1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright(c) 2009 Intel Corporation. All rights reserved.
4 *
5 * Maintained at www.Open-FCoE.org
6 */
7
8#include <linux/kernel.h>
9#include <linux/types.h>
10#include <linux/scatterlist.h>
11#include <linux/crc32.h>
12#include <linux/module.h>
13
14#include <scsi/libfc.h>
15
16#include "fc_encode.h"
17#include "fc_libfc.h"
18
19MODULE_AUTHOR("Open-FCoE.org");
20MODULE_DESCRIPTION("libfc");
21MODULE_LICENSE("GPL v2");
22
23unsigned int fc_debug_logging;
24module_param_named(debug_logging, fc_debug_logging, int, S_IRUGO|S_IWUSR);
25MODULE_PARM_DESC(debug_logging, "a bit mask of logging levels");
26
27DEFINE_MUTEX(fc_prov_mutex);
28static LIST_HEAD(fc_local_ports);
29struct blocking_notifier_head fc_lport_notifier_head =
30		BLOCKING_NOTIFIER_INIT(fc_lport_notifier_head);
31EXPORT_SYMBOL(fc_lport_notifier_head);
32
33/*
34 * Providers which primarily send requests and PRLIs.
35 */
36struct fc4_prov *fc_active_prov[FC_FC4_PROV_SIZE] = {
37	[0] = &fc_rport_t0_prov,
38	[FC_TYPE_FCP] = &fc_rport_fcp_init,
39};
40
41/*
42 * Providers which receive requests.
43 */
44struct fc4_prov *fc_passive_prov[FC_FC4_PROV_SIZE] = {
45	[FC_TYPE_ELS] = &fc_lport_els_prov,
46};
47
48/**
49 * libfc_init() - Initialize libfc.ko
50 */
51static int __init libfc_init(void)
52{
53	int rc = 0;
54
55	rc = fc_setup_fcp();
56	if (rc)
57		return rc;
58
59	rc = fc_setup_exch_mgr();
60	if (rc)
61		goto destroy_pkt_cache;
62
63	rc = fc_setup_rport();
64	if (rc)
65		goto destroy_em;
66
67	return rc;
68destroy_em:
69	fc_destroy_exch_mgr();
70destroy_pkt_cache:
71	fc_destroy_fcp();
72	return rc;
73}
74module_init(libfc_init);
75
76/**
77 * libfc_exit() - Tear down libfc.ko
78 */
79static void __exit libfc_exit(void)
80{
81	fc_destroy_fcp();
82	fc_destroy_exch_mgr();
83	fc_destroy_rport();
84}
85module_exit(libfc_exit);
86
87/**
88 * fc_copy_buffer_to_sglist() - This routine copies the data of a buffer
89 *				into a scatter-gather list (SG list).
90 *
91 * @buf: pointer to the data buffer.
92 * @len: the byte-length of the data buffer.
93 * @sg: pointer to the pointer of the SG list.
94 * @nents: pointer to the remaining number of entries in the SG list.
95 * @offset: pointer to the current offset in the SG list.
96 * @crc: pointer to the 32-bit crc value.
97 *	 If crc is NULL, CRC is not calculated.
98 */
99u32 fc_copy_buffer_to_sglist(void *buf, size_t len,
100			     struct scatterlist *sg,
101			     u32 *nents, size_t *offset,
102			     u32 *crc)
103{
104	size_t remaining = len;
105	u32 copy_len = 0;
106
107	while (remaining > 0 && sg) {
108		size_t off, sg_bytes;
109		void *page_addr;
110
111		if (*offset >= sg->length) {
112			/*
113			 * Check for end and drop resources
114			 * from the last iteration.
115			 */
116			if (!(*nents))
117				break;
118			--(*nents);
119			*offset -= sg->length;
120			sg = sg_next(sg);
121			continue;
122		}
123		sg_bytes = min(remaining, sg->length - *offset);
124
125		/*
126		 * The scatterlist item may be bigger than PAGE_SIZE,
127		 * but we are limited to mapping PAGE_SIZE at a time.
128		 */
129		off = *offset + sg->offset;
130		sg_bytes = min(sg_bytes,
131			       (size_t)(PAGE_SIZE - (off & ~PAGE_MASK)));
132		page_addr = kmap_atomic(sg_page(sg) + (off >> PAGE_SHIFT));
133		if (crc)
134			*crc = crc32(*crc, buf, sg_bytes);
135		memcpy((char *)page_addr + (off & ~PAGE_MASK), buf, sg_bytes);
136		kunmap_atomic(page_addr);
137		buf += sg_bytes;
138		*offset += sg_bytes;
139		remaining -= sg_bytes;
140		copy_len += sg_bytes;
141	}
142	return copy_len;
143}
144
145/**
146 * fc_fill_hdr() -  fill FC header fields based on request
147 * @fp: reply frame containing header to be filled in
148 * @in_fp: request frame containing header to use in filling in reply
149 * @r_ctl: R_CTL value for header
150 * @f_ctl: F_CTL value for header, with 0 pad
151 * @seq_cnt: sequence count for the header, ignored if frame has a sequence
152 * @parm_offset: parameter / offset value
153 */
154void fc_fill_hdr(struct fc_frame *fp, const struct fc_frame *in_fp,
155		 enum fc_rctl r_ctl, u32 f_ctl, u16 seq_cnt, u32 parm_offset)
156{
157	struct fc_frame_header *fh;
158	struct fc_frame_header *in_fh;
159	struct fc_seq *sp;
160	u32 fill;
161
162	fh = __fc_frame_header_get(fp);
163	in_fh = __fc_frame_header_get(in_fp);
164
165	if (f_ctl & FC_FC_END_SEQ) {
166		fill = -fr_len(fp) & 3;
167		if (fill) {
168			/* TODO, this may be a problem with fragmented skb */
169			skb_put_zero(fp_skb(fp), fill);
170			f_ctl |= fill;
171		}
172		fr_eof(fp) = FC_EOF_T;
173	} else {
174		WARN_ON(fr_len(fp) % 4 != 0);	/* no pad to non last frame */
175		fr_eof(fp) = FC_EOF_N;
176	}
177
178	fh->fh_r_ctl = r_ctl;
179	memcpy(fh->fh_d_id, in_fh->fh_s_id, sizeof(fh->fh_d_id));
180	memcpy(fh->fh_s_id, in_fh->fh_d_id, sizeof(fh->fh_s_id));
181	fh->fh_type = in_fh->fh_type;
182	hton24(fh->fh_f_ctl, f_ctl);
183	fh->fh_ox_id = in_fh->fh_ox_id;
184	fh->fh_rx_id = in_fh->fh_rx_id;
185	fh->fh_cs_ctl = 0;
186	fh->fh_df_ctl = 0;
187	fh->fh_parm_offset = htonl(parm_offset);
188
189	sp = fr_seq(in_fp);
190	if (sp) {
191		fr_seq(fp) = sp;
192		fh->fh_seq_id = sp->id;
193		seq_cnt = sp->cnt;
194	} else {
195		fh->fh_seq_id = 0;
196	}
197	fh->fh_seq_cnt = ntohs(seq_cnt);
198	fr_sof(fp) = seq_cnt ? FC_SOF_N3 : FC_SOF_I3;
199	fr_encaps(fp) = fr_encaps(in_fp);
200}
201EXPORT_SYMBOL(fc_fill_hdr);
202
203/**
204 * fc_fill_reply_hdr() -  fill FC reply header fields based on request
205 * @fp: reply frame containing header to be filled in
206 * @in_fp: request frame containing header to use in filling in reply
207 * @r_ctl: R_CTL value for reply
208 * @parm_offset: parameter / offset value
209 */
210void fc_fill_reply_hdr(struct fc_frame *fp, const struct fc_frame *in_fp,
211		       enum fc_rctl r_ctl, u32 parm_offset)
212{
213	struct fc_seq *sp;
214
215	sp = fr_seq(in_fp);
216	if (sp)
217		fr_seq(fp) = fc_seq_start_next(sp);
218	fc_fill_hdr(fp, in_fp, r_ctl, FC_FCTL_RESP, 0, parm_offset);
219}
220EXPORT_SYMBOL(fc_fill_reply_hdr);
221
222/**
223 * fc_fc4_conf_lport_params() - Modify "service_params" of specified lport
