1 files changed, 140 insertions, 0 deletions

diff --git a/fuse_sdcard_provider.cpp b/fuse_sdcard_provider.cpp
new file mode 100644
index 000000000..eb6454f1d
--- /dev/null
+++ b/fuse_sdcard_provider.cpp
@@ -0,0 +1,140 @@
+/*
+ * Copyright (C) 2014 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 <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <pthread.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#include "fuse_sideload.h"
+
+struct file_data {
+    int fd;  // the underlying sdcard file
+
+    uint64_t file_size;
+    uint32_t block_size;
+};
+
+static int read_block_file(void* cookie, uint32_t block, uint8_t* buffer, uint32_t fetch_size) {
+    file_data* fd = reinterpret_cast<file_data*>(cookie);
+
+    off64_t offset = ((off64_t) block) * fd->block_size;
+    if (TEMP_FAILURE_RETRY(lseek64(fd->fd, offset, SEEK_SET)) == -1) {
+        fprintf(stderr, "seek on sdcard failed: %s\n", strerror(errno));
+        return -EIO;
+    }
+
+    while (fetch_size > 0) {
+        ssize_t r = TEMP_FAILURE_RETRY(read(fd->fd, buffer, fetch_size));
+        if (r == -1) {
+            fprintf(stderr, "read on sdcard failed: %s\n", strerror(errno));
+            return -EIO;
+        }
+        fetch_size -= r;
+        buffer += r;
+    }
+
+    return 0;
+}
+
+static void close_file(void* cookie) {
+    file_data* fd = reinterpret_cast<file_data*>(cookie);
+    close(fd->fd);
+}
+
+struct token {
+    pthread_t th;
+    const char* path;
+    int result;
+};
+
+static void* run_sdcard_fuse(void* cookie) {
+    token* t = reinterpret_cast<token*>(cookie);
+
+    struct stat sb;
+    if (stat(t->path, &sb) < 0) {
+        fprintf(stderr, "failed to stat %s: %s\n", t->path, strerror(errno));
+        t->result = -1;
+        return NULL;
+    }
+
+    struct file_data fd;
+    struct provider_vtab vtab;
+
+    fd.fd = open(t->path, O_RDONLY);
+    if (fd.fd < 0) {
+        fprintf(stderr, "failed to open %s: %s\n", t->path, strerror(errno));
+        t->result = -1;
+        return NULL;
+    }
+    fd.file_size = sb.st_size;
+    fd.block_size = 65536;
+
+    vtab.read_block = read_block_file;
+    vtab.close = close_file;
+
+    t->result = run_fuse_sideload(&vtab, &fd, fd.file_size, fd.block_size);
+    return NULL;
+}
+
+// How long (in seconds) we wait for the fuse-provided package file to
+// appear, before timing out.
+#define SDCARD_INSTALL_TIMEOUT 10
+
+void* start_sdcard_fuse(const char* path) {
+    token* t = new token;
+
+    t->path = path;
+    pthread_create(&(t->th), NULL, run_sdcard_fuse, t);
+
+    struct stat st;
+    int i;
+    for (i = 0; i < SDCARD_INSTALL_TIMEOUT; ++i) {
+        if (stat(FUSE_SIDELOAD_HOST_PATHNAME, &st) != 0) {
+            if (errno == ENOENT && i < SDCARD_INSTALL_TIMEOUT-1) {
+                sleep(1);
+                continue;
+            } else {
+                return NULL;
+            }
+        }
+    }
+
+    // The installation process expects to find the sdcard unmounted.
+    // Unmount it with MNT_DETACH so that our open file continues to
+    // work but new references see it as unmounted.
+    umount2("/sdcard", MNT_DETACH);
+
+    return t;
+}
+
+void finish_sdcard_fuse(void* cookie) {
+    if (cookie == NULL) return;
+    token* t = reinterpret_cast<token*>(cookie);
+
+    // Calling stat() on this magic filename signals the fuse
+    // filesystem to shut down.
+    struct stat st;
+    stat(FUSE_SIDELOAD_HOST_EXIT_PATHNAME, &st);
+
+    pthread_join(t->th, NULL);
+    delete t;
+}