First commitfirst-step

14 files changed, 1154 insertions, 0 deletions

diff --git a/src/section/CMakeLists.txt b/src/section/CMakeLists.txt
new file mode 100644
index 0000000..62d9cef
--- /dev/null
+++ b/src/section/CMakeLists.txt
@@ -0,0 +1,15 @@
+target_sources(${PROJECT_NAME} PRIVATE
+    code.c
+    common.c
+    custom.c
+    data.c
+    element.c
+    export.c
+    function.c
+    global.c
+    import.c
+    memory.c
+    start.c
+    table.c
+    type.c
+)
diff --git a/src/section/code.c b/src/section/code.c
new file mode 100644
index 0000000..6e131e7
--- /dev/null
+++ b/src/section/code.c
@@ -0,0 +1,235 @@
+#include <opcodes.h>
+#include <interp.h>
+#include <sections.h>
+#include <wasm_types.h>
+#include <errno.h>
+#include <inttypes.h>
+#include <stdint.h>
+#include <string.h>
+
+static int check_body(FILE *const f, const unsigned long n)
+{
+    unsigned long rem = n;
+
+    while (rem)
+    {
+        const long before = ftell(f);
+        uint8_t byte;
+
+        if (before < 0)
+        {
+            fprintf(stderr, "%s: ftell(3) before: %s\n", __func__,
+                strerror(errno));
+            return -1;
+        }
+        else if (!fread(&byte, sizeof byte, 1, f))
+        {
+            fprintf(stderr, "%s: fread(3) failed, feof=%d, ferror=%d\n",
+                __func__, feof(f), ferror(f));
+            return -1;
+        }
+        else if (rem == 1 && byte != OP_END)
+        {
+            fprintf(stderr, "%s: unexpected opcode %#" PRIx8 " at body end\n",
+                __func__, byte);
+            return -1;
+        }
+        else if (interp_check_opcode(byte, f))
+        {
+            fprintf(stderr, "%s: interp_check_opcode failed\n", __func__);
+            return -1;
+        }
+
+        const long after = ftell(f);
+
+        if (after < 0)
+        {
+            fprintf(stderr, "%s: ftell(3) after: %s\n", __func__,
+                strerror(errno));
+            return -1;
+        }
+
+        rem -= after - before;
+    }
+
+    return 0;
+}
+
+static int check_type(FILE *const f)
+{
+    varint7 type;
+
+    if (varint7_read(f, &type))
+    {
+        fprintf(stderr, "%s: varint7_read failed\n", __func__);
+        return -1;
+    }
+
+    return 0;
+}
+
+static int check_local(FILE *const f)
+{
+    varuint32 count;
+
+    if (varuint32_read(f, &count))
+    {
+        fprintf(stderr, "%s: varuint32_read failed\n", __func__);
+        return -1;
+    }
+    else if (check_type(f))
+    {
+        fprintf(stderr, "%s: check_type failed\n", __func__);
+        return -1;
+    }
+
+    return 0;
+}
+
+static int check_locals(FILE *const f)
+{
+    varuint32 local_count;
+
+    if (varuint32_read(f, &local_count))
+    {
+        fprintf(stderr, "%s: varuint32_read local_count failed\n", __func__);
+        return -1;
+    }
+
+    for (varuint32 i = 0; i < local_count; i++)
+        if (check_local(f))
+        {
+            fprintf(stderr, "%s: check_local failed\n", __func__);
+            return -1;
+        }
+
+    return 0;
+}
+
+static int check_function_body(FILE *const f)
+{
+    varuint32 body_size;
+
+    if (varuint32_read(f, &body_size))
+    {
+        fprintf(stderr, "%s: varuint32_read body_size failed\n", __func__);
+        return -1;
+    }
+
+    const long start = ftell(f);
+
+    if (start < 0)
+    {
+        fprintf(stderr, "%s: ftell(3) start: %s\n", __func__, strerror(errno));
+        return -1;
+    }
+    else if (check_locals(f))
+    {
+        fprintf(stderr, "%s: check_locals failed\n", __func__);
+        return -1;
+    }
+
+    const long end = ftell(f);
+
+    if (end < 0)
+    {
+        fprintf(stderr, "%s: ftell(3) end: %s\n", __func__, strerror(errno));
+        return -1;
+    }
+
+    const unsigned long consumed = end - start;
+
+    if (consumed > body_size)
