src/core/execute.c

	execute.c revision f8b69d1dfc307562a353f6aa923b7c2b915aaddb
/*-*- 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 <assert.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <signal.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/prctl.h>
#include <linux/sched.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <grp.h>
#include <pwd.h>
#include <sys/mount.h>
#include <linux/fs.h>
#include <linux/oom.h>
#include <sys/poll.h>
#include <linux/seccomp-bpf.h>

#ifdef HAVE_PAM
#include <security/pam_appl.h>
#endif

#include "execute.h"
#include "strv.h"
#include "macro.h"
#include "capability.h"
#include "util.h"
#include "log.h"
#include "ioprio.h"
#include "securebits.h"
#include "cgroup.h"
#include "namespace.h"
#include "tcpwrap.h"
#include "exit-status.h"
#include "missing.h"
#include "utmp-wtmp.h"
#include "def.h"
#include "loopback-setup.h"
#include "path-util.h"
#include "syscall-list.h"
#include "sd-id128.h"
#include "sd-messages.h"

#define IDLE_TIMEOUT_USEC (5*USEC_PER_SEC)

/* This assumes there is a 'tty' group */
#define TTY_MODE 0620

static int shift_fds(int fds[], unsigned n_fds) {
        int start, restart_from;

        if (n_fds <= 0)
                return 0;

        /* Modifies the fds array! (sorts it) */

        assert(fds);

        start = 0;
        for (;;) {
                int i;

                restart_from = -1;

                for (i = start; i < (int) n_fds; i++) {
                        int nfd;

                        /* Already at right index? */
                        if (fds[i] == i+3)
                                continue;

                        if ((nfd = fcntl(fds[i], F_DUPFD, i+3)) < 0)
                                return -errno;

                        close_nointr_nofail(fds[i]);
                        fds[i] = nfd;

                        /* Hmm, the fd we wanted isn't free? Then
                         * let's remember that and try again from here*/
                        if (nfd != i+3 && restart_from < 0)
                                restart_from = i;
                }

                if (restart_from < 0)
                        break;

                start = restart_from;
        }

        return 0;
}

static int flags_fds(const int fds[], unsigned n_fds, bool nonblock) {
        unsigned i;
        int r;

        if (n_fds <= 0)
                return 0;

        assert(fds);

        /* Drops/Sets O_NONBLOCK and FD_CLOEXEC from the file flags */

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

                if ((r = fd_nonblock(fds[i], nonblock)) < 0)
                        return r;

                /* We unconditionally drop FD_CLOEXEC from the fds,
                 * since after all we want to pass these fds to our
                 * children */

                if ((r = fd_cloexec(fds[i], false)) < 0)
                        return r;
        }

        return 0;
}

static const char *tty_path(const ExecContext *context) {
        assert(context);

        if (context->tty_path)
                return context->tty_path;

        return "/dev/console";
}

void exec_context_tty_reset(const ExecContext *context) {
        assert(context);

        if (context->tty_vhangup)
                terminal_vhangup(tty_path(context));

        if (context->tty_reset)
                reset_terminal(tty_path(context));

        if (context->tty_vt_disallocate && context->tty_path)
                vt_disallocate(context->tty_path);
}

static int open_null_as(int flags, int nfd) {
        int fd, r;

        assert(nfd >= 0);

        if ((fd = open("/dev/null", flags|O_NOCTTY)) < 0)
                return -errno;

        if (fd != nfd) {
                r = dup2(fd, nfd) < 0 ? -errno : nfd;
                close_nointr_nofail(fd);
        } else
                r = nfd;

        return r;
}

static int connect_logger_as(const ExecContext *context, ExecOutput output, const char *ident, const char *unit_id, int nfd) {
        int fd, r;
        union sockaddr_union sa;

        assert(context);
        assert(output < _EXEC_OUTPUT_MAX);
        assert(ident);
        assert(nfd >= 0);

        fd = socket(AF_UNIX, SOCK_STREAM, 0);
        if (fd < 0)
                return -errno;

        zero(sa);
        sa.un.sun_family = AF_UNIX;
        strncpy(sa.un.sun_path, "/run/systemd/journal/stdout", sizeof(sa.un.sun_path));

        r = connect(fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(sa.un.sun_path));
        if (r < 0) {
                close_nointr_nofail(fd);
                return -errno;
        }

        if (shutdown(fd, SHUT_RD) < 0) {
                close_nointr_nofail(fd);
                return -errno;
        }

        dprintf(fd,
                "%s\n"
                "%s\n"
                "%i\n"
                "%i\n"
                "%i\n"
                "%i\n"
                "%i\n",
                context->syslog_identifier ? context->syslog_identifier : ident,
                unit_id,
                context->syslog_priority,
                !!context->syslog_level_prefix,
                output == EXEC_OUTPUT_SYSLOG || output == EXEC_OUTPUT_SYSLOG_AND_CONSOLE,
                output == EXEC_OUTPUT_KMSG || output == EXEC_OUTPUT_KMSG_AND_CONSOLE,
                output == EXEC_OUTPUT_SYSLOG_AND_CONSOLE || output == EXEC_OUTPUT_KMSG_AND_CONSOLE || output == EXEC_OUTPUT_JOURNAL_AND_CONSOLE);

        if (fd != nfd) {
                r = dup2(fd, nfd) < 0 ? -errno : nfd;
                close_nointr_nofail(fd);
        } else
                r = nfd;

        return r;
}
static int open_terminal_as(const char *path, mode_t mode, int nfd) {
        int fd, r;

        assert(path);
        assert(nfd >= 0);

        if ((fd = open_terminal(path, mode | O_NOCTTY)) < 0)
                return fd;

        if (fd != nfd) {
                r = dup2(fd, nfd) < 0 ? -errno : nfd;
                close_nointr_nofail(fd);
        } else
                r = nfd;

        return r;
}

static bool is_terminal_input(ExecInput i) {
        return
                i == EXEC_INPUT_TTY ||
                i == EXEC_INPUT_TTY_FORCE ||
                i == EXEC_INPUT_TTY_FAIL;
}

static int fixup_input(ExecInput std_input, int socket_fd, bool apply_tty_stdin) {

        if (is_terminal_input(std_input) && !apply_tty_stdin)
                return EXEC_INPUT_NULL;

        if (std_input == EXEC_INPUT_SOCKET && socket_fd < 0)
                return EXEC_INPUT_NULL;

        return std_input;
}

static int fixup_output(ExecOutput std_output, int socket_fd) {

        if (std_output == EXEC_OUTPUT_SOCKET && socket_fd < 0)
                return EXEC_OUTPUT_INHERIT;

        return std_output;
}

static int setup_input(const ExecContext *context, int socket_fd, bool apply_tty_stdin) {
        ExecInput i;

        assert(context);

        i = fixup_input(context->std_input, socket_fd, apply_tty_stdin);

        switch (i) {

        case EXEC_INPUT_NULL:
                return open_null_as(O_RDONLY, STDIN_FILENO);

        case EXEC_INPUT_TTY:
        case EXEC_INPUT_TTY_FORCE:
        case EXEC_INPUT_TTY_FAIL: {
                int fd, r;

                if ((fd = acquire_terminal(
                                     tty_path(context),
                                     i == EXEC_INPUT_TTY_FAIL,
                                     i == EXEC_INPUT_TTY_FORCE,
                                     false,
                                     (usec_t) -1)) < 0)
                        return fd;

                if (fd != STDIN_FILENO) {
                        r = dup2(fd, STDIN_FILENO) < 0 ? -errno : STDIN_FILENO;
                        close_nointr_nofail(fd);
                } else
                        r = STDIN_FILENO;

                return r;
        }

        case EXEC_INPUT_SOCKET:
                return dup2(socket_fd, STDIN_FILENO) < 0 ? -errno : STDIN_FILENO;

        default:
                assert_not_reached("Unknown input type");
        }
}

static int setup_output(const ExecContext *context, int socket_fd, const char *ident, const char *unit_id, bool apply_tty_stdin) {
        ExecOutput o;
        ExecInput i;

        assert(context);
        assert(ident);

        i = fixup_input(context->std_input, socket_fd, apply_tty_stdin);
        o = fixup_output(context->std_output, socket_fd);

