xref: /spdk/module/sock/posix/posix.c (revision 8a6101458532c70e17ff48c2d48391f284a0fdd5)
1 /*   SPDX-License-Identifier: BSD-3-Clause
2  *   Copyright (C) 2018 Intel Corporation. All rights reserved.
3  *   Copyright (c) 2020, 2021 Mellanox Technologies LTD. All rights reserved.
4  *   Copyright (c) 2021 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
5  */
6 
7 #include "spdk/stdinc.h"
8 
9 #if defined(__FreeBSD__)
10 #include <sys/event.h>
11 #define SPDK_KEVENT
12 #else
13 #include <sys/epoll.h>
14 #define SPDK_EPOLL
15 #endif
16 
17 #if defined(__linux__)
18 #include <linux/errqueue.h>
19 #endif
20 
21 #include "spdk/env.h"
22 #include "spdk/log.h"
23 #include "spdk/pipe.h"
24 #include "spdk/sock.h"
25 #include "spdk/util.h"
26 #include "spdk/string.h"
27 #include "spdk_internal/sock.h"
28 #include "../sock_kernel.h"
29 
30 #include "openssl/crypto.h"
31 #include "openssl/err.h"
32 #include "openssl/ssl.h"
33 
34 #define MAX_TMPBUF 1024
35 #define PORTNUMLEN 32
36 
37 #if defined(SO_ZEROCOPY) && defined(MSG_ZEROCOPY)
38 #define SPDK_ZEROCOPY
39 #endif
40 
41 struct spdk_posix_sock {
42 	struct spdk_sock	base;
43 	int			fd;
44 
45 	uint32_t		sendmsg_idx;
46 
47 	struct spdk_pipe	*recv_pipe;
48 	int			recv_buf_sz;
49 	bool			pipe_has_data;
50 	bool			socket_has_data;
51 	bool			zcopy;
52 
53 	int			placement_id;
54 
55 	SSL_CTX			*ctx;
56 	SSL			*ssl;
57 
58 	TAILQ_ENTRY(spdk_posix_sock)	link;
59 };
60 
61 TAILQ_HEAD(spdk_has_data_list, spdk_posix_sock);
62 
63 struct spdk_posix_sock_group_impl {
64 	struct spdk_sock_group_impl	base;
65 	int				fd;
66 	struct spdk_interrupt		*intr;
67 	struct spdk_has_data_list	socks_with_data;
68 	int				placement_id;
69 	struct spdk_pipe_group		*pipe_group;
70 };
71 
72 static struct spdk_sock_impl_opts g_posix_impl_opts = {
73 	.recv_buf_size = DEFAULT_SO_RCVBUF_SIZE,
74 	.send_buf_size = DEFAULT_SO_SNDBUF_SIZE,
75 	.enable_recv_pipe = true,
76 	.enable_quickack = false,
77 	.enable_placement_id = PLACEMENT_NONE,
78 	.enable_zerocopy_send_server = true,
79 	.enable_zerocopy_send_client = false,
80 	.zerocopy_threshold = 0,
81 	.tls_version = 0,
82 	.enable_ktls = false,
83 	.psk_key = NULL,
84 	.psk_key_size = 0,
85 	.psk_identity = NULL,
86 	.get_key = NULL,
87 	.get_key_ctx = NULL,
88 	.tls_cipher_suites = NULL
89 };
90 
91 static struct spdk_sock_impl_opts g_ssl_impl_opts = {
92 	.recv_buf_size = MIN_SO_RCVBUF_SIZE,
93 	.send_buf_size = MIN_SO_SNDBUF_SIZE,
94 	.enable_recv_pipe = true,
95 	.enable_quickack = false,
96 	.enable_placement_id = PLACEMENT_NONE,
97 	.enable_zerocopy_send_server = true,
98 	.enable_zerocopy_send_client = false,
99 	.zerocopy_threshold = 0,
100 	.tls_version = 0,
101 	.enable_ktls = false,
102 	.psk_key = NULL,
103 	.psk_identity = NULL
104 };
105 
106 static struct spdk_sock_map g_map = {
107 	.entries = STAILQ_HEAD_INITIALIZER(g_map.entries),
108 	.mtx = PTHREAD_MUTEX_INITIALIZER
109 };
110 
111 __attribute((destructor)) static void
112 posix_sock_map_cleanup(void)
113 {
114 	spdk_sock_map_cleanup(&g_map);
115 }
116 
117 #define __posix_sock(sock) (struct spdk_posix_sock *)sock
118 #define __posix_group_impl(group) (struct spdk_posix_sock_group_impl *)group
119 
120 static void
121 posix_sock_copy_impl_opts(struct spdk_sock_impl_opts *dest, const struct spdk_sock_impl_opts *src,
122 			  size_t len)
123 {
124 #define FIELD_OK(field) \
125 	offsetof(struct spdk_sock_impl_opts, field) + sizeof(src->field) <= len
126 
127 #define SET_FIELD(field) \
128 	if (FIELD_OK(field)) { \
129 		dest->field = src->field; \
130 	}
131 
132 	SET_FIELD(recv_buf_size);
133 	SET_FIELD(send_buf_size);
134 	SET_FIELD(enable_recv_pipe);
135 	SET_FIELD(enable_zerocopy_send);
136 	SET_FIELD(enable_quickack);
137 	SET_FIELD(enable_placement_id);
138 	SET_FIELD(enable_zerocopy_send_server);
139 	SET_FIELD(enable_zerocopy_send_client);
140 	SET_FIELD(zerocopy_threshold);
141 	SET_FIELD(tls_version);
142 	SET_FIELD(enable_ktls);
143 	SET_FIELD(psk_key);
144 	SET_FIELD(psk_key_size);
145 	SET_FIELD(psk_identity);
146 	SET_FIELD(get_key);
147 	SET_FIELD(get_key_ctx);
148 	SET_FIELD(tls_cipher_suites);
149 
150 #undef SET_FIELD
151 #undef FIELD_OK
152 }
153 
154 static int
155 _sock_impl_get_opts(struct spdk_sock_impl_opts *opts, struct spdk_sock_impl_opts *impl_opts,
156 		    size_t *len)
157 {
158 	if (!opts || !len) {
159 		errno = EINVAL;
160 		return -1;
161 	}
162 
163 	assert(sizeof(*opts) >= *len);
164 	memset(opts, 0, *len);
165 
166 	posix_sock_copy_impl_opts(opts, impl_opts, *len);
167 	*len = spdk_min(*len, sizeof(*impl_opts));
168 
169 	return 0;
170 }
171 
172 static int
173 posix_sock_impl_get_opts(struct spdk_sock_impl_opts *opts, size_t *len)
174 {
175 	return _sock_impl_get_opts(opts, &g_posix_impl_opts, len);
176 }
177 
178 static int
179 ssl_sock_impl_get_opts(struct spdk_sock_impl_opts *opts, size_t *len)
180 {
181 	return _sock_impl_get_opts(opts, &g_ssl_impl_opts, len);
182 }
183 
184 static int
185 _sock_impl_set_opts(const struct spdk_sock_impl_opts *opts, struct spdk_sock_impl_opts *impl_opts,
186 		    size_t len)
187 {
188 	if (!opts) {
189 		errno = EINVAL;
190 		return -1;
191 	}
192 
193 	assert(sizeof(*opts) >= len);
194 	posix_sock_copy_impl_opts(impl_opts, opts, len);
195 
196 	return 0;
197 }
198 
199 static int
200 posix_sock_impl_set_opts(const struct spdk_sock_impl_opts *opts, size_t len)
201 {
202 	return _sock_impl_set_opts(opts, &g_posix_impl_opts, len);
203 }
204 
205 static int
206 ssl_sock_impl_set_opts(const struct spdk_sock_impl_opts *opts, size_t len)
207 {
208 	return _sock_impl_set_opts(opts, &g_ssl_impl_opts, len);
209 }
210 
211 static void
212 _opts_get_impl_opts(const struct spdk_sock_opts *opts, struct spdk_sock_impl_opts *dest,
213 		    const struct spdk_sock_impl_opts *default_impl)
214 {
215 	/* Copy the default impl_opts first to cover cases when user's impl_opts is smaller */
216 	memcpy(dest, default_impl, sizeof(*dest));
217 
218 	if (opts->impl_opts != NULL) {
219 		assert(sizeof(*dest) >= opts->impl_opts_size);
220 		posix_sock_copy_impl_opts(dest, opts->impl_opts, opts->impl_opts_size);
221 	}
222 }
223 
224 static int
225 posix_sock_getaddr(struct spdk_sock *_sock, char *saddr, int slen, uint16_t *sport,
226 		   char *caddr, int clen, uint16_t *cport)
227 {
228 	struct spdk_posix_sock *sock = __posix_sock(_sock);
229 	struct sockaddr_storage sa;
230 	socklen_t salen;
231 	int rc;
232 
233 	assert(sock != NULL);
234 
235 	memset(&sa, 0, sizeof sa);
236 	salen = sizeof sa;
237 	rc = getsockname(sock->fd, (struct sockaddr *) &sa, &salen);
238 	if (rc != 0) {
239 		SPDK_ERRLOG("getsockname() failed (errno=%d)\n", errno);
240 		return -1;
241 	}
242 
243 	switch (sa.ss_family) {
244 	case AF_UNIX:
245 		/* Acceptable connection types that don't have IPs */
246 		return 0;
247 	case AF_INET:
248 	case AF_INET6:
249 		/* Code below will get IP addresses */
250 		break;
251 	default:
252 		/* Unsupported socket family */
253 		return -1;
254 	}
255 
256 	rc = get_addr_str((struct sockaddr *)&sa, saddr, slen);
257 	if (rc != 0) {
258 		SPDK_ERRLOG("getnameinfo() failed (errno=%d)\n", errno);
259 		return -1;
260 	}
261 
262 	if (sport) {
263 		if (sa.ss_family == AF_INET) {
264 			*sport = ntohs(((struct sockaddr_in *) &sa)->sin_port);
265 		} else if (sa.ss_family == AF_INET6) {
266 			*sport = ntohs(((struct sockaddr_in6 *) &sa)->sin6_port);
267 		}
268 	}
269 
270 	memset(&sa, 0, sizeof sa);
271 	salen = sizeof sa;
272 	rc = getpeername(sock->fd, (struct sockaddr *) &sa, &salen);
273 	if (rc != 0) {
274 		SPDK_ERRLOG("getpeername() failed (errno=%d)\n", errno);
275 		return -1;
276 	}
277 
278 	rc = get_addr_str((struct sockaddr *)&sa, caddr, clen);
279 	if (rc != 0) {
280 		SPDK_ERRLOG("getnameinfo() failed (errno=%d)\n", errno);
281 		return -1;
282 	}
283 
284 	if (cport) {
285 		if (sa.ss_family == AF_INET) {
286 			*cport = ntohs(((struct sockaddr_in *) &sa)->sin_port);
287 		} else if (sa.ss_family == AF_INET6) {
288 			*cport = ntohs(((struct sockaddr_in6 *) &sa)->sin6_port);
289 		}
290 	}
291 
292 	return 0;
293 }
294 
295 enum posix_sock_create_type {
296 	SPDK_SOCK_CREATE_LISTEN,
297 	SPDK_SOCK_CREATE_CONNECT,
298 };
299 
300 static int
301 posix_sock_alloc_pipe(struct spdk_posix_sock *sock, int sz)
302 {
303 	uint8_t *new_buf, *old_buf;
304 	struct spdk_pipe *new_pipe;
305 	struct iovec siov[2];
306 	struct iovec diov[2];
307 	int sbytes;
308 	ssize_t bytes;
309 	int rc;
310 
311 	if (sock->recv_buf_sz == sz) {
312 		return 0;
313 	}
314 
