xref: /openbmc/linux/drivers/nvme/target/tcp.c (revision 4df933252827af69cb087e3df1294e4945a6f6c6)
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 (!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, bool last_in_batch)
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 		int flags = MSG_DONTWAIT;
527 
528 		if ((!last_in_batch && cmd->queue->send_list_len) ||
529 		    cmd->wbytes_done + left < cmd->req.transfer_len ||
530 		    queue->data_digest || !queue->nvme_sq.sqhd_disabled)
531 			flags |= MSG_MORE;
532 
533 		ret = kernel_sendpage(cmd->queue->sock, page, cmd->offset,
534 					left, flags);
535 		if (ret <= 0)
536 			return ret;
537 
538 		cmd->offset += ret;
539 		cmd->wbytes_done += ret;
540 
541 		/* Done with sg?*/
542 		if (cmd->offset == cmd->cur_sg->length) {
543 			cmd->cur_sg = sg_next(cmd->cur_sg);
544 			cmd->offset = 0;
545 		}
546 	}
547 
548 	if (queue->data_digest) {
549 		cmd->state = NVMET_TCP_SEND_DDGST;
550 		cmd->offset = 0;
551 	} else {
552 		if (queue->nvme_sq.sqhd_disabled) {
553 			cmd->queue->snd_cmd = NULL;
554 			nvmet_tcp_put_cmd(cmd);
555 		} else {
556 			nvmet_setup_response_pdu(cmd);
557 		}
558 	}
559 
560 	if (queue->nvme_sq.sqhd_disabled) {
561 		kfree(cmd->iov);
562 		sgl_free(cmd->req.sg);
563 	}
564 
565 	return 1;
566 
567 }
568 
569 static int nvmet_try_send_response(struct nvmet_tcp_cmd *cmd,
570 		bool last_in_batch)
571 {
572 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
573 	int left = sizeof(*cmd->rsp_pdu) - cmd->offset + hdgst;
574 	int flags = MSG_DONTWAIT;
575 	int ret;
576 
577 	if (!last_in_batch && cmd->queue->send_list_len)
578 		flags |= MSG_MORE;
579 	else
580 		flags |= MSG_EOR;
581 
582 	ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->rsp_pdu),
583 		offset_in_page(cmd->rsp_pdu) + cmd->offset, left, flags);
584 	if (ret <= 0)
585 		return ret;
586 	cmd->offset += ret;
587 	left -= ret;
588 
589 	if (left)
590 		return -EAGAIN;
591 
592 	kfree(cmd->iov);
593 	sgl_free(cmd->req.sg);
594 	cmd->queue->snd_cmd = NULL;
595 	nvmet_tcp_put_cmd(cmd);
596 	return 1;
597 }
598 
599 static int nvmet_try_send_r2t(struct nvmet_tcp_cmd *cmd, bool last_in_batch)
600 {
601 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
602 	int left = sizeof(*cmd->r2t_pdu) - cmd->offset + hdgst;
603 	int flags = MSG_DONTWAIT;
604 	int ret;
605 
606 	if (!last_in_batch && cmd->queue->send_list_len)
607 		flags |= MSG_MORE;
608 	else
609 		flags |= MSG_EOR;
610 
611 	ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->r2t_pdu),
612 		offset_in_page(cmd->r2t_pdu) + cmd->offset, left, flags);
613 	if (ret <= 0)
614 		return ret;
615 	cmd->offset += ret;
616 	left -= ret;
617 
618 	if (left)
619 		return -EAGAIN;
620 
621 	cmd->queue->snd_cmd = NULL;
622 	return 1;
623 }
624 
625 static int nvmet_try_send_ddgst(struct nvmet_tcp_cmd *cmd)
626 {
627 	struct nvmet_tcp_queue *queue = cmd->queue;
628 	struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
629 	struct kvec iov = {
630 		.iov_base = &cmd->exp_ddgst + cmd->offset,
631 		.iov_len = NVME_TCP_DIGEST_LENGTH - cmd->offset
632 	};
633 	int ret;
634 
635 	ret = kernel_sendmsg(queue->sock, &msg, &iov, 1, iov.iov_len);
636 	if (unlikely(ret <= 0))
637 		return ret;
638 
639 	cmd->offset += ret;
640 
641 	if (queue->nvme_sq.sqhd_disabled) {
642 		cmd->queue->snd_cmd = NULL;
643 		nvmet_tcp_put_cmd(cmd);
644 	} else {
645 		nvmet_setup_response_pdu(cmd);
646 	}
647 	return 1;
648 }
649 
650 static int nvmet_tcp_try_send_one(struct nvmet_tcp_queue *queue,
651 		bool last_in_batch)
652 {
653 	struct nvmet_tcp_cmd *cmd = queue->snd_cmd;
654 	int ret = 0;
655 
656 	if (!cmd || queue->state == NVMET_TCP_Q_DISCONNECTING) {
657 		cmd = nvmet_tcp_fetch_cmd(queue);
658 		if (unlikely(!cmd))
659 			return 0;
660 	}
661 
662 	if (cmd->state == NVMET_TCP_SEND_DATA_PDU) {
663 		ret = nvmet_try_send_data_pdu(cmd);
664 		if (ret <= 0)
665 			goto done_send;
666 	}
667 
668 	if (cmd->state == NVMET_TCP_SEND_DATA) {
669 		ret = nvmet_try_send_data(cmd, last_in_batch);
670 		if (ret <= 0)
671 			goto done_send;
672 	}
673 
674 	if (cmd->state == NVMET_TCP_SEND_DDGST) {
