systemd: merge branch systemd into master

config.h.meson

@@ -25,6 +25,10 @@
 /* Gettext package */
 #mesondefine GETTEXT_PACKAGE
 
+/* Define to 1 if you have the declaration of `reallocarray', and to 0 if
+   you don't. */
+#mesondefine HAVE_DECL_REALLOCARRAY
+
 /* Define to 1 if you have the declaration of `explicit_bzero', and to 0 if
    you don't. */
 #mesondefine HAVE_DECL_EXPLICIT_BZERO

configure.ac

@@ -75,6 +75,12 @@ AC_CHECK_DECLS([
 #include <string.h>
 ]])
 
+AC_CHECK_DECLS([
+	reallocarray],
+	[], [], [[
+#include <malloc.h>
+]])
+
 AC_CHECK_HEADERS(sys/auxv.h)
 
 AC_CHECK_DECLS([getrandom],

meson.build

@@ -97,22 +97,23 @@ endforeach
 # headers
 config_h.set10('HAVE_SYS_AUXV_H', cc.has_header('sys/auxv.h'))
 
-use_sys_random = cc.has_function('getrandom', prefix: '#include<sys/random.h>')
+use_sys_random = cc.has_function('getrandom', prefix: '#include <sys/random.h>')
 config_h.set10('USE_SYS_RANDOM_H', use_sys_random)
-config_h.set10('HAVE_GETRANDOM', use_sys_random or cc.has_function('getrandom', prefix: '#include<linux/random.h>'))
+config_h.set10('HAVE_GETRANDOM', use_sys_random or cc.has_function('getrandom', prefix: '#include <linux/random.h>'))
 
 # functions
 # FIXME secure_getenv check is not useful?
 config_h.set('HAVE_SECURE_GETENV', cc.has_function('secure_getenv'))
 config_h.set('HAVE___SECURE_GETENV', cc.has_function('__secure_getenv'))
-config_h.set10('HAVE_DECL_EXPLICIT_BZERO', cc.has_function('explicit_bzero', prefix: '#include<string.h>'))
+config_h.set10('HAVE_DECL_REALLOCARRAY', cc.has_function('reallocarray', prefix: '#include <malloc.h>'))
+config_h.set10('HAVE_DECL_EXPLICIT_BZERO', cc.has_function('explicit_bzero', prefix: '#include <string.h>'))
 
 # types
-config_h.set('SIZEOF_DEV_T', cc.sizeof('dev_t', prefix: '#include<sys/types.h>'))
-config_h.set('SIZEOF_TIME_T', cc.sizeof('time_t', prefix: '#include<sys/types.h>'))
-config_h.set('SIZEOF_PID_T', cc.sizeof('pid_t', prefix: '#include<sys/types.h>'))
+config_h.set('SIZEOF_DEV_T', cc.sizeof('dev_t', prefix: '#include <sys/types.h>'))
+config_h.set('SIZEOF_TIME_T', cc.sizeof('time_t', prefix: '#include <sys/types.h>'))
+config_h.set('SIZEOF_PID_T', cc.sizeof('pid_t', prefix: '#include <sys/types.h>'))
 
-if not cc.has_type('pid_t', prefix: '#include<sys/types.h>')
+if not cc.has_type('pid_t', prefix: '#include <sys/types.h>')
   config_h.set('pid_t', 'int')
 endif
 

src/systemd/sd-adapt/nm-sd-adapt.h

@@ -26,12 +26,16 @@
 #include <sys/resource.h>
 #include <time.h>
 
-#define noreturn G_GNUC_NORETURN
-
 #ifndef CLOCK_BOOTTIME
 #define CLOCK_BOOTTIME 7
 #endif
 
