/*-
 *   BSD LICENSE
 *
 *   Copyright (c) Intel Corporation.
 *   All rights reserved.
 *
 *   Redistribution and use in source and binary forms, with or without
 *   modification, are permitted provided that the following conditions
 *   are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *     * Neither the name of Intel Corporation nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "spdk/stdinc.h"

#include "nvmf_internal.h"
#include "session.h"
#include "subsystem.h"
#include "transport.h"

#include "spdk/string.h"
#include "spdk/trace.h"
#include "spdk/nvmf_spec.h"

#include "spdk_internal/bdev.h"
#include "spdk_internal/log.h"

bool
spdk_nvmf_subsystem_exists(const char *subnqn)
{
	struct spdk_nvmf_subsystem	*subsystem;

	if (!subnqn) {
		return false;
	}

	TAILQ_FOREACH(subsystem, &g_nvmf_tgt.subsystems, entries) {
		if (strcmp(subnqn, subsystem->subnqn) == 0) {
			return true;
		}
	}

	return false;
}

struct spdk_nvmf_subsystem *
nvmf_find_subsystem(const char *subnqn)
{
	struct spdk_nvmf_subsystem	*subsystem;

	if (!subnqn) {
		return NULL;
	}

	TAILQ_FOREACH(subsystem, &g_nvmf_tgt.subsystems, entries) {
		if (strcmp(subnqn, subsystem->subnqn) == 0) {
			return subsystem;
		}
	}

	return NULL;
}

struct spdk_nvmf_subsystem *
spdk_nvmf_find_subsystem_with_cntlid(uint16_t cntlid)
{
	struct spdk_nvmf_subsystem	*subsystem;
	struct spdk_nvmf_session 	*session;

	TAILQ_FOREACH(subsystem, &g_nvmf_tgt.subsystems, entries) {
		TAILQ_FOREACH(session, &subsystem->sessions, link) {
			if (session->cntlid == cntlid) {
				return subsystem;
			}
		}
	}

	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 (subsystem->num_hosts == 0) {
		/* 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)
{
	return subsystem->ops->attach(subsystem);
}

static bool
nvmf_subsystem_removable(struct spdk_nvmf_subsystem *subsystem)
{
	struct spdk_nvmf_session *session;
	struct spdk_nvmf_conn	*conn;

	if (subsystem->is_removed) {
		TAILQ_FOREACH(session, &subsystem->sessions, link) {
			TAILQ_FOREACH(conn, &session->connections, link) {
				if (!conn->transport->conn_is_idle(conn)) {
					return false;
				}
			}
		}
		return true;
	}
	return false;
}

void
spdk_nvmf_subsystem_poll(struct spdk_nvmf_subsystem *subsystem)
{
	struct spdk_nvmf_session *session;

	/* Check the backing physical device for completions. */
	if (subsystem->ops->poll_for_completions) {
		subsystem->ops->poll_for_completions(subsystem);
	}

	TAILQ_FOREACH(session, &subsystem->sessions, link) {
		/* For each connection in the session, check for completions */
		spdk_nvmf_session_poll(session);
	}

	if (nvmf_subsystem_removable(subsystem)) {
		if (subsystem->ops->detach) {
			subsystem->ops->detach(subsystem);
		}
	}
}

static bool
spdk_nvmf_valid_nqn(const char *nqn)
{
	size_t len;

	len = strlen(nqn);
	if (len > SPDK_NVMF_NQN_MAX_LEN) {
		SPDK_ERRLOG("Invalid NQN \"%s\": length %zu > max %d\n", nqn, len, SPDK_NVMF_NQN_MAX_LEN);
		return false;
	}

	if (strncmp(nqn, "nqn.", 4) != 0) {
		SPDK_ERRLOG("Invalid NQN \"%s\": NQN must begin with \"nqn.\".\n", nqn);
		return false;
	}

	/* yyyy-mm. */
	if (!(isdigit(nqn[4]) && isdigit(nqn[5]) && isdigit(nqn[6]) && isdigit(nqn[7]) &&
	      nqn[8] == '-' && isdigit(nqn[9]) && isdigit(nqn[10]) && nqn[11] == '.')) {
		SPDK_ERRLOG("Invalid date code in NQN \"%s\"\n", nqn);
		return false;
	}

	return true;
}

struct spdk_nvmf_subsystem *
spdk_nvmf_create_subsystem(const char *nqn,
			   enum spdk_nvmf_subtype type,
			   enum spdk_nvmf_subsystem_mode mode,
			   void *cb_ctx,
			   spdk_nvmf_subsystem_connect_fn connect_cb,
			   spdk_nvmf_subsystem_disconnect_fn disconnect_cb)
{
	struct spdk_nvmf_subsystem	*subsystem;

	if (!spdk_nvmf_valid_nqn(nqn)) {
		return NULL;
	}

	subsystem = calloc(1, sizeof(struct spdk_nvmf_subsystem));
	if (subsystem == NULL) {
		return NULL;
	}

	g_nvmf_tgt.current_subsystem_id++;

	subsystem->id = g_nvmf_tgt.current_subsystem_id;
	subsystem->subtype = type;
	subsystem->mode = mode;
	subsystem->cb_ctx = cb_ctx;
	subsystem->connect_cb = connect_cb;
	subsystem->disconnect_cb = disconnect_cb;
	snprintf(subsystem->subnqn, sizeof(subsystem->subnqn), "%s", nqn);
	TAILQ_INIT(&subsystem->allowed_listeners);
	TAILQ_INIT(&subsystem->hosts);
	TAILQ_INIT(&subsystem->sessions);

	if (type == SPDK_NVMF_SUBTYPE_DISCOVERY) {
		subsystem->ops = &spdk_nvmf_discovery_ctrlr_ops;
	} else if (mode == NVMF_SUBSYSTEM_MODE_DIRECT) {
		subsystem->ops = &spdk_nvmf_direct_ctrlr_ops;
		subsystem->dev.direct.outstanding_admin_cmd_count = 0;
	} else {
		subsystem->ops = &spdk_nvmf_virtual_ctrlr_ops;
	}

	TAILQ_INSERT_TAIL(&g_nvmf_tgt.subsystems, subsystem, entries);
	g_nvmf_tgt.discovery_genctr++;

	return subsystem;
}

void
spdk_nvmf_delete_subsystem(struct spdk_nvmf_subsystem *subsystem)
{
	struct spdk_nvmf_subsystem_allowed_listener	*allowed_listener, *allowed_listener_tmp;
	struct spdk_nvmf_host		*host, *host_tmp;
	struct spdk_nvmf_session	*session, *session_tmp;

	if (!subsystem) {
		return;
	}

	SPDK_TRACELOG(SPDK_TRACE_NVMF, "subsystem is %p\n", subsystem);

	TAILQ_FOREACH_SAFE(allowed_listener,
			   &subsystem->allowed_listeners, link, allowed_listener_tmp) {
		TAILQ_REMOVE(&subsystem->allowed_listeners, allowed_listener, link);

		free(allowed_listener);
	}

	TAILQ_FOREACH_SAFE(host, &subsystem->hosts, link, host_tmp) {
		TAILQ_REMOVE(&subsystem->hosts, host, link);
		free(host->nqn);
		free(host);
		subsystem->num_hosts--;
	}

	TAILQ_FOREACH_SAFE(session, &subsystem->sessions, link, session_tmp) {
		spdk_nvmf_session_destruct(session);
	}

	if (subsystem->ops->detach) {
		subsystem->ops->detach(subsystem);
	}

	TAILQ_REMOVE(&g_nvmf_tgt.subsystems, subsystem, entries);
	g_nvmf_tgt.discovery_genctr++;

	free(subsystem);
}

struct spdk_nvmf_listen_addr *
spdk_nvmf_tgt_listen(const char *trname, const char *traddr, const char *trsvcid)
{
	struct spdk_nvmf_listen_addr *listen_addr;
	const struct spdk_nvmf_transport *transport;
	int rc;

	TAILQ_FOREACH(listen_addr, &g_nvmf_tgt.listen_addrs, link) {
		if ((strcmp(listen_addr->trname, trname) == 0) &&
		    (strcmp(listen_addr->traddr, traddr) == 0) &&
		    (strcmp(listen_addr->trsvcid, trsvcid) == 0)) {
			return listen_addr;
		}
	}

	transport = spdk_nvmf_transport_get(trname);
	if (!transport) {
		SPDK_ERRLOG("Unknown transport '%s'\n", trname);
		return NULL;
	}

	listen_addr = spdk_nvmf_listen_addr_create(trname, traddr, trsvcid);
	if (!listen_addr) {
		return NULL;
	}

	rc = transport->listen_addr_add(listen_addr);
	if (rc < 0) {
		spdk_nvmf_listen_addr_cleanup(listen_addr);
		SPDK_ERRLOG("Unable to listen on address '%s'\n", traddr);
		return NULL;
	}

