1 files changed, 404 insertions, 0 deletions

diff --git a/drivers/nvme/target/discovery.c b/drivers/nvme/target/discovery.c
new file mode 100644
index 000000000..668d257fa
--- /dev/null
+++ b/drivers/nvme/target/discovery.c
@@ -0,0 +1,404 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Discovery service for the NVMe over Fabrics target.
+ * Copyright (C) 2016 Intel Corporation. All rights reserved.
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/slab.h>
+#include <generated/utsrelease.h>
+#include "nvmet.h"
+
+struct nvmet_subsys *nvmet_disc_subsys;
+
+static u64 nvmet_genctr;
+
+static void __nvmet_disc_changed(struct nvmet_port *port,
+				 struct nvmet_ctrl *ctrl)
+{
+	if (ctrl->port != port)
+		return;
+
+	if (nvmet_aen_bit_disabled(ctrl, NVME_AEN_BIT_DISC_CHANGE))
+		return;
+
+	nvmet_add_async_event(ctrl, NVME_AER_TYPE_NOTICE,
+			      NVME_AER_NOTICE_DISC_CHANGED, NVME_LOG_DISC);
+}
+
+void nvmet_port_disc_changed(struct nvmet_port *port,
+			     struct nvmet_subsys *subsys)
+{
+	struct nvmet_ctrl *ctrl;
+
+	lockdep_assert_held(&nvmet_config_sem);
+	nvmet_genctr++;
+
+	mutex_lock(&nvmet_disc_subsys->lock);
+	list_for_each_entry(ctrl, &nvmet_disc_subsys->ctrls, subsys_entry) {
+		if (subsys && !nvmet_host_allowed(subsys, ctrl->hostnqn))
+			continue;
+
+		__nvmet_disc_changed(port, ctrl);
+	}
+	mutex_unlock(&nvmet_disc_subsys->lock);
+
+	/* If transport can signal change, notify transport */
+	if (port->tr_ops && port->tr_ops->discovery_chg)
+		port->tr_ops->discovery_chg(port);
+}
+
+static void __nvmet_subsys_disc_changed(struct nvmet_port *port,
+					struct nvmet_subsys *subsys,
+					struct nvmet_host *host)
+{
+	struct nvmet_ctrl *ctrl;
+
+	mutex_lock(&nvmet_disc_subsys->lock);
+	list_for_each_entry(ctrl, &nvmet_disc_subsys->ctrls, subsys_entry) {
+		if (host && strcmp(nvmet_host_name(host), ctrl->hostnqn))
+			continue;
+
+		__nvmet_disc_changed(port, ctrl);
+	}
+	mutex_unlock(&nvmet_disc_subsys->lock);
+}
+
+void nvmet_subsys_disc_changed(struct nvmet_subsys *subsys,
+			       struct nvmet_host *host)
+{
+	struct nvmet_port *port;
+	struct nvmet_subsys_link *s;
+
+	lockdep_assert_held(&nvmet_config_sem);
+	nvmet_genctr++;
+
+	list_for_each_entry(port, nvmet_ports, global_entry)
+		list_for_each_entry(s, &port->subsystems, entry) {
+			if (s->subsys != subsys)
+				continue;
+			__nvmet_subsys_disc_changed(port, subsys, host);
+		}
+}
+
+void nvmet_referral_enable(struct nvmet_port *parent, struct nvmet_port *port)
+{
+	down_write(&nvmet_config_sem);
+	if (list_empty(&port->entry)) {
+		list_add_tail(&port->entry, &parent->referrals);
+		port->enabled = true;
+		nvmet_port_disc_changed(parent, NULL);
+	}
+	up_write(&nvmet_config_sem);
+}
+
+void nvmet_referral_disable(struct nvmet_port *parent, struct nvmet_port *port)
+{
+	down_write(&nvmet_config_sem);
+	if (!list_empty(&port->entry)) {
+		port->enabled = false;
+		list_del_init(&port->entry);
+		nvmet_port_disc_changed(parent, NULL);
+	}
