sd-daemon: introduce sd_watchdog_enabled() for parsing $WATCHDOG_USEC

[thirdparty/systemd.git] / src / core / execute.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 <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>
#include <glob.h>
#include <libgen.h>
#undef basename

#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 "sd-messages.h"
#include "ioprio.h"
#include "securebits.h"
#include "namespace.h"
#include "tcpwrap.h"
#include "exit-status.h"
#include "missing.h"
#include "utmp-wtmp.h"
#include "def.h"
#include "path-util.h"
#include "syscall-list.h"
#include "env-util.h"
#include "fileio.h"
#include "unit.h"
#include "async.h"

#define IDLE_TIMEOUT_USEC (5*USEC_PER_SEC)
#define IDLE_TIMEOUT2_USEC (1*USEC_PER_SEC)

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

#define SNDBUF_SIZE (8*1024*1024)

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;
}

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

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

        return "/dev/console";
}

static 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 bool is_terminal_output(ExecOutput o) {
        return
                o == EXEC_OUTPUT_TTY ||
                o == EXEC_OUTPUT_SYSLOG_AND_CONSOLE ||
                o == EXEC_OUTPUT_KMSG_AND_CONSOLE ||
                o == EXEC_OUTPUT_JOURNAL_AND_CONSOLE;
}

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

        assert(nfd >= 0);

        fd = open("/dev/null", flags|O_NOCTTY);
        if (fd < 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 = {
                .un.sun_family = AF_UNIX,
                .un.sun_path = "/run/systemd/journal/stdout",
        };

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

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

        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;
        }

        fd_inc_sndbuf(fd, SNDBUF_SIZE);

        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,
                is_terminal_output(output));

        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;

                fd = acquire_terminal(tty_path(context),
                                      i == EXEC_INPUT_TTY_FAIL,
                                      i == EXEC_INPUT_TTY_FORCE,
                                      false,
                                      (usec_t) -1);
                if (fd < 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 fileno, int socket_fd, const char *ident, const char *unit_id, bool apply_tty_stdin) {
        ExecOutput o;
        ExecInput i;
        int r;

        assert(context);
        assert(ident);

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

        if (fileno == STDERR_FILENO) {
                ExecOutput e;
                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 fileno;

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

                o = e;

        } else if (o == 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, 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, fileno) < 0 ? -errno : fileno;

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

                /* We need to open /dev/null here anew, to get the right access mode. */
                return open_null_as(O_WRONLY, fileno);
        }

        switch (o) {

        case EXEC_OUTPUT_NULL:
                return open_null_as(O_WRONLY, fileno);

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

                /* We don't reset the terminal if this is just about output */
                return open_terminal_as(tty_path(context), O_WRONLY, 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:
                r = connect_logger_as(context, o, ident, unit_id, fileno);
                if (r < 0) {
                        log_struct_unit(LOG_CRIT, unit_id,
                                "MESSAGE=Failed to connect std%s of %s to the journal socket: %s",
                                fileno == STDOUT_FILENO ? "out" : "err",
                                unit_id, strerror(-r),
                                "ERRNO=%d", -r,
                                NULL);
                        r = open_null_as(O_WRONLY, fileno);
                }
                return r;

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

_printf_(1, 2) 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, while we drop privileges. */
                if (uid != 0) {
                        int sb = context->secure_bits | 1<<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;
        int flags = 0;

        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 (log_get_max_level() < LOG_PRI(LOG_DEBUG))
                flags |= PAM_SILENT;

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

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

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

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

        close_session = true;

        e = pam_getenvlist(handle);
        if (!e) {
                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();

        pam_pid = fork();
        if (pam_pid < 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) {
                        pam_code = pam_close_session(handle, flags);
                        if (pam_code != PAM_SUCCESS)
                                goto child_finish;
                }

                r = 0;

        child_finish:
                pam_end(handle, pam_code | flags);
                _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) {
                log_error("PAM failed: %s", pam_strerror(handle, pam_code));
                err = -EPERM;  /* PAM errors do not map to errno */
        } else {
                log_error("PAM failed: %m");
                err = -errno;
        }

