introduced with r261242. The useful and expected soisconnected()
call is done in tcp_do_segment().
Has been found as part of unrelated PR:212920 investigation.
Improve slightly (~2%) the maximum number of TCP accept per second.
Tested by: kevin.bowling_kev009.com, jch
Approved by: gnn, hiren
MFC after: 1 week
Sponsored by: Verisign, Inc
Differential Revision: https://reviews.freebsd.org/D8072
loss event but not use or obay the recommendations i.e. values set by it in some
cases.
Here is an attempt to solve that confusion by following relevant RFCs/drafts.
Stack only sets congestion window/slow start threshold values when there is no
CC module availalbe to take that action. All CC modules are inspected and
updated when needed to take appropriate action on loss.
tcp_stacks/fastpath module has been updated to adapt these changes.
Note: Probably, the most significant change would be to not bring congestion
window down to 1MSS on a loss signaled by 3-duplicate acks and letting
respective CC decide that value.
In collaboration with: Matt Macy <mmacy at nextbsd dot org>
Discussed on: transport@ mailing list
Reviewed by: jtl
MFC after: 1 month
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D8225
In r304435, ip_output() was changed to use the result of the route
lookup to decide whether the outgoing packet was a broadcast or
not. This introduced a regression on interfaces where
IFF_BROADCAST was not set (e.g. point-to-point links), as the
algorithm could incorrectly treat the destination address as a
broadcast address, and ip_output() would subsequently drop the
packet as broadcasting on a non-IFF_BROADCAST interface is not
allowed.
Differential Revision: https://reviews.freebsd.org/D8303
Reviewed by: jtl
Reported by: ambrisko
MFC after: 2 weeks
X-MFC-With: r304435
Sponsored by: Dell EMC Isilon
handling. Ensure that:
* Protocol unreachable errors are handled by indicating ECONNREFUSED
to the TCP user for both IPv4 and IPv6. These were ignored for IPv6.
* Communication prohibited errors are handled by indicating ECONNREFUSED
to the TCP user for both IPv4 and IPv6. These were ignored for IPv6.
* Hop Limited exceeded errors are handled by indicating EHOSTUNREACH
to the TCP user for both IPv4 and IPv6.
For IPv6 the TCP connected was dropped but errno wasn't set.
Reviewed by: gallatin, rrs
MFC after: 1 month
Sponsored by: Netflix
Differential Revision: 7904
after having been dropped.
This fixes enforces in_pcbdrop() logic in tcp_input():
"in_pcbdrop() is used by TCP to mark an inpcb as unused and avoid future packet
delivery or event notification when a socket remains open but TCP has closed."
PR: 203175
Reported by: Palle Girgensohn, Slawa Olhovchenkov
Tested by: Slawa Olhovchenkov
Reviewed by: Slawa Olhovchenkov
Approved by: gnn, Slawa Olhovchenkov
Differential Revision: https://reviews.freebsd.org/D8211
MFC after: 1 week
Sponsored by: Verisign, inc
to at least 64.
This is still just a coverup to avoid kernel panic and not an actual fix.
PR: 213232
Reviewed by: glebius
MFC after: 1 week
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D8272
Also renamed some tfo labels and added/reworked comments for clarity.
Based on an initial patch from jtl.
PR: 213424
Reviewed by: jtl
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D8235
compile when that option is configured. In tcp_destroy(), the error
variable is now only used in code enclosed in an '#ifdef TCP_HHOOK' block.
This broke the build for VNET images.
Enclose the error variable itself in an #ifdef block.
Submitted by: Shawn Webb <shawn.webb at hardenedbsd.org>
Reported by: Shawn Webb <shawn.webb at hardenedbsd.org>
PointyHat to: jtl
received on a TCP session that has entered the ESTABLISHED state. This
results in a lot of calls to reset the keepalive timer.
This patch changes the behavior so we set the keepalive timer for the
keepalive idle time (TP_KEEPIDLE). When the keepalive timer fires, it will
first check to see if the session has been idle for TP_KEEPIDLE ticks. If
not, it will reschedule the keepalive timer for the time the session will
have been idle for TP_KEEPIDLE ticks.
For a session with regular communication, the keepalive timer should fire
approximately once every TP_KEEPIDLE ticks. For sessions with irregular
communication, the keepalive timer might fire more often. But, the
disruption from a periodic keepalive timer should be less than the regular
cost of resetting the keepalive timer on every packet.
(FWIW, this change saved approximately 1.73% of the busy CPU cycles on a
particular test system with a heavy TCP output load. Of course, the
actual impact is very specific to the particular hardware and workload.)
Reviewed by: gallatin, rrs
MFC after: 2 weeks
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D8243
the TCP_RFC7413 kernel option. This change removes those few instructions
from the packet processing path.
While not strictly necessary, for the sake of consistency, I applied the
new IS_FASTOPEN macro to all places in the packet processing path that
used the (t_flags & TF_FASTOPEN) check.
Reviewed by: hiren
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D8219
TCPCB, it checks (so->so_options & SO_ACCEPTCONN) to determine whether or
not the socket is a listening socket. However, this causes the code to
access a different cacheline. If we first check if the socket is in the
LISTEN state, we can avoid accessing so->so_options when processing packets
received for ESTABLISHED sessions.
If INVARIANTS is defined, the code still needs to access both variables to
check that so->so_options is consistent with the state.
Reviewed by: gallatin
MFC after: 1 week
Sponsored by: Netflix
to add actions that run when a TCP frame is sent or received on a TCP
session in the ESTABLISHED state. In the base tree, this functionality is
only used for the h_ertt module, which is used by the cc_cdg, cc_chd, cc_hd,
and cc_vegas congestion control modules.
Presently, we incur overhead to check for hooks each time a TCP frame is
sent or received on an ESTABLISHED TCP session.
This change adds a new compile-time option (TCP_HHOOK) to determine whether
to include the hhook(9) framework for TCP. To retain backwards
compatibility, I added the TCP_HHOOK option to every configuration file that
already defined "options INET". (Therefore, this patch introduces no
functional change. In order to see a functional difference, you need to
compile a custom kernel without the TCP_HHOOK option.) This change will
allow users to easily exclude this functionality from their kernel, should
they wish to do so.
