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v4.6
 
  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
 38struct mask_value {
 39	u8			mask;
 40	u8			value;
 41};
 42
 43struct dsmark_qdisc_data {
 44	struct Qdisc		*q;
 45	struct tcf_proto __rcu	*filter_list;
 
 46	struct mask_value	*mv;
 47	u16			indices;
 48	u8			set_tc_index;
 49	u32			default_index;	/* index range is 0...0xffff */
 50#define DSMARK_EMBEDDED_SZ	16
 51	struct mask_value	embedded[DSMARK_EMBEDDED_SZ];
 52};
 53
 54static inline int dsmark_valid_index(struct dsmark_qdisc_data *p, u16 index)
 55{
 56	return index <= p->indices && index > 0;
 57}
 58
 59/* ------------------------- Class/flow operations ------------------------- */
 60
 61static int dsmark_graft(struct Qdisc *sch, unsigned long arg,
 62			struct Qdisc *new, struct Qdisc **old)
 
 63{
 64	struct dsmark_qdisc_data *p = qdisc_priv(sch);
 65
 66	pr_debug("%s(sch %p,[qdisc %p],new %p,old %p)\n",
 67		 __func__, sch, p, new, old);
 68
 69	if (new == NULL) {
 70		new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
 71					sch->handle);
 72		if (new == NULL)
 73			new = &noop_qdisc;
 74	}
 75
 76	*old = qdisc_replace(sch, new, &p->q);
 77	return 0;
 78}
 79
 80static struct Qdisc *dsmark_leaf(struct Qdisc *sch, unsigned long arg)
 81{
 82	struct dsmark_qdisc_data *p = qdisc_priv(sch);
 83	return p->q;
 84}
 85
 86static unsigned long dsmark_get(struct Qdisc *sch, u32 classid)
 87{
 88	pr_debug("%s(sch %p,[qdisc %p],classid %x)\n",
 89		 __func__, sch, qdisc_priv(sch), classid);
 90
 91	return TC_H_MIN(classid) + 1;
 92}
 93
 94static unsigned long dsmark_bind_filter(struct Qdisc *sch,
 95					unsigned long parent, u32 classid)
 96{
 97	return dsmark_get(sch, classid);
 
 
 
 98}
 99
100static void dsmark_put(struct Qdisc *sch, unsigned long cl)
101{
102}
103
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
112static int dsmark_change(struct Qdisc *sch, u32 classid, u32 parent,
113			 struct nlattr **tca, unsigned long *arg)
 
114{
115	struct dsmark_qdisc_data *p = qdisc_priv(sch);
116	struct nlattr *opt = tca[TCA_OPTIONS];
117	struct nlattr *tb[TCA_DSMARK_MAX + 1];
118	int err = -EINVAL;
119
120	pr_debug("%s(sch %p,[qdisc %p],classid %x,parent %x), arg 0x%lx\n",
121		 __func__, sch, p, classid, parent, *arg);
122
123	if (!dsmark_valid_index(p, *arg)) {
124		err = -ENOENT;
125		goto errout;
126	}
127
128	if (!opt)
129		goto errout;
130
131	err = nla_parse_nested(tb, TCA_DSMARK_MAX, opt, dsmark_policy);
 
132	if (err < 0)
133		goto errout;
134
135	if (tb[TCA_DSMARK_VALUE])
136		p->mv[*arg - 1].value = nla_get_u8(tb[TCA_DSMARK_VALUE]);
137
138	if (tb[TCA_DSMARK_MASK])
139		p->mv[*arg - 1].mask = nla_get_u8(tb[TCA_DSMARK_MASK]);
140
141	err = 0;
142
143errout:
144	return err;
145}
146
147static 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->mv[arg - 1].mask = 0xff;
155	p->mv[arg - 1].value = 0;
156
157	return 0;
158}
159
160static 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("%s(sch %p,[qdisc %p],walker %p)\n",
166		 __func__, sch, p, walker);
167
168	if (walker->stop)
169		return;
170
171	for (i = 0; i < p->indices; i++) {
172		if (p->mv[i].mask == 0xff && !p->mv[i].value)
173			goto ignore;
174		if (walker->count >= walker->skip) {
175			if (walker->fn(sch, i + 1, walker) < 0) {
176				walker->stop = 1;
177				break;
178			}
179		}
180ignore:
181		walker->count++;
182	}
183}
184
185static inline struct tcf_proto __rcu **dsmark_find_tcf(struct Qdisc *sch,
186						       unsigned long cl)
187{
188	struct dsmark_qdisc_data *p = qdisc_priv(sch);
189	return &p->filter_list;
 
