diff options
Diffstat (limited to 'src/core/execute.c')
| -rw-r--r-- | src/core/execute.c | 7278 |
1 files changed, 7278 insertions, 0 deletions
diff --git a/src/core/execute.c b/src/core/execute.c new file mode 100644 index 0000000..9715d02 --- /dev/null +++ b/src/core/execute.c @@ -0,0 +1,7278 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <errno.h> +#include <fcntl.h> +#include <poll.h> +#include <sys/eventfd.h> +#include <sys/file.h> +#include <sys/ioctl.h> +#include <sys/mman.h> +#include <sys/mount.h> +#include <sys/personality.h> +#include <sys/prctl.h> +#include <sys/shm.h> +#include <sys/types.h> +#include <sys/un.h> +#include <unistd.h> +#include <utmpx.h> + +#if HAVE_PAM +#include <security/pam_appl.h> +#endif + +#if HAVE_SELINUX +#include <selinux/selinux.h> +#endif + +#if HAVE_SECCOMP +#include <seccomp.h> +#endif + +#if HAVE_APPARMOR +#include <sys/apparmor.h> +#endif + +#include "sd-messages.h" + +#include "acl-util.h" +#include "af-list.h" +#include "alloc-util.h" +#if HAVE_APPARMOR +#include "apparmor-util.h" +#endif +#include "async.h" +#include "barrier.h" +#include "bpf-lsm.h" +#include "cap-list.h" +#include "capability-util.h" +#include "cgroup-setup.h" +#include "chase-symlinks.h" +#include "chown-recursive.h" +#include "cpu-set-util.h" +#include "creds-util.h" +#include "data-fd-util.h" +#include "def.h" +#include "env-file.h" +#include "env-util.h" +#include "errno-list.h" +#include "escape.h" +#include "execute.h" +#include "exit-status.h" +#include "fd-util.h" +#include "fileio.h" +#include "format-util.h" +#include "glob-util.h" +#include "hexdecoct.h" +#include "io-util.h" +#include "ioprio-util.h" +#include "label.h" +#include "log.h" +#include "macro.h" +#include "manager.h" +#include "manager-dump.h" +#include "memory-util.h" +#include "missing_fs.h" +#include "missing_ioprio.h" +#include "mkdir-label.h" +#include "mount-util.h" +#include "mountpoint-util.h" +#include "namespace.h" +#include "parse-util.h" +#include "path-util.h" +#include "process-util.h" +#include "random-util.h" +#include "recurse-dir.h" +#include "rlimit-util.h" +#include "rm-rf.h" +#if HAVE_SECCOMP +#include "seccomp-util.h" +#endif +#include "securebits-util.h" +#include "selinux-util.h" +#include "signal-util.h" +#include "smack-util.h" +#include "socket-util.h" +#include "sort-util.h" +#include "special.h" +#include "stat-util.h" +#include "string-table.h" +#include "string-util.h" +#include "strv.h" +#include "syslog-util.h" +#include "terminal-util.h" +#include "tmpfile-util.h" +#include "umask-util.h" +#include "unit-serialize.h" +#include "user-util.h" +#include "utmp-wtmp.h" + +#define IDLE_TIMEOUT_USEC (5*USEC_PER_SEC) +#define IDLE_TIMEOUT2_USEC (1*USEC_PER_SEC) + +#define SNDBUF_SIZE (8*1024*1024) + +static int shift_fds(int fds[], size_t n_fds) { + if (n_fds <= 0) + return 0; + + /* Modifies the fds array! (sorts it) */ + + assert(fds); + + for (int start = 0;;) { + int restart_from = -1; + + for (int i = start; i < (int) n_fds; i++) { + int nfd; + + /* Already at right index? */ + if (fds[i] == i+3) + continue; + + nfd = fcntl(fds[i], F_DUPFD, i + 3); + if (nfd < 0) + return -errno; + + safe_close(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 flag_fds(const int fds[], size_t n_socket_fds, size_t n_storage_fds, bool nonblock) { + size_t n_fds; + int r; + + n_fds = n_socket_fds + n_storage_fds; + if (n_fds <= 0) + return 0; + + assert(fds); + assert(fds || n_fds == 0); + + /* Drops/Sets O_NONBLOCK and FD_CLOEXEC from the file flags. + * O_NONBLOCK only applies to socket activation though. */ + + for (size_t i = 0; i < n_fds; i++) { + + if (i < n_socket_fds) { + r = fd_nonblock(fds[i], nonblock); + if (r < 0) + return r; + } + + /* We unconditionally drop FD_CLOEXEC from the fds, + * since after all we want to pass these fds to our + * children */ + + r = fd_cloexec(fds[i], false); + if (r < 0) + return r; + } + + return 0; +} + +static const char *exec_context_tty_path(const ExecContext *context) { + assert(context); + + if (context->stdio_as_fds) + return NULL; + + if (context->tty_path) + return context->tty_path; + + return "/dev/console"; +} + +static void exec_context_tty_reset(const ExecContext *context, const ExecParameters *p) { + const char *path; + + assert(context); + + path = exec_context_tty_path(context); + + if (context->tty_vhangup) { + if (p && p->stdin_fd >= 0) + (void) terminal_vhangup_fd(p->stdin_fd); + else if (path) + (void) terminal_vhangup(path); + } + + if (context->tty_reset) { + if (p && p->stdin_fd >= 0) + (void) reset_terminal_fd(p->stdin_fd, true); + else if (path) + (void) reset_terminal(path); + } + + if (p && p->stdin_fd >= 0) + (void) terminal_set_size_fd(p->stdin_fd, path, context->tty_rows, context->tty_cols); + + if (context->tty_vt_disallocate && path) + (void) vt_disallocate(path); +} + +static bool is_terminal_input(ExecInput i) { + return IN_SET(i, + EXEC_INPUT_TTY, + EXEC_INPUT_TTY_FORCE, + EXEC_INPUT_TTY_FAIL); +} + +static bool is_terminal_output(ExecOutput o) { + return IN_SET(o, + EXEC_OUTPUT_TTY, + EXEC_OUTPUT_KMSG_AND_CONSOLE, + EXEC_OUTPUT_JOURNAL_AND_CONSOLE); +} + +static bool is_kmsg_output(ExecOutput o) { + return IN_SET(o, + EXEC_OUTPUT_KMSG, + EXEC_OUTPUT_KMSG_AND_CONSOLE); +} + +static bool exec_context_needs_term(const ExecContext *c) { + assert(c); + + /* Return true if the execution context suggests we should set $TERM to something useful. */ + + if (is_terminal_input(c->std_input)) + return true; + + if (is_terminal_output(c->std_output)) + return true; + + if (is_terminal_output(c->std_error)) + return true; + + return !!c->tty_path; +} + +static int open_null_as(int flags, int nfd) { + int fd; + + assert(nfd >= 0); + + fd = open("/dev/null", flags|O_NOCTTY); + if (fd < 0) + return -errno; + + return move_fd(fd, nfd, false); +} + +static int connect_journal_socket( + int fd, + const char *log_namespace, + uid_t uid, + gid_t gid) { + + uid_t olduid = UID_INVALID; + gid_t oldgid = GID_INVALID; + const char *j; + int r; + + j = log_namespace ? + strjoina("/run/systemd/journal.", log_namespace, "/stdout") : + "/run/systemd/journal/stdout"; + + if (gid_is_valid(gid)) { + oldgid = getgid(); + + if (setegid(gid) < 0) + return -errno; + } + + if (uid_is_valid(uid)) { + olduid = getuid(); + + if (seteuid(uid) < 0) { + r = -errno; + goto restore_gid; + } + } + + r = connect_unix_path(fd, AT_FDCWD, j); + + /* If we fail to restore the uid or gid, things will likely fail later on. This should only happen if + an LSM interferes. */ + + if (uid_is_valid(uid)) + (void) seteuid(olduid); + + restore_gid: + if (gid_is_valid(gid)) + (void) setegid(oldgid); + + return r; +} + +static int connect_logger_as( + const Unit *unit, + const ExecContext *context, + const ExecParameters *params, + ExecOutput output, + const char *ident, + int nfd, + uid_t uid, + gid_t gid) { + + _cleanup_close_ int fd = -1; + int r; + + assert(context); + assert(params); + assert(output < _EXEC_OUTPUT_MAX); + assert(ident); + assert(nfd >= 0); + + fd = socket(AF_UNIX, SOCK_STREAM, 0); + if (fd < 0) + return -errno; + + r = connect_journal_socket(fd, context->log_namespace, uid, gid); + if (r < 0) + return r; + + if (shutdown(fd, SHUT_RD) < 0) + return -errno; + + (void) fd_inc_sndbuf(fd, SNDBUF_SIZE); + + if (dprintf(fd, + "%s\n" + "%s\n" + "%i\n" + "%i\n" + "%i\n" + "%i\n" + "%i\n", + context->syslog_identifier ?: ident, + params->flags & EXEC_PASS_LOG_UNIT ? unit->id : "", + context->syslog_priority, + !!context->syslog_level_prefix, + false, + is_kmsg_output(output), + is_terminal_output(output)) < 0) + return -errno; + + return move_fd(TAKE_FD(fd), nfd, false); +} + +static int open_terminal_as(const char *path, int flags, int nfd) { + int fd; + + assert(path); + assert(nfd >= 0); + + fd = open_terminal(path, flags | O_NOCTTY); + if (fd < 0) + return fd; + + return move_fd(fd, nfd, false); +} + +static int acquire_path(const char *path, int flags, mode_t mode) { + _cleanup_close_ int fd = -1; + int r; + + assert(path); + + if (IN_SET(flags & O_ACCMODE, O_WRONLY, O_RDWR)) + flags |= O_CREAT; + + fd = open(path, flags|O_NOCTTY, mode); + if (fd >= 0) + return TAKE_FD(fd); + + if (errno != ENXIO) /* ENXIO is returned when we try to open() an AF_UNIX file system socket on Linux */ + return -errno; + + /* So, it appears the specified path could be an AF_UNIX socket. Let's see if we can connect to it. */ + + fd = socket(AF_UNIX, SOCK_STREAM, 0); + if (fd < 0) + return -errno; + + r = connect_unix_path(fd, AT_FDCWD, path); + if (IN_SET(r, -ENOTSOCK, -EINVAL)) + /* Propagate initial error if we get ENOTSOCK or EINVAL, i.e. we have indication that this + * wasn't an AF_UNIX socket after all */ + return -ENXIO; + if (r < 0) + return r; + + if ((flags & O_ACCMODE) == O_RDONLY) + r = shutdown(fd, SHUT_WR); + else if ((flags & O_ACCMODE) == O_WRONLY) + r = shutdown(fd, SHUT_RD); + else + r = 0; + if (r < 0) + return -errno; + + return TAKE_FD(fd); +} + +static int fixup_input( + const ExecContext *context, + int socket_fd, + bool apply_tty_stdin) { + + ExecInput std_input; + + assert(context); + + std_input = context->std_input; + + 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; + + if (std_input == EXEC_INPUT_DATA && context->stdin_data_size == 0) + return EXEC_INPUT_NULL; + + return std_input; +} + +static int fixup_output(ExecOutput output, int socket_fd) { + + if (output == EXEC_OUTPUT_SOCKET && socket_fd < 0) + return EXEC_OUTPUT_INHERIT; + + return output; +} + +static int setup_input( + const ExecContext *context, + const ExecParameters *params, + int socket_fd, + const int named_iofds[static 3]) { + + ExecInput i; + int r; + + assert(context); + assert(params); + assert(named_iofds); + + if (params->stdin_fd >= 0) { + if (dup2(params->stdin_fd, STDIN_FILENO) < 0) + return -errno; + + /* Try to make this the controlling tty, if it is a tty, and reset it */ + if (isatty(STDIN_FILENO)) { + (void) ioctl(STDIN_FILENO, TIOCSCTTY, context->std_input == EXEC_INPUT_TTY_FORCE); + (void) reset_terminal_fd(STDIN_FILENO, true); + (void) terminal_set_size_fd(STDIN_FILENO, NULL, context->tty_rows, context->tty_cols); + } + + return STDIN_FILENO; + } + + i = fixup_input(context, socket_fd, params->flags & EXEC_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; + + fd = acquire_terminal(exec_context_tty_path(context), + i == EXEC_INPUT_TTY_FAIL ? ACQUIRE_TERMINAL_TRY : + i == EXEC_INPUT_TTY_FORCE ? ACQUIRE_TERMINAL_FORCE : + ACQUIRE_TERMINAL_WAIT, + USEC_INFINITY); + if (fd < 0) + return fd; + + r = terminal_set_size_fd(fd, exec_context_tty_path(context), context->tty_rows, context->tty_cols); + if (r < 0) + return r; + + return move_fd(fd, STDIN_FILENO, false); + } + + case EXEC_INPUT_SOCKET: + assert(socket_fd >= 0); + + return RET_NERRNO(dup2(socket_fd, STDIN_FILENO)); + + case EXEC_INPUT_NAMED_FD: + assert(named_iofds[STDIN_FILENO] >= 0); + + (void) fd_nonblock(named_iofds[STDIN_FILENO], false); + return RET_NERRNO(dup2(named_iofds[STDIN_FILENO], STDIN_FILENO)); + + case EXEC_INPUT_DATA: { + int fd; + + fd = acquire_data_fd(context->stdin_data, context->stdin_data_size, 0); + if (fd < 0) + return fd; + + return move_fd(fd, STDIN_FILENO, false); + } + + case EXEC_INPUT_FILE: { + bool rw; + int fd; + + assert(context->stdio_file[STDIN_FILENO]); + + rw = (context->std_output == EXEC_OUTPUT_FILE && streq_ptr(context->stdio_file[STDIN_FILENO], context->stdio_file[STDOUT_FILENO])) || + (context->std_error == EXEC_OUTPUT_FILE && streq_ptr(context->stdio_file[STDIN_FILENO], context->stdio_file[STDERR_FILENO])); + + fd = acquire_path(context->stdio_file[STDIN_FILENO], rw ? O_RDWR : O_RDONLY, 0666 & ~context->umask); + if (fd < 0) + return fd; + + return move_fd(fd, STDIN_FILENO, false); + } + + default: + assert_not_reached(); + } +} + +static bool can_inherit_stderr_from_stdout( + const ExecContext *context, + ExecOutput o, + ExecOutput e) { + + assert(context); + + /* Returns true, if given the specified STDERR and STDOUT output we can directly dup() the stdout fd to the + * stderr fd */ + + if (e == EXEC_OUTPUT_INHERIT) + return true; + if (e != o) + return false; + + if (e == EXEC_OUTPUT_NAMED_FD) + return streq_ptr(context->stdio_fdname[STDOUT_FILENO], context->stdio_fdname[STDERR_FILENO]); + + if (IN_SET(e, EXEC_OUTPUT_FILE, EXEC_OUTPUT_FILE_APPEND, EXEC_OUTPUT_FILE_TRUNCATE)) + return streq_ptr(context->stdio_file[STDOUT_FILENO], context->stdio_file[STDERR_FILENO]); + + return true; +} + +static int setup_output( + const Unit *unit, + const ExecContext *context, + const ExecParameters *params, + int fileno, + int socket_fd, + const int named_iofds[static 3], + const char *ident, + uid_t uid, + gid_t gid, + dev_t *journal_stream_dev, + ino_t *journal_stream_ino) { + + ExecOutput o; + ExecInput i; + int r; + + assert(unit); + assert(context); + assert(params); + assert(ident); + assert(journal_stream_dev); + assert(journal_stream_ino); + + if (fileno == STDOUT_FILENO && params->stdout_fd >= 0) { + + if (dup2(params->stdout_fd, STDOUT_FILENO) < 0) + return -errno; + + return STDOUT_FILENO; + } + + if (fileno == STDERR_FILENO && params->stderr_fd >= 0) { + if (dup2(params->stderr_fd, STDERR_FILENO) < 0) + return -errno; + + return STDERR_FILENO; + } + + i = fixup_input(context, socket_fd, params->flags & EXEC_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 (can_inherit_stderr_from_stdout(context, o, e)) + return RET_NERRNO(dup2(STDOUT_FILENO, 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(exec_context_tty_path(context), O_WRONLY, fileno); + + /* If the input is connected to anything that's not a /dev/null or a data fd, inherit that... */ + if (!IN_SET(i, EXEC_INPUT_NULL, EXEC_INPUT_DATA)) + return RET_NERRNO(dup2(STDIN_FILENO, 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 RET_NERRNO(dup2(STDIN_FILENO, fileno)); + + /* We don't reset the terminal if this is just about output */ + return open_terminal_as(exec_context_tty_path(context), O_WRONLY, fileno); + + case EXEC_OUTPUT_KMSG: + case EXEC_OUTPUT_KMSG_AND_CONSOLE: + case EXEC_OUTPUT_JOURNAL: + case EXEC_OUTPUT_JOURNAL_AND_CONSOLE: + r = connect_logger_as(unit, context, params, o, ident, fileno, uid, gid); + if (r < 0) { + log_unit_warning_errno(unit, r, "Failed to connect %s to the journal socket, ignoring: %m", + fileno == STDOUT_FILENO ? "stdout" : "stderr"); + r = open_null_as(O_WRONLY, fileno); + } else { + struct stat st; + + /* If we connected this fd to the journal via a stream, patch the device/inode into the passed + * parameters, but only then. This is useful so that we can set $JOURNAL_STREAM that permits + * services to detect whether they are connected to the journal or not. + * + * If both stdout and stderr are connected to a stream then let's make sure to store the data + * about STDERR as that's usually the best way to do logging. */ + + if (fstat(fileno, &st) >= 0 && + (*journal_stream_ino == 0 || fileno == STDERR_FILENO)) { + *journal_stream_dev = st.st_dev; + *journal_stream_ino = st.st_ino; + } + } + return r; + + case EXEC_OUTPUT_SOCKET: + assert(socket_fd >= 0); + + return RET_NERRNO(dup2(socket_fd, fileno)); + + case EXEC_OUTPUT_NAMED_FD: + assert(named_iofds[fileno] >= 0); + + (void) fd_nonblock(named_iofds[fileno], false); + return RET_NERRNO(dup2(named_iofds[fileno], fileno)); + + case EXEC_OUTPUT_FILE: + case EXEC_OUTPUT_FILE_APPEND: + case EXEC_OUTPUT_FILE_TRUNCATE: { + bool rw; + int fd, flags; + + assert(context->stdio_file[fileno]); + + rw = context->std_input == EXEC_INPUT_FILE && + streq_ptr(context->stdio_file[fileno], context->stdio_file[STDIN_FILENO]); + + if (rw) + return RET_NERRNO(dup2(STDIN_FILENO, fileno)); + + flags = O_WRONLY; + if (o == EXEC_OUTPUT_FILE_APPEND) + flags |= O_APPEND; + else if (o == EXEC_OUTPUT_FILE_TRUNCATE) + flags |= O_TRUNC; + + fd = acquire_path(context->stdio_file[fileno], flags, 0666 & ~context->umask); + if (fd < 0) + return fd; + + return move_fd(fd, fileno, 0); + } + + default: + assert_not_reached(); + } +} + +static int chown_terminal(int fd, uid_t uid) { + int r; + + assert(fd >= 0); + + /* Before we chown/chmod the TTY, let's ensure this is actually a tty */ + if (isatty(fd) < 1) { + if (IN_SET(errno, EINVAL, ENOTTY)) + return 0; /* not a tty */ + + return -errno; + } + + /* This might fail. What matters are the results. */ + r = fchmod_and_chown(fd, TTY_MODE, uid, GID_INVALID); + if (r < 0) + return r; + + return 1; +} + +static int setup_confirm_stdio( + const ExecContext *context, + const char *vc, + int *ret_saved_stdin, + int *ret_saved_stdout) { + + _cleanup_close_ int fd = -1, saved_stdin = -1, saved_stdout = -1; + int r; + + assert(ret_saved_stdin); + assert(ret_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) + return -errno; + + fd = acquire_terminal(vc, ACQUIRE_TERMINAL_WAIT, DEFAULT_CONFIRM_USEC); + if (fd < 0) + return fd; + + r = chown_terminal(fd, getuid()); + if (r < 0) + return r; + + r = reset_terminal_fd(fd, true); + if (r < 0) + return r; + + r = terminal_set_size_fd(fd, vc, context->tty_rows, context->tty_cols); + if (r < 0) + return r; + + r = rearrange_stdio(fd, fd, STDERR_FILENO); /* Invalidates 'fd' also on failure */ + TAKE_FD(fd); + if (r < 0) + return r; + + *ret_saved_stdin = TAKE_FD(saved_stdin); + *ret_saved_stdout = TAKE_FD(saved_stdout); + return 0; +} + +static void write_confirm_error_fd(int err, int fd, const Unit *u) { + assert(err < 0); + + if (err == -ETIMEDOUT) + dprintf(fd, "Confirmation question timed out for %s, assuming positive response.\n", u->id); + else { + errno = -err; + dprintf(fd, "Couldn't ask confirmation for %s: %m, assuming positive response.\n", u->id); + } +} + +static void write_confirm_error(int err, const char *vc, const Unit *u) { + _cleanup_close_ int fd = -1; + + assert(vc); + + fd = open_terminal(vc, O_WRONLY|O_NOCTTY|O_CLOEXEC); + if (fd < 0) + return; + + write_confirm_error_fd(err, fd, u); +} + +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; + + *saved_stdin = safe_close(*saved_stdin); + *saved_stdout = safe_close(*saved_stdout); + + return r; +} + +enum { + CONFIRM_PRETEND_FAILURE = -1, + CONFIRM_PRETEND_SUCCESS = 0, + CONFIRM_EXECUTE = 1, +}; + +static int ask_for_confirmation(const ExecContext *context, const char *vc, Unit *u, const char *cmdline) { + int saved_stdout = -1, saved_stdin = -1, r; + _cleanup_free_ char *e = NULL; + char c; + + /* For any internal errors, assume a positive response. */ + r = setup_confirm_stdio(context, vc, &saved_stdin, &saved_stdout); + if (r < 0) { + write_confirm_error(r, vc, u); + return CONFIRM_EXECUTE; + } + + /* confirm_spawn might have been disabled while we were sleeping. */ + if (manager_is_confirm_spawn_disabled(u->manager)) { + r = 1; + goto restore_stdio; + } + + e = ellipsize(cmdline, 60, 100); + if (!e) { + log_oom(); + r = CONFIRM_EXECUTE; + goto restore_stdio; + } + + for (;;) { + r = ask_char(&c, "yfshiDjcn", "Execute %s? [y, f, s – h for help] ", e); + if (r < 0) { + write_confirm_error_fd(r, STDOUT_FILENO, u); + r = CONFIRM_EXECUTE; + goto restore_stdio; + } + + switch (c) { + case 'c': + printf("Resuming normal execution.\n"); + manager_disable_confirm_spawn(); + r = 1; + break; + case 'D': + unit_dump(u, stdout, " "); + continue; /* ask again */ + case 'f': + printf("Failing execution.\n"); + r = CONFIRM_PRETEND_FAILURE; + break; + case 'h': + printf(" c - continue, proceed without asking anymore\n" + " D - dump, show the state of the unit\n" + " f - fail, don't execute the command and pretend it failed\n" + " h - help\n" + " i - info, show a short summary of the unit\n" + " j - jobs, show jobs that are in progress\n" + " s - skip, don't execute the command and pretend it succeeded\n" + " y - yes, execute the command\n"); + continue; /* ask again */ + case 'i': + printf(" Description: %s\n" + " Unit: %s\n" + " Command: %s\n", + u->id, u->description, cmdline); + continue; /* ask again */ + case 'j': + manager_dump_jobs(u->manager, stdout, /* patterns= */ NULL, " "); + continue; /* ask again */ + case 'n': + /* 'n' was removed in favor of 'f'. */ + printf("Didn't understand 'n', did you mean 'f'?\n"); + continue; /* ask again */ + case 's': + printf("Skipping execution.\n"); + r = CONFIRM_PRETEND_SUCCESS; + break; + case 'y': + r = CONFIRM_EXECUTE; + break; + default: + assert_not_reached(); + } + break; + } + +restore_stdio: + restore_confirm_stdio(&saved_stdin, &saved_stdout); + return r; +} + +static int get_fixed_user(const ExecContext *c, const char **user, + uid_t *uid, gid_t *gid, + const char **home, const char **shell) { + int r; + const char *name; + + assert(c); + + if (!c->user) + return 0; + + /* Note that we don't set $HOME or $SHELL if they are not particularly enlightening anyway + * (i.e. are "/" or "/bin/nologin"). */ + + name = c->user; + r = get_user_creds(&name, uid, gid, home, shell, USER_CREDS_CLEAN); + if (r < 0) + return r; + + *user = name; + return 0; +} + +static int get_fixed_group(const ExecContext *c, const char **group, gid_t *gid) { + int r; + const char *name; + + assert(c); + + if (!c->group) + return 0; + + name = c->group; + r = get_group_creds(&name, gid, 0); + if (r < 0) + return r; + + *group = name; + return 0; +} + +static int get_supplementary_groups(const ExecContext *c, const char *user, + const char *group, gid_t gid, + gid_t **supplementary_gids, int *ngids) { + int r, k = 0; + int ngroups_max; + bool keep_groups = false; + gid_t *groups = NULL; + _cleanup_free_ gid_t *l_gids = NULL; + + assert(c); + + /* + * If user is given, then lookup GID and supplementary groups list. + * We avoid NSS lookups for gid=0. Also we have to initialize groups + * here and as early as possible so we keep the list of supplementary + * groups of the caller. + */ + if (user && gid_is_valid(gid) && gid != 0) { + /* First step, initialize groups from /etc/groups */ + if (initgroups(user, gid) < 0) + return -errno; + + keep_groups = true; + } + + if (strv_isempty(c->supplementary_groups)) + return 0; + + /* + * If SupplementaryGroups= was passed then NGROUPS_MAX has to + * be positive, otherwise fail. + */ + errno = 0; + ngroups_max = (int) sysconf(_SC_NGROUPS_MAX); + if (ngroups_max <= 0) + return errno_or_else(EOPNOTSUPP); + + l_gids = new(gid_t, ngroups_max); + if (!l_gids) + return -ENOMEM; + + if (keep_groups) { + /* + * Lookup the list of groups that the user belongs to, we + * avoid NSS lookups here too for gid=0. + */ + k = ngroups_max; + if (getgrouplist(user, gid, l_gids, &k) < 0) + return -EINVAL; + } else + k = 0; + + STRV_FOREACH(i, c->supplementary_groups) { + const char *g; + + if (k >= ngroups_max) + return -E2BIG; + + g = *i; + r = get_group_creds(&g, l_gids+k, 0); + if (r < 0) + return r; + + k++; + } + + /* + * Sets ngids to zero to drop all supplementary groups, happens + * when we are under root and SupplementaryGroups= is empty. + */ + if (k == 0) { + *ngids = 0; + return 0; + } + + /* Otherwise get the final list of supplementary groups */ + groups = memdup(l_gids, sizeof(gid_t) * k); + if (!groups) + return -ENOMEM; + + *supplementary_gids = groups; + *ngids = k; + + groups = NULL; + + return 0; +} + +static int enforce_groups(gid_t gid, const gid_t *supplementary_gids, int ngids) { + int r; + + /* Handle SupplementaryGroups= if it is not empty */ + if (ngids > 0) { + r = maybe_setgroups(ngids, supplementary_gids); + if (r < 0) + return r; + } + + if (gid_is_valid(gid)) { + /* Then set our gids */ + if (setresgid(gid, gid, gid) < 0) + return -errno; + } + + return 0; +} + +static int set_securebits(int bits, int mask) { + int current, applied; + current = prctl(PR_GET_SECUREBITS); + if (current < 0) + return -errno; + /* Clear all securebits defined in mask and set bits */ + applied = (current & ~mask) | bits; + if (current == applied) + return 0; + if (prctl(PR_SET_SECUREBITS, applied) < 0) + return -errno; + return 1; +} + +static int enforce_user(const ExecContext *context, uid_t uid) { + assert(context); + int r; + + if (!uid_is_valid(uid)) + return 0; + + /* Sets (but doesn't look up) the uid and make sure we keep the + * capabilities while doing so. For setting secure bits the capability CAP_SETPCAP is + * required, so we also need keep-caps in this case. + */ + + if (context->capability_ambient_set != 0 || context->secure_bits != 0) { + + /* 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) { + /* Add KEEP_CAPS to the securebits */ + r = set_securebits(1<<SECURE_KEEP_CAPS, 0); + if (r < 0) + return r; + } + } + + /* Second 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; +} + +#if 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; +} + +#endif + +static int setup_pam( + const char *name, + const char *user, + uid_t uid, + gid_t gid, + const char *tty, + char ***env, /* updated on success */ + const int fds[], size_t n_fds) { + +#if HAVE_PAM + + static const struct