs == rdlen_offs)
		930	pkt[offs++] = 0;
		931
		932	slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
		933	}
		934	else
		935	{
		936	// send RST
		937	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
		938	pkt [offs++] = CMD_IP_RST;
		939	}
		940
		941	int rdlen = offs - rdlen_offs;
		942
		943	pkt [rdlen_offs - 2] = rdlen >> 8;
		944	pkt [rdlen_offs - 1] = rdlen;
		945
		946	if (dns)
		947	{
		948	// now update dns_rcv copy
		949	rcv->pkt->len = offs;
		950	memcpy (rcv->pkt->at (0), pkt.at (0), offs);
		951	}
702	}	952	}
703		953
704	// new packet, queue	954	duplicate_request: ;
705	dns_rcv *rcv = new dns_rcv (seqno, data, datalen);	955	}
706	dns->receive_rep (rcv);	956	else
707
708	// now generate reply
709	pkt->ancount = htons (1); // one answer RR
710	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);	957	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
		958	}
		959	else if (qtype == RR_TYPE_A
		960	&& qlen > dlen + 1 + cdc26.encode_len (sizeof (dns_cfg)))
		961	{
		962	dns_cfg cfg;
		963	cdc26.decode ((u8 *)&cfg, qname, cdc26.encode_len (sizeof (dns_cfg)));
		964	int client = ntohs (cfg.client);
711		965
712	(*pkt) [offs++] = 0xc0;
713	(pkt) [offs++] = 6 2; // same as in query section	966	pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section
714		967
715	(pkt) [offs++] = RR_TYPE_TXT >> 8; (pkt) [offs++] = RR_TYPE_TXT;	968	pkt [offs++] = RR_TYPE_A >> 8; pkt [offs++] = RR_TYPE_A; // type
716	(pkt) [offs++] = RR_CLASS_IN >> 8; (pkt) [offs++] = RR_CLASS_IN;	969	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
717
718	(pkt) [offs++] = 0; (pkt) [offs++] = 0;	970	pkt [offs++] = 0; pkt [offs++] = 0;
719	(pkt) [offs++] = 0; (pkt) [offs++] = 0; // TTL	971	pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
		972	pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
720		973
721	int dlen = MAX_PKT_SIZE - offs - 2;	974	slog (L_INFO, _("DNS: client %d connects"), client);
722		975
723	// bind doesn't compress well, so reduce further by one label length	976	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
724	dlen -= qlen;	977	pkt [offs++] = CMD_IP_REJ;
725		978
726	int rdlen_offs = offs += 2;	979	if (0 < client && client <= conns.size ())
727
728	while (dlen > 1 && !dns->snddq.empty ())
729	{	980	{
730	int txtlen = dlen <= 255 ? dlen - 1 : 255;	981	connection *c = conns [client - 1];
731		982
732	if (txtlen > dns->snddq.size ())	983	if (cfg.valid ())
733	txtlen = dns->snddq.size ();	984	{
		985	pkt [offs - 1] = CMD_IP_SYN;
734		986
735	(*pkt)[offs++] = txtlen;	987	delete c->dns;
736	memcpy (pkt->at (offs), dns->snddq.begin (), txtlen);	988	c->dns = new dns_connection (c);
737	offs += txtlen;	989	c->dns->cfg = cfg;
738	dns->snddq.remove (txtlen);	990	}
739
740	dlen -= txtlen + 1;
741	}	991	}
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	}	992	}
758	else
759	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
760	}	993	}
761		994
762	pkt->len = offs;	995	pkt.len = offs;
763	}	996	}
764
765	return pkt;
766	}	997	}
767		998
768	void	999	void
769	vpn::dnsv4_client (dns_packet *pkt)	1000	vpn::dnsv4_client (dns_packet &pkt)
770	{	1001	{
771	u16 flags = ntohs (pkt->flags);	1002	u16 flags = ntohs (pkt.flags);
772	int offs = 6 * 2; // skip header	1003	int offs = 6 * 2; // skip header
773		1004
774	pkt->qdcount = ntohs (pkt->qdcount);	1005	pkt.qdcount = ntohs (pkt.qdcount);
775	pkt->ancount = ntohs (pkt->ancount);	1006	pkt.ancount = ntohs (pkt.ancount);
776		1007
777	// go through our request list and find the corresponding request	1008	// go through our request list and find the corresponding request
778	for (vector<dns_req *>::iterator i = dns_sndpq.begin ();	1009	for (vector<dns_snd *>::iterator i = dns_sndpq.begin ();
779	i != dns_sndpq.end ();	1010	i != dns_sndpq.end ();
