Splitting with a long URL and a pipe

[Bundy01]

Hi,

I've seen this problem with long addresses.

With a pipe

echo gejgeigjegjegjergjegjebjbeeorigthjrzpogiêprjyhrr.rhrh.vfvfocus.uho.com.twear.com.twelderlysd.comdrhearing.comhkhearingspeech.comepaper.ntuh.govphonak.com.hkodcb.org.hkhearingaids.com.hkweb2.ctsh.hcc.edu.tw.stu98erdo.ccdharmazen.orgpubu.com.twzh.wikipedia.org.wiki.facebook.co|fping   
gejgeigjegjegjergjegjebjbeeorigthjrzpogiêprjyhrr.rhrh.vfvfocus.uho.com.twear.com.twelderlysd.comdrhearing.comhkhearingspeech.comep: Name or service not known
aper.ntuh.govphonak.com.hkodcb.org.hkhearingaids.com.hkweb2.ctsh.hcc.edu.tw.stu98erdo.ccdharmazen.orgpubu.com.twzh.wikipedia.org.wi: Name or service not known
ki.facebook.co is alive

Without a pipe, it's OK

fping gejgeigjegjegjergjegjebjbeeorigthjrzpogiêprjyhrr.rhrh.vfvfocus.uho.com.twear.com.twelderlysd.comdrhearing.comhkhearingspeech.comepaper.ntuh.govphonak.com.hkodcb.org.hkhearingaids.com.hkweb2.ctsh.hcc.edu.tw.stu98erdo.ccdharmazen.orgpubu.com.twzh.wikipedia.org.wiki.facebook.co                                 
gejgeigjegjegjergjegjebjbeeorigthjrzpogiêprjyhrr.rhrh.vfvfocus.uho.com.twear.com.twelderlysd.comdrhearing.comhkhearingspeech.comepaper.ntuh.govphonak.com.hkodcb.org.hkhearingaids.com.hkweb2.ctsh.hcc.edu.tw.stu98erdo.ccdharmazen.orgpubu.com.twzh.wikipedia.org.wiki.facebook.co: Name or service not known

I modified the valid URL by adding random letters at the beginning to display the message Name or service not known because I'm using it in a script.
Because of this bug I can't test all the addresses I want (I limit to 132 max characters).

Regards.

[auerswal]

Thanks for the report!

You should be able to work around this issue by using xargs:

$ echo gejgeigjegjegjergjegjebjbeeorigthjrzpogiêprjyhrr.rhrh.vfvfocus.uho.com.twear.com.twelderlysd.comdrhearing.comhkhearingspeech.comepaper.ntuh.govphonak.com.hkodcb.org.hkhearingaids.com.hkweb2.ctsh.hcc.edu.tw.stu98erdo.ccdharmazen.orgpubu.com.twzh.wikipedia.org.wiki.facebook.co | xargs fping
gejgeigjegjegjergjegjebjbeeorigthjrzpogiêprjyhrr.rhrh.vfvfocus.uho.com.twear.com.twelderlysd.comdrhearing.comhkhearingspeech.comepaper.ntuh.govphonak.com.hkodcb.org.hkhearingaids.com.hkweb2.ctsh.hcc.edu.tw.stu98erdo.ccdharmazen.orgpubu.com.twzh.wikipedia.org.wiki.facebook.co: Name or service not known

This name is too long for DNS anyway. I am not convinced that fping needs to accept names longer than permissible for DNS on standard input or from a file, I'd say it suffices for fping to accept names acceptable for DNS. I am considering to increase the respective size limit in fping.

That fping splits this long name into three parts and adds every one as a target seems to be a bug. I intend to look into diagnosing and rejecting too long input lines instead.

[Bundy01]

It has nothing to do with this bug, but I'd like to know about messages other than is a live.

I counted 4 of them:

1. Name or service not known
2. No address associated...
3. Temporary failure...
4. is unreachable

Can you tell me if there are others and what the difference is between these different states?

[auerswal]

I am working on a fix for the line-splitting bug and made some progress, but I am not yet sure it works as intended. At least I need more time for testing.

@Bundy01, regarding your question:

Items 1, 2, and 3 on your list are returned by gai_strerror() after getaddrinfo() has failed. They all describe reasons why the name could not be resolved into at least one IP address. These descriptions come from the C Library (e.g., the GNU C Library on GNU/Linux), not fping. See line 2686 in fping.c:

fping/src/fping.c

Line 2686 in cb83286

print_warning("%s: %s\n", name, gai_strerror(ret_ga));

Item 4 on your list means that the target name could be resolved to at least one IP address, at least one ICMP request was sent to to that IP address, but fping did not receive any reply. This is normal fping output.

[Bundy01]

@auerswal: thanks 👍