gnunet-qr.c File Reference

#include <stdio.h>
#include <zbar.h>
#include <stdbool.h>
#include "platform.h"
#include "gnunet_util_lib.h"

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Macros
#define	LOG(fmt, ...)

Functions
static void	maint_child_death (void *cls)
	Task triggered whenever we receive a SIGCHLD (child process died) or when user presses CTRL-C. More...
static void	sighandler_chld ()
	Signal handler called for signals that causes us to wait for the child process. More...
static void	gnunet_uri (void *cls, const char *uri, const char *cfgfile, const struct GNUNET_CONFIGURATION_Handle *cfg)
	Dispatch URIs to the appropriate GNUnet helper process. More...
static const zbar_symbol_t *	get_symbol (zbar_processor_t *proc)
	Obtain QR code 'symbol' from proc. More...
static char *	run_zbar ()
	Run zbar QR code parser. More...
static void	run (void *cls, char *const *args, const char *cfgfile, const struct GNUNET_CONFIGURATION_Handle *cfg)
	Main function that will be run by the scheduler. More...
int	main (int argc, char *const *argv)

Variables
static char *	device = "/dev/video0"
	Video device to capture from. More...
static unsigned int	verbose
	–verbose option More...
static int	silent = false
	–silent option More...
static long unsigned int	exit_code = 1
	Handler exit code. More...
static struct GNUNET_OS_Process *	p
	Helper process we started. More...
static struct GNUNET_SIGNAL_Context *	shc_chld
	Child signal handler. More...
static struct GNUNET_DISK_PipeHandle *	sigpipe
	Pipe used to communicate child death via signal. More...
static pid_t	my_pid
	Process ID of this process at the time we installed the various signal handlers. More...

Detailed Description

Author

Hartmut Goebel (original implementation)

Martin Schanzenbach (integrate gnunet-uri)

Christian Grothoff (error handling)

Definition in file gnunet-qr.c.

Macro Definition Documentation

LOG

#define LOG	(		fmt,
			...
	)

Value:

if (verbose) \
    printf (fmt, ## __VA_ARGS__)

Definition at line 32 of file gnunet-qr.c.

Referenced by get_symbol(), and run_zbar().

Function Documentation

maint_child_death()

static void maint_child_death ( void *  cls )

static

Task triggered whenever we receive a SIGCHLD (child process died) or when user presses CTRL-C.

Parameters

cls	closure, NULL

Definition at line 84 of file gnunet-qr.c.

References exit_code, GNUNET_break, GNUNET_DISK_pipe_close(), GNUNET_OK, GNUNET_OS_process_destroy(), GNUNET_OS_PROCESS_EXITED, GNUNET_OS_process_kill(), GNUNET_OS_process_status(), GNUNET_SIGNAL_handler_uninstall(), GNUNET_TERM_SIG, and type.

Referenced by gnunet_uri().

{
  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_SIGNAL_handler_uninstall (shc_chld);
  shc_chld = NULL;
  if (NULL != sigpipe)
  {
    GNUNET_DISK_pipe_close (sigpipe);
    sigpipe = NULL;
  }
  GNUNET_OS_process_destroy (p);
}

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sighandler_chld()

static void sighandler_chld ( )

static

Signal handler called for signals that causes us to wait for the child process.

Definition at line 106 of file gnunet-qr.c.

References GNUNET_DISK_file_write(), GNUNET_DISK_PIPE_END_WRITE, GNUNET_DISK_pipe_handle(), and my_pid.

Referenced by gnunet_uri().

{
  static char c;
  int old_errno = errno;        /* backup errno */

  if (getpid () != my_pid)
    _exit (1);                   /* we have fork'ed since the signal handler was created,
                                  * ignore the signal, see https://gnunet.org/vfork discussion */
  GNUNET_DISK_file_write (GNUNET_DISK_pipe_handle
                            (sigpipe, GNUNET_DISK_PIPE_END_WRITE),
                          &c, sizeof(c));
  errno = old_errno;
}

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gnunet_uri()

static void gnunet_uri ( void *  cls, const char *  uri, const char *  cfgfile, const struct GNUNET_CONFIGURATION_Handle *  cfg  )

static

Dispatch URIs to the appropriate GNUnet helper process.

Parameters

cls	closure
uri	uri to dispatch
cfgfile	name of the configuration file used (for saving, can be NULL!)
cfg	configuration

Definition at line 130 of file gnunet-qr.c.