780	++i)	1011	++i)
781	if ((*i)->pkt->id == pkt->id)	1012	if ((*i)->pkt->id == pkt.id)
782	{	1013	{
783	dns_connection dns = (i)->dns;	1014	dns_connection dns = (i)->dns;
		1015	connection *c = dns->c;
784	int seqno = (*i)->seqno;	1016	int seqno = (*i)->seqno;
785	u8 data[MAXSIZE], *datap = data;	1017	u8 data[MAXSIZE], *datap = data;
786		1018
		1019	if ((*i)->retry)
		1020	{
		1021	dns->send_interval *= 1.01;
		1022	if (dns->send_interval > MAX_SEND_INTERVAL)
		1023	dns->send_interval = MAX_SEND_INTERVAL;
		1024	}
		1025	else
		1026	{
		1027	#if 0
		1028	dns->send_interval *= 0.999;
		1029	#endif
		1030	// the latency surely puts an upper bound on
		1031	// the minimum send interval
		1032	double latency = NOW - (*i)->sent;
		1033
		1034	if (latency < dns->min_latency)
		1035	dns->min_latency = latency;
		1036
		1037	if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
		1038	dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
		1039
		1040	if (dns->send_interval < conf.dns_send_interval)
		1041	dns->send_interval = conf.dns_send_interval;
		1042	}
		1043
787	delete *i;	1044	delete *i;
788	dns_sndpq.erase (i);	1045	dns_sndpq.erase (i);
789		1046
790	if (flags & FLAG_RESPONSE && !(flags & (FLAG_OP_MASK \| FLAG_TC)))	1047	if (flags & FLAG_RESPONSE && !(flags & FLAG_OP_MASK))
791	{	1048	{
792	char qname[MAXSIZE];	1049	char qname[MAXSIZE];
793		1050
794	while (pkt->qdcount-- && offs < MAXSIZE - 4)	1051	while (pkt.qdcount-- && offs < MAXSIZE - 4)
795	{	1052	{
796	int qlen = pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);	1053	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
797	offs += 4; // skip qtype, qclass	1054	offs += 4; // skip qtype, qclass
798	}	1055	}
799		1056
800	while (pkt->ancount-- && offs < MAXSIZE - 10 && datap)	1057	while (pkt.ancount-- && offs < MAXSIZE - 10 && datap)
801	{	1058	{
802	int qlen = pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);	1059	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
803		1060
804	u16 qtype = (pkt) [offs++] << 8; qtype \|= (pkt) [offs++];	1061	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];
805	u16 qclass = (pkt) [offs++] << 8; qclass \|= (pkt) [offs++];	1062	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];
806	u32 ttl = (*pkt) [offs++] << 24;	1063	u32 ttl = pkt [offs++] << 24;
807	ttl \|= (*pkt) [offs++] << 16;	1064	ttl \|= pkt [offs++] << 16;
808	ttl \|= (*pkt) [offs++] << 8;	1065	ttl \|= pkt [offs++] << 8;
809	ttl \|= (*pkt) [offs++];	1066	ttl \|= pkt [offs++];
810
811	u16 rdlen = (pkt) [offs++] << 8; rdlen \|= (pkt) [offs++];	1067	u16 rdlen = pkt [offs++] << 8; rdlen \|= pkt [offs++];
812		1068
813	if (rdlen <= MAXSIZE - offs)	1069	if (qtype == RR_TYPE_NULL \|\| qtype == RR_TYPE_TXT)
814	{	1070	{
815	// decode bytes, finally	1071	if (rdlen <= MAXSIZE - offs)
816
817	while (rdlen)
818	{	1072	{
		1073	// decode bytes, finally
		1074
		1075	while (rdlen)
		1076	{
819	int txtlen = (*pkt) [offs++];	1077	int txtlen = pkt [offs++];
820		1078
821	assert (txtlen + offs < MAXSIZE - 1);	1079	assert (txtlen + offs < MAXSIZE - 1);
822		1080
823	memcpy (datap, pkt->at (offs), txtlen);	1081	memcpy (datap, pkt.at (offs), txtlen);
824	datap += txtlen; offs += txtlen;	1082	datap += txtlen; offs += txtlen;
825		1083
826	rdlen -= txtlen + 1;	1084	rdlen -= txtlen + 1;
		1085	}
827	}	1086	}
828	}	1087	}
		1088	else if (qtype == RR_TYPE_A)
		1089	{
		1090	u8 ip [4];
		1091
		1092	ip [0] = pkt [offs++];
		1093	ip [1] = pkt [offs++];
		1094	ip [2] = pkt [offs++];
		1095	ip [3] = pkt [offs++];
		1096
		1097	if (ip [0] == CMD_IP_1
		1098	&& ip [1] == CMD_IP_2
		1099	&& ip [2] == CMD_IP_3)
		1100	{
		1101	slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]);
		1102
		1103	if (ip [3] == CMD_IP_RST)
		1104	{
