[cups-devel] FYI: duplex not working ("Transport endpoint is not connected")

[Martin Vogt]

Hello,

On 01/12/2018 07:15 PM, Michael Sweet wrote:
> My guess is that this is a bug in Qt or Chrome, although we've had no other reports of it.  
> The only time the CUPS APIs will try to connect directly to the device-uri for the PPD 
> is for CUPS-shared printers that have no local PPD...

The error "Transport endpoint" is still present in cups-client 1.6.3 
with cups server 1.6.3 on RHEL.

vogt at lts[~]>which lpoptions
/usr/bin/lpoptions
vogt at lts[~]>rpm -qf /usr/bin/lpoptions
cups-client-1.6.3-29.el7.x86_64

vogt at lts[~]>lpoptions -p cpsg0a -l
lpoptions: Unable to get PPD file for cpsG0a: Transport endpoint is not 
connected

The only difference between working/not working is to configure
the printer on the server as:

[1] ipp://cpsG0a.printers.domain.de:631/ipp (does not work)

[2] socket://cpsG0a.printers.domain.de:9100 (works)


In the case [1] the strace is:

connect(4, {sa_family=AF_INET, sin_port=htons(631), 
sin_addr=inet_addr("192.168.48.101")}, 16) = -1 EINPROGRESS (Operation 
now in progress)
fcntl(4, F_SETFL, O_RDWR)               = 0
poll([{fd=4, events=POLLIN|POLLOUT}], 1, 250) = 1 ([{fd=4, 
revents=POLLIN|POLLOUT|POLLERR|POLLHUP}])
getpeername(4, 0x7fffba6aa5f0, 0x7fffba6aa5dc) = -1 ENOTCONN (Transport 
endpoint is not connected)

In [2] it ask the cups server for the ppd.

connect(4, {sa_family=AF_INET, sin_port=htons(631), 
sin_addr=inet_addr("10.136.16.45")}, 16) = -1 EINPROGRESS (Operation now 
in progress)
fcntl(4, F_SETFL, O_RDWR)

getpeername(4, {sa_family=AF_INET, sin_port=htons(631), 
sin_addr=inet_addr("10.136.16.45")}, [16]) = 0
umask(077)                              = 022
open("/var/tmp/cups1gAkzE", O_RDWR|O_CREAT|O_EXCL, 0600) = 5
umask(022)                              = 077
uname({sysname="Linux", nodename="lts001it.itwm.fhg.de", ...}) = 0
sendto(4, "GET /printers/cpsG0a.ppd HTTP/1."..., 136, 0, NULL, 0) = 1

(lpotions is part of cups)
The net 192.168.x.y is private/not routed and can't be reached from the
network lpoptions is executed.

regards,

Martin