315 	/* If the new size is 0, just free the pipe */
316 	if (sz == 0) {
317 		old_buf = spdk_pipe_destroy(sock->recv_pipe);
318 		free(old_buf);
319 		sock->recv_pipe = NULL;
320 		return 0;
321 	} else if (sz < MIN_SOCK_PIPE_SIZE) {
322 		SPDK_ERRLOG("The size of the pipe must be larger than %d\n", MIN_SOCK_PIPE_SIZE);
323 		return -1;
324 	}
325 
326 	/* Round up to next 64 byte multiple */
327 	rc = posix_memalign((void **)&new_buf, 64, sz);
328 	if (rc != 0) {
329 		SPDK_ERRLOG("socket recv buf allocation failed\n");
330 		return -ENOMEM;
331 	}
332 	memset(new_buf, 0, sz);
333 
334 	new_pipe = spdk_pipe_create(new_buf, sz);
335 	if (new_pipe == NULL) {
336 		SPDK_ERRLOG("socket pipe allocation failed\n");
337 		free(new_buf);
338 		return -ENOMEM;
339 	}
340 
341 	if (sock->recv_pipe != NULL) {
342 		/* Pull all of the data out of the old pipe */
343 		sbytes = spdk_pipe_reader_get_buffer(sock->recv_pipe, sock->recv_buf_sz, siov);
344 		if (sbytes > sz) {
345 			/* Too much data to fit into the new pipe size */
346 			old_buf = spdk_pipe_destroy(new_pipe);
347 			free(old_buf);
348 			return -EINVAL;
349 		}
350 
351 		sbytes = spdk_pipe_writer_get_buffer(new_pipe, sz, diov);
352 		assert(sbytes == sz);
353 
354 		bytes = spdk_iovcpy(siov, 2, diov, 2);
355 		spdk_pipe_writer_advance(new_pipe, bytes);
356 
357 		old_buf = spdk_pipe_destroy(sock->recv_pipe);
358 		free(old_buf);
359 	}
360 
361 	sock->recv_buf_sz = sz;
362 	sock->recv_pipe = new_pipe;
363 
364 	if (sock->base.group_impl) {
365 		struct spdk_posix_sock_group_impl *group;
366 
367 		group = __posix_group_impl(sock->base.group_impl);
368 		spdk_pipe_group_add(group->pipe_group, sock->recv_pipe);
369 	}
370 
371 	return 0;
372 }
373 
374 static int
375 posix_sock_set_recvbuf(struct spdk_sock *_sock, int sz)
376 {
377 	struct spdk_posix_sock *sock = __posix_sock(_sock);
378 	int min_size;
379 	int rc;
380 
381 	assert(sock != NULL);
382 
383 	if (_sock->impl_opts.enable_recv_pipe) {
384 		rc = posix_sock_alloc_pipe(sock, sz);
385 		if (rc) {
386 			return rc;
387 		}
388 	}
389 
390 	/* Set kernel buffer size to be at least MIN_SO_RCVBUF_SIZE and
391 	 * _sock->impl_opts.recv_buf_size. */
392 	min_size = spdk_max(MIN_SO_RCVBUF_SIZE, _sock->impl_opts.recv_buf_size);
393 
394 	if (sz < min_size) {
395 		sz = min_size;
396 	}
397 
398 	rc = setsockopt(sock->fd, SOL_SOCKET, SO_RCVBUF, &sz, sizeof(sz));
399 	if (rc < 0) {
400 		return rc;
401 	}
402 
403 	_sock->impl_opts.recv_buf_size = sz;
404 
405 	return 0;
406 }
407 
408 static int
409 posix_sock_set_sendbuf(struct spdk_sock *_sock, int sz)
410 {
411 	struct spdk_posix_sock *sock = __posix_sock(_sock);
412 	int min_size;
413 	int rc;
414 
415 	assert(sock != NULL);
416 
417 	/* Set kernel buffer size to be at least MIN_SO_SNDBUF_SIZE and
418 	 * _sock->impl_opts.send_buf_size. */
419 	min_size = spdk_max(MIN_SO_SNDBUF_SIZE, _sock->impl_opts.send_buf_size);
420 
421 	if (sz < min_size) {
422 		sz = min_size;
423 	}
424 
425 	rc = setsockopt(sock->fd, SOL_SOCKET, SO_SNDBUF, &sz, sizeof(sz));
426 	if (rc < 0) {
427 		return rc;
428 	}
429 
430 	_sock->impl_opts.send_buf_size = sz;
431 
432 	return 0;
433 }
434 
435 static void
436 posix_sock_init(struct spdk_posix_sock *sock, bool enable_zero_copy)
437 {
438 #if defined(SPDK_ZEROCOPY) || defined(__linux__)
439 	int flag;
440 	int rc;
441 #endif
442 
443 #if defined(SPDK_ZEROCOPY)
444 	flag = 1;
445 
446 	if (enable_zero_copy) {
447 		/* Try to turn on zero copy sends */
448 		rc = setsockopt(sock->fd, SOL_SOCKET, SO_ZEROCOPY, &flag, sizeof(flag));
449 		if (rc == 0) {
450 			sock->zcopy = true;
451 		}
452 	}
453 #endif
454 
455 #if defined(__linux__)
456 	flag = 1;
457 
458 	if (sock->base.impl_opts.enable_quickack) {
459 		rc = setsockopt(sock->fd, IPPROTO_TCP, TCP_QUICKACK, &flag, sizeof(flag));
460 		if (rc != 0) {
461 			SPDK_ERRLOG("quickack was failed to set\n");
462 		}
463 	}
464 
465 	spdk_sock_get_placement_id(sock->fd, sock->base.impl_opts.enable_placement_id,
466 				   &sock->placement_id);
467 
468 	if (sock->base.impl_opts.enable_placement_id == PLACEMENT_MARK) {
469 		/* Save placement_id */
470 		spdk_sock_map_insert(&g_map, sock->placement_id, NULL);
471 	}
472 #endif
473 }
474 
475 static struct spdk_posix_sock *
476 posix_sock_alloc(int fd, struct spdk_sock_impl_opts *impl_opts, bool enable_zero_copy)
477 {
478 	struct spdk_posix_sock *sock;
479 
480 	sock = calloc(1, sizeof(*sock));
481 	if (sock == NULL) {
482 		SPDK_ERRLOG("sock allocation failed\n");
483 		return NULL;
484 	}
485 
486 	sock->fd = fd;
487 	memcpy(&sock->base.impl_opts, impl_opts, sizeof(*impl_opts));
488 	posix_sock_init(sock, enable_zero_copy);
489 
490 	return sock;
491 }
492 
493 static int
494 posix_fd_create(struct addrinfo *res, struct spdk_sock_opts *opts,
495 		struct spdk_sock_impl_opts *impl_opts)
496 {
497 	int fd;
498 	int val = 1;
499 	int rc, sz;
500 #if defined(__linux__)
501 	int to;
502 #endif
503 
504 	fd = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
505 	if (fd < 0) {
506 		/* error */
507 		return -1;
508 	}
509 
510 	sz = impl_opts->recv_buf_size;
511 	rc = setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &sz, sizeof(sz));
512 	if (rc) {
513 		/* Not fatal */
514 	}
515 
516 	sz = impl_opts->send_buf_size;
517 	rc = setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &sz, sizeof(sz));
518 	if (rc) {
519 		/* Not fatal */
520 	}
521 
522 	rc = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof val);
523 	if (rc != 0) {
524 		close(fd);
525 		/* error */
526 		return -1;
527 	}
528 	rc = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &val, sizeof val);
529 	if (rc != 0) {
530 		close(fd);
531 		/* error */
532 		return -1;
533 	}
534 
535 #if defined(SO_PRIORITY)
536 	if (opts->priority) {
537 		rc = setsockopt(fd, SOL_SOCKET, SO_PRIORITY, &opts->priority, sizeof val);
538 		if (rc != 0) {
539 			close(fd);
540 			/* error */
541 			return -1;
542 		}
543 	}
544 #endif
545 
546 	if (res->ai_family == AF_INET6) {
547 		rc = setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof val);
548 		if (rc != 0) {
549 			close(fd);
550 			/* error */
551 			return -1;
552 		}
553 	}
554 
555 	if (opts->ack_timeout) {
556 #if defined(__linux__)
557 		to = opts->ack_timeout;
558 		rc = setsockopt(fd, IPPROTO_TCP, TCP_USER_TIMEOUT, &to, sizeof(to));
559 		if (rc != 0) {
560 			close(fd);
561 			/* error */
562 			return -1;
563 		}
564 #else
565 		SPDK_WARNLOG("TCP_USER_TIMEOUT is not supported.\n");
566 #endif
567 	}
568 
569 	return fd;
570 }
571 
572 static int
573 posix_sock_psk_find_session_server_cb(SSL *ssl, const unsigned char *identity,
574 				      size_t identity_len, SSL_SESSION **sess)
575 {
576 	struct spdk_sock_impl_opts *impl_opts = SSL_get_app_data(ssl);
577 	uint8_t key[SSL_MAX_MASTER_KEY_LENGTH] = {};
578 	int keylen;
579 	int rc, i;
580 	STACK_OF(SSL_CIPHER) *ciphers;
581 	const SSL_CIPHER *cipher;
582 	const char *cipher_name;
583 	const char *user_cipher = NULL;
584 	bool found = false;
585 
586 	if (impl_opts->get_key) {
587 		rc = impl_opts->get_key(key, sizeof(key), &user_cipher, identity, impl_opts->get_key_ctx);
588 		if (rc < 0) {
589 			SPDK_ERRLOG("Unable to find PSK for identity: %s\n", identity);
590 			return 0;
591 		}
592 		keylen = rc;
593 	} else {
594 		if (impl_opts->psk_key == NULL) {
595 			SPDK_ERRLOG("PSK is not set\n");
596 			return 0;
597 		}
598 
599 		SPDK_DEBUGLOG(sock_posix, "Length of Client's PSK ID %lu\n", strlen(impl_opts->psk_identity));
600 		if (strcmp(impl_opts->psk_identity, identity) != 0) {
601 			SPDK_ERRLOG("Unknown Client's PSK ID\n");
602 			return 0;
603 		}
604 		keylen = impl_opts->psk_key_size;
605 
606 		memcpy(key, impl_opts->psk_key, keylen);
607 		user_cipher = impl_opts->tls_cipher_suites;
608 	}
609 
610 	if (user_cipher == NULL) {
611 		SPDK_ERRLOG("Cipher suite not set\n");
612 		return 0;
613 	}
614 
615 	*sess = SSL_SESSION_new();
616 	if (*sess == NULL) {
617 		SPDK_ERRLOG("Unable to allocate new SSL session\n");
618 		return 0;
619 	}
620 
621 	ciphers = SSL_get_ciphers(ssl);
622 	for (i = 0; i < sk_SSL_CIPHER_num(ciphers); i++) {
623 		cipher = sk_SSL_CIPHER_value(ciphers, i);
624 		cipher_name = SSL_CIPHER_get_name(cipher);
625 
626 		if (strcmp(user_cipher, cipher_name) == 0) {
627 			rc = SSL_SESSION_set_cipher(*sess, cipher);
628 			if (rc != 1) {
629 				SPDK_ERRLOG("Unable to set cipher: %s\n", cipher_name);
630 				goto err;
631 			}
632 			found = true;
633 			break;
634 		}
635 	}
