#include "gnunet_applications.h"
#include "block_dns.h"
-#define PORT_PT 4242 // FIXME
-
/**
* After how long do we time out if we could not get an IP from VPN or MESH?
*/
#define TIMEOUT GNUNET_TIME_UNIT_MINUTES
-
/**
* How many bytes of payload do we allow at most for a DNS reply?
* Given that this is pretty much limited to loopback, we can be
*/
#define MAX_DNS_SIZE (8 * 1024)
+/**
+ * How many channels do we open at most at the same time?
+ */
+#define MAX_OPEN_TUNNELS 4
+
/**
* Which group of DNS records are we currently processing?
/**
* DNS answers
*/
- ANSWERS = 0,
+ ANSWERS = 0,
/**
* DNS authority records
* Handle to submit the final result.
*/
struct GNUNET_DNS_RequestHandle *rh;
-
+
/**
* DNS packet that is being modified.
*/
* Group that is being modified
*/
enum RequestGroup group;
-
+
+};
+
+
+/**
+ * Handle to a peer that advertised that it is willing to serve
+ * as a DNS exit. We try to keep a few channels open and a few
+ * peers in reserve.
+ */
+struct MeshExit
+{
+
+ /**
+ * Kept in a DLL.
+ */
+ struct MeshExit *next;
+
+ /**
+ * Kept in a DLL.
+ */
+ struct MeshExit *prev;
+
+ /**
+ * Channel we use for DNS requests over MESH, NULL if we did
+ * not initialze a channel to this peer yet.
+ */
+ struct GNUNET_MESH_Channel *mesh_channel;
+
+ /**
+ * 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_channel.
+ */
+ struct RequestContext *transmit_queue_head;
+
+ /**
+ * Tail of DLL of requests to be transmitted to a mesh_channel.
+ */
+ struct RequestContext *transmit_queue_tail;
+
+ /**
+ * Active transmission request for this channel (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 channel?
+ */
+ unsigned int num_transmitted;
+
+ /**
+ * How many DNS requests were answered via this channel?
+ */
+ unsigned int num_answered;
+
};
+
/**
* State we keep for a request that is going out via MESH.
*/
*/
struct RequestContext *prev;
+ /**
+ * Exit that was chosen for this request.
+ */
+ struct MeshExit *exit;
+
/**
* Handle for interaction with DNS service.
*/
struct GNUNET_DNS_RequestHandle *rh;
-
+
/**
* Message we're sending out via MESH, allocated at the
* end of this struct.
*/
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).
*/
/**
* #GNUNET_NO if this request is still in the transmit_queue,
* #GNUNET_YES if we are in the receive_queue.
- */
+ */
int16_t was_transmitted;
};
/**
- * The handle to the configuration used throughout the process
+ * Head of DLL of mesh exits. Mesh exits with an open channel are
+ * always at the beginning (so we do not have to traverse the entire
+ * list to find them).
*/
-static const struct GNUNET_CONFIGURATION_Handle *cfg;
+static struct MeshExit *exit_head;
/**
- * The handle to the VPN
+ * Tail of DLL of mesh exits.
*/
-static struct GNUNET_VPN_Handle *vpn_handle;
+static struct MeshExit *exit_tail;
/**
- * The handle to the MESH service
- */
-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.
+ * The handle to the configuration used throughout the process
*/
-static struct RequestContext *transmit_queue_tail;
+static const struct GNUNET_CONFIGURATION_Handle *cfg;
/**
- * Head of DLL of requests waiting for a response.
+ * The handle to the VPN
*/
-static struct RequestContext *receive_queue_head;
+static struct GNUNET_VPN_Handle *vpn_handle;
/**
- * Tail of DLL of requests waiting for a response.
+ * The handle to the MESH service
*/
-static struct RequestContext *receive_queue_tail;
+static struct GNUNET_MESH_Handle *mesh_handle;
/**
* Statistics.
static int ipv6_pt;
/**
- * Are we tunneling DNS queries?
+ * Are we channeling DNS queries?
*/
-static int dns_tunnel;
+static int dns_channel;
/**
- * 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.
+ * Number of DNS exit peers we currently have in the mesh channel.
