diff options
Diffstat (limited to 'src/systemd-getty-generator')
| -rw-r--r-- | src/systemd-getty-generator/Makefile | 33 | ||||
| -rw-r--r-- | src/systemd-getty-generator/getty-generator.c | 233 | ||||
| -rw-r--r-- | src/systemd-getty-generator/systemd-getty-generator.xml | 96 |
3 files changed, 362 insertions, 0 deletions
diff --git a/src/systemd-getty-generator/Makefile b/src/systemd-getty-generator/Makefile new file mode 100644 index 0000000000..645dc189f7 --- /dev/null +++ b/src/systemd-getty-generator/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 Jędrzejewski-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 + +systemgenerator_PROGRAMS += systemd-getty-generator +systemd_getty_generator_SOURCES = \ + src/getty-generator/getty-generator.c + +systemd_getty_generator_LDADD = \ + libsystemd-shared.la + +include $(topsrcdir)/build-aux/Makefile.tail.mk diff --git a/src/systemd-getty-generator/getty-generator.c b/src/systemd-getty-generator/getty-generator.c new file mode 100644 index 0000000000..c78fac7694 --- /dev/null +++ b/src/systemd-getty-generator/getty-generator.c @@ -0,0 +1,233 @@ +/*** + 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/>. +***/ + +#include <errno.h> +#include <fcntl.h> +#include <string.h> +#include <unistd.h> + +#include "basic/alloc-util.h" +#include "basic/fd-util.h" +#include "basic/fileio.h" +#include "basic/log.h" +#include "basic/mkdir.h" +#include "basic/path-util.h" +#include "basic/process-util.h" +#include "basic/string-util.h" +#include "basic/terminal-util.h" +#include "basic/unit-name.h" +#include "basic/util.h" +#include "basic/virt.h" + +static const char *arg_dest = "/tmp"; + +static int add_symlink(const char *fservice, const char *tservice) { + char *from, *to; + int r; + + assert(fservice); + assert(tservice); + + from = strjoina(SYSTEM_DATA_UNIT_PATH "/", fservice); + to = strjoina(arg_dest, "/getty.target.wants/", tservice); + + mkdir_parents_label(to, 0755); + + r = symlink(from, to); + if (r < 0) { + /* In case console=hvc0 is passed this will very likely result in EEXIST */ + if (errno == EEXIST) + return 0; + + return log_error_errno(errno, "Failed to create symlink %s: %m", to); + } + + return 0; +} + +static int add_serial_getty(const char *tty) { + _cleanup_free_ char *n = NULL; + int r; + + assert(tty); + + log_debug("Automatically adding serial getty for /dev/%s.", tty); + + r = unit_name_from_path_instance("serial-getty", tty, ".service", &n); + if (r < 0) + return log_error_errno(r, "Failed to generate service name: %m"); + + return add_symlink("serial-getty@.service", n); +} + +static int add_container_getty(const char *tty) { + _cleanup_free_ char *n = NULL; + int r; + + assert(tty); + + log_debug("Automatically adding container getty for /dev/pts/%s.", tty); + + r = unit_name_from_path_instance("container-getty", tty, ".service", &n); + if (r < 0) + return log_error_errno(r, "Failed to generate service name: %m"); + + return add_symlink("container-getty@.service", n); +} + +static int verify_tty(const char *name) { + _cleanup_close_ int fd = -1; + const char *p; + + /* Some TTYs are weird and have been enumerated but don't work + * when you try to use them, such as classic ttyS0 and + * friends. Let's check that and open the device and run + * isatty() on it. */ + + p = strjoina("/dev/", name); + + /* O_NONBLOCK is essential here, to make sure we don't wait + * for DCD */ + fd = open(p, O_RDWR|O_NONBLOCK|O_NOCTTY|O_CLOEXEC|O_NOFOLLOW); + if (fd < 0) + return -errno; + + errno = 0; + if (isatty(fd) <= 0) + return errno > 0 ? -errno : -EIO; + + return 0; +} + +int main(int argc, char *argv[]) { + + static const char virtualization_consoles[] = + "hvc0\0" + "xvc0\0" + "hvsi0\0" + "sclp_line0\0" + "ttysclp0\0" + "3270!tty1\0"; + + _cleanup_free_ char *active = NULL; + const char *j; + int r; + + if (argc > 1 && argc != 4) { + log_error("This program takes three or no arguments."); + return EXIT_FAILURE; + } + + if (argc > 1) + arg_dest = argv[1]; + + log_set_target(LOG_TARGET_SAFE); + log_parse_environment(); + log_open(); + + umask(0022); + + if (detect_container() > 0) { + _cleanup_free_ char *container_ttys = NULL; + + log_debug("Automatically adding console shell."); + + if (add_symlink("console-getty.service", "console-getty.service") < 0) + return EXIT_FAILURE; + + /* When $container_ttys is set for PID 1, spawn + * gettys on all ptys named therein. Note that