gnunet-qr.c File Reference

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

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Macros
#define	LOG(fmt, ...)
	Macro to handle verbosity when printing messages. More...

Functions
static void	shutdown_program (void *cls)
	Executed when program is terminating. More...
static void	wait_child (void *cls, enum GNUNET_OS_ProcessStatusType type, long unsigned int code)
	Callback executed when the child process terminates. More...
static void	handle_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 a QR code symbol from proc. More...
static char *	run_zbar (void)
	Run the zbar QR code parser. More...
static void	run (void *cls, char *const *args, const char *cfgfile, const struct GNUNET_CONFIGURATION_Handle *cfg)
	Main function executed by the scheduler. More...
int	main (int argc, char *const *argv)

Variables
static int	exit_code = 0
	Global exit code. More...
static char *	device = NULL
	Video device to capture from. More...
static unsigned int	verbosity = 0
	Requested verbosity. More...
struct GNUNET_OS_Process *	childproc = NULL
	Child process handle. More...
static struct GNUNET_ChildWaitHandle *	waitchildproc = NULL
	Child process handle for waiting. 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:

  do                                                            \
  {                                                             \
    if (0 < verbosity)                                          \
    {                                                           \
      GNUNET_log (GNUNET_ERROR_TYPE_INFO, fmt, ##__VA_ARGS__);  \
      if (verbosity > 1)                                        \
      {                                                         \
        fprintf (stdout, fmt, ##__VA_ARGS__);                   \
      }                                                         \
    }                                                           \
  }                                                             \
  while (0)

Macro to handle verbosity when printing messages.

Definition at line 79 of file gnunet-qr.c.

Function Documentation

shutdown_program()

static void shutdown_program ( void *  cls )

static

Executed when program is terminating.

Definition at line 97 of file gnunet-qr.c.

{
  if (NULL != waitchildproc)
  {
    GNUNET_wait_child_cancel (waitchildproc);
  }
  if (NULL != childproc)
  {
    /* A bit brutal, but this process is terminating so we're out of time */
    GNUNET_OS_process_kill (childproc, SIGKILL);
  }
}

References childproc, GNUNET_OS_process_kill(), GNUNET_wait_child_cancel(), and waitchildproc.

Referenced by run().

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wait_child()

static void wait_child ( void *  cls, enum GNUNET_OS_ProcessStatusType  type, long unsigned int  code  )

static

Callback executed when the child process terminates.

Parameters

cls	closure
type	status of the child process
code	the exit code of the child process

Definition at line 118 of file gnunet-qr.c.

{
  GNUNET_OS_process_destroy (childproc);
  childproc = NULL;
  waitchildproc = NULL;
 
  char *uri = cls;
 
  if (0 != exit_code)
  {
    fprintf (stdout, _("Failed to add URI %s\n"), uri);
  }
  else
  {
    fprintf (stdout, _("Added URI %s\n"), uri);
  }
 
  GNUNET_free (uri);
 
  GNUNET_SCHEDULER_shutdown ();
}

References _, childproc, exit_code, GNUNET_free, GNUNET_OS_process_destroy(), GNUNET_SCHEDULER_shutdown(), uri, and waitchildproc.

Referenced by handle_uri().

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handle_uri()

static void handle_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 in use
cfg	the configuration in use

Definition at line 151 of file gnunet-qr.c.

{
  const char *cursor = uri;
 
  if (0 != strncasecmp ("gnunet://", uri, strlen ("gnunet://")))
  {
    fprintf (stderr,
             _("Invalid URI: does not start with `gnunet://'\n"));
    exit_code = 1;
    return;
  }
 
  cursor += strlen ("gnunet://");
 
  const char *slash = strchr (cursor, '/');
  if (NULL == slash)
  {
    fprintf (stderr, _("Invalid URI: fails to specify a subsystem\n"));
    exit_code = 1;
    return;
  }
 
  char *subsystem = GNUNET_strndup (cursor, slash - cursor);
  char *program = NULL;
 
  if (GNUNET_OK !=
      GNUNET_CONFIGURATION_get_value_string (cfg, "uri", subsystem, &program))
  {
    fprintf (stderr, _("No known handler for subsystem `%s'\n"), subsystem);
    GNUNET_free (subsystem);
    exit_code = 1;
    return;
  }
 
