src/debug-generator/debug-generator.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2014 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include "util.h"
  23 #include "strv.h"
  24 #include "unit-name.h"
  25 #include "mkdir.h"
  26
  27 static const char *arg_dest = "/tmp";
  28 static char **arg_mask = NULL;
  29 static char **arg_wants = NULL;
  30 static bool arg_debug_shell = false;
  31
  32 static int parse_proc_cmdline_item(const char *key, const char *value) {
  33         int r;
  34
  35         assert(key);
  36
  37         if (streq(key, "systemd.mask")) {
  38
  39                 if (!value)
  40                         log_error("Missing argument for systemd.mask= kernel command line parameter.");
  41                 else {
  42                         char *n;
  43
  44                         n = unit_name_mangle(value, MANGLE_NOGLOB);
  45                         if (!n)
  46                                 return log_oom();
  47
  48                         r = strv_consume(&arg_mask, n);
  49                         if (r < 0)
  50                                 return log_oom();
  51                 }
  52
  53         } else if (streq(key, "systemd.wants")) {
  54
  55                 if (!value)
  56                         log_error("Missing argument for systemd.want= kernel command line parameter.");
  57                 else {
  58                         char *n;
  59
  60                         n = unit_name_mangle(value, MANGLE_NOGLOB);
  61                         if (!n)
  62                                 return log_oom();
  63
  64                         r = strv_consume(&arg_wants, n);
  65                         if (r < 0)
  66                                 return log_oom();
  67                 }
  68
  69         } else if (streq(key, "systemd.debug-shell")) {
  70
  71                 if (value) {
  72                         r = parse_boolean(value);
  73                         if (r < 0)
  74                                 log_error("Failed to parse systemd.debug-shell= argument '%s', ignoring.", value);
  75                         else
  76                                 arg_debug_shell = r;
  77                 } else
  78                         arg_debug_shell = true;
  79         }
  80
  81         return 0;
  82 }
  83
  84 static int generate_mask_symlinks(void) {
  85         char **u;
  86         int r = 0;
  87
  88         if (strv_isempty(arg_mask))
  89                 return 0;
  90
  91         STRV_FOREACH(u, arg_mask) {
  92                 _cleanup_free_ char *p = NULL;
  93
  94                 p = strjoin(arg_dest, "/", *u, NULL);
  95                 if (!p)
  96                         return log_oom();
  97
  98                 if (symlink("/dev/null", p) < 0) {
  99                         log_error_errno(errno, "Failed to create mask symlink %s: %m", p);
 100                         r = -errno;
 101                 }
 102         }
 103
 104         return r;
 105 }
 106
 107 static int generate_wants_symlinks(void) {
 108         char **u;
 109         int r = 0;
 110
 111         if (strv_isempty(arg_wants))
 112                 return 0;
 113
 114         STRV_FOREACH(u, arg_wants) {
 115                 _cleanup_free_ char *p = NULL, *f = NULL;
 116
 117                 p = strjoin(arg_dest, "/default.target.wants/", *u, NULL);
 118                 if (!p)
 119                         return log_oom();
 120
 121                 f = strappend(SYSTEM_DATA_UNIT_PATH "/", *u);
 122                 if (!f)
 123                         return log_oom();
 124
 125                 mkdir_parents_label(p, 0755);
 126
 127                 if (symlink(f, p) < 0) {
 128                         log_error_errno(errno, "Failed to create wants symlink %s: %m", p);
 129                         r = -errno;
 130                 }
 131         }
 132
 133         return r;
 134 }
 135
 136 int main(int argc, char *argv[]) {
 137         int r, q;
 138
 139         if (argc > 1 && argc != 4) {
 140                 log_error("This program takes three or no arguments.");
 141                 return EXIT_FAILURE;
 142         }
 143
 144         if (argc > 1)
 145                 arg_dest = argv[2];
 146
 147         log_set_target(LOG_TARGET_SAFE);
 148         log_parse_environment();
 149         log_open();
 150
 151         umask(0022);
 152
 153         r = parse_proc_cmdline(parse_proc_cmdline_item);
 154         if (r < 0)
 155                 log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");
 156
 157         if (arg_debug_shell) {
 158                 r = strv_extend(&arg_wants, "debug-shell.service");
 159                 if (r < 0) {
 160                         r = log_oom();
 161                         goto finish;
 162                 }
 163         }
 164
 165         r = generate_mask_symlinks();
 166
 167         q = generate_wants_symlinks();
 168         if (q < 0)
 169                 r = q;
 170
 171 finish:
 172         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 173
 174 }