FreeBSD/Linux Kernel Cross Reference
sys/kern/uipc_accf.c
1 /*
2 * Copyright (c) 2000 Paycounter, Inc.
3 * Author: Alfred Perlstein <alfred@paycounter.com>, <alfred@FreeBSD.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD: releng/5.3/sys/kern/uipc_accf.c 136588 2004-10-16 08:43:07Z cvs2svn $");
30
31 #define ACCEPT_FILTER_MOD
32
33 #include "opt_param.h"
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/domain.h>
37 #include <sys/kernel.h>
38 #include <sys/lock.h>
39 #include <sys/malloc.h>
40 #include <sys/mbuf.h>
41 #include <sys/module.h>
42 #include <sys/mutex.h>
43 #include <sys/protosw.h>
44 #include <sys/sysctl.h>
45 #include <sys/socket.h>
46 #include <sys/socketvar.h>
47 #include <sys/queue.h>
48
49 static struct mtx accept_filter_mtx;
50 MTX_SYSINIT(accept_filter, &accept_filter_mtx, "accept_filter_mtx",
51 MTX_DEF);
52 #define ACCEPT_FILTER_LOCK() mtx_lock(&accept_filter_mtx)
53 #define ACCEPT_FILTER_UNLOCK() mtx_unlock(&accept_filter_mtx)
54
55 static SLIST_HEAD(, accept_filter) accept_filtlsthd =
56 SLIST_HEAD_INITIALIZER(&accept_filtlsthd);
57
58 MALLOC_DEFINE(M_ACCF, "accf", "accept filter data");
59
60 static int unloadable = 0;
61
62 SYSCTL_DECL(_net_inet); /* XXX: some header should do this for me */
63 SYSCTL_NODE(_net_inet, OID_AUTO, accf, CTLFLAG_RW, 0, "Accept filters");
64 SYSCTL_INT(_net_inet_accf, OID_AUTO, unloadable, CTLFLAG_RW, &unloadable, 0,
65 "Allow unload of accept filters (not recommended)");
66
67 /*
68 * must be passed a malloc'd structure so we don't explode if the kld
69 * is unloaded, we leak the struct on deallocation to deal with this,
70 * but if a filter is loaded with the same name as a leaked one we re-use
71 * the entry.
72 */
73 int
74 accept_filt_add(struct accept_filter *filt)
75 {
76 struct accept_filter *p;
77
78 ACCEPT_FILTER_LOCK();
79 SLIST_FOREACH(p, &accept_filtlsthd, accf_next)
80 if (strcmp(p->accf_name, filt->accf_name) == 0) {
81 if (p->accf_callback != NULL) {
82 ACCEPT_FILTER_UNLOCK();
83 return (EEXIST);
84 } else {
85 p->accf_callback = filt->accf_callback;
86 ACCEPT_FILTER_UNLOCK();
87 FREE(filt, M_ACCF);
88 return (0);
89 }
90 }
91
92 if (p == NULL)
93 SLIST_INSERT_HEAD(&accept_filtlsthd, filt, accf_next);
94 ACCEPT_FILTER_UNLOCK();
95 return (0);
96 }
97
98 int
99 accept_filt_del(char *name)
100 {
101 struct accept_filter *p;
102
103 p = accept_filt_get(name);
104 if (p == NULL)
105 return (ENOENT);
106
107 p->accf_callback = NULL;
108 return (0);
109 }
110
111 struct accept_filter *
112 accept_filt_get(char *name)
113 {
114 struct accept_filter *p;
115
116 ACCEPT_FILTER_LOCK();
117 SLIST_FOREACH(p, &accept_filtlsthd, accf_next)
118 if (strcmp(p->accf_name, name) == 0)
119 break;
120 ACCEPT_FILTER_UNLOCK();
121
122 return (p);
123 }
124
125 int
126 accept_filt_generic_mod_event(module_t mod, int event, void *data)
127 {
128 struct accept_filter *p;
129 struct accept_filter *accfp = (struct accept_filter *) data;
130 int error;
131
132 switch (event) {
133 case MOD_LOAD:
134 MALLOC(p, struct accept_filter *, sizeof(*p), M_ACCF, M_WAITOK);
135 bcopy(accfp, p, sizeof(*p));
136 error = accept_filt_add(p);
137 break;
138
139 case MOD_UNLOAD:
140 /*
141 * Do not support unloading yet. we don't keep track of refcounts
142 * and unloading an accept filter callback and then having it called
143 * is a bad thing. A simple fix would be to track the refcount
144 * in the struct accept_filter.
145 */
146 if (unloadable != 0) {
147 error = accept_filt_del(accfp->accf_name);
148 } else
149 error = EOPNOTSUPP;
150 break;
151
152 case MOD_SHUTDOWN:
153 error = 0;
154 break;
155
156 default:
157 error = EOPNOTSUPP;
158 break;
159 }
160
161 return (error);
162 }
Cache object: 375e9a0c331c4f7a338c32a3fb566702
|