xref: /netbsd-src/usr.sbin/altq/libaltq/qop_hfsc.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: qop_hfsc.c,v 1.8 2006/10/12 19:59:13 peter Exp $	*/
2 /*	$KAME: qop_hfsc.c,v 1.12 2005/01/05 04:53:47 itojun Exp $	*/
3 /*
4  * Copyright (C) 1999-2000
5  *	Sony Computer Science Laboratories, Inc.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY SONY CSL AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL SONY CSL OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/param.h>
30 #include <sys/socket.h>
31 #include <sys/sockio.h>
32 #include <sys/ioctl.h>
33 #include <sys/fcntl.h>
34 #include <net/if.h>
35 #include <netinet/in.h>
36 #include <arpa/inet.h>
37 
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <unistd.h>
41 #include <stddef.h>
42 #include <string.h>
43 #include <ctype.h>
44 #include <errno.h>
45 #include <syslog.h>
46 #include <netdb.h>
47 #include <math.h>
48 
49 #include <altq/altq.h>
50 #include <altq/altq_hfsc.h>
51 #include "altq_qop.h"
52 #include "qop_hfsc.h"
53 
54 static int read_sc(int *, char ***, int *, u_int *, u_int *, u_int *);
55 static int qop_hfsc_enable_hook(struct ifinfo *);
56 static int qop_hfsc_delete_class_hook(struct classinfo *);
57 static int validate_sc(struct service_curve *);
58 
59 static void gsc_add_sc(struct gen_sc *, struct service_curve *);
60 static void gsc_sub_sc(struct gen_sc *, struct service_curve *);
61 static int is_gsc_under_sc(struct gen_sc *, struct service_curve *);
62 static void gsc_destroy(struct gen_sc *);
63 static struct segment *gsc_getentry(struct gen_sc *, double);
64 static int gsc_add_seg(struct gen_sc *, double, double, double, double);
65 static int gsc_sub_seg(struct gen_sc *, double, double, double, double);
66 static void gsc_compress(struct gen_sc *);
67 static double sc_x2y(struct service_curve *, double);
68 
69 static int hfsc_attach(struct ifinfo *);
70 static int hfsc_detach(struct ifinfo *);
71 static int hfsc_clear(struct ifinfo *);
72 static int hfsc_enable(struct ifinfo *);
73 static int hfsc_disable(struct ifinfo *);
74 static int hfsc_add_class(struct classinfo *);
75 static int hfsc_modify_class(struct classinfo *, void *);
76 static int hfsc_delete_class(struct classinfo *);
77 static int hfsc_add_filter(struct fltrinfo *);
78 static int hfsc_delete_filter(struct fltrinfo *);
79 
80 #define HFSC_DEVICE	"/dev/altq/hfsc"
81 
82 static int hfsc_fd = -1;
83 static int hfsc_refcount = 0;
84 
85 static struct qdisc_ops hfsc_qdisc = {
86 	ALTQT_HFSC,
87 	"hfsc",
88 	hfsc_attach,
89 	hfsc_detach,
90 	hfsc_clear,
91 	hfsc_enable,
92 	hfsc_disable,
93 	hfsc_add_class,
94 	hfsc_modify_class,
95 	hfsc_delete_class,
96 	hfsc_add_filter,
97 	hfsc_delete_filter,
98 };
99 
100 #define EQUAL(s1, s2)	(strcmp((s1), (s2)) == 0)
101 
102 /*
103  * parser interface
104  */
105 int
106 hfsc_interface_parser(const char *ifname, int argc, char **argv)
107 {
108 	u_int  	bandwidth = 100000000;	/* 100Mbps */
109 	u_int	tbrsize = 0;
110 	int	flags = 0;
111 
112 	/*
113 	 * process options
114 	 */
115 	while (argc > 0) {
116 		if (EQUAL(*argv, "bandwidth")) {
117 			argc--; argv++;
118 			if (argc > 0)
119 				bandwidth = atobps(*argv);
120 		} else if (EQUAL(*argv, "tbrsize")) {
121 			argc--; argv++;
122 			if (argc > 0)
123 				tbrsize = atobytes(*argv);
124 		} else if (EQUAL(*argv, "hfsc")) {
125 			/* just skip */
126 		} else {
127 			LOG(LOG_ERR, 0, "Unknown keyword '%s'", *argv);
128 			return (0);
129 		}
130 		argc--; argv++;
131 	}
132 
133 	if (qcmd_tbr_register(ifname, bandwidth, tbrsize) != 0)
134 		return (0);
135 
136 	if (qcmd_hfsc_add_if(ifname, bandwidth, flags) != 0)
137 		return (0);
138 	return (1);
139 }
140 
141 int
142 hfsc_class_parser(const char *ifname, const char *class_name,
143 		  const char *parent_name, int argc, char **argv)
144 {
145 	u_int	m1, d, m2, rm1, rd, rm2, fm1, fd, fm2, um1, ud, um2;
146 	int	qlimit = 50;
147 	int	flags = 0, admission = 0;
148 	int	type = 0, error;
149 
150 	rm1 = rd = rm2 = fm1 = fd = fm2 = um1 = ud = um2 = 0;
151 	while (argc > 0) {
152 		if (*argv[0] == '[') {
