net/batman-adv/bat_algo.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (C) 2007-2020  B.A.T.M.A.N. contributors:
   3  *
   4  * Marek Lindner, Simon Wunderlich
   5  */
   6
   7 #include "main.h"
   8
   9 #include <linux/errno.h>
  10 #include <linux/list.h>
  11 #include <linux/moduleparam.h>
  12 #include <linux/netlink.h>
  13 #include <linux/printk.h>
  14 #include <linux/seq_file.h>
  15 #include <linux/skbuff.h>
  16 #include <linux/stddef.h>
  17 #include <linux/string.h>
  18 #include <net/genetlink.h>
  19 #include <net/netlink.h>
  20 #include <uapi/linux/batman_adv.h>
  21
  22 #include "bat_algo.h"
  23 #include "netlink.h"
  24
  25 char batadv_routing_algo[20] = "BATMAN_IV";
  26 static struct hlist_head batadv_algo_list;
  27
  28 /**
  29  * batadv_algo_init() - Initialize batman-adv algorithm management data
  30  *  structures
  31  */
  32 void batadv_algo_init(void)
  33 {
  34         INIT_HLIST_HEAD(&batadv_algo_list);
  35 }
  36
  37 static struct batadv_algo_ops *batadv_algo_get(char *name)
  38 {
  39         struct batadv_algo_ops *bat_algo_ops = NULL, *bat_algo_ops_tmp;
  40
  41         hlist_for_each_entry(bat_algo_ops_tmp, &batadv_algo_list, list) {
  42                 if (strcmp(bat_algo_ops_tmp->name, name) != 0)
  43                         continue;
  44
  45                 bat_algo_ops = bat_algo_ops_tmp;
  46                 break;
  47         }
  48
  49         return bat_algo_ops;
  50 }
  51
  52 /**
  53  * batadv_algo_register() - Register callbacks for a mesh algorithm
  54  * @bat_algo_ops: mesh algorithm callbacks to add
  55  *
  56  * Return: 0 on success or negative error number in case of failure
  57  */
  58 int batadv_algo_register(struct batadv_algo_ops *bat_algo_ops)
  59 {
  60         struct batadv_algo_ops *bat_algo_ops_tmp;
  61
  62         bat_algo_ops_tmp = batadv_algo_get(bat_algo_ops->name);
  63         if (bat_algo_ops_tmp) {
  64                 pr_info("Trying to register already registered routing algorithm: %s\n",
  65                         bat_algo_ops->name);
  66                 return -EEXIST;
  67         }
  68
  69         /* all algorithms must implement all ops (for now) */
  70         if (!bat_algo_ops->iface.enable ||
  71             !bat_algo_ops->iface.disable ||
  72             !bat_algo_ops->iface.update_mac ||
  73             !bat_algo_ops->iface.primary_set ||
  74             !bat_algo_ops->neigh.cmp ||
  75             !bat_algo_ops->neigh.is_similar_or_better) {
  76                 pr_info("Routing algo '%s' does not implement required ops\n",
  77                         bat_algo_ops->name);
  78                 return -EINVAL;
  79         }
  80
  81         INIT_HLIST_NODE(&bat_algo_ops->list);
  82         hlist_add_head(&bat_algo_ops->list, &batadv_algo_list);
  83
  84         return 0;
  85 }
  86
  87 /**
  88  * batadv_algo_select() - Select algorithm of soft interface
  89  * @bat_priv: the bat priv with all the soft interface information
  90  * @name: name of the algorithm to select
  91  *
  92  * The algorithm callbacks for the soft interface will be set when the algorithm
  93  * with the correct name was found. Any previous selected algorithm will not be
  94  * deinitialized and the new selected algorithm will also not be initialized.
  95  * It is therefore not allowed to call batadv_algo_select outside the creation
  96  * function of the soft interface.
