/*
* Changes:
*
- * Brian Braunstein <linuxkernel@bristyle.com> 2007/03/23
- * Fixed hw address handling. Now net_device.dev_addr is kept consistent
- * with tun.dev_addr when the address is set by this module.
- *
* Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
* Add TUNSETLINK ioctl to set the link encapsulation
*
* Mark Smith <markzzzsmith@yahoo.com.au>
- * Use random_ether_addr() for tap MAC address.
+ * Use random_ether_addr() for tap MAC address.
*
* Harald Roelle <harald.roelle@ifi.lmu.de> 2004/04/20
* Fixes in packet dropping, queue length setting and queue wakeup.
#define DBG1( a... )
#endif
+#define FLT_EXACT_COUNT 8
+struct tap_filter {
+ unsigned int count; /* Number of addrs. Zero means disabled */
+ u32 mask[2]; /* Mask of the hashed addrs */
+ unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
+};
+
struct tun_struct {
struct list_head list;
- unsigned long flags;
+ unsigned int flags;
int attached;
uid_t owner;
gid_t group;
struct sk_buff_head readq;
struct net_device *dev;
+ struct fasync_struct *fasync;
- struct fasync_struct *fasync;
-
- unsigned long if_flags;
- u8 dev_addr[ETH_ALEN];
- u32 chr_filter[2];
- u32 net_filter[2];
+ struct tap_filter txflt;
#ifdef TUN_DEBUG
int debug;
#endif
};
+/* TAP filterting */
+static void addr_hash_set(u32 *mask, const u8 *addr)
+{
+ int n = ether_crc(ETH_ALEN, addr) >> 26;
+ mask[n >> 5] |= (1 << (n & 31));
+}
+
+static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
+{
+ int n = ether_crc(ETH_ALEN, addr) >> 26;
+ return mask[n >> 5] & (1 << (n & 31));
+}
+
+static int update_filter(struct tap_filter *filter, void __user *arg)
+{
+ struct { u8 u[ETH_ALEN]; } *addr;
+ struct tun_filter uf;
+ int err, alen, n, nexact;
+
+ if (copy_from_user(&uf, arg, sizeof(uf)))
+ return -EFAULT;
+
+ if (!uf.count) {
+ /* Disabled */
+ filter->count = 0;
+ return 0;
+ }
+
+ alen = ETH_ALEN * uf.count;
+ addr = kmalloc(alen, GFP_KERNEL);
+ if (!addr)
+ return -ENOMEM;
+
+ if (copy_from_user(addr, arg + sizeof(uf), alen)) {
+ err = -EFAULT;
+ goto done;
+ }
+
+ /* The filter is updated without holding any locks. Which is
+ * perfectly safe. We disable it first and in the worst
+ * case we'll accept a few undesired packets. */
+ filter->count = 0;
+ wmb();
+
+ /* Use first set of addresses as an exact filter */
+ for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
+ memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
+
+ nexact = n;
+
+ /* The rest is hashed */
+ memset(filter->mask, 0, sizeof(filter->mask));
+ for (; n < uf.count; n++)
+ addr_hash_set(filter->mask, addr[n].u);
+
+ /* For ALLMULTI just set the mask to all ones.
+ * This overrides the mask populated above. */
+ if ((uf.flags & TUN_FLT_ALLMULTI))
+ memset(filter->mask, ~0, sizeof(filter->mask));
+
+ /* Now enable the filter */
+ wmb();
+ filter->count = nexact;
+
+ /* Return the number of exact filters */
+ err = nexact;
+
+done:
+ kfree(addr);
+ return err;
+}
+
+/* Returns: 0 - drop, !=0 - accept */
+static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
+{
+ /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
+ * at this point. */
+ struct ethhdr *eh = (struct ethhdr *) skb->data;
+ int i;
+
+ /* Exact match */
+ for (i = 0; i < filter->count; i++)
+ if (!compare_ether_addr(eh->h_dest, filter->addr[i]))
+ return 1;
+
+ /* Inexact match (multicast only) */
+ if (is_multicast_ether_addr(eh->h_dest))
+ return addr_hash_test(filter->mask, eh->h_dest);
+
+ return 0;
+}
+
+/*
+ * Checks whether the packet is accepted or not.
+ * Returns: 0 - drop, !=0 - accept
+ */
+static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
+{
+ if (!filter->count)
+ return 1;
+
+ return run_filter(filter, skb);
+}
+
/* Network device part of the driver */
static unsigned int tun_net_id;
if (!tun->attached)
goto drop;
- /* Packet dropping */
+ /* Drop if the filter does not like it.
+ * This is a noop if the filter is disabled.
