cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
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sch_atm.c (19992B)


      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
     44struct 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
     64struct 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
     73static 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
     85static 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
    105static 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
    113static 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
    124static 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 */
    143static 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
    172static 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
    181static 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
    190static 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
    195static 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;
    318err_out:
    319	sockfd_put(sock);
    320	return error;
    321}
    322
    323static 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
    348static 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 (walker->count >= walker->skip &&
    358		    walker->fn(sch, (unsigned long)flow, walker) < 0) {
    359			walker->stop = 1;
    360			break;
    361		}
    362		walker->count++;
    363	}
    364}
    365
    366static struct tcf_block *atm_tc_tcf_block(struct Qdisc *sch, unsigned long cl,
    367					  struct netlink_ext_ack *extack)
    368{
    369	struct atm_qdisc_data *p = qdisc_priv(sch);
    370	struct atm_flow_data *flow = (struct atm_flow_data *)cl;
    371
    372	pr_debug("atm_tc_find_tcf(sch %p,[qdisc %p],flow %p)\n", sch, p, flow);
    373	return flow ? flow->block : p->link.block;
    374}
    375
    376/* --------------------------- Qdisc operations ---------------------------- */
    377
    378static int atm_tc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
    379			  struct sk_buff **to_free)
    380{
    381	struct atm_qdisc_data *p = qdisc_priv(sch);
    382	struct atm_flow_data *flow;
    383	struct tcf_result res;
    384	int result;
    385	int ret = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
    386
    387	pr_debug("atm_tc_enqueue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);
    388	result = TC_ACT_OK;	/* be nice to gcc */
    389	flow = NULL;
    390	if (TC_H_MAJ(skb->priority) != sch->handle ||
    391	    !(flow = (struct atm_flow_data *)atm_tc_find(sch, skb->priority))) {
    392		struct tcf_proto *fl;
    393
    394		list_for_each_entry(flow, &p->flows, list) {
    395			fl = rcu_dereference_bh(flow->filter_list);
    396			if (fl) {
    397				result = tcf_classify(skb, NULL, fl, &res, true);
    398				if (result < 0)
    399					continue;
    400				flow = (struct atm_flow_data *)res.class;
    401				if (!flow)
    402					flow = lookup_flow(sch, res.classid);
    403				goto done;
    404			}
    405		}
    406		flow = NULL;
    407done:
    408		;
    409	}
    410	if (!flow) {
    411		flow = &p->link;
    412	} else {
    413		if (flow->vcc)
    414			ATM_SKB(skb)->atm_options = flow->vcc->atm_options;
    415		/*@@@ looks good ... but it's not supposed to work :-) */
    416#ifdef CONFIG_NET_CLS_ACT
    417		switch (result) {
    418		case TC_ACT_QUEUED:
    419		case TC_ACT_STOLEN:
    420		case TC_ACT_TRAP:
    421			__qdisc_drop(skb, to_free);
    422			return NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
    423		case TC_ACT_SHOT:
    424			__qdisc_drop(skb, to_free);
    425			goto drop;
    426		case TC_ACT_RECLASSIFY:
    427			if (flow->excess)
    428				flow = flow->excess;
    429			else
    430				ATM_SKB(skb)->atm_options |= ATM_ATMOPT_CLP;
    431			break;
    432		}
    433#endif
    434	}
    435
    436	ret = qdisc_enqueue(skb, flow->q, to_free);
    437	if (ret != NET_XMIT_SUCCESS) {
    438drop: __maybe_unused
    439		if (net_xmit_drop_count(ret)) {
    440			qdisc_qstats_drop(sch);
    441			if (flow)
    442				flow->qstats.drops++;
    443		}
    444		return ret;
    445	}
    446	/*
    447	 * Okay, this may seem weird. We pretend we've dropped the packet if
    448	 * it goes via ATM. The reason for this is that the outer qdisc
    449	 * expects to be able to q->dequeue the packet later on if we return
    450	 * success at this place. Also, sch->q.qdisc needs to reflect whether
    451	 * there is a packet egligible for dequeuing or not. Note that the
    452	 * statistics of the outer qdisc are necessarily wrong because of all
    453	 * this. There's currently no correct solution for this.
    454	 */
    455	if (flow == &p->link) {
    456		sch->q.qlen++;
    457		return NET_XMIT_SUCCESS;
    458	}
    459	tasklet_schedule(&p->task);
    460	return NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
    461}
    462
    463/*
    464 * Dequeue packets and send them over ATM. Note that we quite deliberately
    465 * avoid checking net_device's flow control here, simply because sch_atm
    466 * uses its own channels, which have nothing to do with any CLIP/LANE/or
    467 * non-ATM interfaces.
