SOURCE FILE: webserver.c
/* webserver.c */
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <cnaiapi.h>
#if defined(LINUX) || defined(SOLARIS)
#include <sys/time.h>
#endif
#define BUFFSIZE 256
#define SERVER_NAME "CNAI Demo Web Server"
#define ERROR_400 "<head></head><body><html><h1>Error 400</h1><p>Th\
e server couldn't understand your request.</html></body>\n"
#define ERROR_404 "<head></head><body><html><h1>Error 404</h1><p>Do\
cument not found.</html></body>\n"
#define HOME_PAGE "<head></head><body><html><h1>Welcome to the CNAI\
Demo Server</h1><p>Why not visit: <ul><li><a href=\"http://netbook.cs.pu\
rdue.edu\">Netbook Home Page</a><li><a href=\"http://www.comerbooks.com\"\
>Comer Books Home Page<a></ul></html></body>\n"
#define TIME_PAGE "<head></head><body><html><h1>The current date is\
: %s</h1></html></body>\n"
int recvln(connection, char *, int);
void send_head(connection, int, int);
/*-----------------------------------------------------------------------
*
* Program: webserver
* Purpose: serve hard-coded webpages to web clients
* Usage: webserver <appnum>
*
*-----------------------------------------------------------------------
*/
int
main(int argc, char *argv[])
{
connection conn;
int n;
char buff[BUFFSIZE], cmd[16], path[64], vers[16];
char *timestr;
#if defined(LINUX) || defined(SOLARIS)
struct timeval tv;
#elif defined(WIN32)
time_t tv;
#endif
if (argc != 2) {
(void) fprintf(stderr, "usage: %s <appnum>\n", argv[0]);
exit(1);
}
while(1) {
/* wait for contact from a client on specified appnum */
conn = await_contact((appnum) atoi(argv[1]));
if (conn < 0)
exit(1);
/* read and parse the request line */
n = recvln(conn, buff, BUFFSIZE);
sscanf(buff, "%s %s %s", cmd, path, vers);
/* skip all headers - read until we get \r\n alone */
while((n = recvln(conn, buff, BUFFSIZE)) > 0) {
if (n == 2 && buff[0] == '\r' && buff[1] == '\n')
break;
}
/* check for unexpected end of file */
if (n < 1) {
(void) send_eof(conn);
continue;
}
/* check for a request that we cannot understand */
if (strcmp(cmd, "GET") || (strcmp(vers, "HTTP/1.0") &&
strcmp(vers, "HTTP/1.1"))) {
send_head(conn, 400, strlen(ERROR_400));
(void) send(conn, ERROR_400, strlen(ERROR_400),0);
(void) send_eof(conn);
continue;
}
/* send the requested web page or a "not found" error */
if (strcmp(path, "/") == 0) {
send_head(conn, 200, strlen(HOME_PAGE));
(void) send(conn, HOME_PAGE, strlen(HOME_PAGE),0);
} else if (strcmp(path, "/time") == 0) {
#if defined(LINUX) || defined(SOLARIS)
gettimeofday(&tv, NULL);
timestr = ctime(&tv.tv_sec);
#elif defined(WIN32)
time(&tv);
timestr = ctime(&tv);
#endif
(void) sprintf(buff, TIME_PAGE, timestr);
send_head(conn, 200, strlen(buff));
(void) send(conn, buff, strlen(buff), 0);
} else { /* not found */
send_head(conn, 404, strlen(ERROR_404));
(void) send(conn, ERROR_404, strlen(ERROR_404),0);
}
(void) send_eof(conn);
}
}
/*-----------------------------------------------------------------------
* send_head - send an HTTP 1.0 header with given status and content-len
*-----------------------------------------------------------------------
*/
void
send_head(connection conn, int stat, int len)
{
char *statstr, buff[BUFFSIZE];
/* convert the status code to a string */
switch(stat) {
case 200:
statstr = "OK";
break;
case 400:
statstr = "Bad Request";
break;
case 404:
statstr = "Not Found";
break;
default:
statstr = "Unknown";
break;
}
/*
* send an HTTP/1.0 response with Server, Content-Length,
* and Content-Type headers.
*/
(void) sprintf(buff, "HTTP/1.0 %d %s\r\n", stat, statstr);
(void) send(conn, buff, strlen(buff), 0);
(void) sprintf(buff, "Server: %s\r\n", SERVER_NAME);
(void) send(conn, buff, strlen(buff), 0);
(void) sprintf(buff, "Content-Length: %d\r\n", len);
(void) send(conn, buff, strlen(buff), 0);
(void) sprintf(buff, "Content-Type: text/html\r\n");
(void) send(conn, buff, strlen(buff), 0);
(void) sprintf(buff, "\r\n");
(void) send(conn, buff, strlen(buff), 0);
}