Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * net/sched/sch_sfq.c Stochastic Fairness Queueing discipline. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
6 | * as published by the Free Software Foundation; either version | |
7 | * 2 of the License, or (at your option) any later version. | |
8 | * | |
9 | * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> | |
10 | */ | |
11 | ||
1da177e4 | 12 | #include <linux/module.h> |
1da177e4 LT |
13 | #include <linux/types.h> |
14 | #include <linux/kernel.h> | |
15 | #include <linux/jiffies.h> | |
16 | #include <linux/string.h> | |
1da177e4 LT |
17 | #include <linux/in.h> |
18 | #include <linux/errno.h> | |
1da177e4 | 19 | #include <linux/init.h> |
1da177e4 | 20 | #include <linux/ipv6.h> |
1da177e4 | 21 | #include <linux/skbuff.h> |
32740ddc | 22 | #include <linux/jhash.h> |
0ba48053 PM |
23 | #include <net/ip.h> |
24 | #include <net/netlink.h> | |
1da177e4 LT |
25 | #include <net/pkt_sched.h> |
26 | ||
27 | ||
28 | /* Stochastic Fairness Queuing algorithm. | |
29 | ======================================= | |
30 | ||
31 | Source: | |
32 | Paul E. McKenney "Stochastic Fairness Queuing", | |
33 | IEEE INFOCOMM'90 Proceedings, San Francisco, 1990. | |
34 | ||
35 | Paul E. McKenney "Stochastic Fairness Queuing", | |
36 | "Interworking: Research and Experience", v.2, 1991, p.113-131. | |
37 | ||
38 | ||
39 | See also: | |
40 | M. Shreedhar and George Varghese "Efficient Fair | |
41 | Queuing using Deficit Round Robin", Proc. SIGCOMM 95. | |
42 | ||
43 | ||
10297b99 | 44 | This is not the thing that is usually called (W)FQ nowadays. |
1da177e4 LT |
45 | It does not use any timestamp mechanism, but instead |
46 | processes queues in round-robin order. | |
47 | ||
48 | ADVANTAGE: | |
49 | ||
50 | - It is very cheap. Both CPU and memory requirements are minimal. | |
51 | ||
52 | DRAWBACKS: | |
53 | ||
10297b99 | 54 | - "Stochastic" -> It is not 100% fair. |
1da177e4 LT |
55 | When hash collisions occur, several flows are considered as one. |
56 | ||
57 | - "Round-robin" -> It introduces larger delays than virtual clock | |
58 | based schemes, and should not be used for isolating interactive | |
59 | traffic from non-interactive. It means, that this scheduler | |
60 | should be used as leaf of CBQ or P3, which put interactive traffic | |
61 | to higher priority band. | |
62 | ||
63 | We still need true WFQ for top level CSZ, but using WFQ | |
64 | for the best effort traffic is absolutely pointless: | |
65 | SFQ is superior for this purpose. | |
66 | ||
67 | IMPLEMENTATION: | |
68 | This implementation limits maximal queue length to 128; | |
69 | maximal mtu to 2^15-1; number of hash buckets to 1024. | |
70 | The only goal of this restrictions was that all data | |
71 | fit into one 4K page :-). Struct sfq_sched_data is | |
72 | organized in anti-cache manner: all the data for a bucket | |
73 | are scattered over different locations. This is not good, | |