Note that any users who use a custom kernel configuration and use one of the
congestion control modules listed above will need to add the TCP_HHOOK
option to their kernel configuration.
Reviewed by: rrs, lstewart, hiren (previous version), sjg (makefiles only)
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D8185
This change extends the nd6 lock to protect the ND prefix list as well
as the list of advertising routers associated with each prefix. To handle
cases where the nd6 lock must be dropped while iterating over either the
prefix or default router lists, a generation counter is used to track
modifications to the lists. Additionally, a new mutex is used to serialize
prefix on-link/off-link transitions. This mutex must be acquired before
the nd6 lock and is held while updating the routing table in
nd6_prefix_onlink() and nd6_prefix_offlink().
Reviewed by: ae, tuexen (SCTP bits)
Tested by: Jason Wolfe <jason@llnw.com>,
Larry Rosenman <ler@lerctr.org>
MFC after: 2 months
Differential Revision: https://reviews.freebsd.org/D8125
In the persist case, take the SYN and FIN flags into account when updating
the sequence space sent.
Reviewed by: gnn
MFC after: 2 weeks
Sponsored by: Juniper Networks, Netflix
Differential Revision: https://reviews.freebsd.org/D7075
Tested by: Limelight, Netflix
A single gratuitous ARP (GARP) is always transmitted when an IPv4
address is added to an interface, and that is usually sufficient.
However, in some circumstances, such as when a shared address is
passed between cluster nodes, this single GARP may occasionally be
dropped or lost. This can lead to neighbors on the network link
working with a stale ARP cache and sending packets destined for
that address to the node that previously owned the address, which
may not respond.
To avoid this situation, GARP retransmissions can be enabled by setting
the net.link.ether.inet.garp_rexmit_count sysctl to a value greater
than zero. The setting represents the maximum number of retransmissions.
The interval between retransmissions is calculated using an exponential
backoff algorithm, doubling each time, so the retransmission intervals
are: {1, 2, 4, 8, 16, ...} (seconds).
Due to the exponential backoff algorithm used for the interval
between GARP retransmissions, the maximum number of retransmissions
is limited to 16 for sanity. This limit corresponds to a maximum
interval between retransmissions of 2^16 seconds ~= 18 hours.
Increasing this limit is possible, but sending out GARPs spaced
days apart would be of little use.
Submitted by: David A. Bright <david.a.bright@dell.com>
MFC after: 1 month
Relnotes: yes
Sponsored by: Dell EMC
Differential Revision: https://reviews.freebsd.org/D7695
is NULL and the function jumps to the "release:" label.
For this case, the "inp" was write locked, but the code attempted to
read unlock it. This patch fixes the problem.
This case could occur for NFS over UDP mounts, where the server was
down for a few minutes under certain circumstances.
Reported by: bde
Tested by: bde
Reviewed by: gnn
MFC after: 2 weeks
during testing of network related changes where cached entries may pollute your
results, or during known congestion events where you don't want to unfairly
penalize hosts.
Prior to r232346 this would have meant you would break any connection with a sub
1500 MTU, as the hostcache was authoritative. All entries as they stand today
should simply be used to pre populate values for efficiency.
Submitted by: Jason Wolfe (j at nitrology dot com)
Reviewed by: rwatson, sbruno, rrs , bz (earlier version)
MFC after: 2 weeks
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D6198
Restructure code slightly to save ip_tos bits earlier. Fix the bug
where the ip_tos field is zeroed out before assigning to the iptos
variable. Restore the ip_tos and ip_ver fields only if they have
been zeroed during the pseudo-header checksum calculation.
Reviewed by: cem, gnn, hiren
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D8053
As a side effect of r261242 when using accept_filter the
first call to soisconnected() is done earlier in tcp_input()
instead of tcp_do_segment() context. Restore the expected behaviour.
Note: This call to soisconnected() seems to be extraneous in all
cases (with or without accept_filter). Will be addressed in a
separate commit.
PR: 212920
Reported by: Alexey
Tested by: Alexey, jch
Sponsored by: Verisign, Inc.
MFC after: 1 week
While here, prefer if_addrhead (FreeBSD) to if_addrlist (BSD compat) naming
for the interface address list in sctp_bsd_addr.c
Reviewed by: tuexen
Differential Revision: https://reviews.freebsd.org/D8051
Descriptor returned by accept(2) should inherits capabilities rights from
the listening socket.
PR: 201052
Reviewed by: emaste, jonathan
Discussed with: many
Differential Revision: https://reviews.freebsd.org/D7724
There were two bugs:
* There was an accounting bug resulting in reporting a too small a_rwnd.
* There are a bug when abandoning messages in the reassembly queue.
MFC after: 4 weeks
* TCP_KEEPINIT
* TCP_KEEPINTVL
* TCP_KEEPIDLE
* TCP_KEEPCNT
always always report the values currently used when getsockopt()
is used. This wasn't the case when the sysctl-inherited default
values where used.
Ensure that the IPPROTO_TCP level socket option TCP_INFO has the
TCPI_OPT_ECN flag set in the tcpi_options field when ECN support
has been negotiated successfully.
Reviewed by: rrs, jtl, hiren
MFC after: 1 month
Differential Revision: 7833
warning:
sys/netinet/igmp.c:546:21: error: implicit conversion from 'int' to 'char' changes value from 148 to -108 [-Werror,-Wconstant-conversion]
p->ipopt_list[0] = IPOPT_RA; /* Router Alert Option */
~ ^~~~~~~~
sys/netinet/ip.h:153:19: note: expanded from macro 'IPOPT_RA'
#define IPOPT_RA 148 /* router alert */
^~~
This is because ipopt_list is an array of char, so IPOPT_RA is wrapped
to a negative value. It would be nice to change ipopt_list to an array
of u_char, but it changes the signature of the public struct ipoption,
so add an explicit cast to suppress the warning.
Reviewed by: imp
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D7777
can be in after receiving a FIN.
