Windows 和 Linux下使用socket下载网页页面内容（可设置接收/发送超时）的代码

主要难点在于设置recv()与send()的超时时间，具体要注意的事项，请看代码注释部分，下面是代码：
#include <stdio.h>
#include <sys/types.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <string.h>

#ifdef _WIN32 ///包含win socket相关头文件
#include <winsock.h>
#pragma comment(lib,"ws2_32.lib")
#else ///包含linux socket相关头文件
#include <unistd.h>
#include <strings.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <fcntl.h>
#include <stdint.h>
#endif

#ifdef _WIN32
#ifdef __cplusplus
extern "C"{
#endif

int strcasecmp(const char *s1, const char *s2)
{
while ((*s1 != '\0')
&& (tolower(*(unsigned char *) s1) ==
tolower(*(unsigned char *) s2)))
{
s1++;
s2++;
}
return tolower(*(unsigned char *) s1) - tolower(*(unsigned char *) s2);
}
int strncasecmp(const char *s1, const char *s2, unsigned int n)
{
if (n == 0)
return 0;
while ((n-- != 0)
&& (tolower(*(unsigned char *) s1) ==
tolower(*(unsigned char *) s2))) {
if (n == 0 || *s1 == '\0' || *s2 == '\0')
return 0;
s1++;
s2++;
}
return tolower(*(unsigned char *) s1) - tolower(*(unsigned char *) s2);
}
#ifdef __cplusplus
}
#endif

#endif
/**********************************
*功能:Base64编码
*参数:
src_data:待编码的字符串
coded_data:编码后的字符串
*返回值:-1,失败;0,成功
***********************************/
int base64encode(const char * src_data/*in,待编码的字符串*/,char * coded_data/*out,编码后的字符串*/)
{
const char EncodeTable[]="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
int src_data_len = strlen(src_data);
int i;
int lineLength=0;
int mod=src_data_len % 3;
unsigned char tmp[4]={0};
char buff[5]={0};
for(i=0;i<(int)(src_data_len / 3);i++)
{
tmp[1] = *src_data++;
tmp[2] = *src_data++;
tmp[3] = *src_data++;
sprintf(buff,"%c%c%c%c", EncodeTable[tmp[1] >> 2],EncodeTable[((tmp[1] << 4) | (tmp[2] >> 4)) & 0x3F],EncodeTable[((tmp[2] << 2) | (tmp[3] >> 6)) & 0x3F],EncodeTable[tmp[3] & 0x3F]);
strcat(coded_data,buff);
if(lineLength+=4,lineLength==76)
{
strcat(coded_data,"\r\n");
lineLength=0;
}
}
if(mod==1)
{
tmp[1] = *src_data++;
sprintf(buff,"%c%c==",EncodeTable[(tmp[1] & 0xFC) >> 2],EncodeTable[((tmp[1] & 0x03) << 4)]);
strcat(coded_data,buff);
}
else if(mod==2)
{
tmp[1] = *src_data++;
tmp[2] = *src_data++;
sprintf(buff,"%c%c%c=",EncodeTable[(tmp[1] & 0xFC) >> 2],EncodeTable[((tmp[1] & 0x03) << 4) | ((tmp[2] & 0xF0) >> 4)],EncodeTable[((tmp[2] & 0x0F) << 2)]);
strcat(coded_data,buff);
}
return 0;
}

