Vendor import of netgraph from FreeBSD-current 20080626
[dragonfly.git] / sys / netgraph7 / ng_frame_relay.c
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b06ebda0
MD
1/*
2 * ng_frame_relay.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_frame_relay.c,v 1.25 2006/01/14 21:49:31 glebius Exp $
41 * $Whistle: ng_frame_relay.c,v 1.20 1999/11/01 09:24:51 julian Exp $
42 */
43
44/*
45 * This node implements the frame relay protocol, not including
46 * the LMI line management. This means basically keeping track
47 * of which DLCI's are active, doing frame (de)multiplexing, etc.
48 *
49 * It has a 'downstream' hook that goes to the line, and a
50 * hook for each DLCI (eg, 'dlci16').
51 */
52
53#include <sys/param.h>
54#include <sys/systm.h>
55#include <sys/kernel.h>
56#include <sys/errno.h>
57#include <sys/malloc.h>
58#include <sys/mbuf.h>
59#include <sys/syslog.h>
60#include <sys/ctype.h>
61
62#include <netgraph/ng_message.h>
63#include <netgraph/netgraph.h>
64#include <netgraph/ng_frame_relay.h>
65
66/*
67 * Line info, and status per channel.
68 */
69struct ctxinfo { /* one per active hook */
70 u_int flags;
71#define CHAN_VALID 0x01 /* assigned to a channel */
72#define CHAN_ACTIVE 0x02 /* bottom level active */
73 int dlci; /* the dlci assigned to this context */
74 hook_p hook; /* if there's a hook assigned.. */
75};
76
77#define MAX_CT 16 /* # of dlci's active at a time (POWER OF 2!) */
78struct frmrel_softc {
79 int unit; /* which card are we? */
80 int datahooks; /* number of data hooks attached */
81 node_p node; /* netgraph node */
82 int addrlen; /* address header length */
83 int flags; /* state */
84 int mtu; /* guess */
85 u_char remote_seq; /* sequence number the remote sent */
86 u_char local_seq; /* sequence number the remote rcvd */
87 u_short ALT[1024]; /* map DLCIs to CTX */
88#define CTX_VALID 0x8000 /* this bit means it's a valid CTX */
89#define CTX_VALUE (MAX_CT - 1) /* mask for context part */
90 struct ctxinfo channel[MAX_CT];
91 struct ctxinfo downstream;
92};
93typedef struct frmrel_softc *sc_p;
94
95#define BYTEX_EA 0x01 /* End Address. Always 0 on byte1 */
96#define BYTE1_C_R 0x02
97#define BYTE2_FECN 0x08 /* forwards congestion notification */
98#define BYTE2_BECN 0x04 /* Backward congestion notification */
99#define BYTE2_DE 0x02 /* Discard elligability */
100#define LASTBYTE_D_C 0x02 /* last byte is dl_core or dlci info */
101
102/* Used to do headers */
103const static struct segment {
104 u_char mask;
105 u_char shift;
106 u_char width;
107} makeup[] = {
108 { 0xfc, 2, 6 },
109 { 0xf0, 4, 4 },
110 { 0xfe, 1, 7 },
111 { 0xfc, 2, 6 }
112};
113
114#define SHIFTIN(segment, byte, dlci) \
115 { \
116 (dlci) <<= (segment)->width; \
117 (dlci) |= \
118 (((byte) & (segment)->mask) >> (segment)->shift); \
119 }
120
121#define SHIFTOUT(segment, byte, dlci) \
122 { \
123 (byte) |= (((dlci) << (segment)->shift) & (segment)->mask); \
124 (dlci) >>= (segment)->width; \
125 }
126
127/* Netgraph methods */
128static ng_constructor_t ngfrm_constructor;
129static ng_shutdown_t ngfrm_shutdown;
130static ng_newhook_t ngfrm_newhook;
131static ng_rcvdata_t ngfrm_rcvdata;
132static ng_disconnect_t ngfrm_disconnect;
133
134/* Other internal functions */
135static int ngfrm_decode(node_p node, item_p item);
136static int ngfrm_addrlen(char *hdr);
137static int ngfrm_allocate_CTX(sc_p sc, int dlci);
138
139/* Netgraph type */
140static struct ng_type typestruct = {
141 .version = NG_ABI_VERSION,
142 .name = NG_FRAMERELAY_NODE_TYPE,
143 .constructor = ngfrm_constructor,
144 .shutdown = ngfrm_shutdown,
145 .newhook = ngfrm_newhook,
146 .rcvdata = ngfrm_rcvdata,
147 .disconnect = ngfrm_disconnect,
148};
149NETGRAPH_INIT(framerelay, &typestruct);
150
151/*
152 * Given a DLCI, return the index of the context table entry for it,
153 * Allocating a new one if needs be, or -1 if none available.
