usb: gadget: f_mtp: Avoid race between mtp_read and mtp_function_disable
[GitHub/exynos8895/android_kernel_samsung_universal8895.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>
5a0e3ad6 8#include <linux/slab.h>
1da177e4
LT
9#include <linux/types.h>
10#include <linux/string.h>
11#include <linux/errno.h>
12#include <linux/skbuff.h>
1da177e4 13#include <linux/rtnetlink.h>
5b0ac72b 14#include <linux/bitops.h>
1da177e4
LT
15#include <net/pkt_sched.h>
16#include <net/dsfield.h>
17#include <net/inet_ecn.h>
18#include <asm/byteorder.h>
19
1da177e4
LT
20/*
21 * classid class marking
22 * ------- ----- -------
23 * n/a 0 n/a
24 * x:0 1 use entry [0]
25 * ... ... ...
26 * x:y y>0 y+1 use entry [y]
27 * ... ... ...
28 * x:indices-1 indices use entry [indices-1]
29 * ... ... ...
30 * x:y y+1 use entry [y & (indices-1)]
31 * ... ... ...
32 * 0xffff 0x10000 use entry [indices-1]
33 */
34
35
36#define NO_DEFAULT_INDEX (1 << 16)
37
47bbbb30
ED
38struct mask_value {
39 u8 mask;
40 u8 value;
41};
42
1da177e4
LT
43struct dsmark_qdisc_data {
44 struct Qdisc *q;
25d8c0d5 45 struct tcf_proto __rcu *filter_list;
47bbbb30 46 struct mask_value *mv;
af0d1141 47 u16 indices;
47bbbb30 48 u8 set_tc_index;
af0d1141 49 u32 default_index; /* index range is 0...0xffff */
47bbbb30
ED
50#define DSMARK_EMBEDDED_SZ 16
51 struct mask_value embedded[DSMARK_EMBEDDED_SZ];
1da177e4
LT
52};
53
758cc43c
TG
54static inline int dsmark_valid_index(struct dsmark_qdisc_data *p, u16 index)
55{
17569fae 56 return index <= p->indices && index > 0;
758cc43c 57}
1da177e4
LT
58
59/* ------------------------- Class/flow operations ------------------------- */
60
af0d1141
TG
61static int dsmark_graft(struct Qdisc *sch, unsigned long arg,
62 struct Qdisc *new, struct Qdisc **old)
1da177e4 63{
81da99ed 64 struct dsmark_qdisc_data *p = qdisc_priv(sch);
1da177e4 65
c76f2a2c
YY
66 pr_debug("%s(sch %p,[qdisc %p],new %p,old %p)\n",
67 __func__, sch, p, new, old);
486b53e5
TG
68
69 if (new == NULL) {
3511c913 70 new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
9f9afec4 71 sch->handle);
486b53e5
TG
72 if (new == NULL)
73 new = &noop_qdisc;
74 }
75
1188e140 76 *old = qdisc_replace(sch, new, &p->q);
10297b99 77 return 0;
1da177e4
LT
78}
79
1da177e4
LT
80static struct Qdisc *dsmark_leaf(struct Qdisc *sch, unsigned long arg)
81{
81da99ed
SH
82 struct dsmark_qdisc_data *p = qdisc_priv(sch);
83 return p->q;
1da177e4
LT
84}
85
af0d1141 86static unsigned long dsmark_get(struct Qdisc *sch, u32 classid)
1da177e4 87{
c76f2a2c
YY
88 pr_debug("%s(sch %p,[qdisc %p],classid %x)\n",
89 __func__, sch, qdisc_priv(sch), classid);
1da177e4 90
af0d1141 91 return TC_H_MIN(classid) + 1;
1da177e4
LT
92}
93
