Move adb to C++.

I keep trying to clean things up and needing std::strings. Might as
well just do this now.

usb_linux_client.c is going to stay as C because GCC isn't smart
enough to deal with the designated initializers it uses (though for
some reason it is in C mode).

The Darwin files are staying as C because I don't have a way to test
that they build.

The Windows files are staying as C because while I can actually build
for them, it's slow and painful.

Change-Id: I75367d29205a9049d34460032b3bb36384f43941

1 files changed, 227 insertions, 0 deletions

diff --git a/adb/set_verity_enable_state_service.cpp b/adb/set_verity_enable_state_service.cpp
new file mode 100644
index 0000000..7fa8291
--- /dev/null
+++ b/adb/set_verity_enable_state_service.cpp
@@ -0,0 +1,227 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <fcntl.h>
+#include <inttypes.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <sys/stat.h>
+
+#define  TRACE_TAG  TRACE_ADB
+#include "adb.h"
+#include "cutils/properties.h"
+#include "ext4_sb.h"
+#include "fs_mgr.h"
+#include "sysdeps.h"
+
+#define FSTAB_PREFIX "/fstab."
+struct fstab *fstab;
+
+#ifdef ALLOW_ADBD_DISABLE_VERITY
+static const bool kAllowDisableVerity = true;
+#else
+static const bool kAllowDisableVerity = false;
+#endif
+
+__attribute__((__format__(printf, 2, 3))) __nonnull((2))
+static void write_console(int fd, const char* format, ...)
+{
+    char buffer[256];
+    va_list args;
+    va_start (args, format);
+    vsnprintf (buffer, sizeof(buffer), format, args);
+    va_end (args);
+
+    adb_write(fd, buffer, strnlen(buffer, sizeof(buffer)));
+}
+
+static int get_target_device_size(int fd, const char *blk_device,
+                                  uint64_t *device_size)
+{
+    int data_device;
+    struct ext4_super_block sb;
+    struct fs_info info;
+
+    info.len = 0;  /* Only len is set to 0 to ask the device for real size. */
+
+    data_device = adb_open(blk_device, O_RDONLY | O_CLOEXEC);
+    if (data_device < 0) {
+        write_console(fd, "Error opening block device (%s)\n", strerror(errno));
+        return -1;
+    }
+
+    if (lseek64(data_device, 1024, SEEK_SET) < 0) {
+        write_console(fd, "Error seeking to superblock\n");
+        adb_close(data_device);
+        return -1;
+    }
+
+    if (adb_read(data_device, &sb, sizeof(sb)) != sizeof(sb)) {
+        write_console(fd, "Error reading superblock\n");
+        adb_close(data_device);
+        return -1;
+    }
+
+    ext4_parse_sb(&sb, &info);
+    *device_size = info.len;
+
+    adb_close(data_device);
+    return 0;
+}
+
+/* Turn verity on/off */
+static int set_verity_enabled_state(int fd, const char *block_device,
+                                    const char* mount_point, bool enable)
+{
+    uint32_t magic_number;
+    const uint32_t new_magic = enable ? VERITY_METADATA_MAGIC_NUMBER
+                                      : VERITY_METADATA_MAGIC_DISABLE;
+    uint64_t device_length;
+    int device = -1;
+    int retval = -1;
+
+    if (make_block_device_writable(block_device)) {
+        write_console(fd, "Could not make block device %s writable (%s).\n",
+                      block_device, strerror(errno));
+        goto errout;
+    }
+
+    device = adb_open(block_device, O_RDWR | O_CLOEXEC);
+    if (device == -1) {
+        write_console(fd, "Could not open block device %s (%s).\n",
+                      block_device, strerror(errno));
+        write_console(fd, "Maybe run adb remount?\n");
+        goto errout;
+    }
+
+    // find the start of the verity metadata
+    if (get_target_device_size(fd, (char*)block_device, &device_length) < 0) {
+        write_console(fd, "Could not get target device size.\n");
+        goto errout;
