5 * Copyright (c) 1996-1999 Whistle Communications, Inc.
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.
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
37 * Author: Julian Elisher <julian@freebsd.org>
39 * $FreeBSD: src/sys/netgraph/ng_frame_relay.c,v 1.9.2.2 2000/10/24 18:36:45 julian Exp $
40 * $DragonFly: src/sys/netgraph/frame_relay/ng_frame_relay.c,v 1.5 2005/02/17 13:59:59 joerg Exp $
41 * $Whistle: ng_frame_relay.c,v 1.20 1999/11/01 09:24:51 julian Exp $
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.
49 * It has a 'downstream' hook that goes to the line, and a
50 * hook for each DLCI (eg, 'dlci16').
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>
59 #include <sys/syslog.h>
60 #include <sys/ctype.h>
61 #include <machine/clock.h>
63 #include <netgraph/ng_message.h>
64 #include <netgraph/netgraph.h>
65 #include "ng_frame_relay.h"
68 * Line info, and status per channel.
70 struct ctxinfo { /* one per active hook */
72 #define CHAN_VALID 0x01 /* assigned to a channel */
73 #define CHAN_ACTIVE 0x02 /* bottom level active */
74 int dlci; /* the dlci assigned to this context */
75 hook_p hook; /* if there's a hook assigned.. */
78 #define MAX_CT 16 /* # of dlci's active at a time (POWER OF 2!) */
80 int unit; /* which card are we? */
81 int datahooks; /* number of data hooks attached */
82 node_p node; /* netgraph node */
83 int addrlen; /* address header length */
84 int flags; /* state */
86 u_char remote_seq; /* sequence number the remote sent */
87 u_char local_seq; /* sequence number the remote rcvd */
88 u_short ALT[1024]; /* map DLCIs to CTX */
89 #define CTX_VALID 0x8000 /* this bit means it's a valid CTX */
90 #define CTX_VALUE (MAX_CT - 1) /* mask for context part */
91 struct ctxinfo channel[MAX_CT];
92 struct ctxinfo downstream;
94 typedef struct frmrel_softc *sc_p;
96 #define BYTEX_EA 0x01 /* End Address. Always 0 on byte1 */
97 #define BYTE1_C_R 0x02
98 #define BYTE2_FECN 0x08 /* forwards congestion notification */
99 #define BYTE2_BECN 0x04 /* Backward congestion notification */
100 #define BYTE2_DE 0x02 /* Discard elligability */
101 #define LASTBYTE_D_C 0x02 /* last byte is dl_core or dlci info */
103 /* Used to do headers */
104 static struct segment {
115 #define SHIFTIN(segment, byte, dlci) \
117 (dlci) <<= (segment)->width; \
119 (((byte) & (segment)->mask) >> (segment)->shift); \
122 #define SHIFTOUT(segment, byte, dlci) \
124 (byte) |= (((dlci) << (segment)->shift) & (segment)->mask); \
125 (dlci) >>= (segment)->width; \
128 /* Netgraph methods */
129 static ng_constructor_t ngfrm_constructor;
130 static ng_shutdown_t ngfrm_rmnode;
131 static ng_newhook_t ngfrm_newhook;
132 static ng_rcvdata_t ngfrm_rcvdata;
133 static ng_disconnect_t ngfrm_disconnect;
135 /* Other internal functions */
136 static int ngfrm_decode(node_p node, struct mbuf * m, meta_p meta);
137 static int ngfrm_addrlen(char *hdr);
138 static int ngfrm_allocate_CTX(sc_p sc, int dlci);
141 static struct ng_type typestruct = {
143 NG_FRAMERELAY_NODE_TYPE,
156 NETGRAPH_INIT(framerelay, &typestruct);
159 * Given a DLCI, return the index of the context table entry for it,
160 * Allocating a new one if needs be, or -1 if none available.
