1 /* $KAME: altq_rio.c,v 1.17 2003/07/10 12:07:49 kjc Exp $ */ 2 /* $DragonFly: src/sys/net/altq/altq_rio.c,v 1.3 2006/12/22 23:44:55 swildner Exp $ */ 3 4 /* 5 * Copyright (C) 1998-2003 6 * Sony Computer Science Laboratories Inc. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY SONY CSL AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL SONY CSL OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 /* 30 * Copyright (c) 1990-1994 Regents of the University of California. 31 * All rights reserved. 32 * 33 * Redistribution and use in source and binary forms, with or without 34 * modification, are permitted provided that the following conditions 35 * are met: 36 * 1. Redistributions of source code must retain the above copyright 37 * notice, this list of conditions and the following disclaimer. 38 * 2. Redistributions in binary form must reproduce the above copyright 39 * notice, this list of conditions and the following disclaimer in the 40 * documentation and/or other materials provided with the distribution. 41 * 3. All advertising materials mentioning features or use of this software 42 * must display the following acknowledgement: 43 * This product includes software developed by the Computer Systems 44 * Engineering Group at Lawrence Berkeley Laboratory. 45 * 4. Neither the name of the University nor of the Laboratory may be used 46 * to endorse or promote products derived from this software without 47 * specific prior written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 59 * SUCH DAMAGE. 60 */ 61 62 #include "opt_altq.h" 63 #include "opt_inet.h" 64 #include "opt_inet6.h" 65 66 #ifdef ALTQ_RIO /* rio is enabled by ALTQ_RIO option in opt_altq.h */ 67 68 #include <sys/param.h> 69 #include <sys/malloc.h> 70 #include <sys/mbuf.h> 71 #include <sys/socket.h> 72 #include <sys/systm.h> 73 #include <sys/errno.h> 74 75 #include <net/if.h> 76 #include <net/ifq_var.h> 77 78 #include <netinet/in.h> 79 #include <netinet/in_systm.h> 80 #include <netinet/ip.h> 81 #ifdef INET6 82 #include <netinet/ip6.h> 83 #endif 84 85 #include <net/pf/pfvar.h> 86 #include <net/altq/altq.h> 87 #include <net/altq/altq_red.h> 88 #include <net/altq/altq_rio.h> 89 90 /* 91 * RIO: RED with IN/OUT bit 92 * described in 93 * "Explicit Allocation of Best Effort Packet Delivery Service" 94 * David D. Clark and Wenjia Fang, MIT Lab for Computer Science 95 * http://diffserv.lcs.mit.edu/Papers/exp-alloc-ddc-wf.{ps,pdf} 96 * 97 * this implementation is extended to support more than 2 drop precedence 98 * values as described in RFC2597 (Assured Forwarding PHB Group). 99 * 100 */ 101 /* 102 * AF DS (differentiated service) codepoints. 103 * (classes can be mapped to CBQ or H-FSC classes.) 104 * 105 * 0 1 2 3 4 5 6 7 106 * +---+---+---+---+---+---+---+---+ 107 * | CLASS |DropPre| 0 | CU | 108 * +---+---+---+---+---+---+---+---+ 109 * 110 * class 1: 001 111 * class 2: 010 112 * class 3: 011 113 * class 4: 100 114 * 115 * low drop prec: 01 116 * medium drop prec: 10 117 * high drop prec: 11 118 */ 119 120 /* normal red parameters */ 121 #define W_WEIGHT 512 /* inverse of weight of EWMA (511/512) */ 122 /* q_weight = 0.00195 */ 123 124 /* red parameters for a slow link */ 125 #define W_WEIGHT_1 128 /* inverse of weight of EWMA (127/128) */ 126 /* q_weight = 0.0078125 */ 127 128 /* red parameters for a very slow link (e.g., dialup) */ 129 #define W_WEIGHT_2 64 /* inverse of weight of EWMA (63/64) */ 130 /* q_weight = 0.015625 */ 131 132 /* fixed-point uses 12-bit decimal places */ 133 #define FP_SHIFT 12 /* fixed-point shift */ 134 135 /* red parameters for drop probability */ 136 #define INV_P_MAX 10 /* inverse of max drop probability */ 137 #define TH_MIN 5 /* min threshold */ 138 #define TH_MAX 15 /* max threshold */ 139 140 #define RIO_LIMIT 60 /* default