+    {
+        fprintf(stderr, "%s: exceeded function body size\n", __func__);
+        return -1;
+    }
+    else if (check_body(f, body_size - consumed))
+    {
+        fprintf(stderr, "%s: check_body failed\n", __func__);
+        return -1;
+    }
+
+    return 0;
+}
+
+static int check_function_bodies(FILE *const f)
+{
+    varuint32 count;
+
+    if (varuint32_read(f, &count))
+    {
+        fprintf(stderr, "%s: varuint32_read failed\n", __func__);
+        return -1;
+    }
+
+    for (varuint32 i = 0; i < count; i++)
+        if (check_function_body(f))
+        {
+            fprintf(stderr, "%s: check_function_body failed\n", __func__);
+            return -1;
+        }
+
+    return 0;
+}
+
+static int check(FILE *const f, const unsigned long len)
+{
+    const long start = ftell(f);
+
+    if (start < 0)
+    {
+        fprintf(stderr, "%s: ftell(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+    else if (check_function_bodies(f))
+    {
+        fprintf(stderr, "%s: check_function_bodies failed\n", __func__);
+        return -1;
+    }
+
+    const long end = ftell(f);
+
+    if (end < 0)
+    {
+        fprintf(stderr, "%s: ftell(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+
+    const unsigned long size = end - start;
+
+    if (size != len)
+    {
+        fprintf(stderr, "%s: size exceeded (%lu expected, got %lu)\n",
+                __func__, len, size);
+        return -1;
+    }
+
+    return 0;
+}
+
+int section_code(struct wasmfs *const w, FILE *const f,
+    const unsigned long len)
+{
+    if (w->sections.code)
+    {
+        fprintf(stderr, "%s: ignoring duplicate section\n", __func__);
+        return 0;
+    }
+
+    const long offset = ftell(f);
+
+    if (offset < 0)
+    {
+        fprintf(stderr, "%s: ftell(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+    else if (check(f, len))
+    {
+        fprintf(stderr, "%s: check failed\n", __func__);
+        return -1;
+    }
+
+    w->sections.code = offset;
+    return 0;
+}
diff --git a/src/section/common.c b/src/section/common.c
new file mode 100644
index 0000000..58ddddb
--- /dev/null
+++ b/src/section/common.c
@@ -0,0 +1,35 @@
+#include <sections.h>
+#include <wasm_types.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+
+int check_resizable_limits(FILE *const f)
+{
+    varuint1 flags;
+    varuint32 initial;
+
+    if (varuint1_read(f, &flags))
+    {
+        fprintf(stderr, "%s: varuint1_read failed\n", __func__);
+        return -1;
+    }
+    else if (varuint32_read(f, &initial))
+    {
+        fprintf(stderr, "%s: varuint32_read failed\n", __func__);
+        return -1;
+    }
+
+    if (flags)
+    {
+        varuint32 maximum;
+
+        if (varuint32_read(f, &maximum))
+        {
+            fprintf(stderr, "%s: varuint32_read failed\n", __func__);
+            return -1;
+        }
+    }
+
+    return 0;
+}
diff --git a/src/section/custom.c b/src/section/custom.c
new file mode 100644
index 0000000..9544f17
--- /dev/null
+++ b/src/section/custom.c
@@ -0,0 +1,17 @@
+#include <sections.h>
+#include <wasm_types.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+
+int section_custom(struct wasmfs *const w, FILE *const f,
+    const unsigned long len)
+{
+    if (fseek(f, len, SEEK_CUR))
+    {
+        fprintf(stderr, "%s: fseek(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+
+    return 0;
+}
diff --git a/src/section/data.c b/src/section/data.c
new file mode 100644
index 0000000..5a04d7b
--- /dev/null
+++ b/src/section/data.c
@@ -0,0 +1,8 @@
+#include <sections.h>
+#include <wasm_types.h>
+
+int section_data(struct wasmfs *const w, FILE *const f,
+    const unsigned long len)
+{
+    return -1;
+}
diff --git a/src/section/element.c b/src/section/element.c
new file mode 100644
index 0000000..370a952
--- /dev/null