+#if defined(HAVE_DECL_REALLOCARRAY) && HAVE_DECL_REALLOCARRAY == 1
+#define HAVE_REALLOCARRAY 1
+#else
+#define HAVE_REALLOCARRAY 0
+#endif
+
 #if defined(HAVE_DECL_EXPLICIT_BZERO) && HAVE_DECL_EXPLICIT_BZERO == 1
 #define HAVE_EXPLICIT_BZERO 1
 #else

src/systemd/src/basic/alloc-util.h

@@ -74,12 +74,14 @@ _malloc_  _alloc_(1, 2) static inline void *malloc_multiply(size_t size, size_t
         return malloc(size * need);
 }
 
-_alloc_(2, 3) static inline void *realloc_multiply(void *p, size_t size, size_t need) {
+#if !HAVE_REALLOCARRAY
+_alloc_(2, 3) static inline void *reallocarray(void *p, size_t need, size_t size) {
         if (size_multiply_overflow(size, need))
                 return NULL;
 
         return realloc(p, size * need);
 }
+#endif
 
 _alloc_(2, 3) static inline void *memdup_multiply(const void *p, size_t size, size_t need) {
         if (size_multiply_overflow(size, need))
@@ -128,3 +130,12 @@ void* greedy_realloc0(void **p, size_t *allocated, size_t need, size_t size);
                 _new_ = alloca_align(_size_, (align));                  \
                 (void*)memset(_new_, 0, _size_);                        \
         })
+
+/* Takes inspiration from Rusts's Option::take() method: reads and returns a pointer, but at the same time resets it to
+ * NULL. See: https://doc.rust-lang.org/std/option/enum.Option.html#method.take */
+#define TAKE_PTR(ptr)                           \
+        ({                                      \
+                typeof(ptr) _ptr_ = (ptr);      \
+                (ptr) = NULL;                   \
+                _ptr_;                          \
+        })

src/systemd/src/basic/extract-word.c

@@ -196,8 +196,7 @@ finish:
 
 finish_force_next:
         s[sz] = 0;
-        *ret = s;
-        s = NULL;
+        *ret = TAKE_PTR(s);
 
         return 1;
 }

src/systemd/src/basic/fd-util.c

@@ -194,12 +194,6 @@ int fd_cloexec(int fd, bool cloexec) {
 }
 
 #if 0 /* NM_IGNORED */
-void stdio_unset_cloexec(void) {
-        (void) fd_cloexec(STDIN_FILENO, false);
-        (void) fd_cloexec(STDOUT_FILENO, false);
-        (void) fd_cloexec(STDERR_FILENO, false);
-}
-
 _pure_ static bool fd_in_set(int fd, const int fdset[], unsigned n_fdset) {
         unsigned i;
 
@@ -371,14 +365,21 @@ bool fdname_is_valid(const char *s) {
 }
 
 int fd_get_path(int fd, char **ret) {
-        char procfs_path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int)];
+        _cleanup_close_ int dir = -1;
+        char fdname[DECIMAL_STR_MAX(int)];
         int r;
 
-        xsprintf(procfs_path, "/proc/self/fd/%i", fd);
+        dir = open("/proc/self/fd/", O_CLOEXEC | O_DIRECTORY | O_PATH);
+        if (dir < 0)
+                /* /proc is not available or not set up properly, we're most likely
+                 * in some chroot environment. */
+                return errno == ENOENT ? -EOPNOTSUPP : -errno;
 
-        r = readlink_malloc(procfs_path, ret);
+        xsprintf(fdname, "%i", fd);
 
-        if (r == -ENOENT) /* If the file doesn't exist the fd is invalid */
+        r = readlinkat_malloc(dir, fdname, ret);
+        if (r == -ENOENT)
+                /* If the file doesn't exist the fd is invalid */
                 return -EBADF;
 
         return r;
@@ -431,7 +432,6 @@ int move_fd(int from, int to, int cloexec) {
 
 int acquire_data_fd(const void *data, size_t size, unsigned flags) {
 
-        char procfs_path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int)];
         _cleanup_close_pair_ int pipefds[2] = { -1, -1 };
         char pattern[] = "/dev/shm/data-fd-XXXXXX";
         _cleanup_close_ int fd = -1;
@@ -488,10 +488,7 @@ int acquire_data_fd(const void *data, size_t size, unsigned flags) {
                 if (r < 0)
                         return r;
 
