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#define NVMET_TCP_MAXH2CDATA		0x400000 /* 16M arbitrary limit */
22
23/* Define the socket priority to use for connections were it is desirable
24 * that the NIC consider performing optimized packet processing or filtering.
25 * A non-zero value being sufficient to indicate general consideration of any
26 * possible optimization.  Making it a module param allows for alternative
27 * values that may be unique for some NIC implementations.
28 */
29static int so_priority;
30module_param(so_priority, int, 0644);
31MODULE_PARM_DESC(so_priority, "nvmet tcp socket optimize priority");
32
33#define NVMET_TCP_RECV_BUDGET		8
34#define NVMET_TCP_SEND_BUDGET		8
35#define NVMET_TCP_IO_WORK_BUDGET	64
36
37enum nvmet_tcp_send_state {
38	NVMET_TCP_SEND_DATA_PDU,
39	NVMET_TCP_SEND_DATA,
40	NVMET_TCP_SEND_R2T,
41	NVMET_TCP_SEND_DDGST,
42	NVMET_TCP_SEND_RESPONSE
43};
44
45enum nvmet_tcp_recv_state {
46	NVMET_TCP_RECV_PDU,
47	NVMET_TCP_RECV_DATA,
48	NVMET_TCP_RECV_DDGST,
49	NVMET_TCP_RECV_ERR,
50};
51
52enum {
53	NVMET_TCP_F_INIT_FAILED = (1 << 0),
54};
55
56struct nvmet_tcp_cmd {
57	struct nvmet_tcp_queue		*queue;
58	struct nvmet_req		req;
59
60	struct nvme_tcp_cmd_pdu		*cmd_pdu;
61	struct nvme_tcp_rsp_pdu		*rsp_pdu;
62	struct nvme_tcp_data_pdu	*data_pdu;
63	struct nvme_tcp_r2t_pdu		*r2t_pdu;
64
65	u32				rbytes_done;
66	u32				wbytes_done;
67
68	u32				pdu_len;
69	u32				pdu_recv;
70	int				sg_idx;
71	int				nr_mapped;
72	struct msghdr			recv_msg;
73	struct kvec			*iov;
74	u32				flags;
75
76	struct list_head		entry;
77	struct llist_node		lentry;
78
79	/* send state */
80	u32				offset;
81	struct scatterlist		*cur_sg;
82	enum nvmet_tcp_send_state	state;
83
84	__le32				exp_ddgst;
85	__le32				recv_ddgst;
86};
87
88enum nvmet_tcp_queue_state {
89	NVMET_TCP_Q_CONNECTING,
90	NVMET_TCP_Q_LIVE,
91	NVMET_TCP_Q_DISCONNECTING,
92};
93
94struct nvmet_tcp_queue {
95	struct socket		*sock;
96	struct nvmet_tcp_port	*port;
97	struct work_struct	io_work;
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
142struct nvmet_tcp_port {
143	struct socket		*sock;
144	struct work_struct	accept_work;
145	struct nvmet_port	*nport;
146	struct sockaddr_storage addr;
147	void (*data_ready)(struct sock *);
148};
149
150static DEFINE_IDA(nvmet_tcp_queue_ida);
151static LIST_HEAD(nvmet_tcp_queue_list);
152static DEFINE_MUTEX(nvmet_tcp_queue_mutex);
153
154static struct workqueue_struct *nvmet_tcp_wq;
155static const struct nvmet_fabrics_ops nvmet_tcp_ops;
156static void nvmet_tcp_free_cmd(struct nvmet_tcp_cmd *c);
157static void nvmet_tcp_finish_cmd(struct nvmet_tcp_cmd *cmd);
158
159static inline u16 nvmet_tcp_cmd_tag(struct nvmet_tcp_queue *queue,
160		struct nvmet_tcp_cmd *cmd)
161{
162	if (unlikely(!queue->nr_cmds)) {
163		/* We didn't allocate cmds yet, send 0xffff */
164		return USHRT_MAX;
165	}
166
167	return cmd - queue->cmds;
168}
169
170static inline bool nvmet_tcp_has_data_in(struct nvmet_tcp_cmd *cmd)
171{
172	return nvme_is_write(cmd->req.cmd) &&
173		cmd->rbytes_done < cmd->req.transfer_len;
174}
175
176static inline bool nvmet_tcp_need_data_in(struct nvmet_tcp_cmd *cmd)
177{
178	return nvmet_tcp_has_data_in(cmd) && !cmd->req.cqe->status;
179}
180
181static inline bool nvmet_tcp_need_data_out(struct nvmet_tcp_cmd *cmd)
182{
183	return !nvme_is_write(cmd->req.cmd) &&
184		cmd->req.transfer_len > 0 &&
185		!cmd->req.cqe->status;
186}
187
188static inline bool nvmet_tcp_has_inline_data(struct nvmet_tcp_cmd *cmd)
189{
190	return nvme_is_write(cmd->req.cmd) && cmd->pdu_len &&
191		!cmd->rbytes_done;
192}
193
194static inline struct nvmet_tcp_cmd *
195nvmet_tcp_get_cmd(struct nvmet_tcp_queue *queue)
196{
197	struct nvmet_tcp_cmd *cmd;
198
199	cmd = list_first_entry_or_null(&queue->free_list,
200				struct nvmet_tcp_cmd, entry);
201	if (!cmd)
202		return NULL;
203	list_del_init(&cmd->entry);
204
205	cmd->rbytes_done = cmd->wbytes_done = 0;
206	cmd->pdu_len = 0;
207	cmd->pdu_recv = 0;
208	cmd->iov = NULL;
209	cmd->flags = 0;
210	return cmd;
211}
212
213static inline void nvmet_tcp_put_cmd(struct nvmet_tcp_cmd *cmd)
214{
215	if (unlikely(cmd == &cmd->queue->connect))
216		return;
217
218	list_add_tail(&cmd->entry, &cmd->queue->free_list);
219}
220
221static inline int queue_cpu(struct nvmet_tcp_queue *queue)
222{
223	return queue->sock->sk->sk_incoming_cpu;
224}
225
226static inline u8 nvmet_tcp_hdgst_len(struct nvmet_tcp_queue *queue)
227{
228	return queue->hdr_digest ? NVME_TCP_DIGEST_LENGTH : 0;
229}
230
231static inline u8 nvmet_tcp_ddgst_len(struct nvmet_tcp_queue *queue)
232{
233	return queue->data_digest ? NVME_TCP_DIGEST_LENGTH : 0;
234}
235
236static inline void nvmet_tcp_hdgst(struct ahash_request *hash,
237		void *pdu, size_t len)
238{
239	struct scatterlist sg;
240
241	sg_init_one(&sg, pdu, len);
242	ahash_request_set_crypt(hash, &sg, pdu + len, len);
243	crypto_ahash_digest(hash);
244}
245
246static int nvmet_tcp_verify_hdgst(struct nvmet_tcp_queue *queue,
247	void *pdu, size_t len)
248{
249	struct nvme_tcp_hdr *hdr = pdu;
250	__le32 recv_digest;
251	__le32 exp_digest;
252
253	if (unlikely(!(hdr->flags & NVME_TCP_F_HDGST))) {
254		pr_err("queue %d: header digest enabled but no header digest\n",
255			queue->idx);
256		return -EPROTO;
257	}
258
259	recv_digest = *(__le32 *)(pdu + hdr->hlen);
260	nvmet_tcp_hdgst(queue->rcv_hash, pdu, len);
261	exp_digest = *(__le32 *)(pdu + hdr->hlen);
262	if (recv_digest != exp_digest) {
263		pr_err("queue %d: header digest error: recv %#x expected %#x\n",
264			queue->idx, le32_to_cpu(recv_digest),
265			le32_to_cpu(exp_digest));
266		return -EPROTO;
267	}
268
269	return 0;
270}
271
272static int nvmet_tcp_check_ddgst(struct nvmet_tcp_queue *queue, void *pdu)
273{
274	struct nvme_tcp_hdr *hdr = pdu;
275	u8 digest_len = nvmet_tcp_hdgst_len(queue);
276	u32 len;
277
278	len = le32_to_cpu(hdr->plen) - hdr->hlen -
279		(hdr->flags & NVME_TCP_F_HDGST ? digest_len : 0);
280
281	if (unlikely(len && !(hdr->flags & NVME_TCP_F_DDGST))) {
282		pr_err("queue %d: data digest flag is cleared\n", queue->idx);
283		return -EPROTO;
284	}
285
286	return 0;
287}
288
289static void nvmet_tcp_unmap_pdu_iovec(struct nvmet_tcp_cmd *cmd)
290{
291	struct scatterlist *sg;
292	int i;
293
294	sg = &cmd->req.sg[cmd->sg_idx];
295
296	for (i = 0; i < cmd->nr_mapped; i++)
297		kunmap(sg_page(&sg[i]));
298}
299
300static void nvmet_tcp_map_pdu_iovec(struct nvmet_tcp_cmd *cmd)
301{
302	struct kvec *iov = cmd->iov;
303	struct scatterlist *sg;
304	u32 length, offset, sg_offset;
305
306	length = cmd->pdu_len;
307	cmd->nr_mapped = DIV_ROUND_UP(length, PAGE_SIZE);
308	offset = cmd->rbytes_done;
309	cmd->sg_idx = offset / PAGE_SIZE;
310	sg_offset = offset % PAGE_SIZE;
311	sg = &cmd->req.sg[cmd->sg_idx];
312
313	while (length) {