1da177e4 94static unsigned long dsmark_bind_filter(struct Qdisc *sch,
af0d1141 95 unsigned long parent, u32 classid)
1da177e4 96{
af0d1141 97 return dsmark_get(sch, classid);
1da177e4
LT
98}
99
1da177e4
LT
100static void dsmark_put(struct Qdisc *sch, unsigned long cl)
101{
102}
103
27a3421e
PM
104static const struct nla_policy dsmark_policy[TCA_DSMARK_MAX + 1] = {
105 [TCA_DSMARK_INDICES] = { .type = NLA_U16 },
106 [TCA_DSMARK_DEFAULT_INDEX] = { .type = NLA_U16 },
107 [TCA_DSMARK_SET_TC_INDEX] = { .type = NLA_FLAG },
108 [TCA_DSMARK_MASK] = { .type = NLA_U8 },
109 [TCA_DSMARK_VALUE] = { .type = NLA_U8 },
110};
111
1da177e4 112static int dsmark_change(struct Qdisc *sch, u32 classid, u32 parent,
1e90474c 113 struct nlattr **tca, unsigned long *arg)
1da177e4 114{
81da99ed 115 struct dsmark_qdisc_data *p = qdisc_priv(sch);
1e90474c
PM
116 struct nlattr *opt = tca[TCA_OPTIONS];
117 struct nlattr *tb[TCA_DSMARK_MAX + 1];
758cc43c 118 int err = -EINVAL;
1da177e4 119
c76f2a2c
YY
120 pr_debug("%s(sch %p,[qdisc %p],classid %x,parent %x), arg 0x%lx\n",
121 __func__, sch, p, classid, parent, *arg);
758cc43c
TG
122
123 if (!dsmark_valid_index(p, *arg)) {
124 err = -ENOENT;
1e90474c 125 goto errout;
1da177e4 126 }
1da177e4 127
cee63723 128 if (!opt)
1e90474c 129 goto errout;
758cc43c 130
27a3421e 131 err = nla_parse_nested(tb, TCA_DSMARK_MAX, opt, dsmark_policy);
cee63723 132 if (err < 0)
27a3421e 133 goto errout;
cee63723 134
27a3421e 135 if (tb[TCA_DSMARK_VALUE])
47bbbb30 136 p->mv[*arg - 1].value = nla_get_u8(tb[TCA_DSMARK_VALUE]);
10297b99 137
1e90474c 138 if (tb[TCA_DSMARK_MASK])
47bbbb30 139 p->mv[*arg - 1].mask = nla_get_u8(tb[TCA_DSMARK_MASK]);
758cc43c
TG
140
141 err = 0;
142
1e90474c 143errout:
758cc43c
TG
144 return err;
145}
1da177e4 146
af0d1141 147static int dsmark_delete(struct Qdisc *sch, unsigned long arg)
1da177e4 148{
81da99ed 149 struct dsmark_qdisc_data *p = qdisc_priv(sch);
1da177e4 150
af0d1141 151 if (!dsmark_valid_index(p, arg))
1da177e4 152 return -EINVAL;
10297b99 153
47bbbb30
ED
154 p->mv[arg - 1].mask = 0xff;
155 p->mv[arg - 1].value = 0;
af0d1141 156
1da177e4
LT
157 return 0;
158}
159
9d127fbd 160static void dsmark_walk(struct Qdisc *sch, struct qdisc_walker *walker)
1da177e4 161{
81da99ed 162 struct dsmark_qdisc_data *p = qdisc_priv(sch);
1da177e4
LT
163 int i;
164
c76f2a2c
YY
165 pr_debug("%s(sch %p,[qdisc %p],walker %p)\n",
166 __func__, sch, p, walker);
af0d1141 167
1da177e4
LT
168 if (walker->stop)
169 return;
af0d1141 170
1da177e4 171 for (i = 0; i < p->indices; i++) {
47bbbb30 172 if (p->mv[i].mask == 0xff && !p->mv[i].value)
0451eb07 173 goto ignore;
1da177e4 174 if (walker->count >= walker->skip) {
cc7ec456 175 if (walker->fn(sch, i + 1, walker) < 0) {
