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> |
5a0e3ad6 | 23 | #include <linux/slab.h> |
0ba48053 PM |
24 | #include <net/ip.h> |
25 | #include <net/netlink.h> | |
1da177e4 LT |
26 | #include <net/pkt_sched.h> |
27 | ||
28 | ||
29 | /* Stochastic Fairness Queuing algorithm. | |
30 | ======================================= | |
31 | ||
32 | Source: | |
33 | Paul E. McKenney "Stochastic Fairness Queuing", | |
34 | IEEE INFOCOMM'90 Proceedings, San Francisco, 1990. | |
35 | ||
36 | Paul E. McKenney "Stochastic Fairness Queuing", | |
37 | "Interworking: Research and Experience", v.2, 1991, p.113-131. | |
38 | ||
39 | ||
40 | See also: | |
41 | M. Shreedhar and George Varghese "Efficient Fair | |
42 | Queuing using Deficit Round Robin", Proc. SIGCOMM 95. | |
43 | ||
44 | ||
10297b99 | 45 | This is not the thing that is usually called (W)FQ nowadays. |
1da177e4 LT |
46 | It does not use any timestamp mechanism, but instead |
47 | processes queues in round-robin order. | |
48 | ||
49 | ADVANTAGE: | |
50 | ||
51 | - It is very cheap. Both CPU and memory requirements are minimal. | |
52 | ||
53 | DRAWBACKS: | |
54 | ||
10297b99 | 55 | - "Stochastic" -> It is not 100% fair. |
1da177e4 LT |
56 | When hash collisions occur, several flows are considered as one. |
57 | ||
58 | - "Round-robin" -> It introduces larger delays than virtual clock | |
59 | based schemes, and should not be used for isolating interactive | |
60 | traffic from non-interactive. It means, that this scheduler | |
61 | should be used as leaf of CBQ or P3, which put interactive traffic | |
62 | to higher priority band. | |
63 | ||
64 | We still need true WFQ for top level CSZ, but using WFQ | |
65 | for the best effort traffic is absolutely pointless: | |
66 | SFQ is superior for this purpose. | |
67 | ||
68 | IMPLEMENTATION: | |
69 | This implementation limits maximal queue length to 128; | |
eda83e3b | 70 | maximal mtu to 2^15-1; max 128 flows, number of hash buckets to 1024. |
1da177e4 | 71 | The only goal of this restrictions was that all data |
eda83e3b | 72 | fit into one 4K page on 32bit arches. |
1da177e4 LT |
73 | |
74 | It is easy to increase these values, but not in flight. */ | |
75 | ||
eda83e3b ED |
76 | #define SFQ_DEPTH 128 /* max number of packets per flow */ |
77 | #define SFQ_SLOTS 128 /* max number of flows */ | |
78 | #define SFQ_EMPTY_SLOT 255 | |
1da177e4 LT |
79 | #define SFQ_HASH_DIVISOR 1024 |
80 | ||
eda83e3b | 81 | /* This type should contain at least SFQ_DEPTH + SFQ_SLOTS values */ |
1da177e4 LT |
82 | typedef unsigned char sfq_index; |
83 | ||
eda83e3b ED |
84 | /* |
85 | * We dont use pointers to save space. | |
86 | * Small indexes [0 ... SFQ_SLOTS - 1] are 'pointers' to slots[] array | |
87 | * while following values [SFQ_SLOTS ... SFQ_SLOTS + SFQ_DEPTH - 1] | |
88 | * are 'pointers' to dep[] array | |
89 | */ | |
1da177e4 LT |
90 | struct sfq_head |
91 | { | |
92 | sfq_index next; | |
93 | sfq_index prev; | |
