| /* |
| * 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; |
| |
| } |
| |
| |