You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

657 lines
17 KiB

/*
* libwebsockets - small server side websockets and web server implementation
*
* Copyright (C) 2010 - 2020 Andy Green <andy@warmcat.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#include "private-lib-core.h"
int
_lws_change_pollfd(struct lws *wsi, int _and, int _or, struct lws_pollargs *pa)
{
#if !defined(LWS_WITH_LIBUV) && !defined(LWS_WITH_LIBEV) && \
!defined(LWS_WITH_LIBEVENT) && !defined(LWS_WITH_GLIB)
volatile struct lws_context_per_thread *vpt;
#endif
struct lws_context_per_thread *pt;
struct lws_context *context;
int ret = 0, pa_events;
struct lws_pollfd *pfd;
int sampled_tid, tid;
if (!wsi)
return 0;
assert(wsi->position_in_fds_table == LWS_NO_FDS_POS ||
wsi->position_in_fds_table >= 0);
if (wsi->position_in_fds_table == LWS_NO_FDS_POS)
return 0;
if (((volatile struct lws *)wsi)->handling_pollout &&
!_and && _or == LWS_POLLOUT) {
/*
* Happening alongside service thread handling POLLOUT.
* The danger is when he is finished, he will disable POLLOUT,
* countermanding what we changed here.
*
* Instead of changing the fds, inform the service thread
* what happened, and ask it to leave POLLOUT active on exit
*/
((volatile struct lws *)wsi)->leave_pollout_active = 1;
/*
* by definition service thread is not in poll wait, so no need
* to cancel service
*/
lwsl_debug("%s: using leave_pollout_active\n", __func__);
return 0;
}
context = wsi->context;
pt = &context->pt[(int)wsi->tsi];
assert(wsi->position_in_fds_table < (int)pt->fds_count);
#if !defined(LWS_WITH_LIBUV) && !defined(LWS_WITH_LIBEV) && \
!defined(LWS_WITH_LIBEVENT) && !defined(LWS_WITH_GLIB)
/*
* This only applies when we use the default poll() event loop.
*
* BSD can revert pa->events at any time, when the kernel decides to
* exit from poll(). We can't protect against it using locking.
*
* Therefore we must check first if the service thread is in poll()
* wait; if so, we know we must be being called from a foreign thread,
* and we must keep a strictly ordered list of changes we made instead
* of trying to apply them, since when poll() exits, which may happen
* at any time it would revert our changes.
*
* The plat code will apply them when it leaves the poll() wait
* before doing anything else.
*/
vpt = (volatile struct lws_context_per_thread *)pt;
vpt->foreign_spinlock = 1;
lws_memory_barrier();
if (vpt->inside_poll) {
struct lws_foreign_thread_pollfd *ftp, **ftp1;
/*
* We are certainly a foreign thread trying to change events
* while the service thread is in the poll() wait.
*
* Create a list of changes to be applied after poll() exit,
* instead of trying to apply them now.
