util-lib: split out fd-related operations into fd-util.[ch]

[thirdparty/systemd.git] / src / basic / util.c

/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/

/***
  This file is part of systemd.

  Copyright 2010 Lennart Poettering

  systemd is free software; you can redistribute it and/or modify it
  under the terms of the GNU Lesser General Public License as published by
  the Free Software Foundation; either version 2.1 of the License, or
  (at your option) any later version.

  systemd is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/

#include <ctype.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <glob.h>
#include <grp.h>
#include <langinfo.h>
#include <libintl.h>
#include <limits.h>
#include <linux/magic.h>
#include <linux/oom.h>
#include <linux/sched.h>
#include <locale.h>
#include <netinet/ip.h>
#include <poll.h>
#include <pwd.h>
#include <sched.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/mount.h>
#include <sys/personality.h>
#include <sys/prctl.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/statvfs.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/utsname.h>
#include <sys/vfs.h>
#include <sys/wait.h>
#include <sys/xattr.h>
#include <syslog.h>
#include <unistd.h>

/* When we include libgen.h because we need dirname() we immediately
 * undefine basename() since libgen.h defines it as a macro to the
 * POSIX version which is really broken. We prefer GNU basename(). */
#include <libgen.h>
#undef basename

#ifdef HAVE_SYS_AUXV_H
#include <sys/auxv.h>
#endif

/* We include linux/fs.h as last of the system headers, as it
 * otherwise conflicts with sys/mount.h. Yay, Linux is great! */
#include <linux/fs.h>

#include "build.h"
#include "def.h"
#include "device-nodes.h"
#include "env-util.h"
#include "escape.h"
#include "exit-status.h"
#include "fd-util.h"
#include "fileio.h"
#include "formats-util.h"
#include "gunicode.h"
#include "hashmap.h"
#include "hostname-util.h"
#include "ioprio.h"
#include "log.h"
#include "macro.h"
#include "missing.h"
#include "mkdir.h"
#include "path-util.h"
#include "process-util.h"
#include "random-util.h"
#include "signal-util.h"
#include "sparse-endian.h"
#include "string-util.h"
#include "strv.h"
#include "terminal-util.h"
#include "utf8.h"
#include "util.h"
#include "virt.h"

/* Put this test here for a lack of better place */
assert_cc(EAGAIN == EWOULDBLOCK);

int saved_argc = 0;
char **saved_argv = NULL;

size_t page_size(void) {
        static thread_local size_t pgsz = 0;
        long r;

        if (_likely_(pgsz > 0))
                return pgsz;

        r = sysconf(_SC_PAGESIZE);
        assert(r > 0);

        pgsz = (size_t) r;
        return pgsz;
}

int unlink_noerrno(const char *path) {
        PROTECT_ERRNO;
        int r;

        r = unlink(path);
        if (r < 0)
                return -errno;

        return 0;
}

int parse_boolean(const char *v) {
        assert(v);

        if (streq(v, "1") || strcaseeq(v, "yes") || strcaseeq(v, "y") || strcaseeq(v, "true") || strcaseeq(v, "t") || strcaseeq(v, "on"))
                return 1;
        else if (streq(v, "0") || strcaseeq(v, "no") || strcaseeq(v, "n") || strcaseeq(v, "false") || strcaseeq(v, "f") || strcaseeq(v, "off"))
                return 0;

        return -EINVAL;
}

int parse_pid(const char *s, pid_t* ret_pid) {
        unsigned long ul = 0;
        pid_t pid;
        int r;

        assert(s);
        assert(ret_pid);

        r = safe_atolu(s, &ul);
        if (r < 0)
                return r;

        pid = (pid_t) ul;

        if ((unsigned long) pid != ul)
                return -ERANGE;

        if (pid <= 0)
                return -ERANGE;

        *ret_pid = pid;
        return 0;
}

bool uid_is_valid(uid_t uid) {

        /* Some libc APIs use UID_INVALID as special placeholder */
        if (uid == (uid_t) 0xFFFFFFFF)
                return false;

        /* A long time ago UIDs where 16bit, hence explicitly avoid the 16bit -1 too */
        if (uid == (uid_t) 0xFFFF)
                return false;

        return true;
}

int parse_uid(const char *s, uid_t* ret_uid) {
        unsigned long ul = 0;
        uid_t uid;
        int r;

        assert(s);

        r = safe_atolu(s, &ul);
        if (r < 0)
                return r;

        uid = (uid_t) ul;

        if ((unsigned long) uid != ul)
                return -ERANGE;

        if (!uid_is_valid(uid))
                return -ENXIO; /* we return ENXIO instead of EINVAL
                                * here, to make it easy to distuingish
                                * invalid numeric uids invalid
                                * strings. */

        if (ret_uid)
                *ret_uid = uid;

        return 0;
}

int safe_atou(const char *s, unsigned *ret_u) {
        char *x = NULL;
        unsigned long l;

        assert(s);
        assert(ret_u);

        errno = 0;
        l = strtoul(s, &x, 0);

        if (!x || x == s || *x || errno)
                return errno > 0 ? -errno : -EINVAL;

        if ((unsigned long) (unsigned) l != l)
                return -ERANGE;

        *ret_u = (unsigned) l;
        return 0;
}

int safe_atoi(const char *s, int *ret_i) {
        char *x = NULL;
        long l;

        assert(s);
        assert(ret_i);

        errno = 0;
        l = strtol(s, &x, 0);

        if (!x || x == s || *x || errno)
                return errno > 0 ? -errno : -EINVAL;

        if ((long) (int) l != l)
                return -ERANGE;

        *ret_i = (int) l;
        return 0;
}

int safe_atou8(const char *s, uint8_t *ret) {
        char *x = NULL;
        unsigned long l;

        assert(s);
        assert(ret);

        errno = 0;
        l = strtoul(s, &x, 0);

        if (!x || x == s || *x || errno)
                return errno > 0 ? -errno : -EINVAL;

        if ((unsigned long) (uint8_t) l != l)
                return -ERANGE;

        *ret = (uint8_t) l;
        return 0;
}

int safe_atou16(const char *s, uint16_t *ret) {
        char *x = NULL;
        unsigned long l;

        assert(s);
        assert(ret);

        errno = 0;
        l = strtoul(s, &x, 0);

        if (!x || x == s || *x || errno)
                return errno > 0 ? -errno : -EINVAL;

        if ((unsigned long) (uint16_t) l != l)
                return -ERANGE;

        *ret = (uint16_t) l;
        return 0;
}

int safe_atoi16(const char *s, int16_t *ret) {
        char *x = NULL;
        long l;

        assert(s);
        assert(ret);

        errno = 0;
        l = strtol(s, &x, 0);

        if (!x || x == s || *x || errno)
                return errno > 0 ? -errno : -EINVAL;

        if ((long) (int16_t) l != l)
                return -ERANGE;

        *ret = (int16_t) l;
        return 0;
}

int safe_atollu(const char *s, long long unsigned *ret_llu) {
        char *x = NULL;
        unsigned long long l;

        assert(s);
        assert(ret_llu);

        errno = 0;
        l = strtoull(s, &x, 0);

        if (!x || x == s || *x || errno)
                return errno ? -errno : -EINVAL;

        *ret_llu = l;
        return 0;
}

int safe_atolli(const char *s, long long int *ret_lli) {
        char *x = NULL;
        long long l;

        assert(s);
        assert(ret_lli);

        errno = 0;
        l = strtoll(s, &x, 0);

        if (!x || x == s || *x || errno)
                return errno ? -errno : -EINVAL;

        *ret_lli = l;
        return 0;
}

int safe_atod(const char *s, double *ret_d) {
        char *x = NULL;
        double d = 0;
        locale_t loc;

        assert(s);
        assert(ret_d);

        loc = newlocale(LC_NUMERIC_MASK, "C", (locale_t) 0);
        if (loc == (locale_t) 0)
                return -errno;

        errno = 0;
        d = strtod_l(s, &x, loc);

        if (!x || x == s || *x || errno) {
                freelocale(loc);
                return errno ? -errno : -EINVAL;
        }

        freelocale(loc);
        *ret_d = (double) d;
        return 0;
}


int fchmod_umask(int fd, mode_t m) {
        mode_t u;
        int r;

        u = umask(0777);
        r = fchmod(fd, m & (~u)) < 0 ? -errno : 0;
        umask(u);

        return r;
}

int readlinkat_malloc(int fd, const char *p, char **ret) {
        size_t l = 100;
        int r;

        assert(p);
        assert(ret);

        for (;;) {
                char *c;
                ssize_t n;

                c = new(char, l);
                if (!c)
                        return -ENOMEM;

                n = readlinkat(fd, p, c, l-1);
                if (n < 0) {
                        r = -errno;
                        free(c);
                        return r;
                }

                if ((size_t) n < l-1) {
                        c[n] = 0;
                        *ret = c;
                        return 0;
                }

                free(c);
                l *= 2;
        }
}

int readlink_malloc(const char *p, char **ret) {
        return readlinkat_malloc(AT_FDCWD, p, ret);
}

int readlink_value(const char *p, char **ret) {
        _cleanup_free_ char *link = NULL;
        char *value;
        int r;

        r = readlink_malloc(p, &link);
        if (r < 0)
                return r;

        value = basename(link);
        if (!value)
                return -ENOENT;

        value = strdup(value);
        if (!value)
                return -ENOMEM;

        *ret = value;

        return 0;
}

int readlink_and_make_absolute(const char *p, char **r) {
        _cleanup_free_ char *target = NULL;
        char *k;
        int j;

        assert(p);
        assert(r);

        j = readlink_malloc(p, &target);
        if (j < 0)
                return j;

        k = file_in_same_dir(p, target);
        if (!k)
                return -ENOMEM;

        *r = k;
        return 0;
}

int readlink_and_canonicalize(const char *p, char **r) {
        char *t, *s;
        int j;

        assert(p);
        assert(r);

        j = readlink_and_make_absolute(p, &t);
        if (j < 0)
                return j;

        s = canonicalize_file_name(t);
        if (s) {
                free(t);
                *r = s;
        } else
                *r = t;

        path_kill_slashes(*r);

        return 0;
}

char *file_in_same_dir(const char *path, const char *filename) {
        char *e, *ret;
        size_t k;

        assert(path);
        assert(filename);

        /* 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))
                return strdup(filename);

        e = strrchr(path, '/');
        if (!e)
                return strdup(filename);

        k = strlen(filename);
        ret = new(char, (e + 1 - path) + k + 1);
        if (!ret)
                return NULL;

        memcpy(mempcpy(ret, path, e + 1 - path), filename, k + 1);
        return ret;
}

int rmdir_parents(const char *path, const char *stop) {
        size_t l;
        int r = 0;

        assert(path);
        assert(stop);

        l = strlen(path);

        /* Skip trailing slashes */
        while (l > 0 && path[l-1] == '/')
                l--;

        while (l > 0) {
                char *t;

                /* Skip last component */
                while (l > 0 && path[l-1] != '/')
                        l--;

                /* Skip trailing slashes */
                while (l > 0 && path[l-1] == '/')
                        l--;

                if (l <= 0)
                        break;

                if (!(t = strndup(path, l)))
                        return -ENOMEM;

                if (path_startswith(stop, t)) {
                        free(t);
                        return 0;
                }

                r = rmdir(t);
                free(t);

                if (r < 0)
                        if (errno != ENOENT)
                                return -errno;
        }

        return 0;
}

char hexchar(int x) {
        static const char table[16] = "0123456789abcdef";

        return table[x & 15];
}

int unhexchar(char c) {

        if (c >= '0' && c <= '9')
                return c - '0';

        if (c >= 'a' && c <= 'f')
                return c - 'a' + 10;

        if (c >= 'A' && c <= 'F')
                return c - 'A' + 10;

        return -EINVAL;
}

char *hexmem(const void *p, size_t l) {
        char *r, *z;
        const uint8_t *x;

        z = r = malloc(l * 2 + 1);
        if (!r)
                return NULL;

        for (x = p; x < (const uint8_t*) p + l; x++) {
                *(z++) = hexchar(*x >> 4);
                *(z++) = hexchar(*x & 15);
        }

        *z = 0;
        return r;
}

int unhexmem(const char *p, size_t l, void **mem, size_t *len) {
        _cleanup_free_ uint8_t *r = NULL;
        uint8_t *z;
        const char *x;

        assert(mem);
        assert(len);
        assert(p);

        z = r = malloc((l + 1) / 2 + 1);
        if (!r)
                return -ENOMEM;

        for (x = p; x < p + l; x += 2) {
                int a, b;

                a = unhexchar(x[0]);
                if (a < 0)
                        return a;
                else if (x+1 < p + l) {
                        b = unhexchar(x[1]);
                        if (b < 0)
                                return b;
                } else
                        b = 0;

                *(z++) = (uint8_t) a << 4 | (uint8_t) b;
        }

        *z = 0;

        *mem = r;
        r = NULL;
        *len = (l + 1) / 2;

        return 0;
}

/* https://tools.ietf.org/html/rfc4648#section-6
 * Notice that base32hex differs from base32 in the alphabet it uses.
 * The distinction is that the base32hex representation preserves the
 * order of the underlying data when compared as bytestrings, this is
 * useful when representing NSEC3 hashes, as one can then verify the
 * order of hashes directly from their representation. */
char base32hexchar(int x) {
        static const char table[32] = "0123456789"
                                      "ABCDEFGHIJKLMNOPQRSTUV";

        return table[x & 31];
}

int unbase32hexchar(char c) {
        unsigned offset;

        if (c >= '0' && c <= '9')
                return c - '0';

        offset = '9' - '0' + 1;

        if (c >= 'A' && c <= 'V')
                return c - 'A' + offset;

        return -EINVAL;
}

char *base32hexmem(const void *p, size_t l, bool padding) {
        char *r, *z;
        const uint8_t *x;
        size_t len;

        if (padding)
                /* five input bytes makes eight output bytes, padding is added so we must round up */
                len = 8 * (l + 4) / 5;
        else {
                /* same, but round down as there is no padding */
                len = 8 * l / 5;

                switch (l % 5) {
                case 4:
                        len += 7;
                        break;
                case 3:
                        len += 5;
                        break;
                case 2:
                        len += 4;
                        break;
                case 1:
                        len += 2;
                        break;
                }
        }

        z = r = malloc(len + 1);
        if (!r)
                return NULL;

        for (x = p; x < (const uint8_t*) p + (l / 5) * 5; x += 5) {
                /* x[0] == XXXXXXXX; x[1] == YYYYYYYY; x[2] == ZZZZZZZZ
                   x[3] == QQQQQQQQ; x[4] == WWWWWWWW */
                *(z++) = base32hexchar(x[0] >> 3);                    /* 000XXXXX */
                *(z++) = base32hexchar((x[0] & 7) << 2 | x[1] >> 6);  /* 000XXXYY */
                *(z++) = base32hexchar((x[1] & 63) >> 1);             /* 000YYYYY */
                *(z++) = base32hexchar((x[1] & 1) << 4 | x[2] >> 4);  /* 000YZZZZ */
                *(z++) = base32hexchar((x[2] & 15) << 1 | x[3] >> 7); /* 000ZZZZQ */
                *(z++) = base32hexchar((x[3] & 127) >> 2);            /* 000QQQQQ */
                *(z++) = base32hexchar((x[3] & 3) << 3 | x[4] >> 5);  /* 000QQWWW */
                *(z++) = base32hexchar((x[4] & 31));                  /* 000WWWWW */
        }

