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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");
v5.14.15
  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			 struct netlink_ext_ack *extack)
155{
156	struct dsmark_qdisc_data *p = qdisc_priv(sch);
157
158	if (!dsmark_valid_index(p, arg))
159		return -EINVAL;
160
161	p->mv[arg - 1].mask = 0xff;
162	p->mv[arg - 1].value = 0;
163
164	return 0;
165}
166
167static void dsmark_walk(struct Qdisc *sch, struct qdisc_walker *walker)
168{
169	struct dsmark_qdisc_data *p = qdisc_priv(sch);
170	int i;
171
172	pr_debug("%s(sch %p,[qdisc %p],walker %p)\n",
173		 __func__, sch, p, walker);
174
175	if (walker->stop)
176		return;
177
178	for (i = 0; i < p->indices; i++) {
179		if (p->mv[i].mask == 0xff && !p->mv[i].value)
180			goto ignore;
181		if (walker->count >= walker->skip) {
182			if (walker->fn(sch, i + 1, walker) < 0) {
183				walker->stop = 1;
184				break;
185			}
186		}
187ignore:
188		walker->count++;
189	}
190}
191
192static struct tcf_block *dsmark_tcf_block(struct Qdisc *sch, unsigned long cl,
193					  struct netlink_ext_ack *extack)
194{
195	struct dsmark_qdisc_data *p = qdisc_priv(sch);
196
197	return p->block;
198}
199
200/* --------------------------- Qdisc operations ---------------------------- */
201
202static int dsmark_enqueue(struct sk_buff *skb, struct Qdisc *sch,
203			  struct sk_buff **to_free)
204{
205	unsigned int len = qdisc_pkt_len(skb);
206	struct dsmark_qdisc_data *p = qdisc_priv(sch);
207	int err;
208
209	pr_debug("%s(skb %p,sch %p,[qdisc %p])\n", __func__, skb, sch, p);
210
211	if (p->set_tc_index) {
212		int wlen = skb_network_offset(skb);
213
214		switch (skb_protocol(skb, true)) {
215		case htons(ETH_P_IP):
216			wlen += sizeof(struct iphdr);
217			if (!pskb_may_pull(skb, wlen) ||
218			    skb_try_make_writable(skb, wlen))
219				goto drop;
220
221			skb->tc_index = ipv4_get_dsfield(ip_hdr(skb))
222				& ~INET_ECN_MASK;
223			break;
224
225		case htons(ETH_P_IPV6):
226			wlen += sizeof(struct ipv6hdr);
227			if (!pskb_may_pull(skb, wlen) ||
228			    skb_try_make_writable(skb, wlen))
229				goto drop;
230
231			skb->tc_index = ipv6_get_dsfield(ipv6_hdr(skb))
232				& ~INET_ECN_MASK;
233			break;
234		default:
235			skb->tc_index = 0;
236			break;
237		}
238	}
239
240	if (TC_H_MAJ(skb->priority) == sch->handle)
241		skb->tc_index = TC_H_MIN(skb->priority);
242	else {
243		struct tcf_result res;
244		struct tcf_proto *fl = rcu_dereference_bh(p->filter_list);
245		int result = tcf_classify(skb, fl, &res, false);
246
247		pr_debug("result %d class 0x%04x\n", result, res.classid);
248
249		switch (result) {
250#ifdef CONFIG_NET_CLS_ACT
251		case TC_ACT_QUEUED:
252		case TC_ACT_STOLEN:
253		case TC_ACT_TRAP:
254			__qdisc_drop(skb, to_free);
255			return NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
256
257		case TC_ACT_SHOT:
258			goto drop;
259#endif
260		case TC_ACT_OK:
261			skb->tc_index = TC_H_MIN(res.classid);
262			break;
263
264		default:
265			if (p->default_index != NO_DEFAULT_INDEX)
266				skb->tc_index = p->default_index;
267			break;
268		}
269	}
270
271	err = qdisc_enqueue(skb, p->q, to_free);
272	if (err != NET_XMIT_SUCCESS) {
273		if (net_xmit_drop_count(err))
274			qdisc_qstats_drop(sch);
275		return err;
276	}
277
278	sch->qstats.backlog += len;
279	sch->q.qlen++;
280
281	return NET_XMIT_SUCCESS;
282
283drop:
284	qdisc_drop(skb, sch, to_free);
285	return NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
286}
287
288static struct sk_buff *dsmark_dequeue(struct Qdisc *sch)
289{
290	struct dsmark_qdisc_data *p = qdisc_priv(sch);
291	struct sk_buff *skb;
292	u32 index;
293
294	pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
295
296	skb = qdisc_dequeue_peeked(p->q);
297	if (skb == NULL)
298		return NULL;
299
300	qdisc_bstats_update(sch, skb);
301	qdisc_qstats_backlog_dec(sch, skb);
302	sch->q.qlen--;
303
304	index = skb->tc_index & (p->indices - 1);
305	pr_debug("index %d->%d\n", skb->tc_index, index);
306
307	switch (skb_protocol(skb, true)) {
308	case htons(ETH_P_IP):
309		ipv4_change_dsfield(ip_hdr(skb), p->mv[index].mask,
310				    p->mv[index].value);
311			break;
312	case htons(ETH_P_IPV6):
313		ipv6_change_dsfield(ipv6_hdr(skb), p->mv[index].mask,
314				    p->mv[index].value);
315			break;
316	default:
317		/*
318		 * Only complain if a change was actually attempted.
