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/cvs/gvpe/src/vpn_dns.C
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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.48 by pcg, Tue Jul 28 00:42:14 2009 UTC vs.
Revision 1.50 by root, Sun Mar 6 13:49:50 2011 UTC

… …
117 memset (enc, (char) 0, 256); 117 memset (enc, (char) 0, 256);
118 memset (dec, (char)INVALID, 256); 118 memset (dec, (char)INVALID, 256);
119 119
120 for (size = 0; cmap [size]; size++) 120 for (size = 0; cmap [size]; size++)
121 { 121 {
122 char c = cmap [size];
123
122 enc [size] = cmap [size]; 124 enc [size] = c;
123 dec [(u8)enc [size]] = size; 125 dec [(u8)c] = size;
126
127 // allow lowercase/uppercase aliases if possible
128 if (c >= 'A' && c <= 'Z' && dec [c + ('a' - 'A')] == INVALID) dec [c + ('a' - 'A')] = size;
129 if (c >= 'a' && c <= 'z' && dec [c - ('a' - 'A')] == INVALID) dec [c - ('a' - 'A')] = size;
124 } 130 }
125 131
126 assert (size < 256); 132 assert (size < 256);
127} 133}
128 134
… …
168 enc_len [len] = n; 174 enc_len [len] = n;
169 dec_len [n] = len; 175 dec_len [n] = len;
170 } 176 }
171} 177}
172 178
179unsigned int
173unsigned int basecoder::encode_len (unsigned int len) 180basecoder::encode_len (unsigned int len)
174{ 181{
175 return enc_len [len]; 182 return enc_len [len];
176} 183}
177 184
185unsigned int
178unsigned int basecoder::decode_len (unsigned int len) 186basecoder::decode_len (unsigned int len)
179{ 187{
180 while (len && !dec_len [len]) 188 while (len && !dec_len [len])
181 --len; 189 --len;
182 190
183 return dec_len [len]; 191 return dec_len [len];
184} 192}
185 193
194unsigned int
186unsigned int basecoder::encode (char *dst, u8 *src, unsigned int len) 195basecoder::encode (char *dst, u8 *src, unsigned int len)
187{ 196{
188 if (!len || len > MAX_DEC_LEN) 197 if (!len || len > MAX_DEC_LEN)
189 return 0; 198 return 0;
190 199
191 int elen = encode_len (len); 200 int elen = encode_len (len);
… …
210 *dst++ = cmap.encode [dst_ [i]]; 219 *dst++ = cmap.encode [dst_ [i]];
211 220
212 return elen; 221 return elen;
213} 222}
214 223
224unsigned int
215unsigned int basecoder::decode (u8 *dst, char *src, unsigned int len) 225basecoder::decode (u8 *dst, char *src, unsigned int len)
216{ 226{
217 if (!len || len > MAX_ENC_LEN) 227 if (!len || len > MAX_ENC_LEN)
218 return 0; 228 return 0;
219 229
220 u8 src_ [MAX_ENC_LEN]; 230 u8 src_ [MAX_ENC_LEN];
… …
279 289
280///////////////////////////////////////////////////////////////////////////// 290/////////////////////////////////////////////////////////////////////////////
281 291
282#define HDRSIZE 6 292#define HDRSIZE 6
283 293
294inline void
284inline void encode_header (char *data, int clientid, int seqno, int retry = 0) 295encode_header (char *data, int clientid, int seqno, int retry = 0)
285{ 296{
286 seqno &= SEQNO_MASK; 297 seqno &= SEQNO_MASK;
287 298
288 u8 hdr[3] = { 299 u8 hdr[3] = {
289 clientid, 300 clientid,
… …
294 assert (clientid < 256); 305 assert (clientid < 256);
295 306
296 cdc26.encode (data, hdr, 3); 307 cdc26.encode (data, hdr, 3);
297} 308}
298 309
310inline void
299inline void decode_header (char *data, int &clientid, int &seqno) 311decode_header (char *data, int &clientid, int &seqno)
300{ 312{
301 u8 hdr[3]; 313 u8 hdr[3];
302 314
303 cdc26.decode (hdr, data, HDRSIZE); 315 cdc26.decode (hdr, data, HDRSIZE);
304 316
… …
337byte_stream::~byte_stream () 349byte_stream::~byte_stream ()
338{ 350{
339 delete data; 351 delete data;
340} 352}
341 353
354void