190}
191
192/* --------------------------- Qdisc operations ---------------------------- */
193
194static int dsmark_enqueue(struct sk_buff *skb, struct Qdisc *sch)
 
195{
 
196	struct dsmark_qdisc_data *p = qdisc_priv(sch);
197	int err;
198
199	pr_debug("%s(skb %p,sch %p,[qdisc %p])\n", __func__, skb, sch, p);
200
201	if (p->set_tc_index) {
 
 
202		switch (tc_skb_protocol(skb)) {
203		case htons(ETH_P_IP):
204			if (skb_cow_head(skb, sizeof(struct iphdr)))
 
 
205				goto drop;
206
207			skb->tc_index = ipv4_get_dsfield(ip_hdr(skb))
208				& ~INET_ECN_MASK;
209			break;
210
211		case htons(ETH_P_IPV6):
212			if (skb_cow_head(skb, sizeof(struct ipv6hdr)))
 
 
213				goto drop;
214
215			skb->tc_index = ipv6_get_dsfield(ipv6_hdr(skb))
216				& ~INET_ECN_MASK;
217			break;
218		default:
219			skb->tc_index = 0;
220			break;
221		}
222	}
223
224	if (TC_H_MAJ(skb->priority) == sch->handle)
225		skb->tc_index = TC_H_MIN(skb->priority);
226	else {
227		struct tcf_result res;
228		struct tcf_proto *fl = rcu_dereference_bh(p->filter_list);
229		int result = tc_classify(skb, fl, &res, false);
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 | __NET_XMIT_STOLEN;
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 = qdisc_enqueue(skb, p->q);
255	if (err != NET_XMIT_SUCCESS) {
256		if (net_xmit_drop_count(err))
257			qdisc_qstats_drop(sch);
258		return err;
259	}
260
261	qdisc_qstats_backlog_inc(sch, skb);
262	sch->q.qlen++;
263
264	return NET_XMIT_SUCCESS;
265
266drop:
267	qdisc_drop(skb, sch);
268	return NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
269}
270
271static struct sk_buff *dsmark_dequeue(struct Qdisc *sch)
272{
273	struct dsmark_qdisc_data *p = qdisc_priv(sch);
274	struct sk_buff *skb;
275	u32 index;
276
277	pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
278
279	skb = qdisc_dequeue_peeked(p->q);
280	if (skb == NULL)
281		return NULL;
282
283	qdisc_bstats_update(sch, skb);
284	qdisc_qstats_backlog_dec(sch, skb);
285	sch->q.qlen--;
286
287	index = skb->tc_index & (p->indices - 1);
288	pr_debug("index %d->%d\n", skb->tc_index, index);
289
290	switch (tc_skb_protocol(skb)) {
291	case htons(ETH_P_IP):
292		ipv4_change_dsfield(ip_hdr(skb), p->mv[index].mask,
293				    p->mv[index].value);
294			break;
295	case htons(ETH_P_IPV6):
296		ipv6_change_dsfield(ipv6_hdr(skb), p->mv[index].mask,
297				    p->mv[index].value);
298			break;
299	default:
300		/*
301		 * Only complain if a change was actually attempted.
302		 * This way, we can send non-IP traffic through dsmark
303		 * and don't need yet another qdisc as a bypass.
304		 */
305		if (p->mv[index].mask != 0xff || p->mv[index].value)
306			pr_warn("%s: unsupported protocol %d\n",
307				__func__, ntohs(tc_skb_protocol(skb)));
308		break;
309	}
310
311	return skb;
312}
313
314static struct sk_buff *dsmark_peek(struct Qdisc *sch)
315{
316	struct dsmark_qdisc_data *p = qdisc_priv(sch);
317
318	pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
319
320	return p->q->ops->peek(p->q);
321}
322
323static unsigned int dsmark_drop(struct Qdisc *sch)
324{
325	struct dsmark_qdisc_data *p = qdisc_priv(sch);
326	unsigned int len;
327
328	pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
329
330	if (p->q->ops->drop == NULL)
331		return 0;
332
333	len = p->q->ops->drop(p->q);
334	if (len)
335		sch->q.qlen--;
336
337	return len;
338}
339
340static int dsmark_init(struct Qdisc *sch, struct nlattr *opt)
341{
342	struct dsmark_qdisc_data *p = qdisc_priv(sch);
343	struct nlattr *tb[TCA_DSMARK_MAX + 1];
344	int err = -EINVAL;
345	u32 default_index = NO_DEFAULT_INDEX;
346	u16 indices;
347	int i;
348
349	pr_debug("%s(sch %p,[qdisc %p],opt %p)\n", __func__, sch, p, opt);
350
351	if (!opt)
352		goto errout;
353
354	err = nla_parse_nested(tb, TCA_DSMARK_MAX, opt, dsmark_policy);
 