636 	if (found == false) {
637 		SPDK_ERRLOG("No suitable cipher found\n");
638 		goto err;
639 	}
640 
641 	SPDK_DEBUGLOG(sock_posix, "Cipher selected: %s\n", cipher_name);
642 
643 	rc = SSL_SESSION_set_protocol_version(*sess, TLS1_3_VERSION);
644 	if (rc != 1) {
645 		SPDK_ERRLOG("Unable to set TLS version: %d\n", TLS1_3_VERSION);
646 		goto err;
647 	}
648 
649 	rc = SSL_SESSION_set1_master_key(*sess, key, keylen);
650 	if (rc != 1) {
651 		SPDK_ERRLOG("Unable to set PSK for session\n");
652 		goto err;
653 	}
654 
655 	return 1;
656 
657 err:
658 	SSL_SESSION_free(*sess);
659 	*sess = NULL;
660 	return 0;
661 }
662 
663 static int
664 posix_sock_psk_use_session_client_cb(SSL *ssl, const EVP_MD *md, const unsigned char **identity,
665 				     size_t *identity_len, SSL_SESSION **sess)
666 {
667 	struct spdk_sock_impl_opts *impl_opts = SSL_get_app_data(ssl);
668 	int rc, i;
669 	STACK_OF(SSL_CIPHER) *ciphers;
670 	const SSL_CIPHER *cipher;
671 	const char *cipher_name;
672 	long keylen;
673 	bool found = false;
674 
675 	if (impl_opts->psk_key == NULL) {
676 		SPDK_ERRLOG("PSK is not set\n");
677 		return 0;
678 	}
679 	if (impl_opts->psk_key_size > SSL_MAX_MASTER_KEY_LENGTH) {
680 		SPDK_ERRLOG("PSK too long\n");
681 		return 0;
682 	}
683 	keylen = impl_opts->psk_key_size;
684 
685 	if (impl_opts->tls_cipher_suites == NULL) {
686 		SPDK_ERRLOG("Cipher suite not set\n");
687 		return 0;
688 	}
689 	*sess = SSL_SESSION_new();
690 	if (*sess == NULL) {
691 		SPDK_ERRLOG("Unable to allocate new SSL session\n");
692 		return 0;
693 	}
694 
695 	ciphers = SSL_get_ciphers(ssl);
696 	for (i = 0; i < sk_SSL_CIPHER_num(ciphers); i++) {
697 		cipher = sk_SSL_CIPHER_value(ciphers, i);
698 		cipher_name = SSL_CIPHER_get_name(cipher);
699 
700 		if (strcmp(impl_opts->tls_cipher_suites, cipher_name) == 0) {
701 			rc = SSL_SESSION_set_cipher(*sess, cipher);
702 			if (rc != 1) {
703 				SPDK_ERRLOG("Unable to set cipher: %s\n", cipher_name);
704 				goto err;
705 			}
706 			found = true;
707 			break;
708 		}
709 	}
710 	if (found == false) {
711 		SPDK_ERRLOG("No suitable cipher found\n");
712 		goto err;
713 	}
714 
715 	SPDK_DEBUGLOG(sock_posix, "Cipher selected: %s\n", cipher_name);
716 
717 	rc = SSL_SESSION_set_protocol_version(*sess, TLS1_3_VERSION);
718 	if (rc != 1) {
719 		SPDK_ERRLOG("Unable to set TLS version: %d\n", TLS1_3_VERSION);
720 		goto err;
721 	}
722 
723 	rc = SSL_SESSION_set1_master_key(*sess, impl_opts->psk_key, keylen);
724 	if (rc != 1) {
725 		SPDK_ERRLOG("Unable to set PSK for session\n");
726 		goto err;
727 	}
728 
729 	*identity_len = strlen(impl_opts->psk_identity);
730 	*identity = impl_opts->psk_identity;
731 
732 	return 1;
733 
734 err:
735 	SSL_SESSION_free(*sess);
736 	*sess = NULL;
737 	return 0;
738 }
739 
740 static SSL_CTX *
741 posix_sock_create_ssl_context(const SSL_METHOD *method, struct spdk_sock_opts *opts,
742 			      struct spdk_sock_impl_opts *impl_opts)
743 {
744 	SSL_CTX *ctx;
745 	int tls_version = 0;
746 	bool ktls_enabled = false;
747 #ifdef SSL_OP_ENABLE_KTLS
748 	long options;
749 #endif
750 
751 	SSL_library_init();
752 	OpenSSL_add_all_algorithms();
753 	SSL_load_error_strings();
754 	/* Produce a SSL CTX in SSL V2 and V3 standards compliant way */
755 	ctx = SSL_CTX_new(method);
756 	if (!ctx) {
757 		SPDK_ERRLOG("SSL_CTX_new() failed, msg = %s\n", ERR_error_string(ERR_peek_last_error(), NULL));
758 		return NULL;
759 	}
760 	SPDK_DEBUGLOG(sock_posix, "SSL context created\n");
761 
762 	switch (impl_opts->tls_version) {
763 	case 0:
764 		/* auto-negotioation */
765 		break;
766 	case SPDK_TLS_VERSION_1_3:
767 		tls_version = TLS1_3_VERSION;
768 		break;
769 	default:
770 		SPDK_ERRLOG("Incorrect TLS version provided: %d\n", impl_opts->tls_version);
771 		goto err;
772 	}
773 
774 	if (tls_version) {
775 		SPDK_DEBUGLOG(sock_posix, "Hardening TLS version to '%d'='0x%X'\n", impl_opts->tls_version,
776 			      tls_version);
777 		if (!SSL_CTX_set_min_proto_version(ctx, tls_version)) {
778 			SPDK_ERRLOG("Unable to set Min TLS version to '%d'='0x%X\n", impl_opts->tls_version, tls_version);
779 			goto err;
780 		}
781 		if (!SSL_CTX_set_max_proto_version(ctx, tls_version)) {
782 			SPDK_ERRLOG("Unable to set Max TLS version to '%d'='0x%X\n", impl_opts->tls_version, tls_version);
783 			goto err;
784 		}
785 	}
786 	if (impl_opts->enable_ktls) {
787 		SPDK_DEBUGLOG(sock_posix, "Enabling kTLS offload\n");
788 #ifdef SSL_OP_ENABLE_KTLS
789 		options = SSL_CTX_set_options(ctx, SSL_OP_ENABLE_KTLS);
790 		ktls_enabled = options & SSL_OP_ENABLE_KTLS;
791 #else
792 		ktls_enabled = false;
793 #endif
794 		if (!ktls_enabled) {
795 			SPDK_ERRLOG("Unable to set kTLS offload via SSL_CTX_set_options(). Configure openssl with 'enable-ktls'\n");
796 			goto err;
797 		}
798 	}
799 
800 	/* SSL_CTX_set_ciphersuites() return 1 if the requested
801 	 * cipher suite list was configured, and 0 otherwise. */
802 	if (impl_opts->tls_cipher_suites != NULL &&
803 	    SSL_CTX_set_ciphersuites(ctx, impl_opts->tls_cipher_suites) != 1) {
804 		SPDK_ERRLOG("Unable to set TLS cipher suites for SSL'\n");
805 		goto err;
806 	}
807 
808 	return ctx;
809 
810 err:
811 	SSL_CTX_free(ctx);
812 	return NULL;
813 }
814 
815 static SSL *
816 ssl_sock_setup_connect(SSL_CTX *ctx, int fd)
817 {
818 	SSL *ssl;
819 
820 	ssl = SSL_new(ctx);
821 	if (!ssl) {
822 		SPDK_ERRLOG("SSL_new() failed, msg = %s\n", ERR_error_string(ERR_peek_last_error(), NULL));
823 		return NULL;
824 	}
825 	SSL_set_fd(ssl, fd);
826 	SSL_set_connect_state(ssl);
827 	SSL_set_psk_use_session_callback(ssl, posix_sock_psk_use_session_client_cb);
828 	SPDK_DEBUGLOG(sock_posix, "SSL object creation finished: %p\n", ssl);
829 	SPDK_DEBUGLOG(sock_posix, "%s = SSL_state_string_long(%p)\n", SSL_state_string_long(ssl), ssl);
830 	SPDK_DEBUGLOG(sock_posix, "%s = SSL_state_string_long(%p)\n", SSL_state_string_long(ssl), ssl);
831 	SPDK_DEBUGLOG(sock_posix, "Negotiated Cipher suite:%s\n",
832 		      SSL_CIPHER_get_name(SSL_get_current_cipher(ssl)));
833 	return ssl;
834 }
835 
836 static SSL *
837 ssl_sock_setup_accept(SSL_CTX *ctx, int fd)
838 {
839 	SSL *ssl;
840 
841 	ssl = SSL_new(ctx);
842 	if (!ssl) {
843 		SPDK_ERRLOG("SSL_new() failed, msg = %s\n", ERR_error_string(ERR_peek_last_error(), NULL));
844 		return NULL;
845 	}
846 	SSL_set_fd(ssl, fd);
847 	SSL_set_accept_state(ssl);
848 	SSL_set_psk_find_session_callback(ssl, posix_sock_psk_find_session_server_cb);
849 	SPDK_DEBUGLOG(sock_posix, "SSL object creation finished: %p\n", ssl);
850 	SPDK_DEBUGLOG(sock_posix, "%s = SSL_state_string_long(%p)\n", SSL_state_string_long(ssl), ssl);
851 	SPDK_DEBUGLOG(sock_posix, "%s = SSL_state_string_long(%p)\n", SSL_state_string_long(ssl), ssl);
852 	SPDK_DEBUGLOG(sock_posix, "Negotiated Cipher suite:%s\n",
853 		      SSL_CIPHER_get_name(SSL_get_current_cipher(ssl)));
854 	return ssl;
855 }
856 
857 static ssize_t
858 SSL_readv(SSL *ssl, const struct iovec *iov, int iovcnt)
859 {
860 	int i, rc = 0;
861 	ssize_t total = 0;
862 
863 	for (i = 0; i < iovcnt; i++) {
864 		rc = SSL_read(ssl, iov[i].iov_base, iov[i].iov_len);
865 
866 		if (rc > 0) {
867 			total += rc;
868 		}
869 		if (rc != (int)iov[i].iov_len) {
870 			break;
871 		}
872 	}
873 	if (total > 0) {
874 		errno = 0;
875 		return total;
876 	}
877 	switch (SSL_get_error(ssl, rc)) {
878 	case SSL_ERROR_ZERO_RETURN:
879 		errno = ENOTCONN;
880 		return 0;
881 	case SSL_ERROR_WANT_READ:
882 	case SSL_ERROR_WANT_WRITE:
883 	case SSL_ERROR_WANT_CONNECT:
884 	case SSL_ERROR_WANT_ACCEPT:
885 	case SSL_ERROR_WANT_X509_LOOKUP:
886 	case SSL_ERROR_WANT_ASYNC:
887 	case SSL_ERROR_WANT_ASYNC_JOB:
888 	case SSL_ERROR_WANT_CLIENT_HELLO_CB:
889 		errno = EAGAIN;
890 		return -1;
891 	case SSL_ERROR_SYSCALL:
892 	case SSL_ERROR_SSL:
893 		errno = ENOTCONN;
894 		return -1;
895 	default:
896 		errno = ENOTCONN;
897 		return -1;
898 	}
899 }
900 
901 static ssize_t
902 SSL_writev(SSL *ssl, struct iovec *iov, int iovcnt)
903 {
904 	int i, rc = 0;
905 	ssize_t total = 0;
906 
907 	for (i = 0; i < iovcnt; i++) {
908 		rc = SSL_write(ssl, iov[i].iov_base, iov[i].iov_len);
909 
910 		if (rc > 0) {
911 			total += rc;
912 		}
913 		if (rc != (int)iov[i].iov_len) {
914 			break;
915 		}
916 	}
917 	if (total > 0) {
918 		errno = 0;
919 		return total;
920 	}
921 	switch (SSL_get_error(ssl, rc)) {
922 	case SSL_ERROR_ZERO_RETURN:
923 		errno = ENOTCONN;
924 		return 0;
925 	case SSL_ERROR_WANT_READ:
926 	case SSL_ERROR_WANT_WRITE:
927 	case SSL_ERROR_WANT_CONNECT:
