/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. Copyright 2010 Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include <termios.h> #include <unistd.h> #include <sys/poll.h> #include <sys/inotify.h> #include <errno.h> #include <fcntl.h> #include <sys/socket.h> #include <string.h> #include <sys/un.h> #include <stddef.h> #include <sys/signalfd.h> #include "util.h" #include "strv.h" #include "ask-password-api.h" int ask_password_tty( const char *message, usec_t until, const char *flag_file, char **_passphrase) { struct termios old_termios, new_termios; char passphrase[LINE_MAX]; size_t p = 0; int r, ttyfd = -1, notify = -1; struct pollfd pollfd[2]; bool reset_tty = false; enum { POLL_TTY, POLL_INOTIFY }; assert(message); assert(_passphrase); if (flag_file) { if ((notify = inotify_init1(IN_CLOEXEC|IN_NONBLOCK)) < 0) { r = -errno; goto finish; } if (inotify_add_watch(notify, flag_file, IN_ATTRIB /* for the link count */) < 0) { r = -errno; goto finish; } } if ((ttyfd = open("/dev/tty", O_RDWR|O_NOCTTY|O_CLOEXEC)) >= 0) { if (tcgetattr(ttyfd, &old_termios) < 0) { r = -errno; goto finish; } loop_write(ttyfd, "\x1B[1m", 4, false); loop_write(ttyfd, message, strlen(message), false); loop_write(ttyfd, " ", 1, false); loop_write(ttyfd, "\x1B[0m", 4, false); new_termios = old_termios; new_termios.c_lflag &= ~(ICANON|ECHO); new_termios.c_cc[VMIN] = 1; new_termios.c_cc[VTIME] = 0; if (tcsetattr(ttyfd, TCSADRAIN, &new_termios) < 0) { r = -errno; goto finish; } reset_tty = true; } zero(pollfd); pollfd[POLL_TTY].fd = ttyfd >= 0 ? ttyfd : STDIN_FILENO; pollfd[POLL_TTY].events = POLLIN; pollfd[POLL_INOTIFY].fd = notify; pollfd[POLL_INOTIFY].events = POLLIN; for (;;) { char c; int sleep_for = -1, k; ssize_t n; if (until > 0) { usec_t y; y = now(CLOCK_MONOTONIC); if (y > until) { r = -ETIME; goto finish; } sleep_for = (int) ((until - y) / USEC_PER_MSEC); } if (flag_file) if (access(flag_file, F_OK) < 0) { r = -errno; goto finish; } if ((k = poll(pollfd, notify > 0 ? 2 : 1, sleep_for)) < 0) { if (errno == EINTR) continue; r = -errno; goto finish; } else if (k == 0) { r = -ETIME; goto finish; } if (notify > 0 && pollfd[POLL_INOTIFY].revents != 0) flush_fd(notify); if (pollfd[POLL_TTY].revents == 0) continue; if ((n = read(ttyfd >= 0 ? ttyfd : STDIN_FILENO, &c, 1)) < 0) { if (errno == EINTR || errno == EAGAIN) continue; r = -errno; goto finish; } else if (n == 0) break; if (c == '\n') break; else if (c == 21) { while (p > 0) { p--; if (ttyfd >= 0) loop_write(ttyfd, "\b \b", 3, false); } } else if (c == '\b' || c == 127) { if (p > 0) { p--; if (ttyfd >= 0) loop_write(ttyfd, "\b \b", 3, false); } } else { passphrase[p++] = c; if (ttyfd >= 0) loop_write(ttyfd, "*", 1, false); } } passphrase[p] = 0; if (!(*_passphrase = strdup(passphrase))) { r = -ENOMEM; goto finish; } r = 0; finish: if (notify >= 0) close_nointr_nofail(notify); if (ttyfd >= 0) { if (reset_tty) { loop_write(ttyfd, "\n", 1, false); tcsetattr(ttyfd, TCSADRAIN, &old_termios); } close_nointr_nofail(ttyfd); } return r; } static int create_socket(char **name) { int fd; union { struct sockaddr sa; struct sockaddr_un un; } sa; int one = 1, r; char *c; assert(name); if ((fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0)) < 0) { log_error("socket() failed: %m"); return -errno; } zero(sa); sa.un.sun_family = AF_UNIX; snprintf(sa.un.sun_path, sizeof(sa.un.sun_path)-1, "/dev/.run/systemd/ask-password/sck.%llu", random_ull()); if (bind(fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(sa.un.sun_path)) < 0) { r = -errno; log_error("bind() failed: %m"); goto fail; } if (setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one)) < 0) { r = -errno; log_error("SO_PASSCRED failed: %m"); goto fail; } if (!(c = strdup(sa.un.sun_path))) { r = -ENOMEM; log_error("Out of memory"); goto fail; } *name = c; return fd; fail: close_nointr_nofail(fd); return r; } int ask_password_agent( const char *message, const char *icon, usec_t until, bool accept_cached, char ***_passphrases) { enum { FD_SOCKET, FD_SIGNAL, _FD_MAX }; char temp[] = "/dev/.run/systemd/ask-password/tmp.XXXXXX"; char final[sizeof(temp)] = ""; int fd = -1, r; FILE *f = NULL; char *socket_name = NULL; int socket_fd = -1, signal_fd = -1; sigset_t mask, oldmask; struct pollfd pollfd[_FD_MAX]; assert(_passphrases); assert_se(sigemptyset(&mask) == 0); sigset_add_many(&mask, SIGINT, SIGTERM, -1); assert_se(sigprocmask(SIG_BLOCK, &mask, &oldmask) == 0); mkdir_p("/dev/.run/systemd/ask-password", 0755); if ((fd = mkostemp(temp, O_CLOEXEC|O_CREAT|O_WRONLY)) < 0) { log_error("Failed to create password file: %m"); r = -errno; goto finish; } fchmod(fd, 0644); if (!