+++ b/src/section/element.c
@@ -0,0 +1,8 @@
+#include <sections.h>
+#include <wasm_types.h>
+
+int section_element(struct wasmfs *const w, FILE *const f,
+    const unsigned long len)
+{
+    return -1;
+}
diff --git a/src/section/export.c b/src/section/export.c
new file mode 100644
index 0000000..9ca8de5
--- /dev/null
+++ b/src/section/export.c
@@ -0,0 +1,147 @@
+#include <sections.h>
+#include <wasm_types.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+
+static int check_string(FILE *const f)
+{
+    varuint32 len;
+
+    if (varuint32_read(f, &len))
+    {
+        fprintf(stderr, "%s: varuint32_read failed\n", __func__);
+        return -1;
+    }
+
+    for (varuint32 i = 0; i < len; i++)
+    {
+        uint8_t byte;
+
+        if (!fread(&byte, sizeof byte, 1, f))
+        {
+            fprintf(stderr, "%s: fread(3) failed, feof=%d, ferror=%d\n",
+                __func__, feof(f), ferror(f));
+            return -1;
+        }
+    }
+
+    return 0;
+}
+
+static int check_kind(FILE *const f)
+{
+    varuint32 type;
+
+    if (varuint32_read(f, &type))
+    {
+        fprintf(stderr, "%s: varuint32_read failed\n", __func__);
+        return -1;
+    }
+
+    return 0;
+}
+
+static int check_index(FILE *const f)
+{
+    varuint32 index;
+
+    if (varuint32_read(f, &index))
+    {
+        fprintf(stderr, "%s: varuint32_read failed\n", __func__);
+        return -1;
+    }
+
+    return 0;
+}
+
+static int check_export_entry(FILE *const f)
+{
+    if (check_string(f))
+    {
+        fprintf(stderr, "%s: check_string failed\n", __func__);
+        return -1;
+    }
+    else if (check_kind(f))
+    {
+        fprintf(stderr, "%s: check_kind failed\n", __func__);
+        return -1;
+    }
+    else if (check_index(f))
+    {
+        fprintf(stderr, "%s: check_index failed\n", __func__);
+        return -1;
+    }
+
+    return 0;
+}
+
+static int check(FILE *const f, const unsigned long len)
+{
+    const long start = ftell(f);
+    varuint32 count;
+
+    if (start < 0)
+    {
+        fprintf(stderr, "%s: ftell(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+    else if (varuint32_read(f, &count))
+    {
+        fprintf(stderr, "%s: varuint32_read failed\n", __func__);
+        return -1;
+    }
+
+    for (varuint32 i = 0; i < count; i++)
+        if (check_export_entry(f))
+        {
+            fprintf(stderr, "%s: check_export_entry failed\n", __func__);
+            return -1;
+        }
+
+    const long end = ftell(f);
+
+    if (end < 0)
+    {
+        fprintf(stderr, "%s: ftell(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+
+    const unsigned long size = end - start;
+
+    if (size != len)
+    {
+        fprintf(stderr, "%s: size exceeded (%lu expected, got %lu)\n",
+                __func__, len, size);
+        return -1;
+    }
+
+    return 0;
+}
+
+int section_export(struct wasmfs *const w, FILE *const f,
+    const unsigned long len)
+{
+    if (w->sections.export)
+    {
+        fprintf(stderr, "%s: ignoring duplicate section\n", __func__);
+        return 0;
+    }
+
+    const long offset = ftell(f);
+
+    if (offset < 0)
+    {
+        fprintf(stderr, "%s: ftell(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+    else if (check(f, len))
+    {
+        fprintf(stderr, "%s: check failed\n", __func__);
+        return -1;
+    }
+
+    w->sections.export = offset;
+    return 0;
+}
diff --git a/src/section/function.c b/src/section/function.c
new file mode 100644
index 0000000..f03971c
--- /dev/null
+++ b/src/section/function.c
@@ -0,0 +1,80 @@
+#include <sections.h>
+#include <wasm_types.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+
+static int check(FILE *const f, const unsigned long len)
+{
+    const long start = ftell(f);
+
+    if (start < 0)
+    {