153 			if (read_sc(&argc, &argv, &type, &m1, &d, &m2) != 0) {
154 				LOG(LOG_ERR, 0,
155 				    "Bad service curve in %s, line %d",
156 				    altqconfigfile, line_no);
157 				return (0);
158 			}
159 			if (type & HFSC_REALTIMESC) {
160 				rm1 = m1; rd = d; rm2 = m2;
161 			}
162 			if (type & HFSC_LINKSHARINGSC) {
163 				fm1 = m1; fd = d; fm2 = m2;
164 			}
165 			if (type & HFSC_UPPERLIMITSC) {
166 				um1 = m1; ud = d; um2 = m2;
167 			}
168 		} else if (EQUAL(*argv, "ulimit")) {
169 			argc--; argv++;
170 			if (argc > 0) {
171 				um2 = atobps(*argv);
172 				type |= HFSC_UPPERLIMITSC;
173 			}
174 		} else if (EQUAL(*argv, "pshare")) {
175 			argc--; argv++;
176 			if (argc > 0) {
177 				struct ifinfo	*ifinfo;
178 				u_int pshare;
179 
180 				pshare = (u_int)strtoul(*argv, NULL, 0);
181 				if ((ifinfo = ifname2ifinfo(ifname)) != NULL) {
182 					fm2 = ifinfo->bandwidth / 100 * pshare;
183 					type |= HFSC_LINKSHARINGSC;
184 				}
185 			}
186 		} else if (EQUAL(*argv, "grate")) {
187 			argc--; argv++;
188 			if (argc > 0) {
189 				rm2 = atobps(*argv);
190 				type |= HFSC_REALTIMESC;
191 			}
192 		} else if (EQUAL(*argv, "bandwidth")) {
193 			argc--; argv++;
194 			if (argc > 0) {
195 				rm2 = fm2 = atobps(*argv);
196 				type |= (HFSC_REALTIMESC | HFSC_LINKSHARINGSC);
197 			}
198 		} else if (EQUAL(*argv, "qlimit")) {
199 			argc--; argv++;
200 			if (argc > 0)
201 				qlimit = strtoul(*argv, NULL, 0);
202 		} else if (EQUAL(*argv, "default")) {
203 			flags |= HFCF_DEFAULTCLASS;
204 		} else if (EQUAL(*argv, "admission")) {
205 			argc--; argv++;
206 			if (argc > 0) {
207 				if (EQUAL(*argv, "guaranteed")
208 				    || EQUAL(*argv, "cntlload"))
209 					admission = 1;
210 				else if (EQUAL(*argv, "none")) {
211 					/* nothing */
212 				} else {
213 					LOG(LOG_ERR, 0,
214 					    "unknown admission type - %s, line %d",
215 					    *argv, line_no);
216 					return (0);
217 				}
218 			}
219 		} else if (EQUAL(*argv, "red")) {
220 			flags |= HFCF_RED;
221 		} else if (EQUAL(*argv, "ecn")) {
222 			flags |= HFCF_ECN;
223 		} else if (EQUAL(*argv, "rio")) {
224 			flags |= HFCF_RIO;
225 		} else if (EQUAL(*argv, "cleardscp")) {
226 			flags |= HFCF_CLEARDSCP;
227 		} else {
228 			LOG(LOG_ERR, 0,
229 			    "Unknown keyword '%s' in %s, line %d",
230 			    *argv, altqconfigfile, line_no);
231 			return (0);
232 		}
233 
234 		argc--; argv++;
235 	}
236 
237 	if (type == 0) {
238 		LOG(LOG_ERR, 0,
239 		    "hfsc: service curve not specified in %s, line %d",
240 		    altqconfigfile, line_no);
241 		return (0);
242 	}
243 
244 	if ((flags & HFCF_ECN) && (flags & (HFCF_RED|HFCF_RIO)) == 0)
245 		flags |= HFCF_RED;
246 
247 	/*
248 	 * if the link-sharing service curve is diffrent from
249 	 * the real-time service curve, we first create a class with the
250 	 * smaller service curve and then modify the other service curve.
251 	 */
252 	if (rm2 <= fm2) {
253 		m1 = rm1; d = rd; m2 = rm2;
254 	} else {
255 		m1 = fm1; d = fd; m2 = fm2;
256 	}
257 	error = qcmd_hfsc_add_class(ifname, class_name, parent_name,
258 				    m1, d, m2, qlimit, flags);
259 
260 	if (error == 0 && (rm1 != fm1 || rd != fd || rm2 != fm2)) {
261 		if (rm2 <= fm2) {
262 			m1 = fm1; d = fd; m2 = fm2; type = HFSC_LINKSHARINGSC;
263 		} else {
264 			m1 = rm1; d = rd; m2 = rm2; type = HFSC_REALTIMESC;
265 		}
266 		error = qcmd_hfsc_modify_class(ifname, class_name,
267 					       m1, d, m2, type);
268 	}
269 
270 	if (error == 0 && (um1 != 0 || um2 != 0)) {
271 		error = qcmd_hfsc_modify_class(ifname, class_name,
272 		    um1, ud, um2, HFSC_UPPERLIMITSC);
273 	}
274 
275 	if (error == 0 && admission) {
276 		/* this is a special class for rsvp */
277 		struct ifinfo *ifinfo = ifname2ifinfo(ifname);
278 		struct classinfo *clinfo = clname2clinfo(ifinfo, class_name);
279 
280 		if (ifinfo->resv_class != NULL) {
281 			LOG(LOG_ERR, 0,
282 			    "more than one admission class specified: %s",
283 			    class_name);
284 			return (0);
285 		}
286 		ifinfo->resv_class = clinfo;
287 	}
288 
289 	if (error) {