FWIW, NetBSD has this change for quite some time.
This has been tested at Netflix and Limelight in production traffic.
Reported by: Sam Kumar <samkumar99 at gmail.com> on transport@
Reviewed by: rrs
MFC after: 4 weeks
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D7475
I-FORWARD-TSN chunk before any DATA or I-DATA chunk.
Thanks to Julian Cordes for finding this problem and prividing
packetdrill scripts to reporduce the issue.
MFC after: 3 days
tso_segsz pkthdr field during RX processing, and use the information in TCP for
more correct accounting and as a congestion control input. This is only a start,
and an audit of other uses for the data is left as future work.
Reviewed by: gallatin, rrs
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D7564
r304436 attempted to optimize the handling of incoming UDP packet by only
making an expensive call to in_broadcast() if the mbuf was marked as an
broadcast packet. Unfortunately, this cannot work in the case of point-to-
point L2 protocols like PPP, which have no notion of "broadcast".
Discussions on how to properly fix r304436 are ongoing, but in the meantime
disable the optimization to ensure that no existing network setups are broken.
Reported by: bms
First, keep a ref count on the stcb after looking it up, as
done in the other lookup cases.
Second, before looking again at sp, ensure that it is not
freed, because the assoc is about to be freed.
MFC after: 3 days
The default value of the tunable introduced in r304436 couldn't be
effectively overrided on VIMAGE kernels, because instead of being
accessed via the appropriate VNET() accessor macro, it was accessed
via the VNET_NAME() macro, which resolves to the (should-be) read-only
master template of initial values of per-VNET data. Hence, while the
value of udp_require_l2_bcast could be altered on per-VNET basis, the
code in udp_input() would ignore it as it would always read the default
value (one) from the VNET master template.
Silence from: rstone
in_broadcast() was iterating over the ifnet address list without
first taking an IF_ADDR_RLOCK. This could cause a panic if a
concurrent operation modified the list.
Reviewed by: bz
MFC after: 2 months
Sponsored by: EMC / Isilon Storage Division
Differential Revision: https://reviews.freebsd.org/D7227
in_broadcast() can be quite expensive, so skip calling it if the
incoming mbuf wasn't sent to a broadcast L2 address in the first
place.
Reviewed by: gnn
MFC after: 2 months
Sponsored by: EMC / Isilon Storage Division
Differential Revision: https://reviews.freebsd.org/D7309
For almost every packet that is transmitted through ip_output(),
a call to in_broadcast() was made to decide if the destination
IP was a broadcast address. in_broadcast() iterates over the
ifnet's address to find a source IP matching the subnet of the
destination IP, and then checks if the IP is a broadcast in that
subnet.
This is completely redundant as we have already performed the
route lookup, so the source IP is already known. Just use that
address to directly check whether the destination IP is a
broadcast address or not.
MFC after: 2 months
Sponsored By: EMC / Isilon Storage Division
Differential Revision: https://reviews.freebsd.org/D7266
alternate TCP stack in other then the closed state (pre-listen/connect).
The idea is that *if* that is supported by the alternate stack, it
is asked if its ok to switch. If it approves the "handoff" then we
allow the switch to happen. Also the fini() function now gets a flag
to tell if you are switching away *or* the tcb is destroyed. The
init() call into the alternate stack is moved to the end so the
tcb is more fully formed before the init transpires.
Sponsored by: Netflix Inc.
Differential Revision: D6790
The module works together with ipfw(4) and implemented as its external
action module.
Stateless NAT64 registers external action with name nat64stl. This
keyword should be used to create NAT64 instance and to address this
instance in rules. Stateless NAT64 uses two lookup tables with mapped
IPv4->IPv6 and IPv6->IPv4 addresses to perform translation.
A configuration of instance should looks like this:
1. Create lookup tables:
# ipfw table T46 create type addr valtype ipv6
# ipfw table T64 create type addr valtype ipv4
2. Fill T46 and T64 tables.
3. Add rule to allow neighbor solicitation and advertisement:
# ipfw add allow icmp6 from any to any icmp6types 135,136
4. Create NAT64 instance:
# ipfw nat64stl NAT create table4 T46 table6 T64
5. Add rules that matches the traffic:
# ipfw add nat64stl NAT ip from any to table(T46)
# ipfw add nat64stl NAT ip from table(T64) to 64:ff9b::/96
6. Configure DNS64 for IPv6 clients and add route to 64:ff9b::/96
via NAT64 host.
Stateful NAT64 registers external action with name nat64lsn. The only
one option required to create nat64lsn instance - prefix4. It defines
the pool of IPv4 addresses used for translation.
A configuration of instance should looks like this:
1. Add rule to allow neighbor solicitation and advertisement:
# ipfw add allow icmp6 from any to any icmp6types 135,136
2. Create NAT64 instance:
# ipfw nat64lsn NAT create prefix4 A.B.C.D/28
3. Add rules that matches the traffic:
# ipfw add nat64lsn NAT ip from any to A.B.C.D/28
# ipfw add nat64lsn NAT ip6 from any to 64:ff9b::/96
4. Configure DNS64 for IPv6 clients and add route to 64:ff9b::/96
via NAT64 host.
Obtained from: Yandex LLC
Relnotes: yes
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D6434
The current in_pcb.h includes route.h, which includes sockaddr structures.
Including <sys/socketvar.h> should require <sys/socket.h>; add it in
the appropriate place.
PR: 211385
Submitted by: Sergey Kandaurov and iron at mail.ua
Reviewed by: gnn
Approved by: gnn (mentor)
MFC after: 1 day
Now zero value of arg1 used to specify "tablearg", use the old "tablearg"
value for "nat global". Introduce new macro IP_FW_NAT44_GLOBAL to replace
hardcoded magic number to specify "nat global". Also replace 65535 magic
number with corresponding macro. Fix typo in comments.
PR: 211256
Tested by: Victor Chernov
MFC after: 3 days
unordered user messages using DATA chunks as invalid ones.
While there, ensure that error causes are provided when
sending ABORT chunks in case of reassembly problems detected.