*/
ftp = lws_malloc(sizeof(*ftp), "ftp");
if (!ftp) {
vpt->foreign_spinlock = 0;
lws_memory_barrier();
ret = -1;
goto bail;
}
ftp->_and = _and;
ftp->_or = _or;
ftp->fd_index = wsi->position_in_fds_table;
ftp->next = NULL;
lws_pt_lock(pt, __func__);
/* place at END of list to maintain order */
ftp1 = (struct lws_foreign_thread_pollfd **)
&vpt->foreign_pfd_list;
while (*ftp1)
ftp1 = &((*ftp1)->next);
*ftp1 = ftp;
vpt->foreign_spinlock = 0;
lws_memory_barrier();
lws_pt_unlock(pt);
lws_cancel_service_pt(wsi);
return 0;
}
vpt->foreign_spinlock = 0;
lws_memory_barrier();
#endif
#if !defined(__linux__)
/* OSX couldn't see close on stdin pipe side otherwise */
_or |= LWS_POLLHUP;
#endif
pfd = &pt->fds[wsi->position_in_fds_table];
pa->fd = wsi->desc.sockfd;
lwsl_debug("%s: wsi %p: fd %d events %d -> %d\n", __func__, wsi,
pa->fd, pfd->events, (pfd->events & ~_and) | _or);
pa->prev_events = pfd->events;
pa->events = pfd->events = (pfd->events & ~_and) | _or;
if (wsi->mux_substream)
return 0;
#if defined(LWS_WITH_EXTERNAL_POLL)
if (wsi->vhost &&
wsi->vhost->protocols[0].callback(wsi,
LWS_CALLBACK_CHANGE_MODE_POLL_FD,
wsi->user_space, (void *)pa, 0)) {
ret = -1;
goto bail;
}
#endif
if (context->event_loop_ops->io) {
if (_and & LWS_POLLIN)
context->event_loop_ops->io(wsi,
LWS_EV_STOP | LWS_EV_READ);
if (_or & LWS_POLLIN)
context->event_loop_ops->io(wsi,
LWS_EV_START | LWS_EV_READ);
if (_and & LWS_POLLOUT)
context->event_loop_ops->io(wsi,
LWS_EV_STOP | LWS_EV_WRITE);
if (_or & LWS_POLLOUT)
context->event_loop_ops->io(wsi,
LWS_EV_START | LWS_EV_WRITE);
}
/*
* if we changed something in this pollfd...
* ... and we're running in a different thread context
* than the service thread...
* ... and the service thread is waiting ...
* then cancel it to force a restart with our changed events
*/
pa_events = pa->prev_events != pa->events;
if (pa_events) {
if (lws_plat_change_pollfd(context, wsi, pfd)) {
lwsl_info("%s failed\n", __func__);
ret = -1;
goto bail;
}
sampled_tid = pt->service_tid;
if (sampled_tid && wsi->vhost) {
tid = wsi->vhost->protocols[0].callback(wsi,
LWS_CALLBACK_GET_THREAD_ID, NULL, NULL, 0);
if (tid == -1) {
ret = -1;
goto bail;
}
if (tid != sampled_tid)
lws_cancel_service_pt(wsi);
}
}
bail:
return ret;
}
#if defined(LWS_WITH_SERVER)
/*
* Enable or disable listen sockets on this pt globally...
* it's modulated according to the pt having space for a new accept.
*/
static void
lws_accept_modulation(struct lws_context *context,
struct lws_context_per_thread *pt, int allow)
{
struct lws_vhost *vh = context->vhost_list;
struct lws_pollargs pa1;
while (vh) {
if (vh->lserv_wsi) {
if (allow)
_lws_change_pollfd(vh->lserv_wsi,
0, LWS_POLLIN, &pa1);
else
_lws_change_pollfd(vh->lserv_wsi,
LWS_POLLIN, 0, &pa1);
}
vh = vh->vhost_next;
}
}
#endif
#if defined(_DEBUG)
void
__dump_fds(struct lws_context_per_thread *pt, const char *s)
{
unsigned int n;
lwsl_warn("%s: fds_count %u, %s\n", __func__, pt->fds_count, s);
for (n = 0; n < pt->fds_count; n++) {
struct lws *wsi = wsi_from_fd(pt->context, pt->fds[n].fd);
lwsl_warn(" %d: fd %d, wsi %p, pos_in_fds: %d\n",
