Implement sock_addr_local syscall

[loganek]

I also slightly changed the interface - since we already have a __wasi_addr_t
structure which is an union, there's no need for passing length around - the
address buffer will always have the right length (i.e. max of all address
families).

[lum1n0us]

only some code-style problems

[loganek]

only some code-style problems

Thanks, already replied.

[wenyongh]

@loganek There are compilation errors on linux-sgx platform:

usr/bin/ld: libvmlib.a(posix.c.o): in function `wasi_ssp_sock_addr_local':
posix.c:(.text.wasi_ssp_sock_addr_local+0x157): undefined reference to `ntohl'
/usr/bin/ld: libvmlib.a(posix.c.o): in function `wasi_ssp_sock_addr_resolve':
posix.c:(.text.wasi_ssp_sock_addr_resolve+0x151): undefined reference to `ntohl'

These functions are not provided by sgx-sdk, but they were implemented in linux-sgx sgx_socket.c as static functions:
https://github.com/bytecodealliance/wasm-micro-runtime/blob/main/core/shared/platform/linux-sgx/sgx_socket.c#L65-L130

Could you please add the API declarations in core/shared/platform/linux-sgx/platform_internal.h, and move the implementation into core/shared/platform/linux-sgx/platform_init.c and remove static flag?

[loganek]

@loganek There are compilation errors on linux-sgx platform:

usr/bin/ld: libvmlib.a(posix.c.o): in function `wasi_ssp_sock_addr_local':
posix.c:(.text.wasi_ssp_sock_addr_local+0x157): undefined reference to `ntohl'
/usr/bin/ld: libvmlib.a(posix.c.o): in function `wasi_ssp_sock_addr_resolve':
posix.c:(.text.wasi_ssp_sock_addr_resolve+0x151): undefined reference to `ntohl'

These functions are not provided by sgx-sdk, but they were implemented in linux-sgx sgx_socket.c as static functions: https://github.com/bytecodealliance/wasm-micro-runtime/blob/main/core/shared/platform/linux-sgx/sgx_socket.c#L65-L130

Could you please add the API declarations in core/shared/platform/linux-sgx/platform_internal.h, and move the implementation into core/shared/platform/linux-sgx/platform_init.c and remove static flag?

Hi @wenyongh , I've kept the implementation in sgx_socket.c but made it non-static. Is there any reason we'd prefer to move it to platform_init.c? What's the purpose of that file? I think similar functions follow the same pattern (i.e. the implementation exists in sgx_socket file).

Regarding the header file - I added the declaration to sgx_socket.h, as it looked like other functions are declared there, and the file is already included through other headers.

[wenyongh]

Hi @wenyongh , I've kept the implementation in sgx_socket.c but made it non-static. Is there any reason we'd prefer to move it to platform_init.c? What's the purpose of that file? I think similar functions follow the same pattern (i.e. the implementation exists in sgx_socket file).

Regarding the header file - I added the declaration to sgx_socket.h, as it looked like other functions are declared there, and the file is already included through other headers.

@loganek It should be also OK, platform_init.c is to implement some common APIs for the platform, here it should be sgx_platform.c, for linux/windows/darwin, we named it platform_init.c. I will review the code again and merge it if there is no issue found.