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_packed 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; /* dequeue 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))
112 static struct Qdisc *atm_tc_leaf(struct Qdisc *sch, unsigned long cl)
114 struct atm_flow_data *flow = (struct atm_flow_data *)cl;
116 pr_debug("atm_tc_leaf(sch %p,flow %p)\n", sch, flow);
117 return flow ? flow->q : NULL;
120 static unsigned long atm_tc_get(struct Qdisc *sch, u32 classid)
122 struct atm_qdisc_data *p __maybe_unused = qdisc_priv(sch);
123 struct atm_flow_data *flow;
125 pr_debug("atm_tc_get(sch %p,[qdisc %p],classid %x)\n", sch, p, classid);
126 flow = lookup_flow(sch, classid);
129 pr_debug("atm_tc_get: flow %p\n", flow);
130 return (unsigned long)flow;
133 static unsigned long atm_tc_bind_filter(struct Qdisc *sch,
134 unsigned long parent, u32 classid)
136 return atm_tc_get(sch, classid);
140 * atm_tc_put handles all destructions, including the ones that are explicitly
141 * requested (atm_tc_destroy, etc.). The assumption here is that we never drop
142 * anything that still seems to be in use.
144 static void atm_tc_put(struct Qdisc *sch, unsigned long cl)
146 struct atm_qdisc_data *p = qdisc_priv(sch);
147 struct atm_flow_data *flow = (struct atm_flow_data *)cl;
148 struct atm_flow_data **prev;
150 pr_debug("atm_tc_put(sch %p,[qdisc %p],flow %p)\n", sch, p, flow);
153 pr_debug("atm_tc_put: destroying\n");
154 for (prev = &p->flows; *prev; prev = &(*prev)->next)
158 printk(KERN_CRIT "atm_tc_put: class %p not found\n", flow);
162 pr_debug("atm_tc_put: qdisc %p\n", flow->q);
163 qdisc_destroy(flow->q);
164 tcf_destroy_chain(&flow->filter_list);
166 pr_debug("atm_tc_put: f_count %ld\n",
167 file_count(flow->sock->file));
168 flow->vcc->pop = flow->old_pop;
169 sockfd_put(flow->sock);
172 atm_tc_put(sch, (unsigned long)flow->excess);
173 if (flow != &p->link)
176 * If flow == &p->link, the qdisc no longer works at this point and
177 * needs to be removed. (By the caller of atm_tc_put.)
181 static void sch_atm_pop(struct atm_vcc *vcc, struct sk_buff *skb)
183 struct atm_qdisc_data *p = VCC2FLOW(vcc)->parent;
185 pr_debug("sch_atm_pop(vcc %p,skb %p,[qdisc %p])\n", vcc, skb, p);
186 VCC2FLOW(vcc)->old_pop(vcc, skb);
187 tasklet_schedule(&p->task);
190 static const u8 llc_oui_ip[] = {
191 0xaa, /* DSAP: non-ISO */
192 0xaa, /* SSAP: non-ISO */
193 0x03, /* Ctrl: Unnumbered Information Command PDU */
194 0x00, /* OUI: EtherType */
197 }; /* Ethertype IP (0800) */
199 static const struct nla_policy atm_policy[TCA_ATM_MAX + 1] = {
200 [TCA_ATM_FD] = { .type = NLA_U32 },
201 [TCA_ATM_EXCESS] = { .type = NLA_U32 },
204 static int atm_tc_change(struct Qdisc *sch, u32 classid, u32 parent,
205 struct nlattr **tca, unsigned long *arg)
207 struct atm_qdisc_data *p = qdisc_priv(sch);
208 struct atm_flow_data *flow = (struct atm_flow_data *)*arg;
209 struct atm_flow_data *excess = NULL;
210 struct nlattr *opt = tca[TCA_OPTIONS];
211 struct nlattr *tb[TCA_ATM_MAX + 1];
213 int fd, error, hdr_len;
216 pr_debug("atm_tc_change(sch %p,[qdisc %p],classid %x,parent %x,"
217 "flow %p,opt %p)\n", sch, p, classid, parent, flow, opt);
219 * The concept of parents doesn't apply for this qdisc.
