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);
  60                 did = FC_FID_DIR_SERV;
  61         }
  62
  63         if (rc) {
  64                 fc_frame_free(fp);
  65                 return NULL;
  66         }
  67
  68         fc_fill_fc_hdr(fp, r_ctl, did, lport->port_id, fh_type,
  69                        FC_FCTL_REQ, 0);
  70
  71         return lport->tt.exch_seq_send(lport, fp, resp, NULL, arg, timer_msec);
  72 }
  73 EXPORT_SYMBOL(fc_elsct_send);
  74
  75 /**
  76  * fc_elsct_init() - Initialize the ELS/CT layer
  77  * @lport: The local port to initialize the ELS/CT layer for
  78  */
  79 int fc_elsct_init(struct fc_lport *lport)
  80 {
  81         if (!lport->tt.elsct_send)
  82                 lport->tt.elsct_send = fc_elsct_send;
  83
  84         return 0;
  85 }
  86 EXPORT_SYMBOL(fc_elsct_init);
  87
  88 /**
  89  * fc_els_resp_type() - Return a string describing the ELS response
  90  * @fp: The frame pointer or possible error code
  91  */
  92 const char *fc_els_resp_type(struct fc_frame *fp)
  93 {
  94         const char *msg;
  95         struct fc_frame_header *fh;
  96         struct fc_ct_hdr *ct;
  97
  98         if (IS_ERR(fp)) {
  99                 switch (-PTR_ERR(fp)) {
 100                 case FC_NO_ERR:
 101                         msg = "response no error";
 102                         break;
 103                 case FC_EX_TIMEOUT:
 104                         msg = "response timeout";
 105                         break;
 106                 case FC_EX_CLOSED:
 107                         msg = "response closed";
 108                         break;
 109                 default:
 110                         msg = "response unknown error";
 111                         break;
 112                 }
 113         } else {
 114                 fh = fc_frame_header_get(fp);
 115                 switch (fh->fh_type) {
 116                 case FC_TYPE_ELS:
 117                         switch (fc_frame_payload_op(fp)) {
 118                         case ELS_LS_ACC:
 119                                 msg = "accept";
 120                                 break;
 121                         case ELS_LS_RJT:
 122                                 msg = "reject";
 123                                 break;
 124                         default:
 125                                 msg = "response unknown ELS";
 126                                 break;
 127                         }
 128                         break;
 129                 case FC_TYPE_CT:
 130                         ct = fc_frame_payload_get(fp, sizeof(*ct));
 131                         if (ct) {
 132                                 switch (ntohs(ct->ct_cmd)) {
 133                                 case FC_FS_ACC:
 134                                         msg = "CT accept";
 135                                         break;
 136                                 case FC_FS_RJT:
 137                                         msg = "CT reject";
 138                                         break;
 139                                 default:
 140                                         msg = "response unknown CT";
 141                                         break;
 142                                 }
 143                         } else {
 144                                 msg = "short CT response";
 145                         }
 146                         break;
 147                 default:
 148                         msg = "response not ELS or CT";
 149                         break;
 150                 }
 151         }
 152         return msg;
 153 }