Thanks to Taylor Brandstetter for making me aware of this problem.
MFC after: 3 days
_prison_check_ip4 renamed to prison_check_ip4_locked
Move IPv6-specific jail functions to new file netinet6/in6_jail.c
_prison_check_ip6 renamed to prison_check_ip6_locked
Add appropriate prototypes to sys/sys/jail.h
Adjust kern_jail.c to call prison_check_ip4_locked and
prison_check_ip6_locked accordingly.
Add netinet/in_jail.c and netinet6/in6_jail.c to the list of files that
need to be built when INET and INET6, respectively, are configured in the
kernel configuration file.
Reviewed by: jtl
Approved by: sjg (mentor)
Sponsored by: Juniper Networks, Inc.
Differential Revision: https://reviews.freebsd.org/D6799
last SID/SSN pair wasn't filled in.
Thanks to Julian Cordes for providing a packetdrill script
triggering the issue and making me aware of the bug.
MFC after: 3 days
This keeps the segments/ACK/FIN delivery order.
Before this patch, it was observed: if A sent FIN immediately after
an ACK, B would deliver FIN first to the TCP stack, then the ACK.
This out-of-order delivery causes one unnecessary ACK sent from B.
Reviewed by: gallatin, hps
Obtained from: rrs, gallatin
Sponsored by: Netflix (rrs, gallatin), Microsoft (sephe)
Differential Revision: https://reviews.freebsd.org/D7415
- Re-write tcp_ctlinput6() to closely mimic the IPv4 tcp_ctlinput()
- Now that tcp_ctlinput6() updates t_maxseg, we can allow ip6_output()
to send TCP packets without looking at the tcp host cache for every
single transmit.
- Make the icmp6 code mimic the IPv4 code & avoid returning
PRC_HOSTDEAD because it is so expensive.
Without these changes in place, every TCP6 pmtu discovery or host
unreachable ICMP resulted in a call to in6_pcbnotify() which walks the
tcbinfo table with the write lock held. Because the tcbinfo table is
shared between IPv4 and IPv6, this causes huge scalabilty issues on
servers with lots of (~100K) TCP connections, to the point where even
a small percent of IPv6 traffic had a disproportionate impact on
overall throughput.
Reviewed by: bz, rrs, ae (all earlier versions), lstewart (in Netflix's tree)
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D7272
calling in_pcbnotifyall().
This avoids lock contention on tcbinfo due to in_pcbnotifyall()
holding the tcbinfo write lock while walking all connections.
Reviewed by: rrs, karels
MFC after: 2 weeks
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D7251
code in this file was written by Robert N. M. Waston.
Move cr_can* prototypes from sys/systm.h to sys/proc.h
Reported by: rwatson
Reviewed by: rwatson
Approved by: sjg (mentor)
Differential Revision: https://reviews.freebsd.org/D7345
- Move cr_canseeinpcb to sys/netinet/in_prot.c in order to separate the
INET and INET6-specific code from the rest of the prot code (It is only
used by the network stack, so it makes sense for it to live with the
other network stack code.)
- Move cr_canseeinpcb prototype from sys/systm.h to netinet/in_systm.h
- Rename cr_seeotheruids to cr_canseeotheruids and cr_seeothergids to
cr_canseeothergids, make them non-static, and add prototypes (so they
can be seen/called by in_prot.c functions.)
- Remove sw_csum variable from ip6_forward in ip6_forward.c, as it is an
unused variable.
Reviewed by: gnn, jtl
Approved by: sjg (mentor)
Sponsored by: Juniper Networks, Inc.
Differential Revision: https://reviews.freebsd.org/D2901
r301217 re-added per-connection L2 caching from a previous change,
but it omitted caching in the fast path. Add it.
Reviewed By: gallatin
Approved by: gnn (mentor)
Differential Revision: https://reviews.freebsd.org/D7239
The keep-state, limit and check-state now will have additional argument
flowname. This flowname will be assigned to dynamic rule by keep-state
or limit opcode. And then can be matched by check-state opcode or
O_PROBE_STATE internal opcode. To reduce possible breakage and to maximize
compatibility with old rulesets default flowname introduced.
It will be assigned to the rules when user has omitted state name in
keep-state and check-state opcodes. Also if name is ambiguous (can be
evaluated as rule opcode) it will be replaced to default.
Reviewed by: julian
Obtained from: Yandex LLC
MFC after: 1 month
Relnotes: yes
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D6674
as defined in RFC 6296. The module works together with ipfw(4) and
implemented as its external action module. When it is loaded, it registers
as eaction and can be used in rules. The usage pattern is similar to
ipfw_nat(4). All matched by rule traffic goes to the NPT module.
Reviewed by: hrs
Obtained from: Yandex LLC
MFC after: 1 month
Relnotes: yes
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D6420
debugging TCP connections. This commit provides a mechanism to free those
mbufs when the system is under memory pressure.
Because this will result in lost debugging information, the behavior is
controllable by a sysctl. The default setting is to free the mbufs.
Reviewed by: gnn
Approved by: re (gjb)
Differential Revision: https://reviews.freebsd.org/D6931
Input from: novice_techie.com
mp_maxid or CPU_FOREACH() as appropriate. This fixes a number of places in
the kernel that assumed CPU IDs are dense in [0, mp_ncpus) and would try,
for example, to run tasks on CPUs that did not exist or to allocate too
few buffers on systems with sparse CPU IDs in which there are holes in the
range and mp_maxid > mp_ncpus. Such circumstances generally occur on
systems with SMT, but on which SMT is disabled. This patch restores system
operation at least on POWER8 systems configured in this way.
There are a number of other places in the kernel with potential problems
in these situations, but where sparse CPU IDs are not currently known
to occur, mostly in the ARM machine-dependent code. These will be fixed
in a follow-up commit after the stable/11 branch.
PR: kern/210106
Reviewed by: jhb
Approved by: re (glebius)
for SCTP DATA and I-DATA chunks.
* For fragmented user messages, set the I-Bit only on the last
fragment.
