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libwebsockets/lib/core-net/service.c
2019-08-12 06:18:04 +01:00

708 lines
18 KiB
C

/*
* libwebsockets - small server side websockets and web server implementation
*
* Copyright (C) 2010-2018 Andy Green <andy@warmcat.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation:
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301 USA
*/
#include "core/private.h"
int
lws_callback_as_writeable(struct lws *wsi)
{
struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
int n, m;
lws_stats_bump(pt, LWSSTATS_C_WRITEABLE_CB, 1);
#if defined(LWS_WITH_STATS)
if (wsi->active_writable_req_us) {
uint64_t ul = lws_now_usecs() -
wsi->active_writable_req_us;
lws_stats_bump(pt, LWSSTATS_US_WRITABLE_DELAY_AVG, ul);
lws_stats_max(pt, LWSSTATS_US_WORST_WRITABLE_DELAY, ul);
wsi->active_writable_req_us = 0;
}
#endif
n = wsi->role_ops->writeable_cb[lwsi_role_server(wsi)];
m = user_callback_handle_rxflow(wsi->protocol->callback,
wsi, (enum lws_callback_reasons) n,
wsi->user_space, NULL, 0);
return m;
}
LWS_VISIBLE int
lws_handle_POLLOUT_event(struct lws *wsi, struct lws_pollfd *pollfd)
{
volatile struct lws *vwsi = (volatile struct lws *)wsi;
int n;
// lwsl_notice("%s: %p\n", __func__, wsi);
vwsi->leave_pollout_active = 0;
vwsi->handling_pollout = 1;
/*
* if another thread wants POLLOUT on us, from here on while
* handling_pollout is set, he will only set leave_pollout_active.
* If we are going to disable POLLOUT, we will check that first.
*/
wsi->could_have_pending = 0; /* clear back-to-back write detection */
/*
* user callback is lowest priority to get these notifications
* actually, since other pending things cannot be disordered
*
* Priority 1: pending truncated sends are incomplete ws fragments
* If anything else sent first the protocol would be
* corrupted.
*
* These are post- any compression transform
*/
if (lws_has_buffered_out(wsi)) {
//lwsl_notice("%s: completing partial\n", __func__);
if (lws_issue_raw(wsi, NULL, 0) < 0) {
lwsl_info("%s signalling to close\n", __func__);
goto bail_die;
}
/* leave POLLOUT active either way */
goto bail_ok;
} else
if (lwsi_state(wsi) == LRS_FLUSHING_BEFORE_CLOSE) {
wsi->socket_is_permanently_unusable = 1;
goto bail_die; /* retry closing now */
}
/* Priority 2: pre- compression transform */
#if defined(LWS_WITH_HTTP_STREAM_COMPRESSION)
if (wsi->http.comp_ctx.buflist_comp ||
wsi->http.comp_ctx.may_have_more) {
enum lws_write_protocol wp = LWS_WRITE_HTTP;
lwsl_info("%s: completing comp partial (buflist_comp %p, may %d)\n",
__func__, wsi->http.comp_ctx.buflist_comp,
wsi->http.comp_ctx.may_have_more
);
if (wsi->role_ops->write_role_protocol(wsi, NULL, 0, &wp) < 0) {
lwsl_info("%s signalling to close\n", __func__);
goto bail_die;
}
lws_callback_on_writable(wsi);
goto bail_ok;
}
#endif
#ifdef LWS_WITH_CGI
/*
* A cgi master's wire protocol remains h1 or h2. He is just getting
* his data from his child cgis.