        switch (l % 5) {
        case 4:
                *(z++) = base32hexchar(x[0] >> 3);                    /* 000XXXXX */
                *(z++) = base32hexchar((x[0] & 7) << 2 | x[1] >> 6);  /* 000XXXYY */
                *(z++) = base32hexchar((x[1] & 63) >> 1);             /* 000YYYYY */
                *(z++) = base32hexchar((x[1] & 1) << 4 | x[2] >> 4);   /* 000YZZZZ */
                *(z++) = base32hexchar((x[2] & 15) << 1 | x[3] >> 7); /* 000ZZZZQ */
                *(z++) = base32hexchar((x[3] & 127) >> 2);            /* 000QQQQQ */
                *(z++) = base32hexchar((x[3] & 3) << 3);              /* 000QQ000 */
                if (padding)
                        *(z++) = '=';

                break;

        case 3:
                *(z++) = base32hexchar(x[0] >> 3);                   /* 000XXXXX */
                *(z++) = base32hexchar((x[0] & 7) << 2 | x[1] >> 6); /* 000XXXYY */
                *(z++) = base32hexchar((x[1] & 63) >> 1);            /* 000YYYYY */
                *(z++) = base32hexchar((x[1] & 1) << 4 | x[2] >> 4); /* 000YZZZZ */
                *(z++) = base32hexchar((x[2] & 15) << 1);            /* 000ZZZZ0 */
                if (padding) {
                        *(z++) = '=';
                        *(z++) = '=';
                        *(z++) = '=';
                }

                break;

        case 2:
                *(z++) = base32hexchar(x[0] >> 3);                   /* 000XXXXX */
                *(z++) = base32hexchar((x[0] & 7) << 2 | x[1] >> 6); /* 000XXXYY */
                *(z++) = base32hexchar((x[1] & 63) >> 1);            /* 000YYYYY */
                *(z++) = base32hexchar((x[1] & 1) << 4);             /* 000Y0000 */
                if (padding) {
                        *(z++) = '=';
                        *(z++) = '=';
                        *(z++) = '=';
                        *(z++) = '=';
                }

                break;

        case 1:
                *(z++) = base32hexchar(x[0] >> 3);       /* 000XXXXX */
                *(z++) = base32hexchar((x[0] & 7) << 2); /* 000XXX00 */
                if (padding) {
                        *(z++) = '=';
                        *(z++) = '=';
                        *(z++) = '=';
                        *(z++) = '=';
                        *(z++) = '=';
                        *(z++) = '=';
                }

                break;
        }

        *z = 0;
        return r;
}

int unbase32hexmem(const char *p, size_t l, bool padding, void **mem, size_t *_len) {
        _cleanup_free_ uint8_t *r = NULL;
        int a, b, c, d, e, f, g, h;
        uint8_t *z;
        const char *x;
        size_t len;
        unsigned pad = 0;

        assert(p);

        /* padding ensures any base32hex input has input divisible by 8 */
        if (padding && l % 8 != 0)
                return -EINVAL;

        if (padding) {
                /* strip the padding */
                while (l > 0 && p[l - 1] == '=' && pad < 7) {
                        pad ++;
                        l --;
                }
        }

        /* a group of eight input bytes needs five output bytes, in case of
           padding we need to add some extra bytes */
        len = (l / 8) * 5;

        switch (l % 8) {
        case 7:
                len += 4;
                break;
        case 5:
                len += 3;
                break;
        case 4:
                len += 2;
                break;
        case 2:
                len += 1;
                break;
        case 0:
                break;
        default:
                return -EINVAL;
        }

        z = r = malloc(len + 1);
        if (!r)
                return -ENOMEM;

        for (x = p; x < p + (l / 8) * 8; x += 8) {
                /* a == 000XXXXX; b == 000YYYYY; c == 000ZZZZZ; d == 000WWWWW
                   e == 000SSSSS; f == 000QQQQQ; g == 000VVVVV; h == 000RRRRR */
                a = unbase32hexchar(x[0]);
                if (a < 0)
                        return -EINVAL;

                b = unbase32hexchar(x[1]);
                if (b < 0)
                        return -EINVAL;

                c = unbase32hexchar(x[2]);
                if (c < 0)
                        return -EINVAL;

                d = unbase32hexchar(x[3]);
                if (d < 0)
                        return -EINVAL;

                e = unbase32hexchar(x[4]);
                if (e < 0)
                        return -EINVAL;

                f = unbase32hexchar(x[5]);
                if (f < 0)
                        return -EINVAL;

                g = unbase32hexchar(x[6]);
                if (g < 0)
                        return -EINVAL;

                h = unbase32hexchar(x[7]);
                if (h < 0)
                        return -EINVAL;

                *(z++) = (uint8_t) a << 3 | (uint8_t) b >> 2;                    /* XXXXXYYY */
                *(z++) = (uint8_t) b << 6 | (uint8_t) c << 1 | (uint8_t) d >> 4; /* YYZZZZZW */
                *(z++) = (uint8_t) d << 4 | (uint8_t) e >> 1;                    /* WWWWSSSS */
                *(z++) = (uint8_t) e << 7 | (uint8_t) f << 2 | (uint8_t) g >> 3; /* SQQQQQVV */
                *(z++) = (uint8_t) g << 5 | (uint8_t) h;                         /* VVVRRRRR */
        }

        switch (l % 8) {
        case 7:
                a = unbase32hexchar(x[0]);
                if (a < 0)
                        return -EINVAL;

                b = unbase32hexchar(x[1]);
                if (b < 0)
                        return -EINVAL;

                c = unbase32hexchar(x[2]);
                if (c < 0)
                        return -EINVAL;

                d = unbase32hexchar(x[3]);
                if (d < 0)
                        return -EINVAL;

                e = unbase32hexchar(x[4]);
                if (e < 0)
                        return -EINVAL;

                f = unbase32hexchar(x[5]);
                if (f < 0)
                        return -EINVAL;

                g = unbase32hexchar(x[6]);
                if (g < 0)
                        return -EINVAL;

                /* g == 000VV000 */
                if (g & 7)
                        return -EINVAL;

                *(z++) = (uint8_t) a << 3 | (uint8_t) b >> 2;                    /* XXXXXYYY */
                *(z++) = (uint8_t) b << 6 | (uint8_t) c << 1 | (uint8_t) d >> 4; /* YYZZZZZW */
                *(z++) = (uint8_t) d << 4 | (uint8_t) e >> 1;                    /* WWWWSSSS */
                *(z++) = (uint8_t) e << 7 | (uint8_t) f << 2 | (uint8_t) g >> 3; /* SQQQQQVV */

                break;
        case 5:
                a = unbase32hexchar(x[0]);
                if (a < 0)
                        return -EINVAL;

                b = unbase32hexchar(x[1]);
                if (b < 0)
                        return -EINVAL;

                c = unbase32hexchar(x[2]);
                if (c < 0)
                        return -EINVAL;

                d = unbase32hexchar(x[3]);
                if (d < 0)
                        return -EINVAL;

                e = unbase32hexchar(x[4]);
                if (e < 0)
                        return -EINVAL;

                /* e == 000SSSS0 */
                if (e & 1)
                        return -EINVAL;

                *(z++) = (uint8_t) a << 3 | (uint8_t) b >> 2;                    /* XXXXXYYY */
                *(z++) = (uint8_t) b << 6 | (uint8_t) c << 1 | (uint8_t) d >> 4; /* YYZZZZZW */
                *(z++) = (uint8_t) d << 4 | (uint8_t) e >> 1;                    /* WWWWSSSS */

                break;
        case 4:
                a = unbase32hexchar(x[0]);
                if (a < 0)
                        return -EINVAL;

                b = unbase32hexchar(x[1]);
                if (b < 0)
                        return -EINVAL;

                c = unbase32hexchar(x[2]);
                if (c < 0)
                        return -EINVAL;

                d = unbase32hexchar(x[3]);
                if (d < 0)
                        return -EINVAL;

                /* d == 000W0000 */
                if (d & 15)
                        return -EINVAL;

                *(z++) = (uint8_t) a << 3 | (uint8_t) b >> 2;                    /* XXXXXYYY */
                *(z++) = (uint8_t) b << 6 | (uint8_t) c << 1 | (uint8_t) d >> 4; /* YYZZZZZW */

                break;
        case 2:
                a = unbase32hexchar(x[0]);
                if (a < 0)
                        return -EINVAL;

                b = unbase32hexchar(x[1]);
                if (b < 0)
                        return -EINVAL;

                /* b == 000YYY00 */
                if (b & 3)
                        return -EINVAL;

                *(z++) = (uint8_t) a << 3 | (uint8_t) b >> 2; /* XXXXXYYY */

                break;
        case 0:
                break;
        default:
                return -EINVAL;
        }

        *z = 0;

        *mem = r;
        r = NULL;
        *_len = len;

        return 0;
}

/* https://tools.ietf.org/html/rfc4648#section-4 */
char base64char(int x) {
        static const char table[64] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
                                      "abcdefghijklmnopqrstuvwxyz"
                                      "0123456789+/";
        return table[x & 63];
}

int unbase64char(char c) {
        unsigned offset;

        if (c >= 'A' && c <= 'Z')
                return c - 'A';

        offset = 'Z' - 'A' + 1;

        if (c >= 'a' && c <= 'z')
                return c - 'a' + offset;

        offset += 'z' - 'a' + 1;

        if (c >= '0' && c <= '9')
                return c - '0' + offset;

        offset += '9' - '0' + 1;

        if (c == '+')
                return offset;

        offset ++;

        if (c == '/')
                return offset;

        return -EINVAL;
}

char *base64mem(const void *p, size_t l) {
        char *r, *z;
        const uint8_t *x;

        /* three input bytes makes four output bytes, padding is added so we must round up */
        z = r = malloc(4 * (l + 2) / 3 + 1);
        if (!r)
                return NULL;

        for (x = p; x < (const uint8_t*) p + (l / 3) * 3; x += 3) {
                /* x[0] == XXXXXXXX; x[1] == YYYYYYYY; x[2] == ZZZZZZZZ */
                *(z++) = base64char(x[0] >> 2);                    /* 00XXXXXX */
                *(z++) = base64char((x[0] & 3) << 4 | x[1] >> 4);  /* 00XXYYYY */
                *(z++) = base64char((x[1] & 15) << 2 | x[2] >> 6); /* 00YYYYZZ */
                *(z++) = base64char(x[2] & 63);                    /* 00ZZZZZZ */
        }

        switch (l % 3) {
        case 2:
                *(z++) = base64char(x[0] >> 2);                   /* 00XXXXXX */
                *(z++) = base64char((x[0] & 3) << 4 | x[1] >> 4); /* 00XXYYYY */
                *(z++) = base64char((x[1] & 15) << 2);            /* 00YYYY00 */
                *(z++) = '=';

                break;
        case 1:
                *(z++) = base64char(x[0] >> 2);        /* 00XXXXXX */
                *(z++) = base64char((x[0] & 3) << 4);  /* 00XX0000 */
                *(z++) = '=';
                *(z++) = '=';

                break;
        }

        *z = 0;
        return r;
}

int unbase64mem(const char *p, size_t l, void **mem, size_t *_len) {
        _cleanup_free_ uint8_t *r = NULL;
        int a, b, c, d;
        uint8_t *z;
        const char *x;
        size_t len;

        assert(p);

        /* padding ensures any base63 input has input divisible by 4 */
        if (l % 4 != 0)
                return -EINVAL;

        /* strip the padding */
        if (l > 0 && p[l - 1] == '=')
                l --;
        if (l > 0 && p[l - 1] == '=')
                l --;

        /* a group of four input bytes needs three output bytes, in case of
           padding we need to add two or three extra bytes */
        len = (l / 4) * 3 + (l % 4 ? (l % 4) - 1 : 0);

        z = r = malloc(len + 1);
        if (!r)
                return -ENOMEM;

        for (x = p; x < p + (l / 4) * 4; x += 4) {
                /* a == 00XXXXXX; b == 00YYYYYY; c == 00ZZZZZZ; d == 00WWWWWW */
                a = unbase64char(x[0]);
                if (a < 0)
                        return -EINVAL;

                b = unbase64char(x[1]);
                if (b < 0)
                        return -EINVAL;

                c = unbase64char(x[2]);
                if (c < 0)
                        return -EINVAL;

                d = unbase64char(x[3]);
                if (d < 0)
                        return -EINVAL;

                *(z++) = (uint8_t) a << 2 | (uint8_t) b >> 4; /* XXXXXXYY */
                *(z++) = (uint8_t) b << 4 | (uint8_t) c >> 2; /* YYYYZZZZ */
                *(z++) = (uint8_t) c << 6 | (uint8_t) d;      /* ZZWWWWWW */
        }

        switch (l % 4) {
        case 3:
                a = unbase64char(x[0]);
                if (a < 0)
                        return -EINVAL;

                b = unbase64char(x[1]);
                if (b < 0)
                        return -EINVAL;

                c = unbase64char(x[2]);
                if (c < 0)
                        return -EINVAL;

                /* c == 00ZZZZ00 */
                if (c & 3)
                        return -EINVAL;

                *(z++) = (uint8_t) a << 2 | (uint8_t) b >> 4; /* XXXXXXYY */
                *(z++) = (uint8_t) b << 4 | (uint8_t) c >> 2; /* YYYYZZZZ */

                break;
        case 2:
                a = unbase64char(x[0]);
                if (a < 0)
                        return -EINVAL;

                b = unbase64char(x[1]);
                if (b < 0)
                        return -EINVAL;

                /* b == 00YY0000 */
                if (b & 15)
                        return -EINVAL;

                *(z++) = (uint8_t) a << 2 | (uint8_t) (b >> 4); /* XXXXXXYY */

                break;
        case 0:

                break;
        default:
                return -EINVAL;
        }

        *z = 0;

        *mem = r;
        r = NULL;
        *_len = len;

        return 0;
}

char octchar(int x) {
        return '0' + (x & 7);
}

int unoctchar(char c) {

        if (c >= '0' && c <= '7')
                return c - '0';

        return -EINVAL;
}

char decchar(int x) {
        return '0' + (x % 10);
}

int undecchar(char c) {

        if (c >= '0' && c <= '9')
                return c - '0';

        return -EINVAL;
}

_pure_ static bool hidden_file_allow_backup(const char *filename) {
        assert(filename);

        return
                filename[0] == '.' ||
                streq(filename, "lost+found") ||
                streq(filename, "aquota.user") ||
                streq(filename, "aquota.group") ||
                endswith(filename, ".rpmnew") ||
                endswith(filename, ".rpmsave") ||
                endswith(filename, ".rpmorig") ||
                endswith(filename, ".dpkg-old") ||
                endswith(filename, ".dpkg-new") ||
                endswith(filename, ".dpkg-tmp") ||
                endswith(filename, ".dpkg-dist") ||
                endswith(filename, ".dpkg-bak") ||
                endswith(filename, ".dpkg-backup") ||
                endswith(filename, ".dpkg-remove") ||
                endswith(filename, ".swp");
}

bool hidden_file(const char *filename) {
        assert(filename);

        if (endswith(filename, "~"))
                return true;

        return hidden_file_allow_backup(filename);
}

bool fstype_is_network(const char *fstype) {
        static const char table[] =
                "afs\0"
                "cifs\0"
                "smbfs\0"
                "sshfs\0"
                "ncpfs\0"
                "ncp\0"
                "nfs\0"
                "nfs4\0"
                "gfs\0"
                "gfs2\0"
                "glusterfs\0";

        const char *x;

        x = startswith(fstype, "fuse.");
        if (x)
                fstype = x;

        return nulstr_contains(table, fstype);
}

int flush_fd(int fd) {
        struct pollfd pollfd = {
                .fd = fd,
                .events = POLLIN,
        };

        for (;;) {
                char buf[LINE_MAX];
                ssize_t l;
                int r;

                r = poll(&pollfd, 1, 0);
                if (r < 0) {
                        if (errno == EINTR)
                                continue;