  97  *
  98  * Return: 0 on success or negative error number in case of failure
  99  */
 100 int batadv_algo_select(struct batadv_priv *bat_priv, char *name)
 101 {
 102         struct batadv_algo_ops *bat_algo_ops;
 103
 104         bat_algo_ops = batadv_algo_get(name);
 105         if (!bat_algo_ops)
 106                 return -EINVAL;
 107
 108         bat_priv->algo_ops = bat_algo_ops;
 109
 110         return 0;
 111 }
 112
 113 #ifdef CONFIG_BATMAN_ADV_DEBUGFS
 114
 115 /**
 116  * batadv_algo_seq_print_text() - Print the supported algorithms in a seq file
 117  * @seq: seq file to print on
 118  * @offset: not used
 119  *
 120  * Return: always 0
 121  */
 122 int batadv_algo_seq_print_text(struct seq_file *seq, void *offset)
 123 {
 124         struct batadv_algo_ops *bat_algo_ops;
 125
 126         seq_puts(seq, "Available routing algorithms:\n");
 127
 128         hlist_for_each_entry(bat_algo_ops, &batadv_algo_list, list) {
 129                 seq_printf(seq, " * %s\n", bat_algo_ops->name);
 130         }
 131
 132         return 0;
 133 }
 134 #endif
 135
 136 static int batadv_param_set_ra(const char *val, const struct kernel_param *kp)
 137 {
 138         struct batadv_algo_ops *bat_algo_ops;
 139         char *algo_name = (char *)val;
 140         size_t name_len = strlen(algo_name);
 141
 142         if (name_len > 0 && algo_name[name_len - 1] == '\n')
 143                 algo_name[name_len - 1] = '\0';
 144
 145         bat_algo_ops = batadv_algo_get(algo_name);
 146         if (!bat_algo_ops) {
 147                 pr_err("Routing algorithm '%s' is not supported\n", algo_name);
 148                 return -EINVAL;
 149         }
 150
 151         return param_set_copystring(algo_name, kp);
 152 }
 153
 154 static const struct kernel_param_ops batadv_param_ops_ra = {
 155         .set = batadv_param_set_ra,
 156         .get = param_get_string,
 157 };
 158
 159 static struct kparam_string batadv_param_string_ra = {
 160         .maxlen = sizeof(batadv_routing_algo),
 161         .string = batadv_routing_algo,
 162 };
 163
 164 module_param_cb(routing_algo, &batadv_param_ops_ra, &batadv_param_string_ra,
 165                 0644);
 166
 167 /**
 168  * batadv_algo_dump_entry() - fill in information about one supported routing
 169  *  algorithm
 170  * @msg: netlink message to be sent back
 171  * @portid: Port to reply to
 172  * @seq: Sequence number of message
 173  * @bat_algo_ops: Algorithm to be dumped
 174  *
 175  * Return: Error number, or 0 on success
 176  */
 177 static int batadv_algo_dump_entry(struct sk_buff *msg, u32 portid, u32 seq,
 178                                   struct batadv_algo_ops *bat_algo_ops)
 179 {
 180         void *hdr;
 181
 182         hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family,
 183                           NLM_F_MULTI, BATADV_CMD_GET_ROUTING_ALGOS);
 184         if (!hdr)
 185                 return -EMSGSIZE;
 186
 187         if (nla_put_string(msg, BATADV_ATTR_ALGO_NAME, bat_algo_ops->name))
 188                 goto nla_put_failure;
 189
 190         genlmsg_end(msg, hdr);
 191         return 0;
 192
 193  nla_put_failure:
 194         genlmsg_cancel(msg, hdr);
 195         return -EMSGSIZE;
 196 }
 197
 198 /**
 199  * batadv_algo_dump() - fill in information about supported routing
 200  *  algorithms
 201  * @msg: netlink message to be sent back
 202  * @cb: Parameters to the netlink request
 203  *
 204  * Return: Length of reply message.
 205  */
 206 int batadv_algo_dump(struct sk_buff *msg, struct netlink_callback *cb)
 207 {
 208         int portid = NETLINK_CB(cb->skb).portid;
 209         struct batadv_algo_ops *bat_algo_ops;
 210         int skip = cb->args[0];
 211         int i = 0;
 212
 213         hlist_for_each_entry(bat_algo_ops, &batadv_algo_list, list) {
 214                 if (i++ < skip)
 215                         continue;
 216
 217                 if (batadv_algo_dump_entry(msg, portid, cb->nlh->nlmsg_seq,
 218                                            bat_algo_ops)) {
 219                         i--;
 220                         break;
 221                 }
 222         }
 223
 224         cb->args[0] = i;
 225
 226         return msg->len;
 227 }