*/
if (wsi->http.cgi) {
/* also one shot */
if (pollfd)
if (lws_change_pollfd(wsi, LWS_POLLOUT, 0)) {
lwsl_info("failed at set pollfd\n");
return 1;
}
goto user_service_go_again;
}
#endif
/* if we got here, we should have wire protocol ops set on the wsi */
assert(wsi->role_ops);
if (!wsi->role_ops->handle_POLLOUT)
goto bail_ok;
switch ((wsi->role_ops->handle_POLLOUT)(wsi)) {
case LWS_HP_RET_BAIL_OK:
goto bail_ok;
case LWS_HP_RET_BAIL_DIE:
goto bail_die;
case LWS_HP_RET_USER_SERVICE:
break;
default:
assert(0);
}
/* one shot */
if (pollfd) {
int eff = vwsi->leave_pollout_active;
if (!eff) {
if (lws_change_pollfd(wsi, LWS_POLLOUT, 0)) {
lwsl_info("failed at set pollfd\n");
goto bail_die;
}
}
vwsi->handling_pollout = 0;
/* cannot get leave_pollout_active set after the above */
if (!eff && wsi->leave_pollout_active) {
/*
* got set inbetween sampling eff and clearing
* handling_pollout, force POLLOUT on
*/
lwsl_debug("leave_pollout_active\n");
if (lws_change_pollfd(wsi, 0, LWS_POLLOUT)) {
lwsl_info("failed at set pollfd\n");
goto bail_die;
}
}
vwsi->leave_pollout_active = 0;
}
if (lwsi_role_client(wsi) && !wsi->hdr_parsing_completed &&
lwsi_state(wsi) != LRS_H2_WAITING_TO_SEND_HEADERS &&
lwsi_state(wsi) != LRS_ISSUE_HTTP_BODY)
goto bail_ok;
#ifdef LWS_WITH_CGI
user_service_go_again:
#endif
if (wsi->role_ops->perform_user_POLLOUT) {
if (wsi->role_ops->perform_user_POLLOUT(wsi) == -1)
goto bail_die;
else
goto bail_ok;
}
lwsl_debug("%s: %p: non mux: wsistate 0x%lx, ops %s\n", __func__, wsi,
(unsigned long)wsi->wsistate, wsi->role_ops->name);
vwsi = (volatile struct lws *)wsi;
vwsi->leave_pollout_active = 0;
n = lws_callback_as_writeable(wsi);
vwsi->handling_pollout = 0;
if (vwsi->leave_pollout_active)
if (lws_change_pollfd(wsi, 0, LWS_POLLOUT))
goto bail_die;
return n;
/*
* since these don't disable the POLLOUT, they are always doing the
* right thing for leave_pollout_active whether it was set or not.
*/
bail_ok:
vwsi->handling_pollout = 0;
vwsi->leave_pollout_active = 0;
return 0;
bail_die:
vwsi->handling_pollout = 0;
vwsi->leave_pollout_active = 0;
return -1;
}
int
lws_rxflow_cache(struct lws *wsi, unsigned char *buf, int n, int len)
{
struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
uint8_t *buffered;
size_t blen;
int ret = LWSRXFC_CACHED, m;
/* his RX is flowcontrolled, don't send remaining now */
blen = lws_buflist_next_segment_len(&wsi->buflist, &buffered);
if (blen) {
if (buf >= buffered && buf + len <= buffered + blen &&
blen != (size_t)len) {
/*
* rxflow while we were spilling prev rxflow
*
* len indicates how much was unused, then... so trim
* the head buflist to match that situation
*/
lws_buflist_use_segment(&wsi->buflist, blen - len);
lwsl_debug("%s: trim existing rxflow %d -> %d\n",
__func__, (int)blen, (int)len);
return LWSRXFC_TRIMMED;
}
ret = LWSRXFC_ADDITIONAL;
}
/* a new rxflow, buffer it and warn caller */
m = lws_buflist_append_segment(&wsi->buflist, buf + n, len - n);
if (m < 0)
return LWSRXFC_ERROR;
if (m) {
lwsl_debug("%s: added %p to rxflow list\n", __func__, wsi);
lws_dll2_add_head(&wsi->dll_buflist, &pt->dll_buflist_owner);
}
return ret;
}
/* this is used by the platform service code to stop us waiting for network
* activity in poll() when we have something that already needs service
*/
LWS_VISIBLE LWS_EXTERN int
lws_service_adjust_timeout(struct lws_context *context, int timeout_ms, int tsi)
{
struct lws_context_per_thread *pt = &context->pt[tsi];
/*
* Figure out if we really want to wait in poll()... we only need to
* wait if really nothing already to do and we have to wait for
* something from network
*/
#if defined(LWS_ROLE_WS) && !defined(LWS_WITHOUT_EXTENSIONS)
/* 1) if we know we are draining rx ext, do not wait in poll */
