initial commit

1 files changed, 967 insertions, 0 deletions

diff --git a/hittpd.c b/hittpd.c
new file mode 100644
index 0000000..73c7f73
--- /dev/null
+++ b/hittpd.c
@@ -0,0 +1,967 @@
+/* hittpd - efficient, no-frills HTTP 1.1 daemon */
+
+/* Copyright 2020 Leah Neukirchen <leah@vuxu.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#define TIMEOUT 60
+
+#define _XOPEN_SOURCE 700
+#define _DEFAULT_SOURCE
+
+#ifdef USE_SENDFILE
+#include <sys/sendfile.h>
+#endif
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <ctype.h>
+#include <dirent.h>
+#include <err.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <poll.h>
+#include <pwd.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "http_parser.h"
+
+struct conn_data {
+	enum { NONE, HOST, IMS, RANGE, OTHER, BAD_REQUEST, SENDING } state;
+	char *host;
+	char *ims;
+	char *path;
+	int fd;
+
+	/* state needed:
+	   - if serving file: fd, range and offset
+	   - if serving string: string, range and offset
+	 */
+
+	off_t off, first, last;
+	int stream_fd;
+	char *buf;
+
+	time_t deadline;
+};
+
+char mimetypes[] =
+    ":.html=text/html"
+    ":.htm=text/html"
+    ":.gif=image/gif"
+    ":.txt=text/plain";
+
+char default_mimetype[] = "text/plain";   // "application/octet-stream"
+
+char wwwroot[] = "/tmp";
+char default_vhost[] = "_default";
+
+int tilde = 0;
+int vhost = 0;
+
+static int
+on_url(http_parser *p, const char *s, size_t l)
+{
+	struct conn_data *data = p->data;
+
+	if (l == 0)
+		return 1;
+
+	char *path = malloc(l + 1);
+	if (!path)
+		return 1;
+
+	char *t = path;
+
+	// XXX move decoding below, to not show up in access log
+
+	for (size_t i = 0; i < l; i++) {
+		if (s[i] == '%') {
+			char c1 = s[i+1];
+
+			if (c1 >= '0' && c1 <= '9')
+				c1 = c1 - '0';
+			else if (c1 >= 'A' && c1 <= 'F')
+				c1 = c1 - 'A' + 10;
+			else if (c1 >= 'a' && c1 <= 'f')
+				c1 = c1 - 'a' + 10;
+			else {
+				data->state = BAD_REQUEST;
+				return 0;
+			}
+
+			char c2 = s[i+2];
+
+			if (c2 >= '0' && c2 <= '9')
+				c2 = c2 - '0';
+			else if (c2 >= 'A' && c2 <= 'F')
+				c2 = c2 - 'A' + 10;
+			else if (c2 >= 'a' && c2 <= 'f')
+				c2 = c2 - 'a' + 10;
+			else {
+				data->state = BAD_REQUEST;
+				return 0;
+			}
+
+			char d = (c1 << 4) | c2;
+
+			if (d == 0 || d == '/')
+				data->state = BAD_REQUEST;
+
+                        *t++ = d;
+			i += 2;
+		} else if (s[i] == 0) {
+			data->state = BAD_REQUEST;
+		} else {
+			*t++ = s[i];
+		}
+	}
+	*t = 0;
+
+	data->path = path;
+	return 0;
+}
+
+static int
+on_header_field(http_parser *p, const char *s, size_t l)
+{
+	struct conn_data *data = p->data;
+
+	if (data->state == BAD_REQUEST)
+		return 0;
+
+	if (l == 4 && strncasecmp(s, "host", l) == 0)
+		data->state = HOST;
+	else if (l == 17 && strncasecmp(s, "if-modified-since", l) == 0)
+		data->state = IMS;
+	else if (l == 5 && strncasecmp(s, "range", l) == 0)
+		data->state = RANGE;
+	else
+		data->state = OTHER;	// ignore others
+
+	return 0;
+}
+
+void
+parse_range(struct conn_data *data, const char *s, size_t l)
+{
+	long n;
+
+	if (sscanf(s, "bytes=%lu-%lu", &(data->first), &(data->last)) == 2) {
+		data->last++;                      // range counts inclusive
+		return;
+	} else if (sscanf(s, "bytes=-%lu", &n) == 1 && n > 0) {
+		data->first = -n;
+		data->last = -1;
+		return;
+	} else if (sscanf(s, "bytes=%lu-", &(data->first)) == 1 && s[l-1] == '-') {
+		data->last = -1;