290 		LOG(LOG_ERR, errno, "hfsc_class_parser: %s",
291 		    qoperror(error));
292 		return (0);
293 	}
294 	return (1);
295 }
296 
297 /*
298  * read service curve parameters
299  * '[' <type> <m1> <d> <m2> ']'
300  *  type := "sc", "rt", "ls", or "ul"
301  */
302 static int
303 read_sc(int *argcp, char ***argvp, int *type, u_int *m1, u_int *d, u_int *m2)
304 {
305 	int argc = *argcp;
306 	char **argv = *argvp;
307 	char *cp;
308 
309 	cp = *argv;
310 	if (*cp++ != '[')
311 		return (-1);
312 	if (*cp == '\0') {
313 		cp = *++argv; --argc;
314 	}
315 	if (*cp == 's' || *cp == 'S')
316 		*type = HFSC_DEFAULTSC;
317 	else if (*cp == 'r' || *cp == 'R')
318 		*type = HFSC_REALTIMESC;
319 	else if (*cp == 'l' || *cp == 'L')
320 		*type = HFSC_LINKSHARINGSC;
321 	else if (*cp == 'u' || *cp == 'U')
322 		*type = HFSC_UPPERLIMITSC;
323 	else
324 		return (-1);
325 	cp = *++argv; --argc;
326 	*m1 = atobps(cp);
327 	cp = *++argv; --argc;
328 	*d = (u_int)strtoul(cp, NULL, 0);
329 	cp = *++argv; --argc;
330 	*m2 = atobps(cp);
331 	if (strchr(cp, ']') == NULL) {
332 		cp = *++argv; --argc;
333 		if (*cp != ']')
334 			return (-1);
335 	}
336 	*argcp = argc;
337 	*argvp = argv;
338 	return (0);
339 }
340 
341 /*
342  * qcmd api
343  */
344 int
345 qcmd_hfsc_add_if(const char *ifname, u_int bandwidth, int flags)
346 {
347 	int error;
348 
349 	error = qop_hfsc_add_if(NULL, ifname, bandwidth, flags);
350 	if (error != 0)
351 		LOG(LOG_ERR, errno, "%s: can't add hfsc on interface '%s'",
352 		    qoperror(error), ifname);
353 	return (error);
354 }
355 
356 int
357 qcmd_hfsc_add_class(const char *ifname, const char *class_name,
358 		    const char *parent_name, u_int m1, u_int d, u_int m2,
359 		    int qlimit, int flags)
360 {
361 	struct ifinfo *ifinfo;
362 	struct classinfo *parent = NULL;
363 	struct service_curve sc;
364 	int error = 0;
365 
366 	if ((ifinfo = ifname2ifinfo(ifname)) == NULL)
367 		error = QOPERR_BADIF;
368 
369 	if (error == 0 &&
370 	    (parent = clname2clinfo(ifinfo, parent_name)) == NULL)
371 		error = QOPERR_BADCLASS;
372 
373 	sc.m1 = m1;
374 	sc.d = d;
375 	sc.m2 = m2;
376 
377 	if (error == 0)
378 		error = qop_hfsc_add_class(NULL, class_name, ifinfo, parent,
379 					   &sc, qlimit, flags);
380 	if (error != 0)
381 		LOG(LOG_ERR, errno,
382 		    "hfsc: %s: can't add class '%s' on interface '%s'",
383 		    qoperror(error), class_name, ifname);
384 	return (error);
385 }
386 
387 int
388 qcmd_hfsc_modify_class(const char *ifname, const char *class_name,
389 		       u_int m1, u_int d, u_int m2, int sctype)
390 {
391 	struct ifinfo *ifinfo;
392 	struct classinfo *clinfo;
393 	struct service_curve sc;
394 
395 	if ((ifinfo = ifname2ifinfo(ifname)) == NULL)
396 		return (QOPERR_BADIF);
397 
398 	if ((clinfo = clname2clinfo(ifinfo, class_name)) == NULL)
399 		return (QOPERR_BADCLASS);
400 
401 	sc.m1 = m1;
402 	sc.d = d;
403 	sc.m2 = m2;
404 
405 	return qop_hfsc_modify_class(clinfo, &sc, sctype);
406 }
407 
408 /*
409  * qop api
410  */
411 int
412 qop_hfsc_add_if(struct ifinfo **rp, const char *ifname,
413 		u_int bandwidth, int flags)
414 {
415 	struct ifinfo *ifinfo = NULL;
416 	struct hfsc_ifinfo *hfsc_ifinfo = NULL;
417 	struct service_curve sc;
418 	int error;
419 
420 	if ((hfsc_ifinfo = calloc(1, sizeof(*hfsc_ifinfo))) == NULL)
421 		return (QOPERR_NOMEM);
422 
423 	error = qop_add_if(&ifinfo, ifname, bandwidth,
424 			   &hfsc_qdisc, hfsc_ifinfo);
425 	if (error != 0)
426 		goto err_ret;
427 
428 	/* set enable hook */
429 	ifinfo->enable_hook = qop_hfsc_enable_hook;
430 
431 	/* create root class */
432 	sc.m1 = bandwidth;
433 	sc.d = 0;
434 	sc.m2 = bandwidth;
435 	if ((error = qop_hfsc_add_class(&hfsc_ifinfo->root_class, "root",
436 					ifinfo, NULL, &sc, 0, 0)) != 0) {
437 		LOG(LOG_ERR, errno,
438 		    "hfsc: %s: can't create dummy root class on %s!",
439 		    qoperror(error), ifname);
440 		(void)qop_delete_if(ifinfo);
441 		return (QOPERR_CLASS);
442 	}
443 
444 	if (rp != NULL)
445 		*rp = ifinfo;
446 	return (0);
447 
448  err_ret:
449 	if (hfsc_ifinfo != NULL) {