928 	case SSL_ERROR_WANT_ACCEPT:
929 	case SSL_ERROR_WANT_X509_LOOKUP:
930 	case SSL_ERROR_WANT_ASYNC:
931 	case SSL_ERROR_WANT_ASYNC_JOB:
932 	case SSL_ERROR_WANT_CLIENT_HELLO_CB:
933 		errno = EAGAIN;
934 		return -1;
935 	case SSL_ERROR_SYSCALL:
936 	case SSL_ERROR_SSL:
937 		errno = ENOTCONN;
938 		return -1;
939 	default:
940 		errno = ENOTCONN;
941 		return -1;
942 	}
943 }
944 
945 static struct spdk_sock *
946 posix_sock_create(const char *ip, int port,
947 		  enum posix_sock_create_type type,
948 		  struct spdk_sock_opts *opts,
949 		  bool enable_ssl)
950 {
951 	struct spdk_posix_sock *sock;
952 	struct spdk_sock_impl_opts impl_opts;
953 	char buf[MAX_TMPBUF];
954 	char portnum[PORTNUMLEN];
955 	char *p;
956 	struct addrinfo hints, *res, *res0;
957 	int fd, flag;
958 	int rc;
959 	bool enable_zcopy_user_opts = true;
960 	bool enable_zcopy_impl_opts = true;
961 	SSL_CTX *ctx = 0;
962 	SSL *ssl = 0;
963 
964 	assert(opts != NULL);
965 	if (enable_ssl) {
966 		_opts_get_impl_opts(opts, &impl_opts, &g_ssl_impl_opts);
967 	} else {
968 		_opts_get_impl_opts(opts, &impl_opts, &g_posix_impl_opts);
969 	}
970 
971 	if (ip == NULL) {
972 		return NULL;
973 	}
974 	if (ip[0] == '[') {
975 		snprintf(buf, sizeof(buf), "%s", ip + 1);
976 		p = strchr(buf, ']');
977 		if (p != NULL) {
978 			*p = '\0';
979 		}
980 		ip = (const char *) &buf[0];
981 	}
982 
983 	snprintf(portnum, sizeof portnum, "%d", port);
984 	memset(&hints, 0, sizeof hints);
985 	hints.ai_family = PF_UNSPEC;
986 	hints.ai_socktype = SOCK_STREAM;
987 	hints.ai_flags = AI_NUMERICSERV;
988 	hints.ai_flags |= AI_PASSIVE;
989 	hints.ai_flags |= AI_NUMERICHOST;
990 	rc = getaddrinfo(ip, portnum, &hints, &res0);
991 	if (rc != 0) {
992 		SPDK_ERRLOG("getaddrinfo() failed %s (%d)\n", gai_strerror(rc), rc);
993 		return NULL;
994 	}
995 
996 	/* try listen */
997 	fd = -1;
998 	for (res = res0; res != NULL; res = res->ai_next) {
999 retry:
1000 		fd = posix_fd_create(res, opts, &impl_opts);
1001 		if (fd < 0) {
1002 			continue;
1003 		}
1004 		if (type == SPDK_SOCK_CREATE_LISTEN) {
1005 			rc = bind(fd, res->ai_addr, res->ai_addrlen);
1006 			if (rc != 0) {
1007 				SPDK_ERRLOG("bind() failed at port %d, errno = %d\n", port, errno);
1008 				switch (errno) {
1009 				case EINTR:
1010 					/* interrupted? */
1011 					close(fd);
1012 					goto retry;
1013 				case EADDRNOTAVAIL:
1014 					SPDK_ERRLOG("IP address %s not available. "
1015 						    "Verify IP address in config file "
1016 						    "and make sure setup script is "
1017 						    "run before starting spdk app.\n", ip);
1018 				/* FALLTHROUGH */
1019 				default:
1020 					/* try next family */
1021 					close(fd);
1022 					fd = -1;
1023 					continue;
1024 				}
1025 			}
1026 			/* bind OK */
1027 			rc = listen(fd, 512);
1028 			if (rc != 0) {
1029 				SPDK_ERRLOG("listen() failed, errno = %d\n", errno);
1030 				close(fd);
1031 				fd = -1;
1032 				break;
1033 			}
1034 			enable_zcopy_impl_opts = impl_opts.enable_zerocopy_send_server;
1035 		} else if (type == SPDK_SOCK_CREATE_CONNECT) {
1036 			rc = connect(fd, res->ai_addr, res->ai_addrlen);
1037 			if (rc != 0) {
1038 				SPDK_ERRLOG("connect() failed, errno = %d\n", errno);
1039 				/* try next family */
1040 				close(fd);
1041 				fd = -1;
1042 				continue;
1043 			}
1044 			enable_zcopy_impl_opts = impl_opts.enable_zerocopy_send_client;
1045 			if (enable_ssl) {
1046 				ctx = posix_sock_create_ssl_context(TLS_client_method(), opts, &impl_opts);
1047 				if (!ctx) {
1048 					SPDK_ERRLOG("posix_sock_create_ssl_context() failed, errno = %d\n", errno);
1049 					close(fd);
1050 					fd = -1;
1051 					break;
1052 				}
1053 				ssl = ssl_sock_setup_connect(ctx, fd);
1054 				if (!ssl) {
1055 					SPDK_ERRLOG("ssl_sock_setup_connect() failed, errno = %d\n", errno);
1056 					close(fd);
1057 					fd = -1;
1058 					SSL_CTX_free(ctx);
1059 					break;
1060 				}
1061 			}
1062 		}
1063 
1064 		flag = fcntl(fd, F_GETFL);
1065 		if (fcntl(fd, F_SETFL, flag | O_NONBLOCK) < 0) {
1066 			SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%d)\n", fd, errno);
1067 			SSL_free(ssl);
1068 			SSL_CTX_free(ctx);
1069 			close(fd);
1070 			fd = -1;
1071 			break;
1072 		}
1073 		break;
1074 	}
1075 	freeaddrinfo(res0);
1076 
1077 	if (fd < 0) {
1078 		return NULL;
1079 	}
1080 
1081 	/* Only enable zero copy for non-loopback and non-ssl sockets. */
1082 	enable_zcopy_user_opts = opts->zcopy && !sock_is_loopback(fd) && !enable_ssl;
1083 
1084 	sock = posix_sock_alloc(fd, &impl_opts, enable_zcopy_user_opts && enable_zcopy_impl_opts);
1085 	if (sock == NULL) {
1086 		SPDK_ERRLOG("sock allocation failed\n");
1087 		SSL_free(ssl);
1088 		SSL_CTX_free(ctx);
1089 		close(fd);
1090 		return NULL;
1091 	}
1092 
1093 	if (ctx) {
1094 		sock->ctx = ctx;
1095 	}
1096 
1097 	if (ssl) {
1098 		sock->ssl = ssl;
1099 		SSL_set_app_data(ssl, &sock->base.impl_opts);
1100 	}
1101 
1102 	return &sock->base;
1103 }
1104 
1105 static struct spdk_sock *
1106 posix_sock_listen(const char *ip, int port, struct spdk_sock_opts *opts)
1107 {
1108 	return posix_sock_create(ip, port, SPDK_SOCK_CREATE_LISTEN, opts, false);
1109 }
1110 
1111 static struct spdk_sock *
1112 posix_sock_connect(const char *ip, int port, struct spdk_sock_opts *opts)
1113 {
1114 	return posix_sock_create(ip, port, SPDK_SOCK_CREATE_CONNECT, opts, false);
1115 }
1116 
1117 static struct spdk_sock *
1118 _posix_sock_accept(struct spdk_sock *_sock, bool enable_ssl)
1119 {
1120 	struct spdk_posix_sock		*sock = __posix_sock(_sock);
1121 	struct spdk_posix_sock_group_impl *group = __posix_group_impl(sock->base.group_impl);
1122 	struct sockaddr_storage		sa;
1123 	socklen_t			salen;
1124 	int				rc, fd;
1125 	struct spdk_posix_sock		*new_sock;
1126 	int				flag;
1127 	SSL_CTX *ctx = 0;
1128 	SSL *ssl = 0;
1129 
1130 	memset(&sa, 0, sizeof(sa));
1131 	salen = sizeof(sa);
1132 
1133 	assert(sock != NULL);
1134 
1135 	/* epoll_wait will trigger again if there is more than one request */
1136 	if (group && sock->socket_has_data) {
1137 		sock->socket_has_data = false;
1138 		TAILQ_REMOVE(&group->socks_with_data, sock, link);
1139 	}
1140 
1141 	rc = accept(sock->fd, (struct sockaddr *)&sa, &salen);
1142 
1143 	if (rc == -1) {
1144 		return NULL;
1145 	}
1146 
1147 	fd = rc;
1148 
1149 	flag = fcntl(fd, F_GETFL);
1150 	if ((!(flag & O_NONBLOCK)) && (fcntl(fd, F_SETFL, flag | O_NONBLOCK) < 0)) {
1151 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%d)\n", fd, errno);
1152 		close(fd);
1153 		return NULL;
1154 	}
1155 
1156 #if defined(SO_PRIORITY)
1157 	/* The priority is not inherited, so call this function again */
1158 	if (sock->base.opts.priority) {
1159 		rc = setsockopt(fd, SOL_SOCKET, SO_PRIORITY, &sock->base.opts.priority, sizeof(int));
1160 		if (rc != 0) {
1161 			close(fd);
1162 			return NULL;
1163 		}
1164 	}
1165 #endif
1166 
1167 	/* Establish SSL connection */
1168 	if (enable_ssl) {
1169 		ctx = posix_sock_create_ssl_context(TLS_server_method(), &sock->base.opts, &sock->base.impl_opts);
1170 		if (!ctx) {
1171 			SPDK_ERRLOG("posix_sock_create_ssl_context() failed, errno = %d\n", errno);
1172 			close(fd);
1173 			return NULL;
1174 		}
1175 		ssl = ssl_sock_setup_accept(ctx, fd);
1176 		if (!ssl) {
1177 			SPDK_ERRLOG("ssl_sock_setup_accept() failed, errno = %d\n", errno);
1178 			close(fd);
1179 			SSL_CTX_free(ctx);
1180 			return NULL;
1181 		}
1182 	}
1183 
1184 	/* Inherit the zero copy feature from the listen socket */
1185 	new_sock = posix_sock_alloc(fd, &sock->base.impl_opts, sock->zcopy);
1186 	if (new_sock == NULL) {
1187 		close(fd);
1188 		SSL_free(ssl);
1189 		SSL_CTX_free(ctx);
1190 		return NULL;
1191 	}
1192 
1193 	if (ctx) {
1194 		new_sock->ctx = ctx;
1195 	}
1196 
1197 	if (ssl) {
1198 		new_sock->ssl = ssl;
1199 		SSL_set_app_data(ssl, &new_sock->base.impl_opts);
1200 	}
1201 
1202 	return &new_sock->base;
1203 }
1204 
1205 static struct spdk_sock *
1206 posix_sock_accept(struct spdk_sock *_sock)
1207 {
1208 	return _posix_sock_accept(_sock, false);
1209 }
1210 
1211 static int
1212 posix_sock_close(struct spdk_sock *_sock)
1213 {
1214 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1215 	void *pipe_buf;
1216 
1217 	assert(TAILQ_EMPTY(&_sock->pending_reqs));
1218 
1219 	if (sock->ssl != NULL) {
1220 		SSL_shutdown(sock->ssl);
1221 	}
1222 
1223 	/* If the socket fails to close, the best choice is to
1224 	 * leak the fd but continue to free the rest of the sock
1225 	 * memory. */
1226 	close(sock->fd);