+ * Filter can be enabled only for the TAP devices. */
+ if (!check_filter(&tun->txflt, skb))
+ goto drop;
+
if (skb_queue_len(&tun->readq) >= dev->tx_queue_len) {
if (!(tun->flags & TUN_ONE_QUEUE)) {
/* Normal queueing mode. */
}
}
- /* Queue packet */
+ /* Enqueue packet */
skb_queue_tail(&tun->readq, skb);
dev->trans_start = jiffies;
return 0;
}
-/** Add the specified Ethernet address to this multicast filter. */
-static void
-add_multi(u32* filter, const u8* addr)
-{
- int bit_nr = ether_crc(ETH_ALEN, addr) >> 26;
- filter[bit_nr >> 5] |= 1 << (bit_nr & 31);
-}
-
-/** Remove the specified Ethernet addres from this multicast filter. */
-static void
-del_multi(u32* filter, const u8* addr)
+static void tun_net_mclist(struct net_device *dev)
{
- int bit_nr = ether_crc(ETH_ALEN, addr) >> 26;
- filter[bit_nr >> 5] &= ~(1 << (bit_nr & 31));
-}
-
-/** Update the list of multicast groups to which the network device belongs.
- * This list is used to filter packets being sent from the character device to
- * the network device. */
-static void
-tun_net_mclist(struct net_device *dev)
-{
- struct tun_struct *tun = netdev_priv(dev);
- const struct dev_mc_list *mclist;
- int i;
- DECLARE_MAC_BUF(mac);
- DBG(KERN_DEBUG "%s: tun_net_mclist: mc_count %d\n",
- dev->name, dev->mc_count);
- memset(tun->chr_filter, 0, sizeof tun->chr_filter);
- for (i = 0, mclist = dev->mc_list; i < dev->mc_count && mclist != NULL;
- i++, mclist = mclist->next) {
- add_multi(tun->net_filter, mclist->dmi_addr);
- DBG(KERN_DEBUG "%s: tun_net_mclist: %s\n",
- dev->name, print_mac(mac, mclist->dmi_addr));
- }
+ /*
+ * This callback is supposed to deal with mc filter in
+ * _rx_ path and has nothing to do with the _tx_ path.
+ * In rx path we always accept everything userspace gives us.
+ */
+ return;
}
#define MIN_MTU 68
case TUN_TAP_DEV:
/* Ethernet TAP Device */
- dev->set_multicast_list = tun_net_mclist;
-
ether_setup(dev);
- dev->change_mtu = tun_net_change_mtu;
+ dev->change_mtu = tun_net_change_mtu;
+ dev->set_multicast_list = tun_net_mclist;
- /* random address already created for us by tun_set_iff, use it */
- memcpy(dev->dev_addr, tun->dev_addr, min(sizeof(tun->dev_addr), sizeof(dev->dev_addr)) );
+ random_ether_addr(dev->dev_addr);
dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
break;
DECLARE_WAITQUEUE(wait, current);
struct sk_buff *skb;
ssize_t len, ret = 0;
- DECLARE_MAC_BUF(mac);
if (!tun)
return -EBADFD;
add_wait_queue(&tun->read_wait, &wait);
while (len) {
- const u8 ones[ ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
- u8 addr[ ETH_ALEN];
- int bit_nr;
-
current->state = TASK_INTERRUPTIBLE;
/* Read frames from the queue */
}
netif_wake_queue(tun->dev);
- /** Decide whether to accept this packet. This code is designed to
- * behave identically to an Ethernet interface. Accept the packet if
- * - we are promiscuous.
- * - the packet is addressed to us.
- * - the packet is broadcast.
- * - the packet is multicast and
- * - we are multicast promiscous.
- * - we belong to the multicast group.
