This adds support for ifnet (NIC) KTLS using Chelsio T6 adapters.
Unlike the TOE-based KTLS in r353328, NIC TLS works with non-TOE
connections.
NIC KTLS on T6 is not able to use the normal TSO (LSO) path to segment
the encrypted TLS frames output by the crypto engine. Instead, the
TOE is placed into a special setup to permit "dummy" connections to be
associated with regular sockets using KTLS. This permits using the
TOE to segment the encrypted TLS records. However, this approach does
have some limitations:
1) Regular TOE sockets cannot be used when the TOE is in this special
mode. One can use either TOE and TOE-based KTLS or NIC KTLS, but
not both at the same time.
2) In NIC KTLS mode, the TOE is only able to accept a per-connection
timestamp offset that varies in the upper 4 bits. Put another way,
only connections whose timestamp offset has the 28 lower bits
cleared can use NIC KTLS and generate correct timestamps. The
driver will refuse to enable NIC KTLS on connections with a
timestamp offset with any of the lower 28 bits set. To use NIC
KTLS, users can either disable TCP timestamps by setting the
net.inet.tcp.rfc1323 sysctl to 0, or apply a local patch to the
tcp_new_ts_offset() function to clear the lower 28 bits of the
generated offset.
3) Because the TCP segmentation relies on fields mirrored in a TCB in
the TOE, not all fields in a TCP packet can be sent in the TCP
segments generated from a TLS record. Specifically, for packets
containing TCP options other than timestamps, the driver will
inject an "empty" TCP packet holding the requested options (e.g. a
SACK scoreboard) along with the segments from the TLS record.
These empty TCP packets are counted by the
dev.cc.N.txq.M.kern_tls_options sysctls.
Unlike TOE TLS which is able to buffer encrypted TLS records in
on-card memory to handle retransmits, NIC KTLS must re-encrypt TLS
records for retransmit requests as well as non-retransmit requests
that do not include the start of a TLS record but do include the
trailer. The T6 NIC KTLS code tries to optimize some of the cases for
requests to transmit partial TLS records. In particular it attempts
to minimize sending "waste" bytes that have to be given as input to
the crypto engine but are not needed on the wire to satisfy mbufs sent
from the TCP stack down to the driver.
TCP packets for TLS requests are broken down into the following
classes (with associated counters):
- Mbufs that send an entire TLS record in full do not have any waste
bytes (dev.cc.N.txq.M.kern_tls_full).
- Mbufs that send a short TLS record that ends before the end of the
trailer (dev.cc.N.txq.M.kern_tls_short). For sockets using AES-CBC,
the encryption must always start at the beginning, so if the mbuf
starts at an offset into the TLS record, the offset bytes will be
"waste" bytes. For sockets using AES-GCM, the encryption can start
at the 16 byte block before the starting offset capping the waste at
15 bytes.
- Mbufs that send a partial TLS record that has a non-zero starting
offset but ends at the end of the trailer
(dev.cc.N.txq.M.kern_tls_partial). In order to compute the
authentication hash stored in the trailer, the entire TLS record
must be sent as input to the crypto engine, so the bytes before the
offset are always "waste" bytes.
In addition, other per-txq sysctls are provided:
- dev.cc.N.txq.M.kern_tls_cbc: Count of sockets sent via this txq
using AES-CBC.
- dev.cc.N.txq.M.kern_tls_gcm: Count of sockets sent via this txq
using AES-GCM.
- dev.cc.N.txq.M.kern_tls_fin: Count of empty FIN-only packets sent to
compensate for the TOE engine not being able to set FIN on the last
segment of a TLS record if the TLS record mbuf had FIN set.
- dev.cc.N.txq.M.kern_tls_records: Count of TLS records sent via this
txq including full, short, and partial records.
- dev.cc.N.txq.M.kern_tls_octets: Count of non-waste bytes (TLS header
and payload) sent for TLS record requests.
- dev.cc.N.txq.M.kern_tls_waste: Count of waste bytes sent for TLS
record requests.
To enable NIC KTLS with T6, set the following tunables prior to
loading the cxgbe(4) driver:
hw.cxgbe.config_file=kern_tls
hw.cxgbe.kern_tls=1
Reviewed by: np
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D21962
These filters reside in the card's memory instead of its TCAM and can be
configured via a new "hashfilter" subcommand in cxgbetool. Hash and
normal TCAM filters can be used together. The hardware does an
exact-match of packet fields for hash filters, unlike the masked match
performed for TCAM filters. Any T5/T6 card with memory can support at
least half a million hash filters. The sample config file with the
driver configures 512K of these, it is possible to double this to 1
million+ in some cases.
The chip does an exact-match of fields of incoming datagrams with hash
filters and performs the action configured for the filter if it matches.
The fields to match are specified in a "filter mask" in the firmware
config file. The filter mask always includes the 5-tuple (sip, dip,
sport, dport, ipproto). It can, optionally, also include any subset of
the filter mode (see filterMode and filterMask in the firmware config
file).
For example:
filterMode = fragmentation, mpshittype, protocol, vlan, port, fcoe
filterMask = protocol, port, vlan
Exact values of the 5-tuple, the physical port, and VLAN tag would have
to be provided while setting up a hash filter with the chip
configuration above.
Hash filters support all actions supported by TCAM filters. A packet
that hits a hash filter can be dropped, let through (with optional
steering to a specific queue or RSS region), switched out of another
port (with optional L2 rewrite of DMAC, SMAC, VLAN tag), or get NAT'ed.
(Support for some of these will show up in the driver in a follow-up
commit very shortly).
Sponsored by: Chelsio Communications
Reserve 3b in the 14b atid to identify the owner and use it to dispatch
the CPL. This allows all CPLs that use an atid to be used as shared
CPLs, although ACT_OPEN_RPL is the only one being converted in this
revision.
Sponsored by: Chelsio Communications
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
cannot be sent to the chip because a prerequisite L2 resolution
failed.
Submitted by: Hariprasad at chelsio dot com (original version)
MFC after: 2 weeks.
includes support for the NIC and TOE features of the 40G, 10G, and
1G/100M cards based on the T5.
The ASIC is mostly backward compatible with the Terminator 4 so cxgbe(4)
has been updated instead of writing a brand new driver. T5 cards will
show up as cxl (short for cxlgb) ports attached to the t5nex bus driver.
Sponsored by: Chelsio
Basically, this is automatic rx zero copy when feasible. TCP payload is
DMA'd directly into the userspace buffer described by the uio submitted
in soreceive by an application.
- Works with sockets that are being handled by the TCP offload engine
of a T4 chip (you need t4_tom.ko module loaded after cxgbe, and an
"ifconfig +toe" on the cxgbe interface).
- Does not require any modification to the application.
- Not enabled by default. Use hw.t4nex.<X>.toe.ddp="1" to enable it.