94 | }; | |
95 | ||
eda83e3b ED |
96 | struct sfq_slot { |
97 | struct sk_buff *skblist_next; | |
98 | struct sk_buff *skblist_prev; | |
99 | sfq_index qlen; /* number of skbs in skblist */ | |
100 | sfq_index next; /* next slot in sfq chain */ | |
101 | struct sfq_head dep; /* anchor in dep[] chains */ | |
102 | unsigned short hash; /* hash value (index in ht[]) */ | |
103 | short allot; /* credit for this slot */ | |
104 | }; | |
105 | ||
1da177e4 LT |
106 | struct sfq_sched_data |
107 | { | |
108 | /* Parameters */ | |
109 | int perturb_period; | |
110 | unsigned quantum; /* Allotment per round: MUST BE >= MTU */ | |
111 | int limit; | |
112 | ||
113 | /* Variables */ | |
7d2681a6 | 114 | struct tcf_proto *filter_list; |
1da177e4 | 115 | struct timer_list perturb_timer; |
32740ddc | 116 | u32 perturbation; |
eda83e3b | 117 | sfq_index cur_depth; /* depth of longest slot */ |
1da177e4 | 118 | |
eda83e3b | 119 | struct sfq_slot *tail; /* current slot in round */ |
1da177e4 | 120 | sfq_index ht[SFQ_HASH_DIVISOR]; /* Hash table */ |
eda83e3b ED |
121 | struct sfq_slot slots[SFQ_SLOTS]; |
122 | struct sfq_head dep[SFQ_DEPTH]; /* Linked list of slots, indexed by depth */ | |
1da177e4 LT |
123 | }; |
124 | ||
eda83e3b ED |
125 | /* |
126 | * sfq_head are either in a sfq_slot or in dep[] array | |
127 | */ | |
128 | static inline struct sfq_head *sfq_dep_head(struct sfq_sched_data *q, sfq_index val) | |
129 | { | |
130 | if (val < SFQ_SLOTS) | |
131 | return &q->slots[val].dep; | |
132 | return &q->dep[val - SFQ_SLOTS]; | |
133 | } | |
134 | ||
1da177e4 LT |
135 | static __inline__ unsigned sfq_fold_hash(struct sfq_sched_data *q, u32 h, u32 h1) |
136 | { | |
32740ddc | 137 | return jhash_2words(h, h1, q->perturbation) & (SFQ_HASH_DIVISOR - 1); |
1da177e4 LT |
138 | } |
139 | ||
140 | static unsigned sfq_hash(struct sfq_sched_data *q, struct sk_buff *skb) | |
141 | { | |
142 | u32 h, h2; | |
143 | ||
144 | switch (skb->protocol) { | |
60678040 | 145 | case htons(ETH_P_IP): |
1da177e4 | 146 | { |
f2f00981 | 147 | const struct iphdr *iph; |
b9959c2e | 148 | int poff; |
f2f00981 CG |
149 | |
150 | if (!pskb_network_may_pull(skb, sizeof(*iph))) | |
151 | goto err; | |
152 | iph = ip_hdr(skb); | |
0eae88f3 ED |
153 | h = (__force u32)iph->daddr; |
154 | h2 = (__force u32)iph->saddr ^ iph->protocol; | |
b9959c2e CG |
155 | if (iph->frag_off & htons(IP_MF|IP_OFFSET)) |
156 | break; | |
157 | poff = proto_ports_offset(iph->protocol); | |
158 | if (poff >= 0 && | |
159 | pskb_network_may_pull(skb, iph->ihl * 4 + 4 + poff)) { | |
160 | iph = ip_hdr(skb); | |
161 | h2 ^= *(u32*)((void *)iph + iph->ihl * 4 + poff); | |
162 | } | |
1da177e4 LT |
163 | break; |
164 | } | |
60678040 | 165 | case htons(ETH_P_IPV6): |
1da177e4 | 166 | { |
f2f00981 | 167 | struct ipv6hdr *iph; |
b9959c2e | 168 | int poff; |
f2f00981 CG |
169 | |
170 | if (!pskb_network_may_pull(skb, sizeof(*iph))) | |
171 | goto err; | |
172 | iph = ipv6_hdr(skb); | |
