| /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
| |
| #include <errno.h> |
| #include <fnmatch.h> |
| #include <limits.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| |
| #include "alloc-util.h" |
| #include "chase-symlinks.h" |
| #include "extract-word.h" |
| #include "fd-util.h" |
| #include "fs-util.h" |
| #include "glob-util.h" |
| #include "log.h" |
| #include "macro.h" |
| #include "path-util.h" |
| #include "stat-util.h" |
| #include "string-util.h" |
| #include "strv.h" |
| #include "time-util.h" |
| |
| int path_split_and_make_absolute(const char *p, char ***ret) { |
| char **l; |
| int r; |
| |
| assert(p); |
| assert(ret); |
| |
| l = strv_split(p, ":"); |
| if (!l) |
| return -ENOMEM; |
| |
| r = path_strv_make_absolute_cwd(l); |
| if (r < 0) { |
| strv_free(l); |
| return r; |
| } |
| |
| *ret = l; |
| return r; |
| } |
| |
| char *path_make_absolute(const char *p, const char *prefix) { |
| assert(p); |
| |
| /* Makes every item in the list an absolute path by prepending |
| * the prefix, if specified and necessary */ |
| |
| if (path_is_absolute(p) || isempty(prefix)) |
| return strdup(p); |
| |
| return path_join(prefix, p); |
| } |
| |
| int safe_getcwd(char **ret) { |
| _cleanup_free_ char *cwd = NULL; |
| |
| cwd = get_current_dir_name(); |
| if (!cwd) |
| return negative_errno(); |
| |
| /* Let's make sure the directory is really absolute, to protect us from the logic behind |
| * CVE-2018-1000001 */ |
| if (cwd[0] != '/') |
| return -ENOMEDIUM; |
| |
| if (ret) |
| *ret = TAKE_PTR(cwd); |
| |
| return 0; |
| } |
| |
| int path_make_absolute_cwd(const char *p, char **ret) { |
| char *c; |
| int r; |
| |
| assert(p); |
| assert(ret); |
| |
| /* Similar to path_make_absolute(), but prefixes with the |
| * current working directory. */ |
| |
| if (path_is_absolute(p)) |
| c = strdup(p); |
| else { |
| _cleanup_free_ char *cwd = NULL; |
| |
| r = safe_getcwd(&cwd); |
| if (r < 0) |
| return r; |
| |
| c = path_join(cwd, p); |
| } |
| if (!c) |
| return -ENOMEM; |
| |
| *ret = c; |
| return 0; |
| } |
| |
| int path_make_relative(const char *from, const char *to, char **ret) { |
| _cleanup_free_ char *result = NULL; |
| unsigned n_parents; |
| const char *f, *t; |
| int r, k; |
| char *p; |
| |
| assert(from); |
| assert(to); |
| assert(ret); |
| |
| /* Strips the common part, and adds ".." elements as necessary. */ |
| |
| if (!path_is_absolute(from) || !path_is_absolute(to)) |
| return -EINVAL; |
| |
| for (;;) { |
| r = path_find_first_component(&from, true, &f); |
| if (r < 0) |
| return r; |
| |
| k = path_find_first_component(&to, true, &t); |
| if (k < 0) |
| return k; |
| |
| if (r == 0) { |
| /* end of 'from' */ |
| if (k == 0) { |
| /* from and to are equivalent. */ |
| result = strdup("."); |
| if (!result) |
| return -ENOMEM; |
| } else { |
| /* 'to' is inside of 'from'. */ |
| result = strdup(t); |
| if (!result) |
| return -ENOMEM; |
| |
| path_simplify(result); |
| |
| if (!path_is_valid(result)) |
| return -EINVAL; |
| } |
| |
| *ret = TAKE_PTR(result); |
| return 0; |
| } |
| |
| if (r != k || !strneq(f, t, r)) |
| break; |
| } |
| |
| /* If we're here, then "from_dir" has one or more elements that need to |
| * be replaced with "..". */ |
| |
| for (n_parents = 1;; n_parents++) { |
| /* If this includes ".." we can't do a simple series of "..". */ |
| r = path_find_first_component(&from, false, &f); |
| if (r < 0) |
| return r; |
| if (r == 0) |
| break; |
| } |
| |
| if (isempty(t) && n_parents * 3 > PATH_MAX) |
| /* PATH_MAX is counted *with* the trailing NUL byte */ |
| return -EINVAL; |
| |
| result = new(char, n_parents * 3 + !isempty(t) + strlen_ptr(t)); |
| if (!result) |
| return -ENOMEM; |
| |
| for (p = result; n_parents > 0; n_parents--) |
| p = mempcpy(p, "../", 3); |
| |
| if (isempty(t)) { |
| /* Remove trailing slash and terminate string. */ |
| *(--p) = '\0'; |
| *ret = TAKE_PTR(result); |
| return 0; |
| } |
| |
| strcpy(p, t); |
| |
| path_simplify(result); |
| |
| if (!path_is_valid(result)) |
| return -EINVAL; |
| |
| *ret = TAKE_PTR(result); |
