/* * libwebsockets - small server side websockets and web server implementation * * Copyright (C) 2010 Andy Green * * 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" #ifdef WIN32 #include #endif static const struct lws_tokens lws_tokens[WSI_TOKEN_COUNT] = { /* win32 can't do C99 */ /* [WSI_TOKEN_GET_URI] = */{ "GET ", 4 }, /* [WSI_TOKEN_HOST] = */{ "Host:", 5 }, /* [WSI_TOKEN_CONNECTION] = */{ "Connection:", 11 }, /* [WSI_TOKEN_KEY1] = */{ "Sec-WebSocket-Key1:", 19 }, /* [WSI_TOKEN_KEY2] = */{ "Sec-WebSocket-Key2:", 19 }, /* [WSI_TOKEN_PROTOCOL] = */{ "Sec-WebSocket-Protocol:", 23 }, /* [WSI_TOKEN_UPGRADE] = */{ "Upgrade:", 8 }, /* [WSI_TOKEN_ORIGIN] = */{ "Origin:", 7 }, /* [WSI_TOKEN_DRAFT] = */{ "Sec-WebSocket-Draft:", 20 }, /* [WSI_TOKEN_CHALLENGE] = */{ "\x0d\x0a", 2 }, /* [WSI_TOKEN_KEY] = */{ "Sec-WebSocket-Key:", 18 }, /* [WSI_TOKEN_VERSION] = */{ "Sec-WebSocket-Version:", 22 }, /* [WSI_TOKEN_SWORIGIN]= */{ "Sec-WebSocket-Origin:", 21 }, /* [WSI_TOKEN_EXTENSIONS] = */{ "Sec-WebSocket-Extensions:", 25 }, /* [WSI_TOKEN_ACCEPT] = */{ "Sec-WebSocket-Accept:", 21 }, /* [WSI_TOKEN_NONCE] = */{ "Sec-WebSocket-Nonce:", 20 }, /* [WSI_TOKEN_HTTP] = */{ "HTTP/1.1 ", 9 }, /* [WSI_TOKEN_MUXURL] = */{ "", -1 }, }; int libwebsocket_parse(struct libwebsocket *wsi, unsigned char c) { int n; switch (wsi->parser_state) { case WSI_TOKEN_GET_URI: case WSI_TOKEN_HOST: case WSI_TOKEN_CONNECTION: case WSI_TOKEN_KEY1: case WSI_TOKEN_KEY2: case WSI_TOKEN_PROTOCOL: case WSI_TOKEN_UPGRADE: case WSI_TOKEN_ORIGIN: case WSI_TOKEN_SWORIGIN: case WSI_TOKEN_DRAFT: case WSI_TOKEN_CHALLENGE: case WSI_TOKEN_KEY: case WSI_TOKEN_VERSION: case WSI_TOKEN_ACCEPT: case WSI_TOKEN_NONCE: case WSI_TOKEN_EXTENSIONS: case WSI_TOKEN_HTTP: case WSI_TOKEN_MUXURL: lwsl_parser("WSI_TOKEN_(%d) '%c'\n", wsi->parser_state, c); /* collect into malloc'd buffers */ /* optional space swallow */ if (!wsi->utf8_token[wsi->parser_state].token_len && c == ' ') break; /* special case space terminator for get-uri */ if (wsi->parser_state == WSI_TOKEN_GET_URI && c == ' ') { wsi->utf8_token[wsi->parser_state].token[ wsi->utf8_token[wsi->parser_state].token_len] = '\0'; // lwsl_parser("uri '%s'\n", wsi->utf8_token[wsi->parser_state].token); wsi->parser_state = WSI_TOKEN_SKIPPING; break; } /* allocate appropriate memory */ if (wsi->utf8_token[wsi->parser_state].token_len == wsi->current_alloc_len - 1) { /* need to extend */ wsi->current_alloc_len += LWS_ADDITIONAL_HDR_ALLOC; if (wsi->current_alloc_len >= LWS_MAX_HEADER_LEN) { /* it's waaay to much payload, fail it */ strcpy(wsi->utf8_token[wsi->parser_state].token, "!!! Length exceeded maximum supported !!!"); wsi->parser_state = WSI_TOKEN_SKIPPING; break; } wsi->utf8_token[wsi->parser_state].token = (char *) realloc(wsi->utf8_token[wsi->parser_state].token, wsi->current_alloc_len); if (wsi->utf8_token[wsi->parser_state].token == NULL) { lwsl_err("Out of mem\n"); return -1; } } /* bail at EOL */ if (wsi->parser_state != WSI_TOKEN_CHALLENGE && c == '\x0d') { wsi->utf8_token[wsi->parser_state].token[ wsi->utf8_token[wsi->parser_state].token_len] = '\0'; wsi->parser_state = WSI_TOKEN_SKIPPING_SAW_CR; lwsl_parser("*\n"); break; } wsi->utf8_token[wsi->parser_state].token[ wsi->utf8_token[wsi->parser_state].token_len++] = c; /* per-protocol end of headers management */ if (wsi->parser_state != WSI_TOKEN_CHALLENGE) break; /* -76 has no version header ... server */ if (!wsi->utf8_token[WSI_TOKEN_VERSION].token_len && wsi->mode != LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY && wsi->utf8_token[wsi->parser_state].token_len != 8) break; /* -76 has