Merge pull request #18834 from poettering/path-extract

Beef up path_extract_filename() a bit, and introduce path_extract_directory()

src/basic/locale-util.h

@@ -90,3 +90,7 @@ void locale_variables_free(char* l[_VARIABLE_LC_MAX]);
 static inline void locale_variables_freep(char*(*l)[_VARIABLE_LC_MAX]) {
         locale_variables_free(*l);
 }
+
+static inline const char *special_glyph_check_mark(bool b) {
+        return b ? special_glyph(SPECIAL_GLYPH_CHECK_MARK) : special_glyph(SPECIAL_GLYPH_CROSS_MARK);
+}

src/basic/path-util.c

@@ -819,11 +819,21 @@ const char *last_path_component(const char *path) {
 int path_extract_filename(const char *p, char **ret) {
         _cleanup_free_ char *a = NULL;
         const char *c;
+        size_t n;
 
         /* 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
+         * filename_is_valid(). A wrapper around last_path_component(), but eats up trailing
-         * -EADDRNOTAVAIL if specified parameter includes no filename (i.e. is "/" or so). Returns -EINVAL if
+         * slashes. Returns:
-         * not a valid path in the first place. */
+         *
+         * -EINVAL        → if the passed in path is not a valid path
+         * -EADDRNOTAVAIL → if only a directory was specified, but no filename, i.e. the root dir itself 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(p))
                 return -EINVAL;
@@ -834,14 +844,57 @@ int path_extract_filename(const char *p, char **ret) {
                 return -EADDRNOTAVAIL;
 
         c = last_path_component(p);
+        n = strcspn(c, "/");
 
-        a = strndup(c, strcspn(c, "/"));
+        a = strndup(c, n);
         if (!a)
                 return -ENOMEM;
 
         if (!filename_is_valid(a))
                 return -EINVAL;
 
+        *ret = TAKE_PTR(a);
+        return c[n] == '/' ? O_DIRECTORY : 0;
+}
+
+int path_extract_directory(const char *p, char **ret) {
+        _cleanup_free_ char *a = NULL;
+        const char *c;
+
+        /* The inverse of path_extract_filename(), i.e. returns the directory path prefix. Returns:
+         *
+         * -EINVAL        → if the passed in path is not a valid path
+         * -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 was specified
+         * -ENOMEM        → no memory (surprise!)
+         *
+         * This function guarantees to return a fully valid path, i.e. one that passes path_is_valid().
+         */
+
+        if (!path_is_valid(p))
+                return -EINVAL;
+
+        /* Special case the root dir, because otherwise for an input of "///" last_path_component() returns
+         * the pointer to the last slash only, which might be seen as a valid path below. */
+        if (path_equal(p, "/"))
+                return -EADDRNOTAVAIL;
+
+        c = last_path_component(p);
+
+        /* Delete trailing slashes, but keep one */
+        while (c > p+1 && c[-1] == '/')
+                c--;
+
+        if (p == c) /* No path whatsoever? Then return a recognizable error */
+                return -EDESTADDRREQ;
+
+        a = strndup(p, c - p);
+        if (!a)
+                return -ENOMEM;
+
+        if (!path_is_valid(a))
+                return -EINVAL;
+
         *ret = TAKE_PTR(a);
         return 0;
 }

src/basic/path-util.h

@@ -147,6 +147,7 @@ int fsck_exists(const char *fstype);
 char* dirname_malloc(const char *path);
 const char *last_path_component(const char *path);
 int path_extract_filename(const char *p, char **ret);
+int path_extract_directory(const char *p, char **ret);
 
 bool filename_is_valid(const char *p) _pure_;
 bool path_is_valid(const char *p) _pure_;

src/basic/terminal-util.h

@@ -253,5 +253,9 @@ int vt_release(int fd, bool restore_vt);
 
 void get_log_colors(int priority, const char **on, const char **off, const char **highlight);
 
+static inline const char* ansi_highlight_green_red(bool b) {
+        return b ? ansi_highlight_green() : ansi_highlight_red();
+}
+
 /* This assumes there is a 'tty' group */
 #define TTY_MODE 0620

src/basic/tmpfile-util.c

@@ -94,16 +94,11 @@ int fmkostemp_safe(char *pattern, const char *mode, FILE **ret_f) {
 }
 
 int tempfn_xxxxxx(const char *p, const char *extra, char **ret) {
-        const char *fn;
+        _cleanup_free_ char *d = NULL, *fn = NULL, *nf = NULL;
-        char *t;
+        int r;
 
         assert(ret);
 
