Annotation of sys/altq/altq_rio.c, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: altq_rio.c,v 1.10 2007/06/17 19:58:58 jasper Exp $ */
! 2: /* $KAME: altq_rio.c,v 1.8 2000/12/14 08:12:46 thorpej Exp $ */
! 3:
! 4: /*
! 5: * Copyright (C) 1998-2000
! 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 <sys/param.h>
! 63: #include <sys/malloc.h>
! 64: #include <sys/mbuf.h>
! 65: #include <sys/socket.h>
! 66: #include <sys/systm.h>
! 67: #include <sys/errno.h>
! 68:
! 69: #include <net/if.h>
! 70: #include <net/if_types.h>
! 71:
! 72: #include <netinet/in.h>
! 73: #include <netinet/in_systm.h>
! 74: #include <netinet/ip.h>
! 75: #ifdef INET6
! 76: #include <netinet/ip6.h>
! 77: #endif
! 78:
! 79: #include <net/pfvar.h>
! 80: #include <altq/altq.h>
! 81: #include <altq/altq_cdnr.h>
! 82: #include <altq/altq_red.h>
! 83: #include <altq/altq_rio.h>
! 84:
! 85: /*
! 86: * RIO: RED with IN/OUT bit
! 87: * described in
! 88: * "Explicit Allocation of Best Effort Packet Delivery Service"
! 89: * David D. Clark and Wenjia Fang, MIT Lab for Computer Science
! 90: * http://diffserv.lcs.mit.edu/Papers/exp-alloc-ddc-wf.{ps,pdf}
! 91: *
! 92: * this implementation is extended to support more than 2 drop precedence
! 93: * values as described in RFC2597 (Assured Forwarding PHB Group).
! 94: *
! 95: */
! 96: /*
! 97: * AF DS (differentiated service) codepoints.
! 98: * (classes can be mapped to CBQ or H-FSC classes.)
! 99: *
! 100: * 0 1 2 3 4 5 6 7
! 101: * +---+---+---+---+---+---+---+---+
! 102: * | CLASS |DropPre| 0 | CU |
! 103: * +---+---+---+---+---+---+---+---+
! 104: *
! 105: * class 1: 001
! 106: * class 2: 010
! 107: * class 3: 011
! 108: * class 4: 100
! 109: *
! 110: * low drop prec: 01
! 111: * medium drop prec: 10
! 112: * high drop prec: 01
! 113: */
! 114:
! 115: /* normal red parameters */
! 116: #define W_WEIGHT 512 /* inverse of weight of EWMA (511/512) */
! 117: /* q_weight = 0.00195 */
! 118:
! 119: /* red parameters for a slow link */
! 120: #define W_WEIGHT_1 128 /* inverse of weight of EWMA (127/128) */
! 121: /* q_weight = 0.0078125 */
! 122:
! 123: /* red parameters for a very slow link (e.g., dialup) */
! 124: #define W_WEIGHT_2 64 /* inverse of weight of EWMA (63/64) */
! 125: /* q_weight = 0.015625 */
! 126:
! 127: /* fixed-point uses 12-bit decimal places */
! 128: #define FP_SHIFT 12 /* fixed-point shift */
! 129:
! 130: /* red parameters for drop probability */
! 131: #define INV_P_MAX 10 /* inverse of max drop probability */
! 132: #define TH_MIN 5 /* min threshold */
! 133: #define TH_MAX 15 /* max threshold */
! 134:
! 135: #define RIO_LIMIT 60 /* default max queue length */
! 136: #define RIO_STATS /* collect statistics */
! 137:
! 138: #define TV_DELTA(a, b, delta) { \
! 139: int xxs; \
! 140: \
! 141: delta = (a)->tv_usec - (b)->tv_usec; \
! 142: if ((xxs = (a)->tv_sec - (b)->tv_sec) != 0) { \
! 143: if (xxs < 0) { \
! 144: delta = 60000000; \
