xref: /freebsd/sys/netgraph/ng_hub.c (revision 76238846ad3e9e271a3d1f792f72beab727fd153)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2004 Ruslan Ermilov
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  * $FreeBSD$
29  */
30 
31 #include <sys/param.h>
32 #include <sys/errno.h>
33 #include <sys/kernel.h>
34 #include <sys/mbuf.h>
35 #include <sys/systm.h>
36 
37 #include <netgraph/ng_message.h>
38 #include <netgraph/ng_hub.h>
39 #include <netgraph/netgraph.h>
40 
41 #ifdef NG_SEPARATE_MALLOC
42 static MALLOC_DEFINE(M_NETGRAPH_HUB, "netgraph_hub", "netgraph hub node");
43 #else
44 #define M_NETGRAPH_HUB M_NETGRAPH
45 #endif
46 
47 /* Per-node private data */
48 struct ng_hub_private {
49 	int		persistent;	/* can exist w/o hooks */
50 };
51 typedef struct ng_hub_private *priv_p;
52 
53 /* Netgraph node methods */
54 static ng_constructor_t	ng_hub_constructor;
55 static ng_rcvmsg_t	ng_hub_rcvmsg;
56 static ng_shutdown_t	ng_hub_shutdown;
57 static ng_rcvdata_t	ng_hub_rcvdata;
58 static ng_disconnect_t	ng_hub_disconnect;
59 
60 /* List of commands and how to convert arguments to/from ASCII */
61 static const struct ng_cmdlist ng_hub_cmdlist[] = {
62 	{
63 		NGM_HUB_COOKIE,
64 		NGM_HUB_SET_PERSISTENT,
65 		"setpersistent",
66 		NULL,
67 		NULL
68 	},
69 	{ 0 }
70 };
71 
72 static struct ng_type ng_hub_typestruct = {
73 	.version =	NG_ABI_VERSION,
74 	.name =		NG_HUB_NODE_TYPE,
75 	.constructor =	ng_hub_constructor,
76 	.rcvmsg =	ng_hub_rcvmsg,
77 	.shutdown =	ng_hub_shutdown,
78 	.rcvdata =	ng_hub_rcvdata,
79 	.disconnect =	ng_hub_disconnect,
80 	.cmdlist =	ng_hub_cmdlist,
81 };
82 NETGRAPH_INIT(hub, &ng_hub_typestruct);
83 
84 static int
85 ng_hub_constructor(node_p node)
86 {
87 	priv_p priv;
88 
89 	/* Allocate and initialize private info */
90 	priv = malloc(sizeof(*priv), M_NETGRAPH_HUB, M_WAITOK | M_ZERO);
91 
92 	NG_NODE_SET_PRIVATE(node, priv);
93 	return (0);
94 }
95 
96 /*
97  * Receive a control message
98  */
99 static int
100 ng_hub_rcvmsg(node_p node, item_p item, hook_p lasthook)
101 {
102 	const priv_p priv = NG_NODE_PRIVATE(node);
103 	int error = 0;
104 	struct ng_mesg *msg;
105 
106 	NGI_GET_MSG(item, msg);
107 	if (msg->header.typecookie == NGM_HUB_COOKIE &&
108 	    msg->header.cmd == NGM_HUB_SET_PERSISTENT) {
109 		priv->persistent = 1;
110 	} else {
111 		error = EINVAL;
112 	}
113 
114 	NG_FREE_MSG(msg);
115 	return (error);
116 }
117 
118 static int
119 ng_hub_rcvdata(hook_p hook, item_p item)
120 {
121 	const node_p node = NG_HOOK_NODE(hook);
122 	int error = 0;
123 	hook_p hook2;
124 	struct mbuf * const m = NGI_M(item), *m2;
125 	int nhooks;
126 
127 	if ((nhooks = NG_NODE_NUMHOOKS(node)) == 1) {
128 		NG_FREE_ITEM(item);
129 		return (0);
130 	}
131 	LIST_FOREACH(hook2, &node->nd_hooks, hk_hooks) {
132 		if (hook2 == hook)
133 			continue;
134 		if (--nhooks == 1)
135 			NG_FWD_ITEM_HOOK(error, item, hook2);
136 		else {
137 			if ((m2 = m_dup(m, M_NOWAIT)) == NULL) {
138 				NG_FREE_ITEM(item);
139 				return (ENOBUFS);
140 			}
141 			NG_SEND_DATA_ONLY(error, hook2, m2);
142 			if (error)
143 				continue;	/* don't give up */
144 		}
145 	}
146 
147 	return (error);
148 }
149 
150 /*
151  * Shutdown node
152  */
153 static int
154 ng_hub_shutdown(node_p node)
155 {
156 	const priv_p priv = NG_NODE_PRIVATE(node);
157 
158 	free(priv, M_NETGRAPH_HUB);
159 	NG_NODE_SET_PRIVATE(node, NULL);
160 	NG_NODE_UNREF(node);
161 	return (0);
162 }
163 
164 static int
165 ng_hub_disconnect(hook_p hook)
166 {
167 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
168 
169 	if (NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0 &&
170 	    NG_NODE_IS_VALID(NG_HOOK_NODE(hook)) && !priv->persistent)
171 		ng_rmnode_self(NG_HOOK_NODE(hook));
172 	return (0);
173 }
174