//格式化http头,返回值:-1失败,-2用户名或密码无效;>=0 成功
int format_http_header(const char * webserverip,
unsigned short httpport/*web server 端口*/,
const char * url/*页面相对url,下载的页面为:http://ip/url"*/,
const char * username/*网站认证用户*/,
const char * password/*认证密码*/,
const char * ext_param/*访问网页附加参数*/,
int net_timeout/*超时时间,秒*/,
char header[512]/*out*/)
{
int len =0;
char buf_auth[100]={0},auth[100]={0};
sprintf(buf_auth,"%s:%s",username,password);
base64encode(buf_auth,auth);
if(ext_param)
{
len = strlen(ext_param);
}
if(len)
{
//GET
return sprintf(header,
"GET /%s?%s HTTP/1.1\r\n"
"Host:%s:%u\r\n"
"Content-Type: application/x-www-form-urlencoded\r\n"
"Keep-Alive: Keep-Alive: timeout=%d\r\n"
"Connection: keep-alive\r\n"
"Accept:text/html\r\n"
"Authorization: Basic %s\r\n"
"\r\n"
,url,ext_param,webserverip,httpport,net_timeout,auth
);
}
//GET
return sprintf(header,
"GET /%s HTTP/1.1\r\n"
"Host:%s:%u\r\n"
"Content-Type: application/x-www-form-urlencoded\r\n"
"Keep-Alive: timeout=%d\r\n"
"Connection: keep-alive\r\n"
"Accept:text/html\r\n"
"Authorization: Basic %s\r\n"
"\r\n"
,url,webserverip,httpport,net_timeout,auth
);
/*POST /login.php HTTP/1.1 必有字段
Host: www.webserver.com:80 必有字段
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN; rv:1.9) Gecko/2008052906 Firefox/3.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,**; q=.2\r\n"); 必有字段
Accept-Language: zh-cn,zh;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: gb2312,utf-8;q=0.7,*;q=0.7
Keep-Alive: 300
Connection: keep-alive
Referer: http://www.vckbase.com/ Cookie: ASPSESSIONIDCSAATTCD=DOMMILABJOPANJPNNAKAMCPK
Content-Type: application/x-www-form-urlencoded 必有字段
Content-Length: 79 post方式时必有字段*/

/*GET方式HTTP头写法*/
/*sprintf(header,
"GET /ipnc/php/ipnc.php?%s HTTP/1.1\r\n"
"Host:%s\r\n"
"Content-Type:application/x-www-form-urlencoded\r\n"
"Accept:text/html\r\n"
"\r\n"
,parm,serverip
);*/
}
int parse_response_http_header(const char * all_contents/*接收到的所有内容,包含http头*/,char ** contents/*返回自己需要的内容*/)
{
/**
*根据需求分析网页的内容
**/
return 0;
}
//分析返回的内容的长度
int parse_respose_contents_length(const char * header/*in,http头*/)
{
char * p = (char *)header;
int tmp = 0;
#if 1
if(p)
{
//获取内容长度
while(*p)
{
if(*p == '\r')
{
if(strncasecmp(p,"\r\n\r\n",4) != 0)//http头没有结束
{
p+=2;//过滤\n
if(strncasecmp(p,"Content-Length",14) == 0)
{
while(*p)
{
if(*p == ':')
{
p++;
tmp = atoi(p);
break;
}
p++;
}
break;
}
}
else
{
break;
}
}
p++;
}
if(!tmp)//没有Content-Length字段
{

for(p = (char*)header;*p;p++)
{
if(*p == '\r')
{
if(strncmp(p,"\r\n\r\n",4) == 0)
{
p+=4;
tmp = strlen(p);
break;
}
}
}
}
}
#endif
return tmp;
}

#define HTTP_RECV_BUFFER_SIZE 1024*1024*3 //3MB的接收缓存
#define RECV_BUFF_SIZE 1024

int download_web_page(const char * ipv4/*web server ip地址*/,
unsigned short httpport/*web server 端口*/,
const char * url/*页面相对url,下载的页面为:http://ip/url"*/,
const char * username/*网站认证用户*/,
const char * password/*认证密码*/,
const char * ext_param/*访问网页附加参数*/,
int net_timeout/*网络超时时间,秒*/,
char ** contents/*out:返回的实际内容,无http头,需要使用free函数手动释放空间*/
)
{
#ifdef _WIN32
WSADATA wsaData; //指向WinSocket信息结构的指针
#endif
struct sockaddr_in server_addr;
int sockfd = -1;
char szHttpHeader[1024]={0};
char * pszBuffer = NULL;///堆栈溢出，所以使用堆空间
char szRecvBuffer[RECV_BUFF_SIZE+1]={0};
int len = 0,total_recv_len=0,total_contents_len = 0,re=-1;
unsigned long flags;
fd_set fs;
char * pHttpHeaderEnd = NULL;
#ifdef _WIN32
/*
*这里请注意
*windows下设置接收/发送超时时间时，setsockopt函数对应的超时时间为int型（且超时时间的值的单位为毫秒，当时我直接填写为秒，老是接收超时）
*linux下为struct timeval结构
*/
int timeout = net_timeout*1000;
struct timeval select_timeout={0};
select_timeout.tv_sec=net_timeout;
#else
struct timeval timeout={.tv_sec=net_timeout,.tv_usec=0};
#endif

