-finishing first implementation of VPN client library

1 files changed, 336 insertions, 7 deletions

diff --git a/src/vpn/vpn_api.c b/src/vpn/vpn_api.c
index b6fab37bf..f7759a3bc 100644
--- a/src/vpn/vpn_api.c
+++ b/src/vpn/vpn_api.c
@@ -44,6 +44,11 @@ struct GNUNET_VPN_Handle
   struct GNUNET_CLIENT_Connection *client;
 
   /**
+   * Active transmission request.
+   */
+  struct GNUNET_CLIENT_TransmitHandle *th;
+
+  /**
    * Head of list of active redirection requests.
    */
   struct GNUNET_VPN_RedirectionRequest *rr_head;
@@ -52,6 +57,17 @@ struct GNUNET_VPN_Handle
    * Tail of list of active redirection requests.
    */
   struct GNUNET_VPN_RedirectionRequest *rr_tail;
+
+  /**
+   * Identifier of a reconnect task.
+   */
+  GNUNET_SCHEDULER_TaskIdentifier rt;
+
+  /**
+   * ID of the last request that was submitted to the service.
+   */
+  uint64_t request_id_gen;
+
 };
 
 
@@ -107,6 +123,11 @@ struct GNUNET_VPN_RedirectionRequest
   struct GNUNET_TIME_Absolute expiration_time;
 
   /**
+   * non-zero if this request has been sent to the service.
+   */
+  uint64_t request_id;
+
+  /**
    * Desired address family for the result.
    */
   int result_af;
@@ -131,6 +152,255 @@ struct GNUNET_VPN_RedirectionRequest
 
 
 /**
+ * Disconnect from the service (communication error) and reconnect later.
+ *
+ * @param vh handle to reconnect.
+ */
+static void
+reconnect (struct GNUNET_VPN_Handle *vh);
+
+
+/**
+ * Function called when we receive a message from the VPN service.
+ *
+ * @param cls the 'struct GNUNET_VPN_Handle'
+ * @param msg message received, NULL on timeout or fatal error
+ */
+static void 
+receive_response (void *cls,
+                  const struct GNUNET_MessageHeader* msg)
+{
+  struct GNUNET_VPN_Handle *vh = cls;
+  const struct RedirectToIpResponseMessage *rm;
+  struct GNUNET_VPN_RedirectionRequest *rr;
+  size_t msize;
+  size_t alen;
+  int af;
+
+  if (NULL == msg) 
+  {
+    reconnect (vh);
+    return;
+  }
+  if ( (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_VPN_CLIENT_USE_IP) ||
+       (sizeof (struct RedirectToIpResponseMessage) > (msize = ntohs (msg->size))) )
+  {
+    GNUNET_break (0);
+    reconnect (vh);
+    return;
+  }
+  rm = (const struct RedirectToIpResponseMessage *) msg;
+  af = (int) ntohl (rm->result_af);
+  switch (af)
+  {
+  case AF_UNSPEC:
+    alen = 0;
+    break;
+  case AF_INET:
+    alen = sizeof (struct in_addr);
+    break;
+  case AF_INET6:
+    alen = sizeof (struct in6_addr);
+    break;
+  default:
+    GNUNET_break (0);
+    reconnect (vh);
+    return;
+  }
+  if ( (msize != alen + sizeof (struct RedirectToIpResponseMessage)) ||
+       (0 == rm->request_id) )
+  {
+    GNUNET_break (0);
+    reconnect (vh);
+    return;
+  }  
+  for (rr = vh->rr_head; NULL != rr; rr = rr->next)
+  {
+    if (rr->request_id == rm->request_id)
+    {
+      GNUNET_CONTAINER_DLL_remove (vh->rr_head,
+                                   vh->rr_tail,
+                                   rr);
+      rr->cb (rr->cb_cls,
+              af,
+              (af == AF_UNSPEC) ? NULL : &rm[1]);
+      GNUNET_free (rr);
+      break;
+    }
+  }
+  GNUNET_CLIENT_receive (vh->client,
+                         &receive_response, vh,
+                         GNUNET_TIME_UNIT_FOREVER_REL);      
+}
+
+
+/**
+ * We're ready to transmit a request to the VPN service. Do it.
+ *
+ * @param cls the 'struct GNUNET_VPN_Handle*'
+ * @param size number of bytes available in buf
+ * @param buf where to copy the request
+ * @return number of bytes copied to 'buf'
+ */
+static size_t
+transmit_request (void *cls,
+                  size_t size,
+                  void *buf)
+{
+  struct GNUNET_VPN_Handle *vh = cls;
+  struct GNUNET_VPN_RedirectionRequest *rr;
+  struct RedirectToIpRequestMessage rip;
+  struct RedirectToServiceRequestMessage rs;
+  char *cbuf;
+  size_t alen;
+  size_t ret;
+
+  vh->th = NULL;
+  /* find a pending request */
+  rr = vh->rr_head;
+  while ( (NULL != rr) &&
+          (0 != rr->request_id) )
+    rr = rr->next;
+  if (NULL == rr)
+    return 0;
+
+  /* if first request, start receive loop */
+  if (0 == vh->request_id_gen)
+    GNUNET_CLIENT_receive (vh->client,
+                           &receive_response, vh,
+                           GNUNET_TIME_UNIT_FOREVER_REL); 
+  if (NULL == rr->addr)
+  {
+    ret = sizeof (struct RedirectToServiceRequestMessage);
+    rs.header.size = htons ((uint16_t) ret);
+    rs.header.type = htons (GNUNET_MESSAGE_TYPE_VPN_CLIENT_REDIRECT_TO_SERVICE);
+    rs.nac = htonl (rr->nac);
+    rs.expiration_time = GNUNET_TIME_absolute_hton (rr->expiration_time);
+    rs.protocol = htonl (rr->protocol);
+    rs.result_af = htonl (rr->result_af);
+    rs.target = rr->peer;
+    rs.service_descriptor = rr->serv;
+    rs.request_id = rr->request_id = ++vh->request_id_gen;    
+    memcpy (buf, &rs, sizeof (struct RedirectToServiceRequestMessage));
+  }
+  else
+  {
+    switch (rr->addr_af)
+    {
+    case AF_INET:
+      alen = sizeof (struct in_addr);
+      break;
+    case AF_INET6:
+      alen = sizeof (struct in6_addr);
+      break;
+    default:
+      GNUNET_assert (0);
+      return 0;
+    }
+    ret = alen + sizeof (struct RedirectToIpRequestMessage);
+    rip.header.size = htons ((uint16_t) ret);
+    rip.header.type = htons (GNUNET_MESSAGE_TYPE_VPN_CLIENT_REDIRECT_TO_IP);
+    rip.nac = htonl (rr->nac);
+    rip.expiration_time = GNUNET_TIME_absolute_hton (rr->expiration_time);
+    rip.result_af = htonl (rr->result_af);
+    rip.addr_af = htonl (rr->addr_af);
+    rip.request_id = rr->request_id = ++vh->request_id_gen;
+    cbuf = buf;
+    memcpy (cbuf, &rip, sizeof (struct RedirectToIpRequestMessage));
+    memcpy (&cbuf[sizeof (struct RedirectToIpRequestMessage)], rr->addr, alen);
+  }
+  /* test if there are more pending requests */
+  while ( (NULL != rr) &&
+          (0 != rr->request_id) )
+    rr = rr->next;
+  if (NULL != rr)
+    vh->th = GNUNET_CLIENT_notify_transmit_ready (vh->client,
+                                                  sizeof (struct RedirectToServiceRequestMessage),
+                                                  GNUNET_TIME_UNIT_FOREVER_REL,
+                                                  GNUNET_NO,
+                                                  &transmit_request,
+                                                  vh);
+  return ret;
+}
+
+
+/**
+ * Add a request to our request queue and transmit it.
+ * 
+ * @param rr request to queue and transmit.
+ */
+static void
+queue_request (struct GNUNET_VPN_RedirectionRequest *rr)
+{
+  struct GNUNET_VPN_Handle *vh;
+
+  vh = rr->vh;
+  GNUNET_CONTAINER_DLL_insert_tail (vh->rr_head,
+                                    vh->rr_tail,
+                                    rr);
+  if ( (NULL == vh->th) &&
+       (NULL != vh->client) )
+    vh->th = GNUNET_CLIENT_notify_transmit_ready (vh->client,
+                                                  sizeof (struct RedirectToServiceRequestMessage),
+                                                  GNUNET_TIME_UNIT_FOREVER_REL,
+                                                  GNUNET_NO,
+                                                  &transmit_request,
+                                                  vh);
+}
+
+
+/**
+ * Connect to the VPN service and start again to transmit our requests.
+ *
+ * @param cls the 'struct GNUNET_VPN_Handle *'
+ * @param tc scheduler context
+ */
+static void
+connect_task (void *cls,
+              const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+  struct GNUNET_VPN_Handle *vh = cls;
+  
+  vh->client = GNUNET_CLIENT_connect ("vpn", vh->cfg);
+  GNUNET_assert (NULL != vh->client);
+  GNUNET_assert (NULL != vh->th);
+  if (NULL != vh->rr_head) 
+    vh->th = GNUNET_CLIENT_notify_transmit_ready (vh->client,
+                                                  sizeof (struct RedirectToServiceRequestMessage),
+                                                  GNUNET_TIME_UNIT_FOREVER_REL,
+                                                  GNUNET_NO,
+                                                  &transmit_request,
+                                                  vh);
+}
+
+
+/**
+ * Disconnect from the service (communication error) and reconnect later.
+ *
+ * @param vh handle to reconnect.
+ */
+static void
+reconnect (struct GNUNET_VPN_Handle *vh)
+{
+  struct GNUNET_VPN_RedirectionRequest *rr;
+
+  if (NULL != vh->th)
+  {
+    GNUNET_CLIENT_notify_transmit_ready_cancel (vh->th);
+    vh->th = NULL;
+  }  
+  GNUNET_CLIENT_disconnect (vh->client, GNUNET_NO);
+  vh->client = NULL;
+  vh->request_id_gen = 0;
+  for (rr = vh->rr_head; NULL != rr; rr = rr->next)
+    rr->request_id = 0;
+  vh->rt = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
+                                         &connect_task, 
+                                         vh);
+}
+
+
+/**
  * Cancel redirection request with the service.
  *
  * @param rr request to cancel
@@ -157,7 +427,8 @@ GNUNET_VPN_cancel_request (struct GNUNET_VPN_RedirectionRequest *rr)
  * limitations, the longest inactive mappings will be destroyed.
  *
  * @param vh VPN handle
- * @param af address family, AF_INET or AF_INET6
+ * @param result_af desired address family for the returned allocation
+ *                  can also be AF_UNSPEC
  * @param protocol protocol, IPPROTO_UDP or IPPROTO_TCP
  * @param peer target peer for the redirection
  * @param serv service descriptor to give to the peer
@@ -173,8 +444,8 @@ GNUNET_VPN_cancel_request (struct GNUNET_VPN_RedirectionRequest *rr)
  *         anyway)
  */
 struct GNUNET_VPN_RedirectionRequest *
-GNUNET_VPN_redirect_to_peer (struct GNUNET_VPN_Handle *rh,                 
-                             int af,
+GNUNET_VPN_redirect_to_peer (struct GNUNET_VPN_Handle *vh,
+                             int result_af,
                              uint8_t protocol,
                              const struct GNUNET_PeerIdentity *peer,
                              const GNUNET_HashCode *serv,
@@ -183,7 +454,20 @@ GNUNET_VPN_redirect_to_peer (struct GNUNET_VPN_Handle *rh,
                              GNUNET_VPN_AllocationCallback cb,
                              void *cb_cls)
 {
-  return NULL; // FIXME
+  struct GNUNET_VPN_RedirectionRequest *rr;
+
+  rr = GNUNET_malloc (sizeof (struct GNUNET_VPN_RedirectionRequest));
+  rr->vh = vh;
+  rr->cb = cb;
+  rr->cb_cls = cb_cls;
+  rr->peer = *peer;
+  rr->serv = *serv;
+  rr->expiration_time = expiration_time;
+  rr->result_af = result_af;
+  rr->nac = nac;
+  rr->protocol = protocol;
+  queue_request (rr);
+  return rr;
 }
 