+ * Used to see if using the mesh channel makes any sense right now,
+ * as well as to decide if we should open new channels.
*/
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_channel)
+ 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_channel)
+ {
+ candidate_count++;
+ if (candidate_selected < candidate_count)
+ {
+ /* move to the head of the DLL */
+ pos->mesh_channel = GNUNET_MESH_channel_create (mesh_handle,
+ pos,
+ &pos->peer,
+ GNUNET_APPLICATION_TYPE_INTERNET_RESOLVER,
+ GNUNET_MESH_OPTION_DEFAULT);
+ if (NULL == pos->mesh_channel)
+ {
+ 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 channel will be chosen.
+ * A weigt of zero means that we should close the channel as it
+ * is so bad, that we should not use it.
+ *
+ * @param exit exit to calculate the weight for
+ * @return weight of the channel
+ */
+static uint32_t
+get_channel_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 channel
+ * that is reliable and currently available. All existing
+ * channels 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 channel. That
+ * score is doubled if the channel 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 channel_weight;
+
+ total_transmitted = 0;
+ for (pos = exit_head; NULL != pos; pos = pos->next)
+ {
+ if (NULL == pos->mesh_channel)
+ break;
+ channel_weight = get_channel_weight (pos);
+ total_transmitted += channel_weight;
+ /* double weight for idle channels */
+ if (NULL == pos->mesh_th)
+ total_transmitted += channel_weight;
+ }
+ if (0 == total_transmitted)
+ {
+ /* no channels 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_channel)
+ break;
+ channel_weight = get_channel_weight (pos);
+ total_transmitted += channel_weight;
+ /* double weight for idle channels */
+ if (NULL == pos->mesh_th)
+ total_transmitted += channel_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.
* record and then continue with 'submit_request' to look at
* the other records.
*
- * @param cls our 'struct ReplyContext'
+ * @param cls our `struct ReplyContext`
* @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
+ * traffic to this IP will now be redirected to the
* specified target peer; NULL on error
*/
static void
/**
- * Modify the given DNS record by asking VPN to create a tunnel
+ * Modify the given DNS record by asking VPN to create a channel
* to the given address. When done, continue with submitting
* other records from the request context ('submit_request' is
* our continuation).
rc->rr = GNUNET_VPN_redirect_to_ip (vpn_handle,
af, af,
rec->data.raw.data,
- GNUNET_NO /* nac */,
GNUNET_TIME_relative_to_absolute (TIMEOUT),
&vpn_allocation_callback,
rc);
finish_request (rc);
return;
default:
- GNUNET_assert (0);
+ GNUNET_assert (0);
}
for (i=rc->offset;i<ra_len;i++)
{
* Test if any of the given records need protocol-translation work.
*
* @param ra array of records
- * @param ra_len number of entries in ra
- * @return GNUNET_YES if any of the given records require protocol-translation
+ * @param ra_len number of entries in @a ra
+ * @return #GNUNET_YES if any of the given records require protocol-translation
*/
static int
work_test (const struct GNUNET_DNSPARSER_Record *ra,
/**
- * This function is called AFTER we got an IP address for a
+ * This function is called AFTER we got an IP address for a
* DNS request. Now, the PT daemon has the chance to substitute
- * the IP address with one from the VPN range to tunnel requests
+ * the IP address with one from the VPN range to channel requests
* destined for this IP address via VPN and MESH.
*
* @param cls closure
* @param request_length number of bytes in request
* @param request udp payload of the DNS request
*/
-static void
+static void
dns_post_request_handler (void *cls,
struct GNUNET_DNS_RequestHandle *rh,
size_t request_length,
* 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
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_channel,
+ 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_channel,
+ GNUNET_NO,
+ TIMEOUT,
+ rc->mlen,
+ &transmit_dns_request_to_mesh,
+ exit);
return mlen;
}
/**
* 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
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_channel_weight (exit)) &&
+ (NULL == exit->receive_queue_head) &&
+ (NULL == exit->transmit_queue_head) )
+ {
+ /* this straw broke the camel's back: this channel now has
+ such a low score that it will not be used; close it! */
+ GNUNET_assert (NULL == exit->mesh_th);
+ GNUNET_MESH_channel_destroy (exit->mesh_channel);
+ exit->mesh_channel = 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_channel_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 ();
+ }
}
/**
- * This function is called *before* the DNS request has been
- * given to a "local" DNS resolver. Tunneling for DNS requests
+ * This function is called *before* the DNS request has been
+ * given to a "local" DNS resolver. Channeling for DNS requests
* was enabled, so we now need to send the request via some MESH
- * tunnel to a DNS EXIT for resolution.