#ifdef _WIN32
if(WSAStartup(MAKEWORD( 1, 1 ), &wsaData )!=0)//进行WinSocket的初始化
{
WSACleanup();
return -1;//Can't initiates windows socket!初始化失败
}
#endif

if((sockfd = socket(AF_INET,SOCK_STREAM,0)) <= 0)
{
#if defined CONSOLE || defined LINUX
printf("创建socket失败.错误代码:%d,错误原因:%s\n",errno,strerror(errno));
#endif
return -1;//create socket fd failed
}
///设置接收超时时间
if(setsockopt(sockfd,SOL_SOCKET,SO_RCVTIMEO,(char *)&timeout,sizeof(timeout)) != 0)
{
#if defined CONSOLE || defined LINUX
printf("设置socket发送超时时间失败.错误代码:%d,错误原因:%s\n",errno,strerror(errno));
#endif
#ifdef _WIN32
closesocket(sockfd);
#else
close(sockfd);
#endif
return -1;
}
///设置发送超时时间
if(setsockopt(sockfd,SOL_SOCKET,SO_SNDTIMEO,(char *)&timeout,sizeof(timeout)) != 0)
{
#if defined CONSOLE || defined LINUX
printf("设置socket接收超时时间失败.错误代码:%d,错误原因:%s\n",errno,strerror(errno));
#endif
#ifdef _WIN32
closesocket(sockfd);
#else
close(sockfd);
#endif
return -1;
}
///设置非阻塞方式,使用select来判断connect是否超时
#ifdef _WIN32
flags=1;
if( ioctlsocket(sockfd,FIONBIO,&flags) != 0)
#else
flags=fcntl(sockfd,F_GETFL,0);
flags |= O_NONBLOCK;
if( fcntl(sockfd,F_SETFL,flags) != 0)
#endif
{
#if defined CONSOLE || defined LINUX
printf("设置socket为非阻塞失败.错误代码:%d,错误原因:%s\n",errno,strerror(errno));
#endif
#ifdef _WIN32
closesocket(sockfd);
#else
close(sockfd);
#endif
return -1;
}
///设置连接参数
#ifdef _WIN32
memset(&server_addr,0,sizeof(struct sockaddr_in));
#else
bzero(&server_addr,sizeof(struct sockaddr_in));
#endif
server_addr.sin_family = AF_INET;
server_addr.sin_port = htons(httpport);
server_addr.sin_addr.s_addr = inet_addr(ipv4);
///连接服务器
if( connect(sockfd,(struct sockaddr *)&server_addr,sizeof(struct sockaddr_in)) < 0)
{
int ret = 0;
///判断是否超时
FD_ZERO(&fs);
FD_SET(sockfd,&fs);
#ifdef _WIN32
ret = select(sockfd+1,NULL,&fs,NULL,&select_timeout);
#else
ret = select(sockfd+1,NULL,&fs,NULL,&timeout);
#endif
if(ret == 0)//超时
{
#if defined CONSOLE || defined LINUX
printf("链接服务器超时.错误代码:%d,错误原因:%s\n",errno,strerror(errno));
#endif
#ifdef _WIN32
closesocket(sockfd);
#else
close(sockfd);
#endif
return -1;//连接超时
}
else if(ret < 0)///错误
{
#if defined CONSOLE || defined LINUX
printf("链接服务器时发生错误.错误代码:%d,错误原因:%s\n",errno,strerror(errno));
#endif
#ifdef _WIN32
closesocket(sockfd);
#else
close(sockfd);
#endif
return -1;
}
}
///设置为阻塞方式发送和接收数据
#ifdef _WIN32
flags=0;
if( ioctlsocket(sockfd,FIONBIO,&flags) != 0)
#else
flags=fcntl(sockfd,F_GETFL,0);
flags &= ~O_NONBLOCK;
if( fcntl(sockfd,F_SETFL,flags) != 0)
#endif
{
#if defined CONSOLE || defined LINUX
printf("设置socket为阻塞失败.错误代码:%d,错误原因:%s\n",errno,strerror(errno));
#endif
#ifdef _WIN32
closesocket(sockfd);
#else
close(sockfd);
#endif
return -1;//ioctlsocket() error
}
format_http_header(ipv4,httpport,url,username,password,ext_param,net_timeout,szHttpHeader);

