25c171c32715422123ca367663b81bb29da45c45
[linux-3.10.git] / net / sched / sch_gred.c
1 /*
2  * net/sched/sch_gred.c Generic Random Early Detection queue.
3  *
4  *
5  *              This program is free software; you can redistribute it and/or
6  *              modify it under the terms of the GNU General Public License
7  *              as published by the Free Software Foundation; either version
8  *              2 of the License, or (at your option) any later version.
9  *
10  * Authors:    J Hadi Salim (hadi@cyberus.ca) 1998-2002
11  *
12  *             991129: -  Bug fix with grio mode
13  *                     - a better sing. AvgQ mode with Grio(WRED)
14  *                     - A finer grained VQ dequeue based on sugestion
15  *                       from Ren Liu
16  *                     - More error checks
17  *
18  *
19  *
20  *  For all the glorious comments look at Alexey's sch_red.c
21  */
22
23 #include <linux/config.h>
24 #include <linux/module.h>
25 #include <asm/uaccess.h>
26 #include <asm/system.h>
27 #include <linux/bitops.h>
28 #include <linux/types.h>
29 #include <linux/kernel.h>
30 #include <linux/sched.h>
31 #include <linux/string.h>
32 #include <linux/mm.h>
33 #include <linux/socket.h>
34 #include <linux/sockios.h>
35 #include <linux/in.h>
36 #include <linux/errno.h>
37 #include <linux/interrupt.h>
38 #include <linux/if_ether.h>
39 #include <linux/inet.h>
40 #include <linux/netdevice.h>
41 #include <linux/etherdevice.h>
42 #include <linux/notifier.h>
43 #include <net/ip.h>
44 #include <net/route.h>
45 #include <linux/skbuff.h>
46 #include <net/sock.h>
47 #include <net/pkt_sched.h>
48
49 #if 1 /* control */
50 #define DPRINTK(format,args...) printk(KERN_DEBUG format,##args)
51 #else
52 #define DPRINTK(format,args...)
53 #endif
54
55 #if 0 /* data */
56 #define D2PRINTK(format,args...) printk(KERN_DEBUG format,##args)
57 #else
58 #define D2PRINTK(format,args...)
59 #endif
60
61 struct gred_sched_data;
62 struct gred_sched;
63
64 struct gred_sched_data
65 {
66 /* Parameters */
67         u32             limit;          /* HARD maximal queue length    */
68         u32             qth_min;        /* Min average length threshold: A scaled */
69         u32             qth_max;        /* Max average length threshold: A scaled */
70         u32             DP;             /* the drop pramaters */
71         char            Wlog;           /* log(W)               */
72         char            Plog;           /* random number bits   */
73         u32             Scell_max;
74         u32             Rmask;
75         u32             bytesin;        /* bytes seen on virtualQ so far*/
76         u32             packetsin;      /* packets seen on virtualQ so far*/
77         u32             backlog;        /* bytes on the virtualQ */
78         u32             forced; /* packets dropped for exceeding limits */
79         u32             early;  /* packets dropped as a warning */
80         u32             other;  /* packets dropped by invoking drop() */
81         u32             pdrop;  /* packets dropped because we exceeded physical queue limits */
82         char            Scell_log;
83         u8              Stab[256];
84         u8              prio;        /* the prio of this vq */
85
86 /* Variables */
87         unsigned long   qave;           /* Average queue length: A scaled */
88         int             qcount;         /* Packets since last random number generation */
89         u32             qR;             /* Cached random number */
90
91         psched_time_t   qidlestart;     /* Start of idle period */
92 };
93
94 struct gred_sched
95 {
96         struct gred_sched_data *tab[MAX_DPs];
97         u32             DPs;   
98         u32             def; 
99         u8              initd; 
100         u8              grio; 
101         u8              eqp; 
102 };
103
104 static int
105 gred_enqueue(struct sk_buff *skb, struct Qdisc* sch)
