discovery.c

  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	strscpy(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_STATUS_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_STATUS_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		if (r->disc_addr.trtype == NVMF_TRTYPE_PCI)
228			continue;
229
230		nvmet_format_discovery_entry(hdr, r,
231				NVME_DISC_SUBSYS_NAME,
232				r->disc_addr.traddr,
233				NVME_NQN_DISC, numrec);
234		numrec++;
235	}
236
237	hdr->genctr = cpu_to_le64(nvmet_genctr);
238	hdr->numrec = cpu_to_le64(numrec);
239	hdr->recfmt = cpu_to_le16(0);
240
241	nvmet_clear_aen_bit(req, NVME_AEN_BIT_DISC_CHANGE);
242
243	up_read(&nvmet_config_sem);
244
245	status = nvmet_copy_to_sgl(req, 0, buffer + offset, data_len);
246	kfree(buffer);
247out:
248	nvmet_req_complete(req, status);
249}
250
251static void nvmet_execute_disc_identify(struct nvmet_req *req)
252{
253	struct nvmet_ctrl *ctrl = req->sq->ctrl;
254	struct nvme_id_ctrl *id;
255	u16 status = 0;
256
257	if (!nvmet_check_transfer_len(req, NVME_IDENTIFY_DATA_SIZE))
258		return;
259
260	if (req->cmd->identify.cns != NVME_ID_CNS_CTRL) {
261		req->error_loc = offsetof(struct nvme_identify, cns);
262		status = NVME_SC_INVALID_FIELD | NVME_STATUS_DNR;
263		goto out;
264	}
265
266	id = kzalloc(sizeof(*id), GFP_KERNEL);
267	if (!id) {
268		status = NVME_SC_INTERNAL;
269		goto out;
270	}
271
272	memcpy(id->sn, ctrl->subsys->serial, NVMET_SN_MAX_SIZE);
273	memset(id->fr, ' ', sizeof(id->fr));
274	memcpy_and_pad(id->mn, sizeof(id->mn), ctrl->subsys->model_number,
275		       strlen(ctrl->subsys->model_number), ' ');
276	memcpy_and_pad(id->fr, sizeof(id->fr),
277		       UTS_RELEASE, strlen(UTS_RELEASE), ' ');
278
279	id->cntrltype = NVME_CTRL_DISC;
280
281	/* no limit on data transfer sizes for now */
282	id->mdts = 0;
283	id->cntlid = cpu_to_le16(ctrl->cntlid);
284	id->ver = cpu_to_le32(ctrl->subsys->ver);
285	id->lpa = (1 << 2);
286
287	/* no enforcement soft-limit for maxcmd - pick arbitrary high value */
288	id->maxcmd = cpu_to_le16(NVMET_MAX_CMD(ctrl));
289
290	id->sgls = cpu_to_le32(1 << 0);	/* we always support SGLs */
291	if (ctrl->ops->flags & NVMF_KEYED_SGLS)
292		id->sgls |= cpu_to_le32(1 << 2);
293	if (req->port->inline_data_size)
294		id->sgls |= cpu_to_le32(1 << 20);
295
296	id->oaes = cpu_to_le32(NVMET_DISC_AEN_CFG_OPTIONAL);
297
298	strscpy(id->subnqn, ctrl->subsys->subsysnqn, sizeof(id->subnqn));
299
300	status = nvmet_copy_to_sgl(req, 0, id, sizeof(*id));
301
302	kfree(id);
303out:
304	nvmet_req_complete(req, status);
305}
306
307static void nvmet_execute_disc_set_features(struct nvmet_req *req)
308{
309	u32 cdw10 = le32_to_cpu(req->cmd->common.cdw10);
310	u16 stat;
311
312	if (!nvmet_check_transfer_len(req, 0))
313		return;
314
315	switch (cdw10 & 0xff) {
316	case NVME_FEAT_KATO:
317		stat = nvmet_set_feat_kato(req);
318		break;
319	case NVME_FEAT_ASYNC_EVENT:
320		stat = nvmet_set_feat_async_event(req,
321						  NVMET_DISC_AEN_CFG_OPTIONAL);
322		break;
323	default:
324		req->error_loc =
325			offsetof(struct nvme_common_command, cdw10);
326		stat = NVME_SC_INVALID_FIELD | NVME_STATUS_DNR;
327		break;
328	}
329
330	nvmet_req_complete(req, stat);
331}
332
333static void nvmet_execute_disc_get_features(struct nvmet_req *req)
334{
335	u32 cdw10 = le32_to_cpu(req->cmd->common.cdw10);
336	u16 stat = 0;
337
338	if (!nvmet_check_transfer_len(req, 0))
339		return;
340
341	switch (cdw10 & 0xff) {
342	case NVME_FEAT_KATO:
343		nvmet_get_feat_kato(req);
344		break;
345	case NVME_FEAT_ASYNC_EVENT:
346		nvmet_get_feat_async_event(req);
347		break;
348	default:
349		req->error_loc =
350			offsetof(struct nvme_common_command, cdw10);
351		stat = NVME_SC_INVALID_FIELD | NVME_STATUS_DNR;
352		break;
353	}
354
355	nvmet_req_complete(req, stat);
356}
357
358u32 nvmet_discovery_cmd_data_len(struct nvmet_req *req)
359{
360	struct nvme_command *cmd = req->cmd;
361
362	switch (cmd->common.opcode) {
363	case nvme_admin_get_log_page:
364		return nvmet_get_log_page_len(req->cmd);
365	case nvme_admin_identify:
366		return NVME_IDENTIFY_DATA_SIZE;
367	default:
368		return 0;
369	}
370}
371
372u16 nvmet_parse_discovery_cmd(struct nvmet_req *req)
373{
374	struct nvme_command *cmd = req->cmd;
375
376	if (unlikely(!(req->sq->ctrl->csts & NVME_CSTS_RDY))) {
377		pr_err("got cmd %d while not ready\n",
378		       cmd->common.opcode);
379		req->error_loc =
380			offsetof(struct nvme_common_command, opcode);
381		return NVME_SC_INVALID_OPCODE | NVME_STATUS_DNR;
382	}
383
384	switch (cmd->common.opcode) {
385	case nvme_admin_set_features:
386		req->execute = nvmet_execute_disc_set_features;
387		return 0;
388	case nvme_admin_get_features:
389		req->execute = nvmet_execute_disc_get_features;
390		return 0;
391	case nvme_admin_async_event:
392		req->execute = nvmet_execute_async_event;
393		return 0;
394	case nvme_admin_keep_alive:
395		req->execute = nvmet_execute_keep_alive;
396		return 0;
397	case nvme_admin_get_log_page:
398		req->execute = nvmet_execute_disc_get_log_page;
399		return 0;
400	case nvme_admin_identify:
401		req->execute = nvmet_execute_disc_identify;
402		return 0;
403	default:
404		pr_debug("unhandled cmd %d\n", cmd->common.opcode);
405		req->error_loc = offsetof(struct nvme_common_command, opcode);
406		return NVME_SC_INVALID_OPCODE | NVME_STATUS_DNR;
407	}
408
409}
410
411int __init nvmet_init_discovery(void)
412{
413	nvmet_disc_subsys =
414		nvmet_subsys_alloc(NVME_DISC_SUBSYS_NAME, NVME_NQN_CURR);
415	return PTR_ERR_OR_ZERO(nvmet_disc_subsys);
416}
417
418void nvmet_exit_discovery(void)
419{
420	nvmet_subsys_put(nvmet_disc_subsys);
421}