| /* |
| * 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 <pwd.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 <android-base/file.h> |
| #include <android-base/logging.h> |
| #include <android-base/strings.h> |
| |
| /* for ANDROID_SOCKET_* */ |
| #include <cutils/sockets.h> |
| #include <android-base/stringprintf.h> |
| |
| #include "init.h" |
| #include "log.h" |
| #include "property_service.h" |
| #include "util.h" |
| |
| static unsigned int do_decode_uid(const char *s) |
| { |
| unsigned int v; |
| |
| if (!s || *s == '\0') |
| return UINT_MAX; |
| |
| if (isalpha(s[0])) { |
| struct passwd* pwd = getpwnam(s); |
| if (!pwd) |
| return UINT_MAX; |
| return pwd->pw_uid; |
| } |
| |
| errno = 0; |
| v = (unsigned int) strtoul(s, 0, 0); |
| if (errno) |
| return UINT_MAX; |
| return v; |
| } |
| |
| /* |
| * decode_uid - decodes and returns the given string, which can be either the |
| * numeric or name representation, into the integer uid or gid. Returns |
| * UINT_MAX on error. |
| */ |
| unsigned int decode_uid(const char *s) { |
| unsigned int v = do_decode_uid(s); |
| if (v == UINT_MAX) { |
| LOG(ERROR) << "decode_uid: Unable to find UID for '" << s << "'; returning UINT_MAX"; |
| } |
| 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, savederrno; |
| char *filecon; |
| |
| if (socketcon) { |
| if (setsockcreatecon(socketcon) == -1) { |
| PLOG(ERROR) << "setsockcreatecon(\"" << socketcon << "\") failed"; |
| return -1; |
| } |
| } |
| |
| fd = socket(PF_UNIX, type, 0); |
| if (fd < 0) { |
| PLOG(ERROR) << "Failed to open socket '" << name << "'"; |
| 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) { |
| PLOG(ERROR) << "Failed to unlink old socket '" << name << "'"; |
| 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)); |
| savederrno = errno; |
| |
| setfscreatecon(NULL); |
| freecon(filecon); |
| |
| if (ret) { |
| errno = savederrno; |
| PLOG(ERROR) << "Failed to bind socket '" << name << "'"; |
| goto out_unlink; |
| } |
| |
| ret = lchown(addr.sun_path, uid, gid); |
| if (ret) { |
| PLOG(ERROR) << "Failed to lchown socket '" << addr.sun_path << "'"; |
| goto out_unlink; |
| } |
| ret = fchmodat(AT_FDCWD, addr.sun_path, perm, AT_SYMLINK_NOFOLLOW); |
| if (ret) { |
| PLOG(ERROR) << "Failed to fchmodat socket '" << addr.sun_path << "'"; |
| goto out_unlink; |
| } |
| |
| LOG(INFO) << "Created socket '" << addr.sun_path << "'" |
| << ", mode " << std::oct << perm << std::dec |
| << ", user " << uid |
| << ", group " << 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) { |
| PLOG(ERROR) << "fstat failed for '" << path << "'"; |
| return false; |
| } |
| if ((sb.st_mode & (S_IWGRP | S_IWOTH)) != 0) { |
| PLOG(ERROR) << "skipping insecure file '" << path << "'"; |
| return false; |
| } |
| |
| bool okay = android::base::ReadFdToString(fd, content); |
| close(fd); |
| 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) { |
| PLOG(ERROR) << "write_file: Unable to open '" << path << "'"; |
| return -1; |
| } |
| int result = android::base::WriteStringToFd(content, fd) ? 0 : -1; |
| if (result == -1) { |
| PLOG(ERROR) << "write_file: Unable to write to '" << path << "'"; |
| } |
| close(fd); |
| return result; |
| } |
| |
| 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) { |
| LOG(ERROR) << "path too long for mkdir_recursive"; |
| 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++ = '_'; |
| } |
| } |
| |
| int wait_for_file(const char *filename, int timeout) |