1da177e4
LT
176 walker->stop = 1;
177 break;
178 }
179 }
10297b99 180ignore:
0451eb07 181 walker->count++;
10297b99 182 }
1da177e4
LT
183}
184
25d8c0d5
JF
185static inline struct tcf_proto __rcu **dsmark_find_tcf(struct Qdisc *sch,
186 unsigned long cl)
1da177e4 187{
81da99ed
SH
188 struct dsmark_qdisc_data *p = qdisc_priv(sch);
189 return &p->filter_list;
1da177e4
LT
190}
191
1da177e4
LT
192/* --------------------------- Qdisc operations ---------------------------- */
193
9d127fbd 194static int dsmark_enqueue(struct sk_buff *skb, struct Qdisc *sch)
1da177e4 195{
81da99ed 196 struct dsmark_qdisc_data *p = qdisc_priv(sch);
af0d1141
TG
197 int err;
198
c76f2a2c 199 pr_debug("%s(skb %p,sch %p,[qdisc %p])\n", __func__, skb, sch, p);
1da177e4 200
1da177e4 201 if (p->set_tc_index) {
ffde339b
ED
202 int wlen = skb_network_offset(skb);
203
d8b9605d 204 switch (tc_skb_protocol(skb)) {
60678040 205 case htons(ETH_P_IP):
ffde339b
ED
206 wlen += sizeof(struct iphdr);
207 if (!pskb_may_pull(skb, wlen) ||
208 skb_try_make_writable(skb, wlen))
9d127fbd 209 goto drop;
4c30719f 210
9d127fbd
SH
211 skb->tc_index = ipv4_get_dsfield(ip_hdr(skb))
212 & ~INET_ECN_MASK;
213 break;
4c30719f 214
60678040 215 case htons(ETH_P_IPV6):
ffde339b
ED
216 wlen += sizeof(struct ipv6hdr);
217 if (!pskb_may_pull(skb, wlen) ||
218 skb_try_make_writable(skb, wlen))
9d127fbd 219 goto drop;
4c30719f 220
9d127fbd
SH
221 skb->tc_index = ipv6_get_dsfield(ipv6_hdr(skb))
222 & ~INET_ECN_MASK;
223 break;
224 default:
225 skb->tc_index = 0;
226 break;
3ff50b79 227 }
1da177e4 228 }
af0d1141
TG
229
230 if (TC_H_MAJ(skb->priority) == sch->handle)
1da177e4 231 skb->tc_index = TC_H_MIN(skb->priority);
af0d1141
TG
232 else {
233 struct tcf_result res;
25d8c0d5 234 struct tcf_proto *fl = rcu_dereference_bh(p->filter_list);
3b3ae880 235 int result = tc_classify(skb, fl, &res, false);
af0d1141 236
81da99ed 237 pr_debug("result %d class 0x%04x\n", result, res.classid);
af0d1141 238
1da177e4 239 switch (result) {
f6853e2d
PM
240#ifdef CONFIG_NET_CLS_ACT
241 case TC_ACT_QUEUED:
242 case TC_ACT_STOLEN:
243 kfree_skb(skb);
378a2f09 244 return NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
4c30719f 245
f6853e2d 246 case TC_ACT_SHOT:
4c30719f 247 goto drop;
1da177e4 248#endif
c3bc7cff 249 case TC_ACT_OK:
f6853e2d
PM
250 skb->tc_index = TC_H_MIN(res.classid);
251 break;
4c30719f 252
f6853e2d
PM
253 default:
254 if (p->default_index != NO_DEFAULT_INDEX)
255 skb->tc_index = p->default_index;
256 break;
3ff50b79 257 }
1da177e4 258 }
1da177e4 259
5f86173b 260 err = qdisc_enqueue(skb, p->q);
af0d1141 261 if (err != NET_XMIT_SUCCESS) {
378a2f09 262 if (net_xmit_drop_count(err))
