kernel.git/tools/testing/selftests/net/udpgso.c, branch linux-5.4.y

udp: gso: do not drop small packets when PMTU reduces

2025-03-13T11:43:06Z

[ Upstream commit 235174b2bed88501fda689c113c55737f99332d8 ] Commit 4094871db1d6 ("udp: only do GSO if # of segs > 1") avoided GSO for small packets. But the kernel currently dismisses GSO requests only after checking MTU/PMTU on gso_size. This means any packets, regardless of their payload sizes, could be dropped when PMTU becomes smaller than requested gso_size. We encountered this issue in production and it caused a reliability problem that new QUIC connection cannot be established before PMTU cache expired, while non GSO sockets still worked fine at the same time. Ideally, do not check any GSO related constraints when payload size is smaller than requested gso_size, and return EMSGSIZE instead of EINVAL on MTU/PMTU check failure to be more specific on the error cause. Fixes: 4094871db1d6 ("udp: only do GSO if # of segs > 1") Signed-off-by: Yan Zhai Suggested-by: Willem de Bruijn Reviewed-by: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

selftests: Calculate udpgso segment count without header adjustment

2022-01-05T11:37:44Z

[ Upstream commit 5471d5226c3b39b3d2f7011c082d5715795bd65c ] The below referenced commit correctly updated the computation of number of segments (gso_size) by using only the gso payload size and removing the header lengths. With this change the regression test started failing. Update the tests to match this new behavior. Both IPv4 and IPv6 tests are updated, as a separate patch in this series will update udp_v6_send_skb to match this change in udp_send_skb. Fixes: 158390e45612 ("udp: using datalen to cap max gso segments") Signed-off-by: Coco Li Reviewed-by: Willem de Bruijn Link: https://lore.kernel.org/r/20211223222441.2975883-2-lixiaoyan@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

selftests: net: Fix printf format warnings on arm

2019-12-31T15:45:09Z

[ Upstream commit 670cd6849ea36ea4df2f2941cf4717dff8755abe ] Fix printf format warnings on arm (and other 32bit arch). - udpgso.c and udpgso_bench_tx use %lu for size_t but it should be unsigned long long on 32bit arch. - so_txtime.c uses %ld for int64_t, but it should be unsigned long long on 32bit arch. Signed-off-by: Masami Hiramatsu Cc: Willem de Bruijn Cc: David S. Miller Signed-off-by: Shuah Khan Signed-off-by: Sasha Levin

udp: only do GSO if # of segs > 1

2019-10-03T15:47:10Z

Prior to this change an application sending <= 1MSS worth of data and enabling UDP GSO would fail if the system had SW GSO enabled, but the same send would succeed if HW GSO offload is enabled. In addition to this inconsistency the error in the SW GSO case does not get back to the application if sending out of a real device so the user is unaware of this failure. With this change we only perform GSO if the # of segments is > 1 even if the application has enabled segmentation. I've also updated the relevant udpgso selftests. Fixes: bec1f6f69736 ("udp: generate gso with UDP_SEGMENT") Signed-off-by: Josh Hunt Reviewed-by: Willem de Bruijn Reviewed-by: Alexander Duyck Signed-off-by: David S. Miller

selftest/net: Remove duplicate header

2019-03-04T19:35:51Z

Remove duplicate header which is included twice. Signed-off-by: Sabyasachi Gupta Signed-off-by: Souptick Joarder Signed-off-by: David S. Miller

selftests/net: udpgso: test small gso_size boundary conditions

2018-06-04T13:49:39Z

Verify that udpgso can generate segments smaller than device mtu, down to the extreme case of 1B gso_size. Verify that irrespective of gso_size, udpgso restricts the number of segments it will generate per call (UDP_MAX_SEGMENTS). Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller

selftests: udp gso with corking

2018-04-26T19:09:52Z

Corked sockets take a different path to construct a udp datagram than the lockless fast path. Test this alternate path. Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller

selftests: udp gso with connected sockets

2018-04-26T19:09:52Z

Connected sockets use path mtu instead of device mtu. Test this path by inserting a route mtu that is lower than the device mtu. Verify that the path mtu for the connection matches this lower number, then run the same test as in the connectionless case. Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller

selftests: udp gso

2018-04-26T19:09:40Z

Validate udp gso, including edge cases (such as min/max gso sizes). Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller