daemon: Introduce max_anonymous_clients

https://bugzilla.redhat.com/show_bug.cgi?id=992980

This config tunable allows users to determine the maximum number of
accepted but yet not authenticated users.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>

diff --git a/daemon/libvirtd-config.c b/daemon/libvirtd-config.c
index 856a03872672a2e58d0705562f4fa1dd81c67f2b..21e19e0dce27bcd915bf5aa2c6b67f06b87a891a 100644 (file)
--- a/daemon/libvirtd-config.c
+++ b/daemon/libvirtd-config.c
@@ -258,7 +258,8 @@ daemonConfigNew(bool privileged ATTRIBUTE_UNUSED)
 
     data->min_workers = 5;
     data->max_workers = 20;
-    data->max_clients = 20;
+    data->max_clients = 5000;
+    data->max_anonymous_clients = 20;
 
     data->prio_workers = 5;
 
@@ -415,6 +416,7 @@ daemonConfigLoadOptions(struct daemonConfig *data,
     GET_CONF_INT(conf, filename, max_workers);
     GET_CONF_INT(conf, filename, max_clients);
     GET_CONF_INT(conf, filename, max_queued_clients);
+    GET_CONF_INT(conf, filename, max_anonymous_clients);
 
     GET_CONF_INT(conf, filename, prio_workers);
 

diff --git a/daemon/libvirtd-config.h b/daemon/libvirtd-config.h
index 0829273db412b20362bef9f43bc6b89bb165ea64..8d3d085ae25515164dec8faa2658511afd96e73d 100644 (file)
--- a/daemon/libvirtd-config.h
+++ b/daemon/libvirtd-config.h
@@ -64,6 +64,7 @@ struct daemonConfig {
     int max_workers;
     int max_clients;
     int max_queued_clients;
+    int max_anonymous_clients;
 
     int prio_workers;
 

diff --git a/daemon/libvirtd.aug b/daemon/libvirtd.aug
index 70fce5c08912829fe3c06c5fadc4800d9e8e1764..5a0807c368bef74fdc74a5934969ce40cf5ba1cc 100644 (file)
--- a/daemon/libvirtd.aug
+++ b/daemon/libvirtd.aug
@@ -57,6 +57,7 @@ module Libvirtd =
                         | int_entry "max_workers"
                         | int_entry "max_clients"
                         | int_entry "max_queued_clients"
+                        | int_entry "max_anonymous_clients"
                         | int_entry "max_requests"
                         | int_entry "max_client_requests"
                         | int_entry "prio_workers"

diff --git a/daemon/libvirtd.c b/daemon/libvirtd.c
index 27c4fff6795f4d98a03ca366aabaf462b17b61d3..83d45c69fdfcf32093eca269fdebb3ef51bb41fb 100644 (file)
--- a/daemon/libvirtd.c
+++ b/daemon/libvirtd.c
@@ -1383,6 +1383,7 @@ int main(int argc, char **argv) {
                                 config->max_workers,
                                 config->prio_workers,
                                 config->max_clients,
+                                config->max_anonymous_clients,
                                 config->keepalive_interval,
                                 config->keepalive_count,
                                 !!config->keepalive_required,

diff --git a/daemon/libvirtd.conf b/daemon/libvirtd.conf
index 073c1784fa8c38a7995a6d9385c1b78282b7a469..64c215d6c3b25cbb8bceb17b1438072b78f6dc7b 100644 (file)
--- a/daemon/libvirtd.conf
+++ b/daemon/libvirtd.conf
@@ -255,7 +255,7 @@
 
 # The maximum number of concurrent client connections to allow
 # over all sockets combined.
-#max_clients = 20
+#max_clients = 5000
 
 # The maximum length of queue of connections waiting to be
 # accepted by the daemon. Note, that some protocols supporting
@@ -263,6 +263,10 @@
 # connection succeeds.
 #max_queued_clients = 1000
 
+# The maximum length of queue of accepted but not yet not
+# authenticated clients. The default value is zero, meaning
+# the feature is disabled.
+#max_anonymous_clients = 20
 