-        if (isempty(p))
-                return -EINVAL;
-        if (path_equal(p, "/"))
-                return -EINVAL;
-
         /*
          * Turns this:
          *         /foo/bar/waldo
@@ -112,34 +107,41 @@ int tempfn_xxxxxx(const char *p, const char *extra, char **ret) {
          *         /foo/bar/.#<extra>waldoXXXXXX
          */
 
-        fn = basename(p);
+        r = path_extract_directory(p, &d);
-        if (!filename_is_valid(fn))
+        if (r < 0 && r != -EDESTADDRREQ) /* EDESTADDRREQ → No directory specified, just a filename */
-                return -EINVAL;
+                return r;
 
-        extra = strempty(extra);
+        r = path_extract_filename(p, &fn);
+        if (r < 0)
+                return r;
 
-        t = new(char, strlen(p) + 2 + strlen(extra) + 6 + 1);
+        nf = strjoin(".#", strempty(extra), fn, "XXXXXX");
-        if (!t)
+        if (!nf)
                 return -ENOMEM;
 
-        strcpy(stpcpy(stpcpy(stpcpy(mempcpy(t, p, fn - p), ".#"), extra), fn), "XXXXXX");
+        if (!filename_is_valid(nf)) /* New name is not valid? (Maybe because too long?) Refuse. */
+                return -EINVAL;
+
+        if (d)  {
+                char *j;
+
+                j = path_join(d, nf);
+                if (!j)
+                        return -ENOMEM;
+
+                *ret = path_simplify(j, false);
+        } else
+                *ret = TAKE_PTR(nf);
 
-        *ret = path_simplify(t, false);
         return 0;
 }
 
 int tempfn_random(const char *p, const char *extra, char **ret) {
-        const char *fn;
+        _cleanup_free_ char *d = NULL, *fn = NULL, *nf = NULL;
-        char *t, *x;
+        int r;
-        uint64_t u;
 
         assert(ret);
 
-        if (isempty(p))
-                return -EINVAL;
-        if (path_equal(p, "/"))
-                return -EINVAL;
-
         /*
          * Turns this:
          *         /foo/bar/waldo
@@ -148,27 +150,34 @@ int tempfn_random(const char *p, const char *extra, char **ret) {
          *         /foo/bar/.#<extra>waldobaa2a261115984a9
          */
 
-        fn = basename(p);
+        r = path_extract_directory(p, &d);
-        if (!filename_is_valid(fn))
+        if (r < 0 && r != -EDESTADDRREQ) /* EDESTADDRREQ → No directory specified, just a filename */
-                return -EINVAL;
+                return r;
 
-        extra = strempty(extra);
+        r = path_extract_filename(p, &fn);
+        if (r < 0)
+                return r;
 
-        t = new(char, strlen(p) + 2 + strlen(extra) + 16 + 1);
+        if (asprintf(&nf, ".#%s%s%016" PRIx64,
-        if (!t)
+                     strempty(extra),
+                     fn,
+                     random_u64()) < 0)
                 return -ENOMEM;
 
-        x = stpcpy(stpcpy(stpcpy(mempcpy(t, p, fn - p), ".#"), extra), fn);
+        if (!filename_is_valid(nf)) /* Not valid? (maybe because too long now?) — refuse early */
+                return -EINVAL;
 
-        u = random_u64();
+        if (d) {
-        for (unsigned i = 0; i < 16; i++) {
+                char *j;
-                *(x++) = hexchar(u & 0xF);
-                u >>= 4;
-        }
 
-        *x = 0;
+                j = path_join(d, nf);
+                if (!j)
+                        return -ENOMEM;
+
+                *ret = path_simplify(j, false);
+        } else
+                *ret = TAKE_PTR(nf);
 
