當(dāng)前位置：首頁 > 编程资源 > 编程问答 >内容正文

编程问答

Tinyhttpd的实现和一些基本问题的解决

發(fā)布時間：2025/4/5 编程问答 12 豆豆

生活随笔收集整理的這篇文章主要介紹了 Tinyhttpd的实现和一些基本问题的解决小編覺得挺不錯的,現(xiàn)在分享給大家,幫大家做個參考.

TInyhttpd是一個簡單的http服務(wù)器的實現(xiàn)，代碼總共有500多行，但是讀下來對http的具體實現(xiàn)過程和linux網(wǎng)絡(luò)編程的學(xué)習(xí)都很有好處。我重寫了代碼，然后進行了詳細(xì)的注釋。注釋見詳細(xì)代碼。?
具體的可以用圖表示：?
?
代碼：

/*#!/usr/bin/env * ****************************************************** * Last modified: 2018-05-06 16:27 * Filename : tinyhttpd.c * Description : * ********************************************************/ #include<stdio.h> #include<sys/wait.h> #include<sys/socket.h> #include<netinet/in.h> #include<arpa/inet.h> #include<unistd.h> #include<sys/types.h> #include<stdlib.h> #include<errno.h> #include<string.h> #include<fcntl.h> #include<sys/stat.h> #include<sys/select.h> #include<ctype.h> #include<pthread.h> #include<stdint.h>#define ISspace(x) isspace((int)(x))#define SERVER_STRING "Server:jdbhttpd/0.1.0\r\n"#define STDIN 0 #define STDOUT 1 #define STDERR 2void execute_cgi(int ,const char *,const char *,const char *); void bad_requests(int ); void accept_request(void *); int startup(u_short *); void error_die(const char *); void unimplemented(int ); void not_found(int ); void serve_file(int,const char*); void headers(int,const char*); void cat(int,FILE*); void cannot_execute(int); int get_line(int,char*,int );void error_die(const char *sc) {perror(sc);exit(1); }void accept_request(void *arg) {int client = (intptr_t)arg;char buf[1024];size_t numchars;//保存請求方式char method[255];//保存請求urlchar url[255];//保存請求文件路徑char path[512];size_t i,j;struct stat st;//如果cgi=1 則執(zhí)行cgi程序int cgi = 0;char *query_string =NULL;numchars = get_line(client,buf,sizeof(buf));i = 0,j = 0;while(!ISspace(buf[i])&&(i<sizeof(method)-1)){//請求報文第一行就會說明請求方式，是否為GET或者POSTmethod[i] = buf[i];i++;}j = i;method[i] = '\0';//tinyhttpd只實現(xiàn)了GET和POSTif(strcasecmp(method,"GET")&&strcasecmp(method,"POST")){//tinyhttpd只實現(xiàn)了GET和POSTunimplemented(client);return;}if(strcasecmp(method,"POST")==0) cgi = 1;i = 0;//跨過空格while(ISspace(buf[j])&&(j<numchars)) j++;//得到請求的urlwhile(!ISspace(buf[j])&&(i<sizeof(url)-1)&&(j<numchars)){url[i] = buf[j];i++;j++;}url[i] = '\0';//對于GET請求，如果有攜帶參數(shù)，則query_string指針指向url中?后面的GET參數(shù)if(strcasecmp(method,"GET")==0){query_string = url;while((*query_string!='?')&&(*query_string!='\0'))query_string++;if(*query_string=='?'){cgi = 1;*query_string = '\0';query_string++;}}sprintf(path,"htdocs%s",url);//如果path是一個目錄,默認(rèn)設(shè)置為首頁index.htmlif(path[strlen(path)-1]=='/') strcat(path,"index.html");if(stat(path,&st)==-1){while((numchars>0)&&strcmp("\n",buf)) numchars = get_line(client,buf,sizeof(buf));not_found(client);}else{//如果為目錄if((st.st_mode&S_IFMT)==S_IFDIR) strcat(path,"/index.html");if((st.st_mode&S_IXUSR)||(st.st_mode&S_IXGRP)||(st.st_mode&S_IXOTH)) cgi = 1;//返回靜態(tài)文件if(!cgi) serve_file(client,path);elseexecute_cgi(client,path,method,query_string);}close(client); }void execute_cgi(int client,const char *path,const char *method,const char *query_string) {char buf[1024];int cgi_input[2];int cgi_output[2];pid_t pid;int status;int i;char c;int numchars = 1;int content_length = -1;buf[0] = 'A';buf[1] = '\0';//讀取并且舍棄頭部信息if(strcasecmp(method,"GET")==0){while((numchars>0)&&strcmp("\n",buf))numchars = get_line(client,buf,sizeof(buf));}else{numchars = get_line(client,buf,sizeof(buf));//15是因為Content-Length長度為15while((numchars>0)&&strcmp("\n",buf)){buf[15] = '\0';//求得Content-content_length的長度if(strcasecmp(buf,"Content-Length:")==0)content_length = atoi(&(buf[16]));numchars = get_line(client,buf,sizeof(buf));}if(content_length==-1){bad_requests(client);return;}}if(pipe(cgi_output)<0){cannot_execute(client);return;}if(pipe(cgi_input)<0){cannot_execute(client);return;}//fork一個子進程if((pid = fork())<0){cannot_execute(client);return;}sprintf(buf,"HTTP/1.0 200 OK\r\n");send(client,buf,strlen(buf),0);//子進程執(zhí)行cgi，并將輸出傳到cgi_output[1]if(pid==0){char meth_env[255];char query_env[255];char length_env[255];//對標(biāo)準(zhǔn)輸入和標(biāo)準(zhǔn)輸出進行重定向dup2(cgi_output[1],STDOUT);dup2(cgi_input[0],STDIN);close(cgi_output[0]);close(cgi_input[1]);sprintf(meth_env,"REQUEST_METHOD=%s",method);putenv(meth_env);if(strcasecmp(method,"GET")==0){sprintf(query_env,"QUERY_STRING=%s",query_string);putenv(query_env);}else{sprintf(length_env,"CONTENT_LENGTH=%d",content_length);putenv(length_env);}execl(path,path,NULL);exit(0);}//父進程傳輸數(shù)據(jù)和把數(shù)據(jù)發(fā)送到瀏覽器else{close(cgi_input[0]);close(cgi_output[1]);if(strcasecmp(method,"POST")==0){for(i = 0;i<content_length;i++){recv(client,&c,1,0);write(cgi_input[1],&c,1);}}while(read(cgi_output[0],&c,1)>0) send(client,&c,1,0);close(cgi_output[0]);close(cgi_input[1]);waitpid(pid,&status,0);} }void cannot_execute(int client) {char buf[1024];sprintf(buf,"HTTP/1.0 500 Internal Server Error\r\n");send(client,buf,sizeof(buf),0);sprintf(buf,"Content-type: text/html\r\n");send(client,buf,sizeof(buf),0);sprintf(buf,"\r\n");send(client,buf,sizeof(buf),0);sprintf(buf,"<P>Error prohibited CGI execution. \r\n ");send(client,buf,sizeof(buf),0); }void bad_requests(int client) {char buf[1024];sprintf(buf,"HTTP/1.0 400 BAD REQUEST\r\n");send(client,buf,sizeof(buf),0);sprintf(buf,"Content-type: text/html\r\n");send(client,buf,sizeof(buf),0);sprintf(buf,"\r\n");send(client,buf,sizeof(buf),0);sprintf(buf,"<P>your browser senta bad request, ");send(client,buf,sizeof(buf),0);sprintf(buf,"such as a POST without a Content-Length.