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];
lws_sockfd_type our_fd = 0, tmp_fd;
struct lws_tokens eff_buf;
unsigned int pending = 0;
struct lws *wsi, *wsi1;
char draining_flow = 0;
int timed_out = 0;
time_t now;
int n, m;
int more;
/*
* you can call us with pollfd = NULL to just allow the once-per-second
* global timeout checks; if less than a second since the last check
* it returns immediately then.
*/
time(&now);
/* TODO: if using libev, we should probably use timeout watchers... */
if (context->last_timeout_check_s != now) {
context->last_timeout_check_s = now;
lws_plat_service_periodic(context);
/* global timeout check once per second */
if (pollfd)
our_fd = pollfd->fd;
wsi = context->pt[tsi].timeout_list;
while (wsi) {
/* we have to take copies, because he may be deleted */
wsi1 = wsi->timeout_list;
tmp_fd = wsi->sock;
if (lws_service_timeout_check(wsi, (unsigned int)now)) {
/* he did time out... */
if (tmp_fd == our_fd)
/* it was the guy we came to service! */
timed_out = 1;
/* he's gone, no need to mark as handled */
}
wsi = wsi1;
}
#if 0
{
char s[300], *p = s;
for (n = 0; n < context->count_threads; n++)
p += sprintf(p, " %7lu (%5d), ",
context->pt[n].count_conns,
context->pt[n].fds_count);
lwsl_notice("load: %s\n", s);
}
#endif
}
/* the socket we came to service timed out, nothing to do */
if (timed_out)
return 0;
/* just here for timeout management? */
if (!pollfd)
return 0;
/* 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;
/*
* so that caller can tell we handled, past here we need to
* zero down pollfd->revents after handling
*/
#if LWS_POSIX
/* 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
#endif
/* okay, what we came here to do... */
switch (wsi->mode) {
case LWSCM_HTTP_SERVING:
case LWSCM_HTTP_SERVING_ACCEPTED:
case LWSCM_SERVER_LISTENER:
case LWSCM_SSL_ACK_PENDING:
n = lws_server_socket_service(context, wsi, pollfd);
if (n) /* closed by above */
return 1;
pending = lws_ssl_pending(wsi);
if (pending)
goto handle_pending;
goto handled;
case LWSCM_WS_SERVING:
case LWSCM_WS_CLIENT:
case LWSCM_HTTP2_SERVING:
/* 1: something requested a callback when it was OK to write */
if ((pollfd->revents & LWS_POLLOUT) &&
(wsi->state == LWSS_ESTABLISHED ||
wsi->state == LWSS_HTTP2_ESTABLISHED ||
wsi->state == LWSS_HTTP2_ESTABLISHED_PRE_SETTINGS ||
wsi->state == LWSS_RETURNED_CLOSE_ALREADY ||
wsi->state == LWSS_FLUSHING_STORED_SEND_BEFORE_CLOSE) &&
lws_handle_POLLOUT_event(wsi, pollfd)) {
if (wsi->state == LWSS_RETURNED_CLOSE_ALREADY)
wsi->state = LWSS_FLUSHING_STORED_SEND_BEFORE_CLOSE;
lwsl_info("lws_service_fd: closing\n");
goto close_and_handled;
}
#if 1
if (wsi->state == LWSS_RETURNED_CLOSE_ALREADY ||
wsi->state == LWSS_AWAITING_CLOSE_ACK) {
/*
* we stopped caring about anything except control
* packets. Force flow control off, defeat tx
* draining.
*/
lws_rx_flow_control(wsi, 1);
wsi->u.ws.tx_draining_ext = 0;
}
#endif
if (wsi->u.ws.tx_draining_ext) {
/* we cannot deal with new RX until the TX ext
* path has been drained. It's because new
* rx will, eg, crap on the wsi rx buf that
* may be needed to retain state.
*
* TX ext drain path MUST go through event loop
* to avoid blocking.
*/
break;
}
if (!(wsi->rxflow_change_to & LWS_RXFLOW_ALLOW))
/* We cannot deal with any kind of new RX
* because we are RX-flowcontrolled.