        /* This expects the input is already set up */

        switch (o) {

        case EXEC_OUTPUT_INHERIT:

                /* If input got downgraded, inherit the original value */
                if (i == EXEC_INPUT_NULL && is_terminal_input(context->std_input))
                        return open_terminal_as(tty_path(context), O_WRONLY, STDOUT_FILENO);

                /* If the input is connected to anything that's not a /dev/null, inherit that... */
                if (i != EXEC_INPUT_NULL)
                        return dup2(STDIN_FILENO, STDOUT_FILENO) < 0 ? -errno : STDOUT_FILENO;

                /* If we are not started from PID 1 we just inherit STDOUT from our parent process. */
                if (getppid() != 1)
                        return STDOUT_FILENO;

                /* We need to open /dev/null here anew, to get the
                 * right access mode. So we fall through */

        case EXEC_OUTPUT_NULL:
                return open_null_as(O_WRONLY, STDOUT_FILENO);

        case EXEC_OUTPUT_TTY:
                if (is_terminal_input(i))
                        return dup2(STDIN_FILENO, STDOUT_FILENO) < 0 ? -errno : STDOUT_FILENO;

                /* We don't reset the terminal if this is just about output */
                return open_terminal_as(tty_path(context), O_WRONLY, STDOUT_FILENO);

        case EXEC_OUTPUT_SYSLOG:
        case EXEC_OUTPUT_SYSLOG_AND_CONSOLE:
        case EXEC_OUTPUT_KMSG:
        case EXEC_OUTPUT_KMSG_AND_CONSOLE:
        case EXEC_OUTPUT_JOURNAL:
        case EXEC_OUTPUT_JOURNAL_AND_CONSOLE:
                return connect_logger_as(context, o, ident, unit_id, STDOUT_FILENO);

        case EXEC_OUTPUT_SOCKET:
                assert(socket_fd >= 0);
                return dup2(socket_fd, STDOUT_FILENO) < 0 ? -errno : STDOUT_FILENO;

        default:
                assert_not_reached("Unknown output type");
        }
}

static int setup_error(const ExecContext *context, int socket_fd, const char *ident, const char *unit_id, bool apply_tty_stdin) {
        ExecOutput o, e;
        ExecInput i;

        assert(context);
        assert(ident);

        i = fixup_input(context->std_input, socket_fd, apply_tty_stdin);
        o = fixup_output(context->std_output, socket_fd);
        e = fixup_output(context->std_error, socket_fd);

        /* This expects the input and output are already set up */

        /* Don't change the stderr file descriptor if we inherit all
         * the way and are not on a tty */
        if (e == EXEC_OUTPUT_INHERIT &&
            o == EXEC_OUTPUT_INHERIT &&
            i == EXEC_INPUT_NULL &&
            !is_terminal_input(context->std_input) &&
            getppid () != 1)
                return STDERR_FILENO;

        /* Duplicate from stdout if possible */
        if (e == o || e == EXEC_OUTPUT_INHERIT)
                return dup2(STDOUT_FILENO, STDERR_FILENO) < 0 ? -errno : STDERR_FILENO;

        switch (e) {

        case EXEC_OUTPUT_NULL:
                return open_null_as(O_WRONLY, STDERR_FILENO);

        case EXEC_OUTPUT_TTY:
                if (is_terminal_input(i))
                        return dup2(STDIN_FILENO, STDERR_FILENO) < 0 ? -errno : STDERR_FILENO;

                /* We don't reset the terminal if this is just about output */
                return open_terminal_as(tty_path(context), O_WRONLY, STDERR_FILENO);

        case EXEC_OUTPUT_SYSLOG:
        case EXEC_OUTPUT_SYSLOG_AND_CONSOLE:
        case EXEC_OUTPUT_KMSG:
        case EXEC_OUTPUT_KMSG_AND_CONSOLE:
        case EXEC_OUTPUT_JOURNAL:
        case EXEC_OUTPUT_JOURNAL_AND_CONSOLE:
                return connect_logger_as(context, e, ident, unit_id, STDERR_FILENO);

        case EXEC_OUTPUT_SOCKET:
                assert(socket_fd >= 0);
                return dup2(socket_fd, STDERR_FILENO) < 0 ? -errno : STDERR_FILENO;

        default:
                assert_not_reached("Unknown error type");
        }
}

static int chown_terminal(int fd, uid_t uid) {
        struct stat st;

        assert(fd >= 0);

        /* This might fail. What matters are the results. */
        (void) fchown(fd, uid, -1);
        (void) fchmod(fd, TTY_MODE);

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

        if (st.st_uid != uid || (st.st_mode & 0777) != TTY_MODE)
                return -EPERM;

        return 0;
}

static int setup_confirm_stdio(int *_saved_stdin,
                               int *_saved_stdout) {
        int fd = -1, saved_stdin, saved_stdout = -1, r;

        assert(_saved_stdin);
        assert(_saved_stdout);

        saved_stdin = fcntl(STDIN_FILENO, F_DUPFD, 3);
        if (saved_stdin < 0)
                return -errno;

        saved_stdout = fcntl(STDOUT_FILENO, F_DUPFD, 3);
        if (saved_stdout < 0) {
                r = errno;
                goto fail;
        }

        fd = acquire_terminal(
                        "/dev/console",
                        false,
                        false,
                        false,
                        DEFAULT_CONFIRM_USEC);
        if (fd < 0) {
                r = fd;
                goto fail;
        }

        r = chown_terminal(fd, getuid());
        if (r < 0)
                goto fail;

        if (dup2(fd, STDIN_FILENO) < 0) {
                r = -errno;
                goto fail;
        }

        if (dup2(fd, STDOUT_FILENO) < 0) {
                r = -errno;
                goto fail;
        }

        if (fd >= 2)
                close_nointr_nofail(fd);

        *_saved_stdin = saved_stdin;
        *_saved_stdout = saved_stdout;

        return 0;

fail:
        if (saved_stdout >= 0)
                close_nointr_nofail(saved_stdout);

        if (saved_stdin >= 0)
                close_nointr_nofail(saved_stdin);

        if (fd >= 0)
                close_nointr_nofail(fd);

        return r;
}

static int write_confirm_message(const char *format, ...) {
        int fd;
        va_list ap;

        assert(format);

        fd = open_terminal("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC);
        if (fd < 0)
                return fd;

        va_start(ap, format);
        vdprintf(fd, format, ap);
        va_end(ap);

        close_nointr_nofail(fd);

        return 0;
}

static int restore_confirm_stdio(int *saved_stdin,
                                 int *saved_stdout) {

        int r = 0;

        assert(saved_stdin);
        assert(saved_stdout);

        release_terminal();

        if (*saved_stdin >= 0)
                if (dup2(*saved_stdin, STDIN_FILENO) < 0)
                        r = -errno;

        if (*saved_stdout >= 0)
                if (dup2(*saved_stdout, STDOUT_FILENO) < 0)
                        r = -errno;

        if (*saved_stdin >= 0)
                close_nointr_nofail(*saved_stdin);

        if (*saved_stdout >= 0)
                close_nointr_nofail(*saved_stdout);

        return r;
}

static int ask_for_confirmation(char *response, char **argv) {
        int saved_stdout = -1, saved_stdin = -1, r;
        char *line;

        r = setup_confirm_stdio(&saved_stdin, &saved_stdout);
        if (r < 0)
                return r;

        line = exec_command_line(argv);
        if (!line)
                return -ENOMEM;

        r = ask(response, "yns", "Execute %s? [Yes, No, Skip] ", line);
        free(line);

        restore_confirm_stdio(&saved_stdin, &saved_stdout);

        return r;
}

static int enforce_groups(const ExecContext *context, const char *username, gid_t gid) {
        bool keep_groups = false;
        int r;

        assert(context);

