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/* $OpenBSD: evbuffer_tls.c,v 1.13 2022/03/22 22:58:00 bluhm Exp $ */
/*
* Copyright (c) 2002-2004 Niels Provos <provos@citi.umich.edu>
* Copyright (c) 2014-2015 Alexander Bluhm <bluhm@openbsd.org>
* 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 <sys/time.h>
#include <sys/ioctl.h>
#include <errno.h>
#include <event.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <tls.h>
#include "evbuffer_tls.h"
/* prototypes */
void bufferevent_read_pressure_cb(struct evbuffer *, size_t, size_t, void *);
static void buffertls_readcb(int, short, void *);
static void buffertls_writecb(int, short, void *);
static void buffertls_handshakecb(int, short, void *);
int evtls_read(struct evbuffer *, int, int, struct tls *);
int evtls_write(struct evbuffer *, int, struct tls *);
static int
bufferevent_add(struct event *ev, int timeout)
{
struct timeval tv, *ptv = NULL;
if (timeout) {
timerclear(&tv);
tv.tv_sec = timeout;
ptv = &tv;
}
return (event_add(ev, ptv));
}
static void
buffertls_readcb(int fd, short event, void *arg)
{
struct buffertls *buftls = arg;
struct bufferevent *bufev = buftls->bt_bufev;
struct tls *ctx = buftls->bt_ctx;
int res = 0;
short what = EVBUFFER_READ;
size_t len;
int howmuch = -1;
if (event == EV_TIMEOUT) {
what |= EVBUFFER_TIMEOUT;
goto error;
}
/*
* If we have a high watermark configured then we don't want to
* read more data than would make us reach the watermark.
*/
if (bufev->wm_read.high != 0) {
howmuch = bufev->wm_read.high - EVBUFFER_LENGTH(bufev->input);
/* we might have lowered the watermark, stop reading */
if (howmuch <= 0) {
struct evbuffer *buf = bufev->input;
event_del(&bufev->ev_read);
evbuffer_setcb(buf,
bufferevent_read_pressure_cb, bufev);
return;
}
}
res = evtls_read(bufev->input, fd, howmuch, ctx);
switch (res) {
case TLS_WANT_POLLIN:
bufferevent_add(&bufev->ev_read, bufev->timeout_read);
return;
case TLS_WANT_POLLOUT:
event_del(&bufev->ev_write);
event_set(&bufev->ev_write, fd, EV_WRITE, buffertls_readcb,
buftls);
bufferevent_add(&bufev->ev_write, bufev->timeout_write);
return;
case -1:
what |= EVBUFFER_ERROR;
break;
case 0:
tls_close(ctx);
what |= EVBUFFER_EOF;
break;
}
if (res <= 0)
goto error;
event_del(&bufev->ev_write);
event_set(&bufev->ev_write, fd, EV_WRITE, buffertls_writecb, buftls);
if (bufev->enabled & EV_READ)
bufferevent_add(&bufev->ev_read, bufev->timeout_read);
if (EVBUFFER_LENGTH(bufev->output) != 0 && bufev->enabled & EV_WRITE)
bufferevent_add(&bufev->ev_write, bufev->timeout_write);
/* See if this callbacks meets the water marks */
len = EVBUFFER_LENGTH(bufev->input);
if (bufev->wm_read.low != 0 && len < bufev->wm_read.low)
return;
if (bufev->wm_read.high != 0 && len >= bufev->wm_read.high) {
struct evbuffer *buf = bufev->input;
event_del(&bufev->ev_read);
/* Now schedule a callback for us when the buffer changes */
evbuffer_setcb(buf, bufferevent_read_pressure_cb, bufev);
}
/* Invoke the user callback - must always be called last */
if (bufev->readcb != NULL)
(*bufev->readcb)(bufev, bufev->cbarg);
return;
error:
(*bufev->errorcb)(bufev, what, bufev->cbarg);
}
static void
buffertls_writecb(int fd, short event, void *arg)
{
struct buffertls *buftls = arg;
struct bufferevent *bufev = buftls->bt_bufev;
struct tls *ctx = buftls->bt_ctx;
int res = 0;
short what = EVBUFFER_WRITE;
if (event == EV_TIMEOUT) {
what |= EVBUFFER_TIMEOUT;
goto error;
}
if (EVBUFFER_LENGTH(bufev->output) != 0) {
res = evtls_write(bufev->output, fd, ctx);
switch (res) {
case TLS_WANT_POLLIN:
event_del(&bufev->ev_read);
event_set(&bufev->ev_read, fd, EV_READ,
buffertls_writecb, buftls);
bufferevent_add(&bufev->ev_read, bufev->timeout_read);
return;
case TLS_WANT_POLLOUT:
bufferevent_add(&bufev->ev_write, bufev->timeout_write);
return;
case -1:
what |= EVBUFFER_ERROR;
break;
case 0:
what |= EVBUFFER_EOF;
break;
}
if (res <= 0)
goto error;
}
event_del(&bufev->ev_read);
event_set(&bufev->ev_read, fd, EV_READ, buffertls_readcb, buftls);
if (bufev->enabled & EV_READ)
bufferevent_add(&bufev->ev_read, bufev->timeout_read);
if (EVBUFFER_LENGTH(bufev->output) != 0 && bufev->enabled & EV_WRITE)
bufferevent_add(&bufev->ev_write, bufev->timeout_write);
/*
* Invoke the user callback if our buffer is drained or below the
* low watermark.
