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
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
37static 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 */
58int 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 */
100int 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 */
122int 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
136static 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
154static const struct kernel_param_ops batadv_param_ops_ra = {
155	.set = batadv_param_set_ra,
156	.get = param_get_string,
157};
158
159static struct kparam_string batadv_param_string_ra = {
160	.maxlen = sizeof(batadv_routing_algo),
161	.string = batadv_routing_algo,
162};
163
164module_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 */
177static 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 */
206int 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}
228