1 /* net/sched/sch_atm.c - ATM VC selection "queueing discipline" */
3 /* Written 1998-2000 by Werner Almesberger, EPFL ICA */
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>
17 extern struct socket *sockfd_lookup(int fd, int *err); /* @@@ fix this */
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.
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.
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
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 (?)
40 #define VCC2FLOW(vcc) ((struct atm_flow_data *) ((vcc)->user_back))
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 */
58 unsigned char hdr[0]; /* header data; MUST BE LAST */
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
65 struct tasklet_struct task; /* requeue tasklet */
68 /* ------------------------- Class/flow operations ------------------------- */
70 static int find_flow(struct atm_qdisc_data *qdisc, struct atm_flow_data *flow)
72 struct atm_flow_data *walk;
74 pr_debug("find_flow(qdisc %p,flow %p)\n", qdisc, flow);
75 for (walk = qdisc->flows; walk; walk = walk->next)
78 pr_debug("find_flow: not found\n");
82 static inline struct atm_flow_data *lookup_flow(struct Qdisc *sch, u32 classid)
84 struct atm_qdisc_data *p = qdisc_priv(sch);
85 struct atm_flow_data *flow;
87 for (flow = p->flows; flow; flow = flow->next)
88 if (flow->classid == classid)
93 static int atm_tc_graft(struct Qdisc *sch, unsigned long arg,
94 struct Qdisc *new, struct Qdisc **old)
96 struct atm_qdisc_data *p = qdisc_priv(sch);
97 struct atm_flow_data *flow = (struct atm_flow_data *)arg;
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))
105 *old = xchg(&flow->q, new);
111 static struct Qdisc *atm_tc_leaf(struct Qdisc *sch, unsigned long cl)
113 struct atm_flow_data *flow = (struct atm_flow_data *)cl;
115 pr_debug("atm_tc_leaf(sch %p,flow %p)\n", sch, flow);
116 return flow ? flow->q : NULL;
119 static unsigned long atm_tc_get(struct Qdisc *sch, u32 classid)
121 struct atm_qdisc_data *p __maybe_unused = qdisc_priv(sch);
122 struct atm_flow_data *flow;
124 pr_debug("atm_tc_get(sch %p,[qdisc %p],classid %x)\n", sch, p, classid);
125 flow = lookup_flow(sch, classid);
128 pr_debug("atm_tc_get: flow %p\n", flow);
129 return (unsigned long)flow;
132 static unsigned long atm_tc_bind_filter(struct Qdisc *sch,
133 unsigned long parent, u32 classid)
135 return atm_tc_get(sch, classid);
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.
143 static void atm_tc_put(struct Qdisc *sch, unsigned long cl)
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;
149 pr_debug("atm_tc_put(sch %p,[qdisc %p],flow %p)\n", sch, p, flow);
152 pr_debug("atm_tc_put: destroying\n");
153 for (prev = &p->flows; *prev; prev = &(*prev)->next)
157 printk(KERN_CRIT "atm_tc_put: class %p not found\n", flow);
161 pr_debug("atm_tc_put: qdisc %p\n", flow->q);
162 qdisc_destroy(flow->q);
163 tcf_destroy_chain(flow->filter_list);
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);
171 atm_tc_put(sch, (unsigned long)flow->excess);
172 if (flow != &p->link)
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.)
180 static void sch_atm_pop(struct atm_vcc *vcc, struct sk_buff *skb)
182 struct atm_qdisc_data *p = VCC2FLOW(vcc)->parent;
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);
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 */
196 }; /* Ethertype IP (0800) */
198 static int atm_tc_change(struct Qdisc *sch, u32 classid, u32 parent,
199 struct nlattr **tca, unsigned long *arg)
201 struct atm_qdisc_data *p = qdisc_priv(sch);
202 struct atm_flow_data *flow = (struct atm_flow_data *)*arg;
203 struct atm_flow_data *excess = NULL;
204 struct nlattr *opt = tca[TCA_OPTIONS];
205 struct nlattr *tb[TCA_ATM_MAX + 1];
207 int fd, error, hdr_len;
210 pr_debug("atm_tc_change(sch %p,[qdisc %p],classid %x,parent %x,"
211 "flow %p,opt %p)\n", sch, p, classid, parent, flow, opt);
213 * The concept of parents doesn't apply for this qdisc.
