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/init.h>
   7 #include <linux/string.h>
   8 #include <linux/errno.h>
   9 #include <linux/skbuff.h>
  10 #include <linux/atmdev.h>
  11 #include <linux/atmclip.h>
  12 #include <linux/rtnetlink.h>
  13 #include <linux/file.h>         /* for fput */
  14 #include <net/netlink.h>
  15 #include <net/pkt_sched.h>
  16
  17 extern struct socket *sockfd_lookup(int fd, int *err);  /* @@@ fix this */
  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 bstats;
  53         struct gnet_stats_queue qstats;
  54         struct atm_flow_data    *next;
  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 atm_flow_data    *flows;         /* NB: "link" is also on this
  64                                                    list */
  65         struct tasklet_struct   task;           /* requeue tasklet */
  66 };
  67
  68 /* ------------------------- Class/flow operations ------------------------- */
  69
  70 static int find_flow(struct atm_qdisc_data *qdisc, struct atm_flow_data *flow)
  71 {
  72         struct atm_flow_data *walk;
  73
  74         pr_debug("find_flow(qdisc %p,flow %p)\n", qdisc, flow);
  75         for (walk = qdisc->flows; walk; walk = walk->next)
  76                 if (walk == flow)
  77                         return 1;
  78         pr_debug("find_flow: not found\n");
  79         return 0;
  80 }
  81
  82 static inline struct atm_flow_data *lookup_flow(struct Qdisc *sch, u32 classid)
  83 {
  84         struct atm_qdisc_data *p = qdisc_priv(sch);
  85         struct atm_flow_data *flow;
  86
  87         for (flow = p->flows; flow; flow = flow->next)
  88                 if (flow->classid == classid)
  89                         break;
  90         return flow;
  91 }
  92
  93 static int atm_tc_graft(struct Qdisc *sch, unsigned long arg,
  94                         struct Qdisc *new, struct Qdisc **old)
  95 {
  96         struct atm_qdisc_data *p = qdisc_priv(sch);
  97         struct atm_flow_data *flow = (struct atm_flow_data *)arg;
  98
  99         pr_debug("atm_tc_graft(sch %p,[qdisc %p],flow %p,new %p,old %p)\n",
 100                 sch, p, flow, new, old);
 101         if (!find_flow(p, flow))
 102                 return -EINVAL;
 103         if (!new)
 104                 new = &noop_qdisc;
 105         *old = xchg(&flow->q, new);
 106         if (*old)
 107                 qdisc_reset(*old);
 108         return 0;
 109 }
 110
 111 static struct Qdisc *atm_tc_leaf(struct Qdisc *sch, unsigned long cl)
 112 {
 113         struct atm_flow_data *flow = (struct atm_flow_data *)cl;
 114
 115         pr_debug("atm_tc_leaf(sch %p,flow %p)\n", sch, flow);
 116         return flow ? flow->q : NULL;
 117 }
 118
 119 static unsigned long atm_tc_get(struct Qdisc *sch, u32 classid)
 120 {
 121         struct atm_qdisc_data *p __maybe_unused = qdisc_priv(sch);
 122         struct atm_flow_data *flow;
 123
 124         pr_debug("atm_tc_get(sch %p,[qdisc %p],classid %x)\n", sch, p, classid);
 125         flow = lookup_flow(sch, classid);
 126         if (flow)
 127                 flow->ref++;
 128         pr_debug("atm_tc_get: flow %p\n", flow);
 129         return (unsigned long)flow;
 130 }
 131
 132 static unsigned long atm_tc_bind_filter(struct Qdisc *sch,
 133                                         unsigned long parent, u32 classid)
 134 {
 135         return atm_tc_get(sch, classid);
 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         struct atm_flow_data **prev;
 148
 149         pr_debug("atm_tc_put(sch %p,[qdisc %p],flow %p)\n", sch, p, flow);
 150         if (--flow->ref)
 151                 return;
 152         pr_debug("atm_tc_put: destroying\n");
 153         for (prev = &p->flows; *prev; prev = &(*prev)->next)
 154                 if (*prev == flow)
 155                         break;
 156         if (!*prev) {
 157                 printk(KERN_CRIT "atm_tc_put: class %p not found\n", flow);
 158                 return;
 159         }
 160         *prev = flow->next;
 161         pr_debug("atm_tc_put: qdisc %p\n", flow->q);
 162         qdisc_destroy(flow->q);
 163         tcf_destroy_chain(flow->filter_list);
 164         if (flow->sock) {
 165                 pr_debug("atm_tc_put: f_count %d\n",
 166                         file_count(flow->sock->file));
 167                 flow->vcc->pop = flow->old_pop;
 168                 sockfd_put(flow->sock);
 169         }
 170         if (flow->excess)
 171                 atm_tc_put(sch, (unsigned long)flow->excess);
 172         if (flow != &p->link)
 173                 kfree(flow);
 174         /*
 175          * If flow == &p->link, the qdisc no longer works at this point and
 176          * needs to be removed. (By the caller of atm_tc_put.)
