xref: /spdk/module/sock/posix/posix.c (revision f869197b76ff6981e901b6d9a05789e1b993494a)
1 /*   SPDX-License-Identifier: BSD-3-Clause
2  *   Copyright (c) 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 	void			*recv_buf;
49 	int			recv_buf_sz;
50 	bool			pipe_has_data;
51 	bool			socket_has_data;
52 	bool			zcopy;
53 
54 	int			placement_id;
55 
56 	SSL_CTX			*ctx;
57 	SSL			*ssl;
58 
59 	TAILQ_ENTRY(spdk_posix_sock)	link;
60 };
61 
62 TAILQ_HEAD(spdk_has_data_list, spdk_posix_sock);
63 
64 struct spdk_posix_sock_group_impl {
65 	struct spdk_sock_group_impl	base;
66 	int				fd;
67 	struct spdk_has_data_list	socks_with_data;
68 	int				placement_id;
69 };
70 
71 static struct spdk_sock_impl_opts g_spdk_posix_sock_impl_opts = {
72 	.recv_buf_size = MIN_SO_RCVBUF_SIZE,
73 	.send_buf_size = MIN_SO_SNDBUF_SIZE,
74 	.enable_recv_pipe = true,
75 	.enable_quickack = false,
76 	.enable_placement_id = PLACEMENT_NONE,
77 	.enable_zerocopy_send_server = true,
78 	.enable_zerocopy_send_client = false,
79 	.zerocopy_threshold = 0,
80 	.tls_version = 0,
81 	.enable_ktls = false,
82 	.psk_key = NULL,
83 	.psk_identity = NULL
84 };
85 
86 static struct spdk_sock_map g_map = {
87 	.entries = STAILQ_HEAD_INITIALIZER(g_map.entries),
88 	.mtx = PTHREAD_MUTEX_INITIALIZER
89 };
90 
91 __attribute((destructor)) static void
92 posix_sock_map_cleanup(void)
93 {
94 	spdk_sock_map_cleanup(&g_map);
95 }
96 
97 #define __posix_sock(sock) (struct spdk_posix_sock *)sock
98 #define __posix_group_impl(group) (struct spdk_posix_sock_group_impl *)group
99 
100 static void
101 posix_sock_copy_impl_opts(struct spdk_sock_impl_opts *dest, const struct spdk_sock_impl_opts *src,
102 			  size_t len)
103 {
104 #define FIELD_OK(field) \
105 	offsetof(struct spdk_sock_impl_opts, field) + sizeof(src->field) <= len
106 
107 #define SET_FIELD(field) \
108 	if (FIELD_OK(field)) { \
109 		dest->field = src->field; \
110 	}
111 
112 	SET_FIELD(recv_buf_size);
113 	SET_FIELD(send_buf_size);
114 	SET_FIELD(enable_recv_pipe);
115 	SET_FIELD(enable_zerocopy_send);
116 	SET_FIELD(enable_quickack);
117 	SET_FIELD(enable_placement_id);
118 	SET_FIELD(enable_zerocopy_send_server);
119 	SET_FIELD(enable_zerocopy_send_client);
120 	SET_FIELD(zerocopy_threshold);
121 	SET_FIELD(tls_version);
122 	SET_FIELD(enable_ktls);
123 	SET_FIELD(psk_key);
124 	SET_FIELD(psk_identity);
125 
126 #undef SET_FIELD
127 #undef FIELD_OK
128 }
129 
130 static int
131 posix_sock_impl_get_opts(struct spdk_sock_impl_opts *opts, size_t *len)
132 {
133 	if (!opts || !len) {
134 		errno = EINVAL;
135 		return -1;
136 	}
137 
138 	assert(sizeof(*opts) >= *len);
139 	memset(opts, 0, *len);
140 
141 	posix_sock_copy_impl_opts(opts, &g_spdk_posix_sock_impl_opts, *len);
142 	*len = spdk_min(*len, sizeof(g_spdk_posix_sock_impl_opts));
143 
144 	return 0;
145 }
146 
147 static int
148 posix_sock_impl_set_opts(const struct spdk_sock_impl_opts *opts, size_t len)
149 {
150 	if (!opts) {
151 		errno = EINVAL;
152 		return -1;
153 	}
154 
155 	assert(sizeof(*opts) >= len);
156 	posix_sock_copy_impl_opts(&g_spdk_posix_sock_impl_opts, opts, len);
157 
158 	return 0;
159 }
160 
161 static void
162 posix_opts_get_impl_opts(const struct spdk_sock_opts *opts, struct spdk_sock_impl_opts *dest)
163 {
164 	/* Copy the default impl_opts first to cover cases when user's impl_opts is smaller */
165 	memcpy(dest, &g_spdk_posix_sock_impl_opts, sizeof(*dest));
166 
167 	if (opts->impl_opts != NULL) {
168 		assert(sizeof(*dest) >= opts->impl_opts_size);
169 		posix_sock_copy_impl_opts(dest, opts->impl_opts, opts->impl_opts_size);
170 	}
171 }
172 
173 static int
174 posix_sock_getaddr(struct spdk_sock *_sock, char *saddr, int slen, uint16_t *sport,
175 		   char *caddr, int clen, uint16_t *cport)
176 {
177 	struct spdk_posix_sock *sock = __posix_sock(_sock);
178 	struct sockaddr_storage sa;
179 	socklen_t salen;
180 	int rc;
181 
182 	assert(sock != NULL);
183 
184 	memset(&sa, 0, sizeof sa);
185 	salen = sizeof sa;
186 	rc = getsockname(sock->fd, (struct sockaddr *) &sa, &salen);
187 	if (rc != 0) {
188 		SPDK_ERRLOG("getsockname() failed (errno=%d)\n", errno);
189 		return -1;
190 	}
191 
192 	switch (sa.ss_family) {
193 	case AF_UNIX:
194 		/* Acceptable connection types that don't have IPs */
195 		return 0;
196 	case AF_INET:
197 	case AF_INET6:
198 		/* Code below will get IP addresses */
199 		break;
200 	default:
201 		/* Unsupported socket family */
202 		return -1;
203 	}
204 
205 	rc = get_addr_str((struct sockaddr *)&sa, saddr, slen);
206 	if (rc != 0) {
207 		SPDK_ERRLOG("getnameinfo() failed (errno=%d)\n", errno);
208 		return -1;
209 	}
210 
211 	if (sport) {
212 		if (sa.ss_family == AF_INET) {
213 			*sport = ntohs(((struct sockaddr_in *) &sa)->sin_port);
214 		} else if (sa.ss_family == AF_INET6) {
215 			*sport = ntohs(((struct sockaddr_in6 *) &sa)->sin6_port);
216 		}
