The branch main has been updated by gallatin: URL: https://cgit.FreeBSD.org/src/commit/?id=074ff8746388b3ed8581a84a7eea7b4b3e1bfe23
commit 074ff8746388b3ed8581a84a7eea7b4b3e1bfe23 Author: Andrew Gallatin <[email protected]> AuthorDate: 2026-06-15 14:20:41 +0000 Commit: Andrew Gallatin <[email protected]> CommitDate: 2026-06-23 17:00:55 +0000 iflib: handle transient errors from isc_txd_encap() Until we introduced support for nic ktls offload, all error returns from isc_txd_encap() indicated a permanent failure. Iflib remapped all those failures to ENOMEM, which was treated by the tcp stack as a permanent error and passed back to the caller. This was done to avoid creating "infinite loops" where a packet couldn't be mapped for transmit, and kept being sent over and over. Now that we have support for nic ktls offload, some ktls offload drivers may return ENOBUFS from their encap function to indicate that, for example, the ktls context may not yet be fully initialized. This needs to be treated as a transient error so that the TCP stack may re-try at a later time. To achieve this, pass the raw error back to the caller when the encap routine returns an error aside from EFBIG. Note that I audited all in-tree iflib drivers. Only ice and ixl ran return anything other than 0 from their encap, which is EFBIG. both of which are still treated as they were before. Testing with an out-of-tree ktls offload nic using iflib showed ENOMEM errors from sendmsg() before this change, and no more errors passed back to userspace after this change. Reviewed by: kp, sumit.saxena_broadcom.com Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D57550 --- sys/net/iflib.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/sys/net/iflib.c b/sys/net/iflib.c index 1af9d22db9a2..918dddc51a4f 100644 --- a/sys/net/iflib.c +++ b/sys/net/iflib.c @@ -3687,8 +3687,9 @@ defrag: remap = 1; goto defrag; } + goto defrag_failed; } - goto defrag_failed; + goto out_with_error; } /* * err can't possibly be non-zero here, so we don't neet to test it @@ -3697,13 +3698,15 @@ defrag: return (err); defrag_failed: + err = ENOMEM; txq->ift_mbuf_defrag_failed++; +out_with_error: txq->ift_map_failed++; m_freem(*m_headp); DBG_COUNTER_INC(tx_frees); *m_headp = NULL; DBG_COUNTER_INC(encap_txd_encap_fail); - return (ENOMEM); + return (err); } static void
