FreeBSD/Linux Kernel Cross Reference
sys/netgraph/ng_ppp.c
1 /*
2 * ng_ppp.c
3 */
4
5 /*-
6 * Copyright (c) 1996-2000 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: Archie Cobbs <archie@freebsd.org>
39 *
40 * $FreeBSD: src/sys/netgraph/ng_ppp.c,v 1.51.2.3 2005/01/31 23:26:29 imp Exp $
41 * $Whistle: ng_ppp.c,v 1.24 1999/11/01 09:24:52 julian Exp $
42 */
43
44 /*
45 * PPP node type.
46 */
47
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/kernel.h>
51 #include <sys/limits.h>
52 #include <sys/time.h>
53 #include <sys/mbuf.h>
54 #include <sys/malloc.h>
55 #include <sys/errno.h>
56 #include <sys/ctype.h>
57
58 #include <netgraph/ng_message.h>
59 #include <netgraph/netgraph.h>
60 #include <netgraph/ng_parse.h>
61 #include <netgraph/ng_ppp.h>
62 #include <netgraph/ng_vjc.h>
63
64 #ifdef NG_SEPARATE_MALLOC
65 MALLOC_DEFINE(M_NETGRAPH_PPP, "netgraph_ppp", "netgraph ppp node");
66 #else
67 #define M_NETGRAPH_PPP M_NETGRAPH
68 #endif
69
70 #define PROT_VALID(p) (((p) & 0x0101) == 0x0001)
71 #define PROT_COMPRESSABLE(p) (((p) & 0xff00) == 0x0000)
72
73 /* Some PPP protocol numbers we're interested in */
74 #define PROT_APPLETALK 0x0029
75 #define PROT_COMPD 0x00fd
76 #define PROT_CRYPTD 0x0053
77 #define PROT_IP 0x0021
78 #define PROT_IPV6 0x0057
79 #define PROT_IPX 0x002b
80 #define PROT_LCP 0xc021
81 #define PROT_MP 0x003d
82 #define PROT_VJCOMP 0x002d
83 #define PROT_VJUNCOMP 0x002f
84
85 /* Multilink PPP definitions */
86 #define MP_MIN_MRRU 1500 /* per RFC 1990 */
87 #define MP_INITIAL_SEQ 0 /* per RFC 1990 */
88 #define MP_MIN_LINK_MRU 32
89
90 #define MP_SHORT_SEQ_MASK 0x00000fff /* short seq # mask */
91 #define MP_SHORT_SEQ_HIBIT 0x00000800 /* short seq # high bit */
92 #define MP_SHORT_FIRST_FLAG 0x00008000 /* first fragment in frame */
93 #define MP_SHORT_LAST_FLAG 0x00004000 /* last fragment in frame */
94
95 #define MP_LONG_SEQ_MASK 0x00ffffff /* long seq # mask */
96 #define MP_LONG_SEQ_HIBIT 0x00800000 /* long seq # high bit */
97 #define MP_LONG_FIRST_FLAG 0x80000000 /* first fragment in frame */
98 #define MP_LONG_LAST_FLAG 0x40000000 /* last fragment in frame */
99
100 #define MP_NOSEQ 0x7fffffff /* impossible sequence number */
101
102 /* Sign extension of MP sequence numbers */
103 #define MP_SHORT_EXTEND(s) (((s) & MP_SHORT_SEQ_HIBIT) ? \
104 ((s) | ~MP_SHORT_SEQ_MASK) \
105 : ((s) & MP_SHORT_SEQ_MASK))
106 #define MP_LONG_EXTEND(s) (((s) & MP_LONG_SEQ_HIBIT) ? \
107 ((s) | ~MP_LONG_SEQ_MASK) \
108 : ((s) & MP_LONG_SEQ_MASK))
109
110 /* Comparision of MP sequence numbers. Note: all sequence numbers
111 except priv->xseq are stored with the sign bit extended. */
112 #define MP_SHORT_SEQ_DIFF(x,y) MP_SHORT_EXTEND((x) - (y))
113 #define MP_LONG_SEQ_DIFF(x,y) MP_LONG_EXTEND((x) - (y))
114
115 #define MP_RECV_SEQ_DIFF(priv,x,y) \
116 ((priv)->conf.recvShortSeq ? \
117 MP_SHORT_SEQ_DIFF((x), (y)) : \
118 MP_LONG_SEQ_DIFF((x), (y)))
119
120 /* Increment receive sequence number */
121 #define MP_NEXT_RECV_SEQ(priv,seq) \
122 ((priv)->conf.recvShortSeq ? \
123 MP_SHORT_EXTEND((seq) + 1) : \
124 MP_LONG_EXTEND((seq) + 1))
125
126 /* Don't fragment transmitted packets smaller than this */
127 #define MP_MIN_FRAG_LEN 6
128
129 /* Maximum fragment reasssembly queue length */
130 #define MP_MAX_QUEUE_LEN 128
131
132 /* Fragment queue scanner period */
133 #define MP_FRAGTIMER_INTERVAL (hz/2)
134
135 /* We store incoming fragments this way */
136 struct ng_ppp_frag {
137 int seq; /* fragment seq# */
138 u_char first; /* First in packet? */
139 u_char last; /* Last in packet? */
140 struct timeval timestamp; /* time of reception */
141 struct mbuf *data; /* Fragment data */
142 TAILQ_ENTRY(ng_ppp_frag) f_qent; /* Fragment queue */
143 };
144
145 /* We use integer indicies to refer to the non-link hooks */
146 static const char *const ng_ppp_hook_names[] = {
147 NG_PPP_HOOK_ATALK,
148 #define HOOK_INDEX_ATALK 0
149 NG_PPP_HOOK_BYPASS,
150 #define HOOK_INDEX_BYPASS 1
151 NG_PPP_HOOK_COMPRESS,
152 #define HOOK_INDEX_COMPRESS 2
153 NG_PPP_HOOK_ENCRYPT,
154 #define HOOK_INDEX_ENCRYPT 3
155 NG_PPP_HOOK_DECOMPRESS,
156 #define HOOK_INDEX_DECOMPRESS 4
157 NG_PPP_HOOK_DECRYPT,
158 #define HOOK_INDEX_DECRYPT 5
159 NG_PPP_HOOK_INET,
160 #define HOOK_INDEX_INET 6
161 NG_PPP_HOOK_IPX,
162 #define HOOK_INDEX_IPX 7
163 NG_PPP_HOOK_VJC_COMP,
164 #define HOOK_INDEX_VJC_COMP 8
165 NG_PPP_HOOK_VJC_IP,
166 #define HOOK_INDEX_VJC_IP 9
167 NG_PPP_HOOK_VJC_UNCOMP,
168 #define HOOK_INDEX_VJC_UNCOMP 10
169 NG_PPP_HOOK_VJC_VJIP,
170 #define HOOK_INDEX_VJC_VJIP 11
171 NG_PPP_HOOK_IPV6,
172 #define HOOK_INDEX_IPV6 12
173 NULL
174 #define HOOK_INDEX_MAX 13
175 };
176
177 /* We store index numbers in the hook private pointer. The HOOK_INDEX()
178 for a hook is either the index (above) for normal hooks, or the ones
179 complement of the link number for link hooks.
