1/*
2 * ng_ether_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 * $Whistle: ng_echo.c,v 1.13 1999/11/01 09:24:51 julian Exp $
40 */
41
42/*
43 * Netgraph "ether_echo" node
44 *
45 * This node simply bounces data and messages back to whence they came.
46 * However it swaps the source and destination ether fields.
47 * No testing is done!
48 */
49
50#include <sys/param.h>
51#include <sys/systm.h>
52#include <sys/kernel.h>
53#include <sys/malloc.h>
54#include <sys/mbuf.h>
55#include <netgraph/ng_message.h>
56#include <netgraph/netgraph.h>
57#include <netgraph/ng_ether_echo.h>
58
59#include <net/ethernet.h>
60
61/* Netgraph methods */
62static ng_constructor_t	ngee_cons;
63static ng_rcvmsg_t	ngee_rcvmsg;
64static ng_rcvdata_t	ngee_rcvdata;
65static ng_disconnect_t	ngee_disconnect;
66
67/* Netgraph type */
68static struct ng_type typestruct = {
69	.version =	NG_ABI_VERSION,
70	.name =		NG_ETHER_ECHO_NODE_TYPE,
71	.constructor =	ngee_cons,
72	.rcvmsg =	ngee_rcvmsg,
73	.rcvdata =	ngee_rcvdata,
74	.disconnect =	ngee_disconnect,
75};
76NETGRAPH_INIT(ether_echo, &typestruct);
77
78static int
79ngee_cons(node_p node)
80{
81	return (0);
82}
83
84/*
85 * Receive control message. We just bounce it back as a reply.
86 */
87static int
88ngee_rcvmsg(node_p node, item_p item, hook_p lasthook)
89{
90	struct ng_mesg *msg;
91	int error = 0;
92
93	NGI_GET_MSG(item, msg);
94	msg->header.flags |= NGF_RESP;
95	NG_RESPOND_MSG(error, node, item, msg);
96	return (error);
97}
98
99/*
100 * Receive data
101 */
102static int
103ngee_rcvdata(hook_p hook, item_p item)
104{
105	int error;
106	struct mbuf *m;
107
108	struct ether_header *eh;
109	struct ether_addr tmpaddr;
110
111	/* Make sure we have an entire header */
112	NGI_GET_M(item, m);
113	if (m->m_len < sizeof(*eh) ) {
114		m = m_pullup(m, sizeof(*eh));
115		if (m == NULL) {
116			NG_FREE_ITEM(item);
117			return(EINVAL);
118		}
119	}
120	eh = mtod(m, struct ether_header *);
121
122	/* swap the source and destination fields */
123	bcopy(eh->ether_dhost, &tmpaddr, ETHER_ADDR_LEN);
124	bcopy(eh->ether_shost, eh->ether_dhost, ETHER_ADDR_LEN);
125	bcopy(&tmpaddr, eh->ether_shost, ETHER_ADDR_LEN);
126
127	NG_FWD_NEW_DATA(error, item, hook, m);
128	return (error);
129}
130
131/*
132 * Removal of the last link destroys the nodeo
133 */
134static int
135ngee_disconnect(hook_p hook)
136{
137	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
138	&& (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) {
139		ng_rmnode_self(NG_HOOK_NODE(hook));
140	}
141	return (0);
142}
143