	TAILQ_INSERT_HEAD(&g_nvmf_tgt.listen_addrs, listen_addr, link);
	g_nvmf_tgt.discovery_genctr++;

	return listen_addr;
}

int
spdk_nvmf_subsystem_add_listener(struct spdk_nvmf_subsystem *subsystem,
				 struct spdk_nvmf_listen_addr *listen_addr)
{
	struct spdk_nvmf_subsystem_allowed_listener *allowed_listener;

	allowed_listener = calloc(1, sizeof(*allowed_listener));
	if (!allowed_listener) {
		return -1;
	}

	allowed_listener->listen_addr = listen_addr;

	TAILQ_INSERT_HEAD(&subsystem->allowed_listeners, allowed_listener, link);

	return 0;
}

/*
 * TODO: this is the whitelist and will be called during connection setup
 */
bool
spdk_nvmf_subsystem_listener_allowed(struct spdk_nvmf_subsystem *subsystem,
				     struct spdk_nvmf_listen_addr *listen_addr)
{
	struct spdk_nvmf_subsystem_allowed_listener *allowed_listener;

	if (TAILQ_EMPTY(&subsystem->allowed_listeners)) {
		return true;
	}

	TAILQ_FOREACH(allowed_listener, &subsystem->allowed_listeners, link) {
		if (allowed_listener->listen_addr == listen_addr) {
			return true;
		}
	}

	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);
	subsystem->num_hosts++;
	g_nvmf_tgt.discovery_genctr++;

	return 0;
}

int
nvmf_subsystem_add_ctrlr(struct spdk_nvmf_subsystem *subsystem,
			 struct spdk_nvme_ctrlr *ctrlr, const struct spdk_pci_addr *pci_addr)
{
	subsystem->dev.direct.ctrlr = ctrlr;
	subsystem->dev.direct.pci_addr = *pci_addr;

	return 0;
}

static void spdk_nvmf_ctrlr_hot_remove(void *remove_ctx)
{
	struct spdk_nvmf_subsystem *subsystem = (struct spdk_nvmf_subsystem *)remove_ctx;

	subsystem->is_removed = true;
}

int
spdk_nvmf_subsystem_add_ns(struct spdk_nvmf_subsystem *subsystem, struct spdk_bdev *bdev)
{
	int i = 0;

	assert(subsystem->mode == NVMF_SUBSYSTEM_MODE_VIRTUAL);
	while (i < MAX_VIRTUAL_NAMESPACE && subsystem->dev.virt.ns_list[i]) {
		i++;
	}
	if (i == MAX_VIRTUAL_NAMESPACE) {
		SPDK_ERRLOG("spdk_nvmf_subsystem_add_ns() failed\n");
		return -1;
	}

	if (!spdk_bdev_claim(bdev, spdk_nvmf_ctrlr_hot_remove, subsystem)) {
		SPDK_ERRLOG("Subsystem %s: bdev %s is already claimed\n",
			    subsystem->subnqn, spdk_bdev_get_name(bdev));
		return -1;
	}

	subsystem->dev.virt.ns_list[i] = bdev;
	subsystem->dev.virt.ns_count++;
	return 0;
}

int
spdk_nvmf_subsystem_set_sn(struct spdk_nvmf_subsystem *subsystem, const char *sn)
{
	if (subsystem->mode != NVMF_SUBSYSTEM_MODE_VIRTUAL) {
		return -1;
	}

	snprintf(subsystem->dev.virt.sn, sizeof(subsystem->dev.virt.sn), "%s", sn);

	return 0;
}

const char *
spdk_nvmf_subsystem_get_nqn(struct spdk_nvmf_subsystem *subsystem)
{
	return subsystem->subnqn;
}

/* Workaround for astyle formatting bug */
typedef enum spdk_nvmf_subtype nvmf_subtype_t;

nvmf_subtype_t
spdk_nvmf_subsystem_get_type(struct spdk_nvmf_subsystem *subsystem)
{
	return subsystem->subtype;
}

/* Workaround for astyle formatting bug */
typedef enum spdk_nvmf_subsystem_mode nvmf_mode_t;

nvmf_mode_t
spdk_nvmf_subsystem_get_mode(struct spdk_nvmf_subsystem *subsystem)
{
	return subsystem->mode;
}