25331d6c 263 qdisc_qstats_drop(sch);
af0d1141 264 return err;
1da177e4 265 }
af0d1141 266
5ecc98e1 267 qdisc_qstats_backlog_inc(sch, skb);
1da177e4 268 sch->q.qlen++;
1da177e4 269
af0d1141 270 return NET_XMIT_SUCCESS;
4c30719f
SH
271
272drop:
17045755 273 qdisc_drop(skb, sch);
c27f339a 274 return NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
af0d1141 275}
1da177e4
LT
276
277static struct sk_buff *dsmark_dequeue(struct Qdisc *sch)
278{
81da99ed 279 struct dsmark_qdisc_data *p = qdisc_priv(sch);
1da177e4 280 struct sk_buff *skb;
af0d1141
TG
281 u32 index;
282
c76f2a2c 283 pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
1da177e4 284
1da177e4 285 skb = p->q->ops->dequeue(p->q);
af0d1141 286 if (skb == NULL)
1da177e4 287 return NULL;
af0d1141 288
9190b3b3 289 qdisc_bstats_update(sch, skb);
5ecc98e1 290 qdisc_qstats_backlog_dec(sch, skb);
1da177e4 291 sch->q.qlen--;
af0d1141
TG
292
293 index = skb->tc_index & (p->indices - 1);
81da99ed 294 pr_debug("index %d->%d\n", skb->tc_index, index);
af0d1141 295
d8b9605d 296 switch (tc_skb_protocol(skb)) {
60678040 297 case htons(ETH_P_IP):
47bbbb30
ED
298 ipv4_change_dsfield(ip_hdr(skb), p->mv[index].mask,
299 p->mv[index].value);
1da177e4 300 break;
60678040 301 case htons(ETH_P_IPV6):
47bbbb30
ED
302 ipv6_change_dsfield(ipv6_hdr(skb), p->mv[index].mask,
303 p->mv[index].value);
1da177e4 304 break;
9d127fbd
SH
305 default:
306 /*
307 * Only complain if a change was actually attempted.
308 * This way, we can send non-IP traffic through dsmark
309 * and don't need yet another qdisc as a bypass.
310 */
47bbbb30 311 if (p->mv[index].mask != 0xff || p->mv[index].value)
c76f2a2c 312 pr_warn("%s: unsupported protocol %d\n",
d8b9605d 313 __func__, ntohs(tc_skb_protocol(skb)));
9d127fbd 314 break;
3ff50b79 315 }
af0d1141 316
1da177e4
LT
317 return skb;
318}
319
8e3af978
JP
320static struct sk_buff *dsmark_peek(struct Qdisc *sch)
321{
322 struct dsmark_qdisc_data *p = qdisc_priv(sch);
323
c76f2a2c 324 pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
8e3af978
JP
325
326 return p->q->ops->peek(p->q);
327}
328
1da177e4
LT
329static unsigned int dsmark_drop(struct Qdisc *sch)
330{
81da99ed 331 struct dsmark_qdisc_data *p = qdisc_priv(sch);
1da177e4 332 unsigned int len;
10297b99 333
c76f2a2c 334 pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
af0d1141
TG
335
336 if (p->q->ops->drop == NULL)
1da177e4 337 return 0;
af0d1141
TG
338
339 len = p->q->ops->drop(p->q);
340 if (len)
341 sch->q.qlen--;
342
1da177e4
LT
343 return len;
344}
345
1e90474c 346static int dsmark_init(struct Qdisc *sch, struct nlattr *opt)
1da177e4 347{
81da99ed 348 struct dsmark_qdisc_data *p = qdisc_priv(sch);
1e90474c 349 struct nlattr *tb[TCA_DSMARK_MAX + 1];