! 145: } else if (xxs > 4) { \
! 146: if (xxs > 60) \
! 147: delta = 60000000; \
! 148: else \
! 149: delta += xxs * 1000000; \
! 150: } else while (xxs > 0) { \
! 151: delta += 1000000; \
! 152: xxs--; \
! 153: } \
! 154: } \
! 155: }
! 156:
! 157: /* default rio parameter values */
! 158: static struct redparams default_rio_params[RIO_NDROPPREC] = {
! 159: /* th_min, th_max, inv_pmax */
! 160: { TH_MAX * 2 + TH_MIN, TH_MAX * 3, INV_P_MAX }, /* low drop precedence */
! 161: { TH_MAX + TH_MIN, TH_MAX * 2, INV_P_MAX }, /* medium drop precedence */
! 162: { TH_MIN, TH_MAX, INV_P_MAX } /* high drop precedence */
! 163: };
! 164:
! 165: /* internal function prototypes */
! 166: static int dscp2index(u_int8_t);
! 167:
! 168: rio_t *
! 169: rio_alloc(int weight, struct redparams *params, int flags, int pkttime)
! 170: {
! 171: rio_t *rp;
! 172: int w, i;
! 173: int npkts_per_sec;
! 174:
! 175: MALLOC(rp, rio_t *, sizeof(rio_t), M_DEVBUF, M_WAITOK);
! 176: if (rp == NULL)
! 177: return (NULL);
! 178: bzero(rp, sizeof(rio_t));
! 179:
! 180: rp->rio_flags = flags;
! 181: if (pkttime == 0)
! 182: /* default packet time: 1000 bytes / 10Mbps * 8 * 1000000 */
! 183: rp->rio_pkttime = 800;
! 184: else
! 185: rp->rio_pkttime = pkttime;
! 186:
! 187: if (weight != 0)
! 188: rp->rio_weight = weight;
! 189: else {
! 190: /* use default */
! 191: rp->rio_weight = W_WEIGHT;
! 192:
! 193: /* when the link is very slow, adjust red parameters */
! 194: npkts_per_sec = 1000000 / rp->rio_pkttime;
! 195: if (npkts_per_sec < 50) {
! 196: /* up to about 400Kbps */
! 197: rp->rio_weight = W_WEIGHT_2;
! 198: } else if (npkts_per_sec < 300) {
! 199: /* up to about 2.4Mbps */
! 200: rp->rio_weight = W_WEIGHT_1;
! 201: }
! 202: }
! 203:
! 204: /* calculate wshift. weight must be power of 2 */
! 205: w = rp->rio_weight;
! 206: for (i = 0; w > 1; i++)
! 207: w = w >> 1;
! 208: rp->rio_wshift = i;
! 209: w = 1 << rp->rio_wshift;
! 210: if (w != rp->rio_weight) {
! 211: printf("invalid weight value %d for red! use %d\n",
! 212: rp->rio_weight, w);
! 213: rp->rio_weight = w;
! 214: }
! 215:
! 216: /* allocate weight table */
! 217: rp->rio_wtab = wtab_alloc(rp->rio_weight);
! 218:
! 219: for (i = 0; i < RIO_NDROPPREC; i++) {
! 220: struct dropprec_state *prec = &rp->rio_precstate[i];
! 221:
! 222: prec->avg = 0;
! 223: prec->idle = 1;
! 224:
! 225: if (params == NULL || params[i].inv_pmax == 0)
! 226: prec->inv_pmax = default_rio_params[i].inv_pmax;
! 227: else
! 228: prec->inv_pmax = params[i].inv_pmax;
! 229: if (params == NULL || params[i].th_min == 0)
! 230: prec->th_min = default_rio_params[i].th_min;
! 231: else
! 232: prec->th_min = params[i].th_min;
! 233: if (params == NULL || params[i].th_max == 0)
! 234: prec->th_max = default_rio_params[i].th_max;
! 235: else
! 236: prec->th_max = params[i].th_max;
! 237:
! 238: /*
! 239: * th_min_s and th_max_s are scaled versions of th_min
! 240: * and th_max to be compared with avg.