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

                pam_end(handle, pam_code | flags);
        }

        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 = basename(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, INDEX_TO_SYSCALL(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 */
        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;
}

static void do_idle_pipe_dance(int idle_pipe[4]) {
        assert(idle_pipe);

        if (idle_pipe[1] >= 0)
                close_nointr_nofail(idle_pipe[1]);
        if (idle_pipe[2] >= 0)
                close_nointr_nofail(idle_pipe[2]);

        if (idle_pipe[0] >= 0) {
                int r;

                r = fd_wait_for_event(idle_pipe[0], POLLHUP, IDLE_TIMEOUT_USEC);

                if (idle_pipe[3] >= 0 && r == 0 /* timeout */) {
                        /* Signal systemd that we are bored and want to continue. */
                        write(idle_pipe[3], "x", 1);

                        /* Wait for systemd to react to the signal above. */
                        fd_wait_for_event(idle_pipe[0], POLLHUP, IDLE_TIMEOUT2_USEC);
                }

                close_nointr_nofail(idle_pipe[0]);

        }

        if (idle_pipe[3] >= 0)
                close_nointr_nofail(idle_pipe[3]);
}

static int build_environment(
                ExecContext *c,
                unsigned n_fds,
                usec_t watchdog_usec,
                const char *home,
                const char *username,
                const char *shell,
                char ***ret) {

        _cleanup_strv_free_ char **our_env = NULL;
        unsigned n_env = 0;
        char *x;

        assert(c);
        assert(ret);

        our_env = new0(char*, 10);
        if (!our_env)
                return -ENOMEM;

        if (n_fds > 0) {
                if (asprintf(&x, "LISTEN_PID=%lu", (unsigned long) getpid()) < 0)
                        return -ENOMEM;
                our_env[n_env++] = x;

                if (asprintf(&x, "LISTEN_FDS=%u", n_fds) < 0)
                        return -ENOMEM;
                our_env[n_env++] = x;
        }

        if (watchdog_usec > 0) {
                if (asprintf(&x, "WATCHDOG_PID=%lu", (unsigned long) getpid()) < 0)
                        return -ENOMEM;
                our_env[n_env++] = x;

                if (asprintf(&x, "WATCHDOG_USEC=%llu", (unsigned long long) watchdog_usec) < 0)
                        return -ENOMEM;
                our_env[n_env++] = x;
        }

        if (home) {
                x = strappend("HOME=", home);
                if (!x)
                        return -ENOMEM;
                our_env[n_env++] = x;
        }

        if (username) {
                x = strappend("LOGNAME=", username);
                if (!x)
                        return -ENOMEM;
                our_env[n_env++] = x;

                x = strappend("USER=", username);
                if (!x)
                        return -ENOMEM;
                our_env[n_env++] = x;
        }

        if (shell) {
                x = strappend("SHELL=", shell);
                if (!x)
                        return -ENOMEM;
                our_env[n_env++] = x;
        }

        if (is_terminal_input(c->std_input) ||
            c->std_output == EXEC_OUTPUT_TTY ||
            c->std_error == EXEC_OUTPUT_TTY ||
            c->tty_path) {

                x = strdup(default_term_for_tty(tty_path(c)));
                if (!x)
                        return -ENOMEM;
                our_env[n_env++] = x;
        }

        our_env[n_env++] = NULL;
        assert(n_env <= 10);

        *ret = our_env;
        our_env = NULL;

        return 0;
}

int exec_spawn(ExecCommand *command,
               char **argv,
               ExecContext *context,
               int fds[], unsigned n_fds,
               char **environment,
               bool apply_permissions,
               bool apply_chroot,
               bool apply_tty_stdin,
               bool confirm_spawn,
               CGroupControllerMask cgroup_supported,
               const char *cgroup_path,
               const char *unit_id,
               usec_t watchdog_usec,
               int idle_pipe[4],
               ExecRuntime *runtime,
               pid_t *ret) {

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

        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_unit(LOG_ERR,
                           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_unit(LOG_DEBUG,
                        unit_id,
                        "EXECUTABLE=%s", command->path,
                        "MESSAGE=About to execute: %s", line,
                        NULL);
        free(line);

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

        if (pid == 0) {
                _cleanup_strv_free_ char **our_env = NULL, **pam_env = NULL, **final_env = NULL, **final_argv = NULL;
                const char *username = NULL, *home = NULL, *shell = NULL;
                unsigned n_dont_close = 0;
                int dont_close[n_fds + 3];
                uid_t uid = (uid_t) -1;
                gid_t gid = (gid_t) -1;
                sigset_t ss;
                int i, err;

