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 				if (result == TC_ACT_SHOT)
397 					goto done;
398 
399 				flow = (struct atm_flow_data *)res.class;
400 				if (!flow)
401 					flow = lookup_flow(sch, res.classid);
402 				goto drop;
403 			}
404 		}
405 		flow = NULL;
406 done:
407 		;
408 	}
409 	if (!flow) {
410 		flow = &p->link;
411 	} else {
412 		if (flow->vcc)
413 			ATM_SKB(skb)->atm_options = flow->vcc->atm_options;
414 		/*@@@ looks good ... but it's not supposed to work :-) */
415 #ifdef CONFIG_NET_CLS_ACT
416 		switch (result) {
417 		case TC_ACT_QUEUED:
418 		case TC_ACT_STOLEN:
419 		case TC_ACT_TRAP:
420 			__qdisc_drop(skb, to_free);
421 			return NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
422 		case TC_ACT_SHOT:
423 			__qdisc_drop(skb, to_free);
424 			goto drop;
425 		case TC_ACT_RECLASSIFY:
426 			if (flow->excess)
427 				flow = flow->excess;
428 			else
429 				ATM_SKB(skb)->atm_options |= ATM_ATMOPT_CLP;
430 			break;
431 		}
432 #endif
433 	}
434 
435 	ret = qdisc_enqueue(skb, flow->q, to_free);
436 	if (ret != NET_XMIT_SUCCESS) {
437 drop: __maybe_unused
438 		if (net_xmit_drop_count(ret)) {
439 			qdisc_qstats_drop(sch);
440 			if (flow)
441 				flow->qstats.drops++;
442 		}
443 		return ret;
444 	}
445 	/*
446 	 * Okay, this may seem weird. We pretend we've dropped the packet if
447 	 * it goes via ATM. The reason for this is that the outer qdisc
448 	 * expects to be able to q->dequeue the packet later on if we return
449 	 * success at this place. Also, sch->q.qdisc needs to reflect whether
450 	 * there is a packet egligible for dequeuing or not. Note that the
451 	 * statistics of the outer qdisc are necessarily wrong because of all
452 	 * this. There's currently no correct solution for this.
453 	 */
454 	if (flow == &p->link) {
455 		sch->q.qlen++;
456 		return NET_XMIT_SUCCESS;
457 	}
458 	tasklet_schedule(&p->task);
459 	return NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
460 }
461 
462 /*
463  * Dequeue packets and send them over ATM. Note that we quite deliberately
464  * avoid checking net_device's flow control here, simply because sch_atm
465  * uses its own channels, which have nothing to do with any CLIP/LANE/or
466  * non-ATM interfaces.
467  */
468 
sch_atm_dequeue(struct tasklet_struct * t)469 static void sch_atm_dequeue(struct tasklet_struct *t)
470 {
471 	struct atm_qdisc_data *p = from_tasklet(p, t, task);
472 	struct Qdisc *sch = qdisc_from_priv(p);
473 	struct atm_flow_data *flow;
474 	struct sk_buff *skb;
475 
476 	pr_debug("sch_atm_dequeue(sch %p,[qdisc %p])\n", sch, p);
477 	list_for_each_entry(flow, &p->flows, list) {
478 		if (flow == &p->link)
479 			continue;
480 		/*
481 		 * If traffic is properly shaped, this won't generate nasty
482 		 * little bursts. Otherwise, it may ... (but that's okay)
483 		 */
484 		while ((skb = flow->q->ops->peek(flow->q))) {
485 			if (!atm_may_send(flow->vcc, skb->truesize))
486 				break;
487 
488 			skb = qdisc_dequeue_peeked(flow->q);
489 			if (unlikely(!skb))
490 				break;
491 
492 			qdisc_bstats_update(sch, skb);
493 			bstats_update(&flow->bstats, skb);
494 			pr_debug("atm_tc_dequeue: sending on class %p\n", flow);
495 			/* remove any LL header somebody else has attached */
496 			skb_pull(skb, skb_network_offset(skb));
497 			if (skb_headroom(skb) < flow->hdr_len) {