675 		ret = nvmet_try_send_ddgst(cmd);
676 		if (ret <= 0)
677 			goto done_send;
678 	}
679 
680 	if (cmd->state == NVMET_TCP_SEND_R2T) {
681 		ret = nvmet_try_send_r2t(cmd, last_in_batch);
682 		if (ret <= 0)
683 			goto done_send;
684 	}
685 
686 	if (cmd->state == NVMET_TCP_SEND_RESPONSE)
687 		ret = nvmet_try_send_response(cmd, last_in_batch);
688 
689 done_send:
690 	if (ret < 0) {
691 		if (ret == -EAGAIN)
692 			return 0;
693 		return ret;
694 	}
695 
696 	return 1;
697 }
698 
699 static int nvmet_tcp_try_send(struct nvmet_tcp_queue *queue,
700 		int budget, int *sends)
701 {
702 	int i, ret = 0;
703 
704 	for (i = 0; i < budget; i++) {
705 		ret = nvmet_tcp_try_send_one(queue, i == budget - 1);
706 		if (ret <= 0)
707 			break;
708 		(*sends)++;
709 	}
710 
711 	return ret;
712 }
713 
714 static void nvmet_prepare_receive_pdu(struct nvmet_tcp_queue *queue)
715 {
716 	queue->offset = 0;
717 	queue->left = sizeof(struct nvme_tcp_hdr);
718 	queue->cmd = NULL;
719 	queue->rcv_state = NVMET_TCP_RECV_PDU;
720 }
721 
722 static void nvmet_tcp_free_crypto(struct nvmet_tcp_queue *queue)
723 {
724 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(queue->rcv_hash);
725 
726 	ahash_request_free(queue->rcv_hash);
727 	ahash_request_free(queue->snd_hash);
728 	crypto_free_ahash(tfm);
729 }
730 
731 static int nvmet_tcp_alloc_crypto(struct nvmet_tcp_queue *queue)
732 {
733 	struct crypto_ahash *tfm;
734 
735 	tfm = crypto_alloc_ahash("crc32c", 0, CRYPTO_ALG_ASYNC);
736 	if (IS_ERR(tfm))
737 		return PTR_ERR(tfm);
738 
739 	queue->snd_hash = ahash_request_alloc(tfm, GFP_KERNEL);
740 	if (!queue->snd_hash)
741 		goto free_tfm;
742 	ahash_request_set_callback(queue->snd_hash, 0, NULL, NULL);
743 
744 	queue->rcv_hash = ahash_request_alloc(tfm, GFP_KERNEL);
745 	if (!queue->rcv_hash)
746 		goto free_snd_hash;
747 	ahash_request_set_callback(queue->rcv_hash, 0, NULL, NULL);
748 
749 	return 0;
750 free_snd_hash:
751 	ahash_request_free(queue->snd_hash);
752 free_tfm:
753 	crypto_free_ahash(tfm);
754 	return -ENOMEM;
755 }
756 
757 
758 static int nvmet_tcp_handle_icreq(struct nvmet_tcp_queue *queue)
759 {
760 	struct nvme_tcp_icreq_pdu *icreq = &queue->pdu.icreq;
761 	struct nvme_tcp_icresp_pdu *icresp = &queue->pdu.icresp;
762 	struct msghdr msg = {};
763 	struct kvec iov;
764 	int ret;
765 
766 	if (le32_to_cpu(icreq->hdr.plen) != sizeof(struct nvme_tcp_icreq_pdu)) {
767 		pr_err("bad nvme-tcp pdu length (%d)\n",
768 			le32_to_cpu(icreq->hdr.plen));
769 		nvmet_tcp_fatal_error(queue);
770 	}
771 
772 	if (icreq->pfv != NVME_TCP_PFV_1_0) {
773 		pr_err("queue %d: bad pfv %d\n", queue->idx, icreq->pfv);
774 		return -EPROTO;
775 	}
776 
777 	if (icreq->hpda != 0) {
778 		pr_err("queue %d: unsupported hpda %d\n", queue->idx,
779 			icreq->hpda);
780 		return -EPROTO;
781 	}
782 
783 	queue->hdr_digest = !!(icreq->digest & NVME_TCP_HDR_DIGEST_ENABLE);
784 	queue->data_digest = !!(icreq->digest & NVME_TCP_DATA_DIGEST_ENABLE);
785 	if (queue->hdr_digest || queue->data_digest) {
786 		ret = nvmet_tcp_alloc_crypto(queue);
787 		if (ret)
788 			return ret;
789 	}
790 
791 	memset(icresp, 0, sizeof(*icresp));
792 	icresp->hdr.type = nvme_tcp_icresp;
793 	icresp->hdr.hlen = sizeof(*icresp);
794 	icresp->hdr.pdo = 0;
795 	icresp->hdr.plen = cpu_to_le32(icresp->hdr.hlen);
796 	icresp->pfv = cpu_to_le16(NVME_TCP_PFV_1_0);
797 	icresp->maxdata = cpu_to_le32(0xffff); /* FIXME: support r2t */
798 	icresp->cpda = 0;
799 	if (queue->hdr_digest)
800 		icresp->digest |= NVME_TCP_HDR_DIGEST_ENABLE;
801 	if (queue->data_digest)
802 		icresp->digest |= NVME_TCP_DATA_DIGEST_ENABLE;
803 
804 	iov.iov_base = icresp;
805 	iov.iov_len = sizeof(*icresp);
806 	ret = kernel_sendmsg(queue->sock, &msg, &iov, 1, iov.iov_len);
807 	if (ret < 0)
808 		goto free_crypto;
809 
810 	queue->state = NVMET_TCP_Q_LIVE;
811 	nvmet_prepare_receive_pdu(queue);
812 	return 0;
813 free_crypto:
814 	if (queue->hdr_digest || queue->data_digest)
815 		nvmet_tcp_free_crypto(queue);
816 	return ret;
817 }
818 
819 static void nvmet_tcp_handle_req_failure(struct nvmet_tcp_queue *queue,
