// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright(c) 2008 Intel Corporation. All rights reserved.
 *
 * Maintained at www.Open-FCoE.org
 */

/*
 * Provide interface to send ELS/CT FC frames
 */

#include <linux/export.h>
#include <linux/unaligned.h>
#include <scsi/fc/fc_gs.h>
#include <scsi/fc/fc_ns.h>
#include <scsi/fc/fc_els.h>
#include <scsi/libfc.h>
#include "fc_encode.h"
#include "fc_libfc.h"

/**
 * fc_elsct_send() - Send an ELS or CT frame
 * @lport:      The local port to send the frame on
 * @did:        The destination ID for the frame
 * @fp:         The frame to be sent
 * @op:         The operational code
 * @resp:       The callback routine when the response is received
 * @arg:        The argument to pass to the response callback routine
 * @timer_msec: The timeout period for the frame (in msecs)
 */
struct fc_seq *fc_elsct_send(struct fc_lport *lport, u32 did,
                             struct fc_frame *fp, unsigned int op,
                             void (*resp)(struct fc_seq *,
                                          struct fc_frame *,
                                          void *),
                             void *arg, u32 timer_msec)
{
        enum fc_rctl r_ctl;
        enum fc_fh_type fh_type;
        int rc;

        /* ELS requests */
        if ((op >= ELS_LS_RJT) && (op <= ELS_AUTH_ELS))
                rc = fc_els_fill(lport, did, fp, op, &r_ctl, &fh_type);
        else {
                /* CT requests */
                rc = fc_ct_fill(lport, did, fp, op, &r_ctl, &fh_type, &did);
        }

        if (rc) {
                fc_frame_free(fp);
                return NULL;
        }

        fc_fill_fc_hdr(fp, r_ctl, did, lport->port_id, fh_type,
                       FC_FCTL_REQ, 0);

        return fc_exch_seq_send(lport, fp, resp, NULL, arg, timer_msec);
}
EXPORT_SYMBOL(fc_elsct_send);

/**
 * fc_elsct_init() - Initialize the ELS/CT layer
 * @lport: The local port to initialize the ELS/CT layer for
 */
int fc_elsct_init(struct fc_lport *lport)
{
        if (!lport->tt.elsct_send)
                lport->tt.elsct_send = fc_elsct_send;

        return 0;
}
EXPORT_SYMBOL(fc_elsct_init);

/**
 * fc_els_resp_type() - Return a string describing the ELS response
 * @fp: The frame pointer or possible error code
 */
const char *fc_els_resp_type(struct fc_frame *fp)
{
        const char *msg;
        struct fc_frame_header *fh;
        struct fc_ct_hdr *ct;

        if (IS_ERR(fp)) {
                switch (-PTR_ERR(fp)) {
                case FC_NO_ERR:
                        msg = "response no error";
                        break;
                case FC_EX_TIMEOUT:
                        msg = "response timeout";
                        break;
                case FC_EX_CLOSED:
                        msg = "response closed";
                        break;
                default:
                        msg = "response unknown error";
                        break;
                }
        } else {
                fh = fc_frame_header_get(fp);
                switch (fh->fh_type) {
                case FC_TYPE_ELS:
                        switch (fc_frame_payload_op(fp)) {
                        case ELS_LS_ACC:
                                msg = "accept";
                                break;
                        case ELS_LS_RJT:
                                msg = "reject";
                                break;
                        default:
                                msg = "response unknown ELS";
                                break;
                        }
                        break;
                case FC_TYPE_CT:
                        ct = fc_frame_payload_get(fp, sizeof(*ct));
                        if (ct) {
                                switch (ntohs(ct->ct_cmd)) {
                                case FC_FS_ACC:
                                        msg = "CT accept";
                                        break;
                                case FC_FS_RJT:
                                        msg = "CT reject";
                                        break;
                                default:
                                        msg = "response unknown CT";
                                        break;
                                }
                        } else {
                                msg = "short CT response";
                        }
                        break;
                default:
                        msg = "response not ELS or CT";
                        break;
                }
        }
        return msg;
}