wpcap.so: cannot open on linux build

[TechnoChimp]

Tested on both Ubuntu 18.04 and Ubuntu 22.04. Both with dotnet7.

.csproj

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net7.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
    <PublishAot>true</PublishAot>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="SharpPcap" Version="6.2.5" />
    ...
  </ItemGroup>

</Project>

Build command: dotnet publish -r linux-amd64 -c Release

Full output when running the generated executable:

Unhandled Exception: System.DllNotFoundException: Unable to load shared library 'wpcap' or one of its dependencies. In order to help diagnose loading problems, consider using a tool like strace. If you're using glibc, consider setting the LD_DEBUG environment variable:
wpcap.so: cannot open shared object file: No such file or directory
libwpcap.so: cannot open shared object file: No such file or directory
wpcap: cannot open shared object file: No such file or directory
libwpcap: cannot open shared object file: No such file or directory

   at System.Runtime.InteropServices.NativeLibrary.LoadLibErrorTracker.Throw(String) + 0x4e
   at Internal.Runtime.CompilerHelpers.InteropHelpers.FixupModuleCell(InteropHelpers.ModuleFixupCell*) + 0x10f
   at Internal.Runtime.CompilerHelpers.InteropHelpers.ResolvePInvokeSlow(InteropHelpers.MethodFixupCell*) + 0x35
   at SharpPcap.LibPcap.LibPcapSafeNativeMethods.pcap_findalldevs(IntPtr&, StringBuilder) + 0x6f
   at SharpPcap.LibPcap.PcapInterface.GetAllPcapInterfaces() + 0x40
   at SharpPcap.LibPcap.LibPcapLiveDeviceList.GetDevices() + 0x32
   at SharpPcap.LibPcap.LibPcapLiveDeviceList.Refresh() + 0x2b
   at SharpPcap.LibPcap.LibPcapLiveDeviceList.get_Instance() + 0x2a
   at <redacted>.Program.<Main>d__0.MoveNext() + 0x2e
--- End of stack trace from previous location ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() + 0x1c
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task) + 0xc2
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task) + 0x44
   at <redacted>.Program.<Main>(String[]) + 0x20
   at <redacted>!<BaseAddress>+0xd9e0ab
Aborted (core dumped)

[kayoub5]

what libpcap version did you install?

[TechnoChimp]

I installed the latest libpcap-dev from apt. This version seems to be fine. If I link the libpcap.so file as libwpcap.so then it does work, but based on old closed issues that shouldn't be needed since that issue was resolved.

[kayoub5]

the solution implemented for dynamic detection of pcap library, is not compatible with PublishAot

[TechnoChimp]

Ah ok, that did seem to be my problem. Removing Aot I can now run the executable on a machine as long as libpcap-dev is installed on that machine. (If libpcap-dev is not installed I still get the error regarding libwpcap missing which threw me off for a second there.)

Regarding the libpcap-dev dependency, I don't suppose there's a way to bundle this into the build package so it doesn't need to be installed alongside my generated executable?

[kayoub5]

sharppcap lools for a libpcap.so, whether you can bundle that or not (and it keeps working across systems), is a question for the libpcap maintainers, there is no definitive answer here.