gnunet-bcd.c

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/*
     This file is part of GNUnet.
     Copyright (C) 2013 GNUnet e.V.
 
     GNUnet is free software: you can redistribute it and/or modify it
     under the terms of the GNU Affero General Public License as published
     by the Free Software Foundation, either version 3 of the License,
     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
     Affero General Public License for more details.
 
     You should have received a copy of the GNU Affero General Public License
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
     SPDX-License-Identifier: AGPL3.0-or-later
 */
 
#include "platform.h"
#include <microhttpd.h>
#include "gnunet_util_lib.h"
#include "gnunet_identity_service.h"
#include "gnunet_mhd_compat.h"
 
struct StaticResource
{
  struct GNUNET_DISK_FileHandle *handle;
 
  uint64_t size;
 
  struct MHD_Response *response;
};
 
struct ParameterMap
{
  char *name;
 
  char *definition;
};
 
static struct MHD_Daemon *httpd = NULL;
 
static struct GNUNET_SCHEDULER_Task *httpd_task = NULL;
 
static struct StaticResource *index_simple = NULL;
 
static struct StaticResource *index_full = NULL;
 
static struct StaticResource *key_error = NULL;
 
static struct StaticResource *notfound_error = NULL;
 
static struct StaticResource *internal_error = NULL;
 
static struct StaticResource *forbidden_error = NULL;
 
static char *tex_file_simple = NULL;
 
static char *tex_file_full = NULL;
 
static char *tex_file_png = NULL;
 
static int continue_100 = 100;
 
static const struct ParameterMap pmap[] = {
  {"prefix", "prefix"},
  {"name", "name"},
  {"suffix", "suffix"},
  {"street", "street"},
  {"city", "city"},
  {"phone", "phone"},
  {"fax", "fax"},
  {"email", "email"},
  {"homepage", "homepage"},
  {"org", "organization"},
  {"department", "department"},
  {"subdepartment", "subdepartment"},
  {"jobtitle", "jobtitle"},
  {NULL, NULL},
};
 
static uint16_t port = 8888;
 
static void
do_shutdown (void *cls)
{
  /* We cheat a bit here: the file descriptor is implicitly closed by MHD, so
   calling `GNUNET_DISK_file_close' would generate a spurious warning message
   in the log. Since that function does nothing but close the descriptor and
   free the allocated memory, After destroying the response all that's left to
   do is call `GNUNET_free'. */
  if (NULL != index_simple)
  {
    MHD_destroy_response (index_simple->response);
    GNUNET_free (index_simple->handle);
    GNUNET_free (index_simple);
  }
  if (NULL != index_full)
  {
    MHD_destroy_response (index_full->response);
    GNUNET_free (index_full->handle);
    GNUNET_free (index_full);
  }
  if (NULL != key_error)
  {
    MHD_destroy_response (key_error->response);
    GNUNET_free (key_error->handle);
    GNUNET_free (key_error);
  }
  if (NULL != notfound_error)
  {
    MHD_destroy_response (notfound_error->response);
    GNUNET_free (notfound_error->handle);
    GNUNET_free (notfound_error);
  }
  if (NULL != internal_error)
  {
    MHD_destroy_response (internal_error->response);
    GNUNET_free (internal_error->handle);
    GNUNET_free (internal_error);
  }
  if (NULL != forbidden_error)
  {
    MHD_destroy_response (forbidden_error->response);
    GNUNET_free (forbidden_error->handle);
    GNUNET_free (forbidden_error);
  }
 
  if (NULL != httpd_task)
  {
    GNUNET_SCHEDULER_cancel (httpd_task);
  }
  if (NULL != httpd)
  {
    MHD_stop_daemon (httpd);
  }
}
 
static void
do_httpd (void *cls);
 
static void
run_httpd (void)
{
  fd_set rs;
  fd_set ws;
  fd_set es;
 
  struct GNUNET_NETWORK_FDSet *grs = GNUNET_NETWORK_fdset_create ();
  struct GNUNET_NETWORK_FDSet *gws = GNUNET_NETWORK_fdset_create ();
  struct GNUNET_NETWORK_FDSet *ges = GNUNET_NETWORK_fdset_create ();
 