217 	}
218 
219 	memset(&sa, 0, sizeof sa);
220 	salen = sizeof sa;
221 	rc = getpeername(sock->fd, (struct sockaddr *) &sa, &salen);
222 	if (rc != 0) {
223 		SPDK_ERRLOG("getpeername() failed (errno=%d)\n", errno);
224 		return -1;
225 	}
226 
227 	rc = get_addr_str((struct sockaddr *)&sa, caddr, clen);
228 	if (rc != 0) {
229 		SPDK_ERRLOG("getnameinfo() failed (errno=%d)\n", errno);
230 		return -1;
231 	}
232 
233 	if (cport) {
234 		if (sa.ss_family == AF_INET) {
235 			*cport = ntohs(((struct sockaddr_in *) &sa)->sin_port);
236 		} else if (sa.ss_family == AF_INET6) {
237 			*cport = ntohs(((struct sockaddr_in6 *) &sa)->sin6_port);
238 		}
239 	}
240 
241 	return 0;
242 }
243 
244 enum posix_sock_create_type {
245 	SPDK_SOCK_CREATE_LISTEN,
246 	SPDK_SOCK_CREATE_CONNECT,
247 };
248 
249 static int
250 posix_sock_alloc_pipe(struct spdk_posix_sock *sock, int sz)
251 {
252 	uint8_t *new_buf;
253 	struct spdk_pipe *new_pipe;
254 	struct iovec siov[2];
255 	struct iovec diov[2];
256 	int sbytes;
257 	ssize_t bytes;
258 
259 	if (sock->recv_buf_sz == sz) {
260 		return 0;
261 	}
262 
263 	/* If the new size is 0, just free the pipe */
264 	if (sz == 0) {
265 		spdk_pipe_destroy(sock->recv_pipe);
266 		free(sock->recv_buf);
267 		sock->recv_pipe = NULL;
268 		sock->recv_buf = NULL;
269 		return 0;
270 	} else if (sz < MIN_SOCK_PIPE_SIZE) {
271 		SPDK_ERRLOG("The size of the pipe must be larger than %d\n", MIN_SOCK_PIPE_SIZE);
272 		return -1;
273 	}
274 
275 	/* Round up to next 64 byte multiple */
276 	new_buf = calloc(SPDK_ALIGN_CEIL(sz + 1, 64), sizeof(uint8_t));
277 	if (!new_buf) {
278 		SPDK_ERRLOG("socket recv buf allocation failed\n");
279 		return -ENOMEM;
280 	}
281 
282 	new_pipe = spdk_pipe_create(new_buf, sz + 1);
283 	if (new_pipe == NULL) {
284 		SPDK_ERRLOG("socket pipe allocation failed\n");
285 		free(new_buf);
286 		return -ENOMEM;
287 	}
288 
289 	if (sock->recv_pipe != NULL) {
290 		/* Pull all of the data out of the old pipe */
291 		sbytes = spdk_pipe_reader_get_buffer(sock->recv_pipe, sock->recv_buf_sz, siov);
292 		if (sbytes > sz) {
293 			/* Too much data to fit into the new pipe size */
294 			spdk_pipe_destroy(new_pipe);
295 			free(new_buf);
296 			return -EINVAL;
297 		}
298 
299 		sbytes = spdk_pipe_writer_get_buffer(new_pipe, sz, diov);
300 		assert(sbytes == sz);
301 
302 		bytes = spdk_iovcpy(siov, 2, diov, 2);
303 		spdk_pipe_writer_advance(new_pipe, bytes);
304 
305 		spdk_pipe_destroy(sock->recv_pipe);
306 		free(sock->recv_buf);
307 	}
308 
309 	sock->recv_buf_sz = sz;
310 	sock->recv_buf = new_buf;
311 	sock->recv_pipe = new_pipe;
312 
313 	return 0;
314 }
315 
316 static int
317 posix_sock_set_recvbuf(struct spdk_sock *_sock, int sz)
318 {
319 	struct spdk_posix_sock *sock = __posix_sock(_sock);
320 	int rc;
321 
322 	assert(sock != NULL);
323 
324 	if (_sock->impl_opts.enable_recv_pipe) {
325 		rc = posix_sock_alloc_pipe(sock, sz);
326 		if (rc) {
327 			return rc;
328 		}
329 	}
330 
331 	/* Set kernel buffer size to be at least MIN_SO_RCVBUF_SIZE */
332 	if (sz < MIN_SO_RCVBUF_SIZE) {
333 		sz = MIN_SO_RCVBUF_SIZE;
334 	}
335 
336 	rc = setsockopt(sock->fd, SOL_SOCKET, SO_RCVBUF, &sz, sizeof(sz));
337 	if (rc < 0) {
338 		return rc;
339 	}
340 
341 	_sock->impl_opts.recv_buf_size = sz;
342 
343 	return 0;
344 }
345 
346 static int
347 posix_sock_set_sendbuf(struct spdk_sock *_sock, int sz)
348 {
349 	struct spdk_posix_sock *sock = __posix_sock(_sock);
350 	int rc;
351 
352 	assert(sock != NULL);
353 
354 	if (sz < MIN_SO_SNDBUF_SIZE) {
355 		sz = MIN_SO_SNDBUF_SIZE;
356 	}
357 
358 	rc = setsockopt(sock->fd, SOL_SOCKET, SO_SNDBUF, &sz, sizeof(sz));
359 	if (rc < 0) {
360 		return rc;
361 	}
362 
363 	_sock->impl_opts.send_buf_size = sz;
364 
365 	return 0;
366 }
367 
368 static void
369 posix_sock_init(struct spdk_posix_sock *sock, bool enable_zero_copy)
370 {
371 #if defined(SPDK_ZEROCOPY) || defined(__linux__)
372 	int flag;
373 	int rc;
374 #endif
375 
376 #if defined(SPDK_ZEROCOPY)
377 	flag = 1;
378 
379 	if (enable_zero_copy) {
380 		/* Try to turn on zero copy sends */
381 		rc = setsockopt(sock->fd, SOL_SOCKET, SO_ZEROCOPY, &flag, sizeof(flag));
382 		if (rc == 0) {
383 			sock->zcopy = true;
384 		}
385 	}
386 #endif
387 
388 #if defined(__linux__)
389 	flag = 1;
390 
391 	if (sock->base.impl_opts.enable_quickack) {
392 		rc = setsockopt(sock->fd, IPPROTO_TCP, TCP_QUICKACK, &flag, sizeof(flag));
393 		if (rc != 0) {
394 			SPDK_ERRLOG("quickack was failed to set\n");
395 		}
396 	}
397 
398 	spdk_sock_get_placement_id(sock->fd, sock->base.impl_opts.enable_placement_id,
399 				   &sock->placement_id);
400 
401 	if (sock->base.impl_opts.enable_placement_id == PLACEMENT_MARK) {
402 		/* Save placement_id */
403 		spdk_sock_map_insert(&g_map, sock->placement_id, NULL);
404 	}
405 #endif
406 }
407 
408 static struct spdk_posix_sock *
