xref: /linux/drivers/scsi/libfc/fc_elsct.c (revision b43ab901d671e3e3cad425ea5e9a3c74e266dcdd)
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 }
154