74 | but it allowed me to put it into 4K. | |
75 | ||
76 | It is easy to increase these values, but not in flight. */ | |
77 | ||
78 | #define SFQ_DEPTH 128 | |
79 | #define SFQ_HASH_DIVISOR 1024 | |
80 | ||
81 | /* This type should contain at least SFQ_DEPTH*2 values */ | |
82 | typedef unsigned char sfq_index; | |
83 | ||
84 | struct sfq_head | |
85 | { | |
86 | sfq_index next; | |
87 | sfq_index prev; | |
88 | }; | |
89 | ||
90 | struct sfq_sched_data | |
91 | { | |
92 | /* Parameters */ | |
93 | int perturb_period; | |
94 | unsigned quantum; /* Allotment per round: MUST BE >= MTU */ | |
95 | int limit; | |
96 | ||
97 | /* Variables */ | |
7d2681a6 | 98 | struct tcf_proto *filter_list; |
1da177e4 | 99 | struct timer_list perturb_timer; |
32740ddc | 100 | u32 perturbation; |
1da177e4 LT |
101 | sfq_index tail; /* Index of current slot in round */ |
102 | sfq_index max_depth; /* Maximal depth */ | |
103 | ||
104 | sfq_index ht[SFQ_HASH_DIVISOR]; /* Hash table */ | |
105 | sfq_index next[SFQ_DEPTH]; /* Active slots link */ | |
106 | short allot[SFQ_DEPTH]; /* Current allotment per slot */ | |
107 | unsigned short hash[SFQ_DEPTH]; /* Hash value indexed by slots */ | |
108 | struct sk_buff_head qs[SFQ_DEPTH]; /* Slot queue */ | |
109 | struct sfq_head dep[SFQ_DEPTH*2]; /* Linked list of slots, indexed by depth */ | |
110 | }; | |
111 | ||
112 | static __inline__ unsigned sfq_fold_hash(struct sfq_sched_data *q, u32 h, u32 h1) | |
113 | { | |
32740ddc | 114 | return jhash_2words(h, h1, q->perturbation) & (SFQ_HASH_DIVISOR - 1); |
1da177e4 LT |
115 | } |
116 | ||
117 | static unsigned sfq_hash(struct sfq_sched_data *q, struct sk_buff *skb) | |
118 | { | |
119 | u32 h, h2; | |
120 | ||
121 | switch (skb->protocol) { | |
60678040 | 122 | case htons(ETH_P_IP): |
1da177e4 | 123 | { |
eddc9ec5 | 124 | const struct iphdr *iph = ip_hdr(skb); |
1da177e4 | 125 | h = iph->daddr; |
6f9e98f7 | 126 | h2 = iph->saddr ^ iph->protocol; |
1da177e4 LT |
127 | if (!(iph->frag_off&htons(IP_MF|IP_OFFSET)) && |
128 | (iph->protocol == IPPROTO_TCP || | |
129 | iph->protocol == IPPROTO_UDP || | |
a8d0f952 | 130 | iph->protocol == IPPROTO_UDPLITE || |
ae82af54 PM |
131 | iph->protocol == IPPROTO_SCTP || |
132 | iph->protocol == IPPROTO_DCCP || | |
1da177e4 LT |
133 | iph->protocol == IPPROTO_ESP)) |
134 | h2 ^= *(((u32*)iph) + iph->ihl); | |
135 | break; | |
136 | } | |
60678040 | 137 | case htons(ETH_P_IPV6): |
1da177e4 | 138 | { |
0660e03f | 139 | struct ipv6hdr *iph = ipv6_hdr(skb); |
1da177e4 | 140 | h = iph->daddr.s6_addr32[3]; |
6f9e98f7 | 141 | h2 = iph->saddr.s6_addr32[3] ^ iph->nexthdr; |
1da177e4 LT |
142 | if (iph->nexthdr == IPPROTO_TCP || |
143 | iph->nexthdr == IPPROTO_UDP || | |
a8d0f952 | 144 | iph->nexthdr == IPPROTO_UDPLITE || |
ae82af54 PM |
145 | iph->nexthdr == IPPROTO_SCTP || |
146 | iph->nexthdr == IPPROTO_DCCP || | |
1da177e4 LT |
147 | iph->nexthdr == IPPROTO_ESP) |
148 | h2 ^= *(u32*)&iph[1]; | |
