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

Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.7 by pcg, Thu Mar 3 16:54:34 2005 UTC vs.
Revision 1.8 by pcg, Fri Mar 4 03:43:09 2005 UTC

…		…
37	#include <unistd.h>	37	#include <unistd.h>
38	#include <fcntl.h>	38	#include <fcntl.h>
39		39
40	#include <map>	40	#include <map>
41		41
		42	#include <gmp.h>
		43
42	#include "netcompat.h"	44	#include "netcompat.h"
43		45
44	#include "vpn.h"	46	#include "vpn.h"
45		47
46	#define MIN_RETRY 1.	48	#define MIN_RETRY 1.
47	#define MAX_RETRY 60.	49	#define MAX_RETRY 60.
48		50
49	#define MAX_OUTSTANDING 40 // max. outstanding requests	51	#define MAX_OUTSTANDING 400 // max. outstanding requests
50	#define MAX_WINDOW 100 // max. for MAX_OUTSTANDING	52	#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING
51	#define MAX_RATE 1000 // requests/s	53	#define MAX_RATE 10000 // requests/s
52	#define MAX_BACKLOG (10*1024) // size of protocol backlog, must be > MAXSIZE	54	#define MAX_BACKLOG (10*1024) // size of protocol backlog, must be > MAXSIZE
53		55
54	#define MAX_DOMAIN_SIZE 220 // 255 is legal limit, but bind doesn't compress well	56	#define MAX_DOMAIN_SIZE 220 // 255 is legal limit, but bind doesn't compress well
55	// 240 leaves about 4 bytes of server reply data	57	// 240 leaves about 4 bytes of server reply data
56	// every two request byte sless give room for one reply byte	58	// every two request byte sless give room for one reply byte
57		59
58	// seqno has 12 bits, but the lower bit is always left as zero	60	// seqno has 12 bits (3 bytes a 4 bits in the header)
59	// as bind caches ttl=0 records and we have to generate
60	// sequence numbers that always differ case-insensitively
61	#define SEQNO_MASK 0x07ff	61	#define SEQNO_MASK 0x7fff
62		62	#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
63	/*
64
65	protocol, in shorthand :)
66
67	client -> server <req> ANY?
68	server -> client <req> TXT <rep>
69
70	<req> is dns64-encoded <client-id:12><recv-seqno:10>[<send-seqno:10><data>]
71	<rep> is dns64-encoded <0:12><recv-seqno:10>[<send-seqno:10><data>]
72
73	if <client-id> is zero, the connection will be configured:
74
75	<0:12><0:4>client-id:12><default-ttl:8><max-size:16><flags:16>
76
77	*/
78		63
79	#define MAX_LBL_SIZE 63	64	#define MAX_LBL_SIZE 63
80	#define MAX_PKT_SIZE 512	65	#define MAX_PKT_SIZE 512
81		66
82	#define RR_TYPE_TXT 16	67	#define RR_TYPE_TXT 16
83	#define RR_TYPE_ANY 255	68	#define RR_TYPE_ANY 255
84	#define RR_CLASS_IN 1	69	#define RR_CLASS_IN 1
85		70
86	// the "_" is not valid but widely accepted (all octets should be supported, but let's be conservative)	71	// works for cmaps up to 255 (not 256!)
87	struct dns64	72	struct charmap
88	{	73	{
89	static const char encode_chars[64 + 1];	74	enum { INVALID = (u8)255 };
90	static s8 decode_chars[256];
91		75
92	static int encode_len (int bytes) { return (bytes * 8 + 5) / 6; }	76	char encode [256]; // index => char
93	static int decode_len (int bytes) { return (bytes * 6) / 8; }	77	u8 decode [256]; // char => index
		78	unsigned int size;
		79
		80	charmap (const char *cmap);
		81	};
		82
		83	charmap::charmap (const char *cmap)
		84	{
		85	char *enc = encode;
		86	u8 *dec = decode;
		87
		88	memset (enc, (char) 0, 256);
		89	memset (dec, (char)INVALID, 256);
		90
		91	for (size = 0; cmap [size]; size++)
		92	{
		93	enc [size] = cmap [size];
		94	dec [(u8)enc [size]] = size;
		95	}
		96
		97	assert (size < 256);
		98	}
		99
		100	#define MAX_DEC_LEN 500
		101	#define MAX_ENC_LEN (MAX_DEC_LEN * 2)
		102	#define MAX_LIMBS ((MAX_DEC_LEN * 8 + GMP_NUMB_BITS - 1) / GMP_NUMB_BITS)
		103
		104	// ugly. minimum base is 16(!)
