diff options
Diffstat (limited to 'src/systemd-tty-ask-password-agent')
6 files changed, 1165 insertions, 0 deletions
diff --git a/src/systemd-tty-ask-password-agent/GNUmakefile b/src/systemd-tty-ask-password-agent/GNUmakefile new file mode 120000 index 0000000000..54fdd42278 --- /dev/null +++ b/src/systemd-tty-ask-password-agent/GNUmakefile @@ -0,0 +1 @@ +../../GNUmakefile
\ No newline at end of file diff --git a/src/systemd-tty-ask-password-agent/Makefile b/src/systemd-tty-ask-password-agent/Makefile new file mode 100644 index 0000000000..3091527a7f --- /dev/null +++ b/src/systemd-tty-ask-password-agent/Makefile @@ -0,0 +1,33 @@ +# -*- Mode: makefile; indent-tabs-mode: t -*- +# +# This file is part of systemd. +# +# Copyright 2010-2012 Lennart Poettering +# Copyright 2010-2012 Kay Sievers +# Copyright 2013 Zbigniew JÄ™drzejewski-Szmek +# Copyright 2013 David Strauss +# Copyright 2016 Luke Shumaker +# +# systemd is free software; you can redistribute it and/or modify it +# under the terms of the GNU Lesser General Public License as published by +# the Free Software Foundation; either version 2.1 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 +# Lesser General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with systemd; If not, see <http://www.gnu.org/licenses/>. +include $(dir $(lastword $(MAKEFILE_LIST)))/../../config.mk +include $(topsrcdir)/build-aux/Makefile.head.mk + +rootbin_PROGRAMS += systemd-tty-ask-password-agent +systemd_tty_ask_password_agent_SOURCES = \ + src/tty-ask-password-agent/tty-ask-password-agent.c + +systemd_tty_ask_password_agent_LDADD = \ + libsystemd-shared.la + +include $(topsrcdir)/build-aux/Makefile.tail.mk diff --git a/src/systemd-tty-ask-password-agent/systemd-ask-password-console.service.xml b/src/systemd-tty-ask-password-agent/systemd-ask-password-console.service.xml new file mode 100644 index 0000000000..479e5f2e5b --- /dev/null +++ b/src/systemd-tty-ask-password-agent/systemd-ask-password-console.service.xml @@ -0,0 +1,93 @@ +<?xml version="1.0"?> +<!--*-nxml-*--> +<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> +<!-- + This file is part of systemd. + + Copyright 2012 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +--> +<refentry id="systemd-ask-password-console.service"> + + <refentryinfo> + <title>systemd-ask-password-console.service</title> + <productname>systemd</productname> + + <authorgroup> + <author> + <contrib>Developer</contrib> + <firstname>Lennart</firstname> + <surname>Poettering</surname> + <email>lennart@poettering.net</email> + </author> + </authorgroup> + </refentryinfo> + + <refmeta> + <refentrytitle>systemd-ask-password-console.service</refentrytitle> + <manvolnum>8</manvolnum> + </refmeta> + + <refnamediv> + <refname>systemd-ask-password-console.service</refname> + <refname>systemd-ask-password-console.path</refname> + <refname>systemd-ask-password-wall.service</refname> + <refname>systemd-ask-password-wall.path</refname> + <refpurpose>Query the user for system passwords on the + console and via wall</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <para><filename>systemd-ask-password-console.service</filename></para> + <para><filename>systemd-ask-password-console.path</filename></para> + <para><filename>systemd-ask-password-wall.service</filename></para> + <para><filename>systemd-ask-password-wall.path</filename></para> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><filename>systemd-ask-password-console.service</filename> is + a system service that queries the user for system passwords (such + as hard disk encryption keys and SSL certificate passphrases) on + the console. It is intended to be used during boot to ensure + proper handling of passwords necessary for boot. + <filename>systemd-ask-password-wall.service</filename> is a system + service that informs all logged in users for system passwords via + <citerefentry project='man-pages'><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>. + It is intended to be used after boot to ensure that users are + properly notified.