 
 
 
 
355	if (err < 0)
356		goto errout;
357
358	err = -EINVAL;
 
 
359	indices = nla_get_u16(tb[TCA_DSMARK_INDICES]);
360
361	if (hweight32(indices) != 1)
362		goto errout;
363
364	if (tb[TCA_DSMARK_DEFAULT_INDEX])
365		default_index = nla_get_u16(tb[TCA_DSMARK_DEFAULT_INDEX]);
366
367	if (indices <= DSMARK_EMBEDDED_SZ)
368		p->mv = p->embedded;
369	else
370		p->mv = kmalloc_array(indices, sizeof(*p->mv), GFP_KERNEL);
371	if (!p->mv) {
372		err = -ENOMEM;
373		goto errout;
374	}
375	for (i = 0; i < indices; i++) {
376		p->mv[i].mask = 0xff;
377		p->mv[i].value = 0;
378	}
379	p->indices = indices;
380	p->default_index = default_index;
381	p->set_tc_index = nla_get_flag(tb[TCA_DSMARK_SET_TC_INDEX]);
382
383	p->q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, sch->handle);
 
384	if (p->q == NULL)
385		p->q = &noop_qdisc;
 
 
386
387	pr_debug("%s: qdisc %p\n", __func__, p->q);
388
389	err = 0;
390errout:
391	return err;
392}
393
394static void dsmark_reset(struct Qdisc *sch)
395{
396	struct dsmark_qdisc_data *p = qdisc_priv(sch);
397
398	pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
399	qdisc_reset(p->q);
400	sch->qstats.backlog = 0;
401	sch->q.qlen = 0;
402}
403
404static void dsmark_destroy(struct Qdisc *sch)
405{
406	struct dsmark_qdisc_data *p = qdisc_priv(sch);
407
408	pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
409
410	tcf_destroy_chain(&p->filter_list);
411	qdisc_destroy(p->q);
412	if (p->mv != p->embedded)
413		kfree(p->mv);
414}
415
416static int dsmark_dump_class(struct Qdisc *sch, unsigned long cl,
417			     struct sk_buff *skb, struct tcmsg *tcm)
418{
419	struct dsmark_qdisc_data *p = qdisc_priv(sch);
420	struct nlattr *opts = NULL;
421
422	pr_debug("%s(sch %p,[qdisc %p],class %ld\n", __func__, sch, p, cl);
423
424	if (!dsmark_valid_index(p, cl))
425		return -EINVAL;
426
427	tcm->tcm_handle = TC_H_MAKE(TC_H_MAJ(sch->handle), cl - 1);
428	tcm->tcm_info = p->q->handle;
429
430	opts = nla_nest_start(skb, TCA_OPTIONS);
431	if (opts == NULL)
432		goto nla_put_failure;
433	if (nla_put_u8(skb, TCA_DSMARK_MASK, p->mv[cl - 1].mask) ||
434	    nla_put_u8(skb, TCA_DSMARK_VALUE, p->mv[cl - 1].value))
435		goto nla_put_failure;
436
437	return nla_nest_end(skb, opts);
438
439nla_put_failure:
440	nla_nest_cancel(skb, opts);
441	return -EMSGSIZE;
442}
443
444static int dsmark_dump(struct Qdisc *sch, struct sk_buff *skb)
445{
446	struct dsmark_qdisc_data *p = qdisc_priv(sch);
447	struct nlattr *opts = NULL;
448
449	opts = nla_nest_start(skb, TCA_OPTIONS);
450	if (opts == NULL)
451		goto nla_put_failure;
452	if (nla_put_u16(skb, TCA_DSMARK_INDICES, p->indices))
453		goto nla_put_failure;
454
455	if (p->default_index != NO_DEFAULT_INDEX &&
456	    nla_put_u16(skb, TCA_DSMARK_DEFAULT_INDEX, p->default_index))
457		goto nla_put_failure;
458
459	if (p->set_tc_index &&
460	    nla_put_flag(skb, TCA_DSMARK_SET_TC_INDEX))
461		goto nla_put_failure;
462
463	return nla_nest_end(skb, opts);
464
465nla_put_failure:
466	nla_nest_cancel(skb, opts);
467	return -EMSGSIZE;
468}
469
470static const struct Qdisc_class_ops dsmark_class_ops = {
471	.graft		=	dsmark_graft,
472	.leaf		=	dsmark_leaf,
473	.get		=	dsmark_get,
474	.put		=	dsmark_put,
475	.change		=	dsmark_change,
476	.delete		=	dsmark_delete,
477	.walk		=	dsmark_walk,
478	.tcf_chain	=	dsmark_find_tcf,