		105	struct basecoder
		106	{
		107	charmap cmap;
		108	unsigned int enc_len [MAX_DEC_LEN];
		109	unsigned int dec_len [MAX_ENC_LEN];
		110
		111	unsigned int encode_len (unsigned int len);
		112	unsigned int decode_len (unsigned int len);
		113
94	static int encode (char dst, u8 src, int len);	114	unsigned int encode (char dst, u8 src, unsigned int len);
95	static int decode (u8 dst, char src, int len);	115	unsigned int decode (u8 dst, char src, unsigned int len);
96		116
97	dns64 ();	117	basecoder (const char *cmap);
98	} dns64;	118	};
		119
		120	basecoder::basecoder (const char *cmap)
		121	: cmap (cmap)
		122	{
		123	for (unsigned int len = 0; len < MAX_DEC_LEN; ++len)
		124	{
		125	u8 src [MAX_DEC_LEN];
		126	u8 dst [MAX_ENC_LEN];
		127
		128	memset (src, 255, len);
		129
		130	mp_limb_t m [MAX_LIMBS];
		131	mp_size_t n;
		132
		133	n = mpn_set_str (m, src, len, 256);
		134	n = mpn_get_str (dst, this->cmap.size, m, n);
		135
		136	for (int i = 0; !dst [i]; ++i)
		137	n--;
		138
		139	enc_len [len] = n;
		140	dec_len [n] = len;
		141	}
		142	}
		143
		144	unsigned int basecoder::encode_len (unsigned int len)
		145	{
		146	return enc_len [len];
		147	}
		148
		149	unsigned int basecoder::decode_len (unsigned int len)
		150	{
		151	while (len && !dec_len [len])
		152	--len;
		153
		154	return dec_len [len];
		155	}
		156
		157	unsigned int basecoder::encode (char dst, u8 src, unsigned int len)
		158	{
		159	if (!len)
		160	return 0;
		161
		162	int elen = encode_len (len);
		163
		164	mp_limb_t m [MAX_LIMBS];
		165	mp_size_t n;
		166
		167	u8 dst_ [MAX_ENC_LEN];
		168
		169	n = mpn_set_str (m, src, len, 256);
		170	n = mpn_get_str (dst_, cmap.size, m, n);
		171
		172	int plen = elen; // for padding
		173
		174	while (n < plen)
		175	{
		176	*dst++ = cmap.encode [0];
		177	plen--;
		178	}
		179
		180	for (unsigned int i = n - plen; i < n; ++i)
		181	*dst++ = cmap.encode [dst_ [i]];
		182
		183	return elen;
		184	}
		185
		186	unsigned int basecoder::decode (u8 dst, char src, unsigned int len)
		187	{
		188	if (!len)
		189	return 0;
		190
		191	u8 src_ [MAX_ENC_LEN];
		192	unsigned int elen = 0;
		193
		194	while (len--)
		195	{
		196	u8 val = cmap.decode [(u8)*src++];
		197
		198	if (val != charmap::INVALID)
		199	src_ [elen++] = val;
		200	}
		201
		202	int dlen = decode_len (elen);
		203
		204	mp_limb_t m [MAX_LIMBS];
		205	mp_size_t n;
		206
		207	u8 dst_ [MAX_DEC_LEN];
		208
		209	n = mpn_set_str (m, src_, elen, cmap.size);
		210	n = mpn_get_str (dst_, 256, m, n);
		211
		212	if (n < dlen)
		213	{
		214	memset (dst, 0, dlen - n);
		215	memcpy (dst + dlen - n, dst_, n);
		216	}
		217	else
		218	memcpy (dst, dst_ + n - dlen, dlen);
		219
		220	return dlen;
		221	}
		222
		223	#if 0
		224	struct test { test (); } test;
		225
		226	test::test ()
		227	{
		228	basecoder cdc ("0123456789abcdefghijklmnopqrstuvwxyz");
		229
		230	u8 in[] = "0123456789abcdefghijklmnopqrstuvwxyz";
		231	static char enc[200];
		232	static u8 dec[200];
		233
		234	for (int i = 1; i < 20; i++)
		235	{
		236	int elen = cdc.encode (enc, in, i);
		237	int dlen = cdc.decode (dec, enc, elen);
		238
		239	printf ("%d>%d>%d (%s>%s)\n", i, elen, dlen, enc, dec);
		240	}
		241	abort ();
		242	}
		243	#endif
99		244
100	// the following sequence has been crafted to	245	// the following sequence has been crafted to
