tempfiles: add little utility for creating volatile files/dirs in tmpfs hierarchies

4 files changed, 322 insertions, 6 deletions

diff --git a/.gitignore b/.gitignore
index b5fc8d72b0..4536356383 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
+systemd-tempfiles
 systemd-readahead-collect
 systemd-readahead-replay
 systemd-reply-password
diff --git a/Makefile.am b/Makefile.am
index 70a6c190f9..342b2b241b 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -94,7 +94,8 @@ rootlibexec_PROGRAMS = \
 	systemd-vconsole-setup \
 	systemd-reply-password \
 	systemd-readahead-collect \
-	systemd-readahead-replay
+	systemd-readahead-replay \
+	systemd-tempfiles
 
 noinst_PROGRAMS = \
 	test-engine \
@@ -620,6 +621,15 @@ systemd_modules_load_SOURCES = \
 systemd_modules_load_CFLAGS = \
 	$(AM_CFLAGS)
 
+systemd_tempfiles_LDADD = \
+	libsystemd-basic.la
+
+systemd_tempfiles_SOURCES = \
+	src/tempfiles.c
+
+systemd_tempfiles_CFLAGS = \
+	$(AM_CFLAGS)
+
 systemd_modules_load_LDADD = \
 	libsystemd-basic.la
 
diff --git a/fixme b/fixme
index 68a64890e2..f66f07a036 100644
--- a/fixme
+++ b/fixme
@@ -89,19 +89,17 @@
 
 * ask-password tty timeout
 
-* readahead() vs. fadvise() vs. ioprio
-
 * properly handle multiple inotify events per read() in path.c and util.c
 
-* tmpwatch: what does "-umc" actually mean?
-
 * tmpwatch: lower ioprio
 
 * readahead: btrfs/LVM SSD detection
 
 * LSB provides should only create targets, never aliases
 
-* d /var/run/screen 0755 root utmp
+* s/tempfiles/volatile-files/
+
+* use .conf suffix for locale/vconsole/...
 
 External:
 