                /* 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)
                        do_idle_pipe_dance(idle_pipe);

                /* Close sockets very early to make sure we don't
                 * block init reexecution because it cannot bind its
                 * sockets */
                log_forget_fds();

                if (socket_fd >= 0)
                        dont_close[n_dont_close++] = socket_fd;
                if (n_fds > 0) {
                        memcpy(dont_close + n_dont_close, fds, sizeof(int) * n_fds);
                        n_dont_close += n_fds;
                }
                if (runtime) {
                        if (runtime->netns_storage_socket[0] >= 0)
                                dont_close[n_dont_close++] = runtime->netns_storage_socket[0];
                        if (runtime->netns_storage_socket[1] >= 0)
                                dont_close[n_dont_close++] = runtime->netns_storage_socket[1];
                }

                err = close_all_fds(dont_close, n_dont_close);
                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, STDOUT_FILENO, socket_fd, basename(command->path), unit_id, apply_tty_stdin);
                if (err < 0) {
                        r = EXIT_STDOUT;
                        goto fail_child;
                }

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

                if (cgroup_path) {
                        err = cg_attach_everywhere(cgroup_supported, cgroup_path, 0);
                        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_string_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 = {
                                .sched_priority = context->cpu_sched_priority,
                        };

                        r = sched_setscheduler(0,
                                               context->cpu_sched_policy |
                                               (context->cpu_sched_reset_on_fork ?
                                                SCHED_RESET_ON_FORK : 0),
                                               &param);
                        if (r < 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, &shell);
                        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;
                                }
                        }
                }

#ifdef HAVE_PAM
                if (cgroup_path && context->user && context->pam_name) {
                        err = cg_set_task_access(SYSTEMD_CGROUP_CONTROLLER, cgroup_path, 0644, uid, gid);
                        if (err < 0) {
                                r = EXIT_CGROUP;
                                goto fail_child;
                        }


                        err = cg_set_group_access(SYSTEMD_CGROUP_CONTROLLER, cgroup_path, 0755, uid, gid);
                        if (err < 0) {
                                r = EXIT_CGROUP;
                                goto fail_child;
                        }
                }
#endif

                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 && runtime && runtime->netns_storage_socket[0] >= 0) {
                        err = setup_netns(runtime->netns_storage_socket);
                        if (err < 0) {
                                r = EXIT_NETWORK;
                                goto fail_child;
                        }
                }

                if (!strv_isempty(context->read_write_dirs) ||
                    !strv_isempty(context->read_only_dirs) ||
                    !strv_isempty(context->inaccessible_dirs) ||
                    context->mount_flags != 0 ||
                    (context->private_tmp && runtime && (runtime->tmp_dir || runtime->var_tmp_dir))) {

                        char *tmp = NULL, *var = NULL;

                        /* The runtime struct only contains the parent
                         * of the private /tmp, which is
                         * non-accessible to world users. Inside of it
                         * there's a /tmp that is sticky, and that's
                         * the one we want to use here. */

                        if (context->private_tmp && runtime) {
                                if (runtime->tmp_dir)
                                        tmp = strappenda(runtime->tmp_dir, "/tmp");
                                if (runtime->var_tmp_dir)
                                        var = strappenda(runtime->var_tmp_dir, "/tmp");
                        }

                        err = setup_namespace(
                                        context->read_write_dirs,
                                        context->read_only_dirs,
                                        context->inaccessible_dirs,
                                        tmp,
                                        var,
                                        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 {
                        _cleanup_free_ char *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;
                                }
                        }
                }

                err = build_environment(context, n_fds, watchdog_usec, home, username, shell, &our_env);
                if (r < 0) {
                        r = EXIT_MEMORY;
                        goto fail_child;
                }

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

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

                final_env = strv_env_clean(final_env);

                if (_unlikely_(log_get_max_level() >= LOG_PRI(LOG_DEBUG))) {
                        line = exec_command_line(final_argv);
                        if (line) {
                                log_open();
                                log_struct_unit(LOG_DEBUG,
                                                unit_id,
                                                "EXECUTABLE=%s", command->path,
                                                "MESSAGE=Executing: %s", line,
                                                NULL);
                                log_close();
                                free(line);
                                line = NULL;
                        }
                }
                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_unit(LOG_DEBUG,
                        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_path)
                cg_attach(SYSTEMD_CGROUP_CONTROLLER, cgroup_path, pid);

