| /* |
| * Copyright (C) 2008 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 <stdarg.h> |
| #include <stdlib.h> |
| #include <stdio.h> |
| #include <string.h> |
| #include <fcntl.h> |
| #include <ctype.h> |
| #include <errno.h> |
| #include <time.h> |
| #include <ftw.h> |
| |
| #include <selinux/label.h> |
| #include <selinux/android.h> |
| |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| #include <sys/socket.h> |
| #include <sys/un.h> |
| |
| #include <base/file.h> |
| |
| /* for ANDROID_SOCKET_* */ |
| #include <cutils/sockets.h> |
| |
| #include <private/android_filesystem_config.h> |
| |
| #include "init.h" |
| #include "log.h" |
| #include "util.h" |
| |
| /* |
| * android_name_to_id - returns the integer uid/gid associated with the given |
| * name, or -1U on error. |
| */ |
| static unsigned int android_name_to_id(const char *name) |
| { |
| const struct android_id_info *info = android_ids; |
| unsigned int n; |
| |
| for (n = 0; n < android_id_count; n++) { |
| if (!strcmp(info[n].name, name)) |
| return info[n].aid; |
| } |
| |
| return -1U; |
| } |
| |
| /* |
| * decode_uid - decodes and returns the given string, which can be either the |
| * numeric or name representation, into the integer uid or gid. Returns -1U on |
| * error. |
| */ |
| unsigned int decode_uid(const char *s) |
| { |
| unsigned int v; |
| |
| if (!s || *s == '\0') |
| return -1U; |
| if (isalpha(s[0])) |
| return android_name_to_id(s); |
| |
| errno = 0; |
| v = (unsigned int) strtoul(s, 0, 0); |
| if (errno) |
| return -1U; |
| return v; |
| } |
| |
| /* |
| * create_socket - creates a Unix domain socket in ANDROID_SOCKET_DIR |
| * ("/dev/socket") as dictated in init.rc. This socket is inherited by the |
| * daemon. We communicate the file descriptor's value via the environment |
| * variable ANDROID_SOCKET_ENV_PREFIX<name> ("ANDROID_SOCKET_foo"). |
| */ |
| int create_socket(const char *name, int type, mode_t perm, uid_t uid, |
| gid_t gid, const char *socketcon) |
| { |
| struct sockaddr_un addr; |
| int fd, ret; |
| char *filecon; |
| |
| if (socketcon) |
| setsockcreatecon(socketcon); |
| |
| fd = socket(PF_UNIX, type, 0); |
| if (fd < 0) { |
| ERROR("Failed to open socket '%s': %s\n", name, strerror(errno)); |
| return -1; |
| } |
| |
| if (socketcon) |
| setsockcreatecon(NULL); |
| |
| memset(&addr, 0 , sizeof(addr)); |
| addr.sun_family = AF_UNIX; |
| snprintf(addr.sun_path, sizeof(addr.sun_path), ANDROID_SOCKET_DIR"/%s", |
| name); |
| |
| ret = unlink(addr.sun_path); |
| if (ret != 0 && errno != ENOENT) { |
| ERROR("Failed to unlink old socket '%s': %s\n", name, strerror(errno)); |
| goto out_close; |
| } |
| |
| filecon = NULL; |
| if (sehandle) { |
| ret = selabel_lookup(sehandle, &filecon, addr.sun_path, S_IFSOCK); |
| if (ret == 0) |
| setfscreatecon(filecon); |
| } |
| |
| ret = bind(fd, (struct sockaddr *) &addr, sizeof (addr)); |
| if (ret) { |
| ERROR("Failed to bind socket '%s': %s\n", name, strerror(errno)); |
| goto out_unlink; |
| } |
| |
| setfscreatecon(NULL); |
| freecon(filecon); |
| |
| chown(addr.sun_path, uid, gid); |
| chmod(addr.sun_path, perm); |
| |
| INFO("Created socket '%s' with mode '%o', user '%d', group '%d'\n", |
| addr.sun_path, perm, uid, gid); |
| |
| return fd; |
| |
| out_unlink: |
| unlink(addr.sun_path); |
| out_close: |
| close(fd); |
| return -1; |
| } |
| |
| bool read_file(const char* path, std::string* content) { |
| content->clear(); |
| |
| int fd = TEMP_FAILURE_RETRY(open(path, O_RDONLY|O_NOFOLLOW|O_CLOEXEC)); |
| if (fd == -1) { |
| return false; |
| } |
| |
| // For security reasons, disallow world-writable |