409 posix_sock_alloc(int fd, struct spdk_sock_impl_opts *impl_opts, bool enable_zero_copy)
410 {
411 	struct spdk_posix_sock *sock;
412 
413 	sock = calloc(1, sizeof(*sock));
414 	if (sock == NULL) {
415 		SPDK_ERRLOG("sock allocation failed\n");
416 		return NULL;
417 	}
418 
419 	sock->fd = fd;
420 	memcpy(&sock->base.impl_opts, impl_opts, sizeof(*impl_opts));
421 	posix_sock_init(sock, enable_zero_copy);
422 
423 	return sock;
424 }
425 
426 static int
427 posix_fd_create(struct addrinfo *res, struct spdk_sock_opts *opts,
428 		struct spdk_sock_impl_opts *impl_opts)
429 {
430 	int fd;
431 	int val = 1;
432 	int rc, sz;
433 #if defined(__linux__)
434 	int to;
435 #endif
436 
437 	fd = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
438 	if (fd < 0) {
439 		/* error */
440 		return -1;
441 	}
442 
443 	sz = impl_opts->recv_buf_size;
444 	rc = setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &sz, sizeof(sz));
445 	if (rc) {
446 		/* Not fatal */
447 	}
448 
449 	sz = impl_opts->send_buf_size;
450 	rc = setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &sz, sizeof(sz));
451 	if (rc) {
452 		/* Not fatal */
453 	}
454 
455 	rc = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof val);
456 	if (rc != 0) {
457 		close(fd);
458 		/* error */
459 		return -1;
460 	}
461 	rc = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &val, sizeof val);
462 	if (rc != 0) {
463 		close(fd);
464 		/* error */
465 		return -1;
466 	}
467 
468 #if defined(SO_PRIORITY)
469 	if (opts->priority) {
470 		rc = setsockopt(fd, SOL_SOCKET, SO_PRIORITY, &opts->priority, sizeof val);
471 		if (rc != 0) {
472 			close(fd);
473 			/* error */
474 			return -1;
475 		}
476 	}
477 #endif
478 
479 	if (res->ai_family == AF_INET6) {
480 		rc = setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof val);
481 		if (rc != 0) {
482 			close(fd);
483 			/* error */
484 			return -1;
485 		}
486 	}
487 
488 	if (opts->ack_timeout) {
489 #if defined(__linux__)
490 		to = opts->ack_timeout;
491 		rc = setsockopt(fd, IPPROTO_TCP, TCP_USER_TIMEOUT, &to, sizeof(to));
492 		if (rc != 0) {
493 			close(fd);
494 			/* error */
495 			return -1;
496 		}
497 #else
498 		SPDK_WARNLOG("TCP_USER_TIMEOUT is not supported.\n");
499 #endif
500 	}
501 
502 	return fd;
503 }
504 
505 static unsigned int
506 posix_sock_tls_psk_server_cb(SSL *ssl,
507 			     const char *id,
508 			     unsigned char *psk,
509 			     unsigned int max_psk_len)
510 {
511 	long key_len;
512 	unsigned char *default_psk;
513 	struct spdk_sock_impl_opts *impl_opts;
514 
515 	impl_opts = SSL_get_app_data(ssl);
516 
517 	if (impl_opts->psk_key == NULL) {
518 		SPDK_ERRLOG("PSK is not set\n");
519 		goto err;
520 	}
521 	SPDK_DEBUGLOG(sock_posix, "Length of Client's PSK ID %lu\n", strlen(impl_opts->psk_identity));
522 	if (id == NULL) {
523 		SPDK_ERRLOG("Received empty PSK ID\n");
524 		goto err;
525 	}
526 	SPDK_DEBUGLOG(sock_posix,  "Received PSK ID '%s'\n", id);
527 	if (strcmp(impl_opts->psk_identity, id) != 0) {
528 		SPDK_ERRLOG("Unknown Client's PSK ID\n");
529 		goto err;
530 	}
531 
532 	SPDK_DEBUGLOG(sock_posix, "Length of Client's PSK KEY %u\n", max_psk_len);
533 	default_psk = OPENSSL_hexstr2buf(impl_opts->psk_key, &key_len);
534 	if (default_psk == NULL) {
535 		SPDK_ERRLOG("Could not unhexlify PSK\n");
536 		goto err;
537 	}
538 	if (key_len > max_psk_len) {
539 		SPDK_ERRLOG("Insufficient buffer size to copy PSK\n");
540 		goto err;
541 	}
542 
543 	memcpy(psk, default_psk, key_len);
544 
545 	return key_len;
546 
547 err:
548 	return 0;
549 }
550 
551 static unsigned int
552 posix_sock_tls_psk_client_cb(SSL *ssl, const char *hint,
553 			     char *identity,
554 			     unsigned int max_identity_len,
555 			     unsigned char *psk,
556 			     unsigned int max_psk_len)
557 {
558 	long key_len;
559 	unsigned char *default_psk;
560 	struct spdk_sock_impl_opts *impl_opts;
561 
562 	impl_opts = SSL_get_app_data(ssl);
563 
564 	if (hint) {
565 		SPDK_DEBUGLOG(sock_posix,  "Received PSK identity hint '%s'\n", hint);
566 	}
567 
568 	if (impl_opts->psk_key == NULL) {
569 		SPDK_ERRLOG("PSK is not set\n");
570 		goto err;
571 	}
572 	default_psk = OPENSSL_hexstr2buf(impl_opts->psk_key, &key_len);
573 	if (default_psk == NULL) {
574 		SPDK_ERRLOG("Could not unhexlify PSK\n");
575 		goto err;
576 	}
577 	if ((strlen(impl_opts->psk_identity) + 1 > max_identity_len)
578 	    || (key_len > max_psk_len)) {
579 		SPDK_ERRLOG("PSK ID or Key buffer is not sufficient\n");
580 		goto err;
581 	}
582 	spdk_strcpy_pad(identity, impl_opts->psk_identity, strlen(impl_opts->psk_identity), 0);
583 	SPDK_DEBUGLOG(sock_posix, "Sending PSK identity '%s'\n", identity);
584 
585 	memcpy(psk, default_psk, key_len);
586 	SPDK_DEBUGLOG(sock_posix, "Provided out-of-band (OOB) PSK for TLS1.3 client\n");
587 
588 	return key_len;
589 
590 err:
591 	return 0;
592 }