n + 1, pt->fds[n].fd, wsi,
wsi ? wsi->position_in_fds_table : -1);
}
}
#else
#define __dump_fds(x, y)
#endif
int
__insert_wsi_socket_into_fds(struct lws_context *context, struct lws *wsi)
{
#if defined(LWS_WITH_EXTERNAL_POLL)
struct lws_pollargs pa = { wsi->desc.sockfd, LWS_POLLIN, 0 };
#endif
struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
int ret = 0;
// __dump_fds(pt, "pre insert");
lwsl_debug("%s: %p: tsi=%d, sock=%d, pos-in-fds=%d\n",
__func__, wsi, wsi->tsi, wsi->desc.sockfd, pt->fds_count);
if ((unsigned int)pt->fds_count >= context->fd_limit_per_thread) {
lwsl_err("Too many fds (%d vs %d)\n", context->max_fds,
context->fd_limit_per_thread );
return 1;
}
#if !defined(_WIN32)
if (!wsi->context->max_fds_unrelated_to_ulimit &&
wsi->desc.sockfd - lws_plat_socket_offset() >= context->max_fds) {
lwsl_err("Socket fd %d is too high (%d) offset %d\n",
wsi->desc.sockfd, context->max_fds,
lws_plat_socket_offset());
return 1;
}
#endif
assert(wsi);
assert(wsi->event_pipe || wsi->vhost);
assert(lws_socket_is_valid(wsi->desc.sockfd));
#if defined(LWS_WITH_EXTERNAL_POLL)
if (wsi->vhost &&
wsi->vhost->protocols[0].callback(wsi, LWS_CALLBACK_LOCK_POLL,
wsi->user_space, (void *) &pa, 1))
return -1;
#endif
if (insert_wsi(context, wsi))
return -1;
pt->count_conns++;
wsi->position_in_fds_table = pt->fds_count;
pt->fds[wsi->position_in_fds_table].fd = wsi->desc.sockfd;
pt->fds[wsi->position_in_fds_table].events = LWS_POLLIN;
#if defined(LWS_WITH_EXTERNAL_POLL)
pa.events = pt->fds[pt->fds_count].events;
#endif
lws_plat_insert_socket_into_fds(context, wsi);
#if defined(LWS_WITH_EXTERNAL_POLL)
/* external POLL support via protocol 0 */
if (wsi->vhost &&
wsi->vhost->protocols[0].callback(wsi, LWS_CALLBACK_ADD_POLL_FD,
wsi->user_space, (void *) &pa, 0))
ret = -1;
#endif
#if defined(LWS_WITH_SERVER)
/* if no more room, defeat accepts on this service thread */
if ((unsigned int)pt->fds_count == context->fd_limit_per_thread - 1)
lws_accept_modulation(context, pt, 0);
#endif
#if defined(LWS_WITH_EXTERNAL_POLL)
if (wsi->vhost &&
wsi->vhost->protocols[0].callback(wsi, LWS_CALLBACK_UNLOCK_POLL,
wsi->user_space, (void *)&pa, 1))
ret = -1;
#endif
// __dump_fds(pt, "post insert");
return ret;
}
int
__remove_wsi_socket_from_fds(struct lws *wsi)
{
struct lws_context *context = wsi->context;
#if defined(LWS_WITH_EXTERNAL_POLL)
struct lws_pollargs pa = { wsi->desc.sockfd, 0, 0 };
#endif
struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
struct lws *end_wsi;
int v, m, ret = 0;
// __dump_fds(pt, "pre remove");
#if !defined(_WIN32)
if (!wsi->context->max_fds_unrelated_to_ulimit &&
wsi->desc.sockfd - lws_plat_socket_offset() > context->max_fds) {
lwsl_err("fd %d too high (%d)\n", wsi->desc.sockfd,
context->max_fds);
return 1;
}
#endif
#if defined(LWS_WITH_EXTERNAL_POLL)
if (wsi->vhost && wsi->vhost->protocols &&
wsi->vhost->protocols[0].callback(wsi, LWS_CALLBACK_LOCK_POLL,
wsi->user_space, (void *)&pa, 1))
return -1;
#endif
lws_same_vh_protocol_remove(wsi);
/* the guy who is to be deleted's slot index in pt->fds */
m = wsi->position_in_fds_table;