215 if (parent && parent != TC_H_ROOT && parent != sch->handle)
218 * ATM classes cannot be changed. In order to change properties of the
219 * ATM connection, that socket needs to be modified directly (via the
220 * native ATM API. In order to send a flow to a different VC, the old
221 * class needs to be removed and a new one added. (This may be changed
226 if (opt == NULL || nla_parse_nested(tb, TCA_ATM_MAX, opt, NULL))
228 if (!tb[TCA_ATM_FD] || nla_len(tb[TCA_ATM_FD]) < sizeof(fd))
230 fd = *(int *)nla_data(tb[TCA_ATM_FD]);
231 pr_debug("atm_tc_change: fd %d\n", fd);
232 if (tb[TCA_ATM_HDR]) {
233 hdr_len = nla_len(tb[TCA_ATM_HDR]);
234 hdr = nla_data(tb[TCA_ATM_HDR]);
236 hdr_len = RFC1483LLC_LEN;
237 hdr = NULL; /* default LLC/SNAP for IP */
239 if (!tb[TCA_ATM_EXCESS])
242 if (nla_len(tb[TCA_ATM_EXCESS]) != sizeof(u32))
244 excess = (struct atm_flow_data *)
245 atm_tc_get(sch, *(u32 *)nla_data(tb[TCA_ATM_EXCESS]));
249 pr_debug("atm_tc_change: type %d, payload %lu, hdr_len %d\n",
250 opt->nla_type, nla_len(opt), hdr_len);
251 sock = sockfd_lookup(fd, &error);
253 return error; /* f_count++ */
254 pr_debug("atm_tc_change: f_count %d\n", file_count(sock->file));
255 if (sock->ops->family != PF_ATMSVC && sock->ops->family != PF_ATMPVC) {
259 /* @@@ should check if the socket is really operational or we'll crash
262 if (TC_H_MAJ(classid ^ sch->handle)) {
263 pr_debug("atm_tc_change: classid mismatch\n");
267 if (find_flow(p, flow)) {
275 for (i = 1; i < 0x8000; i++) {
276 classid = TC_H_MAKE(sch->handle, 0x8000 | i);
277 cl = atm_tc_get(sch, classid);
283 pr_debug("atm_tc_change: new id %x\n", classid);
284 flow = kzalloc(sizeof(struct atm_flow_data) + hdr_len, GFP_KERNEL);
285 pr_debug("atm_tc_change: flow %p\n", flow);
290 flow->filter_list = NULL;
291 flow->q = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops, classid);
293 flow->q = &noop_qdisc;
294 pr_debug("atm_tc_change: qdisc %p\n", flow->q);
296 flow->vcc = ATM_SD(sock); /* speedup */
297 flow->vcc->user_back = flow;
298 pr_debug("atm_tc_change: vcc %p\n", flow->vcc);
299 flow->old_pop = flow->vcc->pop;
301 flow->vcc->pop = sch_atm_pop;
302 flow->classid = classid;
304 flow->excess = excess;
305 flow->next = p->link.next;
307 flow->hdr_len = hdr_len;
309 memcpy(flow->hdr, hdr, hdr_len);
311 memcpy(flow->hdr, llc_oui_ip, sizeof(llc_oui_ip));
312 *arg = (unsigned long)flow;
316 atm_tc_put(sch, (unsigned long)excess);
321 static int atm_tc_delete(struct Qdisc *sch, unsigned long arg)
323 struct atm_qdisc_data *p = qdisc_priv(sch);
324 struct atm_flow_data *flow = (struct atm_flow_data *)arg;
326 pr_debug("atm_tc_delete(sch %p,[qdisc %p],flow %p)\n", sch, p, flow);
327 if (!find_flow(qdisc_priv(sch), flow))
329 if (flow->filter_list || flow == &p->link)
332 * Reference count must be 2: one for "keepalive" (set at class
333 * creation), and one for the reference held when calling delete.
