/* SPDX-License-Identifier: LGPL-2.1-or-later */ #include #include #include #include #include #include #include "alloc-util.h" #include "chase.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) { _cleanup_strv_free_ char **l = NULL; int r; assert(p); assert(ret); l = strv_split(p, ":"); if (!l) return -ENOMEM; r = path_strv_make_absolute_cwd(l); if (r < 0) return r; *ret = TAKE_PTR(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(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_inode_same(const char *a, const char *b, int flags) { return path_equal(a, b) || inode_same(a, b, flags) > 0; } int path_compare_filename(const char *a, const char *b) { _cleanup_free_ char *fa = NULL, *fb = NULL; int r, j, k; /* Order NULL before non-NULL */ r = CMP(!!a, !!b); if (r != 0) return r; j = path_extract_filename(a, &fa); k = path_extract_filename(b, &fb); /* When one of paths is "." or root, then order it earlier. */ r = CMP(j != -EADDRNOTAVAIL, k != -EADDRNOTAVAIL); if (r != 0) return r; /* When one of paths is invalid (or we get OOM), 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. */ if (j < 0) return strcmp(a, b); return strcmp(fa, fb); } 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() 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) { /* prefix root to name in case full paths are not specified */ r = chase(name, root, CHASE_PREFIX_ROOT, &path_name, /* ret_fd= */ NULL); 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; if (q == path && *q == '.') 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: "//.//aaa///bbbbb/cc//././" * next: "///bbbbb/cc//././" * Output: next: "//.//aaa///bbbbb/cc//././" (next == path) * ret: "aaa///bbbbb/cc//././" * return value: 3 (== strlen("aaa")) * * 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; }