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 the socket priority to use for connections were it is desirable
  23  * that the NIC consider performing optimized packet processing or filtering.
  24  * A non-zero value being sufficient to indicate general consideration of any
  25  * possible optimization.  Making it a module param allows for alternative
  26  * values that may be unique for some NIC implementations.
  27  */
  28 static int so_priority;
  29 module_param(so_priority, int, 0644);
  30 MODULE_PARM_DESC(so_priority, "nvmet tcp socket optimize priority");
  31
  32 #define NVMET_TCP_RECV_BUDGET           8
  33 #define NVMET_TCP_SEND_BUDGET           8
  34 #define NVMET_TCP_IO_WORK_BUDGET        64
  35
  36 enum nvmet_tcp_send_state {
  37         NVMET_TCP_SEND_DATA_PDU,
  38         NVMET_TCP_SEND_DATA,
  39         NVMET_TCP_SEND_R2T,
  40         NVMET_TCP_SEND_DDGST,
  41         NVMET_TCP_SEND_RESPONSE
  42 };
  43
  44 enum nvmet_tcp_recv_state {
  45         NVMET_TCP_RECV_PDU,
  46         NVMET_TCP_RECV_DATA,
  47         NVMET_TCP_RECV_DDGST,
  48         NVMET_TCP_RECV_ERR,
  49 };
  50
  51 enum {
  52         NVMET_TCP_F_INIT_FAILED = (1 << 0),
  53 };
  54
  55 struct nvmet_tcp_cmd {
  56         struct nvmet_tcp_queue          *queue;
  57         struct nvmet_req                req;
  58
  59         struct nvme_tcp_cmd_pdu         *cmd_pdu;
  60         struct nvme_tcp_rsp_pdu         *rsp_pdu;
  61         struct nvme_tcp_data_pdu        *data_pdu;
  62         struct nvme_tcp_r2t_pdu         *r2t_pdu;
  63
  64         u32                             rbytes_done;
  65         u32                             wbytes_done;
  66
  67         u32                             pdu_len;
  68         u32                             pdu_recv;
  69         int                             sg_idx;
  70         int                             nr_mapped;
  71         struct msghdr                   recv_msg;
  72         struct kvec                     *iov;
  73         u32                             flags;
  74
  75         struct list_head                entry;
  76         struct llist_node               lentry;
  77
  78         /* send state */
  79         u32                             offset;
  80         struct scatterlist              *cur_sg;
  81         enum nvmet_tcp_send_state       state;
  82
  83         __le32                          exp_ddgst;
  84         __le32                          recv_ddgst;
  85 };
  86
  87 enum nvmet_tcp_queue_state {
  88         NVMET_TCP_Q_CONNECTING,
  89         NVMET_TCP_Q_LIVE,
  90         NVMET_TCP_Q_DISCONNECTING,
  91 };
  92
  93 struct nvmet_tcp_queue {
  94         struct socket           *sock;
  95         struct nvmet_tcp_port   *port;
  96         struct work_struct      io_work;
  97         int                     cpu;
  98         struct nvmet_cq         nvme_cq;
  99         struct nvmet_sq         nvme_sq;
 100
 101         /* send state */
 102         struct nvmet_tcp_cmd    *cmds;
 103         unsigned int            nr_cmds;
 104         struct list_head        free_list;
 105         struct llist_head       resp_list;
 106         struct list_head        resp_send_list;
 107         int                     send_list_len;
 108         struct nvmet_tcp_cmd    *snd_cmd;
 109
 110         /* recv state */
 111         int                     offset;
 112         int                     left;
 113         enum nvmet_tcp_recv_state rcv_state;
 114         struct nvmet_tcp_cmd    *cmd;
 115         union nvme_tcp_pdu      pdu;
 116
 117         /* digest state */
 118         bool                    hdr_digest;
 119         bool                    data_digest;
 120         struct ahash_request    *snd_hash;
 121         struct ahash_request    *rcv_hash;
 122
 123         spinlock_t              state_lock;
 124         enum nvmet_tcp_queue_state state;
 125
 126         struct sockaddr_storage sockaddr;
 127         struct sockaddr_storage sockaddr_peer;
 128         struct work_struct      release_work;
 129
 130         int                     idx;
 131         struct list_head        queue_list;
 132
 133         struct nvmet_tcp_cmd    connect;
 134
 135         struct page_frag_cache  pf_cache;
 136
 137         void (*data_ready)(struct sock *);
 138         void (*state_change)(struct sock *);
 139         void (*write_space)(struct sock *);
 140 };
 141
 142 struct nvmet_tcp_port {
 143         struct socket           *sock;
 144         struct work_struct      accept_work;
 145         struct nvmet_port       *nport;
 146         struct sockaddr_storage addr;
 147         int                     last_cpu;
 148         void (*data_ready)(struct sock *);
 149 };
 150
 151 static DEFINE_IDA(nvmet_tcp_queue_ida);
 152 static LIST_HEAD(nvmet_tcp_queue_list);
 153 static DEFINE_MUTEX(nvmet_tcp_queue_mutex);
 154
 155 static struct workqueue_struct *nvmet_tcp_wq;
 156 static const struct nvmet_fabrics_ops nvmet_tcp_ops;
 157 static void nvmet_tcp_free_cmd(struct nvmet_tcp_cmd *c);
 158 static void nvmet_tcp_finish_cmd(struct nvmet_tcp_cmd *cmd);
 159
 160 static inline u16 nvmet_tcp_cmd_tag(struct nvmet_tcp_queue *queue,
 161                 struct nvmet_tcp_cmd *cmd)
 162 {
 163         return cmd - queue->cmds;
 164 }
 165
 166 static inline bool nvmet_tcp_has_data_in(struct nvmet_tcp_cmd *cmd)
 167 {
 168         return nvme_is_write(cmd->req.cmd) &&
 169                 cmd->rbytes_done < cmd->req.transfer_len;
 170 }
 171
 172 static inline bool nvmet_tcp_need_data_in(struct nvmet_tcp_cmd *cmd)
 173 {
 174         return nvmet_tcp_has_data_in(cmd) && !cmd->req.cqe->status;
 175 }
 176
 177 static inline bool nvmet_tcp_need_data_out(struct nvmet_tcp_cmd *cmd)
 178 {
 179         return !nvme_is_write(cmd->req.cmd) &&
 180                 cmd->req.transfer_len > 0 &&
 181                 !cmd->req.cqe->status;
 182 }
 183
 184 static inline bool nvmet_tcp_has_inline_data(struct nvmet_tcp_cmd *cmd)
 185 {
 186         return nvme_is_write(cmd->req.cmd) && cmd->pdu_len &&
 187                 !cmd->rbytes_done;
 188 }
 189
 190 static inline struct nvmet_tcp_cmd *
 191 nvmet_tcp_get_cmd(struct nvmet_tcp_queue *queue)
 192 {
 193         struct nvmet_tcp_cmd *cmd;
 194
 195         cmd = list_first_entry_or_null(&queue->free_list,
 196                                 struct nvmet_tcp_cmd, entry);
 197         if (!cmd)
 198                 return NULL;
 199         list_del_init(&cmd->entry);
 200
 201         cmd->rbytes_done = cmd->wbytes_done = 0;
 202         cmd->pdu_len = 0;
 203         cmd->pdu_recv = 0;
 204         cmd->iov = NULL;