154 */
155static int
156ngfrm_allocate_CTX(sc_p sc, int dlci)
157{
158 u_int ctxnum = -1; /* what ctx number we are using */
159 volatile struct ctxinfo *CTXp = NULL;
160
161 /* Sanity check the dlci value */
162 if (dlci > 1023)
163 return (-1);
164
165 /* Check to see if we already have an entry for this DLCI */
166 if (sc->ALT[dlci]) {
167 if ((ctxnum = sc->ALT[dlci] & CTX_VALUE) < MAX_CT) {
168 CTXp = sc->channel + ctxnum;
169 } else {
170 ctxnum = -1;
171 sc->ALT[dlci] = 0; /* paranoid but... */
172 }
173 }
174
175 /*
176 * If the index has no valid entry yet, then we need to allocate a
177 * CTX number to it
178 */
179 if (CTXp == NULL) {
180 for (ctxnum = 0; ctxnum < MAX_CT; ctxnum++) {
181 /*
182 * If the VALID flag is empty it is unused
183 */
184 if ((sc->channel[ctxnum].flags & CHAN_VALID) == 0) {
185 bzero(sc->channel + ctxnum,
186 sizeof(struct ctxinfo));
187 CTXp = sc->channel + ctxnum;
188 sc->ALT[dlci] = ctxnum | CTX_VALID;
189 sc->channel[ctxnum].dlci = dlci;
190 sc->channel[ctxnum].flags = CHAN_VALID;
191 break;
192 }
193 }
194 }
195
196 /*
197 * If we still don't have a CTX pointer, then we never found a free
198 * spot so give up now..
199 */
200 if (!CTXp) {
201 log(LOG_ERR, "No CTX available for dlci %d\n", dlci);
202 return (-1);
203 }
204 return (ctxnum);
205}
206
207/*
208 * Node constructor
209 */
210static int
211ngfrm_constructor(node_p node)
212{
213 sc_p sc;
214
215 MALLOC(sc, sc_p, sizeof(*sc), M_NETGRAPH, M_NOWAIT | M_ZERO);
216 if (!sc)
217 return (ENOMEM);
218 sc->addrlen = 2; /* default */
219
220 /* Link the node and our private info */
221 NG_NODE_SET_PRIVATE(node, sc);
222 sc->node = node;
223 return (0);
224}
225
226/*
227 * Add a new hook
228 *
229 * We allow hooks called "debug", "downstream" and dlci[0-1023]
230 * The hook's private info points to our stash of info about that
231 * channel. A NULL pointer is debug and a DLCI of -1 means downstream.
232 */
233static int
234ngfrm_newhook(node_p node, hook_p hook, const char *name)
235{
236 const sc_p sc = NG_NODE_PRIVATE(node);
237 const char *cp;
238 char *eptr;
239 int dlci = 0;
240 int ctxnum;
241
242 /* Check if it's our friend the control hook */
243 if (strcmp(name, NG_FRAMERELAY_HOOK_DEBUG) == 0) {
244 NG_HOOK_SET_PRIVATE(hook, NULL); /* paranoid */
245 return (0);
246 }
247
248 /*
249 * All other hooks either start with 'dlci' and have a decimal
250 * trailing channel number up to 4 digits, or are the downstream
251 * hook.
