void adns__procdgram(adns_state ads, const byte *dgram, int dglen, 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; int rrtype, rrclass, rdlength, rdstart; int anstart, nsstart, arstart; int ownermatched, l, nrrs; unsigned long ttl, soattl; const typeinfo *typei; adns_query qu, nqu; dns_rcode rcode; adns_status st; vbuf tempvb; byte *newquery, *rrsdata; parseinfo pai; if (dglen<DNS_HDRSIZE) { adns__diag(ads,serv,0,"received datagram too short for message header (%d)",dglen); return; } cbyte= 0; GET_W(cbyte,id); GET_B(cbyte,f1); GET_B(cbyte,f2); GET_W(cbyte,qdcount); GET_W(cbyte,ancount); GET_W(cbyte,nscount); GET_W(cbyte,arcount); assert(cbyte == DNS_HDRSIZE); flg_qr= f1&0x80; opcode= (f1&0x78)>>3; flg_tc= f1&0x02; flg_rd= f1&0x01; flg_ra= f2&0x80; rcode= (f2&0x0f); cname_here= 0; if (!flg_qr) { adns__diag(ads,serv,0,"server sent us a query, not a response"); return; } if (opcode) { adns__diag(ads,serv,0,"server sent us unknown opcode %d (wanted 0=QUERY)",opcode); return; } 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<<serv))) continue; } break; } if (qu) { /* We're definitely going to do something with this query now */ if (viatcp) DLIST_UNLINK(ads->tcpw,qu); else DLIST_UNLINK(ads->udpw,qu); } } /* 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)"); if (qu) adns__query_fail(qu,adns_s_rcodeformaterror); return; case rcode_servfail: 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"); if (qu) adns__query_fail(qu,adns_s_rcodenotimplemented); return; case rcode_refused: 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); 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. */ wantedrrs= 0; cbyte= anstart; for (rri= 0; rri<ancount; rri++) { rrstart= cbyte; st= adns__findrr(qu,serv, dgram,dglen,&cbyte, &rrtype,&rrclass,&ttl, &rdlength,&rdstart, &ownermatched); if (st) { adns__query_fail(qu,st); return; } 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); 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)); } continue; } if (rrtype == adns_r_cname && (qu->typei->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 && ++qu->cname_count >= 2 ) { 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_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_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); memcpy(qu->answer->cname,qu->vb.buf,l); cname_here= 1; adns__update_expires(qu,ttl,now); /* If we find the answer section truncated after this point we restart * the query at the CNAME; if beforehand then we obviously have to use * TCP. If there is no truncation we can use the whole answer if * it contains the relevant info. */ } } else if (rrtype == (qu->typei->type & adns__rrt_typemask)) { wantedrrs++; } else { adns__debug(ads,serv,qu,"ignoring answer RR with irrelevant type %d",rrtype); } } /* We defer handling truncated responses here, in case there was a CNAME * which we could use. */ if (flg_tc) goto x_truncated; nsstart= cbyte; if (!wantedrrs) { /* 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 */ foundsoa= 0; soattl= 0; foundns= 0; for (rri= 0; rri<nscount; rri++) { rrstart= cbyte; st= adns__findrr(qu,serv, dgram,dglen,&cbyte, &rrtype,&rrclass,&ttl, &rdlength,&rdstart, 0); if (st) { adns__query_fail(qu,st); return; } if (rrtype==-1) goto x_truncated; if (rrclass != DNS_CLASS_IN) { adns__diag(ads,serv,qu, "ignoring authority RR with wrong class %d (expected IN=%d)", rrclass,DNS_CLASS_IN); continue; } if (rrtype == adns_r_soa_raw) { foundsoa= 1; soattl= ttl; break; } else if (rrtype == adns_r_ns_raw) { foundns= 1; } } if (rcode == rcode_nxdomain) { /* We still wanted to look for the SOA so we could find the TTL. */ adns__update_expires(qu,soattl,now); if (qu->flags & adns_qf_search) { adns__search_next(ads,qu,now); } else { adns__query_fail(qu,adns_s_nxdomain); } return; } if (foundsoa || !foundns) { /* Aha ! A NODATA response, good. */ adns__update_expires(qu,soattl,now); adns__query_fail(qu,adns_s_nodata); return; } /* Now what ? No relevant answers, no SOA, and at least some NS's. * Looks like a referral. Just one last chance ... if we came across * a CNAME in this datagram then we