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-rw-r--r--src/basic/fs-util.c165
-rw-r--r--src/test/test-fs-util.c4
2 files changed, 58 insertions, 111 deletions
diff --git a/src/basic/fs-util.c b/src/basic/fs-util.c
index a4d772777e..e9fdb75a23 100644
--- a/src/basic/fs-util.c
+++ b/src/basic/fs-util.c
@@ -775,9 +775,9 @@ int chase_symlinks(const char *path, const char *original_root, unsigned flags,
_cleanup_free_ char *buffer = NULL, *done = NULL, *root = NULL;
_cleanup_close_ int fd = -1;
unsigned max_follow = CHASE_SYMLINKS_MAX; /* how many symlinks to follow before giving up and returning ELOOP */
+ bool exists = true, append_trail_slash = false;
struct stat previous_stat;
- bool exists = true;
- char *todo;
+ const char *todo;
int r;
assert(path);
@@ -885,84 +885,51 @@ int chase_symlinks(const char *path, const char *original_root, unsigned flags,
if (fd < 0)
return -errno;
- if (flags & CHASE_SAFE) {
+ if (flags & CHASE_SAFE)
if (fstat(fd, &previous_stat) < 0)
return -errno;
- }
- if (root) {
- _cleanup_free_ char *absolute = NULL;
- const char *e;
+ if (flags & CHASE_TRAIL_SLASH)
+ append_trail_slash = endswith(buffer, "/") || endswith(buffer, "/.");
+ if (root) {
/* If we are operating on a root directory, let's take the root directory as it is. */
- e = path_startswith(buffer, root);
- if (!e)
+ todo = path_startswith(buffer, root);
+ if (!todo)
return log_full_errno(flags & CHASE_WARN ? LOG_WARNING : LOG_DEBUG,
SYNTHETIC_ERRNO(ECHRNG),
"Specified path '%s' is outside of specified root directory '%s', refusing to resolve.",
path, root);
done = strdup(root);
- if (!done)
- return -ENOMEM;
-
- /* Make sure "todo" starts with a slash */
- absolute = strjoin("/", e);
- if (!absolute)
- return -ENOMEM;
-
- free_and_replace(buffer, absolute);
+ } else {
+ todo = buffer;
+ done = strdup("/");
}
- todo = buffer;
for (;;) {
_cleanup_free_ char *first = NULL;
_cleanup_close_ int child = -1;
struct stat st;
- size_t n, m;
-
- /* Determine length of first component in the path */
- n = strspn(todo, "/"); /* The slashes */
-
- if (n > 1) {
- /* If we are looking at more than a single slash then skip all but one, so that when
- * we are done with everything we have a normalized path with only single slashes
- * separating the path components. */
- todo += n - 1;
- n = 1;
- }
-
- m = n + strcspn(todo + n, "/"); /* The entire length of the component */
-
- /* Extract the first component. */
- first = strndup(todo, m);
- if (!first)
- return -ENOMEM;
-
- todo += m;
-
- /* Empty? Then we reached the end. */
- if (isempty(first))
- break;
-
- /* Just a single slash? Then we reached the end. */
- if (path_equal(first, "/")) {
- /* Preserve the trailing slash */
+ const char *e;
- if (flags & CHASE_TRAIL_SLASH)
+ r = path_find_first_component(&todo, true, &e);
+ if (r < 0)
+ return r;
+ if (r == 0) { /* We reached the end. */
+ if (append_trail_slash)
if (!strextend(&done, "/"))
return -ENOMEM;
-
break;
}
- /* Just a dot? Then let's eat this up. */
- if (path_equal(first, "/."))