</para> + + <para>See the <ulink + url="http://www.freedesktop.org/wiki/Software/systemd/PasswordAgents"> + developer documentation</ulink> for more information about the + system password logic.</para> + + <para>Note that these services invoke + <citerefentry><refentrytitle>systemd-tty-ask-password-agent</refentrytitle><manvolnum>1</manvolnum></citerefentry> + with either the <command>--watch --console</command> or + <command>--watch --wall</command> command line parameters.</para> + </refsect1> + + <refsect1> + <title>See Also</title> + <para> + <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd-tty-ask-password-agent</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> diff --git a/src/systemd-tty-ask-password-agent/systemd-tty-ask-password-agent.completion.zsh b/src/systemd-tty-ask-password-agent/systemd-tty-ask-password-agent.completion.zsh new file mode 100644 index 0000000000..e7c0684996 --- /dev/null +++ b/src/systemd-tty-ask-password-agent/systemd-tty-ask-password-agent.completion.zsh @@ -0,0 +1,14 @@ +#compdef systemd-tty-ask-password-agent + +local curcontext="$curcontext" state lstate line +_arguments \ + {-h,--help}'[Prints a short help text and exits.]' \ + '--version[Prints a short version string and exits.]' \ + '--list[Lists all currently pending system password requests.]' \ + '--query[Process all currently pending system password requests by querying the user on the calling TTY.]' \ + '--watch[Continuously process password requests.]' \ + '--wall[Forward password requests to wall(1).]' \ + '--plymouth[Ask question with plymouth(8).]' \ + '--console[Ask question on /dev/console.]' + +#vim: set ft=zsh sw=4 ts=4 et diff --git a/src/systemd-tty-ask-password-agent/systemd-tty-ask-password-agent.xml b/src/systemd-tty-ask-password-agent/systemd-tty-ask-password-agent.xml new file mode 100644 index 0000000000..2876fab644 --- /dev/null +++ b/src/systemd-tty-ask-password-agent/systemd-tty-ask-password-agent.xml @@ -0,0 +1,149 @@ +<?xml version='1.0'?> <!--*-nxml-*--> +<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" + "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> + +<!-- + 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 Lesser General Public License as published by + the Free Software Foundation; either version 2.1 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +--> + +<refentry id="systemd-tty-ask-password-agent" + xmlns:xi="http://www.w3.org/2001/XInclude"> + + <refentryinfo> + <title>systemd-tty-ask-password-agent</title> + <productname>systemd</productname> + + <authorgroup> + <author> + <contrib>Developer</contrib> + <firstname>Lennart</firstname> + <surname>Poettering</surname> + <email>lennart@poettering.net</email> + </author> + </authorgroup> + </refentryinfo> + + <refmeta> + <refentrytitle>systemd-tty-ask-password-agent</refentrytitle> + <manvolnum>1</manvolnum> + </refmeta> + + <refnamediv> + <refname>systemd-tty-ask-password-agent</refname> + <refpurpose>List or process pending systemd password requests</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <cmdsynopsis> + <command>systemd-tty-ask-password-agent <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="opt" rep="repeat">VARIABLE=VALUE</arg></command> + </cmdsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><command>systemd-tty-ask-password-agent</command> is a + password agent that handles password requests of the system, for + example for hard disk encryption passwords or SSL certificate + passwords that need to be queried at boot-time or during + runtime.