| // or group-writable files. |
| struct stat sb; |
| if (fstat(fd, &sb) == -1) { |
| ERROR("fstat failed for '%s': %s\n", path, strerror(errno)); |
| return false; |
| } |
| if ((sb.st_mode & (S_IWGRP | S_IWOTH)) != 0) { |
| ERROR("skipping insecure file '%s'\n", path); |
| return false; |
| } |
| |
| bool okay = android::base::ReadFdToString(fd, content); |
| TEMP_FAILURE_RETRY(close(fd)); |
| if (okay) { |
| content->append("\n", 1); |
| } |
| return okay; |
| } |
| |
| int write_file(const char* path, const char* content) { |
| int fd = TEMP_FAILURE_RETRY(open(path, O_WRONLY|O_CREAT|O_NOFOLLOW|O_CLOEXEC, 0600)); |
| if (fd == -1) { |
| NOTICE("write_file: Unable to open '%s': %s\n", path, strerror(errno)); |
| return -1; |
| } |
| int result = android::base::WriteStringToFd(content, fd) ? 0 : -1; |
| if (result == -1) { |
| NOTICE("write_file: Unable to write to '%s': %s\n", path, strerror(errno)); |
| } |
| TEMP_FAILURE_RETRY(close(fd)); |
| return result; |
| } |
| |
| #define MAX_MTD_PARTITIONS 16 |
| |
| static struct { |
| char name[16]; |
| int number; |
| } mtd_part_map[MAX_MTD_PARTITIONS]; |
| |
| static int mtd_part_count = -1; |
| |
| static void find_mtd_partitions(void) |
| { |
| int fd; |
| char buf[1024]; |
| char *pmtdbufp; |
| ssize_t pmtdsize; |
| int r; |
| |
| fd = open("/proc/mtd", O_RDONLY|O_CLOEXEC); |
| if (fd < 0) |
| return; |
| |
| buf[sizeof(buf) - 1] = '\0'; |
| pmtdsize = read(fd, buf, sizeof(buf) - 1); |
| pmtdbufp = buf; |
| while (pmtdsize > 0) { |
| int mtdnum, mtdsize, mtderasesize; |
| char mtdname[16]; |
| mtdname[0] = '\0'; |
| mtdnum = -1; |
| r = sscanf(pmtdbufp, "mtd%d: %x %x %15s", |
| &mtdnum, &mtdsize, &mtderasesize, mtdname); |
| if ((r == 4) && (mtdname[0] == '"')) { |
| char *x = strchr(mtdname + 1, '"'); |
| if (x) { |
| *x = 0; |
| } |
| INFO("mtd partition %d, %s\n", mtdnum, mtdname + 1); |
| if (mtd_part_count < MAX_MTD_PARTITIONS) { |
| strcpy(mtd_part_map[mtd_part_count].name, mtdname + 1); |
| mtd_part_map[mtd_part_count].number = mtdnum; |
| mtd_part_count++; |
| } else { |
| ERROR("too many mtd partitions\n"); |
| } |
| } |
| while (pmtdsize > 0 && *pmtdbufp != '\n') { |
| pmtdbufp++; |
| pmtdsize--; |
| } |
| if (pmtdsize > 0) { |
| pmtdbufp++; |
| pmtdsize--; |
| } |
| } |
| close(fd); |
| } |
| |
| int mtd_name_to_number(const char *name) |
| { |
| int n; |
| if (mtd_part_count < 0) { |
| mtd_part_count = 0; |
| find_mtd_partitions(); |
| } |
| for (n = 0; n < mtd_part_count; n++) { |
| if (!strcmp(name, mtd_part_map[n].name)) { |
| return mtd_part_map[n].number; |
| } |
| } |
| return -1; |
| } |
| |
| time_t gettime() { |
| timespec now; |
| clock_gettime(CLOCK_MONOTONIC, &now); |
| return now.tv_sec; |
| } |
| |
| uint64_t gettime_ns() { |
| timespec now; |
| clock_gettime(CLOCK_MONOTONIC, &now); |
| return static_cast<uint64_t>(now.tv_sec) * UINT64_C(1000000000) + now.tv_nsec; |
| } |
| |
| int mkdir_recursive(const char *pathname, mode_t mode) |
| { |
| char buf[128]; |
| const char *slash; |
| const char *p = pathname; |
| int width; |
| int ret; |
| struct stat info; |
| |
| while ((slash = strchr(p, '/')) != NULL) { |
| width = slash - pathname; |
| p = slash + 1; |
| if (width < 0) |
| break; |
| if (width == 0) |
| continue; |
| if ((unsigned int)width > sizeof(buf) - 1) { |
| ERROR("path too long for mkdir_recursive\n"); |
| return -1; |
| } |
| memcpy(buf, pathname, width); |
| buf[width] = 0; |
| if (stat(buf, &info) != 0) { |
| ret = make_dir(buf, mode); |
| if (ret && errno != EEXIST) |
| return ret; |
| } |
| } |
| ret = make_dir(pathname, mode); |
| if (ret && errno != EEXIST) |
| return ret; |
