X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~mdw/git/adns/blobdiff_plain/5c596e4d1958e60ffdf88aa8500581b94988cc5c..680d2a652d5185d75c206444e9e8db9b82b3121c:/src/parse.c?ds=inline

diff --git a/src/parse.c b/src/parse.c
index 2a9dd94..099deb7 100644
--- a/src/parse.c
+++ b/src/parse.c
@@ -1,4 +1,24 @@
-/**/
+/*
+ * parse.c
+ * - parsing assistance functions (mainly for domains inside datagrams)
+ */
+/*
+ *  This file is part of adns, which is Copyright (C) 1997, 1998 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"
 
@@ -26,132 +46,144 @@ int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len) {
   return 1;
 }
 
-adns_status adns__get_label(const byte *dgram, int dglen, int *max_io,
-			    int *cbyte_io, int *lablen_r, int *labstart_r,
-			    int *namelen_io) {
-  /* If succeeds, *lablen_r may be set to -1 to indicate truncation/overrun */
-  int max, cbyte, lablen, namelen;
+void adns__findlabel_start(findlabel_state *fls, adns_state ads,
+			   int serv, adns_query qu,
+			   const byte *dgram, int dglen, int max,
+			   int dmbegin, int *dmend_rlater) {
+  fls->ads= ads;
+  fls->qu= qu;
+  fls->serv= serv;
+  fls->dgram= dgram;
+  fls->dglen= dglen;
+  fls->max= max;
+  fls->cbyte= dmbegin;
+  fls->namelen= 0;
+  fls->dmend_r= dmend_rlater;
+}
 
-  max= *max_io;
-  cbyte= *cbyte_io;
-  
+adns_status adns__findlabel_next(findlabel_state *fls,
+				 int *lablen_r, int *labstart_r) {
+  int lablen, jumped;
+  const char *dgram;
+
+  jumped= 0;
+  dgram= fls->dgram;
   for (;;) {
-    if (cbyte+2 > max) goto x_truncated;
-    GET_W(cbyte,lablen);
+    if (fls->cbyte+2 > fls->dglen) goto x_truncated;
+    if (fls->cbyte+2 > fls->max) goto x_serverfaulty;
+    GET_W(fls->cbyte,lablen);
     if (!(lablen & 0x0c000)) break;
     if ((lablen & 0x0c000) != 0x0c000) return adns_s_unknownreply;
-    if (cbyte_io) { *cbyte_io= cbyte; cbyte_io= 0; }
-    cbyte= DNS_HDRSIZE+(lablen&0x3fff);
-    *max_io= max= dglen;
+    if (jumped++) {
+      adns__diag(fls->ads,fls->serv,fls->qu,"compressed datagram contains loop");
+      return adns_s_serverfaulty;
+    }
+    if (fls->dmend_r) *(fls->dmend_r)= fls->cbyte;
+    fls->cbyte= DNS_HDRSIZE+(lablen&0x3fff);
+    fls->dmend_r= 0; fls->max= fls->dglen+1;
   }
-  if (labstart_r) *labstart_r= cbyte;
   if (lablen) {
-    namelen= *namelen_io;
-    if (namelen) namelen++;
-    namelen+= lablen;
-    if (namelen > DNS_MAXDOMAIN) return adns_s_domaintoolong;
-    *namelen_io= namelen;
-    cbyte+= lablen;
-    if (cbyte > max) goto x_truncated;
+    if (fls->namelen) fls->namelen++;
+    fls->namelen+= lablen;
+    if (fls->namelen > DNS_MAXDOMAIN) return adns_s_domaintoolong;
+    fls->cbyte+= lablen;
+    if (fls->cbyte > fls->dglen) goto x_truncated;
+    if (fls->cbyte > fls->max) goto x_serverfaulty;
+  } else {
+    if (fls->dmend_r) *(fls->dmend_r)= fls->cbyte;
   }
-  if (cbyte_io) *cbyte_io= cbyte;
+  if (labstart_r) *labstart_r= fls->cbyte;
   *lablen_r= lablen;
   return adns_s_ok;
 
  x_truncated:
   *lablen_r= -1;
   return adns_s_ok;
+
+ x_serverfaulty: 
+  adns__diag(fls->ads,fls->serv,fls->qu,"label in domain runs beyond end of domain");
+  return adns_s_serverfaulty;
 }
 
