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Diffstat (limited to 'drivers/net/tun.c')
-rw-r--r--drivers/net/tun.c64
1 files changed, 40 insertions, 24 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 1d68921723dc..c452d6d831dd 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1,17 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/*
* TUN - Universal TUN/TAP device driver.
* Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
* $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
*/
@@ -596,18 +587,22 @@ static u16 tun_automq_select_queue(struct tun_struct *tun, struct sk_buff *skb)
static u16 tun_ebpf_select_queue(struct tun_struct *tun, struct sk_buff *skb)
{
struct tun_prog *prog;
+ u32 numqueues;
u16 ret = 0;
+ numqueues = READ_ONCE(tun->numqueues);
+ if (!numqueues)
+ return 0;
+
prog = rcu_dereference(tun->steering_prog);
if (prog)
ret = bpf_prog_run_clear_cb(prog->prog, skb);
- return ret % tun->numqueues;
+ return ret % numqueues;
}
static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb,
- struct net_device *sb_dev,
- select_queue_fallback_t fallback)
+ struct net_device *sb_dev)
{
struct tun_struct *tun = netdev_priv(dev);
u16 ret;
@@ -700,6 +695,8 @@ static void __tun_detach(struct tun_file *tfile, bool clean)
tun->tfiles[tun->numqueues - 1]);
ntfile = rtnl_dereference(tun->tfiles[index]);
ntfile->queue_index = index;
+ rcu_assign_pointer(tun->tfiles[tun->numqueues - 1],
+ NULL);
--tun->numqueues;
if (clean) {
@@ -1043,7 +1040,7 @@ static int tun_net_close(struct net_device *dev)
static void tun_automq_xmit(struct tun_struct *tun, struct sk_buff *skb)
{
#ifdef CONFIG_RPS
- if (tun->numqueues == 1 && static_key_false(&rps_needed)) {
+ if (tun->numqueues == 1 && static_branch_unlikely(&rps_needed)) {
/* Select queue was not called for the skbuff, so we extract the
* RPS hash and save it into the flow_table here.
*/
@@ -1082,7 +1079,7 @@ static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
tfile = rcu_dereference(tun->tfiles[txq]);
/* Drop packet if interface is not attached */
- if (txq >= tun->numqueues)
+ if (!tfile)
goto drop;
if (!rcu_dereference(tun->steering_prog))
@@ -1305,6 +1302,7 @@ static int tun_xdp_xmit(struct net_device *dev, int n,
rcu_read_lock();
+resample:
numqueues = READ_ONCE(tun->numqueues);
if (!numqueues) {
rcu_read_unlock();
@@ -1313,6 +1311,8 @@ static int tun_xdp_xmit(struct net_device *dev, int n,
tfile = rcu_dereference(tun->tfiles[smp_processor_id() %
numqueues]);
+ if (unlikely(!tfile))
+ goto resample;
spin_lock(&tfile->tx_ring.producer_lock);
for (i = 0; i < n; i++) {
@@ -1763,9 +1763,6 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
int skb_xdp = 1;
bool frags = tun_napi_frags_enabled(tfile);
- if (!(tun->dev->flags & IFF_UP))
- return -EIO;
-
if (!(tun->flags & IFF_NO_PI)) {
if (len < sizeof(pi))
return -EINVAL;
@@ -1867,6 +1864,8 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
err = skb_copy_datagram_from_iter(skb, 0, from, len);
if (err) {
+ err = -EFAULT;
+drop:
this_cpu_inc(tun->pcpu_stats->rx_dropped);
kfree_skb(skb);
if (frags) {
@@ -1874,7 +1873,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
mutex_unlock(&tfile->napi_mutex);
}
- return -EFAULT;
+ return err;
}
}
@@ -1958,13 +1957,22 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
!tfile->detached)
rxhash = __skb_get_hash_symmetric(skb);
+ rcu_read_lock();
+ if (unlikely(!(tun->dev->flags & IFF_UP))) {
+ err = -EIO;
+ rcu_read_unlock();
+ goto drop;
+ }
+
if (frags) {
/* Exercise flow dissector code path. */
- u32 headlen = eth_get_headlen(skb->data, skb_headlen(skb));
+ u32 headlen = eth_get_headlen(tun->dev, skb->data,
+ skb_headlen(skb));
if (unlikely(headlen > skb_headlen(skb))) {
this_cpu_inc(tun->pcpu_stats->rx_dropped);
napi_free_frags(&tfile->napi);
+ rcu_read_unlock();
mutex_unlock(&tfile->napi_mutex);
WARN_ON(1);
return -ENOMEM;
@@ -1992,6 +2000,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
} else {
netif_rx_ni(skb);
}
+ rcu_read_unlock();
stats = get_cpu_ptr(tun->pcpu_stats);
u64_stats_update_begin(&stats->syncp);
@@ -2865,8 +2874,7 @@ err_free_dev:
return err;
}
-static void tun_get_iff(struct net *net, struct tun_struct *tun,
- struct ifreq *ifr)
+static void tun_get_iff(struct tun_struct *tun, struct ifreq *ifr)
{
tun_debug(KERN_INFO, tun, "tun_get_iff\n");
@@ -3095,10 +3103,11 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd);
+ net = dev_net(tun->dev);
ret = 0;
switch (cmd) {
case TUNGETIFF:
- tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
+ tun_get_iff(tun, &ifr);
if (tfile->detached)
ifr.ifr_flags |= IFF_DETACH_QUEUE;
@@ -3320,6 +3329,13 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
ret = tun_net_change_carrier(tun->dev, (bool)carrier);
break;
+ case TUNGETDEVNETNS:
+ ret = -EPERM;
+ if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
+ goto unlock;
+ ret = open_related_ns(&net->ns, get_net_ns);
+ break;
+
default:
ret = -EINVAL;
break;
@@ -3449,7 +3465,7 @@ static void tun_chr_show_fdinfo(struct seq_file *m, struct file *file)
rtnl_lock();
tun = tun_get(tfile);
if (tun)
- tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
+ tun_get_iff(tun, &ifr);
rtnl_unlock();
if (tun)
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