                        return -errno;

                } else if (r == 0)
                        return 0;

                l = read(fd, buf, sizeof(buf));
                if (l < 0) {

                        if (errno == EINTR)
                                continue;

                        if (errno == EAGAIN)
                                return 0;

                        return -errno;
                } else if (l == 0)
                        return 0;
        }
}

ssize_t loop_read(int fd, void *buf, size_t nbytes, bool do_poll) {
        uint8_t *p = buf;
        ssize_t n = 0;

        assert(fd >= 0);
        assert(buf);

        /* If called with nbytes == 0, let's call read() at least
         * once, to validate the operation */

        if (nbytes > (size_t) SSIZE_MAX)
                return -EINVAL;

        do {
                ssize_t k;

                k = read(fd, p, nbytes);
                if (k < 0) {
                        if (errno == EINTR)
                                continue;

                        if (errno == EAGAIN && do_poll) {

                                /* We knowingly ignore any return value here,
                                 * and expect that any error/EOF is reported
                                 * via read() */

                                (void) fd_wait_for_event(fd, POLLIN, USEC_INFINITY);
                                continue;
                        }

                        return n > 0 ? n : -errno;
                }

                if (k == 0)
                        return n;

                assert((size_t) k <= nbytes);

                p += k;
                nbytes -= k;
                n += k;
        } while (nbytes > 0);

        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 (int) 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;

        assert(fd >= 0);
        assert(buf);

        if (nbytes > (size_t) SSIZE_MAX)
                return -EINVAL;

        do {
                ssize_t k;

                k = write(fd, p, nbytes);
                if (k < 0) {
                        if (errno == EINTR)
                                continue;

                        if (errno == EAGAIN && do_poll) {
                                /* We knowingly ignore any return value here,
                                 * and expect that any error/EOF is reported
                                 * via write() */

                                (void) fd_wait_for_event(fd, POLLOUT, USEC_INFINITY);
                                continue;
                        }

                        return -errno;
                }

                if (_unlikely_(nbytes > 0 && k == 0)) /* Can't really happen */
                        return -EIO;

                assert((size_t) k <= nbytes);

                p += k;
                nbytes -= k;
        } while (nbytes > 0);

        return 0;
}

int parse_size(const char *t, uint64_t base, uint64_t *size) {

        /* Soo, sometimes we want to parse IEC binary suffixes, and
         * sometimes SI decimal suffixes. This function can parse
         * both. Which one is the right way depends on the
         * context. Wikipedia suggests that SI is customary for
         * hardware metrics and network speeds, while IEC is
         * customary for most data sizes used by software and volatile
         * (RAM) memory. Hence be careful which one you pick!
         *
         * In either case we use just K, M, G as suffix, and not Ki,
         * Mi, Gi or so (as IEC would suggest). That's because that's
         * frickin' ugly. But this means you really need to make sure
         * to document which base you are parsing when you use this
         * call. */

        struct table {
                const char *suffix;
                unsigned long long factor;
        };

        static const struct table iec[] = {
                { "E", 1024ULL*1024ULL*1024ULL*1024ULL*1024ULL*1024ULL },
                { "P", 1024ULL*1024ULL*1024ULL*1024ULL*1024ULL },
                { "T", 1024ULL*1024ULL*1024ULL*1024ULL },
                { "G", 1024ULL*1024ULL*1024ULL },
                { "M", 1024ULL*1024ULL },
                { "K", 1024ULL },
                { "B", 1ULL },
                { "",  1ULL },
        };

        static const struct table si[] = {
                { "E", 1000ULL*1000ULL*1000ULL*1000ULL*1000ULL*1000ULL },
                { "P", 1000ULL*1000ULL*1000ULL*1000ULL*1000ULL },
                { "T", 1000ULL*1000ULL*1000ULL*1000ULL },
                { "G", 1000ULL*1000ULL*1000ULL },
                { "M", 1000ULL*1000ULL },
                { "K", 1000ULL },
                { "B", 1ULL },
                { "",  1ULL },
        };

        const struct table *table;
        const char *p;
        unsigned long long r = 0;
        unsigned n_entries, start_pos = 0;

        assert(t);
        assert(base == 1000 || base == 1024);
        assert(size);

        if (base == 1000) {
                table = si;
                n_entries = ELEMENTSOF(si);
        } else {
                table = iec;
                n_entries = ELEMENTSOF(iec);
        }

        p = t;
        do {
                unsigned long long l, tmp;
                double frac = 0;
                char *e;
                unsigned i;

                p += strspn(p, WHITESPACE);
                if (*p == '-')
                        return -ERANGE;

                errno = 0;
                l = strtoull(p, &e, 10);
                if (errno > 0)
                        return -errno;
                if (e == p)
                        return -EINVAL;

                if (*e == '.') {
                        e++;

                        /* strtoull() itself would accept space/+/- */
                        if (*e >= '0' && *e <= '9') {
                                unsigned long long l2;
                                char *e2;

                                l2 = strtoull(e, &e2, 10);
                                if (errno > 0)
                                        return -errno;

                                /* Ignore failure. E.g. 10.M is valid */
                                frac = l2;
                                for (; e < e2; e++)
                                        frac /= 10;
                        }
                }

                e += strspn(e, WHITESPACE);

                for (i = start_pos; i < n_entries; i++)
                        if (startswith(e, table[i].suffix))
                                break;

                if (i >= n_entries)
                        return -EINVAL;

                if (l + (frac > 0) > ULLONG_MAX / table[i].factor)
                        return -ERANGE;

                tmp = l * table[i].factor + (unsigned long long) (frac * table[i].factor);
                if (tmp > ULLONG_MAX - r)
                        return -ERANGE;

                r += tmp;
                if ((unsigned long long) (uint64_t) r != r)
                        return -ERANGE;

                p = e + strlen(table[i].suffix);

                start_pos = i + 1;

        } while (*p);

        *size = r;

        return 0;
}

bool is_device_path(const char *path) {

        /* Returns true on paths that refer to a device, either in
         * sysfs or in /dev */

        return
                path_startswith(path, "/dev/") ||
                path_startswith(path, "/sys/");
}

int dir_is_empty(const char *path) {
        _cleanup_closedir_ DIR *d;
        struct dirent *de;

        d = opendir(path);
        if (!d)
                return -errno;

        FOREACH_DIRENT(de, d, return -errno)
                return 0;

        return 1;
}

char* dirname_malloc(const char *path) {
        char *d, *dir, *dir2;

        d = strdup(path);
        if (!d)
                return NULL;
        dir = dirname(d);
        assert(dir);

        if (dir != d) {
                dir2 = strdup(dir);
                free(d);
                return dir2;
        }

        return dir;
}

void rename_process(const char name[8]) {
        assert(name);

        /* This is a like a poor man's setproctitle(). It changes the
         * comm field, argv[0], and also the glibc's internally used
         * name of the process. For the first one a limit of 16 chars
         * applies, to the second one usually one of 10 (i.e. length
         * of "/sbin/init"), to the third one one of 7 (i.e. length of
         * "systemd"). If you pass a longer string it will be
         * truncated */

        prctl(PR_SET_NAME, name);

        if (program_invocation_name)
                strncpy(program_invocation_name, name, strlen(program_invocation_name));

        if (saved_argc > 0) {
                int i;

                if (saved_argv[0])
                        strncpy(saved_argv[0], name, strlen(saved_argv[0]));

                for (i = 1; i < saved_argc; i++) {
                        if (!saved_argv[i])
                                break;

                        memzero(saved_argv[i], strlen(saved_argv[i]));
                }
        }
}

char *lookup_uid(uid_t uid) {
        long bufsize;
        char *name;
        _cleanup_free_ char *buf = NULL;
        struct passwd pwbuf, *pw = NULL;

        /* Shortcut things to avoid NSS lookups */
        if (uid == 0)
                return strdup("root");

        bufsize = sysconf(_SC_GETPW_R_SIZE_MAX);
        if (bufsize <= 0)
                bufsize = 4096;

        buf = malloc(bufsize);
        if (!buf)
                return NULL;

        if (getpwuid_r(uid, &pwbuf, buf, bufsize, &pw) == 0 && pw)
                return strdup(pw->pw_name);

        if (asprintf(&name, UID_FMT, uid) < 0)
                return NULL;

        return name;
}

char* getlogname_malloc(void) {
        uid_t uid;
        struct stat st;

        if (isatty(STDIN_FILENO) && fstat(STDIN_FILENO, &st) >= 0)
                uid = st.st_uid;
        else
                uid = getuid();

        return lookup_uid(uid);
}

char *getusername_malloc(void) {
        const char *e;

        e = getenv("USER");
        if (e)
                return strdup(e);

        return lookup_uid(getuid());
}

bool is_fs_type(const struct statfs *s, statfs_f_type_t magic_value) {
        assert(s);
        assert_cc(sizeof(statfs_f_type_t) >= sizeof(s->f_type));

        return F_TYPE_EQUAL(s->f_type, magic_value);
}

int fd_check_fstype(int fd, statfs_f_type_t magic_value) {
        struct statfs s;

        if (fstatfs(fd, &s) < 0)
                return -errno;

        return is_fs_type(&s, magic_value);
}

int path_check_fstype(const char *path, statfs_f_type_t magic_value) {
        _cleanup_close_ int fd = -1;

        fd = open(path, O_RDONLY);
        if (fd < 0)
                return -errno;

        return fd_check_fstype(fd, magic_value);
}

bool is_temporary_fs(const struct statfs *s) {
    return is_fs_type(s, TMPFS_MAGIC) ||
           is_fs_type(s, RAMFS_MAGIC);
}

int fd_is_temporary_fs(int fd) {
        struct statfs s;

        if (fstatfs(fd, &s) < 0)
                return -errno;

        return is_temporary_fs(&s);
}

int chmod_and_chown(const char *path, mode_t mode, uid_t uid, gid_t gid) {
        assert(path);

        /* Under the assumption that we are running privileged we
         * first change the access mode and only then hand out
         * ownership to avoid a window where access is too open. */

        if (mode != MODE_INVALID)
                if (chmod(path, mode) < 0)
                        return -errno;

        if (uid != UID_INVALID || gid != GID_INVALID)
                if (chown(path, uid, gid) < 0)
                        return -errno;

        return 0;
}

int fchmod_and_fchown(int fd, mode_t mode, uid_t uid, gid_t gid) {
        assert(fd >= 0);

        /* Under the assumption that we are running privileged we
         * first change the access mode and only then hand out
         * ownership to avoid a window where access is too open. */

        if (mode != MODE_INVALID)
                if (fchmod(fd, mode) < 0)
                        return -errno;

        if (uid != UID_INVALID || gid != GID_INVALID)
                if (fchown(fd, uid, gid) < 0)
                        return -errno;

        return 0;
}

int files_same(const char *filea, const char *fileb) {
        struct stat a, b;

        if (stat(filea, &a) < 0)
                return -errno;

        if (stat(fileb, &b) < 0)
                return -errno;

        return a.st_dev == b.st_dev &&
               a.st_ino == b.st_ino;
}

int running_in_chroot(void) {
        int ret;

        ret = files_same("/proc/1/root", "/");
        if (ret < 0)
                return ret;

        return ret == 0;
}

int touch_file(const char *path, bool parents, usec_t stamp, uid_t uid, gid_t gid, mode_t mode) {
        _cleanup_close_ int fd;
        int r;

        assert(path);

        if (parents)
                mkdir_parents(path, 0755);

        fd = open(path, O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, mode > 0 ? mode : 0644);
        if (fd < 0)
                return -errno;

        if (mode > 0) {
                r = fchmod(fd, mode);
                if (r < 0)
                        return -errno;
        }

        if (uid != UID_INVALID || gid != GID_INVALID) {
                r = fchown(fd, uid, gid);
                if (r < 0)
                        return -errno;
        }

        if (stamp != USEC_INFINITY) {
                struct timespec ts[2];

                timespec_store(&ts[0], stamp);
                ts[1] = ts[0];
                r = futimens(fd, ts);
        } else
                r = futimens(fd, NULL);
        if (r < 0)
                return -errno;

        return 0;
}

int touch(const char *path) {
        return touch_file(path, false, USEC_INFINITY, UID_INVALID, GID_INVALID, 0);
}

static char *unquote(const char *s, const char* quotes) {
        size_t l;
        assert(s);

        /* This is rather stupid, simply removes the heading and
         * trailing quotes if there is one. Doesn't care about
         * escaping or anything.
         *
         * DON'T USE THIS FOR NEW CODE ANYMORE!*/

        l = strlen(s);
        if (l < 2)
                return strdup(s);

        if (strchr(quotes, s[0]) && s[l-1] == s[0])
                return strndup(s+1, l-2);

        return strdup(s);
}

noreturn void freeze(void) {

        /* Make sure nobody waits for us on a socket anymore */
        close_all_fds(NULL, 0);

        sync();

        for (;;)
                pause();
}

bool null_or_empty(struct stat *st) {
        assert(st);

        if (S_ISREG(st->st_mode) && st->st_size <= 0)
                return true;

        if (S_ISCHR(st->st_mode) || S_ISBLK(st->st_mode))
                return true;

        return false;
}

int null_or_empty_path(const char *fn) {
        struct stat st;

        assert(fn);

        if (stat(fn, &st) < 0)
                return -errno;

        return null_or_empty(&st);
}

int null_or_empty_fd(int fd) {
        struct stat st;

        assert(fd >= 0);

        if (fstat(fd, &st) < 0)
                return -errno;

        return null_or_empty(&st);
}

DIR *xopendirat(int fd, const char *name, int flags) {
        int nfd;
        DIR *d;

        assert(!(flags & O_CREAT));

        nfd = openat(fd, name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|flags, 0);
        if (nfd < 0)
                return NULL;

        d = fdopendir(nfd);
        if (!d) {
                safe_close(nfd);
                return NULL;
        }

        return d;
}

static char *tag_to_udev_node(const char *tagvalue, const char *by) {
        _cleanup_free_ char *t = NULL, *u = NULL;
        size_t enc_len;

        u = unquote(tagvalue, QUOTES);
        if (!u)
                return NULL;

        enc_len = strlen(u) * 4 + 1;
        t = new(char, enc_len);
        if (!t)
                return NULL;

        if (encode_devnode_name(u, t, enc_len) < 0)
                return NULL;

        return strjoin("/dev/disk/by-", by, "/", t, NULL);
}

char *fstab_node_to_udev_node(const char *p) {
        assert(p);

        if (startswith(p, "LABEL="))
                return tag_to_udev_node(p+6, "label");

        if (startswith(p, "UUID="))
                return tag_to_udev_node(p+5, "uuid");

        if (startswith(p, "PARTUUID="))
                return tag_to_udev_node(p+9, "partuuid");

        if (startswith(p, "PARTLABEL="))
                return tag_to_udev_node(p+10, "partlabel");

        return strdup(p);
}

bool dirent_is_file(const struct dirent *de) {
        assert(de);

        if (hidden_file(de->d_name))
                return false;

        if (de->d_type != DT_REG &&
            de->d_type != DT_LNK &&
            de->d_type != DT_UNKNOWN)
                return false;

        return true;
}

bool dirent_is_file_with_suffix(const struct dirent *de, const char *suffix) {
        assert(de);

        if (de->d_type != DT_REG &&
            de->d_type != DT_LNK &&
            de->d_type != DT_UNKNOWN)
                return false;

        if (hidden_file_allow_backup(de->d_name))
                return false;

        return endswith(de->d_name, suffix);
}

static int do_execute(char **directories, usec_t timeout, char *argv[]) {
        _cleanup_hashmap_free_free_ Hashmap *pids = NULL;
        _cleanup_set_free_free_ Set *seen = NULL;
        char **directory;