\r\n");send(client,buf,sizeof(buf),0); }void headers(int client,const char* filename) {char buf[1024];(void)filename;strcpy(buf,"HTTP/1.0 200 OK\r\n");send(client,buf,strlen(buf),0);strcpy(buf,SERVER_STRING);send(client,buf,strlen(buf),0);sprintf(buf,"Content-Type: text/html\r\n");send(client,buf,strlen(buf),0);strcpy(buf,"\r\n");send(client,buf,strlen(buf),0); }void cat(int client,FILE *resource) {char buf[1024];fgets(buf,sizeof(buf),resource);while(!feof(resource)){send(client,buf,strlen(buf),0);fgets(buf,sizeof(buf),resource);} }void serve_file(int client,const char *filename) {FILE *resource = NULL;int numchars = 1;char buf[1024];buf[0] = 'A';buf[1] = '\0';while((numchars>0)&&strcmp("\n",buf)) numchars = get_line(client,buf,sizeof(buf));resource = fopen(filename,"r");if(resource==NULL) not_found(client);else{//添加http頭部headers(client,filename);//并發(fā)送文件內(nèi)容cat(client,resource);}fclose(resource); }void not_found(int client) {char buf[1024];sprintf(buf,"HTTP/1.0 404 NOT FOUND\r\n");send(client,buf,strlen(buf),0);sprintf(buf,SERVER_STRING);send(client,buf,strlen(buf),0);sprintf(buf,"Content-Type: text/html\r\n");send(client,buf,strlen(buf),0);sprintf(buf,"\r\n");send(client,buf,strlen(buf),0);sprintf(buf,"<HTML><TITLE>Not Found</TITLE>\r\n");send(client,buf,strlen(buf),0);sprintf(buf,"<BODY><P>The server could not fulfill\r\n");send(client,buf,strlen(buf),0);sprintf(buf,"your request because the resource specified\r\n");send(client,buf,strlen(buf),0);sprintf(buf,"is unavailable or nonexistent.\r\n");send(client,buf,strlen(buf),0);sprintf(buf,"</BODY></HTML>\r\n");send(client,buf,strlen(buf),0);}void unimplemented(int client) {char buf[1024];sprintf(buf,"HTTP/1.0 501 Method Not implemented\r\n");send(client,buf,strlen(buf),0);sprintf(buf,SERVER_STRING);send(client,buf,strlen(buf),0);sprintf(buf,"Content-Type: text/html\r\n");send(client,buf,strlen(buf),0);sprintf(buf,"\r\n");send(client,buf,strlen(buf),0);sprintf(buf,"<HTML><HEAD><TITLE>Method Not Implemented\r\n");send(client,buf,strlen(buf),0);sprintf(buf,"</TITLE></HEAD>\r\n");send(client,buf,strlen(buf),0);sprintf(buf,"<BODY><P>HTTP request method not supported. \r\n");send(client,buf,strlen(buf),0);sprintf(buf,"</BODY></HTML>\r\n");send(client,buf,strlen(buf),0); }//解析一行http報文 int get_line(int sock,char *buf,int size) {int i = 0;char c = '\0';int n;while((i<size-1)&&(c!='\n')){//先取一個字節(jié)n = recv(sock,&c,1,0);if(n>0){//因為請求報文末尾是以\r\n結(jié)束的if(c=='\r'){//偷窺一個字節(jié),判斷是否為\n,是則結(jié)束n = recv(sock,&c,1,MSG_PEEK);if(n>0&&(c=='\n')) recv(sock,&c,1,0);else c = '\n';}buf[i] = c;i++;}else c = '\n';}buf[i] = '\0';return i; }int startup(u_short *port) {int httpd = 0;int on = 1;struct sockaddr_in name;httpd = socket(PF_INET,SOCK_STREAM,0);//新建一個服務(wù)器端socketif(httpd == -1) error_die("socket");memset(&name,0,sizeof(name));//對socket的基本屬性進行賦值name.sin_family = AF_INET;name.sin_port = htons(*port); //htons從主機字節(jié)序轉(zhuǎn)換為網(wǎng)絡(luò)字節(jié)序name.sin_addr.s_addr = htonl(INADDR_ANY);//setsockopt原型 int setsockopt(int sockfd,int level,int optname,const void *optval,socklen_t optlen)if((setsockopt(httpd,SOL_SOCKET,SO_REUSEADDR,&on,sizeof(on)))<0)//{error_die("setsockopt failed");}//對端口進行綁定if(bind(httpd,(struct sockaddr*)&name,sizeof(name))<0) error_die("bind");//動態(tài)分配一個端口if(*port==0){socklen_t namelen = sizeof(name);if(getsockname(httpd,(struct sockaddr*)&name,&namelen)==-1){error_die("getsockname");}*port = ntohs(name.sin_port);}//對socket進行監(jiān)聽//5代表內(nèi)核維護一個隊列跟蹤這些完成的連接但服務(wù)器還沒有接受處理//或者正在進行的連接,代表大小的上限if(listen(httpd,5)<0) error_die("listen");else printf("listen success\n");return httpd; }int main(void) {int server_sock = -1;u_short port = 0;int client_sock = -1;struct sockaddr_in client_name;socklen_t client_name_len = sizeof(client_name);pthread_t newthread;//對服務(wù)器端口號進行綁定server_sock = startup(&port);printf("httpd running on the port %d\n",port);while(1){//接受來自客戶端的連接client_sock = accept(server_sock,(struct sockaddr *)&client_name,&client_name_len);if(client_sock==-1) error_die("accept");if(pthread_create(&newthread,NULL,(void*)accept_request,(void*)(intptr_t)client_sock)!=0) //每次收到請求，創(chuàng)建一個線程來處理接受到的請求，把client_sock轉(zhuǎn)成地址參數(shù)//傳入pthread_createperror("pthread_create");}//關(guān)掉服務(wù)器端socketclose(server_sock);return 0; }

