nvmf: Encapsulate spdk_nvmf_host

Hide the definition of spdk_nvmf_host. Add accessors
for the necessary data.

Change-Id: I28f5b8d243cb1b299724a1dd32fcf2f2bd95e1f9
Signed-off-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-on: https://review.gerrithub.io/374870
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>

app/nvmf_tgt/nvmf_rpc.c

@@ -90,10 +90,11 @@ dump_nvmf_subsystem(struct spdk_json_write_ctx *w, struct nvmf_tgt_subsystem *tg
 	spdk_json_write_name(w, "hosts");
 	spdk_json_write_array_begin(w);
 
-	TAILQ_FOREACH(host, &subsystem->hosts, link) {
+	for (host = spdk_nvmf_subsystem_get_first_host(subsystem); host != NULL;
+	     host = spdk_nvmf_subsystem_get_next_host(subsystem, host)) {
 		spdk_json_write_object_begin(w);
 		spdk_json_write_name(w, "nqn");
-		spdk_json_write_string(w, host->nqn);
+		spdk_json_write_string(w, spdk_nvmf_host_get_nqn(host));
 		spdk_json_write_object_end(w);
 	}
 	spdk_json_write_array_end(w);

include/spdk/nvmf.h

@@ -61,6 +61,7 @@ struct spdk_nvmf_qpair;
 struct spdk_nvmf_request;
 struct spdk_bdev;
 struct spdk_nvmf_request;
+struct spdk_nvmf_host;
 
 typedef void (*spdk_nvmf_subsystem_connect_fn)(void *cb_ctx, struct spdk_nvmf_request *req);
 typedef void (*spdk_nvmf_subsystem_disconnect_fn)(void *cb_ctx, struct spdk_nvmf_qpair *qpair);
@@ -70,11 +71,6 @@ struct spdk_nvmf_listen_addr {
 	TAILQ_ENTRY(spdk_nvmf_listen_addr)	link;
 };
 
-struct spdk_nvmf_host {
-	char				*nqn;
-	TAILQ_ENTRY(spdk_nvmf_host)	link;
-};
-
 struct spdk_nvmf_subsystem_allowed_listener {
 	struct spdk_nvmf_listen_addr				*listen_addr;
 	TAILQ_ENTRY(spdk_nvmf_subsystem_allowed_listener)	link;
@@ -134,8 +130,51 @@ void spdk_nvmf_delete_subsystem(struct spdk_nvmf_subsystem *subsystem);
 
 struct spdk_nvmf_subsystem *spdk_nvmf_find_subsystem(const char *subnqn);
 
+/**
+ * Allow the given host NQN to connect to the given subsystem.
+ *
+ * \param subsystem Subsystem to add host to
+ * \param host_nqn The NQN for the host
+ * \return 0 on success. Negated errno value on failure.
+ */
+int spdk_nvmf_subsystem_add_host(struct spdk_nvmf_subsystem *subsystem,
+				 const char *hostnqn);
+
+/**
+ * Check if the given host is allowed to connect to the subsystem.
+ *
+ * \param subsystem The subsystem to query
+ * \param hostnqn The NQN of the host
+ * \return true if allowed, false if not.
+ */
 bool spdk_nvmf_subsystem_host_allowed(struct spdk_nvmf_subsystem *subsystem, const char *hostnqn);
 
+/**
+ * Return the first allowed host in a subsystem.
+ *
+ * \param subsystem Subsystem to query.
+ * \return First allowed host in this subsystem, or NULL if none allowed.
+ */
+struct spdk_nvmf_host *spdk_nvmf_subsystem_get_first_host(struct spdk_nvmf_subsystem *subsystem);
+
+/**
+ * Return the next allowed host in a subsystem.
+ *
+ * \param subsystem Subsystem to query.
+ * \param prev_host Previous host returned from this function.
+ * \return Next allowed host in this subsystem, or NULL if prev_host was the last host.
+ */
+struct spdk_nvmf_host *spdk_nvmf_subsystem_get_next_host(struct spdk_nvmf_subsystem *subsystem,
+		struct spdk_nvmf_host *prev_host);
+
+/**
+ * Get a host's NQN
+ *
+ * \param host Host to query.
+ * \return NQN of host.
+ */
+const char *spdk_nvmf_host_get_nqn(struct spdk_nvmf_host *host);
+
 struct spdk_nvmf_listen_addr *spdk_nvmf_tgt_listen(struct spdk_nvme_transport_id *trid);
 
 int spdk_nvmf_subsystem_add_listener(struct spdk_nvmf_subsystem *subsystem,
@@ -144,8 +183,7 @@ int spdk_nvmf_subsystem_add_listener(struct spdk_nvmf_subsystem *subsystem,
 bool spdk_nvmf_subsystem_listener_allowed(struct spdk_nvmf_subsystem *subsystem,
 		struct spdk_nvmf_listen_addr *listen_addr);
 