+        fprintf(stderr, "%s: ftell(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+
+    varuint32 count;
+
+    if (varuint32_read(f, &count))
+    {
+        fprintf(stderr, "%s: varuint32_read count failed\n", __func__);
+        return -1;
+    }
+
+    for (varuint32 i = 0; i < count; i++)
+    {
+        varuint32 type;
+
+        if (varuint32_read(f, &type))
+        {
+            fprintf(stderr, "%s: varuint32_read type failed\n", __func__);
+            return -1;
+        }
+    }
+
+    const long end = ftell(f);
+
+    if (end < 0)
+    {
+        fprintf(stderr, "%s: ftell(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+
+    const unsigned long size = end - start;
+
+    if (size != len)
+    {
+        fprintf(stderr, "%s: size exceeded (%lu expected, got %lu)\n",
+                __func__, len, size);
+        return -1;
+    }
+
+    return 0;
+}
+
+int section_function(struct wasmfs *const w, FILE *const f,
+    const unsigned long len)
+{
+    if (w->sections.function)
+    {
+        fprintf(stderr, "%s: ignoring duplicate section\n", __func__);
+        return 0;
+    }
+
+    const long offset = ftell(f);
+
+    if (offset < 0)
+    {
+        fprintf(stderr, "%s: ftell(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+    else if (check(f, len))
+    {
+        fprintf(stderr, "%s: check failed\n", __func__);
+        return -1;
+    }
+
+    w->sections.function = offset;
+    return 0;
+}
diff --git a/src/section/global.c b/src/section/global.c
new file mode 100644
index 0000000..5616e21
--- /dev/null
+++ b/src/section/global.c
@@ -0,0 +1,110 @@
+#include <sections.h>
+#include <interp.h>
+#include <wasm_types.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+
+struct global_type
+{
+    varint7 value_type;
+    varuint1 mutability;
+};
+
+static int check_global_type(FILE *const f, struct global_type *const g)
+{
+    if (varint7_read(f, &g->value_type))
+    {
+        fprintf(stderr, "%s: varint7_read failed\n", __func__);
+        return -1;
+    }
+    else if (varuint1_read(f, &g->mutability))
+    {
+        fprintf(stderr, "%s: varuint1_read failed\n", __func__);
+        return -1;
+    }
+
+    return 0;
+}
+
+static int check(FILE *const f, const unsigned long len)
+{
+    int ret = -1;
+    struct global_type g;
+    struct interp *i = NULL;
+    const long start = ftell(f);
+    const struct interp_cfg cfg =
+    {
+        .f = f
+    };
+
+    if (start < 0)
+    {
+        fprintf(stderr, "%s: ftell(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+    else if (check_global_type(f, &g))
+    {
+        fprintf(stderr, "%s: check_global_type\n", __func__);
+        goto end;
+    }
+    else if (!(i = interp_alloc(&cfg)))
+    {
+        fprintf(stderr, "%s: interp_alloc failed\n", __func__);
+        goto end;
+    }
+    else if (interp_run_limited(i, &interp_initexpr_set))
+    {
+        fprintf(stderr, "%s: interp_run failed\n", __func__);
+        goto end;
+    }
+
+    const long end = ftell(f);
+
+    if (end < 0)
+    {
+        fprintf(stderr, "%s: ftell(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+
+    const unsigned long size = end - start;
+
+    if (size != len)
+    {
+        fprintf(stderr, "%s: size exceeded (%lu expected, got %lu)\n",
+                __func__, len, size);
+        return -1;
+    }
+
+    ret = 0;
+
+end:
+    interp_free(i);
+    return ret;
+}
+
+int section_global(struct wasmfs *const w, FILE *const f,
+    const unsigned long len)
+{
+    if (w->sections.global)
+    {
+        fprintf(stderr, "%s: ignoring duplicate section\n", __func__);
+        return 0;
+    }
+
+    const long offset = ftell(f);
+
+    if (offset < 0)
+    {
+        fprintf(stderr, "%s: ftell(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+    else if (check(f, len))
+    {