-        *ret = path_simplify(t, false);
         return 0;
 }
 

src/boot/bootctl.c

@@ -1153,8 +1153,8 @@ static void read_loader_efi_var(const char *name, char **var) {
 static void print_yes_no_line(bool first, bool good, const char *name) {
         printf("%s%s%s%s %s\n",
                first ? "     Features: " : "               ",
-               good ? ansi_highlight_green() : ansi_highlight_red(),
+               ansi_highlight_green_red(good),
-               good ? special_glyph(SPECIAL_GLYPH_CHECK_MARK) : special_glyph(SPECIAL_GLYPH_CROSS_MARK),
+               special_glyph_check_mark(good),
                ansi_normal(),
                name);
 }

src/machine/machinectl.c

@@ -1872,6 +1872,9 @@ static int import_tar(int argc, char *argv[], void *userdata) {
                 r = path_extract_filename(path, &fn);
                 if (r < 0)
                         return log_error_errno(r, "Cannot extract container name from filename: %m");
+                if (r == O_DIRECTORY)
+                        return log_error_errno(SYNTHETIC_ERRNO(EISDIR),
+                                               "Path '%s' refers to directory, but we need a regular file: %m", path);
 
                 local = fn;
         }
@@ -1932,6 +1935,9 @@ static int import_raw(int argc, char *argv[], void *userdata) {
                 r = path_extract_filename(path, &fn);
                 if (r < 0)
                         return log_error_errno(r, "Cannot extract container name from filename: %m");
+                if (r == O_DIRECTORY)
+                        return log_error_errno(SYNTHETIC_ERRNO(EISDIR),
+                                               "Path '%s' refers to directory, but we need a regular file: %m", path);
 
                 local = fn;
         }

src/test/meson.build

@@ -379,6 +379,8 @@ tests += [
 
         [['src/test/test-clock.c']],
 
+        [['src/test/test-tmpfile-util.c']],
+
         [['src/test/test-architecture.c']],
 
         [['src/test/test-log.c']],

src/test/test-path-util.c

@@ -570,7 +570,10 @@ static void test_path_extract_filename_one(const char *input, const char *output
         int r;
 
         r = path_extract_filename(input, &k);
-        log_info("%s → %s/%s [expected: %s/%s]", strnull(input), strnull(k), strerror_safe(r), strnull(output), strerror_safe(ret));
+        log_info_errno(r, "%s → %s/%m [expected: %s/%s]",
+                       strnull(input),
+                       strnull(k), /* strerror(r) is printed via %m, to avoid that the two strerror()'s overwrite each other's buffers */
+                       strnull(output), ret < 0 ? strerror_safe(ret) : "-");
         assert_se(streq_ptr(k, output));
         assert_se(r == ret);
 }
@@ -580,7 +583,7 @@ static void test_path_extract_filename(void) {
 
         test_path_extract_filename_one(NULL, NULL, -EINVAL);
         test_path_extract_filename_one("a/b/c", "c", 0);
-        test_path_extract_filename_one("a/b/c/", "c", 0);
+        test_path_extract_filename_one("a/b/c/", "c", O_DIRECTORY);
         test_path_extract_filename_one("/", NULL, -EADDRNOTAVAIL);
         test_path_extract_filename_one("//", NULL, -EADDRNOTAVAIL);
         test_path_extract_filename_one("///", NULL, -EADDRNOTAVAIL);
@@ -589,13 +592,13 @@ static void test_path_extract_filename(void) {
         test_path_extract_filename_one("././", NULL, -EINVAL);
         test_path_extract_filename_one("././/", NULL, -EINVAL);
         test_path_extract_filename_one("/foo/a", "a", 0);
-        test_path_extract_filename_one("/foo/a/", "a", 0);
+        test_path_extract_filename_one("/foo/a/", "a", O_DIRECTORY);
         test_path_extract_filename_one("", NULL, -EINVAL);
         test_path_extract_filename_one("a", "a", 0);
-        test_path_extract_filename_one("a/", "a", 0);
+        test_path_extract_filename_one("a/", "a", O_DIRECTORY);
         test_path_extract_filename_one("/a", "a", 0);
-        test_path_extract_filename_one("/a/", "a", 0);
+        test_path_extract_filename_one("/a/", "a", O_DIRECTORY);
-        test_path_extract_filename_one("/////////////a/////////////", "a", 0);
+        test_path_extract_filename_one("/////////////a/////////////", "a", O_DIRECTORY);
         test_path_extract_filename_one("xx/.", NULL, -EINVAL);
         test_path_extract_filename_one("xx/..", NULL, -EINVAL);
         test_path_extract_filename_one("..", NULL, -EINVAL);
@@ -606,6 +609,64 @@ static void test_path_extract_filename(void) {
         test_path_extract_filename_one("./", NULL, -EINVAL);
 }
 