*/
break;
/* 2: RX Extension needs to be drained
*/
if (wsi->state == LWSS_ESTABLISHED &&
wsi->u.ws.rx_draining_ext) {
lwsl_ext("%s: RX EXT DRAINING: Service\n", __func__);
#ifndef LWS_NO_CLIENT
if (wsi->mode == LWSCM_WS_CLIENT) {
n = lws_client_rx_sm(wsi, 0);
if (n < 0)
/* we closed wsi */
n = 0;
} else
#endif
n = lws_rx_sm(wsi, 0);
goto handled;
}
if (wsi->u.ws.rx_draining_ext)
/*
* We have RX EXT content to drain, but can't do it
* right now. That means we cannot do anything lower
* priority either.
*/
break;
/* 3: RX Flowcontrol buffer needs to be drained
*/
if (wsi->rxflow_buffer) {
lwsl_info("draining rxflow (len %d)\n",
wsi->rxflow_len - wsi->rxflow_pos
);
/* well, drain it */
eff_buf.token = (char *)wsi->rxflow_buffer +
wsi->rxflow_pos;
eff_buf.token_len = wsi->rxflow_len - wsi->rxflow_pos;
draining_flow = 1;
goto drain;
}
/* 4: any incoming data ready?
* notice if rx flow going off raced poll(), rx flow wins
*/
if (!(pollfd->revents & pollfd->events & LWS_POLLIN))
break;
read:
eff_buf.token_len = lws_ssl_capable_read(wsi, pt->serv_buf,
pending ? pending : LWS_MAX_SOCKET_IO_BUF);
switch (eff_buf.token_len) {
case 0:
lwsl_info("service_fd: closing due to 0 length read\n");
goto close_and_handled;
case LWS_SSL_CAPABLE_MORE_SERVICE:
lwsl_info("SSL Capable more service\n");
n = 0;
goto handled;
case LWS_SSL_CAPABLE_ERROR:
lwsl_info("Closing when error\n");
goto close_and_handled;
}
/*
* give any active extensions a chance to munge the buffer
* before parse. We pass in a pointer to an lws_tokens struct
* prepared with the default buffer and content length that's in
* there. Rather than rewrite the default buffer, extensions
* that expect to grow the buffer can adapt .token to
* point to their own per-connection buffer in the extension
* user allocation. By default with no extensions or no
* extension callback handling, just the normal input buffer is
* used then so it is efficient.
*/
eff_buf.token = (char *)pt->serv_buf;
drain:
do {
more = 0;
m = lws_ext_cb_active(wsi,
LWS_EXT_CB_PACKET_RX_PREPARSE, &eff_buf, 0);
if (m < 0)
goto close_and_handled;
if (m)
more = 1;
/* service incoming data */
if (eff_buf.token_len) {
/*
* if draining from rxflow buffer, not
* critical to track what was used since at the
* use it bumps wsi->rxflow_pos. If we come
* around again it will pick up from where it
* left off.
*/
n = lws_read(wsi, (unsigned char *)eff_buf.token,
eff_buf.token_len);
if (n < 0) {
/* we closed wsi */
n = 0;
goto handled;
}
}
eff_buf.token = NULL;
eff_buf.token_len = 0;
} while (more);
pending = lws_ssl_pending(wsi);
if (pending) {
handle_pending:
pending = pending > LWS_MAX_SOCKET_IO_BUF ?
