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drm: atmel-hlcdc: Uninitialized return in atmel_hlcdc_create_outputs()
[linux-2.6/btrfs-unstable.git] / net / sched / sch_dsmark.c
blob5334e309f17f0ef4416dddcdc9278c14ecb5585d
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/pkt_cls.h>
17 #include <net/dsfield.h>
18 #include <net/inet_ecn.h>
19 #include <asm/byteorder.h>
20
21 /*
22 * classid class marking
23 * ------- ----- -------
24 * n/a 0 n/a
25 * x:0 1 use entry [0]
26 * ... ... ...
27 * x:y y>0 y+1 use entry [y]
28 * ... ... ...
29 * x:indices-1 indices use entry [indices-1]
30 * ... ... ...
31 * x:y y+1 use entry [y & (indices-1)]
32 * ... ... ...
33 * 0xffff 0x10000 use entry [indices-1]
34 */
35
36
37 #define NO_DEFAULT_INDEX (1 << 16)
38
39 struct mask_value {
40 u8 mask;
41 u8 value;
42 };
43
44 struct dsmark_qdisc_data {
45 struct Qdisc *q;
46 struct tcf_proto __rcu *filter_list;
47 struct mask_value *mv;
48 u16 indices;
49 u8 set_tc_index;
50 u32 default_index; /* index range is 0...0xffff */
51 #define DSMARK_EMBEDDED_SZ 16
52 struct mask_value embedded[DSMARK_EMBEDDED_SZ];
53 };
54
55 static inline int dsmark_valid_index(struct dsmark_qdisc_data *p, u16 index)
56 {
57 return index <= p->indices && index > 0;
58 }
59
60 /* ------------------------- Class/flow operations ------------------------- */
61
62 static int dsmark_graft(struct Qdisc *sch, unsigned long arg,
63 struct Qdisc *new, struct Qdisc **old)
64 {
65 struct dsmark_qdisc_data *p = qdisc_priv(sch);
66
67 pr_debug("%s(sch %p,[qdisc %p],new %p,old %p)\n",
68 __func__, sch, p, new, old);
69
70 if (new == NULL) {
71 new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
72 sch->handle);
73 if (new == NULL)
74 new = &noop_qdisc;
75 }
76
77 *old = qdisc_replace(sch, new, &p->q);
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("%s(sch %p,[qdisc %p],classid %x)\n",
90 __func__, 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
121 pr_debug("%s(sch %p,[qdisc %p],classid %x,parent %x), arg 0x%lx\n",
122 __func__, sch, p, classid, parent, *arg);
123
124 if (!dsmark_valid_index(p, *arg)) {
125 err = -ENOENT;
126 goto errout;
127 }
128
129 if (!opt)
130 goto errout;
131
132 err = nla_parse_nested(tb, TCA_DSMARK_MAX, opt, dsmark_policy);
133 if (err < 0)
134 goto errout;
135
136 if (tb[TCA_DSMARK_VALUE])
137 p->mv[*arg - 1].value = nla_get_u8(tb[TCA_DSMARK_VALUE]);
138
139 if (tb[TCA_DSMARK_MASK])
140 p->mv[*arg - 1].mask = nla_get_u8(tb[TCA_DSMARK_MASK]);
141
142 err = 0;
143
144 errout:
145 return err;
146 }
147
148 static int dsmark_delete(struct Qdisc *sch, unsigned long arg)
149 {
150 struct dsmark_qdisc_data *p = qdisc_priv(sch);
151
152 if (!dsmark_valid_index(p, arg))
153 return -EINVAL;
154
155 p->mv[arg - 1].mask = 0xff;
156 p->mv[arg - 1].value = 0;
157
158 return 0;
159 }
160
161 static void dsmark_walk(struct Qdisc *sch, struct qdisc_walker *walker)
162 {
163 struct dsmark_qdisc_data *p = qdisc_priv(sch);
164 int i;
165
166 pr_debug("%s(sch %p,[qdisc %p],walker %p)\n",
167 __func__, sch, p, walker);
168
169 if (walker->stop)
170 return;
171
172 for (i = 0; i < p->indices; i++) {
173 if (p->mv[i].mask == 0xff && !p->mv[i].value)
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 __rcu **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 struct sk_buff **to_free)
197 {
198 struct dsmark_qdisc_data *p = qdisc_priv(sch);
199 int err;
200
201 pr_debug("%s(skb %p,sch %p,[qdisc %p])\n", __func__, skb, sch, p);
202
203 if (p->set_tc_index) {
204 int wlen = skb_network_offset(skb);
205
206 switch (tc_skb_protocol(skb)) {
207 case htons(ETH_P_IP):
208 wlen += sizeof(struct iphdr);
209 if (!pskb_may_pull(skb, wlen) ||
210 skb_try_make_writable(skb, wlen))
211 goto drop;
212
213 skb->tc_index = ipv4_get_dsfield(ip_hdr(skb))
