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[GNUnet-SVN] r29472 - in gnunet/src: include pt
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From: |
gnunet |
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Subject: |
[GNUnet-SVN] r29472 - in gnunet/src: include pt |
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Date: |
Sun, 22 Sep 2013 21:18:15 +0200 |
Author: grothoff
Date: 2013-09-22 21:18:15 +0200 (Sun, 22 Sep 2013)
New Revision: 29472
Modified:
gnunet/src/include/gnunet_mesh_service.h
gnunet/src/pt/gnunet-daemon-pt.c
Log:
#2915: supporting multiple DNS exits and ranking among them
Modified: gnunet/src/include/gnunet_mesh_service.h
===================================================================
--- gnunet/src/include/gnunet_mesh_service.h 2013-09-22 17:30:53 UTC (rev
29471)
+++ gnunet/src/include/gnunet_mesh_service.h 2013-09-22 19:18:15 UTC (rev
29472)
@@ -155,9 +155,7 @@
* (can be NULL -- that's not an error)
*/
typedef void *(GNUNET_MESH_InboundTunnelNotificationHandler) (void *cls,
- struct
-
GNUNET_MESH_Tunnel
- * tunnel,
+ struct
GNUNET_MESH_Tunnel *tunnel,
const struct
GNUNET_PeerIdentity
* initiator,
@@ -203,7 +201,8 @@
* (in this case, init is never called)
*/
struct GNUNET_MESH_Handle *
-GNUNET_MESH_connect (const struct GNUNET_CONFIGURATION_Handle *cfg, void *cls,
+GNUNET_MESH_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
+ void *cls,
GNUNET_MESH_InboundTunnelNotificationHandler new_tunnel,
GNUNET_MESH_TunnelEndHandler cleaner,
const struct GNUNET_MESH_MessageHandler *handlers,
Modified: gnunet/src/pt/gnunet-daemon-pt.c
===================================================================
--- gnunet/src/pt/gnunet-daemon-pt.c 2013-09-22 17:30:53 UTC (rev 29471)
+++ gnunet/src/pt/gnunet-daemon-pt.c 2013-09-22 19:18:15 UTC (rev 29472)
@@ -50,7 +50,12 @@
*/
#define MAX_DNS_SIZE (8 * 1024)
+/**
+ * How many tunnels do we open at most at the same time?
+ */
+#define MAX_OPEN_TUNNELS 4
+
/**
* Which group of DNS records are we currently processing?
*/
@@ -117,6 +122,79 @@
/**
+ * Handle to a peer that advertised that it is willing to serve
+ * as a DNS exit. We try to keep a few tunnels open and a few
+ * peers in reserve.
+ */
+struct MeshExit
+{
+
+ /**
+ * Kept in a DLL.
+ */
+ struct MeshExit *next;
+
+ /**
+ * Kept in a DLL.
+ */
+ struct MeshExit *prev;
+
+ /**
+ * Tunnel we use for DNS requests over MESH, NULL if we did
+ * not initialze a tunnel to this peer yet.
+ */
+ struct GNUNET_MESH_Tunnel *mesh_tunnel;
+
+ /**
+ * At what time did the peer's advertisement expire?
+ */
+ struct GNUNET_TIME_Absolute expiration;
+
+ /**
+ * Head of DLL of requests waiting for a response.
+ */
+ struct RequestContext *receive_queue_head;
+
+ /**
+ * Tail of DLL of requests waiting for a response.
+ */
+ struct RequestContext *receive_queue_tail;
+
+ /**
+ * Head of DLL of requests to be transmitted to a mesh_tunnel.
+ */
+ struct RequestContext *transmit_queue_head;
+
+ /**
+ * Tail of DLL of requests to be transmitted to a mesh_tunnel.
+ */
+ struct RequestContext *transmit_queue_tail;
+
+ /**
+ * Active transmission request for this tunnel (or NULL).
+ */
+ struct GNUNET_MESH_TransmitHandle *mesh_th;
+
+ /**
+ * Identity of the peer that is providing the exit for us.
+ */
+ struct GNUNET_PeerIdentity peer;
+
+ /**
+ * How many DNS requests did we transmit via this tunnel?
