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writeback: split writeback_inodes_wb
[linux-2.6/next.git] / net / sched / sch_dsmark.c
blob63d41f86679c0653951090c81f189665c5deaa00
1 /* net/sched/sch_dsmark.c - Differentiated Services field marker */
2
3 /* Written 1998-2000 by Werner Almesberger, EPFL ICA */
4
5
6 #include <linux/module.h>
7 #include <linux/init.h>
8 #include <linux/slab.h>
9 #include <linux/types.h>
10 #include <linux/string.h>
11 #include <linux/errno.h>
12 #include <linux/skbuff.h>
13 #include <linux/rtnetlink.h>
14 #include <linux/bitops.h>
15 #include <net/pkt_sched.h>
16 #include <net/dsfield.h>
17 #include <net/inet_ecn.h>
18 #include <asm/byteorder.h>
19
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
38 struct dsmark_qdisc_data {
39 struct Qdisc *q;
40 struct tcf_proto *filter_list;
41 u8 *mask; /* "owns" the array */
42 u8 *value;
43 u16 indices;
44 u32 default_index; /* index range is 0...0xffff */
45 int set_tc_index;
46 };
47
48 static inline int dsmark_valid_index(struct dsmark_qdisc_data *p, u16 index)
49 {
50 return (index <= p->indices && index > 0);
51 }
52
53 /* ------------------------- Class/flow operations ------------------------- */
54
55 static int dsmark_graft(struct Qdisc *sch, unsigned long arg,
56 struct Qdisc *new, struct Qdisc **old)
57 {
58 struct dsmark_qdisc_data *p = qdisc_priv(sch);
59
60 pr_debug("dsmark_graft(sch %p,[qdisc %p],new %p,old %p)\n",
61 sch, p, new, old);
62
63 if (new == NULL) {
64 new = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue,
65 &pfifo_qdisc_ops,
66 sch->handle);
67 if (new == NULL)
68 new = &noop_qdisc;
69 }
70
71 sch_tree_lock(sch);
72 *old = p->q;
73 p->q = new;
74 qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
75 qdisc_reset(*old);
76 sch_tree_unlock(sch);
77
78 return 0;
79 }
80
81 static struct Qdisc *dsmark_leaf(struct Qdisc *sch, unsigned long arg)
82 {
83 struct dsmark_qdisc_data *p = qdisc_priv(sch);
84 return p->q;
85 }
86
87 static unsigned long dsmark_get(struct Qdisc *sch, u32 classid)
88 {
89 pr_debug("dsmark_get(sch %p,[qdisc %p],classid %x)\n",
90 sch, qdisc_priv(sch), classid);
91
92 return TC_H_MIN(classid) + 1;
93 }
94
95 static unsigned long dsmark_bind_filter(struct Qdisc *sch,
96 unsigned long parent, u32 classid)
97 {
98 return dsmark_get(sch, classid);
99 }
100
101 static void dsmark_put(struct Qdisc *sch, unsigned long cl)
102 {
103 }
104
105 static const struct nla_policy dsmark_policy[TCA_DSMARK_MAX + 1] = {
106 [TCA_DSMARK_INDICES] = { .type = NLA_U16 },
107 [TCA_DSMARK_DEFAULT_INDEX] = { .type = NLA_U16 },
108 [TCA_DSMARK_SET_TC_INDEX] = { .type = NLA_FLAG },
109 [TCA_DSMARK_MASK] = { .type = NLA_U8 },
110 [TCA_DSMARK_VALUE] = { .type = NLA_U8 },
111 };
112
113 static int dsmark_change(struct Qdisc *sch, u32 classid, u32 parent,
114 struct nlattr **tca, unsigned long *arg)
115 {
116 struct dsmark_qdisc_data *p = qdisc_priv(sch);
117 struct nlattr *opt = tca[TCA_OPTIONS];
118 struct nlattr *tb[TCA_DSMARK_MAX + 1];
119 int err = -EINVAL;
120 u8 mask = 0;
121
122 pr_debug("dsmark_change(sch %p,[qdisc %p],classid %x,parent %x),"
