net/sched/sch_atm.c

   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_packed  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
  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
  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
 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
 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
 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  */
 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
 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
 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
 323 static int atm_tc_delete(struct Qdisc *sch, unsigned long arg)
 324 {
 325         struct atm_qdisc_data *p = qdisc_priv(sch);
 326         struct atm_flow_data *flow = (struct atm_flow_data *)arg;
 327
 328         pr_debug("atm_tc_delete(sch %p,[qdisc %p],flow %p)\n", sch, p, flow);
 329         if (list_empty(&flow->list))
 330                 return -EINVAL;
 331         if (rcu_access_pointer(flow->filter_list) || flow == &p->link)
 332                 return -EBUSY;
 333         /*
 334          * Reference count must be 2: one for "keepalive" (set at class
 335          * creation), and one for the reference held when calling delete.
 336          */
 337         if (flow->ref < 2) {
 338                 pr_err("atm_tc_delete: flow->ref == %d\n", flow->ref);
 339                 return -EINVAL;
 340         }
 341         if (flow->ref > 2)
 342                 return -EBUSY;  /* catch references via excess, etc. */
 343         atm_tc_put(sch, arg);
 344         return 0;
 345 }
 346
 347 static void atm_tc_walk(struct Qdisc *sch, struct qdisc_walker *walker)
 348 {
 349         struct atm_qdisc_data *p = qdisc_priv(sch);
 350         struct atm_flow_data *flow;
 351
 352         pr_debug("atm_tc_walk(sch %p,[qdisc %p],walker %p)\n", sch, p, walker);
 353         if (walker->stop)
 354                 return;
 355         list_for_each_entry(flow, &p->flows, list) {
 356                 if (walker->count >= walker->skip &&
 357                     walker->fn(sch, (unsigned long)flow, walker) < 0) {
 358                         walker->stop = 1;
 359                         break;
 360                 }
 361                 walker->count++;
 362         }
 363 }
 364
 365 static struct tcf_block *atm_tc_tcf_block(struct Qdisc *sch, unsigned long cl,
 366                                           struct netlink_ext_ack *extack)
 367 {
 368         struct atm_qdisc_data *p = qdisc_priv(sch);
 369         struct atm_flow_data *flow = (struct atm_flow_data *)cl;
 370
 371         pr_debug("atm_tc_find_tcf(sch %p,[qdisc %p],flow %p)\n", sch, p, flow);
 372         return flow ? flow->block : p->link.block;
 373 }
 374
 375 /* --------------------------- Qdisc operations ---------------------------- */
 376
 377 static int atm_tc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 378                           struct sk_buff **to_free)
 379 {
 380         struct atm_qdisc_data *p = qdisc_priv(sch);
 381         struct atm_flow_data *flow;
 382         struct tcf_result res;
 383         int result;
 384         int ret = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
 385
 386         pr_debug("atm_tc_enqueue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);
 387         result = TC_ACT_OK;     /* be nice to gcc */
 388         flow = NULL;
 389         if (TC_H_MAJ(skb->priority) != sch->handle ||
 390             !(flow = (struct atm_flow_data *)atm_tc_find(sch, skb->priority))) {
 391                 struct tcf_proto *fl;
 392
 393                 list_for_each_entry(flow, &p->flows, list) {
 394                         fl = rcu_dereference_bh(flow->filter_list);
 395                         if (fl) {
 396                                 result = tcf_classify(skb, fl, &res, true);
 397                                 if (result < 0)
 398                                         continue;
 399                                 flow = (struct atm_flow_data *)res.class;
 400                                 if (!flow)
 401                                         flow = lookup_flow(sch, res.classid);
 402                                 goto done;
 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
 469 static void sch_atm_dequeue(unsigned long data)
 470 {
 471         struct Qdisc *sch = (struct Qdisc *)data;
 472         struct atm_qdisc_data *p = qdisc_priv(sch);
 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
 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
 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
 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         list_add(&p->link.list, &p->flows);
 551         p->link.q = qdisc_create_dflt(sch->dev_queue,
 552                                       &pfifo_qdisc_ops, sch->handle, extack);
 553         if (!p->link.q)
 554                 p->link.q = &noop_qdisc;
 555         pr_debug("atm_tc_init: link (%p) qdisc %p\n", &p->link, p->link.q);
 556
 557         err = tcf_block_get(&p->link.block, &p->link.filter_list, sch,
 558                             extack);
 559         if (err)
 560                 return err;
 561
 562         p->link.vcc = NULL;
 563         p->link.sock = NULL;
 564         p->link.common.classid = sch->handle;
 565         p->link.ref = 1;
 566         tasklet_init(&p->task, sch_atm_dequeue, (unsigned long)sch);
 567         return 0;
 568 }
 569
 570 static void atm_tc_reset(struct Qdisc *sch)
 571 {
 572         struct atm_qdisc_data *p = qdisc_priv(sch);
 573         struct atm_flow_data *flow;
 574
 575         pr_debug("atm_tc_reset(sch %p,[qdisc %p])\n", sch, p);
 576         list_for_each_entry(flow, &p->flows, list)
 577                 qdisc_reset(flow->q);
 578         sch->q.qlen = 0;
 579 }
 580
 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
 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
 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(qdisc_root_sleeping_running(sch),
 655                                   d, NULL, &flow->bstats) < 0 ||
 656             gnet_stats_copy_queue(d, NULL, &flow->qstats, flow->q->q.qlen) < 0)
 657                 return -1;
 658
 659         return 0;
 660 }
 661
 662 static int atm_tc_dump(struct Qdisc *sch, struct sk_buff *skb)
 663 {
 664         return 0;
 665 }
 666
 667 static const struct Qdisc_class_ops atm_class_ops = {
 668         .graft          = atm_tc_graft,
 669         .leaf           = atm_tc_leaf,
 670         .find           = atm_tc_find,
 671         .change         = atm_tc_change,
 672         .delete         = atm_tc_delete,
 673         .walk           = atm_tc_walk,
 674         .tcf_block      = atm_tc_tcf_block,
 675         .bind_tcf       = atm_tc_bind_filter,
 676         .unbind_tcf     = atm_tc_put,
 677         .dump           = atm_tc_dump_class,
 678         .dump_stats     = atm_tc_dump_class_stats,
 679 };
 680
 681 static struct Qdisc_ops atm_qdisc_ops __read_mostly = {
 682         .cl_ops         = &atm_class_ops,
 683         .id             = "atm",
 684         .priv_size      = sizeof(struct atm_qdisc_data),
 685         .enqueue        = atm_tc_enqueue,
 686         .dequeue        = atm_tc_dequeue,
 687         .peek           = atm_tc_peek,
 688         .init           = atm_tc_init,
 689         .reset          = atm_tc_reset,
 690         .destroy        = atm_tc_destroy,
 691         .dump           = atm_tc_dump,
 692         .owner          = THIS_MODULE,
 693 };
 694
 695 static int __init atm_init(void)
 696 {
 697         return register_qdisc(&atm_qdisc_ops);
 698 }
 699
 700 static void __exit atm_exit(void)
 701 {
 702         unregister_qdisc(&atm_qdisc_ops);
 703 }
 704
 705 module_init(atm_init)
 706 module_exit(atm_exit)
 707 MODULE_LICENSE("GPL");