linux-stable.git/net/ipv4/ip_gre.c, branch linux-6.16.y Linux kernel stable tree ipv4: ip_tunnel: Convert ip_tunnel_delete_nets() callers to ->exit_rtnl(). 2025-04-15T00:08:42+00:00 Kuniyuki Iwashima kuniyu@amazon.com 2025-04-11T20:52:35+00:00 a967e01e2ad201f6ddc778ed65a5dae1c68ee8a5 ip_tunnel_delete_nets() iterates the dying netns list and performs the same operations for each. Let's export ip_tunnel_destroy() as ip_tunnel_delete_net() and call it from ->exit_rtnl(). Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Link: https://patch.msgid.link/20250411205258.63164-7-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
ip_tunnel_delete_nets() iterates the dying netns list and performs the
same operations for each.

Let's export ip_tunnel_destroy() as ip_tunnel_delete_net() and call it
from ->exit_rtnl().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Link: https://patch.msgid.link/20250411205258.63164-7-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: ip_tunnel: Use link netns in newlink() of rtnl_link_ops 2025-02-21T23:28:02+00:00 Xiao Liang shaw.leon@gmail.com 2025-02-19T12:50:32+00:00 eacb1160536e097ba1eb910a1b212d1032d2e9c6 When link_net is set, use it as link netns instead of dev_net(). This prepares for rtnetlink core to create device in target netns directly, in which case the two namespaces may be different. Convert common ip_tunnel_newlink() to accept an extra link netns argument. Signed-off-by: Xiao Liang <shaw.leon@gmail.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250219125039.18024-7-shaw.leon@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
When link_net is set, use it as link netns instead of dev_net(). This
prepares for rtnetlink core to create device in target netns directly,
in which case the two namespaces may be different.

Convert common ip_tunnel_newlink() to accept an extra link netns
argument.

Signed-off-by: Xiao Liang <shaw.leon@gmail.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250219125039.18024-7-shaw.leon@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
rtnetlink: Pack newlink() params into struct 2025-02-21T23:28:02+00:00 Xiao Liang shaw.leon@gmail.com 2025-02-19T12:50:28+00:00 69c7be1b903fca2835e80ec506bd1d75ce84fb4d There are 4 net namespaces involved when creating links: - source netns - where the netlink socket resides, - target netns - where to put the device being created, - link netns - netns associated with the device (backend), - peer netns - netns of peer device. Currently, two nets are passed to newlink() callback - "src_net" parameter and "dev_net" (implicitly in net_device). They are set as follows, depending on netlink attributes in the request. +------------+-------------------+---------+---------+ | peer netns | IFLA_LINK_NETNSID | src_net | dev_net | +------------+-------------------+---------+---------+ | | absent | source | target | | absent +-------------------+---------+---------+ | | present | link | link | +------------+-------------------+---------+---------+ | | absent | peer | target | | present +-------------------+---------+---------+ | | present | peer | link | +------------+-------------------+---------+---------+ When IFLA_LINK_NETNSID is present, the device is created in link netns first and then moved to target netns. This has some side effects, including extra ifindex allocation, ifname validation and link events. These could be avoided if we create it in target netns from the beginning. On the other hand, the meaning of src_net parameter is ambiguous. It varies depending on how parameters are passed. It is the effective link (or peer netns) by design, but some drivers ignore it and use dev_net instead. To provide more netns context for drivers, this patch packs existing newlink() parameters, along with the source netns, link netns and peer netns, into a struct. The old "src_net" is renamed to "net" to avoid confusion with real source netns, and will be deprecated later. The use of src_net are converted to params->net trivially. Signed-off-by: Xiao Liang <shaw.leon@gmail.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250219125039.18024-3-shaw.leon@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
There are 4 net namespaces involved when creating links:

 - source netns - where the netlink socket resides,
 - target netns - where to put the device being created,
 - link netns - netns associated with the device (backend),
 - peer netns - netns of peer device.

Currently, two nets are passed to newlink() callback - "src_net"
parameter and "dev_net" (implicitly in net_device). They are set as
follows, depending on netlink attributes in the request.