+ * channel to a DNS EXIT for resolution.
*
* @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
+static void
dns_pre_request_handler (void *cls,
struct GNUNET_DNS_RequestHandle *rh,
size_t request_length,
size_t mlen;
struct GNUNET_MessageHeader hdr;
struct GNUNET_TUN_DnsHeader dns;
+ struct MeshExit *exit;
GNUNET_STATISTICS_update (stats,
gettext_noop ("# DNS requests intercepted"),
if (0 == dns_exit_available)
{
GNUNET_STATISTICS_update (stats,
- gettext_noop ("# DNS requests dropped (DNS mesh tunnel down)"),
+ gettext_noop ("# DNS requests dropped (DNS mesh channel down)"),
1, GNUNET_NO);
GNUNET_DNS_request_drop (rh);
return;
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_channel);
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_channel,
+ 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 tunnel connection to the other end
- * @param tunnel_ctx pointer to our 'struct TunnelState *'
+ * @param cls NULL
+ * @param channel connection to the other end
+ * @param channel_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)
+ * @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,
- void **tunnel_ctx,
+receive_dns_response (void *cls,
+ struct GNUNET_MESH_Channel *channel,
+ void **channel_ctx,
const struct GNUNET_MessageHeader *message)
{
+ struct MeshExit *exit = *channel_ctx;
struct GNUNET_TUN_DnsHeader dns;
size_t mlen;
struct RequestContext *rc;
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)
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);
- return GNUNET_OK;
+ exit->num_answered++;
+ exit->num_transmitted++;
+ return GNUNET_OK;
}
}
GNUNET_STATISTICS_update (stats,
/**
- * 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);
+ 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);
- GNUNET_free (rc);
+ GNUNET_free (rc);
}
}
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)
GNUNET_VPN_disconnect (vpn_handle);
vpn_handle = NULL;
}
- if (NULL != mesh_th)
- {
- GNUNET_MESH_notify_transmit_ready_cancel (mesh_th);
- mesh_th = NULL;
- }
- if (NULL != mesh_tunnel)
+ while (NULL != (exit = exit_head))
{
- GNUNET_MESH_tunnel_destroy (mesh_tunnel);
- mesh_tunnel = 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_channel)
+ {
+ GNUNET_MESH_channel_destroy (exit->mesh_channel);
+ exit->mesh_channel = NULL;
+ }
+ abort_all_requests (exit);
+ GNUNET_free (exit);
}
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);
}
-
/**
- * Function called whenever a tunnel is destroyed. Should clean up
+ * Function called whenever a channel 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 tunnel connection to the other end (henceforth invalid)
- * @param tunnel_ctx place where local state associated
- * with the tunnel is stored
+ * It must NOT call #GNUNET_MESH_channel_destroy on the channel.
+ *
+ * @param cls closure (the `struct MeshExit` set from #GNUNET_MESH_connect)
+ * @param channel connection to the other end (henceforth invalid)
+ * @param channel_ctx place where local state associated
+ * with the channel is stored
*/
static void
-mesh_tunnel_end_cb (void *cls,
- const struct GNUNET_MESH_Tunnel *tunnel,
- void *tunnel_ctx)
+mesh_channel_end_cb (void *cls,
+ const struct GNUNET_MESH_Channel *channel,
+ void *channel_ctx)
{
- // FIXME: do cleanup here!
