chiark / gitweb /
util: rework rm_rf() logic
[elogind.git] / src / shared / util.c
index dc6528013bb0a7fded44e17a9e84e3eb5473b9f8..973f1070b8a1178ee4796a03ecdca2872f3cf5af 100644 (file)
@@ -19,7 +19,6 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
-#include <assert.h>
 #include <string.h>
 #include <unistd.h>
 #include <errno.h>
@@ -48,7 +47,6 @@
 #include <pwd.h>
 #include <netinet/ip.h>
 #include <linux/kd.h>
-#include <dlfcn.h>
 #include <sys/wait.h>
 #include <sys/time.h>
 #include <glob.h>
@@ -83,7 +81,6 @@
 #include "missing.h"
 #include "log.h"
 #include "strv.h"
-#include "label.h"
 #include "mkdir.h"
 #include "path-util.h"
 #include "exit-status.h"
@@ -97,6 +94,9 @@
 #include "def.h"
 #include "sparse-endian.h"
 
+/* Put this test here for a lack of better place */
+assert_cc(EAGAIN == EWOULDBLOCK);
+
 int saved_argc = 0;
 char **saved_argv = NULL;
 
@@ -151,6 +151,27 @@ char* endswith(const char *s, const char *postfix) {
         return (char*) s + sl - pl;
 }
 
+char* endswith_no_case(const char *s, const char *postfix) {
+        size_t sl, pl;
+
+        assert(s);
+        assert(postfix);
+
+        sl = strlen(s);
+        pl = strlen(postfix);
+
+        if (pl == 0)
+                return (char*) s + sl;
+
+        if (sl < pl)
+                return NULL;
+
+        if (strcasecmp(s + sl - pl, postfix) != 0)
+                return NULL;
+
+        return (char*) s + sl - pl;
+}
+
 char* first_word(const char *s, const char *word) {
         size_t sl, wl;
         const char *p;
@@ -1347,6 +1368,125 @@ char *cescape(const char *s) {
         return r;
 }
 
+static int cunescape_one(const char *p, size_t length, char *ret) {
+        int r = 1;
+
+        assert(p);
+        assert(*p);
+        assert(ret);
+
+        if (length != (size_t) -1 && length < 1)
+                return -EINVAL;
+
+        switch (p[0]) {
+
+        case 'a':
+                *ret = '\a';
+                break;
+        case 'b':
+                *ret = '\b';
+                break;
+        case 'f':
+                *ret = '\f';
+                break;
+        case 'n':
+                *ret = '\n';
+                break;
+        case 'r':
+                *ret = '\r';
+                break;
+        case 't':
+                *ret = '\t';
+                break;
+        case 'v':
+                *ret = '\v';
+                break;
+        case '\\':
+                *ret = '\\';
+                break;
+        case '"':
+                *ret = '"';
+                break;
+        case '\'':
+                *ret = '\'';
+                break;
+
+        case 's':
+                /* This is an extension of the XDG syntax files */
+                *ret = ' ';
+                break;
+
+        case 'x': {
+                /* hexadecimal encoding */
+                int a, b;
+
+                if (length != (size_t) -1 && length < 3)
+                        return -EINVAL;
+
+                a = unhexchar(p[1]);
+                if (a < 0)
+                        return -EINVAL;
+
+                b = unhexchar(p[2]);
+                if (b < 0)
+                        return -EINVAL;
+
+                /* don't allow NUL bytes */
+                if (a == 0 && b == 0)
+                        return -EINVAL;
+
+                *ret = (char) ((a << 4) | b);
+                r = 3;
+                break;
+        }
+
+        case '0':
+        case '1':
+        case '2':
+        case '3':
+        case '4':
+        case '5':
+        case '6':
+        case '7': {
+                /* octal encoding */
+                int a, b, c, m;
+
+                if (length != (size_t) -1 && length < 4)
+                        return -EINVAL;
+
+                a = unoctchar(p[0]);
+                if (a < 0)
+                        return -EINVAL;
+
+                b = unoctchar(p[1]);
+                if (b < 0)
+                        return -EINVAL;
+
+                c = unoctchar(p[2]);
+                if (c < 0)
+                        return -EINVAL;
+
+                /* don't allow NUL bytes */
+                if (a == 0 && b == 0 && c == 0)
+                        return -EINVAL;
+
+                /* Don't allow bytes above 255 */
+                m = (a << 6) | (b << 3) | c;
+                if (m > 255)
+                        return -EINVAL;
+
+                *ret = (char) m;
+                r = 3;
+                break;
+        }
+
+        default:
+                return -EINVAL;
+        }
+
+        return r;
+}
+
 char *cunescape_length_with_prefix(const char *s, size_t length, const char *prefix) {
         char *r, *t;
         const char *f;
@@ -1366,115 +1506,27 @@ char *cunescape_length_with_prefix(const char *s, size_t length, const char *pre
                 memcpy(r, prefix, pl);
 
