// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Ioctl handler
* Linux ethernet bridge
*
* Authors:
* Lennert Buytenhek <[email protected]>
*/
#include <linux/capability.h>
#include <linux/compat.h>
#include <linux/kernel.h>
#include <linux/if_bridge.h>
#include <linux/netdevice.h>
#include <linux/slab.h>
#include <linux/times.h>
#include <net/net_namespace.h>
#include <linux/uaccess.h>
#include "br_private.h"
static int get_bridge_ifindices(struct net *net, int *indices, int num)
{
struct net_device *dev;
int i = 0;
rcu_read_lock();
for_each_netdev_rcu(net, dev) {
if (i >= num)
break;
if (netif_is_bridge_master(dev))
indices[i++] = dev->ifindex;
}
rcu_read_unlock();
return i;
}
/* called with RTNL */
static void get_port_ifindices(struct net_bridge *br, int *ifindices, int num)
{
struct net_bridge_port *p;
list_for_each_entry(p, &br->port_list, list) {
if (p->port_no < num)
ifindices[p->port_no] = p->dev->ifindex;
}
}
/*
* Format up to a page worth of forwarding table entries
* userbuf -- where to copy result
* maxnum -- maximum number of entries desired
* (limited to a page for sanity)
* offset -- number of records to skip
*/
static int get_fdb_entries(struct net_bridge *br, void __user *userbuf,
unsigned long maxnum, unsigned long offset)
{
int num;
void *buf;
size_t size;
/* Clamp size to PAGE_SIZE, test maxnum to avoid overflow */
if (maxnum > PAGE_SIZE/sizeof(struct __fdb_entry))
maxnum = PAGE_SIZE/sizeof(struct __fdb_entry);
size = maxnum * sizeof(struct __fdb_entry);
buf = kmalloc(size, GFP_USER);
if (!buf)
return -ENOMEM;
num = br_fdb_fillbuf(br, buf, maxnum, offset);
if (num > 0) {
if (copy_to_user(userbuf, buf,
array_size(num, sizeof(struct __fdb_entry))))
num = -EFAULT;
}
kfree(buf);
return num;
}
/* called with RTNL */
static int add_del_if(struct net_bridge *br, int ifindex, int isadd)
{
struct net *net = dev_net(br->dev);
struct net_device *dev;
int ret;
if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
return -EPERM;
dev = __dev_get_by_index(net, ifindex);
if (dev == NULL)
return -EINVAL;
if (isadd)
ret = br_add_if(br, dev, NULL);
else
ret = br_del_if(br, dev);
return ret;
}
#define BR_UARGS_MAX 4
static int br_dev_read_uargs(unsigned long *args, size_t nr_args,
void __user **argp, void __user *data)
{
int ret;
if (nr_args < 2 || nr_args > BR_UARGS_MAX)
return -EINVAL;
if (in_compat_syscall()) {
unsigned int cargs[BR_UARGS_MAX];
int i;
ret = copy_from_user(cargs, data, nr_args * sizeof(*cargs));
if (ret)
goto fault;
for (i = 0; i < nr_args; ++i)
args[i] = cargs[i];
*argp = compat_ptr(args[1]);
} else {
ret = copy_from_user(args, data, nr_args * sizeof(*args));
if (ret)
goto fault;
*argp = (void __user *)args[1];
}
return 0;
fault:
return -EFAULT;
}
/*
* Legacy ioctl's through SIOCDEVPRIVATE
* This interface is deprecated because it was too difficult
* to do the translation for 32/64bit ioctl compatibility.
*/
int br_dev_siocdevprivate(struct net_device *dev, struct ifreq *rq,
void __user *data, int cmd)
{
struct net_bridge *br = netdev_priv(dev);
struct net_bridge_port *p = NULL;
unsigned long args[4];
void __user *argp;
int ret;
ret = br_dev_read_uargs(args, ARRAY_SIZE(args), &argp, data);
if (ret)
return ret;
switch (args[0]) {
case BRCTL_ADD_IF:
case BRCTL_DEL_IF:
return add_del_if(br, args[1], args[0] == BRCTL_ADD_IF);
case BRCTL_GET_BRIDGE_INFO:
{
struct __bridge_info b;
memset(&b, 0, sizeof(struct __bridge_info));
rcu_read_lock();
memcpy(&b.designated_root, &br->designated_root, 8);
memcpy(&b.bridge_id, &br->bridge_id, 8);
b.root_path_cost = br->root_path_cost;
b.max_age = jiffies_to_clock_t(br->max_age);
b.hello_time = jiffies_to_clock_t(br->hello_time);
b.forward_delay = br->forward_delay;
b.bridge_max_age = br->bridge_max_age;
b.bridge_hello_time = br->bridge_hello_time;
b.bridge_forward_delay = jiffies_to_clock_t(br->bridge_forward_delay);
b.topology_change = br->topology_change;
b.topology_change_detected = br->topology_change_detected;
b.root_port = br->root_port;
b.stp_enabled = (br->stp_enabled != BR_NO_STP);
b.ageing_time = jiffies_to_clock_t(br->ageing_time);
b.hello_timer_value = br_timer_value(&br->hello_timer);
b.tcn_timer_value = br_timer_value(&br->tcn_timer);
b.topology_change_timer_value = br_timer_value(&br->topology_change_timer);
b.gc_timer_value = br_timer_value(&br->gc_work.timer);
rcu_read_unlock();
if (copy_to_user((void __user *)args[1], &b, sizeof(b)))
return -EFAULT;
return 0;
}
case BRCTL_GET_PORT_LIST:
{
int num, *indices;
num = args[2];
if (num < 0)
return -EINVAL;
if (num == 0)