-                r = fd;
-                fd = -1;
-
-                return r;
+                return TAKE_FD(fd);
         }
 
 try_pipe:
@@ -528,10 +525,7 @@ try_pipe:
 
                 (void) fd_nonblock(pipefds[0], false);
 
-                r = pipefds[0];
-                pipefds[0] = -1;
-
-                return r;
+                return TAKE_FD(pipefds[0]);
         }
 
 try_dev_shm:
@@ -547,12 +541,7 @@ try_dev_shm:
                         return -EIO;
 
                 /* Let's reopen the thing, in order to get an O_RDONLY fd for the original O_RDWR one */
-                xsprintf(procfs_path, "/proc/self/fd/%i", fd);
-                r = open(procfs_path, O_RDONLY|O_CLOEXEC);
-                if (r < 0)
-                        return -errno;
-
-                return r;
+                return fd_reopen(fd, O_RDONLY|O_CLOEXEC);
         }
 
 try_dev_shm_without_o_tmpfile:
@@ -621,3 +610,139 @@ int fd_move_above_stdio(int fd) {
         (void) close(fd);
         return copy;
 }
+
+#if 0 /* NM_IGNORED */
+int rearrange_stdio(int original_input_fd, int original_output_fd, int original_error_fd) {
+
+        int fd[3] = { /* Put together an array of fds we work on */
+                original_input_fd,
+                original_output_fd,
+                original_error_fd
+        };
+
+        int r, i,
+                null_fd = -1,                /* if we open /dev/null, we store the fd to it here */
+                copy_fd[3] = { -1, -1, -1 }; /* This contains all fds we duplicate here temporarily, and hence need to close at the end */
+        bool null_readable, null_writable;
+
+        /* Sets up stdin, stdout, stderr with the three file descriptors passed in. If any of the descriptors is
+         * specified as -1 it will be connected with /dev/null instead. If any of the file descriptors is passed as
+         * itself (e.g. stdin as STDIN_FILENO) it is left unmodified, but the O_CLOEXEC bit is turned off should it be
+         * on.
+         *
+         * Note that if any of the passed file descriptors are > 2 they will be closed — both on success and on
+         * failure! Thus, callers should assume that when this function returns the input fds are invalidated.
+         *
+         * Note that when this function fails stdin/stdout/stderr might remain half set up!
+         *
+         * O_CLOEXEC is turned off for all three file descriptors (which is how it should be for
+         * stdin/stdout/stderr). */
+
+        null_readable = original_input_fd < 0;
+        null_writable = original_output_fd < 0 || original_error_fd < 0;
+
+        /* First step, open /dev/null once, if we need it */
+        if (null_readable || null_writable) {
+
+                /* Let's open this with O_CLOEXEC first, and convert it to non-O_CLOEXEC when we move the fd to the final position. */
+                null_fd = open("/dev/null", (null_readable && null_writable ? O_RDWR :
+                                             null_readable ? O_RDONLY : O_WRONLY) | O_CLOEXEC);
+                if (null_fd < 0) {
+                        r = -errno;
+                        goto finish;
+                }
+
+                /* If this fd is in the 0…2 range, let's move it out of it */
+                if (null_fd < 3) {
+                        int copy;
+
+                        copy = fcntl(null_fd, F_DUPFD_CLOEXEC, 3); /* Duplicate this with O_CLOEXEC set */
+                        if (copy < 0) {
