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Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘Mac’ Category

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Getting your public IP address from the command-line when http and https are blocked: use DNS

Posted by jpluimers on 2022/12/28

Years ago, I wrote Getting your public IP address from the command-line. All methods were http based, so were very easy to execute using cURL.

But then in autumn 2021, Chris Bensen wrote this cool little blog-post [Wayback/Archive] Chris Bensen: How do I find my router’s public IP Address from the command line?:

dig -4 TXT +short o-o.myaddr.l.google.com @ns1.google.com

At first sight, I thought it was uncool, as the command was quite long and there was no explanation of the dig command trick.

But then, knowing that dig is a DNS client, it occurred to me: this perfectly works when http and https are disabled by your firewall, but the DNS protocol works and gives the correct result:

# dig -4 TXT +short o-o.myaddr.l.google.com @ns1.google.com
"80.100.143.119"

This added the below commands and aliases to my tool chest for *nix based environments like Linux and MacOS (not sure yet about Windows yet :), but that still doesn’t explain why it worked. So I did some digging…

IPv4

  • command:
    dig -4 TXT +short o-o.myaddr.l.google.com @ns1.google.com
  • command removing outer double quotes:
    dig -4 TXT +short o-o.myaddr.l.google.com @ns1.google.com | xargs
  • alias:
    alias "whatismyipv4_dns=dig -4 TXT +short o-o.myaddr.l.google.com @ns1.google.com | xargs"

IPv6

  • command:
    dig -6 TXT +short o-o.myaddr.l.google.com @ns1.google.com
  • command removing outer double quotes:
    dig -6 TXT +short o-o.myaddr.l.google.com @ns1.google.com | xargs
  • alias:
    alias "whatismyipv6_dns=dig -6 TXT +short o-o.myaddr.l.google.com @ns1.google.com | xargs"

How it works

Let’s stick to dig and IPv4 as that not having IPv6 (regrettably still) is the most common situation today:

# dig -4 TXT +short o-o.myaddr.l.google.com @ns1.google.com
"80.100.143.119"

What it does is request the DNS TXT record of o-o.myaddr.l.google.com from the Google DNS server ns1.google.com and returns the WAN IPv4 address used in the DNS request, which is for instance explained in [Wayback/Archive] What is the mechanics behind “dig TXT o-o.myaddr.l.google.com @ns1.google.com” : linuxadmin.

Since these are TXT records, dig will automatically double quote them, which xargs can remove (see below how and why):

# dig -4 TXT +short o-o.myaddr.l.google.com @ns1.google.com | xargs
80.100.143.119

The DNS query will fail when requesting the Google Public DNS servers 8.8.8.8 or 8.8.4.4:

# dig -4 TXT +short o-o.myaddr.l.google.com @8.8.8.8
"2a00:1450:4013:c1a::103"
"edns0-client-subnet 80.101.239.0/24"

Or, with quotes removed (the -L 1 ensures that xargs performs the quote-pair removal action on each line):

# dig -4 TXT +short o-o.myaddr.l.google.com @8.8.8.8 | xargs -L 1
2a00:1450:4013:c1a::103
edns0-client-subnet 80.101.239.0/24

This request is both slower than requesting the ns1.google.com server and wrong.

The reason is that only ns1.google.com understands the special o-o.myaddr.l.google.com hostname which instructs it to return the IP address of the requesting dig DNS client.

That 8.8.8.8 returns a different IP address and an additional edns0-client-subnet with less accurate information is explained in an answer to [Wayback/Archive] linux – Getting the WAN IP: difference between HTTP and DNS – Stack Overflow by [Wayback/Archive] argaz referring to this cool post: [Wayback/Archive] Which CDNs support edns-client-subnet? – CDN Planet.

Not just ns1.google.com: any DNS server serving the google.com domain

Since o-o.myaddr.l.google.com is part of the google.com domain, the above works for any DNS server serving the google.com domain (more on that domain: [Wayback/Archive] General DNS overview  |  Google Cloud).