149 | break; | |
150 | } | |
151 | default: | |
6f9e98f7 SH |
152 | h = (unsigned long)skb->dst ^ skb->protocol; |
153 | h2 = (unsigned long)skb->sk; | |
1da177e4 | 154 | } |
6f9e98f7 | 155 | |
1da177e4 LT |
156 | return sfq_fold_hash(q, h, h2); |
157 | } | |
158 | ||
7d2681a6 PM |
159 | static unsigned int sfq_classify(struct sk_buff *skb, struct Qdisc *sch, |
160 | int *qerr) | |
161 | { | |
162 | struct sfq_sched_data *q = qdisc_priv(sch); | |
163 | struct tcf_result res; | |
164 | int result; | |
165 | ||
166 | if (TC_H_MAJ(skb->priority) == sch->handle && | |
167 | TC_H_MIN(skb->priority) > 0 && | |
168 | TC_H_MIN(skb->priority) <= SFQ_HASH_DIVISOR) | |
169 | return TC_H_MIN(skb->priority); | |
170 | ||
171 | if (!q->filter_list) | |
172 | return sfq_hash(q, skb) + 1; | |
173 | ||
c27f339a | 174 | *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; |
7d2681a6 PM |
175 | result = tc_classify(skb, q->filter_list, &res); |
176 | if (result >= 0) { | |
177 | #ifdef CONFIG_NET_CLS_ACT | |
178 | switch (result) { | |
179 | case TC_ACT_STOLEN: | |
180 | case TC_ACT_QUEUED: | |
378a2f09 | 181 | *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN; |
7d2681a6 PM |
182 | case TC_ACT_SHOT: |
183 | return 0; | |
184 | } | |
185 | #endif | |
186 | if (TC_H_MIN(res.classid) <= SFQ_HASH_DIVISOR) | |
187 | return TC_H_MIN(res.classid); | |
188 | } | |
189 | return 0; | |
190 | } | |
191 | ||
1da177e4 LT |
192 | static inline void sfq_link(struct sfq_sched_data *q, sfq_index x) |
193 | { | |
194 | sfq_index p, n; | |
195 | int d = q->qs[x].qlen + SFQ_DEPTH; | |
196 | ||
197 | p = d; | |
198 | n = q->dep[d].next; | |
199 | q->dep[x].next = n; | |
200 | q->dep[x].prev = p; | |
201 | q->dep[p].next = q->dep[n].prev = x; | |
202 | } | |
203 | ||
204 | static inline void sfq_dec(struct sfq_sched_data *q, sfq_index x) | |
205 | { | |
206 | sfq_index p, n; | |
207 | ||
208 | n = q->dep[x].next; | |
209 | p = q->dep[x].prev; | |
210 | q->dep[p].next = n; | |
211 | q->dep[n].prev = p; | |
212 | ||
213 | if (n == p && q->max_depth == q->qs[x].qlen + 1) | |
214 | q->max_depth--; | |
215 | ||
216 | sfq_link(q, x); | |
217 | } | |
218 | ||
219 | static inline void sfq_inc(struct sfq_sched_data *q, sfq_index x) | |
220 | { | |
221 | sfq_index p, n; | |
222 | int d; | |
223 | ||
224 | n = q->dep[x].next; | |
225 | p = q->dep[x].prev; | |
226 | q->dep[p].next = n; | |
227 | q->dep[n].prev = p; | |
228 | d = q->qs[x].qlen; | |
229 | if (q->max_depth < d) | |
230 | q->max_depth = d; | |
231 | ||
232 | sfq_link(q, x); | |
233 | } | |
234 | ||
235 | static unsigned int sfq_drop(struct Qdisc *sch) | |
236 | { | |
237 | struct sfq_sched_data *q = qdisc_priv(sch); | |
238 | sfq_index d = q->max_depth; | |
239 | struct sk_buff *skb; | |
240 | unsigned int len; | |
241 | ||
242 | /* Queue is full! Find the longest slot and | |
243 | drop a packet from it */ | |
244 | ||
245 | if (d > 1) { | |
