1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Discovery service for the NVMe over Fabrics target.
4 * Copyright (C) 2016 Intel Corporation. All rights reserved.
5 */
6#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7#include <linux/slab.h>
8#include <generated/utsrelease.h>
9#include "nvmet.h"
10
11struct nvmet_subsys *nvmet_disc_subsys;
12
13static u64 nvmet_genctr;
14
15static void __nvmet_disc_changed(struct nvmet_port *port,
16				 struct nvmet_ctrl *ctrl)
17{
18	if (ctrl->port != port)
19		return;
20
21	if (nvmet_aen_bit_disabled(ctrl, NVME_AEN_BIT_DISC_CHANGE))
22		return;
23
24	nvmet_add_async_event(ctrl, NVME_AER_NOTICE,
25			      NVME_AER_NOTICE_DISC_CHANGED, NVME_LOG_DISC);
26}
27
28void nvmet_port_disc_changed(struct nvmet_port *port,
29			     struct nvmet_subsys *subsys)
30{
31	struct nvmet_ctrl *ctrl;
32
33	lockdep_assert_held(&nvmet_config_sem);
34	nvmet_genctr++;
35
36	mutex_lock(&nvmet_disc_subsys->lock);
37	list_for_each_entry(ctrl, &nvmet_disc_subsys->ctrls, subsys_entry) {
38		if (subsys && !nvmet_host_allowed(subsys, ctrl->hostnqn))
39			continue;
40
41		__nvmet_disc_changed(port, ctrl);
42	}
43	mutex_unlock(&nvmet_disc_subsys->lock);
44
45	/* If transport can signal change, notify transport */
46	if (port->tr_ops && port->tr_ops->discovery_chg)
47		port->tr_ops->discovery_chg(port);
48}
49
50static void __nvmet_subsys_disc_changed(struct nvmet_port *port,
51					struct nvmet_subsys *subsys,
52					struct nvmet_host *host)
53{
54	struct nvmet_ctrl *ctrl;
55
56	mutex_lock(&nvmet_disc_subsys->lock);
57	list_for_each_entry(ctrl, &nvmet_disc_subsys->ctrls, subsys_entry) {
58		if (host && strcmp(nvmet_host_name(host), ctrl->hostnqn))
59			continue;
60
61		__nvmet_disc_changed(port, ctrl);
62	}
63	mutex_unlock(&nvmet_disc_subsys->lock);
64}
65
66void nvmet_subsys_disc_changed(struct nvmet_subsys *subsys,
67			       struct nvmet_host *host)
68{
69	struct nvmet_port *port;
70	struct nvmet_subsys_link *s;
71
72	lockdep_assert_held(&nvmet_config_sem);
73	nvmet_genctr++;
74
75	list_for_each_entry(port, nvmet_ports, global_entry)
76		list_for_each_entry(s, &port->subsystems, entry) {
77			if (s->subsys != subsys)
78				continue;
79			__nvmet_subsys_disc_changed(port, subsys, host);
80		}
81}
82
83void nvmet_referral_enable(struct nvmet_port *parent, struct nvmet_port *port)
84{
85	down_write(&nvmet_config_sem);
86	if (list_empty(&port->entry)) {
87		list_add_tail(&port->entry, &parent->referrals);
88		port->enabled = true;
89		nvmet_port_disc_changed(parent, NULL);
90	}
91	up_write(&nvmet_config_sem);
92}
93
94void nvmet_referral_disable(struct nvmet_port *parent, struct nvmet_port *port)
95{
96	down_write(&nvmet_config_sem);
97	if (!list_empty(&port->entry)) {
98		port->enabled = false;
99		list_del_init(&port->entry);
100		nvmet_port_disc_changed(parent, NULL);
101	}
102	up_write(&nvmet_config_sem);
103}
104
105static void nvmet_format_discovery_entry(struct nvmf_disc_rsp_page_hdr *hdr,
106		struct nvmet_port *port, char *subsys_nqn, char *traddr,
107		u8 type, u32 numrec)
108{
