net/batman-adv/gateway_common.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (C) 2009-2020  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/limits.h>
  15 #include <linux/math64.h>
  16 #include <linux/netdevice.h>
  17 #include <linux/stddef.h>
  18 #include <linux/string.h>
  19 #include <uapi/linux/batadv_packet.h>
  20 #include <uapi/linux/batman_adv.h>
  21
  22 #include "gateway_client.h"
  23 #include "log.h"
  24 #include "tvlv.h"
  25
  26 /**
  27  * batadv_parse_throughput() - parse supplied string buffer to extract
  28  *  throughput information
  29  * @net_dev: the soft interface net device
  30  * @buff: string buffer to parse
  31  * @description: text shown when throughput string cannot be parsed
  32  * @throughput: pointer holding the returned throughput information
  33  *
  34  * Return: false on parse error and true otherwise.
  35  */
  36 bool batadv_parse_throughput(struct net_device *net_dev, char *buff,
  37                              const char *description, u32 *throughput)
  38 {
  39         enum batadv_bandwidth_units bw_unit_type = BATADV_BW_UNIT_KBIT;
  40         u64 lthroughput;
  41         char *tmp_ptr;
  42         int ret;
  43
  44         if (strlen(buff) > 4) {
  45                 tmp_ptr = buff + strlen(buff) - 4;
  46
  47                 if (strncasecmp(tmp_ptr, "mbit", 4) == 0)
  48                         bw_unit_type = BATADV_BW_UNIT_MBIT;
  49
  50                 if (strncasecmp(tmp_ptr, "kbit", 4) == 0 ||
  51                     bw_unit_type == BATADV_BW_UNIT_MBIT)
  52                         *tmp_ptr = '\0';
  53         }
  54
  55         ret = kstrtou64(buff, 10, &lthroughput);
  56         if (ret) {
  57                 batadv_err(net_dev,
  58                            "Invalid throughput speed for %s: %s\n",
  59                            description, buff);
  60                 return false;
  61         }
  62
  63         switch (bw_unit_type) {
  64         case BATADV_BW_UNIT_MBIT:
  65                 /* prevent overflow */
  66                 if (U64_MAX / 10 < lthroughput) {
  67                         batadv_err(net_dev,
  68                                    "Throughput speed for %s too large: %s\n",
  69                                    description, buff);
  70                         return false;
  71                 }
  72
  73                 lthroughput *= 10;
  74                 break;
  75         case BATADV_BW_UNIT_KBIT:
  76         default:
  77                 lthroughput = div_u64(lthroughput, 100);
  78                 break;
  79         }
  80
  81         if (lthroughput > U32_MAX) {
  82                 batadv_err(net_dev,
  83                            "Throughput speed for %s too large: %s\n",
  84                            description, buff);
  85                 return false;
  86         }
  87
  88         *throughput = lthroughput;
  89
  90         return true;
  91 }
  92
  93 /**
  94  * batadv_parse_gw_bandwidth() - parse supplied string buffer to extract
  95  *  download and upload bandwidth information
  96  * @net_dev: the soft interface net device
  97  * @buff: string buffer to parse
  98  * @down: pointer holding the returned download bandwidth information
  99  * @up: pointer holding the returned upload bandwidth information
 100  *
 101  * Return: false on parse error and true otherwise.
 102  */
 103 static bool batadv_parse_gw_bandwidth(struct net_device *net_dev, char *buff,
 104                                       u32 *down, u32 *up)
 105 {
 106         char *slash_ptr;
 107         bool ret;
 108
 109         slash_ptr = strchr(buff, '/');
 110         if (slash_ptr)
 111                 *slash_ptr = 0;
 112
 113         ret = batadv_parse_throughput(net_dev, buff, "download gateway speed",
 114                                       down);
 115         if (!ret)
 116                 return false;
 117
 118         /* we also got some upload info */
 119         if (slash_ptr) {
 120                 ret = batadv_parse_throughput(net_dev, slash_ptr + 1,
 121                                               "upload gateway speed", up);
 122                 if (!ret)
 123                         return false;
 124         }
 125
 126         return true;
 127 }
 128
 129 /**
 130  * batadv_gw_tvlv_container_update() - update the gw tvlv container after
 131  *  gateway setting change
 132  * @bat_priv: the bat priv with all the soft interface information
 133  */
 134 void batadv_gw_tvlv_container_update(struct batadv_priv *bat_priv)
 135 {
 136         struct batadv_tvlv_gateway_data gw;
 137         u32 down, up;
 138         char gw_mode;
 139
 140         gw_mode = atomic_read(&bat_priv->gw.mode);
 141
 142         switch (gw_mode) {
 143         case BATADV_GW_MODE_OFF:
 144         case BATADV_GW_MODE_CLIENT:
 145                 batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_GW, 1);
 146                 break;
 147         case BATADV_GW_MODE_SERVER:
 148                 down = atomic_read(&bat_priv->gw.bandwidth_down);
 149                 up = atomic_read(&bat_priv->gw.bandwidth_up);
 150                 gw.bandwidth_down = htonl(down);
 151                 gw.bandwidth_up = htonl(up);
 152                 batadv_tvlv_container_register(bat_priv, BATADV_TVLV_GW, 1,
 153                                                &gw, sizeof(gw));
 154                 break;
 155         }
 156 }
 157
 158 /**
 159  * batadv_gw_bandwidth_set() - Parse and set download/upload gateway bandwidth
 160  *  from supplied string buffer
 161  * @net_dev: netdev struct of the soft interface
 162  * @buff: the buffer containing the user data
 163  * @count: number of bytes in the buffer
 164  *
 165  * Return: 'count' on success or a negative error code in case of failure
 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 */
 245         if (gateway.bandwidth_down != 0 &&
 246             atomic_read(&bat_priv->gw.mode) == BATADV_GW_MODE_CLIENT)
 247                 batadv_gw_check_election(bat_priv, orig);
 248 }
 249
 250 /**
 251  * batadv_gw_init() - initialise the gateway handling internals
 252  * @bat_priv: the bat priv with all the soft interface information
 253  */
 254 void batadv_gw_init(struct batadv_priv *bat_priv)
 255 {
 256         if (bat_priv->algo_ops->gw.init_sel_class)
 257                 bat_priv->algo_ops->gw.init_sel_class(bat_priv);
 258         else
 259                 atomic_set(&bat_priv->gw.sel_class, 1);
 260
 261         batadv_tvlv_handler_register(bat_priv, batadv_gw_tvlv_ogm_handler_v1,
 262                                      NULL, BATADV_TVLV_GW, 1,
 263                                      BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
 264 }
 265
 266 /**
 267  * batadv_gw_free() - free the gateway handling internals
 268  * @bat_priv: the bat priv with all the soft interface information
 269  */
 270 void batadv_gw_free(struct batadv_priv *bat_priv)
 271 {
 272         batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_GW, 1);
 273         batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_GW, 1);
 274 }