 205         cmd->flags = 0;
 206         return cmd;
 207 }
 208
 209 static inline void nvmet_tcp_put_cmd(struct nvmet_tcp_cmd *cmd)
 210 {
 211         if (unlikely(cmd == &cmd->queue->connect))
 212                 return;
 213
 214         list_add_tail(&cmd->entry, &cmd->queue->free_list);
 215 }
 216
 217 static inline u8 nvmet_tcp_hdgst_len(struct nvmet_tcp_queue *queue)
 218 {
 219         return queue->hdr_digest ? NVME_TCP_DIGEST_LENGTH : 0;
 220 }
 221
 222 static inline u8 nvmet_tcp_ddgst_len(struct nvmet_tcp_queue *queue)
 223 {
 224         return queue->data_digest ? NVME_TCP_DIGEST_LENGTH : 0;
 225 }
 226
 227 static inline void nvmet_tcp_hdgst(struct ahash_request *hash,
 228                 void *pdu, size_t len)
 229 {
 230         struct scatterlist sg;
 231
 232         sg_init_one(&sg, pdu, len);
 233         ahash_request_set_crypt(hash, &sg, pdu + len, len);
 234         crypto_ahash_digest(hash);
 235 }
 236
 237 static int nvmet_tcp_verify_hdgst(struct nvmet_tcp_queue *queue,
 238         void *pdu, size_t len)
 239 {
 240         struct nvme_tcp_hdr *hdr = pdu;
 241         __le32 recv_digest;
 242         __le32 exp_digest;
 243
 244         if (unlikely(!(hdr->flags & NVME_TCP_F_HDGST))) {
 245                 pr_err("queue %d: header digest enabled but no header digest\n",
 246                         queue->idx);
 247                 return -EPROTO;
 248         }
 249
 250         recv_digest = *(__le32 *)(pdu + hdr->hlen);
 251         nvmet_tcp_hdgst(queue->rcv_hash, pdu, len);
 252         exp_digest = *(__le32 *)(pdu + hdr->hlen);
 253         if (recv_digest != exp_digest) {
 254                 pr_err("queue %d: header digest error: recv %#x expected %#x\n",
 255                         queue->idx, le32_to_cpu(recv_digest),
 256                         le32_to_cpu(exp_digest));
 257                 return -EPROTO;
 258         }
 259
 260         return 0;
 261 }
 262
 263 static int nvmet_tcp_check_ddgst(struct nvmet_tcp_queue *queue, void *pdu)
 264 {
 265         struct nvme_tcp_hdr *hdr = pdu;
 266         u8 digest_len = nvmet_tcp_hdgst_len(queue);
 267         u32 len;
 268
 269         len = le32_to_cpu(hdr->plen) - hdr->hlen -
 270                 (hdr->flags & NVME_TCP_F_HDGST ? digest_len : 0);
 271
 272         if (unlikely(len && !(hdr->flags & NVME_TCP_F_DDGST))) {
 273                 pr_err("queue %d: data digest flag is cleared\n", queue->idx);
 274                 return -EPROTO;
 275         }
 276
 277         return 0;
 278 }
 279
 280 static void nvmet_tcp_unmap_pdu_iovec(struct nvmet_tcp_cmd *cmd)
 281 {
 282         struct scatterlist *sg;
 283         int i;
 284
 285         sg = &cmd->req.sg[cmd->sg_idx];
 286
 287         for (i = 0; i < cmd->nr_mapped; i++)
 288                 kunmap(sg_page(&sg[i]));
 289 }
 290
 291 static void nvmet_tcp_map_pdu_iovec(struct nvmet_tcp_cmd *cmd)
 292 {
 293         struct kvec *iov = cmd->iov;
 294         struct scatterlist *sg;
 295         u32 length, offset, sg_offset;
 296
 297         length = cmd->pdu_len;
 298         cmd->nr_mapped = DIV_ROUND_UP(length, PAGE_SIZE);
 299         offset = cmd->rbytes_done;
 300         cmd->sg_idx = DIV_ROUND_UP(offset, PAGE_SIZE);
 301         sg_offset = offset % PAGE_SIZE;
 302         sg = &cmd->req.sg[cmd->sg_idx];
 303
 304         while (length) {
 305                 u32 iov_len = min_t(u32, length, sg->length - sg_offset);
 306
 307                 iov->iov_base = kmap(sg_page(sg)) + sg->offset + sg_offset;
 308                 iov->iov_len = iov_len;
 309
 310                 length -= iov_len;
 311                 sg = sg_next(sg);
 312                 iov++;
 313         }
 314
 315         iov_iter_kvec(&cmd->recv_msg.msg_iter, READ, cmd->iov,
 316                 cmd->nr_mapped, cmd->pdu_len);
 317 }
 318
 319 static void nvmet_tcp_fatal_error(struct nvmet_tcp_queue *queue)
 320 {
 321         queue->rcv_state = NVMET_TCP_RECV_ERR;
 322         if (queue->nvme_sq.ctrl)
 323                 nvmet_ctrl_fatal_error(queue->nvme_sq.ctrl);
 324         else
 325                 kernel_sock_shutdown(queue->sock, SHUT_RDWR);
 326 }
 327
 328 static void nvmet_tcp_socket_error(struct nvmet_tcp_queue *queue, int status)
 329 {
 330         if (status == -EPIPE || status == -ECONNRESET)
 331                 kernel_sock_shutdown(queue->sock, SHUT_RDWR);
 332         else
 333                 nvmet_tcp_fatal_error(queue);
 334 }
 335
 336 static int nvmet_tcp_map_data(struct nvmet_tcp_cmd *cmd)
 337 {
 338         struct nvme_sgl_desc *sgl = &cmd->req.cmd->common.dptr.sgl;
 339         u32 len = le32_to_cpu(sgl->length);
 340
 341         if (!len)
 342                 return 0;
 343
 344         if (sgl->type == ((NVME_SGL_FMT_DATA_DESC << 4) |
 345                           NVME_SGL_FMT_OFFSET)) {
 346                 if (!nvme_is_write(cmd->req.cmd))
 347                         return NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 348
 349                 if (len > cmd->req.port->inline_data_size)
 350                         return NVME_SC_SGL_INVALID_OFFSET | NVME_SC_DNR;
 351                 cmd->pdu_len = len;
 352         }
 353         cmd->req.transfer_len += len;
 354
 355         cmd->req.sg = sgl_alloc(len, GFP_KERNEL, &cmd->req.sg_cnt);
 356         if (!cmd->req.sg)
 357                 return NVME_SC_INTERNAL;
 358         cmd->cur_sg = cmd->req.sg;
 359
 360         if (nvmet_tcp_has_data_in(cmd)) {
 361                 cmd->iov = kmalloc_array(cmd->req.sg_cnt,
 362                                 sizeof(*cmd->iov), GFP_KERNEL);
 363                 if (!cmd->iov)
 364                         goto err;
 365         }
 366
 367         return 0;
 368 err:
 369         sgl_free(cmd->req.sg);
 370         return NVME_SC_INTERNAL;
 371 }
 372
 373 static void nvmet_tcp_ddgst(struct ahash_request *hash,
 374                 struct nvmet_tcp_cmd *cmd)
 375 {
 376         ahash_request_set_crypt(hash, cmd->req.sg,
 377                 (void *)&cmd->exp_ddgst, cmd->req.transfer_len);
 378         crypto_ahash_digest(hash);
 379 }
 380
 381 static void nvmet_setup_c2h_data_pdu(struct nvmet_tcp_cmd *cmd)
 382 {
 383         struct nvme_tcp_data_pdu *pdu = cmd->data_pdu;
 384         struct nvmet_tcp_queue *queue = cmd->queue;
 385         u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
 386         u8 ddgst = nvmet_tcp_ddgst_len(cmd->queue);
 387
 388         cmd->offset = 0;
 389         cmd->state = NVMET_TCP_SEND_DATA_PDU;
 390
 391         pdu->hdr.type = nvme_tcp_c2h_data;
 392         pdu->hdr.flags = NVME_TCP_F_DATA_LAST | (queue->nvme_sq.sqhd_disabled ?