450 		free(hfsc_ifinfo);
451 		if (ifinfo != NULL)
452 			ifinfo->private = NULL;
453 	}
454 	return (error);
455 }
456 
457 #define is_sc_null(sc)	(((sc) == NULL) || ((sc)->m1 == 0 && (sc)->m2 == 0))
458 
459 int
460 qop_hfsc_add_class(struct classinfo **rp, const char *class_name,
461 		   struct ifinfo *ifinfo, struct classinfo *parent,
462 		   struct service_curve *sc, int qlimit, int flags)
463 {
464 	struct classinfo *clinfo;
465 	struct hfsc_ifinfo *hfsc_ifinfo;
466 	struct hfsc_classinfo *hfsc_clinfo = NULL, *parent_clinfo = NULL;
467 	int error;
468 
469 	hfsc_ifinfo = ifinfo->private;
470 	if ((flags & HFCF_DEFAULTCLASS) && hfsc_ifinfo->default_class != NULL)
471 		return (QOPERR_CLASS_INVAL);
472 
473 	if (validate_sc(sc) != 0)
474 		return (QOPERR_INVAL);
475 
476 	/* admission control */
477 	if (parent != NULL && !is_sc_null(sc)) {
478 		parent_clinfo = parent->private;
479 		gsc_add_sc(&parent_clinfo->gen_rsc, sc);
480 		gsc_add_sc(&parent_clinfo->gen_fsc, sc);
481 		if (!is_gsc_under_sc(&parent_clinfo->gen_rsc,
482 				     &parent_clinfo->rsc) ||
483 		    !is_gsc_under_sc(&parent_clinfo->gen_fsc,
484 				     &parent_clinfo->fsc)) {
485 			/* admission control failure */
486 			error = QOPERR_ADMISSION_NOBW;
487 			goto err_ret;
488 		}
489 	}
490 
491 	if ((hfsc_clinfo = calloc(1, sizeof(*hfsc_clinfo))) == NULL) {
492 		error = QOPERR_NOMEM;
493 		goto err_ret;
494 	}
495 
496 	hfsc_clinfo->rsc = *sc;
497 	hfsc_clinfo->fsc = *sc;
498 	LIST_INIT(&hfsc_clinfo->gen_rsc);
499 	LIST_INIT(&hfsc_clinfo->gen_fsc);
500 	hfsc_clinfo->qlimit = qlimit;
501 	hfsc_clinfo->flags = flags;
502 
503 	if ((error = qop_add_class(&clinfo, class_name, ifinfo, parent,
504 				   hfsc_clinfo)) != 0)
505 		goto err_ret;
506 
507 	/* set delete hook */
508 	clinfo->delete_hook = qop_hfsc_delete_class_hook;
509 
510 	if (flags & HFCF_DEFAULTCLASS)
511 		hfsc_ifinfo->default_class = clinfo;
512 
513 	if (parent == NULL) {
514 		/*
515 		 * if this is a root class, reserve 20% of the real-time
516 		 * bandwidth for safety.
517 		 * many network cards are not able to saturate the wire,
518 		 * and if we allocate real-time traffic more than the
519 		 * maximum sending rate of the card, hfsc is no longer
520 		 * able to meet the delay bound requirements.
521 		 */
522 		hfsc_clinfo->rsc.m1 = hfsc_clinfo->rsc.m1 / 10 * 8;
523 		hfsc_clinfo->rsc.m2 = hfsc_clinfo->rsc.m2 / 10 * 8;
524 	}
525 
526 	if (rp != NULL)
527 		*rp = clinfo;
528 	return (0);
529 
530  err_ret:
531 	/* cancel admission control */
532 	if (parent != NULL && !is_sc_null(sc)) {
533 		gsc_sub_sc(&parent_clinfo->gen_rsc, sc);
534 		gsc_sub_sc(&parent_clinfo->gen_fsc, sc);
535 	}
536 
537 	if (hfsc_clinfo != NULL) {
538 		free(hfsc_clinfo);
539 		clinfo->private = NULL;
540 	}
541 
542 	return (error);
543 }
544 
545 /*
546  * this is called from qop_delete_class() before a class is destroyed
547  * for discipline specific cleanup.
548  */
549 static int
550 qop_hfsc_delete_class_hook(struct classinfo *clinfo)
551 {
552 	struct hfsc_classinfo *hfsc_clinfo, *parent_clinfo;
553 
554 	hfsc_clinfo = clinfo->private;
555 
556 	/* cancel admission control */
557 	if (clinfo->parent != NULL) {
558 		parent_clinfo = clinfo->parent->private;
559 
560 		gsc_sub_sc(&parent_clinfo->gen_rsc, &hfsc_clinfo->rsc);
561 		gsc_sub_sc(&parent_clinfo->gen_fsc, &hfsc_clinfo->fsc);
562 	}
563 
564 	gsc_destroy(&hfsc_clinfo->gen_rsc);
565 	gsc_destroy(&hfsc_clinfo->gen_fsc);
566 	return (0);
567 }
568 
569 int
570 qop_hfsc_modify_class(struct classinfo *clinfo,
571 		      struct service_curve *sc, int sctype)
572 {
573 	struct hfsc_classinfo *hfsc_clinfo, *parent_clinfo;
574 	struct service_curve rsc, fsc, usc;
575 	int error;
576 
577 	if (validate_sc(sc) != 0)
578 		return (QOPERR_INVAL);
579 
580 	hfsc_clinfo = clinfo->private;
581 	if (clinfo->parent == NULL)
582 		return (QOPERR_CLASS_INVAL);
583 	parent_clinfo = clinfo->parent->private;
584 
585 	/* save old service curves */
586 	rsc = hfsc_clinfo->rsc;
587 	fsc = hfsc_clinfo->fsc;
588 	usc = hfsc_clinfo->usc;