109	struct nvmf_disc_rsp_page_entry *e = &hdr->entries[numrec];
110
111	e->trtype = port->disc_addr.trtype;
112	e->adrfam = port->disc_addr.adrfam;
113	e->treq = port->disc_addr.treq;
114	e->portid = port->disc_addr.portid;
115	/* we support only dynamic controllers */
116	e->cntlid = cpu_to_le16(NVME_CNTLID_DYNAMIC);
117	e->asqsz = cpu_to_le16(NVME_AQ_DEPTH);
118	e->subtype = type;
119	memcpy(e->trsvcid, port->disc_addr.trsvcid, NVMF_TRSVCID_SIZE);
120	memcpy(e->traddr, traddr, NVMF_TRADDR_SIZE);
121	memcpy(e->tsas.common, port->disc_addr.tsas.common, NVMF_TSAS_SIZE);
122	strncpy(e->subnqn, subsys_nqn, NVMF_NQN_SIZE);
123}
124
125/*
126 * nvmet_set_disc_traddr - set a correct discovery log entry traddr
127 *
128 * IP based transports (e.g RDMA) can listen on "any" ipv4/ipv6 addresses
129 * (INADDR_ANY or IN6ADDR_ANY_INIT). The discovery log page traddr reply
130 * must not contain that "any" IP address. If the transport implements
131 * .disc_traddr, use it. this callback will set the discovery traddr
132 * from the req->port address in case the port in question listens
133 * "any" IP address.
134 */
135static void nvmet_set_disc_traddr(struct nvmet_req *req, struct nvmet_port *port,
136		char *traddr)
137{
138	if (req->ops->disc_traddr)
139		req->ops->disc_traddr(req, port, traddr);
140	else
141		memcpy(traddr, port->disc_addr.traddr, NVMF_TRADDR_SIZE);
142}
143
144static size_t discovery_log_entries(struct nvmet_req *req)
145{
146	struct nvmet_ctrl *ctrl = req->sq->ctrl;
147	struct nvmet_subsys_link *p;
148	struct nvmet_port *r;
149	size_t entries = 1;
150
151	list_for_each_entry(p, &req->port->subsystems, entry) {
152		if (!nvmet_host_allowed(p->subsys, ctrl->hostnqn))
153			continue;
154		entries++;
155	}
156	list_for_each_entry(r, &req->port->referrals, entry)
157		entries++;
158	return entries;
159}
160
161static void nvmet_execute_disc_get_log_page(struct nvmet_req *req)
162{
163	const int entry_size = sizeof(struct nvmf_disc_rsp_page_entry);
164	struct nvmet_ctrl *ctrl = req->sq->ctrl;
165	struct nvmf_disc_rsp_page_hdr *hdr;
166	u64 offset = nvmet_get_log_page_offset(req->cmd);
167	size_t data_len = nvmet_get_log_page_len(req->cmd);
168	size_t alloc_len;
169	struct nvmet_subsys_link *p;
170	struct nvmet_port *r;
171	u32 numrec = 0;
172	u16 status = 0;
173	void *buffer;
174	char traddr[NVMF_TRADDR_SIZE];
175
176	if (!nvmet_check_transfer_len(req, data_len))
177		return;
178
179	if (req->cmd->get_log_page.lid != NVME_LOG_DISC) {
180		req->error_loc =
181			offsetof(struct nvme_get_log_page_command, lid);
182		status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
183		goto out;
184	}
185
186	/* Spec requires dword aligned offsets */
187	if (offset & 0x3) {
188		req->error_loc =
189			offsetof(struct nvme_get_log_page_command, lpo);
190		status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
191		goto out;
192	}
193
194	/*
195	 * Make sure we're passing at least a buffer of response header size.
196	 * If host provided data len is less than the header size, only the
197	 * number of bytes requested by host will be sent to host.