820 		struct nvmet_tcp_cmd *cmd, struct nvmet_req *req)
821 {
822 	size_t data_len = le32_to_cpu(req->cmd->common.dptr.sgl.length);
823 	int ret;
824 
825 	if (!nvme_is_write(cmd->req.cmd) ||
826 	    data_len > cmd->req.port->inline_data_size) {
827 		nvmet_prepare_receive_pdu(queue);
828 		return;
829 	}
830 
831 	ret = nvmet_tcp_map_data(cmd);
832 	if (unlikely(ret)) {
833 		pr_err("queue %d: failed to map data\n", queue->idx);
834 		nvmet_tcp_fatal_error(queue);
835 		return;
836 	}
837 
838 	queue->rcv_state = NVMET_TCP_RECV_DATA;
839 	nvmet_tcp_map_pdu_iovec(cmd);
840 	cmd->flags |= NVMET_TCP_F_INIT_FAILED;
841 }
842 
843 static int nvmet_tcp_handle_h2c_data_pdu(struct nvmet_tcp_queue *queue)
844 {
845 	struct nvme_tcp_data_pdu *data = &queue->pdu.data;
846 	struct nvmet_tcp_cmd *cmd;
847 
848 	cmd = &queue->cmds[data->ttag];
849 
850 	if (le32_to_cpu(data->data_offset) != cmd->rbytes_done) {
851 		pr_err("ttag %u unexpected data offset %u (expected %u)\n",
852 			data->ttag, le32_to_cpu(data->data_offset),
853 			cmd->rbytes_done);
854 		/* FIXME: use path and transport errors */
855 		nvmet_req_complete(&cmd->req,
856 			NVME_SC_INVALID_FIELD | NVME_SC_DNR);
857 		return -EPROTO;
858 	}
859 
860 	cmd->pdu_len = le32_to_cpu(data->data_length);
861 	cmd->pdu_recv = 0;
862 	nvmet_tcp_map_pdu_iovec(cmd);
863 	queue->cmd = cmd;
864 	queue->rcv_state = NVMET_TCP_RECV_DATA;
865 
866 	return 0;
867 }
868 
869 static int nvmet_tcp_done_recv_pdu(struct nvmet_tcp_queue *queue)
870 {
871 	struct nvme_tcp_hdr *hdr = &queue->pdu.cmd.hdr;
872 	struct nvme_command *nvme_cmd = &queue->pdu.cmd.cmd;
873 	struct nvmet_req *req;
874 	int ret;
875 
876 	if (unlikely(queue->state == NVMET_TCP_Q_CONNECTING)) {
877 		if (hdr->type != nvme_tcp_icreq) {
878 			pr_err("unexpected pdu type (%d) before icreq\n",
879 				hdr->type);
880 			nvmet_tcp_fatal_error(queue);
881 			return -EPROTO;
882 		}
883 		return nvmet_tcp_handle_icreq(queue);
884 	}
885 
886 	if (hdr->type == nvme_tcp_h2c_data) {
887 		ret = nvmet_tcp_handle_h2c_data_pdu(queue);
888 		if (unlikely(ret))
889 			return ret;
890 		return 0;
891 	}
892 
893 	queue->cmd = nvmet_tcp_get_cmd(queue);
894 	if (unlikely(!queue->cmd)) {
895 		/* This should never happen */
896 		pr_err("queue %d: out of commands (%d) send_list_len: %d, opcode: %d",
897 			queue->idx, queue->nr_cmds, queue->send_list_len,
898 			nvme_cmd->common.opcode);
899 		nvmet_tcp_fatal_error(queue);
900 		return -ENOMEM;
901 	}
902 
903 	req = &queue->cmd->req;
904 	memcpy(req->cmd, nvme_cmd, sizeof(*nvme_cmd));
905 
906 	if (unlikely(!nvmet_req_init(req, &queue->nvme_cq,
907 			&queue->nvme_sq, &nvmet_tcp_ops))) {
908 		pr_err("failed cmd %p id %d opcode %d, data_len: %d\n",
909 			req->cmd, req->cmd->common.command_id,
910 			req->cmd->common.opcode,
911 			le32_to_cpu(req->cmd->common.dptr.sgl.length));
912 
913 		nvmet_tcp_handle_req_failure(queue, queue->cmd, req);
914 		return -EAGAIN;
915 	}
916 
917 	ret = nvmet_tcp_map_data(queue->cmd);
918 	if (unlikely(ret)) {
919 		pr_err("queue %d: failed to map data\n", queue->idx);
920 		if (nvmet_tcp_has_inline_data(queue->cmd))
921 			nvmet_tcp_fatal_error(queue);
922 		else
923 			nvmet_req_complete(req, ret);
924 		ret = -EAGAIN;
925 		goto out;
926 	}
927 
928 	if (nvmet_tcp_need_data_in(queue->cmd)) {
929 		if (nvmet_tcp_has_inline_data(queue->cmd)) {
930 			queue->rcv_state = NVMET_TCP_RECV_DATA;
931 			nvmet_tcp_map_pdu_iovec(queue->cmd);
932 			return 0;
933 		}
934 		/* send back R2T */
935 		nvmet_tcp_queue_response(&queue->cmd->req);
936 		goto out;
937 	}
938 
939 	queue->cmd->req.execute(&queue->cmd->req);
940 out:
941 	nvmet_prepare_receive_pdu(queue);
942 	return ret;
943 }
944 
945 static const u8 nvme_tcp_pdu_sizes[] = {
946 	[nvme_tcp_icreq]	= sizeof(struct nvme_tcp_icreq_pdu),
947 	[nvme_tcp_cmd]		= sizeof(struct nvme_tcp_cmd_pdu),
948 	[nvme_tcp_h2c_data]	= sizeof(struct nvme_tcp_data_pdu),
949 };
950 
951 static inline u8 nvmet_tcp_pdu_size(u8 type)
952 {
953 	size_t idx = type;
954 
955 	return (idx < ARRAY_SIZE(nvme_tcp_pdu_sizes) &&
956 		nvme_tcp_pdu_sizes[idx]) ?