123 "arg 0x%lx\n", sch, p, classid, parent, *arg);
124
125 if (!dsmark_valid_index(p, *arg)) {
126 err = -ENOENT;
127 goto errout;
128 }
129
130 if (!opt)
131 goto errout;
132
133 err = nla_parse_nested(tb, TCA_DSMARK_MAX, opt, dsmark_policy);
134 if (err < 0)
135 goto errout;
136
137 if (tb[TCA_DSMARK_MASK])
138 mask = nla_get_u8(tb[TCA_DSMARK_MASK]);
139
140 if (tb[TCA_DSMARK_VALUE])
141 p->value[*arg-1] = nla_get_u8(tb[TCA_DSMARK_VALUE]);
142
143 if (tb[TCA_DSMARK_MASK])
144 p->mask[*arg-1] = mask;
145
146 err = 0;
147
148 errout:
149 return err;
150 }
151
152 static int dsmark_delete(struct Qdisc *sch, unsigned long arg)
153 {
154 struct dsmark_qdisc_data *p = qdisc_priv(sch);
155
156 if (!dsmark_valid_index(p, arg))
157 return -EINVAL;
158
159 p->mask[arg-1] = 0xff;
160 p->value[arg-1] = 0;
161
162 return 0;
163 }
164
165 static void dsmark_walk(struct Qdisc *sch, struct qdisc_walker *walker)
166 {
167 struct dsmark_qdisc_data *p = qdisc_priv(sch);
168 int i;
169
170 pr_debug("dsmark_walk(sch %p,[qdisc %p],walker %p)\n", sch, p, walker);
171
172 if (walker->stop)
173 return;
174
175 for (i = 0; i < p->indices; i++) {
176 if (p->mask[i] == 0xff && !p->value[i])
177 goto ignore;
178 if (walker->count >= walker->skip) {
179 if (walker->fn(sch, i+1, walker) < 0) {
180 walker->stop = 1;
181 break;
182 }
183 }
184 ignore:
185 walker->count++;
186 }
187 }
188
189 static inline struct tcf_proto **dsmark_find_tcf(struct Qdisc *sch,
190 unsigned long cl)
191 {
192 struct dsmark_qdisc_data *p = qdisc_priv(sch);
193 return &p->filter_list;
194 }
195
196 /* --------------------------- Qdisc operations ---------------------------- */
197
198 static int dsmark_enqueue(struct sk_buff *skb, struct Qdisc *sch)
199 {
200 struct dsmark_qdisc_data *p = qdisc_priv(sch);
201 int err;
202
203 pr_debug("dsmark_enqueue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);
204
205 if (p->set_tc_index) {
206 switch (skb->protocol) {
207 case htons(ETH_P_IP):
208 if (skb_cow_head(skb, sizeof(struct iphdr)))
209 goto drop;
210
211 skb->tc_index = ipv4_get_dsfield(ip_hdr(skb))
212 & ~INET_ECN_MASK;
213 break;
214
215 case htons(ETH_P_IPV6):
216 if (skb_cow_head(skb, sizeof(struct ipv6hdr)))
217 goto drop;
218
219 skb->tc_index = ipv6_get_dsfield(ipv6_hdr(skb))
220 & ~INET_ECN_MASK;
221 break;
222 default:
223 skb->tc_index = 0;
224 break;
225 }
226 }
227
228 if (TC_H_MAJ(skb->priority) == sch->handle)
229 skb->tc_index = TC_H_MIN(skb->priority);
230 else {
231 struct tcf_result res;
232 int result = tc_classify(skb, p->filter_list, &res);
233
234 pr_debug("result %d class 0x%04x\n", result, res.classid);
235
236 switch (result) {
237 #ifdef CONFIG_NET_CLS_ACT
238 case TC_ACT_QUEUED:
239 case TC_ACT_STOLEN:
240 kfree_skb(skb);
241 return NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
242
243 case TC_ACT_SHOT:
244 goto drop;
245 #endif
246 case TC_ACT_OK:
247 skb->tc_index = TC_H_MIN(res.classid);
248 break;
249
250 default:
251 if (p->default_index != NO_DEFAULT_INDEX)
252 skb->tc_index = p->default_index;
253 break;
254 }
255 }
256
257 err = qdisc_enqueue(skb, p->q);
258 if (err != NET_XMIT_SUCCESS) {