+        fprintf(stderr, "%s: check failed\n", __func__);
+        return -1;
+    }
+
+    w->sections.global = offset;
+    return 0;
+}
diff --git a/src/section/import.c b/src/section/import.c
new file mode 100644
index 0000000..06df4e1
--- /dev/null
+++ b/src/section/import.c
@@ -0,0 +1,188 @@
+#include <sections.h>
+#include <wasm_types.h>
+#include <errno.h>
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+
+static int check_string(FILE *const f)
+{
+    varuint32 len;
+
+    if (varuint32_read(f, &len))
+    {
+        fprintf(stderr, "%s: varuint32_read failed\n", __func__);
+        return -1;
+    }
+
+    for (varuint32 i = 0; i < len; i++)
+    {
+        uint8_t byte;
+
+        if (!fread(&byte, sizeof byte, 1, f))
+        {
+            fprintf(stderr, "%s: fread(3) failed, feof=%d, ferror=%d\n",
+                __func__, feof(f), ferror(f));
+            return -1;
+        }
+    }
+
+    return 0;
+}
+
+static int check_function_kind(FILE *const f)
+{
+    varuint32 type;
+
+    if (varuint32_read(f, &type))
+    {
+        fprintf(stderr, "%s: varuint32_read failed\n", __func__);
+        return -1;
+    }
+
+    return 0;
+}
+
+static int check_table_kind(FILE *const f)
+{
+    varint7 type;
+
+    if (varint7_read(f, &type))
+    {
+        fprintf(stderr, "%s: varint7_read failed\n", __func__);
+        return -1;
+    }
+
+    return 0;
+}
+
+static int check_memory_kind(FILE *const f)
+{
+    /* TODO. */
+    return -1;
+}
+
+static int check_global_kind(FILE *const f)
+{
+    /* TODO. */
+    return -1;
+}
+
+static int check_import_entry(FILE *const f)
+{
+    if (check_string(f))
+    {
+        fprintf(stderr, "%s: check_string module failed\n", __func__);
+        return -1;
+    }
+    else if (check_string(f))
+    {
+        fprintf(stderr, "%s: check_string field failed\n", __func__);
+        return -1;
+    }
+
+    uint8_t kind;
+
+    enum
+    {
+        FUNCTION,
+        TABLE,
+        MEMORY,
+        GLOBAL
+    };
+
+    if (!fread(&kind, sizeof kind, 1, f))
+    {
+        fprintf(stderr, "%s: fread(3) failed, feof=%d, ferror=%d\n",
+            __func__, feof(f), ferror(f));
+        return -1;
+    }
+
+    static int (*const fn[])(FILE *) =
+    {
+        [FUNCTION] = check_function_kind,
+        [TABLE] = check_table_kind,
+        [MEMORY] = check_memory_kind,
+        [GLOBAL] = check_global_kind
+    };
+
+    if (kind >= sizeof fn / sizeof *fn)
+    {
+        fprintf(stderr, "%s: unexpected kind %#" PRIx8 "\n", __func__, kind);
+        return -1;
+    }
+
+    return fn[kind](f);
+}
+
+static int check(FILE *const f, const unsigned long len)
+{
+    const long start = ftell(f);
+
+    if (start < 0)
+    {
+        fprintf(stderr, "%s: ftell(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+
+    varuint32 count;
+
+    if (varuint32_read(f, &count))
+    {
+        fprintf(stderr, "%s: varuint32_read failed\n", __func__);
+        return -1;
+    }
+
+    for (varuint32 i = 0; i < count; i++)
+        if (check_import_entry(f))
+        {
+            fprintf(stderr, "%s: check_import_entry failed\n", __func__);
+            return -1;
+        }
+
+    const long end = ftell(f);
+
+    if (end < 0)
+    {
+        fprintf(stderr, "%s: ftell(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+
+    const unsigned long size = end - start;
+
+    if (size != len)
+    {
+        fprintf(stderr, "%s: size exceeded (%lu expected, got %lu)\n",
+                __func__, len, size);
+        return -1;
+    }
+
+    return 0;
+}
+
+int section_import(struct wasmfs *const w, FILE *const f,
+    const unsigned long len)
+{
+    if (w->sections.import)
+    {
+        fprintf(stderr, "%s: ignoring duplicate section\n", __func__);
+        return 0;
+    }
+
+    const long offset = ftell(f);
