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- /*
- This file is part of GNUnet.
- Copyright (C) 2011 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 src/dns/gnunet-dns-monitor.c
- * @brief Tool to monitor DNS queries
- * @author Christian Grothoff
- */
- #include "platform.h"
- #include "gnunet_util_lib.h"
- #include "gnunet_dns_service.h"
- #include "gnunet_dnsparser_lib.h"
- /**
- * Handle to transport service.
- */
- static struct GNUNET_DNS_Handle *handle;
- /**
- * Option -i.
- */
- static int inbound_only;
- /**
- * Option -o.
- */
- static int outbound_only;
- /**
- * Global return value (0 success).
- */
- static int ret;
- /**
- * Selected level of verbosity.
- */
- static unsigned int verbosity;
- /**
- * Convert numeric DNS record type to a string.
- *
- * @param type type to convert
- * @return type as string, only valid until the next call to this function
- */
- static const char *
- get_type (uint16_t type)
- {
- 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;
- }
- /**
- * Convert numeric DNS record class to a string.
- *
- * @param class class to convert
- * @return class as string, only valid until the next call to this function
- */
- static const char *
- get_class (uint16_t class)
- {
- 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;
- }
- /**
- * Output the given DNS query to stdout.
- *
- * @param query query to display.
- */
- static void
- display_query (const struct GNUNET_DNSPARSER_Query *query)
- {
- fprintf (stdout,
- "\t\t%s %s: %s\n",
- get_class (query->dns_traffic_class),
- get_type (query->type),
- query->name);
- }
- /**
- * Output the given DNS record to stdout.
- *
- * @param record record to display.
- */
- static void
- display_record (const struct GNUNET_DNSPARSER_Record *record)
- {
- 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 = %s, 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,
- 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_non_null (tmp);
- }
- /**
- * 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.
- *
- * @param cls closure
- * @param rh request handle to user for reply
- * @param request_length number of bytes in request
- * @param request udp payload of the DNS request
- */
- static void
- display_request (void *cls,
- struct GNUNET_DNS_RequestHandle *rh,
- size_t request_length,
- const char *request)
- {
- 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);
- }
- /**
- * Shutdown.
- */
- static void
- do_disconnect (void *cls)
- {
- if (NULL != handle)
- {
- GNUNET_DNS_disconnect (handle);
- handle = NULL;
- }
- }
- /**
- * 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)
- {
- 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);
- }
- int
- main (int argc, char *const *argv)
- {
- 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 ((void*) argv);
- return ret;
- }
- /* end of gnunet-dns-monitor.c */
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