/* $begin tinymain */ /* * tiny.c - A simple, iterative HTTP/1.0 Web server that uses the * GET method to serve static and dynamic content. */ #include "csapp.h" void doit(int fd); void read_requesthdrs(rio_t *rp); int parse_uri(char *uri, char *filename, char *cgiargs); void serve_static(int fd, char *filename, int filesize); void get_filetype(char *filename, char *filetype); void serve_dynamic(int fd, char *filename, char *cgiargs); void clienterror(int fd, char *cause, char *errnum, char *shortmsg, char *longmsg); int main(int argc, char **argv) { int listenfd, connfd, port, clientlen; struct sockaddr_in clientaddr; /* Check command line args */ if (argc != 2) { fprintf(stderr, "usage: %s \n", argv[0]); exit(1); } port = atoi(argv[1]); listenfd = Open_listenfd(port); while (1) { clientlen = sizeof(clientaddr); connfd = Accept(listenfd, (SA *)&clientaddr, &clientlen); //line:netp:tiny:accept doit(connfd); //line:netp:tiny:doit Close(connfd); //line:netp:tiny:close } } /* $end tinymain */ /* * doit - handle one HTTP request/response transaction */ /* $begin doit */ void doit(int fd) { int is_static; struct stat sbuf; char buf[MAXLINE], method[MAXLINE], uri[MAXLINE], version[MAXLINE]; char filename[MAXLINE], cgiargs[MAXLINE]; rio_t rio; /* Read request line and headers */ Rio_readinitb(&rio, fd); Rio_readlineb(&rio, buf, MAXLINE); //line:netp:doit:readrequest sscanf(buf, "%s %s %s", method, uri, version); //line:netp:doit:parserequest if (strcasecmp(method, "GET")) { //line:netp:doit:beginrequesterr clienterror(fd, method, "501", "Not Implemented", "Tiny does not implement this method"); return; } //line:netp:doit:endrequesterr read_requesthdrs(&rio); //line:netp:doit:readrequesthdrs /* Parse URI from GET request */ is_static = parse_uri(uri, filename, cgiargs); //line:netp:doit:staticcheck if (stat(filename, &sbuf) < 0) { //line:netp:doit:beginnotfound clienterror(fd, filename, "404", "Not found", "Tiny couldn't find this file"); return; } //line:netp:doit:endnotfound if (is_static) { /* Serve static content */ if (!(S_ISREG(sbuf.st_mode)) || !(S_IRUSR & sbuf.st_mode)) { //line:netp:doit:readable clienterror(fd, filename, "403", "Forbidden", "Tiny couldn't read the file"); return; } serve_static(fd, filename, sbuf.st_size); //line:netp:doit:servestatic } else { /* Serve dynamic content */ if (!(S_ISREG(sbuf.st_mode)) || !(S_IXUSR & sbuf.st_mode)) { //line:netp:doit:executable clienterror(fd, filename, "403", "Forbidden", "Tiny couldn't run the CGI program"); return; } serve_dynamic(fd, filename, cgiargs); //line:netp:doit:servedynamic } } /* $end doit */ /* * read_requesthdrs - read and parse HTTP request headers */ /* $begin read_requesthdrs */ void read_requesthdrs(rio_t *rp) { char buf[MAXLINE]; Rio_readlineb(rp, buf, MAXLINE); while(strcmp(buf, "\r\n")) { //line:netp:readhdrs:checkterm Rio_readlineb(rp, buf, MAXLINE); printf("%s", buf); } return; } /* $end read_requesthdrs */ /* * parse_uri - parse URI into filename and CGI args * return 0 if dynamic content, 1 if static */ /* $begin parse_uri */ int parse_uri(char *uri, char *filename, char *cgiargs) { char *ptr; if (!strstr(uri, "cgi-bin")) { /* Static content */ //line:netp:parseuri:isstatic strcpy(cgiargs, ""); //line:netp:parseuri:clearcgi strcpy(filename, "."); //line:netp:parseuri:beginconvert1 strcat(filename, uri); //line:netp:parseuri:endconvert1 if (uri[strlen(uri)-1] == '/') //line:netp:parseuri:slashcheck