+++ /dev/null
-/*
- * Copyright (c) 2007-2010 Niels Provos and Nick Mathewson
- * Copyright (c) 2002-2006 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.
- */
-
-#include <sys/types.h>
-
-#include "event2/event-config.h"
-
-#ifdef _EVENT_HAVE_SYS_TIME_H
-#include <sys/time.h>
-#endif
-
-#include <errno.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#ifdef _EVENT_HAVE_STDARG_H
-#include <stdarg.h>
-#endif
-
-#ifdef WIN32
-#include <winsock2.h>
-#endif
-
-#include "event2/util.h"
-#include "event2/bufferevent.h"
-#include "event2/buffer.h"
-#include "event2/bufferevent_struct.h"
-#include "event2/event.h"
-#include "log-internal.h"
-#include "mm-internal.h"
-#include "bufferevent-internal.h"
-#include "util-internal.h"
-
-/* prototypes */
-static int be_filter_enable(struct bufferevent *, short);
-static int be_filter_disable(struct bufferevent *, short);
-static void be_filter_destruct(struct bufferevent *);
-
-static void be_filter_readcb(struct bufferevent *, void *);
-static void be_filter_writecb(struct bufferevent *, void *);
-static void be_filter_eventcb(struct bufferevent *, short, void *);
-static int be_filter_flush(struct bufferevent *bufev,
- short iotype, enum bufferevent_flush_mode mode);
-static int be_filter_ctrl(struct bufferevent *, enum bufferevent_ctrl_op, union bufferevent_ctrl_data *);
-
-static void bufferevent_filtered_outbuf_cb(struct evbuffer *buf,
- const struct evbuffer_cb_info *info, void *arg);
-
-struct bufferevent_filtered {
- struct bufferevent_private bev;
-
- /** The bufferevent that we read/write filtered data from/to. */
- struct bufferevent *underlying;
- /** A callback on our outbuf to notice when somebody adds data */
- struct evbuffer_cb_entry *outbuf_cb;
- /** True iff we have received an EOF callback from the underlying
- * bufferevent. */
- unsigned got_eof;
-
- /** Function to free context when we're done. */
- void (*free_context)(void *);
- /** Input filter */
- bufferevent_filter_cb process_in;
- /** Output filter */
- bufferevent_filter_cb process_out;
- /** User-supplied argument to the filters. */
- void *context;
-};
-
-const struct bufferevent_ops bufferevent_ops_filter = {
- "filter",
- evutil_offsetof(struct bufferevent_filtered, bev.bev),
- be_filter_enable,
- be_filter_disable,
- be_filter_destruct,
- _bufferevent_generic_adj_timeouts,
- be_filter_flush,
- be_filter_ctrl,
-};
-
-/* Given a bufferevent that's really the bev filter of a bufferevent_filtered,
- * return that bufferevent_filtered. Returns NULL otherwise.*/
-static inline struct bufferevent_filtered *
-upcast(struct bufferevent *bev)
-{
- struct bufferevent_filtered *bev_f;
- if (bev->be_ops != &bufferevent_ops_filter)
- return NULL;
- bev_f = (void*)( ((char*)bev) -
- evutil_offsetof(struct bufferevent_filtered, bev.bev));
- EVUTIL_ASSERT(bev_f->bev.bev.be_ops == &bufferevent_ops_filter);
- return bev_f;
-}
-
-#define downcast(bev_f) (&(bev_f)->bev.bev)
-
-/** Return 1 iff bevf's underlying bufferevent's output buffer is at or