180 XXX Not any more.. (what a hack)
181 #define HOOK_INDEX(hook) (*((int16_t *) &(hook)->private))
182 */
183
184 /* Per-link private information */
185 struct ng_ppp_link {
186 struct ng_ppp_link_conf conf; /* link configuration */
187 hook_p hook; /* connection to link data */
188 int32_t seq; /* highest rec'd seq# - MSEQ */
189 u_int32_t latency; /* calculated link latency */
190 struct timeval lastWrite; /* time of last write */
191 int bytesInQueue; /* bytes in the output queue */
192 struct ng_ppp_link_stat stats; /* Link stats */
193 };
194
195 /* Total per-node private information */
196 struct ng_ppp_private {
197 struct ng_ppp_bund_conf conf; /* bundle config */
198 struct ng_ppp_link_stat bundleStats; /* bundle stats */
199 struct ng_ppp_link links[NG_PPP_MAX_LINKS];/* per-link info */
200 int32_t xseq; /* next out MP seq # */
201 int32_t mseq; /* min links[i].seq */
202 u_char vjCompHooked; /* VJ comp hooked up? */
203 u_char allLinksEqual; /* all xmit the same? */
204 u_int numActiveLinks; /* how many links up */
205 int activeLinks[NG_PPP_MAX_LINKS]; /* indicies */
206 u_int lastLink; /* for round robin */
207 hook_p hooks[HOOK_INDEX_MAX]; /* non-link hooks */
208 TAILQ_HEAD(ng_ppp_fraglist, ng_ppp_frag) /* fragment queue */
209 frags;
210 int qlen; /* fraq queue length */
211 struct callout fragTimer; /* fraq queue check */
212 };
213 typedef struct ng_ppp_private *priv_p;
214
215 /* Netgraph node methods */
216 static ng_constructor_t ng_ppp_constructor;
217 static ng_rcvmsg_t ng_ppp_rcvmsg;
218 static ng_shutdown_t ng_ppp_shutdown;
219 static ng_newhook_t ng_ppp_newhook;
220 static ng_rcvdata_t ng_ppp_rcvdata;
221 static ng_disconnect_t ng_ppp_disconnect;
222
223 /* Helper functions */
224 static int ng_ppp_input(node_p node, int bypass,
225 int linkNum, item_p item);
226 static int ng_ppp_output(node_p node, int bypass, int proto,
227 int linkNum, item_p item);
228 static int ng_ppp_mp_input(node_p node, int linkNum, item_p item);
229 static int ng_ppp_check_packet(node_p node);
230 static void ng_ppp_get_packet(node_p node, struct mbuf **mp);
231 static int ng_ppp_frag_process(node_p node);
232 static int ng_ppp_frag_trim(node_p node);
233 static void ng_ppp_frag_timeout(node_p node, hook_p hook, void *arg1,
234 int arg2);
235 static void ng_ppp_frag_checkstale(node_p node);
236 static void ng_ppp_frag_reset(node_p node);
237 static int ng_ppp_mp_output(node_p node, struct mbuf *m);
238 static void ng_ppp_mp_strategy(node_p node, int len, int *distrib);
239 static int ng_ppp_intcmp(void *latency, const void *v1, const void *v2);
240 static struct mbuf *ng_ppp_addproto(struct mbuf *m, int proto, int compOK);
241 static struct mbuf *ng_ppp_prepend(struct mbuf *m, const void *buf, int len);
242 static int ng_ppp_config_valid(node_p node,
243 const struct ng_ppp_node_conf *newConf);
244 static void ng_ppp_update(node_p node, int newConf);
245 static void ng_ppp_start_frag_timer(node_p node);
246 static void ng_ppp_stop_frag_timer(node_p node);
247
248 /* Parse type for struct ng_ppp_mp_state_type */
249 static const struct ng_parse_fixedarray_info ng_ppp_rseq_array_info = {
250 &ng_parse_hint32_type,
251 NG_PPP_MAX_LINKS
252 };
253 static const struct ng_parse_type ng_ppp_rseq_array_type = {
254 &ng_parse_fixedarray_type,
255 &ng_ppp_rseq_array_info,
256 };
257 static const struct ng_parse_struct_field ng_ppp_mp_state_type_fields[]
258 = NG_PPP_MP_STATE_TYPE_INFO(&ng_ppp_rseq_array_type);
259 static const struct ng_parse_type ng_ppp_mp_state_type = {
260 &ng_parse_struct_type,
261 &ng_ppp_mp_state_type_fields
262 };
263
264 /* Parse type for struct ng_ppp_link_conf */
265 static const struct ng_parse_struct_field ng_ppp_link_type_fields[]
266 = NG_PPP_LINK_TYPE_INFO;
267 static const struct ng_parse_type ng_ppp_link_type = {
268 &ng_parse_struct_type,
269 &ng_ppp_link_type_fields
270 };
271
272 /* Parse type for struct ng_ppp_bund_conf */
273 static const struct ng_parse_struct_field ng_ppp_bund_type_fields[]
274 = NG_PPP_BUND_TYPE_INFO;
275 static const struct ng_parse_type ng_ppp_bund_type = {
276 &ng_parse_struct_type,
277 &ng_ppp_bund_type_fields
278 };
279
280 /* Parse type for struct ng_ppp_node_conf */
281 static const struct ng_parse_fixedarray_info ng_ppp_array_info = {
282 &ng_ppp_link_type,
283 NG_PPP_MAX_LINKS
284 };
285 static const struct ng_parse_type ng_ppp_link_array_type = {
286 &ng_parse_fixedarray_type,
287 &ng_ppp_array_info,
288 };
289 static const struct ng_parse_struct_field ng_ppp_conf_type_fields[]
290 = NG_PPP_CONFIG_TYPE_INFO(&ng_ppp_bund_type, &ng_ppp_link_array_type);
291 static const struct ng_parse_type ng_ppp_conf_type = {
292 &ng_parse_struct_type,
293 &ng_ppp_conf_type_fields
294 };
295
296 /* Parse type for struct ng_ppp_link_stat */
297 static const struct ng_parse_struct_field ng_ppp_stats_type_fields[]
298 = NG_PPP_STATS_TYPE_INFO;
299 static const struct ng_parse_type ng_ppp_stats_type = {
300 &ng_parse_struct_type,
301 &ng_ppp_stats_type_fields
302 };
303
304 /* List of commands and how to convert arguments to/from ASCII */
305 static const struct ng_cmdlist ng_ppp_cmds[] = {
306 {
307 NGM_PPP_COOKIE,
308 NGM_PPP_SET_CONFIG,
309 "setconfig",
310 &ng_ppp_conf_type,
311 NULL
312 },
313 {
314 NGM_PPP_COOKIE,
315 NGM_PPP_GET_CONFIG,
316 "getconfig",
317 NULL,
318 &ng_ppp_conf_type
319 },
320 {
321 NGM_PPP_COOKIE,
322 NGM_PPP_GET_MP_STATE,
323 "getmpstate",
324 NULL,
325 &ng_ppp_mp_state_type
326 },
327 {
328 NGM_PPP_COOKIE,
329 NGM_PPP_GET_LINK_STATS,
330 "getstats",
331 &ng_parse_int16_type,
332 &ng_ppp_stats_type
333 },
334 {
335 NGM_PPP_COOKIE,
336 NGM_PPP_CLR_LINK_STATS,
337 "clrstats",
338 &ng_parse_int16_type,
339 NULL
340 },
341 {
342 NGM_PPP_COOKIE,
343 NGM_PPP_GETCLR_LINK_STATS,
344 "getclrstats",
345 &ng_parse_int16_type,
346 &ng_ppp_stats_type
347 },
348 { 0 }
349 };
350
351 /* Node type descriptor */
352 static struct ng_type ng_ppp_typestruct = {
353 .version = NG_ABI_VERSION,
354 .name = NG_PPP_NODE_TYPE,
355 .constructor = ng_ppp_constructor,
356 .rcvmsg = ng_ppp_rcvmsg,
357 .shutdown = ng_ppp_shutdown,
358 .newhook = ng_ppp_newhook,
359 .rcvdata = ng_ppp_rcvdata,
360 .disconnect = ng_ppp_disconnect,
361 .cmdlist = ng_ppp_cmds,
362 };
363 NETGRAPH_INIT(ppp, &ng_ppp_typestruct);
364
365 /* Address and control field header */
366 static const u_char ng_ppp_acf[2] = { 0xff, 0x03 };
367
368 /* Maximum time we'll let a complete incoming packet sit in the queue */
369 static const struct timeval ng_ppp_max_staleness = { 2, 0 }; /* 2 seconds */
370
371 #define ERROUT(x) do { error = (x); goto done; } while (0)
372
373 /************************************************************************
374 NETGRAPH NODE STUFF
375 ************************************************************************/
376
377 /*
378 * Node type constructor
379 */
380 static int
381 ng_ppp_constructor(node_p node)
382 {
383 priv_p priv;
384 int i;
385
386 /* Allocate private structure */
387 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH_PPP, M_NOWAIT | M_ZERO);
388 if (priv == NULL)
389 return (ENOMEM);
390
391 NG_NODE_SET_PRIVATE(node, priv);
392
393 /* Initialize state */
394 TAILQ_INIT(&priv->frags);
395 for (i = 0; i < NG_PPP_MAX_LINKS; i++)
396 priv->links[i].seq = MP_NOSEQ;
397 ng_callout_init(&priv->fragTimer);
398
399 /* Done */
400 return (0);
401 }
402
403 /*
404 * Give our OK for a hook to be added
405 */
406 static int
407 ng_ppp_newhook(node_p node, hook_p hook, const char *name)
408 {
409 const priv_p priv = NG_NODE_PRIVATE(node);
410 int linkNum = -1;
411 hook_p *hookPtr = NULL;
412 int hookIndex = -1;
413
414 /* Figure out which hook it is */
415 if (strncmp(name, NG_PPP_HOOK_LINK_PREFIX, /* a link hook? */
416 strlen(NG_PPP_HOOK_LINK_PREFIX)) == 0) {
417 const char *cp;
418 char *eptr;
419
420 cp = name + strlen(NG_PPP_HOOK_LINK_PREFIX);
421 if (!isdigit(*cp) || (cp[0] == '' && cp[1] != '\0'))
422 return (EINVAL);
423 linkNum = (int)strtoul(cp, &eptr, 10);
424 if (*eptr != '\0' || linkNum < 0 || linkNum >= NG_PPP_MAX_LINKS)
425 return (EINVAL);
426 hookPtr = &priv->links[linkNum].hook;
427 hookIndex = ~linkNum;
428 } else { /* must be a non-link hook */
429 int i;
430
431 for (i = 0; ng_ppp_hook_names[i] != NULL; i++) {
432 if (strcmp(name, ng_ppp_hook_names[i]) == 0) {
433 hookPtr = &priv->hooks[i];
434 hookIndex = i;
435 break;
436 }
437 }
438 if (ng_ppp_hook_names[i] == NULL)
439 return (EINVAL); /* no such hook */
440 }
441
442 /* See if hook is already connected */
443 if (*hookPtr != NULL)
444 return (EISCONN);
445
446 /* Disallow more than one link unless multilink is enabled */
447 if (linkNum != -1 && priv->links[linkNum].conf.enableLink
448 && !priv->conf.enableMultilink && priv->numActiveLinks >= 1)
449 return (ENODEV);
450
451 /* OK */
452 *hookPtr = hook;
453 NG_HOOK_SET_PRIVATE(hook, (void *)(intptr_t)hookIndex);
454 ng_ppp_update(node, 0);
455 return (0);
456 }
457
458 /*
459 * Receive a control message
460 */
461 static int
462 ng_ppp_rcvmsg(node_p node, item_p item, hook_p lasthook)
463 {
464 const priv_p priv = NG_NODE_PRIVATE(node);
465 struct ng_mesg *resp = NULL;
466 int error = 0;
467 struct ng_mesg *msg;
468
469 NGI_GET_MSG(item, msg);
470 switch (msg->header.typecookie) {
471 case NGM_PPP_COOKIE:
472 switch (msg->header.cmd) {
473 case NGM_PPP_SET_CONFIG:
474 {
475 struct ng_ppp_node_conf *const conf =
476 (struct ng_ppp_node_conf *)msg->data;
477 int i;
478
479 /* Check for invalid or illegal config */
480 if (msg->header.arglen != sizeof(*conf))
481 ERROUT(EINVAL);
482 if (!ng_ppp_config_valid(node, conf))
483 ERROUT(EINVAL);
484
485 /* Copy config */
486 priv->conf = conf->bund;
487 for (i = 0; i < NG_PPP_MAX_LINKS; i++)
488 priv->links[i].conf = conf->links[i];
489 ng_ppp_update(node, 1);
490 break;
491 }
492 case NGM_PPP_GET_CONFIG:
493 {
494 struct ng_ppp_node_conf *conf;
495 int i;
496
497 NG_MKRESPONSE(resp, msg, sizeof(*conf), M_NOWAIT);
498 if (resp == NULL)
499 ERROUT(ENOMEM);
500 conf = (struct ng_ppp_node_conf *)resp->data;
501 conf->bund = priv->conf;
502 for (i = 0; i < NG_PPP_MAX_LINKS; i++)
503 conf->links[i] = priv->links[i].conf;
504 break;
505 }
506 case NGM_PPP_GET_MP_STATE:
507 {
508 struct ng_ppp_mp_state *info;
509 int i;
510
511 NG_MKRESPONSE(resp, msg, sizeof(*info), M_NOWAIT);
512 if (resp == NULL)
513 ERROUT(ENOMEM);
514 info = (struct ng_ppp_mp_state *)resp->data;
515 bzero(info, sizeof(*info));
516 for (i = 0; i < NG_PPP_MAX_LINKS; i++) {
517 if (priv->links[i].seq != MP_NOSEQ)
518 info->rseq[i] = priv->links[i].seq;
519 }
520 info->mseq = priv->mseq;
521 info->xseq = priv->xseq;
522 break;
523 }
524 case NGM_PPP_GET_LINK_STATS:
525 case NGM_PPP_CLR_LINK_STATS:
526 case NGM_PPP_GETCLR_LINK_STATS:
527 {
528 struct ng_ppp_link_stat *stats;
529 u_int16_t linkNum;
530
531 if (msg->header.arglen != sizeof(u_int16_t))
532 ERROUT(EINVAL);
533 linkNum = *((u_int16_t *) msg->data);
534 if (linkNum >= NG_PPP_MAX_LINKS
535 && linkNum != NG_PPP_BUNDLE_LINKNUM)
536 ERROUT(EINVAL);
537 stats = (linkNum == NG_PPP_BUNDLE_LINKNUM) ?
