目錄
1--TCP/IP協(xié)議棧
2--TCP服務(wù)器端默認(rèn)函數(shù)調(diào)用順序
3--TCP客戶端的默認(rèn)函數(shù)調(diào)用順序
4--Linux實(shí)現(xiàn)迭代回聲服務(wù)器端/客戶端
5--Windows實(shí)現(xiàn)迭代回聲服務(wù)器端/客戶端
6--TCP原理
7--Windows實(shí)現(xiàn)計(jì)算器服務(wù)器端/客戶端
1--TCP/IP協(xié)議棧
????????TCP/IP協(xié)議棧共分 4 層,可以理解為數(shù)據(jù)收發(fā)分成了 4 個(gè)層次化過(guò)程;
鏈路層:
? ? ? ? 鏈路層是物理鏈接領(lǐng)域標(biāo)準(zhǔn)化的結(jié)果,專門定義LAN、WAN、MAN等網(wǎng)絡(luò)標(biāo)準(zhǔn);
IP層:
? ? ? ? IP層用于解決數(shù)據(jù)傳輸過(guò)程中路徑的選擇問(wèn)題;
TCP/IP層:
????????即傳輸層,用于解決數(shù)據(jù)傳輸?shù)膯?wèn)題(數(shù)據(jù)順序、可靠性等);
應(yīng)用層:
????????程序員根據(jù)數(shù)據(jù)傳輸規(guī)則,編寫規(guī)定的程序(例如Socket)來(lái)實(shí)現(xiàn)數(shù)據(jù)傳輸;
2--TCP服務(wù)器端默認(rèn)函數(shù)調(diào)用順序
? ? ? ? 一般 TCP 服務(wù)器端調(diào)用默認(rèn)函數(shù)的順序如下:socket() 創(chuàng)建 Socket?→ bind() 分配Socket 地址 → listen() 等待連接請(qǐng)求狀態(tài) → accept() 允許連接 → read()/write() 數(shù)據(jù)交換 → close() 斷開(kāi)連接;
? ? ? ? 調(diào)用 listen() 函數(shù)進(jìn)入等待連接請(qǐng)求狀態(tài),只有服務(wù)器端調(diào)用了 listen() 函數(shù),客戶端才能進(jìn)入可發(fā)出連接請(qǐng)求的狀態(tài);
#include <sys/socket.h>
int listen(int sock, int backlog); // 成功時(shí)返回 0, 失敗時(shí)返回 -1;
// sock 表示希望進(jìn)入等待連接請(qǐng)求狀態(tài)的Socket的文件描述符
// backlog 表示連接請(qǐng)求等待隊(duì)列的長(zhǎng)度,即最多可以使多少個(gè)連接請(qǐng)求進(jìn)入隊(duì)列
? ? ? ? 服務(wù)器端調(diào)用 accept() 函數(shù)來(lái)受理客戶端的連接請(qǐng)求,即受理等待隊(duì)列中待處理的客戶端連接請(qǐng)求;
#include <sys/socket.h>
int accept(int sock, struct sockaddr* addr, socklen_t* addrlen);
// 成功時(shí)返回創(chuàng)建的Socket的文件描述符,失敗時(shí)返回-1
3--TCP客戶端的默認(rèn)函數(shù)調(diào)用順序
? ? ? ? 一般 TCP 客戶端調(diào)用默認(rèn)函數(shù)的順序如下:socket() 創(chuàng)建 Socket?→ connect() 請(qǐng)求連接 → read()/write() 交換數(shù)據(jù) → close() 斷開(kāi)連接;
? ? ? ? 在服務(wù)器端調(diào)用 listen() 函數(shù)創(chuàng)建連接請(qǐng)求等待隊(duì)列后,客戶端可通過(guò)調(diào)用 connect() 函數(shù)來(lái)請(qǐng)求連接;
#include <sys/socket.h>
int connect(int sock, struct sockaddr* servaddr, socklen_t addrlen);
// sock 表示客戶端socket的文件描述符
// servaddr 保存了目標(biāo)服務(wù)器端地址信息
// addrlen 第二個(gè)結(jié)構(gòu)體參數(shù) servaddr 的地址變量長(zhǎng)度,以字節(jié)為單位
4--Linux實(shí)現(xiàn)迭代回聲服務(wù)器端/客戶端
服務(wù)器端:
// gcc echo_server.c -o echo_server
// ./echo_server 9190
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#define BUF_SIZE 1024
void error_handling(char *message){
fputs(message, stderr);
fputc('\n', stderr);
exit(1);
}
int main(int argc, char *argv[]){
int serv_sock, clnt_sock;
char message[BUF_SIZE];
int str_len, i;
struct sockaddr_in serv_adr, clnt_adr;
socklen_t clnt_adr_sz;
if(argc != 2){
printf("Usage : %s <port>\n", argv[0]);
exit(1);
}
serv_sock = socket(PF_INET, SOCK_STREAM, 0);
if(serv_sock == -1){
error_handling("socket() error");
}
memset(&serv_adr, 0, sizeof(serv_adr));
serv_adr.sin_family = AF_INET;
serv_adr.sin_addr.s_addr = htonl(INADDR_ANY);
serv_adr.sin_port = htons(atoi(argv[1]));
if(bind(serv_sock, (struct sockaddr*)&serv_adr, sizeof(serv_adr)) == -1){
