[browser] no sockets

[pavelsavara]

Continuation from #123962 (comment)
Contributes to #122506

Browser variant of

• System.Net.Sockets now throw PNSE for all members.
• SocketAddressPal.Browser.cs doesn't talk to posix and it's shallow similar to SocketAddressPal.Windows.cs

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[Copilot]

Pull request overview

This PR advances the browser-WASM “no sockets” effort by making networking/socket-related components consistently unavailable on the browser target, aligning with the broader PAL cleanup work.

Changes:

• Add browser-specific System.Native stubs for networking, interface addresses, and network statistics.
• Switch browser builds away from syscall-trimming JS hacks and toward native/CMake-based stubbing/linking behavior.
• Add a -browser TFM for System.Net.Sockets that builds as a PlatformNotSupported assembly.

Reviewed changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
src/native/libs/System.Native/pal_networkstatistics_wasm.c	Adds WASM/browser stub implementations for network statistics APIs.
src/native/libs/System.Native/pal_networking_browser.c	Adds browser stub implementations for System.Native networking/socket entrypoints.
src/native/libs/System.Native/pal_interfaceaddresses_browser.c	Adds browser stub implementations for interface/gateway enumeration.
src/native/libs/System.Native/CMakeLists.txt	Selects browser-specific PAL sources for System.Native.
src/native/eventpipe/ds-ipc-pal-websocket.c	Adds missing runtime helpers for standalone PAL websocket IPC path.
src/native/corehost/browserhost/libBrowserHost.footer.js	Removes syscall override hooks previously used to “trim” sockets.
src/mono/mono/profiler/log.c	Gates socket header inclusion on configure-time header availability.
src/mono/mono/profiler/helper.c	Gates socket-related includes on configure-time header availability.
src/mono/mono/profiler/aot.c	Gates socket header inclusion on configure-time header availability.
src/mono/mono/mini/cfgdump.c	Gates socket header inclusion on configure-time header availability.
src/libraries/System.Net.Sockets/src/System.Net.Sockets.csproj	Adds -browser TFM and marks it as PlatformNotSupported.
eng/native/tryrun.browser.cmake	Disables HAVE_SYS_SOCKET_H for browser to avoid emscripten socket emulation.
eng/native/configureplatform.cmake	Adds browser CoreCLR link options (-nostdlib + explicit libs).

[Copilot]

Pull request overview

Copilot reviewed 13 out of 13 changed files in this pull request and generated 4 comments.

[Copilot]

Pull request overview

Copilot reviewed 15 out of 15 changed files in this pull request and generated 4 comments.

[jkotas]

LGTM

It would be nice if folks with more detailed understanding of networking and/or wasm signoff as well.

[radekdoulik]

Thank you, LGTM

I wonder if we should document the unsupported parts somewhere. @lewing what did we do on mono in such cases?

[radekdoulik]

nm, we have https://github.com/dotnet/runtime/blob/main/src/mono/wasm/features.md for mono.

I have asked copilot to open draft with similar document for coreclr here #124455

[liveans]

LGTM, just one concern

[Copilot]

Pull request overview

Copilot reviewed 18 out of 18 changed files in this pull request and generated 1 comment.

Comments suppressed due to low confidence (1)

src/mono/mono/mini/cfgdump.c:26

• The include of sys/socket.h is now guarded by HAVE_SYS_SOCKET_H, but netinet/in.h (line 20) and arpa/inet.h (line 26) are still included unconditionally. These headers also won't be available on browser target where HAVE_SYS_SOCKET_H is unset. These includes and the socket-related code that uses them should also be guarded with HAVE_SYS_SOCKET_H or a similar check.

#include <netinet/in.h>
#include <netdb.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <arpa/inet.h>

[pavelsavara]

/ba-g unrelated CI failures