1227 
1228 	SSL_free(sock->ssl);
1229 	SSL_CTX_free(sock->ctx);
1230 
1231 	pipe_buf = spdk_pipe_destroy(sock->recv_pipe);
1232 	free(pipe_buf);
1233 	free(sock);
1234 
1235 	return 0;
1236 }
1237 
1238 #ifdef SPDK_ZEROCOPY
1239 static int
1240 _sock_check_zcopy(struct spdk_sock *sock)
1241 {
1242 	struct spdk_posix_sock *psock = __posix_sock(sock);
1243 	struct msghdr msgh = {};
1244 	uint8_t buf[sizeof(struct cmsghdr) + sizeof(struct sock_extended_err)];
1245 	ssize_t rc;
1246 	struct sock_extended_err *serr;
1247 	struct cmsghdr *cm;
1248 	uint32_t idx;
1249 	struct spdk_sock_request *req, *treq;
1250 	bool found;
1251 
1252 	msgh.msg_control = buf;
1253 	msgh.msg_controllen = sizeof(buf);
1254 
1255 	while (true) {
1256 		rc = recvmsg(psock->fd, &msgh, MSG_ERRQUEUE);
1257 
1258 		if (rc < 0) {
1259 			if (errno == EWOULDBLOCK || errno == EAGAIN) {
1260 				return 0;
1261 			}
1262 
1263 			if (!TAILQ_EMPTY(&sock->pending_reqs)) {
1264 				SPDK_ERRLOG("Attempting to receive from ERRQUEUE yielded error, but pending list still has orphaned entries\n");
1265 			} else {
1266 				SPDK_WARNLOG("Recvmsg yielded an error!\n");
1267 			}
1268 			return 0;
1269 		}
1270 
1271 		cm = CMSG_FIRSTHDR(&msgh);
1272 		if (!(cm &&
1273 		      ((cm->cmsg_level == SOL_IP && cm->cmsg_type == IP_RECVERR) ||
1274 		       (cm->cmsg_level == SOL_IPV6 && cm->cmsg_type == IPV6_RECVERR)))) {
1275 			SPDK_WARNLOG("Unexpected cmsg level or type!\n");
1276 			return 0;
1277 		}
1278 
1279 		serr = (struct sock_extended_err *)CMSG_DATA(cm);
1280 		if (serr->ee_errno != 0 || serr->ee_origin != SO_EE_ORIGIN_ZEROCOPY) {
1281 			SPDK_WARNLOG("Unexpected extended error origin\n");
1282 			return 0;
1283 		}
1284 
1285 		/* Most of the time, the pending_reqs array is in the exact
1286 		 * order we need such that all of the requests to complete are
1287 		 * in order, in the front. It is guaranteed that all requests
1288 		 * belonging to the same sendmsg call are sequential, so once
1289 		 * we encounter one match we can stop looping as soon as a
1290 		 * non-match is found.
1291 		 */
1292 		idx = serr->ee_info;
1293 		while (true) {
1294 			found = false;
1295 			TAILQ_FOREACH_SAFE(req, &sock->pending_reqs, internal.link, treq) {
1296 				if (!req->internal.is_zcopy) {
1297 					/* This wasn't a zcopy request. It was just waiting in line to complete */
1298 					rc = spdk_sock_request_put(sock, req, 0);
1299 					if (rc < 0) {
1300 						return rc;
1301 					}
1302 				} else if (req->internal.offset == idx) {
1303 					found = true;
1304 					rc = spdk_sock_request_put(sock, req, 0);
1305 					if (rc < 0) {
1306 						return rc;
1307 					}
1308 				} else if (found) {
1309 					break;
1310 				}
1311 			}
1312 
1313 			if (idx == serr->ee_data) {
1314 				break;
1315 			}
1316 
1317 			if (idx == UINT32_MAX) {
1318 				idx = 0;
1319 			} else {
1320 				idx++;
1321 			}
1322 		}
1323 	}
1324 
1325 	return 0;
1326 }
1327 #endif
1328 
1329 static int
1330 _sock_flush(struct spdk_sock *sock)
1331 {
1332 	struct spdk_posix_sock *psock = __posix_sock(sock);
1333 	struct msghdr msg = {};
1334 	int flags;
1335 	struct iovec iovs[IOV_BATCH_SIZE];
1336 	int iovcnt;
1337 	int retval;
1338 	struct spdk_sock_request *req;
1339 	int i;
1340 	ssize_t rc, sent;
1341 	unsigned int offset;
1342 	size_t len;
1343 	bool is_zcopy = false;
1344 
1345 	/* Can't flush from within a callback or we end up with recursive calls */
1346 	if (sock->cb_cnt > 0) {
1347 		errno = EAGAIN;
1348 		return -1;
1349 	}
1350 
1351 #ifdef SPDK_ZEROCOPY
1352 	if (psock->zcopy) {
1353 		flags = MSG_ZEROCOPY | MSG_NOSIGNAL;
1354 	} else
1355 #endif
1356 	{
1357 		flags = MSG_NOSIGNAL;
1358 	}
1359 
1360 	iovcnt = spdk_sock_prep_reqs(sock, iovs, 0, NULL, &flags);
1361 	if (iovcnt == 0) {
1362 		return 0;
1363 	}
1364 
1365 #ifdef SPDK_ZEROCOPY
1366 	is_zcopy = flags & MSG_ZEROCOPY;
1367 #endif
1368 
1369 	/* Perform the vectored write */
1370 	msg.msg_iov = iovs;
1371 	msg.msg_iovlen = iovcnt;
1372 
1373 	if (psock->ssl) {
1374 		rc = SSL_writev(psock->ssl, iovs, iovcnt);
1375 	} else {
1376 		rc = sendmsg(psock->fd, &msg, flags);
1377 	}
1378 	if (rc <= 0) {
1379 		if (rc == 0 || errno == EAGAIN || errno == EWOULDBLOCK || (errno == ENOBUFS && psock->zcopy)) {
1380 			errno = EAGAIN;
1381 		}
1382 		return -1;
1383 	}
1384 
1385 	sent = rc;
1386 
1387 	if (is_zcopy) {
1388 		/* Handling overflow case, because we use psock->sendmsg_idx - 1 for the
1389 		 * req->internal.offset, so sendmsg_idx should not be zero  */
1390 		if (spdk_unlikely(psock->sendmsg_idx == UINT32_MAX)) {
1391 			psock->sendmsg_idx = 1;
1392 		} else {
1393 			psock->sendmsg_idx++;
1394 		}
1395 	}
1396 
1397 	/* Consume the requests that were actually written */
1398 	req = TAILQ_FIRST(&sock->queued_reqs);
1399 	while (req) {
1400 		offset = req->internal.offset;
1401 
1402 		/* req->internal.is_zcopy is true when the whole req or part of it is sent with zerocopy */
1403 		req->internal.is_zcopy = is_zcopy;
1404 
1405 		for (i = 0; i < req->iovcnt; i++) {
1406 			/* Advance by the offset first */
1407 			if (offset >= SPDK_SOCK_REQUEST_IOV(req, i)->iov_len) {
1408 				offset -= SPDK_SOCK_REQUEST_IOV(req, i)->iov_len;
1409 				continue;
1410 			}
1411 
1412 			/* Calculate the remaining length of this element */
1413 			len = SPDK_SOCK_REQUEST_IOV(req, i)->iov_len - offset;
1414 
1415 			if (len > (size_t)rc) {
1416 				/* This element was partially sent. */
1417 				req->internal.offset += rc;
1418 				return sent;
1419 			}
1420 
1421 			offset = 0;
1422 			req->internal.offset += len;
1423 			rc -= len;
1424 		}
1425 
1426 		/* Handled a full request. */
1427 		spdk_sock_request_pend(sock, req);
1428 
1429 		if (!req->internal.is_zcopy && req == TAILQ_FIRST(&sock->pending_reqs)) {
1430 			/* The sendmsg syscall above isn't currently asynchronous,
1431 			* so it's already done. */
1432 			retval = spdk_sock_request_put(sock, req, 0);
1433 			if (retval) {
1434 				break;
1435 			}
1436 		} else {
1437 			/* Re-use the offset field to hold the sendmsg call index. The
1438 			 * index is 0 based, so subtract one here because we've already
1439 			 * incremented above. */
1440 			req->internal.offset = psock->sendmsg_idx - 1;
1441 		}
1442 
1443 		if (rc == 0) {
1444 			break;
1445 		}
1446 
1447 		req = TAILQ_FIRST(&sock->queued_reqs);
1448 	}
1449 
1450 	return sent;
1451 }
1452 
1453 static int
1454 posix_sock_flush(struct spdk_sock *sock)
1455 {
1456 #ifdef SPDK_ZEROCOPY
1457 	struct spdk_posix_sock *psock = __posix_sock(sock);
1458 
1459 	if (psock->zcopy && !TAILQ_EMPTY(&sock->pending_reqs)) {
1460 		_sock_check_zcopy(sock);
1461 	}
1462 #endif
1463 
1464 	return _sock_flush(sock);
1465 }
1466 
1467 static ssize_t
1468 posix_sock_recv_from_pipe(struct spdk_posix_sock *sock, struct iovec *diov, int diovcnt)
1469 {
1470 	struct iovec siov[2];
1471 	int sbytes;
1472 	ssize_t bytes;
1473 	struct spdk_posix_sock_group_impl *group;
1474 
1475 	sbytes = spdk_pipe_reader_get_buffer(sock->recv_pipe, sock->recv_buf_sz, siov);
1476 	if (sbytes < 0) {
1477 		errno = EINVAL;
1478 		return -1;
1479 	} else if (sbytes == 0) {
1480 		errno = EAGAIN;
1481 		return -1;
1482 	}
1483 
1484 	bytes = spdk_iovcpy(siov, 2, diov, diovcnt);
1485 
1486 	if (bytes == 0) {
1487 		/* The only way this happens is if diov is 0 length */
1488 		errno = EINVAL;
1489 		return -1;
1490 	}
1491 
1492 	spdk_pipe_reader_advance(sock->recv_pipe, bytes);
1493 
1494 	/* If we drained the pipe, mark it appropriately */
1495 	if (spdk_pipe_reader_bytes_available(sock->recv_pipe) == 0) {
1496 		assert(sock->pipe_has_data == true);
1497 
1498 		group = __posix_group_impl(sock->base.group_impl);
1499 		if (group && !sock->socket_has_data) {
1500 			TAILQ_REMOVE(&group->socks_with_data, sock, link);
1501 		}
1502 
1503 		sock->pipe_has_data = false;
1504 	}
1505 
1506 	return bytes;
1507 }
1508 
1509 static inline ssize_t
1510 posix_sock_read(struct spdk_posix_sock *sock)
1511 {
1512 	struct iovec iov[2];
1513 	int bytes_avail, bytes_recvd;
1514 	struct spdk_posix_sock_group_impl *group;
1515 
1516 	bytes_avail = spdk_pipe_writer_get_buffer(sock->recv_pipe, sock->recv_buf_sz, iov);
1517 
1518 	if (bytes_avail <= 0) {
1519 		return bytes_avail;
1520 	}
1521 
1522 	if (sock->ssl) {
1523 		bytes_recvd = SSL_readv(sock->ssl, iov, 2);
1524 	} else {
1525 		bytes_recvd = readv(sock->fd, iov, 2);
1526 	}
1527 
1528 	assert(sock->pipe_has_data == false);
1529 
1530 	if (bytes_recvd <= 0) {
