The Wiert Corner – irregular stream of stuff

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

  • My badges

  • Twitter Updates

    Error: Twitter did not respond. Please wait a few minutes and refresh this page.

  • My Flickr Stream

  • Pages

  • All categories

  • Enter your email address to subscribe to this blog and receive notifications of new posts by email.

    Join 1,616 other followers

Archive for October 25th, 2017

roelandjansen/pcmos386v501: PC-MOS/386 v5.01 final release including cdrom driver sources.

Posted by jpluimers on 2017/10/25

History: Borland C++ source code for the PC-MOS/386 5.01 version at roelandjansen/pcmos386v501: PC-MOS/386 v5.01 final release including cdrom driver sources.

Related:

–jeroen

Via: [WayBack/Archive.is] PC-MOS/386 is na dertig jaar opensourcesoftware – Computer – .Geeks – Tweakers

Posted in Borland C++, C, C++, Development, History, Software Development | Leave a Comment »

cURL – POST an XML file as a stream

Posted by jpluimers on 2017/10/25

I hope I’m not alone on this but I find the cURL documentation hard to follow and short on examples.

My goal was to mimic some HTTP XML posting traffic a server gets from IoT devices. Google Chrome Postman (or Postman REST Client) reproduction is very easy and will send.

TL;DR

  1. ensure you have an empty --header "Content-Type:" header: this ensures that cURL doesn’t add one and does not mess on how the content is being transferred.
  2. use the --data or --data-binary command with an @ to post a file as body.
  3. if you want --write-out then be sure you have a recent cURL version.

This is how the IoT or Postman will send.

  • Post headers like these:

Host:127.0.0.1:8080
Content-Length: 245
Connection:Keep-Alive

  • Content like this:

The data is being streamed to the HTTP server even with the very limited set of headers.

I’ve been unable to come up with exact cURL statement that exactly matches the headers and way the content is being transferred.

This is what I tried (in all examples, %1 is the IPv4 address of the HTTP 1.1 server):

  • POST with the all the headers and the --data command:

curl --request POST --header "Host: %1:8080" --header "Content-Length: 245" --header "Connection: Keep-Alive" --data @httpPostSample.xml http://%1:8080/target

This will hang the connection: somehow cURL will never notify the upload is done and the HTTP server keeps waiting. When you put --verbose or --trace-ascii - on the command-line you will see something like this before hanging: * upload completely sent off: 245 out of 245 bytes.

Note the trick to emit the ASCII trace to stdout using --trace-ascii with the minus sign: thanks to [WayBack] Daniel Stenberg for answering [WayBackHow can I see the request headers made by curl when sending a request to the server? – Stack Overflow.

You can do the same with --trace which dumps all characters (not only ASCII) including their HEX representation

  • POST with the all but the Content-Length headers and the --data command:

curl --request POST --header "Host: %1:8080" --header "Connection: Keep-Alive" --data @httpPostSample.xml http://%1:8080/target

This will automatically add a Content-Length: 245 header and complete the transfer. But it will also add a Content-Type: application/x-www-form-urlencoded header causing the content not being posted as a body.

  • POST with a --form file= command:

curl --request POST --header "Host: %1:8080" --header "Connection: Keep-Alive" --form file=@httpPostSample.xml http://%1:8080/target

This will automatically ad a Content-Length: xxx header (way longer than 245) because it converts the request into a Content-Type: multipart/form-data; boundary=------------------------e1c0d47bac806954 one (the hex at the end differs) which is totally unlike what Postman does.

It is also unlike to what the HTTP server accepts.

curl --request POST --header "Host: %1:8080" --header "Connection: Keep-Alive" --data-binary @httpPostSample.xml http://%1:8080/target

curl –request POST –header “Host: %1:8080” –header “Connection: Keep-Alive” –data-binary @httpPostSample.xml http://%1:8080/target

It turns out that --data-ascii is exactly the same as --data and that --data-binary just skips some new-line conversion when compared to --data or --data-ascii. Contrary to the --data-raw documentation that suggest it is equivalent to --data-binary it seems --data-raw behaves exactly like --data and --data-ascii. Odd.

So these are all stuck with the Content-Type: application/x-www-form-urlencoded and I thought I was running out of options.

Then I found [WayBacksoundmonster had posted an answer at [WayBackhttp – What is the cURL command-line syntax to do a POST request? – Super User mentioning to add a Content-Type header.

So I changed the request to include the --header "Content-Type: text/xml; charset=UTF-8"  header:

  • curl --request POST --header "Content-Type: text/xml; charset=UTF-8" --header "Host: %1:8080" --header "Connection: Keep-Alive" --data @httpPostSample.xml http://%1:8080/target

This works. But: the Content-Type header is not present in the original request.

Finally it occurred to me: What if cURL would not insert a Content-Type header if I add an empty Content-Type header?.

That works!

  • curl --request POST --header "Content-Type:" --header "Host: %1:8080" --header "Connection: Keep-Alive" --data @httpPostSample.xml http://%1:8080/target

It posts exactly the same content as the IoT devices and Postman do.

Phew!

 

I tried to combine this with the --write-out (a.k.a. -w) option, but for older versions of cURL (I could reproduce with 7.34) that forces cURL back in to Content-Type: application/x-www-form-urlencoded mode so watch your cURL version!

Later I will put more research in chuncked transfer. Links that might help me:

–jeroen

Some of the references:

Posted in *nix, bash, cURL, Development, Power User, Scripting, Software Development | Leave a Comment »

MAC address ranges safe for testing purposes (Locally Administered Address)

Posted by jpluimers on 2017/10/25

Similar to IP ranges for private networks that are safe for testing

  • 10.0.0.0/8 (255.0.0.0)
  • 172.16.0.0/12 (255.240.0.0)
  • 192.168.0.0/16 (255.255.0.0)
  • fd00::/8

there are also locally administered MAC address ranges safe for testing

  • x2:xx:xx:xx:xx:xx
  • x6:xx:xx:xx:xx:xx
  • xA:xx:xx:xx:xx:xx
  • xE:xx:xx:xx:xx:xx

Thanks to [WayBack] Sam and [WayBackPeter for answering.

–jeroen

References:

Posted in Ethernet, Internet, Network-and-equipment, Power User | Leave a Comment »

 
%d bloggers like this: