Smallers steps to keep plugin running
[oweals/gnunet.git] / src / arm / arm_api.c
index c5bb15fd3c01d4f5eea6f640885a2360a4a35306..66747a624acde3d7190926e1044ad00df255301d 100644 (file)
@@ -1,10 +1,10 @@
 /*
      This file is part of GNUnet.
-     (C) 2009 Christian Grothoff (and other contributing authors)
+     (C) 2009, 2010 Christian Grothoff (and other contributing authors)
 
      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 2, or (at your
+     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
 #include "arm.h"
 
 
-struct ArmContext
+/**
+ * Handle for interacting with ARM.
+ */
+struct GNUNET_ARM_Handle
 {
-  GNUNET_ARM_Callback callback;
-  void *cls;
-  char *service_name;
+
+  /**
+   * Our connection to the ARM service.
+   */
   struct GNUNET_CLIENT_Connection *client;
+
+  /**
+   * The configuration that we are using.
+   */
   struct GNUNET_CONFIGURATION_Handle *cfg;
+
+  /**
+   * Scheduler to use.
+   */
+  struct GNUNET_SCHEDULER_Handle *sched;
+
+};
+
+
+/**
+ * Context for handling the shutdown of a service.
+ */
+struct ShutdownContext
+{
+  /**
+   * Scheduler to be used to call continuation
+   */
+  struct GNUNET_SCHEDULER_Handle *sched;
+  /**
+   * Connection to the service that is being shutdown.
+   */
+  struct GNUNET_CLIENT_Connection *sock;
+
+  /**
+   * Time allowed for shutdown to happen.
+   */
   struct GNUNET_TIME_Absolute timeout;
+
+  /**
+   * Task set up to cancel the shutdown request on timeout.
+   */
+  GNUNET_SCHEDULER_TaskIdentifier cancel_task;
+
+  /**
+   * Task to call once shutdown complete
+   */
+  GNUNET_CLIENT_ShutdownTask cont;
+
+  /**
+   * Closure for shutdown continuation
+   */
+  void *cont_cls;
+
+  /**
+   * We received a confirmation that the service will shut down.
+   */
+  int confirmed;
+
+};
+
+/**
+ * Handler receiving response to service shutdown requests.
+ * First call with NULL: service misbehaving, or something.
+ * First call with GNUNET_MESSAGE_TYPE_ARM_SHUTDOWN_ACK:
+ *   - service will shutdown
+ * Second call with NULL:
+ *   - service has now really shut down.
+ *
+ * @param cls closure
+ * @param msg NULL, indicating socket closure.
+ */
+static void
+service_shutdown_handler (void *cls, const struct GNUNET_MessageHeader *msg)
+{
+  struct ShutdownContext *shutdown_ctx = cls;
+
+  if ((msg == NULL) && (shutdown_ctx->confirmed != GNUNET_YES))
+    {
+      /* Means the other side closed the connection and never confirmed a shutdown */
+      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                 "Service handle shutdown before ACK!\n");
+      if (shutdown_ctx->cont != NULL)
+        shutdown_ctx->cont(shutdown_ctx->cont_cls, GNUNET_SYSERR);
+      GNUNET_SCHEDULER_cancel(shutdown_ctx->sched, shutdown_ctx->cancel_task);
+      GNUNET_CLIENT_disconnect (shutdown_ctx->sock, GNUNET_NO);
+      GNUNET_free(shutdown_ctx);
+    }
+  else if ((msg == NULL) && (shutdown_ctx->confirmed == GNUNET_YES))
+    {
+#if DEBUG_ARM
+      GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
+                "Service shutdown complete.\n");
+#endif
+      if (shutdown_ctx->cont != NULL)
+        shutdown_ctx->cont(shutdown_ctx->cont_cls, GNUNET_NO);
+
+      GNUNET_SCHEDULER_cancel(shutdown_ctx->sched, shutdown_ctx->cancel_task);
+      GNUNET_CLIENT_disconnect (shutdown_ctx->sock, GNUNET_NO);
+      GNUNET_free(shutdown_ctx);
+    }
+  else
+    {
