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libwebsockets/lib/client-parser.c
Andy Green fc7c5e4539 reflect send completeness in lws_write return 
under load, writing packet sizes to the socket that are normally fine
can do partial writes, eg asking to write 4096 may only take 2800 of
it and return 2800 from the actual send.

Until now lws assumed that if it was safe to send, it could take any
size buffer, that's not the case under load.

This patch changes lws_write to return the amount actually taken...
that and the meaning of it becomes tricky when dealing with
compressed links, the amount taken and the amount sent differ.  Also
there is no way to recover at the moment from a protocol-encoded
frame only being partially accepted... however for http file send
content it can and does recover now.

Small frames don't have to take any care about it but large atomic
sends (> 2K) have been seen to fail under load.

Signed-off-by: Andy Green <andy.green@linaro.org>
2013-02-23 10:50:10 +08:00

422 lines
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/*
* libwebsockets - small server side websockets and web server implementation
*
* Copyright (C) 2010-2013 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 "private-libwebsockets.h"
int libwebsocket_client_rx_sm(struct libwebsocket *wsi, unsigned char c)
{
int callback_action = LWS_CALLBACK_CLIENT_RECEIVE;
int handled;
struct lws_tokens eff_buf;
#ifndef LWS_NO_EXTENSIONS
int n;
int m;
#endif
switch (wsi->lws_rx_parse_state) {
case LWS_RXPS_NEW:
switch (wsi->ietf_spec_revision) {
case 13:
wsi->u.ws.opcode = c & 0xf;
wsi->u.ws.rsv = (c & 0x70);
wsi->u.ws.final = !!((c >> 7) & 1);
switch (wsi->u.ws.opcode) {
case LWS_WS_OPCODE_07__TEXT_FRAME:
case LWS_WS_OPCODE_07__BINARY_FRAME:
wsi->u.ws.frame_is_binary = wsi->u.ws.opcode ==
LWS_WS_OPCODE_07__BINARY_FRAME;
break;
}
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN;
break;
default:
lwsl_err("unknown spec version %02d\n",
wsi->ietf_spec_revision);
break;
}
break;
case LWS_RXPS_04_FRAME_HDR_LEN:
wsi->u.ws.this_frame_masked = !!(c & 0x80);
switch (c & 0x7f) {
case 126:
/* control frames are not allowed to have big lengths */
if (wsi->u.ws.opcode & 8)
goto illegal_ctl_length;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN16_2;
break;
case 127:
/* control frames are not allowed to have big lengths */
if (wsi->u.ws.opcode & 8)
goto illegal_ctl_length;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_8;
break;
default:
wsi->u.ws.rx_packet_length = c;
if (wsi->u.ws.this_frame_masked)
wsi->lws_rx_parse_state =
LWS_RXPS_07_COLLECT_FRAME_KEY_1;
else {
if (c)
wsi->lws_rx_parse_state =
LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
else {
wsi->lws_rx_parse_state = LWS_RXPS_NEW;
goto spill;
}
}
break;
}
break;
case LWS_RXPS_04_FRAME_HDR_LEN16_2:
wsi->u.ws.rx_packet_length = c << 8;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN16_1;
break;
case LWS_RXPS_04_FRAME_HDR_LEN16_1:
wsi->u.ws.rx_packet_length |= c;
if (wsi->u.ws.this_frame_masked)
wsi->lws_rx_parse_state =
LWS_RXPS_07_COLLECT_FRAME_KEY_1;
else {
if (wsi->u.ws.rx_packet_length)
wsi->lws_rx_parse_state =
LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
else {
wsi->lws_rx_parse_state = LWS_RXPS_NEW;
goto spill;
}
}
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_8:
if (c & 0x80) {
lwsl_warn("b63 of length must be zero\n");
/* kill the connection */
return -1;
}
#if defined __LP64__
wsi->u.ws.rx_packet_length = ((size_t)c) << 56;
#else
