在实现服务器和客户端时,我发现客户端正在将内容写入stdout而不是通过网络。我发现connect()返回的文件描述符总是为零,这就解释了为什么它会写入stdout。但我无法弄清楚为什么connect()总是返回零而不是有效套接字。我找到的所有网上文章都是由于在connect()调用周围放置if()的优先级问题引起的。但我没有这样做,请帮忙解决。
服务器代码
客户端代码。
服务器代码
int setUpServer(struct fuzzerObj *ptr, int *firstClient)
{
/* Declarations */
int hostSocket, yes = 1, rtrn, clientfd;
union
{
struct sockaddr_in in;
}address;
/* Create Socket */
hostSocket = socket(AF_INET, SOCK_STREAM, 0);
if(hostSocket < 0)
{
errorHandler("Could not create socket\n", FUNCTION_ID_SET_UP_SERVER);
return -1;
}
/* Reuse Address */
rtrn = setsockopt(hostSocket, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes));
if(rtrn < 0)
{
errorHandler("Couldn't Reuse Address\n", FUNCTION_ID_SET_UP_SERVER);
return -1;
}
/* Set Up Struct */
address.in.sin_len = sizeof(address.in);
address.in.sin_family = AF_INET;
address.in.sin_port = htons(BBPORT_NUMBER);
address.in.sin_addr.s_addr = htonl(INADDR_ANY);
memset(address.in.sin_zero, 0, sizeof(address.in.sin_zero));
/* Bind Address to Socket */
rtrn = bind(hostSocket, (struct sockaddr*) &address, address.in.sin_len);
if(rtrn < 0)
{
errorHandler("Can't Bind Address to Socket\n", FUNCTION_ID_SET_UP_SERVER);
return -1;
}
/* listen */
rtrn = listen(hostSocket, ptr->numberOfClients);
if(rtrn < 0)
{
errorHandler("Can't Listen\n", FUNCTION_ID_SET_UP_SERVER);
return -1;
}
while(1)
{
rtrn = acceptClient(hostSocket, &clientfd);
if(rtrn < 0)
{
printf("Can't Accept Client\n");
return -1;
}
break;
}
*firstClient = clientfd;
return 0;
}
客户端代码。
#include <CoreFoundation/CoreFoundation.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <netinet/in.h>
#include <stdbool.h>
#include <sys/types.h>
#include <unistd.h>
#include <errno.h>
#define BLACKBOX_PORT 9696
int main(int argc, char *argv[])
{
/* Check To See If an argument was passed */
if(argc < 2)
{
printf("No enough Arguments\n");
return -1;
}
/* Declaration's */
const char *ip = argv[1];
int sockfd, fd, rtrn;
char *outBuf;
struct sockaddr_in servaddr;
/* Get Socket to Connect to Fuzz Server */
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if(sockfd < 0)
{
perror("Can't Create Socket");
return -1;
}
/* Fill Out Struct */
servaddr.sin_family = AF_INET;
servaddr.sin_port = htons(BLACKBOX_PORT);
inet_pton(AF_INET, ip, &servaddr.sin_addr);
/* Attempt Connection */
fd = connect(sockfd,(struct sockaddr *)&servaddr, sizeof(servaddr));
if(fd < 0)
{
perror("Can not connect to BlackBox Fuzz server");
return -1;
}
/* Allocate Space in Memory for Outgoing Connection */
rtrn = asprintf(&outBuf, "Mac OSX 10.9\n");
if(rtrn < 0)
{
perror("Copy Error");
return -1;
}
/* Send Data to Fuzzer via Socket */
rtrn = send(fd, outBuf, strlen(outBuf), 0);
if(rtrn < 0)
{
perror("Can't write Data to BlackBox Server");
return -1;
}
free(outBuf);
return 0;
}
accept()
使用未连接的绑定套接字来表示监听器。以这种方式使用套接字的副作用是给您提供了一个可轮询的句柄,以异步确定客户端是否正在尝试连接。然后,accept()
返回一个新的套接字来表示新建立的连接,使监听器套接字保持不变,以便它可以继续服务其目的。 - jxh