- */
- skb_copy_from_linear_data(skb, addr, min_t(size_t, sizeof addr,
- skb->len));
- bit_nr = ether_crc(sizeof addr, addr) >> 26;
- if ((tun->if_flags & IFF_PROMISC) ||
- memcmp(addr, tun->dev_addr, sizeof addr) == 0 ||
- memcmp(addr, ones, sizeof addr) == 0 ||
- (((addr[0] == 1 && addr[1] == 0 && addr[2] == 0x5e) ||
- (addr[0] == 0x33 && addr[1] == 0x33)) &&
- ((tun->if_flags & IFF_ALLMULTI) ||
- (tun->chr_filter[bit_nr >> 5] & (1 << (bit_nr & 31)))))) {
- DBG(KERN_DEBUG "%s: tun_chr_readv: accepted: %s\n",
- tun->dev->name, print_mac(mac, addr));
- ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
- kfree_skb(skb);
- break;
- } else {
- DBG(KERN_DEBUG "%s: tun_chr_readv: rejected: %s\n",
- tun->dev->name, print_mac(mac, addr));
- kfree_skb(skb);
- continue;
- }
+ ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
+ kfree_skb(skb);
+ break;
}
current->state = TASK_RUNNING;
tun = netdev_priv(dev);
tun->dev = dev;
tun->flags = flags;
- /* Be promiscuous by default to maintain previous behaviour. */
- tun->if_flags = IFF_PROMISC;
- /* Generate random Ethernet address. */
- *(__be16 *)tun->dev_addr = htons(0x00FF);
- get_random_bytes(tun->dev_addr + sizeof(u16), 4);
- memset(tun->chr_filter, 0, sizeof tun->chr_filter);
+ tun->txflt.count = 0;
tun_net_init(dev);
struct tun_struct *tun = file->private_data;
void __user* argp = (void __user*)arg;
struct ifreq ifr;
+ int ret;
DECLARE_MAC_BUF(mac);
if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
break;
case TUNSETLINK:
- {
- int ret;
-
/* Only allow setting the type when the interface is down */
rtnl_lock();
if (tun->dev->flags & IFF_UP) {
}
rtnl_unlock();
return ret;
- }
#ifdef TUN_DEBUG
case TUNSETDEBUG:
tun->debug = arg;
break;
#endif
-
case TUNSETOFFLOAD:
- {
- int ret;
rtnl_lock();
ret = set_offload(tun->dev, arg);
rtnl_unlock();
return ret;
- }
- case SIOCGIFFLAGS:
- ifr.ifr_flags = tun->if_flags;
- if (copy_to_user( argp, &ifr, sizeof ifr))
- return -EFAULT;
- return 0;
-
- case SIOCSIFFLAGS:
- /** Set the character device's interface flags. Currently only
- * IFF_PROMISC and IFF_ALLMULTI are used. */
- tun->if_flags = ifr.ifr_flags;
- DBG(KERN_INFO "%s: interface flags 0x%lx\n",
- tun->dev->name, tun->if_flags);
- return 0;
+ case TUNSETTXFILTER:
+ /* Can be set only for TAPs */
+ if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
+ return -EINVAL;
+ rtnl_lock();
+ ret = update_filter(&tun->txflt, (void *) __user arg);
+ rtnl_unlock();
+ return ret;
case SIOCGIFHWADDR:
- /* Note: the actual net device's address may be different */
- memcpy(ifr.ifr_hwaddr.sa_data, tun->dev_addr,
- min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
- if (copy_to_user( argp, &ifr, sizeof ifr))
+ /* Get hw addres */
+ memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
+ ifr.ifr_hwaddr.sa_family = tun->dev->type;
+ if (copy_to_user(argp, &ifr, sizeof ifr))
return -EFAULT;
return 0;
case SIOCSIFHWADDR:
- {
- /* try to set the actual net device's hw address */
- int ret;
+ /* Set hw address */
+ DBG(KERN_DEBUG "%s: set hw address: %s\n",
+ tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data));
rtnl_lock();
ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
rtnl_unlock();
-
- if (ret == 0) {
- /** Set the character device's hardware address. This is used when
- * filtering packets being sent from the network device to the character
- * device. */
- memcpy(tun->dev_addr, ifr.ifr_hwaddr.sa_data,
- min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
- DBG(KERN_DEBUG "%s: set hardware address: %x:%x:%x:%x:%x:%x\n",
- tun->dev->name,
- tun->dev_addr[0], tun->dev_addr[1], tun->dev_addr[2],
- tun->dev_addr[3], tun->dev_addr[4], tun->dev_addr[5]);
- }
-
- return ret;
- }
-
- case SIOCADDMULTI:
- /** Add the specified group to the character device's multicast filter
- * list. */
- rtnl_lock();
- netif_tx_lock_bh(tun->dev);
- add_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
- netif_tx_unlock_bh(tun->dev);
- rtnl_unlock();
-
- DBG(KERN_DEBUG "%s: add multi: %s\n",
- tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data));
- return 0;
-
- case SIOCDELMULTI:
- /** Remove the specified group from the character device's multicast
- * filter list. */
- rtnl_lock();
- netif_tx_lock_bh(tun->dev);
- del_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
- netif_tx_unlock_bh(tun->dev);
- rtnl_unlock();
-
- DBG(KERN_DEBUG "%s: del multi: %s\n",
- tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data));
- return 0;
+ return ret;
default:
return -EINVAL;
projects / linux-2.6 / commitdiff