589 
590 	/* admission control */
591 	if (sctype & HFSC_REALTIMESC) {
592 		/* if the class has usc, rsc should be smaller than usc */
593 		if (!is_sc_null(&hfsc_clinfo->usc)) {
594 			gsc_head_t tmp_gen_rsc =
595 			    LIST_HEAD_INITIALIZER(tmp_gen_rsc);
596 
597 			gsc_add_sc(&tmp_gen_rsc, sc);
598 			if (!is_gsc_under_sc(&tmp_gen_rsc, &hfsc_clinfo->usc)) {
599 				gsc_destroy(&tmp_gen_rsc);
600 				return (QOPERR_ADMISSION);
601 			}
602 			gsc_destroy(&tmp_gen_rsc);
603 		}
604 
605 		if (!is_gsc_under_sc(&hfsc_clinfo->gen_rsc, sc)) {
606 			/* admission control failure */
607 			return (QOPERR_ADMISSION);
608 		}
609 
610 		gsc_sub_sc(&parent_clinfo->gen_rsc, &hfsc_clinfo->rsc);
611 		gsc_add_sc(&parent_clinfo->gen_rsc, sc);
612 		if (!is_gsc_under_sc(&parent_clinfo->gen_rsc,
613 				     &parent_clinfo->rsc)) {
614 			/* admission control failure */
615 			gsc_sub_sc(&parent_clinfo->gen_rsc, sc);
616 			gsc_add_sc(&parent_clinfo->gen_rsc, &hfsc_clinfo->rsc);
617 			return (QOPERR_ADMISSION_NOBW);
618 		}
619 		hfsc_clinfo->rsc = *sc;
620 	}
621 	if (sctype & HFSC_LINKSHARINGSC) {
622 		if (!is_gsc_under_sc(&hfsc_clinfo->gen_fsc, sc)) {
623 			/* admission control failure */
624 			return (QOPERR_ADMISSION);
625 		}
626 
627 		gsc_sub_sc(&parent_clinfo->gen_fsc, &hfsc_clinfo->fsc);
628 		gsc_add_sc(&parent_clinfo->gen_fsc, sc);
629 		if (!is_gsc_under_sc(&parent_clinfo->gen_fsc,
630 				     &parent_clinfo->fsc)) {
631 			/* admission control failure */
632 			gsc_sub_sc(&parent_clinfo->gen_fsc, sc);
633 			gsc_add_sc(&parent_clinfo->gen_fsc, &hfsc_clinfo->fsc);
634 			return (QOPERR_ADMISSION_NOBW);
635 		}
636 		hfsc_clinfo->fsc = *sc;
637 	}
638 	if (sctype & HFSC_UPPERLIMITSC) {
639 		if (!is_sc_null(sc)) {
640 			/* usc must be smaller than interface bandwidth */
641 			struct classinfo *root_clinfo =
642 			    clname2clinfo(clinfo->ifinfo, "root");
643 			if (root_clinfo != NULL) {
644 				struct hfsc_classinfo *root_hfsc_clinfo =
645 				    root_clinfo->private;
646 				if (!is_sc_null(&root_hfsc_clinfo->rsc)) {
647 					gsc_head_t tmp_gen_usc =
648 					    LIST_HEAD_INITIALIZER(tmp_gen_usc);
649 					gsc_add_sc(&tmp_gen_usc, sc);
650 					if (!is_gsc_under_sc(&tmp_gen_usc,
651 					    &root_hfsc_clinfo->fsc)) {
652 						/* illegal attempt to set
653 						   upper limit curve to be
654 						   greater than the interface
655 						   bandwidth */
656 						gsc_destroy(&tmp_gen_usc);
657 						return (QOPERR_ADMISSION);
658 					}
659 					gsc_destroy(&tmp_gen_usc);
660 				}
661 			}
662 			/* if this class has rsc, check that usc >= rsc */
663 			if (!is_sc_null(&hfsc_clinfo->rsc)) {
664 				gsc_head_t tmp_gen_rsc =
665 				    LIST_HEAD_INITIALIZER(tmp_gen_rsc);
666 				gsc_add_sc(&tmp_gen_rsc, &hfsc_clinfo->rsc);
667 				if (!is_gsc_under_sc(&tmp_gen_rsc, sc)) {
668 					/* illegal attempt to set upper limit
669 					   curve to be under the real-time
670 					   service curve */
671 					gsc_destroy(&tmp_gen_rsc);
672 					return (QOPERR_ADMISSION);
673 				}
674 				gsc_destroy(&tmp_gen_rsc);
675 			}
676 		}
677 		hfsc_clinfo->usc = *sc;
678 	}
679 
680 	error = qop_modify_class(clinfo, (void *)((long)sctype));
681 	if (error == 0)
682 		return (0);
683 
684 	/* modify failed!, restore the old service curves */
685 	if (sctype & HFSC_REALTIMESC) {
686 		gsc_sub_sc(&parent_clinfo->gen_rsc, sc);
687 		gsc_add_sc(&parent_clinfo->gen_rsc, &rsc);
688 		hfsc_clinfo->rsc = rsc;
689 	}
690 	if (sctype & HFSC_LINKSHARINGSC) {
691 		gsc_sub_sc(&parent_clinfo->gen_fsc, sc);
692 		gsc_add_sc(&parent_clinfo->gen_fsc, &fsc);
693 		hfsc_clinfo->fsc = fsc;
694 	}
695 	if (sctype & HFSC_UPPERLIMITSC) {
696 		hfsc_clinfo->usc = usc;
697 	}
698 	return (error);
699 }
700 
701 /*
702  * sanity check at enabling hfsc:
703  *  1. there must one default class for an interface
704  *  2. the default class must be a leaf class
705  *  3. an internal class should not have filters
706  * (rule 2 and 3 are due to the fact that the hfsc link-sharing algorithm
707  *  do not schedule internal classes.)
