1 // SPDX-License-Identifier: GPL-2.0-only
2 /* net/sched/sch_atm.c - ATM VC selection "queueing discipline" */
3 
4 /* Written 1998-2000 by Werner Almesberger, EPFL ICA */
5 
6 #include <linux/module.h>
7 #include <linux/slab.h>
8 #include <linux/init.h>
9 #include <linux/interrupt.h>
10 #include <linux/string.h>
11 #include <linux/errno.h>
12 #include <linux/skbuff.h>
13 #include <linux/atmdev.h>
14 #include <linux/atmclip.h>
15 #include <linux/rtnetlink.h>
16 #include <linux/file.h>		/* for fput */
17 #include <net/netlink.h>
18 #include <net/pkt_sched.h>
19 #include <net/pkt_cls.h>
20 
21 /*
22  * The ATM queuing discipline provides a framework for invoking classifiers
23  * (aka "filters"), which in turn select classes of this queuing discipline.
24  * Each class maps the flow(s) it is handling to a given VC. Multiple classes
25  * may share the same VC.
26  *
27  * When creating a class, VCs are specified by passing the number of the open
28  * socket descriptor by which the calling process references the VC. The kernel
29  * keeps the VC open at least until all classes using it are removed.
30  *
31  * In this file, most functions are named atm_tc_* to avoid confusion with all
32  * the atm_* in net/atm. This naming convention differs from what's used in the
33  * rest of net/sched.
34  *
35  * Known bugs:
36  *  - sometimes messes up the IP stack
37  *  - any manipulations besides the few operations described in the README, are
38  *    untested and likely to crash the system
39  *  - should lock the flow while there is data in the queue (?)
40  */
41 
42 #define VCC2FLOW(vcc) ((struct atm_flow_data *) ((vcc)->user_back))
43 
44 struct atm_flow_data {
45 	struct Qdisc_class_common common;
46 	struct Qdisc		*q;	/* FIFO, TBF, etc. */
47 	struct tcf_proto __rcu	*filter_list;
48 	struct tcf_block	*block;
49 	struct atm_vcc		*vcc;	/* VCC; NULL if VCC is closed */
50 	void			(*old_pop)(struct atm_vcc *vcc,
51 					   struct sk_buff *skb); /* chaining */
52 	struct atm_qdisc_data	*parent;	/* parent qdisc */
53 	struct socket		*sock;		/* for closing */
54 	int			ref;		/* reference count */
55 	struct gnet_stats_basic_sync	bstats;
56 	struct gnet_stats_queue	qstats;
57 	struct list_head	list;
58 	struct atm_flow_data	*excess;	/* flow for excess traffic;
59 						   NULL to set CLP instead */
60 	int			hdr_len;
61 	unsigned char		hdr[];		/* header data; MUST BE LAST */
62 };
63 
64 struct atm_qdisc_data {
65 	struct atm_flow_data	link;		/* unclassified skbs go here */
66 	struct list_head	flows;		/* NB: "link" is also on this
67 						   list */
68 	struct tasklet_struct	task;		/* dequeue tasklet */
69 };
70 
71 /* ------------------------- Class/flow operations ------------------------- */
72 
lookup_flow(struct Qdisc * sch,u32 classid)73 static inline struct atm_flow_data *lookup_flow(struct Qdisc *sch, u32 classid)
74 {
75 	struct atm_qdisc_data *p = qdisc_priv(sch);
76 	struct atm_flow_data *flow;
77 
78 	list_for_each_entry(flow, &p->flows, list) {
79 		if (flow->common.classid == classid)
80 			return flow;
81 	}
82 	return NULL;
83 }
84 