538 &priv->bundleStats : &priv->links[linkNum].stats;
539 if (msg->header.cmd != NGM_PPP_CLR_LINK_STATS) {
540 NG_MKRESPONSE(resp, msg,
541 sizeof(struct ng_ppp_link_stat), M_NOWAIT);
542 if (resp == NULL)
543 ERROUT(ENOMEM);
544 bcopy(stats, resp->data, sizeof(*stats));
545 }
546 if (msg->header.cmd != NGM_PPP_GET_LINK_STATS)
547 bzero(stats, sizeof(*stats));
548 break;
549 }
550 default:
551 error = EINVAL;
552 break;
553 }
554 break;
555 case NGM_VJC_COOKIE:
556 {
557 /*
558 * Forward it to the vjc node. leave the
559 * old return address alone.
560 * If we have no hook, let NG_RESPOND_MSG
561 * clean up any remaining resources.
562 * Because we have no resp, the item will be freed
563 * along with anything it references. Don't
564 * let msg be freed twice.
565 */
566 NGI_MSG(item) = msg; /* put it back in the item */
567 msg = NULL;
568 if ((lasthook = priv->links[HOOK_INDEX_VJC_IP].hook)) {
569 NG_FWD_ITEM_HOOK(error, item, lasthook);
570 }
571 return (error);
572 }
573 default:
574 error = EINVAL;
575 break;
576 }
577 done:
578 NG_RESPOND_MSG(error, node, item, resp);
579 NG_FREE_MSG(msg);
580 return (error);
581 }
582
583 /*
584 * Receive data on a hook
585 */
586 static int
587 ng_ppp_rcvdata(hook_p hook, item_p item)
588 {
589 const node_p node = NG_HOOK_NODE(hook);
590 const priv_p priv = NG_NODE_PRIVATE(node);
591 const int index = (intptr_t)NG_HOOK_PRIVATE(hook);
592 u_int16_t linkNum = NG_PPP_BUNDLE_LINKNUM;
593 hook_p outHook = NULL;
594 int proto = 0, error;
595 struct mbuf *m;
596
597 NGI_GET_M(item, m);
598 /* Did it come from a link hook? */
599 if (index < 0) {
600 struct ng_ppp_link *link;
601
602 /* Convert index into a link number */
603 linkNum = (u_int16_t)~index;
604 KASSERT(linkNum < NG_PPP_MAX_LINKS,
605 ("%s: bogus index 0x%x", __func__, index));
606 link = &priv->links[linkNum];
607
608 /* Stats */
609 link->stats.recvFrames++;
610 link->stats.recvOctets += m->m_pkthdr.len;
611
612 /* Strip address and control fields, if present */
613 if (m->m_pkthdr.len >= 2) {
614 if (m->m_len < 2 && (m = m_pullup(m, 2)) == NULL) {
615 NG_FREE_ITEM(item);
616 return (ENOBUFS);
617 }
618 if (bcmp(mtod(m, u_char *), &ng_ppp_acf, 2) == 0)
619 m_adj(m, 2);
620 }
621
622 /* Dispatch incoming frame (if not enabled, to bypass) */
623 NGI_M(item) = m; /* put changed m back in item */
624 return ng_ppp_input(node,
625 !link->conf.enableLink, linkNum, item);
626 }
627
628 /* Get protocol & check if data allowed from this hook */
629 NGI_M(item) = m; /* put possibly changed m back in item */
630 switch (index) {
631
632 /* Outgoing data */
633 case HOOK_INDEX_ATALK:
634 if (!priv->conf.enableAtalk) {
635 NG_FREE_ITEM(item);
636 return (ENXIO);
637 }
638 proto = PROT_APPLETALK;
639 break;
640 case HOOK_INDEX_IPX:
641 if (!priv->conf.enableIPX) {
642 NG_FREE_ITEM(item);
643 return (ENXIO);
644 }
645 proto = PROT_IPX;
646 break;
647 case HOOK_INDEX_IPV6:
648 if (!priv->conf.enableIPv6) {
649 NG_FREE_ITEM(item);
650 return (ENXIO);
651 }
652 proto = PROT_IPV6;
653 break;
654 case HOOK_INDEX_INET:
655 case HOOK_INDEX_VJC_VJIP:
656 if (!priv->conf.enableIP) {
657 NG_FREE_ITEM(item);
658 return (ENXIO);
659 }
660 proto = PROT_IP;
661 break;
662 case HOOK_INDEX_VJC_COMP:
663 if (!priv->conf.enableVJCompression) {
664 NG_FREE_ITEM(item);
665 return (ENXIO);
666 }
667 proto = PROT_VJCOMP;
668 break;
669 case HOOK_INDEX_VJC_UNCOMP:
670 if (!priv->conf.enableVJCompression) {
671 NG_FREE_ITEM(item);
672 return (ENXIO);
673 }
674 proto = PROT_VJUNCOMP;
675 break;
676 case HOOK_INDEX_COMPRESS:
677 if (!priv->conf.enableCompression) {
678 NG_FREE_ITEM(item);
679 return (ENXIO);
680 }
681 proto = PROT_COMPD;
682 break;
683 case HOOK_INDEX_ENCRYPT:
684 if (!priv->conf.enableEncryption) {
685 NG_FREE_ITEM(item);
686 return (ENXIO);
687 }
688 proto = PROT_CRYPTD;
689 break;
690 case HOOK_INDEX_BYPASS:
691 if (m->m_pkthdr.len < 4) {
692 NG_FREE_ITEM(item);
693 return (EINVAL);
694 }
695 if (m->m_len < 4 && (m = m_pullup(m, 4)) == NULL) {
696 NGI_M(item) = NULL; /* don't free twice */
697 NG_FREE_ITEM(item);
698 return (ENOBUFS);
699 }
700 NGI_M(item) = m; /* m may have changed */
701 linkNum = ntohs(mtod(m, u_int16_t *)[0]);
702 proto = ntohs(mtod(m, u_int16_t *)[1]);
703 m_adj(m, 4);
704 if (linkNum >= NG_PPP_MAX_LINKS
705 && linkNum != NG_PPP_BUNDLE_LINKNUM) {
706 NG_FREE_ITEM(item);
707 return (EINVAL);
708 }
709 break;
710
711 /* Incoming data */
712 case HOOK_INDEX_VJC_IP:
713 if (!priv->conf.enableIP || !priv->conf.enableVJDecompression) {
714 NG_FREE_ITEM(item);
715 return (ENXIO);
716 }
717 break;
718 case HOOK_INDEX_DECOMPRESS:
719 if (!priv->conf.enableDecompression) {
720 NG_FREE_ITEM(item);
721 return (ENXIO);
722 }
723 break;
724 case HOOK_INDEX_DECRYPT:
725 if (!priv->conf.enableDecryption) {
726 NG_FREE_ITEM(item);
727 return (ENXIO);
728 }
729 break;
730 default:
731 panic("%s: bogus index 0x%x", __func__, index);
732 }
733
734 /* Now figure out what to do with the frame */
735 switch (index) {
736
737 /* Outgoing data */
738 case HOOK_INDEX_INET:
739 if (priv->conf.enableVJCompression && priv->vjCompHooked) {
740 outHook = priv->hooks[HOOK_INDEX_VJC_IP];
741 break;
742 }
743 /* FALLTHROUGH */
744 case HOOK_INDEX_ATALK:
745 case HOOK_INDEX_IPV6:
746 case HOOK_INDEX_IPX:
747 case HOOK_INDEX_VJC_COMP:
748 case HOOK_INDEX_VJC_UNCOMP:
749 case HOOK_INDEX_VJC_VJIP:
750 if (priv->conf.enableCompression
751 && priv->hooks[HOOK_INDEX_COMPRESS] != NULL) {
752 if ((m = ng_ppp_addproto(m, proto, 0)) == NULL) {
753 NGI_M(item) = NULL;
754 NG_FREE_ITEM(item);
755 return (ENOBUFS);
756 }
757 NGI_M(item) = m; /* m may have changed */
758 outHook = priv->hooks[HOOK_INDEX_COMPRESS];
759 break;
760 }
761 /* FALLTHROUGH */
762 case HOOK_INDEX_COMPRESS:
763 if (priv->conf.enableEncryption
764 && priv->hooks[HOOK_INDEX_ENCRYPT] != NULL) {
765 if ((m = ng_ppp_addproto(m, proto, 1)) == NULL) {
766 NGI_M(item) = NULL;
767 NG_FREE_ITEM(item);
768 return (ENOBUFS);
769 }
770 NGI_M(item) = m; /* m may have changed */
771 outHook = priv->hooks[HOOK_INDEX_ENCRYPT];
772 break;
773 }
774 /* FALLTHROUGH */
775 case HOOK_INDEX_ENCRYPT:
776 return ng_ppp_output(node, 0, proto, NG_PPP_BUNDLE_LINKNUM, item);
777
778 case HOOK_INDEX_BYPASS:
779 return ng_ppp_output(node, 1, proto, linkNum, item);
780
781 /* Incoming data */
782 case HOOK_INDEX_DECRYPT:
783 case HOOK_INDEX_DECOMPRESS:
784 return ng_ppp_input(node, 0, NG_PPP_BUNDLE_LINKNUM, item);
785
786 case HOOK_INDEX_VJC_IP:
787 outHook = priv->hooks[HOOK_INDEX_INET];
788 break;
789 }
790
791 /* Send packet out hook */
792 NG_FWD_ITEM_HOOK(error, item, outHook);
793 return (error);
794 }
795
796 /*
797 * Destroy node
798 */
799 static int
800 ng_ppp_shutdown(node_p node)
801 {
802 const priv_p priv = NG_NODE_PRIVATE(node);
803
804 /* Stop fragment queue timer */
805 ng_ppp_stop_frag_timer(node);
806
807 /* Take down netgraph node */
808 ng_ppp_frag_reset(node);
809 bzero(priv, sizeof(*priv));
810 FREE(priv, M_NETGRAPH_PPP);
811 NG_NODE_SET_PRIVATE(node, NULL);
812 NG_NODE_UNREF(node); /* let the node escape */
813 return (0);
814 }
815
816 /*
817 * Hook disconnection
818 */
819 static int
820 ng_ppp_disconnect(hook_p hook)
821 {
822 const node_p node = NG_HOOK_NODE(hook);
823 const priv_p priv = NG_NODE_PRIVATE(node);
824 const int index = (intptr_t)NG_HOOK_PRIVATE(hook);
825
826 /* Zero out hook pointer */
827 if (index < 0)
828 priv->links[~index].hook = NULL;
829 else
830 priv->hooks[index] = NULL;
831
832 /* Update derived info (or go away if no hooks left) */
833 if (NG_NODE_NUMHOOKS(node) > 0) {
834 ng_ppp_update(node, 0);
835 } else {
836 if (NG_NODE_IS_VALID(node)) {
837 ng_rmnode_self(node);
838 }
839 }
840 return (0);
841 }
842
843 /************************************************************************
844 HELPER STUFF
845 ************************************************************************/
846
847 /*
848 * Handle an incoming frame. Extract the PPP protocol number
849 * and dispatch accordingly.
