drivers/nvme/target/tcp.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * NVMe over Fabrics TCP target.
   4  * Copyright (c) 2018 Lightbits Labs. All rights reserved.
   5  */
   6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   7 #include <linux/module.h>
   8 #include <linux/init.h>
   9 #include <linux/slab.h>
  10 #include <linux/err.h>
  11 #include <linux/nvme-tcp.h>
  12 #include <net/sock.h>
  13 #include <net/tcp.h>
  14 #include <linux/inet.h>
  15 #include <linux/llist.h>
  16 #include <crypto/hash.h>
  17
  18 #include "nvmet.h"
  19
  20 #define NVMET_TCP_DEF_INLINE_DATA_SIZE  (4 * PAGE_SIZE)
  21
  22 #define NVMET_TCP_RECV_BUDGET           8
  23 #define NVMET_TCP_SEND_BUDGET           8
  24 #define NVMET_TCP_IO_WORK_BUDGET        64
  25
  26 enum nvmet_tcp_send_state {
  27         NVMET_TCP_SEND_DATA_PDU,
  28         NVMET_TCP_SEND_DATA,
  29         NVMET_TCP_SEND_R2T,
  30         NVMET_TCP_SEND_DDGST,
  31         NVMET_TCP_SEND_RESPONSE
  32 };
  33
  34 enum nvmet_tcp_recv_state {
  35         NVMET_TCP_RECV_PDU,
  36         NVMET_TCP_RECV_DATA,
  37         NVMET_TCP_RECV_DDGST,
  38         NVMET_TCP_RECV_ERR,
  39 };
  40
  41 enum {
  42         NVMET_TCP_F_INIT_FAILED = (1 << 0),
  43 };
  44
  45 struct nvmet_tcp_cmd {
  46         struct nvmet_tcp_queue          *queue;
  47         struct nvmet_req                req;
  48
  49         struct nvme_tcp_cmd_pdu         *cmd_pdu;
  50         struct nvme_tcp_rsp_pdu         *rsp_pdu;
  51         struct nvme_tcp_data_pdu        *data_pdu;
  52         struct nvme_tcp_r2t_pdu         *r2t_pdu;
  53
  54         u32                             rbytes_done;
  55         u32                             wbytes_done;
  56
  57         u32                             pdu_len;
  58         u32                             pdu_recv;
  59         int                             sg_idx;
  60         int                             nr_mapped;
  61         struct msghdr                   recv_msg;
  62         struct kvec                     *iov;
  63         u32                             flags;
  64
  65         struct list_head                entry;
  66         struct llist_node               lentry;
  67
  68         /* send state */
  69         u32                             offset;
  70         struct scatterlist              *cur_sg;
  71         enum nvmet_tcp_send_state       state;
  72
  73         __le32                          exp_ddgst;
  74         __le32                          recv_ddgst;
  75 };
  76
  77 enum nvmet_tcp_queue_state {
  78         NVMET_TCP_Q_CONNECTING,
  79         NVMET_TCP_Q_LIVE,
  80         NVMET_TCP_Q_DISCONNECTING,
  81 };
  82
  83 struct nvmet_tcp_queue {
  84         struct socket           *sock;
  85         struct nvmet_tcp_port   *port;
  86         struct work_struct      io_work;
  87         int                     cpu;
  88         struct nvmet_cq         nvme_cq;
  89         struct nvmet_sq         nvme_sq;
  90
  91         /* send state */
  92         struct nvmet_tcp_cmd    *cmds;
  93         unsigned int            nr_cmds;
  94         struct list_head        free_list;
  95         struct llist_head       resp_list;
  96         struct list_head        resp_send_list;
  97         int                     send_list_len;
  98         struct nvmet_tcp_cmd    *snd_cmd;
  99
 100         /* recv state */
 101         int                     offset;
 102         int                     left;
 103         enum nvmet_tcp_recv_state rcv_state;
 104         struct nvmet_tcp_cmd    *cmd;
 105         union nvme_tcp_pdu      pdu;
 106
 107         /* digest state */
 108         bool                    hdr_digest;
 109         bool                    data_digest;
 110         struct ahash_request    *snd_hash;
 111         struct ahash_request    *rcv_hash;
 112
 113         spinlock_t              state_lock;
 114         enum nvmet_tcp_queue_state state;
 115
 116         struct sockaddr_storage sockaddr;
 117         struct sockaddr_storage sockaddr_peer;
 118         struct work_struct      release_work;
 119
 120         int                     idx;
 121         struct list_head        queue_list;
 122
 123         struct nvmet_tcp_cmd    connect;
 124
 125         struct page_frag_cache  pf_cache;
 126
 127         void (*data_ready)(struct sock *);
 128         void (*state_change)(struct sock *);
 129         void (*write_space)(struct sock *);
 130 };
 131
 132 struct nvmet_tcp_port {
 133         struct socket           *sock;
 134         struct work_struct      accept_work;
 135         struct nvmet_port       *nport;
 136         struct sockaddr_storage addr;
 137         int                     last_cpu;
 138         void (*data_ready)(struct sock *);
 139 };
 140
 141 static DEFINE_IDA(nvmet_tcp_queue_ida);
 142 static LIST_HEAD(nvmet_tcp_queue_list);
 143 static DEFINE_MUTEX(nvmet_tcp_queue_mutex);
 144
 145 static struct workqueue_struct *nvmet_tcp_wq;
 146 static struct nvmet_fabrics_ops nvmet_tcp_ops;
 147 static void nvmet_tcp_free_cmd(struct nvmet_tcp_cmd *c);
 148 static void nvmet_tcp_finish_cmd(struct nvmet_tcp_cmd *cmd);
 149
 150 static inline u16 nvmet_tcp_cmd_tag(struct nvmet_tcp_queue *queue,
 151                 struct nvmet_tcp_cmd *cmd)
 152 {
 153         return cmd - queue->cmds;
 154 }
 155
 156 static inline bool nvmet_tcp_has_data_in(struct nvmet_tcp_cmd *cmd)
 157 {
 158         return nvme_is_write(cmd->req.cmd) &&
 159                 cmd->rbytes_done < cmd->req.transfer_len;
 160 }
 161
 162 static inline bool nvmet_tcp_need_data_in(struct nvmet_tcp_cmd *cmd)
 163 {
 164         return nvmet_tcp_has_data_in(cmd) && !cmd->req.cqe->status;
 165 }
 166
 167 static inline bool nvmet_tcp_need_data_out(struct nvmet_tcp_cmd *cmd)
 168 {
 169         return !nvme_is_write(cmd->req.cmd) &&
 170                 cmd->req.transfer_len > 0 &&
 171                 !cmd->req.cqe->status;
 172 }
 173
 174 static inline bool nvmet_tcp_has_inline_data(struct nvmet_tcp_cmd *cmd)
 175 {
 176         return nvme_is_write(cmd->req.cmd) && cmd->pdu_len &&
 177                 !cmd->rbytes_done;
 178 }
 179
 180 static inline struct nvmet_tcp_cmd *
 181 nvmet_tcp_get_cmd(struct nvmet_tcp_queue *queue)
 182 {
 183         struct nvmet_tcp_cmd *cmd;
 184
 185         cmd = list_first_entry_or_null(&queue->free_list,
 186                                 struct nvmet_tcp_cmd, entry);
 187         if (!cmd)
 188                 return NULL;
 189         list_del_init(&cmd->entry);