  GNUNET_free (subsystem);
 
  char **childargv = NULL;
  unsigned int childargc = 0;
 
  for (const char *token=strtok (program, " ");
       NULL!=token;
       token=strtok(NULL, " "))
  {
    GNUNET_array_append (childargv, childargc, GNUNET_strdup (token));
  }
  GNUNET_array_append (childargv, childargc, GNUNET_strdup (uri));
  GNUNET_array_append (childargv, childargc, NULL);
 
  childproc = GNUNET_OS_start_process_vap (GNUNET_OS_INHERIT_STD_ALL,
                                           NULL,
                                           NULL,
                                           NULL,
                                           childargv[0],
                                           childargv);
  for (size_t i=0; i<childargc-1; ++i)
  {
    GNUNET_free (childargv[i]);
  }
 
  GNUNET_array_grow (childargv, childargc, 0);
 
  if (NULL == childproc)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                _("Unable to start child process `%s'\n"),
                program);
    GNUNET_free (program);
    exit_code = 1;
    return;
  }
 
  waitchildproc = GNUNET_wait_child (childproc, &wait_child, (void *)uri);
}

References _, cfg, childproc, exit_code, GNUNET_array_append, GNUNET_array_grow, GNUNET_CONFIGURATION_get_value_string(), GNUNET_ERROR_TYPE_ERROR, GNUNET_free, GNUNET_log, GNUNET_OK, GNUNET_OS_INHERIT_STD_ALL, GNUNET_OS_start_process_vap(), GNUNET_strdup, GNUNET_strndup, GNUNET_wait_child(), subsystem, uri, wait_child(), and waitchildproc.

Referenced by run().

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get_symbol()

static const zbar_symbol_t* get_symbol ( zbar_processor_t *  proc )

static

Obtain a QR code symbol from proc.

Parameters

proc	the zbar processor to use

Returns

NULL on error

Definition at line 235 of file gnunet-qr.c.

{
  if (0 != zbar_processor_parse_config (proc, "enable"))
  {
    GNUNET_break (0);
    return NULL;
  }
 
  int r = zbar_processor_init (proc, device, 1);
  if (0 != r)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                _("Failed to open device: `%s': %d\n"),
                device,
                r);
    return NULL;
  }
 
  r = zbar_processor_set_visible (proc, 1);
  r += zbar_processor_set_active (proc, 1);
  if (0 != r)
  {
    GNUNET_break (0);
    return NULL;
  }
 
  LOG (_("Capturing...\n"));
 
  int n = zbar_process_one (proc, -1);
 
  zbar_processor_set_active (proc, 0);
  zbar_processor_set_visible (proc, 0);
 
  if (-1 == n)
  {
    LOG (_("No captured images\n"));
    return NULL;
  }
 
  LOG(_("Got %d images\n"), n);
 
  const zbar_symbol_set_t *symbols = zbar_processor_get_results (proc);
  if (NULL == symbols)
  {
    GNUNET_break (0);
    return NULL;
  }
 
  return zbar_symbol_set_first_symbol (symbols);
}

References _, device, GNUNET_break, GNUNET_ERROR_TYPE_ERROR, GNUNET_log, LOG, and GNUNET_ChildWaitHandle::proc.

Referenced by run_zbar().

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run_zbar()

static char* run_zbar ( void  )

static

Run the zbar QR code parser.

Returns

NULL on error

Definition at line 292 of file gnunet-qr.c.