                 
@@ -213,7 +497,7 @@ GNUNET_VPN_redirect_to_peer (struct GNUNET_VPN_Handle *rh,
  *         anyway)
  */
 struct GNUNET_VPN_RedirectionRequest *
-GNUNET_VPN_redirect_to_ip (struct GNUNET_VPN_Handle *rh,                   
+GNUNET_VPN_redirect_to_ip (struct GNUNET_VPN_Handle *vh,
                            int result_af,
                            int addr_af,
                            const void *addr,
@@ -222,7 +506,33 @@ GNUNET_VPN_redirect_to_ip (struct GNUNET_VPN_Handle *rh,
                            GNUNET_VPN_AllocationCallback cb,
                            void *cb_cls)
 {
-  return NULL; // FIXME
+  struct GNUNET_VPN_RedirectionRequest *rr;
+  size_t alen;
+
+  switch (addr_af)
+  {
+  case AF_INET:
+    alen = sizeof (struct in_addr);
+    break;
+  case AF_INET6:
+    alen = sizeof (struct in6_addr);
+    break;
+  default:
+    GNUNET_break (0);
+    return NULL;
+  }
+  rr = GNUNET_malloc (sizeof (struct GNUNET_VPN_RedirectionRequest) + alen);
+  rr->vh = vh;
+  rr->addr = &rr[1];
+  rr->cb = cb;
+  rr->cb_cls = cb_cls;
+  rr->expiration_time = expiration_time;
+  rr->result_af = result_af;
+  rr->addr_af = addr_af;
+  rr->nac = nac;
+  memcpy (&rr[1], addr, alen);
+  queue_request (rr);
+  return rr;
 }
 
