X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=chiark-tcl.git;a=blobdiff_plain;f=adns%2Fadns.c;h=6405f0016d103f7b5643fb7a077a82e535f4fb09;hp=5f26d327d0a3029c606b97ed4c250474fa44f6eb;hb=5dca360f2da544c9b6baf9d18ad8cd0b0e073e60;hpb=b1aa186fec2f36c274e71886e858408b1aa93e6d;ds=sidebyside

diff --git a/adns/adns.c b/adns/adns.c
index 5f26d32..6405f00 100644
--- a/adns/adns.c
+++ b/adns/adns.c
@@ -1,5 +1,3 @@
-/*
- */
 /*
  * adns lookup TYPE DOMAIN [QUERY-OPTIONS]                    => [list RDATA]
  *    if no or dontknow, throws an exception, with errorCode one of
@@ -37,6 +35,8 @@
  *         -quotefail-cname
  *         -cname-loose
  *         -cname-forbid
+ *         -reverse
+ *         -reverse-any ZONE-A-LIKE
  *
  * adns new-resolver [RES-OPTIONS...]                         => RESOLVER
  *        options:
@@ -46,25 +46,60 @@
  *         -noenv|-debug|-logpid
  *         -checkc-entex
  *         -checkc-freq
- *         -reverse
- *         -reverse-any ZONE-A-LIKE
  *         -config CONFIG-STRING
  *
+ * adns set-default-resolver RESOLVER
+ *        cancels any outstanding queries from a previous anonymous
+ *        default resolver
+ *
  * adns destroy-resolver RESOLVER
+ *        cancels outstanding queries
+ *
+ */
+/* ---8<--- end of documentation comment --8<-- */
+
+/*
+ * adns.c - adns binding for Tcl
+ * Copyright 2006 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 of the
+ * License, 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 library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
  */
 
-#include "tables.h"
-#include "hbytes.h"
+#define _GNU_SOURCE
+
+#include <stdio.h>
+
+#include <adns.h>
+
+#include "chiark_tcl_adns.h"
 
 /*---------- important types and forward declarations ----------*/
 
 typedef struct Query Query;
 typedef struct Resolver Resolver;
 typedef struct OptionInfo OptionInfo;
-static void asynch_check(Resolver *res);
-static void asynch_sethandlers(Resolver *res, int shutdown);
+
+static void asynch_sethandlers(Resolver *res);
+static void asynch_cancelhandlers(Resolver *res);
+static void asynch_perturbed(Resolver *res);
+
 static void asynch_query_dispose(Tcl_Interp *interp, Query *query);
 
+#define ASSOC_DEFAULTRES "adns-defaultresolver"
+
 /*---------- common resolver/query option processing ----------*/
 
 typedef struct {
@@ -90,7 +125,6 @@ struct OptionInfo {
 };
 
 enum {
-  oisf_makedefault= 0x0001,
   oisf_reverse=     0x0002
 };
 
@@ -106,7 +140,7 @@ static int oifn_fs(Tcl_Interp *ip, const OptionInfo *oi, Tcl_Obj *arg,
 
 static int oifn_reverse_any(Tcl_Interp *ip, const OptionInfo *oi,
 			    Tcl_Obj *arg, OptionParse *op) {
-  return pat_string(ip,arg,&op->reverseany);
+  return cht_pat_string(ip,arg,&op->reverseany);
 }
 
 #define OIFA1(t,f,r) { "-" #f, oifn_fa, 0, adns_##t##_##f, r }
@@ -114,6 +148,13 @@ static int oifn_reverse_any(Tcl_Interp *ip, const OptionInfo *oi,
 #define OIFS(f) { "-" #f, oifn_fs, 0, oisf_##f, 0 }
 #define OICA(o) { "-" #o, oifn_##o, 1 }
 
