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;
- }