		1105	slog (L_DEBUG, _("DNS: got tunnel RST request"));
		1106
		1107	delete dns; c->dns = 0;
		1108
		1109	return;
		1110	}
		1111	else if (ip [3] == CMD_IP_SYN)
		1112	{
		1113	slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us."));
		1114	dns->established = true;
		1115	}
		1116	else if (ip [3] == CMD_IP_REJ)
		1117	{
		1118	slog (L_DEBUG, _("DNS: got tunnel REJ reply, server does not like us, aborting."));
		1119	abort ();
		1120	}
		1121	else
		1122	slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]);
		1123	}
		1124	else
		1125	slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"),
		1126	ip [0], ip [1], ip [2], ip [3]);
		1127
		1128	return;
		1129	}
829		1130
830	int client, rseqno;	1131	int client, rseqno;
831	decode_header (qname, client, rseqno);	1132	decode_header (qname, client, rseqno);
832		1133
833	if (client != THISNODE->id)	1134	if (client != THISNODE->id)
834	{	1135	{
835	slog (L_INFO, _("got dns tunnel response with wrong clientid, ignoring"));	1136	slog (L_INFO, _("DNS: got dns tunnel response with wrong clientid, ignoring"));
836	datap = 0;	1137	datap = 0;
837	}	1138	}
838	else if (rseqno != seqno)	1139	else if (rseqno != seqno)
839	{	1140	{
840	slog (L_DEBUG, _("got dns tunnel response with wrong seqno, badly caching nameserver?"));	1141	slog (L_DEBUG, _("DNS: got dns tunnel response with wrong seqno, badly caching nameserver?"));
841	datap = 0;	1142	datap = 0;
842	}	1143	}
843	}	1144	}
844	}	1145	}
845		1146
…		…
847	if (datap)	1148	if (datap)
848	dns->receive_rep (new dns_rcv (seqno, data, datap - data));	1149	dns->receive_rep (new dns_rcv (seqno, data, datap - data));
849		1150
850	break;	1151	break;
851	}	1152	}
852
853	delete pkt;
854	}	1153	}
855		1154
856	void	1155	void
857	vpn::dnsv4_ev (io_watcher &w, short revents)	1156	vpn::dnsv4_ev (io_watcher &w, short revents)
858	{	1157	{
…		…
860	{	1159	{
861	dns_packet *pkt = new dns_packet;	1160	dns_packet *pkt = new dns_packet;
862	struct sockaddr_in sa;	1161	struct sockaddr_in sa;
863	socklen_t sa_len = sizeof (sa);	1162	socklen_t sa_len = sizeof (sa);
864		1163
865	pkt->len = recvfrom (w.fd, &((pkt)[0]), MAXSIZE, 0, (sockaddr )&sa, &sa_len);	1164	pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
866		1165
867	if (pkt->len > 0)	1166	if (pkt->len > 0)
868	{	1167	{
869	if (pkt->flags & htons (FLAG_TC))	1168	if (ntohs (pkt->flags) & FLAG_RESPONSE)
		1169	dnsv4_client (*pkt);
		1170	else
870	{	1171	{
871	slog (L_WARN, _("DNS request/response truncated, check protocol settings."));	1172	dnsv4_server (*pkt);
872	//TODO connection reset	1173	sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);
873	}	1174	}
874		1175
875	if (THISNODE->dns_port)	1176	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	}	1177	}
883	}	1178	}
884	}	1179	}
885		1180
886	bool	1181	bool
887	connection::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)	1182	vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
888	{	1183	{
		1184	int client = ntohl (si.host);
		1185
		1186	assert (0 < client && client <= conns.size ());
		1187
		1188	connection *c = conns [client - 1];
		1189
889	if (!dns)	1190	if (!c->dns)
890	dns = new dns_connection (this);	1191	c->dns = new dns_connection (c);
891		1192
892	if (!dns->snddq.put (pkt))	1193	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 ();	1194	c->dns->tw.trigger ();
898		1195
		1196	// always return true even if the buffer overflows
899	return true;	1197	return true;
900	}	1198	}
		1199
		1200	void
		1201	connection::dnsv4_reset_connection ()
		1202	{
		1203	//delete dns; dns = 0; //TODO
		1204	}
		1205
		1206	#define NEXT(w) do { if (next > (w)) next = w; } while (0)
901		1207
902	void	1208	void
903	dns_connection::time_cb (time_watcher &w)	1209	dns_connection::time_cb (time_watcher &w)