850 */
851 static int
852 ng_ppp_input(node_p node, int bypass, int linkNum, item_p item)
853 {
854 const priv_p priv = NG_NODE_PRIVATE(node);
855 hook_p outHook = NULL;
856 int proto, error;
857 struct mbuf *m;
858
859
860 NGI_GET_M(item, m);
861 /* Extract protocol number */
862 for (proto = 0; !PROT_VALID(proto) && m->m_pkthdr.len > 0; ) {
863 if (m->m_len < 1 && (m = m_pullup(m, 1)) == NULL) {
864 NG_FREE_ITEM(item);
865 return (ENOBUFS);
866 }
867 proto = (proto << 8) + *mtod(m, u_char *);
868 m_adj(m, 1);
869 }
870 if (!PROT_VALID(proto)) {
871 if (linkNum == NG_PPP_BUNDLE_LINKNUM)
872 priv->bundleStats.badProtos++;
873 else
874 priv->links[linkNum].stats.badProtos++;
875 NG_FREE_ITEM(item);
876 NG_FREE_M(m);
877 return (EINVAL);
878 }
879
880 /* Bypass frame? */
881 if (bypass)
882 goto bypass;
883
884 /* Check protocol */
885 switch (proto) {
886 case PROT_COMPD:
887 if (priv->conf.enableDecompression)
888 outHook = priv->hooks[HOOK_INDEX_DECOMPRESS];
889 break;
890 case PROT_CRYPTD:
891 if (priv->conf.enableDecryption)
892 outHook = priv->hooks[HOOK_INDEX_DECRYPT];
893 break;
894 case PROT_VJCOMP:
895 if (priv->conf.enableVJDecompression && priv->vjCompHooked)
896 outHook = priv->hooks[HOOK_INDEX_VJC_COMP];
897 break;
898 case PROT_VJUNCOMP:
899 if (priv->conf.enableVJDecompression && priv->vjCompHooked)
900 outHook = priv->hooks[HOOK_INDEX_VJC_UNCOMP];
901 break;
902 case PROT_MP:
903 if (priv->conf.enableMultilink
904 && linkNum != NG_PPP_BUNDLE_LINKNUM) {
905 NGI_M(item) = m;
906 return ng_ppp_mp_input(node, linkNum, item);
907 }
908 break;
909 case PROT_APPLETALK:
910 if (priv->conf.enableAtalk)
911 outHook = priv->hooks[HOOK_INDEX_ATALK];
912 break;
913 case PROT_IPX:
914 if (priv->conf.enableIPX)
915 outHook = priv->hooks[HOOK_INDEX_IPX];
916 break;
917 case PROT_IP:
918 if (priv->conf.enableIP)
919 outHook = priv->hooks[HOOK_INDEX_INET];
920 break;
921 case PROT_IPV6:
922 if (priv->conf.enableIPv6)
923 outHook = priv->hooks[HOOK_INDEX_IPV6];
924 break;
925 }
926
927 bypass:
928 /* For unknown/inactive protocols, forward out the bypass hook */
929 if (outHook == NULL) {
930 u_int16_t hdr[2];
931
932 hdr[0] = htons(linkNum);
933 hdr[1] = htons((u_int16_t)proto);
934 if ((m = ng_ppp_prepend(m, &hdr, 4)) == NULL) {
935 NG_FREE_ITEM(item);
936 return (ENOBUFS);
937 }
938 outHook = priv->hooks[HOOK_INDEX_BYPASS];
939 }
940
941 /* Forward frame */
942 NG_FWD_NEW_DATA(error, item, outHook, m);
943 return (error);
944 }
945
946 /*
947 * Deliver a frame out a link, either a real one or NG_PPP_BUNDLE_LINKNUM.
948 * If the link is not enabled then ENXIO is returned, unless "bypass" is != 0.
949 *
950 * If the frame is too big for the particular link, return EMSGSIZE.
951 */
952 static int
953 ng_ppp_output(node_p node, int bypass,
954 int proto, int linkNum, item_p item)
955 {
956 const priv_p priv = NG_NODE_PRIVATE(node);
957 struct ng_ppp_link *link;
958 int len, error;
959 struct mbuf *m;
960 u_int16_t mru;
961
962 /* Extract mbuf */
963 NGI_GET_M(item, m);
964
965 /* If not doing MP, map bundle virtual link to (the only) link */
966 if (linkNum == NG_PPP_BUNDLE_LINKNUM && !priv->conf.enableMultilink)
967 linkNum = priv->activeLinks[0];
968
969 /* Get link pointer (optimization) */
970 link = (linkNum != NG_PPP_BUNDLE_LINKNUM) ?
971 &priv->links[linkNum] : NULL;
972
973 /* Check link status (if real) */
974 if (linkNum != NG_PPP_BUNDLE_LINKNUM) {
975 if (!bypass && !link->conf.enableLink) {
976 NG_FREE_M(m);
977 NG_FREE_ITEM(item);
978 return (ENXIO);
979 }
980 if (link->hook == NULL) {
981 NG_FREE_M(m);
982 NG_FREE_ITEM(item);
983 return (ENETDOWN);
984 }
985 }
986
987 /* Check peer's MRU for this link */
988 mru = (link != NULL) ? link->conf.mru : priv->conf.mrru;
989 if (mru != 0 && m->m_pkthdr.len > mru) {
990 NG_FREE_M(m);
991 NG_FREE_ITEM(item);
992 return (EMSGSIZE);
993 }
994
995 /* Prepend protocol number, possibly compressed */
996 if ((m = ng_ppp_addproto(m, proto,
997 linkNum == NG_PPP_BUNDLE_LINKNUM
998 || link->conf.enableProtoComp)) == NULL) {
999 NG_FREE_ITEM(item);
1000 return (ENOBUFS);
1001 }
1002
1003 /* Special handling for the MP virtual link */
1004 if (linkNum == NG_PPP_BUNDLE_LINKNUM) {
1005 /* discard the queue item */
1006 NG_FREE_ITEM(item);
1007 return ng_ppp_mp_output(node, m);
1008 }
1009
1010 /* Prepend address and control field (unless compressed) */
1011 if (proto == PROT_LCP || !link->conf.enableACFComp) {
1012 if ((m = ng_ppp_prepend(m, &ng_ppp_acf, 2)) == NULL) {
1013 NG_FREE_ITEM(item);
1014 return (ENOBUFS);
1015 }
1016 }
1017
1018 /* Deliver frame */
1019 len = m->m_pkthdr.len;
1020 NG_FWD_NEW_DATA(error, item, link->hook, m);
1021
1022 /* Update stats and 'bytes in queue' counter */
1023 if (error == 0) {
1024 link->stats.xmitFrames++;
1025 link->stats.xmitOctets += len;
1026 link->bytesInQueue += len;
1027 getmicrouptime(&link->lastWrite);
1028 }
1029 return error;
1030 }
1031
1032 /*
1033 * Handle an incoming multi-link fragment
1034 *
1035 * The fragment reassembly algorithm is somewhat complex. This is mainly
1036 * because we are required not to reorder the reconstructed packets, yet
1037 * fragments are only guaranteed to arrive in order on a per-link basis.
1038 * In other words, when we have a complete packet ready, but the previous
1039 * packet is still incomplete, we have to decide between delivering the
1040 * complete packet and throwing away the incomplete one, or waiting to
1041 * see if the remainder of the incomplete one arrives, at which time we
1042 * can deliver both packets, in order.
1043 *
1044 * This problem is exacerbated by "sequence number slew", which is when
1045 * the sequence numbers coming in from different links are far apart from
1046 * each other. In particular, certain unnamed equipment (*cough* Ascend)
1047 * has been seen to generate sequence number slew of up to 10 on an ISDN
1048 * 2B-channel MP link. There is nothing invalid about sequence number slew
1049 * but it makes the reasssembly process have to work harder.