* When using explicit EOR mode, set the I-Bit on the last
fragment, whenever SCTP_SACK_IMMEDIATELY was set in snd_flags
for any of the send() calls.
Approved by: re (hrs)
MFC after: 1 week
for messages which have been put on the send queue:
* Do not report any DATA or I-DATA chunk padding.
* Correctly deal with the I-DATA chunk header instead of the DATA
chunk header when the I-DATA extension is used.
Approved by: re (kib)
MFC after: 1 week
use. Update comments regarding the spare fields in struct inpcb.
Bump __FreeBSD_version for the changes to the size of the structures.
Reviewed by: gnn@
Approved by: re@ (gjb@)
Sponsored by: Chelsio Communications
this code in the userland stack, it could result in a loop. This happened on iOS.
However, I was not able to reproduce this when using the code in the kernel.
Thanks to Eugen-Andrei Gavriloaie for reporting the issue and proving detailed
information to find the root of the problem.
Approved by: re (gjb)
MFC after: 1 week
That way timers can finish cleanly and we do not gamble with a DELAY().
Reviewed by: gnn, jtl
Approved by: re (gjb)
Obtained from: projects/vnet
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D6923
Timewait code does a proper cleanup after itself.
Reviewed by: gnn
Approved by: re (gjb)
Obtained from: projects/vnet
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D6922
than removing the network interfaces first. This change is rather larger
and convoluted as the ordering requirements cannot be separated.
Move the pfil(9) framework to SI_SUB_PROTO_PFIL, move Firewalls and
related modules to their own SI_SUB_PROTO_FIREWALL.
Move initialization of "physical" interfaces to SI_SUB_DRIVERS,
move virtual (cloned) interfaces to SI_SUB_PSEUDO.
Move Multicast to SI_SUB_PROTO_MC.
Re-work parts of multicast initialisation and teardown, not taking the
huge amount of memory into account if used as a module yet.
For interface teardown we try to do as many of them as we can on
SI_SUB_INIT_IF, but for some this makes no sense, e.g., when tunnelling
over a higher layer protocol such as IP. In that case the interface
has to go along (or before) the higher layer protocol is shutdown.
Kernel hhooks need to go last on teardown as they may be used at various
higher layers and we cannot remove them before we cleaned up the higher
layers.
For interface teardown there are multiple paths:
(a) a cloned interface is destroyed (inside a VIMAGE or in the base system),
(b) any interface is moved from a virtual network stack to a different
network stack ("vmove"), or (c) a virtual network stack is being shut down.
All code paths go through if_detach_internal() where we, depending on the
vmove flag or the vnet state, make a decision on how much to shut down;
in case we are destroying a VNET the individual protocol layers will
cleanup their own parts thus we cannot do so again for each interface as
we end up with, e.g., double-frees, destroying locks twice or acquiring
already destroyed locks.
When calling into protocol cleanups we equally have to tell them
whether they need to detach upper layer protocols ("ulp") or not
(e.g., in6_ifdetach()).
Provide or enahnce helper functions to do proper cleanup at a protocol
rather than at an interface level.
Approved by: re (hrs)
Obtained from: projects/vnet
Reviewed by: gnn, jhb
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D6747
generally cleanup code might still acquire it thus try to be
consistent destroying locks late.
Obtained from: projects/vnet
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Add accessor functions to toggle the state per VNET.
The base system (vnet0) will always enable itself with the normal
registration. We will share the registered protocol handlers in all
VNETs minimising duplication and management.
Upon disabling netisr processing for a VNET drain the netisr queue from
packets for that VNET.
Update netisr consumers to (de)register on a per-VNET start/teardown using
VNET_SYS(UN)INIT functionality.
The change should be transparent for non-VIMAGE kernels.
Reviewed by: gnn (, hiren)
Obtained from: projects/vnet
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D6691
Replacing the bubble sort with insertion sort gives an 80% reduction
in runtime on average, with randomized keys, for small partitions.
If the keys are pre-sorted, insertion sort runs in linear time, and
even if the keys are reversed, insertion sort is faster than bubble
sort, although not by much.
Update comment describing "tcp_lro_sort()" while at it.
Differential Revision: https://reviews.freebsd.org/D6619
Sponsored by: Mellanox Technologies
Tested by: Netflix
Suggested by: Pieter de Goeje <pieter@degoeje.nl>
Reviewed by: ed, gallatin, gnn, transport
but removed due to other changes in the system. Restore the llentry pointer
to the "struct route", and use it to cache the L2 lookup (ARP or ND6) as
appropriate.
Submitted by: Mike Karels
Differential Revision: https://reviews.freebsd.org/D6262
specific order. VNET_SYSUNINITs however are doing exactly that.
Thus remove the VIMAGE conditional field from the domain(9) protosw
structure and replace it with VNET_SYSUNINITs.
This also allows us to change some order and to make the teardown functions
file local static.
Also convert divert(4) as it uses the same mechanism ip(4) and ip6(4) use
internally.
Slightly reshuffle the SI_SUB_* fields in kernel.h and add a new ones, e.g.,
for pfil consumers (firewalls), partially for this commit and for others
to come.
Reviewed by: gnn, tuexen (sctp), jhb (kernel.h)
Obtained from: projects/vnet
MFC after: 2 weeks
X-MFC: do not remove pr_destroy
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D6652
This is required to signal connetion setup on non-blocking sockets
via becoming writable. This still allows for implicit connection
setup.
MFC after: 1 week
If the connection was persistent and receiving-only, several (12)
sporadic device insufficient buffers would cause the connection be
dropped prematurely:
Upon ENOBUFS in tcp_output() for an ACK, retransmission timer is
started. No one will stop this retransmission timer for receiving-
only connection, so the retransmission timer promises to expire and
t_rxtshift is promised to be increased. And t_rxtshift will not be
reset to 0, since no RTT measurement will be done for receiving-only
connection. If this receiving-only connection lived long enough
(e.g. >350sec, given the RTO starts from 200ms), and it suffered 12
sporadic device insufficient buffers, i.e. t_rxtshift >= 12, this
receiving-only connection would be dropped prematurely by the
retransmission timer.