-adns_status adns__get_domain_perm(adns_state ads, adns_query qu, int serv,
-				  const byte *dgram, int dglen,
-				  int *cbyte_io, int max, int *domainstart_r) {
-  /* Returns 0     for OK (*domainstart_r >=0) or truncated (*domainstart_r == -1)
-   *      or any other adns_s_* value.
-   */
-  int cbyte, sused, lablen, labstart, namelen, i, ch;
+adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu,
+			       vbuf *vb, int flags,
+			       const byte *dgram, int dglen, int *cbyte_io, int max) {
+  findlabel_state fls;
+  
+  int lablen, labstart, i, ch;
   adns_status st;
 
-  /* If we follow a pointer we set cbyte_io to 0 to indicate that
-   * we've lost our original starting and ending points; we don't
-   * put the end of the pointed-to thing into the original *cbyte_io.
-   */
-  cbyte= *cbyte_io;
-  sused= qu->ans.used;
-  namelen= 0;
+  adns__findlabel_start(&fls,ads, serv,qu, dgram,dglen,max, *cbyte_io,cbyte_io);
+  vb->used= 0;
   for (;;) {
-    st= adns__get_label(dgram,dglen,&max, &cbyte,&lablen,&labstart,&namelen);
+    st= adns__findlabel_next(&fls,&lablen,&labstart);
     if (st) return st;
-    if (lablen<0) goto x_truncated;
+    if (lablen<0) { vb->used=0; return adns_s_ok; }
     if (!lablen) break;
-    if (qu->ans.used != sused)
-      if (!adns__vbuf_append(&qu->ans,".",1)) return adns_s_nolocalmem;
-    if (qu->flags & adns_qf_anyquote) {
-      if (!vbuf__append_quoted1035(&qu->ans,dgram+labstart,lablen))
+    if (vb->used)
+      if (!adns__vbuf_append(vb,".",1)) return adns_s_nolocalmem;
+    if (flags & adns_qf_anyquote) {
+      if (!vbuf__append_quoted1035(vb,dgram+labstart,lablen))
 	return adns_s_nolocalmem;
     } else {
       if (!ctype_alpha(dgram[labstart])) return adns_s_invaliddomain;
-      for (i= cbyte+1; i<cbyte+lablen; i++) {
-	ch= dgram[cbyte];
+      for (i= labstart+1; i<labstart+lablen; i++) {
+	ch= dgram[i];
 	if (ch != '-' && !ctype_alpha(ch) && !ctype_digit(ch))
 	  return adns_s_invaliddomain;
       }
-      if (!adns__vbuf_append(&qu->ans,dgram+labstart,lablen))
+      if (!adns__vbuf_append(vb,dgram+labstart,lablen))
 	return adns_s_nolocalmem;
     }
   }
-  if (cbyte_io) *cbyte_io= cbyte;
-  if (!adns__vbuf_append(&qu->ans,"",1)) return adns_s_nolocalmem;
-  *domainstart_r= sused;
+  if (!adns__vbuf_append(vb,"",1)) return adns_s_nolocalmem;
   return adns_s_ok;
-
- x_truncated:
-  *domainstart_r= -1;
-  return cbyte_io ? -1 : adns_s_serverfaulty;
-}
-    
-adns_status adns__get_domain_temp(adns_state ads, adns_query qu, int serv,
-				  const byte *dgram, int dglen,
-				  int *cbyte_io, int max, int *domainstart_r) {
-  int sused;
-  adns_status st;
-
-  sused= qu->ans.used;
-  st= adns__get_domain_perm(ads,qu,serv,dgram,dglen,cbyte_io,max,domainstart_r);
-  qu->ans.used= sused;
-  return st;
 }
-
-adns_status adns__get_rr_temp(adns_state ads, adns_query qu, int serv,
-			      const byte *dgram, int dglen, int *cbyte_io,
-			      int *type_r, int *class_r, int *rdlen_r, int *rdstart_r,
-			      const byte *eo_dgram, int eo_dglen, int eo_cbyte,
-			      int *eo_matched_r) {
-  /* _s_ok can have *type_r == -1 and other output invalid, for truncation
-   * type_r and class_r must be !0, other _r may be 0.
-   * eo_dgram==0 for no comparison, otherwise all eo_ must be valid.
+	
+static adns_status findrr_intern(adns_query qu, int serv,
+				 const byte *dgram, int dglen, int *cbyte_io,
+				 int *type_r, int *class_r, int *rdlen_r, int *rdstart_r,
+				 const byte *eo_dgram, int eo_dglen, int eo_cbyte,
+				 int *eo_matched_r) {
+  /* Like adns__findrr_checked, except that the datagram to compare
+   * with can be specified explicitly.
+   *
+   * If the caller thinks they know what the owner of the RR ought to
+   * be they can pass in details in eo_*: this is another (or perhaps
+   * the same datagram), and a pointer to where the putative owner
+   * starts in that datagram.  In this case *eo_matched_r will be set
+   * to 1 if the datagram matched or 0 if it did not.  Either
+   * both eo_dgram and eo_matched_r must both be non-null, or they
+   * must both be null (in which case eo_dglen and eo_cbyte will be ignored).
+   * The eo datagram and contained owner domain MUST be valid and
+   * untruncated.
    */
-  int cbyte, tmp, rdlen, mismatch;
-  int max, lablen, labstart, namelen, ch;
-  int eo_max, eo_lablen, eo_labstart, eo_namelen, eo_ch;
+  findlabel_state fls, eo_fls;
+  int cbyte;
+  
+  int tmp, rdlen, mismatch;
+  int lablen, labstart, ch;
+  int eo_lablen, eo_labstart, eo_ch;
   adns_status st;
 