atm_tc_graft(struct Qdisc * sch,unsigned long arg,struct Qdisc * new,struct Qdisc ** old,struct netlink_ext_ack * extack)85 static int atm_tc_graft(struct Qdisc *sch, unsigned long arg,
86 			struct Qdisc *new, struct Qdisc **old,
87 			struct netlink_ext_ack *extack)
88 {
89 	struct atm_qdisc_data *p = qdisc_priv(sch);
90 	struct atm_flow_data *flow = (struct atm_flow_data *)arg;
91 
92 	pr_debug("atm_tc_graft(sch %p,[qdisc %p],flow %p,new %p,old %p)\n",
93 		sch, p, flow, new, old);
94 	if (list_empty(&flow->list))
95 		return -EINVAL;
96 	if (!new)
97 		new = &noop_qdisc;
98 	*old = flow->q;
99 	flow->q = new;
100 	if (*old)
101 		qdisc_reset(*old);
102 	return 0;
103 }
104 
atm_tc_leaf(struct Qdisc * sch,unsigned long cl)105 static struct Qdisc *atm_tc_leaf(struct Qdisc *sch, unsigned long cl)
106 {
107 	struct atm_flow_data *flow = (struct atm_flow_data *)cl;
108 
109 	pr_debug("atm_tc_leaf(sch %p,flow %p)\n", sch, flow);
110 	return flow ? flow->q : NULL;
111 }
112 
atm_tc_find(struct Qdisc * sch,u32 classid)113 static unsigned long atm_tc_find(struct Qdisc *sch, u32 classid)
114 {
115 	struct atm_qdisc_data *p __maybe_unused = qdisc_priv(sch);
116 	struct atm_flow_data *flow;
117 
118 	pr_debug("%s(sch %p,[qdisc %p],classid %x)\n", __func__, sch, p, classid);
119 	flow = lookup_flow(sch, classid);
120 	pr_debug("%s: flow %p\n", __func__, flow);
121 	return (unsigned long)flow;
122 }
123 
atm_tc_bind_filter(struct Qdisc * sch,unsigned long parent,u32 classid)124 static unsigned long atm_tc_bind_filter(struct Qdisc *sch,
125 					unsigned long parent, u32 classid)
126 {
127 	struct atm_qdisc_data *p __maybe_unused = qdisc_priv(sch);
128 	struct atm_flow_data *flow;
129 
130 	pr_debug("%s(sch %p,[qdisc %p],classid %x)\n", __func__, sch, p, classid);
131 	flow = lookup_flow(sch, classid);
132 	if (flow)
133 		flow->ref++;
134 	pr_debug("%s: flow %p\n", __func__, flow);
135 	return (unsigned long)flow;
136 }
137 
138 /*
139  * atm_tc_put handles all destructions, including the ones that are explicitly
140  * requested (atm_tc_destroy, etc.). The assumption here is that we never drop
141  * anything that still seems to be in use.
142  */
atm_tc_put(struct Qdisc * sch,unsigned long cl)143 static void atm_tc_put(struct Qdisc *sch, unsigned long cl)
144 {
145 	struct atm_qdisc_data *p = qdisc_priv(sch);
146 	struct atm_flow_data *flow = (struct atm_flow_data *)cl;
147 
148 	pr_debug("atm_tc_put(sch %p,[qdisc %p],flow %p)\n", sch, p, flow);
149 	if (--flow->ref)
150 		return;
151 	pr_debug("atm_tc_put: destroying\n");
152 	list_del_init(&flow->list);
153 	pr_debug("atm_tc_put: qdisc %p\n", flow->q);
154 	qdisc_put(flow->q);
155 	tcf_block_put(flow->block);
156 	if (flow->sock) {
157 		pr_debug("atm_tc_put: f_count %ld\n",
158 			file_count(flow->sock->file));
159 		flow->vcc->pop = flow->old_pop;
160 		sockfd_put(flow->sock);
161 	}
162 	if (flow->excess)
163 		atm_tc_put(sch, (unsigned long)flow->excess);
164 	if (flow != &p->link)
165 		kfree(flow);
166 	/*
167 	 * If flow == &p->link, the qdisc no longer works at this point and
168 	 * needs to be removed. (By the caller of atm_tc_put.)
169 	 */
170 }
171 
sch_atm_pop(struct atm_vcc * vcc,struct sk_buff * skb)172 static void sch_atm_pop(struct atm_vcc *vcc, struct sk_buff *skb)
173 {
174 	struct atm_qdisc_data *p = VCC2FLOW(vcc)->parent;
175 
176 	pr_debug("sch_atm_pop(vcc %p,skb %p,[qdisc %p])\n", vcc, skb, p);
177 	VCC2FLOW(vcc)->old_pop(vcc, skb);
178 	tasklet_schedule(&p->task);
179 }
180 
181 static const u8 llc_oui_ip[] = {
182 	0xaa,			/* DSAP: non-ISO */
183 	0xaa,			/* SSAP: non-ISO */
184 	0x03,			/* Ctrl: Unnumbered Information Command PDU */
185 	0x00,			/* OUI: EtherType */
186 	0x00, 0x00,
187 	0x08, 0x00
188 };				/* Ethertype IP (0800) */
189 
190 static const struct nla_policy atm_policy[TCA_ATM_MAX + 1] = {
191 	[TCA_ATM_FD]		= { .type = NLA_U32 },
192 	[TCA_ATM_EXCESS]	= { .type = NLA_U32 },
193 };
194 
atm_tc_change(struct Qdisc * sch,u32 classid,u32 parent,struct nlattr ** tca,unsigned long * arg,struct netlink_ext_ack * extack)195 static int atm_tc_change(struct Qdisc *sch, u32 classid, u32 parent,
196 			 struct nlattr **tca, unsigned long *arg,
197 			 struct netlink_ext_ack *extack)
198 {
199 	struct atm_qdisc_data *p = qdisc_priv(sch);
200 	struct atm_flow_data *flow = (struct atm_flow_data *)*arg;
201 	struct atm_flow_data *excess = NULL;
202 	struct nlattr *opt = tca[TCA_OPTIONS];
203 	struct nlattr *tb[TCA_ATM_MAX + 1];
204 	struct socket *sock;
205 	int fd, error, hdr_len;
206 	void *hdr;
207 
208 	pr_debug("atm_tc_change(sch %p,[qdisc %p],classid %x,parent %x,"
209 		"flow %p,opt %p)\n", sch, p, classid, parent, flow, opt);
210 	/*
211 	 * The concept of parents doesn't apply for this qdisc.
212 	 */
213 	if (parent && parent != TC_H_ROOT && parent != sch->handle)
214 		return -EINVAL;
215 	/*
216 	 * ATM classes cannot be changed. In order to change properties of the
217 	 * ATM connection, that socket needs to be modified directly (via the
218 	 * native ATM API. In order to send a flow to a different VC, the old
219 	 * class needs to be removed and a new one added. (This may be changed
220 	 * later.)
221 	 */
222 	if (flow)
223 		return -EBUSY;
224 	if (opt == NULL)
225 		return -EINVAL;
226 
227 	error = nla_parse_nested_deprecated(tb, TCA_ATM_MAX, opt, atm_policy,
228 					    NULL);
229 	if (error < 0)
230 		return error;
231 
232 	if (!tb[TCA_ATM_FD])
233 		return -EINVAL;
234 	fd = nla_get_u32(tb[TCA_ATM_FD]);
235 	pr_debug("atm_tc_change: fd %d\n", fd);
236 	if (tb[TCA_ATM_HDR]) {
237 		hdr_len = nla_len(tb[TCA_ATM_HDR]);
238 		hdr = nla_data(tb[TCA_ATM_HDR]);
239 	} else {
240 		hdr_len = RFC1483LLC_LEN;
241 		hdr = NULL;	/* default LLC/SNAP for IP */
242 	}
243 	if (!tb[TCA_ATM_EXCESS])
244 		excess = NULL;
245 	else {
246 		excess = (struct atm_flow_data *)
247 			atm_tc_find(sch, nla_get_u32(tb[TCA_ATM_EXCESS]));
248 		if (!excess)
249 			return -ENOENT;
250 	}
