Changeset 2827 for trunk/kLdr/kLdrMod.c

Timestamp:

Oct 22, 2006, 8:05:28 PM (19 years ago)

Author:

bird

Message:

image format headers.

File:

• trunk/kLdr/kLdrMod.c (modified) (2 diffs)

trunk/kLdr/kLdrMod.c

@@ -32 +32 @@
 #include "kLdrHlp.h"
 #include "kLdrInternal.h"
+#include "kLdrModMZ.h"
+#if 1 /* testing headers */
+# include "kLdrModPE.h"
+//# include "kLdrModLX.h"
+# include "kLdrModELF32.h"
+# include "kLdrModELF64.h"
+#endif
 
 
+/**
+ * Open a executable image from a file provider instance.
+ *
+ * @returns 0 on success and *ppMod pointing to a module instance.
+ *          On failure, a non-zero OS specific error code is returned.
+ * @param   pRdr            The file provider instance to use.
+ *                          On success, the ownership of the instance is taken by the
+ *                          module and the caller must not ever touch it again.
+ *                          (The instance is not closed on failure, the call has to do that.)
+ * @param   ppMod           Where to store the module handle.
+ */
+int kLdrModOpenFromRdr(PKLDRRDR pRdr, PPKLDRMOD ppMod)
+{
+    union
+    {
+        uint32_t    u32;
+        uint16_t    u16;
+        uint16_t    au16[2];
+        uint8_t     au8[4];
+    }       u;
+    off_t   offHdr = 0;
+    int     rc;
+
+    /*
+     * Try figure out what kind of image this is.
+     * Always read the 'new header' if we encounter MZ.
+     */
+    rc = kLdrRdrRead(pRdr, &u, sizeof(u), 0);
+    if (rc)
+        return rc;
+    if (    u.u16 == IMAGE_DOS_SIGNATURE
+        &&  kLdrRdrSize(pRdr) > sizeof(IMAGE_DOS_HEADER))
+    {
+        rc = kLdrRdrRead(pRdr, &u, sizeof(u.u32), KLDR_OFFSETOF(IMAGE_DOS_HEADER, e_lfanew));
+        if (rc)
+            return rc;
+        if ((off_t)u.u32 < kLdrRdrSize(pRdr))
+        {
+            offHdr = u.u32;
+            rc = kLdrRdrRead(pRdr, &u, sizeof(u.u32), offHdr);
+            if (rc)
+                return rc;
+        }
+        else
+            u.u16 = IMAGE_DOS_SIGNATURE;
+    }
+
+    /*
+     * Use the magic to select the appropriate image interpreter.
+     */
+    if (u.u16 == IMAGE_DOS_SIGNATURE)
+        return KLDR_ERR_MZ_NOT_SUPPORTED;
+    else if (u.u16 == IMAGE_NE_SIGNATURE)
+        return KLDR_ERR_NE_NOT_SUPPORTED;
+    else if (u.u16 == IMAGE_LX_SIGNATURE)
+        return KLDR_ERR_LX_NOT_SUPPORTED;
+    else if (u.u16 == IMAGE_LE_SIGNATURE)
+        return KLDR_ERR_LE_NOT_SUPPORTED;
+    else if (u.u32 == IMAGE_NT_SIGNATURE)
+        return KLDR_ERR_PE_NOT_SUPPORTED;
+    else if (u.u32 == IMAGE_ELF_SIGNATURE)
+        return KLDR_ERR_ELF_NOT_SUPPORTED;
+    return KLDR_ERR_UNKNOWN_FORMAT;
+}
+
+
+/**
+ * Open a executable image by file name.
+ *
+ * @returns 0 on success and *ppMod pointing to a module instance.
+ *          On failure, a non-zero OS specific error code is returned.
+ * @param   pszFilename     The filename to open.
+ * @param   ppMod           Where to store the module handle.
+ */
 int kLdrModOpen(const char *pszFilename, PPKLDRMOD ppMod)
 {
@@ -39 +120 @@
      * Open the file using a bit provider.
      */
-
-
+    PKLDRRDR pRdr;
+    int rc = kLdrRdrOpen(&pRdr, pszFilename);
+    if (!rc)
+    {
+        rc = kLdrModOpenFromRdr(pRdr, ppMod);
+        if (!rc)
+            return 0;
+       kLdrRdrClose(pRdr);
+    }
+    return rc;
 }