+		return;
+	} else {
+		data->first = data->last = -666;
+	}
+}
+
+static int
+on_header_value(http_parser *p, const char *s, size_t l)
+{
+	struct conn_data *data = p->data;
+
+	if (data->state == HOST)
+		data->host = strndup(s, l);
+	else if (data->state == IMS)
+		data->ims = strndup(s, l);
+	else if (data->state == RANGE)
+		parse_range(data, s, l);
+
+	// ignore others
+
+	return 0;
+}
+
+void
+httpdate(time_t t, char *buf)
+{
+	strftime(buf, 64, "%a, %d %b %Y %H:%M:%S %Z", gmtime(&t));
+}
+
+static time_t
+parse_http_date(char *s)
+{
+        struct tm tm;
+
+	if (strlen(s) != 29)
+		return 0;
+
+        if (!strptime(s, "%a, %d %b %Y %T GMT", &tm))
+		return 0;
+
+        return timegm(&tm);
+}
+
+
+const char *
+peername(http_parser *p)
+{
+	struct conn_data *data = p->data;
+
+        struct sockaddr_storage ss;
+        socklen_t slen = sizeof ss;
+	static char addrbuf[NI_MAXHOST];
+
+        if (getpeername(data->fd, (struct sockaddr *)(void *)&ss, &slen) < 0)
+		return "0.0.0.0";
+	if (getnameinfo((struct sockaddr *)(void *)&ss, slen,
+	    addrbuf, sizeof addrbuf, 0, 0, NI_NUMERICHOST) < 0)
+		return "0.0.0.0";
+
+	if (strncmp("::ffff:", addrbuf, 7) == 0)
+		return addrbuf + 7;
+
+	return addrbuf;
+}
+
+void
+accesslog(http_parser *p, int status)
+{
+	struct conn_data *data = p->data;
+
+	char buf[64];
+	time_t t = time(0);
+	strftime(buf, 64, "[%d/%b/%Y:%H:%M:%S %z]", localtime(&t));
+
+//	REMOTEHOST - - [DD/MON/YYYY:HH:MM:SS -TZ] "METHOD PATH" STATUS BYTES
+// ?    REFERER USER_AGENT
+	printf("%s - - %s \"%s %s\" %d %ld\n",
+	    peername(p),
+	    buf,
+	    http_method_str(p->method),
+	    data->path,
+	    status,
+	    p->method == HTTP_HEAD ? 0 : data->last - data->first);
+}
+
+void
+send_dir_redirect(http_parser *p)
+{
+	struct conn_data *data = p->data;
+	char buf[512];
+
+	char now[64];
+	httpdate(time(0), now);
+
+	int len = snprintf(buf, sizeof buf,
+	    "HTTP/1.%d 301 Moved Permanently\r\n"
+	    "Content-Length: 0\r\n"
+	    "Date: %s\r\n"
+	    "Location: %s/\r\n"
+	    "\r\n",
+	    p->http_minor,
+	    now,
+	    data->path);
+
+	// XXX include redirect link?
+
+	write(data->fd, buf, len);
+	accesslog(p, 301);
+}
+
+void
+send_not_modified(http_parser *p, time_t modified)
+{
+	struct conn_data *data = p->data;
+	char buf[512];
+
+	char now[64], lastmod[64];
+	httpdate(time(0), now);
+	httpdate(modified, lastmod);
+
+	int len = snprintf(buf, sizeof buf,
+	    "HTTP/1.%d 304 Not Modified\r\n"
+	    "Date: %s\r\n"
+	    "Last-Modified: %s\r\n"
+	    "\r\n",
+	    p->http_minor,
+	    now,
+	    lastmod);
+
+	write(data->fd, buf, len);
+	accesslog(p, 304);
+}
+
+void
+send_error(http_parser *p, int status, const char *msg)
+{
+	struct conn_data *data = p->data;
+	char buf[512];
+
+	char now[64];
+	httpdate(time(0), now);
+
+	int len = snprintf(buf, sizeof buf,
+	    "HTTP/1.%d %d %s\r\n"
+	    "Content-Length: %ld\r\n"
+	    "Date: %s\r\n"
+	    "\r\n",
+	    p->http_minor,
+	    status, msg,
+	    4 + strlen(msg) + 2,
+	    now);
+
+	if (p->method != HTTP_HEAD)
+		len += snprintf(buf + len, sizeof buf - len,
+		    "%03d %s\r\n",
+		    status, msg);
+
+	write(data->fd, buf, len);
+	accesslog(p, status);
+}
+
+void
+send_rns(http_parser *p, off_t filesize)
+{
+	struct conn_data *data = p->data;
+	char buf[512];
+
+	char now[64];
+	httpdate(time(0), now);
+
+	int len = snprintf(buf, sizeof buf,