error_handling("bind() error");
}
if(listen(serv_sock, 5) == -1){
error_handling("listen() error");
}
clnt_adr_sz = sizeof(clnt_adr);
for(i = 0; i < 5; i++){
clnt_sock = accept(serv_sock, (struct sockaddr*)&clnt_adr, &clnt_adr_sz);
if(clnt_sock == -1){
error_handling("accept() error");
}
else{
printf("Connected client %d \n", i+1);
}
while((str_len = read(clnt_sock, message, BUF_SIZE)) != 0){
write(clnt_sock, message, str_len);
}
close(clnt_sock);
}
close(serv_sock);
return 0;
}
客戶端:
// gcc echo_client.c -o echo_client
// ./echo_client 127.0.0.1 9190
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#define BUF_SIZE 1024
void error_handling(char *message){
fputs(message, stderr);
fputc('\n', stderr);
exit(1);
}
int main(int argc, char *argv[]){
int sock;
char message[BUF_SIZE];
int str_len;
struct sockaddr_in serv_adr;
if(argc != 3){
printf("Usage : %s <IP> <port>\n", argv[0]);
exit(1);
}
sock = socket(PF_INET, SOCK_STREAM, 0);
if(sock == -1){
error_handling("socket() error");
}
memset(&serv_adr, 0, sizeof(serv_adr));
serv_adr.sin_family = AF_INET;
serv_adr.sin_addr.s_addr = inet_addr(argv[1]);
serv_adr.sin_port = htons(atoi(argv[2]));
if(connect(sock, (struct sockaddr*)&serv_adr, sizeof(serv_adr)) == -1){
error_handling("connect() error!");
}
else{
puts("Connected.......");
}
while(1){
fputs("Input message(Q to quit): ", stdout);
fgets(message, BUF_SIZE, stdin);
if(!strcmp(message, "q\n") || !strcmp(message, "Q\n")){
break;
}
write(sock, message, strlen(message));
str_len = read(sock, message, BUF_SIZE-1);
message[str_len] = 0;
printf("Message from server: %s", message);
}
close(sock);
return 0;
}
運(yùn)行結(jié)果:
5--Windows實(shí)現(xiàn)迭代回聲服務(wù)器端/客戶端
服務(wù)器端:
// gcc echo_server_win.c -o echo_server_win -lwsock32
// echo_server_win 9190
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <winsock2.h>
#define BUF_SIZE 1024
void ErrorHandling(char *message){
fputs(message, stderr);
fputc('\n', stderr);
exit(1);
}
int main(int argc, char *argv[]){
WSADATA wsaData;
SOCKET hServSock, hClntSock;
char message[BUF_SIZE];
int strLen, i;
SOCKADDR_IN servAdr, clntAdr;
int clntAdrSize;
if(argc != 2){
printf("Usage : %s <port>\n", argv[0]);
exit(1);
}
if(WSAStartup(MAKEWORD(2, 2), &wsaData) != 0){
ErrorHandling("WSAStartup() error!");
}
hServSock = socket(PF_INET, SOCK_STREAM, 0);
if(hServSock == INVALID_SOCKET){
ErrorHandling("socket() error");
}
memset(&servAdr, 0, sizeof(servAdr));
servAdr.sin_family = AF_INET;
servAdr.sin_addr.s_addr = htonl(INADDR_ANY);
servAdr.sin_port = htons(atoi(argv[1]));
if(bind(hServSock, (SOCKADDR*)&servAdr, sizeof(servAdr)) == SOCKET_ERROR){
ErrorHandling("bind() error");
}
if(listen(hServSock, 5) == SOCKET_ERROR){
ErrorHandling("listen() error");
}
clntAdrSize = sizeof(clntAdr);
for(int i = 0; i < 5; i++){
