net/batman-adv/gateway_common.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (C) 2009-2019  B.A.T.M.A.N. contributors:
   3  *
   4  * Marek Lindner
   5  */
   6
   7 #include "gateway_common.h"
   8 #include "main.h"
   9
  10 #include <linux/atomic.h>
  11 #include <linux/byteorder/generic.h>
  12 #include <linux/errno.h>
  13 #include <linux/kernel.h>
  14 #include <linux/math64.h>
  15 #include <linux/netdevice.h>
  16 #include <linux/stddef.h>
  17 #include <linux/string.h>
  18 #include <uapi/linux/batadv_packet.h>
  19 #include <uapi/linux/batman_adv.h>
  20
  21 #include "gateway_client.h"
  22 #include "log.h"
  23 #include "tvlv.h"
  24
  25 /**
  26  * batadv_parse_throughput() - parse supplied string buffer to extract
  27  *  throughput information
  28  * @net_dev: the soft interface net device
  29  * @buff: string buffer to parse
  30  * @description: text shown when throughput string cannot be parsed
  31  * @throughput: pointer holding the returned throughput information
  32  *
  33  * Return: false on parse error and true otherwise.
  34  */
  35 bool batadv_parse_throughput(struct net_device *net_dev, char *buff,
  36                              const char *description, u32 *throughput)
  37 {
  38         enum batadv_bandwidth_units bw_unit_type = BATADV_BW_UNIT_KBIT;
  39         u64 lthroughput;
  40         char *tmp_ptr;
  41         int ret;
  42
  43         if (strlen(buff) > 4) {
  44                 tmp_ptr = buff + strlen(buff) - 4;
  45
  46                 if (strncasecmp(tmp_ptr, "mbit", 4) == 0)
  47                         bw_unit_type = BATADV_BW_UNIT_MBIT;
  48
  49                 if (strncasecmp(tmp_ptr, "kbit", 4) == 0 ||
  50                     bw_unit_type == BATADV_BW_UNIT_MBIT)
  51                         *tmp_ptr = '\0';
  52         }
  53
  54         ret = kstrtou64(buff, 10, &lthroughput);
  55         if (ret) {
  56                 batadv_err(net_dev,
  57                            "Invalid throughput speed for %s: %s\n",
  58                            description, buff);
  59                 return false;
  60         }
  61
  62         switch (bw_unit_type) {
  63         case BATADV_BW_UNIT_MBIT:
  64                 /* prevent overflow */
  65                 if (U64_MAX / 10 < lthroughput) {
  66                         batadv_err(net_dev,
  67                                    "Throughput speed for %s too large: %s\n",
  68                                    description, buff);
  69                         return false;
  70                 }
  71
  72                 lthroughput *= 10;
  73                 break;
  74         case BATADV_BW_UNIT_KBIT:
  75         default:
  76                 lthroughput = div_u64(lthroughput, 100);
  77                 break;
  78         }
  79
  80         if (lthroughput > U32_MAX) {
  81                 batadv_err(net_dev,
  82                            "Throughput speed for %s too large: %s\n",
  83                            description, buff);
  84                 return false;
  85         }
  86
  87         *throughput = lthroughput;
  88
  89         return true;
  90 }
  91
  92 /**
  93  * batadv_parse_gw_bandwidth() - parse supplied string buffer to extract
  94  *  download and upload bandwidth information
  95  * @net_dev: the soft interface net device
  96  * @buff: string buffer to parse
  97  * @down: pointer holding the returned download bandwidth information
  98  * @up: pointer holding the returned upload bandwidth information
  99  *
 100  * Return: false on parse error and true otherwise.
