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