We now assert that for data segments, SYNs or FINs either rexmit or
persist timer was wired upon ENOBUFS. And don't set rexmit timer
for other cases, i.e. ENOBUFS upon ACKs.
Discussed with: lstewart, hiren, jtl, Mike Karels
MFC after: 3 weeks
Sponsored by: Microsoft OSTC
Differential Revision: https://reviews.freebsd.org/D5872
Centre for Advanced Internet Architectures
Implementing AQM in FreeBSD
* Overview <http://caia.swin.edu.au/freebsd/aqm/index.html>
* Articles, Papers and Presentations
<http://caia.swin.edu.au/freebsd/aqm/papers.html>
* Patches and Tools <http://caia.swin.edu.au/freebsd/aqm/downloads.html>
Overview
Recent years have seen a resurgence of interest in better managing
the depth of bottleneck queues in routers, switches and other places
that get congested. Solutions include transport protocol enhancements
at the end-hosts (such as delay-based or hybrid congestion control
schemes) and active queue management (AQM) schemes applied within
bottleneck queues.
The notion of AQM has been around since at least the late 1990s
(e.g. RFC 2309). In recent years the proliferation of oversized
buffers in all sorts of network devices (aka bufferbloat) has
stimulated keen community interest in four new AQM schemes -- CoDel,
FQ-CoDel, PIE and FQ-PIE.
The IETF AQM working group is looking to document these schemes,
and independent implementations are a corner-stone of the IETF's
process for confirming the clarity of publicly available protocol
descriptions. While significant development work on all three schemes
has occured in the Linux kernel, there is very little in FreeBSD.
Project Goals
This project began in late 2015, and aims to design and implement
functionally-correct versions of CoDel, FQ-CoDel, PIE and FQ_PIE
in FreeBSD (with code BSD-licensed as much as practical). We have
chosen to do this as extensions to FreeBSD's ipfw/dummynet firewall
and traffic shaper. Implementation of these AQM schemes in FreeBSD
will:
* Demonstrate whether the publicly available documentation is
sufficient to enable independent, functionally equivalent implementations
* Provide a broader suite of AQM options for sections the networking
community that rely on FreeBSD platforms
Program Members:
* Rasool Al Saadi (developer)
* Grenville Armitage (project lead)
Acknowledgements:
This project has been made possible in part by a gift from the
Comcast Innovation Fund.
Submitted by: Rasool Al-Saadi <ralsaadi@swin.edu.au>
X-No objection: core
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D6388
Not all mbufs passed up from device drivers are M_WRITABLE(). In
particular, the Chelsio T4/T5 driver uses a feature called "buffer packing"
to receive multiple frames in a single receive buffer. The mbufs for
these frames all share the same external storage so are treated as
read-only by the rest of the stack when multiple frames are in flight.
Previously tcp_respond() would blindly overwrite read-only mbufs when
INVARIANTS was disabled or panic with an assertion failure if INVARIANTS
was enabled. Note that the new case is a bit of a mix of the two other
cases in tcp_respond(). The TCP and IP headers must be copied explicitly
into the new mbuf instead of being inherited (similar to the m == NULL
case), but the addresses and ports must be swapped in the reply (similar
to the m != NULL case).
Reviewed by: glebius
"qsort()".
The kernel's "qsort()" routine can in worst case spend O(N*N) amount of
comparisons before the input array is sorted. It can also recurse a
significant amount of times using up the kernel's interrupt thread
stack.
The custom sorting routine takes advantage of that the sorting key is
only 64 bits. Based on set and cleared bits in the sorting key it
partitions the array until it is sorted. This process has a recursion
limit of 64 times, due to the number of set and cleared bits which can
occur. Compiled with -O2 the sorting routine was measured to use
64-bytes of stack. Multiplying this by 64 gives a maximum stack
consumption of 4096 bytes for AMD64. The same applies to the execution
time, that the array to be sorted will not be traversed more than 64
times.
When serving roughly 80Gb/s with 80K TCP connections, the old method
consisting of "qsort()" and "tcp_lro_mbuf_compare_header()" used 1.4%
CPU, while the new "tcp_lro_sort()" used 1.1% for LRO related sorting
as measured by Intel Vtune. The testing was done using a sysctl to
toggle between "qsort()" and "tcp_lro_sort()".
Differential Revision: https://reviews.freebsd.org/D6472
Sponsored by: Mellanox Technologies
Tested by: Netflix
Reviewed by: gallatin, rrs, sephe, transport
* include the SCTP common header, if possible
* include the first 8 bytes of the INIT chunk, if possible
This provides the necesary information for the receiver of the ICMP
packet to process it.
MFC after: 1 week
control to a three way setting.
0 - Totally disable ECN. (no change)
1 - Enable ECN if incoming connections request it. Outgoing
connections will request ECN. (no change from present != 0 setting)
2 - Enable ECN if incoming connections request it. Outgoing
conections will not request ECN.
Change the default value of net.inet.tcp.ecn.enable from 0 to 2.
Linux version 2.4.20 and newer, Solaris, and Mac OS X 10.5 and newer have
similar capabilities. The actual values above match Linux, and the default
matches the current Linux default.
Reviewed by: eadler
MFC after: 1 month
MFH: yes
Sponsored by: https://reviews.freebsd.org/D6386
structures in the add of a new tcp-stack that came in late to me
via email after the last commit. It also makes it so that a new
stack may optionally get a callback during a retransmit
timeout. This allows the new stack to clear specific state (think
sack scoreboards or other such structures).
Sponsored by: Netflix Inc.
Differential Revision: http://reviews.freebsd.org/D6303
objects with the same name in different sets.
Add optional manage_sets() callback to objects rewriting framework.
It is intended to implement handler for moving and swapping named
object's sets. Add ipfw_obj_manage_sets() function that implements
generic sets handler. Use new callback to implement sets support for
lookup tables.
External actions objects are global and they don't support sets.
Modify eaction_findbyname() to reflect this.
ipfw(8) now may fail to move rules or sets, because some named objects
in target set may have conflicting names.
