1 /*
2 * Discovery service for the NVMe over Fabrics target.
3 * Copyright (C) 2016 Intel Corporation. All rights reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License version
7 * 2 as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 */
14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15 #include <linux/slab.h>
16 #include <generated/utsrelease.h>
17 #include "nvmet.h"
18
19 struct nvmet_subsys *nvmet_disc_subsys;
20
21 u64 nvmet_genctr;
22
nvmet_referral_enable(struct nvmet_port * parent,struct nvmet_port * port)23 void nvmet_referral_enable(struct nvmet_port *parent, struct nvmet_port *port)
24 {
25 down_write(&nvmet_config_sem);
26 if (list_empty(&port->entry)) {
27 list_add_tail(&port->entry, &parent->referrals);
28 port->enabled = true;
29 nvmet_genctr++;
30 }
31 up_write(&nvmet_config_sem);
32 }
33
nvmet_referral_disable(struct nvmet_port * port)34 void nvmet_referral_disable(struct nvmet_port *port)
35 {
36 down_write(&nvmet_config_sem);
37 if (!list_empty(&port->entry)) {
38 port->enabled = false;
39 list_del_init(&port->entry);
40 nvmet_genctr++;
41 }
42 up_write(&nvmet_config_sem);
43 }
44
nvmet_format_discovery_entry(struct nvmf_disc_rsp_page_hdr * hdr,struct nvmet_port * port,char * subsys_nqn,char * traddr,u8 type,u32 numrec)45 static void nvmet_format_discovery_entry(struct nvmf_disc_rsp_page_hdr *hdr,
46 struct nvmet_port *port, char *subsys_nqn, char *traddr,
47 u8 type, u32 numrec)
48 {
49 struct nvmf_disc_rsp_page_entry *e = &hdr->entries[numrec];
50
51 e->trtype = port->disc_addr.trtype;
52 e->adrfam = port->disc_addr.adrfam;
53 e->treq = port->disc_addr.treq;
54 e->portid = port->disc_addr.portid;
55 /* we support only dynamic controllers */
56 e->cntlid = cpu_to_le16(NVME_CNTLID_DYNAMIC);
57 e->asqsz = cpu_to_le16(NVME_AQ_DEPTH);
58 e->subtype = type;
59 memcpy(e->trsvcid, port->disc_addr.trsvcid, NVMF_TRSVCID_SIZE);
60 memcpy(e->traddr, traddr, NVMF_TRADDR_SIZE);
61 memcpy(e->tsas.common, port->disc_addr.tsas.common, NVMF_TSAS_SIZE);
62 strncpy(e->subnqn, subsys_nqn, NVMF_NQN_SIZE);
63 }
64
65 /*
66 * nvmet_set_disc_traddr - set a correct discovery log entry traddr
67 *
68 * IP based transports (e.g RDMA) can listen on "any" ipv4/ipv6 addresses
69 * (INADDR_ANY or IN6ADDR_ANY_INIT). The discovery log page traddr reply
70 * must not contain that "any" IP address. If the transport implements
71 * .disc_traddr, use it. this callback will set the discovery traddr
72 * from the req->port address in case the port in question listens
73 * "any" IP address.
74 */
nvmet_set_disc_traddr(struct nvmet_req * req,struct nvmet_port * port,char * traddr)75 static void nvmet_set_disc_traddr(struct nvmet_req *req, struct nvmet_port *port,
76 char *traddr)
77 {
78 if (req->ops->disc_traddr)
79 req->ops->disc_traddr(req, port, traddr);
80 else
81 memcpy(traddr, port->disc_addr.traddr, NVMF_TRADDR_SIZE);
82 }
83
nvmet_execute_get_disc_log_page(struct nvmet_req * req)84 static void nvmet_execute_get_disc_log_page(struct nvmet_req *req)
85 {
86 const int entry_size = sizeof(struct nvmf_disc_rsp_page_entry);
87 struct nvmet_ctrl *ctrl = req->sq->ctrl;
88 struct nvmf_disc_rsp_page_hdr *hdr;
89 size_t data_len = nvmet_get_log_page_len(req->cmd);
90 size_t alloc_len = max(data_len, sizeof(*hdr));
91 int residual_len = data_len - sizeof(*hdr);
92 struct nvmet_subsys_link *p;
93 struct nvmet_port *r;
94 u32 numrec = 0;
95 u16 status = 0;
96
97 /*
98 * Make sure we're passing at least a buffer of response header size.
99 * If host provided data len is less than the header size, only the
100 * number of bytes requested by host will be sent to host.