+ struct MeshExit *exit = channel_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_channel = NULL;
+ dns_exit_available--;
+ /* open alternative channels */
+ try_open_exit ();
+ if (NULL == exit->mesh_channel)
+ {
+ /* our channel is now closed, move our requests to an alternative
+ channel */
+ 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_channel,
+ GNUNET_NO,
+ TIMEOUT,
+ rc->mlen,
+ &transmit_dns_request_to_mesh,
+ alt);
}
/**
- * Function called whenever we find an advertisement for a
- * DNS exit in the DHT. If we don't have a mesh tunnel,
+ * Function called whenever we find an advertisement for a
+ * DNS exit in the DHT. If we don't have a mesh channel,
* we should build one; otherwise, we should save the
* advertisement for later use.
*
handle_dht_result (void *cls,
struct GNUNET_TIME_Absolute exp,
const struct GNUNET_HashCode *key,
- const struct GNUNET_PeerIdentity *get_path,
+ const struct GNUNET_PeerIdentity *get_path,
unsigned int get_path_length,
const struct GNUNET_PeerIdentity *put_path,
unsigned int put_path_length,
size_t size, const void *data)
{
const struct GNUNET_DNS_Advertisement *ad;
- struct GNUNET_PeerIdentity pid;
+ struct MeshExit *exit;
if (sizeof (struct GNUNET_DNS_Advertisement) != size)
{
return;
}
ad = data;
- 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,
- PORT_PT, /* FIXME: DNS port, right? */
- GNUNET_YES /* no buffer */,
- GNUNET_NO /* reliable */);
-
+ for (exit = exit_head; NULL != exit; exit = exit->next)
+ if (0 == memcmp (&ad->peer,
+ &exit->peer,
+ sizeof (struct GNUNET_PeerIdentity)))
+ break;
+ if (NULL == exit)
+ {
+ exit = GNUNET_new (struct MeshExit);
+ exit->peer = ad->peer;
+ /* channel 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 ();
}
cfg = cfg_;
stats = GNUNET_STATISTICS_create ("pt", cfg);
ipv4_pt = GNUNET_CONFIGURATION_get_value_yesno (cfg, "pt", "TUNNEL_IPV4");
- ipv6_pt = GNUNET_CONFIGURATION_get_value_yesno (cfg, "pt", "TUNNEL_IPV6");
- dns_tunnel = GNUNET_CONFIGURATION_get_value_yesno (cfg, "pt", "TUNNEL_DNS");
- if (! (ipv4_pt || ipv6_pt || dns_tunnel))
+ ipv6_pt = GNUNET_CONFIGURATION_get_value_yesno (cfg, "pt", "TUNNEL_IPV6");
+ dns_channel = GNUNET_CONFIGURATION_get_value_yesno (cfg, "pt", "TUNNEL_DNS");
+ if (! (ipv4_pt || ipv6_pt || dns_channel))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
_("No useful service enabled. Exiting.\n"));
GNUNET_SCHEDULER_shutdown ();
- return;
+ return;
}
GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL, &cleanup, cls);
if (ipv4_pt || ipv6_pt)
{
- dns_post_handle
- = GNUNET_DNS_connect (cfg,
+ dns_post_handle
+ = GNUNET_DNS_connect (cfg,
GNUNET_DNS_FLAG_POST_RESOLUTION,
&dns_post_request_handler, NULL);
- if (NULL == dns_post_handle)
+ if (NULL == dns_post_handle)
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
_("Failed to connect to %s service. Exiting.\n"),
return;
}
}
- if (dns_tunnel)
+ if (dns_channel)
{
static struct GNUNET_MESH_MessageHandler mesh_handlers[] = {
{&receive_dns_response, GNUNET_MESSAGE_TYPE_VPN_DNS_FROM_INTERNET, 0},
{NULL, 0, 0}
};
- dns_pre_handle
- = GNUNET_DNS_connect (cfg,
+ dns_pre_handle
+ = GNUNET_DNS_connect (cfg,
GNUNET_DNS_FLAG_PRE_RESOLUTION,
&dns_pre_request_handler, NULL);
- if (NULL == dns_pre_handle)
+ if (NULL == dns_pre_handle)
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
_("Failed to connect to %s service. Exiting.\n"),
return;
}
mesh_handle = GNUNET_MESH_connect (cfg, NULL, NULL,
- &mesh_tunnel_end_cb,
+ &mesh_channel_end_cb,
mesh_handlers, NULL);
if (NULL == mesh_handle)
{
projects / oweals / gnunet.git / blobdiff