 393                                                 NVME_TCP_F_DATA_SUCCESS : 0);
 394         pdu->hdr.hlen = sizeof(*pdu);
 395         pdu->hdr.pdo = pdu->hdr.hlen + hdgst;
 396         pdu->hdr.plen =
 397                 cpu_to_le32(pdu->hdr.hlen + hdgst +
 398                                 cmd->req.transfer_len + ddgst);
 399         pdu->command_id = cmd->req.cqe->command_id;
 400         pdu->data_length = cpu_to_le32(cmd->req.transfer_len);
 401         pdu->data_offset = cpu_to_le32(cmd->wbytes_done);
 402
 403         if (queue->data_digest) {
 404                 pdu->hdr.flags |= NVME_TCP_F_DDGST;
 405                 nvmet_tcp_ddgst(queue->snd_hash, cmd);
 406         }
 407
 408         if (cmd->queue->hdr_digest) {
 409                 pdu->hdr.flags |= NVME_TCP_F_HDGST;
 410                 nvmet_tcp_hdgst(queue->snd_hash, pdu, sizeof(*pdu));
 411         }
 412 }
 413
 414 static void nvmet_setup_r2t_pdu(struct nvmet_tcp_cmd *cmd)
 415 {
 416         struct nvme_tcp_r2t_pdu *pdu = cmd->r2t_pdu;
 417         struct nvmet_tcp_queue *queue = cmd->queue;
 418         u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
 419
 420         cmd->offset = 0;
 421         cmd->state = NVMET_TCP_SEND_R2T;
 422
 423         pdu->hdr.type = nvme_tcp_r2t;
 424         pdu->hdr.flags = 0;
 425         pdu->hdr.hlen = sizeof(*pdu);
 426         pdu->hdr.pdo = 0;
 427         pdu->hdr.plen = cpu_to_le32(pdu->hdr.hlen + hdgst);
 428
 429         pdu->command_id = cmd->req.cmd->common.command_id;
 430         pdu->ttag = nvmet_tcp_cmd_tag(cmd->queue, cmd);
 431         pdu->r2t_length = cpu_to_le32(cmd->req.transfer_len - cmd->rbytes_done);
 432         pdu->r2t_offset = cpu_to_le32(cmd->rbytes_done);
 433         if (cmd->queue->hdr_digest) {
 434                 pdu->hdr.flags |= NVME_TCP_F_HDGST;
 435                 nvmet_tcp_hdgst(queue->snd_hash, pdu, sizeof(*pdu));
 436         }
 437 }
 438
 439 static void nvmet_setup_response_pdu(struct nvmet_tcp_cmd *cmd)
 440 {
 441         struct nvme_tcp_rsp_pdu *pdu = cmd->rsp_pdu;
 442         struct nvmet_tcp_queue *queue = cmd->queue;
 443         u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
 444
 445         cmd->offset = 0;
 446         cmd->state = NVMET_TCP_SEND_RESPONSE;
 447
 448         pdu->hdr.type = nvme_tcp_rsp;
 449         pdu->hdr.flags = 0;
 450         pdu->hdr.hlen = sizeof(*pdu);
 451         pdu->hdr.pdo = 0;
 452         pdu->hdr.plen = cpu_to_le32(pdu->hdr.hlen + hdgst);
 453         if (cmd->queue->hdr_digest) {
 454                 pdu->hdr.flags |= NVME_TCP_F_HDGST;
 455                 nvmet_tcp_hdgst(queue->snd_hash, pdu, sizeof(*pdu));
 456         }
 457 }
 458
 459 static void nvmet_tcp_process_resp_list(struct nvmet_tcp_queue *queue)
 460 {
 461         struct llist_node *node;
 462         struct nvmet_tcp_cmd *cmd;
 463
 464         for (node = llist_del_all(&queue->resp_list); node; node = node->next) {
 465                 cmd = llist_entry(node, struct nvmet_tcp_cmd, lentry);
 466                 list_add(&cmd->entry, &queue->resp_send_list);
 467                 queue->send_list_len++;
 468         }
 469 }
 470
 471 static struct nvmet_tcp_cmd *nvmet_tcp_fetch_cmd(struct nvmet_tcp_queue *queue)
 472 {
 473         queue->snd_cmd = list_first_entry_or_null(&queue->resp_send_list,
 474                                 struct nvmet_tcp_cmd, entry);
 475         if (!queue->snd_cmd) {
 476                 nvmet_tcp_process_resp_list(queue);
 477                 queue->snd_cmd =
 478                         list_first_entry_or_null(&queue->resp_send_list,
 479                                         struct nvmet_tcp_cmd, entry);
 480                 if (unlikely(!queue->snd_cmd))
 481                         return NULL;
 482         }
 483
 484         list_del_init(&queue->snd_cmd->entry);
 485         queue->send_list_len--;
 486
 487         if (nvmet_tcp_need_data_out(queue->snd_cmd))
 488                 nvmet_setup_c2h_data_pdu(queue->snd_cmd);
 489         else if (nvmet_tcp_need_data_in(queue->snd_cmd))
 490                 nvmet_setup_r2t_pdu(queue->snd_cmd);
 491         else
 492                 nvmet_setup_response_pdu(queue->snd_cmd);
 493
 494         return queue->snd_cmd;
 495 }
 496
 497 static void nvmet_tcp_queue_response(struct nvmet_req *req)
 498 {
 499         struct nvmet_tcp_cmd *cmd =
 500                 container_of(req, struct nvmet_tcp_cmd, req);
 501         struct nvmet_tcp_queue  *queue = cmd->queue;
 502
 503         llist_add(&cmd->lentry, &queue->resp_list);
 504         queue_work_on(cmd->queue->cpu, nvmet_tcp_wq, &cmd->queue->io_work);
 505 }
 506
 507 static int nvmet_try_send_data_pdu(struct nvmet_tcp_cmd *cmd)
 508 {
 509         u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
 510         int left = sizeof(*cmd->data_pdu) - cmd->offset + hdgst;
 511         int ret;
 512
 513         ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->data_pdu),
 514                         offset_in_page(cmd->data_pdu) + cmd->offset,
 515                         left, MSG_DONTWAIT | MSG_MORE | MSG_SENDPAGE_NOTLAST);
 516         if (ret <= 0)
 517                 return ret;
 518
 519         cmd->offset += ret;
 520         left -= ret;
 521
 522         if (left)
 523                 return -EAGAIN;
 524
 525         cmd->state = NVMET_TCP_SEND_DATA;
 526         cmd->offset  = 0;
 527         return 1;
 528 }
 529
 530 static int nvmet_try_send_data(struct nvmet_tcp_cmd *cmd, bool last_in_batch)
 531 {
 532         struct nvmet_tcp_queue *queue = cmd->queue;
 533         int ret;
 534
 535         while (cmd->cur_sg) {
 536                 struct page *page = sg_page(cmd->cur_sg);
 537                 u32 left = cmd->cur_sg->length - cmd->offset;
 538                 int flags = MSG_DONTWAIT;
 539
 540                 if ((!last_in_batch && cmd->queue->send_list_len) ||
 541                     cmd->wbytes_done + left < cmd->req.transfer_len ||
 542                     queue->data_digest || !queue->nvme_sq.sqhd_disabled)
 543                         flags |= MSG_MORE | MSG_SENDPAGE_NOTLAST;
 544
 545                 ret = kernel_sendpage(cmd->queue->sock, page, cmd->offset,
 546                                         left, flags);
 547                 if (ret <= 0)
 548                         return ret;
 549
 550                 cmd->offset += ret;
 551                 cmd->wbytes_done += ret;
 552
 553                 /* Done with sg?*/
 554                 if (cmd->offset == cmd->cur_sg->length) {
 555                         cmd->cur_sg = sg_next(cmd->cur_sg);
 556                         cmd->offset = 0;
 557                 }
 558         }
 559
 560         if (queue->data_digest) {
 561                 cmd->state = NVMET_TCP_SEND_DDGST;
 562                 cmd->offset = 0;
 563         } else {
 564                 if (queue->nvme_sq.sqhd_disabled) {
 565                         cmd->queue->snd_cmd = NULL;
 566                         nvmet_tcp_put_cmd(cmd);
 567                 } else {
 568                         nvmet_setup_response_pdu(cmd);
 569                 }
 570         }
 571
 572         if (queue->nvme_sq.sqhd_disabled) {
 573                 kfree(cmd->iov);
 574                 sgl_free(cmd->req.sg);
 575         }
 576
 577         return 1;
 578
 579 }
 580
 581 static int nvmet_try_send_response(struct nvmet_tcp_cmd *cmd,
 582                 bool last_in_batch)
 583 {
 584         u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
 585         int left = sizeof(*cmd->rsp_pdu) - cmd->offset + hdgst;
 586         int flags = MSG_DONTWAIT;
 587         int ret;
 588
 589         if (!last_in_batch && cmd->queue->send_list_len)
 590                 flags |= MSG_MORE | MSG_SENDPAGE_NOTLAST;
 591         else
 592                 flags |= MSG_EOR;
 593
 594         ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->rsp_pdu),
 595                 offset_in_page(cmd->rsp_pdu) + cmd->offset, left, flags);
 596         if (ret <= 0)
 597                 return ret;
 598         cmd->offset += ret;
 599         left -= ret;
 600
 601         if (left)
 602                 return -EAGAIN;
 603
 604         kfree(cmd->iov);
 605         sgl_free(cmd->req.sg);
 606         cmd->queue->snd_cmd = NULL;