+      GNUNET_assert(ntohs(msg->size) == sizeof(struct GNUNET_MessageHeader));
+      switch (ntohs(msg->type))
+       {
+       case GNUNET_MESSAGE_TYPE_ARM_SHUTDOWN_ACK:
+#if DEBUG_ARM
+         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
+                    "Received confirmation for service shutdown.\n");
+#endif
+         shutdown_ctx->confirmed = GNUNET_YES;
+         GNUNET_CLIENT_receive (shutdown_ctx->sock,
+                                &service_shutdown_handler,
+                                shutdown_ctx,
+                                GNUNET_TIME_UNIT_FOREVER_REL);
+         break;
+       default: /* Fall through */
+#if DEBUG_ARM
+         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
+                    "Service shutdown refused!\n");
+#endif
+         if (shutdown_ctx->cont != NULL)
+           shutdown_ctx->cont(shutdown_ctx->cont_cls, GNUNET_YES);
+
+         GNUNET_SCHEDULER_cancel(shutdown_ctx->sched, shutdown_ctx->cancel_task);
+         GNUNET_CLIENT_disconnect (shutdown_ctx->sock, GNUNET_NO);
+         GNUNET_free(shutdown_ctx);
+         break;
+       }
+    }
+}
+
+/**
+ * Shutting down took too long, cancel receive and return error.
+ *
+ * @param cls closure
+ * @param tc context information (why was this task triggered now)
+ */
+void service_shutdown_cancel (void *cls,
+                              const struct GNUNET_SCHEDULER_TaskContext * tc)
+{
+  struct ShutdownContext *shutdown_ctx = cls;
+  GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "service_shutdown_cancel called!\n");
+  shutdown_ctx->cont(shutdown_ctx->cont_cls, GNUNET_SYSERR);
+  GNUNET_CLIENT_disconnect (shutdown_ctx->sock, GNUNET_NO);
+  GNUNET_free(shutdown_ctx);
+}
+
+
+/**
+ * If possible, write a shutdown message to the target
+ * buffer and destroy the client connection.
+ *
+ * @param cls the "struct GNUNET_CLIENT_Connection" to destroy
+ * @param size number of bytes available in buf
+ * @param buf NULL on error, otherwise target buffer
+ * @return number of bytes written to buf
+ */
+static size_t
+write_shutdown (void *cls, size_t size, void *buf)
+{
+  struct GNUNET_MessageHeader *msg;
+  struct ShutdownContext *shutdown_ctx = cls;
+
+  if (size < sizeof (struct GNUNET_MessageHeader))
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                  _("Failed to transmit shutdown request to client.\n"));
+      shutdown_ctx->cont(shutdown_ctx->cont_cls, GNUNET_SYSERR);
+      GNUNET_CLIENT_disconnect (shutdown_ctx->sock, GNUNET_NO);
+      GNUNET_free(shutdown_ctx);
+      return 0;                 /* client disconnected */
+    }
+
+  GNUNET_CLIENT_receive (shutdown_ctx->sock,
+                        &service_shutdown_handler, shutdown_ctx,
+                        GNUNET_TIME_UNIT_FOREVER_REL);
+  shutdown_ctx->cancel_task = GNUNET_SCHEDULER_add_delayed (shutdown_ctx->sched,
+                                                           GNUNET_TIME_absolute_get_remaining(shutdown_ctx->timeout),
+                                                           &service_shutdown_cancel,
+                                                           shutdown_ctx);
+  msg = (struct GNUNET_MessageHeader *) buf;
+  msg->type = htons (GNUNET_MESSAGE_TYPE_ARM_SHUTDOWN);
+  msg->size = htons (sizeof (struct GNUNET_MessageHeader));
+  return sizeof (struct GNUNET_MessageHeader);
+}
+
+
+/**
+ * Request that the service should shutdown.
