Implement fd_fdstat_get.

Improve other WASI functions as well.

Signed-off-by: Zoltan Herczeg [email protected]

src/wasi/WASI.cpp

@@ -41,14 +41,23 @@ static void* get_memory_pointer(Instance* instance, Value& value, size_t size)
     return memory->buffer() + offset;
 }
 
+template <class T, int maxSize>
 class TemporaryData {
 public:
     TemporaryData(size_t size)
     {
+        /* Check that more memory is requested than the maximum provided by malloc. */
+        if (size > (std::numeric_limits<size_t>::max() / sizeof(T))) {
+            m_data = nullptr;
+            return;
+        }
+
+        size *= sizeof(T);
+
         if (size <= sizeof(m_stackData)) {
             m_data = m_stackData;
         } else {
-            m_data = malloc(size);
+            m_data = reinterpret_cast<T*>(malloc(size));
         }
     }
 
@@ -59,14 +68,14 @@ class TemporaryData {
         }
     }
 
-    void* data()
+    T* data()
     {
         return m_data;
     }
 
 private:
-    void* m_stackData[8];
-    void* m_data;
+    T m_stackData[maxSize];
+    T* m_data;
 };
 
 void WASI::initialize(uvwasi_t* uvwasi)
@@ -123,51 +132,78 @@ void WASI::clock_time_get(ExecutionState& state, Value* argv, Value* result, Ins
 void WASI::fd_write(ExecutionState& state, Value* argv, Value* result, Instance* instance)
 {
     uint32_t fd = argv[0].asI32();
-    uint32_t iovptr = argv[1].asI32();
-    uint32_t iovcnt = argv[2].asI32();
-    uint32_t out = argv[3].asI32();
+    size_t iovsLen = static_cast<size_t>(argv[2].asI32());
+    uint32_t* nwritten = reinterpret_cast<uint32_t*>(get_memory_pointer(instance, argv[3], sizeof(uint32_t)));
+    uint32_t* iovptr = reinterpret_cast<uint32_t*>(get_memory_pointer(instance, argv[1], iovsLen * (sizeof(uint32_t) << 1)));
 
-    if (uint64_t(iovptr) + iovcnt >= instance->memory(0)->sizeInByte()) {
-        result[0] = Value(static_cast<int16_t>(WasiErrNo::inval));
+    if (iovptr == nullptr || nwritten == nullptr) {
+        result[0] = Value(WasiErrNo::inval);
         return;
     }
 
-    std::vector<uvwasi_ciovec_t> iovs(iovcnt);
-    for (uint32_t i = 0; i < iovcnt; i++) {
-        iovs[i].buf = instance->memory(0)->buffer() + *reinterpret_cast<uint32_t*>(instance->memory(0)->buffer() + iovptr + i * 8);
-        iovs[i].buf_len = *reinterpret_cast<uint32_t*>(instance->memory(0)->buffer() + iovptr + 4 + i * 8);
-    }
+    TemporaryData<uvwasi_ciovec_t, 8> iovsBuffer(iovsLen);
+    uvwasi_ciovec_t* iovs = iovsBuffer.data();
+    uint64_t sizeInByte = instance->memory(0)->sizeInByte();
+    uint8_t* buffer = instance->memory(0)->buffer();
 
-    uvwasi_size_t* out_addr = (uvwasi_size_t*)(instance->memory(0)->buffer() + out);
+    for (uint32_t i = 0; i < iovsLen; i++) {
+        if (iovptr[1] > sizeInByte || iovptr[0] > sizeInByte - iovptr[1]) {
+            result[0] = Value(WasiErrNo::inval);
+            return;
+        }
+
+        iovs[i].buf = buffer + iovptr[0];
+        iovs[i].buf_len = iovptr[1];
+        iovptr += 2;
+    }
 
-    result[0] = Value(static_cast<int16_t>(uvwasi_fd_write(WASI::g_uvwasi, fd, iovs.data(), iovs.size(), out_addr)));
-    *(instance->memory(0)->buffer() + out) = *out_addr;
+    result[0] = Value(uvwasi_fd_write(WASI::g_uvwasi, fd, iovs, iovsLen, nwritten));
 }
 
 void WASI::fd_read(ExecutionState& state, Value* argv, Value* result, Instance* instance)
 {
     uint32_t fd = argv[0].asI32();
-    uint32_t iovptr = argv[1].asI32();
-    uint32_t iovcnt = argv[2].asI32();
-    uint32_t out = argv[3].asI32();
-
-    std::vector<uvwasi_iovec_t> iovs(iovcnt);
-    for (uint32_t i = 0; i < iovcnt; i++) {
-        iovs[i].buf = instance->memory(0)->buffer() + *reinterpret_cast<uint32_t*>(instance->memory(0)->buffer() + iovptr + i * 8);
-        iovs[i].buf_len = *reinterpret_cast<uint32_t*>(instance->memory(0)->buffer() + iovptr + 4 + i * 8);
+    size_t iovsLen = static_cast<size_t>(argv[2].asI32());
+    uint32_t* nread = reinterpret_cast<uint32_t*>(get_memory_pointer(instance, argv[3], sizeof(uint32_t)));
+    uint32_t* iovptr = reinterpret_cast<uint32_t*>(get_memory_pointer(instance, argv[1], iovsLen * (sizeof(uint32_t) << 1)));
+
+    if (iovptr == nullptr || nread == nullptr) {
+        result[0] = Value(WasiErrNo::inval);
+        return;
     }
 
