[adns] / src / reply.c

/*
 * reply.c
 * - main handling and parsing routine for received datagrams
 */
/*
 *  This file is part of adns, which is Copyright (C) 1997-1999 Ian Jackson
 *  
 *  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
 *  the Free Software Foundation; either version 2, or (at your option)
 *  any later version.
 *  
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *  
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software Foundation,
 *  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 
 */

#include <stdlib.h>

#include "internal.h"
    
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;
  }
  if (!qdcount) {
    adns__diag(ads,serv,0,"server sent reply without quoting our question");
    return;
  } else if (qdcount>1) {
    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;
    if (viatcp) {
      if (qu->state != query_tcpsent) continue;
    } else {
      if (qu->state != query_tosend) continue;
      if (!(qu->udpsent & (1<<serv))) 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);
    }
    return;
  }
  anstart= qu->query_dglen;
  arstart= -1;

  LIST_UNLINK(ads->timew,qu);
  /* We're definitely going to do something with this query now */
  
  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);
    return;
  case rcode_servfail:
    adns__query_fail(qu,adns_s_rcodeservfail);
    return;
  case rcode_notimp:
    adns__warn(ads,serv,qu,"server claims not to implement our query");
    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);
    return;
  default:
    adns__warn(ads,serv,qu,"server gave unknown response code %d",rcode);
    adns__query_fail(qu,adns_s_rcodeunknown);
    return;
  }

  /* 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) { /* 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,
			       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_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__query_fail(qu,adns_s_norecurse);
    } else {
      adns__diag(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_child;
    LIST_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= realloc(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_tcpsent) qu->state= query_tosend;
  adns__reset_preserved(qu);
  adns__query_send(qu,now);
}
Commit	Line	Data
98db6da3	1	/*
	2	* reply.c
	3	* - main handling and parsing routine for received datagrams
	4	*/
	5	/*
3ff64957	6	* This file is part of adns, which is Copyright (C) 1997-1999 Ian Jackson
98db6da3	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; either version 2, or (at your option)
	11	* any later version.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to the Free Software Foundation,
	20	* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	21	*/
d05cc330	22
f2ad23ee	23	#include <stdlib.h>
d05cc330	24
f2ad23ee	25	#include "internal.h"
54ed1d64	26
5c596e4d	27	void adns__procdgram(adns_state ads, const byte *dgram, int dglen,
c84b7355	28	int serv, int viatcp, struct timeval now) {
1e9efa71	29	int cbyte, rrstart, wantedrrs, rri, foundsoa, foundns, cname_here;
11c8bf9b	30	int id, f1, f2, qdcount, ancount, nscount, arcount;
11c8bf9b	31	int flg_ra, flg_rd, flg_tc, flg_qr, opcode;
f2ad23ee	32	int rrtype, rrclass, rdlength, rdstart;
5c596e4d	33	int anstart, nsstart, arstart;
f318f883	34	int ownermatched, l, nrrs;
2c7b101b	35	unsigned long ttl, soattl;
f2ad23ee	36	const typeinfo *typei;
5c596e4d	37	adns_query qu, nqu;
5c596e4d	38	dns_rcode rcode;
