Adding upstream version 1.0.18.upstream/1.0.18upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1171 insertions, 0 deletions

diff --git a/libevent/evrpc.c b/libevent/evrpc.c
new file mode 100644
index 0000000..4a60ca5
--- /dev/null
+++ b/libevent/evrpc.c
@@ -0,0 +1,1171 @@
+/*
+ * Copyright (c) 2000-2007 Niels Provos <provos@citi.umich.edu>
+ * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include "event2/event-config.h"
+#include "evconfig-private.h"
+
+#ifdef _WIN32
+#define WIN32_LEAN_AND_MEAN
+#include <winsock2.h>
+#include <windows.h>
+#undef WIN32_LEAN_AND_MEAN
+#endif
+
+#include <sys/types.h>
+#ifndef _WIN32
+#include <sys/socket.h>
+#endif
+#ifdef EVENT__HAVE_SYS_TIME_H
+#include <sys/time.h>
+#endif
+#include <sys/queue.h>
+#include <stdio.h>
+#include <stdlib.h>
+#ifndef _WIN32
+#include <unistd.h>
+#endif
+#include <errno.h>
+#include <signal.h>
+#include <string.h>
+
+#include <sys/queue.h>
+
+#include "event2/event.h"
+#include "event2/event_struct.h"
+#include "event2/rpc.h"
+#include "event2/rpc_struct.h"
+#include "evrpc-internal.h"
+#include "event2/http.h"
+#include "event2/buffer.h"
+#include "event2/tag.h"
+#include "event2/http_struct.h"
+#include "event2/http_compat.h"
+#include "event2/util.h"
+#include "util-internal.h"
+#include "log-internal.h"
+#include "mm-internal.h"
+
+struct evrpc_base *
+evrpc_init(struct evhttp *http_server)
+{
+	struct evrpc_base* base = mm_calloc(1, sizeof(struct evrpc_base));
+	if (base == NULL)
+		return (NULL);
+
+	/* we rely on the tagging sub system */
+	evtag_init();
+
+	TAILQ_INIT(&base->registered_rpcs);
+	TAILQ_INIT(&base->input_hooks);
+	TAILQ_INIT(&base->output_hooks);
+
+	TAILQ_INIT(&base->paused_requests);
+
+	base->http_server = http_server;
+
+	return (base);
+}
+
+void
+evrpc_free(struct evrpc_base *base)
+{
+	struct evrpc *rpc;
+	struct evrpc_hook *hook;
+	struct evrpc_hook_ctx *pause;
+	int r;
+
+	while ((rpc = TAILQ_FIRST(&base->registered_rpcs)) != NULL) {
+		r = evrpc_unregister_rpc(base, rpc->uri);
+		EVUTIL_ASSERT(r == 0);
+	}
+	while ((pause = TAILQ_FIRST(&base->paused_requests)) != NULL) {
+		TAILQ_REMOVE(&base->paused_requests, pause, next);
+		mm_free(pause);
+	}
+	while ((hook = TAILQ_FIRST(&base->input_hooks)) != NULL) {
+		r = evrpc_remove_hook(base, EVRPC_INPUT, hook);
+		EVUTIL_ASSERT(r);
+	}
+	while ((hook = TAILQ_FIRST(&base->output_hooks)) != NULL) {
+		r = evrpc_remove_hook(base, EVRPC_OUTPUT, hook);
+		EVUTIL_ASSERT(r);
+	}
+	mm_free(base);
+}
+
+void *
+evrpc_add_hook(void *vbase,
+    enum EVRPC_HOOK_TYPE hook_type,
+    int (*cb)(void *, struct evhttp_request *, struct evbuffer *, void *),
+    void *cb_arg)
+{
+	struct evrpc_hooks_ *base = vbase;
+	struct evrpc_hook_list *head = NULL;
+	struct evrpc_hook *hook = NULL;
+	switch (hook_type) {
+	case EVRPC_INPUT:
+		head = &base->in_hooks;
+		break;
+	case EVRPC_OUTPUT:
+		head = &base->out_hooks;
+		break;
+	default:
+		EVUTIL_ASSERT(hook_type == EVRPC_INPUT || hook_type == EVRPC_OUTPUT);
+	}
+
+	hook = mm_calloc(1, sizeof(struct evrpc_hook));
+	EVUTIL_ASSERT(hook != NULL);
+
+	hook->process = cb;
+	hook->process_arg = cb_arg;
+	TAILQ_INSERT_TAIL(head, hook, next);
+
+	return (hook);
+}
+
+static int
+evrpc_remove_hook_internal(struct evrpc_hook_list *head, void *handle)
+{
+	struct evrpc_hook *hook = NULL;
+	TAILQ_FOREACH(hook, head, next) {
+		if (hook == handle) {
+			TAILQ_REMOVE(head, hook, next);
+			mm_free(hook);
+			return (1);
+		}
+	}
+
+	return (0);
+}
+
+/*
+ * remove the hook specified by the handle
+ */
+
+int
+evrpc_remove_hook(void *vbase, enum EVRPC_HOOK_TYPE hook_type, void *handle)
+{
+	struct evrpc_hooks_ *base = vbase;
+	struct evrpc_hook_list *head = NULL;
+	switch (hook_type) {
+	case EVRPC_INPUT:
+		head = &base->in_hooks;
+		break;
+	case EVRPC_OUTPUT:
+		head = &base->out_hooks;
+		break;
+	default:
+		EVUTIL_ASSERT(hook_type == EVRPC_INPUT || hook_type == EVRPC_OUTPUT);
+	}
+
+	return (evrpc_remove_hook_internal(head, handle));
+}
+
+static int
+evrpc_process_hooks(struct evrpc_hook_list *head, void *ctx,
+    struct evhttp_request *req, struct evbuffer *evbuf)
+{
+	struct evrpc_hook *hook;
+	TAILQ_FOREACH(hook, head, next) {
+		int res = hook->process(ctx, req, evbuf, hook->process_arg);
+		if (res != EVRPC_CONTINUE)
+			return (res);
+	}
+
+	return (EVRPC_CONTINUE);
+}
+
+static void evrpc_pool_schedule(struct evrpc_pool *pool);
+static void evrpc_request_cb(struct evhttp_request *, void *);
+
+/*
+ * Registers a new RPC with the HTTP server.   The evrpc object is expected
+ * to have been filled in via the EVRPC_REGISTER_OBJECT macro which in turn
+ * calls this function.
