gnunet-dns-monitor.c File Reference

Tool to monitor DNS queries. More...

#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_dns_service.h"
#include "gnunet_dnsparser_lib.h"

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Functions
static const char *	get_type (uint16_t type)
	Convert numeric DNS record type to a string. More...
static const char *	get_class (uint16_t class)
	Convert numeric DNS record class to a string. More...
static void	display_query (const struct GNUNET_DNSPARSER_Query *query)
	Output the given DNS query to stdout. More...
static void	display_record (const struct GNUNET_DNSPARSER_Record *record)
	Output the given DNS record to stdout. More...
static void	display_request (void *cls, struct GNUNET_DNS_RequestHandle *rh, size_t request_length, const char *request)
	Signature of a function that is called whenever the DNS service encounters a DNS request and needs to do something with it. More...
static void	do_disconnect (void *cls)
	Shutdown. 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 struct GNUNET_DNS_Handle *	handle
	Handle to transport service. More...
static int	inbound_only
	Option -i. More...
static int	outbound_only
	Option -o. More...
static int	ret
	Global return value (0 success). More...
static unsigned int	verbosity
	Selected level of verbosity. More...

Detailed Description

Tool to monitor DNS queries.

Author

Christian Grothoff

Definition in file gnunet-dns-monitor.c.

Function Documentation

get_type()

static const char* get_type ( uint16_t  type )

static

Convert numeric DNS record type to a string.

Parameters

type	type to convert

Returns

type as string, only valid until the next call to this function

Definition at line 65 of file gnunet-dns-monitor.c.

References buf, GNUNET_DNSPARSER_TYPE_A, GNUNET_DNSPARSER_TYPE_AAAA, GNUNET_DNSPARSER_TYPE_CNAME, GNUNET_DNSPARSER_TYPE_MX, GNUNET_DNSPARSER_TYPE_NS, GNUNET_DNSPARSER_TYPE_PTR, GNUNET_DNSPARSER_TYPE_SOA, GNUNET_DNSPARSER_TYPE_SRV, GNUNET_DNSPARSER_TYPE_TXT, and GNUNET_snprintf().

Referenced by display_query(), and display_record().

{
  static char buf[6];

  switch (type)
  {
  case GNUNET_DNSPARSER_TYPE_A: return "A";

  case GNUNET_DNSPARSER_TYPE_NS: return "NS";

  case GNUNET_DNSPARSER_TYPE_CNAME: return "CNAME";

  case GNUNET_DNSPARSER_TYPE_SOA: return "SOA";

  case GNUNET_DNSPARSER_TYPE_PTR: return "PTR";

  case GNUNET_DNSPARSER_TYPE_MX: return "MX";

  case GNUNET_DNSPARSER_TYPE_TXT: return "TXT";

  case GNUNET_DNSPARSER_TYPE_AAAA: return "AAAA";

  case GNUNET_DNSPARSER_TYPE_SRV: return "SRV";
  }
  GNUNET_snprintf (buf, sizeof(buf), "%u", (unsigned int) type);
  return buf;
}

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get_class()

static const char* get_class ( uint16_t  class )

static

Convert numeric DNS record class to a string.

Parameters

class

class to convert

Returns

class as string, only valid until the next call to this function

Definition at line 101 of file gnunet-dns-monitor.c.

References buf, GNUNET_snprintf(), GNUNET_TUN_DNS_CLASS_CHAOS, GNUNET_TUN_DNS_CLASS_HESIOD, and GNUNET_TUN_DNS_CLASS_INTERNET.

Referenced by display_query(), and display_record().

{
  static char buf[6];

  switch (class)
  {
  case GNUNET_TUN_DNS_CLASS_INTERNET: return "IN";

  case GNUNET_TUN_DNS_CLASS_CHAOS: return "CHAOS";

  case GNUNET_TUN_DNS_CLASS_HESIOD: return "HESIOD";
  }
  GNUNET_snprintf (buf, sizeof(buf), "%u", (unsigned int) class);
  return buf;
}

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display_query()

static void display_query ( const struct GNUNET_DNSPARSER_Query *  query )

static

Output the given DNS query to stdout.

Parameters

query

query to display.

Definition at line 124 of file gnunet-dns-monitor.c.

References GNUNET_DNSPARSER_Query::dns_traffic_class, get_class(), get_type(), GNUNET_DNSPARSER_Query::name, and GNUNET_DNSPARSER_Query::type.

