linux socket 运行错误
下面是我socket的服务器和客户端的程序，编译通过了，在执行服务器后返回了server socket name，然后运行客户端时出现错误：client connet: no route to host
我查了connect的错误类型，说是ICMP错误:不可路由(soft error)(目的地不可达)
我是在一台机器上即作服务器又做客户端 这个问题该如何解决呢。谢谢！！


///////server
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/select.h>

#define MAX_BUF_SIZE (1024)
static char buf[MAX_BUF_SIZE];

int display_address(const char *msg, struct sockaddr_in* p_sin)
{
if(p_sin-> sin_family != AF_INET)
{
fprintf(stderr, "Not an Internet socket.\n ");
return -1;
}
fprintf(stdout, "%s ==> address is: %s : %d\n ", msg, inet_ntoa(p_sin-> sin_addr), ntohs(p_sin-> sin_port));
return 0;
}

int main()
{
int sock, serv;
struct sockaddr_in sin;
int size;
fd_set set;

FD_ZERO(&set);

serv = socket(AF_INET, SOCK_STREAM, 0);
if (serv == -1)
{
perror( "server socket ");

return -1;
}

memset(&sin, 0, sizeof(sin));
sin.sin_family = AF_INET;
sin.sin_addr.s_addr = htonl(INADDR_ANY);
sin.sin_port = htons(1685);

if (bind(serv, (struct sockaddr *)&sin, sizeof(sin)) == -1)
{
perror( "server bind ");
return -1;
}

listen(serv, 5);

memset(&sin, 0, sizeof(sin));
size = sizeof(sin);
if (getsockname(serv, (struct sockaddr *)&sin, &size) == -1)
perror( "serv sockname ");
display_address( "server socket name ", &sin);
sock = accept(serv, NULL, NULL);

if (sock != -1)
{
memset(&sin, 0, sizeof(sin));
size = sizeof(sin);
if (getpeername(sock, (struct sockaddr *)&sin, &size) == -1)
perror( "sock peername ");
display_address( "sock peer name ", &sin);
memset(&sin, 0, sizeof(sin));
size = sizeof(sin);
if (getsockname(sock, (struct sockaddr *)&sin, &size))
perror( "sock sockname ");
display_address( "sock socket name ", &sin);

//sleep(1);
while(1)
{
FD_SET(sock, &set);
select(FD_SETSIZE, &set, NULL, NULL, NULL);
size = recv(sock, buf, MAX_BUF_SIZE, 0);
if (size <= 0)
break;
printf( "server recv %d bytes\n ", size);
}
}
//printf( "server recv %d bytes\n ", size);
close(serv);
close(sock);
}
////////client
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#define MAX_BUF_SIZE (300)
static char buf[MAX_BUF_SIZE] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 0};

int main()
{
int sock;
struct sockaddr_in sin;
int size;

sock = socket(AF_INET, SOCK_STREAM, 0);
if (sock == -1)
{
perror( "client socket ");
return -1;
}

memset(&sin, 0, sizeof(sin));
sin.sin_family = AF_INET;

sin.sin_addr.s_addr = inet_addr( "192.168.21.207 ");
sin.sin_port = htons(1685);

if (connect(sock, (struct sockaddr *)&sin, sizeof(sin)) == -1)
{
perror( "client connect ");
return -1;
}
size = 0;
if (sock != -1)
{
size += send(sock, buf, MAX_BUF_SIZE, 0);
size += send(sock, buf, MAX_BUF_SIZE, 0);
size += send(sock, buf, MAX_BUF_SIZE, 0);
size += send(sock, buf, MAX_BUF_SIZE, 0);
size += send(sock, buf, MAX_BUF_SIZE, 0);
}
printf( "client send %d bytes\n ", size);
close(sock);
}


[解决办法]
你的代码我看了, 没什么大错误, 不过看着象是从Linux C函数手册中抄袭的.
发现一个错误:
sin.sin_addr.s_addr = inet_addr( "192.168.21.207 ");
inet_addr()返回的是unsigned long类型, 而socketaddr_in结构的定义是:
struct socketaddr_in
{
unsigned short int sin_family;
uint16_t sin_port;
struct in_addr sin_addr;
unsigned char sin_zero[8];
};
可见, sin_addr类型是struct in_addr.
所以你要用:
int inet_aton(const char * cp,struct in_addr *inp);
来实现转换.
你试试先.