diff --git a/man/systemd.exec.xml b/man/systemd.exec.xml index c25d96e9f..f1624923c 100644 --- a/man/systemd.exec.xml +++ b/man/systemd.exec.xml @@ -1247,6 +1247,135 @@ + + Environment variables in spawned processes + + Processes started by the system are executed in + a clean environment in which select variables + listed below are set. System processes started by systemd + do not inherit variables from PID 1, but processes + started by user systemd instances inherit all + environment variables from the user systemd instance. + + + + + $PATH + + Colon-separated list + of directiories to use when launching + executables. Systemd uses a fixed + value of + /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin. + + + + + $LANG + + Locale. Can be set in + locale.conf5 + or on the kernel command line (see + systemd1 + and + kernel-command-line7). + + + + + $USER + $LOGNAME + $HOME + $SHELL + + User name (twice), home + directory, and the login shell. + Set for the units which + have User= set, + which includes user + systemd instances. + See + passwd5. + + + + + $XDG_RUNTIME_DIR + + The directory for volatile + state. Set for the user systemd + instance, and also in user sessions. + See + pam_systemd8. + + + + + $XDG_SESSION_ID + $XDG_SEAT + $XDG_VTNR + + The identifier of the + session, and the seat name, and + virtual terminal of the session. Set + by + pam_systemd8 + for login sessions. + $XDG_SEAT and + $XDG_VTNR will be + only set when attached to a seat and a + tty. + + + + $MANAGERPID + + The PID of the user + systemd instance, + set for processes spawned by it. + + + + + $LISTEN_FDS + $LISTEN_PID + + Information about file + descriptors passed to a service for + socket activation. See + sd_listen_fds3. + + + + + $TERM + + Terminal type, set + only for units connected to a terminal + (StandardInput=tty, + StandardOutput=tty, + or + StandardError=tty). + See + termcap5. + + + + + Additional variables may be configured by the + following means: for processes spawned in specific + units, use the Environment= and + EnvironmentFile= options above; to + specify variables globally, use + DefaultEnvironment= (see + systemd-system.conf5) + or the kernel option + systemd.setenv= (see + systemd1). Additional + variables may also be set through PAM, + c.f. pam_env8. + + See Also diff --git a/src/core/execute.c b/src/core/execute.c index 11993df01..4da44c2ea 100644 --- a/src/core/execute.c +++ b/src/core/execute.c @@ -1065,7 +1065,7 @@ int exec_spawn(ExecCommand *command, if (pid == 0) { int i, err; sigset_t ss; - const char *username = NULL, *home = NULL; + const char *username = NULL, *home = NULL, *shell = NULL; uid_t uid = (uid_t) -1; gid_t gid = (gid_t) -1; char _cleanup_strv_free_ **our_env = NULL, **pam_env = NULL, @@ -1255,7 +1255,7 @@ int exec_spawn(ExecCommand *command, if (context->user) { username = context->user; - err = get_user_creds(&username, &uid, &gid, &home, NULL); + err = get_user_creds(&username, &uid, &gid, &home, &shell); if (err < 0) { r = EXIT_USER; goto fail_child; @@ -1453,46 +1453,28 @@ int exec_spawn(ExecCommand *command, } } - our_env = new0(char*, 7); - if (!our_env) { + our_env = new(char*, 8); + if (!our_env || + (n_fds > 0 && ( + asprintf(our_env + n_env++, "LISTEN_PID=%lu", (unsigned long) getpid()) < 0 || + asprintf(our_env + n_env++, "LISTEN_FDS=%u", n_fds) < 0)) || + (home && asprintf(our_env + n_env++, "HOME=%s", home) < 0) || + (username && ( + asprintf(our_env + n_env++, "LOGNAME=%s", username) < 0 || + asprintf(our_env + n_env++, "USER=%s", username) < 0)) || + (shell && asprintf(our_env + n_env++, "SHELL=%s", shell) < 0) || + ((is_terminal_input(context->std_input) || + context->std_output == EXEC_OUTPUT_TTY || + context->std_error == EXEC_OUTPUT_TTY) && ( + !(our_env[n_env++] = strdup(default_term_for_tty(tty_path(context))))))) { + err = -ENOMEM; r = EXIT_MEMORY; goto fail_child; } - if (n_fds > 0) - if (asprintf(our_env + n_env++, "LISTEN_PID=%lu", (unsigned long) getpid()) < 0 || - asprintf(our_env + n_env++, "LISTEN_FDS=%u", n_fds) < 0) { - err = -ENOMEM; - r = EXIT_MEMORY; - goto fail_child; - } - - if (home) - if (asprintf(our_env + n_env++, "HOME=%s", home) < 0) { - err = -ENOMEM; - r = EXIT_MEMORY; - goto fail_child; - } - - if (username) - if (asprintf(our_env + n_env++, "LOGNAME=%s", username) < 0 || - asprintf(our_env + n_env++, "USER=%s", username) < 0) { - err = -ENOMEM; - r = EXIT_MEMORY; - goto fail_child; - } - - if (is_terminal_input(context->std_input) || - context->std_output == EXEC_OUTPUT_TTY || - context->std_error == EXEC_OUTPUT_TTY) - if (!(our_env[n_env++] = strdup(default_term_for_tty(tty_path(context))))) { - err = -ENOMEM; - r = EXIT_MEMORY; - goto fail_child; - } - - assert(n_env <= 7); + our_env[n_env++] = NULL; + assert(n_env <= 8); final_env = strv_env_merge(5, environment,