 177          */
 178 }
 179
 180 static void sch_atm_pop(struct atm_vcc *vcc, struct sk_buff *skb)
 181 {
 182         struct atm_qdisc_data *p = VCC2FLOW(vcc)->parent;
 183
 184         pr_debug("sch_atm_pop(vcc %p,skb %p,[qdisc %p])\n", vcc, skb, p);
 185         VCC2FLOW(vcc)->old_pop(vcc, skb);
 186         tasklet_schedule(&p->task);
 187 }
 188
 189 static const u8 llc_oui_ip[] = {
 190         0xaa,                   /* DSAP: non-ISO */
 191         0xaa,                   /* SSAP: non-ISO */
 192         0x03,                   /* Ctrl: Unnumbered Information Command PDU */
 193         0x00,                   /* OUI: EtherType */
 194         0x00, 0x00,
 195         0x08, 0x00
 196 };                              /* Ethertype IP (0800) */
 197
 198 static const struct nla_policy atm_policy[TCA_ATM_MAX + 1] = {
 199         [TCA_ATM_FD]            = { .type = NLA_U32 },
 200         [TCA_ATM_EXCESS]        = { .type = NLA_U32 },
 201 };
 202
 203 static int atm_tc_change(struct Qdisc *sch, u32 classid, u32 parent,
 204                          struct nlattr **tca, unsigned long *arg)
 205 {
 206         struct atm_qdisc_data *p = qdisc_priv(sch);
 207         struct atm_flow_data *flow = (struct atm_flow_data *)*arg;
 208         struct atm_flow_data *excess = NULL;
 209         struct nlattr *opt = tca[TCA_OPTIONS];
 210         struct nlattr *tb[TCA_ATM_MAX + 1];
 211         struct socket *sock;
 212         int fd, error, hdr_len;
 213         void *hdr;
 214
 215         pr_debug("atm_tc_change(sch %p,[qdisc %p],classid %x,parent %x,"
 216                 "flow %p,opt %p)\n", sch, p, classid, parent, flow, opt);
 217         /*
 218          * The concept of parents doesn't apply for this qdisc.
 219          */
 220         if (parent && parent != TC_H_ROOT && parent != sch->handle)
 221                 return -EINVAL;
 222         /*
 223          * ATM classes cannot be changed. In order to change properties of the
 224          * ATM connection, that socket needs to be modified directly (via the
 225          * native ATM API. In order to send a flow to a different VC, the old
 226          * class needs to be removed and a new one added. (This may be changed
 227          * later.)