+ */
+
+static char *
+evrpc_construct_uri(const char *uri)
+{
+	char *constructed_uri;
+	size_t constructed_uri_len;
+
+	constructed_uri_len = strlen(EVRPC_URI_PREFIX) + strlen(uri) + 1;
+	if ((constructed_uri = mm_malloc(constructed_uri_len)) == NULL)
+		event_err(1, "%s: failed to register rpc at %s",
+		    __func__, uri);
+	memcpy(constructed_uri, EVRPC_URI_PREFIX, strlen(EVRPC_URI_PREFIX));
+	memcpy(constructed_uri + strlen(EVRPC_URI_PREFIX), uri, strlen(uri));
+	constructed_uri[constructed_uri_len - 1] = '\0';
+
+	return (constructed_uri);
+}
+
+int
+evrpc_register_rpc(struct evrpc_base *base, struct evrpc *rpc,
+    void (*cb)(struct evrpc_req_generic *, void *), void *cb_arg)
+{
+	char *constructed_uri = evrpc_construct_uri(rpc->uri);
+
+	rpc->base = base;
+	rpc->cb = cb;
+	rpc->cb_arg = cb_arg;
+
+	TAILQ_INSERT_TAIL(&base->registered_rpcs, rpc, next);
+
+	evhttp_set_cb(base->http_server,
+	    constructed_uri,
+	    evrpc_request_cb,
+	    rpc);
+
+	mm_free(constructed_uri);
+
+	return (0);
+}
+
+int
+evrpc_unregister_rpc(struct evrpc_base *base, const char *name)
+{
+	char *registered_uri = NULL;
+	struct evrpc *rpc;
+	int r;
+
+	/* find the right rpc; linear search might be slow */
+	TAILQ_FOREACH(rpc, &base->registered_rpcs, next) {
+		if (strcmp(rpc->uri, name) == 0)
+			break;
+	}
+	if (rpc == NULL) {
+		/* We did not find an RPC with this name */
+		return (-1);
+	}
+	TAILQ_REMOVE(&base->registered_rpcs, rpc, next);
+
+	registered_uri = evrpc_construct_uri(name);
+
+	/* remove the http server callback */
+	r = evhttp_del_cb(base->http_server, registered_uri);
+	EVUTIL_ASSERT(r == 0);
+
+	mm_free(registered_uri);
+
+	mm_free((char *)rpc->uri);
+	mm_free(rpc);
+	return (0);
+}
+
+static int evrpc_pause_request(void *vbase, void *ctx,
+    void (*cb)(void *, enum EVRPC_HOOK_RESULT));
+static void evrpc_request_cb_closure(void *, enum EVRPC_HOOK_RESULT);
+
+static void
+evrpc_request_cb(struct evhttp_request *req, void *arg)
+{
+	struct evrpc *rpc = arg;
+	struct evrpc_req_generic *rpc_state = NULL;
+
+	/* let's verify the outside parameters */
+	if (req->type != EVHTTP_REQ_POST ||
+	    evbuffer_get_length(req->input_buffer) <= 0)
+		goto error;
+
+	rpc_state = mm_calloc(1, sizeof(struct evrpc_req_generic));
+	if (rpc_state == NULL)
+		goto error;
+	rpc_state->rpc = rpc;
+	rpc_state->http_req = req;
+	rpc_state->rpc_data = NULL;
+
+	if (TAILQ_FIRST(&rpc->base->input_hooks) != NULL) {
+		int hook_res;
+
+		evrpc_hook_associate_meta_(&rpc_state->hook_meta, req->evcon);
+
+		/*
+		 * allow hooks to modify the outgoing request
+		 */
+		hook_res = evrpc_process_hooks(&rpc->base->input_hooks,
+		    rpc_state, req, req->input_buffer);
+		switch (hook_res) {
+		case EVRPC_TERMINATE:
+			goto error;
+		case EVRPC_PAUSE:
+			evrpc_pause_request(rpc->base, rpc_state,
+			    evrpc_request_cb_closure);
+			return;
+		case EVRPC_CONTINUE:
+			break;
+		default:
+			EVUTIL_ASSERT(hook_res == EVRPC_TERMINATE ||
+			    hook_res == EVRPC_CONTINUE ||
+			    hook_res == EVRPC_PAUSE);
+		}
+	}
+
+	evrpc_request_cb_closure(rpc_state, EVRPC_CONTINUE);
+	return;
+
+error:
+	if (rpc_state)
+		evrpc_reqstate_free_(rpc_state);
+	evhttp_send_error(req, HTTP_SERVUNAVAIL, NULL);
+	return;
+}
+