+ */
+ unsigned int num_transmitted;
+
+ /**
+ * How many DNS requests were answered via this tunnel?
+ */
+ unsigned int num_answered;
+
+};
+
+
+
+/**
* State we keep for a request that is going out via MESH.
*/
struct RequestContext
@@ -132,6 +210,11 @@
struct RequestContext *prev;
/**
+ * Exit that was chosen for this request.
+ */
+ struct MeshExit *exit;
+
+ /**
* Handle for interaction with DNS service.
*/
struct GNUNET_DNS_RequestHandle *rh;
@@ -148,6 +231,11 @@
GNUNET_SCHEDULER_TaskIdentifier timeout_task;
/**
+ * Length of the request message that follows this struct.
+ */
+ uint16_t mlen;
+
+ /**
* ID of the original DNS request (used to match the reply).
*/
uint16_t dns_id;
@@ -162,6 +250,18 @@
/**
+ * Head of DLL of mesh exits. Mesh exits with an open tunnel are
+ * always at the beginning (so we do not have to traverse the entire
+ * list to find them).
+ */
+static struct MeshExit *exit_head;
+
+/**
+ * Tail of DLL of mesh exits.
+ */
+static struct MeshExit *exit_tail;
+
+/**
* The handle to the configuration used throughout the process
*/
static const struct GNUNET_CONFIGURATION_Handle *cfg;
@@ -177,38 +277,6 @@
static struct GNUNET_MESH_Handle *mesh_handle;
/**
- * Tunnel we use for DNS requests over MESH.
- * FIXME: we might want to keep multiple tunnels open
- * at all times...
- */
-static struct GNUNET_MESH_Tunnel *mesh_tunnel;
-
-/**
- * Active transmission request with MESH (or NULL).
- */
-static struct GNUNET_MESH_TransmitHandle *mesh_th;
-
-/**
- * Head of DLL of requests to be transmitted to mesh_tunnel.
- */
-static struct RequestContext *transmit_queue_head;
-
-/**
- * Tail of DLL of requests to be transmitted to mesh_tunnel.
- */
-static struct RequestContext *transmit_queue_tail;
-
-/**
- * Head of DLL of requests waiting for a response.
- */
-static struct RequestContext *receive_queue_head;
-
-/**
- * Tail of DLL of requests waiting for a response.
- */
-static struct RequestContext *receive_queue_tail;
-
-/**
* Statistics.
*/
static struct GNUNET_STATISTICS_Handle *stats;
@@ -250,12 +318,150 @@
/**
* Number of DNS exit peers we currently have in the mesh tunnel.
- * Used to see if using the mesh tunnel makes any sense right now.
+ * Used to see if using the mesh tunnel makes any sense right now,
+ * as well as to decide if we should open new tunnels.
*/
static unsigned int dns_exit_available;
/**
+ * We are short on mesh exits, try to open another one.
+ */
+static void
+try_open_exit ()
+{
+ struct MeshExit *pos;
+ uint32_t candidate_count;
+ uint32_t candidate_selected;
+
+ candidate_count = 0;
+ for (pos = exit_head; NULL != pos; pos = pos->next)
+ if (NULL == pos->mesh_tunnel)
+ candidate_count++;
+ candidate_selected = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
+ candidate_count);
+ candidate_count = 0;
+ for (pos = exit_head; NULL != pos; pos = pos->next)
+ if (NULL == pos->mesh_tunnel)
+ {
+ candidate_count++;
+ if (candidate_selected < candidate_count)
+ {
+ /* move to the head of the DLL */
+ pos->mesh_tunnel = GNUNET_MESH_tunnel_create (mesh_handle,
+ pos,
+ &pos->peer,
+
GNUNET_APPLICATION_TYPE_INTERNET_RESOLVER,
+ GNUNET_YES /* no buffer
*/,
+ GNUNET_NO /* reliable */);
+ if (NULL == pos->mesh_tunnel)
+ {
+ GNUNET_break (0);
+ continue;
+ }
+ GNUNET_CONTAINER_DLL_remove (exit_head,
+ exit_tail,
+ pos);
+ GNUNET_CONTAINER_DLL_insert (exit_head,
+ exit_tail,
+ pos);
+ dns_exit_available++;
+ return;
+ }
+ }
+ GNUNET_assert (NULL == exit_head);
+}
+
+
+/**
+ * Compute the weight of the given exit. The higher the weight,
+ * the more likely it will be that the tunnel will be chosen.