wsi->u.ws.rx_packet_length = 0;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_7;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_7:
#if defined __LP64__
wsi->u.ws.rx_packet_length |= ((size_t)c) << 48;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_6;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_6:
#if defined __LP64__
wsi->u.ws.rx_packet_length |= ((size_t)c) << 40;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_5;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_5:
#if defined __LP64__
wsi->u.ws.rx_packet_length |= ((size_t)c) << 32;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_4;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_4:
wsi->u.ws.rx_packet_length |= ((size_t)c) << 24;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_3;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_3:
wsi->u.ws.rx_packet_length |= ((size_t)c) << 16;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_2;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_2:
wsi->u.ws.rx_packet_length |= ((size_t)c) << 8;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_1;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_1:
wsi->u.ws.rx_packet_length |= (size_t)c;
if (wsi->u.ws.this_frame_masked)
wsi->lws_rx_parse_state =
LWS_RXPS_07_COLLECT_FRAME_KEY_1;
else {
if (wsi->u.ws.rx_packet_length)
wsi->lws_rx_parse_state =
LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
else {
wsi->lws_rx_parse_state = LWS_RXPS_NEW;
goto spill;
}
}
break;
case LWS_RXPS_07_COLLECT_FRAME_KEY_1:
wsi->u.ws.frame_masking_nonce_04[0] = c;
if (c)
wsi->u.ws.all_zero_nonce = 0;
wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_2;
break;
case LWS_RXPS_07_COLLECT_FRAME_KEY_2:
wsi->u.ws.frame_masking_nonce_04[1] = c;
if (c)
wsi->u.ws.all_zero_nonce = 0;
wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_3;
break;
case LWS_RXPS_07_COLLECT_FRAME_KEY_3:
wsi->u.ws.frame_masking_nonce_04[2] = c;
if (c)
wsi->u.ws.all_zero_nonce = 0;
wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_4;
break;
case LWS_RXPS_07_COLLECT_FRAME_KEY_4:
wsi->u.ws.frame_masking_nonce_04[3] = c;
if (c)
wsi->u.ws.all_zero_nonce = 0;
if (wsi->u.ws.rx_packet_length)
wsi->lws_rx_parse_state =
LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
else {
wsi->lws_rx_parse_state = LWS_RXPS_NEW;
goto spill;
}
break;
case LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED:
if (!wsi->u.ws.rx_user_buffer)
lwsl_err("NULL client rx_user_buffer\n");
if ((!wsi->u.ws.this_frame_masked) || wsi->u.ws.all_zero_nonce)
wsi->u.ws.rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING +
(wsi->u.ws.rx_user_buffer_head++)] = c;
else
wsi->u.ws.rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING +
(wsi->u.ws.rx_user_buffer_head++)] =
c ^ wsi->u.ws.frame_masking_nonce_04[
(wsi->u.ws.frame_mask_index++) & 3];
if (--wsi->u.ws.rx_packet_length == 0) {
/* spill because we have the whole frame */
wsi->lws_rx_parse_state = LWS_RXPS_NEW;
goto spill;
}
/*
* if there's no protocol max frame size given, we are
* supposed to default to LWS_MAX_SOCKET_IO_BUF
*/
if (!wsi->protocol->rx_buffer_size &&
wsi->u.ws.rx_user_buffer_head !=
LWS_MAX_SOCKET_IO_BUF)
break;
else
if (wsi->protocol->rx_buffer_size &&
wsi->u.ws.rx_user_buffer_head !=
wsi->protocol->rx_buffer_size)
break;
/* spill because we filled our rx buffer */
spill:
handled = 0;
/*
* is this frame a control packet we should take care of at this
* layer? If so service it and hide it from the user callback
*/
switch (wsi->u.ws.opcode) {
case LWS_WS_OPCODE_07__CLOSE:
/* is this an acknowledgement of our close? */