252 */
253 if (strncmp(name, NG_FRAMERELAY_HOOK_DLCI,
254 strlen(NG_FRAMERELAY_HOOK_DLCI)) != 0) {
255
256 /* It must be the downstream connection */
257 if (strcmp(name, NG_FRAMERELAY_HOOK_DOWNSTREAM) != 0)
258 return EINVAL;
259
260 /* Make sure we haven't already got one (paranoid) */
261 if (sc->downstream.hook)
262 return (EADDRINUSE);
263
264 /* OK add it */
265 NG_HOOK_SET_PRIVATE(hook, &sc->downstream);
266 sc->downstream.hook = hook;
267 sc->downstream.dlci = -1;
268 sc->downstream.flags |= CHAN_ACTIVE;
269 sc->datahooks++;
270 return (0);
271 }
272
273 /* Must be a dlci hook at this point */
274 cp = name + strlen(NG_FRAMERELAY_HOOK_DLCI);
275 if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0'))
276 return (EINVAL);
277 dlci = (int)strtoul(cp, &eptr, 10);
278 if (*eptr != '\0' || dlci < 0 || dlci > 1023)
279 return (EINVAL);
280
281 /*
282 * We have a dlci, now either find it, or allocate it. It's possible
283 * that we might have seen packets for it already and made an entry
284 * for it.
285 */
286 ctxnum = ngfrm_allocate_CTX(sc, dlci);
287 if (ctxnum == -1)
288 return (ENOBUFS);
289
290 /*
291 * Be paranoid: if it's got a hook already, that dlci is in use .
292 * Generic code can not catch all the synonyms (e.g. dlci016 vs
293 * dlci16)
294 */
295 if (sc->channel[ctxnum].hook != NULL)
296 return (EADDRINUSE);
297
298 /*
299 * Put our hooks into it (pun not intended)
300 */
301 sc->channel[ctxnum].flags |= CHAN_ACTIVE;
302 NG_HOOK_SET_PRIVATE(hook, sc->channel + ctxnum);
303 sc->channel[ctxnum].hook = hook;
304 sc->datahooks++;
305 return (0);
306}
307
308/*
309 * Count up the size of the address header if we don't already know
310 */
311int
312ngfrm_addrlen(char *hdr)
313{
314 if (hdr[0] & BYTEX_EA)
315 return 0;
316 if (hdr[1] & BYTEX_EA)
317 return 2;
318 if (hdr[2] & BYTEX_EA)
319 return 3;
320 if (hdr[3] & BYTEX_EA)
321 return 4;
322 return 0;
323}
324
325/*
326 * Receive data packet
327 */
328static int
329ngfrm_rcvdata(hook_p hook, item_p item)
330{
331 struct ctxinfo *const ctxp = NG_HOOK_PRIVATE(hook);
332 struct mbuf *m = NULL;
333 int error = 0;
334 int dlci;
335 sc_p sc;
336 int alen;
337 char *data;
338
339 /* Data doesn't come in from just anywhere (e.g debug hook) */
340 if (ctxp == NULL) {
341 error = ENETDOWN;
342 goto bad;
343 }
344
345 /* If coming from downstream, decode it to a channel */
346 dlci = ctxp->dlci;
347 if (dlci == -1)
348 return (ngfrm_decode(NG_HOOK_NODE(hook), item));
349
350 NGI_GET_M(item, m);
351 /* Derive the softc we will need */
352 sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
353
354 /* If there is no live channel, throw it away */
355 if ((sc->downstream.hook == NULL)
356 || ((ctxp->flags & CHAN_ACTIVE) == 0)) {
357 error = ENETDOWN;
358 goto bad;
359 }
360
361 /* Store the DLCI on the front of the packet */
362 alen = sc->addrlen;
363 if (alen == 0)
364 alen = 2; /* default value for transmit */
365 M_PREPEND(m, alen, M_DONTWAIT);
366 if (m == NULL) {
367 error = ENOBUFS;
368 goto bad;
369 }
370 data = mtod(m, char *);
371
372 /*
373 * Shift the lowest bits into the address field untill we are done.
374 * First byte is MSBits of addr so work backwards.