106 {
107         psched_time_t now;
108         struct gred_sched_data *q=NULL;
109         struct gred_sched *t= qdisc_priv(sch);
110         unsigned long   qave=0; 
111         int i=0;
112
113         if (!t->initd && skb_queue_len(&sch->q) < (sch->dev->tx_queue_len ? : 1)) {
114                 D2PRINTK("NO GRED Queues setup yet! Enqueued anyway\n");
115                 goto do_enqueue;
116         }
117
118
119         if ( ((skb->tc_index&0xf) > (t->DPs -1)) || !(q=t->tab[skb->tc_index&0xf])) {
120                 printk("GRED: setting to default (%d)\n ",t->def);
121                 if (!(q=t->tab[t->def])) {
122                         DPRINTK("GRED: setting to default FAILED! dropping!! "
123                             "(%d)\n ", t->def);
124                         goto drop;
125                 }
126                 /* fix tc_index? --could be controvesial but needed for
127                    requeueing */
128                 skb->tc_index=(skb->tc_index&0xfffffff0) | t->def;
129         }
130
131         D2PRINTK("gred_enqueue virtualQ 0x%x classid %x backlog %d "
132             "general backlog %d\n",skb->tc_index&0xf,sch->handle,q->backlog,
133             sch->qstats.backlog);
134         /* sum up all the qaves of prios <= to ours to get the new qave*/
135         if (!t->eqp && t->grio) {
136                 for (i=0;i<t->DPs;i++) {
137                         if ((!t->tab[i]) || (i==q->DP)) 
138                                 continue; 
139                                 
140                         if ((t->tab[i]->prio < q->prio) && (PSCHED_IS_PASTPERFECT(t->tab[i]->qidlestart)))
141                                 qave +=t->tab[i]->qave;
142                 }
143                         
144         }
145
146         q->packetsin++;
147         q->bytesin+=skb->len;
148
149         if (t->eqp && t->grio) {
150                 qave=0;
151                 q->qave=t->tab[t->def]->qave;
152                 q->qidlestart=t->tab[t->def]->qidlestart;
153         }
154
155         if (!PSCHED_IS_PASTPERFECT(q->qidlestart)) {
156                 long us_idle;
157                 PSCHED_GET_TIME(now);
158                 us_idle = PSCHED_TDIFF_SAFE(now, q->qidlestart, q->Scell_max);
159                 PSCHED_SET_PASTPERFECT(q->qidlestart);
160
161                 q->qave >>= q->Stab[(us_idle>>q->Scell_log)&0xFF];
162         } else {
163                 if (t->eqp) {
164                         q->qave += sch->qstats.backlog - (q->qave >> q->Wlog);
165                 } else {
166                         q->qave += q->backlog - (q->qave >> q->Wlog);
167                 }
168
169         }
170         
171
172         if (t->eqp && t->grio) 
173                 t->tab[t->def]->qave=q->qave;
174
175         if ((q->qave+qave) < q->qth_min) {
176                 q->qcount = -1;
177 enqueue:
178                 if (q->backlog + skb->len <= q->limit) {
179                         q->backlog += skb->len;
180 do_enqueue:
181                         __skb_queue_tail(&sch->q, skb);
182                         sch->qstats.backlog += skb->len;
183                         sch->bstats.bytes += skb->len;
184                         sch->bstats.packets++;
185                         return 0;
186                 } else {
187                         q->pdrop++;
188                 }
189
190 drop:
191                 kfree_skb(skb);
192                 sch->qstats.drops++;
193                 return NET_XMIT_DROP;
194         }
195         if ((q->qave+qave) >= q->qth_max) {
196                 q->qcount = -1;
197                 sch->qstats.overlimits++;
198                 q->forced++;
199                 goto drop;
200         }
201         if (++q->qcount) {
202                 if ((((qave+q->qave) - q->qth_min)>>q->Wlog)*q->qcount < q->qR)
203                         goto enqueue;
204                 q->qcount = 0;
