Reentrancy: Introduce adns__cancel

[adns] / src / query.c

diff --git a/src/query.c b/src/query.c
index bd7af8a5fcecaf52e6fd14dfe4172ddb0fe96ada..08085342283a8faa5537316270b156ff99ac482b 100644 (file)
--- a/src/query.c
+++ b/src/query.c
@@ -1,187 +1,661 @@
-/**/
+/*
+ * query.c
+ * - overall query management (allocation, completion)
+ * - per-query memory management
+ * - query submission and cancellation (user-visible and internal)
+ */
+/*
+ *  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
+ *  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 "internal.h"
 
 
 #include "internal.h"
 

-adns_status adns__mkquery(adns_state ads, const char *owner, int ol, int id,
-                         adns_rrtype type, adns_queryflags flags) {
-  /* Assembles a query packet in ads->rqbuf. */
-  int ll, c, nlabs;
-  unsigned char label[255], *rqp;
-  const char *p, *pe;
-
-#define MKQUERY_ADDB(b) *rqp++= (b)
-#define MKQUERY_ADDW(w) (MKQUERY_ADDB(((w)>>8)&0x0ff), MKQUERY_ADDB((w)&0x0ff))
-
-  if (!vbuf_ensure(&ads->rqbuf,12+strlen(owner)+3)) return adns_s_nolocalmem;
-  rqp= ads->rqbuf.buf;
-
-  MKQUERY_ADDW(id);
-  MKQUERY_ADDB(0x01); /* QR=Q(0), OPCODE=QUERY(0000), !AA, !TC, RD */
-  MKQUERY_ADDB(0x00); /* !RA, Z=000, RCODE=NOERROR(0000) */
-  MKQUERY_ADDW(1); /* QDCOUNT=1 */
-  MKQUERY_ADDW(0); /* ANCOUNT=0 */
-  MKQUERY_ADDW(0); /* NSCOUNT=0 */
-  MKQUERY_ADDW(0); /* ARCOUNT=0 */
-  p= owner; pe= owner+ol;
-  nlabs= 0;
-  if (!*p) return adns_s_invaliddomain;
-  do {
-    ll= 0;
-    while (p!=pe && (c= *p++)!='.') {
-      if (c=='\\') {
-       if (!(flags & adns_f_anyquote)) return adns_s_invaliddomain;
-       if (ctype_digit(p[0])) {
-         if (ctype_digit(p[1]) && ctype_digit(p[2])) {
-           c= (*p++ - '0')*100 + (*p++ - '0')*10 + (*p++ - '0');
-           if (c >= 256) return adns_s_invaliddomain;
-         } else {
-           return adns_s_invaliddomain;
-         }
-       } else if (!(c= *p++)) {
-         return adns_s_invaliddomain;
-       }
-      }
-      if (!(flags & adns_f_anyquote)) {
-       if (ctype_digit(c) || c == '-') {
-         if (!ll) return adns_s_invaliddomain;
-       } else if ((c < 'a' || c > 'z') && (c < 'A' && c > 'Z')) {
-         return adns_s_invaliddomain;
-       }
-      }
-      if (ll == sizeof(label)) return adns_s_invaliddomain;
-      label[ll++]= c;
-    }
-    if (!ll) return adns_s_invaliddomain;
-    if (nlabs++ > 63) return adns_s_invaliddomain;
-    MKQUERY_ADDB(ll);
-    memcpy(rqp,label,ll); rqp+= ll;
-  } while (p!=pe);
-
-  MKQUERY_ADDB(0);
-  MKQUERY_ADDW(type & adns__rrt_typemask); /* QTYPE */
-  MKQUERY_ADDW(1); /* QCLASS=IN */
-
-  ads->rqbuf.used= rqp - ads->rqbuf.used;
-  assert(ads->rqbuf.used < ads->rqbuf.avail);
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include <sys/time.h>
+
+#include "internal.h"
+
+static adns_query query_alloc(adns_state ads,
+                             const typeinfo *typei, adns_rrtype type,
+                             adns_queryflags flags, struct timeval now) {
+  /* Allocate a virgin query and return it. */
+  adns_query qu;

   
   

