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 
19 MODULE_AUTHOR("Open-FCoE.org");
20 MODULE_DESCRIPTION("libfc");
21 MODULE_LICENSE("GPL v2");
22 
23 unsigned int fc_debug_logging;
24 module_param_named(debug_logging, fc_debug_logging, int, S_IRUGO|S_IWUSR);
25 MODULE_PARM_DESC(debug_logging, "a bit mask of logging levels");
26 
27 DEFINE_MUTEX(fc_prov_mutex);
28 static LIST_HEAD(fc_local_ports);
29 struct blocking_notifier_head fc_lport_notifier_head =
30 		BLOCKING_NOTIFIER_INIT(fc_lport_notifier_head);
31 EXPORT_SYMBOL(fc_lport_notifier_head);
32 
33 /*
34  * Providers which primarily send requests and PRLIs.
35  */
36 struct 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  */
44 struct 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  */
libfc_init(void)51 static 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;
68 destroy_em:
69 	fc_destroy_exch_mgr();
70 destroy_pkt_cache:
71 	fc_destroy_fcp();
72 	return rc;
73 }
74 module_init(libfc_init);
75 
76 /**
77  * libfc_exit() - Tear down libfc.ko
78  */
libfc_exit(void)79 static void __exit libfc_exit(void)
80 {
81 	fc_destroy_fcp();
82 	fc_destroy_exch_mgr();
83 	fc_destroy_rport();
84 }
85 module_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  */
fc_copy_buffer_to_sglist(void * buf,size_t len,struct scatterlist * sg,u32 * nents,size_t * offset,u32 * crc)99 u32 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  */
fc_fill_hdr(struct fc_frame * fp,const struct fc_frame * in_fp,enum fc_rctl r_ctl,u32 f_ctl,u16 seq_cnt,u32 parm_offset)154 void 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 }
201 EXPORT_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  */
fc_fill_reply_hdr(struct fc_frame * fp,const struct fc_frame * in_fp,enum fc_rctl r_ctl,u32 parm_offset)210 void 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 }
220 EXPORT_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  */
fc_fc4_conf_lport_params(struct fc_lport * lport,enum fc_fh_type type)229 void 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 
fc_lport_iterate(void (* notify)(struct fc_lport *,void *),void * arg)241 void 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 }
250 EXPORT_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  */
fc_fc4_register_provider(enum fc_fh_type type,struct fc4_prov * prov)259 int 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 }
275 EXPORT_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  */
fc_fc4_deregister_provider(enum fc_fh_type type,struct fc4_prov * prov)282 void 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 }
293 EXPORT_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  */
fc_fc4_add_lport(struct fc_lport * lport)299 void 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  */
fc_fc4_del_lport(struct fc_lport * lport)312 void 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