+static void test_path_extract_directory_one(const char *input, const char *output, int ret) {
+        _cleanup_free_ char *k = NULL;
+        int r;
+
+        r = path_extract_directory(input, &k);
+        log_info_errno(r, "%s → %s/%m [expected: %s/%s]",
+                       strnull(input),
+                       strnull(k), /* we output strerror_safe(r) via %m here, since otherwise the error buffer might be overwritten twice */
+                       strnull(output), strerror_safe(ret));
+        assert_se(streq_ptr(k, output));
+        assert_se(r == ret);
+
+        /* Extra safety check: let's make sure that if we split out the filename too (and it works) the
+         * joined parts are identical to the original again */
+        if (r >= 0) {
+                _cleanup_free_ char *f = NULL;
+
+                r = path_extract_filename(input, &f);
+                if (r >= 0) {
+                        _cleanup_free_ char *j = NULL;
+
+                        assert_se(j = path_join(k, f));
+                        assert_se(path_equal(input, j));
+                }
+        }
+}
+
+static void test_path_extract_directory(void) {
+        log_info("/* %s */", __func__);
+
+        test_path_extract_directory_one(NULL, NULL, -EINVAL);
+        test_path_extract_directory_one("a/b/c", "a/b", 0);
+        test_path_extract_directory_one("a/b/c/", "a/b", 0);
+        test_path_extract_directory_one("/", NULL, -EADDRNOTAVAIL);
+        test_path_extract_directory_one("//", NULL, -EADDRNOTAVAIL);
+        test_path_extract_directory_one("///", NULL, -EADDRNOTAVAIL);
+        test_path_extract_directory_one(".", NULL, -EDESTADDRREQ);
+        test_path_extract_directory_one("./.", ".", 0);
+        test_path_extract_directory_one("././", ".", 0);
+        test_path_extract_directory_one("././/", ".", 0);
+        test_path_extract_directory_one("/foo/a", "/foo", 0);
+        test_path_extract_directory_one("/foo/a/", "/foo", 0);
+        test_path_extract_directory_one("", NULL, -EINVAL);
+        test_path_extract_directory_one("a", NULL, -EDESTADDRREQ);
+        test_path_extract_directory_one("a/", NULL, -EDESTADDRREQ);
+        test_path_extract_directory_one("/a", "/", 0);
+        test_path_extract_directory_one("/a/", "/", 0);
+        test_path_extract_directory_one("/////////////a/////////////", "/", 0);
+        test_path_extract_directory_one("xx/.", "xx", 0);
+        test_path_extract_directory_one("xx/..", "xx", 0);
+        test_path_extract_directory_one("..", NULL, -EDESTADDRREQ);
+        test_path_extract_directory_one("/..", "/", 0);
+        test_path_extract_directory_one("../", NULL, -EDESTADDRREQ);
+        test_path_extract_directory_one(".", NULL, -EDESTADDRREQ);
+        test_path_extract_directory_one("/.", "/", 0);
+        test_path_extract_directory_one("./", NULL, -EDESTADDRREQ);
+}
+
 static void test_filename_is_valid(void) {
         char foo[NAME_MAX+2];
 
@@ -793,6 +854,7 @@ int main(int argc, char **argv) {
         test_file_in_same_dir();
         test_last_path_component();
         test_path_extract_filename();
+        test_path_extract_directory();
         test_filename_is_valid();
         test_path_is_valid();
         test_hidden_or_backup_file();

