1 files changed, 607 insertions, 0 deletions

diff --git a/src/service/dns/gnunet-zonewalk.c b/src/service/dns/gnunet-zonewalk.c
new file mode 100644
index 000000000..0526df698
--- /dev/null
+++ b/src/service/dns/gnunet-zonewalk.c
@@ -0,0 +1,607 @@
+/*
+     This file is part of GNUnet
+     Copyright (C) 2018 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
+ */
+
+/**
+ * @file src/dns/gnunet-zoneimport.c
+ * @brief import a DNS zone for analysis, brute force
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include <gnunet_util_lib.h>
+
+/**
+ * Request we should make.
+ */
+struct Request
+{
+  /**
+   * Requests are kept in a DLL.
+   */
+  struct Request *next;
+
+  /**
+   * Requests are kept in a DLL.
+   */
+  struct Request *prev;
+
+  /**
+   * Socket used to make the request, NULL if not active.
+   */
+  struct GNUNET_DNSSTUB_RequestSocket *rs;
+
+  /**
+   * Raw DNS query.
+   */
+  void *raw;
+
+  /**
+   * Number of bytes in @e raw.
+   */
+  size_t raw_len;
+
+  /**
+   * Hostname we are resolving.
+   */
+  char *hostname;
+
+  /**
+   * When did we last issue this request?
+   */
+  time_t time;
+
+  /**
+   * How often did we issue this query?
+   */
+  int issue_num;
+
+  /**
+   * random 16-bit DNS query identifier.
+   */
+  uint16_t id;
+};
+
+
+/**
+ * Context for DNS resolution.
+ */
+static struct GNUNET_DNSSTUB_Context *ctx;
+
+/**
+ * The number of queries that are outstanding
+ */
+static unsigned int pending;
+
+/**
+ * Number of lookups we performed overall.
+ */
+static unsigned int lookups;
+
+/**
+ * Number of lookups that failed.
+ */
+static unsigned int failures;
+
+/**
+ * Number of records we found.
+ */
+static unsigned int records;
+
+/**
+ * Head of DLL of all requests to perform.
+ */
+static struct Request *req_head;
+
+/**
+ * Tail of DLL of all requests to perform.
+ */
+static struct Request *req_tail;
+
+/**
+ * Main task.
+ */
+static struct GNUNET_SCHEDULER_Task *t;
+
+/**
+ * Maximum number of queries pending at the same time.
+ */
+#define THRESH 20
+
+/**
+ * TIME_THRESH is in usecs.  How quickly do we submit fresh queries.
+ * Used as an additional throttle.
+ */
+#define TIME_THRESH 10
+
+/**
+ * How often do we retry a query before giving up for good?
+ */
+#define MAX_RETRIES 5
+
+
+/**
+ * We received @a rec for @a req. Remember the answer.
+ *
+ * @param req request
+ * @param rec response
+ */
+static void
+process_record (struct Request *req,
+                struct GNUNET_DNSPARSER_Record *rec)
+{
+  char buf[INET6_ADDRSTRLEN];
+
+  records++;
+  switch (rec->type)
+  {
+  case GNUNET_DNSPARSER_TYPE_A:
+    fprintf (stdout,
+             "%s A %s\n",
+             req->hostname,
+             inet_ntop (AF_INET,
+                        rec->data.raw.data,
+                        buf,
+                        sizeof(buf)));
+    break;
+
+  case GNUNET_DNSPARSER_TYPE_AAAA:
+    fprintf (stdout,
+             "%s AAAA %s\n",
+             req->hostname,
+             inet_ntop (AF_INET6,
+                        rec->data.raw.data,
+                        buf,
+                        sizeof(buf)));
+    break;
+
+  case GNUNET_DNSPARSER_TYPE_NS:
+    fprintf (stdout,
+             "%s NS %s\n",
+             req->hostname,
+             rec->data.hostname);
+    break;
+
+  case GNUNET_DNSPARSER_TYPE_CNAME:
