FreeBSD/Linux Kernel Cross Reference
sys/netgraph/ng_UI.c
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: releng/5.3/sys/netgraph/ng_UI.c 136588 2004-10-16 08:43:07Z cvs2svn $
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 */
64 struct ng_UI_private {
65 hook_p downlink;
66 hook_p uplink;
67 };
68 typedef struct ng_UI_private *priv_p;
69
70 /* Netgraph node methods */
71 static ng_constructor_t ng_UI_constructor;
72 static ng_rcvmsg_t ng_UI_rcvmsg;
73 static ng_shutdown_t ng_UI_shutdown;
74 static ng_newhook_t ng_UI_newhook;
75 static ng_rcvdata_t ng_UI_rcvdata;
76 static ng_disconnect_t ng_UI_disconnect;
77
78 /* Node type descriptor */
79 static struct ng_type typestruct = {
80 .version = NG_ABI_VERSION,
81 .name = NG_UI_NODE_TYPE,
82 .constructor = ng_UI_constructor,
83 .rcvmsg = ng_UI_rcvmsg,
84 .shutdown = ng_UI_shutdown,
85 .newhook = ng_UI_newhook,
86 .rcvdata = ng_UI_rcvdata,
87 .disconnect = ng_UI_disconnect,
88 };
89 NETGRAPH_INIT(UI, &typestruct);
90
91 /************************************************************************
92 NETGRAPH NODE STUFF
93 ************************************************************************/
94
95 /*
96 * Create a newborn node. We start with an implicit reference.
97 */
98
99 static int
100 ng_UI_constructor(node_p node)
101 {
102 priv_p priv;
103
104 /* Allocate private structure */
105 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT | 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
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
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
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_DONTWAIT); /* 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
212 ng_UI_shutdown(node_p node)
213 {
214 const priv_p priv = NG_NODE_PRIVATE(node);
215
216 /* Take down netgraph node */
217 FREE(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
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
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