len = strlen(szHttpHeader);
///发送http头
if(send(sockfd,szHttpHeader,len,0) != len)
{
#if defined CONSOLE || defined LINUX
printf("发送http头失败.错误代码:%d,错误原因:%s\nhttp头:\n%s\n",errno,strerror(errno),szHttpHeader);
#endif
#ifdef _WIN32
closesocket(sockfd);
#else
close(sockfd);
#endif
return -1;//发送数据失败
}
///准备接收数据
pszBuffer = (char *)malloc(HTTP_RECV_BUFFER_SIZE);
if(!pszBuffer)
{
#if defined CONSOLE || defined LINUX
printf("内存分配失败\n");
#endif
#ifdef _WIN32
closesocket(sockfd);
#else
close(sockfd);
#endif
return -1;//outof memory
}

#ifdef _WIN32
memset(pszBuffer,0,HTTP_RECV_BUFFER_SIZE);
#else
bzero(pszBuffer,HTTP_RECV_BUFFER_SIZE);
#endif

while(1)
{
#ifdef _WIN32
len = recv(sockfd,szRecvBuffer,RECV_BUFF_SIZE,0);
#else
len = recv(sockfd,szRecvBuffer,RECV_BUFF_SIZE,MSG_WAITALL);
#endif
if(len == 0)
{
#if defined CONSOLE || defined LINUX
printf("接收数据超时,超时时间:%d s\n",net_timeout);
#endif
#ifdef _WIN32
closesocket(sockfd);
#else
close(sockfd);
#endif
free(pszBuffer);
return -1;//接收数据超时
}
if(len < 0 )
{
#if defined CONSOLE || defined LINUX
printf("接收数据错误,recv返回值:%d \n",len);
#endif
#ifdef _WIN32
closesocket(sockfd);
#else
close(sockfd);
#endif
free(pszBuffer);
return -1;//timeout
}
//printf("%s",szBuffer);
total_recv_len += len;
if(total_recv_len > (HTTP_RECV_BUFFER_SIZE-1) )
{
#if defined CONSOLE || defined LINUX
printf("接收数据buffer空间不足,当前buffer大小:%d B\n",HTTP_RECV_BUFFER_SIZE-1);
#endif
#ifdef _WIN32
closesocket(sockfd);
#else
close(sockfd);
#endif
free(pszBuffer);
return -1;//not enough buffer size
}
strcat(pszBuffer,szRecvBuffer);
if(len < RECV_BUFF_SIZE)
{
pHttpHeaderEnd = strstr(pszBuffer,"\r\n\r\n");
if(pHttpHeaderEnd )
{
if(!total_contents_len)///http返回头中标示的内容大小
{
total_contents_len = parse_respose_contents_length(pszBuffer);
}
pHttpHeaderEnd += 4;
//如果接收到的内容长度已经达到http返回头中标示的内容大小,停止接收
if( total_contents_len && strlen( pHttpHeaderEnd) >= total_contents_len )
break;
pHttpHeaderEnd = NULL;
}
}
#ifdef _WIN32
memset(szRecvBuffer,0,sizeof(szRecvBuffer));
#else
bzero(szRecvBuffer,sizeof(szRecvBuffer));
#endif
len = 0;
}
if(strcmp(pszBuffer,"") == 0)
{
#ifdef _WIN32
closesocket(sockfd);
#else
close(sockfd);
#endif
free(pszBuffer);
return -1;//recv data error
}
//printf("%s\n",szBuffer);
* contents = NULL;
re = parse_response_http_header(pszBuffer,contents);
if( re != 0 || !(*contents))
{
if(*contents)
{
free(*contents);
}
#if defined CONSOLE || defined LINUX
printf("分析服务器返回内容失败.返回内容为:\n%s\n",pszBuffer);
#endif
#ifdef _WIN32
closesocket(sockfd);
#else
close(sockfd);
#endif
free(pszBuffer);
if( -401 == re)
return -1;//用户名/密码无效
return -1;//unknown error
}
#ifdef _WIN32
closesocket(sockfd);
#else
close(sockfd);
#endif
free(pszBuffer);

#ifdef _WIN32
WSACleanup();
#endif
return 0;
}