net/sched/sch_atm.c

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