+
+    if (offset < 0)
+    {
+        fprintf(stderr, "%s: ftell(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+    else if (check(f, len))
+    {
+        fprintf(stderr, "%s: check failed\n", __func__);
+        return -1;
+    }
+
+    w->sections.import = offset;
+    return 0;
+}
diff --git a/src/section/memory.c b/src/section/memory.c
new file mode 100644
index 0000000..aba461a
--- /dev/null
+++ b/src/section/memory.c
@@ -0,0 +1,81 @@
+#include <sections.h>
+#include <wasm_types.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+
+static int check_memory_type(FILE *const f)
+{
+    return check_resizable_limits(f);
+}
+
+static int check(FILE *const f, const unsigned long len)
+{
+    const long start = ftell(f);
+
+    if (start < 0)
+    {
+        fprintf(stderr, "%s: ftell(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+
+    varuint32 count;
+
+    if (varuint32_read(f, &count))
+    {
+        fprintf(stderr, "%s: varuint32_read failed\n", __func__);
+        return -1;
+    }
+
+    for (varuint32 i = 0; i < count; i++)
+        if (check_memory_type(f))
+        {
+            fprintf(stderr, "%s: check_memory_type failed\n", __func__);
+            return -1;
+        }
+
+    const long end = ftell(f);
+
+    if (end < 0)
+    {
+        fprintf(stderr, "%s: ftell(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+
+    const unsigned long size = end - start;
+
+    if (size != len)
+    {
+        fprintf(stderr, "%s: size exceeded (%lu expected, got %lu)\n",
+                __func__, len, size);
+        return -1;
+    }
+
+    return 0;
+}
+
+int section_memory(struct wasmfs *const w, FILE *const f,
+    const unsigned long len)
+{
+    if (w->sections.memory)
+    {
+        fprintf(stderr, "%s: ignoring duplicate section\n", __func__);
+        return 0;
+    }
+
+    const long offset = ftell(f);
+
+    if (offset < 0)
+    {
+        fprintf(stderr, "%s: ftell(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+    else if (check(f, len))
+    {
+        fprintf(stderr, "%s: check failed\n", __func__);
+        return -1;
+    }
+
+    w->sections.memory = offset;
+    return 0;
+}
diff --git a/src/section/start.c b/src/section/start.c
new file mode 100644
index 0000000..821525d
--- /dev/null
+++ b/src/section/start.c
@@ -0,0 +1,8 @@
+#include <sections.h>
+#include <wasm_types.h>
+
+int section_start(struct wasmfs *const w, FILE *const f,
+    const unsigned long len)
+{
+    return -1;
+}
diff --git a/src/section/table.c b/src/section/table.c
new file mode 100644
index 0000000..9f793c7
--- /dev/null
+++ b/src/section/table.c
@@ -0,0 +1,96 @@
+#include <sections.h>
+#include <wasm_types.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+
+static int check_table_type(FILE *const f)
+{
+    enum {ANYFUNC = 0x70};
+    varint7 elem_type;
+
+    if (varint7_read(f, &elem_type))
+    {
+        fprintf(stderr, "%s: varint7_read failed\n", __func__);
+        return -1;
+    }
+    else if (elem_type != ANYFUNC)
+    {
+        fprintf(stderr, "%s: expected %x, got %x", __func__, ANYFUNC,
+            (int)elem_type);
+        return -1;
+    }
+
+    return check_resizable_limits(f);
+}
+
+static int check(FILE *const f, const unsigned long len)
+{
+    const long start = ftell(f);
+
+    if (start < 0)
+    {
+        fprintf(stderr, "%s: ftell(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+
+    varuint32 count;
+
+    if (varuint32_read(f, &count))
+    {
+        fprintf(stderr, "%s: varuint32_read failed\n", __func__);
+        return -1;
+    }
+
+    for (varuint32 i = 0; i < count; i++)
+        if (check_table_type(f))
+        {
+            fprintf(stderr, "%s: check_table_type failed\n", __func__);
+            return -1;
+        }
+
+    const long end = ftell(f);
+
+    if (end < 0)