  FD_ZERO (&rs);
  FD_ZERO (&ws);
  FD_ZERO (&es);
 
  int max = -1;
  GNUNET_assert (MHD_YES == MHD_get_fdset (httpd, &rs, &ws, &es, &max));
 
  unsigned MHD_LONG_LONG timeout = 0;
  struct GNUNET_TIME_Relative gtime = GNUNET_TIME_UNIT_FOREVER_REL;
  if (MHD_YES == MHD_get_timeout (httpd, &timeout))
  {
    gtime = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS,
                                           timeout);
  }
 
  GNUNET_NETWORK_fdset_copy_native (grs, &rs, max + 1);
  GNUNET_NETWORK_fdset_copy_native (gws, &ws, max + 1);
  GNUNET_NETWORK_fdset_copy_native (ges, &es, max + 1);
 
  httpd_task = GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_HIGH,
                                            gtime,
                                            grs,
                                            gws,
                                            &do_httpd,
                                            NULL);
  GNUNET_NETWORK_fdset_destroy (grs);
  GNUNET_NETWORK_fdset_destroy (gws);
  GNUNET_NETWORK_fdset_destroy (ges);
}
 
static void
do_httpd (void *cls)
{
  httpd_task = NULL;
  MHD_run (httpd);
  run_httpd ();
}
 
static MHD_RESULT
create_response (void *cls,
                 struct MHD_Connection *connection,
                 const char *url,
                 const char *method,
                 const char *version,
                 const char *upload_data,
                 size_t *upload_data_size,
                 void **ptr)
{
  (void) cls;
  (void) version;
  (void) upload_data;
  (void) upload_data_size;
 
  bool isget = (0 == strcmp (method, MHD_HTTP_METHOD_GET));
  bool ishead = (0 == strcmp (method, MHD_HTTP_METHOD_HEAD));
 
  if (!isget && !ishead)
  {
    return MHD_queue_response (connection,
                               MHD_HTTP_NOT_IMPLEMENTED,
                               forbidden_error->response);
  }
 
  if (ishead)
  {
    /* Dedicated branch in case we want to provide a different result for some
       reason (e.g. a non-web browser application using the web UI) */
    return MHD_queue_response (connection,
                               MHD_HTTP_OK,
                               index_simple->response);
  }
 
  /* Send a 100 CONTINUE response to tell clients that the result of the
     request might take some time */
  if (NULL == *ptr)
  {
    *ptr = &continue_100;
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Sending 100 CONTINUE\n");
    return MHD_YES;
  }
 
  if (0 == strcmp ("/", url))
  {
    return MHD_queue_response (connection,
                               MHD_HTTP_OK,
                               index_simple->response);
  }
 
  if (0 == strcmp ("/full", url))
  {
    return MHD_queue_response (connection,
                               MHD_HTTP_OK,
                               index_full->response);
  }
 
  bool isfull = (0 == strcmp ("/submit/full", url));
  bool issimple = (0 == strcmp ("/submit/simple", url));
 
  if (!isfull && !issimple)
  {
    return MHD_queue_response (connection,
                               MHD_HTTP_NOT_FOUND,
                               notfound_error->response);
  }
 
  const char *gpgfp = MHD_lookup_connection_value (connection,
                                                   MHD_GET_ARGUMENT_KIND,
                                                   "gpgfingerprint");
  const char *gnsnick = MHD_lookup_connection_value (connection,
                                                     MHD_GET_ARGUMENT_KIND,
                                                     "gnsnick");
  const char *gnskey = MHD_lookup_connection_value (connection,
                                                    MHD_GET_ARGUMENT_KIND,
                                                    "gnskey");
  const char *qrpng = MHD_lookup_connection_value (connection,
                                                   MHD_GET_ARGUMENT_KIND,
                                                   "gnspng");
 
  struct GNUNET_CRYPTO_PublicKey pk;
  if (NULL == gnskey
      || GNUNET_OK != GNUNET_CRYPTO_public_key_from_string (gnskey, &pk))
  {
    return MHD_queue_response (connection,
                               MHD_HTTP_BAD_REQUEST,
                               key_error->response);
  }
 
  char *tmpd = GNUNET_DISK_mkdtemp (gnskey);
  if (NULL == tmpd)
  {
    GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR, "mktemp", gnskey);
    return MHD_queue_response (connection,
                               MHD_HTTP_INTERNAL_SERVER_ERROR,
                               internal_error->response);
  }
 
  char *defpath = NULL;
  GNUNET_asprintf (&defpath, "%s%s%s", tmpd, DIR_SEPARATOR_STR, "def.tex");
 