         for (f = s, t = r + pl; f < s + length; f++) {
-                size_t remaining = s + length - f;
+                size_t remaining;
+                int k;
+
+                remaining = s + length - f;
                 assert(remaining > 0);
 
-                if (*f != '\\') {        /* a literal literal */
+                if (*f != '\\' || remaining == 1) {
+                        /* a literal literal, or a trailing backslash, copy verbatim */
                         *(t++) = *f;
                         continue;
                 }
 
-                if (--remaining == 0) {  /* copy trailing backslash verbatim */
-                        *(t++) = *f;
-                        break;
-                }
-
-                f++;
-
-                switch (*f) {
-
-                case 'a':
-                        *(t++) = '\a';
-                        break;
-                case 'b':
-                        *(t++) = '\b';
-                        break;
-                case 'f':
-                        *(t++) = '\f';
-                        break;
-                case 'n':
-                        *(t++) = '\n';
-                        break;
-                case 'r':
-                        *(t++) = '\r';
-                        break;
-                case 't':
-                        *(t++) = '\t';
-                        break;
-                case 'v':
-                        *(t++) = '\v';
-                        break;
-                case '\\':
-                        *(t++) = '\\';
-                        break;
-                case '"':
-                        *(t++) = '"';
-                        break;
-                case '\'':
-                        *(t++) = '\'';
-                        break;
-
-                case 's':
-                        /* This is an extension of the XDG syntax files */
-                        *(t++) = ' ';
-                        break;
-
-                case 'x': {
-                        /* hexadecimal encoding */
-                        int a = -1, b = -1;
-
-                        if (remaining >= 2) {
-                                a = unhexchar(f[1]);
-                                b = unhexchar(f[2]);
-                        }
-
-                        if (a < 0 || b < 0 || (a == 0 && b == 0)) {
-                                /* Invalid escape code, let's take it literal then */
-                                *(t++) = '\\';
-                                *(t++) = 'x';
-                        } else {
-                                *(t++) = (char) ((a << 4) | b);
-                                f += 2;
-                        }
-
-                        break;
-                }
-
-                case '0':
-                case '1':
-                case '2':
-                case '3':
-                case '4':
-                case '5':
-                case '6':
-                case '7': {
-                        /* octal encoding */
-                        int a = -1, b = -1, c = -1;
-
-                        if (remaining >= 3) {
-                                a = unoctchar(f[0]);
-                                b = unoctchar(f[1]);
-                                c = unoctchar(f[2]);
-                        }
-
-                        if (a < 0 || b < 0 || c < 0 || (a == 0 && b == 0 && c == 0)) {
-                                /* Invalid escape code, let's take it literal then */
-                                *(t++) = '\\';
-                                *(t++) = f[0];
-                        } else {
-                                *(t++) = (char) ((a << 6) | (b << 3) | c);
-                                f += 2;
-                        }
-
-                        break;
-                }
-
-                default:
+                k = cunescape_one(f + 1, remaining - 1, t);
+                if (k < 0) {
                         /* Invalid escape code, let's take it literal then */
                         *(t++) = '\\';
-                        *(t++) = *f;
-                        break;
+                        continue;
                 }
+
+                f += k;
+                t++;
         }
 