+	    "HTTP/1.%d 416 Requested Range Not Satisfiable\r\n"
+	    "Content-Length: 0\r\n"
+	    "Date: %s\r\n"
+	    "Content-Range: bytes */%ld\r\n"
+	    "\r\n",
+	    p->http_minor,
+	    now,
+	    filesize);
+
+	data->first = data->last = 0;
+
+	write(data->fd, buf, len);
+	accesslog(p, 416);
+}
+
+void
+print_urlencoded(FILE *stream, char *s)
+{
+	while (*s)
+		switch(*s) {
+		case ';':
+		case '/':
+		case '?':
+		case ':':
+		case '@':
+		case '=':
+		case '&':
+		case '"':
+		case '<':
+		case '>':
+		case '%':
+		escape:
+			fprintf(stream, "%%%02x", (unsigned char)*s++);
+			break;
+		default:
+			if (*s <= 32 || (unsigned char)*s >= 127)
+				goto escape;
+			fputc(*s++, stream);
+		}
+}
+
+void
+print_htmlencoded(FILE *stream, char *s)
+{
+	while (*s)
+		switch(*s) {
+		case '&':
+		case '"':
+		case '<':
+		case '>':
+			fprintf(stream, "&#x%x;", *s++);
+			break;
+		default:
+			fputc(*s++, stream);
+		}
+}
+
+void
+send_ok(http_parser *p, time_t modified, const char *mimetype, off_t filesize)
+{
+	struct conn_data *data = p->data;
+	char buf[512];
+
+	char now[64], lastmod[64];
+	httpdate(time(0), now);
+	httpdate(modified, lastmod);
+
+	int len;
+
+	if (data->first == 0 && data->last == filesize) {
+		len = snprintf(buf, sizeof buf,
+		    "HTTP/1.%d 200 OK\r\n"
+		    "Content-Type: %s\r\n"
+		    "Content-Length: %ld\r\n"
+		    "Last-Modified: %s\r\n"
+		    "Date: %s\r\n"
+		    "\r\n",
+		    p->http_minor,
+		    mimetype,
+		    data->last - data->first,
+		    lastmod,
+		    now);
+
+		write(data->fd, buf, len);
+		accesslog(p, 200);
+	} else {
+		len = snprintf(buf, sizeof buf,
+		    "HTTP/1.%d 206 Partial content\r\n"
+		    "Content-Type: %s\r\n"
+		    "Content-Length: %ld\r\n"
+		    "Last-Modified: %s\r\n"
+		    "Date: %s\r\n"
+		    "Content-Range: bytes %ld-%ld/%ld\r\n"
+		    "\r\n",
+		    p->http_minor,
+		    mimetype,
+		    data->last - data->first,
+		    lastmod,
+		    now,
+		    data->first, data->last - 1, filesize);
+
+		write(data->fd, buf, len);
+		accesslog(p, 206);
+	}
+}
+
+char *
+mimetype(char *ext)
+{
+	static char type[16];
+
+	if (!ext)
+		return default_mimetype;
+
+	char *x = strstr(mimetypes, ext);
+
+	if (x && x[-1] == ':' && x[strlen(ext)] == '=') {
+		char *t = type;
+		for (char *c = x + strlen(ext) + 1; *c && *c != ':'; )
+			*t++ = *c++;
+		*t = 0;
+		return type;
+	}
+
+	return default_mimetype;
+}
+
+static int
+on_message_complete(http_parser *p) {
+	struct conn_data *data = p->data;
+	printf("complete. host: %s path: %s\n", data->host, data->path);
+
+	if (data->state == BAD_REQUEST) {
+		data->state = SENDING;
+		send_error(p, 400, "Bad Request");
+		return 0;
+	}
+
+	data->state = SENDING;
+
+	if (!(p->method == HTTP_GET || p->method == HTTP_HEAD)) {
+		send_error(p, 405, "Method Not Allowed");
+		return 0;
+	}
+
+	if (data->path[0] != '/' || strstr(data->path, "/../")) {
+		send_error(p, 403, "Forbidden");
+		return 0;
+	}
+
+	char name[PATH_MAX];
+
+	if (tilde && data->path[1] == '~' && data->path[2]) {
+		char *e = strchr(data->path + 1, '/');
+		if (e)
+			*e = 0;
+
+		struct passwd *pw = getpwnam(data->path + 2);
+		if (!pw || pw->pw_uid < 1000) {
+			send_error(p, 404, "Not Found");
+			return 0;
+		}
+
+//		snprintf(name, sizeof name, "%s/tmp/%s",
+		snprintf(name, sizeof name, "%s/public_html/%s",
+		    pw->pw_dir, e ? e + 1 : "");
+
+		if (e)
+			*e = '/';
+	} else if (vhost) {
+		char *host = data->host;