224 * if there is service provider (target provider) registered with libfc
225 * for specified "fc_ft_type"
226 * @lport: Local port which service_params needs to be modified
227 * @type: FC-4 type, such as FC_TYPE_FCP
228 */
229void fc_fc4_conf_lport_params(struct fc_lport *lport, enum fc_fh_type type)
230{
231	struct fc4_prov *prov_entry;
232	BUG_ON(type >= FC_FC4_PROV_SIZE);
233	BUG_ON(!lport);
234	prov_entry = fc_passive_prov[type];
235	if (type == FC_TYPE_FCP) {
236		if (prov_entry && prov_entry->recv)
237			lport->service_params |= FCP_SPPF_TARG_FCN;
238	}
239}
240
241void fc_lport_iterate(void (*notify)(struct fc_lport *, void *), void *arg)
242{
243	struct fc_lport *lport;
244
245	mutex_lock(&fc_prov_mutex);
246	list_for_each_entry(lport, &fc_local_ports, lport_list)
247		notify(lport, arg);
248	mutex_unlock(&fc_prov_mutex);
249}
250EXPORT_SYMBOL(fc_lport_iterate);
251
252/**
253 * fc_fc4_register_provider() - register FC-4 upper-level provider.
254 * @type: FC-4 type, such as FC_TYPE_FCP
255 * @prov: structure describing provider including ops vector.
256 *
257 * Returns 0 on success, negative error otherwise.
258 */
259int fc_fc4_register_provider(enum fc_fh_type type, struct fc4_prov *prov)
260{
261	struct fc4_prov **prov_entry;
262	int ret = 0;
263
264	if (type >= FC_FC4_PROV_SIZE)
265		return -EINVAL;
266	mutex_lock(&fc_prov_mutex);
267	prov_entry = (prov->recv ? fc_passive_prov : fc_active_prov) + type;
268	if (*prov_entry)
269		ret = -EBUSY;
270	else
271		*prov_entry = prov;
272	mutex_unlock(&fc_prov_mutex);
273	return ret;
274}
275EXPORT_SYMBOL(fc_fc4_register_provider);
276
277/**
278 * fc_fc4_deregister_provider() - deregister FC-4 upper-level provider.
279 * @type: FC-4 type, such as FC_TYPE_FCP
280 * @prov: structure describing provider including ops vector.
281 */
282void fc_fc4_deregister_provider(enum fc_fh_type type, struct fc4_prov *prov)
283{
284	BUG_ON(type >= FC_FC4_PROV_SIZE);
285	mutex_lock(&fc_prov_mutex);
286	if (prov->recv)
287		RCU_INIT_POINTER(fc_passive_prov[type], NULL);
288	else
289		RCU_INIT_POINTER(fc_active_prov[type], NULL);
290	mutex_unlock(&fc_prov_mutex);
291	synchronize_rcu();
292}
293EXPORT_SYMBOL(fc_fc4_deregister_provider);
294
295/**
296 * fc_fc4_add_lport() - add new local port to list and run notifiers.
297 * @lport:  The new local port.
298 */
299void fc_fc4_add_lport(struct fc_lport *lport)
300{
301	mutex_lock(&fc_prov_mutex);
302	list_add_tail(&lport->lport_list, &fc_local_ports);
303	blocking_notifier_call_chain(&fc_lport_notifier_head,
304				     FC_LPORT_EV_ADD, lport);
305	mutex_unlock(&fc_prov_mutex);
306}
307
308/**
309 * fc_fc4_del_lport() - remove local port from list and run notifiers.
310 * @lport:  The new local port.
311 */
312void fc_fc4_del_lport(struct fc_lport *lport)
313{
314	mutex_lock(&fc_prov_mutex);
315	list_del(&lport->lport_list);
316	blocking_notifier_call_chain(&fc_lport_notifier_head,
317				     FC_LPORT_EV_DEL, lport);
318	mutex_unlock(&fc_prov_mutex);
319}
320