708  */
709 static int
710 qop_hfsc_enable_hook(struct ifinfo *ifinfo)
711 {
712 	struct hfsc_ifinfo *hfsc_ifinfo;
713 	struct classinfo *clinfo;
714 
715 	hfsc_ifinfo = ifinfo->private;
716 	if (hfsc_ifinfo->default_class == NULL) {
717 		LOG(LOG_ERR, 0, "hfsc: no default class on interface %s!",
718 		    ifinfo->ifname);
719 		return (QOPERR_CLASS);
720 	} else if (hfsc_ifinfo->default_class->child != NULL) {
721 		LOG(LOG_ERR, 0, "hfsc: default class on %s must be a leaf!",
722 		    ifinfo->ifname);
723 		return (QOPERR_CLASS);
724 	}
725 
726 	LIST_FOREACH(clinfo, &ifinfo->cllist, next) {
727 		if (clinfo->child != NULL && !LIST_EMPTY(&clinfo->fltrlist)) {
728 			LOG(LOG_ERR, 0,
729 			    "hfsc: internal class \"%s\" should not have a filter!",
730 			    clinfo->clname);
731 			return (QOPERR_CLASS);
732 		}
733 	}
734 
735 	return (0);
736 }
737 
738 static int
739 validate_sc(struct service_curve *sc)
740 {
741 	/* the 1st segment of a concave curve must be zero */
742 	if (sc->m1 < sc->m2 && sc->m1 != 0) {
743 		LOG(LOG_ERR, 0, "m1 must be 0 for convex!");
744 		return (-1);
745 	}
746 	if (sc->m1 > sc->m2 && sc->m2 == 0) {
747 		LOG(LOG_ERR, 0, "m2 must be nonzero for concave!");
748 		return (-1);
749 	}
750 	return (0);
751 }
752 
753 /*
754  * admission control using generalized service curve
755  */
756 #ifndef INFINITY
757 #define	INFINITY	HUGE_VAL  /* positive infinity defined in <math.h> */
758 #endif
759 
760 /* add a new service curve to a generilized service curve */
761 static void
762 gsc_add_sc(struct gen_sc *gsc, struct service_curve *sc)
763 {
764 	if (is_sc_null(sc))
765 		return;
766 	if (sc->d != 0)
767 		gsc_add_seg(gsc, 0, 0, (double)sc->d, (double)sc->m1);
768 	gsc_add_seg(gsc, (double)sc->d, 0, INFINITY, (double)sc->m2);
769 }
770 
771 /* subtract a service curve from a generilized service curve */
772 static void
773 gsc_sub_sc(struct gen_sc *gsc, struct service_curve *sc)
774 {
775 	if (is_sc_null(sc))
776 		return;
777 	if (sc->d != 0)
778 		gsc_sub_seg(gsc, 0, 0, (double)sc->d, (double)sc->m1);
779 	gsc_sub_seg(gsc, (double)sc->d, 0, INFINITY, (double)sc->m2);
780 }
781 
782 /*
783  * check whether all points of a generalized service curve have
784  * their y-coordinates no larger than a given two-piece linear
785  * service curve.
786  */
787 static int
788 is_gsc_under_sc(struct gen_sc *gsc, struct service_curve *sc)
789 {
790 	struct segment *s, *last, *end;
791 	double y;
792 
793 	if (is_sc_null(sc)) {
794 		if (LIST_EMPTY(gsc))
795 			return (1);
796 		LIST_FOREACH(s, gsc, _next) {
797 			if (s->m != 0)
798 				return (0);
799 		}
800 		return (1);
801 	}
802 	/*
803 	 * gsc has a dummy entry at the end with x = INFINITY.
804 	 * loop through up to this dummy entry.
805 	 */
806 	end = gsc_getentry(gsc, INFINITY);
807 	if (end == NULL)
808 		return (1);
809 	last = NULL;
810 	for (s = LIST_FIRST(gsc); s != end; s = LIST_NEXT(s, _next)) {
811 		if (s->y > sc_x2y(sc, s->x))
812 			return (0);
813 		last = s;
814 	}
815 	/* last now holds the real last segment */
816 	if (last == NULL)
817 		return (1);
818 	if (last->m > sc->m2)
819 		return (0);
820 	if (last->x < sc->d && last->m > sc->m1) {
821 		y = last->y + (sc->d - last->x) * last->m;
822 		if (y > sc_x2y(sc, sc->d))
823 			return (0);
824 	}
825 	return (1);
826 }
827 
828 static void
829 gsc_destroy(struct gen_sc *gsc)
830 {
831 	struct segment *s;
832 
833 	while ((s = LIST_FIRST(gsc)) != NULL) {
834 		LIST_REMOVE(s, _next);
835 		free(s);
836 	}
837 }
838 
839 /*
840  * return a segment entry starting at x.
841  * if gsc has no entry starting at x, a new entry is created at x.