/* these are the only valid possibilities for position_in_fds_table */
assert(m == LWS_NO_FDS_POS || (m >= 0 &&
(unsigned int)m < pt->fds_count));
if (context->event_loop_ops->io)
context->event_loop_ops->io(wsi,
LWS_EV_STOP | LWS_EV_READ | LWS_EV_WRITE |
LWS_EV_PREPARE_DELETION);
/*
lwsl_notice("%s: wsi=%p, skt=%d, fds pos=%d, end guy pos=%d, endfd=%d\n",
__func__, wsi, wsi->desc.sockfd, wsi->position_in_fds_table,
pt->fds_count, pt->fds[pt->fds_count - 1].fd); */
if (m != LWS_NO_FDS_POS) {
char fixup = 0;
assert(pt->fds_count && (unsigned int)m != pt->fds_count);
/* deletion guy's lws_lookup entry needs nuking */
delete_from_fd(context, wsi->desc.sockfd);
if ((unsigned int)m != pt->fds_count - 1) {
/* have the last guy take up the now vacant slot */
pt->fds[m] = pt->fds[pt->fds_count - 1];
fixup = 1;
}
pt->fds[pt->fds_count - 1].fd = -1;
/* this decrements pt->fds_count */
lws_plat_delete_socket_from_fds(context, wsi, m);
pt->count_conns--;
if (fixup) {
v = (int) pt->fds[m].fd;
/* old end guy's "position in fds table" is now the
* deletion guy's old one */
end_wsi = wsi_from_fd(context, v);
if (!end_wsi) {
lwsl_err("no wsi for fd %d pos %d, "
"pt->fds_count=%d\n",
(int)pt->fds[m].fd, m, pt->fds_count);
assert(0);
} else
end_wsi->position_in_fds_table = m;
}
/* removed wsi has no position any more */
wsi->position_in_fds_table = LWS_NO_FDS_POS;
}
#if defined(LWS_WITH_EXTERNAL_POLL)
/* remove also from external POLL support via protocol 0 */
if (lws_socket_is_valid(wsi->desc.sockfd) && wsi->vhost &&
wsi->vhost->protocols[0].callback(wsi, LWS_CALLBACK_DEL_POLL_FD,
wsi->user_space, (void *) &pa, 0))
ret = -1;
#endif
#if defined(LWS_WITH_SERVER)
if (!context->being_destroyed &&
/* if this made some room, accept connects on this thread */
(unsigned int)pt->fds_count < context->fd_limit_per_thread - 1)
lws_accept_modulation(context, pt, 1);
#endif
#if defined(LWS_WITH_EXTERNAL_POLL)
if (wsi->vhost &&
wsi->vhost->protocols[0].callback(wsi, LWS_CALLBACK_UNLOCK_POLL,
wsi->user_space, (void *) &pa, 1))
ret = -1;
#endif
// __dump_fds(pt, "post remove");
return ret;
}
int
__lws_change_pollfd(struct lws *wsi, int _and, int _or)
{
struct lws_context *context;
struct lws_pollargs pa;
int ret = 0;
if (!wsi || (!wsi->protocol && !wsi->event_pipe) ||
wsi->position_in_fds_table == LWS_NO_FDS_POS)
return 0;
context = lws_get_context(wsi);
if (!context)
return 1;
#if defined(LWS_WITH_EXTERNAL_POLL)
if (wsi->vhost &&
wsi->vhost->protocols[0].callback(wsi, LWS_CALLBACK_LOCK_POLL,
wsi->user_space, (void *) &pa, 0))
return -1;
#endif
ret = _lws_change_pollfd(wsi, _and, _or, &pa);
#if defined(LWS_WITH_EXTERNAL_POLL)
if (wsi->vhost &&
wsi->vhost->protocols[0].callback(wsi, LWS_CALLBACK_UNLOCK_POLL,
wsi->user_space, (void *) &pa, 0))
ret = -1;
#endif
return ret;
}
int
lws_change_pollfd(struct lws *wsi, int _and, int _or)
{
struct lws_context_per_thread *pt;
int ret = 0;
pt = &wsi->context->pt[(int)wsi->tsi];
lws_pt_lock(pt, __func__);
ret = __lws_change_pollfd(wsi, _and, _or);
lws_pt_unlock(pt);
return ret;
}
int
lws_callback_on_writable(struct lws *wsi)
{