314		u32 iov_len = min_t(u32, length, sg->length - sg_offset);
315
316		iov->iov_base = kmap(sg_page(sg)) + sg->offset + sg_offset;
317		iov->iov_len = iov_len;
318
319		length -= iov_len;
320		sg = sg_next(sg);
321		iov++;
322		sg_offset = 0;
323	}
324
325	iov_iter_kvec(&cmd->recv_msg.msg_iter, READ, cmd->iov,
326		cmd->nr_mapped, cmd->pdu_len);
327}
328
329static void nvmet_tcp_fatal_error(struct nvmet_tcp_queue *queue)
330{
331	queue->rcv_state = NVMET_TCP_RECV_ERR;
332	if (queue->nvme_sq.ctrl)
333		nvmet_ctrl_fatal_error(queue->nvme_sq.ctrl);
334	else
335		kernel_sock_shutdown(queue->sock, SHUT_RDWR);
336}
337
338static void nvmet_tcp_socket_error(struct nvmet_tcp_queue *queue, int status)
339{
340	queue->rcv_state = NVMET_TCP_RECV_ERR;
341	if (status == -EPIPE || status == -ECONNRESET)
342		kernel_sock_shutdown(queue->sock, SHUT_RDWR);
343	else
344		nvmet_tcp_fatal_error(queue);
345}
346
347static int nvmet_tcp_map_data(struct nvmet_tcp_cmd *cmd)
348{
349	struct nvme_sgl_desc *sgl = &cmd->req.cmd->common.dptr.sgl;
350	u32 len = le32_to_cpu(sgl->length);
351
352	if (!len)
353		return 0;
354
355	if (sgl->type == ((NVME_SGL_FMT_DATA_DESC << 4) |
356			  NVME_SGL_FMT_OFFSET)) {
357		if (!nvme_is_write(cmd->req.cmd))
358			return NVME_SC_INVALID_FIELD | NVME_SC_DNR;
359
360		if (len > cmd->req.port->inline_data_size)
361			return NVME_SC_SGL_INVALID_OFFSET | NVME_SC_DNR;
362		cmd->pdu_len = len;
363	}
364	cmd->req.transfer_len += len;
365
366	cmd->req.sg = sgl_alloc(len, GFP_KERNEL, &cmd->req.sg_cnt);
367	if (!cmd->req.sg)
368		return NVME_SC_INTERNAL;
369	cmd->cur_sg = cmd->req.sg;
370
371	if (nvmet_tcp_has_data_in(cmd)) {
372		cmd->iov = kmalloc_array(cmd->req.sg_cnt,
373				sizeof(*cmd->iov), GFP_KERNEL);
374		if (!cmd->iov)
375			goto err;
376	}
377
378	return 0;
379err:
380	sgl_free(cmd->req.sg);
381	return NVME_SC_INTERNAL;
382}
383
384static void nvmet_tcp_send_ddgst(struct ahash_request *hash,
385		struct nvmet_tcp_cmd *cmd)
386{
387	ahash_request_set_crypt(hash, cmd->req.sg,
388		(void *)&cmd->exp_ddgst, cmd->req.transfer_len);
389	crypto_ahash_digest(hash);
390}
391
392static void nvmet_tcp_recv_ddgst(struct ahash_request *hash,
393		struct nvmet_tcp_cmd *cmd)
394{
395	struct scatterlist sg;
396	struct kvec *iov;
397	int i;
398
399	crypto_ahash_init(hash);
400	for (i = 0, iov = cmd->iov; i < cmd->nr_mapped; i++, iov++) {
401		sg_init_one(&sg, iov->iov_base, iov->iov_len);
402		ahash_request_set_crypt(hash, &sg, NULL, iov->iov_len);
403		crypto_ahash_update(hash);
404	}
405	ahash_request_set_crypt(hash, NULL, (void *)&cmd->exp_ddgst, 0);
406	crypto_ahash_final(hash);
407}
408
409static void nvmet_setup_c2h_data_pdu(struct nvmet_tcp_cmd *cmd)
410{
411	struct nvme_tcp_data_pdu *pdu = cmd->data_pdu;
412	struct nvmet_tcp_queue *queue = cmd->queue;
413	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
414	u8 ddgst = nvmet_tcp_ddgst_len(cmd->queue);
415
416	cmd->offset = 0;
417	cmd->state = NVMET_TCP_SEND_DATA_PDU;
418
419	pdu->hdr.type = nvme_tcp_c2h_data;
420	pdu->hdr.flags = NVME_TCP_F_DATA_LAST | (queue->nvme_sq.sqhd_disabled ?
421						NVME_TCP_F_DATA_SUCCESS : 0);
422	pdu->hdr.hlen = sizeof(*pdu);
423	pdu->hdr.pdo = pdu->hdr.hlen + hdgst;
424	pdu->hdr.plen =
425		cpu_to_le32(pdu->hdr.hlen + hdgst +
426				cmd->req.transfer_len + ddgst);
427	pdu->command_id = cmd->req.cqe->command_id;
428	pdu->data_length = cpu_to_le32(cmd->req.transfer_len);
429	pdu->data_offset = cpu_to_le32(cmd->wbytes_done);
430
431	if (queue->data_digest) {
432		pdu->hdr.flags |= NVME_TCP_F_DDGST;
433		nvmet_tcp_send_ddgst(queue->snd_hash, cmd);
434	}
435
436	if (cmd->queue->hdr_digest) {
437		pdu->hdr.flags |= NVME_TCP_F_HDGST;
438		nvmet_tcp_hdgst(queue->snd_hash, pdu, sizeof(*pdu));
439	}
440}
441
442static void nvmet_setup_r2t_pdu(struct nvmet_tcp_cmd *cmd)
443{
444	struct nvme_tcp_r2t_pdu *pdu = cmd->r2t_pdu;
445	struct nvmet_tcp_queue *queue = cmd->queue;
446	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
447
448	cmd->offset = 0;
449	cmd->state = NVMET_TCP_SEND_R2T;
450
451	pdu->hdr.type = nvme_tcp_r2t;
452	pdu->hdr.flags = 0;
453	pdu->hdr.hlen = sizeof(*pdu);
454	pdu->hdr.pdo = 0;
455	pdu->hdr.plen = cpu_to_le32(pdu->hdr.hlen + hdgst);
456
457	pdu->command_id = cmd->req.cmd->common.command_id;
458	pdu->ttag = nvmet_tcp_cmd_tag(cmd->queue, cmd);
459	pdu->r2t_length = cpu_to_le32(cmd->req.transfer_len - cmd->rbytes_done);
460	pdu->r2t_offset = cpu_to_le32(cmd->rbytes_done);
461	if (cmd->queue->hdr_digest) {
462		pdu->hdr.flags |= NVME_TCP_F_HDGST;
463		nvmet_tcp_hdgst(queue->snd_hash, pdu, sizeof(*pdu));
464	}
465}
466
467static void nvmet_setup_response_pdu(struct nvmet_tcp_cmd *cmd)
468{
469	struct nvme_tcp_rsp_pdu *pdu = cmd->rsp_pdu;
470	struct nvmet_tcp_queue *queue = cmd->queue;
471	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
472
473	cmd->offset = 0;
474	cmd->state = NVMET_TCP_SEND_RESPONSE;
475
476	pdu->hdr.type = nvme_tcp_rsp;
477	pdu->hdr.flags = 0;
478	pdu->hdr.hlen = sizeof(*pdu);
479	pdu->hdr.pdo = 0;
480	pdu->hdr.plen = cpu_to_le32(pdu->hdr.hlen + hdgst);
481	if (cmd->queue->hdr_digest) {
482		pdu->hdr.flags |= NVME_TCP_F_HDGST;
483		nvmet_tcp_hdgst(queue->snd_hash, pdu, sizeof(*pdu));
484	}
485}
486
487static void nvmet_tcp_process_resp_list(struct nvmet_tcp_queue *queue)
488{
489	struct llist_node *node;
490	struct nvmet_tcp_cmd *cmd;
491
492	for (node = llist_del_all(&queue->resp_list); node; node = node->next) {
493		cmd = llist_entry(node, struct nvmet_tcp_cmd, lentry);
494		list_add(&cmd->entry, &queue->resp_send_list);
495		queue->send_list_len++;
496	}
497}
498
499static struct nvmet_tcp_cmd *nvmet_tcp_fetch_cmd(struct nvmet_tcp_queue *queue)
500{
501	queue->snd_cmd = list_first_entry_or_null(&queue->resp_send_list,
502				struct nvmet_tcp_cmd, entry);
503	if (!queue->snd_cmd) {
504		nvmet_tcp_process_resp_list(queue);
505		queue->snd_cmd =
506			list_first_entry_or_null(&queue->resp_send_list,
507					struct nvmet_tcp_cmd, entry);
508		if (unlikely(!queue->snd_cmd))
509			return NULL;
510	}
511
512	list_del_init(&queue->snd_cmd->entry);
513	queue->send_list_len--;
514
515	if (nvmet_tcp_need_data_out(queue->snd_cmd))
516		nvmet_setup_c2h_data_pdu(queue->snd_cmd);
517	else if (nvmet_tcp_need_data_in(queue->snd_cmd))
518		nvmet_setup_r2t_pdu(queue->snd_cmd);
519	else
520		nvmet_setup_response_pdu(queue->snd_cmd);
521
522	return queue->snd_cmd;
523}
524
525static void nvmet_tcp_queue_response(struct nvmet_req *req)
526{
527	struct nvmet_tcp_cmd *cmd =
528		container_of(req, struct nvmet_tcp_cmd, req);
529	struct nvmet_tcp_queue	*queue = cmd->queue;
530	struct nvme_sgl_desc *sgl;
531	u32 len;
532
533	if (unlikely(cmd == queue->cmd)) {
534		sgl = &cmd->req.cmd->common.dptr.sgl;
535		len = le32_to_cpu(sgl->length);
536
537		/*
538		 * Wait for inline data before processing the response.
