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#include <wasmfs.h>
#include <sections.h>
#include <wasm_types.h>
#include <errno.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
static int failed_read(FILE *const f)
{
return fprintf(stderr, "%s: fread(3) failed, feof=%d, ferror=%d\n",
__func__, feof(f), ferror(f));
}
static int check_magic(FILE *const f)
{
static const uint8_t m[] = {'\0', 'a', 's', 'm'};
uint8_t magic[sizeof m];
if (!fread(magic, sizeof magic, 1, f))
{
failed_read(f);
return -1;
}
else if (memcmp(magic, m, sizeof magic))
{
fprintf(stderr, "%s: wrong magic bytes\n", __func__);
return -1;
}
return 0;
}
static int check_version(FILE *const f)
{
static const uint8_t v[] = {1, 0, 0, 0};
uint8_t version[sizeof v];
if (!fread(version, sizeof version, 1, f))
{
failed_read(f);
return -1;
}
else if (memcmp(version, v, sizeof version))
{
fprintf(stderr, "%s: wrong version\n", __func__);
return -1;
}
return 0;
}
static int load_section(struct wasmfs *const w, FILE *const f)
{
enum
{
CUSTOM,
TYPE,
IMPORT,
FUNCTION,
TABLE,
MEMORY,
GLOBAL,
EXPORT,
START,
ELEMENT,
CODE,
DATA
};
static int (*const fn[])(struct wasmfs *, FILE *, unsigned long) =
{
[CUSTOM] = section_custom,
[TYPE] = section_type,
[IMPORT] = section_import,
[FUNCTION] = section_function,
[TABLE] = section_table,
[MEMORY] = section_memory,
[GLOBAL] = section_global,
[EXPORT] = section_export,
[START] = section_start,
[ELEMENT] = section_element,
[CODE] = section_code,
[DATA] = section_data
};
varuint7 section;
varuint32 len;
int ret;
if (varuint7_read(f, §ion))
{
if (feof(f))
return 0;
fprintf(stderr, "%s: varuint7_read failed\n", __func__);
return 1;
}
else if (section >= sizeof fn / sizeof *fn)
{
fprintf(stderr, "%s: invalid section %u\n", __func__,
(unsigned)section);
return 1;
}
else if (varuint32_read(f, &len))
{
fprintf(stderr, "%s: varuint32_read failed\n", __func__);
return 1;
}
else if ((ret = fn[section](w, f, len)))
fprintf(stderr, "%s: failed to load section %u\n", __func__,
(unsigned)section);
return ret;
}
static int load_sections(struct wasmfs *const w, FILE *const f)
{
while (!feof(f))
if (load_section(w, f))
{
fprintf(stderr, "%s: load_section failed\n", __func__);
return -1;
}
return 0;
}
static int load(struct wasmfs *const w, FILE *const f)
{
if (check_magic(f))
{
fprintf(stderr, "%s: load_magic failed\n", __func__);
return -1;
}
else if (check_version(f))
{
fprintf(stderr, "%s: check_version failed\n", __func__);
return -1;
}
else if (load_sections(w, f))
{
fprintf(stderr, "%s: load_sections failed\n", __func__);
return -1;
}
return 0;
}
struct wasmfs *wasmfs_load(const char *const path)
{
struct wasmfs *ret = NULL, *w = NULL;
char *pathdup = NULL;
FILE *const f = fopen(path, "rb");
const size_t sz = strlen(path) + 1;
if (!f)
{
fprintf(stderr, "%s: fopen(3) %s: %s\n", __func__, path,
strerror(errno));
goto end;
}
else if (!(w = malloc(sizeof *w)))
{
fprintf(stderr, "%s: malloc(3) w: %s\n", __func__, strerror(errno));
goto end;
}
else if (!(pathdup = malloc(sz)))
{
fprintf(stderr, "%s: malloc(3) pathdup: %s\n", __func__,
strerror(errno));
goto end;
}
memcpy(pathdup, path, sz);
*w = (const struct wasmfs)
{
.path = pathdup
};
if (load(w, f))
{
fprintf(stderr, "%s: load failed\n", __func__);
goto end;
}
ret = w;
end:
if (f && fclose(f))
{
fprintf(stderr, "%s: fclose(3) %s: %s\n", __func__, path,
strerror(errno));
ret = NULL;
}
if (!ret)
wasmfs_unload(w);
return ret;
}
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