+    fprintf (stdout,
+             "%s CNAME %s\n",
+             req->hostname,
+             rec->data.hostname);
+    break;
+
+  case GNUNET_DNSPARSER_TYPE_MX:
+    fprintf (stdout,
+             "%s MX %u %s\n",
+             req->hostname,
+             (unsigned int) rec->data.mx->preference,
+             rec->data.mx->mxhost);
+    break;
+
+  case GNUNET_DNSPARSER_TYPE_SOA:
+    fprintf (stdout,
+             "%s SOA %s %s %u %u %u %u %u\n",
+             req->hostname,
+             rec->data.soa->mname,
+             rec->data.soa->rname,
+             (unsigned int) rec->data.soa->serial,
+             (unsigned int) rec->data.soa->refresh,
+             (unsigned int) rec->data.soa->retry,
+             (unsigned int) rec->data.soa->expire,
+             (unsigned int) rec->data.soa->minimum_ttl);
+    break;
+
+  case GNUNET_DNSPARSER_TYPE_SRV:
+    fprintf (stdout,
+             "%s SRV %s %u %u %u\n",
+             req->hostname,
+             rec->data.srv->target,
+             rec->data.srv->priority,
+             rec->data.srv->weight,
+             rec->data.srv->port);
+    break;
+
+  case GNUNET_DNSPARSER_TYPE_PTR:
+    fprintf (stdout,
+             "%s PTR %s\n",
+             req->hostname,
+             rec->data.hostname);
+    break;
+
+  case GNUNET_DNSPARSER_TYPE_TXT:
+    fprintf (stdout,
+             "%s TXT %.*s\n",
+             req->hostname,
+             (int) rec->data.raw.data_len,
+             (char *) rec->data.raw.data);
+    break;
+
+  case GNUNET_DNSPARSER_TYPE_DNAME:
+    fprintf (stdout,
+             "%s DNAME %s\n",
+             req->hostname,
+             rec->data.hostname);
+    break;
+
+  /* obscure records */
+  case GNUNET_DNSPARSER_TYPE_AFSDB:
+  case GNUNET_DNSPARSER_TYPE_NAPTR:
+  case GNUNET_DNSPARSER_TYPE_APL:
+  case GNUNET_DNSPARSER_TYPE_DHCID:
+  case GNUNET_DNSPARSER_TYPE_HIP:
+  case GNUNET_DNSPARSER_TYPE_LOC:
+  case GNUNET_DNSPARSER_TYPE_RP:
+  case GNUNET_DNSPARSER_TYPE_TKEY:
+  case GNUNET_DNSPARSER_TYPE_TSIG:
+  case GNUNET_DNSPARSER_TYPE_URI:
+  case GNUNET_DNSPARSER_TYPE_TA:
+
+  /* DNSSEC */
+  case GNUNET_DNSPARSER_TYPE_DS:
+  case GNUNET_DNSPARSER_TYPE_RRSIG:
+  case GNUNET_DNSPARSER_TYPE_NSEC:
+  case GNUNET_DNSPARSER_TYPE_DNSKEY:
+  case GNUNET_DNSPARSER_TYPE_NSEC3:
+  case GNUNET_DNSPARSER_TYPE_NSEC3PARAM:
+  case GNUNET_DNSPARSER_TYPE_CDS:
+  case GNUNET_DNSPARSER_TYPE_CDNSKEY:
+
+  /* DNSSEC payload */
+  case GNUNET_DNSPARSER_TYPE_CERT:
+  case GNUNET_DNSPARSER_TYPE_SSHFP:
+  case GNUNET_DNSPARSER_TYPE_IPSECKEY:
+  case GNUNET_DNSPARSER_TYPE_TLSA:
+  case GNUNET_DNSPARSER_TYPE_OPENPGPKEY:
+
+  /* obsolete records */
+  case GNUNET_DNSPARSER_TYPE_SIG:
+  case GNUNET_DNSPARSER_TYPE_KEY:
+  case GNUNET_DNSPARSER_TYPE_KX:
+    {
+      char *base32;
+
+      base32 = GNUNET_STRINGS_data_to_string_alloc (rec->data.raw.data,
+                                                    rec->data.raw.data_len);
+      fprintf (stdout,
+               "%s (%u) %s\n",
+               req->hostname,
+               rec->type,
+               base32);
+      GNUNET_free (base32);
+    }
+    break;
+
+  default:
+    fprintf (stderr,
+             "Unsupported type %u\n",
+             (unsigned int) rec->type);
+    break;
+  }
+}
+
+
+/**
+ * Function called with the result of a DNS resolution.
