Dan Albert | aac6b7c | 2015-03-16 10:08:46 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2015 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 "base/file.h" |
| 18 | |
| 19 | #include <errno.h> |
| 20 | #include <fcntl.h> |
| 21 | #include <sys/stat.h> |
| 22 | #include <sys/types.h> |
| 23 | |
| 24 | #include <string> |
| 25 | |
Dan Albert | d984411 | 2015-03-16 10:09:07 -0700 | [diff] [blame] | 26 | #include "base/macros.h" // For TEMP_FAILURE_RETRY on Darwin. |
Dan Albert | aac6b7c | 2015-03-16 10:08:46 -0700 | [diff] [blame] | 27 | #define LOG_TAG "base.file" |
| 28 | #include "cutils/log.h" |
Dan Albert | 5f77022 | 2015-03-26 23:33:28 -0700 | [diff] [blame] | 29 | #include "utils/Compat.h" |
Dan Albert | aac6b7c | 2015-03-16 10:08:46 -0700 | [diff] [blame] | 30 | |
Elliott Hughes | d5f8ae6 | 2015-09-01 13:35:44 -0700 | [diff] [blame] | 31 | #if !defined(_WIN32) |
| 32 | #define O_BINARY 0 |
| 33 | #endif |
| 34 | |
Dan Albert | aac6b7c | 2015-03-16 10:08:46 -0700 | [diff] [blame] | 35 | namespace android { |
| 36 | namespace base { |
| 37 | |
| 38 | bool ReadFdToString(int fd, std::string* content) { |
| 39 | content->clear(); |
| 40 | |
| 41 | char buf[BUFSIZ]; |
| 42 | ssize_t n; |
| 43 | while ((n = TEMP_FAILURE_RETRY(read(fd, &buf[0], sizeof(buf)))) > 0) { |
| 44 | content->append(buf, n); |
| 45 | } |
| 46 | return (n == 0) ? true : false; |
| 47 | } |
| 48 | |
| 49 | bool ReadFileToString(const std::string& path, std::string* content) { |
| 50 | content->clear(); |
| 51 | |
Elliott Hughes | d5f8ae6 | 2015-09-01 13:35:44 -0700 | [diff] [blame] | 52 | int fd = TEMP_FAILURE_RETRY(open(path.c_str(), O_RDONLY | O_CLOEXEC | O_NOFOLLOW | O_BINARY)); |
Dan Albert | aac6b7c | 2015-03-16 10:08:46 -0700 | [diff] [blame] | 53 | if (fd == -1) { |
| 54 | return false; |
| 55 | } |
| 56 | bool result = ReadFdToString(fd, content); |
Nick Kralevich | 8292130 | 2015-05-20 08:59:21 -0700 | [diff] [blame] | 57 | close(fd); |
Dan Albert | aac6b7c | 2015-03-16 10:08:46 -0700 | [diff] [blame] | 58 | return result; |
| 59 | } |
| 60 | |
| 61 | bool WriteStringToFd(const std::string& content, int fd) { |
| 62 | const char* p = content.data(); |
| 63 | size_t left = content.size(); |
| 64 | while (left > 0) { |
| 65 | ssize_t n = TEMP_FAILURE_RETRY(write(fd, p, left)); |
| 66 | if (n == -1) { |
| 67 | return false; |
| 68 | } |
| 69 | p += n; |
| 70 | left -= n; |
| 71 | } |
| 72 | return true; |
| 73 | } |
| 74 | |
| 75 | static bool CleanUpAfterFailedWrite(const std::string& path) { |
| 76 | // Something went wrong. Let's not leave a corrupt file lying around. |
| 77 | int saved_errno = errno; |
| 78 | unlink(path.c_str()); |
| 79 | errno = saved_errno; |
| 80 | return false; |
| 81 | } |
| 82 | |
| 83 | #if !defined(_WIN32) |
| 84 | bool WriteStringToFile(const std::string& content, const std::string& path, |
| 85 | mode_t mode, uid_t owner, gid_t group) { |
Elliott Hughes | d5f8ae6 | 2015-09-01 13:35:44 -0700 | [diff] [blame] | 86 | int flags = O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC | O_NOFOLLOW | O_BINARY; |