54ed1d64	39	adns_status st;
1e9efa71	40	vbuf tempvb;
f2ad23ee	41	byte newquery, rrsdata;
26eb6bdc	42	parseinfo pai;
168e26fe	43
5c596e4d	44	if (dglen<DNS_HDRSIZE) {
11c8bf9b	45	adns__diag(ads,serv,0,"received datagram too short for message header (%d)",dglen);
168e26fe	46	return;
168e26fe	47	}
9a2b67d4	48	cbyte= 0;
54ed1d64	49	GET_W(cbyte,id);
	50	GET_B(cbyte,f1);
	51	GET_B(cbyte,f2);
	52	GET_W(cbyte,qdcount);
	53	GET_W(cbyte,ancount);
	54	GET_W(cbyte,nscount);
	55	GET_W(cbyte,arcount);
5c596e4d	56	assert(cbyte == DNS_HDRSIZE);
168e26fe	57
7f702335	58	flg_qr= f1&0x80;
7f702335	59	opcode= (f1&0x78)>>3;
f2ad23ee	60	flg_tc= f1&0x02;
7f702335	61	flg_rd= f1&0x01;
8312a1c2	62	flg_ra= f2&0x80;
1e9efa71	63	rcode= (f2&0x0f);
8312a1c2	64
1e9efa71	65	cname_here= 0;
1e9efa71	66
9a2b67d4	67	if (!flg_qr) {
11c8bf9b	68	adns__diag(ads,serv,0,"server sent us a query, not a response");
168e26fe	69	return;
168e26fe	70	}
7f702335	71	if (opcode) {
11c8bf9b	72	adns__diag(ads,serv,0,"server sent us unknown opcode %d (wanted 0=QUERY)",opcode);
168e26fe	73	return;
	74	}
	75	if (!qdcount) {
11c8bf9b	76	adns__diag(ads,serv,0,"server sent reply without quoting our question");
168e26fe	77	return;
168e26fe	78	} else if (qdcount>1) {
11c8bf9b	79	adns__diag(ads,serv,0,"server claimed to answer %d questions with one message",
168e26fe	80	qdcount);
	81	return;
	82	}
5c596e4d	83	for (qu= ads->timew.head; qu; qu= nqu) {
168e26fe	84	nqu= qu->next;
168e26fe	85	if (qu->id != id) continue;
11c8bf9b	86	if (dglen < qu->query_dglen) continue;
	87	if (memcmp(qu->query_dgram+DNS_HDRSIZE,
	88	dgram+DNS_HDRSIZE,
	89	qu->query_dglen-DNS_HDRSIZE))
54ed1d64	90	continue;
c84b7355	91	if (viatcp) {
	92	if (qu->state != query_tcpsent) continue;
	93	} else {
	94	if (qu->state != query_tosend) continue;
	95	if (!(qu->udpsent & (1<<serv))) continue;
	96	}
168e26fe	97	break;
	98	}
	99	if (!qu) {
1e9efa71	100	if (ads->iflags & adns_if_debug) {
	101	adns__vbuf_init(&tempvb);
	102	adns__debug(ads,serv,0,"reply not found, id %02x, query owner %s",
cd363ffd	103	id, adns__diag_domain(ads,serv,0,&tempvb,dgram,dglen,DNS_HDRSIZE));
1e9efa71	104	adns__vbuf_free(&tempvb);
1e9efa71	105	}
168e26fe	106	return;
168e26fe	107	}
1e9efa71	108	anstart= qu->query_dglen;
f318f883	109	arstart= -1;
5c596e4d	110
	111	LIST_UNLINK(ads->timew,qu);
	112	/* We're definitely going to do something with this query now */
	113
54ed1d64	114	switch (rcode) {
	115	case rcode_noerror:
	116	case rcode_nxdomain:
168e26fe	117	break;
54ed1d64	118	case rcode_formaterror:
7f702335	119	adns__warn(ads,serv,qu,"server cannot understand our query (Format Error)");
9b86645c	120	adns__query_fail(qu,adns_s_rcodeformaterror);
168e26fe	121	return;
5c596e4d	122	case rcode_servfail:
9b86645c	123	adns__query_fail(qu,adns_s_rcodeservfail);
168e26fe	124	return;
54ed1d64	125	case rcode_notimp:
7f702335	126	adns__warn(ads,serv,qu,"server claims not to implement our query");
9b86645c	127	adns__query_fail(qu,adns_s_rcodenotimplemented);
54ed1d64	128	return;
54ed1d64	129	case rcode_refused:
7f702335	130	adns__warn(ads,serv,qu,"server refused our query");
9b86645c	131	adns__query_fail(qu,adns_s_rcoderefused);
54ed1d64	132	return;
54ed1d64	133	default:
7f702335	134	adns__warn(ads,serv,qu,"server gave unknown response code %d",rcode);
9b86645c	135	adns__query_fail(qu,adns_s_rcodeunknown);
54ed1d64	136	return;
	137	}
	138
	139	/* Now, take a look at the answer section, and see if it is complete.