+		if (!host) {
+			host = default_vhost;
+		} else {
+			char *s = host;
+			for (; *s && *s != ':' && *s != '/'; s++)
+				*s = tolower(*s);
+			*s = 0;
+		}
+		if (strstr(host, "..")) {
+			send_error(p, 403, "Forbidden");
+			return 0;
+		}
+
+		struct stat dst;
+		snprintf(name, sizeof name, "%s/%s", wwwroot, host);
+		if (stat(name, &dst) < 0 || !S_ISDIR(dst.st_mode))
+			host = default_vhost;
+
+		snprintf(name, sizeof name, "%s/%s%s",
+		    wwwroot, host, data->path);
+	} else {
+		snprintf(name, sizeof name, "%s%s",
+		    wwwroot, data->path);
+	}
+
+	int stream_fd = open(name, O_RDONLY);
+
+	if (stream_fd < 0) {
+		if (errno == EACCES || errno == EPERM)
+			send_error(p, 403, "Forbidden");
+		else if (errno == ENOENT || errno == ENOTDIR)
+			send_error(p, 404, "Not Found");
+		else {
+			perror("open");
+			send_error(p, 500, "Internal Server Error");
+		}
+		return 0;
+	}
+
+	struct stat st;
+	if (fstat(stream_fd, &st) < 0) {
+		send_error(p, 500, "Internal Server Error");
+		return 0;
+	}
+
+	if (S_ISDIR(st.st_mode)) {
+		int x;
+		if (data->path[strlen(data->path)-1] == '/' &&
+		    (x = openat(stream_fd, "index.html", O_RDONLY)) >= 0) {
+			close(stream_fd);
+			stream_fd = x;
+			if (fstat(stream_fd, &st) < 0) {
+				send_error(p, 500, "Internal Server Error");
+				return 0;
+			}
+			goto file;
+		}
+
+		close(stream_fd);
+		data->stream_fd = -1;
+
+		if (data->path[strlen(data->path)-1] != '/') {
+			send_dir_redirect(p);
+			return 0;
+		}
+
+		char *buf;
+		size_t len;
+
+		FILE *stream = open_memstream(&buf, &len);
+		if (!stream)
+			return 1;
+
+
+		fprintf(stream, "<!doctype html><meta charset=\"utf-8\">"
+		    "<title>Index of ");
+		print_htmlencoded(stream, data->path);
+		fprintf(stream, "</title>"
+		    "<h1>Index of ");
+		print_htmlencoded(stream, data->path);
+		fprintf(stream, "</h1>\n<ul>\n");
+
+		struct dirent **namelist;
+		int n = scandir(name, &namelist, 0, alphasort);
+
+		for (int i = 0; i < n; i++) {
+			if (namelist[i]->d_name[0] == '.' &&
+			    namelist[i]->d_name[1] == 0)
+				continue;
+
+			fprintf(stream, "<li><a href=\"");
+			print_urlencoded(stream, namelist[i]->d_name);
+			fprintf(stream, "%s\">",
+			    namelist[i]->d_type == DT_DIR ? "/" : "");
+			print_htmlencoded(stream, namelist[i]->d_name);
+			fprintf(stream, "%s</a></li>\n",
+			    namelist[i]->d_type == DT_DIR ? "/" : "");
+		}
+
+		while (n--)
+			free(namelist[n]);
+		free(namelist);
+
+		fprintf(stream, "</ul>\n");
+		fclose(stream);
+
+		data->buf = buf;
+		data->first = 0;
+		data->last = len;
+		send_ok(p, time(0), "text/html", len);
+
+		return 0;
+	}
+
+file:
+	if (data->ims) {
+		time_t t = parse_http_date(data->ims);
+		if (t >= st.st_mtime) {
+			send_not_modified(p, st.st_mtime);
+			return 0;
+		}
+	}
+
+	data->stream_fd = stream_fd;
+
+	char *ext = strrchr(data->path, '.');
+	if (ext && strchr(ext, '/'))
+		ext = 0;
+
+	if (data->first == -666 && data->last == -666) {
+		send_rns(p, st.st_size);
+		return 0;
+	}
+
+	if (data->first < 0)
+		data->first = st.st_size + data->first;
+	if (data->last == -1)
+		data->last = st.st_size;
+
+
+	if (data->first > data->last) {
+		send_rns(p, st.st_size);
+		return 0;
+	}
+
+	if (data->first < 0)
+		data->first = 0;
+	if (data->last > st.st_size)
+		data->last = st.st_size;
+
+	send_ok(p, st.st_mtime, mimetype(ext), st.st_size);
+
+	// XXX send short file directly?
