1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2007-2018 B.A.T.M.A.N. contributors:
3 *
4 * Marek Lindner, Simon Wunderlich
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of version 2 of the GNU General Public
8 * License as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, see <http://www.gnu.org/licenses/>.
17 */
18
19 #include "main.h"
20
21 #include <linux/errno.h>
22 #include <linux/list.h>
23 #include <linux/moduleparam.h>
24 #include <linux/netlink.h>
25 #include <linux/printk.h>
26 #include <linux/seq_file.h>
27 #include <linux/skbuff.h>
28 #include <linux/stddef.h>
29 #include <linux/string.h>
30 #include <net/genetlink.h>
31 #include <net/netlink.h>
32 #include <uapi/linux/batman_adv.h>
33
34 #include "bat_algo.h"
35 #include "netlink.h"
36
37 char batadv_routing_algo[20] = "BATMAN_IV";
38 static struct hlist_head batadv_algo_list;
39
40 /**
41 * batadv_algo_init() - Initialize batman-adv algorithm management data
42 * structures
43 */
batadv_algo_init(void)44 void batadv_algo_init(void)
45 {
46 INIT_HLIST_HEAD(&batadv_algo_list);
47 }
48
batadv_algo_get(char * name)49 static struct batadv_algo_ops *batadv_algo_get(char *name)
50 {
51 struct batadv_algo_ops *bat_algo_ops = NULL, *bat_algo_ops_tmp;
52
53 hlist_for_each_entry(bat_algo_ops_tmp, &batadv_algo_list, list) {
54 if (strcmp(bat_algo_ops_tmp->name, name) != 0)
55 continue;
56
57 bat_algo_ops = bat_algo_ops_tmp;
58 break;
59 }
60
61 return bat_algo_ops;
62 }
63
64 /**
65 * batadv_algo_register() - Register callbacks for a mesh algorithm
66 * @bat_algo_ops: mesh algorithm callbacks to add
67 *
68 * Return: 0 on success or negative error number in case of failure
69 */
batadv_algo_register(struct batadv_algo_ops * bat_algo_ops)70 int batadv_algo_register(struct batadv_algo_ops *bat_algo_ops)
71 {
72 struct batadv_algo_ops *bat_algo_ops_tmp;
73
74 bat_algo_ops_tmp = batadv_algo_get(bat_algo_ops->name);
75 if (bat_algo_ops_tmp) {
76 pr_info("Trying to register already registered routing algorithm: %s\n",
77 bat_algo_ops->name);
78 return -EEXIST;
79 }
80
81 /* all algorithms must implement all ops (for now) */
82 if (!bat_algo_ops->iface.enable ||
83 !bat_algo_ops->iface.disable ||
84 !bat_algo_ops->iface.update_mac ||
85 !bat_algo_ops->iface.primary_set ||
86 !bat_algo_ops->neigh.cmp ||
87 !bat_algo_ops->neigh.is_similar_or_better) {
88 pr_info("Routing algo '%s' does not implement required ops\n",
89 bat_algo_ops->name);
90 return -EINVAL;
91 }
92
93 INIT_HLIST_NODE(&bat_algo_ops->list);
94 hlist_add_head(&bat_algo_ops->list, &batadv_algo_list);
95
96 return 0;
97 }
98
99 /**
100 * batadv_algo_select() - Select algorithm of soft interface
101 * @bat_priv: the bat priv with all the soft interface information
102 * @name: name of the algorithm to select
103 *
104 * The algorithm callbacks for the soft interface will be set when the algorithm
105 * with the correct name was found. Any previous selected algorithm will not be
106 * deinitialized and the new selected algorithm will also not be initialized.
107 * It is therefore not allowed to call batadv_algo_select outside the creation
108 * function of the soft interface.
