From: ian <ian>
Date: Thu, 25 Nov 2004 02:02:52 +0000 (+0000)
Subject: mask-map lookup seems to work
X-Git-Tag: debian/1.1.1~119
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=chiark-tcl.git;a=commitdiff_plain;h=d6fd8ff47e228354088d5be383a55d1d24099c36

mask-map lookup seems to work
---

diff --git a/base/chiark-tcl.h b/base/chiark-tcl.h
index 17a0594..4b4f4e8 100644
--- a/base/chiark-tcl.h
+++ b/base/chiark-tcl.h
@@ -66,7 +66,7 @@
  *               ulong VARNAME/VALUE         VALUE if bitfields2ul)
  *
  *  hbytes mask-map lookup MAP-VAR ADDRESS [DEFAULT]   => DATA
- *     error on missing default or if address too short
+ *     error on missing default or if any prefix longer than address
  *  hbytes mask-map amend MAP-VAR PREFIX PREFIX-LENGTH DATA
  *     a maskmap MAP is [list [list PREFIX PREFIX-LENGTH DATA]] sorted
  *     first by descending PREFIX-LENGTH and then by ascending PREFIX
@@ -86,6 +86,8 @@
  * HBYTES LENGTH MISMATCH              when blocks must be exactly same length
  * HBYTES SYNTAX                       supposed hex block had wrong syntax
  * HBYTES VALUE OVERFLOW               value to be conv'd to hex too big/long
+ * HBYTES MASKMAP NOMATCH              no addr/mask matches address for lookup
+ * HBYTES MASKMAP UNDERRUN             addr value for lookup is too short
  * HBYTES MASKMAP SYNTAX LLENGTH       value for mask-map entry not llength==3
  * HBYTES MASKMAP SYNTAX UNDERRUN      value for mask-map entry hex too short
  * HBYTES MASKMAP SYNTAX OVERRUN       actual mask-map entry hex too short
diff --git a/hbytes/hbytes.h b/hbytes/hbytes.h
index 17a0594..4b4f4e8 100644
--- a/hbytes/hbytes.h
+++ b/hbytes/hbytes.h
@@ -66,7 +66,7 @@
  *               ulong VARNAME/VALUE         VALUE if bitfields2ul)
  *
  *  hbytes mask-map lookup MAP-VAR ADDRESS [DEFAULT]   => DATA
- *     error on missing default or if address too short
+ *     error on missing default or if any prefix longer than address
  *  hbytes mask-map amend MAP-VAR PREFIX PREFIX-LENGTH DATA
  *     a maskmap MAP is [list [list PREFIX PREFIX-LENGTH DATA]] sorted
  *     first by descending PREFIX-LENGTH and then by ascending PREFIX
@@ -86,6 +86,8 @@
  * HBYTES LENGTH MISMATCH              when blocks must be exactly same length
  * HBYTES SYNTAX                       supposed hex block had wrong syntax
  * HBYTES VALUE OVERFLOW               value to be conv'd to hex too big/long
+ * HBYTES MASKMAP NOMATCH              no addr/mask matches address for lookup
+ * HBYTES MASKMAP UNDERRUN             addr value for lookup is too short
  * HBYTES MASKMAP SYNTAX LLENGTH       value for mask-map entry not llength==3
  * HBYTES MASKMAP SYNTAX UNDERRUN      value for mask-map entry hex too short
  * HBYTES MASKMAP SYNTAX OVERRUN       actual mask-map entry hex too short
diff --git a/maskmap/maskmap.c b/maskmap/maskmap.c
index 9c92810..f51dba4 100644
--- a/maskmap/maskmap.c
+++ b/maskmap/maskmap.c
@@ -171,11 +171,45 @@ int do_maskmap_amend(ClientData cd, Tcl_Interp *ip,
 }
 
 int do_maskmap_lookup(ClientData cd, Tcl_Interp *ip,
-		      Tcl_Obj *mapo, HBytes_Value addr, Tcl_Obj *def,
+		      Tcl_Obj *mapo, HBytes_Value addrhb, Tcl_Obj *def,
 		      Tcl_Obj **result) {
-  /*MaskMap_Var *map= (void*)&mapo->internalRep;*/
-  *result= Tcl_NewIntObj(42);
-  return TCL_OK; /*fixme*/
+  MaskMap_Value *mm= (void*)&mapo->internalRep;
+  MaskMap_Entry *search;
+  const Byte *addr= hbytes_data(&addrhb);
+  int addrbytes= hbytes_len(&addrhb);
+  int i, directbytes, leftoverbits;
+
+  search= mm->entries;
+  if (!search || search->prefixlen==-1) goto not_found;
+
+  /* longest masks are first, so we can test this once */
+  if (addrbytes < prefix_bytes(search->prefixlen))
+    return staticerr(ip, "address shorter than mask(s) in map",
+		     "HBYTES MASKMAP UNDERRUN");
+
+  for (i=0;
+       i < mm->allocd && search->prefixlen != -1;
+       i++, search++) {
+    directbytes= search->prefixlen / 8;
+    if (memcmp(search->prefix, addr, directbytes)) continue;
+
+    leftoverbits= search->prefixlen % 8;
+    if (leftoverbits)
+      if ((addr[directbytes] & (0xffu << leftoverbits))
+	  != search->prefix[directbytes])
+	continue;
+
+    /*found*/
+    *result= search->data;
+    return TCL_OK;
+  }
+
+ not_found:
+  if (!def)
+    return staticerr(ip, "address not found in mask-map",
+		     "HBYTES MASKMAP NOMATCH");
+  *result= def;
+  return TCL_OK;
 }
 
 /*---------- Tcl type and arg parsing functions ----------*/