xref: /freebsd/sys/netgraph/ng_hub.c (revision 7a1c0d963366a31363d3705697a083dd8efee077)
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  * $FreeBSD$
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
40 MALLOC_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 */
46 struct ng_hub_private {
47 	int		persistent;	/* can exist w/o hooks */
48 };
49 typedef struct ng_hub_private *priv_p;
50 
51 /* Netgraph node methods */
52 static ng_constructor_t	ng_hub_constructor;
53 static ng_rcvmsg_t	ng_hub_rcvmsg;
54 static ng_shutdown_t	ng_hub_shutdown;
55 static ng_rcvdata_t	ng_hub_rcvdata;
56 static ng_disconnect_t	ng_hub_disconnect;
57 
58 /* List of commands and how to convert arguments to/from ASCII */
59 static 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 
70 static 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 };
80 NETGRAPH_INIT(hub, &ng_hub_typestruct);
81 
82 
83 static int
84 ng_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  */
100 static int
101 ng_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 
119 static int
120 ng_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  */
154 static int
155 ng_hub_shutdown(node_p node)
156 {
157 	const priv_p priv = NG_NODE_PRIVATE(node);
158 
159 	free(priv, M_NETGRAPH_HUB);
160 	NG_NODE_SET_PRIVATE(node, NULL);
161 	NG_NODE_UNREF(node);
162 	return (0);
163 }
164 
165 static int
166 ng_hub_disconnect(hook_p hook)
167 {
168 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
169 
170 	if (NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0 &&
171 	    NG_NODE_IS_VALID(NG_HOOK_NODE(hook)) && !priv->persistent)
172 		ng_rmnode_self(NG_HOOK_NODE(hook));
173 	return (0);
174 }
175