The virNetServerClient object had a hardcoded limit of 10 requests per client. Extend constructor to allow it to be passed in as a configurable variable. Wire this up to the 'max_client_requests' config parameter in libvirtd * daemon/libvirtd.c: Pass max_client_requests into services * src/rpc/virnetserverservice.c, src/rpc/virnetserverservice.h: Pass nrequests_client_max to clients * src/rpc/virnetserverclient.c, src/rpc/virnetserverclient.h: Allow configurable request limit --- daemon/libvirtd.c | 4 ++++ src/rpc/virnetserverclient.c | 3 ++- src/rpc/virnetserverclient.h | 1 + src/rpc/virnetserverservice.c | 6 ++++++ src/rpc/virnetserverservice.h | 2 ++ 5 files changed, 15 insertions(+), 1 deletions(-) diff --git a/daemon/libvirtd.c b/daemon/libvirtd.c index d1f80e4..118aa92 100644 --- a/daemon/libvirtd.c +++ b/daemon/libvirtd.c @@ -486,6 +486,7 @@ static int daemonSetupNetworking(virNetServerPtr srv, unix_sock_gid, config->auth_unix_rw, false, + config->max_client_requests, NULL))) goto error; if (sock_path_ro && @@ -494,6 +495,7 @@ static int daemonSetupNetworking(virNetServerPtr srv, unix_sock_gid, config->auth_unix_ro, true, + config->max_client_requests, NULL))) goto error; @@ -509,6 +511,7 @@ static int daemonSetupNetworking(virNetServerPtr srv, config->tcp_port, config->auth_tcp, false, + config->max_client_requests, NULL))) goto error; @@ -543,6 +546,7 @@ static int daemonSetupNetworking(virNetServerPtr srv, config->tls_port, config->auth_tls, false, + config->max_client_requests, ctxt))) { virNetTLSContextFree(ctxt); goto error; diff --git a/src/rpc/virnetserverclient.c b/src/rpc/virnetserverclient.c index 57a3446..aac4c3c 100644 --- a/src/rpc/virnetserverclient.c +++ b/src/rpc/virnetserverclient.c @@ -282,6 +282,7 @@ virNetServerClientCheckAccess(virNetServerClientPtr client) virNetServerClientPtr virNetServerClientNew(virNetSocketPtr sock, int auth, bool readonly, + size_t nrequests_max, virNetTLSContextPtr tls) { virNetServerClientPtr client; @@ -301,7 +302,7 @@ virNetServerClientPtr virNetServerClientNew(virNetSocketPtr sock, client->auth = auth; client->readonly = readonly; client->tlsCtxt = tls; - client->nrequests_max = 10; /* XXX */ + client->nrequests_max = nrequests_max; if (tls) virNetTLSContextRef(tls); diff --git a/src/rpc/virnetserverclient.h b/src/rpc/virnetserverclient.h index 0994890..66510c3 100644 --- a/src/rpc/virnetserverclient.h +++ b/src/rpc/virnetserverclient.h @@ -41,6 +41,7 @@ typedef int (*virNetServerClientFilterFunc)(virNetServerClientPtr client, virNetServerClientPtr virNetServerClientNew(virNetSocketPtr sock, int auth, bool readonly, + size_t nrequests_max, virNetTLSContextPtr tls); int virNetServerClientAddFilter(virNetServerClientPtr client, diff --git a/src/rpc/virnetserverservice.c b/src/rpc/virnetserverservice.c index e5a47b0..e84f72c 100644 --- a/src/rpc/virnetserverservice.c +++ b/src/rpc/virnetserverservice.c @@ -39,6 +39,7 @@ struct _virNetServerService { int auth; bool readonly; + size_t nrequests_client_max; virNetTLSContextPtr tls; @@ -65,6 +66,7 @@ static void virNetServerServiceAccept(virNetSocketPtr sock, if (!