Note that ipfw_obj_ntlv type was changed, but since lookup tables
actually didn't support sets, this change is harmless.
Obtained from: Yandex LLC
Sponsored by: Yandex LLC
There was the requirement that two structures are in sync,
which is not valid anymore. Therefore don't rely on this
in the code anymore.
Thanks to Radek Malcic for reporting the issue. He found this
when using the userland stack.
MFC after: 1 week
Ease more work concerning active list, e.g. hash table etc.
Reviewed by: gallatin, rrs (earlier version)
Sponsored by: Microsoft OSTC
Differential Revision: https://reviews.freebsd.org/D6137
chunk, enable UDP encapsulation for all those addresses.
This helps clients using a userland stack to support multihoming if
they are not behind a NAT.
MFC after: 1 week
This is currently only a code change without any functional
change. But this allows to set the remote encapsulation port
in a more detailed way, which will be provided in a follow-up
commit.
MFC after: 1 week
So the underlying drivers can use it to select the sending queue
properly for SYN|ACK instead of rolling their own hash.
Sponsored by: Microsoft OSTC
Differential Revision: https://reviews.freebsd.org/D6120
interested in having tunneled UDP and finding out about the
ICMP (tested by Michael Tuexen with SCTP.. soon to be using
this feature).
Differential Revision: http://reviews.freebsd.org/D5875
async_drain functionality. This as been tested in NF as well as
by Verisign. Still to do in here is to remove all the old flags. They
are currently left being maintained but probably are no longer needed.
Sponsored by: Netflix Inc.
Differential Revision: http://reviews.freebsd.org/D5924
In principle n is only used to carry a copy of ipi_count, which is
unsigned, in the non-VIMAGE case, however ipi_count can be used
directly so it is not needed at all. Removing it makes things look
cleaner.
The disgusting macro INP_WLOCK_RECHECK may early-return. In
tcp_default_ctloutput() the TCP_CCALGOOPT case allocates memory before invoking
this macro, which may leak memory.
Add a _CLEANUP variant that takes a code argument to perform variable cleanup
in the early return path. Use it to free the 'pbuf' allocated in
tcp_default_ctloutput().
I am not especially happy with this macro, but I reckon it's not any worse than
INP_WLOCK_RECHECK already was.
Reported by: Coverity
CID: 1350286
Sponsored by: EMC / Isilon Storage Division
tp->snd_wnd. This can happen, for example, when the remote side responds to
a window probe by ACKing the one byte it contains.
Differential Revision: https://reviews.freebsd.org/D5625
Reviewed by: hiren
Obtained from: Juniper Networks (earlier version)
MFC after: 2 weeks
Sponsored by: Juniper Networks
It allows implementing loadable kernel modules with new actions and
without needing to modify kernel headers and ipfw(8). The module
registers its action handler and keyword string, that will be used
as action name. Using generic syntax user can add rules with this
action. Also ipfw(8) can be easily modified to extend basic syntax
for external actions, that become a part base system.
Sample modules will coming soon.
Obtained from: Yandex LLC
Sponsored by: Yandex LLC
containing an INIT chunk. These need to be handled in case the peer
does not support SCTP and returns an ICMP messages indicating destination
unreachable, protocol unreachable.
MFC after: 1 week
the outer IP header, the ICMP header, the inner IP header and the
first n bytes are stored in contgous memory. The ctlinput functions
currently rely on this for n = 8. This fixes a bug in case the inner IP
header had options.
While there, remove the options from the outer header and provide a
way to increase n to allow improved ICMP handling for SCTP. This will
be added in another commit.
MFC after: 1 week
It does not cause any real issues because the variable is overwritten
only when the packet is forwarded (and the variable is not used anymore).
Obtained from: pfSense
MFC after: 2 weeks
Sponsored by: Rubicon Communications (Netgate)
is required to check the verification tag. However, this
requires the verification tag to be not 0. Enforce this.
For packets with a verification tag of 0, we need to
check it it contains an INIT chunk and use the initiate
tag for the validation. This will be a separate commit,
since it touches also other code.
MFC after: 1 week
It looks like as with the safety belt of DELAY() fastened (*) we can
completely tear down and free all memory for TCP (after r281599).
(*) in theory a few ticks should be good enough to make sure the timers
are all really gone. Could we use a better matric here and check a
tcbcb count as an optimization?
PR: 164763
Reviewed by: gnn, emaste
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D5734
The tcp_inpcb (pcbinfo) zone should be safe to destroy.
PR: 164763
Reviewed by: gnn
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D5732
We attach the "counter" to the tcpcbs. Thus don't free the
TCP Fastopen zone before the tcpcbs are gone, as otherwise
the zone won't be empty.
With that it should be safe to destroy the "tfo" zone without
leaking the memory.
PR: 164763
Reviewed by: gnn
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D5731
While there is no dependency interaction, stopping the timer before
freeing the rest of the resources seems more natural and avoids it
being scheduled an extra time when it is no longer needed.
Reviewed by: gnn, emaste
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D5733
No need to keep type stability on raw sockets zone.
We've also been running with a KASSERT since r222488 to make sure the
ipi_count is 0 on destroy.
PR: 164763
Reviewed by: gnn
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D5735
adds the new I-Data (Interleaved Data) message. This allows a user
to be able to have complete freedom from Head Of Line blocking that
was previously there due to the in-ability to send multiple large
messages without the TSN's being in sequence. The code as been
tested with Michaels various packet drill scripts as well as
inter-networking between the IETF's location in Argentina and Germany.
This is kinda critical to the performance when the CPU is slow and
network bandwidth is high, e.g. in the hypervisor.
Reviewed by: rrs, gallatin, Dexuan Cui <decui microsoft com>
Sponsored by: Microsoft OSTC
Differential Revision: https://reviews.freebsd.org/D5765
And factor out tcp_lro_rx_done, which deduplicates the same logic with
netinet/tcp_lro.c
Reviewed by: gallatin (1st version), hps, zbb, np, Dexuan Cui <decui microsoft com>
Sponsored by: Microsoft OSTC
Differential Revision: https://reviews.freebsd.org/D5725
So that callers could react accordingly.