957 			nvme_tcp_pdu_sizes[idx] : 0;
958 }
959 
960 static inline bool nvmet_tcp_pdu_valid(u8 type)
961 {
962 	switch (type) {
963 	case nvme_tcp_icreq:
964 	case nvme_tcp_cmd:
965 	case nvme_tcp_h2c_data:
966 		/* fallthru */
967 		return true;
968 	}
969 
970 	return false;
971 }
972 
973 static int nvmet_tcp_try_recv_pdu(struct nvmet_tcp_queue *queue)
974 {
975 	struct nvme_tcp_hdr *hdr = &queue->pdu.cmd.hdr;
976 	int len;
977 	struct kvec iov;
978 	struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
979 
980 recv:
981 	iov.iov_base = (void *)&queue->pdu + queue->offset;
982 	iov.iov_len = queue->left;
983 	len = kernel_recvmsg(queue->sock, &msg, &iov, 1,
984 			iov.iov_len, msg.msg_flags);
985 	if (unlikely(len < 0))
986 		return len;
987 
988 	queue->offset += len;
989 	queue->left -= len;
990 	if (queue->left)
991 		return -EAGAIN;
992 
993 	if (queue->offset == sizeof(struct nvme_tcp_hdr)) {
994 		u8 hdgst = nvmet_tcp_hdgst_len(queue);
995 
996 		if (unlikely(!nvmet_tcp_pdu_valid(hdr->type))) {
997 			pr_err("unexpected pdu type %d\n", hdr->type);
998 			nvmet_tcp_fatal_error(queue);
999 			return -EIO;
1000 		}
1001 
1002 		if (unlikely(hdr->hlen != nvmet_tcp_pdu_size(hdr->type))) {
1003 			pr_err("pdu %d bad hlen %d\n", hdr->type, hdr->hlen);
1004 			return -EIO;
1005 		}
1006 
1007 		queue->left = hdr->hlen - queue->offset + hdgst;
1008 		goto recv;
1009 	}
1010 
1011 	if (queue->hdr_digest &&
1012 	    nvmet_tcp_verify_hdgst(queue, &queue->pdu, queue->offset)) {
1013 		nvmet_tcp_fatal_error(queue); /* fatal */
1014 		return -EPROTO;
1015 	}
1016 
1017 	if (queue->data_digest &&
1018 	    nvmet_tcp_check_ddgst(queue, &queue->pdu)) {
1019 		nvmet_tcp_fatal_error(queue); /* fatal */
1020 		return -EPROTO;
1021 	}
1022 
1023 	return nvmet_tcp_done_recv_pdu(queue);
1024 }
1025 
1026 static void nvmet_tcp_prep_recv_ddgst(struct nvmet_tcp_cmd *cmd)
1027 {
1028 	struct nvmet_tcp_queue *queue = cmd->queue;
1029 
1030 	nvmet_tcp_ddgst(queue->rcv_hash, cmd);
1031 	queue->offset = 0;
1032 	queue->left = NVME_TCP_DIGEST_LENGTH;
1033 	queue->rcv_state = NVMET_TCP_RECV_DDGST;
1034 }
1035 
1036 static int nvmet_tcp_try_recv_data(struct nvmet_tcp_queue *queue)
1037 {
1038 	struct nvmet_tcp_cmd  *cmd = queue->cmd;
1039 	int ret;
1040 
1041 	while (msg_data_left(&cmd->recv_msg)) {
1042 		ret = sock_recvmsg(cmd->queue->sock, &cmd->recv_msg,
1043 			cmd->recv_msg.msg_flags);
1044 		if (ret <= 0)
1045 			return ret;
1046 
1047 		cmd->pdu_recv += ret;
1048 		cmd->rbytes_done += ret;
1049 	}
1050 
1051 	nvmet_tcp_unmap_pdu_iovec(cmd);
1052 
1053 	if (!(cmd->flags & NVMET_TCP_F_INIT_FAILED) &&
1054 	    cmd->rbytes_done == cmd->req.transfer_len) {
1055 		if (queue->data_digest) {
1056 			nvmet_tcp_prep_recv_ddgst(cmd);
1057 			return 0;
1058 		}
1059 		cmd->req.execute(&cmd->req);
1060 	}
1061 
1062 	nvmet_prepare_receive_pdu(queue);
1063 	return 0;
1064 }
1065 
1066 static int nvmet_tcp_try_recv_ddgst(struct nvmet_tcp_queue *queue)
1067 {
1068 	struct nvmet_tcp_cmd *cmd = queue->cmd;
1069 	int ret;
1070 	struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
1071 	struct kvec iov = {
1072 		.iov_base = (void *)&cmd->recv_ddgst + queue->offset,
1073 		.iov_len = queue->left
1074 	};
1075 
1076 	ret = kernel_recvmsg(queue->sock, &msg, &iov, 1,
1077 			iov.iov_len, msg.msg_flags);
1078 	if (unlikely(ret < 0))
1079 		return ret;
1080 
1081 	queue->offset += ret;
1082 	queue->left -= ret;
1083 	if (queue->left)
1084 		return -EAGAIN;
1085 
1086 	if (queue->data_digest && cmd->exp_ddgst != cmd->recv_ddgst) {
1087 		pr_err("queue %d: cmd %d pdu (%d) data digest error: recv %#x expected %#x\n",
1088 			queue->idx, cmd->req.cmd->common.command_id,
1089 			queue->pdu.cmd.hdr.type, le32_to_cpu(cmd->recv_ddgst),
1090 			le32_to_cpu(cmd->exp_ddgst));
1091 		nvmet_tcp_finish_cmd(cmd);
1092 		nvmet_tcp_fatal_error(queue);
1093 		ret = -EPROTO;
1094 		goto out;
1095 	}
1096 
1097 	if (!(cmd->flags & NVMET_TCP_F_INIT_FAILED) &&
1098 	    cmd->rbytes_done == cmd->req.transfer_len)
1099 		cmd->req.execute(&cmd->req);
1100 	ret = 0;
1101 out:
1102 	nvmet_prepare_receive_pdu(queue);
1103 	return ret;
1104 }
1105 
1106 static int nvmet_tcp_try_recv_one(struct nvmet_tcp_queue *queue)
1107 {
1108 	int result = 0;
1109 
1110 	if (unlikely(queue->rcv_state == NVMET_TCP_RECV_ERR))
1111 		return 0;
1112 
1113 	if (queue->rcv_state == NVMET_TCP_RECV_PDU) {
1114 		result = nvmet_tcp_try_recv_pdu(queue);
1115 		if (result != 0)
1116 			goto done_recv;
1117 	}
