--- gvpe/src/vpn_dns.C 2005/03/04 03:43:09 1.8 +++ gvpe/src/vpn_dns.C 2005/03/04 04:52:38 1.9 @@ -46,19 +46,18 @@ #include "vpn.h" #define MIN_RETRY 1. -#define MAX_RETRY 60. +#define MAX_RETRY 6. #define MAX_OUTSTANDING 400 // max. outstanding requests #define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING -#define MAX_RATE 10000 // requests/s +#define MAX_RATE 100 // requests/s #define MAX_BACKLOG (10*1024) // size of protocol backlog, must be > MAXSIZE #define MAX_DOMAIN_SIZE 220 // 255 is legal limit, but bind doesn't compress well // 240 leaves about 4 bytes of server reply data // every two request byte sless give room for one reply byte -// seqno has 12 bits (3 bytes a 4 bits in the header) -#define SEQNO_MASK 0x7fff +#define SEQNO_MASK 0xffff #define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) #define MAX_LBL_SIZE 63 @@ -271,8 +270,6 @@ cdc26.decode (hdr, data, HDRSIZE); - printf ("DEC %02x %02x %02x %02x\n", hdr[0], hdr[1], hdr[2], hdr[3]); - clientid = hdr[0]; seqno = (hdr[1] << 8) | hdr[2]; } @@ -364,7 +361,7 @@ #define FLAG_QUERY ( 0 << 15) #define FLAG_RESPONSE ( 1 << 15) -#define FLAG_OP_MASK (15 << 14) +#define FLAG_OP_MASK (15 << 11) #define FLAG_OP_QUERY ( 0 << 11) #define FLAG_AA ( 1 << 10) #define FLAG_TC ( 1 << 9) @@ -433,11 +430,11 @@ dns_packet *pkt; tstamp next; int retry; - connection *conn; + struct dns_connection *dns; int seqno; - dns_req (connection *c); - void gen_stream_req (int seqno, byte_stream *stream); + dns_req (dns_connection *dns); + void gen_stream_req (int seqno, byte_stream &stream); }; static u16 dns_id = 12098; // TODO: should be per-vpn @@ -454,8 +451,8 @@ return dns_id; } -dns_req::dns_req (connection *c) -: conn (c) +dns_req::dns_req (dns_connection *dns) +: dns (dns) { next = 0; retry = 0; @@ -465,7 +462,7 @@ pkt->id = next_id (); } -void dns_req::gen_stream_req (int seqno, byte_stream *stream) +void dns_req::gen_stream_req (int seqno, byte_stream &stream) { this->seqno = seqno; @@ -482,18 +479,11 @@ int datalen = cdc62.decode_len (dlen - (dlen + MAX_LBL_SIZE - 1) / MAX_LBL_SIZE - HDRSIZE); - if (datalen > stream->size ()) - datalen = stream->size (); - - int enclen = cdc62.encode (enc + HDRSIZE, stream->begin (), datalen) + HDRSIZE; + if (datalen > stream.size ()) + datalen = stream.size (); - printf ("cdc62.encode %d->%d:%02x %02x %02x %02x\n", datalen, enclen, - stream->begin ()[0], - stream->begin ()[1], - stream->begin ()[2], - stream->begin ()[3]); - - stream->remove (datalen); + int enclen = cdc62.encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE; + stream.remove (datalen); while (enclen) { @@ -560,6 +550,45 @@ } ///////////////////////////////////////////////////////////////////////////// + +struct dns_connection +{ + connection *c; + struct vpn *vpn; + + vector rcvpq; + + int rcvseq; + int sndseq; + + byte_stream rcvdq; + byte_stream snddq; + + void time_cb (time_watcher &w); time_watcher tw; + void receive_rep (dns_rcv *r); + + dns_connection (connection *c); + ~dns_connection (); +}; + +dns_connection::dns_connection (connection *c) +: c (c) +, rcvdq (MAX_BACKLOG * 2) +, snddq (MAX_BACKLOG * 2) +, tw (this, &dns_connection::time_cb) +{ + vpn = c->vpn; + + rcvseq = sndseq = 0; +} + +dns_connection::~dns_connection () +{ + for (vector::iterator i = rcvpq.begin (); + i != rcvpq.end (); + ++i) + delete *i; +} struct dns_cfg { @@ -570,50 +599,34 @@ u8 flags1, flags2; }; -void connection::dnsv4_receive_rep (struct dns_rcv *r) +void dns_connection::receive_rep (dns_rcv *r) { - dns_rcvpq.push_back (r); + rcvpq.push_back (r); - printf ("%d got inketc %d (%02x %02x %02x %02x)\n", THISNODE->id, r->seqno - ,r->data[0] - ,r->data[1] - ,r->data[2] - ,r->data[3] - ); redo: // find next packet - for (vector::iterator i = dns_rcvpq.end (); i-- != dns_rcvpq.begin (); ) - if (SEQNO_EQ (dns_rcvseq, (*i)->seqno)) + for (vector::iterator i = rcvpq.end (); i-- != rcvpq.begin (); ) + if (SEQNO_EQ (rcvseq, (*i)->seqno)) { // enter the packet into our input stream r = *i; - printf ("%d checking for older packet %d\n", THISNODE->id, dns_rcvseq); // remove the oldest packet, look forward, as it's oldest first - for (vector::iterator j = dns_rcvpq.begin (); j != dns_rcvpq.end (); ++j) - if (SEQNO_EQ ((*j)->seqno, dns_rcvseq - MAX_WINDOW)) + for (vector::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j) + if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW)) { - printf ("%d removing %d\n", THISNODE->id, (*j)->seqno); delete *j; - dns_rcvpq.erase (j); + rcvpq.erase (j); break; } - dns_rcvseq = (dns_rcvseq + 1) & SEQNO_MASK; - - if (!dns_snddq && !dns_rcvdq) - { - dns_rcvdq = new byte_stream (MAX_BACKLOG * 2); - dns_snddq = new byte_stream (MAX_BACKLOG); - - dns_si.set (::conf.dns_forw_host, ::conf.dns_forw_port, PROT_DNSv4); - } + rcvseq = (rcvseq + 1) & SEQNO_MASK; - if (!dns_rcvdq->put (r->data, r->datalen)) + if (!rcvdq.put (r->data, r->datalen)) abort (); // MUST never overflow, can be caused by data corruption, TODO - while (vpn_packet *pkt = dns_rcvdq->get ()) + while (vpn_packet *pkt = rcvdq.get ()) { sockinfo si; si.host = 0; si.port = 0; si.prot = PROT_DNSv4; @@ -636,7 +649,7 @@ pkt->flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); - if (!(flags & (FLAG_RESPONSE | FLAG_OP_MASK | FLAG_TC)) + if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK | FLAG_TC)) && pkt->qdcount == htons (1)) { char qname[MAXSIZE]; @@ -666,21 +679,16 @@ u8 data[MAXSIZE]; int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE)); - printf ("cdc62.decode %d(%d): %02x %02x %02x %02x\n", - qlen - (dlen + 1 + HDRSIZE), datalen - ,data[0] - ,data[1] - ,data[2] - ,data[3]); - - printf ("SRV got %d <%.*s>\n", seqno, qlen, qname + HDRSIZE);//D - printf ("SRV got %d <%.*s>\n", seqno, qlen - (dlen + 1 + HDRSIZE), qname + HDRSIZE);//D - if (0 < client && client <= conns.size ()) { connection *c = conns [client - 1]; - for (vector::iterator i = c->dns_rcvpq.end (); i-- != c->dns_rcvpq.begin (); ) + if (!c->dns) + c->dns = new dns_connection (c); + + dns_connection *dns = c->dns; + + for (vector::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) if (SEQNO_EQ ((*i)->seqno, seqno)) { // already seen that request: simply reply with the cached reply @@ -695,7 +703,7 @@ // new packet, queue dns_rcv *rcv = new dns_rcv (seqno, data, datalen); - c->dnsv4_receive_rep (rcv); + dns->receive_rep (rcv); // now generate reply pkt->ancount = htons (1); // one answer RR @@ -717,19 +725,17 @@ int rdlen_offs = offs += 2; - while (c->dns_snddq - && !c->dns_snddq->empty () - && dlen > 1) + while (dlen > 1 && !dns->snddq.empty ()) { int txtlen = dlen <= 255 ? dlen - 1 : 255; - if (txtlen > c->dns_snddq->size ()) - txtlen = c->dns_snddq->size (); + if (txtlen > dns->snddq.size ()) + txtlen = dns->snddq.size (); (*pkt)[offs++] = txtlen; - memcpy (pkt->at (offs), c->dns_snddq->begin (), txtlen); + memcpy (pkt->at (offs), dns->snddq.begin (), txtlen); offs += txtlen; - c->dns_snddq->remove (txtlen); + dns->snddq.remove (txtlen); dlen -= txtlen + 1; } @@ -774,14 +780,14 @@ ++i) if ((*i)->pkt->id == pkt->id) { - connection *c = (*i)->conn; + dns_connection *dns = (*i)->dns; int seqno = (*i)->seqno; u8 data[MAXSIZE], *datap = data; delete *i; dns_sndpq.erase (i); - if (flags & (FLAG_RESPONSE | FLAG_OP_MASK | FLAG_TC)) + if (flags & FLAG_RESPONSE && !(flags & (FLAG_OP_MASK | FLAG_TC))) { char qname[MAXSIZE]; @@ -791,12 +797,9 @@ offs += 4; // skip qtype, qclass } - while (pkt->ancount-- && offs < MAXSIZE - 10) + while (pkt->ancount-- && offs < MAXSIZE - 10 && datap) { - int qlen = //D - pkt->decode_label ((char *)qname, MAXSIZE - offs, offs); - - printf ("got reply to <%.*s>\n", qlen, qname);//D + int qlen = pkt->decode_label ((char *)qname, MAXSIZE - offs, offs); u16 qtype = (*pkt) [offs++] << 8; qtype |= (*pkt) [offs++]; u16 qclass = (*pkt) [offs++] << 8; qclass |= (*pkt) [offs++]; @@ -822,14 +825,27 @@ rdlen -= txtlen + 1; } - } + int client, rseqno; + decode_header (qname, client, rseqno); + + if (client != THISNODE->id) + { + slog (L_INFO, _("got dns tunnel response with wrong clientid, ignoring")); + datap = 0; + } + else if (rseqno != seqno) + { + slog (L_DEBUG, _("got dns tunnel response with wrong seqno, badly caching nameserver?")); + datap = 0; + } } } // todo: pkt now used - c->dnsv4_receive_rep (new dns_rcv (seqno, data, datap - data)); + if (datap) + dns->receive_rep (new dns_rcv (seqno, data, datap - data)); break; } @@ -870,29 +886,21 @@ bool connection::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) { - // never initialized - if (!dns_snddq && !dns_rcvdq) - { - dns_rcvdq = new byte_stream (MAX_BACKLOG * 2); - dns_snddq = new byte_stream (MAX_BACKLOG); - - //dns_rcvseq = dns_sndseq = 0; - - dns_si.set (::conf.dns_forw_host, ::conf.dns_forw_port, PROT_DNSv4); - } + if (!dns) + dns = new dns_connection (this); - if (!dns_snddq->put (pkt)) + if (!dns->snddq.put (pkt)) return false; // start timer if neccessary - if (!THISNODE->dns_port && !dnsv4_tw.active) - dnsv4_cb (dnsv4_tw); + if (!THISNODE->dns_port && !dns->tw.active) + dns->tw.trigger (); return true; } void -connection::dnsv4_cb (time_watcher &w) +dns_connection::time_cb (time_watcher &w) { // check for timeouts and (re)transmit tstamp next = NOW + 60; @@ -925,10 +933,10 @@ && vpn->dns_sndpq.size () < MAX_OUTSTANDING) { send = new dns_req (this); - send->gen_stream_req (dns_sndseq, dns_snddq); + send->gen_stream_req (sndseq, snddq); vpn->dns_sndpq.push_back (send); - dns_sndseq = (dns_sndseq + 1) & SEQNO_MASK; + sndseq = (sndseq + 1) & SEQNO_MASK; } tstamp min_next = NOW + (1. / (tstamp)MAX_RATE); @@ -939,7 +947,8 @@ next = min_next; - sendto (vpn->dnsv4_fd, &((*pkt)[0]), pkt->len, 0, dns_si.sav4 (), dns_si.salenv4 ()); + sendto (vpn->dnsv4_fd, &((*pkt)[0]), pkt->len, 0, + vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); } else if (next < min_next) next = min_next;