pam_conv conv = { + .conv = null_conv, + .appdata_ptr = NULL + }; + + _cleanup_(barrier_destroy) Barrier barrier = BARRIER_NULL; + _cleanup_strv_free_ char **e = NULL; + pam_handle_t *handle = NULL; + sigset_t old_ss; + int pam_code = PAM_SUCCESS, r; + bool close_session = false; + pid_t pam_pid = 0, parent_pid; + int flags = 0; + + assert(name); + assert(user); + assert(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. */ + + r = barrier_create(&barrier); + if (r < 0) + goto fail; + + if (log_get_max_level() < LOG_DEBUG) + flags |= PAM_SILENT; + + pam_code = pam_start(name, user, &conv, &handle); + if (pam_code != PAM_SUCCESS) { + handle = NULL; + goto fail; + } + + if (!tty) { + _cleanup_free_ char *q = NULL; + + /* Hmm, so no TTY was explicitly passed, but an fd passed to us directly might be a TTY. Let's figure + * out if that's the case, and read the TTY off it. */ + + if (getttyname_malloc(STDIN_FILENO, &q) >= 0) + tty = strjoina("/dev/", q); + } + + if (tty) { + pam_code = pam_set_item(handle, PAM_TTY, tty); + if (pam_code != PAM_SUCCESS) + goto fail; + } + + STRV_FOREACH(nv, *env) { + pam_code = pam_putenv(handle, *nv); + if (pam_code != PAM_SUCCESS) + goto fail; + } + + pam_code = pam_acct_mgmt(handle, flags); + if (pam_code != PAM_SUCCESS) + goto fail; + + pam_code = pam_setcred(handle, PAM_ESTABLISH_CRED | flags); + if (pam_code != PAM_SUCCESS) + log_debug("pam_setcred() failed, ignoring: %s", pam_strerror(handle, pam_code)); + + 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 */ + + assert_se(sigprocmask_many(SIG_BLOCK, &old_ss, SIGTERM, -1) >= 0); + + parent_pid = getpid_cached(); + + r = safe_fork("(sd-pam)", 0, &pam_pid); + if (r < 0) + goto fail; + if (r == 0) { + int sig, ret = EXIT_PAM; + + /* The child's job is to reset the PAM session on termination */ + barrier_set_role(&barrier, BARRIER_CHILD); + + /* 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. */ + (void) 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 */ + + r = maybe_setgroups(0, NULL); + if (r < 0) + log_warning_errno(r, "Failed to setgroups() in sd-pam: %m"); + if (setresgid(gid, gid, gid) < 0) + log_warning_errno(errno, "Failed to setresgid() in sd-pam: %m"); + if (setresuid(uid, uid, uid) < 0) + log_warning_errno(errno, "Failed to setresuid() in sd-pam: %m"); + + (void) ignore_signals(SIGPIPE); + + /* 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; + + /* Tell the parent that our setup is done. This is especially important regarding dropping + * privileges. Otherwise, unit setup might race against our setresuid(2) call. + * + * If the parent aborted, we'll detect this below, hence ignore return failure here. */ + (void) barrier_place(&barrier); + + /* Check if our parent process might already have died? */ + if (getppid() == parent_pid) { + sigset_t ss; + + assert_se(sigemptyset(&ss) >= 0); + assert_se(sigaddset(&ss, SIGTERM) >= 0); + + for (;;) { + if (sigwait(&ss, &sig) < 0) { + if (errno == EINTR) + continue; + + goto child_finish; + } + + assert(sig == SIGTERM); + break; + } + } + + pam_code = pam_setcred(handle, PAM_DELETE_CRED | flags); + if (pam_code != PAM_SUCCESS) + goto child_finish; + + /* 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; + } + + ret = 0; + + child_finish: + /* NB: pam_end() when called in child processes should set PAM_DATA_SILENT to let the module + * know about this. See pam_end(3) */ + (void) pam_end(handle, pam_code | flags | PAM_DATA_SILENT); + _exit(ret); + } + + barrier_set_role(&barrier, BARRIER_PARENT); + + /* 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 */ + assert_se(sigprocmask(SIG_SETMASK, &old_ss, NULL) >= 0); + + /* We close the log explicitly here, since the PAM modules might have opened it, but we don't want + * this fd around. */ + closelog(); + + /* Synchronously wait for the child to initialize. We don't care for errors as we cannot + * recover. However, warn loudly if it happens. */ + if (!barrier_place_and_sync(&barrier)) + log_error("PAM initialization failed"); + + return strv_free_and_replace(*env, e); + +fail: + if (pam_code != PAM_SUCCESS) { + log_error("PAM failed: %s", pam_strerror(handle, pam_code)); + r = -EPERM; /* PAM errors do not map to errno */ + } else + log_error_errno(r, "PAM failed: %m"); + + if (handle) { + if (close_session) + pam_code = pam_close_session(handle, flags); + + (void) pam_end(handle, pam_code | flags); + } + + closelog(); + return r; +#else + return 0; +#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 bool context_has_address_families(const ExecContext *c) { + assert(c); + + return c->address_families_allow_list || + !set_isempty(c->address_families); +} + +static bool context_has_syscall_filters(const ExecContext *c) { + assert(c); + + return c->syscall_allow_list || + !hashmap_isempty(c->syscall_filter); +} + +static bool context_has_syscall_logs(const ExecContext *c) { + assert(c); + + return c->syscall_log_allow_list || + !hashmap_isempty(c->syscall_log); +} + +static bool context_has_no_new_privileges(const ExecContext *c) { + assert(c); + + if (c->no_new_privileges) + return true; + + if (have_effective_cap(CAP_SYS_ADMIN)) /* if we are privileged, we don't need NNP */ + return false; + + /* We need NNP if we have any form of seccomp and are unprivileged */ + return c->lock_personality || + c->memory_deny_write_execute || + c->private_devices || + c->protect_clock || + c->protect_hostname || + c->protect_kernel_tunables || + c->protect_kernel_modules || + c->protect_kernel_logs || + context_has_address_families(c) || + exec_context_restrict_namespaces_set(c) || + c->restrict_realtime || + c->restrict_suid_sgid || + !set_isempty(c->syscall_archs) || + context_has_syscall_filters(c) || + context_has_syscall_logs(c); +} + +static bool exec_context_has_credentials(const ExecContext *context) { + + assert(context); + + return !hashmap_isempty(context->set_credentials) || + !hashmap_isempty(context->load_credentials); +} + +#if HAVE_SECCOMP + +static bool skip_seccomp_unavailable(const Unit* u, const char* msg) { + + if (is_seccomp_available()) + return false; + + log_unit_debug(u, "SECCOMP features not detected in the kernel, skipping %s", msg); + return true; +} + +static int apply_syscall_filter(const Unit* u, const ExecContext *c, bool needs_ambient_hack) { + uint32_t negative_action, default_action, action; + int r; + + assert(u); + assert(c); + + if (!context_has_syscall_filters(c)) + return 0; + + if (skip_seccomp_unavailable(u, "SystemCallFilter=")) + return 0; + + negative_action = c->syscall_errno == SECCOMP_ERROR_NUMBER_KILL ? scmp_act_kill_process() : SCMP_ACT_ERRNO(c->syscall_errno); + + if (c->syscall_allow_list) { + default_action = negative_action; + action = SCMP_ACT_ALLOW; + } else { + default_action = SCMP_ACT_ALLOW; + action = negative_action; + } + + if (needs_ambient_hack) { + r = seccomp_filter_set_add(c->syscall_filter, c->syscall_allow_list, syscall_filter_sets + SYSCALL_FILTER_SET_SETUID); + if (r < 0) + return r; + } + + return seccomp_load_syscall_filter_set_raw(default_action, c->syscall_filter, action, false); +} + +static int apply_syscall_log(const Unit* u, const ExecContext *c) { +#ifdef SCMP_ACT_LOG + uint32_t default_action, action; +#endif + + assert(u); + assert(c); + + if (!context_has_syscall_logs(c)) + return 0; + +#ifdef SCMP_ACT_LOG + if (skip_seccomp_unavailable(u, "SystemCallLog=")) + return 0; + + if (c->syscall_log_allow_list) { + /* Log nothing but the ones listed */ + default_action = SCMP_ACT_ALLOW; + action = SCMP_ACT_LOG; + } else { + /* Log everything but the ones listed */ + default_action = SCMP_ACT_LOG; + action = SCMP_ACT_ALLOW; + } + + return seccomp_load_syscall_filter_set_raw(default_action, c->syscall_log, action, false); +#else + /* old libseccomp */ + log_unit_debug(u, "SECCOMP feature SCMP_ACT_LOG not available, skipping SystemCallLog="); + return 0; +#endif +} + +static int apply_syscall_archs(const Unit *u, const ExecContext *c) { + assert(u); + assert(c); + + if (set_isempty(c->syscall_archs)) + return 0; + + if (skip_seccomp_unavailable(u, "SystemCallArchitectures=")) + return 0; + + return seccomp_restrict_archs(c->syscall_archs); +} + +static int apply_address_families(const Unit* u, const ExecContext *c) { + assert(u); + assert(c); + + if (!context_has_address_families(c)) + return 0; + + if (skip_seccomp_unavailable(u, "RestrictAddressFamilies=")) + return 0; + + return seccomp_restrict_address_families(c->address_families, c->address_families_allow_list); +} + +static int apply_memory_deny_write_execute(const Unit* u, const ExecContext *c) { + assert(u); + assert(c); + + if (!c->memory_deny_write_execute) + return 0; + + if (skip_seccomp_unavailable(u, "MemoryDenyWriteExecute=")) + return 0; + + return seccomp_memory_deny_write_execute(); +} + +static int apply_restrict_realtime(const Unit* u, const ExecContext *c) { + assert(u); + assert(c); + + if (!c->restrict_realtime) + return 0; + + if (skip_seccomp_unavailable(u, "RestrictRealtime=")) + return 0; + + return seccomp_restrict_realtime(); +} + +static int apply_restrict_suid_sgid(const Unit* u, const ExecContext *c) { + assert(u); + assert(c); + + if (!c->restrict_suid_sgid) + return 0; + + if (skip_seccomp_unavailable(u, "RestrictSUIDSGID=")) + return 0; + + return seccomp_restrict_suid_sgid(); +} + +static int apply_protect_sysctl(const Unit *u, const ExecContext *c) { + assert(u); + assert(c); + + /* Turn off the legacy sysctl() system call. Many distributions turn this off while building the kernel, but + * let's protect even those systems where this is left on in the kernel. */ + + if (!c->protect_kernel_tunables) + return 0; + + if (skip_seccomp_unavailable(u, "ProtectKernelTunables=")) + return 0; + + return seccomp_protect_sysctl(); +} + +static int apply_protect_kernel_modules(const Unit *u, const ExecContext *c) { + assert(u); + assert(c); + + /* Turn off module syscalls on ProtectKernelModules=yes */ + + if (!c->protect_kernel_modules) + return 0; + + if (skip_seccomp_unavailable(u, "ProtectKernelModules=")) + return 0; + + return seccomp_load_syscall_filter_set(SCMP_ACT_ALLOW, syscall_filter_sets + SYSCALL_FILTER_SET_MODULE, SCMP_ACT_ERRNO(EPERM), false); +} + +static int apply_protect_kernel_logs(const Unit *u, const ExecContext *c) { + assert(u); + assert(c); + + if (!c->protect_kernel_logs) + return 0; + + if (skip_seccomp_unavailable(u, "ProtectKernelLogs=")) + return 0; + + return seccomp_protect_syslog(); +} + +static int apply_protect_clock(const Unit *u, const ExecContext *c) { + assert(u); + assert(c); + + if (!c->protect_clock) + return 0; + + if (skip_seccomp_unavailable(u, "ProtectClock=")) + return 0; + + return seccomp_load_syscall_filter_set(SCMP_ACT_ALLOW, syscall_filter_sets + SYSCALL_FILTER_SET_CLOCK, SCMP_ACT_ERRNO(EPERM), false); +} + +static int apply_private_devices(const Unit *u, const ExecContext *c) { + assert(u); + assert(c); + + /* If PrivateDevices= is set, also turn off iopl and all @raw-io syscalls. */ + + if (!c->private_devices) + return 0; + + if (skip_seccomp_unavailable(u, "PrivateDevices=")) + return 0; + + return seccomp_load_syscall_filter_set(SCMP_ACT_ALLOW, syscall_filter_sets + SYSCALL_FILTER_SET_RAW_IO, SCMP_ACT_ERRNO(EPERM), false); +} + +static int apply_restrict_namespaces(const Unit *u, const ExecContext *c) { + assert(u); + assert(c); + + if (!exec_context_restrict_namespaces_set(c)) + return 0; + + if (skip_seccomp_unavailable(u, "RestrictNamespaces=")) + return 0; + + return seccomp_restrict_namespaces(c->restrict_namespaces); +} + +static int apply_lock_personality(const Unit* u, const ExecContext *c) { + unsigned long personality; + int r; + + assert(u); + assert(c); + + if (!c->lock_personality) + return 0; + + if (skip_seccomp_unavailable(u, "LockPersonality=")) + return 0; + + personality = c->personality; + + /* If personality is not specified, use either PER_LINUX or PER_LINUX32 depending on what is currently set. */ + if (personality == PERSONALITY_INVALID) { + + r = opinionated_personality(&personality); + if (r < 0) + return r; + } + + return seccomp_lock_personality(personality); +} + +#endif + +#if HAVE_LIBBPF +static int apply_restrict_filesystems(Unit *u, const ExecContext *c) { + assert(u); + assert(c); + + if (!exec_context_restrict_filesystems_set(c)) + return 0; + + if (!u->manager->restrict_fs) { + /* LSM BPF is unsupported or lsm_bpf_setup failed */ + log_unit_debug(u, "LSM BPF not supported, skipping RestrictFileSystems="); + return 0; + } + + return lsm_bpf_unit_restrict_filesystems(u, c->restrict_filesystems, c->restrict_filesystems_allow_list); +} +#endif + +static int apply_protect_hostname(const Unit *u, const ExecContext *c, int *ret_exit_status) { + assert(u); + assert(c); + + if (!c->protect_hostname) + return 0; + + if (ns_type_supported(NAMESPACE_UTS)) { + if (unshare(CLONE_NEWUTS) < 0) { + if (!ERRNO_IS_NOT_SUPPORTED(errno) && !ERRNO_IS_PRIVILEGE(errno)) { + *ret_exit_status = EXIT_NAMESPACE; + return log_unit_error_errno(u, errno, "Failed to set up UTS namespacing: %m"); + } + + log_unit_warning(u, "ProtectHostname=yes is configured, but UTS namespace setup is prohibited (container manager?), ignoring namespace setup."); + } + } else + log_unit_warning(u, "ProtectHostname=yes is configured, but the kernel does not support UTS namespaces, ignoring namespace setup."); + +#if HAVE_SECCOMP + int r; + + if (skip_seccomp_unavailable(u, "ProtectHostname=")) + return 0; + + r = seccomp_protect_hostname(); + if (r < 0) { + *ret_exit_status = EXIT_SECCOMP; + return log_unit_error_errno(u, r, "Failed to apply hostname restrictions: %m"); + } +#endif + + return 0; +} + +static void do_idle_pipe_dance(int idle_pipe[static 4]) { + assert(idle_pipe); + + idle_pipe[1] = safe_close(idle_pipe[1]); + idle_pipe[2] = safe_close(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 */) { + ssize_t n; + + /* Signal systemd that we are bored and want to continue. */ + n = write(idle_pipe[3], "x", 1); + if (n > 0) + /* Wait for systemd to react to the signal above. */ + (void) fd_wait_for_event(idle_pipe[0], POLLHUP, IDLE_TIMEOUT2_USEC); + } + + idle_pipe[0] = safe_close(idle_pipe[0]); + + } + + idle_pipe[3] = safe_close(idle_pipe[3]); +} + +static const char *exec_directory_env_name_to_string(ExecDirectoryType t); + +static int build_environment( + const Unit *u, + const ExecContext *c, + const ExecParameters *p, + size_t n_fds, + const char *home, + const char *username, + const char *shell, + dev_t journal_stream_dev, + ino_t journal_stream_ino, + char ***ret) { + + _cleanup_strv_free_ char **our_env = NULL; + size_t n_env = 0; + char *x; + + assert(u); + assert(c); + assert(p); + assert(ret); + +#define N_ENV_VARS 17 + our_env = new0(char*, N_ENV_VARS + _EXEC_DIRECTORY_TYPE_MAX); + if (!our_env) + return -ENOMEM; + + if (n_fds > 0) { + _cleanup_free_ char *joined = NULL; + + if (asprintf(&x, "LISTEN_PID="PID_FMT, getpid_cached()) < 0) + return -ENOMEM; + our_env[n_env++] = x; + + if (asprintf(&x, "LISTEN_FDS=%zu", n_fds) < 0) + return -ENOMEM; + our_env[n_env++] = x; + + joined = strv_join(p->fd_names, ":"); + if (!joined) + return -ENOMEM; + + x = strjoin("LISTEN_FDNAMES=", joined); + if (!x) + return -ENOMEM; + our_env[n_env++] = x; + } + + if ((p->flags & EXEC_SET_WATCHDOG) && p->watchdog_usec > 0) { + if (asprintf(&x, "WATCHDOG_PID="PID_FMT, getpid_cached()) < 0) + return -ENOMEM; + our_env[n_env++] = x; + + if (asprintf(&x, "WATCHDOG_USEC="USEC_FMT, p->watchdog_usec) < 0) + return -ENOMEM; + our_env[n_env++] = x; + } + + /* If this is D-Bus, tell the nss-systemd module, since it relies on being able to use blocking + * Varlink calls back to us for look up dynamic users in PID 1. Break the deadlock between D-Bus and + * PID 1 by disabling use of PID1' NSS interface for looking up dynamic users. */ + if (p->flags & EXEC_NSS_DYNAMIC_BYPASS) { + x = strdup("SYSTEMD_NSS_DYNAMIC_BYPASS=1"); + if (!x) + return -ENOMEM; + our_env[n_env++] = x; + } + + if (home) { + x = strjoin("HOME=", home); + if (!x) + return -ENOMEM; + + path_simplify(x + 5); + our_env[n_env++] = x; + } + + if (username) { + x = strjoin("LOGNAME=", username); + if (!x) + return -ENOMEM; + our_env[n_env++] = x; + + x = strjoin("USER=", username); + if (!x) + return -ENOMEM; + our_env[n_env++] = x; + } + + if (shell) { + x = strjoin("SHELL=", shell); + if (!x) + return -ENOMEM; + + path_simplify(x + 6); + our_env[n_env++] = x; + } + + if (!sd_id128_is_null(u->invocation_id)) { + if (asprintf(&x, "INVOCATION_ID=" SD_ID128_FORMAT_STR, SD_ID128_FORMAT_VAL(u->invocation_id)) < 0) + return -ENOMEM; + + our_env[n_env++] = x; + } + + if (exec_context_needs_term(c)) { + const char *tty_path, *term = NULL; + + tty_path = exec_context_tty_path(c); + + /* If we are forked off PID 1 and we are supposed to operate on /dev/console, then let's try + * to inherit the $TERM set for PID 1. This is useful for containers so that the $TERM the + * container manager passes to PID 1 ends up all the way in the console login shown. */ + + if (path_equal_ptr(tty_path, "/dev/console") && getppid() == 1) + term = getenv("TERM"); + + if (!term) + term = default_term_for_tty(tty_path); + + x = strjoin("TERM=", term); + if (!x) + return -ENOMEM; + our_env[n_env++] = x; + } + + if (journal_stream_dev != 0 && journal_stream_ino != 0) { + if (asprintf(&x, "JOURNAL_STREAM=" DEV_FMT ":" INO_FMT, journal_stream_dev, journal_stream_ino) < 0) + return -ENOMEM; + + our_env[n_env++] = x; + } + + if (c->log_namespace) { + x = strjoin("LOG_NAMESPACE=", c->log_namespace); + if (!x) + return -ENOMEM; + + our_env[n_env++] = x; + } + + for (ExecDirectoryType t = 0; t < _EXEC_DIRECTORY_TYPE_MAX; t++) { + _cleanup_free_ char *joined = NULL; + const char *n; + + if (!p->prefix[t]) + continue; + + if (c->directories[t].n_items == 0) + continue; + + n = exec_directory_env_name_to_string(t); + if (!n) + continue; + + for (size_t i = 0; i < c->directories[t].n_items; i++) { + _cleanup_free_ char *prefixed = NULL; + + prefixed = path_join(p->prefix[t], c->directories[t].items[i].path); + if (!prefixed) + return -ENOMEM; + + if (!strextend_with_separator(&joined, ":", prefixed)) + return -ENOMEM; + } + + x = strjoin(n, "=", joined); + if (!x) + return -ENOMEM; + + our_env[n_env++] = x; + } + + if (exec_context_has_credentials(c) && p->prefix[EXEC_DIRECTORY_RUNTIME]) { + x = strjoin("CREDENTIALS_DIRECTORY=", p->prefix[EXEC_DIRECTORY_RUNTIME], "/credentials/", u->id); + if (!x) + return -ENOMEM; + + our_env[n_env++] = x; + } + + if (asprintf(&x, "SYSTEMD_EXEC_PID=" PID_FMT, getpid_cached()) < 0) + return -ENOMEM; + + our_env[n_env++] = x; + + our_env[n_env++] = NULL; + assert(n_env <= N_ENV_VARS + _EXEC_DIRECTORY_TYPE_MAX); +#undef N_ENV_VARS + + *ret = TAKE_PTR(our_env); + + return 0; +} + +static int build_pass_environment(const ExecContext *c, char ***ret) { + _cleanup_strv_free_ char **pass_env = NULL; + size_t n_env = 0; + + STRV_FOREACH(i, c->pass_environment) { + _cleanup_free_ char *x = NULL; + char *v; + + v = getenv(*i); + if (!v) + continue; + x = strjoin(*i, "=", v); + if (!x) + return -ENOMEM; + + if (!GREEDY_REALLOC(pass_env, n_env + 2)) + return -ENOMEM; + + pass_env[n_env++] = TAKE_PTR(x); + pass_env[n_env] = NULL; + } + + *ret = TAKE_PTR(pass_env); + + return 0; +} + +bool exec_needs_mount_namespace( + const ExecContext *context, + const ExecParameters *params, + const ExecRuntime *runtime) { + + assert(context); + + if (context->root_image) + return true; + + if (!strv_isempty(context->read_write_paths) || + !strv_isempty(context->read_only_paths) || + !strv_isempty(context->inaccessible_paths) || + !strv_isempty(context->exec_paths) || + !strv_isempty(context->no_exec_paths)) + return true; + + if (context->n_bind_mounts > 0) + return true; + + if (context->n_temporary_filesystems > 0) + return true; + + if (context->n_mount_images > 0) + return true; + + if (context->n_extension_images > 0) + return true; + + if (!strv_isempty(context->extension_directories)) + return true; + + if (!IN_SET(context->mount_flags, 0, MS_SHARED)) + return true; + + if (context->private_tmp && runtime && (runtime->tmp_dir || runtime->var_tmp_dir)) + return true; + + if (context->private_devices || + context->private_mounts || + context->protect_system != PROTECT_SYSTEM_NO || + context->protect_home != PROTECT_HOME_NO || + context->protect_kernel_tunables || + context->protect_kernel_modules || + context->protect_kernel_logs || + context->protect_control_groups || + context->protect_proc != PROTECT_PROC_DEFAULT || + context->proc_subset != PROC_SUBSET_ALL || + context->private_ipc || + context->ipc_namespace_path) + return true; + + if (context->root_directory) { + if (exec_context_get_effective_mount_apivfs(context)) + return true; + + for (ExecDirectoryType t = 0; t < _EXEC_DIRECTORY_TYPE_MAX; t++) { + if (params && !params->prefix[t]) + continue; + + if (context->directories[t].n_items > 0) + return true; + } + } + + if (context->dynamic_user && + (context->directories[EXEC_DIRECTORY_STATE].n_items > 0 || + context->directories[EXEC_DIRECTORY_CACHE].n_items > 0 || + context->directories[EXEC_DIRECTORY_LOGS].n_items > 0)) + return true; + + if (context->log_namespace) + return true; + + return false; +} + +static int setup_private_users(uid_t ouid, gid_t ogid, uid_t uid, gid_t gid) { + _cleanup_free_ char *uid_map = NULL, *gid_map = NULL; + _cleanup_close_pair_ int errno_pipe[2] = { -1, -1 }; + _cleanup_close_ int unshare_ready_fd = -1; + _cleanup_(sigkill_waitp) pid_t pid = 0; + uint64_t c = 1; + ssize_t n; + int r; + + /* Set up a user namespace and map the original UID/GID (IDs from before any user or group changes, i.e. + * the IDs from the user or system manager(s)) to itself, the selected UID/GID to itself, and everything else to + * nobody. In order to be able to write this mapping we need CAP_SETUID in the original user namespace, which + * we however lack after opening the user namespace. To work around this we fork() a temporary child process, + * which waits for the parent to create the new user namespace while staying in the original namespace. The + * child then writes the UID mapping, under full privileges. The parent waits for the child to finish and + * continues execution normally. + * For unprivileged users (i.e. without capabilities), the root to root mapping is excluded. As such, it + * does not need CAP_SETUID to write the single line mapping to itself. */ + + /* Can only set up multiple mappings with CAP_SETUID. */ + if (have_effective_cap(CAP_SETUID) && uid != ouid && uid_is_valid(uid)) + r = asprintf(&uid_map, + UID_FMT " " UID_FMT " 1\n" /* Map $OUID → $OUID */ + UID_FMT " " UID_FMT " 1\n", /* Map $UID → $UID */ + ouid, ouid, uid, uid); + else + r = asprintf(&uid_map, + UID_FMT " " UID_FMT " 1\n", /* Map $OUID → $OUID */ + ouid, ouid); + + if (r < 0) + return -ENOMEM; + + /* Can only set up multiple mappings with CAP_SETGID. */ + if (have_effective_cap(CAP_SETGID) && gid != ogid && gid_is_valid(gid)) + r = asprintf(&gid_map, + GID_FMT " " GID_FMT " 1\n" /* Map $OGID → $OGID */ + GID_FMT " " GID_FMT " 1\n", /* Map $GID → $GID */ + ogid, ogid, gid, gid); + else + r = asprintf(&gid_map, + GID_FMT " " GID_FMT " 1\n", /* Map $OGID -> $OGID */ + ogid, ogid); + + if (r < 0) + return -ENOMEM; + + /* Create a communication channel so that the parent can tell the child when it finished creating the user + * namespace. */ + unshare_ready_fd = eventfd(0, EFD_CLOEXEC); + if (unshare_ready_fd < 0) + return -errno; + + /* Create a communication channel so that the child can tell the parent a proper error code in case it + * failed. */ + if (pipe2(errno_pipe, O_CLOEXEC) < 0) + return -errno; + + r = safe_fork("(sd-userns)", FORK_RESET_SIGNALS|FORK_DEATHSIG, &pid); + if (r < 0) + return r; + if (r == 0) { + _cleanup_close_ int fd = -1; + const char *a; + pid_t ppid; + + /* Child process, running in the original user namespace. Let's update the parent's UID/GID map from + * here, after the parent opened its own user namespace. */ + + ppid = getppid(); + errno_pipe[0] = safe_close(errno_pipe[0]); + + /* Wait until the parent unshared the user namespace */ + if (read(unshare_ready_fd, &c, sizeof(c)) < 0) { + r = -errno; + goto child_fail; + } + + /* Disable the setgroups() system call in the child user namespace, for good. */ + a = procfs_file_alloca(ppid, "setgroups"); + fd = open(a, O_WRONLY|O_CLOEXEC); + if (fd < 0) { + if (errno != ENOENT) { + r = -errno; + goto child_fail; + } + + /* If the file is missing the kernel is too old, let's continue anyway. */ + } else { + if (write(fd, "deny\n", 5) < 0) { + r = -errno; + goto child_fail; + } + + fd = safe_close(fd); + } + + /* First write the GID map */ + a = procfs_file_alloca(ppid, "gid_map"); + fd = open(a, O_WRONLY|O_CLOEXEC); + if (fd < 0) { + r = -errno; + goto child_fail; + } + if (write(fd, gid_map, strlen(gid_map)) < 0) { + r = -errno; + goto child_fail; + } + fd = safe_close(fd); + + /* The write the UID map */ + a = procfs_file_alloca(ppid, "uid_map"); + fd = open(a, O_WRONLY|O_CLOEXEC); + if (fd < 0) { + r = -errno; + goto child_fail; + } + if (write(fd, uid_map, strlen(uid_map)) < 0) { + r = -errno; + goto child_fail; + } + + _exit(EXIT_SUCCESS); + + child_fail: + (void) write(errno_pipe[1], &r, sizeof(r)); + _exit(EXIT_FAILURE); + } + + errno_pipe[1] = safe_close(errno_pipe[1]); + + if (unshare(CLONE_NEWUSER) < 0) + return -errno; + + /* Let the child know that the namespace is ready now */ + if (write(unshare_ready_fd, &c, sizeof(c)) < 0) + return -errno; + + /* Try to read an error code from the child */ + n = read(errno_pipe[0], &r, sizeof(r)); + if (n < 0) + return -errno; + if (n == sizeof(r)) { /* an error code was sent to us */ + if (r < 0) + return r; + return -EIO; + } + if (n != 0) /* on success we should have read 0 bytes */ + return -EIO; + + r = wait_for_terminate_and_check("(sd-userns)", TAKE_PID(pid), 0); + if (r < 0) + return r; + if (r != EXIT_SUCCESS) /* If something strange happened with the child, let's consider this fatal, too */ + return -EIO; + + return 0; +} + +static bool exec_directory_is_private(const ExecContext *context, ExecDirectoryType type) { + if (!context->dynamic_user) + return false; + + if (type == EXEC_DIRECTORY_CONFIGURATION) + return false; + + if (type == EXEC_DIRECTORY_RUNTIME && context->runtime_directory_preserve_mode == EXEC_PRESERVE_NO) + return false; + + return true; +} + +static int create_many_symlinks(const char *root, const char *source, char **symlinks) { + _cleanup_free_ char *src_abs = NULL; + int r; + + assert(source); + + src_abs = path_join(root, source); + if (!src_abs) + return -ENOMEM; + + STRV_FOREACH(dst, symlinks) { + _cleanup_free_ char *dst_abs = NULL; + + dst_abs = path_join(root, *dst); + if (!dst_abs) + return -ENOMEM; + + r = mkdir_parents_label(dst_abs, 0755); + if (r < 0) + return r; + + r = symlink_idempotent(src_abs, dst_abs, true); + if (r < 0) + return r; + } + + return 0; +} + +static int setup_exec_directory( + const ExecContext *context, + const ExecParameters *params, + uid_t uid, + gid_t gid, + ExecDirectoryType type, + bool needs_mount_namespace, + int *exit_status) { + + static const int exit_status_table[_EXEC_DIRECTORY_TYPE_MAX] = { + [EXEC_DIRECTORY_RUNTIME] = EXIT_RUNTIME_DIRECTORY, + [EXEC_DIRECTORY_STATE] = EXIT_STATE_DIRECTORY, + [EXEC_DIRECTORY_CACHE] = EXIT_CACHE_DIRECTORY, + [EXEC_DIRECTORY_LOGS] = EXIT_LOGS_DIRECTORY, + [EXEC_DIRECTORY_CONFIGURATION] = EXIT_CONFIGURATION_DIRECTORY, + }; + int r; + + assert(context); + assert(params); + assert(type >= 0 && type < _EXEC_DIRECTORY_TYPE_MAX); + assert(exit_status); + + if (!params->prefix[type]) + return 0; + + if (params->flags & EXEC_CHOWN_DIRECTORIES) { + if (!uid_is_valid(uid)) + uid = 0; + if (!gid_is_valid(gid)) + gid = 0; + } + + for (size_t i = 0; i < context->directories[type].n_items; i++) { + _cleanup_free_ char *p = NULL, *pp = NULL; + + p = path_join(params->prefix[type], context->directories[type].items[i].path); + if (!p) { + r = -ENOMEM; + goto fail; + } + + r = mkdir_parents_label(p, 0755); + if (r < 0) + goto fail; + + if (exec_directory_is_private(context, type)) { + /* So, here's one extra complication when dealing with DynamicUser=1 units. In that + * case we want to avoid leaving a directory around fully accessible that is owned by + * a dynamic user whose UID is later on reused. To lock this down we use the same + * trick used by container managers to prohibit host users to get access to files of + * the same UID in containers: we place everything inside a directory that has an + * access mode of 0700 and is owned root:root, so that it acts as security boundary + * for unprivileged host code. We then use fs namespacing to make this directory + * permeable for the service itself. + * + * Specifically: for a service which wants a special directory "foo/" we first create + * a directory "private/" with access mode 0700 owned by root:root. Then we place + * "foo" inside of that directory (i.e. "private/foo/"), and make "foo" a symlink to + * "private/foo". This way, privileged host users can access "foo/" as usual, but + * unprivileged host users can't look into it. Inside of the namespace of the unit + * "private/" is replaced by a more liberally accessible tmpfs, into which the host's + * "private/foo/" is mounted under the same name, thus disabling the access boundary + * for the service and making sure it only gets access to the dirs it needs but no + * others. Tricky? Yes, absolutely, but it works! + * + * Note that we don't do this for EXEC_DIRECTORY_CONFIGURATION as that's assumed not + * to be owned by the service itself. + * + * Also, note that we don't do this for EXEC_DIRECTORY_RUNTIME as that's often used + * for sharing files or sockets with other services. */ + + pp = path_join(params->prefix[type], "private"); + if (!pp) { + r = -ENOMEM; + goto fail; + } + + /* First set up private root if it doesn't exist yet, with access mode 0700 and owned by root:root */ + r = mkdir_safe_label(pp, 0700, 0, 0, MKDIR_WARN_MODE); + if (r < 0) + goto fail; + + if (!path_extend(&pp, context->directories[type].items[i].path)) { + r = -ENOMEM; + goto fail; + } + + /* Create all directories between the configured directory and this private root, and mark them 0755 */ + r = mkdir_parents_label(pp, 0755); + if (r < 0) + goto fail; + + if (is_dir(p, false) > 0 && + (laccess(pp, F_OK) < 0 && errno == ENOENT)) { + + /* Hmm, the private directory doesn't exist yet, but the normal one exists? If so, move + * it over. Most likely the service has been upgraded from one that didn't use + * DynamicUser=1, to one that does. */ + + log_info("Found pre-existing public %s= directory %s, migrating to %s.\n" + "Apparently, service previously had DynamicUser= turned off, and has now turned it on.", + exec_directory_type_to_string(type), p, pp); + + if (rename(p, pp) < 0) { + r = -errno; + goto fail; + } + } else { + /* Otherwise, create the actual directory for the service */ + + r = mkdir_label(pp, context->directories[type].mode); + if (r < 0 && r != -EEXIST) + goto fail; + } + + if (!context->directories[type].items[i].only_create) { + /* And link it up from the original place. + * Notes + * 1) If a mount namespace is going to be used, then this symlink remains on + * the host, and a new one for the child namespace will be created later. + * 2) It is not necessary to create this symlink when one of its parent + * directories is specified and already created. E.g. + * StateDirectory=foo foo/bar + * In that case, the inode points to pp and p for "foo/bar" are the same: + * pp = "/var/lib/private/foo/bar" + * p = "/var/lib/foo/bar" + * and, /var/lib/foo is a symlink to /var/lib/private/foo. So, not only + * we do not need to create the symlink, but we cannot create the symlink. + * See issue #24783. */ + r = symlink_idempotent(pp, p, true); + if (r < 0) + goto fail; + } + + } else { + _cleanup_free_ char *target = NULL; + + if (type != EXEC_DIRECTORY_CONFIGURATION && + readlink_and_make_absolute(p, &target) >= 0) { + _cleanup_free_ char *q = NULL, *q_resolved = NULL, *target_resolved = NULL; + + /* This already exists and is a symlink? Interesting. Maybe it's one created + * by DynamicUser=1 (see above)? + * + * We do this for all directory types except for ConfigurationDirectory=, + * since they all support the private/ symlink logic at least in some + * configurations, see above. */ + + r = chase_symlinks(target, NULL, 0, &target_resolved, NULL); + if (r < 0) + goto fail; + + q = path_join(params->prefix[type], "private", context->directories[type].items[i].path); + if (!q) { + r = -ENOMEM; + goto fail; + } + + /* /var/lib or friends may be symlinks. So, let's chase them also. */ + r = chase_symlinks(q, NULL, CHASE_NONEXISTENT, &q_resolved, NULL); + if (r < 0) + goto fail; + + if (path_equal(q_resolved, target_resolved)) { + + /* Hmm, apparently DynamicUser= was once turned on for this service, + * but is no longer. Let's move the directory back up. */ + + log_info("Found pre-existing private %s= directory %s, migrating to %s.\n" + "Apparently, service previously had DynamicUser= turned on, and has now turned it off.", + exec_directory_type_to_string(type), q, p); + + if (unlink(p) < 0) { + r = -errno; + goto fail; + } + + if (rename(q, p) < 0) { + r = -errno; + goto fail; + } + } + } + + r = mkdir_label(p, context->directories[type].mode); + if (r < 0) { + if (r != -EEXIST) + goto fail; + + if (type == EXEC_DIRECTORY_CONFIGURATION) { + struct stat st; + + /* Don't change the owner/access mode of the configuration directory, + * as in the common case it is not written to by a service, and shall + * not be writable. */ + + if (stat(p, &st) < 0) { + r = -errno; + goto fail; + } + + /* Still complain if the access mode doesn't match */ + if (((st.st_mode ^ context->directories[type].mode) & 07777) != 0) + log_warning("%s \'%s\' already exists but the mode is different. " + "(File system: %o %sMode: %o)", + exec_directory_type_to_string(type), context->directories[type].items[i].path, + st.st_mode & 07777, exec_directory_type_to_string(type), context->directories[type].mode & 07777); + + continue; + } + } + } + + /* Lock down the access mode (we use chmod_and_chown() to make this idempotent. We don't + * specify UID/GID here, so that path_chown_recursive() can optimize things depending on the + * current UID/GID ownership.) */ + r = chmod_and_chown(pp ?: p, context->directories[type].mode, UID_INVALID, GID_INVALID); + if (r < 0) + goto fail; + + /* Then, change the ownership of the whole tree, if necessary. When dynamic users are used we + * drop the suid/sgid bits, since we really don't want SUID/SGID files for dynamic UID/GID + * assignments to exist. */ + r = path_chown_recursive(pp ?: p, uid, gid, context->dynamic_user ? 01777 : 07777); + if (r < 0) + goto fail; + } + + /* If we are not going to run in a namespace, set up the symlinks - otherwise + * they are set up later, to allow configuring empty var/run/etc. */ + if (!needs_mount_namespace) + for (size_t i = 0; i < context->directories[type].n_items; i++) { + r = create_many_symlinks(params->prefix[type], + context->directories[type].items[i].path, + context->directories[type].items[i].symlinks); + if (r < 0) + goto fail; + } + + return 0; + +fail: + *exit_status = exit_status_table[type]; + return r; +} + +static int write_credential( + int dfd, + const char *id, + const void *data, + size_t size, + uid_t uid, + bool ownership_ok) { + + _cleanup_(unlink_and_freep) char *tmp = NULL; + _cleanup_close_ int fd = -1; + int r; + + r = tempfn_random_child("", "cred", &tmp); + if (r < 0) + return r; + + fd = openat(dfd, tmp, O_CREAT|O_RDWR|O_CLOEXEC|O_EXCL|O_NOFOLLOW|O_NOCTTY, 0600); + if (fd < 0) { + tmp = mfree(tmp); + return -errno; + } + + r = loop_write(fd, data, size, /* do_poll = */ false); + if (r < 0) + return r; + + if (fchmod(fd, 0400) < 0) /* Take away "w" bit */ + return -errno; + + if (uid_is_valid(uid) && uid != getuid()) { + r = fd_add_uid_acl_permission(fd, uid, ACL_READ); + if (r < 0) { + if (!ERRNO_IS_NOT_SUPPORTED(r) && !ERRNO_IS_PRIVILEGE(r)) + return r; + + if (!ownership_ok) /* Ideally we use ACLs, since we can neatly express what we want + * to express: that the user gets read access and nothing + * else. But if the backing fs can't support that (e.g. ramfs) + * then we can use file ownership instead. But that's only safe if + * we can then re-mount the whole thing read-only, so that the + * user can no longer chmod() the file to gain write access. */ + return r; + + if (fchown(fd, uid, GID_INVALID) < 0) + return -errno; + } + } + + if (renameat(dfd, tmp, dfd, id) < 0) + return -errno; + + tmp = mfree(tmp); + return 0; +} + +static char **credential_search_path( + const ExecParameters *params, + bool encrypted) { + + _cleanup_strv_free_ char **l = NULL; + + assert(params); + + /* Assemble a search path to find credentials in. We'll look in /etc/credstore/ (and similar + * directories in /usr/lib/ + /run/) for all types of credentials. If we are looking for encrypted + * credentials, also look in /etc/credstore.encrypted/ (and similar dirs). */ + + if (encrypted) { + if (strv_extend(&l, params->received_encrypted_credentials_directory) < 0) + return NULL; + + if (strv_extend_strv(&l, CONF_PATHS_STRV("credstore.encrypted"), /* filter_duplicates= */ true) < 0) + return NULL; + } + + if (params->received_credentials_directory) + if (strv_extend(&l, params->received_credentials_directory) < 0) + return NULL; + + if (strv_extend_strv(&l, CONF_PATHS_STRV("credstore"), /* filter_duplicates= */ true) < 0) + return NULL; + + if (DEBUG_LOGGING) { + _cleanup_free_ char *t = strv_join(l, ":"); + + log_debug("Credential search path is: %s", strempty(t)); + } + + return TAKE_PTR(l); +} + +static int load_credential( + const ExecContext *context, + const ExecParameters *params, + const char *id, + const char *path, + bool encrypted, + const char *unit, + int read_dfd, + int write_dfd, + uid_t uid, + bool ownership_ok, + uint64_t *left) { + + ReadFullFileFlags flags = READ_FULL_FILE_SECURE|READ_FULL_FILE_FAIL_WHEN_LARGER; + _cleanup_strv_free_ char **search_path = NULL; + _cleanup_(erase_and_freep) char *data = NULL; + _cleanup_free_ char *bindname = NULL; + const char *source = NULL; + bool missing_ok = true; + size_t size, add, maxsz; + int r; + + assert(context); + assert(params); + assert(id); + assert(path); + assert(unit); + assert(read_dfd >= 0 || read_dfd == AT_FDCWD); + assert(write_dfd >= 0); + assert(left); + + if (read_dfd >= 0) { + /* If a directory fd is specified, then read the file directly from that dir. In this case we + * won't do AF_UNIX stuff (we simply don't want to recursively iterate down a tree of AF_UNIX + * IPC sockets). It's OK if a file vanishes here in the time we enumerate it and intend to + * open it. */ + + if (!filename_is_valid(path)) /* safety check */ + return -EINVAL; + + missing_ok = true; + source = path; + + } else if (path_is_absolute(path)) { + /* If this is an absolute path, read the data directly from it, and support AF_UNIX + * sockets */ + + if (!path_is_valid(path)) /* safety check */ + return -EINVAL; + + flags |= READ_FULL_FILE_CONNECT_SOCKET; + + /* Pass some minimal info about the unit and the credential name we are looking to acquire + * via the source socket address in case we read off an AF_UNIX socket. */ + if (asprintf(&bindname, "@%" PRIx64"/unit/%s/%s", random_u64(), unit, id) < 0) + return -ENOMEM; + + missing_ok = false; + source = path; + + } else if (credential_name_valid(path)) { + /* If this is a relative path, take it as credential name relative to the credentials + * directory we received ourselves. We don't support the AF_UNIX stuff in this mode, since we + * are operating on a credential store, i.e. this is guaranteed to be regular files. */ + + search_path = credential_search_path(params, encrypted); + if (!search_path) + return -ENOMEM; + + missing_ok = true; + } else + source = NULL; + + if (encrypted) + flags |= READ_FULL_FILE_UNBASE64; + + maxsz = encrypted ? CREDENTIAL_ENCRYPTED_SIZE_MAX : CREDENTIAL_SIZE_MAX; + + if (search_path) { + STRV_FOREACH(d, search_path) { + _cleanup_free_ char *j = NULL; + + j = path_join(*d, path); + if (!j) + return -ENOMEM; + + r = read_full_file_full( + AT_FDCWD, j, /* path is absolute, hence pass AT_FDCWD as nop dir fd here */ + UINT64_MAX, + maxsz, + flags, + NULL, + &data, &size); + if (r != -ENOENT) + break; + } + } else if (source) + r = read_full_file_full( + read_dfd, source, + UINT64_MAX, + maxsz, + flags, + bindname, + &data, &size); + else + r = -ENOENT; + + if (r == -ENOENT && (missing_ok || hashmap_contains(context->set_credentials, id))) { + /* Make a missing inherited credential non-fatal, let's just continue. After all apps + * will get clear errors if we don't pass such a missing credential on as they + * themselves will get ENOENT when trying to read them, which should not be much + * worse than when we handle the error here and make it fatal. + * + * Also, if the source file doesn't exist, but a fallback is set via SetCredentials= + * we are fine, too. */ + log_debug_errno(r, "Couldn't read inherited credential '%s', skipping: %m", path); + return 0; + } + if (r < 0) + return log_debug_errno(r, "Failed to read credential '%s': %m", path); + + if (encrypted) { + _cleanup_free_ void *plaintext = NULL; + size_t plaintext_size = 0; + + r = decrypt_credential_and_warn(id, now(CLOCK_REALTIME), NULL, NULL, data, size, &plaintext, &plaintext_size); + if (r < 0) + return r; + + free_and_replace(data, plaintext); + size = plaintext_size; + } + + add = strlen(id) + size; + if (add > *left) + return -E2BIG; + + r = write_credential(write_dfd, id, data, size, uid, ownership_ok); + if (r < 0) + return log_debug_errno(r, "Failed to write credential '%s': %m", id); + + *left -= add; + return 0; +} + +struct load_cred_args { + const ExecContext *context; + const ExecParameters *params; + bool encrypted; + const char *unit; + int dfd; + uid_t uid; + bool ownership_ok; + uint64_t *left; +}; + +static int load_cred_recurse_dir_cb( + RecurseDirEvent event, + const char *path, + int dir_fd, + int inode_fd, + const struct dirent *de, + const struct statx *sx, + void *userdata) { + + struct load_cred_args *args = ASSERT_PTR(userdata); + _cleanup_free_ char *sub_id = NULL; + int r; + + if (event != RECURSE_DIR_ENTRY) + return RECURSE_DIR_CONTINUE; + + if (!IN_SET(de->d_type, DT_REG, DT_SOCK)) + return RECURSE_DIR_CONTINUE; + + sub_id = strreplace(path, "/", "_"); + if (!sub_id) + return -ENOMEM; + + if (!credential_name_valid(sub_id)) + return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Credential would get ID %s, which is not valid, refusing", sub_id); + + if (faccessat(args->dfd, sub_id, F_OK, AT_SYMLINK_NOFOLLOW) >= 0) { + log_debug("Skipping credential with duplicated ID %s at %s", sub_id, path); + return RECURSE_DIR_CONTINUE; + } + if (errno != ENOENT) + return log_debug_errno(errno, "Failed to test if credential %s exists: %m", sub_id); + + r = load_credential( + args->context, + args->params, + sub_id, + de->d_name, + args->encrypted, + args->unit, + dir_fd, + args->dfd, + args->uid, + args->ownership_ok, + args->left); + if (r < 0) + return r; + + return RECURSE_DIR_CONTINUE; +} + +static int acquire_credentials( + const ExecContext *context, + const ExecParameters *params, + const char *unit, + const char *p, + uid_t uid, + bool ownership_ok) { + + uint64_t left = CREDENTIALS_TOTAL_SIZE_MAX; + _cleanup_close_ int dfd = -1; + ExecLoadCredential *lc; + ExecSetCredential *sc; + int r; + + assert(context); + assert(p); + + dfd = open(p, O_DIRECTORY|O_CLOEXEC); + if (dfd < 0) + return -errno; + + r = fd_acl_make_writable(dfd); /* Add the "w" bit, if we are reusing an already set up credentials dir where it was unset */ + if (r < 0) + return r; + + /* First, load credentials off disk (or acquire via AF_UNIX socket) */ + HASHMAP_FOREACH(lc, context->load_credentials) { + _cleanup_close_ int sub_fd = -1; + + /* If this is an absolute path, then try to open it as a directory. If that works, then we'll + * recurse into it. If it is an absolute path but it isn't a directory, then we'll open it as + * a regular file. Finally, if it's a relative path we will use it as a credential name to + * propagate a credential passed to us from further up. */ + + if (path_is_absolute(lc->path)) { + sub_fd = open(lc->path, O_DIRECTORY|O_CLOEXEC|O_RDONLY); + if (sub_fd < 0 && !IN_SET(errno, + ENOTDIR, /* Not a directory */ + ENOENT)) /* Doesn't exist? */ + return log_debug_errno(errno, "Failed to open '%s': %m", lc->path); + } + + if (sub_fd < 0) + /* Regular file (incl. a credential passed in from higher up) */ + r = load_credential( + context, + params, + lc->id, + lc->path, + lc->encrypted, + unit, + AT_FDCWD, + dfd, + uid, + ownership_ok, + &left); + else + /* Directory */ + r = recurse_dir( + sub_fd, + /* path= */ lc->id, /* recurse_dir() will suffix the subdir paths from here to the top-level id */ + /* statx_mask= */ 0, + /* n_depth_max= */ UINT_MAX, + RECURSE_DIR_SORT|RECURSE_DIR_IGNORE_DOT|RECURSE_DIR_ENSURE_TYPE, + load_cred_recurse_dir_cb, + &(struct load_cred_args) { + .context = context, + .params = params, + .encrypted = lc->encrypted, + .unit = unit, + .dfd = dfd, + .uid = uid, + .ownership_ok = ownership_ok, + .left = &left, + }); + if (r < 0) + return r; + } + + /* Second, we add in literally specified credentials. If the credentials already exist, we'll not add + * them, so that they can act as a "default" if the same credential is specified multiple times. */ + HASHMAP_FOREACH(sc, context->set_credentials) { + _cleanup_(erase_and_freep) void *plaintext = NULL; + const char *data; + size_t size, add; + + /* Note that we check ahead of time here instead of relying on O_EXCL|O_CREAT later to return + * EEXIST if the credential already exists. That's because the TPM2-based decryption is kinda + * slow and involved, hence it's nice to be able to skip that if the credential already + * exists anyway. */ + if (faccessat(dfd, sc->id, F_OK, AT_SYMLINK_NOFOLLOW) >= 0) + continue; + if (errno != ENOENT) + return log_debug_errno(errno, "Failed to test if credential %s exists: %m", sc->id); + + if (sc->encrypted) { + r = decrypt_credential_and_warn(sc->id, now(CLOCK_REALTIME), NULL, NULL, sc->data, sc->size, &plaintext, &size); + if (r < 0) + return r; + + data = plaintext; + } else { + data = sc->data; + size = sc->size; + } + + add = strlen(sc->id) + size; + if (add > left) + return -E2BIG; + + r = write_credential(dfd, sc->id, data, size, uid, ownership_ok); + if (r < 0) + return r; + + left -= add; + } + + r = fd_acl_make_read_only(dfd); /* Now take away the "w" bit */ + if (r < 0) + return r; + + /* After we created all keys with the right perms, also make sure the credential store as a whole is + * accessible */ + + if (uid_is_valid(uid) && uid != getuid()) { + r = fd_add_uid_acl_permission(dfd, uid, ACL_READ | ACL_EXECUTE); + if (r < 0) { + if (!ERRNO_IS_NOT_SUPPORTED(r) && !ERRNO_IS_PRIVILEGE(r)) + return r; + + if (!ownership_ok) + return r; + + if (fchown(dfd, uid, GID_INVALID) < 0) + return -errno; + } + } + + return 0; +} + +static int setup_credentials_internal( + const ExecContext *context, + const ExecParameters *params, + const char *unit, + const char *final, /* This is where the credential store shall eventually end up at */ + const char *workspace, /* This is where we can prepare it before moving it to the final place */ + bool reuse_workspace, /* Whether to reuse any existing workspace mount if it already is a mount */ + bool must_mount, /* Whether to require that we mount something, it's not OK to use the plain directory fall back */ + uid_t uid) { + + int r, workspace_mounted; /* negative if we don't know yet whether we have/can mount something; true + * if we mounted something; false if we definitely can't mount anything */ + bool final_mounted; + const char *where; + + assert(context); + assert(final); + assert(workspace); + + if (reuse_workspace) { + r = path_is_mount_point(workspace, NULL, 0); + if (r < 0) + return r; + if (r > 0) + workspace_mounted = true; /* If this is already a mount, and we are supposed to reuse it, let's keep this in mind */ + else + workspace_mounted = -1; /* We need to figure out if we can mount something to the workspace */ + } else + workspace_mounted = -1; /* ditto */ + + r = path_is_mount_point(final, NULL, 0); + if (r < 0) + return r; + if (r > 0) { + /* If the final place already has something mounted, we use that. If the workspace also has + * something mounted we assume it's actually the same mount (but with MS_RDONLY + * different). */ + final_mounted = true; + + if (workspace_mounted < 0) { + /* If the final place is mounted, but the workspace we isn't, then let's bind mount + * the final version to the workspace, and make it writable, so that we can make + * changes */ + + r = mount_nofollow_verbose(LOG_DEBUG, final, workspace, NULL, MS_BIND|MS_REC, NULL); + if (r < 0) + return r; + + r = mount_nofollow_verbose(LOG_DEBUG, NULL, workspace, NULL, MS_BIND|MS_REMOUNT|MS_NODEV|MS_NOEXEC|MS_NOSUID, NULL); + if (r < 0) + return r; + + workspace_mounted = true; + } + } else + final_mounted = false; + + if (workspace_mounted < 0) { + /* Nothing is mounted on the workspace yet, let's try to mount something now */ + for (int try = 0;; try++) { + + if (try == 0) { + /* Try "ramfs" first, since it's not swap backed */ + r = mount_nofollow_verbose(LOG_DEBUG, "ramfs", workspace, "ramfs", MS_NODEV|MS_NOEXEC|MS_NOSUID, "mode=0700"); + if (r >= 0) { + workspace_mounted = true; + break; + } + + } else if (try == 1) { + _cleanup_free_ char *opts = NULL; + + if (asprintf(&opts, "mode=0700,nr_inodes=1024,size=%zu", (size_t) CREDENTIALS_TOTAL_SIZE_MAX) < 0) + return -ENOMEM; + + /* Fall back to "tmpfs" otherwise */ + r = mount_nofollow_verbose(LOG_DEBUG, "tmpfs", workspace, "tmpfs", MS_NODEV|MS_NOEXEC|MS_NOSUID, opts); + if (r >= 0) { + workspace_mounted = true; + break; + } + + } else { + /* If that didn't work, try to make a bind mount from the final to the workspace, so that we can make it writable there. */ + r = mount_nofollow_verbose(LOG_DEBUG, final, workspace, NULL, MS_BIND|MS_REC, NULL); + if (r < 0) { + if (!ERRNO_IS_PRIVILEGE(r)) /* Propagate anything that isn't a permission problem */ + return r; + + if (must_mount) /* If we it's not OK to use the plain directory + * fallback, propagate all errors too */ + return r; + + /* If we lack privileges to bind mount stuff, then let's gracefully + * proceed for compat with container envs, and just use the final dir + * as is. */ + + workspace_mounted = false; + break; + } + + /* Make the new bind mount writable (i.e. drop MS_RDONLY) */ + r = mount_nofollow_verbose(LOG_DEBUG, NULL, workspace, NULL, MS_BIND|MS_REMOUNT|MS_NODEV|MS_NOEXEC|MS_NOSUID, NULL); + if (r < 0) + return r; + + workspace_mounted = true; + break; + } + } + } + + assert(!must_mount || workspace_mounted > 0); + where = workspace_mounted ? workspace : final; + + (void) label_fix_full(AT_FDCWD, where, final, 0); + + r = acquire_credentials(context, params, unit, where, uid, workspace_mounted); + if (r < 0) + return r; + + if (workspace_mounted) { + /* Make workspace read-only now, so that any bind mount we make from it defaults to read-only too */ + r = mount_nofollow_verbose(LOG_DEBUG, NULL, workspace, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY|MS_NODEV|MS_NOEXEC|MS_NOSUID, NULL); + if (r < 0) + return r; + + /* And mount it to the final place, read-only */ + if (final_mounted) + r = umount_verbose(LOG_DEBUG, workspace, MNT_DETACH|UMOUNT_NOFOLLOW); + else + r = mount_nofollow_verbose(LOG_DEBUG, workspace, final, NULL, MS_MOVE, NULL); + if (r < 0) + return r; + } else { + _cleanup_free_ char *parent = NULL; + + /* If we do not have our own mount put used the plain directory fallback, then we need to + * open access to the top-level credential directory and the per-service directory now */ + + r = path_extract_directory(final, &parent); + if (r < 0) + return r; + if (chmod(parent, 0755) < 0) + return -errno; + } + + return 0; +} + +static int setup_credentials( + const ExecContext *context, + const ExecParameters *params, + const char *unit, + uid_t uid) { + + _cleanup_free_ char *p = NULL, *q = NULL; + int r; + + assert(context); + assert(params); + + if (!exec_context_has_credentials(context)) + return 0; + + if (!params->prefix[EXEC_DIRECTORY_RUNTIME]) + return -EINVAL; + + /* This where we'll place stuff when we are done; this main credentials directory is world-readable, + * and the subdir we mount over with a read-only file system readable by the service's user */ + q = path_join(params->prefix[EXEC_DIRECTORY_RUNTIME], "credentials"); + if (!q) + return -ENOMEM; + + r = mkdir_label(q, 0755); /* top-level dir: world readable/searchable */ + if (r < 0 && r != -EEXIST) + return r; + + p = path_join(q, unit); + if (!p) + return -ENOMEM; + + r = mkdir_label(p, 0700); /* per-unit dir: private to user */ + if (r < 0 && r != -EEXIST) + return r; + + r = safe_fork("(sd-mkdcreds)", FORK_DEATHSIG|FORK_WAIT|FORK_NEW_MOUNTNS, NULL); + if (r < 0) { + _cleanup_free_ char *t = NULL, *u = NULL; + + /* If this is not a privilege or support issue then propagate the error */ + if (!ERRNO_IS_NOT_SUPPORTED(r) && !ERRNO_IS_PRIVILEGE(r)) + return r; + + /* Temporary workspace, that remains inaccessible all the time. We prepare stuff there before moving + * it into place, so that users can't access half-initialized credential stores. */ + t = path_join(params->prefix[EXEC_DIRECTORY_RUNTIME], "systemd/temporary-credentials"); + if (!t) + return -ENOMEM; + + /* We can't set up a mount namespace. In that case operate on a fixed, inaccessible per-unit + * directory outside of /run/credentials/ first, and then move it over to /run/credentials/ + * after it is fully set up */ + u = path_join(t, unit); + if (!u) + return -ENOMEM; + + FOREACH_STRING(i, t, u) { + r = mkdir_label(i, 0700); + if (r < 0 && r != -EEXIST) + return r; + } + + r = setup_credentials_internal( + context, + params, + unit, + p, /* final mount point */ + u, /* temporary workspace to overmount */ + true, /* reuse the workspace if it is already a mount */ + false, /* it's OK to fall back to a plain directory if we can't mount anything */ + uid); + + (void) rmdir(u); /* remove the workspace again if we can. */ + + if (r < 0) + return r; + + } else if (r == 0) { + + /* We managed to set up a mount namespace, and are now in a child. That's great. In this case + * we can use the same directory for all cases, after turning off propagation. Question + * though is: where do we turn off propagation exactly, and where do we place the workspace + * directory? We need some place that is guaranteed to be a mount point in the host, and + * which is guaranteed to have a subdir we can mount over. /run/ is not suitable for this, + * since we ultimately want to move the resulting file system there, i.e. we need propagation + * for /run/ eventually. We could use our own /run/systemd/bind mount on itself, but that + * would be visible in the host mount table all the time, which we want to avoid. Hence, what + * we do here instead we use /dev/ and /dev/shm/ for our purposes. We know for sure that + * /dev/ is a mount point and we now for sure that /dev/shm/ exists. Hence we can turn off + * propagation on the former, and then overmount the latter. + * + * Yes it's nasty playing games with /dev/ and /dev/shm/ like this, since it does not exist + * for this purpose, but there are few other candidates that work equally well for us, and + * given that the we do this in a privately namespaced short-lived single-threaded process + * that no one else sees this should be OK to do. */ + + r = mount_nofollow_verbose(LOG_DEBUG, NULL, "/dev", NULL, MS_SLAVE|MS_REC, NULL); /* Turn off propagation from our namespace to host */ + if (r < 0) + goto child_fail; + + r = setup_credentials_internal( + context, + params, + unit, + p, /* final mount point */ + "/dev/shm", /* temporary workspace to overmount */ + false, /* do not reuse /dev/shm if it is already a mount, under no circumstances */ + true, /* insist that something is mounted, do not allow fallback to plain directory */ + uid); + if (r < 0) + goto child_fail; + + _exit(EXIT_SUCCESS); + + child_fail: + _exit(EXIT_FAILURE); + } + + return 0; +} + +#if ENABLE_SMACK +static int setup_smack( + const Manager *manager, + const ExecContext *context, + int executable_fd) { + int r; + + assert(context); + assert(executable_fd >= 0); + + if (context->smack_process_label) { + r = mac_smack_apply_pid(0, context->smack_process_label); + if (r < 0) + return r; + } else if (manager->default_smack_process_label) { + _cleanup_free_ char *exec_label = NULL; + + r = mac_smack_read_fd(executable_fd, SMACK_ATTR_EXEC, &exec_label); + if (r < 0 && !ERRNO_IS_XATTR_ABSENT(r)) + return r; + + r = mac_smack_apply_pid(0, exec_label ? : manager->default_smack_process_label); + if (r < 0) + return r; + } + + return 0; +} +#endif + +static int compile_bind_mounts( + const ExecContext *context, + const ExecParameters *params, + BindMount **ret_bind_mounts, + size_t *ret_n_bind_mounts, + char ***ret_empty_directories) { + + _cleanup_strv_free_ char **empty_directories = NULL; + BindMount *bind_mounts; + size_t n, h = 0; + int r; + + assert(context); + assert(params); + assert(ret_bind_mounts); + assert(ret_n_bind_mounts); + assert(ret_empty_directories); + + n = context->n_bind_mounts; + for (ExecDirectoryType t = 0; t < _EXEC_DIRECTORY_TYPE_MAX; t++) { + if (!params->prefix[t]) + continue; + + for (size_t i = 0; i < context->directories[t].n_items; i++) + n += !context->directories[t].items[i].only_create; + } + + if (n <= 0) { + *ret_bind_mounts = NULL; + *ret_n_bind_mounts = 0; + *ret_empty_directories = NULL; + return 0; + } + + bind_mounts = new(BindMount, n); + if (!bind_mounts) + return -ENOMEM; + + for (size_t i = 0; i < context->n_bind_mounts; i++) { + BindMount *item = context->bind_mounts + i; + char *s, *d; + + s = strdup(item->source); + if (!s) { + r = -ENOMEM; + goto finish; + } + + d = strdup(item->destination); + if (!d) { + free(s); + r = -ENOMEM; + goto finish; + } + + bind_mounts[h++] = (BindMount) { + .source = s, + .destination = d, + .read_only = item->read_only, + .recursive = item->recursive, + .ignore_enoent = item->ignore_enoent, + }; + } + + for (ExecDirectoryType t = 0; t < _EXEC_DIRECTORY_TYPE_MAX; t++) { + if (!params->prefix[t]) + continue; + + if (context->directories[t].n_items == 0) + continue; + + if (exec_directory_is_private(context, t) && + !exec_context_with_rootfs(context)) { + char *private_root; + + /* So this is for a dynamic user, and we need to make sure the process can access its own + * directory. For that we overmount the usually inaccessible "private" subdirectory with a + * tmpfs that makes it accessible and is empty except for the submounts we do this for. */ + + private_root = path_join(params->prefix[t], "private"); + if (!private_root) { + r = -ENOMEM; + goto finish; + } + + r = strv_consume(&empty_directories, private_root); + if (r < 0) + goto finish; + } + + for (size_t i = 0; i < context->directories[t].n_items; i++) { + char *s, *d; + + /* When one of the parent directories is in the list, we cannot create the symlink + * for the child directory. See also the comments in setup_exec_directory(). */ + if (context->directories[t].items[i].only_create) + continue; + + if (exec_directory_is_private(context, t)) + s = path_join(params->prefix[t], "private", context->directories[t].items[i].path); + else + s = path_join(params->prefix[t], context->directories[t].items[i].path); + if (!s) { + r = -ENOMEM; + goto finish; + } + + if (exec_directory_is_private(context, t) && + exec_context_with_rootfs(context)) + /* When RootDirectory= or RootImage= are set, then the symbolic link to the private + * directory is not created on the root directory. So, let's bind-mount the directory + * on the 'non-private' place. */ + d = path_join(params->prefix[t], context->directories[t].items[i].path); + else + d = strdup(s); + if (!d) { + free(s); + r = -ENOMEM; + goto finish; + } + + bind_mounts[h++] = (BindMount) { + .source = s, + .destination = d, + .read_only = false, + .nosuid = context->dynamic_user, /* don't allow suid/sgid when DynamicUser= is on */ + .recursive = true, + .ignore_enoent = false, + }; + } + } + + assert(h == n); + + *ret_bind_mounts = bind_mounts; + *ret_n_bind_mounts = n; + *ret_empty_directories = TAKE_PTR(empty_directories); + + return (int) n; + +finish: + bind_mount_free_many(bind_mounts, h); + return r; +} + +/* ret_symlinks will contain a list of pairs src:dest that describes + * the symlinks to create later on. For example, the symlinks needed + * to safely give private directories to DynamicUser=1 users. */ +static int compile_symlinks( + const ExecContext *context, + const ExecParameters *params, + char ***ret_symlinks) { + + _cleanup_strv_free_ char **symlinks = NULL; + int r; + + assert(context); + assert(params); + assert(ret_symlinks); + + for (ExecDirectoryType dt = 0; dt < _EXEC_DIRECTORY_TYPE_MAX; dt++) { + for (size_t i = 0; i < context->directories[dt].n_items; i++) { + _cleanup_free_ char *private_path = NULL, *path = NULL; + + STRV_FOREACH(symlink, context->directories[dt].items[i].symlinks) { + _cleanup_free_ char *src_abs = NULL, *dst_abs = NULL; + + src_abs = path_join(params->prefix[dt], context->directories[dt].items[i].path); + dst_abs = path_join(params->prefix[dt], *symlink); + if (!src_abs || !dst_abs) + return -ENOMEM; + + r = strv_consume_pair(&symlinks, TAKE_PTR(src_abs), TAKE_PTR(dst_abs)); + if (r < 0) + return r; + } + + if (!exec_directory_is_private(context, dt) || + exec_context_with_rootfs(context) || + context->directories[dt].items[i].only_create) + continue; + + private_path = path_join(params->prefix[dt], "private", context->directories[dt].items[i].path); + if (!private_path) + return -ENOMEM; + + path = path_join(params->prefix[dt], context->directories[dt].items[i].path); + if (!path) + return -ENOMEM; + + r = strv_consume_pair(&symlinks, TAKE_PTR(private_path), TAKE_PTR(path)); + if (r < 0) + return r; + } + } + + *ret_symlinks = TAKE_PTR(symlinks); + + return 0; +} + +static bool insist_on_sandboxing( + const ExecContext *context, + const char *root_dir, + const char *root_image, + const BindMount *bind_mounts, + size_t n_bind_mounts) { + + assert(context); + assert(n_bind_mounts == 0 || bind_mounts); + + /* Checks whether we need to insist on fs namespacing. i.e. whether we have settings configured that + * would alter the view on the file system beyond making things read-only or invisible, i.e. would + * rearrange stuff in a way we cannot ignore gracefully. */ + + if (context->n_temporary_filesystems > 0) + return true; + + if (root_dir || root_image) + return true; + + if (context->n_mount_images > 0) + return true; + + if (context->dynamic_user) + return true; + + if (context->n_extension_images > 0 || !strv_isempty(context->extension_directories)) + return true; + + /* If there are any bind mounts set that don't map back onto themselves, fs namespacing becomes + * essential. */ + for (size_t i = 0; i < n_bind_mounts; i++) + if (!path_equal(bind_mounts[i].source, bind_mounts[i].destination)) + return true; + + if (context->log_namespace) + return true; + + return false; +} + +static int apply_mount_namespace( + const Unit *u, + ExecCommandFlags command_flags, + const ExecContext *context, + const ExecParameters *params, + const ExecRuntime *runtime, + char **error_path) { + + _cleanup_strv_free_ char **empty_directories = NULL, **symlinks = NULL; + const char *tmp_dir = NULL, *var_tmp_dir = NULL; + const char *root_dir = NULL, *root_image = NULL; + _cleanup_free_ char *creds_path = NULL, *incoming_dir = NULL, *propagate_dir = NULL, + *extension_dir = NULL; + NamespaceInfo ns_info; + bool needs_sandboxing; + BindMount *bind_mounts = NULL; + size_t n_bind_mounts = 0; + int r; + + assert(context); + + if (params->flags & EXEC_APPLY_CHROOT) { + root_image = context->root_image; + + if (!root_image) + root_dir = context->root_directory; + } + + r = compile_bind_mounts(context, params, &bind_mounts, &n_bind_mounts, &empty_directories); + if (r < 0) + return r; + + /* Symlinks for exec dirs are set up after other mounts, before they are made read-only. */ + r = compile_symlinks(context, params, &symlinks); + if (r < 0) + goto finalize; + + needs_sandboxing = (params->flags & EXEC_APPLY_SANDBOXING) && !(command_flags & EXEC_COMMAND_FULLY_PRIVILEGED); + if (needs_sandboxing) { + /* 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. + * This does not apply when we are using /run/systemd/empty as fallback. */ + + if (context->private_tmp && runtime) { + if (streq_ptr(runtime->tmp_dir, RUN_SYSTEMD_EMPTY)) + tmp_dir = runtime->tmp_dir; + else if (runtime->tmp_dir) + tmp_dir = strjoina(runtime->tmp_dir, "/tmp"); + + if (streq_ptr(runtime->var_tmp_dir, RUN_SYSTEMD_EMPTY)) + var_tmp_dir = runtime->var_tmp_dir; + else if (runtime->var_tmp_dir) + var_tmp_dir = strjoina(runtime->var_tmp_dir, "/tmp"); + } + + ns_info = (NamespaceInfo) { + .ignore_protect_paths = false, + .private_dev = context->private_devices, + .protect_control_groups = context->protect_control_groups, + .protect_kernel_tunables = context->protect_kernel_tunables, + .protect_kernel_modules = context->protect_kernel_modules, + .protect_kernel_logs = context->protect_kernel_logs, + .protect_hostname = context->protect_hostname, + .mount_apivfs = exec_context_get_effective_mount_apivfs(context), + .private_mounts = context->private_mounts, + .protect_home = context->protect_home, + .protect_system = context->protect_system, + .protect_proc = context->protect_proc, + .proc_subset = context->proc_subset, + .private_ipc = context->private_ipc || context->ipc_namespace_path, + /* If NNP is on, we can turn on MS_NOSUID, since it won't have any effect anymore. */ + .mount_nosuid = context->no_new_privileges && !mac_selinux_use(), + }; + } else if (!context->dynamic_user && root_dir) + /* + * If DynamicUser=no and RootDirectory= is set then lets pass a relaxed + * sandbox info, otherwise enforce it, don't ignore protected paths and + * fail if we are enable to apply the sandbox inside the mount namespace. + */ + ns_info = (NamespaceInfo) { + .ignore_protect_paths = true, + }; + else + ns_info = (NamespaceInfo) {}; + + if (context->mount_flags == MS_SHARED) + log_unit_debug(u, "shared mount propagation hidden by other fs namespacing unit settings: ignoring"); + + if (exec_context_has_credentials(context) && + params->prefix[EXEC_DIRECTORY_RUNTIME] && + FLAGS_SET(params->flags, EXEC_WRITE_CREDENTIALS)) { + creds_path = path_join(params->prefix[EXEC_DIRECTORY_RUNTIME], "credentials", u->id); + if (!creds_path) { + r = -ENOMEM; + goto finalize; + } + } + + if (MANAGER_IS_SYSTEM(u->manager)) { + propagate_dir = path_join("/run/systemd/propagate/", u->id); + if (!propagate_dir) { + r = -ENOMEM; + goto finalize; + } + + incoming_dir = strdup("/run/systemd/incoming"); + if (!incoming_dir) { + r = -ENOMEM; + goto finalize; + } + + extension_dir = strdup("/run/systemd/unit-extensions"); + if (!extension_dir) { + r = -ENOMEM; + goto finalize; + } + } else + if (asprintf(&extension_dir, "/run/user/" UID_FMT "/systemd/unit-extensions", geteuid()) < 0) { + r = -ENOMEM; + goto finalize; + } + + r = setup_namespace(root_dir, root_image, context->root_image_options, + &ns_info, context->read_write_paths, + needs_sandboxing ? context->read_only_paths : NULL, + needs_sandboxing ? context->inaccessible_paths : NULL, + needs_sandboxing ? context->exec_paths : NULL, + needs_sandboxing ? context->no_exec_paths : NULL, + empty_directories, + symlinks, + bind_mounts, + n_bind_mounts, + context->temporary_filesystems, + context->n_temporary_filesystems, + context->mount_images, + context->n_mount_images, + tmp_dir, + var_tmp_dir, + creds_path, + context->log_namespace, + context->mount_flags, + context->root_hash, context->root_hash_size, context->root_hash_path, + context->root_hash_sig, context->root_hash_sig_size, context->root_hash_sig_path, + context->root_verity, + context->extension_images, + context->n_extension_images, + context->extension_directories, + propagate_dir, + incoming_dir, + extension_dir, + root_dir || root_image ? params->notify_socket : NULL, + error_path); + + /* If we couldn't set up the namespace this is probably due to a missing capability. setup_namespace() reports + * that with a special, recognizable error ENOANO. In this case, silently proceed, but only if exclusively + * sandboxing options were used, i.e. nothing such as RootDirectory= or BindMount= that would result in a + * completely different execution environment. */ + if (r == -ENOANO) { + if (insist_on_sandboxing( + context, + root_dir, root_image, + bind_mounts, + n_bind_mounts)) { + log_unit_debug(u, "Failed to set up namespace, and refusing to continue since the selected namespacing options alter mount environment non-trivially.\n" + "Bind mounts: %zu, temporary filesystems: %zu, root directory: %s, root image: %s, dynamic user: %s", + n_bind_mounts, context->n_temporary_filesystems, yes_no(root_dir), yes_no(root_image), yes_no(context->dynamic_user)); + + r = -EOPNOTSUPP; + } else { + log_unit_debug(u, "Failed to set up namespace, assuming containerized execution and ignoring."); + r = 0; + } + } + +finalize: + bind_mount_free_many(bind_mounts, n_bind_mounts); + return r; +} + +static int apply_working_directory( + const ExecContext *context, + const ExecParameters *params, + const char *home, + int *exit_status) { + + const char *d, *wd; + + assert(context); + assert(exit_status); + + if (context->working_directory_home) { + + if (!home) { + *exit_status = EXIT_CHDIR; + return -ENXIO; + } + + wd = home; + + } else + wd = empty_to_root(context->working_directory); + + if (params->flags & EXEC_APPLY_CHROOT) + d = wd; + else + d = prefix_roota(context->root_directory, wd); + + if (chdir(d) < 0 && !context->working_directory_missing_ok) { + *exit_status = EXIT_CHDIR; + return -errno; + } + + return 0; +} + +static int apply_root_directory( + const ExecContext *context, + const ExecParameters *params, + const bool needs_mount_ns, + int *exit_status) { + + assert(context); + assert(exit_status); + + if (params->flags & EXEC_APPLY_CHROOT) + if (!needs_mount_ns && context->root_directory) + if (chroot(context->root_directory) < 0) { + *exit_status = EXIT_CHROOT; + return -errno; + } + + return 0; +} + +static int setup_keyring( + const Unit *u, + const ExecContext *context, + const ExecParameters *p, + uid_t uid, gid_t gid) { + + key_serial_t keyring; + int r = 0; + uid_t saved_uid; + gid_t saved_gid; + + assert(u); + assert(context); + assert(p); + + /* Let's set up a new per-service "session" kernel keyring for each system service. This has the benefit that + * each service runs with its own keyring shared among all processes of the service, but with no hook-up beyond + * that scope, and in particular no link to the per-UID keyring. If we don't do this the keyring will be + * automatically created on-demand and then linked to the per-UID keyring, by the kernel. The kernel's built-in + * on-demand behaviour is very appropriate for login users, but probably not so much for system services, where + * UIDs are not necessarily specific to a service but reused (at least in the case of UID 0). */ + + if (context->keyring_mode == EXEC_KEYRING_INHERIT) + return 0; + + /* Acquiring a reference to the user keyring is nasty. We briefly change identity in order to get things set up + * properly by the kernel. If we don't do that then we can't create it atomically, and that sucks for parallel + * execution. This mimics what pam_keyinit does, too. Setting up session keyring, to be owned by the right user + * & group is just as nasty as acquiring a reference to the user keyring. */ + + saved_uid = getuid(); + saved_gid = getgid(); + + if (gid_is_valid(gid) && gid != saved_gid) { + if (setregid(gid, -1) < 0) + return log_unit_error_errno(u, errno, "Failed to change GID for user keyring: %m"); + } + + if (uid_is_valid(uid) && uid != saved_uid) { + if (setreuid(uid, -1) < 0) { + r = log_unit_error_errno(u, errno, "Failed to change UID for user keyring: %m"); + goto out; + } + } + + keyring = keyctl(KEYCTL_JOIN_SESSION_KEYRING, 0, 0, 0, 0); + if (keyring == -1) { + if (errno == ENOSYS) + log_unit_debug_errno(u, errno, "Kernel keyring not supported, ignoring."); + else if (ERRNO_IS_PRIVILEGE(errno)) + log_unit_debug_errno(u, errno, "Kernel keyring access prohibited, ignoring."); + else if (errno == EDQUOT) + log_unit_debug_errno(u, errno, "Out of kernel keyrings to allocate, ignoring."); + else + r = log_unit_error_errno(u, errno, "Setting up kernel keyring failed: %m"); + + goto out; + } + + /* When requested link the user keyring into the session keyring. */ + if (context->keyring_mode == EXEC_KEYRING_SHARED) { + + if (keyctl(KEYCTL_LINK, + KEY_SPEC_USER_KEYRING, + KEY_SPEC_SESSION_KEYRING, 0, 0) < 0) { + r = log_unit_error_errno(u, errno, "Failed to link user keyring into session keyring: %m"); + goto out; + } + } + + /* Restore uid/gid back */ + if (uid_is_valid(uid) && uid != saved_uid) { + if (setreuid(saved_uid, -1) < 0) { + r = log_unit_error_errno(u, errno, "Failed to change UID back for user keyring: %m"); + goto out; + } + } + + if (gid_is_valid(gid) && gid != saved_gid) { + if (setregid(saved_gid, -1) < 0) + return log_unit_error_errno(u, errno, "Failed to change GID back for user keyring: %m"); + } + + /* Populate they keyring with the invocation ID by default, as original saved_uid. */ + if (!sd_id128_is_null(u->invocation_id)) { + key_serial_t key; + + key = add_key("user", "invocation_id", &u->invocation_id, sizeof(u->invocation_id), KEY_SPEC_SESSION_KEYRING); + if (key == -1) + log_unit_debug_errno(u, errno, "Failed to add invocation ID to keyring, ignoring: %m"); + else { + if (keyctl(KEYCTL_SETPERM, key, + KEY_POS_VIEW|KEY_POS_READ|KEY_POS_SEARCH| + KEY_USR_VIEW|KEY_USR_READ|KEY_USR_SEARCH, 0, 0) < 0) + r = log_unit_error_errno(u, errno, "Failed to restrict invocation ID permission: %m"); + } + } + +out: + /* Revert back uid & gid for the last time, and exit */ + /* no extra logging, as only the first already reported error matters */ + if (getuid() != saved_uid) + (void) setreuid(saved_uid, -1); + + if (getgid() != saved_gid) + (void) setregid(saved_gid, -1); + + return r; +} + +static void append_socket_pair(int *array, size_t *n, const int pair[static 2]) { + assert(array); + assert(n); + assert(pair); + + if (pair[0] >= 0) + array[(*n)++] = pair[0]; + if (pair[1] >= 0) + array[(*n)++] = pair[1]; +} + +static int close_remaining_fds( + const ExecParameters *params, + const ExecRuntime *runtime, + const DynamicCreds *dcreds, + int user_lookup_fd, + int socket_fd, + const int *fds, size_t n_fds) { + + size_t n_dont_close = 0; + int dont_close[n_fds + 12]; + + assert(params); + + if (params->stdin_fd >= 0) + dont_close[n_dont_close++] = params->stdin_fd; + if (params->stdout_fd >= 0) + dont_close[n_dont_close++] = params->stdout_fd; + if (params->stderr_fd >= 0) + dont_close[n_dont_close++] = params->stderr_fd; + + 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) { + append_socket_pair(dont_close, &n_dont_close, runtime->netns_storage_socket); + append_socket_pair(dont_close, &n_dont_close, runtime->ipcns_storage_socket); + } + + if (dcreds) { + if (dcreds->user) + append_socket_pair(dont_close, &n_dont_close, dcreds->user->storage_socket); + if (dcreds->group) + append_socket_pair(dont_close, &n_dont_close, dcreds->group->storage_socket); + } + + if (user_lookup_fd >= 0) + dont_close[n_dont_close++] = user_lookup_fd; + + return close_all_fds(dont_close, n_dont_close); +} + +static int send_user_lookup( + Unit *unit, + int user_lookup_fd, + uid_t uid, + gid_t gid) { + + assert(unit); + + /* Send the resolved UID/GID to PID 1 after we learnt it. We send a single datagram, containing the UID/GID + * data as well as the unit name. Note that we suppress sending this if no user/group to resolve was + * specified. */ + + if (user_lookup_fd < 0) + return 0; + + if (!uid_is_valid(uid) && !gid_is_valid(gid)) + return 0; + + if (writev(user_lookup_fd, + (struct iovec[]) { + IOVEC_INIT(&uid, sizeof(uid)), + IOVEC_INIT(&gid, sizeof(gid)), + IOVEC_INIT_STRING(unit->id) }, 3) < 0) + return -errno; + + return 0; +} + +static int acquire_home(const ExecContext *c, uid_t uid, const char** home, char **buf) { + int r; + + assert(c); + assert(home); + assert(buf); + + /* If WorkingDirectory=~ is set, try to acquire a usable home directory. */ + + if (*home) + return 0; + + if (!c->working_directory_home) + return 0; + + r = get_home_dir(buf); + if (r < 0) + return r; + + *home = *buf; + return 1; +} + +static int compile_suggested_paths(const ExecContext *c, const ExecParameters *p, char ***ret) { + _cleanup_strv_free_ char ** list = NULL; + int r; + + assert(c); + assert(p); + assert(ret); + + assert(c->dynamic_user); + + /* Compile a list of paths that it might make sense to read the owning UID from to use as initial candidate for + * dynamic UID allocation, in order to save us from doing costly recursive chown()s of the special + * directories. */ + + for (ExecDirectoryType t = 0; t < _EXEC_DIRECTORY_TYPE_MAX; t++) { + if (t == EXEC_DIRECTORY_CONFIGURATION) + continue; + + if (!p->prefix[t]) + continue; + + for (size_t i = 0; i < c->directories[t].n_items; i++) { + char *e; + + if (exec_directory_is_private(c, t)) + e = path_join(p->prefix[t], "private", c->directories[t].items[i].path); + else + e = path_join(p->prefix[t], c->directories[t].items[i].path); + if (!e) + return -ENOMEM; + + r = strv_consume(&list, e); + if (r < 0) + return r; + } + } + + *ret = TAKE_PTR(list); + + return 0; +} + +static int exec_parameters_get_cgroup_path(const ExecParameters *params, char **ret) { + bool using_subcgroup; + char *p; + + assert(params); + assert(ret); + + if (!params->cgroup_path) + return -EINVAL; + + /* If we are called for a unit where cgroup delegation is on, and the payload created its own populated + * subcgroup (which we expect it to do, after all it asked for delegation), then we cannot place the control + * processes started after the main unit's process in the unit's main cgroup because it is now an inner one, + * and inner cgroups may not contain processes. Hence, if delegation is on, and this is a control process, + * let's use ".control" as subcgroup instead. Note that we do so only for ExecStartPost=, ExecReload=, + * ExecStop=, ExecStopPost=, i.e. for the commands where the main process is already forked. For ExecStartPre= + * this is not necessary, the cgroup is still empty. We distinguish these cases with the EXEC_CONTROL_CGROUP + * flag, which is only passed for the former statements, not for the latter. */ + + using_subcgroup = FLAGS_SET(params->flags, EXEC_CONTROL_CGROUP|EXEC_CGROUP_DELEGATE|EXEC_IS_CONTROL); + if (using_subcgroup) + p = path_join(params->cgroup_path, ".control"); + else + p = strdup(params->cgroup_path); + if (!p) + return -ENOMEM; + + *ret = p; + return using_subcgroup; +} + +static int exec_context_cpu_affinity_from_numa(const ExecContext *c, CPUSet *ret) { + _cleanup_(cpu_set_reset) CPUSet s = {}; + int r; + + assert(c); + assert(ret); + + if (!c->numa_policy.nodes.set) { + log_debug("Can't derive CPU affinity mask from NUMA mask because NUMA mask is not set, ignoring"); + return 0; + } + + r = numa_to_cpu_set(&c->numa_policy, &s); + if (r < 0) + return r; + + cpu_set_reset(ret); + + return cpu_set_add_all(ret, &s); +} + +bool exec_context_get_cpu_affinity_from_numa(const ExecContext *c) { + assert(c); + + return c->cpu_affinity_from_numa; +} + +static int add_shifted_fd(int *fds, size_t fds_size, size_t *n_fds, int fd, int *ret_fd) { + int r; + + assert(fds); + assert(n_fds); + assert(*n_fds < fds_size); + assert(ret_fd); + + if (fd < 0) { + *ret_fd = -1; + return 0; + } + + if (fd < 3 + (int) *n_fds) { + /* Let's move the fd up, so that it's outside of the fd range we will use to store + * the fds we pass to the process (or which are closed only during execve). */ + + r = fcntl(fd, F_DUPFD_CLOEXEC, 3 + (int) *n_fds); + if (r < 0) + return -errno; + + close_and_replace(fd, r); + } + + *ret_fd = fds[*n_fds] = fd; + (*n_fds) ++; + return 1; +} + +static int exec_child( + Unit *unit, + const ExecCommand *command, + const ExecContext *context, + const ExecParameters *params, + ExecRuntime *runtime, + DynamicCreds *dcreds, + int socket_fd, + const int named_iofds[static 3], + int *fds, + size_t n_socket_fds, + size_t n_storage_fds, + char **files_env, + int user_lookup_fd, + int *exit_status) { + + _cleanup_strv_free_ char **our_env = NULL, **pass_env = NULL, **joined_exec_search_path = NULL, **accum_env = NULL, **replaced_argv = NULL; + int r, ngids = 0, exec_fd; + _cleanup_free_ gid_t *supplementary_gids = NULL; + const char *username = NULL, *groupname = NULL; + _cleanup_free_ char *home_buffer = NULL; + const char *home = NULL, *shell = NULL; + char **final_argv = NULL; + dev_t journal_stream_dev = 0; + ino_t journal_stream_ino = 0; + bool userns_set_up = false; + bool needs_sandboxing, /* Do we need to set up full sandboxing? (i.e. all namespacing, all MAC stuff, caps, yadda yadda */ + needs_setuid, /* Do we need to do the actual setresuid()/setresgid() calls? */ + needs_mount_namespace, /* Do we need to set up a mount namespace for this kernel? */ + needs_ambient_hack; /* Do we need to apply the ambient capabilities hack? */ +#if HAVE_SELINUX + _cleanup_free_ char *mac_selinux_context_net = NULL; + bool use_selinux = false; +#endif +#if ENABLE_SMACK + bool use_smack = false; +#endif +#if HAVE_APPARMOR + bool use_apparmor = false; +#endif + uid_t saved_uid = getuid(); + gid_t saved_gid = getgid(); + uid_t uid = UID_INVALID; + gid_t gid = GID_INVALID; + size_t n_fds = n_socket_fds + n_storage_fds, /* fds to pass to the child */ + n_keep_fds; /* total number of fds not to close */ + int secure_bits; + _cleanup_free_ gid_t *gids_after_pam = NULL; + int ngids_after_pam = 0; + + assert(unit); + assert(command); + assert(context); + assert(params); + assert(exit_status); + + /* Explicitly test for CVE-2021-4034 inspired invocations */ + assert(command->path); + assert(!strv_isempty(command->argv)); + + 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. */ + (void) default_signals(SIGNALS_CRASH_HANDLER, + SIGNALS_IGNORE); + + if (context->ignore_sigpipe) + (void) ignore_signals(SIGPIPE); + + r = reset_signal_mask(); + if (r < 0) { + *exit_status = EXIT_SIGNAL_MASK; + return log_unit_error_errno(unit, r, "Failed to set process signal mask: %m"); + } + + if (params->idle_pipe) + do_idle_pipe_dance(params->idle_pipe); + + /* Close fds we don't need very early to make sure we don't block init reexecution because it cannot bind its + * sockets. Among the fds we close are the logging fds, and we want to keep them closed, so that we don't have + * any fds open we don't really want open during the transition. In order to make logging work, we switch the + * log subsystem into open_when_needed mode, so that it reopens the logs on every single log call. */ + + log_forget_fds(); + log_set_open_when_needed(true); + log_settle_target(); + if (context->log_level_max >= 0) + log_set_max_level(context->log_level_max); + + /* In case anything used libc syslog(), close this here, too */ + closelog(); + + int keep_fds[n_fds + 3]; + memcpy_safe(keep_fds, fds, n_fds * sizeof(int)); + n_keep_fds = n_fds; + + r = add_shifted_fd(keep_fds, ELEMENTSOF(keep_fds), &n_keep_fds, params->exec_fd, &exec_fd); + if (r < 0) { + *exit_status = EXIT_FDS; + return log_unit_error_errno(unit, r, "Failed to shift fd and set FD_CLOEXEC: %m"); + } + +#if HAVE_LIBBPF + if (unit->manager->restrict_fs) { + int bpf_map_fd = lsm_bpf_map_restrict_fs_fd(unit); + if (bpf_map_fd < 0) { + *exit_status = EXIT_FDS; + return log_unit_error_errno(unit, bpf_map_fd, "Failed to get restrict filesystems BPF map fd: %m"); + } + + r = add_shifted_fd(keep_fds, ELEMENTSOF(keep_fds), &n_keep_fds, bpf_map_fd, &bpf_map_fd); + if (r < 0) { + *exit_status = EXIT_FDS; + return log_unit_error_errno(unit, r, "Failed to shift fd and set FD_CLOEXEC: %m"); + } + } +#endif + + r = close_remaining_fds(params, runtime, dcreds, user_lookup_fd, socket_fd, keep_fds, n_keep_fds); + if (r < 0) { + *exit_status = EXIT_FDS; + return log_unit_error_errno(unit, r, "Failed to close unwanted file descriptors: %m"); + } + + if (!context->same_pgrp && + setsid() < 0) { + *exit_status = EXIT_SETSID; + return log_unit_error_errno(unit, errno, "Failed to create new process session: %m"); + } + + exec_context_tty_reset(context, params); + + if (unit_shall_confirm_spawn(unit)) { + _cleanup_free_ char *cmdline = NULL; + + cmdline = quote_command_line(command->argv, SHELL_ESCAPE_EMPTY); + if (!cmdline) { + *exit_status = EXIT_MEMORY; + return log_oom(); + } + + r = ask_for_confirmation(context, params->confirm_spawn, unit, cmdline); + if (r != CONFIRM_EXECUTE) { + if (r == CONFIRM_PRETEND_SUCCESS) { + *exit_status = EXIT_SUCCESS; + return 0; + } + + *exit_status = EXIT_CONFIRM; + return log_unit_error_errno(unit, SYNTHETIC_ERRNO(ECANCELED), + "Execution cancelled by the user"); + } + } + + /* We are about to invoke NSS and PAM modules. Let's tell them what we are doing here, maybe they care. This is + * used by nss-resolve to disable itself when we are about to start systemd-resolved, to avoid deadlocks. Note + * that these env vars do not survive the execve(), which means they really only apply to the PAM and NSS + * invocations themselves. Also note that while we'll only invoke NSS modules involved in user management they + * might internally call into other NSS modules that are involved in hostname resolution, we never know. */ + if (setenv("SYSTEMD_ACTIVATION_UNIT", unit->id, true) != 0 || + setenv("SYSTEMD_ACTIVATION_SCOPE", MANAGER_IS_SYSTEM(unit->manager) ? "system" : "user", true) != 0) { + *exit_status = EXIT_MEMORY; + return log_unit_error_errno(unit, errno, "Failed to update environment: %m"); + } + + if (context->dynamic_user && dcreds) { + _cleanup_strv_free_ char **suggested_paths = NULL; + + /* On top of that, make sure we bypass our own NSS module nss-systemd comprehensively for any NSS + * checks, if DynamicUser=1 is used, as we shouldn't create a feedback loop with ourselves here. */ + if (putenv((char*) "SYSTEMD_NSS_DYNAMIC_BYPASS=1") != 0) { + *exit_status = EXIT_USER; + return log_unit_error_errno(unit, errno, "Failed to update environment: %m"); + } + + r = compile_suggested_paths(context, params, &suggested_paths); + if (r < 0) { + *exit_status = EXIT_MEMORY; + return log_oom(); + } + + r = dynamic_creds_realize(dcreds, suggested_paths, &uid, &gid); + if (r < 0) { + *exit_status = EXIT_USER; + if (r == -EILSEQ) + return log_unit_error_errno(unit, SYNTHETIC_ERRNO(EOPNOTSUPP), + "Failed to update dynamic user credentials: User or group with specified name already exists."); + return log_unit_error_errno(unit, r, "Failed to update dynamic user credentials: %m"); + } + + if (!uid_is_valid(uid)) { + *exit_status = EXIT_USER; + return log_unit_error_errno(unit, SYNTHETIC_ERRNO(ESRCH), "UID validation failed for \""UID_FMT"\"", uid); + } + + if (!gid_is_valid(gid)) { + *exit_status = EXIT_USER; + return log_unit_error_errno(unit, SYNTHETIC_ERRNO(ESRCH), "GID validation failed for \""GID_FMT"\"", gid); + } + + if (dcreds->user) + username = dcreds->user->name; + + } else { + r = get_fixed_user(context, &username, &uid, &gid, &home, &shell); + if (r < 0) { + *exit_status = EXIT_USER; + return log_unit_error_errno(unit, r, "Failed to determine user credentials: %m"); + } + + r = get_fixed_group(context, &groupname, &gid); + if (r < 0) { + *exit_status = EXIT_GROUP; + return log_unit_error_errno(unit, r, "Failed to determine group credentials: %m"); + } + } + + /* Initialize user supplementary groups and get SupplementaryGroups= ones */ + r = get_supplementary_groups(context, username, groupname, gid, + &supplementary_gids, &ngids); + if (r < 0) { + *exit_status = EXIT_GROUP; + return log_unit_error_errno(unit, r, "Failed to determine supplementary groups: %m"); + } + + r = send_user_lookup(unit, user_lookup_fd, uid, gid); + if (r < 0) { + *exit_status = EXIT_USER; + return log_unit_error_errno(unit, r, "Failed to send user credentials to PID1: %m"); + } + + user_lookup_fd = safe_close(user_lookup_fd); + + r = acquire_home(context, uid, &home, &home_buffer); + if (r < 0) { + *exit_status = EXIT_CHDIR; + return log_unit_error_errno(unit, r, "Failed to determine $HOME for user: %m"); + } + + /* If a socket is connected to STDIN/STDOUT/STDERR, we + * must sure to drop O_NONBLOCK */ + if (socket_fd >= 0) + (void) fd_nonblock(socket_fd, false); + + /* Journald will try to look-up our cgroup in order to populate _SYSTEMD_CGROUP and _SYSTEMD_UNIT fields. + * Hence we need to migrate to the target cgroup from init.scope before connecting to journald */ + if (params->cgroup_path) { + _cleanup_free_ char *p = NULL; + + r = exec_parameters_get_cgroup_path(params, &p); + if (r < 0) { + *exit_status = EXIT_CGROUP; + return log_unit_error_errno(unit, r, "Failed to acquire cgroup path: %m"); + } + + r = cg_attach_everywhere(params->cgroup_supported, p, 0, NULL, NULL); + if (r == -EUCLEAN) { + *exit_status = EXIT_CGROUP; + return log_unit_error_errno(unit, r, "Failed to attach process to cgroup %s " + "because the cgroup or one of its parents or " + "siblings is in the threaded mode: %m", p); + } + if (r < 0) { + *exit_status = EXIT_CGROUP; + return log_unit_error_errno(unit, r, "Failed to attach to cgroup %s: %m", p); + } + } + + if (context->network_namespace_path && runtime && runtime->netns_storage_socket[0] >= 0) { + r = open_shareable_ns_path(runtime->netns_storage_socket, context->network_namespace_path, CLONE_NEWNET); + if (r < 0) { + *exit_status = EXIT_NETWORK; + return log_unit_error_errno(unit, r, "Failed to open network namespace path %s: %m", context->network_namespace_path); + } + } + + if (context->ipc_namespace_path && runtime && runtime->ipcns_storage_socket[0] >= 0) { + r = open_shareable_ns_path(runtime->ipcns_storage_socket, context->ipc_namespace_path, CLONE_NEWIPC); + if (r < 0) { + *exit_status = EXIT_NAMESPACE; + return log_unit_error_errno(unit, r, "Failed to open IPC namespace path %s: %m", context->ipc_namespace_path); + } + } + + r = setup_input(context, params, socket_fd, named_iofds); + if (r < 0) { + *exit_status = EXIT_STDIN; + return log_unit_error_errno(unit, r, "Failed to set up standard input: %m"); + } + + r = setup_output(unit, context, params, STDOUT_FILENO, socket_fd, named_iofds, basename(command->path), uid, gid, &journal_stream_dev, &journal_stream_ino); + if (r < 0) { + *exit_status = EXIT_STDOUT; + return log_unit_error_errno(unit, r, "Failed to set up standard output: %m"); + } + + r = setup_output(unit, context, params, STDERR_FILENO, socket_fd, named_iofds, basename(command->path), uid, gid, &journal_stream_dev, &journal_stream_ino); + if (r < 0) { + *exit_status = EXIT_STDERR; + return log_unit_error_errno(unit, r, "Failed to set up standard error output: %m"); + } + + if (context->oom_score_adjust_set) { + /* When we can't make this change due to EPERM, then let's silently skip over it. User namespaces + * prohibit write access to this file, and we shouldn't trip up over that. */ + r = set_oom_score_adjust(context->oom_score_adjust); + if (ERRNO_IS_PRIVILEGE(r)) + log_unit_debug_errno(unit, r, "Failed to adjust OOM setting, assuming containerized execution, ignoring: %m"); + else if (r < 0) { + *exit_status = EXIT_OOM_ADJUST; + return log_unit_error_errno(unit, r, "Failed to adjust OOM setting: %m"); + } + } + + if (context->coredump_filter_set) { + r = set_coredump_filter(context->coredump_filter); + if (ERRNO_IS_PRIVILEGE(r)) + log_unit_debug_errno(unit, r, "Failed to adjust coredump_filter, ignoring: %m"); + else if (r < 0) { + *exit_status = EXIT_LIMITS; + return log_unit_error_errno(unit, r, "Failed to adjust coredump_filter: %m"); + } + } + + if (context->nice_set) { + r = setpriority_closest(context->nice); + if (r < 0) { + *exit_status = EXIT_NICE; + return log_unit_error_errno(unit, r, "Failed to set up process scheduling priority (nice level): %m"); + } + } + + 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), + ¶m); + if (r < 0) { + *exit_status = EXIT_SETSCHEDULER; + return log_unit_error_errno(unit, errno, "Failed to set up CPU scheduling: %m"); + } + } + + if (context->cpu_affinity_from_numa || context->cpu_set.set) { + _cleanup_(cpu_set_reset) CPUSet converted_cpu_set = {}; + const CPUSet *cpu_set; + + if (context->cpu_affinity_from_numa) { + r = exec_context_cpu_affinity_from_numa(context, &converted_cpu_set); + if (r < 0) { + *exit_status = EXIT_CPUAFFINITY; + return log_unit_error_errno(unit, r, "Failed to derive CPU affinity mask from NUMA mask: %m"); + } + + cpu_set = &converted_cpu_set; + } else + cpu_set = &context->cpu_set; + + if (sched_setaffinity(0, cpu_set->allocated, cpu_set->set) < 0) { + *exit_status = EXIT_CPUAFFINITY; + return log_unit_error_errno(unit, errno, "Failed to set up CPU affinity: %m"); + } + } + + if (mpol_is_valid(numa_policy_get_type(&context->numa_policy))) { + r = apply_numa_policy(&context->numa_policy); + if (r == -EOPNOTSUPP) + log_unit_debug_errno(unit, r, "NUMA support not available, ignoring."); + else if (r < 0) { + *exit_status = EXIT_NUMA_POLICY; + return log_unit_error_errno(unit, r, "Failed to set NUMA memory policy: %m"); + } + } + + if (context->ioprio_set) + if (ioprio_set(IOPRIO_WHO_PROCESS, 0, context->ioprio) < 0) { + *exit_status = EXIT_IOPRIO; + return log_unit_error_errno(unit, errno, "Failed to set up IO scheduling priority: %m"); + } + + if (context->timer_slack_nsec != NSEC_INFINITY) + if (prctl(PR_SET_TIMERSLACK, context->timer_slack_nsec) < 0) { + *exit_status = EXIT_TIMERSLACK; + return log_unit_error_errno(unit, errno, "Failed to set up timer slack: %m"); + } + + if (context->personality != PERSONALITY_INVALID) { + r = safe_personality(context->personality); + if (r < 0) { + *exit_status = EXIT_PERSONALITY; + return log_unit_error_errno(unit, r, "Failed to set up execution domain (personality): %m"); + } + } + + if (context->utmp_id) { + const char *line = context->tty_path ? + (path_startswith(context->tty_path, "/dev/") ?: context->tty_path) : + NULL; + utmp_put_init_process(context->utmp_id, getpid_cached(), getsid(0), + line, + context->utmp_mode == EXEC_UTMP_INIT ? INIT_PROCESS : + context->utmp_mode == EXEC_UTMP_LOGIN ? LOGIN_PROCESS : + USER_PROCESS, + username); + } + + if (uid_is_valid(uid)) { + r = chown_terminal(STDIN_FILENO, uid); + if (r < 0) { + *exit_status = EXIT_STDIN; + return log_unit_error_errno(unit, r, "Failed to change ownership of terminal: %m"); + } + } + + /* If delegation is enabled we'll pass ownership of the cgroup to the user of the new process. On cgroup v1 + * this is only about systemd's own hierarchy, i.e. not the controller hierarchies, simply because that's not + * safe. On cgroup v2 there's only one hierarchy anyway, and delegation is safe there, hence in that case only + * touch a single hierarchy too. */ + if (params->cgroup_path && context->user && (params->flags & EXEC_CGROUP_DELEGATE)) { + r = cg_set_access(SYSTEMD_CGROUP_CONTROLLER, params->cgroup_path, uid, gid); + if (r < 0) { + *exit_status = EXIT_CGROUP; + return log_unit_error_errno(unit, r, "Failed to adjust control group access: %m"); + } + } + + needs_mount_namespace = exec_needs_mount_namespace(context, params, runtime); + + for (ExecDirectoryType dt = 0; dt < _EXEC_DIRECTORY_TYPE_MAX; dt++) { + r = setup_exec_directory(context, params, uid, gid, dt, needs_mount_namespace, exit_status); + if (r < 0) + return log_unit_error_errno(unit, r, "Failed to set up special execution directory in %s: %m", params->prefix[dt]); + } + + if (FLAGS_SET(params->flags, EXEC_WRITE_CREDENTIALS)) { + r = setup_credentials(context, params, unit->id, uid); + if (r < 0) { + *exit_status = EXIT_CREDENTIALS; + return log_unit_error_errno(unit, r, "Failed to set up credentials: %m"); + } + } + + r = build_environment( + unit, + context, + params, + n_fds, + home, + username, + shell, + journal_stream_dev, + journal_stream_ino, + &our_env); + if (r < 0) { + *exit_status = EXIT_MEMORY; + return log_oom(); + } + + r = build_pass_environment(context, &pass_env); + if (r < 0) { + *exit_status = EXIT_MEMORY; + return log_oom(); + } + + /* The $PATH variable is set to the default path in params->environment. However, this is overridden + * if user-specified fields have $PATH set. The intention is to also override $PATH if the unit does + * not specify PATH but the unit has ExecSearchPath. */ + if (!strv_isempty(context->exec_search_path)) { + _cleanup_free_ char *joined = NULL; + + joined = strv_join(context->exec_search_path, ":"); + if (!joined) { + *exit_status = EXIT_MEMORY; + return log_oom(); + } + + r = strv_env_assign(&joined_exec_search_path, "PATH", joined); + if (r < 0) { + *exit_status = EXIT_MEMORY; + return log_oom(); + } + } + + accum_env = strv_env_merge(params->environment, + our_env, + joined_exec_search_path, + pass_env, + context->environment, + files_env); + if (!accum_env) { + *exit_status = EXIT_MEMORY; + return log_oom(); + } + accum_env = strv_env_clean(accum_env); + + (void) umask(context->umask); + + r = setup_keyring(unit, context, params, uid, gid); + if (r < 0) { + *exit_status = EXIT_KEYRING; + return log_unit_error_errno(unit, r, "Failed to set up kernel keyring: %m"); + } + + /* We need sandboxing if the caller asked us to apply it and the command isn't explicitly excepted + * from it. */ + needs_sandboxing = (params->flags & EXEC_APPLY_SANDBOXING) && !(command->flags & EXEC_COMMAND_FULLY_PRIVILEGED); + + /* We need the ambient capability hack, if the caller asked us to apply it and the command is marked + * for it, and the kernel doesn't actually support ambient caps. */ + needs_ambient_hack = (params->flags & EXEC_APPLY_SANDBOXING) && (command->flags & EXEC_COMMAND_AMBIENT_MAGIC) && !ambient_capabilities_supported(); + + /* We need setresuid() if the caller asked us to apply sandboxing and the command isn't explicitly + * excepted from either whole sandboxing or just setresuid() itself, and the ambient hack is not + * desired. */ + if (needs_ambient_hack) + needs_setuid = false; + else + needs_setuid = (params->flags & EXEC_APPLY_SANDBOXING) && !