+ * A weigt of zero means that we should close the tunnel as it
+ * is so bad, that we should not use it.
+ *
+ * @param exit exit to calculate the weight for
+ * @return weight of the tunnel
+ */
+static uint32_t
+get_tunnel_weight (struct MeshExit *exit)
+{
+ uint32_t dropped;
+ uint32_t drop_percent;
+ uint32_t good_percent;
+
+ GNUNET_assert (exit->num_transmitted >= exit->num_answered);
+ dropped = exit->num_transmitted - exit->num_answered;
+ if (exit->num_transmitted > 0)
+ drop_percent = (uint32_t) ((100LL * dropped) / exit->num_transmitted);
+ else
+ drop_percent = 50; /* no data */
+ if ( (exit->num_transmitted > 20) &&
+ (drop_percent > 25) )
+ return 0; /* statistically significant, and > 25% loss, die */
+ good_percent = 100 - drop_percent;
+ GNUNET_assert (0 != good_percent);
+ if ( UINT32_MAX / good_percent / good_percent < exit->num_transmitted)
+ return UINT32_MAX; /* formula below would overflow */
+ return 1 + good_percent * good_percent * exit->num_transmitted;
+}
+
+
+/**
+ * Choose a mesh exit for a DNS request. We try to use a tunnel
+ * that is reliable and currently available. All existing
+ * tunnels are given a base weight of 1, plus a score relating
+ * to the total number of queries answered in relation to the
+ * total number of queries we sent to that tunnel. That
+ * score is doubled if the tunnel is currently idle.
+ *
+ * @return NULL if no exit is known, otherwise the
+ * exit that we should use to queue a message with
+ */
+static struct MeshExit *
+choose_exit ()
+{
+ struct MeshExit *pos;
+ uint64_t total_transmitted;
+ uint64_t selected_offset;
+ uint32_t tunnel_weight;
+
+ total_transmitted = 0;
+ for (pos = exit_head; NULL != pos; pos = pos->next)
+ {
+ if (NULL == pos->mesh_tunnel)
+ break;
+ tunnel_weight = get_tunnel_weight (pos);
+ total_transmitted += tunnel_weight;
+ /* double weight for idle tunnels */
+ if (NULL == pos->mesh_th)
+ total_transmitted += tunnel_weight;
+ }
+ if (0 == total_transmitted)
+ {
+ /* no tunnels available, or only a very bad one... */
+ return exit_head;
+ }
+ selected_offset = GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_WEAK,
+ total_transmitted);
+ total_transmitted = 0;
+ for (pos = exit_head; NULL != pos; pos = pos->next)
+ {
+ if (NULL == pos->mesh_tunnel)
+ break;
+ tunnel_weight = get_tunnel_weight (pos);
+ total_transmitted += tunnel_weight;
+ /* double weight for idle tunnels */
+ if (NULL == pos->mesh_th)
+ total_transmitted += tunnel_weight;
+ if (total_transmitted > selected_offset)
+ return pos;
+ }
+ GNUNET_break (0);
+ return NULL;
+}
+
+
+/**
* We're done modifying all records in the response. Submit the reply
* and free the resources of the rc.
*
@@ -542,7 +748,7 @@
* Transmit a DNS request via MESH and move the request
* handle to the receive queue.
