5.15-stable review patch. If anyone has any objections, please let me know.
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From: Anubhav Singh anubhavsinggh@google.com
[ Upstream commit f8e8486702abb05b8c734093aab1606af0eac068 ]
The GRO self-test, gro.c, currently constructs IPv6 packets containing a Hop-by-Hop Options header (IPPROTO_HOPOPTS) to ensure the GRO path correctly handles IPv6 extension headers.
However, network elements may be configured to drop packets with the Hop-by-Hop Options header (HBH). This causes the self-test to fail in environments where such network elements are present.
To improve the robustness and reliability of this test in diverse network environments, switch from using IPPROTO_HOPOPTS to IPPROTO_DSTOPTS (Destination Options).
The Destination Options header is less likely to be dropped by intermediate routers and still serves the core purpose of the test: validating GRO's handling of an IPv6 extension header. This change ensures the test can execute successfully without being incorrectly failed by network policies outside the kernel's control.
Fixes: 7d1575014a63 ("selftests/net: GRO coalesce test") Reviewed-by: Willem de Bruijn willemb@google.com Signed-off-by: Anubhav Singh anubhavsinggh@google.com Link: https://patch.msgid.link/20251030060436.1556664-1-anubhavsinggh@google.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- tools/testing/selftests/net/gro.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/net/gro.c b/tools/testing/selftests/net/gro.c index a6cf29c2c9318..e220b6f12336e 100644 --- a/tools/testing/selftests/net/gro.c +++ b/tools/testing/selftests/net/gro.c @@ -622,11 +622,11 @@ static void send_ipv6_exthdr(int fd, struct sockaddr_ll *daddr, char *ext_data1, static char exthdr_pck[sizeof(buf) + MIN_EXTHDR_SIZE];
create_packet(buf, 0, 0, PAYLOAD_LEN, 0); - add_ipv6_exthdr(buf, exthdr_pck, IPPROTO_HOPOPTS, ext_data1); + add_ipv6_exthdr(buf, exthdr_pck, IPPROTO_DSTOPTS, ext_data1); write_packet(fd, exthdr_pck, total_hdr_len + PAYLOAD_LEN + MIN_EXTHDR_SIZE, daddr);
create_packet(buf, PAYLOAD_LEN * 1, 0, PAYLOAD_LEN, 0); - add_ipv6_exthdr(buf, exthdr_pck, IPPROTO_HOPOPTS, ext_data2); + add_ipv6_exthdr(buf, exthdr_pck, IPPROTO_DSTOPTS, ext_data2); write_packet(fd, exthdr_pck, total_hdr_len + PAYLOAD_LEN + MIN_EXTHDR_SIZE, daddr); }