539		 * Avoid using helpers, this might happen before
540		 * nvmet_req_init is completed.
541		 */
542		if (queue->rcv_state == NVMET_TCP_RECV_PDU &&
543		    len && len <= cmd->req.port->inline_data_size &&
544		    nvme_is_write(cmd->req.cmd))
545			return;
546	}
547
548	llist_add(&cmd->lentry, &queue->resp_list);
549	queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &cmd->queue->io_work);
550}
551
552static void nvmet_tcp_execute_request(struct nvmet_tcp_cmd *cmd)
553{
554	if (unlikely(cmd->flags & NVMET_TCP_F_INIT_FAILED))
555		nvmet_tcp_queue_response(&cmd->req);
556	else
557		cmd->req.execute(&cmd->req);
558}
559
560static int nvmet_try_send_data_pdu(struct nvmet_tcp_cmd *cmd)
561{
562	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
563	int left = sizeof(*cmd->data_pdu) - cmd->offset + hdgst;
564	int ret;
565
566	ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->data_pdu),
567			offset_in_page(cmd->data_pdu) + cmd->offset,
568			left, MSG_DONTWAIT | MSG_MORE | MSG_SENDPAGE_NOTLAST);
569	if (ret <= 0)
570		return ret;
571
572	cmd->offset += ret;
573	left -= ret;
574
575	if (left)
576		return -EAGAIN;
577
578	cmd->state = NVMET_TCP_SEND_DATA;
579	cmd->offset  = 0;
580	return 1;
581}
582
583static int nvmet_try_send_data(struct nvmet_tcp_cmd *cmd, bool last_in_batch)
584{
585	struct nvmet_tcp_queue *queue = cmd->queue;
586	int ret;
587
588	while (cmd->cur_sg) {
589		struct page *page = sg_page(cmd->cur_sg);
590		u32 left = cmd->cur_sg->length - cmd->offset;
591		int flags = MSG_DONTWAIT;
592
593		if ((!last_in_batch && cmd->queue->send_list_len) ||
594		    cmd->wbytes_done + left < cmd->req.transfer_len ||
595		    queue->data_digest || !queue->nvme_sq.sqhd_disabled)
596			flags |= MSG_MORE | MSG_SENDPAGE_NOTLAST;
597
598		ret = kernel_sendpage(cmd->queue->sock, page, cmd->offset,
599					left, flags);
600		if (ret <= 0)
601			return ret;
602
603		cmd->offset += ret;
604		cmd->wbytes_done += ret;
605
606		/* Done with sg?*/
607		if (cmd->offset == cmd->cur_sg->length) {
608			cmd->cur_sg = sg_next(cmd->cur_sg);
609			cmd->offset = 0;
610		}
611	}
612
613	if (queue->data_digest) {
614		cmd->state = NVMET_TCP_SEND_DDGST;
615		cmd->offset = 0;
616	} else {
617		if (queue->nvme_sq.sqhd_disabled) {
618			cmd->queue->snd_cmd = NULL;
619			nvmet_tcp_put_cmd(cmd);
620		} else {
621			nvmet_setup_response_pdu(cmd);
622		}
623	}
624
625	if (queue->nvme_sq.sqhd_disabled) {
626		kfree(cmd->iov);
627		sgl_free(cmd->req.sg);
628	}
629
630	return 1;
631
632}
633
634static int nvmet_try_send_response(struct nvmet_tcp_cmd *cmd,
635		bool last_in_batch)
636{
637	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
638	int left = sizeof(*cmd->rsp_pdu) - cmd->offset + hdgst;
639	int flags = MSG_DONTWAIT;
640	int ret;
641
642	if (!last_in_batch && cmd->queue->send_list_len)
643		flags |= MSG_MORE | MSG_SENDPAGE_NOTLAST;
644	else
645		flags |= MSG_EOR;
646
647	ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->rsp_pdu),
648		offset_in_page(cmd->rsp_pdu) + cmd->offset, left, flags);
649	if (ret <= 0)
650		return ret;
651	cmd->offset += ret;
652	left -= ret;
653
654	if (left)
655		return -EAGAIN;
656
657	kfree(cmd->iov);
658	sgl_free(cmd->req.sg);
659	cmd->queue->snd_cmd = NULL;
660	nvmet_tcp_put_cmd(cmd);
661	return 1;
662}
663
664static int nvmet_try_send_r2t(struct nvmet_tcp_cmd *cmd, bool last_in_batch)
665{
666	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
667	int left = sizeof(*cmd->r2t_pdu) - cmd->offset + hdgst;
668	int flags = MSG_DONTWAIT;
669	int ret;
670
671	if (!last_in_batch && cmd->queue->send_list_len)
672		flags |= MSG_MORE | MSG_SENDPAGE_NOTLAST;
673	else
674		flags |= MSG_EOR;
675
676	ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->r2t_pdu),
677		offset_in_page(cmd->r2t_pdu) + cmd->offset, left, flags);
678	if (ret <= 0)
679		return ret;
680	cmd->offset += ret;
681	left -= ret;
682
683	if (left)
684		return -EAGAIN;
685
686	cmd->queue->snd_cmd = NULL;
687	return 1;
688}
689
690static int nvmet_try_send_ddgst(struct nvmet_tcp_cmd *cmd, bool last_in_batch)
691{
692	struct nvmet_tcp_queue *queue = cmd->queue;
693	int left = NVME_TCP_DIGEST_LENGTH - cmd->offset;
694	struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
695	struct kvec iov = {
696		.iov_base = (u8 *)&cmd->exp_ddgst + cmd->offset,
697		.iov_len = left
698	};
699	int ret;
700
701	if (!last_in_batch && cmd->queue->send_list_len)
702		msg.msg_flags |= MSG_MORE;
703	else
704		msg.msg_flags |= MSG_EOR;
705
706	ret = kernel_sendmsg(queue->sock, &msg, &iov, 1, iov.iov_len);
707	if (unlikely(ret <= 0))
708		return ret;
709
710	cmd->offset += ret;
711	left -= ret;
712
713	if (left)
714		return -EAGAIN;
715
716	if (queue->nvme_sq.sqhd_disabled) {
717		cmd->queue->snd_cmd = NULL;
718		nvmet_tcp_put_cmd(cmd);
719	} else {
720		nvmet_setup_response_pdu(cmd);
721	}
722	return 1;
723}
724
725static int nvmet_tcp_try_send_one(struct nvmet_tcp_queue *queue,
726		bool last_in_batch)
727{
728	struct nvmet_tcp_cmd *cmd = queue->snd_cmd;
729	int ret = 0;
730
731	if (!cmd || queue->state == NVMET_TCP_Q_DISCONNECTING) {
732		cmd = nvmet_tcp_fetch_cmd(queue);
733		if (unlikely(!cmd))
734			return 0;
735	}
736
737	if (cmd->state == NVMET_TCP_SEND_DATA_PDU) {
738		ret = nvmet_try_send_data_pdu(cmd);
739		if (ret <= 0)
740			goto done_send;
741	}
742
743	if (cmd->state == NVMET_TCP_SEND_DATA) {
744		ret = nvmet_try_send_data(cmd, last_in_batch);
745		if (ret <= 0)
746			goto done_send;
747	}
748
749	if (cmd->state == NVMET_TCP_SEND_DDGST) {
750		ret = nvmet_try_send_ddgst(cmd, last_in_batch);
751		if (ret <= 0)
752			goto done_send;
753	}
754
755	if (cmd->state == NVMET_TCP_SEND_R2T) {
756		ret = nvmet_try_send_r2t(cmd, last_in_batch);
757		if (ret <= 0)
758			goto done_send;
759	}
760
761	if (cmd->state == NVMET_TCP_SEND_RESPONSE)
762		ret = nvmet_try_send_response(cmd, last_in_batch);
763
764done_send:
765	if (ret < 0) {
766		if (ret == -EAGAIN)
767			return 0;
768		return ret;
769	}
770
771	return 1;
772}
773
774static int nvmet_tcp_try_send(struct nvmet_tcp_queue *queue,
775		int budget, int *sends)
776{
777	int i, ret = 0;
778
