| /* |
| * 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 "util.h" |
| |
| #include <ctype.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <pwd.h> |
| #include <stdarg.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/socket.h> |
| #include <sys/un.h> |
| #include <time.h> |
| #include <unistd.h> |
| |
| #include <thread> |
| |
| #include <android-base/file.h> |
| #include <android-base/logging.h> |
| #include <android-base/properties.h> |
| #include <android-base/stringprintf.h> |
| #include <android-base/strings.h> |
| #include <android-base/unique_fd.h> |
| #include <cutils/android_reboot.h> |
| #include <cutils/sockets.h> |
| #include <selinux/android.h> |
| |
| #include "reboot.h" |
| |
| #ifdef _INIT_INIT_H |
| #error "Do not include init.h in files used by ueventd or watchdogd; it will expose init's globals" |
| #endif |
| |
| using android::base::boot_clock; |
| using namespace std::literals::string_literals; |
| |
| // DecodeUid() - 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. |
| bool DecodeUid(const std::string& name, uid_t* uid, std::string* err) { |
| *uid = UINT_MAX; |
| *err = ""; |
| |
| if (isalpha(name[0])) { |
| passwd* pwd = getpwnam(name.c_str()); |
| if (!pwd) { |
| *err = "getpwnam failed: "s + strerror(errno); |
| return false; |
| } |
| *uid = pwd->pw_uid; |
| return true; |
| } |
| |
| errno = 0; |
| uid_t result = static_cast<uid_t>(strtoul(name.c_str(), 0, 0)); |
| if (errno) { |
| *err = "strtoul failed: "s + strerror(errno); |
| return false; |
| } |
| *uid = result; |
| return true; |
| } |
| |
| /* |
| * CreateSocket - 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 CreateSocket(const char* name, int type, bool passcred, mode_t perm, uid_t uid, gid_t gid, |
| const char* socketcon, selabel_handle* sehandle) { |
| if (socketcon) { |
| if (setsockcreatecon(socketcon) == -1) { |
| PLOG(ERROR) << "setsockcreatecon(\"" << socketcon << "\") failed"; |
| return -1; |
| } |
| } |
| |
| android::base::unique_fd fd(socket(PF_UNIX, type, 0)); |
| if (fd < 0) { |
| PLOG(ERROR) << "Failed to open socket '" << name << "'"; |
| return -1; |
| } |
| |
| if (socketcon) setsockcreatecon(NULL); |
| |
| struct sockaddr_un addr; |
| memset(&addr, 0 , sizeof(addr)); |
| addr.sun_family = AF_UNIX; |
| snprintf(addr.sun_path, sizeof(addr.sun_path), ANDROID_SOCKET_DIR"/%s", |
| name); |
| |
| if ((unlink(addr.sun_path) != 0) && (errno != ENOENT)) { |
| PLOG(ERROR) << "Failed to unlink old socket '" << name << "'"; |
| return -1; |
| } |
| |
| char *filecon = NULL; |
| if (sehandle) { |
| if (selabel_lookup(sehandle, &filecon, addr.sun_path, S_IFSOCK) == 0) { |
| setfscreatecon(filecon); |
| } |
| } |
| |
| if (passcred) { |
| int on = 1; |
| if (setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on))) { |
| PLOG(ERROR) << "Failed to set SO_PASSCRED '" << name << "'"; |
| return -1; |
| } |
| } |
| |
| int ret = bind(fd, (struct sockaddr *) &addr, sizeof (addr)); |
| int savederrno = errno; |
| |
| setfscreatecon(NULL); |
| freecon(filecon); |
| |
| if (ret) { |
| errno = savederrno; |
| PLOG(ERROR) << "Failed to bind socket '" << name << "'"; |
| goto out_unlink; |
| } |
| |
| if (lchown(addr.sun_path, uid, gid)) { |
| PLOG(ERROR) << "Failed to lchown socket '" << addr.sun_path << "'"; |
| goto out_unlink; |
| } |
| if (fchmodat(AT_FDCWD, addr.sun_path, perm, AT_SYMLINK_NOFOLLOW)) { |
| 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.release(); |
| |
| out_unlink: |
| unlink(addr.sun_path); |
| return -1; |
| } |
| |
| bool ReadFile(const std::string& path, std::string* content, std::string* err) { |