Referenced by display_request().

{
  fprintf (stdout,
           "\t\t%s %s: %s\n",
           get_class (query->dns_traffic_class),
           get_type (query->type),
           query->name);
}

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display_record()

static void display_record ( const struct GNUNET_DNSPARSER_Record *  record )

static

Output the given DNS record to stdout.

Parameters

record

record to display.

Definition at line 140 of file gnunet-dns-monitor.c.

References buf, GNUNET_DNSPARSER_RawRecord::data, GNUNET_DNSPARSER_Record::data, GNUNET_DNSPARSER_RawRecord::data_len, GNUNET_DNSPARSER_Record::dns_traffic_class, GNUNET_DNSPARSER_Record::expiration_time, GNUNET_DNSPARSER_SoaRecord::expire, get_class(), get_type(), GNUNET_asprintf(), GNUNET_DNSPARSER_TYPE_A, GNUNET_DNSPARSER_TYPE_AAAA, GNUNET_DNSPARSER_TYPE_CNAME, GNUNET_DNSPARSER_TYPE_MX, GNUNET_DNSPARSER_TYPE_NS, GNUNET_DNSPARSER_TYPE_PTR, GNUNET_DNSPARSER_TYPE_SOA, GNUNET_DNSPARSER_TYPE_SRV, GNUNET_DNSPARSER_TYPE_TXT, GNUNET_free, GNUNET_TIME_absolute_get_remaining(), GNUNET_DNSPARSER_Record::hostname, GNUNET_DNSPARSER_SoaRecord::minimum_ttl, GNUNET_DNSPARSER_SoaRecord::mname, GNUNET_DNSPARSER_Record::mx, GNUNET_DNSPARSER_MxRecord::mxhost, GNUNET_DNSPARSER_Record::name, GNUNET_DNSPARSER_SrvRecord::port, GNUNET_DNSPARSER_MxRecord::preference, GNUNET_DNSPARSER_SrvRecord::priority, GNUNET_DNSPARSER_Record::raw, GNUNET_DNSPARSER_SoaRecord::refresh, GNUNET_TIME_Relative::rel_value_us, GNUNET_DNSPARSER_SoaRecord::retry, GNUNET_DNSPARSER_SoaRecord::rname, GNUNET_DNSPARSER_SoaRecord::serial, GNUNET_DNSPARSER_Record::soa, GNUNET_DNSPARSER_Record::srv, GNUNET_DNSPARSER_SrvRecord::target, GNUNET_DNSPARSER_Record::type, and GNUNET_DNSPARSER_SrvRecord::weight.

Referenced by display_request().

{
  const char *format;
  char buf[INET6_ADDRSTRLEN];
  char *tmp;

  tmp = NULL;
  switch (record->type)
  {
  case GNUNET_DNSPARSER_TYPE_A:
    if (record->data.raw.data_len != sizeof(struct in_addr))
      format = "<invalid>";
    else
      format = inet_ntop (AF_INET, record->data.raw.data, buf, sizeof(buf));
    break;

  case GNUNET_DNSPARSER_TYPE_AAAA:
    if (record->data.raw.data_len != sizeof(struct in6_addr))
      format = "<invalid>";
    else
      format = inet_ntop (AF_INET6, record->data.raw.data, buf, sizeof(buf));
    break;

  case GNUNET_DNSPARSER_TYPE_NS:
  case GNUNET_DNSPARSER_TYPE_CNAME:
  case GNUNET_DNSPARSER_TYPE_PTR:
    format = record->data.hostname;
    break;

  case GNUNET_DNSPARSER_TYPE_SOA:
    if (NULL == record->data.soa)
      format = "<invalid>";
    else
    {
      GNUNET_asprintf (&tmp,
                       "origin: %s, mail: %s, serial = %u, refresh = %u s, retry = %u s, expire = %u s, minimum = %u s",
                       record->data.soa->mname,
                       record->data.soa->rname,
                       (unsigned int) record->data.soa->serial,
                       (unsigned int) record->data.soa->refresh,
                       (unsigned int) record->data.soa->retry,
                       (unsigned int) record->data.soa->expire,
                       (unsigned int) record->data.soa->minimum_ttl);
      format = tmp;
    }
    break;