1531 		/* Errors count as draining the socket data */
1532 		if (sock->base.group_impl && sock->socket_has_data) {
1533 			group = __posix_group_impl(sock->base.group_impl);
1534 			TAILQ_REMOVE(&group->socks_with_data, sock, link);
1535 		}
1536 
1537 		sock->socket_has_data = false;
1538 
1539 		return bytes_recvd;
1540 	}
1541 
1542 	spdk_pipe_writer_advance(sock->recv_pipe, bytes_recvd);
1543 
1544 #if DEBUG
1545 	if (sock->base.group_impl) {
1546 		assert(sock->socket_has_data == true);
1547 	}
1548 #endif
1549 
1550 	sock->pipe_has_data = true;
1551 	if (bytes_recvd < bytes_avail) {
1552 		/* We drained the kernel socket entirely. */
1553 		sock->socket_has_data = false;
1554 	}
1555 
1556 	return bytes_recvd;
1557 }
1558 
1559 static ssize_t
1560 posix_sock_readv(struct spdk_sock *_sock, struct iovec *iov, int iovcnt)
1561 {
1562 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1563 	struct spdk_posix_sock_group_impl *group = __posix_group_impl(sock->base.group_impl);
1564 	int rc, i;
1565 	size_t len;
1566 
1567 	if (sock->recv_pipe == NULL) {
1568 		assert(sock->pipe_has_data == false);
1569 		if (group && sock->socket_has_data) {
1570 			sock->socket_has_data = false;
1571 			TAILQ_REMOVE(&group->socks_with_data, sock, link);
1572 		}
1573 		if (sock->ssl) {
1574 			return SSL_readv(sock->ssl, iov, iovcnt);
1575 		} else {
1576 			return readv(sock->fd, iov, iovcnt);
1577 		}
1578 	}
1579 
1580 	/* If the socket is not in a group, we must assume it always has
1581 	 * data waiting for us because it is not epolled */
1582 	if (!sock->pipe_has_data && (group == NULL || sock->socket_has_data)) {
1583 		/* If the user is receiving a sufficiently large amount of data,
1584 		 * receive directly to their buffers. */
1585 		len = 0;
1586 		for (i = 0; i < iovcnt; i++) {
1587 			len += iov[i].iov_len;
1588 		}
1589 
1590 		if (len >= MIN_SOCK_PIPE_SIZE) {
1591 			/* TODO: Should this detect if kernel socket is drained? */
1592 			if (sock->ssl) {
1593 				return SSL_readv(sock->ssl, iov, iovcnt);
1594 			} else {
1595 				return readv(sock->fd, iov, iovcnt);
1596 			}
1597 		}
1598 
1599 		/* Otherwise, do a big read into our pipe */
1600 		rc = posix_sock_read(sock);
1601 		if (rc <= 0) {
1602 			return rc;
1603 		}
1604 	}
1605 
1606 	return posix_sock_recv_from_pipe(sock, iov, iovcnt);
1607 }
1608 
1609 static ssize_t
1610 posix_sock_recv(struct spdk_sock *sock, void *buf, size_t len)
1611 {
1612 	struct iovec iov[1];
1613 
1614 	iov[0].iov_base = buf;
1615 	iov[0].iov_len = len;
1616 
1617 	return posix_sock_readv(sock, iov, 1);
1618 }
1619 
1620 static ssize_t
1621 posix_sock_writev(struct spdk_sock *_sock, struct iovec *iov, int iovcnt)
1622 {
1623 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1624 	int rc;
1625 
1626 	/* In order to process a writev, we need to flush any asynchronous writes
1627 	 * first. */
1628 	rc = _sock_flush(_sock);
1629 	if (rc < 0) {
1630 		return rc;
1631 	}
1632 
1633 	if (!TAILQ_EMPTY(&_sock->queued_reqs)) {
1634 		/* We weren't able to flush all requests */
1635 		errno = EAGAIN;
1636 		return -1;
1637 	}
1638 
1639 	if (sock->ssl) {
1640 		return SSL_writev(sock->ssl, iov, iovcnt);
1641 	} else {
1642 		return writev(sock->fd, iov, iovcnt);
1643 	}
1644 }
1645 
1646 static int
1647 posix_sock_recv_next(struct spdk_sock *_sock, void **buf, void **ctx)
1648 {
1649 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1650 	struct iovec iov;
1651 	ssize_t rc;
1652 
1653 	if (sock->recv_pipe != NULL) {
1654 		errno = ENOTSUP;
1655 		return -1;
1656 	}
1657 
1658 	iov.iov_len = spdk_sock_group_get_buf(_sock->group_impl->group, &iov.iov_base, ctx);
1659 	if (iov.iov_len == 0) {
1660 		errno = ENOBUFS;
1661 		return -1;
1662 	}
1663 
1664 	rc = posix_sock_readv(_sock, &iov, 1);
1665 	if (rc <= 0) {
1666 		spdk_sock_group_provide_buf(_sock->group_impl->group, iov.iov_base, iov.iov_len, *ctx);
1667 		return rc;
1668 	}
1669 
1670 	*buf = iov.iov_base;
1671 
1672 	return rc;
1673 }
1674 
1675 static void
1676 posix_sock_writev_async(struct spdk_sock *sock, struct spdk_sock_request *req)
1677 {
1678 	int rc;
1679 
1680 	spdk_sock_request_queue(sock, req);
1681 
1682 	/* If there are a sufficient number queued, just flush them out immediately. */
1683 	if (sock->queued_iovcnt >= IOV_BATCH_SIZE) {
1684 		rc = _sock_flush(sock);
1685 		if (rc < 0 && errno != EAGAIN) {
1686 			spdk_sock_abort_requests(sock);
1687 		}
1688 	}
1689 }
1690 
1691 static int
1692 posix_sock_set_recvlowat(struct spdk_sock *_sock, int nbytes)
1693 {
1694 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1695 	int val;
1696 	int rc;
1697 
1698 	assert(sock != NULL);
1699 
1700 	val = nbytes;
1701 	rc = setsockopt(sock->fd, SOL_SOCKET, SO_RCVLOWAT, &val, sizeof val);
1702 	if (rc != 0) {
1703 		return -1;
1704 	}
1705 	return 0;
1706 }
1707 
1708 static bool
1709 posix_sock_is_ipv6(struct spdk_sock *_sock)
1710 {
1711 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1712 	struct sockaddr_storage sa;
1713 	socklen_t salen;
1714 	int rc;
1715 
1716 	assert(sock != NULL);
1717 
1718 	memset(&sa, 0, sizeof sa);
1719 	salen = sizeof sa;
1720 	rc = getsockname(sock->fd, (struct sockaddr *) &sa, &salen);
1721 	if (rc != 0) {
1722 		SPDK_ERRLOG("getsockname() failed (errno=%d)\n", errno);
1723 		return false;
1724 	}
1725 
1726 	return (sa.ss_family == AF_INET6);
1727 }
1728 
1729 static bool
1730 posix_sock_is_ipv4(struct spdk_sock *_sock)
1731 {
1732 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1733 	struct sockaddr_storage sa;
1734 	socklen_t salen;
1735 	int rc;
1736 
1737 	assert(sock != NULL);
1738 
1739 	memset(&sa, 0, sizeof sa);
1740 	salen = sizeof sa;
1741 	rc = getsockname(sock->fd, (struct sockaddr *) &sa, &salen);
1742 	if (rc != 0) {
1743 		SPDK_ERRLOG("getsockname() failed (errno=%d)\n", errno);
1744 		return false;
1745 	}
1746 
1747 	return (sa.ss_family == AF_INET);
1748 }
1749 
1750 static bool
1751 posix_sock_is_connected(struct spdk_sock *_sock)
1752 {
1753 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1754 	uint8_t byte;
1755 	int rc;
1756 
1757 	rc = recv(sock->fd, &byte, 1, MSG_PEEK);
1758 	if (rc == 0) {
1759 		return false;
1760 	}
1761 
1762 	if (rc < 0) {
1763 		if (errno == EAGAIN || errno == EWOULDBLOCK) {
1764 			return true;
1765 		}
1766 
1767 		return false;
1768 	}
1769 
1770 	return true;
1771 }
1772 
1773 static struct spdk_sock_group_impl *
1774 posix_sock_group_impl_get_optimal(struct spdk_sock *_sock, struct spdk_sock_group_impl *hint)
1775 {
1776 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1777 	struct spdk_sock_group_impl *group_impl;
1778 
1779 	if (sock->placement_id != -1) {
1780 		spdk_sock_map_lookup(&g_map, sock->placement_id, &group_impl, hint);
1781 		return group_impl;
1782 	}
1783 
1784 	return NULL;
1785 }
1786 
1787 static struct spdk_sock_group_impl *
1788 _sock_group_impl_create(uint32_t enable_placement_id)
1789 {
1790 	struct spdk_posix_sock_group_impl *group_impl;
1791 	int fd;
1792 
1793 #if defined(SPDK_EPOLL)
1794 	fd = epoll_create1(0);
1795 #elif defined(SPDK_KEVENT)
1796 	fd = kqueue();
1797 #endif
1798 	if (fd == -1) {
1799 		return NULL;
1800 	}
1801 
1802 	group_impl = calloc(1, sizeof(*group_impl));
1803 	if (group_impl == NULL) {
1804 		SPDK_ERRLOG("group_impl allocation failed\n");
1805 		close(fd);
1806 		return NULL;
1807 	}
1808 
1809 	group_impl->pipe_group = spdk_pipe_group_create();
1810 	if (group_impl->pipe_group == NULL) {
1811 		SPDK_ERRLOG("pipe_group allocation failed\n");
1812 		free(group_impl);
1813 		close(fd);
1814 		return NULL;
1815 	}
1816 
1817 	group_impl->fd = fd;
1818 	TAILQ_INIT(&group_impl->socks_with_data);
1819 	group_impl->placement_id = -1;
1820 
1821 	if (enable_placement_id == PLACEMENT_CPU) {
1822 		spdk_sock_map_insert(&g_map, spdk_env_get_current_core(), &group_impl->base);
1823 		group_impl->placement_id = spdk_env_get_current_core();
1824 	}
1825 
1826 	return &group_impl->base;
1827 }
1828 
1829 static struct spdk_sock_group_impl *
1830 posix_sock_group_impl_create(void)
1831 {
1832 	return _sock_group_impl_create(g_posix_impl_opts.enable_placement_id);
1833 }
1834 
1835 static struct spdk_sock_group_impl *
1836 ssl_sock_group_impl_create(void)
1837 {
1838 	return _sock_group_impl_create(g_ssl_impl_opts.enable_placement_id);
1839 }
1840 
1841 static void
1842 posix_sock_mark(struct spdk_posix_sock_group_impl *group, struct spdk_posix_sock *sock,
1843 		int placement_id)
1844 {
1845 #if defined(SO_MARK)
1846 	int rc;
1847 
