blob: 070fd9e710c575d2832259789d3db6de13d26144 [file] [log] [blame]
/*
* Copyright (c) 2000-2004 Niels Provos <provos@citi.umich.edu>
* All rights reserved.
*
* 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#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 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 <assert.h>
#include "event.h"
#include "evrpc.h"
#include "evrpc-internal.h"
#include "evhttp.h"
#include "evutil.h"
#include "log.h"
struct evrpc_base *
evrpc_init(struct evhttp *http_server)
{
struct evrpc_base* base = 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);
base->http_server = http_server;
return (base);
}
void
evrpc_free(struct evrpc_base *base)
{
struct evrpc *rpc;
struct evrpc_hook *hook;
while ((rpc = TAILQ_FIRST(&base->registered_rpcs)) != NULL) {
assert(evrpc_unregister_rpc(base, rpc->uri));
}
while ((hook = TAILQ_FIRST(&base->input_hooks)) != NULL) {
assert(evrpc_remove_hook(base, EVRPC_INPUT, hook));
}
while ((hook = TAILQ_FIRST(&base->output_hooks)) != NULL) {
assert(evrpc_remove_hook(base, EVRPC_OUTPUT, hook));
}
free(base);
}
void *
evrpc_add_hook(void *vbase,
enum EVRPC_HOOK_TYPE hook_type,
int (*cb)(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:
assert(hook_type == EVRPC_INPUT || hook_type == EVRPC_OUTPUT);
}
hook = calloc(1, sizeof(struct evrpc_hook));
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);
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:
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,
struct evhttp_request *req, struct evbuffer *evbuf)
{
struct evrpc_hook *hook;
TAILQ_FOREACH(hook, head, next) {
if (hook->process(req, evbuf, hook->process_arg) == -1)
return (-1);
}
return (0);
}
static void evrpc_pool_schedule(struct evrpc_pool *pool);
static void evrpc_request_cb(struct evhttp_request *, void *);
void evrpc_request_done(struct evrpc_req_generic*);
/*
* 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;
int constructed_uri_len;
constructed_uri_len = strlen(EVRPC_URI_PREFIX) + strlen(uri) + 1;
if ((constructed_uri = 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);
free(constructed_uri);
return (0);
}
int
evrpc_unregister_rpc(struct evrpc_base *base, const char *name)
{
char *registered_uri = NULL;
struct evrpc *rpc;
/* 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);
free((char *)rpc->uri);
free(rpc);
registered_uri = evrpc_construct_uri(name);
/* remove the http server callback */
assert(evhttp_del_cb(base->http_server, registered_uri) == 0);
free(registered_uri);
return (0);
}
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_LENGTH(req->input_buffer) <= 0)
goto error;
/*
* we might want to allow hooks to suspend the processing,
* but at the moment, we assume that they just act as simple
* filters.
*/
if (evrpc_process_hooks(&rpc->base->input_hooks,
req, req->input_buffer) == -1)
goto error;
rpc_state = calloc(1, sizeof(struct evrpc_req_generic));
if (rpc_state == NULL)
goto error;
/* let's check that we can parse the request */
rpc_state->request = rpc->request_new();
if (rpc_state->request == NULL)
goto error;
rpc_state->rpc = rpc;
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();
if (rpc_state->reply == NULL)
goto error;
rpc_state->http_req = req;
rpc_state->done = evrpc_request_done;
/* 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, "Service Error");
return;
}
void
evrpc_reqstate_free(struct evrpc_req_generic* rpc_state)
{
/* clean up all memory */
if (rpc_state != NULL) {
struct evrpc *rpc = rpc_state->rpc;
if (rpc_state->request != NULL)
rpc->request_free(rpc_state->request);
if (rpc_state->reply != NULL)
rpc->reply_free(rpc_state->reply);
free(rpc_state);
}
}
void
evrpc_request_done(struct evrpc_req_generic* rpc_state)
{
struct evhttp_request *req = rpc_state->http_req;
struct evrpc *rpc = rpc_state->rpc;
struct evbuffer* data = NULL;
if (rpc->reply_complete(rpc_state->reply) == -1) {
/* the reply was not completely filled in. error out */
goto error;
}
if ((data = evbuffer_new()) == NULL) {