	140	* If it has any CNAMEs we stuff them in the answer.
	141	*/
	142	wantedrrs= 0;
1e9efa71	143	cbyte= anstart;
54ed1d64	144	for (rri= 0; rri<ancount; rri++) {
54ed1d64	145	rrstart= cbyte;
11c8bf9b	146	st= adns__findrr(qu,serv, dgram,dglen,&cbyte,
2c7b101b	147	&rrtype,&rrclass,&ttl, &rdlength,&rdstart,
11c8bf9b	148	&ownermatched);
1e9efa71	149	if (st) { adns__query_fail(qu,st); return; }
8312a1c2	150	if (rrtype == -1) goto x_truncated;
8312a1c2	151
54ed1d64	152	if (rrclass != DNS_CLASS_IN) {
7f702335	153	adns__diag(ads,serv,qu,"ignoring answer RR with wrong class %d (expected IN=%d)",
54ed1d64	154	rrclass,DNS_CLASS_IN);
	155	continue;
	156	}
8312a1c2	157	if (!ownermatched) {
5c596e4d	158	if (ads->iflags & adns_if_debug) {
7f702335	159	adns__debug(ads,serv,qu,"ignoring RR with an unexpected owner %s",
cd363ffd	160	adns__diag_domain(ads,serv,qu, &qu->vb, dgram,dglen,rrstart));
8312a1c2	161	}
54ed1d64	162	continue;
54ed1d64	163	}
940c3875	164	if (rrtype == adns_r_cname &&
7f702335	165	(qu->typei->type & adns__rrt_typemask) != adns_r_cname) {
59fbb06a	166	if (qu->flags & adns_qf_cname_forbid) {
	167	adns__query_fail(qu,adns_s_prohibitedcname);
	168	return;
125de2a9	169	} else if (qu->cname_dgram) { /* Ignore second and subsequent CNAME(s) */
9dbde8ca	170	adns__debug(ads,serv,qu,"allegedly canonical name %s is actually alias for %s",
	171	qu->answer->cname,
	172	adns__diag_domain(ads,serv,qu, &qu->vb, dgram,dglen,rdstart));
	173	adns__query_fail(qu,adns_s_prohibitedcname);
	174	return;
125de2a9	175	} else if (wantedrrs) { /* Ignore CNAME(s) after RR(s). */
	176	adns__debug(ads,serv,qu,"ignoring CNAME (to %s) coexisting with RR",
	177	adns__diag_domain(ads,serv,qu, &qu->vb, dgram,dglen,rdstart));
	178	} else {
7f702335	179	qu->cname_begin= rdstart;
7f702335	180	qu->cname_dglen= dglen;
cd363ffd	181	st= adns__parse_domain(ads,serv,qu, &qu->vb,
cd363ffd	182	qu->flags & adns_qf_quoteok_cname ? pdf_quoteok : 0,
7f702335	183	dgram,dglen, &rdstart,rdstart+rdlength);
11c8bf9b	184	if (!qu->vb.used) goto x_truncated;
	185	if (st) { adns__query_fail(qu,st); return; }
	186	l= strlen(qu->vb.buf)+1;
1be24aef	187	qu->answer->cname= adns__alloc_preserved(qu,l);
9b86645c	188	if (!qu->answer->cname) { adns__query_fail(qu,adns_s_nomemory); return; }
f2ad23ee	189
	190	qu->cname_dgram= adns__alloc_mine(qu,dglen);
	191	memcpy(qu->cname_dgram,dgram,dglen);
	192
11c8bf9b	193	memcpy(qu->answer->cname,qu->vb.buf,l);
1e9efa71	194	cname_here= 1;
2c7b101b	195	adns__update_expires(qu,ttl,now);
7f702335	196	/* If we find the answer section truncated after this point we restart
	197	* the query at the CNAME; if beforehand then we obviously have to use
	198	* TCP. If there is no truncation we can use the whole answer if
	199	* it contains the relevant info.