+static void optparse_blank(OptionParse *op) {
+  memset(op,0,sizeof(*op));
+  op->errfile= stderr;
+  op->errcallback= 0;
+  op->config_string= 0;
+}
+
 static int parse_options(Tcl_Interp *ip, int objc, Tcl_Obj *const *objv,
 			 const OptionInfo opttable[], OptionParse *op) {
   const OptionInfo *oi;
@@ -124,14 +165,14 @@ static int parse_options(Tcl_Interp *ip, int objc, Tcl_Obj *const *objv,
   objc--; objv++;
   for (;;) {
     if (!objc--) break;
-    rc= pat_enum(ip, *objv++, &oi_v, opttable, sizeof(OptionInfo),
+    rc= cht_pat_enum(ip, *objv++, &oi_v, opttable, sizeof(OptionInfo),
 		 "query or resolver option");
     if (rc) return rc;
     oi= oi_v;
 
     if (oi->takesarg) {
       if (!objc--) {
-	setstringresult(ip,"missing value for option");
+	cht_setstringresult(ip,"missing value for option");
 	return TCL_ERROR;
       }
       arg= *objv++;
@@ -153,17 +194,26 @@ struct Resolver {
   Tcl_TimerToken timertoken;
   int maxfd;
   fd_set handling[3];
+  ScriptToInvoke errcallback;
+  Tcl_Obj *errstring_accum;
 };
 
+/* The default resolver is recorded using Tcl_SetAssocData with key
+ * ASSOC_DEFAULTRES to record the Resolver*.  If it was explicitly
+ * created with `adns new-resolver' then ix will be >=0, and the
+ * resolver will be destroyed - leaving no default - when explicitly
+ * requested.  If it was implicitly created (by starting a query when
+ * there is no default) then ix will be -1.  */
+
 static int oifn_errfile(Tcl_Interp *ip, const OptionInfo *oi,
 			Tcl_Obj *arg, OptionParse *op) {
   int rc;
   const char *str;
   
-  rc= pat_string(ip,arg,&str);  if (rc) return rc;
+  rc= cht_pat_string(ip,arg,&str);  if (rc) return rc;
   if (!strcmp(str,"stderr")) op->errfile= stderr;
   else if (!strcmp(str,"stdout")) op->errfile= stdout;
-  else return staticerr(ip,"-errfile argument must be stderr or stdout",0);
+  else return cht_staticerr(ip,"-errfile argument must be stderr or stdout",0);
 
   op->aflags &= ~adns_if_noerrprint;
   op->errcallback= 0;
@@ -180,7 +230,7 @@ static int oifn_errcallback(Tcl_Interp *ip, const OptionInfo *oi,
 
 static int oifn_config(Tcl_Interp *ip, const OptionInfo *oi,
 		       Tcl_Obj *arg, OptionParse *op) {
-  return pat_string(ip,arg,&op->config_string);
+  return cht_pat_string(ip,arg,&op->config_string);
 }
 
 static const OptionInfo resolver_optioninfos[]= {
@@ -190,22 +240,64 @@ static const OptionInfo resolver_optioninfos[]= {
   OIFA1(if,noerrprint, adns_if_debug),
   OIFA2(if,checkc,entex),
   OIFA2(if,checkc,freq),
-  OIFS(makedefault),
   OICA(errfile),
   OICA(errcallback),
   OICA(config),
   { 0 }
 };
 