if (pt->ws.rx_draining_ext_list)
return 0;
#endif
#if defined(LWS_WITH_TLS)
/* 2) if we know we have non-network pending data,
* do not wait in poll */
if (pt->context->tls_ops &&
pt->context->tls_ops->fake_POLLIN_for_buffered &&
pt->context->tls_ops->fake_POLLIN_for_buffered(pt))
return 0;
#endif
/*
* 4) If there is any wsi with rxflow buffered and in a state to process
* it, we should not wait in poll
*/
lws_start_foreach_dll(struct lws_dll2 *, d, pt->dll_buflist_owner.head) {
struct lws *wsi = lws_container_of(d, struct lws, dll_buflist);
if (!lws_is_flowcontrolled(wsi) &&
lwsi_state(wsi) != LRS_DEFERRING_ACTION)
return 0;
/*
* 5) If any guys with http compression to spill, we shouldn't wait in
* poll but hurry along and service them
*/
} lws_end_foreach_dll(d);
return timeout_ms;
}
/*
* POLLIN said there is something... we must read it, and either use it; or
* if other material already in the buflist append it and return the buflist
* head material.
*/
int
lws_buflist_aware_read(struct lws_context_per_thread *pt, struct lws *wsi,
struct lws_tokens *ebuf)
{
int n, prior = (int)lws_buflist_next_segment_len(&wsi->buflist, NULL);
ebuf->token = pt->serv_buf;
ebuf->len = lws_ssl_capable_read(wsi, pt->serv_buf,
wsi->context->pt_serv_buf_size);
if (ebuf->len == LWS_SSL_CAPABLE_MORE_SERVICE && prior)
goto get_from_buflist;
if (ebuf->len <= 0)
return 0;
/* nothing in buflist already? Then just use what we read */
if (!prior)
return 0;
/* stash what we read */
n = lws_buflist_append_segment(&wsi->buflist, ebuf->token,
ebuf->len);
if (n < 0)
return -1;
if (n) {
lwsl_debug("%s: added %p to rxflow list\n", __func__, wsi);
lws_dll2_add_head(&wsi->dll_buflist, &pt->dll_buflist_owner);
}
/* get the first buflist guy in line */
get_from_buflist:
ebuf->len = (int)lws_buflist_next_segment_len(&wsi->buflist,
&ebuf->token);
return 1; /* came from buflist */
}
int
lws_buflist_aware_consume(struct lws *wsi, struct lws_tokens *ebuf, int used,
int buffered)
{
struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
int m;
/* it's in the buflist; we didn't use any */
if (!used && buffered)
return 0;
if (used && buffered) {
m = lws_buflist_use_segment(&wsi->buflist, used);
lwsl_info("%s: draining rxflow: used %d, next %d\n",
__func__, used, m);
if (m)
return 0;
lwsl_info("%s: removed %p from dll_buflist\n", __func__, wsi);
lws_dll2_remove(&wsi->dll_buflist);
return 0;
}
/* any remainder goes on the buflist */
if (used != ebuf->len) {
m = lws_buflist_append_segment(&wsi->buflist,
ebuf->token + used,
ebuf->len - used);
if (m < 0)
return 1; /* OOM */
if (m) {
lwsl_debug("%s: added %p to rxflow list\n",
__func__, wsi);
lws_dll2_add_head(&wsi->dll_buflist,
&pt->dll_buflist_owner);
}
}
return 0;
}
void
lws_service_do_ripe_rxflow(struct lws_context_per_thread *pt)
{
struct lws_pollfd pfd;
if (!pt->dll_buflist_owner.head)
return;
/*
* service all guys with pending rxflow that reached a state they can
* accept the pending data
*/
lws_pt_lock(pt, __func__);
lws_start_foreach_dll_safe(struct lws_dll2 *, d, d1,
pt->dll_buflist_owner.head) {
struct lws *wsi = lws_container_of(d, struct lws, dll_buflist);
pfd.events = LWS_POLLIN;
pfd.revents = LWS_POLLIN;
pfd.fd = -1;
lwsl_debug("%s: rxflow processing: %p fc=%d, 0x%lx\n", __func__,
wsi, lws_is_flowcontrolled(wsi),
(unsigned long)wsi->wsistate);
if (!lws_is_flowcontrolled(wsi) &&
lwsi_state(wsi) != LRS_DEFERRING_ACTION &&
(wsi->role_ops->handle_POLLIN)(pt, wsi, &pfd) ==
LWS_HPI_RET_PLEASE_CLOSE_ME)
lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS,
"close_and_handled");
} lws_end_foreach_dll_safe(d, d1);
lws_pt_unlock(pt);
}
/*
* guys that need POLLIN service again without waiting for network action
* can force POLLIN here if not flowcontrolled, so they will get service.