198	 */
199	down_read(&nvmet_config_sem);
200	alloc_len = sizeof(*hdr) + entry_size * discovery_log_entries(req);
201	buffer = kzalloc(alloc_len, GFP_KERNEL);
202	if (!buffer) {
203		up_read(&nvmet_config_sem);
204		status = NVME_SC_INTERNAL;
205		goto out;
206	}
207	hdr = buffer;
208
209	nvmet_set_disc_traddr(req, req->port, traddr);
210
211	nvmet_format_discovery_entry(hdr, req->port,
212				     nvmet_disc_subsys->subsysnqn,
213				     traddr, NVME_NQN_CURR, numrec);
214	numrec++;
215
216	list_for_each_entry(p, &req->port->subsystems, entry) {
217		if (!nvmet_host_allowed(p->subsys, ctrl->hostnqn))
218			continue;
219
220		nvmet_format_discovery_entry(hdr, req->port,
221				p->subsys->subsysnqn, traddr,
222				NVME_NQN_NVME, numrec);
223		numrec++;
224	}
225
226	list_for_each_entry(r, &req->port->referrals, entry) {
227		nvmet_format_discovery_entry(hdr, r,
228				NVME_DISC_SUBSYS_NAME,
229				r->disc_addr.traddr,
230				NVME_NQN_DISC, numrec);
231		numrec++;
232	}
233
234	hdr->genctr = cpu_to_le64(nvmet_genctr);
235	hdr->numrec = cpu_to_le64(numrec);
236	hdr->recfmt = cpu_to_le16(0);
237
238	nvmet_clear_aen_bit(req, NVME_AEN_BIT_DISC_CHANGE);
239
240	up_read(&nvmet_config_sem);
241
242	status = nvmet_copy_to_sgl(req, 0, buffer + offset, data_len);
243	kfree(buffer);
244out:
245	nvmet_req_complete(req, status);
246}
247
248static void nvmet_execute_disc_identify(struct nvmet_req *req)
249{
250	struct nvmet_ctrl *ctrl = req->sq->ctrl;
251	struct nvme_id_ctrl *id;
252	u16 status = 0;
253
254	if (!nvmet_check_transfer_len(req, NVME_IDENTIFY_DATA_SIZE))
255		return;
256
257	if (req->cmd->identify.cns != NVME_ID_CNS_CTRL) {
258		req->error_loc = offsetof(struct nvme_identify, cns);
259		status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
260		goto out;
261	}
262
263	id = kzalloc(sizeof(*id), GFP_KERNEL);
264	if (!id) {
265		status = NVME_SC_INTERNAL;
266		goto out;
267	}
268
269	memcpy(id->sn, ctrl->subsys->serial, NVMET_SN_MAX_SIZE);
270	memset(id->fr, ' ', sizeof(id->fr));
271	memcpy_and_pad(id->mn, sizeof(id->mn), ctrl->subsys->model_number,
272		       strlen(ctrl->subsys->model_number), ' ');
273	memcpy_and_pad(id->fr, sizeof(id->fr),
274		       UTS_RELEASE, strlen(UTS_RELEASE), ' ');
275
276	id->cntrltype = NVME_CTRL_DISC;
277
278	/* no limit on data transfer sizes for now */
279	id->mdts = 0;
280	id->cntlid = cpu_to_le16(ctrl->cntlid);
281	id->ver = cpu_to_le32(ctrl->subsys->ver);
282	id->lpa = (1 << 2);
283
284	/* no enforcement soft-limit for maxcmd - pick arbitrary high value */
285	id->maxcmd = cpu_to_le16(NVMET_MAX_CMD(ctrl));
286
287	id->sgls = cpu_to_le32(1 << 0);	/* we always support SGLs */
288	if (ctrl->ops->flags & NVMF_KEYED_SGLS)
289		id->sgls |= cpu_to_le32(1 << 2);
290	if (req->port->inline_data_size)
291		id->sgls |= cpu_to_le32(1 << 20);
292
293	id->oaes = cpu_to_le32(NVMET_DISC_AEN_CFG_OPTIONAL);
294
295	strscpy(id->subnqn, ctrl->subsys->subsysnqn, sizeof(id->subnqn));