num = 256;
if (num > BR_MAX_PORTS)
num = BR_MAX_PORTS;
indices = kcalloc(num, sizeof(int), GFP_KERNEL);
if (indices == NULL)
return -ENOMEM;
get_port_ifindices(br, indices, num);
if (copy_to_user(argp, indices, array_size(num, sizeof(int))))
num = -EFAULT;
kfree(indices);
return num;
}
case BRCTL_SET_BRIDGE_FORWARD_DELAY:
if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
return -EPERM;
ret = br_set_forward_delay(br, args[1]);
break;
case BRCTL_SET_BRIDGE_HELLO_TIME:
if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
return -EPERM;
ret = br_set_hello_time(br, args[1]);
break;
case BRCTL_SET_BRIDGE_MAX_AGE:
if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
return -EPERM;
ret = br_set_max_age(br, args[1]);
break;
case BRCTL_SET_AGEING_TIME:
if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
return -EPERM;
ret = br_set_ageing_time(br, args[1]);
break;
case BRCTL_GET_PORT_INFO:
{
struct __port_info p;
struct net_bridge_port *pt;
rcu_read_lock();
if ((pt = br_get_port(br, args[2])) == NULL) {
rcu_read_unlock();
return -EINVAL;
}
memset(&p, 0, sizeof(struct __port_info));
memcpy(&p.designated_root, &pt->designated_root, 8);
memcpy(&p.designated_bridge, &pt->designated_bridge, 8);
p.port_id = pt->port_id;
p.designated_port = pt->designated_port;
p.path_cost = pt->path_cost;
p.designated_cost = pt->designated_cost;
p.state = pt->state;
p.top_change_ack = pt->topology_change_ack;
p.config_pending = pt->config_pending;
p.message_age_timer_value = br_timer_value(&pt->message_age_timer);
p.forward_delay_timer_value = br_timer_value(&pt->forward_delay_timer);
p.hold_timer_value = br_timer_value(&pt->hold_timer);
rcu_read_unlock();
if (copy_to_user(argp, &p, sizeof(p)))
return -EFAULT;
return 0;
}
case BRCTL_SET_BRIDGE_STP_STATE:
if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
return -EPERM;
ret = br_stp_set_enabled(br, args[1], NULL);
break;
case BRCTL_SET_BRIDGE_PRIORITY:
if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
return -EPERM;
br_stp_set_bridge_priority(br, args[1]);
ret = 0;
break;
case BRCTL_SET_PORT_PRIORITY:
{
if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
return -EPERM;
spin_lock_bh(&br->lock);
if ((p = br_get_port(br, args[1])) == NULL)
ret = -EINVAL;
else
ret = br_stp_set_port_priority(p, args[2]);
spin_unlock_bh(&br->lock);
break;
}
case BRCTL_SET_PATH_COST:
{
if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
return -EPERM;
spin_lock_bh(&br->lock);
if ((p = br_get_port(br, args[1])) == NULL)
ret = -EINVAL;
else
ret = br_stp_set_path_cost(p, args[2]);
spin_unlock_bh(&br->lock);
break;
}
case BRCTL_GET_FDB_ENTRIES:
return get_fdb_entries(br, argp, args[2], args[3]);
default:
ret = -EOPNOTSUPP;
}
if (!ret) {
if (p)
br_ifinfo_notify(RTM_NEWLINK, NULL, p);
else
netdev_state_change(br->dev);
}
return ret;
}
static int old_deviceless(struct net *net, void __user *data)
{
unsigned long args[3];
void __user *argp;
int ret;
ret = br_dev_read_uargs(args, ARRAY_SIZE(args), &argp, data);
if (ret)
return ret;
switch (args[0]) {
case BRCTL_GET_VERSION:
return BRCTL_VERSION;
case BRCTL_GET_BRIDGES:
{
int *indices;
int ret = 0;
if (args[2] >= 2048)
return -ENOMEM;
indices = kcalloc(args[2], sizeof(int), GFP_KERNEL);
if (indices == NULL)
return -ENOMEM;
args[2] = get_bridge_ifindices(net, indices, args[2]);
ret = copy_to_user(argp, indices,
array_size(args[2], sizeof(int)))
? -EFAULT : args[2];
kfree(indices);
return ret;
}
case BRCTL_ADD_BRIDGE:
case BRCTL_DEL_BRIDGE:
{
char buf[IFNAMSIZ];
if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
return -EPERM;
if (copy_from_user(buf, argp, IFNAMSIZ))
return -EFAULT;
buf[IFNAMSIZ-1] = 0;
if (args[0] == BRCTL_ADD_BRIDGE)
return br_add_bridge(net, buf);
return br_del_bridge(net, buf);
}
}
return -EOPNOTSUPP;
}
int br_ioctl_stub(struct net *net, struct net_bridge *br, unsigned int cmd,
struct ifreq *ifr, void __user *uarg)
{
int ret = -EOPNOTSUPP;
rtnl_lock();
switch (cmd) {
case SIOCGIFBR:
case SIOCSIFBR:
ret = old_deviceless(net, uarg);
break;
case SIOCBRADDBR:
case SIOCBRDELBR:
{
char buf[IFNAMSIZ];
if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) {
ret = -EPERM;
break;
}
if (copy_from_user(buf, uarg, IFNAMSIZ)) {
ret = -EFAULT;
break;
}
buf[IFNAMSIZ-1] = 0;
if (cmd == SIOCBRADDBR)
ret = br_add_bridge(net, buf);
else
ret = br_del_bridge(net, buf);
}
break;
case SIOCBRADDIF:
case SIOCBRDELIF:
ret = add_del_if(br, ifr->ifr_ifindex, cmd == SIOCBRADDIF);
break;
}
rtnl_unlock();
return ret;
}
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