! 241: */
! 242: prec->th_min_s = prec->th_min << (rp->rio_wshift + FP_SHIFT);
! 243: prec->th_max_s = prec->th_max << (rp->rio_wshift + FP_SHIFT);
! 244:
! 245: /*
! 246: * precompute probability denominator
! 247: * probd = (2 * (TH_MAX-TH_MIN) / pmax) in fixed-point
! 248: */
! 249: prec->probd = (2 * (prec->th_max - prec->th_min)
! 250: * prec->inv_pmax) << FP_SHIFT;
! 251:
! 252: microtime(&prec->last);
! 253: }
! 254:
! 255: return (rp);
! 256: }
! 257:
! 258: void
! 259: rio_destroy(rio_t *rp)
! 260: {
! 261: wtab_destroy(rp->rio_wtab);
! 262: FREE(rp, M_DEVBUF);
! 263: }
! 264:
! 265: void
! 266: rio_getstats(rio_t *rp, struct redstats *sp)
! 267: {
! 268: int i;
! 269:
! 270: for (i = 0; i < RIO_NDROPPREC; i++) {
! 271: bcopy(&rp->q_stats[i], sp, sizeof(struct redstats));
! 272: sp->q_avg = rp->rio_precstate[i].avg >> rp->rio_wshift;
! 273: sp++;
! 274: }
! 275: }
! 276:
! 277: #if (RIO_NDROPPREC == 3)
! 278: /*
! 279: * internally, a drop precedence value is converted to an index
! 280: * starting from 0.
! 281: */
! 282: static int
! 283: dscp2index(u_int8_t dscp)
! 284: {
! 285: int dpindex = dscp & AF_DROPPRECMASK;
! 286:
! 287: if (dpindex == 0)
! 288: return (0);
! 289: return ((dpindex >> 3) - 1);
! 290: }
! 291: #endif
! 292:
! 293: #if 1
! 294: /*
! 295: * kludge: when a packet is dequeued, we need to know its drop precedence
! 296: * in order to keep the queue length of each drop precedence.
! 297: * use m_pkthdr.rcvif to pass this info.
! 298: */
! 299: #define RIOM_SET_PRECINDEX(m, idx) \
! 300: do { (m)->m_pkthdr.rcvif = (struct ifnet *)((long)(idx)); } while (0)
! 301: #define RIOM_GET_PRECINDEX(m) \
! 302: ({ long idx; idx = (long)((m)->m_pkthdr.rcvif); \
! 303: (m)->m_pkthdr.rcvif = NULL; idx; })
! 304: #endif
! 305:
! 306: int
! 307: rio_addq(rio_t *rp, class_queue_t *q, struct mbuf *m,
! 308: struct altq_pktattr *pktattr)
! 309: {
! 310: int avg, droptype;
! 311: u_int8_t dsfield, odsfield;
! 312: int dpindex, i, n, t;
! 313: struct timeval now;
! 314: struct dropprec_state *prec;
! 315:
! 316: dsfield = odsfield = read_dsfield(m, pktattr);
! 317: dpindex = dscp2index(dsfield);
! 318:
! 319: /*
! 320: * update avg of the precedence states whose drop precedence
! 321: * is larger than or equal to the drop precedence of the packet
! 322: */
! 323: now.tv_sec = 0;
! 324: for (i = dpindex; i < RIO_NDROPPREC; i++) {
! 325: prec = &rp->rio_precstate[i];
! 326: avg = prec->avg;
! 327: if (prec->idle) {
! 328: prec->idle = 0;
! 329: if (now.tv_sec == 0)
! 330: microtime(&now);
! 331: t = (now.tv_sec - prec->last.tv_sec);
! 332: if (t > 60)
! 333: avg = 0;
! 334: else {
! 335: t = t * 1000000 +
! 336: (now.tv_usec - prec->last.tv_usec);
! 337: n = t / rp->rio_pkttime;
! 338: /* calculate (avg = (1 - Wq)^n * avg) */
! 339: if (n > 0)
! 340: avg = (avg >> FP_SHIFT) *
! 341: pow_w(rp->rio_wtab, n);
! 342: }
! 343: }
! 344:
! 345: /* run estimator. (avg is scaled by WEIGHT in fixed-point) */
! 346: avg += (prec->qlen << FP_SHIFT) - (avg >> rp->rio_wshift);
! 347: prec->avg = avg; /* save the new value */
! 348: /*
! 349: * count keeps a tally of arriving traffic that has not
! 350: * been dropped.
