diff options
Diffstat (limited to 'third_party/nix/src/libutil/util.cc')
| -rw-r--r-- | third_party/nix/src/libutil/util.cc | 1426 |
1 files changed, 0 insertions, 1426 deletions
diff --git a/third_party/nix/src/libutil/util.cc b/third_party/nix/src/libutil/util.cc deleted file mode 100644 index aea1e68e3c..0000000000 --- a/third_party/nix/src/libutil/util.cc +++ /dev/null @@ -1,1426 +0,0 @@ -#include "libutil/util.hh" - -#include <cctype> -#include <cerrno> -#include <climits> -#include <cstdio> -#include <cstdlib> -#include <cstring> -#include <future> -#include <iostream> -#include <sstream> -#include <thread> -#include <utility> - -#include <absl/strings/str_split.h> -#include <absl/strings/string_view.h> -#include <fcntl.h> -#include <glog/logging.h> -#include <grp.h> -#include <pwd.h> -#include <sys/ioctl.h> -#include <sys/prctl.h> -#include <sys/types.h> -#include <sys/wait.h> -#include <unistd.h> - -#include "libutil/affinity.hh" -#include "libutil/finally.hh" -#include "libutil/lazy.hh" -#include "libutil/serialise.hh" -#include "libutil/sync.hh" -#include "nix_config.h" - -namespace nix { - -const std::string nativeSystem = SYSTEM; - -BaseError& BaseError::addPrefix(const FormatOrString& fs) { - prefix_ = fs.s + prefix_; - return *this; -} - -std::string SysError::addErrno(const std::string& s) { - errNo = errno; - return s + ": " + strerror(errNo); -} - -std::optional<std::string> getEnv(const std::string& key) { - char* value = getenv(key.c_str()); - if (value == nullptr) return {}; - return std::string(value); -} - -std::map<std::string, std::string> getEnv() { - std::map<std::string, std::string> env; - for (size_t i = 0; environ[i] != nullptr; ++i) { - auto s = environ[i]; - auto eq = strchr(s, '='); - if (eq == nullptr) { - // invalid env, just keep going - continue; - } - env.emplace(std::string(s, eq), std::string(eq + 1)); - } - return env; -} - -void clearEnv() { - for (auto& name : getEnv()) { - unsetenv(name.first.c_str()); - } -} - -void replaceEnv(const std::map<std::string, std::string>& newEnv) { - clearEnv(); - for (const auto& newEnvVar : newEnv) { - setenv(newEnvVar.first.c_str(), newEnvVar.second.c_str(), 1); - } -} - -Path absPath(Path path, Path dir) { - if (path[0] != '/') { - if (dir.empty()) { -#ifdef __GNU__ - /* GNU (aka. GNU/Hurd) doesn't have any limitation on path - lengths and doesn't define `PATH_MAX'. */ - char* buf = getcwd(NULL, 0); - if (buf == NULL) -#else - char buf[PATH_MAX]; - if (getcwd(buf, sizeof(buf)) == nullptr) { -#endif - throw SysError("cannot get cwd"); - } - dir = buf; -#ifdef __GNU__ - free(buf); -#endif - } - path = dir + "/" + path; -} -return canonPath(path); -} // namespace nix - -Path canonPath(const Path& path, bool resolveSymlinks) { - assert(!path.empty()); - - std::string s; - - if (path[0] != '/') { - throw Error(format("not an absolute path: '%1%'") % path); - } - - std::string::const_iterator i = path.begin(); - std::string::const_iterator end = path.end(); - std::string temp; - - /* Count the number of times we follow a symlink and stop at some - arbitrary (but high) limit to prevent infinite loops. */ - unsigned int followCount = 0; - unsigned int maxFollow = 1024; - - while (true) { - /* Skip slashes. */ - while (i != end && *i == '/') { - i++; - } - if (i == end) { - break; - } - - /* Ignore `.'. */ - if (*i == '.' && (i + 1 == end || i[1] == '/')) { - i++; - } - - /* If `..', delete the last component. */ - else if (*i == '.' && i + 1 < end && i[1] == '.' && - (i + 2 == end || i[2] == '/')) { - if (!s.empty()) { - s.erase(s.rfind('/')); - } - i += 2; - } - - /* Normal component; copy it. */ - else { - s += '/'; - while (i != end && *i != '/') { - s += *i++; - } - - /* If s points to a symlink, resolve it and restart (since - the symlink target might contain new symlinks). */ - if (resolveSymlinks && isLink(s)) { - if (++followCount >= maxFollow) { - throw Error(format("infinite symlink recursion in path '%1%'") % - path); - } - temp = absPath(readLink(s), dirOf(s)) + std::string(i, end); - i = temp.begin(); /* restart */ - end = temp.end(); - s = ""; - } - } - } - - return