xref: /freebsd/sys/netgraph/ng_hub.c (revision 3f0164abf32b9b761e0a2cb4bdca3a8b84f156d4)
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 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 
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_WAITOK | M_ZERO);
90 
91 	NG_NODE_SET_PRIVATE(node, priv);
92 	return (0);
93 }
94 
95 /*
96  * Receive a control message
97  */
98 static int
99 ng_hub_rcvmsg(node_p node, item_p item, hook_p lasthook)
100 {
101 	const priv_p priv = NG_NODE_PRIVATE(node);
102 	int error = 0;
103 	struct ng_mesg *msg;
104 
105 	NGI_GET_MSG(item, msg);
106 	if (msg->header.typecookie == NGM_HUB_COOKIE &&
107 	    msg->header.cmd == NGM_HUB_SET_PERSISTENT) {
108 		priv->persistent = 1;
109 	} else {
110 		error = EINVAL;
111 	}
112 
113 	NG_FREE_MSG(msg);
114 	return (error);
115 }
116 
117 static int
118 ng_hub_rcvdata(hook_p hook, item_p item)
119 {
120 	const node_p node = NG_HOOK_NODE(hook);
121 	int error = 0;
122 	hook_p hook2;
123 	struct mbuf * const m = NGI_M(item), *m2;
124 	int nhooks;
125 
126 	if ((nhooks = NG_NODE_NUMHOOKS(node)) == 1) {
127 		NG_FREE_ITEM(item);
128 		return (0);
129 	}
130 	LIST_FOREACH(hook2, &node->nd_hooks, hk_hooks) {
131 		if (hook2 == hook)
132 			continue;
133 		if (--nhooks == 1)
134 			NG_FWD_ITEM_HOOK(error, item, hook2);
135 		else {
136 			if ((m2 = m_dup(m, M_NOWAIT)) == NULL) {
137 				NG_FREE_ITEM(item);
138 				return (ENOBUFS);
139 			}
140 			NG_SEND_DATA_ONLY(error, hook2, m2);
141 			if (error)
142 				continue;	/* don't give up */
143 		}
144 	}
145 
146 	return (error);
147 }
148 
149 /*
150  * Shutdown node
151  */
152 static int
153 ng_hub_shutdown(node_p node)
154 {
155 	const priv_p priv = NG_NODE_PRIVATE(node);
156 
157 	free(priv, M_NETGRAPH_HUB);
158 	NG_NODE_SET_PRIVATE(node, NULL);
159 	NG_NODE_UNREF(node);
160 	return (0);
161 }
162 
163 static int
164 ng_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