 228          */
 229         if (flow)
 230                 return -EBUSY;
 231         if (opt == NULL)
 232                 return -EINVAL;
 233
 234         error = nla_parse_nested(tb, TCA_ATM_MAX, opt, atm_policy);
 235         if (error < 0)
 236                 return error;
 237
 238         if (!tb[TCA_ATM_FD])
 239                 return -EINVAL;
 240         fd = nla_get_u32(tb[TCA_ATM_FD]);
 241         pr_debug("atm_tc_change: fd %d\n", fd);
 242         if (tb[TCA_ATM_HDR]) {
 243                 hdr_len = nla_len(tb[TCA_ATM_HDR]);
 244                 hdr = nla_data(tb[TCA_ATM_HDR]);
 245         } else {
 246                 hdr_len = RFC1483LLC_LEN;
 247                 hdr = NULL;     /* default LLC/SNAP for IP */
 248         }
 249         if (!tb[TCA_ATM_EXCESS])
 250                 excess = NULL;
 251         else {
 252                 excess = (struct atm_flow_data *)
 253                         atm_tc_get(sch, nla_get_u32(tb[TCA_ATM_EXCESS]));
 254                 if (!excess)
 255                         return -ENOENT;
 256         }
 257         pr_debug("atm_tc_change: type %d, payload %d, hdr_len %d\n",
 258                  opt->nla_type, nla_len(opt), hdr_len);
 259         sock = sockfd_lookup(fd, &error);
 260         if (!sock)
 261                 return error;   /* f_count++ */
 262         pr_debug("atm_tc_change: f_count %d\n", file_count(sock->file));
 263         if (sock->ops->family != PF_ATMSVC && sock->ops->family != PF_ATMPVC) {
 264                 error = -EPROTOTYPE;
 265                 goto err_out;
 266         }
 267         /* @@@ should check if the socket is really operational or we'll crash
 268            on vcc->send */
 269         if (classid) {
 270                 if (TC_H_MAJ(classid ^ sch->handle)) {
 271                         pr_debug("atm_tc_change: classid mismatch\n");
 272                         error = -EINVAL;
 273                         goto err_out;
 274                 }
 275                 if (find_flow(p, flow)) {
 276                         error = -EEXIST;
 277                         goto err_out;
 278                 }
 279         } else {
 280                 int i;
 281                 unsigned long cl;
 282
 283                 for (i = 1; i < 0x8000; i++) {
 284                         classid = TC_H_MAKE(sch->handle, 0x8000 | i);
 285                         cl = atm_tc_get(sch, classid);
 286                         if (!cl)
 287                                 break;
 288                         atm_tc_put(sch, cl);
 289                 }
 290         }
 291         pr_debug("atm_tc_change: new id %x\n", classid);
 292         flow = kzalloc(sizeof(struct atm_flow_data) + hdr_len, GFP_KERNEL);
 293         pr_debug("atm_tc_change: flow %p\n", flow);
 294         if (!flow) {
 295                 error = -ENOBUFS;
 296                 goto err_out;
 297         }
 298         flow->filter_list = NULL;
 299         flow->q = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops, classid);
 300         if (!flow->q)
 301                 flow->q = &noop_qdisc;
 302         pr_debug("atm_tc_change: qdisc %p\n", flow->q);
 303         flow->sock = sock;
 304         flow->vcc = ATM_SD(sock);       /* speedup */
 305         flow->vcc->user_back = flow;
 306         pr_debug("atm_tc_change: vcc %p\n", flow->vcc);
 307         flow->old_pop = flow->vcc->pop;
 308         flow->parent = p;
 309         flow->vcc->pop = sch_atm_pop;
 310         flow->classid = classid;
 311         flow->ref = 1;
 312         flow->excess = excess;
 313         flow->next = p->link.next;
 314         p->link.next = flow;
 315         flow->hdr_len = hdr_len;
 316         if (hdr)
 317                 memcpy(flow->hdr, hdr, hdr_len);
 318         else
 319                 memcpy(flow->hdr, llc_oui_ip, sizeof(llc_oui_ip));
 320         *arg = (unsigned long)flow;
 321         return 0;
 322 err_out:
 323         if (excess)
 324                 atm_tc_put(sch, (unsigned long)excess);
 325         sockfd_put(sock);
 326         return error;
 327 }
 328
 329 static int atm_tc_delete(struct Qdisc *sch, unsigned long arg)
 330 {
 331         struct atm_qdisc_data *p = qdisc_priv(sch);
 332         struct atm_flow_data *flow = (struct atm_flow_data *)arg;
 333
 334         pr_debug("atm_tc_delete(sch %p,[qdisc %p],flow %p)\n", sch, p, flow);
 335         if (!find_flow(qdisc_priv(sch), flow))
 336                 return -EINVAL;
 337         if (flow->filter_list || flow == &p->link)
 338                 return -EBUSY;
 339         /*
 340          * Reference count must be 2: one for "keepalive" (set at class
 341          * creation), and one for the reference held when calling delete.
