bitreich-short

bitreich-httpd.c (4201B)

---

 /*
  * Copy me if you can.
  * by 20h
  */
 
 #include <errno.h>
 #include <unistd.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <time.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <string.h>
 #include <sys/socket.h>
 #include <netdb.h>
 
 #define WWWBASE "/var/cache/shorturl"
 #define CHARSET "abcdefghijklmnopqrstuvwxyz"
 #define NAMELEN 3
 
 char *host = "url.short";
 
 void *
 xmalloc(size_t size)
 {
 	void *p;
 
 	if (!(p = malloc(size))) {
 		perror("malloc");
 		exit(1);
 	}
 
 	return p;
 }
 
 char *
 randomname(int len)
 {
 	int i;
 	static char out[NAMELEN + 1];
 	static char charset[] = CHARSET;
 
 	srand((unsigned long)&i);
 	for (i = 0; i < len; i++)
 		out[i] = charset[rand() % (int)(sizeof(charset) -1)];
 
 	return out;
 }
 
 void
 print404(void)
 {
 	printf("HTTP/1.1 404 Google Broke The Web\r\n");
 	printf("\r\n");
 }
 
 void
 print500(void)
 {
 	printf("HTTP/1.1 500 You Broke The Web\r\n");
 	printf("\r\n");
 }
 
 void
 printheaders(char *ctype)
 {
 	time_t t;
 
 	t = time(NULL);
 	if (t > 0)
 		printf("Date: %s", asctime(gmtime(&t)));
 	printf("Content-Type: %s\r\n", ctype);
 	printf("Server: bitreich-httpd/2.0\r\n");
 	printf("Host: bitreich.org\r\n");
 	printf("Connection: close\r\n");
 }
 
 int
 servefile(char *path, char *ctype, int sock)
 {
 	struct stat st;
 	char *sendb, *sendi;
 	size_t bufsiz = BUFSIZ;
 	int len, sent, fd;
 
 	fd = open(path, O_RDONLY);
 	if (fd < 0) {
 		print404();
 		return 1;
 	}
 
 	printf("HTTP/1.1 200 OK\r\n");
 	printheaders(ctype);
 
 	if (fstat(fd, &st) >= 0)
 		if ((bufsiz = st.st_blksize) < BUFSIZ)
 			bufsiz = BUFSIZ;
 
 	printf("Content-Length: %ld\r\n", st.st_size);
 	printf("\r\n");
 	fflush(stdout);
 
 	sendb = xmalloc(bufsiz);
 	while ((len = read(fd, sendb, bufsiz)) > 0) {
 		sendi = sendb;
 		while (len > 0) {
 			if ((sent = write(sock, sendi, len)) < 0) {
 				free(sendb);
 				return 1;
 			}
 			len -= sent;
 			sendi += sent;
 		}
 	}
 	free(sendb);
 
 	return 0;
 }
 
 int
 redirect(char *path)
 {
 	struct stat st;
 	char *location;
 	size_t bufsiz = BUFSIZ;
 	int len, fd;
 
 	fd = open(path, O_RDONLY);
 	if (fd < 0) {
 		print404();
 		return 1;
 	}
 
 	if (fstat(fd, &st) >= 0)
 		if ((bufsiz = st.st_blksize) < BUFSIZ)
 			bufsiz = BUFSIZ;
 
 	location = xmalloc(bufsiz);
 	len = read(fd, location, bufsiz);
 
 	location[len - 1] = '\0';
 
 	printf("HTTP/1.1 307 Moved Temporarily\r\n");
 	printheaders("text/html");
 	printf("Location: %s\r\n", location);
 	printf("\r\n");
 
 	free(location);
 
 	return 0;
 }
 
 int
 saveurl(char *wwwbase, char *location)
 {
 	int fd;
 	char *path, *name, *url;
 
 	if (!(name = randomname(NAMELEN)))
 		return 1;
 
 	asprintf(&path, "%s/%s", wwwbase, name);
 	asprintf(&url, "http://%s/%s", host, name);
 
 	if ((fd = open(path, O_WRONLY|O_CREAT, 0644)) < 0)
 		return 1;
 
 	write(fd, location, strlen(location));
 	write(fd, "\n", 1);
 	close(fd);
 
 	printf("HTTP/1.1 200 OK\r\n");
 	printheaders("text/plain");
 	printf("Content-Length: %ld\r\n", strlen(url));
 	printf("\r\n");
 	fflush(stdout);
 	printf("%s", url);
 
 	free(path);
 	free(url);
 
 	return 0;
 }
 
 int
 main(int argc, char *argv[])
 {
 	char *wwwbase, request[512], *path, *url,
 	     clienth[NI_MAXHOST], clientp[NI_MAXSERV];
 	int rlen;
 	struct sockaddr_storage clt;
 	socklen_t cltlen = sizeof(clt);
 
 	wwwbase = WWWBASE;
 
 	if (!getpeername(0, (struct sockaddr *)&clt, &cltlen)) {
 		if (getnameinfo((struct sockaddr *)&clt, cltlen, clienth,
 					sizeof(clienth), clientp, sizeof(clientp),
 					NI_NUMERICHOST|NI_NUMERICSERV)) {
 			clienth[0] = clientp[0] = '\0';
 		}
 		if (!strncmp(clienth, "::ffff:", 7))
 			memmove(clienth, clienth+7, strlen(clienth)-6);
 	} else {
 			clienth[0] = clientp[0] = '\0';
 	}
 
 	rlen = read(0, request, sizeof(request)-1);
 	if (rlen < 0)
 		return 1;
 
 	request[rlen] = '\0';
 
 	if (!strncmp(request, "PUT ", 4)) {
 		url = strstr(request, "\r\n\r\n") + 4;
 		if (!url || !strlen(url) || saveurl(wwwbase, url)) {
 			perror(url);
 			print500();
 			return 1;
 		}
 		return 0;
 	} else if (!strncmp(request, "GET ", 4)) {
 		if (!strncmp(request + 4, "/ ", 2) || strstr(request, "/../")) {
 			print404();
 			return 1;
 		} else {
 			char *p = strstr(request + 4, " ");
 			*p = '\0';
 			asprintf(&path, "%s%s", wwwbase, request + 4);
 			rlen = redirect(path);
 			free(path);
 			return rlen;
 		}
 	}
 
 	return -1;
 }