X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=adns.git;a=blobdiff_plain;f=src%2Freply.c;h=64b41d72ce82688d88c2c923791f3b3da70d77a2;hp=ab7c8ff4aadbc37c6cdb589baf43b49aa384cc88;hb=2dee2b7a71c858a78d06814eb98f23ede5602e37;hpb=660d7d3b4af029c3e86fdfe1ac078815c41ed79e diff --git a/src/reply.c b/src/reply.c index ab7c8ff..64b41d7 100644 --- a/src/reply.c +++ b/src/reply.c @@ -3,7 +3,11 @@ * - main handling and parsing routine for received datagrams */ /* - * This file is part of adns, which is Copyright (C) 1997-1999 Ian Jackson + * This file is part of adns, which is + * Copyright (C) 1997-2000,2003,2006 Ian Jackson + * Copyright (C) 1999-2000,2003,2006 Tony Finch + * Copyright (C) 1991 Massachusetts Institute of Technology + * (See the file INSTALL for full details.) * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -21,12 +25,11 @@ */ #include -#include #include "internal.h" void adns__procdgram(adns_state ads, const byte *dgram, int dglen, - int serv, struct timeval now) { + int serv, int viatcp, struct timeval now) { int cbyte, rrstart, wantedrrs, rri, foundsoa, foundns, cname_here; int id, f1, f2, qdcount, ancount, nscount, arcount; int flg_ra, flg_rd, flg_tc, flg_qr, opcode; @@ -43,7 +46,8 @@ void adns__procdgram(adns_state ads, const byte *dgram, int dglen, parseinfo pai; if (dglen1) { - adns__diag(ads,serv,0,"server claimed to answer %d questions with one message", - qdcount); - return; - } - for (qu= ads->timew.head; qu; qu= nqu) { - nqu= qu->next; - if (qu->id != id) continue; - if (dglen < qu->query_dglen) continue; - if (memcmp(qu->query_dgram+DNS_HDRSIZE, - dgram+DNS_HDRSIZE, - qu->query_dglen-DNS_HDRSIZE)) - continue; - break; - } - if (!qu) { - if (ads->iflags & adns_if_debug) { - adns__vbuf_init(&tempvb); - adns__debug(ads,serv,0,"reply not found, id %02x, query owner %s", - id, adns__diag_domain(ads,serv,0,&tempvb,dgram,dglen,DNS_HDRSIZE)); - adns__vbuf_free(&tempvb); + + qu= 0; + /* See if we can find the relevant query, or leave qu=0 otherwise ... */ + + if (qdcount == 1) { + for (qu= viatcp ? ads->tcpw.head : ads->udpw.head; qu; qu= nqu) { + nqu= qu->next; + if (qu->id != id) continue; + if (dglen < qu->query_dglen) continue; + if (memcmp(qu->query_dgram+DNS_HDRSIZE, + dgram+DNS_HDRSIZE, + qu->query_dglen-DNS_HDRSIZE)) + continue; + if (viatcp) { + assert(qu->state == query_tcpw); + } else { + assert(qu->state == query_tosend); + if (!(qu->udpsent & (1<tcpw,qu); + else LIST_UNLINK(ads->udpw,qu); } - return; } - anstart= qu->query_dglen; - arstart= -1; - - LIST_UNLINK(ads->timew,qu); - /* We're definitely going to do something with this query now */ + /* If we're going to ignore the packet, we return as soon as we have + * failed the query (if any) and printed the warning message (if + * any). + */ switch (rcode) { case rcode_noerror: case rcode_nxdomain: break; case rcode_formaterror: - adns__warn(ads,serv,qu,"server cannot understand our query (Format Error)"); - adns__query_fail(qu,adns_s_rcodeformaterror); + adns__warn(ads,serv,qu,"server cannot understand our query" + " (Format Error)"); + if (qu) adns__query_fail(qu,adns_s_rcodeformaterror); return; case rcode_servfail: - adns__query_fail(qu,adns_s_rcodeservfail); + if (qu) adns__query_fail(qu,adns_s_rcodeservfail); + else adns__debug(ads,serv,qu,"server failure on unidentifiable query"); return; case rcode_notimp: adns__warn(ads,serv,qu,"server claims not to implement our query"); - adns__query_fail(qu,adns_s_rcodenotimplemented); + if (qu) adns__query_fail(qu,adns_s_rcodenotimplemented); return; case rcode_refused: - adns__warn(ads,serv,qu,"server refused our