1 /* 2 * net/sched/sch_prio.c Simple 3-band priority "scheduler". 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 * Fixes: 19990609: J Hadi Salim <hadi@nortelnetworks.com>: 11 * Init -- EINVAL when opt undefined 12 */ 13 14 #include <linux/module.h> 15 #include <asm/uaccess.h> 16 #include <asm/system.h> 17 #include <linux/bitops.h> 18 #include <linux/types.h> 19 #include <linux/kernel.h> 20 #include <linux/string.h> 21 #include <linux/mm.h> 22 #include <linux/socket.h> 23 #include <linux/sockios.h> 24 #include <linux/in.h> 25 #include <linux/errno.h> 26 #include <linux/interrupt.h> 27 #include <linux/if_ether.h> 28 #include <linux/inet.h> 29 #include <linux/netdevice.h> 30 #include <linux/etherdevice.h> 31 #include <linux/notifier.h> 32 #include <net/ip.h> 33 #include <net/route.h> 34 #include <linux/skbuff.h> 35 #include <net/sock.h> 36 #include <net/pkt_sched.h> 37 38 39 struct prio_sched_data 40 { 41 int bands; 42 struct tcf_proto *filter_list; 43 u8 prio2band[TC_PRIO_MAX+1]; 44 struct Qdisc *queues[TCQ_PRIO_BANDS]; 45 }; 46 47 48 static struct Qdisc * 49 prio_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr) 50 { 51 struct prio_sched_data *q = qdisc_priv(sch); 52 u32 band = skb->priority; 53 struct tcf_result res; 54 55 *qerr = NET_XMIT_BYPASS; 56 if (TC_H_MAJ(skb->priority) != sch->handle) { 57 #ifdef CONFIG_NET_CLS_ACT 58 switch (tc_classify(skb, q->filter_list, &res)) { 59 case TC_ACT_STOLEN: 60 case TC_ACT_QUEUED: 61 *qerr = NET_XMIT_SUCCESS; 62 case TC_ACT_SHOT: 63 return NULL; 64 }; 65 66 if (!q->filter_list ) { 67 #else 68 if (!q->filter_list || tc_classify(skb, q->filter_list, &res)) { 69 #endif 70 if (TC_H_MAJ(band)) 71 band = 0; 72 return q->queues[q->prio2band[band&TC_PRIO_MAX]]; 73 } 74 band = res.classid; 75 } 76 band = TC_H_MIN(band) - 1; 77 if (band > q->bands) 78 return q->queues[q->prio2band[0]]; 79 80 return q->queues[band]; 81 } 82 83 static int 84 prio_enqueue(struct sk_buff *skb, struct Qdisc *sch) 85 { 86 struct Qdisc *qdisc; 87 int ret; 88 89 qdisc = prio_classify(skb, sch, &ret); 90 #ifdef CONFIG_NET_CLS_ACT 91 if (qdisc == NULL) { 92 93 if (ret == NET_XMIT_BYPASS) 94 sch->qstats.drops++; 95 kfree_skb(skb); 96 return ret; 97 } 98 #endif 99 100 if ((ret = qdisc->enqueue(skb, qdisc)) == NET_XMIT_SUCCESS) { 101 sch->bstats.bytes += skb->len; 102 sch->bstats.packets++; 103 sch->q.qlen++; 104 return NET_XMIT_SUCCESS; 105 } 106 sch->qstats.drops++; 107 return ret; 108 } 109 110 111 static int 112 prio_requeue(struct sk_buff *skb, struct Qdisc* sch) 113 { 114 struct Qdisc *qdisc; 115 int ret; 116 117 qdisc = prio_classify(skb, sch, &ret); 118 #ifdef CONFIG_NET_CLS_ACT 119 if (qdisc == NULL) { 120 if (ret == NET_XMIT_BYPASS) 121 sch->qstats.drops++; 122 kfree_skb(skb); 123 return ret; 124 } 125 #endif 126 127 if ((ret = qdisc->ops->requeue(skb, qdisc)) == NET_XMIT_SUCCESS) { 128 sch->q.qlen++; 129 sch->qstats.requeues++; 130 return 0; 131 } 132 sch->qstats.drops++; 133 return NET_XMIT_DROP; 134 } 135 136 137 static struct sk_buff * 138 prio_dequeue(struct Qdisc* sch) 139 { 140 struct sk_buff *skb; 141 struct prio_sched_data *q = qdisc_priv(sch); 142 int prio; 143 struct Qdisc *qdisc; 144 145 for (prio = 0; prio < q->bands; prio++) { 146 qdisc = q->queues[prio]; 147 skb = qdisc->dequeue(qdisc); 148 if (skb) { 149 sch->q.qlen--; 150 return skb; 151 } 152 } 153 return NULL; 154 155 } 156 157 static unsigned int prio_drop(struct Qdisc* sch) 158 { 159 struct prio_sched_data *q = qdisc_priv(sch); 160 int prio; 161 unsigned int len; 