• FauxPseudo @lemmy.world
    2494·
    11 months ago

    Ok. This covers every ipv6 and ipv4 address.

    “^\s*((([0-9A-Fa-f]1,4}:){7}([0-9A-Fa-f]{1,4}:))|(([0-9A-Fa-f]{1,4:)6}(:[0-9A-Fa-f]{1,4}((25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])(.(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])){3)|:))|(([0-9A-Fa-f]1,4}:){5}(((:[0-9A-Fa-f]{1,4}){1,2}):((25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])(.(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])){3)|:))|(([0-9A-Fa-f]1,4}:){4}(((:[0-9A-Fa-f]{1,4}){1,3})((:[0-9A-Fa-f]{1,4)?:((25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])(.(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9]))3})):))|(([0-9A-Fa-f]{1,4:)3}(((:[0-9A-Fa-f]{1,4}){1,4})((:[0-9A-Fa-f]{1,4)0,2}:((25[0-5]2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])(.(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])){3))|:))|(([0-9A-Fa-f]1,4}:){2}(((:[0-9A-Fa-f]{1,4}){1,5})((:[0-9A-Fa-f]{1,4)0,3}:((25[0-5]2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])(.(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])){3))|:))|(([0-9A-Fa-f]1,4}:){1}(((:[0-9A-Fa-f]{1,4}){1,6})((:[0-9A-Fa-f]{1,4)0,4}:((25[0-5]2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])(.(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])){3))|:))|(:(((:[0-9A-Fa-f]1,4}){1,7})((:[0-9A-Fa-f]{1,4)0,5}:((25[0-5]2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])(.(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])){3))|:)))(%.+)?\s*$”

    • Danny M@lemmy.escapebigtech.info
      692·
      11 months ago

      Please don’t. Use regex to find something that looks like an IP then build a real parser. This is madness, its’s extremely hard to read and a mistake is almost impossible to spot. Not to mention that it’s slow.

      Just parse [0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3} using regex (for v4) and then have some code check that all the octets are valid (and store the IP as a u32).

        • azertyfun@sh.itjust.works
          1·
          11 months ago

          Fuck that, if for whatever reason I’m writing an IP validator by hand I’m disallowing leading zeros. Parsers are very inconsistent, some will parse 010 as 10, others as 0o10 == 8 (you can try that right now with a POSIX ping). Talk about a footgun.

        • Danny M@lemmy.escapebigtech.info
          0·
          11 months ago

          Definitely, tho if you store it as a u32 that is fixed magically. Because 1.2.3.4 and 1.02.003.04 both map to the same number.

          What I mean by storing it as a u32 is to convert it to a number, similar to how the IP gets sent over the wire, so for v4:

          octet[3] | octet[2] << 8 | octet[1] << 16 | octet[0] << 24

          or in more human terms:

          (fourth octet) + (third octet * 256) + (second octet * 256^2) + (first octet * 256^3)
          • p1mrx@sh.itjust.works
            1·
            11 months ago

            Because 1.2.3.4 and 1.02.003.04 both map to the same number.

            But 10.20.30.40 and 010.020.030.040 map to different numbers. It’s often best to reject IPv4 addresses with leading zeroes to avoid the decimal vs. octal ambiguity.

      • Centillionaire@kbin.social
        661·
        11 months ago

        That would allow for like, 2 trillion devices? Feels like a bandaid, my dude. Next you’re gonna suggest a giant ice cube in the ocean once a year to stop global warming.

        • stoy@lemmy.zip
          11·
          11 months ago

          So add two more octets:

          Moat companies will still just use something like 10.0.13.37.0.1

            • stoy@lemmy.zip
              24·
              11 months ago

              Never claimed it was, please quote me where I said as much

              • dohpaz42@lemmy.worldEnglish
                141·
                11 months ago

                My dude, you used the 10.xx private IP as an example. Why wouldn’t they assume you were referring to internal networks?

                • stoy@lemmy.zip
                  11·
                  11 months ago

                  I thought it was pretty clear with me adding 13.37 that I was making a joke, the earlier post spoke about how just adding one octet would still be too few addresses, so I joked about adding one more octet.

          • intensely_human@lemm.ee
            5·
            11 months ago

            Hurricanes cannot cross the equator. The equator is an imaginary line, and hence has zero mass. We can end every hurricane using zero point zero energy (0.0).

        • alienzx@feddit.nlEnglish
          11·
          11 months ago

          You could follow this logic and add 2 alphanumeric digits before 4 numeric octets. E.g. xf.192.168.1.1

          This would at least keep it looking like an IP and not a Mac address. Another advantage would be graceful ipv4 handling with a reserved range starting with “ip” like ip.10.10.10.1

      • Nalivai@discuss.tchncs.de
        15·
        11 months ago

        Oh yeah, great, let’s change the fundamental protocol on which all the networks in the world are based. Now two third of the devices in the world crashed because you tried to ping 192.168.0.0.1

      • Patches@sh.itjust.works
        11·
        11 months ago

        Made that joke in an interview once.

        They didn’t think it was funny. They truly thought Regex was the solution to, but never the cause of, all problems.

        They wanted to make a Regex to verify every single address in the world. Dodged a bullet

        • rob64@startrek.website
          5·
          11 months ago

          Holy hell yeah you did. How would you go about doing that in a single expression? A bunch of back references to figure out the country? What if that’s not included? Oy.

          • Patches@sh.itjust.works
            4·
            11 months ago

            You wouldn’t. It’s not possible. Which is what I told them.

            And why would you want to? Legally if you change the given address, and it fails to get delivered - that is on you. Not them.

            Some countries have addresses that are literally ‘Last house on the left by the Big Tree. Bumban(Neighborhood). NN (Country)’. Any US Centric validation would fail this but I assure you - mail gets delivered just fine.

    • Mr_Dr_Oink@lemmy.world
      5·
      11 months ago

      Remember, when we abbreviate an ipv6 address all leading zeros are reduced to a single 0.

      E.g

      0003 would just become 03

      When there are geoups of 4 zeros these can be represented as a single 0 or as a double colon ::

      But we can only use the :: once so when summarizing an address containing multiple groups of 4 0s one after the other they can all be abbreviated to a single ::

      Eg

      fe80:0000:0000:0000:0210:5aff:feaa:20a2 would become fe80::210:5aff:feaa:20a2

      Therefore it is perfectly valid to abbreviate an address of 0000:0000:0000:0000:0000:0000:0000:0000 /0 to just ::/0

      • Static_Rocket@lemmy.worldEnglish
        2·
        11 months ago

        Eh, I’ve seen some software internally prefer 0::0 instead of just ::0 or :: . Notation wise though you are correct, it is unnecessary.