    468 */
    469
    470static void sch_atm_dequeue(struct tasklet_struct *t)
    471{
    472	struct atm_qdisc_data *p = from_tasklet(p, t, task);
    473	struct Qdisc *sch = qdisc_from_priv(p);
    474	struct atm_flow_data *flow;
    475	struct sk_buff *skb;
    476
    477	pr_debug("sch_atm_dequeue(sch %p,[qdisc %p])\n", sch, p);
    478	list_for_each_entry(flow, &p->flows, list) {
    479		if (flow == &p->link)
    480			continue;
    481		/*
    482		 * If traffic is properly shaped, this won't generate nasty
    483		 * little bursts. Otherwise, it may ... (but that's okay)
    484		 */
    485		while ((skb = flow->q->ops->peek(flow->q))) {
    486			if (!atm_may_send(flow->vcc, skb->truesize))
    487				break;
    488
    489			skb = qdisc_dequeue_peeked(flow->q);
    490			if (unlikely(!skb))
    491				break;
    492
    493			qdisc_bstats_update(sch, skb);
    494			bstats_update(&flow->bstats, skb);
    495			pr_debug("atm_tc_dequeue: sending on class %p\n", flow);
    496			/* remove any LL header somebody else has attached */
    497			skb_pull(skb, skb_network_offset(skb));
    498			if (skb_headroom(skb) < flow->hdr_len) {
    499				struct sk_buff *new;
    500
    501				new = skb_realloc_headroom(skb, flow->hdr_len);
    502				dev_kfree_skb(skb);
    503				if (!new)
    504					continue;
    505				skb = new;
    506			}
    507			pr_debug("sch_atm_dequeue: ip %p, data %p\n",
    508				 skb_network_header(skb), skb->data);
    509			ATM_SKB(skb)->vcc = flow->vcc;
    510			memcpy(skb_push(skb, flow->hdr_len), flow->hdr,
    511			       flow->hdr_len);
    512			refcount_add(skb->truesize,
    513				   &sk_atm(flow->vcc)->sk_wmem_alloc);
    514			/* atm.atm_options are already set by atm_tc_enqueue */
    515			flow->vcc->send(flow->vcc, skb);
    516		}
    517	}
    518}
    519
    520static struct sk_buff *atm_tc_dequeue(struct Qdisc *sch)
    521{
    522	struct atm_qdisc_data *p = qdisc_priv(sch);
    523	struct sk_buff *skb;
    524
    525	pr_debug("atm_tc_dequeue(sch %p,[qdisc %p])\n", sch, p);
    526	tasklet_schedule(&p->task);
    527	skb = qdisc_dequeue_peeked(p->link.q);
    528	if (skb)
    529		sch->q.qlen--;
    530	return skb;
    531}
    532
    533static struct sk_buff *atm_tc_peek(struct Qdisc *sch)
    534{
    535	struct atm_qdisc_data *p = qdisc_priv(sch);
    536
    537	pr_debug("atm_tc_peek(sch %p,[qdisc %p])\n", sch, p);
    538
    539	return p->link.q->ops->peek(p->link.q);
    540}
    541
    542static int atm_tc_init(struct Qdisc *sch, struct nlattr *opt,
    543		       struct netlink_ext_ack *extack)
    544{
    545	struct atm_qdisc_data *p = qdisc_priv(sch);
    546	int err;
    547
    548	pr_debug("atm_tc_init(sch %p,[qdisc %p],opt %p)\n", sch, p, opt);
    549	INIT_LIST_HEAD(&p->flows);
    550	INIT_LIST_HEAD(&p->link.list);
    551	gnet_stats_basic_sync_init(&p->link.bstats);
    552	list_add(&p->link.list, &p->flows);
    553	p->link.q = qdisc_create_dflt(sch->dev_queue,
    554				      &pfifo_qdisc_ops, sch->handle, extack);
    555	if (!p->link.q)
    556		p->link.q = &noop_qdisc;
    557	pr_debug("atm_tc_init: link (%p) qdisc %p\n", &p->link, p->link.q);
    558	p->link.vcc = NULL;
    559	p->link.sock = NULL;
    560	p->link.common.classid = sch->handle;
    561	p->link.ref = 1;
    562
    563	err = tcf_block_get(&p->link.block, &p->link.filter_list, sch,
    564			    extack);
    565	if (err)
    566		return err;
    567
    568	tasklet_setup(&p->task, sch_atm_dequeue);
    569	return 0;
    570}
    571
    572static void atm_tc_reset(struct Qdisc *sch)
    573{
    574	struct atm_qdisc_data *p = qdisc_priv(sch);
    575	struct atm_flow_data *flow;
    576
    577	pr_debug("atm_tc_reset(sch %p,[qdisc %p])\n", sch, p);
    578	list_for_each_entry(flow, &p->flows, list)
    579		qdisc_reset(flow->q);
    580	sch->q.qlen = 0;
    581}
    582
    583static void atm_tc_destroy(struct Qdisc *sch)
    584{
    585	struct atm_qdisc_data *p = qdisc_priv(sch);
