/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. Copyright 2010 Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include <string.h> #include <errno.h> #include <unistd.h> #include <fcntl.h> #include "log.h" #include "util.h" #include "mkdir.h" #include "unit-name.h" #include "virt.h" #include "fileio.h" #include "path-util.h" static const char *arg_dest = "/tmp"; static int add_symlink(const char *fservice, const char *tservice) { char *from, *to; int r; assert(fservice); assert(tservice); from = strappenda(SYSTEM_DATA_UNIT_PATH "/", fservice); to = strappenda(arg_dest, "/getty.target.wants/", tservice); mkdir_parents_label(to, 0755); r = symlink(from, to); if (r < 0) { if (errno == EEXIST) /* In case console=hvc0 is passed this will very likely result in EEXIST */ return 0; else { log_error_errno(errno, "Failed to create symlink %s: %m", to); return -errno; } } return 0; } static int add_serial_getty(const char *tty) { _cleanup_free_ char *n = NULL; assert(tty); log_debug("Automatically adding serial getty for /dev/%s.", tty); n = unit_name_from_path_instance("serial-getty", tty, ".service"); if (!n) return log_oom(); return add_symlink("serial-getty@.service", n); } static int add_container_getty(const char *tty) { _cleanup_free_ char *n = NULL; assert(tty); log_debug("Automatically adding container getty for /dev/pts/%s.", tty); n = unit_name_from_path_instance("container-getty", tty, ".service"); if (!n) return log_oom(); return add_symlink("container-getty@.service", n); } static int verify_tty(const char *name) { _cleanup_close_ int fd = -1; const char *p; /* Some TTYs are weird and have been enumerated but don't work * when you try to use them, such as classic ttyS0 and * friends. Let's check that and open the device and run * isatty() on it. */ p = strappenda("/dev/", name); /* O_NONBLOCK is essential here, to make sure we don't wait * for DCD */ fd = open(p, O_RDWR|O_NONBLOCK|O_NOCTTY|O_CLOEXEC|O_NOFOLLOW); if (fd < 0) return -errno; errno = 0; if (isatty(fd) <= 0) return errno ? -errno : -EIO; return 0; } int main(int argc, char *argv[]) { static const char virtualization_consoles[] = "hvc0\0" "xvc0\0" "hvsi0\0" "sclp_line0\0" "ttysclp0\0" "3270!tty1\0"; _cleanup_free_ char *active = NULL; const char *j; int r; if (argc > 1 && argc != 4) { log_error("This program takes three or no arguments."); return EXIT_FAILURE; } if (argc > 1) arg_dest = argv[1]; log_set_target(LOG_TARGET_SAFE); log_parse_environment(); log_open(); umask(0022); if (detect_container(NULL) > 0) { _cleanup_free_ char *container_ttys = NULL; log_debug("Automatically adding console shell."); if (add_symlink("console-getty.service", "console-getty.service") < 0) return EXIT_FAILURE; /* When $container_ttys is set for PID 1, spawn * gettys on all ptys named therein. Note that despite * the variable name we only support ptys here. */ r = getenv_for_pid(1, "container_ttys", &container_ttys); if (r > 0) { const char *word, *state; size_t l; FOREACH_WORD(word, l, container_ttys, state) { const char *t; char tty[l + 1]; memcpy(tty, word, l); tty[l] = 0; /* First strip off /dev/ if it is specified */ t = path_startswith(tty, "/dev/"); if (!t) t = tty; /* Then, make sure it's actually a pty */ t = path_startswith(t, "pts/"); if (!t) continue; if (add_container_getty(t) < 0) return EXIT_FAILURE; } } /* Don't add any further magic if we are in a container */ return EXIT_SUCCESS; } if (read_one_line_file("/sys/class/tty/console/active", &active) >= 0) { const char *word, *state; size_t l; /* Automatically add in a serial getty on all active * kernel consoles */ FOREACH_WORD(word, l, active, state) { _cleanup_free_ char *tty = NULL; tty = strndup(word, l); if (!tty) { log_oom(); return EXIT_FAILURE; } if (isempty(tty) || tty_is_vc(tty)) continue; if (verify_tty(tty) < 0) continue; /* We assume that gettys on virtual terminals are * started via manual configuration and do this magic * only for non-VC terminals. */ if (add_serial_getty(tty) < 0) return EXIT_FAILURE; } } /* Automatically add in a serial getty on the first * virtualizer console */ NULSTR_FOREACH(j, virtualization_consoles) { char *p; p = strappenda("/sys/class/tty/", j); if (access(p, F_OK) < 0) continue; if (add_serial_getty(j) < 0) return EXIT_FAILURE; } return EXIT_SUCCESS; }