fs.c revision 6de702679089fab13ec2d4d435054f68688df545
19685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey/* 29685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey * Copyright (C) 2012 The Android Open Source Project 39685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey * 49685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey * Licensed under the Apache License, Version 2.0 (the "License"); 59685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey * you may not use this file except in compliance with the License. 69685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey * You may obtain a copy of the License at 79685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey * 89685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey * http://www.apache.org/licenses/LICENSE-2.0 99685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey * 109685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey * Unless required by applicable law or agreed to in writing, software 119685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey * distributed under the License is distributed on an "AS IS" BASIS, 129685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 139685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey * See the License for the specific language governing permissions and 149685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey * limitations under the License. 159685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey */ 169685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey 17ddb173394430a7b55b0c24896a843556f5f8de7aJeff Sharkey#define LOG_TAG "cutils" 18ddb173394430a7b55b0c24896a843556f5f8de7aJeff Sharkey 199685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey#include <cutils/fs.h> 209685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey#include <cutils/log.h> 219685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey 229685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey#include <sys/types.h> 239685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey#include <sys/stat.h> 249685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey#include <fcntl.h> 259685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey#include <unistd.h> 269685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey#include <errno.h> 279685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey#include <string.h> 289685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey#include <limits.h> 299685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey 309685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey#define ALL_PERMS (S_ISUID | S_ISGID | S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO) 319685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey#define BUF_SIZE 64 329685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey 339685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkeyint fs_prepare_dir(const char* path, mode_t mode, uid_t uid, gid_t gid) { 349685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey // Check if path needs to be created 359685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey struct stat sb; 36ddb173394430a7b55b0c24896a843556f5f8de7aJeff Sharkey if (TEMP_FAILURE_RETRY(lstat(path, &sb)) == -1) { 379685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey if (errno == ENOENT) { 389685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey goto create; 399685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey } else { 40ddb173394430a7b55b0c24896a843556f5f8de7aJeff Sharkey ALOGE("Failed to lstat(%s): %s", path, strerror(errno)); 419685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey return -1; 429685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey } 439685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey } 449685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey 459685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey // Exists, verify status 469685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey if (!S_ISDIR(sb.st_mode)) { 479685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey ALOGE("Not a directory: %s", path); 489685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey return -1; 499685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey } 509685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey if (((sb.st_mode & ALL_PERMS) == mode) && (sb.st_uid == uid) && (sb.st_gid == gid)) { 519685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey return 0; 529685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey } else { 539685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey goto fixup; 549685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey } 559685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey 569685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkeycreate: 57ddb173394430a7b55b0c24896a843556f5f8de7aJeff Sharkey if (TEMP_FAILURE_RETRY(mkdir(path, mode)) == -1) { 589685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey ALOGE("Failed to mkdir(%s): %s", path, strerror(errno)); 599685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey return -1; 609685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey } 619685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey 629685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkeyfixup: 63ddb173394430a7b55b0c24896a843556f5f8de7aJeff Sharkey if (TEMP_FAILURE_RETRY(chmod(path, mode)) == -1) { 64ddb173394430a7b55b0c24896a843556f5f8de7aJeff Sharkey ALOGE("Failed to chmod(%s, %d): %s", path, mode, strerror(errno)); 659685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey return -1; 669685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey } 67ddb173394430a7b55b0c24896a843556f5f8de7aJeff Sharkey if (TEMP_FAILURE_RETRY(chown(path, uid, gid)) == -1) { 689685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey ALOGE("Failed to chown(%s, %d, %d): %s", path, uid, gid, strerror(errno)); 699685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey return -1; 709685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey } 719685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey 729685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey return 0; 739685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey} 749685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey 759685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkeyint fs_read_atomic_int(const char* path, int* out_value) { 766de702679089fab13ec2d4d435054f68688df545Jeff Sharkey int fd = TEMP_FAILURE_RETRY(open(path, O_RDONLY)); 779685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey if (fd == -1) { 789685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey ALOGE("Failed to read %s: %s", path, strerror(errno)); 799685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey return -1; 809685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey } 819685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey 829685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey char buf[BUF_SIZE]; 836de702679089fab13ec2d4d435054f68688df545Jeff Sharkey if (TEMP_FAILURE_RETRY(read(fd, buf, BUF_SIZE)) == -1) { 849685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey ALOGE("Failed to read %s: %s", path, strerror(errno)); 859685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey goto fail; 869685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey } 879685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey if (sscanf(buf, "%d", out_value) != 1) { 889685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey ALOGE("Failed to parse %s: %s", path, strerror(errno)); 899685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey goto fail; 909685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey } 919685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey close(fd); 929685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey return 0; 939685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey 949685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkeyfail: 959685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey close(fd); 969685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey *out_value = -1; 979685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey return -1; 989685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey} 999685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey 1009685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkeyint fs_write_atomic_int(const char* path, int value) { 1019685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey char temp[PATH_MAX]; 1029685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey if (snprintf(temp, PATH_MAX, "%s.XXXXXX", path) >= PATH_MAX) { 1039685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey ALOGE("Path too long"); 1049685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey return -1; 1059685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey } 1069685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey 1076de702679089fab13ec2d4d435054f68688df545Jeff Sharkey int fd = TEMP_FAILURE_RETRY(mkstemp(temp)); 1089685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey if (fd == -1) { 1099685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey ALOGE("Failed to open %s: %s", temp, strerror(errno)); 1109685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey return -1; 1119685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey } 1129685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey 1139685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey char buf[BUF_SIZE]; 1149685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey int len = snprintf(buf, BUF_SIZE, "%d", value) + 1; 1159685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey if (len > BUF_SIZE) { 1169685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey ALOGE("Value %d too large: %s", value, strerror(errno)); 1179685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey goto fail; 1189685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey } 1196de702679089fab13ec2d4d435054f68688df545Jeff Sharkey if (TEMP_FAILURE_RETRY(write(fd, buf, len)) < len) { 1209685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey ALOGE("Failed to write %s: %s", temp, strerror(errno)); 1219685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey goto fail; 1229685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey } 1239685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey if (close(fd) == -1) { 1249685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey ALOGE("Failed to close %s: %s", temp, strerror(errno)); 1259685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey goto fail_closed; 1269685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey } 1279685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey 1289685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey if (rename(temp, path) == -1) { 1299685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey ALOGE("Failed to rename %s to %s: %s", temp, path, strerror(errno)); 1309685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey goto fail_closed; 1319685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey } 1329685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey 1339685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey return 0; 1349685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey 1359685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkeyfail: 1369685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey close(fd); 1379685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkeyfail_closed: 1389685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey unlink(temp); 1399685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey return -1; 1409685194fc94510a33201aee9b80c23f206ccfe67Jeff Sharkey} 141