        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->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(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;
                _cleanup_globfree_ glob_t pglob = {};
                int count, n;

                fn = *i;

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

                if (!path_is_absolute(fn)) {
                        if (ignore)
                                continue;

                        strv_free(r);
                        return -EINVAL;
                }

                /* Filename supports globbing, take all matching files */
                errno = 0;
                if (glob(fn, 0, NULL, &pglob) != 0) {
                        if (ignore)
                                continue;

                        strv_free(r);
                        return errno ? -errno : -EINVAL;
                }
                count = pglob.gl_pathc;
                if (count == 0) {
                        if (ignore)
                                continue;

                        strv_free(r);
                        return -EINVAL;
                }
                for (n = 0; n < count; n++) {
                        k = load_env_file(pglob.gl_pathv[n], NULL, &p);
                        if (k < 0) {
                                if (ignore)
                                        continue;

                                strv_free(r);
                                return k;
                        }
                        /* Log invalid environment variables with filename */
                        if (p)
                                p = strv_env_clean_log(p, pglob.gl_pathv[n]);

                        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 bool tty_may_match_dev_console(const char *tty) {
        char *active = NULL, *console;
        bool b;

        if (startswith(tty, "/dev/"))
                tty += 5;

        /* trivial identity? */
        if (streq(tty, "console"))
                return true;

        console = resolve_dev_console(&active);
        /* if we could not resolve, assume it may */
        if (!console)
                return true;

        /* "tty0" means the active VC, so it may be the same sometimes */
        b = streq(console, tty) || (streq(console, "tty0") && tty_is_vc(tty));
        free(active);

        return b;
}

bool exec_context_may_touch_console(ExecContext *ec) {
        return (ec->tty_reset || ec->tty_vhangup || ec->tty_vt_disallocate ||
                is_terminal_input(ec->std_input) ||
                is_terminal_output(ec->std_output) ||
                is_terminal_output(ec->std_error)) &&
               tty_may_match_dev_console(tty_path(ec));
}

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);

        prefix = strempty(prefix);

        fprintf(f,
                "%sUMask: %04o\n"
                "%sWorkingDirectory: %s\n"
                "%sRootDirectory: %s\n"
                "%sNonBlocking: %s\n"
                "%sPrivateTmp: %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->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 & 1<<SECURE_KEEP_CAPS) ? " keep-caps" : "",
                        (c->secure_bits & 1<<SECURE_KEEP_CAPS_LOCKED) ? " keep-caps-locked" : "",
                        (c->secure_bits & 1<<SECURE_NO_SETUID_FIXUP) ? " no-setuid-fixup" : "",
                        (c->secure_bits & 1<<SECURE_NO_SETUID_FIXUP_LOCKED) ? " no-setuid-fixup-locked" : "",
                        (c->secure_bits & 1<<SECURE_NOROOT) ? " noroot" : "",
                        (c->secure_bits & 1<<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(command, *l, end);
                LIST_INSERT_AFTER(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;

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

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

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

        return 0;
}

static int exec_runtime_allocate(ExecRuntime **rt) {

        if (*rt)
                return 0;

        *rt = new0(ExecRuntime, 1);
        if (!rt)
                return -ENOMEM;

        (*rt)->n_ref = 1;
        (*rt)->netns_storage_socket[0] = (*rt)->netns_storage_socket[1] = -1;

        return 0;
}

int exec_runtime_make(ExecRuntime **rt, ExecContext *c, const char *id) {
        int r;

        assert(rt);
        assert(c);
        assert(id);

        if (*rt)
                return 1;

        if (!c->private_network && !c->private_tmp)
                return 0;

        r = exec_runtime_allocate(rt);
        if (r < 0)
                return r;

        if (c->private_network && (*rt)->netns_storage_socket[0] < 0) {
                if (socketpair(AF_UNIX, SOCK_DGRAM, 0, (*rt)->netns_storage_socket) < 0)
                        return -errno;
        }

        if (c->private_tmp && !(*rt)->tmp_dir) {
                r = setup_tmp_dirs(id, &(*rt)->tmp_dir, &(*rt)->var_tmp_dir);
                if (r < 0)
                        return r;
        }

        return 1;
}

ExecRuntime *exec_runtime_ref(ExecRuntime *r) {
        assert(r);
        assert(r->n_ref > 0);