| return 0; |
| } |
| |
| int path_make_relative_parent(const char *from_child, const char *to, char **ret) { |
| _cleanup_free_ char *from = NULL; |
| int r; |
| |
| assert(from_child); |
| assert(to); |
| assert(ret); |
| |
| /* Similar to path_make_relative(), but provides the relative path from the parent directory of |
| * 'from_child'. This may be useful when creating relative symlink. |
| * |
| * E.g. |
| * - from = "/path/to/aaa", to = "/path/to/bbb" |
| * path_make_relative(from, to) = "../bbb" |
| * path_make_relative_parent(from, to) = "bbb" |
| * |
| * - from = "/path/to/aaa/bbb", to = "/path/to/ccc/ddd" |
| * path_make_relative(from, to) = "../../ccc/ddd" |
| * path_make_relative_parent(from, to) = "../ccc/ddd" |
| */ |
| |
| r = path_extract_directory(from_child, &from); |
| if (r < 0) |
| return r; |
| |
| return path_make_relative(from, to, ret); |
| } |
| |
| char* path_startswith_strv(const char *p, char **set) { |
| STRV_FOREACH(s, set) { |
| char *t; |
| |
| t = path_startswith(p, *s); |
| if (t) |
| return t; |
| } |
| |
| return NULL; |
| } |
| |
| int path_strv_make_absolute_cwd(char **l) { |
| int r; |
| |
| /* Goes through every item in the string list and makes it |
| * absolute. This works in place and won't rollback any |
| * changes on failure. */ |
| |
| STRV_FOREACH(s, l) { |
| char *t; |
| |
| r = path_make_absolute_cwd(*s, &t); |
| if (r < 0) |
| return r; |
| |
| path_simplify(t); |
| free_and_replace(*s, t); |
| } |
| |
| return 0; |
| } |
| |
| char **path_strv_resolve(char **l, const char *root) { |
| unsigned k = 0; |
| bool enomem = false; |
| int r; |
| |
| if (strv_isempty(l)) |
| return l; |
| |
| /* Goes through every item in the string list and canonicalize |
| * the path. This works in place and won't rollback any |
| * changes on failure. */ |
| |
| STRV_FOREACH(s, l) { |
| _cleanup_free_ char *orig = NULL; |
| char *t, *u; |
| |
| if (!path_is_absolute(*s)) { |
| free(*s); |
| continue; |
| } |
| |
| if (root) { |
| orig = *s; |
| t = path_join(root, orig); |
| if (!t) { |
| enomem = true; |
| continue; |
| } |
| } else |
| t = *s; |
| |
| r = chase_symlinks(t, root, 0, &u, NULL); |
| if (r == -ENOENT) { |
| if (root) { |
| u = TAKE_PTR(orig); |
| free(t); |
| } else |
| u = t; |
| } else if (r < 0) { |
| free(t); |
| |
| if (r == -ENOMEM) |
| enomem = true; |
| |
| continue; |
| } else if (root) { |
| char *x; |
| |
| free(t); |
| x = path_startswith(u, root); |
| if (x) { |
| /* restore the slash if it was lost */ |
| if (!startswith(x, "/")) |
| *(--x) = '/'; |
| |
| t = strdup(x); |
| free(u); |
| if (!t) { |
| enomem = true; |
| continue; |
| } |
| u = t; |
| } else { |
| /* canonicalized path goes outside of |
| * prefix, keep the original path instead */ |
| free_and_replace(u, orig); |
| } |
| } else |
| free(t); |
| |
| l[k++] = u; |
| } |
| |
| l[k] = NULL; |
| |
| if (enomem) |
| return NULL; |
| |
| return l; |
| } |
| |
| char **path_strv_resolve_uniq(char **l, const char *root) { |
| |
| if (strv_isempty(l)) |
| return l; |
| |
| if (!path_strv_resolve(l, root)) |
| return NULL; |
| |
| return strv_uniq(l); |
| } |
| |
| char *path_simplify(char *path) { |
| bool add_slash = false; |
| char *f = ASSERT_PTR(path); |
| int r; |
| |
| /* Removes redundant inner and trailing slashes. Also removes unnecessary dots. |
| * Modifies the passed string in-place. |
| * |
| * ///foo//./bar/. becomes /foo/bar |
| * .//./foo//./bar/. becomes foo/bar |
| */ |
| |
| if (isempty(path)) |
| return path; |
| |
| if (path_is_absolute(path)) |
| f++; |
| |
| for (const char *p = f;;) { |
| const char *e; |
| |
| r = path_find_first_component(&p, true, &e); |
| if (r == 0) |
| break; |
| |
| if (add_slash) |
| *f++ = '/'; |
| |
| if (r < 0) { |
| /* if path is invalid, then refuse to simplify remaining part. */ |
| memmove(f, p, strlen(p) + 1); |
| return path; |
| } |
| |
| memmove(f, e, r); |
| f += r; |
| |
| add_slash = true; |
| } |
| |
| /* Special rule, if we stripped everything, we need a "." for the current directory. */ |
| if (f == path) |
| *f++ = '.'; |
| |
| *f = '\0'; |