251 	pr_debug("atm_tc_change: type %d, payload %d, hdr_len %d\n",
252 		 opt->nla_type, nla_len(opt), hdr_len);
253 	sock = sockfd_lookup(fd, &error);
254 	if (!sock)
255 		return error;	/* f_count++ */
256 	pr_debug("atm_tc_change: f_count %ld\n", file_count(sock->file));
257 	if (sock->ops->family != PF_ATMSVC && sock->ops->family != PF_ATMPVC) {
258 		error = -EPROTOTYPE;
259 		goto err_out;
260 	}
261 	/* @@@ should check if the socket is really operational or we'll crash
262 	   on vcc->send */
263 	if (classid) {
264 		if (TC_H_MAJ(classid ^ sch->handle)) {
265 			pr_debug("atm_tc_change: classid mismatch\n");
266 			error = -EINVAL;
267 			goto err_out;
268 		}
269 	} else {
270 		int i;
271 		unsigned long cl;
272 
273 		for (i = 1; i < 0x8000; i++) {
274 			classid = TC_H_MAKE(sch->handle, 0x8000 | i);
275 			cl = atm_tc_find(sch, classid);
276 			if (!cl)
277 				break;
278 		}
279 	}
280 	pr_debug("atm_tc_change: new id %x\n", classid);
281 	flow = kzalloc(sizeof(struct atm_flow_data) + hdr_len, GFP_KERNEL);
282 	pr_debug("atm_tc_change: flow %p\n", flow);
283 	if (!flow) {
284 		error = -ENOBUFS;
285 		goto err_out;
286 	}
287 
288 	error = tcf_block_get(&flow->block, &flow->filter_list, sch,
289 			      extack);
290 	if (error) {
291 		kfree(flow);
292 		goto err_out;
293 	}
294 
295 	flow->q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, classid,
296 				    extack);
297 	if (!flow->q)
298 		flow->q = &noop_qdisc;
299 	pr_debug("atm_tc_change: qdisc %p\n", flow->q);
300 	flow->sock = sock;
301 	flow->vcc = ATM_SD(sock);	/* speedup */
302 	flow->vcc->user_back = flow;
303 	pr_debug("atm_tc_change: vcc %p\n", flow->vcc);
304 	flow->old_pop = flow->vcc->pop;
305 	flow->parent = p;
306 	flow->vcc->pop = sch_atm_pop;
307 	flow->common.classid = classid;
308 	flow->ref = 1;
309 	flow->excess = excess;
310 	list_add(&flow->list, &p->link.list);
311 	flow->hdr_len = hdr_len;
312 	if (hdr)
313 		memcpy(flow->hdr, hdr, hdr_len);
314 	else
315 		memcpy(flow->hdr, llc_oui_ip, sizeof(llc_oui_ip));
316 	*arg = (unsigned long)flow;
317 	return 0;
318 err_out:
319 	sockfd_put(sock);
320 	return error;
321 }
322 
atm_tc_delete(struct Qdisc * sch,unsigned long arg,struct netlink_ext_ack * extack)323 static int atm_tc_delete(struct Qdisc *sch, unsigned long arg,
324 			 struct netlink_ext_ack *extack)
325 {
326 	struct atm_qdisc_data *p = qdisc_priv(sch);
327 	struct atm_flow_data *flow = (struct atm_flow_data *)arg;
328 
329 	pr_debug("atm_tc_delete(sch %p,[qdisc %p],flow %p)\n", sch, p, flow);
330 	if (list_empty(&flow->list))
331 		return -EINVAL;
332 	if (rcu_access_pointer(flow->filter_list) || flow == &p->link)
333 		return -EBUSY;
334 	/*
335 	 * Reference count must be 2: one for "keepalive" (set at class
336 	 * creation), and one for the reference held when calling delete.
