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