842  */
843 static struct segment *
844 gsc_getentry(struct gen_sc *gsc, double x)
845 {
846 	struct segment *new, *prev, *s;
847 
848 	prev = NULL;
849 	LIST_FOREACH(s, gsc, _next) {
850 		if (s->x == x)
851 			return (s);	/* matching entry found */
852 		else if (s->x < x)
853 			prev = s;
854 		else
855 			break;
856 	}
857 
858 	/* we have to create a new entry */
859 	if ((new = calloc(1, sizeof(struct segment))) == NULL)
860 		return (NULL);
861 
862 	new->x = x;
863 	if (x == INFINITY || s == NULL)
864 		new->d = 0;
865 	else if (s->x == INFINITY)
866 		new->d = INFINITY;
867 	else
868 		new->d = s->x - x;
869 	if (prev == NULL) {
870 		/* insert the new entry at the head of the list */
871 		new->y = 0;
872 		new->m = 0;
873 		LIST_INSERT_HEAD(gsc, new, _next);
874 	} else {
875 		/*
876 		 * the start point intersects with the segment pointed by
877 		 * prev.  divide prev into 2 segments
878 		 */
879 		if (x == INFINITY) {
880 			prev->d = INFINITY;
881 			if (prev->m == 0)
882 				new->y = prev->y;
883 			else
884 				new->y = INFINITY;
885 		} else {
886 			prev->d = x - prev->x;
887 			new->y = prev->d * prev->m + prev->y;
888 		}
889 		new->m = prev->m;
890 		LIST_INSERT_AFTER(prev, new, _next);
891 	}
892 	return (new);
893 }
894 
895 /* add a segment to a generalized service curve */
896 static int
897 gsc_add_seg(struct gen_sc *gsc, double x, double y, double d, double m)
898 {
899 	struct segment *start, *end, *s;
900 	double x2;
901 
902 	if (d == INFINITY)
903 		x2 = INFINITY;
904 	else
905 		x2 = x + d;
906 	start = gsc_getentry(gsc, x);
907 	end   = gsc_getentry(gsc, x2);
908 	if (start == NULL || end == NULL)
909 		return (-1);
910 
911 	for (s = start; s != end; s = LIST_NEXT(s, _next)) {
912 		s->m += m;
913 		s->y += y + (s->x - x) * m;
914 	}
915 
916 	end = gsc_getentry(gsc, INFINITY);
917 	for (; s != end; s = LIST_NEXT(s, _next)) {
918 		s->y += m * d;
919 	}
920 
921 	return (0);
922 }
923 
924 /* subtract a segment from a generalized service curve */
925 static int
926 gsc_sub_seg(struct gen_sc *gsc, double x, double y, double d, double m)
927 {
928 	if (gsc_add_seg(gsc, x, y, d, -m) < 0)
929 		return (-1);
930 	gsc_compress(gsc);
931 	return (0);
932 }
933 
934 /*
935  * collapse adjacent segments with the same slope
936  */
937 static void
938 gsc_compress(struct gen_sc *gsc)
939 {
940 	struct segment *s, *next;
941 
942  again:
943 	LIST_FOREACH(s, gsc, _next) {
944 
945 		if ((next = LIST_NEXT(s, _next)) == NULL) {
946 			if (LIST_FIRST(gsc) == s && s->m == 0) {
947 				/*
948 				 * if this is the only entry and its
949 				 * slope is 0, it's a remaining dummy
950 				 * entry. we can discard it.
951 				 */
952 				LIST_REMOVE(s, _next);
953 				free(s);
954 			}
955 			break;
956 		}
957 
958 		if (s->x == next->x) {
959 			/* discard this entry */
960 			LIST_REMOVE(s, _next);
961 			free(s);
962 			goto again;
963 		} else if (s->m == next->m) {
964 			/* join the two entries */
965 			if (s->d != INFINITY && next->d != INFINITY)
966 				s->d += next->d;
967 			LIST_REMOVE(next, _next);
968 			free(next);
969 			goto again;
970 		}
971 	}
972 }
973 
974 /* get y-projection of a service curve */
975 static double
976 sc_x2y(struct service_curve *sc, double x)
977 {
978 	double y;
979 
980 	if (x <= (double)sc->d)
981 		/* y belongs to the 1st segment */
982 		y = x * (double)sc->m1;
983 	else
984 		/* y belongs to the 2nd segment */
985 		y = (double)sc->d * (double)sc->m1
986 			+ (x - (double)sc->d) * (double)sc->m2;
987 	return (y);
988 }
989 
990 /*
991  *  system call interfaces for qdisc_ops
992  */
993 static int
994 hfsc_attach(struct ifinfo *ifinfo)
995 {
996 	struct hfsc_attach attach;
997 
998 	if (hfsc_fd < 0 &&
999 	    (hfsc_fd = open(HFSC_DEVICE, O_RDWR)) < 0 &&
1000 	    (hfsc_fd = open_module(HFSC_DEVICE, O_RDWR)) < 0) {
1001 		LOG(LOG_ERR, errno, "HFSC open");
1002 		return (QOPERR_SYSCALL);
1003 	}
1004 
1005 	hfsc_refcount++;
1006 	memset(&attach, 0, sizeof(attach));
1007 	strncpy(attach.iface.hfsc_ifname, ifinfo->ifname, IFNAMSIZ);
1008 	attach.bandwidth = ifinfo->bandwidth;
1009 
1010 	if (ioctl(hfsc_fd, HFSC_IF_ATTACH, &attach) < 0)
1011 		return (QOPERR_SYSCALL);
1012 	return (0);
1013 }
1014 
1015 static int
1016 hfsc_detach(struct ifinfo *ifinfo)
1017 {
1018 	struct hfsc_interface iface;
1019 
1020 	memset(&iface, 0, sizeof(iface));
1021 	strncpy(iface.hfsc_ifname, ifinfo->ifname, IFNAMSIZ);
1022 
1023 	if (ioctl(hfsc_fd, HFSC_IF_DETACH, &iface) < 0)
