QUIC requires end to end encryption of the data. The application usually
prepares the data in clear text, encrypts and calls send() which implies
multiple copies of the data before the packets hit the networking stack.
Similar to kTLS, QUIC kernel offload of cryptography reduces the memory
pressure by reducing the number of copies.
The scope of kernel support is limited to the symmetric cryptography,
leaving the handshake to the user space library. For QUIC in particular,
the application packets that require symmetric cryptography are the 1RTT
packets with short headers. Kernel will encrypt the application packets
on transmission and decrypt on receive. This series implements Tx only,
because in QUIC server applications Tx outweighs Rx by orders of
magnitude.
Supporting the combination of QUIC and GSO requires the application to
correctly place the data and the kernel to correctly slice it. The
encryption process appends an arbitrary number of bytes (tag) to the end
of the message to authenticate it. The GSO value should include this
overhead, the offload would then subtract the tag size to parse the
input on Tx before chunking and encrypting it.
With the kernel cryptography, the buffer copy operation is conjoined
with the encryption operation. The memory bandwidth is reduced by 5-8%.
When devices supporting QUIC encryption in hardware come to the market,
we will be able to free further 7% of CPU utilization which is used
today for crypto operations.
Adel Abouchaev (6):
Documentation on QUIC kernel Tx crypto.
Define QUIC specific constants, control and data plane structures
Add UDP ULP operations, initialization and handling prototype
functions.
Implement QUIC offload functions
Add flow counters and Tx processing error counter
Add self tests for ULP operations, flow setup and crypto tests
Documentation/networking/quic.rst | 176 +++
include/net/inet_sock.h | 2 +
include/net/netns/mib.h | 3 +
include/net/quic.h | 59 +
include/net/snmp.h | 6 +
include/net/udp.h | 33 +
include/uapi/linux/quic.h | 61 +
include/uapi/linux/snmp.h | 11 +
include/uapi/linux/udp.h | 4 +
net/Kconfig | 1 +
net/Makefile | 1 +
net/ipv4/Makefile | 3 +-
net/ipv4/udp.c | 14 +
net/ipv4/udp_ulp.c | 190 ++++
net/quic/Kconfig | 16 +
net/quic/Makefile | 8 +
net/quic/quic_main.c | 1446 ++++++++++++++++++++++++
net/quic/quic_proc.c | 45 +
tools/testing/selftests/net/.gitignore | 1 +
tools/testing/selftests/net/Makefile | 2 +-
tools/testing/selftests/net/quic.c | 1024 +++++++++++++++++
tools/testing/selftests/net/quic.sh | 45 +
22 files changed, 3149 insertions(+), 2 deletions(-)
create mode 100644 Documentation/networking/quic.rst
create mode 100644 include/net/quic.h
create mode 100644 include/uapi/linux/quic.h
create mode 100644 net/ipv4/udp_ulp.c
create mode 100644 net/quic/Kconfig
create mode 100644 net/quic/Makefile
create mode 100644 net/quic/quic_main.c
create mode 100644 net/quic/quic_proc.c
create mode 100644 tools/testing/selftests/net/quic.c
create mode 100755 tools/testing/selftests/net/quic.sh
--
2.30.2
