resolved: add a DNS client stub resolver

Let's turn resolved into a something truly useful: a fully asynchronous
DNS stub resolver that subscribes to network changes.

(More to come: caching, LLMNR, mDNS/DNS-SD, DNSSEC, IDN, NSS module)

1 files changed, 173 insertions, 0 deletions

diff --git a/src/resolve/test-dns-domain.c b/src/resolve/test-dns-domain.c
new file mode 100644
index 0000000000..bd53402be8
--- /dev/null
+++ b/src/resolve/test-dns-domain.c
@@ -0,0 +1,173 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2014 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 "log.h"
+#include "resolved-dns-domain.h"
+
+static void test_dns_label_unescape_one(const char *what, const char *expect, size_t buffer_sz, int ret) {
+        char buffer[buffer_sz];
+        int r;
+
+        r = dns_label_unescape(&what, buffer, buffer_sz);
+        assert_se(r == ret);
+
+        if (r < 0)
+                return;
+
+        assert_se(streq(buffer, expect));
+}
+
+static void test_dns_label_unescape(void) {
+        test_dns_label_unescape_one("hallo", "hallo", 6, 5);
+        test_dns_label_unescape_one("hallo", "hallo", 4, -ENOSPC);
+        test_dns_label_unescape_one("", "", 10, 0);
+        test_dns_label_unescape_one("hallo\\.foobar", "hallo.foobar", 20, 12);
+        test_dns_label_unescape_one("hallo.foobar", "hallo", 10, 5);
+        test_dns_label_unescape_one("hallo\n.foobar", "hallo", 20, -EINVAL);
+        test_dns_label_unescape_one("hallo\\", "hallo", 20, -EINVAL);
+        test_dns_label_unescape_one("hallo\\032 ", "hallo  ", 20, 7);
+        test_dns_label_unescape_one(".", "", 20, 0);
+        test_dns_label_unescape_one("..", "", 20, -EINVAL);
+        test_dns_label_unescape_one(".foobar", "", 20, -EINVAL);
+        test_dns_label_unescape_one("foobar.", "foobar", 20, 6);
+}
+
+static void test_dns_label_escape_one(const char *what, size_t l, const char *expect, int ret) {
+        _cleanup_free_ char *t = NULL;
+        int r;
+
+        r = dns_label_escape(what, l, &t);
+        assert(r == ret);
+
+        if (r < 0)
+                return;
+
+        assert_se(streq_ptr(expect, t));
+}
+
+static void test_dns_label_escape(void) {
+        test_dns_label_escape_one("", 0, "", 0);
+        test_dns_label_escape_one("hallo", 5, "hallo", 5);
+        test_dns_label_escape_one("hallo", 6, NULL, -EINVAL);
+        test_dns_label_escape_one("hallo hallo.foobar,waldi", 24, "hallo\\032hallo\\.foobar\\044waldi", 31);
+}
+
+static void test_dns_name_normalize_one(const char *what, const char *expect, int ret) {
+        _cleanup_free_ char *t = NULL;
+        int r;
+
+        r = dns_name_normalize(what, &t);
+        assert_se(r == ret);
+
+        if (r < 0)
+                return;
+
+        assert_se(streq_ptr(expect, t));
+}
+
+static void test_dns_name_normalize(void) {
+        test_dns_name_normalize_one("", "", 0);
+        test_dns_name_normalize_one("f", "f", 0);
+        test_dns_name_normalize_one("f.waldi", "f.waldi", 0);
+        test_dns_name_normalize_one("f \\032.waldi", "f\\032\\032.waldi", 0);
+        test_dns_name_normalize_one("\\000", NULL, -EINVAL);
+        test_dns_name_normalize_one("..", NULL, -EINVAL);
+        test_dns_name_normalize_one(".foobar", NULL, -EINVAL);
+        test_dns_name_normalize_one("foobar.", "foobar", 0);
+        test_dns_name_normalize_one(".", "", 0);
+}
+
+static void test_dns_name_equal_one(const char *a, const char *b, int ret) {
+        int r;
+
+        r = dns_name_equal(a, b);
+        assert_se(r == ret);
+
+        r = dns_name_equal(b, a);
+        assert_se(r == ret);
+}
+
+static void test_dns_name_equal(void) {
+        test_dns_name_equal_one("", "", true);
+        test_dns_name_equal_one("x", "x", true);
+        test_dns_name_equal_one("x", "x.", true);
+        test_dns_name_equal_one("abc.def", "abc.def", true);
+        test_dns_name_equal_one("abc.def", "ABC.def", true);
+        test_dns_name_equal_one("abc.def", "CBA.def", false);
+        test_dns_name_equal_one("", "xxx", false);
+        test_dns_name_equal_one("ab", "a", false);
+        test_dns_name_equal_one("\\000", "xxxx", -EINVAL);
+        test_dns_name_equal_one(".", "", true);
+        test_dns_name_equal_one(".", ".", true);
+        test_dns_name_equal_one("..", "..", -EINVAL);
+}
+
+static void test_dns_name_endswith_one(const char *a, const char *b, int ret) {
+        assert_se(dns_name_endswith(a, b) == ret);
+}
+
+static void test_dns_name_endswith(void) {
+        test_dns_name_endswith_one("", "", true);
+        test_dns_name_endswith_one("", "xxx", false);
+        test_dns_name_endswith_one("xxx", "", true);
+        test_dns_name_endswith_one("x", "x", true);
+        test_dns_name_endswith_one("x", "y", false);
+        test_dns_name_endswith_one("x.y", "y", true);
+        test_dns_name_endswith_one("x.y", "Y", true);
+        test_dns_name_endswith_one("x.y", "x", false);
+        test_dns_name_endswith_one("x.y.z", "Z", true);
+        test_dns_name_endswith_one("x.y.z", "y.Z", true);
+        test_dns_name_endswith_one("x.y.z", "x.y.Z", true);
+        test_dns_name_endswith_one("x.y.z", "waldo", false);
+        test_dns_name_endswith_one("x.y.z.u.v.w", "y.z", false);
+        test_dns_name_endswith_one("x.y.z.u.v.w", "u.v.w", true);
+        test_dns_name_endswith_one("x.y\001.z", "waldo", -EINVAL);
+}
+
+static void test_dns_name_root(void) {
+        assert_se(dns_name_root("") == true);
+        assert_se(dns_name_root(".") == true);
+        assert_se(dns_name_root("xxx") == false);
+        assert_se(dns_name_root("xxx.") == false);
+        assert_se(dns_name_root("..") == -EINVAL);
+}
+
+static void test_dns_name_single_label(void) {
+        assert_se(dns_name_single_label("") == false);
+        assert_se(dns_name_single_label(".") == false);
+        assert_se(dns_name_single_label("..") == -EINVAL);
+        assert_se(dns_name_single_label("x") == true);
+        assert_se(dns_name_single_label("x.") == true);
+        assert_se(dns_name_single_label("xx.yy") == false);
+}
+
+int main(int argc, char *argv[]) {
+
+        test_dns_label_unescape();
+        test_dns_label_escape();
+        test_dns_name_normalize();
+        test_dns_name_equal();
+        test_dns_name_endswith();
+        test_dns_name_root();
+        test_dns_name_single_label();
+
+        return 0;
+}