- * over its high watermark such that we should not write to it in a given
- * flush mode. */
-static int
-be_underlying_writebuf_full(struct bufferevent_filtered *bevf,
- enum bufferevent_flush_mode state)
-{
- struct bufferevent *u = bevf->underlying;
- return state == BEV_NORMAL &&
- u->wm_write.high &&
- evbuffer_get_length(u->output) >= u->wm_write.high;
-}
-
-/** Return 1 if our input buffer is at or over its high watermark such that we
- * should not write to it in a given flush mode. */
-static int
-be_readbuf_full(struct bufferevent_filtered *bevf,
- enum bufferevent_flush_mode state)
-{
- struct bufferevent *bufev = downcast(bevf);
- return state == BEV_NORMAL &&
- bufev->wm_read.high &&
- evbuffer_get_length(bufev->input) >= bufev->wm_read.high;
-}
-
-
-/* Filter to use when we're created with a NULL filter. */
-static enum bufferevent_filter_result
-be_null_filter(struct evbuffer *src, struct evbuffer *dst, ev_ssize_t lim,
- enum bufferevent_flush_mode state, void *ctx)
-{
- (void)state;
- if (evbuffer_remove_buffer(src, dst, lim) == 0)
- return BEV_OK;
- else
- return BEV_ERROR;
-}
-
-struct bufferevent *
-bufferevent_filter_new(struct bufferevent *underlying,
- bufferevent_filter_cb input_filter,
- bufferevent_filter_cb output_filter,
- int options,
- void (*free_context)(void *),
- void *ctx)
-{
- struct bufferevent_filtered *bufev_f;
- int tmp_options = options & ~BEV_OPT_THREADSAFE;
-
- if (!underlying)
- return NULL;
-
- if (!input_filter)
- input_filter = be_null_filter;
- if (!output_filter)
- output_filter = be_null_filter;
-
- bufev_f = mm_calloc(1, sizeof(struct bufferevent_filtered));
- if (!bufev_f)
- return NULL;
-
- if (bufferevent_init_common(&bufev_f->bev, underlying->ev_base,
- &bufferevent_ops_filter, tmp_options) < 0) {
- mm_free(bufev_f);
- return NULL;
- }
- if (options & BEV_OPT_THREADSAFE) {
- bufferevent_enable_locking(downcast(bufev_f), NULL);
- }
-
- bufev_f->underlying = underlying;
-
- bufev_f->process_in = input_filter;
- bufev_f->process_out = output_filter;
- bufev_f->free_context = free_context;
- bufev_f->context = ctx;
-
- bufferevent_setcb(bufev_f->underlying,
- be_filter_readcb, be_filter_writecb, be_filter_eventcb, bufev_f);
-
- bufev_f->outbuf_cb = evbuffer_add_cb(downcast(bufev_f)->output,
- bufferevent_filtered_outbuf_cb, bufev_f);
-
- _bufferevent_init_generic_timeout_cbs(downcast(bufev_f));
- bufferevent_incref(underlying);
-
- bufferevent_enable(underlying, EV_READ|EV_WRITE);
- bufferevent_suspend_read(underlying, BEV_SUSPEND_FILT_READ);
-
- return downcast(bufev_f);
-}
-
-static void
-be_filter_destruct(struct bufferevent *bev)
-{
- struct bufferevent_filtered *bevf = upcast(bev);
- EVUTIL_ASSERT(bevf);
- if (bevf->free_context)
- bevf->free_context(bevf->context);
-
- if (bevf->bev.options & BEV_OPT_CLOSE_ON_FREE) {
- /* Yes, there is also a decref in bufferevent_decref.
- * That decref corresponds to the incref when we set
- * underlying for the first time. This decref is an
- * extra one to remove the last reference.
