net/batman-adv/bat_algo.c

   1 /* Copyright (C) 2007-2017  B.A.T.M.A.N. contributors:
   2  *
   3  * Marek Lindner, Simon Wunderlich
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of version 2 of the GNU General Public
   7  * License as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include "main.h"
  19
  20 #include <linux/errno.h>
  21 #include <linux/list.h>
  22 #include <linux/moduleparam.h>
  23 #include <linux/netlink.h>
  24 #include <linux/printk.h>
  25 #include <linux/seq_file.h>
  26 #include <linux/skbuff.h>
  27 #include <linux/stddef.h>
  28 #include <linux/string.h>
  29 #include <net/genetlink.h>
  30 #include <net/netlink.h>
  31 #include <uapi/linux/batman_adv.h>
  32
  33 #include "bat_algo.h"
  34 #include "netlink.h"
  35
  36 char batadv_routing_algo[20] = "BATMAN_IV";
  37 static struct hlist_head batadv_algo_list;
  38
  39 /**
  40  * batadv_algo_init - Initialize batman-adv algorithm management data structures
  41  */
  42 void batadv_algo_init(void)
  43 {
  44         INIT_HLIST_HEAD(&batadv_algo_list);
  45 }
  46
  47 static struct batadv_algo_ops *batadv_algo_get(char *name)
  48 {
  49         struct batadv_algo_ops *bat_algo_ops = NULL, *bat_algo_ops_tmp;
  50
  51         hlist_for_each_entry(bat_algo_ops_tmp, &batadv_algo_list, list) {
  52                 if (strcmp(bat_algo_ops_tmp->name, name) != 0)
  53                         continue;
  54
  55                 bat_algo_ops = bat_algo_ops_tmp;
  56                 break;
  57         }
  58
  59         return bat_algo_ops;
  60 }
  61
  62 int batadv_algo_register(struct batadv_algo_ops *bat_algo_ops)
  63 {
  64         struct batadv_algo_ops *bat_algo_ops_tmp;
  65
  66         bat_algo_ops_tmp = batadv_algo_get(bat_algo_ops->name);
  67         if (bat_algo_ops_tmp) {
  68                 pr_info("Trying to register already registered routing algorithm: %s\n",
  69                         bat_algo_ops->name);
  70                 return -EEXIST;
  71         }
  72
  73         /* all algorithms must implement all ops (for now) */
  74         if (!bat_algo_ops->iface.enable ||
  75             !bat_algo_ops->iface.disable ||
  76             !bat_algo_ops->iface.update_mac ||
  77             !bat_algo_ops->iface.primary_set ||
  78             !bat_algo_ops->neigh.cmp ||
  79             !bat_algo_ops->neigh.is_similar_or_better) {
  80                 pr_info("Routing algo '%s' does not implement required ops\n",
  81                         bat_algo_ops->name);
  82                 return -EINVAL;
  83         }
  84
  85         INIT_HLIST_NODE(&bat_algo_ops->list);
  86         hlist_add_head(&bat_algo_ops->list, &batadv_algo_list);
  87
  88         return 0;
  89 }
  90
  91 int batadv_algo_select(struct batadv_priv *bat_priv, char *name)
  92 {
  93         struct batadv_algo_ops *bat_algo_ops;
  94
  95         bat_algo_ops = batadv_algo_get(name);
  96         if (!bat_algo_ops)
  97                 return -EINVAL;
  98
  99         bat_priv->algo_ops = bat_algo_ops;
 100
 101         return 0;
 102 }
 103
 104 #ifdef CONFIG_BATMAN_ADV_DEBUGFS
 105 int batadv_algo_seq_print_text(struct seq_file *seq, void *offset)
 106 {
 107         struct batadv_algo_ops *bat_algo_ops;
 108
 109         seq_puts(seq, "Available routing algorithms:\n");
 110
 111         hlist_for_each_entry(bat_algo_ops, &batadv_algo_list, list) {
 112                 seq_printf(seq, " * %s\n", bat_algo_ops->name);
 113         }
 114
 115         return 0;
 116 }
 117 #endif
 118
 119 static int batadv_param_set_ra(const char *val, const struct kernel_param *kp)
 120 {
 121         struct batadv_algo_ops *bat_algo_ops;
 122         char *algo_name = (char *)val;
 123         size_t name_len = strlen(algo_name);
 124
 125         if (name_len > 0 && algo_name[name_len - 1] == '\n')
 126                 algo_name[name_len - 1] = '\0';
 127
 128         bat_algo_ops = batadv_algo_get(algo_name);
 129         if (!bat_algo_ops) {
 130                 pr_err("Routing algorithm '%s' is not supported\n", algo_name);
 131                 return -EINVAL;
 132         }
 133
 134         return param_set_copystring(algo_name, kp);
 135 }
 136
 137 static const struct kernel_param_ops batadv_param_ops_ra = {
 138         .set = batadv_param_set_ra,
 139         .get = param_get_string,
 140 };
 141
 142 static struct kparam_string batadv_param_string_ra = {
 143         .maxlen = sizeof(batadv_routing_algo),
 144         .string = batadv_routing_algo,
 145 };
 146
 147 module_param_cb(routing_algo, &batadv_param_ops_ra, &batadv_param_string_ra,
 148                 0644);
 149
 150 /**
 151  * batadv_algo_dump_entry - fill in information about one supported routing
 152  *  algorithm
 153  * @msg: netlink message to be sent back
 154  * @portid: Port to reply to
 155  * @seq: Sequence number of message
 156  * @bat_algo_ops: Algorithm to be dumped
 157  *
 158  * Return: Error number, or 0 on success
 159  */
 160 static int batadv_algo_dump_entry(struct sk_buff *msg, u32 portid, u32 seq,
 161                                   struct batadv_algo_ops *bat_algo_ops)
 162 {
 163         void *hdr;
 164
 165         hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family,
 166                           NLM_F_MULTI, BATADV_CMD_GET_ROUTING_ALGOS);
 167         if (!hdr)
 168                 return -EMSGSIZE;
 169
 170         if (nla_put_string(msg, BATADV_ATTR_ALGO_NAME, bat_algo_ops->name))
 171                 goto nla_put_failure;
 172
 173         genlmsg_end(msg, hdr);
 174         return 0;
 175
 176  nla_put_failure:
 177         genlmsg_cancel(msg, hdr);
 178         return -EMSGSIZE;
 179 }
 180
 181 /**
 182  * batadv_algo_dump - fill in information about supported routing
 183  *  algorithms
 184  * @msg: netlink message to be sent back
 185  * @cb: Parameters to the netlink request
 186  *
 187  * Return: Length of reply message.
 188  */
 189 int batadv_algo_dump(struct sk_buff *msg, struct netlink_callback *cb)
 190 {
 191         int portid = NETLINK_CB(cb->skb).portid;
 192         struct batadv_algo_ops *bat_algo_ops;
 193         int skip = cb->args[0];
 194         int i = 0;
 195
 196         hlist_for_each_entry(bat_algo_ops, &batadv_algo_list, list) {
 197                 if (i++ < skip)
 198                         continue;
 199
 200                 if (batadv_algo_dump_entry(msg, portid, cb->nlh->nlmsg_seq,
 201                                            bat_algo_ops)) {
 202                         i--;
 203                         break;
 204                 }
 205         }
 206
 207         cb->args[0] = i;
 208
 209         return msg->len;
 210 }