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