205                 q->qR = net_random()&q->Rmask;
206                 sch->qstats.overlimits++;
207                 q->early++;
208                 goto drop;
209         }
210         q->qR = net_random()&q->Rmask;
211         goto enqueue;
212 }
213
214 static int
215 gred_requeue(struct sk_buff *skb, struct Qdisc* sch)
216 {
217         struct gred_sched_data *q;
218         struct gred_sched *t= qdisc_priv(sch);
219         q= t->tab[(skb->tc_index&0xf)];
220 /* error checking here -- probably unnecessary */
221         PSCHED_SET_PASTPERFECT(q->qidlestart);
222
223         __skb_queue_head(&sch->q, skb);
224         sch->qstats.backlog += skb->len;
225         sch->qstats.requeues++;
226         q->backlog += skb->len;
227         return 0;
228 }
229
230 static struct sk_buff *
231 gred_dequeue(struct Qdisc* sch)
232 {
233         struct sk_buff *skb;
234         struct gred_sched_data *q;
235         struct gred_sched *t= qdisc_priv(sch);
236
237         skb = __skb_dequeue(&sch->q);
238         if (skb) {
239                 sch->qstats.backlog -= skb->len;
240                 q= t->tab[(skb->tc_index&0xf)];
241                 if (q) {
242                         q->backlog -= skb->len;
243                         if (!q->backlog && !t->eqp)
244                                 PSCHED_GET_TIME(q->qidlestart);
245                 } else {
246                         D2PRINTK("gred_dequeue: skb has bad tcindex %x\n",skb->tc_index&0xf); 
247                 }
248                 return skb;
249         }
250
251         if (t->eqp) {
252                         q= t->tab[t->def];
253                         if (!q) 
254                                 D2PRINTK("no default VQ set: Results will be "
255                                        "screwed up\n");
256                         else
257                                 PSCHED_GET_TIME(q->qidlestart);
258         }
259
260         return NULL;
261 }
262
263 static unsigned int gred_drop(struct Qdisc* sch)
264 {
265         struct sk_buff *skb;
266
267         struct gred_sched_data *q;
268         struct gred_sched *t= qdisc_priv(sch);
269
270         skb = __skb_dequeue_tail(&sch->q);
271         if (skb) {
272                 unsigned int len = skb->len;
273                 sch->qstats.backlog -= len;
274                 sch->qstats.drops++;
275                 q= t->tab[(skb->tc_index&0xf)];
276                 if (q) {
277                         q->backlog -= len;
278                         q->other++;
279                         if (!q->backlog && !t->eqp)
280                                 PSCHED_GET_TIME(q->qidlestart);
281                 } else {
282                         D2PRINTK("gred_dequeue: skb has bad tcindex %x\n",skb->tc_index&0xf); 
283                 }
284
285                 kfree_skb(skb);
286                 return len;
287         }
288
289         q=t->tab[t->def];
290         if (!q) {
291                 D2PRINTK("no default VQ set: Results might be screwed up\n");
292                 return 0;
293         }
294
295         PSCHED_GET_TIME(q->qidlestart);
296         return 0;
297
298 }
299
300 static void gred_reset(struct Qdisc* sch)
301 {
302         int i;
303         struct gred_sched_data *q;
304         struct gred_sched *t= qdisc_priv(sch);
305
306         __skb_queue_purge(&sch->q);
307
308         sch->qstats.backlog = 0;
309
310         for (i=0;i<t->DPs;i++) {
311                 q= t->tab[i];
312                 if (!q) 
313                         continue; 
314                 PSCHED_SET_PASTPERFECT(q->qidlestart);
315                 q->qave = 0;
316                 q->qcount = -1;
317                 q->backlog = 0;
318                 q->other=0;
319                 q->forced=0;
320                 q->pdrop=0;
321                 q->early=0;
322         }
323 }
324
325 static int gred_change(struct Qdisc *sch, struct rtattr *opt)
326 {