| return path; |
| } |
| |
| char *path_startswith_full(const char *path, const char *prefix, bool accept_dot_dot) { |
| assert(path); |
| assert(prefix); |
| |
| /* Returns a pointer to the start of the first component after the parts matched by |
| * the prefix, iff |
| * - both paths are absolute or both paths are relative, |
| * and |
| * - each component in prefix in turn matches a component in path at the same position. |
| * An empty string will be returned when the prefix and path are equivalent. |
| * |
| * Returns NULL otherwise. |
| */ |
| |
| if ((path[0] == '/') != (prefix[0] == '/')) |
| return NULL; |
| |
| for (;;) { |
| const char *p, *q; |
| int r, k; |
| |
| r = path_find_first_component(&path, accept_dot_dot, &p); |
| if (r < 0) |
| return NULL; |
| |
| k = path_find_first_component(&prefix, accept_dot_dot, &q); |
| if (k < 0) |
| return NULL; |
| |
| if (k == 0) |
| return (char*) (p ?: path); |
| |
| if (r != k) |
| return NULL; |
| |
| if (!strneq(p, q, r)) |
| return NULL; |
| } |
| } |
| |
| int path_compare(const char *a, const char *b) { |
| int r; |
| |
| /* Order NULL before non-NULL */ |
| r = CMP(!!a, !!b); |
| if (r != 0) |
| return r; |
| |
| /* A relative path and an absolute path must not compare as equal. |
| * Which one is sorted before the other does not really matter. |
| * Here a relative path is ordered before an absolute path. */ |
| r = CMP(path_is_absolute(a), path_is_absolute(b)); |
| if (r != 0) |
| return r; |
| |
| for (;;) { |
| const char *aa, *bb; |
| int j, k; |
| |
| j = path_find_first_component(&a, true, &aa); |
| k = path_find_first_component(&b, true, &bb); |
| |
| if (j < 0 || k < 0) { |
| /* When one of paths is invalid, order invalid path after valid one. */ |
| r = CMP(j < 0, k < 0); |
| if (r != 0) |
| return r; |
| |
| /* fallback to use strcmp() if both paths are invalid. */ |
| return strcmp(a, b); |
| } |
| |
| /* Order prefixes first: "/foo" before "/foo/bar" */ |
| if (j == 0) { |
| if (k == 0) |
| return 0; |
| return -1; |
| } |
| if (k == 0) |
| return 1; |
| |
| /* Alphabetical sort: "/foo/aaa" before "/foo/b" */ |
| r = memcmp(aa, bb, MIN(j, k)); |
| if (r != 0) |
| return r; |
| |
| /* Sort "/foo/a" before "/foo/aaa" */ |
| r = CMP(j, k); |
| if (r != 0) |
| return r; |
| } |
| } |
| |
| bool path_equal_or_files_same(const char *a, const char *b, int flags) { |
| return path_equal(a, b) || files_same(a, b, flags) > 0; |
| } |
| |
| bool path_equal_filename(const char *a, const char *b) { |
| _cleanup_free_ char *a_basename = NULL, *b_basename = NULL; |
| int r; |
| |
| assert(a); |
| assert(b); |
| |
| r = path_extract_filename(a, &a_basename); |
| if (r < 0) { |
| log_debug_errno(r, "Failed to parse basename of %s: %m", a); |
| return false; |
| } |
| r = path_extract_filename(b, &b_basename); |
| if (r < 0) { |
| log_debug_errno(r, "Failed to parse basename of %s: %m", b); |
| return false; |
| } |
| |
| return path_equal(a_basename, b_basename); |
| } |
| |
| char* path_extend_internal(char **x, ...) { |
| size_t sz, old_sz; |
| char *q, *nx; |
| const char *p; |
| va_list ap; |
| bool slash; |
| |
| /* Joins all listed strings until the sentinel and places a "/" between them unless the strings |
| * end/begin already with one so that it is unnecessary. Note that slashes which are already |
| * duplicate won't be removed. The string returned is hence always equal to or longer than the sum of |
| * the lengths of the individual strings. |
| * |
| * The first argument may be an already allocated string that is extended via realloc() if |
| * non-NULL. path_extend() and path_join() are macro wrappers around this function, making use of the |
| * first parameter to distinguish the two operations. |
| * |
| * Note: any listed empty string is simply skipped. This can be useful for concatenating strings of |
| * which some are optional. |
| * |
| * Examples: |
| * |
| * path_join("foo", "bar") → "foo/bar" |
| * path_join("foo/", "bar") → "foo/bar" |
| * path_join("", "foo", "", "bar", "") → "foo/bar" */ |
| |
| sz = old_sz = x ? strlen_ptr(*x) : 0; |