max queue lenght */ 141 #define RIO_STATS /* collect statistics */ 142 143 /* default rio parameter values */ 144 static struct redparams default_rio_params[RIO_NDROPPREC] = { 145 /* th_min, th_max, inv_pmax */ 146 { TH_MAX * 2 + TH_MIN, TH_MAX * 3, INV_P_MAX }, /* low drop precedence */ 147 { TH_MAX + TH_MIN, TH_MAX * 2, INV_P_MAX }, /* medium drop precedence */ 148 { TH_MIN, TH_MAX, INV_P_MAX } /* high drop precedence */ 149 }; 150 151 /* internal function prototypes */ 152 static int dscp2index(uint8_t); 153 /* YYY Do we really need this? */ 154 #define AF_DROPPRECMASK 0x18 155 #define DSCP_MASK 0xfc 156 157 rio_t * 158 rio_alloc(int weight, struct redparams *params, int flags, int pkttime) 159 { 160 rio_t *rp; 161 int w, i; 162 int npkts_per_sec; 163 164 rp = kmalloc(sizeof(*rp), M_ALTQ, M_WAITOK | M_ZERO); 165 166 rp->rio_flags = flags; 167 if (pkttime == 0) 168 /* default packet time: 1000 bytes / 10Mbps * 8 * 1000000 */ 169 rp->rio_pkttime = 800; 170 else 171 rp->rio_pkttime = pkttime; 172 173 if (weight != 0) 174 rp->rio_weight = weight; 175 else { 176 /* use default */ 177 rp->rio_weight = W_WEIGHT; 178 179 /* when the link is very slow, adjust red parameters */ 180 npkts_per_sec = 1000000 / rp->rio_pkttime; 181 if (npkts_per_sec < 50) { 182 /* up to about 400Kbps */ 183 rp->rio_weight = W_WEIGHT_2; 184 } else if (npkts_per_sec < 300) { 185 /* up to about 2.4Mbps */ 186 rp->rio_weight = W_WEIGHT_1; 187 } 188 } 189 190 /* calculate wshift. weight must be power of 2 */ 191 w = rp->rio_weight; 192 for (i = 0; w > 1; i++) 193 w = w >> 1; 194 rp->rio_wshift = i; 195 w = 1 << rp->rio_wshift; 196 if (w != rp->rio_weight) { 197 kprintf("invalid weight value %d for red! use %d\n", 198 rp->rio_weight, w); 199 rp->rio_weight = w; 200 } 201 202 /* allocate weight table */ 203 rp->rio_wtab = wtab_alloc(rp->rio_weight); 204 205 for (i = 0; i < RIO_NDROPPREC; i++) { 206 struct dropprec_state *prec = &rp->rio_precstate[i]; 207 208 prec->avg = 0; 209 prec->idle = 1; 210 211 if (params == NULL || params[i].inv_pmax == 0) 212 prec->inv_pmax = default_rio_params[i].inv_pmax; 213 else 214 prec->inv_pmax = params[i].inv_pmax; 215 if (params == NULL || params[i].th_min == 0) 216 prec->th_min = default_rio_params[i].th_min; 217 else 218 prec->th_min = params[i].th_min; 219 if (params == NULL || params[i].th_max == 0) 220 prec->th_max = default_rio_params[i].th_max; 221 else 222 prec->th_max = params[i].th_max; 223 224 /* 225 * th_min_s and th_max_s are scaled versions of th_min 226 * and th_max to be compared with avg. 227 */ 228 prec->th_min_s = prec->th_min << (rp->rio_wshift + FP_SHIFT); 229 prec->th_max_s = prec->th_max << (rp->rio_wshift + FP_SHIFT); 230 231 /* 232 * precompute probability denominator 233 * probd = (2 * (TH_MAX-TH_MIN) / pmax) in fixed-point 234 */ 235 prec->probd = (2 * (prec->th_max - prec->th_min) 236 * prec->inv_pmax) << FP_SHIFT; 237 238 microtime(&prec->last); 239 } 240 241 return (rp); 242 } 243 244 void 245 rio_destroy(rio_t *rp) 246 { 247 wtab_destroy(rp->rio_wtab); 248 kfree(rp, M_ALTQ); 249 } 250 251 void 252 rio_getstats(rio_t *rp, struct redstats *sp) 253 { 254 int i; 255 256 for (i = 0; i < RIO_NDROPPREC; i++) { 257 bcopy(&rp->q_stats[i], sp, sizeof(struct redstats)); 258 sp->q_avg = rp->rio_precstate[i].avg >> rp->rio_wshift; 259 sp++; 260 } 261 } 262 263 #if (RIO_NDROPPREC == 3) 264 /* 265 * internally, a drop precedence value is converted to an index 266 * starting from 0. 267 */ 268 static int 269 dscp2index(uint8_t dscp) 270 { 271 int dpindex = dscp & AF_DROPPRECMASK; 272 273 if (dpindex == 0) 274 return (0); 275 return ((dpindex >> 3) - 1); 276 } 277 #endif 278 279 #if 1 280 /* 281 * kludge: when a packet is dequeued, we need to know its drop precedence 282 * in order to keep the queue length of each drop precedence. 