+	up_write(&nvmet_config_sem);
+}
+
+static void nvmet_format_discovery_entry(struct nvmf_disc_rsp_page_hdr *hdr,
+		struct nvmet_port *port, char *subsys_nqn, char *traddr,
+		u8 type, u32 numrec)
+{
+	struct nvmf_disc_rsp_page_entry *e = &hdr->entries[numrec];
+
+	e->trtype = port->disc_addr.trtype;
+	e->adrfam = port->disc_addr.adrfam;
+	e->treq = port->disc_addr.treq;
+	e->portid = port->disc_addr.portid;
+	/* we support only dynamic controllers */
+	e->cntlid = cpu_to_le16(NVME_CNTLID_DYNAMIC);
+	e->asqsz = cpu_to_le16(NVME_AQ_DEPTH);
+	e->subtype = type;
+	memcpy(e->trsvcid, port->disc_addr.trsvcid, NVMF_TRSVCID_SIZE);
+	memcpy(e->traddr, traddr, NVMF_TRADDR_SIZE);
+	memcpy(e->tsas.common, port->disc_addr.tsas.common, NVMF_TSAS_SIZE);
+	strncpy(e->subnqn, subsys_nqn, NVMF_NQN_SIZE);
+}
+
+/*
+ * nvmet_set_disc_traddr - set a correct discovery log entry traddr
+ *
+ * IP based transports (e.g RDMA) can listen on "any" ipv4/ipv6 addresses
+ * (INADDR_ANY or IN6ADDR_ANY_INIT). The discovery log page traddr reply
+ * must not contain that "any" IP address. If the transport implements
+ * .disc_traddr, use it. this callback will set the discovery traddr
+ * from the req->port address in case the port in question listens
+ * "any" IP address.
+ */
+static void nvmet_set_disc_traddr(struct nvmet_req *req, struct nvmet_port *port,
+		char *traddr)
+{
+	if (req->ops->disc_traddr)
+		req->ops->disc_traddr(req, port, traddr);
+	else
+		memcpy(traddr, port->disc_addr.traddr, NVMF_TRADDR_SIZE);
+}
+
+static size_t discovery_log_entries(struct nvmet_req *req)
+{
+	struct nvmet_ctrl *ctrl = req->sq->ctrl;
+	struct nvmet_subsys_link *p;
+	struct nvmet_port *r;
+	size_t entries = 1;
+
+	list_for_each_entry(p, &req->port->subsystems, entry) {
+		if (!nvmet_host_allowed(p->subsys, ctrl->hostnqn))
+			continue;
+		entries++;
+	}
+	list_for_each_entry(r, &req->port->referrals, entry)
+		entries++;
+	return entries;
+}
+
+static void nvmet_execute_disc_get_log_page(struct nvmet_req *req)
+{
+	const int entry_size = sizeof(struct nvmf_disc_rsp_page_entry);
+	struct nvmet_ctrl *ctrl = req->sq->ctrl;
+	struct nvmf_disc_rsp_page_hdr *hdr;
+	u64 offset = nvmet_get_log_page_offset(req->cmd);
+	size_t data_len = nvmet_get_log_page_len(req->cmd);
+	size_t alloc_len;
+	struct nvmet_subsys_link *p;
+	struct nvmet_port *r;
+	u32 numrec = 0;
+	u16 status = 0;
+	void *buffer;
+	char traddr[NVMF_TRADDR_SIZE];
+
+	if (!nvmet_check_transfer_len(req, data_len))
+		return;
+
+	if (req->cmd->get_log_page.lid != NVME_LOG_DISC) {
+		req->error_loc =
+			offsetof(struct nvme_get_log_page_command, lid);
+		status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
+		goto out;
+	}
+
+	/* Spec requires dword aligned offsets */
+	if (offset & 0x3) {
+		req->error_loc =
+			offsetof(struct nvme_get_log_page_command, lpo);
+		status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
+		goto out;
+	}
+
+	/*
+	 * Make sure we're passing at least a buffer of response header size.