 190
 191         cmd->rbytes_done = cmd->wbytes_done = 0;
 192         cmd->pdu_len = 0;
 193         cmd->pdu_recv = 0;
 194         cmd->iov = NULL;
 195         cmd->flags = 0;
 196         return cmd;
 197 }
 198
 199 static inline void nvmet_tcp_put_cmd(struct nvmet_tcp_cmd *cmd)
 200 {
 201         if (unlikely(cmd == &cmd->queue->connect))
 202                 return;
 203
 204         list_add_tail(&cmd->entry, &cmd->queue->free_list);
 205 }
 206
 207 static inline u8 nvmet_tcp_hdgst_len(struct nvmet_tcp_queue *queue)
 208 {
 209         return queue->hdr_digest ? NVME_TCP_DIGEST_LENGTH : 0;
 210 }
 211
 212 static inline u8 nvmet_tcp_ddgst_len(struct nvmet_tcp_queue *queue)
 213 {
 214         return queue->data_digest ? NVME_TCP_DIGEST_LENGTH : 0;
 215 }
 216
 217 static inline void nvmet_tcp_hdgst(struct ahash_request *hash,
 218                 void *pdu, size_t len)
 219 {
 220         struct scatterlist sg;
 221
 222         sg_init_one(&sg, pdu, len);
 223         ahash_request_set_crypt(hash, &sg, pdu + len, len);
 224         crypto_ahash_digest(hash);
 225 }
 226
 227 static int nvmet_tcp_verify_hdgst(struct nvmet_tcp_queue *queue,
 228         void *pdu, size_t len)
 229 {
 230         struct nvme_tcp_hdr *hdr = pdu;
 231         __le32 recv_digest;
 232         __le32 exp_digest;
 233
 234         if (unlikely(!(hdr->flags & NVME_TCP_F_HDGST))) {
 235                 pr_err("queue %d: header digest enabled but no header digest\n",
 236                         queue->idx);
 237                 return -EPROTO;
 238         }
 239
 240         recv_digest = *(__le32 *)(pdu + hdr->hlen);
 241         nvmet_tcp_hdgst(queue->rcv_hash, pdu, len);
 242         exp_digest = *(__le32 *)(pdu + hdr->hlen);
 243         if (recv_digest != exp_digest) {
 244                 pr_err("queue %d: header digest error: recv %#x expected %#x\n",
 245                         queue->idx, le32_to_cpu(recv_digest),
 246                         le32_to_cpu(exp_digest));
 247                 return -EPROTO;
 248         }
 249
 250         return 0;
 251 }
 252
 253 static int nvmet_tcp_check_ddgst(struct nvmet_tcp_queue *queue, void *pdu)
 254 {
 255         struct nvme_tcp_hdr *hdr = pdu;
 256         u8 digest_len = nvmet_tcp_hdgst_len(queue);
 257         u32 len;
 258
 259         len = le32_to_cpu(hdr->plen) - hdr->hlen -
 260                 (hdr->flags & NVME_TCP_F_HDGST ? digest_len : 0);
 261
 262         if (unlikely(len && !(hdr->flags & NVME_TCP_F_DDGST))) {
 263                 pr_err("queue %d: data digest flag is cleared\n", queue->idx);
 264                 return -EPROTO;
 265         }
 266
 267         return 0;
 268 }
 269
 270 static void nvmet_tcp_unmap_pdu_iovec(struct nvmet_tcp_cmd *cmd)
 271 {
 272         struct scatterlist *sg;
 273         int i;
 274
 275         sg = &cmd->req.sg[cmd->sg_idx];
 276
 277         for (i = 0; i < cmd->nr_mapped; i++)
 278                 kunmap(sg_page(&sg[i]));
 279 }
 280
 281 static void nvmet_tcp_map_pdu_iovec(struct nvmet_tcp_cmd *cmd)
 282 {
 283         struct kvec *iov = cmd->iov;
 284         struct scatterlist *sg;
 285         u32 length, offset, sg_offset;
 286
 287         length = cmd->pdu_len;
 288         cmd->nr_mapped = DIV_ROUND_UP(length, PAGE_SIZE);
 289         offset = cmd->rbytes_done;
 290         cmd->sg_idx = DIV_ROUND_UP(offset, PAGE_SIZE);
 291         sg_offset = offset % PAGE_SIZE;
 292         sg = &cmd->req.sg[cmd->sg_idx];
 293
 294         while (length) {
 295                 u32 iov_len = min_t(u32, length, sg->length - sg_offset);
 296
 297                 iov->iov_base = kmap(sg_page(sg)) + sg->offset + sg_offset;
 298                 iov->iov_len = iov_len;
 299
 300                 length -= iov_len;
 301                 sg = sg_next(sg);
 302                 iov++;
 303         }
 304
 305         iov_iter_kvec(&cmd->recv_msg.msg_iter, READ, cmd->iov,
 306                 cmd->nr_mapped, cmd->pdu_len);
 307 }
 308
 309 static void nvmet_tcp_fatal_error(struct nvmet_tcp_queue *queue)
 310 {
 311         queue->rcv_state = NVMET_TCP_RECV_ERR;
 312         if (queue->nvme_sq.ctrl)
 313                 nvmet_ctrl_fatal_error(queue->nvme_sq.ctrl);
 314         else
 315                 kernel_sock_shutdown(queue->sock, SHUT_RDWR);
 316 }
 317
 318 static int nvmet_tcp_map_data(struct nvmet_tcp_cmd *cmd)
 319 {
 320         struct nvme_sgl_desc *sgl = &cmd->req.cmd->common.dptr.sgl;
 321         u32 len = le32_to_cpu(sgl->length);
 322
 323         if (!cmd->req.data_len)
 324                 return 0;
 325
 326         if (sgl->type == ((NVME_SGL_FMT_DATA_DESC << 4) |
 327                           NVME_SGL_FMT_OFFSET)) {
 328                 if (!nvme_is_write(cmd->req.cmd))
 329                         return NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 330
 331                 if (len > cmd->req.port->inline_data_size)
 332                         return NVME_SC_SGL_INVALID_OFFSET | NVME_SC_DNR;
 333                 cmd->pdu_len = len;
 334         }
 335         cmd->req.transfer_len += len;
 336
 337         cmd->req.sg = sgl_alloc(len, GFP_KERNEL, &cmd->req.sg_cnt);
 338         if (!cmd->req.sg)
 339                 return NVME_SC_INTERNAL;
 340         cmd->cur_sg = cmd->req.sg;
 341
 342         if (nvmet_tcp_has_data_in(cmd)) {
 343                 cmd->iov = kmalloc_array(cmd->req.sg_cnt,
 344                                 sizeof(*cmd->iov), GFP_KERNEL);
 345                 if (!cmd->iov)
 346                         goto err;
 347         }
 348
 349         return 0;
 350 err:
 351         sgl_free(cmd->req.sg);
 352         return NVME_SC_INTERNAL;
 353 }
 354
 355 static void nvmet_tcp_ddgst(struct ahash_request *hash,
 356                 struct nvmet_tcp_cmd *cmd)
 357 {
 358         ahash_request_set_crypt(hash, cmd->req.sg,
 359                 (void *)&cmd->exp_ddgst, cmd->req.transfer_len);
 360         crypto_ahash_digest(hash);
 361 }
 362
 363 static void nvmet_setup_c2h_data_pdu(struct nvmet_tcp_cmd *cmd)
 364 {
 365         struct nvme_tcp_data_pdu *pdu = cmd->data_pdu;
 366         struct nvmet_tcp_queue *queue = cmd->queue;
 367         u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
 368         u8 ddgst = nvmet_tcp_ddgst_len(cmd->queue);
 369
 370         cmd->offset = 0;
 371         cmd->state = NVMET_TCP_SEND_DATA_PDU;
 372
 373         pdu->hdr.type = nvme_tcp_c2h_data;
 374         pdu->hdr.flags = NVME_TCP_F_DATA_LAST | (queue->nvme_sq.sqhd_disabled ?