-    uvwasi_size_t* out_addr = (uvwasi_size_t*)(instance->memory(0)->buffer() + out);
+    TemporaryData<uvwasi_iovec_t, 8> iovsBuffer(iovsLen);
+    uvwasi_iovec_t* iovs = iovsBuffer.data();
+    uint64_t sizeInByte = instance->memory(0)->sizeInByte();
+    uint8_t* buffer = instance->memory(0)->buffer();
+
+    for (uint32_t i = 0; i < iovsLen; i++) {
+        if (iovptr[1] > sizeInByte || iovptr[0] > sizeInByte - iovptr[1]) {
+            result[0] = Value(WasiErrNo::inval);
+            return;
+        }
+
+        iovs[i].buf = buffer + iovptr[0];
+        iovs[i].buf_len = iovptr[1];
+        iovptr += 2;
+    }
 
-    result[0] = Value(static_cast<int16_t>(uvwasi_fd_read(WASI::g_uvwasi, fd, iovs.data(), iovs.size(), out_addr)));
-    *(instance->memory(0)->buffer() + out) = *out_addr;
+    result[0] = Value(uvwasi_fd_read(WASI::g_uvwasi, fd, iovs, iovsLen, nread));
 }
 
 void WASI::fd_close(ExecutionState& state, Value* argv, Value* result, Instance* instance)
 {
     uint32_t fd = argv[0].asI32();
 
-    result[0] = Value(static_cast<int16_t>(uvwasi_fd_close(WASI::g_uvwasi, fd)));
+    result[0] = Value(uvwasi_fd_close(WASI::g_uvwasi, fd));
+}
+
+void WASI::fd_fdstat_get(ExecutionState& state, Value* argv, Value* result, Instance* instance)
+{
+    uint32_t fd = argv[0].asI32();
+    uvwasi_fdstat_t* fdstat = reinterpret_cast<uvwasi_fdstat_t*>(get_memory_pointer(instance, argv[1], sizeof(uvwasi_fdstat_t)));
+
+    result[0] = Value(uvwasi_fd_fdstat_get(WASI::g_uvwasi, fd, fdstat));
 }
 
 void WASI::fd_seek(ExecutionState& state, Value* argv, Value* result, Instance* instance)
@@ -218,7 +254,7 @@ void WASI::environ_get(ExecutionState& state, Value* argv, Value* result, Instan
         return;
     }
 
-    TemporaryData pointers(count * sizeof(void*));
+    TemporaryData<void*, 8> pointers(count);
 
     if (pointers.data() == nullptr) {
         result[0] = Value(WasiErrNo::inval);

src/wasi/WASI.h

@@ -44,6 +44,7 @@ class WASI {
     F(fd_write, I32I32I32I32_RI32)                 \
     F(fd_read, I32I32I32I32_RI32)                  \
     F(fd_close, I32_RI32)                          \
+    F(fd_fdstat_get, I32I32_RI32)                  \
     F(fd_seek, I32I64I32I32_RI32)                  \
     F(path_open, I32I32I32I32I32I64I64I32I32_RI32) \
     F(environ_get, I32I32_RI32)                    \
@@ -159,6 +160,7 @@ class WASI {
     static void fd_write(ExecutionState& state, Value* argv, Value* result, Instance* instance);
     static void fd_read(ExecutionState& state, Value* argv, Value* result, Instance* instance);
     static void fd_close(ExecutionState& state, Value* argv, Value* result, Instance* instance);
+    static void fd_fdstat_get(ExecutionState& state, Value* argv, Value* result, Instance* instance);
     static void fd_seek(ExecutionState& state, Value* argv, Value* result, Instance* instance);
     static void path_open(ExecutionState& state, Value* argv, Value* result, Instance* instance);
     static void environ_get(ExecutionState& state, Value* argv, Value* result, Instance* instance);