+	 * If host provided data len is less than the header size, only the
+	 * number of bytes requested by host will be sent to host.
+	 */
+	down_read(&nvmet_config_sem);
+	alloc_len = sizeof(*hdr) + entry_size * discovery_log_entries(req);
+	buffer = kzalloc(alloc_len, GFP_KERNEL);
+	if (!buffer) {
+		up_read(&nvmet_config_sem);
+		status = NVME_SC_INTERNAL;
+		goto out;
+	}
+	hdr = buffer;
+
+	nvmet_set_disc_traddr(req, req->port, traddr);
+
+	nvmet_format_discovery_entry(hdr, req->port,
+				     nvmet_disc_subsys->subsysnqn,
+				     traddr, NVME_NQN_CURR, numrec);
+	numrec++;
+
+	list_for_each_entry(p, &req->port->subsystems, entry) {
+		if (!nvmet_host_allowed(p->subsys, ctrl->hostnqn))
+			continue;
+
+		nvmet_format_discovery_entry(hdr, req->port,
+				p->subsys->subsysnqn, traddr,
+				NVME_NQN_NVME, numrec);
+		numrec++;
+	}
+
+	list_for_each_entry(r, &req->port->referrals, entry) {
+		nvmet_format_discovery_entry(hdr, r,
+				NVME_DISC_SUBSYS_NAME,
+				r->disc_addr.traddr,
+				NVME_NQN_DISC, numrec);
+		numrec++;
+	}
+
+	hdr->genctr = cpu_to_le64(nvmet_genctr);
+	hdr->numrec = cpu_to_le64(numrec);
+	hdr->recfmt = cpu_to_le16(0);
+
+	nvmet_clear_aen_bit(req, NVME_AEN_BIT_DISC_CHANGE);
+
+	up_read(&nvmet_config_sem);
+
+	status = nvmet_copy_to_sgl(req, 0, buffer + offset, data_len);
+	kfree(buffer);
+out:
+	nvmet_req_complete(req, status);
+}
+
+static void nvmet_execute_disc_identify(struct nvmet_req *req)
+{
+	struct nvmet_ctrl *ctrl = req->sq->ctrl;
+	struct nvme_id_ctrl *id;
+	u16 status = 0;
+
+	if (!nvmet_check_transfer_len(req, NVME_IDENTIFY_DATA_SIZE))
+		return;
+
+	if (req->cmd->identify.cns != NVME_ID_CNS_CTRL) {
+		req->error_loc = offsetof(struct nvme_identify, cns);
+		status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
+		goto out;
+	}
+
+	id = kzalloc(sizeof(*id), GFP_KERNEL);
+	if (!id) {
+		status = NVME_SC_INTERNAL;
+		goto out;
+	}
+
+	memcpy(id->sn, ctrl->subsys->serial, NVMET_SN_MAX_SIZE);
+	memset(id->fr, ' ', sizeof(id->fr));
+	memcpy_and_pad(id->mn, sizeof(id->mn), ctrl->subsys->model_number,
+		       strlen(ctrl->subsys->model_number), ' ');
+	memcpy_and_pad(id->fr, sizeof(id->fr),
+		       UTS_RELEASE, strlen(UTS_RELEASE), ' ');
+
+	id->cntrltype = NVME_CTRL_DISC;
+
+	/* no limit on data transfer sizes for now */
+	id->mdts = 0;
+	id->cntlid = cpu_to_le16(ctrl->cntlid);
+	id->ver = cpu_to_le32(ctrl->subsys->ver);
+	id->lpa = (1 << 2);
+
+	/* no enforcement soft-limit for maxcmd - pick arbitrary high value */
+	id->maxcmd = cpu_to_le16(NVMET_MAX_CMD);
+
+	id->sgls = cpu_to_le32(1 << 0);	/* we always support SGLs */
+	if (ctrl->ops->flags & NVMF_KEYED_SGLS)
+		id->sgls |= cpu_to_le32(1 << 2);
+	if (req->port->inline_data_size)
+		id->sgls |= cpu_to_le32(1 << 20);
+