337 	 */
338 	if (flow->ref < 2) {
339 		pr_err("atm_tc_delete: flow->ref == %d\n", flow->ref);
340 		return -EINVAL;
341 	}
342 	if (flow->ref > 2)
343 		return -EBUSY;	/* catch references via excess, etc. */
344 	atm_tc_put(sch, arg);
345 	return 0;
346 }
347 
atm_tc_walk(struct Qdisc * sch,struct qdisc_walker * walker)348 static void atm_tc_walk(struct Qdisc *sch, struct qdisc_walker *walker)
349 {
350 	struct atm_qdisc_data *p = qdisc_priv(sch);
351 	struct atm_flow_data *flow;
352 
353 	pr_debug("atm_tc_walk(sch %p,[qdisc %p],walker %p)\n", sch, p, walker);
354 	if (walker->stop)
355 		return;
356 	list_for_each_entry(flow, &p->flows, list) {
357 		if (!tc_qdisc_stats_dump(sch, (unsigned long)flow, walker))
358 			break;
359 	}
360 }
361 
atm_tc_tcf_block(struct Qdisc * sch,unsigned long cl,struct netlink_ext_ack * extack)362 static struct tcf_block *atm_tc_tcf_block(struct Qdisc *sch, unsigned long cl,
363 					  struct netlink_ext_ack *extack)
364 {
365 	struct atm_qdisc_data *p = qdisc_priv(sch);
366 	struct atm_flow_data *flow = (struct atm_flow_data *)cl;
367 
368 	pr_debug("atm_tc_find_tcf(sch %p,[qdisc %p],flow %p)\n", sch, p, flow);
369 	return flow ? flow->block : p->link.block;
370 }
371 
372 /* --------------------------- Qdisc operations ---------------------------- */
373 
atm_tc_enqueue(struct sk_buff * skb,struct Qdisc * sch,struct sk_buff ** to_free)374 static int atm_tc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
375 			  struct sk_buff **to_free)
376 {
377 	struct atm_qdisc_data *p = qdisc_priv(sch);
378 	struct atm_flow_data *flow;
379 	struct tcf_result res;
380 	int result;
381 	int ret = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
382 
383 	pr_debug("atm_tc_enqueue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);
384 	result = TC_ACT_OK;	/* be nice to gcc */
385 	flow = NULL;
386 	if (TC_H_MAJ(skb->priority) != sch->handle ||
387 	    !(flow = (struct atm_flow_data *)atm_tc_find(sch, skb->priority))) {
388 		struct tcf_proto *fl;
389 
390 		list_for_each_entry(flow, &p->flows, list) {
391 			fl = rcu_dereference_bh(flow->filter_list);
392 			if (fl) {
393 				result = tcf_classify(skb, NULL, fl, &res, true);
394 				if (result < 0)
395 					continue;
396 				flow = (struct atm_flow_data *)res.class;
397 				if (!flow)
398 					flow = lookup_flow(sch, res.classid);
399 				goto done;
400 			}
401 		}
402 		flow = NULL;
403 done:
404 		;
405 	}
406 	if (!flow) {
407 		flow = &p->link;
408 	} else {
409 		if (flow->vcc)
410 			ATM_SKB(skb)->atm_options = flow->vcc->atm_options;
411 		/*@@@ looks good ... but it's not supposed to work :-) */
412 #ifdef CONFIG_NET_CLS_ACT
413 		switch (result) {
414 		case TC_ACT_QUEUED:
415 		case TC_ACT_STOLEN:
416 		case TC_ACT_TRAP:
417 			__qdisc_drop(skb, to_free);
418 			return NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
419 		case TC_ACT_SHOT:
420 			__qdisc_drop(skb, to_free);
421 			goto drop;
422 		case TC_ACT_RECLASSIFY:
423 			if (flow->excess)
424 				flow = flow->excess;
425 			else
426 				ATM_SKB(skb)->atm_options |= ATM_ATMOPT_CLP;
427 			break;
428 		}
429 #endif
430 	}
431 
432 	ret = qdisc_enqueue(skb, flow->q, to_free);
433 	if (ret != NET_XMIT_SUCCESS) {
434 drop: __maybe_unused
435 		if (net_xmit_drop_count(ret)) {
436 			qdisc_qstats_drop(sch);
437 			if (flow)
438 				flow->qstats.drops++;
439 		}
440 		return ret;
441 	}
442 	/*
443 	 * Okay, this may seem weird. We pretend we've dropped the packet if
444 	 * it goes via ATM. The reason for this is that the outer qdisc
445 	 * expects to be able to q->dequeue the packet later on if we return
446 	 * success at this place. Also, sch->q.qdisc needs to reflect whether
447 	 * there is a packet egligible for dequeuing or not. Note that the
448 	 * statistics of the outer qdisc are necessarily wrong because of all
449 	 * this. There's currently no correct solution for this.