-  return adns_s_ok;
+  qu= malloc(sizeof(*qu));  if (!qu) return 0;
+  qu->answer= malloc(sizeof(*qu->answer));
+  if (!qu->answer) { free(qu); return 0; }
+  
+  qu->ads= ads;
+  qu->state= query_tosend;
+  qu->back= qu->next= qu->parent= 0;
+  LIST_INIT(qu->children);
+  LINK_INIT(qu->siblings);
+  LIST_INIT(qu->allocations);
+  qu->interim_allocd= 0;
+  qu->preserved_allocd= 0;
+  qu->final_allocspace= 0;
+
+  qu->typei= typei;
+  qu->query_dgram= 0;
+  qu->query_dglen= 0;
+  adns__vbuf_init(&qu->vb);
+
+  qu->cname_dgram= 0;
+  qu->cname_dglen= qu->cname_begin= 0;
+
+  adns__vbuf_init(&qu->search_vb);
+  qu->search_origlen= qu->search_pos= qu->search_doneabs= 0;
+
+  qu->id= -2; /* will be overwritten with real id before we leave adns */
+  qu->flags= flags;
+  qu->retries= 0;
+  qu->udpnextserver= 0;
+  qu->udpsent= 0;
+  timerclear(&qu->timeout);
+  qu->expires= now.tv_sec + MAXTTLBELIEVE;
+
+  memset(&qu->ctx,0,sizeof(qu->ctx));
+
+  qu->answer->status= adns_s_ok;
+  qu->answer->cname= qu->answer->owner= 0;
+  qu->answer->type= type;
+  qu->answer->expires= -1;
+  qu->answer->nrrs= 0;
+  qu->answer->rrs.untyped= 0;
+  qu->answer->rrsz= typei->getrrsz(typei,type);
+
+  return qu;

 }
 
 }
 

-void adns__query_tcp(adns_state ads, adns_query qu) {
-  /* Query must be in state tcpwait/timew; it will be moved to a new state
-   * if possible and no further processing can be done on it for now.
-   * (Resulting state is one of tcpwait/timew (if server not connected),
-   *  tcpsent/timew, child/childw or done/output.)
-   *
-   * adns__tcp_tryconnect should already have been called - _tcp
-   * will only use an existing connection (if there is one), which it
-   * may break.  If the conn list lost then the caller is responsible for any
-   * reestablishment and retry.
+static void query_submit(adns_state ads, adns_query qu,
+                        const typeinfo *typei, vbuf *qumsg_vb, int id,
+                        adns_queryflags flags, struct timeval now) {
+  /* Fills in the query message in for a previously-allocated query,
+   * and submits it.  Cannot fail.  Takes over the memory for qumsg_vb.

    */
    */

-  unsigned char length[2];
-  struct iovec iov[2];

 
 

-  if (ads->tcpstate != server_ok) return;
+  qu->vb= *qumsg_vb;
+  adns__vbuf_init(qumsg_vb);

 
 

-  length[0]= (qu->querylen&0x0ff00U) >>8;
-  length[1]= (qu->querylen&0x0ff);
+  qu->query_dgram= malloc(qu->vb.used);
+  if (!qu->query_dgram) { adns__query_fail(qu,adns_s_nomemory); return; }

   
   