1118 
1119 	if (queue->rcv_state == NVMET_TCP_RECV_DATA) {
1120 		result = nvmet_tcp_try_recv_data(queue);
1121 		if (result != 0)
1122 			goto done_recv;
1123 	}
1124 
1125 	if (queue->rcv_state == NVMET_TCP_RECV_DDGST) {
1126 		result = nvmet_tcp_try_recv_ddgst(queue);
1127 		if (result != 0)
1128 			goto done_recv;
1129 	}
1130 
1131 done_recv:
1132 	if (result < 0) {
1133 		if (result == -EAGAIN)
1134 			return 0;
1135 		return result;
1136 	}
1137 	return 1;
1138 }
1139 
1140 static int nvmet_tcp_try_recv(struct nvmet_tcp_queue *queue,
1141 		int budget, int *recvs)
1142 {
1143 	int i, ret = 0;
1144 
1145 	for (i = 0; i < budget; i++) {
1146 		ret = nvmet_tcp_try_recv_one(queue);
1147 		if (ret <= 0)
1148 			break;
1149 		(*recvs)++;
1150 	}
1151 
1152 	return ret;
1153 }
1154 
1155 static void nvmet_tcp_schedule_release_queue(struct nvmet_tcp_queue *queue)
1156 {
1157 	spin_lock(&queue->state_lock);
1158 	if (queue->state != NVMET_TCP_Q_DISCONNECTING) {
1159 		queue->state = NVMET_TCP_Q_DISCONNECTING;
1160 		schedule_work(&queue->release_work);
1161 	}
1162 	spin_unlock(&queue->state_lock);
1163 }
1164 
1165 static void nvmet_tcp_io_work(struct work_struct *w)
1166 {
1167 	struct nvmet_tcp_queue *queue =
1168 		container_of(w, struct nvmet_tcp_queue, io_work);
1169 	bool pending;
1170 	int ret, ops = 0;
1171 
1172 	do {
1173 		pending = false;
1174 
1175 		ret = nvmet_tcp_try_recv(queue, NVMET_TCP_RECV_BUDGET, &ops);
1176 		if (ret > 0) {
1177 			pending = true;
1178 		} else if (ret < 0) {
1179 			if (ret == -EPIPE || ret == -ECONNRESET)
1180 				kernel_sock_shutdown(queue->sock, SHUT_RDWR);
1181 			else
1182 				nvmet_tcp_fatal_error(queue);
1183 			return;
1184 		}
1185 
1186 		ret = nvmet_tcp_try_send(queue, NVMET_TCP_SEND_BUDGET, &ops);
1187 		if (ret > 0) {
1188 			/* transmitted message/data */
1189 			pending = true;
1190 		} else if (ret < 0) {
1191 			if (ret == -EPIPE || ret == -ECONNRESET)
1192 				kernel_sock_shutdown(queue->sock, SHUT_RDWR);
1193 			else
1194 				nvmet_tcp_fatal_error(queue);
1195 			return;
1196 		}
1197 
1198 	} while (pending && ops < NVMET_TCP_IO_WORK_BUDGET);
1199 
1200 	/*
1201 	 * We exahusted our budget, requeue our selves
1202 	 */
1203 	if (pending)
1204 		queue_work_on(queue->cpu, nvmet_tcp_wq, &queue->io_work);
1205 }
1206 
1207 static int nvmet_tcp_alloc_cmd(struct nvmet_tcp_queue *queue,
1208 		struct nvmet_tcp_cmd *c)
1209 {
1210 	u8 hdgst = nvmet_tcp_hdgst_len(queue);
1211 
1212 	c->queue = queue;
1213 	c->req.port = queue->port->nport;
1214 
1215 	c->cmd_pdu = page_frag_alloc(&queue->pf_cache,
1216 			sizeof(*c->cmd_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1217 	if (!c->cmd_pdu)
1218 		return -ENOMEM;
1219 	c->req.cmd = &c->cmd_pdu->cmd;
1220 
1221 	c->rsp_pdu = page_frag_alloc(&queue->pf_cache,
1222 			sizeof(*c->rsp_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1223 	if (!c->rsp_pdu)
1224 		goto out_free_cmd;
1225 	c->req.cqe = &c->rsp_pdu->cqe;
1226 
1227 	c->data_pdu = page_frag_alloc(&queue->pf_cache,
1228 			sizeof(*c->data_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1229 	if (!c->data_pdu)
1230 		goto out_free_rsp;
1231 
1232 	c->r2t_pdu = page_frag_alloc(&queue->pf_cache,
1233 			sizeof(*c->r2t_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1234 	if (!c->r2t_pdu)
1235 		goto out_free_data;
1236 
1237 	c->recv_msg.msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
1238 
1239 	list_add_tail(&c->entry, &queue->free_list);
1240 
1241 	return 0;
1242 out_free_data:
1243 	page_frag_free(c->data_pdu);
1244 out_free_rsp:
1245 	page_frag_free(c->rsp_pdu);
1246 out_free_cmd:
1247 	page_frag_free(c->cmd_pdu);
1248 	return -ENOMEM;
1249 }
1250 
1251 static void nvmet_tcp_free_cmd(struct nvmet_tcp_cmd *c)
1252 {
1253 	page_frag_free(c->r2t_pdu);
1254 	page_frag_free(c->data_pdu);
1255 	page_frag_free(c->rsp_pdu);
1256 	page_frag_free(c->cmd_pdu);
1257 }
1258 
1259 static int nvmet_tcp_alloc_cmds(struct nvmet_tcp_queue *queue)
1260 {
1261 	struct nvmet_tcp_cmd *cmds;
1262 	int i, ret = -EINVAL, nr_cmds = queue->nr_cmds;
1263 
1264 	cmds = kcalloc(nr_cmds, sizeof(struct nvmet_tcp_cmd), GFP_KERNEL);
1265 	if (!cmds)
1266 		goto out;
1267 
1268 	for (i = 0; i < nr_cmds; i++) {
1269 		ret = nvmet_tcp_alloc_cmd(queue, cmds + i);
1270 		if (ret)
1271 			goto out_free;
1272 	}
1273 
1274 	queue->cmds = cmds;
1275 
1276 	return 0;
1277 out_free:
1278 	while (--i >= 0)
1279 		nvmet_tcp_free_cmd(cmds + i);
1280 	kfree(cmds);
1281 out:
1282 	return ret;
