403 lines
10 KiB
C
403 lines
10 KiB
C
/*
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* libwebsockets - small server side websockets and web server implementation
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*
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* Copyright (C) 2010-2014 Andy Green <andy@warmcat.com>
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation:
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* version 2.1 of the License.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
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* MA 02110-1301 USA
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*/
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#include "private-libwebsockets.h"
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int libwebsocket_client_rx_sm(struct libwebsocket *wsi, unsigned char c)
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{
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int callback_action = LWS_CALLBACK_CLIENT_RECEIVE;
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int handled;
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struct lws_tokens eff_buf;
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int m;
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switch (wsi->lws_rx_parse_state) {
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case LWS_RXPS_NEW:
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switch (wsi->ietf_spec_revision) {
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case 13:
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wsi->u.ws.opcode = c & 0xf;
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wsi->u.ws.rsv = (c & 0x70);
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wsi->u.ws.final = !!((c >> 7) & 1);
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switch (wsi->u.ws.opcode) {
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case LWS_WS_OPCODE_07__TEXT_FRAME:
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case LWS_WS_OPCODE_07__BINARY_FRAME:
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wsi->u.ws.frame_is_binary = wsi->u.ws.opcode ==
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LWS_WS_OPCODE_07__BINARY_FRAME;
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break;
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}
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wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN;
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break;
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default:
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lwsl_err("unknown spec version %02d\n",
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wsi->ietf_spec_revision);
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break;
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}
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break;
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case LWS_RXPS_04_FRAME_HDR_LEN:
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wsi->u.ws.this_frame_masked = !!(c & 0x80);
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switch (c & 0x7f) {
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case 126:
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/* control frames are not allowed to have big lengths */
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if (wsi->u.ws.opcode & 8)
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goto illegal_ctl_length;
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wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN16_2;
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break;
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case 127:
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/* control frames are not allowed to have big lengths */
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if (wsi->u.ws.opcode & 8)
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goto illegal_ctl_length;
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wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_8;
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break;
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default:
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wsi->u.ws.rx_packet_length = c;
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if (wsi->u.ws.this_frame_masked)
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wsi->lws_rx_parse_state =
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LWS_RXPS_07_COLLECT_FRAME_KEY_1;
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else {
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if (c)
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wsi->lws_rx_parse_state =
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LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
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else {
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wsi->lws_rx_parse_state = LWS_RXPS_NEW;
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goto spill;
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}
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}
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break;
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}
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break;
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case LWS_RXPS_04_FRAME_HDR_LEN16_2:
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wsi->u.ws.rx_packet_length = c << 8;
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wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN16_1;
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break;
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case LWS_RXPS_04_FRAME_HDR_LEN16_1:
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wsi->u.ws.rx_packet_length |= c;
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if (wsi->u.ws.this_frame_masked)
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wsi->lws_rx_parse_state =
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LWS_RXPS_07_COLLECT_FRAME_KEY_1;
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else {
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if (wsi->u.ws.rx_packet_length)
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wsi->lws_rx_parse_state =
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LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
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else {
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wsi->lws_rx_parse_state = LWS_RXPS_NEW;
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goto spill;
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}
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}
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break;
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case LWS_RXPS_04_FRAME_HDR_LEN64_8:
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if (c & 0x80) {
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lwsl_warn("b63 of length must be zero\n");
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/* kill the connection */
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return -1;
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}
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#if defined __LP64__
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wsi->u.ws.rx_packet_length = ((size_t)c) << 56;
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#else
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wsi->u.ws.rx_packet_length = 0;
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#endif
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wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_7;
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break;
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case LWS_RXPS_04_FRAME_HDR_LEN64_7:
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#if defined __LP64__
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wsi->u.ws.rx_packet_length |= ((size_t)c) << 48;
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#endif
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wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_6;
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break;
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case LWS_RXPS_04_FRAME_HDR_LEN64_6:
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#if defined __LP64__
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wsi->u.ws.rx_packet_length |= ((size_t)c) << 40;
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#endif
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wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_5;
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break;
