diff options
Diffstat (limited to 'src/systemd-debug-generator')
| -rw-r--r-- | src/systemd-debug-generator/Makefile | 34 | ||||
| -rw-r--r-- | src/systemd-debug-generator/debug-generator.c | 202 | ||||
| -rw-r--r-- | src/systemd-debug-generator/systemd-debug-generator.xml | 95 |
3 files changed, 331 insertions, 0 deletions
diff --git a/src/systemd-debug-generator/Makefile b/src/systemd-debug-generator/Makefile new file mode 100644 index 0000000000..bba46c2905 --- /dev/null +++ b/src/systemd-debug-generator/Makefile @@ -0,0 +1,34 @@ +# -*- 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-debug-generator + +systemd_debug_generator_SOURCES = \ + src/debug-generator/debug-generator.c + +systemd_debug_generator_LDADD = \ + libshared.la + +include $(topsrcdir)/build-aux/Makefile.tail.mk diff --git a/src/systemd-debug-generator/debug-generator.c b/src/systemd-debug-generator/debug-generator.c new file mode 100644 index 0000000000..2db31e5de6 --- /dev/null +++ b/src/systemd-debug-generator/debug-generator.c @@ -0,0 +1,202 @@ +/*** + This file is part of systemd. + + Copyright 2014 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 "basic/alloc-util.h" +#include "basic/mkdir.h" +#include "basic/parse-util.h" +#include "basic/proc-cmdline.h" +#include "basic/special.h" +#include "basic/string-util.h" +#include "basic/strv.h" +#include "basic/unit-name.h" +#include "basic/util.h" + +static char *arg_default_unit = NULL; +static const char *arg_dest = "/tmp"; +static char **arg_mask = NULL; +static char **arg_wants = NULL; +static bool arg_debug_shell = false; + +static int parse_proc_cmdline_item(const char *key, const char *value) { + int r; + + assert(key); + + if (streq(key, "systemd.mask")) { + + if (!value) + log_error("Missing argument for systemd.mask= kernel command line parameter."); + else { + char *n; + + r = unit_name_mangle(value, UNIT_NAME_NOGLOB, &n); + if (r < 0) + return log_error_errno(r, "Failed to glob unit name: %m"); + + r = strv_consume(&arg_mask, n); + if (r < 0) + return log_oom(); + } + + } else if (streq(key, "systemd.wants")) { + + if (!value) + log_error("Missing argument for systemd.want= kernel command line parameter."); + else { + char *n; + + r = unit_name_mangle(value, UNIT_NAME_NOGLOB, &n); + if (r < 0) + return log_error_errno(r, "Failed to glob unit name: %m"); + + r = strv_consume(&arg_wants, n); + if (r < 0) + return log_oom(); + } + + } else if (streq(key, "systemd.debug-shell")) { + + if (value) { + r = parse_boolean(value); + if (r < 0) + log_error("Failed to parse systemd.debug-shell= argument '%s', ignoring.", value); + else + arg_debug_shell = r; + } else + arg_debug_shell = true; + } else if (streq(key, "systemd.unit")) { + + if (!value) + log_error("Missing argument for systemd.unit= kernel command line parameter."); + else { + r = free_and_strdup(&arg_default_unit, value); + if (r < 0) + return log_error_errno(r, "Failed to set default unit %s: %m", value); + } + } else if (!value) { + const char *target; + + target = runlevel_to_target(key); + if (target) { + r = free_and_strdup(&arg_default_unit, target); + if (r < 0) + return log_error_errno(r, "Failed to set default unit %s: %m", target); + } + } + + return 0; +} + +static int generate_mask_symlinks(void) { + char **u; + int r = 0; + + if (strv_isempty(arg_mask)) + return 0; + + STRV_FOREACH(u, arg_mask) { + _cleanup_free_ char *p = NULL; + + p = strjoin(arg_dest, "/", *u, NULL); + if (!p) + return log_oom(); + + if (symlink("/dev/null", p) < 0) + r = log_error_errno(errno, + "Failed to create mask symlink %s: %m", + p); + } + + return r; +} + +static int generate_wants_symlinks(void) { + char **u; + int r = 0; + + if (strv_isempty(arg_wants)) + return 0; + + STRV_FOREACH(u, arg_wants) { + _cleanup_free_ char *p = NULL, *f = NULL; + + p = strjoin(arg_dest, "/", arg_default_unit, ".wants/", *u, NULL); + if (!p) + return log_oom(); + + f = strappend(SYSTEM_DATA_UNIT_PATH "/", *u); + if (!f) + return log_oom(); + + mkdir_parents_label(p, 0755); + + if (symlink(f, p) < 0) + r = log_error_errno(errno, + "Failed to create wants symlink %s: %m", + p); + } + + return r; +} + +int main(int argc, char *argv[]) { + int r, q; + + if (argc > 1 && argc != 4) { + log_error("This program takes three or no arguments."); + return EXIT_FAILURE; + } + + if (argc > 1) + arg_dest = argv[2]; + + log_set_target(LOG_TARGET_SAFE); + log_parse_environment(); + log_open(); + + umask(0022); + + r = free_and_strdup(&arg_default_unit, SPECIAL_DEFAULT_TARGET); + if (r < 0) { + log_error_errno(r, "Failed to set default unit %s: %m", SPECIAL_DEFAULT_TARGET); + goto finish; + } + + r = parse_proc_cmdline(parse_proc_cmdline_item); + if (r < 0) + log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m"); + + if (arg_debug_shell) { + r = strv_extend(&arg_wants, "debug-shell.service"); + if (r < 0) { + r = log_oom(); + goto finish; + } + } + + r = generate_mask_symlinks(); + + q = generate_wants_symlinks(); + if (q < 0) + r = q; + +finish: + return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS; + +} diff --git a/src/systemd-debug-generator/systemd-debug-generator.xml b/src/systemd-debug-generator/systemd-debug-generator.xml new file mode 100644 index 0000000000..5c5e9fc4a1 --- /dev/null +++ b/src/systemd-debug-generator/systemd-debug-generator.xml @@ -0,0 +1,95 @@ +<?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 2014 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-debug-generator"> + + <refentryinfo> + <title>systemd-debug-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-debug-generator</refentrytitle> + <manvolnum>8</manvolnum> + </refmeta> + + <refnamediv> + <refname>systemd-debug-generator</refname> + <refpurpose>Generator for enabling a runtime debug shell and + masking specific units at boot</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <para><filename>/usr/lib/systemd/system-generators/systemd-debug-generator</filename></para> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><filename>systemd-debug-generator</filename> is a generator + that reads the kernel command line and understands three + options:</para> + + <para>If the <option>systemd.mask=</option> option is specified + and followed by a unit name, this unit is masked for the runtime, + similar to the effect of + <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s + <command>mask</command> command. This is useful to boot with + certain units removed from the initial boot transaction for + debugging system startup. May be specified more than once.</para> + + <para>If the <option>systemd.wants=</option> option is specified + and followed by a unit name, a start job for this unit is added to + the initial transaction. This is useful to start one or more + additional units at boot. May be specified more than once.</para> + + <para>If the <option>systemd.debug-shell</option> option is + specified, the debug shell service + <literal>debug-shell.service</literal> is pulled into the boot + transaction. It will spawn a debug shell on tty9 during early + system startup. Note that the shell may also be turned on + persistently by enabling it with + <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s + <command>enable</command> command.</para> + + <para><filename>systemd-debug-generator</filename> implements + <citerefentry><refentrytitle>systemd.generator</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</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>kernel-command-line</refentrytitle><manvolnum>7</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> |