| return 0; |
| } |
| |
| /* |
| * replaces any unacceptable characters with '_', the |
| * length of the resulting string is equal to the input string |
| */ |
| void sanitize(char *s) |
| { |
| const char* accept = |
| "abcdefghijklmnopqrstuvwxyz" |
| "ABCDEFGHIJKLMNOPQRSTUVWXYZ" |
| "0123456789" |
| "_-."; |
| |
| if (!s) |
| return; |
| |
| while (*s) { |
| s += strspn(s, accept); |
| if (*s) *s++ = '_'; |
| } |
| } |
| |
| void make_link(const char *oldpath, const char *newpath) |
| { |
| int ret; |
| char buf[256]; |
| char *slash; |
| int width; |
| |
| slash = strrchr(newpath, '/'); |
| if (!slash) |
| return; |
| width = slash - newpath; |
| if (width <= 0 || width > (int)sizeof(buf) - 1) |
| return; |
| memcpy(buf, newpath, width); |
| buf[width] = 0; |
| ret = mkdir_recursive(buf, 0755); |
| if (ret) |
| ERROR("Failed to create directory %s: %s (%d)\n", buf, strerror(errno), errno); |
| |
| ret = symlink(oldpath, newpath); |
| if (ret && errno != EEXIST) |
| ERROR("Failed to symlink %s to %s: %s (%d)\n", oldpath, newpath, strerror(errno), errno); |
| } |
| |
| void remove_link(const char *oldpath, const char *newpath) |
| { |
| char path[256]; |
| ssize_t ret; |
| ret = readlink(newpath, path, sizeof(path) - 1); |
| if (ret <= 0) |
| return; |
| path[ret] = 0; |
| if (!strcmp(path, oldpath)) |
| unlink(newpath); |
| } |
| |
| int wait_for_file(const char *filename, int timeout) |
| { |
| struct stat info; |
| time_t timeout_time = gettime() + timeout; |
| int ret = -1; |
| |
| while (gettime() < timeout_time && ((ret = stat(filename, &info)) < 0)) |
| usleep(10000); |
| |
| return ret; |
| } |
| |
| void open_devnull_stdio(void) |
| { |
| // Try to avoid the mknod() call if we can. Since SELinux makes |
| // a /dev/null replacement available for free, let's use it. |
| int fd = open("/sys/fs/selinux/null", O_RDWR); |
| if (fd == -1) { |
| // OOPS, /sys/fs/selinux/null isn't available, likely because |
| // /sys/fs/selinux isn't mounted. Fall back to mknod. |
| static const char *name = "/dev/__null__"; |
| if (mknod(name, S_IFCHR | 0600, (1 << 8) | 3) == 0) { |
| fd = open(name, O_RDWR); |
| unlink(name); |
| } |
| if (fd == -1) { |
| exit(1); |
| } |
| } |
| |
| dup2(fd, 0); |
| dup2(fd, 1); |
| dup2(fd, 2); |
| if (fd > 2) { |
| close(fd); |
| } |
| } |
| |
| void import_kernel_cmdline(bool in_qemu, std::function<void(char*,bool)> import_kernel_nv) |
| { |
| char cmdline[2048]; |
| char *ptr; |
| int fd; |
| |
| fd = open("/proc/cmdline", O_RDONLY | O_CLOEXEC); |
| if (fd >= 0) { |
| int n = read(fd, cmdline, sizeof(cmdline) - 1); |
| if (n < 0) n = 0; |
| |
| /* get rid of trailing newline, it happens */ |
| if (n > 0 && cmdline[n-1] == '\n') n--; |
| |
| cmdline[n] = 0; |
| close(fd); |
| } else { |
| cmdline[0] = 0; |
| } |
| |
| ptr = cmdline; |
| while (ptr && *ptr) { |
| char *x = strchr(ptr, ' '); |
| if (x != 0) *x++ = 0; |
| import_kernel_nv(ptr, in_qemu); |
| ptr = x; |
| } |
| } |
| |
| int make_dir(const char *path, mode_t mode) |
| { |
| int rc; |
| |
| char *secontext = NULL; |
| |
| if (sehandle) { |
| selabel_lookup(sehandle, &secontext, path, mode); |
| setfscreatecon(secontext); |
| } |
| |
| rc = mkdir(path, mode); |
| |
| if (secontext) { |
| int save_errno = errno; |
| freecon(secontext); |
| setfscreatecon(NULL); |
| errno = save_errno; |
| } |
| |
| return rc; |
| } |
| |
| int restorecon(const char* pathname) |
| { |
| return selinux_android_restorecon(pathname, 0); |
| } |
| |
| int restorecon_recursive(const char* pathname) |
| { |
| return selinux_android_restorecon(pathname, SELINUX_ANDROID_RESTORECON_RECURSE); |
| } |