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 */
62 static ng_constructor_t ngee_cons;
63 static ng_rcvmsg_t ngee_rcvmsg;
64 static ng_rcvdata_t ngee_rcvdata;
65 static ng_disconnect_t ngee_disconnect;
66
67 /* Netgraph type */
68 static 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 };
76 NETGRAPH_INIT(ether_echo, &typestruct);
77
78 static int
ngee_cons(node_p node)79 ngee_cons(node_p node)
80 {
81 return (0);
82 }
83
84 /*
85 * Receive control message. We just bounce it back as a reply.
86 */
87 static int
ngee_rcvmsg(node_p node,item_p item,hook_p lasthook)88 ngee_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 */
102 static int
ngee_rcvdata(hook_p hook,item_p item)103 ngee_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 */
134 static int
ngee_disconnect(hook_p hook)135 ngee_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