+static void adnslogfn_flushmessage(Resolver *res) {
+  cht_scriptinv_invoke(&res->errcallback, 1, &res->errstring_accum);
+  Tcl_SetObjLength(res->errstring_accum, 0);
+}
+
 static void adnslogfn_callback(adns_state ads, void *logfndata,
 			       const char *fmt, va_list al) {
-  abort(); /* fixme implement adns_logcallbackfn */
+  Resolver *res= logfndata;
+  int l, newline;
+  char *str;
+
+  l= vasprintf(&str,fmt,al);
+  if (l<0) {
+    cht_posixerr(res->interp,errno,"construct adns log callback string");
+    Tcl_BackgroundError(res->interp);
+  }
+
+  if (l==0) { free(str); return; }
+  if ((newline= l>0 && str[l-1]=='\n')) l--;
+
+  if (!res->errstring_accum) {
+    res->errstring_accum= Tcl_NewStringObj(str,l);
+    Tcl_IncrRefCount(res->errstring_accum);
+  } else {
+    Tcl_AppendToObj(res->errstring_accum,str,l);
+  }
+  free(str);
+
+  if (newline)
+    adnslogfn_flushmessage(res);
+}
+
+static Resolver *default_resolver(Tcl_Interp *ip) {
+  return Tcl_GetAssocData(ip,ASSOC_DEFAULTRES,0);
 }
 
 static void destroy_resolver(Tcl_Interp *ip, Resolver *res) {
   void *query_v;
+  int logstring_len;
+  char *rstr;
   adns_query aqu;
-  
+ 
+  if (res == default_resolver(ip))
+    Tcl_DeleteAssocData(ip,ASSOC_DEFAULTRES);
+ 
+  if (res->errstring_accum) {
+    rstr= Tcl_GetStringFromObj(res->errstring_accum, &logstring_len);
+    assert(rstr);
+    if (logstring_len)
+      adnslogfn_flushmessage(res);
+  }
+
   if (res->ads) {
     /* although adns would throw these away for us, we need to
      * destroy our own data too and only adns has a list of them */
@@ -216,60 +308,52 @@ static void destroy_resolver(Tcl_Interp *ip, Resolver *res) {
       asynch_query_dispose(ip, query_v);
     }
     adns_finish(res->ads);
+    res->ads= 0;
   }
-  asynch_sethandlers(res,1);
-  TFREE(res);
-  /* fixme what about the default resolver */
+  asynch_cancelhandlers(res);
+  cht_scriptinv_cancel(&res->errcallback);
+  Tcl_EventuallyFree(res, Tcl_Free);
 }
 
 static void destroy_resolver_idtabcb(Tcl_Interp *ip, void *resolver_v) {
   destroy_resolver(ip,resolver_v);
 }
+static void destroy_resolver_defcb(ClientData resolver_v, Tcl_Interp *ip) {
+  destroy_resolver(ip,resolver_v);
+}
 
-int do_adns_destroy_resolver(ClientData cd, Tcl_Interp *ip, void *res_v) {
+int cht_do_adns_destroy_resolver(ClientData cd, Tcl_Interp *ip, void *res_v) {
+  cht_tabledataid_disposing(ip,res_v,&adnstcl_resolvers);
   destroy_resolver(ip,res_v);
-  tabledataid_disposing(ip,res_v,&adnstcl_resolvers);
   return TCL_OK;
 }
 
-int do_adns_new_resolver(ClientData cd, Tcl_Interp *ip,
-			 int objc, Tcl_Obj *const *objv,
-			 void **result) {
-  OptionParse op;
+static int create_resolver(Tcl_Interp *ip, const OptionParse *op,
+			   Resolver **res_r) {
   Resolver *res=0;
   int rc, i, ec;
-
-  op.aflags= adns_if_noautosys;
-  op.sflags= 0;
-  op.errfile= 0;
-  op.errcallback= 0;
-  op.config_string= 0;
-  rc= parse_options(ip,objc,objv,resolver_optioninfos,&op);
-  if (rc) goto x_rc;
-
-  res= TALLOC(sizeof(*res)); assert(res);
+  
+  res= TALLOC(sizeof(*res));  assert(res);
   res->ix= -1;
   res->interp= ip;
   res->ads= 0;
   res->timertoken= 0;
   res->maxfd= 0;
   for (i=0; i<3; i++) FD_ZERO(&res->handling[i]);
+  cht_scriptinv_init(&res->errcallback);
+  res->errstring_accum= 0;
 
