/*
* request.c: Does the bulk of the work for the web server.
*
* CS537 Students: You shouldn't need to modify many of these routines.
* You will just want to update the statistics appropriately.
* We would suggest placing your scheduling routines in a new file/module.
*
*/
#include "cs537.h"
#include "request.h"
/* simple gettimeofday() wrapper, returns time as a double */
double get_time(){
struct timeval tv;
if(gettimeofday(&tv, NULL)!=0) unix_error("gettimeofday failed.");
return (double) ((double)tv.tv_sec + ((double)tv.tv_usec / 1e6));
}
/* expresses a double (as generated by get_time()) in milliseconds */
int milli(double time){
return (int) (time * 1000);
}
void requestError(int fd, char *cause, char *errnum, char *shortmsg,
char *longmsg)
{
char buf[MAXLINE], body[MAXBUF];
printf("Request ERROR\n");
/* Create the body of the error message */
sprintf(body, "CS537 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
CS537 Web Server\r\n", body);
/* Write out the header information for this response */
sprintf(buf, "HTTP/1.0 %s %s\r\n", errnum, shortmsg);
Rio_writen(fd, buf, strlen(buf));
printf("%s", buf);
sprintf(buf, "Content-Type: text/html\r\n");
Rio_writen(fd, buf, strlen(buf));
printf("%s", buf);
sprintf(buf, "Content-Length: %d\r\n\r\n", (int) strlen(body));
Rio_writen(fd, buf, strlen(buf));
printf("%s", buf);
/* Write out the content */
Rio_writen(fd, body, strlen(body));
printf("%s", body);
}
/*
* Reads and discards everything up to an empty text line
*/
void requestReadhdrs(rio_t *rp)
{
char buf[MAXLINE];
Rio_readlineb(rp, buf, MAXLINE);
while (strcmp(buf, "\r\n")) {
Rio_readlineb(rp, buf, MAXLINE);
}
return;
}
/*
* Return 1 if static, 0 if dynamic content
* Calculates filename (and cgiargs, for dynamic) from uri
*/
int requestParseURI(char *uri, char *filename, char *cgiargs)
{
char *ptr;
if (!strstr(uri, "cgi")) {
/* Static content */
strcpy(cgiargs, "");
sprintf(filename, ".%s", uri);
if (uri[strlen(uri)-1] == '/') {
strcat(filename, "home.html");
}
return 1;
} else {
/* Dynamic content */
ptr = index(uri, '?');
if (ptr) {
strcpy(cgiargs, ptr+1);
*ptr = '\0';
} else {
strcpy(cgiargs, "");
}
sprintf(filename, ".%s", uri);
return 0;
}
}
/*
* Fills in the filetype given the filename
*/
void requestGetFiletype(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, "test/plain");
}
void requestServeDynamic(int fd, char *filename, char *cgiargs, struct request* req)
{
char buf[MAXLINE], *emptylist[] = {NULL};
/*
* The server does only a little bit of the header.
* The CGI script has to finish writing out the header.
*/
(req->handled_by->dynamic_count)++;
sprintf(buf, "HTTP/1.0 200 OK\r\n");
sprintf(buf, "%s Server: Tiny Web Server\r\n", buf);
/* CS537: Your statistics go here -- fill in the 0's with something useful! */
sprintf(buf, "%s Stat-req-arrival: %d\r\n", buf, milli(req->stat->arrival_relative));
sprintf(buf, "%s Stat-req-dispatch: %d\r\n", buf, milli(req->stat->dispatch));
sprintf(buf, "%s Stat-req-age: %d\r\n", buf, req->stat->age);
sprintf(buf, "%s Stat-thread-id: %d\r\n", buf, req->handled_by->int_id);
sprintf(buf, "%s Stat-thread-count: %d\r\n", buf, req->handled_by->static_count + req->handled_by->dynamic_count);
sprintf(buf, "%s Stat-thread-static: %d\r\n", buf, req->handled_by->static_count);
sprintf(buf, "%s Stat-thread-dynamic: %d\r\n", buf, req->handled_by->dynamic_count);
Rio_writen(fd, buf, strlen(buf));
if (Fork() == 0) {
/* Child process */
Setenv("QUERY_STRING", cgiargs, 1);
/* When the CGI process writes to stdout, it will instead go to the socket */
Dup2(fd, STDOUT_FILENO);
Execve(filename, emptylist, environ);
}
Wait(NULL);
}
void requestServeStatic(int fd, char *filename, int filesize, struct request * req)
{
int srcfd;
char *srcp, filetype[MAXLINE], buf[MAXBUF];
char tmp = 0;
int i;
requestGetFiletype(filename, filetype);
srcfd = Open(filename, O_RDONLY, 0);
/*
* Rather than call read() to read the file into memory,
* which would require that we allocate a buffer, we memory-map the
* file
*/
srcp = Mmap(0, filesize, PROT_READ, MAP_PRIVATE, srcfd, 0);
Close(srcfd);
/*
* The following code is only needed to help you time the "read" given
* that the file is memory-mapped.
