module load: attempt to load modules from /vendor

Use TW_LOAD_VENDOR_MODULES := "module1.ko module2.ko modulen.ko"
in BoardConfig to have TWRP attempt to load kernel modules during
startup. For fastboot ramdisks, TWRP will attempt to load from
the ramdisk from /vendor/lib/modules. You can have the build
system copy the modules to
$(TARGET_RECOVERY_ROOT_OUT)/vendor/lib/modules/1.1
Otherwise in recovery in boot mode, TWRP will attempt the following:
check /lib/modules (ramdisk vendor_boot)
check /lib/modules/N.N (ramdisk vendor_boot)
check /lib/modules/N.N-gki (ramdisk vendor_boot)
check /vendor/lib/modules (ramdisk)
check /vendor/lib/modules/1.1 (ramdisk prebuilt modules)
check /vendor/lib/modules/N.N (vendor mounted)
check /vendor/lib/modules/N.N-gki (vendor mounted)

Change-Id: I2dccf199e37d47cb7a7e79b0e11026d67b4e3186
diff --git a/kernel_module_loader.cpp b/kernel_module_loader.cpp
new file mode 100644
index 0000000..fd24a91
--- /dev/null
+++ b/kernel_module_loader.cpp
@@ -0,0 +1,121 @@
+#include "kernel_module_loader.hpp"
+
+bool KernelModuleLoader::Load_Vendor_Modules(BOOT_MODE mode) {
+    // check /lib/modules (ramdisk vendor_boot)
+    // check /lib/modules/N.N (ramdisk vendor_boot)
+    // check /lib/modules/N.N-gki (ramdisk vendor_boot)
+    // check /vendor/lib/modules (ramdisk)
+    // check /vendor/lib/modules/1.1 (ramdisk prebuilt modules)
+    // check /vendor/lib/modules/N.N (vendor mounted)
+    // check /vendor/lib/modules/N.N-gki (vendor mounted)
+
+    LOGINFO("Attempting to load modules\n");
+    std::string vendor_base_dir(VENDOR_MODULE_DIR);
+    std::string base_dir(VENDOR_BOOT_MODULE_DIR);
+    std::vector<std::string> module_dirs;
+    std::vector<std::string> vendor_module_dirs;
+
+    TWPartition* ven = PartitionManager.Find_Partition_By_Path("/vendor");
+    vendor_module_dirs.push_back(VENDOR_MODULE_DIR);
+    vendor_module_dirs.push_back(vendor_base_dir + "/1.1");
+
+    module_dirs.push_back(base_dir);
+
+    struct utsname uts;
+    if (uname(&uts)) {
+        LOGERR("Unable to query kernel for version info\n");
+    }
+
+    std::string rls(uts.release);
+    std::vector<std::string> release = TWFunc::split_string(rls, '.', true);
+    module_dirs.push_back(base_dir + "/" + release[0] + "." + release[1]);
+
+    for (auto&& module_dir:module_dirs) {
+        Try_And_Load_Modules(module_dir);
+    }
+
+    for (auto&& module_dir:vendor_module_dirs) {
+        Try_And_Load_Modules(module_dir);
+    }
+
+    if (ven) {
+        LOGINFO("Checking mounted /vendor\n");
+        ven->Mount(true);
+    }
+
+    for (auto&& module_dir:vendor_module_dirs) {
+        Try_And_Load_Modules(module_dir);
+    }
+
+    if (ven)
+        ven->UnMount(false);
+
+	return true;
+}
+
+bool KernelModuleLoader::Try_And_Load_Modules(std::string module_dir) {
+        LOGINFO("Checking directory: %s\n", module_dir.c_str());
+        std::string dest_module_dir;
+        dest_module_dir = "/tmp" + module_dir;
+        TWFunc::Recursive_Mkdir(dest_module_dir);
+        Copy_Modules_To_Tmpfs(module_dir);
+        Write_Module_List(dest_module_dir);
+        Modprobe m({dest_module_dir}, "modules.load.twrp");
+        m.EnableVerbose(true);
+        m.LoadListedModules(false);
+        int modules_loaded = m.GetModuleCount();
+        LOGINFO("Modules Loaded: %d\n", modules_loaded);
+        return modules_loaded > 0 ? true : false;
+}
+
+bool KernelModuleLoader::Write_Module_List(std::string module_dir) {
+	DIR* d;
+	struct dirent* de;
+	std::vector<std::string> kernel_modules;
+	std::vector<std::string> kernel_modules_requested = TWFunc::split_string(EXPAND(TW_LOAD_VENDOR_MODULES), ' ', true);
+	d = opendir(module_dir.c_str());
+	if (d != nullptr) {
+		while ((de = readdir(d)) != nullptr) {
+			std::string kernel_module = de->d_name;
+			if (de->d_type == DT_REG) {
+				if (android::base::EndsWith(kernel_module, ".ko")) {
+					for (auto&& requested:kernel_modules_requested) {
+						if (kernel_module == requested) {
+							kernel_modules.push_back(kernel_module);
+                            continue;
+                        }
+					}
+					continue;
+				}
+			}
+		}
+        std::string module_file = module_dir + "/modules.load.twrp";
+		TWFunc::write_to_file(module_file, kernel_modules);
+        closedir(d);
+	}
+	return true;
+}
+
+bool KernelModuleLoader::Copy_Modules_To_Tmpfs(std::string module_dir) {
+    std::string ramdisk_dir = "/tmp" + module_dir;
+    DIR* d;
+	struct dirent* de;
+    d = opendir(module_dir.c_str());
+    if (d != nullptr) {
+        while ((de = readdir(d)) != nullptr) {
+            std::string kernel_module = de->d_name;
+            if (de->d_type == DT_REG) {
+                std::string src =  module_dir + "/" + de->d_name;
+                std::string dest = ramdisk_dir + "/" + de->d_name;
+                if (TWFunc::copy_file(src, dest, 0700, false) != 0) {
+                    return false;
+                }
+            }
+        }
+        closedir(d);
+    } else {
+        LOGINFO("Unable to open module directory: %s. Skipping\n", module_dir.c_str());
+        return false;
+    }
+    return true;
+}
\ No newline at end of file