Reviewed by: gallatin (no objection)
MFC after: 1 week
Sponsored by: Microsoft OSTC
Differential Revision: https://reviews.freebsd.org/D5695
- properly V_irtualise variable access unbreaking VIMAGE kernels.
- remove the volatile from the function return type to make architecture
using gcc happy [-Wreturn-type]
"type qualifiers ignored on function return type"
I am not entirely happy with this solution putting the u_int there
but it will do for now.
route caching for TCP, with some improvements. In particular, invalidate
the route cache if a new route is added, which might be a better match.
The cache is automatically invalidated if the old route is deleted.
Submitted by: Mike Karels
Reviewed by: gnn
Differential Revision: https://reviews.freebsd.org/D4306
Furthermore, there is no reason this needs to be a 64-bit integer
for the forseeable future.
Also, there is an inconsistency between to_flags and the mask in
tcp_addoptions(). Before r195654, to_flags was a u_long and the mask in
tcp_addoptions() was a u_int. r195654 changed to_flags to be a u_int64_t
but left the mask in tcp_addoptions() as a u_int, meaning that these
variables will only be the same width on platforms with 64-bit integers.
Convert both to_flags and the mask in tcp_addoptions() to be explicitly
32-bit variables. This may save a few cycles on 32-bit platforms, and
avoids unnecessarily mixing types.
Differential Revision: https://reviews.freebsd.org/D5584
Reviewed by: hiren
MFC after: 2 weeks
Sponsored by: Juniper Networks
struct tcpstat, because the structure can be zeroed out by netstat(1) -z,
and of course running connection counts shouldn't be touched.
Place running connection counts into separate array, and provide
separate read-only sysctl oid for it.
stack is not compliant with RFC 7323, which requires that TCP stacks send
a timestamp option on all packets (except, optionally, RSTs) after the
session is established.
This patch adds that support. It also adds a TCP signature option to the
packet, if appropriate.
PR: 206047
Differential Revision: https://reviews.freebsd.org/D4808
Reviewed by: hiren
MFC after: 2 weeks
Sponsored by: Juniper Networks
- Reorder variables by size
- Move initializer closer to where it is used
- Remove unneeded variable
Differential Revision: https://reviews.freebsd.org/D4808
Reviewed by: hiren
MFC after: 2 weeks
Sponsored by: Juniper Networks
for output and drop; connect didn't always fire a user probe
some probes were missing in fastpath
Submitted by: Hannes Mehnert
Sponsored by: REMS, EPSRC
Differential Revision: https://reviews.freebsd.org/D5525
included in loader.conf. It also fixes it so that no matter if some one incorrectly
specifies a load order, the lists and such will be initialized on demand at that
time so no one can make that mistake.
Reviewed by: hiren
Differential Revision: D5189
ACK aggregation limit is append count based, while the TCP data segment
aggregation limit is length based. Unless the network driver sets these
two limits, it's an NO-OP.
Reviewed by: adrian, gallatin (previous version), hselasky (previous version)
Approved by: adrian (mentor)
MFC after: 1 week
Sponsored by: Microsoft OSTC
Differential Revision: https://reviews.freebsd.org/D5185
Fix a panic that occurs when a vnet interface is unavailable at the time the
vnet jail referencing said interface is stopped.
Sponsored by: FIS Global, Inc.
the sign bit doesn't cause an overflow. The overflow manifests itself
as a sorting index wrap around in the middle of the sorted array,
which is not a problem for the LRO code, but might be a problem for
the logic inside qsort().
Reviewed by: gnn @
Sponsored by: Mellanox Technologies
Differential Revision: https://reviews.freebsd.org/D5239
back and harmize the use cases among RIB, IPFW, PF yet but it's also not
the scope of this work. Prevents instant panics on teardown and frees
the FIB bits again.
Sponsored by: The FreeBSD Foundation
new addresses during restart. If this is not done, restart doesn't
work when the local socket is IPv4 only and the peer uses
IPv4 and IPv6 addresses.
MFC after: 3 days.
o Return back the buf[TCP_CA_NAME_MAX] for TCP_CONGESTION,
for TCP_CCALGOOPT use dynamically allocated *pbuf.
o For SOPT_SET TCP_CONGESTION do NULL terminating of string
taking from userland.
o For SOPT_SET TCP_CONGESTION do the search for the algorithm
keeping the inpcb lock.
o For SOPT_GET TCP_CONGESTION first strlcpy() the name
holding the inpcb lock into temporary buffer, then copyout.
Together with: lstewart
60 seconds, respectively. Turn them into sysctls that can be tuned live. The
default values of 5 seconds and 60 seconds have been retained.
Submitted by: Jason Wolfe (j at nitrology dot com)
Reviewed by: gnn, rrs, hiren, bz
MFC after: 1 week
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D5024
There are number of radix consumers in kernel land (pf,ipfw,nfs,route)
with different requirements. In fact, first 3 don't have _any_ requirements
and first 2 does not use radix locking. On the other hand, routing
structure do have these requirements (rnh_gen, multipath, custom
to-be-added control plane functions, different locking).
Additionally, radix should not known anything about its consumers internals.
So, radix code now uses tiny 'struct radix_head' structure along with
internal 'struct radix_mask_head' instead of 'struct radix_node_head'.
Existing consumers still uses the same 'struct radix_node_head' with
slight modifications: they need to pass pointer to (embedded)
'struct radix_head' to all radix callbacks.
Routing code now uses new 'struct rib_head' with different locking macro:
RADIX_NODE_HEAD prefix was renamed to RIB_ (which stands for routing
information base).
New net/route_var.h header was added to hold routing subsystem internal
data. 'struct rib_head' was placed there. 'struct rtentry' will also
be moved there soon.
Saw all the printfs already.
Note: not sure the atomics are needed but without them, the condition
would never trigger, and we'd still see panics (which could have been
due to the insert race). Will work my way backwards in case this stays
stable.
Sponsored by: The FreeBSD Foundation
