accf_data.c revision 1.1 
1/*-
2 * Copyright (c) 2000 Alfred Perlstein <alfred@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__KERNEL_RCSID(0, "$NetBSD: accf_data.c,v 1.1 2008/08/04 03:55:47 tls Exp $");
29
30#define ACCEPT_FILTER_MOD
31
32#include <sys/param.h>
33#include <sys/kernel.h>
34#include <sys/lkm.h>
35#include <sys/sysctl.h>
36#include <sys/signalvar.h>
37#include <sys/socketvar.h>
38#include <netinet/accept_filter.h>
39
40/* accept filter that holds a socket until data arrives */
41
42static void	sohasdata(struct socket *so, void *arg, int waitflag);
43
44static struct accept_filter accf_data_filter = {
45	"dataready",
46	sohasdata,
47	NULL,
48	NULL,
49	{NULL,}
50};
51
52void accf_dataattach(int);
53void accf_dataattach(int num)
54{
55	accept_filt_generic_mod_event(NULL, LKM_E_LOAD, &accf_data_filter);
56}
57
58/*
59 * This code is to make DATA ready accept filer as LKM.
60 * To compile as LKM we need to move this set of code into
61 * another file and include this file for compilation when
62 * making LKM
63 */
64
65#ifdef _LKM
66static int accf_data_handle(struct lkm_table * lkmtp, int cmd);
67int accf_data_lkmentry(struct lkm_table * lkmtp, int cmd, int ver);
68
69MOD_MISC("accf_data");
70
71static int accf_data_handle(struct lkm_table * lkmtp, int cmd)
72{
73	return accept_filt_generic_mod_event(lkmtp, cmd, &accf_data_filter);
74}
75
76/*
77 * the module entry point.
78 */
79int
80accf_data_lkmentry(struct lkm_table *lkmtp, int cmd, int ver)
81{
82	DISPATCH(lkmtp, cmd, ver, accf_data_handle, accf_data_handle,
83	    accf_data_handle)
84}
85#endif
86
87static void
88sohasdata(struct socket *so, void *arg, int waitflag)
89{
90
91	if (!soreadable(so))
92		return;
93
94	so->so_upcall = NULL;
95	so->so_rcv.sb_flags &= ~SB_UPCALL;
96	soisconnected(so);
97	return;
98}
99