| content->clear(); |
| *err = ""; |
| |
| android::base::unique_fd fd( |
| TEMP_FAILURE_RETRY(open(path.c_str(), O_RDONLY | O_NOFOLLOW | O_CLOEXEC))); |
| if (fd == -1) { |
| *err = "Unable to open '" + path + "': " + strerror(errno); |
| return false; |
| } |
| |
| // For security reasons, disallow world-writable |
| // or group-writable files. |
| struct stat sb; |
| if (fstat(fd, &sb) == -1) { |
| *err = "fstat failed for '" + path + "': " + strerror(errno); |
| return false; |
| } |
| if ((sb.st_mode & (S_IWGRP | S_IWOTH)) != 0) { |
| *err = "Skipping insecure file '" + path + "'"; |
| return false; |
| } |
| |
| if (!android::base::ReadFdToString(fd, content)) { |
| *err = "Unable to read '" + path + "': " + strerror(errno); |
| return false; |
| } |
| return true; |
| } |
| |
| bool WriteFile(const std::string& path, const std::string& content, std::string* err) { |
| *err = ""; |
| |
| android::base::unique_fd fd(TEMP_FAILURE_RETRY( |
| open(path.c_str(), O_WRONLY | O_CREAT | O_NOFOLLOW | O_TRUNC | O_CLOEXEC, 0600))); |
| if (fd == -1) { |
| *err = "Unable to open '" + path + "': " + strerror(errno); |
| return false; |
| } |
| if (!android::base::WriteStringToFd(content, fd)) { |
| *err = "Unable to write to '" + path + "': " + strerror(errno); |
| return false; |
| } |
| return true; |
| } |
| |
| int mkdir_recursive(const std::string& path, mode_t mode, selabel_handle* sehandle) { |
| std::string::size_type slash = 0; |
| while ((slash = path.find('/', slash + 1)) != std::string::npos) { |
| auto directory = path.substr(0, slash); |
| struct stat info; |
| if (stat(directory.c_str(), &info) != 0) { |
| auto ret = make_dir(directory.c_str(), mode, sehandle); |
| if (ret && errno != EEXIST) return ret; |
| } |
| } |
| auto ret = make_dir(path.c_str(), mode, sehandle); |
| if (ret && errno != EEXIST) return ret; |
| return 0; |
| } |
| |
| int wait_for_file(const char* filename, std::chrono::nanoseconds timeout) { |
| boot_clock::time_point timeout_time = boot_clock::now() + timeout; |
| while (boot_clock::now() < timeout_time) { |
| struct stat sb; |
| if (stat(filename, &sb) != -1) return 0; |
| |
| std::this_thread::sleep_for(10ms); |
| } |
| return -1; |
| } |
| |
| 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, selabel_handle* sehandle) { |
| 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; |
| } |
| |
| /* |
| * 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 = android::base::GetProperty(prop_name, ""); |
| 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; |
| } |
| |
| void panic() { |
| LOG(ERROR) << "panic: rebooting to bootloader"; |
| DoReboot(ANDROID_RB_RESTART2, "reboot", "bootloader", false); |
| } |
| |
| std::ostream& operator<<(std::ostream& os, const Timer& t) { |
| os << t.duration_s() << " seconds"; |
| return os; |
| } |
| |
| // Reads the content of device tree file under kAndroidDtDir directory. |
| // Returns true if the read is success, false otherwise. |
| bool read_android_dt_file(const std::string& sub_path, std::string* dt_content) { |
| const std::string file_name = kAndroidDtDir + sub_path; |
| if (android::base::ReadFileToString(file_name, dt_content)) { |
| if (!dt_content->empty()) { |
| dt_content->pop_back(); // Trims the trailing '\0' out. |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| bool is_android_dt_value_expected(const std::string& sub_path, const std::string& expected_content) { |
| std::string dt_content; |
| if (read_android_dt_file(sub_path, &dt_content)) { |
| if (dt_content == expected_content) { |
| return true; |
| } |
| } |
| return false; |
| } |