450 	 */
451 	if (flow == &p->link) {
452 		sch->q.qlen++;
453 		return NET_XMIT_SUCCESS;
454 	}
455 	tasklet_schedule(&p->task);
456 	return NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
457 }
458 
459 /*
460  * Dequeue packets and send them over ATM. Note that we quite deliberately
461  * avoid checking net_device's flow control here, simply because sch_atm
462  * uses its own channels, which have nothing to do with any CLIP/LANE/or
463  * non-ATM interfaces.
464  */
465 
sch_atm_dequeue(struct tasklet_struct * t)466 static void sch_atm_dequeue(struct tasklet_struct *t)
467 {
468 	struct atm_qdisc_data *p = from_tasklet(p, t, task);
469 	struct Qdisc *sch = qdisc_from_priv(p);
470 	struct atm_flow_data *flow;
471 	struct sk_buff *skb;
472 
473 	pr_debug("sch_atm_dequeue(sch %p,[qdisc %p])\n", sch, p);
474 	list_for_each_entry(flow, &p->flows, list) {
475 		if (flow == &p->link)
476 			continue;
477 		/*
478 		 * If traffic is properly shaped, this won't generate nasty
479 		 * little bursts. Otherwise, it may ... (but that's okay)
480 		 */
481 		while ((skb = flow->q->ops->peek(flow->q))) {
482 			if (!atm_may_send(flow->vcc, skb->truesize))
483 				break;
484 
485 			skb = qdisc_dequeue_peeked(flow->q);
486 			if (unlikely(!skb))
487 				break;
488 
489 			qdisc_bstats_update(sch, skb);
490 			bstats_update(&flow->bstats, skb);
491 			pr_debug("atm_tc_dequeue: sending on class %p\n", flow);
492 			/* remove any LL header somebody else has attached */
493 			skb_pull(skb, skb_network_offset(skb));
494 			if (skb_headroom(skb) < flow->hdr_len) {
495 				struct sk_buff *new;
496 
497 				new = skb_realloc_headroom(skb, flow->hdr_len);
498 				dev_kfree_skb(skb);
499 				if (!new)
500 					continue;
501 				skb = new;
502 			}
503 			pr_debug("sch_atm_dequeue: ip %p, data %p\n",
504 				 skb_network_header(skb), skb->data);
505 			ATM_SKB(skb)->vcc = flow->vcc;
506 			memcpy(skb_push(skb, flow->hdr_len), flow->hdr,
507 			       flow->hdr_len);
508 			refcount_add(skb->truesize,
509 				   &sk_atm(flow->vcc)->sk_wmem_alloc);
510 			/* atm.atm_options are already set by atm_tc_enqueue */
511 			flow->vcc->send(flow->vcc, skb);
512 		}
513 	}
514 }
515 
atm_tc_dequeue(struct Qdisc * sch)516 static struct sk_buff *atm_tc_dequeue(struct Qdisc *sch)
517 {
518 	struct atm_qdisc_data *p = qdisc_priv(sch);
519 	struct sk_buff *skb;
520 
521 	pr_debug("atm_tc_dequeue(sch %p,[qdisc %p])\n", sch, p);
522 	tasklet_schedule(&p->task);
523 	skb = qdisc_dequeue_peeked(p->link.q);
524 	if (skb)
525 		sch->q.qlen--;
526 	return skb;
527 }
528 
atm_tc_peek(struct Qdisc * sch)529 static struct sk_buff *atm_tc_peek(struct Qdisc *sch)
530 {
531 	struct atm_qdisc_data *p = qdisc_priv(sch);
532 