 375                                                 NVME_TCP_F_DATA_SUCCESS : 0);
 376         pdu->hdr.hlen = sizeof(*pdu);
 377         pdu->hdr.pdo = pdu->hdr.hlen + hdgst;
 378         pdu->hdr.plen =
 379                 cpu_to_le32(pdu->hdr.hlen + hdgst +
 380                                 cmd->req.transfer_len + ddgst);
 381         pdu->command_id = cmd->req.cqe->command_id;
 382         pdu->data_length = cpu_to_le32(cmd->req.transfer_len);
 383         pdu->data_offset = cpu_to_le32(cmd->wbytes_done);
 384
 385         if (queue->data_digest) {
 386                 pdu->hdr.flags |= NVME_TCP_F_DDGST;
 387                 nvmet_tcp_ddgst(queue->snd_hash, cmd);
 388         }
 389
 390         if (cmd->queue->hdr_digest) {
 391                 pdu->hdr.flags |= NVME_TCP_F_HDGST;
 392                 nvmet_tcp_hdgst(queue->snd_hash, pdu, sizeof(*pdu));
 393         }
 394 }
 395
 396 static void nvmet_setup_r2t_pdu(struct nvmet_tcp_cmd *cmd)
 397 {
 398         struct nvme_tcp_r2t_pdu *pdu = cmd->r2t_pdu;
 399         struct nvmet_tcp_queue *queue = cmd->queue;
 400         u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
 401
 402         cmd->offset = 0;
 403         cmd->state = NVMET_TCP_SEND_R2T;
 404
 405         pdu->hdr.type = nvme_tcp_r2t;
 406         pdu->hdr.flags = 0;
 407         pdu->hdr.hlen = sizeof(*pdu);
 408         pdu->hdr.pdo = 0;
 409         pdu->hdr.plen = cpu_to_le32(pdu->hdr.hlen + hdgst);
 410
 411         pdu->command_id = cmd->req.cmd->common.command_id;
 412         pdu->ttag = nvmet_tcp_cmd_tag(cmd->queue, cmd);
 413         pdu->r2t_length = cpu_to_le32(cmd->req.transfer_len - cmd->rbytes_done);
 414         pdu->r2t_offset = cpu_to_le32(cmd->rbytes_done);
 415         if (cmd->queue->hdr_digest) {
 416                 pdu->hdr.flags |= NVME_TCP_F_HDGST;
 417                 nvmet_tcp_hdgst(queue->snd_hash, pdu, sizeof(*pdu));
 418         }
 419 }
 420
 421 static void nvmet_setup_response_pdu(struct nvmet_tcp_cmd *cmd)
 422 {
 423         struct nvme_tcp_rsp_pdu *pdu = cmd->rsp_pdu;
 424         struct nvmet_tcp_queue *queue = cmd->queue;
 425         u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
 426
 427         cmd->offset = 0;
 428         cmd->state = NVMET_TCP_SEND_RESPONSE;
 429
 430         pdu->hdr.type = nvme_tcp_rsp;
 431         pdu->hdr.flags = 0;
 432         pdu->hdr.hlen = sizeof(*pdu);
 433         pdu->hdr.pdo = 0;
 434         pdu->hdr.plen = cpu_to_le32(pdu->hdr.hlen + hdgst);
 435         if (cmd->queue->hdr_digest) {
 436                 pdu->hdr.flags |= NVME_TCP_F_HDGST;
 437                 nvmet_tcp_hdgst(queue->snd_hash, pdu, sizeof(*pdu));
 438         }
 439 }
 440
 441 static void nvmet_tcp_process_resp_list(struct nvmet_tcp_queue *queue)
 442 {
 443         struct llist_node *node;
 444
 445         node = llist_del_all(&queue->resp_list);
 446         if (!node)
 447                 return;
 448
 449         while (node) {
 450                 struct nvmet_tcp_cmd *cmd = llist_entry(node,
 451                                         struct nvmet_tcp_cmd, lentry);
 452
 453                 list_add(&cmd->entry, &queue->resp_send_list);
 454                 node = node->next;
 455                 queue->send_list_len++;
 456         }
 457 }
 458
 459 static struct nvmet_tcp_cmd *nvmet_tcp_fetch_cmd(struct nvmet_tcp_queue *queue)
 460 {
 461         queue->snd_cmd = list_first_entry_or_null(&queue->resp_send_list,
 462                                 struct nvmet_tcp_cmd, entry);
 463         if (!queue->snd_cmd) {
 464                 nvmet_tcp_process_resp_list(queue);
 465                 queue->snd_cmd =
 466                         list_first_entry_or_null(&queue->resp_send_list,
 467                                         struct nvmet_tcp_cmd, entry);
 468                 if (unlikely(!queue->snd_cmd))
 469                         return NULL;
 470         }
 471
 472         list_del_init(&queue->snd_cmd->entry);
 473         queue->send_list_len--;
 474
 475         if (nvmet_tcp_need_data_out(queue->snd_cmd))
 476                 nvmet_setup_c2h_data_pdu(queue->snd_cmd);
 477         else if (nvmet_tcp_need_data_in(queue->snd_cmd))
 478                 nvmet_setup_r2t_pdu(queue->snd_cmd);
 479         else
 480                 nvmet_setup_response_pdu(queue->snd_cmd);
 481
 482         return queue->snd_cmd;
 483 }
 484
 485 static void nvmet_tcp_queue_response(struct nvmet_req *req)
 486 {
 487         struct nvmet_tcp_cmd *cmd =
 488                 container_of(req, struct nvmet_tcp_cmd, req);
 489         struct nvmet_tcp_queue  *queue = cmd->queue;
 490
 491         llist_add(&cmd->lentry, &queue->resp_list);
 492         queue_work_on(cmd->queue->cpu, nvmet_tcp_wq, &cmd->queue->io_work);
 493 }
 494
 495 static int nvmet_try_send_data_pdu(struct nvmet_tcp_cmd *cmd)
 496 {
 497         u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
 498         int left = sizeof(*cmd->data_pdu) - cmd->offset + hdgst;
 499         int ret;
 500
 501         ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->data_pdu),
 502                         offset_in_page(cmd->data_pdu) + cmd->offset,
 503                         left, MSG_DONTWAIT | MSG_MORE);
 504         if (ret <= 0)
 505                 return ret;
 506
 507         cmd->offset += ret;
 508         left -= ret;
 509
 510         if (left)
 511                 return -EAGAIN;
 512
 513         cmd->state = NVMET_TCP_SEND_DATA;
 514         cmd->offset  = 0;
 515         return 1;
 516 }
 517
 518 static int nvmet_try_send_data(struct nvmet_tcp_cmd *cmd)
 519 {
 520         struct nvmet_tcp_queue *queue = cmd->queue;
 521         int ret;
 522
 523         while (cmd->cur_sg) {
 524                 struct page *page = sg_page(cmd->cur_sg);
 525                 u32 left = cmd->cur_sg->length - cmd->offset;
 526
 527                 ret = kernel_sendpage(cmd->queue->sock, page, cmd->offset,
 528                                         left, MSG_DONTWAIT | MSG_MORE);
 529                 if (ret <= 0)
 530                         return ret;
 531
 532                 cmd->offset += ret;
 533                 cmd->wbytes_done += ret;
 534
 535                 /* Done with sg?*/
 536                 if (cmd->offset == cmd->cur_sg->length) {
 537                         cmd->cur_sg = sg_next(cmd->cur_sg);
 538                         cmd->offset = 0;
 539                 }
 540         }
 541
 542         if (queue->data_digest) {
 543                 cmd->state = NVMET_TCP_SEND_DDGST;
 544                 cmd->offset = 0;
 545         } else {
 546                 if (queue->nvme_sq.sqhd_disabled) {
 547                         cmd->queue->snd_cmd = NULL;
 548                         nvmet_tcp_put_cmd(cmd);
 549                 } else {
 550                         nvmet_setup_response_pdu(cmd);
 551                 }
 552         }
 553
 554         if (queue->nvme_sq.sqhd_disabled) {
 555                 kfree(cmd->iov);
 556                 sgl_free(cmd->req.sg);
 557         }
 558
 559         return 1;
 560
 561 }
 562
 563 static int nvmet_try_send_response(struct nvmet_tcp_cmd *cmd,
 564                 bool last_in_batch)
 565 {
 566         u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
 567         int left = sizeof(*cmd->rsp_pdu) - cmd->offset + hdgst;
 568         int flags = MSG_DONTWAIT;
 569         int ret;
 570
 571         if (!last_in_batch && cmd->queue->send_list_len)
 572                 flags |= MSG_MORE;
 573         else
 574                 flags |= MSG_EOR;
 575
 576         ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->rsp_pdu),
 577                 offset_in_page(cmd->rsp_pdu) + cmd->offset, left, flags);
 578         if (ret <= 0)
 579                 return ret;
 580         cmd->offset += ret;
 581         left -= ret;
 582
 583         if (left)
 584                 return -EAGAIN;
 585
 586         kfree(cmd->iov);
 587         sgl_free(cmd->req.sg);
 588         cmd->queue->snd_cmd = NULL;
 589         nvmet_tcp_put_cmd(cmd);
 590         return 1;
 591 }
 592
 593 static int nvmet_try_send_r2t(struct nvmet_tcp_cmd *cmd, bool last_in_batch)
 594 {
 595         u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
 596         int left = sizeof(*cmd->r2t_pdu) - cmd->offset + hdgst;