+static void
+evrpc_request_cb_closure(void *arg, enum EVRPC_HOOK_RESULT hook_res)
+{
+	struct evrpc_req_generic *rpc_state = arg;
+	struct evrpc *rpc;
+	struct evhttp_request *req;
+
+	EVUTIL_ASSERT(rpc_state);
+	rpc = rpc_state->rpc;
+	req = rpc_state->http_req;
+
+	if (hook_res == EVRPC_TERMINATE)
+		goto error;
+
+	/* let's check that we can parse the request */
+	rpc_state->request = rpc->request_new(rpc->request_new_arg);
+	if (rpc_state->request == NULL)
+		goto error;
+
+	if (rpc->request_unmarshal(
+		    rpc_state->request, req->input_buffer) == -1) {
+		/* we failed to parse the request; that's a bummer */
+		goto error;
+	}
+
+	/* at this point, we have a well formed request, prepare the reply */
+
+	rpc_state->reply = rpc->reply_new(rpc->reply_new_arg);
+	if (rpc_state->reply == NULL)
+		goto error;
+
+	/* give the rpc to the user; they can deal with it */
+	rpc->cb(rpc_state, rpc->cb_arg);
+
+	return;
+
+error:
+	evrpc_reqstate_free_(rpc_state);
+	evhttp_send_error(req, HTTP_SERVUNAVAIL, NULL);
+	return;
+}
+
+
+void
+evrpc_reqstate_free_(struct evrpc_req_generic* rpc_state)
+{
+	struct evrpc *rpc;
+	EVUTIL_ASSERT(rpc_state != NULL);
+	rpc = rpc_state->rpc;
+
+	/* clean up all memory */
+	if (rpc_state->hook_meta != NULL)
+		evrpc_hook_context_free_(rpc_state->hook_meta);
+	if (rpc_state->request != NULL)
+		rpc->request_free(rpc_state->request);
+	if (rpc_state->reply != NULL)
+		rpc->reply_free(rpc_state->reply);
+	if (rpc_state->rpc_data != NULL)
+		evbuffer_free(rpc_state->rpc_data);
+	mm_free(rpc_state);
+}
+
+static void
+evrpc_request_done_closure(void *, enum EVRPC_HOOK_RESULT);
+
+void
+evrpc_request_done(struct evrpc_req_generic *rpc_state)
+{
+	struct evhttp_request *req;
+	struct evrpc *rpc;
+
+	EVUTIL_ASSERT(rpc_state);
+
+	req = rpc_state->http_req;
+	rpc = rpc_state->rpc;
+
+	if (rpc->reply_complete(rpc_state->reply) == -1) {
+		/* the reply was not completely filled in.  error out */
+		goto error;
+	}
+
+	if ((rpc_state->rpc_data = evbuffer_new()) == NULL) {
+		/* out of memory */
+		goto error;
+	}
+
+	/* serialize the reply */
+	rpc->reply_marshal(rpc_state->rpc_data, rpc_state->reply);
+
+	if (TAILQ_FIRST(&rpc->base->output_hooks) != NULL) {
+		int hook_res;
+
+		evrpc_hook_associate_meta_(&rpc_state->hook_meta, req->evcon);
+
+		/* do hook based tweaks to the request */
+		hook_res = evrpc_process_hooks(&rpc->base->output_hooks,
+		    rpc_state, req, rpc_state->rpc_data);
+		switch (hook_res) {
+		case EVRPC_TERMINATE:
+			goto error;
+		case EVRPC_PAUSE:
+			if (evrpc_pause_request(rpc->base, rpc_state,
+				evrpc_request_done_closure) == -1)
+				goto error;
+			return;
+		case EVRPC_CONTINUE:
+			break;
+		default:
+			EVUTIL_ASSERT(hook_res == EVRPC_TERMINATE ||
+			    hook_res == EVRPC_CONTINUE ||
+			    hook_res == EVRPC_PAUSE);
+		}
+	}
+
+	evrpc_request_done_closure(rpc_state, EVRPC_CONTINUE);
+	return;
+
+error:
+	evrpc_reqstate_free_(rpc_state);
+	evhttp_send_error(req, HTTP_SERVUNAVAIL, NULL);
+	return;
+}
+
+void *
+evrpc_get_request(struct evrpc_req_generic *req)
+{
+	return req->request;
+}
+
+void *
+evrpc_get_reply(struct evrpc_req_generic *req)
+{
+	return req->reply;
+}
+
+static void
+evrpc_request_done_closure(void *arg, enum EVRPC_HOOK_RESULT hook_res)