1283 }
1284 
1285 static void nvmet_tcp_free_cmds(struct nvmet_tcp_queue *queue)
1286 {
1287 	struct nvmet_tcp_cmd *cmds = queue->cmds;
1288 	int i;
1289 
1290 	for (i = 0; i < queue->nr_cmds; i++)
1291 		nvmet_tcp_free_cmd(cmds + i);
1292 
1293 	nvmet_tcp_free_cmd(&queue->connect);
1294 	kfree(cmds);
1295 }
1296 
1297 static void nvmet_tcp_restore_socket_callbacks(struct nvmet_tcp_queue *queue)
1298 {
1299 	struct socket *sock = queue->sock;
1300 
1301 	write_lock_bh(&sock->sk->sk_callback_lock);
1302 	sock->sk->sk_data_ready =  queue->data_ready;
1303 	sock->sk->sk_state_change = queue->state_change;
1304 	sock->sk->sk_write_space = queue->write_space;
1305 	sock->sk->sk_user_data = NULL;
1306 	write_unlock_bh(&sock->sk->sk_callback_lock);
1307 }
1308 
1309 static void nvmet_tcp_finish_cmd(struct nvmet_tcp_cmd *cmd)
1310 {
1311 	nvmet_req_uninit(&cmd->req);
1312 	nvmet_tcp_unmap_pdu_iovec(cmd);
1313 	kfree(cmd->iov);
1314 	sgl_free(cmd->req.sg);
1315 }
1316 
1317 static void nvmet_tcp_uninit_data_in_cmds(struct nvmet_tcp_queue *queue)
1318 {
1319 	struct nvmet_tcp_cmd *cmd = queue->cmds;
1320 	int i;
1321 
1322 	for (i = 0; i < queue->nr_cmds; i++, cmd++) {
1323 		if (nvmet_tcp_need_data_in(cmd))
1324 			nvmet_tcp_finish_cmd(cmd);
1325 	}
1326 
1327 	if (!queue->nr_cmds && nvmet_tcp_need_data_in(&queue->connect)) {
1328 		/* failed in connect */
1329 		nvmet_tcp_finish_cmd(&queue->connect);
1330 	}
1331 }
1332 
1333 static void nvmet_tcp_release_queue_work(struct work_struct *w)
1334 {
1335 	struct nvmet_tcp_queue *queue =
1336 		container_of(w, struct nvmet_tcp_queue, release_work);
1337 
1338 	mutex_lock(&nvmet_tcp_queue_mutex);
1339 	list_del_init(&queue->queue_list);
1340 	mutex_unlock(&nvmet_tcp_queue_mutex);
1341 
1342 	nvmet_tcp_restore_socket_callbacks(queue);
1343 	flush_work(&queue->io_work);
1344 
1345 	nvmet_tcp_uninit_data_in_cmds(queue);
1346 	nvmet_sq_destroy(&queue->nvme_sq);
1347 	cancel_work_sync(&queue->io_work);
1348 	sock_release(queue->sock);
1349 	nvmet_tcp_free_cmds(queue);
1350 	if (queue->hdr_digest || queue->data_digest)
1351 		nvmet_tcp_free_crypto(queue);
1352 	ida_simple_remove(&nvmet_tcp_queue_ida, queue->idx);
1353 
1354 	kfree(queue);
1355 }
1356 
1357 static void nvmet_tcp_data_ready(struct sock *sk)
1358 {
1359 	struct nvmet_tcp_queue *queue;
1360 
1361 	read_lock_bh(&sk->sk_callback_lock);
1362 	queue = sk->sk_user_data;
1363 	if (likely(queue))
1364 		queue_work_on(queue->cpu, nvmet_tcp_wq, &queue->io_work);
1365 	read_unlock_bh(&sk->sk_callback_lock);
1366 }
1367 
1368 static void nvmet_tcp_write_space(struct sock *sk)
1369 {
1370 	struct nvmet_tcp_queue *queue;
1371 
1372 	read_lock_bh(&sk->sk_callback_lock);
1373 	queue = sk->sk_user_data;
1374 	if (unlikely(!queue))
1375 		goto out;
1376 
1377 	if (unlikely(queue->state == NVMET_TCP_Q_CONNECTING)) {
1378 		queue->write_space(sk);
1379 		goto out;
1380 	}
1381 
1382 	if (sk_stream_is_writeable(sk)) {
1383 		clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1384 		queue_work_on(queue->cpu, nvmet_tcp_wq, &queue->io_work);
1385 	}
1386 out:
1387 	read_unlock_bh(&sk->sk_callback_lock);
1388 }
1389 
1390 static void nvmet_tcp_state_change(struct sock *sk)
1391 {
1392 	struct nvmet_tcp_queue *queue;
1393 
1394 	write_lock_bh(&sk->sk_callback_lock);
1395 	queue = sk->sk_user_data;
1396 	if (!queue)
1397 		goto done;
1398 
1399 	switch (sk->sk_state) {
1400 	case TCP_FIN_WAIT1:
1401 	case TCP_CLOSE_WAIT:
1402 	case TCP_CLOSE:
1403 		/* FALLTHRU */
1404 		sk->sk_user_data = NULL;
1405 		nvmet_tcp_schedule_release_queue(queue);
1406 		break;
1407 	default:
1408 		pr_warn("queue %d unhandled state %d\n",
1409 			queue->idx, sk->sk_state);
1410 	}
1411 done:
1412 	write_unlock_bh(&sk->sk_callback_lock);
1413 }
1414 
1415 static int nvmet_tcp_set_queue_sock(struct nvmet_tcp_queue *queue)
1416 {
1417 	struct socket *sock = queue->sock;
1418 	struct inet_sock *inet = inet_sk(sock->sk);
1419 	struct linger sol = { .l_onoff = 1, .l_linger = 0 };
1420 	int ret;
1421 
1422 	ret = kernel_getsockname(sock,
1423 		(struct sockaddr *)&queue->sockaddr);
1424 	if (ret < 0)
1425 		return ret;
1426 
1427 	ret = kernel_getpeername(sock,
1428 		(struct sockaddr *)&queue->sockaddr_peer);
1429 	if (ret < 0)
1430 		return ret;
1431 
1432 	/*
1433 	 * Cleanup whatever is sitting in the TCP transmit queue on socket
1434 	 * close. This is done to prevent stale data from being sent should
1435 	 * the network connection be restored before TCP times out.