-  if (!vbuf_ensure(&ads->tcpsend,ads->tcpsend.used+qu->querylen+2)) return;
+  qu->id= id;
+  qu->query_dglen= qu->vb.used;
+  memcpy(qu->query_dgram,qu->vb.buf,qu->vb.used);
+
+  typei->query_send(qu,now);
+}
+
+adns_status adns__ckl_hostname(adns_state ads, adns_queryflags flags,
+                              union checklabel_state *cls,
+                              qcontext *ctx, int labnum,
+                              const char *label, int lablen)
+{
+  int i, c;
+
+  if (flags & adns_qf_quoteok_query) return adns_s_ok;
+  for (i=0; i<lablen; i++) {
+    c= label[i];
+    if (c == '-') {
+      if (!i) return adns_s_querydomaininvalid;
+    } else if (!ctype_alpha(c) && !ctype_digit(c)) {
+      return adns_s_querydomaininvalid;
+    }
+  }
+  return adns_s_ok;
+}
+
+static adns_status check_domain_name(adns_state ads, adns_queryflags flags,
+                                    qcontext *ctx, const typeinfo *typei,
+                                    const byte *dgram, int dglen)
+{
+  findlabel_state fls;
+  adns_status err;
+  int labnum= 0, labstart, lablen;
+  union checklabel_state cls;
+
+  adns__findlabel_start(&fls,ads, -1,0, dgram,dglen,dglen, DNS_HDRSIZE,0);
+  do {
+    err= adns__findlabel_next(&fls, &lablen,&labstart);
+    assert(!err); assert(lablen >= 0);
+    err= typei->checklabel(ads,flags, &cls,ctx,
+                          labnum++, dgram+labstart,lablen);
+    if (err) return err;
+  } while (lablen);
+  return adns_s_ok;
+}
+
+adns_status adns__internal_submit(adns_state ads, adns_query *query_r,
+                                 adns_query parent,
+                                 const typeinfo *typei, adns_rrtype type,
+                                 vbuf *qumsg_vb, int id,
+                                 adns_queryflags flags, struct timeval now,
+                                 qcontext *ctx) {
+  adns_query qu;
+  adns_status err;
+
+  err= check_domain_name(ads, flags,ctx,typei, qumsg_vb->buf,qumsg_vb->used);
+  if (err) goto x_err;
+  qu= query_alloc(ads,typei,type,flags,now);
+  if (!qu) { err = adns_s_nomemory; goto x_err; }
+  *query_r= qu;
+
+  qu->parent= parent;
+  LIST_LINK_TAIL_PART(parent->children,qu,siblings.);
+  memcpy(&qu->ctx,ctx,sizeof(qu->ctx));
+  query_submit(ads,qu, typei,qumsg_vb,id,flags,now);
+  
+  return adns_s_ok;
+
+x_err:
+  adns__vbuf_free(qumsg_vb);
+  return err;
+}
+
+static void query_simple(adns_state ads, adns_query qu,
+                        const char *owner, int ol,
+                        const typeinfo *typei, adns_queryflags flags,
+                        struct timeval now) {
+  vbuf vb_new;
+  int id;
+  adns_status stat;
+
+  stat= adns__mkquery(ads,&qu->vb,&id, owner,ol,
+                     typei,qu->answer->type, flags);
+  if (stat) {
+    if (stat == adns_s_querydomaintoolong && (flags & adns_qf_search)) {
+      adns__search_next(ads,qu,now);
+      return;
+    } else {
+      adns__query_fail(qu,stat);
+      return;
+    }
+  }

 
 

-  timevaladd(&now,TCPMS);
-  qu->timeout= now;
-  qu->senttcpserver= ads->tcpserver;
-  DLIST_LINKTAIL(ads->timew,qu);
+  stat= check_domain_name(ads, flags,&qu->ctx,typei, qu->vb.buf,qu->vb.used);
+  if (stat) { adns__query_fail(qu,stat); return; }

 
 

-  if (ads->opbufused) {
-    wr= 0;
+  vb_new= qu->vb;
+  adns__vbuf_init(&qu->vb);
+  query_submit(ads,qu, typei,&vb_new,id, flags,now);
+}
+
+void adns__search_next(adns_state ads, adns_query qu, struct timeval now) {
+  const char *nextentry;
+  adns_status stat;
+  
+  if (qu->search_doneabs<0) {
+    nextentry= 0;
+    qu->search_doneabs= 1;

   } else {
   } else {

-    iov[0].iovbase= length;
-    iov[0].iov_len= 2;
-    iov[1].iovbase= qu->querymsg;
-    iov[1].iov_len= qu->querylen;
-    wr= writev(ads->tcpsocket,iov,2);
-    if (wr < 0) {
-      if (!(errno == EAGAIN || errno == EINTR || errno == ENOSPC ||
-           errno == ENOBUFS || errno == ENOMEM)) {
-       adns__tcp_broken(ads,"write",strerror(errno));
-       return;
+    if (qu->search_pos >= ads->nsearchlist) {
+      if (qu->search_doneabs) {
+       qu->search_vb.used= qu->search_origlen;
+       stat= adns_s_nxdomain; goto x_fail;
+      } else {
+       nextentry= 0;
+       qu->search_doneabs= 1;

       }
       }

-      wr= 0;
+    } else {
+      nextentry= ads->searchlist[qu->search_pos++];

     }
   }
 
     }
   }
 

-  if (wr<2) {
-    r= vbuf_append(&ads->tcpsend,length,2-wr); assert(r);
-    wr= 0;
-  } esle {
-    wr-= 2;
+  qu->search_vb.used= qu->search_origlen;
+  if (nextentry) {
+    if (!adns__vbuf_append(&qu->search_vb,".",1) ||
+       !adns__vbuf_appendstr(&qu->search_vb,nextentry))
+      goto x_nomemory;

