were copied to the buffer supplied by the user.
Also fix getrandom() if Linuxulator modules are built without the kernel.
PR: 219464
Submitted by: Maciej Pasternacki
Reported by: Maciej Pasternacki
MFC after: 1 week
patm(4) devices.
Maintaining an address family and framework has real costs when we make
infrastructure improvements. In the case of NATM we support no devices
manufactured in the last 20 years and some will not even work in modern
motherboards (some newer devices that patm(4) could be updated to
support apparently exist, but we do not currently have support).
With this change, support remains for some netgraph modules that don't
require NATM support code. It is unclear if all these should remain,
though ng_atmllc certainly stands alone.
Note well: FreeBSD 11 supports NATM and will continue to do so until at
least September 30, 2021. Improvements to the code in FreeBSD 11 are
certainly welcome.
Reviewed by: philip
Approved by: harti
compile options. Remove doxygen pointers to now deleted files. Remove
EISA and VME as examples in bus_space.9.
Retained EISA mode code for IO PIC and MPTABLES because that's not
EISA bus, per se, and some people have abused EISA to mean "EISA-like
behavior as opposed to ISA" rather than using it for EISA add-in
cards.
Relnotes: yes
- Add RATELIMIT kernel configuration keyword which must be set to
enable the new functionality.
- Add support for hardware driven, Receive Side Scaling, RSS aware, rate
limited sendqueues and expose the functionality through the already
established SO_MAX_PACING_RATE setsockopt(). The API support rates in
the range from 1 to 4Gbytes/s which are suitable for regular TCP and
UDP streams. The setsockopt(2) manual page has been updated.
- Add rate limit function callback API to "struct ifnet" which supports
the following operations: if_snd_tag_alloc(), if_snd_tag_modify(),
if_snd_tag_query() and if_snd_tag_free().
- Add support to ifconfig to view, set and clear the IFCAP_TXRTLMT
flag, which tells if a network driver supports rate limiting or not.
- This patch also adds support for rate limiting through VLAN and LAGG
intermediate network devices.
- How rate limiting works:
1) The userspace application calls setsockopt() after accepting or
making a new connection to set the rate which is then stored in the
socket structure in the kernel. Later on when packets are transmitted
a check is made in the transmit path for rate changes. A rate change
implies a non-blocking ifp->if_snd_tag_alloc() call will be made to the
destination network interface, which then sets up a custom sendqueue
with the given rate limitation parameter. A "struct m_snd_tag" pointer is
returned which serves as a "snd_tag" hint in the m_pkthdr for the
subsequently transmitted mbufs.
2) When the network driver sees the "m->m_pkthdr.snd_tag" different
from NULL, it will move the packets into a designated rate limited sendqueue
given by the snd_tag pointer. It is up to the individual drivers how the rate
limited traffic will be rate limited.
3) Route changes are detected by the NIC drivers in the ifp->if_transmit()
routine when the ifnet pointer in the incoming snd_tag mismatches the
one of the network interface. The network adapter frees the mbuf and
returns EAGAIN which causes the ip_output() to release and clear the send
tag. Upon next ip_output() a new "snd_tag" will be tried allocated.
4) When the PCB is detached the custom sendqueue will be released by a
non-blocking ifp->if_snd_tag_free() call to the currently bound network
interface.
Reviewed by: wblock (manpages), adrian, gallatin, scottl (network)
Differential Revision: https://reviews.freebsd.org/D3687
Sponsored by: Mellanox Technologies
MFC after: 3 months
KERNBUILDDIR. Come up with some sensible defaults (though listing them
in kmod.mk may be unwise -- we have no easy way to know what are the
best sensible defaults for everything so we just catch the big stuff).
Append SRCS.${opt} for each option in KERN_OPTS to SRCS to allow easy
conditional compilation. Append any notion of KERN_OPTS_EXTRA to the
list of kernel opts.
Differential Revision: https://reviews.freebsd.org/D1530
