do sdcard sideloading through the fuse filesystem

Make a fuse filesystem that sits on top of the selected package file
on the sdcard, so we can verify that the file contents don't change
while being read and avoid copying the file to /tmp (that is, RAM)
before verifying and installing it.

Change-Id: Ifd982aa68bfe469eda5f839042648654bf7386a1

1 files changed, 9 insertions, 101 deletions

diff --git a/recovery.cpp b/recovery.cpp
index 1c7c0d6..d2d85e7 100644
--- a/recovery.cpp
+++ b/recovery.cpp
@@ -44,6 +44,8 @@
 #include "adb_install.h"
 extern "C" {
 #include "minadbd/adb.h"
+#include "fuse_sideload.h"
+#include "fuse_sdcard_provider.h"
 }
 
 struct selabel_handle *sehandle;
@@ -73,7 +75,6 @@ static const char *CACHE_ROOT = "/cache";
 static const char *SDCARD_ROOT = "/sdcard";
 static const char *TEMPORARY_LOG_FILE = "/tmp/recovery.log";
 static const char *TEMPORARY_INSTALL_FILE = "/tmp/last_install";
-static const char *SIDELOAD_TEMP_DIR = "/tmp/sideload";
 
 RecoveryUI* ui = NULL;
 char* locale = NULL;
@@ -439,96 +440,6 @@ erase_volume(const char *volume) {
     return result;
 }
 
-static char*
-copy_sideloaded_package(const char* original_path) {
-  if (ensure_path_mounted(original_path) != 0) {
-    LOGE("Can't mount %s\n", original_path);
-    return NULL;
-  }
-
-  if (ensure_path_mounted(SIDELOAD_TEMP_DIR) != 0) {
-    LOGE("Can't mount %s\n", SIDELOAD_TEMP_DIR);
-    return NULL;
-  }
-
-  if (mkdir(SIDELOAD_TEMP_DIR, 0700) != 0) {
-    if (errno != EEXIST) {
-      LOGE("Can't mkdir %s (%s)\n", SIDELOAD_TEMP_DIR, strerror(errno));
-      return NULL;
-    }
-  }
-
-  // verify that SIDELOAD_TEMP_DIR is exactly what we expect: a
-  // directory, owned by root, readable and writable only by root.
-  struct stat st;
-  if (stat(SIDELOAD_TEMP_DIR, &st) != 0) {
-    LOGE("failed to stat %s (%s)\n", SIDELOAD_TEMP_DIR, strerror(errno));
-    return NULL;
-  }
-  if (!S_ISDIR(st.st_mode)) {
-    LOGE("%s isn't a directory\n", SIDELOAD_TEMP_DIR);
-    return NULL;
-  }
-  if ((st.st_mode & 0777) != 0700) {
-    LOGE("%s has perms %o\n", SIDELOAD_TEMP_DIR, st.st_mode);
-    return NULL;
-  }
-  if (st.st_uid != 0) {
-    LOGE("%s owned by %lu; not root\n", SIDELOAD_TEMP_DIR, st.st_uid);
-    return NULL;
-  }
-
-  char copy_path[PATH_MAX];
-  strcpy(copy_path, SIDELOAD_TEMP_DIR);
-  strcat(copy_path, "/package.zip");
-
-  char* buffer = (char*)malloc(BUFSIZ);
-  if (buffer == NULL) {
-    LOGE("Failed to allocate buffer\n");
-    return NULL;
-  }
-
-  size_t read;
-  FILE* fin = fopen(original_path, "rb");
-  if (fin == NULL) {
-    LOGE("Failed to open %s (%s)\n", original_path, strerror(errno));
-    return NULL;
-  }
-  FILE* fout = fopen(copy_path, "wb");
-  if (fout == NULL) {
-    LOGE("Failed to open %s (%s)\n", copy_path, strerror(errno));
-    return NULL;
-  }
-
-  while ((read = fread(buffer, 1, BUFSIZ, fin)) > 0) {
-    if (fwrite(buffer, 1, read, fout) != read) {
-      LOGE("Short write of %s (%s)\n", copy_path, strerror(errno));
-      return NULL;
-    }
-  }
-
-  free(buffer);
-
-  if (fclose(fout) != 0) {
-    LOGE("Failed to close %s (%s)\n", copy_path, strerror(errno));
-    return NULL;
-  }
-
-  if (fclose(fin) != 0) {
-    LOGE("Failed to close %s (%s)\n", original_path, strerror(errno));
-    return NULL;
-  }
-
-  // "adb push" is happy to overwrite read-only files when it's
-  // running as root, but we'll try anyway.
-  if (chmod(copy_path, 0400) != 0) {
-    LOGE("Failed to chmod %s (%s)\n", copy_path, strerror(errno));
-    return NULL;
-  }
-
-  return strdup(copy_path);
-}
-
 static const char**
 prepend_title(const char* const* headers) {
     // count the number of lines in our title, plus the
@@ -812,17 +723,13 @@ prompt_and_wait(Device* device, int status) {
 
                 ui->Print("\n-- Install %s ...\n", path);
                 set_sdcard_update_bootloader_message();
-                char* copy = copy_sideloaded_package(path);
-                free(path);
-                ensure_path_unmounted(SDCARD_ROOT);
+                void* token = start_sdcard_fuse(path);
 
-                int status;
-                if (copy) {
-                    status = install_package(copy, &wipe_cache, TEMPORARY_INSTALL_FILE, true);
-                    free(copy);
-                } else {
-                    status = INSTALL_ERROR;
-                }
+                int status = install_package(FUSE_SIDELOAD_HOST_PATHNAME, &wipe_cache,
+                                             TEMPORARY_INSTALL_FILE, false);
+
+                finish_sdcard_fuse(token);
+                ensure_path_unmounted(SDCARD_ROOT);
 
                 if (status == INSTALL_SUCCESS && wipe_cache) {
                     ui->Print("\n-- Wiping cache (at package request)...\n");
@@ -832,6 +739,7 @@ prompt_and_wait(Device* device, int status) {
                         ui->Print("Cache wipe complete.\n");
                     }
                 }
+
                 if (status >= 0) {
                     if (status != INSTALL_SUCCESS) {
                         ui->SetBackground(RecoveryUI::ERROR);