   }
   }

-  if (wr<qu->querylen) {
-    r= vbuf_append(&ads->tcpsend,qu->querymsg+wr,qu->querylen-wr); assert(r);
+
+  free(qu->query_dgram);
+  qu->query_dgram= 0; qu->query_dglen= 0;
+
+  query_simple(ads,qu, qu->search_vb.buf, qu->search_vb.used,
+              qu->typei, qu->flags, now);
+  return;
+
+x_nomemory:
+  stat= adns_s_nomemory;
+x_fail:
+  adns__query_fail(qu,stat);
+}
+
+static int save_owner(adns_query qu, const char *owner, int ol) {
+  /* Returns 1 if OK, otherwise there was no memory. */
+  adns_answer *ans;
+
+  if (!(qu->flags & adns_qf_owner)) return 1;
+
+  ans= qu->answer;
+  assert(!ans->owner);
+
+  ans->owner= adns__alloc_preserved(qu,ol+1);  if (!ans->owner) return 0;
+
+  memcpy(ans->owner,owner,ol);
+  ans->owner[ol]= 0;
+  return 1;
+}
+
+int adns_submit(adns_state ads,
+               const char *owner,
+               adns_rrtype type,
+               adns_queryflags flags,
+               void *context,
+               adns_query *query_r) {
+  int r, ol, ndots;
+  adns_status stat;
+  const typeinfo *typei;
+  struct timeval now;
+  adns_query qu;
+  const char *p;
+
+  adns__consistency(ads,0,cc_entex);
+
+  typei= adns__findtype(type);
+  if (!typei) return ENOSYS;
+
+  r= gettimeofday(&now,0); if (r) goto x_errno;
+  qu= query_alloc(ads,typei,type,flags,now); if (!qu) goto x_errno;
+  
+  qu->ctx.ext= context;
+  qu->ctx.callback= 0;
+  memset(&qu->ctx.pinfo,0,sizeof(qu->ctx.pinfo));
+  memset(&qu->ctx.tinfo,0,sizeof(qu->ctx.tinfo));
+
+  *query_r= qu;
+
+  ol= strlen(owner);
+  if (!ol) { stat= adns_s_querydomaininvalid; goto x_adnsfail; }
+  if (ol>DNS_MAXDOMAIN+1) { stat= adns_s_querydomaintoolong; goto x_adnsfail; }
+                                
+  if (ol>=1 && owner[ol-1]=='.' && (ol<2 || owner[ol-2]!='\\')) {
+    flags &= ~adns_qf_search;
+    qu->flags= flags;
+    ol--;
+  }
+
+  if (flags & adns_qf_search) {
+    r= adns__vbuf_append(&qu->search_vb,owner,ol);
+    if (!r) { stat= adns_s_nomemory; goto x_adnsfail; }
+
+    for (ndots=0, p=owner; (p= strchr(p,'.')); p++, ndots++);
+    qu->search_doneabs= (ndots >= ads->searchndots) ? -1 : 0;
+    qu->search_origlen= ol;
+    adns__search_next(ads,qu,now);
+  } else {
+    if (flags & adns_qf_owner) {
+      if (!save_owner(qu,owner,ol)) { stat= adns_s_nomemory; goto x_adnsfail; }
+    }
+    query_simple(ads,qu, owner,ol, typei,flags, now);

   }
   }

+  adns__autosys(ads,now);
+  adns__returning(ads,qu);
+  return 0;
+
+ x_adnsfail:
+  adns__query_fail(qu,stat);
+  adns__returning(ads,qu);
+  return 0;
+
+ x_errno:
+  r= errno;
+  assert(r);
+  adns__returning(ads,0);
+  return r;
+}
+
+int adns_submit_reverse_any(adns_state ads,
+                           const struct sockaddr *addr,
+                           const char *zone,
+                           adns_rrtype type,
+                           adns_queryflags flags,
+                           void *context,
+                           adns_query *query_r) {
+  char *buf, *buf_free = 0;
+  char shortbuf[100];
+  int r;
+
+  flags &= ~adns_qf_search;
+
+  buf = shortbuf;
+  r= adns__make_reverse_domain(addr,zone, &buf,sizeof(shortbuf),&buf_free);
+  if (r) return r;
+  r= adns_submit(ads,buf,type,flags,context,query_r);
+  free(buf_free);
+  return r;