    586	struct atm_flow_data *flow, *tmp;
    587
    588	pr_debug("atm_tc_destroy(sch %p,[qdisc %p])\n", sch, p);
    589	list_for_each_entry(flow, &p->flows, list) {
    590		tcf_block_put(flow->block);
    591		flow->block = NULL;
    592	}
    593
    594	list_for_each_entry_safe(flow, tmp, &p->flows, list) {
    595		if (flow->ref > 1)
    596			pr_err("atm_destroy: %p->ref = %d\n", flow, flow->ref);
    597		atm_tc_put(sch, (unsigned long)flow);
    598	}
    599	tasklet_kill(&p->task);
    600}
    601
    602static int atm_tc_dump_class(struct Qdisc *sch, unsigned long cl,
    603			     struct sk_buff *skb, struct tcmsg *tcm)
    604{
    605	struct atm_qdisc_data *p = qdisc_priv(sch);
    606	struct atm_flow_data *flow = (struct atm_flow_data *)cl;
    607	struct nlattr *nest;
    608
    609	pr_debug("atm_tc_dump_class(sch %p,[qdisc %p],flow %p,skb %p,tcm %p)\n",
    610		sch, p, flow, skb, tcm);
    611	if (list_empty(&flow->list))
    612		return -EINVAL;
    613	tcm->tcm_handle = flow->common.classid;
    614	tcm->tcm_info = flow->q->handle;
    615
    616	nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
    617	if (nest == NULL)
    618		goto nla_put_failure;
    619
    620	if (nla_put(skb, TCA_ATM_HDR, flow->hdr_len, flow->hdr))
    621		goto nla_put_failure;
    622	if (flow->vcc) {
    623		struct sockaddr_atmpvc pvc;
    624		int state;
    625
    626		memset(&pvc, 0, sizeof(pvc));
    627		pvc.sap_family = AF_ATMPVC;
    628		pvc.sap_addr.itf = flow->vcc->dev ? flow->vcc->dev->number : -1;
    629		pvc.sap_addr.vpi = flow->vcc->vpi;
    630		pvc.sap_addr.vci = flow->vcc->vci;
    631		if (nla_put(skb, TCA_ATM_ADDR, sizeof(pvc), &pvc))
    632			goto nla_put_failure;
    633		state = ATM_VF2VS(flow->vcc->flags);
    634		if (nla_put_u32(skb, TCA_ATM_STATE, state))
    635			goto nla_put_failure;
    636	}
    637	if (flow->excess) {
    638		if (nla_put_u32(skb, TCA_ATM_EXCESS, flow->common.classid))
    639			goto nla_put_failure;
    640	} else {
    641		if (nla_put_u32(skb, TCA_ATM_EXCESS, 0))
    642			goto nla_put_failure;
    643	}
    644	return nla_nest_end(skb, nest);
    645
    646nla_put_failure:
    647	nla_nest_cancel(skb, nest);
    648	return -1;
    649}
    650static int
    651atm_tc_dump_class_stats(struct Qdisc *sch, unsigned long arg,
    652			struct gnet_dump *d)
    653{
    654	struct atm_flow_data *flow = (struct atm_flow_data *)arg;
    655
    656	if (gnet_stats_copy_basic(d, NULL, &flow->bstats, true) < 0 ||
    657	    gnet_stats_copy_queue(d, NULL, &flow->qstats, flow->q->q.qlen) < 0)
    658		return -1;
    659
    660	return 0;
    661}
    662
    663static int atm_tc_dump(struct Qdisc *sch, struct sk_buff *skb)
    664{
    665	return 0;
    666}
    667
    668static const struct Qdisc_class_ops atm_class_ops = {
    669	.graft		= atm_tc_graft,
    670	.leaf		= atm_tc_leaf,
    671	.find		= atm_tc_find,
    672	.change		= atm_tc_change,
    673	.delete		= atm_tc_delete,
    674	.walk		= atm_tc_walk,
    675	.tcf_block	= atm_tc_tcf_block,
    676	.bind_tcf	= atm_tc_bind_filter,
    677	.unbind_tcf	= atm_tc_put,
    678	.dump		= atm_tc_dump_class,
    679	.dump_stats	= atm_tc_dump_class_stats,
    680};
    681
    682static struct Qdisc_ops atm_qdisc_ops __read_mostly = {
    683	.cl_ops		= &atm_class_ops,
    684	.id		= "atm",
    685	.priv_size	= sizeof(struct atm_qdisc_data),
    686	.enqueue	= atm_tc_enqueue,
    687	.dequeue	= atm_tc_dequeue,
    688	.peek		= atm_tc_peek,
    689	.init		= atm_tc_init,
    690	.reset		= atm_tc_reset,
    691	.destroy	= atm_tc_destroy,
    692	.dump		= atm_tc_dump,
    693	.owner		= THIS_MODULE,
    694};
    695
    696static int __init atm_init(void)
    697{
    698	return register_qdisc(&atm_qdisc_ops);
    699}
    700
    701static void __exit atm_exit(void)
    702{
    703	unregister_qdisc(&atm_qdisc_ops);
    704}
    705
    706module_init(atm_init)
    707module_exit(atm_exit)
    708MODULE_LICENSE("GPL");