1 /*
2 * ng_UI.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 Elischer <julian@freebsd.org>
39 *
40 * $FreeBSD: src/sys/netgraph/ng_UI.c,v 1.20 2005/01/07 01:45:39 imp Exp $
41 * $Whistle: ng_UI.c,v 1.14 1999/11/01 09:24:51 julian Exp $
42 */
43
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/errno.h>
47 #include <sys/kernel.h>
48 #include <sys/malloc.h>
49 #include <sys/mbuf.h>
50
51 #include <netgraph7/ng_message.h>
52 #include <netgraph7/netgraph.h>
53 #include "ng_UI.h"
54
55 /*
56 * DEFINITIONS
57 */
58
59 /* Everything, starting with sdlc on has defined UI as 0x03 */
60 #define HDLC_UI 0x03
61
62 /* Node private data */
63 struct ng_UI_private {
64 hook_p downlink;
65 hook_p uplink;
66 };
67 typedef struct ng_UI_private *priv_p;
68
69 /* Netgraph node methods */
70 static ng_constructor_t ng_UI_constructor;
71 static ng_rcvmsg_t ng_UI_rcvmsg;
72 static ng_shutdown_t ng_UI_shutdown;
73 static ng_newhook_t ng_UI_newhook;
74 static ng_rcvdata_t ng_UI_rcvdata;
75 static ng_disconnect_t ng_UI_disconnect;
76
77 /* Node type descriptor */
78 static struct ng_type typestruct = {
79 .version = NG_ABI_VERSION,
80 .name = NG_UI_NODE_TYPE,
81 .constructor = ng_UI_constructor,
82 .rcvmsg = ng_UI_rcvmsg,
83 .shutdown = ng_UI_shutdown,
84 .newhook = ng_UI_newhook,
85 .rcvdata = ng_UI_rcvdata,
86 .disconnect = ng_UI_disconnect,
87 };
88 NETGRAPH_INIT(UI, &typestruct);
89
90 /************************************************************************
91 NETGRAPH NODE STUFF
92 ************************************************************************/
93
94 /*
95 * Create a newborn node. We start with an implicit reference.
96 */
97
98 static int
ng_UI_constructor(node_p node)99 ng_UI_constructor(node_p node)
100 {
101 priv_p priv;
102
103 /* Allocate private structure */
104 priv = kmalloc(sizeof(*priv), M_NETGRAPH,
105 M_WAITOK | M_NULLOK | M_ZERO);
106 if (priv == NULL) {
107 return (ENOMEM);
108 }
109 NG_NODE_SET_PRIVATE(node, priv);
110 return (0);
111 }
112
113 /*
114 * Give our ok for a hook to be added
115 */
116 static int
ng_UI_newhook(node_p node,hook_p hook,const char * name)117 ng_UI_newhook(node_p node, hook_p hook, const char *name)
118 {
119 const priv_p priv = NG_NODE_PRIVATE(node);
120
121 if (!strcmp(name, NG_UI_HOOK_DOWNSTREAM)) {
122 if (priv->downlink)
123 return (EISCONN);
124 priv->downlink = hook;
125 } else if (!strcmp(name, NG_UI_HOOK_UPSTREAM)) {
126 if (priv->uplink)
127 return (EISCONN);
128 priv->uplink = hook;
129 } else
130 return (EINVAL);
131 return (0);
132 }
133
134 /*
135 * Receive a control message
136 */
137 static int
ng_UI_rcvmsg(node_p node,item_p item,hook_p lasthook)138 ng_UI_rcvmsg(node_p node, item_p item, hook_p lasthook)
139 {
140 int error;
141 const priv_p priv = NG_NODE_PRIVATE(node);
142 struct ng_mesg *msg;
143
144 msg = NGI_MSG(item); /* only peeking */
145 if ((msg->header.typecookie == NGM_FLOW_COOKIE) && lasthook) {
146 if (lasthook == priv->downlink) {
147 if (priv->uplink) {
148 NG_FWD_ITEM_HOOK(error, item, priv->uplink);
149 return (error);
150 }
151 } else {
152 if (priv->downlink) {
153 NG_FWD_ITEM_HOOK(error, item, priv->downlink);
154 return (error);
155 }
156 }
157 }
158
159 NG_FREE_ITEM(item);
160 return (EINVAL);
161 }
162
163 #define MAX_ENCAPS_HDR 1
164 #define ERROUT(x) do { error = (x); goto done; } while (0)
165
166 /*
167 * Receive a data frame
168 */
169 static int
ng_UI_rcvdata(hook_p hook,item_p item)170 ng_UI_rcvdata(hook_p hook, item_p item)
171 {
172 const node_p node = NG_HOOK_NODE(hook);
173 const priv_p priv = NG_NODE_PRIVATE(node);
174 struct mbuf *m;
175 int error = 0;
176
177 NGI_GET_M(item, m);
178 if (hook == priv->downlink) {
179 u_char *start, *ptr;
180
181 if (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_FWD_NEW_DATA(error, item, priv->uplink, m); /* m -> NULL */
192 } else if (hook == priv->uplink) {
193 M_PREPEND(m, 1, M_NOWAIT); /* Prepend IP NLPID */
194 if (!m)
195 ERROUT(ENOBUFS);
196 mtod(m, u_char *)[0] = HDLC_UI;
197 NG_FWD_NEW_DATA(error, item, priv->downlink, m); /* m -> NULL */
198 } else
199 panic(__func__);
200
201 done:
202 NG_FREE_M(m); /* does nothing if m == NULL */
203 if (item)
204 NG_FREE_ITEM(item);
205 return (error);
206 }
207
208 /*
209 * Shutdown node
210 */
211 static int
ng_UI_shutdown(node_p node)212 ng_UI_shutdown(node_p node)
213 {
214 const priv_p priv = NG_NODE_PRIVATE(node);
215
216 /* Take down netgraph node */
217 kfree(priv, M_NETGRAPH);
218 NG_NODE_SET_PRIVATE(node, NULL);
219 NG_NODE_UNREF(node);
220 return (0);
221 }
222
223 /*
224 * Hook disconnection
225 */
226 static int
ng_UI_disconnect(hook_p hook)227 ng_UI_disconnect(hook_p hook)
228 {
229 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
230
231 if (hook == priv->downlink)
232 priv->downlink = NULL;
233 else if (hook == priv->uplink)
234 priv->uplink = NULL;
235 else
236 panic(__func__);
237 /*
238 * If we are not already shutting down,
239 * and we have no more hooks, then DO shut down.
240 */
241 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
242 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) {
243 ng_rmnode_self(NG_HOOK_NODE(hook));
244 }
245 return (0);
246 }
247
248