758cc43c
TG
350 int err = -EINVAL;
351 u32 default_index = NO_DEFAULT_INDEX;
352 u16 indices;
47bbbb30 353 int i;
758cc43c 354
c76f2a2c 355 pr_debug("%s(sch %p,[qdisc %p],opt %p)\n", __func__, sch, p, opt);
758cc43c 356
cee63723
PM
357 if (!opt)
358 goto errout;
359
27a3421e 360 err = nla_parse_nested(tb, TCA_DSMARK_MAX, opt, dsmark_policy);
cee63723 361 if (err < 0)
758cc43c
TG
362 goto errout;
363
cee63723 364 err = -EINVAL;
1e90474c 365 indices = nla_get_u16(tb[TCA_DSMARK_INDICES]);
5b0ac72b
DM
366
367 if (hweight32(indices) != 1)
758cc43c
TG
368 goto errout;
369
27a3421e 370 if (tb[TCA_DSMARK_DEFAULT_INDEX])
1e90474c 371 default_index = nla_get_u16(tb[TCA_DSMARK_DEFAULT_INDEX]);
758cc43c 372
47bbbb30
ED
373 if (indices <= DSMARK_EMBEDDED_SZ)
374 p->mv = p->embedded;
375 else
376 p->mv = kmalloc_array(indices, sizeof(*p->mv), GFP_KERNEL);
377 if (!p->mv) {
758cc43c
TG
378 err = -ENOMEM;
379 goto errout;
1da177e4 380 }
47bbbb30
ED
381 for (i = 0; i < indices; i++) {
382 p->mv[i].mask = 0xff;
383 p->mv[i].value = 0;
384 }
758cc43c
TG
385 p->indices = indices;
386 p->default_index = default_index;
1e90474c 387 p->set_tc_index = nla_get_flag(tb[TCA_DSMARK_SET_TC_INDEX]);
758cc43c 388
3511c913 389 p->q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, sch->handle);
758cc43c 390 if (p->q == NULL)
1da177e4 391 p->q = &noop_qdisc;
758cc43c 392
c76f2a2c 393 pr_debug("%s: qdisc %p\n", __func__, p->q);
758cc43c
TG
394
395 err = 0;
396errout:
758cc43c 397 return err;
1da177e4
LT
398}
399
1da177e4
LT
400static void dsmark_reset(struct Qdisc *sch)
401{
81da99ed 402 struct dsmark_qdisc_data *p = qdisc_priv(sch);
1da177e4 403
c76f2a2c 404 pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
1da177e4 405 qdisc_reset(p->q);
5ecc98e1 406 sch->qstats.backlog = 0;
1da177e4
LT
407 sch->q.qlen = 0;
408}
409
1da177e4
LT
410static void dsmark_destroy(struct Qdisc *sch)
411{
81da99ed 412 struct dsmark_qdisc_data *p = qdisc_priv(sch);
1da177e4 413
c76f2a2c 414 pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
af0d1141 415
ff31ab56 416 tcf_destroy_chain(&p->filter_list);
1da177e4 417 qdisc_destroy(p->q);
47bbbb30
ED
418 if (p->mv != p->embedded)
419 kfree(p->mv);
1da177e4
LT
420}
421
1da177e4 422static int dsmark_dump_class(struct Qdisc *sch, unsigned long cl,
02f23f09 423 struct sk_buff *skb, struct tcmsg *tcm)
1da177e4 424{
81da99ed 425 struct dsmark_qdisc_data *p = qdisc_priv(sch);
1e90474c 426 struct nlattr *opts = NULL;
1da177e4 427
c76f2a2c 428 pr_debug("%s(sch %p,[qdisc %p],class %ld\n", __func__, sch, p, cl);
02f23f09
TG
429
430 if (!dsmark_valid_index(p, cl))
1da177e4 431 return -EINVAL;
02f23f09 432
cc7ec456 433 tcm->tcm_handle = TC_H_MAKE(TC_H_MAJ(sch->handle), cl - 1);
