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* [PATCH ucspi-vsock] vsockclient: allow null application
@ 2021-03-24 18:24 Alyssa Ross
  2021-03-24 18:44 ` Cole Helbling
  0 siblings, 1 reply; 4+ messages in thread
From: Alyssa Ross @ 2021-03-24 18:24 UTC (permalink / raw)
  To: devel

I found myself running

    vsockclient 2 1024 true

in a situation where it just mattered that a connection was made, and
no data needed to be exchanged of it.  That I found myself doing this
is quite a strong indicator that the program to exec into should be
optional.

UCSPI-1996[1] doesn't specify what should happen if no application is
provided, so I think this is a reasonable interpretation.  I'm not
sure if I feel the same for vsockserver(d), so I haven't made the
corresponding change there.  I'll wait to see if there's ever a need
for it.

[1]: https://cr.yp.to/proto/ucspi.txt
---
 vsockclient.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/vsockclient.c b/vsockclient.c
index 934cfa0..456810d 100644
--- a/vsockclient.c
+++ b/vsockclient.c
@@ -41,11 +41,9 @@ int main(int argc, char *argv[])
 		}
 	}
 
-	// Check there are enough positional arguments (two for the
-	// address and at least one to exec into).
-	if (optind > argc - 3)
+	// Find the address (cid and port) to connect to.
+	if (optind > argc - 2)
 		ex_usage();
-
 	if (getu32(argv[optind++], 0, UINT32_MAX, &rcid))
 		ex_usage();
 	if (getu32(argv[optind++], 0, UINT32_MAX, &rport))
@@ -69,6 +67,11 @@ int main(int argc, char *argv[])
 		     "connect to %" PRIu32 ":%" PRIu32 " failed", rcid, rport);
 	ilog("connected to %" PRIu32 ":%" PRIu32 "!", rcid, rport);
 
+	// If we have nothing to exec into, we're done.  (Sometimes
+	// just connecting on its own is enough.)
+	if (optind == argc)
+		return 0;
+
 	// Set up the file descriptors to the well-known UCSPI numbers.
 	if (dup2(fd, 6) == -1)
 		diee(EX_OSERR, "dup2");
-- 
2.30.0

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH ucspi-vsock] vsockclient: allow null application
  2021-03-24 18:24 [PATCH ucspi-vsock] vsockclient: allow null application Alyssa Ross
@ 2021-03-24 18:44 ` Cole Helbling
  2021-03-24 19:52   ` Alyssa Ross
  0 siblings, 1 reply; 4+ messages in thread
From: Cole Helbling @ 2021-03-24 18:44 UTC (permalink / raw)
  To: Alyssa Ross, devel

On Wed Mar 24, 2021 at 11:24 AM PDT, Alyssa Ross wrote:
> I found myself running
>
>     vsockclient 2 1024 true
>
> in a situation where it just mattered that a connection was made, and
> no data needed to be exchanged of it.  That I found myself doing this
> is quite a strong indicator that the program to exec into should be
> optional.
>
> UCSPI-1996[1] doesn't specify what should happen if no application is
> provided, so I think this is a reasonable interpretation.  I'm not
> sure if I feel the same for vsockserver(d), so I haven't made the
> corresponding change there.  I'll wait to see if there's ever a need
> for it.
>
> [1]: https://cr.yp.to/proto/ucspi.txt
> ---
>  vsockclient.c | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)

Reviewed-by: Cole Helbling <cole.e.helbling@outlook.com>

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH ucspi-vsock] vsockclient: allow null application
  2021-03-24 18:44 ` Cole Helbling
@ 2021-03-24 19:52   ` Alyssa Ross
  2021-03-24 19:53     ` Alyssa Ross
  0 siblings, 1 reply; 4+ messages in thread
From: Alyssa Ross @ 2021-03-24 19:52 UTC (permalink / raw)
  To: Cole Helbling; +Cc: devel

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> On Wed Mar 24, 2021 at 11:24 AM PDT, Alyssa Ross wrote:
>> I found myself running
>>
>>     vsockclient 2 1024 true
>>
>> in a situation where it just mattered that a connection was made, and
>> no data needed to be exchanged of it.  That I found myself doing this
>> is quite a strong indicator that the program to exec into should be
>> optional.
>>
>> UCSPI-1996[1] doesn't specify what should happen if no application is
>> provided, so I think this is a reasonable interpretation.  I'm not
>> sure if I feel the same for vsockserver(d), so I haven't made the
>> corresponding change there.  I'll wait to see if there's ever a need
>> for it.
>>
>> [1]: https://cr.yp.to/proto/ucspi.txt
>> ---
>>  vsockclient.c | 11 +++++++----
>>  1 file changed, 7 insertions(+), 4 deletions(-)
>
> Reviewed-by: Cole Helbling <cole.e.helbling@outlook.com>

Committed as d24ff2d. :)

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^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH ucspi-vsock] vsockclient: allow null application
  2021-03-24 19:52   ` Alyssa Ross
@ 2021-03-24 19:53     ` Alyssa Ross
  0 siblings, 0 replies; 4+ messages in thread
From: Alyssa Ross @ 2021-03-24 19:53 UTC (permalink / raw)
  To: Cole Helbling; +Cc: devel

[-- Attachment #1: Type: text/plain, Size: 901 bytes --]

Alyssa Ross <hi@alyssa.is> writes:

>>> I found myself running
>>>
>>>     vsockclient 2 1024 true
>>>
>>> in a situation where it just mattered that a connection was made, and
>>> no data needed to be exchanged of it.  That I found myself doing this
>>> is quite a strong indicator that the program to exec into should be
>>> optional.
>>>
>>> UCSPI-1996[1] doesn't specify what should happen if no application is
>>> provided, so I think this is a reasonable interpretation.  I'm not
>>> sure if I feel the same for vsockserver(d), so I haven't made the
>>> corresponding change there.  I'll wait to see if there's ever a need
>>> for it.
>>>
>>> [1]: https://cr.yp.to/proto/ucspi.txt
>>> ---
>>>  vsockclient.c | 11 +++++++----
>>>  1 file changed, 7 insertions(+), 4 deletions(-)
>>
>> Reviewed-by: Cole Helbling <cole.e.helbling@outlook.com>
>
> Committed as d24ff2d. :)

Whoops, I mean 8d75b0f.

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^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2021-03-24 19:53 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-03-24 18:24 [PATCH ucspi-vsock] vsockclient: allow null application Alyssa Ross
2021-03-24 18:44 ` Cole Helbling
2021-03-24 19:52   ` Alyssa Ross
2021-03-24 19:53     ` Alyssa Ross

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