1436 	 */
1437 	ret = kernel_setsockopt(sock, SOL_SOCKET, SO_LINGER,
1438 			(char *)&sol, sizeof(sol));
1439 	if (ret)
1440 		return ret;
1441 
1442 	/* Set socket type of service */
1443 	if (inet->rcv_tos > 0) {
1444 		int tos = inet->rcv_tos;
1445 
1446 		ret = kernel_setsockopt(sock, SOL_IP, IP_TOS,
1447 				(char *)&tos, sizeof(tos));
1448 		if (ret)
1449 			return ret;
1450 	}
1451 
1452 	write_lock_bh(&sock->sk->sk_callback_lock);
1453 	sock->sk->sk_user_data = queue;
1454 	queue->data_ready = sock->sk->sk_data_ready;
1455 	sock->sk->sk_data_ready = nvmet_tcp_data_ready;
1456 	queue->state_change = sock->sk->sk_state_change;
1457 	sock->sk->sk_state_change = nvmet_tcp_state_change;
1458 	queue->write_space = sock->sk->sk_write_space;
1459 	sock->sk->sk_write_space = nvmet_tcp_write_space;
1460 	write_unlock_bh(&sock->sk->sk_callback_lock);
1461 
1462 	return 0;
1463 }
1464 
1465 static int nvmet_tcp_alloc_queue(struct nvmet_tcp_port *port,
1466 		struct socket *newsock)
1467 {
1468 	struct nvmet_tcp_queue *queue;
1469 	int ret;
1470 
1471 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
1472 	if (!queue)
1473 		return -ENOMEM;
1474 
1475 	INIT_WORK(&queue->release_work, nvmet_tcp_release_queue_work);
1476 	INIT_WORK(&queue->io_work, nvmet_tcp_io_work);
1477 	queue->sock = newsock;
1478 	queue->port = port;
1479 	queue->nr_cmds = 0;
1480 	spin_lock_init(&queue->state_lock);
1481 	queue->state = NVMET_TCP_Q_CONNECTING;
1482 	INIT_LIST_HEAD(&queue->free_list);
1483 	init_llist_head(&queue->resp_list);
1484 	INIT_LIST_HEAD(&queue->resp_send_list);
1485 
1486 	queue->idx = ida_simple_get(&nvmet_tcp_queue_ida, 0, 0, GFP_KERNEL);
1487 	if (queue->idx < 0) {
1488 		ret = queue->idx;
1489 		goto out_free_queue;
1490 	}
1491 
1492 	ret = nvmet_tcp_alloc_cmd(queue, &queue->connect);
1493 	if (ret)
1494 		goto out_ida_remove;
1495 
1496 	ret = nvmet_sq_init(&queue->nvme_sq);
1497 	if (ret)
1498 		goto out_free_connect;
1499 
1500 	port->last_cpu = cpumask_next_wrap(port->last_cpu,
1501 				cpu_online_mask, -1, false);
1502 	queue->cpu = port->last_cpu;
1503 	nvmet_prepare_receive_pdu(queue);
1504 
1505 	mutex_lock(&nvmet_tcp_queue_mutex);
1506 	list_add_tail(&queue->queue_list, &nvmet_tcp_queue_list);
1507 	mutex_unlock(&nvmet_tcp_queue_mutex);
1508 
1509 	ret = nvmet_tcp_set_queue_sock(queue);
1510 	if (ret)
1511 		goto out_destroy_sq;
1512 
1513 	queue_work_on(queue->cpu, nvmet_tcp_wq, &queue->io_work);
1514 
1515 	return 0;
1516 out_destroy_sq:
1517 	mutex_lock(&nvmet_tcp_queue_mutex);
1518 	list_del_init(&queue->queue_list);
1519 	mutex_unlock(&nvmet_tcp_queue_mutex);
1520 	nvmet_sq_destroy(&queue->nvme_sq);
1521 out_free_connect:
1522 	nvmet_tcp_free_cmd(&queue->connect);
1523 out_ida_remove:
1524 	ida_simple_remove(&nvmet_tcp_queue_ida, queue->idx);
1525 out_free_queue:
1526 	kfree(queue);
1527 	return ret;
1528 }
1529 
1530 static void nvmet_tcp_accept_work(struct work_struct *w)
1531 {
1532 	struct nvmet_tcp_port *port =
1533 		container_of(w, struct nvmet_tcp_port, accept_work);
1534 	struct socket *newsock;
1535 	int ret;
1536 
1537 	while (true) {
1538 		ret = kernel_accept(port->sock, &newsock, O_NONBLOCK);
1539 		if (ret < 0) {
1540 			if (ret != -EAGAIN)
1541 				pr_warn("failed to accept err=%d\n", ret);
1542 			return;
1543 		}
1544 		ret = nvmet_tcp_alloc_queue(port, newsock);
1545 		if (ret) {
1546 			pr_err("failed to allocate queue\n");
1547 			sock_release(newsock);
1548 		}
1549 	}
1550 }
1551 
1552 static void nvmet_tcp_listen_data_ready(struct sock *sk)
1553 {
1554 	struct nvmet_tcp_port *port;
1555 
1556 	read_lock_bh(&sk->sk_callback_lock);
1557 	port = sk->sk_user_data;
1558 	if (!port)
1559 		goto out;
1560 
1561 	if (sk->sk_state == TCP_LISTEN)
1562 		schedule_work(&port->accept_work);
1563 out:
1564 	read_unlock_bh(&sk->sk_callback_lock);
1565 }
1566 
1567 static int nvmet_tcp_add_port(struct nvmet_port *nport)
1568 {
1569 	struct nvmet_tcp_port *port;
1570 	__kernel_sa_family_t af;
1571 	int opt, ret;
1572 
1573 	port = kzalloc(sizeof(*port), GFP_KERNEL);
1574 	if (!port)
1575 		return -ENOMEM;
1576 
1577 	switch (nport->disc_addr.adrfam) {
1578 	case NVMF_ADDR_FAMILY_IP4:
1579 		af = AF_INET;
1580 		break;
1581 	case NVMF_ADDR_FAMILY_IP6:
1582 		af = AF_INET6;
1583 		break;
1584 	default:
1585 		pr_err("address family %d not supported\n",
1586 				nport->disc_addr.adrfam);
1587 		ret = -EINVAL;
1588 		goto err_port;
1589 	}
1590 
1591 	ret = inet_pton_with_scope(&init_net, af, nport->disc_addr.traddr,
1592 			nport->disc_addr.trsvcid, &port->addr);
1593 	if (ret) {
1594 		pr_err("malformed ip/port passed: %s:%s\n",
1595 			nport->disc_addr.traddr, nport->disc_addr.trsvcid);
1596 		goto err_port;
1597 	}
1598 
1599 	port->nport = nport;
1600 	port->last_cpu = -1;
1601 	INIT_WORK(&port->accept_work, nvmet_tcp_accept_work);
