[NET_SCHED]: Fix endless loops caused by inaccurate qlen counters (part 1)
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / sched / sch_dsmark.c
CommitLineData
1da177e4
LT
1/* net/sched/sch_dsmark.c - Differentiated Services field marker */
2
3/* Written 1998-2000 by Werner Almesberger, EPFL ICA */
4
5
1da177e4
LT
6#include <linux/module.h>
7#include <linux/init.h>
8#include <linux/types.h>
9#include <linux/string.h>
10#include <linux/errno.h>
11#include <linux/skbuff.h>
12#include <linux/netdevice.h> /* for pkt_sched */
13#include <linux/rtnetlink.h>
14#include <net/pkt_sched.h>
15#include <net/dsfield.h>
16#include <net/inet_ecn.h>
17#include <asm/byteorder.h>
18
19
08e9cd1f 20#if 0 /* control */
1da177e4
LT
21#define DPRINTK(format,args...) printk(KERN_DEBUG format,##args)
22#else
23#define DPRINTK(format,args...)
24#endif
25
26#if 0 /* data */
27#define D2PRINTK(format,args...) printk(KERN_DEBUG format,##args)
28#else
29#define D2PRINTK(format,args...)
30#endif
31
32
af0d1141 33#define PRIV(sch) ((struct dsmark_qdisc_data *) qdisc_priv(sch))
1da177e4
LT
34
35
36/*
37 * classid class marking
38 * ------- ----- -------
39 * n/a 0 n/a
40 * x:0 1 use entry [0]
41 * ... ... ...
42 * x:y y>0 y+1 use entry [y]
43 * ... ... ...
44 * x:indices-1 indices use entry [indices-1]
45 * ... ... ...
46 * x:y y+1 use entry [y & (indices-1)]
47 * ... ... ...
48 * 0xffff 0x10000 use entry [indices-1]
49 */
50
51
52#define NO_DEFAULT_INDEX (1 << 16)
53
54struct dsmark_qdisc_data {
55 struct Qdisc *q;
56 struct tcf_proto *filter_list;
af0d1141
TG
57 u8 *mask; /* "owns" the array */
58 u8 *value;
59 u16 indices;
60 u32 default_index; /* index range is 0...0xffff */
1da177e4
LT
61 int set_tc_index;
62};
63
758cc43c
TG
64static inline int dsmark_valid_indices(u16 indices)
65{
66 while (indices != 1) {
67 if (indices & 1)
68 return 0;
69 indices >>= 1;
70 }
71
72 return 1;
73}
74
75static inline int dsmark_valid_index(struct dsmark_qdisc_data *p, u16 index)
76{
77 return (index <= p->indices && index > 0);
78}
1da177e4
LT
79
80/* ------------------------- Class/flow operations ------------------------- */
81
af0d1141
TG
82static int dsmark_graft(struct Qdisc *sch, unsigned long arg,
83 struct Qdisc *new, struct Qdisc **old)
1da177e4
LT
84{
85 struct dsmark_qdisc_data *p = PRIV(sch);
86
af0d1141
TG
87 DPRINTK("dsmark_graft(sch %p,[qdisc %p],new %p,old %p)\n",
88 sch, p, new, old);
486b53e5
TG
89
90 if (new == NULL) {
9f9afec4
PM
91 new = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops,
92 sch->handle);
486b53e5
TG
93 if (new == NULL)
94 new = &noop_qdisc;
95 }
96
1da177e4 97 sch_tree_lock(sch);
af0d1141
TG
98 *old = xchg(&p->q, new);
99 qdisc_reset(*old);
1da177e4 100 sch->q.qlen = 0;
af0d1141
TG
101 sch_tree_unlock(sch);
102
1da177e4
LT
103 return 0;
104}
105
1da177e4
LT
106static struct Qdisc *dsmark_leaf(struct Qdisc *sch, unsigned long arg)
