drivers/scsi/libfc/fc_elsct.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright(c) 2008 Intel Corporation. All rights reserved.
   4  *
   5  * Maintained at www.Open-FCoE.org
   6  */
   7
   8 /*
   9  * Provide interface to send ELS/CT FC frames
  10  */
  11
  12 #include <linux/export.h>
  13 #include <asm/unaligned.h>
  14 #include <scsi/fc/fc_gs.h>
  15 #include <scsi/fc/fc_ns.h>
  16 #include <scsi/fc/fc_els.h>
  17 #include <scsi/libfc.h>
  18 #include <scsi/fc_encode.h>
  19 #include "fc_libfc.h"
  20
  21 /**
  22  * fc_elsct_send() - Send an ELS or CT frame
  23  * @lport:      The local port to send the frame on
  24  * @did:        The destination ID for the frame
  25  * @fp:         The frame to be sent
  26  * @op:         The operational code
  27  * @resp:       The callback routine when the response is received
  28  * @arg:        The argument to pass to the response callback routine
  29  * @timer_msec: The timeout period for the frame (in msecs)
  30  */
  31 struct fc_seq *fc_elsct_send(struct fc_lport *lport, u32 did,
  32                              struct fc_frame *fp, unsigned int op,
  33                              void (*resp)(struct fc_seq *,
  34                                           struct fc_frame *,
  35                                           void *),
  36                              void *arg, u32 timer_msec)
  37 {
  38         enum fc_rctl r_ctl;
  39         enum fc_fh_type fh_type;
  40         int rc;
  41
  42         /* ELS requests */
  43         if ((op >= ELS_LS_RJT) && (op <= ELS_AUTH_ELS))
  44                 rc = fc_els_fill(lport, did, fp, op, &r_ctl, &fh_type);
  45         else {
  46                 /* CT requests */
  47                 rc = fc_ct_fill(lport, did, fp, op, &r_ctl, &fh_type, &did);
  48         }
  49
  50         if (rc) {
  51                 fc_frame_free(fp);
  52                 return NULL;
  53         }
  54
  55         fc_fill_fc_hdr(fp, r_ctl, did, lport->port_id, fh_type,
  56                        FC_FCTL_REQ, 0);
  57
  58         return fc_exch_seq_send(lport, fp, resp, NULL, arg, timer_msec);
  59 }
  60 EXPORT_SYMBOL(fc_elsct_send);
  61
  62 /**
  63  * fc_elsct_init() - Initialize the ELS/CT layer
  64  * @lport: The local port to initialize the ELS/CT layer for
  65  */
  66 int fc_elsct_init(struct fc_lport *lport)
  67 {
  68         if (!lport->tt.elsct_send)
  69                 lport->tt.elsct_send = fc_elsct_send;
  70
  71         return 0;
  72 }
  73 EXPORT_SYMBOL(fc_elsct_init);
  74
  75 /**
  76  * fc_els_resp_type() - Return a string describing the ELS response
  77  * @fp: The frame pointer or possible error code
  78  */
  79 const char *fc_els_resp_type(struct fc_frame *fp)
  80 {
  81         const char *msg;
  82         struct fc_frame_header *fh;
  83         struct fc_ct_hdr *ct;
  84
  85         if (IS_ERR(fp)) {
  86                 switch (-PTR_ERR(fp)) {
  87                 case FC_NO_ERR:
  88                         msg = "response no error";
  89                         break;
  90                 case FC_EX_TIMEOUT:
  91                         msg = "response timeout";
  92                         break;
  93                 case FC_EX_CLOSED:
  94                         msg = "response closed";
  95                         break;
  96                 default:
  97                         msg = "response unknown error";
  98                         break;
  99                 }
 100         } else {
 101                 fh = fc_frame_header_get(fp);
 102                 switch (fh->fh_type) {
 103                 case FC_TYPE_ELS:
 104                         switch (fc_frame_payload_op(fp)) {
 105                         case ELS_LS_ACC:
 106                                 msg = "accept";
 107                                 break;
 108                         case ELS_LS_RJT:
 109                                 msg = "reject";
 110                                 break;
 111                         default:
 112                                 msg = "response unknown ELS";
 113                                 break;
 114                         }
 115                         break;
 116                 case FC_TYPE_CT:
 117                         ct = fc_frame_payload_get(fp, sizeof(*ct));
 118                         if (ct) {
 119                                 switch (ntohs(ct->ct_cmd)) {
 120                                 case FC_FS_ACC:
 121                                         msg = "CT accept";
 122                                         break;
 123                                 case FC_FS_RJT:
 124                                         msg = "CT reject";
 125                                         break;
 126                                 default:
 127                                         msg = "response unknown CT";
 128                                         break;
 129                                 }
 130                         } else {
 131                                 msg = "short CT response";
 132                         }
 133                         break;
 134                 default:
 135                         msg = "response not ELS or CT";
 136                         break;
 137                 }
 138         }
 139         return msg;
 140 }