drivers/scsi/libfc/fc_elsct.c

   1 /*
   2  * Copyright(c) 2008 Intel Corporation. All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  16  *
  17  * Maintained at www.Open-FCoE.org
  18  */
  19
  20 /*
  21  * Provide interface to send ELS/CT FC frames
  22  */
  23
  24 #include <linux/export.h>
  25 #include <asm/unaligned.h>
  26 #include <scsi/fc/fc_gs.h>
  27 #include <scsi/fc/fc_ns.h>
  28 #include <scsi/fc/fc_els.h>
  29 #include <scsi/libfc.h>
  30 #include <scsi/fc_encode.h>
  31 #include "fc_libfc.h"
  32
  33 /**
  34  * fc_elsct_send() - Send an ELS or CT frame
  35  * @lport:      The local port to send the frame on
  36  * @did:        The destination ID for the frame
  37  * @fp:         The frame to be sent
  38  * @op:         The operational code
  39  * @resp:       The callback routine when the response is received
  40  * @arg:        The argument to pass to the response callback routine
  41  * @timer_msec: The timeout period for the frame (in msecs)
  42  */
  43 struct fc_seq *fc_elsct_send(struct fc_lport *lport, u32 did,
  44                              struct fc_frame *fp, unsigned int op,
  45                              void (*resp)(struct fc_seq *,
  46                                           struct fc_frame *,
  47                                           void *),
  48                              void *arg, u32 timer_msec)
  49 {
  50         enum fc_rctl r_ctl;
  51         enum fc_fh_type fh_type;
  52         int rc;
  53
  54         /* ELS requests */
  55         if ((op >= ELS_LS_RJT) && (op <= ELS_AUTH_ELS))
  56                 rc = fc_els_fill(lport, did, fp, op, &r_ctl, &fh_type);
  57         else {
  58                 /* CT requests */
  59                 rc = fc_ct_fill(lport, did, fp, op, &r_ctl, &fh_type, &did);
  60         }
  61
  62         if (rc) {
  63                 fc_frame_free(fp);
  64                 return NULL;
  65         }
  66
  67         fc_fill_fc_hdr(fp, r_ctl, did, lport->port_id, fh_type,
  68                        FC_FCTL_REQ, 0);
  69
  70         return fc_exch_seq_send(lport, fp, resp, NULL, arg, timer_msec);
  71 }
  72 EXPORT_SYMBOL(fc_elsct_send);
  73
  74 /**
  75  * fc_elsct_init() - Initialize the ELS/CT layer
  76  * @lport: The local port to initialize the ELS/CT layer for
  77  */
  78 int fc_elsct_init(struct fc_lport *lport)
  79 {
  80         if (!lport->tt.elsct_send)
  81                 lport->tt.elsct_send = fc_elsct_send;
  82
  83         return 0;
  84 }
  85 EXPORT_SYMBOL(fc_elsct_init);
  86
  87 /**
  88  * fc_els_resp_type() - Return a string describing the ELS response
  89  * @fp: The frame pointer or possible error code
  90  */
  91 const char *fc_els_resp_type(struct fc_frame *fp)
  92 {
  93         const char *msg;
  94         struct fc_frame_header *fh;
  95         struct fc_ct_hdr *ct;
  96
  97         if (IS_ERR(fp)) {
  98                 switch (-PTR_ERR(fp)) {
  99                 case FC_NO_ERR:
 100                         msg = "response no error";
 101                         break;
 102                 case FC_EX_TIMEOUT:
 103                         msg = "response timeout";
 104                         break;
 105                 case FC_EX_CLOSED:
 106                         msg = "response closed";
 107                         break;
 108                 default:
 109                         msg = "response unknown error";
 110                         break;
 111                 }
 112         } else {
 113                 fh = fc_frame_header_get(fp);
 114                 switch (fh->fh_type) {
 115                 case FC_TYPE_ELS:
 116                         switch (fc_frame_payload_op(fp)) {
 117                         case ELS_LS_ACC:
 118                                 msg = "accept";
 119                                 break;
 120                         case ELS_LS_RJT:
 121                                 msg = "reject";
 122                                 break;
 123                         default:
 124                                 msg = "response unknown ELS";
 125                                 break;
 126                         }
 127                         break;
 128                 case FC_TYPE_CT:
 129                         ct = fc_frame_payload_get(fp, sizeof(*ct));
 130                         if (ct) {
 131                                 switch (ntohs(ct->ct_cmd)) {
 132                                 case FC_FS_ACC:
 133                                         msg = "CT accept";
 134                                         break;
 135                                 case FC_FS_RJT:
 136                                         msg = "CT reject";
 137                                         break;
 138                                 default:
 139                                         msg = "response unknown CT";
 140                                         break;
 141                                 }
 142                         } else {
 143                                 msg = "short CT response";
 144                         }
 145                         break;
 146                 default:
 147                         msg = "response not ELS or CT";
 148                         break;
 149                 }
 150         }
 151         return msg;
 152 }