+	id->oaes = cpu_to_le32(NVMET_DISC_AEN_CFG_OPTIONAL);
+
+	strscpy(id->subnqn, ctrl->subsys->subsysnqn, sizeof(id->subnqn));
+
+	status = nvmet_copy_to_sgl(req, 0, id, sizeof(*id));
+
+	kfree(id);
+out:
+	nvmet_req_complete(req, status);
+}
+
+static void nvmet_execute_disc_set_features(struct nvmet_req *req)
+{
+	u32 cdw10 = le32_to_cpu(req->cmd->common.cdw10);
+	u16 stat;
+
+	if (!nvmet_check_transfer_len(req, 0))
+		return;
+
+	switch (cdw10 & 0xff) {
+	case NVME_FEAT_KATO:
+		stat = nvmet_set_feat_kato(req);
+		break;
+	case NVME_FEAT_ASYNC_EVENT:
+		stat = nvmet_set_feat_async_event(req,
+						  NVMET_DISC_AEN_CFG_OPTIONAL);
+		break;
+	default:
+		req->error_loc =
+			offsetof(struct nvme_common_command, cdw10);
+		stat = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
+		break;
+	}
+
+	nvmet_req_complete(req, stat);
+}
+
+static void nvmet_execute_disc_get_features(struct nvmet_req *req)
+{
+	u32 cdw10 = le32_to_cpu(req->cmd->common.cdw10);
+	u16 stat = 0;
+
+	if (!nvmet_check_transfer_len(req, 0))
+		return;
+
+	switch (cdw10 & 0xff) {
+	case NVME_FEAT_KATO:
+		nvmet_get_feat_kato(req);
+		break;
+	case NVME_FEAT_ASYNC_EVENT:
+		nvmet_get_feat_async_event(req);
+		break;
+	default:
+		req->error_loc =
+			offsetof(struct nvme_common_command, cdw10);
+		stat = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
+		break;
+	}
+
+	nvmet_req_complete(req, stat);
+}
+
+u16 nvmet_parse_discovery_cmd(struct nvmet_req *req)
+{
+	struct nvme_command *cmd = req->cmd;
+
+	if (unlikely(!(req->sq->ctrl->csts & NVME_CSTS_RDY))) {
+		pr_err("got cmd %d while not ready\n",
+		       cmd->common.opcode);
+		req->error_loc =
+			offsetof(struct nvme_common_command, opcode);
+		return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
+	}
+
+	switch (cmd->common.opcode) {
+	case nvme_admin_set_features:
+		req->execute = nvmet_execute_disc_set_features;
+		return 0;
+	case nvme_admin_get_features:
+		req->execute = nvmet_execute_disc_get_features;
+		return 0;
+	case nvme_admin_async_event:
+		req->execute = nvmet_execute_async_event;
+		return 0;
+	case nvme_admin_keep_alive:
+		req->execute = nvmet_execute_keep_alive;
+		return 0;
+	case nvme_admin_get_log_page:
+		req->execute = nvmet_execute_disc_get_log_page;
+		return 0;
+	case nvme_admin_identify:
+		req->execute = nvmet_execute_disc_identify;
+		return 0;
+	default:
+		pr_debug("unhandled cmd %d\n", cmd->common.opcode);
+		req->error_loc = offsetof(struct nvme_common_command, opcode);
+		return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
+	}
+
+}
+
+int __init nvmet_init_discovery(void)
+{
+	nvmet_disc_subsys =
+		nvmet_subsys_alloc(NVME_DISC_SUBSYS_NAME, NVME_NQN_CURR);
+	return PTR_ERR_OR_ZERO(nvmet_disc_subsys);
+}
+
+void nvmet_exit_discovery(void)
+{
+	nvmet_subsys_put(nvmet_disc_subsys);
+}