+                                r = -errno;
+                                goto finish;
+                        }
+
+                        safe_close(null_fd);
+                        null_fd = copy;
+                }
+        }
+
+        /* Let's assemble fd[] with the fds to install in place of stdin/stdout/stderr */
+        for (i = 0; i < 3; i++) {
+
+                if (fd[i] < 0)
+                        fd[i] = null_fd;        /* A negative parameter means: connect this one to /dev/null */
+                else if (fd[i] != i && fd[i] < 3) {
+                        /* This fd is in the 0…2 territory, but not at its intended place, move it out of there, so that we can work there. */
+                        copy_fd[i] = fcntl(fd[i], F_DUPFD_CLOEXEC, 3); /* Duplicate this with O_CLOEXEC set */
+                        if (copy_fd[i] < 0) {
+                                r = -errno;
+                                goto finish;
+                        }
+
+                        fd[i] = copy_fd[i];
+                }
+        }
+
+        /* At this point we now have the fds to use in fd[], and they are all above the stdio range, so that we
+         * have freedom to move them around. If the fds already were at the right places then the specific fds are
+         * -1. Let's now move them to the right places. This is the point of no return. */
+        for (i = 0; i < 3; i++) {
+
+                if (fd[i] == i) {
+
+                        /* fd is already in place, but let's make sure O_CLOEXEC is off */
+                        r = fd_cloexec(i, false);
+                        if (r < 0)
+                                goto finish;
+
+                } else {
+                        assert(fd[i] > 2);
+
+                        if (dup2(fd[i], i) < 0) { /* Turns off O_CLOEXEC on the new fd. */
+                                r = -errno;
+                                goto finish;
+                        }
+                }
+        }
+
+        r = 0;
+
+finish:
+        /* Close the original fds, but only if they were outside of the stdio range. Also, properly check for the same
+         * fd passed in multiple times. */
+        safe_close_above_stdio(original_input_fd);
+        if (original_output_fd != original_input_fd)
+                safe_close_above_stdio(original_output_fd);
+        if (original_error_fd != original_input_fd && original_error_fd != original_output_fd)
+                safe_close_above_stdio(original_error_fd);
+
+        /* Close the copies we moved > 2 */
+        for (i = 0; i < 3; i++)
+                safe_close(copy_fd[i]);
+
+        /* Close our null fd, if it's > 2 */
+        safe_close_above_stdio(null_fd);
+
+        return r;
+}
+
+int fd_reopen(int fd, int flags) {
+        char procfs_path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int)];
+        int new_fd;
+
+        /* Reopens the specified fd with new flags. This is useful for convert an O_PATH fd into a regular one, or to
+         * turn O_RDWR fds into O_RDONLY fds.
+         *
+         * This doesn't work on sockets (since they cannot be open()ed, ever).
+         *
+         * This implicitly resets the file read index to 0. */
+
+        xsprintf(procfs_path, "/proc/self/fd/%i", fd);
+        new_fd = open(procfs_path, flags);
+        if (new_fd < 0)
+                return -errno;
+
+        return new_fd;
+}
+#endif /* NM_IGNORED */

