ng_UI.c revision 53913 
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 53913 1999-11-30 02:45:32Z archie $
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 ng_UI_private {
71	hook_p  downlink;
72	hook_p  uplink;
73};
74typedef struct ng_UI_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	NULL
99};
100NETGRAPH_INIT(UI, &typestruct);
101
102/************************************************************************
103			NETGRAPH NODE STUFF
104 ************************************************************************/
105
106/*
107 * Create a newborn node. We start with an implicit reference.
108 */
109
110static int
111ng_UI_constructor(node_p *nodep)
112{
113	priv_p  priv;
114	int     error;
115
116	/* Allocate private structure */
117	MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_WAITOK);
118	if (priv == NULL)
119		return (ENOMEM);
120	bzero(priv, sizeof(*priv));
121
122	/* Call generic node constructor */
123	if ((error = ng_make_node_common(&typestruct, nodep))) {
124		FREE(priv, M_NETGRAPH);
125		return (error);
126	}
127	(*nodep)->private = priv;
128
129	/* Done */
130	return (0);
131}
132
133/*
134 * Give our ok for a hook to be added
135 */
136static int
137ng_UI_newhook(node_p node, hook_p hook, const char *name)
138{
139	const priv_p priv = node->private;
140
141	if (!strcmp(name, NG_UI_HOOK_DOWNSTREAM)) {
142		if (priv->downlink)
143			return (EISCONN);
144		priv->downlink = hook;
145	} else if (!strcmp(name, NG_UI_HOOK_UPSTREAM)) {
146		if (priv->uplink)
147			return (EISCONN);
148		priv->uplink = hook;
149	} else
150		return (EINVAL);
151	return (0);
152}
153
154/*
155 * Receive a control message
156 */
157static int
158ng_UI_rcvmsg(node_p node, struct ng_mesg *msg,
159	     const char *raddr, struct ng_mesg **rp)
160{
161	FREE(msg, M_NETGRAPH);
162	return (EINVAL);
163}
164
165#define MAX_ENCAPS_HDR	1
166#define ERROUT(x)	do { error = (x); goto done; } while (0)
167
168/*
169 * Receive a data frame
170 */
171static int
172ng_UI_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
173{
174	const node_p node = hook->node;
175	const priv_p priv = node->private;
176	int error = 0;
177
178	if (hook == priv->downlink) {
179		u_char *start, *ptr;
180
181		if (!m || (m->m_len < MAX_ENCAPS_HDR
182		    && !(m = m_pullup(m, MAX_ENCAPS_HDR))))
183			ERROUT(ENOBUFS);
184		ptr = start = mtod(m, u_char *);
185
186		/* Must be UI frame */
187		if (*ptr++ != HDLC_UI)
188			ERROUT(0);
189
190		m_adj(m, ptr - start);
191		NG_SEND_DATA(error, priv->uplink, m, meta);	/* m -> NULL */
192	} else if (hook == priv->uplink) {
193		M_PREPEND(m, 1, M_DONTWAIT);	/* Prepend IP NLPID */
194		if (!m)
195			ERROUT(ENOBUFS);
196		mtod(m, u_char *)[0] = HDLC_UI;
197		NG_SEND_DATA(error, priv->downlink, m, meta);	/* m -> NULL */
198	} else
199		panic(__FUNCTION__);
200
201done:
202	NG_FREE_DATA(m, meta);	/* does nothing if m == NULL */
203	return (error);
204}
205
206/*
207 * Shutdown node
208 */
209static int
210ng_UI_rmnode(node_p node)
211{
212	const priv_p priv = node->private;
213
214	/* Take down netgraph node */
215	node->flags |= NG_INVALID;
216	ng_cutlinks(node);
217	ng_unname(node);
218	bzero(priv, sizeof(*priv));
219	FREE(priv, M_NETGRAPH);
220	node->private = NULL;
221	ng_unref(node);
222	return (0);
223}
224
225/*
226 * Hook disconnection
227 */
228static int
229ng_UI_disconnect(hook_p hook)
230{
231	const priv_p priv = hook->node->private;
232
233	if (hook->node->numhooks == 0)
234		ng_rmnode(hook->node);
235	else if (hook == priv->downlink)
236		priv->downlink = NULL;
237	else if (hook == priv->uplink)
238		priv->uplink = NULL;
239	else
240		panic(__FUNCTION__);
241	return (0);
242}
243
244