+ *
+ * @param cls closure with the `struct Request`
+ * @param dns dns response, never NULL
+ * @param dns_len number of bytes in @a dns
+ */
+static void
+process_result (void *cls,
+                const struct GNUNET_TUN_DnsHeader *dns,
+                size_t dns_len)
+{
+  struct Request *req = cls;
+  struct GNUNET_DNSPARSER_Packet *p;
+
+  if (NULL == dns)
+  {
+    /* stub gave up */
+    pending--;
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Stub gave up on DNS reply for `%s'\n",
+                req->hostname);
+    GNUNET_CONTAINER_DLL_remove (req_head,
+                                 req_tail,
+                                 req);
+    if (req->issue_num > MAX_RETRIES)
+    {
+      failures++;
+      GNUNET_free (req->hostname);
+      GNUNET_free (req->raw);
+      GNUNET_free (req);
+      return;
+    }
+    GNUNET_CONTAINER_DLL_insert_tail (req_head,
+                                      req_tail,
+                                      req);
+    req->rs = NULL;
+    return;
+  }
+  if (req->id != dns->id)
+    return;
+  pending--;
+  GNUNET_DNSSTUB_resolve_cancel (req->rs);
+  req->rs = NULL;
+  GNUNET_CONTAINER_DLL_remove (req_head,
+                               req_tail,
+                               req);
+  p = GNUNET_DNSPARSER_parse ((const char *) dns,
+                              dns_len);
+  if (NULL == p)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Failed to parse DNS reply for `%s'\n",
+                req->hostname);
+    if (req->issue_num > MAX_RETRIES)
+    {
+      failures++;
+      GNUNET_free (req->hostname);
+      GNUNET_free (req->raw);
+      GNUNET_free (req);
+      return;
+    }
+    GNUNET_CONTAINER_DLL_insert_tail (req_head,
+                                      req_tail,
+                                      req);
+    return;
+  }
+  for (unsigned int i = 0; i < p->num_answers; i++)
+  {
+    struct GNUNET_DNSPARSER_Record *rs = &p->answers[i];
+
+    process_record (req,
+                    rs);
+  }
+  for (unsigned int i = 0; i < p->num_authority_records; i++)
+  {
+    struct GNUNET_DNSPARSER_Record *rs = &p->authority_records[i];
+
+    process_record (req,
+                    rs);
+  }
+  for (unsigned int i = 0; i < p->num_additional_records; i++)
+  {
+    struct GNUNET_DNSPARSER_Record *rs = &p->additional_records[i];
+
+    process_record (req,
+                    rs);
+  }
+  GNUNET_DNSPARSER_free_packet (p);
+  GNUNET_free (req->hostname);
+  GNUNET_free (req->raw);
+  GNUNET_free (req);
+}
+
+
+/**
+ * Submit a request to DNS unless we need to slow down because
+ * we are at the rate limit.
+ *
+ * @param req request to submit
+ * @return #GNUNET_OK if request was submitted
+ *         #GNUNET_NO if request was already submitted
+ *         #GNUNET_SYSERR if we are at the rate limit
+ */
+static int
+submit_req (struct Request *req)
+{
+  static struct timeval last_request;
+  struct timeval now;
+
+  if (NULL != req->rs)
+    return GNUNET_NO; /* already submitted */
+  gettimeofday (&now,
+                NULL);
+  if ((((now.tv_sec - last_request.tv_sec) == 0) &&
+       ((now.tv_usec - last_request.tv_usec) < TIME_THRESH)) ||
+      (pending >= THRESH))
+    return GNUNET_SYSERR;
+  GNUNET_assert (NULL == req->rs);
+  req->rs = GNUNET_DNSSTUB_resolve (ctx,
+                                    req->raw,
+                                    req->raw_len,
+                                    &process_result,
+                                    req);
+  GNUNET_assert (NULL != req->rs);
+  req->issue_num++;
+  last_request = now;
+  lookups++;
+  pending++;
+  req->time = time (NULL);
+  return GNUNET_OK;
+}
+
+
+/**
+ * Process as many requests as possible from the queue.