342void byte_stream::remove (int count) 355byte_stream::remove (int count)
343{ 356{
344 if (count > fill) 357 if (count > fill)
345 assert (count <= fill); 358 assert (count <= fill);
346 359
347 memmove (data, data + count, fill -= count); 360 memmove (data, data + count, fill -= count);
348} 361}
349 362
363bool
350bool byte_stream::put (u8 *data, unsigned int datalen) 364byte_stream::put (u8 *data, unsigned int datalen)
351{ 365{
352 if (maxsize - fill < datalen) 366 if (maxsize - fill < datalen)
353 return false; 367 return false;
354 368
355 memcpy (this->data + fill, data, datalen); fill += datalen; 369 memcpy (this->data + fill, data, datalen); fill += datalen;
356 370
357 return true; 371 return true;
358} 372}
359 373
374bool
360bool byte_stream::put (vpn_packet *pkt) 375byte_stream::put (vpn_packet *pkt)
361{ 376{
362 if (maxsize - fill < pkt->len + 2) 377 if (maxsize - fill < pkt->len + 2)
363 return false; 378 return false;
364 379
365 data [fill++] = pkt->len >> 8; 380 data [fill++] = pkt->len >> 8;
… …
447 bool valid (); 462 bool valid ();
448}; 463};
449 464
450int dns_cfg::next_uid; 465int dns_cfg::next_uid;
451 466
467void
452void dns_cfg::reset (int clientid) 468dns_cfg::reset (int clientid)
453{ 469{
454 id1 = 'G'; 470 id1 = 'G';
455 id2 = 'V'; 471 id2 = 'V';
456 id3 = 'P'; 472 id3 = 'P';
457 id4 = 'E'; 473 id4 = 'E';
… …
471 487
472 r3 = r4 = 0; 488 r3 = r4 = 0;
473 r4 = r5 = r6 = r7 = 0; 489 r4 = r5 = r6 = r7 = 0;
474} 490}
475 491
492bool
476bool dns_cfg::valid () 493dns_cfg::valid ()
477{ 494{
478 // although the protocol itself allows for some configurability, 495 // although the protocol itself allows for some configurability,
479 // only the following encoding/decoding settings are implemented. 496 // only the following encoding/decoding settings are implemented.
480 return id1 == 'G' 497 return id1 == 'G'
481 && id2 == 'V' 498 && id2 == 'V'
… …
496 u8 data [MAXSIZE - 6 * 2]; 513 u8 data [MAXSIZE - 6 * 2];
497 514
498 int decode_label (char *data, int size, int &offs); 515 int decode_label (char *data, int size, int &offs);
499}; 516};
500 517
518int
501int dns_packet::decode_label (char *data, int size, int &offs) 519dns_packet::decode_label (char *data, int size, int &offs)
502{ 520{
503 char *orig = data; 521 char *orig = data;
504 522
505 memset (data, 0, size); 523 memset (data, 0, size);
506 524
… …
532 return data - orig; 550 return data - orig;
533} 551}
534 552
535///////////////////////////////////////////////////////////////////////////// 553/////////////////////////////////////////////////////////////////////////////
536 554
555static
556u16 next_id ()
557{
537static u16 dns_id = 0; // TODO: should be per-vpn 558 static u16 dns_id = 0; // TODO: should be per-vpn
538 559
539static u16 next_id ()
540{
541 if (!dns_id) 560 if (!dns_id)
542 dns_id = time (0); 561 dns_id = time (0);
543 562
544 // the simplest lsfr with periodicity 65535 i could find 563 // the simplest lsfr with periodicity 65535 i could find
545 dns_id = (dns_id << 1) 564 dns_id = (dns_id << 1)
… …
613dns_snd::~dns_snd () 632dns_snd::~dns_snd ()
614{ 633{
615 delete pkt; 634 delete pkt;
616} 635}
617 636
637static void
618static void append_domain (dns_packet &pkt, int &offs, const char *domain) 638append_domain (dns_packet &pkt, int &offs, const char *domain)
619{ 639{
620 // add tunnel domain 640 // add tunnel domain
621 for (;;) 641 for (;;)
622 { 642 {
623 const char *end = strchr (domain, '.'); 643 const char *end = strchr (domain, '.');
… …
636 656
637 domain = end + 1; 657 domain = end + 1;