+ * Afterwards, the connection will automatically be
+ * disconnected.  Hence the "sock" should not
+ * be used by the caller after this call
+ * (calling this function frees "sock" after a while).
+ *
+ * @param sched the scheduler to use for calling shutdown continuation
+ * @param sock the socket connected to the service
+ * @param timeout how long to wait before giving up on transmission
+ * @param cont continuation to call once the service is really down
+ * @param cont_cls closure for continuation
+ *
+ */
+static void
+arm_service_shutdown (struct GNUNET_SCHEDULER_Handle *sched,
+                     struct GNUNET_CLIENT_Connection *sock,
+                     struct GNUNET_TIME_Relative timeout,
+                     GNUNET_CLIENT_ShutdownTask cont,
+                     void *cont_cls)
+{
+  struct ShutdownContext *shutdown_ctx;
+  shutdown_ctx = GNUNET_malloc(sizeof(struct ShutdownContext));
+  shutdown_ctx->sched = sched;
+  shutdown_ctx->cont = cont;
+  shutdown_ctx->cont_cls = cont_cls;
+  shutdown_ctx->sock = sock;
+  shutdown_ctx->timeout = GNUNET_TIME_relative_to_absolute(timeout);
+  GNUNET_CLIENT_notify_transmit_ready (sock,
+                                      sizeof (struct
+                                              GNUNET_MessageHeader),
+                                      timeout,
+                                      GNUNET_YES,
+                                      &write_shutdown, shutdown_ctx);
+}
+
+
+/**
+ * Setup a context for communicating with ARM.  Note that this
+ * can be done even if the ARM service is not yet running.
+ *
+ * @param cfg configuration to use (needed to contact ARM;
+ *        the ARM service may internally use a different
+ *        configuration to determine how to start the service).
+ * @param sched scheduler to use
+ * @param service service that *this* process is implementing/providing, can be NULL
+ * @return context to use for further ARM operations, NULL on error
+ */
+struct GNUNET_ARM_Handle *
+GNUNET_ARM_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
+                   struct GNUNET_SCHEDULER_Handle *sched,
+                   const char *service)
+{
+  struct GNUNET_ARM_Handle *ret;
+
+  ret = GNUNET_malloc (sizeof (struct GNUNET_ARM_Handle));
+  ret->cfg = GNUNET_CONFIGURATION_dup (cfg);
+  ret->sched = sched;
+  return ret;
+}
+
+
+/**
+ * Disconnect from the ARM service.
+ *
+ * @param h the handle that was being used
+ */
+void
+GNUNET_ARM_disconnect (struct GNUNET_ARM_Handle *h)
+{
+  if (h->client != NULL)
+    GNUNET_CLIENT_disconnect (h->client, GNUNET_NO);
+  GNUNET_CONFIGURATION_destroy (h->cfg);
+  GNUNET_free (h);
+}
+
+struct ARM_ShutdownContext
+{
+  /**
+   * Callback to call once shutdown complete.
+   */
+  GNUNET_ARM_Callback cb;
+
+  /**
+   * Closure for callback.
+   */
+  void *cb_cls;
+};
+
+
+
+/**
+ * Internal state for a request with ARM.
+ */
+struct RequestContext
+{
+
+  /**
+   * Pointer to our handle with ARM.
+   */
+  struct GNUNET_ARM_Handle *h;
+
+  /**
+   * Function to call with a status code for the requested operation.
+   */
+  GNUNET_ARM_Callback callback;
+
+  /**
+   * Closure for "callback".
+   */
+  void *cls;
+
+  /**
+   * Timeout for the operation.
+   */
+  struct GNUNET_TIME_Absolute timeout;
+
+  /**
+   * Type of the request expressed as a message type (start or stop).
+   */
   uint16_t type;
+
 };
 