 342          */
 343         if (flow->ref < 2) {
 344                 printk(KERN_ERR "atm_tc_delete: flow->ref == %d\n", flow->ref);
 345                 return -EINVAL;
 346         }
 347         if (flow->ref > 2)
 348                 return -EBUSY;  /* catch references via excess, etc. */
 349         atm_tc_put(sch, arg);
 350         return 0;
 351 }
 352
 353 static void atm_tc_walk(struct Qdisc *sch, struct qdisc_walker *walker)
 354 {
 355         struct atm_qdisc_data *p = qdisc_priv(sch);
 356         struct atm_flow_data *flow;
 357
 358         pr_debug("atm_tc_walk(sch %p,[qdisc %p],walker %p)\n", sch, p, walker);
 359         if (walker->stop)
 360                 return;
 361         for (flow = p->flows; flow; flow = flow->next) {
 362                 if (walker->count >= walker->skip)
 363                         if (walker->fn(sch, (unsigned long)flow, walker) < 0) {
 364                                 walker->stop = 1;
 365                                 break;
 366                         }
 367                 walker->count++;
 368         }
 369 }
 370
 371 static struct tcf_proto **atm_tc_find_tcf(struct Qdisc *sch, unsigned long cl)
 372 {
 373         struct atm_qdisc_data *p = qdisc_priv(sch);
 374         struct atm_flow_data *flow = (struct atm_flow_data *)cl;
 375
 376         pr_debug("atm_tc_find_tcf(sch %p,[qdisc %p],flow %p)\n", sch, p, flow);
 377         return flow ? &flow->filter_list : &p->link.filter_list;
 378 }
 379
 380 /* --------------------------- Qdisc operations ---------------------------- */
 381
 382 static int atm_tc_enqueue(struct sk_buff *skb, struct Qdisc *sch)
 383 {
 384         struct atm_qdisc_data *p = qdisc_priv(sch);
 385         struct atm_flow_data *flow = NULL;      /* @@@ */
 386         struct tcf_result res;
 387         int result;
 388         int ret = NET_XMIT_POLICED;
 389
 390         pr_debug("atm_tc_enqueue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);
 391         result = TC_POLICE_OK;  /* be nice to gcc */
 392         if (TC_H_MAJ(skb->priority) != sch->handle ||
 393             !(flow = (struct atm_flow_data *)atm_tc_get(sch, skb->priority)))
 394                 for (flow = p->flows; flow; flow = flow->next)
 395                         if (flow->filter_list) {
 396                                 result = tc_classify_compat(skb,
 397                                                             flow->filter_list,
 398                                                             &res);
 399                                 if (result < 0)
 400                                         continue;
 401                                 flow = (struct atm_flow_data *)res.class;
 402                                 if (!flow)
 403                                         flow = lookup_flow(sch, res.classid);
 404                                 break;
 405                         }
 406         if (!flow)
 407                 flow = &p->link;
 408         else {
 409                 if (flow->vcc)
 410                         ATM_SKB(skb)->atm_options = flow->vcc->atm_options;
 411                 /*@@@ looks good ... but it's not supposed to work :-) */
 412 #ifdef CONFIG_NET_CLS_ACT
 413                 switch (result) {
 414                 case TC_ACT_QUEUED:
 415                 case TC_ACT_STOLEN:
 416                         kfree_skb(skb);
 417                         return NET_XMIT_SUCCESS;
 418                 case TC_ACT_SHOT:
 419                         kfree_skb(skb);
 420                         goto drop;
 421                 case TC_POLICE_RECLASSIFY:
 422                         if (flow->excess)
 423                                 flow = flow->excess;
 424                         else
 425                                 ATM_SKB(skb)->atm_options |= ATM_ATMOPT_CLP;
 426                         break;
 427                 }
 428 #endif
 429         }
 430
 431         ret = flow->q->enqueue(skb, flow->q);
 432         if (ret != 0) {
 433 drop: __maybe_unused
 434                 sch->qstats.drops++;
 435                 if (flow)
 436                         flow->qstats.drops++;
 437                 return ret;
 438         }
 439         sch->bstats.bytes += skb->len;
 440         sch->bstats.packets++;
 441         flow->bstats.bytes += skb->len;
 442         flow->bstats.packets++;
 443         /*
 444          * Okay, this may seem weird. We pretend we've dropped the packet if
 445          * it goes via ATM. The reason for this is that the outer qdisc
 446          * expects to be able to q->dequeue the packet later on if we return
 447          * success at this place. Also, sch->q.qdisc needs to reflect whether
 448          * there is a packet egligible for dequeuing or not. Note that the
 449          * statistics of the outer qdisc are necessarily wrong because of all
 450          * this. There's currently no correct solution for this.