*
- * @param cls NULL
+ * @param cls the `struct MeshExit`
* @param size number of bytes available in buf
* @param buf where to copy the message
* @return number of bytes written to buf
@@ -552,40 +758,41 @@
size_t size,
void *buf)
{
+ struct MeshExit *exit = cls;
struct RequestContext *rc;
size_t mlen;
- mesh_th = NULL;
- if (NULL == (rc = transmit_queue_head))
+ exit->mesh_th = NULL;
+ if (NULL == (rc = exit->transmit_queue_head))
return 0;
- mlen = ntohs (rc->mesh_message->size);
+ mlen = rc->mlen;
if (mlen > size)
{
- mesh_th = GNUNET_MESH_notify_transmit_ready (mesh_tunnel,
- GNUNET_NO,
- TIMEOUT,
- mlen,
- &transmit_dns_request_to_mesh,
- NULL);
+ exit->mesh_th = GNUNET_MESH_notify_transmit_ready (exit->mesh_tunnel,
+ GNUNET_NO,
+ TIMEOUT,
+ mlen,
+
&transmit_dns_request_to_mesh,
+ exit);
return 0;
}
GNUNET_assert (GNUNET_NO == rc->was_transmitted);
memcpy (buf, rc->mesh_message, mlen);
- GNUNET_CONTAINER_DLL_remove (transmit_queue_head,
- transmit_queue_tail,
+ GNUNET_CONTAINER_DLL_remove (exit->transmit_queue_head,
+ exit->transmit_queue_tail,
rc);
rc->was_transmitted = GNUNET_YES;
- GNUNET_CONTAINER_DLL_insert (receive_queue_head,
- receive_queue_tail,
+ GNUNET_CONTAINER_DLL_insert (exit->receive_queue_head,
+ exit->receive_queue_tail,
rc);
- rc = transmit_queue_head;
+ rc = exit->transmit_queue_head;
if (NULL != rc)
- mesh_th = GNUNET_MESH_notify_transmit_ready (mesh_tunnel,
- GNUNET_NO,
- TIMEOUT,
- ntohs (rc->mesh_message->size),
- &transmit_dns_request_to_mesh,
- NULL);
+ exit->mesh_th = GNUNET_MESH_notify_transmit_ready (exit->mesh_tunnel,
+ GNUNET_NO,
+ TIMEOUT,
+ rc->mlen,
+
&transmit_dns_request_to_mesh,
+ exit);
return mlen;
}
@@ -593,7 +800,7 @@
/**
* Task run if the time to answer a DNS request via MESH is over.
*
- * @param cls the 'struct RequestContext' to abort
+ * @param cls the `struct RequestContext` to abort
* @param tc scheduler context
*/
static void
@@ -601,20 +808,52 @@
const struct GNUNET_SCHEDULER_TaskContext *tc)
{
struct RequestContext *rc = cls;
+ struct MeshExit *exit = rc->exit;
if (rc->was_transmitted)
- GNUNET_CONTAINER_DLL_remove (receive_queue_head,
- receive_queue_tail,
+ {
+ exit->num_transmitted++;
+ GNUNET_CONTAINER_DLL_remove (exit->receive_queue_head,
+ exit->receive_queue_tail,
rc);
+ }
else
- GNUNET_CONTAINER_DLL_remove (transmit_queue_head,
- transmit_queue_tail,
+ {
+ GNUNET_CONTAINER_DLL_remove (exit->transmit_queue_head,
+ exit->transmit_queue_tail,
rc);
+ }
GNUNET_STATISTICS_update (stats,
gettext_noop ("# DNS requests dropped (timeout)"),
1, GNUNET_NO);
GNUNET_DNS_request_drop (rc->rh);
GNUNET_free (rc);
+ if ( (0 == get_tunnel_weight (exit)) &&
+ (NULL == exit->receive_queue_head) &&
+ (NULL == exit->transmit_queue_head) )
+ {
+ /* this straw broke the camel's back: this tunnel now has
+ such a low score that it will not be used; close it! */
+ GNUNET_assert (NULL == exit->mesh_th);
+ GNUNET_MESH_tunnel_destroy (exit->mesh_tunnel);
+ exit->mesh_tunnel = NULL;
+ GNUNET_CONTAINER_DLL_remove (exit_head,
+ exit_tail,
+ exit);
+ GNUNET_CONTAINER_DLL_insert_tail (exit_head,
+ exit_tail,
+ exit);
+ /* go back to semi-innocent: mark as not great, but
+ avoid a prohibitively negative score (see
+ #get_tunnel_weight, which checks for a certain