6f9e98f7 | 246 | sfq_index x = q->dep[d + SFQ_DEPTH].next; |
1da177e4 | 247 | skb = q->qs[x].prev; |
0abf77e5 | 248 | len = qdisc_pkt_len(skb); |
1da177e4 LT |
249 | __skb_unlink(skb, &q->qs[x]); |
250 | kfree_skb(skb); | |
251 | sfq_dec(q, x); | |
252 | sch->q.qlen--; | |
253 | sch->qstats.drops++; | |
f5539eb8 | 254 | sch->qstats.backlog -= len; |
1da177e4 LT |
255 | return len; |
256 | } | |
257 | ||
258 | if (d == 1) { | |
259 | /* It is difficult to believe, but ALL THE SLOTS HAVE LENGTH 1. */ | |
260 | d = q->next[q->tail]; | |
261 | q->next[q->tail] = q->next[d]; | |
262 | q->allot[q->next[d]] += q->quantum; | |
263 | skb = q->qs[d].prev; | |
0abf77e5 | 264 | len = qdisc_pkt_len(skb); |
1da177e4 LT |
265 | __skb_unlink(skb, &q->qs[d]); |
266 | kfree_skb(skb); | |
267 | sfq_dec(q, d); | |
268 | sch->q.qlen--; | |
269 | q->ht[q->hash[d]] = SFQ_DEPTH; | |
270 | sch->qstats.drops++; | |
f5539eb8 | 271 | sch->qstats.backlog -= len; |
1da177e4 LT |
272 | return len; |
273 | } | |
274 | ||
275 | return 0; | |
276 | } | |
277 | ||
278 | static int | |
6f9e98f7 | 279 | sfq_enqueue(struct sk_buff *skb, struct Qdisc *sch) |
1da177e4 LT |
280 | { |
281 | struct sfq_sched_data *q = qdisc_priv(sch); | |
7d2681a6 | 282 | unsigned int hash; |
1da177e4 | 283 | sfq_index x; |
7d2681a6 PM |
284 | int ret; |
285 | ||
286 | hash = sfq_classify(skb, sch, &ret); | |
287 | if (hash == 0) { | |
c27f339a | 288 | if (ret & __NET_XMIT_BYPASS) |
7d2681a6 PM |
289 | sch->qstats.drops++; |
290 | kfree_skb(skb); | |
291 | return ret; | |
292 | } | |
293 | hash--; | |
1da177e4 LT |
294 | |
295 | x = q->ht[hash]; | |
296 | if (x == SFQ_DEPTH) { | |
297 | q->ht[hash] = x = q->dep[SFQ_DEPTH].next; | |
298 | q->hash[x] = hash; | |
299 | } | |
6f9e98f7 | 300 | |
32740ddc AK |
301 | /* If selected queue has length q->limit, this means that |
302 | * all another queues are empty and that we do simple tail drop, | |
303 | * i.e. drop _this_ packet. | |
304 | */ | |
305 | if (q->qs[x].qlen >= q->limit) | |
306 | return qdisc_drop(skb, sch); | |
307 | ||
0abf77e5 | 308 | sch->qstats.backlog += qdisc_pkt_len(skb); |
1da177e4 LT |
309 | __skb_queue_tail(&q->qs[x], skb); |
310 | sfq_inc(q, x); | |
311 | if (q->qs[x].qlen == 1) { /* The flow is new */ | |
312 | if (q->tail == SFQ_DEPTH) { /* It is the first flow */ | |
313 | q->tail = x; | |
314 | q->next[x] = x; | |
315 | q->allot[x] = q->quantum; | |
316 | } else { | |
317 | q->next[x] = q->next[q->tail]; | |
318 | q->next[q->tail] = x; | |
319 | q->tail = x; | |
320 | } | |
321 | } | |
5588b40d | 322 | if (++sch->q.qlen <= q->limit) { |
0abf77e5 | 323 | sch->bstats.bytes += qdisc_pkt_len(skb); |
1da177e4 LT |
324 | sch->bstats.packets++; |
325 | return 0; | |
326 | } | |
327 | ||
328 | sfq_drop(sch); | |
329 | return NET_XMIT_CN; | |
330 | } | |
331 | ||
48a8f519 PM |
332 | static struct sk_buff * |
333 | sfq_peek(struct Qdisc *sch) | |
334 | { | |
335 | struct sfq_sched_data *q = qdisc_priv(sch); | |
