1 files changed, 104 insertions, 0 deletions
diff --git a/src/ldr/ntapi_ldr_revert_state_to_snapshot.c b/src/ldr/ntapi_ldr_revert_state_to_snapshot.c
new file mode 100644
index 0000000..2ca5087
--- /dev/null
+++ b/src/ldr/ntapi_ldr_revert_state_to_snapshot.c
@@ -0,0 +1,104 @@
+/********************************************************/
+/*  ntapi: Native API core library                      */
+/*  Copyright (C) 2013,2014,2015  Z. Gilboa             */
+/*  Released under GPLv2 and GPLv3; see COPYING.NTAPI.  */
+/********************************************************/
+
+#include <psxtypes/psxtypes.h>
+#include <pemagine/pemagine.h>
+#include <dalist/dalist.h>
+#include <ntapi/ntapi.h>
+#include "ntapi_impl.h"
+
+struct callback_ctx {
+	struct dalist_ex *		ldr_state_snapshot;
+	struct pe_ldr_tbl_entry *	ldr_tbl_entry;
+	void *				image_base;
+	uint32_t			load_count;
+	int32_t				status;
+};
+
+static int __cdecl __find_next_module_to_unload(
+	struct pe_ldr_tbl_entry *	ldr_tbl_entry,
+	enum pe_callback_reason		int_callback_reason,
+	void *				context)
+{
+	struct dalist_node *	node;
+	struct callback_ctx *	ctx;
+
+	ctx = (struct callback_ctx *)context;
+
+	if (int_callback_reason == PE_CALLBACK_REASON_ERROR) {
+		ctx->status = NT_STATUS_UNSUCCESSFUL;
+		return ctx->status;
+	} else if (int_callback_reason != PE_CALLBACK_REASON_ITEM) {
+		ctx->status = NT_STATUS_SUCCESS;
+		return 1;
+	} else if (!ldr_tbl_entry->dll_base) {
+		ctx->status = NT_STATUS_SUCCESS;
+		return 1;
+	}
+
+
+	ctx->status = dalist_get_node_by_key(
+		ctx->ldr_state_snapshot,
+		(struct dalist_node_ex **)&node,
+		(uintptr_t)ldr_tbl_entry->dll_base,
+		DALIST_NODE_TYPE_EXISTING,
+		0);
+
+	if (ctx->status != DALIST_OK)
+		return -1;
+	else if (node)
+		return 1;
+	else if (!ctx->image_base || (ldr_tbl_entry->load_count < ctx->load_count)) {
+			ctx->image_base = ldr_tbl_entry->dll_base;
+			ctx->load_count = ldr_tbl_entry->load_count;
+			ctx->ldr_tbl_entry = ldr_tbl_entry;
+	}
+
+	return 1;
+}
+
+
+int __cdecl __ntapi_ldr_revert_state_to_snapshot(
+	__in	struct dalist_ex * ldr_state_snapshot)
+{
+	struct callback_ctx	ctx;
+	uint32_t		i;
+
+	if (!ldr_state_snapshot->free && !ldr_state_snapshot->memfn_ptr)
+		return NT_STATUS_BUFFER_TOO_SMALL;
+
+	ctx.ldr_state_snapshot = ldr_state_snapshot;
+	ctx.image_base = (void *)0;
+	ctx.load_count = 0;
+
+	pe_enum_modules_in_load_order(
+		__find_next_module_to_unload,
+		&ctx);
+
+	while ((ctx.image_base) && (ctx.status == NT_STATUS_SUCCESS)) {
+			if (ctx.load_count == 0xffff) {
+				ctx.load_count = 1;
+				ctx.ldr_tbl_entry->load_count = 1;
+				ctx.ldr_tbl_entry->entry_point = (void *)0;
+				ctx.ldr_tbl_entry->flags = 0;
+			}
+
+			for (i=0; i<ctx.load_count; i++)
+				__ntapi->ldr_unload_dll(ctx.image_base);
+
+			__ntapi->zw_unmap_view_of_section(
+				NT_CURRENT_PROCESS_HANDLE,
+				ctx.image_base);
+		ctx.image_base = (void *)0;
+		ctx.load_count = 0;
+
+		pe_enum_modules_in_load_order(
+			__find_next_module_to_unload,
+			&ctx);
+	}
+
+	return ctx.status;
+}