+#include "do_start_process.c"
+
 
+/**
+ * A client specifically requested starting of ARM itself.
+ * This function is called with information about whether
+ * or not ARM is running; if it is, report success.  If
+ * it is not, start the ARM process.
+ *
+ * @param cls the context for the request that we will report on (struct RequestContext*)
+ * @param tc why were we called (reason says if ARM is running)
+ */
 static void
-arm_service_report (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
+arm_service_report (void *cls,
+                   const struct GNUNET_SCHEDULER_TaskContext *tc)
 {
-  struct ArmContext *pos = cls;
+  struct RequestContext *pos = cls;
   pid_t pid;
   char *binary;
   char *config;
+  char *loprefix;
+  char *lopostfix;
 
   if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_PREREQ_DONE))
     {
+#if DEBUG_ARM
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                 "Looks like `%s' is already running.\n",
+                 "gnunet-service-arm");
+#endif
+      /* arm is running! */
       if (pos->callback != NULL)
         pos->callback (pos->cls, GNUNET_YES);
       GNUNET_free (pos);
       return;
     }
-  binary = NULL;
-  config = NULL;
-  /* start service */
-  if ((GNUNET_OK !=
-       GNUNET_CONFIGURATION_get_value_filename (pos->cfg,
-                                                "arm",
-                                                "BINARY",
-                                                &binary)) ||
-      (GNUNET_OK !=
-       GNUNET_CONFIGURATION_get_value_filename (pos->cfg,
-                                                "arm", "CONFIG", &config)))
+#if DEBUG_ARM
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+             "Looks like `%s' is not running, will start it.\n",
+             "gnunet-service-arm");
+#endif
+  /* FIXME: should we check that HOSTNAME for 'arm' is localhost? */
+
+ if (GNUNET_OK !=
+      GNUNET_CONFIGURATION_get_value_string (pos->h->cfg,
+                                            "arm", "PREFIX", &loprefix))
+    loprefix = GNUNET_strdup ("");
+  if (GNUNET_OK !=
+      GNUNET_CONFIGURATION_get_value_string (pos->h->cfg,
+                                            "arm", "OPTIONS", &lopostfix))
+    lopostfix = GNUNET_strdup ("");
+  if (GNUNET_OK !=
+      GNUNET_CONFIGURATION_get_value_string (pos->h->cfg,
+                                            "arm",
+                                            "BINARY",
+                                            &binary))
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                  _("Configuration failes to specify option `%s' in section `%s'!\n"),
+                 "BINARY",
+                 "arm");
+      if (pos->callback != NULL)
+        pos->callback (pos->cls, GNUNET_SYSERR);
+      GNUNET_free (pos);
+      GNUNET_free (loprefix);
+      GNUNET_free (lopostfix);
+      return;
+    }
+  if (GNUNET_OK !=
+      GNUNET_CONFIGURATION_get_value_filename (pos->h->cfg,
+                                              "arm", "CONFIG", &config))
     {
       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
-                  _("Configuration file or binary for ARM not known!\n"));
+                  _("Configuration fails to specify option `%s' in section `%s'!\n"),
+                 "CONFIG",
+                 "arm");
       if (pos->callback != NULL)
         pos->callback (pos->cls, GNUNET_SYSERR);
-      GNUNET_free_non_null (binary);
+      GNUNET_free (binary);
       GNUNET_free (pos);
+      GNUNET_free (loprefix);
+      GNUNET_free (lopostfix);
       return;
     }
-  pid = GNUNET_OS_start_process (binary, binary, "-d", "-c", config,
+  if ((GNUNET_YES == GNUNET_CONFIGURATION_have_value (pos->h->cfg,
+                                                      "TESTING",
+                                                      "WEAKRANDOM")) &&
+      (GNUNET_YES == GNUNET_CONFIGURATION_get_value_yesno (pos->h->cfg,
+                                                           "TESTING",
+                                                           "WEAKRANDOM")) &&
+      (GNUNET_NO == GNUNET_CONFIGURATION_have_value (pos->h->cfg,
+                                                     "TESTING",
+                                                     "HOSTFILE")) /* Means we are ONLY running locally */
+                                                           )
+    {
+      /* we're clearly running a test, don't daemonize */
+      pid = do_start_process (NULL,
+                             loprefix,
+                             binary,
+                             "-c", config,
 #if DEBUG_ARM
-                                 "-L", "DEBUG",
+                             "-L", "DEBUG",
 #endif
-                                 NULL);
+                             /* no daemonization! */
+                             lopostfix,
+                             NULL);
+    }
+  else
+    {
+      pid = do_start_process (NULL,
+                             loprefix,
+                             binary,
+                             "-c", config,
+#if DEBUG_ARM
+                             "-L", "DEBUG",
+#endif
+                             "-d",
+                             lopostfix,
+                             NULL);
+    }
   GNUNET_free (binary);
   GNUNET_free (config);
+  GNUNET_free (loprefix);
+  GNUNET_free (lopostfix);
   if (pid == -1)
     {
       if (pos->callback != NULL)
@@ -94,24 +481,39 @@ arm_service_report (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
       GNUNET_free (pos);
       return;
     }
-  /* FIXME: consider checking again to see if it worked!? */
   if (pos->callback != NULL)
     pos->callback (pos->cls, GNUNET_YES);
   GNUNET_free (pos);
 }
 