  case GNUNET_DNSPARSER_TYPE_MX:
    if (record->data.mx == NULL)
      format = "<invalid>";
    else
    {
      GNUNET_asprintf (&tmp,
                       "%u: %s",
                       record->data.mx->preference,
                       record->data.mx->mxhost);
      format = tmp;
    }
    break;

  case GNUNET_DNSPARSER_TYPE_SRV:
    if (NULL == record->data.srv)
      format = "<invalid>";
    else
    {
      GNUNET_asprintf (&tmp,
                       "priority %u, weight = %u, port = %u, target = %s",
                       (unsigned int) record->data.srv->priority,
                       (unsigned int) record->data.srv->weight,
                       (unsigned int) record->data.srv->port,
                       record->data.srv->target);
      format = tmp;
    }
    break;

  case GNUNET_DNSPARSER_TYPE_TXT:
    GNUNET_asprintf (&tmp,
                     "%.*s",
                     (unsigned int) record->data.raw.data_len,
                     (char*) record->data.raw.data);
    format = tmp;
    break;

  default:
    format = "<payload>";
    break;
  }
  fprintf (stdout,
           "\t\t%s %s: %s = %s (%u s)\n",
           get_class (record->dns_traffic_class),
           get_type (record->type),
           record->name,
           format,
           (unsigned int) (GNUNET_TIME_absolute_get_remaining (
                             record->expiration_time).rel_value_us / 1000LL
                           / 1000LL));
  GNUNET_free (tmp);
}

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display_request()

static void display_request ( void *  cls, struct GNUNET_DNS_RequestHandle *  rh, size_t  request_length, const char *  request  )

static

Signature of a function that is called whenever the DNS service encounters a DNS request and needs to do something with it.

The function has then the chance to generate or modify the response by calling one of the three "GNUNET_DNS_request_*" continuations.

When a request is intercepted, this function is called first to give the client a chance to do the complete address resolution; "rdata" will be NULL for this first call for a DNS request, unless some other client has already filled in a response.

If multiple clients exist, all of them are called before the global DNS. The global DNS is only called if all of the clients' functions call GNUNET_DNS_request_forward. Functions that call GNUNET_DNS_request_forward will be called again before a final response is returned to the application. If any of the clients' functions call GNUNET_DNS_request_drop, the response is dropped.

Parameters

cls	closure
rh	request handle to user for reply
request_length	number of bytes in request
request	udp payload of the DNS request

Definition at line 264 of file gnunet-dns-monitor.c.

References GNUNET_DNSPARSER_Packet::answers, GNUNET_TUN_DnsFlags::authenticated_data, GNUNET_TUN_DnsFlags::authoritative_answer, GNUNET_TUN_DnsFlags::checking_disabled, display_query(), display_record(), GNUNET_DNSPARSER_Packet::flags, GNUNET_DNS_request_forward(), GNUNET_DNSPARSER_free_packet(), GNUNET_DNSPARSER_parse(), GNUNET_DNSPARSER_Packet::id, GNUNET_TUN_DnsFlags::message_truncated, GNUNET_DNSPARSER_Packet::num_answers, GNUNET_DNSPARSER_Packet::num_queries, GNUNET_TUN_DnsFlags::opcode, p, GNUNET_DNSPARSER_Packet::queries, GNUNET_TUN_DnsFlags::query_or_response, GNUNET_TUN_DnsFlags::recursion_available, GNUNET_TUN_DnsFlags::recursion_desired, and GNUNET_TUN_DnsFlags::return_code.

Referenced by run().

{
  static const char *return_codes[] = {
    "No error", "Format error", "Server failure", "Name error",
    "Not implemented", "Refused", "YXDomain", "YXRRset",
    "NXRRset", "NOT AUTH", "NOT ZONE", "<invalid>",
    "<invalid>", "<invalid>", "<invalid>", "<invalid>"
  };
  static const char *op_codes[] = {
    "Query", "Inverse query", "Status", "<invalid>",
    "<invalid>", "<invalid>", "<invalid>", "<invalid>",
    "<invalid>", "<invalid>", "<invalid>", "<invalid>",
    "<invalid>", "<invalid>", "<invalid>", "<invalid>"
  };
  struct GNUNET_DNSPARSER_Packet *p;
  unsigned int i;