336 | sfq_index a; | |
1da177e4 | 337 | |
48a8f519 PM |
338 | /* No active slots */ |
339 | if (q->tail == SFQ_DEPTH) | |
340 | return NULL; | |
1da177e4 | 341 | |
48a8f519 PM |
342 | a = q->next[q->tail]; |
343 | return skb_peek(&q->qs[a]); | |
344 | } | |
1da177e4 LT |
345 | |
346 | static struct sk_buff * | |
6f9e98f7 | 347 | sfq_dequeue(struct Qdisc *sch) |
1da177e4 LT |
348 | { |
349 | struct sfq_sched_data *q = qdisc_priv(sch); | |
350 | struct sk_buff *skb; | |
351 | sfq_index a, old_a; | |
352 | ||
353 | /* No active slots */ | |
354 | if (q->tail == SFQ_DEPTH) | |
355 | return NULL; | |
356 | ||
357 | a = old_a = q->next[q->tail]; | |
358 | ||
359 | /* Grab packet */ | |
360 | skb = __skb_dequeue(&q->qs[a]); | |
361 | sfq_dec(q, a); | |
362 | sch->q.qlen--; | |
0abf77e5 | 363 | sch->qstats.backlog -= qdisc_pkt_len(skb); |
1da177e4 LT |
364 | |
365 | /* Is the slot empty? */ | |
366 | if (q->qs[a].qlen == 0) { | |
367 | q->ht[q->hash[a]] = SFQ_DEPTH; | |
368 | a = q->next[a]; | |
369 | if (a == old_a) { | |
370 | q->tail = SFQ_DEPTH; | |
371 | return skb; | |
372 | } | |
373 | q->next[q->tail] = a; | |
374 | q->allot[a] += q->quantum; | |
0abf77e5 | 375 | } else if ((q->allot[a] -= qdisc_pkt_len(skb)) <= 0) { |
1da177e4 LT |
376 | q->tail = a; |
377 | a = q->next[a]; | |
378 | q->allot[a] += q->quantum; | |
379 | } | |
380 | return skb; | |
381 | } | |
382 | ||
383 | static void | |
6f9e98f7 | 384 | sfq_reset(struct Qdisc *sch) |
1da177e4 LT |
385 | { |
386 | struct sk_buff *skb; | |
387 | ||
388 | while ((skb = sfq_dequeue(sch)) != NULL) | |
389 | kfree_skb(skb); | |
390 | } | |
391 | ||
392 | static void sfq_perturbation(unsigned long arg) | |
393 | { | |
6f9e98f7 | 394 | struct Qdisc *sch = (struct Qdisc *)arg; |
1da177e4 LT |
395 | struct sfq_sched_data *q = qdisc_priv(sch); |
396 | ||
d46f8dd8 | 397 | q->perturbation = net_random(); |
1da177e4 | 398 | |
32740ddc AK |
399 | if (q->perturb_period) |
400 | mod_timer(&q->perturb_timer, jiffies + q->perturb_period); | |
1da177e4 LT |
401 | } |
402 | ||
1e90474c | 403 | static int sfq_change(struct Qdisc *sch, struct nlattr *opt) |
1da177e4 LT |
404 | { |
405 | struct sfq_sched_data *q = qdisc_priv(sch); | |
1e90474c | 406 | struct tc_sfq_qopt *ctl = nla_data(opt); |
5e50da01 | 407 | unsigned int qlen; |
1da177e4 | 408 | |
1e90474c | 409 | if (opt->nla_len < nla_attr_size(sizeof(*ctl))) |
1da177e4 LT |
410 | return -EINVAL; |
411 | ||
412 | sch_tree_lock(sch); | |
5ce2d488 | 413 | q->quantum = ctl->quantum ? : psched_mtu(qdisc_dev(sch)); |
6f9e98f7 | 414 | q->perturb_period = ctl->perturb_period * HZ; |
1da177e4 | 415 | if (ctl->limit) |
32740ddc | 416 | q->limit = min_t(u32, ctl->limit, SFQ_DEPTH - 1); |
1da177e4 | 417 | |
5e50da01 | 418 | qlen = sch->q.qlen; |
5588b40d | 419 | while (sch->q.qlen > q->limit) |
1da177e4 | 420 | sfq_drop(sch); |
5e50da01 | 421 | qdisc_tree_decrease_qlen(sch, qlen - sch->q.qlen); |
1da177e4 LT |
422 | |
