Fixed library loading on Windows

Ticket: None
Changelog: None
Signed-off-by: Lars Erik Wik <[email protected]>

lib/Makefile.am

@@ -36,5 +36,6 @@ libleech_la_SOURCES = leech.c \
         table.h table.c \
         utils.h utils.c \
         sha1.h sha1.c \
+        module.h module.c \
         definitions.h
 libleech_la_LDFLAGS = -ldl -lm

lib/module.c

@@ -0,0 +1,77 @@
+#include "module.h"
+
+#include <stdlib.h>
+
+#if HAVE_DLFCN_H
+#include <dlfcn.h>
+#endif  // HAVE_DLFCN_H
+
+#if _WIN32
+#include <libloaderapi.h>
+#endif  // _WIN32
+
+#include "logger.h"
+
+void *LCH_ModuleLoad(const char *const path) {
+  LCH_LOG_DEBUG("Loading dynamic shared library '%s'", path);
+#if HAVE_DLFCN_H
+  void *handle = dlopen(path, RTLD_NOW);
+  if (handle == NULL) {
+    LCH_LOG_ERROR("Failed to load dynamic shared library '%s': %s", path,
+                  dlerror());
+    return NULL;
+  }
+  return handle;
+#elif defined(_WIN32)
+  void *handle = LoadLibraryA(path);
+  if (handle == NULL) {
+    LCH_LOG_ERROR("Failed to load dynamic shared library '%s': Error code %lu",
+                  path, GetLastError());
+  }
+  return handle;
+#else
+  LCH_LOG_ERROR("Failed to load dynamic shared library '%s'", path);
+  return NULL;
+#endif
+}
+
+void *LCH_ModuleGetSymbol(void *const handle, const char *const symbol) {
+  LCH_LOG_DEBUG("Obtaining address of symbol '%s'", symbol);
+#if HAVE_DLFCN_H
+  void *address = dlsym(handle, symbol);
+  if (address == NULL) {
+    LCH_LOG_ERROR("Failed to obtain address of symbol '%s': %s", symbol,
+                  dlerror());
+    return NULL;
+  }
+  return address;
+#elif defined(_WIN32)
+  void *address = GetProcAddress(handle, symbol);
+  if (address == NULL) {
+    LCH_LOG_ERROR("Failed to obtain address of symbol '%s': Error code %lu",
+                  symbol, GetLastError());
+  }
+  return address;
+#else
+  LCH_LOG_ERROR("Failed to obtain address of symbol '%s'", symbol);
+  return NULL;
+#endif
+}
+
+void LCH_ModuleDestroy(void *const handle) {
+  if (handle == NULL) {
+    return;
+  }
+#if HAVE_DLFCN_H
+  if (dlclose(handle) != 0) {
+    LCH_LOG_WARNING("Failed to release handle to dynamic shared library: %s",
+                    dlerror());
+  }
+#elif defined(_WIN32)
+  if (FreeLibrary(handle) == 0) {
+    LCH_LOG_WARNING(
+        "Failed to release handle to dynamic shared library: Error code %lu",
+        GetLastError());
+  }
+#endif
+}

lib/module.h

@@ -0,0 +1,12 @@
+#ifndef _LEECH_MODULE_H
+#define _LEECH_MODULE_H
+
+#include <stdbool.h>
+
+void *LCH_ModuleLoad(const char *path);
+
+void *LCH_ModuleGetSymbol(void *handle, const char *const symbol);
+
+void LCH_ModuleDestroy(void *handle);
+
+#endif  // _LEECH_MODULE_H