src/test/test-tmpfile-util.c

@@ -0,0 +1,102 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "alloc-util.h"
+#include "errno-util.h"
+#include "log.h"
+#include "string-util.h"
+#include "tests.h"
+#include "tmpfile-util.h"
+
+static void test_tempfn_random_one(const char *p, const char *extra, const char *expect, int ret) {
+        _cleanup_free_ char *s = NULL;
+        int r;
+
+        r = tempfn_random(p, extra, &s);
+        log_info_errno(r, "%s+%s → %s vs. %s (%i/%m vs. %i/%s)", p, strna(extra), strna(s), strna(expect), r, ret, strerror_safe(ret));
+
+        assert(!s == !expect);
+        if (s) {
+                const char *suffix;
+
+                assert_se(suffix = startswith(s, expect));
+                assert_se(in_charset(suffix, HEXDIGITS));
+                assert_se(strlen(suffix) == 16);
+        }
+        assert(ret == r);
+}
+
+static void test_tempfn_random(void) {
+        test_tempfn_random_one("", NULL, NULL, -EINVAL);
+        test_tempfn_random_one(".", NULL, NULL, -EINVAL);
+        test_tempfn_random_one("..", NULL, NULL, -EINVAL);
+        test_tempfn_random_one("/", NULL, NULL, -EADDRNOTAVAIL);
+
+        test_tempfn_random_one("foo", NULL, ".#foo", 0);
+        test_tempfn_random_one("foo", "bar", ".#barfoo", 0);
+        test_tempfn_random_one("/tmp/foo", NULL, "/tmp/.#foo", 0);
+        test_tempfn_random_one("/tmp/foo", "bar", "/tmp/.#barfoo", 0);
+        test_tempfn_random_one("./foo", NULL, "./.#foo", 0);
+        test_tempfn_random_one("./foo", "bar", "./.#barfoo", 0);
+        test_tempfn_random_one("../foo", NULL, "../.#foo", 0);
+        test_tempfn_random_one("../foo", "bar", "../.#barfoo", 0);
+
+        test_tempfn_random_one("foo/", NULL, ".#foo", 0);
+        test_tempfn_random_one("foo/", "bar", ".#barfoo", 0);
+        test_tempfn_random_one("/tmp/foo/", NULL, "/tmp/.#foo", 0);
+        test_tempfn_random_one("/tmp/foo/", "bar", "/tmp/.#barfoo", 0);
+        test_tempfn_random_one("./foo/", NULL, "./.#foo", 0);
+        test_tempfn_random_one("./foo/", "bar", "./.#barfoo", 0);
+        test_tempfn_random_one("../foo/", NULL, "../.#foo", 0);
+        test_tempfn_random_one("../foo/", "bar", "../.#barfoo", 0);
+}
+
+static void test_tempfn_xxxxxx_one(const char *p, const char *extra, const char *expect, int ret) {
+        _cleanup_free_ char *s = NULL;
+        int r;
+
+        r = tempfn_xxxxxx(p, extra, &s);
+        log_info_errno(r, "%s+%s → %s vs. %s (%i/%m vs. %i/%s)", p, strna(extra), strna(s), strna(expect), r, ret, strerror_safe(ret));
+
+        assert(!s == !expect);
+        if (s) {
+                const char *suffix;
+
+                assert_se(suffix = startswith(s, expect));
+                assert_se(streq(suffix, "XXXXXX"));
+        }
+        assert(ret == r);
+}
+
+static void test_tempfn_xxxxxx(void) {
+        test_tempfn_xxxxxx_one("", NULL, NULL, -EINVAL);
+        test_tempfn_xxxxxx_one(".", NULL, NULL, -EINVAL);
+        test_tempfn_xxxxxx_one("..", NULL, NULL, -EINVAL);
+        test_tempfn_xxxxxx_one("/", NULL, NULL, -EADDRNOTAVAIL);
+
+        test_tempfn_xxxxxx_one("foo", NULL, ".#foo", 0);
+        test_tempfn_xxxxxx_one("foo", "bar", ".#barfoo", 0);
+        test_tempfn_xxxxxx_one("/tmp/foo", NULL, "/tmp/.#foo", 0);
+        test_tempfn_xxxxxx_one("/tmp/foo", "bar", "/tmp/.#barfoo", 0);
+        test_tempfn_xxxxxx_one("./foo", NULL, "./.#foo", 0);
+        test_tempfn_xxxxxx_one("./foo", "bar", "./.#barfoo", 0);
+        test_tempfn_xxxxxx_one("../foo", NULL, "../.#foo", 0);
+        test_tempfn_xxxxxx_one("../foo", "bar", "../.#barfoo", 0);
+
+        test_tempfn_xxxxxx_one("foo/", NULL, ".#foo", 0);
+        test_tempfn_xxxxxx_one("foo/", "bar", ".#barfoo", 0);
+        test_tempfn_xxxxxx_one("/tmp/foo/", NULL, "/tmp/.#foo", 0);
+        test_tempfn_xxxxxx_one("/tmp/foo/", "bar", "/tmp/.#barfoo", 0);
+        test_tempfn_xxxxxx_one("./foo/", NULL, "./.#foo", 0);
+        test_tempfn_xxxxxx_one("./foo/", "bar", "./.#barfoo", 0);
+        test_tempfn_xxxxxx_one("../foo/", NULL, "../.#foo", 0);
+        test_tempfn_xxxxxx_one("../foo/", "bar", "../.#barfoo", 0);
+}
+
+int main(int argc, char **argv) {
+        test_setup_logging(LOG_DEBUG);
+
+        test_tempfn_random();
+        test_tempfn_xxxxxx();
+
+        return 0;
+}