web server shell.rar_c web server_linux_linux shell编程_web shell

/* twebserv.c - a threaded minimal web server (version 0.2) * usage: tws portnumber * features: supports the GET command only * runs in the current directory * creates a thread to handle each request * supports a special status URL to report internal state * building: cc twebserv.c socklib.c -lpthread -o twebserv */ #include <stdio.h> #include <sys/types.h> #include <sys/stat.h> #include <string.h> #include <pthread.h> #include <stdlib.h> #include <unistd.h> #include <dirent.h> #include <time.h> /* server facts here */ time_t server_started ; int server_bytes_sent; int server_requests; main(int ac, char *av[]) { int sock, fd; int *fdptr; pthread_t worker; pthread_attr_t attr; void *handle_call(void *); if ( ac == 1 ){ fprintf(stderr,"usage: tws portnum\n"); exit(1); } sock = make_server_socket( atoi(av[1]) ); if ( sock == -1 ) { perror("making socket"); exit(2); } setup(&attr); /* main loop here: take call, handle call in new thread */ while(1){ fd = accept( sock, NULL, NULL ); server_requests++; fdptr = malloc(sizeof(int)); *fdptr = fd; pthread_create(&worker,&attr,handle_call,fdptr); } } /* * initialize the status variables and * set the thread attribute to detached */ setup(pthread_attr_t *attrp) { pthread_attr_init(attrp); pthread_attr_setdetachstate(attrp,PTHREAD_CREATE_DETACHED); time(&server_started); server_requests = 0; server_bytes_sent = 0; } void *handle_call(void *fdptr) { FILE *fpin; char request[BUFSIZ]; int fd ; fd = *(int *)fdptr; free(fdptr); /* get fd from arg */ fpin = fdopen(fd, "r"); /* buffer input */ fgets(request,BUFSIZ,fpin); /* read client request */ printf("got a call on %d: request = %s", fd, request); skip_rest_of_header(fpin); process_rq(request, fd); /* process client rq */ fclose(fpin); } /* ------------------------------------------------------ * skip_rest_of_header(FILE *) skip over all request info until a CRNL is seen ------------------------------------------------------ */ skip_rest_of_header(FILE *fp) { char buf[BUFSIZ]; while( fgets(buf,BUFSIZ,fp) != NULL && strcmp(buf,"\r\n") != 0 ) ; } /* ------------------------------------------------------ * process_rq( char *rq, int fd ) do what the request asks for and write reply to fd handles request in a new process rq is HTTP command: GET /foo/bar.html HTTP/1.0 ------------------------------------------------------ */ process_rq( char *rq, int fd) { char cmd[BUFSIZ], arg[BUFSIZ]; if ( sscanf(rq, "%s%s", cmd, arg) != 2 ) return; sanitize(arg); printf("sanitized version is %s\n", arg); if ( strcmp(cmd,"GET") != 0 ) not_implemented(); else if ( built_in(arg, fd) ) ; else if ( not_exist( arg ) ) do_404(arg, fd); else if ( isadir( arg ) ) do_ls( arg, fd ); else do_cat( arg, fd ); } /* * make sure all paths are below the current directory */ sanitize(char *str) { char *src, *dest; src = dest = str; while( *src ){ if( strncmp(src,"/../",4) == 0 ) src += 3; else if ( strncmp(src,"//",2) == 0 ) src++; else *dest++ = *src++; } *dest = '\0'; if ( *str == '/' ) strcpy(str,str+1); if ( str[0]=='\0' || strcmp(str,"./")==0 || strcmp(str,"./..")==0 ) strcpy(str,"."); } /* handle built-in URLs here. Only one so far is "status" */ built_in(char *arg, int fd) { FILE *fp; if ( strcmp(arg,"status") != 0 ) return 0; http_reply(fd, &fp, 200, "OK", "text/plain",NULL); fprintf(fp,"Server started: %s", ctime(&server_started)); fprintf(fp,"Total requests: %d\n", server_requests); fprintf(fp,"Bytes sent out: %d\n", server_bytes_sent); fclose(fp); return 1; } http_reply(int fd, FILE **fpp, int code, char *msg, char *type, char *content) { FILE *fp = fdopen(fd, "w"); int bytes = 0; if ( fp != NULL ){ bytes = fprintf(fp,"HTTP/1.0 %d %s\r\n", code, msg); bytes += fprintf(fp,"Content-type: %s\r\n\r\n", type); if ( content ) bytes += fprintf(fp,"%s\r\n", content); } fflush(fp); if ( fpp ) *fpp = fp; else fclose(fp); return bytes; } /* ------------------------------------------------------ * simple functions first: not_implemented(fd) unimplemented HTTP command and do_404(item,fd) no such object ------------------------------------------------------ */ not_implemented(int fd) { http_reply(fd,NULL,501,"Not Implemented","text/plain", "That command is not implemented"); } do_404(char *item, int fd) { http_reply(fd,NULL,404,"Not Found","text/plain", "The item you seek is not here"); } /* ------------------------------------------------------ * the directory listing section isadir() uses stat, not_exist() uses stat ------------------------------------------------------ */ isadir(char *f) { struct stat info; return ( stat(f, &info) != -1 && S_ISDIR(info.st_mode) ); } not_exist(char *f) { struct stat info; return( stat(f,&info) == -1 ); } do_ls(char *dir, int fd) { DIR *dirptr; struct dirent *direntp; FILE *fp; int bytes = 0; bytes = http_reply(fd,&fp,200,"OK","text/plain",NULL); bytes += fprintf(fp,"Listing of Directory %s\n", dir); if ( (dirptr = opendir(dir)) != NULL ){ while( direntp = readdir(dirptr) ){ bytes += fprintf(fp, "%s\n", direntp->d_name); } closedir(dirptr); } fclose(fp); server_bytes_sent += bytes; } /* ------------------------------------------------------ * functions to cat files here. file_type(filename) returns the 'extension': cat uses it ------------------------------------------------------ */ char * file_type(char *f) { char *cp; if ( (cp = strrchr(f, '.' )) != NULL ) return cp+1; return ""; } /* do_cat(filename,fd): sends header then the contents */ do_cat(char *f, int fd) { char *extension = file_type(f); char *type = "text/plain"; FILE *fpsock, *fpfile; int c; int bytes = 0; if ( strcmp(extension,"html") == 0 ) type = "text/html"; else if ( strcmp(extension, "gif") == 0 ) type = "image/gif"; else if ( strcmp(extension, "jpg") == 0 ) type = "image/jpeg"; else if ( strcmp(extension, "jpeg") == 0 ) type = "image/jpeg"; fpsock = fdopen(fd, "w"); fpfile = fopen( f , "r"); if ( fpsock != NULL && fpfile != NULL ) { bytes = http_reply(fd,&fpsock,200,"OK",type,NULL); while( (c = getc(fpfile) ) != EOF ){ putc(c, fpsock); bytes++; } fclose(fpfile); fclose(fpsock); } server_bytes_sent += bytes; }