259 if (net_xmit_drop_count(err))
260 sch->qstats.drops++;
261 return err;
262 }
263
264 sch->bstats.bytes += qdisc_pkt_len(skb);
265 sch->bstats.packets++;
266 sch->q.qlen++;
267
268 return NET_XMIT_SUCCESS;
269
270 drop:
271 kfree_skb(skb);
272 sch->qstats.drops++;
273 return NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
274 }
275
276 static struct sk_buff *dsmark_dequeue(struct Qdisc *sch)
277 {
278 struct dsmark_qdisc_data *p = qdisc_priv(sch);
279 struct sk_buff *skb;
280 u32 index;
281
282 pr_debug("dsmark_dequeue(sch %p,[qdisc %p])\n", sch, p);
283
284 skb = p->q->ops->dequeue(p->q);
285 if (skb == NULL)
286 return NULL;
287
288 sch->q.qlen--;
289
290 index = skb->tc_index & (p->indices - 1);
291 pr_debug("index %d->%d\n", skb->tc_index, index);
292
293 switch (skb->protocol) {
294 case htons(ETH_P_IP):
295 ipv4_change_dsfield(ip_hdr(skb), p->mask[index],
296 p->value[index]);
297 break;
298 case htons(ETH_P_IPV6):
299 ipv6_change_dsfield(ipv6_hdr(skb), p->mask[index],
300 p->value[index]);
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
310 "dsmark_dequeue: unsupported protocol %d\n",
311 ntohs(skb->protocol));
312 break;
313 }
314
315 return skb;
316 }
317
318 static struct sk_buff *dsmark_peek(struct Qdisc *sch)
319 {
320 struct dsmark_qdisc_data *p = qdisc_priv(sch);
321
322 pr_debug("dsmark_peek(sch %p,[qdisc %p])\n", sch, p);
323
324 return p->q->ops->peek(p->q);
325 }
326
327 static unsigned int dsmark_drop(struct Qdisc *sch)
328 {
329 struct dsmark_qdisc_data *p = qdisc_priv(sch);
330 unsigned int len;
331
332 pr_debug("dsmark_reset(sch %p,[qdisc %p])\n", sch, p);
333
334 if (p->q->ops->drop == NULL)
335 return 0;
336
337 len = p->q->ops->drop(p->q);
338 if (len)
339 sch->q.qlen--;
340
341 return len;
342 }
343
344 static int dsmark_init(struct Qdisc *sch, struct nlattr *opt)
345 {
346 struct dsmark_qdisc_data *p = qdisc_priv(sch);
347 struct nlattr *tb[TCA_DSMARK_MAX + 1];
348 int err = -EINVAL;
349 u32 default_index = NO_DEFAULT_INDEX;
350 u16 indices;
351 u8 *mask;
352
353 pr_debug("dsmark_init(sch %p,[qdisc %p],opt %p)\n", sch, p, opt);
354
355 if (!opt)
356 goto errout;
357
358 err = nla_parse_nested(tb, TCA_DSMARK_MAX, opt, dsmark_policy);
359 if (err < 0)
360 goto errout;
361
362 err = -EINVAL;
363 indices = nla_get_u16(tb[TCA_DSMARK_INDICES]);
364
365 if (hweight32(indices) != 1)
366 goto errout;
367
368 if (tb[TCA_DSMARK_DEFAULT_INDEX])
369 default_index = nla_get_u16(tb[TCA_DSMARK_DEFAULT_INDEX]);
370
371 mask = kmalloc(indices * 2, GFP_KERNEL);
372 if (mask == NULL) {
373 err = -ENOMEM;
374 goto errout;
375 }
376
377 p->mask = mask;
378 memset(p->mask, 0xff, indices);
379
380 p->value = p->mask + indices;
381 memset(p->value, 0, indices);
382
383 p->indices = indices;
384 p->default_index = default_index;
385 p->set_tc_index = nla_get_flag(tb[TCA_DSMARK_SET_TC_INDEX]);
386
387 p->q = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue,
388 &pfifo_qdisc_ops, sch->handle);
389 if (p->q == NULL)
390 p->q = &noop_qdisc;
391
392 pr_debug("dsmark_init: qdisc %p\n", p->q);
393
394 err = 0;
395 errout:
396 return err;
397 }
