net/batman-adv/bat_algo.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (C) 2007-2017  B.A.T.M.A.N. contributors:
   3  *
   4  * Marek Lindner, Simon Wunderlich
   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 "main.h"
  20
  21 #include <linux/errno.h>
  22 #include <linux/list.h>
  23 #include <linux/moduleparam.h>
  24 #include <linux/netlink.h>
  25 #include <linux/printk.h>
  26 #include <linux/seq_file.h>
  27 #include <linux/skbuff.h>
  28 #include <linux/stddef.h>
  29 #include <linux/string.h>
  30 #include <net/genetlink.h>
  31 #include <net/netlink.h>
  32 #include <uapi/linux/batman_adv.h>
  33
  34 #include "bat_algo.h"
  35 #include "netlink.h"
  36
  37 char batadv_routing_algo[20] = "BATMAN_IV";
  38 static struct hlist_head batadv_algo_list;
  39
  40 /**
  41  * batadv_algo_init() - Initialize batman-adv algorithm management data
  42  *  structures
  43  */
  44 void batadv_algo_init(void)
  45 {
  46         INIT_HLIST_HEAD(&batadv_algo_list);
  47 }
  48
  49 static struct batadv_algo_ops *batadv_algo_get(char *name)
  50 {
  51         struct batadv_algo_ops *bat_algo_ops = NULL, *bat_algo_ops_tmp;
  52
  53         hlist_for_each_entry(bat_algo_ops_tmp, &batadv_algo_list, list) {
  54                 if (strcmp(bat_algo_ops_tmp->name, name) != 0)
  55                         continue;
  56
  57                 bat_algo_ops = bat_algo_ops_tmp;
  58                 break;
  59         }
  60
  61         return bat_algo_ops;
  62 }
  63
  64 /**
  65  * batadv_algo_register() - Register callbacks for a mesh algorithm
  66  * @bat_algo_ops: mesh algorithm callbacks to add
  67  *
  68  * Return: 0 on success or negative error number in case of failure
  69  */
  70 int batadv_algo_register(struct batadv_algo_ops *bat_algo_ops)
  71 {
  72         struct batadv_algo_ops *bat_algo_ops_tmp;
  73
  74         bat_algo_ops_tmp = batadv_algo_get(bat_algo_ops->name);
  75         if (bat_algo_ops_tmp) {
  76                 pr_info("Trying to register already registered routing algorithm: %s\n",
  77                         bat_algo_ops->name);
  78                 return -EEXIST;
  79         }
  80
  81         /* all algorithms must implement all ops (for now) */
  82         if (!bat_algo_ops->iface.enable ||
  83             !bat_algo_ops->iface.disable ||
  84             !bat_algo_ops->iface.update_mac ||
  85             !bat_algo_ops->iface.primary_set ||
  86             !bat_algo_ops->neigh.cmp ||
  87             !bat_algo_ops->neigh.is_similar_or_better) {
  88                 pr_info("Routing algo '%s' does not implement required ops\n",
  89                         bat_algo_ops->name);
  90                 return -EINVAL;
  91         }
  92
  93         INIT_HLIST_NODE(&bat_algo_ops->list);
  94         hlist_add_head(&bat_algo_ops->list, &batadv_algo_list);
  95
  96         return 0;
  97 }
  98
  99 /**
 100  * batadv_algo_select() - Select algorithm of soft interface
 101  * @bat_priv: the bat priv with all the soft interface information
 102  * @name: name of the algorithm to select
 103  *
 104  * The algorithm callbacks for the soft interface will be set when the algorithm
 105  * with the correct name was found. Any previous selected algorithm will not be
 106  * deinitialized and the new selected algorithm will also not be initialized.
 107  * It is therefore not allowed to call batadv_algo_select outside the creation
 108  * function of the soft interface.
