fwp/mngr/fwp_admctrl.c

   1 /**************************************************************************/
   2 /* ---------------------------------------------------------------------- */
   3 /* Copyright (C) 2006 - 2008 FRESCOR consortium partners:                 */
   4 /*                                                                        */
   5 /*   Universidad de Cantabria,              SPAIN                         */
   6 /*   University of York,                    UK                            */
   7 /*   Scuola Superiore Sant'Anna,            ITALY                         */
   8 /*   Kaiserslautern University,             GERMANY                       */
   9 /*   Univ. Politécnica  Valencia,           SPAIN                        */
  10 /*   Czech Technical University in Prague,  CZECH REPUBLIC                */
  11 /*   ENEA                                   SWEDEN                        */
  12 /*   Thales Communication S.A.              FRANCE                        */
  13 /*   Visual Tools S.A.                      SPAIN                         */
  14 /*   Rapita Systems Ltd                     UK                            */
  15 /*   Evidence                               ITALY                         */
  16 /*                                                                        */
  17 /*   See http://www.frescor.org for a link to partners' websites          */
  18 /*                                                                        */
  19 /*          FRESCOR project (FP6/2005/IST/5-034026) is funded             */
  20 /*       in part by the European Union Sixth Framework Programme          */
  21 /*       The European Union is not liable of any use that may be          */
  22 /*       made of this code.                                               */
  23 /*                                                                        */
  24 /*                                                                        */
  25 /*  This file is part of FWP (Frescor WLAN Protocol)                      */
  26 /*                                                                        */
  27 /* FWP is free software; you can redistribute it and/or modify it         */
  28 /* under terms of the GNU General Public License as published by the      */
  29 /* Free Software Foundation; either version 2, or (at your option) any    */
  30 /* later version.  FWP is distributed in the hope that it will be         */
  31 /* useful, but WITHOUT ANY WARRANTY; without even the implied warranty    */
  32 /* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU    */
  33 /* General Public License for more details. You should have received a    */
  34 /* copy of the GNU General Public License along with FWP; see file        */
  35 /* COPYING. If not, write to the Free Software Foundation, 675 Mass Ave,  */
  36 /* Cambridge, MA 02139, USA.                                              */
  37 /*                                                                        */
  38 /* As a special exception, including FWP header files in a file,          */
  39 /* instantiating FWP generics or templates, or linking other files        */
  40 /* with FWP objects to produce an executable application, does not        */
  41 /* by itself cause the resulting executable application to be covered     */
  42 /* by the GNU General Public License. This exception does not             */
  43 /* however invalidate any other reasons why the executable file might be  */
  44 /* covered by the GNU Public License.                                     */
  45 /**************************************************************************/
  46 #include <fres_sa_scenario.h>
  47 #include <fwp.h>
  48 #include "fwp_idl.h"
  49 #include "fwp_admctrl.h"
  50
  51 /* TODO: Find out the real value and determine what influences it (MTU
  52  *       of the interface minus header sizes?).  */
  53 #define MTU 1472
  54 #define UDP_HEADER_SIZE 8
  55 #define IP_HEADER_SIZE 20
  56 #define LLC_HEADER_SIZE 2       /* ??? */
  57 #define MAC_HEADER_SIZE 26      /* With QoS field added */
  58 #define MAC_FCS_SIZE 4
  59
  60 #define RTS_FRAME_SIZE 20
  61 #define CTS_FRAME_SIZE 14
  62 #define ACK_FRAME_SIZE 14
  63
  64 #define ASLOTTIME_USEC 20       /* 802.11g-2003 p. 46 */
  65 #define ASIFSTIME_USEC 10
  66 #define ADIFSTIME_USEC (ASIFSTIME_USEC + 2*ASLOTTIME_USEC)
  67 #define AAIFSTIME_USEC(n) (ASIFSTIME_USEC + (n)*ASLOTTIME_USEC)
  68
  69 /* Default values from 802.11e */
  70 const int aifsn[FWP_AC_NUM] = { 2, 2, 3, 7 };
  71 const int cwmin[FWP_AC_NUM] = { 3, 7, 15, 15 };
  72
  73 /* Experimental konstants - weight of backoff */
  74 const int pisvejc[FWP_AC_NUM] = { 6, 5, 2, 2 };
  75
  76 int fwp_reserved_utilization;
  77
  78 /**
  79  * Calucaltes frame duration in microseconds. If the real duration is
  80  * represented by a fractional number, the value is rounded up.