101	// a) look somewhat random	246	// a) look somewhat random
102	// b) the even (and odd) indices never share the same character as upper/lowercase	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");
103	const char dns64::encode_chars[64 + 1] = "_-dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI";	251	static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");
104	s8 dns64::decode_chars[256];	252	//static basecoder cdc36 ("dphzr06qmjkb34tsvl81xaef92wgyo57ucni"); // unused as of yet
		253	static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");
105		254
106	dns64::dns64 ()	255	/////////////////////////////////////////////////////////////////////////////
107	{
108	for (int i = 0; i < 64; i++)
109	decode_chars [encode_chars [i]] = i + 1;
110	}
111		256
112	int dns64::encode (char dst, u8 src, int len)	257	#define HDRSIZE 6
113	{
114	// slow, but easy to debug
115	char *beg = dst;
116	unsigned int accum, bits = 0;
117		258
118	while (len--)	259	inline void encode_header (char *data, int clientid, int seqno)
119	{
120	accum <<= 8;
121	accum \|= *src++;
122	bits += 8;
123
124	while (bits >= 6)
125	{
126	*dst++ = encode_chars [(accum >> (bits - 6)) & 63];
127	bits -= 6;
128	}
129	}
130
131	if (bits)
132	*dst++ = encode_chars [(accum << (6 - bits)) & 63];
133
134	return dst - beg;
135	}
136
137	int dns64::decode (u8 dst, char src, int len)
138	{	260	{
139	// slow, but easy to debug	261	u8 hdr[3] = { clientid, seqno >> 8, seqno };
140	u8 *beg = dst;
141	unsigned int accum, bits = 0;
142		262
143	while (len--)	263	assert (clientid < 256);
144	{
145	s8 chr = decode_chars [(u8)*src++];
146		264
147	if (!chr)	265	cdc26.encode (data, hdr, 3);
148	continue;	266	}
149		267
150	accum <<= 6;	268	inline void decode_header (char *data, int &clientid, int &seqno)
151	accum \|= chr - 1;	269	{
152	bits += 6;	270	u8 hdr[3];
153		271
154	while (bits >= 8)	272	cdc26.decode (hdr, data, HDRSIZE);
155	{
156	*dst++ = accum >> (bits - 8);
157	bits -= 8;
158	}
159	}
160		273
161	return dst - beg;	274	printf ("DEC %02x %02x %02x %02x\n", hdr[0], hdr[1], hdr[2], hdr[3]);
		275
		276	clientid = hdr[0];
		277	seqno = (hdr[1] << 8) \| hdr[2];
162	}	278	}
163		279
164	/////////////////////////////////////////////////////////////////////////////	280	/////////////////////////////////////////////////////////////////////////////
165		281
166	struct byte_stream	282	struct byte_stream
…		…
355		471
356	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);	472	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
357	pkt->qdcount = htons (1);	473	pkt->qdcount = htons (1);
358		474
359	int offs = 6*2;	475	int offs = 6*2;
360	int dlen = MAX_DOMAIN_SIZE - strlen (THISNODE->domain) - 2;	476	int dlen = MAX_DOMAIN_SIZE - (strlen (THISNODE->domain) + 2);
361	// MAX_DOMAIN_SIZE is technically 255, but bind doesn't compress responses well,	477	// MAX_DOMAIN_SIZE is technically 255, but bind doesn't compress responses well,
362	// so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra	478	// so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra
363		479
364	u8 data[256]; //TODO	480	char enc[256], *encp = enc;
		481	encode_header (enc, THISNODE->id, seqno);
365		482
366	data[0] = THISNODE->id; //TODO
367	data[1] = seqno >> 7; //TODO
368	data[2] = seqno << 1; //TODO
369
