ng_UI.c revision 52752 
1
2/*
3 * ng_UI.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 Elischer <julian@whistle.com>
38 *
39 * $FreeBSD: head/sys/netgraph/ng_UI.c 52752 1999-11-01 10:00:40Z julian $
40 * $Whistle: ng_UI.c,v 1.14 1999/11/01 09:24:51 julian Exp $
41 */
42
43#include <sys/param.h>
44#include <sys/systm.h>
45#include <sys/errno.h>
46#include <sys/kernel.h>
47#include <sys/malloc.h>
48#include <sys/mbuf.h>
49#include <sys/conf.h>
50#include <sys/errno.h>
51#include <sys/socket.h>
52#include <sys/syslog.h>
53
54#include <net/if.h>
55#include <netinet/in.h>
56#include <netinet/if_ether.h>
57
58#include <netgraph/ng_message.h>
59#include <netgraph/netgraph.h>
60#include <netgraph/ng_UI.h>
61
62/*
63 * DEFINITIONS
64 */
65
66/* Everything, starting with sdlc on has defined UI as 0x03 */
67#define HDLC_UI	0x03
68
69/* Node private data */
70struct private {
71	hook_p  downlink;
72	hook_p  uplink;
73};
74typedef struct private *priv_p;
75
76/* Netgraph node methods */
77static ng_constructor_t	ng_UI_constructor;
78static ng_rcvmsg_t	ng_UI_rcvmsg;
79static ng_shutdown_t	ng_UI_rmnode;
80static ng_newhook_t	ng_UI_newhook;
81static ng_rcvdata_t	ng_UI_rcvdata;
82static ng_disconnect_t	ng_UI_disconnect;
83
84/* Node type descriptor */
85static struct ng_type typestruct = {
86	NG_VERSION,
87	NG_UI_NODE_TYPE,
88	NULL,
89	ng_UI_constructor,
90	ng_UI_rcvmsg,
91	ng_UI_rmnode,
92	ng_UI_newhook,
93	NULL,
94	NULL,
95	ng_UI_rcvdata,
96	ng_UI_rcvdata,
97	ng_UI_disconnect
98};
99NETGRAPH_INIT(UI, &typestruct);
100
101/************************************************************************
102			NETGRAPH NODE STUFF
103 ************************************************************************/
104
105/*
106 * Create a newborn node. We start with an implicit reference.
107 */
108
109static int
110ng_UI_constructor(node_p *nodep)
111{
112	priv_p  priv;
113	int     error;
114
115	/* Allocate private structure */
116	MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_WAITOK);
117	if (priv == NULL)
118		return (ENOMEM);
119	bzero(priv, sizeof(*priv));
120
121	/* Call generic node constructor */
122	if ((error = ng_make_node_common(&typestruct, nodep))) {
123		FREE(priv, M_NETGRAPH);
124		return (error);
125	}
126	(*nodep)->private = priv;
127
128	/* Done */
129	return (0);
130}
131
132/*
133 * Give our ok for a hook to be added
134 */
135static int
136ng_UI_newhook(node_p node, hook_p hook, const char *name)
137{
138	const priv_p priv = node->private;
139
140	if (!strcmp(name, NG_UI_HOOK_DOWNSTREAM)) {
141		if (priv->downlink)
142			return (EISCONN);
143		priv->downlink = hook;
144	} else if (!strcmp(name, NG_UI_HOOK_UPSTREAM)) {
145		if (priv->uplink)
146			return (EISCONN);
147		priv->uplink = hook;
148	} else
149		return (EINVAL);
150	return (0);
151}
152
153/*
154 * Receive a control message
155 */
156static int
157ng_UI_rcvmsg(node_p node, struct ng_mesg *msg,
158	     const char *raddr, struct ng_mesg **rp)
159{
160	FREE(msg, M_NETGRAPH);
161	return (EINVAL);
162}
163
164#define MAX_ENCAPS_HDR	1
165#define ERROUT(x)	do { error = (x); goto done; } while (0)
166
167/*
168 * Receive a data frame
169 */
170static int
171ng_UI_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
172{
173	const node_p node = hook->node;
174	const priv_p priv = node->private;
175	int error = 0;
176
177	if (hook == priv->downlink) {
178		u_char *start, *ptr;
179
180		if (!m || (m->m_len < MAX_ENCAPS_HDR
181		    && !(m = m_pullup(m, MAX_ENCAPS_HDR))))
182			ERROUT(ENOBUFS);
183		ptr = start = mtod(m, u_char *);
184
185		/* Must be UI frame */
186		if (*ptr++ != HDLC_UI)
187			ERROUT(0);
188
189		m_adj(m, ptr - start);
190		NG_SEND_DATA(error, priv->uplink, m, meta);	/* m -> NULL */
191	} else if (hook == priv->uplink) {
192		M_PREPEND(m, 1, M_DONTWAIT);	/* Prepend IP NLPID */
193		if (!m)
194			ERROUT(ENOBUFS);
195		mtod(m, u_char *)[0] = HDLC_UI;
196		NG_SEND_DATA(error, priv->downlink, m, meta);	/* m -> NULL */
197	} else
198		panic(__FUNCTION__);
199
200done:
201	NG_FREE_DATA(m, meta);	/* does nothing if m == NULL */
202	return (error);
203}
204
205/*
206 * Shutdown node
207 */
208static int
209ng_UI_rmnode(node_p node)
210{
211	const priv_p priv = node->private;
212
213	/* Take down netgraph node */
214	node->flags |= NG_INVALID;
215	ng_cutlinks(node);
216	ng_unname(node);
217	bzero(priv, sizeof(*priv));
218	FREE(priv, M_NETGRAPH);
219	node->private = NULL;
220	ng_unref(node);
221	return (0);
222}
223
224/*
225 * Hook disconnection
226 */
227static int
228ng_UI_disconnect(hook_p hook)
229{
230	const priv_p priv = hook->node->private;
231
232	if (hook->node->numhooks == 0)
233		ng_rmnode(hook->node);
234	else if (hook == priv->downlink)
235		priv->downlink = NULL;
236	else if (hook == priv->uplink)
237		priv->uplink = NULL;
238	else
239		panic(__FUNCTION__);
240	return (0);
241}
242
243