638 } 658 }
639} 659}
640 660
661void
641void dns_snd::gen_stream_req (int seqno, byte_stream &stream) 662dns_snd::gen_stream_req (int seqno, byte_stream &stream)
642{ 663{
643 stdhdr = true; 664 stdhdr = true;
644 this->seqno = seqno; 665 this->seqno = seqno;
645 666
646 timeout = ev_now () + INITIAL_TIMEOUT; 667 timeout = ev_now () + INITIAL_TIMEOUT;
… …
684 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; 705 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN;
685 706
686 pkt->len = offs; 707 pkt->len = offs;
687} 708}
688 709
710void
689void dns_snd::gen_syn_req () 711dns_snd::gen_syn_req ()
690{ 712{
691 timeout = ev_now () + INITIAL_SYN_TIMEOUT; 713 timeout = ev_now () + INITIAL_SYN_TIMEOUT;
692 714
693 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 715 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
694 pkt->qdcount = htons (1); 716 pkt->qdcount = htons (1);
… …
759 i != rcvpq.end (); 781 i != rcvpq.end ();
760 ++i) 782 ++i)
761 delete *i; 783 delete *i;
762} 784}
763 785
786void
764void dns_connection::receive_rep (dns_rcv *r) 787dns_connection::receive_rep (dns_rcv *r)
765{ 788{
766 if (r->datalen) 789 if (r->datalen)
767 { 790 {
768 last_received = ev_now (); 791 last_received = ev_now ();
769 tw (); 792 tw ();
… …
802 825
803 rcvseq = (rcvseq + 1) & SEQNO_MASK; 826 rcvseq = (rcvseq + 1) & SEQNO_MASK;
804 827
805 if (!rcvdq.put (r->data, r->datalen)) 828 if (!rcvdq.put (r->data, r->datalen))
806 { 829 {
830 // MUST never overflow, can be caused by data corruption, TODO
807 slog (L_ERR, "DNS: !rcvdq.put (r->data, r->datalen)"); 831 slog (L_CRIT, "DNS: !rcvdq.put (r->data, r->datalen)");
808 abort (); // MUST never overflow, can be caused by data corruption, TODO 832 c->dnsv4_reset_connection ();
833 return;
809 } 834 }
810 835
811 while (vpn_packet *pkt = rcvdq.get ()) 836 while (vpn_packet *pkt = rcvdq.get ())
812 { 837 {
813 sockinfo si; 838 sockinfo si;
814 si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4; 839 si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4;
815 840
816 vpn->recv_vpn_packet (pkt, si); 841 vpn->recv_vpn_packet (pkt, si);
817
818 delete pkt; 842 delete pkt;
819 } 843 }
820 844
821 // check for further packets 845 // check for further packets
822 goto redo; 846 goto redo;
… …
1120 1144
1121 if (ip [3] == CMD_IP_RST) 1145 if (ip [3] == CMD_IP_RST)
1122 { 1146 {
1123 slog (L_DEBUG, _("DNS: got tunnel RST request")); 1147 slog (L_DEBUG, _("DNS: got tunnel RST request"));
1124 1148
1125 delete dns; c->dns = 0; 1149 c->dnsv4_reset_connection ();
1126
1127 return;
1128 } 1150 }
1129 else if (ip [3] == CMD_IP_SYN) 1151 else if (ip [3] == CMD_IP_SYN)
1130 { 1152 {
1131 slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us.")); 1153 slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us."));
1132 dns->established = true; 1154 dns->established = true;
1133 } 1155 }
1134 else if (ip [3] == CMD_IP_REJ) 1156 else if (ip [3] == CMD_IP_REJ)
1135 {
1136 slog (L_DEBUG, _("DNS: got tunnel REJ reply, server does not like us, aborting.")); 1157 slog (L_ERR, _("DNS: got tunnel REJ reply, server does not like us."));
1137 abort ();
1138 }
1139 else 1158 else
1140 slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]); 1159 slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]);
1141 } 1160 }
1142 else 1161 else
1143 slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"), 1162 slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"),

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