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Linux 2.6.25-rc4
[linux-2.6/next.git] / net / sched / sch_dsmark.c
blob0df911fd67b1bddbcfc38c69fc3f7d5ee12799c1
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/types.h>
9 #include <linux/string.h>
10 #include <linux/errno.h>
11 #include <linux/skbuff.h>
12 #include <linux/rtnetlink.h>
13 #include <linux/bitops.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 /*
20 * classid class marking
21 * ------- ----- -------
22 * n/a 0 n/a
23 * x:0 1 use entry [0]
24 * ... ... ...
25 * x:y y>0 y+1 use entry [y]
26 * ... ... ...
27 * x:indices-1 indices use entry [indices-1]
28 * ... ... ...
29 * x:y y+1 use entry [y & (indices-1)]
30 * ... ... ...
31 * 0xffff 0x10000 use entry [indices-1]
32 */
33
34
35 #define NO_DEFAULT_INDEX (1 << 16)
36
37 struct dsmark_qdisc_data {
38 struct Qdisc *q;
39 struct tcf_proto *filter_list;
40 u8 *mask; /* "owns" the array */
41 u8 *value;
42 u16 indices;
43 u32 default_index; /* index range is 0...0xffff */
44 int set_tc_index;
45 };
46
47 static inline int dsmark_valid_index(struct dsmark_qdisc_data *p, u16 index)
48 {
49 return (index <= p->indices && index > 0);
50 }
51
52 /* ------------------------- Class/flow operations ------------------------- */
53
54 static int dsmark_graft(struct Qdisc *sch, unsigned long arg,
55 struct Qdisc *new, struct Qdisc **old)
56 {
57 struct dsmark_qdisc_data *p = qdisc_priv(sch);
58
59 pr_debug("dsmark_graft(sch %p,[qdisc %p],new %p,old %p)\n",
60 sch, p, new, old);
61
62 if (new == NULL) {
63 new = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops,
64 sch->handle);
65 if (new == NULL)
66 new = &noop_qdisc;
67 }
68
69 sch_tree_lock(sch);
70 *old = xchg(&p->q, new);
71 qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
72 qdisc_reset(*old);
73 sch_tree_unlock(sch);
74
75 return 0;
76 }
77
78 static struct Qdisc *dsmark_leaf(struct Qdisc *sch, unsigned long arg)
79 {
80 struct dsmark_qdisc_data *p = qdisc_priv(sch);
81 return p->q;
82 }
83
84 static unsigned long dsmark_get(struct Qdisc *sch, u32 classid)
85 {
86 pr_debug("dsmark_get(sch %p,[qdisc %p],classid %x)\n",
87 sch, qdisc_priv(sch), classid);
88
89 return TC_H_MIN(classid) + 1;
90 }
91
92 static unsigned long dsmark_bind_filter(struct Qdisc *sch,
93 unsigned long parent, u32 classid)
94 {
95 return dsmark_get(sch, classid);
96 }
97
98 static void dsmark_put(struct Qdisc *sch, unsigned long cl)
99 {
100 }
101
102 static const struct nla_policy dsmark_policy[TCA_DSMARK_MAX + 1] = {
103 [TCA_DSMARK_INDICES] = { .type = NLA_U16 },
104 [TCA_DSMARK_DEFAULT_INDEX] = { .type = NLA_U16 },
105 [TCA_DSMARK_SET_TC_INDEX] = { .type = NLA_FLAG },
106 [TCA_DSMARK_MASK] = { .type = NLA_U8 },
107 [TCA_DSMARK_VALUE] = { .type = NLA_U8 },
108 };
109
110 static int dsmark_change(struct Qdisc *sch, u32 classid, u32 parent,
111 struct nlattr **tca, unsigned long *arg)
112 {
113 struct dsmark_qdisc_data *p = qdisc_priv(sch);
114 struct nlattr *opt = tca[TCA_OPTIONS];
115 struct nlattr *tb[TCA_DSMARK_MAX + 1];
116 int err = -EINVAL;
117 u8 mask = 0;
118
119 pr_debug("dsmark_change(sch %p,[qdisc %p],classid %x,parent %x),"
120 "arg 0x%lx\n", sch, p, classid, parent, *arg);
121
122 if (!dsmark_valid_index(p, *arg)) {
123 err = -ENOENT;
124 goto errout;
125 }
126
127 if (!opt)
128 goto errout;
129
130 err = nla_parse_nested(tb, TCA_DSMARK_MAX, opt, dsmark_policy);
131 if (err < 0)
132 goto errout;
133
134 if (tb[TCA_DSMARK_MASK])
135 mask = nla_get_u8(tb[TCA_DSMARK_MASK]);
136
137 if (tb[TCA_DSMARK_VALUE])
138 p->value[*arg-1] = nla_get_u8(tb[TCA_DSMARK_VALUE]);
139
140 if (tb[TCA_DSMARK_MASK])
141 p->mask[*arg-1] = mask;
142