	200	*/
7f702335	201	}
5c596e4d	202	} else if (rrtype == (qu->typei->type & adns__rrt_typemask)) {
54ed1d64	203	wantedrrs++;
54ed1d64	204	} else {
7f702335	205	adns__debug(ads,serv,qu,"ignoring answer RR with irrelevant type %d",rrtype);
54ed1d64	206	}
	207	}
	208
f2ad23ee	209	/* We defer handling truncated responses here, in case there was a CNAME
	210	* which we could use.
	211	*/
	212	if (flg_tc) goto x_truncated;
	213
54ed1d64	214	nsstart= cbyte;
	215
	216	if (!wantedrrs) {
	217	/* Oops, NODATA or NXDOMAIN or perhaps a referral (which would be a problem) */
54ed1d64	218
54ed1d64	219	/* RFC2308: NODATA has _either_ a SOA _or_ _no_ NS records in authority section */
2c7b101b	220	foundsoa= 0; soattl= 0; foundns= 0;
54ed1d64	221	for (rri= 0; rri<nscount; rri++) {
8312a1c2	222	rrstart= cbyte;
11c8bf9b	223	st= adns__findrr(qu,serv, dgram,dglen,&cbyte,
2c7b101b	224	&rrtype,&rrclass,&ttl, &rdlength,&rdstart, 0);
11c8bf9b	225	if (st) { adns__query_fail(qu,st); return; }
8312a1c2	226	if (rrtype==-1) goto x_truncated;
8312a1c2	227	if (rrclass != DNS_CLASS_IN) {
7f702335	228	adns__diag(ads,serv,qu,
7f702335	229	"ignoring authority RR with wrong class %d (expected IN=%d)",
8312a1c2	230	rrclass,DNS_CLASS_IN);
	231	continue;
	232	}
2c7b101b	233	if (rrtype == adns_r_soa_raw) { foundsoa= 1; soattl= ttl; break; }
8312a1c2	234	else if (rrtype == adns_r_ns_raw) { foundns= 1; }
54ed1d64	235	}
2c7b101b	236
	237	if (rcode == rcode_nxdomain) {
	238	/* We still wanted to look for the SOA so we could find the TTL. */
	239	adns__update_expires(qu,soattl,now);
7e6a84a1	240
	241	if (qu->flags & adns_qf_search) {
	242	adns__search_next(ads,qu,now);
	243	} else {
	244	adns__query_fail(qu,adns_s_nxdomain);
	245	}
2c7b101b	246	return;
2c7b101b	247	}
8312a1c2	248
	249	if (foundsoa \|\| !foundns) {
	250	/* Aha ! A NODATA response, good. */
2c7b101b	251	adns__update_expires(qu,soattl,now);
11c8bf9b	252	adns__query_fail(qu,adns_s_nodata);
8312a1c2	253	return;
	254	}
	255
	256	/* Now what ? No relevant answers, no SOA, and at least some NS's.
	257	* Looks like a referral. Just one last chance ... if we came across
7f702335	258	* a CNAME in this datagram then we should probably do our own CNAME
7f702335	259	* lookup now in the hope that we won't get a referral again.