src/systemd/src/basic/fd-util.h

@@ -35,6 +35,13 @@ int close_nointr(int fd);
 int safe_close(int fd);
 void safe_close_pair(int p[]);
 
+static inline int safe_close_above_stdio(int fd) {
+        if (fd < 3) /* Don't close stdin/stdout/stderr, but still invalidate the fd by returning -1 */
+                return -1;
+
+        return safe_close(fd);
+}
+
 void close_many(const int fds[], unsigned n_fd);
 
 int fclose_nointr(FILE *f);
@@ -64,7 +71,6 @@ DEFINE_TRIVIAL_CLEANUP_FUNC(DIR*, closedir);
 
 int fd_nonblock(int fd, bool nonblock);
 int fd_cloexec(int fd, bool cloexec);
-void stdio_unset_cloexec(void);
 
 int close_all_fds(const int except[], unsigned n_except);
 
@@ -93,3 +99,19 @@ int acquire_data_fd(const void *data, size_t size, unsigned flags);
         IN_SET(r, ENOTCONN, ECONNRESET, ECONNREFUSED, ECONNABORTED, EPIPE, ENETUNREACH)
 
 int fd_move_above_stdio(int fd);
+
+int rearrange_stdio(int original_input_fd, int original_output_fd, int original_error_fd);
+
+static inline int make_null_stdio(void) {
+        return rearrange_stdio(-1, -1, -1);
+}
+
+/* Like TAKE_PTR() but for file descriptors, resetting them to -1 */
+#define TAKE_FD(fd)                             \
+        ({                                      \
+                int _fd_ = (fd);                \
+                (fd) = -1;                      \
+                _fd_;                           \
+        })
+
+int fd_reopen(int fd, int flags);

src/systemd/src/basic/fileio.c

@@ -334,8 +334,7 @@ int read_full_stream(FILE *f, char **contents, size_t *size) {
         }
 
         buf[l] = 0;
-        *contents = buf;
-        buf = NULL; /* do not free */
+        *contents = TAKE_PTR(buf);
 
         if (size)
                 *size = l;
@@ -367,11 +366,11 @@ static int parse_env_file_internal(
                 void *userdata,
                 int *n_pushed) {
 
-        _cleanup_free_ char *contents = NULL, *key = NULL;
         size_t key_alloc = 0, n_key = 0, value_alloc = 0, n_value = 0, last_value_whitespace = (size_t) -1, last_key_whitespace = (size_t) -1;
-        char *p, *value = NULL;
-        int r;
+        _cleanup_free_ char *contents = NULL, *key = NULL, *value = NULL;
         unsigned line = 1;
+        char *p;
+        int r;
 
         enum {
                 PRE_KEY,
@@ -408,10 +407,8 @@ static int parse_env_file_internal(
                                 state = KEY;
                                 last_key_whitespace = (size_t) -1;
 
-                                if (!GREEDY_REALLOC(key, key_alloc, n_key+2)) {
-                                        r = -ENOMEM;
-                                        goto fail;
-                                }
+                                if (!GREEDY_REALLOC(key, key_alloc, n_key+2))
+                                        return -ENOMEM;
 
                                 key[n_key++] = c;
                         }
@@ -431,10 +428,8 @@ static int parse_env_file_internal(
                                 else if (last_key_whitespace == (size_t) -1)
                                          last_key_whitespace = n_key;
 
-                                if (!GREEDY_REALLOC(key, key_alloc, n_key+2)) {
-                                        r = -ENOMEM;
-                                        goto fail;
-                                }
+                                if (!GREEDY_REALLOC(key, key_alloc, n_key+2))
+                                        return -ENOMEM;
 
                                 key[n_key++] = c;
                         }
@@ -456,7 +451,7 @@ static int parse_env_file_internal(
 
                                 r = push(fname, line, key, value, userdata, n_pushed);
                                 if (r < 0)
-                                        goto fail;
+                                        return r;
 
                                 n_key = 0;
                                 value = NULL;
@@ -471,10 +466,8 @@ static int parse_env_file_internal(
                         else if (!strchr(WHITESPACE, c)) {
                                 state = VALUE;
 
-                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2)) {
-                                        r = -ENOMEM;
-                                        goto fail;
-                                }
+                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2))
+                                        return  -ENOMEM;
 
                                 value[n_value++] = c;
                         }
@@ -501,7 +494,7 @@ static int parse_env_file_internal(
 
                                 r = push(fname, line, key, value, userdata, n_pushed);
                                 if (r < 0)
-                                        goto fail;
+                                        return r;
 
                                 n_key = 0;
                                 value = NULL;
@@ -516,10 +509,8 @@ static int parse_env_file_internal(
                                 else if (last_value_whitespace == (size_t) -1)
                                         last_value_whitespace = n_value;
 
-                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2)) {
-                                        r = -ENOMEM;
-                                        goto fail;
-                                }
+                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2))
+                                        return -ENOMEM;
 
                                 value[n_value++] = c;
                         }
@@ -531,10 +522,8 @@ static int parse_env_file_internal(
 
                         if (!strchr(newline, c)) {
                                 /* Escaped newlines we eat up entirely */
-                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2)) {
-                                        r = -ENOMEM;
-                                        goto fail;
-                                }
+                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2))
+                                        return -ENOMEM;
 