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case LWS_RXPS_04_FRAME_HDR_LEN64_5:
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#if defined __LP64__
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wsi->u.ws.rx_packet_length |= ((size_t)c) << 32;
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#endif
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wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_4;
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break;
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case LWS_RXPS_04_FRAME_HDR_LEN64_4:
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wsi->u.ws.rx_packet_length |= ((size_t)c) << 24;
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wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_3;
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break;
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case LWS_RXPS_04_FRAME_HDR_LEN64_3:
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wsi->u.ws.rx_packet_length |= ((size_t)c) << 16;
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wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_2;
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break;
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case LWS_RXPS_04_FRAME_HDR_LEN64_2:
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wsi->u.ws.rx_packet_length |= ((size_t)c) << 8;
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wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_1;
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break;
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case LWS_RXPS_04_FRAME_HDR_LEN64_1:
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wsi->u.ws.rx_packet_length |= (size_t)c;
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if (wsi->u.ws.this_frame_masked)
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wsi->lws_rx_parse_state =
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LWS_RXPS_07_COLLECT_FRAME_KEY_1;
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else {
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if (wsi->u.ws.rx_packet_length)
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wsi->lws_rx_parse_state =
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LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
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else {
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wsi->lws_rx_parse_state = LWS_RXPS_NEW;
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goto spill;
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}
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}
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break;
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case LWS_RXPS_07_COLLECT_FRAME_KEY_1:
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wsi->u.ws.frame_masking_nonce_04[0] = c;
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if (c)
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wsi->u.ws.all_zero_nonce = 0;
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wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_2;
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break;
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case LWS_RXPS_07_COLLECT_FRAME_KEY_2:
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wsi->u.ws.frame_masking_nonce_04[1] = c;
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if (c)
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wsi->u.ws.all_zero_nonce = 0;
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wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_3;
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break;
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case LWS_RXPS_07_COLLECT_FRAME_KEY_3:
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wsi->u.ws.frame_masking_nonce_04[2] = c;
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if (c)
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wsi->u.ws.all_zero_nonce = 0;
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wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_4;
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break;
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case LWS_RXPS_07_COLLECT_FRAME_KEY_4:
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wsi->u.ws.frame_masking_nonce_04[3] = c;
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if (c)
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wsi->u.ws.all_zero_nonce = 0;
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if (wsi->u.ws.rx_packet_length)
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wsi->lws_rx_parse_state =
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LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
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else {
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wsi->lws_rx_parse_state = LWS_RXPS_NEW;
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goto spill;
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}
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break;
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case LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED:
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if (!wsi->u.ws.rx_user_buffer)
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lwsl_err("NULL client rx_user_buffer\n");
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if ((!wsi->u.ws.this_frame_masked) || wsi->u.ws.all_zero_nonce)
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wsi->u.ws.rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING +
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(wsi->u.ws.rx_user_buffer_head++)] = c;
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else
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wsi->u.ws.rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING +
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(wsi->u.ws.rx_user_buffer_head++)] =
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c ^ wsi->u.ws.frame_masking_nonce_04[
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(wsi->u.ws.frame_mask_index++) & 3];
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if (--wsi->u.ws.rx_packet_length == 0) {
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/* spill because we have the whole frame */
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wsi->lws_rx_parse_state = LWS_RXPS_NEW;
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goto spill;
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}
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/*
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* if there's no protocol max frame size given, we are
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* supposed to default to LWS_MAX_SOCKET_IO_BUF
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*/
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if (!wsi->protocol->rx_buffer_size &&
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wsi->u.ws.rx_user_buffer_head !=
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LWS_MAX_SOCKET_IO_BUF)
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break;
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else
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if (wsi->protocol->rx_buffer_size &&
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wsi->u.ws.rx_user_buffer_head !=
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wsi->protocol->rx_buffer_size)
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break;
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/* spill because we filled our rx buffer */
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spill:
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handled = 0;
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/*
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* is this frame a control packet we should take care of at this
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* layer? If so service it and hide it from the user callback
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*/
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switch (wsi->u.ws.opcode) {
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case LWS_WS_OPCODE_07__CLOSE:
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/* is this an acknowledgement of our close? */
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if (wsi->state == WSI_STATE_AWAITING_CLOSE_ACK) {
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/*
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* fine he has told us he is closing too, let's
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* finish our close
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*/