        /* Lookup and set GID and supplementary group list. Here too
         * we avoid NSS lookups for gid=0. */

        if (context->group || username) {

                if (context->group) {
                        const char *g = context->group;

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

                /* First step, initialize groups from /etc/groups */
                if (username && gid != 0) {
                        if (initgroups(username, gid) < 0)
                                return -errno;

                        keep_groups = true;
                }

                /* Second step, set our gids */
                if (setresgid(gid, gid, gid) < 0)
                        return -errno;
        }

        if (context->supplementary_groups) {
                int ngroups_max, k;
                gid_t *gids;
                char **i;

                /* Final step, initialize any manually set supplementary groups */
                assert_se((ngroups_max = (int) sysconf(_SC_NGROUPS_MAX)) > 0);

                if (!(gids = new(gid_t, ngroups_max)))
                        return -ENOMEM;

                if (keep_groups) {
                        if ((k = getgroups(ngroups_max, gids)) < 0) {
                                free(gids);
                                return -errno;
                        }
                } else
                        k = 0;

                STRV_FOREACH(i, context->supplementary_groups) {
                        const char *g;

                        if (k >= ngroups_max) {
                                free(gids);
                                return -E2BIG;
                        }

                        g = *i;
                        r = get_group_creds(&g, gids+k);
                        if (r < 0) {
                                free(gids);
                                return r;
                        }

                        k++;
                }

                if (setgroups(k, gids) < 0) {
                        free(gids);
                        return -errno;
                }

                free(gids);
        }

        return 0;
}

static int enforce_user(const ExecContext *context, uid_t uid) {
        int r;
        assert(context);

        /* Sets (but doesn't lookup) the uid and make sure we keep the
         * capabilities while doing so. */

        if (context->capabilities) {
                cap_t d;
                static const cap_value_t bits[] = {
                        CAP_SETUID,   /* Necessary so that we can run setresuid() below */
                        CAP_SETPCAP   /* Necessary so that we can set PR_SET_SECUREBITS later on */
                };

                /* First step: If we need to keep capabilities but
                 * drop privileges we need to make sure we keep our
                 * caps, whiel we drop privileges. */
                if (uid != 0) {
                        int sb = context->secure_bits|SECURE_KEEP_CAPS;

                        if (prctl(PR_GET_SECUREBITS) != sb)
                                if (prctl(PR_SET_SECUREBITS, sb) < 0)
                                        return -errno;
                }

                /* Second step: set the capabilities. This will reduce
                 * the capabilities to the minimum we need. */

                if (!(d = cap_dup(context->capabilities)))
                        return -errno;

                if (cap_set_flag(d, CAP_EFFECTIVE, ELEMENTSOF(bits), bits, CAP_SET) < 0 ||
                    cap_set_flag(d, CAP_PERMITTED, ELEMENTSOF(bits), bits, CAP_SET) < 0) {
                        r = -errno;
                        cap_free(d);
                        return r;
                }

                if (cap_set_proc(d) < 0) {
                        r = -errno;
                        cap_free(d);
                        return r;
                }

                cap_free(d);
        }

        /* Third step: actually set the uids */
        if (setresuid(uid, uid, uid) < 0)
                return -errno;

        /* At this point we should have all necessary capabilities but
           are otherwise a normal user. However, the caps might got
           corrupted due to the setresuid() so we need clean them up
           later. This is done outside of this call. */

        return 0;
}

#ifdef HAVE_PAM

static int null_conv(
                int num_msg,
                const struct pam_message **msg,
                struct pam_response **resp,
                void *appdata_ptr) {

        /* We don't support conversations */

        return PAM_CONV_ERR;
}

static int setup_pam(
                const char *name,
                const char *user,
                uid_t uid,
                const char *tty,
                char ***pam_env,
                int fds[], unsigned n_fds) {

        static const struct pam_conv conv = {
                .conv = null_conv,
                .appdata_ptr = NULL
        };

        pam_handle_t *handle = NULL;
        sigset_t ss, old_ss;
        int pam_code = PAM_SUCCESS;
        int err;
        char **e = NULL;
        bool close_session = false;
        pid_t pam_pid = 0, parent_pid;

        assert(name);
        assert(user);
        assert(pam_env);

        /* We set up PAM in the parent process, then fork. The child
         * will then stay around until killed via PR_GET_PDEATHSIG or
         * systemd via the cgroup logic. It will then remove the PAM
         * session again. The parent process will exec() the actual
         * daemon. We do things this way to ensure that the main PID
         * of the daemon is the one we initially fork()ed. */

        if ((pam_code = pam_start(name, user, &conv, &handle)) != PAM_SUCCESS) {
                handle = NULL;
                goto fail;
        }

        if (tty)
                if ((pam_code = pam_set_item(handle, PAM_TTY, tty)) != PAM_SUCCESS)
                        goto fail;

        if ((pam_code = pam_acct_mgmt(handle, PAM_SILENT)) != PAM_SUCCESS)
                goto fail;

        if ((pam_code = pam_open_session(handle, PAM_SILENT)) != PAM_SUCCESS)
                goto fail;

        close_session = true;

        if ((!(e = pam_getenvlist(handle)))) {
                pam_code = PAM_BUF_ERR;
                goto fail;
        }

        /* Block SIGTERM, so that we know that it won't get lost in
         * the child */
        if (sigemptyset(&ss) < 0 ||
            sigaddset(&ss, SIGTERM) < 0 ||
            sigprocmask(SIG_BLOCK, &ss, &old_ss) < 0)
                goto fail;

        parent_pid = getpid();

        if ((pam_pid = fork()) < 0)
                goto fail;

        if (pam_pid == 0) {
                int sig;
                int r = EXIT_PAM;

                /* The child's job is to reset the PAM session on
                 * termination */

                /* This string must fit in 10 chars (i.e. the length
                 * of "/sbin/init"), to look pretty in /bin/ps */
                rename_process("(sd-pam)");

                /* Make sure we don't keep open the passed fds in this
                child. We assume that otherwise only those fds are
                open here that have been opened by PAM. */
                close_many(fds, n_fds);

                /* Drop privileges - we don't need any to pam_close_session
                 * and this will make PR_SET_PDEATHSIG work in most cases.
                 * If this fails, ignore the error - but expect sd-pam threads
                 * to fail to exit normally */
                if (setresuid(uid, uid, uid) < 0)
                        log_error("Error: Failed to setresuid() in sd-pam: %s", strerror(-r));

                /* Wait until our parent died. This will only work if
                 * the above setresuid() succeeds, otherwise the kernel
                 * will not allow unprivileged parents kill their privileged
                 * children this way. We rely on the control groups kill logic
                 * to do the rest for us. */
                if (prctl(PR_SET_PDEATHSIG, SIGTERM) < 0)
                        goto child_finish;

                /* Check if our parent process might already have
                 * died? */
                if (getppid() == parent_pid) {
                        for (;;) {
                                if (sigwait(&ss, &sig) < 0) {
                                        if (errno == EINTR)
                                                continue;

                                        goto child_finish;
                                }

                                assert(sig == SIGTERM);
                                break;
                        }
                }