+
+	return 0;
+}
+
+static http_parser_settings settings = {
+	.on_message_complete = on_message_complete,
+	.on_header_field = on_header_field,
+	.on_header_value = on_header_value,
+	.on_url = on_url,
+};
+
+#define OPEN_MAX 1024
+
+struct pollfd client[OPEN_MAX];
+struct http_parser parsers[OPEN_MAX];
+struct conn_data datas[OPEN_MAX];
+
+void
+close_connection(int i)
+{
+	if (client[i].fd >= 0)
+		close(client[i].fd);
+	client[i].fd = -1;
+
+	free(datas[i].buf);
+	free(datas[i].path);
+	free(datas[i].ims);
+	free(datas[i].host);
+
+	datas[i] = (struct conn_data){ 0 };
+}
+
+void
+finish_response(int i)
+{
+	if (datas[i].stream_fd >= 0)
+		close(datas[i].stream_fd);
+	datas[i].stream_fd = -1;
+
+	free(datas[i].buf);
+	free(datas[i].path);
+	free(datas[i].ims);
+	free(datas[i].host);
+
+	datas[i].buf = 0;
+	datas[i].path = 0;
+	datas[i].ims = 0;
+	datas[i].host = 0;
+
+	client[i].events = POLLRDNORM;
+
+	// HTTP 1.0 needs to close connection by server
+	// XXX unless explicit keep-alive is set
+	if (parsers[i].http_major == 1 && parsers[i].http_minor == 0)
+		close_connection(i);
+}
+
+void
+accept_client(int i, int fd)
+{
+	fcntl(fd, F_SETFL, O_NONBLOCK);
+
+	client[i].fd = fd;
+
+	http_parser_init(&parsers[i], HTTP_REQUEST);
+	datas[i] = (struct conn_data){ 0 };
+	datas[i].fd = fd;
+	datas[i].stream_fd = -1;
+	datas[i].last = -1;
+	datas[i].deadline = time(0) + TIMEOUT;
+
+	parsers[i].data = &datas[i];
+
+	client[i].events = POLLRDNORM;
+}
+
+void
+write_client(int i)
+{
+	struct conn_data *data = &datas[i];
+	int sockfd = client[i].fd;
+	ssize_t w = 0;
+
+	if (data->stream_fd >= 0) {
+#ifndef USE_SENDFILE
+		char buf[16*4096];
+		size_t n = pread(data->stream_fd, buf, sizeof buf, data->off);
+		if (n < 0)
+			; // XXX
+		else if (n == 0) {
+			finish_response(i);
+		} else if (n > 0) {
+			w = write(sockfd, buf, n);
+			if (w > 0)
+				data->off += w;
+		}
+#else
+		w = sendfile(sockfd, data->stream_fd,
+		    &(data->off), data->last - data->off);
+		if (w == 0 || data->off == data->last)
+			finish_response(i);
+#endif
+	} else if (data->buf) {
+		if (data->off == data->last) {
+			finish_response(i);
+		} else {
+			w = write(sockfd, data->buf, data->last - data->off);
+			if (w > 0)
+				data->off += w;
+		}
+	} else {
+		finish_response(i);
+		w = 0;
+	}
+
+	if (w < 0) {
+		if (errno == EPIPE)
+			close_connection(i);
+		// XXX other error handling
+	}
+}
+
+void
+read_client(int i)
+{
+	struct conn_data *data = &datas[i];
+	int sockfd = client[i].fd;
+	ssize_t n;
+	char buf[1024];
+
+	if ((n = read(sockfd, buf, sizeof buf)) < 0) {
+		if (errno == ECONNRESET) {
+			close_connection(i);
+		} else if (errno == EAGAIN) {
+			// try again
+		} else {
+			perror("read error");
+			close_connection(i);
+		}
+	} else if (n == 0) {
+		close_connection(i);
+	} else {
+		http_parser_execute(&parsers[i], &settings, buf, n);
+
+		if (parsers[i].http_errno) {
+			printf("err=%s\n",
+			    http_errno_name(parsers[i].http_errno));
+			close_connection(i);
+		} else {