1848 	rc = setsockopt(sock->fd, SOL_SOCKET, SO_MARK,
1849 			&placement_id, sizeof(placement_id));
1850 	if (rc != 0) {
1851 		/* Not fatal */
1852 		SPDK_ERRLOG("Error setting SO_MARK\n");
1853 		return;
1854 	}
1855 
1856 	rc = spdk_sock_map_insert(&g_map, placement_id, &group->base);
1857 	if (rc != 0) {
1858 		/* Not fatal */
1859 		SPDK_ERRLOG("Failed to insert sock group into map: %d\n", rc);
1860 		return;
1861 	}
1862 
1863 	sock->placement_id = placement_id;
1864 #endif
1865 }
1866 
1867 static void
1868 posix_sock_update_mark(struct spdk_sock_group_impl *_group, struct spdk_sock *_sock)
1869 {
1870 	struct spdk_posix_sock_group_impl *group = __posix_group_impl(_group);
1871 
1872 	if (group->placement_id == -1) {
1873 		group->placement_id = spdk_sock_map_find_free(&g_map);
1874 
1875 		/* If a free placement id is found, update existing sockets in this group */
1876 		if (group->placement_id != -1) {
1877 			struct spdk_sock  *sock, *tmp;
1878 
1879 			TAILQ_FOREACH_SAFE(sock, &_group->socks, link, tmp) {
1880 				posix_sock_mark(group, __posix_sock(sock), group->placement_id);
1881 			}
1882 		}
1883 	}
1884 
1885 	if (group->placement_id != -1) {
1886 		/*
1887 		 * group placement id is already determined for this poll group.
1888 		 * Mark socket with group's placement id.
1889 		 */
1890 		posix_sock_mark(group, __posix_sock(_sock), group->placement_id);
1891 	}
1892 }
1893 
1894 static int
1895 posix_sock_group_impl_add_sock(struct spdk_sock_group_impl *_group, struct spdk_sock *_sock)
1896 {
1897 	struct spdk_posix_sock_group_impl *group = __posix_group_impl(_group);
1898 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1899 	int rc;
1900 
1901 #if defined(SPDK_EPOLL)
1902 	struct epoll_event event;
1903 
1904 	memset(&event, 0, sizeof(event));
1905 	/* EPOLLERR is always on even if we don't set it, but be explicit for clarity */
1906 	event.events = EPOLLIN | EPOLLERR;
1907 	if (spdk_interrupt_mode_is_enabled()) {
1908 		event.events |= EPOLLOUT;
1909 	}
1910 
1911 	event.data.ptr = sock;
1912 
1913 	rc = epoll_ctl(group->fd, EPOLL_CTL_ADD, sock->fd, &event);
1914 #elif defined(SPDK_KEVENT)
1915 	struct kevent event;
1916 	struct timespec ts = {0};
1917 
1918 	EV_SET(&event, sock->fd, EVFILT_READ, EV_ADD, 0, 0, sock);
1919 
1920 	rc = kevent(group->fd, &event, 1, NULL, 0, &ts);
1921 #endif
1922 
1923 	if (rc != 0) {
1924 		return rc;
1925 	}
1926 
1927 	/* switched from another polling group due to scheduling */
1928 	if (spdk_unlikely(sock->recv_pipe != NULL  &&
1929 			  (spdk_pipe_reader_bytes_available(sock->recv_pipe) > 0))) {
1930 		sock->pipe_has_data = true;
1931 		sock->socket_has_data = false;
1932 		TAILQ_INSERT_TAIL(&group->socks_with_data, sock, link);
1933 	} else if (sock->recv_pipe != NULL) {
1934 		rc = spdk_pipe_group_add(group->pipe_group, sock->recv_pipe);
1935 		assert(rc == 0);
1936 	}
1937 
1938 	if (_sock->impl_opts.enable_placement_id == PLACEMENT_MARK) {
1939 		posix_sock_update_mark(_group, _sock);
1940 	} else if (sock->placement_id != -1) {
1941 		rc = spdk_sock_map_insert(&g_map, sock->placement_id, &group->base);
1942 		if (rc != 0) {
1943 			SPDK_ERRLOG("Failed to insert sock group into map: %d\n", rc);
1944 			/* Do not treat this as an error. The system will continue running. */
1945 		}
1946 	}
1947 
1948 	return rc;
1949 }
1950 
1951 static int
1952 posix_sock_group_impl_remove_sock(struct spdk_sock_group_impl *_group, struct spdk_sock *_sock)
1953 {
1954 	struct spdk_posix_sock_group_impl *group = __posix_group_impl(_group);
1955 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1956 	int rc;
1957 
1958 	if (sock->pipe_has_data || sock->socket_has_data) {
1959 		TAILQ_REMOVE(&group->socks_with_data, sock, link);
1960 		sock->pipe_has_data = false;
1961 		sock->socket_has_data = false;
1962 	} else if (sock->recv_pipe != NULL) {
1963 		rc = spdk_pipe_group_remove(group->pipe_group, sock->recv_pipe);
1964 		assert(rc == 0);
1965 	}
1966 
1967 	if (sock->placement_id != -1) {
1968 		spdk_sock_map_release(&g_map, sock->placement_id);
1969 	}
1970 
1971 #if defined(SPDK_EPOLL)
1972 	struct epoll_event event;
1973 
1974 	/* Event parameter is ignored but some old kernel version still require it. */
1975 	rc = epoll_ctl(group->fd, EPOLL_CTL_DEL, sock->fd, &event);
1976 #elif defined(SPDK_KEVENT)
1977 	struct kevent event;
1978 	struct timespec ts = {0};
1979 
1980 	EV_SET(&event, sock->fd, EVFILT_READ, EV_DELETE, 0, 0, NULL);
1981 
1982 	rc = kevent(group->fd, &event, 1, NULL, 0, &ts);
1983 	if (rc == 0 && event.flags & EV_ERROR) {
1984 		rc = -1;
1985 		errno = event.data;
1986 	}
1987 #endif
1988 
1989 	spdk_sock_abort_requests(_sock);
1990 
1991 	return rc;
1992 }
1993 
1994 static int
1995 posix_sock_group_impl_poll(struct spdk_sock_group_impl *_group, int max_events,
1996 			   struct spdk_sock **socks)
1997 {
1998 	struct spdk_posix_sock_group_impl *group = __posix_group_impl(_group);
1999 	struct spdk_sock *sock, *tmp;
2000 	int num_events, i, rc;
2001 	struct spdk_posix_sock *psock, *ptmp;
2002 #if defined(SPDK_EPOLL)
2003 	struct epoll_event events[MAX_EVENTS_PER_POLL];
2004 #elif defined(SPDK_KEVENT)
2005 	struct kevent events[MAX_EVENTS_PER_POLL];
2006 	struct timespec ts = {0};
2007 #endif
2008 
2009 #ifdef SPDK_ZEROCOPY
2010 	/* When all of the following conditions are met
2011 	 * - non-blocking socket
2012 	 * - zero copy is enabled
2013 	 * - interrupts suppressed (i.e. busy polling)
2014 	 * - the NIC tx queue is full at the time sendmsg() is called
2015 	 * - epoll_wait determines there is an EPOLLIN event for the socket
2016 	 * then we can get into a situation where data we've sent is queued
2017 	 * up in the kernel network stack, but interrupts have been suppressed
2018 	 * because other traffic is flowing so the kernel misses the signal
2019 	 * to flush the software tx queue. If there wasn't incoming data
2020 	 * pending on the socket, then epoll_wait would have been sufficient
2021 	 * to kick off the send operation, but since there is a pending event
2022 	 * epoll_wait does not trigger the necessary operation.
2023 	 *
2024 	 * We deal with this by checking for all of the above conditions and
2025 	 * additionally looking for EPOLLIN events that were not consumed from
2026 	 * the last poll loop. We take this to mean that the upper layer is
2027 	 * unable to consume them because it is blocked waiting for resources
2028 	 * to free up, and those resources are most likely freed in response
2029 	 * to a pending asynchronous write completing.
2030 	 *
2031 	 * Additionally, sockets that have the same placement_id actually share
2032 	 * an underlying hardware queue. That means polling one of them is
2033 	 * equivalent to polling all of them. As a quick mechanism to avoid
2034 	 * making extra poll() calls, stash the last placement_id during the loop
2035 	 * and only poll if it's not the same. The overwhelmingly common case
2036 	 * is that all sockets in this list have the same placement_id because
2037 	 * SPDK is intentionally grouping sockets by that value, so even
2038 	 * though this won't stop all extra calls to poll(), it's very fast
2039 	 * and will catch all of them in practice.
2040 	 */
2041 	int last_placement_id = -1;
2042 
2043 	TAILQ_FOREACH(psock, &group->socks_with_data, link) {
2044 		if (psock->zcopy && psock->placement_id >= 0 &&
2045 		    psock->placement_id != last_placement_id) {
2046 			struct pollfd pfd = {psock->fd, POLLIN | POLLERR, 0};
2047 
2048 			poll(&pfd, 1, 0);
2049 			last_placement_id = psock->placement_id;
2050 		}
2051 	}
2052 #endif
2053 
2054 	/* This must be a TAILQ_FOREACH_SAFE because while flushing,
2055 	 * a completion callback could remove the sock from the
2056 	 * group. */
2057 	TAILQ_FOREACH_SAFE(sock, &_group->socks, link, tmp) {
2058 		rc = _sock_flush(sock);
2059 		if (rc < 0 && errno != EAGAIN) {
2060 			spdk_sock_abort_requests(sock);
2061 		}
2062 	}
2063 
2064 	assert(max_events > 0);
2065 
2066 #if defined(SPDK_EPOLL)
2067 	num_events = epoll_wait(group->fd, events, max_events, 0);
2068 #elif defined(SPDK_KEVENT)
2069 	num_events = kevent(group->fd, NULL, 0, events, max_events, &ts);
2070 #endif
2071 
2072 	if (num_events == -1) {
2073 		return -1;
2074 	} else if (num_events == 0 && !TAILQ_EMPTY(&_group->socks)) {
2075 		sock = TAILQ_FIRST(&_group->socks);
2076 		psock = __posix_sock(sock);
2077 		/* poll() is called here to busy poll the queue associated with
2078 		 * first socket in list and potentially reap incoming data.