Getting the list of DNS servers is similar to getting the list of MX servers which I explained in Getting the IP addresses of gmail MX servers, replacing MX record type (main exchange) with the NS record type (name server) and the gmail.com domain with the google.com domain:

# dig @8.8.8.8 +short NS google.com
ns3.google.com.
ns1.google.com.
ns2.google.com.
ns4.google.com.

The ns1.google.com DNS server is a special one of the NS servers: it is the start of authority server, which you can query using the SOA record type that also gives slightly more details for this server:

# dig @8.8.8.8 +short SOA google.com
ns1.google.com. dns-admin.google.com. 410477869 900 900 1800 60

The difference between using NS and SOA records with dig are explained in the [Wayback] dns – How do I find the authoritative name-server for a domain name? – Stack Overflow answer by [Wayback/Archive] bortzmeyer who also explains how to help figuring out SOA and NS discrepancies (note to self: check out the check_soa tool originally by Michael Fuhr (I could not find recent content of him, so he might have passed away) of which source code is now at [Wayback/Archive] Net-DNS/check_soa at master · NLnetLabs/Net-DNS).

So this works splendid as well using ns4.google.com on my test system:

# dig -4 TXT +short o-o.myaddr.l.google.com @ns4.google.com | xargs
80.100.143.119

The xargs removes outer quotes removal trick

[Wayback/Archive] string – Shell script – remove first and last quote (“) from a variable – Stack Overflow (thanks quite anonymous [Wayback/Archive] user1587520):

> echo '"quoted"' | xargs
quoted

xargs uses echo as the default command if no command is provided and strips quotes from the input.

More on https versus DNS requests

Some notes are in [Wayback/Archive] How to get public IP address from Linux shell, but note the telnet trick now fails as myip.gelma.net is gone (latest live version was archived in the Wayback Machine in august 2019).

Via

–jeroen

Posted in *nix, *nix-tools, Apple, bash, bash, Batch-Files, Communications Development, Development, DNS, Internet protocol suite, Linux, Mac, Mac OS X / OS X / MacOS, Power User, Scripting, Software Development, TCP | Leave a Comment »

The only practical way of running x86 VMs on Apple M1 seems to be QEMU based UTM

Posted by jpluimers on 2022/07/01

Few articles exist on running x86 VMs on Apple M1 architecture.

This is the best I found, and clearly states that QEMU based UTM is the way to go, but notably lacks 3D support: [Wayback/Archive.is] Apple Silicon M1: How to run x86 and ARM Virtual Machines on it? | by Dmitry Yarygin | Mar, 2021 | Medium

Without VMs, but running Windows x86_64 code is already possible using Windows 10 for ARM via Parallels: [Wayback] Windows 10 on M1 Macs: What you can do (virtualization, sorta) and can’t (Boot Camp) | Macworld.

VMware Fusion is not going to support x86_64 virtualisation anytime soon as per [Wayback/Archive.is] Fusion on Apple Silicon: Progress Update – VMware Fusion Blog – VMware Blogs

…

What about x86 emulation?

We get asked regularly about running x86 VMs on M1 Macs. It makes total sense… If Apple can emulate x86 with Rosetta 2, surely VMware can do something too, right?

Well, the short answer is that there isn’t exactly much business value relative to the engineering effort that is required, at least for the time being. For now, we’re laser focused on making Arm Linux VMs on Apple silicon a delight to use.

So, to be a bit blunt, running x86 operating systems on Apple silicon is not something we are planning to deliver with this project. Installing Windows or Linux from an x86 ISO, for example, will not work.

…

More on UTM, which is open source:

Now hopefully someone posts a Wiki of running x86_64 Windows on Apple M1 (:

This is a small start that it can be done [Wayback/Archive.is] Has anyone tried running Delphi on Windows ARM? – Delphi IDE and APIs – Delphi-PRAXiS [en]

It works well. I’ve managed to build and run my VCL and FMX projects on Android, iOS, Windows and Mac without any problems.
Note that both Windows ARM and the way it runs Delphi are still in preview so tread carefully!
On 4/18/2021 at 8:01 PM, Der schöne Günther said:
Can you confirm it cannot only build projects but also debug them?
I can debug Windows and Android no problem. I’m having issues debugging iOS as it’s stopping in the IDE but showing the CPU rather than code views. I believe this might be a badly built component I need to re-install rather than an issue with the environment but can’t confirm either way at the moment.