 
+/**
+ * Process a response from ARM to a request for a change in service
+ * status.
+ *
+ * @param cls the request context
+ * @param msg the response
+ */
 static void
 handle_response (void *cls, const struct GNUNET_MessageHeader *msg)
 {
-  struct ArmContext *sc = cls;
+  struct RequestContext *sc = cls;
   int ret;
 
   if (msg == NULL)
     {
       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
-                  _("Error receiving response from ARM service\n"));
-      GNUNET_CLIENT_disconnect (sc->client);
+                 _("Error receiving response to `%s' request from ARM for service `%s'\n"),
+                 (sc->type == GNUNET_MESSAGE_TYPE_ARM_START)
+                 ? "START"
+                 : "STOP",
+                 (const char*) &sc[1]);
+      GNUNET_CLIENT_disconnect (sc->h->client, GNUNET_NO);
+      sc->h->client = GNUNET_CLIENT_connect (sc->h->sched,
+                                            "arm",
+                                            sc->h->cfg);
+      GNUNET_assert (NULL != sc->h->client);
+      GNUNET_CLIENT_ignore_shutdown (sc->h->client, GNUNET_YES);
       if (sc->callback != NULL)
         sc->callback (sc->cls, GNUNET_SYSERR);
       GNUNET_free (sc);
@@ -119,7 +521,9 @@ handle_response (void *cls, const struct GNUNET_MessageHeader *msg)
     }
 #if DEBUG_ARM
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              _("Received response from ARM service\n"));
+              "Received response from ARM for service `%s': %u\n",
+             (const char*) &sc[1],
+             ntohs(msg->type));
 #endif
   switch (ntohs (msg->type))
     {
@@ -129,209 +533,202 @@ handle_response (void *cls, const struct GNUNET_MessageHeader *msg)
     case GNUNET_MESSAGE_TYPE_ARM_IS_DOWN:
       ret = GNUNET_NO;
       break;
+    case GNUNET_MESSAGE_TYPE_ARM_IS_UNKNOWN:
+      ret = GNUNET_SYSERR;
+      break;
     default:
       GNUNET_break (0);
       ret = GNUNET_SYSERR;
     }
-  GNUNET_CLIENT_disconnect (sc->client);
   if (sc->callback != NULL)
     sc->callback (sc->cls, ret);
   GNUNET_free (sc);
 }
 