-  if (op.aflags & adns_if_noerrprint) {
-    op.errfile= 0;
-    op.errcallback= 0;
-  }
-
-  ec= adns_init_logfn(&res->ads, op.aflags, op.config_string,
-		      op.errcallback ? adnslogfn_callback : 0,
-		      op.errcallback ? (void*)op.errcallback
-		      : (void*)op.errfile);
-  if (ec) { rc= posixerr(ip,ec,"create adns resolver"); goto x_rc; }
+  if (op->errcallback)
+    cht_scriptinv_set(&res->errcallback, ip, op->errcallback, 0);
 
-  if (op.errcallback)
-    Tcl_IncrRefCount(op.errcallback);
+  ec= adns_init_logfn(&res->ads,
+		      op->aflags | adns_if_noautosys,
+		      op->config_string,
+		      op->errcallback ? adnslogfn_callback : 0,
+		      op->errcallback ? (void*)res : (void*)op->errfile);
+  if (ec) { rc= cht_posixerr(ip,ec,"create adns resolver"); goto x_rc; }
 
-  *result= res;
+  *res_r= res;
   return TCL_OK;
 
  x_rc:
@@ -278,9 +362,39 @@ int do_adns_new_resolver(ClientData cd, Tcl_Interp *ip,
     TFREE(res);
   }
   return rc;
+}  
+
+int cht_do_adns_new_resolver(ClientData cd, Tcl_Interp *ip,
+			 int objc, Tcl_Obj *const *objv,
+			 void **result) {
+  OptionParse op;
+  Resolver *res=0;
+  int rc;
+
+  optparse_blank(&op);
+  rc= parse_options(ip,objc,objv,resolver_optioninfos,&op);
+  if (rc) return rc;
+
+  if (op.aflags & adns_if_noerrprint) {
+    op.errfile= 0;
+    op.errcallback= 0;
+  }
+
+  rc= create_resolver(ip, &op, &res);
+  if (rc) return rc;
+
+  *result= res;
+  return TCL_OK;
+}
+
+int cht_do_adns_set_default_resolver(ClientData cd, Tcl_Interp *ip, void *res_v) {
+  Resolver *res= res_v;
+  Tcl_DeleteAssocData(ip,ASSOC_DEFAULTRES);
+  Tcl_SetAssocData(ip, ASSOC_DEFAULTRES, 0, res);
+  return TCL_OK;
 }
 
-const IdDataSpec adnstcl_resolvers= {
+const IdDataSpec cht_adnstcl_resolvers= {
   "adns-res", "adns-resolvers-table", destroy_resolver_idtabcb
 };
 
@@ -291,7 +405,7 @@ const IdDataSpec adnstcl_resolvers= {
 #define RRTYPE_PLUS(t) { #t "+", adns_r_##t }
 #define RRTYPE_MINUS(t) { #t "-", adns_r_##t##_raw }
 
-const AdnsTclRRTypeInfo adnstclrrtypeinfos[]= {
+const AdnsTclRRTypeInfo cht_adnstclrrtypeinfo_entries[]= {
   RRTYPE_EXACTLY(a),
   RRTYPE_EXACTLY(cname),
   RRTYPE_EXACTLY(hinfo),
@@ -315,7 +429,7 @@ static int oifn_resolver(Tcl_Interp *ip, const OptionInfo *oi,
   void *val_v;
   int rc;
   
-  rc= pat_iddata(ip,arg,&val_v,&adnstcl_resolvers);
+  rc= cht_pat_iddata(ip,arg,&val_v,&adnstcl_resolvers);
   if (rc) return rc;
   op->resolver= val_v;
   return TCL_OK;
@@ -338,20 +452,36 @@ static const OptionInfo query_optioninfos[]= {
 static int query_submit(Tcl_Interp *ip,
 			const AdnsTclRRTypeInfo *type, const char *domain,
 			int queryopts_objc, Tcl_Obj *const *queryopts_objv,
-			adns_query *aqu_r, void *context, OptionParse *op) {
+			adns_query *aqu_r, void *context, Resolver **res_r) {
   struct sockaddr sa;
   static const int aftry[]= { AF_INET, AF_INET6 };
+  OptionParse op;
+  OptionParse res_op;
   int rc, r, ec;
   adns_state ads;
   