…

An update on the debugging issues on iOS – it’s all working now. My VM just needed a restart and I can debug without problems now.

--jeroen

Posted in Apple, M1 Mac, Mac, Mac OS X / OS X / MacOS, Power User, Qemu, UTM, Virtualization, Windows, Windows 10 | Leave a Comment »

Kris on Twitter is a bit radical against shell scripts. Learn why.

Posted by jpluimers on 2022/04/13

I say to people: only use shell interactively, don’t write scripts. Never. Not one.
But Kris, they ask, why so radical?
Because of this:

is the literal English Google Translation of the German text

Ich sage den Leuten: benutzt Shell nur interaktiv, schreibt keine Scripte. Nie. Nicht eines.
Aber Kris, fragen sie, wieso so Radikal?
Deswegen:

then links to [Wayback/Archive] Jan Schaumann on Twitter: “TIL zgrep(1) is a shell script. BSD basically does “zcat | grep”, but GNU does “gzip -dc | sed”. How did I learn that? The fun way! CVE-2022-1271, arbitrary-file-write and code execution vulnerability in GNU zgrep / gzip. …”:

Read the rest of this entry »

Posted in *nix, *nix-tools, Apple, ash/dash, ash/dash development, bash, bash, BSD, Development, Mac, Mac OS X / OS X / MacOS, Power User, Scripting, Software Development | Leave a Comment »

Cleaning the cooling fans of a 15-inch Retina MacBook Pro 2015 model

Posted by jpluimers on 2022/03/14

After years of use, the cooling fans of my 15-inch Retina MacBook Pro 2015 model got quite a bit dirty, causing them to run louder and louder.

The video below the fold shows how to clean them: 11 screws, some isopropyl alcohol, (dry!) compressed, and caution for the connector-clips connecting the bottom plate.

It helps having a:

  • pentalobe P5 screwdriver
  • plastic spudger so separate the bottom plate (especially be careful with the connector-clips)
  • magnet to stick the screws to, as they are really tiny and it is easy to loose them

I got the pentalobe screwdriver with some spare screws from the German Amazon: [Archive.is] Kricson Ersatzschrauben MacBook Pro – 4 Pack Gummi: Amazon.de: Computer & Zubehör

You can get a similar one from the USA Amazon site: [Archive.is] Amazon.com: 8 Pack Rubber Case Feet + Set of 20pcs Repair Replacement Screw + 1pcs 5 Point Pentalobe Screwdriver for Unibody MacBook Pro Retina A1425 A1502 A1398 13″ 15″ Bottom Case(Retina): Computers & Accessories

Two important tips:

  • After using isopropyl alcohol, let the parts dry
  • Hold the fans when spraying compressed air (to prevent the fan-motors to create over-voltage, and to prevent the fans spinning faster than they are rated for)

The iFixit pictures for replacing the SSD help greatly to see how to remove and re-attach the back-cover, and where the various parts are inside the machines.

Note the screws differ between the 13-inch and 15-inch models!

–jeroen

Read the rest of this entry »

Posted in Apple, Mac, MacBook, MacBook Retina, MacBook-Air, MacBook-Pro, Power User | Leave a Comment »

Character set reencoding link archive

Posted by jpluimers on 2022/02/10

I will likely need some of these links in the future:

–jeroen

Posted in Apple, Development, Encoding, Mac, Mac OS X / OS X / MacOS, Power User, Software Development, Unicode | Leave a Comment »

dd on MacOS / OS X with progress report

Posted by jpluimers on 2022/01/21

Since dd on Apple does not support progress parameters via [Wayback] macos dd progress – Google Search:

  • [Wayback] Quick: dd with progress indication on macOS

    A nice way I found to get progress indication whilst still being able to benefit from the huge speed increase in using /dev/rdiskX is to install a tool called pv, also known as [WayBack] Pipe Viewer.

    Example:

    sudo dd if=/dev/rdiskX bs=1m | pv -s 64G | sudo dd of=/dev/rdiskY bs=1m

    Another way to achieve something similar would be to use brew to install coreutils, which will come with a newer version of dd that supports the status option.

    Example:

    gdd if=/dev/diskX of=/dev/diskY bs=1m status=progress

  • [Wayback] el capitan – How can I track progress of dd – Ask Different

    You just need to enter a controlT character from the keyboard while the dd command is executing.

    By pressing the controlT character, you are sending the same SIGINFO signal to the dd command that the command pkill -INFO -x dd sends.

     

    dd itself doesn’t provide a progress bar. You may estimate the progress of the dd copy process by adding a pkill -INFO command though.

    Example:

    dd if=/dev/zero of=/dev/null bs=64m count=1000 & while pkill -INFO -x dd; do sleep 1; done
  • [Wayback] dd progress indicator on OSX

    signal siginfo is coupled to key-combination CTRL-T. No need to use kill, you can just type CTRL-T in the terminal window where dd is running.

–jeroen

Posted in *nix, *nix-tools, Apple, iMac, Mac, Mac OS X / OS X / MacOS, MacBook, MacBook Retina, MacBook-Air, MacBook-Pro, MacMini, Power User | Leave a Comment »

Need to revisit osquery: SQL powered operating system instrumentation, monitoring, and analytics supports more platforms and also aggregates to central log locations

Posted by jpluimers on 2022/01/18

Almost two years ago, GitHub – facebook/osquery: SQL powered operating system instrumentation, monitoring, and analytics published from the automatic blog queue.

It was in the midst of my rectum cancer treatment, so I was glad the blog queue back then was still about 18 months deep.

This meant I looked into osquery in 2018, which I remember because I needed it on MacOS as I did not want to remember the syntax for MacOS specific commands on getting system information. It also coincides with how much my repository fork was behind: [Wayback: jpluimers/osquery commits/Archive: jpluimers/osquery commits].

Fast forward to now, the breath of systems I’m involved with has widened, so I was glad to see that Kristian Köhntopp mentioned it:

So time to try it again (:

The links he mentioned:

  • [Wayback/Archive] Welcome to osquery – osquery

    osquery is an operating system instrumentation framework for Windows, OS X (macOS), Linux, and FreeBSD. The tools make low-level operating system analytics and monitoring both performant and intuitive.

  • [Wayback/Archive] Welcome to osquery – osquery: High Level Features
    The high-performance and low-footprint distributed host monitoring daemon, osqueryd, allows you to schedule queries to be executed across your entire infrastructure. The daemon takes care of aggregating the query results over time and generates logs which indicate state changes in your infrastructure. You can use this to maintain insight into the security, performance, configuration, and state of your entire infrastructure. osqueryd‘s logging can integrate into your internal log aggregation pipeline, regardless of your technology stack, via a robust plugin architecture.
    The interactive query console, osqueryi, gives you a SQL interface to try out new queries and explore your operating system. With the power of a complete SQL language and dozens of useful tables built-in, osqueryi is an invaluable tool when performing incident response, diagnosing a systems operations problem, troubleshooting a performance issue, etc.
  • [Wayback/Archive] osqueryd (daemon) – osquery
  • [Wayback/Archive] osqueryi (shell) – osquery
  • [Wayback/Archive] Aggregating Logs – osquery
  • [Wayback/Archive] AWS Logging – osquery

Main site: [Wayback/Archive] osquery | Easily ask questions about your Linux, Windows, and macOS infrastructure

Repository: [Wayback/Archive] osquery/osquery: SQL powered operating system instrumentation, monitoring, and analytics.