References _, GNUNET_array_append, GNUNET_array_grow, GNUNET_assert, GNUNET_CONFIGURATION_get_value_string(), GNUNET_DISK_pipe(), GNUNET_DISK_PIPE_END_READ, GNUNET_DISK_pipe_handle(), GNUNET_free, GNUNET_NO, GNUNET_OK, GNUNET_OS_INHERIT_STD_ALL, GNUNET_OS_start_process_vap(), GNUNET_SCHEDULER_add_read_file(), GNUNET_SCHEDULER_cancel(), GNUNET_SIGNAL_handler_install(), GNUNET_strdup, GNUNET_strndup, GNUNET_TIME_UNIT_FOREVER_REL, maint_child_death(), my_pid, sighandler_chld(), subsystem, and uri.

Referenced by run().

{
  const char *orig_uri;
  const char *slash;
  char *subsystem;
  char *program;
  struct GNUNET_SCHEDULER_Task *rt;

  orig_uri = uri;
  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);
  sigpipe = GNUNET_DISK_pipe (GNUNET_NO,
                              GNUNET_NO,
                              GNUNET_NO,
                              GNUNET_NO);
  GNUNET_assert (NULL != sigpipe);
  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);
  my_pid = getpid ();
  shc_chld = GNUNET_SIGNAL_handler_install (SIGCHLD,
                                            &sighandler_chld);

  {
    char **argv = NULL;
    unsigned int argc = 0;
    char *u = GNUNET_strdup (program);

    for (const char *tok = strtok (u, " ");
         NULL != tok;
         tok = strtok (NULL, " "))
      GNUNET_array_append (argv,
                           argc,
                           GNUNET_strdup (tok));
    GNUNET_array_append (argv,
                         argc,
                         GNUNET_strdup (orig_uri));
    GNUNET_array_append (argv,
                         argc,
                         NULL);
    p = GNUNET_OS_start_process_vap (GNUNET_NO,
                                     GNUNET_OS_INHERIT_STD_ALL,
                                     NULL,
                                     NULL,
                                     NULL,
                                     argv[0],
                                     argv);
    for (unsigned int i = 0; i<argc - 1; i++)
      GNUNET_free (argv[i]);
    GNUNET_array_grow (argv,
                       argc,
                       0);
    GNUNET_free (u);
  }
  if (NULL == p)
    GNUNET_SCHEDULER_cancel (rt);
  GNUNET_free (program);
}

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get_symbol()

static const zbar_symbol_t* get_symbol ( zbar_processor_t *  proc )

static

Obtain QR code 'symbol' from proc.

Parameters

proc	zbar processor to use

Returns

NULL on error

Definition at line 222 of file gnunet-qr.c.

References device, GNUNET_break, GNUNET_ERROR_TYPE_ERROR, GNUNET_log, and LOG.

Referenced by run_zbar().

{
  const zbar_symbol_set_t *symbols;
  int rc;
  int n;

  if (0 != zbar_processor_parse_config (proc, "enable"))
  {
    GNUNET_break (0);
    return NULL;
  }

  /* initialize the Processor */
  if (0 != (rc = zbar_processor_init (proc, device, 1)))
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                "Failed to open device `%s': %d\n",
                device,
                rc);
    return NULL;
  }

  /* enable the preview window */
  if ((0 != (rc = zbar_processor_set_visible (proc, 1))) ||
      (0 != (rc = zbar_processor_set_active (proc, 1))))
  {
    GNUNET_break (0);
    return NULL;
  }

  /* read at least one barcode (or until window closed) */
  LOG ("Capturing\n");
  n = zbar_process_one (proc, -1);

  /* hide the preview window */
  (void) zbar_processor_set_active (proc, 0);
  (void) zbar_processor_set_visible (proc, 0);
  if (-1 == n)
    return NULL; /* likely user closed the window */
  LOG ("Got %i images\n", n);
  /* extract results */
  symbols = zbar_processor_get_results (proc);
  if (NULL == symbols)
  {
    GNUNET_break (0);
    return NULL;
  }
  return zbar_symbol_set_first_symbol (symbols);
}

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run_zbar()

static char* run_zbar ( )

static

Run zbar QR code parser.

Returns

NULL on error, otherwise the URI that we found

Definition at line 279 of file gnunet-qr.c.

References data, get_symbol(), GNUNET_break, GNUNET_strdup, LOG, and ret.

Referenced by run().

{
  zbar_processor_t *proc;
  const char *data;
  char *ret;
  const zbar_symbol_t *symbol;

  /* configure the Processor */
  proc = zbar_processor_create (1);
  if (NULL == proc)
  {
    GNUNET_break (0);
    return NULL;
  }

  symbol = get_symbol (proc);
  if (NULL == symbol)
  {
    zbar_processor_destroy (proc);
    return NULL;
  }
  data = zbar_symbol_get_data (symbol);
  if (NULL == data)
  {
    GNUNET_break (0);
    zbar_processor_destroy (proc);
    return NULL;
  }
  LOG ("Found %s \"%s\"\n",
       zbar_get_symbol_name (zbar_symbol_get_type (symbol)),
       data);
  ret = GNUNET_strdup (data);
  /* clean up */
  zbar_processor_destroy (proc);
  return ret;
}

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run()

static void run ( void *  cls, char *const *  args, const char *  cfgfile, const struct GNUNET_CONFIGURATION_Handle *  cfg  )

static

Main function that will be run by the scheduler.

Parameters

cls	closure
args	remaining command-line arguments
cfgfile	name of the configuration file used (for saving, can be NULL!)
cfg	configuration

Definition at line 326 of file gnunet-qr.c.

References data, exit_code, GNUNET_free, gnunet_uri(), and run_zbar().

Referenced by main().

{
  char *data;

  data = run_zbar ();
  if (NULL == data)
    return;
  gnunet_uri (cls, data, cfgfile, cfg);
  if (exit_code != 0)
  {
    printf ("Failed to add URI %s\n", data);
  }
  else
  {
    printf ("Added URI %s\n", data);
  }
  GNUNET_free (data);
};

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main()

int main	(	int	argc,
		char *const *	argv
	)

Definition at line 350 of file gnunet-qr.c.

References device, exit_code, gettext_noop, GNUNET_GETOPT_OPTION_END, GNUNET_GETOPT_option_flag(), GNUNET_GETOPT_option_string(), GNUNET_GETOPT_option_verbose(), GNUNET_OK, GNUNET_PROGRAM_run(), ret, run(), silent, and verbose.

{
  int ret;
  struct GNUNET_GETOPT_CommandLineOption options[] = {
    GNUNET_GETOPT_option_string (
      'd',
      "device",
      "DEVICE",
      gettext_noop ("use video-device DEVICE (default: /dev/video0"),
      &device),
    GNUNET_GETOPT_option_verbose (&verbose),
    GNUNET_GETOPT_option_flag ('s',
                               "silent",
                               gettext_noop ("do not show preview windows"),
                               &silent),
    GNUNET_GETOPT_OPTION_END
  };

  ret = GNUNET_PROGRAM_run (
    argc,
    argv,
    "gnunet-qr",
    gettext_noop (
      "Scan a QR code using a video device and import the uri read"),
    options,
    &run,
    NULL);
  return ((GNUNET_OK == ret) && (0 == exit_code)) ? 0 : 1;
}

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Variable Documentation

device

char* device = "/dev/video0"

static

Video device to capture from.

Sane default for GNU/Linux systems.

Definition at line 39 of file gnunet-qr.c.

Referenced by get_symbol(), and main().

verbose

unsigned int verbose

static

–verbose option

Definition at line 44 of file gnunet-qr.c.

Referenced by main().

silent

int silent = false

static

–silent option

Definition at line 49 of file gnunet-qr.c.

Referenced by main().

exit_code

long unsigned int exit_code = 1

static

Handler exit code.

Definition at line 54 of file gnunet-qr.c.

Referenced by main(), maint_child_death(), and run().

p

struct GNUNET_OS_Process* p

static

Helper process we started.

Definition at line 59 of file gnunet-qr.c.

