xref: /linux/drivers/net/netdevsim/fib.c (revision a8b70ccf10e38775785d9cb12ead916474549f99)
1 /*
2  * Copyright (c) 2018 Cumulus Networks. All rights reserved.
3  * Copyright (c) 2018 David Ahern <dsa@cumulusnetworks.com>
4  *
5  * This software is licensed under the GNU General License Version 2,
6  * June 1991 as shown in the file COPYING in the top-level directory of this
7  * source tree.
8  *
9  * THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS"
10  * WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
11  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
12  * FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE
13  * OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME
14  * THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
15  */
16 
17 #include <net/fib_notifier.h>
18 #include <net/ip_fib.h>
19 #include <net/ip6_fib.h>
20 #include <net/fib_rules.h>
21 #include <net/netns/generic.h>
22 
23 #include "netdevsim.h"
24 
25 struct nsim_fib_entry {
26 	u64 max;
27 	u64 num;
28 };
29 
30 struct nsim_per_fib_data {
31 	struct nsim_fib_entry fib;
32 	struct nsim_fib_entry rules;
33 };
34 
35 struct nsim_fib_data {
36 	struct nsim_per_fib_data ipv4;
37 	struct nsim_per_fib_data ipv6;
38 };
39 
40 static unsigned int nsim_fib_net_id;
41 
42 u64 nsim_fib_get_val(struct net *net, enum nsim_resource_id res_id, bool max)
43 {
44 	struct nsim_fib_data *fib_data = net_generic(net, nsim_fib_net_id);
45 	struct nsim_fib_entry *entry;
46 
47 	switch (res_id) {
48 	case NSIM_RESOURCE_IPV4_FIB:
49 		entry = &fib_data->ipv4.fib;
50 		break;
51 	case NSIM_RESOURCE_IPV4_FIB_RULES:
52 		entry = &fib_data->ipv4.rules;
53 		break;
54 	case NSIM_RESOURCE_IPV6_FIB:
55 		entry = &fib_data->ipv6.fib;
56 		break;
57 	case NSIM_RESOURCE_IPV6_FIB_RULES:
58 		entry = &fib_data->ipv6.rules;
59 		break;
60 	default:
61 		return 0;
62 	}
63 
64 	return max ? entry->max : entry->num;
65 }
66 
67 int nsim_fib_set_max(struct net *net, enum nsim_resource_id res_id, u64 val)
68 {
69 	struct nsim_fib_data *fib_data = net_generic(net, nsim_fib_net_id);
70 	struct nsim_fib_entry *entry;
71 	int err = 0;
72 
73 	switch (res_id) {
74 	case NSIM_RESOURCE_IPV4_FIB:
75 		entry = &fib_data->ipv4.fib;
76 		break;
77 	case NSIM_RESOURCE_IPV4_FIB_RULES:
78 		entry = &fib_data->ipv4.rules;
79 		break;
80 	case NSIM_RESOURCE_IPV6_FIB:
81 		entry = &fib_data->ipv6.fib;
82 		break;
83 	case NSIM_RESOURCE_IPV6_FIB_RULES:
84 		entry = &fib_data->ipv6.rules;
85 		break;
86 	default:
87 		return 0;
88 	}
89 
90 	/* not allowing a new max to be less than curren occupancy
91 	 * --> no means of evicting entries
92 	 */
93 	if (val < entry->num)
94 		err = -EINVAL;
95 	else
96 		entry->max = val;
97 
98 	return err;
99 }
100 
101 static int nsim_fib_rule_account(struct nsim_fib_entry *entry, bool add,
102 				 struct netlink_ext_ack *extack)
103 {
104 	int err = 0;
105 
106 	if (add) {
107 		if (entry->num < entry->max) {
108 			entry->num++;
109 		} else {
110 			err = -ENOSPC;
111 			NL_SET_ERR_MSG_MOD(extack, "Exceeded number of supported fib rule entries");
112 		}
113 	} else {
114 		entry->num--;
115 	}
116 
117 	return err;
118 }
119 
120 static int nsim_fib_rule_event(struct fib_notifier_info *info, bool add)
121 {
122 	struct nsim_fib_data *data = net_generic(info->net, nsim_fib_net_id);
123 	struct netlink_ext_ack *extack = info->extack;
124 	int err = 0;
125 
126 	switch (info->family) {