</para> + + <para><command>systemd-tty-ask-password-agent</command> implements + the <ulink url="http://www.freedesktop.org/wiki/Software/systemd/PasswordAgents">Password + Agents Specification</ulink>.</para> + + </refsect1> + + <refsect1> + <title>Options</title> + + <para>The following options are understood:</para> + + <variablelist> + <varlistentry> + <term><option>--list</option></term> + + <listitem><para>Lists all currently pending system password requests.</para></listitem> + </varlistentry> + + <varlistentry> + <term><option>--query</option></term> + + <listitem><para>Process all currently pending system password + requests by querying the user on the calling + TTY.</para></listitem> + </varlistentry> + + <varlistentry> + <term><option>--watch</option></term> + + <listitem><para>Continuously process password + requests.</para></listitem> + </varlistentry> + + <varlistentry> + <term><option>--wall</option></term> + + <listitem><para>Forward password requests to + <citerefentry project='man-pages'><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry> + instead of querying the user on the calling + TTY.</para></listitem> + </varlistentry> + + <varlistentry> + <term><option>--plymouth</option></term> + + <listitem><para>Ask question with + <citerefentry project='die-net'><refentrytitle>plymouth</refentrytitle><manvolnum>8</manvolnum></citerefentry> + instead of querying the user on the calling + TTY.</para></listitem> + </varlistentry> + + <varlistentry> + <term><option>--console</option></term> + + <listitem><para>Ask question on + <filename>/dev/console</filename> instead of querying the user + on the calling TTY. </para></listitem> + </varlistentry> + + <xi:include href="standard-options.xml" xpointer="help" /> + <xi:include href="standard-options.xml" xpointer="version" /> + </variablelist> + + </refsect1> + + <refsect1> + <title>Exit status</title> + + <para>On success, 0 is returned, a non-zero failure + code otherwise.</para> + </refsect1> + + <refsect1> + <title>See Also</title> + <para> + <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd-ask-password-console.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry project='die-net'><refentrytitle>plymouth</refentrytitle><manvolnum>8</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> diff --git a/src/systemd-tty-ask-password-agent/tty-ask-password-agent.c b/src/systemd-tty-ask-password-agent/tty-ask-password-agent.c new file mode 100644 index 0000000000..609944d6a4 --- /dev/null +++ b/src/systemd-tty-ask-password-agent/tty-ask-password-agent.c @@ -0,0 +1,875 @@ +/*** + This file is part of systemd. + + Copyright 2010 Lennart Poettering + Copyright 2015 Werner Fink + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <errno.h> +#include <fcntl.h> +#include <getopt.h> +#include <poll.h> +#include <signal.h> +#include <stdbool.h> +#include <stddef.h> +#include <string.h> +#include <sys/inotify.h> +#include <sys/prctl.h> +#include <sys/signalfd.h> +#include <sys/socket.h> +#include <sys/un.h> +#include <sys/wait.h> +#include <unistd.h> + +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/def.h" +#include "systemd-basic/dirent-util.h" +#include "systemd-basic/exit-status.h" +#include "systemd-basic/fd-util.h" +#include "systemd-basic/fileio.h" +#include "systemd-basic/hashmap.h" +#include "systemd-basic/io-util.h" +#include "systemd-basic/macro.h" +#include "systemd-basic/mkdir.h" +#include "systemd-basic/path-util.h" +#include "systemd-basic/process-util.h" +#include "systemd-basic/signal-util.h" +#include "systemd-basic/socket-util.h" +#include "systemd-basic/string-util.h" +#include "systemd-basic/strv.h" +#include "systemd-basic/terminal-util.h" +#include "systemd-basic/util.h" +#include "systemd-shared/ask-password-api.h" +#include "systemd-shared/conf-parser.h" +#include "systemd-shared/utmp-wtmp.h" + +static enum { + ACTION_LIST, + ACTION_QUERY, + ACTION_WATCH, + ACTION_WALL +} arg_action = ACTION_QUERY; + +static bool arg_plymouth = false; +static bool arg_console = false; +static const char *arg_device = NULL; + +static int ask_password_plymouth( + const char *message, + usec_t until, + AskPasswordFlags flags, + const char *flag_file, + char ***ret) { + + static const union sockaddr_union sa = PLYMOUTH_SOCKET; + _cleanup_close_ int fd = -1, notify = -1; + _cleanup_free_ char *packet = NULL; + ssize_t k; + int r, n; + struct pollfd pollfd[2] = {}; + char buffer[LINE_MAX]; + size_t p = 0; + enum { + POLL_SOCKET, + POLL_INOTIFY + }; + + assert(ret); + + if (flag_file) { + notify = inotify_init1(IN_CLOEXEC|IN_NONBLOCK); + if (notify < 0) + return -errno; + + r = inotify_add_watch(notify, flag_file, IN_ATTRIB); /* for the link count */ + if (r < 0) + return -errno; + } + + fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); + if (fd < 0) + return -errno; + + r = connect(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un)); + if (r < 0) + return -errno; + + if (flags & ASK_PASSWORD_ACCEPT_CACHED) { + packet = strdup("c"); + n = 1; + } else if (asprintf(&packet, "*\002%c%s%n", (int) (strlen(message) + 1), message, &n) < 0) + packet = NULL; + if (!packet) + return -ENOMEM; + + r = loop_write(fd, packet, n + 1, true); + if (r < 0) + return r; + + pollfd[POLL_SOCKET].fd = fd; + pollfd[POLL_SOCKET].events = POLLIN; + pollfd[POLL_INOTIFY].fd = notify; + pollfd[POLL_INOTIFY].events = POLLIN; + + for (;;) { + int sleep_for = -1, j; + + 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 && access(flag_file, F_OK) < 0) { + r = -errno; + goto finish; + } + + j = poll(pollfd, notify >= 0 ? 2 : 1, sleep_for); + if (j < 0) { + if (errno == EINTR) + continue; + + r = -errno; + goto finish; + } else if (j == 0) { + r = -ETIME; + goto finish; + } + + if (notify >= 0 && pollfd[POLL_INOTIFY].revents != 0) + flush_fd(notify); + + if (pollfd[POLL_SOCKET].revents == 0) + continue; + + k = read(fd, buffer + p, sizeof(buffer) - p); + if (k < 0) { + if (errno == EINTR || errno == EAGAIN) + continue; + + r = -errno; + goto finish; + } else if (k == 0) { + r = -EIO; + goto finish; + } + + p += k; + + if (p < 1) + continue; + + if (buffer[0] == 5) { + + if (flags & ASK_PASSWORD_ACCEPT_CACHED) { + /* Hmm, first try with cached + * passwords failed, so let's retry + * with a normal password request */ + packet = mfree(packet); + + if (asprintf(&packet, "*\002%c%s%n", (int) (strlen(message) + 1), message, &n) < 0) { + r = -ENOMEM; + goto finish; + } + + r = loop_write(fd, packet, n+1, true); + if (r < 0) + goto finish; + + flags &= ~ASK_PASSWORD_ACCEPT_CACHED; + p = 0; + continue; + } + + /* No password, because UI not shown */ + r = -ENOENT; + goto finish; + + } else if (buffer[0] == 2 || buffer[0] == 9) { + uint32_t size; + char **l; + + /* One or more answers */ + if (p < 5) + continue; + + memcpy(&size, buffer+1, sizeof(size)); + size = le32toh(size); + if (size + 5 > sizeof(buffer)) { + r = -EIO; + goto finish; + } + + if (p-5 < size) + continue; + + l = strv_parse_nulstr(buffer + 5, size); + if (!l) { + r = -ENOMEM; + goto finish; + } + + *ret = l; + break; + + } else { + /* Unknown packet */ + r = -EIO; + goto finish; + } + } + + r = 0; + +finish: + memory_erase(buffer, sizeof(buffer)); + return r; +} + +static int send_passwords(const char *socket_name, char **passwords) { + _cleanup_free_ char *packet = NULL; + _cleanup_close_ int socket_fd = -1; + union sockaddr_union sa = { .un.sun_family = AF_UNIX }; + size_t packet_length = 1; + char **p, *d; + int r; + + assert(socket_name); + + STRV_FOREACH(p, passwords) + packet_length += strlen(*p) + 1; + + packet = new(char, packet_length); + if (!packet) + return -ENOMEM; + + packet[0] = '+'; + + d = packet + 1; + STRV_FOREACH(p, passwords) + d = stpcpy(d, *p) + 1; + + socket_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0); + if (socket_fd < 0) { + r = log_debug_errno(errno, "socket(): %m"); + goto finish; + } + + strncpy(sa.un.sun_path, socket_name, sizeof(sa.un.sun_path)); + + r = sendto(socket_fd, packet, packet_length, MSG_NOSIGNAL, &sa.sa, SOCKADDR_UN_LEN(sa.un)); + if (r < 0) + r = log_debug_errno(errno, "sendto(): %m"); + +finish: + memory_erase(packet, packet_length); + return r; +} + +static int parse_password(const char *filename, char **wall) { + _cleanup_free_ char *socket_name = NULL, *message = NULL; + bool accept_cached = false, echo = false; + uint64_t not_after = 0; + unsigned pid = 0; + + const ConfigTableItem items[] = { + { "Ask", "Socket", config_parse_string, 0, &socket_name }, + { "Ask", "NotAfter", config_parse_uint64, 0, ¬_after }, + { "Ask", "Message", config_parse_string, 0, &message }, + { "Ask", "PID", config_parse_unsigned, 0, &pid }, + { "Ask", "AcceptCached", config_parse_bool, 0, &accept_cached }, + { "Ask", "Echo", config_parse_bool, 0, &echo }, + {} + }; + + int r; + + assert(filename); + + r = config_parse(NULL, filename, NULL, + NULL, + config_item_table_lookup, items, + true, false, true, NULL); + if (r < 0) + return r; + + if (!socket_name) { + log_error("Invalid password file %s", filename); + return -EBADMSG; + } + + if (not_after > 0 && now(CLOCK_MONOTONIC) > not_after) + return 0; + + if (pid > 0 && !pid_is_alive(pid)) + return 0; + + if (arg_action == ACTION_LIST) + printf("'%s' (PID %u)\n", message, pid); + + else if (arg_action == ACTION_WALL) { + char *_wall; + + if (asprintf(&_wall, + "%s%sPassword entry required for \'%s\' (PID %u).\r\n" + "Please enter password with the systemd-tty-ask-password-agent tool!", + strempty(*wall), + *wall ? "\r\n\r\n" : "", + message, + pid) < 0) + return log_oom(); + + free(*wall); + *wall = _wall; + + } else { + _cleanup_strv_free_erase_ char **passwords = NULL; + + assert(arg_action == ACTION_QUERY || + arg_action == ACTION_WATCH); + + if (access(socket_name, W_OK) < 0) { + if (arg_action == ACTION_QUERY) + log_info("Not querying '%s' (PID %u), lacking privileges.", message, pid); + + return 0; + } + + if (arg_plymouth) + r = ask_password_plymouth(message, not_after, accept_cached ? ASK_PASSWORD_ACCEPT_CACHED : 0, filename, &passwords); + else { + char *password = NULL; + int tty_fd = -1; + + if (arg_console) { + const char *con = arg_device ? arg_device : "/dev/console"; + + tty_fd = acquire_terminal(con, false, false, false, USEC_INFINITY); + if (tty_fd < 0) + return log_error_errno(tty_fd, "Failed to acquire /dev/console: %m"); + + r = reset_terminal_fd(tty_fd, true); + if (r < 0) + log_warning_errno(r, "Failed to reset terminal, ignoring: %m"); + } + + r = ask_password_tty(message, NULL, not_after, echo ? ASK_PASSWORD_ECHO : 0, filename, &password); + + if (arg_console) { + tty_fd = safe_close(tty_fd); + release_terminal(); + } + + if (r >= 0) + r = strv_push(&passwords, password); + + if (r < 0) + string_free_erase(password); + } + + /* If the query went