query"); - adns__query_fail(qu,adns_s_rcoderefused); + adns__debug(ads,serv,qu,"server refused our query"); + if (qu) adns__query_fail(qu,adns_s_rcoderefused); return; default: adns__warn(ads,serv,qu,"server gave unknown response code %d",rcode); - adns__query_fail(qu,adns_s_rcodeunknown); + if (qu) adns__query_fail(qu,adns_s_rcodeunknown); return; } + if (!qu) { + if (!qdcount) { + adns__diag(ads,serv,0,"server sent reply without quoting our question"); + } else if (qdcount>1) { + adns__diag(ads,serv,0,"server claimed to answer %d" + " questions with one message", qdcount); + } else if (ads->iflags & adns_if_debug) { + adns__vbuf_init(&tempvb); + adns__debug(ads,serv,0,"reply not found, id %02x, query owner %s", + id, adns__diag_domain(ads,serv,0,&tempvb, + dgram,dglen,DNS_HDRSIZE)); + adns__vbuf_free(&tempvb); + } + return; + } + + /* We're definitely going to do something with this packet and this + * query now. */ + + anstart= qu->query_dglen; + arstart= -1; + /* Now, take a look at the answer section, and see if it is complete. * If it has any CNAMEs we stuff them in the answer. */ @@ -145,33 +173,49 @@ void adns__procdgram(adns_state ads, const byte *dgram, int dglen, if (rrtype == -1) goto x_truncated; if (rrclass != DNS_CLASS_IN) { - adns__diag(ads,serv,qu,"ignoring answer RR with wrong class %d (expected IN=%d)", - rrclass,DNS_CLASS_IN); + adns__diag(ads,serv,qu,"ignoring answer RR with wrong class %d" + " (expected IN=%d)", rrclass,DNS_CLASS_IN); continue; } if (!ownermatched) { if (ads->iflags & adns_if_debug) { adns__debug(ads,serv,qu,"ignoring RR with an unexpected owner %s", - adns__diag_domain(ads,serv,qu, &qu->vb, dgram,dglen,rrstart)); + adns__diag_domain(ads,serv,qu, &qu->vb, + dgram,dglen,rrstart)); } continue; } if (rrtype == adns_r_cname && - (qu->typei->type & adns__rrt_typemask) != adns_r_cname) { + (qu->answer->type & adns_rrt_typemask) != adns_r_cname) { if (qu->flags & adns_qf_cname_forbid) { adns__query_fail(qu,adns_s_prohibitedcname); return; - } else if (!qu->cname_dgram) { /* Ignore second and subsequent CNAMEs */ + } else if (qu->cname_dgram) { /* Ignore second and subsequent CNAME(s) */ + adns__debug(ads,serv,qu,"allegedly canonical name %s" + " is actually alias for %s", qu->answer->cname, + adns__diag_domain(ads,serv,qu, &qu->vb, + dgram,dglen,rdstart)); + adns__query_fail(qu,adns_s_prohibitedcname); + return; + } else if (wantedrrs) { /* Ignore CNAME(s) after RR(s). */ + adns__debug(ads,serv,qu,"ignoring CNAME (to %s) coexisting with RR", + adns__diag_domain(ads,serv,qu, &qu->vb, + dgram,dglen,rdstart)); + } else { qu->cname_begin= rdstart; qu->cname_dglen= dglen; st= adns__parse_domain(ads,serv,qu, &qu->vb, - qu->flags & adns_qf_quoteok_cname ? pdf_quoteok : 0, + qu->flags & adns_qf_quotefail_cname + ? 0 : pdf_quoteok, dgram,dglen, &rdstart,rdstart+rdlength); if (!qu->vb.used) goto x_truncated; if (st) { adns__query_fail(qu,st); return; } l= strlen(qu->vb.buf)+1; - qu->answer->cname= adns__alloc_interim(qu,l); - if (!qu->answer->cname) { adns__query_fail(qu,adns_s_nomemory); return; } + qu->answer->cname= adns__alloc_preserved(qu,l); + if (!qu->answer->cname) { + adns__query_fail(qu,adns_s_nomemory); + return; + } qu->cname_dgram= adns__alloc_mine(qu,dglen); memcpy(qu->cname_dgram,dgram,dglen); @@ -184,15 +228,12 @@ void adns__procdgram(adns_state ads, const byte *dgram, int dglen, * TCP. If there is no truncation we can use the whole answer if * it contains the relevant info. */ - } else { - adns__debug(ads,serv,qu,"ignoring duplicate CNAME (%s, as well as %s)", - adns__diag_domain(ads,serv,qu, &qu->vb, dgram,dglen,rdstart), - qu->answer->cname); } - } else if (rrtype == (qu->typei->type & adns__rrt_typemask)) { + } else if (rrtype == (qu->answer->type & adns_rrt_typemask)) { wantedrrs++; } else { - adns__debug(ads,serv,qu,"ignoring answer RR with irrelevant type %d",rrtype); + adns__debug(ads,serv,qu,"ignoring answer RR" + " with irrelevant type %d",rrtype); } } @@ -204,9 +245,11 @@ void adns__procdgram(adns_state ads, const byte *dgram, int dglen, nsstart= cbyte; if (!wantedrrs) { - /* Oops, NODATA or NXDOMAIN or perhaps a referral (which would be a problem) */ + /* Oops, NODATA or NXDOMAIN or perhaps a referral + * (which would be a problem) */ - /* RFC2308: NODATA has _either_ a SOA _or_ _no_ NS records in authority section */ + /* RFC2308: NODATA has _either_ a SOA _or_ _no_ NS records + * in authority section */ foundsoa= 0; soattl= 0; foundns= 0; for (rri= 0; rriflags & adns_qf_search) { + if (qu->flags & adns_qf_search && !qu->cname_dgram) { adns__search_next(ads,qu,now); } else { adns__query_fail(qu,adns_s_nxdomain); @@ -251,14 +294,17 @@ void adns__procdgram(adns_state ads, const byte *dgram, int dglen, if (cname_here) goto x_restartquery; /* Bloody hell, I thought we asked for recursion ? */ - if (flg_rd) { - adns__diag(ads,serv,qu,"server thinks we didn't ask for recursive lookup"); - } if (!flg_ra) { - adns__diag(ads,serv,qu,"server is not willing to do recursive lookups for us"); + adns__diag(ads,serv,qu,"server is not willing" + " to do recursive lookups for us"); adns__query_fail(qu,adns_s_norecurse); } else { - adns__diag(ads,serv,qu,"server claims to do recursion, but gave us a referral"); + if (!flg_rd) + adns__diag(ads,serv,qu,"server thinks" + " we didn't ask for recursive lookup"); + else + adns__debug(ads,serv,qu,"server claims to do recursion," + " but gave us a referral"); adns__query_fail(qu,adns_s_invalidresponse); } return; @@ -267,7 +313,10 @@ void adns__procdgram(adns_state ads, const byte *dgram, int dglen, /* Now, we have some RRs which we wanted. */ qu->answer->rrs.untyped= adns__alloc_interim(qu,qu->typei->rrsz*wantedrrs); - if (!qu->answer->rrs.untyped) { adns__query_fail(qu,adns_s_nomemory); return; } + if (!qu->answer->rrs.untyped) { + adns__query_fail(qu,adns_s_nomemory); + return; + } typei= qu->typei; cbyte= anstart; @@ -289,7 +338,7 @@ void adns__procdgram(adns_state ads, const byte *dgram, int dglen, &ownermatched); assert(!st); assert(rrtype != -1); if (rrclass != DNS_CLASS_IN || - rrtype != (qu->typei->type & adns__rrt_typemask) || + rrtype != (qu->answer->type & adns_rrt_typemask) || !ownermatched) continue; adns__update_expires(qu,ttl,now); @@ -303,11 +352,10 @@ void adns__procdgram(adns_state ads, const byte *dgram, int dglen, /* This may have generated some child queries ... */ if (qu->children.head) { - qu->state= query_child; + qu->state= query_childw; LIST_LINK_TAIL(ads->childw,qu); return; } - adns__query_done(qu); return; @@ -321,11 +369,10 @@ void adns__procdgram(adns_state ads, const byte *dgram, int dglen, qu->flags |= adns_qf_usevc; x_restartquery: - if (qu->cname_dgram) { st= adns__mkquery_frdgram(qu->ads,&qu->vb,&qu->id, - qu->cname_dgram, qu->cname_dglen, qu->cname_begin, - qu->typei->type, qu->flags); + qu->cname_dgram,qu->cname_dglen,qu->cname_begin, + qu->answer->type, qu->flags); if (st) { adns__query_fail(qu,st); return; } newquery= realloc(qu->query_dgram,qu->vb.used); @@ -336,6 +383,8 @@ void adns__procdgram(adns_state ads, const byte *dgram, int dglen, memcpy(newquery,qu->vb.buf,qu->vb.used); } - adns__reset_cnameonly(qu); - adns__query_udp(qu,now); + if (qu->state == query_tcpw) qu->state= query_tosend; + qu->retries= 0; + adns__reset_preserved(qu); + adns__query_send(qu,now); }