*
* Return nonzero if anybody got their POLLIN faked
*/
int
lws_service_flag_pending(struct lws_context *context, int tsi)
{
struct lws_context_per_thread *pt = &context->pt[tsi];
int forced = 0;
lws_pt_lock(pt, __func__);
/*
* 1) If there is any wsi with a buflist and in a state to process
* it, we should not wait in poll
*/
lws_start_foreach_dll(struct lws_dll2 *, d, pt->dll_buflist_owner.head) {
struct lws *wsi = lws_container_of(d, struct lws, dll_buflist);
if (!lws_is_flowcontrolled(wsi) &&
lwsi_state(wsi) != LRS_DEFERRING_ACTION) {
forced = 1;
break;
}
} lws_end_foreach_dll(d);
#if defined(LWS_ROLE_WS)
forced |= role_ops_ws.service_flag_pending(context, tsi);
#endif
#if defined(LWS_WITH_TLS)
/*
* 2) For all guys with buffered SSL read data already saved up, if they
* are not flowcontrolled, fake their POLLIN status so they'll get
* service to use up the buffered incoming data, even though their
* network socket may have nothing
*/
lws_start_foreach_dll_safe(struct lws_dll2 *, p, p1,
lws_dll2_get_head(&pt->tls.dll_pending_tls_owner)) {
struct lws *wsi = lws_container_of(p, struct lws,
tls.dll_pending_tls);
pt->fds[wsi->position_in_fds_table].revents |=
pt->fds[wsi->position_in_fds_table].events & LWS_POLLIN;
if (pt->fds[wsi->position_in_fds_table].revents & LWS_POLLIN) {
forced = 1;
/*
* he's going to get serviced now, take him off the
* list of guys with buffered SSL. If he still has some
* at the end of the service, he'll get put back on the
* list then.
*/
__lws_ssl_remove_wsi_from_buffered_list(wsi);
}
} lws_end_foreach_dll_safe(p, p1);
#endif
lws_pt_unlock(pt);
return forced;
}
LWS_VISIBLE int
lws_service_fd_tsi(struct lws_context *context, struct lws_pollfd *pollfd,
int tsi)
{
struct lws_context_per_thread *pt = &context->pt[tsi];
struct lws *wsi;
if (!context || context->being_destroyed1 )
return -1;
if (!pollfd) {
/*
* calling with NULL pollfd for periodic background processing
* is no longer needed and is now illegal.
*/
assert(pollfd);
return -1;
}
assert(lws_socket_is_valid(pollfd->fd));
/* no, here to service a socket descriptor */
wsi = wsi_from_fd(context, pollfd->fd);
if (!wsi)
/* not lws connection ... leave revents alone and return */
return 0;
#if LWS_MAX_SMP > 1
if (wsi->undergoing_init_from_other_pt)
/*
* Temporary situation that other service thread is initializing
* this wsi right now for use on our service thread.
