GNS: Move VPN to DNS2GNS. Fixes #7171

1 files changed, 209 insertions, 0 deletions

diff --git a/src/gns/gnunet-dns2gns.c b/src/gns/gnunet-dns2gns.c
index 06f4c9841..46659cdda 100644
--- a/src/gns/gnunet-dns2gns.c
+++ b/src/gns/gnunet-dns2gns.c
@@ -27,6 +27,7 @@
 #include <gnunet_dnsparser_lib.h>
 #include <gnunet_gns_service.h>
 #include <gnunet_dnsstub_lib.h>
+#include "gnunet_vpn_service.h"
 #include "gns.h"
 
 /**
@@ -35,6 +36,46 @@
 #define TIMEOUT GNUNET_TIME_UNIT_MINUTES
 
 /**
+ * Default timeout for VPN redirections.
+ */
+#define VPN_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 30)
+
+
+struct Request;
+
+/**
+ * Closure for #vpn_allocation_cb.
+ */
+struct VpnContext
+{
+  /**
+   * Which resolution process are we processing.
+   */
+  struct Request *request;
+
+  /**
+   * Handle to the VPN request that we were performing.
+   */
+  struct GNUNET_VPN_RedirectionRequest *vpn_request;
+
+  /**
+   * Number of records serialized in @e rd_data.
+   */
+  unsigned int rd_count;
+
+  /**
+   * Serialized records.
+   */
+  char *rd_data;
+
+  /**
+   * Number of bytes in @e rd_data.
+   */
+  ssize_t rd_data_size;
+};
+
+
+/**
  * Data kept per request.
  */
 struct Request
@@ -72,6 +113,11 @@ struct Request
   struct GNUNET_SCHEDULER_Task *timeout_task;
 
   /**
+   * Vpn resulution context
+   */
+  struct VpnContext *vpn_ctx;
+
+  /**
    * Original UDP request message.
    */
   char *udp_msg;
@@ -90,6 +136,7 @@ struct Request
    * ID of the original request.
    */
   uint16_t original_request_id;
+
 };
 
 /**
@@ -109,6 +156,11 @@ static struct in6_addr address6;
 struct GNUNET_GNS_Handle *gns;
 
 /**
+ * Our handle to the vpn service
+ */
+static struct GNUNET_VPN_Handle *vpn_handle;
+
+/**
  * Stub resolver
  */
 struct GNUNET_DNSSTUB_Context *dns_stub;
@@ -183,6 +235,11 @@ do_shutdown (void *cls)
     GNUNET_GNS_disconnect (gns);
     gns = NULL;
   }
+  if (NULL != vpn_handle)
+  {
+    GNUNET_VPN_disconnect (vpn_handle);
+    vpn_handle = NULL;
+  }
   if (NULL != dns_stub)
   {
     GNUNET_DNSSTUB_stop (dns_stub);
@@ -269,6 +326,7 @@ static void
 do_timeout (void *cls)
 {
   struct Request *request = cls;
+  struct VpnContext *vpn_ctx;
 
   if (NULL != request->packet)
     GNUNET_DNSPARSER_free_packet (request->packet);
@@ -277,6 +335,12 @@ do_timeout (void *cls)
   if (NULL != request->dns_lookup)
     GNUNET_DNSSTUB_resolve_cancel (request->dns_lookup);
   GNUNET_free (request->udp_msg);
+  if (NULL != (vpn_ctx = request->vpn_ctx))
+  {
+    GNUNET_VPN_cancel_request (vpn_ctx->vpn_request);
+    GNUNET_free (vpn_ctx->rd_data);
+    GNUNET_free (vpn_ctx);
+  }
   GNUNET_free (request);
 }
 
@@ -321,6 +385,79 @@ dns_result_processor (void *cls,
   send_response (request);
 }
 
+/**
+ * Callback invoked from the VPN service once a redirection is
+ * available.  Provides the IP address that can now be used to
+ * reach the requested destination.  Replaces the "VPN" record
+ * with the respective A/AAAA record and continues processing.
+ *
+ * @param cls closure
+ * @param af address family, AF_INET or AF_INET6; AF_UNSPEC on error;
+ *                will match 'result_af' from the request
+ * @param address IP address (struct in_addr or struct in_addr6, depending on 'af')
+ *                that the VPN allocated for the redirection;
+ *                traffic to this IP will now be redirected to the
+ *                specified target peer; NULL on error
+ */
+static void
+vpn_allocation_cb (void *cls,
+                   int af,
+                   const void *address)
+{
+  struct VpnContext *vpn_ctx = cls;
+  struct Request *request = vpn_ctx->request;
+  struct GNUNET_GNSRECORD_Data rd[vpn_ctx->rd_count];
+  unsigned int i;
+
+  vpn_ctx->vpn_request = NULL;
+  request->vpn_ctx = NULL;
+  GNUNET_assert (GNUNET_OK ==
+                 GNUNET_GNSRECORD_records_deserialize (
+                   (size_t) vpn_ctx->rd_data_size,
+                   vpn_ctx->rd_data,
+                   vpn_ctx->rd_count,
+                   rd));
+  for (i = 0; i < vpn_ctx->rd_count; i++)
+  {
+    if (GNUNET_GNSRECORD_TYPE_VPN == rd[i].record_type)
+    {
+      switch (af)
+      {
+      case AF_INET:
+        rd[i].record_type = GNUNET_DNSPARSER_TYPE_A;
+        rd[i].data_size = sizeof(struct in_addr);
+        rd[i].expiration_time = GNUNET_TIME_relative_to_absolute (
+          VPN_TIMEOUT).abs_value_us;
+        rd[i].flags = 0;
+        rd[i].data = address;
+        break;
+
+      case AF_INET6:
+        rd[i].record_type = GNUNET_DNSPARSER_TYPE_AAAA;
+        rd[i].expiration_time = GNUNET_TIME_relative_to_absolute (
+          VPN_TIMEOUT).abs_value_us;
+        rd[i].flags = 0;
+        rd[i].data = address;
+        rd[i].data_size = sizeof(struct in6_addr);
+        break;
+
+      default:
+        GNUNET_assert (0);
+      }
+      break;
+    }
+  }
+  GNUNET_assert (i < vpn_ctx->rd_count);
+  if (0 == vpn_ctx->rd_count)
+    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                _ ("VPN returned empty result for `%s'\n"),
+                request->packet->queries[0].name);
+  send_response (request);
+  GNUNET_free (vpn_ctx->rd_data);
+  GNUNET_free (vpn_ctx);
+}
+
+
 