398
399 static void dsmark_reset(struct Qdisc *sch)
400 {
401 struct dsmark_qdisc_data *p = qdisc_priv(sch);
402
403 pr_debug("dsmark_reset(sch %p,[qdisc %p])\n", sch, p);
404 qdisc_reset(p->q);
405 sch->q.qlen = 0;
406 }
407
408 static void dsmark_destroy(struct Qdisc *sch)
409 {
410 struct dsmark_qdisc_data *p = qdisc_priv(sch);
411
412 pr_debug("dsmark_destroy(sch %p,[qdisc %p])\n", sch, p);
413
414 tcf_destroy_chain(&p->filter_list);
415 qdisc_destroy(p->q);
416 kfree(p->mask);
417 }
418
419 static int dsmark_dump_class(struct Qdisc *sch, unsigned long cl,
420 struct sk_buff *skb, struct tcmsg *tcm)
421 {
422 struct dsmark_qdisc_data *p = qdisc_priv(sch);
423 struct nlattr *opts = NULL;
424
425 pr_debug("dsmark_dump_class(sch %p,[qdisc %p],class %ld\n", sch, p, cl);
426
427 if (!dsmark_valid_index(p, cl))
428 return -EINVAL;
429
430 tcm->tcm_handle = TC_H_MAKE(TC_H_MAJ(sch->handle), cl-1);
431 tcm->tcm_info = p->q->handle;
432
433 opts = nla_nest_start(skb, TCA_OPTIONS);
434 if (opts == NULL)
435 goto nla_put_failure;
436 NLA_PUT_U8(skb, TCA_DSMARK_MASK, p->mask[cl-1]);
437 NLA_PUT_U8(skb, TCA_DSMARK_VALUE, p->value[cl-1]);
438
439 return nla_nest_end(skb, opts);
440
441 nla_put_failure:
442 nla_nest_cancel(skb, opts);
443 return -EMSGSIZE;
444 }
445
446 static int dsmark_dump(struct Qdisc *sch, struct sk_buff *skb)
447 {
448 struct dsmark_qdisc_data *p = qdisc_priv(sch);
449 struct nlattr *opts = NULL;
450
451 opts = nla_nest_start(skb, TCA_OPTIONS);
452 if (opts == NULL)
453 goto nla_put_failure;
454 NLA_PUT_U16(skb, TCA_DSMARK_INDICES, p->indices);
455
456 if (p->default_index != NO_DEFAULT_INDEX)
457 NLA_PUT_U16(skb, TCA_DSMARK_DEFAULT_INDEX, p->default_index);
458
459 if (p->set_tc_index)
460 NLA_PUT_FLAG(skb, TCA_DSMARK_SET_TC_INDEX);
461
462 return nla_nest_end(skb, opts);
463
464 nla_put_failure:
465 nla_nest_cancel(skb, opts);
466 return -EMSGSIZE;
467 }
468
469 static const struct Qdisc_class_ops dsmark_class_ops = {
470 .graft = dsmark_graft,
471 .leaf = dsmark_leaf,
472 .get = dsmark_get,
473 .put = dsmark_put,
474 .change = dsmark_change,
475 .delete = dsmark_delete,
476 .walk = dsmark_walk,
477 .tcf_chain = dsmark_find_tcf,
478 .bind_tcf = dsmark_bind_filter,
479 .unbind_tcf = dsmark_put,
480 .dump = dsmark_dump_class,
481 };
482
483 static struct Qdisc_ops dsmark_qdisc_ops __read_mostly = {
484 .next = NULL,
485 .cl_ops = &dsmark_class_ops,
486 .id = "dsmark",
487 .priv_size = sizeof(struct dsmark_qdisc_data),
488 .enqueue = dsmark_enqueue,
489 .dequeue = dsmark_dequeue,
490 .peek = dsmark_peek,
491 .drop = dsmark_drop,
492 .init = dsmark_init,
493 .reset = dsmark_reset,
494 .destroy = dsmark_destroy,
495 .change = NULL,
496 .dump = dsmark_dump,
497 .owner = THIS_MODULE,
498 };
499
500 static int __init dsmark_module_init(void)
501 {
502 return register_qdisc(&dsmark_qdisc_ops);
503 }
504
505 static void __exit dsmark_module_exit(void)
506 {
507 unregister_qdisc(&dsmark_qdisc_ops);
508 }
509
510 module_init(dsmark_module_init)
511 module_exit(dsmark_module_exit)
512
513 MODULE_LICENSE("GPL");
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