                /* If our parent died we'll end the session */
                if (getppid() != parent_pid)
                        if ((pam_code = pam_close_session(handle, PAM_DATA_SILENT)) != PAM_SUCCESS)
                                goto child_finish;

                r = 0;

        child_finish:
                pam_end(handle, pam_code | PAM_DATA_SILENT);
                _exit(r);
        }

        /* If the child was forked off successfully it will do all the
         * cleanups, so forget about the handle here. */
        handle = NULL;

        /* Unblock SIGTERM again in the parent */
        if (sigprocmask(SIG_SETMASK, &old_ss, NULL) < 0)
                goto fail;

        /* We close the log explicitly here, since the PAM modules
         * might have opened it, but we don't want this fd around. */
        closelog();

        *pam_env = e;
        e = NULL;

        return 0;

fail:
        if (pam_code != PAM_SUCCESS)
                err = -EPERM;  /* PAM errors do not map to errno */
        else
                err = -errno;

        if (handle) {
                if (close_session)
                        pam_code = pam_close_session(handle, PAM_DATA_SILENT);

                pam_end(handle, pam_code | PAM_DATA_SILENT);
        }

        strv_free(e);

        closelog();

        if (pam_pid > 1) {
                kill(pam_pid, SIGTERM);
                kill(pam_pid, SIGCONT);
        }

        return err;
}
#endif

static void rename_process_from_path(const char *path) {
        char process_name[11];
        const char *p;
        size_t l;

        /* This resulting string must fit in 10 chars (i.e. the length
         * of "/sbin/init") to look pretty in /bin/ps */

        p = path_get_file_name(path);
        if (isempty(p)) {
                rename_process("(...)");
                return;
        }

        l = strlen(p);
        if (l > 8) {
                /* The end of the process name is usually more
                 * interesting, since the first bit might just be
                 * "systemd-" */
                p = p + l - 8;
                l = 8;
        }

        process_name[0] = '(';
        memcpy(process_name+1, p, l);
        process_name[1+l] = ')';
        process_name[1+l+1] = 0;

        rename_process(process_name);
}

static int apply_seccomp(uint32_t *syscall_filter) {
        static const struct sock_filter header[] = {
                VALIDATE_ARCHITECTURE,
                EXAMINE_SYSCALL
        };
        static const struct sock_filter footer[] = {
                _KILL_PROCESS
        };

        int i;
        unsigned n;
        struct sock_filter *f;
        struct sock_fprog prog;

        assert(syscall_filter);

        /* First: count the syscalls to check for */
        for (i = 0, n = 0; i < syscall_max(); i++)
                if (syscall_filter[i >> 4] & (1 << (i & 31)))
                        n++;

        /* Second: build the filter program from a header the syscall
         * matches and the footer */
        f = alloca(sizeof(struct sock_filter) * (ELEMENTSOF(header) + 2*n + ELEMENTSOF(footer)));
        memcpy(f, header, sizeof(header));

        for (i = 0, n = 0; i < syscall_max(); i++)
                if (syscall_filter[i >> 4] & (1 << (i & 31))) {
                        struct sock_filter item[] = {
                                BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, i, 0, 1),
                                BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW)
                        };

                        assert_cc(ELEMENTSOF(item) == 2);

                        f[ELEMENTSOF(header) + 2*n]  = item[0];
                        f[ELEMENTSOF(header) + 2*n+1] = item[1];

                        n++;
                }

        memcpy(f + (ELEMENTSOF(header) + 2*n), footer, sizeof(footer));

        /* Third: install the filter */
        zero(prog);
        prog.len = ELEMENTSOF(header) + ELEMENTSOF(footer) + 2*n;
        prog.filter = f;
        if (prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog) < 0)
                return -errno;

        return 0;
}

int exec_spawn(ExecCommand *command,
               char **argv,
               const ExecContext *context,
               int fds[], unsigned n_fds,
               char **environment,
               bool apply_permissions,
               bool apply_chroot,
               bool apply_tty_stdin,
               bool confirm_spawn,
               CGroupBonding *cgroup_bondings,
               CGroupAttribute *cgroup_attributes,
               const char *cgroup_suffix,
               const char *unit_id,
               int idle_pipe[2],
               pid_t *ret) {

        pid_t pid;
        int r;
        char *line;
        int socket_fd;
        char _cleanup_strv_free_ **files_env = NULL;

        assert(command);
        assert(context);
        assert(ret);
        assert(fds || n_fds <= 0);

        if (context->std_input == EXEC_INPUT_SOCKET ||
            context->std_output == EXEC_OUTPUT_SOCKET ||
            context->std_error == EXEC_OUTPUT_SOCKET) {

                if (n_fds != 1)
                        return -EINVAL;

                socket_fd = fds[0];

                fds = NULL;
                n_fds = 0;
        } else
                socket_fd = -1;

        r = exec_context_load_environment(context, &files_env);
        if (r < 0) {
                log_struct(LOG_ERR,
                           "UNIT=%s", unit_id,
                           "MESSAGE=Failed to load environment files: %s", strerror(-r),
                           "ERRNO=%d", -r,
                           NULL);
                return r;
        }

        if (!argv)
                argv = command->argv;

        line = exec_command_line(argv);
        if (!line)
                return log_oom();

        log_struct(LOG_DEBUG,
                   "UNIT=%s", unit_id,
                   "MESSAGE=About to execute %s", line,
                   NULL);
        free(line);

        r = cgroup_bonding_realize_list(cgroup_bondings);
        if (r < 0)
                return r;

        cgroup_attribute_apply_list(cgroup_attributes, cgroup_bondings);

        pid = fork();
        if (pid < 0)
                return -errno;

        if (pid == 0) {
                int i, err;
                sigset_t ss;
                const char *username = NULL, *home = NULL;
                uid_t uid = (uid_t) -1;
                gid_t gid = (gid_t) -1;
                char _cleanup_strv_free_ **our_env = NULL, **pam_env = NULL,
                        **final_env = NULL, **final_argv = NULL;
                unsigned n_env = 0;
                bool set_access = false;

                /* child */

                rename_process_from_path(command->path);

                /* We reset exactly these signals, since they are the
                 * only ones we set to SIG_IGN in the main daemon. All
                 * others we leave untouched because we set them to
                 * SIG_DFL or a valid handler initially, both of which
                 * will be demoted to SIG_DFL. */
                default_signals(SIGNALS_CRASH_HANDLER,
                                SIGNALS_IGNORE, -1);

                if (context->ignore_sigpipe)
                        ignore_signals(SIGPIPE, -1);

                assert_se(sigemptyset(&ss) == 0);
                if (sigprocmask(SIG_SETMASK, &ss, NULL) < 0) {
                        err = -errno;
                        r = EXIT_SIGNAL_MASK;
                        goto fail_child;
                }

                if (idle_pipe) {
                        if (idle_pipe[1] >= 0)
                                close_nointr_nofail(idle_pipe[1]);
                        if (idle_pipe[0] >= 0) {
                                fd_wait_for_event(idle_pipe[0], POLLHUP, IDLE_TIMEOUT_USEC);
                                close_nointr_nofail(idle_pipe[0]);
                        }
                }

                /* Close sockets very early to make sure we don't
                 * block init reexecution because it cannot bind its
                 * sockets */
                log_forget_fds();
                err = close_all_fds(socket_fd >= 0 ? &socket_fd : fds,
                                           socket_fd >= 0 ? 1 : n_fds);
                if (err < 0) {
                        r = EXIT_FDS;
                        goto fail_child;
                }

                if (!context->same_pgrp)
                        if (setsid() < 0) {
                                err = -errno;
                                r = EXIT_SETSID;
                                goto fail_child;
                        }

                if (context->tcpwrap_name) {
                        if (socket_fd >= 0)
                                if (!socket_tcpwrap(socket_fd, context->tcpwrap_name)) {
                                        err = -EACCES;
                                        r = EXIT_TCPWRAP;
                                        goto fail_child;
                                }