  p = GNUNET_DNSPARSER_parse (request, request_length);
  if (NULL == p)
  {
    fprintf (stderr, "Received malformed DNS packet!\n");
    // FIXME: drop instead?
    GNUNET_DNS_request_forward (rh);
    return;
  }
  fprintf (stdout,
           "%s with ID: %5u Flags: %s%s%s%s%s%s, Return Code: %s, Opcode: %s\n",
           p->flags.query_or_response ? "Response" : "Query",
           p->id,
           p->flags.recursion_desired ? "RD " : "",
           p->flags.message_truncated ? "MT " : "",
           p->flags.authoritative_answer ? "AA " : "",
           p->flags.checking_disabled ? "CD " : "",
           p->flags.authenticated_data ? "AD " : "",
           p->flags.recursion_available ? "RA " : "",
           return_codes[p->flags.return_code & 15],
           op_codes[p->flags.opcode & 15]);
  if (p->num_queries > 0)
    fprintf (stdout,
             "\tQueries:\n");
  for (i = 0; i < p->num_queries; i++)
    display_query (&p->queries[i]);

  if (p->num_answers > 0)
    fprintf (stdout,
             "\tAnswers:\n");
  for (i = 0; i < p->num_answers; i++)
    display_record (&p->answers[i]);
  fprintf (stdout, "\n");
  GNUNET_DNSPARSER_free_packet (p);
  GNUNET_DNS_request_forward (rh);
}

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do_disconnect()

static void do_disconnect ( void *  cls )

static

Shutdown.

Definition at line 325 of file gnunet-dns-monitor.c.

References GNUNET_DNS_disconnect().

Referenced by run().

{
  if (NULL != handle)
  {
    GNUNET_DNS_disconnect (handle);
    handle = NULL;
  }
}

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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 344 of file gnunet-dns-monitor.c.

References display_request(), do_disconnect(), GNUNET_DNSPARSER_Packet::flags, GNUNET_DNS_connect(), GNUNET_DNS_FLAG_REQUEST_MONITOR, GNUNET_DNS_FLAG_RESPONSE_MONITOR, GNUNET_SCHEDULER_add_shutdown(), inbound_only, and outbound_only.

Referenced by main().

{
  enum GNUNET_DNS_Flags flags;

  flags = GNUNET_DNS_FLAG_REQUEST_MONITOR | GNUNET_DNS_FLAG_RESPONSE_MONITOR;
  if (inbound_only | outbound_only)
    flags = 0;
  if (inbound_only)
    flags |= GNUNET_DNS_FLAG_REQUEST_MONITOR;
  if (outbound_only)
    flags |= GNUNET_DNS_FLAG_RESPONSE_MONITOR;
  handle =
    GNUNET_DNS_connect (cfg,
                        flags,
                        &display_request,
                        NULL);
  GNUNET_SCHEDULER_add_shutdown (&do_disconnect, NULL);
}

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main()

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

Definition at line 366 of file gnunet-dns-monitor.c.

References gettext_noop, GNUNET_free_nz, GNUNET_GETOPT_OPTION_END, GNUNET_GETOPT_option_flag(), GNUNET_GETOPT_option_verbose(), GNUNET_OK, GNUNET_PROGRAM_run(), GNUNET_STRINGS_get_utf8_args(), inbound_only, outbound_only, ret, run(), and verbosity.

{
  struct GNUNET_GETOPT_CommandLineOption options[] = {
    GNUNET_GETOPT_option_flag ('i',
                               "inbound-only",
                               gettext_noop ("only monitor DNS queries"),
                               &inbound_only),

    GNUNET_GETOPT_option_flag ('o',
                               "outbound-only",
                               gettext_noop ("only monitor DNS queries"),
                               &outbound_only),

    GNUNET_GETOPT_option_verbose (&verbosity),
    GNUNET_GETOPT_OPTION_END
  };

  if (GNUNET_OK != GNUNET_STRINGS_get_utf8_args (argc, argv, &argc, &argv))
    return 2;
  ret = (GNUNET_OK ==
         GNUNET_PROGRAM_run (argc, argv, "gnunet-dns-monitor",
                             gettext_noop
                               ("Monitor DNS queries."), options,
                             &run, NULL)) ? ret : 1;
  GNUNET_free_nz ((void *) argv);
  return ret;
}

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Variable Documentation

handle

struct GNUNET_DNS_Handle* handle

static

Handle to transport service.