+ minimum number of transmissions before making
+ up an opinion) */
+ exit->num_transmitted = 5;
+ exit->num_answered = 0;
+ dns_exit_available--;
+ /* now try to open an alternative exit */
+ try_open_exit ();
+ }
}
@@ -639,6 +878,7 @@
size_t mlen;
struct GNUNET_MessageHeader hdr;
struct GNUNET_TUN_DnsHeader dns;
+ struct MeshExit *exit;
GNUNET_STATISTICS_update (stats,
gettext_noop ("# DNS requests intercepted"),
@@ -660,49 +900,55 @@
return;
}
memcpy (&dns, request, sizeof (dns));
- GNUNET_assert (NULL != mesh_tunnel);
mlen = sizeof (struct GNUNET_MessageHeader) + request_length;
+ exit = choose_exit ();
+ GNUNET_assert (NULL != exit);
+ GNUNET_assert (NULL != exit->mesh_tunnel);
rc = GNUNET_malloc (sizeof (struct RequestContext) + mlen);
+ rc->exit = exit;
rc->rh = rh;
rc->mesh_message = (const struct GNUNET_MessageHeader*) &rc[1];
rc->timeout_task = GNUNET_SCHEDULER_add_delayed (TIMEOUT,
&timeout_request,
rc);
rc->dns_id = dns.id;
+ rc->mlen = mlen;
hdr.type = htons (GNUNET_MESSAGE_TYPE_VPN_DNS_TO_INTERNET);
hdr.size = htons (mlen);
memcpy (&rc[1], &hdr, sizeof (struct GNUNET_MessageHeader));
memcpy (&(((char*)&rc[1])[sizeof (struct GNUNET_MessageHeader)]),
request,
request_length);
- GNUNET_CONTAINER_DLL_insert_tail (transmit_queue_head,
- transmit_queue_tail,
+ GNUNET_CONTAINER_DLL_insert_tail (exit->transmit_queue_head,
+ exit->transmit_queue_tail,
rc);
- if (NULL == mesh_th)
- mesh_th = GNUNET_MESH_notify_transmit_ready (mesh_tunnel,
- GNUNET_NO,
- TIMEOUT,
- mlen,
- &transmit_dns_request_to_mesh,
- NULL);
+ if (NULL == exit->mesh_th)
+ exit->mesh_th = GNUNET_MESH_notify_transmit_ready (exit->mesh_tunnel,
+ GNUNET_NO,
+ TIMEOUT,
+ mlen,
+
&transmit_dns_request_to_mesh,
+ exit);
}
/**
* Process a request via mesh to perform a DNS query.
*
- * @param cls closure, NULL
+ * @param cls NULL
* @param tunnel connection to the other end
- * @param tunnel_ctx FIXME
+ * @param tunnel_ctx pointer to our `struct MeshExit`
* @param message the actual message
* @return #GNUNET_OK to keep the connection open,
* #GNUNET_SYSERR to close it (signal serious error)
*/
static int
-receive_dns_response (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel
*tunnel,
+receive_dns_response (void *cls,
+ struct GNUNET_MESH_Tunnel *tunnel,
void **tunnel_ctx,
const struct GNUNET_MessageHeader *message)
{
+ struct MeshExit *exit = *tunnel_ctx;
struct GNUNET_TUN_DnsHeader dns;
size_t mlen;
struct RequestContext *rc;
@@ -715,7 +961,7 @@
return GNUNET_SYSERR;
}
memcpy (&dns, &message[1], sizeof (dns));
- for (rc = receive_queue_head; NULL != rc; rc = rc->next)
+ for (rc = exit->receive_queue_head; NULL != rc; rc = rc->next)
{
GNUNET_assert (GNUNET_YES == rc->was_transmitted);
if (dns.id == rc->dns_id)
@@ -726,11 +972,13 @@
GNUNET_DNS_request_answer (rc->rh,
mlen,
(const void*) &message[1]);
- GNUNET_CONTAINER_DLL_remove (receive_queue_head,
- receive_queue_tail,
+ GNUNET_CONTAINER_DLL_remove (exit->receive_queue_head,
+ exit->receive_queue_tail,
rc);
GNUNET_SCHEDULER_cancel (rc->timeout_task);
GNUNET_free (rc);
+ exit->num_answered++;
+ exit->num_transmitted++;
return GNUNET_OK;
}
}
@@ -742,33 +990,28 @@
/**
- * The MESH DNS tunnel went down. Abort all pending DNS
- * requests (we're unlikely to get an answer in time).
