1 files changed, 155 insertions, 0 deletions
diff --git a/adb/backup_service.c b/adb/backup_service.c
new file mode 100644
index 0000000..669ff86
--- /dev/null
+++ b/adb/backup_service.c
@@ -0,0 +1,155 @@
+/*
+ * 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"
+
+typedef struct {
+    pid_t pid;
+    int fd;
+} backup_harvest_params;
+
+// socketpair but do *not* mark as close_on_exec
+static int backup_socketpair(int sv[2]) {
+    int rc = unix_socketpair( AF_UNIX, SOCK_STREAM, 0, sv );
+    if (rc < 0)
+        return -1;
+
+    return 0;
+}
+
+// harvest the child process then close the read end of the socketpair
+static void* backup_child_waiter(void* args) {
+    int status;
+    backup_harvest_params* params = (backup_harvest_params*) args;
+
+    waitpid(params->pid, &status, 0);
+    adb_close(params->fd);
+    free(params);
+    return NULL;
+}
+
+/* returns the data socket passing the backup data here for forwarding */
+int backup_service(BackupOperation op, char* args) {
+    pid_t pid;
+    int s[2];
+    char* operation;
+    int socketnum;
+
+    // Command string and choice of stdin/stdout for the pipe depend on our invocation
+    if (op == BACKUP) {
+        operation = "backup";
+        socketnum = STDOUT_FILENO;
+    } else {
+        operation = "restore";
+        socketnum = STDIN_FILENO;
+    }
+
+    D("backup_service(%s, %s)\n", operation, args);
+
+    // set up the pipe from the subprocess to here
+    // parent will read s[0]; child will write s[1]
+    if (backup_socketpair(s)) {
+        D("can't create backup/restore socketpair\n");
+        fprintf(stderr, "unable to create backup/restore socketpair\n");
+        return -1;
+    }
+
+    D("Backup/restore socket pair: (send=%d, receive=%d)\n", s[1], s[0]);
+    close_on_exec(s[0]);    // only the side we hold on to
+
+    // spin off the child process to run the backup command
+    pid = fork();
+    if (pid < 0) {
+        // failure
+        D("can't fork for %s\n", operation);
+        fprintf(stderr, "unable to fork for %s\n", operation);
+        adb_close(s[0]);
+        adb_close(s[1]);
+        return -1;
+    }
+
+    // Great, we're off and running.
+    if (pid == 0) {
+        // child -- actually run the backup here
+        char* p;
+        int argc;
+        char portnum[16];
+        char** bu_args;
+
+        // fixed args:  [0] is 'bu', [1] is the port number, [2] is the 'operation' string
+        argc = 3;
+        for (p = (char*)args; p && *p; ) {
+            argc++;
+            while (*p && *p != ':') p++;
+            if (*p == ':') p++;
+        }
+
+        bu_args = (char**) alloca(argc*sizeof(char*) + 1);
+
+        // run through again to build the argv array
+        argc = 0;
+        bu_args[argc++] = "bu";
+        snprintf(portnum, sizeof(portnum), "%d", s[1]);
+        bu_args[argc++] = portnum;
+        bu_args[argc++] = operation;
+        for (p = (char*)args; p && *p; ) {
+            bu_args[argc++] = p;
+            while (*p && *p != ':') p++;
+            if (*p == ':') {
+                *p = 0;
+                p++;
+            }
+        }
+        bu_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]);
+
+        // off we go
+        execvp("/system/bin/bu", (char * const *)bu_args);
+        // oops error - close up shop and go home
+        fprintf(stderr, "Unable to exec 'bu', bailing\n");
+        exit(-1);
+    } else {
+        adb_thread_t t;
+        backup_harvest_params* params;
+
+        // parent, i.e. adbd -- close the sending half of the socket
+        D("fork() returned pid %d\n", pid);
+        adb_close(s[1]);
+
+        // spin a thread to harvest the child process
+        params = (backup_harvest_params*) malloc(sizeof(backup_harvest_params));
+        params->pid = pid;
+        params->fd = s[0];
+        if (adb_thread_create(&t, backup_child_waiter, params)) {
+            adb_close(s[0]);
+            free(params);
+            D("Unable to create child harvester\n");
+            return -1;
+        }
+    }
+
+    // we'll be reading from s[0] as the data is sent by the child process
+    return s[0];
+}