375 */
376 switch (alen) {
377 case 2:
378 data[0] = data[1] = '\0';
379 SHIFTOUT(makeup + 1, data[1], dlci);
380 SHIFTOUT(makeup + 0, data[0], dlci);
381 data[1] |= BYTEX_EA;
382 break;
383 case 3:
384 data[0] = data[1] = data[2] = '\0';
385 SHIFTOUT(makeup + 3, data[2], dlci); /* 3 and 2 is correct */
386 SHIFTOUT(makeup + 1, data[1], dlci);
387 SHIFTOUT(makeup + 0, data[0], dlci);
388 data[2] |= BYTEX_EA;
389 break;
390 case 4:
391 data[0] = data[1] = data[2] = data[3] = '\0';
392 SHIFTOUT(makeup + 3, data[3], dlci);
393 SHIFTOUT(makeup + 2, data[2], dlci);
394 SHIFTOUT(makeup + 1, data[1], dlci);
395 SHIFTOUT(makeup + 0, data[0], dlci);
396 data[3] |= BYTEX_EA;
397 break;
398 default:
399 panic(__func__);
400 }
401
402 /* Send it */
403 NG_FWD_NEW_DATA(error, item, sc->downstream.hook, m);
404 return (error);
405
406bad:
407 NG_FREE_ITEM(item);
408 NG_FREE_M(m);
409 return (error);
410}
411
412/*
413 * Decode an incoming frame coming from the switch
414 */
415static int
416ngfrm_decode(node_p node, item_p item)
417{
418 const sc_p sc = NG_NODE_PRIVATE(node);
419 char *data;
420 int alen;
421 u_int dlci = 0;
422 int error = 0;
423 int ctxnum;
424 struct mbuf *m;
425
426 NGI_GET_M(item, m);
427 if (m->m_len < 4 && (m = m_pullup(m, 4)) == NULL) {
428 error = ENOBUFS;
429 goto out;
430 }
431 data = mtod(m, char *);
432 if ((alen = sc->addrlen) == 0) {
433 sc->addrlen = alen = ngfrm_addrlen(data);
434 }
435 switch (alen) {
436 case 2:
437 SHIFTIN(makeup + 0, data[0], dlci);
438 SHIFTIN(makeup + 1, data[1], dlci);
439 break;
440 case 3:
441 SHIFTIN(makeup + 0, data[0], dlci);
442 SHIFTIN(makeup + 1, data[1], dlci);
443 SHIFTIN(makeup + 3, data[2], dlci); /* 3 and 2 is correct */
444 break;
445 case 4:
446 SHIFTIN(makeup + 0, data[0], dlci);
447 SHIFTIN(makeup + 1, data[1], dlci);
448 SHIFTIN(makeup + 2, data[2], dlci);
449 SHIFTIN(makeup + 3, data[3], dlci);
450 break;
451 default:
452 error = EINVAL;
453 goto out;
454 }
455
456 if (dlci > 1023) {
457 error = EINVAL;
458 goto out;
459 }
460 ctxnum = sc->ALT[dlci];
461 if ((ctxnum & CTX_VALID) && sc->channel[ctxnum &= CTX_VALUE].hook) {
462 /* Send it */
463 m_adj(m, alen);
464 NG_FWD_NEW_DATA(error, item, sc->channel[ctxnum].hook, m);
465 return (error);
466 } else {
467 error = ENETDOWN;
468 }
469out:
470 NG_FREE_ITEM(item);
471 NG_FREE_M(m);
472 return (error);
473}
474
475/*
476 * Shutdown node
477 */
478static int
479ngfrm_shutdown(node_p node)
480{
481 const sc_p sc = NG_NODE_PRIVATE(node);
482
483 NG_NODE_SET_PRIVATE(node, NULL);
484 FREE(sc, M_NETGRAPH);
485 NG_NODE_UNREF(node);
486 return (0);
487}
488
489/*
490 * Hook disconnection
491 *
492 * Invalidate the private data associated with this dlci.
493 * For this type, removal of the last link resets tries to destroy the node.
494 */
495static int
496ngfrm_disconnect(hook_p hook)
497{
498 const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
499 struct ctxinfo *const cp = NG_HOOK_PRIVATE(hook);
500 int dlci;
501
502 /* If it's a regular dlci hook, then free resources etc.. */
503 if (cp != NULL) {
504 cp->hook = NULL;
505 dlci = cp->dlci;
506 if (dlci != -1)
507 sc->ALT[dlci] = 0;
508 cp->flags = 0;
509 sc->datahooks--;
510 }
511 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
512 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
513 ng_rmnode_self(NG_HOOK_NODE(hook));
514 return (0);
515}