 597         int flags = MSG_DONTWAIT;
 598         int ret;
 599
 600         if (!last_in_batch && cmd->queue->send_list_len)
 601                 flags |= MSG_MORE;
 602         else
 603                 flags |= MSG_EOR;
 604
 605         ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->r2t_pdu),
 606                 offset_in_page(cmd->r2t_pdu) + cmd->offset, left, flags);
 607         if (ret <= 0)
 608                 return ret;
 609         cmd->offset += ret;
 610         left -= ret;
 611
 612         if (left)
 613                 return -EAGAIN;
 614
 615         cmd->queue->snd_cmd = NULL;
 616         return 1;
 617 }
 618
 619 static int nvmet_try_send_ddgst(struct nvmet_tcp_cmd *cmd)
 620 {
 621         struct nvmet_tcp_queue *queue = cmd->queue;
 622         struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
 623         struct kvec iov = {
 624                 .iov_base = &cmd->exp_ddgst + cmd->offset,
 625                 .iov_len = NVME_TCP_DIGEST_LENGTH - cmd->offset
 626         };
 627         int ret;
 628
 629         ret = kernel_sendmsg(queue->sock, &msg, &iov, 1, iov.iov_len);
 630         if (unlikely(ret <= 0))
 631                 return ret;
 632
 633         cmd->offset += ret;
 634
 635         if (queue->nvme_sq.sqhd_disabled) {
 636                 cmd->queue->snd_cmd = NULL;
 637                 nvmet_tcp_put_cmd(cmd);
 638         } else {
 639                 nvmet_setup_response_pdu(cmd);
 640         }
 641         return 1;
 642 }
 643
 644 static int nvmet_tcp_try_send_one(struct nvmet_tcp_queue *queue,
 645                 bool last_in_batch)
 646 {
 647         struct nvmet_tcp_cmd *cmd = queue->snd_cmd;
 648         int ret = 0;
 649
 650         if (!cmd || queue->state == NVMET_TCP_Q_DISCONNECTING) {
 651                 cmd = nvmet_tcp_fetch_cmd(queue);
 652                 if (unlikely(!cmd))
 653                         return 0;
 654         }
 655
 656         if (cmd->state == NVMET_TCP_SEND_DATA_PDU) {
 657                 ret = nvmet_try_send_data_pdu(cmd);
 658                 if (ret <= 0)
 659                         goto done_send;
 660         }
 661
 662         if (cmd->state == NVMET_TCP_SEND_DATA) {
 663                 ret = nvmet_try_send_data(cmd);
 664                 if (ret <= 0)
 665                         goto done_send;
 666         }
 667
 668         if (cmd->state == NVMET_TCP_SEND_DDGST) {
 669                 ret = nvmet_try_send_ddgst(cmd);
 670                 if (ret <= 0)
 671                         goto done_send;
 672         }
 673
 674         if (cmd->state == NVMET_TCP_SEND_R2T) {
 675                 ret = nvmet_try_send_r2t(cmd, last_in_batch);
 676                 if (ret <= 0)
 677                         goto done_send;
 678         }
 679
 680         if (cmd->state == NVMET_TCP_SEND_RESPONSE)
 681                 ret = nvmet_try_send_response(cmd, last_in_batch);
 682
 683 done_send:
 684         if (ret < 0) {
 685                 if (ret == -EAGAIN)
 686                         return 0;
 687                 return ret;
 688         }
 689
 690         return 1;
 691 }
 692
 693 static int nvmet_tcp_try_send(struct nvmet_tcp_queue *queue,
 694                 int budget, int *sends)
 695 {
 696         int i, ret = 0;
 697
 698         for (i = 0; i < budget; i++) {
 699                 ret = nvmet_tcp_try_send_one(queue, i == budget - 1);
 700                 if (ret <= 0)
 701                         break;
 702                 (*sends)++;
 703         }
 704
 705         return ret;
 706 }
 707
 708 static void nvmet_prepare_receive_pdu(struct nvmet_tcp_queue *queue)
 709 {
 710         queue->offset = 0;
 711         queue->left = sizeof(struct nvme_tcp_hdr);
 712         queue->cmd = NULL;
 713         queue->rcv_state = NVMET_TCP_RECV_PDU;
 714 }
 715
 716 static void nvmet_tcp_free_crypto(struct nvmet_tcp_queue *queue)
 717 {
 718         struct crypto_ahash *tfm = crypto_ahash_reqtfm(queue->rcv_hash);
 719
 720         ahash_request_free(queue->rcv_hash);
 721         ahash_request_free(queue->snd_hash);
 722         crypto_free_ahash(tfm);
 723 }
 724
 725 static int nvmet_tcp_alloc_crypto(struct nvmet_tcp_queue *queue)
 726 {
 727         struct crypto_ahash *tfm;
 728
 729         tfm = crypto_alloc_ahash("crc32c", 0, CRYPTO_ALG_ASYNC);
 730         if (IS_ERR(tfm))
 731                 return PTR_ERR(tfm);
 732
 733         queue->snd_hash = ahash_request_alloc(tfm, GFP_KERNEL);
 734         if (!queue->snd_hash)
 735                 goto free_tfm;
 736         ahash_request_set_callback(queue->snd_hash, 0, NULL, NULL);
 737
 738         queue->rcv_hash = ahash_request_alloc(tfm, GFP_KERNEL);
 739         if (!queue->rcv_hash)
 740                 goto free_snd_hash;
 741         ahash_request_set_callback(queue->rcv_hash, 0, NULL, NULL);
 742
 743         return 0;
 744 free_snd_hash:
 745         ahash_request_free(queue->snd_hash);
 746 free_tfm:
 747         crypto_free_ahash(tfm);
 748         return -ENOMEM;
 749 }
 750
 751
 752 static int nvmet_tcp_handle_icreq(struct nvmet_tcp_queue *queue)
 753 {
 754         struct nvme_tcp_icreq_pdu *icreq = &queue->pdu.icreq;
 755         struct nvme_tcp_icresp_pdu *icresp = &queue->pdu.icresp;
 756         struct msghdr msg = {};
 757         struct kvec iov;
 758         int ret;
 759
 760         if (le32_to_cpu(icreq->hdr.plen) != sizeof(struct nvme_tcp_icreq_pdu)) {
 761                 pr_err("bad nvme-tcp pdu length (%d)\n",
 762                         le32_to_cpu(icreq->hdr.plen));
 763                 nvmet_tcp_fatal_error(queue);
 764         }
 765
 766         if (icreq->pfv != NVME_TCP_PFV_1_0) {
 767                 pr_err("queue %d: bad pfv %d\n", queue->idx, icreq->pfv);
 768                 return -EPROTO;
 769         }
 770
 771         if (icreq->hpda != 0) {
 772                 pr_err("queue %d: unsupported hpda %d\n", queue->idx,
 773                         icreq->hpda);
 774                 return -EPROTO;
 775         }
 776
 777         queue->hdr_digest = !!(icreq->digest & NVME_TCP_HDR_DIGEST_ENABLE);
 778         queue->data_digest = !!(icreq->digest & NVME_TCP_DATA_DIGEST_ENABLE);
 779         if (queue->hdr_digest || queue->data_digest) {
 780                 ret = nvmet_tcp_alloc_crypto(queue);
 781                 if (ret)
 782                         return ret;
 783         }
 784
 785         memset(icresp, 0, sizeof(*icresp));
 786         icresp->hdr.type = nvme_tcp_icresp;
 787         icresp->hdr.hlen = sizeof(*icresp);
 788         icresp->hdr.pdo = 0;
 789         icresp->hdr.plen = cpu_to_le32(icresp->hdr.hlen);
 790         icresp->pfv = cpu_to_le16(NVME_TCP_PFV_1_0);
 791         icresp->maxdata = cpu_to_le32(0xffff); /* FIXME: support r2t */
 792         icresp->cpda = 0;
 793         if (queue->hdr_digest)
 794                 icresp->digest |= NVME_TCP_HDR_DIGEST_ENABLE;
 795         if (queue->data_digest)
 796                 icresp->digest |= NVME_TCP_DATA_DIGEST_ENABLE;
 797
 798         iov.iov_base = icresp;
 799         iov.iov_len = sizeof(*icresp);
 800         ret = kernel_sendmsg(queue->sock, &msg, &iov, 1, iov.iov_len);
 801         if (ret < 0)
 802                 goto free_crypto;
 803
 804         queue->state = NVMET_TCP_Q_LIVE;
 805         nvmet_prepare_receive_pdu(queue);
 806         return 0;
 807 free_crypto:
 808         if (queue->hdr_digest || queue->data_digest)
 809                 nvmet_tcp_free_crypto(queue);
 810         return ret;
 811 }
 812
 813 static void nvmet_tcp_handle_req_failure(struct nvmet_tcp_queue *queue,
 814                 struct nvmet_tcp_cmd *cmd, struct nvmet_req *req)
 815 {
 816         int ret;
 817
 818         /* recover the expected data transfer length */
 819         req->data_len = le32_to_cpu(req->cmd->common.dptr.sgl.length);
 820
 821         if (!nvme_is_write(cmd->req.cmd) ||
 822             req->data_len > cmd->req.port->inline_data_size) {
 823                 nvmet_prepare_receive_pdu(queue);
 824                 return;
 825         }
 826
 827         ret = nvmet_tcp_map_data(cmd);
 828         if (unlikely(ret)) {
 829                 pr_err("queue %d: failed to map data\n", queue->idx);
 830                 nvmet_tcp_fatal_error(queue);
 831                 return;
 832         }
 833