{
  zbar_processor_t *proc = zbar_processor_create (1);
  if (NULL == proc)
  {
    GNUNET_break (0);
    return NULL;
  }
 
  if (NULL == device)
  {
    device = GNUNET_strdup ("/dev/video0");
  }
 
  const zbar_symbol_t *symbol = get_symbol (proc);
  if (NULL == symbol)
  {
    zbar_processor_destroy (proc);
    return NULL;
  }
 
  const char *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);
 
  char *copy = GNUNET_strdup (data);
 
  zbar_processor_destroy (proc);
  GNUNET_free (device);
 
  return copy;
}

References _, data, device, get_symbol(), GNUNET_break, GNUNET_free, GNUNET_strdup, LOG, and GNUNET_ChildWaitHandle::proc.

Referenced by run().

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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 executed by the scheduler.

Parameters

cls	closure
args	remaining command line arguments
cfgfile	name of the configuration file being used
cfg	the used configuration

Definition at line 524 of file gnunet-qr.c.

{
  char *data = NULL;
 
  GNUNET_SCHEDULER_add_shutdown (&shutdown_program, NULL);
 
#if HAVE_PNG
  if (NULL != pngfilename)
  {
    data = run_png_reader ();
  }
  else
#endif
  {
    data = run_zbar ();
  }
 
  if (NULL == data)
  {
    LOG (_("No data found\n"));
    exit_code = 1;
    GNUNET_SCHEDULER_shutdown ();
    return;
  }
 
  handle_uri (cls, data, cfgfile, cfg);
 
  if (0 != exit_code)
  {
    fprintf (stdout, _("Failed to add URI %s\n"), data);
    GNUNET_free (data);
    GNUNET_SCHEDULER_shutdown ();
    return;
  }
 
  LOG (_("Dispatching the URI\n"));
}

References _, cfg, data, exit_code, GNUNET_free, GNUNET_SCHEDULER_add_shutdown(), GNUNET_SCHEDULER_shutdown(), handle_uri(), LOG, run_zbar(), and shutdown_program().

Referenced by main().

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main()

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

Definition at line 566 of file gnunet-qr.c.

{
  struct GNUNET_GETOPT_CommandLineOption options[] = {
    GNUNET_GETOPT_option_string (
      'd',
      "device",
      "DEVICE",
      gettext_noop ("use the video device DEVICE (defaults to /dev/video0)"),
      &device),
#if HAVE_PNG
    GNUNET_GETOPT_option_string (
      'f',
      "file",
      "FILE",
      gettext_noop ("read from the PNG-encoded file FILE"),
      &pngfilename),
#endif
    GNUNET_GETOPT_option_verbose (&verbosity),
    GNUNET_GETOPT_OPTION_END,
  };
 
  enum GNUNET_GenericReturnValue ret =
    GNUNET_PROGRAM_run (argc,
                        argv,
                        "gnunet-qr",
                        gettext_noop ("Scan a QR code and import the URI read"),
                        options,
                        &run,
                        NULL);
 
  return ((GNUNET_OK == ret) && (0 == exit_code)) ? 0 : 1;
}

References device, exit_code, gettext_noop, GNUNET_GETOPT_OPTION_END, GNUNET_GETOPT_option_string(), GNUNET_GETOPT_option_verbose(), GNUNET_OK, GNUNET_PROGRAM_run(), options, ret, run(), and verbosity.

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Variable Documentation

exit_code

int exit_code = 0

static

Global exit code.

Set to non-zero if an error occurs after the scheduler has started.

Definition at line 43 of file gnunet-qr.c.

Referenced by child_completed_callback(), handle_uri(), main(), maint_child_death(), run(), and wait_child().

device

char* device = NULL

static

Video device to capture from.

Used by default if PNG support is disabled or no PNG file is specified. Defaults to /dev/video0.

Definition at line 50 of file gnunet-qr.c.

Referenced by get_symbol(), main(), and run_zbar().

verbosity

unsigned int verbosity = 0

static

Requested verbosity.

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

Referenced by main().

childproc

struct GNUNET_OS_Process* childproc = NULL

Child process handle.

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

Referenced by handle_uri(), shutdown_program(), and wait_child().

waitchildproc

struct GNUNET_ChildWaitHandle* waitchildproc = NULL

static

Child process handle for waiting.

Definition at line 74 of file gnunet-qr.c.

Referenced by handle_uri(), shutdown_program(), and wait_child().