593 
594 static SSL_CTX *
595 posix_sock_create_ssl_context(const SSL_METHOD *method, struct spdk_sock_opts *opts,
596 			      struct spdk_sock_impl_opts *impl_opts)
597 {
598 	SSL_CTX *ctx;
599 	int tls_version = 0;
600 	bool ktls_enabled = false;
601 #ifdef SSL_OP_ENABLE_KTLS
602 	long options;
603 #endif
604 
605 	SSL_library_init();
606 	OpenSSL_add_all_algorithms();
607 	SSL_load_error_strings();
608 	/* Produce a SSL CTX in SSL V2 and V3 standards compliant way */
609 	ctx = SSL_CTX_new(method);
610 	if (!ctx) {
611 		SPDK_ERRLOG("SSL_CTX_new() failed, msg = %s\n", ERR_error_string(ERR_peek_last_error(), NULL));
612 		return NULL;
613 	}
614 	SPDK_DEBUGLOG(sock_posix, "SSL context created\n");
615 
616 	switch (impl_opts->tls_version) {
617 	case 0:
618 		/* auto-negotioation */
619 		break;
620 	case SPDK_TLS_VERSION_1_1:
621 		tls_version = TLS1_1_VERSION;
622 		break;
623 	case SPDK_TLS_VERSION_1_2:
624 		tls_version = TLS1_2_VERSION;
625 		break;
626 	case SPDK_TLS_VERSION_1_3:
627 		tls_version = TLS1_3_VERSION;
628 		break;
629 	default:
630 		SPDK_ERRLOG("Incorrect TLS version provided: %d\n", impl_opts->tls_version);
631 		goto err;
632 	}
633 
634 	if (tls_version) {
635 		SPDK_DEBUGLOG(sock_posix, "Hardening TLS version to '%d'='0x%X'\n", impl_opts->tls_version,
636 			      tls_version);
637 		if (!SSL_CTX_set_min_proto_version(ctx, tls_version)) {
638 			SPDK_ERRLOG("Unable to set Min TLS version to '%d'='0x%X\n", impl_opts->tls_version, tls_version);
639 			goto err;
640 		}
641 		if (!SSL_CTX_set_max_proto_version(ctx, tls_version)) {
642 			SPDK_ERRLOG("Unable to set Max TLS version to '%d'='0x%X\n", impl_opts->tls_version, tls_version);
643 			goto err;
644 		}
645 	}
646 	if (impl_opts->enable_ktls) {
647 		SPDK_DEBUGLOG(sock_posix, "Enabling kTLS offload\n");
648 #ifdef SSL_OP_ENABLE_KTLS
649 		options = SSL_CTX_set_options(ctx, SSL_OP_ENABLE_KTLS);
650 		ktls_enabled = options & SSL_OP_ENABLE_KTLS;
651 #else
652 		ktls_enabled = false;
653 #endif
654 		if (!ktls_enabled) {
655 			SPDK_ERRLOG("Unable to set kTLS offload via SSL_CTX_set_options(). Configure openssl with 'enable-ktls'\n");
656 			goto err;
657 		}
658 	}
659 
660 	return ctx;
661 
662 err:
663 	SSL_CTX_free(ctx);
664 	return NULL;
665 }
666 
667 static SSL *
668 ssl_sock_connect_loop(SSL_CTX *ctx, int fd, struct spdk_sock_impl_opts *impl_opts)
669 {
670 	int rc;
671 	SSL *ssl;
672 	int ssl_get_error;
673 
674 	ssl = SSL_new(ctx);
675 	if (!ssl) {
676 		SPDK_ERRLOG("SSL_new() failed, msg = %s\n", ERR_error_string(ERR_peek_last_error(), NULL));
677 		return NULL;
678 	}
679 	SSL_set_fd(ssl, fd);
680 	SSL_set_app_data(ssl, impl_opts);
681 	SSL_set_psk_client_callback(ssl, posix_sock_tls_psk_client_cb);
682 	SPDK_DEBUGLOG(sock_posix, "SSL object creation finished: %p\n", ssl);
683 	SPDK_DEBUGLOG(sock_posix, "%s = SSL_state_string_long(%p)\n", SSL_state_string_long(ssl), ssl);
684 	while ((rc = SSL_connect(ssl)) != 1) {
685 		SPDK_DEBUGLOG(sock_posix, "%s = SSL_state_string_long(%p)\n", SSL_state_string_long(ssl), ssl);
686 		ssl_get_error = SSL_get_error(ssl, rc);
687 		SPDK_DEBUGLOG(sock_posix, "SSL_connect failed %d = SSL_connect(%p), %d = SSL_get_error(%p, %d)\n",
688 			      rc, ssl, ssl_get_error, ssl, rc);
689 		switch (ssl_get_error) {
690 		case SSL_ERROR_WANT_READ:
691 		case SSL_ERROR_WANT_WRITE:
692 			continue;
693 		default:
694 			break;
695 		}
696 		SPDK_ERRLOG("SSL_connect() failed, errno = %d\n", errno);
697 		SSL_free(ssl);
698 		return NULL;
699 	}
700 	SPDK_DEBUGLOG(sock_posix, "%s = SSL_state_string_long(%p)\n", SSL_state_string_long(ssl), ssl);
701 	SPDK_DEBUGLOG(sock_posix, "Negotiated Cipher suite:%s\n",
702 		      SSL_CIPHER_get_name(SSL_get_current_cipher(ssl)));
703 	return ssl;
704 }
705 
706 static SSL *
707 ssl_sock_accept_loop(SSL_CTX *ctx, int fd, struct spdk_sock_impl_opts *impl_opts)
708 {
709 	int rc;
710 	SSL *ssl;
711 	int ssl_get_error;
712 
713 	ssl = SSL_new(ctx);
714 	if (!ssl) {
715 		SPDK_ERRLOG("SSL_new() failed, msg = %s\n", ERR_error_string(ERR_peek_last_error(), NULL));
716 		return NULL;
717 	}
718 	SSL_set_fd(ssl, fd);
719 	SSL_set_app_data(ssl, impl_opts);
720 	SSL_set_psk_server_callback(ssl, posix_sock_tls_psk_server_cb);
721 	SPDK_DEBUGLOG(sock_posix, "SSL object creation finished: %p\n", ssl);
722 	SPDK_DEBUGLOG(sock_posix, "%s = SSL_state_string_long(%p)\n", SSL_state_string_long(ssl), ssl);
723 	while ((rc = SSL_accept(ssl)) != 1) {
724 		SPDK_DEBUGLOG(sock_posix, "%s = SSL_state_string_long(%p)\n", SSL_state_string_long(ssl), ssl);
725 		ssl_get_error = SSL_get_error(ssl, rc);
726 		SPDK_DEBUGLOG(sock_posix, "SSL_accept failed %d = SSL_accept(%p), %d = SSL_get_error(%p, %d)\n", rc,
727 			      ssl, ssl_get_error, ssl, rc);
728 		switch (ssl_get_error) {
729 		case SSL_ERROR_WANT_READ:
730 		case SSL_ERROR_WANT_WRITE:
731 			continue;