+{
+	struct evrpc_req_generic *rpc_state = arg;
+	struct evhttp_request *req;
+	EVUTIL_ASSERT(rpc_state);
+	req = rpc_state->http_req;
+
+	if (hook_res == EVRPC_TERMINATE)
+		goto error;
+
+	/* on success, we are going to transmit marshaled binary data */
+	if (evhttp_find_header(req->output_headers, "Content-Type") == NULL) {
+		evhttp_add_header(req->output_headers,
+		    "Content-Type", "application/octet-stream");
+	}
+	evhttp_send_reply(req, HTTP_OK, "OK", rpc_state->rpc_data);
+
+	evrpc_reqstate_free_(rpc_state);
+
+	return;
+
+error:
+	evrpc_reqstate_free_(rpc_state);
+	evhttp_send_error(req, HTTP_SERVUNAVAIL, NULL);
+	return;
+}
+
+
+/* Client implementation of RPC site */
+
+static int evrpc_schedule_request(struct evhttp_connection *connection,
+    struct evrpc_request_wrapper *ctx);
+
+struct evrpc_pool *
+evrpc_pool_new(struct event_base *base)
+{
+	struct evrpc_pool *pool = mm_calloc(1, sizeof(struct evrpc_pool));
+	if (pool == NULL)
+		return (NULL);
+
+	TAILQ_INIT(&pool->connections);
+	TAILQ_INIT(&pool->requests);
+
+	TAILQ_INIT(&pool->paused_requests);
+
+	TAILQ_INIT(&pool->input_hooks);
+	TAILQ_INIT(&pool->output_hooks);
+
+	pool->base = base;
+	pool->timeout = -1;
+
+	return (pool);
+}
+
+static void
+evrpc_request_wrapper_free(struct evrpc_request_wrapper *request)
+{
+	if (request->hook_meta != NULL)
+		evrpc_hook_context_free_(request->hook_meta);
+	mm_free(request->name);
+	mm_free(request);
+}
+
+void
+evrpc_pool_free(struct evrpc_pool *pool)
+{
+	struct evhttp_connection *connection;
+	struct evrpc_request_wrapper *request;
+	struct evrpc_hook_ctx *pause;
+	struct evrpc_hook *hook;
+	int r;
+
+	while ((request = TAILQ_FIRST(&pool->requests)) != NULL) {
+		TAILQ_REMOVE(&pool->requests, request, next);
+		evrpc_request_wrapper_free(request);
+	}
+
+	while ((pause = TAILQ_FIRST(&pool->paused_requests)) != NULL) {
+		TAILQ_REMOVE(&pool->paused_requests, pause, next);
+		mm_free(pause);
+	}
+
+	while ((connection = TAILQ_FIRST(&pool->connections)) != NULL) {
+		TAILQ_REMOVE(&pool->connections, connection, next);
+		evhttp_connection_free(connection);
+	}
+
+	while ((hook = TAILQ_FIRST(&pool->input_hooks)) != NULL) {
+		r = evrpc_remove_hook(pool, EVRPC_INPUT, hook);
+		EVUTIL_ASSERT(r);
+	}
+
+	while ((hook = TAILQ_FIRST(&pool->output_hooks)) != NULL) {
+		r = evrpc_remove_hook(pool, EVRPC_OUTPUT, hook);
+		EVUTIL_ASSERT(r);
+	}
+
+	mm_free(pool);
+}
+
+/*
+ * Add a connection to the RPC pool.   A request scheduled on the pool
+ * may use any available connection.
+ */
+
+void
+evrpc_pool_add_connection(struct evrpc_pool *pool,
+    struct evhttp_connection *connection)
+{
+	EVUTIL_ASSERT(connection->http_server == NULL);
+	TAILQ_INSERT_TAIL(&pool->connections, connection, next);
+
+	/*
+	 * associate an event base with this connection
+	 */
+	if (pool->base != NULL)
+		evhttp_connection_set_base(connection, pool->base);
+
+	/*
+	 * unless a timeout was specifically set for a connection,
+	 * the connection inherits the timeout from the pool.
+	 */
+	if (!evutil_timerisset(&connection->timeout))
+		evhttp_connection_set_timeout(connection, pool->timeout);
+
+	/*
+	 * if we have any requests pending, schedule them with the new
+	 * connections.