143 err = 0;
144
145 errout:
146 return err;
147 }
148
149 static int dsmark_delete(struct Qdisc *sch, unsigned long arg)
150 {
151 struct dsmark_qdisc_data *p = qdisc_priv(sch);
152
153 if (!dsmark_valid_index(p, arg))
154 return -EINVAL;
155
156 p->mask[arg-1] = 0xff;
157 p->value[arg-1] = 0;
158
159 return 0;
160 }
161
162 static void dsmark_walk(struct Qdisc *sch, struct qdisc_walker *walker)
163 {
164 struct dsmark_qdisc_data *p = qdisc_priv(sch);
165 int i;
166
167 pr_debug("dsmark_walk(sch %p,[qdisc %p],walker %p)\n", sch, p, walker);
168
169 if (walker->stop)
170 return;
171
172 for (i = 0; i < p->indices; i++) {
173 if (p->mask[i] == 0xff && !p->value[i])
174 goto ignore;
175 if (walker->count >= walker->skip) {
176 if (walker->fn(sch, i+1, walker) < 0) {
177 walker->stop = 1;
178 break;
179 }
180 }
181 ignore:
182 walker->count++;
183 }
184 }
185
186 static inline struct tcf_proto **dsmark_find_tcf(struct Qdisc *sch,
187 unsigned long cl)
188 {
189 struct dsmark_qdisc_data *p = qdisc_priv(sch);
190 return &p->filter_list;
191 }
192
193 /* --------------------------- Qdisc operations ---------------------------- */
194
195 static int dsmark_enqueue(struct sk_buff *skb, struct Qdisc *sch)
196 {
197 struct dsmark_qdisc_data *p = qdisc_priv(sch);
198 int err;
199
200 pr_debug("dsmark_enqueue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);
201
202 if (p->set_tc_index) {
203 switch (skb->protocol) {
204 case __constant_htons(ETH_P_IP):
205 if (skb_cow_head(skb, sizeof(struct iphdr)))
206 goto drop;
207
208 skb->tc_index = ipv4_get_dsfield(ip_hdr(skb))
209 & ~INET_ECN_MASK;
210 break;
211
212 case __constant_htons(ETH_P_IPV6):
213 if (skb_cow_head(skb, sizeof(struct ipv6hdr)))
214 goto drop;
215
216 skb->tc_index = ipv6_get_dsfield(ipv6_hdr(skb))
217 & ~INET_ECN_MASK;
218 break;
219 default:
220 skb->tc_index = 0;
221 break;
222 }
223 }
224
225 if (TC_H_MAJ(skb->priority) == sch->handle)
226 skb->tc_index = TC_H_MIN(skb->priority);
227 else {
228 struct tcf_result res;
229 int result = tc_classify(skb, p->filter_list, &res);
230
231 pr_debug("result %d class 0x%04x\n", result, res.classid);
232
233 switch (result) {
234 #ifdef CONFIG_NET_CLS_ACT
235 case TC_ACT_QUEUED:
236 case TC_ACT_STOLEN:
237 kfree_skb(skb);
238 return NET_XMIT_SUCCESS;
239
240 case TC_ACT_SHOT:
241 goto drop;
242 #endif
243 case TC_ACT_OK:
244 skb->tc_index = TC_H_MIN(res.classid);
245 break;
246
247 default:
248 if (p->default_index != NO_DEFAULT_INDEX)
249 skb->tc_index = p->default_index;
250 break;
251 }
252 }
253
254 err = p->q->enqueue(skb, p->q);
255 if (err != NET_XMIT_SUCCESS) {
256 sch->qstats.drops++;
257 return err;
258 }
259
260 sch->bstats.bytes += skb->len;
261 sch->bstats.packets++;
262 sch->q.qlen++;
263
264 return NET_XMIT_SUCCESS;
265
266 drop:
267 kfree_skb(skb);
268 sch->qstats.drops++;
269 return NET_XMIT_BYPASS;
270 }
271
272 static struct sk_buff *dsmark_dequeue(struct Qdisc *sch)
273 {
274 struct dsmark_qdisc_data *p = qdisc_priv(sch);
275 struct sk_buff *skb;
276 u32 index;
277
278 pr_debug("dsmark_dequeue(sch %p,[qdisc %p])\n", sch, p);
279
280 skb = p->q->ops->dequeue(p->q);
281 if (skb == NULL)
282 return NULL;
283
284 sch->q.qlen--;
285
286 index = skb->tc_index & (p->indices - 1);
287 pr_debug("index %d->%d\n", skb->tc_index, index);
288
289 switch (skb->protocol) {
290 case __constant_htons(ETH_P_IP):
291 ipv4_change_dsfield(ip_hdr(skb), p->mask[index],
292 p->value[index]);
293 break;
294 case __constant_htons(ETH_P_IPV6):
295 ipv6_change_dsfield(ipv6_hdr(skb), p->mask[index],
296 p->value[index]);
297 break;
298 default:
299 /*
300 * Only complain if a change was actually attempted.
