Add 'adb backup' for pulling a full backup tarfile to the host

The direct command interfaces with the 'bu' binary in /system/bin
on the device.

Change-Id: I4cd69eedfe5144c47277573c5626c6ad8755d70b

1 files changed, 95 insertions, 0 deletions

diff --git a/adb/backup_service.c b/adb/backup_service.c
new file mode 100644
index 0000000..f5dc0b2
--- /dev/null
+++ b/adb/backup_service.c
@@ -0,0 +1,95 @@
+/*
+ * Copyright (C) 2011 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 <unistd.h>
+#include <stdio.h>
+
+#include "sysdeps.h"
+
+#define TRACE_TAG  TRACE_ADB
+#include "adb.h"
+
+/* returns the data socket passing the backup data here for forwarding */
+int backup_service(char* args) {
+    pid_t pid;
+    int s[2];
+
+    D("backup_service(%s)\n", args);
+
+    // set up the pipe from the subprocess to here
+    // parent will read s[0]; child will write s[1]
+    if (adb_socketpair(s)) {
+        D("can't create backup socketpair\n");
+        fprintf(stderr, "unable to create backup socketpair\n");
+        return -1;
+    }
+
+    // spin off the child process to run the backup command
+    pid = fork();
+    if (pid < 0) {
+        // failure
+        D("can't fork for backup\n");
+        fprintf(stderr, "unable to fork for backup\n");
+        adb_close(s[0]);
+        adb_close(s[1]);
+        return -1;
+    }
+
+    // Great, we're off and running.
+    if (pid == 0) {
+        char* p;
+        int argc;
+        char** backup_args;
+
+        // child -- actually run the backup here
+        argc = 1; // room for the basic 'bu' argv[0]
+        for (p = (char*)args; p && *p; ) {
+            argc++;
+            while (*p && *p != ':') p++;
+            if (*p == ':') p++;
+        }
+
+        backup_args = (char**) alloca(argc*sizeof(char*) + 1);
+        backup_args[0] = "bu";
+        argc = 1;   // run through again to build the argv array
+        for (p = (char*)args; *p; ) {
+            backup_args[argc++] = p;
+            while (*p && *p != ':') p++;
+            if (*p == ':') {
+                *p = 0;
+                p++;
+            }
+        }
+        backup_args[argc] = NULL;
+
+        // Close the half of the socket that we don't care about, route 'bu's console
+        // to the output socket, and off we go
+        adb_close(s[0]);
+        dup2(s[1], STDOUT_FILENO);
+
+        // off we go
+        execvp("/system/bin/bu", (char * const *)backup_args);
+        // oops error - close up shop and go home
+        fprintf(stderr, "Unable to exec 'bu', bailing\n");
+        exit(-1);
+    } else {
+        // parent, i.e. adbd -- close the sending half of the socket
+        adb_close(s[1]);
+    }
+
+    // we'll be reading from s[0] as the data is sent by the child process
+    return s[0];
+}