no version header ... client */ if (!wsi->utf8_token[WSI_TOKEN_VERSION].token_len && wsi->mode == LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY && wsi->utf8_token[wsi->parser_state].token_len != 16) break; /* <= 03 has old handshake with version header needs 8 bytes */ if (wsi->utf8_token[WSI_TOKEN_VERSION].token_len && atoi(wsi->utf8_token[WSI_TOKEN_VERSION].token) < 4 && wsi->utf8_token[wsi->parser_state].token_len != 8) break; /* no payload challenge in 01 + */ if (wsi->utf8_token[WSI_TOKEN_VERSION].token_len && atoi(wsi->utf8_token[WSI_TOKEN_VERSION].token) > 0) { wsi->utf8_token[WSI_TOKEN_CHALLENGE].token_len = 0; free(wsi->utf8_token[WSI_TOKEN_CHALLENGE].token); wsi->utf8_token[WSI_TOKEN_CHALLENGE].token = NULL; } /* For any supported protocol we have enough payload */ lwsl_parser("Setting WSI_PARSING_COMPLETE\n"); wsi->parser_state = WSI_PARSING_COMPLETE; break; case WSI_INIT_TOKEN_MUXURL: wsi->parser_state = WSI_TOKEN_MUXURL; wsi->current_alloc_len = LWS_INITIAL_HDR_ALLOC; wsi->utf8_token[wsi->parser_state].token = (char *) malloc(wsi->current_alloc_len); if (wsi->utf8_token[wsi->parser_state].token == NULL) { lwsl_err("Out of mem\n"); return -1; } wsi->utf8_token[wsi->parser_state].token_len = 0; break; /* collecting and checking a name part */ case WSI_TOKEN_NAME_PART: lwsl_parser("WSI_TOKEN_NAME_PART '%c'\n", c); if (wsi->name_buffer_pos == sizeof(wsi->name_buffer) - 1) { /* name bigger than we can handle, skip until next */ wsi->parser_state = WSI_TOKEN_SKIPPING; break; } wsi->name_buffer[wsi->name_buffer_pos++] = c; wsi->name_buffer[wsi->name_buffer_pos] = '\0'; for (n = 0; n < WSI_TOKEN_COUNT; n++) { if (wsi->name_buffer_pos != lws_tokens[n].token_len) continue; if (strcasecmp(lws_tokens[n].token, wsi->name_buffer)) continue; lwsl_parser("known hdr '%s'\n", wsi->name_buffer); /* * WSORIGIN is protocol equiv to ORIGIN, * JWebSocket likes to send it, map to ORIGIN */ if (n == WSI_TOKEN_SWORIGIN) n = WSI_TOKEN_ORIGIN; wsi->parser_state = (enum lws_token_indexes) (WSI_TOKEN_GET_URI + n); n = WSI_TOKEN_COUNT; /* If the header has been seen already, just append */ if (wsi->utf8_token[wsi->parser_state].token) continue; wsi->current_alloc_len = LWS_INITIAL_HDR_ALLOC; wsi->utf8_token[wsi->parser_state].token = (char *) malloc(wsi->current_alloc_len); if (wsi->utf8_token[wsi->parser_state].token == NULL) { lwsl_err("Out of mem\n"); return -1; } wsi->utf8_token[wsi->parser_state].token_len = 0; } /* colon delimiter means we just don't know this name */ if (wsi->parser_state == WSI_TOKEN_NAME_PART) { if (c == ':') { lwsl_parser("skipping unknown header '%s'\n", wsi->name_buffer); wsi->parser_state = WSI_TOKEN_SKIPPING; break; } if (c == ' ' && !wsi->utf8_token[WSI_TOKEN_GET_URI].token_len) { lwsl_parser("unknown method '%s'\n", wsi->name_buffer); wsi->parser_state = WSI_TOKEN_GET_URI; wsi->current_alloc_len = LWS_INITIAL_HDR_ALLOC; wsi->utf8_token[WSI_TOKEN_GET_URI].token = (char *)malloc(wsi->current_alloc_len); if (wsi->utf8_token[WSI_TOKEN_GET_URI].token == NULL) { lwsl_err("Out of mem\n"); return -1; } break; } } if (wsi->parser_state != WSI_TOKEN_CHALLENGE) break; /* don't look for payload when it can just be http headers */ if (!wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len) { /* they're HTTP headers, not websocket upgrade! */ lwsl_parser("Setting WSI_PARSING_COMPLETE " "from http headers\n"); wsi->parser_state = WSI_PARSING_COMPLETE; } /* 04 version has no packet content after end of hdrs */ if (wsi->utf8_token[WSI_TOKEN_VERSION].token_len && atoi(wsi->utf8_token[WSI_TOKEN_VERSION].token) >= 4) { lwsl_parser("04 