732 		default:
733 			break;
734 		}
735 		SPDK_ERRLOG("SSL_accept() failed, errno = %d\n", errno);
736 		SSL_free(ssl);
737 		return NULL;
738 	}
739 	SPDK_DEBUGLOG(sock_posix, "%s = SSL_state_string_long(%p)\n", SSL_state_string_long(ssl), ssl);
740 	SPDK_DEBUGLOG(sock_posix, "Negotiated Cipher suite:%s\n",
741 		      SSL_CIPHER_get_name(SSL_get_current_cipher(ssl)));
742 	return ssl;
743 }
744 
745 static ssize_t
746 SSL_readv(SSL *ssl, const struct iovec *iov, int iovcnt)
747 {
748 	int i, rc = 0;
749 	ssize_t total = 0;
750 
751 	for (i = 0; i < iovcnt; i++) {
752 		rc = SSL_read(ssl, iov[i].iov_base, iov[i].iov_len);
753 
754 		if (rc > 0) {
755 			total += rc;
756 		}
757 		if (rc != (int)iov[i].iov_len) {
758 			break;
759 		}
760 	}
761 	if (total > 0) {
762 		errno = 0;
763 		return total;
764 	}
765 	switch (SSL_get_error(ssl, rc)) {
766 	case SSL_ERROR_ZERO_RETURN:
767 		errno = ENOTCONN;
768 		return 0;
769 	case SSL_ERROR_WANT_READ:
770 	case SSL_ERROR_WANT_WRITE:
771 	case SSL_ERROR_WANT_CONNECT:
772 	case SSL_ERROR_WANT_ACCEPT:
773 	case SSL_ERROR_WANT_X509_LOOKUP:
774 	case SSL_ERROR_WANT_ASYNC:
775 	case SSL_ERROR_WANT_ASYNC_JOB:
776 	case SSL_ERROR_WANT_CLIENT_HELLO_CB:
777 		errno = EAGAIN;
778 		return -1;
779 	case SSL_ERROR_SYSCALL:
780 	case SSL_ERROR_SSL:
781 		errno = ENOTCONN;
782 		return -1;
783 	default:
784 		errno = ENOTCONN;
785 		return -1;
786 	}
787 }
788 
789 static ssize_t
790 SSL_writev(SSL *ssl, struct iovec *iov, int iovcnt)
791 {
792 	int i, rc = 0;
793 	ssize_t total = 0;
794 
795 	for (i = 0; i < iovcnt; i++) {
796 		rc = SSL_write(ssl, iov[i].iov_base, iov[i].iov_len);
797 
798 		if (rc > 0) {
799 			total += rc;
800 		}
801 		if (rc != (int)iov[i].iov_len) {
802 			break;
803 		}
804 	}
805 	if (total > 0) {
806 		errno = 0;
807 		return total;
808 	}
809 	switch (SSL_get_error(ssl, rc)) {
810 	case SSL_ERROR_ZERO_RETURN:
811 		errno = ENOTCONN;
812 		return 0;
813 	case SSL_ERROR_WANT_READ:
814 	case SSL_ERROR_WANT_WRITE:
815 	case SSL_ERROR_WANT_CONNECT:
816 	case SSL_ERROR_WANT_ACCEPT:
817 	case SSL_ERROR_WANT_X509_LOOKUP:
818 	case SSL_ERROR_WANT_ASYNC:
819 	case SSL_ERROR_WANT_ASYNC_JOB:
820 	case SSL_ERROR_WANT_CLIENT_HELLO_CB:
821 		errno = EAGAIN;
822 		return -1;
823 	case SSL_ERROR_SYSCALL:
824 	case SSL_ERROR_SSL:
825 		errno = ENOTCONN;
826 		return -1;
827 	default:
828 		errno = ENOTCONN;
829 		return -1;
830 	}
831 }
832 
833 static struct spdk_sock *
834 posix_sock_create(const char *ip, int port,
835 		  enum posix_sock_create_type type,
836 		  struct spdk_sock_opts *opts,
837 		  bool enable_ssl)
838 {
839 	struct spdk_posix_sock *sock;
840 	struct spdk_sock_impl_opts impl_opts;
841 	char buf[MAX_TMPBUF];
842 	char portnum[PORTNUMLEN];
843 	char *p;
844 	struct addrinfo hints, *res, *res0;
845 	int fd, flag;
846 	int rc;
847 	bool enable_zcopy_user_opts = true;
848 	bool enable_zcopy_impl_opts = true;
849 	SSL_CTX *ctx = 0;
850 	SSL *ssl = 0;
851 
852 	assert(opts != NULL);
853 	posix_opts_get_impl_opts(opts, &impl_opts);
854 
855 	if (ip == NULL) {
856 		return NULL;
857 	}
858 	if (ip[0] == '[') {
859 		snprintf(buf, sizeof(buf), "%s", ip + 1);
860 		p = strchr(buf, ']');
861 		if (p != NULL) {
862 			*p = '\0';
863 		}
864 		ip = (const char *) &buf[0];
865 	}
866 
867 	snprintf(portnum, sizeof portnum, "%d", port);
868 	memset(&hints, 0, sizeof hints);
869 	hints.ai_family = PF_UNSPEC;
870 	hints.ai_socktype = SOCK_STREAM;
871 	hints.ai_flags = AI_NUMERICSERV;
872 	hints.ai_flags |= AI_PASSIVE;
873 	hints.ai_flags |= AI_NUMERICHOST;
874 	rc = getaddrinfo(ip, portnum, &hints, &res0);
875 	if (rc != 0) {
876 		SPDK_ERRLOG("getaddrinfo() failed %s (%d)\n", gai_strerror(rc), rc);
877 		return NULL;
878 	}
879 
880 	/* try listen */
881 	fd = -1;
882 	for (res = res0; res != NULL; res = res->ai_next) {
883 retry:
884 		fd = posix_fd_create(res, opts, &impl_opts);
885 		if (fd < 0) {
886 			continue;
887 		}
888 		if (type == SPDK_SOCK_CREATE_LISTEN) {
889 			if (enable_ssl) {
890 				ctx = posix_sock_create_ssl_context(TLS_server_method(), opts, &impl_opts);
891 				if (!ctx) {
892 					SPDK_ERRLOG("posix_sock_create_ssl_context() failed, errno = %d\n", errno);
893 					close(fd);
894 					fd = -1;
895 					break;
896 				}
897 			}
898 			rc = bind(fd, res->ai_addr, res->ai_addrlen);
899 			if (rc != 0) {
900 				SPDK_ERRLOG("bind() failed at port %d, errno = %d\n", port, errno);
901 				switch (errno) {
902 				case EINTR:
903 					/* interrupted? */
904 					close(fd);
905 					goto retry;
906 				case EADDRNOTAVAIL:
907 					SPDK_ERRLOG("IP address %s not available. "
908 						    "Verify IP address in config file "
909 						    "and make sure setup script is "
910 						    "run before starting spdk app.\n", ip);
911 				/* FALLTHROUGH */
912 				default:
913 					/* try next family */
914 					close(fd);
915 					fd = -1;