423 | del_timer(&q->perturb_timer); | |
424 | if (q->perturb_period) { | |
32740ddc | 425 | mod_timer(&q->perturb_timer, jiffies + q->perturb_period); |
d46f8dd8 | 426 | q->perturbation = net_random(); |
1da177e4 LT |
427 | } |
428 | sch_tree_unlock(sch); | |
429 | return 0; | |
430 | } | |
431 | ||
1e90474c | 432 | static int sfq_init(struct Qdisc *sch, struct nlattr *opt) |
1da177e4 LT |
433 | { |
434 | struct sfq_sched_data *q = qdisc_priv(sch); | |
435 | int i; | |
436 | ||
d3e99483 SH |
437 | q->perturb_timer.function = sfq_perturbation; |
438 | q->perturb_timer.data = (unsigned long)sch;; | |
439 | init_timer_deferrable(&q->perturb_timer); | |
1da177e4 | 440 | |
6f9e98f7 | 441 | for (i = 0; i < SFQ_HASH_DIVISOR; i++) |
1da177e4 | 442 | q->ht[i] = SFQ_DEPTH; |
6f9e98f7 SH |
443 | |
444 | for (i = 0; i < SFQ_DEPTH; i++) { | |
1da177e4 | 445 | skb_queue_head_init(&q->qs[i]); |
6f9e98f7 SH |
446 | q->dep[i + SFQ_DEPTH].next = i + SFQ_DEPTH; |
447 | q->dep[i + SFQ_DEPTH].prev = i + SFQ_DEPTH; | |
1da177e4 | 448 | } |
6f9e98f7 | 449 | |
32740ddc | 450 | q->limit = SFQ_DEPTH - 1; |
1da177e4 LT |
451 | q->max_depth = 0; |
452 | q->tail = SFQ_DEPTH; | |
453 | if (opt == NULL) { | |
5ce2d488 | 454 | q->quantum = psched_mtu(qdisc_dev(sch)); |
1da177e4 | 455 | q->perturb_period = 0; |
d46f8dd8 | 456 | q->perturbation = net_random(); |
1da177e4 LT |
457 | } else { |
458 | int err = sfq_change(sch, opt); | |
459 | if (err) | |
460 | return err; | |
461 | } | |
6f9e98f7 SH |
462 | |
463 | for (i = 0; i < SFQ_DEPTH; i++) | |
1da177e4 LT |
464 | sfq_link(q, i); |
465 | return 0; | |
466 | } | |
467 | ||
468 | static void sfq_destroy(struct Qdisc *sch) | |
469 | { | |
470 | struct sfq_sched_data *q = qdisc_priv(sch); | |
7d2681a6 | 471 | |
ff31ab56 | 472 | tcf_destroy_chain(&q->filter_list); |
980c478d JP |
473 | q->perturb_period = 0; |
474 | del_timer_sync(&q->perturb_timer); | |
1da177e4 LT |
475 | } |
476 | ||
477 | static int sfq_dump(struct Qdisc *sch, struct sk_buff *skb) | |
478 | { | |
479 | struct sfq_sched_data *q = qdisc_priv(sch); | |
27a884dc | 480 | unsigned char *b = skb_tail_pointer(skb); |
1da177e4 LT |
481 | struct tc_sfq_qopt opt; |
482 | ||
483 | opt.quantum = q->quantum; | |
6f9e98f7 | 484 | opt.perturb_period = q->perturb_period / HZ; |
1da177e4 LT |
485 | |
486 | opt.limit = q->limit; | |
487 | opt.divisor = SFQ_HASH_DIVISOR; | |
cdec7e50 | 488 | opt.flows = q->limit; |
1da177e4 | 489 | |
1e90474c | 490 | NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt); |
1da177e4 LT |
491 | |
492 | return skb->len; | |
493 | ||
1e90474c | 494 | nla_put_failure: |
dc5fc579 | 495 | nlmsg_trim(skb, b); |
1da177e4 LT |
496 | return -1; |
497 | } | |
498 | ||
7d2681a6 PM |
499 | static int sfq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, |
500 | struct nlattr **tca, unsigned long *arg) | |
501 | { | |
502 | return -EOPNOTSUPP; | |
503 | } | |
504 | ||
