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 %d, 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");