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/5.2/sys/netgraph/ng_UI.c 111119 2003-02-19 05:47:46Z imp $
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 NG_ABI_VERSION,
81 NG_UI_NODE_TYPE,
82 NULL,
83 ng_UI_constructor,
84 ng_UI_rcvmsg,
85 ng_UI_shutdown,
86 ng_UI_newhook,
87 NULL,
88 NULL,
89 ng_UI_rcvdata,
90 ng_UI_disconnect,
91 NULL
92 };
93 NETGRAPH_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
103 static int
104 ng_UI_constructor(node_p node)
105 {
106 priv_p priv;
107
108 /* Allocate private structure */
109 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
110 if (priv == NULL) {
111 return (ENOMEM);
112 }
113 NG_NODE_SET_PRIVATE(node, priv);
114 return (0);
115 }
116
117 /*
118 * Give our ok for a hook to be added
119 */
120 static int
121 ng_UI_newhook(node_p node, hook_p hook, const char *name)
122 {
123 const priv_p priv = NG_NODE_PRIVATE(node);
124
125 if (!strcmp(name, NG_UI_HOOK_DOWNSTREAM)) {
126 if (priv->downlink)
127 return (EISCONN);
128 priv->downlink = hook;
129 } else if (!strcmp(name, NG_UI_HOOK_UPSTREAM)) {
130 if (priv->uplink)
131 return (EISCONN);
132 priv->uplink = hook;
133 } else
134 return (EINVAL);
135 return (0);
136 }
137
138 /*
139 * Receive a control message
140 */
141 static int
142 ng_UI_rcvmsg(node_p node, item_p item, hook_p lasthook)
143 {
144 int error;
145 const priv_p priv = NG_NODE_PRIVATE(node);
146 struct ng_mesg *msg;
147
148 msg = NGI_MSG(item); /* only peeking */
149 if ((msg->header.typecookie == NGM_FLOW_COOKIE) && lasthook) {
150 if (lasthook == priv->downlink) {
151 if (priv->uplink) {
152 NG_FWD_ITEM_HOOK(error, item, priv->uplink);
153 return (error);
154 }
155 } else {
156 if (priv->downlink) {
157 NG_FWD_ITEM_HOOK(error, item, priv->downlink);
158 return (error);
159 }
160 }
161 }
162
163 NG_FREE_ITEM(item);
164 return (EINVAL);
165 }
166
167 #define MAX_ENCAPS_HDR 1
168 #define ERROUT(x) do { error = (x); goto done; } while (0)
169
170 /*
171 * Receive a data frame
172 */
173 static int
174 ng_UI_rcvdata(hook_p hook, item_p item)
175 {
176 const node_p node = NG_HOOK_NODE(hook);
177 const priv_p priv = NG_NODE_PRIVATE(node);
178 struct mbuf *m;
179 int error = 0;
180
181 NGI_GET_M(item, m);
182 if (hook == priv->downlink) {
183 u_char *start, *ptr;
184
185 if (!m || (m->m_len < MAX_ENCAPS_HDR
186 && !(m = m_pullup(m, MAX_ENCAPS_HDR))))
187 ERROUT(ENOBUFS);
188 ptr = start = mtod(m, u_char *);
189
190 /* Must be UI frame */
191 if (*ptr++ != HDLC_UI)
192 ERROUT(0);
193
194 m_adj(m, ptr - start);
195 NG_FWD_NEW_DATA(error, item, priv->uplink, m); /* m -> NULL */
196 } else if (hook == priv->uplink) {
197 M_PREPEND(m, 1, M_DONTWAIT); /* Prepend IP NLPID */
198 if (!m)
199 ERROUT(ENOBUFS);
200 mtod(m, u_char *)[0] = HDLC_UI;
201 NG_FWD_NEW_DATA(error, item, priv->downlink, m); /* m -> NULL */
202 } else
203 panic(__func__);
204
205 done:
206 NG_FREE_M(m); /* does nothing if m == NULL */
207 if (item)
208 NG_FREE_ITEM(item);
209 return (error);
210 }
211
212 /*
213 * Shutdown node
214 */
215 static int
216 ng_UI_shutdown(node_p node)
217 {
218 const priv_p priv = NG_NODE_PRIVATE(node);
219
220 /* Take down netgraph node */
221 FREE(priv, M_NETGRAPH);
222 NG_NODE_SET_PRIVATE(node, NULL);
223 NG_NODE_UNREF(node);
224 return (0);
225 }
226
227 /*
228 * Hook disconnection
229 */
230 static int
231 ng_UI_disconnect(hook_p hook)
232 {
233 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
234
235 if (hook == priv->downlink)
236 priv->downlink = NULL;
237 else if (hook == priv->uplink)
238 priv->uplink = NULL;
239 else
240 panic(__func__);
241 /*
242 * If we are not already shutting down,
243 * and we have no more hooks, then DO shut down.
244 */
245 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
246 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) {
247 ng_rmnode_self(NG_HOOK_NODE(hook));
248 }
249 return (0);
250 }
251
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