net/batman-adv/gateway_common.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (C) 2009-2017  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, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include "gateway_common.h"
  20 #include "main.h"
  21
  22 #include <linux/atomic.h>
  23 #include <linux/byteorder/generic.h>
  24 #include <linux/errno.h>
  25 #include <linux/kernel.h>
  26 #include <linux/math64.h>
  27 #include <linux/netdevice.h>
  28 #include <linux/stddef.h>
  29 #include <linux/string.h>
  30 #include <uapi/linux/batadv_packet.h>
  31
  32 #include "gateway_client.h"
  33 #include "log.h"
  34 #include "tvlv.h"
  35
  36 /**
  37  * batadv_parse_throughput() - parse supplied string buffer to extract
  38  *  throughput information
  39  * @net_dev: the soft interface net device
  40  * @buff: string buffer to parse
  41  * @description: text shown when throughput string cannot be parsed
  42  * @throughput: pointer holding the returned throughput information
  43  *
  44  * Return: false on parse error and true otherwise.
  45  */
  46 bool batadv_parse_throughput(struct net_device *net_dev, char *buff,
  47                              const char *description, u32 *throughput)
  48 {
  49         enum batadv_bandwidth_units bw_unit_type = BATADV_BW_UNIT_KBIT;
  50         u64 lthroughput;
  51         char *tmp_ptr;
  52         int ret;
  53
  54         if (strlen(buff) > 4) {
  55                 tmp_ptr = buff + strlen(buff) - 4;
  56
  57                 if (strncasecmp(tmp_ptr, "mbit", 4) == 0)
  58                         bw_unit_type = BATADV_BW_UNIT_MBIT;
  59
  60                 if (strncasecmp(tmp_ptr, "kbit", 4) == 0 ||
  61                     bw_unit_type == BATADV_BW_UNIT_MBIT)
  62                         *tmp_ptr = '\0';
  63         }
  64
  65         ret = kstrtou64(buff, 10, &lthroughput);
  66         if (ret) {
  67                 batadv_err(net_dev,
  68                            "Invalid throughput speed for %s: %s\n",
  69                            description, buff);
  70                 return false;
  71         }
  72
  73         switch (bw_unit_type) {
  74         case BATADV_BW_UNIT_MBIT:
  75                 /* prevent overflow */
  76                 if (U64_MAX / 10 < lthroughput) {
  77                         batadv_err(net_dev,
  78                                    "Throughput speed for %s too large: %s\n",
  79                                    description, buff);
  80                         return false;
  81                 }
  82
  83                 lthroughput *= 10;
  84                 break;
  85         case BATADV_BW_UNIT_KBIT:
  86         default:
  87                 lthroughput = div_u64(lthroughput, 100);
  88                 break;
  89         }
  90
  91         if (lthroughput > U32_MAX) {
  92                 batadv_err(net_dev,
  93                            "Throughput speed for %s too large: %s\n",
  94                            description, buff);
  95                 return false;
  96         }
  97
  98         *throughput = lthroughput;
  99
 100         return true;
 101 }
 102
 103 /**
 104  * batadv_parse_gw_bandwidth() - parse supplied string buffer to extract
 105  *  download and upload bandwidth information
 106  * @net_dev: the soft interface net device
 107  * @buff: string buffer to parse
 108  * @down: pointer holding the returned download bandwidth information
 109  * @up: pointer holding the returned upload bandwidth information
 110  *
 111  * Return: false on parse error and true otherwise.
 112  */
 113 static bool batadv_parse_gw_bandwidth(struct net_device *net_dev, char *buff,
 114                                       u32 *down, u32 *up)
 115 {
 116         char *slash_ptr;
 117         bool ret;
 118
 119         slash_ptr = strchr(buff, '/');
 120         if (slash_ptr)
 121                 *slash_ptr = 0;
 122
 123         ret = batadv_parse_throughput(net_dev, buff, "download gateway speed",
 124                                       down);
 125         if (!ret)
 126                 return false;
 127
 128         /* we also got some upload info */
 129         if (slash_ptr) {
 130                 ret = batadv_parse_throughput(net_dev, slash_ptr + 1,
 131                                               "upload gateway speed", up);
 132                 if (!ret)
 133                         return false;
 134         }
 135
 136         return true;
 137 }
 138
 139 /**
 140  * batadv_gw_tvlv_container_update() - update the gw tvlv container after
 141  *  gateway setting change
 142  * @bat_priv: the bat priv with all the soft interface information
 143  */
 144 void batadv_gw_tvlv_container_update(struct batadv_priv *bat_priv)
 145 {
 146         struct batadv_tvlv_gateway_data gw;
 147         u32 down, up;
 148         char gw_mode;
 149
 150         gw_mode = atomic_read(&bat_priv->gw.mode);
 151
 152         switch (gw_mode) {
 153         case BATADV_GW_MODE_OFF:
 154         case BATADV_GW_MODE_CLIENT:
 155                 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_GW, 1);
 156                 break;
 157         case BATADV_GW_MODE_SERVER:
 158                 down = atomic_read(&bat_priv->gw.bandwidth_down);
