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 #include <ul_log.h>
  51 #include <ul_logreg.h>
  52
  53 UL_LOG_CUST(ulogd_fwp_admctrl);
  54 ul_log_domain_t ulogd_fwp_admctrl = {UL_LOGL_MSG, "fwp_admctrl"};
  55 UL_LOGREG_SINGLE_DOMAIN_INIT_FUNCTION(fwp_admctrl_logreg_domains, ulogd_fwp_admctrl);
  56
  57 /* TODO: Find out the real value and determine what influences it (MTU
  58  *       of the interface minus header sizes?).  */
  59 #define MTU 1472
  60 #define UDP_HEADER_SIZE 8
  61 #define IP_HEADER_SIZE 20
  62 #define LLC_HEADER_SIZE 2       /* ??? */
  63 #define MAC_HEADER_SIZE 26      /* With QoS field added */
  64 #define MAC_FCS_SIZE 4
  65
  66 #define RTS_FRAME_SIZE 20
  67 #define CTS_FRAME_SIZE 14
  68 #define ACK_FRAME_SIZE 14
  69
  70 #define ASLOTTIME_USEC 20       /* 802.11g-2003 p. 46 */
  71 #define ASIFSTIME_USEC 10
  72 #define ADIFSTIME_USEC (ASIFSTIME_USEC + 2*ASLOTTIME_USEC)
  73 #define AAIFSTIME_USEC(n) (ASIFSTIME_USEC + (n)*ASLOTTIME_USEC)
  74
  75 /* Default values from 802.11e */
  76 const int aifsn[FWP_AC_NUM] = { 2, 2, 3, 7 };
  77 const int cwmin[FWP_AC_NUM] = { 3, 7, 15, 15 };
  78
  79 /* Experimental konstants - weight of backoff */
  80 const int pisvejc[FWP_AC_NUM] = { 6, 5, 2, 2 };
  81
  82 int fwp_reserved_utilization;
  83
  84 /**
  85  * Calucaltes frame duration in microseconds. If the real duration is
  86  * represented by a fractional number, the value is rounded up.
  87  *
  88  * @param length Number of bytes in PSDU.
  89  * @param rate_bps Transmit rate of PSDU. The rate should correspond
  90  *            to other parameters accoring to 19.3.2 (802.11g)
  91  * @param erp_ofdm Whether Extended Rate PHY (part of 802.11g) and ERP-OFDM
  92  *            modulation is used.
  93  * @param short_preamble Whether short preamble (HR/DSSS/short) is
  94  *            used (802.11b)
  95  *
  96  * @return The number of microseconds or a negative number in case of error.
  97  */
  98 static int frame_duration(uint16_t length, int rate_bps, bool erp_ofdm, bool short_preamble)
  99 {
 100         uint32_t duration_usec = 0;
 101
 102         if (!erp_ofdm) {
 103                 duration_usec = ((int64_t)(length) * 8 * SEC_TO_USEC / rate_bps);
 104                 if (short_preamble) {
 105                         /* For HR/DSSS/short (2, 5.5 and 11 Mbit,
 106                          * 802.11b-1999), also for DSSS-OFDM rates and
 107                          * ERP-PBCC rates.
 108                          * Preamble sent at 1 MBit, header at 2 Mbit */
 109                         duration_usec += 72/*bits*/+48/*bits*//2;
 110                 } else {
 111                         /* For DSSS PHY (1 and 2 Mbit rates,
 112                          * 802.11-1999) and for DSS-OFDM and ERP-PBCC
 113                          * rates. Always sent at 1 MBit */
 114                         duration_usec += 144/*bits*/+48/*bits*/;
 115                 }
 116         } else {
 117 #define MBIT_TO_INDEX(rate_Mbps)  ((rate_Mbps)/3 - 2)
 118                 const int N_dbps[] = {
 119                         [MBIT_TO_INDEX(6)] = 24,
 120                         [MBIT_TO_INDEX(9)] = 36,
 121                         [MBIT_TO_INDEX(12)] = 48,
 122                         [MBIT_TO_INDEX(18)] = 72,
 123                         [MBIT_TO_INDEX(24)] = 96,
 124                         [MBIT_TO_INDEX(36)] = 144,
 125                         [MBIT_TO_INDEX(48)] = 192,
 126                         [MBIT_TO_INDEX(54)] = 216
 127                 };
 128                 int rate_idx = MBIT_TO_INDEX(rate_bps/1000/1000);
 129 #undef MBIT_TO_INDEX
 130                 if (rate_idx < 0 ||
 131                     rate_idx >= sizeof(N_dbps)/sizeof(*N_dbps) ||
 132                     N_dbps[rate_idx] == 0)
 133                         return -1;
 134
 135                 duration_usec += 16 + 4; /* Preamble, SIGNAL */
 136                 int bits =
 137                         16 +        /* SERVICE */
 138                         length * 8 +
 139                         6;          /* tail bits */
 140                 int Nsym = (bits + N_dbps[rate_idx] - 1)/N_dbps[rate_idx];
 141
 142                 duration_usec += Nsym * 4;
 143
 144                 duration_usec += 6; /* signal extension */
 145         }
 146         return duration_usec;
 147 }
 148
 149 int fwp_admctrl_utilization(struct fres_sa_scenario *scenario, void *priv,
 150                                 bool *schedulable)
 151 {
 152         int utilization = 0;
 153
 154         const int rate = 54*1000*1000;