+ * Abort all pending DNS requests with the given mesh exit.
+ *
+ * @param exit mesh exit to abort requests for
*/
static void
-abort_all_requests ()
+abort_all_requests (struct MeshExit *exit)
{
struct RequestContext *rc;
- while (NULL != (rc = receive_queue_head))
+ while (NULL != (rc = exit->receive_queue_head))
{
- GNUNET_STATISTICS_update (stats,
- gettext_noop ("# DNS requests aborted (tunnel
down)"),
- 1, GNUNET_NO);
- GNUNET_CONTAINER_DLL_remove (receive_queue_head,
- receive_queue_tail,
+ GNUNET_CONTAINER_DLL_remove (exit->receive_queue_head,
+ exit->receive_queue_tail,
rc);
GNUNET_DNS_request_drop (rc->rh);
GNUNET_SCHEDULER_cancel (rc->timeout_task);
GNUNET_free (rc);
}
- while (NULL != (rc = transmit_queue_head))
+ while (NULL != (rc = exit->transmit_queue_head))
{
- GNUNET_STATISTICS_update (stats,
- gettext_noop ("# DNS requests aborted (tunnel
down)"),
- 1, GNUNET_NO);
- GNUNET_CONTAINER_DLL_remove (transmit_queue_head,
- transmit_queue_tail,
+ GNUNET_CONTAINER_DLL_remove (exit->transmit_queue_head,
+ exit->transmit_queue_tail,
rc);
GNUNET_DNS_request_drop (rc->rh);
GNUNET_SCHEDULER_cancel (rc->timeout_task);
@@ -787,6 +1030,8 @@
cleanup (void *cls,
const struct GNUNET_SCHEDULER_TaskContext *tskctx)
{
+ struct MeshExit *exit;
+
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Protocol translation daemon is shutting down now\n");
if (NULL != vpn_handle)
@@ -794,22 +1039,29 @@
GNUNET_VPN_disconnect (vpn_handle);
vpn_handle = NULL;
}
- if (NULL != mesh_th)
+ while (NULL != (exit = exit_head))
{
- GNUNET_MESH_notify_transmit_ready_cancel (mesh_th);
- mesh_th = NULL;
+ GNUNET_CONTAINER_DLL_remove (exit_head,
+ exit_tail,
+ exit);
+ if (NULL != exit->mesh_th)
+ {
+ GNUNET_MESH_notify_transmit_ready_cancel (exit->mesh_th);
+ exit->mesh_th = NULL;
+ }
+ if (NULL != exit->mesh_tunnel)
+ {
+ GNUNET_MESH_tunnel_destroy (exit->mesh_tunnel);
+ exit->mesh_tunnel = NULL;
+ }
+ abort_all_requests (exit);
+ GNUNET_free (exit);
}
- if (NULL != mesh_tunnel)
- {
- GNUNET_MESH_tunnel_destroy (mesh_tunnel);
- mesh_tunnel = NULL;
- }
if (NULL != mesh_handle)
{
GNUNET_MESH_disconnect (mesh_handle);
mesh_handle = NULL;
}
- abort_all_requests ();
if (NULL != dns_post_handle)
{
GNUNET_DNS_disconnect (dns_post_handle);
@@ -838,14 +1090,13 @@
}
-
/**
* Function called whenever a tunnel is destroyed. Should clean up
* the associated state and attempt to build a new one.
*
* It must NOT call #GNUNET_MESH_tunnel_destroy on the tunnel.