hClntSock = accept(hServSock, (SOCKADDR*)&clntAdr, &clntAdrSize);
if(hClntSock == -1){
ErrorHandling("accept() error");
}
else{
printf("Connected client %d \n", i + 1);
}
while((strLen = recv(hClntSock, message, BUF_SIZE, 0)) != 0){
send(hClntSock, message, strLen, 0);
}
closesocket(hClntSock);
}
closesocket(hServSock);
WSACleanup();
return 0;
}
客戶端:
// gcc echo_client_win.c -o echo_client_win -lwsock32
// echo_client_win 127.0.0.1 9190
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <winsock2.h>
#define BUF_SIZE 1024
void ErrorHandling(char *message){
fputs(message, stderr);
fputc('\n', stderr);
exit(1);
}
int main(int argc, char *argv[]){
WSADATA wsaData;
SOCKET hSocket;
char message[BUF_SIZE];
int strLen;
SOCKADDR_IN servAdr;
if(argc != 3){
printf("Usage: %s <IP> <port>\n", argv[0]);
exit(1);
}
if(WSAStartup(MAKEWORD(2, 2), &wsaData) != 0){
ErrorHandling("WSAStartup() error!");
}
hSocket = socket(PF_INET, SOCK_STREAM, 0);
if(hSocket == INVALID_SOCKET){
ErrorHandling("socket() error");
}
memset(&servAdr, 0, sizeof(servAdr));
servAdr.sin_family = AF_INET;
servAdr.sin_addr.s_addr = inet_addr(argv[1]);
servAdr.sin_port = htons(atoi(argv[2]));
if(connect(hSocket, (SOCKADDR*)&servAdr, sizeof(servAdr)) == SOCKET_ERROR){
ErrorHandling("connect() error!");
}
else{
puts("Connected........");
}
while(1){
fputs("Input message(Q to quit): ", stdout);
fgets(message, BUF_SIZE, stdin);
if(!strcmp(message, "q\n") || !strcmp(message, "Q\n")){
break;
}
send(hSocket, message, strlen(message), 0);
strLen = recv(hSocket, message, BUF_SIZE - 1, 0);
message[strLen] = 0;
printf("Message from server: %s", message);
}
closesocket(hSocket);
WSACleanup();
return 0;
}
測(cè)試結(jié)果:
6--TCP原理
I/O緩沖:
? ? ? ? 當(dāng)調(diào)用 write() 函數(shù)后并不會(huì)立即傳輸數(shù)據(jù),而是將數(shù)據(jù)移至輸出緩沖;
????????同樣當(dāng)調(diào)用 read() 函數(shù)后也并不會(huì)馬上接收數(shù)據(jù),而是將數(shù)據(jù)移至輸入緩沖;
? ? ? ? TCP會(huì)控制數(shù)據(jù)流,使用滑動(dòng)窗口協(xié)議(參考博主之前的筆記:TCP流量控制)來(lái)限制數(shù)據(jù)傳輸不會(huì)超過(guò)輸入緩沖的大??;
TCP 協(xié)議使用三次握手來(lái)建立連接,使用四次揮手來(lái)斷開(kāi)連接;(具體分析參考書(shū)中圖解)
7--Windows實(shí)現(xiàn)計(jì)算器服務(wù)器端/客戶端
服務(wù)器端:
// gcc op_server_win.c -o op_server_win -lwsock32
// op_server_win 9190
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <winsock2.h>
#define BUF_SIZE 1024
#define OPSZ 4
void ErrorHandling(char *message){
fputs(message, stderr);
fputc('\n', stderr);
exit(1);
}
int calculate(int opnum, int opnds[], char op){
int result = opnds[0], i;
switch(op){
case '+':
for(i = 1; i < opnum; i++) result += opnds[i];
break;
case '-':
for(i = 1; i < opnum; i++) result -= opnds[i];
break;
case '*':
for(i = 1; i < opnum; i++) result *= opnds[i];
break;
}
return result;
}
int main(int argc, char* argv[]){
WSADATA wsaData;
SOCKET hServSock, hClntSock;
char opinfo[BUF_SIZE];
int result, opndCnt, i;
int recvCnt, recvLen;