        /* We fork this all off from a child process so that we can
         * somewhat cleanly make use of SIGALRM to set a time limit */

        (void) reset_all_signal_handlers();
        (void) reset_signal_mask();

        assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0);

        pids = hashmap_new(NULL);
        if (!pids)
                return log_oom();

        seen = set_new(&string_hash_ops);
        if (!seen)
                return log_oom();

        STRV_FOREACH(directory, directories) {
                _cleanup_closedir_ DIR *d;
                struct dirent *de;

                d = opendir(*directory);
                if (!d) {
                        if (errno == ENOENT)
                                continue;

                        return log_error_errno(errno, "Failed to open directory %s: %m", *directory);
                }

                FOREACH_DIRENT(de, d, break) {
                        _cleanup_free_ char *path = NULL;
                        pid_t pid;
                        int r;

                        if (!dirent_is_file(de))
                                continue;

                        if (set_contains(seen, de->d_name)) {
                                log_debug("%1$s/%2$s skipped (%2$s was already seen).", *directory, de->d_name);
                                continue;
                        }

                        r = set_put_strdup(seen, de->d_name);
                        if (r < 0)
                                return log_oom();

                        path = strjoin(*directory, "/", de->d_name, NULL);
                        if (!path)
                                return log_oom();

                        if (null_or_empty_path(path)) {
                                log_debug("%s is empty (a mask).", path);
                                continue;
                        }

                        pid = fork();
                        if (pid < 0) {
                                log_error_errno(errno, "Failed to fork: %m");
                                continue;
                        } else if (pid == 0) {
                                char *_argv[2];

                                assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0);

                                if (!argv) {
                                        _argv[0] = path;
                                        _argv[1] = NULL;
                                        argv = _argv;
                                } else
                                        argv[0] = path;

                                execv(path, argv);
                                return log_error_errno(errno, "Failed to execute %s: %m", path);
                        }

                        log_debug("Spawned %s as " PID_FMT ".", path, pid);

                        r = hashmap_put(pids, UINT_TO_PTR(pid), path);
                        if (r < 0)
                                return log_oom();
                        path = NULL;
                }
        }

        /* Abort execution of this process after the timout. We simply
         * rely on SIGALRM as default action terminating the process,
         * and turn on alarm(). */

        if (timeout != USEC_INFINITY)
                alarm((timeout + USEC_PER_SEC - 1) / USEC_PER_SEC);

        while (!hashmap_isempty(pids)) {
                _cleanup_free_ char *path = NULL;
                pid_t pid;

                pid = PTR_TO_UINT(hashmap_first_key(pids));
                assert(pid > 0);

                path = hashmap_remove(pids, UINT_TO_PTR(pid));
                assert(path);

                wait_for_terminate_and_warn(path, pid, true);
        }

        return 0;
}

void execute_directories(const char* const* directories, usec_t timeout, char *argv[]) {
        pid_t executor_pid;
        int r;
        char *name;
        char **dirs = (char**) directories;

        assert(!strv_isempty(dirs));

        name = basename(dirs[0]);
        assert(!isempty(name));

        /* Executes all binaries in the directories in parallel and waits
         * for them to finish. Optionally a timeout is applied. If a file
         * with the same name exists in more than one directory, the
         * earliest one wins. */

        executor_pid = fork();
        if (executor_pid < 0) {
                log_error_errno(errno, "Failed to fork: %m");
                return;

        } else if (executor_pid == 0) {
                r = do_execute(dirs, timeout, argv);
                _exit(r < 0 ? EXIT_FAILURE : EXIT_SUCCESS);
        }

        wait_for_terminate_and_warn(name, executor_pid, true);
}

bool plymouth_running(void) {
        return access("/run/plymouth/pid", F_OK) >= 0;
}

int pipe_eof(int fd) {
        struct pollfd pollfd = {
                .fd = fd,
                .events = POLLIN|POLLHUP,
        };

        int r;

        r = poll(&pollfd, 1, 0);
        if (r < 0)
                return -errno;

        if (r == 0)
                return 0;

        return pollfd.revents & POLLHUP;
}

int fd_wait_for_event(int fd, int event, usec_t t) {

        struct pollfd pollfd = {
                .fd = fd,
                .events = event,
        };

        struct timespec ts;
        int r;

        r = ppoll(&pollfd, 1, t == USEC_INFINITY ? NULL : timespec_store(&ts, t), NULL);
        if (r < 0)
                return -errno;

        if (r == 0)
                return 0;

        return pollfd.revents;
}

int fopen_temporary(const char *path, FILE **_f, char **_temp_path) {
        FILE *f;
        char *t;
        int r, fd;

        assert(path);
        assert(_f);
        assert(_temp_path);

        r = tempfn_xxxxxx(path, NULL, &t);
        if (r < 0)
                return r;

        fd = mkostemp_safe(t, O_WRONLY|O_CLOEXEC);
        if (fd < 0) {
                free(t);
                return -errno;
        }

        f = fdopen(fd, "we");
        if (!f) {
                unlink_noerrno(t);
                free(t);
                safe_close(fd);
                return -errno;
        }

        *_f = f;
        *_temp_path = t;

        return 0;
}

int symlink_atomic(const char *from, const char *to) {
        _cleanup_free_ char *t = NULL;
        int r;

        assert(from);
        assert(to);

        r = tempfn_random(to, NULL, &t);
        if (r < 0)
                return r;

        if (symlink(from, t) < 0)
                return -errno;

        if (rename(t, to) < 0) {
                unlink_noerrno(t);
                return -errno;
        }

        return 0;
}

int symlink_idempotent(const char *from, const char *to) {
        _cleanup_free_ char *p = NULL;
        int r;

        assert(from);
        assert(to);

        if (symlink(from, to) < 0) {
                if (errno != EEXIST)
                        return -errno;

                r = readlink_malloc(to, &p);
                if (r < 0)
                        return r;

                if (!streq(p, from))
                        return -EINVAL;
        }

        return 0;
}

int mknod_atomic(const char *path, mode_t mode, dev_t dev) {
        _cleanup_free_ char *t = NULL;
        int r;

        assert(path);

        r = tempfn_random(path, NULL, &t);
        if (r < 0)
                return r;

        if (mknod(t, mode, dev) < 0)
                return -errno;

        if (rename(t, path) < 0) {
                unlink_noerrno(t);
                return -errno;
        }

        return 0;
}

int mkfifo_atomic(const char *path, mode_t mode) {
        _cleanup_free_ char *t = NULL;
        int r;

        assert(path);

        r = tempfn_random(path, NULL, &t);
        if (r < 0)
                return r;

        if (mkfifo(t, mode) < 0)
                return -errno;

        if (rename(t, path) < 0) {
                unlink_noerrno(t);
                return -errno;
        }

        return 0;
}

bool display_is_local(const char *display) {
        assert(display);

        return
                display[0] == ':' &&
                display[1] >= '0' &&
                display[1] <= '9';
}

int socket_from_display(const char *display, char **path) {
        size_t k;
        char *f, *c;

        assert(display);
        assert(path);

        if (!display_is_local(display))
                return -EINVAL;

        k = strspn(display+1, "0123456789");

        f = new(char, strlen("/tmp/.X11-unix/X") + k + 1);
        if (!f)
                return -ENOMEM;

        c = stpcpy(f, "/tmp/.X11-unix/X");
        memcpy(c, display+1, k);
        c[k] = 0;

        *path = f;

        return 0;
}

int get_user_creds(
                const char **username,
                uid_t *uid, gid_t *gid,
                const char **home,
                const char **shell) {

        struct passwd *p;
        uid_t u;

        assert(username);
        assert(*username);

        /* We enforce some special rules for uid=0: in order to avoid
         * NSS lookups for root we hardcode its data. */

        if (streq(*username, "root") || streq(*username, "0")) {
                *username = "root";

                if (uid)
                        *uid = 0;

                if (gid)
                        *gid = 0;

                if (home)
                        *home = "/root";

                if (shell)
                        *shell = "/bin/sh";

                return 0;
        }

        if (parse_uid(*username, &u) >= 0) {
                errno = 0;
                p = getpwuid(u);

                /* If there are multiple users with the same id, make
                 * sure to leave $USER to the configured value instead
                 * of the first occurrence in the database. However if
                 * the uid was configured by a numeric uid, then let's
                 * pick the real username from /etc/passwd. */
                if (p)
                        *username = p->pw_name;
        } else {
                errno = 0;
                p = getpwnam(*username);
        }

        if (!p)
                return errno > 0 ? -errno : -ESRCH;

        if (uid)
                *uid = p->pw_uid;

        if (gid)
                *gid = p->pw_gid;

        if (home)
                *home = p->pw_dir;

        if (shell)
                *shell = p->pw_shell;

        return 0;
}

char* uid_to_name(uid_t uid) {
        struct passwd *p;
        char *r;

        if (uid == 0)
                return strdup("root");

        p = getpwuid(uid);
        if (p)
                return strdup(p->pw_name);

        if (asprintf(&r, UID_FMT, uid) < 0)
                return NULL;

        return r;
}

char* gid_to_name(gid_t gid) {
        struct group *p;
        char *r;

        if (gid == 0)
                return strdup("root");

        p = getgrgid(gid);
        if (p)
                return strdup(p->gr_name);

        if (asprintf(&r, GID_FMT, gid) < 0)
                return NULL;

        return r;
}

int get_group_creds(const char **groupname, gid_t *gid) {
        struct group *g;
        gid_t id;

        assert(groupname);

        /* We enforce some special rules for gid=0: in order to avoid
         * NSS lookups for root we hardcode its data. */

        if (streq(*groupname, "root") || streq(*groupname, "0")) {
                *groupname = "root";

                if (gid)
                        *gid = 0;

                return 0;
        }

        if (parse_gid(*groupname, &id) >= 0) {
                errno = 0;
                g = getgrgid(id);

                if (g)
                        *groupname = g->gr_name;
        } else {
                errno = 0;
                g = getgrnam(*groupname);
        }

        if (!g)
                return errno > 0 ? -errno : -ESRCH;

        if (gid)
                *gid = g->gr_gid;

        return 0;
}

int in_gid(gid_t gid) {
        gid_t *gids;
        int ngroups_max, r, i;

        if (getgid() == gid)
                return 1;

        if (getegid() == gid)
                return 1;

        ngroups_max = sysconf(_SC_NGROUPS_MAX);
        assert(ngroups_max > 0);

        gids = alloca(sizeof(gid_t) * ngroups_max);

        r = getgroups(ngroups_max, gids);
        if (r < 0)
                return -errno;

        for (i = 0; i < r; i++)
                if (gids[i] == gid)
                        return 1;

        return 0;
}

int in_group(const char *name) {
        int r;
        gid_t gid;

        r = get_group_creds(&name, &gid);
        if (r < 0)
                return r;

        return in_gid(gid);
}

int glob_exists(const char *path) {
        _cleanup_globfree_ glob_t g = {};
        int k;

        assert(path);

        errno = 0;
        k = glob(path, GLOB_NOSORT|GLOB_BRACE, NULL, &g);

        if (k == GLOB_NOMATCH)
                return 0;
        else if (k == GLOB_NOSPACE)
                return -ENOMEM;
        else if (k == 0)
                return !strv_isempty(g.gl_pathv);
        else
                return errno ? -errno : -EIO;
}

int glob_extend(char ***strv, const char *path) {
        _cleanup_globfree_ glob_t g = {};
        int k;
        char **p;

        errno = 0;
        k = glob(path, GLOB_NOSORT|GLOB_BRACE, NULL, &g);

        if (k == GLOB_NOMATCH)
                return -ENOENT;
        else if (k == GLOB_NOSPACE)
                return -ENOMEM;
        else if (k != 0 || strv_isempty(g.gl_pathv))
                return errno ? -errno : -EIO;

        STRV_FOREACH(p, g.gl_pathv) {
                k = strv_extend(strv, *p);
                if (k < 0)
                        break;
        }

        return k;
}

int dirent_ensure_type(DIR *d, struct dirent *de) {
        struct stat st;

        assert(d);
        assert(de);

        if (de->d_type != DT_UNKNOWN)
                return 0;

        if (fstatat(dirfd(d), de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0)
                return -errno;

        de->d_type =
                S_ISREG(st.st_mode)  ? DT_REG  :
                S_ISDIR(st.st_mode)  ? DT_DIR  :
                S_ISLNK(st.st_mode)  ? DT_LNK  :
                S_ISFIFO(st.st_mode) ? DT_FIFO :
                S_ISSOCK(st.st_mode) ? DT_SOCK :
                S_ISCHR(st.st_mode)  ? DT_CHR  :
                S_ISBLK(st.st_mode)  ? DT_BLK  :
                                       DT_UNKNOWN;

        return 0;
}

int get_files_in_directory(const char *path, char ***list) {
        _cleanup_closedir_ DIR *d = NULL;
        size_t bufsize = 0, n = 0;
        _cleanup_strv_free_ char **l = NULL;

        assert(path);

        /* Returns all files in a directory in *list, and the number
         * of files as return value. If list is NULL returns only the
         * number. */

        d = opendir(path);
        if (!d)
                return -errno;

        for (;;) {
                struct dirent *de;

                errno = 0;
                de = readdir(d);
                if (!de && errno != 0)
                        return -errno;
                if (!de)
                        break;

                dirent_ensure_type(d, de);

                if (!dirent_is_file(de))
                        continue;

                if (list) {
                        /* one extra slot is needed for the terminating NULL */
                        if (!GREEDY_REALLOC(l, bufsize, n + 2))
                                return -ENOMEM;

                        l[n] = strdup(de->d_name);
                        if (!l[n])
                                return -ENOMEM;

                        l[++n] = NULL;
                } else
                        n++;
        }

        if (list) {
                *list = l;
                l = NULL; /* avoid freeing */
        }

        return n;
}

bool is_main_thread(void) {
        static thread_local int cached = 0;

        if (_unlikely_(cached == 0))
                cached = getpid() == gettid() ? 1 : -1;

        return cached > 0;
}

int block_get_whole_disk(dev_t d, dev_t *ret) {
        char *p, *s;
        int r;
        unsigned n, m;

        assert(ret);

        /* If it has a queue this is good enough for us */
        if (asprintf(&p, "/sys/dev/block/%u:%u/queue", major(d), minor(d)) < 0)
                return -ENOMEM;

        r = access(p, F_OK);
        free(p);

        if (r >= 0) {
                *ret = d;
                return 0;
        }

        /* If it is a partition find the originating device */
        if (asprintf(&p, "/sys/dev/block/%u:%u/partition", major(d), minor(d)) < 0)
                return -ENOMEM;

        r = access(p, F_OK);
        free(p);

        if (r < 0)
                return -ENOENT;

