net/batman-adv/bat_algo.c

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