109 *
110 * Return: 0 on success or negative error number in case of failure
111 */
batadv_algo_select(struct batadv_priv * bat_priv,char * name)112 int batadv_algo_select(struct batadv_priv *bat_priv, char *name)
113 {
114 struct batadv_algo_ops *bat_algo_ops;
115
116 bat_algo_ops = batadv_algo_get(name);
117 if (!bat_algo_ops)
118 return -EINVAL;
119
120 bat_priv->algo_ops = bat_algo_ops;
121
122 return 0;
123 }
124
125 #ifdef CONFIG_BATMAN_ADV_DEBUGFS
126
127 /**
128 * batadv_algo_seq_print_text() - Print the supported algorithms in a seq file
129 * @seq: seq file to print on
130 * @offset: not used
131 *
132 * Return: always 0
133 */
batadv_algo_seq_print_text(struct seq_file * seq,void * offset)134 int batadv_algo_seq_print_text(struct seq_file *seq, void *offset)
135 {
136 struct batadv_algo_ops *bat_algo_ops;
137
138 seq_puts(seq, "Available routing algorithms:\n");
139
140 hlist_for_each_entry(bat_algo_ops, &batadv_algo_list, list) {
141 seq_printf(seq, " * %s\n", bat_algo_ops->name);
142 }
143
144 return 0;
145 }
146 #endif
147
batadv_param_set_ra(const char * val,const struct kernel_param * kp)148 static int batadv_param_set_ra(const char *val, const struct kernel_param *kp)
149 {
150 struct batadv_algo_ops *bat_algo_ops;
151 char *algo_name = (char *)val;
152 size_t name_len = strlen(algo_name);
153
154 if (name_len > 0 && algo_name[name_len - 1] == '\n')
155 algo_name[name_len - 1] = '\0';
156
157 bat_algo_ops = batadv_algo_get(algo_name);
158 if (!bat_algo_ops) {
159 pr_err("Routing algorithm '%s' is not supported\n", algo_name);
160 return -EINVAL;
161 }
162
163 return param_set_copystring(algo_name, kp);
164 }
165
166 static const struct kernel_param_ops batadv_param_ops_ra = {
167 .set = batadv_param_set_ra,
168 .get = param_get_string,
169 };
170
171 static struct kparam_string batadv_param_string_ra = {
172 .maxlen = sizeof(batadv_routing_algo),
173 .string = batadv_routing_algo,
174 };
175
176 module_param_cb(routing_algo, &batadv_param_ops_ra, &batadv_param_string_ra,
177 0644);
178
179 /**
180 * batadv_algo_dump_entry() - fill in information about one supported routing
181 * algorithm
182 * @msg: netlink message to be sent back
183 * @portid: Port to reply to
184 * @seq: Sequence number of message
185 * @bat_algo_ops: Algorithm to be dumped
186 *
187 * Return: Error number, or 0 on success
188 */
batadv_algo_dump_entry(struct sk_buff * msg,u32 portid,u32 seq,struct batadv_algo_ops * bat_algo_ops)189 static int batadv_algo_dump_entry(struct sk_buff *msg, u32 portid, u32 seq,
190 struct batadv_algo_ops *bat_algo_ops)
191 {
192 void *hdr;
193
194 hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family,
195 NLM_F_MULTI, BATADV_CMD_GET_ROUTING_ALGOS);
196 if (!hdr)
197 return -EMSGSIZE;
198
199 if (nla_put_string(msg, BATADV_ATTR_ALGO_NAME, bat_algo_ops->name))
200 goto nla_put_failure;
201
202 genlmsg_end(msg, hdr);
203 return 0;
204
205 nla_put_failure:
206 genlmsg_cancel(msg, hdr);
207 return -EMSGSIZE;
208 }
209
210 /**
211 * batadv_algo_dump() - fill in information about supported routing
212 * algorithms
213 * @msg: netlink message to be sent back
214 * @cb: Parameters to the netlink request
215 *
216 * Return: Length of reply message.
217 */
batadv_algo_dump(struct sk_buff * msg,struct netlink_callback * cb)218 int batadv_algo_dump(struct sk_buff *msg, struct netlink_callback *cb)
219 {
220 int portid = NETLINK_CB(cb->skb).portid;
221 struct batadv_algo_ops *bat_algo_ops;
222 int skip = cb->args[0];
223 int i = 0;
224
225 hlist_for_each_entry(bat_algo_ops, &batadv_algo_list, list) {
226 if (i++ < skip)
227 continue;
228
229 if (batadv_algo_dump_entry(msg, portid, cb->nlh->nlmsg_seq,
230 bat_algo_ops)) {
231 i--;
232 break;
233 }
234 }
235
236 cb->args[0] = i;
237
238 return msg->len;
239 }
240