2079 		 */
2080 		if (sock->opts.priority) {
2081 			struct pollfd pfd = {0, 0, 0};
2082 
2083 			pfd.fd = psock->fd;
2084 			pfd.events = POLLIN | POLLERR;
2085 			poll(&pfd, 1, 0);
2086 		}
2087 	}
2088 
2089 	for (i = 0; i < num_events; i++) {
2090 #if defined(SPDK_EPOLL)
2091 		sock = events[i].data.ptr;
2092 		psock = __posix_sock(sock);
2093 
2094 #ifdef SPDK_ZEROCOPY
2095 		if (events[i].events & EPOLLERR) {
2096 			rc = _sock_check_zcopy(sock);
2097 			/* If the socket was closed or removed from
2098 			 * the group in response to a send ack, don't
2099 			 * add it to the array here. */
2100 			if (rc || sock->cb_fn == NULL) {
2101 				continue;
2102 			}
2103 		}
2104 #endif
2105 		if ((events[i].events & EPOLLIN) == 0) {
2106 			continue;
2107 		}
2108 
2109 #elif defined(SPDK_KEVENT)
2110 		sock = events[i].udata;
2111 		psock = __posix_sock(sock);
2112 #endif
2113 
2114 		/* If the socket is not already in the list, add it now */
2115 		if (!psock->socket_has_data && !psock->pipe_has_data) {
2116 			TAILQ_INSERT_TAIL(&group->socks_with_data, psock, link);
2117 		}
2118 		psock->socket_has_data = true;
2119 	}
2120 
2121 	num_events = 0;
2122 
2123 	TAILQ_FOREACH_SAFE(psock, &group->socks_with_data, link, ptmp) {
2124 		if (num_events == max_events) {
2125 			break;
2126 		}
2127 
2128 		/* If the socket's cb_fn is NULL, just remove it from the
2129 		 * list and do not add it to socks array */
2130 		if (spdk_unlikely(psock->base.cb_fn == NULL)) {
2131 			psock->socket_has_data = false;
2132 			psock->pipe_has_data = false;
2133 			TAILQ_REMOVE(&group->socks_with_data, psock, link);
2134 			continue;
2135 		}
2136 
2137 		socks[num_events++] = &psock->base;
2138 	}
2139 
2140 	/* Cycle the has_data list so that each time we poll things aren't
2141 	 * in the same order. Say we have 6 sockets in the list, named as follows:
2142 	 * A B C D E F
2143 	 * And all 6 sockets had epoll events, but max_events is only 3. That means
2144 	 * psock currently points at D. We want to rearrange the list to the following:
2145 	 * D E F A B C
2146 	 *
2147 	 * The variables below are named according to this example to make it easier to
2148 	 * follow the swaps.
2149 	 */
2150 	if (psock != NULL) {
2151 		struct spdk_posix_sock *pa, *pc, *pd, *pf;
2152 
2153 		/* Capture pointers to the elements we need */
2154 		pd = psock;
2155 		pc = TAILQ_PREV(pd, spdk_has_data_list, link);
2156 		pa = TAILQ_FIRST(&group->socks_with_data);
2157 		pf = TAILQ_LAST(&group->socks_with_data, spdk_has_data_list);
2158 
2159 		/* Break the link between C and D */
2160 		pc->link.tqe_next = NULL;
2161 
2162 		/* Connect F to A */
2163 		pf->link.tqe_next = pa;
2164 		pa->link.tqe_prev = &pf->link.tqe_next;
2165 
2166 		/* Fix up the list first/last pointers */
2167 		group->socks_with_data.tqh_first = pd;
2168 		group->socks_with_data.tqh_last = &pc->link.tqe_next;
2169 
2170 		/* D is in front of the list, make tqe prev pointer point to the head of list */
2171 		pd->link.tqe_prev = &group->socks_with_data.tqh_first;
2172 	}
2173 
2174 	return num_events;
2175 }
2176 
2177 static int
2178 posix_sock_group_impl_register_interrupt(struct spdk_sock_group_impl *_group, uint32_t events,
2179 		spdk_interrupt_fn fn, void *arg, const char *name)
2180 {
2181 	struct spdk_posix_sock_group_impl *group = __posix_group_impl(_group);
2182 
2183 	group->intr = spdk_interrupt_register_for_events(group->fd, events, fn, arg, name);
2184 
2185 	return group->intr ? 0 : -1;
2186 }
2187 
2188 static void
2189 posix_sock_group_impl_unregister_interrupt(struct spdk_sock_group_impl *_group)
2190 {
2191 	struct spdk_posix_sock_group_impl *group = __posix_group_impl(_group);
2192 
2193 	spdk_interrupt_unregister(&group->intr);
2194 }
2195 
2196 static int
2197 _sock_group_impl_close(struct spdk_sock_group_impl *_group, uint32_t enable_placement_id)
2198 {
2199 	struct spdk_posix_sock_group_impl *group = __posix_group_impl(_group);
2200 	int rc;
2201 
2202 	if (enable_placement_id == PLACEMENT_CPU) {
2203 		spdk_sock_map_release(&g_map, spdk_env_get_current_core());
2204 	}
2205 
2206 	spdk_pipe_group_destroy(group->pipe_group);
2207 	rc = close(group->fd);
2208 	free(group);
2209 	return rc;
2210 }
2211 
2212 static int
2213 posix_sock_group_impl_close(struct spdk_sock_group_impl *_group)
2214 {
2215 	return _sock_group_impl_close(_group, g_posix_impl_opts.enable_placement_id);
2216 }
2217 
2218 static int
2219 ssl_sock_group_impl_close(struct spdk_sock_group_impl *_group)
2220 {
2221 	return _sock_group_impl_close(_group, g_ssl_impl_opts.enable_placement_id);
2222 }
2223 
2224 static struct spdk_net_impl g_posix_net_impl = {
2225 	.name		= "posix",
2226 	.getaddr	= posix_sock_getaddr,
2227 	.connect	= posix_sock_connect,
2228 	.listen		= posix_sock_listen,
2229 	.accept		= posix_sock_accept,
2230 	.close		= posix_sock_close,
2231 	.recv		= posix_sock_recv,
2232 	.readv		= posix_sock_readv,
2233 	.writev		= posix_sock_writev,
2234 	.recv_next	= posix_sock_recv_next,
2235 	.writev_async	= posix_sock_writev_async,
2236 	.flush		= posix_sock_flush,
2237 	.set_recvlowat	= posix_sock_set_recvlowat,
2238 	.set_recvbuf	= posix_sock_set_recvbuf,
2239 	.set_sendbuf	= posix_sock_set_sendbuf,
2240 	.is_ipv6	= posix_sock_is_ipv6,
2241 	.is_ipv4	= posix_sock_is_ipv4,
2242 	.is_connected	= posix_sock_is_connected,
2243 	.group_impl_get_optimal	= posix_sock_group_impl_get_optimal,
2244 	.group_impl_create	= posix_sock_group_impl_create,
2245 	.group_impl_add_sock	= posix_sock_group_impl_add_sock,
2246 	.group_impl_remove_sock = posix_sock_group_impl_remove_sock,
2247 	.group_impl_poll	= posix_sock_group_impl_poll,
2248 	.group_impl_register_interrupt     = posix_sock_group_impl_register_interrupt,
2249 	.group_impl_unregister_interrupt  = posix_sock_group_impl_unregister_interrupt,
2250 	.group_impl_close	= posix_sock_group_impl_close,
2251 	.get_opts	= posix_sock_impl_get_opts,
2252 	.set_opts	= posix_sock_impl_set_opts,
2253 };
2254 
2255 SPDK_NET_IMPL_REGISTER_DEFAULT(posix, &g_posix_net_impl);
2256 
2257 static struct spdk_sock *
2258 ssl_sock_listen(const char *ip, int port, struct spdk_sock_opts *opts)
2259 {
2260 	return posix_sock_create(ip, port, SPDK_SOCK_CREATE_LISTEN, opts, true);
2261 }
2262 
2263 static struct spdk_sock *
2264 ssl_sock_connect(const char *ip, int port, struct spdk_sock_opts *opts)
2265 {
2266 	return posix_sock_create(ip, port, SPDK_SOCK_CREATE_CONNECT, opts, true);
2267 }
2268 
2269 static struct spdk_sock *
2270 ssl_sock_accept(struct spdk_sock *_sock)
2271 {
2272 	return _posix_sock_accept(_sock, true);
2273 }
2274 
2275 static struct spdk_net_impl g_ssl_net_impl = {
2276 	.name		= "ssl",
2277 	.getaddr	= posix_sock_getaddr,
2278 	.connect	= ssl_sock_connect,
2279 	.listen		= ssl_sock_listen,
2280 	.accept		= ssl_sock_accept,
2281 	.close		= posix_sock_close,
2282 	.recv		= posix_sock_recv,
2283 	.readv		= posix_sock_readv,
2284 	.writev		= posix_sock_writev,
2285 	.recv_next	= posix_sock_recv_next,
2286 	.writev_async	= posix_sock_writev_async,
2287 	.flush		= posix_sock_flush,
2288 	.set_recvlowat	= posix_sock_set_recvlowat,
2289 	.set_recvbuf	= posix_sock_set_recvbuf,
2290 	.set_sendbuf	= posix_sock_set_sendbuf,
2291 	.is_ipv6	= posix_sock_is_ipv6,
2292 	.is_ipv4	= posix_sock_is_ipv4,
2293 	.is_connected	= posix_sock_is_connected,
2294 	.group_impl_get_optimal	= posix_sock_group_impl_get_optimal,
2295 	.group_impl_create	= ssl_sock_group_impl_create,
2296 	.group_impl_add_sock	= posix_sock_group_impl_add_sock,
2297 	.group_impl_remove_sock = posix_sock_group_impl_remove_sock,
2298 	.group_impl_poll	= posix_sock_group_impl_poll,
2299 	.group_impl_register_interrupt    = posix_sock_group_impl_register_interrupt,
2300 	.group_impl_unregister_interrupt  = posix_sock_group_impl_unregister_interrupt,
2301 	.group_impl_close	= ssl_sock_group_impl_close,
2302 	.get_opts	= ssl_sock_impl_get_opts,
2303 	.set_opts	= ssl_sock_impl_set_opts,
2304 };
2305 
2306 SPDK_NET_IMPL_REGISTER(ssl, &g_ssl_net_impl);
2307 SPDK_LOG_REGISTER_COMPONENT(sock_posix)
2308