aboutsummaryrefslogtreecommitdiff
path: root/src/util/gnunet-uri.c
blob: 75e70d2b754cf66b9930891ac346971ba8ae4418 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
/*
     This file is part of GNUnet.
     Copyright (C) 2012 GNUnet e.V.

     GNUnet is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published
     by the Free Software Foundation; either version 3, or (at your
     option) any later version.

     GNUnet 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
     General Public License for more details.

     You should have received a copy of the GNU General Public License
     along with GNUnet; see the file COPYING.  If not, write to the
     Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     Boston, MA 02110-1301, USA.
*/

/**
 * @file util/gnunet-uri.c
 * @brief tool to dispatch URIs to the appropriate GNUnet helper process
 * @author Christian Grothoff
 */
#include "platform.h"
#include "gnunet_util_lib.h"

/**
 * Handler exit code
 */
static long unsigned int exit_code = 1;

/**
 * Helper process we started.
 */
static struct GNUNET_OS_Process *p;

/**
 * Pipe used to communicate shutdown via signal.
 */
static struct GNUNET_DISK_PipeHandle *sigpipe;


/**
 * Task triggered whenever we receive a SIGCHLD (child
 * process died) or when user presses CTRL-C.
 *
 * @param cls closure, NULL
 */
static void
maint_child_death (void *cls)
{
  enum GNUNET_OS_ProcessStatusType type;
  if ( (GNUNET_OK !=
	GNUNET_OS_process_status (p, &type, &exit_code)) ||
       (type != GNUNET_OS_PROCESS_EXITED) )
    GNUNET_break (0 == GNUNET_OS_process_kill (p, GNUNET_TERM_SIG));
  GNUNET_OS_process_destroy (p);
}


/**
 * Main function that will be run by the scheduler.
 *
 * @param cls closure
 * @param args remaining command-line arguments
 * @param cfgfile name of the configuration file used (for saving, can be NULL!)
 * @param cfg configuration
 */
static void
run (void *cls, char *const *args, const char *cfgfile,
     const struct GNUNET_CONFIGURATION_Handle *cfg)
{
  const char *uri;
  const char *slash;
  char *subsystem;
  char *program;
  struct GNUNET_SCHEDULER_Task * rt;

  if (NULL == (uri = args[0]))
  {
    fprintf (stderr, _("No URI specified on command line\n"));
    return;
  }
  if (0 != strncasecmp ("gnunet://", uri, strlen ("gnunet://")))
  {
    fprintf (stderr, _("Invalid URI: does not start with `%s'\n"),
	     "gnunet://");
    return;
  }
  uri += strlen ("gnunet://");
  if (NULL == (slash = strchr (uri, '/')))
  {
    fprintf (stderr, _("Invalid URI: fails to specify subsystem\n"));
    return;
  }
  subsystem = GNUNET_strndup (uri, slash - uri);
  if (GNUNET_OK !=
      GNUNET_CONFIGURATION_get_value_string (cfg,
					     "uri",
					     subsystem,
					     &program))
  {
    fprintf (stderr, _("No handler known for subsystem `%s'\n"), subsystem);
    GNUNET_free (subsystem);
    return;
  }
  GNUNET_free (subsystem);
  rt = GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
				       GNUNET_DISK_pipe_handle (sigpipe,
								GNUNET_DISK_PIPE_END_READ),
				       &maint_child_death, NULL);
  p = GNUNET_OS_start_process (GNUNET_NO, 0,
			       NULL, NULL, NULL,
			       program,
			       program,
			       args[0],
			       NULL);
  GNUNET_free (program);
  if (NULL == p)
    GNUNET_SCHEDULER_cancel (rt);
}


/**
 * Signal handler called for SIGCHLD.  Triggers the
 * respective handler by writing to the trigger pipe.
 */
static void
sighandler_child_death ()
{
  static char c;
  int old_errno = errno;	/* back-up errno */

  GNUNET_break (1 ==
		GNUNET_DISK_file_write (GNUNET_DISK_pipe_handle
					(sigpipe, GNUNET_DISK_PIPE_END_WRITE),
					&c, sizeof (c)));
  errno = old_errno;		/* restore errno */
}


/**
 * The main function to handle gnunet://-URIs.
 *
 * @param argc number of arguments from the command line
 * @param argv command line arguments
 * @return 0 ok, 1 on error
 */
int
main (int argc, char *const *argv)
{
  static const struct GNUNET_GETOPT_CommandLineOption options[] = {
    GNUNET_GETOPT_OPTION_END
  };
  struct GNUNET_SIGNAL_Context *shc_chld;
  int ret;

  if (GNUNET_OK != GNUNET_STRINGS_get_utf8_args (argc, argv, &argc, &argv))
    return 2;
  sigpipe = GNUNET_DISK_pipe (GNUNET_NO, GNUNET_NO, GNUNET_NO, GNUNET_NO);
  GNUNET_assert (sigpipe != NULL);
  shc_chld =
    GNUNET_SIGNAL_handler_install (GNUNET_SIGCHLD, &sighandler_child_death);
  ret = GNUNET_PROGRAM_run (argc, argv, "gnunet-uri URI",
			    gettext_noop ("Perform default-actions for GNUnet URIs"),
			    options, &run, NULL);
  GNUNET_SIGNAL_handler_uninstall (shc_chld);
  shc_chld = NULL;
  GNUNET_DISK_pipe_close (sigpipe);
  sigpipe = NULL;
  GNUNET_free ((void *) argv);
  return ((GNUNET_OK == ret) && (0 == exit_code)) ? 0 : 1;
}

/* end of gnunet-uri.c */