 # The minimum limit sets the number of workers to start up
 # initially. If the number of active clients exceeds this,

diff --git a/daemon/test_libvirtd.aug.in b/daemon/test_libvirtd.aug.in
index a7e8515c6e1e1c9e33b24b1b9995d71100ddafce..37ff33d6032bca3ee04a4a8318ac5b12c4c3d095 100644 (file)
--- a/daemon/test_libvirtd.aug.in
+++ b/daemon/test_libvirtd.aug.in
@@ -34,8 +34,9 @@ module Test_libvirtd =
              { "1" = "joe@EXAMPLE.COM" }
              { "2" = "fred@EXAMPLE.COM" }
         }
-        { "max_clients" = "20" }
+        { "max_clients" = "5000" }
         { "max_queued_clients" = "1000" }
+        { "max_anonymous_clients" = "20" }
         { "min_workers" = "5" }
         { "max_workers" = "20" }
         { "prio_workers" = "5" }

diff --git a/src/locking/lock_daemon.c b/src/locking/lock_daemon.c
index 7dc4292a9255696eba55bc23dd1efe84e4ee122b..89fa93963c0f27146d1a1b7a995db41e0a4a9a26 100644 (file)
--- a/src/locking/lock_daemon.c
+++ b/src/locking/lock_daemon.c
@@ -145,7 +145,7 @@ virLockDaemonNew(virLockDaemonConfigPtr config, bool privileged)
     }
 
     if (!(lockd->srv = virNetServerNew(1, 1, 0, config->max_clients,
-                                       -1, 0,
+                                       config->max_clients, -1, 0,
                                        false, NULL,
                                        virLockDaemonClientNew,
                                        virLockDaemonClientPreExecRestart,

diff --git a/src/lxc/lxc_controller.c b/src/lxc/lxc_controller.c
index 5ca960f13e53501315b28f9086eaa389475b8feb..ab140f1dd32803cc3b195ba57a21fd1ea825e6d1 100644 (file)
--- a/src/lxc/lxc_controller.c
+++ b/src/lxc/lxc_controller.c
@@ -737,7 +737,7 @@ static int virLXCControllerSetupServer(virLXCControllerPtr ctrl)
         return -1;
 
     if (!(ctrl->server = virNetServerNew(0, 0, 0, 1,
-                                         -1, 0, false,
+                                         0, -1, 0, false,
                                          NULL,
                                          virLXCControllerClientPrivateNew,
                                          NULL,

diff --git a/src/rpc/virnetserver.c b/src/rpc/virnetserver.c
index 683b06379a1dc0aef4e6f9b4f0a75390dac51a0e..dfa3565924bec7df744c247ceffb9504f2adf88f 100644 (file)
--- a/src/rpc/virnetserver.c
+++ b/src/rpc/virnetserver.c
@@ -92,6 +92,7 @@ struct _virNetServer {
     virNetServerClientPtr *clients;     /* Clients */
     size_t nclients_max;                /* Max allowed clients count */
     size_t nclients_unauth;             /* Unauthenticated clients count */
+    size_t nclients_unauth_max;         /* Max allowed unauth clients count */
 
     int keepaliveInterval;
     unsigned int keepaliveCount;
@@ -279,6 +280,14 @@ static int virNetServerAddClient(virNetServerPtr srv,
     if (virNetServerClientNeedAuth(client))
         virNetServerTrackPendingAuthLocked(srv);
 
+    if (srv->nclients_unauth_max &&
+        srv->nclients_unauth == srv->nclients_unauth_max) {
+        /* Temporarily stop accepting new clients */
+        VIR_DEBUG("Temporarily suspending services "
+                  "due to max_anonymous_clients");
+        virNetServerUpdateServicesLocked(srv, false);
+    }
+
     if (srv->nclients == srv->nclients_max) {
         /* Temporarily stop accepting new clients */
         VIR_DEBUG("Temporarily suspending services due to max_clients");
@@ -362,6 +371,7 @@ virNetServerPtr virNetServerNew(size_t min_workers,
                                 size_t max_workers,
                                 size_t priority_workers,
                                 size_t max_clients,
+                                size_t max_anonymous_clients,
                                 int keepaliveInterval,
                                 unsigned int keepaliveCount,
                                 bool keepaliveRequired,
@@ -388,6 +398,7 @@ virNetServerPtr virNetServerNew(size_t min_workers,
         goto error;
 
     srv->nclients_max = max_clients;
+    srv->nclients_unauth_max = max_anonymous_clients;
     srv->keepaliveInterval = keepaliveInterval;
     srv->keepaliveCount = keepaliveCount;
     srv->keepaliveRequired = keepaliveRequired;
@@ -457,6 +468,7 @@ virNetServerPtr virNetServerNewPostExecRestart(virJSONValuePtr object,
     unsigned int max_workers;
     unsigned int priority_workers;
     unsigned int max_clients;
+    unsigned int max_anonymous_clients;
     unsigned int keepaliveInterval;
     unsigned int keepaliveCount;
     bool keepaliveRequired;
@@ -482,6 +494,13 @@ virNetServerPtr virNetServerNewPostExecRestart(virJSONValuePtr object,
                        _("Missing max_clients data in JSON document"));
         goto error;
     }
+    if (virJSONValueObjectHasKey(object, "max_anonymous_clients") &&
+        virJSONValueObjectGetNumberUint(object, "max_anonymous_clients",
+                                        &max_anonymous_clients) < 0) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("Malformed max_anonymous_clients data in JSON document"));
+        goto error;
+    }
     if (virJSONValueObjectGetNumberUint(object, "keepaliveInterval", &keepaliveInterval) < 0) {
         virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                        _("Missing keepaliveInterval data in JSON document"));
@@ -507,6 +526,7 @@ virNetServerPtr virNetServerNewPostExecRestart(virJSONValuePtr object,
 
