/*-*- 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 <sys/socket.h> #include <sys/poll.h> #include <sys/types.h> #include <assert.h> #include <string.h> #include <errno.h> #include <unistd.h> #include <fcntl.h> #include <sys/un.h> #include <sys/stat.h> #include <sys/signalfd.h> #include <getopt.h> #include <termios.h> #include <limits.h> #include "log.h" #include "macro.h" #include "util.h" static const char *arg_icon = NULL; static const char *arg_message = NULL; static bool arg_use_tty = true; static usec_t arg_timeout = 60 * USEC_PER_SEC; 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+1, sizeof(sa.un.sun_path)-1, "/org/freedesktop/systemd1/ask-password/%llu", random_ull()); if (bind(fd, &sa.sa, sizeof(sa_family_t) + 1 + strlen(sa.un.sun_path+1)) < 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+1))) { r = -ENOMEM; log_error("Out of memory"); goto fail; } *name = c; return fd; fail: close_nointr_nofail(fd); return r; } static int help(void) { printf("%s [OPTIONS...] MESSAGE\n\n" "Query the user for a system passphrase, via the TTY or an UI agent.\n\n" " -h --help Show this help\n" " --icon=NAME Icon name\n" " --timeout=USEC Timeout in usec\n" " --no-tty Ask question via agent even on TTY\n", program_invocation_short_name); return 0; } static int parse_argv(int argc, char *argv[]) { enum { ARG_ICON = 0x100, ARG_TIMEOUT, ARG_NO_TTY }; static const struct option options[] = { { "help", no_argument, NULL, 'h' }, { "icon", required_argument, NULL, ARG_ICON }, { "timeout", required_argument, NULL, ARG_TIMEOUT }, { "no-tty", no_argument, NULL, ARG_NO_TTY }, { NULL, 0, NULL, 0 } }; int c; assert(argc >= 0); assert(argv); while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) { switch (c) { case 'h': help(); return 0; case ARG_ICON: arg_icon = optarg; break; case ARG_TIMEOUT: if (parse_usec(optarg, &arg_timeout) < 0 || arg_timeout <= 0) { log_error("Failed to parse --timeout parameter %s", optarg); return -EINVAL; } break; case ARG_NO_TTY: arg_use_tty = false; break; case '?': return -EINVAL; default: log_error("Unknown option code %c", c); return -EINVAL; } } if (optind != argc-1) { help(); return -EINVAL; } arg_message = argv[optind]; return 1; } static int ask_agent(void) { char temp[] = "/dev/.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; sigset_t mask; usec_t not_after; 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; assert_se(sigemptyset(&mask) == 0); sigset_add_many(&mask, SIGINT, SIGTERM, -1); assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0); 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; } not_after = now(CLOCK_MONOTONIC) + arg_timeout; fprintf(f, "[Ask]\n" "Socket=%s\n" "NotAfter=%llu\n", socket_name, (unsigned long long) not_after); if (arg_message) fprintf(f, "Message=%s\n", arg_message); if (arg_icon) fprintf(f, "Icon=%s\n", arg_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; } for (;;) { enum { FD_SOCKET, FD_SIGNAL, _FD_MAX }; 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; struct pollfd pollfd[_FD_MAX]; int k; zero(pollfd); pollfd[FD_SOCKET].fd = socket_fd; pollfd[FD_SOCKET].events = POLLIN; pollfd[FD_SIGNAL].fd = signal_fd; pollfd[FD_SIGNAL].events = POLLIN; if ((k = poll(pollfd, 2, arg_timeout/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) break; 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)-1; 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] == '+') { passphrase[n] = 0; fputs(passphrase+1, stdout); fflush(stdout); } 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_fd >= 0) close_nointr_nofail(socket_fd); if (f) fclose(f); unlink(temp); if (final[0]) unlink(final); return r; } static int ask_tty(void) { struct termios old_termios, new_termios; char passphrase[LINE_MAX]; FILE *ttyf; if (!(ttyf = fopen("/dev/tty", "w"))) { log_error("Failed to open /dev/tty: %m"); return -errno; } fputs("\x1B[1m", ttyf); fprintf(ttyf, "%s: ", arg_message); fputs("\x1B[0m", ttyf); fflush(ttyf); if (tcgetattr(STDIN_FILENO, &old_termios) >= 0) { new_termios = old_termios; new_termios.c_lflag &= ~(ICANON|ECHO); new_termios.c_cc[VMIN] = 1; new_termios.c_cc[VTIME] = 0; if (tcsetattr(STDIN_FILENO, TCSADRAIN, &new_termios) >= 0) { size_t p = 0; int r = 0; for (;;) { size_t k; char c; k = fread(&c, 1, 1, stdin); if (k <= 0) { r = -EIO; break; } if (c == '\n') break; else if (c == '\b' || c == 127) { if (p > 0) { p--; fputs("\b \b", ttyf); } } else { passphrase[p++] = c; fputc('*', ttyf); } fflush(ttyf); } fputc('\n', ttyf); fclose(ttyf); tcsetattr(STDIN_FILENO, TCSADRAIN, &old_termios); if (r < 0) return -EIO; passphrase[p] = 0; fputs(passphrase, stdout); fflush(stdout); return 0; } } fclose(ttyf); if (!fgets(passphrase, sizeof(passphrase), stdin)) { log_error("Failed to read password."); return -EIO; } truncate_nl(passphrase); fputs(passphrase, stdout); fflush(stdout); return 0; } int main(int argc, char *argv[]) { int r; log_parse_environment(); log_open(); if ((r = parse_argv(argc, argv)) <= 0) goto finish; if (arg_use_tty && isatty(STDIN_FILENO)) r = ask_tty(); else r = ask_agent(); finish: return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS; }