MacOS 104 path length limit. Invalid length for use with domain sockets on this platform. The length must be between 1 and 104

[ep1kt3t0s]

Description

On MacOS (13.0.1, Apple Silicon) with dotnet 6.0.403 and 6.0.400 I got the below issue with paths being restricted to 104 characters.
I do think MacOS allows paths longer than 104, so I'm not sure where the 104 is coming.
I found this below code snippet that which I believe sets the 104 character limit but I could not run it on my dev environment.
Interop.Sys.GetDomainSocketSizes(out s_nativePathOffset, out s_nativePathLength, out s_nativeAddressSize);

But I am also using Path.GetTempPath() to get a work directory which produces a path like /var/folders/7b/tkffkjy54676nvv44rpvv1l40000gn/T/, which is quite long already.

The rest of the socket pipe, coming from using ffmpeg but I don't think related to it, creates a path of CoreFxPipe_FFMpegCore_782288f0-1e42-4550-ab59-5a5161581e5b and combination of these exceed 104 characters.

I do believe something might be wrong on MacOS with 104 character limit and might be better to check it out.

System.ArgumentOutOfRangeException: The path '/var/folders/7b/tkffkjy54676nvv44rpvv1l40000gn/T/CoreFxPipe_FFMpegCore_782288f0-1e42-4550-ab59-5a5161581e5b' is of an invalid length for use with domain sockets on this platform.  The length must be between 1 and 104 characters, inclusive. (Parameter 'path')
      Actual value was /var/folders/7b/tkffkjy54676nvv44rpvv1l40000gn/T/CoreFxPipe_FFMpegCore_782288f0-1e42-4550-ab59-5a5161581e5b.
         at System.Net.Sockets.UnixDomainSocketEndPoint..ctor(String path, String boundFileName)
         at System.Net.Sockets.UnixDomainSocketEndPoint..ctor(String path)
         at System.IO.Pipes.NamedPipeServerStream.SharedServer..ctor(String path, Int32 maxCount)
         at System.IO.Pipes.NamedPipeServerStream.SharedServer.Get(String path, Int32 maxCount)
         at System.IO.Pipes.NamedPipeServerStream.Create(String pipeName, PipeDirection direction, Int32 maxNumberOfServerInstances, PipeTransmissionMode transmissionMode, PipeOptions options, Int32 inBufferSize, Int32 outBufferSize, HandleInheritability inheritability)
         at System.IO.Pipes.NamedPipeServerStream..ctor(String pipeName, PipeDirection direction, Int32 maxNumberOfServerInstances, PipeTransmissionMode transmissionMode, PipeOptions options)

Reproduction Steps

Create a named pipe from a socket within the directory Path.GetTempPath().

Expected behavior

Should not error for 104 character limit on MacOS.

Actual behavior

Errors for 104 character limit on MacOS.

Regression?

No response

Known Workarounds

No response

Configuration

No response

Other information

No response

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Issue Details

---

Description

On MacOS (13.0.1, Apple Silicon) with dotnet 6.0.403 and 6.0.400 I got the below issue with paths being restricted to 104 characters.
I do think MacOS allows paths longer than 104, so I'm not sure where the 104 is coming.

But I am also using Path.GetTempPath() to get a work directory which produces a path like /var/folders/7b/tkffkjy54676nvv44rpvv1l40000gn/T/, which is quite long already.

The rest of the socket pipe, coming from using ffmpeg but I don't think related to it, creates a path of CoreFxPipe_FFMpegCore_782288f0-1e42-4550-ab59-5a5161581e5b and combination of these exceed 104 characters.

I do believe something might be wrong on MacOS with 104 character limit and might be better to check it out.

System.ArgumentOutOfRangeException: The path '/var/folders/7b/tkffkjy54676nvv44rpvv1l40000gn/T/CoreFxPipe_FFMpegCore_782288f0-1e42-4550-ab59-5a5161581e5b' is of an invalid length for use with domain sockets on this platform.  The length must be between 1 and 104 characters, inclusive. (Parameter 'path')
      Actual value was /var/folders/7b/tkffkjy54676nvv44rpvv1l40000gn/T/CoreFxPipe_FFMpegCore_782288f0-1e42-4550-ab59-5a5161581e5b.
         at System.Net.Sockets.UnixDomainSocketEndPoint..ctor(String path, String boundFileName)
         at System.Net.Sockets.UnixDomainSocketEndPoint..ctor(String path)
         at System.IO.Pipes.NamedPipeServerStream.SharedServer..ctor(String path, Int32 maxCount)
         at System.IO.Pipes.NamedPipeServerStream.SharedServer.Get(String path, Int32 maxCount)
         at System.IO.Pipes.NamedPipeServerStream.Create(String pipeName, PipeDirection direction, Int32 maxNumberOfServerInstances, PipeTransmissionMode transmissionMode, PipeOptions options, Int32 inBufferSize, Int32 outBufferSize, HandleInheritability inheritability)
         at System.IO.Pipes.NamedPipeServerStream..ctor(String pipeName, PipeDirection direction, Int32 maxNumberOfServerInstances, PipeTransmissionMode transmissionMode, PipeOptions options)

Reproduction Steps

Create a named pipe from a socket within the directory Path.GetTempPath().

Expected behavior

Should not error for 104 character limit on MacOS.

Actual behavior

Errors for 104 character limit on MacOS.

Regression?

No response

Known Workarounds

No response

Configuration

No response

Other information

No response

Author:	ep1kt3t0s
Assignees:	-
Labels:	area-System.IO
Milestone:	-

[stephentoub]

https://man.openbsd.org/unix.4

"UNIX-domain addresses are variable-length filesystem pathnames of at most 104 characters."

We don't hardcode the length. It comes directly from the os:

runtime/src/native/libs/System.Native/pal_networking.c

Line 3093 in 3689fbe

*pathSize = sizeof(domainSocket.sun_path);

[ep1kt3t0s]

Surprising the limit is only 104 characters. I actually did not hit this limit on Ubuntu but hitting it on MacOS.

[stephentoub]

On Linux the limit is typically 108 and the default temp path is usually much shorter.

[ep1kt3t0s]

Thank you for the clarification @stephentoub