1/*
2 * ng_hole.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 * $FreeBSD$
41 * $Whistle: ng_hole.c,v 1.10 1999/11/01 09:24:51 julian Exp $
42 */
43
44/*
45 * This node is a 'black hole' that simply discards everything it receives
46 */
47
48#include <sys/param.h>
49#include <sys/systm.h>
50#include <sys/kernel.h>
51#include <sys/malloc.h>
52#include <sys/mbuf.h>
53#include <netgraph/ng_message.h>
54#include <netgraph/netgraph.h>
55#include <netgraph/ng_parse.h>
56#include <netgraph/ng_hole.h>
57
58/* Per hook private info. */
59struct ng_hole_hookinfo {
60	struct ng_hole_hookstat	stats;
61};
62typedef struct ng_hole_hookinfo *hinfo_p;
63
64/* Parse type for struct ng_hole_hookstat. */
65static const struct ng_parse_struct_field ng_hole_hookstat_type_fields[] =
66	NG_HOLE_HOOKSTAT_TYPE_INFO;
67static const struct ng_parse_type ng_hole_hookstat_type = {
68	&ng_parse_struct_type,
69	&ng_hole_hookstat_type_fields
70};
71
72/* List of commands and how to convert arguments to/from ASCII. */
73static const struct ng_cmdlist ng_hole_cmdlist[] = {
74	{
75	  NGM_HOLE_COOKIE,
76	  NGM_HOLE_GET_STATS,
77	  "getstats",
78	  &ng_parse_hookbuf_type,
79	  &ng_hole_hookstat_type
80	},
81	{
82	  NGM_HOLE_COOKIE,
83	  NGM_HOLE_CLR_STATS,
84	  "clrstats",
85	  &ng_parse_hookbuf_type,
86	  NULL
87	},
88	{
89	  NGM_HOLE_COOKIE,
90	  NGM_HOLE_GETCLR_STATS,
91	  "getclrstats",
92	  &ng_parse_hookbuf_type,
93	  &ng_hole_hookstat_type
94	},
95	{ 0 }
96};
97
98/* Netgraph methods */
99static ng_constructor_t	ngh_cons;
100static ng_rcvmsg_t	ngh_rcvmsg;
101static ng_newhook_t	ngh_newhook;
102static ng_rcvdata_t	ngh_rcvdata;
103static ng_disconnect_t	ngh_disconnect;
104
105static struct ng_type typestruct = {
106	.version =	NG_ABI_VERSION,
107	.name =		NG_HOLE_NODE_TYPE,
108	.constructor =	ngh_cons,
109	.rcvmsg =	ngh_rcvmsg,
110	.newhook = 	ngh_newhook,
111	.rcvdata =	ngh_rcvdata,
112	.disconnect =	ngh_disconnect,
113	.cmdlist =	ng_hole_cmdlist,
114};
115NETGRAPH_INIT(hole, &typestruct);
116
117/*
118 * Be obliging. but no work to do.
119 */
120static int
121ngh_cons(node_p node)
122{
123	return(0);
124}
125
126/*
127 * Add a hook.
128 */
129static int
130ngh_newhook(node_p node, hook_p hook, const char *name)
131{
132	hinfo_p hip;
133
134	/* Create hook private structure. */
135	hip = malloc(sizeof(*hip), M_NETGRAPH, M_NOWAIT | M_ZERO);
136	if (hip == NULL)
137		return (ENOMEM);
138	NG_HOOK_SET_PRIVATE(hook, hip);
139	return (0);
140}
141
142/*
143 * Receive a control message.
144 */
145static int
146ngh_rcvmsg(node_p node, item_p item, hook_p lasthook)
147{
148	struct ng_mesg *msg;
149	struct ng_mesg *resp = NULL;
150	int error = 0;
151	struct ng_hole_hookstat *stats;
152	hook_p hook;
153
154	NGI_GET_MSG(item, msg);
155	switch (msg->header.typecookie) {
156	case NGM_HOLE_COOKIE:
157		switch (msg->header.cmd) {
158		case NGM_HOLE_GET_STATS:
159		case NGM_HOLE_CLR_STATS:
160		case NGM_HOLE_GETCLR_STATS:
161			/* Sanity check. */
162			if (msg->header.arglen != NG_HOOKSIZ) {
163				error = EINVAL;
164				break;
165			}
166			/* Find hook. */
167			hook = ng_findhook(node, (char *)msg->data);
168			if (hook == NULL) {
169				error = ENOENT;
170				break;
171			}
172			stats = &((hinfo_p)NG_HOOK_PRIVATE(hook))->stats;
173			/* Build response (if desired). */
174			if (msg->header.cmd != NGM_HOLE_CLR_STATS) {
175				NG_MKRESPONSE(resp, msg, sizeof(*stats),
176				    M_NOWAIT);
177				if (resp == NULL) {
178					error = ENOMEM;
179					break;
180				}
181				bcopy(stats, resp->data, sizeof(*stats));
182			}
183			/* Clear stats (if desired). */
184			if (msg->header.cmd != NGM_HOLE_GET_STATS)
185				bzero(stats, sizeof(*stats));
186			break;
187		default:		/* Unknown command. */
188			error = EINVAL;
189			break;
190		}
191		break;
192	default:			/* Unknown type cookie. */
193		error = EINVAL;
194		break;
195	}
196	NG_RESPOND_MSG(error, node, item, resp);
197	NG_FREE_MSG(msg);
198	return (error);
199}
200
201/*
202 * Receive data
203 */
204static int
205ngh_rcvdata(hook_p hook, item_p item)
206{
207	const hinfo_p hip = NG_HOOK_PRIVATE(hook);
208
209	hip->stats.frames++;
210	hip->stats.octets += NGI_M(item)->m_pkthdr.len;
211	NG_FREE_ITEM(item);
212	return 0;
213}
214
215/*
216 * Hook disconnection
217 */
218static int
219ngh_disconnect(hook_p hook)
220{
221
222	free(NG_HOOK_PRIVATE(hook), M_NETGRAPH);
223	NG_HOOK_SET_PRIVATE(hook, NULL);
224	if (NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
225		ng_rmnode_self(NG_HOOK_NODE(hook));
226	return (0);
227}
228