private syms starting to look good

1 files changed, 38 insertions, 6 deletions

diff --git a/lib/substitute.h b/lib/substitute.h
index d4287fb..20dc020 100644
--- a/lib/substitute.h
+++ b/lib/substitute.h
@@ -6,12 +6,11 @@
 #pragma once
 
 #include <stdlib.h>
+#include <stdint.h>
 
 // TODO add numbers
 enum {
     SUBSTITUTE_OK = 0,
-
-    SUBSTITUTE_ERR_MODULE_NOT_FOUND,
 };
 
 int substitute_hook_function(void *function, void *replacement, int options, void *result);
@@ -29,18 +28,51 @@ typedef struct nlist substitute_sym;
 #error No definition for substitute_sym!
 #endif
 
-/* Look up private symbols in an image currently loaded into the process.
+struct substitute_image {
+#ifdef __APPLE__
+    intptr_t slide;
+    void *dlhandle;
+    const void *image_header;
+#endif
+    /* possibly private fields... */
+};
+
+/* Look up an image currently loaded into the process.
  *
  * @filename the executable/library path (c.f. dyld(3) on Darwin)
+ * @return a handle, or NULL if the image wasn't found
+ */
+
+struct substitute_image *substitute_open_image(const char *filename);
+
+/* Release a handle opened with substitute_open_image.
+ *
+ * @handle a banana
+ */
+void substitute_close_image(struct substitute_image *handle);
+
+/* Look up private symbols in an image currently loaded into the process.
+ *
+ * @handle handle opened with substitute_open_image
  * @names an array of symbol names to search for
  * @nlist an array of substitute_sym *, one per name; on return, each entry
  * will be a pointer into the symbol table for that image, or NULL if the
  * symbol wasn't found
  * @count number of names
  *
- * @return SUBSTITUTE_OK or SUBSTITUTE_ERR_MODULE_NOT_FOUND
+ * @return SUBSTITUTE_OK (maybe errors in the future)
+ */
+int substitute_find_private_syms(struct substitute_image *handle,
+                                 const char **names,
+                                 substitute_sym **syms,
+                                 size_t count);
+
+/* Get a pointer corresponding to a loaded symbol table entry.
+ * @handle handle containing the symbol
+ * @sym symbol
+ * @return the pointer - on ARM, this can be | 1 for Thumb, like everything
+ * else
  */
-int substitute_find_syms(const char *filename, const char **names,
-                         substitute_sym **syms, size_t count);
+void *substitute_sym_to_ptr(struct substitute_image *handle, substitute_sym *sym);
 
 #endif /* 1 */