From: Davide Caratti <dcaratti@redhat.com>
To: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org, linux-sctp@vger.kernel.org,
Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Subject: [RFC PATCH net-next 0/5] net: improve support for SCTP checksums
Date: Mon, 23 Jan 2017 17:52:41 +0100 [thread overview]
Message-ID: <cover.1485177252.git.dcaratti@redhat.com> (raw)
When NETIF_F_CSUM_MASK bits are all 0 on netdev features, validate_xmit_skb
uses skb_checksum_help to compute 16-bit, 2-complement checksum on non-GSO
skbs having ip_summed equal to CHECKSUM_PARTIAL.
This results in a systematic corruption of SCTP packets, since they need
to be checksummed with crc32c. Moreover, this is done regardless the value
of NETIF_F_SCTP_CRC, so any chance to offload crc32c computation on the
NIC is lost. Finally, even when at least one bit in NETIF_F_CSUM_MASK is
set on netdev features, validate_xmit_skb skips checksum computation - but
then most NIC drivers can only call skb_checksum_help if their HW can't
offload the checksum computation. Depending on the driver code, this
results in wrong handling of SCTP, leading to:
- packet being dropped
- packet being transmitted with identically-zero checksum
- packet being transmitted with 2-complement checksum instead of crc32c
This series tries to address the above issue, by providing:
- the possibility to compute crc32c on skbs in Linux net core [patch 1]
- skb_sctp_csum_help, a function sharing common code with the original
skb_checksum_help, that performs SW checksumming for skbs using crc32c
[patch 2 and patch 3]
- skb_csum_hwoffload_help, called by validate xmit skb to perform SW
checksumming using the correct algorithm based on the value of IP
protocol number and netdev features bitmask [patch 4]
- an update to Linux documentation [patch 5]
Davide Caratti (5):
skbuff: add stub to help computing crc32c on SCTP packets
net: split skb_checksum_help
net: introduce skb_sctp_csum_help
net: more accurate checksumming in validate_xmit_skb
Documentation: add description of skb_sctp_csum_help
Documentation/networking/checksum-offloads.txt | 9 +-
include/linux/netdevice.h | 1 +
include/linux/skbuff.h | 5 +-
net/core/dev.c | 132 +++++++++++++++++++++----
net/core/skbuff.c | 20 ++++
net/sctp/offload.c | 7 ++
6 files changed, 151 insertions(+), 23 deletions(-)
--
2.7.4
next reply other threads:[~2017-01-23 16:59 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-23 16:52 Davide Caratti [this message]
2017-01-23 16:52 ` [RFC PATCH net-next 1/5] skbuff: add stub to help computing crc32c on SCTP packets Davide Caratti
2017-01-23 16:52 ` [RFC PATCH net-next 2/5] net: split skb_checksum_help Davide Caratti
2017-01-23 20:59 ` Tom Herbert
2017-01-24 16:35 ` David Laight
2017-02-02 15:07 ` Davide Caratti
2017-02-02 16:55 ` David Laight
2017-02-02 18:08 ` Tom Herbert
2017-02-27 13:39 ` Davide Caratti
2017-02-27 15:11 ` Tom Herbert
2017-02-28 10:31 ` Davide Caratti
2017-02-28 10:32 ` [PATCH RFC net-next v2 1/4] skbuff: add stub to help computing crc32c on SCTP packets Davide Caratti
2017-02-28 10:32 ` [PATCH RFC net-next v2 2/4] net: introduce skb_sctp_csum_help Davide Caratti
2017-02-28 10:32 ` [PATCH RFC net-next v2 3/4] net: more accurate checksumming in validate_xmit_skb Davide Caratti
