1 files changed, 433 insertions, 0 deletions

diff --git a/src/zklaim/zklaim_api.c b/src/zklaim/zklaim_api.c
new file mode 100644
index 000000000..f54ede342
--- /dev/null
+++ b/src/zklaim/zklaim_api.c
@@ -0,0 +1,433 @@
+/*
+     This file is part of GNUnet.
+     Copyright (C) 2013, 2016 GNUnet e.V.
+
+     GNUnet is free software: you can redistribute it and/or modify it
+     under the terms of the GNU Affero General Public License as published
+     by the Free Software Foundation, either version 3 of the License,
+     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
+     Affero General Public License for more details.
+
+     You should have received a copy of the GNU Affero General Public License
+     along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/**
+ * @file zklaim/zklaim_api.c
+ * @brief api to interact with the zklaim service
+ * @author Martin Schanzenbach
+ */
+#include "platform.h"
+#include "gnunet_util_lib.h"
+#include "gnunet_constants.h"
+#include "gnunet_protocols.h"
+#include "gnunet_zklaim_service.h"
+#include "zklaim/zklaim.h"
+#include "zklaim_api.h"
+
+#define LOG(kind,...) GNUNET_log_from (kind, "zklaim-api",__VA_ARGS__)
+
+/**
+ * Handle for an ego.
+ */
+struct GNUNET_ZKLAIM_Context
+{
+  /**
+   * ZKlaim context.
+   */
+  struct zklaim_ctx *zk_ctx;
+
+  /**
+   * Current name associated with this context.
+   */
+  char *name;
+
+  /**
+   * Attributes associated with context
+   */
+  char *attrs;
+
+  /**
+   * Client context associated with this ego.
+   */
+  void *ctx;
+
+};
+
+
+/**
+ * Handle for an operation with the service.
+ */
+struct GNUNET_ZKLAIM_Operation
+{
+
+  /**
+   * Main handle.
+   */
+  struct GNUNET_ZKLAIM_Handle *h;
+
+  /**
+   * We keep operations in a DLL.
+   */
+  struct GNUNET_ZKLAIM_Operation *next;
+
+  /**
+   * We keep operations in a DLL.
+   */
+  struct GNUNET_ZKLAIM_Operation *prev;
+
+  /**
+   * Message to send to the zklaim service.
+   * Allocated at the end of this struct.
+   */
+  const struct GNUNET_MessageHeader *msg;
+
+  /**
+   * Continuation to invoke with the result of the transmission; @e cb
+   * will be NULL in this case.
+   */
+  GNUNET_ZKLAIM_ContinuationWithStatus cont;
+
+  /**
+   * Closure for @e cont or @e cb.
+   */
+  void *cls;
+
+};
+
+
+/**
+ * Handle for the service.
+ */
+struct GNUNET_ZKLAIM_Handle
+{
+  /**
+   * Configuration to use.
+   */
+  const struct GNUNET_CONFIGURATION_Handle *cfg;
+
+  /**
+   * Connection to service.
+   */
+  struct GNUNET_MQ_Handle *mq;
+
+  /**
+   * Hash map from the hash of the public key to the
+   * respective `GNUNET_ZKLAIM_Ego` handle.
+   */
+  struct GNUNET_CONTAINER_MultiHashMap *egos;
+
+  /**
+   * Closure for @e cb.
+   */
+  void *cb_cls;
+
+  /**
+   * Head of active operations.
+   */
+  struct GNUNET_ZKLAIM_Operation *op_head;
+
+  /**
+   * Tail of active operations.
+   */
+  struct GNUNET_ZKLAIM_Operation *op_tail;
+
+  /**
+   * Task doing exponential back-off trying to reconnect.
+   */
+  struct GNUNET_SCHEDULER_Task *reconnect_task;
+
+  /**
+   * Time for next connect retry.
+   */
+  struct GNUNET_TIME_Relative reconnect_delay;
+
+};
+
+
+/**
+ * Try again to connect to the zklaim service.
+ *
+ * @param cls handle to the zklaim service.
+ */
+static void
+reconnect (void *cls);
+
+/**
+ * Reschedule a connect attempt to the service.