779	for (i = 0; i < budget; i++) {
780		ret = nvmet_tcp_try_send_one(queue, i == budget - 1);
781		if (unlikely(ret < 0)) {
782			nvmet_tcp_socket_error(queue, ret);
783			goto done;
784		} else if (ret == 0) {
785			break;
786		}
787		(*sends)++;
788	}
789done:
790	return ret;
791}
792
793static void nvmet_prepare_receive_pdu(struct nvmet_tcp_queue *queue)
794{
795	queue->offset = 0;
796	queue->left = sizeof(struct nvme_tcp_hdr);
797	queue->cmd = NULL;
798	queue->rcv_state = NVMET_TCP_RECV_PDU;
799}
800
801static void nvmet_tcp_free_crypto(struct nvmet_tcp_queue *queue)
802{
803	struct crypto_ahash *tfm = crypto_ahash_reqtfm(queue->rcv_hash);
804
805	ahash_request_free(queue->rcv_hash);
806	ahash_request_free(queue->snd_hash);
807	crypto_free_ahash(tfm);
808}
809
810static int nvmet_tcp_alloc_crypto(struct nvmet_tcp_queue *queue)
811{
812	struct crypto_ahash *tfm;
813
814	tfm = crypto_alloc_ahash("crc32c", 0, CRYPTO_ALG_ASYNC);
815	if (IS_ERR(tfm))
816		return PTR_ERR(tfm);
817
818	queue->snd_hash = ahash_request_alloc(tfm, GFP_KERNEL);
819	if (!queue->snd_hash)
820		goto free_tfm;
821	ahash_request_set_callback(queue->snd_hash, 0, NULL, NULL);
822
823	queue->rcv_hash = ahash_request_alloc(tfm, GFP_KERNEL);
824	if (!queue->rcv_hash)
825		goto free_snd_hash;
826	ahash_request_set_callback(queue->rcv_hash, 0, NULL, NULL);
827
828	return 0;
829free_snd_hash:
830	ahash_request_free(queue->snd_hash);
831free_tfm:
832	crypto_free_ahash(tfm);
833	return -ENOMEM;
834}
835
836
837static int nvmet_tcp_handle_icreq(struct nvmet_tcp_queue *queue)
838{
839	struct nvme_tcp_icreq_pdu *icreq = &queue->pdu.icreq;
840	struct nvme_tcp_icresp_pdu *icresp = &queue->pdu.icresp;
841	struct msghdr msg = {};
842	struct kvec iov;
843	int ret;
844
845	if (le32_to_cpu(icreq->hdr.plen) != sizeof(struct nvme_tcp_icreq_pdu)) {
846		pr_err("bad nvme-tcp pdu length (%d)\n",
847			le32_to_cpu(icreq->hdr.plen));
848		nvmet_tcp_fatal_error(queue);
849	}
850
851	if (icreq->pfv != NVME_TCP_PFV_1_0) {
852		pr_err("queue %d: bad pfv %d\n", queue->idx, icreq->pfv);
853		return -EPROTO;
854	}
855
856	if (icreq->hpda != 0) {
857		pr_err("queue %d: unsupported hpda %d\n", queue->idx,
858			icreq->hpda);
859		return -EPROTO;
860	}
861
862	queue->hdr_digest = !!(icreq->digest & NVME_TCP_HDR_DIGEST_ENABLE);
863	queue->data_digest = !!(icreq->digest & NVME_TCP_DATA_DIGEST_ENABLE);
864	if (queue->hdr_digest || queue->data_digest) {
865		ret = nvmet_tcp_alloc_crypto(queue);
866		if (ret)
867			return ret;
868	}
869
870	memset(icresp, 0, sizeof(*icresp));
871	icresp->hdr.type = nvme_tcp_icresp;
872	icresp->hdr.hlen = sizeof(*icresp);
873	icresp->hdr.pdo = 0;
874	icresp->hdr.plen = cpu_to_le32(icresp->hdr.hlen);
875	icresp->pfv = cpu_to_le16(NVME_TCP_PFV_1_0);
876	icresp->maxdata = cpu_to_le32(NVMET_TCP_MAXH2CDATA);
877	icresp->cpda = 0;
878	if (queue->hdr_digest)
879		icresp->digest |= NVME_TCP_HDR_DIGEST_ENABLE;
880	if (queue->data_digest)
881		icresp->digest |= NVME_TCP_DATA_DIGEST_ENABLE;
882
883	iov.iov_base = icresp;
884	iov.iov_len = sizeof(*icresp);
885	ret = kernel_sendmsg(queue->sock, &msg, &iov, 1, iov.iov_len);
886	if (ret < 0)
887		return ret; /* queue removal will cleanup */
888
889	queue->state = NVMET_TCP_Q_LIVE;
890	nvmet_prepare_receive_pdu(queue);
891	return 0;
892}
893
894static void nvmet_tcp_handle_req_failure(struct nvmet_tcp_queue *queue,
895		struct nvmet_tcp_cmd *cmd, struct nvmet_req *req)
896{
897	size_t data_len = le32_to_cpu(req->cmd->common.dptr.sgl.length);
898	int ret;
899
900	if (!nvme_is_write(cmd->req.cmd) ||
901	    data_len > cmd->req.port->inline_data_size) {
902		nvmet_prepare_receive_pdu(queue);
903		return;
904	}
905
906	ret = nvmet_tcp_map_data(cmd);
907	if (unlikely(ret)) {
908		pr_err("queue %d: failed to map data\n", queue->idx);
909		nvmet_tcp_fatal_error(queue);
910		return;
911	}
912
913	queue->rcv_state = NVMET_TCP_RECV_DATA;
914	nvmet_tcp_map_pdu_iovec(cmd);
915	cmd->flags |= NVMET_TCP_F_INIT_FAILED;
916}
917
918static int nvmet_tcp_handle_h2c_data_pdu(struct nvmet_tcp_queue *queue)
919{
920	struct nvme_tcp_data_pdu *data = &queue->pdu.data;
921	struct nvmet_tcp_cmd *cmd;
922	unsigned int exp_data_len;
923
924	if (likely(queue->nr_cmds)) {
925		if (unlikely(data->ttag >= queue->nr_cmds)) {
926			pr_err("queue %d: received out of bound ttag %u, nr_cmds %u\n",
927				queue->idx, data->ttag, queue->nr_cmds);
928			nvmet_tcp_fatal_error(queue);
929			return -EPROTO;
930		}
931		cmd = &queue->cmds[data->ttag];
932	} else {
933		cmd = &queue->connect;
934	}
935
936	if (le32_to_cpu(data->data_offset) != cmd->rbytes_done) {
937		pr_err("ttag %u unexpected data offset %u (expected %u)\n",
938			data->ttag, le32_to_cpu(data->data_offset),
939			cmd->rbytes_done);
940		/* FIXME: use path and transport errors */
941		nvmet_tcp_fatal_error(queue);
942		return -EPROTO;
943	}
944
945	exp_data_len = le32_to_cpu(data->hdr.plen) -
946			nvmet_tcp_hdgst_len(queue) -
947			nvmet_tcp_ddgst_len(queue) -
948			sizeof(*data);
949
950	cmd->pdu_len = le32_to_cpu(data->data_length);
951	if (unlikely(cmd->pdu_len != exp_data_len ||
952		     cmd->pdu_len == 0 ||
953		     cmd->pdu_len > NVMET_TCP_MAXH2CDATA)) {
954		pr_err("H2CData PDU len %u is invalid\n", cmd->pdu_len);
955		/* FIXME: use proper transport errors */
956		nvmet_tcp_fatal_error(queue);
957		return -EPROTO;
958	}
959	cmd->pdu_recv = 0;
960	nvmet_tcp_map_pdu_iovec(cmd);
961	queue->cmd = cmd;
962	queue->rcv_state = NVMET_TCP_RECV_DATA;
963
964	return 0;
965}
966
967static int nvmet_tcp_done_recv_pdu(struct nvmet_tcp_queue *queue)
968{
969	struct nvme_tcp_hdr *hdr = &queue->pdu.cmd.hdr;
970	struct nvme_command *nvme_cmd = &queue->pdu.cmd.cmd;
971	struct nvmet_req *req;
972	int ret;
973
974	if (unlikely(queue->state == NVMET_TCP_Q_CONNECTING)) {
975		if (hdr->type != nvme_tcp_icreq) {
976			pr_err("unexpected pdu type (%d) before icreq\n",
977				hdr->type);
978			nvmet_tcp_fatal_error(queue);
979			return -EPROTO;
980		}
981		return nvmet_tcp_handle_icreq(queue);
982	}
983
984	if (hdr->type == nvme_tcp_h2c_data) {
985		ret = nvmet_tcp_handle_h2c_data_pdu(queue);
986		if (unlikely(ret))