505 | static unsigned long sfq_get(struct Qdisc *sch, u32 classid) | |
506 | { | |
507 | return 0; | |
508 | } | |
509 | ||
510 | static struct tcf_proto **sfq_find_tcf(struct Qdisc *sch, unsigned long cl) | |
511 | { | |
512 | struct sfq_sched_data *q = qdisc_priv(sch); | |
513 | ||
514 | if (cl) | |
515 | return NULL; | |
516 | return &q->filter_list; | |
517 | } | |
518 | ||
94de78d1 PM |
519 | static int sfq_dump_class(struct Qdisc *sch, unsigned long cl, |
520 | struct sk_buff *skb, struct tcmsg *tcm) | |
521 | { | |
522 | tcm->tcm_handle |= TC_H_MIN(cl); | |
523 | return 0; | |
524 | } | |
525 | ||
526 | static int sfq_dump_class_stats(struct Qdisc *sch, unsigned long cl, | |
527 | struct gnet_dump *d) | |
528 | { | |
529 | struct sfq_sched_data *q = qdisc_priv(sch); | |
530 | sfq_index idx = q->ht[cl-1]; | |
531 | struct gnet_stats_queue qs = { .qlen = q->qs[idx].qlen }; | |
532 | struct tc_sfq_xstats xstats = { .allot = q->allot[idx] }; | |
533 | ||
534 | if (gnet_stats_copy_queue(d, &qs) < 0) | |
535 | return -1; | |
536 | return gnet_stats_copy_app(d, &xstats, sizeof(xstats)); | |
537 | } | |
538 | ||
7d2681a6 PM |
539 | static void sfq_walk(struct Qdisc *sch, struct qdisc_walker *arg) |
540 | { | |
94de78d1 PM |
541 | struct sfq_sched_data *q = qdisc_priv(sch); |
542 | unsigned int i; | |
543 | ||
544 | if (arg->stop) | |
545 | return; | |
546 | ||
547 | for (i = 0; i < SFQ_HASH_DIVISOR; i++) { | |
548 | if (q->ht[i] == SFQ_DEPTH || | |
549 | arg->count < arg->skip) { | |
550 | arg->count++; | |
551 | continue; | |
552 | } | |
553 | if (arg->fn(sch, i + 1, arg) < 0) { | |
554 | arg->stop = 1; | |
555 | break; | |
556 | } | |
557 | arg->count++; | |
558 | } | |
7d2681a6 PM |
559 | } |
560 | ||
561 | static const struct Qdisc_class_ops sfq_class_ops = { | |
562 | .get = sfq_get, | |
563 | .change = sfq_change_class, | |
564 | .tcf_chain = sfq_find_tcf, | |
94de78d1 PM |
565 | .dump = sfq_dump_class, |
566 | .dump_stats = sfq_dump_class_stats, | |
7d2681a6 PM |
567 | .walk = sfq_walk, |
568 | }; | |
569 | ||
20fea08b | 570 | static struct Qdisc_ops sfq_qdisc_ops __read_mostly = { |
7d2681a6 | 571 | .cl_ops = &sfq_class_ops, |
1da177e4 LT |
572 | .id = "sfq", |
573 | .priv_size = sizeof(struct sfq_sched_data), | |
574 | .enqueue = sfq_enqueue, | |
575 | .dequeue = sfq_dequeue, | |
48a8f519 | 576 | .peek = sfq_peek, |
1da177e4 LT |
577 | .drop = sfq_drop, |
578 | .init = sfq_init, | |
579 | .reset = sfq_reset, | |
580 | .destroy = sfq_destroy, | |
581 | .change = NULL, | |
582 | .dump = sfq_dump, | |
583 | .owner = THIS_MODULE, | |
584 | }; | |
585 | ||
586 | static int __init sfq_module_init(void) | |
587 | { | |
588 | return register_qdisc(&sfq_qdisc_ops); | |
589 | } | |
10297b99 | 590 | static void __exit sfq_module_exit(void) |
1da177e4 LT |
591 | { |
592 | unregister_qdisc(&sfq_qdisc_ops); | |
593 | } | |
594 | module_init(sfq_module_init) | |
595 | module_exit(sfq_module_exit) | |
596 | MODULE_LICENSE("GPL"); |