s.empty() ? "/" : s; -} - -// TODO(grfn) remove in favor of std::filesystem::path::parent_path() -Path dirOf(absl::string_view path) { - Path::size_type pos = path.rfind('/'); - if (pos == std::string::npos) { - return "."; - } - return pos == 0 ? "/" : Path(path, 0, pos); -} - -// TODO(grfn) remove in favor of std::filesystem::path::root_name() -std::string baseNameOf(const Path& path) { - if (path.empty()) { - return ""; - } - - Path::size_type last = path.length() - 1; - if (path[last] == '/' && last > 0) { - last -= 1; - } - - Path::size_type pos = path.rfind('/', last); - if (pos == std::string::npos) { - pos = 0; - } else { - pos += 1; - } - - return std::string(path, pos, last - pos + 1); -} - -bool isInDir(const Path& path, const Path& dir) { - return path[0] == '/' && std::string(path, 0, dir.size()) == dir && - path.size() >= dir.size() + 2 && path[dir.size()] == '/'; -} - -bool isDirOrInDir(const Path& path, const Path& dir) { - return path == dir || isInDir(path, dir); -} - -struct stat lstat(const Path& path) { - struct stat st; - if (lstat(path.c_str(), &st) != 0) { - throw SysError(format("getting status of '%1%'") % path); - } - return st; -} - -bool pathExists(const Path& path) { - int res; - struct stat st; - res = lstat(path.c_str(), &st); - if (res == 0) { - return true; - } - if (errno != ENOENT && errno != ENOTDIR) { - throw SysError(format("getting status of %1%") % path); - } - return false; -} - -Path readLink(const Path& path) { - checkInterrupt(); - std::vector<char> buf; - for (ssize_t bufSize = PATH_MAX / 4; true; bufSize += bufSize / 2) { - buf.resize(bufSize); - ssize_t rlSize = readlink(path.c_str(), buf.data(), bufSize); - if (rlSize == -1) { - if (errno == EINVAL) { - throw Error("'%1%' is not a symlink", path); - } - throw SysError("reading symbolic link '%1%'", path); - - } else if (rlSize < bufSize) { - return std::string(buf.data(), rlSize); - } - } -} - -bool isLink(const Path& path) { - struct stat st = lstat(path); - return S_ISLNK(st.st_mode); -} - -DirEntries readDirectory(DIR* dir, const Path& path) { - DirEntries entries; - entries.reserve(64); - - struct dirent* dirent; - while (errno = 0, dirent = readdir(dir)) { /* sic */ - checkInterrupt(); - std::string name = dirent->d_name; - if (name == "." || name == "..") { - continue; - } - entries.emplace_back(name, dirent->d_ino, -#ifdef HAVE_STRUCT_DIRENT_D_TYPE - dirent->d_type -#else - DT_UNKNOWN -#endif - ); - } - if (errno) { - throw SysError(format("reading directory '%1%'") % path); - } - - return entries; -} - -DirEntries readDirectory(const Path& path) { - AutoCloseDir dir(opendir(path.c_str())); - if (!dir) { - throw SysError(format("opening directory '%1%'") % path); - } - - return readDirectory(dir.get(), path); -} - -unsigned char getFileType(const Path& path) { - struct stat st = lstat(path); - if (S_ISDIR(st.st_mode)) { - return DT_DIR; - } - if (S_ISLNK(st.st_mode)) { - return DT_LNK; - } - if (S_ISREG(st.st_mode)) { - return DT_REG; - } - return DT_UNKNOWN; -} - -std::string readFile(int fd) { - struct stat st; - if (fstat(fd, &st) == -1) { - throw SysError("statting file"); - } - - std::vector<unsigned char> buf(st.st_size); - readFull(fd, buf.data(), st.st_size); - - return std::string(reinterpret_cast<char*>(buf.data()), st.st_size); -} - -std::string readFile(absl::string_view path, bool drain) { - AutoCloseFD fd(open(std::string(path).c_str(), O_RDONLY | O_CLOEXEC)); - if (!fd) { - throw SysError(format("opening file '%1%'") % path); - } - return drain ? drainFD(fd.get()) : readFile(fd.get()); -} - -void readFile(absl::string_view path, Sink& sink) { - // TODO(tazjin): use stdlib functions for this stuff - AutoCloseFD fd(open(std::string(path).c_str(), O_RDONLY | O_CLOEXEC)); - if (!fd) { - throw SysError("opening file '%s'", path); - } - drainFD(fd.get(), sink); -} - -void writeFile(const Path& path, const std::string& s, mode_t mode) { - AutoCloseFD fd( - open(path.c_str(), O_WRONLY | O_TRUNC | O_CREAT | O_CLOEXEC, mode)); - if (!fd) { - throw SysError(format("opening file '%1%'") % path); - } - writeFull(fd.get(), s); -} - -void writeFile(const Path& path, Source& source, mode_t