 }
 
 }
 

-static void query_usetcp(adns_state ads, adns_query qu, struct timeval now) {
-  timevaladd(&now,TCPMS);
-  qu->timeout= now;
-  qu->state= query_tcpwait;
-  DLIST_LINKTAIL(ads->timew,qu);
-  adns__query_tcp(ads,qu);
-  adns__tcp_tryconnect(ads);
+int adns_submit_reverse(adns_state ads,
+                       const struct sockaddr *addr,
+                       adns_rrtype type,
+                       adns_queryflags flags,
+                       void *context,
+                       adns_query *query_r) {
+  if (((type^adns_r_ptr) & adns_rrt_reprmask) &&
+      ((type^adns_r_ptr_raw) & adns_rrt_reprmask))
+    return EINVAL;
+  return adns_submit_reverse_any(ads,addr,0,type,flags,context,query_r);

 }
 
 }
 

-void adns__query_udp(adns_state ads, adns_query qu, struct timeval now) {
-  /* Query must be in state udp/NONE; it will be moved to a new state,
-   * and no further processing can be done on it for now.
-   * (Resulting state is one of udp/timew, tcpwait/timew (if server not connected),
-   *  tcpsent/timew, child/childw or done/output.)
+int adns_synchronous(adns_state ads,
+                    const char *owner,
+                    adns_rrtype type,
+                    adns_queryflags flags,
+                    adns_answer **answer_r) {
+  adns_query qu;
+  int r;
+  
+  r= adns_submit(ads,owner,type,flags,0,&qu);
+  if (r) return r;
+
+  r= adns_wait(ads,&qu,answer_r,0);
+  if (r) adns_cancel(qu);
+
+  return r;
+}
+
+static void *alloc_common(adns_query qu, size_t sz) {
+  allocnode *an;
+
+  if (!sz) return qu; /* Any old pointer will do */
+  assert(!qu->final_allocspace);
+  an= malloc(MEM_ROUND(MEM_ROUND(sizeof(*an)) + sz));
+  if (!an) return 0;
+  LIST_LINK_TAIL(qu->allocations,an);
+  an->sz= sz;
+  return (byte*)an + MEM_ROUND(sizeof(*an));
+}
+
+void *adns__alloc_interim(adns_query qu, size_t sz) {
+  void *rv;
+  
+  sz= MEM_ROUND(sz);
+  rv= alloc_common(qu,sz);
+  if (!rv) return 0;
+  qu->interim_allocd += sz;
+  return rv;
+}
+
+void *adns__alloc_preserved(adns_query qu, size_t sz) {
+  void *rv;
+  
+  sz= MEM_ROUND(sz);
+  rv= adns__alloc_interim(qu,sz);
+  if (!rv) return 0;
+  qu->preserved_allocd += sz;
+  return rv;
+}
+
+static allocnode *alloc_info(adns_query qu, void *p, size_t *sz_r) {
+  allocnode *an;
+
+  if (!p || p == qu) { *sz_r= 0; return 0; }
+  an= (allocnode *)((byte *)p - MEM_ROUND(sizeof(allocnode)));
+  *sz_r= MEM_ROUND(an->sz);
+  return an;
+}
+
+void adns__free_interim(adns_query qu, void *p) {
+  size_t sz;
+  allocnode *an= alloc_info(qu, p, &sz);
+
+  if (!an) return;
+  assert(!qu->final_allocspace);
+  LIST_UNLINK(qu->allocations, an);
+  free(an);
+  qu->interim_allocd -= sz;
+}
+
+void *adns__alloc_mine(adns_query qu, size_t sz) {
+  return alloc_common(qu,MEM_ROUND(sz));
+}
+
+void adns__transfer_interim(adns_query from, adns_query to, void *block) {
+  size_t sz;
+  allocnode *an= alloc_info(from, block, &sz);
+
+  if (!an) return;
+
+  assert(!to->final_allocspace);
+  assert(!from->final_allocspace);
+  
+  LIST_UNLINK(from->allocations,an);
+  LIST_LINK_TAIL(to->allocations,an);
+
+  from->interim_allocd -= sz;
+  to->interim_allocd += sz;
+
+  if (to->expires > from->expires) to->expires= from->expires;
+}
+
+void *adns__alloc_final(adns_query qu, size_t sz) {
+  /* When we're in the _final stage, we _subtract_ from interim_alloc'd
+   * each allocation, and use final_allocspace to point to the next free
+   * bit.

