| /*-*- 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 <stdbool.h> |
| #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" |
| |
| static void backspace_chars(int ttyfd, size_t p) { |
| |
| if (ttyfd < 0) |
| return; |
| |
| while (p > 0) { |
| p--; |
| |
| loop_write(ttyfd, "\b \b", 3, false); |
| } |
| } |
| |
| 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; |
| bool silent_mode = false; |
| bool dirty = 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) { /* C-u */ |
| |
| if (!silent_mode) |
| backspace_chars(ttyfd, p); |
| p = 0; |
| |
| } else if (c == '\b' || c == 127) { |
| |
| if (p > 0) { |
| |
| if (!silent_mode) |
| backspace_chars(ttyfd, 1); |
| |
| p--; |
| } else if (!dirty && !silent_mode) { |
| |
| silent_mode = true; |
| |
| /* There are two ways to enter silent |
| * mode. Either by pressing backspace |
| * as first key (and only as first key), |
| * or ... */ |
| if (ttyfd >= 0) |
| loop_write(ttyfd, "(no echo) ", 10, false); |
| |
| } else if (ttyfd >= 0) |
| loop_write(ttyfd, "\a", 1, false); |
| |
| } else if (c == '\t' && !silent_mode) { |
| |
| backspace_chars(ttyfd, p); |
| silent_mode = true; |
| |
| /* ... or by pressing TAB at any time. */ |
| |
| if (ttyfd >= 0) |
| loop_write(ttyfd, "(no echo) ", 10, false); |
| } else { |
| passphrase[p++] = c; |
| |
| if (!silent_mode && ttyfd >= 0) |
| loop_write(ttyfd, "*", 1, false); |
| |
| dirty = true; |
| } |
| } |
| |
| 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, "/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[] = "/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("/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); |
| } |