- */
- if (BEV_UPCAST(bevf->underlying)->refcnt < 2) {
- event_warnx("BEV_OPT_CLOSE_ON_FREE set on an "
- "bufferevent with too few references");
- } else {
- bufferevent_free(bevf->underlying);
- }
- } else {
- if (bevf->underlying) {
- if (bevf->underlying->errorcb == be_filter_eventcb)
- bufferevent_setcb(bevf->underlying,
- NULL, NULL, NULL, NULL);
- bufferevent_unsuspend_read(bevf->underlying,
- BEV_SUSPEND_FILT_READ);
- }
- }
-
- _bufferevent_del_generic_timeout_cbs(bev);
-}
-
-static int
-be_filter_enable(struct bufferevent *bev, short event)
-{
- struct bufferevent_filtered *bevf = upcast(bev);
- if (event & EV_WRITE)
- BEV_RESET_GENERIC_WRITE_TIMEOUT(bev);
-
- if (event & EV_READ) {
- BEV_RESET_GENERIC_READ_TIMEOUT(bev);
- bufferevent_unsuspend_read(bevf->underlying,
- BEV_SUSPEND_FILT_READ);
- }
- return 0;
-}
-
-static int
-be_filter_disable(struct bufferevent *bev, short event)
-{
- struct bufferevent_filtered *bevf = upcast(bev);
- if (event & EV_WRITE)
- BEV_DEL_GENERIC_WRITE_TIMEOUT(bev);
- if (event & EV_READ) {
- BEV_DEL_GENERIC_READ_TIMEOUT(bev);
- bufferevent_suspend_read(bevf->underlying,
- BEV_SUSPEND_FILT_READ);
- }
- return 0;
-}
-
-static enum bufferevent_filter_result
-be_filter_process_input(struct bufferevent_filtered *bevf,
- enum bufferevent_flush_mode state,
- int *processed_out)
-{
- enum bufferevent_filter_result res;
- struct bufferevent *bev = downcast(bevf);
-
- if (state == BEV_NORMAL) {
- /* If we're in 'normal' mode, don't urge data on the filter
- * unless we're reading data and under our high-water mark.*/
- if (!(bev->enabled & EV_READ) ||
- be_readbuf_full(bevf, state))
- return BEV_OK;
- }
-
- do {
- ev_ssize_t limit = -1;
- if (state == BEV_NORMAL && bev->wm_read.high)
- limit = bev->wm_read.high -
- evbuffer_get_length(bev->input);
-
- res = bevf->process_in(bevf->underlying->input,
- bev->input, limit, state, bevf->context);
-
- if (res == BEV_OK)
- *processed_out = 1;
- } while (res == BEV_OK &&
- (bev->enabled & EV_READ) &&
- evbuffer_get_length(bevf->underlying->input) &&
- !be_readbuf_full(bevf, state));
-
- if (*processed_out)
- BEV_RESET_GENERIC_READ_TIMEOUT(bev);
-
- return res;
-}
-
-
-static enum bufferevent_filter_result
-be_filter_process_output(struct bufferevent_filtered *bevf,
- enum bufferevent_flush_mode state,
- int *processed_out)
-{
- /* Requires references and lock: might call writecb */
- enum bufferevent_filter_result res = BEV_OK;
- struct bufferevent *bufev = downcast(bevf);
- int again = 0;
-
- if (state == BEV_NORMAL) {
- /* If we're in 'normal' mode, don't urge data on the
- * filter unless we're writing data, and the underlying
- * bufferevent is accepting data, and we have data to
- * give the filter. If we're in 'flush' or 'finish',
- * call the filter no matter what. */
- if (!(bufev->enabled & EV_WRITE) ||
- be_underlying_writebuf_full(bevf, state) ||
- !evbuffer_get_length(bufev->output))
- return BEV_OK;
- }
-
- /* disable the callback that calls this function
- when the user adds to the output buffer. */
- evbuffer_cb_set_flags(bufev->output, bevf->outbuf_cb, 0);
-
- do {
- int processed = 0;
- again = 0;
-
- do {
- ev_ssize_t limit = -1;
- if (state == BEV_NORMAL &&
- bevf->underlying->wm_write.high)
- limit = bevf->underlying->wm_write.high -
- evbuffer_get_length(bevf->underlying->output);
-
- res = bevf->process_out(downcast(bevf)->output,
- bevf->underlying->output,
- limit,
- state,
- bevf->context);
-
- if (res == BEV_OK)
- processed = *processed_out = 1;
- } while (/* Stop if the filter wasn't successful...*/
- res == BEV_OK &&
- /* Or if we aren't writing any more. */
- (bufev->enabled & EV_WRITE) &&
- /* Of if we have nothing more to write and we are
- * not flushing. */
- evbuffer_get_length(bufev->output) &&
- /* Or if we have filled the underlying output buffer. */
- !be_underlying_writebuf_full(bevf,state));