904	{	1210	{
		1211	// servers have to be polled
		1212	if (THISNODE->dns_port)
		1213	return;
		1214
905	// check for timeouts and (re)transmit	1215	// check for timeouts and (re)transmit
906	tstamp next = NOW + 60;	1216	tstamp next = NOW + poll_interval;
907	dns_req *send = 0;	1217	dns_snd *send = 0;
908		1218
909	for (vector<dns_req *>::iterator i = vpn->dns_sndpq.begin ();	1219	for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
910	i != vpn->dns_sndpq.end ();	1220	i != vpn->dns_sndpq.end ();
911	++i)	1221	++i)
912	{	1222	{
913	dns_req r = i;	1223	dns_snd r = i;
914		1224
915	if (r->next <= NOW)	1225	if (r->timeout <= NOW)
916	{	1226	{
917	if (!send)	1227	if (!send)
918	{	1228	{
919	send = r;	1229	send = r;
920		1230
921	if (r->retry)//D
922	printf ("req %d:%d, retry %d\n", r->seqno, r->pkt->id, r->retry);
923	r->retry++;	1231	r->retry++;
924	r->next = NOW + r->retry;	1232	r->timeout = NOW + (r->retry * min_latency * conf.dns_timeout_factor);
		1233
		1234	// the following code changes the query section a bit, forcing
		1235	// the forwarder to generate a new request
		1236	if (r->stdhdr)
		1237	{
		1238	//printf ("reencoded header for ID %d retry %d:%d:%d (%p)\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry);
		1239	//encode_header ((char )r->pkt->at (6 2 + 1), THISNODE->id, r->seqno, r->retry);
		1240	}
925	}	1241	}
926	}	1242	}
927		1243	else
928	if (r->next < next)	1244	NEXT (r->timeout);
929	next = r->next;
930	}	1245	}
931		1246
932	if (!send	1247	if (!send)
933	&& vpn->dns_sndpq.size () < MAX_OUTSTANDING)
934	{	1248	{
		1249	// generate a new packet, if wise
		1250
		1251	if (!established)
		1252	{
		1253	if (vpn->dns_sndpq.empty ())
		1254	{
935	send = new dns_req (this);	1255	send = new dns_snd (this);
		1256
		1257	cfg.reset (THISNODE->id);
		1258	send->gen_syn_req ();
		1259	}
		1260	}
		1261	else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
		1262	&& !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
		1263	{
		1264	if (last_sent + send_interval <= NOW)
		1265	{
		1266	//printf ("sending data request etc.\n"); //D
		1267	if (!snddq.empty () \|\| last_received + 1. > NOW)
		1268	{
		1269	poll_interval = send_interval;
		1270	NEXT (NOW + send_interval);
		1271	}
		1272
		1273	send = new dns_snd (this);
936	send->gen_stream_req (sndseq, snddq);	1274	send->gen_stream_req (sndseq, snddq);
		1275	send->timeout = NOW + min_latency * conf.dns_timeout_factor;
		1276
		1277	sndseq = (sndseq + 1) & SEQNO_MASK;
		1278	}
		1279	else
		1280	NEXT (last_sent + send_interval);
		1281	}
		1282
		1283	if (send)
937	vpn->dns_sndpq.push_back (send);	1284	vpn->dns_sndpq.push_back (send);
938
939	sndseq = (sndseq + 1) & SEQNO_MASK;
940	}	1285	}
941
942	tstamp min_next = NOW + (1. / (tstamp)MAX_RATE);
943		1286
944	if (send)	1287	if (send)
945	{	1288	{
946	dns_packet *pkt = send->pkt;	1289	last_sent = NOW;
947		1290	sendto (vpn->dnsv4_fd,
948	next = min_next;	1291	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 ());	1292	vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
952	}	1293	}
953	else if (next < min_next)	1294
954	next = min_next;	1295	slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
		1296	poll_interval, send_interval, next - NOW,
		1297	vpn->dns_sndpq.size (), snddq.size (),
		1298	rcvpq.size ());
		1299
		1300	// TODO: no idea when this happens, but when next < NOW, we have a problem
		1301	// doesn't seem to happen anymore
		1302	if (next < NOW + 0.001)
		1303	next = NOW + 0.1;
955		1304
956	w.start (next);	1305	w.start (next);
957	}	1306	}
958		1307
959	#endif	1308	#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 1.38 by pcg, Tue Apr 19 04:23:38 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 1.38 by pcg, Tue Apr 19 04:23:38 2005 UTC