319		 * This way, we can send non-IP traffic through dsmark
320		 * and don't need yet another qdisc as a bypass.
321		 */
322		if (p->mv[index].mask != 0xff || p->mv[index].value)
323			pr_warn("%s: unsupported protocol %d\n",
324				__func__, ntohs(skb_protocol(skb, true)));
325		break;
326	}
327
328	return skb;
329}
330
331static struct sk_buff *dsmark_peek(struct Qdisc *sch)
332{
333	struct dsmark_qdisc_data *p = qdisc_priv(sch);
334
335	pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
336
337	return p->q->ops->peek(p->q);
338}
339
340static int dsmark_init(struct Qdisc *sch, struct nlattr *opt,
341		       struct netlink_ext_ack *extack)
342{
343	struct dsmark_qdisc_data *p = qdisc_priv(sch);
344	struct nlattr *tb[TCA_DSMARK_MAX + 1];
345	int err = -EINVAL;
346	u32 default_index = NO_DEFAULT_INDEX;
347	u16 indices;
348	int i;
349
350	pr_debug("%s(sch %p,[qdisc %p],opt %p)\n", __func__, sch, p, opt);
351
352	if (!opt)
353		goto errout;
354
355	err = tcf_block_get(&p->block, &p->filter_list, sch, extack);
356	if (err)
357		return err;
358
359	err = nla_parse_nested_deprecated(tb, TCA_DSMARK_MAX, opt,
360					  dsmark_policy, NULL);
361	if (err < 0)
362		goto errout;
363
364	err = -EINVAL;
365	if (!tb[TCA_DSMARK_INDICES])
366		goto errout;
367	indices = nla_get_u16(tb[TCA_DSMARK_INDICES]);
368
369	if (hweight32(indices) != 1)
370		goto errout;
371
372	if (tb[TCA_DSMARK_DEFAULT_INDEX])
373		default_index = nla_get_u16(tb[TCA_DSMARK_DEFAULT_INDEX]);
374
375	if (indices <= DSMARK_EMBEDDED_SZ)
376		p->mv = p->embedded;
377	else
378		p->mv = kmalloc_array(indices, sizeof(*p->mv), GFP_KERNEL);
379	if (!p->mv) {
380		err = -ENOMEM;
381		goto errout;
382	}
383	for (i = 0; i < indices; i++) {
384		p->mv[i].mask = 0xff;
385		p->mv[i].value = 0;
386	}
387	p->indices = indices;
388	p->default_index = default_index;
389	p->set_tc_index = nla_get_flag(tb[TCA_DSMARK_SET_TC_INDEX]);
390
391	p->q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, sch->handle,
392				 NULL);
393	if (p->q == NULL)
394		p->q = &noop_qdisc;
395	else
396		qdisc_hash_add(p->q, true);
397
398	pr_debug("%s: qdisc %p\n", __func__, p->q);
399
400	err = 0;
401errout:
402	return err;
403}
404
405static void dsmark_reset(struct Qdisc *sch)
406{
407	struct dsmark_qdisc_data *p = qdisc_priv(sch);
408
409	pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
410	if (p->q)
411		qdisc_reset(p->q);
412	sch->qstats.backlog = 0;
413	sch->q.qlen = 0;
414}
415
416static void dsmark_destroy(struct Qdisc *sch)
417{
418	struct dsmark_qdisc_data *p = qdisc_priv(sch);
419
420	pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
421
422	tcf_block_put(p->block);
423	qdisc_put(p->q);
424	if (p->mv != p->embedded)
