1 /* net/uncork.c - Unstop a TCP socket from sending short writes.
2 * Copyright (C) 2001,2005 Bruce Guenter <bruce@untroubled.org>
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this library; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18 #include <sys/types.h>
19 #include <netinet/in.h>
20 #include <netinet/tcp.h>
21 #include <sys/socket.h>
22 #include <unistd.h>
23 #include "socket.h"
24
25 /** Unstop a TCP socket from sending short writes. */
socket_uncork(int sock)26 int socket_uncork(int sock)
27 {
28 #if defined(TCP_CORK)
29 int flag = 0;
30 return setsockopt(sock, SOL_TCP, TCP_CORK, &flag, sizeof flag) == 0;
31 #elif defined(TCP_NOPUSH)
32 /* BSD's TCP_NOPUSH option only takes effect after a write/send.
33 * Hopefully this extra write will cause the TCP stack to send out
34 * any buffered writes. */
35 int flag = 0;
36 if (setsockopt(sock, SOL_SOCKET, TCP_NOPUSH, &flag, sizeof flag) != 0) return 0;
37 return write(sock, &flag, 0) == 0;
38 #else
39 return 1;
40 #endif
41 }
42