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 <asm/unaligned.h>
  25 #include <scsi/fc/fc_gs.h>
  26 #include <scsi/fc/fc_ns.h>
  27 #include <scsi/fc/fc_els.h>
  28 #include <scsi/libfc.h>
  29 #include <scsi/fc_encode.h>
  30
  31 /**
  32  * fc_elsct_send() - Send an ELS or CT frame
  33  * @lport:      The local port to send the frame on
  34  * @did:        The destination ID for the frame
  35  * @fp:         The frame to be sent
  36  * @op:         The operational code
  37  * @resp:       The callback routine when the response is received
  38  * @arg:        The argument to pass to the response callback routine
  39  * @timer_msec: The timeout period for the frame (in msecs)
  40  */
  41 struct fc_seq *fc_elsct_send(struct fc_lport *lport, u32 did,
  42                              struct fc_frame *fp, unsigned int op,
  43                              void (*resp)(struct fc_seq *,
  44                                           struct fc_frame *,
  45                                           void *),
  46                              void *arg, u32 timer_msec)
  47 {
  48         enum fc_rctl r_ctl;
  49         enum fc_fh_type fh_type;
  50         int rc;
  51
  52         /* ELS requests */
  53         if ((op >= ELS_LS_RJT) && (op <= ELS_AUTH_ELS))
  54                 rc = fc_els_fill(lport, did, fp, op, &r_ctl, &fh_type);
  55         else {
  56                 /* CT requests */
  57                 rc = fc_ct_fill(lport, did, fp, op, &r_ctl, &fh_type);
  58                 did = FC_FID_DIR_SERV;
  59         }
  60
  61         if (rc) {
  62                 fc_frame_free(fp);
  63                 return NULL;
  64         }
  65
  66         fc_fill_fc_hdr(fp, r_ctl, did, lport->port_id, fh_type,
  67                        FC_FCTL_REQ, 0);
  68
  69         return lport->tt.exch_seq_send(lport, fp, resp, NULL, arg, timer_msec);
  70 }
  71 EXPORT_SYMBOL(fc_elsct_send);
  72
  73 /**
  74  * fc_elsct_init() - Initialize the ELS/CT layer
  75  * @lport: The local port to initialize the ELS/CT layer for
  76  */
  77 int fc_elsct_init(struct fc_lport *lport)
  78 {
  79         if (!lport->tt.elsct_send)
  80                 lport->tt.elsct_send = fc_elsct_send;
  81
  82         return 0;
  83 }
  84 EXPORT_SYMBOL(fc_elsct_init);
  85
  86 /**
  87  * fc_els_resp_type() - Return a string describing the ELS response
  88  * @fp: The frame pointer or possible error code
  89  */
  90 const char *fc_els_resp_type(struct fc_frame *fp)
  91 {
  92         const char *msg;
  93         struct fc_frame_header *fh;
  94         struct fc_ct_hdr *ct;
  95
  96         if (IS_ERR(fp)) {
  97                 switch (-PTR_ERR(fp)) {
  98                 case FC_NO_ERR:
  99                         msg = "response no error";
 100                         break;
 101                 case FC_EX_TIMEOUT:
 102                         msg = "response timeout";
 103                         break;
 104                 case FC_EX_CLOSED:
 105                         msg = "response closed";
 106                         break;
 107                 default:
 108                         msg = "response unknown error";
 109                         break;
 110                 }
 111         } else {
 112                 fh = fc_frame_header_get(fp);
 113                 switch (fh->fh_type) {
 114                 case FC_TYPE_ELS:
 115                         switch (fc_frame_payload_op(fp)) {
 116                         case ELS_LS_ACC:
 117                                 msg = "accept";
 118                                 break;
 119                         case ELS_LS_RJT:
 120                                 msg = "reject";
 121                                 break;
 122                         default:
 123                                 msg = "response unknown ELS";
 124                                 break;
 125                         }
 126                         break;
 127                 case FC_TYPE_CT:
 128                         ct = fc_frame_payload_get(fp, sizeof(*ct));
 129                         if (ct) {
 130                                 switch (ntohs(ct->ct_cmd)) {
 131                                 case FC_FS_ACC:
 132                                         msg = "CT accept";
 133                                         break;
 134                                 case FC_FS_RJT:
 135                                         msg = "CT reject";
 136                                         break;
 137                                 default:
 138                                         msg = "response unknown CT";
 139                                         break;
 140                                 }
 141                         } else {
 142                                 msg = "short CT response";
 143                         }
 144                         break;
 145                 default:
 146                         msg = "response not ELS or CT";
 147                         break;
 148                 }
 149         }
 150         return msg;
 151 }