diff --git a/src/tempfiles.c b/src/tempfiles.c
new file mode 100644
index 0000000000..80e424f7b6
--- /dev/null
+++ b/src/tempfiles.c
@@ -0,0 +1,307 @@
+/*-*- 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 General Public License as published by
+  the Free Software Foundation; either version 2 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
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <limits.h>
+#include <dirent.h>
+#include <grp.h>
+#include <pwd.h>
+
+#include "log.h"
+#include "util.h"
+#include "strv.h"
+#include "label.h"
+
+/* This reads all files listed in /etc/tempfiles.d/?*.conf and creates
+ * them in the file system. This is intended to be used to create
+ * properly owned directories beneath /tmp, /var/tmp, /var/run and
+ * /var/lock which are volatile and hence need to be recreated on
+ * bootup. */
+
+static void process_line(const char *fname, unsigned line, const char *buffer, const char *prefix) {
+        char type;
+        char *path = NULL;
+        unsigned mode;
+        char *user = NULL, *group = NULL;
+        uid_t uid;
+        gid_t gid;
+        bool uid_set = false, gid_set = false;
+        int n, fd = -1;
+
+        assert(fname);
+        assert(line >= 1);
+        assert(buffer);
+
+        if ((n = sscanf(buffer,
+                        "%c "
+                        "%ms "
+                        "%o "
+                        "%ms "
+                        "%ms ",
+                        &type,
+                        &path,
+                        &mode,
+                        &user,
+                        &group)) < 2) {
+                log_error("[%s:%u] Syntax error.", fname, line);
+                goto finish;
+        }
+
+        if (type != 'f' && type != 'd') {
+                log_error("[%s:%u] Unknown file type '%c'.", fname, line, type);
+                goto finish;
+        }
+
+        if (prefix && !path_startswith(path, prefix))
+                goto finish;
+
+        if (user && !streq(user, "-")) {
+                unsigned long lu;
+                struct passwd *p;
+
+                if (streq(user, "root") || streq(user, "0"))
+                        uid = 0;
+                else if (safe_atolu(user, &lu) >= 0)
+                        uid = (uid_t) lu;
+                else if ((p = getpwnam(user)))
+                        uid = p->pw_uid;
+                else {
+                        log_error("[%s:%u] Unknown user '%s'.", fname, line, user);
+                        goto finish;
+                }
+
+                uid_set = true;
+        }
+
+        if (group && !streq(group, "-")) {
+                unsigned long lu;
+                struct group *g;
+
+                if (streq(group, "root") || streq(group, "0"))
+                        gid = 0;
+                else if (safe_atolu(group, &lu) >= 0)
+                        gid = (gid_t) lu;
+                else if ((g = getgrnam(group)))
+                        gid = g->gr_gid;
+                else {
+                        log_error("[%s:%u] Unknown group '%s'.", fname, line, group);
+                        goto finish;
+                }
+
+                gid_set = true;
+        }
+
+        if (n < 3)
+                mode = type == 'f' ? 0644 : 0755;
+
+        if (type == 'f') {
+                mode_t u;
+                struct stat st;
+
+                u = umask(0);
+                fd = open(path, O_CREAT|O_NDELAY|O_CLOEXEC|O_WRONLY|O_NOCTTY|O_NOFOLLOW, mode);
+                umask(u);
+
+                if (fd < 0) {
+                        log_error("Failed to create file %s: %m", path);
+                        goto finish;
+                }
+
+                if (fstat(fd, &st) < 0) {
+                        log_error("stat(%s) failed: %m", path);
+                        goto finish;
+                }
+
+                if (!S_ISREG(st.st_mode)) {
+                        log_error("%s is not a file.", path);
+                        goto finish;
+                }
+
+                if (fchmod(fd, mode) < 0) {
+                        log_error("chmod(%s) failed: %m", path);
+                        goto finish;
+                }
+
+                if (uid_set || gid_set) {
+
+                        if (fchown(fd,
+                                   uid_set ? uid : (uid_t) -1,
+                                   gid_set ? gid : (gid_t) -1) < 0) {
+                                log_error("chown(%s) failed: %m", path);
+                                goto finish;
+                        }
+                }
+
+        } else if (type == 'd') {
+                mode_t u;
+                int r;
+                struct stat st;
+
+                u = umask(0);
+                r = mkdir(path, mode);
+                umask(u);
+
+                if (r < 0 && errno != EEXIST) {
+                        log_error("Failed to create directory %s: %m", path);
+                        goto finish;
+                }
+
+                if (stat(path, &st) < 0) {
+                        log_error("stat(%s) failed: %m", path);
+                        goto finish;
+                }
+
+                if (!S_ISDIR(st.st_mode)) {
+                        log_error("%s is not a directory.", path);
+                        goto finish;
+                }
+
+                if (chmod(path, mode) < 0) {
+                        log_error("chmod(%s) failed: %m", path);
+                        goto finish;
+                }
+
+                if (uid_set || gid_set) {
+
+                        if (chown(path,
+                                   uid_set ? uid : (uid_t) -1,
+                                   gid_set ? gid : (gid_t) -1) < 0) {
+                                log_error("chown(%s) failed: %m", path);
+                                goto finish;
+                        }
+                }
+        }
+
+        label_fix(path);
+
+        log_debug("%s created successfully.", path);
+
+finish:
+        free(path);
+        free(user);
+        free(group);
+
+        if (fd >= 0)
+                close_nointr_nofail(fd);
+}
+
+static int scandir_filter(const struct dirent *d) {
+        assert(d);
+
+        if (ignore_file(d->d_name))
+                return 0;
+
+        if (d->d_type != DT_REG &&
+            d->d_type != DT_LNK)
+                return 0;
+
+        return endswith(d->d_name, ".conf");
+}
+
+int main(int argc, char *argv[]) {
+        struct dirent **de = NULL;
+        int r = EXIT_FAILURE, n, i;
+        const char *prefix = NULL;
+
+        if (argc > 2) {
+                log_error("This program takes no more than one argument.");
+                return EXIT_FAILURE;
+        } else if (argc > 1)
+                prefix = argv[1];
+        else
+                prefix = "/";
+
+        log_set_target(LOG_TARGET_SYSLOG_OR_KMSG);
+        log_parse_environment();
+        log_open();
+
+        label_init();
+
+        if ((n = scandir("/etc/tempfiles.d/", &de, scandir_filter, alphasort)) < 0) {
+
+                if (errno == ENOENT)
+                        r = EXIT_SUCCESS;
+                else
+                        log_error("Failed to enumerate /etc/tempfiles.d/ files: %m");
+
+                goto finish;
+        }
+
+        r = EXIT_SUCCESS;
+
+        for (i = 0; i < n; i++) {
+                int k;
+                char *fn;
+                FILE *f;
+                unsigned j;
+
+                k = asprintf(&fn, "/etc/tempfiles.d/%s", de[i]->d_name);
+                free(de[i]);
+
+                if (k < 0) {
+                        log_error("Failed to allocate file name.");
+                        r = EXIT_FAILURE;
+                        continue;
+                }
+
+                f = fopen(fn, "re");
+                free(fn);
+
+                if (!f) {
+                        log_error("Failed to open %s: %m", fn);
+                        r = EXIT_FAILURE;
+                        continue;
+                }
+
+                j = 0;
+                for (;;) {
+                        char line[LINE_MAX], *l;
+
+                        if (!(fgets(line, sizeof(line), f)))
+                                break;
+
+                        j++;
+
+                        l = strstrip(line);
+                        if (*l == '#' || *l == 0)
+                                continue;
+
+                        process_line(de[i]->d_name, j, l, prefix);
+                }
+
+                if (ferror(f)) {
+                        r = EXIT_FAILURE;
+                        log_error("Failed to read from file: %m");
+                }
+
+                fclose(f);
+        }
+
+        free(de);
+
+finish:
+
+        return r;
+}