+			// switch to write mode when needed
+			if (data->state == SENDING) {
+				client[i].events = POLLRDNORM | POLLWRNORM;
+				data->off = data->first;
+
+				if (parsers[i].method == HTTP_HEAD)
+					finish_response(i);
+			}
+		}
+
+	}
+}
+
+int
+main()
+{
+	int i, maxi, listenfd, sockfd;
+	int nready;
+	int r = 0;
+
+	signal(SIGPIPE, SIG_IGN);
+
+	struct sockaddr_in6 cliaddr, servaddr = { 0 };
+
+	listenfd = socket(AF_INET6, SOCK_STREAM, 0);
+	if (r < 0) {
+		perror("socket");
+		exit(111);
+	}
+
+	if (setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR,
+	    &(int){1}, sizeof (int)) < 0) {
+		perror("setsockopt(SO_REUSEADDR)");
+		exit(111);
+	}
+
+	servaddr.sin6_family = AF_INET6;
+	servaddr.sin6_port = htons(8081);
+	servaddr.sin6_addr = in6addr_any;
+
+	r = bind(listenfd, (struct sockaddr *)&servaddr, sizeof servaddr);
+	if (r < 0)
+	    perror("bind");
+
+	errno = 0;
+	r = listen(listenfd, 32);
+	if (r < 0)
+	    perror("listen");
+
+	client[0].fd = listenfd;
+	client[0].events = POLLRDNORM;
+
+	for (i = 1; i < OPEN_MAX; i++)
+		client[i].fd = -1;  /* -1 indicates available entry */
+
+	maxi = 0; /* max index into client[] array */
+
+	while (1) {
+		nready = poll(client, maxi + 1, maxi ? TIMEOUT*1000 : -1);
+
+		time_t now = time(0);
+
+		if (nready == 0) {
+			// clear timeouted
+			for (i = 1; i <= maxi; i++)
+				if (client[i].fd >= 0)
+					if (now > datas[i].deadline)
+						close_connection(i);
+
+			// compress
+			int i = 1, j = maxi;
+
+			while (i <= j) {
+				while (i <= maxi && client[i].fd >= 0)
+					i++;
+
+				if (i <= maxi) {
+					while (j >= 1 && client[i].fd == -1)
+						j--;
+
+					if (i < j) {
+						client[i] = client[j];
+						datas[i] = datas[j];
+						parsers[i] = parsers[j];
+						parsers[i].data = &datas[i];
+
+						client[j].fd = -1;
+
+						j--;
+					}
+				}
+			}
+
+			maxi = j;
+		}
+
+		if (client[0].revents & POLLRDNORM) {
+			/* new client connection */
+			for (i = 1; i < OPEN_MAX; i++)
+				if (client[i].fd < 0) {
+					socklen_t clilen = sizeof cliaddr;
+					int connfd = accept(listenfd,
+					    (struct sockaddr *)&cliaddr, &clilen);
+					accept_client(i, connfd);
+					break;
+				}
+			if (i == OPEN_MAX)
+				printf("too many clients\n");
+			if (i > maxi)
+				maxi = i; /* max index in client[] array */
+			if (--nready <= 0)
+				continue; /* no more readable descriptors */
+		}
+		for (i = 1; i <= maxi; i++) { /* check all clients for data */
+			if ((sockfd = client[i].fd) < 0)
+				continue;
+
+			if (client[i].revents & POLLWRNORM) {
+				if (datas[i].state != SENDING) {
+					client[i].events = POLLRDNORM;
+					continue;
+				}
+
+				write_client(i);
+				datas[i].deadline = now + TIMEOUT;
+
+				if (--nready <= 0)
+					break; /* no more readable descriptors */
+			}
+			else if (client[i].revents & (POLLRDNORM | POLLERR)) {
+				read_client(i);
+				datas[i].deadline = now + TIMEOUT;
+
+				if (--nready <= 0)
+					break; /* no more readable descriptors */
+			}
+		}
+	}
+}