| /* |
| * Copyright (c) 2007-2012 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: |
| case BEV_CTRL_CANCEL_ALL: |
| default: |
| return -1; |
| } |
| } |