533 	pr_debug("atm_tc_peek(sch %p,[qdisc %p])\n", sch, p);
534 
535 	return p->link.q->ops->peek(p->link.q);
536 }
537 
atm_tc_init(struct Qdisc * sch,struct nlattr * opt,struct netlink_ext_ack * extack)538 static int atm_tc_init(struct Qdisc *sch, struct nlattr *opt,
539 		       struct netlink_ext_ack *extack)
540 {
541 	struct atm_qdisc_data *p = qdisc_priv(sch);
542 	int err;
543 
544 	pr_debug("atm_tc_init(sch %p,[qdisc %p],opt %p)\n", sch, p, opt);
545 	INIT_LIST_HEAD(&p->flows);
546 	INIT_LIST_HEAD(&p->link.list);
547 	gnet_stats_basic_sync_init(&p->link.bstats);
548 	list_add(&p->link.list, &p->flows);
549 	p->link.q = qdisc_create_dflt(sch->dev_queue,
550 				      &pfifo_qdisc_ops, sch->handle, extack);
551 	if (!p->link.q)
552 		p->link.q = &noop_qdisc;
553 	pr_debug("atm_tc_init: link (%p) qdisc %p\n", &p->link, p->link.q);
554 	p->link.vcc = NULL;
555 	p->link.sock = NULL;
556 	p->link.common.classid = sch->handle;
557 	p->link.ref = 1;
558 
559 	err = tcf_block_get(&p->link.block, &p->link.filter_list, sch,
560 			    extack);
561 	if (err)
562 		return err;
563 
564 	tasklet_setup(&p->task, sch_atm_dequeue);
565 	return 0;
566 }
567 
atm_tc_reset(struct Qdisc * sch)568 static void atm_tc_reset(struct Qdisc *sch)
569 {
570 	struct atm_qdisc_data *p = qdisc_priv(sch);
571 	struct atm_flow_data *flow;
572 
573 	pr_debug("atm_tc_reset(sch %p,[qdisc %p])\n", sch, p);
574 	list_for_each_entry(flow, &p->flows, list)
575 		qdisc_reset(flow->q);
576 }
577 
atm_tc_destroy(struct Qdisc * sch)578 static void atm_tc_destroy(struct Qdisc *sch)
579 {
580 	struct atm_qdisc_data *p = qdisc_priv(sch);
581 	struct atm_flow_data *flow, *tmp;
582 
583 	pr_debug("atm_tc_destroy(sch %p,[qdisc %p])\n", sch, p);
584 	list_for_each_entry(flow, &p->flows, list) {
585 		tcf_block_put(flow->block);
586 		flow->block = NULL;
587 	}
588 
589 	list_for_each_entry_safe(flow, tmp, &p->flows, list) {
590 		if (flow->ref > 1)
591 			pr_err("atm_destroy: %p->ref = %d\n", flow, flow->ref);
592 		atm_tc_put(sch, (unsigned long)flow);
593 	}
594 	tasklet_kill(&p->task);
595 }
596 
atm_tc_dump_class(struct Qdisc * sch,unsigned long cl,struct sk_buff * skb,struct tcmsg * tcm)597 static int atm_tc_dump_class(struct Qdisc *sch, unsigned long cl,
598 			     struct sk_buff *skb, struct tcmsg *tcm)
599 {
600 	struct atm_qdisc_data *p = qdisc_priv(sch);
601 	struct atm_flow_data *flow = (struct atm_flow_data *)cl;
602 	struct nlattr *nest;
603 
604 	pr_debug("atm_tc_dump_class(sch %p,[qdisc %p],flow %p,skb %p,tcm %p)\n",
605 		sch, p, flow, skb, tcm);
606 	if (list_empty(&flow->list))
607 		return -EINVAL;
608 	tcm->tcm_handle = flow->common.classid;
609 	tcm->tcm_info = flow->q->handle;
610 
611 	nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