+    {
+        fprintf(stderr, "%s: ftell(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+
+    const unsigned long size = end - start;
+
+    if (size != len)
+    {
+        fprintf(stderr, "%s: size exceeded (%lu expected, got %lu)\n",
+                __func__, len, size);
+        return -1;
+    }
+
+    return 0;
+}
+
+int section_table(struct wasmfs *const w, FILE *const f,
+    const unsigned long len)
+{
+    if (w->sections.table)
+    {
+        fprintf(stderr, "%s: ignoring duplicate section\n", __func__);
+        return 0;
+    }
+
+    const long offset = ftell(f);
+
+    if (offset < 0)
+    {
+        fprintf(stderr, "%s: ftell(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+    else if (check(f, len))
+    {
+        fprintf(stderr, "%s: check failed\n", __func__);
+        return -1;
+    }
+
+    w->sections.table = offset;
+    return 0;
+}
diff --git a/src/section/type.c b/src/section/type.c
new file mode 100644
index 0000000..fad2208
--- /dev/null
+++ b/src/section/type.c
@@ -0,0 +1,126 @@
+#include <sections.h>
+#include <wasm_types.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+
+static int check_value_type(FILE *const f)
+{
+    varint7 value_type;
+
+    if (varint7_read(f, &value_type))
+    {
+        fprintf(stderr, "%s: varint7_read failed\n", __func__);
+        return -1;
+    }
+
+    return 0;
+}
+
+static int check_func_type(FILE *const f)
+{
+    varint7 form;
+    varuint32 param_count;
+
+    if (varint7_read(f, &form))
+    {
+        fprintf(stderr, "%s: varint7_read failed\n", __func__);
+        return -1;
+    }
+    else if (varuint32_read(f, &param_count))
+    {
+        fprintf(stderr, "%s: varuint32_read failed\n", __func__);
+        return -1;
+    }
+
+    for (varuint32 i = 0; i < param_count; i++)
+        if (check_value_type(f))
+        {
+            fprintf(stderr, "%s: check_value_type failed\n", __func__);
+            return -1;
+        }
+
+    varuint1 return_count;
+
+    if (varuint1_read(f, &return_count))
+    {
+        fprintf(stderr, "%s: varuint1_read failed\n", __func__);
+        return -1;
+    }
+    else if (return_count && check_value_type(f))
+    {
+        fprintf(stderr, "%s: check_value_type 2 failed\n", __func__);
+        return -1;
+    }
+
+    return 0;
+}
+
+static int check(FILE *const f, const unsigned long len)
+{
+    const long start = ftell(f);
+    varuint32 count;
+
+    if (start < 0)
+    {
+        fprintf(stderr, "%s: ftell(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+    else if (varuint32_read(f, &count))
+    {
+        fprintf(stderr, "%s: varuint32_read failed\n", __func__);
+        return -1;
+    }
+
+    for (varuint32 i = 0; i < count; i++)
+        if (check_func_type(f))
+        {
+            fprintf(stderr, "%s: check_func_type failed\n", __func__);
+            return -1;
+        }
+
+    const long end = ftell(f);
+
+    if (end < 0)
+    {
+        fprintf(stderr, "%s: ftell(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+
+    const unsigned long size = end - start;
+
+    if (size != len)
+    {
+        fprintf(stderr, "%s: size exceeded (%lu expected, got %lu)\n",
+                __func__, len, size);
+        return -1;
+    }
+
+    return 0;
+}
+
+int section_type(struct wasmfs *const w, FILE *const f,
+    const unsigned long len)
+{
+    if (w->sections.type)
+    {
+        fprintf(stderr, "%s: ignoring duplicate section\n", __func__);
+        return 0;
+    }
+
+    const long offset = ftell(f);
+
+    if (offset < 0)
+    {
+        fprintf(stderr, "%s: ftell(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+    else if (check(f, len))
+    {
+        fprintf(stderr, "%s: check failed\n", __func__);
+        return -1;
+    }
+
+    w->sections.type = offset;
+    return 0;
+}