                        for (i = 0; i < (int) n_fds; i++) {
                                if (!socket_tcpwrap(fds[i], context->tcpwrap_name)) {
                                        err = -EACCES;
                                        r = EXIT_TCPWRAP;
                                        goto fail_child;
                                }
                        }
                }

                exec_context_tty_reset(context);

                if (confirm_spawn) {
                        char response;

                        err = ask_for_confirmation(&response, argv);
                        if (err == -ETIMEDOUT)
                                write_confirm_message("Confirmation question timed out, assuming positive response.\n");
                        else if (err < 0)
                                write_confirm_message("Couldn't ask confirmation question, assuming positive response: %s\n", strerror(-err));
                        else if (response == 's') {
                                write_confirm_message("Skipping execution.\n");
                                err = -ECANCELED;
                                r = EXIT_CONFIRM;
                                goto fail_child;
                        } else if (response == 'n') {
                                write_confirm_message("Failing execution.\n");
                                err = r = 0;
                                goto fail_child;
                        }
                }

                /* If a socket is connected to STDIN/STDOUT/STDERR, we
                 * must sure to drop O_NONBLOCK */
                if (socket_fd >= 0)
                        fd_nonblock(socket_fd, false);

                err = setup_input(context, socket_fd, apply_tty_stdin);
                if (err < 0) {
                        r = EXIT_STDIN;
                        goto fail_child;
                }

                err = setup_output(context, socket_fd, path_get_file_name(command->path), unit_id, apply_tty_stdin);
                if (err < 0) {
                        r = EXIT_STDOUT;
                        goto fail_child;
                }

                err = setup_error(context, socket_fd, path_get_file_name(command->path), unit_id, apply_tty_stdin);
                if (err < 0) {
                        r = EXIT_STDERR;
                        goto fail_child;
                }

                if (cgroup_bondings) {
                        err = cgroup_bonding_install_list(cgroup_bondings, 0, cgroup_suffix);
                        if (err < 0) {
                                r = EXIT_CGROUP;
                                goto fail_child;
                        }
                }

                if (context->oom_score_adjust_set) {
                        char t[16];

                        snprintf(t, sizeof(t), "%i", context->oom_score_adjust);
                        char_array_0(t);

                        if (write_one_line_file("/proc/self/oom_score_adj", t) < 0) {
                                err = -errno;
                                r = EXIT_OOM_ADJUST;
                                goto fail_child;
                        }
                }

                if (context->nice_set)
                        if (setpriority(PRIO_PROCESS, 0, context->nice) < 0) {
                                err = -errno;
                                r = EXIT_NICE;
                                goto fail_child;
                        }

                if (context->cpu_sched_set) {
                        struct sched_param param;

                        zero(param);
                        param.sched_priority = context->cpu_sched_priority;

                        if (sched_setscheduler(0, context->cpu_sched_policy |
                                               (context->cpu_sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0), &param) < 0) {
                                err = -errno;
                                r = EXIT_SETSCHEDULER;
                                goto fail_child;
                        }
                }

                if (context->cpuset)
                        if (sched_setaffinity(0, CPU_ALLOC_SIZE(context->cpuset_ncpus), context->cpuset) < 0) {
                                err = -errno;
                                r = EXIT_CPUAFFINITY;
                                goto fail_child;
                        }

                if (context->ioprio_set)
                        if (ioprio_set(IOPRIO_WHO_PROCESS, 0, context->ioprio) < 0) {
                                err = -errno;
                                r = EXIT_IOPRIO;
                                goto fail_child;
                        }

                if (context->timer_slack_nsec != (nsec_t) -1)
                        if (prctl(PR_SET_TIMERSLACK, context->timer_slack_nsec) < 0) {
                                err = -errno;
                                r = EXIT_TIMERSLACK;
                                goto fail_child;
                        }

                if (context->utmp_id)
                        utmp_put_init_process(context->utmp_id, getpid(), getsid(0), context->tty_path);

                if (context->user) {
                        username = context->user;
                        err = get_user_creds(&username, &uid, &gid, &home, NULL);
                        if (err < 0) {
                                r = EXIT_USER;
                                goto fail_child;
                        }

                        if (is_terminal_input(context->std_input)) {
                                err = chown_terminal(STDIN_FILENO, uid);
                                if (err < 0) {
                                        r = EXIT_STDIN;
                                        goto fail_child;
                                }
                        }

                        if (cgroup_bondings && context->control_group_modify) {
                                err = cgroup_bonding_set_group_access_list(cgroup_bondings, 0755, uid, gid);
                                if (err >= 0)
                                        err = cgroup_bonding_set_task_access_list(cgroup_bondings, 0644, uid, gid, context->control_group_persistent);
                                if (err < 0) {
                                        r = EXIT_CGROUP;
                                        goto fail_child;
                                }

                                set_access = true;
                        }
                }

                if (cgroup_bondings && !set_access && context->control_group_persistent >= 0)  {
                        err = cgroup_bonding_set_task_access_list(cgroup_bondings, (mode_t) -1, (uid_t) -1, (uid_t) -1, context->control_group_persistent);
                        if (err < 0) {
                                r = EXIT_CGROUP;
                                goto fail_child;
                        }
                }

                if (apply_permissions) {
                        err = enforce_groups(context, username, gid);
                        if (err < 0) {
                                r = EXIT_GROUP;
                                goto fail_child;
                        }
                }

                umask(context->umask);

#ifdef HAVE_PAM
                if (apply_permissions && context->pam_name && username) {
                        err = setup_pam(context->pam_name, username, uid, context->tty_path, &pam_env, fds, n_fds);
                        if (err < 0) {
                                r = EXIT_PAM;
                                goto fail_child;
                        }
                }
#endif
                if (context->private_network) {
                        if (unshare(CLONE_NEWNET) < 0) {
                                err = -errno;
                                r = EXIT_NETWORK;
                                goto fail_child;
                        }

                        loopback_setup();
                }

                if (strv_length(context->read_write_dirs) > 0 ||
                    strv_length(context->read_only_dirs) > 0 ||
                    strv_length(context->inaccessible_dirs) > 0 ||
                    context->mount_flags != 0 ||
                    context->private_tmp) {
                        err = setup_namespace(context->read_write_dirs,
                                              context->read_only_dirs,
                                              context->inaccessible_dirs,
                                              context->private_tmp,
                                              context->mount_flags);
                        if (err < 0) {
                                r = EXIT_NAMESPACE;
                                goto fail_child;
                        }
                }

                if (apply_chroot) {
                        if (context->root_directory)
                                if (chroot(context->root_directory) < 0) {
                                        err = -errno;
                                        r = EXIT_CHROOT;
                                        goto fail_child;
                                }

                        if (chdir(context->working_directory ? context->working_directory : "/") < 0) {
                                err = -errno;
                                r = EXIT_CHDIR;
                                goto fail_child;
                        }
                } else {
                        char _cleanup_free_ *d = NULL;

                        if (asprintf(&d, "%s/%s",
                                     context->root_directory ? context->root_directory : "",
                                     context->working_directory ? context->working_directory : "") < 0) {
                                err = -ENOMEM;
                                r = EXIT_MEMORY;
                                goto fail_child;
                        }

                        if (chdir(d) < 0) {
                                err = -errno;
                                r = EXIT_CHDIR;
                                goto fail_child;
                        }
                }

                /* We repeat the fd closing here, to make sure that
                 * nothing is leaked from the PAM modules */
                err = close_all_fds(fds, n_fds);
                if (err >= 0)
                        err = shift_fds(fds, n_fds);
                if (err >= 0)
                        err = flags_fds(fds, n_fds, context->non_blocking);
                if (err < 0) {
                        r = EXIT_FDS;
                        goto fail_child;
                }

                if (apply_permissions) {

                        for (i = 0; i < RLIMIT_NLIMITS; i++) {
                                if (!context->rlimit[i])
                                        continue;