然后寫命令./tinyhttpd執(zhí)行得到?
?
然后輸入紫色?
?
當(dāng)然在這個過程中有幾個問題：?
首先index.html的不能有執(zhí)行權(quán)限，還有后綴為.cgi的程序必須有執(zhí)行權(quán)限，可以使用chmod命令改變執(zhí)行權(quán)限。

然后使用wireshark對本地回環(huán)端口進行監(jiān)聽，然后追蹤tcp流。可以看到http的請求和應(yīng)答報文。

POST /color.cgi HTTP/1.1 Host: 127.0.0.1:36299 User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:60.0) Gecko/20100101 Firefox/60.0 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 Accept-Language: en-GB,en;q=0.5 Accept-Encoding: gzip, deflate Referer: http://127.0.0.1:36299/ Content-Type: application/x-www-form-urlencoded Content-Length: 10 Connection: keep-alive Upgrade-Insecure-Requests: 1color=pinkHTTP/1.0 200 OK HTTP/1.0 200 OK --------------10 Content-Type: text/html; charset=ISO-8859-1<!DOCTYPE htmlPUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" lang="en-US" xml:lang="en-US"> <head> <title>PINK</title> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" /> </head> <body bgcolor="pink"> <h1>This is pink</h1> </body> </html>

版權(quán)聲明：本文為博主原創(chuàng)文章，未經(jīng)博主允許不得轉(zhuǎn)載。 https://blog.csdn.net/u014303647/article/details/80231844

總結(jié)

以上是生活随笔為你收集整理的Tinyhttpd的实现和一些基本问题的解决的全部內(nèi)容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網(wǎng)站內(nèi)容還不錯，歡迎將生活随笔推薦給好友。

tinyhttpd

上一篇：嵌入式设备web服务器比较
下一篇： java list.add()与list