gtp_genl_send_echo_req() runs as a generic netlink doit handler in
process context with BH not disabled. It calls udp_tunnel_xmit_skb(),
which eventually invokes iptunnel_xmit() — that uses __this_cpu_inc/dec
on softnet_data.xmit.recursion to track the tunnel xmit recursion level.
Without local_bh_disable(), the task may migrate between
dev_xmit_recursion_inc() and dev_xmit_recursion_dec(), breaking the
per-CPU counter pairing. The result is stale or negative recursion
levels that can later produce false-positive
SKB_DROP_REASON_RECURSION_LIMIT drops on either CPU.
The other udp_tunnel_xmit_skb() call sites in gtp.c are unaffected:
the data path runs under ndo_start_xmit and the echo response handlers
run from the UDP encap rx softirq, both with BH already disabled.
Fix it by disabling BH around the udp_tunnel_xmit_skb() call, mirroring
commit 2cd7e6971f ("sctp: disable BH before calling
udp_tunnel_xmit_skb()").
Fixes: 6f1a9140ec ("net: add xmit recursion limit to tunnel xmit functions")
Cc: stable@vger.kernel.org
Signed-off-by: David Carlier <devnexen@gmail.com>
Link: https://patch.msgid.link/20260417055408.4667-1-devnexen@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
Convert the ->flowic_tos field of struct flowi_common from __u8 to
dscp_t, rename it ->flowic_dscp and propagate these changes to struct
flowi and struct flowi4.
We've had several bugs in the past where ECN bits could interfere with
IPv4 routing, because these bits were not properly cleared when setting
->flowi4_tos. These bugs should be fixed now and the dscp_t type has
been introduced to ensure that variables carrying DSCP values don't
accidentally have any ECN bits set. Several variables and structure
fields have been converted to dscp_t already, but the main IPv4 routing
structure, struct flowi4, is still using a __u8. To avoid any future
regression, this patch converts it to dscp_t.
There are many users to convert at once. Fortunately, around half of
->flowi4_tos users already have a dscp_t value at hand, which they
currently convert to __u8 using inet_dscp_to_dsfield(). For all of
these users, we just need to drop that conversion.
But, although we try to do the __u8 <-> dscp_t conversions at the
boundaries of the network or of user space, some places still store
TOS/DSCP variables as __u8 in core networking code. Those can hardly be
converted either because the data structure is part of UAPI or because
the same variable or field is also used for handling ECN in other parts
of the code. In all of these cases where we don't have a dscp_t
variable at hand, we need to use inet_dsfield_to_dscp() when
interacting with ->flowi4_dscp.
Changes since v1:
* Fix space alignment in __bpf_redirect_neigh_v4() (Ido).
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/29acecb45e911d17446b9a3dbdb1ab7b821ea371.1756128932.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add two helper functions - rtnl_newlink_link_net() and
rtnl_newlink_peer_net() for netns fallback logic. Peer netns falls back
to link netns, and link netns falls back to source netns.
Convert the use of params->net in netdevice drivers to one of the helper
functions for clarity.
Signed-off-by: Xiao Liang <shaw.leon@gmail.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250219125039.18024-4-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>
gtp_newlink() links the gtp device to a list in dev_net(dev).
However, even after the gtp device is moved to another netns,
it stays on the list but should be invisible.
Let's use for_each_netdev_rcu() for netdev traversal in
gtp_genl_dump_pdp().
Note that gtp_dev_list is no longer used under RCU, so list
helpers are converted to the non-RCU variant.
Fixes: 459aa660eb ("gtp: add initial driver for datapath of GPRS Tunneling Protocol (GTP-U)")
Reported-by: Xiao Liang <shaw.leon@gmail.com>
Closes: https://lore.kernel.org/netdev/CABAhCOQdBL6h9M2C+kd+bGivRJ9Q72JUxW+-gur0nub_=PmFPA@mail.gmail.com/
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Most of the original conversion is from the spatch below,
but I edited some and left out other instances that were
either buggy after conversion (where default values don't
fit into the type) or just looked strange.
@@
expression attr, def;
expression val;
identifier fn =~ "^nla_get_.*";
fresh identifier dfn = fn ## "_default";
@@
(
-if (attr)
- val = fn(attr);
-else
- val = def;
+val = dfn(attr, def);
|
-if (!attr)
- val = def;
-else
- val = fn(attr);
+val = dfn(attr, def);
|
-if (!attr)
- return def;
-return fn(attr);
+return dfn(attr, def);
|
-attr ? fn(attr) : def
+dfn(attr, def)
|
-!attr ? def : fn(attr)
+dfn(attr, def)
)
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@kernel.org>
Link: https://patch.msgid.link/20241108114145.0580b8684e7f.I740beeaa2f70ebfc19bfca1045a24d6151992790@changeid
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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>
This allows to define a GTP tunnel for dual stack MS/UE with both IPv4
and IPv6 addresses while using the same TEID via two PDP context
objects.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add new protocol field to PDP context that determines the transmit path
IP protocol to encapsulate the original packets, either IPv4 or IPv6.
Relax existing netlink attribute checks to allow to specify different
family in MS and peer attributes from the control plane.
Use build helpers to tx path to encapsulate IPv4-in-IPv6-GTP and
IPv6-in-IPv4-GTP according to the user-specified configuration.
From rx path, snoop for the inner protocol header since outer
skb->protocol might differ and use this to validate for valid PDP
context and to restore skb->protocol after decapsulation.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add routine to attach an IPv6 route for the encapsulated packet, deal
with Path MTU and push GTP header.
This helper function will be used to deal with IPv4-in-IPv6-GTP.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add routine to attach an IPv4 route for the encapsulated packet, deal
with Path MTU and push GTP header.
This helper function will be used to deal with IPv6-in-IPv4-GTP.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Based on the idea that ip_tunnel_get_dsfield() provides the tos field
regardless the IP version, use either iph->tos or ipv6_get_dsfield().
This comes in preparation to support for IPv4-in-IPv6-GTP and
IPv6-in-IPv4-GTP.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Move debugging to the routine to build GTP packets in preparation
for supporting IPv4-in-IPv6-GTP and IPv6-in-IPv4-GTP.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