+ *
+ * @param cls NULL
+ */
+static void
+process_queue (void *cls)
+{
+  (void) cls;
+  t = NULL;
+  for (struct Request *req = req_head;
+       NULL != req;
+       req = req->next)
+  {
+    if (GNUNET_SYSERR == submit_req (req))
+      break;
+  }
+  if (NULL != req_head)
+    t = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MILLISECONDS,
+                                      &process_queue,
+                                      NULL);
+  else
+    GNUNET_SCHEDULER_shutdown ();
+}
+
+
+/**
+ * Clean up and terminate the process.
+ *
+ * @param cls NULL
+ */
+static void
+do_shutdown (void *cls)
+{
+  (void) cls;
+  if (NULL != t)
+  {
+    GNUNET_SCHEDULER_cancel (t);
+    t = NULL;
+  }
+  GNUNET_DNSSTUB_stop (ctx);
+  ctx = NULL;
+}
+
+
+/**
+ * Process requests from the queue, then if the queue is
+ * not empty, try again.
+ *
+ * @param cls NULL
+ */
+static void
+run (void *cls)
+{
+  (void) cls;
+
+  GNUNET_SCHEDULER_add_shutdown (&do_shutdown,
+                                 NULL);
+  t = GNUNET_SCHEDULER_add_now (&process_queue,
+                                NULL);
+}
+
+
+/**
+ * Add @a hostname to the list of requests to be made.
+ *
+ * @param hostname name to resolve
+ */
+static void
+queue (const char *hostname)
+{
+  struct GNUNET_DNSPARSER_Packet p;
+  struct GNUNET_DNSPARSER_Query q;
+  struct Request *req;
+  char *raw;
+  size_t raw_size;
+  int ret;
+
+  if (GNUNET_OK !=
+      GNUNET_DNSPARSER_check_name (hostname))
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Refusing invalid hostname `%s'\n",
+                hostname);
+    return;
+  }
+  q.name = (char *) hostname;
+  q.type = GNUNET_DNSPARSER_TYPE_NS;
+  q.dns_traffic_class = GNUNET_TUN_DNS_CLASS_INTERNET;
+
+  memset (&p,
+          0,
+          sizeof(p));
+  p.num_queries = 1;
+  p.queries = &q;
+  p.id = (uint16_t) GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
+                                              UINT16_MAX);
+  ret = GNUNET_DNSPARSER_pack (&p,
+                               UINT16_MAX,
+                               &raw,
+                               &raw_size);
+  if (GNUNET_OK != ret)
+  {
+    if (GNUNET_NO == ret)
+      GNUNET_free (raw);
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Failed to pack query for hostname `%s'\n",
+                hostname);
+    return;
+  }
+
+  req = GNUNET_new (struct Request);
+  req->hostname = strdup (hostname);
+  req->raw = raw;
+  req->raw_len = raw_size;
+  req->id = p.id;
+  GNUNET_CONTAINER_DLL_insert_tail (req_head,
+                                    req_tail,
+                                    req);
+}
+
+
+/**
+ * Call with IP address of resolver to query.
+ *
+ * @param argc should be 2
+ * @param argv[1] should contain IP address
+ * @return 0 on success
+ */
+int
+main (int argc,
+      char **argv)
+{
+  char hn[256];
+
+  if (2 != argc)
+  {
+    fprintf (stderr,
+             "Missing required configuration argument\n");
+    return -1;
+  }
+  ctx = GNUNET_DNSSTUB_start (256);
+  if (NULL == ctx)
+  {
+    fprintf (stderr,
+             "Failed to initialize GNUnet DNS STUB\n");
+    return 1;
+  }
+  if (GNUNET_OK !=
+      GNUNET_DNSSTUB_add_dns_ip (ctx,
+                                 argv[1]))
+  {
+    fprintf (stderr,
+             "Failed to use `%s' for DNS resolver\n",
+             argv[1]);
+    return 1;
+  }
+
+  while (NULL !=
+         fgets (hn,
+                sizeof(hn),
+                stdin))
+  {
+    if (strlen (hn) > 0)
+      hn[strlen (hn) - 1] = '\0';  /* eat newline */
+    queue (hn);
+  }
+  GNUNET_SCHEDULER_run (&run,
+                        NULL);
+  fprintf (stderr,
+           "Did %u lookups, found %u records, %u lookups failed, %u pending on shutdown\n",
+           lookups,
+           records,
+           failures,
+           pending);
+  return 0;
+}