cdc7f8e3 434 tcm->tcm_info = p->q->handle;
02f23f09 435
1e90474c
PM
436 opts = nla_nest_start(skb, TCA_OPTIONS);
437 if (opts == NULL)
438 goto nla_put_failure;
47bbbb30
ED
439 if (nla_put_u8(skb, TCA_DSMARK_MASK, p->mv[cl - 1].mask) ||
440 nla_put_u8(skb, TCA_DSMARK_VALUE, p->mv[cl - 1].value))
1b34ec43 441 goto nla_put_failure;
02f23f09 442
1e90474c 443 return nla_nest_end(skb, opts);
1da177e4 444
1e90474c 445nla_put_failure:
bc3ed28c
TG
446 nla_nest_cancel(skb, opts);
447 return -EMSGSIZE;
1da177e4
LT
448}
449
450static int dsmark_dump(struct Qdisc *sch, struct sk_buff *skb)
451{
81da99ed 452 struct dsmark_qdisc_data *p = qdisc_priv(sch);
1e90474c 453 struct nlattr *opts = NULL;
1da177e4 454
1e90474c
PM
455 opts = nla_nest_start(skb, TCA_OPTIONS);
456 if (opts == NULL)
457 goto nla_put_failure;
1b34ec43
DM
458 if (nla_put_u16(skb, TCA_DSMARK_INDICES, p->indices))
459 goto nla_put_failure;
02f23f09 460
1b34ec43
DM
461 if (p->default_index != NO_DEFAULT_INDEX &&
462 nla_put_u16(skb, TCA_DSMARK_DEFAULT_INDEX, p->default_index))
463 goto nla_put_failure;
1da177e4 464
1b34ec43
DM
465 if (p->set_tc_index &&
466 nla_put_flag(skb, TCA_DSMARK_SET_TC_INDEX))
467 goto nla_put_failure;
02f23f09 468
1e90474c 469 return nla_nest_end(skb, opts);
1da177e4 470
1e90474c 471nla_put_failure:
bc3ed28c
TG
472 nla_nest_cancel(skb, opts);
473 return -EMSGSIZE;
1da177e4
LT
474}
475
20fea08b 476static const struct Qdisc_class_ops dsmark_class_ops = {
1da177e4
LT
477 .graft = dsmark_graft,
478 .leaf = dsmark_leaf,
479 .get = dsmark_get,
480 .put = dsmark_put,
481 .change = dsmark_change,
482 .delete = dsmark_delete,
483 .walk = dsmark_walk,
484 .tcf_chain = dsmark_find_tcf,
485 .bind_tcf = dsmark_bind_filter,
486 .unbind_tcf = dsmark_put,
487 .dump = dsmark_dump_class,
488};
489
20fea08b 490static struct Qdisc_ops dsmark_qdisc_ops __read_mostly = {
1da177e4
LT
491 .next = NULL,
492 .cl_ops = &dsmark_class_ops,
493 .id = "dsmark",
494 .priv_size = sizeof(struct dsmark_qdisc_data),
495 .enqueue = dsmark_enqueue,
496 .dequeue = dsmark_dequeue,
8e3af978 497 .peek = dsmark_peek,
1da177e4
LT
498 .drop = dsmark_drop,
499 .init = dsmark_init,
500 .reset = dsmark_reset,
501 .destroy = dsmark_destroy,
502 .change = NULL,
503 .dump = dsmark_dump,
504 .owner = THIS_MODULE,
505};
506
507static int __init dsmark_module_init(void)
508{
509 return register_qdisc(&dsmark_qdisc_ops);
510}
af0d1141 511
10297b99 512static void __exit dsmark_module_exit(void)
1da177e4
LT
513{
514 unregister_qdisc(&dsmark_qdisc_ops);
515}
af0d1141 516
1da177e4
LT
517module_init(dsmark_module_init)
518module_exit(dsmark_module_exit)
af0d1141 519
1da177e4 520MODULE_LICENSE("GPL");