net/batman-adv/gateway_common.c

   1 /*
   2  * Copyright (C) 2009-2010 B.A.T.M.A.N. contributors:
   3  *
   4  * Marek Lindner
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of version 2 of the GNU General Public
   8  * License as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  18  * 02110-1301, USA
  19  *
  20  */
  21
  22 #include "main.h"
  23 #include "gateway_common.h"
  24 #include "gateway_client.h"
  25
  26 /* calculates the gateway class from kbit */
  27 static void kbit_to_gw_bandwidth(int down, int up, long *gw_srv_class)
  28 {
  29         int mdown = 0, tdown, tup, difference;
  30         uint8_t sbit, part;
  31
  32         *gw_srv_class = 0;
  33         difference = 0x0FFFFFFF;
  34
  35         /* test all downspeeds */
  36         for (sbit = 0; sbit < 2; sbit++) {
  37                 for (part = 0; part < 16; part++) {
  38                         tdown = 32 * (sbit + 2) * (1 << part);
  39
  40                         if (abs(tdown - down) < difference) {
  41                                 *gw_srv_class = (sbit << 7) + (part << 3);
  42                                 difference = abs(tdown - down);
  43                                 mdown = tdown;
  44                         }
  45                 }
  46         }
  47
  48         /* test all upspeeds */
  49         difference = 0x0FFFFFFF;
  50
  51         for (part = 0; part < 8; part++) {
  52                 tup = ((part + 1) * (mdown)) / 8;
  53
  54                 if (abs(tup - up) < difference) {
  55                         *gw_srv_class = (*gw_srv_class & 0xF8) | part;
  56                         difference = abs(tup - up);
  57                 }
  58         }
  59 }
  60
  61 /* returns the up and downspeeds in kbit, calculated from the class */
  62 void gw_bandwidth_to_kbit(uint8_t gw_srv_class, int *down, int *up)
  63 {
  64         char sbit = (gw_srv_class & 0x80) >> 7;
  65         char dpart = (gw_srv_class & 0x78) >> 3;
  66         char upart = (gw_srv_class & 0x07);
  67
  68         if (!gw_srv_class) {
  69                 *down = 0;
  70                 *up = 0;
  71                 return;
  72         }
  73
  74         *down = 32 * (sbit + 2) * (1 << dpart);
  75         *up = ((upart + 1) * (*down)) / 8;
  76 }
  77
  78 static bool parse_gw_bandwidth(struct net_device *net_dev, char *buff,
  79                                long *up, long *down)
  80 {
  81         int ret, multi = 1;
  82         char *slash_ptr, *tmp_ptr;
  83
  84         slash_ptr = strchr(buff, '/');
  85         if (slash_ptr)
  86                 *slash_ptr = 0;
  87
  88         if (strlen(buff) > 4) {
  89                 tmp_ptr = buff + strlen(buff) - 4;
  90
  91                 if (strnicmp(tmp_ptr, "mbit", 4) == 0)
  92                         multi = 1024;
  93
  94                 if ((strnicmp(tmp_ptr, "kbit", 4) == 0) ||
  95                         (multi > 1))
  96                         *tmp_ptr = '\0';
  97         }
  98
  99         ret = strict_strtoul(buff, 10, down);
 100         if (ret) {
 101                 bat_err(net_dev,
 102                         "Download speed of gateway mode invalid: %s\n",
 103                         buff);
 104                 return false;
 105         }
 106
 107         *down *= multi;
 108
 109         /* we also got some upload info */
 110         if (slash_ptr) {
 111                 multi = 1;
 112
 113                 if (strlen(slash_ptr + 1) > 4) {
 114                         tmp_ptr = slash_ptr + 1 - 4 + strlen(slash_ptr + 1);
 115
 116                         if (strnicmp(tmp_ptr, "mbit", 4) == 0)
 117                                 multi = 1024;
 118
 119                         if ((strnicmp(tmp_ptr, "kbit", 4) == 0) ||
 120                                 (multi > 1))
 121                                 *tmp_ptr = '\0';
 122                 }
 123
 124                 ret = strict_strtoul(slash_ptr + 1, 10, up);
 125                 if (ret) {
 126                         bat_err(net_dev,
 127                                 "Upload speed of gateway mode invalid: "
 128                                 "%s\n", slash_ptr + 1);
 129                         return false;
 130                 }
 131
 132                 *up *= multi;
 133         }
 134
 135         return true;
 136 }
 137
 138 ssize_t gw_bandwidth_set(struct net_device *net_dev, char *buff, size_t count)
 139 {
 140         struct bat_priv *bat_priv = netdev_priv(net_dev);
 141         long gw_bandwidth_tmp = 0, up = 0, down = 0;
 142         bool ret;
 143
 144         ret = parse_gw_bandwidth(net_dev, buff, &up, &down);
 145         if (!ret)
 146                 goto end;
 147
 148         if ((!down) || (down < 256))
 149                 down = 2000;
 150
 151         if (!up)
 152                 up = down / 5;
 153
 154         kbit_to_gw_bandwidth(down, up, &gw_bandwidth_tmp);
 155
 156         /**
 157          * the gw bandwidth we guessed above might not match the given
 158          * speeds, hence we need to calculate it back to show the number
 159          * that is going to be propagated
 160          **/
 161         gw_bandwidth_to_kbit((uint8_t)gw_bandwidth_tmp,
 162                              (int *)&down, (int *)&up);
 163
 164         gw_deselect(bat_priv);
 165         bat_info(net_dev, "Changing gateway bandwidth from: '%i' to: '%ld' "
 166                  "(propagating: %ld%s/%ld%s)\n",
 167                  atomic_read(&bat_priv->gw_bandwidth), gw_bandwidth_tmp,
 168                  (down > 2048 ? down / 1024 : down),
 169                  (down > 2048 ? "MBit" : "KBit"),
 170                  (up > 2048 ? up / 1024 : up),
 171                  (up > 2048 ? "MBit" : "KBit"));
 172
 173         atomic_set(&bat_priv->gw_bandwidth, gw_bandwidth_tmp);
 174
 175 end:
 176         return count;
 177 }