《視頻處理與傳輸》實驗報告材料

?視頻辦理與傳輸?實驗報告資料?視頻辦理與傳輸?實驗報告資料?視頻辦理與傳輸?實驗報告資料適用標準文案西南科技大學?視頻辦理與傳輸?實驗報告題目：實驗三設計者：專業(yè)班級：學號：指導教師：2021年12月23日優(yōu)異文檔適用標準文案一、實驗目的1．認識和認識TCP的有關內容；2．學習和掌握TCP模塊的C語言編程；3．試一試用C語言寫出TCP有限狀態(tài)機的實現(xiàn)函數(shù)二、實驗內容TCP〔TransmissionControlProtocol傳輸控制協(xié)議〕是一種面向連結〔連接導向〕的、靠譜的、鑒于IP的傳輸層協(xié)議，由IETF的RFC793說明〔specified〕。TCP在IP報文的協(xié)議號是6。設計一個C程序實現(xiàn)TCP。三、實驗過程1、創(chuàng)辦一頭文件，包含C語言實現(xiàn)TCP的全部常量。2、達成struct語句，它是TCP首部的說明語句。3、達成struct語句，它是TCP報文的說明語句。4、用C語言寫出TCP有限狀態(tài)機的函數(shù)。四、實驗結果及分析1、頭文件#ifndef_TCP_H#define_TCP_H#include<stdio.h>#include<stdlib.h>#include<errno.h>#include<string.h>#include<sys/types.h>#include<netinet/in.h>#include<sys/socket.h>#include<sys/wait.h>#defineSERVERPORT3333/*效力器監(jiān)聽端口號*/#defineBACKLOG10/*最大同時連結懇求數(shù)*/#endif優(yōu)異文檔適用標準文案2、TCP首部：structTCP_Header{u_charbyte1;u_charbyte2;u_charbyte3;u_charbyte4;}ip_address;/*IPv4首部*/structTCP_header{unsignedshortSPortAddru_charver_ihl;//版本(4bits)+首部長度(4bits)==8u_chartos;//效力種類(Typeofservice)u_shorttlen;//總長(Totallength)u_shortidentification;//表記(Identification)u_shortflags_fo;//標記位(Flags)(3bits)+段偏移量(Fragmentoffset)(13bits)u_charttl;//存活時間(Timetolive)u_charproto;//協(xié)議(Protocol)u_shortcrc;//首部校驗和(Headerchecksum)ip_addresssaddr;//源地點(Sourceaddress)ip_addressdaddr;//目的地點(Destinationaddress)u_intop_pad;//選項與填補(Option+Padding)}ip_header;3、structTCPPacket{structTCP_HeadertcpHeader;uint16source;/*Sourceport*/uint16dest;/*Destinationport*/int32seq;/*Sequencenumber*/int32ack;/*Acknowledgmentnumber*/uint16wnd;/*Receiverflowcontrolwindow*/uint16checksum;/*Checksum*/uint16up;/*Urgentpointer*/uint16mss;/*Optionalmaxsegsize*/uint8wsopt;/*Optionalwindowscalefactor*/優(yōu)異文檔適用標準文案uint32tsval;/*Outboundtimestamp*/uint32tsecr;/*Timestampechofield*/struct{unsignedintcongest:1;/*EchoedIPcongestionexperiencedbit*/unsignedinturg:1;unsignedintack:1;unsignedintpsh:1;unsignedintrst:1;unsignedintsyn:1;unsignedintfin:1;unsignedintmss:1;/*MSSoptionpresent*/unsignedintwscale:1;/*Windowscaleoptionpresent*/unsignedinttstamp:1;/*Timestampoptionpresent*/tcpData;}};4、TCP有限狀態(tài)機#include"global.h"#include"timer.h"#include"mbuf.h"#include"netuser.h"#include"internet.h"#include"tcp.h"#include"ip.h"voidtcp_output(tcb)registerstructtcb*tcb;{structmbuf*dbp;/*Headeranddatabufferpointers*/structtcpseg;/*Localworkingcopyofheader*/uint16ssize;/*Sizeofcurrentsegmentbeingsent,*includingSYNandFINflags*/uint16dsize;/*SizeofsegmentlessSYNandFIN*/int32usable;/*Usablewindow*/int32sent;/*Sequencecount(inclSYN/FIN)already*inthepipebutnotyetacked*/優(yōu)異文檔適用標準文案int32rto;/*Retransmittimeoutsetting*/if(tcb==NULL)return;switch(tcb->state){caseTCP_LISTEN:caseTCP_CLOSED:return;/*Don'tsendanything*/}for(;;){memset(&seg,0,sizeof(seg));/*Computedataalreadyinflight*/sent=tcb->snd.ptr-tcb->snd.una;usable=min(tcb->snd.wnd,tcb->cwind);if(usable>sent)usable-=sent;/*Mostcommoncase*/elseif(usable==0&&sent==0)usable=1;/*Closedwindowprobe*/elseusable=0;/*Windowclosedorshrunken*/ssize=min(tcb->sndcnt-sent,usable);ssize=min(ssize,tcb->mss);&&sent!