away, that's OK */ + if (IN_SET(r, -ETIME, -ENOENT)) + return 0; + + if (r < 0) + return log_error_errno(r, "Failed to query password: %m"); + + r = send_passwords(socket_name, passwords); + if (r < 0) + return log_error_errno(r, "Failed to send: %m"); + } + + return 0; +} + +static int wall_tty_block(void) { + _cleanup_free_ char *p = NULL; + dev_t devnr; + int fd, r; + + r = get_ctty_devnr(0, &devnr); + if (r == -ENXIO) /* We have no controlling tty */ + return -ENOTTY; + if (r < 0) + return log_error_errno(r, "Failed to get controlling TTY: %m"); + + if (asprintf(&p, "/run/systemd/ask-password-block/%u:%u", major(devnr), minor(devnr)) < 0) + return log_oom(); + + mkdir_parents_label(p, 0700); + mkfifo(p, 0600); + + fd = open(p, O_RDONLY|O_CLOEXEC|O_NONBLOCK|O_NOCTTY); + if (fd < 0) + return log_debug_errno(errno, "Failed to open %s: %m", p); + + return fd; +} + +static bool wall_tty_match(const char *path, void *userdata) { + _cleanup_free_ char *p = NULL; + _cleanup_close_ int fd = -1; + struct stat st; + + if (!path_is_absolute(path)) + path = strjoina("/dev/", path); + + if (lstat(path, &st) < 0) { + log_debug_errno(errno, "Failed to stat %s: %m", path); + return true; + } + + if (!S_ISCHR(st.st_mode)) { + log_debug("%s is not a character device.", path); + return true; + } + + /* We use named pipes to ensure that wall messages suggesting + * password entry are not printed over password prompts + * already shown. We use the fact here that opening a pipe in + * non-blocking mode for write-only will succeed only if + * there's some writer behind it. Using pipes has the + * advantage that the block will automatically go away if the + * process dies. */ + + if (asprintf(&p, "/run/systemd/ask-password-block/%u:%u", major(st.st_rdev), minor(st.st_rdev)) < 0) { + log_oom(); + return true; + } + + fd = open(p, O_WRONLY|O_CLOEXEC|O_NONBLOCK|O_NOCTTY); + if (fd < 0) { + log_debug_errno(errno, "Failed top open the wall pipe: %m"); + return 1; + } + + /* What, we managed to open the pipe? Then this tty is filtered. */ + return 0; +} + +static int show_passwords(void) { + _cleanup_closedir_ DIR *d; + struct dirent *de; + int r = 0; + + d = opendir("/run/systemd/ask-password"); + if (!d) { + if (errno == ENOENT) + return 0; + + return log_error_errno(errno, "Failed to open /run/systemd/ask-password: %m"); + } + + FOREACH_DIRENT_ALL(de, d, return log_error_errno(errno, "Failed to read directory: %m")) { + _cleanup_free_ char *p = NULL, *wall = NULL; + int q; + + /* We only support /dev on tmpfs, hence we can rely on + * d_type to be reliable */ + + if (de->d_type != DT_REG) + continue; + + if (hidden_or_backup_file(de->d_name)) + continue; + + if (!startswith(de->d_name, "ask.")) + continue; + + p = strappend("/run/systemd/ask-password/", de->d_name); + if (!p) + return log_oom(); + + q = parse_password(p, &wall); + if (q < 0 && r == 0) + r = q; + + if (wall) + (void) utmp_wall(wall, NULL, NULL, wall_tty_match, NULL); + } + + return r; +} + +static int watch_passwords(void) { + enum { + FD_INOTIFY, + FD_SIGNAL, + _FD_MAX + }; + + _cleanup_close_ int notify = -1, signal_fd = -1, tty_block_fd = -1; + struct pollfd pollfd[_FD_MAX] = {}; + sigset_t mask; + int r; + + tty_block_fd = wall_tty_block(); + + (void) mkdir_p_label("/run/systemd/ask-password", 0755); + + notify = inotify_init1(IN_CLOEXEC); + if (notify < 0) + return log_error_errno(errno, "Failed to allocate directory watch: %m"); + + if (inotify_add_watch(notify, "/run/systemd/ask-password", IN_CLOSE_WRITE|IN_MOVED_TO) < 0) + return log_error_errno(errno, "Failed to add /run/systemd/ask-password to directory watch: %m"); + + assert_se(sigemptyset(&mask) >= 