107{
af0d1141 108 return PRIV(sch)->q;
1da177e4
LT
109}
110
af0d1141 111static unsigned long dsmark_get(struct Qdisc *sch, u32 classid)
1da177e4 112{
af0d1141
TG
113 DPRINTK("dsmark_get(sch %p,[qdisc %p],classid %x)\n",
114 sch, PRIV(sch), classid);
1da177e4 115
af0d1141 116 return TC_H_MIN(classid) + 1;
1da177e4
LT
117}
118
1da177e4 119static unsigned long dsmark_bind_filter(struct Qdisc *sch,
af0d1141 120 unsigned long parent, u32 classid)
1da177e4 121{
af0d1141 122 return dsmark_get(sch, classid);
1da177e4
LT
123}
124
1da177e4
LT
125static void dsmark_put(struct Qdisc *sch, unsigned long cl)
126{
127}
128
1da177e4 129static int dsmark_change(struct Qdisc *sch, u32 classid, u32 parent,
758cc43c 130 struct rtattr **tca, unsigned long *arg)
1da177e4
LT
131{
132 struct dsmark_qdisc_data *p = PRIV(sch);
133 struct rtattr *opt = tca[TCA_OPTIONS-1];
134 struct rtattr *tb[TCA_DSMARK_MAX];
758cc43c
TG
135 int err = -EINVAL;
136 u8 mask = 0;
1da177e4
LT
137
138 DPRINTK("dsmark_change(sch %p,[qdisc %p],classid %x,parent %x),"
758cc43c
TG
139 "arg 0x%lx\n", sch, p, classid, parent, *arg);
140
141 if (!dsmark_valid_index(p, *arg)) {
142 err = -ENOENT;
143 goto rtattr_failure;
1da177e4 144 }
1da177e4 145
758cc43c
TG
146 if (!opt || rtattr_parse_nested(tb, TCA_DSMARK_MAX, opt))
147 goto rtattr_failure;
148
149 if (tb[TCA_DSMARK_MASK-1])
150 mask = RTA_GET_U8(tb[TCA_DSMARK_MASK-1]);
151
152 if (tb[TCA_DSMARK_VALUE-1])
153 p->value[*arg-1] = RTA_GET_U8(tb[TCA_DSMARK_VALUE-1]);
154
155 if (tb[TCA_DSMARK_MASK-1])
156 p->mask[*arg-1] = mask;
157
158 err = 0;
159
160rtattr_failure:
161 return err;
162}
1da177e4 163
af0d1141 164static int dsmark_delete(struct Qdisc *sch, unsigned long arg)
1da177e4
LT
165{
166 struct dsmark_qdisc_data *p = PRIV(sch);
167
af0d1141 168 if (!dsmark_valid_index(p, arg))
1da177e4 169 return -EINVAL;
af0d1141 170
1da177e4
LT
171 p->mask[arg-1] = 0xff;
172 p->value[arg-1] = 0;
af0d1141 173
1da177e4
LT
174 return 0;
175}
176
1da177e4
LT
177static void dsmark_walk(struct Qdisc *sch,struct qdisc_walker *walker)
178{
179 struct dsmark_qdisc_data *p = PRIV(sch);
180 int i;
181
af0d1141
TG
182 DPRINTK("dsmark_walk(sch %p,[qdisc %p],walker %p)\n", sch, p, walker);
183
1da177e4
LT
184 if (walker->stop)
185 return;
af0d1141 186
1da177e4
LT
187 for (i = 0; i < p->indices; i++) {
188 if (p->mask[i] == 0xff && !p->value[i])
0451eb07 189 goto ignore;
1da177e4
LT
190 if (walker->count >= walker->skip) {
191 if (walker->fn(sch, i+1, walker) < 0) {
192 walker->stop = 1;
193 break;
194 }
195 }
0451eb07
TG
196ignore:
197 walker->count++;
1da177e4
LT
198 }
199}
200
1da177e4
LT
201static struct tcf_proto **dsmark_find_tcf(struct Qdisc *sch,unsigned long cl)
202{
af0d1141 203 return &PRIV(sch)->filter_list;
1da177e4
LT
204}
205
1da177e4
LT
206/* --------------------------- Qdisc operations ---------------------------- */
207
1da177e4
