/* * MIT License * * Copyright (c) 2016 xiongziliang <771730766@qq.com> * * This file is part of ZLMediaKit(https://github.com/xiongziliang/ZLMediaKit). * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in all * copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */ #include "WebSocketSplitter.h" #include #include #include #include "Util/logger.h" #include "Util/util.h" using namespace ZL::Util; namespace ZL { namespace Http { /** * 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|M| Payload len | Extended payload length | |I|S|S|S| (4) |A| (7) | (16/64) | |N|V|V|V| |S| | (if payload len==126/127) | | |1|2|3| |K| | | +-+-+-+-+-------+-+-------------+ - - - - - - - - - - - - - - - + | Extended payload length continued, if payload len == 127 | + - - - - - - - - - - - - - - - +-------------------------------+ | |Masking-key, if MASK set to 1 | +-------------------------------+-------------------------------+ | Masking-key (continued) | Payload Data | +-------------------------------- - - - - - - - - - - - - - - - + : Payload Data continued ... : + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + | Payload Data continued ... | +---------------------------------------------------------------+ */ #define CHECK_LEN(size) \ do{ \ if(len - (ptr - data) < size){ \ if(_remain_data.empty()){ \ _remain_data.assign((char *)data,len); \ } \ return ; \ } \ }while(0) \ void WebSocketSplitter::decode(uint8_t *data,uint64_t len) { uint8_t *ptr = data; if(!_got_header) { //还没有获取数据头 if(!_remain_data.empty()){ _remain_data.append((char *)data,len); data = ptr = (uint8_t *)_remain_data.data(); len = _remain_data.size(); } begin_decode: CHECK_LEN(1); _fin = (*ptr & 0x80) >> 7; _reserved = (*ptr & 0x70) >> 4; _opcode = (WebSocketHeader::Type) (*ptr & 0x0F); ptr += 1; CHECK_LEN(1); _mask_flag = (*ptr & 0x80) >> 7; _playload_len = (*ptr & 0x7F); ptr += 1; if (_playload_len == 126) { CHECK_LEN(2); _playload_len = (*ptr << 8) | *(ptr + 1); ptr += 2; } else if (_playload_len == 127) { CHECK_LEN(8); _playload_len = ((uint64_t) ptr[0] << (8 * 7)) | ((uint64_t) ptr[1] << (8 * 6)) | ((uint64_t) ptr[2] << (8 * 5)) | ((uint64_t) ptr[3] << (8 * 4)) | ((uint64_t) ptr[4] << (8 * 3)) | ((uint64_t) ptr[5] << (8 * 2)) | ((uint64_t) ptr[6] << (8 * 1)) | ((uint64_t) ptr[7] << (8 * 0)); ptr += 8; } if (_mask_flag) { CHECK_LEN(4); _mask.assign(ptr, ptr + 4); ptr += 4; } _got_header = true; _mask_offset = 0; _playload_offset = 0; onWebSocketDecodeHeader(*this); } //进入后面逻辑代表已经获取到了webSocket协议头， uint64_t remain = len - (ptr - data); if(remain > 0){ uint64_t playload_slice_len = remain; if(playload_slice_len + _playload_offset > _playload_len){ playload_slice_len = _playload_len - _playload_offset; } _playload_offset += playload_slice_len; onPlayloadData(ptr,playload_slice_len); if(_playload_offset == _playload_len){ //这是下一个包 remain -= playload_slice_len; ptr += playload_slice_len; _got_header = false; if(remain > 0){ //剩余数据是下一个包，把它的数据放置在缓存中 _remain_data.assign((char *)ptr,remain); data = ptr = (uint8_t *)_remain_data.data(); len = _remain_data.size(); goto begin_decode; } } } _remain_data.clear(); } void WebSocketSplitter::onPlayloadData(uint8_t *ptr, uint64_t len) { if(_mask_flag){ for(int i = 0; i < len ; ++i,++ptr){ *(ptr) ^= _mask[(i + _mask_offset) % 4]; } _mask_offset = (_mask_offset + len) % 4; } onWebSocketDecodePlayload(*this, _mask_flag ? ptr - len : ptr, len, _playload_offset); } void WebSocketSplitter::encode(uint8_t *data, uint64_t len) { string ret; uint8_t byte = _fin << 7 | ((_reserved & 0x07) << 4) | (_opcode & 0x0F) ; ret.push_back(byte); _mask_flag = (_mask_flag && _mask.size() >= 4); byte = _mask_flag << 7; _playload_len = len; if(_playload_len < 126){ byte |= _playload_len; ret.push_back(byte); }else if(_playload_len <= 0xFFFF){ byte |= 126; ret.push_back(byte); uint16_t len = htons(_playload_len); ret.append((char *)&len,2); }else{ byte |= 127; ret.push_back(byte); uint32_t len_high = htonl(_playload_len >> 32) ; uint32_t len_low = htonl(_playload_len & 0xFFFFFFFF); ret.append((char *)&len_high,4); ret.append((char *)&len_low,4); } if(_mask_flag){ ret.append((char *)_mask.data(),4); } onWebSocketEncodeData((uint8_t*)ret.data(),ret.size()); if(_mask_flag){ uint8_t *ptr = data; for(int i = 0; i < len ; ++i,++ptr){ *(ptr) ^= _mask[i % 4]; } } onWebSocketEncodeData(data,len); } } /* namespace Http */ } /* namespace ZL */