0eae88f3 ED |
173 | h = (__force u32)iph->daddr.s6_addr32[3]; |
174 | h2 = (__force u32)iph->saddr.s6_addr32[3] ^ iph->nexthdr; | |
b9959c2e CG |
175 | poff = proto_ports_offset(iph->nexthdr); |
176 | if (poff >= 0 && | |
177 | pskb_network_may_pull(skb, sizeof(*iph) + 4 + poff)) { | |
178 | iph = ipv6_hdr(skb); | |
179 | h2 ^= *(u32*)((void *)iph + sizeof(*iph) + poff); | |
180 | } | |
1da177e4 LT |
181 | break; |
182 | } | |
183 | default: | |
f2f00981 | 184 | err: |
0eae88f3 | 185 | h = (unsigned long)skb_dst(skb) ^ (__force u32)skb->protocol; |
6f9e98f7 | 186 | h2 = (unsigned long)skb->sk; |
1da177e4 | 187 | } |
6f9e98f7 | 188 | |
1da177e4 LT |
189 | return sfq_fold_hash(q, h, h2); |
190 | } | |
191 | ||
7d2681a6 PM |
192 | static unsigned int sfq_classify(struct sk_buff *skb, struct Qdisc *sch, |
193 | int *qerr) | |
194 | { | |
195 | struct sfq_sched_data *q = qdisc_priv(sch); | |
196 | struct tcf_result res; | |
197 | int result; | |
198 | ||
199 | if (TC_H_MAJ(skb->priority) == sch->handle && | |
200 | TC_H_MIN(skb->priority) > 0 && | |
201 | TC_H_MIN(skb->priority) <= SFQ_HASH_DIVISOR) | |
202 | return TC_H_MIN(skb->priority); | |
203 | ||
204 | if (!q->filter_list) | |
205 | return sfq_hash(q, skb) + 1; | |
206 | ||
c27f339a | 207 | *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; |
7d2681a6 PM |
208 | result = tc_classify(skb, q->filter_list, &res); |
209 | if (result >= 0) { | |
210 | #ifdef CONFIG_NET_CLS_ACT | |
211 | switch (result) { | |
212 | case TC_ACT_STOLEN: | |
213 | case TC_ACT_QUEUED: | |
378a2f09 | 214 | *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN; |
7d2681a6 PM |
215 | case TC_ACT_SHOT: |
216 | return 0; | |
217 | } | |
218 | #endif | |
219 | if (TC_H_MIN(res.classid) <= SFQ_HASH_DIVISOR) | |
220 | return TC_H_MIN(res.classid); | |
221 | } | |
222 | return 0; | |
223 | } | |
224 | ||
eda83e3b ED |
225 | /* |
226 | * x : slot number [0 .. SFQ_SLOTS - 1] | |
227 | */ | |
1da177e4 LT |
228 | static inline void sfq_link(struct sfq_sched_data *q, sfq_index x) |
229 | { | |
230 | sfq_index p, n; | |
eda83e3b ED |
231 | int qlen = q->slots[x].qlen; |
232 | ||
233 | p = qlen + SFQ_SLOTS; | |
234 | n = q->dep[qlen].next; | |
1da177e4 | 235 | |
eda83e3b ED |
236 | q->slots[x].dep.next = n; |
237 | q->slots[x].dep.prev = p; | |
238 | ||
239 | q->dep[qlen].next = x; /* sfq_dep_head(q, p)->next = x */ | |
240 | sfq_dep_head(q, n)->prev = x; | |
1da177e4 LT |
241 | } |
242 | ||
eda83e3b ED |
243 | #define sfq_unlink(q, x, n, p) \ |
244 | n = q->slots[x].dep.next; \ | |
245 | p = q->slots[x].dep.prev; \ | |
246 | sfq_dep_head(q, p)->next = n; \ | |
247 | sfq_dep_head(q, n)->prev = p | |
248 | ||
249 | ||
1da177e4 LT |
250 | static inline void sfq_dec(struct sfq_sched_data *q, sfq_index x) |
251 | { | |
252 | sfq_index p, n; | |
eda83e3b | 253 | int d; |
1da177e4 | 254 | |
eda83e3b | 255 | sfq_unlink(q, x, n, p); |
1da177e4 | 256 | |
eda83e3b ED |
257 | d = q->slots[x].qlen--; |
258 | if (n == p && q->cur_depth == d) | |
259 | q->cur_depth--; | |
1da177e4 LT |
260 | sfq_link(q, x); |
261 | } | |
262 | ||
263 | static inline void sfq_inc(struct sfq_sched_data *q, sfq_index x) | |
264 | { | |
265 | sfq_index p, n; | |
266 | int d; | |
267 | ||
eda83e3b | 268 | sfq_unlink(q, x, n, p); |
1da177e4 | 269 | |
eda83e3b ED |
270 | d = ++q->slots[x].qlen; |
271 | if (q->cur_depth < d) | |
272 | q->cur_depth = d; | |
1da177e4 LT |
273 | sfq_link(q, x); |
274 | } | |
275 | ||
eda83e3b ED |
276 | /* helper functions : might be changed when/if skb use a standard list_head */ |
277 | ||
278 | /* remove one skb from tail of slot queue */ | |
279 | static inline struct sk_buff *slot_dequeue_tail(struct sfq_slot *slot) | |
280 | { | |
281 | struct sk_buff *skb = slot->skblist_prev; | |
282 | ||
283 | slot->skblist_prev = skb->prev; | |
284 | skb->next = skb->prev = NULL; | |
285 | return skb; | |
286 | } | |
287 | ||
288 | /* remove one skb from head of slot queue */ | |
289 | static inline struct sk_buff *slot_dequeue_head(struct sfq_slot *slot) | |
290 | { | |
291 | struct sk_buff *skb = slot->skblist_next; | |
292 | ||
293 | slot->skblist_next = skb->next; | |
294 | skb->next = skb->prev = NULL; | |
295 | return skb; | |
296 | } | |
297 | ||
298 | static inline void slot_queue_init(struct sfq_slot *slot) | |
299 | { | |
300 | slot->skblist_prev = slot->skblist_next = (struct sk_buff *)slot; | |
301 | } | |
302 | ||
303 | /* add skb to slot queue (tail add) */ | |
304 | static inline void slot_queue_add(struct sfq_slot *slot, struct sk_buff *skb) | |
305 | { | |
306 | skb->prev = slot->skblist_prev; | |
307 | skb->next = (struct sk_buff *)slot; | |
308 | slot->skblist_prev->next = skb; | |
309 | slot->skblist_prev = skb; | |
310 | } | |
311 | ||
312 | #define slot_queue_walk(slot, skb) \ | |
313 | for (skb = slot->skblist_next; \ | |
314 | skb != (struct sk_buff *)slot; \ | |
315 | skb = skb->next) | |
316 | ||
1da177e4 LT |
317 | static unsigned int sfq_drop(struct Qdisc *sch) |
318 | { | |
319 | struct sfq_sched_data *q = qdisc_priv(sch); | |
eda83e3b | 320 | sfq_index x, d = q->cur_depth; |
1da177e4 LT |
321 | struct sk_buff *skb; |
322 | unsigned int len; | |
eda83e3b | 323 | struct sfq_slot *slot; |
1da177e4 | 324 | |
eda83e3b | 325 | /* Queue is full! Find the longest slot and drop tail packet from it */ |
1da177e4 | 326 | if (d > 1) { |
eda83e3b ED |
327 | x = q->dep[d].next; |
328 | slot = &q->slots[x]; | |
329 | drop: | |
330 | skb = slot_dequeue_tail(slot); | |
0abf77e5 | 331 | len = qdisc_pkt_len(skb); |
1da177e4 | 332 | sfq_dec(q, x); |
eda83e3b | 333 | kfree_skb(skb); |
1da177e4 LT |
334 | sch->q.qlen--; |
335 | sch->qstats.drops++; | |
f5539eb8 | 336 | sch->qstats.backlog -= len; |
1da177e4 LT |
337 | return len; |
338 | } | |
339 | ||
340 | if (d == 1) { | |
341 | /* It is difficult to believe, but ALL THE SLOTS HAVE LENGTH 1. */ | |
eda83e3b ED |
342 | x = q->tail->next; |