916 					continue;
917 				}
918 			}
919 			/* bind OK */
920 			rc = listen(fd, 512);
921 			if (rc != 0) {
922 				SPDK_ERRLOG("listen() failed, errno = %d\n", errno);
923 				close(fd);
924 				fd = -1;
925 				break;
926 			}
927 			enable_zcopy_impl_opts = impl_opts.enable_zerocopy_send_server;
928 		} else if (type == SPDK_SOCK_CREATE_CONNECT) {
929 			rc = connect(fd, res->ai_addr, res->ai_addrlen);
930 			if (rc != 0) {
931 				SPDK_ERRLOG("connect() failed, errno = %d\n", errno);
932 				/* try next family */
933 				close(fd);
934 				fd = -1;
935 				continue;
936 			}
937 			enable_zcopy_impl_opts = impl_opts.enable_zerocopy_send_client;
938 			if (enable_ssl) {
939 				ctx = posix_sock_create_ssl_context(TLS_client_method(), opts, &impl_opts);
940 				if (!ctx) {
941 					SPDK_ERRLOG("posix_sock_create_ssl_context() failed, errno = %d\n", errno);
942 					close(fd);
943 					fd = -1;
944 					break;
945 				}
946 				ssl = ssl_sock_connect_loop(ctx, fd, &impl_opts);
947 				if (!ssl) {
948 					SPDK_ERRLOG("ssl_sock_connect_loop() failed, errno = %d\n", errno);
949 					close(fd);
950 					fd = -1;
951 					SSL_CTX_free(ctx);
952 					break;
953 				}
954 			}
955 		}
956 
957 		flag = fcntl(fd, F_GETFL);
958 		if (fcntl(fd, F_SETFL, flag | O_NONBLOCK) < 0) {
959 			SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%d)\n", fd, errno);
960 			close(fd);
961 			fd = -1;
962 			break;
963 		}
964 		break;
965 	}
966 	freeaddrinfo(res0);
967 
968 	if (fd < 0) {
969 		return NULL;
970 	}
971 
972 	/* Only enable zero copy for non-loopback and non-ssl sockets. */
973 	enable_zcopy_user_opts = opts->zcopy && !sock_is_loopback(fd) && !enable_ssl;
974 
975 	sock = posix_sock_alloc(fd, &impl_opts, enable_zcopy_user_opts && enable_zcopy_impl_opts);
976 	if (sock == NULL) {
977 		SPDK_ERRLOG("sock allocation failed\n");
978 		close(fd);
979 		return NULL;
980 	}
981 
982 	if (ctx) {
983 		sock->ctx = ctx;
984 	}
985 
986 	if (ssl) {
987 		sock->ssl = ssl;
988 	}
989 
990 	return &sock->base;
991 }
992 
993 static struct spdk_sock *
994 posix_sock_listen(const char *ip, int port, struct spdk_sock_opts *opts)
995 {
996 	return posix_sock_create(ip, port, SPDK_SOCK_CREATE_LISTEN, opts, false);
997 }
998 
999 static struct spdk_sock *
1000 posix_sock_connect(const char *ip, int port, struct spdk_sock_opts *opts)
1001 {
1002 	return posix_sock_create(ip, port, SPDK_SOCK_CREATE_CONNECT, opts, false);
1003 }
1004 
1005 static struct spdk_sock *
1006 posix_sock_accept(struct spdk_sock *_sock)
1007 {
1008 	struct spdk_posix_sock		*sock = __posix_sock(_sock);
1009 	struct sockaddr_storage		sa;
1010 	socklen_t			salen;
1011 	int				rc, fd;
1012 	struct spdk_posix_sock		*new_sock;
1013 	int				flag;
1014 	SSL *ssl = 0;
1015 
1016 	memset(&sa, 0, sizeof(sa));
1017 	salen = sizeof(sa);
1018 
1019 	assert(sock != NULL);
1020 
1021 	rc = accept(sock->fd, (struct sockaddr *)&sa, &salen);
1022 
1023 	if (rc == -1) {
1024 		return NULL;
1025 	}
1026 
1027 	fd = rc;
1028 
1029 	flag = fcntl(fd, F_GETFL);
1030 	if ((!(flag & O_NONBLOCK)) && (fcntl(fd, F_SETFL, flag | O_NONBLOCK) < 0)) {
1031 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%d)\n", fd, errno);
1032 		close(fd);
1033 		return NULL;
1034 	}
1035 
1036 #if defined(SO_PRIORITY)
1037 	/* The priority is not inherited, so call this function again */
1038 	if (sock->base.opts.priority) {
1039 		rc = setsockopt(fd, SOL_SOCKET, SO_PRIORITY, &sock->base.opts.priority, sizeof(int));
1040 		if (rc != 0) {
1041 			close(fd);
1042 			return NULL;
1043 		}
1044 	}
1045 #endif
1046 
1047 	/* Establish SSL connection */
1048 	if (sock->ctx) {
1049 		ssl = ssl_sock_accept_loop(sock->ctx, fd, &sock->base.impl_opts);
1050 		if (!ssl) {
1051 			SPDK_ERRLOG("ssl_sock_accept_loop() failed, errno = %d\n", errno);
1052 			close(fd);
1053 			return NULL;
1054 		}
1055 	}
1056 
1057 	/* Inherit the zero copy feature from the listen socket */
1058 	new_sock = posix_sock_alloc(fd, &sock->base.impl_opts, sock->zcopy);
1059 	if (new_sock == NULL) {
1060 		close(fd);
1061 		return NULL;
1062 	}
1063 
1064 	if (sock->ctx) {
1065 		new_sock->ctx = sock->ctx;
1066 	}
1067 
1068 	if (ssl) {
1069 		new_sock->ssl = ssl;
1070 	}
1071 
1072 	return &new_sock->base;
1073 }
1074 
1075 static int
1076 posix_sock_close(struct spdk_sock *_sock)
1077 {
1078 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1079 
1080 	assert(TAILQ_EMPTY(&_sock->pending_reqs));
1081 
1082 	/* If the socket fails to close, the best choice is to
1083 	 * leak the fd but continue to free the rest of the sock
1084 	 * memory. */
1085 	close(sock->fd);
1086 
1087 	spdk_pipe_destroy(sock->recv_pipe);
1088 	free(sock->recv_buf);
1089 	free(sock);
1090 
1091 	return 0;
1092 }
1093 
1094 #ifdef SPDK_ZEROCOPY
1095 static int
1096 _sock_check_zcopy(struct spdk_sock *sock)
1097 {