LT
208static int dsmark_enqueue(struct sk_buff *skb,struct Qdisc *sch)
209{
210 struct dsmark_qdisc_data *p = PRIV(sch);
af0d1141
TG
211 int err;
212
213 D2PRINTK("dsmark_enqueue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);
1da177e4 214
1da177e4
LT
215 if (p->set_tc_index) {
216 /* FIXME: Safe with non-linear skbs? --RR */
217 switch (skb->protocol) {
218 case __constant_htons(ETH_P_IP):
219 skb->tc_index = ipv4_get_dsfield(skb->nh.iph)
220 & ~INET_ECN_MASK;
221 break;
222 case __constant_htons(ETH_P_IPV6):
223 skb->tc_index = ipv6_get_dsfield(skb->nh.ipv6h)
224 & ~INET_ECN_MASK;
225 break;
226 default:
227 skb->tc_index = 0;
228 break;
229 };
230 }
af0d1141
TG
231
232 if (TC_H_MAJ(skb->priority) == sch->handle)
1da177e4 233 skb->tc_index = TC_H_MIN(skb->priority);
af0d1141
TG
234 else {
235 struct tcf_result res;
236 int result = tc_classify(skb, p->filter_list, &res);
237
238 D2PRINTK("result %d class 0x%04x\n", result, res.classid);
239
1da177e4
LT
240 switch (result) {
241#ifdef CONFIG_NET_CLS_POLICE
242 case TC_POLICE_SHOT:
243 kfree_skb(skb);
af0d1141
TG
244 sch->qstats.drops++;
245 return NET_XMIT_POLICED;
1da177e4
LT
246#if 0
247 case TC_POLICE_RECLASSIFY:
248 /* FIXME: what to do here ??? */
249#endif
250#endif
251 case TC_POLICE_OK:
252 skb->tc_index = TC_H_MIN(res.classid);
253 break;
254 case TC_POLICE_UNSPEC:
255 /* fall through */
256 default:
257 if (p->default_index != NO_DEFAULT_INDEX)
258 skb->tc_index = p->default_index;
259 break;
260 };
261 }
1da177e4 262
af0d1141
TG
263 err = p->q->enqueue(skb,p->q);
264 if (err != NET_XMIT_SUCCESS) {
1da177e4 265 sch->qstats.drops++;
af0d1141 266 return err;
1da177e4 267 }
af0d1141 268
1da177e4
LT
269 sch->bstats.bytes += skb->len;
270 sch->bstats.packets++;
271 sch->q.qlen++;
1da177e4 272
af0d1141
TG
273 return NET_XMIT_SUCCESS;
274}
1da177e4
LT
275
276static struct sk_buff *dsmark_dequeue(struct Qdisc *sch)
277{
278 struct dsmark_qdisc_data *p = PRIV(sch);
279 struct sk_buff *skb;
af0d1141
TG
280 u32 index;
281
282 D2PRINTK("dsmark_dequeue(sch %p,[qdisc %p])\n", sch, p);
1da177e4 283
1da177e4 284 skb = p->q->ops->dequeue(p->q);
af0d1141 285 if (skb == NULL)
1da177e4 286 return NULL;
af0d1141 287
1da177e4 288 sch->q.qlen--;
af0d1141
TG
289
290 index = skb->tc_index & (p->indices - 1);
291 D2PRINTK("index %d->%d\n", skb->tc_index, index);
292
1da177e4
LT
293 switch (skb->protocol) {
294 case __constant_htons(ETH_P_IP):
af0d1141
TG
295 ipv4_change_dsfield(skb->nh.iph, p->mask[index],
296 p->value[index]);
1da177e4
LT
297 break;
298 case __constant_htons(ETH_P_IPV6):
af0d1141
TG
299 ipv6_change_dsfield(skb->nh.ipv6h, p->mask[index],
300 p->value[index]);
1da177e4
LT
301 break;
302 default:
303 /*
304 * Only complain if a change was actually attempted.
305 * This way, we can send non-IP traffic through dsmark
306 * and don't need yet another qdisc as a bypass.