343 | slot = &q->slots[x]; | |
344 | q->tail->next = slot->next; | |
345 | q->ht[slot->hash] = SFQ_EMPTY_SLOT; | |
346 | goto drop; | |
1da177e4 LT |
347 | } |
348 | ||
349 | return 0; | |
350 | } | |
351 | ||
352 | static int | |
6f9e98f7 | 353 | sfq_enqueue(struct sk_buff *skb, struct Qdisc *sch) |
1da177e4 LT |
354 | { |
355 | struct sfq_sched_data *q = qdisc_priv(sch); | |
7d2681a6 | 356 | unsigned int hash; |
1da177e4 | 357 | sfq_index x; |
eda83e3b | 358 | struct sfq_slot *slot; |
7f3ff4f6 | 359 | int uninitialized_var(ret); |
7d2681a6 PM |
360 | |
361 | hash = sfq_classify(skb, sch, &ret); | |
362 | if (hash == 0) { | |
c27f339a | 363 | if (ret & __NET_XMIT_BYPASS) |
7d2681a6 PM |
364 | sch->qstats.drops++; |
365 | kfree_skb(skb); | |
366 | return ret; | |
367 | } | |
368 | hash--; | |
1da177e4 LT |
369 | |
370 | x = q->ht[hash]; | |
eda83e3b ED |
371 | slot = &q->slots[x]; |
372 | if (x == SFQ_EMPTY_SLOT) { | |
373 | x = q->dep[0].next; /* get a free slot */ | |
374 | q->ht[hash] = x; | |
375 | slot = &q->slots[x]; | |
376 | slot->hash = hash; | |
377 | slot_queue_init(slot); | |
1da177e4 | 378 | } |
6f9e98f7 | 379 | |
eda83e3b | 380 | /* If selected queue has length q->limit, do simple tail drop, |
32740ddc AK |
381 | * i.e. drop _this_ packet. |
382 | */ | |
eda83e3b | 383 | if (slot->qlen >= q->limit) |
32740ddc AK |
384 | return qdisc_drop(skb, sch); |
385 | ||
0abf77e5 | 386 | sch->qstats.backlog += qdisc_pkt_len(skb); |
eda83e3b | 387 | slot_queue_add(slot, skb); |
1da177e4 | 388 | sfq_inc(q, x); |
eda83e3b ED |
389 | if (slot->qlen == 1) { /* The flow is new */ |
390 | if (q->tail == NULL) { /* It is the first flow */ | |
391 | slot->next = x; | |
1da177e4 | 392 | } else { |
eda83e3b ED |
393 | slot->next = q->tail->next; |
394 | q->tail->next = x; | |
1da177e4 | 395 | } |
eda83e3b ED |
396 | q->tail = slot; |
397 | slot->allot = q->quantum; | |
1da177e4 | 398 | } |
5588b40d | 399 | if (++sch->q.qlen <= q->limit) { |
0abf77e5 | 400 | sch->bstats.bytes += qdisc_pkt_len(skb); |
1da177e4 | 401 | sch->bstats.packets++; |
9871e50e | 402 | return NET_XMIT_SUCCESS; |
1da177e4 LT |
403 | } |
404 | ||
405 | sfq_drop(sch); | |
406 | return NET_XMIT_CN; | |
407 | } | |
408 | ||
48a8f519 PM |
409 | static struct sk_buff * |
410 | sfq_peek(struct Qdisc *sch) | |
411 | { | |
412 | struct sfq_sched_data *q = qdisc_priv(sch); | |
1da177e4 | 413 | |
48a8f519 | 414 | /* No active slots */ |
eda83e3b | 415 | if (q->tail == NULL) |
48a8f519 | 416 | return NULL; |
1da177e4 | 417 | |
eda83e3b | 418 | return q->slots[q->tail->next].skblist_next; |
48a8f519 | 419 | } |
1da177e4 LT |
420 | |
421 | static struct sk_buff * | |
6f9e98f7 | 422 | sfq_dequeue(struct Qdisc *sch) |
1da177e4 LT |
423 | { |
424 | struct sfq_sched_data *q = qdisc_priv(sch); | |
425 | struct sk_buff *skb; | |
aa3e2199 | 426 | sfq_index a, next_a; |
eda83e3b | 427 | struct sfq_slot *slot; |
1da177e4 LT |
428 | |
429 | /* No active slots */ | |