if (wsi->state == WSI_STATE_AWAITING_CLOSE_ACK) {
/*
* fine he has told us he is closing too, let's
* finish our close
*/
lwsl_parser("seen server's close ack\n");
return -1;
}
lwsl_parser("client sees server close len = %d\n",
wsi->u.ws.rx_user_buffer_head);
/*
* parrot the close packet payload back
* we do not care about how it went, we are closing
* immediately afterwards
*/
libwebsocket_write(wsi, (unsigned char *)
&wsi->u.ws.rx_user_buffer[
LWS_SEND_BUFFER_PRE_PADDING],
wsi->u.ws.rx_user_buffer_head, LWS_WRITE_CLOSE);
wsi->state = WSI_STATE_RETURNED_CLOSE_ALREADY;
/* close the connection */
return -1;
case LWS_WS_OPCODE_07__PING:
lwsl_info("client received ping, doing pong\n");
/*
* parrot the ping packet payload back as a pong
* !!! this may block or have partial write or fail
* !!! very unlikely if the ping size is small
*/
libwebsocket_write(wsi, (unsigned char *)
&wsi->u.ws.rx_user_buffer[
LWS_SEND_BUFFER_PRE_PADDING],
wsi->u.ws.rx_user_buffer_head,
LWS_WRITE_PONG);
handled = 1;
break;
case LWS_WS_OPCODE_07__PONG:
lwsl_info("client receied pong\n");
lwsl_hexdump(&wsi->u.ws.rx_user_buffer[
LWS_SEND_BUFFER_PRE_PADDING],
wsi->u.ws.rx_user_buffer_head);
/* issue it */
callback_action = LWS_CALLBACK_CLIENT_RECEIVE_PONG;
break;
case LWS_WS_OPCODE_07__CONTINUATION:
case LWS_WS_OPCODE_07__TEXT_FRAME:
case LWS_WS_OPCODE_07__BINARY_FRAME:
break;
default:
lwsl_parser("Reserved opc 0x%2X\n", wsi->u.ws.opcode);
#ifndef LWS_NO_EXTENSIONS
/*
* It's something special we can't understand here.
* Pass the payload up to the extension's parsing
* state machine.
*/
eff_buf.token = &wsi->u.ws.rx_user_buffer[
LWS_SEND_BUFFER_PRE_PADDING];
eff_buf.token_len = wsi->u.ws.rx_user_buffer_head;
for (n = 0; n < wsi->count_active_extensions; n++) {
m = wsi->active_extensions[n]->callback(
wsi->protocol->owning_server,
wsi->active_extensions[n], wsi,
LWS_EXT_CALLBACK_EXTENDED_PAYLOAD_RX,
wsi->active_extensions_user[n],
&eff_buf, 0);
if (m)
handled = 1;
}
if (!handled) {
#else
{
#endif
lwsl_ext("Unhandled ext opc 0x%x\n",
wsi->u.ws.opcode);
wsi->u.ws.rx_user_buffer_head = 0;
return 0;
}
break;
}
/*
* No it's real payload, pass it up to the user callback.
* It's nicely buffered with the pre-padding taken care of
* so it can be sent straight out again using libwebsocket_write
*/
if (handled)
goto already_done;
eff_buf.token = &wsi->u.ws.rx_user_buffer[
LWS_SEND_BUFFER_PRE_PADDING];
eff_buf.token_len = wsi->u.ws.rx_user_buffer_head;
#ifndef LWS_NO_EXTENSIONS
for (n = 0; n < wsi->count_active_extensions; n++) {
m = wsi->active_extensions[n]->callback(
wsi->protocol->owning_server,
wsi->active_extensions[n], wsi,
LWS_EXT_CALLBACK_PAYLOAD_RX,
wsi->active_extensions_user[n],
&eff_buf, 0);
if (m < 0) {
lwsl_ext(
"Ext '%s' failed to handle payload!\n",
wsi->active_extensions[n]->name);
return -1;
}
}
#endif
if (eff_buf.token_len <= 0)
goto already_done;
eff_buf.token[eff_buf.token_len] = '\0';
if (!wsi->protocol->callback)
goto already_done;
if (callback_action == LWS_CALLBACK_CLIENT_RECEIVE_PONG)
lwsl_info("Client doing pong callback\n");
wsi->protocol->callback(
wsi->protocol->owning_server,
wsi,
(enum libwebsocket_callback_reasons)callback_action,
wsi->user_space,
eff_buf.token,
eff_buf.token_len);
already_done:
wsi->u.ws.rx_user_buffer_head = 0;
break;
default:
lwsl_err("client rx illegal state\n");
return 1;
}
return 0;
illegal_ctl_length:
lwsl_warn("Control frame asking for extended length is illegal\n");
/* kill the connection */
return -1;
}
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