 607         nvmet_tcp_put_cmd(cmd);
 608         return 1;
 609 }
 610
 611 static int nvmet_try_send_r2t(struct nvmet_tcp_cmd *cmd, bool last_in_batch)
 612 {
 613         u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
 614         int left = sizeof(*cmd->r2t_pdu) - cmd->offset + hdgst;
 615         int flags = MSG_DONTWAIT;
 616         int ret;
 617
 618         if (!last_in_batch && cmd->queue->send_list_len)
 619                 flags |= MSG_MORE | MSG_SENDPAGE_NOTLAST;
 620         else
 621                 flags |= MSG_EOR;
 622
 623         ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->r2t_pdu),
 624                 offset_in_page(cmd->r2t_pdu) + cmd->offset, left, flags);
 625         if (ret <= 0)
 626                 return ret;
 627         cmd->offset += ret;
 628         left -= ret;
 629
 630         if (left)
 631                 return -EAGAIN;
 632
 633         cmd->queue->snd_cmd = NULL;
 634         return 1;
 635 }
 636
 637 static int nvmet_try_send_ddgst(struct nvmet_tcp_cmd *cmd, bool last_in_batch)
 638 {
 639         struct nvmet_tcp_queue *queue = cmd->queue;
 640         struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
 641         struct kvec iov = {
 642                 .iov_base = &cmd->exp_ddgst + cmd->offset,
 643                 .iov_len = NVME_TCP_DIGEST_LENGTH - cmd->offset
 644         };
 645         int ret;
 646
 647         if (!last_in_batch && cmd->queue->send_list_len)
 648                 msg.msg_flags |= MSG_MORE;
 649         else
 650                 msg.msg_flags |= MSG_EOR;
 651
 652         ret = kernel_sendmsg(queue->sock, &msg, &iov, 1, iov.iov_len);
 653         if (unlikely(ret <= 0))
 654                 return ret;
 655
 656         cmd->offset += ret;
 657
 658         if (queue->nvme_sq.sqhd_disabled) {
 659                 cmd->queue->snd_cmd = NULL;
 660                 nvmet_tcp_put_cmd(cmd);
 661         } else {
 662                 nvmet_setup_response_pdu(cmd);
 663         }
 664         return 1;
 665 }
 666
 667 static int nvmet_tcp_try_send_one(struct nvmet_tcp_queue *queue,
 668                 bool last_in_batch)
 669 {
 670         struct nvmet_tcp_cmd *cmd = queue->snd_cmd;
 671         int ret = 0;
 672
 673         if (!cmd || queue->state == NVMET_TCP_Q_DISCONNECTING) {
 674                 cmd = nvmet_tcp_fetch_cmd(queue);
 675                 if (unlikely(!cmd))
 676                         return 0;
 677         }
 678
 679         if (cmd->state == NVMET_TCP_SEND_DATA_PDU) {
 680                 ret = nvmet_try_send_data_pdu(cmd);
 681                 if (ret <= 0)
 682                         goto done_send;
 683         }
 684
 685         if (cmd->state == NVMET_TCP_SEND_DATA) {
 686                 ret = nvmet_try_send_data(cmd, last_in_batch);
 687                 if (ret <= 0)
 688                         goto done_send;
 689         }
 690
 691         if (cmd->state == NVMET_TCP_SEND_DDGST) {
 692                 ret = nvmet_try_send_ddgst(cmd, last_in_batch);
 693                 if (ret <= 0)
 694                         goto done_send;
 695         }
 696
 697         if (cmd->state == NVMET_TCP_SEND_R2T) {
 698                 ret = nvmet_try_send_r2t(cmd, last_in_batch);
 699                 if (ret <= 0)
 700                         goto done_send;
 701         }
 702
 703         if (cmd->state == NVMET_TCP_SEND_RESPONSE)
 704                 ret = nvmet_try_send_response(cmd, last_in_batch);
 705
 706 done_send:
 707         if (ret < 0) {
 708                 if (ret == -EAGAIN)
 709                         return 0;
 710                 return ret;
 711         }
 712
 713         return 1;
 714 }
 715
 716 static int nvmet_tcp_try_send(struct nvmet_tcp_queue *queue,
 717                 int budget, int *sends)
 718 {
 719         int i, ret = 0;
 720
 721         for (i = 0; i < budget; i++) {
 722                 ret = nvmet_tcp_try_send_one(queue, i == budget - 1);
 723                 if (unlikely(ret < 0)) {
 724                         nvmet_tcp_socket_error(queue, ret);
 725                         goto done;
 726                 } else if (ret == 0) {
 727                         break;
 728                 }
 729                 (*sends)++;
 730         }
 731 done:
 732         return ret;
 733 }
 734
 735 static void nvmet_prepare_receive_pdu(struct nvmet_tcp_queue *queue)
 736 {
 737         queue->offset = 0;
 738         queue->left = sizeof(struct nvme_tcp_hdr);
 739         queue->cmd = NULL;
 740         queue->rcv_state = NVMET_TCP_RECV_PDU;
 741 }
 742
 743 static void nvmet_tcp_free_crypto(struct nvmet_tcp_queue *queue)
 744 {
 745         struct crypto_ahash *tfm = crypto_ahash_reqtfm(queue->rcv_hash);
 746
 747         ahash_request_free(queue->rcv_hash);
 748         ahash_request_free(queue->snd_hash);
 749         crypto_free_ahash(tfm);
 750 }
 751
 752 static int nvmet_tcp_alloc_crypto(struct nvmet_tcp_queue *queue)
 753 {
 754         struct crypto_ahash *tfm;
 755
 756         tfm = crypto_alloc_ahash("crc32c", 0, CRYPTO_ALG_ASYNC);
 757         if (IS_ERR(tfm))
 758                 return PTR_ERR(tfm);
 759
 760         queue->snd_hash = ahash_request_alloc(tfm, GFP_KERNEL);
 761         if (!queue->snd_hash)
 762                 goto free_tfm;
 763         ahash_request_set_callback(queue->snd_hash, 0, NULL, NULL);
 764
 765         queue->rcv_hash = ahash_request_alloc(tfm, GFP_KERNEL);
 766         if (!queue->rcv_hash)
 767                 goto free_snd_hash;
 768         ahash_request_set_callback(queue->rcv_hash, 0, NULL, NULL);
 769
 770         return 0;
 771 free_snd_hash:
 772         ahash_request_free(queue->snd_hash);
 773 free_tfm:
 774         crypto_free_ahash(tfm);
 775         return -ENOMEM;
 776 }
 777
 778
 779 static int nvmet_tcp_handle_icreq(struct nvmet_tcp_queue *queue)
 780 {
 781         struct nvme_tcp_icreq_pdu *icreq = &queue->pdu.icreq;
 782         struct nvme_tcp_icresp_pdu *icresp = &queue->pdu.icresp;
 783         struct msghdr msg = {};
 784         struct kvec iov;
 785         int ret;
 786
 787         if (le32_to_cpu(icreq->hdr.plen) != sizeof(struct nvme_tcp_icreq_pdu)) {
 788                 pr_err("bad nvme-tcp pdu length (%d)\n",
 789                         le32_to_cpu(icreq->hdr.plen));
 790                 nvmet_tcp_fatal_error(queue);
 791         }
 792
 793         if (icreq->pfv != NVME_TCP_PFV_1_0) {
 794                 pr_err("queue %d: bad pfv %d\n", queue->idx, icreq->pfv);
 795                 return -EPROTO;
 796         }
 797
 798         if (icreq->hpda != 0) {
 799                 pr_err("queue %d: unsupported hpda %d\n", queue->idx,
 800                         icreq->hpda);
 801                 return -EPROTO;
 802         }
 803
 804         queue->hdr_digest = !!(icreq->digest & NVME_TCP_HDR_DIGEST_ENABLE);
 805         queue->data_digest = !!(icreq->digest & NVME_TCP_DATA_DIGEST_ENABLE);
 806         if (queue->hdr_digest || queue->data_digest) {
 807                 ret = nvmet_tcp_alloc_crypto(queue);
 808                 if (ret)
 809                         return ret;
 810         }
 811
 812         memset(icresp, 0, sizeof(*icresp));
 813         icresp->hdr.type = nvme_tcp_icresp;
 814         icresp->hdr.hlen = sizeof(*icresp);
 815         icresp->hdr.pdo = 0;
 816         icresp->hdr.plen = cpu_to_le32(icresp->hdr.hlen);
 817         icresp->pfv = cpu_to_le16(NVME_TCP_PFV_1_0);
 818         icresp->maxdata = cpu_to_le32(0x400000); /* 16M arbitrary limit */
 819         icresp->cpda = 0;
 820         if (queue->hdr_digest)
 821                 icresp->digest |= NVME_TCP_HDR_DIGEST_ENABLE;
 822         if (queue->data_digest)
 823                 icresp->digest |= NVME_TCP_DATA_DIGEST_ENABLE;
 824
 825         iov.iov_base = icresp;
 826         iov.iov_len = sizeof(*icresp);
 827         ret = kernel_sendmsg(queue->sock, &msg, &iov, 1, iov.iov_len);
 828         if (ret < 0)
 829                 goto free_crypto;
 830
 831         queue->state = NVMET_TCP_Q_LIVE;
 832         nvmet_prepare_receive_pdu(queue);
 833         return 0;
 834 free_crypto:
 835         if (queue->hdr_digest || queue->data_digest)
 836                 nvmet_tcp_free_crypto(queue);
 837         return ret;
 838 }
 839
 840 static void nvmet_tcp_handle_req_failure(struct nvmet_tcp_queue *queue,