+	 */
+
+	if (TAILQ_FIRST(&pool->requests) != NULL) {
+		struct evrpc_request_wrapper *request =
+		    TAILQ_FIRST(&pool->requests);
+		TAILQ_REMOVE(&pool->requests, request, next);
+		evrpc_schedule_request(connection, request);
+	}
+}
+
+void
+evrpc_pool_remove_connection(struct evrpc_pool *pool,
+    struct evhttp_connection *connection)
+{
+	TAILQ_REMOVE(&pool->connections, connection, next);
+}
+
+void
+evrpc_pool_set_timeout(struct evrpc_pool *pool, int timeout_in_secs)
+{
+	struct evhttp_connection *evcon;
+	TAILQ_FOREACH(evcon, &pool->connections, next) {
+		evhttp_connection_set_timeout(evcon, timeout_in_secs);
+	}
+	pool->timeout = timeout_in_secs;
+}
+
+
+static void evrpc_reply_done(struct evhttp_request *, void *);
+static void evrpc_request_timeout(evutil_socket_t, short, void *);
+
+/*
+ * Finds a connection object associated with the pool that is currently
+ * idle and can be used to make a request.
+ */
+static struct evhttp_connection *
+evrpc_pool_find_connection(struct evrpc_pool *pool)
+{
+	struct evhttp_connection *connection;
+	TAILQ_FOREACH(connection, &pool->connections, next) {
+		if (TAILQ_FIRST(&connection->requests) == NULL)
+			return (connection);
+	}
+
+	return (NULL);
+}
+
+/*
+ * Prototypes responsible for evrpc scheduling and hooking
+ */
+
+static void evrpc_schedule_request_closure(void *ctx, enum EVRPC_HOOK_RESULT);
+
+/*
+ * We assume that the ctx is no longer queued on the pool.
+ */
+static int
+evrpc_schedule_request(struct evhttp_connection *connection,
+    struct evrpc_request_wrapper *ctx)
+{
+	struct evhttp_request *req = NULL;
+	struct evrpc_pool *pool = ctx->pool;
+	struct evrpc_status status;
+
+	if ((req = evhttp_request_new(evrpc_reply_done, ctx)) == NULL)
+		goto error;
+
+	/* serialize the request data into the output buffer */
+	ctx->request_marshal(req->output_buffer, ctx->request);
+
+	/* we need to know the connection that we might have to abort */
+	ctx->evcon = connection;
+
+	/* if we get paused we also need to know the request */
+	ctx->req = req;
+
+	if (TAILQ_FIRST(&pool->output_hooks) != NULL) {
+		int hook_res;
+
+		evrpc_hook_associate_meta_(&ctx->hook_meta, connection);
+
+		/* apply hooks to the outgoing request */
+		hook_res = evrpc_process_hooks(&pool->output_hooks,
+		    ctx, req, req->output_buffer);
+
+		switch (hook_res) {
+		case EVRPC_TERMINATE:
+			goto error;
+		case EVRPC_PAUSE:
+			/* we need to be explicitly resumed */
+			if (evrpc_pause_request(pool, ctx,
+				evrpc_schedule_request_closure) == -1)
+				goto error;
+			return (0);
+		case EVRPC_CONTINUE:
+			/* we can just continue */
+			break;
+		default:
+			EVUTIL_ASSERT(hook_res == EVRPC_TERMINATE ||
+			    hook_res == EVRPC_CONTINUE ||
+			    hook_res == EVRPC_PAUSE);
+		}
+	}
+
+	evrpc_schedule_request_closure(ctx, EVRPC_CONTINUE);
+	return (0);
+
+error:
+	memset(&status, 0, sizeof(status));
+	status.error = EVRPC_STATUS_ERR_UNSTARTED;
+	(*ctx->cb)(&status, ctx->request, ctx->reply, ctx->cb_arg);
+	evrpc_request_wrapper_free(ctx);
+	return (-1);
+}
+
+static void
+evrpc_schedule_request_closure(void *arg, enum EVRPC_HOOK_RESULT hook_res)
+{
+	struct evrpc_request_wrapper *ctx = arg;
+	struct evhttp_connection *connection = ctx->evcon;
+	struct evhttp_request *req = ctx->req;
+	struct evrpc_pool *pool = ctx->pool;
+	struct evrpc_status status;
+	char *uri = NULL;
+	int res = 0;
+
+	if (hook_res == EVRPC_TERMINATE)
+		goto error;
+
+	uri = evrpc_construct_uri(ctx->name);
+	if (uri == NULL)
+		goto error;
+
+	if (pool->timeout > 0) {
+		/*
+		 * a timeout after which the whole rpc is going to be aborted.
