linux/net/core/dev_ioctl.c
Daniel Borkmann e020836d95 dev_ioctl: remove dev_load() CAP_SYS_MODULE message
Marcel reported to see the following message when autoloading
is being triggered when adding nlmon device:

  Loading kernel module for a network device with
  CAP_SYS_MODULE (deprecated). Use CAP_NET_ADMIN and alias
  netdev-nlmon instead.

This false-positive happens despite with having correct
capabilities set, e.g. through issuing `ip link del dev nlmon`
more than once on a valid device with name nlmon, but Marcel
has also seen it on creation time when no nlmon module is
previously compiled-in or loaded as module and the device
name equals a link type name (e.g. nlmon, vxlan, team).

Stephen says:

  The netdev module alias is a hold over from the past. For
  normal devices, people used to create a alias eth0 to and
  point it to the type of network device used, that was back
  in the bad old ISA days before real discovery.

  Also, the tunnels create module alias for the control device
  and ip used to use this to autoload the tunnel device.

  The message is bogus and should just be removed, I also see
  it in a couple of other cases where tap devices are renamed
  for other usese.

As mentioned in 8909c9ad8f ("net: don't allow CAP_NET_ADMIN
to load non-netdev kernel modules"), we nevertheless still
might want to leave the old autoloading behaviour in place
as it could break old scripts, so for now, lets just remove
the log message as Stephen suggests.

Reference: http://thread.gmane.org/gmane.linux.kernel/1105168
Reported-by: Marcel Holtmann <marcel@holtmann.org>
Suggested-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-05 12:04:40 -07:00

