X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=adns.git;a=blobdiff_plain;f=src%2Fquery.c;h=a35d8ba4bb799039ba4cf0a2b553857e8ce63ab3;hp=f12e1a381e306c6d3e3bb162435cd1975b88830b;hb=636b69b1a03bec395d304c354f4f2f8121b97150;hpb=4bec51a44bf61bca32e7b947f20b1e7d0f971b94

diff --git a/src/query.c b/src/query.c
index f12e1a3..a35d8ba 100644
--- a/src/query.c
+++ b/src/query.c
@@ -1,189 +1,496 @@
-/**/
+/*
+ * 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) 1997-1999 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 "internal.h"
 
-adns_status adns__mkquery(adns_state ads, const char *owner, int ol, int id,
-			  adns_rrtype type, adns_queryflags flags, int *qml_r) {
-  int ll, c, nlabs, qbufreq;
-  unsigned char label[255], *nqbuf;
-  const char *p, *pe;
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
 
-#define MKQUERY_ADDB(b) *nqbuf++= (b)
-#define MKQUERY_ADDW(w) (MKQUERY_ADDB(((w)>>8)&0x0ff), MKQUERY_ADDB((w)&0x0ff))
+#include <sys/time.h>
 
-  qbufreq= 12+strlen(owner)+3;
-  if (ads->qbufavail < qbufreq) {
-    nqbuf= realloc(ads->qbuf,qbufreq);
-    if (!nqbuf) return adns_s_nolocalmem;
-    ads->qbuf= nqbuf; ads->qbufavail= qbufreq;
-  }
-  nqbuf= ads->qbuf;
-  
-  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(nqbuf,label,ll); nqbuf+= ll;
-  } while (p!=pe);
+#include "internal.h"
+
+static adns_query query_alloc(adns_state ads, const typeinfo *typei,
+			      adns_queryflags flags, struct timeval now) {
+  /* Allocate a virgin query and return it. */
+  adns_query qu;
+  
+  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= 0;
+  qu->flags= flags;
+  qu->udpretries= 0;
+  qu->udpnextserver= 0;
+  qu->udpsent= qu->tcpfailed= 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= typei->type;
+  qu->answer->expires= -1;
+  qu->answer->nrrs= 0;
+  qu->answer->rrs.untyped= 0;
+  qu->answer->rrsz= typei->rrsz;
+
+  return qu;
+}
 
-  MKQUERY_ADDB(0);
-  MKQUERY_ADDW(type & adns__rrt_typemask); /* QTYPE */
-  MKQUERY_ADDW(1); /* QCLASS=IN */
+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.
+   */
+
+  qu->vb= *qumsg_vb;
+  adns__vbuf_init(qumsg_vb);
+
+  qu->query_dgram= malloc(qu->vb.used);
+  if (!qu->query_dgram) { adns__query_fail(qu,adns_s_nomemory); return; }
+  
+  qu->id= id;
+  qu->query_dglen= qu->vb.used;
+  memcpy(qu->query_dgram,qu->vb.buf,qu->vb.used);
+  
+  adns__query_send(qu,now);
+  adns__autosys(ads,now);
+}
+
+adns_status adns__internal_submit(adns_state ads, adns_query *query_r,
+				  const typeinfo *typei, vbuf *qumsg_vb, int id,
+				  adns_queryflags flags, struct timeval now,
+				  const qcontext *ctx) {
+  adns_query qu;
+
+  qu= query_alloc(ads,typei,flags,now);
+  if (!qu) { adns__vbuf_free(qumsg_vb); return adns_s_nomemory; }
+  *query_r= qu;
 
-  *qml_r= nqbuf - ads->qbuf;
+  memcpy(&qu->ctx,ctx,sizeof(qu->ctx));
+  query_submit(ads,qu, typei,qumsg_vb,id,flags,now);
   
   return adns_s_ok;
 }
 
-static void quproc_tosend_tcp(adns_state ads, adns_query qu, struct timeval now) {
-  unsigned char length[2];
-  struct iovec iov[2];
+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;
+  int id;
+  adns_status stat;
 
-  length[0]= (qu->querylen&0x0ff00U) >>8;
-  length[1]= (qu->querylen&0x0ff);
+  adns__vbuf_init(&vb);
   
-  adns__tcp_tryconnect(ads);
-  /* fixme: try sending queries as soon as server comes up */
-  /* fixme: use vbuf_ensure, and preallocate buffer space */
-  if (ads->tcpstate != server_ok) return;
+  stat= adns__mkquery(ads,&vb,&id, owner,ol, typei,flags);
+  if (stat) { adns__query_fail(qu,stat); return; }
 
-  DLIST_UNLINK(ads->tosend,qu);
-  timevaladd(&now,TCPMS);
-  qu->timeout= now;
-  qu->senttcpserver= ads->tcpserver;
-  DLIST_LINKTAIL(ads->timew,qu);
+  query_submit(ads,qu, typei,&vb,id, flags,now);
+}
 
