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: src/sys/netgraph/ng_UI.c,v 1.6.2.2 2000/10/24 18:36:44 julian Exp $
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
50 #include <netgraph/ng_message.h>
51 #include <netgraph/netgraph.h>
52 #include "ng_UI.h"
53
54 /*
55 * DEFINITIONS
56 */
57
58 /* Everything, starting with sdlc on has defined UI as 0x03 */
59 #define HDLC_UI 0x03
60
61 /* Node private data */
62 struct ng_UI_private {
63 hook_p downlink;
64 hook_p uplink;
65 };
66 typedef struct ng_UI_private *priv_p;
67
68 /* Netgraph node methods */
69 static ng_constructor_t ng_UI_constructor;
70 static ng_rcvmsg_t ng_UI_rcvmsg;
71 static ng_shutdown_t ng_UI_rmnode;
72 static ng_newhook_t ng_UI_newhook;
73 static ng_rcvdata_t ng_UI_rcvdata;
74 static ng_disconnect_t ng_UI_disconnect;
75
76 /* Node type descriptor */
77 static struct ng_type typestruct = {
78 NG_VERSION,
79 NG_UI_NODE_TYPE,
80 NULL,
81 ng_UI_constructor,
82 ng_UI_rcvmsg,
83 ng_UI_rmnode,
84 ng_UI_newhook,
85 NULL,
86 NULL,
87 ng_UI_rcvdata,
88 ng_UI_rcvdata,
89 ng_UI_disconnect,
90 NULL
91 };
92 NETGRAPH_INIT(UI, &typestruct);
93
94 /************************************************************************
95 NETGRAPH NODE STUFF
96 ************************************************************************/
97
98 /*
99 * Create a newborn node. We start with an implicit reference.
100 */
101
102 static int
ng_UI_constructor(node_p * nodep)103 ng_UI_constructor(node_p *nodep)
104 {
105 priv_p priv;
106 int error;
107
108 /* Allocate private structure */
109 priv = kmalloc(sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
110 if (priv == NULL)
111 return (ENOMEM);
112
113 /* Call generic node constructor */
114 if ((error = ng_make_node_common(&typestruct, nodep))) {
115 kfree(priv, M_NETGRAPH);
116 return (error);
117 }
118 (*nodep)->private = priv;
119
120 /* Done */
121 return (0);
122 }
123
124 /*
125 * Give our ok for a hook to be added
126 */
127 static int
ng_UI_newhook(node_p node,hook_p hook,const char * name)128 ng_UI_newhook(node_p node, hook_p hook, const char *name)
129 {
130 const priv_p priv = node->private;
131
132 if (!strcmp(name, NG_UI_HOOK_DOWNSTREAM)) {
133 if (priv->downlink)
134 return (EISCONN);
135 priv->downlink = hook;
136 } else if (!strcmp(name, NG_UI_HOOK_UPSTREAM)) {
137 if (priv->uplink)
138 return (EISCONN);
139 priv->uplink = hook;
140 } else
141 return (EINVAL);
142 return (0);
143 }
144
145 /*
146 * Receive a control message
147 */
148 static int
ng_UI_rcvmsg(node_p node,struct ng_mesg * msg,const char * raddr,struct ng_mesg ** rp)149 ng_UI_rcvmsg(node_p node, struct ng_mesg *msg,
150 const char *raddr, struct ng_mesg **rp)
151 {
152 kfree(msg, M_NETGRAPH);
153 return (EINVAL);
154 }
155
156 #define MAX_ENCAPS_HDR 1
157 #define ERROUT(x) do { error = (x); goto done; } while (0)
158
159 /*
160 * Receive a data frame
161 */
162 static int
ng_UI_rcvdata(hook_p hook,struct mbuf * m,meta_p meta)163 ng_UI_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
164 {
165 const node_p node = hook->node;
166 const priv_p priv = node->private;
167 int error = 0;
168
169 if (hook == priv->downlink) {
170 u_char *start, *ptr;
171
172 if (!m || (m->m_len < MAX_ENCAPS_HDR
173 && !(m = m_pullup(m, MAX_ENCAPS_HDR))))
174 ERROUT(ENOBUFS);
175 ptr = start = mtod(m, u_char *);
176
177 /* Must be UI frame */
178 if (*ptr++ != HDLC_UI)
179 ERROUT(0);
180
181 m_adj(m, ptr - start);
182 NG_SEND_DATA(error, priv->uplink, m, meta); /* m -> NULL */
183 } else if (hook == priv->uplink) {
184 M_PREPEND(m, 1, M_NOWAIT); /* Prepend IP NLPID */
185 if (!m)
186 ERROUT(ENOBUFS);
187 mtod(m, u_char *)[0] = HDLC_UI;
188 NG_SEND_DATA(error, priv->downlink, m, meta); /* m -> NULL */
189 } else
190 panic(__func__);
191
192 done:
193 NG_FREE_DATA(m, meta); /* does nothing if m == NULL */
194 return (error);
195 }
196
197 /*
198 * Shutdown node
199 */
200 static int
ng_UI_rmnode(node_p node)201 ng_UI_rmnode(node_p node)
202 {
203 const priv_p priv = node->private;
204
205 /* Take down netgraph node */
206 node->flags |= NG_INVALID;
207 ng_cutlinks(node);
208 ng_unname(node);
209 bzero(priv, sizeof(*priv));
210 kfree(priv, M_NETGRAPH);
211 node->private = NULL;
212 ng_unref(node);
213 return (0);
214 }
215
216 /*
217 * Hook disconnection
218 */
219 static int
ng_UI_disconnect(hook_p hook)220 ng_UI_disconnect(hook_p hook)
221 {
222 const priv_p priv = hook->node->private;
223
224 if (hook->node->numhooks == 0)
225 ng_rmnode(hook->node);
226 else if (hook == priv->downlink)
227 priv->downlink = NULL;
228 else if (hook == priv->uplink)
229 priv->uplink = NULL;
230 else
231 panic(__func__);
232 return (0);
233 }
234
235