/* Setup necessary system files for, e.g. UTMP (tracking logins) * * Copyright (c) 2012-2022 Joachim Wiberg * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ #include "config.h" /* Generated by configure script */ #include #ifdef HAVE_MNTENT_H #include #endif #include #ifdef _LIBITE_LITE # include #else # include #endif #include "config.h" #include "finit.h" #include "helpers.h" #include "plugin.h" #include "util.h" #include "utmp-api.h" static int is_tmpfs(char *path) { struct mntent mount; struct mntent *mnt; char buf[256]; int tmpfs = 0; FILE *fp; char *dir; /* If path is a symlink, check what it resolves to */ dir = realpath(path, NULL); if (!dir) return 0; /* Outlook not so good */ fp = setmntent("/proc/mounts", "r"); if (!fp) { free(dir); return 0; /* Dunno, maybe not */ } while ((mnt = getmntent_r(fp, &mount, buf, sizeof(buf)))) { if (!strcmp(dir, mnt->mnt_dir)) break; } if (mnt && !strcmp("tmpfs", mnt->mnt_type)) tmpfs = 1; endmntent(fp); free(dir); return tmpfs; } static int bootclean(const char *fpath, const struct stat *sb, int tflag, struct FTW *ftw) { if (ftw->level == 0) return 1; dbg("Removing %s ...", fpath); (void)remove(fpath); return 0; } /* * Cleanup stale files from previous boot, if any still linger on. * Some systems, e.g. Alpine Linux, still have a persistent /run and * /tmp, i.e. not tmpfs. * * We can safely skip tmpfs, nothing to clean there. */ static void clean(void *arg) { char *dir[] = { "/tmp/", "/var/run/", "/var/lock/", NULL }; for (int i = 0; dir[i]; i++) { if (is_tmpfs(dir[i])) continue; nftw(dir[i], bootclean, 20, FTW_DEPTH); } } static void ln(const char *target, const char *linkpath) { if (symlink(target, linkpath) && errno != EEXIST) err(1, "Failed creating %s -> %s symlink", target, linkpath); } /* Kernel defines the following compulsory and recommended links * https://github.com/torvalds/linux/blob/v5.18/Documentation/admin-guide/devices.rst#compulsory-links */ static void kernel_links(void) { struct { char *tgt, *lnk; int optional; } k[] = { { "/proc/self/fd", "/dev/fd", 0 }, { "fd/0", "/dev/stdin", 0 }, { "fd/1", "/dev/stdout", 0 }, { "fd/2", "/dev/stderr", 0 }, { "socksys", "/dev/nfsd", 0 }, { "null", "/dev/X0R", 0 }, { "/proc/kcore", "/dev/core", 1 }, { "ram0", "/dev/ramdisk", 1 }, { "qft0", "/dev/ftape", 1 }, { "video0", "/dev/bttv0", 1 }, { "radio0", "/dev/radio", 1 }, }; char *fn, buf[80]; size_t i; for (i = 0; i < NELEMS(k); i++) { fn = k[i].tgt; if (k[i].optional) { if (fn[0] != '/') { snprintf(buf, sizeof(buf), "/dev/%s", k[i].tgt); fn = buf; } if (!fexist(fn)) continue; } ln(k[i].tgt, k[i].lnk); } } /* * Setup standard FHS 2.3 structure in /var, and write runlevel to UTMP */ static void setup(void *arg) { mode_t prev; prev = umask(0); dbg("Setting up FHS structure in /var ..."); makedir("/var/cache", 0755); makedir("/var/db", 0755); /* _PATH_VARDB on some systems */ makedir("/var/games", 0755); makedir("/var/lib", 0755); makedir("/var/lib/misc", 0755); /* _PATH_VARDB on some systems */ makedir("/var/lib/alarm", 0755); makedir("/var/lib/urandom",0755); if (fisdir("/run")) { dbg("System with new /run tmpfs ..."); if (!fisdir("/run/lock")) makedir("/run/lock", 1777); ln("/run/lock", "/var/lock"); ln("/dev/shm", "/run/shm"); /* compat only, should really be set up by OS/dist */ ln("/run", "/var/run"); } else { makedir("/var/lock", 1777); makedir("/var/run", 0755); } makedir("/var/log", 0755); makedir("/var/mail", 0755); makedir("/var/opt", 0755); makedir("/var/spool", 0755); makedir("/var/spool/cron", 0755); makedir("/var/tmp", 0755); makedir("/var/empty", 0755); /* * UTMP actually needs multiple db files */ if (has_utmp()) { int gid; /* * If /etc/group or "utmp" group is missing, default to * "root", or "wheel", group. */ dbg("Setting up necessary UTMP files ..."); gid = getgroup("utmp"); if (gid < 0) gid = 0; create("/var/run/utmp", 0644, 0, gid); /* Currently logged in */ create("/var/log/wtmp", 0644, 0, gid); /* Login history */ create("/var/log/btmp", 0600, 0, gid); /* Failed logins */ create("/var/log/lastlog", 0644, 0, gid); } /* Set BOOT_TIME UTMP entry */ utmp_set_boot(); #ifdef TOUCH_ETC_NETWORK_RUN_IFSTATE touch("/etc/network/run/ifstate"); #else erase("/etc/network/run/ifstate"); #endif dbg("Setting up misc files ..."); makedir("/var/run/network",0755); /* Needed by Debian/Ubuntu ifupdown */ makedir("/var/run/lldpd", 0755); /* Needed by lldpd */ makedir("/var/run/pluto", 0755); /* Needed by Openswan */ mksubsys("/var/run/quagga", 0755, "quagga", "quagga"); mksubsys("/var/log/quagga", 0755, "quagga", "quagga"); mksubsys("/var/run/frr", 0755, "frr", "frr"); mksubsys("/var/log/frr", 0755, "frr", "frr"); makedir("/var/run/sshd", 01755); /* OpenSSH */ if (!fexist("/etc/mtab")) ln("../proc/self/mounts", "/etc/mtab"); /* Void Linux has a uuidd that runs as uuid:uuid and needs /run/uuid */ mksubsys("/var/run/uuidd", 0755, "uuidd", "uuidd"); /* Debian has /run/sudo, ensure correct perms and SELinux label */ mksubsys("/var/run/sudo", 0711, "root", "root"); mksubsys("/var/run/sudo/ts", 0700, "root", "root"); if (whichp("restorecon")) run("restorecon /var/run/sudo /var/run/sudo/ts", "restorecon"); /* Kernel symlinks, e.g. /proc/self/fd -> /dev/fd */ kernel_links(); umask(prev); } static plugin_t plugin = { .name = __FILE__, .hook[HOOK_MOUNT_POST] = { .cb = clean }, .hook[HOOK_BASEFS_UP] = { .cb = setup }, .depends = { "pidfile" }, }; PLUGIN_INIT(plugin_init) { plugin_register(&plugin); } PLUGIN_EXIT(plugin_exit) { plugin_unregister(&plugin); } /** * Local Variables: * indent-tabs-mode: t * c-file-style: "linux" * End: */