163 ngfrm_allocate_CTX(sc_p sc, int dlci)
165 u_int ctxnum = -1; /* what ctx number we are using */
166 volatile struct ctxinfo *CTXp = NULL;
168 /* Sanity check the dlci value */
172 /* Check to see if we already have an entry for this DLCI */
174 if ((ctxnum = sc->ALT[dlci] & CTX_VALUE) < MAX_CT) {
175 CTXp = sc->channel + ctxnum;
178 sc->ALT[dlci] = 0; /* paranoid but... */
183 * If the index has no valid entry yet, then we need to allocate a
187 for (ctxnum = 0; ctxnum < MAX_CT; ctxnum++) {
189 * If the VALID flag is empty it is unused
191 if ((sc->channel[ctxnum].flags & CHAN_VALID) == 0) {
192 bzero(sc->channel + ctxnum,
193 sizeof(struct ctxinfo));
194 CTXp = sc->channel + ctxnum;
195 sc->ALT[dlci] = ctxnum | CTX_VALID;
196 sc->channel[ctxnum].dlci = dlci;
197 sc->channel[ctxnum].flags = CHAN_VALID;
204 * If we still don't have a CTX pointer, then we never found a free
205 * spot so give up now..
208 log(LOG_ERR, "No CTX available for dlci %d\n", dlci);
218 ngfrm_constructor(node_p *nodep)
223 MALLOC(sc, sc_p, sizeof(*sc), M_NETGRAPH, M_NOWAIT);
226 bzero(sc, sizeof(*sc));
227 if ((error = ng_make_node_common(&typestruct, nodep))) {
228 FREE(sc, M_NETGRAPH);
231 sc->addrlen = 2; /* default */
233 /* Link the node and our private info */
234 (*nodep)->private = sc;
242 * We allow hooks called "debug", "downstream" and dlci[0-1023]
243 * The hook's private info points to our stash of info about that
244 * channel. A NULL pointer is debug and a DLCI of -1 means downstream.
247 ngfrm_newhook(node_p node, hook_p hook, const char *name)
249 const sc_p sc = node->private;
255 /* Check if it's our friend the control hook */
256 if (strcmp(name, NG_FRAMERELAY_HOOK_DEBUG) == 0) {
257 hook->private = NULL; /* paranoid */
262 * All other hooks either start with 'dlci' and have a decimal
263 * trailing channel number up to 4 digits, or are the downstream
266 if (strncmp(name, NG_FRAMERELAY_HOOK_DLCI,
267 strlen(NG_FRAMERELAY_HOOK_DLCI)) != 0) {
269 /* It must be the downstream connection */
270 if (strcmp(name, NG_FRAMERELAY_HOOK_DOWNSTREAM) != 0)
273 /* Make sure we haven't already got one (paranoid) */
274 if (sc->downstream.hook)
278 hook->private = &sc->downstream;
279 sc->downstream.hook = hook;
280 sc->downstream.dlci = -1;
281 sc->downstream.flags |= CHAN_ACTIVE;
286 /* Must be a dlci hook at this point */
287 cp = name + strlen(NG_FRAMERELAY_HOOK_DLCI);
288 if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0'))
290 dlci = (int)strtoul(cp, &eptr, 10);
291 if (*eptr != '\0' || dlci < 0 || dlci > 1023)
295 * We have a dlci, now either find it, or allocate it. It's possible
296 * that we might have seen packets for it already and made an entry
299 ctxnum = ngfrm_allocate_CTX(sc, dlci);
304 * Be paranoid: if it's got a hook already, that dlci is in use .
