fix bugs in emscripten socket syscalls

wasmerio · Jun 6, 2019 · 8df63b1 · 8df63b1
1 parent 4913cfa
commit 8df63b1
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Showing 3 changed files with 41 additions and 12 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -6,6 +6,7 @@ Blocks of changes will separated by version increments.
 
 ## **[Unreleased]**
 
+- [#484](https://github.com/wasmerio/wasmer/pull/484) Fix bugs in emscripten socket syscalls
 - [#476](https://github.com/wasmerio/wasmer/pull/476) Fix bug with wasi::environ_get, fix off by one error in wasi::environ_sizes_get
 - [#470](https://github.com/wasmerio/wasmer/pull/470) Add mapdir support to Emscripten, implement getdents for Unix
 - [#467](https://github.com/wasmerio/wasmer/pull/467) `wasmer_instantiate` returns better error messages in the runtime C API

diff --git a/lib/emscripten/src/syscalls/mod.rs b/lib/emscripten/src/syscalls/mod.rs
@@ -425,13 +425,25 @@ pub fn ___syscall146(ctx: &mut Ctx, _which: i32, mut varargs: VarArgs) -> i32 {
 }
 
 pub fn ___syscall168(_ctx: &mut Ctx, _one: i32, _two: i32) -> i32 {
-    debug!("emscripten::___syscall168");
+    debug!("emscripten::___syscall168 - stub");
     -1
 }
 
-pub fn ___syscall191(_ctx: &mut Ctx, _one: i32, _two: i32) -> i32 {
-    debug!("emscripten::___syscall191 - stub");
-    -1
+pub fn ___syscall191(ctx: &mut Ctx, _which: i32, mut varargs: VarArgs) -> i32 {
+    let _resource: i32 = varargs.get(ctx);
+    debug!(
+        "emscripten::___syscall191 - mostly stub, resource: {}",
+        _resource
+    );
+    let rlim_emptr: i32 = varargs.get(ctx);
+    let rlim = emscripten_memory_pointer!(ctx.memory(0), rlim_emptr) as *mut i64;
+
+    // set all to infinity
+    unsafe {
+        *(rlim.add(0)) = -1;
+        *(rlim.add(1)) = -1;
+    }
+    0
 }
 
 pub fn ___syscall199(_ctx: &mut Ctx, _one: i32, _two: i32) -> i32 {
@@ -543,19 +555,23 @@ pub fn ___syscall340(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> c_in
     debug!("emscripten::___syscall340 (prlimit64), {}", _which);
     // NOTE: Doesn't really matter. Wasm modules cannot exceed WASM_PAGE_SIZE anyway.
     let _pid: i32 = varargs.get(ctx);
-    let _resource: i32 = varargs.get(ctx);
+    let resource: i32 = varargs.get(ctx);
     let _new_limit: u32 = varargs.get(ctx);
     let old_limit: u32 = varargs.get(ctx);
 
+    let val = match resource {
+        // RLIMIT_NOFILE
+        7 => 1024,
+        _ => -1, // RLIM_INFINITY
+    };
+
     if old_limit != 0 {
         // just report no limits
         let buf_ptr = emscripten_memory_pointer!(ctx.memory(0), old_limit) as *mut u8;
         let buf = unsafe { slice::from_raw_parts_mut(buf_ptr, 16) };
 
-        LittleEndian::write_i32(&mut buf[..], -1); // RLIM_INFINITY
-        LittleEndian::write_i32(&mut buf[4..], -1); // RLIM_INFINITY
-        LittleEndian::write_i32(&mut buf[8..], -1); // RLIM_INFINITY
-        LittleEndian::write_i32(&mut buf[12..], -1); // RLIM_INFINITY
+        LittleEndian::write_i64(&mut buf[..], val);
+        LittleEndian::write_i64(&mut buf[8..], val);
     }
 
     0

diff --git a/lib/emscripten/src/syscalls/unix.rs b/lib/emscripten/src/syscalls/unix.rs
@@ -610,15 +610,24 @@ pub fn ___syscall102(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> c_in
             // recvfrom (socket: c_int, buf: *const c_void, len: size_t, flags: c_int, addr: *const sockaddr, addrlen: socklen_t) -> ssize_t
             let socket = socket_varargs.get(ctx);
             let buf: u32 = socket_varargs.get(ctx);
-            let flags = socket_varargs.get(ctx);
             let len: i32 = socket_varargs.get(ctx);
+            let flags: i32 = socket_varargs.get(ctx);
             let address: u32 = socket_varargs.get(ctx);
             let address_len: u32 = socket_varargs.get(ctx);
             let buf_addr = emscripten_memory_pointer!(ctx.memory(0), buf) as _;
             let address = emscripten_memory_pointer!(ctx.memory(0), address) as *mut sockaddr;
             let address_len_addr =
                 emscripten_memory_pointer!(ctx.memory(0), address_len) as *mut socklen_t;
-            unsafe { recvfrom(socket, buf_addr, flags, len, address, address_len_addr) as i32 }
+            unsafe {
+                recvfrom(
+                    socket,
+                    buf_addr,
+                    len as usize,
+                    flags,
+                    address,
+                    address_len_addr,
+                ) as i32
+            }
         }
         14 => {
             debug!("socket: setsockopt");
@@ -764,7 +773,10 @@ pub fn ___syscall142(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> c_in
     let exceptfds: u32 = varargs.get(ctx);
     let _timeout: i32 = varargs.get(ctx);
 
-    assert!(nfds <= 64, "`nfds` must be less than or equal to 64");
+    if nfds > 1024 {
+        // EINVAL
+        return -22;
+    }
     assert!(exceptfds == 0, "`exceptfds` is not supporrted");
 
     let readfds_ptr = emscripten_memory_pointer!(ctx.memory(0), readfds) as _;