fs/hostfs: Improve hostfs POSIX compatibility

[LingaoM]

Summary

This PR improves NuttX sim compatibility for standard POSIX-facing APIs used by simulated applications.

Changes included:

• Add AF_LOCAL / AF_UNIX support to sim usrsock, so applications can use the normal NuttX socket API to communicate with host Unix-domain sockets.
• Translate hostfs POSIX byte-range lock operations. fcntl(F_GETLK/F_SETLK/F_SETLKW) reaches file systems as FIOC_* ioctl commands after VFS handling; hostfs now converts those lock requests
  back to host fcntl() for host-backed files.
• Fix hostfs long-root path handling. hostfs now uses the configured NuttX PATH_MAX and preserves the relative path component when the configured host root already consumes most of the path
  buffer.
• Add built-in http and https service entries to libc netdb so getservbyname() / getaddrinfo() can resolve common service names without requiring numeric ports.

The changes keep applications using standard NuttX/POSIX interfaces rather than exposing host-only APIs directly to application code.

Test application reference:

• LingaoM/nuttx-apps@ac8459b

That temporary test app (examples/sim_posix) exercises the affected APIs through normal application-facing interfaces:

• getservbyname() and getaddrinfo() for http / https
• hostfs mount with a long host root path
• hostfs byte-range locks through fcntl(F_GETLK/F_SETLK/F_SETLKW)
• AF_LOCAL sockets through the NuttX socket API and sim usrsock

Impact

• Affects sim builds using usrsock, hostfs, or libc netdb.
• Applications can use socket(AF_LOCAL, ...) through the normal NuttX socket layer on sim when native CONFIG_NET_LOCAL is not enabled.
• Applications using hostfs can use POSIX byte-range file locks through fcntl(F_GETLK/F_SETLK/F_SETLKW).
• F_SETLKW is implemented without forwarding a blocking host F_SETLKW call directly. hostfs retries with non-blocking host F_SETLK and sleeps between retries, avoiding a host-side blocking
  call that could stop the whole sim OS.
• http and https become available in the built-in service database when CONFIG_LIBC_NETDB=y.
• No hardware targets are affected by the sim usrsock host-side changes. hostfs backends that do not support host-side locking return -ENOTTY, allowing the VFS file-lock fallback path to
  handle unsupported cases.

Testing

Host machine:

• Ubuntu 22.04 x86_64

Board/config:

• sim:nsh

apps test application:

• Temporary test app from:
  LingaoM/nuttx-apps@ac8459b

Configuration used in addition to sim:nsh:

CONFIG_FS_HOSTFS=y
CONFIG_LIBC_NETDB=y

CONFIG_NET=y
CONFIG_NET_IPv4=y
CONFIG_NET_SOCKOPTS=y
CONFIG_NET_USRSOCK=y
CONFIG_NET_USRSOCK_TCP=y
CONFIG_SIM_NETUSRSOCK=y

CONFIG_PATH_MAX=512
CONFIG_EXAMPLES_SIM_POSIX=y

# CONFIG_NET_LOCAL is not set

CONFIG_NET_LOCAL was left disabled intentionally so AF_LOCAL sockets are handled by sim usrsock; otherwise native NuttX local sockets can handle AF_LOCAL before the sim usrsock backend is
exercised.

Build:

  ./tools/configure.sh -E -l -a ../nuttx-apps sim:nsh
  make olddefconfig
  make clean
  make -j16

Runtime test:

  seg=xxxxxxxxxxxxxxxxxxxxxxxxxxxx
  root=/tmp/simposix

  for i in $(seq 1 10); do
    root="$root/$seg"
  done

  rm -rf /tmp/simposix
  mkdir -p "$root"

  printf 'sim_posix\npoweroff\n' | ./nuttx

Expected output:

  NuttShell (NSH) NuttX-13.0.0
  nsh> sim_posix
  sim_posix: netdb http/tcp ok
  sim_posix: netdb https/tcp ok
  sim_posix: hostfs locks ok
  sim_posix: hostfs long root ok
  sim_posix: AF_LOCAL usrsock ok
  sim_posix: PASS
  nsh> poweroff

The test verifies:

• getservbyname("http", "tcp") resolves to port 80.
• getservbyname("https", "tcp") resolves to port 443.
• getaddrinfo(NULL, "http", ...) and getaddrinfo(NULL, "https", ...) resolve service names through libc netdb.
• hostfs can mount a host root path longer than 256 bytes and still create/read a file below the mounted path.
• hostfs handles fcntl(F_GETLK), fcntl(F_SETLK), fcntl(F_SETLKW), and unlock through F_UNLCK.
• socket(AF_LOCAL, SOCK_STREAM, 0) works through sim usrsock, including bind(), listen(), connect(), accept(), getpeername(), poll(), send(), and recv().

[github-actions]

MemBrowse Memory Report

qemu-armv8a

• Code: .text.hostfs_ioctl +20 B, .text.hostfs_mkpath.constprop.0 -12 B (+0.0%, 315,358 B)
  No memory changes detected for:
• arduino-mega2560
• esp32-devkitc
• hifive1-revb
• mirtoo
• qemu-intel64
• rx65n-rsk2mb
• s698pm-dkit
• stm32-nucleo-f103rb

[linguini1]

Can you include the test application code you used?

Also, just a note, the PR title should follow the same format as your commit subject since we use the titles to generate and sort release notes.

You should also included the 'Assisted-by' field in the commit message when using AI tooling.

[xiaoxiang781216]

for (; ; )

[xiaoxiang781216]

revert, let's convert -ENOSYS to -ENOTTY in arch/sim