- continue;
+ first = strndup(e, r);
+ if (!first)
+ return -ENOMEM;
/* Two dots? Then chop off the last bit of what we already found out. */
- if (path_equal(first, "/..")) {
+ if (path_equal(first, "..")) {
_cleanup_free_ char *parent = NULL;
_cleanup_close_ int fd_parent = -1;
@@ -1007,22 +974,16 @@ int chase_symlinks(const char *path, const char *original_root, unsigned flags,
}
/* Otherwise let's see what this is. */
- child = openat(fd, first + n, O_CLOEXEC|O_NOFOLLOW|O_PATH);
+ child = openat(fd, first, O_CLOEXEC|O_NOFOLLOW|O_PATH);
if (child < 0) {
-
if (errno == ENOENT &&
(flags & CHASE_NONEXISTENT) &&
- (isempty(todo) || path_is_normalized(todo))) {
-
- /* If CHASE_NONEXISTENT is set, and the path does not exist, then that's OK, return
- * what we got so far. But don't allow this if the remaining path contains "../ or "./"
- * or something else weird. */
+ (isempty(todo) || path_is_safe(todo))) {
+ /* If CHASE_NONEXISTENT is set, and the path does not exist, then
+ * that's OK, return what we got so far. But don't allow this if the
+ * remaining path contains "../" or something else weird. */
- /* If done is "/", as first also contains slash at the head, then remove this redundant slash. */
- if (streq_ptr(done, "/"))
- *done = '\0';
-
- if (!strextend(&done, first, todo))
+ if (!path_extend(&done, first, todo))
return -ENOMEM;
exists = false;
@@ -1045,15 +1006,14 @@ int chase_symlinks(const char *path, const char *original_root, unsigned flags,
return log_autofs_mount_point(child, path, flags);
if (S_ISLNK(st.st_mode) && !((flags & CHASE_NOFOLLOW) && isempty(todo))) {
- char *joined;
_cleanup_free_ char *destination = NULL;
- /* This is a symlink, in this case read the destination. But let's make sure we don't follow
- * symlinks without bounds. */
+ /* This is a symlink, in this case read the destination. But let's make sure we
+ * don't follow symlinks without bounds. */
if (--max_follow <= 0)
return -ELOOP;
- r = readlinkat_malloc(fd, first + n, &destination);
+ r = readlinkat_malloc(fd, first, &destination);
if (r < 0)
return r;
if (isempty(destination))
@@ -1079,27 +1039,19 @@ int chase_symlinks(const char *path, const char *original_root, unsigned flags,
previous_stat = st;
}
- free(done);
-
/* Note that we do not revalidate the root, we take it as is. */
- if (isempty(root))
- done = NULL;
- else {
- done = strdup(root);
- if (!done)
- return -ENOMEM;
- }
+ r = free_and_strdup(&done, empty_to_root(root));
+ if (r < 0)
+ return r;
+ }
- /* Prefix what's left to do with what we just read, and start the loop again, but
- * remain in the current directory. */
- joined = path_join(destination, todo);
- } else
- joined = path_join("/", destination, todo);
- if (!joined)
+ /* Prefix what's left to do with what we just read, and start the loop again, but
+ * remain in the current directory. */
+ if (!path_extend(&destination, todo))
return -ENOMEM;
- free(buffer);
- todo = buffer = joined;
+ free_and_replace(buffer, destination);
+ todo = buffer;
if (flags & CHASE_STEP)
goto chased_one;
@@ -1108,29 +1060,14 @@ int chase_symlinks(const char *path, const char *original_root, unsigned flags,
}
/* If this is not a symlink, then let's just add the name we read to what we already verified. */
- if (!done)
- done = TAKE_PTR(first);
- else {
- /* If done is "/", as first also contains slash at the head, then remove this redundant slash. */
- if (streq(done, "/"))
- *done = '\0';
-
- if (!strextend(&done, first))
- return -ENOMEM;
- }
+ if (!path_extend(&done, first))
+ return -ENOMEM;
/* And iterate again, but go one directory further down. */
safe_close(fd);
fd = TAKE_FD(child);
}
- if (!done) {
- /* Special case, turn the empty string into "/", to indicate the root directory. */
- done = strdup("/");
- if (!done)
- return -ENOMEM;
- }
-
if (ret_path)
*ret_path = TAKE_PTR(done);
@@ -1149,13 +1086,23 @@ int chase_symlinks(const char *path, const char *original_root, unsigned flags,
chased_one:
if (ret_path) {
- char *c;
+ const char *e;
- c = strjoin(strempty(done), todo);
- if (!c)
- return -ENOMEM;
+ /* todo may contain slashes at the beginning. */
+ r = path_find_first_component(&todo, true, &e);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ *ret_path = TAKE_PTR(done);
+ else {
+ char *c;
- *ret_path = c;
+ c = path_join(done, e);
+ if (!c)
+ return -ENOMEM;
+
+ *ret_path = c;
+ }
}
return 0;
diff --git a/src/test/test-fs-util.c b/src/test/test-fs-util.c
index c42c48722f..63bb830370 100644
--- a/src/test/test-fs-util.c
+++ b/src/test/test-fs-util.c
@@ -332,7 +332,7 @@ static void test_chase_symlinks(void) {
assert_se(S_ISLNK(st.st_mode));
result = mfree(result);
- /* Test CHASE_ONE */
+ /* Test CHASE_STEP */
p = strjoina(temp, "/start");
r = chase_symlinks(p, NULL, CHASE_STEP, &result, NULL);
@@ -343,7 +343,7 @@ static void test_chase_symlinks(void) {
r = chase_symlinks(p, NULL, CHASE_STEP, &result, NULL);
assert_se(r == 0);
- p = strjoina(temp, "/top/./dotdota");
+ p = strjoina(temp, "/top/dotdota");
assert_se(streq(p, result));
result = mfree(result);
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