 834         queue->rcv_state = NVMET_TCP_RECV_DATA;
 835         nvmet_tcp_map_pdu_iovec(cmd);
 836         cmd->flags |= NVMET_TCP_F_INIT_FAILED;
 837 }
 838
 839 static int nvmet_tcp_handle_h2c_data_pdu(struct nvmet_tcp_queue *queue)
 840 {
 841         struct nvme_tcp_data_pdu *data = &queue->pdu.data;
 842         struct nvmet_tcp_cmd *cmd;
 843
 844         cmd = &queue->cmds[data->ttag];
 845
 846         if (le32_to_cpu(data->data_offset) != cmd->rbytes_done) {
 847                 pr_err("ttag %u unexpected data offset %u (expected %u)\n",
 848                         data->ttag, le32_to_cpu(data->data_offset),
 849                         cmd->rbytes_done);
 850                 /* FIXME: use path and transport errors */
 851                 nvmet_req_complete(&cmd->req,
 852                         NVME_SC_INVALID_FIELD | NVME_SC_DNR);
 853                 return -EPROTO;
 854         }
 855
 856         cmd->pdu_len = le32_to_cpu(data->data_length);
 857         cmd->pdu_recv = 0;
 858         nvmet_tcp_map_pdu_iovec(cmd);
 859         queue->cmd = cmd;
 860         queue->rcv_state = NVMET_TCP_RECV_DATA;
 861
 862         return 0;
 863 }
 864
 865 static int nvmet_tcp_done_recv_pdu(struct nvmet_tcp_queue *queue)
 866 {
 867         struct nvme_tcp_hdr *hdr = &queue->pdu.cmd.hdr;
 868         struct nvme_command *nvme_cmd = &queue->pdu.cmd.cmd;
 869         struct nvmet_req *req;
 870         int ret;
 871
 872         if (unlikely(queue->state == NVMET_TCP_Q_CONNECTING)) {
 873                 if (hdr->type != nvme_tcp_icreq) {
 874                         pr_err("unexpected pdu type (%d) before icreq\n",
 875                                 hdr->type);
 876                         nvmet_tcp_fatal_error(queue);
 877                         return -EPROTO;
 878                 }
 879                 return nvmet_tcp_handle_icreq(queue);
 880         }
 881
 882         if (hdr->type == nvme_tcp_h2c_data) {
 883                 ret = nvmet_tcp_handle_h2c_data_pdu(queue);
 884                 if (unlikely(ret))
 885                         return ret;
 886                 return 0;
 887         }
 888
 889         queue->cmd = nvmet_tcp_get_cmd(queue);
 890         if (unlikely(!queue->cmd)) {
 891                 /* This should never happen */
 892                 pr_err("queue %d: out of commands (%d) send_list_len: %d, opcode: %d",
 893                         queue->idx, queue->nr_cmds, queue->send_list_len,
 894                         nvme_cmd->common.opcode);
 895                 nvmet_tcp_fatal_error(queue);
 896                 return -ENOMEM;
 897         }
 898
 899         req = &queue->cmd->req;
 900         memcpy(req->cmd, nvme_cmd, sizeof(*nvme_cmd));
 901
 902         if (unlikely(!nvmet_req_init(req, &queue->nvme_cq,
 903                         &queue->nvme_sq, &nvmet_tcp_ops))) {
 904                 pr_err("failed cmd %p id %d opcode %d, data_len: %d\n",
 905                         req->cmd, req->cmd->common.command_id,
 906                         req->cmd->common.opcode,
 907                         le32_to_cpu(req->cmd->common.dptr.sgl.length));
 908
 909                 nvmet_tcp_handle_req_failure(queue, queue->cmd, req);
 910                 return -EAGAIN;
 911         }
 912
 913         ret = nvmet_tcp_map_data(queue->cmd);
 914         if (unlikely(ret)) {
 915                 pr_err("queue %d: failed to map data\n", queue->idx);
 916                 if (nvmet_tcp_has_inline_data(queue->cmd))
 917                         nvmet_tcp_fatal_error(queue);
 918                 else
 919                         nvmet_req_complete(req, ret);
 920                 ret = -EAGAIN;
 921                 goto out;
 922         }
 923
 924         if (nvmet_tcp_need_data_in(queue->cmd)) {
 925                 if (nvmet_tcp_has_inline_data(queue->cmd)) {
 926                         queue->rcv_state = NVMET_TCP_RECV_DATA;
 927                         nvmet_tcp_map_pdu_iovec(queue->cmd);
 928                         return 0;
 929                 }
 930                 /* send back R2T */
 931                 nvmet_tcp_queue_response(&queue->cmd->req);
 932                 goto out;
 933         }
 934
 935         nvmet_req_execute(&queue->cmd->req);
 936 out:
 937         nvmet_prepare_receive_pdu(queue);
 938         return ret;
 939 }
 940
 941 static const u8 nvme_tcp_pdu_sizes[] = {
 942         [nvme_tcp_icreq]        = sizeof(struct nvme_tcp_icreq_pdu),
 943         [nvme_tcp_cmd]          = sizeof(struct nvme_tcp_cmd_pdu),
 944         [nvme_tcp_h2c_data]     = sizeof(struct nvme_tcp_data_pdu),
 945 };
 946
 947 static inline u8 nvmet_tcp_pdu_size(u8 type)
 948 {
 949         size_t idx = type;
 950
 951         return (idx < ARRAY_SIZE(nvme_tcp_pdu_sizes) &&
 952                 nvme_tcp_pdu_sizes[idx]) ?
 953                         nvme_tcp_pdu_sizes[idx] : 0;
 954 }
 955
 956 static inline bool nvmet_tcp_pdu_valid(u8 type)
 957 {
 958         switch (type) {
 959         case nvme_tcp_icreq:
 960         case nvme_tcp_cmd:
 961         case nvme_tcp_h2c_data:
 962                 /* fallthru */
 963                 return true;
 964         }
 965
 966         return false;
 967 }
 968
 969 static int nvmet_tcp_try_recv_pdu(struct nvmet_tcp_queue *queue)
 970 {
 971         struct nvme_tcp_hdr *hdr = &queue->pdu.cmd.hdr;
 972         int len;
 973         struct kvec iov;
 974         struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
 975
 976 recv:
 977         iov.iov_base = (void *)&queue->pdu + queue->offset;
 978         iov.iov_len = queue->left;
 979         len = kernel_recvmsg(queue->sock, &msg, &iov, 1,
 980                         iov.iov_len, msg.msg_flags);
 981         if (unlikely(len < 0))
 982                 return len;
 983
 984         queue->offset += len;
 985         queue->left -= len;
 986         if (queue->left)
 987                 return -EAGAIN;
 988
 989         if (queue->offset == sizeof(struct nvme_tcp_hdr)) {
 990                 u8 hdgst = nvmet_tcp_hdgst_len(queue);
 991
 992                 if (unlikely(!nvmet_tcp_pdu_valid(hdr->type))) {
 993                         pr_err("unexpected pdu type %d\n", hdr->type);
 994                         nvmet_tcp_fatal_error(queue);
 995                         return -EIO;
 996                 }
 997
 998                 if (unlikely(hdr->hlen != nvmet_tcp_pdu_size(hdr->type))) {
 999                         pr_err("pdu %d bad hlen %d\n", hdr->type, hdr->hlen);
1000                         return -EIO;
1001                 }
1002
1003                 queue->left = hdr->hlen - queue->offset + hdgst;
1004                 goto recv;
1005         }
1006
1007         if (queue->hdr_digest &&
1008             nvmet_tcp_verify_hdgst(queue, &queue->pdu, queue->offset)) {
1009                 nvmet_tcp_fatal_error(queue); /* fatal */
1010                 return -EPROTO;
1011         }
1012
1013         if (queue->data_digest &&
1014             nvmet_tcp_check_ddgst(queue, &queue->pdu)) {
1015                 nvmet_tcp_fatal_error(queue); /* fatal */
1016                 return -EPROTO;
1017         }
1018
1019         return nvmet_tcp_done_recv_pdu(queue);
1020 }
1021
1022 static void nvmet_tcp_prep_recv_ddgst(struct nvmet_tcp_cmd *cmd)
1023 {
1024         struct nvmet_tcp_queue *queue = cmd->queue;
1025
1026         nvmet_tcp_ddgst(queue->rcv_hash, cmd);
1027         queue->offset = 0;
1028         queue->left = NVME_TCP_DIGEST_LENGTH;
1029         queue->rcv_state = NVMET_TCP_RECV_DDGST;
1030 }
1031
1032 static int nvmet_tcp_try_recv_data(struct nvmet_tcp_queue *queue)
1033 {
1034         struct nvmet_tcp_cmd  *cmd = queue->cmd;
1035         int ret;
1036
1037         while (msg_data_left(&cmd->recv_msg)) {
1038                 ret = sock_recvmsg(cmd->queue->sock, &cmd->recv_msg,
1039                         cmd->recv_msg.msg_flags);
1040                 if (ret <= 0)
1041                         return ret;
1042
1043                 cmd->pdu_recv += ret;
1044                 cmd->rbytes_done += ret;
1045         }
1046
1047         nvmet_tcp_unmap_pdu_iovec(cmd);
1048
1049         if (!(cmd->flags & NVMET_TCP_F_INIT_FAILED) &&
1050             cmd->rbytes_done == cmd->req.transfer_len) {
1051                 if (queue->data_digest) {
1052                         nvmet_tcp_prep_recv_ddgst(cmd);