305 * Generic code can not catch all the synonyms (e.g. dlci016 vs
308 if (sc->channel[ctxnum].hook != NULL)
312 * Put our hooks into it (pun not intended)
314 sc->channel[ctxnum].flags |= CHAN_ACTIVE;
315 hook->private = sc->channel + ctxnum;
316 sc->channel[ctxnum].hook = hook;
322 * Count up the size of the address header if we don't already know
325 ngfrm_addrlen(char *hdr)
327 if (hdr[0] & BYTEX_EA)
329 if (hdr[1] & BYTEX_EA)
331 if (hdr[2] & BYTEX_EA)
333 if (hdr[3] & BYTEX_EA)
339 * Receive data packet
342 ngfrm_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
344 struct ctxinfo *const ctxp = hook->private;
351 /* Data doesn't come in from just anywhere (e.g debug hook) */
357 /* If coming from downstream, decode it to a channel */
360 return (ngfrm_decode(hook->node, m, meta));
362 /* Derive the softc we will need */
363 sc = hook->node->private;
365 /* If there is no live channel, throw it away */
366 if ((sc->downstream.hook == NULL)
367 || ((ctxp->flags & CHAN_ACTIVE) == 0)) {
372 /* Store the DLCI on the front of the packet */
375 alen = 2; /* default value for transmit */
376 M_PREPEND(m, alen, MB_DONTWAIT);
381 data = mtod(m, char *);
384 * Shift the lowest bits into the address field untill we are done.
385 * First byte is MSBits of addr so work backwards.
389 data[0] = data[1] = '\0';
390 SHIFTOUT(makeup + 1, data[1], dlci);
391 SHIFTOUT(makeup + 0, data[0], dlci);
395 data[0] = data[1] = data[2] = '\0';
396 SHIFTOUT(makeup + 3, data[2], dlci); /* 3 and 2 is correct */
397 SHIFTOUT(makeup + 1, data[1], dlci);
398 SHIFTOUT(makeup + 0, data[0], dlci);
402 data[0] = data[1] = data[2] = data[3] = '\0';
403 SHIFTOUT(makeup + 3, data[3], dlci);
404 SHIFTOUT(makeup + 2, data[2], dlci);
405 SHIFTOUT(makeup + 1, data[1], dlci);
406 SHIFTOUT(makeup + 0, data[0], dlci);
414 NG_SEND_DATA(error, sc->downstream.hook, m, meta);
418 NG_FREE_DATA(m, meta);
423 * Decode an incoming frame coming from the switch
426 ngfrm_decode(node_p node, struct mbuf *m, meta_p meta)
428 const sc_p sc = node->private;
435 if (m->m_len < 4 && (m = m_pullup(m, 4)) == NULL) {
439 data = mtod(m, char *);
440 if ((alen = sc->addrlen) == 0) {
441 sc->addrlen = alen = ngfrm_addrlen(data);
445 SHIFTIN(makeup + 0, data[0], dlci);
446 SHIFTIN(makeup + 1, data[1], dlci);
449 SHIFTIN(makeup + 0, data[0], dlci);
450 SHIFTIN(makeup + 1, data[1], dlci);
451 SHIFTIN(makeup + 3, data[2], dlci); /* 3 and 2 is correct */
454 SHIFTIN(makeup + 0, data[0], dlci);
455 SHIFTIN(makeup + 1, data[1], dlci);
456 SHIFTIN(makeup + 2, data[2], dlci);
457 SHIFTIN(makeup + 3, data[3], dlci);
468 ctxnum = sc->ALT[dlci];
469 if ((ctxnum & CTX_VALID) && sc->channel[ctxnum &= CTX_VALUE].hook) {
472 NG_SEND_DATA(error, sc->channel[ctxnum].hook, m, meta);
478 NG_FREE_DATA(m, meta);
486 ngfrm_rmnode(node_p node)
488 const sc_p sc = node->private;
490 node->flags |= NG_INVALID;
493 node->private = NULL;
494 FREE(sc, M_NETGRAPH);
502 * Invalidate the private data associated with this dlci.
503 * For this type, removal of the last link resets tries to destroy the node.
506 ngfrm_disconnect(hook_p hook)
508 const sc_p sc = hook->node->private;
509 struct ctxinfo *const cp = hook->private;
512 /* If it's a regular dlci hook, then free resources etc.. */
521 if (hook->node->numhooks == 0)
522 ng_rmnode(hook->node);