–jeroen

Posted in *nix, *nix-tools, Apple, Development, DevOps, Facebook, Infrastructure, Mac, Mac OS X / OS X / MacOS, Power User, SocialMedia, Software Development, Windows | Leave a Comment »

Getting the primary IP address (plain and CIDR) on Linux and OS X, then nmap scan on the associated subnet

Posted by jpluimers on 2021/12/13

The below answer works on my Linux and OS X systems (each having multiple network adapters configured):

[WayBack] bash – How to get the primary IP address of the local machine on Linux and OS X? – Stack Overflow

ip route get 1 | awk '{print $NF;exit}'

For Linux, I have this bash function:

# note the ";exit" lists the first default route interface, as there can be multiple
function nmap-fingerprint_network_of_default_interface() {
        default_if=$(ip route list | awk '/^default/ {print $5;exit}')
        default_if_cidr=$(ip -o -f inet addr show $default_if | awk '{print $4}')
        nmap -sP $default_if_cidr
}

And for OS X this one:

# requires ipcalc
function nmap-fingerprint_network_of_default_interface() {
        default_if=$(route -q -n get default | awk '/interface:/ {print $2;exit}')
        default_if_address=$(ifconfig $default_if | awk '/inet / {print $2;exit}')
        default_if_netmask_hex=$(ifconfig $default_if | awk '/inet / {print $4;exit}')
        default_if_network_bit_count=$(ipcalc --nocolor --class $default_if_address $default_if_netmask_hex)
        default_if_cidr=$(echo "$default_if_address/$default_if_network_bit_count")
        nmap -sP $default_if_cidr
}

These are the variables used:

  • default_if: network interface of the default route
  • default_if_cidr: IPv4 CIDR of the network interface of the default route (see Classless Inter-Domain Routing: CIDR notation – Wikipedia)
  • default_if_address: IPv4 address of network interface of the default route
  • default_if_netmask_hex: hexadecimal IPv4 network mask of network interface of the default route
  • default_if_network_bit_count: number of set bits in the IPv4 network mask of the network interface of the default route

Links used to get the above functions:

I might have gotten away with a pure bash solution (see [WayBack] Bash script for calculating network and broadcast addresses from ip and netmask or CIDR Notation · GitHub or my post Getting your local IPv4 addresses, netmasks and CIDRs), but the above works and is way shorter, and easier to maintain.

In stead of ipcalc, subnetcalc can do the same calculations and also supports IPv6, so that is something for a future try:

–jeroen

Posted in *nix, *nix-tools, Apple, bash, Color (software development), Development, Mac, Mac OS X / OS X / MacOS, Power User, Scripting, Software Development | Leave a Comment »

2 x Speakers surround replacement – Designed for Apple G4 Cube M7963 | eBay

Posted by jpluimers on 2021/05/24

For my link archive: [Wayback/Archive.is] 2 x Speakers surround replacement – Designed for Apple G4 Cube M7963 | eBay

2 x Speakers surround replacement - Designed for Apple G4 Cube M7963

Via: [Archive.is] Power Macintosh G4 Cube Owners Group : Hi Guys. Just for you to be aware, this is my product, specifically designed and produced by me to repair the Apple G4 Cube speakers | Facebook

–jeroen

Posted in Apple, Mac, Power Mac, Power Mac G4 Cube, Power User | Leave a Comment »

MacOS: when “Command-Tab” does not work (no visual response, no application switching) you need to restart the Dock

Posted by jpluimers on 2021/05/21

Based on [WayBack] Command-Tab Not working….. – Apple Community

If you go to Activity monitor and search for dock, doubleclick on it, choose Force quit.
It will restart the Dock app and now it should work.

I wrote this alias which restarts Dock (including Dashboard and Spaces as they are served by the same process).

alias restart-dock-dashboard-spaces='killall -KILL Dock'

Related: my 2013 post Mac: Restarting the Mac OS X Dock, Finder, Spaces or Menubar | Stefan Ernst.

–jeroen

Posted in Apple, iMac, Mac, Mac OS X / OS X / MacOS, MacBook, MacBook Retina, MacBook-Air, MacBook-Pro, MacMini, macOS 10.12 Sierra, macOS 10.13 High Sierra, OS X 10.10 Yosemite, Power User | Leave a Comment »

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