1053                         return 0;
1054                 }
1055                 nvmet_req_execute(&cmd->req);
1056         }
1057
1058         nvmet_prepare_receive_pdu(queue);
1059         return 0;
1060 }
1061
1062 static int nvmet_tcp_try_recv_ddgst(struct nvmet_tcp_queue *queue)
1063 {
1064         struct nvmet_tcp_cmd *cmd = queue->cmd;
1065         int ret;
1066         struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
1067         struct kvec iov = {
1068                 .iov_base = (void *)&cmd->recv_ddgst + queue->offset,
1069                 .iov_len = queue->left
1070         };
1071
1072         ret = kernel_recvmsg(queue->sock, &msg, &iov, 1,
1073                         iov.iov_len, msg.msg_flags);
1074         if (unlikely(ret < 0))
1075                 return ret;
1076
1077         queue->offset += ret;
1078         queue->left -= ret;
1079         if (queue->left)
1080                 return -EAGAIN;
1081
1082         if (queue->data_digest && cmd->exp_ddgst != cmd->recv_ddgst) {
1083                 pr_err("queue %d: cmd %d pdu (%d) data digest error: recv %#x expected %#x\n",
1084                         queue->idx, cmd->req.cmd->common.command_id,
1085                         queue->pdu.cmd.hdr.type, le32_to_cpu(cmd->recv_ddgst),
1086                         le32_to_cpu(cmd->exp_ddgst));
1087                 nvmet_tcp_finish_cmd(cmd);
1088                 nvmet_tcp_fatal_error(queue);
1089                 ret = -EPROTO;
1090                 goto out;
1091         }
1092
1093         if (!(cmd->flags & NVMET_TCP_F_INIT_FAILED) &&
1094             cmd->rbytes_done == cmd->req.transfer_len)
1095                 nvmet_req_execute(&cmd->req);
1096         ret = 0;
1097 out:
1098         nvmet_prepare_receive_pdu(queue);
1099         return ret;
1100 }
1101
1102 static int nvmet_tcp_try_recv_one(struct nvmet_tcp_queue *queue)
1103 {
1104         int result = 0;
1105
1106         if (unlikely(queue->rcv_state == NVMET_TCP_RECV_ERR))
1107                 return 0;
1108
1109         if (queue->rcv_state == NVMET_TCP_RECV_PDU) {
1110                 result = nvmet_tcp_try_recv_pdu(queue);
1111                 if (result != 0)
1112                         goto done_recv;
1113         }
1114
1115         if (queue->rcv_state == NVMET_TCP_RECV_DATA) {
1116                 result = nvmet_tcp_try_recv_data(queue);
1117                 if (result != 0)
1118                         goto done_recv;
1119         }
1120
1121         if (queue->rcv_state == NVMET_TCP_RECV_DDGST) {
1122                 result = nvmet_tcp_try_recv_ddgst(queue);
1123                 if (result != 0)
1124                         goto done_recv;
1125         }
1126
1127 done_recv:
1128         if (result < 0) {
1129                 if (result == -EAGAIN)
1130                         return 0;
1131                 return result;
1132         }
1133         return 1;
1134 }
1135
1136 static int nvmet_tcp_try_recv(struct nvmet_tcp_queue *queue,
1137                 int budget, int *recvs)
1138 {
1139         int i, ret = 0;
1140
1141         for (i = 0; i < budget; i++) {
1142                 ret = nvmet_tcp_try_recv_one(queue);
1143                 if (ret <= 0)
1144                         break;
1145                 (*recvs)++;
1146         }
1147
1148         return ret;
1149 }
1150
1151 static void nvmet_tcp_schedule_release_queue(struct nvmet_tcp_queue *queue)
1152 {
1153         spin_lock(&queue->state_lock);
1154         if (queue->state != NVMET_TCP_Q_DISCONNECTING) {
1155                 queue->state = NVMET_TCP_Q_DISCONNECTING;
1156                 schedule_work(&queue->release_work);
1157         }
1158         spin_unlock(&queue->state_lock);
1159 }
1160
1161 static void nvmet_tcp_io_work(struct work_struct *w)
1162 {
1163         struct nvmet_tcp_queue *queue =
1164                 container_of(w, struct nvmet_tcp_queue, io_work);
1165         bool pending;
1166         int ret, ops = 0;
1167
1168         do {
1169                 pending = false;
1170
1171                 ret = nvmet_tcp_try_recv(queue, NVMET_TCP_RECV_BUDGET, &ops);
1172                 if (ret > 0) {
1173                         pending = true;
1174                 } else if (ret < 0) {
1175                         if (ret == -EPIPE || ret == -ECONNRESET)
1176                                 kernel_sock_shutdown(queue->sock, SHUT_RDWR);
1177                         else
1178                                 nvmet_tcp_fatal_error(queue);
1179                         return;
1180                 }
1181
1182                 ret = nvmet_tcp_try_send(queue, NVMET_TCP_SEND_BUDGET, &ops);
1183                 if (ret > 0) {
1184                         /* transmitted message/data */
1185                         pending = true;
1186                 } else if (ret < 0) {
1187                         if (ret == -EPIPE || ret == -ECONNRESET)
1188                                 kernel_sock_shutdown(queue->sock, SHUT_RDWR);
1189                         else
1190                                 nvmet_tcp_fatal_error(queue);
1191                         return;
1192                 }
1193
1194         } while (pending && ops < NVMET_TCP_IO_WORK_BUDGET);
1195
1196         /*
1197          * We exahusted our budget, requeue our selves
1198          */
1199         if (pending)
1200                 queue_work_on(queue->cpu, nvmet_tcp_wq, &queue->io_work);
1201 }
1202
1203 static int nvmet_tcp_alloc_cmd(struct nvmet_tcp_queue *queue,
1204                 struct nvmet_tcp_cmd *c)
1205 {
1206         u8 hdgst = nvmet_tcp_hdgst_len(queue);
1207
1208         c->queue = queue;
1209         c->req.port = queue->port->nport;
1210
1211         c->cmd_pdu = page_frag_alloc(&queue->pf_cache,
1212                         sizeof(*c->cmd_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1213         if (!c->cmd_pdu)
1214                 return -ENOMEM;
1215         c->req.cmd = &c->cmd_pdu->cmd;
1216
1217         c->rsp_pdu = page_frag_alloc(&queue->pf_cache,
1218                         sizeof(*c->rsp_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1219         if (!c->rsp_pdu)
1220                 goto out_free_cmd;
1221         c->req.cqe = &c->rsp_pdu->cqe;
1222
1223         c->data_pdu = page_frag_alloc(&queue->pf_cache,
1224                         sizeof(*c->data_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1225         if (!c->data_pdu)
1226                 goto out_free_rsp;
1227
1228         c->r2t_pdu = page_frag_alloc(&queue->pf_cache,
1229                         sizeof(*c->r2t_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1230         if (!c->r2t_pdu)
1231                 goto out_free_data;
1232
1233         c->recv_msg.msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
1234
1235         list_add_tail(&c->entry, &queue->free_list);
1236
1237         return 0;
1238 out_free_data:
1239         page_frag_free(c->data_pdu);
1240 out_free_rsp:
1241         page_frag_free(c->rsp_pdu);
1242 out_free_cmd:
1243         page_frag_free(c->cmd_pdu);
1244         return -ENOMEM;
1245 }
1246
1247 static void nvmet_tcp_free_cmd(struct nvmet_tcp_cmd *c)
1248 {
1249         page_frag_free(c->r2t_pdu);
1250         page_frag_free(c->data_pdu);
1251         page_frag_free(c->rsp_pdu);
1252         page_frag_free(c->cmd_pdu);
1253 }
1254
1255 static int nvmet_tcp_alloc_cmds(struct nvmet_tcp_queue *queue)
1256 {
1257         struct nvmet_tcp_cmd *cmds;
1258         int i, ret = -EINVAL, nr_cmds = queue->nr_cmds;
1259
1260         cmds = kcalloc(nr_cmds, sizeof(struct nvmet_tcp_cmd), GFP_KERNEL);
1261         if (!cmds)
1262                 goto out;
1263
1264         for (i = 0; i < nr_cmds; i++) {
1265                 ret = nvmet_tcp_alloc_cmd(queue, cmds + i);
1266                 if (ret)
1267                         goto out_free;
1268         }
1269
1270         queue->cmds = cmds;
1271
1272         return 0;
1273 out_free:
1274         while (--i >= 0)
1275                 nvmet_tcp_free_cmd(cmds + i);
1276         kfree(cmds);
1277 out:
1278         return ret;
1279 }
1280
1281 static void nvmet_tcp_free_cmds(struct nvmet_tcp_queue *queue)
1282 {
1283         struct nvmet_tcp_cmd *cmds = queue->cmds;
1284         int i;
1285
1286         for (i = 0; i < queue->nr_cmds; i++)
1287                 nvmet_tcp_free_cmd(cmds + i);