479	.bind_tcf	=	dsmark_bind_filter,
480	.unbind_tcf	=	dsmark_put,
481	.dump		=	dsmark_dump_class,
482};
483
484static struct Qdisc_ops dsmark_qdisc_ops __read_mostly = {
485	.next		=	NULL,
486	.cl_ops		=	&dsmark_class_ops,
487	.id		=	"dsmark",
488	.priv_size	=	sizeof(struct dsmark_qdisc_data),
489	.enqueue	=	dsmark_enqueue,
490	.dequeue	=	dsmark_dequeue,
491	.peek		=	dsmark_peek,
492	.drop		=	dsmark_drop,
493	.init		=	dsmark_init,
494	.reset		=	dsmark_reset,
495	.destroy	=	dsmark_destroy,
496	.change		=	NULL,
497	.dump		=	dsmark_dump,
498	.owner		=	THIS_MODULE,
499};
500
501static int __init dsmark_module_init(void)
502{
503	return register_qdisc(&dsmark_qdisc_ops);
504}
505
506static void __exit dsmark_module_exit(void)
507{
508	unregister_qdisc(&dsmark_qdisc_ops);
509}
510
511module_init(dsmark_module_init)
512module_exit(dsmark_module_exit)
513
514MODULE_LICENSE("GPL");
v5.4
  1// SPDX-License-Identifier: GPL-2.0-only
  2/* net/sched/sch_dsmark.c - Differentiated Services field marker */
  3
  4/* Written 1998-2000 by Werner Almesberger, EPFL ICA */
  5
  6
  7#include <linux/module.h>
  8#include <linux/init.h>
  9#include <linux/slab.h>
 10#include <linux/types.h>
 11#include <linux/string.h>
 12#include <linux/errno.h>
 13#include <linux/skbuff.h>
 14#include <linux/rtnetlink.h>
 15#include <linux/bitops.h>
 16#include <net/pkt_sched.h>
 17#include <net/pkt_cls.h>
 18#include <net/dsfield.h>
 19#include <net/inet_ecn.h>
 20#include <asm/byteorder.h>
 21
 22/*
 23 * classid	class		marking
 24 * -------	-----		-------
 25 *   n/a	  0		n/a
 26 *   x:0	  1		use entry [0]
 27 *   ...	 ...		...
 28 *   x:y y>0	 y+1		use entry [y]
 29 *   ...	 ...		...
 30 * x:indices-1	indices		use entry [indices-1]
 31 *   ...	 ...		...
 32 *   x:y	 y+1		use entry [y & (indices-1)]
 33 *   ...	 ...		...
 34 * 0xffff	0x10000		use entry [indices-1]
 35 */
 36
 37
 38#define NO_DEFAULT_INDEX	(1 << 16)
 39
 40struct mask_value {
 41	u8			mask;
 42	u8			value;
 43};
 44
 45struct dsmark_qdisc_data {
 46	struct Qdisc		*q;
 47	struct tcf_proto __rcu	*filter_list;
 48	struct tcf_block	*block;
 49	struct mask_value	*mv;
 50	u16			indices;
 51	u8			set_tc_index;
 52	u32			default_index;	/* index range is 0...0xffff */
 53#define DSMARK_EMBEDDED_SZ	16
 54	struct mask_value	embedded[DSMARK_EMBEDDED_SZ];
 55};
 56
 57static inline int dsmark_valid_index(struct dsmark_qdisc_data *p, u16 index)
 58{
 59	return index <= p->indices && index > 0;
 60}
 61
 62/* ------------------------- Class/flow operations ------------------------- */
 63
 64static int dsmark_graft(struct Qdisc *sch, unsigned long arg,
 65			struct Qdisc *new, struct Qdisc **old,
 66			struct netlink_ext_ack *extack)
 67{
 68	struct dsmark_qdisc_data *p = qdisc_priv(sch);
 69
 70	pr_debug("%s(sch %p,[qdisc %p],new %p,old %p)\n",
 71		 __func__, sch, p, new, old);
 72
 73	if (new == NULL) {
 74		new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
 75					sch->handle, NULL);
 76		if (new == NULL)
 77			new = &noop_qdisc;
 78	}
 79
 80	*old = qdisc_replace(sch, new, &p->q);
 81	return 0;
 82}
 83
 84static struct Qdisc *dsmark_leaf(struct Qdisc *sch, unsigned long arg)
 85{
 86	struct dsmark_qdisc_data *p = qdisc_priv(sch);
 87	return p->q;
 88}
 89
 90static unsigned long dsmark_find(struct Qdisc *sch, u32 classid)
 91{
 
