获取外网IP（二）（未对返回做处理）

最新推荐文章于 2023-08-12 08:52:02 发布

lifan5

最新推荐文章于 2023-08-12 08:52:02 发布

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/*
 * getip.c
 *
 *  Created on: 2013-7-11
 *      Author: Administrator
 */

#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <sys/socket.h>
typedef enum {
	false, true
} bool;
int main() {
	bool flag;
	int sock;
	char **pptr = NULL;
	struct sockaddr_in destAddr;
	struct hostent *ptr = NULL;
	char destIP[128];
	char szBuffer[] =
			{
				"GET / HTTP/1.1\r\nUser-Agent: curl/7.19.7 (i486-pc-linux-gnu) libcurl/7.19.7 OpenSSL/0.9.8k zlib/1.2.3.3 libidn/1.15\r\nHost: ifconfig.me\r\nAccept: */*\r\n\r\n" };
	char res[1024] = {0};
	//初始化socket
	sock = socket(AF_INET, SOCK_STREAM, 0);
	if (-1 == sock) {
		perror("creat socket failed");
		exit(0);
	}

	bzero((void *) &destAddr, sizeof(destAddr));
	destAddr.sin_family = AF_INET;
	destAddr.sin_port = htons(80);
	//首先是获取www.ip138.com的IP地址http://city.ip138.com/ip2city.asp
	//ptr = gethostbyname("www.ip138.com");
	ptr = gethostbyname("ifconfig.me");
	if (NULL == ptr) {
		perror("gethostbyname error");
		exit(0);
	}
	//对于www.ip138.com的每个IP进行尝试连接，直到有一个连接成功为止，或者无法连接，则退出程序
	for (flag = false, pptr = ptr->h_addr_list; NULL != *pptr; ++pptr) {
		inet_ntop(ptr->h_addrtype, *pptr, destIP, sizeof(destIP));
		printf("addr:%s\n", destIP);
		destAddr.sin_addr.s_addr = inet_addr(destIP);
		if (-1 != connect(sock, (struct sockaddr *) &destAddr,
						sizeof(struct sockaddr))) {
			flag = true;
			break;
		}
	}

	if (false == flag) {
		perror("connect failed");
	}

	//发送获取IP的数据包给www.ip138.com
	if (strlen(szBuffer) != send(sock, szBuffer, strlen(szBuffer), 0)) {
		perror("send error");
		exit(0);
	}
	//接收数据包
	if (-1 == recv(sock, res, 1024, 0)) {
		perror("recv error");
		exit(0);
	}

	printf("res:\n%s\n", res);
	return 0;
}

函数执行的结果：

root@hj-desktop:/mnt/hgfs/share/program_test/testgetip# ./getip2
addr:133.242.129.236
res:
HTTP/1.1 200 OK
Date: Fri, 12 Jul 2013 07:56:38 GMT
Server: Apache
Vary: xxxxxxxxxxxxxxx
Connection: close
Transfer-Encoding: chunked
Content-Type: text/plain

d
112.4.139.21

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