1050 *
1051 * However, the peer is required to transmit fragments in order on each
1052 * link. That means if we define MSEQ as the minimum over all links of
1053 * the highest sequence number received on that link, then we can always
1054 * give up any hope of receiving a fragment with sequence number < MSEQ in
1055 * the future (all of this using 'wraparound' sequence number space).
1056 * Therefore we can always immediately throw away incomplete packets
1057 * missing fragments with sequence numbers < MSEQ.
1058 *
1059 * Here is an overview of our algorithm:
1060 *
1061 * o Received fragments are inserted into a queue, for which we
1062 * maintain these invariants between calls to this function:
1063 *
1064 * - Fragments are ordered in the queue by sequence number
1065 * - If a complete packet is at the head of the queue, then
1066 * the first fragment in the packet has seq# > MSEQ + 1
1067 * (otherwise, we could deliver it immediately)
1068 * - If any fragments have seq# < MSEQ, then they are necessarily
1069 * part of a packet whose missing seq#'s are all > MSEQ (otherwise,
1070 * we can throw them away because they'll never be completed)
1071 * - The queue contains at most MP_MAX_QUEUE_LEN fragments
1072 *
1073 * o We have a periodic timer that checks the queue for the first
1074 * complete packet that has been sitting in the queue "too long".
1075 * When one is detected, all previous (incomplete) fragments are
1076 * discarded, their missing fragments are declared lost and MSEQ
1077 * is increased.
1078 *
1079 * o If we recieve a fragment with seq# < MSEQ, we throw it away
1080 * because we've already delcared it lost.
1081 *
1082 * This assumes linkNum != NG_PPP_BUNDLE_LINKNUM.
1083 */
1084 static int
1085 ng_ppp_mp_input(node_p node, int linkNum, item_p item)
1086 {
1087 const priv_p priv = NG_NODE_PRIVATE(node);
1088 struct ng_ppp_link *const link = &priv->links[linkNum];
1089 struct ng_ppp_frag frag0, *frag = &frag0;
1090 struct ng_ppp_frag *qent;
1091 int i, diff, inserted;
1092 struct mbuf *m;
1093
1094 NGI_GET_M(item, m);
1095 NG_FREE_ITEM(item);
1096 /* Stats */
1097 priv->bundleStats.recvFrames++;
1098 priv->bundleStats.recvOctets += m->m_pkthdr.len;
1099
1100 /* Extract fragment information from MP header */
1101 if (priv->conf.recvShortSeq) {
1102 u_int16_t shdr;
1103
1104 if (m->m_pkthdr.len < 2) {
1105 link->stats.runts++;
1106 NG_FREE_M(m);
1107 return (EINVAL);
1108 }
1109 if (m->m_len < 2 && (m = m_pullup(m, 2)) == NULL)
1110 return (ENOBUFS);
1111
1112 shdr = ntohs(*mtod(m, u_int16_t *));
1113 frag->seq = MP_SHORT_EXTEND(shdr);
1114 frag->first = (shdr & MP_SHORT_FIRST_FLAG) != 0;
1115 frag->last = (shdr & MP_SHORT_LAST_FLAG) != 0;
1116 diff = MP_SHORT_SEQ_DIFF(frag->seq, priv->mseq);
1117 m_adj(m, 2);
1118 } else {
1119 u_int32_t lhdr;
1120
1121 if (m->m_pkthdr.len < 4) {
1122 link->stats.runts++;
1123 NG_FREE_M(m);
1124 return (EINVAL);
1125 }
1126 if (m->m_len < 4 && (m = m_pullup(m, 4)) == NULL)
1127 return (ENOBUFS);
1128
1129 lhdr = ntohl(*mtod(m, u_int32_t *));
1130 frag->seq = MP_LONG_EXTEND(lhdr);
1131 frag->first = (lhdr & MP_LONG_FIRST_FLAG) != 0;
1132 frag->last = (lhdr & MP_LONG_LAST_FLAG) != 0;
1133 diff = MP_LONG_SEQ_DIFF(frag->seq, priv->mseq);
1134 m_adj(m, 4);
1135 }
1136 frag->data = m;
1137 getmicrouptime(&frag->timestamp);
1138
1139 /* If sequence number is < MSEQ, we've already declared this
1140 fragment as lost, so we have no choice now but to drop it */
1141 if (diff < 0) {
1142 link->stats.dropFragments++;
1143 NG_FREE_M(m);
1144 return (0);
1145 }
1146
1147 /* Update highest received sequence number on this link and MSEQ */
1148 priv->mseq = link->seq = frag->seq;
1149 for (i = 0; i < priv->numActiveLinks; i++) {
1150 struct ng_ppp_link *const alink =
1151 &priv->links[priv->activeLinks[i]];
1152
1153 if (MP_RECV_SEQ_DIFF(priv, alink->seq, priv->mseq) < 0)
1154 priv->mseq = alink->seq;
1155 }
1156
1157 /* Allocate a new frag struct for the queue */
1158 MALLOC(frag, struct ng_ppp_frag *, sizeof(*frag), M_NETGRAPH_PPP, M_NOWAIT);
1159 if (frag == NULL) {
1160 NG_FREE_M(m);
1161 ng_ppp_frag_process(node);
1162 return (ENOMEM);
1163 }
1164 *frag = frag0;
1165
1166 /* Add fragment to queue, which is sorted by sequence number */
1167 inserted = 0;
1168 TAILQ_FOREACH_REVERSE(qent, &priv->frags, ng_ppp_fraglist, f_qent) {
1169 diff = MP_RECV_SEQ_DIFF(priv, frag->seq, qent->seq);
1170 if (diff > 0) {
1171 TAILQ_INSERT_AFTER(&priv->frags, qent, frag, f_qent);
1172 inserted = 1;
1173 break;
1174 } else if (diff == 0) { /* should never happen! */
1175 link->stats.dupFragments++;
1176 NG_FREE_M(frag->data);
1177 FREE(frag, M_NETGRAPH_PPP);
1178 return (EINVAL);
1179 }
1180 }
1181 if (!inserted)
1182 TAILQ_INSERT_HEAD(&priv->frags, frag, f_qent);
1183 priv->qlen++;
1184
1185 /* Process the queue */
1186 return ng_ppp_frag_process(node);
1187 }
1188
1189 /*
1190 * Examine our list of fragments, and determine if there is a
1191 * complete and deliverable packet at the head of the list.
1192 * Return 1 if so, zero otherwise.
1193 */
1194 static int
1195 ng_ppp_check_packet(node_p node)
1196 {
1197 const priv_p priv = NG_NODE_PRIVATE(node);
1198 struct ng_ppp_frag *qent, *qnext;
1199
1200 /* Check for empty queue */
1201 if (TAILQ_EMPTY(&priv->frags))
1202 return (0);
1203
1204 /* Check first fragment is the start of a deliverable packet */
1205 qent = TAILQ_FIRST(&priv->frags);
1206 if (!qent->first || MP_RECV_SEQ_DIFF(priv, qent->seq, priv->mseq) > 1)
1207 return (0);
1208
1209 /* Check that all the fragments are there */
1210 while (!qent->last) {
1211 qnext = TAILQ_NEXT(qent, f_qent);
1212 if (qnext == NULL) /* end of queue */
1213 return (0);
1214 if (qnext->seq != MP_NEXT_RECV_SEQ(priv, qent->seq))
1215 return (0);
1216 qent = qnext;
1217 }
1218
1219 /* Got one */
1220 return (1);
1221 }
1222
1223 /*
1224 * Pull a completed packet off the head of the incoming fragment queue.
1225 * This assumes there is a completed packet there to pull off.
1226 */
1227 static void
1228 ng_ppp_get_packet(node_p node, struct mbuf **mp)
1229 {
1230 const priv_p priv = NG_NODE_PRIVATE(node);
1231 struct ng_ppp_frag *qent, *qnext;
1232 struct mbuf *m = NULL, *tail;
1233
1234 qent = TAILQ_FIRST(&priv->frags);
1235 KASSERT(!TAILQ_EMPTY(&priv->frags) && qent->first,
1236 ("%s: no packet", __func__));
1237 for (tail = NULL; qent != NULL; qent = qnext) {
1238 qnext = TAILQ_NEXT(qent, f_qent);
1239 KASSERT(!TAILQ_EMPTY(&priv->frags),
1240 ("%s: empty q", __func__));
1241 TAILQ_REMOVE(&priv->frags, qent, f_qent);
1242 if (tail == NULL)
1243 tail = m = qent->data;
1244 else {
1245 m->m_pkthdr.len += qent->data->m_pkthdr.len;
1246 tail->m_next = qent->data;
1247 }
1248 while (tail->m_next != NULL)
1249 tail = tail->m_next;
1250 if (qent->last)
1251 qnext = NULL;
1252 FREE(qent, M_NETGRAPH_PPP);
1253 priv->qlen--;
1254 }
1255 *mp = m;
1256 }
1257
1258 /*
1259 * Trim fragments from the queue whose packets can never be completed.
1260 * This assumes a complete packet is NOT at the beginning of the queue.
1261 * Returns 1 if fragments were removed, zero otherwise.