eda83e3b | 430 | if (q->tail == NULL) |
1da177e4 LT |
431 | return NULL; |
432 | ||
eda83e3b ED |
433 | a = q->tail->next; |
434 | slot = &q->slots[a]; | |
435 | skb = slot_dequeue_head(slot); | |
1da177e4 LT |
436 | sfq_dec(q, a); |
437 | sch->q.qlen--; | |
0abf77e5 | 438 | sch->qstats.backlog -= qdisc_pkt_len(skb); |
1da177e4 LT |
439 | |
440 | /* Is the slot empty? */ | |
eda83e3b ED |
441 | if (slot->qlen == 0) { |
442 | q->ht[slot->hash] = SFQ_EMPTY_SLOT; | |
443 | next_a = slot->next; | |
aa3e2199 | 444 | if (a == next_a) { |
eda83e3b | 445 | q->tail = NULL; /* no more active slots */ |
1da177e4 LT |
446 | return skb; |
447 | } | |
eda83e3b ED |
448 | q->tail->next = next_a; |
449 | } else if ((slot->allot -= qdisc_pkt_len(skb)) <= 0) { | |
450 | q->tail = slot; | |
451 | slot->allot += q->quantum; | |
1da177e4 LT |
452 | } |
453 | return skb; | |
454 | } | |
455 | ||
456 | static void | |
6f9e98f7 | 457 | sfq_reset(struct Qdisc *sch) |
1da177e4 LT |
458 | { |
459 | struct sk_buff *skb; | |
460 | ||
461 | while ((skb = sfq_dequeue(sch)) != NULL) | |
462 | kfree_skb(skb); | |
463 | } | |
464 | ||
465 | static void sfq_perturbation(unsigned long arg) | |
466 | { | |
6f9e98f7 | 467 | struct Qdisc *sch = (struct Qdisc *)arg; |
1da177e4 LT |
468 | struct sfq_sched_data *q = qdisc_priv(sch); |
469 | ||
d46f8dd8 | 470 | q->perturbation = net_random(); |
1da177e4 | 471 | |
32740ddc AK |
472 | if (q->perturb_period) |
473 | mod_timer(&q->perturb_timer, jiffies + q->perturb_period); | |
1da177e4 LT |
474 | } |
475 | ||
1e90474c | 476 | static int sfq_change(struct Qdisc *sch, struct nlattr *opt) |
1da177e4 LT |
477 | { |
478 | struct sfq_sched_data *q = qdisc_priv(sch); | |
1e90474c | 479 | struct tc_sfq_qopt *ctl = nla_data(opt); |
5e50da01 | 480 | unsigned int qlen; |
1da177e4 | 481 | |
1e90474c | 482 | if (opt->nla_len < nla_attr_size(sizeof(*ctl))) |
1da177e4 LT |
483 | return -EINVAL; |
484 | ||
485 | sch_tree_lock(sch); | |
5ce2d488 | 486 | q->quantum = ctl->quantum ? : psched_mtu(qdisc_dev(sch)); |
6f9e98f7 | 487 | q->perturb_period = ctl->perturb_period * HZ; |
1da177e4 | 488 | if (ctl->limit) |
32740ddc | 489 | q->limit = min_t(u32, ctl->limit, SFQ_DEPTH - 1); |
1da177e4 | 490 | |
5e50da01 | 491 | qlen = sch->q.qlen; |
5588b40d | 492 | while (sch->q.qlen > q->limit) |
1da177e4 | 493 | sfq_drop(sch); |
5e50da01 | 494 | qdisc_tree_decrease_qlen(sch, qlen - sch->q.qlen); |
1da177e4 LT |
495 | |
496 | del_timer(&q->perturb_timer); | |
497 | if (q->perturb_period) { | |
32740ddc | 498 | mod_timer(&q->perturb_timer, jiffies + q->perturb_period); |
d46f8dd8 | 499 | q->perturbation = net_random(); |
1da177e4 LT |
500 | } |
501 | sch_tree_unlock(sch); | |
502 | return 0; | |
503 | } | |
504 | ||
1e90474c | 505 | static int sfq_init(struct Qdisc *sch, struct nlattr *opt) |
1da177e4 LT |
506 | { |
507 | struct sfq_sched_data *q = qdisc_priv(sch); | |
508 | int i; | |
509 | ||
d3e99483 | 510 | q->perturb_timer.function = sfq_perturbation; |
