1 /*
2  *	Userspace interface
3  *	Linux ethernet bridge
4  *
5  *	Authors:
6  *	Lennert Buytenhek		<buytenh@gnu.org>
7  *
8  *	$Id: br_if.c,v 1.6.2.1 2001/12/24 00:59:27 davem Exp $
9  *
10  *	This program is free software; you can redistribute it and/or
11  *	modify it under the terms of the GNU General Public License
12  *	as published by the Free Software Foundation; either version
13  *	2 of the License, or (at your option) any later version.
14  */
15 
16 #include <linux/kernel.h>
17 #include <linux/if_arp.h>
18 #include <linux/if_bridge.h>
19 #include <linux/inetdevice.h>
20 #include <linux/rtnetlink.h>
21 #include <linux/brlock.h>
22 #include <linux/etherdevice.h>
23 #include <asm/uaccess.h>
24 #include "br_private.h"
25 
br_initial_port_cost(struct net_device * dev)26 static int br_initial_port_cost(struct net_device *dev)
27 {
28 	if (!strncmp(dev->name, "lec", 3))
29 		return 7;
30 
31 	if (!strncmp(dev->name, "eth", 3))
32 		return 100;			/* FIXME handle 100Mbps */
33 
34 	if (!strncmp(dev->name, "plip", 4))
35 		return 2500;
36 
37 	return 100;
38 }
39 
40 /* called under BR_NETPROTO_LOCK and bridge lock */
__br_del_if(struct net_bridge * br,struct net_device * dev)41 static int __br_del_if(struct net_bridge *br, struct net_device *dev)
42 {
43 	struct net_bridge_port *p;
44 	struct net_bridge_port **pptr;
45 
46 	if ((p = dev->br_port) == NULL || p->br != br)
47 		return -EINVAL;
48 
49 	br_stp_disable_port(p);
50 
51 	dev_set_promiscuity(dev, -1);
52 	dev->br_port = NULL;
53 
54 	pptr = &br->port_list;
55 	while (*pptr != NULL) {
56 		if (*pptr == p) {
57 			*pptr = p->next;
58 			break;
59 		}
60 
61 		pptr = &((*pptr)->next);
62 	}
63 
64 	br_fdb_delete_by_port(br, p);
65 	kfree(p);
66 	dev_put(dev);
67 
68 	return 0;
69 }
70 
del_ifs(struct net_bridge * br)71 static void del_ifs(struct net_bridge *br)
72 {
73 	br_write_lock_bh(BR_NETPROTO_LOCK);
74 	write_lock(&br->lock);
75 	while (br->port_list != NULL)
76 		__br_del_if(br, br->port_list->dev);
77 	write_unlock(&br->lock);
78 	br_write_unlock_bh(BR_NETPROTO_LOCK);
79 }
80 
new_nb(char * name)81 static struct net_bridge *new_nb(char *name)
82 {
83 	struct net_bridge *br;
84 	struct net_device *dev;
85 
86 	if ((br = kmalloc(sizeof(*br), GFP_KERNEL)) == NULL)
87 		return NULL;
88 
89 	memset(br, 0, sizeof(*br));
90 	dev = &br->dev;
91 
92 	strncpy(dev->name, name, IFNAMSIZ);
93 	dev->priv = br;
94 	ether_setup(dev);
95 	br_dev_setup(dev);
96 
97 	br->lock = RW_LOCK_UNLOCKED;
98 	br->hash_lock = RW_LOCK_UNLOCKED;
99 
100 	br->bridge_id.prio[0] = 0x80;
101 	br->bridge_id.prio[1] = 0x00;
102 	memset(br->bridge_id.addr, 0, ETH_ALEN);
103 
104 	br->stp_enabled = 0;
105 	br->designated_root = br->bridge_id;
106 	br->root_path_cost = 0;
107 	br->root_port = 0;
108 	br->bridge_max_age = br->max_age = 20 * HZ;
109 	br->bridge_hello_time = br->hello_time = 2 * HZ;
110 	br->bridge_forward_delay = br->forward_delay = 15 * HZ;
111 	br->topology_change = 0;
112 	br->topology_change_detected = 0;
113 	br_timer_clear(&br->hello_timer);
114 	br_timer_clear(&br->tcn_timer);
115 	br_timer_clear(&br->topology_change_timer);
116 
117 	br->ageing_time = 300 * HZ;
118 	br->gc_interval = 4 * HZ;
119 
120 	return br;
121 }
122 
123 /* called under bridge lock */
new_nbp(struct net_bridge * br,struct net_device * dev)124 static struct net_bridge_port *new_nbp(struct net_bridge *br, struct net_device *dev)
125 {
126 	int i;
127 	struct net_bridge_port *p;
128 
129 	p = kmalloc(sizeof(*p), GFP_ATOMIC);
130 	if (p == NULL)
