xref: /freebsd/sys/netgraph/ng_hub.c (revision 5bf5ca772c6de2d53344a78cf461447cc322ccea)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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 
85 static int
86 ng_hub_constructor(node_p node)
87 {
88 	priv_p priv;
89 
90 	/* Allocate and initialize private info */
91 	priv = malloc(sizeof(*priv), M_NETGRAPH_HUB, M_WAITOK | M_ZERO);
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_NOWAIT)) == 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