drivers/nvme/target/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
  11 struct nvmet_subsys *nvmet_disc_subsys;
  12
  13 static u64 nvmet_genctr;
  14
  15 static 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_TYPE_NOTICE,
  25                               NVME_AER_NOTICE_DISC_CHANGED, NVME_LOG_DISC);
  26 }
  27
  28 void 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
  50 static 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
  66 void 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
  83 void 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
  94 void 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
 105 static 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  */
 135 static 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
 144 static 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 = 0;
 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
 161 static 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
 175         if (!nvmet_check_transfer_len(req, data_len))
 176                 return;
 177
 178         if (req->cmd->get_log_page.lid != NVME_LOG_DISC) {
 179                 req->error_loc =
 180                         offsetof(struct nvme_get_log_page_command, lid);
 181                 status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 182                 goto out;
 183         }
 184
 185         /* Spec requires dword aligned offsets */
 186         if (offset & 0x3) {
 187                 req->error_loc =
 188                         offsetof(struct nvme_get_log_page_command, lpo);
 189                 status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 190                 goto out;
 191         }
 192
 193         /*
 194          * Make sure we're passing at least a buffer of response header size.
 195          * If host provided data len is less than the header size, only the
 196          * number of bytes requested by host will be sent to host.
 197          */
 198         down_read(&nvmet_config_sem);
 199         alloc_len = sizeof(*hdr) + entry_size * discovery_log_entries(req);
 200         buffer = kzalloc(alloc_len, GFP_KERNEL);
 201         if (!buffer) {
 202                 up_read(&nvmet_config_sem);
 203                 status = NVME_SC_INTERNAL;
 204                 goto out;
 205         }
 206
 207         hdr = buffer;
 208         list_for_each_entry(p, &req->port->subsystems, entry) {
 209                 char traddr[NVMF_TRADDR_SIZE];
 210
 211                 if (!nvmet_host_allowed(p->subsys, ctrl->hostnqn))
 212                         continue;
 213
 214                 nvmet_set_disc_traddr(req, req->port, traddr);
 215                 nvmet_format_discovery_entry(hdr, req->port,
 216                                 p->subsys->subsysnqn, traddr,
 217                                 NVME_NQN_NVME, numrec);
 218                 numrec++;
 219         }
 220
 221         list_for_each_entry(r, &req->port->referrals, entry) {
 222                 nvmet_format_discovery_entry(hdr, r,
 223                                 NVME_DISC_SUBSYS_NAME,
 224                                 r->disc_addr.traddr,
 225                                 NVME_NQN_DISC, numrec);
 226                 numrec++;
 227         }
 228
 229         hdr->genctr = cpu_to_le64(nvmet_genctr);
 230         hdr->numrec = cpu_to_le64(numrec);
 231         hdr->recfmt = cpu_to_le16(0);
 232
 233         nvmet_clear_aen_bit(req, NVME_AEN_BIT_DISC_CHANGE);
 234
 235         up_read(&nvmet_config_sem);
 236
 237         status = nvmet_copy_to_sgl(req, 0, buffer + offset, data_len);
 238         kfree(buffer);
 239 out:
 240         nvmet_req_complete(req, status);
 241 }
 242
 243 static void nvmet_execute_disc_identify(struct nvmet_req *req)
 244 {
 245         struct nvmet_ctrl *ctrl = req->sq->ctrl;
 246         struct nvme_id_ctrl *id;
 247         const char model[] = "Linux";
 248         u16 status = 0;
 249
 250         if (!nvmet_check_transfer_len(req, NVME_IDENTIFY_DATA_SIZE))
 251                 return;
 252
 253         if (req->cmd->identify.cns != NVME_ID_CNS_CTRL) {
 254                 req->error_loc = offsetof(struct nvme_identify, cns);
 255                 status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 256                 goto out;
 257         }
 258
 259         id = kzalloc(sizeof(*id), GFP_KERNEL);
 260         if (!id) {
 261                 status = NVME_SC_INTERNAL;
 262                 goto out;
 263         }
 264
 265         memset(id->sn, ' ', sizeof(id->sn));
 266         bin2hex(id->sn, &ctrl->subsys->serial,
 267                 min(sizeof(ctrl->subsys->serial), sizeof(id->sn) / 2));
 268         memset(id->fr, ' ', sizeof(id->fr));
 269         memcpy_and_pad(id->mn, sizeof(id->mn), model, sizeof(model) - 1, ' ');
 270         memcpy_and_pad(id->fr, sizeof(id->fr),