1262 */
1263 static int
1264 ng_ppp_frag_trim(node_p node)
1265 {
1266 const priv_p priv = NG_NODE_PRIVATE(node);
1267 struct ng_ppp_frag *qent, *qnext = NULL;
1268 int removed = 0;
1269
1270 /* Scan for "dead" fragments and remove them */
1271 while (1) {
1272 int dead = 0;
1273
1274 /* If queue is empty, we're done */
1275 if (TAILQ_EMPTY(&priv->frags))
1276 break;
1277
1278 /* Determine whether first fragment can ever be completed */
1279 TAILQ_FOREACH(qent, &priv->frags, f_qent) {
1280 if (MP_RECV_SEQ_DIFF(priv, qent->seq, priv->mseq) >= 0)
1281 break;
1282 qnext = TAILQ_NEXT(qent, f_qent);
1283 KASSERT(qnext != NULL,
1284 ("%s: last frag < MSEQ?", __func__));
1285 if (qnext->seq != MP_NEXT_RECV_SEQ(priv, qent->seq)
1286 || qent->last || qnext->first) {
1287 dead = 1;
1288 break;
1289 }
1290 }
1291 if (!dead)
1292 break;
1293
1294 /* Remove fragment and all others in the same packet */
1295 while ((qent = TAILQ_FIRST(&priv->frags)) != qnext) {
1296 KASSERT(!TAILQ_EMPTY(&priv->frags),
1297 ("%s: empty q", __func__));
1298 priv->bundleStats.dropFragments++;
1299 TAILQ_REMOVE(&priv->frags, qent, f_qent);
1300 NG_FREE_M(qent->data);
1301 FREE(qent, M_NETGRAPH_PPP);
1302 priv->qlen--;
1303 removed = 1;
1304 }
1305 }
1306 return (removed);
1307 }
1308
1309 /*
1310 * Run the queue, restoring the queue invariants
1311 */
1312 static int
1313 ng_ppp_frag_process(node_p node)
1314 {
1315 const priv_p priv = NG_NODE_PRIVATE(node);
1316 struct mbuf *m;
1317 item_p item;
1318
1319 /* Deliver any deliverable packets */
1320 while (ng_ppp_check_packet(node)) {
1321 ng_ppp_get_packet(node, &m);
1322 item = ng_package_data(m, NULL);
1323 ng_ppp_input(node, 0, NG_PPP_BUNDLE_LINKNUM, item);
1324 }
1325
1326 /* Delete dead fragments and try again */
1327 if (ng_ppp_frag_trim(node)) {
1328 while (ng_ppp_check_packet(node)) {
1329 ng_ppp_get_packet(node, &m);
1330 item = ng_package_data(m, NULL);
1331 ng_ppp_input(node, 0, NG_PPP_BUNDLE_LINKNUM, item);
1332 }
1333 }
1334
1335 /* Check for stale fragments while we're here */
1336 ng_ppp_frag_checkstale(node);
1337
1338 /* Check queue length */
1339 if (priv->qlen > MP_MAX_QUEUE_LEN) {
1340 struct ng_ppp_frag *qent;
1341 int i;
1342
1343 /* Get oldest fragment */
1344 KASSERT(!TAILQ_EMPTY(&priv->frags),
1345 ("%s: empty q", __func__));
1346 qent = TAILQ_FIRST(&priv->frags);
1347
1348 /* Bump MSEQ if necessary */
1349 if (MP_RECV_SEQ_DIFF(priv, priv->mseq, qent->seq) < 0) {
1350 priv->mseq = qent->seq;
1351 for (i = 0; i < priv->numActiveLinks; i++) {
1352 struct ng_ppp_link *const alink =
1353 &priv->links[priv->activeLinks[i]];
1354
1355 if (MP_RECV_SEQ_DIFF(priv,
1356 alink->seq, priv->mseq) < 0)
1357 alink->seq = priv->mseq;
1358 }
1359 }
1360
1361 /* Drop it */
1362 priv->bundleStats.dropFragments++;
1363 TAILQ_REMOVE(&priv->frags, qent, f_qent);
1364 NG_FREE_M(qent->data);
1365 FREE(qent, M_NETGRAPH_PPP);
1366 priv->qlen--;
1367
1368 /* Process queue again */
1369 return ng_ppp_frag_process(node);
1370 }
1371
1372 /* Done */
1373 return (0);
1374 }
1375
1376 /*
1377 * Check for 'stale' completed packets that need to be delivered
1378 *
1379 * If a link goes down or has a temporary failure, MSEQ can get
1380 * "stuck", because no new incoming fragments appear on that link.
1381 * This can cause completed packets to never get delivered if
1382 * their sequence numbers are all > MSEQ + 1.
1383 *
1384 * This routine checks how long all of the completed packets have
1385 * been sitting in the queue, and if too long, removes fragments
1386 * from the queue and increments MSEQ to allow them to be delivered.
1387 */
1388 static void
1389 ng_ppp_frag_checkstale(node_p node)
1390 {
1391 const priv_p priv = NG_NODE_PRIVATE(node);
1392 struct ng_ppp_frag *qent, *beg, *end;
1393 struct timeval now, age;
1394 struct mbuf *m;
1395 int i, seq;
1396 item_p item;
1397 int endseq;
1398
1399 now.tv_sec = 0; /* uninitialized state */
1400 while (1) {
1401
1402 /* If queue is empty, we're done */
1403 if (TAILQ_EMPTY(&priv->frags))
1404 break;
1405
1406 /* Find the first complete packet in the queue */
1407 beg = end = NULL;
1408 seq = TAILQ_FIRST(&priv->frags)->seq;
1409 TAILQ_FOREACH(qent, &priv->frags, f_qent) {
1410 if (qent->first)
1411 beg = qent;
1412 else if (qent->seq != seq)
1413 beg = NULL;
1414 if (beg != NULL && qent->last) {
1415 end = qent;
1416 break;
1417 }
1418 seq = MP_NEXT_RECV_SEQ(priv, seq);
1419 }
1420
1421 /* If none found, exit */
1422 if (end == NULL)
1423 break;
1424
1425 /* Get current time (we assume we've been up for >= 1 second) */
1426 if (now.tv_sec == 0)
1427 getmicrouptime(&now);
1428
1429 /* Check if packet has been queued too long */
1430 age = now;
1431 timevalsub(&age, &beg->timestamp);
1432 if (timevalcmp(&age, &ng_ppp_max_staleness, < ))
1433 break;
1434
1435 /* Throw away junk fragments in front of the completed packet */
1436 while ((qent = TAILQ_FIRST(&priv->frags)) != beg) {
1437 KASSERT(!TAILQ_EMPTY(&priv->frags),
1438 ("%s: empty q", __func__));
1439 priv->bundleStats.dropFragments++;
1440 TAILQ_REMOVE(&priv->frags, qent, f_qent);
1441 NG_FREE_M(qent->data);
1442 FREE(qent, M_NETGRAPH_PPP);
1443 priv->qlen--;
1444 }
1445
1446 /* Extract completed packet */
1447 endseq = end->seq;
1448 ng_ppp_get_packet(node, &m);
1449
1450 /* Bump MSEQ if necessary */
1451 if (MP_RECV_SEQ_DIFF(priv, priv->mseq, endseq) < 0) {
1452 priv->mseq = endseq;
1453 for (i = 0; i < priv->numActiveLinks; i++) {
1454 struct ng_ppp_link *const alink =
1455 &priv->links[priv->activeLinks[i]];
1456
1457 if (MP_RECV_SEQ_DIFF(priv,
1458 alink->seq, priv->mseq) < 0)
1459 alink->seq = priv->mseq;
1460 }
1461 }
1462
1463 /* Deliver packet */
1464 item = ng_package_data(m, NULL);
1465 ng_ppp_input(node, 0, NG_PPP_BUNDLE_LINKNUM, item);
1466 }
1467 }
1468
1469 /*
1470 * Periodically call ng_ppp_frag_checkstale()
1471 */
1472 static void
1473 ng_ppp_frag_timeout(node_p node, hook_p hook, void *arg1, int arg2)
1474 {
1475 /* XXX: is this needed? */
1476 if (NG_NODE_NOT_VALID(node))
1477 return;
1478
1479 /* Scan the fragment queue */
1480 ng_ppp_frag_checkstale(node);
1481
1482 /* Start timer again */
1483 ng_ppp_start_frag_timer(node);
1484 }
1485
1486 /*
1487 * Deliver a frame out on the bundle, i.e., figure out how to fragment
1488 * the frame across the individual PPP links and do so.
1489 */
1490 static int
1491 ng_ppp_mp_output(node_p node, struct mbuf *m)
1492 {
1493 const priv_p priv = NG_NODE_PRIVATE(node);
1494 const int hdr_len = priv->conf.xmitShortSeq ? 2 : 4;
1495 int distrib[NG_PPP_MAX_LINKS];
1496 int firstFragment;
1497 int activeLinkNum;
1498 item_p item;
1499
1500 /* At least one link must be active */
1501 if (priv->numActiveLinks == 0) {
1502 NG_FREE_M(m);
1503 return (ENETDOWN);
1504 }
1505
1506 /* Round-robin strategy */
1507 if (priv->conf.enableRoundRobin || m->m_pkthdr.len < MP_MIN_FRAG_LEN) {
1508 activeLinkNum = priv->lastLink++ % priv->numActiveLinks;
1509 bzero(&distrib, priv->numActiveLinks * sizeof(distrib[0]));
1510 distrib[activeLinkNum] = m->m_pkthdr.len;
1511 goto deliver;
1512 }
1513
1514 /* Strategy when all links are equivalent (optimize the common case) */
1515 if (priv->allLinksEqual) {
1516 const int fraction = m->m_pkthdr.len / priv->numActiveLinks;
1517 int i, remain;
1518
1519 for (i = 0; i < priv->numActiveLinks; i++)
1520 distrib[priv->lastLink++ % priv->numActiveLinks]
1521 = fraction;
1522 remain = m->m_pkthdr.len - (fraction * priv->numActiveLinks);
1523 while (remain > 0) {
1524 distrib[priv->lastLink++ % priv->numActiveLinks]++;
1525 remain--;
1526 }
1527 goto deliver;
1528 }
1529
1530 /* Strategy when all links are not equivalent */
1531 ng_ppp_mp_strategy(node, m->m_pkthdr.len, distrib);
1532
1533 deliver:
1534 /* Update stats */
1535 priv->bundleStats.xmitFrames++;
1536 priv->bundleStats.xmitOctets += m->m_pkthdr.len;
1537
1538 /* Send alloted portions of frame out on the link(s) */
1539 for (firstFragment = 1, activeLinkNum = priv->numActiveLinks - 1;
1540 activeLinkNum >= 0; activeLinkNum--) {
1541 const int linkNum = priv->activeLinks[activeLinkNum];
1542 struct ng_ppp_link *const link = &priv->links[linkNum];
1543
1544 /* Deliver fragment(s) out the next link */
1545 for ( ; distrib[activeLinkNum] > 0; firstFragment = 0) {
1546 int len, lastFragment, error;
1547 struct mbuf *m2;
1548
1549 /* Calculate fragment length; don't exceed link MTU */
1550 len = distrib[activeLinkNum];
1551 if (len > link->conf.mru - hdr_len)
1552 len = link->conf.mru - hdr_len;
1553 distrib[activeLinkNum] -= len;
1554 lastFragment = (len == m->m_pkthdr.len);
1555
1556 /* Split off next fragment as "m2" */
1557 m2 = m;
1558 if (!lastFragment) {
1559 struct mbuf *n = m_split(m, len, M_DONTWAIT);
1560
1561 if (n == NULL) {
1562 NG_FREE_M(m);
1563 return (ENOMEM);
1564 }
1565 m = n;
1566 }
1567
1568 /* Prepend MP header */
1569 if (priv->conf.xmitShortSeq) {
1570 u_int16_t shdr;
1571
1572 shdr = priv->xseq;
1573 priv->xseq =
1574 (priv->xseq + 1) & MP_SHORT_SEQ_MASK;
1575 if (firstFragment)
1576 shdr |= MP_SHORT_FIRST_FLAG;
1577 if (lastFragment)
1578 shdr |= MP_SHORT_LAST_FLAG;
1579 shdr = htons(shdr);
1580 m2 = ng_ppp_prepend(m2, &shdr, 2);
1581 } else {
1582 u_int32_t lhdr;
1583
1584 lhdr = priv->xseq;
1585 priv->xseq =
1586 (priv->xseq + 1) & MP_LONG_SEQ_MASK;
1587 if (firstFragment)
1588 lhdr |= MP_LONG_FIRST_FLAG;
1589 if (lastFragment)
1590 lhdr |= MP_LONG_LAST_FLAG;
1591 lhdr = htonl(lhdr);
1592 m2 = ng_ppp_prepend(m2, &lhdr, 4);
1593 }
1594 if (m2 == NULL) {
1595 if (!lastFragment)
1596 m_freem(m);
1597 return (ENOBUFS);
1598 }
1599
1600 /* Send fragment */
1601 item = ng_package_data(m2, NULL);
1602 error = ng_ppp_output(node, 0, PROT_MP, linkNum, item);
1603 if (error != 0) {
1604 if (!lastFragment)
1605 NG_FREE_M(m);
1606 return (error);
1607 }
1608 }
1609 }
1610
1611 /* Done */
1612 return (0);
1613 }
1614
1615 /*
1616 * Computing the optimal fragmentation
1617 * -----------------------------------
1618 *
1619 * This routine tries to compute the optimal fragmentation pattern based
1620 * on each link's latency, bandwidth, and calculated additional latency.