327         struct gred_sched *table = qdisc_priv(sch);
328         struct gred_sched_data *q;
329         struct tc_gred_qopt *ctl;
330         struct tc_gred_sopt *sopt;
331         struct rtattr *tb[TCA_GRED_STAB];
332         struct rtattr *tb2[TCA_GRED_DPS];
333         int i;
334
335         if (opt == NULL || rtattr_parse_nested(tb, TCA_GRED_STAB, opt))
336                 return -EINVAL;
337
338         if (tb[TCA_GRED_PARMS-1] == 0 && tb[TCA_GRED_STAB-1] == 0) {
339                 rtattr_parse_nested(tb2, TCA_GRED_DPS, opt);
340
341             if (tb2[TCA_GRED_DPS-1] == 0) 
342                         return -EINVAL;
343
344                 sopt = RTA_DATA(tb2[TCA_GRED_DPS-1]);
345                 table->DPs=sopt->DPs;   
346                 table->def=sopt->def_DP; 
347                 table->grio=sopt->grio; 
348                 table->initd=0;
349                 /* probably need to clear all the table DP entries as well */
350                 return 0;
351             }
352
353
354         if (!table->DPs || tb[TCA_GRED_PARMS-1] == 0 || tb[TCA_GRED_STAB-1] == 0 ||
355                 RTA_PAYLOAD(tb[TCA_GRED_PARMS-1]) < sizeof(*ctl) ||
356                 RTA_PAYLOAD(tb[TCA_GRED_STAB-1]) < 256)
357                         return -EINVAL;
358
359         ctl = RTA_DATA(tb[TCA_GRED_PARMS-1]);
360         if (ctl->DP > MAX_DPs-1 ) {
361                 /* misbehaving is punished! Put in the default drop probability */
362                 DPRINTK("\nGRED: DP %u not in  the proper range fixed. New DP "
363                         "set to default at %d\n",ctl->DP,table->def);
364                 ctl->DP=table->def;
365         }
366         
367         if (table->tab[ctl->DP] == NULL) {
368                 table->tab[ctl->DP]=kmalloc(sizeof(struct gred_sched_data),
369                                             GFP_KERNEL);
370                 if (NULL == table->tab[ctl->DP])
371                         return -ENOMEM;
372                 memset(table->tab[ctl->DP], 0, (sizeof(struct gred_sched_data)));
373         }
374         q= table->tab[ctl->DP]; 
375
376         if (table->grio) {
377                 if (ctl->prio <=0) {
378                         if (table->def && table->tab[table->def]) {
379                                 DPRINTK("\nGRED: DP %u does not have a prio"
380                                         "setting default to %d\n",ctl->DP,
381                                         table->tab[table->def]->prio);
382                                 q->prio=table->tab[table->def]->prio;
383                         } else { 
384                                 DPRINTK("\nGRED: DP %u does not have a prio"
385                                         " setting default to 8\n",ctl->DP);
386                                 q->prio=8;
387                         }
388                 } else {
389                         q->prio=ctl->prio;
390                 }
391         } else {
392                 q->prio=8;
393         }
394
395
396         q->DP=ctl->DP;
397         q->Wlog = ctl->Wlog;
398         q->Plog = ctl->Plog;
399         q->limit = ctl->limit;
400         q->Scell_log = ctl->Scell_log;
401         q->Rmask = ctl->Plog < 32 ? ((1<<ctl->Plog) - 1) : ~0UL;
402         q->Scell_max = (255<<q->Scell_log);
403         q->qth_min = ctl->qth_min<<ctl->Wlog;
404         q->qth_max = ctl->qth_max<<ctl->Wlog;
405         q->qave=0;
406         q->backlog=0;
407         q->qcount = -1;
408         q->other=0;
409         q->forced=0;
410         q->pdrop=0;
411         q->early=0;
412
413         PSCHED_SET_PASTPERFECT(q->qidlestart);
414         memcpy(q->Stab, RTA_DATA(tb[TCA_GRED_STAB-1]), 256);
415
416         if ( table->initd && table->grio) {
417         /* this looks ugly but it's not in the fast path */
418                 for (i=0;i<table->DPs;i++) {
419                         if ((!table->tab[i]) || (i==q->DP) )    
