On Thu, Aug 18, 2011 at 10:48:35AM +0200, Michal Privoznik wrote:
When spice_tls is set but listen_tls is not, we don't initialize
GnuTLS library. So any later gnutls call (e.g. during migration,
where we initialize a certificate) will access uninitialized GnuTLS
internal structs and throws an error.
Although, we might now initialize GnuTLS twice, it is safe according
to the documentation:
This function can be called many times,
but will only do something the first time.
This patch creates 2 functions: virNetTLSInit and virNetTLSDeinit
with respect to written above.
---
diff to v1:
- moved from qemu to daemon
- created special init function
daemon/libvirtd.c | 2 ++
src/rpc/virnettlscontext.c | 25 ++++++++++++++++++++++---
src/rpc/virnettlscontext.h | 3 +++
3 files changed, 27 insertions(+), 3 deletions(-)
diff --git a/daemon/libvirtd.c b/daemon/libvirtd.c
index b99c637..0530ba5 100644
--- a/daemon/libvirtd.c
+++ b/daemon/libvirtd.c
@@ -1516,6 +1516,7 @@ int main(int argc, char **argv) {
virHookCall(VIR_HOOK_DRIVER_DAEMON, "-", VIR_HOOK_DAEMON_OP_START,
0, "start", NULL);
+ virNetTLSInit();
if (daemonSetupNetworking(srv, config,
sock_file, sock_file_ro,
ipsock, privileged) < 0) {
@@ -1554,6 +1555,7 @@ cleanup:
virNetServerProgramFree(qemuProgram);
virNetServerClose(srv);
virNetServerFree(srv);
+ virNetTLSDeinit();
if (statuswrite != -1) {
if (ret != 0) {
/* Tell parent of daemon what failed */
diff --git a/src/rpc/virnettlscontext.c b/src/rpc/virnettlscontext.c
index 19a9b25..8482eaf 100644
--- a/src/rpc/virnettlscontext.c
+++ b/src/rpc/virnettlscontext.c
@@ -679,9 +679,6 @@ static virNetTLSContextPtr virNetTLSContextNew(const char *cacert,
ctxt->refs = 1;
- /* Initialise GnuTLS. */
- gnutls_global_init();
-
if ((gnutlsdebug = getenv("LIBVIRT_GNUTLS_DEBUG")) != NULL) {
int val;
if (virStrToLong_i(gnutlsdebug, NULL, 10, &val) < 0)
@@ -1399,3 +1396,25 @@ void virNetTLSSessionFree(virNetTLSSessionPtr sess)
virMutexDestroy(&sess->lock);
VIR_FREE(sess);
}
+
+/*
+ * This function MUST be called before any
+ * virNetTLS* because it initializes
+ * underlying GnuTLS library. According to
+ * it's documentation, it's safe to be called
+ * many times, but is not thread safe. Each
+ * call SHOULD be later followed by
+ * virNetTLSContextDeinit.
+ */
+void virNetTLSInit(void)
+{
+ gnutls_global_init();
+}
+
+/*
+ * See virNetTLSInit
+ */
+void virNetTLSDeinit(void)
+{
+ gnutls_global_deinit();
+}
diff --git a/src/rpc/virnettlscontext.h b/src/rpc/virnettlscontext.h
index 641d67e..99f31b9 100644
--- a/src/rpc/virnettlscontext.h
+++ b/src/rpc/virnettlscontext.h
@@ -30,6 +30,9 @@ typedef struct _virNetTLSSession virNetTLSSession;
typedef virNetTLSSession *virNetTLSSessionPtr;
+void virNetTLSInit(void);
+void virNetTLSDeinit(void);
+
virNetTLSContextPtr virNetTLSContextNewServerPath(const char *pkipath,
bool tryUserPkiPath,
const char *const*x509dnWhitelist,
I wonder about virNetTLSDeinit(), it basically call gnutls and tell
the library that we don't use it anymore. While gnutls_global_init()
might be safe, if they don't do reference counting
gnutls_global_deinit() may free up data still used by another library
under the hood.
The comment seems to imply that gnutls_global_(de)init
do reference counting and ACK in this case but if not I would
just drop the virNetTLSDeinit() part, we were not calling
gnutls_global_deinit before anyway.
ACK if ref counting in gnutls confirmed
Daniel
--
Daniel Veillard | libxml Gnome XML XSLT toolkit
http://xmlsoft.org/
daniel(a)veillard.com | Rpmfind RPM search engine
http://rpmfind.net/
http://veillard.com/ | virtualization library
http://libvirt.org/