f198222f05
Andrey Ignatov says: ==================== v3 -> v4: * handle static key correctly for CONFIG_CGROUP_BPF=n. v2 -> v3: * place BPF logic under static key in udp_sendmsg, udpv6_sendmsg; * rebase. v1 -> v2: * return ENOTSUPP if bpf_prog rewrote IPv6-only with IPv4-mapped IPv6; * add test for IPv4-mapped IPv6 use-case; * fix build for CONFIG_CGROUP_BPF=n; * rebase. This path set adds BPF hooks for sys_sendmsg similar to existing hooks for sys_bind and sys_connect. Hooks allow to override source IP (including the case when it's set via cmsg(3)) and destination IP:port for unconnected UDP (slow path). TCP and connected UDP (fast path) are not affected. This makes UDP support complete: connected UDP is handled by sys_connect hooks, unconnected by sys_sendmsg ones. Similar to sys_connect hooks, sys_sendmsg ones can be used to make system calls such as sendmsg(2) and sendto(2) return EPERM. Please see patch 0002 for more details. ==================== Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
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.