1098 	struct spdk_posix_sock *psock = __posix_sock(sock);
1099 	struct msghdr msgh = {};
1100 	uint8_t buf[sizeof(struct cmsghdr) + sizeof(struct sock_extended_err)];
1101 	ssize_t rc;
1102 	struct sock_extended_err *serr;
1103 	struct cmsghdr *cm;
1104 	uint32_t idx;
1105 	struct spdk_sock_request *req, *treq;
1106 	bool found;
1107 
1108 	msgh.msg_control = buf;
1109 	msgh.msg_controllen = sizeof(buf);
1110 
1111 	while (true) {
1112 		rc = recvmsg(psock->fd, &msgh, MSG_ERRQUEUE);
1113 
1114 		if (rc < 0) {
1115 			if (errno == EWOULDBLOCK || errno == EAGAIN) {
1116 				return 0;
1117 			}
1118 
1119 			if (!TAILQ_EMPTY(&sock->pending_reqs)) {
1120 				SPDK_ERRLOG("Attempting to receive from ERRQUEUE yielded error, but pending list still has orphaned entries\n");
1121 			} else {
1122 				SPDK_WARNLOG("Recvmsg yielded an error!\n");
1123 			}
1124 			return 0;
1125 		}
1126 
1127 		cm = CMSG_FIRSTHDR(&msgh);
1128 		if (!(cm &&
1129 		      ((cm->cmsg_level == SOL_IP && cm->cmsg_type == IP_RECVERR) ||
1130 		       (cm->cmsg_level == SOL_IPV6 && cm->cmsg_type == IPV6_RECVERR)))) {
1131 			SPDK_WARNLOG("Unexpected cmsg level or type!\n");
1132 			return 0;
1133 		}
1134 
1135 		serr = (struct sock_extended_err *)CMSG_DATA(cm);
1136 		if (serr->ee_errno != 0 || serr->ee_origin != SO_EE_ORIGIN_ZEROCOPY) {
1137 			SPDK_WARNLOG("Unexpected extended error origin\n");
1138 			return 0;
1139 		}
1140 
1141 		/* Most of the time, the pending_reqs array is in the exact
1142 		 * order we need such that all of the requests to complete are
1143 		 * in order, in the front. It is guaranteed that all requests
1144 		 * belonging to the same sendmsg call are sequential, so once
1145 		 * we encounter one match we can stop looping as soon as a
1146 		 * non-match is found.
1147 		 */
1148 		for (idx = serr->ee_info; idx <= serr->ee_data; idx++) {
1149 			found = false;
1150 			TAILQ_FOREACH_SAFE(req, &sock->pending_reqs, internal.link, treq) {
1151 				if (!req->internal.is_zcopy) {
1152 					/* This wasn't a zcopy request. It was just waiting in line to complete */
1153 					rc = spdk_sock_request_put(sock, req, 0);
1154 					if (rc < 0) {
1155 						return rc;
1156 					}
1157 				} else if (req->internal.offset == idx) {
1158 					found = true;
1159 					rc = spdk_sock_request_put(sock, req, 0);
1160 					if (rc < 0) {
1161 						return rc;
1162 					}
1163 				} else if (found) {
1164 					break;
1165 				}
1166 			}
1167 		}
1168 	}
1169 
1170 	return 0;
1171 }
1172 #endif
1173 
1174 static int
1175 _sock_flush(struct spdk_sock *sock)
1176 {
1177 	struct spdk_posix_sock *psock = __posix_sock(sock);
1178 	struct msghdr msg = {};
1179 	int flags;
1180 	struct iovec iovs[IOV_BATCH_SIZE];
1181 	int iovcnt;
1182 	int retval;
1183 	struct spdk_sock_request *req;
1184 	int i;
1185 	ssize_t rc;
1186 	unsigned int offset;
1187 	size_t len;
1188 	bool is_zcopy = false;
1189 
1190 	/* Can't flush from within a callback or we end up with recursive calls */
1191 	if (sock->cb_cnt > 0) {
1192 		return 0;
1193 	}
1194 
1195 #ifdef SPDK_ZEROCOPY
1196 	if (psock->zcopy) {
1197 		flags = MSG_ZEROCOPY | MSG_NOSIGNAL;
1198 	} else
1199 #endif
1200 	{
1201 		flags = MSG_NOSIGNAL;
1202 	}
1203 
1204 	iovcnt = spdk_sock_prep_reqs(sock, iovs, 0, NULL, &flags);
1205 	if (iovcnt == 0) {
1206 		return 0;
1207 	}
1208 
1209 #ifdef SPDK_ZEROCOPY
1210 	is_zcopy = flags & MSG_ZEROCOPY;
1211 #endif
1212 
1213 	/* Perform the vectored write */
1214 	msg.msg_iov = iovs;
1215 	msg.msg_iovlen = iovcnt;
1216 
1217 	if (psock->ssl) {
1218 		rc = SSL_writev(psock->ssl, iovs, iovcnt);
1219 	} else {
1220 		rc = sendmsg(psock->fd, &msg, flags);
1221 	}
1222 	if (rc <= 0) {
1223 		if (errno == EAGAIN || errno == EWOULDBLOCK || (errno == ENOBUFS && psock->zcopy)) {
1224 			return 0;
1225 		}
1226 		return rc;
1227 	}
1228 
1229 	if (is_zcopy) {
1230 		/* Handling overflow case, because we use psock->sendmsg_idx - 1 for the
1231 		 * req->internal.offset, so sendmsg_idx should not be zero  */
1232 		if (spdk_unlikely(psock->sendmsg_idx == UINT32_MAX)) {
1233 			psock->sendmsg_idx = 1;
1234 		} else {
1235 			psock->sendmsg_idx++;
1236 		}
1237 	}
1238 
1239 	/* Consume the requests that were actually written */
1240 	req = TAILQ_FIRST(&sock->queued_reqs);
1241 	while (req) {
1242 		offset = req->internal.offset;
1243 
1244 		/* req->internal.is_zcopy is true when the whole req or part of it is sent with zerocopy */
1245 		req->internal.is_zcopy = is_zcopy;
1246 
1247 		for (i = 0; i < req->iovcnt; i++) {
1248 			/* Advance by the offset first */
1249 			if (offset >= SPDK_SOCK_REQUEST_IOV(req, i)->iov_len) {
1250 				offset -= SPDK_SOCK_REQUEST_IOV(req, i)->iov_len;
1251 				continue;
1252 			}
1253 
1254 			/* Calculate the remaining length of this element */
1255 			len = SPDK_SOCK_REQUEST_IOV(req, i)->iov_len - offset;
1256 
1257 			if (len > (size_t)rc) {
