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core/iwasm: Support mapped file system access on non-libuv WASI (#2628)

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This patch enables mapping host directories to guest directories by parsing
the `map_dir_list` argument in API `wasm_runtime_init_wasi` for libc-wasi. It
follows the format `<guest-path>::<host-path>`.

It also adds argument `--map-dir=<guest::host>` argument for `iwasm`
common line tool, and allows to add multiple mappings:
```bash
iwasm --map-dir=<guest-path1::host-path1> --map-dir=<guest-path2::host-path2> ...
```
This commit is contained in:
Alfred E. Neumayer
2023-10-27 06:48:10 +02:00
committed by GitHub
parent 8038b9c524
commit 9b8fe049b3
3 changed files with 95 additions and 4 deletions
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78
core/iwasm/common/wasm_runtime_common.c
View File

@ -3012,8 +3012,82 @@ wasm_runtime_init_wasi(WASMModuleInstanceCommon *module_inst,
goto fail;
}
fd_table_insert_existing(curfds, wasm_fd, raw_fd);
fd_prestats_insert(prestats, dir_list[i], wasm_fd);
if (!fd_table_insert_existing(curfds, wasm_fd, raw_fd)
|| !fd_prestats_insert(prestats, dir_list[i], wasm_fd)) {
if (error_buf)
snprintf(
error_buf, error_buf_size,
"error while pre-opening directory %s: insertion failed\n",
dir_list[i]);
goto fail;
}
}
for (i = 0; i < map_dir_count; i++, wasm_fd++) {
char mapping_copy_buf[256];
char *mapping_copy = mapping_copy_buf;
char *map_mapped = NULL, *map_host = NULL;
const unsigned long max_len = strlen(map_dir_list[i]) * 2 + 3;
/* Allocation limit for runtime environments with reduced stack size */
if (max_len > 256) {
if (!(mapping_copy = wasm_runtime_malloc(max_len))) {
snprintf(error_buf, error_buf_size,
"error while allocating for directory mapping\n");
goto fail;
}
}
strncpy(mapping_copy, map_dir_list[i], strlen(map_dir_list[i]) + 1);
map_mapped = strtok(mapping_copy, "::");
map_host = strtok(NULL, "::");
if (!map_mapped || !map_host) {
if (error_buf)
snprintf(error_buf, error_buf_size,
"error while pre-opening mapped directory: "
"invalid map\n");
if (mapping_copy != mapping_copy_buf)
wasm_runtime_free(mapping_copy);
goto fail;
}
path = realpath(map_host, resolved_path);
if (!path) {
if (error_buf)
snprintf(error_buf, error_buf_size,
"error while pre-opening mapped directory %s: %d\n",
map_host, errno);
if (mapping_copy != mapping_copy_buf)
wasm_runtime_free(mapping_copy);
goto fail;
}
raw_fd = open(path, O_RDONLY | O_DIRECTORY, 0);
if (raw_fd == -1) {
if (error_buf)
snprintf(error_buf, error_buf_size,
"error while pre-opening mapped directory %s: %d\n",
map_host, errno);
if (mapping_copy != mapping_copy_buf)
wasm_runtime_free(mapping_copy);
goto fail;
}
if (!fd_table_insert_existing(curfds, wasm_fd, raw_fd)
|| !fd_prestats_insert(prestats, map_mapped, wasm_fd)) {
if (error_buf)
snprintf(error_buf, error_buf_size,
"error while pre-opening mapped directory %s: "
"insertion failed\n",
dir_list[i]);
if (mapping_copy != mapping_copy_buf)
wasm_runtime_free(mapping_copy);
goto fail;
}
if (mapping_copy != mapping_copy_buf)
wasm_runtime_free(mapping_copy);
}
/* addr_pool(textual) -> apool */

1
core/iwasm/include/wasm_export.h
View File

@ -423,6 +423,7 @@ wasm_runtime_get_module_hash(wasm_module_t module);
* @param dir_list The list of directories to preopen. (real path)
* @param dir_count The number of elements in dir_list.
* @param map_dir_list The list of directories to preopen. (mapped path)
* Format for each map entry: <guest-path>::<host-path>
* @param map_dir_count The number of elements in map_dir_list.
* If map_dir_count is smaller than dir_count,
* mapped path is assumed to be same as the