-  op->aflags= adns_qf_owner;
-  op->sflags= 0;
-  op->resolver= 0; /* fixme default */
-  op->reverseany= 0;
-  rc= parse_options(ip, queryopts_objc,queryopts_objv, query_optioninfos,op);
+  op.aflags= adns_qf_owner;
+  op.sflags= 0;
+  op.resolver= 0;
+  op.reverseany= 0;
+  rc= parse_options(ip, queryopts_objc,queryopts_objv, query_optioninfos,&op);
   if (rc) return rc;
 
-  if (op->reverseany || (op->sflags & oisf_reverse)) {
+  if (!op.resolver) {
+    op.resolver= default_resolver(ip);
+    if (!op.resolver) {
+      optparse_blank(&res_op);
+      rc= create_resolver(ip, &res_op, &op.resolver);
+      if (rc) return rc;
+
+      Tcl_SetAssocData(ip, ASSOC_DEFAULTRES,
+		       destroy_resolver_defcb, op.resolver);
+    }
+  }
+
+  *res_r= op.resolver;
+  
+  if (op.reverseany || (op.sflags & oisf_reverse)) {
     const int *af;
     for (af=aftry; af < af + sizeof(af)/sizeof(*af); af++) {
       memset(&sa,0,sizeof(sa));
@@ -359,24 +489,25 @@ static int query_submit(Tcl_Interp *ip,
       r= inet_pton(*af,domain,&sa);
       if (!r) goto af_found;
     }
-    return staticerr(ip,"invalid address for adns reverse submit","");
+    return cht_staticerr(ip,"invalid address for adns reverse submit",
+			 "ADNS REVERSE INVALID");
   af_found:;
   }
 
-  ads= op->resolver->ads;
+  ads= op.resolver->ads;
 
-  if (op->reverseany) {
-    ec= adns_submit_reverse_any(ads, &sa, op->reverseany,
-				type->number, op->aflags, context, aqu_r);
-  } else if (op->sflags & oisf_reverse) {
+  if (op.reverseany) {
+    ec= adns_submit_reverse_any(ads, &sa, op.reverseany,
+				type->number, op.aflags, context, aqu_r);
+  } else if (op.sflags & oisf_reverse) {
     ec= adns_submit_reverse(ads, &sa,
-			    type->number, op->aflags, context, aqu_r);
+			    type->number, op.aflags, context, aqu_r);
   } else {
     ec= adns_submit(ads, domain,
-		    type->number, op->aflags, context, aqu_r);
+		    type->number, op.aflags, context, aqu_r);
   }
   if (ec)
-    return posixerr(ip,ec,"submit adns query");
+    return cht_posixerr(ip,ec,"submit adns query");
 
   return TCL_OK;
 }
@@ -386,10 +517,10 @@ static int query_submit(Tcl_Interp *ip,
 
 static void make_resultstatus(Tcl_Interp *ip, adns_status status,
 			      Tcl_Obj *results[RESULTSTATUS_LLEN]) {
-  results[0]= ret_string(ip, adns_errtypeabbrev(status));
-  results[1]= ret_int(ip, status);
-  results[2]= ret_string(ip, adns_errabbrev(status));
-  results[3]= ret_string(ip, adns_strerror(status));
+  results[0]= cht_ret_string(ip, adns_errtypeabbrev(status));
+  results[1]= cht_ret_int(ip, status);
+  results[2]= cht_ret_string(ip, adns_errabbrev(status));
+  results[3]= cht_ret_string(ip, adns_strerror(status));
 }
 