*
- * @param cls closure (set from #GNUNET_MESH_connect)
+ * @param cls closure (the `struct MeshExit` set from #GNUNET_MESH_connect)
* @param tunnel connection to the other end (henceforth invalid)
* @param tunnel_ctx place where local state associated
* with the tunnel is stored
@@ -855,7 +1106,59 @@
const struct GNUNET_MESH_Tunnel *tunnel,
void *tunnel_ctx)
{
- // FIXME: do cleanup here!
+ struct MeshExit *exit = tunnel_ctx;
+ struct MeshExit *alt;
+ struct RequestContext *rc;
+
+ if (NULL != exit->mesh_th)
+ {
+ GNUNET_MESH_notify_transmit_ready_cancel (exit->mesh_th);
+ exit->mesh_th = NULL;
+ }
+ exit->mesh_tunnel = NULL;
+ dns_exit_available--;
+ /* open alternative tunnels */
+ try_open_exit ();
+ if (NULL == exit->mesh_tunnel)
+ {
+ /* our tunnel is now closed, move our requests to an alternative
+ tunnel */
+ alt = choose_exit ();
+ while (NULL != (rc = exit->transmit_queue_head))
+ {
+ GNUNET_CONTAINER_DLL_remove (exit->transmit_queue_head,
+ exit->transmit_queue_tail,
+ rc);
+ rc->exit = alt;
+ GNUNET_CONTAINER_DLL_insert (alt->transmit_queue_head,
+ alt->transmit_queue_tail,
+ rc);
+ }
+ while (NULL != (rc = exit->receive_queue_head))
+ {
+ GNUNET_CONTAINER_DLL_remove (exit->receive_queue_head,
+ exit->receive_queue_tail,
+ rc);
+ rc->was_transmitted = GNUNET_NO;
+ rc->exit = alt;
+ GNUNET_CONTAINER_DLL_insert (alt->transmit_queue_head,
+ alt->transmit_queue_tail,
+ rc);
+ }
+ }
+ else
+ {
+ /* the same peer was chosen, just make sure the queue processing is
restarted */
+ alt = exit;
+ }
+ if ( (NULL == alt->mesh_th) &&
+ (NULL != (rc = alt->transmit_queue_head)) )
+ alt->mesh_th = GNUNET_MESH_notify_transmit_ready (alt->mesh_tunnel,
+ GNUNET_NO,
+ TIMEOUT,
+ rc->mlen,
+
&transmit_dns_request_to_mesh,
+ alt);
}
@@ -891,6 +1194,7 @@
{
const struct GNUNET_DNS_Advertisement *ad;
struct GNUNET_PeerIdentity pid;
+ struct MeshExit *exit;
if (sizeof (struct GNUNET_DNS_Advertisement) != size)
{
@@ -901,15 +1205,24 @@
GNUNET_CRYPTO_hash (&ad->peer,
sizeof (struct GNUNET_CRYPTO_EccPublicSignKey),
&pid.hashPubKey);
- /* FIXME: decide between creating more mesh tunnels and
- just remembering the peer ID */
- mesh_tunnel = GNUNET_MESH_tunnel_create (mesh_handle,
- NULL /* FIXME: tunnel ctx */,
- &pid,
-
GNUNET_APPLICATION_TYPE_INTERNET_RESOLVER,
- GNUNET_YES /* no buffer */,
- GNUNET_NO /* reliable */);
-
+ for (exit = exit_head; NULL != exit; exit = exit->next)
+ if (0 == memcmp (&pid,
+ &exit->peer,
+ sizeof (struct GNUNET_PeerIdentity)))
+ break;
+ if (NULL == exit)
+ {
+ exit = GNUNET_new (struct MeshExit);
+ exit->peer = pid;
+ /* tunnel is closed, so insert at the end */
+ GNUNET_CONTAINER_DLL_insert_tail (exit_head,
+ exit_tail,
+ exit);
+ }
+ exit->expiration = GNUNET_TIME_absolute_max (exit->expiration,
+ GNUNET_TIME_absolute_ntoh
(ad->expiration_time));
+ if (dns_exit_available < MAX_OPEN_TUNNELS)
+ try_open_exit ();
}
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- [GNUnet-SVN] r29472 - in gnunet/src: include pt,
gnunet <=