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[NET_SCHED]: Propagate nla_parse return value
[linux-2.6/linux-loongson.git] / net / sched / sch_dsmark.c
blobf1d0a08aca75fe53bad0ffa14cb5c2eb628fa252
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 int dsmark_change(struct Qdisc *sch, u32 classid, u32 parent,
103 struct nlattr **tca, unsigned long *arg)
104 {
105 struct dsmark_qdisc_data *p = qdisc_priv(sch);
106 struct nlattr *opt = tca[TCA_OPTIONS];
107 struct nlattr *tb[TCA_DSMARK_MAX + 1];
108 int err = -EINVAL;
109 u8 mask = 0;
110
111 pr_debug("dsmark_change(sch %p,[qdisc %p],classid %x,parent %x),"
112 "arg 0x%lx\n", sch, p, classid, parent, *arg);
113
114 if (!dsmark_valid_index(p, *arg)) {
115 err = -ENOENT;
116 goto errout;
117 }
118
119 if (!opt)
120 goto errout;
121
122 err = nla_parse_nested(tb, TCA_DSMARK_MAX, opt, NULL);
123 if (err < 0)
124 return err;
125
126 err = -EINVAL;
127 if (tb[TCA_DSMARK_MASK]) {
128 if (nla_len(tb[TCA_DSMARK_MASK]) < sizeof(u8))
129 goto errout;
130 mask = nla_get_u8(tb[TCA_DSMARK_MASK]);
131 }
132 if (tb[TCA_DSMARK_VALUE]) {
133 if (nla_len(tb[TCA_DSMARK_VALUE]) < sizeof(u8))
134 goto errout;
135 p->value[*arg-1] = nla_get_u8(tb[TCA_DSMARK_VALUE]);
136 }
137
138 if (tb[TCA_DSMARK_MASK])
139 p->mask[*arg-1] = mask;
140
141 err = 0;
142
143 errout:
144 return err;
145 }
146
147 static int dsmark_delete(struct Qdisc *sch, unsigned long arg)
148 {
149 struct dsmark_qdisc_data *p = qdisc_priv(sch);
150
151 if (!dsmark_valid_index(p, arg))
152 return -EINVAL;
153
154 p->mask[arg-1] = 0xff;
155 p->value[arg-1] = 0;
156
157 return 0;
158 }
159
160 static void dsmark_walk(struct Qdisc *sch, struct qdisc_walker *walker)
161 {
162 struct dsmark_qdisc_data *p = qdisc_priv(sch);
163 int i;
164
165 pr_debug("dsmark_walk(sch %p,[qdisc %p],walker %p)\n", sch, p, walker);
166
167 if (walker->stop)
168 return;
169
170 for (i = 0; i < p->indices; i++) {
171 if (p->mask[i] == 0xff && !p->value[i])
172 goto ignore;
173 if (walker->count >= walker->skip) {
174 if (walker->fn(sch, i+1, walker) < 0) {
175 walker->stop = 1;
176 break;
177 }
178 }
179 ignore:
180 walker->count++;
181 }
182 }
183
184 static inline struct tcf_proto **dsmark_find_tcf(struct Qdisc *sch,
185 unsigned long cl)
186 {
187 struct dsmark_qdisc_data *p = qdisc_priv(sch);
188 return &p->filter_list;
189 }
190
191 /* --------------------------- Qdisc operations ---------------------------- */
192
193 static int dsmark_enqueue(struct sk_buff *skb, struct Qdisc *sch)
194 {
195 struct dsmark_qdisc_data *p = qdisc_priv(sch);
196 int err;
197
198 pr_debug("dsmark_enqueue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);
199
200 if (p->set_tc_index) {
201 switch (skb->protocol) {
202 case __constant_htons(ETH_P_IP):
203 if (skb_cow_head(skb, sizeof(struct iphdr)))
204 goto drop;
205
206 skb->tc_index = ipv4_get_dsfield(ip_hdr(skb))
207 & ~INET_ECN_MASK;
208 break;
209
210 case __constant_htons(ETH_P_IPV6):
211 if (skb_cow_head(skb, sizeof(struct ipv6hdr)))
212 goto drop;
213
214 skb->tc_index = ipv6_get_dsfield(ipv6_hdr(skb))
215 & ~INET_ECN_MASK;
216 break;
217 default:
218 skb->tc_index = 0;
219 break;
220 }
221 }
222
223 if (TC_H_MAJ(skb->priority) == sch->handle)
224 skb->tc_index = TC_H_MIN(skb->priority);
225 else {
226 struct tcf_result res;
227 int result = tc_classify(skb, p->filter_list, &res);
228
229 pr_debug("result %d class 0x%04x\n", result, res.classid);
230
231 switch (result) {
232 #ifdef CONFIG_NET_CLS_ACT
233 case TC_ACT_QUEUED:
234 case TC_ACT_STOLEN:
235 kfree_skb(skb);
236 return NET_XMIT_SUCCESS;
237
238 case TC_ACT_SHOT:
239 goto drop;
240 #endif
241 case TC_ACT_OK:
242 skb->tc_index = TC_H_MIN(res.classid);
243 break;
244
245 default:
246 if (p->default_index != NO_DEFAULT_INDEX)
247 skb->tc_index = p->default_index;
248 break;
249 }
250 }
251
252 err = p->q->enqueue(skb, p->q);
253 if (err != NET_XMIT_SUCCESS) {
254 sch->qstats.drops++;
255 return err;
256 }
257
258 sch->bstats.bytes += skb->len;
259 sch->bstats.packets++;
260 sch->q.qlen++;
261
262 return NET_XMIT_SUCCESS;
263
264 drop:
265 kfree_skb(skb);
266 sch->qstats.drops++;
267 return NET_XMIT_BYPASS;
268 }
269
270 static struct sk_buff *dsmark_dequeue(struct Qdisc *sch)
271 {
272 struct dsmark_qdisc_data *p = qdisc_priv(sch);
273 struct sk_buff *skb;
274 u32 index;
275
276 pr_debug("dsmark_dequeue(sch %p,[qdisc %p])\n", sch, p);
277
278 skb = p->q->ops->dequeue(p->q);
279 if (skb == NULL)
280 return NULL;
281
282 sch->q.qlen--;
283
284 index = skb->tc_index & (p->indices - 1);
285 pr_debug("index %d->%d\n", skb->tc_index, index);
286
287 switch (skb->protocol) {
288 case __constant_htons(ETH_P_IP):
289 ipv4_change_dsfield(ip_hdr(skb), p->mask[index],
290 p->value[index]);
291 break;
292 case __constant_htons(ETH_P_IPV6):
293 ipv6_change_dsfield(ipv6_hdr(skb), p->mask[index],
294 p->value[index]);
295 break;
296 default:
297 /*
298 * Only complain if a change was actually attempted.
299 * This way, we can send non-IP traffic through dsmark
300 * and don't need yet another qdisc as a bypass.
301 */
302 if (p->mask[index] != 0xff || p->value[index])
303 printk(KERN_WARNING
304 "dsmark_dequeue: unsupported protocol %d\n",
305 ntohs(skb->protocol));
306 break;
307 }
308
309 return skb;
310 }
311
312 static int dsmark_requeue(struct sk_buff *skb, struct Qdisc *sch)
313 {
314 struct dsmark_qdisc_data *p = qdisc_priv(sch);
315 int err;
316
317 pr_debug("dsmark_requeue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);
318
319 err = p->q->ops->requeue(skb, p->q);
320 if (err != NET_XMIT_SUCCESS) {
321 sch->qstats.drops++;
322 return err;
323 }
324
325 sch->q.qlen++;
326 sch->qstats.requeues++;
327
328 return NET_XMIT_SUCCESS;
329 }
330
331 static unsigned int dsmark_drop(struct Qdisc *sch)
332 {
333 struct dsmark_qdisc_data *p = qdisc_priv(sch);
334 unsigned int len;
335
336 pr_debug("dsmark_reset(sch %p,[qdisc %p])\n", sch, p);
337
338 if (p->q->ops->drop == NULL)
339 return 0;
340
341 len = p->q->ops->drop(p->q);
342 if (len)
343 sch->q.qlen--;
344
345 return len;
346 }
347
348 static int dsmark_init(struct Qdisc *sch, struct nlattr *opt)
349 {
350 struct dsmark_qdisc_data *p = qdisc_priv(sch);
351 struct nlattr *tb[TCA_DSMARK_MAX + 1];
352 int err = -EINVAL;
353 u32 default_index = NO_DEFAULT_INDEX;
354 u16 indices;
355 u8 *mask;
356
357 pr_debug("dsmark_init(sch %p,[qdisc %p],opt %p)\n", sch, p, opt);
358
359 if (!opt)
360 goto errout;
361
362 err = nla_parse_nested(tb, TCA_DSMARK_MAX, opt, NULL);
363 if (err < 0)
364 goto errout;
365
366 err = -EINVAL;
367 if (nla_len(tb[TCA_DSMARK_INDICES]) < sizeof(u16))
368 goto errout;
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 if (nla_len(tb[TCA_DSMARK_DEFAULT_INDEX]) < sizeof(u16))
376 goto errout;
377 default_index = nla_get_u16(tb[TCA_DSMARK_DEFAULT_INDEX]);
378 }
379
380 mask = kmalloc(indices * 2, GFP_KERNEL);
381 if (mask == NULL) {
382 err = -ENOMEM;
383 goto errout;
384 }
385
386 p->mask = mask;
387 memset(p->mask, 0xff, indices);
388