* This code ensures that the memory-mapped file is brought into memory
* from disk.
*
* When you time this, you will see that the first time a client
* requests a file, the read is much slower than subsequent requests.
*/
double start_read = get_time();
for (i = 0; i < filesize; i++) {
tmp += *(srcp + i);
}
req->stat->read = get_time() - start_read;
(req->handled_by->static_count)++;
sprintf(buf, "HTTP/1.0 200 OK\r\n");
sprintf(buf, "%s Server: CS537 Web Server\r\n", buf);
/* CS537: Your statistics go here -- fill in the 0's with something useful! */
sprintf(buf, "%s Stat-req-arrival: %d\r\n", buf, milli(req->stat->arrival_relative));
sprintf(buf, "%s Stat-req-dispatch: %d\r\n", buf, milli(req->stat->dispatch));
sprintf(buf, "%s Stat-req-read: %d\r\n", buf, milli(req->stat->read));
sprintf(buf, "%s Stat-req-complete: %d\r\n", buf, milli(get_time() - req->stat->arrival));
sprintf(buf, "%s Stat-req-age: %d\r\n", buf, req->stat->age);
sprintf(buf, "%s Stat-thread-id: %d\r\n", buf, req->handled_by->int_id);
sprintf(buf, "%s Stat-thread-count: %d\r\n", buf, req->handled_by->static_count + req->handled_by->dynamic_count);
sprintf(buf, "%s Stat-thread-static: %d\r\n", buf, req->handled_by->static_count);
sprintf(buf, "%s Stat-thread-dynamic: %d\r\n", buf, req->handled_by->dynamic_count);
sprintf(buf, "%s Content-Length: %d\r\n", buf, filesize);
sprintf(buf, "%s Content-Type: %s\r\n\r\n", buf, filetype);
Rio_writen(fd, buf, strlen(buf));
/* Writes out to the client socket the memory-mapped file */
Rio_writen(fd, srcp, filesize);
Munmap(srcp, filesize);
}
/*
* CS537: As long as you have the right "fd", then you shouldn't need to
* change anything in here... But, instead of having main() call this routine,
* the worker threads should be calling this...
*/
void requestHandle(void * request)
{
struct request *req = (struct request*) request;
int is_static;
struct stat sbuf;
char method[MAXLINE], uri[MAXLINE], version[MAXLINE];
char filename[MAXLINE], cgiargs[MAXLINE];
rio_t rio = req->rio;
int fd = req->connfd;
sscanf(req->content, "%s %s %s", method, uri, version);
printf("%s %s %s\n", method, uri, version);
if (strcasecmp(method, "GET")) {
requestError(fd, method, "501", "Not Implemented",
"CS537 Server does not implement this method");
return;
}
requestReadhdrs(&rio);
is_static = requestParseURI(uri, filename, cgiargs);
if (stat(filename, &sbuf) < 0) {
requestError(fd, filename, "404", "Not found", "CS537 Server could not find this file");
return;
}
if (is_static) {
if (!(S_ISREG(sbuf.st_mode)) || !(S_IRUSR & sbuf.st_mode)) {
requestError(fd, filename, "403", "Forbidden", "CS537 Server could not read this file");
return;
}
requestServeStatic(fd, filename, sbuf.st_size, req);
} else {
if (!(S_ISREG(sbuf.st_mode)) || !(S_IXUSR & sbuf.st_mode)) {
requestError(fd, filename, "403", "Forbidden", "CS537 Server could not run this CGI program");
return;
}
requestServeDynamic(fd, filename, cgiargs, req);
}
}