X-Git-Url: http://git.ipfire.org/?a=blobdiff_plain;f=src%2Fresolve%2Fresolved-dns-server.c;h=2ff5b192df691a5646fa4689200c7d7f7f0e123b;hb=da1d9fc2cc3bf6f89c037e11a584d444d0c3a2a8;hp=734441bccdf545fc17935e2717ceef2dd09c3c72;hpb=0dd25fb9f005d8ab7ac4bc10a609d00569f8c56a;p=thirdparty%2Fsystemd.git

diff --git a/src/resolve/resolved-dns-server.c b/src/resolve/resolved-dns-server.c
index 734441bccdf..2ff5b192df6 100644
--- a/src/resolve/resolved-dns-server.c
+++ b/src/resolve/resolved-dns-server.c
@@ -19,12 +19,18 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include "siphash24.h"
+
 #include "resolved-dns-server.h"
 
+/* After how much time to repeat classic DNS requests */
+#define DNS_TIMEOUT_MIN_USEC (500 * USEC_PER_MSEC)
+#define DNS_TIMEOUT_MAX_USEC (5 * USEC_PER_SEC)
+
 int dns_server_new(
                 Manager *m,
                 DnsServer **ret,
-                DnsServerSource source,
+                DnsServerType type,
                 Link *l,
                 int family,
                 const union in_addr_union *in_addr) {
@@ -32,67 +38,127 @@ int dns_server_new(
         DnsServer *s, *tail;
 
         assert(m);
+        assert((type == DNS_SERVER_LINK) == !!l);
         assert(in_addr);
-        assert(source < _DNS_SERVER_SOURCE_MAX);
 
         s = new0(DnsServer, 1);
         if (!s)
                 return -ENOMEM;
 
-        s->source = source;
+        s->n_ref = 1;
+        s->type = type;
         s->family = family;
         s->address = *in_addr;
+        s->resend_timeout = DNS_TIMEOUT_MIN_USEC;
 
-        if (source == DNS_SERVER_LINK) {
-                assert(l);
-                LIST_FIND_TAIL(servers, l->link_dns_servers, tail);
-                LIST_INSERT_AFTER(servers, l->link_dns_servers, tail, s);
-                s->link = l;
-        } else if (source == DNS_SERVER_DHCP) {
-                assert(l);
-                LIST_FIND_TAIL(servers, l->dhcp_dns_servers, tail);
-                LIST_INSERT_AFTER(servers, l->dhcp_dns_servers, tail, s);
+        if (type == DNS_SERVER_LINK) {
+                LIST_FIND_TAIL(servers, l->dns_servers, tail);
+                LIST_INSERT_AFTER(servers, l->dns_servers, tail, s);
                 s->link = l;
-        } else {
-                assert(!l);
+        } else if (type == DNS_SERVER_SYSTEM) {
                 LIST_FIND_TAIL(servers, m->dns_servers, tail);
                 LIST_INSERT_AFTER(servers, m->dns_servers, tail, s);
-        }
+        } else if (type == DNS_SERVER_FALLBACK) {
+                LIST_FIND_TAIL(servers, m->fallback_dns_servers, tail);
+                LIST_INSERT_AFTER(servers, m->fallback_dns_servers, tail, s);
+        } else
+                assert_not_reached("Unknown server type");
 
         s->manager = m;
 
+        /* A new DNS server that isn't fallback is added and the one
+         * we used so far was a fallback one? Then let's try to pick
+         * the new one */
+        if (type != DNS_SERVER_FALLBACK &&
+            m->current_dns_server &&
+            m->current_dns_server->type == DNS_SERVER_FALLBACK)
+                manager_set_dns_server(m, NULL);
+
         if (ret)
                 *ret = s;
 
         return 0;
 }
 
-DnsServer* dns_server_free(DnsServer *s)  {
+DnsServer* dns_server_ref(DnsServer *s)  {
         if (!s)
                 return NULL;
 
-        if (s->source == DNS_SERVER_LINK) {
+        assert(s->n_ref > 0);
 
-                if (s->link)
-                        LIST_REMOVE(servers, s->link->link_dns_servers, s);
-        } else if (s->source == DNS_SERVER_DHCP) {
+        s->n_ref ++;
 
-                if (s->link)
-                        LIST_REMOVE(servers, s->link->dhcp_dns_servers, s);
-
-        } else if (s->source == DNS_SERVER_SYSTEM) {
+        return s;
+}
 
-                if (s->manager)
-                        LIST_REMOVE(servers, s->manager->dns_servers, s);
-        }
+static DnsServer* dns_server_free(DnsServer *s)  {
+        if (!s)
+                return NULL;
 
         if (s->link && s->link->current_dns_server == s)
-                s->link->current_dns_server = NULL;
+                link_set_dns_server(s->link, NULL);
 
         if (s->manager && s->manager->current_dns_server == s)
-                s->manager->current_dns_server = NULL;
+                manager_set_dns_server(s->manager, NULL);
 
         free(s);
 
         return NULL;
 }
+
+DnsServer* dns_server_unref(DnsServer *s)  {
+        if (!s)
+                return NULL;
+
+        assert(s->n_ref > 0);
+
+        if (s->n_ref == 1)
+                dns_server_free(s);
+        else
+                s->n_ref --;
+
+        return NULL;
+}
+
+void dns_server_packet_received(DnsServer *s, usec_t rtt) {
+        assert(s);
+
+        if (rtt > s->max_rtt) {
+                s->max_rtt = rtt;
+                s->resend_timeout = MIN(MAX(DNS_TIMEOUT_MIN_USEC, s->max_rtt * 2),
+                                        DNS_TIMEOUT_MAX_USEC);
+        }
+}
+
+void dns_server_packet_lost(DnsServer *s, usec_t usec) {
+        assert(s);
+
+        if (s->resend_timeout <= usec)
+                s->resend_timeout = MIN(s->resend_timeout * 2, DNS_TIMEOUT_MAX_USEC);
+}
+
+static unsigned long dns_server_hash_func(const void *p, const uint8_t hash_key[HASH_KEY_SIZE]) {
+        const DnsServer *s = p;
+        uint64_t u;
+
+        siphash24((uint8_t*) &u, &s->address, FAMILY_ADDRESS_SIZE(s->family), hash_key);
+        u = u * hash_key[0] + u + s->family;
+
+        return u;
+}
+
+static int dns_server_compare_func(const void *a, const void *b) {
+        const DnsServer *x = a, *y = b;
+
+        if (x->family < y->family)
+                return -1;
+        if (x->family > y->family)
+                return 1;
+
+        return memcmp(&x->address, &y->address, FAMILY_ADDRESS_SIZE(x->family));
+}
+
+const struct hash_ops dns_server_hash_ops = {
+        .hash = dns_server_hash_func,
+        .compare = dns_server_compare_func
+};