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 "alloc-util.h"
  23 #include "mkdir.h"
  24 #include "parse-util.h"
  25 #include "proc-cmdline.h"
  26 #include "string-util.h"
  27 #include "strv.h"
  28 #include "unit-name.h"
  29 #include "util.h"
  30
  31 static const char *arg_dest = "/tmp";
  32 static char **arg_mask = NULL;
  33 static char **arg_wants = NULL;
  34 static bool arg_debug_shell = false;
  35
  36 static int parse_proc_cmdline_item(const char *key, const char *value) {
  37         int r;
  38
  39         assert(key);
  40
  41         if (streq(key, "systemd.mask")) {
  42
  43                 if (!value)
  44                         log_error("Missing argument for systemd.mask= kernel command line parameter.");
  45                 else {
  46                         char *n;
  47
  48                         r = unit_name_mangle(value, UNIT_NAME_NOGLOB, &n);
  49                         if (r < 0)
  50                                 return log_error_errno(r, "Failed to glob unit name: %m");
  51
  52                         r = strv_consume(&arg_mask, n);
  53                         if (r < 0)
  54                                 return log_oom();
  55                 }
  56
  57         } else if (streq(key, "systemd.wants")) {
  58
  59                 if (!value)
  60                         log_error("Missing argument for systemd.want= kernel command line parameter.");
  61                 else {
  62                         char *n;
  63
  64                         r = unit_name_mangle(value, UNIT_NAME_NOGLOB, &n);
  65                         if (r < 0)
  66                                 return log_error_errno(r, "Failed to glob unit name: %m");
  67
  68                         r = strv_consume(&arg_wants, n);
  69                         if (r < 0)
  70                                 return log_oom();
  71                 }
  72
  73         } else if (streq(key, "systemd.debug-shell")) {
  74
  75                 if (value) {
  76                         r = parse_boolean(value);
  77                         if (r < 0)
  78                                 log_error("Failed to parse systemd.debug-shell= argument '%s', ignoring.", value);
  79                         else
  80                                 arg_debug_shell = r;
  81                 } else
  82                         arg_debug_shell = true;
  83         }
  84
  85         return 0;
  86 }
  87
  88 static int generate_mask_symlinks(void) {
  89         char **u;
  90         int r = 0;
  91
  92         if (strv_isempty(arg_mask))
  93                 return 0;
  94
  95         STRV_FOREACH(u, arg_mask) {
  96                 _cleanup_free_ char *p = NULL;
  97
  98                 p = strjoin(arg_dest, "/", *u, NULL);
  99                 if (!p)
 100                         return log_oom();
 101
 102                 if (symlink("/dev/null", p) < 0)
 103                         r = log_error_errno(errno,
 104                                             "Failed to create mask symlink %s: %m",
 105                                             p);
 106         }
 107
 108         return r;
 109 }
 110
 111 static int generate_wants_symlinks(void) {
 112         char **u;
 113         int r = 0;
 114
 115         if (strv_isempty(arg_wants))
 116                 return 0;
 117
 118         STRV_FOREACH(u, arg_wants) {
 119                 _cleanup_free_ char *p = NULL, *f = NULL;
 120
 121                 p = strjoin(arg_dest, "/default.target.wants/", *u, NULL);
 122                 if (!p)
 123                         return log_oom();
 124
 125                 f = strappend(SYSTEM_DATA_UNIT_PATH "/", *u);
 126                 if (!f)
 127                         return log_oom();
 128
 129                 mkdir_parents_label(p, 0755);
 130
 131                 if (symlink(f, p) < 0)
 132                         r = log_error_errno(errno,
 133                                             "Failed to create wants symlink %s: %m",
 134                                             p);
 135         }
 136
 137         return r;
 138 }
 139
 140 int main(int argc, char *argv[]) {
 141         int r, q;
 142
 143         if (argc > 1 && argc != 4) {
 144                 log_error("This program takes three or no arguments.");
 145                 return EXIT_FAILURE;
 146         }
 147
 148         if (argc > 1)
 149                 arg_dest = argv[2];
 150
 151         log_set_target(LOG_TARGET_SAFE);
 152         log_parse_environment();
 153         log_open();
 154
 155         umask(0022);
 156
 157         r = parse_proc_cmdline(parse_proc_cmdline_item);
 158         if (r < 0)
 159                 log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");
 160
 161         if (arg_debug_shell) {
 162                 r = strv_extend(&arg_wants, "debug-shell.service");
 163                 if (r < 0) {
 164                         r = log_oom();
 165                         goto finish;
 166                 }
 167         }
 168
 169         r = generate_mask_symlinks();
 170
 171         q = generate_wants_symlinks();
 172         if (q < 0)
 173                 r = q;
 174
 175 finish:
 176         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 177
 178 }