                                if (setrlimit_closest(i, context->rlimit[i]) < 0) {
                                        err = -errno;
                                        r = EXIT_LIMITS;
                                        goto fail_child;
                                }
                        }

                        if (context->capability_bounding_set_drop) {
                                err = capability_bounding_set_drop(context->capability_bounding_set_drop, false);
                                if (err < 0) {
                                        r = EXIT_CAPABILITIES;
                                        goto fail_child;
                                }
                        }

                        if (context->user) {
                                err = enforce_user(context, uid);
                                if (err < 0) {
                                        r = EXIT_USER;
                                        goto fail_child;
                                }
                        }

                        /* PR_GET_SECUREBITS is not privileged, while
                         * PR_SET_SECUREBITS is. So to suppress
                         * potential EPERMs we'll try not to call
                         * PR_SET_SECUREBITS unless necessary. */
                        if (prctl(PR_GET_SECUREBITS) != context->secure_bits)
                                if (prctl(PR_SET_SECUREBITS, context->secure_bits) < 0) {
                                        err = -errno;
                                        r = EXIT_SECUREBITS;
                                        goto fail_child;
                                }

                        if (context->capabilities)
                                if (cap_set_proc(context->capabilities) < 0) {
                                        err = -errno;
                                        r = EXIT_CAPABILITIES;
                                        goto fail_child;
                                }

                        if (context->no_new_privileges)
                                if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) < 0) {
                                        err = -errno;
                                        r = EXIT_NO_NEW_PRIVILEGES;
                                        goto fail_child;
                                }

                        if (context->syscall_filter) {
                                err = apply_seccomp(context->syscall_filter);
                                if (err < 0) {
                                        r = EXIT_SECCOMP;
                                        goto fail_child;
                                }
                        }
                }

                if (!(our_env = new0(char*, 7))) {
                        err = -ENOMEM;
                        r = EXIT_MEMORY;
                        goto fail_child;
                }

                if (n_fds > 0)
                        if (asprintf(our_env + n_env++, "LISTEN_PID=%lu", (unsigned long) getpid()) < 0 ||
                            asprintf(our_env + n_env++, "LISTEN_FDS=%u", n_fds) < 0) {
                                err = -ENOMEM;
                                r = EXIT_MEMORY;
                                goto fail_child;
                        }

                if (home)
                        if (asprintf(our_env + n_env++, "HOME=%s", home) < 0) {
                                err = -ENOMEM;
                                r = EXIT_MEMORY;
                                goto fail_child;
                        }

                if (username)
                        if (asprintf(our_env + n_env++, "LOGNAME=%s", username) < 0 ||
                            asprintf(our_env + n_env++, "USER=%s", username) < 0) {
                                err = -ENOMEM;
                                r = EXIT_MEMORY;
                                goto fail_child;
                        }

                if (is_terminal_input(context->std_input) ||
                    context->std_output == EXEC_OUTPUT_TTY ||
                    context->std_error == EXEC_OUTPUT_TTY)
                        if (!(our_env[n_env++] = strdup(default_term_for_tty(tty_path(context))))) {
                                err = -ENOMEM;
                                r = EXIT_MEMORY;
                                goto fail_child;
                        }

                assert(n_env <= 7);

                if (!(final_env = strv_env_merge(
                                      5,
                                      environment,
                                      our_env,
                                      context->environment,
                                      files_env,
                                      pam_env,
                                      NULL))) {
                        err = -ENOMEM;
                        r = EXIT_MEMORY;
                        goto fail_child;
                }

                if (!(final_argv = replace_env_argv(argv, final_env))) {
                        err = -ENOMEM;
                        r = EXIT_MEMORY;
                        goto fail_child;
                }

                final_env = strv_env_clean(final_env);

                execve(command->path, final_argv, final_env);
                err = -errno;
                r = EXIT_EXEC;

        fail_child:
                if (r != 0) {
                        log_open();
                        log_struct(LOG_ERR, MESSAGE_ID(SD_MESSAGE_SPAWN_FAILED),
                                   "EXECUTABLE=%s", command->path,
                                   "MESSAGE=Failed at step %s spawning %s: %s",
                                          exit_status_to_string(r, EXIT_STATUS_SYSTEMD),
                                          command->path, strerror(-err),
                                   "ERRNO=%d", -err,
                                   NULL);
                        log_close();
                }

                _exit(r);
        }

        log_struct(LOG_DEBUG,
                   "UNIT=%s", unit_id,
                   "MESSAGE=Forked %s as %lu",
                          command->path, (unsigned long) pid,
                   NULL);

        /* We add the new process to the cgroup both in the child (so
         * that we can be sure that no user code is ever executed
         * outside of the cgroup) and in the parent (so that we can be
         * sure that when we kill the cgroup the process will be
         * killed too). */
        if (cgroup_bondings)
                cgroup_bonding_install_list(cgroup_bondings, pid, cgroup_suffix);

        exec_status_start(&command->exec_status, pid);

        *ret = pid;
        return 0;
}

void exec_context_init(ExecContext *c) {
        assert(c);

        c->umask = 0022;
        c->ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 0);
        c->cpu_sched_policy = SCHED_OTHER;
        c->syslog_priority = LOG_DAEMON|LOG_INFO;
        c->syslog_level_prefix = true;
        c->control_group_persistent = -1;
        c->ignore_sigpipe = true;
        c->timer_slack_nsec = (nsec_t) -1;
}

void exec_context_done(ExecContext *c) {
        unsigned l;

        assert(c);

        strv_free(c->environment);
        c->environment = NULL;

        strv_free(c->environment_files);
        c->environment_files = NULL;

        for (l = 0; l < ELEMENTSOF(c->rlimit); l++) {
                free(c->rlimit[l]);
                c->rlimit[l] = NULL;
        }

        free(c->working_directory);
        c->working_directory = NULL;
        free(c->root_directory);
        c->root_directory = NULL;

        free(c->tty_path);
        c->tty_path = NULL;

        free(c->tcpwrap_name);
        c->tcpwrap_name = NULL;

        free(c->syslog_identifier);
        c->syslog_identifier = NULL;

        free(c->user);
        c->user = NULL;

        free(c->group);
        c->group = NULL;

        strv_free(c->supplementary_groups);
        c->supplementary_groups = NULL;

        free(c->pam_name);
        c->pam_name = NULL;

        if (c->capabilities) {
                cap_free(c->capabilities);
                c->capabilities = NULL;
        }

        strv_free(c->read_only_dirs);
        c->read_only_dirs = NULL;

        strv_free(c->read_write_dirs);
        c->read_write_dirs = NULL;

        strv_free(c->inaccessible_dirs);
        c->inaccessible_dirs = NULL;

        if (c->cpuset)
                CPU_FREE(c->cpuset);

        free(c->utmp_id);
        c->utmp_id = NULL;

        free(c->syscall_filter);
        c->syscall_filter = NULL;
}

void exec_command_done(ExecCommand *c) {
        assert(c);

        free(c->path);
        c->path = NULL;

        strv_free(c->argv);
        c->argv = NULL;
}

void exec_command_done_array(ExecCommand *c, unsigned n) {
        unsigned i;

        for (i = 0; i < n; i++)
                exec_command_done(c+i);
}

void exec_command_free_list(ExecCommand *c) {
        ExecCommand *i;

        while ((i = c)) {
                LIST_REMOVE(ExecCommand, command, c, i);
                exec_command_done(i);
                free(i);
        }
}

void exec_command_free_array(ExecCommand **c, unsigned n) {
        unsigned i;

        for (i = 0; i < n; i++) {
                exec_command_free_list(c[i]);
                c[i] = NULL;
        }
}

int exec_context_load_environment(const ExecContext *c, char ***l) {
        char **i, **r = NULL;

        assert(c);
        assert(l);

