separate the decision logic, of whether we can do TSO, and the
calculation of the burst length into two distinct parts.
Change the way the TSO burst length calculation is done. While
TSO could do bursts of 65535 bytes that can't be represented in
ip_len together with the IP and TCP header. Account for that and
use IP_MAXPACKET instead of TCP_MAXWIN as base constant (both
have the same value of 64K). When more data is available prevent
less than MSS sized segments from being sent during the current
TSO burst.
Add two more KASSERTs to ensure the integrity of the packets.
Tested by: Ben Wilber <ben-at-desync com>
MFC after: 10 days
to give way for the pluggable congestion control framework. It is
the task of the congestion control algorithm to set the congestion
window and amount of inflight data without external interference.
In 'struct tcpcb' the variables previously used by the inflight
limiter are renamed to spares to keep the ABI intact and to have
some more space for future extensions.
In 'struct tcp_info' the variable 'tcpi_snd_bwnd' is not removed to
preserve the ABI. It is always set to 0.
In siftr.c in 'struct pkt_node' the variable 'snd_bwnd' is not removed
to preserve the ABI. It is always set to 0.
These unused variable in the various structures may be reused in the
future or garbage collected before the next release or at some other
point when an ABI change happens anyway for other reasons.
No MFC is planned. The inflight bandwidth limiter stays disabled by
default in the other branches but remains available.
a small difference in the last paragraph though) as suggested by jhb.
Clarify that the 'reviewed by' in r212653 by lstewart was for the
functional change, not the comments in the committed version.
artificial power-of-2 rounded number to their real values specified
in RFC879 and RFC2460.
From the history and existing comments it appears that the rounded
numbers were intended to be advantageous for the kernel and mbuf
system. However this hasn't been the case at for at least a long
time. The mbuf clusters used in tcp_output() have enough space
to hold the larger real value for the default MSS for both IPv4 and
IPv6. Note that the default MSS is only used when path MTU discovery
is disabled.
Update and expand related comments.
Reviewed by: lsteward (including some word-smithing)
MFC after: 2 weeks
using ipproto_{un,}register() and the newly created ip6proto_{un,}register()
so that it can again receive IPPROTO_CARP packets allowing its state machine
to work.
Reviewed by: bz
Approved by: ken (mentor)
In protosw we define pr_protocol as short, while on the wire
it is an uint8_t. That way we can have "internal" protocols
like DIVERT, SEND or gaps for modules (PROTO_SPACER).
Switch ipproto_{un,}register to accept a short protocol number(*)
and do an upfront check for valid boundries. With this we
also consistently report EPROTONOSUPPORT for out of bounds
protocols, as we did for proto == 0. This allows a caller
to not error for this case, which is especially important
if we want to automatically call these from domain handling.
(*) the functions have been without any in-tree consumer
since the initial introducation, so this is considered save.
Implement ip6proto_{un,}register() similarly to their legacy IP
counter parts to allow modules to hook up dynamically.
Reviewed by: philip, will
MFC after: 1 week
pseudo-interface. This leads to a panic due to uninitialized
if_broadcastaddr address. Initialize it and implement ip_output()
method to prevent mbuf leak later.
ipfw pseudo-interface should never send anything therefore call
panic(9) in if_start() method.
PR: kern/149807
Submitted by: Dmitrij Tejblum
MFC after: 2 weeks
Fix the switching on/off of PF and NR-SACKs using sysctl.
Add minor improvement in handling malloc failures.
Improve the address checks when sending.
MFC after: 4 weeks
Add kernel side support for Secure Neighbor Discovery (SeND), RFC 3971.
The implementation consists of a kernel module that gets packets from
the nd6 code, sends them to user space on a dedicated socket and reinjects
them back for further processing.
Hooks are used from nd6 code paths to divert relevant packets to the
send implementation for processing in user space. The hooks are only
triggered if the send module is loaded. In case no user space
application is connected to the send socket, processing continues
normaly as if the module would not be loaded. Unloading the module
is not possible at this time due to missing nd6 locking.
The native SeND socket is similar to a raw IPv6 socket but with its own,
internal pseudo-protocol.
Approved by: bz (mentor)
it must reset its congestion window back to the initial window.
RFC3390 has increased the initial window from 1 segment to up to
4 segments.
The initial window increase of RFC3390 wasn't reflected into the
restart window which remained at its original defaults of 4 segments
for local and 1 segment for all other connections. Both values are
controllable through sysctl net.inet.tcp.local_slowstart_flightsize
and net.inet.tcp.slowstart_flightsize.
The increase helps TCP's slow start algorithm to open up the congestion
window much faster.
Reviewed by: lstewart
MFC after: 1 week
sysctl's and remove any side effects.