420                                 continue; 
421                         if (table->tab[i]->prio == q->prio ){
422                                 /* WRED mode detected */
423                                 table->eqp=1;
424                                 break;
425                         }
426                 }
427         }
428
429         if (!table->initd) {
430                 table->initd=1;
431                 /* 
432                 the first entry also goes into the default until
433                 over-written 
434                 */
435
436                 if (table->tab[table->def] == NULL) {
437                         table->tab[table->def]=
438                                 kmalloc(sizeof(struct gred_sched_data), GFP_KERNEL);
439                         if (NULL == table->tab[table->def])
440                                 return -ENOMEM;
441
442                         memset(table->tab[table->def], 0,
443                                (sizeof(struct gred_sched_data)));
444                 }
445                 q= table->tab[table->def]; 
446                 q->DP=table->def;
447                 q->Wlog = ctl->Wlog;
448                 q->Plog = ctl->Plog;
449                 q->limit = ctl->limit;
450                 q->Scell_log = ctl->Scell_log;
451                 q->Rmask = ctl->Plog < 32 ? ((1<<ctl->Plog) - 1) : ~0UL;
452                 q->Scell_max = (255<<q->Scell_log);
453                 q->qth_min = ctl->qth_min<<ctl->Wlog;
454                 q->qth_max = ctl->qth_max<<ctl->Wlog;
455
456                 if (table->grio)
457                         q->prio=table->tab[ctl->DP]->prio;
458                 else
459                         q->prio=8;
460
461                 q->qcount = -1;
462                 PSCHED_SET_PASTPERFECT(q->qidlestart);
463                 memcpy(q->Stab, RTA_DATA(tb[TCA_GRED_STAB-1]), 256);
464         }
465         return 0;
466
467 }
468
469 static int gred_init(struct Qdisc *sch, struct rtattr *opt)
470 {
471         struct gred_sched *table = qdisc_priv(sch);
472         struct tc_gred_sopt *sopt;
473         struct rtattr *tb[TCA_GRED_STAB];
474         struct rtattr *tb2[TCA_GRED_DPS];
475
476         if (opt == NULL || rtattr_parse_nested(tb, TCA_GRED_STAB, opt))
477                 return -EINVAL;
478
479         if (tb[TCA_GRED_PARMS-1] == 0 && tb[TCA_GRED_STAB-1] == 0) {
480                 rtattr_parse_nested(tb2, TCA_GRED_DPS, opt);
481
482             if (tb2[TCA_GRED_DPS-1] == 0) 
483                         return -EINVAL;
484
485                 sopt = RTA_DATA(tb2[TCA_GRED_DPS-1]);
486                 table->DPs=sopt->DPs;   
487                 table->def=sopt->def_DP; 
488                 table->grio=sopt->grio; 
489                 table->initd=0;
490                 return 0;
491         }
492
493         DPRINTK("\n GRED_INIT error!\n");
494         return -EINVAL;
495 }
496
497 static int gred_dump(struct Qdisc *sch, struct sk_buff *skb)
498 {
499         unsigned long qave;
500         struct rtattr *rta;
501         struct tc_gred_qopt *opt = NULL ;
502         struct tc_gred_qopt *dst;
503         struct gred_sched *table = qdisc_priv(sch);
504         struct gred_sched_data *q;
505         int i;
506         unsigned char    *b = skb->tail;
507
508         rta = (struct rtattr*)b;
509         RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
510
511         opt=kmalloc(sizeof(struct tc_gred_qopt)*MAX_DPs, GFP_KERNEL);
512
513         if (opt  == NULL) {
514                 DPRINTK("gred_dump:failed to malloc for %Zd\n",
515                     sizeof(struct tc_gred_qopt)*MAX_DPs);
516                 goto rtattr_failure;
517         }
518
519         memset(opt, 0, (sizeof(struct tc_gred_qopt))*table->DPs);
520
521         if (!table->initd) {
522                 DPRINTK("NO GRED Queues setup!\n");
523         }
524
525         for (i=0;i<MAX_DPs;i++) {