214 & ~INET_ECN_MASK;
215 break;
216
217 case htons(ETH_P_IPV6):
218 wlen += sizeof(struct ipv6hdr);
219 if (!pskb_may_pull(skb, wlen) ||
220 skb_try_make_writable(skb, wlen))
221 goto drop;
222
223 skb->tc_index = ipv6_get_dsfield(ipv6_hdr(skb))
224 & ~INET_ECN_MASK;
225 break;
226 default:
227 skb->tc_index = 0;
228 break;
229 }
230 }
231
232 if (TC_H_MAJ(skb->priority) == sch->handle)
233 skb->tc_index = TC_H_MIN(skb->priority);
234 else {
235 struct tcf_result res;
236 struct tcf_proto *fl = rcu_dereference_bh(p->filter_list);
237 int result = tc_classify(skb, fl, &res, false);
238
239 pr_debug("result %d class 0x%04x\n", result, res.classid);
240
241 switch (result) {
242 #ifdef CONFIG_NET_CLS_ACT
243 case TC_ACT_QUEUED:
244 case TC_ACT_STOLEN:
245 __qdisc_drop(skb, to_free);
246 return NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
247
248 case TC_ACT_SHOT:
249 goto drop;
250 #endif
251 case TC_ACT_OK:
252 skb->tc_index = TC_H_MIN(res.classid);
253 break;
254
255 default:
256 if (p->default_index != NO_DEFAULT_INDEX)
257 skb->tc_index = p->default_index;
258 break;
259 }
260 }
261
262 err = qdisc_enqueue(skb, p->q, to_free);
263 if (err != NET_XMIT_SUCCESS) {
264 if (net_xmit_drop_count(err))
265 qdisc_qstats_drop(sch);
266 return err;
267 }
268
269 qdisc_qstats_backlog_inc(sch, skb);
270 sch->q.qlen++;
271
272 return NET_XMIT_SUCCESS;
273
274 drop:
275 qdisc_drop(skb, sch, to_free);
276 return NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
277 }
278
279 static struct sk_buff *dsmark_dequeue(struct Qdisc *sch)
280 {
281 struct dsmark_qdisc_data *p = qdisc_priv(sch);
282 struct sk_buff *skb;
283 u32 index;
284
285 pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
286
287 skb = qdisc_dequeue_peeked(p->q);
288 if (skb == NULL)
289 return NULL;
290
291 qdisc_bstats_update(sch, skb);
292 qdisc_qstats_backlog_dec(sch, skb);
293 sch->q.qlen--;
294
295 index = skb->tc_index & (p->indices - 1);
296 pr_debug("index %d->%d\n", skb->tc_index, index);
297
298 switch (tc_skb_protocol(skb)) {
299 case htons(ETH_P_IP):
300 ipv4_change_dsfield(ip_hdr(skb), p->mv[index].mask,
301 p->mv[index].value);
302 break;
303 case htons(ETH_P_IPV6):
304 ipv6_change_dsfield(ipv6_hdr(skb), p->mv[index].mask,
305 p->mv[index].value);
306 break;
307 default:
308 /*
309 * Only complain if a change was actually attempted.
310 * This way, we can send non-IP traffic through dsmark
311 * and don't need yet another qdisc as a bypass.
312 */
313 if (p->mv[index].mask != 0xff || p->mv[index].value)
314 pr_warn("%s: unsupported protocol %d\n",
315 __func__, ntohs(tc_skb_protocol(skb)));
316 break;
317 }
318
319 return skb;
320 }
321
322 static struct sk_buff *dsmark_peek(struct Qdisc *sch)
323 {
324 struct dsmark_qdisc_data *p = qdisc_priv(sch);
325
326 pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
327
328 return p->q->ops->peek(p->q);
329 }
330
331 static int dsmark_init(struct Qdisc *sch, struct nlattr *opt)
332 {
333 struct dsmark_qdisc_data *p = qdisc_priv(sch);
334 struct nlattr *tb[TCA_DSMARK_MAX + 1];
335 int err = -EINVAL;
336 u32 default_index = NO_DEFAULT_INDEX;
337 u16 indices;
338 int i;
339
340 pr_debug("%s(sch %p,[qdisc %p],opt %p)\n", __func__, sch, p, opt);
341
342 if (!opt)
343 goto errout;
344
345 err = nla_parse_nested(tb, TCA_DSMARK_MAX, opt, dsmark_policy);
346 if (err < 0)
347 goto errout;
348
349 err = -EINVAL;
350 indices = nla_get_u16(tb[TCA_DSMARK_INDICES]);
351
352 if (hweight32(indices) != 1)
353 goto errout;
354
355 if (tb[TCA_DSMARK_DEFAULT_INDEX])
356 default_index = nla_get_u16(tb[TCA_DSMARK_DEFAULT_INDEX]);
357
358 if (indices <= DSMARK_EMBEDDED_SZ)
359 p->mv = p->embedded;
360 else
361 p->mv = kmalloc_array(indices, sizeof(*p->mv), GFP_KERNEL);
362 if (!p->mv) {