  FILE *deffile = fopen (defpath, "w");
  if (NULL == deffile)
  {
    GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR, "open", defpath);
    GNUNET_free (defpath);
    GNUNET_DISK_directory_remove (tmpd);
    GNUNET_free (tmpd);
    return MHD_queue_response (connection,
                               MHD_HTTP_INTERNAL_SERVER_ERROR,
                               internal_error->response);
  }
 
  GNUNET_free (defpath);
 
  for (size_t i=0; NULL!=pmap[i].name; ++i)
  {
    const char *value = MHD_lookup_connection_value (connection,
                                                     MHD_GET_ARGUMENT_KIND,
                                                     pmap[i].name);
    fprintf (deffile,
             "\\def\\%s{%s}\n",
             pmap[i].definition,
             (NULL == value) ? "" : value);
  }
 
  if (NULL != gpgfp)
  {
    size_t len = strlen (gpgfp);
    char *line1 = GNUNET_strndup (gpgfp, len/2);
    char *line2 = GNUNET_strdup (&gpgfp[len/2]);
    fprintf (deffile,
             "\\def\\gpglineone{%s}\n\\def\\gpglinetwo{%s}\n",
             line1,
             line2);
    GNUNET_free (line1);
    GNUNET_free (line2);
  }
 
  fprintf (deffile,
           "\\def\\gns{%s/%s}\n",
           gnskey,
           (NULL == gnsnick) ? "" : gnsnick);
 
  fclose (deffile);
 
  char *command = NULL;
  GNUNET_asprintf (&command,
                   "cd %s; cp %s gns-bcd.tex; "
                   "pdflatex %s gns-bcd.tex >/dev/null 2>&1",
                   tmpd,
                   (isfull) ? tex_file_full :
                   ((NULL == qrpng) ? tex_file_simple : tex_file_png),
                   (NULL == qrpng) ? "" : "-shell-escape");
 
  int ret = system (command);
 
  GNUNET_free (command);
 
  if (WIFSIGNALED (ret) || 0 != WEXITSTATUS (ret))
  {
    GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR, "system", command);
  }
 
  GNUNET_asprintf (&defpath,
                   "%s%s%s",
                   tmpd,
                   DIR_SEPARATOR_STR,
                   (NULL == qrpng) ? "gns-bcd.pdf" : "gns-bcd.png");
 
  int pdf = open (defpath, O_RDONLY);
  if (-1 == pdf)
  {
    GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR, "open", defpath);
    GNUNET_free (defpath);
    GNUNET_DISK_directory_remove (tmpd);
    GNUNET_free (tmpd);
    return MHD_queue_response (connection,
                               MHD_HTTP_INTERNAL_SERVER_ERROR,
                               internal_error->response);
  }
 
  struct stat statret;
  GNUNET_break (0 == stat (defpath, &statret));
 
  GNUNET_free (defpath);
 
  struct MHD_Response *pdfrs =
    MHD_create_response_from_fd ((size_t) statret.st_size, pdf);
  if (NULL == pdfrs)
  {
    GNUNET_break (0);
    GNUNET_break (0 == close (pdf));
    GNUNET_DISK_directory_remove (tmpd);
    GNUNET_free (tmpd);
    return MHD_queue_response (connection,
                               MHD_HTTP_INTERNAL_SERVER_ERROR,
                               internal_error->response);
  }
 
  GNUNET_assert (MHD_NO != MHD_add_response_header (pdfrs,
                           MHD_HTTP_HEADER_CONTENT_TYPE,
                           (NULL == qrpng) ? "application/pdf" : "image/png"));
  GNUNET_assert (MHD_NO != MHD_add_response_header (pdfrs,
                           MHD_HTTP_HEADER_CONTENT_DISPOSITION,
                           (NULL == qrpng) ?
                           "attachment; filename=\"gns-business-card.pdf\"" :
                           "attachment; filename=\"gns-qr-code.png\""));
  MHD_RESULT r = MHD_queue_response (connection, MHD_HTTP_OK, pdfrs);
 
  MHD_destroy_response (pdfrs);
  GNUNET_DISK_directory_remove (tmpd);
  GNUNET_free (tmpd);
 
  return r;
}
 
static struct StaticResource *
open_static_resource (const char *name, const char *basedir)
{
  char *fullname = NULL;
  GNUNET_asprintf (&fullname, "%s%s%s", basedir, DIR_SEPARATOR_STR, name);
 
  struct GNUNET_DISK_FileHandle *f =
    GNUNET_DISK_file_open (fullname,
                           GNUNET_DISK_OPEN_READ,
                           GNUNET_DISK_PERM_NONE);
 
