xref: /freebsd/sys/netgraph/ng_hub.c (revision 2e3f49888ec8851bafb22011533217487764fdb0)
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 
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 static 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 static int
83 ng_hub_constructor(node_p node)
84 {
85 	priv_p priv;
86 
87 	/* Allocate and initialize private info */
88 	priv = malloc(sizeof(*priv), M_NETGRAPH_HUB, M_WAITOK | M_ZERO);
89 
90 	NG_NODE_SET_PRIVATE(node, priv);
91 	return (0);
92 }
93 
94 /*
95  * Receive a control message
96  */
97 static int
98 ng_hub_rcvmsg(node_p node, item_p item, hook_p lasthook)
99 {
100 	const priv_p priv = NG_NODE_PRIVATE(node);
101 	int error = 0;
102 	struct ng_mesg *msg;
103 
104 	NGI_GET_MSG(item, msg);
105 	if (msg->header.typecookie == NGM_HUB_COOKIE &&
106 	    msg->header.cmd == NGM_HUB_SET_PERSISTENT) {
107 		priv->persistent = 1;
108 	} else {
109 		error = EINVAL;
110 	}
111 
112 	NG_FREE_MSG(msg);
113 	return (error);
114 }
115 
116 static int
117 ng_hub_rcvdata(hook_p hook, item_p item)
118 {
119 	const node_p node = NG_HOOK_NODE(hook);
120 	int error = 0;
121 	hook_p hook2;
122 	struct mbuf * const m = NGI_M(item), *m2;
123 	int nhooks;
124 
125 	if ((nhooks = NG_NODE_NUMHOOKS(node)) == 1) {
126 		NG_FREE_ITEM(item);
127 		return (0);
128 	}
129 	LIST_FOREACH(hook2, &node->nd_hooks, hk_hooks) {
130 		if (hook2 == hook)
131 			continue;
132 		if (--nhooks == 1)
133 			NG_FWD_ITEM_HOOK(error, item, hook2);
134 		else {
135 			if ((m2 = m_dup(m, M_NOWAIT)) == NULL) {
136 				NG_FREE_ITEM(item);
137 				return (ENOBUFS);
138 			}
139 			NG_SEND_DATA_ONLY(error, hook2, m2);
140 			if (error)
141 				continue;	/* don't give up */
142 		}
143 	}
144 
145 	return (error);
146 }
147 
148 /*
149  * Shutdown node
150  */
151 static int
152 ng_hub_shutdown(node_p node)
153 {
154 	const priv_p priv = NG_NODE_PRIVATE(node);
155 
156 	free(priv, M_NETGRAPH_HUB);
157 	NG_NODE_SET_PRIVATE(node, NULL);
158 	NG_NODE_UNREF(node);
159 	return (0);
160 }
161 
162 static int
163 ng_hub_disconnect(hook_p hook)
164 {
165 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
166 
167 	if (NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0 &&
168 	    NG_NODE_IS_VALID(NG_HOOK_NODE(hook)) && !priv->persistent)
169 		ng_rmnode_self(NG_HOOK_NODE(hook));
170 	return (0);
171 }
172