 271                        UTS_RELEASE, strlen(UTS_RELEASE), ' ');
 272
 273         /* no limit on data transfer sizes for now */
 274         id->mdts = 0;
 275         id->cntlid = cpu_to_le16(ctrl->cntlid);
 276         id->ver = cpu_to_le32(ctrl->subsys->ver);
 277         id->lpa = (1 << 2);
 278
 279         /* no enforcement soft-limit for maxcmd - pick arbitrary high value */
 280         id->maxcmd = cpu_to_le16(NVMET_MAX_CMD);
 281
 282         id->sgls = cpu_to_le32(1 << 0); /* we always support SGLs */
 283         if (ctrl->ops->flags & NVMF_KEYED_SGLS)
 284                 id->sgls |= cpu_to_le32(1 << 2);
 285         if (req->port->inline_data_size)
 286                 id->sgls |= cpu_to_le32(1 << 20);
 287
 288         id->oaes = cpu_to_le32(NVMET_DISC_AEN_CFG_OPTIONAL);
 289
 290         strlcpy(id->subnqn, ctrl->subsys->subsysnqn, sizeof(id->subnqn));
 291
 292         status = nvmet_copy_to_sgl(req, 0, id, sizeof(*id));
 293
 294         kfree(id);
 295 out:
 296         nvmet_req_complete(req, status);
 297 }
 298
 299 static void nvmet_execute_disc_set_features(struct nvmet_req *req)
 300 {
 301         u32 cdw10 = le32_to_cpu(req->cmd->common.cdw10);
 302         u16 stat;
 303
 304         if (!nvmet_check_transfer_len(req, 0))
 305                 return;
 306
 307         switch (cdw10 & 0xff) {
 308         case NVME_FEAT_KATO:
 309                 stat = nvmet_set_feat_kato(req);
 310                 break;
 311         case NVME_FEAT_ASYNC_EVENT:
 312                 stat = nvmet_set_feat_async_event(req,
 313                                                   NVMET_DISC_AEN_CFG_OPTIONAL);
 314                 break;
 315         default:
 316                 req->error_loc =
 317                         offsetof(struct nvme_common_command, cdw10);
 318                 stat = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 319                 break;
 320         }
 321
 322         nvmet_req_complete(req, stat);
 323 }
 324
 325 static void nvmet_execute_disc_get_features(struct nvmet_req *req)
 326 {
 327         u32 cdw10 = le32_to_cpu(req->cmd->common.cdw10);
 328         u16 stat = 0;
 329
 330         if (!nvmet_check_transfer_len(req, 0))
 331                 return;
 332
 333         switch (cdw10 & 0xff) {
 334         case NVME_FEAT_KATO:
 335                 nvmet_get_feat_kato(req);
 336                 break;
 337         case NVME_FEAT_ASYNC_EVENT:
 338                 nvmet_get_feat_async_event(req);
 339                 break;
 340         default:
 341                 req->error_loc =
 342                         offsetof(struct nvme_common_command, cdw10);
 343                 stat = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 344                 break;
 345         }
 346
 347         nvmet_req_complete(req, stat);
 348 }
 349
 350 u16 nvmet_parse_discovery_cmd(struct nvmet_req *req)
 351 {
 352         struct nvme_command *cmd = req->cmd;
 353
 354         if (unlikely(!(req->sq->ctrl->csts & NVME_CSTS_RDY))) {
 355                 pr_err("got cmd %d while not ready\n",
 356                        cmd->common.opcode);
 357                 req->error_loc =
 358                         offsetof(struct nvme_common_command, opcode);
 359                 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 360         }
 361
 362         switch (cmd->common.opcode) {
 363         case nvme_admin_set_features:
 364                 req->execute = nvmet_execute_disc_set_features;
 365                 return 0;
 366         case nvme_admin_get_features:
 367                 req->execute = nvmet_execute_disc_get_features;
 368                 return 0;
 369         case nvme_admin_async_event:
 370                 req->execute = nvmet_execute_async_event;
 371                 return 0;
 372         case nvme_admin_keep_alive:
 373                 req->execute = nvmet_execute_keep_alive;
 374                 return 0;
 375         case nvme_admin_get_log_page:
 376                 req->execute = nvmet_execute_disc_get_log_page;
 377                 return 0;
 378         case nvme_admin_identify:
 379                 req->execute = nvmet_execute_disc_identify;
 380                 return 0;
 381         default:
 382                 pr_err("unhandled cmd %d\n", cmd->common.opcode);
 383                 req->error_loc = offsetof(struct nvme_common_command, opcode);
 384                 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 385         }
 386
 387 }
 388
 389 int __init nvmet_init_discovery(void)
 390 {
 391         nvmet_disc_subsys =
 392                 nvmet_subsys_alloc(NVME_DISC_SUBSYS_NAME, NVME_NQN_DISC);
 393         return PTR_ERR_OR_ZERO(nvmet_disc_subsys);
 394 }
 395
 396 void nvmet_exit_discovery(void)
 397 {
 398         nvmet_subsys_put(nvmet_disc_subsys);
 399 }