Add option to preserve symlinks exactly
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The "--preserve-symlinks" option preserves the symlink target instead of
deriving absolute/relative-paths from it. If archived symlinks are
absolute-paths, then it is NOT recommended to use this option as the
symlinks can be clobbered on extraction (unless if "--no-safe-links" is
specified on extraction).
This commit is contained in:
Stephen Seo 2024-10-24 16:37:55 +09:00
parent f81d007e7c
commit a415ab22ad
4 changed files with 158 additions and 46 deletions

View file

@ -27,6 +27,7 @@ API calls.
--overwrite-create : allows overwriting an archive file
--overwrite-extract : allows overwriting when extracting
--no-abs-symlink : do not store absolute paths for symlinks
--preserve-symlinks : preserve the symlink's path on archive creation instead of deriving abs/relative paths, ignores "--no-abs-symlink" (It is not recommended to use this option, as absolute-path-symlinks may be clobbered on extraction)
--no-safe-links : keep symlinks that link to outside archive contents
--temp-files-dir <dir> : where to store temporary files created when compressing (defaults to current working directory)
--write-version <version> : Force write version file format (default 1)

View file

@ -759,32 +759,49 @@ int write_files_fn(void *data, void *ud) {
// Get absolute path.
__attribute__((cleanup(
simple_archiver_helper_cleanup_malloced))) void *abs_path = NULL;
#if SIMPLE_ARCHIVER_PLATFORM == SIMPLE_ARCHIVER_PLATFORM_COSMOPOLITAN || \
SIMPLE_ARCHIVER_PLATFORM == SIMPLE_ARCHIVER_PLATFORM_MAC || \
SIMPLE_ARCHIVER_PLATFORM == SIMPLE_ARCHIVER_PLATFORM_LINUX
abs_path = realpath(file_info->filename, NULL);
#endif
__attribute__((cleanup(
simple_archiver_helper_cleanup_malloced))) void *rel_path = NULL;
if (abs_path) {
// Get relative path.
// First get absolute path of link.
__attribute__((cleanup(
simple_archiver_helper_cleanup_malloced))) void *link_abs_path =
simple_archiver_file_abs_path(file_info->filename);
if (!link_abs_path) {
fprintf(stderr, "WARNING: Failed to get absolute path of link!\n");
} else {
// fprintf(stderr, "DEBUG: abs_path: %s\nDEBUG: link_abs_path: %s\n",
// (char*)abs_path, (char*)link_abs_path);
rel_path =
simple_archiver_filenames_to_relative_path(link_abs_path, abs_path);
if ((state->parsed->flags & 0x100) != 0) {
// Preserve symlink target.
char *path_buf = malloc(1024);
ssize_t ret = readlink(file_info->filename, path_buf, 1023);
if (ret == -1) {
fprintf(stderr, "WARNING: Failed to get symlink's target!\n");
free(path_buf);
((uint8_t *)temp_to_write->buf)[1] |= 0x8;
} else {
path_buf[ret] = 0;
if (path_buf[0] == '/') {
abs_path = path_buf;
((uint8_t *)temp_to_write->buf)[1] |= 0x4;
} else {
rel_path = path_buf;
}
}
} else {
abs_path = realpath(file_info->filename, NULL);
if (abs_path) {
// Get relative path.
// First get absolute path of link.
__attribute__((cleanup(
simple_archiver_helper_cleanup_malloced))) void *link_abs_path =
simple_archiver_file_abs_path(file_info->filename);
if (!link_abs_path) {
fprintf(stderr, "WARNING: Failed to get absolute path of link!\n");
} else {
// fprintf(stderr, "DEBUG: abs_path: %s\nDEBUG: link_abs_path: %s\n",
// (char*)abs_path, (char*)link_abs_path);
rel_path = simple_archiver_filenames_to_relative_path(link_abs_path,
abs_path);
}
}
}
// Check if absolute path refers to one of the filenames.
if (abs_path && (state->parsed->flags & 0x20) == 0 &&
(state->parsed->flags & 0x100) == 0 &&
!simple_archiver_hash_map_get(state->map, abs_path,
strlen(abs_path) + 1)) {
// Is not a filename being archived.
@ -804,6 +821,34 @@ int write_files_fn(void *data, void *ud) {
file_info->filename);
((uint8_t *)temp_to_write->buf)[1] |= 0x8;
}
} else if ((state->parsed->flags & 0x100) != 0 &&
(state->parsed->flags & 0x80) == 0 &&
(((uint8_t *)temp_to_write->buf)[1] & 0x8) == 0) {
__attribute__((cleanup(
simple_archiver_helper_cleanup_c_string))) char *resolved_path = NULL;
if (abs_path || rel_path) {
resolved_path = realpath(file_info->filename, NULL);
if (!resolved_path) {
fprintf(stderr,
"WARNING: Symlink \"%s\" is invalid, will not be stored! "
"(Use \"--no-safe-links\" to disable this behavior)\n",
file_info->filename);
((uint8_t *)temp_to_write->buf)[1] |= 0x8;
} else if (!simple_archiver_hash_map_get(state->map, resolved_path,
strlen(resolved_path) + 1)) {
fprintf(stderr,
"WARNING: Symlink \"%s\" points to outside archive contents, "
"will not be stored! (Use \"--no-safe-links\" to disable "
"this behavior)\n",
file_info->filename);
((uint8_t *)temp_to_write->buf)[1] |= 0x8;
}
} else {
fprintf(stderr,
"WARNING: Unable to get target path from symlink \"%s\"!\n",
file_info->filename);
((uint8_t *)temp_to_write->buf)[1] |= 0x8;
}
}
if (!abs_path && !rel_path) {
@ -831,8 +876,10 @@ int write_files_fn(void *data, void *ud) {
// Store the absolute and relative paths.
if (!abs_path) {
fprintf(stderr,
"WARNING: Failed to get absolute path of link destination!\n");