(command->flags & (EXEC_COMMAND_FULLY_PRIVILEGED|EXEC_COMMAND_NO_SETUID)); + + if (needs_sandboxing) { + /* MAC enablement checks need to be done before a new mount ns is created, as they rely on + * /sys being present. The actual MAC context application will happen later, as late as + * possible, to avoid impacting our own code paths. */ + +#if HAVE_SELINUX + use_selinux = mac_selinux_use(); +#endif +#if ENABLE_SMACK + use_smack = mac_smack_use(); +#endif +#if HAVE_APPARMOR + use_apparmor = mac_apparmor_use(); +#endif + } + + if (needs_sandboxing) { + int which_failed; + + /* Let's set the resource limits before we call into PAM, so that pam_limits wins over what + * is set here. (See below.) */ + + r = setrlimit_closest_all((const struct rlimit* const *) context->rlimit, &which_failed); + if (r < 0) { + *exit_status = EXIT_LIMITS; + return log_unit_error_errno(unit, r, "Failed to adjust resource limit RLIMIT_%s: %m", rlimit_to_string(which_failed)); + } + } + + if (needs_setuid && context->pam_name && username) { + /* Let's call into PAM after we set up our own idea of resource limits to that pam_limits + * wins here. (See above.) */ + + /* All fds passed in the fds array will be closed in the pam child process. */ + r = setup_pam(context->pam_name, username, uid, gid, context->tty_path, &accum_env, fds, n_fds); + if (r < 0) { + *exit_status = EXIT_PAM; + return log_unit_error_errno(unit, r, "Failed to set up PAM session: %m"); + } + + ngids_after_pam = getgroups_alloc(&gids_after_pam); + if (ngids_after_pam < 0) { + *exit_status = EXIT_MEMORY; + return log_unit_error_errno(unit, ngids_after_pam, "Failed to obtain groups after setting up PAM: %m"); + } + } + + if (needs_sandboxing && context->private_users && !have_effective_cap(CAP_SYS_ADMIN)) { + /* If we're unprivileged, set up the user namespace first to enable use of the other namespaces. + * Users with CAP_SYS_ADMIN can set up user namespaces last because they will be able to + * set up the all of the other namespaces (i.e. network, mount, UTS) without a user namespace. */ + + userns_set_up = true; + r = setup_private_users(saved_uid, saved_gid, uid, gid); + if (r < 0) { + *exit_status = EXIT_USER; + return log_unit_error_errno(unit, r, "Failed to set up user namespacing for unprivileged user: %m"); + } + } + + if ((context->private_network || context->network_namespace_path) && runtime && runtime->netns_storage_socket[0] >= 0) { + + if (ns_type_supported(NAMESPACE_NET)) { + r = setup_shareable_ns(runtime->netns_storage_socket, CLONE_NEWNET); + if (r == -EPERM) + log_unit_warning_errno(unit, r, + "PrivateNetwork=yes is configured, but network namespace setup failed, ignoring: %m"); + else if (r < 0) { + *exit_status = EXIT_NETWORK; + return log_unit_error_errno(unit, r, "Failed to set up network namespacing: %m"); + } + } else if (context->network_namespace_path) { + *exit_status = EXIT_NETWORK; + return log_unit_error_errno(unit, SYNTHETIC_ERRNO(EOPNOTSUPP), + "NetworkNamespacePath= is not supported, refusing."); + } else + log_unit_warning(unit, "PrivateNetwork=yes is configured, but the kernel does not support network namespaces, ignoring."); + } + + if ((context->private_ipc || context->ipc_namespace_path) && runtime && runtime->ipcns_storage_socket[0] >= 0) { + + if (ns_type_supported(NAMESPACE_IPC)) { + r = setup_shareable_ns(runtime->ipcns_storage_socket, CLONE_NEWIPC); + if (r == -EPERM) + log_unit_warning_errno(unit, r, + "PrivateIPC=yes is configured, but IPC namespace setup failed, ignoring: %m"); + else if (r < 0) { + *exit_status = EXIT_NAMESPACE; + return log_unit_error_errno(unit, r, "Failed to set up IPC namespacing: %m"); + } + } else if (context->ipc_namespace_path) { + *exit_status = EXIT_NAMESPACE; + return log_unit_error_errno(unit, SYNTHETIC_ERRNO(EOPNOTSUPP), + "IPCNamespacePath= is not supported, refusing."); + } else + log_unit_warning(unit, "PrivateIPC=yes is configured, but the kernel does not support IPC namespaces, ignoring."); + } + + if (needs_mount_namespace) { + _cleanup_free_ char *error_path = NULL; + + r = apply_mount_namespace(unit, command->flags, context, params, runtime, &error_path); + if (r < 0) { + *exit_status = EXIT_NAMESPACE; + return log_unit_error_errno(unit, r, "Failed to set up mount namespacing%s%s: %m", + error_path ? ": " : "", strempty(error_path)); + } + } + + if (needs_sandboxing) { + r = apply_protect_hostname(unit, context, exit_status); + if (r < 0) + return r; + } + + /* Drop groups as early as possible. + * This needs to be done after PrivateDevices=y setup as device nodes should be owned by the host's root. + * For non-root in a userns, devices will be owned by the user/group before the group change, and nobody. */ + if (needs_setuid) { + _cleanup_free_ gid_t *gids_to_enforce = NULL; + int ngids_to_enforce = 0; + + ngids_to_enforce = merge_gid_lists(supplementary_gids, + ngids, + gids_after_pam, + ngids_after_pam, + &gids_to_enforce); + if (ngids_to_enforce < 0) { + *exit_status = EXIT_MEMORY; + return log_unit_error_errno(unit, + ngids_to_enforce, + "Failed to merge group lists. Group membership might be incorrect: %m"); + } + + r = enforce_groups(gid, gids_to_enforce, ngids_to_enforce); + if (r < 0) { + *exit_status = EXIT_GROUP; + return log_unit_error_errno(unit, r, "Changing group credentials failed: %m"); + } + } + + /* If the user namespace was not set up above, try to do it now. + * It's preferred to set up the user namespace later (after all other namespaces) so as not to be + * restricted by rules pertaining to combining user namspaces with other namespaces (e.g. in the + * case of mount namespaces being less privileged when the mount point list is copied from a + * different user namespace). */ + + if (needs_sandboxing && context->private_users && !userns_set_up) { + r = setup_private_users(saved_uid, saved_gid, uid, gid); + if (r < 0) { + *exit_status = EXIT_USER; + return log_unit_error_errno(unit, r, "Failed to set up user namespacing: %m"); + } + } + + /* Now that the mount namespace has been set up and privileges adjusted, let's look for the thing we + * shall execute. */ + + _cleanup_free_ char *executable = NULL; + _cleanup_close_ int executable_fd = -1; + r = find_executable_full(command->path, /* root= */ NULL, context->exec_search_path, false, &executable, &executable_fd); + if (r < 0) { + if (r != -ENOMEM && (command->flags & EXEC_COMMAND_IGNORE_FAILURE)) { + log_unit_struct_errno(unit, LOG_INFO, r, + "MESSAGE_ID=" SD_MESSAGE_SPAWN_FAILED_STR, + LOG_UNIT_INVOCATION_ID(unit), + LOG_UNIT_MESSAGE(unit, "Executable %s missing, skipping: %m", + command->path), + "EXECUTABLE=%s", command->path); + *exit_status = EXIT_SUCCESS; + return 0; + } + + *exit_status = EXIT_EXEC; + return log_unit_struct_errno(unit, LOG_INFO, r, + "MESSAGE_ID=" SD_MESSAGE_SPAWN_FAILED_STR, + LOG_UNIT_INVOCATION_ID(unit), + LOG_UNIT_MESSAGE(unit, "Failed to locate executable %s: %m", + command->path), + "EXECUTABLE=%s", command->path); + } + + r = add_shifted_fd(keep_fds, ELEMENTSOF(keep_fds), &n_keep_fds, executable_fd, &executable_fd); + if (r < 0) { + *exit_status = EXIT_FDS; + return log_unit_error_errno(unit, r, "Failed to shift fd and set FD_CLOEXEC: %m"); + } + +#if HAVE_SELINUX + if (needs_sandboxing && use_selinux && params->selinux_context_net) { + int fd = -1; + + if (socket_fd >= 0) + fd = socket_fd; + else if (params->n_socket_fds == 1) + /* If stdin is not connected to a socket but we are triggered by exactly one socket unit then we + * use context from that fd to compute the label. */ + fd = params->fds[0]; + + if (fd >= 0) { + r = mac_selinux_get_child_mls_label(fd, executable, context->selinux_context, &mac_selinux_context_net); + if (r < 0) { + if (!context->selinux_context_ignore) { + *exit_status = EXIT_SELINUX_CONTEXT; + return log_unit_error_errno(unit, r, "Failed to determine SELinux context: %m"); + } + log_unit_debug_errno(unit, r, "Failed to determine SELinux context, ignoring: %m"); + } + } + } +#endif + + /* We repeat the fd closing here, to make sure that nothing is leaked from the PAM modules. Note that we are + * more aggressive this time since socket_fd and the netns and ipcns fds we don't need anymore. We do keep the exec_fd + * however if we have it as we want to keep it open until the final execve(). */ + + r = close_all_fds(keep_fds, n_keep_fds); + if (r >= 0) + r = shift_fds(fds, n_fds); + if (r >= 0) + r = flag_fds(fds, n_socket_fds, n_storage_fds, context->non_blocking); + if (r < 0) { + *exit_status = EXIT_FDS; + return log_unit_error_errno(unit, r, "Failed to adjust passed file descriptors: %m"); + } + + /* At this point, the fds we want to pass to the program are all ready and set up, with O_CLOEXEC turned off + * and at the right fd numbers. The are no other fds open, with one exception: the exec_fd if it is defined, + * and it has O_CLOEXEC set, after all we want it to be closed by the execve(), so that our parent knows we + * came this far. */ + + secure_bits = context->secure_bits; + + if (needs_sandboxing) { + uint64_t bset; + + /* Set the RTPRIO resource limit to 0, but only if nothing else was explicitly + * requested. (Note this is placed after the general resource limit initialization, see + * above, in order to take precedence.) */ + if (context->restrict_realtime && !context->rlimit[RLIMIT_RTPRIO]) { + if (setrlimit(RLIMIT_RTPRIO, &RLIMIT_MAKE_CONST(0)) < 0) { + *exit_status = EXIT_LIMITS; + return log_unit_error_errno(unit, errno, "Failed to adjust RLIMIT_RTPRIO resource limit: %m"); + } + } + +#if ENABLE_SMACK + /* LSM Smack needs the capability CAP_MAC_ADMIN to change the current execution security context of the + * process. This is the latest place before dropping capabilities. Other MAC context are set later. */ + if (use_smack) { + r = setup_smack(unit->manager, context, executable_fd); + if (r < 0 && !context->smack_process_label_ignore) { + *exit_status = EXIT_SMACK_PROCESS_LABEL; + return log_unit_error_errno(unit, r, "Failed to set SMACK process label: %m"); + } + } +#endif + + bset = context->capability_bounding_set; + /* If the ambient caps hack is enabled (which means the kernel can't do them, and the user asked for + * our magic fallback), then let's add some extra caps, so that the service can drop privs of its own, + * instead of us doing that */ + if (needs_ambient_hack) + bset |= (UINT64_C(1) << CAP_SETPCAP) | + (UINT64_C(1) << CAP_SETUID) | + (UINT64_C(1) << CAP_SETGID); + + if (!cap_test_all(bset)) { + r = capability_bounding_set_drop(bset, false); + if (r < 0) { + *exit_status = EXIT_CAPABILITIES; + return log_unit_error_errno(unit, r, "Failed to drop capabilities: %m"); + } + } + + /* Ambient capabilities are cleared during setresuid() (in enforce_user()) even with + * keep-caps set. + * To be able to raise the ambient capabilities after setresuid() they have to be + * added to the inherited set and keep caps has to be set (done in enforce_user()). + * After setresuid() the ambient capabilities can be raised as they are present in + * the permitted and inhertiable set. However it is possible that someone wants to + * set ambient capabilities without changing the user, so we also set the ambient + * capabilities here. + * The requested ambient capabilities are raised in the inheritable set if the + * second argument is true. */ + if (!needs_ambient_hack) { + r = capability_ambient_set_apply(context->capability_ambient_set, true); + if (r < 0) { + *exit_status = EXIT_CAPABILITIES; + return log_unit_error_errno(unit, r, "Failed to apply ambient capabilities (before UID change): %m"); + } + } + } + + /* chroot to root directory first, before we lose the ability to chroot */ + r = apply_root_directory(context, params, needs_mount_namespace, exit_status); + if (r < 0) + return log_unit_error_errno(unit, r, "Chrooting to the requested root directory failed: %m"); + + if (needs_setuid) { + if (uid_is_valid(uid)) { + r = enforce_user(context, uid); + if (r < 0) { + *exit_status = EXIT_USER; + return log_unit_error_errno(unit, r, "Failed to change UID to " UID_FMT ": %m", uid); + } + + if (!needs_ambient_hack && + context->capability_ambient_set != 0) { + + /* Raise the ambient capabilities after user change. */ + r = capability_ambient_set_apply(context->capability_ambient_set, false); + if (r < 0) { + *exit_status = EXIT_CAPABILITIES; + return log_unit_error_errno(unit, r, "Failed to apply ambient capabilities (after UID change): %m"); + } + } + } + } + + /* Apply working directory here, because the working directory might be on NFS and only the user running + * this service might have the correct privilege to change to the working directory */ + r = apply_working_directory(context, params, home, exit_status); + if (r < 0) + return log_unit_error_errno(unit, r, "Changing to the requested working directory failed: %m"); + + if (needs_sandboxing) { + /* Apply other MAC contexts late, but before seccomp syscall filtering, as those should really be last to + * influence our own codepaths as little as possible. Moreover, applying MAC contexts usually requires + * syscalls that are subject to seccomp filtering, hence should probably be applied before the syscalls + * are restricted. */ + +#if HAVE_SELINUX + if (use_selinux) { + char *exec_context = mac_selinux_context_net ?: context->selinux_context; + + if (exec_context) { + r = setexeccon(exec_context); + if (r < 0) { + if (!context->selinux_context_ignore) { + *exit_status = EXIT_SELINUX_CONTEXT; + return log_unit_error_errno(unit, r, "Failed to change SELinux context to %s: %m", exec_context); + } + log_unit_debug_errno(unit, r, "Failed to change SELinux context to %s, ignoring: %m", exec_context); + } + } + } +#endif + +#if HAVE_APPARMOR + if (use_apparmor && context->apparmor_profile) { + r = aa_change_onexec(context->apparmor_profile); + if (r < 0 && !context->apparmor_profile_ignore) { + *exit_status = EXIT_APPARMOR_PROFILE; + return log_unit_error_errno(unit, errno, "Failed to prepare AppArmor profile change to %s: %m", context->apparmor_profile); + } + } +#endif + + /* 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. Setting securebits requires + * CAP_SETPCAP. */ + if (prctl(PR_GET_SECUREBITS) != secure_bits) { + /* CAP_SETPCAP is required to set securebits. This capability is raised into the + * effective set here. + * The effective set is overwritten during execve with the following values: + * - ambient set (for non-root processes) + * - (inheritable | bounding) set for root processes) + * + * Hence there is no security impact to raise it in the effective set before execve + */ + r = capability_gain_cap_setpcap(NULL); + if (r < 0) { + *exit_status = EXIT_CAPABILITIES; + return log_unit_error_errno(unit, r, "Failed to gain CAP_SETPCAP for setting secure bits"); + } + if (prctl(PR_SET_SECUREBITS, secure_bits) < 0) { + *exit_status = EXIT_SECUREBITS; + return log_unit_error_errno(unit, errno, "Failed to set process secure bits: %m"); + } + } + + if (context_has_no_new_privileges(context)) + if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) < 0) { + *exit_status = EXIT_NO_NEW_PRIVILEGES; + return log_unit_error_errno(unit, errno, "Failed to disable new privileges: %m"); + } + +#if HAVE_SECCOMP + r = apply_address_families(unit, context); + if (r < 0) { + *exit_status = EXIT_ADDRESS_FAMILIES; + return log_unit_error_errno(unit, r, "Failed to restrict address families: %m"); + } + + r = apply_memory_deny_write_execute(unit, context); + if (r < 0) { + *exit_status = EXIT_SECCOMP; + return log_unit_error_errno(unit, r, "Failed to disable writing to executable memory: %m"); + } + + r = apply_restrict_realtime(unit, context); + if (r < 0) { + *exit_status = EXIT_SECCOMP; + return log_unit_error_errno(unit, r, "Failed to apply realtime restrictions: %m"); + } + + r = apply_restrict_suid_sgid(unit, context); + if (r < 0) { + *exit_status = EXIT_SECCOMP; + return log_unit_error_errno(unit, r, "Failed to apply SUID/SGID restrictions: %m"); + } + + r = apply_restrict_namespaces(unit, context); + if (r < 0) { + *exit_status = EXIT_SECCOMP; + return log_unit_error_errno(unit, r, "Failed to apply namespace restrictions: %m"); + } + + r = apply_protect_sysctl(unit, context); + if (r < 0) { + *exit_status = EXIT_SECCOMP; + return log_unit_error_errno(unit, r, "Failed to apply sysctl restrictions: %m"); + } + + r = apply_protect_kernel_modules(unit, context); + if (r < 0) { + *exit_status = EXIT_SECCOMP; + return log_unit_error_errno(unit, r, "Failed to apply module loading restrictions: %m"); + } + + r = apply_protect_kernel_logs(unit, context); + if (r < 0) { + *exit_status = EXIT_SECCOMP; + return log_unit_error_errno(unit, r, "Failed to apply kernel log restrictions: %m"); + } + + r = apply_protect_clock(unit, context); + if (r < 0) { + *exit_status = EXIT_SECCOMP; + return log_unit_error_errno(unit, r, "Failed to apply clock restrictions: %m"); + } + + r = apply_private_devices(unit, context); + if (r < 0) { + *exit_status = EXIT_SECCOMP; + return log_unit_error_errno(unit, r, "Failed to set up private devices: %m"); + } + + r = apply_syscall_archs(unit, context); + if (r < 0) { + *exit_status = EXIT_SECCOMP; + return log_unit_error_errno(unit, r, "Failed to apply syscall architecture restrictions: %m"); + } + + r = apply_lock_personality(unit, context); + if (r < 0) { + *exit_status = EXIT_SECCOMP; + return log_unit_error_errno(unit, r, "Failed to lock personalities: %m"); + } + + r = apply_syscall_log(unit, context); + if (r < 0) { + *exit_status = EXIT_SECCOMP; + return log_unit_error_errno(unit, r, "Failed to apply system call log filters: %m"); + } + + /* This really should remain the last step before the execve(), to make sure our own code is unaffected + * by the filter as little as possible. */ + r = apply_syscall_filter(unit, context, needs_ambient_hack); + if (r < 0) { + *exit_status = EXIT_SECCOMP; + return log_unit_error_errno(unit, r, "Failed to apply system call filters: %m"); + } +#endif + +#if HAVE_LIBBPF + r = apply_restrict_filesystems(unit, context); + if (r < 0) { + *exit_status = EXIT_BPF; + return log_unit_error_errno(unit, r, "Failed to restrict filesystems: %m"); + } +#endif + + } + + if (!strv_isempty(context->unset_environment)) { + char **ee = NULL; + + ee = strv_env_delete(accum_env, 1, context->unset_environment); + if (!ee) { + *exit_status = EXIT_MEMORY; + return log_oom(); + } + + strv_free_and_replace(accum_env, ee); + } + + if (!FLAGS_SET(command->flags, EXEC_COMMAND_NO_ENV_EXPAND)) { + replaced_argv = replace_env_argv(command->argv, accum_env); + if (!replaced_argv) { + *exit_status = EXIT_MEMORY; + return log_oom(); + } + final_argv = replaced_argv; + } else + final_argv = command->argv; + + if (DEBUG_LOGGING) { + _cleanup_free_ char *line = NULL; + + line = quote_command_line(final_argv, SHELL_ESCAPE_EMPTY); + if (!line) { + *exit_status = EXIT_MEMORY; + return log_oom(); + } + + log_unit_struct(unit, LOG_DEBUG, + "EXECUTABLE=%s", executable, + LOG_UNIT_MESSAGE(unit, "Executing: %s", line)); + } + + if (exec_fd >= 0) { + uint8_t hot = 1; + + /* We have finished with all our initializations. Let's now let the manager know that. From this point + * on, if the manager sees POLLHUP on the exec_fd, then execve() was successful. */ + + if (write(exec_fd, &hot, sizeof(hot)) < 0) { + *exit_status = EXIT_EXEC; + return log_unit_error_errno(unit, errno, "Failed to enable exec_fd: %m"); + } + } + + r = fexecve_or_execve(executable_fd, executable, final_argv, accum_env); + + if (exec_fd >= 0) { + uint8_t hot = 0; + + /* The execve() failed. This means the exec_fd is still open. Which means we need to tell the manager + * that POLLHUP on it no longer means execve() succeeded. */ + + if (write(exec_fd, &hot, sizeof(hot)) < 0) { + *exit_status = EXIT_EXEC; + return log_unit_error_errno(unit, errno, "Failed to disable exec_fd: %m"); + } + } + + *exit_status = EXIT_EXEC; + return log_unit_error_errno(unit, r, "Failed to execute %s: %m", executable); +} + +static int exec_context_load_environment(const Unit *unit, const ExecContext *c, char ***l); +static int exec_context_named_iofds(const ExecContext *c, const ExecParameters *p, int named_iofds[static 3]); + +int exec_spawn(Unit *unit, + ExecCommand *command, + const ExecContext *context, + const ExecParameters *params, + ExecRuntime *runtime, + DynamicCreds *dcreds, + pid_t *ret) { + + int socket_fd, r, named_iofds[3] = { -1, -1, -1 }, *fds = NULL; + _cleanup_free_ char *subcgroup_path = NULL; + _cleanup_strv_free_ char **files_env = NULL; + size_t n_storage_fds = 0, n_socket_fds = 0; + _cleanup_free_ char *line = NULL; + pid_t pid; + + assert(unit); + assert(command); + assert(context); + assert(ret); + assert(params); + assert(params->fds || (params->n_socket_fds + params->n_storage_fds <= 0)); + + if (context->std_input == EXEC_INPUT_SOCKET || + context->std_output == EXEC_OUTPUT_SOCKET || + context->std_error == EXEC_OUTPUT_SOCKET) { + + if (params->n_socket_fds > 1) + return log_unit_error_errno(unit, SYNTHETIC_ERRNO(EINVAL), "Got more than one socket."); + + if (params->n_socket_fds == 0) + return log_unit_error_errno(unit, SYNTHETIC_ERRNO(EINVAL), "Got no socket."); + + socket_fd = params->fds[0]; + } else { + socket_fd = -1; + fds = params->fds; + n_socket_fds = params->n_socket_fds; + n_storage_fds = params->n_storage_fds; + } + + r = exec_context_named_iofds(context, params, named_iofds); + if (r < 0) + return log_unit_error_errno(unit, r, "Failed to load a named file descriptor: %m"); + + r = exec_context_load_environment(unit, context, &files_env); + if (r < 0) + return log_unit_error_errno(unit, r, "Failed to load environment files: %m"); + + line = quote_command_line(command->argv, SHELL_ESCAPE_EMPTY); + if (!line) + return log_oom(); + + /* Fork with up-to-date SELinux label database, so the child inherits the up-to-date db + and, until the next SELinux policy changes, we save further reloads in future children. */ + mac_selinux_maybe_reload(); + + log_unit_struct(unit, LOG_DEBUG, + LOG_UNIT_MESSAGE(unit, "About to execute %s", line), + "EXECUTABLE=%s", command->path, /* We won't know the real executable path until we create + the mount namespace in the child, but we want to log + from the parent, so we need to use the (possibly + inaccurate) path here. */ + LOG_UNIT_INVOCATION_ID(unit)); + + if (params->cgroup_path) { + r = exec_parameters_get_cgroup_path(params, &subcgroup_path); + if (r < 0) + return log_unit_error_errno(unit, r, "Failed to acquire subcgroup path: %m"); + if (r > 0) { /* We are using a child cgroup */ + r = cg_create(SYSTEMD_CGROUP_CONTROLLER, subcgroup_path); + if (r < 0) + return log_unit_error_errno(unit, r, "Failed to create control group '%s': %m", subcgroup_path); + + /* Normally we would not propagate the oomd xattrs to children but since we created this + * sub-cgroup internally we should do it. */ + cgroup_oomd_xattr_apply(unit, subcgroup_path); + } + } + + pid = fork(); + if (pid < 0) + return log_unit_error_errno(unit, errno, "Failed to fork: %m"); + + if (pid == 0) { + int exit_status; + + r = exec_child(unit, + command, + context, + params, + runtime, + dcreds, + socket_fd, + named_iofds, + fds, + n_socket_fds, + n_storage_fds, + files_env, + unit->manager->user_lookup_fds[1], + &exit_status); + + if (r < 0) { + const char *status = ASSERT_PTR( + exit_status_to_string(exit_status, EXIT_STATUS_LIBC | EXIT_STATUS_SYSTEMD)); + + log_unit_struct_errno(unit, LOG_ERR, r, + "MESSAGE_ID=" SD_MESSAGE_SPAWN_FAILED_STR, + LOG_UNIT_INVOCATION_ID(unit), + LOG_UNIT_MESSAGE(unit, "Failed at step %s spawning %s: %m", + status, command->path), + "EXECUTABLE=%s", command->path); + } else + assert(exit_status == EXIT_SUCCESS); + + _exit(exit_status); + } + + log_unit_debug(unit, "Forked %s as "PID_FMT, command->path, pid); + + /* 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 (subcgroup_path) + (void) cg_attach(SYSTEMD_CGROUP_CONTROLLER, subcgroup_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_DEFAULT_CLASS_AND_PRIO; + 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_INFINITY; + c->personality = PERSONALITY_INVALID; + for (ExecDirectoryType t = 0; t < _EXEC_DIRECTORY_TYPE_MAX; t++) + c->directories[t].mode = 0755; + c->timeout_clean_usec = USEC_INFINITY; + c->capability_bounding_set = CAP_ALL; + assert_cc(NAMESPACE_FLAGS_INITIAL != NAMESPACE_FLAGS_ALL); + c->restrict_namespaces = NAMESPACE_FLAGS_INITIAL; + c->log_level_max = -1; +#if HAVE_SECCOMP + c->syscall_errno = SECCOMP_ERROR_NUMBER_KILL; +#endif + c->tty_rows = UINT_MAX; + c->tty_cols = UINT_MAX; + numa_policy_reset(&c->numa_policy); +} + +void exec_context_done(ExecContext *c) { + assert(c); + + c->environment = strv_free(c->environment); + c->environment_files = strv_free(c->environment_files); + c->pass_environment = strv_free(c->pass_environment); + c->unset_environment = strv_free(c->unset_environment); + + rlimit_free_all(c->rlimit); + + for (size_t l = 0; l < 3; l++) { + c->stdio_fdname[l] = mfree(c->stdio_fdname[l]); + c->stdio_file[l] = mfree(c->stdio_file[l]); + } + + c->working_directory = mfree(c->working_directory); + c->root_directory = mfree(c->root_directory); + c->root_image = mfree(c->root_image); + c->root_image_options = mount_options_free_all(c->root_image_options); + c->root_hash = mfree(c->root_hash); + c->root_hash_size = 0; + c->root_hash_path = mfree(c->root_hash_path); + c->root_hash_sig = mfree(c->root_hash_sig); + c->root_hash_sig_size = 0; + c->root_hash_sig_path = mfree(c->root_hash_sig_path); + c->root_verity = mfree(c->root_verity); + c->extension_images = mount_image_free_many(c->extension_images, &c->n_extension_images); + c->extension_directories = strv_free(c->extension_directories); + c->tty_path = mfree(c->tty_path); + c->syslog_identifier = mfree(c->syslog_identifier); + c->user = mfree(c->user); + c->group = mfree(c->group); + + c->supplementary_groups = strv_free(c->supplementary_groups); + + c->pam_name = mfree(c->pam_name); + + c->read_only_paths = strv_free(c->read_only_paths); + c->read_write_paths = strv_free(c->read_write_paths); + c->inaccessible_paths = strv_free(c->inaccessible_paths); + c->exec_paths = strv_free(c->exec_paths); + c->no_exec_paths = strv_free(c->no_exec_paths); + c->exec_search_path = strv_free(c->exec_search_path); + + bind_mount_free_many(c->bind_mounts, c->n_bind_mounts); + c->bind_mounts = NULL; + c->n_bind_mounts = 0; + temporary_filesystem_free_many(c->temporary_filesystems, c->n_temporary_filesystems); + c->temporary_filesystems = NULL; + c->n_temporary_filesystems = 0; + c->mount_images = mount_image_free_many(c->mount_images, &c->n_mount_images); + + cpu_set_reset(&c->cpu_set); + numa_policy_reset(&c->numa_policy); + + c->utmp_id = mfree(c->utmp_id); + c->selinux_context = mfree(c->selinux_context); + c->apparmor_profile = mfree(c->apparmor_profile); + c->smack_process_label = mfree(c->smack_process_label); + + c->restrict_filesystems = set_free_free(c->restrict_filesystems); + + c->syscall_filter = hashmap_free(c->syscall_filter); + c->syscall_archs = set_free(c->syscall_archs); + c->address_families = set_free(c->address_families); + + for (ExecDirectoryType t = 0; t < _EXEC_DIRECTORY_TYPE_MAX; t++) + exec_directory_done(&c->directories[t]); + + c->log_level_max = -1; + + exec_context_free_log_extra_fields(c); + + c->log_ratelimit_interval_usec = 0; + c->log_ratelimit_burst = 0; + + c->stdin_data = mfree(c->stdin_data); + c->stdin_data_size = 0; + + c->network_namespace_path = mfree(c->network_namespace_path); + c->ipc_namespace_path = mfree(c->ipc_namespace_path); + + c->log_namespace = mfree(c->log_namespace); + + c->load_credentials = hashmap_free(c->load_credentials); + c->set_credentials = hashmap_free(c->set_credentials); +} + +int exec_context_destroy_runtime_directory(const ExecContext *c, const char *runtime_prefix) { + assert(c); + + if (!runtime_prefix) + return 0; + + for (size_t i = 0; i < c->directories[EXEC_DIRECTORY_RUNTIME].n_items; i++) { + _cleanup_free_ char *p = NULL; + + if (exec_directory_is_private(c, EXEC_DIRECTORY_RUNTIME)) + p = path_join(runtime_prefix, "private", c->directories[EXEC_DIRECTORY_RUNTIME].items[i].path); + else + p = path_join(runtime_prefix, c->directories[EXEC_DIRECTORY_RUNTIME].items[i].path); + if (!p) + return -ENOMEM; + + /* We execute this synchronously, since we need to be sure this is gone when we start the + * service next. */ + (void) rm_rf(p, REMOVE_ROOT); + + STRV_FOREACH(symlink, c->directories[EXEC_DIRECTORY_RUNTIME].items[i].symlinks) { + _cleanup_free_ char *symlink_abs = NULL; + + if (exec_directory_is_private(c, EXEC_DIRECTORY_RUNTIME)) + symlink_abs = path_join(runtime_prefix, "private", *symlink); + else + symlink_abs = path_join(runtime_prefix, *symlink); + if (!symlink_abs) + return -ENOMEM; + + (void) unlink(symlink_abs); + } + + } + + return 0; +} + +int exec_context_destroy_credentials(const ExecContext *c, const char *runtime_prefix, const char *unit) { + _cleanup_free_ char *p = NULL; + + assert(c); + + if (!runtime_prefix || !unit) + return 0; + + p = path_join(runtime_prefix, "credentials", unit); + if (!p) + return -ENOMEM; + + /* This is either a tmpfs/ramfs of its own, or a plain directory. Either way, let's first try to + * unmount it, and afterwards remove the mount point */ + (void) umount2(p, MNT_DETACH|UMOUNT_NOFOLLOW); + (void) rm_rf(p, REMOVE_ROOT|REMOVE_CHMOD); + + return 0; +} + +int exec_context_destroy_mount_ns_dir(Unit *u) { + _cleanup_free_ char *p = NULL; + + if (!u || !MANAGER_IS_SYSTEM(u->manager)) + return 0; + + p = path_join("/run/systemd/propagate/", u->id); + if (!p) + return -ENOMEM; + + /* This is only filled transiently (see mount_in_namespace()), should be empty or even non-existent*/ + if (rmdir(p) < 0 && errno != ENOENT) + log_unit_debug_errno(u, errno, "Unable to remove propagation dir '%s', ignoring: %m", p); + + return 0; +} + +static void exec_command_done(ExecCommand *c) { + assert(c); + + c->path = mfree(c->path); + c->argv = strv_free(c->argv); +} + +void exec_command_done_array(ExecCommand *c, size_t n) { + for (size_t i = 0; i < n; i++) + exec_command_done(c+i); +} + +ExecCommand* exec_command_free_list(ExecCommand *c) { + ExecCommand *i; + + while ((i = c)) { + LIST_REMOVE(command, c, i); + exec_command_done(i); + free(i); + } + + return NULL; +} + +void exec_command_free_array(ExecCommand **c, size_t n) { + for (size_t i = 0; i < n; i++) + c[i] = exec_command_free_list(c[i]); +} + +void exec_command_reset_status_array(ExecCommand *c, size_t n) { + for (size_t i = 0; i < n; i++) + exec_status_reset(&c[i].exec_status); +} + +void exec_command_reset_status_list_array(ExecCommand **c, size_t n) { + for (size_t i = 0; i < n; i++) + LIST_FOREACH(command, z, c[i]) + exec_status_reset(&z->exec_status); +} + +typedef struct InvalidEnvInfo { + const Unit *unit; + const char *path; +} InvalidEnvInfo; + +static void invalid_env(const char *p, void *userdata) { + InvalidEnvInfo *info = userdata; + + log_unit_error(info->unit, "Ignoring invalid environment assignment '%s': %s", p, info->path); +} + +const char* exec_context_fdname(const ExecContext *c, int fd_index) { + assert(c); + + switch (fd_index) { + + case STDIN_FILENO: + if (c->std_input != EXEC_INPUT_NAMED_FD) + return NULL; + + return c->stdio_fdname[STDIN_FILENO] ?: "stdin"; + + case STDOUT_FILENO: + if (c->std_output != EXEC_OUTPUT_NAMED_FD) + return NULL; + + return c->stdio_fdname[STDOUT_FILENO] ?: "stdout"; + + case STDERR_FILENO: + if (c->std_error != EXEC_OUTPUT_NAMED_FD) + return NULL; + + return c->stdio_fdname[STDERR_FILENO] ?: "stderr"; + + default: + return NULL; + } +} + +static int exec_context_named_iofds( + const ExecContext *c, + const ExecParameters *p, + int named_iofds[static 3]) { + + size_t targets; + const char* stdio_fdname[3]; + size_t n_fds; + + assert(c); + assert(p); + assert(named_iofds); + + targets = (c->std_input == EXEC_INPUT_NAMED_FD) + + (c->std_output == EXEC_OUTPUT_NAMED_FD) + + (c->std_error == EXEC_OUTPUT_NAMED_FD); + + for (size_t i = 0; i < 3; i++) + stdio_fdname[i] = exec_context_fdname(c, i); + + n_fds = p->n_storage_fds + p->n_socket_fds; + + for (size_t i = 0; i < n_fds && targets > 0; i++) + if (named_iofds[STDIN_FILENO] < 0 && + c->std_input == EXEC_INPUT_NAMED_FD && + stdio_fdname[STDIN_FILENO] && + streq(p->fd_names[i], stdio_fdname[STDIN_FILENO])) { + + named_iofds[STDIN_FILENO] = p->fds[i]; + targets--; + + } else if (named_iofds[STDOUT_FILENO] < 0 && + c->std_output == EXEC_OUTPUT_NAMED_FD && + stdio_fdname[STDOUT_FILENO] && + streq(p->fd_names[i], stdio_fdname[STDOUT_FILENO])) { + + named_iofds[STDOUT_FILENO] = p->fds[i]; + targets--; + + } else if (named_iofds[STDERR_FILENO] < 0 && + c->std_error == EXEC_OUTPUT_NAMED_FD && + stdio_fdname[STDERR_FILENO] && + streq(p->fd_names[i], stdio_fdname[STDERR_FILENO])) { + + named_iofds[STDERR_FILENO] = p->fds[i]; + targets--; + } + + return targets == 0 ? 0 : -ENOENT; +} + +static int exec_context_load_environment(const Unit *unit, const ExecContext *c, char ***ret) { + _cleanup_strv_free_ char **v = NULL; + int r; + + assert(c); + assert(ret); + + STRV_FOREACH(i, c->environment_files) { + _cleanup_globfree_ glob_t pglob = {}; + bool ignore = false; + char *fn = *i; + + if (fn[0] == '-') { + ignore = true; + fn++; + } + + if (!path_is_absolute(fn)) { + if (ignore) + continue; + return -EINVAL; + } + + /* Filename supports globbing, take all matching files */ + r = safe_glob(fn, 0, &pglob); + if (r < 0) { + if (ignore) + continue; + return r; + } + + /* When we don't match anything, -ENOENT should be returned */ + assert(pglob.gl_pathc > 0); + + for (unsigned n = 0; n < pglob.gl_pathc; n++) { + _cleanup_strv_free_ char **p = NULL; + + r = load_env_file(NULL, pglob.gl_pathv[n], &p); + if (r < 0) { + if (ignore) + continue; + return r; + } + + /* Log invalid environment variables with filename */ + if (p) { + InvalidEnvInfo info = { + .unit = unit, + .path = pglob.gl_pathv[n] + }; + + p = strv_env_clean_with_callback(p, invalid_env, &info); + } + + if (!v) + v = TAKE_PTR(p); + else { + char **m = strv_env_merge(v, p); + if (!m) + return -ENOMEM; + + strv_free_and_replace(v, m); + } + } + } + + *ret = TAKE_PTR(v); + + return 0; +} + +static bool tty_may_match_dev_console(const char *tty) { + _cleanup_free_ char *resolved = NULL; + + if (!tty) + return true; + + tty = skip_dev_prefix(tty); + + /* trivial identity? */ + if (streq(tty, "console")) + return true; + + if (resolve_dev_console(&resolved) < 0) + return true; /* if we could not resolve, assume it may */ + + /* "tty0" means the active VC, so it may be the same sometimes */ + return path_equal(resolved, tty) || (streq(resolved, "tty0") && tty_is_vc(tty)); +} + +static bool exec_context_may_touch_tty(const ExecContext *ec) { + assert(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); +} + +bool exec_context_may_touch_console(const ExecContext *ec) { + + return exec_context_may_touch_tty(ec) && + tty_may_match_dev_console(exec_context_tty_path(ec)); +} + +static void strv_fprintf(FILE *f, char **l) { + assert(f); + + STRV_FOREACH(g, l) + fprintf(f, " %s", *g); +} + +static void strv_dump(FILE* f, const char *prefix, const char *name, char **strv) { + assert(f); + assert(prefix); + assert(name); + + if (!strv_isempty(strv)) { + fprintf(f, "%s%s:", prefix, name); + strv_fprintf(f, strv); + fputs("\n", f); + } +} + +void exec_context_dump(const ExecContext *c, FILE* f, const char *prefix) { + int r; + + assert(c); + assert(f); + + prefix = strempty(prefix); + + fprintf(f, + "%sUMask: %04o\n" + "%sWorkingDirectory: %s\n" + "%sRootDirectory: %s\n" + "%sNonBlocking: %s\n" + "%sPrivateTmp: %s\n" + "%sPrivateDevices: %s\n" + "%sProtectKernelTunables: %s\n" + "%sProtectKernelModules: %s\n" + "%sProtectKernelLogs: %s\n" + "%sProtectClock: %s\n" + "%sProtectControlGroups: %s\n" + "%sPrivateNetwork: %s\n" + "%sPrivateUsers: %s\n" + "%sProtectHome: %s\n" + "%sProtectSystem: %s\n" + "%sMountAPIVFS: %s\n" + "%sIgnoreSIGPIPE: %s\n" + "%sMemoryDenyWriteExecute: %s\n" + "%sRestrictRealtime: %s\n" + "%sRestrictSUIDSGID: %s\n" + "%sKeyringMode: %s\n" + "%sProtectHostname: %s\n" + "%sProtectProc: %s\n" + "%sProcSubset: %s\n", + prefix, c->umask, + prefix, empty_to_root(c->working_directory), + prefix, empty_to_root(c->root_directory), + prefix, yes_no(c->non_blocking), + prefix, yes_no(c->private_tmp), + prefix, yes_no(c->private_devices), + prefix, yes_no(c->protect_kernel_tunables), + prefix, yes_no(c->protect_kernel_modules), + prefix, yes_no(c->protect_kernel_logs), + prefix, yes_no(c->protect_clock), + prefix, yes_no(c->protect_control_groups), + prefix, yes_no(c->private_network), + prefix, yes_no(c->private_users), + prefix, protect_home_to_string(c->protect_home), + prefix, protect_system_to_string(c->protect_system), + prefix, yes_no(exec_context_get_effective_mount_apivfs(c)), + prefix, yes_no(c->ignore_sigpipe), + prefix, yes_no(c->memory_deny_write_execute), + prefix, yes_no(c->restrict_realtime), + prefix, yes_no(c->restrict_suid_sgid), + prefix, exec_keyring_mode_to_string(c->keyring_mode), + prefix, yes_no(c->protect_hostname), + prefix, protect_proc_to_string(c->protect_proc), + prefix, proc_subset_to_string(c->proc_subset)); + + if (c->root_image) + fprintf(f, "%sRootImage: %s\n", prefix, c->root_image); + + if (c->root_image_options) { + fprintf(f, "%sRootImageOptions:", prefix); + LIST_FOREACH(mount_options, o, c->root_image_options) + if (!isempty(o->options)) + fprintf(f, " %s:%s", + partition_designator_to_string(o->partition_designator), + o->options); + fprintf(f, "\n"); + } + + if (c->root_hash) { + _cleanup_free_ char *encoded = NULL; + encoded = hexmem(c->root_hash, c->root_hash_size); + if (encoded) + fprintf(f, "%sRootHash: %s\n", prefix, encoded); + } + + if (c->root_hash_path) + fprintf(f, "%sRootHash: %s\n", prefix, c->root_hash_path); + + if (c->root_hash_sig) { + _cleanup_free_ char *encoded = NULL; + ssize_t len; + len = base64mem(c->root_hash_sig, c->root_hash_sig_size, &encoded); + if (len) + fprintf(f, "%sRootHashSignature: base64:%s\n", prefix, encoded); + } + + if (c->root_hash_sig_path) + fprintf(f, "%sRootHashSignature: %s\n", prefix, c->root_hash_sig_path); + + if (c->root_verity) + fprintf(f, "%sRootVerity: %s\n", prefix, c->root_verity); + + 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); + + STRV_FOREACH(e, c->pass_environment) + fprintf(f, "%sPassEnvironment: %s\n", prefix, *e); + + STRV_FOREACH(e, c->unset_environment) + fprintf(f, "%sUnsetEnvironment: %s\n", prefix, *e); + + fprintf(f, "%sRuntimeDirectoryPreserve: %s\n", prefix, exec_preserve_mode_to_string(c->runtime_directory_preserve_mode)); + + for (ExecDirectoryType dt = 0; dt < _EXEC_DIRECTORY_TYPE_MAX; dt++) { + fprintf(f, "%s%sMode: %04o\n", prefix, exec_directory_type_to_string(dt), c->directories[dt].mode); + + for (size_t i = 0; i < c->directories[dt].n_items; i++) { + fprintf(f, "%s%s: %s\n", prefix, exec_directory_type_to_string(dt), c->directories[dt].items[i].path); + + STRV_FOREACH(d, c->directories[dt].items[i].symlinks) + fprintf(f, "%s%s: %s:%s\n", prefix, exec_directory_type_symlink_to_string(dt), c->directories[dt].items[i].path, *d); + } + } + + fprintf(f, "%sTimeoutCleanSec: %s\n", prefix, FORMAT_TIMESPAN(c->timeout_clean_usec, USEC_PER_SEC)); + + 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); + + if (c->coredump_filter_set) + fprintf(f, "%sCoredumpFilter: 0x%"PRIx64"\n", prefix, c->coredump_filter); + + for (unsigned i = 0; i < RLIM_NLIMITS; i++) + if (c->rlimit[i]) { + fprintf(f, "%sLimit%s: " RLIM_FMT "\n", + prefix, rlimit_to_string(i), c->rlimit[i]->rlim_max); + fprintf(f, "%sLimit%sSoft: " RLIM_FMT "\n", + prefix, rlimit_to_string(i), c->rlimit[i]->rlim_cur); + } + + if (c->ioprio_set) { + _cleanup_free_ char *class_str = NULL; + + r = ioprio_class_to_string_alloc(ioprio_prio_class(c->ioprio), &class_str); + if (r >= 0) + fprintf(f, "%sIOSchedulingClass: %s\n", prefix, class_str); + + fprintf(f, "%sIOPriority: %d\n", prefix, ioprio_prio_data(c->ioprio)); + } + + if (c->cpu_sched_set) { + _cleanup_free_ char *policy_str = NULL; + + r = sched_policy_to_string_alloc(c->cpu_sched_policy, &policy_str); + if (r >= 0) + fprintf(f, "%sCPUSchedulingPolicy: %s\n", prefix, policy_str); + + fprintf(f, + "%sCPUSchedulingPriority: %i\n" + "%sCPUSchedulingResetOnFork: %s\n", + prefix, c->cpu_sched_priority, + prefix, yes_no(c->cpu_sched_reset_on_fork)); + } + + if (c->cpu_set.set) { + _cleanup_free_ char *affinity = NULL; + + affinity = cpu_set_to_range_string(&c->cpu_set); + fprintf(f, "%sCPUAffinity: %s\n", prefix, affinity); + } + + if (mpol_is_valid(numa_policy_get_type(&c->numa_policy))) { + _cleanup_free_ char *nodes = NULL; + + nodes = cpu_set_to_range_string(&c->numa_policy.nodes); + fprintf(f, "%sNUMAPolicy: %s\n", prefix, mpol_to_string(numa_policy_get_type(&c->numa_policy))); + fprintf(f, "%sNUMAMask: %s\n", prefix, strnull(nodes)); + } + + if (c->timer_slack_nsec != NSEC_INFINITY) + fprintf(f, "%sTimerSlackNSec: "NSEC_FMT "\n", prefix, 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->std_input == EXEC_INPUT_NAMED_FD) + fprintf(f, "%sStandardInputFileDescriptorName: %s\n", prefix, c->stdio_fdname[STDIN_FILENO]); + if (c->std_output == EXEC_OUTPUT_NAMED_FD) + fprintf(f, "%sStandardOutputFileDescriptorName: %s\n", prefix, c->stdio_fdname[STDOUT_FILENO]); + if (c->std_error == EXEC_OUTPUT_NAMED_FD) + fprintf(f, "%sStandardErrorFileDescriptorName: %s\n", prefix, c->stdio_fdname[STDERR_FILENO]); + + if (c->std_input == EXEC_INPUT_FILE) + fprintf(f, "%sStandardInputFile: %s\n", prefix, c->stdio_file[STDIN_FILENO]); + if (c->std_output == EXEC_OUTPUT_FILE) + fprintf(f, "%sStandardOutputFile: %s\n", prefix, c->stdio_file[STDOUT_FILENO]); + if (c->std_output == EXEC_OUTPUT_FILE_APPEND) + fprintf(f, "%sStandardOutputFileToAppend: %s\n", prefix, c->stdio_file[STDOUT_FILENO]); + if (c->std_output == EXEC_OUTPUT_FILE_TRUNCATE) + fprintf(f, "%sStandardOutputFileToTruncate: %s\n", prefix, c->stdio_file[STDOUT_FILENO]); + if (c->std_error == EXEC_OUTPUT_FILE) + fprintf(f, "%sStandardErrorFile: %s\n", prefix, c->stdio_file[STDERR_FILENO]); + if (c->std_error == EXEC_OUTPUT_FILE_APPEND) + fprintf(f, "%sStandardErrorFileToAppend: %s\n", prefix, c->stdio_file[STDERR_FILENO]); + if (c->std_error == EXEC_OUTPUT_FILE_TRUNCATE) + fprintf(f, "%sStandardErrorFileToTruncate: %s\n", prefix, c->stdio_file[STDERR_FILENO]); + + if (c->tty_path) + fprintf(f, + "%sTTYPath: %s\n" + "%sTTYReset: %s\n" + "%sTTYVHangup: %s\n" + "%sTTYVTDisallocate: %s\n" + "%sTTYRows: %u\n" + "%sTTYColumns: %u\n", + prefix, c->tty_path, + prefix, yes_no(c->tty_reset), + prefix, yes_no(c->tty_vhangup), + prefix, yes_no(c->tty_vt_disallocate), + prefix, c->tty_rows, + prefix, c->tty_cols); + + if (IN_SET(c->std_output, + EXEC_OUTPUT_KMSG, + EXEC_OUTPUT_JOURNAL, + EXEC_OUTPUT_KMSG_AND_CONSOLE, + EXEC_OUTPUT_JOURNAL_AND_CONSOLE) || + IN_SET(c->std_error, + EXEC_OUTPUT_KMSG, + EXEC_OUTPUT_JOURNAL, + EXEC_OUTPUT_KMSG_AND_CONSOLE, + EXEC_OUTPUT_JOURNAL_AND_CONSOLE)) { + + _cleanup_free_ char *fac_str = NULL, *lvl_str = NULL; + + r = log_facility_unshifted_to_string_alloc(c->syslog_priority >> 3, &fac_str); + if (r >= 0) + fprintf(f, "%sSyslogFacility: %s\n", prefix, fac_str); + + r = log_level_to_string_alloc(LOG_PRI(c->syslog_priority), &lvl_str); + if (r >= 0) + fprintf(f, "%sSyslogLevel: %s\n", prefix, lvl_str); + } + + if (c->log_level_max >= 0) { + _cleanup_free_ char *t = NULL; + + (void) log_level_to_string_alloc(c->log_level_max, &t); + + fprintf(f, "%sLogLevelMax: %s\n", prefix, strna(t)); + } + + if (c->log_ratelimit_interval_usec > 0) + fprintf(f, + "%sLogRateLimitIntervalSec: %s\n", + prefix, FORMAT_TIMESPAN(c->log_ratelimit_interval_usec, USEC_PER_SEC)); + + if (c->log_ratelimit_burst > 0) + fprintf(f, "%sLogRateLimitBurst: %u\n", prefix, c->log_ratelimit_burst); + + for (size_t j = 0; j < c->n_log_extra_fields; j++) { + fprintf(f, "%sLogExtraFields: ", prefix); + fwrite(c->log_extra_fields[j].iov_base, + 1, c->log_extra_fields[j].iov_len, + f); + fputc('\n', f); + } + + if (c->log_namespace) + fprintf(f, "%sLogNamespace: %s\n", prefix, c->log_namespace); + + if (c->secure_bits) { + _cleanup_free_ char *str = NULL; + + r = secure_bits_to_string_alloc(c->secure_bits, &str); + if (r >= 0) + fprintf(f, "%sSecure Bits: %s\n", prefix, str); + } + + if (c->capability_bounding_set != CAP_ALL) { + _cleanup_free_ char *str = NULL; + + r = capability_set_to_string_alloc(c->capability_bounding_set, &str); + if (r >= 0) + fprintf(f, "%sCapabilityBoundingSet: %s\n", prefix, str); + } + + if (c->capability_ambient_set != 0) { + _cleanup_free_ char *str = NULL; + + r = capability_set_to_string_alloc(c->capability_ambient_set, &str); + if (r >= 0) + fprintf(f, "%sAmbientCapabilities: %s\n", prefix, str); + } + + if (c->user) + fprintf(f, "%sUser: %s\n", prefix, c->user); + if (c->group) + fprintf(f, "%sGroup: %s\n", prefix, c->group); + + fprintf(f, "%sDynamicUser: %s\n", prefix, yes_no(c->dynamic_user)); + + strv_dump(f, prefix, "SupplementaryGroups", c->supplementary_groups); + + if (c->pam_name) + fprintf(f, "%sPAMName: %s\n", prefix, c->pam_name); + + strv_dump(f, prefix, "ReadWritePaths", c->read_write_paths); + strv_dump(f, prefix, "ReadOnlyPaths", c->read_only_paths); + strv_dump(f, prefix, "InaccessiblePaths", c->inaccessible_paths); + strv_dump(f, prefix, "ExecPaths", c->exec_paths); + strv_dump(f, prefix, "NoExecPaths", c->no_exec_paths); + strv_dump(f, prefix, "ExecSearchPath", c->exec_search_path); + + for (size_t i = 0; i < c->n_bind_mounts; i++) + fprintf(f, "%s%s: %s%s:%s:%s\n", prefix, + c->bind_mounts[i].read_only ? "BindReadOnlyPaths" : "BindPaths", + c->bind_mounts[i].ignore_enoent ? "-": "", + c->bind_mounts[i].source, + c->bind_mounts[i].destination, + c->bind_mounts[i].recursive ? "rbind" : "norbind"); + + for (size_t i = 0; i < c->n_temporary_filesystems; i++) { + const TemporaryFileSystem *t = c->temporary_filesystems + i; + + fprintf(f, "%sTemporaryFileSystem: %s%s%s\n", prefix, + t->path, + isempty(t->options) ? "" : ":", + strempty(t->options)); + } + + if (c->utmp_id) + fprintf(f, + "%sUtmpIdentifier: %s\n", + prefix, c->utmp_id); + + if (c->selinux_context) + fprintf(f, + "%sSELinuxContext: %s%s\n", + prefix, c->selinux_context_ignore ? "-" : "", c->selinux_context); + + if (c->apparmor_profile) + fprintf(f, + "%sAppArmorProfile: %s%s\n", + prefix, c->apparmor_profile_ignore ? "-" : "", c->apparmor_profile); + + if (c->smack_process_label) + fprintf(f, + "%sSmackProcessLabel: %s%s\n", + prefix, c->smack_process_label_ignore ? "-" : "", c->smack_process_label); + + if (c->personality != PERSONALITY_INVALID) + fprintf(f, + "%sPersonality: %s\n", + prefix, strna(personality_to_string(c->personality))); + + fprintf(f, + "%sLockPersonality: %s\n", + prefix, yes_no(c->lock_personality)); + + if (c->syscall_filter) { + fprintf(f, + "%sSystemCallFilter: ", + prefix); + + if (!c->syscall_allow_list) + fputc('~', f); + +#if HAVE_SECCOMP + void *id, *val; + bool first = true; + HASHMAP_FOREACH_KEY(val, id, c->syscall_filter) { + _cleanup_free_ char *name = NULL; + const char *errno_name = NULL; + int num = PTR_TO_INT(val); + + if (first) + first = false; + else + fputc(' ', f); + + name = seccomp_syscall_resolve_num_arch(SCMP_ARCH_NATIVE, PTR_TO_INT(id) - 1); + fputs(strna(name), f); + + if (num >= 0) { + errno_name = seccomp_errno_or_action_to_string(num); + if (errno_name) + fprintf(f, ":%s", errno_name); + else + fprintf(f, ":%d", num); + } + } +#endif + + fputc('\n', f); + } + + if (c->syscall_archs) { + fprintf(f, + "%sSystemCallArchitectures:", + prefix); + +#if HAVE_SECCOMP + void *id; + SET_FOREACH(id, c->syscall_archs) + fprintf(f, " %s", strna(seccomp_arch_to_string(PTR_TO_UINT32(id) - 1))); +#endif + fputc('\n', f); + } + + if (exec_context_restrict_namespaces_set(c)) { + _cleanup_free_ char *s = NULL; + + r = namespace_flags_to_string(c->restrict_namespaces, &s); + if (r >= 0) + fprintf(f, "%sRestrictNamespaces: %s\n", + prefix, strna(s)); + } + +#if HAVE_LIBBPF + if (exec_context_restrict_filesystems_set(c)) { + char *fs; + SET_FOREACH(fs, c->restrict_filesystems) + fprintf(f, "%sRestrictFileSystems: %s\n", prefix, fs); + } +#endif + + if (c->network_namespace_path) + fprintf(f, + "%sNetworkNamespacePath: %s\n", + prefix, c->network_namespace_path); + + if (c->syscall_errno > 0) { + fprintf(f, "%sSystemCallErrorNumber: ", prefix); + +#if HAVE_SECCOMP + const char *errno_name = seccomp_errno_or_action_to_string(c->syscall_errno); + if (errno_name) + fputs(errno_name, f); + else + fprintf(f, "%d", c->syscall_errno); +#endif + fputc('\n', f); + } + + for (size_t i = 0; i < c->n_mount_images; i++) { + fprintf(f, "%sMountImages: %s%s:%s", prefix, + c->mount_images[i].ignore_enoent ? "-": "", + c->mount_images[i].source, + c->mount_images[i].destination); + LIST_FOREACH(mount_options, o, c->mount_images[i].mount_options) + fprintf(f, ":%s:%s", + partition_designator_to_string(o->partition_designator), + strempty(o->options)); + fprintf(f, "\n"); + } + + for (size_t i = 0; i < c->n_extension_images; i++) { + fprintf(f, "%sExtensionImages: %s%s", prefix, + c->extension_images[i].ignore_enoent ? "-": "", + c->extension_images[i].source); + LIST_FOREACH(mount_options, o, c->extension_images[i].mount_options) + fprintf(f, ":%s:%s", + partition_designator_to_string(o->partition_designator), + strempty(o->options)); + fprintf(f, "\n"); + } + + strv_dump(f, prefix, "ExtensionDirectories", c->extension_directories); +} + +bool exec_context_maintains_privileges(const ExecContext *c) { + assert(c); + + /* Returns true if the process forked off would run under + * an unchanged UID or as root. */ + + if (!c->user) + return true; + + if (streq(c->user, "root") || streq(c->user, "0")) + return true; + + return false; +} + +int exec_context_get_effective_ioprio(const ExecContext *c) { + int p; + + assert(c); + + if (c->ioprio_set) + return c->ioprio; + + p = ioprio_get(IOPRIO_WHO_PROCESS, 0); + if (p < 0) + return IOPRIO_DEFAULT_CLASS_AND_PRIO; + + return ioprio_normalize(p); +} + +bool exec_context_get_effective_mount_apivfs(const ExecContext *c) { + assert(c); + + /* Explicit setting wins */ + if (c->mount_apivfs_set) + return