[DHCPSVC]: It's a service, move it in the correct directory.

[reactos.git] / reactos / base / services / dhcpcsvc / dhcp / hash.c

diff --git a/reactos/base/services/dhcpcsvc/dhcp/hash.c b/reactos/base/services/dhcpcsvc/dhcp/hash.c
new file mode 100644 (file)
index 0000000..6bfa8c3
--- /dev/null
+++ b/reactos/base/services/dhcpcsvc/dhcp/hash.c
@@ -0,0 +1,165 @@
+/* hash.c
+
+   Routines for manipulating hash tables... */
+
+/*
+ * Copyright (c) 1995, 1996, 1997, 1998 The Internet Software Consortium.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of The Internet Software Consortium nor the names
+ *    of its contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
+ * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * This software has been written for the Internet Software Consortium
+ * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
+ * Enterprises.  To learn more about the Internet Software Consortium,
+ * see ``http://www.vix.com/isc''.  To learn more about Vixie
+ * Enterprises, see ``http://www.vix.com''.
+ */
+
+#define lint
+#ifndef lint
+static char copyright[] =
+"$Id: hash.c,v 1.9.2.3 1999/04/09 17:39:41 mellon Exp $ Copyright (c) 1995, 1996, 1997, 1998 The Internet Software Consortium.  All rights reserved.\n";
+#endif /* not lint */
+
+#include <rosdhcp.h>
+
+static __inline int do_hash PROTO ((unsigned char *, int, int));
+
+struct hash_table *new_hash ()
+{
+       struct hash_table *rv = new_hash_table (DEFAULT_HASH_SIZE);
+       if (!rv)
+               return rv;
+       memset (&rv -> buckets [0], 0,
+               DEFAULT_HASH_SIZE * sizeof (struct hash_bucket *));
+       return rv;
+}
+
+static __inline int do_hash (name, len, size)
+       unsigned char *name;
+       int len;
+       int size;
+{
+       register int accum = 0;
+       register unsigned char *s = name;
+       int i = len;
+       while (i--) {
+               /* Add the character in... */
+               accum += *s++;
+               /* Add carry back in... */
+               while (accum > 255) {
+                       accum = (accum & 255) + (accum >> 8);
+               }
+       }
+       return accum % size;
+}
+
+void add_hash (table, name, len, pointer)
+       struct hash_table *table;
+       int len;
+       unsigned char *name;
+       unsigned char *pointer;
+{
+       int hashno;
+       struct hash_bucket *bp;
+
+       if (!table)
+               return;
+       if (!len)
+               len = strlen ((char *)name);
+
+       hashno = do_hash (name, len, table -> hash_count);
+       bp = new_hash_bucket ();
+
+       if (!bp) {
+               warn ("Can't add %s to hash table.", name);
+               return;
+       }
+       bp -> name = name;
+       bp -> value = pointer;
+       bp -> next = table -> buckets [hashno];
+       bp -> len = len;
+       table -> buckets [hashno] = bp;
+}
+
+void delete_hash_entry (table, name, len)
+       struct hash_table *table;
+       int len;
+       unsigned char *name;
+{
+       int hashno;
+       struct hash_bucket *bp, *pbp = (struct hash_bucket *)0;
+
+       if (!table)
+               return;
+       if (!len)
+               len = strlen ((char *)name);
+
+       hashno = do_hash (name, len, table -> hash_count);
+
+       /* Go through the list looking for an entry that matches;
+          if we find it, delete it. */
+       for (bp = table -> buckets [hashno]; bp; bp = bp -> next) {
+               if ((!bp -> len &&
+                    !strcmp ((char *)bp -> name, (char *)name)) ||
+                   (bp -> len == len &&
+                    !memcmp (bp -> name, name, len))) {
+                       if (pbp) {
+                               pbp -> next = bp -> next;
+                       } else {
+                               table -> buckets [hashno] = bp -> next;
+                       }
+                       free_hash_bucket (bp, "delete_hash_entry");
+                       break;
+               }
+               pbp = bp;       /* jwg, 9/6/96 - nice catch! */
+       }
+}
+
+unsigned char *hash_lookup (table, name, len)
+       struct hash_table *table;
+       unsigned char *name;
+       int len;
+{
+       int hashno;
+       struct hash_bucket *bp;
+
+       if (!table)
+               return (unsigned char *)0;
+
+       if (!len)
+               len = strlen ((char *)name);
+
+       hashno = do_hash (name, len, table -> hash_count);
+
+       for (bp = table -> buckets [hashno]; bp; bp = bp -> next) {
+               if (len == bp -> len && !memcmp (bp -> name, name, len))
+                       return bp -> value;
+       }
+       return (unsigned char *)0;
+}