336 printk(KERN_ERR "atm_tc_delete: flow->ref == %d\n", flow->ref);
340 return -EBUSY; /* catch references via excess, etc. */
341 atm_tc_put(sch, arg);
345 static void atm_tc_walk(struct Qdisc *sch, struct qdisc_walker *walker)
347 struct atm_qdisc_data *p = qdisc_priv(sch);
348 struct atm_flow_data *flow;
350 pr_debug("atm_tc_walk(sch %p,[qdisc %p],walker %p)\n", sch, p, walker);
353 for (flow = p->flows; flow; flow = flow->next) {
354 if (walker->count >= walker->skip)
355 if (walker->fn(sch, (unsigned long)flow, walker) < 0) {
363 static struct tcf_proto **atm_tc_find_tcf(struct Qdisc *sch, unsigned long cl)
365 struct atm_qdisc_data *p = qdisc_priv(sch);
366 struct atm_flow_data *flow = (struct atm_flow_data *)cl;
368 pr_debug("atm_tc_find_tcf(sch %p,[qdisc %p],flow %p)\n", sch, p, flow);
369 return flow ? &flow->filter_list : &p->link.filter_list;
372 /* --------------------------- Qdisc operations ---------------------------- */
374 static int atm_tc_enqueue(struct sk_buff *skb, struct Qdisc *sch)
376 struct atm_qdisc_data *p = qdisc_priv(sch);
377 struct atm_flow_data *flow = NULL; /* @@@ */
378 struct tcf_result res;
380 int ret = NET_XMIT_POLICED;
382 pr_debug("atm_tc_enqueue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);
383 result = TC_POLICE_OK; /* be nice to gcc */
384 if (TC_H_MAJ(skb->priority) != sch->handle ||
385 !(flow = (struct atm_flow_data *)atm_tc_get(sch, skb->priority)))
386 for (flow = p->flows; flow; flow = flow->next)
387 if (flow->filter_list) {
388 result = tc_classify_compat(skb,
393 flow = (struct atm_flow_data *)res.class;
395 flow = lookup_flow(sch, res.classid);
402 ATM_SKB(skb)->atm_options = flow->vcc->atm_options;
403 /*@@@ looks good ... but it's not supposed to work :-) */
404 #ifdef CONFIG_NET_CLS_ACT
409 return NET_XMIT_SUCCESS;
413 case TC_POLICE_RECLASSIFY:
417 ATM_SKB(skb)->atm_options |= ATM_ATMOPT_CLP;
423 ret = flow->q->enqueue(skb, flow->q);
428 flow->qstats.drops++;
431 sch->bstats.bytes += skb->len;
432 sch->bstats.packets++;
433 flow->bstats.bytes += skb->len;
434 flow->bstats.packets++;
436 * Okay, this may seem weird. We pretend we've dropped the packet if
437 * it goes via ATM. The reason for this is that the outer qdisc
438 * expects to be able to q->dequeue the packet later on if we return
439 * success at this place. Also, sch->q.qdisc needs to reflect whether
440 * there is a packet egligible for dequeuing or not. Note that the
441 * statistics of the outer qdisc are necessarily wrong because of all
442 * this. There's currently no correct solution for this.
444 if (flow == &p->link) {
448 tasklet_schedule(&p->task);
449 return NET_XMIT_BYPASS;
453 * Dequeue packets and send them over ATM. Note that we quite deliberately
454 * avoid checking net_device's flow control here, simply because sch_atm
455 * uses its own channels, which have nothing to do with any CLIP/LANE/or
456 * non-ATM interfaces.