 
 
 92	return TC_H_MIN(classid) + 1;
 93}
 94
 95static unsigned long dsmark_bind_filter(struct Qdisc *sch,
 96					unsigned long parent, u32 classid)
 97{
 98	pr_debug("%s(sch %p,[qdisc %p],classid %x)\n",
 99		 __func__, sch, qdisc_priv(sch), classid);
100
101	return dsmark_find(sch, classid);
102}
103
104static void dsmark_unbind_filter(struct Qdisc *sch, unsigned long cl)
105{
106}
107
108static const struct nla_policy dsmark_policy[TCA_DSMARK_MAX + 1] = {
109	[TCA_DSMARK_INDICES]		= { .type = NLA_U16 },
110	[TCA_DSMARK_DEFAULT_INDEX]	= { .type = NLA_U16 },
111	[TCA_DSMARK_SET_TC_INDEX]	= { .type = NLA_FLAG },
112	[TCA_DSMARK_MASK]		= { .type = NLA_U8 },
113	[TCA_DSMARK_VALUE]		= { .type = NLA_U8 },
114};
115
116static int dsmark_change(struct Qdisc *sch, u32 classid, u32 parent,
117			 struct nlattr **tca, unsigned long *arg,
118			 struct netlink_ext_ack *extack)
119{
120	struct dsmark_qdisc_data *p = qdisc_priv(sch);
121	struct nlattr *opt = tca[TCA_OPTIONS];
122	struct nlattr *tb[TCA_DSMARK_MAX + 1];
123	int err = -EINVAL;
124
125	pr_debug("%s(sch %p,[qdisc %p],classid %x,parent %x), arg 0x%lx\n",
126		 __func__, sch, p, classid, parent, *arg);
127
128	if (!dsmark_valid_index(p, *arg)) {
129		err = -ENOENT;
130		goto errout;
131	}
132
133	if (!opt)
134		goto errout;
135
136	err = nla_parse_nested_deprecated(tb, TCA_DSMARK_MAX, opt,
137					  dsmark_policy, NULL);
138	if (err < 0)
139		goto errout;
140
141	if (tb[TCA_DSMARK_VALUE])
142		p->mv[*arg - 1].value = nla_get_u8(tb[TCA_DSMARK_VALUE]);
143
144	if (tb[TCA_DSMARK_MASK])
145		p->mv[*arg - 1].mask = nla_get_u8(tb[TCA_DSMARK_MASK]);
146
147	err = 0;
148
149errout:
150	return err;
151}
152
153static int dsmark_delete(struct Qdisc *sch, unsigned long arg)
154{
155	struct dsmark_qdisc_data *p = qdisc_priv(sch);
156
157	if (!dsmark_valid_index(p, arg))
158		return -EINVAL;
159
160	p->mv[arg - 1].mask = 0xff;
161	p->mv[arg - 1].value = 0;
162
163	return 0;
164}
165
166static void dsmark_walk(struct Qdisc *sch, struct qdisc_walker *walker)
167{
168	struct dsmark_qdisc_data *p = qdisc_priv(sch);
169	int i;
170
171	pr_debug("%s(sch %p,[qdisc %p],walker %p)\n",
172		 __func__, sch, p, walker);
173
174	if (walker->stop)
175		return;
176
177	for (i = 0; i < p->indices; i++) {
178		if (p->mv[i].mask == 0xff && !p->mv[i].value)
179			goto ignore;
180		if (walker->count >= walker->skip) {
181			if (walker->fn(sch, i + 1, walker) < 0) {
182				walker->stop = 1;
183				break;
184			}
185		}
186ignore:
187		walker->count++;
188	}
189}
190
191static struct tcf_block *dsmark_tcf_block(struct Qdisc *sch, unsigned long cl,
192					  struct netlink_ext_ack *extack)
193{
194	struct dsmark_qdisc_data *p = qdisc_priv(sch);
195
196	return p->block;
197}
198
199/* --------------------------- Qdisc operations ---------------------------- */
200
201static int dsmark_enqueue(struct sk_buff *skb, struct Qdisc *sch,
202			  struct sk_buff **to_free)
203{
204	unsigned int len = qdisc_pkt_len(skb);
205	struct dsmark_qdisc_data *p = qdisc_priv(sch);
206	int err;
207
208	pr_debug("%s(skb %p,sch %p,[qdisc %p])\n", __func__, skb, sch, p);
209
210	if (p->set_tc_index) {
211		int wlen = skb_network_offset(skb);
212
213		switch (tc_skb_protocol(skb)) {
214		case htons(ETH_P_IP):
215			wlen += sizeof(struct iphdr);
216			if (!pskb_may_pull(skb, wlen) ||
217			    skb_try_make_writable(skb, wlen))
218				goto drop;
219
220			skb->tc_index = ipv4_get_dsfield(ip_hdr(skb))