+		 */
+		struct timeval tv;
+		evutil_timerclear(&tv);
+		tv.tv_sec = pool->timeout;
+		evtimer_add(&ctx->ev_timeout, &tv);
+	}
+
+	/* start the request over the connection */
+	res = evhttp_make_request(connection, req, EVHTTP_REQ_POST, uri);
+	mm_free(uri);
+
+	if (res == -1)
+		goto error;
+
+	return;
+
+error:
+	memset(&status, 0, sizeof(status));
+	status.error = EVRPC_STATUS_ERR_UNSTARTED;
+	(*ctx->cb)(&status, ctx->request, ctx->reply, ctx->cb_arg);
+	evrpc_request_wrapper_free(ctx);
+}
+
+/* we just queue the paused request on the pool under the req object */
+static int
+evrpc_pause_request(void *vbase, void *ctx,
+    void (*cb)(void *, enum EVRPC_HOOK_RESULT))
+{
+	struct evrpc_hooks_ *base = vbase;
+	struct evrpc_hook_ctx *pause = mm_malloc(sizeof(*pause));
+	if (pause == NULL)
+		return (-1);
+
+	pause->ctx = ctx;
+	pause->cb = cb;
+
+	TAILQ_INSERT_TAIL(&base->pause_requests, pause, next);
+	return (0);
+}
+
+int
+evrpc_resume_request(void *vbase, void *ctx, enum EVRPC_HOOK_RESULT res)
+{
+	struct evrpc_hooks_ *base = vbase;
+	struct evrpc_pause_list *head = &base->pause_requests;
+	struct evrpc_hook_ctx *pause;
+
+	TAILQ_FOREACH(pause, head, next) {
+		if (pause->ctx == ctx)
+			break;
+	}
+
+	if (pause == NULL)
+		return (-1);
+
+	(*pause->cb)(pause->ctx, res);
+	TAILQ_REMOVE(head, pause, next);
+	mm_free(pause);
+	return (0);
+}
+
+int
+evrpc_make_request(struct evrpc_request_wrapper *ctx)
+{
+	struct evrpc_pool *pool = ctx->pool;
+
+	/* initialize the event structure for this rpc */
+	evtimer_assign(&ctx->ev_timeout, pool->base, evrpc_request_timeout, ctx);
+
+	/* we better have some available connections on the pool */
+	EVUTIL_ASSERT(TAILQ_FIRST(&pool->connections) != NULL);
+
+	/*
+	 * if no connection is available, we queue the request on the pool,
+	 * the next time a connection is empty, the rpc will be send on that.
+	 */
+	TAILQ_INSERT_TAIL(&pool->requests, ctx, next);
+
+	evrpc_pool_schedule(pool);
+
+	return (0);
+}
+
+
+struct evrpc_request_wrapper *
+evrpc_make_request_ctx(
+	struct evrpc_pool *pool, void *request, void *reply,
+	const char *rpcname,
+	void (*req_marshal)(struct evbuffer*, void *),
+	void (*rpl_clear)(void *),
+	int (*rpl_unmarshal)(void *, struct evbuffer *),
+	void (*cb)(struct evrpc_status *, void *, void *, void *),
+	void *cbarg)
+{
+	struct evrpc_request_wrapper *ctx = (struct evrpc_request_wrapper *)
+	    mm_malloc(sizeof(struct evrpc_request_wrapper));
+	if (ctx == NULL)
+		return (NULL);
+
+	ctx->pool = pool;
+	ctx->hook_meta = NULL;
+	ctx->evcon = NULL;
+	ctx->name = mm_strdup(rpcname);
+	if (ctx->name == NULL) {
+		mm_free(ctx);
+		return (NULL);
+	}
+	ctx->cb = cb;
+	ctx->cb_arg = cbarg;
+	ctx->request = request;
+	ctx->reply = reply;
+	ctx->request_marshal = req_marshal;
+	ctx->reply_clear = rpl_clear;
+	ctx->reply_unmarshal = rpl_unmarshal;
+
+	return (ctx);
+}
+
+static void
+evrpc_reply_done_closure(void *, enum EVRPC_HOOK_RESULT);
+
+static void
+evrpc_reply_done(struct evhttp_request *req, void *arg)
+{
+	struct evrpc_request_wrapper *ctx = arg;
+	struct evrpc_pool *pool = ctx->pool;
+	int hook_res = EVRPC_CONTINUE;
+
+	/* cancel any timeout we might have scheduled */
+	event_del(&ctx->ev_timeout);
+
+	ctx->req = req;
+
+	/* we need to get the reply now */
+	if (req == NULL) {
+		evrpc_reply_done_closure(ctx, EVRPC_CONTINUE);
+		return;
+	}
+
+	if (TAILQ_FIRST(&pool->input_hooks) != NULL) {
+		evrpc_hook_associate_meta_(&ctx->hook_meta, ctx->evcon);
+
+		/* apply hooks to the incoming request */
+		hook_res = evrpc_process_hooks(&pool->input_hooks,
+		    ctx, req, req->input_buffer);
+
+		switch (hook_res) {
+		case EVRPC_TERMINATE:
+		case EVRPC_CONTINUE:
+			break;
+		case EVRPC_PAUSE:
+			/*
+			 * if we get paused we also need to know the
