这是我的服务器/客户端套接字代码。 我有缓冲区问题,当客户端收到来自服务器的消息时,缓冲区(我将其初始化为" 12")输出显示如下:
[+]Client Socket is created.
[+]Connected to Server.
Temp :
12121212121212121212121212121212121212121212121212121212121212121212121212121212
12121212121212�L��Q�
服务器:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#define PORT 4444
int main(){
int sockfd, ret;
struct sockaddr_in serverAddr;
int clientSocket;
struct sockaddr_in newAddr;
socklen_t addr_size;
char buffer[1024];
char Temp[4]= "12";
pid_t childpid;
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if(sockfd < 0){
printf("[-]Error in connection.\n");
exit(1);
}
printf("[+]Server Socket is created.\n");
memset(&serverAddr, '\0', sizeof(serverAddr));
serverAddr.sin_family = AF_INET;
serverAddr.sin_port = htons(PORT);
serverAddr.sin_addr.s_addr = inet_addr("127.0.0.1");
ret = bind(sockfd, (struct sockaddr*)&serverAddr, sizeof(serverAddr));
if(ret < 0){
printf("[-]Error in binding.\n");
exit(1);
}
printf("[+]Bind to port %d\n", 4444);
if(listen(sockfd, 10) == 0){
printf("[+]Listening....\n");
}else{
printf("[-]Error in binding.\n");
}
while(1){
clientSocket = accept(sockfd, (struct sockaddr*)&newAddr, &addr_size);
if(clientSocket < 0){
exit(1);
}
printf("Connection accepted from %s:%d\n", inet_ntoa(newAddr.sin_addr),
ntohs(newAddr.sin_port));
if((childpid = fork()) == 0){
close(sockfd);
while(1){
send(clientSocket, Temp, strlen(Temp), 0);
bzero(buffer, sizeof(buffer));
if(strcmp(Temp, ":exit") == 0){
printf("Disconnected from %s:%d\n",
inet_ntoa(newAddr.sin_addr), ntohs(newAddr.sin_port));
break;
}
}
}
}
return 0;
}
客户:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#define PORT 4444
int main(){
int clientSocket, ret;
struct sockaddr_in serverAddr;
char buffer[1024];
char Temp[4];
clientSocket = socket(AF_INET, SOCK_STREAM, 0);
if(clientSocket < 0){
printf("[-]Error in connection.\n");
exit(1);
}
printf("[+]Client Socket is created.\n");
memset(&serverAddr, '\0', sizeof(serverAddr));
serverAddr.sin_family = AF_INET;
serverAddr.sin_port = htons(PORT);
serverAddr.sin_addr.s_addr = inet_addr("127.0.0.1");
ret = connect(clientSocket, (struct sockaddr*)&serverAddr,
sizeof(serverAddr));
if(ret < 0){
printf("[-]Error in connection.\n");
exit(1);
}
printf("[+]Connected to Server.\n");
bzero(buffer,512);
int words = 0;
char c;
while(1){
recv(clientSocket, Temp, 1024, 0);
if(recv(clientSocket, Temp, 1024, 0) < 0){
printf("[-]Error in receiving data.\n");
}
printf("Temp : %s \n",Temp);
if(strcmp(Temp, ":exit") == 0){
close(clientSocket);
printf("[-]Disconnected from server.\n");
} exit(1);
}
return 0;
}
拜托,任何人都可以告诉我如何解决这个问题,任何帮助都将不胜感激。
答案 0 :(得分:1)
我发现您的客户端代码有几个问题:
char Temp[4];
...
recv(clientSocket, Temp, 1024, 0);
尽管只为Temp
分配了4个字节,但您在这里读取的最多1024个字节为Temp
。如果读取超过4个字节,则其他数据结构将填充读取数据,即经典缓冲区溢出。
printf("Temp : %s \n",Temp);
这里假设Temp是一个\0
终止的字符串,它不是。因此,它会打印出数据,从&Temp
的位置开始,直到\0
字节,它会在某处找到(根据您的输出在Temp
之外的方式)。
if(strcmp(Temp, ":exit") == 0){
即使Temp
只有4个字节,此语句也假设至少6个字节(5个字节的字符串和\0
用于字符串标记的结尾)。
服务器代码也存在类似的问题。同样奇怪的是,您的buffer
变量已初始化,但从未使用过。我的猜测是你最初想用这个而不是Temp
来发送和接收。