c->mount_apivfs; + + /* Default to "yes" if root directory or image are specified */ + if (exec_context_with_rootfs(c)) + return true; + + return false; +} + +void exec_context_free_log_extra_fields(ExecContext *c) { + assert(c); + + for (size_t l = 0; l < c->n_log_extra_fields; l++) + free(c->log_extra_fields[l].iov_base); + c->log_extra_fields = mfree(c->log_extra_fields); + c->n_log_extra_fields = 0; +} + +void exec_context_revert_tty(ExecContext *c) { + _cleanup_close_ int fd = -1; + const char *path; + struct stat st; + int r; + + assert(c); + + /* First, reset the TTY (possibly kicking everybody else from the TTY) */ + exec_context_tty_reset(c, NULL); + + /* And then undo what chown_terminal() did earlier. Note that we only do this if we have a path + * configured. If the TTY was passed to us as file descriptor we assume the TTY is opened and managed + * by whoever passed it to us and thus knows better when and how to chmod()/chown() it back. */ + if (!exec_context_may_touch_tty(c)) + return; + + path = exec_context_tty_path(c); + if (!path) + return; + + fd = open(path, O_PATH|O_CLOEXEC); /* Pin the inode */ + if (fd < 0) + return (void) log_full_errno(errno == ENOENT ? LOG_DEBUG : LOG_WARNING, errno, + "Failed to open TTY inode of '%s' to adjust ownership/access mode, ignoring: %m", + path); + + if (fstat(fd, &st) < 0) + return (void) log_warning_errno(errno, "Failed to stat TTY '%s', ignoring: %m", path); + + /* Let's add a superficial check that we only do this for stuff that looks like a TTY. We only check + * if things are a character device, since a proper check either means we'd have to open the TTY and + * use isatty(), but we'd rather not do that since opening TTYs comes with all kinds of side-effects + * and is slow. Or we'd have to hardcode dev_t major information, which we'd rather avoid. Why bother + * with this at all? → https://github.com/systemd/systemd/issues/19213 */ + if (!S_ISCHR(st.st_mode)) + return log_warning("Configured TTY '%s' is not actually a character device, ignoring.", path); + + r = fchmod_and_chown(fd, TTY_MODE, 0, TTY_GID); + if (r < 0) + log_warning_errno(r, "Failed to reset TTY ownership/access mode of %s to " UID_FMT ":" GID_FMT ", ignoring: %m", path, (uid_t) 0, (gid_t) TTY_GID); +} + +int exec_context_get_clean_directories( + ExecContext *c, + char **prefix, + ExecCleanMask mask, + char ***ret) { + + _cleanup_strv_free_ char **l = NULL; + int r; + + assert(c); + assert(prefix); + assert(ret); + + for (ExecDirectoryType t = 0; t < _EXEC_DIRECTORY_TYPE_MAX; t++) { + if (!FLAGS_SET(mask, 1U << t)) + continue; + + if (!prefix[t]) + continue; + + for (size_t i = 0; i < c->directories[t].n_items; i++) { + char *j; + + j = path_join(prefix[t], c->directories[t].items[i].path); + if (!j) + return -ENOMEM; + + r = strv_consume(&l, j); + if (r < 0) + return r; + + /* Also remove private directories unconditionally. */ + if (t != EXEC_DIRECTORY_CONFIGURATION) { + j = path_join(prefix[t], "private", c->directories[t].items[i].path); + if (!j) + return -ENOMEM; + + r = strv_consume(&l, j); + if (r < 0) + return r; + } + + STRV_FOREACH(symlink, c->directories[t].items[i].symlinks) { + j = path_join(prefix[t], *symlink); + if (!j) + return -ENOMEM; + + r = strv_consume(&l, j); + if (r < 0) + return r; + } + } + } + + *ret = TAKE_PTR(l); + return 0; +} + +int exec_context_get_clean_mask(ExecContext *c, ExecCleanMask *ret) { + ExecCleanMask mask = 0; + + assert(c); + assert(ret); + + for (ExecDirectoryType t = 0; t < _EXEC_DIRECTORY_TYPE_MAX; t++) + if (c->directories[t].n_items > 0) + mask |= 1U << t; + + *ret = mask; + return 0; +} + +void exec_status_start(ExecStatus *s, pid_t pid) { + assert(s); + + *s = (ExecStatus) { + .pid = pid, + }; + + dual_timestamp_get(&s->start_timestamp); +} + +void exec_status_exit(ExecStatus *s, const ExecContext *context, pid_t pid, int code, int status) { + assert(s); + + if (s->pid != pid) + *s = (ExecStatus) { + .pid = pid, + }; + + dual_timestamp_get(&s->exit_timestamp); + + s->code = code; + s->status = status; + + if (context && context->utmp_id) + (void) utmp_put_dead_process(context->utmp_id, pid, code, status); +} + +void exec_status_reset(ExecStatus *s) { + assert(s); + + *s = (ExecStatus) {}; +} + +void exec_status_dump(const ExecStatus *s, FILE *f, const char *prefix) { + assert(s); + assert(f); + + if (s->pid <= 0) + return; + + prefix = strempty(prefix); + + fprintf(f, + "%sPID: "PID_FMT"\n", + prefix, s->pid); + + if (dual_timestamp_is_set(&s->start_timestamp)) + fprintf(f, + "%sStart Timestamp: %s\n", + prefix, FORMAT_TIMESTAMP(s->start_timestamp.realtime)); + + if (dual_timestamp_is_set(&s->exit_timestamp)) + fprintf(f, + "%sExit Timestamp: %s\n" + "%sExit Code: %s\n" + "%sExit Status: %i\n", + prefix, FORMAT_TIMESTAMP(s->exit_timestamp.realtime), + prefix, sigchld_code_to_string(s->code), + prefix, s->status); +} + +static void exec_command_dump(ExecCommand *c, FILE *f, const char *prefix) { + _cleanup_free_ char *cmd = NULL; + const char *prefix2; + + assert(c); + assert(f); + + prefix = strempty(prefix); + prefix2 = strjoina(prefix, "\t"); + + cmd = quote_command_line(c->argv, SHELL_ESCAPE_EMPTY); + + fprintf(f, + "%sCommand Line: %s\n", + prefix, strnull(cmd)); + + exec_status_dump(&c->exec_status, f, prefix2); +} + +void exec_command_dump_list(ExecCommand *c, FILE *f, const char *prefix) { + assert(f); + + prefix = strempty(prefix); + + LIST_FOREACH(command, i, c) + exec_command_dump(i, 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_and_replace(c->path, p); + + return strv_free_and_replace(c->argv, l); +} + +int exec_command_append(ExecCommand *c, const char *path, ...) { + _cleanup_strv_free_ char **l = NULL; + va_list ap; + int r; + + assert(c); + assert(path); + + va_start(ap, path); + l = strv_new_ap(path, ap); + va_end(ap); + + if (!l) + return -ENOMEM; + + r = strv_extend_strv(&c->argv, l, false); + if (r < 0) + return r; + + return 0; +} + +static void *remove_tmpdir_thread(void *p) { + _cleanup_free_ char *path = p; + + (void) rm_rf(path, REMOVE_ROOT|REMOVE_PHYSICAL); + return NULL; +} + +static ExecRuntime* exec_runtime_free(ExecRuntime *rt, bool destroy) { + int r; + + if (!rt) + return NULL; + + if (rt->manager) + (void) hashmap_remove(rt->manager->exec_runtime_by_id, rt->id); + + /* When destroy is true, then rm_rf tmp_dir and var_tmp_dir. */ + + if (destroy && rt->tmp_dir && !streq(rt->tmp_dir, RUN_SYSTEMD_EMPTY)) { + log_debug("Spawning thread to nuke %s", rt->tmp_dir); + + r = asynchronous_job(remove_tmpdir_thread, rt->tmp_dir); + if (r < 0) + log_warning_errno(r, "Failed to nuke %s: %m", rt->tmp_dir); + else + rt->tmp_dir = NULL; + } + + if (destroy && rt->var_tmp_dir && !streq(rt->var_tmp_dir, RUN_SYSTEMD_EMPTY)) { + log_debug("Spawning thread to nuke %s", rt->var_tmp_dir); + + r = asynchronous_job(remove_tmpdir_thread, rt->var_tmp_dir); + if (r < 0) + log_warning_errno(r, "Failed to nuke %s: %m", rt->var_tmp_dir); + else + rt->var_tmp_dir = NULL; + } + + rt->id = mfree(rt->id); + rt->tmp_dir = mfree(rt->tmp_dir); + rt->var_tmp_dir = mfree(rt->var_tmp_dir); + safe_close_pair(rt->netns_storage_socket); + safe_close_pair(rt->ipcns_storage_socket); + return mfree(rt); +} + +static void exec_runtime_freep(ExecRuntime **rt) { + (void) exec_runtime_free(*rt, false); +} + +static int exec_runtime_allocate(ExecRuntime **ret, const char *id) { + _cleanup_free_ char *id_copy = NULL; + ExecRuntime *n; + + assert(ret); + + id_copy = strdup(id); + if (!id_copy) + return -ENOMEM; + + n = new(ExecRuntime, 1); + if (!n) + return -ENOMEM; + + *n = (ExecRuntime) { + .id = TAKE_PTR(id_copy), + .netns_storage_socket = { -1, -1 }, + .ipcns_storage_socket = { -1, -1 }, + }; + + *ret = n; + return 0; +} + +static int exec_runtime_add( + Manager *m, + const char *id, + char **tmp_dir, + char **var_tmp_dir, + int netns_storage_socket[2], + int ipcns_storage_socket[2], + ExecRuntime **ret) { + + _cleanup_(exec_runtime_freep) ExecRuntime *rt = NULL; + int r; + + assert(m); + assert(id); + + /* tmp_dir, var_tmp_dir, {net,ipc}ns_storage_socket fds are donated on success */ + + r = exec_runtime_allocate(&rt, id); + if (r < 0) + return r; + + r = hashmap_ensure_put(&m->exec_runtime_by_id, &string_hash_ops, rt->id, rt); + if (r < 0) + return r; + + assert(!!rt->tmp_dir == !!rt->var_tmp_dir); /* We require both to be set together */ + rt->tmp_dir = TAKE_PTR(*tmp_dir); + rt->var_tmp_dir = TAKE_PTR(*var_tmp_dir); + + if (netns_storage_socket) { + rt->netns_storage_socket[0] = TAKE_FD(netns_storage_socket[0]); + rt->netns_storage_socket[1] = TAKE_FD(netns_storage_socket[1]); + } + + if (ipcns_storage_socket) { + rt->ipcns_storage_socket[0] = TAKE_FD(ipcns_storage_socket[0]); + rt->ipcns_storage_socket[1] = TAKE_FD(ipcns_storage_socket[1]); + } + + rt->manager = m; + + if (ret) + *ret = rt; + /* do not remove created ExecRuntime object when the operation succeeds. */ + TAKE_PTR(rt); + return 0; +} + +static int exec_runtime_make( + Manager *m, + const ExecContext *c, + const char *id, + ExecRuntime **ret) { + + _cleanup_(namespace_cleanup_tmpdirp) char *tmp_dir = NULL, *var_tmp_dir = NULL; + _cleanup_close_pair_ int netns_storage_socket[2] = { -1, -1 }, ipcns_storage_socket[2] = { -1, -1 }; + int r; + + assert(m); + assert(c); + assert(id); + + /* It is not necessary to create ExecRuntime object. */ + if (!c->private_network && !c->private_ipc && !c->private_tmp && !c->network_namespace_path) { + *ret = NULL; + return 0; + } + + if (c->private_tmp && + !(prefixed_path_strv_contains(c->inaccessible_paths, "/tmp") && + (prefixed_path_strv_contains(c->inaccessible_paths, "/var/tmp") || + prefixed_path_strv_contains(c->inaccessible_paths, "/var")))) { + r = setup_tmp_dirs(id, &tmp_dir, &var_tmp_dir); + if (r < 0) + return r; + } + + if (c->private_network || c->network_namespace_path) { + if (socketpair(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, netns_storage_socket) < 0) + return -errno; + } + + if (c->private_ipc || c->ipc_namespace_path) { + if (socketpair(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, ipcns_storage_socket) < 0) + return -errno; + } + + r = exec_runtime_add(m, id, &tmp_dir, &var_tmp_dir, netns_storage_socket, ipcns_storage_socket, ret); + if (r < 0) + return r; + + return 1; +} + +int exec_runtime_acquire(Manager *m, const ExecContext *c, const char *id, bool create, ExecRuntime **ret) { + ExecRuntime *rt; + int r; + + assert(m); + assert(id); + assert(ret); + + rt = hashmap_get(m->exec_runtime_by_id, id); + if (rt) + /* We already have an ExecRuntime object, let's increase the ref count and reuse it */ + goto ref; + + if (!create) { + *ret = NULL; + return 0; + } + + /* If not found, then create a new object. */ + r = exec_runtime_make(m, c, id, &rt); + if (r < 0) + return r; + if (r == 0) { + /* When r == 0, it is not necessary to create ExecRuntime object. */ + *ret = NULL; + return 0; + } + +ref: + /* increment reference counter. */ + rt->n_ref++; + *ret = rt; + return 1; +} + +ExecRuntime *exec_runtime_unref(ExecRuntime *rt, bool destroy) { + if (!rt) + return NULL; + + assert(rt->n_ref > 0); + + rt->n_ref--; + if (rt->n_ref > 0) + return NULL; + + return exec_runtime_free(rt, destroy); +} + +int exec_runtime_serialize(const Manager *m, FILE *f, FDSet *fds) { + ExecRuntime *rt; + + assert(m); + assert(f); + assert(fds); + + HASHMAP_FOREACH(rt, m->exec_runtime_by_id) { + fprintf(f, "exec-runtime=%s", rt->id); + + if (rt->tmp_dir) + fprintf(f, " tmp-dir=%s", rt->tmp_dir); + + if (rt->var_tmp_dir) + fprintf(f, " var-tmp-dir=%s", 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; + + fprintf(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; + + fprintf(f, " netns-socket-1=%i", copy); + } + + if (rt->ipcns_storage_socket[0] >= 0) { + int copy; + + copy = fdset_put_dup(fds, rt->ipcns_storage_socket[0]); + if (copy < 0) + return copy; + + fprintf(f, " ipcns-socket-0=%i", copy); + } + + if (rt->ipcns_storage_socket[1] >= 0) { + int copy; + + copy = fdset_put_dup(fds, rt->ipcns_storage_socket[1]); + if (copy < 0) + return copy; + + fprintf(f, " ipcns-socket-1=%i", copy); + } + + fputc('\n', f); + } + + return 0; +} + +int exec_runtime_deserialize_compat(Unit *u, const char *key, const char *value, FDSet *fds) { + _cleanup_(exec_runtime_freep) ExecRuntime *rt_create = NULL; + ExecRuntime *rt; + int r; + + /* This is for the migration from old (v237 or earlier) deserialization text. + * Due to the bug #7790, this may not work with the units that use JoinsNamespaceOf=. + * Even if the ExecRuntime object originally created by the other unit, we cannot judge + * so or not from the serialized text, then we always creates a new object owned by this. */ + + assert(u); + assert(key); + assert(value); + + /* Manager manages ExecRuntime objects by the unit id. + * So, we omit the serialized text when the unit does not have id (yet?)... */ + if (isempty(u->id)) { + log_unit_debug(u, "Invocation ID not found. Dropping runtime parameter."); + return 0; + } + + if (hashmap_ensure_allocated(&u->manager->exec_runtime_by_id, &string_hash_ops) < 0) + return log_oom(); + + rt = hashmap_get(u->manager->exec_runtime_by_id, u->id); + if (!rt) { + if (exec_runtime_allocate(&rt_create, u->id) < 0) + return log_oom(); + + rt = rt_create; + } + + if (streq(key, "tmp-dir")) { + if (free_and_strdup_warn(&rt->tmp_dir, value) < 0) + return -ENOMEM; + + } else if (streq(key, "var-tmp-dir")) { + if (free_and_strdup_warn(&rt->var_tmp_dir, value) < 0) + return -ENOMEM; + + } else if (streq(key, "netns-socket-0")) { + int fd; + + if (safe_atoi(value, &fd) < 0 || !fdset_contains(fds, fd)) { + log_unit_debug(u, "Failed to parse netns socket value: %s", value); + return 0; + } + + safe_close(rt->netns_storage_socket[0]); + rt->netns_storage_socket[0] = fdset_remove(fds, fd); + + } else if (streq(key, "netns-socket-1")) { + int fd; + + if (safe_atoi(value, &fd) < 0 || !fdset_contains(fds, fd)) { + log_unit_debug(u, "Failed to parse netns socket value: %s", value); + return 0; + } + + safe_close(rt->netns_storage_socket[1]); + rt->netns_storage_socket[1] = fdset_remove(fds, fd); + + } else + return 0; + + /* If the object is newly created, then put it to the hashmap which manages ExecRuntime objects. */ + if (rt_create) { + r = hashmap_put(u->manager->exec_runtime_by_id, rt_create->id, rt_create); + if (r < 0) { + log_unit_debug_errno(u, r, "Failed to put runtime parameter to manager's storage: %m"); + return 0; + } + + rt_create->manager = u->manager; + + /* Avoid cleanup */ + TAKE_PTR(rt_create); + } + + return 1; +} + +int exec_runtime_deserialize_one(Manager *m, const char *value, FDSet *fds) { + _cleanup_free_ char *tmp_dir = NULL, *var_tmp_dir = NULL; + char *id = NULL; + int r, netns_fdpair[] = {-1, -1}, ipcns_fdpair[] = {-1, -1}; + const char *p, *v = ASSERT_PTR(value); + size_t n; + + assert(m); + assert(fds); + + n = strcspn(v, " "); + id = strndupa_safe(v, n); + if (v[n] != ' ') + goto finalize; + p = v + n + 1; + + v = startswith(p, "tmp-dir="); + if (v) { + n = strcspn(v, " "); + tmp_dir = strndup(v, n); + if (!tmp_dir) + return log_oom(); + if (v[n] != ' ') + goto finalize; + p = v + n + 1; + } + + v = startswith(p, "var-tmp-dir="); + if (v) { + n = strcspn(v, " "); + var_tmp_dir = strndup(v, n); + if (!var_tmp_dir) + return log_oom(); + if (v[n] != ' ') + goto finalize; + p = v + n + 1; + } + + v = startswith(p, "netns-socket-0="); + if (v) { + char *buf; + + n = strcspn(v, " "); + buf = strndupa_safe(v, n); + + r = safe_atoi(buf, &netns_fdpair[0]); + if (r < 0) + return log_debug_errno(r, "Unable to parse exec-runtime specification netns-socket-0=%s: %m", buf); + if (!fdset_contains(fds, netns_fdpair[0])) + return log_debug_errno(SYNTHETIC_ERRNO(EBADF), + "exec-runtime specification netns-socket-0= refers to unknown fd %d: %m", netns_fdpair[0]); + netns_fdpair[0] = fdset_remove(fds, netns_fdpair[0]); + if (v[n] != ' ') + goto finalize; + p = v + n + 1; + } + + v = startswith(p, "netns-socket-1="); + if (v) { + char *buf; + + n = strcspn(v, " "); + buf = strndupa_safe(v, n); + + r = safe_atoi(buf, &netns_fdpair[1]); + if (r < 0) + return log_debug_errno(r, "Unable to parse exec-runtime specification netns-socket-1=%s: %m", buf); + if (!fdset_contains(fds, netns_fdpair[1])) + return log_debug_errno(SYNTHETIC_ERRNO(EBADF), + "exec-runtime specification netns-socket-1= refers to unknown fd %d: %m", netns_fdpair[1]); + netns_fdpair[1] = fdset_remove(fds, netns_fdpair[1]); + if (v[n] != ' ') + goto finalize; + p = v + n + 1; + } + + v = startswith(p, "ipcns-socket-0="); + if (v) { + char *buf; + + n = strcspn(v, " "); + buf = strndupa_safe(v, n); + + r = safe_atoi(buf, &ipcns_fdpair[0]); + if (r < 0) + return log_debug_errno(r, "Unable to parse exec-runtime specification ipcns-socket-0=%s: %m", buf); + if (!fdset_contains(fds, ipcns_fdpair[0])) + return log_debug_errno(SYNTHETIC_ERRNO(EBADF), + "exec-runtime specification ipcns-socket-0= refers to unknown fd %d: %m", ipcns_fdpair[0]); + ipcns_fdpair[0] = fdset_remove(fds, ipcns_fdpair[0]); + if (v[n] != ' ') + goto finalize; + p = v + n + 1; + } + + v = startswith(p, "ipcns-socket-1="); + if (v) { + char *buf; + + n = strcspn(v, " "); + buf = strndupa_safe(v, n); + + r = safe_atoi(buf, &ipcns_fdpair[1]); + if (r < 0) + return log_debug_errno(r, "Unable to parse exec-runtime specification ipcns-socket-1=%s: %m", buf); + if (!fdset_contains(fds, ipcns_fdpair[1])) + return log_debug_errno(SYNTHETIC_ERRNO(EBADF), + "exec-runtime specification ipcns-socket-1= refers to unknown fd %d: %m", ipcns_fdpair[1]); + ipcns_fdpair[1] = fdset_remove(fds, ipcns_fdpair[1]); + } + +finalize: + r = exec_runtime_add(m, id, &tmp_dir, &var_tmp_dir, netns_fdpair, ipcns_fdpair, NULL); + if (r < 0) + return log_debug_errno(r, "Failed to add exec-runtime: %m"); + return 0; +} + +void exec_runtime_vacuum(Manager *m) { + ExecRuntime *rt; + + assert(m); + + /* Free unreferenced ExecRuntime objects. This is used after manager deserialization process. */ + + HASHMAP_FOREACH(rt, m->exec_runtime_by_id) { + if (rt->n_ref > 0) + continue; + + (void) exec_runtime_free(rt, false); + } +} + +void exec_params_clear(ExecParameters *p) { + if (!p) + return; + + p->environment = strv_free(p->environment); + p->fd_names = strv_free(p->fd_names); + p->fds = mfree(p->fds); + p->exec_fd = safe_close(p->exec_fd); +} + +ExecSetCredential *exec_set_credential_free(ExecSetCredential *sc) { + if (!sc) + return NULL; + + free(sc->id); + free(sc->data); + return mfree(sc); +} + +ExecLoadCredential *exec_load_credential_free(ExecLoadCredential *lc) { + if (!lc) + return NULL; + + free(lc->id); + free(lc->path); + return mfree(lc); +} + +void exec_directory_done(ExecDirectory *d) { + if (!d) + return; + + for (size_t i = 0; i < d->n_items; i++) { + free(d->items[i].path); + strv_free(d->items[i].symlinks); + } + + d->items = mfree(d->items); + d->n_items = 0; + d->mode = 0755; +} + +static ExecDirectoryItem *exec_directory_find(ExecDirectory *d, const char *path) { + assert(d); + assert(path); + + for (size_t i = 0; i < d->n_items; i++) + if (path_equal(d->items[i].path, path)) + return &d->items[i]; + + return NULL; +} + +int exec_directory_add(ExecDirectory *d, const char *path, const char *symlink) { + _cleanup_strv_free_ char **s = NULL; + _cleanup_free_ char *p = NULL; + ExecDirectoryItem *existing; + int r; + + assert(d); + assert(path); + + existing = exec_directory_find(d, path); + if (existing) { + r = strv_extend(&existing->symlinks, symlink); + if (r < 0) + return r; + + return 0; /* existing item is updated */ + } + + p = strdup(path); + if (!p) + return -ENOMEM; + + if (symlink) { + s = strv_new(symlink); + if (!s) + return -ENOMEM; + } + + if (!GREEDY_REALLOC(d->items, d->n_items + 1)) + return -ENOMEM; + + d->items[d->n_items++] = (ExecDirectoryItem) { + .path = TAKE_PTR(p), + .symlinks = TAKE_PTR(s), + }; + + return 1; /* new item is added */ +} + +static int exec_directory_item_compare_func(const ExecDirectoryItem *a, const ExecDirectoryItem *b) { + assert(a); + assert(b); + + return path_compare(a->path, b->path); +} + +void exec_directory_sort(ExecDirectory *d) { + assert(d); + + /* Sort the exec directories to make always parent directories processed at first in + * setup_exec_directory(), e.g., even if StateDirectory=foo/bar foo, we need to create foo at first, + * then foo/bar. Also, set .only_create flag if one of the parent directories is contained in the + * list. See also comments in setup_exec_directory() and issue #24783. */ + + if (d->n_items <= 1) + return; + + typesafe_qsort(d->items, d->n_items, exec_directory_item_compare_func); + + for (size_t i = 1; i < d->n_items; i++) + for (size_t j = 0; j < i; j++) + if (path_startswith(d->items[i].path, d->items[j].path)) { + d->items[i].only_create = true; + break; + } +} + +DEFINE_HASH_OPS_WITH_VALUE_DESTRUCTOR(exec_set_credential_hash_ops, char, string_hash_func, string_compare_func, ExecSetCredential, exec_set_credential_free); +DEFINE_HASH_OPS_WITH_VALUE_DESTRUCTOR(exec_load_credential_hash_ops, char, string_hash_func, string_compare_func, ExecLoadCredential, exec_load_credential_free); + +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", + [EXEC_INPUT_NAMED_FD] = "fd", + [EXEC_INPUT_DATA] = "data", + [EXEC_INPUT_FILE] = "file", +}; + +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_KMSG] = "kmsg", + [EXEC_OUTPUT_KMSG_AND_CONSOLE] = "kmsg+console", + [EXEC_OUTPUT_JOURNAL] = "journal", + [EXEC_OUTPUT_JOURNAL_AND_CONSOLE] = "journal+console", + [EXEC_OUTPUT_SOCKET] = "socket", + [EXEC_OUTPUT_NAMED_FD] = "fd", + [EXEC_OUTPUT_FILE] = "file", + [EXEC_OUTPUT_FILE_APPEND] = "append", + [EXEC_OUTPUT_FILE_TRUNCATE] = "truncate", +}; + +DEFINE_STRING_TABLE_LOOKUP(exec_output, ExecOutput); + +static const char* const exec_utmp_mode_table[_EXEC_UTMP_MODE_MAX] = { + [EXEC_UTMP_INIT] = "init", + [EXEC_UTMP_LOGIN] = "login", + [EXEC_UTMP_USER] = "user", +}; + +DEFINE_STRING_TABLE_LOOKUP(exec_utmp_mode, ExecUtmpMode); + +static const char* const exec_preserve_mode_table[_EXEC_PRESERVE_MODE_MAX] = { + [EXEC_PRESERVE_NO] = "no", + [EXEC_PRESERVE_YES] = "yes", + [EXEC_PRESERVE_RESTART] = "restart", +}; + +DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(exec_preserve_mode, ExecPreserveMode, EXEC_PRESERVE_YES); + +/* This table maps ExecDirectoryType to the setting it is configured with in the unit */ +static const char* const exec_directory_type_table[_EXEC_DIRECTORY_TYPE_MAX] = { + [EXEC_DIRECTORY_RUNTIME] = "RuntimeDirectory", + [EXEC_DIRECTORY_STATE] = "StateDirectory", + [EXEC_DIRECTORY_CACHE] = "CacheDirectory", + [EXEC_DIRECTORY_LOGS] = "LogsDirectory", + [EXEC_DIRECTORY_CONFIGURATION] = "ConfigurationDirectory", +}; + +DEFINE_STRING_TABLE_LOOKUP(exec_directory_type, ExecDirectoryType); + +/* This table maps ExecDirectoryType to the symlink setting it is configured with in the unit */ +static const char* const exec_directory_type_symlink_table[_EXEC_DIRECTORY_TYPE_MAX] = { + [EXEC_DIRECTORY_RUNTIME] = "RuntimeDirectorySymlink", + [EXEC_DIRECTORY_STATE] = "StateDirectorySymlink", + [EXEC_DIRECTORY_CACHE] = "CacheDirectorySymlink", + [EXEC_DIRECTORY_LOGS] = "LogsDirectorySymlink", + [EXEC_DIRECTORY_CONFIGURATION] = "ConfigurationDirectorySymlink", +}; + +DEFINE_STRING_TABLE_LOOKUP(exec_directory_type_symlink, ExecDirectoryType); + +/* And this table maps ExecDirectoryType too, but to a generic term identifying the type of resource. This + * one is supposed to be generic enough to be used for unit types that don't use ExecContext and per-unit + * directories, specifically .timer units with their timestamp touch file. */ +static const char* const exec_resource_type_table[_EXEC_DIRECTORY_TYPE_MAX] = { + [EXEC_DIRECTORY_RUNTIME] = "runtime", + [EXEC_DIRECTORY_STATE] = "state", + [EXEC_DIRECTORY_CACHE] = "cache", + [EXEC_DIRECTORY_LOGS] = "logs", + [EXEC_DIRECTORY_CONFIGURATION] = "configuration", +}; + +DEFINE_STRING_TABLE_LOOKUP(exec_resource_type, ExecDirectoryType); + +/* And this table also maps ExecDirectoryType, to the environment variable we pass the selected directory to + * the service payload in. */ +static const char* const exec_directory_env_name_table[_EXEC_DIRECTORY_TYPE_MAX] = { + [EXEC_DIRECTORY_RUNTIME] = "RUNTIME_DIRECTORY", + [EXEC_DIRECTORY_STATE] = "STATE_DIRECTORY", + [EXEC_DIRECTORY_CACHE] = "CACHE_DIRECTORY", + [EXEC_DIRECTORY_LOGS] = "LOGS_DIRECTORY", + [EXEC_DIRECTORY_CONFIGURATION] = "CONFIGURATION_DIRECTORY", +}; + +DEFINE_PRIVATE_STRING_TABLE_LOOKUP_TO_STRING(exec_directory_env_name, ExecDirectoryType); + +static const char* const exec_keyring_mode_table[_EXEC_KEYRING_MODE_MAX] = { + [EXEC_KEYRING_INHERIT] = "inherit", + [EXEC_KEYRING_PRIVATE] = "private", + [EXEC_KEYRING_SHARED] = "shared", +}; + +DEFINE_STRING_TABLE_LOOKUP(exec_keyring_mode, ExecKeyringMode); |