commit 0ea946c007cf76a96d867ba3e96505f72639960e
author Chris Fries <cfries@google.com> Wed Apr 12 10:25:57 2017 -0500
committer Chris Fries <cfries@google.com> Mon Apr 17 09:22:49 2017 -0500
tree a67c7252fdc8a3c16b588ee6fc1e1155b00fb69b
parent 6a99971096a9c5a6752f494db1d9b57d4ab77af2

fastboot: Support larger transfers during flash

Adding methods to queue and download flashable images by fd instead of
by pointer, so that we can deal with sending large (up to 4GB) files
on windows and linux.  This gets past limitations on linux to read
more than 2GB from a file at a time, as well as memory limitations
on win32, in order to download up to 4GB in a single transfer.

Test: fastboot -w
Test: "flash-all" from nexus factory images site (incl. fastboot -w update)
Test: fastboot flash with large and small image, large and small max-download-size
Test: Sanity check flashing on win32, darwin, linux.
Test: Sanity check 3GB image download (with 3GB max-download-size)
      on win32, darwin, linux.

Bug: 36810152
Change-Id: I528d739d344eb080d59d721dadf3b3b34d4b375e

fastboot/fastboot.cpp

diff --git a/fastboot/fastboot.cpp b/fastboot/fastboot.cpp
index cb8e5c0..3b524ac 100644
--- a/fastboot/fastboot.cpp
+++ b/fastboot/fastboot.cpp
@@ -55,6 +55,7 @@
 #include <android-base/parsenetaddress.h>
 #include <android-base/stringprintf.h>
 #include <android-base/strings.h>
+#include <android-base/unique_fd.h>
 #include <sparse/sparse.h>
 #include <ziparchive/zip_archive.h>
 
@@ -67,6 +68,8 @@
 #include "udp.h"
 #include "usb.h"
 
+using android::base::unique_fd;
+
 #ifndef O_BINARY
 #define O_BINARY 0
 #endif
@@ -95,7 +98,7 @@
 static const std::string convert_fbe_marker_filename("convert_fbe");
 
 enum fb_buffer_type {
-    FB_BUFFER,
+    FB_BUFFER_FD,
     FB_BUFFER_SPARSE,
 };
 
@@ -103,6 +106,7 @@
     enum fb_buffer_type type;
     void* data;
     int64_t sz;
+    int fd;
 };
 
 static struct {
@@ -826,10 +830,9 @@
         buf->type = FB_BUFFER_SPARSE;
         buf->data = s;
     } else {
-        void* data = load_fd(fd, &sz);
-        if (data == nullptr) return -1;
-        buf->type = FB_BUFFER;
-        buf->data = data;
+        buf->type = FB_BUFFER_FD;
+        buf->data = nullptr;
+        buf->fd = fd;
         buf->sz = sz;
     }
 
@@ -837,11 +840,22 @@
 }
 
 static bool load_buf(Transport* transport, const char* fname, struct fastboot_buffer* buf) {
-    int fd = open(fname, O_RDONLY | O_BINARY);
+    unique_fd fd(TEMP_FAILURE_RETRY(open(fname, O_RDONLY | O_BINARY)));
+
     if (fd == -1) {
         return false;
     }
-    return load_buf_fd(transport, fd, buf);
+
+    struct stat s;
+    if (fstat(fd, &s)) {
+        return false;
+    }
+    if (!S_ISREG(s.st_mode)) {
+        errno = S_ISDIR(s.st_mode) ? EISDIR : EINVAL;
+        return false;
+    }
+
+    return load_buf_fd(transport, fd.release(), buf);
 }
 
 static void flash_buf(const char *pname, struct fastboot_buffer *buf)
@@ -864,9 +878,8 @@
             }
             break;
         }
-
-        case FB_BUFFER:
-            fb_queue_flash(pname, buf->data, buf->sz);
+        case FB_BUFFER_FD:
+            fb_queue_flash_fd(pname, buf->fd, buf->sz);
             break;
         default:
             die("unknown buffer type: %d", buf->type);