         *t = 0;
@@ -1692,6 +1744,7 @@ bool chars_intersect(const char *a, const char *b) {
 
 bool fstype_is_network(const char *fstype) {
         static const char table[] =
+                "afs\0"
                 "cifs\0"
                 "smbfs\0"
                 "sshfs\0"
@@ -2328,6 +2381,17 @@ ssize_t loop_read(int fd, void *buf, size_t nbytes, bool do_poll) {
         return n;
 }
 
+int loop_read_exact(int fd, void *buf, size_t nbytes, bool do_poll) {
+        ssize_t n;
+
+        n = loop_read(fd, buf, nbytes, do_poll);
+        if (n < 0)
+                return n;
+        if ((size_t) n != nbytes)
+                return -EIO;
+        return 0;
+}
+
 int loop_write(int fd, const void *buf, size_t nbytes, bool do_poll) {
         const uint8_t *p = buf;
 
@@ -2582,8 +2646,9 @@ char* dirname_malloc(const char *path) {
 
 int dev_urandom(void *p, size_t n) {
         static int have_syscall = -1;
-        int r, fd;
-        ssize_t k;
+
+        _cleanup_close_ int fd = -1;
+        int r;
 
         /* Gathers some randomness from the kernel. This call will
          * never block, and will always return some data from the
@@ -2618,22 +2683,14 @@ int dev_urandom(void *p, size_t n) {
                                 return -errno;
                 } else
                         /* too short read? */
-                        return -EIO;
+                        return -ENODATA;
         }
 
         fd = open("/dev/urandom", O_RDONLY|O_CLOEXEC|O_NOCTTY);
         if (fd < 0)
                 return errno == ENOENT ? -ENOSYS : -errno;
 
-        k = loop_read(fd, p, n, true);
-        safe_close(fd);
-
-        if (k < 0)
-                return (int) k;
-        if ((size_t) k != n)
-                return -EIO;
-
-        return 0;
+        return loop_read_exact(fd, p, n, true);
 }
 
 void initialize_srand(void) {
@@ -2846,7 +2903,7 @@ int getttyname_malloc(int fd, char **ret) {
 
 int getttyname_harder(int fd, char **r) {
         int k;
-        char *s;
+        char *s = NULL;
 
         k = getttyname_malloc(fd, &s);
         if (k < 0)
@@ -2921,31 +2978,30 @@ int get_ctty(pid_t pid, dev_t *_devnr, char **r) {
 
                 /* This is an ugly hack */
                 if (major(devnr) == 136) {
-                        asprintf(&b, "pts/%u", minor(devnr));
-                        goto finish;
-                }
+                        if (asprintf(&b, "pts/%u", minor(devnr)) < 0)
+                                return -ENOMEM;
+                } else {
+                        /* Probably something like the ptys which have no
+                         * symlink in /dev/char. Let's return something
+                         * vaguely useful. */
 
-                /* Probably something like the ptys which have no
-                 * symlink in /dev/char. Let's return something
-                 * vaguely useful. */
+                        b = strdup(fn + 5);
+                        if (!b)
+                                return -ENOMEM;
+                }
+        } else {
+                if (startswith(s, "/dev/"))
+                        p = s + 5;
+                else if (startswith(s, "../"))
+                        p = s + 3;
+                else
+                        p = s;
 
-                b = strdup(fn + 5);
-                goto finish;
+                b = strdup(p);
+                if (!b)
+                        return -ENOMEM;
         }
 
-        if (startswith(s, "/dev/"))
-                p = s + 5;
-        else if (startswith(s, "../"))
-                p = s + 3;
-        else
-                p = s;
-
-        b = strdup(p);
-
-finish:
-        if (!b)
-                return -ENOMEM;
-
         *r = b;
         if (_devnr)
                 *_devnr = devnr;
@@ -2953,101 +3009,14 @@ finish:
         return 0;
 }
 
-int rm_rf_children_dangerous(int fd, bool only_dirs, bool honour_sticky, struct stat *root_dev) {
-        _cleanup_closedir_ DIR *d = NULL;
-        int ret = 0;
-
-        assert(fd >= 0);
-
-        /* This returns the first error we run into, but nevertheless
-         * tries to go on. This closes the passed fd. */
-
-        d = fdopendir(fd);
-        if (!d) {
-                safe_close(fd);
-
-                return errno == ENOENT ? 0 : -errno;
-        }
-
-        for (;;) {
-                struct dirent *de;
-                bool is_dir, keep_around;
-                struct stat st;
-                int r;
-
-                errno = 0;
-                de = readdir(d);
-                if (!de) {
-                        if (errno != 0 && ret == 0)
-                                ret = -errno;
-                        return ret;
-                }
-
-                if (streq(de->d_name, ".") || streq(de->d_name, ".."))
-                        continue;
-
-                if (de->d_type == DT_UNKNOWN ||
-                    honour_sticky ||
-                    (de->d_type == DT_DIR && root_dev)) {
-                        if (fstatat(fd, de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0) {
-                                if (ret == 0 && errno != ENOENT)
-                                        ret = -errno;
-                                continue;
-                        }
-
-                        is_dir = S_ISDIR(st.st_mode);
-                        keep_around =
-                                honour_sticky &&
-                                (st.st_uid == 0 || st.st_uid == getuid()) &&
-                                (st.st_mode & S_ISVTX);
-                } else {
-                        is_dir = de->d_type == DT_DIR;
-                        keep_around = false;
-                }
-
-                if (is_dir) {
-                        int subdir_fd;
-
-                        /* if root_dev is set, remove subdirectories only, if device is same as dir */
-                        if (root_dev && st.st_dev != root_dev->st_dev)
-                                continue;
-
-                        subdir_fd = openat(fd, de->d_name,
-                                           O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW|O_NOATIME);
-                        if (subdir_fd < 0) {
-                                if (ret == 0 && errno != ENOENT)
-                                        ret = -errno;
-                                continue;
-                        }
-
-                        r = rm_rf_children_dangerous(subdir_fd, only_dirs, honour_sticky, root_dev);
-                        if (r < 0 && ret == 0)
-                                ret = r;
-
-                        if (!keep_around)
-                                if (unlinkat(fd, de->d_name, AT_REMOVEDIR) < 0) {
-                                        if (ret == 0 && errno != ENOENT)
-                                                ret = -errno;
-                                }
-
-                } else if (!only_dirs && !keep_around) {
-
-                        if (unlinkat(fd, de->d_name, 0) < 0) {
-                                if (ret == 0 && errno != ENOENT)
-                                        ret = -errno;
-                        }
-                }
-        }
-}
-
-_pure_ static int is_temporary_fs(struct statfs *s) {
+bool is_temporary_fs(const struct statfs *s) {
         assert(s);
 
         return F_TYPE_EQUAL(s->f_type, TMPFS_MAGIC) ||
                F_TYPE_EQUAL(s->f_type, RAMFS_MAGIC);
 }
 
-int is_fd_on_temporary_fs(int fd) {
+int fd_is_temporary_fs(int fd) {
         struct statfs s;
 
         if (fstatfs(fd, &s) < 0)
@@ -3056,114 +3025,6 @@ int is_fd_on_temporary_fs(int fd) {
         return is_temporary_fs(&s);
 }
 