1288
1289         nvmet_tcp_free_cmd(&queue->connect);
1290         kfree(cmds);
1291 }
1292
1293 static void nvmet_tcp_restore_socket_callbacks(struct nvmet_tcp_queue *queue)
1294 {
1295         struct socket *sock = queue->sock;
1296
1297         write_lock_bh(&sock->sk->sk_callback_lock);
1298         sock->sk->sk_data_ready =  queue->data_ready;
1299         sock->sk->sk_state_change = queue->state_change;
1300         sock->sk->sk_write_space = queue->write_space;
1301         sock->sk->sk_user_data = NULL;
1302         write_unlock_bh(&sock->sk->sk_callback_lock);
1303 }
1304
1305 static void nvmet_tcp_finish_cmd(struct nvmet_tcp_cmd *cmd)
1306 {
1307         nvmet_req_uninit(&cmd->req);
1308         nvmet_tcp_unmap_pdu_iovec(cmd);
1309         sgl_free(cmd->req.sg);
1310 }
1311
1312 static void nvmet_tcp_uninit_data_in_cmds(struct nvmet_tcp_queue *queue)
1313 {
1314         struct nvmet_tcp_cmd *cmd = queue->cmds;
1315         int i;
1316
1317         for (i = 0; i < queue->nr_cmds; i++, cmd++) {
1318                 if (nvmet_tcp_need_data_in(cmd))
1319                         nvmet_tcp_finish_cmd(cmd);
1320         }
1321
1322         if (!queue->nr_cmds && nvmet_tcp_need_data_in(&queue->connect)) {
1323                 /* failed in connect */
1324                 nvmet_tcp_finish_cmd(&queue->connect);
1325         }
1326 }
1327
1328 static void nvmet_tcp_release_queue_work(struct work_struct *w)
1329 {
1330         struct nvmet_tcp_queue *queue =
1331                 container_of(w, struct nvmet_tcp_queue, release_work);
1332
1333         mutex_lock(&nvmet_tcp_queue_mutex);
1334         list_del_init(&queue->queue_list);
1335         mutex_unlock(&nvmet_tcp_queue_mutex);
1336
1337         nvmet_tcp_restore_socket_callbacks(queue);
1338         flush_work(&queue->io_work);
1339
1340         nvmet_tcp_uninit_data_in_cmds(queue);
1341         nvmet_sq_destroy(&queue->nvme_sq);
1342         cancel_work_sync(&queue->io_work);
1343         sock_release(queue->sock);
1344         nvmet_tcp_free_cmds(queue);
1345         if (queue->hdr_digest || queue->data_digest)
1346                 nvmet_tcp_free_crypto(queue);
1347         ida_simple_remove(&nvmet_tcp_queue_ida, queue->idx);
1348
1349         kfree(queue);
1350 }
1351
1352 static void nvmet_tcp_data_ready(struct sock *sk)
1353 {
1354         struct nvmet_tcp_queue *queue;
1355
1356         read_lock_bh(&sk->sk_callback_lock);
1357         queue = sk->sk_user_data;
1358         if (likely(queue))
1359                 queue_work_on(queue->cpu, nvmet_tcp_wq, &queue->io_work);
1360         read_unlock_bh(&sk->sk_callback_lock);
1361 }
1362
1363 static void nvmet_tcp_write_space(struct sock *sk)
1364 {
1365         struct nvmet_tcp_queue *queue;
1366
1367         read_lock_bh(&sk->sk_callback_lock);
1368         queue = sk->sk_user_data;
1369         if (unlikely(!queue))
1370                 goto out;
1371
1372         if (unlikely(queue->state == NVMET_TCP_Q_CONNECTING)) {
1373                 queue->write_space(sk);
1374                 goto out;
1375         }
1376
1377         if (sk_stream_is_writeable(sk)) {
1378                 clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1379                 queue_work_on(queue->cpu, nvmet_tcp_wq, &queue->io_work);
1380         }
1381 out:
1382         read_unlock_bh(&sk->sk_callback_lock);
1383 }
1384
1385 static void nvmet_tcp_state_change(struct sock *sk)
1386 {
1387         struct nvmet_tcp_queue *queue;
1388
1389         write_lock_bh(&sk->sk_callback_lock);
1390         queue = sk->sk_user_data;
1391         if (!queue)
1392                 goto done;
1393
1394         switch (sk->sk_state) {
1395         case TCP_FIN_WAIT1:
1396         case TCP_CLOSE_WAIT:
1397         case TCP_CLOSE:
1398                 /* FALLTHRU */
1399                 sk->sk_user_data = NULL;
1400                 nvmet_tcp_schedule_release_queue(queue);
1401                 break;
1402         default:
1403                 pr_warn("queue %d unhandled state %d\n",
1404                         queue->idx, sk->sk_state);
1405         }
1406 done:
1407         write_unlock_bh(&sk->sk_callback_lock);
1408 }
1409
1410 static int nvmet_tcp_set_queue_sock(struct nvmet_tcp_queue *queue)
1411 {
1412         struct socket *sock = queue->sock;
1413         struct linger sol = { .l_onoff = 1, .l_linger = 0 };
1414         int ret;
1415
1416         ret = kernel_getsockname(sock,
1417                 (struct sockaddr *)&queue->sockaddr);
1418         if (ret < 0)
1419                 return ret;
1420
1421         ret = kernel_getpeername(sock,
1422                 (struct sockaddr *)&queue->sockaddr_peer);
1423         if (ret < 0)
1424                 return ret;
1425
1426         /*
1427          * Cleanup whatever is sitting in the TCP transmit queue on socket
1428          * close. This is done to prevent stale data from being sent should
1429          * the network connection be restored before TCP times out.
1430          */
1431         ret = kernel_setsockopt(sock, SOL_SOCKET, SO_LINGER,
1432                         (char *)&sol, sizeof(sol));
1433         if (ret)
1434                 return ret;
1435
1436         write_lock_bh(&sock->sk->sk_callback_lock);
1437         sock->sk->sk_user_data = queue;
1438         queue->data_ready = sock->sk->sk_data_ready;
1439         sock->sk->sk_data_ready = nvmet_tcp_data_ready;
1440         queue->state_change = sock->sk->sk_state_change;
1441         sock->sk->sk_state_change = nvmet_tcp_state_change;
1442         queue->write_space = sock->sk->sk_write_space;
1443         sock->sk->sk_write_space = nvmet_tcp_write_space;
1444         write_unlock_bh(&sock->sk->sk_callback_lock);
1445
1446         return 0;
1447 }
1448
1449 static int nvmet_tcp_alloc_queue(struct nvmet_tcp_port *port,
1450                 struct socket *newsock)
1451 {
1452         struct nvmet_tcp_queue *queue;
1453         int ret;
1454
1455         queue = kzalloc(sizeof(*queue), GFP_KERNEL);
1456         if (!queue)
1457                 return -ENOMEM;
1458
1459         INIT_WORK(&queue->release_work, nvmet_tcp_release_queue_work);
1460         INIT_WORK(&queue->io_work, nvmet_tcp_io_work);
1461         queue->sock = newsock;
1462         queue->port = port;
1463         queue->nr_cmds = 0;
1464         spin_lock_init(&queue->state_lock);
1465         queue->state = NVMET_TCP_Q_CONNECTING;
1466         INIT_LIST_HEAD(&queue->free_list);
1467         init_llist_head(&queue->resp_list);
1468         INIT_LIST_HEAD(&queue->resp_send_list);
1469
1470         queue->idx = ida_simple_get(&nvmet_tcp_queue_ida, 0, 0, GFP_KERNEL);
1471         if (queue->idx < 0) {
1472                 ret = queue->idx;
1473                 goto out_free_queue;
1474         }
1475
1476         ret = nvmet_tcp_alloc_cmd(queue, &queue->connect);
1477         if (ret)
1478                 goto out_ida_remove;
1479
1480         ret = nvmet_sq_init(&queue->nvme_sq);
1481         if (ret)
1482                 goto out_free_connect;
1483
1484         port->last_cpu = cpumask_next_wrap(port->last_cpu,
1485                                 cpu_online_mask, -1, false);
1486         queue->cpu = port->last_cpu;
1487         nvmet_prepare_receive_pdu(queue);
1488
1489         mutex_lock(&nvmet_tcp_queue_mutex);
1490         list_add_tail(&queue->queue_list, &nvmet_tcp_queue_list);
1491         mutex_unlock(&nvmet_tcp_queue_mutex);
1492
1493         ret = nvmet_tcp_set_queue_sock(queue);
1494         if (ret)
1495                 goto out_destroy_sq;
1496
1497         queue_work_on(queue->cpu, nvmet_tcp_wq, &queue->io_work);
1498
1499         return 0;
1500 out_destroy_sq:
1501         mutex_lock(&nvmet_tcp_queue_mutex);
1502         list_del_init(&queue->queue_list);
1503         mutex_unlock(&nvmet_tcp_queue_mutex);
1504         nvmet_sq_destroy(&queue->nvme_sq);
1505 out_free_connect:
1506         nvmet_tcp_free_cmd(&queue->connect);
1507 out_ida_remove:
1508         ida_simple_remove(&nvmet_tcp_queue_ida, queue->idx);
1509 out_free_queue:
1510         kfree(queue);
1511         return ret;
1512 }
1513
1514 static void nvmet_tcp_accept_work(struct work_struct *w)
1515 {
1516         struct nvmet_tcp_port *port =
1517                 container_of(w, struct nvmet_tcp_port, accept_work);
1518         struct socket *newsock;