389 p->value = p->mask + indices;
390 memset(p->value, 0, indices);
391
392 p->indices = indices;
393 p->default_index = default_index;
394 p->set_tc_index = nla_get_flag(tb[TCA_DSMARK_SET_TC_INDEX]);
395
396 p->q = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops, sch->handle);
397 if (p->q == NULL)
398 p->q = &noop_qdisc;
399
400 pr_debug("dsmark_init: qdisc %p\n", p->q);
401
402 err = 0;
403 errout:
404 return err;
405 }
406
407 static void dsmark_reset(struct Qdisc *sch)
408 {
409 struct dsmark_qdisc_data *p = qdisc_priv(sch);
410
411 pr_debug("dsmark_reset(sch %p,[qdisc %p])\n", sch, p);
412 qdisc_reset(p->q);
413 sch->q.qlen = 0;
414 }
415
416 static void dsmark_destroy(struct Qdisc *sch)
417 {
418 struct dsmark_qdisc_data *p = qdisc_priv(sch);
419
420 pr_debug("dsmark_destroy(sch %p,[qdisc %p])\n", sch, p);
421
422 tcf_destroy_chain(p->filter_list);
423 qdisc_destroy(p->q);
424 kfree(p->mask);
425 }
426
427 static int dsmark_dump_class(struct Qdisc *sch, unsigned long cl,
428 struct sk_buff *skb, struct tcmsg *tcm)
429 {
430 struct dsmark_qdisc_data *p = qdisc_priv(sch);
431 struct nlattr *opts = NULL;
432
433 pr_debug("dsmark_dump_class(sch %p,[qdisc %p],class %ld\n", sch, p, cl);
434
435 if (!dsmark_valid_index(p, cl))
436 return -EINVAL;
437
438 tcm->tcm_handle = TC_H_MAKE(TC_H_MAJ(sch->handle), cl-1);
439 tcm->tcm_info = p->q->handle;
440
441 opts = nla_nest_start(skb, TCA_OPTIONS);
442 if (opts == NULL)
443 goto nla_put_failure;
444 NLA_PUT_U8(skb, TCA_DSMARK_MASK, p->mask[cl-1]);
445 NLA_PUT_U8(skb, TCA_DSMARK_VALUE, p->value[cl-1]);
446
447 return nla_nest_end(skb, opts);
448
449 nla_put_failure:
450 return nla_nest_cancel(skb, opts);
451 }
452
453 static int dsmark_dump(struct Qdisc *sch, struct sk_buff *skb)
454 {
455 struct dsmark_qdisc_data *p = qdisc_priv(sch);
456 struct nlattr *opts = NULL;
457
458 opts = nla_nest_start(skb, TCA_OPTIONS);
459 if (opts == NULL)
460 goto nla_put_failure;
461 NLA_PUT_U16(skb, TCA_DSMARK_INDICES, p->indices);
462
463 if (p->default_index != NO_DEFAULT_INDEX)
464 NLA_PUT_U16(skb, TCA_DSMARK_DEFAULT_INDEX, p->default_index);
465
466 if (p->set_tc_index)
467 NLA_PUT_FLAG(skb, TCA_DSMARK_SET_TC_INDEX);
468
469 return nla_nest_end(skb, opts);
470
471 nla_put_failure:
472 return nla_nest_cancel(skb, opts);
473 }
474
475 static const struct Qdisc_class_ops dsmark_class_ops = {
476 .graft = dsmark_graft,
477 .leaf = dsmark_leaf,
478 .get = dsmark_get,
479 .put = dsmark_put,
480 .change = dsmark_change,
481 .delete = dsmark_delete,
482 .walk = dsmark_walk,
483 .tcf_chain = dsmark_find_tcf,
484 .bind_tcf = dsmark_bind_filter,
485 .unbind_tcf = dsmark_put,
486 .dump = dsmark_dump_class,
487 };
488
489 static struct Qdisc_ops dsmark_qdisc_ops __read_mostly = {
490 .next = NULL,
491 .cl_ops = &dsmark_class_ops,
492 .id = "dsmark",
493 .priv_size = sizeof(struct dsmark_qdisc_data),
494 .enqueue = dsmark_enqueue,
495 .dequeue = dsmark_dequeue,
496 .requeue = dsmark_requeue,
497 .drop = dsmark_drop,
498 .init = dsmark_init,
499 .reset = dsmark_reset,
500 .destroy = dsmark_destroy,
501 .change = NULL,
502 .dump = dsmark_dump,
503 .owner = THIS_MODULE,
504 };
505
506 static int __init dsmark_module_init(void)
507 {
508 return register_qdisc(&dsmark_qdisc_ops);
509 }
510
511 static void __exit dsmark_module_exit(void)
512 {
513 unregister_qdisc(&dsmark_qdisc_ops);
514 }
515
516 module_init(dsmark_module_init)
517 module_exit(dsmark_module_exit)
518
519 MODULE_LICENSE("GPL");
linux kernel for loongson