-int rm_rf_children(int fd, bool only_dirs, bool honour_sticky, struct stat *root_dev) {
-        struct statfs s;
-
-        assert(fd >= 0);
-
-        if (fstatfs(fd, &s) < 0) {
-                safe_close(fd);
-                return -errno;
-        }
-
-        /* We refuse to clean disk file systems with this call. This
-         * is extra paranoia just to be sure we never ever remove
-         * non-state data */
-        if (!is_temporary_fs(&s)) {
-                log_error("Attempted to remove disk file system, and we can't allow that.");
-                safe_close(fd);
-                return -EPERM;
-        }
-
-        return rm_rf_children_dangerous(fd, only_dirs, honour_sticky, root_dev);
-}
-
-static int file_is_priv_sticky(const char *p) {
-        struct stat st;
-
-        assert(p);
-
-        if (lstat(p, &st) < 0)
-                return -errno;
-
-        return
-                (st.st_uid == 0 || st.st_uid == getuid()) &&
-                (st.st_mode & S_ISVTX);
-}
-
-static int rm_rf_internal(const char *path, bool only_dirs, bool delete_root, bool honour_sticky, bool dangerous) {
-        int fd, r;
-        struct statfs s;
-
-        assert(path);
-
-        /* We refuse to clean the root file system with this
-         * call. This is extra paranoia to never cause a really
-         * seriously broken system. */
-        if (path_equal(path, "/")) {
-                log_error("Attempted to remove entire root file system, and we can't allow that.");
-                return -EPERM;
-        }
-
-        fd = open(path, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW|O_NOATIME);
-        if (fd < 0) {
-
-                if (errno != ENOTDIR && errno != ELOOP)
-                        return -errno;
-
-                if (!dangerous) {
-                        if (statfs(path, &s) < 0)
-                                return -errno;
-
-                        if (!is_temporary_fs(&s)) {
-                                log_error("Attempted to remove disk file system, and we can't allow that.");
-                                return -EPERM;
-                        }
-                }
-
-                if (delete_root && !only_dirs)
-                        if (unlink(path) < 0 && errno != ENOENT)
-                                return -errno;
-
-                return 0;
-        }
-
-        if (!dangerous) {
-                if (fstatfs(fd, &s) < 0) {
-                        safe_close(fd);
-                        return -errno;
-                }
-
-                if (!is_temporary_fs(&s)) {
-                        log_error("Attempted to remove disk file system, and we can't allow that.");
-                        safe_close(fd);
-                        return -EPERM;
-                }
-        }
-
-        r = rm_rf_children_dangerous(fd, only_dirs, honour_sticky, NULL);
-        if (delete_root) {
-
-                if (honour_sticky && file_is_priv_sticky(path) > 0)
-                        return r;
-
-                if (rmdir(path) < 0 && errno != ENOENT) {
-                        if (r == 0)
-                                r = -errno;
-                }
-        }
-
-        return r;
-}
-
-int rm_rf(const char *path, bool only_dirs, bool delete_root, bool honour_sticky) {
-        return rm_rf_internal(path, only_dirs, delete_root, honour_sticky, false);
-}
-
-int rm_rf_dangerous(const char *path, bool only_dirs, bool delete_root, bool honour_sticky) {
-        return rm_rf_internal(path, only_dirs, delete_root, honour_sticky, true);
-}
-
 int chmod_and_chown(const char *path, mode_t mode, uid_t uid, gid_t gid) {
         assert(path);
 
@@ -3400,14 +3261,14 @@ char **replace_env_argv(char **argv, char **env) {
                 /* If $FOO appears as single word, replace it by the split up variable */
                 if ((*i)[0] == '$' && (*i)[1] != '{') {
                         char *e;
-                        char **w, **m;
+                        char **w, **m = NULL;
                         unsigned q;
 
                         e = strv_env_get(env, *i+1);
                         if (e) {
                                 int r;
 