    */
    */

-  struct sockaddr_in servaddr;
-  int serv;
-
-  assert(qu->state == query_udp);
-  if ((qu->flags & adns_f_usevc) ||
-      (qu->querylen > UDPMAXDGRAM)) {
-    query_usetcp(ads,qu,now);
-    return;
+  void *rp;
+
+  sz= MEM_ROUND(sz);
+  rp= qu->final_allocspace;
+  assert(rp);
+  qu->interim_allocd -= sz;
+  assert(qu->interim_allocd>=0);
+  qu->final_allocspace= (byte*)rp + sz;
+  return rp;
+}
+
+void adns__cancel_children(adns_query qu) {
+  adns_query cqu, ncqu;
+
+  for (cqu= qu->children.head; cqu; cqu= ncqu) {
+    ncqu= cqu->siblings.next;
+    adns__cancel(cqu);

   }
   }

+}

 
 

-  if (qu->udpretries >= UDPMAXRETRIES) {
-    query_fail(ads,qu,adns_s_notresponding);
-    return;
+void adns__reset_preserved(adns_query qu) {
+  assert(!qu->final_allocspace);
+  adns__cancel_children(qu);
+  qu->answer->nrrs= 0;
+  qu->answer->rrs.untyped= 0;
+  qu->interim_allocd= qu->preserved_allocd;
+}
+
+static void free_query_allocs(adns_query qu) {
+  allocnode *an, *ann;
+
+  adns__cancel_children(qu);
+  for (an= qu->allocations.head; an; an= ann) { ann= an->next; free(an); }
+  LIST_INIT(qu->allocations);
+  adns__vbuf_free(&qu->vb);
+  adns__vbuf_free(&qu->search_vb);
+  free(qu->query_dgram);
+  qu->query_dgram= 0;
+}
+
+void adns__returning(adns_state ads, adns_query qu_for_caller) {
+  adns__consistency(ads,qu_for_caller,cc_entex);
+}
+
+void adns__cancel(adns_query qu) {
+  adns_state ads;
+
+  ads= qu->ads;
+  adns__consistency(ads,qu,cc_freq);
+  if (qu->parent) LIST_UNLINK_PART(qu->parent->children,qu,siblings.);
+  switch (qu->state) {
+  case query_tosend:
+    LIST_UNLINK(ads->udpw,qu);
+    break;
+  case query_tcpw:
+    LIST_UNLINK(ads->tcpw,qu);
+    break;
+  case query_childw:
+    LIST_UNLINK(ads->childw,qu);
+    break;
+  case query_done:
+    LIST_UNLINK(ads->output,qu);
+    break;
+  default:
+    abort();

   }
   }

+  free_query_allocs(qu);
+  free(qu->answer);
+  free(qu);
+}

 
 

-  serv= qu->nextudpserver;
-  memset(&servaddr,0,sizeof(servaddr));
-  servaddr.sin_family= AF_INET;
-  servaddr.sin_addr= ads->servers[serv].addr;
-  servaddr.sin_port= htons(NSPORT);
+void adns_cancel(adns_query qu) {
+  adns_state ads;
+
+  assert(!qu->parent);
+  ads= qu->ads;
+  adns__consistency(ads,qu,cc_entex);
+  adns__cancel(qu);
+  adns__returning(ads,0);
+}
+
+void adns__update_expires(adns_query qu, unsigned long ttl,
+                         struct timeval now) {
+  time_t max;
+
+  assert(ttl <= MAXTTLBELIEVE);
+  max= now.tv_sec + ttl;
+  if (qu->expires < max) return;
+  qu->expires= max;
+}
+
+static void makefinal_query(adns_query qu) {
+  adns_answer *ans;
+  int rrn;
+
+  ans= qu->answer;
+
+  if (qu->interim_allocd) {
+    ans= realloc(qu->answer,
+                MEM_ROUND(MEM_ROUND(sizeof(*ans)) + qu->interim_allocd));
+    if (!ans) goto x_nomem;
+    qu->answer= ans;
+  }
+
+  qu->final_allocspace= (byte*)ans + MEM_ROUND(sizeof(*ans));
+  adns__makefinal_str(qu,&ans->cname);
+  adns__makefinal_str(qu,&ans->owner);
+  
+  if (ans->nrrs) {
+    adns__makefinal_block(qu, &ans->rrs.untyped, ans->nrrs*ans->rrsz);
+
+    for (rrn=0; rrn<ans->nrrs; rrn++)
+      qu->typei->makefinal(qu, ans->rrs.bytes + rrn*ans->rrsz);
+  }