        /* Get parent dev_t */
        if (asprintf(&p, "/sys/dev/block/%u:%u/../dev", major(d), minor(d)) < 0)
                return -ENOMEM;

        r = read_one_line_file(p, &s);
        free(p);

        if (r < 0)
                return r;

        r = sscanf(s, "%u:%u", &m, &n);
        free(s);

        if (r != 2)
                return -EINVAL;

        /* Only return this if it is really good enough for us. */
        if (asprintf(&p, "/sys/dev/block/%u:%u/queue", m, n) < 0)
                return -ENOMEM;

        r = access(p, F_OK);
        free(p);

        if (r >= 0) {
                *ret = makedev(m, n);
                return 0;
        }

        return -ENOENT;
}

static const char *const ioprio_class_table[] = {
        [IOPRIO_CLASS_NONE] = "none",
        [IOPRIO_CLASS_RT] = "realtime",
        [IOPRIO_CLASS_BE] = "best-effort",
        [IOPRIO_CLASS_IDLE] = "idle"
};

DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(ioprio_class, int, INT_MAX);

static const char *const sigchld_code_table[] = {
        [CLD_EXITED] = "exited",
        [CLD_KILLED] = "killed",
        [CLD_DUMPED] = "dumped",
        [CLD_TRAPPED] = "trapped",
        [CLD_STOPPED] = "stopped",
        [CLD_CONTINUED] = "continued",
};

DEFINE_STRING_TABLE_LOOKUP(sigchld_code, int);

static const char *const log_facility_unshifted_table[LOG_NFACILITIES] = {
        [LOG_FAC(LOG_KERN)] = "kern",
        [LOG_FAC(LOG_USER)] = "user",
        [LOG_FAC(LOG_MAIL)] = "mail",
        [LOG_FAC(LOG_DAEMON)] = "daemon",
        [LOG_FAC(LOG_AUTH)] = "auth",
        [LOG_FAC(LOG_SYSLOG)] = "syslog",
        [LOG_FAC(LOG_LPR)] = "lpr",
        [LOG_FAC(LOG_NEWS)] = "news",
        [LOG_FAC(LOG_UUCP)] = "uucp",
        [LOG_FAC(LOG_CRON)] = "cron",
        [LOG_FAC(LOG_AUTHPRIV)] = "authpriv",
        [LOG_FAC(LOG_FTP)] = "ftp",
        [LOG_FAC(LOG_LOCAL0)] = "local0",
        [LOG_FAC(LOG_LOCAL1)] = "local1",
        [LOG_FAC(LOG_LOCAL2)] = "local2",
        [LOG_FAC(LOG_LOCAL3)] = "local3",
        [LOG_FAC(LOG_LOCAL4)] = "local4",
        [LOG_FAC(LOG_LOCAL5)] = "local5",
        [LOG_FAC(LOG_LOCAL6)] = "local6",
        [LOG_FAC(LOG_LOCAL7)] = "local7"
};

DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(log_facility_unshifted, int, LOG_FAC(~0));

bool log_facility_unshifted_is_valid(int facility) {
        return facility >= 0 && facility <= LOG_FAC(~0);
}

static const char *const log_level_table[] = {
        [LOG_EMERG] = "emerg",
        [LOG_ALERT] = "alert",
        [LOG_CRIT] = "crit",
        [LOG_ERR] = "err",
        [LOG_WARNING] = "warning",
        [LOG_NOTICE] = "notice",
        [LOG_INFO] = "info",
        [LOG_DEBUG] = "debug"
};

DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(log_level, int, LOG_DEBUG);

bool log_level_is_valid(int level) {
        return level >= 0 && level <= LOG_DEBUG;
}

static const char* const sched_policy_table[] = {
        [SCHED_OTHER] = "other",
        [SCHED_BATCH] = "batch",
        [SCHED_IDLE] = "idle",
        [SCHED_FIFO] = "fifo",
        [SCHED_RR] = "rr"
};

DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(sched_policy, int, INT_MAX);

static const char* const rlimit_table[_RLIMIT_MAX] = {
        [RLIMIT_CPU] = "LimitCPU",
        [RLIMIT_FSIZE] = "LimitFSIZE",
        [RLIMIT_DATA] = "LimitDATA",
        [RLIMIT_STACK] = "LimitSTACK",
        [RLIMIT_CORE] = "LimitCORE",
        [RLIMIT_RSS] = "LimitRSS",
        [RLIMIT_NOFILE] = "LimitNOFILE",
        [RLIMIT_AS] = "LimitAS",
        [RLIMIT_NPROC] = "LimitNPROC",
        [RLIMIT_MEMLOCK] = "LimitMEMLOCK",
        [RLIMIT_LOCKS] = "LimitLOCKS",
        [RLIMIT_SIGPENDING] = "LimitSIGPENDING",
        [RLIMIT_MSGQUEUE] = "LimitMSGQUEUE",
        [RLIMIT_NICE] = "LimitNICE",
        [RLIMIT_RTPRIO] = "LimitRTPRIO",
        [RLIMIT_RTTIME] = "LimitRTTIME"
};

DEFINE_STRING_TABLE_LOOKUP(rlimit, int);

static const char* const ip_tos_table[] = {
        [IPTOS_LOWDELAY] = "low-delay",
        [IPTOS_THROUGHPUT] = "throughput",
        [IPTOS_RELIABILITY] = "reliability",
        [IPTOS_LOWCOST] = "low-cost",
};

DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(ip_tos, int, 0xff);

bool kexec_loaded(void) {
       bool loaded = false;
       char *s;

       if (read_one_line_file("/sys/kernel/kexec_loaded", &s) >= 0) {
               if (s[0] == '1')
                       loaded = true;
               free(s);
       }
       return loaded;
}

int prot_from_flags(int flags) {

        switch (flags & O_ACCMODE) {

        case O_RDONLY:
                return PROT_READ;

        case O_WRONLY:
                return PROT_WRITE;

        case O_RDWR:
                return PROT_READ|PROT_WRITE;

        default:
                return -EINVAL;
        }
}

char *format_bytes(char *buf, size_t l, uint64_t t) {
        unsigned i;

        static const struct {
                const char *suffix;
                uint64_t factor;
        } table[] = {
                { "E", UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024) },
                { "P", UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024) },
                { "T", UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024) },
                { "G", UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024) },
                { "M", UINT64_C(1024)*UINT64_C(1024) },
                { "K", UINT64_C(1024) },
        };

        if (t == (uint64_t) -1)
                return NULL;

        for (i = 0; i < ELEMENTSOF(table); i++) {

                if (t >= table[i].factor) {
                        snprintf(buf, l,
                                 "%" PRIu64 ".%" PRIu64 "%s",
                                 t / table[i].factor,
                                 ((t*UINT64_C(10)) / table[i].factor) % UINT64_C(10),
                                 table[i].suffix);

                        goto finish;
                }
        }

        snprintf(buf, l, "%" PRIu64 "B", t);

finish:
        buf[l-1] = 0;
        return buf;

}

void* memdup(const void *p, size_t l) {
        void *r;

        assert(p);

        r = malloc(l);
        if (!r)
                return NULL;

        memcpy(r, p, l);
        return r;
}

int fd_inc_sndbuf(int fd, size_t n) {
        int r, value;
        socklen_t l = sizeof(value);

        r = getsockopt(fd, SOL_SOCKET, SO_SNDBUF, &value, &l);
        if (r >= 0 && l == sizeof(value) && (size_t) value >= n*2)
                return 0;

        /* If we have the privileges we will ignore the kernel limit. */

        value = (int) n;
        if (setsockopt(fd, SOL_SOCKET, SO_SNDBUFFORCE, &value, sizeof(value)) < 0)
                if (setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &value, sizeof(value)) < 0)
                        return -errno;

        return 1;
}

int fd_inc_rcvbuf(int fd, size_t n) {
        int r, value;
        socklen_t l = sizeof(value);

        r = getsockopt(fd, SOL_SOCKET, SO_RCVBUF, &value, &l);
        if (r >= 0 && l == sizeof(value) && (size_t) value >= n*2)
                return 0;

        /* If we have the privileges we will ignore the kernel limit. */

        value = (int) n;
        if (setsockopt(fd, SOL_SOCKET, SO_RCVBUFFORCE, &value, sizeof(value)) < 0)
                if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &value, sizeof(value)) < 0)
                        return -errno;
        return 1;
}

int fork_agent(pid_t *pid, const int except[], unsigned n_except, const char *path, ...) {
        bool stdout_is_tty, stderr_is_tty;
        pid_t parent_pid, agent_pid;
        sigset_t ss, saved_ss;
        unsigned n, i;
        va_list ap;
        char **l;

        assert(pid);
        assert(path);

        /* Spawns a temporary TTY agent, making sure it goes away when
         * we go away */

        parent_pid = getpid();

        /* First we temporarily block all signals, so that the new
         * child has them blocked initially. This way, we can be sure
         * that SIGTERMs are not lost we might send to the agent. */
        assert_se(sigfillset(&ss) >= 0);
        assert_se(sigprocmask(SIG_SETMASK, &ss, &saved_ss) >= 0);

        agent_pid = fork();
        if (agent_pid < 0) {
                assert_se(sigprocmask(SIG_SETMASK, &saved_ss, NULL) >= 0);
                return -errno;
        }

        if (agent_pid != 0) {
                assert_se(sigprocmask(SIG_SETMASK, &saved_ss, NULL) >= 0);
                *pid = agent_pid;
                return 0;
        }

        /* In the child:
         *
         * Make sure the agent goes away when the parent dies */
        if (prctl(PR_SET_PDEATHSIG, SIGTERM) < 0)
                _exit(EXIT_FAILURE);

        /* Make sure we actually can kill the agent, if we need to, in
         * case somebody invoked us from a shell script that trapped
         * SIGTERM or so... */
        (void) reset_all_signal_handlers();
        (void) reset_signal_mask();

        /* Check whether our parent died before we were able
         * to set the death signal and unblock the signals */
        if (getppid() != parent_pid)
                _exit(EXIT_SUCCESS);

        /* Don't leak fds to the agent */
        close_all_fds(except, n_except);

        stdout_is_tty = isatty(STDOUT_FILENO);
        stderr_is_tty = isatty(STDERR_FILENO);

        if (!stdout_is_tty || !stderr_is_tty) {
                int fd;

                /* Detach from stdout/stderr. and reopen
                 * /dev/tty for them. This is important to
                 * ensure that when systemctl is started via
                 * popen() or a similar call that expects to
                 * read EOF we actually do generate EOF and
                 * not delay this indefinitely by because we
                 * keep an unused copy of stdin around. */
                fd = open("/dev/tty", O_WRONLY);
                if (fd < 0) {
                        log_error_errno(errno, "Failed to open /dev/tty: %m");
                        _exit(EXIT_FAILURE);
                }

                if (!stdout_is_tty)
                        dup2(fd, STDOUT_FILENO);

                if (!stderr_is_tty)
                        dup2(fd, STDERR_FILENO);

                if (fd > 2)
                        close(fd);
        }

        /* Count arguments */
        va_start(ap, path);
        for (n = 0; va_arg(ap, char*); n++)
                ;
        va_end(ap);

        /* Allocate strv */
        l = alloca(sizeof(char *) * (n + 1));

        /* Fill in arguments */
        va_start(ap, path);
        for (i = 0; i <= n; i++)
                l[i] = va_arg(ap, char*);
        va_end(ap);

        execv(path, l);
        _exit(EXIT_FAILURE);
}

int setrlimit_closest(int resource, const struct rlimit *rlim) {
        struct rlimit highest, fixed;

        assert(rlim);

        if (setrlimit(resource, rlim) >= 0)
                return 0;

        if (errno != EPERM)
                return -errno;

        /* So we failed to set the desired setrlimit, then let's try
         * to get as close as we can */
        assert_se(getrlimit(resource, &highest) == 0);

        fixed.rlim_cur = MIN(rlim->rlim_cur, highest.rlim_max);
        fixed.rlim_max = MIN(rlim->rlim_max, highest.rlim_max);

        if (setrlimit(resource, &fixed) < 0)
                return -errno;

        return 0;
}

bool http_etag_is_valid(const char *etag) {
        if (isempty(etag))
                return false;

        if (!endswith(etag, "\""))
                return false;

        if (!startswith(etag, "\"") && !startswith(etag, "W/\""))
                return false;

        return true;
}

bool http_url_is_valid(const char *url) {
        const char *p;

        if (isempty(url))
                return false;

        p = startswith(url, "http://");
        if (!p)
                p = startswith(url, "https://");
        if (!p)
                return false;

        if (isempty(p))
                return false;

        return ascii_is_valid(p);
}

bool documentation_url_is_valid(const char *url) {
        const char *p;

        if (isempty(url))
                return false;

        if (http_url_is_valid(url))
                return true;

        p = startswith(url, "file:/");
        if (!p)
                p = startswith(url, "info:");
        if (!p)
                p = startswith(url, "man:");

        if (isempty(p))
                return false;

        return ascii_is_valid(p);
}

bool in_initrd(void) {
        static int saved = -1;
        struct statfs s;

        if (saved >= 0)
                return saved;

        /* We make two checks here:
         *
         * 1. the flag file /etc/initrd-release must exist
         * 2. the root file system must be a memory file system
         *
         * The second check is extra paranoia, since misdetecting an
         * initrd can have bad bad consequences due the initrd
         * emptying when transititioning to the main systemd.
         */

        saved = access("/etc/initrd-release", F_OK) >= 0 &&
                statfs("/", &s) >= 0 &&
                is_temporary_fs(&s);

        return saved;
}

int get_home_dir(char **_h) {
        struct passwd *p;
        const char *e;
        char *h;
        uid_t u;

        assert(_h);

        /* Take the user specified one */
        e = secure_getenv("HOME");
        if (e && path_is_absolute(e)) {
                h = strdup(e);
                if (!h)
                        return -ENOMEM;

                *_h = h;
                return 0;
        }

        /* Hardcode home directory for root to avoid NSS */
        u = getuid();
        if (u == 0) {
                h = strdup("/root");
                if (!h)
                        return -ENOMEM;

                *_h = h;
                return 0;
        }

        /* Check the database... */
        errno = 0;
        p = getpwuid(u);
        if (!p)
                return errno > 0 ? -errno : -ESRCH;

        if (!path_is_absolute(p->pw_dir))
                return -EINVAL;

        h = strdup(p->pw_dir);
        if (!h)
                return -ENOMEM;

        *_h = h;
        return 0;
}

int get_shell(char **_s) {
        struct passwd *p;
        const char *e;
        char *s;
        uid_t u;

        assert(_s);

        /* Take the user specified one */
        e = getenv("SHELL");
        if (e) {
                s = strdup(e);
                if (!s)
                        return -ENOMEM;

                *_s = s;
                return 0;
        }

        /* Hardcode home directory for root to avoid NSS */
        u = getuid();
        if (u == 0) {
                s = strdup("/bin/sh");
                if (!s)
                        return -ENOMEM;

