Linux mainline fork with MSM8998 patches | https://mainline.space | Currently supported devices: OnePlus 5/5T, Xiaomi Mi 6, F(x)tec Pro¹ (2019 QX1000 model) & Sony Xperia XZ Premium (UNTESTED!)
Find a file
John Fastabend 2a100317c9 bpf: sockmap, add bpf_msg_apply_bytes() helper
A single sendmsg or sendfile system call can contain multiple logical
messages that a BPF program may want to read and apply a verdict. But,
without an apply_bytes helper any verdict on the data applies to all
bytes in the sendmsg/sendfile. Alternatively, a BPF program may only
care to read the first N bytes of a msg. If the payload is large say
MB or even GB setting up and calling the BPF program repeatedly for
all bytes, even though the verdict is already known, creates
unnecessary overhead.

To allow BPF programs to control how many bytes a given verdict
applies to we implement a bpf_msg_apply_bytes() helper. When called
from within a BPF program this sets a counter, internal to the
BPF infrastructure, that applies the last verdict to the next N
bytes. If the N is smaller than the current data being processed
from a sendmsg/sendfile call, the first N bytes will be sent and
the BPF program will be re-run with start_data pointing to the N+1
byte. If N is larger than the current data being processed the
BPF verdict will be applied to multiple sendmsg/sendfile calls
until N bytes are consumed.

Note1 if a socket closes with apply_bytes counter non-zero this
is not a problem because data is not being buffered for N bytes
and is sent as its received.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-03-19 21:14:39 +01:00
arch
block
certs
crypto
Documentation dt-bindings: net: dsa: marvell: describe compatibility string 2018-03-07 12:18:50 -05:00
drivers cxgb3: remove VLA usage 2018-03-07 15:55:50 -05:00
firmware
fs
include bpf: sockmap, add bpf_msg_apply_bytes() helper 2018-03-19 21:14:39 +01:00
init
ipc
kernel bpf: create tcp_bpf_ulp allowing BPF to monitor socket TX/RX data 2018-03-19 21:14:38 +01:00
lib
LICENSES
mm
net bpf: sockmap, add bpf_msg_apply_bytes() helper 2018-03-19 21:14:39 +01:00
samples samples/bpf: add example to test reading address 2018-03-08 02:22:34 +01:00
scripts
security
sound
tools tools: bpf: remove feature detection output 2018-03-16 09:23:46 +01:00
usr
virt
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS lan743x: Update MAINTAINERS to include lan743x driver 2018-03-07 11:44:42 -05:00
Makefile
README

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.