net/batman-adv/gateway_common.c

   1 /* Copyright (C) 2009-2012 B.A.T.M.A.N. contributors:
   2  *
   3  * Marek Lindner
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of version 2 of the GNU General Public
   7  * License as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  17  * 02110-1301, USA
  18  */
  19
  20 #include "main.h"
  21 #include "gateway_common.h"
  22 #include "gateway_client.h"
  23
  24 /* calculates the gateway class from kbit */
  25 static void batadv_kbit_to_gw_bandwidth(int down, int up, long *gw_srv_class)
  26 {
  27         int mdown = 0, tdown, tup, difference;
  28         uint8_t sbit, part;
  29
  30         *gw_srv_class = 0;
  31         difference = 0x0FFFFFFF;
  32
  33         /* test all downspeeds */
  34         for (sbit = 0; sbit < 2; sbit++) {
  35                 for (part = 0; part < 16; part++) {
  36                         tdown = 32 * (sbit + 2) * (1 << part);
  37
  38                         if (abs(tdown - down) < difference) {
  39                                 *gw_srv_class = (sbit << 7) + (part << 3);
  40                                 difference = abs(tdown - down);
  41                                 mdown = tdown;
  42                         }
  43                 }
  44         }
  45
  46         /* test all upspeeds */
  47         difference = 0x0FFFFFFF;
  48
  49         for (part = 0; part < 8; part++) {
  50                 tup = ((part + 1) * (mdown)) / 8;
  51
  52                 if (abs(tup - up) < difference) {
  53                         *gw_srv_class = (*gw_srv_class & 0xF8) | part;
  54                         difference = abs(tup - up);
  55                 }
  56         }
  57 }
  58
  59 /* returns the up and downspeeds in kbit, calculated from the class */
  60 void batadv_gw_bandwidth_to_kbit(uint8_t gw_srv_class, int *down, int *up)
  61 {
  62         int sbit = (gw_srv_class & 0x80) >> 7;
  63         int dpart = (gw_srv_class & 0x78) >> 3;
  64         int upart = (gw_srv_class & 0x07);
  65
  66         if (!gw_srv_class) {
  67                 *down = 0;
  68                 *up = 0;
  69                 return;
  70         }
  71
  72         *down = 32 * (sbit + 2) * (1 << dpart);
  73         *up = ((upart + 1) * (*down)) / 8;
  74 }
  75
  76 static bool batadv_parse_gw_bandwidth(struct net_device *net_dev, char *buff,
  77                                       int *up, int *down)
  78 {
  79         int ret, multi = 1;
  80         char *slash_ptr, *tmp_ptr;
  81         long ldown, lup;
  82
  83         slash_ptr = strchr(buff, '/');
  84         if (slash_ptr)
  85                 *slash_ptr = 0;
  86
  87         if (strlen(buff) > 4) {
  88                 tmp_ptr = buff + strlen(buff) - 4;
  89
  90                 if (strnicmp(tmp_ptr, "mbit", 4) == 0)
  91                         multi = 1024;
  92
  93                 if ((strnicmp(tmp_ptr, "kbit", 4) == 0) ||
  94                     (multi > 1))
  95                         *tmp_ptr = '\0';
  96         }
  97
  98         ret = kstrtol(buff, 10, &ldown);
  99         if (ret) {
 100                 batadv_err(net_dev,
 101                            "Download speed of gateway mode invalid: %s\n",
 102                            buff);
 103                 return false;
 104         }
 105
 106         *down = ldown * multi;
 107
 108         /* we also got some upload info */
 109         if (slash_ptr) {
 110                 multi = 1;
 111
 112                 if (strlen(slash_ptr + 1) > 4) {
 113                         tmp_ptr = slash_ptr + 1 - 4 + strlen(slash_ptr + 1);
 114
 115                         if (strnicmp(tmp_ptr, "mbit", 4) == 0)
 116                                 multi = 1024;
 117
 118                         if ((strnicmp(tmp_ptr, "kbit", 4) == 0) ||
 119                             (multi > 1))
 120                                 *tmp_ptr = '\0';
 121                 }
 122
 123                 ret = kstrtol(slash_ptr + 1, 10, &lup);
 124                 if (ret) {
 125                         batadv_err(net_dev,
 126                                    "Upload speed of gateway mode invalid: %s\n",
 127                                    slash_ptr + 1);
 128                         return false;
 129                 }
 130
 131                 *up = lup * multi;
 132         }
 133
 134         return true;
 135 }
 136
 137 ssize_t batadv_gw_bandwidth_set(struct net_device *net_dev, char *buff,
 138                                 size_t count)
 139 {
 140         struct batadv_priv *bat_priv = netdev_priv(net_dev);
 141         long gw_bandwidth_tmp = 0;
 142         int up = 0, down = 0;
 143         bool ret;
 144
 145         ret = batadv_parse_gw_bandwidth(net_dev, buff, &up, &down);
 146         if (!ret)
 147                 goto end;
 148
 149         if ((!down) || (down < 256))
 150                 down = 2000;
 151
 152         if (!up)
 153                 up = down / 5;
 154
 155         batadv_kbit_to_gw_bandwidth(down, up, &gw_bandwidth_tmp);
 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         batadv_gw_bandwidth_to_kbit((uint8_t)gw_bandwidth_tmp, &down, &up);
 162
 163         if (atomic_read(&bat_priv->gw_bandwidth) == gw_bandwidth_tmp)
 164                 return count;
 165
 166         batadv_gw_deselect(bat_priv);
 167         batadv_info(net_dev,
 168                     "Changing gateway bandwidth from: '%i' to: '%ld' (propagating: %d%s/%d%s)\n",
 169                     atomic_read(&bat_priv->gw_bandwidth), gw_bandwidth_tmp,
 170                     (down > 2048 ? down / 1024 : down),
 171                     (down > 2048 ? "MBit" : "KBit"),
 172                     (up > 2048 ? up / 1024 : up),
 173                     (up > 2048 ? "MBit" : "KBit"));
 174
 175         atomic_set(&bat_priv->gw_bandwidth, gw_bandwidth_tmp);
 176
 177 end:
 178         return count;
 179 }