498 				struct sk_buff *new;
499 
500 				new = skb_realloc_headroom(skb, flow->hdr_len);
501 				dev_kfree_skb(skb);
502 				if (!new)
503 					continue;
504 				skb = new;
505 			}
506 			pr_debug("sch_atm_dequeue: ip %p, data %p\n",
507 				 skb_network_header(skb), skb->data);
508 			ATM_SKB(skb)->vcc = flow->vcc;
509 			memcpy(skb_push(skb, flow->hdr_len), flow->hdr,
510 			       flow->hdr_len);
511 			refcount_add(skb->truesize,
512 				   &sk_atm(flow->vcc)->sk_wmem_alloc);
513 			/* atm.atm_options are already set by atm_tc_enqueue */
514 			flow->vcc->send(flow->vcc, skb);
515 		}
516 	}
517 }
518 
atm_tc_dequeue(struct Qdisc * sch)519 static struct sk_buff *atm_tc_dequeue(struct Qdisc *sch)
520 {
521 	struct atm_qdisc_data *p = qdisc_priv(sch);
522 	struct sk_buff *skb;
523 
524 	pr_debug("atm_tc_dequeue(sch %p,[qdisc %p])\n", sch, p);
525 	tasklet_schedule(&p->task);
526 	skb = qdisc_dequeue_peeked(p->link.q);
527 	if (skb)
528 		sch->q.qlen--;
529 	return skb;
530 }
531 
atm_tc_peek(struct Qdisc * sch)532 static struct sk_buff *atm_tc_peek(struct Qdisc *sch)
533 {
534 	struct atm_qdisc_data *p = qdisc_priv(sch);
535 
536 	pr_debug("atm_tc_peek(sch %p,[qdisc %p])\n", sch, p);
537 
538 	return p->link.q->ops->peek(p->link.q);
539 }
540 
atm_tc_init(struct Qdisc * sch,struct nlattr * opt,struct netlink_ext_ack * extack)541 static int atm_tc_init(struct Qdisc *sch, struct nlattr *opt,
542 		       struct netlink_ext_ack *extack)
543 {
544 	struct atm_qdisc_data *p = qdisc_priv(sch);
545 	int err;
546 
547 	pr_debug("atm_tc_init(sch %p,[qdisc %p],opt %p)\n", sch, p, opt);
548 	INIT_LIST_HEAD(&p->flows);
549 	INIT_LIST_HEAD(&p->link.list);
550 	gnet_stats_basic_sync_init(&p->link.bstats);
551 	list_add(&p->link.list, &p->flows);
552 	p->link.q = qdisc_create_dflt(sch->dev_queue,
553 				      &pfifo_qdisc_ops, sch->handle, extack);
554 	if (!p->link.q)
555 		p->link.q = &noop_qdisc;
556 	pr_debug("atm_tc_init: link (%p) qdisc %p\n", &p->link, p->link.q);
557 	p->link.vcc = NULL;
558 	p->link.sock = NULL;
559 	p->link.common.classid = sch->handle;
560 	p->link.ref = 1;
561 
562 	err = tcf_block_get(&p->link.block, &p->link.filter_list, sch,
563 			    extack);
564 	if (err)
565 		return err;
566 
567 	tasklet_setup(&p->task, sch_atm_dequeue);
568 	return 0;
569 }
570 
atm_tc_reset(struct Qdisc * sch)571 static void atm_tc_reset(struct Qdisc *sch)
572 {
573 	struct atm_qdisc_data *p = qdisc_priv(sch);
574 	struct atm_flow_data *flow;
575 
576 	pr_debug("atm_tc_reset(sch %p,[qdisc %p])\n", sch, p);
577 	list_for_each_entry(flow, &p->flows, list)
578 		qdisc_reset(flow->q);
579 }
580 
atm_tc_destroy(struct Qdisc * sch)581 static void atm_tc_destroy(struct Qdisc *sch)
582 {
583 	struct atm_qdisc_data *p = qdisc_priv(sch);
584 	struct atm_flow_data *flow, *tmp;
585 
586 	pr_debug("atm_tc_destroy(sch %p,[qdisc %p])\n", sch, p);
587 	list_for_each_entry(flow, &p->flows, list) {
588 		tcf_block_put(flow->block);
589 		flow->block = NULL;
590 	}
591 
592 	list_for_each_entry_safe(flow, tmp, &p->flows, list) {
593 		if (flow->ref > 1)
594 			pr_err("atm_destroy: %p->ref = %d\n", flow, flow->ref);
595 		atm_tc_put(sch, (unsigned long)flow);
596 	}
597 	tasklet_kill(&p->task);
598 }
599 