*/
if (bufev->writecb != NULL &&
EVBUFFER_LENGTH(bufev->output) <= bufev->wm_write.low)
(*bufev->writecb)(bufev, bufev->cbarg);
return;
error:
(*bufev->errorcb)(bufev, what, bufev->cbarg);
}
static void
buffertls_handshakecb(int fd, short event, void *arg)
{
struct buffertls *buftls = arg;
struct bufferevent *bufev = buftls->bt_bufev;
struct tls *ctx = buftls->bt_ctx;
int res = 0;
short what = EVBUFFER_HANDSHAKE;
if (event == EV_TIMEOUT) {
what |= EVBUFFER_TIMEOUT;
goto error;
}
res = tls_handshake(ctx);
switch (res) {
case TLS_WANT_POLLIN:
bufferevent_add(&bufev->ev_read, bufev->timeout_read);
return;
case TLS_WANT_POLLOUT:
bufferevent_add(&bufev->ev_write, bufev->timeout_write);
return;
case -1:
what |= EVBUFFER_ERROR;
break;
}
if (res == -1)
goto error;
/* Handshake was successful, change to read and write callback. */
event_del(&bufev->ev_read);
event_del(&bufev->ev_write);
event_set(&bufev->ev_read, fd, EV_READ, buffertls_readcb, buftls);
event_set(&bufev->ev_write, fd, EV_WRITE, buffertls_writecb, buftls);
if (bufev->enabled & EV_READ)
bufferevent_add(&bufev->ev_read, bufev->timeout_read);
if (EVBUFFER_LENGTH(bufev->output) != 0 && bufev->enabled & EV_WRITE)
bufferevent_add(&bufev->ev_write, bufev->timeout_write);
return;
error:
(*bufev->errorcb)(bufev, what, bufev->cbarg);
}
void
buffertls_set(struct buffertls *buftls, struct bufferevent *bufev,
struct tls *ctx, int fd)
{
bufferevent_setfd(bufev, fd);
event_set(&bufev->ev_read, fd, EV_READ, buffertls_readcb, buftls);
event_set(&bufev->ev_write, fd, EV_WRITE, buffertls_writecb, buftls);
buftls->bt_bufev = bufev;
buftls->bt_ctx = ctx;
}
void
buffertls_accept(struct buffertls *buftls, int fd)
{
struct bufferevent *bufev = buftls->bt_bufev;
event_del(&bufev->ev_read);
event_del(&bufev->ev_write);
event_set(&bufev->ev_read, fd, EV_READ, buffertls_handshakecb, buftls);
event_set(&bufev->ev_write, fd, EV_WRITE, buffertls_handshakecb,
buftls);
bufferevent_add(&bufev->ev_read, bufev->timeout_read);
}
void
buffertls_connect(struct buffertls *buftls, int fd)
{
struct bufferevent *bufev = buftls->bt_bufev;
event_del(&bufev->ev_read);
event_del(&bufev->ev_write);
event_set(&bufev->ev_read, fd, EV_READ, buffertls_handshakecb, buftls);
event_set(&bufev->ev_write, fd, EV_WRITE, buffertls_handshakecb,
buftls);
bufferevent_add(&bufev->ev_write, bufev->timeout_write);
}
/*
* Reads data from a file descriptor into a buffer.
*/
#define EVBUFFER_MAX_READ 16384
int
evtls_read(struct evbuffer *buf, int fd, int howmuch, struct tls *ctx)
{
u_char *p;
size_t oldoff = buf->off;
int n = EVBUFFER_MAX_READ;
if (howmuch < 0 || howmuch > n)
howmuch = n;
/* If we don't have FIONREAD, we might waste some space here */
if (evbuffer_expand(buf, howmuch) == -1)
return (-1);
/* We can append new data at this point */
p = buf->buffer + buf->off;
n = tls_read(ctx, p, howmuch);
if (n <= 0)
return (n);
buf->off += n;
/* Tell someone about changes in this buffer */
if (buf->off != oldoff && buf->cb != NULL)
(*buf->cb)(buf, oldoff, buf->off, buf->cbarg);
return (n);
}
int
evtls_write(struct evbuffer *buffer, int fd, struct tls *ctx)
{
int n;
n = tls_write(ctx, buffer->buffer, buffer->off);
if (n <= 0)
return (n);
evbuffer_drain(buffer, n);
return (n);
}
|