wasm: Fix build with wasmtime 27.0.0

Wasmtime 27.0.0 adjusted the C API to start flowing through the
directory and file permission bits of the underlying rust
wasi_config_preopen_dir() implementation.

The directory permissions control whether a directory is read-only or
whether you can create/modify files within.

You always need at least WASMTIME_WASI_DIR_PERMS_READ.

The file permissions control whether you can read or read/write files.

WASMTIME_WASI_FILE_PERMS_WRITE seems to imply
WASMTIME_WASI_FILE_PERMS_READ (but we add both just to make it clear
what we want)

[ Permissions tweak and commit message - Andrew ]
Signed-off-by: Andrew Clayton <[email protected]>

src/wasm/nxt_rt_wasmtime.c

@@ -281,7 +281,13 @@ nxt_wasmtime_wasi_init(const nxt_wasm_ctx_t *ctx)
     wasi_config_inherit_stderr(wasi_config);
 
     for (dir = ctx->dirs; dir != NULL && *dir != NULL; dir++) {
+#if defined(WASMTIME_VERSION_MAJOR) && (WASMTIME_VERSION_MAJOR >= 27)
+        wasi_config_preopen_dir(wasi_config, *dir, *dir,
+                WASMTIME_WASI_DIR_PERMS_READ|WASMTIME_WASI_DIR_PERMS_WRITE,
+                WASMTIME_WASI_FILE_PERMS_READ|WASMTIME_WASI_FILE_PERMS_WRITE);
+#else
         wasi_config_preopen_dir(wasi_config, *dir, *dir);
+#endif
     }
 
     error = wasmtime_context_set_wasi(rt_ctx->ctx, wasi_config);