 451          */
 452         if (flow == &p->link) {
 453                 sch->q.qlen++;
 454                 return 0;
 455         }
 456         tasklet_schedule(&p->task);
 457         return NET_XMIT_BYPASS;
 458 }
 459
 460 /*
 461  * Dequeue packets and send them over ATM. Note that we quite deliberately
 462  * avoid checking net_device's flow control here, simply because sch_atm
 463  * uses its own channels, which have nothing to do with any CLIP/LANE/or
 464  * non-ATM interfaces.
 465  */
 466
 467 static void sch_atm_dequeue(unsigned long data)
 468 {
 469         struct Qdisc *sch = (struct Qdisc *)data;
 470         struct atm_qdisc_data *p = qdisc_priv(sch);
 471         struct atm_flow_data *flow;
 472         struct sk_buff *skb;
 473
 474         pr_debug("sch_atm_dequeue(sch %p,[qdisc %p])\n", sch, p);
 475         for (flow = p->link.next; flow; flow = flow->next)
 476                 /*
 477                  * If traffic is properly shaped, this won't generate nasty
 478                  * little bursts. Otherwise, it may ... (but that's okay)
 479                  */
 480                 while ((skb = flow->q->dequeue(flow->q))) {
 481                         if (!atm_may_send(flow->vcc, skb->truesize)) {
 482                                 (void)flow->q->ops->requeue(skb, flow->q);
 483                                 break;
 484                         }
 485                         pr_debug("atm_tc_dequeue: sending on class %p\n", flow);
 486                         /* remove any LL header somebody else has attached */
 487                         skb_pull(skb, skb_network_offset(skb));
 488                         if (skb_headroom(skb) < flow->hdr_len) {
 489                                 struct sk_buff *new;
 490
 491                                 new = skb_realloc_headroom(skb, flow->hdr_len);
 492                                 dev_kfree_skb(skb);
 493                                 if (!new)
 494                                         continue;
 495                                 skb = new;
 496                         }
 497                         pr_debug("sch_atm_dequeue: ip %p, data %p\n",
 498                                  skb_network_header(skb), skb->data);
 499                         ATM_SKB(skb)->vcc = flow->vcc;
 500                         memcpy(skb_push(skb, flow->hdr_len), flow->hdr,
 501                                flow->hdr_len);
 502                         atomic_add(skb->truesize,
 503                                    &sk_atm(flow->vcc)->sk_wmem_alloc);
 504                         /* atm.atm_options are already set by atm_tc_enqueue */
 505                         flow->vcc->send(flow->vcc, skb);
 506                 }
 507 }
 508
 509 static struct sk_buff *atm_tc_dequeue(struct Qdisc *sch)
 510 {
 511         struct atm_qdisc_data *p = qdisc_priv(sch);
 512         struct sk_buff *skb;
 513
 514         pr_debug("atm_tc_dequeue(sch %p,[qdisc %p])\n", sch, p);
 515         tasklet_schedule(&p->task);
 516         skb = p->link.q->dequeue(p->link.q);
 517         if (skb)
 518                 sch->q.qlen--;
 519         return skb;
 520 }
 521
 522 static int atm_tc_requeue(struct sk_buff *skb, struct Qdisc *sch)
 523 {
 524         struct atm_qdisc_data *p = qdisc_priv(sch);
 525         int ret;
 526
 527         pr_debug("atm_tc_requeue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);
