aboutsummaryrefslogtreecommitdiff
path: root/src/dns/gnunet-dns-monitor.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/dns/gnunet-dns-monitor.c')
-rw-r--r--src/dns/gnunet-dns-monitor.c353
1 files changed, 353 insertions, 0 deletions
diff --git a/src/dns/gnunet-dns-monitor.c b/src/dns/gnunet-dns-monitor.c
new file mode 100644
index 0000000..82715aa
--- /dev/null
+++ b/src/dns/gnunet-dns-monitor.c
@@ -0,0 +1,353 @@
+/*
+ This file is part of GNUnet.
+ (C) 2011 Christian Grothoff (and other contributing authors)
+
+ 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., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, 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 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";
+ }
+ 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_DNSPARSER_CLASS_INTERNET: return "IN";
+ case GNUNET_DNSPARSER_CLASS_CHAOS: return "CHAOS";
+ case GNUNET_DNSPARSER_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->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 (record->data.soa == NULL)
+ 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_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->class),
+ get_type (record->type),
+ record->name,
+ format,
+ (unsigned int) (GNUNET_TIME_absolute_get_remaining (record->expiration_time).rel_value / 1000));
+ 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, const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+ 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_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
+ &do_disconnect, NULL);
+}
+
+
+int
+main (int argc, char *const *argv)
+{
+ static const struct GNUNET_GETOPT_CommandLineOption options[] = {
+ {'i', "inbound-only", NULL,
+ gettext_noop ("only monitor DNS queries"),
+ 0, &GNUNET_GETOPT_set_one, &inbound_only},
+ {'o', "outbound-only", NULL,
+ gettext_noop ("only monitor DNS replies"),
+ 0, &GNUNET_GETOPT_set_one, &outbound_only},
+ GNUNET_GETOPT_OPTION_VERBOSE (&verbosity),
+ GNUNET_GETOPT_OPTION_END
+ };
+ return (GNUNET_OK ==
+ GNUNET_PROGRAM_run (argc, argv, "gnunet-dns-monitor",
+ gettext_noop
+ ("Monitor DNS queries."), options,
+ &run, NULL)) ? ret : 1;
+}
+
+
+/* end of gnunet-dns-monitor.c */
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-11-21 14:26:48 +0000