 
-static size_t
-send_service_msg (void *cls, size_t size, void *buf)
-{
-  struct ArmContext *sctx = cls;
-  struct GNUNET_MessageHeader *msg;
-  size_t slen;
-
-  if (buf == NULL)
-    {
-      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
-                  _("Error while trying to transmit to ARM service\n"));
-      GNUNET_CLIENT_disconnect (sctx->client);
-      if (sctx->callback != NULL)
-        sctx->callback (sctx->cls, GNUNET_SYSERR);
-      GNUNET_free (sctx->service_name);
-      GNUNET_free (sctx);
-      return 0;
-    }
-#if DEBUG_ARM
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              _("Transmitting service request to ARM.\n"));
-#endif
-  slen = strlen (sctx->service_name) + 1;
-  GNUNET_assert (size >= slen);
-  msg = buf;
-  msg->size = htons (sizeof (struct GNUNET_MessageHeader) + slen);
-  msg->type = htons (sctx->type);
-  memcpy (&msg[1], sctx->service_name, slen);
-  GNUNET_free (sctx->service_name);
-  sctx->service_name = NULL;
-  GNUNET_CLIENT_receive (sctx->client,
-                         &handle_response,
-                         sctx,
-                         GNUNET_TIME_absolute_get_remaining (sctx->timeout));
-  return slen + sizeof (struct GNUNET_MessageHeader);
-}
-
-
 /**
  * Start or stop a service.
  *
+ * @param h handle to ARM
  * @param service_name name of the service
- * @param cfg configuration to use (needed to contact ARM;
- *        the ARM service may internally use a different
- *        configuration to determine how to start the service).
- * @param sched scheduler to use
  * @param timeout how long to wait before failing for good
  * @param cb callback to invoke when service is ready
  * @param cb_cls closure for callback
+ * @param type type of the request
  */
 static void
-change_service (const char *service_name,
-                struct GNUNET_CONFIGURATION_Handle *cfg,
-                struct GNUNET_SCHEDULER_Handle *sched,
+change_service (struct GNUNET_ARM_Handle *h,
+               const char *service_name,
                 struct GNUNET_TIME_Relative timeout,
                 GNUNET_ARM_Callback cb, void *cb_cls, uint16_t type)
 {
-  struct GNUNET_CLIENT_Connection *client;
-  struct ArmContext *sctx;
+  struct RequestContext *sctx;
   size_t slen;
+  struct GNUNET_MessageHeader *msg;
 
   slen = strlen (service_name) + 1;
-  if (slen + sizeof (struct GNUNET_MessageHeader) >
-      GNUNET_SERVER_MAX_MESSAGE_SIZE)
+  if (slen + sizeof (struct GNUNET_MessageHeader) >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
     {
       GNUNET_break (0);
       if (cb != NULL)
         cb (cb_cls, GNUNET_NO);
       return;
     }
-  client = GNUNET_CLIENT_connect (sched, "arm", cfg);
-  if (client == NULL)
-    {
-      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
-                  _("Failed to connect to ARM service\n"));
-      if (cb != NULL)
-        cb (cb_cls, GNUNET_SYSERR);
-      return;
-    }
 #if DEBUG_ARM
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              _("ARM requests starting of service `%s'.\n"), service_name);
+              (type == GNUNET_MESSAGE_TYPE_ARM_START)
+             ? _("Requesting start of service `%s'.\n")
+             : _("Requesting termination of service `%s'.\n"),
+             service_name);
 #endif
-  sctx = GNUNET_malloc (sizeof (struct ArmContext));
+  sctx = GNUNET_malloc (sizeof (struct RequestContext) + slen);
+  sctx->h = h;
   sctx->callback = cb;
   sctx->cls = cb_cls;
-  sctx->client = client;
-  sctx->service_name = GNUNET_strdup (service_name);
   sctx->timeout = GNUNET_TIME_relative_to_absolute (timeout);
   sctx->type = type;
-  if (NULL ==
-      GNUNET_CLIENT_notify_transmit_ready (client,
-                                           slen +
-                                           sizeof (struct
-                                                   GNUNET_MessageHeader),
-                                           timeout, &send_service_msg, sctx))
+  memcpy (&sctx[1], service_name, slen);
+  msg = GNUNET_malloc (sizeof (struct GNUNET_MessageHeader) + slen);
+  msg->size = htons (sizeof (struct GNUNET_MessageHeader) + slen);
+  msg->type = htons (sctx->type);
+  memcpy (&msg[1], service_name, slen);
+  if (GNUNET_OK !=
+      GNUNET_CLIENT_transmit_and_get_response (sctx->h->client,
+                                              msg,
+                                              GNUNET_TIME_absolute_get_remaining (sctx->timeout),
+                                              GNUNET_YES,
+                                              &handle_response,
+                                              sctx))
     {
       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
-                  _("Failed to transmit request to ARM service\n"));
-      GNUNET_free (sctx->service_name);
-      GNUNET_free (sctx);
+                 (type == GNUNET_MESSAGE_TYPE_ARM_START)
+                 ? _("Error while trying to transmit request to start `%s' to ARM\n")
+                 : _("Error while trying to transmit request to stop `%s' to ARM\n"),
+                 (const char*) &service_name);
       if (cb != NULL)
-        cb (cb_cls, GNUNET_SYSERR);
-      GNUNET_CLIENT_disconnect (client);
+       cb (cb_cls, GNUNET_SYSERR);
+      GNUNET_free (sctx);
+      GNUNET_free (msg);
       return;
     }
+  GNUNET_free (msg);
 }
 
