xref: /freebsd/sys/netgraph/ng_echo.c (revision 6b3455a7665208c366849f0b2b3bc916fb97516e)
1 
2 /*
3  * ng_echo.c
4  *
5  * Copyright (c) 1996-1999 Whistle Communications, Inc.
6  * All rights reserved.
7  *
8  * Subject to the following obligations and disclaimer of warranty, use and
9  * redistribution of this software, in source or object code forms, with or
10  * without modifications are expressly permitted by Whistle Communications;
11  * provided, however, that:
12  * 1. Any and all reproductions of the source or object code must include the
13  *    copyright notice above and the following disclaimer of warranties; and
14  * 2. No rights are granted, in any manner or form, to use Whistle
15  *    Communications, Inc. trademarks, including the mark "WHISTLE
16  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
17  *    such appears in the above copyright notice or in the software.
18  *
19  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
20  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
21  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
22  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
23  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
24  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
25  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
26  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
27  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
28  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
29  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
30  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
31  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
35  * OF SUCH DAMAGE.
36  *
37  * Author: Julian Elisher <julian@freebsd.org>
38  *
39  * $FreeBSD$
40  * $Whistle: ng_echo.c,v 1.13 1999/11/01 09:24:51 julian Exp $
41  */
42 
43 /*
44  * Netgraph "echo" node
45  *
46  * This node simply bounces data and messages back to whence they came.
47  */
48 
49 #include <sys/param.h>
50 #include <sys/systm.h>
51 #include <sys/kernel.h>
52 #include <sys/malloc.h>
53 #include <sys/mbuf.h>
54 #include <netgraph/ng_message.h>
55 #include <netgraph/netgraph.h>
56 #include <netgraph/ng_echo.h>
57 
58 /* Netgraph methods */
59 static ng_constructor_t	nge_cons;
60 static ng_rcvmsg_t	nge_rcvmsg;
61 static ng_rcvdata_t	nge_rcvdata;
62 static ng_disconnect_t	nge_disconnect;
63 
64 /* Netgraph type */
65 static struct ng_type typestruct = {
66 	.version =	NG_ABI_VERSION,
67 	.name =		NG_ECHO_NODE_TYPE,
68 	.constructor =	nge_cons,
69 	.rcvmsg =	nge_rcvmsg,
70 	.rcvdata =	nge_rcvdata,
71 	.disconnect =	nge_disconnect,
72 };
73 NETGRAPH_INIT(echo, &typestruct);
74 
75 static int
76 nge_cons(node_p node)
77 {
78 	return (0);
79 }
80 
81 /*
82  * Receive control message. We just bounce it back as a reply.
83  */
84 static int
85 nge_rcvmsg(node_p node, item_p item, hook_p lasthook)
86 {
87 	struct ng_mesg *msg;
88 	int error = 0;
89 
90 	NGI_GET_MSG(item, msg);
91 	msg->header.flags |= NGF_RESP;
92 	NG_RESPOND_MSG(error, node, item, msg);
93 	return (error);
94 }
95 
96 /*
97  * Receive data
98  */
99 static int
100 nge_rcvdata(hook_p hook, item_p item)
101 {
102 	int error = 0;
103 
104 	NG_FWD_ITEM_HOOK(error, item, hook);
105 	return (0);
106 }
107 
108 /*
109  * Removal of the last link destroys the nodeo
110  */
111 static int
112 nge_disconnect(hook_p hook)
113 {
114 	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
115 	&& (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) {
116 		ng_rmnode_self(NG_HOOK_NODE(hook));
117 	}
118 	return (0);
119 }
120 
121