c19a28e1 | 511 | q->perturb_timer.data = (unsigned long)sch; |
d3e99483 | 512 | init_timer_deferrable(&q->perturb_timer); |
1da177e4 | 513 | |
6f9e98f7 | 514 | for (i = 0; i < SFQ_HASH_DIVISOR; i++) |
eda83e3b | 515 | q->ht[i] = SFQ_EMPTY_SLOT; |
6f9e98f7 SH |
516 | |
517 | for (i = 0; i < SFQ_DEPTH; i++) { | |
eda83e3b ED |
518 | q->dep[i].next = i + SFQ_SLOTS; |
519 | q->dep[i].prev = i + SFQ_SLOTS; | |
1da177e4 | 520 | } |
6f9e98f7 | 521 | |
32740ddc | 522 | q->limit = SFQ_DEPTH - 1; |
eda83e3b ED |
523 | q->cur_depth = 0; |
524 | q->tail = NULL; | |
1da177e4 | 525 | if (opt == NULL) { |
5ce2d488 | 526 | q->quantum = psched_mtu(qdisc_dev(sch)); |
1da177e4 | 527 | q->perturb_period = 0; |
d46f8dd8 | 528 | q->perturbation = net_random(); |
1da177e4 LT |
529 | } else { |
530 | int err = sfq_change(sch, opt); | |
531 | if (err) | |
532 | return err; | |
533 | } | |
6f9e98f7 | 534 | |
eda83e3b | 535 | for (i = 0; i < SFQ_SLOTS; i++) |
1da177e4 LT |
536 | sfq_link(q, i); |
537 | return 0; | |
538 | } | |
539 | ||
540 | static void sfq_destroy(struct Qdisc *sch) | |
541 | { | |
542 | struct sfq_sched_data *q = qdisc_priv(sch); | |
7d2681a6 | 543 | |
ff31ab56 | 544 | tcf_destroy_chain(&q->filter_list); |
980c478d JP |
545 | q->perturb_period = 0; |
546 | del_timer_sync(&q->perturb_timer); | |
1da177e4 LT |
547 | } |
548 | ||
549 | static int sfq_dump(struct Qdisc *sch, struct sk_buff *skb) | |
550 | { | |
551 | struct sfq_sched_data *q = qdisc_priv(sch); | |
27a884dc | 552 | unsigned char *b = skb_tail_pointer(skb); |
1da177e4 LT |
553 | struct tc_sfq_qopt opt; |
554 | ||
555 | opt.quantum = q->quantum; | |
6f9e98f7 | 556 | opt.perturb_period = q->perturb_period / HZ; |
1da177e4 LT |
557 | |
558 | opt.limit = q->limit; | |
559 | opt.divisor = SFQ_HASH_DIVISOR; | |
cdec7e50 | 560 | opt.flows = q->limit; |
1da177e4 | 561 | |
1e90474c | 562 | NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt); |
1da177e4 LT |
563 | |
564 | return skb->len; | |
565 | ||
1e90474c | 566 | nla_put_failure: |
dc5fc579 | 567 | nlmsg_trim(skb, b); |
1da177e4 LT |
568 | return -1; |
569 | } | |
570 | ||
41065fba JP |
571 | static struct Qdisc *sfq_leaf(struct Qdisc *sch, unsigned long arg) |
572 | { | |
573 | return NULL; | |
574 | } | |
575 | ||
7d2681a6 PM |
576 | static unsigned long sfq_get(struct Qdisc *sch, u32 classid) |
577 | { | |
578 | return 0; | |
579 | } | |
580 | ||
eb4a5527 JP |
581 | static unsigned long sfq_bind(struct Qdisc *sch, unsigned long parent, |
582 | u32 classid) | |
583 | { | |
584 | return 0; | |
585 | } | |
586 | ||
da7115d9 JP |
587 | static void sfq_put(struct Qdisc *q, unsigned long cl) |
588 | { | |
589 | } | |
590 | ||
7d2681a6 PM |
591 | static struct tcf_proto **sfq_find_tcf(struct Qdisc *sch, unsigned long cl) |
592 | { | |
593 | struct sfq_sched_data *q = qdisc_priv(sch); | |
594 | ||
595 | if (cl) | |
596 | return NULL; | |
597 | return &q->filter_list; | |
598 | } | |