8312a1c2	260	*/
f2ad23ee	261	if (cname_here) goto x_restartquery;
8312a1c2	262
8312a1c2	263	/* Bloody hell, I thought we asked for recursion ? */
7f702335	264	if (flg_rd) {
	265	adns__diag(ads,serv,qu,"server thinks we didn't ask for recursive lookup");
	266	}
8312a1c2	267	if (!flg_ra) {
7f702335	268	adns__diag(ads,serv,qu,"server is not willing to do recursive lookups for us");
11c8bf9b	269	adns__query_fail(qu,adns_s_norecurse);
7f702335	270	} else {
7f702335	271	adns__diag(ads,serv,qu,"server claims to do recursion, but gave us a referral");
9b86645c	272	adns__query_fail(qu,adns_s_invalidresponse);
8312a1c2	273	}
54ed1d64	274	return;
	275	}
	276
8312a1c2	277	/* Now, we have some RRs which we wanted. */
54ed1d64	278
11c8bf9b	279	qu->answer->rrs.untyped= adns__alloc_interim(qu,qu->typei->rrsz*wantedrrs);
9b86645c	280	if (!qu->answer->rrs.untyped) { adns__query_fail(qu,adns_s_nomemory); return; }
5c596e4d	281
f2ad23ee	282	typei= qu->typei;
5c596e4d	283	cbyte= anstart;
f2ad23ee	284	rrsdata= qu->answer->rrs.bytes;
26eb6bdc	285
	286	pai.ads= qu->ads;
	287	pai.qu= qu;
	288	pai.serv= serv;
	289	pai.dgram= dgram;
	290	pai.dglen= dglen;
	291	pai.nsstart= nsstart;
	292	pai.nscount= nscount;
	293	pai.arcount= arcount;
ba1ddf08	294	pai.now= now;
26eb6bdc	295
26eb6bdc	296	for (rri=0, nrrs=0; rri<ancount; rri++) {
11c8bf9b	297	st= adns__findrr(qu,serv, dgram,dglen,&cbyte,
2c7b101b	298	&rrtype,&rrclass,&ttl, &rdlength,&rdstart,
11c8bf9b	299	&ownermatched);
5c596e4d	300	assert(!st); assert(rrtype != -1);
5c596e4d	301	if (rrclass != DNS_CLASS_IN \|\|
7f702335	302	rrtype != (qu->typei->type & adns__rrt_typemask) \|\|
7f702335	303	!ownermatched)
5c596e4d	304	continue;
2c7b101b	305	adns__update_expires(qu,ttl,now);
26eb6bdc	306	st= typei->parse(&pai, rdstart,rdstart+rdlength, rrsdata+nrrs*typei->rrsz);
11c8bf9b	307	if (st) { adns__query_fail(qu,st); return; }
7f702335	308	if (rdstart==-1) goto x_truncated;
f2ad23ee	309	nrrs++;
5c596e4d	310	}
f2ad23ee	311	assert(nrrs==wantedrrs);
f2ad23ee	312	qu->answer->nrrs= nrrs;
54ed1d64	313
5c596e4d	314	/* This may have generated some child queries ... */
	315	if (qu->children.head) {
	316	qu->state= query_child;
	317	LIST_LINK_TAIL(ads->childw,qu);
	318	return;
54ed1d64	319	}
11c8bf9b	320	adns__query_done(qu);
5c596e4d	321	return;
8312a1c2	322
98db6da3	323	x_truncated:
f2ad23ee	324
5c596e4d	325	if (!flg_tc) {
7f702335	326	adns__diag(ads,serv,qu,"server sent datagram which points outside itself");
9b86645c	327	adns__query_fail(qu,adns_s_invalidresponse);
5c596e4d	328	return;
5c596e4d	329	}
5c596e4d	330	qu->flags \|= adns_qf_usevc;
f2ad23ee	331
f2ad23ee	332	x_restartquery:
f2ad23ee	333	if (qu->cname_dgram) {
	334	st= adns__mkquery_frdgram(qu->ads,&qu->vb,&qu->id,
	335	qu->cname_dgram, qu->cname_dglen, qu->cname_begin,
	336	qu->typei->type, qu->flags);
	337	if (st) { adns__query_fail(qu,st); return; }
	338
	339	newquery= realloc(qu->query_dgram,qu->vb.used);
9b86645c	340	if (!newquery) { adns__query_fail(qu,adns_s_nomemory); return; }
f2ad23ee	341
	342	qu->query_dgram= newquery;
	343	qu->query_dglen= qu->vb.used;
	344	memcpy(newquery,qu->vb.buf,qu->vb.used);
	345	}
	346
24d52b13	347	if (qu->state == query_tcpsent) qu->state= query_tosend;
1be24aef	348	adns__reset_preserved(qu);
24d52b13	349	adns__query_send(qu,now);
5c596e4d	350	}