987			return ret;
988		return 0;
989	}
990
991	queue->cmd = nvmet_tcp_get_cmd(queue);
992	if (unlikely(!queue->cmd)) {
993		/* This should never happen */
994		pr_err("queue %d: out of commands (%d) send_list_len: %d, opcode: %d",
995			queue->idx, queue->nr_cmds, queue->send_list_len,
996			nvme_cmd->common.opcode);
997		nvmet_tcp_fatal_error(queue);
998		return -ENOMEM;
999	}
1000
1001	req = &queue->cmd->req;
1002	memcpy(req->cmd, nvme_cmd, sizeof(*nvme_cmd));
1003
1004	if (unlikely(!nvmet_req_init(req, &queue->nvme_cq,
1005			&queue->nvme_sq, &nvmet_tcp_ops))) {
1006		pr_err("failed cmd %p id %d opcode %d, data_len: %d\n",
1007			req->cmd, req->cmd->common.command_id,
1008			req->cmd->common.opcode,
1009			le32_to_cpu(req->cmd->common.dptr.sgl.length));
1010
1011		nvmet_tcp_handle_req_failure(queue, queue->cmd, req);
1012		return 0;
1013	}
1014
1015	ret = nvmet_tcp_map_data(queue->cmd);
1016	if (unlikely(ret)) {
1017		pr_err("queue %d: failed to map data\n", queue->idx);
1018		if (nvmet_tcp_has_inline_data(queue->cmd))
1019			nvmet_tcp_fatal_error(queue);
1020		else
1021			nvmet_req_complete(req, ret);
1022		ret = -EAGAIN;
1023		goto out;
1024	}
1025
1026	if (nvmet_tcp_need_data_in(queue->cmd)) {
1027		if (nvmet_tcp_has_inline_data(queue->cmd)) {
1028			queue->rcv_state = NVMET_TCP_RECV_DATA;
1029			nvmet_tcp_map_pdu_iovec(queue->cmd);
1030			return 0;
1031		}
1032		/* send back R2T */
1033		nvmet_tcp_queue_response(&queue->cmd->req);
1034		goto out;
1035	}
1036
1037	queue->cmd->req.execute(&queue->cmd->req);
1038out:
1039	nvmet_prepare_receive_pdu(queue);
1040	return ret;
1041}
1042
1043static const u8 nvme_tcp_pdu_sizes[] = {
1044	[nvme_tcp_icreq]	= sizeof(struct nvme_tcp_icreq_pdu),
1045	[nvme_tcp_cmd]		= sizeof(struct nvme_tcp_cmd_pdu),
1046	[nvme_tcp_h2c_data]	= sizeof(struct nvme_tcp_data_pdu),
1047};
1048
1049static inline u8 nvmet_tcp_pdu_size(u8 type)
1050{
1051	size_t idx = type;
1052
1053	return (idx < ARRAY_SIZE(nvme_tcp_pdu_sizes) &&
1054		nvme_tcp_pdu_sizes[idx]) ?
1055			nvme_tcp_pdu_sizes[idx] : 0;
1056}
1057
1058static inline bool nvmet_tcp_pdu_valid(u8 type)
1059{
1060	switch (type) {
1061	case nvme_tcp_icreq:
1062	case nvme_tcp_cmd:
1063	case nvme_tcp_h2c_data:
1064		/* fallthru */
1065		return true;
1066	}
1067
1068	return false;
1069}
1070
1071static int nvmet_tcp_try_recv_pdu(struct nvmet_tcp_queue *queue)
1072{
1073	struct nvme_tcp_hdr *hdr = &queue->pdu.cmd.hdr;
1074	int len;
1075	struct kvec iov;
1076	struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
1077
1078recv:
1079	iov.iov_base = (void *)&queue->pdu + queue->offset;
1080	iov.iov_len = queue->left;
1081	len = kernel_recvmsg(queue->sock, &msg, &iov, 1,
1082			iov.iov_len, msg.msg_flags);
1083	if (unlikely(len < 0))
1084		return len;
1085
1086	queue->offset += len;
1087	queue->left -= len;
1088	if (queue->left)
1089		return -EAGAIN;
1090
1091	if (queue->offset == sizeof(struct nvme_tcp_hdr)) {
1092		u8 hdgst = nvmet_tcp_hdgst_len(queue);
1093
1094		if (unlikely(!nvmet_tcp_pdu_valid(hdr->type))) {
1095			pr_err("unexpected pdu type %d\n", hdr->type);
1096			nvmet_tcp_fatal_error(queue);
1097			return -EIO;
1098		}
1099
1100		if (unlikely(hdr->hlen != nvmet_tcp_pdu_size(hdr->type))) {
1101			pr_err("pdu %d bad hlen %d\n", hdr->type, hdr->hlen);
1102			return -EIO;
1103		}
1104
1105		queue->left = hdr->hlen - queue->offset + hdgst;
1106		goto recv;
1107	}
1108
1109	if (queue->hdr_digest &&
1110	    nvmet_tcp_verify_hdgst(queue, &queue->pdu, hdr->hlen)) {
1111		nvmet_tcp_fatal_error(queue); /* fatal */
1112		return -EPROTO;
1113	}
1114
1115	if (queue->data_digest &&
1116	    nvmet_tcp_check_ddgst(queue, &queue->pdu)) {
1117		nvmet_tcp_fatal_error(queue); /* fatal */
1118		return -EPROTO;
1119	}
1120
1121	return nvmet_tcp_done_recv_pdu(queue);
1122}
1123
1124static void nvmet_tcp_prep_recv_ddgst(struct nvmet_tcp_cmd *cmd)
1125{
1126	struct nvmet_tcp_queue *queue = cmd->queue;
1127
1128	nvmet_tcp_recv_ddgst(queue->rcv_hash, cmd);
1129	queue->offset = 0;
1130	queue->left = NVME_TCP_DIGEST_LENGTH;
1131	queue->rcv_state = NVMET_TCP_RECV_DDGST;
1132}
1133
1134static int nvmet_tcp_try_recv_data(struct nvmet_tcp_queue *queue)
1135{
1136	struct nvmet_tcp_cmd  *cmd = queue->cmd;
1137	int ret;
1138
1139	while (msg_data_left(&cmd->recv_msg)) {
1140		ret = sock_recvmsg(cmd->queue->sock, &cmd->recv_msg,
1141			cmd->recv_msg.msg_flags);
1142		if (ret <= 0)
1143			return ret;
1144
1145		cmd->pdu_recv += ret;
1146		cmd->rbytes_done += ret;
1147	}
1148
1149	nvmet_tcp_unmap_pdu_iovec(cmd);
1150	if (queue->data_digest) {
1151		nvmet_tcp_prep_recv_ddgst(cmd);
1152		return 0;
1153	}
1154
1155	if (cmd->rbytes_done == cmd->req.transfer_len)
1156		nvmet_tcp_execute_request(cmd);
1157
1158	nvmet_prepare_receive_pdu(queue);
1159	return 0;
1160}
1161
1162static int nvmet_tcp_try_recv_ddgst(struct nvmet_tcp_queue *queue)
1163{
1164	struct nvmet_tcp_cmd *cmd = queue->cmd;
1165	int ret;
1166	struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
1167	struct kvec iov = {
1168		.iov_base = (void *)&cmd->recv_ddgst + queue->offset,
1169		.iov_len = queue->left
1170	};
1171
1172	ret = kernel_recvmsg(queue->sock, &msg, &iov, 1,
1173			iov.iov_len, msg.msg_flags);
1174	if (unlikely(ret < 0))
1175		return ret;
1176
1177	queue->offset += ret;
1178	queue->left -= ret;
1179	if (queue->left)
1180		return -EAGAIN;
1181
1182	if (queue->data_digest && cmd->exp_ddgst != cmd->recv_ddgst) {
1183		pr_err("queue %d: cmd %d pdu (%d) data digest error: recv %#x expected %#x\n",
1184			queue->idx, cmd->req.cmd->common.command_id,
1185			queue->pdu.cmd.hdr.type, le32_to_cpu(cmd->recv_ddgst),
1186			le32_to_cpu(cmd->exp_ddgst));
1187		nvmet_tcp_finish_cmd(cmd);
1188		nvmet_tcp_fatal_error(queue);
1189		ret = -EPROTO;
1190		goto out;
1191	}
1192
1193	if (cmd->rbytes_done == cmd->req.transfer_len)
1194		nvmet_tcp_execute_request(cmd);
1195
1196	ret = 0;
1197out:
1198	nvmet_prepare_receive_pdu(queue);
1199	return ret;
1200}
1201
1202static int nvmet_tcp_try_recv_one(struct nvmet_tcp_queue *queue)
1203{
1204	int result = 0;
1205
1206	if (unlikely(queue->rcv_state == NVMET_TCP_RECV_ERR))