221 if (parent && parent != TC_H_ROOT && parent != sch->handle)
224 * ATM classes cannot be changed. In order to change properties of the
225 * ATM connection, that socket needs to be modified directly (via the
226 * native ATM API. In order to send a flow to a different VC, the old
227 * class needs to be removed and a new one added. (This may be changed
235 error = nla_parse_nested(tb, TCA_ATM_MAX, opt, atm_policy);
241 fd = nla_get_u32(tb[TCA_ATM_FD]);
242 pr_debug("atm_tc_change: fd %d\n", fd);
243 if (tb[TCA_ATM_HDR]) {
244 hdr_len = nla_len(tb[TCA_ATM_HDR]);
245 hdr = nla_data(tb[TCA_ATM_HDR]);
247 hdr_len = RFC1483LLC_LEN;
248 hdr = NULL; /* default LLC/SNAP for IP */
250 if (!tb[TCA_ATM_EXCESS])
253 excess = (struct atm_flow_data *)
254 atm_tc_get(sch, nla_get_u32(tb[TCA_ATM_EXCESS]));
258 pr_debug("atm_tc_change: type %d, payload %d, hdr_len %d\n",
259 opt->nla_type, nla_len(opt), hdr_len);
260 sock = sockfd_lookup(fd, &error);
262 return error; /* f_count++ */
263 pr_debug("atm_tc_change: f_count %ld\n", file_count(sock->file));
264 if (sock->ops->family != PF_ATMSVC && sock->ops->family != PF_ATMPVC) {
268 /* @@@ should check if the socket is really operational or we'll crash
271 if (TC_H_MAJ(classid ^ sch->handle)) {
272 pr_debug("atm_tc_change: classid mismatch\n");
276 if (find_flow(p, flow)) {
284 for (i = 1; i < 0x8000; i++) {
285 classid = TC_H_MAKE(sch->handle, 0x8000 | i);
286 cl = atm_tc_get(sch, classid);
292 pr_debug("atm_tc_change: new id %x\n", classid);
293 flow = kzalloc(sizeof(struct atm_flow_data) + hdr_len, GFP_KERNEL);
294 pr_debug("atm_tc_change: flow %p\n", flow);
299 flow->filter_list = NULL;
300 flow->q = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue,
301 &pfifo_qdisc_ops, classid);
303 flow->q = &noop_qdisc;
304 pr_debug("atm_tc_change: qdisc %p\n", flow->q);
306 flow->vcc = ATM_SD(sock); /* speedup */
307 flow->vcc->user_back = flow;
308 pr_debug("atm_tc_change: vcc %p\n", flow->vcc);
309 flow->old_pop = flow->vcc->pop;
311 flow->vcc->pop = sch_atm_pop;
312 flow->classid = classid;
314 flow->excess = excess;
315 flow->next = p->link.next;
317 flow->hdr_len = hdr_len;
319 memcpy(flow->hdr, hdr, hdr_len);
321 memcpy(flow->hdr, llc_oui_ip, sizeof(llc_oui_ip));
322 *arg = (unsigned long)flow;
326 atm_tc_put(sch, (unsigned long)excess);
331 static int atm_tc_delete(struct Qdisc *sch, unsigned long arg)
333 struct atm_qdisc_data *p = qdisc_priv(sch);
334 struct atm_flow_data *flow = (struct atm_flow_data *)arg;
336 pr_debug("atm_tc_delete(sch %p,[qdisc %p],flow %p)\n", sch, p, flow);
337 if (!find_flow(qdisc_priv(sch), flow))
339 if (flow->filter_list || flow == &p->link)
342 * Reference count must be 2: one for "keepalive" (set at class
343 * creation), and one for the reference held when calling delete.
346 printk(KERN_ERR "atm_tc_delete: flow->ref == %d\n", flow->ref);
350 return -EBUSY; /* catch references via excess, etc. */
351 atm_tc_put(sch, arg);
355 static void atm_tc_walk(struct Qdisc *sch, struct qdisc_walker *walker)
357 struct atm_qdisc_data *p = qdisc_priv(sch);
358 struct atm_flow_data *flow;
360 pr_debug("atm_tc_walk(sch %p,[qdisc %p],walker %p)\n", sch, p, walker);
363 for (flow = p->flows; flow; flow = flow->next) {
364 if (walker->count >= walker->skip)
365 if (walker->fn(sch, (unsigned long)flow, walker) < 0) {
373 static struct tcf_proto **atm_tc_find_tcf(struct Qdisc *sch, unsigned long cl)
375 struct atm_qdisc_data *p = qdisc_priv(sch);
376 struct atm_flow_data *flow = (struct atm_flow_data *)cl;
378 pr_debug("atm_tc_find_tcf(sch %p,[qdisc %p],flow %p)\n", sch, p, flow);
379 return flow ? &flow->filter_list : &p->link.filter_list;
382 /* --------------------------- Qdisc operations ---------------------------- */
384 static int atm_tc_enqueue(struct sk_buff *skb, struct Qdisc *sch)
386 struct atm_qdisc_data *p = qdisc_priv(sch);
387 struct atm_flow_data *flow = NULL; /* @@@ */
388 struct tcf_result res;
390 int ret = NET_XMIT_POLICED;
392 pr_debug("atm_tc_enqueue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);
393 result = TC_POLICE_OK; /* be nice to gcc */
394 if (TC_H_MAJ(skb->priority) != sch->handle ||
395 !(flow = (struct atm_flow_data *)atm_tc_get(sch, skb->priority)))
396 for (flow = p->flows; flow; flow = flow->next)
397 if (flow->filter_list) {
398 result = tc_classify_compat(skb,
403 flow = (struct atm_flow_data *)res.class;
405 flow = lookup_flow(sch, res.classid);
412 ATM_SKB(skb)->atm_options = flow->vcc->atm_options;
413 /*@@@ looks good ... but it's not supposed to work :-) */
414 #ifdef CONFIG_NET_CLS_ACT
419 return NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
423 case TC_POLICE_RECLASSIFY:
427 ATM_SKB(skb)->atm_options |= ATM_ATMOPT_CLP;
433 ret = qdisc_enqueue(skb, flow->q);
436 if (net_xmit_drop_count(ret)) {
439 flow->qstats.drops++;
443 sch->bstats.bytes += qdisc_pkt_len(skb);
444 sch->bstats.packets++;
445 flow->bstats.bytes += qdisc_pkt_len(skb);
446 flow->bstats.packets++;
448 * Okay, this may seem weird. We pretend we've dropped the packet if
449 * it goes via ATM. The reason for this is that the outer qdisc
450 * expects to be able to q->dequeue the packet later on if we return
451 * success at this place. Also, sch->q.qdisc needs to reflect whether
452 * there is a packet egligible for dequeuing or not. Note that the
453 * statistics of the outer qdisc are necessarily wrong because of all
454 * this. There's currently no correct solution for this.
456 if (flow == &p->link) {
460 tasklet_schedule(&p->task);
461 return NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
465 * Dequeue packets and send them over ATM. Note that we quite deliberately
466 * avoid checking net_device's flow control here, simply because sch_atm
467 * uses its own channels, which have nothing to do with any CLIP/LANE/or
468 * non-ATM interfaces.
471 static void sch_atm_dequeue(unsigned long data)
473 struct Qdisc *sch = (struct Qdisc *)data;
474 struct atm_qdisc_data *p = qdisc_priv(sch);
475 struct atm_flow_data *flow;
478 pr_debug("sch_atm_dequeue(sch %p,[qdisc %p])\n", sch, p);
479 for (flow = p->link.next; flow; flow = flow->next)
481 * If traffic is properly shaped, this won't generate nasty
482 * little bursts. Otherwise, it may ... (but that's okay)
484 while ((skb = flow->q->ops->peek(flow->q))) {
485 if (!atm_may_send(flow->vcc, skb->truesize))
488 skb = qdisc_dequeue_peeked(flow->q);
492 pr_debug("atm_tc_dequeue: sending on class %p\n", flow);
493 /* remove any LL header somebody else has attached */
494 skb_pull(skb, skb_network_offset(skb));
495 if (skb_headroom(skb) < flow->hdr_len) {
498 new = skb_realloc_headroom(skb, flow->hdr_len);
504 pr_debug("sch_atm_dequeue: ip %p, data %p\n",
505 skb_network_header(skb), skb->data);
506 ATM_SKB(skb)->vcc = flow->vcc;
507 memcpy(skb_push(skb, flow->hdr_len), flow->hdr,
509 atomic_add(skb->truesize,
510 &sk_atm(flow->vcc)->sk_wmem_alloc);
511 /* atm.atm_options are already set by atm_tc_enqueue */
512 flow->vcc->send(flow->vcc, skb);
516 static struct sk_buff *atm_tc_dequeue(struct Qdisc *sch)
518 struct atm_qdisc_data *p = qdisc_priv(sch);
521 pr_debug("atm_tc_dequeue(sch %p,[qdisc %p])\n", sch, p);
522 tasklet_schedule(&p->task);
523 skb = qdisc_dequeue_peeked(p->link.q);
529 static struct sk_buff *atm_tc_peek(struct Qdisc *sch)
531 struct atm_qdisc_data *p = qdisc_priv(sch);
533 pr_debug("atm_tc_peek(sch %p,[qdisc %p])\n", sch, p);
535 return p->link.q->ops->peek(p->link.q);