should probably do our own CNAME * lookup now in the hope that we won't get a referral again. */ if (cname_here) goto x_restartquery; /* Bloody hell, I thought we asked for recursion ? */ if (!flg_ra) { adns__diag(ads,serv,qu,"server is not willing to do recursive lookups for us"); adns__query_fail(qu,adns_s_norecurse); } else { 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; } /* 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; } typei= qu->typei; cbyte= anstart; rrsdata= qu->answer->rrs.bytes; pai.ads= qu->ads; pai.qu= qu; pai.serv= serv; pai.dgram= dgram; pai.dglen= dglen; pai.nsstart= nsstart; pai.nscount= nscount; pai.arcount= arcount; pai.now= now; for (rri=0, nrrs=0; rri<ancount; rri++) { st= adns__findrr(qu,serv, dgram,dglen,&cbyte, &rrtype,&rrclass,&ttl, &rdlength,&rdstart, &ownermatched); assert(!st); assert(rrtype != -1); if (rrclass != DNS_CLASS_IN || rrtype != (qu->typei->type & adns__rrt_typemask) || !ownermatched) continue; adns__update_expires(qu,ttl,now); st= typei->parse(&pai, rdstart,rdstart+rdlength, rrsdata+nrrs*typei->rrsz); if (st) { adns__query_fail(qu,st); return; } if (rdstart==-1) goto x_truncated; nrrs++; } assert(nrrs==wantedrrs); qu->answer->nrrs= nrrs; /* This may have generated some child queries ... */ if (qu->children.head) { qu->state= query_childw; DLIST_LINK_TAIL(ads->childw,qu); return; } adns__query_done(qu); return; x_truncated: if (!flg_tc) { adns__diag(ads,serv,qu,"server sent datagram which points outside itself"); adns__query_fail(qu,adns_s_invalidresponse); return; } 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); if (st) { adns__query_fail(qu,st); return; } newquery= MyRealloc(qu->query_dgram,qu->vb.used); if (!newquery) { adns__query_fail(qu,adns_s_nomemory); return; } qu->query_dgram= newquery; qu->query_dglen= qu->vb.used; memcpy(newquery,qu->vb.buf,qu->vb.used); } if (qu->state == query_tcpw) qu->state= query_tosend; qu->retries= 0; adns__reset_preserved(qu); adns__query_send(qu,now); }
int main(int argc, char *argv[]) { myelmt_t *newelmt; myelmt_t *elmt; myctx_t *ctx; int i; int action; int j; int r; ctx = malloc(sizeof (myctx_t)); DLIST_INIT(ctx, headlist); DLIST_INIT(ctx, taillist); for ( i = 0; i < 50000000 ; i++) { action = rand_range(0, 9); printf("action: %i\n", action); switch (action) { case ACTION_INSHEAD: elmt = malloc(sizeof (myelmt_t)); elmt->blah = i; DLIST_INS_HEAD(ctx, headlist, elmt); break; case ACTION_INSTAIL: elmt = malloc(sizeof (myelmt_t)); elmt->blah = i; DLIST_INS_TAIL(ctx, headlist, elmt); break; case ACTION_INSNEXT: printf("* insert after a random element.\n"); newelmt = malloc(sizeof (myelmt_t)); newelmt->blah = i; if (DLIST_IS_EMPTY(ctx, headlist)) { printf(" list is empty\n"); DLIST_INS_HEAD(ctx, headlist, newelmt); continue ; } r = rand_range(0, DLIST_COUNT(ctx, headlist)); for (j = 0, elmt = DLIST_HEAD(ctx, headlist) ; j < r; j++, elmt = DLIST_NEXT(headlist, elmt)) ; DLIST_INS_NEXT(ctx, headlist, elmt, newelmt); break; case ACTION_INSPREV: printf("* insert before a random element.\n"); newelmt = malloc(sizeof (myelmt_t)); newelmt->blah = i; if (DLIST_IS_EMPTY(ctx, headlist)) { printf(" list is empty\n"); DLIST_INS_HEAD(ctx, headlist, newelmt); continue ; } r = rand_range(0, DLIST_COUNT(ctx, headlist)); for (j = 0, elmt = DLIST_HEAD(ctx, headlist) ; j < r; j++, elmt = DLIST_NEXT(headlist, elmt)) ; DLIST_INS_PREV(ctx, headlist, elmt, newelmt); break; case ACTION_UNLINK1: case ACTION_UNLINK2: case ACTION_UNLINK3: case ACTION_UNLINK4: case ACTION_UNLINK5: printf("* unlink a random element.\n"); if (DLIST_IS_EMPTY(ctx, headlist)) { printf(" list is empty\n"); continue ; } r = rand_range(0, DLIST_COUNT(ctx, headlist)); for (j = 0, elmt = DLIST_HEAD(ctx, headlist) ; j < r; j++, elmt = DLIST_NEXT(headlist, elmt)) ; DLIST_UNLINK(ctx, headlist, elmt); free(elmt); break; case ACTION_SHOWLIST: printf("* show list content: (%i elements)\n", DLIST_COUNT(ctx, headlist)); if ( DLIST_IS_EMPTY(ctx, headlist) ) { printf(" list is empty\n"); } else { j = 0; DLIST_FOR_EACH(elmt, ctx, headlist) { printf(" elmt %i: val: %i\n", j, elmt->blah); j++; } } break; } }