hostmux patch

[James A Morrison]

Hey, 

  Guess what?  It's time for my weekly patch ;)  This stuff is mostly
out of the glibc manual ;)

2002-03-03  James A. Morrison  <ja2morri@uwaterloo.ca>

         * mux.c (lookup_host): removed arbitrary limit on host name size.

Index: mux.c
===================================================================
RCS file: /cvsroot/hurd/hurd/hostmux/mux.c,v
retrieving revision 1.7
diff -u -r1.7 mux.c
--- mux.c       1 Aug 2001 13:00:55 -0000       1.7
+++ mux.c       4 Mar 2002 00:49:29 -0000
@@ -324,10 +324,10 @@
 lookup_host (struct hostmux *mux, const char *host, struct node **node)
 {
   int was_cached;
-  int h_err;
+  int h_err, size = 256;
   struct hostent _he, *he;
   struct in_addr inet_addr;
-  char hostent_data[2048];     /* XXX what size should this be???? */
+  char *hostent_data; 
 
   rwlock_reader_lock (&mux->names_lock);
   was_cached = lookup_cached (mux, host, 0, node);
@@ -337,18 +337,53 @@
     return 0;
   else if (inet_aton (host, &inet_addr))
     {
-      if (gethostbyaddr_r ((char *)&inet_addr, sizeof inet_addr, AF_INET,
-                          &_he, hostent_data, sizeof hostent_data,
-                          &he, &h_err) == 0)
-       return lookup_hostent (mux, host, he, node);
+      int res = 0;
+      hostent_data = (char*)malloc(size);
+      if ( !hostent_data ) 
+       return ENOMEM;
+      while ( ( res = gethostbyaddr_r ((char *)&inet_addr, sizeof inet_addr, 
+                                      AF_INET, &_he, hostent_data, size, 
+                                      &he, &h_err) ) == ERANGE);
+      
+      {
+       free(hostent_data);
+
+       size *= 2;
+       hostent_data = (char*)malloc(size);
+       if ( !hostent_data )
+         return ENOMEM;
+
+      }       
+      free(hostent_data);
+
+      if ( res || he == NULL )
+       return ENOENT;
       else
+       return lookup_hostent (mux, host, he, node);
+    }
+  else 
+    {
+      int res = 0;
+      hostent_data = (char*)malloc(size);
+      if ( !hostent_data ) 
+       return ENOMEM;
+      while ( (res = gethostbyname_r (host, &_he, hostent_data, size,
+                                     &he, &h_err) ) == ERANGE )
+       {
+         free(hostent_data);
+         
+         size *= 2;
+         hostent_data = (char*)malloc(size);
+         if ( !hostent_data )
+           return ENOMEM; 
+       }
+      free(hostent_data);
+
+      if ( res || he == NULL )
        return ENOENT;
+      else
+       return lookup_hostent (mux, host, he, node);
     }
-  else if (gethostbyname_r (host, &_he, hostent_data, sizeof hostent_data,
-                           &he, &h_err) == 0)
-    return lookup_hostent (mux, host, he, node);
-  else
-    return ENOENT;
 }
 
 /* This should sync the entire remote filesystem.  If WAIT is set, return