   
   

-  r= sendto(ads->udpsocket,qu->querymsg,qu->querylen,0,&servaddr,sizeof(servaddr));
-  if (r<0 && errno == EMSGSIZE) { query_usetcp(ads,qu,now); return; }
-  if (r<0) warn("sendto %s failed: %s",inet_ntoa(servaddr.sin_addr),strerror(errno));
+  free_query_allocs(qu);
+  return;

   
   

-  timevaladd(&now,UDPRETRYMS);
-  qu->timeout= now;
-  qu->sentudp |= (1<<serv);
-  qu->nextudpserver= (serv+1)%ads->nservers;
-  qu->udpretries++;
-  DLIST_LINKTAIL(ads->timew,qu);
+ x_nomem:
+  qu->preserved_allocd= 0;
+  qu->answer->cname= 0;
+  qu->answer->owner= 0;
+  adns__reset_preserved(qu); /* (but we just threw away the preserved stuff) */
+
+  qu->answer->status= adns_s_nomemory;
+  free_query_allocs(qu);

 }
 
 }
 

-void adns__query_fail(adns_state ads, adns_query qu, adns_status stat) {
+void adns__query_done(adns_query qu) {

   adns_answer *ans;
   adns_answer *ans;

-  
+  adns_query parent;
+
+  adns__cancel_children(qu);
+
+  qu->id= -1;

   ans= qu->answer;
   ans= qu->answer;

-  if (!ans) ans= malloc(sizeof(*qu->answer));
-  if (ans) {
-    ans->status= stat;
-    ans->cname= 0;
-    ans->type= qu->type;
-    ans->nrrs= 0;
+
+  if (qu->flags & adns_qf_search && ans->status != adns_s_nomemory) {
+    if (!save_owner(qu, qu->search_vb.buf, qu->search_vb.used)) {
+      adns__query_fail(qu,adns_s_nomemory);
+      return;
+    }

   }
   }

-  qu->answer= ans;
-  qu->id= -1;
-  LIST_LINK_TAIL(ads->output,qu);
+
+  if (ans->nrrs && qu->typei->diff_needswap) {
+    if (!adns__vbuf_ensure(&qu->vb,qu->answer->rrsz)) {
+      adns__query_fail(qu,adns_s_nomemory);
+      return;
+    }
+    adns__isort(ans->rrs.bytes, ans->nrrs, ans->rrsz,
+               qu->vb.buf,
+               (int(*)(void*, const void*, const void*))
+                 qu->typei->diff_needswap,
+               qu->ads);
+  }
+  if (ans->nrrs && qu->typei->postsort) {
+    qu->typei->postsort(qu->ads, ans->rrs.bytes,
+                       ans->nrrs,ans->rrsz, qu->typei);
+  }
+
+  ans->expires= qu->expires;
+  parent= qu->parent;
+  if (parent) {
+    LIST_UNLINK_PART(parent->children,qu,siblings.);
+    LIST_UNLINK(qu->ads->childw,parent);
+    qu->ctx.callback(parent,qu);
+    free_query_allocs(qu);
+    free(qu->answer);
+    free(qu);
+  } else {
+    makefinal_query(qu);
+    LIST_LINK_TAIL(qu->ads->output,qu);
+    qu->state= query_done;
+  }
+}
+
+void adns__query_fail(adns_query qu, adns_status stat) {
+  adns__reset_preserved(qu);
+  qu->answer->status= stat;
+  adns__query_done(qu);
+}
+
+void adns__makefinal_str(adns_query qu, char **strp) {
+  int l;
+  char *before, *after;
+
+  before= *strp;
+  if (!before) return;
+  l= strlen(before)+1;
+  after= adns__alloc_final(qu,l);
+  memcpy(after,before,l);
+  *strp= after;  
+}
+
+void adns__makefinal_block(adns_query qu, void **blpp, size_t sz) {
+  void *before, *after;
+
+  before= *blpp;
+  if (!before) return;
+  after= adns__alloc_final(qu,sz);
+  memcpy(after,before,sz);
+  *blpp= after;

 }
 }