linux/include
Ido Schimmel d12d04d221 ipv6: icmp: Add RFC 5837 support
Add the ability to append the incoming IP interface information to
ICMPv6 error messages in accordance with RFC 5837 and RFC 4884. This is
required for more meaningful traceroute results in unnumbered networks.

The feature is disabled by default and controlled via a new sysctl
("net.ipv6.icmp.errors_extension_mask") which accepts a bitmask of ICMP
extensions to append to ICMP error messages. Currently, only a single
value is supported, but the interface and the implementation should be
able to support more extensions, if needed.

Clone the skb and copy the relevant data portions before modifying the
skb as the caller of icmp6_send() still owns the skb after the function
returns. This should be fine since by default ICMP error messages are
rate limited to 1000 per second and no more than 1 per second per
specific host.

Trim or pad the packet to 128 bytes before appending the ICMP extension
structure in order to be compatible with legacy applications that assume
that the ICMP extension structure always starts at this offset (the
minimum length specified by RFC 4884).

Since commit 20e1954fe2 ("ipv6: RFC 4884 partial support for SIT/GRE
tunnels") it is possible for icmp6_send() to be called with an skb that
already contains ICMP extensions. This can happen when we receive an
ICMPv4 message with extensions from a tunnel and translate it to an
ICMPv6 message towards an IPv6 host in the overlay network. I could not
find an RFC that supports this behavior, but it makes sense to not
overwrite the original extensions that were appended to the packet.
Therefore, avoid appending extensions if the length field in the
provided ICMPv6 header is already filled.

Export netdev_copy_name() using EXPORT_IPV6_MOD_GPL() to make it
available to IPv6 when it is built as a module.

Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251027082232.232571-3-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
History 2025-10-29 18:28:30 -07:00
..
acpi More power management updates for 6.18-rc1 2025-10-07 09:39:51 -07:00
asm-generic hyperv-next for v6.18 2025-10-07 08:40:15 -07:00
clocksource clocksource/drivers/arm_arch_timer_mmio: Switch over to standalone driver 2025-09-23 12:31:50 +02:00
crypto This update includes the following changes: 2025-10-04 14:59:29 -07:00
cxl cxl/events: Trace Memory Sparing Event Record 2025-07-18 08:19:56 -07:00
drm drm/gpuvm: Fix kernel-doc warning for drm_gpuvm_map_req.map 2025-10-15 18:37:05 +02:00
dt-bindings There's a bunch of patches here across drivers/clk/ to migrate drivers to use 2025-10-07 09:28:37 -07:00
hyperv hyperv: Remove the spurious null directive line 2025-10-02 21:21:24 +00:00
keys KEYS: trusted_tpm1: Move private functionality out of public header 2025-09-27 21:05:06 +03:00
kunit linux_kselftest-kunit-6.18-rc1 2025-10-01 19:15:11 -07:00
kvm KVM: arm64: Kill leftovers of ad-hoc timer userspace access 2025-10-13 14:42:41 +01:00
linux ipv4: icmp: Add RFC 5837 support 2025-10-29 18:28:29 -07:00
math-emu powerpc/math-emu: Remove -w build flag and fix warnings 2022-09-05 17:28:25 +10:00
media media: v4l2-common: Add legacy camera sensor clock helper 2025-09-09 15:59:19 +02:00
memory memory: renesas-rpc-if: Add RZ/G3E xSPI support 2025-05-01 12:22:25 +02:00
misc cxl: Remove driver 2025-03-16 22:04:27 +11:00
net ipv6: icmp: Add RFC 5837 support 2025-10-29 18:28:30 -07:00
pcmcia pcmcia: remove PCCARD_IODYN 2025-08-16 15:37:47 +02:00
ras tracing, AER: Hide PCIe AER event when PCIEAER is not configured 2025-07-21 16:40:56 -04:00
rdma RDMA/ucma: Support write an event into a CM 2025-08-13 06:16:11 -04:00
rv kernel-6.18-rc1.clone3 2025-09-29 10:36:50 -07:00
scsi SCSI misc on 20251002 2025-10-03 19:17:48 -07:00
soc There's a bunch of patches here across drivers/clk/ to migrate drivers to use 2025-10-07 09:28:37 -07:00
sound ASoC: tas2781: Support more newly-released amplifiers tas58xx in the driver 2025-10-13 11:08:09 +01:00
target scsi: target: core: Constify enabled() in struct target_opcode_descriptor 2025-05-20 22:11:03 -04:00
trace dma-mapping fixes for Linux 6.18: 2025-10-07 12:48:06 -07:00
uapi net/tls: support setting the maximum payload size 2025-10-27 16:13:42 -07:00
ufs scsi: ufs: core: Include UTP error in INT_FATAL_ERRORS 2025-09-30 16:10:29 -04:00
vdso Updates for the VDSO subsystem: 2025-09-30 16:58:21 -07:00
video drm/vesadrm: Support DRM_FORMAT_C8 2025-08-26 09:54:20 +02:00
xen xen: replace XENFEAT_auto_translated_physmap with xen_pv_domain() 2025-09-08 17:01:36 +02:00
Kbuild drm: ensure drm headers are self-contained and pass kernel-doc 2025-02-12 10:44:43 +02:00