ng_hole.c revision 129823 
1
2/*
3 * ng_hole.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@freebsd.org>
38 *
39 * $FreeBSD: head/sys/netgraph/ng_hole.c 129823 2004-05-29 00:51:19Z julian $
40 * $Whistle: ng_hole.c,v 1.10 1999/11/01 09:24:51 julian Exp $
41 */
42
43/*
44 * This node is a 'black hole' that simply discards everything it receives
45 */
46
47#include <sys/param.h>
48#include <sys/systm.h>
49#include <sys/kernel.h>
50#include <sys/malloc.h>
51#include <sys/mbuf.h>
52#include <netgraph/ng_message.h>
53#include <netgraph/netgraph.h>
54#include <netgraph/ng_parse.h>
55#include <netgraph/ng_hole.h>
56
57/* Per hook private info. */
58struct ng_hole_hookinfo {
59	struct ng_hole_hookstat	stats;
60};
61typedef struct ng_hole_hookinfo *hinfo_p;
62
63/* Parse type for struct ng_hole_hookstat. */
64static const struct ng_parse_struct_field ng_hole_hookstat_type_fields[] =
65	NG_HOLE_HOOKSTAT_TYPE_INFO;
66static const struct ng_parse_type ng_hole_hookstat_type = {
67	&ng_parse_struct_type,
68	&ng_hole_hookstat_type_fields
69};
70
71/* List of commands and how to convert arguments to/from ASCII. */
72static const struct ng_cmdlist ng_hole_cmdlist[] = {
73	{
74	  NGM_HOLE_COOKIE,
75	  NGM_HOLE_GET_STATS,
76	  "getstats",
77	  &ng_parse_hookbuf_type,
78	  &ng_hole_hookstat_type
79	},
80	{
81	  NGM_HOLE_COOKIE,
82	  NGM_HOLE_CLR_STATS,
83	  "clrstats",
84	  &ng_parse_hookbuf_type,
85	  NULL
86	},
87	{
88	  NGM_HOLE_COOKIE,
89	  NGM_HOLE_GETCLR_STATS,
90	  "getclrstats",
91	  &ng_parse_hookbuf_type,
92	  &ng_hole_hookstat_type
93	},
94	{ 0 }
95};
96
97/* Netgraph methods */
98static ng_constructor_t	ngh_cons;
99static ng_rcvmsg_t	ngh_rcvmsg;
100static ng_newhook_t	ngh_newhook;
101static ng_rcvdata_t	ngh_rcvdata;
102static ng_disconnect_t	ngh_disconnect;
103
104static struct ng_type typestruct = {
105	.version =	NG_ABI_VERSION,
106	.name =		NG_HOLE_NODE_TYPE,
107	.constructor =	ngh_cons,
108	.rcvmsg =	ngh_rcvmsg,
109	.newhook = 	ngh_newhook,
110	.rcvdata =	ngh_rcvdata,
111	.disconnect =	ngh_disconnect,
112	.cmdlist =	ng_hole_cmdlist,
113};
114NETGRAPH_INIT(hole, &typestruct);
115
116/*
117 * Be obliging. but no work to do.
118 */
119static int
120ngh_cons(node_p node)
121{
122	return(0);
123}
124
125/*
126 * Add a hook.
127 */
128static int
129ngh_newhook(node_p node, hook_p hook, const char *name)
130{
131	hinfo_p hip;
132
133	/* Create hook private structure. */
134	MALLOC(hip, hinfo_p, sizeof(*hip), M_NETGRAPH, M_NOWAIT | M_ZERO);
135	if (hip == NULL)
136		return (ENOMEM);
137	NG_HOOK_SET_PRIVATE(hook, hip);
138	return (0);
139}
140
141/*
142 * Receive a control message.
143 */
144static int
145ngh_rcvmsg(node_p node, item_p item, hook_p lasthook)
146{
147	struct ng_mesg *msg;
148	struct ng_mesg *resp = NULL;
149	int error = 0;
150	struct ng_hole_hookstat *stats;
151	hook_p hook;
152
153	NGI_GET_MSG(item, msg);
154	switch (msg->header.typecookie) {
155	case NGM_HOLE_COOKIE:
156		switch (msg->header.cmd) {
157		case NGM_HOLE_GET_STATS:
158		case NGM_HOLE_CLR_STATS:
159		case NGM_HOLE_GETCLR_STATS:
160			/* Sanity check. */
161			if (msg->header.arglen != NG_HOOKSIZ) {
162				error = EINVAL;
163				break;
164			}
165			/* Find hook. */
166			hook = ng_findhook(node, (char *)msg->data);
167			if (hook == NULL) {
168				error = ENOENT;
169				break;
170			}
171			stats = &((hinfo_p)NG_HOOK_PRIVATE(hook))->stats;
172			/* Build response (if desired). */
173			if (msg->header.cmd != NGM_HOLE_CLR_STATS) {
174				NG_MKRESPONSE(resp, msg, sizeof(*stats),
175				    M_NOWAIT);
176				if (resp == NULL) {
177					error = ENOMEM;
178					break;
179				}
180				bcopy(stats, resp->data, sizeof(*stats));
181			}
182			/* Clear stats (if desired). */
183			if (msg->header.cmd != NGM_HOLE_GET_STATS)
184				bzero(stats, sizeof(*stats));
185			break;
186		default:		/* Unknown command. */
187			error = EINVAL;
188			break;
189		}
190		break;
191	default:			/* Unknown type cookie. */
192		error = EINVAL;
193		break;
194	}
195	NG_RESPOND_MSG(error, node, item, resp);
196	NG_FREE_MSG(msg);
197	return (error);
198}
199
200/*
201 * Receive data
202 */
203static int
204ngh_rcvdata(hook_p hook, item_p item)
205{
206	const hinfo_p hip = NG_HOOK_PRIVATE(hook);
207
208	hip->stats.frames++;
209	hip->stats.octets += NGI_M(item)->m_pkthdr.len;
210	NG_FREE_ITEM(item);
211	return 0;
212}
213
214/*
215 * Hook disconnection
216 */
217static int
218ngh_disconnect(hook_p hook)
219{
220
221	NG_HOOK_SET_PRIVATE(hook, NULL);
222	if (NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
223		ng_rmnode_self(NG_HOOK_NODE(hook));
224	return (0);
225}
226