securebits-util: add secure_bits_{from_string,to_string_alloc}()

src/basic/meson.build

@@ -139,6 +139,8 @@ basic_sources_plain = files('''
         rm-rf.c
         rm-rf.h
         securebits.h
+        securebits-util.c
+        securebits-util.h
         selinux-util.c
         selinux-util.h
         set.h

src/basic/securebits-util.c

@@ -0,0 +1,84 @@
+/***
+  This file is part of systemd.
+
+  Copyright 2017 Yu Watanabe
+
+  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 <errno.h>
+
+#include "alloc-util.h"
+#include "extract-word.h"
+#include "securebits.h"
+#include "securebits-util.h"
+#include "string-util.h"
+
+int secure_bits_to_string_alloc(int i, char **s) {
+        _cleanup_free_ char *str = NULL;
+        size_t len;
+        int r;
+
+        assert(s);
+
+        r = asprintf(&str, "%s%s%s%s%s%s",
+                     (i & (1 << SECURE_KEEP_CAPS)) ? "keep-caps " : "",
+                     (i & (1 << SECURE_KEEP_CAPS_LOCKED)) ? "keep-caps-locked " : "",
+                     (i & (1 << SECURE_NO_SETUID_FIXUP)) ? "no-setuid-fixup " : "",
+                     (i & (1 << SECURE_NO_SETUID_FIXUP_LOCKED)) ? "no-setuid-fixup-locked " : "",
+                     (i & (1 << SECURE_NOROOT)) ? "noroot " : "",
+                     (i & (1 << SECURE_NOROOT_LOCKED)) ? "noroot-locked " : "");
+        if (r < 0)
+                return -ENOMEM;
+
+        len = strlen(str);
+        if (len != 0)
+                str[len - 1] = '\0';
+
+        *s = str;
+        str = NULL;
+
+        return 0;
+}
+
+int secure_bits_from_string(const char *s) {
+        int secure_bits = 0;
+        const char *p;
+        int r;
+
+        for (p = s;;) {
+                _cleanup_free_ char *word = NULL;
+
+                r = extract_first_word(&p, &word, NULL, EXTRACT_QUOTES);
+                if (r == -ENOMEM)
+                        return r;
+                if (r <= 0)
+                        break;
+
+                if (streq(word, "keep-caps"))
+                        secure_bits |= 1 << SECURE_KEEP_CAPS;
+                else if (streq(word, "keep-caps-locked"))
+                        secure_bits |= 1 << SECURE_KEEP_CAPS_LOCKED;
+                else if (streq(word, "no-setuid-fixup"))
+                        secure_bits |= 1 << SECURE_NO_SETUID_FIXUP;
+                else if (streq(word, "no-setuid-fixup-locked"))
+                        secure_bits |= 1 << SECURE_NO_SETUID_FIXUP_LOCKED;
+                else if (streq(word, "noroot"))
+                        secure_bits |= 1 << SECURE_NOROOT;
+                else if (streq(word, "noroot-locked"))
+                        secure_bits |= 1 << SECURE_NOROOT_LOCKED;
+        }
+
+        return secure_bits;
+}

src/basic/securebits-util.h

@@ -0,0 +1,28 @@
+#pragma once
+
+/***
+  This file is part of systemd.
+
+  Copyright 2017 Yu Watanabe
+
+  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 "securebits.h"
+
+int secure_bits_to_string_alloc(int i, char **s);
+int secure_bits_from_string(const char *s);
+static inline bool secure_bits_is_valid(int i) {
+        return ((SECURE_ALL_BITS | SECURE_ALL_LOCKS) & i) == i;
+}