linux/net/batman-adv/gateway_common.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/* Copyright (C) 2009-2018  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 */
  46bool 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 */
 113static 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 */
 144void 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 */
 177ssize_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 */
 227static 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 */
 264void 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 */
 280void 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}
 285