mode) { - AutoCloseFD fd( - open(path.c_str(), O_WRONLY | O_TRUNC | O_CREAT | O_CLOEXEC, mode)); - if (!fd) { - throw SysError(format("opening file '%1%'") % path); - } - - std::vector<unsigned char> buf(64 * 1024); - - while (true) { - try { - auto n = source.read(buf.data(), buf.size()); - writeFull(fd.get(), static_cast<unsigned char*>(buf.data()), n); - } catch (EndOfFile&) { - break; - } - } -} - -std::string readLine(int fd) { - std::string s; - while (true) { - checkInterrupt(); - char ch; - // FIXME: inefficient - ssize_t rd = read(fd, &ch, 1); - if (rd == -1) { - if (errno != EINTR) { - throw SysError("reading a line"); - } - } else if (rd == 0) { - throw EndOfFile("unexpected EOF reading a line"); - } else { - if (ch == '\n') { - return s; - } - s += ch; - } - } -} - -void writeLine(int fd, std::string s) { - s += '\n'; - writeFull(fd, s); -} - -static void _deletePath(int parentfd, const Path& path, - unsigned long long& bytesFreed) { - checkInterrupt(); - - std::string name(baseNameOf(path)); - - struct stat st; - if (fstatat(parentfd, name.c_str(), &st, AT_SYMLINK_NOFOLLOW) == -1) { - if (errno == ENOENT) { - return; - } - throw SysError(format("getting status of '%1%'") % path); - } - - if (!S_ISDIR(st.st_mode) && st.st_nlink == 1) { - bytesFreed += st.st_size; - } - - if (S_ISDIR(st.st_mode)) { - /* Make the directory accessible. */ - const auto PERM_MASK = S_IRUSR | S_IWUSR | S_IXUSR; - if ((st.st_mode & PERM_MASK) != PERM_MASK) { - if (fchmodat(parentfd, name.c_str(), st.st_mode | PERM_MASK, 0) == -1) { - throw SysError(format("chmod '%1%'") % path); - } - } - - int fd = openat(parentfd, path.c_str(), O_RDONLY); - if (!fd) { - throw SysError(format("opening directory '%1%'") % path); - } - AutoCloseDir dir(fdopendir(fd)); - if (!dir) { - throw SysError(format("opening directory '%1%'") % path); - } - for (auto& i : readDirectory(dir.get(), path)) { - _deletePath(dirfd(dir.get()), path + "/" + i.name, bytesFreed); - } - } - - int flags = S_ISDIR(st.st_mode) ? AT_REMOVEDIR : 0; - if (unlinkat(parentfd, name.c_str(), flags) == -1) { - if (errno == ENOENT) { - return; - } - throw SysError(format("cannot unlink '%1%'") % path); - } -} - -static void _deletePath(const Path& path, unsigned long long& bytesFreed) { - Path dir = dirOf(path); - if (dir == "") { - dir = "/"; - } - - AutoCloseFD dirfd(open(dir.c_str(), O_RDONLY)); - if (!dirfd) { - // This really shouldn't fail silently, but it's left this way - // for backwards compatibility. - if (errno == ENOENT) { - return; - } - - throw SysError(format("opening directory '%1%'") % path); - } - - _deletePath(dirfd.get(), path, bytesFreed); -} - -void deletePath(const Path& path) { - unsigned long long dummy; - deletePath(path, dummy); -} - -void deletePath(const Path& path, unsigned long long& bytesFreed) { - // Activity act(*logger, lvlDebug, format("recursively deleting path '%1%'") % - // path); - bytesFreed = 0; - _deletePath(path, bytesFreed); -} - -static Path tempName(Path tmpRoot, const Path& prefix, bool includePid, - int& counter) { - tmpRoot = canonPath( - tmpRoot.empty() ? getEnv("TMPDIR").value_or("/tmp") : tmpRoot, true); - - if (includePid) { - return (format("%1%/%2%-%3%-%4%") % tmpRoot % prefix % getpid() % counter++) - .str(); - } - return (format("%1%/%2%-%3%") % tmpRoot % prefix % counter++).str(); -} - -Path createTempDir(const Path& tmpRoot, const Path& prefix, bool includePid, - bool useGlobalCounter, mode_t mode) { - static int globalCounter = 0; - int localCounter = 0; - int& counter(useGlobalCounter ? globalCounter : localCounter); - - while (true) { - checkInterrupt(); - Path tmpDir = tempName(tmpRoot, prefix, includePid, counter); - if (mkdir(tmpDir.c_str(), mode) == 0) { -#if __FreeBSD__ - /* Explicitly set the group of the directory. This is to - work around around problems caused by BSD's group - ownership semantics (directories inherit the group of - the parent). For instance, the group of /tmp on - FreeBSD is "wheel", so all directories created in /tmp - will be owned by "wheel"; but if the user is not in - "wheel", then "tar" will fail to unpack archives that - have the