 +------------+-------------------+---------+---------+
 | peer netns | IFLA_LINK_NETNSID | src_net | dev_net |
 +------------+-------------------+---------+---------+
 |            | absent            | source  | target  |
 | absent     +-------------------+---------+---------+
 |            | present           | link    | link    |
 +------------+-------------------+---------+---------+
 |            | absent            | peer    | target  |
 | present    +-------------------+---------+---------+
 |            | present           | peer    | link    |
 +------------+-------------------+---------+---------+

When IFLA_LINK_NETNSID is present, the device is created in link netns
first and then moved to target netns. This has some side effects,
including extra ifindex allocation, ifname validation and link events.
These could be avoided if we create it in target netns from
the beginning.

On the other hand, the meaning of src_net parameter is ambiguous. It
varies depending on how parameters are passed. It is the effective
link (or peer netns) by design, but some drivers ignore it and use
dev_net instead.

To provide more netns context for drivers, this patch packs existing
newlink() parameters, along with the source netns, link netns and peer
netns, into a struct. The old "src_net" is renamed to "net" to avoid
confusion with real source netns, and will be deprecated later. The use
of src_net are converted to params->net trivially.

Signed-off-by: Xiao Liang <shaw.leon@gmail.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250219125039.18024-3-shaw.leon@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ipv4: ip_gre: Fix set but not used warning in ipgre_err() if IPv4-only 2025-02-06T02:48:45+00:00 Geert Uytterhoeven geert@linux-m68k.org 2025-02-04T21:36:54+00:00 50f37fc2a39c4a8cc4813629b4cf239b71c6097d if CONFIG_NET_IPGRE is enabled, but CONFIG_IPV6 is disabled: net/ipv4/ip_gre.c: In function ‘ipgre_err’: net/ipv4/ip_gre.c:144:22: error: variable ‘data_len’ set but not used [-Werror=unused-but-set-variable] 144 | unsigned int data_len = 0; | ^~~~~~~~ Fix this by moving all data_len processing inside the IPV6-only section that uses its result. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202501121007.2GofXmh5-lkp@intel.com/ Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/d09113cfe2bfaca02f3dddf832fb5f48dd20958b.1738704881.git.geert@linux-m68k.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
if CONFIG_NET_IPGRE is enabled, but CONFIG_IPV6 is disabled:

    net/ipv4/ip_gre.c: In function ‘ipgre_err’:
    net/ipv4/ip_gre.c:144:22: error: variable ‘data_len’ set but not used [-Werror=unused-but-set-variable]
      144 |         unsigned int data_len = 0;
	  |                      ^~~~~~~~

Fix this by moving all data_len processing inside the IPV6-only section
that uses its result.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202501121007.2GofXmh5-lkp@intel.com/
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/d09113cfe2bfaca02f3dddf832fb5f48dd20958b.1738704881.git.geert@linux-m68k.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
gre: Prepare ipgre_open() to .flowi4_tos conversion. 2025-01-17T00:51:57+00:00 Guillaume Nault gnault@redhat.com 2025-01-15T11:53:55+00:00 2c77bcb344f589054b2039bddcd32c4f666258b9 Use ip4h_dscp() to get the tunnel DSCP option as dscp_t, instead of manually masking the raw tos field with INET_DSCP_MASK. This will ease the conversion of fl4->flowi4_tos to dscp_t, which just becomes a matter of dropping the inet_dscp_to_dsfield() call. Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/6c05a11afdc61530f1a4505147e0909ad51feb15.1736941806.git.gnault@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Use ip4h_dscp() to get the tunnel DSCP option as dscp_t, instead of
manually masking the raw tos field with INET_DSCP_MASK. This will ease
the conversion of fl4->flowi4_tos to dscp_t, which just becomes a
matter of dropping the inet_dscp_to_dsfield() call.

Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/6c05a11afdc61530f1a4505147e0909ad51feb15.1736941806.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
gre: Drop ip_route_output_gre(). 2024-12-20T03:24:47+00:00 Guillaume Nault gnault@redhat.com 2024-12-18T13:17:16+00:00 29b540795b42a3e610c0d5e9d908a8d6c1333676 We already have enough variants of ip_route_output*() functions. We don't need a GRE specific one in the generic route.h header file. Furthermore, ip_route_output_gre() is only used once, in ipgre_open(), where it can be easily replaced by a simple call to ip_route_output_key(). While there, and for clarity, explicitly set .flowi4_scope to RT_SCOPE_UNIVERSE instead of relying on the implicit zero initialisation. Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com> Link: https://patch.msgid.link/ab7cba47b8558cd4bfe2dc843c38b622a95ee48e.1734527729.git.gnault@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
We already have enough variants of ip_route_output*() functions. We
don't need a GRE specific one in the generic route.h header file.

Furthermore, ip_route_output_gre() is only used once, in ipgre_open(),
where it can be easily replaced by a simple call to
ip_route_output_key().

While there, and for clarity, explicitly set .flowi4_scope to
RT_SCOPE_UNIVERSE instead of relying on the implicit zero
initialisation.

Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Link: https://patch.msgid.link/ab7cba47b8558cd4bfe2dc843c38b622a95ee48e.1734527729.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ipv4: ip_gre: Fix drops of small packets in ipgre_xmit 2024-10-01T11:04:03+00:00 Anton Danilov littlesmilingcloud@gmail.com 2024-09-24T23:51:59+00:00 c4a14f6d9d17ad1e41a36182dd3b8a5fd91efbd7 Regression Description: Depending on the options specified for the GRE tunnel device, small packets may be dropped. This occurs because the pskb_network_may_pull function fails due to the packet's insufficient length. For example, if only the okey option is specified for the tunnel device, original (before encapsulation) packets smaller than 28 bytes (including the IPv4 header) will be dropped. This happens because the required length is calculated relative to the network header, not the skb->head. Here is how the required length is computed and checked: * The pull_len variable is set to 28 bytes, consisting of: * IPv4 header: 20 bytes * GRE header with Key field: 8 bytes * The pskb_network_may_pull function adds the network offset, shifting the checkable space further to the beginning of the network header and extending it to the beginning of the packet. As a result, the end of the checkable space occurs beyond the actual end of the packet. Instead of ensuring that 28 bytes are present in skb->head, the function is requesting these 28 bytes starting from the network header. For small packets, this requested length exceeds the actual packet size, causing the check to fail and the packets to be dropped. This issue affects both locally originated and forwarded packets in DMVPN-like setups. How to reproduce (for local originated packets): ip link add dev gre1 type gre ikey 1.9.8.4 okey 1.9.8.4 \ local <your-ip> remote 0.0.0.0 ip link set mtu 1400 dev gre1 ip link set up dev gre1 ip address add 192.168.13.1/24 dev gre1 ip neighbor add 192.168.13.2 lladdr <remote-ip> dev gre1 ping -s 1374 -c 10 192.168.13.2 tcpdump -vni gre1 tcpdump -vni <your-ext-iface> 'ip proto 47' ip -s -s -d link show dev gre1 Solution: Use the pskb_may_pull function instead the pskb_network_may_pull. Fixes: 80d875cfc9d3 ("ipv4: ip_gre: Avoid skb_pull() failure in ipgre_xmit()") Signed-off-by: Anton Danilov <littlesmilingcloud@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20240924235158.106062-1-littlesmilingcloud@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> 
Regression Description:

Depending on the options specified for the GRE tunnel device, small
packets may be dropped. This occurs because the pskb_network_may_pull
function fails due to the packet's insufficient length.

For example, if only the okey option is specified for the tunnel device,
original (before encapsulation) packets smaller than 28 bytes (including
the IPv4 header) will be dropped. This happens because the required
length is calculated relative to the network header, not the skb->head.

Here is how the required length is computed and checked:

* The pull_len variable is set to 28 bytes, consisting of:
  * IPv4 header: 20 bytes
  * GRE header with Key field: 8 bytes

* The pskb_network_may_pull function adds the network offset, shifting
the checkable space further to the beginning of the network header and
extending it to the beginning of the packet. As a result, the end of
the checkable space occurs beyond the actual end of the packet.