459 static void sch_atm_dequeue(unsigned long data)
461 struct Qdisc *sch = (struct Qdisc *)data;
462 struct atm_qdisc_data *p = qdisc_priv(sch);
463 struct atm_flow_data *flow;
466 pr_debug("sch_atm_dequeue(sch %p,[qdisc %p])\n", sch, p);
467 for (flow = p->link.next; flow; flow = flow->next)
469 * If traffic is properly shaped, this won't generate nasty
470 * little bursts. Otherwise, it may ... (but that's okay)
472 while ((skb = flow->q->dequeue(flow->q))) {
473 if (!atm_may_send(flow->vcc, skb->truesize)) {
474 (void)flow->q->ops->requeue(skb, flow->q);
477 pr_debug("atm_tc_dequeue: sending on class %p\n", flow);
478 /* remove any LL header somebody else has attached */
479 skb_pull(skb, skb_network_offset(skb));
480 if (skb_headroom(skb) < flow->hdr_len) {
483 new = skb_realloc_headroom(skb, flow->hdr_len);
489 pr_debug("sch_atm_dequeue: ip %p, data %p\n",
490 skb_network_header(skb), skb->data);
491 ATM_SKB(skb)->vcc = flow->vcc;
492 memcpy(skb_push(skb, flow->hdr_len), flow->hdr,
494 atomic_add(skb->truesize,
495 &sk_atm(flow->vcc)->sk_wmem_alloc);
496 /* atm.atm_options are already set by atm_tc_enqueue */
497 flow->vcc->send(flow->vcc, skb);
501 static struct sk_buff *atm_tc_dequeue(struct Qdisc *sch)
503 struct atm_qdisc_data *p = qdisc_priv(sch);
506 pr_debug("atm_tc_dequeue(sch %p,[qdisc %p])\n", sch, p);
507 tasklet_schedule(&p->task);
508 skb = p->link.q->dequeue(p->link.q);
514 static int atm_tc_requeue(struct sk_buff *skb, struct Qdisc *sch)
516 struct atm_qdisc_data *p = qdisc_priv(sch);
519 pr_debug("atm_tc_requeue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);
520 ret = p->link.q->ops->requeue(skb, p->link.q);
523 sch->qstats.requeues++;
526 p->link.qstats.drops++;
531 static unsigned int atm_tc_drop(struct Qdisc *sch)
533 struct atm_qdisc_data *p = qdisc_priv(sch);
534 struct atm_flow_data *flow;
537 pr_debug("atm_tc_drop(sch %p,[qdisc %p])\n", sch, p);
538 for (flow = p->flows; flow; flow = flow->next)
539 if (flow->q->ops->drop && (len = flow->q->ops->drop(flow->q)))
544 static int atm_tc_init(struct Qdisc *sch, struct nlattr *opt)
546 struct atm_qdisc_data *p = qdisc_priv(sch);
548 pr_debug("atm_tc_init(sch %p,[qdisc %p],opt %p)\n", sch, p, opt);
550 p->link.q = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops, sch->handle);
552 p->link.q = &noop_qdisc;
553 pr_debug("atm_tc_init: link (%p) qdisc %p\n", &p->link, p->link.q);
554 p->link.filter_list = NULL;
557 p->link.classid = sch->handle;
560 tasklet_init(&p->task, sch_atm_dequeue, (unsigned long)sch);
564 static void atm_tc_reset(struct Qdisc *sch)
566 struct atm_qdisc_data *p = qdisc_priv(sch);
567 struct atm_flow_data *flow;
569 pr_debug("atm_tc_reset(sch %p,[qdisc %p])\n", sch, p);
570 for (flow = p->flows; flow; flow = flow->next)
571 qdisc_reset(flow->q);
