net/batman-adv/gateway_common.c

   1 /* Copyright (C) 2009-2015 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/errno.h>
  23 #include <linux/byteorder/generic.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 "packet.h"
  32
  33 /**
  34  * batadv_parse_throughput - parse supplied string buffer to extract throughput
  35  *  information
  36  * @net_dev: the soft interface net device
  37  * @buff: string buffer to parse
  38  * @description: text shown when throughput string cannot be parsed
  39  * @throughput: pointer holding the returned throughput information
  40  *
  41  * Returns false on parse error and true otherwise.
  42  */
  43 static bool batadv_parse_throughput(struct net_device *net_dev, char *buff,
  44                                     const char *description, u32 *throughput)
  45 {
  46         enum batadv_bandwidth_units bw_unit_type = BATADV_BW_UNIT_KBIT;
  47         u64 lthroughput;
  48         char *tmp_ptr;
  49         int ret;
  50
  51         if (strlen(buff) > 4) {
  52                 tmp_ptr = buff + strlen(buff) - 4;
  53
  54                 if (strncasecmp(tmp_ptr, "mbit", 4) == 0)
  55                         bw_unit_type = BATADV_BW_UNIT_MBIT;
  56
  57                 if ((strncasecmp(tmp_ptr, "kbit", 4) == 0) ||
  58                     (bw_unit_type == BATADV_BW_UNIT_MBIT))
  59                         *tmp_ptr = '\0';
  60         }
  61
  62         ret = kstrtou64(buff, 10, &lthroughput);
  63         if (ret) {
  64                 batadv_err(net_dev,
  65                            "Invalid throughput speed for %s: %s\n",
  66                            description, buff);
  67                 return false;
  68         }
  69
  70         switch (bw_unit_type) {
  71         case BATADV_BW_UNIT_MBIT:
  72                 /* prevent overflow */
  73                 if (U64_MAX / 10 < lthroughput) {
  74                         batadv_err(net_dev,
  75                                    "Throughput speed for %s too large: %s\n",
  76                                    description, buff);
  77                         return false;
  78                 }
  79
  80                 lthroughput *= 10;
  81                 break;
  82         case BATADV_BW_UNIT_KBIT:
  83         default:
  84                 lthroughput = div_u64(lthroughput, 100);
  85                 break;
  86         }
  87
  88         if (lthroughput > U32_MAX) {
  89                 batadv_err(net_dev,
  90                            "Throughput speed for %s too large: %s\n",
  91                            description, buff);
  92                 return false;
  93         }
  94
  95         *throughput = lthroughput;
  96
  97         return true;
  98 }
  99
 100 /**
 101  * batadv_parse_gw_bandwidth - parse supplied string buffer to extract download
 102  *  and upload bandwidth information
 103  * @net_dev: the soft interface net device
 104  * @buff: string buffer to parse
 105  * @down: pointer holding the returned download bandwidth information
 106  * @up: pointer holding the returned upload bandwidth information
 107  *
 108  * Return: false on parse error and true otherwise.
 109  */
 110 static bool batadv_parse_gw_bandwidth(struct net_device *net_dev, char *buff,
 111                                       u32 *down, u32 *up)
 112 {
 113         char *slash_ptr;
 114         bool ret;
 115
 116         slash_ptr = strchr(buff, '/');
 117         if (slash_ptr)
 118                 *slash_ptr = 0;
 119
 120         ret = batadv_parse_throughput(net_dev, buff, "download gateway speed",
 121                                       down);
 122         if (!ret)
 123                 return false;
 124
 125         /* we also got some upload info */
 126         if (slash_ptr) {
 127                 ret = batadv_parse_throughput(net_dev, slash_ptr + 1,
 128                                               "upload gateway speed", up);
 129                 if (!ret)
 130                         return false;
 131         }
 132
 133         return true;
 134 }
 135
 136 /**
 137  * batadv_gw_tvlv_container_update - update the gw tvlv container after gateway
 138  *  setting change
 139  * @bat_priv: the bat priv with all the soft interface information
 140  */
 141 void batadv_gw_tvlv_container_update(struct batadv_priv *bat_priv)
 142 {
 143         struct batadv_tvlv_gateway_data gw;
 144         u32 down, up;
 145         char gw_mode;
 146
 147         gw_mode = atomic_read(&bat_priv->gw_mode);
 148
 149         switch (gw_mode) {
 150         case BATADV_GW_MODE_OFF:
 151         case BATADV_GW_MODE_CLIENT:
 152                 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_GW, 1);
 153                 break;
 154         case BATADV_GW_MODE_SERVER:
 155                 down = atomic_read(&bat_priv->gw.bandwidth_down);