Instead of ensuring that 28 bytes are present in skb->head, the function
is requesting these 28 bytes starting from the network header. For small
packets, this requested length exceeds the actual packet size, causing
the check to fail and the packets to be dropped.

This issue affects both locally originated and forwarded packets in
DMVPN-like setups.

How to reproduce (for local originated packets):

  ip link add dev gre1 type gre ikey 1.9.8.4 okey 1.9.8.4 \
          local <your-ip> remote 0.0.0.0

  ip link set mtu 1400 dev gre1
  ip link set up dev gre1
  ip address add 192.168.13.1/24 dev gre1
  ip neighbor add 192.168.13.2 lladdr <remote-ip> dev gre1
  ping -s 1374 -c 10 192.168.13.2
  tcpdump -vni gre1
  tcpdump -vni <your-ext-iface> 'ip proto 47'
  ip -s -s -d link show dev gre1

Solution:

Use the pskb_may_pull function instead the pskb_network_may_pull.

Fixes: 80d875cfc9d3 ("ipv4: ip_gre: Avoid skb_pull() failure in ipgre_xmit()")
Signed-off-by: Anton Danilov <littlesmilingcloud@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20240924235158.106062-1-littlesmilingcloud@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
ipv4: ip_gre: Unmask upper DSCP bits in ipgre_open() 2024-09-09T13:14:52+00:00 Ido Schimmel idosch@nvidia.com 2024-09-05T16:51:30+00:00 25376a890119b616d5982c8cb59f805138ab81fa Unmask the upper DSCP bits when calling ip_route_output_gre() so that in the future it could perform the FIB lookup according to the full DSCP value. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Unmask the upper DSCP bits when calling ip_route_output_gre() so that in
the future it could perform the FIB lookup according to the full DSCP
value.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
netdev_features: convert NETIF_F_LLTX to dev->lltx 2024-09-03T09:36:43+00:00 Alexander Lobakin aleksander.lobakin@intel.com 2024-08-29T12:33:37+00:00 00d066a4d4edbe559ba6c35153da71d4b2b8a383 NETIF_F_LLTX can't be changed via Ethtool and is not a feature, rather an attribute, very similar to IFF_NO_QUEUE (and hot). Free one netdev_features_t bit and make it a "hot" private flag. Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> 
NETIF_F_LLTX can't be changed via Ethtool and is not a feature,
rather an attribute, very similar to IFF_NO_QUEUE (and hot).
Free one netdev_features_t bit and make it a "hot" private flag.

Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
net: annotate writes on dev->mtu from ndo_change_mtu() 2024-05-07T23:19:14+00:00 Eric Dumazet edumazet@google.com 2024-05-06T10:28:12+00:00 1eb2cded45b35816085c1f962933c187d970f9dc Simon reported that ndo_change_mtu() methods were never updated to use WRITE_ONCE(dev->mtu, new_mtu) as hinted in commit 501a90c94510 ("inet: protect against too small mtu values.") We read dev->mtu without holding RTNL in many places, with READ_ONCE() annotations. It is time to take care of ndo_change_mtu() methods to use corresponding WRITE_ONCE() Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Simon Horman <horms@kernel.org> Closes: https://lore.kernel.org/netdev/20240505144608.GB67882@kernel.org/ Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Simon Horman <horms@kernel.org> Acked-by: Shannon Nelson <shannon.nelson@amd.com> Link: https://lore.kernel.org/r/20240506102812.3025432-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Simon reported that ndo_change_mtu() methods were never
updated to use WRITE_ONCE(dev->mtu, new_mtu) as hinted
in commit 501a90c94510 ("inet: protect against too small
mtu values.")

We read dev->mtu without holding RTNL in many places,
with READ_ONCE() annotations.

It is time to take care of ndo_change_mtu() methods
to use corresponding WRITE_ONCE()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Simon Horman <horms@kernel.org>
Closes: https://lore.kernel.org/netdev/20240505144608.GB67882@kernel.org/
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Simon Horman <horms@kernel.org>
Acked-by: Shannon Nelson <shannon.nelson@amd.com>
Link: https://lore.kernel.org/r/20240506102812.3025432-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>