ng_hub.c revision 207680 
1/*-
2 * Copyright (c) 2004 Ruslan Ermilov
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 * $FreeBSD: head/sys/netgraph/ng_hub.c 207680 2010-05-05 22:06:05Z zec $
27 */
28
29#include <sys/param.h>
30#include <sys/errno.h>
31#include <sys/kernel.h>
32#include <sys/mbuf.h>
33#include <sys/systm.h>
34
35#include <netgraph/ng_message.h>
36#include <netgraph/ng_hub.h>
37#include <netgraph/netgraph.h>
38
39#ifdef NG_SEPARATE_MALLOC
40MALLOC_DEFINE(M_NETGRAPH_HUB, "netgraph_hub", "netgraph hub node");
41#else
42#define M_NETGRAPH_HUB M_NETGRAPH
43#endif
44
45/* Per-node private data */
46struct ng_hub_private {
47	int		persistent;	/* can exist w/o hooks */
48};
49typedef struct ng_hub_private *priv_p;
50
51/* Netgraph node methods */
52static ng_constructor_t	ng_hub_constructor;
53static ng_rcvmsg_t	ng_hub_rcvmsg;
54static ng_shutdown_t	ng_hub_shutdown;
55static ng_rcvdata_t	ng_hub_rcvdata;
56static ng_disconnect_t	ng_hub_disconnect;
57
58/* List of commands and how to convert arguments to/from ASCII */
59static const struct ng_cmdlist ng_hub_cmdlist[] = {
60	{
61		NGM_HUB_COOKIE,
62		NGM_HUB_SET_PERSISTENT,
63		"setpersistent",
64		NULL,
65		NULL
66	},
67	{ 0 }
68};
69
70static struct ng_type ng_hub_typestruct = {
71	.version =	NG_ABI_VERSION,
72	.name =		NG_HUB_NODE_TYPE,
73	.constructor =	ng_hub_constructor,
74	.rcvmsg =	ng_hub_rcvmsg,
75	.shutdown =	ng_hub_shutdown,
76	.rcvdata =	ng_hub_rcvdata,
77	.disconnect =	ng_hub_disconnect,
78	.cmdlist =	ng_hub_cmdlist,
79};
80NETGRAPH_INIT(hub, &ng_hub_typestruct);
81
82
83static int
84ng_hub_constructor(node_p node)
85{
86	priv_p priv;
87
88	/* Allocate and initialize private info */
89	priv = malloc(sizeof(*priv), M_NETGRAPH_HUB, M_NOWAIT | M_ZERO);
90	if (priv == NULL)
91		return (ENOMEM);
92
93	NG_NODE_SET_PRIVATE(node, priv);
94	return (0);
95}
96
97/*
98 * Receive a control message
99 */
100static int
101ng_hub_rcvmsg(node_p node, item_p item, hook_p lasthook)
102{
103	const priv_p priv = NG_NODE_PRIVATE(node);
104	int error = 0;
105	struct ng_mesg *msg;
106
107	NGI_GET_MSG(item, msg);
108	if (msg->header.typecookie == NGM_HUB_COOKIE &&
109	    msg->header.cmd == NGM_HUB_SET_PERSISTENT) {
110		priv->persistent = 1;
111	} else {
112		error = EINVAL;
113	}
114
115	NG_FREE_MSG(msg);
116	return (error);
117}
118
119static int
120ng_hub_rcvdata(hook_p hook, item_p item)
121{
122	const node_p node = NG_HOOK_NODE(hook);
123	int error = 0;
124	hook_p hook2;
125	struct mbuf * const m = NGI_M(item), *m2;
126	int nhooks;
127
128	if ((nhooks = NG_NODE_NUMHOOKS(node)) == 1) {
129		NG_FREE_ITEM(item);
130		return (0);
131	}
132	LIST_FOREACH(hook2, &node->nd_hooks, hk_hooks) {
133		if (hook2 == hook)
134			continue;
135		if (--nhooks == 1)
136			NG_FWD_ITEM_HOOK(error, item, hook2);
137		else {
138			if ((m2 = m_dup(m, M_DONTWAIT)) == NULL) {
139				NG_FREE_ITEM(item);
140				return (ENOBUFS);
141			}
142			NG_SEND_DATA_ONLY(error, hook2, m2);
143			if (error)
144				continue;	/* don't give up */
145		}
146	}
147
148	return (error);
149}
150
151/*
152 * Shutdown node
153 */
154static int
155ng_hub_shutdown(node_p node)
156{
157	const priv_p priv = NG_NODE_PRIVATE(node);
158
159	free(priv, M_NETGRAPH_HUB);
160	return (0);
161}
162
163static int
164ng_hub_disconnect(hook_p hook)
165{
166	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
167
168	if (NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0 &&
169	    NG_NODE_IS_VALID(NG_HOOK_NODE(hook)) && !priv->persistent)
170		ng_rmnode_self(NG_HOOK_NODE(hook));
171	return (0);
172}
173