LWS_MAX_SOCKET_IO_BUF : pending;
goto read;
}
if (draining_flow && wsi->rxflow_buffer &&
wsi->rxflow_pos == wsi->rxflow_len) {
lwsl_info("flow buffer: drained\n");
lws_free_set_NULL(wsi->rxflow_buffer);
/* having drained the rxflow buffer, can rearm POLLIN */
#ifdef LWS_NO_SERVER
n =
#endif
_lws_rx_flow_control(wsi);
/* n ignored, needed for NO_SERVER case */
}
break;
default:
#ifdef LWS_NO_CLIENT
break;
#else
n = lws_client_socket_service(context, wsi, pollfd);
if (n)
return 1;
goto handled;
#endif
}
n = 0;
goto handled;
close_and_handled:
lwsl_debug("Close and handled\n");
lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
/*
* 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;
handled:
pollfd->revents = 0;
return n;
}
LWS_VISIBLE int
libwebsocket_service_fd(struct libwebsocket_context *context,
struct libwebsocket_pollfd *pollfd)
{
struct libwebsocket *wsi;
int n;
int m;
int listen_socket_fds_index = 0;
time_t now;
int timed_out = 0;
int our_fd = 0;
char draining_flow = 0;
int more;
struct lws_tokens eff_buf;
int pending = 0;
if (context->listen_service_fd)
listen_socket_fds_index = wsi_from_fd(context,context->listen_service_fd)->position_in_fds_table;
/*
* you can call us with pollfd = NULL to just allow the once-per-second
* global timeout checks; if less than a second since the last check
* it returns immediately then.
*/
time(&now);
/* TODO: if using libev, we should probably use timeout watchers... */
if (context->last_timeout_check_s != now) {
context->last_timeout_check_s = now;
lws_plat_service_periodic(context);
/* global timeout check once per second */
if (pollfd)
our_fd = pollfd->fd;
for (n = 0; n < context->fds_count; n++) {
m = context->fds[n].fd;
wsi = wsi_from_fd(context,m);
if (!wsi)
continue;
if (libwebsocket_service_timeout_check(context, wsi, now))
/* he did time out... */
if (m == our_fd) {
/* it was the guy we came to service! */
timed_out = 1;
/* he's gone, no need to mark as handled */
}
}
}
/* the socket we came to service timed out, nothing to do */
if (timed_out)
return 0;
/* just here for timeout management? */
if (pollfd == NULL)
return 0;
/* no, here to service a socket descriptor */
wsi = wsi_from_fd(context,pollfd->fd);
if (wsi == NULL)
/* not lws connection ... leave revents alone and return */
return 0;
/*
* so that caller can tell we handled, past here we need to
* zero down pollfd->revents after handling
*/
/*
* deal with listen service piggybacking
* every listen_service_modulo services of other fds, we
* sneak one in to service the listen socket if there's anything waiting
*
* To handle connection storms, as found in ab, if we previously saw a
* pending connection here, it causes us to check again next time.
*/
if (context->listen_service_fd && pollfd !=
&context->fds[listen_socket_fds_index]) {
context->listen_service_count++;
if (context->listen_service_extraseen ||
context->listen_service_count ==
context->listen_service_modulo) {
context->listen_service_count = 0;
m = 1;
if (context->listen_service_extraseen > 5)
m = 2;
while (m--) {
/*
* even with extpoll, we prepared this
* internal fds for listen
*/
n = lws_poll_listen_fd(&context->fds[listen_socket_fds_index]);
if (n > 0) { /* there's a conn waiting for us */
libwebsocket_service_fd(context,
&context->
fds[listen_socket_fds_index]);
context->listen_service_extraseen++;
} else {
if (context->listen_service_extraseen)
context->
listen_service_extraseen--;
break;
}
}
}
}
/* handle session socket closed */
if ((!(pollfd->revents & LWS_POLLIN)) &&
(pollfd->revents & LWS_POLLHUP)) {
lwsl_debug("Session Socket %p (fd=%d) dead\n",