| va_start(ap, x); |
| while ((p = va_arg(ap, char*)) != POINTER_MAX) { |
| size_t add; |
| |
| if (isempty(p)) |
| continue; |
| |
| add = 1 + strlen(p); |
| if (sz > SIZE_MAX - add) { /* overflow check */ |
| va_end(ap); |
| return NULL; |
| } |
| |
| sz += add; |
| } |
| va_end(ap); |
| |
| nx = realloc(x ? *x : NULL, GREEDY_ALLOC_ROUND_UP(sz+1)); |
| if (!nx) |
| return NULL; |
| if (x) |
| *x = nx; |
| |
| if (old_sz > 0) |
| slash = nx[old_sz-1] == '/'; |
| else { |
| nx[old_sz] = 0; |
| slash = true; /* no need to generate a slash anymore */ |
| } |
| |
| q = nx + old_sz; |
| |
| va_start(ap, x); |
| while ((p = va_arg(ap, char*)) != POINTER_MAX) { |
| if (isempty(p)) |
| continue; |
| |
| if (!slash && p[0] != '/') |
| *(q++) = '/'; |
| |
| q = stpcpy(q, p); |
| slash = endswith(p, "/"); |
| } |
| va_end(ap); |
| |
| return nx; |
| } |
| |
| static int check_x_access(const char *path, int *ret_fd) { |
| _cleanup_close_ int fd = -EBADF; |
| int r; |
| |
| /* We need to use O_PATH because there may be executables for which we have only exec |
| * permissions, but not read (usually suid executables). */ |
| fd = open(path, O_PATH|O_CLOEXEC); |
| if (fd < 0) |
| return -errno; |
| |
| r = fd_verify_regular(fd); |
| if (r < 0) |
| return r; |
| |
| r = access_fd(fd, X_OK); |
| if (r == -ENOSYS) { |
| /* /proc is not mounted. Fallback to access(). */ |
| if (access(path, X_OK) < 0) |
| return -errno; |
| } else if (r < 0) |
| return r; |
| |
| if (ret_fd) |
| *ret_fd = TAKE_FD(fd); |
| |
| return 0; |
| } |
| |
| static int find_executable_impl(const char *name, const char *root, char **ret_filename, int *ret_fd) { |
| _cleanup_close_ int fd = -EBADF; |
| _cleanup_free_ char *path_name = NULL; |
| int r; |
| |
| assert(name); |
| |
| /* Function chase_symlinks() is invoked only when root is not NULL, as using it regardless of |
| * root value would alter the behavior of existing callers for example: /bin/sleep would become |
| * /usr/bin/sleep when find_executables is called. Hence, this function should be invoked when |
| * needed to avoid unforeseen regression or other complicated changes. */ |
| if (root) { |
| r = chase_symlinks(name, |
| root, |
| CHASE_PREFIX_ROOT, |
| &path_name, |
| /* ret_fd= */ NULL); /* prefix root to name in case full paths are not specified */ |
| if (r < 0) |
| return r; |
| |
| name = path_name; |
| } |
| |
| r = check_x_access(name, ret_fd ? &fd : NULL); |
| if (r < 0) |
| return r; |
| |
| if (ret_filename) { |
| r = path_make_absolute_cwd(name, ret_filename); |
| if (r < 0) |
| return r; |
| } |
| |
| if (ret_fd) |
| *ret_fd = TAKE_FD(fd); |
| |
| return 0; |
| } |
| |
| int find_executable_full(const char *name, const char *root, char **exec_search_path, bool use_path_envvar, char **ret_filename, int *ret_fd) { |
| int last_error = -ENOENT, r = 0; |
| const char *p = NULL; |
| |
| assert(name); |
| |
| if (is_path(name)) |
| return find_executable_impl(name, root, ret_filename, ret_fd); |
| |
| if (use_path_envvar) |
| /* Plain getenv, not secure_getenv, because we want to actually allow the user to pick the |
| * binary. */ |
| p = getenv("PATH"); |
| if (!p) |
| p = DEFAULT_PATH; |
| |
| if (exec_search_path) { |
| STRV_FOREACH(element, exec_search_path) { |
| _cleanup_free_ char *full_path = NULL; |
| |
| if (!path_is_absolute(*element)) |
| continue; |
| |
| full_path = path_join(*element, name); |
| if (!full_path) |
| return -ENOMEM; |
| |
| r = find_executable_impl(full_path, root, ret_filename, ret_fd); |
| if (r < 0) { |
| if (r != -EACCES) |
| last_error = r; |
| continue; |
| } |
| return 0; |
| } |
| return last_error; |
| } |
| |
| /* Resolve a single-component name to a full path */ |
| for (;;) { |
| _cleanup_free_ char *element = NULL; |
| |
| r = extract_first_word(&p, &element, ":", EXTRACT_RELAX|EXTRACT_DONT_COALESCE_SEPARATORS); |
| if (r < 0) |
| return r; |
| if (r == 0) |
| break; |
| |
| if (!path_is_absolute(element)) |
| continue; |
| |
| if (!path_extend(&element, name)) |
| return -ENOMEM; |
| |
| r = find_executable_impl(element, root, ret_filename, ret_fd); |