*/
return 0;
#endif
/*
* so that caller can tell we handled, past here we need to
* zero down pollfd->revents after handling
*/
/* handle session socket closed */
if ((!(pollfd->revents & pollfd->events & LWS_POLLIN)) &&
(pollfd->revents & LWS_POLLHUP)) {
wsi->socket_is_permanently_unusable = 1;
lwsl_debug("Session Socket %p (fd=%d) dead\n",
(void *)wsi, pollfd->fd);
goto close_and_handled;
}
#ifdef _WIN32
if (pollfd->revents & LWS_POLLOUT)
wsi->sock_send_blocking = FALSE;
#endif
if ((!(pollfd->revents & pollfd->events & LWS_POLLIN)) &&
(pollfd->revents & LWS_POLLHUP)) {
lwsl_debug("pollhup\n");
wsi->socket_is_permanently_unusable = 1;
goto close_and_handled;
}
#if defined(LWS_WITH_TLS)
if (lwsi_state(wsi) == LRS_SHUTDOWN &&
lws_is_ssl(wsi) && wsi->tls.ssl) {
switch (__lws_tls_shutdown(wsi)) {
case LWS_SSL_CAPABLE_DONE:
case LWS_SSL_CAPABLE_ERROR:
goto close_and_handled;
case LWS_SSL_CAPABLE_MORE_SERVICE_READ:
case LWS_SSL_CAPABLE_MORE_SERVICE_WRITE:
case LWS_SSL_CAPABLE_MORE_SERVICE:
goto handled;
}
}
#endif
wsi->could_have_pending = 0; /* clear back-to-back write detection */
/* okay, what we came here to do... */
/* if we got here, we should have wire protocol ops set on the wsi */
assert(wsi->role_ops);
// lwsl_notice("%s: %s: wsistate 0x%x\n", __func__, wsi->role_ops->name,
// wsi->wsistate);
switch ((wsi->role_ops->handle_POLLIN)(pt, wsi, pollfd)) {
case LWS_HPI_RET_WSI_ALREADY_DIED:
return 1;
case LWS_HPI_RET_HANDLED:
break;
case LWS_HPI_RET_PLEASE_CLOSE_ME:
close_and_handled:
lwsl_debug("%p: Close and handled\n", wsi);
lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS,
"close_and_handled");
#if defined(_DEBUG) && defined(LWS_WITH_LIBUV)
/*
* confirm close has no problem being called again while
* it waits for libuv service to complete the first async
* close
*/
if (context->event_loop_ops == &event_loop_ops_uv)
lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS,
"close_and_handled uv repeat test");
#endif
/*
* pollfd may point to something else after the close
* due to pollfd swapping scheme on delete on some platforms
* we can't clear revents now because it'd be the wrong guy's
* revents
*/
return 1;
default:
assert(0);
}
#if defined(LWS_WITH_TLS)
handled:
#endif
pollfd->revents = 0;
if (!context->protocol_init_done)
if (lws_protocol_init(context)) {
lwsl_err("%s: lws_protocol_init failed\n", __func__);
return -1;
}
return 0;
}
LWS_VISIBLE int
lws_service_fd(struct lws_context *context, struct lws_pollfd *pollfd)
{
return lws_service_fd_tsi(context, pollfd, 0);
}
LWS_VISIBLE int
lws_service(struct lws_context *context, int timeout_ms)
{
struct lws_context_per_thread *pt = &context->pt[0];
int n;
if (!context)
return 1;
pt->inside_service = 1;
if (context->event_loop_ops->run_pt) {
/* we are configured for an event loop */
context->event_loop_ops->run_pt(context, 0);
pt->inside_service = 0;
return 1;
}
n = lws_plat_service(context, timeout_ms);
pt->inside_service = 0;
return n;
}
LWS_VISIBLE int
lws_service_tsi(struct lws_context *context, int timeout_ms, int tsi)
{
struct lws_context_per_thread *pt = &context->pt[tsi];
int n;
pt->inside_service = 1;
#if LWS_MAX_SMP > 1
pt->self = pthread_self();
#endif
if (context->event_loop_ops->run_pt) {
/* we are configured for an event loop */
context->event_loop_ops->run_pt(context, tsi);
pt->inside_service = 0;
return 1;
}
n = _lws_plat_service_tsi(context, timeout_ms, tsi);
pt->inside_service = 0;
return n;
}