565 lines
13 KiB
C

#include <linux/kmod.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/rtnetlink.h>
#include <linux/net_tstamp.h>
#include <linux/wireless.h>
#include <net/wext.h>
/*
* Map an interface index to its name (SIOCGIFNAME)
*/
/*
* We need this ioctl for efficient implementation of the
* if_indextoname() function required by the IPv6 API. Without
* it, we would have to search all the interfaces to find a
* match. --pb
*/
static int dev_ifname(struct net *net, struct ifreq __user *arg)
{
struct ifreq ifr;
int error;
/*
* Fetch the caller's info block.
*/
if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
return -EFAULT;
error = netdev_get_name(net, ifr.ifr_name, ifr.ifr_ifindex);
if (error)
return error;
if (copy_to_user(arg, &ifr, sizeof(struct ifreq)))
return -EFAULT;
return 0;
}
static gifconf_func_t *gifconf_list[NPROTO];
/**
* register_gifconf - register a SIOCGIF handler
* @family: Address family
* @gifconf: Function handler
*
* Register protocol dependent address dumping routines. The handler
* that is passed must not be freed or reused until it has been replaced
* by another handler.
*/
int register_gifconf(unsigned int family, gifconf_func_t *gifconf)
{
if (family >= NPROTO)
return -EINVAL;
gifconf_list[family] = gifconf;
return 0;
}
EXPORT_SYMBOL(register_gifconf);
/*
* Perform a SIOCGIFCONF call. This structure will change
* size eventually, and there is nothing I can do about it.
* Thus we will need a 'compatibility mode'.
*/
static int dev_ifconf(struct net *net, char __user *arg)
{
struct ifconf ifc;
struct net_device *dev;
char __user *pos;
int len;
int total;
int i;
/*
* Fetch the caller's info block.
*/
if (copy_from_user(&ifc, arg, sizeof(struct ifconf)))
return -EFAULT;
pos = ifc.ifc_buf;
len = ifc.ifc_len;
/*
* Loop over the interfaces, and write an info block for each.
*/
total = 0;
for_each_netdev(net, dev) {
for (i = 0; i < NPROTO; i++) {
if (gifconf_list[i]) {
int done;
if (!pos)
done = gifconf_list[i](dev, NULL, 0);
else
done = gifconf_list[i](dev, pos + total,
len - total);
if (done < 0)
return -EFAULT;
total += done;
}
}
}
/*
* All done. Write the updated control block back to the caller.
*/
ifc.ifc_len = total;
/*
* Both BSD and Solaris return 0 here, so we do too.
*/
return copy_to_user(arg, &ifc, sizeof(struct ifconf)) ? -EFAULT : 0;
}
/*
* Perform the SIOCxIFxxx calls, inside rcu_read_lock()
*/
static int dev_ifsioc_locked(struct net *net, struct ifreq *ifr, unsigned int cmd)
{
int err;
struct net_device *dev = dev_get_by_name_rcu(net, ifr->ifr_name);
if (!dev)
return -ENODEV;
switch (cmd) {
case SIOCGIFFLAGS: /* Get interface flags */
ifr->ifr_flags = (short) dev_get_flags(dev);
return 0;
case SIOCGIFMETRIC: /* Get the metric on the interface
(currently unused) */
ifr->ifr_metric = 0;
return 0;
case SIOCGIFMTU: /* Get the MTU of a device */
ifr->ifr_mtu = dev->mtu;
return 0;
case SIOCGIFHWADDR:
if (!dev->addr_len)
memset(ifr->ifr_hwaddr.sa_data, 0, sizeof ifr->ifr_hwaddr.sa_data);
else
memcpy(ifr->ifr_hwaddr.sa_data, dev->dev_addr,
min(sizeof ifr->ifr_hwaddr.sa_data, (size_t) dev->addr_len));
ifr->ifr_hwaddr.sa_family = dev->type;
return 0;
case SIOCGIFSLAVE:
err = -EINVAL;
break;
case SIOCGIFMAP:
ifr->ifr_map.mem_start = dev->mem_start;
ifr->ifr_map.mem_end = dev->mem_end;
ifr->ifr_map.base_addr = dev->base_addr;
ifr->ifr_map.irq = dev->irq;
ifr->ifr_map.dma = dev->dma;
ifr->ifr_map.port = dev->if_port;
return 0;
case SIOCGIFINDEX:
ifr->ifr_ifindex = dev->ifindex;
return 0;
case SIOCGIFTXQLEN:
ifr->ifr_qlen = dev->tx_queue_len;
return 0;
default:
/* dev_ioctl() should ensure this case
* is never reached
*/
WARN_ON(1);
err = -ENOTTY;
break;
}
return err;
}
static int net_hwtstamp_validate(struct ifreq *ifr)
{
struct hwtstamp_config cfg;
enum hwtstamp_tx_types tx_type;
enum hwtstamp_rx_filters rx_filter;
int tx_type_valid = 0;
int rx_filter_valid = 0;