301 * This way, we can send non-IP traffic through dsmark
302 * and don't need yet another qdisc as a bypass.
303 */
304 if (p->mask[index] != 0xff || p->value[index])
305 printk(KERN_WARNING
306 "dsmark_dequeue: unsupported protocol %d\n",
307 ntohs(skb->protocol));
308 break;
309 }
310
311 return skb;
312 }
313
314 static int dsmark_requeue(struct sk_buff *skb, struct Qdisc *sch)
315 {
316 struct dsmark_qdisc_data *p = qdisc_priv(sch);
317 int err;
318
319 pr_debug("dsmark_requeue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);
320
321 err = p->q->ops->requeue(skb, p->q);
322 if (err != NET_XMIT_SUCCESS) {
323 sch->qstats.drops++;
324 return err;
325 }
326
327 sch->q.qlen++;
328 sch->qstats.requeues++;
329
330 return NET_XMIT_SUCCESS;
331 }
332
333 static unsigned int dsmark_drop(struct Qdisc *sch)
334 {
335 struct dsmark_qdisc_data *p = qdisc_priv(sch);
336 unsigned int len;
337
338 pr_debug("dsmark_reset(sch %p,[qdisc %p])\n", sch, p);
339
340 if (p->q->ops->drop == NULL)
341 return 0;
342
343 len = p->q->ops->drop(p->q);
344 if (len)
345 sch->q.qlen--;
346
347 return len;
348 }
349
350 static int dsmark_init(struct Qdisc *sch, struct nlattr *opt)
351 {
352 struct dsmark_qdisc_data *p = qdisc_priv(sch);
353 struct nlattr *tb[TCA_DSMARK_MAX + 1];
354 int err = -EINVAL;
355 u32 default_index = NO_DEFAULT_INDEX;
356 u16 indices;
357 u8 *mask;
358
359 pr_debug("dsmark_init(sch %p,[qdisc %p],opt %p)\n", sch, p, opt);
360
361 if (!opt)
362 goto errout;
363
364 err = nla_parse_nested(tb, TCA_DSMARK_MAX, opt, dsmark_policy);
365 if (err < 0)
366 goto errout;
367
368 err = -EINVAL;
369 indices = nla_get_u16(tb[TCA_DSMARK_INDICES]);
370
371 if (hweight32(indices) != 1)
372 goto errout;
373
374 if (tb[TCA_DSMARK_DEFAULT_INDEX])
375 default_index = nla_get_u16(tb[TCA_DSMARK_DEFAULT_INDEX]);
376
377 mask = kmalloc(indices * 2, GFP_KERNEL);
378 if (mask == NULL) {
379 err = -ENOMEM;
380 goto errout;
381 }
382
383 p->mask = mask;
384 memset(p->mask, 0xff, indices);
385
386 p->value = p->mask + indices;
387 memset(p->value, 0, indices);
388
389 p->indices = indices;
390 p->default_index = default_index;
391 p->set_tc_index = nla_get_flag(tb[TCA_DSMARK_SET_TC_INDEX]);
392
393 p->q = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops, sch->handle);
394 if (p->q == NULL)
395 p->q = &noop_qdisc;
396
397 pr_debug("dsmark_init: qdisc %p\n", p->q);
398
399 err = 0;
400 errout:
401 return err;
402 }
403
404 static void dsmark_reset(struct Qdisc *sch)
405 {
406 struct dsmark_qdisc_data *p = qdisc_priv(sch);
407
408 pr_debug("dsmark_reset(sch %p,[qdisc %p])\n", sch, p);
409 qdisc_reset(p->q);
410 sch->q.qlen = 0;
411 }
412
413 static void dsmark_destroy(struct Qdisc *sch)
414 {
415 struct dsmark_qdisc_data *p = qdisc_priv(sch);