-  if (ads->opbufused) {
-    r= 0;
+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 {
-    iov[0].iovbase= length;
-    iov[0].iov_len= 2;
-    iov[1].iovbase= qu->querymsg;
-    iov[1].iov_len= qu->querylen;
-    r= writev(ads->tcpsocket,iov,2);
-    if (r < 0) {
-      if (!(errno == EAGAIN || errno == EINTR || errno == ENOSPC ||
-	    errno == ENOBUFS || errno == ENOMEM)) {
-	adns__tcp_broken(ads,"write",strerror(errno));
+    if (qu->search_pos >= ads->nsearchlist) {
+      if (qu->search_doneabs) {
+	stat= adns_s_nxdomain; goto x_fail;
 	return;
+      } else {
+	nextentry= 0;
+	qu->search_doneabs= 1;
       }
-      r= 0;
+    } else {
+      nextentry= ads->searchlist[qu->search_pos++];
     }
   }
-  
-  if (r < qu->querylen+2) {
-    newopbufused= qu->opbufused + qu->querylen + 2 - r;
-    if (newopbufused > ads->opbufavail) {
-      newopbufavail= ads->newopbufused<<1;
-      newopbuf= realloc(newopbufavail);
-      if (!newopbuf) {
-	DLIST_UNLINK(ads->timew,qu);
-	query_fail(ads,qu,adns_s_nolocalmem);
-	return;
-      }
-      ads->opbuf= newopbuf;
-      ads->opbufavail= newopbufavail;
+
+  qu->search_vb.used= qu->search_origlen;
+  if (nextentry) {
+    if (!adns__vbuf_append(&qu->search_vb,".",1) ||
+	!adns__vbuf_appendstr(&qu->search_vb,nextentry)) {
+      stat= adns_s_nomemory; goto x_fail;
     }
-    if (r<2) {
-      memcpy(ads->opbuf+ads->opbufused,length+r,2-r);
-      ads->opbufused += (2-r);
-      r= 0;
-    } else {
-      r -= 2;
+  }
+
+  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_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;
+
+  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;
+
+  typei= adns__findtype(type);
+  if (!typei) return ENOSYS;
+
+  r= gettimeofday(&now,0); if (r) goto x_errno;
+  qu= query_alloc(ads,typei,flags,now); if (!qu) goto x_errno;
+  
+  qu->ctx.ext= context;
+  qu->ctx.callback= 0;
+  memset(&qu->ctx.info,0,sizeof(qu->ctx.info));
+
+  *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;
+    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; }
     }
-    memcpy(ads->opbuf+ads->opbufused,qu->querymsg+r,qu->querylen-r);
-    ads->opbufused= newopbufused;
+    query_simple(ads,qu, owner,ol, typei,flags, now);
   }
+  return 0;
+
+ x_adnsfail:
+  adns__query_fail(qu,stat);
+  return 0;
+
+ x_errno:
+  r= errno;
+  assert(r);
+  return r;
 }
 
-void adns__quproc_tosend(adns_state ads, adns_query qu, struct timeval now) {
-  /* Query must be on the `tosend' queue, and we guarantee to remove it.
+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);
+  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;
+}
+
+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;
+
+  if (!block) return;
+  an= (void*)((byte*)block - MEM_ROUND(sizeof(*an)));
+
+  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;
-
-  if (qu->nextudpserver == -1) { quproc_tosend_tcp(ads,qu,now); return; }
-  if (qu->querylen > UDPMAXDGRAM) {
-    qu->nextudpserver= -1;
-    quproc_tosend_tcp(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;
+}
+
+static void 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) {
-    DLIST_UNLINK(ads->tosend,qu);
-    query_fail(ads,qu,adns_s_notresponding);
-    return;
+  LIST_INIT(qu->children);
+}
+
+void adns__reset_preserved(adns_query qu) {
+  assert(!qu->final_allocspace);
+  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;
+
+  cancel_children(qu);
+  for (an= qu->allocations.head; an; an= ann) { ann= an->next; free(an); }
+  adns__vbuf_free(&qu->vb);
+}
+
+void adns_cancel(adns_query qu) {
+  switch (qu->state) {
+  case query_tosend: case query_tcpwait: case query_tcpsent:
+    LIST_UNLINK(qu->ads->timew,qu);
+    break;
+  case query_child:
+    LIST_UNLINK(qu->ads->childw,qu);
+    break;
+  case query_done:
+    LIST_UNLINK(qu->ads->output,qu);
+    break;
+  default:
+    abort();
+  }
+  free_query_allocs(qu);
+  free(qu->answer);
+  free(qu);
+}
+
+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;
   }
 
-  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);
+  qu->final_allocspace= (byte*)ans + MEM_ROUND(sizeof(*ans));
+  adns__makefinal_str(qu,&ans->cname);
+  adns__makefinal_str(qu,&ans->owner);
   
-  r= sendto(ads->udpsocket,qu->querymsg,qu->querylen,0,&servaddr,sizeof(servaddr));
-  if (r<0 && errno == EMSGSIZE) {
-    qu->nextudpserver= -1;
-    quproc_tosend_tcp(ads,qu,now); return;
+  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);
   }
-  if (r<0) warn("sendto %s failed: %s",inet_ntoa(servaddr.sin_addr),strerror(errno));
   
-  DLIST_UNLINK(ads->tosend,qu);
-  timevaladd(&now,UDPRETRYMS);
-  qu->timeout= now;
-  qu->sentudp |= (1<<serv);
-  qu->nextudpserver= (serv+1)%ads->nservers;
-  qu->udpretries++;
-  DLIST_LINKTAIL(ads->timew,qu);
+  free_query_allocs(qu);
+  return;
+  
+ 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_query parent;
+
+  cancel_children(qu);
+
+  qu->id= -1;
   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_owner && 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->typei->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);
+  }
+
+  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);
+  } else {
+    makefinal_query(qu);
+    LIST_LINK_TAIL(qu->ads->output,qu);
+  }
+}
+
+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;
 }