header completed\n"); wsi->parser_state = WSI_PARSING_COMPLETE; wsi->utf8_token[WSI_TOKEN_CHALLENGE].token_len = 0; free(wsi->utf8_token[WSI_TOKEN_CHALLENGE].token); wsi->utf8_token[WSI_TOKEN_CHALLENGE].token = NULL; } /* client parser? */ if (wsi->ietf_spec_revision >= 4) { lwsl_parser("04 header completed\n"); wsi->parser_state = WSI_PARSING_COMPLETE; } break; /* skipping arg part of a name we didn't recognize */ case WSI_TOKEN_SKIPPING: lwsl_parser("WSI_TOKEN_SKIPPING '%c'\n", c); if (c == '\x0d') wsi->parser_state = WSI_TOKEN_SKIPPING_SAW_CR; break; case WSI_TOKEN_SKIPPING_SAW_CR: lwsl_parser("WSI_TOKEN_SKIPPING_SAW_CR '%c'\n", c); if (c == '\x0a') wsi->parser_state = WSI_TOKEN_NAME_PART; else wsi->parser_state = WSI_TOKEN_SKIPPING; wsi->name_buffer_pos = 0; break; /* we're done, ignore anything else */ case WSI_PARSING_COMPLETE: lwsl_parser("WSI_PARSING_COMPLETE '%c'\n", c); break; default: /* keep gcc happy */ break; } return 0; } unsigned char xor_no_mask(struct libwebsocket *wsi, unsigned char c) { return c; } unsigned char xor_mask_04(struct libwebsocket *wsi, unsigned char c) { c ^= wsi->masking_key_04[wsi->frame_mask_index++]; if (wsi->frame_mask_index == 20) wsi->frame_mask_index = 0; return c; } unsigned char xor_mask_05(struct libwebsocket *wsi, unsigned char c) { return c ^ wsi->frame_masking_nonce_04[(wsi->frame_mask_index++) & 3]; } int libwebsocket_rx_sm(struct libwebsocket *wsi, unsigned char c) { int n; unsigned char buf[20 + 4]; struct lws_tokens eff_buf; int handled; int m; #if 0 lwsl_debug("RX: %02X ", c); #endif switch (wsi->lws_rx_parse_state) { case LWS_RXPS_NEW: switch (wsi->ietf_spec_revision) { /* Firefox 4.0b6 likes this as of 30 Oct 2010 */ case 0: if (c == 0xff) wsi->lws_rx_parse_state = LWS_RXPS_SEEN_76_FF; if (c == 0) { wsi->lws_rx_parse_state = LWS_RXPS_EAT_UNTIL_76_FF; wsi->rx_user_buffer_head = 0; } break; case 4: case 5: case 6: wsi->all_zero_nonce = 1; wsi->frame_masking_nonce_04[0] = c; if (c) wsi->all_zero_nonce = 0; wsi->lws_rx_parse_state = LWS_RXPS_04_MASK_NONCE_1; break; case 7: case 8: case 13: /* * no prepended frame key any more */ wsi->all_zero_nonce = 1; goto handle_first; default: lwsl_warn("libwebsocket_rx_sm doesn't know " "about spec version %d\n", wsi->ietf_spec_revision); break; } break; case LWS_RXPS_04_MASK_NONCE_1: wsi->frame_masking_nonce_04[1] = c; if (c) wsi->all_zero_nonce = 0; wsi->lws_rx_parse_state = LWS_RXPS_04_MASK_NONCE_2; break; case LWS_RXPS_04_MASK_NONCE_2: wsi->frame_masking_nonce_04[2] = c; if (c) wsi->all_zero_nonce = 0; wsi->lws_rx_parse_state = LWS_RXPS_04_MASK_NONCE_3; break; case LWS_RXPS_04_MASK_NONCE_3: wsi->frame_masking_nonce_04[3] = c; if (c) wsi->all_zero_nonce = 0; if (wsi->protocol->owning_server->options & LWS_SERVER_OPTION_DEFEAT_CLIENT_MASK) goto post_mask; if (wsi->ietf_spec_revision > 4) goto post_sha1; /* * we are able to compute the frame key now * it's a SHA1 of ( frame nonce we were just sent, concatenated * with the connection masking key we computed at handshake * time ) -- yeah every frame from the client invokes a SHA1 * for no real reason so much for lightweight. */ buf[0] = wsi->frame_masking_nonce_04[0]; buf[1] = wsi->frame_masking_nonce_04[1]; buf[2] = wsi->frame_masking_nonce_04[2]; buf[3] = wsi->frame_masking_nonce_04[3]; memcpy(buf + 4, wsi->masking_key_04, 20); /* * wsi->frame_mask_04 will be our recirculating 20-byte XOR key * for this frame */ SHA1((unsigned char *)buf, 4 + 20, wsi->frame_mask_04); post_sha1: /* * start from the zero'th byte in the XOR key buffer since * this is the start of a frame with a new key */ wsi->frame_mask_index = 0; post_mask: wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_1; break; /* * 04 logical framing from the spec (all this is masked when incoming * and has to be unmasked) * * We ignore the possibility of extension data because we don't * negotiate any extensions at the moment. * * 0 1 2 3 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 * +-+-+-+-+-------+-+-------------+-------------------------------+ * |F|R|R|R| opcode|R| Payload len | Extended payload length | * |I|S|S|S| (4) |S| (7) | (16/63) | * |N|V|V|V| |V| | (if payload len==126/127) | * | |1|2|3| |4| | | * +-+-+-+-+-------+-+-------------+ - - - - - - - - - - - - - - - + * | Extended payload length continued, if payload len == 127 | * + - - - - - - - - - - - - - - - +-------------------------------+ * | | Extension data | * +-------------------------------+ - - - - - - - - - - - - - - - + * : : * +---------------------------------------------------------------+ * : Application data : * +---------------------------------------------------------------+ * * We pass payload through to userland as soon as we get it, ignoring * FIN. It's up to userland to buffer it up if it wants to see a * whole unfragmented block of the original size (which may be up to * 2^63 long!) */ case LWS_RXPS_04_FRAME_HDR_1: handle_first: /* * 04 spec defines the opcode like this: (1, 2, and 3 are * "control frame" opcodes which may not be fragmented or * have size larger than 126) * * frame-opcode = * %x0 ; continuation frame * / %x1 ; connection close * / %x2 ; ping * / %x3 ; pong * / %x4 ; text frame * / %x5 ; binary frame * / %x6-F ; reserved * * FIN (b7) */ if (wsi->ietf_spec_revision < 7) c = wsi->xor_mask(wsi, c); /* translate all incoming opcodes into v7+ map */ if (wsi->ietf_spec_revision < 7) switch (c & 0xf) { case LWS_WS_OPCODE_04__CONTINUATION: wsi->opcode = LWS_WS_OPCODE_07__CONTINUATION; break; case LWS_WS_OPCODE_04__CLOSE: wsi->opcode = LWS_WS_OPCODE_07__CLOSE; break; case LWS_WS_OPCODE_04__PING: wsi->opcode = LWS_WS_OPCODE_07__PING; break; case LWS_WS_OPCODE_04__PONG: wsi->opcode = LWS_WS_OPCODE_07__PONG; break; case LWS_WS_OPCODE_04__TEXT_FRAME: wsi->opcode = LWS_WS_OPCODE_07__TEXT_FRAME; break; case LWS_WS_OPCODE_04__BINARY_FRAME: wsi->opcode = LWS_WS_OPCODE_07__BINARY_FRAME; break; default: lwsl_warn("reserved opcodes not " "usable pre v7 protocol\n"); return -1; } else wsi->opcode = c & 0xf; wsi->rsv = (c & 0x70); wsi->final = !!((c >> 7) & 1); wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN; break; case LWS_RXPS_04_FRAME_HDR_LEN: if (wsi->ietf_spec_revision < 7) c = wsi->xor_mask(wsi, c); if ((c & 0x80) && wsi->ietf_spec_revision < 7) { lwsl_warn("Frame has extensions set illegally 2\n"); /* kill the connection */ return -1; } wsi->this_frame_masked = !!(c & 0x80); switch (c & 0x7f) { case 126: /* control frames are not allowed to have big lengths */ if (wsi->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->opcode & 8) goto illegal_ctl_length; wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_8; break; default: wsi->rx_packet_length = c & 0x7f; if (wsi->this_frame_masked) wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_1; else wsi->lws_rx_parse_state = LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED; break; } break; case LWS_RXPS_04_FRAME_HDR_LEN16_2: if (wsi->ietf_spec_revision < 7) c = wsi->xor_mask(wsi, c); wsi->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: if (wsi->ietf_spec_revision < 7) c = wsi->xor_mask(wsi, c); wsi->rx_packet_length |= c; if (wsi->this_frame_masked) wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_1; else