| if (r < 0) { |
| /* PATH entries which we don't have access to are ignored, as per tradition. */ |
| if (r != -EACCES) |
| last_error = r; |
| continue; |
| } |
| |
| /* Found it! */ |
| return 0; |
| } |
| |
| return last_error; |
| } |
| |
| bool paths_check_timestamp(const char* const* paths, usec_t *timestamp, bool update) { |
| bool changed = false, originally_unset; |
| |
| assert(timestamp); |
| |
| if (!paths) |
| return false; |
| |
| originally_unset = *timestamp == 0; |
| |
| STRV_FOREACH(i, paths) { |
| struct stat stats; |
| usec_t u; |
| |
| if (stat(*i, &stats) < 0) |
| continue; |
| |
| u = timespec_load(&stats.st_mtim); |
| |
| /* check first */ |
| if (*timestamp >= u) |
| continue; |
| |
| log_debug(originally_unset ? "Loaded timestamp for '%s'." : "Timestamp of '%s' changed.", *i); |
| |
| /* update timestamp */ |
| if (update) { |
| *timestamp = u; |
| changed = true; |
| } else |
| return true; |
| } |
| |
| return changed; |
| } |
| |
| static int executable_is_good(const char *executable) { |
| _cleanup_free_ char *p = NULL, *d = NULL; |
| int r; |
| |
| r = find_executable(executable, &p); |
| if (r == -ENOENT) |
| return 0; |
| if (r < 0) |
| return r; |
| |
| /* An fsck that is linked to /bin/true is a non-existent fsck */ |
| |
| r = readlink_malloc(p, &d); |
| if (r == -EINVAL) /* not a symlink */ |
| return 1; |
| if (r < 0) |
| return r; |
| |
| return !PATH_IN_SET(d, "true" |
| "/bin/true", |
| "/usr/bin/true", |
| "/dev/null"); |
| } |
| |
| int fsck_exists(void) { |
| return executable_is_good("fsck"); |
| } |
| |
| int fsck_exists_for_fstype(const char *fstype) { |
| const char *checker; |
| int r; |
| |
| assert(fstype); |
| |
| if (streq(fstype, "auto")) |
| return -EINVAL; |
| |
| r = fsck_exists(); |
| if (r <= 0) |
| return r; |
| |
| checker = strjoina("fsck.", fstype); |
| return executable_is_good(checker); |
| } |
| |
| static const char *skip_slash_or_dot(const char *p) { |
| for (; !isempty(p); p++) { |
| if (*p == '/') |
| continue; |
| if (startswith(p, "./")) { |
| p++; |
| continue; |
| } |
| break; |
| } |
| return p; |
| } |
| |
| int path_find_first_component(const char **p, bool accept_dot_dot, const char **ret) { |
| const char *q, *first, *end_first, *next; |
| size_t len; |
| |
| assert(p); |
| |
| /* When a path is input, then returns the pointer to the first component and its length, and |
| * move the input pointer to the next component or nul. This skips both over any '/' |
| * immediately *before* and *after* the first component before returning. |
| * |
| * Examples |
| * Input: p: "//.//aaa///bbbbb/cc" |
| * Output: p: "bbbbb///cc" |
| * ret: "aaa///bbbbb/cc" |
| * return value: 3 (== strlen("aaa")) |
| * |
| * Input: p: "aaa//" |
| * Output: p: (pointer to NUL) |
| * ret: "aaa//" |
| * return value: 3 (== strlen("aaa")) |
| * |
| * Input: p: "/", ".", "" |
| * Output: p: (pointer to NUL) |
| * ret: NULL |
| * return value: 0 |
| * |
| * Input: p: NULL |
| * Output: p: NULL |
| * ret: NULL |
| * return value: 0 |
| * |
| * Input: p: "(too long component)" |
| * Output: return value: -EINVAL |
| * |
| * (when accept_dot_dot is false) |
| * Input: p: "//..//aaa///bbbbb/cc" |
| * Output: return value: -EINVAL |
| */ |
| |
| q = *p; |
| |
| first = skip_slash_or_dot(q); |
| if (isempty(first)) { |
| *p = first; |
| if (ret) |
| *ret = NULL; |
| return 0; |
| } |
| if (streq(first, ".")) { |
| *p = first + 1; |
| if (ret) |
| *ret = NULL; |
| return 0; |
| } |
| |
| end_first = strchrnul(first, '/'); |
| len = end_first - first; |
| |
| if (len > NAME_MAX) |
| return -EINVAL; |
| if (!accept_dot_dot && len == 2 && first[0] == '.' && first[1] == '.') |
| return -EINVAL; |
| |
| next = skip_slash_or_dot(end_first); |
| |
| *p = next + streq(next, "."); |
| if (ret) |
| *ret = first; |
| return len; |
| } |
| |
| static const char *skip_slash_or_dot_backward(const char *path, const char *q) { |
| assert(path); |
| assert(!q || q >= path); |
| |
| for (; q; q = PTR_SUB1(q, path)) { |
| if (*q == '/') |
| continue; |
| if (q > path && strneq(q - 1, "/.", 2)) |
