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 <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
 25char batadv_routing_algo[20] = "BATMAN_IV";
 26static struct hlist_head batadv_algo_list;
 27
 28/**
 29 * batadv_algo_init() - Initialize batman-adv algorithm management data
 30 *  structures
 31 */
 32void 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 */
 43struct 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 */
 64int 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 */
106int 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
119static 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
137static const struct kernel_param_ops batadv_param_ops_ra = {
138	.set = batadv_param_set_ra,
139	.get = param_get_string,
140};
141
142static struct kparam_string batadv_param_string_ra = {
143	.maxlen = sizeof(batadv_routing_algo),
144	.string = batadv_routing_algo,
145};
146
147module_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 */
160static 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 */
189int 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}