(void *)wsi, pollfd->fd);
goto close_and_handled;
}
/* okay, what we came here to do... */
switch (wsi->mode) {
case LWS_CONNMODE_HTTP_SERVING:
case LWS_CONNMODE_HTTP_SERVING_ACCEPTED:
case LWS_CONNMODE_SERVER_LISTENER:
case LWS_CONNMODE_SSL_ACK_PENDING:
n = lws_server_socket_service(context, wsi, pollfd);
if (n < 0)
goto close_and_handled;
goto handled;
case LWS_CONNMODE_WS_SERVING:
case LWS_CONNMODE_WS_CLIENT:
case LWS_CONNMODE_HTTP2_SERVING:
/* the guy requested a callback when it was OK to write */
if ((pollfd->revents & LWS_POLLOUT) &&
(wsi->state == WSI_STATE_ESTABLISHED ||
wsi->state == WSI_STATE_HTTP2_ESTABLISHED ||
wsi->state == WSI_STATE_HTTP2_ESTABLISHED_PRE_SETTINGS ||
wsi->state == WSI_STATE_RETURNED_CLOSE_ALREADY ||
wsi->state == WSI_STATE_FLUSHING_STORED_SEND_BEFORE_CLOSE) &&
lws_handle_POLLOUT_event(context, wsi, pollfd)) {
lwsl_info("libwebsocket_service_fd: closing\n");
goto close_and_handled;
}
if (wsi->rxflow_buffer &&
(wsi->rxflow_change_to & LWS_RXFLOW_ALLOW)) {
lwsl_info("draining rxflow\n");
/* well, drain it */
eff_buf.token = (char *)wsi->rxflow_buffer +
wsi->rxflow_pos;
eff_buf.token_len = wsi->rxflow_len - wsi->rxflow_pos;
draining_flow = 1;
goto drain;
}
/* any incoming data ready? */
if (!(pollfd->revents & LWS_POLLIN))
break;
read:
eff_buf.token_len = lws_ssl_capable_read(context, wsi,
context->service_buffer,
pending?pending:sizeof(context->service_buffer));
switch (eff_buf.token_len) {
case 0:
lwsl_info("service_fd: closing due to 0 length read\n");
goto close_and_handled;
case LWS_SSL_CAPABLE_MORE_SERVICE:
lwsl_info("SSL Capable more service\n");
n = 0;
goto handled;
case LWS_SSL_CAPABLE_ERROR:
lwsl_info("Closing when error\n");
goto close_and_handled;
}
/*
* give any active extensions a chance to munge the buffer
* before parse. We pass in a pointer to an lws_tokens struct
* prepared with the default buffer and content length that's in
* there. Rather than rewrite the default buffer, extensions
* that expect to grow the buffer can adapt .token to
* point to their own per-connection buffer in the extension
* user allocation. By default with no extensions or no
* extension callback handling, just the normal input buffer is
* used then so it is efficient.
*/
eff_buf.token = (char *)context->service_buffer;
drain:
do {
more = 0;
m = lws_ext_callback_for_each_active(wsi,
LWS_EXT_CALLBACK_PACKET_RX_PREPARSE, &eff_buf, 0);
if (m < 0)
goto close_and_handled;
if (m)
more = 1;
/* service incoming data */
if (eff_buf.token_len) {
n = libwebsocket_read(context, wsi,
(unsigned char *)eff_buf.token,
eff_buf.token_len);
if (n < 0) {
/* we closed wsi */
n = 0;
goto handled;
}
}
eff_buf.token = NULL;
eff_buf.token_len = 0;
} while (more);
pending = lws_ssl_pending(wsi);
if (pending) {
pending = pending > sizeof(context->service_buffer)?
sizeof(context->service_buffer):pending;
goto read;
}
if (draining_flow && wsi->rxflow_buffer &&
wsi->rxflow_pos == wsi->rxflow_len) {
lwsl_info("flow buffer: drained\n");
lws_free2(wsi->rxflow_buffer);
/* having drained the rxflow buffer, can rearm POLLIN */
#ifdef LWS_NO_SERVER
n =
#endif
_libwebsocket_rx_flow_control(wsi); /* n ignored, needed for NO_SERVER case */
}
break;
default:
#ifdef LWS_NO_CLIENT
break;
#else
n = lws_client_socket_service(context, wsi, pollfd);
goto handled;
#endif
}
n = 0;
goto handled;
close_and_handled:
lwsl_debug("Close and handled\n");
libwebsocket_close_and_free_session(context, wsi,
LWS_CLOSE_STATUS_NOSTATUS);
// pollfd points to something else after the close
return 1;
handled:
pollfd->revents = 0;
return n;
}