setgid bit set on directories. */ - if (chown(tmpDir.c_str(), (uid_t)-1, getegid()) != 0) - throw SysError(format("setting group of directory '%1%'") % tmpDir); -#endif - return tmpDir; - } - if (errno != EEXIST) { - throw SysError(format("creating directory '%1%'") % tmpDir); - } - } -} - -std::string getUserName() { - auto pw = getpwuid(geteuid()); - std::optional<std::string> name = - pw != nullptr ? pw->pw_name : getEnv("USER"); - if (!name.has_value()) { - throw Error("cannot figure out user name"); - } - return *name; -} - -static Lazy<Path> getHome2([]() { - std::optional<Path> homeDir = getEnv("HOME"); - if (!homeDir) { - std::vector<char> buf(16384); - struct passwd pwbuf; - struct passwd* pw; - if (getpwuid_r(geteuid(), &pwbuf, buf.data(), buf.size(), &pw) != 0 || - (pw == nullptr) || (pw->pw_dir == nullptr) || (pw->pw_dir[0] == 0)) { - throw Error("cannot determine user's home directory"); - } - return std::string(pw->pw_dir); - } - return homeDir.value(); -}); - -Path getHome() { return getHome2(); } - -Path getCacheDir() { - return getEnv("XDG_CACHE_HOME").value_or(getHome() + "/.cache"); -} - -Path getConfigDir() { - return getEnv("XDG_CONFIG_HOME").value_or(getHome() + "/.config"); -} - -std::vector<Path> getConfigDirs() { - Path configHome = getConfigDir(); - std::string configDirs = getEnv("XDG_CONFIG_DIRS").value_or(""); - std::vector<std::string> result = - absl::StrSplit(configDirs, absl::ByChar(':'), absl::SkipEmpty()); - result.insert(result.begin(), configHome); - return result; -} - -Path getDataDir() { - return getEnv("XDG_DATA_HOME").value_or(getHome() + "/.local/share"); -} - -// TODO(grfn): Remove in favor of std::filesystem::create_directories -Paths createDirs(const Path& path) { - Paths created; - if (path == "/") { - return created; - } - - struct stat st; - if (lstat(path.c_str(), &st) == -1) { - created = createDirs(dirOf(path)); - if (mkdir(path.c_str(), 0777) == -1 && errno != EEXIST) { - throw SysError(format("creating directory '%1%'") % path); - } - st = lstat(path); - created.push_back(path); - } - - if (S_ISLNK(st.st_mode) && stat(path.c_str(), &st) == -1) { - throw SysError(format("statting symlink '%1%'") % path); - } - - if (!S_ISDIR(st.st_mode)) { - throw Error(format("'%1%' is not a directory") % path); - } - - return created; -} - -void createSymlink(const Path& target, const Path& link) { - if (symlink(target.c_str(), link.c_str()) != 0) { - throw SysError(format("creating symlink from '%1%' to '%2%'") % link % - target); - } -} - -void replaceSymlink(const Path& target, const Path& link) { - for (unsigned int n = 0; true; n++) { - Path tmp = canonPath(fmt("%s/.%d_%s", dirOf(link), n, baseNameOf(link))); - - try { - createSymlink(target, tmp); - } catch (SysError& e) { - if (e.errNo == EEXIST) { - continue; - } - throw; - } - - if (rename(tmp.c_str(), link.c_str()) != 0) { - throw SysError(format("renaming '%1%' to '%2%'") % tmp % link); - } - - break; - } -} - -void readFull(int fd, unsigned char* buf, size_t count) { - while (count != 0u) { - checkInterrupt(); - ssize_t res = read(fd, reinterpret_cast<char*>(buf), count); - if (res == -1) { - if (errno == EINTR) { - continue; - } - throw SysError("reading from file"); - } - if (res == 0) { - throw EndOfFile("unexpected end-of-file"); - } - count -= res; - buf += res; - } -} - -void writeFull(int fd, const unsigned char* buf, size_t count, - bool allowInterrupts) { - while (count != 0u) { - if (allowInterrupts) { - checkInterrupt(); - } - ssize_t res = write(fd, (char*)buf, count); - if (res == -1 && errno != EINTR) { - throw SysError("writing to file"); - } - if (res > 0) { - count -= res; - buf += res; - } - } -} - -void writeFull(int fd, const std::string& s, bool allowInterrupts) { - writeFull(fd, reinterpret_cast<const unsigned char*>(s.data()), s.size(), - allowInterrupts); -} - -std::string drainFD(int fd, bool block) { - StringSink sink; - drainFD(fd, sink, block); - return std::move(*sink.s); -} - -void drainFD(int fd, Sink& sink, bool block) { - int saved; - - Finally finally([&]() { - if (!block) { - if (fcntl(fd, F_SETFL, saved) == -1) { - throw SysError("making