370	int datalen = dns64::decode_len (dlen - (dlen + MAX_LBL_SIZE - 1) / MAX_LBL_SIZE) - 3;	483	int datalen = cdc62.decode_len (dlen - (dlen + MAX_LBL_SIZE - 1) / MAX_LBL_SIZE - HDRSIZE);
371		484
372	if (datalen > stream->size ())	485	if (datalen > stream->size ())
373	datalen = stream->size ();	486	datalen = stream->size ();
374		487
375	char enc[256], *encp = enc;	488	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]);
376		495
377	memcpy (data + 3, stream->begin (), datalen);
378	int enclen = dns64::encode (enc, data, datalen + 3);
379	stream->remove (datalen);	496	stream->remove (datalen);
380		497
381	while (enclen)	498	while (enclen)
382	{	499	{
383	int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE;	500	int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE;
…		…
455		572
456	void connection::dnsv4_receive_rep (struct dns_rcv *r)	573	void connection::dnsv4_receive_rep (struct dns_rcv *r)
457	{	574	{
458	dns_rcvpq.push_back (r);	575	dns_rcvpq.push_back (r);
459		576
		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	);
460	redo:	583	redo:
461		584
		585	// find next packet
462	for (vector<dns_rcv *>::iterator i = dns_rcvpq.begin ();	586	for (vector<dns_rcv *>::iterator i = dns_rcvpq.end (); i-- != dns_rcvpq.begin (); )
463	i != dns_rcvpq.end ();
464	++i)
465	if (dns_rcvseq == (*i)->seqno)	587	if (SEQNO_EQ (dns_rcvseq, (*i)->seqno))
466	{	588	{
		589	// enter the packet into our input stream
467	dns_rcv r = i;	590	r = *i;
		591
		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
		594	for (vector<dns_rcv *>::iterator j = dns_rcvpq.begin (); j != dns_rcvpq.end (); ++j)
		595	if (SEQNO_EQ ((*j)->seqno, dns_rcvseq - MAX_WINDOW))
		596	{
		597	printf ("%d removing %d\n", THISNODE->id, (*j)->seqno);
		598	delete *j;
		599	dns_rcvpq.erase (j);
		600	break;
		601	}
468		602
469	dns_rcvseq = (dns_rcvseq + 1) & SEQNO_MASK;	603	dns_rcvseq = (dns_rcvseq + 1) & SEQNO_MASK;
470		604
471	if (!dns_snddq && !dns_rcvdq)	605	if (!dns_snddq && !dns_rcvdq)
472	{	606	{
…		…
484	sockinfo si;	618	sockinfo si;
485	si.host = 0; si.port = 0; si.prot = PROT_DNSv4;	619	si.host = 0; si.port = 0; si.prot = PROT_DNSv4;
486		620
487	vpn->recv_vpn_packet (pkt, si);	621	vpn->recv_vpn_packet (pkt, si);
488	}	622	}
489	}	623
490	else if ((u32)(i)->seqno - (u32)dns_rcvseq + MAX_WINDOW > MAX_WINDOW 2)	624	// check for further packets
491	{
492	//D
493	//abort();
494	printf ("%d erasing %d (%d)\n", THISNODE->id, (u32)(*i)->seqno, dns_rcvseq);
495	dns_rcvpq.erase (i);
496	goto redo;	625	goto redo;
497	}	626	}
498	}	627	}
499		628
500	dns_packet *	629	dns_packet *
…		…
525		654
526	int dlen = strlen (THISNODE->domain);	655	int dlen = strlen (THISNODE->domain);
527		656
528	if (qclass == RR_CLASS_IN	657	if (qclass == RR_CLASS_IN
529	&& (qtype == RR_TYPE_ANY \|\| qtype == RR_TYPE_TXT)	658	&& (qtype == RR_TYPE_ANY \|\| qtype == RR_TYPE_TXT)
530	&& qlen > dlen + 1	659	&& qlen > dlen + 1 + HDRSIZE
531	&& !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen))	660	&& !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen))
532	{	661	{
533	// correct class, domain: parse	662	// correct class, domain: parse
		663	int client, seqno;
		664	decode_header (qname, client, seqno);
		665
534	u8 data[MAXSIZE];	666	u8 data[MAXSIZE];
535	int datalen = dns64::decode (data, qname, qlen - dlen - 1);	667	int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
536		668