0); + assert_se(sigset_add_many(&mask, SIGINT, SIGTERM, -1) >= 0); + assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) >= 0); + + signal_fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC); + if (signal_fd < 0) + return log_error_errno(errno, "Failed to allocate signal file descriptor: %m"); + + pollfd[FD_INOTIFY].fd = notify; + pollfd[FD_INOTIFY].events = POLLIN; + pollfd[FD_SIGNAL].fd = signal_fd; + pollfd[FD_SIGNAL].events = POLLIN; + + for (;;) { + r = show_passwords(); + if (r < 0) + log_error_errno(r, "Failed to show password: %m"); + + if (poll(pollfd, _FD_MAX, -1) < 0) { + if (errno == EINTR) + continue; + + return -errno; + } + + if (pollfd[FD_INOTIFY].revents != 0) + (void) flush_fd(notify); + + if (pollfd[FD_SIGNAL].revents != 0) + break; + } + + return 0; +} + +static void help(void) { + printf("%s [OPTIONS...]\n\n" + "Process system password requests.\n\n" + " -h --help Show this help\n" + " --version Show package version\n" + " --list Show pending password requests\n" + " --query Process pending password requests\n" + " --watch Continuously process password requests\n" + " --wall Continuously forward password requests to wall\n" + " --plymouth Ask question with Plymouth instead of on TTY\n" + " --console Ask question on /dev/console instead of current TTY\n", + program_invocation_short_name); +} + +static int parse_argv(int argc, char *argv[]) { + + enum { + ARG_LIST = 0x100, + ARG_QUERY, + ARG_WATCH, + ARG_WALL, + ARG_PLYMOUTH, + ARG_CONSOLE, + ARG_VERSION + }; + + static const struct option options[] = { + { "help", no_argument, NULL, 'h' }, + { "version", no_argument, NULL, ARG_VERSION }, + { "list", no_argument, NULL, ARG_LIST }, + { "query", no_argument, NULL, ARG_QUERY }, + { "watch", no_argument, NULL, ARG_WATCH }, + { "wall", no_argument, NULL, ARG_WALL }, + { "plymouth", no_argument, NULL, ARG_PLYMOUTH }, + { "console", optional_argument, NULL, ARG_CONSOLE }, + {} + }; + + 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_VERSION: + return version(); + + case ARG_LIST: + arg_action = ACTION_LIST; + break; + + case ARG_QUERY: + arg_action = ACTION_QUERY; + break; + + case ARG_WATCH: + arg_action = ACTION_WATCH; + break; + + case ARG_WALL: + arg_action = ACTION_WALL; + break; + + case ARG_PLYMOUTH: + arg_plymouth = true; + break; + + case ARG_CONSOLE: + arg_console = true; + if (optarg) { + + if (isempty(optarg)) { + log_error("Empty console device path is not allowed."); + return -EINVAL; + } + + arg_device = optarg; + } + break; + + case '?': + return -EINVAL; + + default: + assert_not_reached("Unhandled option"); + } + + if (optind != argc) { + log_error("%s takes no arguments.", program_invocation_short_name); + return -EINVAL; + } + + if (arg_plymouth || arg_console) { + + if (!IN_SET(arg_action, ACTION_QUERY, ACTION_WATCH)) { + log_error("Options --query and --watch conflict."); + return -EINVAL; + } + + if (arg_plymouth && arg_console) { + log_error("Options --plymouth and --console conflict."); + return -EINVAL; + } + } + + return 1; +} + +/* + * To be able to ask on all terminal devices of /dev/console + * the devices are collected. If more than one device is found, + * then on each of the terminals a inquiring task is forked. + * Every task has its own session and its own controlling terminal. + * If one of the tasks does handle a password, the remaining tasks + * will be terminated. + */ +static int ask_on_this_console(const char *tty, pid_t *pid, int argc, char *argv[]) { + struct sigaction sig = { + .sa_handler = nop_signal_handler, + .sa_flags = SA_NOCLDSTOP | SA_RESTART, + }; + + assert_se(sigprocmask_many(SIG_UNBLOCK, NULL, SIGHUP, SIGCHLD, -1) >= 