 528         ret = p->link.q->ops->requeue(skb, p->link.q);
 529         if (!ret) {
 530                 sch->q.qlen++;
 531                 sch->qstats.requeues++;
 532         } else {
 533                 sch->qstats.drops++;
 534                 p->link.qstats.drops++;
 535         }
 536         return ret;
 537 }
 538
 539 static unsigned int atm_tc_drop(struct Qdisc *sch)
 540 {
 541         struct atm_qdisc_data *p = qdisc_priv(sch);
 542         struct atm_flow_data *flow;
 543         unsigned int len;
 544
 545         pr_debug("atm_tc_drop(sch %p,[qdisc %p])\n", sch, p);
 546         for (flow = p->flows; flow; flow = flow->next)
 547                 if (flow->q->ops->drop && (len = flow->q->ops->drop(flow->q)))
 548                         return len;
 549         return 0;
 550 }
 551
 552 static int atm_tc_init(struct Qdisc *sch, struct nlattr *opt)
 553 {
 554         struct atm_qdisc_data *p = qdisc_priv(sch);
 555
 556         pr_debug("atm_tc_init(sch %p,[qdisc %p],opt %p)\n", sch, p, opt);
 557         p->flows = &p->link;
 558         p->link.q = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops, sch->handle);
 559         if (!p->link.q)
 560                 p->link.q = &noop_qdisc;
 561         pr_debug("atm_tc_init: link (%p) qdisc %p\n", &p->link, p->link.q);
 562         p->link.filter_list = NULL;
 563         p->link.vcc = NULL;
 564         p->link.sock = NULL;
 565         p->link.classid = sch->handle;
 566         p->link.ref = 1;
 567         p->link.next = NULL;
 568         tasklet_init(&p->task, sch_atm_dequeue, (unsigned long)sch);
 569         return 0;
 570 }
 571
 572 static 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         for (flow = p->flows; flow; flow = flow->next)
 579                 qdisc_reset(flow->q);
 580         sch->q.qlen = 0;
 581 }
 582
 583 static void atm_tc_destroy(struct Qdisc *sch)
 584 {
 585         struct atm_qdisc_data *p = qdisc_priv(sch);
 586         struct atm_flow_data *flow;
 587
 588         pr_debug("atm_tc_destroy(sch %p,[qdisc %p])\n", sch, p);
 589         /* races ? */
 590         while ((flow = p->flows)) {
 591                 tcf_destroy_chain(flow->filter_list);
 592                 flow->filter_list = NULL;
 593                 if (flow->ref > 1)
 594                         printk(KERN_ERR "atm_destroy: %p->ref = %d\n", flow,
 595                                flow->ref);
 596                 atm_tc_put(sch, (unsigned long)flow);
 597                 if (p->flows == flow) {
 598                         printk(KERN_ERR "atm_destroy: putting flow %p didn't "
 599                                "kill it\n", flow);
 600                         p->flows = flow->next;  /* brute force */
 601                         break;
 602                 }
 603         }
 604         tasklet_kill(&p->task);
 605 }
 606
 607 static int atm_tc_dump_class(struct Qdisc *sch, unsigned long cl,
 608                              struct sk_buff *skb, struct tcmsg *tcm)
 609 {
 610         struct atm_qdisc_data *p = qdisc_priv(sch);
 611         struct atm_flow_data *flow = (struct atm_flow_data *)cl;
 612         struct nlattr *nest;
 613
 614         pr_debug("atm_tc_dump_class(sch %p,[qdisc %p],flow %p,skb %p,tcm %p)\n",
 615                 sch, p, flow, skb, tcm);
 616         if (!find_flow(p, flow))