221				& ~INET_ECN_MASK;
222			break;
223
224		case htons(ETH_P_IPV6):
225			wlen += sizeof(struct ipv6hdr);
226			if (!pskb_may_pull(skb, wlen) ||
227			    skb_try_make_writable(skb, wlen))
228				goto drop;
229
230			skb->tc_index = ipv6_get_dsfield(ipv6_hdr(skb))
231				& ~INET_ECN_MASK;
232			break;
233		default:
234			skb->tc_index = 0;
235			break;
236		}
237	}
238
239	if (TC_H_MAJ(skb->priority) == sch->handle)
240		skb->tc_index = TC_H_MIN(skb->priority);
241	else {
242		struct tcf_result res;
243		struct tcf_proto *fl = rcu_dereference_bh(p->filter_list);
244		int result = tcf_classify(skb, fl, &res, false);
245
246		pr_debug("result %d class 0x%04x\n", result, res.classid);
247
248		switch (result) {
249#ifdef CONFIG_NET_CLS_ACT
250		case TC_ACT_QUEUED:
251		case TC_ACT_STOLEN:
252		case TC_ACT_TRAP:
253			__qdisc_drop(skb, to_free);
254			return NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
255
256		case TC_ACT_SHOT:
257			goto drop;
258#endif
259		case TC_ACT_OK:
260			skb->tc_index = TC_H_MIN(res.classid);
261			break;
262
263		default:
264			if (p->default_index != NO_DEFAULT_INDEX)
265				skb->tc_index = p->default_index;
266			break;
267		}
268	}
269
270	err = qdisc_enqueue(skb, p->q, to_free);
271	if (err != NET_XMIT_SUCCESS) {
272		if (net_xmit_drop_count(err))
273			qdisc_qstats_drop(sch);
274		return err;
275	}
276
277	sch->qstats.backlog += len;
278	sch->q.qlen++;
279
280	return NET_XMIT_SUCCESS;
281
282drop:
283	qdisc_drop(skb, sch, to_free);
284	return NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
285}
286
287static struct sk_buff *dsmark_dequeue(struct Qdisc *sch)
288{
289	struct dsmark_qdisc_data *p = qdisc_priv(sch);
290	struct sk_buff *skb;
291	u32 index;
292
293	pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
294
295	skb = qdisc_dequeue_peeked(p->q);
296	if (skb == NULL)
297		return NULL;
298
299	qdisc_bstats_update(sch, skb);
300	qdisc_qstats_backlog_dec(sch, skb);
301	sch->q.qlen--;
302
303	index = skb->tc_index & (p->indices - 1);
304	pr_debug("index %d->%d\n", skb->tc_index, index);
305
306	switch (tc_skb_protocol(skb)) {
307	case htons(ETH_P_IP):
308		ipv4_change_dsfield(ip_hdr(skb), p->mv[index].mask,
309				    p->mv[index].value);
310			break;
311	case htons(ETH_P_IPV6):
312		ipv6_change_dsfield(ipv6_hdr(skb), p->mv[index].mask,
313				    p->mv[index].value);
314			break;
315	default:
316		/*
317		 * Only complain if a change was actually attempted.
318		 * This way, we can send non-IP traffic through dsmark
319		 * and don't need yet another qdisc as a bypass.
320		 */
321		if (p->mv[index].mask != 0xff || p->mv[index].value)
322			pr_warn("%s: unsupported protocol %d\n",
323				__func__, ntohs(tc_skb_protocol(skb)));
324		break;
325	}
326
327	return skb;
328}
329
330static struct sk_buff *dsmark_peek(struct Qdisc *sch)
331{
332	struct dsmark_qdisc_data *p = qdisc_priv(sch);
333
334	pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
335
336	return p->q->ops->peek(p->q);
337}
338
339static int dsmark_init(struct Qdisc *sch, struct nlattr *opt,
340		       struct netlink_ext_ack *extack)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
341{
342	struct dsmark_qdisc_data *p = qdisc_priv(sch);
343	struct nlattr *tb[TCA_DSMARK_MAX + 1];
344	int err = -EINVAL;
345	u32 default_index = NO_DEFAULT_INDEX;
346	u16 indices;
347	int i;
348
349	pr_debug("%s(sch %p,[qdisc %p],opt %p)\n", __func__, sch, p, opt);
350
351	if (!opt)
352		goto errout;
353