file descriptor blocking"); - } - } - }); - - if (!block) { - saved = fcntl(fd, F_GETFL); - if (fcntl(fd, F_SETFL, saved | O_NONBLOCK) == -1) { - throw SysError("making file descriptor non-blocking"); - } - } - - std::vector<unsigned char> buf(64 * 1024); - while (true) { - checkInterrupt(); - ssize_t rd = read(fd, buf.data(), buf.size()); - if (rd == -1) { - if (!block && (errno == EAGAIN || errno == EWOULDBLOCK)) { - break; - } - if (errno != EINTR) { - throw SysError("reading from file"); - } - } else if (rd == 0) { - break; - } else { - sink(buf.data(), rd); - } - } -} - -////////////////////////////////////////////////////////////////////// - -AutoDelete::AutoDelete() : del{false} {} - -AutoDelete::AutoDelete(std::string p, bool recursive) : path(std::move(p)) { - del = true; - this->recursive = recursive; -} - -AutoDelete::~AutoDelete() { - try { - if (del) { - if (recursive) { - deletePath(path); - } else { - if (remove(path.c_str()) == -1) { - throw SysError(format("cannot unlink '%1%'") % path); - } - } - } - } catch (...) { - ignoreException(); - } -} - -void AutoDelete::cancel() { del = false; } - -void AutoDelete::reset(const Path& p, bool recursive) { - path = p; - this->recursive = recursive; - del = true; -} - -////////////////////////////////////////////////////////////////////// - -AutoCloseFD::AutoCloseFD() : fd{-1} {} - -AutoCloseFD::AutoCloseFD(int fd) : fd{fd} {} - -AutoCloseFD::AutoCloseFD(AutoCloseFD&& that) : fd{that.fd} { that.fd = -1; } - -AutoCloseFD& AutoCloseFD::operator=(AutoCloseFD&& that) { - close(); - fd = that.fd; - that.fd = -1; - return *this; -} - -AutoCloseFD::~AutoCloseFD() { - try { - close(); - } catch (...) { - ignoreException(); - } -} - -int AutoCloseFD::get() const { return fd; } - -void AutoCloseFD::close() { - if (fd != -1) { - if (::close(fd) == -1) { /* This should never happen. */ - throw SysError(format("closing file descriptor %1%") % fd); - } - } -} - -AutoCloseFD::operator bool() const { return fd != -1; } - -int AutoCloseFD::release() { - int oldFD = fd; - fd = -1; - return oldFD; -} - -void Pipe::create() { - int fds[2]; -#if HAVE_PIPE2 - if (pipe2(fds, O_CLOEXEC) != 0) { - throw SysError("creating pipe"); - } -#else - if (pipe(fds) != 0) { - throw SysError("creating pipe"); - } - closeOnExec(fds[0]); - closeOnExec(fds[1]); -#endif - readSide = AutoCloseFD(fds[0]); - writeSide = AutoCloseFD(fds[1]); -} - -////////////////////////////////////////////////////////////////////// - -Pid::Pid() = default; - -Pid::Pid(pid_t pid) : pid(pid) {} - -Pid::~Pid() { - if (pid != -1) { - kill(); - } -} - -void Pid::operator=(pid_t pid) { - if (this->pid != -1 && this->pid != pid) { - kill(); - } - this->pid = pid; - killSignal = SIGKILL; // reset signal to default -} - -Pid::operator pid_t() { return pid; } - -int Pid::kill() { - assert(pid != -1); - - DLOG(INFO) << "killing process " << pid; - - /* Send the requested signal to the child. If it has its own - process group, send the signal to every process in the child - process group (which hopefully includes *all* its children). */ - if (::kill(separatePG ? -pid : pid, killSignal) != 0) { - LOG(ERROR) << SysError("killing process %d", pid).msg(); - } - - return wait(); -} - -int Pid::wait() { - assert(pid != -1); - while (true) { - int status; - int res = waitpid(pid, &status, 0); - if (res == pid) { - pid = -1; - return status; - } - if (errno != EINTR) { - throw SysError("cannot get child exit status"); - } - checkInterrupt(); - } -} - -void Pid::setSeparatePG(bool separatePG) { this->separatePG = separatePG; } - -void Pid::setKillSignal(int signal) { this->killSignal = signal; } - -pid_t Pid::release() { - pid_t p = pid; - pid = -1; - return p; -} - -void killUser(uid_t uid) { - DLOG(INFO) << "killing all processes running under UID " << uid; - - assert(uid != 0); /* just to be safe... */ - - /* The system call kill(-1, sig) sends the signal `sig' to all - users to which the current process can send signals. So we - fork a process, switch to uid, and send a mass kill. */ - - ProcessOptions options; - - Pid pid(startProcess( - [&]() { - if (setuid(uid) == -1) { - throw