| { |
| struct stat info; |
| uint64_t timeout_time_ns = gettime_ns() + timeout * UINT64_C(1000000000); |
| int ret = -1; |
| |
| while (gettime_ns() < timeout_time_ns && ((ret = stat(filename, &info)) < 0)) |
| usleep(10000); |
| |
| return ret; |
| } |
| |
| void import_kernel_cmdline(bool in_qemu, |
| const std::function<void(const std::string&, const std::string&, bool)>& fn) { |
| std::string cmdline; |
| android::base::ReadFileToString("/proc/cmdline", &cmdline); |
| |
| for (const auto& entry : android::base::Split(android::base::Trim(cmdline), " ")) { |
| std::vector<std::string> pieces = android::base::Split(entry, "="); |
| if (pieces.size() == 2) { |
| fn(pieces[0], pieces[1], in_qemu); |
| } |
| } |
| } |
| |
| 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); |
| } |
| |
| int restorecon_recursive_skipce(const char* pathname) |
| { |
| return selinux_android_restorecon(pathname, |
| SELINUX_ANDROID_RESTORECON_RECURSE | SELINUX_ANDROID_RESTORECON_SKIPCE); |
| } |
| |
| /* |
| * Writes hex_len hex characters (1/2 byte) to hex from bytes. |
| */ |
| std::string bytes_to_hex(const uint8_t* bytes, size_t bytes_len) { |
| std::string hex("0x"); |
| for (size_t i = 0; i < bytes_len; i++) |
| android::base::StringAppendF(&hex, "%02x", bytes[i]); |
| return hex; |
| } |
| |
| /* |
| * Returns true is pathname is a directory |
| */ |
| bool is_dir(const char* pathname) { |
| struct stat info; |
| if (stat(pathname, &info) == -1) { |
| return false; |
| } |
| return S_ISDIR(info.st_mode); |
| } |
| |
| bool expand_props(const std::string& src, std::string* dst) { |
| const char* src_ptr = src.c_str(); |
| |
| if (!dst) { |
| return false; |
| } |
| |
| /* - variables can either be $x.y or ${x.y}, in case they are only part |
| * of the string. |
| * - will accept $$ as a literal $. |
| * - no nested property expansion, i.e. ${foo.${bar}} is not supported, |
| * bad things will happen |
| * - ${x.y:-default} will return default value if property empty. |
| */ |
| while (*src_ptr) { |
| const char* c; |
| |
| c = strchr(src_ptr, '$'); |
| if (!c) { |
| dst->append(src_ptr); |
| return true; |
| } |
| |
| dst->append(src_ptr, c); |
| c++; |
| |
| if (*c == '$') { |
| dst->push_back(*(c++)); |
| src_ptr = c; |
| continue; |
| } else if (*c == '\0') { |
| return true; |
| } |
| |
| std::string prop_name; |
| std::string def_val; |
| if (*c == '{') { |
| c++; |
| const char* end = strchr(c, '}'); |
| if (!end) { |
| // failed to find closing brace, abort. |
| LOG(ERROR) << "unexpected end of string in '" << src << "', looking for }"; |
| return false; |
| } |
| prop_name = std::string(c, end); |
| c = end + 1; |
| size_t def = prop_name.find(":-"); |
| if (def < prop_name.size()) { |
| def_val = prop_name.substr(def + 2); |
| prop_name = prop_name.substr(0, def); |
| } |
| } else { |
| prop_name = c; |
| LOG(ERROR) << "using deprecated syntax for specifying property '" << c << "', use ${name} instead"; |
| c += prop_name.size(); |
| } |
| |
| if (prop_name.empty()) { |
| LOG(ERROR) << "invalid zero-length property name in '" << src << "'"; |
| return false; |
| } |
| |
| std::string prop_val = property_get(prop_name.c_str()); |
| if (prop_val.empty()) { |
| if (def_val.empty()) { |
| LOG(ERROR) << "property '" << prop_name << "' doesn't exist while expanding '" << src << "'"; |
| return false; |
| } |
| prop_val = def_val; |
| } |
| |
| dst->append(prop_val); |
| src_ptr = c; |
| } |
| |
| return true; |
| } |