 static Tcl_Obj *make_resultrdata(Tcl_Interp *ip, adns_answer *answer) {
@@ -404,7 +535,7 @@ static Tcl_Obj *make_resultrdata(Tcl_Interp *ip, adns_answer *answer) {
        i++, datap += rrsz) {
     st= adns_rr_info(answer->type, 0,0, &rrsz, datap, &rdatastring);
     assert(!st);
-    rdata[i]= ret_string(ip, rdatastring);
+    rdata[i]= cht_ret_string(ip, rdatastring);
     free(rdatastring);
   }
   rl= Tcl_NewListObj(answer->nrrs, rdata);
@@ -417,8 +548,8 @@ static void make_resultlist(Tcl_Interp *ip, adns_answer *answer,
 
   make_resultstatus(ip, answer->status, results);
   assert(RESULTSTATUS_LLEN==4);
-  results[4]= ret_string(ip, answer->owner);
-  results[5]= ret_string(ip, answer->cname ? answer->cname : "");
+  results[4]= cht_ret_string(ip, answer->owner);
+  results[5]= cht_ret_string(ip, answer->cname ? answer->cname : "");
   results[6]= make_resultrdata(ip, answer);
 }
 
@@ -428,22 +559,20 @@ static int synch(Tcl_Interp *ip, const AdnsTclRRTypeInfo *rrtype,
 		 const char *domain,
 		 int objc, Tcl_Obj *const *objv, adns_answer **answer_r) {
   adns_query aqu;
-  OptionParse op;
   Resolver *res;
   int rc, ec;
   
-  rc= query_submit(ip,rrtype,domain,objc,objv,&aqu,0,&op);
+  rc= query_submit(ip,rrtype,domain,objc,objv,&aqu,0,&res);
   if (rc) return rc;
 
-  res= op.resolver;
   ec= adns_wait(res->ads,&aqu,answer_r,0);
   assert(!ec);
 
-  asynch_check(res);
+  asynch_perturbed(res);
   return TCL_OK;
 }
 
-int do_adns_lookup(ClientData cd, Tcl_Interp *ip,
+int cht_do_adns_lookup(ClientData cd, Tcl_Interp *ip,
 		   const AdnsTclRRTypeInfo *rrtype,
 		   const char *domain,
 		   int objc, Tcl_Obj *const *objv,
@@ -464,7 +593,7 @@ int do_adns_lookup(ClientData cd, Tcl_Interp *ip,
   return TCL_OK;
 }
 
-int do_adns_synch(ClientData cd, Tcl_Interp *ip,
+int cht_do_adns_synch(ClientData cd, Tcl_Interp *ip,
 		  const AdnsTclRRTypeInfo *rrtype,
 		  const char *domain,
 		  int objc, Tcl_Obj *const *objv,
@@ -490,11 +619,13 @@ struct Query {
   Tcl_Obj *xargs;
 };
 
+static void asynch_check_now(Resolver *res);
+
 static void asynch_timerhandler(void *res_v) {
   Resolver *res= res_v;
   res->timertoken= 0;
   adns_processtimeouts(res->ads,0);
-  asynch_check(res);
+  asynch_check_now(res);
 }
 
 static void asynch_filehandler(void *res_v, int mask) {
@@ -503,10 +634,12 @@ static void asynch_filehandler(void *res_v, int mask) {
   
   ec= adns_processany(res->ads);
   if (ec) adns_globalsystemfailure(res->ads);
-  asynch_check(res);
+  asynch_check_now(res);
 }
 