296
297	status = nvmet_copy_to_sgl(req, 0, id, sizeof(*id));
298
299	kfree(id);
300out:
301	nvmet_req_complete(req, status);
302}
303
304static void nvmet_execute_disc_set_features(struct nvmet_req *req)
305{
306	u32 cdw10 = le32_to_cpu(req->cmd->common.cdw10);
307	u16 stat;
308
309	if (!nvmet_check_transfer_len(req, 0))
310		return;
311
312	switch (cdw10 & 0xff) {
313	case NVME_FEAT_KATO:
314		stat = nvmet_set_feat_kato(req);
315		break;
316	case NVME_FEAT_ASYNC_EVENT:
317		stat = nvmet_set_feat_async_event(req,
318						  NVMET_DISC_AEN_CFG_OPTIONAL);
319		break;
320	default:
321		req->error_loc =
322			offsetof(struct nvme_common_command, cdw10);
323		stat = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
324		break;
325	}
326
327	nvmet_req_complete(req, stat);
328}
329
330static void nvmet_execute_disc_get_features(struct nvmet_req *req)
331{
332	u32 cdw10 = le32_to_cpu(req->cmd->common.cdw10);
333	u16 stat = 0;
334
335	if (!nvmet_check_transfer_len(req, 0))
336		return;
337
338	switch (cdw10 & 0xff) {
339	case NVME_FEAT_KATO:
340		nvmet_get_feat_kato(req);
341		break;
342	case NVME_FEAT_ASYNC_EVENT:
343		nvmet_get_feat_async_event(req);
344		break;
345	default:
346		req->error_loc =
347			offsetof(struct nvme_common_command, cdw10);
348		stat = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
349		break;
350	}
351
352	nvmet_req_complete(req, stat);
353}
354
355u16 nvmet_parse_discovery_cmd(struct nvmet_req *req)
356{
357	struct nvme_command *cmd = req->cmd;
358
359	if (unlikely(!(req->sq->ctrl->csts & NVME_CSTS_RDY))) {
360		pr_err("got cmd %d while not ready\n",
361		       cmd->common.opcode);
362		req->error_loc =
363			offsetof(struct nvme_common_command, opcode);
364		return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
365	}
366
367	switch (cmd->common.opcode) {
368	case nvme_admin_set_features:
369		req->execute = nvmet_execute_disc_set_features;
370		return 0;
371	case nvme_admin_get_features:
372		req->execute = nvmet_execute_disc_get_features;
373		return 0;
374	case nvme_admin_async_event:
375		req->execute = nvmet_execute_async_event;
376		return 0;
377	case nvme_admin_keep_alive:
378		req->execute = nvmet_execute_keep_alive;
379		return 0;
380	case nvme_admin_get_log_page:
381		req->execute = nvmet_execute_disc_get_log_page;
382		return 0;
383	case nvme_admin_identify:
384		req->execute = nvmet_execute_disc_identify;
385		return 0;
386	default:
387		pr_debug("unhandled cmd %d\n", cmd->common.opcode);
388		req->error_loc = offsetof(struct nvme_common_command, opcode);
389		return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
390	}
391
392}
393
394int __init nvmet_init_discovery(void)
395{
396	nvmet_disc_subsys =
397		nvmet_subsys_alloc(NVME_DISC_SUBSYS_NAME, NVME_NQN_CURR);
398	return PTR_ERR_OR_ZERO(nvmet_disc_subsys);
399}
400
401void nvmet_exit_discovery(void)
402{
403	nvmet_subsys_put(nvmet_disc_subsys);
404}
405