test/wasi/fd_fdstat_get.wast

@@ -0,0 +1,60 @@
+(module
+  (import "wasi_snapshot_preview1" "path_open" (func $path_open (param i32 i32 i32 i32 i32 i64 i64 i32 i32) (result i32)))
+  (import "wasi_snapshot_preview1" "fd_close" (func $fd_close (param i32) (result i32)))
+  (import "wasi_snapshot_preview1" "fd_fdstat_get" (func $fd_fdstat_get (param i32 i32) (result i32)))
+
+  (memory 1 1)
+  (data (i32.const 100) "./fd_fdstat_get.wast")
+
+  (func (export "fdstatGet") (result i32 i32 i32)
+    i32.const 3 ;; Directory file descriptior, by default 3 is the first opened directory
+    i32.const 1 ;; uvwasi_lookupflags_t: UVWASI_LOOKUP_SYMLINK_FOLLOW
+    i32.const 100 ;; Offset of file name in memory
+    i32.const 20 ;; Length of file name
+    i32.const 0 ;; uvwasi_oflags_t: none
+    i64.const 0x42000 ;; base uvwasi_rights_t: UVWASI_RIGHT_PATH_OPEN, UVWASI_RIGHT_FD_FILESTAT_GET
+    i64.const 0x42000 ;; inherited uvwasi_rights_t: UVWASI_RIGHT_PATH_OPEN, UVWASI_RIGHT_FD_FILESTAT_GET
+    i32.const 0 ;; uvwasi_fdflags_t: none
+    i32.const 0 ;; Offset to store at the opened file descriptor in memory
+    call $path_open
+
+    i32.const 0
+    i32.load
+    i32.const 200
+    call $fd_fdstat_get
+
+    i32.const 0
+    i32.load
+    call $fd_close
+  )
+
+  (func (export "fdstatGetBad") (result i32 i32 i32 i32)
+    i32.const 3 ;; Directory file descriptior, by default 3 is the first opened directory
+    i32.const 1 ;; uvwasi_lookupflags_t: UVWASI_LOOKUP_SYMLINK_FOLLOW
+    i32.const 100 ;; Offset of file name in memory
+    i32.const 20 ;; Length of file name
+    i32.const 0 ;; uvwasi_oflags_t: none
+    i64.const 0x42000 ;; base uvwasi_rights_t: UVWASI_RIGHT_PATH_OPEN, UVWASI_RIGHT_FD_FILESTAT_GET
+    i64.const 0x42000 ;; inherited uvwasi_rights_t: UVWASI_RIGHT_PATH_OPEN, UVWASI_RIGHT_FD_FILESTAT_GET
+    i32.const 0 ;; uvwasi_fdflags_t: none
+    i32.const 0 ;; Offset to store at the opened file descriptor in memory
+    call $path_open
+
+    i32.const 0
+    i32.load
+    i32.const 65535
+    call $fd_fdstat_get
+
+    i32.const -1
+    i32.const 200
+    call $fd_fdstat_get
+
+    i32.const 0
+    i32.load
+    call $fd_close
+  )
+)
+
+(assert_return (invoke "fdstatGet") (i32.const 0) (i32.const 0) (i32.const 0))
+(assert_return (invoke "fdstatGetBad") (i32.const 0) (i32.const 28) (i32.const 8) (i32.const 0))
+

test/wasi/print.wast

@@ -0,0 +1,69 @@
+(module
+    (import "wasi_snapshot_preview1" "fd_write" (func $fd_write (param i32 i32 i32 i32) (result i32)))
+
+    (memory $memory 1 1)
+    (data (i32.const 100) "Hello ")
+    (data (i32.const 200) "World!\n")
+
+    (func (export "writeToStdout") (result i32 i32)
+      ;; Write iovs into memory from offset 16
+      i32.const 16
+      i32.const 100
+      i32.store
+
+      i32.const 20
+      i32.const 6
+      i32.store
+
+      i32.const 24
+      i32.const 200
+      i32.store
+
+      i32.const 28
+      i32.const 7
+      i32.store
+
+      i32.const 1 ;; stdout
+      i32.const 16 ;; iovs offset
+      i32.const 2 ;; iovsLen
+      i32.const 8 ;; nwritten
+
+      call $fd_write
+
+      i32.const 8
+      i32.load
+    )
+
+    (func (export "badWrite") (result i32 i32 i32 i32)
+      i32.const 100000 ;; invalid descriptor
+      i32.const 8 ;; iovs offset
+      i32.const 1 ;; iovsLen
+      i32.const 4 ;; nwritten
+
+      call $fd_write
+
+      i32.const 1 ;; stdout
+      i32.const 65529 ;; bad iovs offset
+      i32.const 1 ;; iovsLen
+      i32.const 8 ;; nwritten
+
+      call $fd_write
+
+      i32.const 1 ;; stdout
+      i32.const 16 ;; iovs offset
+      i32.const 1 ;; iovsLen
+      i32.const 65533 ;; bad nwritten
+
+      call $fd_write
+
+      i32.const 1 ;; stdout
+      i32.const 8 ;; iovs offset
+      i32.const 8192 ;; bad iovsLen
+      i32.const 0 ;; nwritten
+
+      call $fd_write
+    )
+)
+
+(assert_return (invoke "writeToStdout") (i32.const 0) (i32.const 13))
+(assert_return (invoke "badWrite") (i32.const 8) (i32.const 28) (i32.const 28) (i32.const 28))