2017-02-28 19:50 ` Tom Herbert
2017-02-28 10:32 ` [PATCH RFC net-next v2 4/4] Documentation: update notes on checksum offloading Davide Caratti
2017-02-28 22:46 ` [PATCH RFC net-next v2 1/4] skbuff: add stub to help computing crc32c on SCTP packets Alexander Duyck
2017-03-01 3:17 ` Tom Herbert
2017-03-01 10:53 ` David Laight
2017-03-06 21:51 ` Davide Caratti
2017-03-07 18:06 ` Alexander Duyck
2017-03-18 13:17 ` Davide Caratti
2017-03-18 22:35 ` Tom Herbert
2017-04-07 14:16 ` [PATCH RFC net-next v3 0/7] improve CRC32c in the forwarding path Davide Caratti
2017-04-07 14:16 ` [PATCH RFC net-next v3 1/7] skbuff: add stub to help computing crc32c on SCTP packets Davide Caratti
2017-04-07 14:16 ` [PATCH RFC net-next v3 2/7] net: introduce skb_crc32c_csum_help Davide Caratti
2017-04-07 14:16 ` [PATCH RFC net-next v3 3/7] sk_buff: remove support for csum_bad in sk_buff Davide Caratti
2017-04-07 14:16 ` [PATCH RFC net-next v3 4/7] net: use skb->csum_algo to identify packets needing crc32c Davide Caratti
2017-04-07 15:43 ` Tom Herbert
2017-04-07 17:29 ` Davide Caratti
2017-04-07 18:11 ` Tom Herbert
2017-04-13 10:36 ` Davide Caratti
2017-04-20 13:38 ` [PATCH RFC net-next v4 0/7] net: improve support for SCTP checksums Davide Caratti
2017-04-20 13:38 ` [PATCH RFC net-next v4 1/7] skbuff: add stub to help computing crc32c on SCTP packets Davide Caratti
2017-04-20 13:38 ` [PATCH RFC net-next v4 2/7] net: introduce skb_crc32c_csum_help Davide Caratti
2017-04-27 12:29 ` Marcelo Ricardo Leitner
2017-04-20 13:38 ` [PATCH RFC net-next v4 3/7] sk_buff: remove support for csum_bad in sk_buff Davide Caratti
2017-04-27 1:34 ` [sk_buff] 95510aef27: BUG:Bad_page_state_in_process kernel test robot
2017-04-29 20:21 ` [PATCH RFC net-next v4 3/7] sk_buff: remove support for csum_bad in sk_buff Tom Herbert
2017-04-20 13:38 ` [PATCH RFC net-next v4 4/7] net: use skb->csum_not_inet to identify packets needing crc32c Davide Caratti
2017-04-29 20:18 ` Tom Herbert
2017-04-20 13:38 ` [PATCH RFC net-next v4 5/7] net: more accurate checksumming in validate_xmit_skb() Davide Caratti
2017-04-20 13:38 ` [PATCH RFC net-next v4 6/7] openvswitch: more accurate checksumming in queue_userspace_packet() Davide Caratti
2017-04-20 13:38 ` [PATCH RFC net-next v4 7/7] sk_buff.h: improve description of CHECKSUM_{COMPLETE,UNNECESSARY} Davide Caratti
2017-04-29 20:20 ` Tom Herbert
2017-04-27 12:41 ` [PATCH RFC net-next v4 0/7] net: improve support for SCTP checksums Marcelo Ricardo Leitner
2017-04-07 14:16 ` [PATCH RFC net-next v3 5/7] net: more accurate checksumming in validate_xmit_skb() Davide Caratti
2017-04-07 14:16 ` [PATCH RFC net-next v3 6/7] openvswitch: more accurate checksumming in queue_userspace_packet() Davide Caratti
2017-04-07 14:16 ` [PATCH RFC net-next v3 7/7] sk_buff.h: improve description of CHECKSUM_{COMPLETE,UNNECESSARY} Davide Caratti
2017-01-23 16:52 ` [RFC PATCH net-next 3/5] net: introduce skb_sctp_csum_help Davide Caratti
2017-01-23 16:52 ` [RFC PATCH net-next 4/5] net: more accurate checksumming in validate_xmit_skb Davide Caratti
2017-01-23 16:52 ` [RFC PATCH net-next 5/5] Documentation: add description of skb_sctp_csum_help Davide Caratti
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