-vpn api skeleton

1 files changed, 253 insertions, 0 deletions

diff --git a/src/vpn/vpn_api.c b/src/vpn/vpn_api.c
new file mode 100644
index 000000000..5c351a190
--- /dev/null
+++ b/src/vpn/vpn_api.c
@@ -0,0 +1,253 @@
+/*
+     This file is part of GNUnet.
+     (C) 2012 Christian Grothoff
+
+     GNUnet is free software; you can redistribute it and/or modify
+     it under the terms of the GNU General Public License as published
+     by the Free Software Foundation; either version 3, 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
+     General Public License for more details.
+
+     You should have received a copy of the GNU General Public License
+     along with GNUnet; see the file COPYING.  If not, write to the
+     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+     Boston, MA 02111-1307, USA.
+*/
+
+/**
+ * @file vpn/vpn_api.c
+ * @brief library to access the VPN service and tell it how to redirect traffic
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "gnunet_vpn_service.h"
+#include "vpn.h"
+
+
+/**
+ * Opaque VPN handle
+ */
+struct GNUNET_VPN_Handle
+{
+  /**
+   * Configuration we use.
+   */
+  const struct GNUNET_CONFIGURATION_Handle *cfg;
+
+  /**
+   * Connection to VPN service.
+   */
+  struct GNUNET_CLIENT_Connection *client;
+
+  /**
+   * Head of list of active redirection requests.
+   */
+  struct GNUNET_VPN_RedirectionRequest *rr_head;
+
+  /**
+   * Tail of list of active redirection requests.
+   */
+  struct GNUNET_VPN_RedirectionRequest *rr_tail;
+};
+
+
+/**
+ * Opaque redirection request handle.
+ */
+struct GNUNET_VPN_RedirectionRequest
+{
+  /**
+   * Element in DLL.
+   */
+  struct GNUNET_VPN_RedirectionRequest *next;
+
+  /**
+   * Element in DLL.
+   */
+  struct GNUNET_VPN_RedirectionRequest *prev;
+
+  /**
+   * Pointer to the VPN struct.
+   */
+  struct GNUNET_VPN_Handle *vh;
+
+  /**
+   * Target IP address for the redirection, or NULL for
+   * redirection to service.  Allocated after this struct.
+   */
+  const void *addr;
+
+  /**
+   * Function to call with the designated IP address.
+   */
+  GNUNET_VPN_AllocationCallback cb;
+  
+  /**
+   * Closure for 'cb'.
+   */
+  void *cb_cls;
+
+  /**
+   * For service redirection, identity of the peer offering the service.
+   */
+  struct GNUNET_PeerIdentity peer;
+
+  /**
+   * For service redirection, service descriptor.
+   */
+  GNUNET_HashCode serv;              
+
+  /**
+   * At what time should the created service mapping expire?
+   */
+  struct GNUNET_TIME_Absolute expiration_time;
+
+  /**
+   * AF_INET or AF_INET6.
+   */
+  int af;
+  
+  /**
+   * GNUNET_YES if we are to call the callback only after successful
+   * mesh tunnel creation.
+   */
+  int nac;
+  
+  /**
+   * For service redirection, IPPROT_UDP or IPPROTO_TCP.
+   */
+  uint8_t protocol;
+
+};
+
+
+/**
+ * Cancel redirection request with the service.
+ *
+ * @param rr request to cancel
+ */
+void
+GNUNET_VPN_cancel_request (struct GNUNET_VPN_RedirectionRequest *rr)
+{
+  struct GNUNET_VPN_Handle *vh;
+
+  vh = rr->vh;
+  GNUNET_CONTAINER_DLL_remove (vh->rr_head,
+                               vh->rr_tail,
+                               rr);
+  GNUNET_free (rr);
+}
+
+
+/**
+ * Tell the VPN that a forwarding to a particular peer offering a
+ * particular service is requested.  The VPN is to reserve a
+ * particular IP for the redirection and return it.  The VPN will
+ * begin the redirection as soon as possible and maintain it as long
+ * as it is actively used and keeping it is feasible.  Given resource
+ * limitations, the longest inactive mappings will be destroyed.