+ *
+ * @param h transport service to reconnect
+ */
+static void
+reschedule_connect (struct GNUNET_ZKLAIM_Handle *h)
+{
+  struct GNUNET_ZKLAIM_Operation *op;
+
+  GNUNET_assert (NULL == h->reconnect_task);
+
+  if (NULL != h->mq)
+  {
+    GNUNET_MQ_destroy (h->mq);
+    h->mq = NULL;
+  }
+  while (NULL != (op = h->op_head))
+  {
+    GNUNET_CONTAINER_DLL_remove (h->op_head,
+                                 h->op_tail,
+                                 op);
+    if (NULL != op->cont)
+      op->cont (op->cls,
+                GNUNET_SYSERR,
+                "Error in communication with the zklaim service");
+    GNUNET_free (op);
+  }
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Scheduling task to reconnect to zklaim service in %s.\n",
+       GNUNET_STRINGS_relative_time_to_string (h->reconnect_delay,
+                                               GNUNET_YES));
+  h->reconnect_task =
+      GNUNET_SCHEDULER_add_delayed (h->reconnect_delay,
+                                    &reconnect,
+                                    h);
+  h->reconnect_delay = GNUNET_TIME_STD_BACKOFF (h->reconnect_delay);
+}
+
+
+/**
+ * Generic error handler, called with the appropriate error code and
+ * the same closure specified at the creation of the message queue.
+ * Not every message queue implementation supports an error handler.
+ *
+ * @param cls closure with the `struct GNUNET_ZKLAIM_Handle *`
+ * @param error error code
+ */
+static void
+mq_error_handler (void *cls,
+                  enum GNUNET_MQ_Error error)
+{
+  struct GNUNET_ZKLAIM_Handle *h = cls;
+
+  reschedule_connect (h);
+}
+
+
+/**
+ * We received a result code from the service.  Check the message
+ * is well-formed.
+ *
+ * @param cls closure
+ * @param rcm result message received
+ * @return #GNUNET_OK if the message is well-formed
+ */
+static int
+check_zklaim_result_code (void *cls,
+                            const struct ResultCodeMessage *rcm)
+{
+  uint16_t size = ntohs (rcm->header.size) - sizeof (*rcm);
+  const char *str = (const char *) &rcm[1];
+
+  if (0 == size)
+    return GNUNET_OK;
+  if ('\0' != str[size - 1])
+  {
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  }
+  return GNUNET_OK;
+}
+
+
+/**
+ * We received a result code from the service.
+ *
+ * @param cls closure
+ * @param rcm result message received
+ */
+static void
+handle_zklaim_result_code (void *cls,
+                             const struct ResultCodeMessage *rcm)
+{
+  struct GNUNET_ZKLAIM_Handle *h = cls;
+  struct GNUNET_ZKLAIM_Operation *op;
+  uint16_t size = ntohs (rcm->header.size) - sizeof (*rcm);
+  const char *str = (0 == size) ? NULL : (const char *) &rcm[1];
+
+  op = h->op_head;
+  if (NULL == op)
+  {
+    GNUNET_break (0);
+    reschedule_connect (h);
+    return;
+  }
+  GNUNET_CONTAINER_DLL_remove (h->op_head,
+                               h->op_tail,
+                               op);
+  if (NULL != op->cont)
+    op->cont (op->cls,
+              GNUNET_OK,
+              str);
+  GNUNET_free (op);
+}
+
+
+/**
+ * Try again to connect to the zklaim service.
+ *
+ * @param cls handle to the zklaim service.
+ */
+static void
+reconnect (void *cls)
+{
+  struct GNUNET_ZKLAIM_Handle *h = cls;
+  struct GNUNET_MQ_MessageHandler handlers[] = {
+    GNUNET_MQ_hd_var_size (zklaim_result_code,
+                           GNUNET_MESSAGE_TYPE_ZKLAIM_RESULT_CODE,
+                           struct ResultCodeMessage,
+                           h),
+    GNUNET_MQ_handler_end ()
+  };
+
+  h->reconnect_task = NULL;
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Connecting to zklaim service.\n");
+  GNUNET_assert (NULL == h->mq);
+  h->mq = GNUNET_CLIENT_connect (h->cfg,
+                                 "zklaim",
+                                 handlers,
+                                 &mq_error_handler,
+                                 h);
+  if (NULL == h->mq)
+    return;
+}
+
+
+/**
+ * Connect to the zklaim service.