0); + + assert_se(sigemptyset(&sig.sa_mask) >= 0); + assert_se(sigaction(SIGCHLD, &sig, NULL) >= 0); + + sig.sa_handler = SIG_DFL; + assert_se(sigaction(SIGHUP, &sig, NULL) >= 0); + + *pid = fork(); + if (*pid < 0) + return log_error_errno(errno, "Failed to fork process: %m"); + + if (*pid == 0) { + int ac; + + assert_se(prctl(PR_SET_PDEATHSIG, SIGHUP) >= 0); + + reset_signal_mask(); + reset_all_signal_handlers(); + + for (ac = 0; ac < argc; ac++) { + if (streq(argv[ac], "--console")) { + argv[ac] = strjoina("--console=", tty, NULL); + break; + } + } + + assert(ac < argc); + + execv(SYSTEMD_TTY_ASK_PASSWORD_AGENT_BINARY_PATH, argv); + _exit(EXIT_FAILURE); + } + return 0; +} + +static void terminate_agents(Set *pids) { + struct timespec ts; + siginfo_t status = {}; + sigset_t set; + Iterator i; + void *p; + int r, signum; + + /* + * Request termination of the remaining processes as those + * are not required anymore. + */ + SET_FOREACH(p, pids, i) + (void) kill(PTR_TO_PID(p), SIGTERM); + + /* + * Collect the processes which have go away. + */ + assert_se(sigemptyset(&set) >= 0); + assert_se(sigaddset(&set, SIGCHLD) >= 0); + timespec_store(&ts, 50 * USEC_PER_MSEC); + + while (!set_isempty(pids)) { + + zero(status); + r = waitid(P_ALL, 0, &status, WEXITED|WNOHANG); + if (r < 0 && errno == EINTR) + continue; + + if (r == 0 && status.si_pid > 0) { + set_remove(pids, PID_TO_PTR(status.si_pid)); + continue; + } + + signum = sigtimedwait(&set, NULL, &ts); + if (signum < 0) { + if (errno != EAGAIN) + log_error_errno(errno, "sigtimedwait() failed: %m"); + break; + } + assert(signum == SIGCHLD); + } + + /* + * Kill hanging processes. + */ + SET_FOREACH(p, pids, i) { + log_warning("Failed to terminate child %d, killing it", PTR_TO_PID(p)); + (void) kill(PTR_TO_PID(p), SIGKILL); + } +} + +static int ask_on_consoles(int argc, char *argv[]) { + _cleanup_set_free_ Set *pids = NULL; + _cleanup_strv_free_ char **consoles = NULL; + siginfo_t status = {}; + char **tty; + pid_t pid; + int r; + + r = get_kernel_consoles(&consoles); + if (r < 0) + return log_error_errno(r, "Failed to determine devices of /dev/console: %m"); + + pids = set_new(NULL); + if (!pids) + return log_oom(); + + /* Start an agent on each console. */ + STRV_FOREACH(tty, consoles) { + r = ask_on_this_console(*tty, &pid, argc, argv); + if (r < 0) + return r; + + if (set_put(pids, PID_TO_PTR(pid)) < 0) + return log_oom(); + } + + /* Wait for an agent to exit. */ + for (;;) { + zero(status); + + if (waitid(P_ALL, 0, &status, WEXITED) < 0) { + if (errno == EINTR) + continue; + + return log_error_errno(errno, "waitid() failed: %m"); + } + + set_remove(pids, PID_TO_PTR(status.si_pid)); + break; + } + + if (!is_clean_exit(status.si_code, status.si_status, EXIT_CLEAN_DAEMON, NULL)) + log_error("Password agent failed with: %d", status.si_status); + + terminate_agents(pids); + return 0; +} + +int main(int argc, char *argv[]) { + int r; + + log_set_target(LOG_TARGET_AUTO); + log_parse_environment(); + log_open(); + + umask(0022); + + r = parse_argv(argc, argv); + if (r <= 0) + goto finish; + + if (arg_console && !arg_device) + /* + * Spawn for each console device a separate process. + */ + r = ask_on_consoles(argc, argv); + else { + + if (arg_device) { + /* + * Later on, a controlling terminal will be acquired, + * therefore the current process has to become a session + * leader and should not have a controlling terminal already. + */ + (void) setsid(); + (void) release_terminal(); + } + + if (IN_SET(arg_action, ACTION_WATCH, ACTION_WALL)) + r = watch_passwords(); + else + r = show_passwords(); + } + +finish: + return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS; +} |