Loop.cpp revision 8b8f71b1d760411279f3b07a5c97709f052c689e
1a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat/* 2a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat * Copyright (C) 2008 The Android Open Source Project 3a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat * 4a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat * Licensed under the Apache License, Version 2.0 (the "License"); 5a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat * you may not use this file except in compliance with the License. 6a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat * You may obtain a copy of the License at 7a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat * 8a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat * http://www.apache.org/licenses/LICENSE-2.0 9a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat * 10a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat * Unless required by applicable law or agreed to in writing, software 11a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat * distributed under the License is distributed on an "AS IS" BASIS, 12a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat * See the License for the specific language governing permissions and 14a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat * limitations under the License. 15a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat */ 16a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 17a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat#include <stdio.h> 18a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat#include <fcntl.h> 19a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat#include <unistd.h> 20a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat#include <errno.h> 21a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat#include <string.h> 22a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 238da6bcb006f4e4257cdd685e35e910a6334f6ceaSan Mehat#include <sys/types.h> 248da6bcb006f4e4257cdd685e35e910a6334f6ceaSan Mehat#include <sys/stat.h> 258da6bcb006f4e4257cdd685e35e910a6334f6ceaSan Mehat 26a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat#define LOG_TAG "Vold" 27a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 28a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat#include <cutils/log.h> 29a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 30a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat#include "Loop.h" 31a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 32a19b250bd273455933ca3502cf2c2e0a803aff77San Mehatint Loop::lookupActive(const char *loopFile, char *buffer, size_t len) { 33a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat int i; 34a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat int fd; 35a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat char filename[256]; 36a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 37a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat memset(buffer, 0, len); 38a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 39a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat for (i = 0; i < LOOP_MAX; i++) { 40a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat struct loop_info li; 41a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat int rc; 42a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 43a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat sprintf(filename, "/dev/block/loop%d", i); 44a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 45a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat if ((fd = open(filename, O_RDWR)) < 0) { 46b78a32c1d5eeb243bdac0eaf18effb1897f1ee67San Mehat if (errno != ENOENT) { 47b78a32c1d5eeb243bdac0eaf18effb1897f1ee67San Mehat LOGE("Unable to open %s (%s)", filename, strerror(errno)); 48b78a32c1d5eeb243bdac0eaf18effb1897f1ee67San Mehat } 49a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat return -1; 50a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat } 51a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 52a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat rc = ioctl(fd, LOOP_GET_STATUS, &li); 53a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat close(fd); 54a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat if (rc < 0 && errno == ENXIO) { 55a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat continue; 56a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat break; 57a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat } 58a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 59a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat if (rc < 0) { 60a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat LOGE("Unable to get loop status for %s (%s)", filename, 61a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat strerror(errno)); 62a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat return -1; 63a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat } 64a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat if (!strncmp(li.lo_name, loopFile, LO_NAME_SIZE)) { 65a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat break; 66a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat } 67a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat } 68a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 69a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat if (i == LOOP_MAX) { 70a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat errno = ENOENT; 71a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat return -1; 72a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat } 73a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat strncpy(buffer, filename, len -1); 74a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat return 0; 75a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat} 76a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 778da6bcb006f4e4257cdd685e35e910a6334f6ceaSan Mehatint Loop::create(const char *loopFile, char *loopDeviceBuffer, size_t len) { 78a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat int i; 79a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat int fd; 80a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat char filename[256]; 81a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 82a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat for (i = 0; i < LOOP_MAX; i++) { 83a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat struct loop_info li; 84a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat int rc; 85a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 86a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat sprintf(filename, "/dev/block/loop%d", i); 87a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 888da6bcb006f4e4257cdd685e35e910a6334f6ceaSan Mehat /* 898da6bcb006f4e4257cdd685e35e910a6334f6ceaSan Mehat * The kernel starts us off with 8 loop nodes, but more 908da6bcb006f4e4257cdd685e35e910a6334f6ceaSan Mehat * are created on-demand if needed. 