612 	if (nest == NULL)
613 		goto nla_put_failure;
614 
615 	if (nla_put(skb, TCA_ATM_HDR, flow->hdr_len, flow->hdr))
616 		goto nla_put_failure;
617 	if (flow->vcc) {
618 		struct sockaddr_atmpvc pvc;
619 		int state;
620 
621 		memset(&pvc, 0, sizeof(pvc));
622 		pvc.sap_family = AF_ATMPVC;
623 		pvc.sap_addr.itf = flow->vcc->dev ? flow->vcc->dev->number : -1;
624 		pvc.sap_addr.vpi = flow->vcc->vpi;
625 		pvc.sap_addr.vci = flow->vcc->vci;
626 		if (nla_put(skb, TCA_ATM_ADDR, sizeof(pvc), &pvc))
627 			goto nla_put_failure;
628 		state = ATM_VF2VS(flow->vcc->flags);
629 		if (nla_put_u32(skb, TCA_ATM_STATE, state))
630 			goto nla_put_failure;
631 	}
632 	if (flow->excess) {
633 		if (nla_put_u32(skb, TCA_ATM_EXCESS, flow->common.classid))
634 			goto nla_put_failure;
635 	} else {
636 		if (nla_put_u32(skb, TCA_ATM_EXCESS, 0))
637 			goto nla_put_failure;
638 	}
639 	return nla_nest_end(skb, nest);
640 
641 nla_put_failure:
642 	nla_nest_cancel(skb, nest);
643 	return -1;
644 }
645 static int
atm_tc_dump_class_stats(struct Qdisc * sch,unsigned long arg,struct gnet_dump * d)646 atm_tc_dump_class_stats(struct Qdisc *sch, unsigned long arg,
647 			struct gnet_dump *d)
648 {
649 	struct atm_flow_data *flow = (struct atm_flow_data *)arg;
650 
651 	if (gnet_stats_copy_basic(d, NULL, &flow->bstats, true) < 0 ||
652 	    gnet_stats_copy_queue(d, NULL, &flow->qstats, flow->q->q.qlen) < 0)
653 		return -1;
654 
655 	return 0;
656 }
657 
atm_tc_dump(struct Qdisc * sch,struct sk_buff * skb)658 static int atm_tc_dump(struct Qdisc *sch, struct sk_buff *skb)
659 {
660 	return 0;
661 }
662 
663 static const struct Qdisc_class_ops atm_class_ops = {
664 	.graft		= atm_tc_graft,
665 	.leaf		= atm_tc_leaf,
666 	.find		= atm_tc_find,
667 	.change		= atm_tc_change,
668 	.delete		= atm_tc_delete,
669 	.walk		= atm_tc_walk,
670 	.tcf_block	= atm_tc_tcf_block,
671 	.bind_tcf	= atm_tc_bind_filter,
672 	.unbind_tcf	= atm_tc_put,
673 	.dump		= atm_tc_dump_class,
674 	.dump_stats	= atm_tc_dump_class_stats,
675 };
676 
677 static struct Qdisc_ops atm_qdisc_ops __read_mostly = {
678 	.cl_ops		= &atm_class_ops,
679 	.id		= "atm",
680 	.priv_size	= sizeof(struct atm_qdisc_data),
681 	.enqueue	= atm_tc_enqueue,
682 	.dequeue	= atm_tc_dequeue,
683 	.peek		= atm_tc_peek,
684 	.init		= atm_tc_init,
685 	.reset		= atm_tc_reset,
686 	.destroy	= atm_tc_destroy,
687 	.dump		= atm_tc_dump,
688 	.owner		= THIS_MODULE,
689 };
690 
atm_init(void)691 static int __init atm_init(void)
692 {
693 	return register_qdisc(&atm_qdisc_ops);
694 }
695 
atm_exit(void)696 static void __exit atm_exit(void)
697 {
698 	unregister_qdisc(&atm_qdisc_ops);
699 }
700 
701 module_init(atm_init)
702 module_exit(atm_exit)
703 MODULE_LICENSE("GPL");
704