-int spdk_nvmf_subsystem_add_host(struct spdk_nvmf_subsystem *subsystem,
+
-				 const char *host_nqn);
 
 void spdk_nvmf_subsystem_poll(struct spdk_nvmf_subsystem *subsystem);
 

lib/nvmf/nvmf_internal.h

@@ -59,6 +59,11 @@ struct spdk_nvmf_tgt {
 	TAILQ_HEAD(, spdk_nvmf_transport)	transports;
 };
 
+struct spdk_nvmf_host {
+	char				*nqn;
+	TAILQ_ENTRY(spdk_nvmf_host)	link;
+};
+
 struct spdk_nvmf_poll_group {
 	struct spdk_nvmf_transport		*transport;
 	TAILQ_ENTRY(spdk_nvmf_poll_group)	link;

lib/nvmf/subsystem.c

@@ -81,29 +81,6 @@ spdk_nvmf_find_subsystem_with_cntlid(uint16_t cntlid)
 	return NULL;
 }
 
-bool
-spdk_nvmf_subsystem_host_allowed(struct spdk_nvmf_subsystem *subsystem, const char *hostnqn)
-{
-	struct spdk_nvmf_host *host;
-
-	if (!hostnqn) {
-		return false;
-	}
-
-	if (TAILQ_EMPTY(&subsystem->hosts)) {
-		/* No hosts means any host can connect */
-		return true;
-	}
-
-	TAILQ_FOREACH(host, &subsystem->hosts, link) {
-		if (strcmp(hostnqn, host->nqn) == 0) {
-			return true;
-		}
-	}
-
-	return false;
-}
-
 int
 spdk_nvmf_subsystem_start(struct spdk_nvmf_subsystem *subsystem)
 {
@@ -244,6 +221,75 @@ spdk_nvmf_delete_subsystem(struct spdk_nvmf_subsystem *subsystem)
 	free(subsystem);
 }
 
+
+int
+spdk_nvmf_subsystem_add_host(struct spdk_nvmf_subsystem *subsystem, const char *hostnqn)
+{
+	struct spdk_nvmf_host *host;
+
+	if (!spdk_nvmf_valid_nqn(hostnqn)) {
+		return -1;
+	}
+
+	host = calloc(1, sizeof(*host));
+	if (!host) {
+		return -1;
+	}
+	host->nqn = strdup(hostnqn);
+	if (!host->nqn) {
+		free(host);
+		return -1;
+	}
+
+	TAILQ_INSERT_HEAD(&subsystem->hosts, host, link);
+	g_nvmf_tgt.discovery_genctr++;
+
+	return 0;
+}
+
+bool
+spdk_nvmf_subsystem_host_allowed(struct spdk_nvmf_subsystem *subsystem, const char *hostnqn)
+{
+	struct spdk_nvmf_host *host;
+
+	if (!hostnqn) {
+		return false;
+	}
+
+	if (TAILQ_EMPTY(&subsystem->hosts)) {
+		/* No hosts means any host can connect */
+		return true;
+	}
+
+	TAILQ_FOREACH(host, &subsystem->hosts, link) {
+		if (strcmp(hostnqn, host->nqn) == 0) {
+			return true;
+		}
+	}
+
+	return false;
+}
+
+struct spdk_nvmf_host *
+spdk_nvmf_subsystem_get_first_host(struct spdk_nvmf_subsystem *subsystem)
+{
+	return TAILQ_FIRST(&subsystem->hosts);
+}
+
+
+struct spdk_nvmf_host *
+spdk_nvmf_subsystem_get_next_host(struct spdk_nvmf_subsystem *subsystem,
+				  struct spdk_nvmf_host *prev_host)
+{
+	return TAILQ_NEXT(prev_host, link);
+}
+
+const char *
+spdk_nvmf_host_get_nqn(struct spdk_nvmf_host *host)
+{
+	return host->nqn;
+}
+
 struct spdk_nvmf_listen_addr *
 spdk_nvmf_tgt_listen(struct spdk_nvme_transport_id *trid)
 {
@@ -326,31 +372,6 @@ spdk_nvmf_subsystem_listener_allowed(struct spdk_nvmf_subsystem *subsystem,
 	return false;
 }
 
-int
-spdk_nvmf_subsystem_add_host(struct spdk_nvmf_subsystem *subsystem, const char *host_nqn)
-{
-	struct spdk_nvmf_host *host;
-
-	if (!spdk_nvmf_valid_nqn(host_nqn)) {
-		return -1;
-	}
-
-	host = calloc(1, sizeof(*host));
-	if (!host) {
-		return -1;
-	}
-	host->nqn = strdup(host_nqn);
-	if (!host->nqn) {
-		free(host);
-		return -1;
-	}
-
-	TAILQ_INSERT_HEAD(&subsystem->hosts, host, link);
-	g_nvmf_tgt.discovery_genctr++;
-
-	return 0;
-}
-
 static void spdk_nvmf_ctrlr_hot_remove(void *remove_ctx)
 {
 	struct spdk_nvmf_subsystem *subsystem = (struct spdk_nvmf_subsystem *)remove_ctx;