+    }
+
+    if (lseek64(device, device_length, SEEK_SET) < 0) {
+        write_console(fd,
+                      "Could not seek to start of verity metadata block.\n");
+        goto errout;
+    }
+
+    // check the magic number
+    if (adb_read(device, &magic_number, sizeof(magic_number))
+             != sizeof(magic_number)) {
+        write_console(fd, "Couldn't read magic number!\n");
+        goto errout;
+    }
+
+    if (!enable && magic_number == VERITY_METADATA_MAGIC_DISABLE) {
+        write_console(fd, "Verity already disabled on %s\n", mount_point);
+        goto errout;
+    }
+
+    if (enable && magic_number == VERITY_METADATA_MAGIC_NUMBER) {
+        write_console(fd, "Verity already enabled on %s\n", mount_point);
+        goto errout;
+    }
+
+    if (magic_number != VERITY_METADATA_MAGIC_NUMBER
+            && magic_number != VERITY_METADATA_MAGIC_DISABLE) {
+        write_console(fd,
+                      "Couldn't find verity metadata at offset %" PRIu64 "!\n",
+                      device_length);
+        goto errout;
+    }
+
+    if (lseek64(device, device_length, SEEK_SET) < 0) {
+        write_console(fd,
+                      "Could not seek to start of verity metadata block.\n");
+        goto errout;
+    }
+
+    if (adb_write(device, &new_magic, sizeof(new_magic)) != sizeof(new_magic)) {
+        write_console(
+            fd, "Could not set verity %s flag on device %s with error %s\n",
+            enable ? "enabled" : "disabled",
+            block_device, strerror(errno));
+        goto errout;
+    }
+
+    write_console(fd, "Verity %s on %s\n",
+                  enable ? "enabled" : "disabled",
+                  mount_point);
+    retval = 0;
+errout:
+    if (device != -1)
+        adb_close(device);
+    return retval;
+}
+
+void set_verity_enabled_state_service(int fd, void* cookie)
+{
+    bool enable = (cookie != NULL);
+    if (kAllowDisableVerity) {
+        char fstab_filename[PROPERTY_VALUE_MAX + sizeof(FSTAB_PREFIX)];
+        char propbuf[PROPERTY_VALUE_MAX];
+        int i;
+        bool any_changed = false;
+
+        property_get("ro.secure", propbuf, "0");
+        if (strcmp(propbuf, "1")) {
+            write_console(fd, "verity not enabled - ENG build\n");
+            goto errout;
+        }
+
+        property_get("ro.debuggable", propbuf, "0");
+        if (strcmp(propbuf, "1")) {
+            write_console(
+                fd, "verity cannot be disabled/enabled - USER build\n");
+            goto errout;
+        }
+
+        property_get("ro.hardware", propbuf, "");
+        snprintf(fstab_filename, sizeof(fstab_filename), FSTAB_PREFIX"%s",
+                 propbuf);
+
+        fstab = fs_mgr_read_fstab(fstab_filename);
+        if (!fstab) {
+            write_console(fd, "Failed to open %s\nMaybe run adb root?\n",
+                          fstab_filename);
+            goto errout;
+        }
+
+        /* Loop through entries looking for ones that vold manages */
+        for (i = 0; i < fstab->num_entries; i++) {
+            if(fs_mgr_is_verified(&fstab->recs[i])) {
+                if (!set_verity_enabled_state(fd, fstab->recs[i].blk_device,
+                                              fstab->recs[i].mount_point,
+                                              enable)) {
+                    any_changed = true;
+                }
+           }
+        }
+
+        if (any_changed) {
+            write_console(
+                fd, "Now reboot your device for settings to take effect\n");
+        }
+    } else {
+        write_console(fd, "%s-verity only works for userdebug builds\n",
+                      enable ? "enable" : "disable");
+    }
+
+errout:
+    adb_close(fd);
+}