to figure out what network connection a particular tls
conversation refers to, we add the path of the underlying
we send the encrypted tls traffic over in the status file,
example:
term% grep -n '^Chan:' '#a'/tls/*/status
#a/tls/0/status:7: Chan: /net/tcp/6/data
#a/tls/1/status:7: Chan: /net/tcp/0/data
/n/bugs/open/multicasts_and_udp_buffers
http://bugs.9front.org/open/multicasts_and_udp_buffers/readmemichal@Lnet.pl
I have ported my small MPEG-TS analisis tool to Plan9.
To allow this application working I had to fix a bug in the kernel IPv4 code and increase UDP input buffer.
Bug is related to listening for IPv4 multicast traffic. There is no problem if you listen for only one group or multiple groups with different UDP ports. This works:
Write to UDP ctl:
anounce PORT
addmulti INTERFACE_ADDR MULTICAST_ADDR
headers
and you can read packets from data file.
You need to set headers option because otherwise every UDP packet for MULTICAST_ADDR!PORT is treat as separate connection. This is a bug and should be fixed too, but I didn't tried it.
There is a problem when you need to receive packets for multiple multicast groups. Usually the same destination port is used by multiple streams and above sequence of commands fails for second group because the port is the same.
Simple and probably non-intrusive fix is adding "|| ipismulticast(addr)" to if statement at /sys/src/9/ip/devip.c:861 line:
if(ipforme(c->p->f, addr) || ipismulticast(addr))
This fixes the problem and now you can use the following sequence to listen for multiple multicast groups even if they all have the same destination port:
announce MULTICAST_ADDR!PORT
addmulti INTERFACE_ADDR MULTICAST_ADDR
headers
After that my application started working but signals packet drops at >2 Mb/s input rate. The same is reported by kernel netlog. Increase capacity of UDP connection input queue fixes this problem /sys/src/9/ip/udp.c:153
c->rq = qopen(512*1024, Qmsg, 0, 0);
--
Michał Derkacz
access to the axi segment hangs the machine when the fpga
is not programmed yet. to prevent access, we introduce a
new SG_FAULT flag, that when set on the Segment.type or
Physseg.attr, causes the fault handler to immidiately
return with an error (as if the segment would not be mapped).
during programming, we temporarily set the SG_FAULT flag
on the axi physseg, flush all processes tlb's that have
the segment mapped and when programming is done, we clear
the flag again.
tsleep() used to cancel the timer with:
if(up->tt != nil)
timerdel(up);
which still can result in twakeup() to fire after tsleep()
returns (because we set Timer.tt to nil *before* we call the tfn).
in most cases, this is not an issue as the Rendez*
usually is just &up->sleep, but when it is dynamically allocated
or on the stack like in tsemacquire(), twakeup() will call
wakeup() on a potentially garbage Rendez structure!
to fix the race, we execute the wakup() with the Timer lock
held, and set p->trend to nil only after we called wakeup().
that way, the timerdel(); which unconditionally locks the Timer;
can act as a proper barrier and use up->trend == nil as the
condition if the timer has already fired.
for queue like non-seekable files, it is impossible to implement an
exportfs because one has to run the kernels devtab read() and write()
in separate processes, and that makes it impossible to maintain 9p message
order as the scheduler can come in and randomly schedule one process before
another.
so as soon as we have a transition from 9p -> syscalls, we'r screwed.
i currently see just two possibilities:
- introduce special file type like QTSEQ with strictly ordered i/o semantics
- fix all fileservers and exportfs to only do one outstanding i/o to QTSEQ files
which means maintaining a queue per fid
this doesnt propagate. so exporting slow 9p mount again will be limited
again by latency of the inner mount.
other option:
- return offset in Rread, so client can bring responses back into order. this
requires changing all fileservers and drivers to maintain such an per fid offset
and change the protocol to include it in the response, and also pass it to userspace
(new syscalls or pass it in TOS)
this only works for read pipelining, write is still screwed.
both options suck.
--
cinap
this code was if(0) for a long time due to wrong parentesis,
fixed parentesis cause print spam on some machines making them
unusage (kenji okomoto). removing the check alltogether.
theres a bootstrap problem:
when /bin/init is run, it processes /lib/namespace where we might want to
mount or bind resources to /n or /mnt. but mntgen was run later in
cpurc/termrc so these mounts would be ignored.
we already have mntgen in bootfs, so we can provide these mountpoints early.
i keep the termrc/cpurc mntgens where they are, but ignore the error
prints. this way old kernels will continue to work.
apparently, this causes some quadcore ramnode vm to hang on boot,
even tho all cores successfully started up and are operational.
i suspect some side effect from timersinit()... this would also
mean *notsc= would break it (syncclock() would continue)...
its unclear.
i'm reverting this for now until the problem is better understood.
when testing in qemu, launching each ap became slower and slower
because all the ap's where spinning in syncclock() waiting for
cpu0 to update its mach0->tscticks, which happens only much later
after all cpu's have been started up.
now we wait for each cpu to do its timer callibration and
manually update our tscticks while we wait and each cpu will
not spin but halt while waiting for active.thunderbirdsarego.
this reduces the system load and noise for timer callibration
and makes the mp startup linear with regard to the number of
cores.
introduce cpushutdown() function that does the common
operation of initiating shutdown, returning once all
cpu's got the message and are about to shutdown. this
avoids duplicated code which isnt really machine specific.
automatic reboot on panic only when *debug= is not set
and the machine is a cpu server or has no display,
otherwise just hang.
to solve the usb device enumeration race on boot, usbd creates /env/usbbusy
on startup and once all devices have been enumerated and readers have consumed
all the events, we remove the file so nusbrc/bootrc can continue. this makes
sure all the usb devices that where plugged in on boot are made available.
when opening a /env file ORCLOSE, and the process exits, envgrp() would
return nil can crash in envremove() because procexit will have set up->egrp
to nil before calling closefgrp().
the solution is to capture the environment on open, keeping a reference in
Chan.aux, so it doesnt matter on what process the close happens and a
env chan will always refer to its original environment group.
instead of checking addr+len >= addr, check len >= -addr so
that addr == 0 is never valid for len > 0 even if we decide
to have memory at the zero page so theres never any chance
user can pass in "nil" pointers.
put up some signs where we fall thru the switch cases in
fixfault()
sha256 is only defined for TLS1.2, however, technically, theres
no reason not to use it in TLS1.0/TLS1.1. the choice is up to
tlshand and pushtls, not the kernel.
introduce wificfg() function to convert ether->opt[] strings
to wifictl messages, which needs quoting for the value. so
etherX=type=iwl essid='something with spaces' works.
- fix missing runlock(ifc) when ifcid != a->ifcid in rxmitsols() (thanks erik quanstro)
- don't leak packets when transfering blocks from arp entry hold list to droplist
- free rest of droplist when bwrite() errors in arpenter(), remove useless checks (ifc != nil)
- free arp entry hold list from cleanarpent()
- consistent use of nil for pointers