 /**
  * Iterator called on obtained result for a GNS lookup.
@@ -339,6 +476,11 @@ result_processor (void *cls,
   struct Request *request = cls;
   struct GNUNET_DNSPARSER_Packet *packet;
   struct GNUNET_DNSPARSER_Record rec;
+  struct VpnContext *vpn_ctx;
+  const struct GNUNET_TUN_GnsVpnRecord *vpn;
+  const char *vname;
+  struct GNUNET_HashCode vhash;
+  int af;
 
   request->lookup = NULL;
   if (GNUNET_NO == was_gns)
@@ -415,6 +557,67 @@ result_processor (void *cls,
                            packet->num_answers,
                            rec);
       break;
+    case GNUNET_GNSRECORD_TYPE_VPN:
+      if ((GNUNET_DNSPARSER_TYPE_A != request->packet->queries[0].type) &&
+          (GNUNET_DNSPARSER_TYPE_AAAA != request->packet->queries[0].type))
+        break;
+      af = (GNUNET_DNSPARSER_TYPE_A == request->packet->queries[0].type) ? AF_INET :
+           AF_INET6;
+      if (sizeof(struct GNUNET_TUN_GnsVpnRecord) >
+          rd[i].data_size)
+      {
+        GNUNET_break_op (0);
+        break;
+      }
+      vpn = (const struct GNUNET_TUN_GnsVpnRecord *) rd[i].data;
+      vname = (const char *) &vpn[1];
+      if ('\0' != vname[rd[i].data_size - 1 - sizeof(struct
+                                                     GNUNET_TUN_GnsVpnRecord)
+          ])
+      {
+        GNUNET_break_op (0);
+        break;
+      }
+      GNUNET_TUN_service_name_to_hash (vname,
+                                       &vhash);
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  "Attempting VPN allocation for %s-%s (AF: %d, proto %d)\n",
+                  GNUNET_i2s (&vpn->peer),
+                  vname,
+                  (int) af,
+                  (int) ntohs (vpn->proto));
+      vpn_ctx = GNUNET_new (struct VpnContext);
+      request->vpn_ctx = vpn_ctx;
+      vpn_ctx->request = request;
+      vpn_ctx->rd_data_size = GNUNET_GNSRECORD_records_get_size (rd_count,
+                                                                 rd);
+      if (vpn_ctx->rd_data_size < 0)
+      {
+        GNUNET_break_op (0);
+        GNUNET_free (vpn_ctx);
+        break;
+      }
+      vpn_ctx->rd_data = GNUNET_malloc ((size_t) vpn_ctx->rd_data_size);
+      vpn_ctx->rd_count = rd_count;
+      GNUNET_assert (vpn_ctx->rd_data_size ==
+                     GNUNET_GNSRECORD_records_serialize (rd_count,
+                                                         rd,
+                                                         (size_t) vpn_ctx
+                                                         ->rd_data_size,
+                                                         vpn_ctx->rd_data));
+      vpn_ctx->vpn_request = GNUNET_VPN_redirect_to_peer (vpn_handle,
+                                                          af,
+                                                          ntohs (
+                                                            vpn->proto),
+                                                          &vpn->peer,
+                                                          &vhash,
+                                                          GNUNET_TIME_relative_to_absolute (
+                                                            VPN_TIMEOUT),
+                                                          &
+                                                          vpn_allocation_cb,
+                                                          vpn_ctx);
+      return;
+
 
     default:
       /* skip */
@@ -641,6 +844,8 @@ run (void *cls,
                                  NULL);
   if (NULL == (gns = GNUNET_GNS_connect (cfg)))
     return;
+  if (NULL == (vpn_handle = GNUNET_VPN_connect (cfg)))
+    return;
   GNUNET_assert (NULL != (dns_stub = GNUNET_DNSSTUB_start (128)));
   if (GNUNET_OK !=
       GNUNET_DNSSTUB_add_dns_ip (dns_stub,
@@ -649,6 +854,8 @@ run (void *cls,
     GNUNET_DNSSTUB_stop (dns_stub);
     GNUNET_GNS_disconnect (gns);
     gns = NULL;
+    GNUNET_VPN_disconnect (vpn_handle);
+    vpn_handle = NULL;
     return;
   }
 
@@ -750,6 +957,8 @@ run (void *cls,
   {
     GNUNET_GNS_disconnect (gns);
     gns = NULL;
+    GNUNET_VPN_disconnect (vpn_handle);
+    vpn_handle = NULL;
     GNUNET_DNSSTUB_stop (dns_stub);
     dns_stub = NULL;
     return;