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lwsl_parser("seen server's close ack\n");
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return -1;
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}
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lwsl_parser("client sees server close len = %d\n",
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wsi->u.ws.rx_user_buffer_head);
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/*
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* parrot the close packet payload back
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* we do not care about how it went, we are closing
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* immediately afterwards
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*/
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libwebsocket_write(wsi, (unsigned char *)
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&wsi->u.ws.rx_user_buffer[
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LWS_SEND_BUFFER_PRE_PADDING],
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wsi->u.ws.rx_user_buffer_head, LWS_WRITE_CLOSE);
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wsi->state = WSI_STATE_RETURNED_CLOSE_ALREADY;
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/* close the connection */
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return -1;
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case LWS_WS_OPCODE_07__PING:
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lwsl_info("client received ping, doing pong\n");
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/*
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* parrot the ping packet payload back as a pong
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* !!! this may block or have partial write or fail
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* !!! very unlikely if the ping size is small
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*/
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libwebsocket_write(wsi, (unsigned char *)
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&wsi->u.ws.rx_user_buffer[
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LWS_SEND_BUFFER_PRE_PADDING],
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wsi->u.ws.rx_user_buffer_head,
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LWS_WRITE_PONG);
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handled = 1;
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break;
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case LWS_WS_OPCODE_07__PONG:
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lwsl_info("client receied pong\n");
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lwsl_hexdump(&wsi->u.ws.rx_user_buffer[
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LWS_SEND_BUFFER_PRE_PADDING],
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wsi->u.ws.rx_user_buffer_head);
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/* issue it */
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callback_action = LWS_CALLBACK_CLIENT_RECEIVE_PONG;
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break;
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case LWS_WS_OPCODE_07__CONTINUATION:
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case LWS_WS_OPCODE_07__TEXT_FRAME:
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case LWS_WS_OPCODE_07__BINARY_FRAME:
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break;
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default:
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lwsl_parser("Reserved opc 0x%2X\n", wsi->u.ws.opcode);
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/*
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* It's something special we can't understand here.
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* Pass the payload up to the extension's parsing
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* state machine.
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*/
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eff_buf.token = &wsi->u.ws.rx_user_buffer[
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LWS_SEND_BUFFER_PRE_PADDING];
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eff_buf.token_len = wsi->u.ws.rx_user_buffer_head;
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if (lws_ext_callback_for_each_active(wsi,
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LWS_EXT_CALLBACK_EXTENDED_PAYLOAD_RX,
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&eff_buf, 0) <= 0) { /* not handle or fail */
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lwsl_ext("Unhandled ext opc 0x%x\n",
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wsi->u.ws.opcode);
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wsi->u.ws.rx_user_buffer_head = 0;
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return 0;
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}
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handled = 1;
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break;
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}
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/*
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* No it's real payload, pass it up to the user callback.
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* It's nicely buffered with the pre-padding taken care of
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* so it can be sent straight out again using libwebsocket_write
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*/
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if (handled)
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goto already_done;
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eff_buf.token = &wsi->u.ws.rx_user_buffer[
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LWS_SEND_BUFFER_PRE_PADDING];
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eff_buf.token_len = wsi->u.ws.rx_user_buffer_head;
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if (lws_ext_callback_for_each_active(wsi,
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LWS_EXT_CALLBACK_PAYLOAD_RX,
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&eff_buf, 0) < 0) /* fail */
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return -1;
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if (eff_buf.token_len <= 0 &&
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callback_action != LWS_CALLBACK_CLIENT_RECEIVE_PONG)
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goto already_done;
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eff_buf.token[eff_buf.token_len] = '\0';
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if (!wsi->protocol->callback)
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goto already_done;
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if (callback_action == LWS_CALLBACK_CLIENT_RECEIVE_PONG)
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lwsl_info("Client doing pong callback\n");
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m = wsi->protocol->callback(
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wsi->protocol->owning_server,
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wsi,
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(enum libwebsocket_callback_reasons)callback_action,
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wsi->user_space,
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eff_buf.token,
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eff_buf.token_len);
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/* if user code wants to close, let caller know */
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if (m)
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return 1;
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already_done:
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wsi->u.ws.rx_user_buffer_head = 0;
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break;
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default:
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lwsl_err("client rx illegal state\n");
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return 1;
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}
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return 0;
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illegal_ctl_length:
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lwsl_warn("Control frame asking for extended length is illegal\n");
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/* kill the connection */
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return -1;
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}
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