 
 /**
  * Start a service.
  *
+ * @param h handle to ARM
  * @param service_name name of the service
- * @param cfg configuration to use (needed to contact ARM;
- *        the ARM service may internally use a different
- *        configuration to determine how to start the service).
- * @param sched scheduler to use
  * @param timeout how long to wait before failing for good
  * @param cb callback to invoke when service is ready
  * @param cb_cls closure for callback
  */
 void
-GNUNET_ARM_start_service (const char *service_name,
-                          struct GNUNET_CONFIGURATION_Handle *cfg,
-                          struct GNUNET_SCHEDULER_Handle *sched,
+GNUNET_ARM_start_service (struct GNUNET_ARM_Handle *h,
+                         const char *service_name,
                           struct GNUNET_TIME_Relative timeout,
                           GNUNET_ARM_Callback cb, void *cb_cls)
 {
-  struct ArmContext *sctx;
-
-  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
-              _("Starting service `%s'\n"), service_name);
-  if (0 == strcmp ("arm", service_name))
+  struct RequestContext *sctx;
+  struct GNUNET_CLIENT_Connection *client;
+  size_t slen;
+#if DEBUG_ARM
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              _("Asked to start service `%s' within %llu ms\n"), service_name,
+             (unsigned long long) timeout.value);
+#endif
+  if (0 == strcasecmp ("arm", service_name))
     {
-      sctx = GNUNET_malloc (sizeof (struct ArmContext));
+      slen = strlen ("arm") + 1;
+      sctx = GNUNET_malloc (sizeof (struct RequestContext) + slen);
+      sctx->h = h;
       sctx->callback = cb;
       sctx->cls = cb_cls;
-      sctx->cfg = cfg;
-      GNUNET_CLIENT_service_test (sched,
+      sctx->timeout = GNUNET_TIME_relative_to_absolute (timeout);
+      memcpy (&sctx[1], service_name, slen);
+      GNUNET_CLIENT_service_test (h->sched,
                                   "arm",
-                                  cfg, timeout, &arm_service_report, sctx);
+                                  h->cfg, timeout, &arm_service_report, sctx);
       return;
     }
-  change_service (service_name,
-                  cfg,
-                  sched, timeout, cb, cb_cls, GNUNET_MESSAGE_TYPE_ARM_START);
+  if (h->client == NULL)
+    {
+      client = GNUNET_CLIENT_connect (h->sched, "arm", h->cfg);
+      if (client == NULL)
+       {
+         cb (cb_cls, GNUNET_SYSERR);
+         return;
+       }
+      GNUNET_CLIENT_ignore_shutdown (client, GNUNET_YES);
+      h->client = client;
+    }
+  change_service (h, service_name, timeout, cb, cb_cls, GNUNET_MESSAGE_TYPE_ARM_START);
 }
 