537	int client = data[0];	669	printf ("cdc62.decode %d(%d): %02x %02x %02x %02x\n",
538	int seqno = ((data[1] << 7) \| (data[2] >> 1)) & SEQNO_MASK;	670	qlen - (dlen + 1 + HDRSIZE), datalen
		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
539		678
540	if (0 < client && client <= conns.size ())	679	if (0 < client && client <= conns.size ())
541	{	680	{
542	connection *c = conns [client - 1];	681	connection *c = conns [client - 1];
543		682
544	redo:
545
546	for (vector<dns_rcv *>::iterator i = c->dns_rcvpq.begin ();	683	for (vector<dns_rcv *>::iterator i = c->dns_rcvpq.end (); i-- != c->dns_rcvpq.begin (); )
547	i != c->dns_rcvpq.end ();
548	++i)
549	if ((*i)->seqno == seqno)	684	if (SEQNO_EQ ((*i)->seqno, seqno))
550	{	685	{
551	// already seen that request: simply reply with the cached reply	686	// already seen that request: simply reply with the cached reply
552	dns_rcv r = i;	687	dns_rcv r = i;
553		688
554	printf ("DUPLICATE %d\n", htons (r->pkt->id));//D	689	printf ("DUPLICATE %d\n", htons (r->pkt->id));//D
555		690
556	offs = r->pkt->len;
557	memcpy (pkt->at (0), r->pkt->at (0), offs);	691	memcpy (pkt->at (0), r->pkt->at (0), offs = r->pkt->len);
		692	pkt->id = r->pkt->id;
558	goto duplicate_request;	693	goto duplicate_request;
559	}	694	}
560		695
561	// new packet, queue	696	// new packet, queue
562	dns_rcv *rcv = new dns_rcv (seqno, data + 3, datalen - 3);	697	dns_rcv *rcv = new dns_rcv (seqno, data, datalen);
563	c->dnsv4_receive_rep (rcv);	698	c->dnsv4_receive_rep (rcv);
564		699
565	// now generate reply	700	// now generate reply
566	pkt->ancount = htons (1); // one answer RR	701	pkt->ancount = htons (1); // one answer RR
567	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);	702	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);
…		…
656	offs += 4; // skip qtype, qclass	791	offs += 4; // skip qtype, qclass
657	}	792	}
658		793
659	while (pkt->ancount-- && offs < MAXSIZE - 10)	794	while (pkt->ancount-- && offs < MAXSIZE - 10)
660	{	795	{
		796	int qlen = //D
661	pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);	797	pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);
		798
		799	printf ("got reply to <%.*s>\n", qlen, qname);//D
662		800
663	u16 qtype = (pkt) [offs++] << 8; qtype \|= (pkt) [offs++];	801	u16 qtype = (pkt) [offs++] << 8; qtype \|= (pkt) [offs++];
664	u16 qclass = (pkt) [offs++] << 8; qclass \|= (pkt) [offs++];	802	u16 qclass = (pkt) [offs++] << 8; qclass \|= (pkt) [offs++];
665	u32 ttl = (*pkt) [offs++] << 24;	803	u32 ttl = (*pkt) [offs++] << 24;
666	ttl \|= (*pkt) [offs++] << 16;	804	ttl \|= (*pkt) [offs++] << 16;
…		…
771	if (!send)	909	if (!send)
772	{	910	{
773	send = r;	911	send = r;
774		912
775	if (r->retry)//D	913	if (r->retry)//D
776	printf ("req %d, retry %d\n", r->pkt->id, r->retry);	914	printf ("req %d:%d, retry %d\n", r->seqno, r->pkt->id, r->retry);
777	r->retry++;	915	r->retry++;
778	r->next = NOW + r->retry;	916	r->next = NOW + r->retry;
779	}	917	}
780	}	918	}
781		919

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Comparing gvpe/src/vpn_dns.C (file contents): Revision 1.7 by pcg, Thu Mar 3 16:54:34 2005 UTC vs. Revision 1.8 by pcg, Fri Mar 4 03:43:09 2005 UTC

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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.7 by pcg, Thu Mar 3 16:54:34 2005 UTC vs.
Revision 1.8 by pcg, Fri Mar 4 03:43:09 2005 UTC