1 files changed, 180 insertions, 0 deletions
diff --git a/diskdev_cmds/edt_fstab/edt_fstab.c b/diskdev_cmds/edt_fstab/edt_fstab.c
new file mode 100644
index 0000000..42a53fe
--- /dev/null
+++ b/diskdev_cmds/edt_fstab/edt_fstab.c
@@ -0,0 +1,180 @@
+/*
+ * Copyright (c) 2018-2020 Apple Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+//  edt_fstab.c
+//
+//  Created on 12/11/2018.
+//
+
+#include <sys/types.h>
+
+#include "edt_fstab.h"
+
+#if (TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR)
+
+/* Some APFS specific goop */
+#include <APFS/APFS.h>
+#include <CoreFoundation/CoreFoundation.h>
+#include <IOKit/IOKitLib.h>
+#include <os/bsd.h>
+#include <sys/stat.h>
+#include <paths.h>
+
+char boot_container[EDTVolumePropertySize] = {};
+char data_volume[EDTVolumePropertySize] = {};
+
+static uint32_t edt_os_environment = EDT_OS_ENV_MAIN;
+
+const char *
+get_boot_container(uint32_t *os_envp)
+{
+	kern_return_t err;
+	CFMutableDictionaryRef fs_info = NULL;
+	CFStringRef container = NULL;
+	CFDataRef os_env = NULL;
+
+	// already got the boot container
+	if (strnlen(boot_container, sizeof(boot_container)) > 0) {
+		*os_envp = edt_os_environment;
+		return boot_container;
+	}
+
+	fs_info = IORegistryEntryFromPath(kIOMasterPortDefault, kEDTFilesystemEntry);
+	if (fs_info == IO_OBJECT_NULL) {
+		fprintf(stderr, "failed to get filesystem info\n");
+		return NULL;
+	}
+
+	// lookup the OS environment being booted, assumes main OS upon failure
+	os_env = IORegistryEntryCreateCFProperty(fs_info, kEDTOSEnvironment, kCFAllocatorDefault, 0);
+	if (os_env) {
+		CFDataGetBytes(os_env, CFRangeMake(0, CFDataGetLength(os_env)), (UInt8*)(&edt_os_environment));
+		CFRelease(os_env);
+	}
+	IOObjectRelease(fs_info);
+	*os_envp = edt_os_environment;
+
+	// lookup the boot container
+	err = APFSContainerGetBootDevice(&container);
+	if (!err) {
+		strcpy(boot_container, _PATH_DEV);
+		CFStringGetCString(container,
+						   boot_container + strlen(_PATH_DEV),
+						   EDTVolumePropertySize - strlen(_PATH_DEV),
+						   kCFStringEncodingUTF8);
+		CFRelease(container);
+		return boot_container;
+	} else {
+		// just a warning if not booting the main OS (rdar://48693021)
+		fprintf(stderr, "%sfailed to get boot device - %s\n",
+				(edt_os_environment == EDT_OS_ENV_MAIN) ? "" : "warning: ",
+				strerror(err_get_code(err)));
+		return NULL;
+	}
+}
+
+const char *
+get_data_volume(void)
+{
+	const char *container = NULL;
+	CFMutableArrayRef matches = NULL;
+	OSStatus status;
+
+	// already got the data volume
+	if (strnlen(data_volume, sizeof(data_volume)) > 0) {
+		return data_volume;
+	}
+
+	// get the boot container
+	if (strlen(boot_container) > 0) {
+		container = boot_container;
+	} else {
+		uint32_t os_env;
+		container = get_boot_container(&os_env);
+	}
+	if (!container) {
+		return NULL;
+	}
+
+	// lookup the data volume
+	status = APFSVolumeRoleFind(container, APFS_VOL_ROLE_DATA, &matches);
+	if (status) {
+		// just a warning if not booting the main OS
+		fprintf(stderr, "%sfailed to lookup data volume - %s\n",
+				(edt_os_environment == EDT_OS_ENV_MAIN) ? "" : "warning: ",
+				strerror(err_get_code(status)));
+		return NULL;
+	} else if (CFArrayGetCount(matches) > 1) {
+		fprintf(stderr, "found multiple data volumes\n");
+		CFRelease(matches);
+		return NULL;
+	} else {
+		CFStringGetCString(CFArrayGetValueAtIndex(matches, 0),
+						   data_volume,
+						   EDTVolumePropertySize,
+						   kCFStringEncodingUTF8);
+		CFRelease(matches);
+		return data_volume;
+	}
+}
+
+int
+get_boot_manifest_hash(char *boot_manifest_hash, size_t boot_manifest_hash_len)
+{
+	kern_return_t err = 0;
+	io_registry_entry_t chosen;
+	CFDataRef bm_hash = NULL;
+	size_t bm_hash_size;
+	uint8_t bm_hash_buf[EDTVolumePropertyMaxSize] = {};
+	const char *hexmap = "0123456789ABCDEF";
+
+	chosen = IORegistryEntryFromPath(kIOMasterPortDefault, kIODeviceTreePlane ":/chosen");
+	if (chosen == IO_OBJECT_NULL) {
+		fprintf(stderr, "failed to get chosen info\n");
+		return ENOENT;
+	}
+
+	bm_hash = IORegistryEntryCreateCFProperty(chosen, CFSTR("boot-manifest-hash"), kCFAllocatorDefault, 0);
+	if (!bm_hash) {
+		fprintf(stderr, "failed to get boot-manifest-hash\n");
+		IOObjectRelease(chosen);
+		return ENOENT;
+	} else {
+		bm_hash_size = CFDataGetLength(bm_hash);
+		CFDataGetBytes(bm_hash, CFRangeMake(0, bm_hash_size), bm_hash_buf);
+
+		if (boot_manifest_hash_len < (bm_hash_size * 2 + 1)) {
+			err = EINVAL;
+		} else {
+			// hexdump the hash into input buffer
+			for (size_t i = 0; i < (2 * bm_hash_size); i++)
+				*boot_manifest_hash++ = hexmap[(bm_hash_buf[i / 2] >> ((i % 2) ? 0 : 4)) & 0xf];
+			*boot_manifest_hash = '\0';
+		}
+		CFRelease(bm_hash);
+		IOObjectRelease(chosen);
+	}
+
+	return err;
+}
+#endif /* (TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR) */