-static void asynch_sethandlers(Resolver *res, int shutdown) {
+static void asynch_sethandlers_generic(Resolver *res,
+				       int shutdown /*from _cancelhandlers*/,
+				       int immediate /*from _perturbed*/) {
   fd_set want[3];
   int maxfd;
   struct timeval tv_buf, *timeout;
@@ -528,13 +661,21 @@ static void asynch_sethandlers(Resolver *res, int shutdown) {
 	if (FD_ISSET(fd, &want[0])) mask |= TCL_READABLE;
 	if (FD_ISSET(fd, &want[1])) mask |= TCL_WRITABLE;
 	if (FD_ISSET(fd, &want[2])) mask |= TCL_EXCEPTION;
-	if (mask) Tcl_CreateFileHandler(fd,mask,asynch_filehandler,res);
-	else Tcl_DeleteFileHandler(fd);
+	if (mask) {
+	  Tcl_CreateFileHandler(fd,mask,asynch_filehandler,res);
+	  FD_SET(fd, &res->handling[i]);
+	} else {
+	  Tcl_DeleteFileHandler(fd);
+	  FD_CLR(fd, &res->handling[i]);
+	}
       }
+  res->maxfd= maxfd;
 
   Tcl_DeleteTimerHandler(res->timertoken);
 
-  if (timeout) {
+  if (immediate) {
+    res->timertoken= Tcl_CreateTimerHandler(0,asynch_timerhandler,res);
+  } else if (timeout) {
     int milliseconds;
 
     if (timeout->tv_sec >= INT_MAX/1000 - 1)
@@ -548,7 +689,17 @@ static void asynch_sethandlers(Resolver *res, int shutdown) {
   }
 }
 
-static void asynch_check(Resolver *res) {
+static void asynch_sethandlers(Resolver *res) {
+  asynch_sethandlers_generic(res,0,0);
+}
+static void asynch_cancelhandlers(Resolver *res) {
+  asynch_sethandlers_generic(res,1,0);
+}
+static void asynch_perturbed(Resolver *res) {
+  asynch_sethandlers_generic(res,0,1);
+}
+
+static void asynch_check_now(Resolver *res) {
   Tcl_Interp *interp= res->interp;
   adns_query aqu;
   adns_answer *answer;
@@ -558,7 +709,14 @@ static void asynch_check(Resolver *res) {
   int ec;
   Tcl_Obj *results[RESULTLIST_LLEN];
 
+  Tcl_Preserve(res);
+  
   for (;;) {
+    if (!res->ads) { /* oh, it has been destroyed! */
+      Tcl_Release(res);
+      return;
+    }
+
     aqu= 0;
     ec= adns_check(res->ads, &aqu, &answer, &query_v);
     if (ec==ESRCH || ec==EAGAIN) break;
@@ -566,7 +724,7 @@ static void asynch_check(Resolver *res) {
     query= query_v;
 
     query->aqu= 0;
-    tabledataid_disposing(interp, query, &adnstcl_queries);
+    cht_tabledataid_disposing(interp, query, &adnstcl_queries);
 
     si= (!answer->status ? &query->on_yes
 	 : answer->status > adns_s_max_tempfail ? &query->on_no
@@ -574,39 +732,40 @@ static void asynch_check(Resolver *res) {
 
     make_resultlist(interp, answer, results);
     free(answer);
-    scriptinv_invoke(si, RESULTLIST_LLEN, results);
+    cht_scriptinv_invoke(si, RESULTLIST_LLEN, results);
     asynch_query_dispose(interp, query);
   }
 
-  asynch_sethandlers(res,0);
+  asynch_sethandlers(res);
+
+  Tcl_Release(res);
 }
     
-int do_adns_asynch(ClientData cd, Tcl_Interp *ip,
+int cht_do_adns_asynch(ClientData cd, Tcl_Interp *ip,
 		   Tcl_Obj *on_yes, Tcl_Obj *on_no,
 		   Tcl_Obj *on_fail, Tcl_Obj *xargs,
 		   const AdnsTclRRTypeInfo *rrtype, const char *domain,
 		   int objc, Tcl_Obj *const *objv, void **result) {
   Query *query;
   int rc;
-  Resolver *res=0;
-  OptionParse op;
+  Resolver *res= 0;
   
   query= TALLOC(sizeof(*query));
   query->ix= -1;
   query->aqu= 0;
-  scriptinv_init(&query->on_yes);
-  scriptinv_init(&query->on_no);
-  scriptinv_init(&query->on_fail);
+  cht_scriptinv_init(&query->on_yes);
+  cht_scriptinv_init(&query->on_no);
+  cht_scriptinv_init(&query->on_fail);
   query->xargs= 0;
 