416
417 pr_debug("dsmark_destroy(sch %p,[qdisc %p])\n", sch, p);
418
419 tcf_destroy_chain(p->filter_list);
420 qdisc_destroy(p->q);
421 kfree(p->mask);
422 }
423
424 static int dsmark_dump_class(struct Qdisc *sch, unsigned long cl,
425 struct sk_buff *skb, struct tcmsg *tcm)
426 {
427 struct dsmark_qdisc_data *p = qdisc_priv(sch);
428 struct nlattr *opts = NULL;
429
430 pr_debug("dsmark_dump_class(sch %p,[qdisc %p],class %ld\n", sch, p, cl);
431
432 if (!dsmark_valid_index(p, cl))
433 return -EINVAL;
434
435 tcm->tcm_handle = TC_H_MAKE(TC_H_MAJ(sch->handle), cl-1);
436 tcm->tcm_info = p->q->handle;
437
438 opts = nla_nest_start(skb, TCA_OPTIONS);
439 if (opts == NULL)
440 goto nla_put_failure;
441 NLA_PUT_U8(skb, TCA_DSMARK_MASK, p->mask[cl-1]);
442 NLA_PUT_U8(skb, TCA_DSMARK_VALUE, p->value[cl-1]);
443
444 return nla_nest_end(skb, opts);
445
446 nla_put_failure:
447 return nla_nest_cancel(skb, opts);
448 }
449
450 static int dsmark_dump(struct Qdisc *sch, struct sk_buff *skb)
451 {
452 struct dsmark_qdisc_data *p = qdisc_priv(sch);
453 struct nlattr *opts = NULL;
454
455 opts = nla_nest_start(skb, TCA_OPTIONS);
456 if (opts == NULL)
457 goto nla_put_failure;
458 NLA_PUT_U16(skb, TCA_DSMARK_INDICES, p->indices);
459
460 if (p->default_index != NO_DEFAULT_INDEX)
461 NLA_PUT_U16(skb, TCA_DSMARK_DEFAULT_INDEX, p->default_index);
462
463 if (p->set_tc_index)
464 NLA_PUT_FLAG(skb, TCA_DSMARK_SET_TC_INDEX);
465
466 return nla_nest_end(skb, opts);
467
468 nla_put_failure:
469 return nla_nest_cancel(skb, opts);
470 }
471
472 static const struct Qdisc_class_ops dsmark_class_ops = {
473 .graft = dsmark_graft,
474 .leaf = dsmark_leaf,
475 .get = dsmark_get,
476 .put = dsmark_put,
477 .change = dsmark_change,
478 .delete = dsmark_delete,
479 .walk = dsmark_walk,
480 .tcf_chain = dsmark_find_tcf,
481 .bind_tcf = dsmark_bind_filter,
482 .unbind_tcf = dsmark_put,
483 .dump = dsmark_dump_class,
484 };
485
486 static struct Qdisc_ops dsmark_qdisc_ops __read_mostly = {
487 .next = NULL,
488 .cl_ops = &dsmark_class_ops,
489 .id = "dsmark",
490 .priv_size = sizeof(struct dsmark_qdisc_data),
491 .enqueue = dsmark_enqueue,
492 .dequeue = dsmark_dequeue,
493 .requeue = dsmark_requeue,
494 .drop = dsmark_drop,
495 .init = dsmark_init,
496 .reset = dsmark_reset,
497 .destroy = dsmark_destroy,
498 .change = NULL,
499 .dump = dsmark_dump,
500 .owner = THIS_MODULE,
501 };
502
503 static int __init dsmark_module_init(void)
504 {
505 return register_qdisc(&dsmark_qdisc_ops);
506 }
507
508 static void __exit dsmark_module_exit(void)
509 {
510 unregister_qdisc(&dsmark_qdisc_ops);
511 }
512
513 module_init(dsmark_module_init)
514 module_exit(dsmark_module_exit)
515
516 MODULE_LICENSE("GPL");
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