  81  *
  82  * @param length Number of bytes in PSDU.
  83  * @param rate_bps Transmit rate of PSDU. The rate should correspond
  84  *            to other parameters accoring to 19.3.2 (802.11g)
  85  * @param erp_ofdm Whether Extended Rate PHY (part of 802.11g) and ERP-OFDM
  86  *            modulation is used.
  87  * @param short_preamble Whether short preamble (HR/DSSS/short) is
  88  *            used (802.11b)
  89  *
  90  * @return The number of microseconds or a negative number in case of error.
  91  */
  92 static int frame_duration(uint16_t length, int rate_bps, bool erp_ofdm, bool short_preamble)
  93 {
  94         uint32_t duration_usec = 0;
  95
  96         if (!erp_ofdm) {
  97                 duration_usec = ((int64_t)(length) * 8 * SEC_TO_USEC / rate_bps);
  98                 if (short_preamble) {
  99                         /* For HR/DSSS/short (2, 5.5 and 11 Mbit,
 100                          * 802.11b-1999), also for DSSS-OFDM rates and
 101                          * ERP-PBCC rates.
 102                          * Preamble sent at 1 MBit, header at 2 Mbit */
 103                         duration_usec += 72/*bits*/+48/*bits*//2;
 104                 } else {
 105                         /* For DSSS PHY (1 and 2 Mbit rates,
 106                          * 802.11-1999) and for DSS-OFDM and ERP-PBCC
 107                          * rates. Always sent at 1 MBit */
 108                         duration_usec += 144/*bits*/+48/*bits*/;
 109                 }
 110         } else {
 111 #define MBIT_TO_INDEX(rate_Mbps)  ((rate_Mbps)/3 - 2)
 112                 const int N_dbps[] = {
 113                         [MBIT_TO_INDEX(6)] = 24,
 114                         [MBIT_TO_INDEX(9)] = 36,
 115                         [MBIT_TO_INDEX(12)] = 48,
 116                         [MBIT_TO_INDEX(18)] = 72,
 117                         [MBIT_TO_INDEX(24)] = 96,
 118                         [MBIT_TO_INDEX(36)] = 144,
 119                         [MBIT_TO_INDEX(48)] = 192,
 120                         [MBIT_TO_INDEX(54)] = 216
 121                 };
 122                 int rate_idx = MBIT_TO_INDEX(rate_bps/1000/1000);
 123 #undef MBIT_TO_INDEX
 124                 if (rate_idx < 0 ||
 125                     rate_idx >= sizeof(N_dbps)/sizeof(*N_dbps) ||
 126                     N_dbps[rate_idx] == 0)
 127                         return -1;
 128
 129                 duration_usec += 16 + 4; /* Preamble, SIGNAL */
 130                 int bits =
 131                         16 +        /* SERVICE */
 132                         length * 8 +
 133                         6;          /* tail bits */
 134                 int Nsym = (bits + N_dbps[rate_idx] - 1)/N_dbps[rate_idx];
 135
 136                 duration_usec += Nsym * 4;
 137
 138                 duration_usec += 6; /* signal extension */
 139         }
 140         return duration_usec;
 141 }
 142
 143 int fwp_admctrl_utilization(struct fres_sa_scenario *scenario, void *priv,
 144                                 bool *schedulable)
 145 {
 146         int utilization = 0;
 147
 148         const int rate = 22*1000*1000;
 149         const bool erp_ofdm = false;
 150         const bool short_preamble = false;
 151         struct fres_sa_contract *c, *c_new = NULL;
 152         long int period_usec;
 153         fres_block_basic *basic;
 154         fres_block_fwp_sched *fwp_sched;
 155
 156         size_t bytes;
 157         long int duration_usec, tmp_usec;
 158         int fragments;
 159         int ac = FWP_AC_VO;
 160
 161         fres_sa_scenario_for_each_contract(scenario, c) {
 162                 fres_block_basic *basic;