(f = fdopen(fd, "w"))) { log_error("Failed to allocate FILE: %m"); r = -errno; goto finish; } fd = -1; if ((signal_fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0) { log_error("signalfd(): %m"); r = -errno; goto finish; } if ((socket_fd = create_socket(&socket_name)) < 0) { r = socket_fd; goto finish; } fprintf(f, "[Ask]\n" "PID=%lu\n" "Socket=%s\n" "AcceptCached=%i\n" "NotAfter=%llu\n", (unsigned long) getpid(), socket_name, accept_cached ? 1 : 0, (unsigned long long) until); if (message) fprintf(f, "Message=%s\n", message); if (icon) fprintf(f, "Icon=%s\n", icon); fflush(f); if (ferror(f)) { log_error("Failed to write query file: %m"); r = -errno; goto finish; } memcpy(final, temp, sizeof(temp)); final[sizeof(final)-11] = 'a'; final[sizeof(final)-10] = 's'; final[sizeof(final)-9] = 'k'; if (rename(temp, final) < 0) { log_error("Failed to rename query file: %m"); r = -errno; goto finish; } zero(pollfd); pollfd[FD_SOCKET].fd = socket_fd; pollfd[FD_SOCKET].events = POLLIN; pollfd[FD_SIGNAL].fd = signal_fd; pollfd[FD_SIGNAL].events = POLLIN; for (;;) { char passphrase[LINE_MAX+1]; struct msghdr msghdr; struct iovec iovec; struct ucred *ucred; union { struct cmsghdr cmsghdr; uint8_t buf[CMSG_SPACE(sizeof(struct ucred))]; } control; ssize_t n; int k; usec_t t; t = now(CLOCK_MONOTONIC); if (until <= t) { log_notice("Timed out"); r = -ETIME; goto finish; } if ((k = poll(pollfd, _FD_MAX, (until-t)/USEC_PER_MSEC)) < 0) { if (errno == EINTR) continue; log_error("poll() failed: %m"); r = -errno; goto finish; } if (k <= 0) { log_notice("Timed out"); r = -ETIME; goto finish; } if (pollfd[FD_SIGNAL].revents & POLLIN) { r = -EINTR; goto finish; } if (pollfd[FD_SOCKET].revents != POLLIN) { log_error("Unexpected poll() event."); r = -EIO; goto finish; } zero(iovec); iovec.iov_base = passphrase; iovec.iov_len = sizeof(passphrase); zero(control); zero(msghdr); msghdr.msg_iov = &iovec; msghdr.msg_iovlen = 1; msghdr.msg_control = &control; msghdr.msg_controllen = sizeof(control); if ((n = recvmsg(socket_fd, &msghdr, 0)) < 0) { if (errno == EAGAIN || errno == EINTR) continue; log_error("recvmsg() failed: %m"); r = -errno; goto finish; } if (n <= 0) { log_error("Message too short"); continue; } if (msghdr.msg_controllen < CMSG_LEN(sizeof(struct ucred)) || control.cmsghdr.cmsg_level != SOL_SOCKET || control.cmsghdr.cmsg_type != SCM_CREDENTIALS || control.cmsghdr.cmsg_len != CMSG_LEN(sizeof(struct ucred))) { log_warning("Received message without credentials. Ignoring."); continue; } ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr); if (ucred->uid != 0) { log_warning("Got request from unprivileged user. Ignoring."); continue; } if (passphrase[0] == '+') { char **l; if (!(l = strv_parse_nulstr(passphrase+1, n-1))) { r = -ENOMEM; goto finish; } if (strv_length(l) <= 0) { strv_free(l); log_error("Invalid packet"); continue; } *_passphrases = l; } else if (passphrase[0] == '-') { r = -ECANCELED; goto finish; } else { log_error("Invalid packet"); continue; } break; } r = 0; finish: if (fd >= 0) close_nointr_nofail(fd); if (socket_name) { unlink(socket_name); free(socket_name); } if (socket_fd >= 0) close_nointr_nofail(socket_fd); if (signal_fd >= 0) close_nointr_nofail(signal_fd); if (f) fclose(f); unlink(temp); if (final[0]) unlink(final); assert_se(sigprocmask(SIG_SETMASK, &oldmask, NULL) == 0); return r; } int ask_password_auto(const char *message, const char *icon, usec_t until, bool accept_cached, char ***_passphrases) { assert(message); assert(_passphrases); if (isatty(STDIN_FILENO)) { int r; char *s = NULL, **l = NULL; if ((r = ask_password_tty(message, until, NULL, &s)) < 0) return r; l = strv_new(s, NULL); free(s); if (!l) return -ENOMEM; *_passphrases = l; return r; } else return ask_password_agent(message, icon, until, accept_cached, _passphrases); }