                                 value[n_value++] = c;
                         }
@@ -546,10 +535,8 @@ static int parse_env_file_internal(
                         else if (c == '\\')
                                 state = SINGLE_QUOTE_VALUE_ESCAPE;
                         else {
-                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2)) {
-                                        r = -ENOMEM;
-                                        goto fail;
-                                }
+                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2))
+                                        return -ENOMEM;
 
                                 value[n_value++] = c;
                         }
@@ -560,10 +547,8 @@ static int parse_env_file_internal(
                         state = SINGLE_QUOTE_VALUE;
 
                         if (!strchr(newline, c)) {
-                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2)) {
-                                        r = -ENOMEM;
-                                        goto fail;
-                                }
+                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2))
+                                        return -ENOMEM;
 
                                 value[n_value++] = c;
                         }
@@ -575,10 +560,8 @@ static int parse_env_file_internal(
                         else if (c == '\\')
                                 state = DOUBLE_QUOTE_VALUE_ESCAPE;
                         else {
-                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2)) {
-                                        r = -ENOMEM;
-                                        goto fail;
-                                }
+                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2))
+                                        return -ENOMEM;
 
                                 value[n_value++] = c;
                         }
@@ -589,10 +572,8 @@ static int parse_env_file_internal(
                         state = DOUBLE_QUOTE_VALUE;
 
                         if (!strchr(newline, c)) {
-                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2)) {
-                                        r = -ENOMEM;
-                                        goto fail;
-                                }
+                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2))
+                                        return -ENOMEM;
 
                                 value[n_value++] = c;
                         }
@@ -637,14 +618,12 @@ static int parse_env_file_internal(
 
                 r = push(fname, line, key, value, userdata, n_pushed);
                 if (r < 0)
-                        goto fail;
+                        return r;
+
+                value = NULL;
         }
 
         return 0;
-
-fail:
-        free(value);
-        return r;
 }
 
 static int check_utf8ness_and_warn(
@@ -1465,8 +1444,7 @@ int open_tmpfile_linkable(const char *target, int flags, char **ret_path) {
         if (fd < 0)
                 return -errno;
 
-        *ret_path = tmp;
-        tmp = NULL;
+        *ret_path = TAKE_PTR(tmp);
 
         return fd;
 }
@@ -1552,8 +1530,7 @@ int read_nul_string(FILE *f, char **ret) {
                         return -ENOMEM;
         }
 
-        *ret = x;
-        x = NULL;
+        *ret = TAKE_PTR(x);
 
         return 0;
 }

src/systemd/src/basic/fs-util.c

@@ -465,10 +465,8 @@ int get_files_in_directory(const char *path, char ***list) {
                         n++;
         }
 
-        if (list) {
-                *list = l;
-                l = NULL; /* avoid freeing */
-        }
+        if (list)
+                *list = TAKE_PTR(l);
 
         return n;
 }
@@ -586,6 +584,10 @@ int inotify_add_watch_fd(int fd, int what, uint32_t mask) {
         return r;
 }
 
+static bool noop_root(const char *root) {
+        return isempty(root) || path_equal(root, "/");
+}
+
 static bool safe_transition(const struct stat *a, const struct stat *b) {
         /* Returns true if the transition from a to b is safe, i.e. that we never transition from unprivileged to
          * privileged files or directories. Why bother? So that unprivileged code can't symlink to privileged files
@@ -636,9 +638,19 @@ int chase_symlinks(const char *path, const char *original_root, unsigned flags,
          * specified path. */
 
         /* A root directory of "/" or "" is identical to none */
-        if (isempty(original_root) || path_equal(original_root, "/"))
+        if (noop_root(original_root))
                 original_root = NULL;
 