   cbyte= *cbyte_io;
-  mismatch= eo_dgram ? 1 : 0;
 
-  namelen= 0; eo_namelen= 0;
-  max= dglen; eo_max= eo_dglen;
+  adns__findlabel_start(&fls,qu->ads, serv,qu, dgram,dglen,dglen,cbyte,&cbyte);
+  if (eo_dgram) {
+    adns__findlabel_start(&eo_fls,qu->ads, -1,0, eo_dgram,eo_dglen,eo_dglen,eo_cbyte,0);
+    mismatch= 0;
+  } else {
+    mismatch= 1;
+  }
+  
   for (;;) {
-    st= adns__get_label(dgram,dglen,&max,
-			&cbyte,&lablen,&labstart,&namelen);
+    st= adns__findlabel_next(&fls,&lablen,&labstart);
     if (st) return st;
     if (lablen<0) goto x_truncated;
 
     if (!mismatch) {
-      st= adns__get_label(eo_dgram,eo_dglen,&eo_max,
-			  &eo_cbyte,&eo_lablen,&eo_labstart,&eo_namelen);
-      if (st) return st;
-      assert(eo_lablen>=0);
+      st= adns__findlabel_next(&eo_fls,&eo_lablen,&eo_labstart);
+      assert(!st); assert(eo_lablen>=0);
       if (lablen != eo_lablen) mismatch= 1;
       while (!mismatch && lablen-- > 0) {
 	ch= dgram[labstart++]; if (ctype_alpha(ch)) ch &= ~32;
@@ -177,3 +209,27 @@ adns_status adns__get_rr_temp(adns_state ads, adns_query qu, int serv,
   *type_r= -1;
   return 0;;
 }
+
+adns_status adns__findrr(adns_query qu, int serv,
+			 const byte *dgram, int dglen, int *cbyte_io,
+			 int *type_r, int *class_r, int *rdlen_r, int *rdstart_r,
+			 int *ownermatchedquery_r) {
+  if (!ownermatchedquery_r) {
+    return findrr_intern(qu,serv,
+			 dgram,dglen,cbyte_io,
+			 type_r,class_r,rdlen_r,rdstart_r,
+			 0,0,0, 0);
+  } else if (!qu->cname_dgram) {
+    return findrr_intern(qu,serv,
+			 dgram,dglen,cbyte_io,
+			 type_r,class_r,rdlen_r,rdstart_r,
+			 qu->query_dgram,qu->query_dglen,DNS_HDRSIZE,
+			 ownermatchedquery_r);
+  } else {
+    return findrr_intern(qu,serv,
+			 dgram,dglen,cbyte_io,
+			 type_r,class_r,rdlen_r,rdstart_r,
+			 qu->cname_dgram,qu->cname_dglen,qu->cname_begin,
+			 ownermatchedquery_r);
+  }
+}