SOCKADDR_IN servAdr, clntAdr;
int clntAdrSize;
if(argc != 2){
printf("Usage: %s <port>\n", argv[0]);
exit(1);
}
if(WSAStartup(MAKEWORD(2, 2), &wsaData) != 0){
ErrorHandling("WSAStartup() error!");
}
hServSock = socket(PF_INET, SOCK_STREAM, 0);
if(hServSock == INVALID_SOCKET){
ErrorHandling("socket() error!");
}
memset(&servAdr, 0, sizeof(servAdr));
servAdr.sin_family = AF_INET;
servAdr.sin_addr.s_addr = htonl(INADDR_ANY);
servAdr.sin_port = htons(atoi(argv[1]));
if(bind(hServSock, (SOCKADDR*)&servAdr, sizeof(servAdr)) == SOCKET_ERROR){
ErrorHandling("bind() error");
}
if(listen(hServSock, 5) == SOCKET_ERROR){
ErrorHandling("listen() error");
}
clntAdrSize = sizeof(clntAdr);
for(int i = 0; i < 5; i++){
opndCnt = 0;
hClntSock = accept(hServSock, (SOCKADDR*)&clntAdr, &clntAdrSize);
recv(hClntSock, (char*)&opndCnt, 1, 0); // recv one byte
recvLen = 0;
while((opndCnt * OPSZ + 1) > recvLen){
recvCnt = recv(hClntSock, &opinfo[recvLen], BUF_SIZE - 1, 0);
recvLen += recvCnt;
}
result = calculate(opndCnt, (int*)opinfo, opinfo[recvLen - 1]);
send(hClntSock, (char*)&result, sizeof(result), 0);
closesocket(hClntSock);
}
closesocket(hServSock);
WSACleanup();
return 0;
}
客戶端:
// gcc op_client_win.c -o op_client_win -lwsock32
// op_client_win 127.0.0.1 9190
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <winsock2.h>
#define BUF_SIZE 1024
#define RLT_SIZE 4
#define OPSZ 4
void ErrorHandling(char *message){
fputs(message, stderr);
fputc('\n', stderr);
exit(1);
}
int main(int argc, char* argv[]){
WSADATA wsaData;
SOCKET hSocket;
char opmsg[BUF_SIZE];
int result, opndCnt, i;
SOCKADDR_IN servAdr;
if(argc != 3){
printf("Usage : %s <IP> <port>\n", argv[0]);
exit(1);
}
if(WSAStartup(MAKEWORD(2, 2), &wsaData) != 0){
ErrorHandling("WSAStartup() error!");
}
hSocket = socket(PF_INET, SOCK_STREAM, 0);
if(hSocket == INVALID_SOCKET){
ErrorHandling("socket() error!");
}
memset(&servAdr, 0, sizeof(servAdr));
servAdr.sin_family = AF_INET;
servAdr.sin_addr.s_addr = inet_addr(argv[1]);
servAdr.sin_port = htons(atoi(argv[2]));
if(connect(hSocket, (SOCKADDR*)&servAdr, sizeof(servAdr)) == SOCKET_ERROR){
ErrorHandling("connect() error!");
}
else{
puts("Connected........");
}
fputs("Operand count: ", stdout);
scanf("%d", &opndCnt);
opmsg[0] = (char)opndCnt; // one byte
for(i = 0; i < opndCnt; i++){
printf("Operand %d: ", i + 1);
scanf("%d", (int*)&opmsg[i*OPSZ + 1]);
}
fgetc(stdin);
fputs("Operator: ", stdout);
scanf("%c", &opmsg[opndCnt * OPSZ + 1]); // one byte
send(hSocket, opmsg, opndCnt * OPSZ + 2, 0);
recv(hSocket, (char*)&result, RLT_SIZE, 0);
printf("Operation result: %d \n", result);
closesocket(hSocket);
WSACleanup();
return 0;
}
運(yùn)行結(jié)果:文章來(lái)源:http://www.zghlxwxcb.cn/news/detail-695575.html
文章來(lái)源地址http://www.zghlxwxcb.cn/news/detail-695575.html
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