127 	case AF_INET:
128 		err = nsim_fib_rule_account(&data->ipv4.rules, add, extack);
129 		break;
130 	case AF_INET6:
131 		err = nsim_fib_rule_account(&data->ipv6.rules, add, extack);
132 		break;
133 	}
134 
135 	return err;
136 }
137 
138 static int nsim_fib_account(struct nsim_fib_entry *entry, bool add,
139 			    struct netlink_ext_ack *extack)
140 {
141 	int err = 0;
142 
143 	if (add) {
144 		if (entry->num < entry->max) {
145 			entry->num++;
146 		} else {
147 			err = -ENOSPC;
148 			NL_SET_ERR_MSG_MOD(extack, "Exceeded number of supported fib entries");
149 		}
150 	} else {
151 		entry->num--;
152 	}
153 
154 	return err;
155 }
156 
157 static int nsim_fib_event(struct fib_notifier_info *info, bool add)
158 {
159 	struct nsim_fib_data *data = net_generic(info->net, nsim_fib_net_id);
160 	struct netlink_ext_ack *extack = info->extack;
161 	int err = 0;
162 
163 	switch (info->family) {
164 	case AF_INET:
165 		err = nsim_fib_account(&data->ipv4.fib, add, extack);
166 		break;
167 	case AF_INET6:
168 		err = nsim_fib_account(&data->ipv6.fib, add, extack);
169 		break;
170 	}
171 
172 	return err;
173 }
174 
175 static int nsim_fib_event_nb(struct notifier_block *nb, unsigned long event,
176 			     void *ptr)
177 {
178 	struct fib_notifier_info *info = ptr;
179 	int err = 0;
180 
181 	switch (event) {
182 	case FIB_EVENT_RULE_ADD: /* fall through */
183 	case FIB_EVENT_RULE_DEL:
184 		err = nsim_fib_rule_event(info, event == FIB_EVENT_RULE_ADD);
185 		break;
186 
187 	case FIB_EVENT_ENTRY_ADD:  /* fall through */
188 	case FIB_EVENT_ENTRY_DEL:
189 		err = nsim_fib_event(info, event == FIB_EVENT_ENTRY_ADD);
190 		break;
191 	}
192 
193 	return notifier_from_errno(err);
194 }
195 
196 /* inconsistent dump, trying again */
197 static void nsim_fib_dump_inconsistent(struct notifier_block *nb)
198 {
199 	struct nsim_fib_data *data;
200 	struct net *net;
201 
202 	rcu_read_lock();
203 	for_each_net_rcu(net) {
204 		data = net_generic(net, nsim_fib_net_id);
205 
206 		data->ipv4.fib.num = 0ULL;
207 		data->ipv4.rules.num = 0ULL;
208 
209 		data->ipv6.fib.num = 0ULL;
210 		data->ipv6.rules.num = 0ULL;
211 	}
212 	rcu_read_unlock();
213 }
214 
215 static struct notifier_block nsim_fib_nb = {
216 	.notifier_call = nsim_fib_event_nb,
217 };
218 
219 /* Initialize per network namespace state */
220 static int __net_init nsim_fib_netns_init(struct net *net)
221 {
222 	struct nsim_fib_data *data = net_generic(net, nsim_fib_net_id);
223 
224 	data->ipv4.fib.max = (u64)-1;
225 	data->ipv4.rules.max = (u64)-1;
226 
227 	data->ipv6.fib.max = (u64)-1;
228 	data->ipv6.rules.max = (u64)-1;
229 
230 	return 0;
231 }
232 
233 static struct pernet_operations nsim_fib_net_ops = {
234 	.init = nsim_fib_netns_init,
235 	.id   = &nsim_fib_net_id,
236 	.size = sizeof(struct nsim_fib_data),
237 };
238 
239 void nsim_fib_exit(void)
240 {
241 	unregister_pernet_subsys(&nsim_fib_net_ops);
242 	unregister_fib_notifier(&nsim_fib_nb);
243 }
244 
245 int nsim_fib_init(void)
246 {
247 	int err;
248 
249 	err = register_pernet_subsys(&nsim_fib_net_ops);
250 	if (err < 0) {
251 		pr_err("Failed to register pernet subsystem\n");
252 		goto err_out;
253 	}
254 
255 	err = register_fib_notifier(&nsim_fib_nb, nsim_fib_dump_inconsistent);
256 	if (err < 0) {
257 		pr_err("Failed to register fib notifier\n");
258 		goto err_out;
259 	}
260 
261 err_out:
262 	return err;
263 }
264