575 static void atm_tc_destroy(struct Qdisc *sch)
577 struct atm_qdisc_data *p = qdisc_priv(sch);
578 struct atm_flow_data *flow;
580 pr_debug("atm_tc_destroy(sch %p,[qdisc %p])\n", sch, p);
582 while ((flow = p->flows)) {
583 tcf_destroy_chain(flow->filter_list);
584 flow->filter_list = NULL;
586 printk(KERN_ERR "atm_destroy: %p->ref = %d\n", flow,
588 atm_tc_put(sch, (unsigned long)flow);
589 if (p->flows == flow) {
590 printk(KERN_ERR "atm_destroy: putting flow %p didn't "
592 p->flows = flow->next; /* brute force */
596 tasklet_kill(&p->task);
599 static int atm_tc_dump_class(struct Qdisc *sch, unsigned long cl,
600 struct sk_buff *skb, struct tcmsg *tcm)
602 struct atm_qdisc_data *p = qdisc_priv(sch);
603 struct atm_flow_data *flow = (struct atm_flow_data *)cl;
604 unsigned char *b = skb_tail_pointer(skb);
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 (!find_flow(p, flow))
611 tcm->tcm_handle = flow->classid;
612 tcm->tcm_info = flow->q->handle;
613 nla = (struct nlattr *)b;
614 NLA_PUT(skb, TCA_OPTIONS, 0, NULL);
615 NLA_PUT(skb, TCA_ATM_HDR, flow->hdr_len, flow->hdr);
617 struct sockaddr_atmpvc pvc;
620 pvc.sap_family = AF_ATMPVC;
621 pvc.sap_addr.itf = flow->vcc->dev ? flow->vcc->dev->number : -1;
622 pvc.sap_addr.vpi = flow->vcc->vpi;
623 pvc.sap_addr.vci = flow->vcc->vci;
624 NLA_PUT(skb, TCA_ATM_ADDR, sizeof(pvc), &pvc);
625 state = ATM_VF2VS(flow->vcc->flags);
626 NLA_PUT(skb, TCA_ATM_STATE, sizeof(state), &state);
629 NLA_PUT(skb, TCA_ATM_EXCESS, sizeof(u32), &flow->classid);
633 NLA_PUT(skb, TCA_ATM_EXCESS, sizeof(zero), &zero);
635 nla->nla_len = skb_tail_pointer(skb) - b;
643 atm_tc_dump_class_stats(struct Qdisc *sch, unsigned long arg,
646 struct atm_flow_data *flow = (struct atm_flow_data *)arg;
648 flow->qstats.qlen = flow->q->q.qlen;
650 if (gnet_stats_copy_basic(d, &flow->bstats) < 0 ||
651 gnet_stats_copy_queue(d, &flow->qstats) < 0)
657 static int atm_tc_dump(struct Qdisc *sch, struct sk_buff *skb)
662 static const struct Qdisc_class_ops atm_class_ops = {
663 .graft = atm_tc_graft,
667 .change = atm_tc_change,
668 .delete = atm_tc_delete,
670 .tcf_chain = atm_tc_find_tcf,
671 .bind_tcf = atm_tc_bind_filter,
672 .unbind_tcf = atm_tc_put,
673 .dump = atm_tc_dump_class,
674 .dump_stats = atm_tc_dump_class_stats,
677 static struct Qdisc_ops atm_qdisc_ops __read_mostly = {
678 .cl_ops = &atm_class_ops,
680 .priv_size = sizeof(struct atm_qdisc_data),
681 .enqueue = atm_tc_enqueue,
682 .dequeue = atm_tc_dequeue,
683 .requeue = atm_tc_requeue,
686 .reset = atm_tc_reset,
687 .destroy = atm_tc_destroy,
689 .owner = THIS_MODULE,
692 static int __init atm_init(void)
694 return register_qdisc(&atm_qdisc_ops);
697 static void __exit atm_exit(void)
699 unregister_qdisc(&atm_qdisc_ops);
702 module_init(atm_init)
703 module_exit(atm_exit)
704 MODULE_LICENSE("GPL");