1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #include <sys/types.h> 28 #include <sys/kmem.h> 29 #include <sys/random.h> 30 #include <netinet/in.h> 31 #include <netinet/in_systm.h> 32 #include <netinet/ip6.h> 33 #include <inet/common.h> 34 #include <inet/ip.h> 35 #include <inet/ip6.h> 36 #include <ipp/meters/meter_impl.h> 37 38 /* 39 * Module : Time Sliding Window meter - tswtclmtr 40 * Description 41 * This module implements the metering part of RFC 2859. It accepts the 42 * committed rate, peak rate and the window for a flow and determines 43 * if the flow is within the committed/peak rate and assigns the appropriate 44 * next action. 45 * The meter provides an estimate of the running average bandwidth for the 46 * flow over the specified window. It uses probability to benefit TCP flows 47 * as it reduces the likelihood of dropping multiple packets within a TCP 48 * window without adversely effecting UDP flows. 49 */ 50 51 int tswtcl_debug = 0; 52 53 /* 54 * Given a packet and the tswtcl_data it belongs to, this routine meters the 55 * ToS or DSCP for IPv4 and IPv6 resp. with the values configured for 56 * the tswtcl_data. 57 */ 58 /* ARGSUSED */ 59 int 60 tswtcl_process(mblk_t **mpp, tswtcl_data_t *tswtcl_data, 61 ipp_action_id_t *next_action) 62 { 63 ipha_t *ipha; 64 hrtime_t now; 65 ip6_t *ip6_hdr; 66 uint32_t pkt_len; 67 mblk_t *mp = *mpp; 68 hrtime_t deltaT; 69 uint64_t bitsinwin; 70 uint32_t min = 0, additive, rnd; 71 tswtcl_cfg_t *cfg_parms = tswtcl_data->cfg_parms; 72 73 if (mp == NULL) { 74 tswtcl0dbg(("tswtcl_process: null mp!\n")); 75 atomic_inc_64(&tswtcl_data->epackets); 76 return (EINVAL); 77 } 78 79 if (mp->b_datap->db_type != M_DATA) { 80 if ((mp->b_cont != NULL) && 81 (mp->b_cont->b_datap->db_type == M_DATA)) { 82 mp = mp->b_cont; 83 } else { 84 tswtcl0dbg(("tswtcl_process: no data\n")); 85 atomic_inc_64(&tswtcl_data->epackets); 86 return (EINVAL); 87 } 88 } 89 90 /* Figure out the ToS/Traffic Class and length from the message */ 91 if ((mp->b_wptr - mp->b_rptr) < IP_SIMPLE_HDR_LENGTH) { 92 if (!pullupmsg(mp, IP_SIMPLE_HDR_LENGTH)) { 93 tswtcl0dbg(("tswtcl_process: pullup error\n")); 94 atomic_inc_64(&tswtcl_data->epackets); 95 return (EINVAL); 96 } 97 } 98 ipha = (ipha_t *)mp->b_rptr; 99 if (IPH_HDR_VERSION(ipha) == IPV4_VERSION) { 100 pkt_len = ntohs(ipha->ipha_length); 101 } else { 102 ip6_hdr = (ip6_t *)mp->b_rptr; 103 pkt_len = ntohs(ip6_hdr->ip6_plen) + 104 ip_hdr_length_v6(mp, ip6_hdr); 105 } 106 107 /* Convert into bits */ 108 pkt_len <<= 3; 109 110 /* Get current time */ 111 now = gethrtime(); 112 113 /* Update the avg_rate and win_front tswtcl_data */ 114 mutex_enter(&tswtcl_data->tswtcl_lock); 115 116 /* avg_rate = bits/sec and window in msec */ 117 bitsinwin = ((uint64_t)tswtcl_data->avg_rate * cfg_parms->window / 118 1000) + pkt_len; 119 120 deltaT = now - tswtcl_data->win_front + cfg_parms->nsecwindow; 121 122 tswtcl_data->avg_rate = (uint64_t)bitsinwin * METER_SEC_TO_NSEC / 123 deltaT; 124 tswtcl_data->win_front = now; 125 126 if (tswtcl_data->avg_rate <= cfg_parms->committed_rate) { 127 *next_action = cfg_parms->green_action; 128 } else if (tswtcl_data->avg_rate <= cfg_parms->peak_rate) { 129 /* 130 * Compute the probability: 131 * 132 * p0 = (avg_rate - committed_rate) / avg_rate 133 * 134 * Yellow with probability p0 135 * Green with probability (1 - p0) 136 * 137 */ 138 uint32_t aminusc; 139 140 /* Get a random no. betweeen 0 and avg_rate */ 141 (void) random_get_pseudo_bytes((uint8_t *)&additive, 142 sizeof (additive)); 143 rnd = min + (additive % (tswtcl_data->avg_rate - min + 1)); 144 145 aminusc = tswtcl_data->avg_rate - cfg_parms->committed_rate; 146 if (aminusc >= rnd) { 147 *next_action = cfg_parms->yellow_action; 148 } else { 149 *next_action = cfg_parms->green_action; 150 } 151 } else { 152 /* 153 * Compute the probability: 154 * 155 * p1 = (avg_rate - peak_rate) / avg_rate 156 * p2 = (peak_rate - committed_rate) / avg_rate 157 * 158 * Red with probability p1 159 * Yellow with probability p2 160 * Green with probability (1 - (p1 + p2)) 161 * 162 */ 163 uint32_t aminusp; 164 165 /* Get a random no. betweeen 0 and avg_rate */ 166 (void) random_get_pseudo_bytes((uint8_t *)&additive, 167 sizeof (additive)); 168 rnd = min + (additive % (tswtcl_data->avg_rate - min + 1)); 169 170 aminusp = tswtcl_data->avg_rate - cfg_parms->peak_rate; 171 172 if (aminusp >= rnd) { 173 *next_action = cfg_parms->red_action; 174 } else if ((cfg_parms->pminusc + aminusp) >= rnd) { 175 *next_action = cfg_parms->yellow_action; 176 } else { 177 *next_action = cfg_parms->green_action; 178 } 179 180 } 181 mutex_exit(&tswtcl_data->tswtcl_lock); 182 183 /* Update Stats */ 184 if (*next_action == cfg_parms->green_action) { 185 atomic_inc_64(&tswtcl_data->green_packets); 186 atomic_add_64(&tswtcl_data->green_bits, pkt_len); 187 } else if (*next_action == cfg_parms->yellow_action) { 188 atomic_inc_64(&tswtcl_data->yellow_packets); 189 atomic_add_64(&tswtcl_data->yellow_bits, pkt_len); 190 } else { 191 ASSERT(*next_action == cfg_parms->red_action); 192 atomic_inc_64(&tswtcl_data->red_packets); 193 atomic_add_64(&tswtcl_data->red_bits, pkt_len); 194 } 195 return (0); 196 } 197