 617                 return -EINVAL;
 618         tcm->tcm_handle = flow->classid;
 619         tcm->tcm_info = flow->q->handle;
 620
 621         nest = nla_nest_start(skb, TCA_OPTIONS);
 622         if (nest == NULL)
 623                 goto nla_put_failure;
 624
 625         NLA_PUT(skb, TCA_ATM_HDR, flow->hdr_len, flow->hdr);
 626         if (flow->vcc) {
 627                 struct sockaddr_atmpvc pvc;
 628                 int state;
 629
 630                 pvc.sap_family = AF_ATMPVC;
 631                 pvc.sap_addr.itf = flow->vcc->dev ? flow->vcc->dev->number : -1;
 632                 pvc.sap_addr.vpi = flow->vcc->vpi;
 633                 pvc.sap_addr.vci = flow->vcc->vci;
 634                 NLA_PUT(skb, TCA_ATM_ADDR, sizeof(pvc), &pvc);
 635                 state = ATM_VF2VS(flow->vcc->flags);
 636                 NLA_PUT_U32(skb, TCA_ATM_STATE, state);
 637         }
 638         if (flow->excess)
 639                 NLA_PUT_U32(skb, TCA_ATM_EXCESS, flow->classid);
 640         else {
 641                 NLA_PUT_U32(skb, TCA_ATM_EXCESS, 0);
 642         }
 643
 644         nla_nest_end(skb, nest);
 645         return skb->len;
 646
 647 nla_put_failure:
 648         nla_nest_cancel(skb, nest);
 649         return -1;
 650 }
 651 static int
 652 atm_tc_dump_class_stats(struct Qdisc *sch, unsigned long arg,
 653                         struct gnet_dump *d)
 654 {
 655         struct atm_flow_data *flow = (struct atm_flow_data *)arg;
 656
 657         flow->qstats.qlen = flow->q->q.qlen;
 658
 659         if (gnet_stats_copy_basic(d, &flow->bstats) < 0 ||
 660             gnet_stats_copy_queue(d, &flow->qstats) < 0)
 661                 return -1;
 662
 663         return 0;
 664 }
 665
 666 static int atm_tc_dump(struct Qdisc *sch, struct sk_buff *skb)
 667 {
 668         return 0;
 669 }
 670
 671 static const struct Qdisc_class_ops atm_class_ops = {
 672         .graft          = atm_tc_graft,
 673         .leaf           = atm_tc_leaf,
 674         .get            = atm_tc_get,
 675         .put            = atm_tc_put,
 676         .change         = atm_tc_change,
 677         .delete         = atm_tc_delete,
 678         .walk           = atm_tc_walk,
 679         .tcf_chain      = atm_tc_find_tcf,
 680         .bind_tcf       = atm_tc_bind_filter,
 681         .unbind_tcf     = atm_tc_put,
 682         .dump           = atm_tc_dump_class,
 683         .dump_stats     = atm_tc_dump_class_stats,
 684 };
 685
 686 static struct Qdisc_ops atm_qdisc_ops __read_mostly = {
 687         .cl_ops         = &atm_class_ops,
 688         .id             = "atm",
 689         .priv_size      = sizeof(struct atm_qdisc_data),
 690         .enqueue        = atm_tc_enqueue,
 691         .dequeue        = atm_tc_dequeue,
 692         .requeue        = atm_tc_requeue,
 693         .drop           = atm_tc_drop,
 694         .init           = atm_tc_init,
 695         .reset          = atm_tc_reset,
 696         .destroy        = atm_tc_destroy,
 697         .dump           = atm_tc_dump,
 698         .owner          = THIS_MODULE,
 699 };
 700
 701 static int __init atm_init(void)
 702 {
 703         return register_qdisc(&atm_qdisc_ops);
 704 }
 705
 706 static void __exit atm_exit(void)
 707 {
 708         unregister_qdisc(&atm_qdisc_ops);
 709 }
 710
 711 module_init(atm_init)
 712 module_exit(atm_exit)
 713 MODULE_LICENSE("GPL");