+        if (!original_root && !ret && (flags & (CHASE_NONEXISTENT|CHASE_NO_AUTOFS|CHASE_SAFE|CHASE_OPEN)) == CHASE_OPEN) {
+                /* Shortcut the CHASE_OPEN case if the caller isn't interested in the actual path and has no root set
+                 * and doesn't care about any of the other special features we provide either. */
+                r = open(path, O_PATH|O_CLOEXEC);
+                if (r < 0)
+                        return -errno;
+
+                return r;
+        }
+
         if (original_root) {
                 r = path_make_absolute_cwd(original_root, &root);
                 if (r < 0)
@@ -692,8 +704,10 @@ int chase_symlinks(const char *path, const char *original_root, unsigned flags,
                 /* Just a single slash? Then we reached the end. */
                 if (path_equal(first, "/")) {
                         /* Preserve the trailing slash */
-                        if (!strextend(&done, "/", NULL))
-                                return -ENOMEM;
+
+                        if (flags & CHASE_TRAIL_SLASH)
+                                if (!strextend(&done, "/", NULL))
+                                        return -ENOMEM;
 
                         break;
                 }
@@ -739,8 +753,7 @@ int chase_symlinks(const char *path, const char *original_root, unsigned flags,
                         }
 
                         safe_close(fd);
-                        fd = fd_parent;
-                        fd_parent = -1;
+                        fd = TAKE_FD(fd_parent);
 
                         continue;
                 }
@@ -845,10 +858,9 @@ 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 = first;
-                        first = NULL;
-                } else {
+                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';
@@ -859,8 +871,7 @@ int chase_symlinks(const char *path, const char *original_root, unsigned flags,
 
                 /* And iterate again, but go one directory further down. */
                 safe_close(fd);
-                fd = child;
-                child = -1;
+                fd = TAKE_FD(child);
         }
 
         if (!done) {
@@ -870,27 +881,100 @@ int chase_symlinks(const char *path, const char *original_root, unsigned flags,
                         return -ENOMEM;
         }
 
-        if (ret) {
-                *ret = done;
-                done = NULL;
-        }
+        if (ret)
+                *ret = TAKE_PTR(done);
 
         if (flags & CHASE_OPEN) {
-                int q;
-
                 /* Return the O_PATH fd we currently are looking to the caller. It can translate it to a proper fd by
                  * opening /proc/self/fd/xyz. */
 
                 assert(fd >= 0);
-                q = fd;
-                fd = -1;
-
-                return q;
+                return TAKE_FD(fd);
         }
 
         return exists;
 }
 
+int chase_symlinks_and_open(
+                const char *path,
+                const char *root,
+                unsigned chase_flags,
+                int open_flags,
+                char **ret_path) {
+
+        _cleanup_close_ int path_fd = -1;
+        _cleanup_free_ char *p = NULL;
+        int r;
+
+        if (chase_flags & CHASE_NONEXISTENT)
+                return -EINVAL;
+
+        if (noop_root(root) && !ret_path && (chase_flags & (CHASE_NO_AUTOFS|CHASE_SAFE)) == 0) {
+                /* Shortcut this call if none of the special features of this call are requested */
+                r = open(path, open_flags);
+                if (r < 0)
+                        return -errno;
+
+                return r;
+        }
+
+        path_fd = chase_symlinks(path, root, chase_flags|CHASE_OPEN, ret_path ? &p : NULL);
+        if (path_fd < 0)
+                return path_fd;
+
+        r = fd_reopen(path_fd, open_flags);
+        if (r < 0)
+                return r;
+
+        if (ret_path)
+                *ret_path = TAKE_PTR(p);
+
+        return r;
+}
+
+int chase_symlinks_and_opendir(
+                const char *path,
+                const char *root,
+                unsigned chase_flags,
+                char **ret_path,
+                DIR **ret_dir) {
+
+        char procfs_path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int)];
+        _cleanup_close_ int path_fd = -1;
+        _cleanup_free_ char *p = NULL;
+        DIR *d;
+
+        if (!ret_dir)
+                return -EINVAL;
+        if (chase_flags & CHASE_NONEXISTENT)
+                return -EINVAL;
+
+        if (noop_root(root) && !ret_path && (chase_flags & (CHASE_NO_AUTOFS|CHASE_SAFE)) == 0) {
+                /* Shortcut this call if none of the special features of this call are requested */
+                d = opendir(path);