To be honest, I would classify blocking lo a bug.
But it is a good to know that blocking lo causes this behaviour on the
steam client.
I wonder if removing 127.0.0.1 and just leaving ::1 on lo would make it
switcht to using ipv6.
From a security standpoint blocking lo isn't a bad thing but quite advanced. Maybe related but I'm more confused with what this process is doing? Steam isn't even opened yet it's spinning, constantly reconnecting to the X server??
$ strace -p 11931 -c -T & sleep 10 ; kill $!
Process 11931 attached
[ Process PID=11931 runs in 32 bit mode. ]
Process 11931 detached
System call usage summary for 32 bit mode:
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
63.40 0.033463 57 587 poll
21.29 0.011236 1 8037 clock_gettime
5.62 0.002966 13 225 27 futex
1.77 0.000935 5 196 nanosleep
1.75 0.000921 1 1791 gettid
1.60 0.000845 1 608 time
1.26 0.000663 1 588 588 recvmsg
1.04 0.000549 4 149 write
0.62 0.000325 2 196 196 semop
0.51 0.000271 1 196 read
0.42 0.000224 1 196 waitpid
0.28 0.000147 1 103 select
0.22 0.000118 118 1 restart_syscall
0.18 0.000095 1 98 kill
0.04 0.000020 1 26 tgkill
------ ----------- ----------- --------- --------- ----------------
100.00 0.052778 12997 811 total
$
Is this a joke??
$ ps -u -p `pidof steam`
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
steam 11931 1.4 0.9 350236 152204 pts/101 Sl+ Jul17 50:44 /home/steam/.local/share/Steam/ubuntu12_32/steam
steam 11934 0.0 0.2 135204 37008 pts/101 S+ Jul17 0:00 /home/steam/.local/share/Steam/ubuntu12_32/steam
At over 50 CPU minutes in a little over a day, it literally is the 3rd biggest CPU pig on that box behind X itself and Firefox. Valve??
Nothing extracted yet.
With (mis?)configured firewall, steam ceases to work properly (presents as UI lag and games not starting up).
Fairly popular "simple stateful firewall" will break steam:
Unless loopback device is allowed:
steam output
Not sure this classifies as a bug, but it's fairly hard to debug (processes stuck waiting on file descriptors) and prevents steam from functioning properly. I suppose steam could do IPC over something other than loopback.