                *_s = s;
                return 0;
        }

        /* Check the database... */
        errno = 0;
        p = getpwuid(u);
        if (!p)
                return errno > 0 ? -errno : -ESRCH;

        if (!path_is_absolute(p->pw_shell))
                return -EINVAL;

        s = strdup(p->pw_shell);
        if (!s)
                return -ENOMEM;

        *_s = s;
        return 0;
}

bool filename_is_valid(const char *p) {

        if (isempty(p))
                return false;

        if (strchr(p, '/'))
                return false;

        if (streq(p, "."))
                return false;

        if (streq(p, ".."))
                return false;

        if (strlen(p) > FILENAME_MAX)
                return false;

        return true;
}

bool string_is_safe(const char *p) {
        const char *t;

        if (!p)
                return false;

        for (t = p; *t; t++) {
                if (*t > 0 && *t < ' ')
                        return false;

                if (strchr("\\\"\'\x7f", *t))
                        return false;
        }

        return true;
}

bool path_is_safe(const char *p) {

        if (isempty(p))
                return false;

        if (streq(p, "..") || startswith(p, "../") || endswith(p, "/..") || strstr(p, "/../"))
                return false;

        if (strlen(p)+1 > PATH_MAX)
                return false;

        /* The following two checks are not really dangerous, but hey, they still are confusing */
        if (streq(p, ".") || startswith(p, "./") || endswith(p, "/.") || strstr(p, "/./"))
                return false;

        if (strstr(p, "//"))
                return false;

        return true;
}

/* hey glibc, APIs with callbacks without a user pointer are so useless */
void *xbsearch_r(const void *key, const void *base, size_t nmemb, size_t size,
                 int (*compar) (const void *, const void *, void *), void *arg) {
        size_t l, u, idx;
        const void *p;
        int comparison;

        l = 0;
        u = nmemb;
        while (l < u) {
                idx = (l + u) / 2;
                p = (void *)(((const char *) base) + (idx * size));
                comparison = compar(key, p, arg);
                if (comparison < 0)
                        u = idx;
                else if (comparison > 0)
                        l = idx + 1;
                else
                        return (void *)p;
        }
        return NULL;
}

void init_gettext(void) {
        setlocale(LC_ALL, "");
        textdomain(GETTEXT_PACKAGE);
}

bool is_locale_utf8(void) {
        const char *set;
        static int cached_answer = -1;

        if (cached_answer >= 0)
                goto out;

        if (!setlocale(LC_ALL, "")) {
                cached_answer = true;
                goto out;
        }

        set = nl_langinfo(CODESET);
        if (!set) {
                cached_answer = true;
                goto out;
        }

        if (streq(set, "UTF-8")) {
                cached_answer = true;
                goto out;
        }

        /* For LC_CTYPE=="C" return true, because CTYPE is effectly
         * unset and everything can do to UTF-8 nowadays. */
        set = setlocale(LC_CTYPE, NULL);
        if (!set) {
                cached_answer = true;
                goto out;
        }

        /* Check result, but ignore the result if C was set
         * explicitly. */
        cached_answer =
                STR_IN_SET(set, "C", "POSIX") &&
                !getenv("LC_ALL") &&
                !getenv("LC_CTYPE") &&
                !getenv("LANG");

out:
        return (bool) cached_answer;
}

const char *draw_special_char(DrawSpecialChar ch) {
        static const char *draw_table[2][_DRAW_SPECIAL_CHAR_MAX] = {

                /* UTF-8 */ {
                        [DRAW_TREE_VERTICAL]      = "\342\224\202 ",            /* │  */
                        [DRAW_TREE_BRANCH]        = "\342\224\234\342\224\200", /* ├─ */
                        [DRAW_TREE_RIGHT]         = "\342\224\224\342\224\200", /* └─ */
                        [DRAW_TREE_SPACE]         = "  ",                       /*    */
                        [DRAW_TRIANGULAR_BULLET]  = "\342\200\243",             /* ‣ */
                        [DRAW_BLACK_CIRCLE]       = "\342\227\217",             /* ● */
                        [DRAW_ARROW]              = "\342\206\222",             /* → */
                        [DRAW_DASH]               = "\342\200\223",             /* – */
                },

                /* ASCII fallback */ {
                        [DRAW_TREE_VERTICAL]      = "| ",
                        [DRAW_TREE_BRANCH]        = "|-",
                        [DRAW_TREE_RIGHT]         = "`-",
                        [DRAW_TREE_SPACE]         = "  ",
                        [DRAW_TRIANGULAR_BULLET]  = ">",
                        [DRAW_BLACK_CIRCLE]       = "*",
                        [DRAW_ARROW]              = "->",
                        [DRAW_DASH]               = "-",
                }
        };

        return draw_table[!is_locale_utf8()][ch];
}

int on_ac_power(void) {
        bool found_offline = false, found_online = false;
        _cleanup_closedir_ DIR *d = NULL;

        d = opendir("/sys/class/power_supply");
        if (!d)
                return errno == ENOENT ? true : -errno;

        for (;;) {
                struct dirent *de;
                _cleanup_close_ int fd = -1, device = -1;
                char contents[6];
                ssize_t n;

                errno = 0;
                de = readdir(d);
                if (!de && errno != 0)
                        return -errno;

                if (!de)
                        break;

                if (hidden_file(de->d_name))
                        continue;

                device = openat(dirfd(d), de->d_name, O_DIRECTORY|O_RDONLY|O_CLOEXEC|O_NOCTTY);
                if (device < 0) {
                        if (errno == ENOENT || errno == ENOTDIR)
                                continue;

                        return -errno;
                }

                fd = openat(device, "type", O_RDONLY|O_CLOEXEC|O_NOCTTY);
                if (fd < 0) {
                        if (errno == ENOENT)
                                continue;

                        return -errno;
                }

                n = read(fd, contents, sizeof(contents));
                if (n < 0)
                        return -errno;

                if (n != 6 || memcmp(contents, "Mains\n", 6))
                        continue;

                safe_close(fd);
                fd = openat(device, "online", O_RDONLY|O_CLOEXEC|O_NOCTTY);
                if (fd < 0) {
                        if (errno == ENOENT)
                                continue;

                        return -errno;
                }

                n = read(fd, contents, sizeof(contents));
                if (n < 0)
                        return -errno;

                if (n != 2 || contents[1] != '\n')
                        return -EIO;

                if (contents[0] == '1') {
                        found_online = true;
                        break;
                } else if (contents[0] == '0')
                        found_offline = true;
                else
                        return -EIO;
        }

        return found_online || !found_offline;
}

static int search_and_fopen_internal(const char *path, const char *mode, const char *root, char **search, FILE **_f) {
        char **i;

        assert(path);
        assert(mode);
        assert(_f);

        if (!path_strv_resolve_uniq(search, root))
                return -ENOMEM;

        STRV_FOREACH(i, search) {
                _cleanup_free_ char *p = NULL;
                FILE *f;

                if (root)
                        p = strjoin(root, *i, "/", path, NULL);
                else
                        p = strjoin(*i, "/", path, NULL);
                if (!p)
                        return -ENOMEM;

                f = fopen(p, mode);
                if (f) {
                        *_f = f;
                        return 0;
                }

                if (errno != ENOENT)
                        return -errno;
        }

        return -ENOENT;
}

int search_and_fopen(const char *path, const char *mode, const char *root, const char **search, FILE **_f) {
        _cleanup_strv_free_ char **copy = NULL;

        assert(path);
        assert(mode);
        assert(_f);

        if (path_is_absolute(path)) {
                FILE *f;

                f = fopen(path, mode);
                if (f) {
                        *_f = f;
                        return 0;
                }

                return -errno;
        }

        copy = strv_copy((char**) search);
        if (!copy)
                return -ENOMEM;

        return search_and_fopen_internal(path, mode, root, copy, _f);
}

int search_and_fopen_nulstr(const char *path, const char *mode, const char *root, const char *search, FILE **_f) {
        _cleanup_strv_free_ char **s = NULL;

        if (path_is_absolute(path)) {
                FILE *f;

                f = fopen(path, mode);
                if (f) {
                        *_f = f;
                        return 0;
                }

                return -errno;
        }

        s = strv_split_nulstr(search);
        if (!s)
                return -ENOMEM;

        return search_and_fopen_internal(path, mode, root, s, _f);
}

void* greedy_realloc(void **p, size_t *allocated, size_t need, size_t size) {
        size_t a, newalloc;
        void *q;

        assert(p);
        assert(allocated);

        if (*allocated >= need)
                return *p;

        newalloc = MAX(need * 2, 64u / size);
        a = newalloc * size;

        /* check for overflows */
        if (a < size * need)
                return NULL;

        q = realloc(*p, a);
        if (!q)
                return NULL;

        *p = q;
        *allocated = newalloc;
        return q;
}

void* greedy_realloc0(void **p, size_t *allocated, size_t need, size_t size) {
        size_t prev;
        uint8_t *q;

        assert(p);
        assert(allocated);

        prev = *allocated;

        q = greedy_realloc(p, allocated, need, size);
        if (!q)
                return NULL;

        if (*allocated > prev)
                memzero(q + prev * size, (*allocated - prev) * size);

        return q;
}

bool id128_is_valid(const char *s) {
        size_t i, l;

        l = strlen(s);
        if (l == 32) {

                /* Simple formatted 128bit hex string */

                for (i = 0; i < l; i++) {
                        char c = s[i];

                        if (!(c >= '0' && c <= '9') &&
                            !(c >= 'a' && c <= 'z') &&
                            !(c >= 'A' && c <= 'Z'))
                                return false;
                }

        } else if (l == 36) {

                /* Formatted UUID */

                for (i = 0; i < l; i++) {
                        char c = s[i];

                        if ((i == 8 || i == 13 || i == 18 || i == 23)) {
                                if (c != '-')
                                        return false;
                        } else {
                                if (!(c >= '0' && c <= '9') &&
                                    !(c >= 'a' && c <= 'z') &&
                                    !(c >= 'A' && c <= 'Z'))
                                        return false;
                        }
                }

        } else
                return false;

        return true;
}

int shall_restore_state(void) {
        _cleanup_free_ char *value = NULL;
        int r;

        r = get_proc_cmdline_key("systemd.restore_state=", &value);
        if (r < 0)
                return r;
        if (r == 0)
                return true;

        return parse_boolean(value) != 0;
}

int proc_cmdline(char **ret) {
        assert(ret);

        if (detect_container() > 0)
                return get_process_cmdline(1, 0, false, ret);
        else
                return read_one_line_file("/proc/cmdline", ret);
}

int parse_proc_cmdline(int (*parse_item)(const char *key, const char *value)) {
        _cleanup_free_ char *line = NULL;
        const char *p;
        int r;

        assert(parse_item);

        r = proc_cmdline(&line);
        if (r < 0)
                return r;

        p = line;
        for (;;) {
                _cleanup_free_ char *word = NULL;
                char *value = NULL;

                r = extract_first_word(&p, &word, NULL, EXTRACT_QUOTES|EXTRACT_RELAX);
                if (r < 0)
                        return r;
                if (r == 0)
                        break;

                /* Filter out arguments that are intended only for the
                 * initrd */
                if (!in_initrd() && startswith(word, "rd."))
                        continue;

                value = strchr(word, '=');
                if (value)
                        *(value++) = 0;

                r = parse_item(word, value);
                if (r < 0)
                        return r;
        }

        return 0;
}

int get_proc_cmdline_key(const char *key, char **value) {
        _cleanup_free_ char *line = NULL, *ret = NULL;
        bool found = false;
        const char *p;
        int r;

        assert(key);

        r = proc_cmdline(&line);
        if (r < 0)
                return r;

        p = line;
        for (;;) {
                _cleanup_free_ char *word = NULL;
                const char *e;

                r = extract_first_word(&p, &word, NULL, EXTRACT_QUOTES|EXTRACT_RELAX);
                if (r < 0)
                        return r;
                if (r == 0)
                        break;

                /* Filter out arguments that are intended only for the
                 * initrd */
                if (!in_initrd() && startswith(word, "rd."))
                        continue;

                if (value) {
                        e = startswith(word, key);
                        if (!e)
                                continue;

                        r = free_and_strdup(&ret, e);
                        if (r < 0)
                                return r;

                        found = true;
                } else {
                        if (streq(word, key))
                                found = true;
                }
        }

        if (value) {
                *value = ret;
                ret = NULL;
        }

        return found;

}

int container_get_leader(const char *machine, pid_t *pid) {
        _cleanup_free_ char *s = NULL, *class = NULL;
        const char *p;
        pid_t leader;
        int r;

        assert(machine);
        assert(pid);

        if (!machine_name_is_valid(machine))
                return -EINVAL;

        p = strjoina("/run/systemd/machines/", machine);
        r = parse_env_file(p, NEWLINE, "LEADER", &s, "CLASS", &class, NULL);
        if (r == -ENOENT)
                return -EHOSTDOWN;
        if (r < 0)
                return r;
        if (!s)
                return -EIO;

        if (!streq_ptr(class, "container"))
                return -EIO;

        r = parse_pid(s, &leader);
        if (r < 0)
                return r;
        if (leader <= 1)
                return -EIO;

        *pid = leader;
        return 0;
}

int namespace_open(pid_t pid, int *pidns_fd, int *mntns_fd, int *netns_fd, int *userns_fd, int *root_fd) {
        _cleanup_close_ int pidnsfd = -1, mntnsfd = -1, netnsfd = -1, usernsfd = -1;
        int rfd = -1;

        assert(pid >= 0);

        if (mntns_fd) {
                const char *mntns;

                mntns = procfs_file_alloca(pid, "ns/mnt");
                mntnsfd = open(mntns, O_RDONLY|O_NOCTTY|O_CLOEXEC);
                if (mntnsfd < 0)
                        return -errno;
        }

        if (pidns_fd) {
                const char *pidns;

                pidns = procfs_file_alloca(pid, "ns/pid");
                pidnsfd = open(pidns, O_RDONLY|O_NOCTTY|O_CLOEXEC);
                if (pidnsfd < 0)
                        return -errno;
        }

        if (netns_fd) {
                const char *netns;

                netns = procfs_file_alloca(pid, "ns/net");
                netnsfd = open(netns, O_RDONLY|O_NOCTTY|O_CLOEXEC);
                if (netnsfd < 0)
                        return -errno;
        }

        if (userns_fd) {
                const char *userns;

                userns = procfs_file_alloca(pid, "ns/user");
                usernsfd = open(userns, O_RDONLY|O_NOCTTY|O_CLOEXEC);
                if (usernsfd < 0 && errno != ENOENT)
                        return -errno;
        }

        if (root_fd) {
                const char *root;

                root = procfs_file_alloca(pid, "root");
                rfd = open(root, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY);
                if (rfd < 0)
                        return -errno;
        }

        if (pidns_fd)
                *pidns_fd = pidnsfd;

        if (mntns_fd)
                *mntns_fd = mntnsfd;

        if (netns_fd)
                *netns_fd = netnsfd;

        if (userns_fd)
                *userns_fd = usernsfd;

        if (root_fd)
                *root_fd = rfd;

        pidnsfd = mntnsfd = netnsfd = usernsfd = -1;

        return 0;
}

int namespace_enter(int pidns_fd, int mntns_fd, int netns_fd, int userns_fd, int root_fd) {
        if (userns_fd >= 0) {
                /* Can't setns to your own userns, since then you could
                 * escalate from non-root to root in your own namespace, so
                 * check if namespaces equal before attempting to enter. */
                _cleanup_free_ char *userns_fd_path = NULL;
                int r;
                if (asprintf(&userns_fd_path, "/proc/self/fd/%d", userns_fd) < 0)
                        return -ENOMEM;

                r = files_same(userns_fd_path, "/proc/self/ns/user");
                if (r < 0)
                        return r;
                if (r)
                        userns_fd = -1;
        }

        if (pidns_fd >= 0)
                if (setns(pidns_fd, CLONE_NEWPID) < 0)
                        return -errno;

        if (mntns_fd >= 0)
                if (setns(mntns_fd, CLONE_NEWNS) < 0)
                        return -errno;

        if (netns_fd >= 0)
                if (setns(netns_fd, CLONE_NEWNET) < 0)
                        return -errno;

        if (userns_fd >= 0)
                if (setns(userns_fd, CLONE_NEWUSER) < 0)
                        return -errno;

        if (root_fd >= 0) {
                if (fchdir(root_fd) < 0)
                        return -errno;

                if (chroot(".") < 0)
                        return -errno;
        }

        return reset_uid_gid();
}

int getpeercred(int fd, struct ucred *ucred) {
        socklen_t n = sizeof(struct ucred);
        struct ucred u;
        int r;

        assert(fd >= 0);
        assert(ucred);

        r = getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &u, &n);
        if (r < 0)
                return -errno;

        if (n != sizeof(struct ucred))
                return -EIO;

