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