4592ee7f52
These two sysctls were added because the hardcoded defaults (2 minutes, tcp, 30 seconds, udp) turned out to be too low for some setups. They appeared in 5.14-rc1 so it should be fine to remove it again. Marcelo convinced me that there should be no difference between a flow that was offloaded vs. a flow that was not wrt. timeout handling. Thus the default is changed to those for TCP established and UDP stream, 5 days and 120 seconds, respectively. Marcelo also suggested to account for the timeout value used for the offloading, this avoids increase beyond the value in the conntrack-sysctl and will also instantly expire the conntrack entry with altered sysctls. Example: nf_conntrack_udp_timeout_stream=60 nf_flowtable_udp_timeout=60 This will remove offloaded udp flows after one minute, rather than two. An earlier version of this patch also cleared the ASSURED bit to allow nf_conntrack to evict the entry via early_drop (i.e., table full). However, it looks like we can safely assume that connection timed out via HW is still in established state, so this isn't needed. Quoting Oz: [..] the hardware sends all packets with a set FIN flags to sw. [..] Connections that are aged in hardware are expected to be in the established state. In case it turns out that back-to-sw-path transition can occur for 'dodgy' connections too (e.g., one side disappeared while software-path would have been in RETRANS timeout), we can adjust this later. Cc: Oz Shlomo <ozsh@nvidia.com> Cc: Paul Blakey <paulb@nvidia.com> Suggested-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Florian Westphal <fw@strlen.de> Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Reviewed-by: Oz Shlomo <ozsh@nvidia.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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.
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.