354	err = tcf_block_get(&p->block, &p->filter_list, sch, extack);
355	if (err)
356		return err;
357
358	err = nla_parse_nested_deprecated(tb, TCA_DSMARK_MAX, opt,
359					  dsmark_policy, NULL);
360	if (err < 0)
361		goto errout;
362
363	err = -EINVAL;
364	if (!tb[TCA_DSMARK_INDICES])
365		goto errout;
366	indices = nla_get_u16(tb[TCA_DSMARK_INDICES]);
367
368	if (hweight32(indices) != 1)
369		goto errout;
370
371	if (tb[TCA_DSMARK_DEFAULT_INDEX])
372		default_index = nla_get_u16(tb[TCA_DSMARK_DEFAULT_INDEX]);
373
374	if (indices <= DSMARK_EMBEDDED_SZ)
375		p->mv = p->embedded;
376	else
377		p->mv = kmalloc_array(indices, sizeof(*p->mv), GFP_KERNEL);
378	if (!p->mv) {
379		err = -ENOMEM;
380		goto errout;
381	}
382	for (i = 0; i < indices; i++) {
383		p->mv[i].mask = 0xff;
384		p->mv[i].value = 0;
385	}
386	p->indices = indices;
387	p->default_index = default_index;
388	p->set_tc_index = nla_get_flag(tb[TCA_DSMARK_SET_TC_INDEX]);
389
390	p->q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, sch->handle,
391				 NULL);
392	if (p->q == NULL)
393		p->q = &noop_qdisc;
394	else
395		qdisc_hash_add(p->q, true);
396
397	pr_debug("%s: qdisc %p\n", __func__, p->q);
398
399	err = 0;
400errout:
401	return err;
402}
403
404static void dsmark_reset(struct Qdisc *sch)
405{
406	struct dsmark_qdisc_data *p = qdisc_priv(sch);
407
408	pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
409	qdisc_reset(p->q);
410	sch->qstats.backlog = 0;
411	sch->q.qlen = 0;
412}
413
414static void dsmark_destroy(struct Qdisc *sch)
415{
416	struct dsmark_qdisc_data *p = qdisc_priv(sch);
417
418	pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
419
420	tcf_block_put(p->block);
421	qdisc_put(p->q);
422	if (p->mv != p->embedded)
423		kfree(p->mv);
424}
425
426static int dsmark_dump_class(struct Qdisc *sch, unsigned long cl,
427			     struct sk_buff *skb, struct tcmsg *tcm)
428{
429	struct dsmark_qdisc_data *p = qdisc_priv(sch);
430	struct nlattr *opts = NULL;
431
432	pr_debug("%s(sch %p,[qdisc %p],class %ld\n", __func__, sch, p, cl);
433
434	if (!dsmark_valid_index(p, cl))
435		return -EINVAL;
436
437	tcm->tcm_handle = TC_H_MAKE(TC_H_MAJ(sch->handle), cl - 1);
438	tcm->tcm_info = p->q->handle;
439
440	opts = nla_nest_start_noflag(skb, TCA_OPTIONS);
441	if (opts == NULL)
442		goto nla_put_failure;
443	if (nla_put_u8(skb, TCA_DSMARK_MASK, p->mv[cl - 1].mask) ||
444	    nla_put_u8(skb, TCA_DSMARK_VALUE, p->mv[cl - 1].value))
445		goto nla_put_failure;
446
447	return nla_nest_end(skb, opts);
448
449nla_put_failure:
450	nla_nest_cancel(skb, opts);
451	return -EMSGSIZE;
452}
453
454static int dsmark_dump(struct Qdisc *sch, struct sk_buff *skb)
455{
456	struct dsmark_qdisc_data *p = qdisc_priv(sch);
457	struct nlattr *opts = NULL;
458
459	opts = nla_nest_start_noflag(skb, TCA_OPTIONS);
460	if (opts == NULL)
461		goto nla_put_failure;
462	if (nla_put_u16(skb, TCA_DSMARK_INDICES, p->indices))
463		goto nla_put_failure;
464
465	if (p->default_index != NO_DEFAULT_INDEX &&
466	    nla_put_u16(skb, TCA_DSMARK_DEFAULT_INDEX, p->default_index))
467		goto nla_put_failure;
468
469	if (p->set_tc_index &&
470	    nla_put_flag(skb, TCA_DSMARK_SET_TC_INDEX))
471		goto nla_put_failure;
472
473	return nla_nest_end(skb, opts);
474
475nla_put_failure:
476	nla_nest_cancel(skb, opts);
477	return -EMSGSIZE;
478}
479
480static const struct Qdisc_class_ops dsmark_class_ops = {
481	.graft		=	dsmark_graft,
482	.leaf		=	dsmark_leaf,
483	.find		=	dsmark_find,
 