| 87 | int fd = TEMP_FAILURE_RETRY(open(path.c_str(), flags, mode)); |
Dan Albert | aac6b7c | 2015-03-16 10:08:46 -0700 | [diff] [blame] | 88 | if (fd == -1) { |
| 89 | ALOGE("android::WriteStringToFile open failed: %s", strerror(errno)); |
| 90 | return false; |
| 91 | } |
| 92 | |
| 93 | // We do an explicit fchmod here because we assume that the caller really |
| 94 | // meant what they said and doesn't want the umask-influenced mode. |
| 95 | if (fchmod(fd, mode) == -1) { |
| 96 | ALOGE("android::WriteStringToFile fchmod failed: %s", strerror(errno)); |
| 97 | return CleanUpAfterFailedWrite(path); |
| 98 | } |
| 99 | if (fchown(fd, owner, group) == -1) { |
| 100 | ALOGE("android::WriteStringToFile fchown failed: %s", strerror(errno)); |
| 101 | return CleanUpAfterFailedWrite(path); |
| 102 | } |
| 103 | if (!WriteStringToFd(content, fd)) { |
| 104 | ALOGE("android::WriteStringToFile write failed: %s", strerror(errno)); |
| 105 | return CleanUpAfterFailedWrite(path); |
| 106 | } |
Nick Kralevich | 8292130 | 2015-05-20 08:59:21 -0700 | [diff] [blame] | 107 | close(fd); |
Dan Albert | aac6b7c | 2015-03-16 10:08:46 -0700 | [diff] [blame] | 108 | return true; |
| 109 | } |
| 110 | #endif |
| 111 | |
| 112 | bool WriteStringToFile(const std::string& content, const std::string& path) { |
Elliott Hughes | d5f8ae6 | 2015-09-01 13:35:44 -0700 | [diff] [blame] | 113 | int flags = O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC | O_NOFOLLOW | O_BINARY; |
| 114 | int fd = TEMP_FAILURE_RETRY(open(path.c_str(), flags, DEFFILEMODE)); |
Dan Albert | aac6b7c | 2015-03-16 10:08:46 -0700 | [diff] [blame] | 115 | if (fd == -1) { |
| 116 | return false; |
| 117 | } |
| 118 | |
| 119 | bool result = WriteStringToFd(content, fd); |
Nick Kralevich | 8292130 | 2015-05-20 08:59:21 -0700 | [diff] [blame] | 120 | close(fd); |
Dan Albert | aac6b7c | 2015-03-16 10:08:46 -0700 | [diff] [blame] | 121 | return result || CleanUpAfterFailedWrite(path); |
| 122 | } |
| 123 | |
Elliott Hughes | 20abc87 | 2015-04-24 21:57:16 -0700 | [diff] [blame] | 124 | bool ReadFully(int fd, void* data, size_t byte_count) { |
| 125 | uint8_t* p = reinterpret_cast<uint8_t*>(data); |
| 126 | size_t remaining = byte_count; |
| 127 | while (remaining > 0) { |
| 128 | ssize_t n = TEMP_FAILURE_RETRY(read(fd, p, remaining)); |
| 129 | if (n <= 0) return false; |
| 130 | p += n; |
| 131 | remaining -= n; |
| 132 | } |
| 133 | return true; |
| 134 | } |
| 135 | |
| 136 | bool WriteFully(int fd, const void* data, size_t byte_count) { |
| 137 | const uint8_t* p = reinterpret_cast<const uint8_t*>(data); |
| 138 | size_t remaining = byte_count; |
| 139 | while (remaining > 0) { |
| 140 | ssize_t n = TEMP_FAILURE_RETRY(write(fd, p, remaining)); |
| 141 | if (n == -1) return false; |
| 142 | p += n; |
| 143 | remaining -= n; |
| 144 | } |
| 145 | return true; |
| 146 | } |
| 147 | |
Dan Albert | aac6b7c | 2015-03-16 10:08:46 -0700 | [diff] [blame] | 148 | } // namespace base |
| 149 | } // namespace android |