1519         int ret;
1520
1521         while (true) {
1522                 ret = kernel_accept(port->sock, &newsock, O_NONBLOCK);
1523                 if (ret < 0) {
1524                         if (ret != -EAGAIN)
1525                                 pr_warn("failed to accept err=%d\n", ret);
1526                         return;
1527                 }
1528                 ret = nvmet_tcp_alloc_queue(port, newsock);
1529                 if (ret) {
1530                         pr_err("failed to allocate queue\n");
1531                         sock_release(newsock);
1532                 }
1533         }
1534 }
1535
1536 static void nvmet_tcp_listen_data_ready(struct sock *sk)
1537 {
1538         struct nvmet_tcp_port *port;
1539
1540         read_lock_bh(&sk->sk_callback_lock);
1541         port = sk->sk_user_data;
1542         if (!port)
1543                 goto out;
1544
1545         if (sk->sk_state == TCP_LISTEN)
1546                 schedule_work(&port->accept_work);
1547 out:
1548         read_unlock_bh(&sk->sk_callback_lock);
1549 }
1550
1551 static int nvmet_tcp_add_port(struct nvmet_port *nport)
1552 {
1553         struct nvmet_tcp_port *port;
1554         __kernel_sa_family_t af;
1555         int opt, ret;
1556
1557         port = kzalloc(sizeof(*port), GFP_KERNEL);
1558         if (!port)
1559                 return -ENOMEM;
1560
1561         switch (nport->disc_addr.adrfam) {
1562         case NVMF_ADDR_FAMILY_IP4:
1563                 af = AF_INET;
1564                 break;
1565         case NVMF_ADDR_FAMILY_IP6:
1566                 af = AF_INET6;
1567                 break;
1568         default:
1569                 pr_err("address family %d not supported\n",
1570                                 nport->disc_addr.adrfam);
1571                 ret = -EINVAL;
1572                 goto err_port;
1573         }
1574
1575         ret = inet_pton_with_scope(&init_net, af, nport->disc_addr.traddr,
1576                         nport->disc_addr.trsvcid, &port->addr);
1577         if (ret) {
1578                 pr_err("malformed ip/port passed: %s:%s\n",
1579                         nport->disc_addr.traddr, nport->disc_addr.trsvcid);
1580                 goto err_port;
1581         }
1582
1583         port->nport = nport;
1584         port->last_cpu = -1;
1585         INIT_WORK(&port->accept_work, nvmet_tcp_accept_work);
1586         if (port->nport->inline_data_size < 0)
1587                 port->nport->inline_data_size = NVMET_TCP_DEF_INLINE_DATA_SIZE;
1588
1589         ret = sock_create(port->addr.ss_family, SOCK_STREAM,
1590                                 IPPROTO_TCP, &port->sock);
1591         if (ret) {
1592                 pr_err("failed to create a socket\n");
1593                 goto err_port;
1594         }
1595
1596         port->sock->sk->sk_user_data = port;
1597         port->data_ready = port->sock->sk->sk_data_ready;
1598         port->sock->sk->sk_data_ready = nvmet_tcp_listen_data_ready;
1599
1600         opt = 1;
1601         ret = kernel_setsockopt(port->sock, IPPROTO_TCP,
1602                         TCP_NODELAY, (char *)&opt, sizeof(opt));
1603         if (ret) {
1604                 pr_err("failed to set TCP_NODELAY sock opt %d\n", ret);
1605                 goto err_sock;
1606         }
1607
1608         ret = kernel_setsockopt(port->sock, SOL_SOCKET, SO_REUSEADDR,
1609                         (char *)&opt, sizeof(opt));
1610         if (ret) {
1611                 pr_err("failed to set SO_REUSEADDR sock opt %d\n", ret);
1612                 goto err_sock;
1613         }
1614
1615         ret = kernel_bind(port->sock, (struct sockaddr *)&port->addr,
1616                         sizeof(port->addr));
1617         if (ret) {
1618                 pr_err("failed to bind port socket %d\n", ret);
1619                 goto err_sock;
1620         }
1621
1622         ret = kernel_listen(port->sock, 128);
1623         if (ret) {
1624                 pr_err("failed to listen %d on port sock\n", ret);
1625                 goto err_sock;
1626         }
1627
1628         nport->priv = port;
1629         pr_info("enabling port %d (%pISpc)\n",
1630                 le16_to_cpu(nport->disc_addr.portid), &port->addr);
1631
1632         return 0;
1633
1634 err_sock:
1635         sock_release(port->sock);
1636 err_port:
1637         kfree(port);
1638         return ret;
1639 }
1640
1641 static void nvmet_tcp_remove_port(struct nvmet_port *nport)
1642 {
1643         struct nvmet_tcp_port *port = nport->priv;
1644
1645         write_lock_bh(&port->sock->sk->sk_callback_lock);
1646         port->sock->sk->sk_data_ready = port->data_ready;
1647         port->sock->sk->sk_user_data = NULL;
1648         write_unlock_bh(&port->sock->sk->sk_callback_lock);
1649         cancel_work_sync(&port->accept_work);
1650
1651         sock_release(port->sock);
1652         kfree(port);
1653 }
1654
1655 static void nvmet_tcp_delete_ctrl(struct nvmet_ctrl *ctrl)
1656 {
1657         struct nvmet_tcp_queue *queue;
1658
1659         mutex_lock(&nvmet_tcp_queue_mutex);
1660         list_for_each_entry(queue, &nvmet_tcp_queue_list, queue_list)
1661                 if (queue->nvme_sq.ctrl == ctrl)
1662                         kernel_sock_shutdown(queue->sock, SHUT_RDWR);
1663         mutex_unlock(&nvmet_tcp_queue_mutex);
1664 }
1665
1666 static u16 nvmet_tcp_install_queue(struct nvmet_sq *sq)
1667 {
1668         struct nvmet_tcp_queue *queue =
1669                 container_of(sq, struct nvmet_tcp_queue, nvme_sq);
1670
1671         if (sq->qid == 0) {
1672                 /* Let inflight controller teardown complete */
1673                 flush_scheduled_work();
1674         }
1675
1676         queue->nr_cmds = sq->size * 2;
1677         if (nvmet_tcp_alloc_cmds(queue))
1678                 return NVME_SC_INTERNAL;
1679         return 0;
1680 }
1681
1682 static void nvmet_tcp_disc_port_addr(struct nvmet_req *req,
1683                 struct nvmet_port *nport, char *traddr)
1684 {
1685         struct nvmet_tcp_port *port = nport->priv;
1686
1687         if (inet_addr_is_any((struct sockaddr *)&port->addr)) {
1688                 struct nvmet_tcp_cmd *cmd =
1689                         container_of(req, struct nvmet_tcp_cmd, req);
1690                 struct nvmet_tcp_queue *queue = cmd->queue;
1691
1692                 sprintf(traddr, "%pISc", (struct sockaddr *)&queue->sockaddr);
1693         } else {
1694                 memcpy(traddr, nport->disc_addr.traddr, NVMF_TRADDR_SIZE);
1695         }
1696 }
1697
1698 static struct nvmet_fabrics_ops nvmet_tcp_ops = {
1699         .owner                  = THIS_MODULE,
1700         .type                   = NVMF_TRTYPE_TCP,
1701         .msdbd                  = 1,
1702         .has_keyed_sgls         = 0,
1703         .add_port               = nvmet_tcp_add_port,
1704         .remove_port            = nvmet_tcp_remove_port,
1705         .queue_response         = nvmet_tcp_queue_response,
1706         .delete_ctrl            = nvmet_tcp_delete_ctrl,
1707         .install_queue          = nvmet_tcp_install_queue,
1708         .disc_traddr            = nvmet_tcp_disc_port_addr,
1709 };
1710
1711 static int __init nvmet_tcp_init(void)
1712 {
1713         int ret;
1714
1715         nvmet_tcp_wq = alloc_workqueue("nvmet_tcp_wq", WQ_HIGHPRI, 0);
1716         if (!nvmet_tcp_wq)
1717                 return -ENOMEM;
1718
1719         ret = nvmet_register_transport(&nvmet_tcp_ops);
1720         if (ret)
1721                 goto err;
1722
1723         return 0;
1724 err:
1725         destroy_workqueue(nvmet_tcp_wq);
1726         return ret;
1727 }
1728
1729 static void __exit nvmet_tcp_exit(void)
1730 {
1731         struct nvmet_tcp_queue *queue;
1732
1733         nvmet_unregister_transport(&nvmet_tcp_ops);
1734
1735         flush_scheduled_work();
1736         mutex_lock(&nvmet_tcp_queue_mutex);
1737         list_for_each_entry(queue, &nvmet_tcp_queue_list, queue_list)
1738                 kernel_sock_shutdown(queue->sock, SHUT_RDWR);
1739         mutex_unlock(&nvmet_tcp_queue_mutex);
1740         flush_scheduled_work();
1741
1742         destroy_workqueue(nvmet_tcp_wq);
1743 }
1744
1745 module_init(nvmet_tcp_init);
1746 module_exit(nvmet_tcp_exit);
1747
1748 MODULE_LICENSE("GPL v2");
1749 MODULE_ALIAS("nvmet-transport-3"); /* 3 == NVMF_TRTYPE_TCP */