wsi->lws_rx_parse_state = LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED; break; case LWS_RXPS_04_FRAME_HDR_LEN64_8: if (wsi->ietf_spec_revision < 7) c = wsi->xor_mask(wsi, c); if (c & 0x80) { lwsl_warn("b63 of length must be zero\n"); /* kill the connection */ return -1; } #if defined __LP64__ wsi->rx_packet_length = ((size_t)c) << 56; #else wsi->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 (wsi->ietf_spec_revision < 7) c = wsi->xor_mask(wsi, c); #if defined __LP64__ wsi->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 (wsi->ietf_spec_revision < 7) c = wsi->xor_mask(wsi, c); #if defined __LP64__ wsi->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 (wsi->ietf_spec_revision < 7) c = wsi->xor_mask(wsi, c); #if defined __LP64__ wsi->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: if (wsi->ietf_spec_revision < 7) c = wsi->xor_mask(wsi, c); wsi->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: if (wsi->ietf_spec_revision < 7) c = wsi->xor_mask(wsi, c); wsi->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: if (wsi->ietf_spec_revision < 7) c = wsi->xor_mask(wsi, c); wsi->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: if (wsi->ietf_spec_revision < 7) c = wsi->xor_mask(wsi, c); wsi->rx_packet_length |= ((size_t)c); if (wsi->this_frame_masked) wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_1; else wsi->lws_rx_parse_state = LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED; break; case LWS_RXPS_EAT_UNTIL_76_FF: if (c == 0xff) { wsi->lws_rx_parse_state = LWS_RXPS_NEW; goto issue; } wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING + (wsi->rx_user_buffer_head++)] = c; if (wsi->rx_user_buffer_head != MAX_USER_RX_BUFFER) break; issue: if (wsi->protocol->callback) wsi->protocol->callback(wsi->protocol->owning_server, wsi, LWS_CALLBACK_RECEIVE, wsi->user_space, &wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING], wsi->rx_user_buffer_head); wsi->rx_user_buffer_head = 0; break; case LWS_RXPS_SEEN_76_FF: if (c) break; lwsl_parser("Seen that client is requesting " "a v76 close, sending ack\n"); buf[0] = 0xff; buf[1] = 0; n = libwebsocket_write(wsi, buf, 2, LWS_WRITE_HTTP); if (n < 0) { lwsl_warn("ERROR writing to socket"); return -1; } lwsl_parser(" v76 close ack sent, server closing skt\n"); /* returning < 0 will get it closed in parent */ return -1; case LWS_RXPS_PULLING_76_LENGTH: break; case LWS_RXPS_07_COLLECT_FRAME_KEY_1: wsi->frame_masking_nonce_04[0] = c; if (c) wsi->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->frame_masking_nonce_04[1] = c; if (c) wsi->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->frame_masking_nonce_04[2] = c; if (c) wsi->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->frame_masking_nonce_04[3] = c; if (c) wsi->all_zero_nonce = 0; wsi->lws_rx_parse_state = LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED; wsi->frame_mask_index = 0; break; case LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED: if (wsi->ietf_spec_revision < 4 || (wsi->all_zero_nonce && wsi->ietf_spec_revision >= 5)) wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING + (wsi->rx_user_buffer_head++)] = c; else wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING + (wsi->rx_user_buffer_head++)] = wsi->xor_mask(wsi, c); if (--wsi->rx_packet_length == 0) { wsi->lws_rx_parse_state = LWS_RXPS_NEW; goto spill; } if (wsi->rx_user_buffer_head != MAX_USER_RX_BUFFER) break; spill: /* * 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 */ lwsl_parser("spill on %s\n", wsi->protocol->name); switch (wsi->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 