+			 * request.  unfortunately, the underlying
+			 * layer is going to free it.  we need to
+			 * request ownership explicitly
+			 */
+			evhttp_request_own(req);
+
+			evrpc_pause_request(pool, ctx,
+			    evrpc_reply_done_closure);
+			return;
+		default:
+			EVUTIL_ASSERT(hook_res == EVRPC_TERMINATE ||
+			    hook_res == EVRPC_CONTINUE ||
+			    hook_res == EVRPC_PAUSE);
+		}
+	}
+
+	evrpc_reply_done_closure(ctx, hook_res);
+
+	/* http request is being freed by underlying layer */
+}
+
+static void
+evrpc_reply_done_closure(void *arg, enum EVRPC_HOOK_RESULT hook_res)
+{
+	struct evrpc_request_wrapper *ctx = arg;
+	struct evhttp_request *req = ctx->req;
+	struct evrpc_pool *pool = ctx->pool;
+	struct evrpc_status status;
+	int res = -1;
+
+	memset(&status, 0, sizeof(status));
+	status.http_req = req;
+
+	/* we need to get the reply now */
+	if (req == NULL) {
+		status.error = EVRPC_STATUS_ERR_TIMEOUT;
+	} else if (hook_res == EVRPC_TERMINATE) {
+		status.error = EVRPC_STATUS_ERR_HOOKABORTED;
+	} else {
+		res = ctx->reply_unmarshal(ctx->reply, req->input_buffer);
+		if (res == -1)
+			status.error = EVRPC_STATUS_ERR_BADPAYLOAD;
+	}
+
+	if (res == -1) {
+		/* clear everything that we might have written previously */
+		ctx->reply_clear(ctx->reply);
+	}
+
+	(*ctx->cb)(&status, ctx->request, ctx->reply, ctx->cb_arg);
+
+	evrpc_request_wrapper_free(ctx);
+
+	/* the http layer owned the original request structure, but if we
+	 * got paused, we asked for ownership and need to free it here. */
+	if (req != NULL && evhttp_request_is_owned(req))
+		evhttp_request_free(req);
+
+	/* see if we can schedule another request */
+	evrpc_pool_schedule(pool);
+}
+
+static void
+evrpc_pool_schedule(struct evrpc_pool *pool)
+{
+	struct evrpc_request_wrapper *ctx = TAILQ_FIRST(&pool->requests);
+	struct evhttp_connection *evcon;
+
+	/* if no requests are pending, we have no work */
+	if (ctx == NULL)
+		return;
+
+	if ((evcon = evrpc_pool_find_connection(pool)) != NULL) {
+		TAILQ_REMOVE(&pool->requests, ctx, next);
+		evrpc_schedule_request(evcon, ctx);
+	}
+}
+
+static void
+evrpc_request_timeout(evutil_socket_t fd, short what, void *arg)
+{
+	struct evrpc_request_wrapper *ctx = arg;
+	struct evhttp_connection *evcon = ctx->evcon;
+	EVUTIL_ASSERT(evcon != NULL);
+
+	evhttp_connection_fail_(evcon, EVREQ_HTTP_TIMEOUT);
+}
+
+/*
+ * frees potential meta data associated with a request.
+ */
+
+static void
+evrpc_meta_data_free(struct evrpc_meta_list *meta_data)
+{
+	struct evrpc_meta *entry;
+	EVUTIL_ASSERT(meta_data != NULL);
+
+	while ((entry = TAILQ_FIRST(meta_data)) != NULL) {
+		TAILQ_REMOVE(meta_data, entry, next);
+		mm_free(entry->key);
+		mm_free(entry->data);
+		mm_free(entry);
+	}
+}
+
+static struct evrpc_hook_meta *
+evrpc_hook_meta_new_(void)
+{
+	struct evrpc_hook_meta *ctx;
+	ctx = mm_malloc(sizeof(struct evrpc_hook_meta));
+	EVUTIL_ASSERT(ctx != NULL);
+
+	TAILQ_INIT(&ctx->meta_data);
+	ctx->evcon = NULL;
+
+	return (ctx);
+}
+
+static void
+evrpc_hook_associate_meta_(struct evrpc_hook_meta **pctx,
+    struct evhttp_connection *evcon)
+{
+	struct evrpc_hook_meta *ctx = *pctx;
+	if (ctx == NULL)
+		*pctx = ctx = evrpc_hook_meta_new_();
+	ctx->evcon = evcon;
+}
+
+static void
+evrpc_hook_context_free_(struct evrpc_hook_meta *ctx)
+{
+	evrpc_meta_data_free(&ctx->meta_data);
+	mm_free(ctx);
+}
+
+/* Adds meta data */
+void
+evrpc_hook_add_meta(void *ctx, const char *key,
+    const void *data, size_t data_size)
+{
+	struct evrpc_request_wrapper *req = ctx;
+	struct evrpc_hook_meta *store = NULL;
+	struct evrpc_meta *meta = NULL;
+
+	if ((store = req->hook_meta) == NULL)
+		store = req->hook_meta = evrpc_hook_meta_new_();
+
+	meta = mm_malloc(sizeof(struct evrpc_meta));
+	EVUTIL_ASSERT(meta != NULL);
+	meta->key = mm_strdup(key);
+	EVUTIL_ASSERT(meta->key != NULL);