 841                 struct nvmet_tcp_cmd *cmd, struct nvmet_req *req)
 842 {
 843         size_t data_len = le32_to_cpu(req->cmd->common.dptr.sgl.length);
 844         int ret;
 845
 846         if (!nvme_is_write(cmd->req.cmd) ||
 847             data_len > cmd->req.port->inline_data_size) {
 848                 nvmet_prepare_receive_pdu(queue);
 849                 return;
 850         }
 851
 852         ret = nvmet_tcp_map_data(cmd);
 853         if (unlikely(ret)) {
 854                 pr_err("queue %d: failed to map data\n", queue->idx);
 855                 nvmet_tcp_fatal_error(queue);
 856                 return;
 857         }
 858
 859         queue->rcv_state = NVMET_TCP_RECV_DATA;
 860         nvmet_tcp_map_pdu_iovec(cmd);
 861         cmd->flags |= NVMET_TCP_F_INIT_FAILED;
 862 }
 863
 864 static int nvmet_tcp_handle_h2c_data_pdu(struct nvmet_tcp_queue *queue)
 865 {
 866         struct nvme_tcp_data_pdu *data = &queue->pdu.data;
 867         struct nvmet_tcp_cmd *cmd;
 868
 869         cmd = &queue->cmds[data->ttag];
 870
 871         if (le32_to_cpu(data->data_offset) != cmd->rbytes_done) {
 872                 pr_err("ttag %u unexpected data offset %u (expected %u)\n",
 873                         data->ttag, le32_to_cpu(data->data_offset),
 874                         cmd->rbytes_done);
 875                 /* FIXME: use path and transport errors */
 876                 nvmet_req_complete(&cmd->req,
 877                         NVME_SC_INVALID_FIELD | NVME_SC_DNR);
 878                 return -EPROTO;
 879         }
 880
 881         cmd->pdu_len = le32_to_cpu(data->data_length);
 882         cmd->pdu_recv = 0;
 883         nvmet_tcp_map_pdu_iovec(cmd);
 884         queue->cmd = cmd;
 885         queue->rcv_state = NVMET_TCP_RECV_DATA;
 886
 887         return 0;
 888 }
 889
 890 static int nvmet_tcp_done_recv_pdu(struct nvmet_tcp_queue *queue)
 891 {
 892         struct nvme_tcp_hdr *hdr = &queue->pdu.cmd.hdr;
 893         struct nvme_command *nvme_cmd = &queue->pdu.cmd.cmd;
 894         struct nvmet_req *req;
 895         int ret;
 896
 897         if (unlikely(queue->state == NVMET_TCP_Q_CONNECTING)) {
 898                 if (hdr->type != nvme_tcp_icreq) {
 899                         pr_err("unexpected pdu type (%d) before icreq\n",
 900                                 hdr->type);
 901                         nvmet_tcp_fatal_error(queue);
 902                         return -EPROTO;
 903                 }
 904                 return nvmet_tcp_handle_icreq(queue);
 905         }
 906
 907         if (hdr->type == nvme_tcp_h2c_data) {
 908                 ret = nvmet_tcp_handle_h2c_data_pdu(queue);
 909                 if (unlikely(ret))
 910                         return ret;
 911                 return 0;
 912         }
 913
 914         queue->cmd = nvmet_tcp_get_cmd(queue);
 915         if (unlikely(!queue->cmd)) {
 916                 /* This should never happen */
 917                 pr_err("queue %d: out of commands (%d) send_list_len: %d, opcode: %d",
 918                         queue->idx, queue->nr_cmds, queue->send_list_len,
 919                         nvme_cmd->common.opcode);
 920                 nvmet_tcp_fatal_error(queue);
 921                 return -ENOMEM;
 922         }
 923
 924         req = &queue->cmd->req;
 925         memcpy(req->cmd, nvme_cmd, sizeof(*nvme_cmd));
 926
 927         if (unlikely(!nvmet_req_init(req, &queue->nvme_cq,
 928                         &queue->nvme_sq, &nvmet_tcp_ops))) {
 929                 pr_err("failed cmd %p id %d opcode %d, data_len: %d\n",
 930                         req->cmd, req->cmd->common.command_id,
 931                         req->cmd->common.opcode,
 932                         le32_to_cpu(req->cmd->common.dptr.sgl.length));
 933
 934                 nvmet_tcp_handle_req_failure(queue, queue->cmd, req);
 935                 return -EAGAIN;
 936         }
 937
 938         ret = nvmet_tcp_map_data(queue->cmd);
 939         if (unlikely(ret)) {
 940                 pr_err("queue %d: failed to map data\n", queue->idx);
 941                 if (nvmet_tcp_has_inline_data(queue->cmd))
 942                         nvmet_tcp_fatal_error(queue);
 943                 else
 944                         nvmet_req_complete(req, ret);
 945                 ret = -EAGAIN;
 946                 goto out;
 947         }
 948
 949         if (nvmet_tcp_need_data_in(queue->cmd)) {
 950                 if (nvmet_tcp_has_inline_data(queue->cmd)) {
 951                         queue->rcv_state = NVMET_TCP_RECV_DATA;
 952                         nvmet_tcp_map_pdu_iovec(queue->cmd);
 953                         return 0;
 954                 }
 955                 /* send back R2T */
 956                 nvmet_tcp_queue_response(&queue->cmd->req);
 957                 goto out;
 958         }
 959
 960         queue->cmd->req.execute(&queue->cmd->req);
 961 out:
 962         nvmet_prepare_receive_pdu(queue);
 963         return ret;
 964 }
 965
 966 static const u8 nvme_tcp_pdu_sizes[] = {
 967         [nvme_tcp_icreq]        = sizeof(struct nvme_tcp_icreq_pdu),
 968         [nvme_tcp_cmd]          = sizeof(struct nvme_tcp_cmd_pdu),
 969         [nvme_tcp_h2c_data]     = sizeof(struct nvme_tcp_data_pdu),
 970 };
 971
 972 static inline u8 nvmet_tcp_pdu_size(u8 type)
 973 {
 974         size_t idx = type;
 975
 976         return (idx < ARRAY_SIZE(nvme_tcp_pdu_sizes) &&
 977                 nvme_tcp_pdu_sizes[idx]) ?
 978                         nvme_tcp_pdu_sizes[idx] : 0;
 979 }
 980
 981 static inline bool nvmet_tcp_pdu_valid(u8 type)
 982 {
 983         switch (type) {
 984         case nvme_tcp_icreq:
 985         case nvme_tcp_cmd:
 986         case nvme_tcp_h2c_data:
 987                 /* fallthru */
 988                 return true;
 989         }
 990
 991         return false;
 992 }
 993
 994 static int nvmet_tcp_try_recv_pdu(struct nvmet_tcp_queue *queue)
 995 {
 996         struct nvme_tcp_hdr *hdr = &queue->pdu.cmd.hdr;
 997         int len;
 998         struct kvec iov;
 999         struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
1000
1001 recv:
1002         iov.iov_base = (void *)&queue->pdu + queue->offset;
1003         iov.iov_len = queue->left;
1004         len = kernel_recvmsg(queue->sock, &msg, &iov, 1,
1005                         iov.iov_len, msg.msg_flags);
1006         if (unlikely(len < 0))
1007                 return len;
1008
1009         queue->offset += len;
1010         queue->left -= len;
1011         if (queue->left)
1012                 return -EAGAIN;
1013
1014         if (queue->offset == sizeof(struct nvme_tcp_hdr)) {
1015                 u8 hdgst = nvmet_tcp_hdgst_len(queue);
1016
1017                 if (unlikely(!nvmet_tcp_pdu_valid(hdr->type))) {
1018                         pr_err("unexpected pdu type %d\n", hdr->type);
1019                         nvmet_tcp_fatal_error(queue);
1020                         return -EIO;
1021                 }
1022
1023                 if (unlikely(hdr->hlen != nvmet_tcp_pdu_size(hdr->type))) {
1024                         pr_err("pdu %d bad hlen %d\n", hdr->type, hdr->hlen);
1025                         return -EIO;
1026                 }
1027
1028                 queue->left = hdr->hlen - queue->offset + hdgst;
1029                 goto recv;
1030         }
1031
1032         if (queue->hdr_digest &&
1033             nvmet_tcp_verify_hdgst(queue, &queue->pdu, queue->offset)) {
1034                 nvmet_tcp_fatal_error(queue); /* fatal */
1035                 return -EPROTO;
1036         }
1037
1038         if (queue->data_digest &&
1039             nvmet_tcp_check_ddgst(queue, &queue->pdu)) {
1040                 nvmet_tcp_fatal_error(queue); /* fatal */
1041                 return -EPROTO;
1042         }
1043
1044         return nvmet_tcp_done_recv_pdu(queue);
1045 }
1046
1047 static void nvmet_tcp_prep_recv_ddgst(struct nvmet_tcp_cmd *cmd)
1048 {
1049         struct nvmet_tcp_queue *queue = cmd->queue;
1050
1051         nvmet_tcp_ddgst(queue->rcv_hash, cmd);
1052         queue->offset = 0;
1053         queue->left = NVME_TCP_DIGEST_LENGTH;
1054         queue->rcv_state = NVMET_TCP_RECV_DDGST;
1055 }
1056
1057 static int nvmet_tcp_try_recv_data(struct nvmet_tcp_queue *queue)
1058 {