+/**
+ * Callback from the arm stop service call, indicates that the arm service
+ * is well and truly dead, won't die, or an error occurred.
+ *
+ * @param cls closure for the callback
+ * @param reason reason for callback, GNUNET_NO if arm is shutdown
+ *        GNUNET_YES if arm remains running, and GNUNET_SYSERR on error
+ */
+void arm_shutdown_callback (void *cls,
+                            int reason)
+{
+  struct ARM_ShutdownContext *arm_shutdown_ctx = cls;
+
+  if (arm_shutdown_ctx->cb != NULL)
+    arm_shutdown_ctx->cb (arm_shutdown_ctx->cb_cls, reason);
 
+  GNUNET_free(arm_shutdown_ctx);
+}
 
 
 /**
  * Stop a service.
  *
+ * @param h handle to ARM
  * @param service_name name of the service
- * @param cfg configuration to use (needed to contact ARM;
- *        the ARM service may internally use a different
- *        configuration to determine how to start the service).
- * @param sched scheduler to use
  * @param timeout how long to wait before failing for good
  * @param cb callback to invoke when service is ready
  * @param cb_cls closure for callback
  */
 void
-GNUNET_ARM_stop_service (const char *service_name,
-                         struct GNUNET_CONFIGURATION_Handle *cfg,
-                         struct GNUNET_SCHEDULER_Handle *sched,
+GNUNET_ARM_stop_service (struct GNUNET_ARM_Handle *h,
+                         const char *service_name,
                          struct GNUNET_TIME_Relative timeout,
                          GNUNET_ARM_Callback cb, void *cb_cls)
 {
+  struct ARM_ShutdownContext *arm_shutdown_ctx;
   struct GNUNET_CLIENT_Connection *client;
 
   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
-              _("Stopping service `%s'\n"), service_name);
-  if (0 == strcmp ("arm", service_name))
+              _("Stopping service `%s' within %llu ms\n"), service_name,
+             (unsigned long long) timeout.value);
+  if (h->client == NULL)
     {
-      client = GNUNET_CLIENT_connect (sched, "arm", cfg);
+      client = GNUNET_CLIENT_connect (h->sched, "arm", h->cfg);
       if (client == NULL)
-        {
-          if (cb != NULL)
-            cb (cb_cls, GNUNET_SYSERR);
-          return;
-        }
-      GNUNET_CLIENT_service_shutdown (client);
-      GNUNET_CLIENT_disconnect (client);
-      if (cb != NULL)
-        cb (cb_cls, GNUNET_NO);
+       {
+         cb (cb_cls, GNUNET_SYSERR);
+         return;
+       }
+      GNUNET_CLIENT_ignore_shutdown (client, GNUNET_YES);
+      h->client = client;
+    }
+  if (0 == strcasecmp ("arm", service_name))
+    {
+      arm_shutdown_ctx = GNUNET_malloc(sizeof(struct ARM_ShutdownContext));
+      arm_shutdown_ctx->cb = cb;
+      arm_shutdown_ctx->cb_cls = cb_cls;
+      arm_service_shutdown (h->sched, h->client, timeout, &arm_shutdown_callback, arm_shutdown_ctx);
+      h->client = NULL;
       return;
     }
-  change_service (service_name,
-                  cfg,
-                  sched, timeout, cb, cb_cls, GNUNET_MESSAGE_TYPE_ARM_STOP);
+  change_service (h, service_name, timeout, cb, cb_cls, GNUNET_MESSAGE_TYPE_ARM_STOP);
 }
 
+
 /* end of arm_api.c */