if (copy_from_user(&cfg, ifr->ifr_data, sizeof(cfg)))
return -EFAULT;
if (cfg.flags) /* reserved for future extensions */
return -EINVAL;
tx_type = cfg.tx_type;
rx_filter = cfg.rx_filter;
switch (tx_type) {
case HWTSTAMP_TX_OFF:
case HWTSTAMP_TX_ON:
case HWTSTAMP_TX_ONESTEP_SYNC:
tx_type_valid = 1;
break;
}
switch (rx_filter) {
case HWTSTAMP_FILTER_NONE:
case HWTSTAMP_FILTER_ALL:
case HWTSTAMP_FILTER_SOME:
case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
case HWTSTAMP_FILTER_PTP_V2_EVENT:
case HWTSTAMP_FILTER_PTP_V2_SYNC:
case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
rx_filter_valid = 1;
break;
}
if (!tx_type_valid || !rx_filter_valid)
return -ERANGE;
return 0;
}
/*
* Perform the SIOCxIFxxx calls, inside rtnl_lock()
*/
static int dev_ifsioc(struct net *net, struct ifreq *ifr, unsigned int cmd)
{
int err;
struct net_device *dev = __dev_get_by_name(net, ifr->ifr_name);
const struct net_device_ops *ops;
if (!dev)
return -ENODEV;
ops = dev->netdev_ops;
switch (cmd) {
case SIOCSIFFLAGS: /* Set interface flags */
return dev_change_flags(dev, ifr->ifr_flags);
case SIOCSIFMETRIC: /* Set the metric on the interface
(currently unused) */
return -EOPNOTSUPP;
case SIOCSIFMTU: /* Set the MTU of a device */
return dev_set_mtu(dev, ifr->ifr_mtu);
case SIOCSIFHWADDR:
return dev_set_mac_address(dev, &ifr->ifr_hwaddr);
case SIOCSIFHWBROADCAST:
if (ifr->ifr_hwaddr.sa_family != dev->type)
return -EINVAL;
memcpy(dev->broadcast, ifr->ifr_hwaddr.sa_data,
min(sizeof ifr->ifr_hwaddr.sa_data, (size_t) dev->addr_len));
call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
return 0;
case SIOCSIFMAP:
if (ops->ndo_set_config) {
if (!netif_device_present(dev))
return -ENODEV;
return ops->ndo_set_config(dev, &ifr->ifr_map);
}
return -EOPNOTSUPP;
case SIOCADDMULTI:
if (!ops->ndo_set_rx_mode ||
ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
return -EINVAL;
if (!netif_device_present(dev))
return -ENODEV;
return dev_mc_add_global(dev, ifr->ifr_hwaddr.sa_data);
case SIOCDELMULTI:
if (!ops->ndo_set_rx_mode ||
ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
return -EINVAL;
if (!netif_device_present(dev))
return -ENODEV;
return dev_mc_del_global(dev, ifr->ifr_hwaddr.sa_data);
case SIOCSIFTXQLEN:
if (ifr->ifr_qlen < 0)
return -EINVAL;
dev->tx_queue_len = ifr->ifr_qlen;
return 0;
case SIOCSIFNAME:
ifr->ifr_newname[IFNAMSIZ-1] = '\0';
return dev_change_name(dev, ifr->ifr_newname);
case SIOCSHWTSTAMP:
err = net_hwtstamp_validate(ifr);
if (err)
return err;
/* fall through */
/*
* Unknown or private ioctl
*/
default:
if ((cmd >= SIOCDEVPRIVATE &&
cmd <= SIOCDEVPRIVATE + 15) ||
cmd == SIOCBONDENSLAVE ||
cmd == SIOCBONDRELEASE ||
cmd == SIOCBONDSETHWADDR ||
cmd == SIOCBONDSLAVEINFOQUERY ||
cmd == SIOCBONDINFOQUERY ||
cmd == SIOCBONDCHANGEACTIVE ||
cmd == SIOCGMIIPHY ||
cmd == SIOCGMIIREG ||
cmd == SIOCSMIIREG ||
cmd == SIOCBRADDIF ||
cmd == SIOCBRDELIF ||
cmd == SIOCSHWTSTAMP ||
cmd == SIOCGHWTSTAMP ||
cmd == SIOCWANDEV) {
err = -EOPNOTSUPP;
if (ops->ndo_do_ioctl) {
if (netif_device_present(dev))
err = ops->ndo_do_ioctl(dev, ifr, cmd);
else
err = -ENODEV;
}
} else
err = -EINVAL;
}
return err;
}
/**
* dev_load - load a network module
* @net: the applicable net namespace
* @name: name of interface
*
* If a network interface is not present and the process has suitable
* privileges this function loads the module. If module loading is not
* available in this kernel then it becomes a nop.
*/
void dev_load(struct net *net, const char *name)
{
struct net_device *dev;
int no_module;
rcu_read_lock();
dev = dev_get_by_name_rcu(net, name);
rcu_read_unlock();
no_module = !dev;
if (no_module && capable(CAP_NET_ADMIN))
no_module = request_module("netdev-%s", name);
if (no_module && capable(CAP_SYS_MODULE))
request_module("%s", name);
}
EXPORT_SYMBOL(dev_load);
/*
* This function handles all "interface"-type I/O control requests. The actual