526                 dst= &opt[i]; 
527                 q= table->tab[i]; 
528
529                 if (!q) {
530                         /* hack -- fix at some point with proper message
531                            This is how we indicate to tc that there is no VQ
532                            at this DP */
533
534                         dst->DP=MAX_DPs+i;
535                         continue;
536                 }
537
538                 dst->limit=q->limit;
539                 dst->qth_min=q->qth_min>>q->Wlog;
540                 dst->qth_max=q->qth_max>>q->Wlog;
541                 dst->DP=q->DP;
542                 dst->backlog=q->backlog;
543                 if (q->qave) {
544                         if (table->eqp && table->grio) {
545                                 q->qidlestart=table->tab[table->def]->qidlestart;
546                                 q->qave=table->tab[table->def]->qave;
547                         }
548                         if (!PSCHED_IS_PASTPERFECT(q->qidlestart)) {
549                                 long idle;
550                                 psched_time_t now;
551                                 PSCHED_GET_TIME(now);
552                                 idle = PSCHED_TDIFF_SAFE(now, q->qidlestart, q->Scell_max);
553                                 qave  = q->qave >> q->Stab[(idle>>q->Scell_log)&0xFF];
554                                 dst->qave = qave >> q->Wlog;
555
556                         } else {
557                                 dst->qave = q->qave >> q->Wlog;
558                         }
559                 } else {
560                         dst->qave = 0;
561                 }
562                 
563
564                 dst->Wlog = q->Wlog;
565                 dst->Plog = q->Plog;
566                 dst->Scell_log = q->Scell_log;
567                 dst->other = q->other;
568                 dst->forced = q->forced;
569                 dst->early = q->early;
570                 dst->pdrop = q->pdrop;
571                 dst->prio = q->prio;
572                 dst->packets=q->packetsin;
573                 dst->bytesin=q->bytesin;
574         }
575
576         RTA_PUT(skb, TCA_GRED_PARMS, sizeof(struct tc_gred_qopt)*MAX_DPs, opt);
577         rta->rta_len = skb->tail - b;
578
579         kfree(opt);
580         return skb->len;
581
582 rtattr_failure:
583         if (opt)
584                 kfree(opt);
585         DPRINTK("gred_dump: FAILURE!!!!\n");
586
587 /* also free the opt struct here */
588         skb_trim(skb, b - skb->data);
589         return -1;
590 }
591
592 static void gred_destroy(struct Qdisc *sch)
593 {
594         struct gred_sched *table = qdisc_priv(sch);
595         int i;
596
597         for (i = 0;i < table->DPs; i++) {
598                 if (table->tab[i])
599                         kfree(table->tab[i]);
600         }
601 }
602
603 static struct Qdisc_ops gred_qdisc_ops = {
604         .next           =       NULL,
605         .cl_ops         =       NULL,
606         .id             =       "gred",
607         .priv_size      =       sizeof(struct gred_sched),
608         .enqueue        =       gred_enqueue,
609         .dequeue        =       gred_dequeue,
610         .requeue        =       gred_requeue,
611         .drop           =       gred_drop,
612         .init           =       gred_init,
613         .reset          =       gred_reset,
614         .destroy        =       gred_destroy,
615         .change         =       gred_change,
616         .dump           =       gred_dump,
617         .owner          =       THIS_MODULE,
618 };
619
620 static int __init gred_module_init(void)
621 {
622         return register_qdisc(&gred_qdisc_ops);
623 }
624 static void __exit gred_module_exit(void) 
625 {
626         unregister_qdisc(&gred_qdisc_ops);
627 }
628 module_init(gred_module_init)
629 module_exit(gred_module_exit)
630 MODULE_LICENSE("GPL");