xref: /openbmc/linux/drivers/scsi/libfc/fc_elsct.c (revision a44e4f3a)
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 }
141