1602 	if (port->nport->inline_data_size < 0)
1603 		port->nport->inline_data_size = NVMET_TCP_DEF_INLINE_DATA_SIZE;
1604 
1605 	ret = sock_create(port->addr.ss_family, SOCK_STREAM,
1606 				IPPROTO_TCP, &port->sock);
1607 	if (ret) {
1608 		pr_err("failed to create a socket\n");
1609 		goto err_port;
1610 	}
1611 
1612 	port->sock->sk->sk_user_data = port;
1613 	port->data_ready = port->sock->sk->sk_data_ready;
1614 	port->sock->sk->sk_data_ready = nvmet_tcp_listen_data_ready;
1615 
1616 	opt = 1;
1617 	ret = kernel_setsockopt(port->sock, IPPROTO_TCP,
1618 			TCP_NODELAY, (char *)&opt, sizeof(opt));
1619 	if (ret) {
1620 		pr_err("failed to set TCP_NODELAY sock opt %d\n", ret);
1621 		goto err_sock;
1622 	}
1623 
1624 	ret = kernel_setsockopt(port->sock, SOL_SOCKET, SO_REUSEADDR,
1625 			(char *)&opt, sizeof(opt));
1626 	if (ret) {
1627 		pr_err("failed to set SO_REUSEADDR sock opt %d\n", ret);
1628 		goto err_sock;
1629 	}
1630 
1631 	ret = kernel_bind(port->sock, (struct sockaddr *)&port->addr,
1632 			sizeof(port->addr));
1633 	if (ret) {
1634 		pr_err("failed to bind port socket %d\n", ret);
1635 		goto err_sock;
1636 	}
1637 
1638 	ret = kernel_listen(port->sock, 128);
1639 	if (ret) {
1640 		pr_err("failed to listen %d on port sock\n", ret);
1641 		goto err_sock;
1642 	}
1643 
1644 	nport->priv = port;
1645 	pr_info("enabling port %d (%pISpc)\n",
1646 		le16_to_cpu(nport->disc_addr.portid), &port->addr);
1647 
1648 	return 0;
1649 
1650 err_sock:
1651 	sock_release(port->sock);
1652 err_port:
1653 	kfree(port);
1654 	return ret;
1655 }
1656 
1657 static void nvmet_tcp_remove_port(struct nvmet_port *nport)
1658 {
1659 	struct nvmet_tcp_port *port = nport->priv;
1660 
1661 	write_lock_bh(&port->sock->sk->sk_callback_lock);
1662 	port->sock->sk->sk_data_ready = port->data_ready;
1663 	port->sock->sk->sk_user_data = NULL;
1664 	write_unlock_bh(&port->sock->sk->sk_callback_lock);
1665 	cancel_work_sync(&port->accept_work);
1666 
1667 	sock_release(port->sock);
1668 	kfree(port);
1669 }
1670 
1671 static void nvmet_tcp_delete_ctrl(struct nvmet_ctrl *ctrl)
1672 {
1673 	struct nvmet_tcp_queue *queue;
1674 
1675 	mutex_lock(&nvmet_tcp_queue_mutex);
1676 	list_for_each_entry(queue, &nvmet_tcp_queue_list, queue_list)
1677 		if (queue->nvme_sq.ctrl == ctrl)
1678 			kernel_sock_shutdown(queue->sock, SHUT_RDWR);
1679 	mutex_unlock(&nvmet_tcp_queue_mutex);
1680 }
1681 
1682 static u16 nvmet_tcp_install_queue(struct nvmet_sq *sq)
1683 {
1684 	struct nvmet_tcp_queue *queue =
1685 		container_of(sq, struct nvmet_tcp_queue, nvme_sq);
1686 
1687 	if (sq->qid == 0) {
1688 		/* Let inflight controller teardown complete */
1689 		flush_scheduled_work();
1690 	}
1691 
1692 	queue->nr_cmds = sq->size * 2;
1693 	if (nvmet_tcp_alloc_cmds(queue))
1694 		return NVME_SC_INTERNAL;
1695 	return 0;
1696 }
1697 
1698 static void nvmet_tcp_disc_port_addr(struct nvmet_req *req,
1699 		struct nvmet_port *nport, char *traddr)
1700 {
1701 	struct nvmet_tcp_port *port = nport->priv;
1702 
1703 	if (inet_addr_is_any((struct sockaddr *)&port->addr)) {
1704 		struct nvmet_tcp_cmd *cmd =
1705 			container_of(req, struct nvmet_tcp_cmd, req);
1706 		struct nvmet_tcp_queue *queue = cmd->queue;
1707 
1708 		sprintf(traddr, "%pISc", (struct sockaddr *)&queue->sockaddr);
1709 	} else {
1710 		memcpy(traddr, nport->disc_addr.traddr, NVMF_TRADDR_SIZE);
1711 	}
1712 }
1713 
1714 static struct nvmet_fabrics_ops nvmet_tcp_ops = {
1715 	.owner			= THIS_MODULE,
1716 	.type			= NVMF_TRTYPE_TCP,
1717 	.msdbd			= 1,
1718 	.has_keyed_sgls		= 0,
1719 	.add_port		= nvmet_tcp_add_port,
1720 	.remove_port		= nvmet_tcp_remove_port,
1721 	.queue_response		= nvmet_tcp_queue_response,
1722 	.delete_ctrl		= nvmet_tcp_delete_ctrl,
1723 	.install_queue		= nvmet_tcp_install_queue,
1724 	.disc_traddr		= nvmet_tcp_disc_port_addr,
1725 };
1726 
1727 static int __init nvmet_tcp_init(void)
1728 {
1729 	int ret;
1730 
1731 	nvmet_tcp_wq = alloc_workqueue("nvmet_tcp_wq", WQ_HIGHPRI, 0);
1732 	if (!nvmet_tcp_wq)
1733 		return -ENOMEM;
1734 
1735 	ret = nvmet_register_transport(&nvmet_tcp_ops);
1736 	if (ret)
1737 		goto err;
1738 
1739 	return 0;
1740 err:
1741 	destroy_workqueue(nvmet_tcp_wq);
1742 	return ret;
1743 }
1744 
1745 static void __exit nvmet_tcp_exit(void)
1746 {
1747 	struct nvmet_tcp_queue *queue;
1748 
1749 	nvmet_unregister_transport(&nvmet_tcp_ops);
1750 
1751 	flush_scheduled_work();
1752 	mutex_lock(&nvmet_tcp_queue_mutex);
1753 	list_for_each_entry(queue, &nvmet_tcp_queue_list, queue_list)
1754 		kernel_sock_shutdown(queue->sock, SHUT_RDWR);
1755 	mutex_unlock(&nvmet_tcp_queue_mutex);
1756 	flush_scheduled_work();
1757 
1758 	destroy_workqueue(nvmet_tcp_wq);
1759 }
1760 
1761 module_init(nvmet_tcp_init);
1762 module_exit(nvmet_tcp_exit);
1763 
1764 MODULE_LICENSE("GPL v2");
1765 MODULE_ALIAS("nvmet-transport-3"); /* 3 == NVMF_TRTYPE_TCP */
1766