1621 * The latter quantity is the additional latency caused by previously
1622 * written data that has not been transmitted yet.
1623 *
1624 * This algorithm is only useful when not all of the links have the
1625 * same latency and bandwidth values.
1626 *
1627 * The essential idea is to make the last bit of each fragment of the
1628 * frame arrive at the opposite end at the exact same time. This greedy
1629 * algorithm is optimal, in that no other scheduling could result in any
1630 * packet arriving any sooner unless packets are delivered out of order.
1631 *
1632 * Suppose link i has bandwidth b_i (in tens of bytes per milisecond) and
1633 * latency l_i (in miliseconds). Consider the function function f_i(t)
1634 * which is equal to the number of bytes that will have arrived at
1635 * the peer after t miliseconds if we start writing continuously at
1636 * time t = 0. Then f_i(t) = b_i * (t - l_i) = ((b_i * t) - (l_i * b_i).
1637 * That is, f_i(t) is a line with slope b_i and y-intersect -(l_i * b_i).
1638 * Note that the y-intersect is always <= zero because latency can't be
1639 * negative. Note also that really the function is f_i(t) except when
1640 * f_i(t) is negative, in which case the function is zero. To take
1641 * care of this, let Q_i(t) = { if (f_i(t) > 0) return 1; else return 0; }.
1642 * So the actual number of bytes that will have arrived at the peer after
1643 * t miliseconds is f_i(t) * Q_i(t).
1644 *
1645 * At any given time, each link has some additional latency a_i >= 0
1646 * due to previously written fragment(s) which are still in the queue.
1647 * This value is easily computed from the time since last transmission,
1648 * the previous latency value, the number of bytes written, and the
1649 * link's bandwidth.
1650 *
1651 * Assume that l_i includes any a_i already, and that the links are
1652 * sorted by latency, so that l_i <= l_{i+1}.
1653 *
1654 * Let N be the total number of bytes in the current frame we are sending.
1655 *
1656 * Suppose we were to start writing bytes at time t = 0 on all links
1657 * simultaneously, which is the most we can possibly do. Then let
1658 * F(t) be equal to the total number of bytes received by the peer
1659 * after t miliseconds. Then F(t) = Sum_i (f_i(t) * Q_i(t)).
1660 *
1661 * Our goal is simply this: fragment the frame across the links such
1662 * that the peer is able to reconstruct the completed frame as soon as
1663 * possible, i.e., at the least possible value of t. Call this value t_0.
1664 *
1665 * Then it follows that F(t_0) = N. Our strategy is first to find the value
1666 * of t_0, and then deduce how many bytes to write to each link.
1667 *
1668 * Rewriting F(t_0):
1669 *
1670 * t_0 = ( N + Sum_i ( l_i * b_i * Q_i(t_0) ) ) / Sum_i ( b_i * Q_i(t_0) )
1671 *
1672 * Now, we note that Q_i(t) is constant for l_i <= t <= l_{i+1}. t_0 will
1673 * lie in one of these ranges. To find it, we just need to find the i such
1674 * that F(l_i) <= N <= F(l_{i+1}). Then we compute all the constant values
1675 * for Q_i() in this range, plug in the remaining values, solving for t_0.
1676 *
1677 * Once t_0 is known, then the number of bytes to send on link i is
1678 * just f_i(t_0) * Q_i(t_0).
1679 *
1680 * In other words, we start allocating bytes to the links one at a time.
1681 * We keep adding links until the frame is completely sent. Some links
1682 * may not get any bytes because their latency is too high.
1683 *
1684 * Is all this work really worth the trouble? Depends on the situation.
1685 * The bigger the ratio of computer speed to link speed, and the more
1686 * important total bundle latency is (e.g., for interactive response time),
1687 * the more it's worth it. There is however the cost of calling this
1688 * function for every frame. The running time is O(n^2) where n is the
1689 * number of links that receive a non-zero number of bytes.
1690 *
1691 * Since latency is measured in miliseconds, the "resolution" of this
1692 * algorithm is one milisecond.
1693 *
1694 * To avoid this algorithm altogether, configure all links to have the
1695 * same latency and bandwidth.
1696 */
1697 static void
1698 ng_ppp_mp_strategy(node_p node, int len, int *distrib)
1699 {
1700 const priv_p priv = NG_NODE_PRIVATE(node);
1701 int latency[NG_PPP_MAX_LINKS];
1702 int sortByLatency[NG_PPP_MAX_LINKS];
1703 int activeLinkNum;
1704 int t0, total, topSum, botSum;
1705 struct timeval now;
1706 int i, numFragments;
1707
1708 /* If only one link, this gets real easy */
1709 if (priv->numActiveLinks == 1) {
1710 distrib[0] = len;
1711 return;
1712 }
1713
1714 /* Get current time */
1715 getmicrouptime(&now);
1716
1717 /* Compute latencies for each link at this point in time */
1718 for (activeLinkNum = 0;
1719 activeLinkNum < priv->numActiveLinks; activeLinkNum++) {
1720 struct ng_ppp_link *alink;
1721 struct timeval diff;
1722 int xmitBytes;
1723
1724 /* Start with base latency value */
1725 alink = &priv->links[priv->activeLinks[activeLinkNum]];
1726 latency[activeLinkNum] = alink->latency;
1727 sortByLatency[activeLinkNum] = activeLinkNum; /* see below */
1728
1729 /* Any additional latency? */
1730 if (alink->bytesInQueue == 0)
1731 continue;
1732
1733 /* Compute time delta since last write */
1734 diff = now;
1735 timevalsub(&diff, &alink->lastWrite);
1736 if (now.tv_sec < 0 || diff.tv_sec >= 10) { /* sanity */
1737 alink->bytesInQueue = 0;
1738 continue;
1739 }
1740
1741 /* How many bytes could have transmitted since last write? */
1742 xmitBytes = (alink->conf.bandwidth * diff.tv_sec)
1743 + (alink->conf.bandwidth * (diff.tv_usec / 1000)) / 100;
1744 alink->bytesInQueue -= xmitBytes;
1745 if (alink->bytesInQueue < 0)
1746 alink->bytesInQueue = 0;
1747 else
1748 latency[activeLinkNum] +=
1749 (100 * alink->bytesInQueue) / alink->conf.bandwidth;
1750 }
1751
1752 /* Sort active links by latency */
1753 qsort_r(sortByLatency,
1754 priv->numActiveLinks, sizeof(*sortByLatency), latency, ng_ppp_intcmp);
1755
1756 /* Find the interval we need (add links in sortByLatency[] order) */
1757 for (numFragments = 1;
1758 numFragments < priv->numActiveLinks; numFragments++) {
1759 for (total = i = 0; i < numFragments; i++) {
1760 int flowTime;
1761
1762 flowTime = latency[sortByLatency[numFragments]]
1763 - latency[sortByLatency[i]];
1764 total += ((flowTime * priv->links[
1765 priv->activeLinks[sortByLatency[i]]].conf.bandwidth)
1766 + 99) / 100;
1767 }
1768 if (total >= len)
1769 break;
1770 }
1771
1772 /* Solve for t_0 in that interval */
1773 for (topSum = botSum = i = 0; i < numFragments; i++) {
1774 int bw = priv->links[
1775 priv->activeLinks[sortByLatency[i]]].conf.bandwidth;
1776
1777 topSum += latency[sortByLatency[i]] * bw; /* / 100 */
1778 botSum += bw; /* / 100 */
1779 }
1780 t0 = ((len * 100) + topSum + botSum / 2) / botSum;
1781
1782 /* Compute f_i(t_0) all i */
1783 bzero(distrib, priv->numActiveLinks * sizeof(*distrib));
1784 for (total = i = 0; i < numFragments; i++) {
1785 int bw = priv->links[
1786 priv->activeLinks[sortByLatency[i]]].conf.bandwidth;
1787
1788 distrib[sortByLatency[i]] =
1789 (bw * (t0 - latency[sortByLatency[i]]) + 50) / 100;
1790 total += distrib[sortByLatency[i]];
1791 }
1792
1793 /* Deal with any rounding error */
1794 if (total < len) {
1795 struct ng_ppp_link *fastLink =
1796 &priv->links[priv->activeLinks[sortByLatency[0]]];
1797 int fast = 0;
1798