 156                 up = atomic_read(&bat_priv->gw.bandwidth_up);
 157                 gw.bandwidth_down = htonl(down);
 158                 gw.bandwidth_up = htonl(up);
 159                 batadv_tvlv_container_register(bat_priv, BATADV_TVLV_GW, 1,
 160                                                &gw, sizeof(gw));
 161                 break;
 162         }
 163 }
 164
 165 ssize_t batadv_gw_bandwidth_set(struct net_device *net_dev, char *buff,
 166                                 size_t count)
 167 {
 168         struct batadv_priv *bat_priv = netdev_priv(net_dev);
 169         u32 down_curr;
 170         u32 up_curr;
 171         u32 down_new = 0;
 172         u32 up_new = 0;
 173         bool ret;
 174
 175         down_curr = (unsigned int)atomic_read(&bat_priv->gw.bandwidth_down);
 176         up_curr = (unsigned int)atomic_read(&bat_priv->gw.bandwidth_up);
 177
 178         ret = batadv_parse_gw_bandwidth(net_dev, buff, &down_new, &up_new);
 179         if (!ret)
 180                 return -EINVAL;
 181
 182         if (!down_new)
 183                 down_new = 1;
 184
 185         if (!up_new)
 186                 up_new = down_new / 5;
 187
 188         if (!up_new)
 189                 up_new = 1;
 190
 191         if ((down_curr == down_new) && (up_curr == up_new))
 192                 return count;
 193
 194         batadv_gw_reselect(bat_priv);
 195         batadv_info(net_dev,
 196                     "Changing gateway bandwidth from: '%u.%u/%u.%u MBit' to: '%u.%u/%u.%u MBit'\n",
 197                     down_curr / 10, down_curr % 10, up_curr / 10, up_curr % 10,
 198                     down_new / 10, down_new % 10, up_new / 10, up_new % 10);
 199
 200         atomic_set(&bat_priv->gw.bandwidth_down, down_new);
 201         atomic_set(&bat_priv->gw.bandwidth_up, up_new);
 202         batadv_gw_tvlv_container_update(bat_priv);
 203
 204         return count;
 205 }
 206
 207 /**
 208  * batadv_gw_tvlv_ogm_handler_v1 - process incoming gateway tvlv container
 209  * @bat_priv: the bat priv with all the soft interface information
 210  * @orig: the orig_node of the ogm
 211  * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
 212  * @tvlv_value: tvlv buffer containing the gateway data
 213  * @tvlv_value_len: tvlv buffer length
 214  */
 215 static void batadv_gw_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
 216                                           struct batadv_orig_node *orig,
 217                                           u8 flags,
 218                                           void *tvlv_value, u16 tvlv_value_len)
 219 {
 220         struct batadv_tvlv_gateway_data gateway, *gateway_ptr;
 221
 222         /* only fetch the tvlv value if the handler wasn't called via the
 223          * CIFNOTFND flag and if there is data to fetch
 224          */
 225         if ((flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND) ||
 226             (tvlv_value_len < sizeof(gateway))) {
 227                 gateway.bandwidth_down = 0;
 228                 gateway.bandwidth_up = 0;
 229         } else {
 230                 gateway_ptr = tvlv_value;
 231                 gateway.bandwidth_down = gateway_ptr->bandwidth_down;
 232                 gateway.bandwidth_up = gateway_ptr->bandwidth_up;
 233                 if ((gateway.bandwidth_down == 0) ||
 234                     (gateway.bandwidth_up == 0)) {
 235                         gateway.bandwidth_down = 0;
 236                         gateway.bandwidth_up = 0;
 237                 }
 238         }
 239
 240         batadv_gw_node_update(bat_priv, orig, &gateway);
 241
 242         /* restart gateway selection if fast or late switching was enabled */
 243         if ((gateway.bandwidth_down != 0) &&
 244             (atomic_read(&bat_priv->gw_mode) == BATADV_GW_MODE_CLIENT) &&
 245             (atomic_read(&bat_priv->gw_sel_class) > 2))
 246                 batadv_gw_check_election(bat_priv, orig);
 247 }
 248
 249 /**
 250  * batadv_gw_init - initialise the gateway handling internals
 251  * @bat_priv: the bat priv with all the soft interface information
 252  */
 253 void batadv_gw_init(struct batadv_priv *bat_priv)
 254 {
 255         batadv_tvlv_handler_register(bat_priv, batadv_gw_tvlv_ogm_handler_v1,
 256                                      NULL, BATADV_TVLV_GW, 1,
 257                                      BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
 258 }
 259
 260 /**
 261  * batadv_gw_free - free the gateway handling internals
 262  * @bat_priv: the bat priv with all the soft interface information
 263  */
 264 void batadv_gw_free(struct batadv_priv *bat_priv)
 265 {
 266         batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_GW, 1);
 267         batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_GW, 1);
 268 }