        STRV_FOREACH(i, c->environment_files) {
                char *fn;
                int k;
                bool ignore = false;
                char **p;

                fn = *i;

                if (fn[0] == '-') {
                        ignore = true;
                        fn ++;
                }

                if (!path_is_absolute(fn)) {

                        if (ignore)
                                continue;

                        strv_free(r);
                        return -EINVAL;
                }

                if ((k = load_env_file(fn, &p)) < 0) {

                        if (ignore)
                                continue;

                        strv_free(r);
                        return k;
                }

                if (r == NULL)
                        r = p;
                else {
                        char **m;

                        m = strv_env_merge(2, r, p);
                        strv_free(r);
                        strv_free(p);

                        if (!m)
                                return -ENOMEM;

                        r = m;
                }
        }

        *l = r;

        return 0;
}

static void strv_fprintf(FILE *f, char **l) {
        char **g;

        assert(f);

        STRV_FOREACH(g, l)
                fprintf(f, " %s", *g);
}

void exec_context_dump(ExecContext *c, FILE* f, const char *prefix) {
        char ** e;
        unsigned i;

        assert(c);
        assert(f);

        if (!prefix)
                prefix = "";

        fprintf(f,
                "%sUMask: %04o\n"
                "%sWorkingDirectory: %s\n"
                "%sRootDirectory: %s\n"
                "%sNonBlocking: %s\n"
                "%sPrivateTmp: %s\n"
                "%sControlGroupModify: %s\n"
                "%sControlGroupPersistent: %s\n"
                "%sPrivateNetwork: %s\n"
                "%sIgnoreSIGPIPE: %s\n",
                prefix, c->umask,
                prefix, c->working_directory ? c->working_directory : "/",
                prefix, c->root_directory ? c->root_directory : "/",
                prefix, yes_no(c->non_blocking),
                prefix, yes_no(c->private_tmp),
                prefix, yes_no(c->control_group_modify),
                prefix, yes_no(c->control_group_persistent),
                prefix, yes_no(c->private_network),
                prefix, yes_no(c->ignore_sigpipe));

        STRV_FOREACH(e, c->environment)
                fprintf(f, "%sEnvironment: %s\n", prefix, *e);

        STRV_FOREACH(e, c->environment_files)
                fprintf(f, "%sEnvironmentFile: %s\n", prefix, *e);

        if (c->tcpwrap_name)
                fprintf(f,
                        "%sTCPWrapName: %s\n",
                        prefix, c->tcpwrap_name);

        if (c->nice_set)
                fprintf(f,
                        "%sNice: %i\n",
                        prefix, c->nice);

        if (c->oom_score_adjust_set)
                fprintf(f,
                        "%sOOMScoreAdjust: %i\n",
                        prefix, c->oom_score_adjust);

        for (i = 0; i < RLIM_NLIMITS; i++)
                if (c->rlimit[i])
                        fprintf(f, "%s%s: %llu\n", prefix, rlimit_to_string(i), (unsigned long long) c->rlimit[i]->rlim_max);

        if (c->ioprio_set) {
                char *class_str;
                int r;

                r = ioprio_class_to_string_alloc(IOPRIO_PRIO_CLASS(c->ioprio), &class_str);
                if (r < 0)
                        class_str = NULL;
                fprintf(f,
                        "%sIOSchedulingClass: %s\n"
                        "%sIOPriority: %i\n",
                        prefix, strna(class_str),
                        prefix, (int) IOPRIO_PRIO_DATA(c->ioprio));
                free(class_str);
        }

        if (c->cpu_sched_set) {
                char *policy_str;
                int r;

                r = sched_policy_to_string_alloc(c->cpu_sched_policy, &policy_str);
                if (r < 0)
                        policy_str = NULL;
                fprintf(f,
                        "%sCPUSchedulingPolicy: %s\n"
                        "%sCPUSchedulingPriority: %i\n"
                        "%sCPUSchedulingResetOnFork: %s\n",
                        prefix, strna(policy_str),
                        prefix, c->cpu_sched_priority,
                        prefix, yes_no(c->cpu_sched_reset_on_fork));
                free(policy_str);
    }

        if (c->cpuset) {
                fprintf(f, "%sCPUAffinity:", prefix);
                for (i = 0; i < c->cpuset_ncpus; i++)
                        if (CPU_ISSET_S(i, CPU_ALLOC_SIZE(c->cpuset_ncpus), c->cpuset))
                                fprintf(f, " %i", i);
                fputs("\n", f);
        }

        if (c->timer_slack_nsec != (nsec_t) -1)
                fprintf(f, "%sTimerSlackNSec: %lu\n", prefix, (unsigned long)c->timer_slack_nsec);

        fprintf(f,
                "%sStandardInput: %s\n"
                "%sStandardOutput: %s\n"
                "%sStandardError: %s\n",
                prefix, exec_input_to_string(c->std_input),
                prefix, exec_output_to_string(c->std_output),
                prefix, exec_output_to_string(c->std_error));

        if (c->tty_path)
                fprintf(f,
                        "%sTTYPath: %s\n"
                        "%sTTYReset: %s\n"
                        "%sTTYVHangup: %s\n"
                        "%sTTYVTDisallocate: %s\n",
                        prefix, c->tty_path,
                        prefix, yes_no(c->tty_reset),
                        prefix, yes_no(c->tty_vhangup),
                        prefix, yes_no(c->tty_vt_disallocate));

        if (c->std_output == EXEC_OUTPUT_SYSLOG || c->std_output == EXEC_OUTPUT_KMSG || c->std_output == EXEC_OUTPUT_JOURNAL ||
            c->std_output == EXEC_OUTPUT_SYSLOG_AND_CONSOLE || c->std_output == EXEC_OUTPUT_KMSG_AND_CONSOLE || c->std_output == EXEC_OUTPUT_JOURNAL_AND_CONSOLE ||
            c->std_error == EXEC_OUTPUT_SYSLOG || c->std_error == EXEC_OUTPUT_KMSG || c->std_error == EXEC_OUTPUT_JOURNAL ||
            c->std_error == EXEC_OUTPUT_SYSLOG_AND_CONSOLE || c->std_error == EXEC_OUTPUT_KMSG_AND_CONSOLE || c->std_error == EXEC_OUTPUT_JOURNAL_AND_CONSOLE) {
                char *fac_str, *lvl_str;
                int r;

                r = log_facility_unshifted_to_string_alloc(c->syslog_priority >> 3, &fac_str);
                if (r < 0)
                        fac_str = NULL;

                r = log_level_to_string_alloc(LOG_PRI(c->syslog_priority), &lvl_str);
                if (r < 0)
                        lvl_str = NULL;

                fprintf(f,
                        "%sSyslogFacility: %s\n"
                        "%sSyslogLevel: %s\n",
                        prefix, strna(fac_str),
                        prefix, strna(lvl_str));
                free(lvl_str);
                free(fac_str);
        }

        if (c->capabilities) {
                char *t;
                if ((t = cap_to_text(c->capabilities, NULL))) {
                        fprintf(f, "%sCapabilities: %s\n",
                                prefix, t);
                        cap_free(t);
                }
        }

        if (c->secure_bits)
                fprintf(f, "%sSecure Bits:%s%s%s%s%s%s\n",
                        prefix,
                        (c->secure_bits & SECURE_KEEP_CAPS) ? " keep-caps" : "",
                        (c->secure_bits & SECURE_KEEP_CAPS_LOCKED) ? " keep-caps-locked" : "",
                        (c->secure_bits & SECURE_NO_SETUID_FIXUP) ? " no-setuid-fixup" : "",
                        (c->secure_bits & SECURE_NO_SETUID_FIXUP_LOCKED) ? " no-setuid-fixup-locked" : "",
                        (c->secure_bits & SECURE_NOROOT) ? " noroot" : "",
                        (c->secure_bits & SECURE_NOROOT_LOCKED) ? "noroot-locked" : "");

        if (c->capability_bounding_set_drop) {
                unsigned long l;
                fprintf(f, "%sCapabilityBoundingSet:", prefix);

                for (l = 0; l <= cap_last_cap(); l++)
                        if (!(c->capability_bounding_set_drop & ((uint64_t) 1ULL << (uint64_t) l))) {
                                char *t;