=0&&ssize<tcb->mss&&!(tcb->state==TCP_FINWAIT1&&ssize==tcb->sndcnt-sent)){ssize=0;}if(!tcb->flags.synack&&!Tcp_syndata){if(tcb->snd.ptr==tcb->iss)ssize=min(1,ssize);/*SendonlySYN*/elsessize=0;/*Don'tsendanything*/}if(tcb->flags.force&&tcb->snd.ptr!=tcb->snd.nxt)ssize=0;if(ssize==0&&!tcb->flags.force)break;/*Noneedtosendanything*/tcb->flags.force=0;/*Onlyoneforcedsegment!*/seg.source=tcb->conn.local.port;seg.dest=tcb->conn.remote.port;=1;/*EverystateexceptTCP_SYN_SENT*/seg.flags.congest=tcb->flags.congest;優(yōu)異文檔適用標準文案if(tcb->state==TCP_SYN_SENT)seg.flags.ack=0;/*Haven'tseenanythingyet*/dsize=ssize;if(!tcb->flags.synack&&tcb->snd.ptr==tcb->iss){/*SendSYN*/seg.flags.syn=1;dsize--;/*SYNisn'treallyinsndqueue*//*AlsosendMSS,wscaleandtstamp(ifOK)*/seg.mss=Tcp_mss;seg.flags.mss=1;seg.wsopt=DEF_WSCALE;seg.flags.wscale=1;if(Tcp_tstamps){seg.flags.tstamp=1;seg.tsval=msclock();}}if(ssize==0)seg.seq=tcb->snd.nxt;elseseg.seq=tcb->snd.ptr;tcb->last_ack_sent=seg.ack=tcb->rcv.nxt;if(seg.flags.syn||!tcb->flags.ws_ok)seg.wnd=tcb->rcv.wnd;elseseg.wnd=tcb->rcv.wnd>>tcb->rcv.wind_scale;dbp=ambufw(TCP_HDR_PAD+dsize);dbp->data+=TCP_HDR_PAD;/*Allowroomforotherhdrs*/If(dsize!=0){int32offset;offset=sent;if(!tcb->flags.synack&&sent!=0)offset--;dbp->cnt=extract(tcb->sndq,(uint16)offset,dbp->data,dsize);if(dbp->cnt!=dsize){/*Weranpasttheendofthesendqueue;*sendaFIN*/seg.flags.fin=1;dsize--;}}if(dsize!=0&&sent+ssize==tcb->sndcnt)優(yōu)異文檔適用標準文案seg.flags.psh=1;if(tcb->snd.ptr<tcb->snd.nxt)tcb->resent+=-tcb->snd.ptr,ssize);tcb->snd.ptr+=ssize;if(seq_gt(tcb->snd.ptr,tcb->snd.nxt))tcb->snd.nxt=tcb->snd.ptr;if(tcb->flags.ts_ok&&seg.flags.ack){seg.flags.tstamp=1;seg.tsval=msclock();seg.tsecr=tcb->ts_recent;}/*GenerateTCPheader,computechecksum,andlinkindata*/htontcp(&seg,&dbp,tcb->conn.local.address,tcb->conn.remote.address)if(ssize!=0){/*Setroundtriptimer.*/rto=backoff(tcb->backoff)*(4*tcb->mdev+tcb->srtt);set_timer(&tcb->timer,max(MIN_RTO,rto));if(!run_timer(&tcb->timer))start_timer(&tcb->timer);/*Ifroundtriptimerisn'trunning,startit*/if(tcb->flags.ts_ok||!tcb->flags.rtt_run){tcb->flags.rtt_run=1;tcb->rtt_time=msclock();tcb->rttseq=tcb->snd.ptr;tcb->rttack=tcb->snd.una;}}if(tcb->flags.retran)tcpRetransSegs++;elsetcpOutSegs++;ip_send(tcb->conn.local.address,tcb->conn.remote.address,TCP_PTCL,tcb->tos,0,&dbp,len_p(