538 static unsigned int atm_tc_drop(struct Qdisc *sch)
540 struct atm_qdisc_data *p = qdisc_priv(sch);
541 struct atm_flow_data *flow;
544 pr_debug("atm_tc_drop(sch %p,[qdisc %p])\n", sch, p);
545 for (flow = p->flows; flow; flow = flow->next)
546 if (flow->q->ops->drop && (len = flow->q->ops->drop(flow->q)))
551 static int atm_tc_init(struct Qdisc *sch, struct nlattr *opt)
553 struct atm_qdisc_data *p = qdisc_priv(sch);
555 pr_debug("atm_tc_init(sch %p,[qdisc %p],opt %p)\n", sch, p, opt);
557 p->link.q = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue,
558 &pfifo_qdisc_ops, sch->handle);
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;
565 p->link.classid = sch->handle;
568 tasklet_init(&p->task, sch_atm_dequeue, (unsigned long)sch);
572 static void atm_tc_reset(struct Qdisc *sch)
574 struct atm_qdisc_data *p = qdisc_priv(sch);
575 struct atm_flow_data *flow;
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);
583 static void atm_tc_destroy(struct Qdisc *sch)
585 struct atm_qdisc_data *p = qdisc_priv(sch);
586 struct atm_flow_data *flow;
588 pr_debug("atm_tc_destroy(sch %p,[qdisc %p])\n", sch, p);
589 for (flow = p->flows; flow; flow = flow->next)
590 tcf_destroy_chain(&flow->filter_list);
593 while ((flow = p->flows)) {
595 printk(KERN_ERR "atm_destroy: %p->ref = %d\n", flow,
597 atm_tc_put(sch, (unsigned long)flow);
598 if (p->flows == flow) {
599 printk(KERN_ERR "atm_destroy: putting flow %p didn't "
601 p->flows = flow->next; /* brute force */
605 tasklet_kill(&p->task);
608 static int atm_tc_dump_class(struct Qdisc *sch, unsigned long cl,
609 struct sk_buff *skb, struct tcmsg *tcm)
611 struct atm_qdisc_data *p = qdisc_priv(sch);
612 struct atm_flow_data *flow = (struct atm_flow_data *)cl;
615 pr_debug("atm_tc_dump_class(sch %p,[qdisc %p],flow %p,skb %p,tcm %p)\n",
616 sch, p, flow, skb, tcm);
617 if (!find_flow(p, flow))
619 tcm->tcm_handle = flow->classid;
620 tcm->tcm_info = flow->q->handle;
622 nest = nla_nest_start(skb, TCA_OPTIONS);
624 goto nla_put_failure;
626 NLA_PUT(skb, TCA_ATM_HDR, flow->hdr_len, flow->hdr);
628 struct sockaddr_atmpvc pvc;
631 pvc.sap_family = AF_ATMPVC;
632 pvc.sap_addr.itf = flow->vcc->dev ? flow->vcc->dev->number : -1;
633 pvc.sap_addr.vpi = flow->vcc->vpi;
634 pvc.sap_addr.vci = flow->vcc->vci;
635 NLA_PUT(skb, TCA_ATM_ADDR, sizeof(pvc), &pvc);
636 state = ATM_VF2VS(flow->vcc->flags);
637 NLA_PUT_U32(skb, TCA_ATM_STATE, state);
640 NLA_PUT_U32(skb, TCA_ATM_EXCESS, flow->classid);
642 NLA_PUT_U32(skb, TCA_ATM_EXCESS, 0);
645 nla_nest_end(skb, nest);
649 nla_nest_cancel(skb, nest);
653 atm_tc_dump_class_stats(struct Qdisc *sch, unsigned long arg,
656 struct atm_flow_data *flow = (struct atm_flow_data *)arg;
658 flow->qstats.qlen = flow->q->q.qlen;
660 if (gnet_stats_copy_basic(d, &flow->bstats) < 0 ||
661 gnet_stats_copy_queue(d, &flow->qstats) < 0)
667 static int atm_tc_dump(struct Qdisc *sch, struct sk_buff *skb)
672 static const struct Qdisc_class_ops atm_class_ops = {
673 .graft = atm_tc_graft,
677 .change = atm_tc_change,
678 .delete = atm_tc_delete,
680 .tcf_chain = atm_tc_find_tcf,
681 .bind_tcf = atm_tc_bind_filter,
682 .unbind_tcf = atm_tc_put,
683 .dump = atm_tc_dump_class,
684 .dump_stats = atm_tc_dump_class_stats,
687 static struct Qdisc_ops atm_qdisc_ops __read_mostly = {
688 .cl_ops = &atm_class_ops,
690 .priv_size = sizeof(struct atm_qdisc_data),
691 .enqueue = atm_tc_enqueue,
692 .dequeue = atm_tc_dequeue,
696 .reset = atm_tc_reset,
697 .destroy = atm_tc_destroy,
699 .owner = THIS_MODULE,
702 static int __init atm_init(void)
704 return register_qdisc(&atm_qdisc_ops);
707 static void __exit atm_exit(void)
709 unregister_qdisc(&atm_qdisc_ops);
712 module_init(atm_init)
713 module_exit(atm_exit)
714 MODULE_LICENSE("GPL");