+ *
+ * @param cfg the configuration to use
+ * @param cb function to call on all zklaim events, can be NULL
+ * @param cb_cls closure for @a cb
+ * @return handle to use
+ */
+struct GNUNET_ZKLAIM_Handle *
+GNUNET_ZKLAIM_connect (const struct GNUNET_CONFIGURATION_Handle *cfg)
+{
+  struct GNUNET_ZKLAIM_Handle *h;
+
+  h = GNUNET_new (struct GNUNET_ZKLAIM_Handle);
+  h->cfg = cfg;
+  reconnect (h);
+  if (NULL == h->mq)
+  {
+    GNUNET_free (h);
+    return NULL;
+  }
+  return h;
+}
+
+
+/**
+ * Create a new zklaim with the given name.
+ *
+ * @param h zklaim service to use
+ * @param name desired name
+ * @param cont function to call with the result (will only be called once)
+ * @param cont_cls closure for @a cont
+ * @return handle to abort the operation
+ */
+struct GNUNET_ZKLAIM_Operation *
+GNUNET_ZKLAIM_context_create (struct GNUNET_ZKLAIM_Handle *h,
+                              const struct GNUNET_CRYPTO_EcdsaPrivateKey *pk,
+                              const char *name,
+                              const char *attr_list,
+                              GNUNET_ZKLAIM_ContinuationWithStatus cont,
+                              void *cont_cls)
+{
+  struct GNUNET_ZKLAIM_Operation *op;
+  struct GNUNET_MQ_Envelope *env;
+  struct CreateRequestMessage *crm;
+  size_t slen;
+
+  if (NULL == h->mq)
+    return NULL;
+  slen = strlen (name) + 1;
+  if (slen >= GNUNET_MAX_MESSAGE_SIZE - sizeof (struct CreateRequestMessage))
+  {
+    GNUNET_break (0);
+    return NULL;
+  }
+  op = GNUNET_new (struct GNUNET_ZKLAIM_Operation);
+  op->h = h;
+  op->cont = cont;
+  op->cls = cont_cls;
+  GNUNET_CONTAINER_DLL_insert_tail (h->op_head,
+                                    h->op_tail,
+                                    op);
+  env = GNUNET_MQ_msg_extra (crm,
+                             slen,
+                             GNUNET_MESSAGE_TYPE_ZKLAIM_CREATE);
+  crm->name_len = htons (slen);
+  crm->reserved = htons (0);
+  crm->private_key = *pk;
+  GNUNET_memcpy (&crm[1],
+                 name,
+                 slen);
+  GNUNET_MQ_send (h->mq,
+                  env);
+  //TODO add attrs
+  return op;
+}
+
+
+/**
+ * Cancel an zklaim operation. Note that the operation MAY still
+ * be executed; this merely cancels the continuation; if the request
+ * was already transmitted, the service may still choose to complete
+ * the operation.
+ *
+ * @param op operation to cancel
+ */
+void
+GNUNET_ZKLAIM_cancel (struct GNUNET_ZKLAIM_Operation *op)
+{
+  op->cont = NULL;
+}
+
+
+/**
+ * Disconnect from zklaim service
+ *
+ * @param h handle to destroy
+ */
+void
+GNUNET_ZKLAIM_disconnect (struct GNUNET_ZKLAIM_Handle *h)
+{
+  struct GNUNET_ZKLAIM_Operation *op;
+
+  GNUNET_assert (NULL != h);
+  if (h->reconnect_task != NULL)
+  {
+    GNUNET_SCHEDULER_cancel (h->reconnect_task);
+    h->reconnect_task = NULL;
+  }
+  while (NULL != (op = h->op_head))
+  {
+    GNUNET_break (NULL == op->cont);
+    GNUNET_CONTAINER_DLL_remove (h->op_head,
+                                 h->op_tail,
+                                 op);
+    GNUNET_free (op);
+  }
+  if (NULL != h->mq)
+  {
+    GNUNET_MQ_destroy (h->mq);
+    h->mq = NULL;
+  }
+  GNUNET_free (h);
+}
+
+/* end of zklaim_api.c */