Both sysctl's share the same backend infrastructure and due to the
way it was implemented enabling net.inet.tcp.log_in_vain would also
cause log_debug output to be generated. This was surprising and
eventually annoying to the user.
The log output backend is kept the same but a little shim is inserted
to properly separate log_in_vain and log_debug and to remove any side
effects.
PR: kern/137317
MFC after: 1 week
number of syncache entries into account for the surplus we add to account
for a possible increase of records in the re-entry window.
Discussed with: jhb, silby
MFC after: 1 week
memory size estimate to userland for pcb list sysctls. The previous
behavior of a "slop" of n/8 does not work well for small values of n
(e.g. no slop at all if you have less than 8 open UDP connections).
Reviewed by: bz
MFC after: 1 week
path MTU discovery and the tcp_minmss limiter for very small MTU's.
When the MTU suggested by the gateway via ICMP, or if there isn't
any the next smaller step from ip_next_mtu(), is lower than the
floor enforced by net.inet.tcp.minmss (default 216) the value is
ignored and the default MSS (512) is used instead. However the
DF flag in the IP header is still set in tcp_output() preventing
fragmentation by the gateway.
Fix this by using tcp_minmss as the MSS and clear the DF flag if
the suggested MTU is too low. This turns off path MTU dissovery
for the remainder of the session and allows fragmentation to be
done by the gateway.
Only MTU's smaller than 256 are affected. The smallest official
MTU specified is for AX.25 packet radio at 256 octets.
PR: kern/146628
Tested by: Matthew Luckie <mjl-at-luckie org nz>
MFC after: 1 week
report when a new socket couldn't be created because one of
in_pcbinshash(), in6_pcbconnect() or in_pcbconnect() failed.
Logging is conditional on net.inet.tcp.log_debug being enabled.
MFC after: 1 week
and we loop back to 'again'. If the remainder is less or equal
to one full segment, the TSO flag was not cleared even though
it isn't necessary anymore. Enabling the TSO flag on a segment
that doesn't require any offloaded segmentation by the NIC may
cause confusion in the driver or hardware.
Reset the internal tso flag in tcp_output() on every iteration
of sendalot.
PR: kern/132832
Submitted by: Renaud Lienhart <renaud-at-vmware com>
MFC after: 1 week
a kernel printf to a log output with the priority of LOG_NOTICE.
This way the messages still show up in /var/log/messages but no
longer spam the console every other second on busy servers that
are port scanned:
"Limiting open port RST response from 114 to 100 packets/sec"
PR: kern/147352
Submitted by: Eugene Grosbein <eugen-at-eg sd rdtc ru>
MFC after: 1 week
It was experimental and interferes with the normal congestion control
algorithms by instating a separate, possibly lower, ceiling for the
amount of data that is in flight to the remote host. With high speed
internet connections the inflight limit frequently has been estimated
too low due to the noisy nature of the RTT measurements.
This code gives way for the upcoming pluggable congestion control
framework. It is the task of the congestion control algorithm to
set the congestion window and amount of inflight data without external
interference.
Reviewed by: lstewart
MFC after: 1 week
Removal after: 1 month
bridge(4), lagg(4) etc. and make use of function pointers and
pf_proto_register() to hook carp into the network stack.
Currently, because of the uncertainty about whether the unload path is free
of race condition panics, unloads are disallowed by default. Compiling with
CARPMOD_CAN_UNLOAD in CFLAGS removes this anti foot shooting measure.
This commit requires IP6PROTOSPACER, introduced in r211115.
Reviewed by: bz, simon
Approved by: ken (mentor)
MFC after: 2 weeks
interface goes to issue LINK_UP, then LINK_DOWN, then LINK_UP at
cold boot. This behavior is not observed when carp(4) interface
is created slightly later, when the underlying interface is fully
up.
Before this change what happen at boot is roughly:
- ifconfig creates em0 interface;
- ifconfig clones a carp device using em0;
(em0's link state is DOWN at this point)
- carp state: INIT -> BACKUP [*]
- carp state: BACKUP -> MASTER
- [Some negotiate between em0 and switch]
- em0 kicks up link state change event
(em0's link state is now up DOWN at this point)
- do_link_state_change() -> carp_carpdev_state()
- carp state: MASTER -> INIT (via carp_set_state(sc, INIT)) [+]
- carp state: INIT -> BACKUP
- carp state: BACKUP -> MASTER
At the [*] stage, em0 did not received any broadcast message from other
node, and assume our node is the master, thus carp(4) sets the link
state to "UP" after becoming a master. At [+], the master status
is forcely set to "INIT", then an election is casted, after which our
node would actually become a master.
We believe that at the [*] stage, the master status should remain as
"INIT" since the underlying parent interface's link state is not up.
Obtained from: iXsystems, Inc.
Reported by: jpaetzel
MFC after: 2 months