client close ack\n"); return -1; } lwsl_parser("server sees client close packet\n"); /* parrot the close packet payload back */ n = libwebsocket_write(wsi, (unsigned char *) &wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING], wsi->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("received %d byte ping, sending pong\n", wsi->rx_user_buffer_head); lwsl_hexdump(&wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING], wsi->rx_user_buffer_head); /* parrot the ping packet payload back as a pong */ n = libwebsocket_write(wsi, (unsigned char *) &wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING], wsi->rx_user_buffer_head, LWS_WRITE_PONG); /* ... then just drop it */ wsi->rx_user_buffer_head = 0; return 0; case LWS_WS_OPCODE_07__PONG: /* keep the statistics... */ wsi->pings_vs_pongs--; /* ... then just drop it */ wsi->rx_user_buffer_head = 0; return 0; case LWS_WS_OPCODE_07__CONTINUATION: case LWS_WS_OPCODE_07__TEXT_FRAME: case LWS_WS_OPCODE_07__BINARY_FRAME: break; default: lwsl_parser("passing opcode %x up to exts\n", wsi->opcode); /* * It's something special we can't understand here. * Pass the payload up to the extension's parsing * state machine. */ eff_buf.token = &wsi->rx_user_buffer[ LWS_SEND_BUFFER_PRE_PADDING]; eff_buf.token_len = wsi->rx_user_buffer_head; handled = 0; 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) lwsl_ext("Unhandled extended opcode " "0x%x - ignoring frame\n", wsi->opcode); wsi->rx_user_buffer_head = 0; return 0; } /* * 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 */ eff_buf.token = &wsi->rx_user_buffer[ LWS_SEND_BUFFER_PRE_PADDING]; eff_buf.token_len = wsi->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_PAYLOAD_RX, wsi->active_extensions_user[n], &eff_buf, 0); if (m < 0) { lwsl_ext( "Extension '%s' failed to handle payload!\n", wsi->active_extensions[n]->name); return -1; } } if (eff_buf.token_len > 0) { eff_buf.token[eff_buf.token_len] = '\0'; if (wsi->protocol->callback) wsi->protocol->callback(wsi->protocol->owning_server, wsi, LWS_CALLBACK_RECEIVE, wsi->user_space, eff_buf.token, eff_buf.token_len); else lwsl_err("No callback on payload spill!\n"); } wsi->rx_user_buffer_head = 0; break; } return 0; illegal_ctl_length: lwsl_warn("Control frame asking for " "extended length is illegal\n"); /* kill the connection */ return -1; } int libwebsocket_interpret_incoming_packet(struct libwebsocket *wsi, unsigned char *buf, size_t len) { size_t n; #ifdef DEBUG lwsl_parser("received %d byte packet\n", (int)len); for (n = 0; n < len; n++) lwsl_parser("%02X ", buf[n]); lwsl_parser("\n"); #endif /* let the rx protocol state machine have as much as it needs */ n = 0; while (n < len) if (libwebsocket_rx_sm(wsi, buf[n++]) < 0) return -1; return 0; } /** * libwebsockets_remaining_packet_payload() - Bytes to come before "overall" * rx packet is complete * @wsi: Websocket instance (available from user callback) * * This function is intended to be called from the callback if the * user code is interested in "complete packets" from the client. * libwebsockets just passes through payload as it comes and issues a buffer * additionally when it hits a built-in limit. The LWS_CALLBACK_RECEIVE * callback handler can use this API to find out if the buffer it has just * been given is the last piece of a "complete packet" from the client -- * when that is the case libwebsockets_remaining_packet_payload() will return * 0. * * Many protocols won't care becuse their packets are always small. */ size_t libwebsockets_remaining_packet_payload(struct libwebsocket *wsi) { return wsi->rx_packet_length; }