Re: kqueue send over unix socket?
On 12.03.19 22:52, Aki Tuomi wrote: > Hi! > > I am trying exactly that. As others have already stated kqueue file descriptors can leave the process that created them (neither through file descriptor passing nor through inheritance). Can you tell us why you want to send the kqueue file descriptor to an other process? What do you want to accomplish? ___ freebsd-current@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
Re: kqueue send over unix socket?
Hi!
I am trying exactly that.
dtrace output gives following
# dtrace -s sendmsg.d -p 61387
dtrace: script 'sendmsg.d' matched 30667 probes
CPU IDFUNCTION:NAME
0 16637 uipc_send:return
kernel`sosend_generic+0x556
kernel`kern_sendit+0x296
kernel`sendit+0x19e
kernel`sys_sendmsg+0x61
kernel`amd64_syscall+0xa38
kernel`0x80f5891d
0 35794sosend_generic:return
kernel`kern_sendit+0x296
kernel`sendit+0x19e
kernel`sys_sendmsg+0x61
kernel`amd64_syscall+0xa38
kernel`0x80f5891d
0 32432 kern_sendit:return
kernel`sendit+0x19e
kernel`sys_sendmsg+0x61
kernel`amd64_syscall+0xa38
kernel`0x80f5891d
0 55533 free:return
kernel`sendit+0x1b0
kernel`sys_sendmsg+0x61
kernel`amd64_syscall+0xa38
kernel`0x80f5891d
0 16604sendit:return
kernel`sys_sendmsg+0x61
kernel`amd64_syscall+0xa38
kernel`0x80f5891d
0 30776 sys_sendmsg:return
kernel`amd64_syscall+0xa38
kernel`0x80f5891d
> On 12 March 2019 23:37 Alan Somers wrote:
>
>
> Is he trying to send the kqueue file descriptor itself using sendmsg
> with SCM_RIGHTS? It sounds like kqueues cannot be sent over unix
> sockets; not every file type necessarily can. But if you want to know
> the nitty-gritty details, just run this:
> dtrace -i 'fbt:::return /arg1 == 45/ {stack();}' -c "my_program
> my_options" and that will usually tell you the exact function that set
> the error.
>
> If the output is too large, then you can filter it by writing a D
> program like this:
>
> #sendmsg.d
> fbt:kernel:sys_sendmsg:entry
> {
> this->trigger = 1;
> }
> fbt:::return
> / this->trigger == 1 && arg1 == 45 /
> {
> stack();
> }
> fbt:kernel:sys_sendmsg:return
> {
> this->trigger = 0;
> }
>
> dtrace -s sendmsg.d -c "my_program my_options"
>
> Hope that helps.
> -Alan
>
> On Tue, Mar 12, 2019 at 3:22 PM Larry Rosenman wrote:
> >
> > I'm working with Aki Tuomi of Dovecot and he asks:
> >
> > I tried to ask if you could ask from some Kernel hacker why I cannot
> > send kqueue() fd over unix socket, I get "Operation not supported".
> >
> > Can anyone help me?
> >
> >
> >
> > --
> > Larry Rosenman http://www.lerctr.org/~ler
> > Phone: +1 214-642-9640 E-Mail: l...@lerctr.org
> > US Mail: 5708 Sabbia Dr, Round Rock, TX 78665-2106
> > ___
> > freebsd-current@freebsd.org mailing list
> > https://lists.freebsd.org/mailman/listinfo/freebsd-current
> > To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
___
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Re: kqueue send over unix socket?
On Tue, Mar 12, 2019 at 04:10:19PM -0500, Larry Rosenman wrote: > I'm working with Aki Tuomi of Dovecot and he asks: > > I tried to ask if you could ask from some Kernel hacker why I cannot > send kqueue() fd over unix socket, I get "Operation not supported". > > Can anyone help me? What exactly do you want to know? Events registered on a kqueue may contain state associated with the process that registered them. For example, the identifier for some events is a file descriptor, but different processes generally don't share their file descriptor tables. Note that kqueue descriptors are not inherited by the child of a fork() either. ___ freebsd-current@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
Re: kqueue send over unix socket?
On Tue, Mar 12, 2019 at 04:10:19PM -0500, Larry Rosenman wrote: > I'm working with Aki Tuomi of Dovecot and he asks: > > I tried to ask if you could ask from some Kernel hacker why I cannot > send kqueue() fd over unix socket, I get "Operation not supported". Right, because sending kqfd to other process does not make sense. For the same reason kqueue filedescriptors are closed on fork. Issue is that kqueue operates on file descriptors, it stores events and names them by fd you use for registration. So all registered events names become meaningless when process operates on different file descriptor table, which happens after fork() or if kqfd is passed over unix socket to other process. Technically this occurs because kqueue file ops structure does not specify DFLAG_PASSABLE. > > Can anyone help me? > > > > -- > Larry Rosenman http://www.lerctr.org/~ler > Phone: +1 214-642-9640 E-Mail: l...@lerctr.org > US Mail: 5708 Sabbia Dr, Round Rock, TX 78665-2106 > ___ > freebsd-current@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-current > To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org" ___ freebsd-current@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
Re: kqueue send over unix socket?
Is he trying to send the kqueue file descriptor itself using sendmsg
with SCM_RIGHTS? It sounds like kqueues cannot be sent over unix
sockets; not every file type necessarily can. But if you want to know
the nitty-gritty details, just run this:
dtrace -i 'fbt:::return /arg1 == 45/ {stack();}' -c "my_program
my_options" and that will usually tell you the exact function that set
the error.
If the output is too large, then you can filter it by writing a D
program like this:
#sendmsg.d
fbt:kernel:sys_sendmsg:entry
{
this->trigger = 1;
}
fbt:::return
/ this->trigger == 1 && arg1 == 45 /
{
stack();
}
fbt:kernel:sys_sendmsg:return
{
this->trigger = 0;
}
dtrace -s sendmsg.d -c "my_program my_options"
Hope that helps.
-Alan
On Tue, Mar 12, 2019 at 3:22 PM Larry Rosenman wrote:
>
> I'm working with Aki Tuomi of Dovecot and he asks:
>
> I tried to ask if you could ask from some Kernel hacker why I cannot
> send kqueue() fd over unix socket, I get "Operation not supported".
>
> Can anyone help me?
>
>
>
> --
> Larry Rosenman http://www.lerctr.org/~ler
> Phone: +1 214-642-9640 E-Mail: l...@lerctr.org
> US Mail: 5708 Sabbia Dr, Round Rock, TX 78665-2106
> ___
> freebsd-current@freebsd.org mailing list
> https://lists.freebsd.org/mailman/listinfo/freebsd-current
> To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
___
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https://lists.freebsd.org/mailman/listinfo/freebsd-current
To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
kqueue send over unix socket?
I'm working with Aki Tuomi of Dovecot and he asks: I tried to ask if you could ask from some Kernel hacker why I cannot send kqueue() fd over unix socket, I get "Operation not supported". Can anyone help me? -- Larry Rosenman http://www.lerctr.org/~ler Phone: +1 214-642-9640 E-Mail: l...@lerctr.org US Mail: 5708 Sabbia Dr, Round Rock, TX 78665-2106 ___ freebsd-current@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
