resolved: add a generic DnsSearchDomain concept

With this change, we add a new object to resolved, "DnsSearchDomain="
which wraps a search domain. This is then used to introduce a global
search domain list, in addition to the existing per-link search domain
list which is reword to make use of this new object too.

This is preparation for implement proper unicast DNS search domain
support.

1 files changed, 223 insertions, 0 deletions

diff --git a/src/resolve/resolved-dns-search-domain.c b/src/resolve/resolved-dns-search-domain.c
new file mode 100644
index 0000000000..5d927bb2a1
--- /dev/null
+++ b/src/resolve/resolved-dns-search-domain.c
@@ -0,0 +1,223 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2015 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 "alloc-util.h"
+#include "dns-domain.h"
+#include "resolved-dns-search-domain.h"
+
+int dns_search_domain_new(
+                Manager *m,
+                DnsSearchDomain **ret,
+                DnsSearchDomainType type,
+                Link *l,
+                const char *name) {
+
+        _cleanup_free_ char *normalized = NULL;
+        DnsSearchDomain *d, *tail;
+        int r;
+
+        assert(m);
+        assert((type == DNS_SEARCH_DOMAIN_LINK) == !!l);
+        assert(name);
+
+        r = dns_name_normalize(name, &normalized);
+        if (r < 0)
+                return r;
+
+        r = dns_name_root(normalized);
+        if (r < 0)
+                return r;
+        if (r > 0)
+                return -EINVAL;
+
+        d = new0(DnsSearchDomain, 1);
+        if (!d)
+                return -ENOMEM;
+
+        d->n_ref = 1;
+        d->manager = m;
+        d->type = type;
+        d->name = normalized;
+        normalized = NULL;
+
+        switch (type) {
+
+        case DNS_SEARCH_DOMAIN_LINK:
+                d->link = l;
+                LIST_FIND_TAIL(domains, l->search_domains, tail);
+                LIST_INSERT_AFTER(domains, l->search_domains, tail, d);
+                break;
+
+        case DNS_SERVER_SYSTEM:
+                LIST_FIND_TAIL(domains, m->search_domains, tail);
+                LIST_INSERT_AFTER(domains, m->search_domains, tail, d);
+                break;
+
+        default:
+                assert_not_reached("Unknown search domain type");
+        }
+
+        d->linked = true;
+
+        if (ret)
+                *ret = d;
+
+        return 0;
+}
+
+DnsSearchDomain* dns_search_domain_ref(DnsSearchDomain *d) {
+        if (!d)
+                return NULL;
+
+        assert(d->n_ref > 0);
+        d->n_ref++;
+
+        return d;
+}
+
+DnsSearchDomain* dns_search_domain_unref(DnsSearchDomain *d) {
+        if (!d)
+                return NULL;
+
+        assert(d->n_ref > 0);
+        d->n_ref--;
+
+        if (d->n_ref > 0)
+                return NULL;
+
+        free(d->name);
+        free(d);
+
+        return NULL;
+}
+
+void dns_search_domain_unlink(DnsSearchDomain *d) {
+        assert(d);
+        assert(d->manager);
+
+        if (!d->linked)
+                return;
+
+        switch (d->type) {
+
+        case DNS_SEARCH_DOMAIN_LINK:
+                assert(d->link);
+                LIST_REMOVE(domains, d->link->search_domains, d);
+                break;
+
+        case DNS_SEARCH_DOMAIN_SYSTEM:
+                LIST_REMOVE(domains, d->manager->search_domains, d);
+                break;
+        }
+
+        d->linked = false;
+
+        dns_search_domain_unref(d);
+}
+
+void dns_search_domain_move_back_and_unmark(DnsSearchDomain *d) {
+        DnsSearchDomain *tail;
+
+        assert(d);
+
+        if (!d->marked)
+                return;
+
+        d->marked = false;
+
+        if (!d->linked || !d->domains_next)
+                return;
+
+        switch (d->type) {
+
+        case DNS_SEARCH_DOMAIN_LINK:
+                assert(d->link);
+                LIST_FIND_TAIL(domains, d, tail);
+                LIST_REMOVE(domains, d->link->search_domains, d);
+                LIST_INSERT_AFTER(domains, d->link->search_domains, tail, d);
+                break;
+
+        case DNS_SEARCH_DOMAIN_SYSTEM:
+                LIST_FIND_TAIL(domains, d, tail);
+                LIST_REMOVE(domains, d->manager->search_domains, d);
+                LIST_INSERT_AFTER(domains, d->manager->search_domains, tail, d);
+                break;
+
+        default:
+                assert_not_reached("Unknown search domain type");
+        }
+}
+
+void dns_search_domain_unlink_all(DnsSearchDomain *first) {
+        DnsSearchDomain *next;
+
+        if (!first)
+                return;
+
+        next = first->domains_next;
+        dns_search_domain_unlink(first);
+
+        dns_search_domain_unlink_all(next);
+}
+
+void dns_search_domain_unlink_marked(DnsSearchDomain *first) {
+        DnsSearchDomain *next;
+
+        if (!first)
+                return;
+
+        next = first->domains_next;
+
+        if (first->marked)
+                dns_search_domain_unlink(first);
+
+        dns_search_domain_unlink_marked(next);
+}
+
+void dns_search_domain_mark_all(DnsSearchDomain *first) {
+        if (!first)
+                return;
+
+        first->marked = true;
+        dns_search_domain_mark_all(first->domains_next);
+}
+
+int dns_search_domain_find(DnsSearchDomain *first, const char *name, DnsSearchDomain **ret) {
+        DnsSearchDomain *d;
+        int r;
+
+        assert(name);
+        assert(ret);
+
+        LIST_FOREACH(domains, d, first) {
+
+                r = dns_name_equal(name, d->name);
+                if (r < 0)
+                        return r;
+                if (r > 0) {
+                        *ret = d;
+                        return 1;
+                }
+        }
+
+        *ret = NULL;
+        return 0;
+}