* 'doing' part of this is dev_ifsioc above.
*/
/**
* dev_ioctl - network device ioctl
* @net: the applicable net namespace
* @cmd: command to issue
* @arg: pointer to a struct ifreq in user space
*
* Issue ioctl functions to devices. This is normally called by the
* user space syscall interfaces but can sometimes be useful for
* other purposes. The return value is the return from the syscall if
* positive or a negative errno code on error.
*/
int dev_ioctl(struct net *net, unsigned int cmd, void __user *arg)
{
struct ifreq ifr;
int ret;
char *colon;
/* One special case: SIOCGIFCONF takes ifconf argument
and requires shared lock, because it sleeps writing
to user space.
*/
if (cmd == SIOCGIFCONF) {
rtnl_lock();
ret = dev_ifconf(net, (char __user *) arg);
rtnl_unlock();
return ret;
}
if (cmd == SIOCGIFNAME)
return dev_ifname(net, (struct ifreq __user *)arg);
if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
return -EFAULT;
ifr.ifr_name[IFNAMSIZ-1] = 0;
colon = strchr(ifr.ifr_name, ':');
if (colon)
*colon = 0;
/*
* See which interface the caller is talking about.
*/
switch (cmd) {
/*
* These ioctl calls:
* - can be done by all.
* - atomic and do not require locking.
* - return a value
*/
case SIOCGIFFLAGS:
case SIOCGIFMETRIC:
case SIOCGIFMTU:
case SIOCGIFHWADDR:
case SIOCGIFSLAVE:
case SIOCGIFMAP:
case SIOCGIFINDEX:
case SIOCGIFTXQLEN:
dev_load(net, ifr.ifr_name);
rcu_read_lock();
ret = dev_ifsioc_locked(net, &ifr, cmd);
rcu_read_unlock();
if (!ret) {
if (colon)
*colon = ':';
if (copy_to_user(arg, &ifr,
sizeof(struct ifreq)))
ret = -EFAULT;
}
return ret;
case SIOCETHTOOL:
dev_load(net, ifr.ifr_name);
rtnl_lock();
ret = dev_ethtool(net, &ifr);
rtnl_unlock();
if (!ret) {
if (colon)
*colon = ':';
if (copy_to_user(arg, &ifr,
sizeof(struct ifreq)))
ret = -EFAULT;
}
return ret;
/*
* These ioctl calls:
* - require superuser power.
* - require strict serialization.
* - return a value
*/
case SIOCGMIIPHY:
case SIOCGMIIREG:
case SIOCSIFNAME:
if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
return -EPERM;
dev_load(net, ifr.ifr_name);
rtnl_lock();
ret = dev_ifsioc(net, &ifr, cmd);
rtnl_unlock();
if (!ret) {
if (colon)
*colon = ':';
if (copy_to_user(arg, &ifr,
sizeof(struct ifreq)))
ret = -EFAULT;
}
return ret;
/*
* These ioctl calls:
* - require superuser power.
* - require strict serialization.
* - do not return a value
*/
case SIOCSIFMAP:
case SIOCSIFTXQLEN:
if (!capable(CAP_NET_ADMIN))
return -EPERM;
/* fall through */
/*
* These ioctl calls:
* - require local superuser power.
* - require strict serialization.
* - do not return a value
*/
case SIOCSIFFLAGS:
case SIOCSIFMETRIC:
case SIOCSIFMTU:
case SIOCSIFHWADDR:
case SIOCSIFSLAVE:
case SIOCADDMULTI:
case SIOCDELMULTI:
case SIOCSIFHWBROADCAST:
case SIOCSMIIREG:
case SIOCBONDENSLAVE:
case SIOCBONDRELEASE:
case SIOCBONDSETHWADDR:
case SIOCBONDCHANGEACTIVE:
case SIOCBRADDIF:
case SIOCBRDELIF:
case SIOCSHWTSTAMP:
if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
return -EPERM;
/* fall through */
case SIOCBONDSLAVEINFOQUERY:
case SIOCBONDINFOQUERY:
dev_load(net, ifr.ifr_name);
rtnl_lock();
ret = dev_ifsioc(net, &ifr, cmd);
rtnl_unlock();
return ret;
case SIOCGIFMEM:
/* Get the per device memory space. We can add this but
* currently do not support it */
case SIOCSIFMEM:
/* Set the per device memory buffer space.
* Not applicable in our case */
case SIOCSIFLINK:
return -ENOTTY;
/*
* Unknown or private ioctl.
*/
default:
if (cmd == SIOCWANDEV ||
cmd == SIOCGHWTSTAMP ||
(cmd >= SIOCDEVPRIVATE &&
cmd <= SIOCDEVPRIVATE + 15)) {
dev_load(net, ifr.ifr_name);
rtnl_lock();
ret = dev_ifsioc(net, &ifr, cmd);
rtnl_unlock();
if (!ret && copy_to_user(arg, &ifr,
sizeof(struct ifreq)))
ret = -EFAULT;
return ret;
}
/* Take care of Wireless Extensions */
if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST)
return wext_handle_ioctl(net, &ifr, cmd, arg);
return -ENOTTY;
}
}