strcat(filename, "home.html"); //line:netp:parseuri:appenddefault return 1; } else { /* Dynamic content */ //line:netp:parseuri:isdynamic ptr = index(uri, '?'); //line:netp:parseuri:beginextract if (ptr) { strcpy(cgiargs, ptr+1); *ptr = '\0'; } else strcpy(cgiargs, ""); //line:netp:parseuri:endextract strcpy(filename, "."); //line:netp:parseuri:beginconvert2 strcat(filename, uri); //line:netp:parseuri:endconvert2 return 0; } } /* $end parse_uri */ /* * serve_static - copy a file back to the client */ /* $begin serve_static */ void serve_static(int fd, char *filename, int filesize) { int srcfd; char *srcp, filetype[MAXLINE], buf[MAXBUF]; /* Send response headers to client */ get_filetype(filename, filetype); //line:netp:servestatic:getfiletype sprintf(buf, "HTTP/1.0 200 OK\r\n"); //line:netp:servestatic:beginserve sprintf(buf, "%sServer: Tiny Web Server\r\n", buf); sprintf(buf, "%sContent-length: %d\r\n", buf, filesize); sprintf(buf, "%sContent-type: %s\r\n\r\n", buf, filetype); Rio_writen(fd, buf, strlen(buf)); //line:netp:servestatic:endserve /* Send response body to client */ srcfd = Open(filename, O_RDONLY, 0); //line:netp:servestatic:open srcp = Mmap(0, filesize, PROT_READ, MAP_PRIVATE, srcfd, 0);//line:netp:servestatic:mmap Close(srcfd); //line:netp:servestatic:close Rio_writen(fd, srcp, filesize); //line:netp:servestatic:write Munmap(srcp, filesize); //line:netp:servestatic:munmap } /* * get_filetype - derive file type from file name */ void get_filetype(char *filename, char *filetype) { if (strstr(filename, ".html")) strcpy(filetype, "text/html"); else if (strstr(filename, ".gif")) strcpy(filetype, "image/gif"); else if (strstr(filename, ".jpg")) strcpy(filetype, "image/jpeg"); else strcpy(filetype, "text/plain"); } /* $end serve_static */ /* * serve_dynamic - run a CGI program on behalf of the client */ /* $begin serve_dynamic */ void serve_dynamic(int fd, char *filename, char *cgiargs) { char buf[MAXLINE], *emptylist[] = { NULL }; /* Return first part of HTTP response */ sprintf(buf, "HTTP/1.0 200 OK\r\n"); Rio_writen(fd, buf, strlen(buf)); sprintf(buf, "Server: Tiny Web Server\r\n"); Rio_writen(fd, buf, strlen(buf)); if (Fork() == 0) { /* child */ //line:netp:servedynamic:fork /* Real server would set all CGI vars here */ setenv("QUERY_STRING", cgiargs, 1); //line:netp:servedynamic:setenv Dup2(fd, STDOUT_FILENO); /* Redirect stdout to client */ //line:netp:servedynamic:dup2 Execve(filename, emptylist, environ); /* Run CGI program */ //line:netp:servedynamic:execve } Wait(NULL); /* Parent waits for and reaps child */ //line:netp:servedynamic:wait } /* $end serve_dynamic */ /* * clienterror - returns an error message to the client */ /* $begin clienterror */ void clienterror(int fd, char *cause, char *errnum, char *shortmsg, char *longmsg) { char buf[MAXLINE], body[MAXBUF]; /* Build the HTTP response body */ sprintf(body, "Tiny Error"); sprintf(body, "%s\r\n", body); sprintf(body, "%s%s: %s\r\n", body, errnum, shortmsg); sprintf(body, "%s

%s: %s\r\n", body, longmsg, cause); sprintf(body, "%s


The Tiny Web server\r\n", body); /* Print the HTTP response */ sprintf(buf, "HTTP/1.0 %s %s\r\n", errnum, shortmsg); Rio_writen(fd, buf, strlen(buf)); sprintf(buf, "Content-type: text/html\r\n"); Rio_writen(fd, buf, strlen(buf)); sprintf(buf, "Content-length: %d\r\n\r\n", (int)strlen(body)); Rio_writen(fd, buf, strlen(buf)); Rio_writen(fd, body, strlen(body)); } /* $end clienterror */