-
- if (processed &&
- evbuffer_get_length(bufev->output) <= bufev->wm_write.low) {
- /* call the write callback.*/
- _bufferevent_run_writecb(bufev);
-
- if (res == BEV_OK &&
- (bufev->enabled & EV_WRITE) &&
- evbuffer_get_length(bufev->output) &&
- !be_underlying_writebuf_full(bevf, state)) {
- again = 1;
- }
- }
- } while (again);
-
- /* reenable the outbuf_cb */
- evbuffer_cb_set_flags(bufev->output,bevf->outbuf_cb,
- EVBUFFER_CB_ENABLED);
-
- if (*processed_out)
- BEV_RESET_GENERIC_WRITE_TIMEOUT(bufev);
-
- return res;
-}
-
-/* Called when the size of our outbuf changes. */
-static void
-bufferevent_filtered_outbuf_cb(struct evbuffer *buf,
- const struct evbuffer_cb_info *cbinfo, void *arg)
-{
- struct bufferevent_filtered *bevf = arg;
- struct bufferevent *bev = downcast(bevf);
-
- if (cbinfo->n_added) {
- int processed_any = 0;
- /* Somebody added more data to the output buffer. Try to
- * process it, if we should. */
- _bufferevent_incref_and_lock(bev);
- be_filter_process_output(bevf, BEV_NORMAL, &processed_any);
- _bufferevent_decref_and_unlock(bev);
- }
-}
-
-/* Called when the underlying socket has read. */
-static void
-be_filter_readcb(struct bufferevent *underlying, void *_me)
-{
- struct bufferevent_filtered *bevf = _me;
- enum bufferevent_filter_result res;
- enum bufferevent_flush_mode state;
- struct bufferevent *bufev = downcast(bevf);
- int processed_any = 0;
-
- _bufferevent_incref_and_lock(bufev);
-
- if (bevf->got_eof)
- state = BEV_FINISHED;
- else
- state = BEV_NORMAL;
-
- /* XXXX use return value */
- res = be_filter_process_input(bevf, state, &processed_any);
- (void)res;
-
- /* XXX This should be in process_input, not here. There are
- * other places that can call process-input, and they should
- * force readcb calls as needed. */
- if (processed_any &&
- evbuffer_get_length(bufev->input) >= bufev->wm_read.low)
- _bufferevent_run_readcb(bufev);
-
- _bufferevent_decref_and_unlock(bufev);
-}
-
-/* Called when the underlying socket has drained enough that we can write to
- it. */
-static void
-be_filter_writecb(struct bufferevent *underlying, void *_me)
-{
- struct bufferevent_filtered *bevf = _me;
- struct bufferevent *bev = downcast(bevf);
- int processed_any = 0;
-
- _bufferevent_incref_and_lock(bev);
- be_filter_process_output(bevf, BEV_NORMAL, &processed_any);
- _bufferevent_decref_and_unlock(bev);
-}
-
-/* Called when the underlying socket has given us an error */
-static void
-be_filter_eventcb(struct bufferevent *underlying, short what, void *_me)
-{
- struct bufferevent_filtered *bevf = _me;
- struct bufferevent *bev = downcast(bevf);
-
- _bufferevent_incref_and_lock(bev);
- /* All we can really to is tell our own eventcb. */
- _bufferevent_run_eventcb(bev, what);
- _bufferevent_decref_and_unlock(bev);
-}
-
-static int
-be_filter_flush(struct bufferevent *bufev,
- short iotype, enum bufferevent_flush_mode mode)
-{
- struct bufferevent_filtered *bevf = upcast(bufev);
- int processed_any = 0;
- EVUTIL_ASSERT(bevf);
-
- _bufferevent_incref_and_lock(bufev);
-
- if (iotype & EV_READ) {
- be_filter_process_input(bevf, mode, &processed_any);
- }
- if (iotype & EV_WRITE) {
- be_filter_process_output(bevf, mode, &processed_any);
- }
- /* XXX check the return value? */
- /* XXX does this want to recursively call lower-level flushes? */
- bufferevent_flush(bevf->underlying, iotype, mode);
-
- _bufferevent_decref_and_unlock(bufev);
-
- return processed_any;
-}
-
-static int
-be_filter_ctrl(struct bufferevent *bev, enum bufferevent_ctrl_op op,
- union bufferevent_ctrl_data *data)
-{
- struct bufferevent_filtered *bevf;
- switch (op) {
- case BEV_CTRL_GET_UNDERLYING:
- bevf = upcast(bev);
- data->ptr = bevf->underlying;
- return 0;
- case BEV_CTRL_GET_FD:
- case BEV_CTRL_SET_FD:
- default:
- return -1;
- }
-}
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