+ *
+ * @param vh VPN handle
+ * @param af address family, AF_INET or AF_INET6
+ * @param protocol protocol, IPPROTO_UDP or IPPROTO_TCP
+ * @param peer target peer for the redirection
+ * @param serv service descriptor to give to the peer
+ * @param nac GNUNET_YES to notify via callback only after completion of
+ *            the MESH-level connection,
+ *            GNUNET_NO to notify as soon as the IP has been reserved
+ * @param expiration_time at what time should the redirection expire?
+ *        (this should not impact connections that are active at that time)
+ * @param cb function to call with the IP
+ * @param cb_cls closure for cb
+ * @return handle to cancel the request (means the callback won't be
+ *         invoked anymore; the mapping may or may not be established
+ *         anyway)
+ */
+struct GNUNET_VPN_RedirectionRequest *
+GNUNET_VPN_redirect_to_peer (struct GNUNET_VPN_Handle *rh,                 
+                             int af,
+                             uint8_t protocol,
+                             const struct GNUNET_PeerIdentity *peer,
+                             const GNUNET_HashCode *serv,
+                             int nac,
+                             struct GNUNET_TIME_Absolute expiration_time,
+                             GNUNET_VPN_AllocationCallback cb,
+                             void *cb_cls)
+{
+  return NULL; // FIXME
+}
+
+                
+/**
+ * Tell the VPN that forwarding to the Internet via some exit node is
+ * requested.  Note that both UDP and TCP traffic will be forwarded,
+ * but possibly to different exit nodes.  The VPN is to reserve a
+ * particular IP for the redirection and return it.  The VPN will
+ * begin the redirection as soon as possible and maintain it as long
+ * as it is actively used and keeping it is feasible.  Given resource
+ * limitations, the longest inactive mappings will be destroyed.
+ *
+ * @param vh VPN handle
+ * @param af address family, AF_INET or AF_INET6
+ * @param addr destination IP address on the Internet; destination
+ *             port is to be taken from the VPN packet itself
+ * @param nac GNUNET_YES to notify via callback only after completion of
+ *            the MESH-level connection,
+ *            GNUNET_NO to notify as soon as the IP has been reserved
+ * @param expiration_time at what time should the redirection expire?
+ *        (this should not impact connections that are active at that time)
+ * @param cb function to call with the IP
+ * @param cb_cls closure for cb
+ * @return handle to cancel the request (means the callback won't be
+ *         invoked anymore; the mapping may or may not be established
+ *         anyway)
+ */
+struct GNUNET_VPN_RedirectionRequest *
+GNUNET_VPN_redirect_to_ip (struct GNUNET_VPN_Handle *rh,                   
+                           int af,
+                           const void *addr,
+                           int nac,
+                           struct GNUNET_TIME_Absolute expiration_time,
+                           GNUNET_VPN_AllocationCallback cb,
+                           void *cb_cls)
+{
+  return NULL; // FIXME
+}
+
+
+/**
+ * Connect to the VPN service
+ *
+ * @param cfg configuration to use
+ * @return VPN handle 
+ */
+struct GNUNET_VPN_Handle *
+GNUNET_VPN_connect (const struct GNUNET_CONFIGURATION_Handle *cfg)
+{
+  struct GNUNET_VPN_Handle *vh;
+
+  vh = GNUNET_malloc (sizeof (struct GNUNET_VPN_Handle));
+  vh->cfg = cfg;
+  vh->client = GNUNET_CLIENT_connect ("vpn", cfg);
+  return vh;
+}
+
+
+/**
+ * Disconnect from the VPN service.
+ *
+ * @param vh VPN handle
+ */
+void
+GNUNET_VPN_disconnect (struct GNUNET_VPN_Handle *vh)
+{
+  GNUNET_assert (NULL == vh->rr_head);
+  GNUNET_CLIENT_disconnect (vh->client, GNUNET_NO);
+  GNUNET_free (vh);
+}
+
+/* end of vpn_api.c */