1024 		return (QOPERR_SYSCALL);
1025 
1026 	if (--hfsc_refcount == 0) {
1027 		close(hfsc_fd);
1028 		hfsc_fd = -1;
1029 	}
1030 	return (0);
1031 }
1032 
1033 static int
1034 hfsc_clear(struct ifinfo *ifinfo)
1035 {
1036 	struct hfsc_interface iface;
1037 
1038 	memset(&iface, 0, sizeof(iface));
1039 	strncpy(iface.hfsc_ifname, ifinfo->ifname, IFNAMSIZ);
1040 
1041 	if (ioctl(hfsc_fd, HFSC_CLEAR_HIERARCHY, &iface) < 0)
1042 		return (QOPERR_SYSCALL);
1043 	return (0);
1044 }
1045 
1046 static int
1047 hfsc_enable(struct ifinfo *ifinfo)
1048 {
1049 	struct hfsc_interface iface;
1050 
1051 	memset(&iface, 0, sizeof(iface));
1052 	strncpy(iface.hfsc_ifname, ifinfo->ifname, IFNAMSIZ);
1053 
1054 	if (ioctl(hfsc_fd, HFSC_ENABLE, &iface) < 0)
1055 		return (QOPERR_SYSCALL);
1056 	return (0);
1057 }
1058 
1059 static int
1060 hfsc_disable(struct ifinfo *ifinfo)
1061 {
1062 	struct hfsc_interface iface;
1063 
1064 	memset(&iface, 0, sizeof(iface));
1065 	strncpy(iface.hfsc_ifname, ifinfo->ifname, IFNAMSIZ);
1066 
1067 	if (ioctl(hfsc_fd, HFSC_DISABLE, &iface) < 0)
1068 		return (QOPERR_SYSCALL);
1069 	return (0);
1070 }
1071 
1072 static int
1073 hfsc_add_class(struct classinfo *clinfo)
1074 {
1075 	struct hfsc_add_class class_add;
1076 	struct hfsc_classinfo *hfsc_clinfo;
1077 	struct hfsc_ifinfo *hfsc_ifinfo;
1078 
1079 	hfsc_ifinfo = clinfo->ifinfo->private;
1080 	hfsc_clinfo = clinfo->private;
1081 
1082 	memset(&class_add, 0, sizeof(class_add));
1083 	strncpy(class_add.iface.hfsc_ifname, clinfo->ifinfo->ifname, IFNAMSIZ);
1084 
1085 	if (clinfo->parent == NULL)
1086 		class_add.parent_handle = HFSC_NULLCLASS_HANDLE;
1087 	else
1088 		class_add.parent_handle = clinfo->parent->handle;
1089 
1090 	class_add.service_curve = hfsc_clinfo->rsc;
1091 	class_add.qlimit = hfsc_clinfo->qlimit;
1092 	class_add.flags = hfsc_clinfo->flags;
1093 
1094 	if (ioctl(hfsc_fd, HFSC_ADD_CLASS, &class_add) < 0) {
1095 		clinfo->handle = HFSC_NULLCLASS_HANDLE;
1096 		return (QOPERR_SYSCALL);
1097 	}
1098 	clinfo->handle = class_add.class_handle;
1099 	return (0);
1100 }
1101 
1102 static int
1103 hfsc_modify_class(struct classinfo *clinfo, void *arg)
1104 {
1105 	struct hfsc_modify_class class_mod;
1106 	struct hfsc_classinfo *hfsc_clinfo;
1107 	long sctype;
1108 
1109 	sctype = (long)arg;
1110 	hfsc_clinfo = clinfo->private;
1111 
1112 	memset(&class_mod, 0, sizeof(class_mod));
1113 	strncpy(class_mod.iface.hfsc_ifname, clinfo->ifinfo->ifname, IFNAMSIZ);
1114 	class_mod.class_handle = clinfo->handle;
1115 	if (sctype & HFSC_REALTIMESC)
1116 		class_mod.service_curve = hfsc_clinfo->rsc;
1117 	else if (sctype & HFSC_LINKSHARINGSC)
1118 		class_mod.service_curve = hfsc_clinfo->fsc;
1119 	else if (sctype & HFSC_UPPERLIMITSC)
1120 		class_mod.service_curve = hfsc_clinfo->usc;
1121 	else
1122 		return (QOPERR_INVAL);
1123 	class_mod.sctype = sctype;
1124 
1125 	if (ioctl(hfsc_fd, HFSC_MOD_CLASS, &class_mod) < 0)
1126 		return (QOPERR_SYSCALL);
1127 	return (0);
1128 }
1129 
1130 static int
1131 hfsc_delete_class(struct classinfo *clinfo)
1132 {
1133 	struct hfsc_delete_class class_delete;
1134 
1135 	if (clinfo->handle == HFSC_NULLCLASS_HANDLE)
1136 		return (0);
1137 
1138 	memset(&class_delete, 0, sizeof(class_delete));
1139 	strncpy(class_delete.iface.hfsc_ifname, clinfo->ifinfo->ifname,
1140 		IFNAMSIZ);
1141 	class_delete.class_handle = clinfo->handle;
1142 
1143 	if (ioctl(hfsc_fd, HFSC_DEL_CLASS, &class_delete) < 0)
1144 		return (QOPERR_SYSCALL);
1145 	return (0);
1146 }
1147 
1148 static int
1149 hfsc_add_filter(struct fltrinfo *fltrinfo)
1150 {
1151 	struct hfsc_add_filter fltr_add;
1152 
1153 	memset(&fltr_add, 0, sizeof(fltr_add));
1154 	strncpy(fltr_add.iface.hfsc_ifname, fltrinfo->clinfo->ifinfo->ifname,
1155 		IFNAMSIZ);
1156 	fltr_add.class_handle = fltrinfo->clinfo->handle;
1157 	fltr_add.filter = fltrinfo->fltr;
1158 
1159 	if (ioctl(hfsc_fd, HFSC_ADD_FILTER, &fltr_add) < 0)
1160 		return (QOPERR_SYSCALL);
1161 	fltrinfo->handle = fltr_add.filter_handle;
1162 	return (0);
1163 }
1164 
1165 static int
1166 hfsc_delete_filter(struct fltrinfo *fltrinfo)
1167 {
1168 	struct hfsc_delete_filter fltr_del;
1169 
1170 	memset(&fltr_del, 0, sizeof(fltr_del));
1171 	strncpy(fltr_del.iface.hfsc_ifname, fltrinfo->clinfo->ifinfo->ifname,
1172 		IFNAMSIZ);
1173 	fltr_del.filter_handle = fltrinfo->handle;
1174 
1175 	if (ioctl(hfsc_fd, HFSC_DEL_FILTER, &fltr_del) < 0)
1176 		return (QOPERR_SYSCALL);
1177 	return (0);
1178 }
1179