atm_tc_dump_class(struct Qdisc * sch,unsigned long cl,struct sk_buff * skb,struct tcmsg * tcm)600 static int atm_tc_dump_class(struct Qdisc *sch, unsigned long cl,
601 			     struct sk_buff *skb, struct tcmsg *tcm)
602 {
603 	struct atm_qdisc_data *p = qdisc_priv(sch);
604 	struct atm_flow_data *flow = (struct atm_flow_data *)cl;
605 	struct nlattr *nest;
606 
607 	pr_debug("atm_tc_dump_class(sch %p,[qdisc %p],flow %p,skb %p,tcm %p)\n",
608 		sch, p, flow, skb, tcm);
609 	if (list_empty(&flow->list))
610 		return -EINVAL;
611 	tcm->tcm_handle = flow->common.classid;
612 	tcm->tcm_info = flow->q->handle;
613 
614 	nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
615 	if (nest == NULL)
616 		goto nla_put_failure;
617 
618 	if (nla_put(skb, TCA_ATM_HDR, flow->hdr_len, flow->hdr))
619 		goto nla_put_failure;
620 	if (flow->vcc) {
621 		struct sockaddr_atmpvc pvc;
622 		int state;
623 
624 		memset(&pvc, 0, sizeof(pvc));
625 		pvc.sap_family = AF_ATMPVC;
626 		pvc.sap_addr.itf = flow->vcc->dev ? flow->vcc->dev->number : -1;
627 		pvc.sap_addr.vpi = flow->vcc->vpi;
628 		pvc.sap_addr.vci = flow->vcc->vci;
629 		if (nla_put(skb, TCA_ATM_ADDR, sizeof(pvc), &pvc))
630 			goto nla_put_failure;
631 		state = ATM_VF2VS(flow->vcc->flags);
632 		if (nla_put_u32(skb, TCA_ATM_STATE, state))
633 			goto nla_put_failure;
634 	}
635 	if (flow->excess) {
636 		if (nla_put_u32(skb, TCA_ATM_EXCESS, flow->common.classid))
637 			goto nla_put_failure;
638 	} else {
639 		if (nla_put_u32(skb, TCA_ATM_EXCESS, 0))
640 			goto nla_put_failure;
641 	}
642 	return nla_nest_end(skb, nest);
643 
644 nla_put_failure:
645 	nla_nest_cancel(skb, nest);
646 	return -1;
647 }
648 static int
atm_tc_dump_class_stats(struct Qdisc * sch,unsigned long arg,struct gnet_dump * d)649 atm_tc_dump_class_stats(struct Qdisc *sch, unsigned long arg,
650 			struct gnet_dump *d)
651 {
652 	struct atm_flow_data *flow = (struct atm_flow_data *)arg;
653 
654 	if (gnet_stats_copy_basic(d, NULL, &flow->bstats, true) < 0 ||
655 	    gnet_stats_copy_queue(d, NULL, &flow->qstats, flow->q->q.qlen) < 0)
656 		return -1;
657 
658 	return 0;
659 }
660 
atm_tc_dump(struct Qdisc * sch,struct sk_buff * skb)661 static int atm_tc_dump(struct Qdisc *sch, struct sk_buff *skb)
662 {
663 	return 0;
664 }
665 
666 static const struct Qdisc_class_ops atm_class_ops = {
667 	.graft		= atm_tc_graft,
668 	.leaf		= atm_tc_leaf,
669 	.find		= atm_tc_find,
670 	.change		= atm_tc_change,
671 	.delete		= atm_tc_delete,
672 	.walk		= atm_tc_walk,
673 	.tcf_block	= atm_tc_tcf_block,
674 	.bind_tcf	= atm_tc_bind_filter,
675 	.unbind_tcf	= atm_tc_put,
676 	.dump		= atm_tc_dump_class,
677 	.dump_stats	= atm_tc_dump_class_stats,
678 };
679 
680 static struct Qdisc_ops atm_qdisc_ops __read_mostly = {
681 	.cl_ops		= &atm_class_ops,
682 	.id		= "atm",
683 	.priv_size	= sizeof(struct atm_qdisc_data),
684 	.enqueue	= atm_tc_enqueue,
685 	.dequeue	= atm_tc_dequeue,
686 	.peek		= atm_tc_peek,
687 	.init		= atm_tc_init,
688 	.reset		= atm_tc_reset,
689 	.destroy	= atm_tc_destroy,
690 	.dump		= atm_tc_dump,
691 	.owner		= THIS_MODULE,
692 };
693 
atm_init(void)694 static int __init atm_init(void)
695 {
696 	return register_qdisc(&atm_qdisc_ops);
697 }
698 
atm_exit(void)699 static void __exit atm_exit(void)
700 {
701 	unregister_qdisc(&atm_qdisc_ops);
702 }
703 
704 module_init(atm_init)
705 module_exit(atm_exit)
706 MODULE_LICENSE("GPL");
707