despite + * the variable name we only support ptys here. */ + + r = getenv_for_pid(1, "container_ttys", &container_ttys); + if (r > 0) { + const char *word, *state; + size_t l; + + FOREACH_WORD(word, l, container_ttys, state) { + const char *t; + char tty[l + 1]; + + memcpy(tty, word, l); + tty[l] = 0; + + /* First strip off /dev/ if it is specified */ + t = path_startswith(tty, "/dev/"); + if (!t) + t = tty; + + /* Then, make sure it's actually a pty */ + t = path_startswith(t, "pts/"); + if (!t) + continue; + + if (add_container_getty(t) < 0) + return EXIT_FAILURE; + } + } + + /* Don't add any further magic if we are in a container */ + return EXIT_SUCCESS; + } + + if (read_one_line_file("/sys/class/tty/console/active", &active) >= 0) { + const char *word, *state; + size_t l; + + /* Automatically add in a serial getty on all active + * kernel consoles */ + FOREACH_WORD(word, l, active, state) { + _cleanup_free_ char *tty = NULL; + + tty = strndup(word, l); + if (!tty) { + log_oom(); + return EXIT_FAILURE; + } + + if (isempty(tty) || tty_is_vc(tty)) + continue; + + if (verify_tty(tty) < 0) + continue; + + /* We assume that gettys on virtual terminals are + * started via manual configuration and do this magic + * only for non-VC terminals. */ + + if (add_serial_getty(tty) < 0) + return EXIT_FAILURE; + } + } + + /* Automatically add in a serial getty on the first + * virtualizer console */ + NULSTR_FOREACH(j, virtualization_consoles) { + char *p; + + p = strjoina("/sys/class/tty/", j); + if (access(p, F_OK) < 0) + continue; + + if (add_serial_getty(j) < 0) + return EXIT_FAILURE; + } + + return EXIT_SUCCESS; +} diff --git a/src/systemd-getty-generator/systemd-getty-generator.xml b/src/systemd-getty-generator/systemd-getty-generator.xml new file mode 100644 index 0000000000..338925964d --- /dev/null +++ b/src/systemd-getty-generator/systemd-getty-generator.xml @@ -0,0 +1,96 @@ +<?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-getty-generator"> + + <refentryinfo> + <title>systemd-getty-generator</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-getty-generator</refentrytitle> + <manvolnum>8</manvolnum> + </refmeta> + + <refnamediv> + <refname>systemd-getty-generator</refname> + <refpurpose>Generator for enabling getty instances on the + console</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <para><filename>/usr/lib/systemd/system-generators/systemd-getty-generator</filename></para> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><filename>systemd-getty-generator</filename> is a generator + that automatically instantiates + <filename>serial-getty@.service</filename> on the kernel console + <filename>/dev/console</filename> if that is not directed to the + virtual console subsystem. It will also instantiate + <filename>serial-getty@.service</filename> instances for + virtualizer consoles, if execution in a virtualized environment is + detected. Finally, it will instantiate + <filename>container-getty@.service</filename> instances for + additional container pseudo TTYs as requested by the container + manager (see <ulink + url="http://www.freedesktop.org/wiki/Software/systemd/ContainerInterface/"><filename>Container + Interface</filename></ulink>). This should ensure that the user is + shown a login prompt at the right place, regardless of which + environment the system is started in. For example, it is + sufficient to redirect the kernel console with a kernel command + line argument such as <varname>console=</varname> to get both + kernel messages and a getty prompt on a serial TTY. See <ulink + url="https://www.kernel.org/doc/Documentation/kernel-parameters.txt"><filename>kernel-parameters.txt</filename></ulink> + for more information on the <varname>console=</varname> kernel + parameter.</para> + + <para><filename>systemd-getty-generator</filename> implements + <citerefentry><refentrytitle>systemd.generator</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para> + + <para>Further information about configuration of gettys you may + find in + <ulink url="http://0pointer.de/blog/projects/serial-console.html">systemd + for Administrators, Part XVI: Gettys on Serial Consoles (and + Elsewhere)</ulink>.</para> + </refsect1> + + <refsect1> + <title>See Also</title> + <para> + <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>agetty</refentrytitle><manvolnum>8</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> |