swig: fix bugs introduced in libnvmf_context refactor

Three bugs were introduced when libnvmf_context replaced the old
libnvme_fabrics_config parameter in the connect/create flow:

1. The %pythonappend GC guard for connect() had a stale signature that
   still included the removed fctx parameter. SWIG silently ignores a
   mismatched %pythonappend, so self.__host = h never ran, leaving a
   latent use-after-free where Python could collect the host object
   while the ctrl was still alive.

2. The duplicate_connect check in connect() had an inverted condition
   (missing !) and belonged in the library, not the binding. Move it
   to libnvmf_add_ctrl() in fabrics.c where it applies uniformly to
   all callers, C and Python alike.

3. fctx_set_fabrics_config was missing its %rename directive, exposing
   it to Python as fctx.fctx_set_fabrics_config() instead of
   fctx.set_fabrics_config() like all other libnvmf_context methods.

Signed-off-by: Martin Belanger <[email protected]>
Assisted-by: Claude Sonnet 4.6 <[email protected]>

Author: Martin Belanger

libnvme/libnvme/nvme.i

@@ -443,6 +443,7 @@ struct libnvme_ns {
 %rename(set_connection)     libnvmf_context::fctx_set_connection;
 %rename(set_persistent)     libnvmf_context::fctx_set_persistent;
 %rename(set_device)         libnvmf_context::fctx_set_device;
+%rename(set_fabrics_config) libnvmf_context::fctx_set_fabrics_config;
 
 struct libnvmf_context {};
 
@@ -725,8 +726,7 @@ struct libnvmf_context {};
 	}
 %};
 
-%pythonappend libnvme_ctrl::connect(struct libnvme_host *h,
-				 struct libnvmf_context *fctx) {
+%pythonappend libnvme_ctrl::connect(struct libnvme_host *h) {
     self.__host = h  # Keep a reference to parent to ensure ctrl obj gets GCed before host}
 %pythonappend libnvme_ctrl::init(struct libnvme_host *h, int instance) {
     self.__host = h  # Keep a reference to parent to ensure ctrl obj gets GCed before host}
@@ -756,13 +756,6 @@ struct libnvmf_context {};
 
 	void connect(struct libnvme_host *h) {
 		int ret;
-		const char *dev;
-
-		dev = libnvme_ctrl_get_name($self);
-		if (dev && $self->cfg.duplicate_connect) {
-			connect_err = -ENVME_CONNECT_ALREADY;
-			return;
-		}
 
 		Py_BEGIN_ALLOW_THREADS  /* Release Python GIL */
 		ret = libnvmf_add_ctrl(h, $self);

libnvme/src/nvme/fabrics.c

@@ -1102,6 +1102,10 @@ __public int libnvmf_add_ctrl(libnvme_host_t h, libnvme_ctrl_t c)
 	__cleanup_free char *argstr = NULL;
 	int ret;
 
+	/* Are duplicate connections allowed on existing controller */
+	if (libnvme_ctrl_get_name(c) && !c->cfg.duplicate_connect)
+		return -ENVME_CONNECT_ALREADY;
+
 	/* apply configuration from config file (JSON) */
 	s = libnvme_lookup_subsystem(h, NULL, libnvme_ctrl_get_subsysnqn(c));
 	if (s) {