linux/drivers/scsi/libfc/fc_elsct.c

// 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;
}