283 * use m_pkthdr.rcvif to pass this info. 284 */ 285 #define RIOM_SET_PRECINDEX(m, idx) \ 286 do { (m)->m_pkthdr.rcvif = (struct ifnet *)((long)(idx)); } while (0) 287 #define RIOM_GET_PRECINDEX(m) \ 288 ({ long idx; idx = (long)((m)->m_pkthdr.rcvif); \ 289 (m)->m_pkthdr.rcvif = NULL; idx; }) 290 #endif 291 292 int 293 rio_addq(rio_t *rp, class_queue_t *q, struct mbuf *m, struct altq_pktattr *pktattr) 294 { 295 int avg, droptype; 296 uint8_t dsfield, odsfield; 297 int dpindex, i, n, t; 298 struct timeval now; 299 struct dropprec_state *prec; 300 301 dsfield = odsfield = read_dsfield(m, pktattr); 302 dpindex = dscp2index(dsfield); 303 304 /* 305 * update avg of the precedence states whose drop precedence 306 * is larger than or equal to the drop precedence of the packet 307 */ 308 now.tv_sec = 0; 309 for (i = dpindex; i < RIO_NDROPPREC; i++) { 310 prec = &rp->rio_precstate[i]; 311 avg = prec->avg; 312 if (prec->idle) { 313 prec->idle = 0; 314 if (now.tv_sec == 0) 315 microtime(&now); 316 t = (now.tv_sec - prec->last.tv_sec); 317 if (t > 60) 318 avg = 0; 319 else { 320 t = t * 1000000 + 321 (now.tv_usec - prec->last.tv_usec); 322 n = t / rp->rio_pkttime; 323 /* calculate (avg = (1 - Wq)^n * avg) */ 324 if (n > 0) 325 avg = (avg >> FP_SHIFT) * 326 pow_w(rp->rio_wtab, n); 327 } 328 } 329 330 /* run estimator. (avg is scaled by WEIGHT in fixed-point) */ 331 avg += (prec->qlen << FP_SHIFT) - (avg >> rp->rio_wshift); 332 prec->avg = avg; /* save the new value */ 333 /* 334 * count keeps a tally of arriving traffic that has not 335 * been dropped. 336 */ 337 prec->count++; 338 } 339 340 prec = &rp->rio_precstate[dpindex]; 341 avg = prec->avg; 342 343 /* see if we drop early */ 344 droptype = DTYPE_NODROP; 345 if (avg >= prec->th_min_s && prec->qlen > 1) { 346 if (avg >= prec->th_max_s) { 347 /* avg >= th_max: forced drop */ 348 droptype = DTYPE_FORCED; 349 } else if (prec->old == 0) { 350 /* first exceeds th_min */ 351 prec->count = 1; 352 prec->old = 1; 353 } else if (drop_early((avg - prec->th_min_s) >> rp->rio_wshift, 354 prec->probd, prec->count)) { 355 /* unforced drop by red */ 356 droptype = DTYPE_EARLY; 357 } 358 } else { 359 /* avg < th_min */ 360 prec->old = 0; 361 } 362 363 /* 364 * if the queue length hits the hard limit, it's a forced drop. 365 */ 366 if (droptype == DTYPE_NODROP && qlen(q) >= qlimit(q)) 367 droptype = DTYPE_FORCED; 368 369 if (droptype != DTYPE_NODROP) { 370 /* always drop incoming packet (as opposed to randomdrop) */ 371 for (i = dpindex; i < RIO_NDROPPREC; i++) 372 rp->rio_precstate[i].count = 0; 373 #ifdef RIO_STATS 374 if (droptype == DTYPE_EARLY) 375 rp->q_stats[dpindex].drop_unforced++; 376 else 377 rp->q_stats[dpindex].drop_forced++; 378 PKTCNTR_ADD(&rp->q_stats[dpindex].drop_cnt, m_pktlen(m)); 379 #endif 380 m_freem(m); 381 return (-1); 382 } 383 384 for (i = dpindex; i < RIO_NDROPPREC; i++) 385 rp->rio_precstate[i].qlen++; 386 387 /* save drop precedence index in mbuf hdr */ 388 RIOM_SET_PRECINDEX(m, dpindex); 389 390 if (rp->rio_flags & RIOF_CLEARDSCP) 391 dsfield &= ~DSCP_MASK; 392 393 if (dsfield != odsfield) 394 write_dsfield(m, pktattr, dsfield); 395 396 _addq(q, m); 397 398 #ifdef RIO_STATS 399 PKTCNTR_ADD(&rp->q_stats[dpindex].xmit_cnt, m_pktlen(m)); 400 #endif 401 return (0); 402 } 403 404 struct mbuf * 405 rio_getq(rio_t *rp, class_queue_t *q) 406 { 407 struct mbuf *m; 408 int dpindex, i; 409 410 if ((m = _getq(q)) == NULL) 411 return (NULL); 412 413 dpindex = RIOM_GET_PRECINDEX(m); 414 for (i = dpindex; i < RIO_NDROPPREC; i++) { 415 if (--rp->rio_precstate[i].qlen == 0) { 416 if (rp->rio_precstate[i].idle == 0) { 417 rp->rio_precstate[i].idle = 1; 418 microtime(&rp->rio_precstate[i].last); 419 } 420 } 421 } 422 return (m); 423 } 424 425 #endif /* ALTQ_RIO */ 426