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@freebsd.org>
38 *
39 * $FreeBSD: head/sys/netgraph/ng_UI.c 69922 2000-12-12 18:52:14Z 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/errno.h>
50
51
52#include <netgraph/ng_message.h>
53#include <netgraph/netgraph.h>
54#include <netgraph/ng_UI.h>
55
56/*
57 * DEFINITIONS
58 */
59
60/* Everything, starting with sdlc on has defined UI as 0x03 */
61#define HDLC_UI 0x03
62
63/* Node private data */
64struct ng_UI_private {
65 hook_p downlink;
66 hook_p uplink;
67};
68typedef struct ng_UI_private *priv_p;
69
70/* Netgraph node methods */
71static ng_constructor_t ng_UI_constructor;
72static ng_rcvmsg_t ng_UI_rcvmsg;
73static ng_shutdown_t ng_UI_rmnode;
74static ng_newhook_t ng_UI_newhook;
75static ng_rcvdata_t ng_UI_rcvdata;
76static ng_disconnect_t ng_UI_disconnect;
77
78/* Node type descriptor */
79static struct ng_type typestruct = {
80 NG_VERSION,
81 NG_UI_NODE_TYPE,
82 NULL,
83 ng_UI_constructor,
84 ng_UI_rcvmsg,
85 ng_UI_rmnode,
86 ng_UI_newhook,
87 NULL,
88 NULL,
89 ng_UI_rcvdata,
90 ng_UI_disconnect,
91 NULL
92};
93NETGRAPH_INIT(UI, &typestruct);
94
95/************************************************************************
96 NETGRAPH NODE STUFF
97 ************************************************************************/
98
99/*
100 * Create a newborn node. We start with an implicit reference.
101 */
102
103static int
104ng_UI_constructor(node_p *nodep)
105{
106 priv_p priv;
107 int error;
108
109 /* Allocate private structure */
110 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
111 if (priv == NULL)
112 return (ENOMEM);
113
114 /* Call generic node constructor */
115 if ((error = ng_make_node_common(&typestruct, nodep))) {
116 FREE(priv, M_NETGRAPH);
117 return (error);
118 }
119 (*nodep)->private = priv;
120
121 /* Done */
122 return (0);
123}
124
125/*
126 * Give our ok for a hook to be added
127 */
128static int
129ng_UI_newhook(node_p node, hook_p hook, const char *name)
130{
131 const priv_p priv = node->private;
132
133 if (!strcmp(name, NG_UI_HOOK_DOWNSTREAM)) {
134 if (priv->downlink)
135 return (EISCONN);
136 priv->downlink = hook;
137 } else if (!strcmp(name, NG_UI_HOOK_UPSTREAM)) {
138 if (priv->uplink)
139 return (EISCONN);
140 priv->uplink = hook;
141 } else
142 return (EINVAL);
143 return (0);
144}
145
146/*
147 * Receive a control message
148 */
149static int
150ng_UI_rcvmsg(node_p node, struct ng_mesg *msg,
151 const char *raddr, struct ng_mesg **rp, hook_p lasthook)
152{
153 const priv_p priv = node->private;
154
155 if ((msg->header.typecookie == NGM_FLOW_COOKIE) && lasthook) {
156 if (lasthook == priv->downlink) {
157 if (priv->uplink) {
158 return (ng_send_msg(node, msg, NULL,
159 priv->uplink, raddr, rp));
160 }
161 } else {
162 if (priv->downlink) {
163 return (ng_send_msg(node, msg, NULL,
164 priv->downlink, raddr, rp));
165 }
166 }
167 }
168
169 FREE(msg, M_NETGRAPH);
170 return (EINVAL);
171}
172
173#define MAX_ENCAPS_HDR 1
174#define ERROUT(x) do { error = (x); goto done; } while (0)
175
176/*
177 * Receive a data frame
178 */
179static int
180ng_UI_rcvdata(hook_p hook, struct mbuf *m, meta_p meta,
181 struct mbuf **ret_m, meta_p *ret_meta, struct ng_mesg **resp)
182{
183 const node_p node = hook->node;
184 const priv_p priv = node->private;
185 int error = 0;
186
187 if (hook == priv->downlink) {
188 u_char *start, *ptr;
189
190 if (!m || (m->m_len < MAX_ENCAPS_HDR
191 && !(m = m_pullup(m, MAX_ENCAPS_HDR))))
192 ERROUT(ENOBUFS);
193 ptr = start = mtod(m, u_char *);
194
195 /* Must be UI frame */
196 if (*ptr++ != HDLC_UI)
197 ERROUT(0);
198
199 m_adj(m, ptr - start);
200 NG_SEND_DATA(error, priv->uplink, m, meta); /* m -> NULL */
201 } else if (hook == priv->uplink) {
202 M_PREPEND(m, 1, M_DONTWAIT); /* Prepend IP NLPID */
203 if (!m)
204 ERROUT(ENOBUFS);
205 mtod(m, u_char *)[0] = HDLC_UI;
206 NG_SEND_DATA(error, priv->downlink, m, meta); /* m -> NULL */
207 } else
208 panic(__FUNCTION__);
209
210done:
211 NG_FREE_DATA(m, meta); /* does nothing if m == NULL */
212 return (error);
213}
214
215/*
216 * Shutdown node
217 */
218static int
219ng_UI_rmnode(node_p node)
220{
221 const priv_p priv = node->private;
222
223 /* Take down netgraph node */
224 node->flags |= NG_INVALID;
225 ng_cutlinks(node);
226 ng_unname(node);
227 bzero(priv, sizeof(*priv));
228 FREE(priv, M_NETGRAPH);
229 node->private = NULL;
230 ng_unref(node);
231 return (0);
232}
233
234/*
235 * Hook disconnection
236 */
237static int
238ng_UI_disconnect(hook_p hook)
239{
240 const priv_p priv = hook->node->private;
241
242 if (hook->node->numhooks == 0)
243 ng_rmnode(hook->node);
244 else if (hook == priv->downlink)
245 priv->downlink = NULL;
246 else if (hook == priv->uplink)
247 priv->uplink = NULL;
248 else
249 panic(__FUNCTION__);
250 return (0);
251}
252