599 | ||
94de78d1 PM |
600 | static int sfq_dump_class(struct Qdisc *sch, unsigned long cl, |
601 | struct sk_buff *skb, struct tcmsg *tcm) | |
602 | { | |
603 | tcm->tcm_handle |= TC_H_MIN(cl); | |
604 | return 0; | |
605 | } | |
606 | ||
607 | static int sfq_dump_class_stats(struct Qdisc *sch, unsigned long cl, | |
608 | struct gnet_dump *d) | |
609 | { | |
610 | struct sfq_sched_data *q = qdisc_priv(sch); | |
eda83e3b ED |
611 | const struct sfq_slot *slot = &q->slots[q->ht[cl - 1]]; |
612 | struct gnet_stats_queue qs = { .qlen = slot->qlen }; | |
613 | struct tc_sfq_xstats xstats = { .allot = slot->allot }; | |
c4266263 ED |
614 | struct sk_buff *skb; |
615 | ||
eda83e3b | 616 | slot_queue_walk(slot, skb) |
c4266263 | 617 | qs.backlog += qdisc_pkt_len(skb); |
94de78d1 PM |
618 | |
619 | if (gnet_stats_copy_queue(d, &qs) < 0) | |
620 | return -1; | |
621 | return gnet_stats_copy_app(d, &xstats, sizeof(xstats)); | |
622 | } | |
623 | ||
7d2681a6 PM |
624 | static void sfq_walk(struct Qdisc *sch, struct qdisc_walker *arg) |
625 | { | |
94de78d1 PM |
626 | struct sfq_sched_data *q = qdisc_priv(sch); |
627 | unsigned int i; | |
628 | ||
629 | if (arg->stop) | |
630 | return; | |
631 | ||
632 | for (i = 0; i < SFQ_HASH_DIVISOR; i++) { | |
eda83e3b | 633 | if (q->ht[i] == SFQ_EMPTY_SLOT || |
94de78d1 PM |
634 | arg->count < arg->skip) { |
635 | arg->count++; | |
636 | continue; | |
637 | } | |
638 | if (arg->fn(sch, i + 1, arg) < 0) { | |
639 | arg->stop = 1; | |
640 | break; | |
641 | } | |
642 | arg->count++; | |
643 | } | |
7d2681a6 PM |
644 | } |
645 | ||
646 | static const struct Qdisc_class_ops sfq_class_ops = { | |
41065fba | 647 | .leaf = sfq_leaf, |
7d2681a6 | 648 | .get = sfq_get, |
da7115d9 | 649 | .put = sfq_put, |
7d2681a6 | 650 | .tcf_chain = sfq_find_tcf, |
eb4a5527 | 651 | .bind_tcf = sfq_bind, |
da7115d9 | 652 | .unbind_tcf = sfq_put, |
94de78d1 PM |
653 | .dump = sfq_dump_class, |
654 | .dump_stats = sfq_dump_class_stats, | |
7d2681a6 PM |
655 | .walk = sfq_walk, |
656 | }; | |
657 | ||
20fea08b | 658 | static struct Qdisc_ops sfq_qdisc_ops __read_mostly = { |
7d2681a6 | 659 | .cl_ops = &sfq_class_ops, |
1da177e4 LT |
660 | .id = "sfq", |
661 | .priv_size = sizeof(struct sfq_sched_data), | |
662 | .enqueue = sfq_enqueue, | |
663 | .dequeue = sfq_dequeue, | |
48a8f519 | 664 | .peek = sfq_peek, |
1da177e4 LT |
665 | .drop = sfq_drop, |
666 | .init = sfq_init, | |
667 | .reset = sfq_reset, | |
668 | .destroy = sfq_destroy, | |
669 | .change = NULL, | |
670 | .dump = sfq_dump, | |
671 | .owner = THIS_MODULE, | |
672 | }; | |
673 | ||
674 | static int __init sfq_module_init(void) | |
675 | { | |
676 | return register_qdisc(&sfq_qdisc_ops); | |
677 | } | |
10297b99 | 678 | static void __exit sfq_module_exit(void) |
1da177e4 LT |
679 | { |
680 | unregister_qdisc(&sfq_qdisc_ops); | |
681 | } | |
682 | module_init(sfq_module_init) | |
683 | module_exit(sfq_module_exit) | |
684 | MODULE_LICENSE("GPL"); |