xref: /freebsd/sys/netgraph/ng_echo.c (revision a14a0223ae1b172e96dd2a1d849e22026a98b692)
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@whistle.com>
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/errno.h>
52 #include <sys/kernel.h>
53 #include <sys/malloc.h>
54 #include <sys/mbuf.h>
55 #include <sys/syslog.h>
56 #include <netgraph/ng_message.h>
57 #include <netgraph/netgraph.h>
58 #include <netgraph/ng_echo.h>
59 
60 /* Netgraph methods */
61 static ng_rcvmsg_t	nge_rcvmsg;
62 static ng_rcvdata_t	nge_rcvdata;
63 static ng_disconnect_t	nge_disconnect;
64 
65 /* Netgraph type */
66 static struct ng_type typestruct = {
67 	NG_VERSION,
68 	NG_ECHO_NODE_TYPE,
69 	NULL,
70 	NULL,
71 	nge_rcvmsg,
72 	NULL,
73 	NULL,
74 	NULL,
75 	NULL,
76 	nge_rcvdata,
77 	nge_rcvdata,
78 	nge_disconnect
79 };
80 NETGRAPH_INIT(echo, &typestruct);
81 
82 /*
83  * Receive control message. We just bounce it back as a reply.
84  */
85 static int
86 nge_rcvmsg(node_p node, struct ng_mesg *msg, const char *retaddr,
87 	   struct ng_mesg **rptr)
88 {
89 	if (rptr) {
90 		msg->header.flags |= NGF_RESP;
91 		*rptr = msg;
92 	} else {
93 		FREE(msg, M_NETGRAPH);
94 	}
95 	return (0);
96 }
97 
98 /*
99  * Receive data
100  */
101 static int
102 nge_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
103 {
104 	int error = 0;
105 
106 	NG_SEND_DATA(error, hook, m, meta);
107 	return (error);
108 }
109 
110 /*
111  * Removal of the last link destroys the nodeo
112  */
113 static int
114 nge_disconnect(hook_p hook)
115 {
116 	if (hook->node->numhooks == 0)
117 		ng_rmnode(hook->node);
118 	return (0);
119 }
120 
121