! 351: */
! 352: prec->count++;
! 353: }
! 354:
! 355: prec = &rp->rio_precstate[dpindex];
! 356: avg = prec->avg;
! 357:
! 358: /* see if we drop early */
! 359: droptype = DTYPE_NODROP;
! 360: if (avg >= prec->th_min_s && prec->qlen > 1) {
! 361: if (avg >= prec->th_max_s) {
! 362: /* avg >= th_max: forced drop */
! 363: droptype = DTYPE_FORCED;
! 364: } else if (prec->old == 0) {
! 365: /* first exceeds th_min */
! 366: prec->count = 1;
! 367: prec->old = 1;
! 368: } else if (drop_early((avg - prec->th_min_s) >> rp->rio_wshift,
! 369: prec->probd, prec->count)) {
! 370: /* unforced drop by red */
! 371: droptype = DTYPE_EARLY;
! 372: }
! 373: } else {
! 374: /* avg < th_min */
! 375: prec->old = 0;
! 376: }
! 377:
! 378: /*
! 379: * if the queue length hits the hard limit, it's a forced drop.
! 380: */
! 381: if (droptype == DTYPE_NODROP && qlen(q) >= qlimit(q))
! 382: droptype = DTYPE_FORCED;
! 383:
! 384: if (droptype != DTYPE_NODROP) {
! 385: /* always drop incoming packet (as opposed to randomdrop) */
! 386: for (i = dpindex; i < RIO_NDROPPREC; i++)
! 387: rp->rio_precstate[i].count = 0;
! 388: #ifdef RIO_STATS
! 389: if (droptype == DTYPE_EARLY)
! 390: rp->q_stats[dpindex].drop_unforced++;
! 391: else
! 392: rp->q_stats[dpindex].drop_forced++;
! 393: PKTCNTR_ADD(&rp->q_stats[dpindex].drop_cnt, m_pktlen(m));
! 394: #endif
! 395: m_freem(m);
! 396: return (-1);
! 397: }
! 398:
! 399: for (i = dpindex; i < RIO_NDROPPREC; i++)
! 400: rp->rio_precstate[i].qlen++;
! 401:
! 402: /* save drop precedence index in mbuf hdr */
! 403: RIOM_SET_PRECINDEX(m, dpindex);
! 404:
! 405: if (rp->rio_flags & RIOF_CLEARDSCP)
! 406: dsfield &= ~DSCP_MASK;
! 407:
! 408: if (dsfield != odsfield)
! 409: write_dsfield(m, pktattr, dsfield);
! 410:
! 411: _addq(q, m);
! 412:
! 413: #ifdef RIO_STATS
! 414: PKTCNTR_ADD(&rp->q_stats[dpindex].xmit_cnt, m_pktlen(m));
! 415: #endif
! 416: return (0);
! 417: }
! 418:
! 419: struct mbuf *
! 420: rio_getq(rio_t *rp, class_queue_t *q)
! 421: {
! 422: struct mbuf *m;
! 423: int dpindex, i;
! 424:
! 425: if ((m = _getq(q)) == NULL)
! 426: return NULL;
! 427:
! 428: dpindex = RIOM_GET_PRECINDEX(m);
! 429: for (i = dpindex; i < RIO_NDROPPREC; i++) {
! 430: if (--rp->rio_precstate[i].qlen == 0) {
! 431: if (rp->rio_precstate[i].idle == 0) {
! 432: rp->rio_precstate[i].idle = 1;
! 433: microtime(&rp->rio_precstate[i].last);
! 434: }
! 435: }
! 436: }
! 437: return (m);
! 438: }
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