307 */
308 if (p->mask[index] != 0xff || p->value[index])
309 printk(KERN_WARNING "dsmark_dequeue: "
310 "unsupported protocol %d\n",
66c6f529 311 ntohs(skb->protocol));
1da177e4
LT
312 break;
313 };
af0d1141 314
1da177e4
LT
315 return skb;
316}
317
1da177e4
LT
318static int dsmark_requeue(struct sk_buff *skb,struct Qdisc *sch)
319{
1da177e4 320 struct dsmark_qdisc_data *p = PRIV(sch);
af0d1141 321 int err;
1da177e4 322
af0d1141
TG
323 D2PRINTK("dsmark_requeue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);
324
325 err = p->q->ops->requeue(skb, p->q);
326 if (err != NET_XMIT_SUCCESS) {
327 sch->qstats.drops++;
328 return err;
1da177e4 329 }
1da177e4 330
af0d1141
TG
331 sch->q.qlen++;
332 sch->qstats.requeues++;
333
334 return NET_XMIT_SUCCESS;
335}
1da177e4
LT
336
337static unsigned int dsmark_drop(struct Qdisc *sch)
338{
339 struct dsmark_qdisc_data *p = PRIV(sch);
340 unsigned int len;
341
af0d1141
TG
342 DPRINTK("dsmark_reset(sch %p,[qdisc %p])\n", sch, p);
343
344 if (p->q->ops->drop == NULL)
1da177e4 345 return 0;
af0d1141
TG
346
347 len = p->q->ops->drop(p->q);
348 if (len)
349 sch->q.qlen--;
350
1da177e4
LT
351 return len;
352}
353
758cc43c 354static int dsmark_init(struct Qdisc *sch, struct rtattr *opt)
1da177e4
LT
355{
356 struct dsmark_qdisc_data *p = PRIV(sch);
357 struct rtattr *tb[TCA_DSMARK_MAX];
758cc43c
TG
358 int err = -EINVAL;
359 u32 default_index = NO_DEFAULT_INDEX;
360 u16 indices;
361 u8 *mask;
362
363 DPRINTK("dsmark_init(sch %p,[qdisc %p],opt %p)\n", sch, p, opt);
364
365 if (!opt || rtattr_parse_nested(tb, TCA_DSMARK_MAX, opt) < 0)
366 goto errout;
367
368 indices = RTA_GET_U16(tb[TCA_DSMARK_INDICES-1]);
369 if (!indices || !dsmark_valid_indices(indices))
370 goto errout;
371
372 if (tb[TCA_DSMARK_DEFAULT_INDEX-1])
373 default_index = RTA_GET_U16(tb[TCA_DSMARK_DEFAULT_INDEX-1]);
374
375 mask = kmalloc(indices * 2, GFP_KERNEL);
376 if (mask == NULL) {
377 err = -ENOMEM;
378 goto errout;
1da177e4 379 }
758cc43c
TG
380
381 p->mask = mask;
382 memset(p->mask, 0xff, indices);
383
384 p->value = p->mask + indices;
385 memset(p->value, 0, indices);
386
387 p->indices = indices;
388 p->default_index = default_index;
389 p->set_tc_index = RTA_GET_FLAG(tb[TCA_DSMARK_SET_TC_INDEX-1]);
390
9f9afec4 391 p->q = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops, sch->handle);
758cc43c 392 if (p->q == NULL)
1da177e4 393 p->q = &noop_qdisc;
758cc43c
TG
394
395 DPRINTK("dsmark_init: qdisc %p\n", p->q);
396
397 err = 0;
398errout:
399rtattr_failure:
400 return err;
1da177e4
LT
401}
402
1da177e4
LT
403static void dsmark_reset(struct Qdisc *sch)
404{
405 struct dsmark_qdisc_data *p = PRIV(sch);
406
af0d1141 407 DPRINTK("dsmark_reset(sch %p,[qdisc %p])\n", sch, p);
1da177e4
LT
408 qdisc_reset(p->q);
409 sch->q.qlen = 0;
410}
411
1da177e4
LT
412static void dsmark_destroy(struct Qdisc *sch)
413{
414 struct dsmark_qdisc_data *p = PRIV(sch);
415 struct tcf_proto *tp;
416
af0d1141