        /* Check if the data is actually useful and not suppressed due
         * to namespacing issues */
        if (u.pid <= 0)
                return -ENODATA;
        if (u.uid == UID_INVALID)
                return -ENODATA;
        if (u.gid == GID_INVALID)
                return -ENODATA;

        *ucred = u;
        return 0;
}

int getpeersec(int fd, char **ret) {
        socklen_t n = 64;
        char *s;
        int r;

        assert(fd >= 0);
        assert(ret);

        s = new0(char, n);
        if (!s)
                return -ENOMEM;

        r = getsockopt(fd, SOL_SOCKET, SO_PEERSEC, s, &n);
        if (r < 0) {
                free(s);

                if (errno != ERANGE)
                        return -errno;

                s = new0(char, n);
                if (!s)
                        return -ENOMEM;

                r = getsockopt(fd, SOL_SOCKET, SO_PEERSEC, s, &n);
                if (r < 0) {
                        free(s);
                        return -errno;
                }
        }

        if (isempty(s)) {
                free(s);
                return -EOPNOTSUPP;
        }

        *ret = s;
        return 0;
}

/* This is much like like mkostemp() but is subject to umask(). */
int mkostemp_safe(char *pattern, int flags) {
        _cleanup_umask_ mode_t u;
        int fd;

        assert(pattern);

        u = umask(077);

        fd = mkostemp(pattern, flags);
        if (fd < 0)
                return -errno;

        return fd;
}

int open_tmpfile(const char *path, int flags) {
        char *p;
        int fd;

        assert(path);

#ifdef O_TMPFILE
        /* Try O_TMPFILE first, if it is supported */
        fd = open(path, flags|O_TMPFILE|O_EXCL, S_IRUSR|S_IWUSR);
        if (fd >= 0)
                return fd;
#endif

        /* Fall back to unguessable name + unlinking */
        p = strjoina(path, "/systemd-tmp-XXXXXX");

        fd = mkostemp_safe(p, flags);
        if (fd < 0)
                return fd;

        unlink(p);
        return fd;
}

int fd_warn_permissions(const char *path, int fd) {
        struct stat st;

        if (fstat(fd, &st) < 0)
                return -errno;

        if (st.st_mode & 0111)
                log_warning("Configuration file %s is marked executable. Please remove executable permission bits. Proceeding anyway.", path);

        if (st.st_mode & 0002)
                log_warning("Configuration file %s is marked world-writable. Please remove world writability permission bits. Proceeding anyway.", path);

        if (getpid() == 1 && (st.st_mode & 0044) != 0044)
                log_warning("Configuration file %s is marked world-inaccessible. This has no effect as configuration data is accessible via APIs without restrictions. Proceeding anyway.", path);

        return 0;
}

unsigned long personality_from_string(const char *p) {

        /* Parse a personality specifier. We introduce our own
         * identifiers that indicate specific ABIs, rather than just
         * hints regarding the register size, since we want to keep
         * things open for multiple locally supported ABIs for the
         * same register size. We try to reuse the ABI identifiers
         * used by libseccomp. */

#if defined(__x86_64__)

        if (streq(p, "x86"))
                return PER_LINUX32;

        if (streq(p, "x86-64"))
                return PER_LINUX;

#elif defined(__i386__)

        if (streq(p, "x86"))
                return PER_LINUX;

#elif defined(__s390x__)

        if (streq(p, "s390"))
                return PER_LINUX32;

        if (streq(p, "s390x"))
                return PER_LINUX;

#elif defined(__s390__)

        if (streq(p, "s390"))
                return PER_LINUX;
#endif

        return PERSONALITY_INVALID;
}

const char* personality_to_string(unsigned long p) {

#if defined(__x86_64__)

        if (p == PER_LINUX32)
                return "x86";

        if (p == PER_LINUX)
                return "x86-64";

#elif defined(__i386__)

        if (p == PER_LINUX)
                return "x86";

#elif defined(__s390x__)

        if (p == PER_LINUX)
                return "s390x";

        if (p == PER_LINUX32)
                return "s390";

#elif defined(__s390__)

        if (p == PER_LINUX)
                return "s390";

#endif

        return NULL;
}

uint64_t physical_memory(void) {
        long mem;

        /* We return this as uint64_t in case we are running as 32bit
         * process on a 64bit kernel with huge amounts of memory */

        mem = sysconf(_SC_PHYS_PAGES);
        assert(mem > 0);

        return (uint64_t) mem * (uint64_t) page_size();
}

void hexdump(FILE *f, const void *p, size_t s) {
        const uint8_t *b = p;
        unsigned n = 0;

        assert(s == 0 || b);

        while (s > 0) {
                size_t i;

                fprintf(f, "%04x  ", n);

                for (i = 0; i < 16; i++) {

                        if (i >= s)
                                fputs("   ", f);
                        else
                                fprintf(f, "%02x ", b[i]);

                        if (i == 7)
                                fputc(' ', f);
                }

                fputc(' ', f);

                for (i = 0; i < 16; i++) {

                        if (i >= s)
                                fputc(' ', f);
                        else
                                fputc(isprint(b[i]) ? (char) b[i] : '.', f);
                }

                fputc('\n', f);

                if (s < 16)
                        break;

                n += 16;
                b += 16;
                s -= 16;
        }
}

int update_reboot_param_file(const char *param) {
        int r = 0;

        if (param) {
                r = write_string_file(REBOOT_PARAM_FILE, param, WRITE_STRING_FILE_CREATE);
                if (r < 0)
                        return log_error_errno(r, "Failed to write reboot param to "REBOOT_PARAM_FILE": %m");
        } else
                (void) unlink(REBOOT_PARAM_FILE);

        return 0;
}

int umount_recursive(const char *prefix, int flags) {
        bool again;
        int n = 0, r;

        /* Try to umount everything recursively below a
         * directory. Also, take care of stacked mounts, and keep
         * unmounting them until they are gone. */

        do {
                _cleanup_fclose_ FILE *proc_self_mountinfo = NULL;

                again = false;
                r = 0;

                proc_self_mountinfo = fopen("/proc/self/mountinfo", "re");
                if (!proc_self_mountinfo)
                        return -errno;

                for (;;) {
                        _cleanup_free_ char *path = NULL, *p = NULL;
                        int k;

                        k = fscanf(proc_self_mountinfo,
                                   "%*s "       /* (1) mount id */
                                   "%*s "       /* (2) parent id */
                                   "%*s "       /* (3) major:minor */
                                   "%*s "       /* (4) root */
                                   "%ms "       /* (5) mount point */
                                   "%*s"        /* (6) mount options */
                                   "%*[^-]"     /* (7) optional fields */
                                   "- "         /* (8) separator */
                                   "%*s "       /* (9) file system type */
                                   "%*s"        /* (10) mount source */
                                   "%*s"        /* (11) mount options 2 */
                                   "%*[^\n]",   /* some rubbish at the end */
                                   &path);
                        if (k != 1) {
                                if (k == EOF)
                                        break;

                                continue;
                        }

                        r = cunescape(path, UNESCAPE_RELAX, &p);
                        if (r < 0)
                                return r;

                        if (!path_startswith(p, prefix))
                                continue;

                        if (umount2(p, flags) < 0) {
                                r = -errno;
                                continue;
                        }

                        again = true;
                        n++;

                        break;
                }

        } while (again);

        return r ? r : n;
}

static int get_mount_flags(const char *path, unsigned long *flags) {
        struct statvfs buf;

        if (statvfs(path, &buf) < 0)
                return -errno;
        *flags = buf.f_flag;
        return 0;
}

int bind_remount_recursive(const char *prefix, bool ro) {
        _cleanup_set_free_free_ Set *done = NULL;
        _cleanup_free_ char *cleaned = NULL;
        int r;

        /* Recursively remount a directory (and all its submounts)
         * read-only or read-write. If the directory is already
         * mounted, we reuse the mount and simply mark it
         * MS_BIND|MS_RDONLY (or remove the MS_RDONLY for read-write
         * operation). If it isn't we first make it one. Afterwards we
         * apply MS_BIND|MS_RDONLY (or remove MS_RDONLY) to all
         * submounts we can access, too. When mounts are stacked on
         * the same mount point we only care for each individual
         * "top-level" mount on each point, as we cannot
         * influence/access the underlying mounts anyway. We do not
         * have any effect on future submounts that might get
         * propagated, they migt be writable. This includes future
         * submounts that have been triggered via autofs. */

        cleaned = strdup(prefix);
        if (!cleaned)
                return -ENOMEM;

        path_kill_slashes(cleaned);

        done = set_new(&string_hash_ops);
        if (!done)
                return -ENOMEM;

        for (;;) {
                _cleanup_fclose_ FILE *proc_self_mountinfo = NULL;
                _cleanup_set_free_free_ Set *todo = NULL;
                bool top_autofs = false;
                char *x;
                unsigned long orig_flags;

                todo = set_new(&string_hash_ops);
                if (!todo)
                        return -ENOMEM;

                proc_self_mountinfo = fopen("/proc/self/mountinfo", "re");
                if (!proc_self_mountinfo)
                        return -errno;

                for (;;) {
                        _cleanup_free_ char *path = NULL, *p = NULL, *type = NULL;
                        int k;

                        k = fscanf(proc_self_mountinfo,
                                   "%*s "       /* (1) mount id */
                                   "%*s "       /* (2) parent id */
                                   "%*s "       /* (3) major:minor */
                                   "%*s "       /* (4) root */
                                   "%ms "       /* (5) mount point */
                                   "%*s"        /* (6) mount options (superblock) */
                                   "%*[^-]"     /* (7) optional fields */
                                   "- "         /* (8) separator */
                                   "%ms "       /* (9) file system type */
                                   "%*s"        /* (10) mount source */
                                   "%*s"        /* (11) mount options (bind mount) */
                                   "%*[^\n]",   /* some rubbish at the end */
                                   &path,
                                   &type);
                        if (k != 2) {
                                if (k == EOF)
                                        break;

                                continue;
                        }

                        r = cunescape(path, UNESCAPE_RELAX, &p);
                        if (r < 0)
                                return r;

                        /* Let's ignore autofs mounts.  If they aren't
                         * triggered yet, we want to avoid triggering
                         * them, as we don't make any guarantees for
                         * future submounts anyway.  If they are
                         * already triggered, then we will find
                         * another entry for this. */
                        if (streq(type, "autofs")) {
                                top_autofs = top_autofs || path_equal(cleaned, p);
                                continue;
                        }

                        if (path_startswith(p, cleaned) &&
                            !set_contains(done, p)) {

                                r = set_consume(todo, p);
                                p = NULL;

                                if (r == -EEXIST)
                                        continue;
                                if (r < 0)
                                        return r;
                        }
                }

                /* If we have no submounts to process anymore and if
                 * the root is either already done, or an autofs, we
                 * are done */
                if (set_isempty(todo) &&
                    (top_autofs || set_contains(done, cleaned)))
                        return 0;

                if (!set_contains(done, cleaned) &&
                    !set_contains(todo, cleaned)) {
                        /* The prefix directory itself is not yet a
                         * mount, make it one. */
                        if (mount(cleaned, cleaned, NULL, MS_BIND|MS_REC, NULL) < 0)
                                return -errno;

                        orig_flags = 0;
                        (void) get_mount_flags(cleaned, &orig_flags);
                        orig_flags &= ~MS_RDONLY;

                        if (mount(NULL, prefix, NULL, orig_flags|MS_BIND|MS_REMOUNT|(ro ? MS_RDONLY : 0), NULL) < 0)
                                return -errno;

                        x = strdup(cleaned);
                        if (!x)
                                return -ENOMEM;

                        r = set_consume(done, x);
                        if (r < 0)
                                return r;
                }

                while ((x = set_steal_first(todo))) {

                        r = set_consume(done, x);
                        if (r == -EEXIST || r == 0)
                                continue;
                        if (r < 0)
                                return r;

                        /* Try to reuse the original flag set, but
                         * don't care for errors, in case of
                         * obstructed mounts */
                        orig_flags = 0;
                        (void) get_mount_flags(x, &orig_flags);
                        orig_flags &= ~MS_RDONLY;

                        if (mount(NULL, x, NULL, orig_flags|MS_BIND|MS_REMOUNT|(ro ? MS_RDONLY : 0), NULL) < 0) {

                                /* Deal with mount points that are
                                 * obstructed by a later mount */

                                if (errno != ENOENT)
                                        return -errno;
                        }

                }
        }
}

int fflush_and_check(FILE *f) {
        assert(f);

        errno = 0;
        fflush(f);

        if (ferror(f))
                return errno ? -errno : -EIO;

        return 0;
}

int tempfn_xxxxxx(const char *p, const char *extra, char **ret) {
        const char *fn;
        char *t;

        assert(p);
        assert(ret);

        /*
         * Turns this:
         *         /foo/bar/waldo
         *
         * Into this:
         *         /foo/bar/.#<extra>waldoXXXXXX
         */

        fn = basename(p);
        if (!filename_is_valid(fn))
                return -EINVAL;

        if (extra == NULL)
                extra = "";

        t = new(char, strlen(p) + 2 + strlen(extra) + 6 + 1);
        if (!t)
                return -ENOMEM;

        strcpy(stpcpy(stpcpy(stpcpy(mempcpy(t, p, fn - p), ".#"), extra), fn), "XXXXXX");

        *ret = path_kill_slashes(t);
        return 0;
}

int tempfn_random(const char *p, const char *extra, char **ret) {
        const char *fn;
        char *t, *x;
        uint64_t u;
        unsigned i;

        assert(p);
        assert(ret);

        /*
         * Turns this:
         *         /foo/bar/waldo
         *
         * Into this:
         *         /foo/bar/.#<extra>waldobaa2a261115984a9
         */

        fn = basename(p);
        if (!filename_is_valid(fn))
                return -EINVAL;

        if (!extra)
                extra = "";

        t = new(char, strlen(p) + 2 + strlen(extra) + 16 + 1);
        if (!t)
                return -ENOMEM;

        x = stpcpy(stpcpy(stpcpy(mempcpy(t, p, fn - p), ".#"), extra), fn);

        u = random_u64();
        for (i = 0; i < 16; i++) {
                *(x++) = hexchar(u & 0xF);
                u >>= 4;
        }

