[Feature Request]Support collapsed zeroes format for ipv6 host addresses (i.e. ::1 for 0:0:0:0:0:0:0:1) #537

jshort · 2022-10-12T23:33:36Z

Now that the et terminal client supports ipv6 host positional args (with or without port specified), we should move the host argument parsing logic out of main() into a helper that has more powerful ipv6 parsing logic (not just counting 7 colons or 8 colons if a port is specified.

ipv4 ip or hostname will have at most 1 colon (if a port is specified).

ipv6 ip will have at least 2 colons (for a collapsed form with no port specified) and up to 8 if the address is fully expressed and a port is specified.

Ex:

1::1 => 1:0:0:0:0:0:0:1 (default port)
[1::1]:2022 => 1:0:0:0:0:0:0:1 (port 2022) (need brackets though this format is not supported by OpenSSH
1:1:1:1:1:1::1 => 1:1:1:1:1:1:0:1 (default port)

jshort · 2022-10-13T16:43:18Z

So OpenSSH decided not to support ipv6 addresses with ports specified in the host positional argument. However, it is standard, particularly if there is a :: in the address, to support [ipv6_addr]:port in say a URL. Et can do one of 3 options:

support this bracketed format exclusively for ipv6 (with or without a port or :: abbreviation)
support fully expanded ipv6 address without square brackets (with or without port...this is current the case after Support for ipv6 addresses (with or without port specified) #536) and partially expanded ipv6 addresses without square brackets but with no port and finally, partially expanded ipv6 addresses in square brackets with a port specified
support passing an ipv6 host argument (expanded or not) without square brackets but not with a port (you must pass --port for ipv6 addresses)

I'm leaning towards the first option (particularly since OpenSsh makes you pass -p or set Port in your ssh config file if you want a non-standard ssh port with an ipv6 address). Or even the third.

The 2nd option is complicated and hard to document in the small --help menu of a cli executable.

Remember that the port specified by the host positional arg or the -p of the et client is the port for etserver not ssh. The ssh port is either default (22) or determined from --ssh-option or your .ssh/config file.

EDIT: Yuck, the shell will require that you quote your argument if you pass square brackets for an ipv6 address. Maybe I'm leaning towards option 3 :). Or maybe a hybrid of option 2 where if you pass an ipv6 address with ::, you cannot set port in the host arg and must do so in the -p option.

Help output: ``` $> ./et --help Remote shell for the busy and impatient Usage: et [OPTION...] [user@]host[:port] Note that 'host' can be a hostname or ipv4 address with or without a port or an ipv6 address. If the ipv6 address is abbreviated with :: then it must be specfied without a port (use -p,--port). -h, --help Print help --version Print version -u, --username Username --host arg Remote host name ... ``` Tests: ``` $> ./et ::1 -p 8080 --macserver $> ./et 0:0:0:0:0:0:0:1 -p 8080 --macserver $> ./et 0:0:0:0:0:0:0:1:8080 --macserver $> ./et ::1 -p 8080 --macserver # fails because defaults to port 2022 ``` Fixes MisterTea#537

This will support ipv6 addresses that are abbreviated with `::` such as ::1 (for 0:0:0:0:0:0:0:1) with some caveats around specifying the port in the host positional argument. Help output: ``` $> ./et --help Remote shell for the busy and impatient Usage: et [OPTION...] [user@]host[:port] Note that 'host' can be a hostname or ipv4 address with or without a port or an ipv6 address. If the ipv6 address is abbreviated with :: then it must be specfied without a port (use -p,--port). -h, --help Print help --version Print version -u, --username Username --host arg Remote host name ... ``` Tests: ``` $> ./et ::1 -p 8080 --macserver $> ./et 0:0:0:0:0:0:0:1 -p 8080 --macserver $> ./et 0:0:0:0:0:0:0:1:8080 --macserver $> ./et ::1 -p 8080 --macserver # fails because defaults to port 2022 ``` Fixes MisterTea#537

This will support ipv6 addresses that are abbreviated with `::` such as ::1 (for 0:0:0:0:0:0:0:1) with some caveats around specifying the port in the host positional argument. Help output: ``` $> ./et --help Remote shell for the busy and impatient Usage: et [OPTION...] [user@]host[:port] Note that 'host' can be a hostname or ipv4 address with or without a port or an ipv6 address. If the ipv6 address is abbreviated with :: then it must be specfied without a port (use -p,--port). -h, --help Print help --version Print version -u, --username Username --host arg Remote host name ... ``` Tests: ``` $> ./et ::1 -p 8080 --macserver $> ./et 0:0:0:0:0:0:0:1 -p 8080 --macserver $> ./et 0:0:0:0:0:0:0:1:8080 --macserver $> ./et ::1 -p 8080 --macserver # fails because defaults to port 2022 ``` Fixes #537

jshort mentioned this issue Oct 13, 2022

ipv6 abbreviated address support #539

Merged

MisterTea closed this as completed in #539 Oct 13, 2022

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[Feature Request]Support collapsed zeroes format for ipv6 host addresses (i.e. ::1 for 0:0:0:0:0:0:0:1) #537

[Feature Request]Support collapsed zeroes format for ipv6 host addresses (i.e. ::1 for 0:0:0:0:0:0:0:1) #537

jshort commented Oct 12, 2022 •

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jshort commented Oct 13, 2022 •

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[Feature Request]Support collapsed zeroes format for ipv6 host addresses (i.e. ::1 for 0:0:0:0:0:0:0:1) #537

[Feature Request]Support collapsed zeroes format for ipv6 host addresses (i.e. ::1 for 0:0:0:0:0:0:0:1) #537

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jshort commented Oct 12, 2022 • edited Loading

jshort commented Oct 13, 2022 • edited Loading

jshort commented Oct 12, 2022 •

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jshort commented Oct 13, 2022 •

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