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/netlink.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); 192 193 tcf_destroy_chain(q->filter_list); 194 for (prio=0; prio<q->bands; prio++) 195 qdisc_destroy(q->queues[prio]); 196 } 197 198 static int prio_tune(struct Qdisc *sch, struct rtattr *opt) 199 { 200 struct prio_sched_data *q = qdisc_priv(sch); 201 struct tc_prio_qopt *qopt = RTA_DATA(opt); 202 int i; 203 204 if (opt->rta_len < RTA_LENGTH(sizeof(*qopt))) 205 return -EINVAL; 206 if (qopt->bands > TCQ_PRIO_BANDS || qopt->bands < 2) 207 return -EINVAL; 208 209 for (i=0; i<=TC_PRIO_MAX; i++) { 210 if (qopt->priomap[i] >= qopt->bands) 211 return -EINVAL; 212 } 213 214 sch_tree_lock(sch); 215 q->bands = qopt->bands; 216 memcpy(q->prio2band, qopt->priomap, TC_PRIO_MAX+1); 217 218 for (i=q->bands; i<TCQ_PRIO_BANDS; i++) { 219 struct Qdisc *child = xchg(&q->queues[i], &noop_qdisc); 220 if (child != &noop_qdisc) { 221 qdisc_tree_decrease_qlen(child, child->q.qlen); 222 qdisc_destroy(child); 223 } 224 } 225 sch_tree_unlock(sch); 226 227 for (i=0; i<q->bands; i++) { 228 if (q->queues[i] == &noop_qdisc) { 229 struct Qdisc *child; 230 child = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops, 231 TC_H_MAKE(sch->handle, i + 1)); 232 if (child) { 233 sch_tree_lock(sch); 234 child = xchg(&q->queues[i], child); 235 236 if (child != &noop_qdisc) { 237 qdisc_tree_decrease_qlen(child, 238 child->q.qlen); 239 qdisc_destroy(child); 240 } 241 sch_tree_unlock(sch); 242 } 243 } 244 } 245 return 0; 246 } 247 248 static int prio_init(struct Qdisc *sch, struct rtattr *opt) 249 { 250 struct prio_sched_data *q = qdisc_priv(sch); 251 int i; 252 253 for (i=0; i<TCQ_PRIO_BANDS; i++) 254 q->queues[i] = &noop_qdisc; 255 256 if (opt == NULL) { 257 return -EINVAL; 258 } else { 259 int err; 260 261 if ((err= prio_tune(sch, opt)) != 0) 262 return err; 263 } 264 return 0; 265 } 266 267 static int prio_dump(struct Qdisc *sch, struct sk_buff *skb) 268 { 269 struct prio_sched_data *q = qdisc_priv(sch); 270 unsigned char *b = skb_tail_pointer(skb); 271 struct tc_prio_qopt opt; 272 273 opt.bands = q->bands; 274 memcpy(&opt.priomap, q->prio2band, TC_PRIO_MAX+1); 275 RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt); 276 return skb->len; 277 278 rtattr_failure: 279 nlmsg_trim(skb, b); 280 return -1; 281 } 282 283 static int prio_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, 284 struct Qdisc **old) 285 { 286 struct prio_sched_data *q = qdisc_priv(sch); 287 unsigned long band = arg - 1; 288 289 if (band >= q->bands) 290 return -EINVAL; 291 292 if (new == NULL) 293 new = &noop_qdisc; 294 295 sch_tree_lock(sch); 296 *old = q->queues[band]; 297 q->queues[band] = new; 298 qdisc_tree_decrease_qlen(*old, (*old)->q.qlen); 299 qdisc_reset(*old); 300 sch_tree_unlock(sch); 301 302 return 0; 303 } 304 305 static struct Qdisc * 306 prio_leaf(struct Qdisc *sch, unsigned long arg) 307 { 308 struct prio_sched_data *q = qdisc_priv(sch); 309 unsigned long band = arg - 1; 310 311 if (band >= q->bands) 312 return NULL; 313 314 return q->queues[band]; 315 } 316 317 static unsigned long prio_get(struct Qdisc *sch, u32 classid) 318 { 319 struct prio_sched_data *q = qdisc_priv(sch); 320 unsigned long band = TC_H_MIN(classid); 321 322 if (band - 1 >= q->bands) 323 return 0; 324 return band; 325 } 326 327 static unsigned long prio_bind(struct Qdisc *sch, unsigned long parent, u32 classid) 328 { 329 return prio_get(sch, classid); 330 } 331 332 333 static void prio_put(struct Qdisc *q, unsigned long cl) 334 { 335 return; 336 } 337 338 static int prio_change(struct Qdisc *sch, u32 handle, u32 parent, struct rtattr **tca, unsigned long *arg) 339 { 340 unsigned long cl = *arg; 341 struct prio_sched_data *q = qdisc_priv(sch); 342 343 if (cl - 1 > q->bands) 344 return -ENOENT; 345 return 0; 346 } 347 348 static int prio_delete(struct Qdisc *sch, unsigned long cl) 349 { 350 struct prio_sched_data *q = qdisc_priv(sch); 351 if (cl - 1 > q->bands) 352 return -ENOENT; 353 return 0; 354 } 355 356 357 static int prio_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb, 358 struct tcmsg *tcm) 359 { 360 struct prio_sched_data *q = qdisc_priv(sch); 361 362 if (cl - 1 > q->bands) 363 return -ENOENT; 364 tcm->tcm_handle |= TC_H_MIN(cl); 365 if (q->queues[cl-1]) 366 tcm->tcm_info = q->queues[cl-1]->handle; 367 return 0; 368 } 369 370 static int prio_dump_class_stats(struct Qdisc *sch, unsigned long cl, 371 struct gnet_dump *d) 372 { 373 struct prio_sched_data *q = qdisc_priv(sch); 374 struct Qdisc *cl_q; 375 376 cl_q = q->queues[cl - 1]; 377 if (gnet_stats_copy_basic(d, &cl_q->bstats) < 0 || 378 gnet_stats_copy_queue(d, &cl_q->qstats) < 0) 379 return -1; 380 381 return 0; 382 } 383 384 static void prio_walk(struct Qdisc *sch, struct qdisc_walker *arg) 385 { 386 struct prio_sched_data *q = qdisc_priv(sch); 387 int prio; 388 389 if (arg->stop) 390 return; 391 392 for (prio = 0; prio < q->bands; prio++) { 393 if (arg->count < arg->skip) { 394 arg->count++; 395 continue; 396 } 397 if (arg->fn(sch, prio+1, arg) < 0) { 398 arg->stop = 1; 399 break; 400 } 401 arg->count++; 402 } 403 } 404 405 static struct tcf_proto ** prio_find_tcf(struct Qdisc *sch, unsigned long cl) 406 { 407 struct prio_sched_data *q = qdisc_priv(sch); 408 409 if (cl) 410 return NULL; 411 return &q->filter_list; 412 } 413 414 static struct Qdisc_class_ops prio_class_ops = { 415 .graft = prio_graft, 416 .leaf = prio_leaf, 417 .get = prio_get, 418 .put = prio_put, 419 .change = prio_change, 420 .delete = prio_delete, 421 .walk = prio_walk, 422 .tcf_chain = prio_find_tcf, 423 .bind_tcf = prio_bind, 424 .unbind_tcf = prio_put, 425 .dump = prio_dump_class, 426 .dump_stats = prio_dump_class_stats, 427 }; 428 429 static struct Qdisc_ops prio_qdisc_ops = { 430 .next = NULL, 431 .cl_ops = &prio_class_ops, 432 .id = "prio", 433 .priv_size = sizeof(struct prio_sched_data), 434 .enqueue = prio_enqueue, 435 .dequeue = prio_dequeue, 436 .requeue = prio_requeue, 437 .drop = prio_drop, 438 .init = prio_init, 439 .reset = prio_reset, 440 .destroy = prio_destroy, 441 .change = prio_tune, 442 .dump = prio_dump, 443 .owner = THIS_MODULE, 444 }; 445 446 static int __init prio_module_init(void) 447 { 448 return register_qdisc(&prio_qdisc_ops); 449 } 450 451 static void __exit prio_module_exit(void) 452 { 453 unregister_qdisc(&prio_qdisc_ops); 454 } 455 456 module_init(prio_module_init) 457 module_exit(prio_module_exit) 458 459 MODULE_LICENSE("GPL"); 460