-                                r = strv_split_quoted(&m, e, true);
+                                r = strv_split_quoted(&m, e, UNQUOTE_RELAX);
                                 if (r < 0) {
                                         ret[k] = NULL;
                                         strv_free(ret);
@@ -4117,8 +3978,7 @@ static int do_execute(char **directories, usec_t timeout, char *argv[]) {
                         if (null_or_empty_path(path)) {
                                 log_debug("%s is empty (a mask).", path);
                                 continue;
-                        } else
-                                log_debug("%s will be executed.", path);
+                        }
 
                         pid = fork();
                         if (pid < 0) {
@@ -6001,7 +5861,7 @@ int on_ac_power(void) {
 
         d = opendir("/sys/class/power_supply");
         if (!d)
-                return -errno;
+                return errno == ENOENT ? true : -errno;
 
         for (;;) {
                 struct dirent *de;
@@ -6379,7 +6239,7 @@ int parse_proc_cmdline(int (*parse_item)(const char *key, const char *value)) {
                 _cleanup_free_ char *word = NULL;
                 char *value = NULL;
 
-                r = unquote_first_word(&p, &word, true);
+                r = unquote_first_word(&p, &word, UNQUOTE_RELAX);
                 if (r < 0)
                         return r;
                 if (r == 0)
@@ -6419,7 +6279,7 @@ int get_proc_cmdline_key(const char *key, char **value) {
                 _cleanup_free_ char *word = NULL;
                 const char *e;
 
-                r = unquote_first_word(&p, &word, true);
+                r = unquote_first_word(&p, &word, UNQUOTE_RELAX);
                 if (r < 0)
                         return r;
                 if (r == 0)
@@ -6666,7 +6526,7 @@ int getpeersec(int fd, char **ret) {
 
         if (isempty(s)) {
                 free(s);
-                return -ENOTSUP;
+                return -EOPNOTSUPP;
         }
 
         *ret = s;
@@ -7272,9 +7132,10 @@ int is_dir(const char* path, bool follow) {
         return !!S_ISDIR(st.st_mode);
 }
 
-int unquote_first_word(const char **p, char **ret, bool relax) {
+int unquote_first_word(const char **p, char **ret, UnquoteFlags flags) {
         _cleanup_free_ char *s = NULL;
         size_t allocated = 0, sz = 0;
+        int r;
 
         enum {
                 START,
@@ -7332,7 +7193,7 @@ int unquote_first_word(const char **p, char **ret, bool relax) {
 
                 case VALUE_ESCAPE:
                         if (c == 0) {
-                                if (relax)
+                                if (flags & UNQUOTE_RELAX)
                                         goto finish;
                                 return -EINVAL;
                         }
@@ -7340,6 +7201,14 @@ int unquote_first_word(const char **p, char **ret, bool relax) {
                         if (!GREEDY_REALLOC(s, allocated, sz+2))
                                 return -ENOMEM;
 
+                        if (flags & UNQUOTE_CUNESCAPE) {
+                                r = cunescape_one(*p, (size_t) -1, &c);
+                                if (r < 0)
+                                        return -EINVAL;
+
+                                (*p) += r - 1;
+                        }
+
                         s[sz++] = c;
                         state = VALUE;
 
@@ -7347,7 +7216,7 @@ int unquote_first_word(const char **p, char **ret, bool relax) {
 
                 case SINGLE_QUOTE:
                         if (c == 0) {
-                                if (relax)
+                                if (flags & UNQUOTE_RELAX)
                                         goto finish;
                                 return -EINVAL;
                         } else if (c == '\'')
@@ -7365,7 +7234,7 @@ int unquote_first_word(const char **p, char **ret, bool relax) {
 
                 case SINGLE_QUOTE_ESCAPE:
                         if (c == 0) {
-                                if (relax)
+                                if (flags & UNQUOTE_RELAX)
                                         goto finish;
                                 return -EINVAL;
                         }
@@ -7373,6 +7242,14 @@ int unquote_first_word(const char **p, char **ret, bool relax) {
                         if (!GREEDY_REALLOC(s, allocated, sz+2))
                                 return -ENOMEM;
 