SysError("setting uid"); - } - - while (true) { - if (kill(-1, SIGKILL) == 0) { - break; - } - if (errno == ESRCH) { - break; - } /* no more processes */ - if (errno != EINTR) { - throw SysError(format("cannot kill processes for uid '%1%'") % uid); - } - } - - _exit(0); - }, - options)); - - int status = pid.wait(); - if (status != 0) { - throw Error(format("cannot kill processes for uid '%1%': %2%") % uid % - statusToString(status)); - } - - /* !!! We should really do some check to make sure that there are - no processes left running under `uid', but there is no portable - way to do so (I think). The most reliable way may be `ps -eo - uid | grep -q $uid'. */ -} - -////////////////////////////////////////////////////////////////////// - -/* - * Please note that it is not legal for this function to call vfork(). If the - * process created by vfork() returns from the function in which vfork() was - * called, or calls any other function before successfully calling _exit() or - * one of the exec*() family of functions, the behavior is undefined. - */ -static pid_t doFork(const std::function<void()>& fun) __attribute__((noinline)); -static pid_t doFork(const std::function<void()>& fun) { -#ifdef __linux__ - // TODO(kanepyork): call clone() instead for faster forking -#endif - - pid_t pid = fork(); - if (pid != 0) { - return pid; - } - fun(); - abort(); -} - -pid_t startProcess(std::function<void()> fun, const ProcessOptions& options) { - auto wrapper = [&]() { - try { -#if __linux__ - if (options.dieWithParent && prctl(PR_SET_PDEATHSIG, SIGKILL) == -1) { - throw SysError("setting death signal"); - } -#endif - restoreAffinity(); - fun(); - } catch (std::exception& e) { - try { - LOG(ERROR) << options.errorPrefix << e.what(); - } catch (...) { - } - } catch (...) { - } - if (options.runExitHandlers) { - exit(1); - } else { - _exit(1); - } - }; - - pid_t pid = doFork(wrapper); - if (pid == -1) { - throw SysError("unable to fork"); - } - - return pid; -} - -std::vector<char*> stringsToCharPtrs(const Strings& ss) { - std::vector<char*> res; - for (auto& s : ss) { - res.push_back(const_cast<char*>(s.c_str())); - } - res.push_back(nullptr); - return res; -} - -std::string runProgram(const Path& program, bool searchPath, - const Strings& args, - const std::optional<std::string>& input) { - RunOptions opts(program, args); - opts.searchPath = searchPath; - opts.input = input; - - auto res = runProgram(opts); - - if (!statusOk(res.first)) { - throw ExecError(res.first, fmt("program '%1%' %2%", program, - statusToString(res.first))); - } - - return res.second; -} - -std::pair<int, std::string> runProgram(const RunOptions& options_) { - RunOptions options(options_); - StringSink sink; - options.standardOut = &sink; - - int status = 0; - - try { - runProgram2(options); - } catch (ExecError& e) { - status = e.status; - } - - return {status, std::move(*sink.s)}; -} - -void runProgram2(const RunOptions& options) { - checkInterrupt(); - - assert(!(options.standardIn && options.input)); - - std::unique_ptr<Source> source_; - Source* source = options.standardIn; - - if (options.input) { - source_ = std::make_unique<StringSource>(*options.input); - source = source_.get(); - } - - /* Create a pipe. */ - Pipe out; - Pipe in; - if (options.standardOut != nullptr) { - out.create(); - } - if (source != nullptr) { - in.create(); - } - - ProcessOptions processOptions; - - /* Fork. */ - Pid pid(startProcess( - [&]() { - if (options.environment) { - replaceEnv(*options.environment); - } - if ((options.standardOut != nullptr) && - dup2(out.writeSide.get(), STDOUT_FILENO) == -1) { - throw SysError("dupping stdout"); - } - if (options.mergeStderrToStdout) { - if (dup2(STDOUT_FILENO, STDERR_FILENO) == -1) { - throw SysError("cannot dup stdout into stderr"); - } - } - if ((source != nullptr) && - dup2(in.readSide.get(), STDIN_FILENO) == -1) { - throw SysError("dupping stdin"); - } - - if (options.chdir && chdir((*options.chdir).c_str()) == -1) { - throw SysError("chdir failed"); - } - if (options.gid && setgid(*options.gid) == -1) { - throw SysError("setgid failed"); - } - /* Drop all other groups if we're