 159                 up = atomic_read(&bat_priv->gw.bandwidth_up);
 160                 gw.bandwidth_down = htonl(down);
 161                 gw.bandwidth_up = htonl(up);
 162                 batadv_tvlv_container_register(bat_priv, BATADV_TVLV_GW, 1,
 163                                                &gw, sizeof(gw));
 164                 break;
 165         }
 166 }
 167
 168 /**
 169  * batadv_gw_bandwidth_set() - Parse and set download/upload gateway bandwidth
 170  *  from supplied string buffer
 171  * @net_dev: netdev struct of the soft interface
 172  * @buff: the buffer containing the user data
 173  * @count: number of bytes in the buffer
 174  *
 175  * Return: 'count' on success or a negative error code in case of failure
 176  */
 177 ssize_t batadv_gw_bandwidth_set(struct net_device *net_dev, char *buff,
 178                                 size_t count)
 179 {
 180         struct batadv_priv *bat_priv = netdev_priv(net_dev);
 181         u32 down_curr;
 182         u32 up_curr;
 183         u32 down_new = 0;
 184         u32 up_new = 0;
 185         bool ret;
 186
 187         down_curr = (unsigned int)atomic_read(&bat_priv->gw.bandwidth_down);
 188         up_curr = (unsigned int)atomic_read(&bat_priv->gw.bandwidth_up);
 189
 190         ret = batadv_parse_gw_bandwidth(net_dev, buff, &down_new, &up_new);
 191         if (!ret)
 192                 return -EINVAL;
 193
 194         if (!down_new)
 195                 down_new = 1;
 196
 197         if (!up_new)
 198                 up_new = down_new / 5;
 199
 200         if (!up_new)
 201                 up_new = 1;
 202
 203         if (down_curr == down_new && up_curr == up_new)
 204                 return count;
 205
 206         batadv_gw_reselect(bat_priv);
 207         batadv_info(net_dev,
 208                     "Changing gateway bandwidth from: '%u.%u/%u.%u MBit' to: '%u.%u/%u.%u MBit'\n",
 209                     down_curr / 10, down_curr % 10, up_curr / 10, up_curr % 10,
 210                     down_new / 10, down_new % 10, up_new / 10, up_new % 10);
 211
 212         atomic_set(&bat_priv->gw.bandwidth_down, down_new);
 213         atomic_set(&bat_priv->gw.bandwidth_up, up_new);
 214         batadv_gw_tvlv_container_update(bat_priv);
 215
 216         return count;
 217 }
 218
 219 /**
 220  * batadv_gw_tvlv_ogm_handler_v1() - process incoming gateway tvlv container
 221  * @bat_priv: the bat priv with all the soft interface information
 222  * @orig: the orig_node of the ogm
 223  * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
 224  * @tvlv_value: tvlv buffer containing the gateway data
 225  * @tvlv_value_len: tvlv buffer length
 226  */
 227 static void batadv_gw_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
 228                                           struct batadv_orig_node *orig,
 229                                           u8 flags,
 230                                           void *tvlv_value, u16 tvlv_value_len)
 231 {
 232         struct batadv_tvlv_gateway_data gateway, *gateway_ptr;
 233
 234         /* only fetch the tvlv value if the handler wasn't called via the
 235          * CIFNOTFND flag and if there is data to fetch
 236          */
 237         if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND ||
 238             tvlv_value_len < sizeof(gateway)) {
 239                 gateway.bandwidth_down = 0;
 240                 gateway.bandwidth_up = 0;
 241         } else {
 242                 gateway_ptr = tvlv_value;
 243                 gateway.bandwidth_down = gateway_ptr->bandwidth_down;
 244                 gateway.bandwidth_up = gateway_ptr->bandwidth_up;
 245                 if (gateway.bandwidth_down == 0 ||
 246                     gateway.bandwidth_up == 0) {
 247                         gateway.bandwidth_down = 0;
 248                         gateway.bandwidth_up = 0;
 249                 }
 250         }
 251
 252         batadv_gw_node_update(bat_priv, orig, &gateway);
 253
 254         /* restart gateway selection */
 255         if (gateway.bandwidth_down != 0 &&
 256             atomic_read(&bat_priv->gw.mode) == BATADV_GW_MODE_CLIENT)
 257                 batadv_gw_check_election(bat_priv, orig);
 258 }
 259
 260 /**
 261  * batadv_gw_init() - initialise the gateway handling internals
 262  * @bat_priv: the bat priv with all the soft interface information
 263  */
 264 void batadv_gw_init(struct batadv_priv *bat_priv)
 265 {
 266         if (bat_priv->algo_ops->gw.init_sel_class)
 267                 bat_priv->algo_ops->gw.init_sel_class(bat_priv);
 268         else
 269                 atomic_set(&bat_priv->gw.sel_class, 1);
 270
 271         batadv_tvlv_handler_register(bat_priv, batadv_gw_tvlv_ogm_handler_v1,
 272                                      NULL, BATADV_TVLV_GW, 1,
 273                                      BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
 274 }
 275
 276 /**
 277  * batadv_gw_free() - free the gateway handling internals
 278  * @bat_priv: the bat priv with all the soft interface information
 279  */
 280 void batadv_gw_free(struct batadv_priv *bat_priv)
 281 {
 282         batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_GW, 1);
 283         batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_GW, 1);
 284 }