484	.change		=	dsmark_change,
485	.delete		=	dsmark_delete,
486	.walk		=	dsmark_walk,
487	.tcf_block	=	dsmark_tcf_block,
488	.bind_tcf	=	dsmark_bind_filter,
489	.unbind_tcf	=	dsmark_unbind_filter,
490	.dump		=	dsmark_dump_class,
491};
492
493static struct Qdisc_ops dsmark_qdisc_ops __read_mostly = {
494	.next		=	NULL,
495	.cl_ops		=	&dsmark_class_ops,
496	.id		=	"dsmark",
497	.priv_size	=	sizeof(struct dsmark_qdisc_data),
498	.enqueue	=	dsmark_enqueue,
499	.dequeue	=	dsmark_dequeue,
500	.peek		=	dsmark_peek,
 
501	.init		=	dsmark_init,
502	.reset		=	dsmark_reset,
503	.destroy	=	dsmark_destroy,
504	.change		=	NULL,
505	.dump		=	dsmark_dump,
506	.owner		=	THIS_MODULE,
507};
508
509static int __init dsmark_module_init(void)
510{
511	return register_qdisc(&dsmark_qdisc_ops);
512}
513
514static void __exit dsmark_module_exit(void)
515{
516	unregister_qdisc(&dsmark_qdisc_ops);
517}
518
519module_init(dsmark_module_init)
520module_exit(dsmark_module_exit)
521
522MODULE_LICENSE("GPL");