        r->n_ref++;
        return r;
}

ExecRuntime *exec_runtime_unref(ExecRuntime *r) {

        if (!r)
                return NULL;

        assert(r->n_ref > 0);

        r->n_ref--;
        if (r->n_ref <= 0) {
                free(r->tmp_dir);
                free(r->var_tmp_dir);
                close_pipe(r->netns_storage_socket);
                free(r);
        }

        return NULL;
}

int exec_runtime_serialize(ExecRuntime *rt, Unit *u, FILE *f, FDSet *fds) {
        assert(u);
        assert(f);
        assert(fds);

        if (!rt)
                return 0;

        if (rt->tmp_dir)
                unit_serialize_item(u, f, "tmp-dir", rt->tmp_dir);

        if (rt->var_tmp_dir)
                unit_serialize_item(u, f, "var-tmp-dir", rt->var_tmp_dir);

        if (rt->netns_storage_socket[0] >= 0) {
                int copy;

                copy = fdset_put_dup(fds, rt->netns_storage_socket[0]);
                if (copy < 0)
                        return copy;

                unit_serialize_item_format(u, f, "netns-socket-0", "%i", copy);
        }

        if (rt->netns_storage_socket[1] >= 0) {
                int copy;

                copy = fdset_put_dup(fds, rt->netns_storage_socket[1]);
                if (copy < 0)
                        return copy;

                unit_serialize_item_format(u, f, "netns-socket-1", "%i", copy);
        }

        return 0;
}

int exec_runtime_deserialize_item(ExecRuntime **rt, Unit *u, const char *key, const char *value, FDSet *fds) {
        int r;

        assert(rt);
        assert(key);
        assert(value);

        if (streq(key, "tmp-dir")) {
                char *copy;

                r = exec_runtime_allocate(rt);
                if (r < 0)
                        return r;

                copy = strdup(value);
                if (!copy)
                        return log_oom();

                free((*rt)->tmp_dir);
                (*rt)->tmp_dir = copy;

        } else if (streq(key, "var-tmp-dir")) {
                char *copy;

                r = exec_runtime_allocate(rt);
                if (r < 0)
                        return r;

                copy = strdup(value);
                if (!copy)
                        return log_oom();

                free((*rt)->var_tmp_dir);
                (*rt)->var_tmp_dir = copy;

        } else if (streq(key, "netns-socket-0")) {
                int fd;

                r = exec_runtime_allocate(rt);
                if (r < 0)
                        return r;

                if (safe_atoi(value, &fd) < 0 || !fdset_contains(fds, fd))
                        log_debug_unit(u->id, "Failed to parse netns socket value %s", value);
                else {
                        if ((*rt)->netns_storage_socket[0] >= 0)
                                close_nointr_nofail((*rt)->netns_storage_socket[0]);

                        (*rt)->netns_storage_socket[0] = fdset_remove(fds, fd);
                }
        } else if (streq(key, "netns-socket-1")) {
                int fd;

                r = exec_runtime_allocate(rt);
                if (r < 0)
                        return r;

                if (safe_atoi(value, &fd) < 0 || !fdset_contains(fds, fd))
                        log_debug_unit(u->id, "Failed to parse netns socket value %s", value);
                else {
                        if ((*rt)->netns_storage_socket[1] >= 0)
                                close_nointr_nofail((*rt)->netns_storage_socket[1]);

                        (*rt)->netns_storage_socket[1] = fdset_remove(fds, fd);
                }
        } else
                return 0;

        return 1;
}

static void *remove_tmpdir_thread(void *p) {
        _cleanup_free_ char *path = p;

        rm_rf_dangerous(path, false, true, false);
        return NULL;
}

void exec_runtime_destroy(ExecRuntime *rt) {
        if (!rt)
                return;

        /* If there are multiple users of this, let's leave the stuff around */
        if (rt->n_ref > 1)
                return;

        if (rt->tmp_dir) {
                log_debug("Spawning thread to nuke %s", rt->tmp_dir);
                asynchronous_job(remove_tmpdir_thread, rt->tmp_dir);
                rt->tmp_dir = NULL;
        }

        if (rt->var_tmp_dir) {
                log_debug("Spawning thread to nuke %s", rt->var_tmp_dir);
                asynchronous_job(remove_tmpdir_thread, rt->var_tmp_dir);
                rt->var_tmp_dir = NULL;
        }

        close_pipe(rt->netns_storage_socket);
}

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);