(client = virNetServerClientNew(clientsock, svc->auth, svc->readonly, + svc->nrequests_client_max, svc->tls))) goto error; @@ -88,6 +90,7 @@ virNetServerServicePtr virNetServerServiceNewTCP(const char *nodename, const char *service, int auth, bool readonly, + size_t nrequests_client_max, virNetTLSContextPtr tls) { virNetServerServicePtr svc; @@ -99,6 +102,7 @@ virNetServerServicePtr virNetServerServiceNewTCP(const char *nodename, svc->refs = 1; svc->auth = auth; svc->readonly = readonly; + svc->nrequests_client_max = nrequests_client_max; svc->tls = tls; if (tls) virNetTLSContextRef(tls); @@ -138,6 +142,7 @@ virNetServerServicePtr virNetServerServiceNewUNIX(const char *path, gid_t grp, int auth, bool readonly, + size_t nrequests_client_max, virNetTLSContextPtr tls) { virNetServerServicePtr svc; @@ -149,6 +154,7 @@ virNetServerServicePtr virNetServerServiceNewUNIX(const char *path, svc->refs = 1; svc->auth = auth; svc->readonly = readonly; + svc->nrequests_client_max = nrequests_client_max; svc->tls = tls; if (tls) virNetTLSContextRef(tls); diff --git a/src/rpc/virnetserverservice.h b/src/rpc/virnetserverservice.h index 378fa0b..9357598 100644 --- a/src/rpc/virnetserverservice.h +++ b/src/rpc/virnetserverservice.h @@ -40,12 +40,14 @@ virNetServerServicePtr virNetServerServiceNewTCP(const char *nodename, const char *service, int auth, bool readonly, + size_t nrequests_client_max, virNetTLSContextPtr tls); virNetServerServicePtr virNetServerServiceNewUNIX(const char *path, mode_t mask, gid_t grp, int auth, bool readonly, + size_t nrequests_client_max, virNetTLSContextPtr tls); int virNetServerServiceGetPort(virNetServerServicePtr svc); -- 1.7.4.4

To save on memory reallocation, virNetMessage instances that have been transmitted, may be reused for a subsequent incoming message. We forgot to clear out the old data of the message fully, which caused later confusion upon read. * src/rpc/virnetserverclient.c: memset entire message before reusing it --- src/rpc/virnetserverclient.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/src/rpc/virnetserverclient.c b/src/rpc/virnetserverclient.c index aac4c3c..5c23cf2 100644 --- a/src/rpc/virnetserverclient.c +++ b/src/rpc/virnetserverclient.c @@ -837,6 +837,7 @@ virNetServerClientDispatchWrite(virNetServerClientPtr client) client->nrequests < client->nrequests_max) { /* Ready to recv more messages */ client->rx = msg; + memset(client->rx, 0, sizeof(*client->rx)); client->rx->bufferLength = VIR_NET_MESSAGE_LEN_MAX; msg = NULL; client->nrequests++; -- 1.7.4.4

The stream code was reusing a stream message object before it was removed from the linked list of filtered messages. This caused any later queued messages to be completely lost. * daemon/stream.c: Delay reuse of stream message until after it is removed from the queue --- daemon/stream.c | 20 ++++++++++++++++---- 1 files changed, 16 insertions(+), 4 deletions(-) diff --git a/daemon/stream.c b/daemon/stream.c index e4fcf90..685cee2 100644 --- a/daemon/stream.c +++ b/daemon/stream.c @@ -456,10 +456,6 @@ daemonStreamHandleWriteData(virNetServerClientPtr client, /* Partial write, so indicate we have more todo later */ if (msg->bufferOffset < msg->bufferLength) return 1; - - /* A dummy 'send' just to free up 'msg' object */ - memset(msg, 0, sizeof(*msg)); - return virNetServerClientSendMessage(client, msg); } else if (ret == -2) { /* Blocking, so indicate we have more todo later */ return 1; @@ -603,6 +599,22 @@ daemonStreamHandleWrite(virNetServerClientPtr client, virNetServerClientMarkClose(client); return -1; } + + /* 'CONTINUE' messages don't send a reply (unless error + * occurred), so to release the 'msg' object we need to + * send a fake zero-length reply. Nothing actually gets + * onto the wire, but this causes the client to reset + * its active request count / throttling + */ + if (msg->header.status == VIR_NET_CONTINUE) { + memset(msg, 0, sizeof(*msg)); + msg->header.type = VIR_NET_REPLY; + if (virNetServerClientSendMessage(client, msg) < 0) { + virNetMessageFree(msg); + virNetServerClientMarkClose(client); + return -1; + } + } } return 0; -- 1.7.4.4