FreeBSD/Linux Kernel Cross Reference
sys/netgraph/ng_UI.c
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: releng/10.2/sys/netgraph/ng_UI.c 243882 2012-12-05 08:04:20Z glebius $
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 #include <sys/errno.h>
51
52
53 #include <netgraph/ng_message.h>
54 #include <netgraph/netgraph.h>
55 #include <netgraph/ng_UI.h>
56
57 /*
58 * DEFINITIONS
59 */
60
61 /* Everything, starting with sdlc on has defined UI as 0x03 */
62 #define HDLC_UI 0x03
63
64 /* Node private data */
65 struct ng_UI_private {
66 hook_p downlink;
67 hook_p uplink;
68 };
69 typedef struct ng_UI_private *priv_p;
70
71 /* Netgraph node methods */
72 static ng_constructor_t ng_UI_constructor;
73 static ng_rcvmsg_t ng_UI_rcvmsg;
74 static ng_shutdown_t ng_UI_shutdown;
75 static ng_newhook_t ng_UI_newhook;
76 static ng_rcvdata_t ng_UI_rcvdata;
77 static ng_disconnect_t ng_UI_disconnect;
78
79 /* Node type descriptor */
80 static struct ng_type typestruct = {
81 .version = NG_ABI_VERSION,
82 .name = NG_UI_NODE_TYPE,
83 .constructor = ng_UI_constructor,
84 .rcvmsg = ng_UI_rcvmsg,
85 .shutdown = ng_UI_shutdown,
86 .newhook = ng_UI_newhook,
87 .rcvdata = ng_UI_rcvdata,
88 .disconnect = ng_UI_disconnect,
89 };
90 NETGRAPH_INIT(UI, &typestruct);
91
92 /************************************************************************
93 NETGRAPH NODE STUFF
94 ************************************************************************/
95
96 /*
97 * Create a newborn node. We start with an implicit reference.
98 */
99
100 static int
101 ng_UI_constructor(node_p node)
102 {
103 priv_p priv;
104
105 /* Allocate private structure */
106 priv = malloc(sizeof(*priv), M_NETGRAPH, M_WAITOK | M_ZERO);
107 NG_NODE_SET_PRIVATE(node, priv);
108 return (0);
109 }
110
111 /*
112 * Give our ok for a hook to be added
113 */
114 static int
115 ng_UI_newhook(node_p node, hook_p hook, const char *name)
116 {
117 const priv_p priv = NG_NODE_PRIVATE(node);
118
119 if (!strcmp(name, NG_UI_HOOK_DOWNSTREAM)) {
120 if (priv->downlink)
121 return (EISCONN);
122 priv->downlink = hook;
123 } else if (!strcmp(name, NG_UI_HOOK_UPSTREAM)) {
124 if (priv->uplink)
125 return (EISCONN);
126 priv->uplink = hook;
127 } else
128 return (EINVAL);
129 return (0);
130 }
131
132 /*
133 * Receive a control message
134 */
135 static int
136 ng_UI_rcvmsg(node_p node, item_p item, hook_p lasthook)
137 {
138 int error;
139 const priv_p priv = NG_NODE_PRIVATE(node);
140 struct ng_mesg *msg;
141
142 msg = NGI_MSG(item); /* only peeking */
143 if ((msg->header.typecookie == NGM_FLOW_COOKIE) && lasthook) {
144 if (lasthook == priv->downlink) {
145 if (priv->uplink) {
146 NG_FWD_ITEM_HOOK(error, item, priv->uplink);
147 return (error);
148 }
149 } else {
150 if (priv->downlink) {
151 NG_FWD_ITEM_HOOK(error, item, priv->downlink);
152 return (error);
153 }
154 }
155 }
156
157 NG_FREE_ITEM(item);
158 return (EINVAL);
159 }
160
161 #define MAX_ENCAPS_HDR 1
162 #define ERROUT(x) do { error = (x); goto done; } while (0)
163
164 /*
165 * Receive a data frame
166 */
167 static int
168 ng_UI_rcvdata(hook_p hook, item_p item)
169 {
170 const node_p node = NG_HOOK_NODE(hook);
171 const priv_p priv = NG_NODE_PRIVATE(node);
172 struct mbuf *m;
173 int error = 0;
174
175 NGI_GET_M(item, m);
176 if (hook == priv->downlink) {
177 u_char *start, *ptr;
178
179 if (m->m_len < MAX_ENCAPS_HDR
180 && !(m = m_pullup(m, MAX_ENCAPS_HDR)))
181 ERROUT(ENOBUFS);
182 ptr = start = mtod(m, u_char *);
183
184 /* Must be UI frame */
185 if (*ptr++ != HDLC_UI)
186 ERROUT(0);
187
188 m_adj(m, ptr - start);
189 NG_FWD_NEW_DATA(error, item, priv->uplink, m); /* m -> NULL */
190 } else if (hook == priv->uplink) {
191 M_PREPEND(m, 1, M_NOWAIT); /* Prepend IP NLPID */
192 if (!m)
193 ERROUT(ENOBUFS);
194 mtod(m, u_char *)[0] = HDLC_UI;
195 NG_FWD_NEW_DATA(error, item, priv->downlink, m); /* m -> NULL */
196 } else
197 panic("%s", __func__);
198
199 done:
200 NG_FREE_M(m); /* does nothing if m == NULL */
201 if (item)
202 NG_FREE_ITEM(item);
203 return (error);
204 }
205
206 /*
207 * Shutdown node
208 */
209 static int
210 ng_UI_shutdown(node_p node)
211 {
212 const priv_p priv = NG_NODE_PRIVATE(node);
213
214 /* Take down netgraph node */
215 free(priv, M_NETGRAPH);
216 NG_NODE_SET_PRIVATE(node, NULL);
217 NG_NODE_UNREF(node);
218 return (0);
219 }
220
221 /*
222 * Hook disconnection
223 */
224 static int
225 ng_UI_disconnect(hook_p hook)
226 {
227 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
228
229 if (hook == priv->downlink)
230 priv->downlink = NULL;
231 else if (hook == priv->uplink)
232 priv->uplink = NULL;
233 else
234 panic("%s", __func__);
235 /*
236 * If we are not already shutting down,
237 * and we have no more hooks, then DO shut down.
238 */
239 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
240 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) {
241 ng_rmnode_self(NG_HOOK_NODE(hook));
242 }
243 return (0);
244 }
245
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