                                if ((t = cap_to_name(l))) {
                                        fprintf(f, " %s", t);
                                        cap_free(t);
                                }
                        }

                fputs("\n", f);
        }

        if (c->user)
                fprintf(f, "%sUser: %s\n", prefix, c->user);
        if (c->group)
                fprintf(f, "%sGroup: %s\n", prefix, c->group);

        if (strv_length(c->supplementary_groups) > 0) {
                fprintf(f, "%sSupplementaryGroups:", prefix);
                strv_fprintf(f, c->supplementary_groups);
                fputs("\n", f);
        }

        if (c->pam_name)
                fprintf(f, "%sPAMName: %s\n", prefix, c->pam_name);

        if (strv_length(c->read_write_dirs) > 0) {
                fprintf(f, "%sReadWriteDirs:", prefix);
                strv_fprintf(f, c->read_write_dirs);
                fputs("\n", f);
        }

        if (strv_length(c->read_only_dirs) > 0) {
                fprintf(f, "%sReadOnlyDirs:", prefix);
                strv_fprintf(f, c->read_only_dirs);
                fputs("\n", f);
        }

        if (strv_length(c->inaccessible_dirs) > 0) {
                fprintf(f, "%sInaccessibleDirs:", prefix);
                strv_fprintf(f, c->inaccessible_dirs);
                fputs("\n", f);
        }

        if (c->utmp_id)
                fprintf(f,
                        "%sUtmpIdentifier: %s\n",
                        prefix, c->utmp_id);
}

void exec_status_start(ExecStatus *s, pid_t pid) {
        assert(s);

        zero(*s);
        s->pid = pid;
        dual_timestamp_get(&s->start_timestamp);
}

void exec_status_exit(ExecStatus *s, ExecContext *context, pid_t pid, int code, int status) {
        assert(s);

        if (s->pid && s->pid != pid)
                zero(*s);

        s->pid = pid;
        dual_timestamp_get(&s->exit_timestamp);

        s->code = code;
        s->status = status;

        if (context) {
                if (context->utmp_id)
                        utmp_put_dead_process(context->utmp_id, pid, code, status);

                exec_context_tty_reset(context);
        }
}

void exec_status_dump(ExecStatus *s, FILE *f, const char *prefix) {
        char buf[FORMAT_TIMESTAMP_MAX];

        assert(s);
        assert(f);

        if (!prefix)
                prefix = "";

        if (s->pid <= 0)
                return;

        fprintf(f,
                "%sPID: %lu\n",
                prefix, (unsigned long) s->pid);

        if (s->start_timestamp.realtime > 0)
                fprintf(f,
                        "%sStart Timestamp: %s\n",
                        prefix, format_timestamp(buf, sizeof(buf), s->start_timestamp.realtime));

        if (s->exit_timestamp.realtime > 0)
                fprintf(f,
                        "%sExit Timestamp: %s\n"
                        "%sExit Code: %s\n"
                        "%sExit Status: %i\n",
                        prefix, format_timestamp(buf, sizeof(buf), s->exit_timestamp.realtime),
                        prefix, sigchld_code_to_string(s->code),
                        prefix, s->status);
}

char *exec_command_line(char **argv) {
        size_t k;
        char *n, *p, **a;
        bool first = true;

        assert(argv);

        k = 1;
        STRV_FOREACH(a, argv)
                k += strlen(*a)+3;

        if (!(n = new(char, k)))
                return NULL;

        p = n;
        STRV_FOREACH(a, argv) {

                if (!first)
                        *(p++) = ' ';
                else
                        first = false;

                if (strpbrk(*a, WHITESPACE)) {
                        *(p++) = '\'';
                        p = stpcpy(p, *a);
                        *(p++) = '\'';
                } else
                        p = stpcpy(p, *a);

        }

        *p = 0;

        /* FIXME: this doesn't really handle arguments that have
         * spaces and ticks in them */

        return n;
}

void exec_command_dump(ExecCommand *c, FILE *f, const char *prefix) {
        char *p2;
        const char *prefix2;

        char *cmd;

        assert(c);
        assert(f);

        if (!prefix)
                prefix = "";
        p2 = strappend(prefix, "\t");
        prefix2 = p2 ? p2 : prefix;

        cmd = exec_command_line(c->argv);

        fprintf(f,
                "%sCommand Line: %s\n",
                prefix, cmd ? cmd : strerror(ENOMEM));

        free(cmd);

        exec_status_dump(&c->exec_status, f, prefix2);

        free(p2);
}

void exec_command_dump_list(ExecCommand *c, FILE *f, const char *prefix) {
        assert(f);

        if (!prefix)
                prefix = "";

        LIST_FOREACH(command, c, c)
                exec_command_dump(c, f, prefix);
}

void exec_command_append_list(ExecCommand **l, ExecCommand *e) {
        ExecCommand *end;

        assert(l);
        assert(e);

        if (*l) {
                /* It's kind of important, that we keep the order here */
                LIST_FIND_TAIL(ExecCommand, command, *l, end);
                LIST_INSERT_AFTER(ExecCommand, command, *l, end, e);
        } else
              *l = e;
}

int exec_command_set(ExecCommand *c, const char *path, ...) {
        va_list ap;
        char **l, *p;

        assert(c);
        assert(path);

        va_start(ap, path);
        l = strv_new_ap(path, ap);
        va_end(ap);

        if (!l)
                return -ENOMEM;

        if (!(p = strdup(path))) {
                strv_free(l);
                return -ENOMEM;
        }

        free(c->path);
        c->path = p;

        strv_free(c->argv);
        c->argv = l;

        return 0;
}

static const char* const exec_input_table[_EXEC_INPUT_MAX] = {
        [EXEC_INPUT_NULL] = "null",
        [EXEC_INPUT_TTY] = "tty",
        [EXEC_INPUT_TTY_FORCE] = "tty-force",
        [EXEC_INPUT_TTY_FAIL] = "tty-fail",
        [EXEC_INPUT_SOCKET] = "socket"
};

DEFINE_STRING_TABLE_LOOKUP(exec_input, ExecInput);

static const char* const exec_output_table[_EXEC_OUTPUT_MAX] = {
        [EXEC_OUTPUT_INHERIT] = "inherit",
        [EXEC_OUTPUT_NULL] = "null",
        [EXEC_OUTPUT_TTY] = "tty",
        [EXEC_OUTPUT_SYSLOG] = "syslog",
        [EXEC_OUTPUT_SYSLOG_AND_CONSOLE] = "syslog+console",
        [EXEC_OUTPUT_KMSG] = "kmsg",
        [EXEC_OUTPUT_KMSG_AND_CONSOLE] = "kmsg+console",
        [EXEC_OUTPUT_JOURNAL] = "journal",
        [EXEC_OUTPUT_JOURNAL_AND_CONSOLE] = "journal+console",
        [EXEC_OUTPUT_SOCKET] = "socket"
};

DEFINE_STRING_TABLE_LOOKUP(exec_output, ExecOutput);