1059         struct nvmet_tcp_cmd  *cmd = queue->cmd;
1060         int ret;
1061
1062         while (msg_data_left(&cmd->recv_msg)) {
1063                 ret = sock_recvmsg(cmd->queue->sock, &cmd->recv_msg,
1064                         cmd->recv_msg.msg_flags);
1065                 if (ret <= 0)
1066                         return ret;
1067
1068                 cmd->pdu_recv += ret;
1069                 cmd->rbytes_done += ret;
1070         }
1071
1072         nvmet_tcp_unmap_pdu_iovec(cmd);
1073
1074         if (!(cmd->flags & NVMET_TCP_F_INIT_FAILED) &&
1075             cmd->rbytes_done == cmd->req.transfer_len) {
1076                 if (queue->data_digest) {
1077                         nvmet_tcp_prep_recv_ddgst(cmd);
1078                         return 0;
1079                 }
1080                 cmd->req.execute(&cmd->req);
1081         }
1082
1083         nvmet_prepare_receive_pdu(queue);
1084         return 0;
1085 }
1086
1087 static int nvmet_tcp_try_recv_ddgst(struct nvmet_tcp_queue *queue)
1088 {
1089         struct nvmet_tcp_cmd *cmd = queue->cmd;
1090         int ret;
1091         struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
1092         struct kvec iov = {
1093                 .iov_base = (void *)&cmd->recv_ddgst + queue->offset,
1094                 .iov_len = queue->left
1095         };
1096
1097         ret = kernel_recvmsg(queue->sock, &msg, &iov, 1,
1098                         iov.iov_len, msg.msg_flags);
1099         if (unlikely(ret < 0))
1100                 return ret;
1101
1102         queue->offset += ret;
1103         queue->left -= ret;
1104         if (queue->left)
1105                 return -EAGAIN;
1106
1107         if (queue->data_digest && cmd->exp_ddgst != cmd->recv_ddgst) {
1108                 pr_err("queue %d: cmd %d pdu (%d) data digest error: recv %#x expected %#x\n",
1109                         queue->idx, cmd->req.cmd->common.command_id,
1110                         queue->pdu.cmd.hdr.type, le32_to_cpu(cmd->recv_ddgst),
1111                         le32_to_cpu(cmd->exp_ddgst));
1112                 nvmet_tcp_finish_cmd(cmd);
1113                 nvmet_tcp_fatal_error(queue);
1114                 ret = -EPROTO;
1115                 goto out;
1116         }
1117
1118         if (!(cmd->flags & NVMET_TCP_F_INIT_FAILED) &&
1119             cmd->rbytes_done == cmd->req.transfer_len)
1120                 cmd->req.execute(&cmd->req);
1121         ret = 0;
1122 out:
1123         nvmet_prepare_receive_pdu(queue);
1124         return ret;
1125 }
1126
1127 static int nvmet_tcp_try_recv_one(struct nvmet_tcp_queue *queue)
1128 {
1129         int result = 0;
1130
1131         if (unlikely(queue->rcv_state == NVMET_TCP_RECV_ERR))
1132                 return 0;
1133
1134         if (queue->rcv_state == NVMET_TCP_RECV_PDU) {
1135                 result = nvmet_tcp_try_recv_pdu(queue);
1136                 if (result != 0)
1137                         goto done_recv;
1138         }
1139
1140         if (queue->rcv_state == NVMET_TCP_RECV_DATA) {
1141                 result = nvmet_tcp_try_recv_data(queue);
1142                 if (result != 0)
1143                         goto done_recv;
1144         }
1145
1146         if (queue->rcv_state == NVMET_TCP_RECV_DDGST) {
1147                 result = nvmet_tcp_try_recv_ddgst(queue);
1148                 if (result != 0)
1149                         goto done_recv;
1150         }
1151
1152 done_recv:
1153         if (result < 0) {
1154                 if (result == -EAGAIN)
1155                         return 0;
1156                 return result;
1157         }
1158         return 1;
1159 }
1160
1161 static int nvmet_tcp_try_recv(struct nvmet_tcp_queue *queue,
1162                 int budget, int *recvs)
1163 {
1164         int i, ret = 0;
1165
1166         for (i = 0; i < budget; i++) {
1167                 ret = nvmet_tcp_try_recv_one(queue);
1168                 if (unlikely(ret < 0)) {
1169                         nvmet_tcp_socket_error(queue, ret);
1170                         goto done;
1171                 } else if (ret == 0) {
1172                         break;
1173                 }
1174                 (*recvs)++;
1175         }
1176 done:
1177         return ret;
1178 }
1179
1180 static void nvmet_tcp_schedule_release_queue(struct nvmet_tcp_queue *queue)
1181 {
1182         spin_lock(&queue->state_lock);
1183         if (queue->state != NVMET_TCP_Q_DISCONNECTING) {
1184                 queue->state = NVMET_TCP_Q_DISCONNECTING;
1185                 schedule_work(&queue->release_work);
1186         }
1187         spin_unlock(&queue->state_lock);
1188 }
1189
1190 static void nvmet_tcp_io_work(struct work_struct *w)
1191 {
1192         struct nvmet_tcp_queue *queue =
1193                 container_of(w, struct nvmet_tcp_queue, io_work);
1194         bool pending;
1195         int ret, ops = 0;
1196
1197         do {
1198                 pending = false;
1199
1200                 ret = nvmet_tcp_try_recv(queue, NVMET_TCP_RECV_BUDGET, &ops);
1201                 if (ret > 0)
1202                         pending = true;
1203                 else if (ret < 0)
1204                         return;
1205
1206                 ret = nvmet_tcp_try_send(queue, NVMET_TCP_SEND_BUDGET, &ops);
1207                 if (ret > 0)
1208                         pending = true;
1209                 else if (ret < 0)
1210                         return;
1211
1212         } while (pending && ops < NVMET_TCP_IO_WORK_BUDGET);
1213
1214         /*
1215          * We exahusted our budget, requeue our selves
1216          */
1217         if (pending)
1218                 queue_work_on(queue->cpu, nvmet_tcp_wq, &queue->io_work);
1219 }
1220
1221 static int nvmet_tcp_alloc_cmd(struct nvmet_tcp_queue *queue,
1222                 struct nvmet_tcp_cmd *c)
1223 {
1224         u8 hdgst = nvmet_tcp_hdgst_len(queue);
1225
1226         c->queue = queue;
1227         c->req.port = queue->port->nport;
1228
1229         c->cmd_pdu = page_frag_alloc(&queue->pf_cache,
1230                         sizeof(*c->cmd_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1231         if (!c->cmd_pdu)
1232                 return -ENOMEM;
1233         c->req.cmd = &c->cmd_pdu->cmd;
1234
1235         c->rsp_pdu = page_frag_alloc(&queue->pf_cache,
1236                         sizeof(*c->rsp_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1237         if (!c->rsp_pdu)
1238                 goto out_free_cmd;
1239         c->req.cqe = &c->rsp_pdu->cqe;
1240
1241         c->data_pdu = page_frag_alloc(&queue->pf_cache,
1242                         sizeof(*c->data_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1243         if (!c->data_pdu)
1244                 goto out_free_rsp;
1245
1246         c->r2t_pdu = page_frag_alloc(&queue->pf_cache,
1247                         sizeof(*c->r2t_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1248         if (!c->r2t_pdu)
1249                 goto out_free_data;
1250
1251         c->recv_msg.msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
1252
1253         list_add_tail(&c->entry, &queue->free_list);
1254
1255         return 0;
1256 out_free_data:
1257         page_frag_free(c->data_pdu);
1258 out_free_rsp:
1259         page_frag_free(c->rsp_pdu);
1260 out_free_cmd:
1261         page_frag_free(c->cmd_pdu);
1262         return -ENOMEM;
1263 }
1264
1265 static void nvmet_tcp_free_cmd(struct nvmet_tcp_cmd *c)
1266 {
1267         page_frag_free(c->r2t_pdu);
1268         page_frag_free(c->data_pdu);
1269         page_frag_free(c->rsp_pdu);
1270         page_frag_free(c->cmd_pdu);
1271 }
1272
1273 static int nvmet_tcp_alloc_cmds(struct nvmet_tcp_queue *queue)
1274 {
1275         struct nvmet_tcp_cmd *cmds;
1276         int i, ret = -EINVAL, nr_cmds = queue->nr_cmds;
1277
1278         cmds = kcalloc(nr_cmds, sizeof(struct nvmet_tcp_cmd), GFP_KERNEL);
1279         if (!cmds)
1280                 goto out;
1281
1282         for (i = 0; i < nr_cmds; i++) {
1283                 ret = nvmet_tcp_alloc_cmd(queue, cmds + i);
1284                 if (ret)
1285                         goto out_free;
1286         }
1287
1288         queue->cmds = cmds;
1289
1290         return 0;
1291 out_free:
1292         while (--i >= 0)
1293                 nvmet_tcp_free_cmd(cmds + i);
1294         kfree(cmds);