| continue; |
| break; |
| } |
| return q; |
| } |
| |
| int path_find_last_component(const char *path, bool accept_dot_dot, const char **next, const char **ret) { |
| const char *q, *last_end, *last_begin; |
| size_t len; |
| |
| /* Similar to path_find_first_component(), but search components from the end. |
| * |
| * Examples |
| * Input: path: "//.//aaa///bbbbb/cc//././" |
| * next: NULL |
| * Output: next: "/cc//././" |
| * ret: "cc//././" |
| * return value: 2 (== strlen("cc")) |
| * |
| * Input: path: "//.//aaa///bbbbb/cc//././" |
| * next: "/cc//././" |
| * Output: next: "///bbbbb/cc//././" |
| * ret: "bbbbb/cc//././" |
| * return value: 5 (== strlen("bbbbb")) |
| * |
| * Input: path: "/", ".", "", or NULL |
| * Output: next: equivalent to path |
| * ret: NULL |
| * return value: 0 |
| * |
| * Input: path: "(too long component)" |
| * Output: return value: -EINVAL |
| * |
| * (when accept_dot_dot is false) |
| * Input: path: "//..//aaa///bbbbb/cc/..//" |
| * Output: return value: -EINVAL |
| */ |
| |
| if (isempty(path)) { |
| if (next) |
| *next = path; |
| if (ret) |
| *ret = NULL; |
| return 0; |
| } |
| |
| if (next && *next) { |
| if (*next < path || *next > path + strlen(path)) |
| return -EINVAL; |
| if (*next == path) { |
| if (ret) |
| *ret = NULL; |
| return 0; |
| } |
| if (!IN_SET(**next, '\0', '/')) |
| return -EINVAL; |
| q = *next - 1; |
| } else |
| q = path + strlen(path) - 1; |
| |
| q = skip_slash_or_dot_backward(path, q); |
| if (!q || /* the root directory */ |
| (q == path && *q == '.')) { /* path is "." or "./" */ |
| if (next) |
| *next = path; |
| if (ret) |
| *ret = NULL; |
| return 0; |
| } |
| |
| last_end = q + 1; |
| |
| while (q && *q != '/') |
| q = PTR_SUB1(q, path); |
| |
| last_begin = q ? q + 1 : path; |
| len = last_end - last_begin; |
| |
| if (len > NAME_MAX) |
| return -EINVAL; |
| if (!accept_dot_dot && len == 2 && strneq(last_begin, "..", 2)) |
| return -EINVAL; |
| |
| if (next) { |
| q = skip_slash_or_dot_backward(path, q); |
| *next = q ? q + 1 : path; |
| } |
| |
| if (ret) |
| *ret = last_begin; |
| return len; |
| } |
| |
| const char *last_path_component(const char *path) { |
| |
| /* Finds the last component of the path, preserving the optional trailing slash that signifies a directory. |
| * |
| * a/b/c → c |
| * a/b/c/ → c/ |
| * x → x |
| * x/ → x/ |
| * /y → y |
| * /y/ → y/ |
| * / → / |
| * // → / |
| * /foo/a → a |
| * /foo/a/ → a/ |
| * |
| * Also, the empty string is mapped to itself. |
| * |
| * This is different than basename(), which returns "" when a trailing slash is present. |
| * |
| * This always succeeds (except if you pass NULL in which case it returns NULL, too). |
| */ |
| |
| unsigned l, k; |
| |
| if (!path) |
| return NULL; |
| |
| l = k = strlen(path); |
| if (l == 0) /* special case — an empty string */ |
| return path; |
| |
| while (k > 0 && path[k-1] == '/') |
| k--; |
| |
| if (k == 0) /* the root directory */ |
| return path + l - 1; |
| |
| while (k > 0 && path[k-1] != '/') |
| k--; |
| |
| return path + k; |
| } |
| |
| int path_extract_filename(const char *path, char **ret) { |
| _cleanup_free_ char *a = NULL; |
| const char *c, *next = NULL; |
| int r; |
| |
| /* Extracts the filename part (i.e. right-most component) from a path, i.e. string that passes |
| * filename_is_valid(). A wrapper around last_path_component(), but eats up trailing |
| * slashes. Returns: |
| * |
| * -EINVAL → if the path is not valid |
| * -EADDRNOTAVAIL → if only a directory was specified, but no filename, i.e. the root dir |
| * itself or "." is specified |
| * -ENOMEM → no memory |
| * |
| * Returns >= 0 on success. If the input path has a trailing slash, returns O_DIRECTORY, to |
| * indicate the referenced file must be a directory. |
| * |
| * This function guarantees to return a fully valid filename, i.e. one that passes |
| * filename_is_valid() – this means "." and ".." are not accepted. */ |
| |
| if (!path_is_valid(path)) |
| return -EINVAL; |
| |
| r = path_find_last_component(path, false, &next, &c); |
| if (r < 0) |