/* out of memory */
goto error;
}
/* serialize the reply */
rpc->reply_marshal(data, rpc_state->reply);
/* do hook based tweaks to the request */
if (evrpc_process_hooks(&rpc->base->output_hooks,
req, data) == -1)
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", data);
evbuffer_free(data);
evrpc_reqstate_free(rpc_state);
return;
error:
if (data != NULL)
evbuffer_free(data);
evrpc_reqstate_free(rpc_state);
evhttp_send_error(req, HTTP_SERVUNAVAIL, "Service Error");
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 = calloc(1, sizeof(struct evrpc_pool));
if (pool == NULL)
return (NULL);
TAILQ_INIT(&pool->connections);
TAILQ_INIT(&pool->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)
{
free(request->name);
free(request);
}
void
evrpc_pool_free(struct evrpc_pool *pool)
{
struct evhttp_connection *connection;
struct evrpc_request_wrapper *request;
struct evrpc_hook *hook;
while ((request = TAILQ_FIRST(&pool->requests)) != NULL) {
TAILQ_REMOVE(&pool->requests, request, next);
/* if this gets more complicated we need our own function */
evrpc_request_wrapper_free(request);
}
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) {
assert(evrpc_remove_hook(pool, EVRPC_INPUT, hook));
}
while ((hook = TAILQ_FIRST(&pool->output_hooks)) != NULL) {
assert(evrpc_remove_hook(pool, EVRPC_OUTPUT, hook));
}
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) {
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 (connection->timeout == -1)
connection->timeout = 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_set_timeout(struct evrpc_pool *pool, int timeout_in_secs)
{
struct evhttp_connection *evcon;
TAILQ_FOREACH(evcon, &pool->connections, next) {
evcon->timeout = timeout_in_secs;
}
pool->timeout = timeout_in_secs;
}
static void evrpc_reply_done(struct evhttp_request *, void *);
static void evrpc_request_timeout(int, 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);
}
/*
* 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;
char *uri = NULL;
int res = 0;
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);
uri = evrpc_construct_uri(ctx->name);
if (uri == NULL)
goto error;
/* we need to know the connection that we might have to abort */
ctx->evcon = connection;
/* apply hooks to the outgoing request */
if (evrpc_process_hooks(&pool->output_hooks,
req, req->output_buffer) == -1)
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);
free(uri);
if (res == -1)
goto error;
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);
}
int
evrpc_make_request(struct evrpc_request_wrapper *ctx)
{
struct evrpc_pool *pool = ctx->pool;
/* initialize the event structure for this rpc */
evtimer_set(&ctx->ev_timeout, evrpc_request_timeout, ctx);
if (pool->base != NULL)
event_base_set(pool->base, &ctx->ev_timeout);
/* we better have some available connections on the pool */
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);
}
static void
evrpc_reply_done(struct evhttp_request *req, void *arg)
{
struct evrpc_request_wrapper *ctx = arg;
struct evrpc_pool *pool = ctx->pool;
struct evrpc_status status;
int res = -1;
/* cancel any timeout we might have scheduled */
event_del(&ctx->ev_timeout);
memset(&status, 0, sizeof(status));
status.http_req = req;
/* we need to get the reply now */
if (req != NULL) {
/* apply hooks to the incoming request */
if (evrpc_process_hooks(&pool->input_hooks,
req, req->input_buffer) == -1) {
status.error = EVRPC_STATUS_ERR_HOOKABORTED;
res = -1;
} else {
res = ctx->reply_unmarshal(ctx->reply,
req->input_buffer);
if (res == -1) {
status.error = EVRPC_STATUS_ERR_BADPAYLOAD;
}
}
} else {
status.error = EVRPC_STATUS_ERR_TIMEOUT;
}
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 owns the request structure */
/* 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(int fd, short what, void *arg)
{
struct evrpc_request_wrapper *ctx = arg;
struct evhttp_connection *evcon = ctx->evcon;
assert(evcon != NULL);
evhttp_connection_fail(evcon, EVCON_HTTP_TIMEOUT);
}