Referenced by _make_continuous_arg_copy(), access_handler_callback(), adjust(), age_values(), ats_performance_info_cb(), block_proc(), block_reader(), check_priority(), comm_connect_cb(), comm_disconnect_cb(), comm_schedule_send(), compute_scalar_product(), compute_service_response(), context_state_callback(), create_loc_uri(), CustomPeerMap_put(), CustomPeerMap_remove_peer(), display_bar(), display_request(), dns_result_parser(), do_connect_peers(), do_shutdown(), do_stop_task(), download_stop_task(), dump_buffer(), encode_cont(), enforce_add_address(), enforce_del_address(), enforce_start_property(), enforce_start_request(), enforce_stop_preference(), enforce_stop_request(), enforce_stop_send(), evaluate(), find_timed_out(), format_help(), free_link_properties(), free_preference(), get_all_peers_iterator(), get_all_tunnels_iterator(), get_hello(), get_keywords_from_tokens(), get_longest_prefix(), get_path_from_GNUNET_PREFIX(), get_path_from_PATH(), get_pipeline(), get_preferences_cb(), getPRK(), GN_getopt_internal(), gns_resolve_name(), GNUNET_ATS_solver_generate_preferences_start(), GNUNET_ATS_TEST_logging_now(), GNUNET_CADET_open_port(), GNUNET_CONFIGURATION_create(), GNUNET_CONTAINER_meta_data_insert(), GNUNET_CONTAINER_multihashmap32_remove(), GNUNET_CONTAINER_multihashmap32_remove_all(), GNUNET_CONTAINER_multihashmap_remove(), GNUNET_CONTAINER_multihashmap_remove_all(), GNUNET_CONTAINER_multipeermap_remove(), GNUNET_CONTAINER_multipeermap_remove_all(), GNUNET_CONTAINER_multishortmap_remove(), GNUNET_CONTAINER_multishortmap_remove_all(), GNUNET_CONTAINER_multiuuidmap_remove(), GNUNET_CONTAINER_multiuuidmap_remove_all(), GNUNET_CRYPTO_ecc_ecdh(), GNUNET_CRYPTO_ecdh_ecdsa(), GNUNET_CRYPTO_ecdh_eddsa(), GNUNET_CRYPTO_ecdsa_ecdh(), GNUNET_CRYPTO_eddsa_ecdh(), GNUNET_CRYPTO_mpi_print_unsigned(), GNUNET_CRYPTO_paillier_create(), GNUNET_CRYPTO_zero_keys(), GNUNET_DISK_pipe_from_fd(), GNUNET_DNSPARSER_parse(), GNUNET_FS_publish_main_(), GNUNET_FS_publish_make_status_(), GNUNET_MY_exec_prepared(), GNUNET_OS_check_helper_binary(), GNUNET_OS_init(), GNUNET_SCHEDULER_cancel(), GNUNET_SECRETSHARING_share_read(), GNUNET_SECRETSHARING_share_write(), GNUNET_SERVER_add_handlers(), GNUNET_TRANSPORT_TESTING_connect_check(), GNUNET_TRANSPORT_TESTING_done(), GNUNET_TRANSPORT_TESTING_start_peer(), GSF_cadet_query_cancel(), handle_dns_request(), handle_index_start_failed(), handle_index_start_ok(), handle_ping(), handle_pong(), handle_show_path(), handle_signature_response(), hash_for_index_cb(), ibf_hashcode_from_key(), index_mq_error_handler(), libgnunet_plugin_transport_udp_init(), main(), modify_request(), notify_connect(), notify_disconnect(), oprelease_overlay_configure_topology(), opstart_overlay_configure_topology(), parse_definitions(), parse_pattern(), peer_info_cb(), peerinformation_cb(), process_result(), progress_cb(), progress_proc(), publish_content(), publish_kblocks(), publish_kblocks_cont(), publish_stop_task(), queue_ready_task(), recursive_dns_resolution(), regex_add(), regex_combine(), REGEX_INTERNAL_construct_nfa(), run(), run_process_and_wait(), search_stop_task(), set_feedback_task(), set_pref_task(), set_prop_task(), shutdown_task(), solver_bandwidth_changed_cb(), start_cb(), start_download(), start_publish(), stop_broadcast(), update_ping_data(), and update_pong_data().

shc_chld

struct GNUNET_SIGNAL_Context* shc_chld

static

Child signal handler.

Definition at line 64 of file gnunet-qr.c.

Referenced by main().

sigpipe

struct GNUNET_DISK_PipeHandle* sigpipe

static

Pipe used to communicate child death via signal.

Definition at line 69 of file gnunet-qr.c.

my_pid

pid_t my_pid

static

Process ID of this process at the time we installed the various signal handlers.

Definition at line 75 of file gnunet-qr.c.

Referenced by gnunet_uri(), and sighandler_chld().