resolve: add llmnr responder side for UDP and TCP

Name defending is still missing.

1 files changed, 244 insertions, 0 deletions

diff --git a/src/resolve/resolved-dns-zone.c b/src/resolve/resolved-dns-zone.c
new file mode 100644
index 000000000..2325ddfe7
--- /dev/null
+++ b/src/resolve/resolved-dns-zone.c
@@ -0,0 +1,244 @@
+/*-*- 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 "list.h"
+
+#include "resolved-dns-zone.h"
+#include "resolved-dns-domain.h"
+#include "resolved-dns-packet.h"
+
+/* Never allow more than 1K entries */
+#define ZONE_MAX 1024
+
+typedef struct DnsZoneItem DnsZoneItem;
+
+struct DnsZoneItem {
+        DnsResourceRecord *rr;
+        bool verified;
+        LIST_FIELDS(DnsZoneItem, by_key);
+        LIST_FIELDS(DnsZoneItem, by_name);
+};
+
+static void dns_zone_item_free(DnsZoneItem *i) {
+        if (!i)
+                return;
+
+        dns_resource_record_unref(i->rr);
+        free(i);
+}
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(DnsZoneItem*, dns_zone_item_free);
+
+static void dns_zone_item_remove_and_free(DnsZone *z, DnsZoneItem *i) {
+        DnsZoneItem *first;
+
+        assert(z);
+
+        if (!i)
+                return;
+
+        first = hashmap_get(z->by_key, i->rr->key);
+        LIST_REMOVE(by_key, first, i);
+        if (first)
+                assert_se(hashmap_replace(z->by_key, first->rr->key, first) >= 0);
+        else
+                hashmap_remove(z->by_key, i->rr->key);
+
+        first = hashmap_get(z->by_name, DNS_RESOURCE_KEY_NAME(i->rr->key));
+        LIST_REMOVE(by_name, first, i);
+        if (first)
+                assert_se(hashmap_replace(z->by_name, DNS_RESOURCE_KEY_NAME(first->rr->key), first) >= 0);
+        else
+                hashmap_remove(z->by_name, DNS_RESOURCE_KEY_NAME(i->rr->key));
+
+        dns_zone_item_free(i);
+}
+
+void dns_zone_flush(DnsZone *z) {
+        DnsZoneItem *i;
+
+        assert(z);
+
+        while ((i = hashmap_first(z->by_key)))
+                dns_zone_item_remove_and_free(z, i);
+
+        assert(hashmap_size(z->by_key) == 0);
+        assert(hashmap_size(z->by_name) == 0);
+
+        hashmap_free(z->by_key);
+        z->by_key = NULL;
+
+        hashmap_free(z->by_name);
+        z->by_name = NULL;
+}
+
+static DnsZoneItem* dns_zone_get(DnsZone *z, DnsResourceRecord *rr) {
+        DnsZoneItem *i;
+
+        assert(z);
+        assert(rr);
+
+        LIST_FOREACH(by_key, i, hashmap_get(z->by_key, rr->key))
+                if (dns_resource_record_equal(i->rr, rr))
+                        return i;
+
+        return NULL;
+}
+
+void dns_zone_remove_rr(DnsZone *z, DnsResourceRecord *rr) {
+        DnsZoneItem *i;
+
+        assert(z);
+        assert(rr);
+
+        i = dns_zone_get(z, rr);
+        if (i)
+                dns_zone_item_remove_and_free(z, i);
+}
+
+static int dns_zone_init(DnsZone *z) {
+        int r;
+
+        assert(z);
+
+        r = hashmap_ensure_allocated(&z->by_key, dns_resource_key_hash_func, dns_resource_key_compare_func);
+        if (r < 0)
+                return r;
+
+        r = hashmap_ensure_allocated(&z->by_name, dns_name_hash_func, dns_name_compare_func);
+        if (r < 0)
+                return r;
+
+        return 0;
+}
+
+static int dns_zone_link_item(DnsZone *z, DnsZoneItem *i) {
+        DnsZoneItem *first;
+        int r;
+
+        first = hashmap_get(z->by_key, i->rr->key);
+        if (first) {
+                LIST_PREPEND(by_key, first, i);
+                assert_se(hashmap_replace(z->by_key, first->rr->key, first) >= 0);
+        } else {
+                r = hashmap_put(z->by_key, i->rr->key, i);
+                if (r < 0)
+                        return r;
+        }
+
+        first = hashmap_get(z->by_name, DNS_RESOURCE_KEY_NAME(i->rr->key));
+        if (first) {
+                LIST_PREPEND(by_name, first, i);
+                assert_se(hashmap_replace(z->by_name, DNS_RESOURCE_KEY_NAME(first->rr->key), first) >= 0);
+        } else {
+                r = hashmap_put(z->by_name, DNS_RESOURCE_KEY_NAME(i->rr->key), i);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}
+
+int dns_zone_put(DnsZone *z, DnsResourceRecord *rr) {
+        _cleanup_(dns_zone_item_freep) DnsZoneItem *i = NULL;
+        DnsZoneItem *existing;
+        int r;
+
+        assert(z);
+        assert(rr);
+
+        existing = dns_zone_get(z, rr);
+        if (existing)
+                return 0;
+
+        r = dns_zone_init(z);
+        if (r < 0)
+                return r;
+
+        i = new0(DnsZoneItem, 1);
+        if (!i)
+                return -ENOMEM;
+
+        i->rr = dns_resource_record_ref(rr);
+
+        r = dns_zone_link_item(z, i);
+        if (r < 0)
+                return r;
+
+        i = NULL;
+        return 0;
+}
+
+int dns_zone_lookup(DnsZone *z, DnsQuestion *q, DnsAnswer **ret) {
+        _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
+        int r;
+        unsigned i, n = 0;
+        bool has_other_rrs = false;
+
+        assert(z);
+        assert(q);
+        assert(ret);
+
+        if (q->n_keys <= 0) {
+                *ret = NULL;
+                return 0;
+        }
+
+        for (i = 0; i < q->n_keys; i++) {
+                DnsZoneItem *j;
+
+                j = hashmap_get(z->by_key, q->keys[i]);
+                if (!j) {
+                        if (hashmap_get(z->by_name, DNS_RESOURCE_KEY_NAME(q->keys[i])))
+                                has_other_rrs = true;
+
+                        continue;
+                }
+
+                LIST_FOREACH(by_name, j, j)
+                        n++;
+        }
+
+        if (n <= 0) {
+                *ret = NULL;
+                return has_other_rrs;
+        }
+
+        answer = dns_answer_new(n);
+        if (!answer)
+                return -ENOMEM;
+
+        for (i = 0; i < q->n_keys; i++) {
+                DnsZoneItem *j;
+
+                j = hashmap_get(z->by_key, q->keys[i]);
+                LIST_FOREACH(by_key, j, j) {
+                        r = dns_answer_add(answer, j->rr);
+                        if (r < 0)
+                                return r;
+                }
+        }
+
+        *ret = answer;
+        answer = NULL;
+
+        return 1;
+}