1295 out:
1296         return ret;
1297 }
1298
1299 static void nvmet_tcp_free_cmds(struct nvmet_tcp_queue *queue)
1300 {
1301         struct nvmet_tcp_cmd *cmds = queue->cmds;
1302         int i;
1303
1304         for (i = 0; i < queue->nr_cmds; i++)
1305                 nvmet_tcp_free_cmd(cmds + i);
1306
1307         nvmet_tcp_free_cmd(&queue->connect);
1308         kfree(cmds);
1309 }
1310
1311 static void nvmet_tcp_restore_socket_callbacks(struct nvmet_tcp_queue *queue)
1312 {
1313         struct socket *sock = queue->sock;
1314
1315         write_lock_bh(&sock->sk->sk_callback_lock);
1316         sock->sk->sk_data_ready =  queue->data_ready;
1317         sock->sk->sk_state_change = queue->state_change;
1318         sock->sk->sk_write_space = queue->write_space;
1319         sock->sk->sk_user_data = NULL;
1320         write_unlock_bh(&sock->sk->sk_callback_lock);
1321 }
1322
1323 static void nvmet_tcp_finish_cmd(struct nvmet_tcp_cmd *cmd)
1324 {
1325         nvmet_req_uninit(&cmd->req);
1326         nvmet_tcp_unmap_pdu_iovec(cmd);
1327         kfree(cmd->iov);
1328         sgl_free(cmd->req.sg);
1329 }
1330
1331 static void nvmet_tcp_uninit_data_in_cmds(struct nvmet_tcp_queue *queue)
1332 {
1333         struct nvmet_tcp_cmd *cmd = queue->cmds;
1334         int i;
1335
1336         for (i = 0; i < queue->nr_cmds; i++, cmd++) {
1337                 if (nvmet_tcp_need_data_in(cmd))
1338                         nvmet_tcp_finish_cmd(cmd);
1339         }
1340
1341         if (!queue->nr_cmds && nvmet_tcp_need_data_in(&queue->connect)) {
1342                 /* failed in connect */
1343                 nvmet_tcp_finish_cmd(&queue->connect);
1344         }
1345 }
1346
1347 static void nvmet_tcp_release_queue_work(struct work_struct *w)
1348 {
1349         struct nvmet_tcp_queue *queue =
1350                 container_of(w, struct nvmet_tcp_queue, release_work);
1351
1352         mutex_lock(&nvmet_tcp_queue_mutex);
1353         list_del_init(&queue->queue_list);
1354         mutex_unlock(&nvmet_tcp_queue_mutex);
1355
1356         nvmet_tcp_restore_socket_callbacks(queue);
1357         flush_work(&queue->io_work);
1358
1359         nvmet_tcp_uninit_data_in_cmds(queue);
1360         nvmet_sq_destroy(&queue->nvme_sq);
1361         cancel_work_sync(&queue->io_work);
1362         sock_release(queue->sock);
1363         nvmet_tcp_free_cmds(queue);
1364         if (queue->hdr_digest || queue->data_digest)
1365                 nvmet_tcp_free_crypto(queue);
1366         ida_simple_remove(&nvmet_tcp_queue_ida, queue->idx);
1367
1368         kfree(queue);
1369 }
1370
1371 static void nvmet_tcp_data_ready(struct sock *sk)
1372 {
1373         struct nvmet_tcp_queue *queue;
1374
1375         read_lock_bh(&sk->sk_callback_lock);
1376         queue = sk->sk_user_data;
1377         if (likely(queue))
1378                 queue_work_on(queue->cpu, nvmet_tcp_wq, &queue->io_work);
1379         read_unlock_bh(&sk->sk_callback_lock);
1380 }
1381
1382 static void nvmet_tcp_write_space(struct sock *sk)
1383 {
1384         struct nvmet_tcp_queue *queue;
1385
1386         read_lock_bh(&sk->sk_callback_lock);
1387         queue = sk->sk_user_data;
1388         if (unlikely(!queue))
1389                 goto out;
1390
1391         if (unlikely(queue->state == NVMET_TCP_Q_CONNECTING)) {
1392                 queue->write_space(sk);
1393                 goto out;
1394         }
1395
1396         if (sk_stream_is_writeable(sk)) {
1397                 clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1398                 queue_work_on(queue->cpu, nvmet_tcp_wq, &queue->io_work);
1399         }
1400 out:
1401         read_unlock_bh(&sk->sk_callback_lock);
1402 }
1403
1404 static void nvmet_tcp_state_change(struct sock *sk)
1405 {
1406         struct nvmet_tcp_queue *queue;
1407
1408         write_lock_bh(&sk->sk_callback_lock);
1409         queue = sk->sk_user_data;
1410         if (!queue)
1411                 goto done;
1412
1413         switch (sk->sk_state) {
1414         case TCP_FIN_WAIT1:
1415         case TCP_CLOSE_WAIT:
1416         case TCP_CLOSE:
1417                 /* FALLTHRU */
1418                 sk->sk_user_data = NULL;
1419                 nvmet_tcp_schedule_release_queue(queue);
1420                 break;
1421         default:
1422                 pr_warn("queue %d unhandled state %d\n",
1423                         queue->idx, sk->sk_state);
1424         }
1425 done:
1426         write_unlock_bh(&sk->sk_callback_lock);
1427 }
1428
1429 static int nvmet_tcp_set_queue_sock(struct nvmet_tcp_queue *queue)
1430 {
1431         struct socket *sock = queue->sock;
1432         struct inet_sock *inet = inet_sk(sock->sk);
1433         int ret;
1434
1435         ret = kernel_getsockname(sock,
1436                 (struct sockaddr *)&queue->sockaddr);
1437         if (ret < 0)
1438                 return ret;
1439
1440         ret = kernel_getpeername(sock,
1441                 (struct sockaddr *)&queue->sockaddr_peer);
1442         if (ret < 0)
1443                 return ret;
1444
1445         /*
1446          * Cleanup whatever is sitting in the TCP transmit queue on socket
1447          * close. This is done to prevent stale data from being sent should
1448          * the network connection be restored before TCP times out.
1449          */
1450         sock_no_linger(sock->sk);
1451
1452         if (so_priority > 0)
1453                 sock_set_priority(sock->sk, so_priority);
1454
1455         /* Set socket type of service */
1456         if (inet->rcv_tos > 0)
1457                 ip_sock_set_tos(sock->sk, inet->rcv_tos);
1458
1459         write_lock_bh(&sock->sk->sk_callback_lock);
1460         sock->sk->sk_user_data = queue;
1461         queue->data_ready = sock->sk->sk_data_ready;
1462         sock->sk->sk_data_ready = nvmet_tcp_data_ready;
1463         queue->state_change = sock->sk->sk_state_change;
1464         sock->sk->sk_state_change = nvmet_tcp_state_change;
1465         queue->write_space = sock->sk->sk_write_space;
1466         sock->sk->sk_write_space = nvmet_tcp_write_space;
1467         write_unlock_bh(&sock->sk->sk_callback_lock);
1468
1469         return 0;
1470 }
1471
1472 static int nvmet_tcp_alloc_queue(struct nvmet_tcp_port *port,
1473                 struct socket *newsock)
1474 {
1475         struct nvmet_tcp_queue *queue;
1476         int ret;
1477
1478         queue = kzalloc(sizeof(*queue), GFP_KERNEL);
1479         if (!queue)
1480                 return -ENOMEM;
1481
1482         INIT_WORK(&queue->release_work, nvmet_tcp_release_queue_work);
1483         INIT_WORK(&queue->io_work, nvmet_tcp_io_work);
1484         queue->sock = newsock;
1485         queue->port = port;
1486         queue->nr_cmds = 0;
1487         spin_lock_init(&queue->state_lock);
1488         queue->state = NVMET_TCP_Q_CONNECTING;
1489         INIT_LIST_HEAD(&queue->free_list);
1490         init_llist_head(&queue->resp_list);
1491         INIT_LIST_HEAD(&queue->resp_send_list);
1492
1493         queue->idx = ida_simple_get(&nvmet_tcp_queue_ida, 0, 0, GFP_KERNEL);
1494         if (queue->idx < 0) {
1495                 ret = queue->idx;
1496                 goto out_free_queue;
1497         }
1498
1499         ret = nvmet_tcp_alloc_cmd(queue, &queue->connect);
1500         if (ret)
1501                 goto out_ida_remove;
1502
1503         ret = nvmet_sq_init(&queue->nvme_sq);
1504         if (ret)
1505                 goto out_free_connect;
1506
1507         port->last_cpu = cpumask_next_wrap(port->last_cpu,
1508                                 cpu_online_mask, -1, false);
1509         queue->cpu = port->last_cpu;
1510         nvmet_prepare_receive_pdu(queue);
1511
1512         mutex_lock(&nvmet_tcp_queue_mutex);
1513         list_add_tail(&queue->queue_list, &nvmet_tcp_queue_list);
1514         mutex_unlock(&nvmet_tcp_queue_mutex);
1515
1516         ret = nvmet_tcp_set_queue_sock(queue);
1517         if (ret)
1518                 goto out_destroy_sq;
1519
1520         queue_work_on(queue->cpu, nvmet_tcp_wq, &queue->io_work);
1521
1522         return 0;
1523 out_destroy_sq:
1524         mutex_lock(&nvmet_tcp_queue_mutex);
1525         list_del_init(&queue->queue_list);
1526         mutex_unlock(&nvmet_tcp_queue_mutex);
1527         nvmet_sq_destroy(&queue->nvme_sq);
1528 out_free_connect:
1529         nvmet_tcp_free_cmd(&queue->connect);
1530 out_ida_remove:
1531         ida_simple_remove(&nvmet_tcp_queue_ida, queue->idx);
1532 out_free_queue:
1533         kfree(queue);
1534         return ret;
1535 }
1536
1537 static void nvmet_tcp_accept_work(struct work_struct *w)
1538 {
1539         struct nvmet_tcp_port *port =
1540                 container_of(w, struct nvmet_tcp_port, accept_work);
1541         struct socket *newsock;
1542         int ret;
1543
1544         while (true) {
1545                 ret = kernel_accept(port->sock, &newsock, O_NONBLOCK);
1546                 if (ret < 0) {
1547                         if (ret != -EAGAIN)
1548                                 pr_warn("failed to accept err=%d\n", ret);
1549                         return;
1550                 }
1551                 ret = nvmet_tcp_alloc_queue(port, newsock);
1552                 if (ret) {
1553                         pr_err("failed to allocate queue\n");
1554                         sock_release(newsock);
1555                 }
1556         }
1557 }
1558
1559 static void nvmet_tcp_listen_data_ready(struct sock *sk)
1560 {
1561         struct nvmet_tcp_port *port;
1562
1563         read_lock_bh(&sk->sk_callback_lock);
1564         port = sk->sk_user_data;
1565         if (!port)
1566                 goto out;
1567
1568         if (sk->sk_state == TCP_LISTEN)
1569                 schedule_work(&port->accept_work);
1570 out:
1571         read_unlock_bh(&sk->sk_callback_lock);
1572 }
1573
1574 static int nvmet_tcp_add_port(struct nvmet_port *nport)
1575 {
1576         struct nvmet_tcp_port *port;
1577         __kernel_sa_family_t af;
1578         int ret;
1579
1580         port = kzalloc(sizeof(*port), GFP_KERNEL);
1581         if (!port)
1582                 return -ENOMEM;
1583
1584         switch (nport->disc_addr.adrfam) {
1585         case NVMF_ADDR_FAMILY_IP4:
1586                 af = AF_INET;
1587                 break;
1588         case NVMF_ADDR_FAMILY_IP6:
1589                 af = AF_INET6;
1590                 break;
1591         default:
1592                 pr_err("address family %d not supported\n",
1593                                 nport->disc_addr.adrfam);
1594                 ret = -EINVAL;
1595                 goto err_port;
1596         }
1597
1598         ret = inet_pton_with_scope(&init_net, af, nport->disc_addr.traddr,
1599                         nport->disc_addr.trsvcid, &port->addr);
1600         if (ret) {
1601                 pr_err("malformed ip/port passed: %s:%s\n",
1602                         nport->disc_addr.traddr, nport->disc_addr.trsvcid);
1603                 goto err_port;
1604         }
1605
1606         port->nport = nport;
1607         port->last_cpu = -1;
1608         INIT_WORK(&port->accept_work, nvmet_tcp_accept_work);
1609         if (port->nport->inline_data_size < 0)
1610                 port->nport->inline_data_size = NVMET_TCP_DEF_INLINE_DATA_SIZE;
1611
1612         ret = sock_create(port->addr.ss_family, SOCK_STREAM,
1613                                 IPPROTO_TCP, &port->sock);
1614         if (ret) {
1615                 pr_err("failed to create a socket\n");
1616                 goto err_port;
1617         }
1618
1619         port->sock->sk->sk_user_data = port;
1620         port->data_ready = port->sock->sk->sk_data_ready;
1621         port->sock->sk->sk_data_ready = nvmet_tcp_listen_data_ready;
1622         sock_set_reuseaddr(port->sock->sk);
1623         tcp_sock_set_nodelay(port->sock->sk);
1624         if (so_priority > 0)
1625                 sock_set_priority(port->sock->sk, so_priority);
1626
1627         ret = kernel_bind(port->sock, (struct sockaddr *)&port->addr,
1628                         sizeof(port->addr));
1629         if (ret) {
1630                 pr_err("failed to bind port socket %d\n", ret);
1631                 goto err_sock;
1632         }
1633
1634         ret = kernel_listen(port->sock, 128);
1635         if (ret) {
1636                 pr_err("failed to listen %d on port sock\n", ret);
1637                 goto err_sock;
1638         }
1639
1640         nport->priv = port;
1641         pr_info("enabling port %d (%pISpc)\n",
1642                 le16_to_cpu(nport->disc_addr.portid), &port->addr);
1643
1644         return 0;
1645
1646 err_sock:
1647         sock_release(port->sock);
1648 err_port:
1649         kfree(port);
1650         return ret;
1651 }
1652
1653 static void nvmet_tcp_remove_port(struct nvmet_port *nport)
1654 {
1655         struct nvmet_tcp_port *port = nport->priv;
1656
1657         write_lock_bh(&port->sock->sk->sk_callback_lock);
1658         port->sock->sk->sk_data_ready = port->data_ready;
1659         port->sock->sk->sk_user_data = NULL;
1660         write_unlock_bh(&port->sock->sk->sk_callback_lock);
1661         cancel_work_sync(&port->accept_work);
1662
1663         sock_release(port->sock);
1664         kfree(port);
1665 }
1666
1667 static void nvmet_tcp_delete_ctrl(struct nvmet_ctrl *ctrl)
1668 {
1669         struct nvmet_tcp_queue *queue;
1670
1671         mutex_lock(&nvmet_tcp_queue_mutex);
1672         list_for_each_entry(queue, &nvmet_tcp_queue_list, queue_list)
1673                 if (queue->nvme_sq.ctrl == ctrl)
1674                         kernel_sock_shutdown(queue->sock, SHUT_RDWR);
1675         mutex_unlock(&nvmet_tcp_queue_mutex);
1676 }
1677
1678 static u16 nvmet_tcp_install_queue(struct nvmet_sq *sq)
1679 {
1680         struct nvmet_tcp_queue *queue =
1681                 container_of(sq, struct nvmet_tcp_queue, nvme_sq);
1682
1683         if (sq->qid == 0) {
1684                 /* Let inflight controller teardown complete */
1685                 flush_scheduled_work();
1686         }
1687
1688         queue->nr_cmds = sq->size * 2;
1689         if (nvmet_tcp_alloc_cmds(queue))
1690                 return NVME_SC_INTERNAL;
1691         return 0;
1692 }
1693
1694 static void nvmet_tcp_disc_port_addr(struct nvmet_req *req,
1695                 struct nvmet_port *nport, char *traddr)
1696 {
1697         struct nvmet_tcp_port *port = nport->priv;
1698
1699         if (inet_addr_is_any((struct sockaddr *)&port->addr)) {
1700                 struct nvmet_tcp_cmd *cmd =
1701                         container_of(req, struct nvmet_tcp_cmd, req);
1702                 struct nvmet_tcp_queue *queue = cmd->queue;
1703
1704                 sprintf(traddr, "%pISc", (struct sockaddr *)&queue->sockaddr);
1705         } else {
1706                 memcpy(traddr, nport->disc_addr.traddr, NVMF_TRADDR_SIZE);
1707         }
1708 }
1709
1710 static const struct nvmet_fabrics_ops nvmet_tcp_ops = {
1711         .owner                  = THIS_MODULE,
1712         .type                   = NVMF_TRTYPE_TCP,
1713         .msdbd                  = 1,
1714         .add_port               = nvmet_tcp_add_port,
1715         .remove_port            = nvmet_tcp_remove_port,
1716         .queue_response         = nvmet_tcp_queue_response,
1717         .delete_ctrl            = nvmet_tcp_delete_ctrl,
1718         .install_queue          = nvmet_tcp_install_queue,
1719         .disc_traddr            = nvmet_tcp_disc_port_addr,
1720 };
1721
1722 static int __init nvmet_tcp_init(void)
1723 {
1724         int ret;
1725
1726         nvmet_tcp_wq = alloc_workqueue("nvmet_tcp_wq", WQ_HIGHPRI, 0);
1727         if (!nvmet_tcp_wq)
1728                 return -ENOMEM;
1729
1730         ret = nvmet_register_transport(&nvmet_tcp_ops);
1731         if (ret)
1732                 goto err;
1733
1734         return 0;
1735 err:
1736         destroy_workqueue(nvmet_tcp_wq);
1737         return ret;
1738 }
1739
1740 static void __exit nvmet_tcp_exit(void)
1741 {
1742         struct nvmet_tcp_queue *queue;
1743
1744         nvmet_unregister_transport(&nvmet_tcp_ops);
1745
1746         flush_scheduled_work();
1747         mutex_lock(&nvmet_tcp_queue_mutex);
1748         list_for_each_entry(queue, &nvmet_tcp_queue_list, queue_list)
1749                 kernel_sock_shutdown(queue->sock, SHUT_RDWR);
1750         mutex_unlock(&nvmet_tcp_queue_mutex);
1751         flush_scheduled_work();
1752
1753         destroy_workqueue(nvmet_tcp_wq);
1754 }
1755
1756 module_init(nvmet_tcp_init);
1757 module_exit(nvmet_tcp_exit);
1758
1759 MODULE_LICENSE("GPL v2");
1760 MODULE_ALIAS("nvmet-transport-3"); /* 3 == NVMF_TRTYPE_TCP */