1207		return 0;
1208
1209	if (queue->rcv_state == NVMET_TCP_RECV_PDU) {
1210		result = nvmet_tcp_try_recv_pdu(queue);
1211		if (result != 0)
1212			goto done_recv;
1213	}
1214
1215	if (queue->rcv_state == NVMET_TCP_RECV_DATA) {
1216		result = nvmet_tcp_try_recv_data(queue);
1217		if (result != 0)
1218			goto done_recv;
1219	}
1220
1221	if (queue->rcv_state == NVMET_TCP_RECV_DDGST) {
1222		result = nvmet_tcp_try_recv_ddgst(queue);
1223		if (result != 0)
1224			goto done_recv;
1225	}
1226
1227done_recv:
1228	if (result < 0) {
1229		if (result == -EAGAIN)
1230			return 0;
1231		return result;
1232	}
1233	return 1;
1234}
1235
1236static int nvmet_tcp_try_recv(struct nvmet_tcp_queue *queue,
1237		int budget, int *recvs)
1238{
1239	int i, ret = 0;
1240
1241	for (i = 0; i < budget; i++) {
1242		ret = nvmet_tcp_try_recv_one(queue);
1243		if (unlikely(ret < 0)) {
1244			nvmet_tcp_socket_error(queue, ret);
1245			goto done;
1246		} else if (ret == 0) {
1247			break;
1248		}
1249		(*recvs)++;
1250	}
1251done:
1252	return ret;
1253}
1254
1255static void nvmet_tcp_schedule_release_queue(struct nvmet_tcp_queue *queue)
1256{
1257	spin_lock(&queue->state_lock);
1258	if (queue->state != NVMET_TCP_Q_DISCONNECTING) {
1259		queue->state = NVMET_TCP_Q_DISCONNECTING;
1260		schedule_work(&queue->release_work);
1261	}
1262	spin_unlock(&queue->state_lock);
1263}
1264
1265static void nvmet_tcp_io_work(struct work_struct *w)
1266{
1267	struct nvmet_tcp_queue *queue =
1268		container_of(w, struct nvmet_tcp_queue, io_work);
1269	bool pending;
1270	int ret, ops = 0;
1271
1272	do {
1273		pending = false;
1274
1275		ret = nvmet_tcp_try_recv(queue, NVMET_TCP_RECV_BUDGET, &ops);
1276		if (ret > 0)
1277			pending = true;
1278		else if (ret < 0)
1279			return;
1280
1281		ret = nvmet_tcp_try_send(queue, NVMET_TCP_SEND_BUDGET, &ops);
1282		if (ret > 0)
1283			pending = true;
1284		else if (ret < 0)
1285			return;
1286
1287	} while (pending && ops < NVMET_TCP_IO_WORK_BUDGET);
1288
1289	/*
1290	 * We exahusted our budget, requeue our selves
1291	 */
1292	if (pending)
1293		queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &queue->io_work);
1294}
1295
1296static int nvmet_tcp_alloc_cmd(struct nvmet_tcp_queue *queue,
1297		struct nvmet_tcp_cmd *c)
1298{
1299	u8 hdgst = nvmet_tcp_hdgst_len(queue);
1300
1301	c->queue = queue;
1302	c->req.port = queue->port->nport;
1303
1304	c->cmd_pdu = page_frag_alloc(&queue->pf_cache,
1305			sizeof(*c->cmd_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1306	if (!c->cmd_pdu)
1307		return -ENOMEM;
1308	c->req.cmd = &c->cmd_pdu->cmd;
1309
1310	c->rsp_pdu = page_frag_alloc(&queue->pf_cache,
1311			sizeof(*c->rsp_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1312	if (!c->rsp_pdu)
1313		goto out_free_cmd;
1314	c->req.cqe = &c->rsp_pdu->cqe;
1315
1316	c->data_pdu = page_frag_alloc(&queue->pf_cache,
1317			sizeof(*c->data_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1318	if (!c->data_pdu)
1319		goto out_free_rsp;
1320
1321	c->r2t_pdu = page_frag_alloc(&queue->pf_cache,
1322			sizeof(*c->r2t_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1323	if (!c->r2t_pdu)
1324		goto out_free_data;
1325
1326	c->recv_msg.msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
1327
1328	list_add_tail(&c->entry, &queue->free_list);
1329
1330	return 0;
1331out_free_data:
1332	page_frag_free(c->data_pdu);
1333out_free_rsp:
1334	page_frag_free(c->rsp_pdu);
1335out_free_cmd:
1336	page_frag_free(c->cmd_pdu);
1337	return -ENOMEM;
1338}
1339
1340static void nvmet_tcp_free_cmd(struct nvmet_tcp_cmd *c)
1341{
1342	page_frag_free(c->r2t_pdu);
1343	page_frag_free(c->data_pdu);
1344	page_frag_free(c->rsp_pdu);
1345	page_frag_free(c->cmd_pdu);
1346}
1347
1348static int nvmet_tcp_alloc_cmds(struct nvmet_tcp_queue *queue)
1349{
1350	struct nvmet_tcp_cmd *cmds;
1351	int i, ret = -EINVAL, nr_cmds = queue->nr_cmds;
1352
1353	cmds = kcalloc(nr_cmds, sizeof(struct nvmet_tcp_cmd), GFP_KERNEL);
1354	if (!cmds)
1355		goto out;
1356
1357	for (i = 0; i < nr_cmds; i++) {
1358		ret = nvmet_tcp_alloc_cmd(queue, cmds + i);
1359		if (ret)
1360			goto out_free;
1361	}
1362
1363	queue->cmds = cmds;
1364
1365	return 0;
1366out_free:
1367	while (--i >= 0)
1368		nvmet_tcp_free_cmd(cmds + i);
1369	kfree(cmds);
1370out:
1371	return ret;
1372}
1373
1374static void nvmet_tcp_free_cmds(struct nvmet_tcp_queue *queue)
1375{
1376	struct nvmet_tcp_cmd *cmds = queue->cmds;
1377	int i;
1378
1379	for (i = 0; i < queue->nr_cmds; i++)
1380		nvmet_tcp_free_cmd(cmds + i);
1381
1382	nvmet_tcp_free_cmd(&queue->connect);
1383	kfree(cmds);
1384}
1385
1386static void nvmet_tcp_restore_socket_callbacks(struct nvmet_tcp_queue *queue)
1387{
1388	struct socket *sock = queue->sock;
1389
1390	write_lock_bh(&sock->sk->sk_callback_lock);
1391	sock->sk->sk_data_ready =  queue->data_ready;
1392	sock->sk->sk_state_change = queue->state_change;
1393	sock->sk->sk_write_space = queue->write_space;
1394	sock->sk->sk_user_data = NULL;
1395	write_unlock_bh(&sock->sk->sk_callback_lock);
1396}
1397
1398static void nvmet_tcp_finish_cmd(struct nvmet_tcp_cmd *cmd)
1399{
1400	nvmet_req_uninit(&cmd->req);
1401	nvmet_tcp_unmap_pdu_iovec(cmd);
1402	kfree(cmd->iov);
1403	sgl_free(cmd->req.sg);
1404}
1405
1406static void nvmet_tcp_uninit_data_in_cmds(struct nvmet_tcp_queue *queue)
1407{
1408	struct nvmet_tcp_cmd *cmd = queue->cmds;
1409	int i;
1410
1411	for (i = 0; i < queue->nr_cmds; i++, cmd++) {
1412		if (nvmet_tcp_need_data_in(cmd))
1413			nvmet_tcp_finish_cmd(cmd);
1414	}
1415
1416	if (!queue->nr_cmds && nvmet_tcp_need_data_in(&queue->connect)) {
1417		/* failed in connect */
1418		nvmet_tcp_finish_cmd(&queue->connect);
1419	}
1420}
1421
1422static void nvmet_tcp_release_queue_work(struct work_struct *w)
1423{
1424	struct page *page;
1425	struct nvmet_tcp_queue *queue =
1426		container_of(w, struct nvmet_tcp_queue, release_work);
1427
1428	mutex_lock(&nvmet_tcp_queue_mutex);
1429	list_del_init(&queue->queue_list);
1430	mutex_unlock(&nvmet_tcp_queue_mutex);
1431
1432	nvmet_tcp_restore_socket_callbacks(queue);
1433	flush_work(&queue->io_work);
1434
1435	nvmet_tcp_uninit_data_in_cmds(queue);
