Git conversion: Make reactos the root directory, move rosapps, rostests, wallpapers...

[reactos.git] / sdk / lib / dnslib / hostent.c

diff --git a/sdk/lib/dnslib/hostent.c b/sdk/lib/dnslib/hostent.c
new file mode 100644 (file)
index 0000000..f7c9e64
--- /dev/null
+++ b/sdk/lib/dnslib/hostent.c
@@ -0,0 +1,97 @@
+/*
+ * COPYRIGHT:   See COPYING in the top level directory
+ * PROJECT:     ReactOS DNS Shared Library
+ * FILE:        lib/dnslib/hostent.c
+ * PURPOSE:     Functions for dealing with Host Entry structures
+ */
+
+/* INCLUDES ******************************************************************/
+#include "precomp.h"
+
+/* DATA **********************************************************************/
+
+/* FUNCTIONS *****************************************************************/
+
+PHOSTENT
+WINAPI
+Hostent_Init(IN PVOID *Buffer,
+             IN WORD AddressFamily,
+             IN ULONG AddressSize,
+             IN ULONG AddressCount,
+             IN ULONG AliasCount)
+{
+    PHOSTENT Hostent;
+    ULONG_PTR BufferPosition = (ULONG_PTR)*Buffer;
+
+    /* Align the hostent on the buffer's 4 byte boundary */
+    BufferPosition += 3 & ~3;
+
+    /* Set up the basic data */
+    Hostent = (PHOSTENT)BufferPosition;
+    Hostent->h_length = (WORD)AddressSize;
+    Hostent->h_addrtype = AddressFamily;
+
+    /* Put aliases after Hostent */
+    Hostent->h_aliases = (PCHAR*)((ULONG_PTR)(Hostent + 1) & ~3);
+
+    /* Zero it out */
+    RtlZeroMemory(Hostent->h_aliases, AliasCount * sizeof(PCHAR));
+
+    /* Put addresses after aliases */
+    Hostent->h_addr_list = (PCHAR*)
+                           ((ULONG_PTR)Hostent->h_aliases +
+                            (AliasCount * sizeof(PCHAR)) + sizeof(PCHAR));
+
+    /* Update the location */
+    BufferPosition = (ULONG_PTR)Hostent->h_addr_list +
+                     ((AddressCount * sizeof(PCHAR)) + sizeof(PCHAR));
+
+    /* Send it back */
+    *Buffer = (PVOID)BufferPosition;
+
+    /* Return the hostent */
+    return Hostent;
+}
+
+VOID
+WINAPI
+Dns_PtrArrayToOffsetArray(PCHAR *List,
+                          ULONG_PTR Base)
+{
+    /* Loop every pointer in the list */
+    do 
+    {
+        /* Update the pointer */
+        *List = (PCHAR)((ULONG_PTR)*List - Base);
+    } while(*List++);
+}
+
+VOID
+WINAPI
+Hostent_ConvertToOffsets(IN PHOSTENT Hostent)
+{
+    /* Do we have a name? */
+    if (Hostent->h_name)
+    {
+        /* Update it */
+        Hostent->h_name -= (ULONG_PTR)Hostent;
+    }
+
+    /* Do we have aliases? */
+    if (Hostent->h_aliases)
+    {
+        /* Update the pointer */
+        Hostent->h_aliases -= (ULONG_PTR)Hostent;
+
+        /* Fix them up */
+        Dns_PtrArrayToOffsetArray(Hostent->h_aliases, (ULONG_PTR)Hostent);
+    }
+
+    /* Do we have addresses? */
+    if (Hostent->h_addr_list)
+    {
+        /* Fix them up */
+        Dns_PtrArrayToOffsetArray(Hostent->h_addr_list, (ULONG_PTR)Hostent);
+    }
+}
+