  GNUNET_free (fullname);
 
  if (NULL == f)
  {
    return NULL;
  }
 
  off_t size = 0;
  if (GNUNET_SYSERR == GNUNET_DISK_file_handle_size (f, &size))
  {
    GNUNET_DISK_file_close (f);
    return NULL;
  }
 
  struct MHD_Response *response = MHD_create_response_from_fd64 (size, f->fd);
 
  if (NULL == response)
  {
    GNUNET_DISK_file_close (f);
    return NULL;
  }
 
  struct StaticResource *res = GNUNET_new (struct StaticResource);
  res->handle = f;
  res->size = (uint64_t) size;
  res->response = response;
 
  return res;
}
 
static void
run (void *cls,
     char *const *args,
     const char *cfgfile,
     const struct GNUNET_CONFIGURATION_Handle *c)
{
  (void) cls;
  (void) args;
  (void) cfgfile;
 
  if (0 == port)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                _ ("Invalid port number %u\n"),
                port);
    GNUNET_SCHEDULER_shutdown ();
    return;
  }
 
  GNUNET_SCHEDULER_add_shutdown (&do_shutdown, NULL);
 
  char *datadir = GNUNET_OS_installation_get_path (GNUNET_OS_IPK_DATADIR);
  GNUNET_assert (NULL != datadir);
 
  GNUNET_asprintf (&tex_file_full,
                   "%s%s%s",
                   datadir,
                   DIR_SEPARATOR_STR,
                   "gns-bcd.tex");
  GNUNET_asprintf (&tex_file_simple,
                   "%s%s%s",
                   datadir,
                   DIR_SEPARATOR_STR,
                   "gns-bcd-simple.tex");
  GNUNET_asprintf(&tex_file_png,
                  "%s%s%s",
                  datadir,
                  DIR_SEPARATOR_STR,
                  "gns-bcd-png.tex");
 
  index_simple = open_static_resource ("gns-bcd-simple.html", datadir);
  index_full = open_static_resource ("gns-bcd.html", datadir);
  key_error = open_static_resource ("gns-bcd-invalid-key.html", datadir);
  notfound_error = open_static_resource ("gns-bcd-not-found.html", datadir);
  internal_error = open_static_resource ("gns-bcd-internal-error.html", datadir);
  forbidden_error = open_static_resource ("gns-bcd-forbidden.html", datadir);
 
  GNUNET_free (datadir);
 
  if ((NULL == index_simple) || (NULL == index_full)
      || (NULL == key_error) || (NULL == notfound_error)
      || (NULL == internal_error) || (NULL == forbidden_error))
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                _ ("Unable to set up the daemon\n"));
    GNUNET_SCHEDULER_shutdown ();
    return;
  }
 
  int flags = MHD_USE_DUAL_STACK | MHD_USE_DEBUG | MHD_ALLOW_SUSPEND_RESUME;
  do
  {
    httpd = MHD_start_daemon (flags,
                              port,
                              NULL, NULL,
                              &create_response, NULL,
                              MHD_OPTION_CONNECTION_LIMIT, 512,
                              MHD_OPTION_PER_IP_CONNECTION_LIMIT, 2,
                              MHD_OPTION_CONNECTION_TIMEOUT, 60,
                              MHD_OPTION_CONNECTION_MEMORY_LIMIT, 16 * 1024,
                              MHD_OPTION_END);
    flags = MHD_USE_DEBUG;
  } while (NULL == httpd && flags != MHD_USE_DEBUG);
 
  if (NULL == httpd)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                _ ("Failed to start HTTP server\n"));
    GNUNET_SCHEDULER_shutdown ();
    return;
  }
 
  run_httpd ();
}
 
int
main (int argc, char *const *argv)
{
  struct GNUNET_GETOPT_CommandLineOption options[] = {
    GNUNET_GETOPT_option_uint16 (
      'p',
      "port",
      "PORT",
      gettext_noop ("Run HTTP server on port PORT (default is 8888)"),
      &port),
    GNUNET_GETOPT_OPTION_END,
  };
 
  return ((GNUNET_OK ==
           GNUNET_PROGRAM_run (argc,
                               argv,
                               "gnunet-bcd",
                               _ ("GNUnet HTTP server to create business cards"),
                               options,
                               &run,
                               NULL))
          ? 0
          : 1);
}
 
/* end of gnunet-bcd.c */