 155         const bool erp_ofdm = true;
 156         const bool short_preamble = true;
 157         struct fres_sa_contract *c;
 158         long int period_usec;
 159         fres_block_fwp_sched *fwp_sched;
 160
 161         size_t bytes;
 162         long int duration_usec, tmp_usec;
 163         int fragments;
 164         int ac = FWP_AC_VO;
 165
 166         fres_sa_scenario_for_each_no_cancel_contract(scenario, c) {
 167                 fres_block_basic *basic;
 168                 char id[40];
 169                 fres_contract_id_to_string(id, &c->contract->id, sizeof(id));
 170                 basic = fres_contract_get_basic(c->contract);
 171
 172                 frsh_network_budget_to_bytes(FRSH_NETPF_FWP,&basic->budget,&bytes);
 173                 ul_logmsg("processing: id=%s, period=%ld ms, budget=%lu bytes\n",
 174                        id,
 175                        fosa_rel_time_to_msec(basic->period),
 176                        (long unsigned int)bytes);
 177
 178                 /* Calculate protocol overhead */
 179                 fragments = (bytes + MTU - 1) / MTU;
 180
 181                 if (fragments == 0)
 182                         continue;
 183
 184                 const int data_overhead = UDP_HEADER_SIZE + IP_HEADER_SIZE +
 185                         LLC_HEADER_SIZE + MAC_FCS_SIZE;
 186
 187                 duration_usec = frame_duration(data_overhead + bytes%MTU, rate,
 188                                                 erp_ofdm, short_preamble);
 189                 tmp_usec = frame_duration(data_overhead + MTU, rate, erp_ofdm,
 190                                                 short_preamble);
 191                 duration_usec += tmp_usec*(fragments-1);
 192                 /* Add average backoff - assume there is no collision */
 193                 tmp_usec = ASLOTTIME_USEC*fragments*pisvejc[ac];
 194                 duration_usec += (aifsn[ac] + cwmin[ac]/2)*tmp_usec;
 195                 /* We use ACK and ignore burst */
 196                 tmp_usec = frame_duration(ACK_FRAME_SIZE, rate, erp_ofdm,
 197                                         short_preamble) + ASIFSTIME_USEC;
 198                 duration_usec += fragments * tmp_usec;
 199                 //printf("duration: %ld ms\n", duration_usec/1000);
 200
 201                 /* TODO: If STA-to-STA, multiply it by two. Note that
 202                  * AP may use different values for backoff. */
 203                 //duration_usec *= 2; /* For demo, we have always STA-to-STA */
 204
 205                 basic = fres_contract_get_basic(c->contract);
 206                 period_usec = basic ? fosa_rel_time_to_msec(basic->period)*1000 : 0;
 207
 208                 if (c->contract == c->new) {
 209                         if (period_usec == 0) {
 210                                 ul_logmsg("Period is zero!\n");
 211                                 goto not_schedulable;
 212                         }
 213
 214                         frsh_rel_time_t deadline;
 215                         long int d;
 216                         if (fres_contract_get_deadline(&c->contract, &deadline)) {
 217                                 d = fosa_rel_time_to_msec(deadline)*1000;
 218                         } else {
 219                                 d = 100/*sec*/*1000*1000;
 220                         }
 221                         if (d < 30/*msec*/*1000) {
 222                                 ul_logmsg("Deadline shorter than 30 ms!\n");
 223                                 goto not_schedulable;
 224                         };
 225
 226                         fwp_sched = malloc(sizeof(*fwp_sched));
 227                         fwp_sched->ac_id =
 228                                 d <  100*1000 ? FWP_AC_VO :
 229                                 d <  500*1000 ? FWP_AC_VI :
 230                                 d < 1000*1000 ? FWP_AC_BE :
 231                                 FWP_AC_BK;
 232                         fres_contract_add_block(c->contract, FRES_BLOCK_FWP_SCHED, fwp_sched);
 233                 }
 234
 235                 utilization += (long long)(duration_usec * 10000) / period_usec;
 236         }
 237
 238         if (utilization >= 10000 * 96/100) {
 239                 goto not_schedulable;
 240         }
 241         scenario->utilization = utilization/100; /* For GUI */
 242
 243         ul_logmsg("accepted\n");
 244         *schedulable = true;
 245         return 0;
 246
 247 not_schedulable:
 248         ul_logmsg("rejected\n");
 249         *schedulable = false;
 250         return 0;
 251 }