setgid. */ - if (options.gid && setgroups(0, nullptr) == -1) { - throw SysError("setgroups failed"); - } - if (options.uid && setuid(*options.uid) == -1) { - throw SysError("setuid failed"); - } - - Strings args_(options.args); - args_.push_front(options.program); - - restoreSignals(); - - if (options.searchPath) { - execvp(options.program.c_str(), stringsToCharPtrs(args_).data()); - } else { - execv(options.program.c_str(), stringsToCharPtrs(args_).data()); - } - - throw SysError("executing '%1%'", options.program); - }, - processOptions)); - - out.writeSide = AutoCloseFD(-1); - - std::thread writerThread; - - std::promise<void> promise; - - Finally doJoin([&]() { - if (writerThread.joinable()) { - writerThread.join(); - } - }); - - if (source != nullptr) { - in.readSide = AutoCloseFD(-1); - writerThread = std::thread([&]() { - try { - std::vector<unsigned char> buf(8 * 1024); - while (true) { - size_t n; - try { - n = source->read(buf.data(), buf.size()); - } catch (EndOfFile&) { - break; - } - writeFull(in.writeSide.get(), buf.data(), n); - } - promise.set_value(); - } catch (...) { - promise.set_exception(std::current_exception()); - } - in.writeSide = AutoCloseFD(-1); - }); - } - - if (options.standardOut != nullptr) { - drainFD(out.readSide.get(), *options.standardOut); - } - - /* Wait for the child to finish. */ - int status = pid.wait(); - - /* Wait for the writer thread to finish. */ - if (source != nullptr) { - promise.get_future().get(); - } - - if (status != 0) { - throw ExecError(status, fmt("program '%1%' %2%", options.program, - statusToString(status))); - } -} - -void closeMostFDs(const std::set<int>& exceptions) { -#if __linux__ - try { - for (auto& s : readDirectory("/proc/self/fd")) { - auto fd = std::stoi(s.name); - if (exceptions.count(fd) == 0u) { - DLOG(INFO) << "closing leaked FD " << fd; - close(fd); - } - } - return; - } catch (SysError&) { - } -#endif - - int maxFD = 0; - maxFD = sysconf(_SC_OPEN_MAX); - for (int fd = 0; fd < maxFD; ++fd) { - if (exceptions.count(fd) == 0u) { - close(fd); - } /* ignore result */ - } -} - -void closeOnExec(int fd) { - int prev; - if ((prev = fcntl(fd, F_GETFD, 0)) == -1 || - fcntl(fd, F_SETFD, prev | FD_CLOEXEC) == -1) { - throw SysError("setting close-on-exec flag"); - } -} - -////////////////////////////////////////////////////////////////////// - -bool _isInterrupted = false; - -static thread_local bool interruptThrown = false; -thread_local std::function<bool()> interruptCheck; - -void setInterruptThrown() { interruptThrown = true; } - -void _interrupted() { - /* Block user interrupts while an exception is being handled. - Throwing an exception while another exception is being handled - kills the program! */ - if (!interruptThrown && (std::uncaught_exceptions() == 0)) { - interruptThrown = true; - throw Interrupted("interrupted by the user"); - } -} - -////////////////////////////////////////////////////////////////////// - -std::string concatStringsSep(const std::string& sep, const Strings& ss) { - std::string s; - for (auto& i : ss) { - if (!s.empty()) { - s += sep; - } - s += i; - } - return s; -} - -std::string concatStringsSep(const std::string& sep, const StringSet& ss) { - std::string s; - for (auto& i : ss) { - if (!s.empty()) { - s += sep; - } - s += i; - } - return s; -} - -std::string replaceStrings(const std::string& s, const std::string& from, - const std::string& to) { - if (from.empty()) { - return s; - } - std::string res = s; - size_t pos = 0; - while ((pos = res.find(from, pos)) != std::string::npos) { - res.replace(pos, from.size(), to); - pos += to.size(); - } - return res; -} - -std::string statusToString(int status) { - if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { - if (WIFEXITED(status)) { - return (format("failed with exit code %1%") % WEXITSTATUS(status)).str(); - } - if (WIFSIGNALED(status)) { - int sig = WTERMSIG(status); -#if HAVE_STRSIGNAL - const char* description = strsignal(sig); - return (format("failed due to signal %1% (%2%)") % sig % description) - .str(); -#else - return (format("failed due to signal %1%") % sig).str(); -#endif - } else { - return "died