xref: /dragonfly/sys/netgraph7/echo/ng_echo.c (revision 9278355d)
1 /*
2  * ng_echo.c
3  */
4 
5 /*-
6  * Copyright (c) 1996-1999 Whistle Communications, Inc.
7  * All rights reserved.
8  *
9  * Subject to the following obligations and disclaimer of warranty, use and
10  * redistribution of this software, in source or object code forms, with or
11  * without modifications are expressly permitted by Whistle Communications;
12  * provided, however, that:
13  * 1. Any and all reproductions of the source or object code must include the
14  *    copyright notice above and the following disclaimer of warranties; and
15  * 2. No rights are granted, in any manner or form, to use Whistle
16  *    Communications, Inc. trademarks, including the mark "WHISTLE
17  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
18  *    such appears in the above copyright notice or in the software.
19  *
20  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
21  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
22  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
23  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
24  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
25  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
26  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
27  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
28  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
29  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
30  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
31  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
32  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
36  * OF SUCH DAMAGE.
37  *
38  * Author: Julian Elisher <julian@freebsd.org>
39  *
40  * $FreeBSD: src/sys/netgraph/ng_echo.c,v 1.13 2005/04/15 10:14:00 glebius Exp $
41  * $DragonFly: src/sys/netgraph7/ng_echo.c,v 1.2 2008/06/26 23:05:35 dillon Exp $
42  * $Whistle: ng_echo.c,v 1.13 1999/11/01 09:24:51 julian Exp $
43  */
44 
45 /*
46  * Netgraph "echo" node
47  *
48  * This node simply bounces data and messages back to whence they came.
49  */
50 
51 #include <sys/param.h>
52 #include <sys/systm.h>
53 #include <sys/kernel.h>
54 #include <sys/malloc.h>
55 #include <sys/mbuf.h>
56 #include <netgraph7/ng_message.h>
57 #include <netgraph7/netgraph.h>
58 #include "ng_echo.h"
59 
60 /* Netgraph methods */
61 static ng_constructor_t	nge_cons;
62 static ng_rcvmsg_t	nge_rcvmsg;
63 static ng_rcvdata_t	nge_rcvdata;
64 static ng_disconnect_t	nge_disconnect;
65 
66 /* Netgraph type */
67 static struct ng_type typestruct = {
68 	.version =	NG_ABI_VERSION,
69 	.name =		NG_ECHO_NODE_TYPE,
70 	.constructor =	nge_cons,
71 	.rcvmsg =	nge_rcvmsg,
72 	.rcvdata =	nge_rcvdata,
73 	.disconnect =	nge_disconnect,
74 };
75 NETGRAPH_INIT(echo, &typestruct);
76 
77 static int
nge_cons(node_p node)78 nge_cons(node_p node)
79 {
80 	return (0);
81 }
82 
83 /*
84  * Receive control message. We just bounce it back as a reply.
85  */
86 static int
nge_rcvmsg(node_p node,item_p item,hook_p lasthook)87 nge_rcvmsg(node_p node, item_p item, hook_p lasthook)
88 {
89 	struct ng_mesg *msg;
90 	int error = 0;
91 
92 	NGI_GET_MSG(item, msg);
93 	msg->header.flags |= NGF_RESP;
94 	NG_RESPOND_MSG(error, node, item, msg);
95 	return (error);
96 }
97 
98 /*
99  * Receive data
100  */
101 static int
nge_rcvdata(hook_p hook,item_p item)102 nge_rcvdata(hook_p hook, item_p item)
103 {
104 	int error;
105 
106 	NG_FWD_ITEM_HOOK(error, item, hook);
107 	return (error);
108 }
109 
110 /*
111  * Removal of the last link destroys the nodeo
112  */
113 static int
nge_disconnect(hook_p hook)114 nge_disconnect(hook_p hook)
115 {
116 	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
117 	&& (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) {
118 		ng_rmnode_self(NG_HOOK_NODE(hook));
119 	}
120 	return (0);
121 }
122 
123