TG
417 DPRINTK("dsmark_destroy(sch %p,[qdisc %p])\n", sch, p);
418
1da177e4
LT
419 while (p->filter_list) {
420 tp = p->filter_list;
421 p->filter_list = tp->next;
422 tcf_destroy(tp);
423 }
af0d1141 424
1da177e4
LT
425 qdisc_destroy(p->q);
426 kfree(p->mask);
427}
428
1da177e4 429static int dsmark_dump_class(struct Qdisc *sch, unsigned long cl,
02f23f09 430 struct sk_buff *skb, struct tcmsg *tcm)
1da177e4
LT
431{
432 struct dsmark_qdisc_data *p = PRIV(sch);
02f23f09 433 struct rtattr *opts = NULL;
1da177e4 434
02f23f09
TG
435 DPRINTK("dsmark_dump_class(sch %p,[qdisc %p],class %ld\n", sch, p, cl);
436
437 if (!dsmark_valid_index(p, cl))
1da177e4 438 return -EINVAL;
02f23f09
TG
439
440 tcm->tcm_handle = TC_H_MAKE(TC_H_MAJ(sch->handle), cl-1);
cdc7f8e3 441 tcm->tcm_info = p->q->handle;
02f23f09
TG
442
443 opts = RTA_NEST(skb, TCA_OPTIONS);
444 RTA_PUT_U8(skb,TCA_DSMARK_MASK, p->mask[cl-1]);
445 RTA_PUT_U8(skb,TCA_DSMARK_VALUE, p->value[cl-1]);
446
447 return RTA_NEST_END(skb, opts);
1da177e4
LT
448
449rtattr_failure:
02f23f09 450 return RTA_NEST_CANCEL(skb, opts);
1da177e4
LT
451}
452
453static int dsmark_dump(struct Qdisc *sch, struct sk_buff *skb)
454{
455 struct dsmark_qdisc_data *p = PRIV(sch);
02f23f09 456 struct rtattr *opts = NULL;
1da177e4 457
02f23f09
TG
458 opts = RTA_NEST(skb, TCA_OPTIONS);
459 RTA_PUT_U16(skb, TCA_DSMARK_INDICES, p->indices);
460
461 if (p->default_index != NO_DEFAULT_INDEX)
462 RTA_PUT_U16(skb, TCA_DSMARK_DEFAULT_INDEX, p->default_index);
1da177e4 463
1da177e4 464 if (p->set_tc_index)
02f23f09
TG
465 RTA_PUT_FLAG(skb, TCA_DSMARK_SET_TC_INDEX);
466
467 return RTA_NEST_END(skb, opts);
1da177e4
LT
468
469rtattr_failure:
02f23f09 470 return RTA_NEST_CANCEL(skb, opts);
1da177e4
LT
471}
472
473static struct Qdisc_class_ops dsmark_class_ops = {
474 .graft = dsmark_graft,
475 .leaf = dsmark_leaf,
476 .get = dsmark_get,
477 .put = dsmark_put,
478 .change = dsmark_change,
479 .delete = dsmark_delete,
480 .walk = dsmark_walk,
481 .tcf_chain = dsmark_find_tcf,
482 .bind_tcf = dsmark_bind_filter,
483 .unbind_tcf = dsmark_put,
484 .dump = dsmark_dump_class,
485};
486
487static struct Qdisc_ops dsmark_qdisc_ops = {
488 .next = NULL,
489 .cl_ops = &dsmark_class_ops,
490 .id = "dsmark",
491 .priv_size = sizeof(struct dsmark_qdisc_data),
492 .enqueue = dsmark_enqueue,
493 .dequeue = dsmark_dequeue,
494 .requeue = dsmark_requeue,
495 .drop = dsmark_drop,
496 .init = dsmark_init,
497 .reset = dsmark_reset,
498 .destroy = dsmark_destroy,
499 .change = NULL,
500 .dump = dsmark_dump,
501 .owner = THIS_MODULE,
502};
503
504static int __init dsmark_module_init(void)
505{
506 return register_qdisc(&dsmark_qdisc_ops);
507}
af0d1141 508
1da177e4
LT
509static void __exit dsmark_module_exit(void)
510{
511 unregister_qdisc(&dsmark_qdisc_ops);
512}
af0d1141 513
1da177e4
LT
514module_init(dsmark_module_init)
515module_exit(dsmark_module_exit)
af0d1141 516
1da177e4 517MODULE_LICENSE("GPL");