162 struct Qdisc *qdisc; 163 164 for (prio = q->bands-1; prio >= 0; prio--) { 165 qdisc = q->queues[prio]; 166 if (qdisc->ops->drop && (len = qdisc->ops->drop(qdisc)) != 0) { 167 sch->q.qlen--; 168 return len; 169 } 170 } 171 return 0; 172 } 173 174 175 static void 176 prio_reset(struct Qdisc* sch) 177 { 178 int prio; 179 struct prio_sched_data *q = qdisc_priv(sch); 180 181 for (prio=0; prio<q->bands; prio++) 182 qdisc_reset(q->queues[prio]); 183 sch->q.qlen = 0; 184 } 185 186 static void 187 prio_destroy(struct Qdisc* sch) 188 { 189 int prio; 190 struct prio_sched_data *q = qdisc_priv(sch); 191 struct tcf_proto *tp; 192 193 while ((tp = q->filter_list) != NULL) { 194 q->filter_list = tp->next; 195 tcf_destroy(tp); 196 } 197 198 for (prio=0; prio<q->bands; prio++) 199 qdisc_destroy(q->queues[prio]); 200 } 201 202 static int prio_tune(struct Qdisc *sch, struct rtattr *opt) 203 { 204 struct prio_sched_data *q = qdisc_priv(sch); 205 struct tc_prio_qopt *qopt = RTA_DATA(opt); 206 int i; 207 208 if (opt->rta_len < RTA_LENGTH(sizeof(*qopt))) 209 return -EINVAL; 210 if (qopt->bands > TCQ_PRIO_BANDS || qopt->bands < 2) 211 return -EINVAL; 212 213 for (i=0; i<=TC_PRIO_MAX; i++) { 214 if (qopt->priomap[i] >= qopt->bands) 215 return -EINVAL; 216 } 217 218 sch_tree_lock(sch); 219 q->bands = qopt->bands; 220 memcpy(q->prio2band, qopt->priomap, TC_PRIO_MAX+1); 221 222 for (i=q->bands; i<TCQ_PRIO_BANDS; i++) { 223 struct Qdisc *child = xchg(&q->queues[i], &noop_qdisc); 224 if (child != &noop_qdisc) { 225 qdisc_tree_decrease_qlen(child, child->q.qlen); 226 qdisc_destroy(child); 227 } 228 } 229 sch_tree_unlock(sch); 230 231 for (i=0; i<q->bands; i++) { 232 if (q->queues[i] == &noop_qdisc) { 233 struct Qdisc *child; 234 child = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops, 235 TC_H_MAKE(sch->handle, i + 1)); 236 if (child) { 237 sch_tree_lock(sch); 238 child = xchg(&q->queues[i], child); 239 240 if (child != &noop_qdisc) { 241 qdisc_tree_decrease_qlen(child, 242 child->q.qlen); 243 qdisc_destroy(child); 244 } 245 sch_tree_unlock(sch); 246 } 247 } 248 } 249 return 0; 250 } 251 252 static int prio_init(struct Qdisc *sch, struct rtattr *opt) 253 { 254 struct prio_sched_data *q = qdisc_priv(sch); 255 int i; 256 257 for (i=0; i<TCQ_PRIO_BANDS; i++) 258 q->queues[i] = &noop_qdisc; 259 260 if (opt == NULL) { 261 return -EINVAL; 262 } else { 263 int err; 264 265 if ((err= prio_tune(sch, opt)) != 0) 266 return err; 267 } 268 return 0; 269 } 270 271 static int prio_dump(struct Qdisc *sch, struct sk_buff *skb) 272 { 273 struct prio_sched_data *q = qdisc_priv(sch); 274 unsigned char *b = skb->tail; 275 struct tc_prio_qopt opt; 276 277 opt.bands = q->bands; 278 memcpy(&opt.priomap, q->prio2band, TC_PRIO_MAX+1); 279 RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt); 280 return skb->len; 281 282 rtattr_failure: 283 skb_trim(skb, b - skb->data); 284 return -1; 285 } 286 287 static int prio_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, 288 struct Qdisc **old) 289 { 290 struct prio_sched_data *q = qdisc_priv(sch); 291 unsigned long band = arg - 1; 292 293 if (band >= q->bands) 294 return -EINVAL; 295 296 if (new == NULL) 297 new = &noop_qdisc; 298 299 sch_tree_lock(sch); 300 *old = q->queues[band]; 301 q->queues[band] = new; 302 qdisc_tree_decrease_qlen(*old, (*old)->q.qlen); 303 qdisc_reset(*old); 304 sch_tree_unlock(sch); 305 306 return 0; 307 } 308 309 static struct Qdisc * 310 prio_leaf(struct Qdisc *sch, unsigned long arg) 311 { 312 struct prio_sched_data *q = qdisc_priv(sch); 313 unsigned long band = arg - 1; 314 315 if (band >= q->bands) 316 return NULL; 317 318 return q->queues[band]; 319 } 320 321 static unsigned long prio_get(struct Qdisc *sch, u32 classid) 322 { 323 struct prio_sched_data *q = qdisc_priv(sch); 324 unsigned long band = TC_H_MIN(classid); 325 326 if (band - 1 >= q->bands) 327 return 0; 328 return band; 329 } 330 331 static unsigned long prio_bind(struct Qdisc *sch, unsigned long parent, u32 classid) 332 { 333 return prio_get(sch, classid); 334 } 335 336 337 static void prio_put(struct Qdisc *q, unsigned long cl) 338 { 339 return; 340 } 341 342 static int prio_change(struct Qdisc *sch, u32 handle, u32 parent, struct rtattr **tca, unsigned long *arg) 343 { 344 unsigned long cl = *arg; 345 struct prio_sched_data *q = qdisc_priv(sch); 346 347 if (cl - 1 > q->bands) 348 return -ENOENT; 349 return 0; 350 } 351 352 static int prio_delete(struct Qdisc *sch, unsigned long cl) 353 { 354 struct prio_sched_data *q = qdisc_priv(sch); 355 if (cl - 1 > q->bands) 356 return -ENOENT; 357 return 0; 358 } 359 360 361 static int prio_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb, 362 struct tcmsg *tcm) 363 { 364 struct prio_sched_data *q = qdisc_priv(sch); 365 366 if (cl - 1 > q->bands) 367 return -ENOENT; 368 tcm->tcm_handle |= TC_H_MIN(cl); 369 if (q->queues[cl-1]) 370 tcm->tcm_info = q->queues[cl-1]->handle; 371 return 0; 372 } 373 374 static int prio_dump_class_stats(struct Qdisc *sch, unsigned long cl, 375 struct gnet_dump *d) 376 { 377 struct prio_sched_data *q = qdisc_priv(sch); 378 struct Qdisc *cl_q; 379 380 cl_q = q->queues[cl - 1]; 381 if (gnet_stats_copy_basic(d, &cl_q->bstats) < 0 || 382 gnet_stats_copy_queue(d, &cl_q->qstats) < 0) 383 return -1; 384 385 return 0; 386 } 387 388 static void prio_walk(struct Qdisc *sch, struct qdisc_walker *arg) 389 { 390 struct prio_sched_data *q = qdisc_priv(sch); 391 int prio; 392 393 if (arg->stop) 394 return; 395 396 for (prio = 0; prio < q->bands; prio++) { 397 if (arg->count < arg->skip) { 398 arg->count++; 399 continue; 400 } 401 if (arg->fn(sch, prio+1, arg) < 0) { 402 arg->stop = 1; 403 break; 404 } 405 arg->count++; 406 } 407 } 408 409 static struct tcf_proto ** prio_find_tcf(struct Qdisc *sch, unsigned long cl) 410 { 411 struct prio_sched_data *q = qdisc_priv(sch); 412 413 if (cl) 414 return NULL; 415 return &q->filter_list; 416 } 417 418 static struct Qdisc_class_ops prio_class_ops = { 419 .graft = prio_graft, 420 .leaf = prio_leaf, 421 .get = prio_get, 422 .put = prio_put, 423 .change = prio_change, 424 .delete = prio_delete, 425 .walk = prio_walk, 426 .tcf_chain = prio_find_tcf, 427 .bind_tcf = prio_bind, 428 .unbind_tcf = prio_put, 429 .dump = prio_dump_class, 430 .dump_stats = prio_dump_class_stats, 431 }; 432 433 static struct Qdisc_ops prio_qdisc_ops = { 434 .next = NULL, 435 .cl_ops = &prio_class_ops, 436 .id = "prio", 437 .priv_size = sizeof(struct prio_sched_data), 438 .enqueue = prio_enqueue, 439 .dequeue = prio_dequeue, 440 .requeue = prio_requeue, 441 .drop = prio_drop, 442 .init = prio_init, 443 .reset = prio_reset, 444 .destroy = prio_destroy, 445 .change = prio_tune, 446 .dump = prio_dump, 447 .owner = THIS_MODULE, 448 }; 449 450 static int __init prio_module_init(void) 451 { 452 return register_qdisc(&prio_qdisc_ops); 453 } 454 455 static void __exit prio_module_exit(void) 456 { 457 unregister_qdisc(&prio_qdisc_ops); 458 } 459 460 module_init(prio_module_init) 461 module_exit(prio_module_exit) 462 463 MODULE_LICENSE("GPL"); 464