abnormally"; - } - } else { - return "succeeded"; - } -} - -bool statusOk(int status) { - return WIFEXITED(status) && WEXITSTATUS(status) == 0; -} - -std::string toLower(const std::string& s) { - std::string r(s); - for (auto& c : r) { - c = std::tolower(c); - } - return r; -} - -std::string shellEscape(const std::string& s) { - std::string r = "'"; - for (auto& i : s) { - if (i == '\'') { - r += "'\\''"; - } else { - r += i; - } - } - r += '\''; - return r; -} - -void ignoreException() { - try { - throw; - } catch (std::exception& e) { - LOG(ERROR) << "error (ignored): " << e.what(); - } -} - -std::string filterANSIEscapes(const std::string& s, bool filterAll, - unsigned int width) { - std::string t; - std::string e; - size_t w = 0; - auto i = s.begin(); - - while (w < static_cast<size_t>(width) && i != s.end()) { - if (*i == '\e') { - std::string e; - e += *i++; - char last = 0; - - if (i != s.end() && *i == '[') { - e += *i++; - // eat parameter bytes - while (i != s.end() && *i >= 0x30 && *i <= 0x3f) { - e += *i++; - } - // eat intermediate bytes - while (i != s.end() && *i >= 0x20 && *i <= 0x2f) { - e += *i++; - } - // eat final byte - if (i != s.end() && *i >= 0x40 && *i <= 0x7e) { - e += last = *i++; - } - } else { - if (i != s.end() && *i >= 0x40 && *i <= 0x5f) { - e += *i++; - } - } - - if (!filterAll && last == 'm') { - t += e; - } - } - - else if (*i == '\t') { - i++; - t += ' '; - w++; - while (w < static_cast<size_t>(width) && ((w % 8) != 0u)) { - t += ' '; - w++; - } - } - - else if (*i == '\r') { - // do nothing for now - i++; - - } else { - t += *i++; - w++; - } - } - - return t; -} - -void callFailure(const std::function<void(std::exception_ptr exc)>& failure, - const std::exception_ptr& exc) { - try { - failure(exc); - } catch (std::exception& e) { - LOG(ERROR) << "uncaught exception: " << e.what(); - abort(); - } -} - -static Sync<std::pair<unsigned short, unsigned short>> windowSize{{0, 0}}; - -static void updateWindowSize() { - struct winsize ws; - if (ioctl(2, TIOCGWINSZ, &ws) == 0) { - auto windowSize_(windowSize.lock()); - windowSize_->first = ws.ws_row; - windowSize_->second = ws.ws_col; - } -} - -std::pair<unsigned short, unsigned short> getWindowSize() { - return *windowSize.lock(); -} - -static Sync<std::list<std::function<void()>>> _interruptCallbacks; - -static void signalHandlerThread(sigset_t set) { - while (true) { - int signal = 0; - sigwait(&set, &signal); - - if (signal == SIGINT || signal == SIGTERM || signal == SIGHUP) { - triggerInterrupt(); - - } else if (signal == SIGWINCH) { - updateWindowSize(); - } - } -} - -void triggerInterrupt() { - _isInterrupted = true; - - { - auto interruptCallbacks(_interruptCallbacks.lock()); - for (auto& callback : *interruptCallbacks) { - try { - callback(); - } catch (...) { - ignoreException(); - } - } - } -} - -static sigset_t savedSignalMask; - -void startSignalHandlerThread() { - updateWindowSize(); - - if (sigprocmask(SIG_BLOCK, nullptr, &savedSignalMask) != 0) { - throw SysError("quering signal mask"); - } - - sigset_t set; - sigemptyset(&set); - sigaddset(&set, SIGINT); - sigaddset(&set, SIGTERM); - sigaddset(&set, SIGHUP); - sigaddset(&set, SIGPIPE); - sigaddset(&set, SIGWINCH); - if (pthread_sigmask(SIG_BLOCK, &set, nullptr) != 0) { - throw SysError("blocking signals"); - } - - std::thread(signalHandlerThread, set).detach(); -} - -void restoreSignals() { - if (sigprocmask(SIG_SETMASK, &savedSignalMask, nullptr) != 0) { - throw SysError("restoring signals"); - } -} - -/* RAII helper to automatically deregister a callback. */ -struct InterruptCallbackImpl : InterruptCallback { - std::list<std::function<void()>>::iterator it; - ~InterruptCallbackImpl() override { _interruptCallbacks.lock()->erase(it); } -}; - -std::unique_ptr<InterruptCallback> createInterruptCallback( - const std::function<void()>& callback) { - auto interruptCallbacks(_interruptCallbacks.lock()); - interruptCallbacks->push_back(callback); - - auto res = std::make_unique<InterruptCallbackImpl>(); - res->it = interruptCallbacks->end(); - res->it--; - - return std::unique_ptr<InterruptCallback>(res.release()); -} - -} // namespace nix |