From 9270a20a801403c9f60d6a701b39eae70d380403 Mon Sep 17 00:00:00 2001
From: Doug Zongker <dougz@android.com>
Date: Mon, 9 Jan 2012 15:16:13 -0800
Subject: support "sideload over ADB" mode

Rather than depending on the existence of some place to store a file
that is accessible to users on an an unbootable device (eg, a physical
sdcard, external USB drive, etc.), add support for sideloading
packages sent to the device with adb.

This change adds a "minimal adbd" which supports nothing but receiving
a package over adb (with the "adb sideload" command) and storing it to
a fixed filename in the /tmp ramdisk, from where it can be verified
and sideloaded in the usual way.  This should be leave available even
on locked user-build devices.

The user can select "apply package from ADB" from the recovery menu,
which starts minimal-adb mode (shutting down any real adbd that may be
running).  Once minimal-adb has received a package it exits
(restarting real adbd if appropriate) and then verification and
installation of the received package proceeds.

Change-Id: I6fe13161ca064a98d06fa32104e1f432826582f5
---
 minadbd/utils.c | 106 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 106 insertions(+)
 create mode 100644 minadbd/utils.c

(limited to 'minadbd/utils.c')

diff --git a/minadbd/utils.c b/minadbd/utils.c
new file mode 100644
index 000000000..91518bab6
--- /dev/null
+++ b/minadbd/utils.c
@@ -0,0 +1,106 @@
+/*
+ * Copyright (C) 2008 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 "utils.h"
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+
+char*
+buff_addc (char*  buff, char*  buffEnd, int  c)
+{
+    int  avail = buffEnd - buff;
+
+    if (avail <= 0)  /* already in overflow mode */
+        return buff;
+
+    if (avail == 1) {  /* overflowing, the last byte is reserved for zero */
+        buff[0] = 0;
+        return buff + 1;
+    }
+
+    buff[0] = (char) c;  /* add char and terminating zero */
+    buff[1] = 0;
+    return buff + 1;
+}
+
+char*
+buff_adds (char*  buff, char*  buffEnd, const char*  s)
+{
+    int  slen = strlen(s);
+
+    return buff_addb(buff, buffEnd, s, slen);
+}
+
+char*
+buff_addb (char*  buff, char*  buffEnd, const void*  data, int  len)
+{
+    int  avail = (buffEnd - buff);
+
+    if (avail <= 0 || len <= 0)  /* already overflowing */
+        return buff;
+
+    if (len > avail)
+        len = avail;
+
+    memcpy(buff, data, len);
+
+    buff += len;
+
+    /* ensure there is a terminating zero */
+    if (buff >= buffEnd) {  /* overflow */
+        buff[-1] = 0;
+    } else
+        buff[0] = 0;
+
+    return buff;
+}
+
+char*
+buff_add  (char*  buff, char*  buffEnd, const char*  format, ... )
+{
+    int      avail;
+
+    avail = (buffEnd - buff);
+
+    if (avail > 0) {
+        va_list  args;
+        int      nn;
+
+        va_start(args, format);
+        nn = vsnprintf( buff, avail, format, args);
+        va_end(args);
+
+        if (nn < 0) {
+            /* some C libraries return -1 in case of overflow,
+             * but they will also do that if the format spec is
+             * invalid. We assume ADB is not buggy enough to
+             * trigger that last case. */
+            nn = avail;
+        }
+        else if (nn > avail) {
+            nn = avail;
+        }
+
+        buff += nn;
+
+        /* ensure that there is a terminating zero */
+        if (buff >= buffEnd)
+            buff[-1] = 0;
+        else
+            buff[0] = 0;
+    }
+    return buff;
+}
-- 
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