     if (!(srv = virNetServerNew(min_workers, max_clients,
                                 priority_workers, max_clients,
+                                max_anonymous_clients,
                                 keepaliveInterval, keepaliveCount,
                                 keepaliveRequired, mdnsGroupName,
                                 clientPrivNew, clientPrivPreExecRestart,
@@ -625,6 +645,12 @@ virJSONValuePtr virNetServerPreExecRestart(virNetServerPtr srv)
                        _("Cannot set max_clients data in JSON document"));
         goto error;
     }
+    if (virJSONValueObjectAppendNumberUint(object, "max_anonymous_clients",
+                                           srv->nclients_unauth_max) < 0) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("Cannot set max_anonymous_clients data in JSON document"));
+        goto error;
+    }
     if (virJSONValueObjectAppendNumberUint(object, "keepaliveInterval", srv->keepaliveInterval) < 0) {
         virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                        _("Cannot set keepaliveInterval data in JSON document"));
@@ -1068,6 +1094,34 @@ void virNetServerUpdateServices(virNetServerPtr srv,
     virObjectUnlock(srv);
 }
 
+/**
+ * virNetServerCheckLimits:
+ * @srv: server to check limits on
+ *
+ * Check if limits like max_clients or max_anonymous_clients
+ * are satisfied and if so, re-enable accepting new clients.
+ * The @srv must be locked when this function is called.
+ */
+static void
+virNetServerCheckLimits(virNetServerPtr srv)
+{
+    /* Enable services if we can accept a new client.
+     * The new client can be accepted if both max_clients and
+     * max_anonymous_clients wouldn't get overcommitted by
+     * accepting it. */
+    VIR_DEBUG("Considering re-enabling services: "
+              "nclients=%zu nclients_max=%zu "
+              "nclients_unauth=%zu nclients_unauth_max=%zu",
+              srv->nclients, srv->nclients_max,
+              srv->nclients_unauth, srv->nclients_unauth_max);
+    if (srv->nclients < srv->nclients_max &&
+        (!srv->nclients_unauth_max ||
+         srv->nclients_unauth < srv->nclients_unauth_max)) {
+        /* Now it makes sense to accept() a new client. */
+        VIR_DEBUG("Re-enabling services");
+        virNetServerUpdateServicesLocked(srv, true);
+    }
+}
 
 void virNetServerRun(virNetServerPtr srv)
 {
@@ -1142,13 +1196,7 @@ void virNetServerRun(virNetServerPtr srv)
                 if (virNetServerClientNeedAuth(client))
                     virNetServerTrackCompletedAuthLocked(srv);
 
-                /* Enable services if we can accept a new client.
-                 * The new client can be accepted if we are at the limit. */
-                if (srv->nclients == srv->nclients_max - 1) {
-                    /* Now it makes sense to accept() a new client. */
-                    VIR_DEBUG("Re-enabling services");
-                    virNetServerUpdateServicesLocked(srv, true);
-                }
+                virNetServerCheckLimits(srv);
 
                 virObjectUnlock(srv);
                 virObjectUnref(client);
@@ -1265,6 +1313,7 @@ size_t virNetServerTrackCompletedAuth(virNetServerPtr srv)
     size_t ret;
     virObjectLock(srv);
     ret = virNetServerTrackCompletedAuthLocked(srv);
+    virNetServerCheckLimits(srv);
     virObjectUnlock(srv);
     return ret;
 }

diff --git a/src/rpc/virnetserver.h b/src/rpc/virnetserver.h
index b56540cfedc523b1a0042990999b321a09c4faf8..8c5ae072db28f77201e563971351c861c5cf1854 100644 (file)
--- a/src/rpc/virnetserver.h
+++ b/src/rpc/virnetserver.h
@@ -39,6 +39,7 @@ virNetServerPtr virNetServerNew(size_t min_workers,
                                 size_t max_workers,
                                 size_t priority_workers,
                                 size_t max_clients,
+                                size_t max_anonymous_clients,
                                 int keepaliveInterval,
                                 unsigned int keepaliveCount,
                                 bool keepaliveRequired,