+	meta->data_size = data_size;
+	meta->data = mm_malloc(data_size);
+	EVUTIL_ASSERT(meta->data != NULL);
+	memcpy(meta->data, data, data_size);
+
+	TAILQ_INSERT_TAIL(&store->meta_data, meta, next);
+}
+
+int
+evrpc_hook_find_meta(void *ctx, const char *key, void **data, size_t *data_size)
+{
+	struct evrpc_request_wrapper *req = ctx;
+	struct evrpc_meta *meta = NULL;
+
+	if (req->hook_meta == NULL)
+		return (-1);
+
+	TAILQ_FOREACH(meta, &req->hook_meta->meta_data, next) {
+		if (strcmp(meta->key, key) == 0) {
+			*data = meta->data;
+			*data_size = meta->data_size;
+			return (0);
+		}
+	}
+
+	return (-1);
+}
+
+struct evhttp_connection *
+evrpc_hook_get_connection(void *ctx)
+{
+	struct evrpc_request_wrapper *req = ctx;
+	return (req->hook_meta != NULL ? req->hook_meta->evcon : NULL);
+}
+
+int
+evrpc_send_request_generic(struct evrpc_pool *pool,
+    void *request, void *reply,
+    void (*cb)(struct evrpc_status *, void *, void *, void *),
+    void *cb_arg,
+    const char *rpcname,
+    void (*req_marshal)(struct evbuffer *, void *),
+    void (*rpl_clear)(void *),
+    int (*rpl_unmarshal)(void *, struct evbuffer *))
+{
+	struct evrpc_status status;
+	struct evrpc_request_wrapper *ctx;
+	ctx = evrpc_make_request_ctx(pool, request, reply,
+	    rpcname, req_marshal, rpl_clear, rpl_unmarshal, cb, cb_arg);
+	if (ctx == NULL)
+		goto error;
+	return (evrpc_make_request(ctx));
+error:
+	memset(&status, 0, sizeof(status));
+	status.error = EVRPC_STATUS_ERR_UNSTARTED;
+	(*(cb))(&status, request, reply, cb_arg);
+	return (-1);
+}
+
+/** Takes a request object and fills it in with the right magic */
+static struct evrpc *
+evrpc_register_object(const char *name,
+    void *(*req_new)(void*), void *req_new_arg, void (*req_free)(void *),
+    int (*req_unmarshal)(void *, struct evbuffer *),
+    void *(*rpl_new)(void*), void *rpl_new_arg, void (*rpl_free)(void *),
+    int (*rpl_complete)(void *),
+    void (*rpl_marshal)(struct evbuffer *, void *))
+{
+	struct evrpc* rpc = (struct evrpc *)mm_calloc(1, sizeof(struct evrpc));
+	if (rpc == NULL)
+		return (NULL);
+	rpc->uri = mm_strdup(name);
+	if (rpc->uri == NULL) {
+		mm_free(rpc);
+		return (NULL);
+	}
+	rpc->request_new = req_new;
+	rpc->request_new_arg = req_new_arg;
+	rpc->request_free = req_free;
+	rpc->request_unmarshal = req_unmarshal;
+	rpc->reply_new = rpl_new;
+	rpc->reply_new_arg = rpl_new_arg;
+	rpc->reply_free = rpl_free;
+	rpc->reply_complete = rpl_complete;
+	rpc->reply_marshal = rpl_marshal;
+	return (rpc);
+}
+
+int
+evrpc_register_generic(struct evrpc_base *base, const char *name,
+    void (*callback)(struct evrpc_req_generic *, void *), void *cbarg,
+    void *(*req_new)(void *), void *req_new_arg, void (*req_free)(void *),
+    int (*req_unmarshal)(void *, struct evbuffer *),
+    void *(*rpl_new)(void *), void *rpl_new_arg, void (*rpl_free)(void *),
+    int (*rpl_complete)(void *),
+    void (*rpl_marshal)(struct evbuffer *, void *))
+{
+	struct evrpc* rpc =
+	    evrpc_register_object(name, req_new, req_new_arg, req_free, req_unmarshal,
+		rpl_new, rpl_new_arg, rpl_free, rpl_complete, rpl_marshal);
+	if (rpc == NULL)
+		return (-1);
+	evrpc_register_rpc(base, rpc,
+	    (void (*)(struct evrpc_req_generic*, void *))callback, cbarg);
+	return (0);
+}
+
+/** accessors for obscure and undocumented functionality */
+struct evrpc_pool *
+evrpc_request_get_pool(struct evrpc_request_wrapper *ctx)
+{
+	return (ctx->pool);
+}
+
+void
+evrpc_request_set_pool(struct evrpc_request_wrapper *ctx,
+    struct evrpc_pool *pool)
+{
+	ctx->pool = pool;
+}
+
+void
+evrpc_request_set_cb(struct evrpc_request_wrapper *ctx,
+    void (*cb)(struct evrpc_status*, void *request, void *reply, void *arg),
+    void *cb_arg)
+{
+	ctx->cb = cb;
+	ctx->cb_arg = cb_arg;
+}