363 err = -ENOMEM;
364 goto errout;
365 }
366 for (i = 0; i < indices; i++) {
367 p->mv[i].mask = 0xff;
368 p->mv[i].value = 0;
369 }
370 p->indices = indices;
371 p->default_index = default_index;
372 p->set_tc_index = nla_get_flag(tb[TCA_DSMARK_SET_TC_INDEX]);
373
374 p->q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, sch->handle);
375 if (p->q == NULL)
376 p->q = &noop_qdisc;
377
378 pr_debug("%s: qdisc %p\n", __func__, p->q);
379
380 err = 0;
381 errout:
382 return err;
383 }
384
385 static void dsmark_reset(struct Qdisc *sch)
386 {
387 struct dsmark_qdisc_data *p = qdisc_priv(sch);
388
389 pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
390 qdisc_reset(p->q);
391 sch->qstats.backlog = 0;
392 sch->q.qlen = 0;
393 }
394
395 static void dsmark_destroy(struct Qdisc *sch)
396 {
397 struct dsmark_qdisc_data *p = qdisc_priv(sch);
398
399 pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
400
401 tcf_destroy_chain(&p->filter_list);
402 qdisc_destroy(p->q);
403 if (p->mv != p->embedded)
404 kfree(p->mv);
405 }
406
407 static int dsmark_dump_class(struct Qdisc *sch, unsigned long cl,
408 struct sk_buff *skb, struct tcmsg *tcm)
409 {
410 struct dsmark_qdisc_data *p = qdisc_priv(sch);
411 struct nlattr *opts = NULL;
412
413 pr_debug("%s(sch %p,[qdisc %p],class %ld\n", __func__, sch, p, cl);
414
415 if (!dsmark_valid_index(p, cl))
416 return -EINVAL;
417
418 tcm->tcm_handle = TC_H_MAKE(TC_H_MAJ(sch->handle), cl - 1);
419 tcm->tcm_info = p->q->handle;
420
421 opts = nla_nest_start(skb, TCA_OPTIONS);
422 if (opts == NULL)
423 goto nla_put_failure;
424 if (nla_put_u8(skb, TCA_DSMARK_MASK, p->mv[cl - 1].mask) ||
425 nla_put_u8(skb, TCA_DSMARK_VALUE, p->mv[cl - 1].value))
426 goto nla_put_failure;
427
428 return nla_nest_end(skb, opts);
429
430 nla_put_failure:
431 nla_nest_cancel(skb, opts);
432 return -EMSGSIZE;
433 }
434
435 static int dsmark_dump(struct Qdisc *sch, struct sk_buff *skb)
436 {
437 struct dsmark_qdisc_data *p = qdisc_priv(sch);
438 struct nlattr *opts = NULL;
439
440 opts = nla_nest_start(skb, TCA_OPTIONS);
441 if (opts == NULL)
442 goto nla_put_failure;
443 if (nla_put_u16(skb, TCA_DSMARK_INDICES, p->indices))
444 goto nla_put_failure;
445
446 if (p->default_index != NO_DEFAULT_INDEX &&
447 nla_put_u16(skb, TCA_DSMARK_DEFAULT_INDEX, p->default_index))
448 goto nla_put_failure;
449
450 if (p->set_tc_index &&
451 nla_put_flag(skb, TCA_DSMARK_SET_TC_INDEX))
452 goto nla_put_failure;
453
454 return nla_nest_end(skb, opts);
455
456 nla_put_failure:
457 nla_nest_cancel(skb, opts);
458 return -EMSGSIZE;
459 }
460
461 static const struct Qdisc_class_ops dsmark_class_ops = {
462 .graft = dsmark_graft,
463 .leaf = dsmark_leaf,
464 .get = dsmark_get,
465 .put = dsmark_put,
466 .change = dsmark_change,
467 .delete = dsmark_delete,
468 .walk = dsmark_walk,
469 .tcf_chain = dsmark_find_tcf,
470 .bind_tcf = dsmark_bind_filter,
471 .unbind_tcf = dsmark_put,
472 .dump = dsmark_dump_class,
473 };
474
475 static struct Qdisc_ops dsmark_qdisc_ops __read_mostly = {
476 .next = NULL,
477 .cl_ops = &dsmark_class_ops,
478 .id = "dsmark",
479 .priv_size = sizeof(struct dsmark_qdisc_data),
480 .enqueue = dsmark_enqueue,
481 .dequeue = dsmark_dequeue,
482 .peek = dsmark_peek,
483 .init = dsmark_init,
484 .reset = dsmark_reset,
485 .destroy = dsmark_destroy,
486 .change = NULL,
487 .dump = dsmark_dump,
488 .owner = THIS_MODULE,
489 };
490
491 static int __init dsmark_module_init(void)
492 {
493 return register_qdisc(&dsmark_qdisc_ops);
494 }
495
496 static void __exit dsmark_module_exit(void)
497 {
498 unregister_qdisc(&dsmark_qdisc_ops);
499 }
500
501 module_init(dsmark_module_init)
502 module_exit(dsmark_module_exit)
503
504 MODULE_LICENSE("GPL");
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