Definition at line 35 of file gnunet-dns-monitor.c.

Referenced by add_attribute_cont(), add_credential_cont(), add_get_request_to_pending(), add_list_handle(), add_service_handle(), aes_128_cbc_decrypt(), aes_128_cbc_encrypt(), attr_collect(), authorize_endpoint(), build_authz_response(), build_redirect(), cleanup_handle(), client_redirect(), code_redirect(), collect_finished_cb(), consume_cont(), consume_ticket(), consume_ticket_cont(), consume_timeout(), create_finished(), create_handle(), create_room(), cred_collect(), del_finished(), delete_attribute_cont(), delete_credential_cont(), delete_finished_cb(), do_error(), do_finished(), do_finished_create(), do_redirect_error(), do_timeout(), do_userinfo_error(), dump_pc(), ecdsa_symmetric_decrypt(), ecdsa_symmetric_encrypt(), ego_create(), ego_delete_name(), ego_delete_pubkey(), ego_edit_name(), ego_edit_pubkey(), ego_edit_subsystem(), ego_get_all(), ego_get_for_subsystem(), ego_get_name(), ego_get_pubkey(), ego_get_subsystem(), finished_cont(), get_cont(), get_gns_cont(), GNUNET_ABD_collect(), GNUNET_ABD_connect(), GNUNET_ABD_request_cancel(), GNUNET_ABD_verify(), GNUNET_CRYPTO_symmetric_decrypt(), GNUNET_CRYPTO_symmetric_encrypt(), GNUNET_DHT_connect(), GNUNET_DHT_get_start(), GNUNET_DHT_get_stop(), GNUNET_DHT_monitor_start(), GNUNET_DHT_monitor_stop(), GNUNET_DHT_put(), GNUNET_DHT_put_cancel(), GNUNET_GNS_connect(), GNUNET_GNS_lookup_cancel(), GNUNET_GNS_lookup_limited(), GNUNET_GNS_lookup_with_tld(), GNUNET_MESSENGER_connect(), GNUNET_STATISTICS_get(), GNUNET_TRANSPORT_core_get_mq(), GST_connection_pool_get_handle(), handle_client_result(), handle_get_key(), handle_get_name(), handle_gns_response(), handle_intermediate(), handle_member_id(), handle_monitor_get(), handle_monitor_get_resp(), handle_monitor_put(), handle_recv_message(), handle_result(), handle_room_close(), handle_room_entry(), handle_room_open(), handle_service_message(), handle_ticket_result(), header_iterator(), iterate_send_room_message(), list_attribute_cont(), list_credential_cont(), list_tickets_cont(), login_cont(), login_redirect(), lookup_redirect_uri_result(), message_sent_cont(), mq_error_handler(), namestore_add(), namestore_add_or_update(), namestore_delete(), namestore_get(), namestore_iteration_error(), namestore_list_finished(), namestore_list_iteration(), namestore_update(), neighbour_delete(), ns_get_lookup_cb(), ns_lookup_cb(), ns_lookup_error_cb(), oidc_attr_collect(), oidc_attr_collect_finished_cb(), oidc_config_cors(), oidc_config_endpoint(), oidc_cred_collect(), oidc_cred_collect_finished_cb(), oidc_iteration_error(), oidc_ticket_issue_cb(), options_cont(), peerinfo_get(), peerinfo_list_finished(), peerinfo_list_iteration(), plugin_callback(), post_data_iter(), reconnect_task(), rest_config_process_request(), rest_copying_process_request(), rest_identity_process_request(), rest_process_request(), return_response(), revoke_ticket_cont(), send_room_message(), send_room_message_ext(), set_cont(), store_ticket_issue_cont(), ticket_collect(), tld_iter(), token_endpoint(), url_iterator(), and userinfo_endpoint().

inbound_only

int inbound_only

static

Option -i.

Definition at line 40 of file gnunet-dns-monitor.c.

Referenced by main(), and run().

outbound_only

int outbound_only

static

Option -o.

Definition at line 45 of file gnunet-dns-monitor.c.

Referenced by main(), and run().

ret

int ret

static

Global return value (0 success).

Definition at line 50 of file gnunet-dns-monitor.c.

Referenced by main().

verbosity

unsigned int verbosity

static

Selected level of verbosity.

Definition at line 55 of file gnunet-dns-monitor.c.

Referenced by main().