101 */
102 hdr = kzalloc(alloc_len, GFP_KERNEL);
103 if (!hdr) {
104 status = NVME_SC_INTERNAL;
105 goto out;
106 }
107
108 down_read(&nvmet_config_sem);
109 list_for_each_entry(p, &req->port->subsystems, entry) {
110 if (!nvmet_host_allowed(req, p->subsys, ctrl->hostnqn))
111 continue;
112 if (residual_len >= entry_size) {
113 char traddr[NVMF_TRADDR_SIZE];
114
115 nvmet_set_disc_traddr(req, req->port, traddr);
116 nvmet_format_discovery_entry(hdr, req->port,
117 p->subsys->subsysnqn, traddr,
118 NVME_NQN_NVME, numrec);
119 residual_len -= entry_size;
120 }
121 numrec++;
122 }
123
124 list_for_each_entry(r, &req->port->referrals, entry) {
125 if (residual_len >= entry_size) {
126 nvmet_format_discovery_entry(hdr, r,
127 NVME_DISC_SUBSYS_NAME,
128 r->disc_addr.traddr,
129 NVME_NQN_DISC, numrec);
130 residual_len -= entry_size;
131 }
132 numrec++;
133 }
134
135 hdr->genctr = cpu_to_le64(nvmet_genctr);
136 hdr->numrec = cpu_to_le64(numrec);
137 hdr->recfmt = cpu_to_le16(0);
138
139 up_read(&nvmet_config_sem);
140
141 status = nvmet_copy_to_sgl(req, 0, hdr, data_len);
142 kfree(hdr);
143 out:
144 nvmet_req_complete(req, status);
145 }
146
nvmet_execute_identify_disc_ctrl(struct nvmet_req * req)147 static void nvmet_execute_identify_disc_ctrl(struct nvmet_req *req)
148 {
149 struct nvmet_ctrl *ctrl = req->sq->ctrl;
150 struct nvme_id_ctrl *id;
151 u16 status = 0;
152
153 id = kzalloc(sizeof(*id), GFP_KERNEL);
154 if (!id) {
155 status = NVME_SC_INTERNAL;
156 goto out;
157 }
158
159 memset(id->fr, ' ', sizeof(id->fr));
160 strncpy((char *)id->fr, UTS_RELEASE, sizeof(id->fr));
161
162 /* no limit on data transfer sizes for now */
163 id->mdts = 0;
164 id->cntlid = cpu_to_le16(ctrl->cntlid);
165 id->ver = cpu_to_le32(ctrl->subsys->ver);
166 id->lpa = (1 << 2);
167
168 /* no enforcement soft-limit for maxcmd - pick arbitrary high value */
169 id->maxcmd = cpu_to_le16(NVMET_MAX_CMD);
170
171 id->sgls = cpu_to_le32(1 << 0); /* we always support SGLs */
172 if (ctrl->ops->has_keyed_sgls)
173 id->sgls |= cpu_to_le32(1 << 2);
174 if (req->port->inline_data_size)
175 id->sgls |= cpu_to_le32(1 << 20);
176
177 strcpy(id->subnqn, ctrl->subsys->subsysnqn);
178
179 status = nvmet_copy_to_sgl(req, 0, id, sizeof(*id));
180
181 kfree(id);
182 out:
183 nvmet_req_complete(req, status);
184 }
185
nvmet_parse_discovery_cmd(struct nvmet_req * req)186 u16 nvmet_parse_discovery_cmd(struct nvmet_req *req)
187 {
188 struct nvme_command *cmd = req->cmd;
189
190 if (unlikely(!(req->sq->ctrl->csts & NVME_CSTS_RDY))) {
191 pr_err("got cmd %d while not ready\n",
192 cmd->common.opcode);
193 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
194 }
195
196 switch (cmd->common.opcode) {
197 case nvme_admin_get_log_page:
198 req->data_len = nvmet_get_log_page_len(cmd);
199
200 switch (cmd->get_log_page.lid) {
201 case NVME_LOG_DISC:
202 req->execute = nvmet_execute_get_disc_log_page;
203 return 0;
204 default:
205 pr_err("unsupported get_log_page lid %d\n",
206 cmd->get_log_page.lid);
207 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
208 }
209 case nvme_admin_identify:
210 req->data_len = NVME_IDENTIFY_DATA_SIZE;
211 switch (cmd->identify.cns) {
212 case NVME_ID_CNS_CTRL:
213 req->execute =
214 nvmet_execute_identify_disc_ctrl;
215 return 0;
216 default:
217 pr_err("unsupported identify cns %d\n",
218 cmd->identify.cns);
219 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
220 }
221 default:
222 pr_err("unsupported cmd %d\n", cmd->common.opcode);
223 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
224 }
225
226 pr_err("unhandled cmd %d\n", cmd->common.opcode);
227 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
228 }
229
nvmet_init_discovery(void)230 int __init nvmet_init_discovery(void)
231 {
232 nvmet_disc_subsys =
233 nvmet_subsys_alloc(NVME_DISC_SUBSYS_NAME, NVME_NQN_DISC);
234 if (!nvmet_disc_subsys)
235 return -ENOMEM;
236 return 0;
237 }
238
nvmet_exit_discovery(void)239 void nvmet_exit_discovery(void)
240 {
241 nvmet_subsys_put(nvmet_disc_subsys);
242 }
243