+                        if (flags & UNQUOTE_CUNESCAPE) {
+                                r = cunescape_one(*p, (size_t) -1, &c);
+                                if (r < 0)
+                                        return -EINVAL;
+
+                                (*p) += r - 1;
+                        }
+
                         s[sz++] = c;
                         state = SINGLE_QUOTE;
                         break;
@@ -7395,7 +7272,7 @@ int unquote_first_word(const char **p, char **ret, bool relax) {
 
                 case DOUBLE_QUOTE_ESCAPE:
                         if (c == 0) {
-                                if (relax)
+                                if (flags & UNQUOTE_RELAX)
                                         goto finish;
                                 return -EINVAL;
                         }
@@ -7403,6 +7280,14 @@ int unquote_first_word(const char **p, char **ret, bool relax) {
                         if (!GREEDY_REALLOC(s, allocated, sz+2))
                                 return -ENOMEM;
 
+                        if (flags & UNQUOTE_CUNESCAPE) {
+                                r = cunescape_one(*p, (size_t) -1, &c);
+                                if (r < 0)
+                                        return -EINVAL;
+
+                                (*p) += r - 1;
+                        }
+
                         s[sz++] = c;
                         state = DOUBLE_QUOTE;
                         break;
@@ -7432,7 +7317,7 @@ finish:
         return 1;
 }
 
-int unquote_many_words(const char **p, ...) {
+int unquote_many_words(const char **p, UnquoteFlags flags, ...) {
         va_list ap;
         char **l;
         int n = 0, i, c, r;
@@ -7443,7 +7328,7 @@ int unquote_many_words(const char **p, ...) {
         assert(p);
 
         /* Count how many words are expected */
-        va_start(ap, p);
+        va_start(ap, flags);
         for (;;) {
                 if (!va_arg(ap, char **))
                         break;
@@ -7458,7 +7343,7 @@ int unquote_many_words(const char **p, ...) {
         l = newa0(char*, n);
         for (c = 0; c < n; c++) {
 
-                r = unquote_first_word(p, &l[c], false);
+                r = unquote_first_word(p, &l[c], flags);
                 if (r < 0) {
                         int j;
 
@@ -7474,7 +7359,7 @@ int unquote_many_words(const char **p, ...) {
 
         /* If we managed to parse all words, return them in the passed
          * in parameters */
-        va_start(ap, p);
+        va_start(ap, flags);
         for (i = 0; i < n; i++) {
                 char **v;
 
@@ -7735,71 +7620,6 @@ int fd_setcrtime(int fd, usec_t usec) {
         return 0;
 }
 
