net/batman-adv/gateway_common.c

   1 /* Copyright (C) 2009-2016  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, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include "gateway_common.h"
  19 #include "main.h"
  20
  21 #include <linux/atomic.h>
  22 #include <linux/byteorder/generic.h>
  23 #include <linux/errno.h>
  24 #include <linux/kernel.h>
  25 #include <linux/math64.h>
  26 #include <linux/netdevice.h>
  27 #include <linux/stddef.h>
  28 #include <linux/string.h>
  29
  30 #include "gateway_client.h"
  31 #include "log.h"
  32 #include "packet.h"
  33 #include "tvlv.h"
  34
  35 /**
  36  * batadv_parse_throughput - parse supplied string buffer to extract throughput
  37  *  information
  38  * @net_dev: the soft interface net device
  39  * @buff: string buffer to parse
  40  * @description: text shown when throughput string cannot be parsed
  41  * @throughput: pointer holding the returned throughput information
  42  *
  43  * Return: false on parse error and true otherwise.
  44  */
  45 bool batadv_parse_throughput(struct net_device *net_dev, char *buff,
  46                              const char *description, u32 *throughput)
  47 {
  48         enum batadv_bandwidth_units bw_unit_type = BATADV_BW_UNIT_KBIT;
  49         u64 lthroughput;
  50         char *tmp_ptr;
  51         int ret;
  52
  53         if (strlen(buff) > 4) {
  54                 tmp_ptr = buff + strlen(buff) - 4;
  55
  56                 if (strncasecmp(tmp_ptr, "mbit", 4) == 0)
  57                         bw_unit_type = BATADV_BW_UNIT_MBIT;
  58
  59                 if ((strncasecmp(tmp_ptr, "kbit", 4) == 0) ||
  60                     (bw_unit_type == BATADV_BW_UNIT_MBIT))
  61                         *tmp_ptr = '\0';
  62         }
  63
  64         ret = kstrtou64(buff, 10, &lthroughput);
  65         if (ret) {
  66                 batadv_err(net_dev,
  67                            "Invalid throughput speed for %s: %s\n",
  68                            description, buff);
  69                 return false;
  70         }
  71
  72         switch (bw_unit_type) {
  73         case BATADV_BW_UNIT_MBIT:
  74                 /* prevent overflow */
  75                 if (U64_MAX / 10 < lthroughput) {
  76                         batadv_err(net_dev,
  77                                    "Throughput speed for %s too large: %s\n",
  78                                    description, buff);
  79                         return false;
  80                 }
  81
  82                 lthroughput *= 10;
  83                 break;
  84         case BATADV_BW_UNIT_KBIT:
  85         default:
  86                 lthroughput = div_u64(lthroughput, 100);
  87                 break;
  88         }
  89
  90         if (lthroughput > U32_MAX) {
  91                 batadv_err(net_dev,
  92                            "Throughput speed for %s too large: %s\n",
  93                            description, buff);
  94                 return false;
  95         }
  96
  97         *throughput = lthroughput;
  98
  99         return true;
 100 }
 101
 102 /**
 103  * batadv_parse_gw_bandwidth - parse supplied string buffer to extract download
 104  *  and upload bandwidth information
 105  * @net_dev: the soft interface net device
 106  * @buff: string buffer to parse
 107  * @down: pointer holding the returned download bandwidth information
 108  * @up: pointer holding the returned upload bandwidth information
 109  *
 110  * Return: false on parse error and true otherwise.
 111  */
 112 static bool batadv_parse_gw_bandwidth(struct net_device *net_dev, char *buff,
 113                                       u32 *down, u32 *up)
 114 {
 115         char *slash_ptr;
 116         bool ret;
 117
 118         slash_ptr = strchr(buff, '/');
 119         if (slash_ptr)
 120                 *slash_ptr = 0;
 121
 122         ret = batadv_parse_throughput(net_dev, buff, "download gateway speed",
 123                                       down);
 124         if (!ret)
 125                 return false;
 126
 127         /* we also got some upload info */
 128         if (slash_ptr) {
 129                 ret = batadv_parse_throughput(net_dev, slash_ptr + 1,
 130                                               "upload gateway speed", up);
 131                 if (!ret)
 132                         return false;
 133         }
 134
 135         return true;
 136 }
 137
 138 /**
 139  * batadv_gw_tvlv_container_update - update the gw tvlv container after gateway
 140  *  setting change
 141  * @bat_priv: the bat priv with all the soft interface information
 142  */
 143 void batadv_gw_tvlv_container_update(struct batadv_priv *bat_priv)
 144 {
 145         struct batadv_tvlv_gateway_data gw;
 146         u32 down, up;
 147         char gw_mode;
 148
 149         gw_mode = atomic_read(&bat_priv->gw.mode);
 150
 151         switch (gw_mode) {
 152         case BATADV_GW_MODE_OFF:
 153         case BATADV_GW_MODE_CLIENT:
 154                 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_GW, 1);
 155                 break;
 156         case BATADV_GW_MODE_SERVER:
 157                 down = atomic_read(&bat_priv->gw.bandwidth_down);
 158                 up = atomic_read(&bat_priv->gw.bandwidth_up);
 159                 gw.bandwidth_down = htonl(down);
 160                 gw.bandwidth_up = htonl(up);
 161                 batadv_tvlv_container_register(bat_priv, BATADV_TVLV_GW, 1,
 162                                                &gw, sizeof(gw));
 163                 break;
 164         }
 165 }
 166
 167 ssize_t batadv_gw_bandwidth_set(struct net_device *net_dev, char *buff,
 168                                 size_t count)
 169 {
 170         struct batadv_priv *bat_priv = netdev_priv(net_dev);
 171         u32 down_curr;
 172         u32 up_curr;
 173         u32 down_new = 0;
 174         u32 up_new = 0;
 175         bool ret;
 176
 177         down_curr = (unsigned int)atomic_read(&bat_priv->gw.bandwidth_down);
 178         up_curr = (unsigned int)atomic_read(&bat_priv->gw.bandwidth_up);
 179
 180         ret = batadv_parse_gw_bandwidth(net_dev, buff, &down_new, &up_new);
 181         if (!ret)
 182                 return -EINVAL;
 183
 184         if (!down_new)
 185                 down_new = 1;
 186
 187         if (!up_new)
 188                 up_new = down_new / 5;
 189
 190         if (!up_new)
 191                 up_new = 1;
 192
 193         if ((down_curr == down_new) && (up_curr == up_new))
 194                 return count;
 195
 196         batadv_gw_reselect(bat_priv);
 197         batadv_info(net_dev,
 198                     "Changing gateway bandwidth from: '%u.%u/%u.%u MBit' to: '%u.%u/%u.%u MBit'\n",
 199                     down_curr / 10, down_curr % 10, up_curr / 10, up_curr % 10,
 200                     down_new / 10, down_new % 10, up_new / 10, up_new % 10);
 201
 202         atomic_set(&bat_priv->gw.bandwidth_down, down_new);
 203         atomic_set(&bat_priv->gw.bandwidth_up, up_new);
 204         batadv_gw_tvlv_container_update(bat_priv);
 205
 206         return count;
 207 }
 208
 209 /**
 210  * batadv_gw_tvlv_ogm_handler_v1 - process incoming gateway tvlv container
 211  * @bat_priv: the bat priv with all the soft interface information
 212  * @orig: the orig_node of the ogm
 213  * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
 214  * @tvlv_value: tvlv buffer containing the gateway data
 215  * @tvlv_value_len: tvlv buffer length
 216  */
 217 static void batadv_gw_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
 218                                           struct batadv_orig_node *orig,
 219                                           u8 flags,
 220                                           void *tvlv_value, u16 tvlv_value_len)
 221 {
 222         struct batadv_tvlv_gateway_data gateway, *gateway_ptr;
 223
 224         /* only fetch the tvlv value if the handler wasn't called via the
 225          * CIFNOTFND flag and if there is data to fetch
 226          */
 227         if ((flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND) ||
 228             (tvlv_value_len < sizeof(gateway))) {
 229                 gateway.bandwidth_down = 0;
 230                 gateway.bandwidth_up = 0;
 231         } else {
 232                 gateway_ptr = tvlv_value;
 233                 gateway.bandwidth_down = gateway_ptr->bandwidth_down;
 234                 gateway.bandwidth_up = gateway_ptr->bandwidth_up;
 235                 if ((gateway.bandwidth_down == 0) ||
 236                     (gateway.bandwidth_up == 0)) {
 237                         gateway.bandwidth_down = 0;
 238                         gateway.bandwidth_up = 0;
 239                 }
 240         }
 241
 242         batadv_gw_node_update(bat_priv, orig, &gateway);
 243
 244         /* restart gateway selection if fast or late switching was enabled */
 245         if ((gateway.bandwidth_down != 0) &&
 246             (atomic_read(&bat_priv->gw.mode) == BATADV_GW_MODE_CLIENT) &&
 247             (atomic_read(&bat_priv->gw.sel_class) > 2))
 248                 batadv_gw_check_election(bat_priv, orig);
 249 }
 250
 251 /**
 252  * batadv_gw_init - initialise the gateway handling internals
 253  * @bat_priv: the bat priv with all the soft interface information
 254  */
 255 void batadv_gw_init(struct batadv_priv *bat_priv)
 256 {
 257         batadv_tvlv_handler_register(bat_priv, batadv_gw_tvlv_ogm_handler_v1,
 258                                      NULL, BATADV_TVLV_GW, 1,
 259                                      BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
 260 }
 261
 262 /**
 263  * batadv_gw_free - free the gateway handling internals
 264  * @bat_priv: the bat priv with all the soft interface information
 265  */
 266 void batadv_gw_free(struct batadv_priv *bat_priv)
 267 {
 268         batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_GW, 1);
 269         batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_GW, 1);
 270 }