| return r; |
| if (r == 0) /* root directory */ |
| return -EADDRNOTAVAIL; |
| |
| a = strndup(c, r); |
| if (!a) |
| return -ENOMEM; |
| |
| *ret = TAKE_PTR(a); |
| return strlen(c) > (size_t) r ? O_DIRECTORY : 0; |
| } |
| |
| int path_extract_directory(const char *path, char **ret) { |
| _cleanup_free_ char *a = NULL; |
| const char *c, *next = NULL; |
| int r; |
| |
| /* The inverse of path_extract_filename(), i.e. returns the directory path prefix. Returns: |
| * |
| * -EINVAL → if the path is not valid |
| * -EDESTADDRREQ → if no directory was specified in the passed in path, i.e. only a filename was passed |
| * -EADDRNOTAVAIL → if the passed in parameter had no filename but did have a directory, i.e. |
| * the root dir itself or "." was specified |
| * -ENOMEM → no memory (surprise!) |
| * |
| * This function guarantees to return a fully valid path, i.e. one that passes path_is_valid(). |
| */ |
| |
| r = path_find_last_component(path, false, &next, &c); |
| if (r < 0) |
| return r; |
| if (r == 0) /* empty or root */ |
| return isempty(path) ? -EINVAL : -EADDRNOTAVAIL; |
| if (next == path) { |
| if (*path != '/') /* filename only */ |
| return -EDESTADDRREQ; |
| |
| a = strdup("/"); |
| if (!a) |
| return -ENOMEM; |
| *ret = TAKE_PTR(a); |
| return 0; |
| } |
| |
| a = strndup(path, next - path); |
| if (!a) |
| return -ENOMEM; |
| |
| path_simplify(a); |
| |
| if (!path_is_valid(a)) |
| return -EINVAL; |
| |
| *ret = TAKE_PTR(a); |
| return 0; |
| } |
| |
| bool filename_is_valid(const char *p) { |
| const char *e; |
| |
| if (isempty(p)) |
| return false; |
| |
| if (dot_or_dot_dot(p)) /* Yes, in this context we consider "." and ".." invalid */ |
| return false; |
| |
| e = strchrnul(p, '/'); |
| if (*e != 0) |
| return false; |
| |
| if (e - p > NAME_MAX) /* NAME_MAX is counted *without* the trailing NUL byte */ |
| return false; |
| |
| return true; |
| } |
| |
| bool path_is_valid_full(const char *p, bool accept_dot_dot) { |
| if (isempty(p)) |
| return false; |
| |
| for (const char *e = p;;) { |
| int r; |
| |
| r = path_find_first_component(&e, accept_dot_dot, NULL); |
| if (r < 0) |
| return false; |
| |
| if (e - p >= PATH_MAX) /* Already reached the maximum length for a path? (PATH_MAX is counted |
| * *with* the trailing NUL byte) */ |
| return false; |
| if (*e == 0) /* End of string? Yay! */ |
| return true; |
| } |
| } |
| |
| bool path_is_normalized(const char *p) { |
| if (!path_is_safe(p)) |
| return false; |
| |
| if (streq(p, ".") || startswith(p, "./") || endswith(p, "/.") || strstr(p, "/./")) |
| return false; |
| |
| if (strstr(p, "//")) |
| return false; |
| |
| return true; |
| } |
| |
| int file_in_same_dir(const char *path, const char *filename, char **ret) { |
| _cleanup_free_ char *b = NULL; |
| int r; |
| |
| assert(path); |
| assert(filename); |
| assert(ret); |
| |
| /* This removes the last component of path and appends filename, unless the latter is absolute anyway |
| * or the former isn't */ |
| |
| if (path_is_absolute(filename)) |
| b = strdup(filename); |
| else { |
| _cleanup_free_ char *dn = NULL; |
| |
| r = path_extract_directory(path, &dn); |
| if (r == -EDESTADDRREQ) /* no path prefix */ |
| b = strdup(filename); |
| else if (r < 0) |
| return r; |
| else |
| b = path_join(dn, filename); |
| } |
| if (!b) |
| return -ENOMEM; |
| |
| *ret = TAKE_PTR(b); |
| return 0; |
| } |
| |
| bool hidden_or_backup_file(const char *filename) { |
| assert(filename); |
| |
| if (filename[0] == '.' || |
| STR_IN_SET(filename, |
| "lost+found", |
| "aquota.user", |
| "aquota.group") || |
| endswith(filename, "~")) |
| return true; |
| |
| const char *dot = strrchr(filename, '.'); |
| if (!dot) |
| return false; |
| |
| /* Please, let's not add more entries to the list below. If external projects think it's a good idea |
| * to come up with always new suffixes and that everybody else should just adjust to that, then it |
| * really should be on them. Hence, in future, let's not add any more entries. Instead, let's ask |
| * those packages to instead adopt one of the generic suffixes/prefixes for hidden files or backups, |