struct lws_context_per_thread *pt;
struct lws *w = wsi;
if (lwsi_state(wsi) == LRS_SHUTDOWN)
return 0;
if (wsi->socket_is_permanently_unusable)
return 0;
pt = &wsi->context->pt[(int)wsi->tsi];
#if defined(LWS_WITH_DETAILED_LATENCY)
if (!wsi->detlat.earliest_write_req)
wsi->detlat.earliest_write_req = lws_now_usecs();
#endif
lws_stats_bump(pt, LWSSTATS_C_WRITEABLE_CB_REQ, 1);
#if defined(LWS_WITH_STATS)
if (!wsi->active_writable_req_us) {
wsi->active_writable_req_us = lws_now_usecs();
lws_stats_bump(pt, LWSSTATS_C_WRITEABLE_CB_EFF_REQ, 1);
}
#endif
if (wsi->role_ops->callback_on_writable) {
int q = wsi->role_ops->callback_on_writable(wsi);
//lwsl_notice("%s: rops_cow says %d\n", __func__, q);
if (q)
return 1;
w = lws_get_network_wsi(wsi);
} else
if (w->position_in_fds_table == LWS_NO_FDS_POS) {
lwsl_debug("%s: failed to find socket %d\n", __func__,
wsi->desc.sockfd);
return -1;
}
//lwsl_notice("%s: marking for POLLOUT %p (wsi %p)\n", __func__, w, wsi);
if (__lws_change_pollfd(w, 0, LWS_POLLOUT))
return -1;
return 1;
}
/*
* stitch protocol choice into the vh protocol linked list
* We always insert ourselves at the start of the list
*
* X <-> B
* X <-> pAn <-> pB
*
* Illegal to attach more than once without detach inbetween
*/
void
lws_same_vh_protocol_insert(struct lws *wsi, int n)
{
lws_vhost_lock(wsi->vhost);
lws_dll2_remove(&wsi->same_vh_protocol);
lws_dll2_add_head(&wsi->same_vh_protocol,
&wsi->vhost->same_vh_protocol_owner[n]);
wsi->bound_vhost_index = n;
lws_vhost_unlock(wsi->vhost);
}
void
__lws_same_vh_protocol_remove(struct lws *wsi)
{
if (wsi->vhost && wsi->vhost->same_vh_protocol_owner)
lws_dll2_remove(&wsi->same_vh_protocol);
}
void
lws_same_vh_protocol_remove(struct lws *wsi)
{
if (!wsi->vhost)
return;
lws_vhost_lock(wsi->vhost);
__lws_same_vh_protocol_remove(wsi);
lws_vhost_unlock(wsi->vhost);
}
int
lws_callback_on_writable_all_protocol_vhost(const struct lws_vhost *vhost,
const struct lws_protocols *protocol)
{
struct lws *wsi;
int n;
if (protocol < vhost->protocols ||
protocol >= (vhost->protocols + vhost->count_protocols)) {
lwsl_err("%s: protocol %p is not from vhost %p (%p - %p)\n",
__func__, protocol, vhost->protocols, vhost,
(vhost->protocols + vhost->count_protocols));
return -1;
}
n = (int)(protocol - vhost->protocols);
lws_start_foreach_dll_safe(struct lws_dll2 *, d, d1,
lws_dll2_get_head(&vhost->same_vh_protocol_owner[n])) {
wsi = lws_container_of(d, struct lws, same_vh_protocol);
assert(wsi->protocol == protocol);
lws_callback_on_writable(wsi);
} lws_end_foreach_dll_safe(d, d1);
return 0;
}
int
lws_callback_on_writable_all_protocol(const struct lws_context *context,
const struct lws_protocols *protocol)
{
struct lws_vhost *vhost;
int n;
if (!context)
return 0;
vhost = context->vhost_list;
while (vhost) {
for (n = 0; n < vhost->count_protocols; n++)
if (protocol->callback ==
vhost->protocols[n].callback &&
!strcmp(protocol->name, vhost->protocols[n].name))
break;
if (n != vhost->count_protocols)
lws_callback_on_writable_all_protocol_vhost(
vhost, &vhost->protocols[n]);
vhost = vhost->vhost_next;
}
return 0;
}