-int same_fd(int a, int b) {
-        struct stat sta, stb;
-        pid_t pid;
-        int r, fa, fb;
-
-        assert(a >= 0);
-        assert(b >= 0);
-
-        /* Compares two file descriptors. Note that semantics are
-         * quite different depending on whether we have kcmp() or we
-         * don't. If we have kcmp() this will only return true for
-         * dup()ed file descriptors, but not otherwise. If we don't
-         * have kcmp() this will also return true for two fds of the same
-         * file, created by separate open() calls. Since we use this
-         * call mostly for filtering out duplicates in the fd store
-         * this difference hopefully doesn't matter too much. */
-
-        if (a == b)
-                return true;
-
-        /* Try to use kcmp() if we have it. */
-        pid = getpid();
-        r = kcmp(pid, pid, KCMP_FILE, a, b);
-        if (r == 0)
-                return true;
-        if (r > 0)
-                return false;
-        if (errno != ENOSYS)
-                return -errno;
-
-        /* We don't have kcmp(), use fstat() instead. */
-        if (fstat(a, &sta) < 0)
-                return -errno;
-
-        if (fstat(b, &stb) < 0)
-                return -errno;
-
-        if ((sta.st_mode & S_IFMT) != (stb.st_mode & S_IFMT))
-                return false;
-
-        /* We consider all device fds different, since two device fds
-         * might refer to quite different device contexts even though
-         * they share the same inode and backing dev_t. */
-
-        if (S_ISCHR(sta.st_mode) || S_ISBLK(sta.st_mode))
-                return false;
-
-        if (sta.st_dev != stb.st_dev || sta.st_ino != stb.st_ino)
-                return false;
-
-        /* The fds refer to the same inode on disk, let's also check
-         * if they have the same fd flags. This is useful to
-         * distuingish the read and write side of a pipe created with
-         * pipe(). */
-        fa = fcntl(a, F_GETFL);
-        if (fa < 0)
-                return -errno;
-
-        fb = fcntl(b, F_GETFL);
-        if (fb < 0)
-                return -errno;
-
-        return fa == fb;
-}
-
 int chattr_fd(int fd, bool b, unsigned mask) {
         unsigned old_attr, new_attr;
 
@@ -7840,6 +7660,28 @@ int chattr_path(const char *p, bool b, unsigned mask) {
         return chattr_fd(fd, b, mask);
 }
 
+int change_attr_fd(int fd, unsigned value, unsigned mask) {
+        unsigned old_attr, new_attr;
+
+        assert(fd >= 0);
+
+        if (mask == 0)
+                return 0;
+
+        if (ioctl(fd, FS_IOC_GETFLAGS, &old_attr) < 0)
+                return -errno;
+
+        new_attr = (old_attr & ~mask) |(value & mask);
+
+        if (new_attr == old_attr)
+                return 0;
+
+        if (ioctl(fd, FS_IOC_SETFLAGS, &new_attr) < 0)
+                return -errno;
+
+        return 0;
+}
+
 int read_attr_fd(int fd, unsigned *ret) {
         assert(fd >= 0);
 
@@ -8120,3 +7962,44 @@ void cmsg_close_all(struct msghdr *mh) {
                 if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS)
                         close_many((int*) CMSG_DATA(cmsg), (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int));
 }
+
+int rename_noreplace(int olddirfd, const char *oldpath, int newdirfd, const char *newpath) {
+        struct stat buf;
+        int ret;
+
+        ret = renameat2(olddirfd, oldpath, newdirfd, newpath, RENAME_NOREPLACE);
+        if (ret >= 0)
+                return 0;
+
+        /* Even though renameat2() exists since Linux 3.15, btrfs added
+         * support for it later. If it is not implemented, fallback to another
+         * method. */
+        if (errno != EINVAL)
+                return -errno;
+
+        /* The link()/unlink() fallback does not work on directories. But
+         * renameat() without RENAME_NOREPLACE gives the same semantics on
+         * directories, except when newpath is an *empty* directory. This is
+         * good enough. */
+        ret = fstatat(olddirfd, oldpath, &buf, AT_SYMLINK_NOFOLLOW);
+        if (ret >= 0 && S_ISDIR(buf.st_mode)) {
+                ret = renameat(olddirfd, oldpath, newdirfd, newpath);
+                return ret >= 0 ? 0 : -errno;
+        }
+
+        /* If it is not a directory, use the link()/unlink() fallback. */
+        ret = linkat(olddirfd, oldpath, newdirfd, newpath, 0);
+        if (ret < 0)
+                return -errno;
+
+        ret = unlinkat(olddirfd, oldpath, 0);
+        if (ret < 0) {
+                /* backup errno before the following unlinkat() alters it */
+                ret = errno;
+                (void) unlinkat(newdirfd, newpath, 0);
+                errno = ret;
+                return -errno;
+        }
+
+        return 0;
+}