| * possibly augmented with an additional string. Specifically: there's now: |
| * |
| * The generic suffixes "~" and ".bak" for backup files |
| * The generic prefix "." for hidden files |
| * |
| * Thus, if a new package manager "foopkg" wants its own set of ".foopkg-new", ".foopkg-old", |
| * ".foopkg-dist" or so registered, let's refuse that and ask them to use ".foopkg.new", |
| * ".foopkg.old" or ".foopkg~" instead. |
| */ |
| |
| return STR_IN_SET(dot + 1, |
| "rpmnew", |
| "rpmsave", |
| "rpmorig", |
| "dpkg-old", |
| "dpkg-new", |
| "dpkg-tmp", |
| "dpkg-dist", |
| "dpkg-bak", |
| "dpkg-backup", |
| "dpkg-remove", |
| "ucf-new", |
| "ucf-old", |
| "ucf-dist", |
| "swp", |
| "bak", |
| "old", |
| "new"); |
| } |
| |
| bool is_device_path(const char *path) { |
| |
| /* Returns true for paths that likely refer to a device, either by path in sysfs or to something in |
| * /dev. */ |
| |
| return PATH_STARTSWITH_SET(path, "/dev/", "/sys/"); |
| } |
| |
| bool valid_device_node_path(const char *path) { |
| |
| /* Some superficial checks whether the specified path is a valid device node path, all without |
| * looking at the actual device node. */ |
| |
| if (!PATH_STARTSWITH_SET(path, "/dev/", "/run/systemd/inaccessible/")) |
| return false; |
| |
| if (endswith(path, "/")) /* can't be a device node if it ends in a slash */ |
| return false; |
| |
| return path_is_normalized(path); |
| } |
| |
| bool valid_device_allow_pattern(const char *path) { |
| assert(path); |
| |
| /* Like valid_device_node_path(), but also allows full-subsystem expressions like those accepted by |
| * DeviceAllow= and DeviceDeny=. */ |
| |
| if (STARTSWITH_SET(path, "block-", "char-")) |
| return true; |
| |
| return valid_device_node_path(path); |
| } |
| |
| bool dot_or_dot_dot(const char *path) { |
| if (!path) |
| return false; |
| if (path[0] != '.') |
| return false; |
| if (path[1] == 0) |
| return true; |
| if (path[1] != '.') |
| return false; |
| |
| return path[2] == 0; |
| } |
| |
| bool empty_or_root(const char *path) { |
| |
| /* For operations relative to some root directory, returns true if the specified root directory is |
| * redundant, i.e. either / or NULL or the empty string or any equivalent. */ |
| |
| if (isempty(path)) |
| return true; |
| |
| return path_equal(path, "/"); |
| } |
| |
| bool path_strv_contains(char **l, const char *path) { |
| STRV_FOREACH(i, l) |
| if (path_equal(*i, path)) |
| return true; |
| |
| return false; |
| } |
| |
| bool prefixed_path_strv_contains(char **l, const char *path) { |
| STRV_FOREACH(i, l) { |
| const char *j = *i; |
| |
| if (*j == '-') |
| j++; |
| if (*j == '+') |
| j++; |
| if (path_equal(j, path)) |
| return true; |
| } |
| |
| return false; |
| } |
| |
| int path_glob_can_match(const char *pattern, const char *prefix, char **ret) { |
| assert(pattern); |
| assert(prefix); |
| |
| for (const char *a = pattern, *b = prefix;;) { |
| _cleanup_free_ char *g = NULL, *h = NULL; |
| const char *p, *q; |
| int r, s; |
| |
| r = path_find_first_component(&a, /* accept_dot_dot = */ false, &p); |
| if (r < 0) |
| return r; |
| |
| s = path_find_first_component(&b, /* accept_dot_dot = */ false, &q); |
| if (s < 0) |
| return s; |
| |
| if (s == 0) { |
| /* The pattern matches the prefix. */ |
| if (ret) { |
| char *t; |
| |
| t = path_join(prefix, p); |
| if (!t) |
| return -ENOMEM; |
| |
| *ret = t; |
| } |
| return true; |
| } |
| |
| if (r == 0) |
| break; |
| |
| if (r == s && strneq(p, q, r)) |
| continue; /* common component. Check next. */ |
| |
| g = strndup(p, r); |
| if (!g) |
| return -ENOMEM; |
| |
| if (!string_is_glob(g)) |
| break; |
| |
| /* We found a glob component. Check if the glob pattern matches the prefix component. */ |
| |
| h = strndup(q, s); |
| if (!h) |
| return -ENOMEM; |
| |
| r = fnmatch(g, h, 0); |
| if (r == FNM_NOMATCH) |
| break; |
| if (r != 0) /* Failure to process pattern? */ |
| return -EINVAL; |
| } |
| |
| /* The pattern does not match the prefix. */ |
| if (ret) |
| *ret = NULL; |
| return false; |
| } |