425		kfree(p->mv);
426}
427
428static int dsmark_dump_class(struct Qdisc *sch, unsigned long cl,
429			     struct sk_buff *skb, struct tcmsg *tcm)
430{
431	struct dsmark_qdisc_data *p = qdisc_priv(sch);
432	struct nlattr *opts = NULL;
433
434	pr_debug("%s(sch %p,[qdisc %p],class %ld\n", __func__, sch, p, cl);
435
436	if (!dsmark_valid_index(p, cl))
437		return -EINVAL;
438
439	tcm->tcm_handle = TC_H_MAKE(TC_H_MAJ(sch->handle), cl - 1);
440	tcm->tcm_info = p->q->handle;
441
442	opts = nla_nest_start_noflag(skb, TCA_OPTIONS);
443	if (opts == NULL)
444		goto nla_put_failure;
445	if (nla_put_u8(skb, TCA_DSMARK_MASK, p->mv[cl - 1].mask) ||
446	    nla_put_u8(skb, TCA_DSMARK_VALUE, p->mv[cl - 1].value))
447		goto nla_put_failure;
448
449	return nla_nest_end(skb, opts);
450
451nla_put_failure:
452	nla_nest_cancel(skb, opts);
453	return -EMSGSIZE;
454}
455
456static int dsmark_dump(struct Qdisc *sch, struct sk_buff *skb)
457{
458	struct dsmark_qdisc_data *p = qdisc_priv(sch);
459	struct nlattr *opts = NULL;
460
461	opts = nla_nest_start_noflag(skb, TCA_OPTIONS);
462	if (opts == NULL)
463		goto nla_put_failure;
464	if (nla_put_u16(skb, TCA_DSMARK_INDICES, p->indices))
465		goto nla_put_failure;
466
467	if (p->default_index != NO_DEFAULT_INDEX &&
468	    nla_put_u16(skb, TCA_DSMARK_DEFAULT_INDEX, p->default_index))
469		goto nla_put_failure;
470
471	if (p->set_tc_index &&
472	    nla_put_flag(skb, TCA_DSMARK_SET_TC_INDEX))
473		goto nla_put_failure;
474
475	return nla_nest_end(skb, opts);
476
477nla_put_failure:
478	nla_nest_cancel(skb, opts);
479	return -EMSGSIZE;
480}
481
482static const struct Qdisc_class_ops dsmark_class_ops = {
483	.graft		=	dsmark_graft,
484	.leaf		=	dsmark_leaf,
485	.find		=	dsmark_find,
486	.change		=	dsmark_change,
487	.delete		=	dsmark_delete,
488	.walk		=	dsmark_walk,
489	.tcf_block	=	dsmark_tcf_block,
490	.bind_tcf	=	dsmark_bind_filter,
491	.unbind_tcf	=	dsmark_unbind_filter,
492	.dump		=	dsmark_dump_class,
493};
494
495static struct Qdisc_ops dsmark_qdisc_ops __read_mostly = {
496	.next		=	NULL,
497	.cl_ops		=	&dsmark_class_ops,
498	.id		=	"dsmark",
499	.priv_size	=	sizeof(struct dsmark_qdisc_data),
500	.enqueue	=	dsmark_enqueue,
501	.dequeue	=	dsmark_dequeue,
502	.peek		=	dsmark_peek,
503	.init		=	dsmark_init,
504	.reset		=	dsmark_reset,
505	.destroy	=	dsmark_destroy,
506	.change		=	NULL,
507	.dump		=	dsmark_dump,
508	.owner		=	THIS_MODULE,
509};
510
511static int __init dsmark_module_init(void)
512{
513	return register_qdisc(&dsmark_qdisc_ops);
514}
515
516static void __exit dsmark_module_exit(void)
517{
518	unregister_qdisc(&dsmark_qdisc_ops);
519}
520
521module_init(dsmark_module_init)
522module_exit(dsmark_module_exit)
523
524MODULE_LICENSE("GPL");