-  rc= query_submit(ip,rrtype,domain,objc,objv,&query->aqu,query,&op);
+  rc= query_submit(ip,rrtype,domain,objc,objv,&query->aqu,query,&query->res);
   if (rc) goto x_rc;
 
-  res= op.resolver;
+  res= query->res;
 
-  rc= scriptinv_set_xa(&query->on_yes, ip,on_yes);   if (rc) goto x_rc;
-  rc= scriptinv_set_xa(&query->on_no,  ip,on_no);    if (rc) goto x_rc;
-  rc= scriptinv_set_xa(&query->on_fail,ip,on_fail);  if (rc) goto x_rc;
+  rc= cht_scriptinv_set(&query->on_yes, ip,on_yes, xargs);  if (rc) goto x_rc;
+  rc= cht_scriptinv_set(&query->on_no,  ip,on_no,  xargs);  if (rc) goto x_rc;
+  rc= cht_scriptinv_set(&query->on_fail,ip,on_fail,xargs);  if (rc) goto x_rc;
   query->xargs= xargs;
   Tcl_IncrRefCount(xargs);
   *result= query;
@@ -615,23 +774,23 @@ int do_adns_asynch(ClientData cd, Tcl_Interp *ip,
 
  x_rc:
   if (query) asynch_query_dispose(ip, query);
-  if (res) asynch_sethandlers(res,0);
+  if (res) asynch_perturbed(res);
   return rc;
 }
 
-int do_adns_asynch_cancel(ClientData cd, Tcl_Interp *ip, void *query_v) {
+int cht_do_adns_asynch_cancel(ClientData cd, Tcl_Interp *ip, void *query_v) {
   Query *query= query_v;
   Resolver *res= query->res;
   asynch_query_dispose(ip, query);
-  asynch_sethandlers(res,0);
+  asynch_perturbed(res);
   return TCL_OK;
 }
 
 static void asynch_query_dispose(Tcl_Interp *interp, Query *query) {
-  tabledataid_disposing(interp, query, &adnstcl_queries);
-  scriptinv_cancel(&query->on_yes);
-  scriptinv_cancel(&query->on_no);
-  scriptinv_cancel(&query->on_fail);
+  cht_tabledataid_disposing(interp, query, &adnstcl_queries);
+  cht_scriptinv_cancel(&query->on_yes);
+  cht_scriptinv_cancel(&query->on_no);
+  cht_scriptinv_cancel(&query->on_fail);
   if (query->xargs) Tcl_DecrRefCount(query->xargs);
   if (query->aqu) adns_cancel(query->aqu);
   TFREE(query);
@@ -644,3 +803,16 @@ static void destroy_query_idtabcb(Tcl_Interp *interp, void *query_v) {
 const IdDataSpec adnstcl_queries= {
   "adns", "adns-query-table", destroy_query_idtabcb
 };
+
+/*---------- main hooks for tcl ----------*/
+
+int cht_do_adnstoplevel_adns(ClientData cd, Tcl_Interp *ip,
+		      const Adns_SubCommand *subcmd,
+		      int objc, Tcl_Obj *const *objv) {
+  return subcmd->func(0,ip,objc,objv);
+}
+
+extern int Chiark_tcl_adns_Init(Tcl_Interp *ip); /* called by Tcl's "load" */
+int Chiark_tcl_adns_Init(Tcl_Interp *ip) {
+  return cht_initextension(ip, cht_adnstoplevel_entries, 0);
+}