1436	nvmet_sq_destroy(&queue->nvme_sq);
1437	cancel_work_sync(&queue->io_work);
1438	sock_release(queue->sock);
1439	nvmet_tcp_free_cmds(queue);
1440	if (queue->hdr_digest || queue->data_digest)
1441		nvmet_tcp_free_crypto(queue);
1442	ida_simple_remove(&nvmet_tcp_queue_ida, queue->idx);
1443
1444	page = virt_to_head_page(queue->pf_cache.va);
1445	__page_frag_cache_drain(page, queue->pf_cache.pagecnt_bias);
1446	kfree(queue);
1447}
1448
1449static void nvmet_tcp_data_ready(struct sock *sk)
1450{
1451	struct nvmet_tcp_queue *queue;
1452
1453	read_lock_bh(&sk->sk_callback_lock);
1454	queue = sk->sk_user_data;
1455	if (likely(queue))
1456		queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &queue->io_work);
1457	read_unlock_bh(&sk->sk_callback_lock);
1458}
1459
1460static void nvmet_tcp_write_space(struct sock *sk)
1461{
1462	struct nvmet_tcp_queue *queue;
1463
1464	read_lock_bh(&sk->sk_callback_lock);
1465	queue = sk->sk_user_data;
1466	if (unlikely(!queue))
1467		goto out;
1468
1469	if (unlikely(queue->state == NVMET_TCP_Q_CONNECTING)) {
1470		queue->write_space(sk);
1471		goto out;
1472	}
1473
1474	if (sk_stream_is_writeable(sk)) {
1475		clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1476		queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &queue->io_work);
1477	}
1478out:
1479	read_unlock_bh(&sk->sk_callback_lock);
1480}
1481
1482static void nvmet_tcp_state_change(struct sock *sk)
1483{
1484	struct nvmet_tcp_queue *queue;
1485
1486	read_lock_bh(&sk->sk_callback_lock);
1487	queue = sk->sk_user_data;
1488	if (!queue)
1489		goto done;
1490
1491	switch (sk->sk_state) {
1492	case TCP_FIN_WAIT2:
1493	case TCP_LAST_ACK:
1494		break;
1495	case TCP_FIN_WAIT1:
1496	case TCP_CLOSE_WAIT:
1497	case TCP_CLOSE:
1498		/* FALLTHRU */
1499		nvmet_tcp_schedule_release_queue(queue);
1500		break;
1501	default:
1502		pr_warn("queue %d unhandled state %d\n",
1503			queue->idx, sk->sk_state);
1504	}
1505done:
1506	read_unlock_bh(&sk->sk_callback_lock);
1507}
1508
1509static int nvmet_tcp_set_queue_sock(struct nvmet_tcp_queue *queue)
1510{
1511	struct socket *sock = queue->sock;
1512	struct inet_sock *inet = inet_sk(sock->sk);
1513	int ret;
1514
1515	ret = kernel_getsockname(sock,
1516		(struct sockaddr *)&queue->sockaddr);
1517	if (ret < 0)
1518		return ret;
1519
1520	ret = kernel_getpeername(sock,
1521		(struct sockaddr *)&queue->sockaddr_peer);
1522	if (ret < 0)
1523		return ret;
1524
1525	/*
1526	 * Cleanup whatever is sitting in the TCP transmit queue on socket
1527	 * close. This is done to prevent stale data from being sent should
1528	 * the network connection be restored before TCP times out.
1529	 */
1530	sock_no_linger(sock->sk);
1531
1532	if (so_priority > 0)
1533		sock_set_priority(sock->sk, so_priority);
1534
1535	/* Set socket type of service */
1536	if (inet->rcv_tos > 0)
1537		ip_sock_set_tos(sock->sk, inet->rcv_tos);
1538
1539	ret = 0;
1540	write_lock_bh(&sock->sk->sk_callback_lock);
1541	if (sock->sk->sk_state != TCP_ESTABLISHED) {
1542		/*
1543		 * If the socket is already closing, don't even start
1544		 * consuming it
1545		 */
1546		ret = -ENOTCONN;
1547	} else {
1548		sock->sk->sk_user_data = queue;
1549		queue->data_ready = sock->sk->sk_data_ready;
1550		sock->sk->sk_data_ready = nvmet_tcp_data_ready;
1551		queue->state_change = sock->sk->sk_state_change;
1552		sock->sk->sk_state_change = nvmet_tcp_state_change;
1553		queue->write_space = sock->sk->sk_write_space;
1554		sock->sk->sk_write_space = nvmet_tcp_write_space;
1555		queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &queue->io_work);
1556	}
1557	write_unlock_bh(&sock->sk->sk_callback_lock);
1558
1559	return ret;
1560}
1561
1562static int nvmet_tcp_alloc_queue(struct nvmet_tcp_port *port,
1563		struct socket *newsock)
1564{
1565	struct nvmet_tcp_queue *queue;
1566	int ret;
1567
1568	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
1569	if (!queue)
1570		return -ENOMEM;
1571
1572	INIT_WORK(&queue->release_work, nvmet_tcp_release_queue_work);
1573	INIT_WORK(&queue->io_work, nvmet_tcp_io_work);
1574	queue->sock = newsock;
1575	queue->port = port;
1576	queue->nr_cmds = 0;
1577	spin_lock_init(&queue->state_lock);
1578	queue->state = NVMET_TCP_Q_CONNECTING;
1579	INIT_LIST_HEAD(&queue->free_list);
1580	init_llist_head(&queue->resp_list);
1581	INIT_LIST_HEAD(&queue->resp_send_list);
1582
1583	queue->idx = ida_simple_get(&nvmet_tcp_queue_ida, 0, 0, GFP_KERNEL);
1584	if (queue->idx < 0) {
1585		ret = queue->idx;
1586		goto out_free_queue;
1587	}
1588
1589	ret = nvmet_tcp_alloc_cmd(queue, &queue->connect);
1590	if (ret)
1591		goto out_ida_remove;
1592
1593	ret = nvmet_sq_init(&queue->nvme_sq);
1594	if (ret)
1595		goto out_free_connect;
1596
1597	nvmet_prepare_receive_pdu(queue);
1598
1599	mutex_lock(&nvmet_tcp_queue_mutex);
1600	list_add_tail(&queue->queue_list, &nvmet_tcp_queue_list);
1601	mutex_unlock(&nvmet_tcp_queue_mutex);
1602
1603	ret = nvmet_tcp_set_queue_sock(queue);
1604	if (ret)
1605		goto out_destroy_sq;
1606
1607	return 0;
1608out_destroy_sq:
1609	mutex_lock(&nvmet_tcp_queue_mutex);
1610	list_del_init(&queue->queue_list);
1611	mutex_unlock(&nvmet_tcp_queue_mutex);
1612	nvmet_sq_destroy(&queue->nvme_sq);
1613out_free_connect:
1614	nvmet_tcp_free_cmd(&queue->connect);
1615out_ida_remove:
1616	ida_simple_remove(&nvmet_tcp_queue_ida, queue->idx);
1617out_free_queue:
1618	kfree(queue);
1619	return ret;
1620}
1621
1622static void nvmet_tcp_accept_work(struct work_struct *w)
1623{
1624	struct nvmet_tcp_port *port =
1625		container_of(w, struct nvmet_tcp_port, accept_work);
1626	struct socket *newsock;
1627	int ret;
1628
1629	while (true) {
1630		ret = kernel_accept(port->sock, &newsock, O_NONBLOCK);
1631		if (ret < 0) {
1632			if (ret != -EAGAIN)
1633				pr_warn("failed to accept err=%d\n", ret);
1634			return;
1635		}
1636		ret = nvmet_tcp_alloc_queue(port, newsock);
1637		if (ret) {
1638			pr_err("failed to allocate queue\n");
1639			sock_release(newsock);
1640		}
1641	}
1642}
1643
1644static void nvmet_tcp_listen_data_ready(struct sock *sk)
1645{
1646	struct nvmet_tcp_port *port;
1647
1648	read_lock_bh(&sk->sk_callback_lock);