        *x = 0;

        *ret = path_kill_slashes(t);
        return 0;
}

int tempfn_random_child(const char *p, const char *extra, char **ret) {
        char *t, *x;
        uint64_t u;
        unsigned i;

        assert(p);
        assert(ret);

        /* Turns this:
         *         /foo/bar/waldo
         * Into this:
         *         /foo/bar/waldo/.#<extra>3c2b6219aa75d7d0
         */

        if (!extra)
                extra = "";

        t = new(char, strlen(p) + 3 + strlen(extra) + 16 + 1);
        if (!t)
                return -ENOMEM;

        x = stpcpy(stpcpy(stpcpy(t, p), "/.#"), extra);

        u = random_u64();
        for (i = 0; i < 16; i++) {
                *(x++) = hexchar(u & 0xF);
                u >>= 4;
        }

        *x = 0;

        *ret = path_kill_slashes(t);
        return 0;
}

int take_password_lock(const char *root) {

        struct flock flock = {
                .l_type = F_WRLCK,
                .l_whence = SEEK_SET,
                .l_start = 0,
                .l_len = 0,
        };

        const char *path;
        int fd, r;

        /* This is roughly the same as lckpwdf(), but not as awful. We
         * don't want to use alarm() and signals, hence we implement
         * our own trivial version of this.
         *
         * Note that shadow-utils also takes per-database locks in
         * addition to lckpwdf(). However, we don't given that they
         * are redundant as they they invoke lckpwdf() first and keep
         * it during everything they do. The per-database locks are
         * awfully racy, and thus we just won't do them. */

        if (root)
                path = strjoina(root, "/etc/.pwd.lock");
        else
                path = "/etc/.pwd.lock";

        fd = open(path, O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, 0600);
        if (fd < 0)
                return -errno;

        r = fcntl(fd, F_SETLKW, &flock);
        if (r < 0) {
                safe_close(fd);
                return -errno;
        }

        return fd;
}

int is_symlink(const char *path) {
        struct stat info;

        if (lstat(path, &info) < 0)
                return -errno;

        return !!S_ISLNK(info.st_mode);
}

int is_dir(const char* path, bool follow) {
        struct stat st;
        int r;

        if (follow)
                r = stat(path, &st);
        else
                r = lstat(path, &st);
        if (r < 0)
                return -errno;

        return !!S_ISDIR(st.st_mode);
}

int is_device_node(const char *path) {
        struct stat info;

        if (lstat(path, &info) < 0)
                return -errno;

        return !!(S_ISBLK(info.st_mode) || S_ISCHR(info.st_mode));
}

ssize_t fgetxattrat_fake(int dirfd, const char *filename, const char *attribute, void *value, size_t size, int flags) {
        char fn[strlen("/proc/self/fd/") + DECIMAL_STR_MAX(int) + 1];
        _cleanup_close_ int fd = -1;
        ssize_t l;

        /* The kernel doesn't have a fgetxattrat() command, hence let's emulate one */

        fd = openat(dirfd, filename, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_PATH|(flags & AT_SYMLINK_NOFOLLOW ? O_NOFOLLOW : 0));
        if (fd < 0)
                return -errno;

        xsprintf(fn, "/proc/self/fd/%i", fd);

        l = getxattr(fn, attribute, value, size);
        if (l < 0)
                return -errno;

        return l;
}

static int parse_crtime(le64_t le, usec_t *usec) {
        uint64_t u;

        assert(usec);

        u = le64toh(le);
        if (u == 0 || u == (uint64_t) -1)
                return -EIO;

        *usec = (usec_t) u;
        return 0;
}

int fd_getcrtime(int fd, usec_t *usec) {
        le64_t le;
        ssize_t n;

        assert(fd >= 0);
        assert(usec);

        /* Until Linux gets a real concept of birthtime/creation time,
         * let's fake one with xattrs */

        n = fgetxattr(fd, "user.crtime_usec", &le, sizeof(le));
        if (n < 0)
                return -errno;
        if (n != sizeof(le))
                return -EIO;

        return parse_crtime(le, usec);
}

int fd_getcrtime_at(int dirfd, const char *name, usec_t *usec, int flags) {
        le64_t le;
        ssize_t n;

        n = fgetxattrat_fake(dirfd, name, "user.crtime_usec", &le, sizeof(le), flags);
        if (n < 0)
                return -errno;
        if (n != sizeof(le))
                return -EIO;

        return parse_crtime(le, usec);
}

int path_getcrtime(const char *p, usec_t *usec) {
        le64_t le;
        ssize_t n;

        assert(p);
        assert(usec);

        n = getxattr(p, "user.crtime_usec", &le, sizeof(le));
        if (n < 0)
                return -errno;
        if (n != sizeof(le))
                return -EIO;

        return parse_crtime(le, usec);
}

int fd_setcrtime(int fd, usec_t usec) {
        le64_t le;

        assert(fd >= 0);

        if (usec <= 0)
                usec = now(CLOCK_REALTIME);

        le = htole64((uint64_t) usec);
        if (fsetxattr(fd, "user.crtime_usec", &le, sizeof(le), 0) < 0)
                return -errno;

        return 0;
}

int chattr_fd(int fd, unsigned value, unsigned mask) {
        unsigned old_attr, new_attr;
        struct stat st;

        assert(fd >= 0);

        if (fstat(fd, &st) < 0)
                return -errno;

        /* Explicitly check whether this is a regular file or
         * directory. If it is anything else (such as a device node or
         * fifo), then the ioctl will not hit the file systems but
         * possibly drivers, where the ioctl might have different
         * effects. Notably, DRM is using the same ioctl() number. */

        if (!S_ISDIR(st.st_mode) && !S_ISREG(st.st_mode))
                return -ENOTTY;

        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 1;
}

int chattr_path(const char *p, unsigned value, unsigned mask) {
        _cleanup_close_ int fd = -1;

        assert(p);

        if (mask == 0)
                return 0;

        fd = open(p, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
        if (fd < 0)
                return -errno;

        return chattr_fd(fd, value, mask);
}

int read_attr_fd(int fd, unsigned *ret) {
        struct stat st;

        assert(fd >= 0);

        if (fstat(fd, &st) < 0)
                return -errno;

        if (!S_ISDIR(st.st_mode) && !S_ISREG(st.st_mode))
                return -ENOTTY;

        if (ioctl(fd, FS_IOC_GETFLAGS, ret) < 0)
                return -errno;

        return 0;
}

int read_attr_path(const char *p, unsigned *ret) {
        _cleanup_close_ int fd = -1;

        assert(p);
        assert(ret);

        fd = open(p, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
        if (fd < 0)
                return -errno;

        return read_attr_fd(fd, ret);
}

static size_t nul_length(const uint8_t *p, size_t sz) {
        size_t n = 0;

        while (sz > 0) {
                if (*p != 0)
                        break;

                n++;
                p++;
                sz--;
        }

        return n;
}

ssize_t sparse_write(int fd, const void *p, size_t sz, size_t run_length) {
        const uint8_t *q, *w, *e;
        ssize_t l;

        q = w = p;
        e = q + sz;
        while (q < e) {
                size_t n;

                n = nul_length(q, e - q);

                /* If there are more than the specified run length of
                 * NUL bytes, or if this is the beginning or the end
                 * of the buffer, then seek instead of write */
                if ((n > run_length) ||
                    (n > 0 && q == p) ||
                    (n > 0 && q + n >= e)) {
                        if (q > w) {
                                l = write(fd, w, q - w);
                                if (l < 0)
                                        return -errno;
                                if (l != q -w)
                                        return -EIO;
                        }

                        if (lseek(fd, n, SEEK_CUR) == (off_t) -1)
                                return -errno;

                        q += n;
                        w = q;
                } else if (n > 0)
                        q += n;
                else
                        q ++;
        }

        if (q > w) {
                l = write(fd, w, q - w);
                if (l < 0)
                        return -errno;
                if (l != q - w)
                        return -EIO;
        }

        return q - (const uint8_t*) p;
}

void sigkill_wait(pid_t *pid) {
        if (!pid)
                return;
        if (*pid <= 1)
                return;

        if (kill(*pid, SIGKILL) > 0)
                (void) wait_for_terminate(*pid, NULL);
}

int syslog_parse_priority(const char **p, int *priority, bool with_facility) {
        int a = 0, b = 0, c = 0;
        int k;

        assert(p);
        assert(*p);
        assert(priority);

        if ((*p)[0] != '<')
                return 0;

        if (!strchr(*p, '>'))
                return 0;

        if ((*p)[2] == '>') {
                c = undecchar((*p)[1]);
                k = 3;
        } else if ((*p)[3] == '>') {
                b = undecchar((*p)[1]);
                c = undecchar((*p)[2]);
                k = 4;
        } else if ((*p)[4] == '>') {
                a = undecchar((*p)[1]);
                b = undecchar((*p)[2]);
                c = undecchar((*p)[3]);
                k = 5;
        } else
                return 0;

        if (a < 0 || b < 0 || c < 0 ||
            (!with_facility && (a || b || c > 7)))
                return 0;

        if (with_facility)
                *priority = a*100 + b*10 + c;
        else
                *priority = (*priority & LOG_FACMASK) | c;

        *p += k;
        return 1;
}

ssize_t string_table_lookup(const char * const *table, size_t len, const char *key) {
        size_t i;

        if (!key)
                return -1;

        for (i = 0; i < len; ++i)
                if (streq_ptr(table[i], key))
                        return (ssize_t) i;

        return -1;
}

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;

        /* renameat2() exists since Linux 3.15, btrfs added support for it later.
         * If it is not implemented, fallback to another method. */
        if (!IN_SET(errno, EINVAL, ENOSYS))
                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;
}

int parse_mode(const char *s, mode_t *ret) {
        char *x;
        long l;

        assert(s);
        assert(ret);

        errno = 0;
        l = strtol(s, &x, 8);
        if (errno != 0)
                return -errno;

        if (!x || x == s || *x)
                return -EINVAL;
        if (l < 0 || l  > 07777)
                return -ERANGE;

        *ret = (mode_t) l;
        return 0;
}

int mount_move_root(const char *path) {
        assert(path);

        if (chdir(path) < 0)
                return -errno;

        if (mount(path, "/", NULL, MS_MOVE, NULL) < 0)
                return -errno;

        if (chroot(".") < 0)
                return -errno;

        if (chdir("/") < 0)
                return -errno;

        return 0;
}

int reset_uid_gid(void) {

        if (setgroups(0, NULL) < 0)
                return -errno;

        if (setresgid(0, 0, 0) < 0)
                return -errno;

        if (setresuid(0, 0, 0) < 0)
                return -errno;

        return 0;
}

int getxattr_malloc(const char *path, const char *name, char **value, bool allow_symlink) {
        char *v;
        size_t l;
        ssize_t n;

        assert(path);
        assert(name);
        assert(value);

        for (l = 100; ; l = (size_t) n + 1) {
                v = new0(char, l);
                if (!v)
                        return -ENOMEM;

                if (allow_symlink)
                        n = lgetxattr(path, name, v, l);
                else
                        n = getxattr(path, name, v, l);

                if (n >= 0 && (size_t) n < l) {
                        *value = v;
                        return n;
                }

                free(v);

                if (n < 0 && errno != ERANGE)
                        return -errno;

                if (allow_symlink)
                        n = lgetxattr(path, name, NULL, 0);
                else
                        n = getxattr(path, name, NULL, 0);
                if (n < 0)
                        return -errno;
        }
}

int fgetxattr_malloc(int fd, const char *name, char **value) {
        char *v;
        size_t l;
        ssize_t n;

        assert(fd >= 0);
        assert(name);
        assert(value);

        for (l = 100; ; l = (size_t) n + 1) {
                v = new0(char, l);
                if (!v)
                        return -ENOMEM;

                n = fgetxattr(fd, name, v, l);

                if (n >= 0 && (size_t) n < l) {
                        *value = v;
                        return n;
                }

                free(v);

                if (n < 0 && errno != ERANGE)
                        return -errno;

                n = fgetxattr(fd, name, NULL, 0);
                if (n < 0)
                        return -errno;
        }
}

int send_one_fd(int transport_fd, int fd, int flags) {
        union {
                struct cmsghdr cmsghdr;
                uint8_t buf[CMSG_SPACE(sizeof(int))];
        } control = {};
        struct msghdr mh = {
                .msg_control = &control,
                .msg_controllen = sizeof(control),
        };
        struct cmsghdr *cmsg;

        assert(transport_fd >= 0);
        assert(fd >= 0);

        cmsg = CMSG_FIRSTHDR(&mh);
        cmsg->cmsg_level = SOL_SOCKET;
        cmsg->cmsg_type = SCM_RIGHTS;
        cmsg->cmsg_len = CMSG_LEN(sizeof(int));
        memcpy(CMSG_DATA(cmsg), &fd, sizeof(int));

        mh.msg_controllen = CMSG_SPACE(sizeof(int));
        if (sendmsg(transport_fd, &mh, MSG_NOSIGNAL | flags) < 0)
                return -errno;

        return 0;
}

int receive_one_fd(int transport_fd, int flags) {
        union {
                struct cmsghdr cmsghdr;
                uint8_t buf[CMSG_SPACE(sizeof(int))];
        } control = {};
        struct msghdr mh = {
                .msg_control = &control,
                .msg_controllen = sizeof(control),
        };
        struct cmsghdr *cmsg, *found = NULL;

        assert(transport_fd >= 0);

        /*
         * Receive a single FD via @transport_fd. We don't care for
         * the transport-type. We retrieve a single FD at most, so for
         * packet-based transports, the caller must ensure to send
         * only a single FD per packet.  This is best used in
         * combination with send_one_fd().
         */

        if (recvmsg(transport_fd, &mh, MSG_NOSIGNAL | MSG_CMSG_CLOEXEC | flags) < 0)
                return -errno;

        CMSG_FOREACH(cmsg, &mh) {
                if (cmsg->cmsg_level == SOL_SOCKET &&
                    cmsg->cmsg_type == SCM_RIGHTS &&
                    cmsg->cmsg_len == CMSG_LEN(sizeof(int))) {
                        assert(!found);
                        found = cmsg;
                        break;
                }
        }

        if (!found) {
                cmsg_close_all(&mh);
                return -EIO;
        }

        return *(int*) CMSG_DATA(found);
}

void nop_signal_handler(int sig) {
        /* nothing here */
}

int version(void) {
        puts(PACKAGE_STRING "\n"
             SYSTEMD_FEATURES);
        return 0;
}

bool fdname_is_valid(const char *s) {
        const char *p;

        /* Validates a name for $LISTEN_FDNAMES. We basically allow
         * everything ASCII that's not a control character. Also, as
         * special exception the ":" character is not allowed, as we
         * use that as field separator in $LISTEN_FDNAMES.
         *
         * Note that the empty string is explicitly allowed
         * here. However, we limit the length of the names to 255
         * characters. */

        if (!s)
                return false;

        for (p = s; *p; p++) {
                if (*p < ' ')
                        return false;
                if (*p >= 127)
                        return false;
                if (*p == ':')
                        return false;
        }

        return p - s < 256;
}

bool oom_score_adjust_is_valid(int oa) {
        return oa >= OOM_SCORE_ADJ_MIN && oa <= OOM_SCORE_ADJ_MAX;
}