 101  */
 102 static bool batadv_parse_gw_bandwidth(struct net_device *net_dev, char *buff,
 103                                       u32 *down, u32 *up)
 104 {
 105         char *slash_ptr;
 106         bool ret;
 107
 108         slash_ptr = strchr(buff, '/');
 109         if (slash_ptr)
 110                 *slash_ptr = 0;
 111
 112         ret = batadv_parse_throughput(net_dev, buff, "download gateway speed",
 113                                       down);
 114         if (!ret)
 115                 return false;
 116
 117         /* we also got some upload info */
 118         if (slash_ptr) {
 119                 ret = batadv_parse_throughput(net_dev, slash_ptr + 1,
 120                                               "upload gateway speed", up);
 121                 if (!ret)
 122                         return false;
 123         }
 124
 125         return true;
 126 }
 127
 128 /**
 129  * batadv_gw_tvlv_container_update() - update the gw tvlv container after
 130  *  gateway setting change
 131  * @bat_priv: the bat priv with all the soft interface information
 132  */
 133 void batadv_gw_tvlv_container_update(struct batadv_priv *bat_priv)
 134 {
 135         struct batadv_tvlv_gateway_data gw;
 136         u32 down, up;
 137         char gw_mode;
 138
 139         gw_mode = atomic_read(&bat_priv->gw.mode);
 140
 141         switch (gw_mode) {
 142         case BATADV_GW_MODE_OFF:
 143         case BATADV_GW_MODE_CLIENT:
 144                 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_GW, 1);
 145                 break;
 146         case BATADV_GW_MODE_SERVER:
 147                 down = atomic_read(&bat_priv->gw.bandwidth_down);
 148                 up = atomic_read(&bat_priv->gw.bandwidth_up);
 149                 gw.bandwidth_down = htonl(down);
 150                 gw.bandwidth_up = htonl(up);
 151                 batadv_tvlv_container_register(bat_priv, BATADV_TVLV_GW, 1,
 152                                                &gw, sizeof(gw));
 153                 break;
 154         }
 155 }
 156
 157 /**
 158  * batadv_gw_bandwidth_set() - Parse and set download/upload gateway bandwidth
 159  *  from supplied string buffer
 160  * @net_dev: netdev struct of the soft interface
 161  * @buff: the buffer containing the user data
 162  * @count: number of bytes in the buffer
 163  *
 164  * Return: 'count' on success or a negative error code in case of failure
 165  */
 166 ssize_t batadv_gw_bandwidth_set(struct net_device *net_dev, char *buff,
 167                                 size_t count)
 168 {
 169         struct batadv_priv *bat_priv = netdev_priv(net_dev);
 170         u32 down_curr;
 171         u32 up_curr;
 172         u32 down_new = 0;
 173         u32 up_new = 0;
 174         bool ret;
 175
 176         down_curr = (unsigned int)atomic_read(&bat_priv->gw.bandwidth_down);
 177         up_curr = (unsigned int)atomic_read(&bat_priv->gw.bandwidth_up);
 178
 179         ret = batadv_parse_gw_bandwidth(net_dev, buff, &down_new, &up_new);
 180         if (!ret)
 181                 return -EINVAL;
 182
 183         if (!down_new)
 184                 down_new = 1;
 185
 186         if (!up_new)
 187                 up_new = down_new / 5;
 188
 189         if (!up_new)
 190                 up_new = 1;
 191
 192         if (down_curr == down_new && up_curr == up_new)
 193                 return count;
 194
 195         batadv_gw_reselect(bat_priv);
 196         batadv_info(net_dev,
 197                     "Changing gateway bandwidth from: '%u.%u/%u.%u MBit' to: '%u.%u/%u.%u MBit'\n",
 198                     down_curr / 10, down_curr % 10, up_curr / 10, up_curr % 10,
 199                     down_new / 10, down_new % 10, up_new / 10, up_new % 10);
 200
 201         atomic_set(&bat_priv->gw.bandwidth_down, down_new);
 202         atomic_set(&bat_priv->gw.bandwidth_up, up_new);
 203         batadv_gw_tvlv_container_update(bat_priv);
 204
 205         return count;
 206 }
 207
 208 /**
 209  * batadv_gw_tvlv_ogm_handler_v1() - process incoming gateway tvlv container
 210  * @bat_priv: the bat priv with all the soft interface information
 211  * @orig: the orig_node of the ogm
 212  * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
 213  * @tvlv_value: tvlv buffer containing the gateway data
 214  * @tvlv_value_len: tvlv buffer length
 215  */
 216 static void batadv_gw_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
 217                                           struct batadv_orig_node *orig,
 218                                           u8 flags,
 219                                           void *tvlv_value, u16 tvlv_value_len)
 220 {
 221         struct batadv_tvlv_gateway_data gateway, *gateway_ptr;
 222
 223         /* only fetch the tvlv value if the handler wasn't called via the
 224          * CIFNOTFND flag and if there is data to fetch
 225          */
 226         if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND ||
 227             tvlv_value_len < sizeof(gateway)) {
 228                 gateway.bandwidth_down = 0;
 229                 gateway.bandwidth_up = 0;
 230         } else {
 231                 gateway_ptr = tvlv_value;
 232                 gateway.bandwidth_down = gateway_ptr->bandwidth_down;
 233                 gateway.bandwidth_up = gateway_ptr->bandwidth_up;
 234                 if (gateway.bandwidth_down == 0 ||
 235                     gateway.bandwidth_up == 0) {
 236                         gateway.bandwidth_down = 0;
 237                         gateway.bandwidth_up = 0;
 238                 }
 239         }
 240
 241         batadv_gw_node_update(bat_priv, orig, &gateway);
 242
 243         /* restart gateway selection */
 244         if (gateway.bandwidth_down != 0 &&
 245             atomic_read(&bat_priv->gw.mode) == BATADV_GW_MODE_CLIENT)
 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         if (bat_priv->algo_ops->gw.init_sel_class)
 256                 bat_priv->algo_ops->gw.init_sel_class(bat_priv);
 257         else
 258                 atomic_set(&bat_priv->gw.sel_class, 1);
 259
 260         batadv_tvlv_handler_register(bat_priv, batadv_gw_tvlv_ogm_handler_v1,
 261                                      NULL, BATADV_TVLV_GW, 1,
 262                                      BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
 263 }
 264
 265 /**
 266  * batadv_gw_free() - free the gateway handling internals
 267  * @bat_priv: the bat priv with all the soft interface information
 268  */
 269 void batadv_gw_free(struct batadv_priv *bat_priv)
 270 {
 271         batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_GW, 1);
 272         batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_GW, 1);
 273 }