 
@@ -240,6 +550,11 @@ GNUNET_VPN_connect (const struct GNUNET_CONFIGURATION_Handle *cfg)
   vh = GNUNET_malloc (sizeof (struct GNUNET_VPN_Handle));
   vh->cfg = cfg;
   vh->client = GNUNET_CLIENT_connect ("vpn", cfg);
+  if (NULL == vh->client)
+  {
+    GNUNET_free (vh);
+    return NULL;
+  }
   return vh;
 }
 
@@ -253,7 +568,21 @@ void
 GNUNET_VPN_disconnect (struct GNUNET_VPN_Handle *vh)
 {
   GNUNET_assert (NULL == vh->rr_head);
-  GNUNET_CLIENT_disconnect (vh->client, GNUNET_NO);
+  if (NULL != vh->th)
+  {
+    GNUNET_CLIENT_notify_transmit_ready_cancel (vh->th);
+    vh->th = NULL;
+  }
+  if (NULL != vh->client)
+  {
+    GNUNET_CLIENT_disconnect (vh->client, GNUNET_NO);
+    vh->client = NULL;
+  }
+  if (GNUNET_SCHEDULER_NO_TASK != vh->rt)
+  {
+    GNUNET_SCHEDULER_cancel (vh->rt);
+    vh->rt = GNUNET_SCHEDULER_NO_TASK;
+  }
   GNUNET_free (vh);
 }