if ((state->parsed->flags & 0x100) == 0) {
fprintf(stderr,
"WARNING: Failed to get absolute path of link destination!\n");
}
temp_to_write = malloc(sizeof(SDArchiverInternalToWrite));
temp_to_write->buf = malloc(2);
temp_to_write->size = 2;
@ -905,9 +952,17 @@ int write_files_fn(void *data, void *ud) {
// Write all previously set data.
fprintf(stderr, "Writing symlink info: %s\n", file_info->filename);
if ((state->parsed->flags & 0x20) == 0) {
fprintf(stderr, " abs path: %s\n", (char *)abs_path);
if (abs_path) {
fprintf(stderr, " abs path: %s\n", (char *)abs_path);
} else {
fprintf(stderr, " abs path is NOT set\n");
}
}
if (rel_path) {
fprintf(stderr, " rel path: %s\n", (char *)rel_path);
} else {
fprintf(stderr, " rel path is NOT set\n");
}
fprintf(stderr, " rel path: %s\n", (char *)rel_path);
simple_archiver_list_get(to_write, write_list_datas_fn, state->out_f);
simple_archiver_list_free(&to_write);
}
@ -983,10 +1038,15 @@ int filenames_to_abs_map_fn(void *data, void *ud) {
char *fullpath_dirname_copy = malloc(strlen(fullpath_dirname) + 1);
strncpy(fullpath_dirname_copy, fullpath_dirname,
strlen(fullpath_dirname) + 1);
simple_archiver_hash_map_insert(
abs_filenames, fullpath_dirname_copy, fullpath_dirname_copy,
strlen(fullpath_dirname_copy) + 1,
simple_archiver_helper_datastructure_cleanup_nop, NULL);
if (!simple_archiver_hash_map_get(abs_filenames, fullpath_dirname_copy,
strlen(fullpath_dirname_copy) + 1)) {
simple_archiver_hash_map_insert(
abs_filenames, fullpath_dirname_copy, fullpath_dirname_copy,
strlen(fullpath_dirname_copy) + 1,
simple_archiver_helper_datastructure_cleanup_nop, NULL);
} else {
free(fullpath_dirname_copy);
}
}
prev = fullpath_dirname;
}
@ -2091,30 +2151,51 @@ int simple_archiver_write_v1(FILE *out_f, SDArchiverState *state,
node = node->next;
++u32;
memset(buf, 0, 2);
#if SIMPLE_ARCHIVER_PLATFORM == SIMPLE_ARCHIVER_PLATFORM_COSMOPOLITAN || \
SIMPLE_ARCHIVER_PLATFORM == SIMPLE_ARCHIVER_PLATFORM_MAC || \
SIMPLE_ARCHIVER_PLATFORM == SIMPLE_ARCHIVER_PLATFORM_LINUX
// Check if symlink points to thing to be stored into archive.
__attribute__((
cleanup(simple_archiver_helper_cleanup_malloced))) void *abs_path =
realpath(node->data, NULL);
__attribute__((cleanup(
simple_archiver_helper_cleanup_malloced))) void *rel_path = NULL;
if (abs_path) {
__attribute__((cleanup(
simple_archiver_helper_cleanup_malloced))) void *link_abs_path =
simple_archiver_file_abs_path(node->data);
if (!link_abs_path) {
fprintf(stderr, "WARNING: Failed to get absolute path to link!\n");
} else {
rel_path = simple_archiver_filenames_to_relative_path(link_abs_path,
abs_path);
}
}
uint_fast8_t is_invalid = 0;
#if SIMPLE_ARCHIVER_PLATFORM == SIMPLE_ARCHIVER_PLATFORM_COSMOPOLITAN || \
SIMPLE_ARCHIVER_PLATFORM == SIMPLE_ARCHIVER_PLATFORM_MAC || \
SIMPLE_ARCHIVER_PLATFORM == SIMPLE_ARCHIVER_PLATFORM_LINUX
__attribute__((cleanup(
simple_archiver_helper_cleanup_malloced))) void *abs_path = NULL;
__attribute__((cleanup(
simple_archiver_helper_cleanup_malloced))) void *rel_path = NULL;
if ((state->parsed->flags & 0x100) != 0) {
// Preserve symlink target.
char *path_buf = malloc(1024);
ssize_t ret = readlink(node->data, path_buf, 1023);
if (ret == -1) {
fprintf(stderr, "WARNING: Failed to get symlink's target!\n");
free(path_buf);
is_invalid = 1;
} else {
path_buf[ret] = 0;
if (path_buf[0] == '/') {
abs_path = path_buf;
buf[0] |= 1;
} else {
rel_path = path_buf;
}
}
} else {
abs_path = realpath(node->data, NULL);
// Check if symlink points to thing to be stored into archive.
if (abs_path) {
__attribute__((cleanup(
simple_archiver_helper_cleanup_malloced))) void *link_abs_path =
simple_archiver_file_abs_path(node->data);
if (!link_abs_path) {
fprintf(stderr, "WARNING: Failed to get absolute path to link!\n");
} else {
rel_path = simple_archiver_filenames_to_relative_path(link_abs_path,
abs_path);
}
}
}
if (abs_path && (state->parsed->flags & 0x20) == 0 &&
(state->parsed->flags & 0x100) == 0 &&
!simple_archiver_hash_map_get(abs_filenames, abs_path,
strlen(abs_path) + 1)) {
// Is not a filename being archived.
@ -2130,6 +2211,27 @@ int simple_archiver_write_v1(FILE *out_f, SDArchiverState *state,
// Safe links disabled, set preference to absolute path.
buf[0] |= 1;
}
} else if ((state->parsed->flags & 0x100) != 0 &&
(state->parsed->flags & 0x80) == 0 && !is_invalid) {
__attribute__((cleanup(
simple_archiver_helper_cleanup_c_string))) char *target_realpath =
realpath(node->data, NULL);
if (!target_realpath) {
fprintf(
stderr,
"WARNING: \"%s\" is an invalid symlink and \"--no-safe-links\" "
"not specified, will skip this symlink!\n",
(const char *)node->data);
is_invalid = 1;
} else if (!simple_archiver_hash_map_get(abs_filenames, target_realpath,
strlen(target_realpath) + 1)) {
fprintf(
stderr,
"WARNING: \"%s\" points to outside of archived files and "
"\"--no-safe-links\" not specified, will skip this symlink!\n",
(const char *)node->data);
is_invalid = 1;
}
}
if (!abs_path && !rel_path) {

