drivers/nvme/target/discovery.c

   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
  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
  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
  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  */
  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
  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
 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
 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
 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
 239 void nvmet_exit_discovery(void)
 240 {
 241         nvmet_subsys_put(nvmet_disc_subsys);
 242 }