131 		return p;
132 
133 	memset(p, 0, sizeof(*p));
134 	p->br = br;
135 	p->dev = dev;
136 	p->path_cost = br_initial_port_cost(dev);
137 	p->priority = 0x80;
138 
139 	for (i=1;i<255;i++)
140 		if (br_get_port(br, i) == NULL)
141 			break;
142 
143 	if (i == 255) {
144 		kfree(p);
145 		return NULL;
146 	}
147 
148 	dev->br_port = p;
149 
150 	p->port_no = i;
151 	br_init_port(p);
152 	p->state = BR_STATE_DISABLED;
153 
154 	p->next = br->port_list;
155 	br->port_list = p;
156 
157 	return p;
158 }
159 
br_add_bridge(char * name)160 int br_add_bridge(char *name)
161 {
162 	struct net_bridge *br;
163 	struct net_device *dev;
164 	int err;
165 
166 	if ((br = new_nb(name)) == NULL)
167 		return -ENOMEM;
168 
169 	dev = &br->dev;
170 	if (strchr(dev->name, '%')) {
171 		err = dev_alloc_name(dev, dev->name);
172 		if (err < 0)
173 			goto  out;
174 	}
175 
176 	err = register_netdevice(dev);
177 	if (err == 0)
178 		br_inc_use_count();
179 
180  out:
181 	return err;
182 }
183 
br_del_bridge(char * name)184 int br_del_bridge(char *name)
185 {
186 	struct net_device *dev;
187 	struct net_bridge *br;
188 
189 	dev = __dev_get_by_name(name);
190 	if (!dev)
191 		return -ENXIO;
192 
193 	if (dev->hard_start_xmit != br_dev_xmit)
194 		return -EPERM;
195 
196 	if (dev->flags & IFF_UP)
197 		return -EBUSY;
198 
199 	br = dev->priv;
200 	BUG_ON(&br->dev != dev);
201 
202 	del_ifs(br);
203 
204 	unregister_netdevice(dev);
205 	kfree(br);
206 	br_dec_use_count();
207 
208 	return 0;
209 }
210 
br_add_if(struct net_bridge * br,struct net_device * dev)211 int br_add_if(struct net_bridge *br, struct net_device *dev)
212 {
213 	struct net_bridge_port *p;
214 
215 	if (dev->br_port != NULL)
216 		return -EBUSY;
217 
218 	if (dev->flags & IFF_LOOPBACK || dev->type != ARPHRD_ETHER)
219 		return -EINVAL;
220 
221 	if (dev->hard_start_xmit == br_dev_xmit)
222 		return -ELOOP;
223 
224 	if (!is_valid_ether_addr(dev->dev_addr))
225 		return -EADDRNOTAVAIL;
226 
227 	dev_hold(dev);
228 	write_lock_bh(&br->lock);
229 	if ((p = new_nbp(br, dev)) == NULL) {
230 		write_unlock_bh(&br->lock);
231 		dev_put(dev);
232 		return -EXFULL;
233 	}
234 
235 	dev_set_promiscuity(dev, 1);
236 
237 	br_stp_recalculate_bridge_id(br);
238 	br_fdb_insert(br, p, dev->dev_addr, 1);
239 	if ((br->dev.flags & IFF_UP) && (dev->flags & IFF_UP))
240 		br_stp_enable_port(p);
241 	write_unlock_bh(&br->lock);
242 
243 	return 0;
244 }
245 
br_del_if(struct net_bridge * br,struct net_device * dev)246 int br_del_if(struct net_bridge *br, struct net_device *dev)
247 {
248 	int retval;
249 
250 	br_write_lock_bh(BR_NETPROTO_LOCK);
251 	write_lock(&br->lock);
252 	retval = __br_del_if(br, dev);
253 	br_stp_recalculate_bridge_id(br);
254 	write_unlock(&br->lock);
255 	br_write_unlock_bh(BR_NETPROTO_LOCK);
256 
257 	return retval;
258 }
259 
br_get_bridge_ifindices(int * indices,int num)260 int br_get_bridge_ifindices(int *indices, int num)
261 {
262 	struct net_device *dev;
263 	int i = 0;
264 
265 	for (dev = dev_base; i < num && dev != NULL; dev = dev->next) {
266 		if (dev->hard_start_xmit == br_dev_xmit)
267 			indices[i++] = dev->ifindex;
268 	}
269 
270 	return i;
271 }
272 
273 /* called under ioctl_lock */
br_get_port_ifindices(struct net_bridge * br,int * ifindices)274 void br_get_port_ifindices(struct net_bridge *br, int *ifindices)
275 {
276 	struct net_bridge_port *p;
277 
278 	p = br->port_list;
279 	while (p != NULL) {
280 		ifindices[p->port_no] = p->dev->ifindex;
281 		p = p->next;
282 	}
283 }
284