View file

@ -168,6 +168,12 @@ void simple_archiver_print_usage(void) {
fprintf(stderr, "--overwrite-extract : allows overwriting when extracting\n");
fprintf(stderr,
"--no-abs-symlink : do not store absolute paths for symlinks\n");
fprintf(
stderr,
"--preserve-symlinks : preserve the symlink's path on archive creation "
"instead of deriving abs/relative paths, ignores \"--no-abs-symlink\" "
"(It is not recommended to use this option, as absolute-path-symlinks "
"may be clobbered on extraction)\n");
fprintf(stderr,
"--no-safe-links : keep symlinks that link to outside archive "
"contents\n");
@ -306,6 +312,8 @@ int simple_archiver_parse_args(int argc, const char **argv,
out->flags |= 0x8;
} else if (strcmp(argv[0], "--no-abs-symlink") == 0) {
out->flags |= 0x20;
} else if (strcmp(argv[0], "--preserve-symlinks") == 0) {
out->flags |= 0x100;
} else if (strcmp(argv[0], "--no-safe-links") == 0) {
out->flags |= 0x80;
fprintf(stderr,

View file

@ -37,6 +37,7 @@ typedef struct SDArchiverParsed {
/// 0b xx1x xxxx - Do not save absolute paths for symlinks.
/// 0b x1xx xxxx - Sort files by size before archiving.
/// 0b 1xxx xxxx - No safe links.
/// 0b xxxx xxx1 xxxx xxxx - Preserve symlink target.
uint32_t flags;
/// Null-terminated string.
char *filename;