1799 /* Find the fastest link */
1800 for (i = 1; i < numFragments; i++) {
1801 struct ng_ppp_link *const link =
1802 &priv->links[priv->activeLinks[sortByLatency[i]]];
1803
1804 if (link->conf.bandwidth > fastLink->conf.bandwidth) {
1805 fast = i;
1806 fastLink = link;
1807 }
1808 }
1809 distrib[sortByLatency[fast]] += len - total;
1810 } else while (total > len) {
1811 struct ng_ppp_link *slowLink =
1812 &priv->links[priv->activeLinks[sortByLatency[0]]];
1813 int delta, slow = 0;
1814
1815 /* Find the slowest link that still has bytes to remove */
1816 for (i = 1; i < numFragments; i++) {
1817 struct ng_ppp_link *const link =
1818 &priv->links[priv->activeLinks[sortByLatency[i]]];
1819
1820 if (distrib[sortByLatency[slow]] == 0
1821 || (distrib[sortByLatency[i]] > 0
1822 && link->conf.bandwidth <
1823 slowLink->conf.bandwidth)) {
1824 slow = i;
1825 slowLink = link;
1826 }
1827 }
1828 delta = total - len;
1829 if (delta > distrib[sortByLatency[slow]])
1830 delta = distrib[sortByLatency[slow]];
1831 distrib[sortByLatency[slow]] -= delta;
1832 total -= delta;
1833 }
1834 }
1835
1836 /*
1837 * Compare two integers
1838 */
1839 static int
1840 ng_ppp_intcmp(void *latency, const void *v1, const void *v2)
1841 {
1842 const int index1 = *((const int *) v1);
1843 const int index2 = *((const int *) v2);
1844
1845 return ((int *)latency)[index1] - ((int *)latency)[index2];
1846 }
1847
1848 /*
1849 * Prepend a possibly compressed PPP protocol number in front of a frame
1850 */
1851 static struct mbuf *
1852 ng_ppp_addproto(struct mbuf *m, int proto, int compOK)
1853 {
1854 if (compOK && PROT_COMPRESSABLE(proto)) {
1855 u_char pbyte = (u_char)proto;
1856
1857 return ng_ppp_prepend(m, &pbyte, 1);
1858 } else {
1859 u_int16_t pword = htons((u_int16_t)proto);
1860
1861 return ng_ppp_prepend(m, &pword, 2);
1862 }
1863 }
1864
1865 /*
1866 * Prepend some bytes to an mbuf
1867 */
1868 static struct mbuf *
1869 ng_ppp_prepend(struct mbuf *m, const void *buf, int len)
1870 {
1871 M_PREPEND(m, len, M_DONTWAIT);
1872 if (m == NULL || (m->m_len < len && (m = m_pullup(m, len)) == NULL))
1873 return (NULL);
1874 bcopy(buf, mtod(m, u_char *), len);
1875 return (m);
1876 }
1877
1878 /*
1879 * Update private information that is derived from other private information
1880 */
1881 static void
1882 ng_ppp_update(node_p node, int newConf)
1883 {
1884 const priv_p priv = NG_NODE_PRIVATE(node);
1885 int i;
1886
1887 /* Update active status for VJ Compression */
1888 priv->vjCompHooked = priv->hooks[HOOK_INDEX_VJC_IP] != NULL
1889 && priv->hooks[HOOK_INDEX_VJC_COMP] != NULL
1890 && priv->hooks[HOOK_INDEX_VJC_UNCOMP] != NULL
1891 && priv->hooks[HOOK_INDEX_VJC_VJIP] != NULL;
1892
1893 /* Increase latency for each link an amount equal to one MP header */
1894 if (newConf) {
1895 for (i = 0; i < NG_PPP_MAX_LINKS; i++) {
1896 int hdrBytes;
1897
1898 hdrBytes = (priv->links[i].conf.enableACFComp ? 0 : 2)
1899 + (priv->links[i].conf.enableProtoComp ? 1 : 2)
1900 + (priv->conf.xmitShortSeq ? 2 : 4);
1901 priv->links[i].latency =
1902 priv->links[i].conf.latency +
1903 ((hdrBytes * priv->links[i].conf.bandwidth) + 50)
1904 / 100;
1905 }
1906 }
1907
1908 /* Update list of active links */
1909 bzero(&priv->activeLinks, sizeof(priv->activeLinks));
1910 priv->numActiveLinks = 0;
1911 priv->allLinksEqual = 1;
1912 for (i = 0; i < NG_PPP_MAX_LINKS; i++) {
1913 struct ng_ppp_link *const link = &priv->links[i];
1914
1915 /* Is link active? */
1916 if (link->conf.enableLink && link->hook != NULL) {
1917 struct ng_ppp_link *link0;
1918
1919 /* Add link to list of active links */
1920 priv->activeLinks[priv->numActiveLinks++] = i;
1921 link0 = &priv->links[priv->activeLinks[0]];
1922
1923 /* Determine if all links are still equal */
1924 if (link->latency != link0->latency
1925 || link->conf.bandwidth != link0->conf.bandwidth)
1926 priv->allLinksEqual = 0;
1927
1928 /* Initialize rec'd sequence number */
1929 if (link->seq == MP_NOSEQ) {
1930 link->seq = (link == link0) ?
1931 MP_INITIAL_SEQ : link0->seq;
1932 }
1933 } else
1934 link->seq = MP_NOSEQ;
1935 }
1936
1937 /* Update MP state as multi-link is active or not */
1938 if (priv->conf.enableMultilink && priv->numActiveLinks > 0)
1939 ng_ppp_start_frag_timer(node);
1940 else {
1941 ng_ppp_stop_frag_timer(node);
1942 ng_ppp_frag_reset(node);
1943 priv->xseq = MP_INITIAL_SEQ;
1944 priv->mseq = MP_INITIAL_SEQ;
1945 for (i = 0; i < NG_PPP_MAX_LINKS; i++) {
1946 struct ng_ppp_link *const link = &priv->links[i];
1947
1948 bzero(&link->lastWrite, sizeof(link->lastWrite));
1949 link->bytesInQueue = 0;
1950 link->seq = MP_NOSEQ;
1951 }
1952 }
1953 }
1954
1955 /*
1956 * Determine if a new configuration would represent a valid change
1957 * from the current configuration and link activity status.
1958 */
1959 static int
1960 ng_ppp_config_valid(node_p node, const struct ng_ppp_node_conf *newConf)
1961 {
1962 const priv_p priv = NG_NODE_PRIVATE(node);
1963 int i, newNumLinksActive;
1964
1965 /* Check per-link config and count how many links would be active */
1966 for (newNumLinksActive = i = 0; i < NG_PPP_MAX_LINKS; i++) {
1967 if (newConf->links[i].enableLink && priv->links[i].hook != NULL)
1968 newNumLinksActive++;
1969 if (!newConf->links[i].enableLink)
1970 continue;
1971 if (newConf->links[i].mru < MP_MIN_LINK_MRU)
1972 return (0);
1973 if (newConf->links[i].bandwidth == 0)
1974 return (0);
1975 if (newConf->links[i].bandwidth > NG_PPP_MAX_BANDWIDTH)
1976 return (0);
1977 if (newConf->links[i].latency > NG_PPP_MAX_LATENCY)
1978 return (0);
1979 }
1980
1981 /* Check bundle parameters */
1982 if (newConf->bund.enableMultilink && newConf->bund.mrru < MP_MIN_MRRU)
1983 return (0);
1984
1985 /* Disallow changes to multi-link configuration while MP is active */
1986 if (priv->numActiveLinks > 0 && newNumLinksActive > 0) {
1987 if (!priv->conf.enableMultilink
1988 != !newConf->bund.enableMultilink
1989 || !priv->conf.xmitShortSeq != !newConf->bund.xmitShortSeq
1990 || !priv->conf.recvShortSeq != !newConf->bund.recvShortSeq)
1991 return (0);
1992 }
1993
1994 /* At most one link can be active unless multi-link is enabled */
1995 if (!newConf->bund.enableMultilink && newNumLinksActive > 1)
1996 return (0);
1997
1998 /* Configuration change would be valid */
1999 return (1);
2000 }
2001
2002 /*
2003 * Free all entries in the fragment queue
2004 */
2005 static void
2006 ng_ppp_frag_reset(node_p node)
2007 {
2008 const priv_p priv = NG_NODE_PRIVATE(node);
2009 struct ng_ppp_frag *qent, *qnext;
2010
2011 for (qent = TAILQ_FIRST(&priv->frags); qent; qent = qnext) {
2012 qnext = TAILQ_NEXT(qent, f_qent);
2013 NG_FREE_M(qent->data);
2014 FREE(qent, M_NETGRAPH_PPP);
2015 }
2016 TAILQ_INIT(&priv->frags);
2017 priv->qlen = 0;
2018 }
2019
2020 /*
2021 * Start fragment queue timer
2022 */
2023 static void
2024 ng_ppp_start_frag_timer(node_p node)
2025 {
2026 const priv_p priv = NG_NODE_PRIVATE(node);
2027
2028 if (!(callout_pending(&priv->fragTimer)))
2029 ng_callout(&priv->fragTimer, node, NULL, MP_FRAGTIMER_INTERVAL,
2030 ng_ppp_frag_timeout, NULL, 0);
2031 }
2032
2033 /*
2034 * Stop fragment queue timer
2035 */
2036 static void
2037 ng_ppp_stop_frag_timer(node_p node)
2038 {
2039 const priv_p priv = NG_NODE_PRIVATE(node);
2040
2041 if (callout_pending(&priv->fragTimer))
2042 ng_uncallout(&priv->fragTimer, node);
2043 }
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