1 /* 2 * Copyright (C) 2014 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include <stdlib.h> 18 #include <stdio.h> 19 #include <errno.h> 20 #include <pthread.h> 21 #include <sys/mount.h> 22 #include <sys/stat.h> 23 #include <unistd.h> 24 #include <fcntl.h> 25 26 #include "fuse_sideload.h" 27 28 struct file_data { 29 int fd; // the underlying sdcard file 30 31 uint64_t file_size; 32 uint32_t block_size; 33 }; 34 35 static int read_block_file(void* cookie, uint32_t block, uint8_t* buffer, uint32_t fetch_size) { 36 struct file_data* fd = (struct file_data*)cookie; 37 38 if (lseek(fd->fd, block * fd->block_size, SEEK_SET) < 0) { 39 printf("seek on sdcard failed: %s\n", strerror(errno)); 40 return -EIO; 41 } 42 43 while (fetch_size > 0) { 44 ssize_t r = read(fd->fd, buffer, fetch_size); 45 if (r < 0) { 46 if (r != -EINTR) { 47 printf("read on sdcard failed: %s\n", strerror(errno)); 48 return -EIO; 49 } 50 r = 0; 51 } 52 fetch_size -= r; 53 buffer += r; 54 } 55 56 return 0; 57 } 58 59 static void close_file(void* cookie) { 60 struct file_data* fd = (struct file_data*)cookie; 61 close(fd->fd); 62 } 63 64 struct token { 65 pthread_t th; 66 const char* path; 67 int result; 68 }; 69 70 static void* run_sdcard_fuse(void* cookie) { 71 struct token* t = (struct token*)cookie; 72 73 struct stat sb; 74 if (stat(t->path, &sb) < 0) { 75 fprintf(stderr, "failed to stat %s: %s\n", t->path, strerror(errno)); 76 t->result = -1; 77 return NULL; 78 } 79 80 struct file_data fd; 81 struct provider_vtab vtab; 82 83 fd.fd = open(t->path, O_RDONLY); 84 if (fd.fd < 0) { 85 fprintf(stderr, "failed to open %s: %s\n", t->path, strerror(errno)); 86 t->result = -1; 87 return NULL; 88 } 89 fd.file_size = sb.st_size; 90 fd.block_size = 65536; 91 92 vtab.read_block = read_block_file; 93 vtab.close = close_file; 94 95 t->result = run_fuse_sideload(&vtab, &fd, fd.file_size, fd.block_size); 96 return NULL; 97 } 98 99 // How long (in seconds) we wait for the fuse-provided package file to 100 // appear, before timing out. 101 #define SDCARD_INSTALL_TIMEOUT 10 102 103 void* start_sdcard_fuse(const char* path) { 104 struct token* t = malloc(sizeof(struct token)); 105 106 t->path = path; 107 pthread_create(&(t->th), NULL, run_sdcard_fuse, t); 108 109 struct stat st; 110 int i; 111 for (i = 0; i < SDCARD_INSTALL_TIMEOUT; ++i) { 112 if (stat(FUSE_SIDELOAD_HOST_PATHNAME, &st) != 0) { 113 if (errno == ENOENT && i < SDCARD_INSTALL_TIMEOUT-1) { 114 sleep(1); 115 continue; 116 } else { 117 return NULL; 118 } 119 } 120 } 121 122 // The installation process expects to find the sdcard unmounted. 123 // Unmount it with MNT_DETACH so that our open file continues to 124 // work but new references see it as unmounted. 125 umount2("/sdcard", MNT_DETACH); 126 127 return t; 128 } 129 130 void finish_sdcard_fuse(void* cookie) { 131 if (cookie == NULL) return; 132 struct token* t = (struct token*)cookie; 133 134 // Calling stat() on this magic filename signals the fuse 135 // filesystem to shut down. 136 struct stat st; 137 stat(FUSE_SIDELOAD_HOST_EXIT_PATHNAME, &st); 138 139 pthread_join(t->th, NULL); 140 free(t); 141 } 142