 163                 char id[40];
 164                 fres_contract_id_to_string(id, &c->contract->id, sizeof(id));
 165                 basic = fres_contract_get_basic(c->contract);
 166
 167                 frsh_network_budget_to_bytes(FRSH_NETPF_FWP,&basic->budget,&bytes);
 168                 printf("  processing: id=%s, period=%ld ms, budget=%lu bytes\n",
 169                        id,
 170                        fosa_rel_time_to_msec(basic->period),
 171                        (long unsigned int)bytes);
 172
 173                 /* Calculate protocol overhead */
 174                 fragments = (bytes + MTU - 1) / MTU;
 175
 176                 if (fragments == 0)
 177                         continue;
 178
 179                 const int data_overhead = UDP_HEADER_SIZE + IP_HEADER_SIZE +
 180                         LLC_HEADER_SIZE + MAC_FCS_SIZE;
 181
 182                 duration_usec = frame_duration(data_overhead + bytes%MTU, rate,
 183                                                 erp_ofdm, short_preamble);
 184                 tmp_usec = frame_duration(data_overhead + MTU, rate, erp_ofdm,
 185                                                 short_preamble);
 186                 duration_usec += tmp_usec*(fragments-1);
 187                 /* Add average backoff - assume there is no collision */
 188                 tmp_usec = ASLOTTIME_USEC*fragments*pisvejc[ac];
 189                 duration_usec += (aifsn[ac] + cwmin[ac]/2)*tmp_usec;
 190                 /* We use ACK and ignore burst */
 191                 tmp_usec = frame_duration(ACK_FRAME_SIZE, rate, erp_ofdm,
 192                                         short_preamble) + ASIFSTIME_USEC;
 193                 duration_usec += fragments * tmp_usec;
 194
 195                 /* TODO: If STA-to-STA, multiply it by two. Note that
 196                  * AP may use different values for backoff. */
 197                 duration_usec *= 2; /* For demo, we have always STA-to-STA */
 198
 199                 basic = fres_contract_get_basic(c->contract);
 200                 period_usec = fosa_rel_time_to_msec(basic->period)*1000;
 201                 if (c->contract == c->new) {
 202                         c_new = c;
 203                         if (period_usec == 0) {
 204                                 goto not_schedulable;
 205                         }
 206                 }
 207                 utilization += (long long)(duration_usec * 10000) / period_usec;
 208         }
 209
 210         if (!c_new) {
 211                 *schedulable = false;
 212                 return -1;
 213         }
 214         if (utilization >= 10000 * 96/100) {
 215                 goto not_schedulable;
 216         }
 217
 218         scenario->utilization = utilization/100; /* For GUI */
 219
 220         basic = fres_contract_get_basic(c_new->contract);
 221         /*int d = c->deadline_usec;*/
 222         long int d = fosa_rel_time_to_msec(basic->period)*1000;
 223         if (d <= 0) d = 100*1000*1000;
 224         if (d < 50000) {
 225                 goto not_schedulable;
 226         };
 227
 228         *schedulable = true;
 229         fwp_sched = malloc(sizeof(*fwp_sched));
 230         fwp_sched->ac_id =
 231                         d <  100*1000 ? FWP_AC_VO :
 232                         d <  500*1000 ? FWP_AC_VI :
 233                         d < 1000*1000 ? FWP_AC_BE :
 234                         FWP_AC_BK;
 235         fres_contract_add_block(c_new->contract, FRES_BLOCK_FWP_SCHED, fwp_sched);
 236         return 0;
 237
 238 not_schedulable:
 239         *schedulable = false;
 240         return 0;
 241 }