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 <linux/types.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 /** 38 * batadv_algo_get() - Search for algorithm with specific name 39 * @name: algorithm name to find 40 * 41 * Return: Pointer to batadv_algo_ops on success, NULL otherwise 42 */ 43 struct batadv_algo_ops *batadv_algo_get(const char *name) 44 { 45 struct batadv_algo_ops *bat_algo_ops = NULL, *bat_algo_ops_tmp; 46 47 hlist_for_each_entry(bat_algo_ops_tmp, &batadv_algo_list, list) { 48 if (strcmp(bat_algo_ops_tmp->name, name) != 0) 49 continue; 50 51 bat_algo_ops = bat_algo_ops_tmp; 52 break; 53 } 54 55 return bat_algo_ops; 56 } 57 58 /** 59 * batadv_algo_register() - Register callbacks for a mesh algorithm 60 * @bat_algo_ops: mesh algorithm callbacks to add 61 * 62 * Return: 0 on success or negative error number in case of failure 63 */ 64 int batadv_algo_register(struct batadv_algo_ops *bat_algo_ops) 65 { 66 struct batadv_algo_ops *bat_algo_ops_tmp; 67 68 bat_algo_ops_tmp = batadv_algo_get(bat_algo_ops->name); 69 if (bat_algo_ops_tmp) { 70 pr_info("Trying to register already registered routing algorithm: %s\n", 71 bat_algo_ops->name); 72 return -EEXIST; 73 } 74 75 /* all algorithms must implement all ops (for now) */ 76 if (!bat_algo_ops->iface.enable || 77 !bat_algo_ops->iface.disable || 78 !bat_algo_ops->iface.update_mac || 79 !bat_algo_ops->iface.primary_set || 80 !bat_algo_ops->neigh.cmp || 81 !bat_algo_ops->neigh.is_similar_or_better) { 82 pr_info("Routing algo '%s' does not implement required ops\n", 83 bat_algo_ops->name); 84 return -EINVAL; 85 } 86 87 INIT_HLIST_NODE(&bat_algo_ops->list); 88 hlist_add_head(&bat_algo_ops->list, &batadv_algo_list); 89 90 return 0; 91 } 92 93 /** 94 * batadv_algo_select() - Select algorithm of mesh interface 95 * @bat_priv: the bat priv with all the mesh interface information 96 * @name: name of the algorithm to select 97 * 98 * The algorithm callbacks for the mesh interface will be set when the algorithm 99 * with the correct name was found. Any previous selected algorithm will not be 100 * deinitialized and the new selected algorithm will also not be initialized. 101 * It is therefore not allowed to call batadv_algo_select outside the creation 102 * function of the mesh interface. 103 * 104 * Return: 0 on success or negative error number in case of failure 105 */ 106 int batadv_algo_select(struct batadv_priv *bat_priv, const char *name) 107 { 108 struct batadv_algo_ops *bat_algo_ops; 109 110 bat_algo_ops = batadv_algo_get(name); 111 if (!bat_algo_ops) 112 return -EINVAL; 113 114 bat_priv->algo_ops = bat_algo_ops; 115 116 return 0; 117 } 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 } 211