1649	port = sk->sk_user_data;
1650	if (!port)
1651		goto out;
1652
1653	if (sk->sk_state == TCP_LISTEN)
1654		schedule_work(&port->accept_work);
1655out:
1656	read_unlock_bh(&sk->sk_callback_lock);
1657}
1658
1659static int nvmet_tcp_add_port(struct nvmet_port *nport)
1660{
1661	struct nvmet_tcp_port *port;
1662	__kernel_sa_family_t af;
1663	int ret;
1664
1665	port = kzalloc(sizeof(*port), GFP_KERNEL);
1666	if (!port)
1667		return -ENOMEM;
1668
1669	switch (nport->disc_addr.adrfam) {
1670	case NVMF_ADDR_FAMILY_IP4:
1671		af = AF_INET;
1672		break;
1673	case NVMF_ADDR_FAMILY_IP6:
1674		af = AF_INET6;
1675		break;
1676	default:
1677		pr_err("address family %d not supported\n",
1678				nport->disc_addr.adrfam);
1679		ret = -EINVAL;
1680		goto err_port;
1681	}
1682
1683	ret = inet_pton_with_scope(&init_net, af, nport->disc_addr.traddr,
1684			nport->disc_addr.trsvcid, &port->addr);
1685	if (ret) {
1686		pr_err("malformed ip/port passed: %s:%s\n",
1687			nport->disc_addr.traddr, nport->disc_addr.trsvcid);
1688		goto err_port;
1689	}
1690
1691	port->nport = nport;
1692	INIT_WORK(&port->accept_work, nvmet_tcp_accept_work);
1693	if (port->nport->inline_data_size < 0)
1694		port->nport->inline_data_size = NVMET_TCP_DEF_INLINE_DATA_SIZE;
1695
1696	ret = sock_create(port->addr.ss_family, SOCK_STREAM,
1697				IPPROTO_TCP, &port->sock);
1698	if (ret) {
1699		pr_err("failed to create a socket\n");
1700		goto err_port;
1701	}
1702
1703	port->sock->sk->sk_user_data = port;
1704	port->data_ready = port->sock->sk->sk_data_ready;
1705	port->sock->sk->sk_data_ready = nvmet_tcp_listen_data_ready;
1706	sock_set_reuseaddr(port->sock->sk);
1707	tcp_sock_set_nodelay(port->sock->sk);
1708	if (so_priority > 0)
1709		sock_set_priority(port->sock->sk, so_priority);
1710
1711	ret = kernel_bind(port->sock, (struct sockaddr *)&port->addr,
1712			sizeof(port->addr));
1713	if (ret) {
1714		pr_err("failed to bind port socket %d\n", ret);
1715		goto err_sock;
1716	}
1717
1718	ret = kernel_listen(port->sock, 128);
1719	if (ret) {
1720		pr_err("failed to listen %d on port sock\n", ret);
1721		goto err_sock;
1722	}
1723
1724	nport->priv = port;
1725	pr_info("enabling port %d (%pISpc)\n",
1726		le16_to_cpu(nport->disc_addr.portid), &port->addr);
1727
1728	return 0;
1729
1730err_sock:
1731	sock_release(port->sock);
1732err_port:
1733	kfree(port);
1734	return ret;
1735}
1736
1737static void nvmet_tcp_destroy_port_queues(struct nvmet_tcp_port *port)
1738{
1739	struct nvmet_tcp_queue *queue;
1740
1741	mutex_lock(&nvmet_tcp_queue_mutex);
1742	list_for_each_entry(queue, &nvmet_tcp_queue_list, queue_list)
1743		if (queue->port == port)
1744			kernel_sock_shutdown(queue->sock, SHUT_RDWR);
1745	mutex_unlock(&nvmet_tcp_queue_mutex);
1746}
1747
1748static void nvmet_tcp_remove_port(struct nvmet_port *nport)
1749{
1750	struct nvmet_tcp_port *port = nport->priv;
1751
1752	write_lock_bh(&port->sock->sk->sk_callback_lock);
1753	port->sock->sk->sk_data_ready = port->data_ready;
1754	port->sock->sk->sk_user_data = NULL;
1755	write_unlock_bh(&port->sock->sk->sk_callback_lock);
1756	cancel_work_sync(&port->accept_work);
1757	/*
1758	 * Destroy the remaining queues, which are not belong to any
1759	 * controller yet.
1760	 */
1761	nvmet_tcp_destroy_port_queues(port);
1762
1763	sock_release(port->sock);
1764	kfree(port);
1765}
1766
1767static void nvmet_tcp_delete_ctrl(struct nvmet_ctrl *ctrl)
1768{
1769	struct nvmet_tcp_queue *queue;
1770
1771	mutex_lock(&nvmet_tcp_queue_mutex);
1772	list_for_each_entry(queue, &nvmet_tcp_queue_list, queue_list)
1773		if (queue->nvme_sq.ctrl == ctrl)
1774			kernel_sock_shutdown(queue->sock, SHUT_RDWR);
1775	mutex_unlock(&nvmet_tcp_queue_mutex);
1776}
1777
1778static u16 nvmet_tcp_install_queue(struct nvmet_sq *sq)
1779{
1780	struct nvmet_tcp_queue *queue =
1781		container_of(sq, struct nvmet_tcp_queue, nvme_sq);
1782
1783	if (sq->qid == 0) {
1784		/* Let inflight controller teardown complete */
1785		flush_scheduled_work();
1786	}
1787
1788	queue->nr_cmds = sq->size * 2;
1789	if (nvmet_tcp_alloc_cmds(queue)) {
1790		queue->nr_cmds = 0;
1791		return NVME_SC_INTERNAL;
1792	}
1793	return 0;
1794}
1795
1796static void nvmet_tcp_disc_port_addr(struct nvmet_req *req,
1797		struct nvmet_port *nport, char *traddr)
1798{
1799	struct nvmet_tcp_port *port = nport->priv;
1800
1801	if (inet_addr_is_any((struct sockaddr *)&port->addr)) {
1802		struct nvmet_tcp_cmd *cmd =
1803			container_of(req, struct nvmet_tcp_cmd, req);
1804		struct nvmet_tcp_queue *queue = cmd->queue;
1805
1806		sprintf(traddr, "%pISc", (struct sockaddr *)&queue->sockaddr);
1807	} else {
1808		memcpy(traddr, nport->disc_addr.traddr, NVMF_TRADDR_SIZE);
1809	}
1810}
1811
1812static const struct nvmet_fabrics_ops nvmet_tcp_ops = {
1813	.owner			= THIS_MODULE,
1814	.type			= NVMF_TRTYPE_TCP,
1815	.msdbd			= 1,
1816	.add_port		= nvmet_tcp_add_port,
1817	.remove_port		= nvmet_tcp_remove_port,
1818	.queue_response		= nvmet_tcp_queue_response,
1819	.delete_ctrl		= nvmet_tcp_delete_ctrl,
1820	.install_queue		= nvmet_tcp_install_queue,
1821	.disc_traddr		= nvmet_tcp_disc_port_addr,
1822};
1823
1824static int __init nvmet_tcp_init(void)
1825{
1826	int ret;
1827
1828	nvmet_tcp_wq = alloc_workqueue("nvmet_tcp_wq",
1829				WQ_MEM_RECLAIM | WQ_HIGHPRI, 0);
1830	if (!nvmet_tcp_wq)
1831		return -ENOMEM;
1832
1833	ret = nvmet_register_transport(&nvmet_tcp_ops);
1834	if (ret)
1835		goto err;
1836
1837	return 0;
1838err:
1839	destroy_workqueue(nvmet_tcp_wq);
1840	return ret;
1841}
1842
1843static void __exit nvmet_tcp_exit(void)
1844{
1845	struct nvmet_tcp_queue *queue;
1846
1847	nvmet_unregister_transport(&nvmet_tcp_ops);
1848
1849	flush_scheduled_work();
1850	mutex_lock(&nvmet_tcp_queue_mutex);
1851	list_for_each_entry(queue, &nvmet_tcp_queue_list, queue_list)
1852		kernel_sock_shutdown(queue->sock, SHUT_RDWR);
1853	mutex_unlock(&nvmet_tcp_queue_mutex);
1854	flush_scheduled_work();
1855
1856	destroy_workqueue(nvmet_tcp_wq);
1857}
1858
1859module_init(nvmet_tcp_init);
1860module_exit(nvmet_tcp_exit);
1861
1862MODULE_LICENSE("GPL v2");
1863MODULE_ALIAS("nvmet-transport-3"); /* 3 == NVMF_TRTYPE_TCP */
1864