 109  *
 110  * Return: 0 on success or negative error number in case of failure
 111  */
 112 int batadv_algo_select(struct batadv_priv *bat_priv, char *name)
 113 {
 114         struct batadv_algo_ops *bat_algo_ops;
 115
 116         bat_algo_ops = batadv_algo_get(name);
 117         if (!bat_algo_ops)
 118                 return -EINVAL;
 119
 120         bat_priv->algo_ops = bat_algo_ops;
 121
 122         return 0;
 123 }
 124
 125 #ifdef CONFIG_BATMAN_ADV_DEBUGFS
 126
 127 /**
 128  * batadv_algo_seq_print_text() - Print the supported algorithms in a seq file
 129  * @seq: seq file to print on
 130  * @offset: not used
 131  *
 132  * Return: always 0
 133  */
 134 int batadv_algo_seq_print_text(struct seq_file *seq, void *offset)
 135 {
 136         struct batadv_algo_ops *bat_algo_ops;
 137
 138         seq_puts(seq, "Available routing algorithms:\n");
 139
 140         hlist_for_each_entry(bat_algo_ops, &batadv_algo_list, list) {
 141                 seq_printf(seq, " * %s\n", bat_algo_ops->name);
 142         }
 143
 144         return 0;
 145 }
 146 #endif
 147
 148 static int batadv_param_set_ra(const char *val, const struct kernel_param *kp)
 149 {
 150         struct batadv_algo_ops *bat_algo_ops;
 151         char *algo_name = (char *)val;
 152         size_t name_len = strlen(algo_name);
 153
 154         if (name_len > 0 && algo_name[name_len - 1] == '\n')
 155                 algo_name[name_len - 1] = '\0';
 156
 157         bat_algo_ops = batadv_algo_get(algo_name);
 158         if (!bat_algo_ops) {
 159                 pr_err("Routing algorithm '%s' is not supported\n", algo_name);
 160                 return -EINVAL;
 161         }
 162
 163         return param_set_copystring(algo_name, kp);
 164 }
 165
 166 static const struct kernel_param_ops batadv_param_ops_ra = {
 167         .set = batadv_param_set_ra,
 168         .get = param_get_string,
 169 };
 170
 171 static struct kparam_string batadv_param_string_ra = {
 172         .maxlen = sizeof(batadv_routing_algo),
 173         .string = batadv_routing_algo,
 174 };
 175
 176 module_param_cb(routing_algo, &batadv_param_ops_ra, &batadv_param_string_ra,
 177                 0644);
 178
 179 /**
 180  * batadv_algo_dump_entry() - fill in information about one supported routing
 181  *  algorithm
 182  * @msg: netlink message to be sent back
 183  * @portid: Port to reply to
 184  * @seq: Sequence number of message
 185  * @bat_algo_ops: Algorithm to be dumped
 186  *
 187  * Return: Error number, or 0 on success
 188  */
 189 static int batadv_algo_dump_entry(struct sk_buff *msg, u32 portid, u32 seq,
 190                                   struct batadv_algo_ops *bat_algo_ops)
 191 {
 192         void *hdr;
 193
 194         hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family,
 195                           NLM_F_MULTI, BATADV_CMD_GET_ROUTING_ALGOS);
 196         if (!hdr)
 197                 return -EMSGSIZE;
 198
 199         if (nla_put_string(msg, BATADV_ATTR_ALGO_NAME, bat_algo_ops->name))
 200                 goto nla_put_failure;
 201
 202         genlmsg_end(msg, hdr);
 203         return 0;
 204
 205  nla_put_failure:
 206         genlmsg_cancel(msg, hdr);
 207         return -EMSGSIZE;
 208 }
 209
 210 /**
 211  * batadv_algo_dump() - fill in information about supported routing
 212  *  algorithms
 213  * @msg: netlink message to be sent back
 214  * @cb: Parameters to the netlink request
 215  *
 216  * Return: Length of reply message.
 217  */
 218 int batadv_algo_dump(struct sk_buff *msg, struct netlink_callback *cb)
 219 {
 220         int portid = NETLINK_CB(cb->skb).portid;
 221         struct batadv_algo_ops *bat_algo_ops;
 222         int skip = cb->args[0];
 223         int i = 0;
 224
 225         hlist_for_each_entry(bat_algo_ops, &batadv_algo_list, list) {
 226                 if (i++ < skip)
 227                         continue;
 228
 229                 if (batadv_algo_dump_entry(msg, portid, cb->nlh->nlmsg_seq,
 230                                            bat_algo_ops)) {
 231                         i--;
 232                         break;
 233                 }
 234         }
 235
 236         cb->args[0] = i;
 237
 238         return msg->len;
 239 }