918da6bcb006f4e4257cdd685e35e910a6334f6ceaSan Mehat */ 928da6bcb006f4e4257cdd685e35e910a6334f6ceaSan Mehat mode_t mode = 0660 | S_IFBLK; 93b78a32c1d5eeb243bdac0eaf18effb1897f1ee67San Mehat unsigned int dev = (0xff & i) | ((i << 12) & 0xfff00000) | (7 << 8); 948da6bcb006f4e4257cdd685e35e910a6334f6ceaSan Mehat if (mknod(filename, mode, dev) < 0) { 958da6bcb006f4e4257cdd685e35e910a6334f6ceaSan Mehat if (errno != EEXIST) { 968da6bcb006f4e4257cdd685e35e910a6334f6ceaSan Mehat LOGE("Error creating loop device node (%s)", strerror(errno)); 978da6bcb006f4e4257cdd685e35e910a6334f6ceaSan Mehat return -1; 988da6bcb006f4e4257cdd685e35e910a6334f6ceaSan Mehat } 998da6bcb006f4e4257cdd685e35e910a6334f6ceaSan Mehat } 1008da6bcb006f4e4257cdd685e35e910a6334f6ceaSan Mehat 101a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat if ((fd = open(filename, O_RDWR)) < 0) { 102a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat LOGE("Unable to open %s (%s)", filename, strerror(errno)); 103a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat return -1; 104a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat } 105a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 106a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat rc = ioctl(fd, LOOP_GET_STATUS, &li); 107a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat if (rc < 0 && errno == ENXIO) 108a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat break; 109a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 1108da6bcb006f4e4257cdd685e35e910a6334f6ceaSan Mehat close(fd); 1118da6bcb006f4e4257cdd685e35e910a6334f6ceaSan Mehat 112a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat if (rc < 0) { 113a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat LOGE("Unable to get loop status for %s (%s)", filename, 114a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat strerror(errno)); 115a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat return -1; 116a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat } 117a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat } 118a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 119a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat if (i == LOOP_MAX) { 120a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat LOGE("Exhausted all loop devices"); 121a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat errno = ENOSPC; 122a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat return -1; 123a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat } 124a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 1258da6bcb006f4e4257cdd685e35e910a6334f6ceaSan Mehat strncpy(loopDeviceBuffer, filename, len -1); 126a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 1278da6bcb006f4e4257cdd685e35e910a6334f6ceaSan Mehat int file_fd; 128a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 129a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat if ((file_fd = open(loopFile, O_RDWR)) < 0) { 130a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat LOGE("Unable to open %s (%s)", loopFile, strerror(errno)); 131a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat close(fd); 132a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat return -1; 133a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat } 134a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 135a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat if (ioctl(fd, LOOP_SET_FD, file_fd) < 0) { 136a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat LOGE("Error setting up loopback interface (%s)", strerror(errno)); 137a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat close(file_fd); 138a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat close(fd); 139a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat return -1; 140a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat } 141a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 142a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat struct loop_info li; 143a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 144a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat memset(&li, 0, sizeof(li)); 145a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat strncpy(li.lo_name, loopFile, LO_NAME_SIZE); 146a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 147a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat if (ioctl(fd, LOOP_SET_STATUS, &li) < 0) { 148a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat LOGE("Error setting loopback status (%s)", strerror(errno)); 149a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat close(file_fd); 150a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat close(fd); 151a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat return -1; 152a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat } 153a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 154a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat close(fd); 155a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat close(file_fd); 156a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 157a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat return 0; 158a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat} 159a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 160a19b250bd273455933ca3502cf2c2e0a803aff77San Mehatint Loop::destroyByDevice(const char *loopDevice) { 161a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat int device_fd; 162a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 163a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat device_fd = open(loopDevice, O_RDONLY); 164a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat if (device_fd < 0) { 165a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat LOGE("Failed to open loop (%d)", errno); 166a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat return -1; 167a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat } 168a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 169a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat if (ioctl(device_fd, LOOP_CLR_FD, 0) < 0) { 170a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat LOGE("Failed to destroy loop (%d)", errno); 171a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat close(device_fd); 172a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat return -1; 173a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat } 174a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 175a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat close(device_fd); 176a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat return 0; 177a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat} 178a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 179a19b250bd273455933ca3502cf2c2e0a803aff77San Mehatint Loop::destroyByFile(const char *loopFile) { 180a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat errno = ENOSYS; 181a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat return -1; 182a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat} 183a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 1848b8f71b1d760411279f3b07a5c97709f052c689eSan Mehatint Loop::createImageFile(const char *file, unsigned int numSectors) { 185a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat int fd; 186a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 1878b8f71b1d760411279f3b07a5c97709f052c689eSan Mehat LOGD("Creating ASEC image file %s (%u sectors)", file, numSectors); 188a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 189a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat if ((fd = creat(file, 0600)) < 0) { 190a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat LOGE("Error creating imagefile (%s)", strerror(errno)); 191a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat return -1; 192a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat } 193a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat 1948b8f71b1d760411279f3b07a5c97709f052c689eSan Mehat if (ftruncate(fd, numSectors * 512) < 0) { 195a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat LOGE("Error truncating imagefile (%s)", strerror(errno)); 196a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat close(fd); 197a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat return -1; 198a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat } 199a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat close(fd); 200a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat return 0; 201a19b250bd273455933ca3502cf2c2e0a803aff77San Mehat} 202