1258 				/* This element was partially sent. */
1259 				req->internal.offset += rc;
1260 				return 0;
1261 			}
1262 
1263 			offset = 0;
1264 			req->internal.offset += len;
1265 			rc -= len;
1266 		}
1267 
1268 		/* Handled a full request. */
1269 		spdk_sock_request_pend(sock, req);
1270 
1271 		if (!req->internal.is_zcopy && req == TAILQ_FIRST(&sock->pending_reqs)) {
1272 			/* The sendmsg syscall above isn't currently asynchronous,
1273 			* so it's already done. */
1274 			retval = spdk_sock_request_put(sock, req, 0);
1275 			if (retval) {
1276 				break;
1277 			}
1278 		} else {
1279 			/* Re-use the offset field to hold the sendmsg call index. The
1280 			 * index is 0 based, so subtract one here because we've already
1281 			 * incremented above. */
1282 			req->internal.offset = psock->sendmsg_idx - 1;
1283 		}
1284 
1285 		if (rc == 0) {
1286 			break;
1287 		}
1288 
1289 		req = TAILQ_FIRST(&sock->queued_reqs);
1290 	}
1291 
1292 	return 0;
1293 }
1294 
1295 static int
1296 posix_sock_flush(struct spdk_sock *sock)
1297 {
1298 #ifdef SPDK_ZEROCOPY
1299 	struct spdk_posix_sock *psock = __posix_sock(sock);
1300 
1301 	if (psock->zcopy && !TAILQ_EMPTY(&sock->pending_reqs)) {
1302 		_sock_check_zcopy(sock);
1303 	}
1304 #endif
1305 
1306 	return _sock_flush(sock);
1307 }
1308 
1309 static ssize_t
1310 posix_sock_recv_from_pipe(struct spdk_posix_sock *sock, struct iovec *diov, int diovcnt)
1311 {
1312 	struct iovec siov[2];
1313 	int sbytes;
1314 	ssize_t bytes;
1315 	struct spdk_posix_sock_group_impl *group;
1316 
1317 	sbytes = spdk_pipe_reader_get_buffer(sock->recv_pipe, sock->recv_buf_sz, siov);
1318 	if (sbytes < 0) {
1319 		errno = EINVAL;
1320 		return -1;
1321 	} else if (sbytes == 0) {
1322 		errno = EAGAIN;
1323 		return -1;
1324 	}
1325 
1326 	bytes = spdk_iovcpy(siov, 2, diov, diovcnt);
1327 
1328 	if (bytes == 0) {
1329 		/* The only way this happens is if diov is 0 length */
1330 		errno = EINVAL;
1331 		return -1;
1332 	}
1333 
1334 	spdk_pipe_reader_advance(sock->recv_pipe, bytes);
1335 
1336 	/* If we drained the pipe, mark it appropriately */
1337 	if (spdk_pipe_reader_bytes_available(sock->recv_pipe) == 0) {
1338 		assert(sock->pipe_has_data == true);
1339 
1340 		group = __posix_group_impl(sock->base.group_impl);
1341 		if (group && !sock->socket_has_data) {
1342 			TAILQ_REMOVE(&group->socks_with_data, sock, link);
1343 		}
1344 
1345 		sock->pipe_has_data = false;
1346 	}
1347 
1348 	return bytes;
1349 }
1350 
1351 static inline ssize_t
1352 posix_sock_read(struct spdk_posix_sock *sock)
1353 {
1354 	struct iovec iov[2];
1355 	int bytes_avail, bytes_recvd;
1356 	struct spdk_posix_sock_group_impl *group;
1357 
1358 	bytes_avail = spdk_pipe_writer_get_buffer(sock->recv_pipe, sock->recv_buf_sz, iov);
1359 
1360 	if (bytes_avail <= 0) {
1361 		return bytes_avail;
1362 	}
1363 
1364 	if (sock->ssl) {
1365 		bytes_recvd = SSL_readv(sock->ssl, iov, 2);
1366 	} else {
1367 		bytes_recvd = readv(sock->fd, iov, 2);
1368 	}
1369 
1370 	assert(sock->pipe_has_data == false);
1371 
1372 	if (bytes_recvd <= 0) {
1373 		/* Errors count as draining the socket data */
1374 		if (sock->base.group_impl && sock->socket_has_data) {
1375 			group = __posix_group_impl(sock->base.group_impl);
1376 			TAILQ_REMOVE(&group->socks_with_data, sock, link);
1377 		}
1378 
1379 		sock->socket_has_data = false;
1380 
1381 		return bytes_recvd;
1382 	}
1383 
1384 	spdk_pipe_writer_advance(sock->recv_pipe, bytes_recvd);
1385 
1386 #if DEBUG
1387 	if (sock->base.group_impl) {
1388 		assert(sock->socket_has_data == true);
1389 	}
1390 #endif
1391 
1392 	sock->pipe_has_data = true;
1393 	if (bytes_recvd < bytes_avail) {
1394 		/* We drained the kernel socket entirely. */
1395 		sock->socket_has_data = false;
1396 	}
1397 
1398 	return bytes_recvd;
1399 }
1400 
1401 static ssize_t
1402 posix_sock_readv(struct spdk_sock *_sock, struct iovec *iov, int iovcnt)
1403 {
1404 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1405 	struct spdk_posix_sock_group_impl *group = __posix_group_impl(sock->base.group_impl);
1406 	int rc, i;
1407 	size_t len;
1408 
1409 	if (sock->recv_pipe == NULL) {
1410 		assert(sock->pipe_has_data == false);
1411 		if (group && sock->socket_has_data) {
1412 			sock->socket_has_data = false;
1413 			TAILQ_REMOVE(&group->socks_with_data, sock, link);
1414 		}
1415 		if (sock->ssl) {
1416 			return SSL_readv(sock->ssl, iov, iovcnt);
1417 		} else {
1418 			return readv(sock->fd, iov, iovcnt);
1419 		}
1420 	}
1421 
1422 	/* If the socket is not in a group, we must assume it always has
1423 	 * data waiting for us because it is not epolled */
1424 	if (!sock->pipe_has_data && (group == NULL || sock->socket_has_data)) {
1425 		/* If the user is receiving a sufficiently large amount of data,
1426 		 * receive directly to their buffers. */
1427 		len = 0;
1428 		for (i = 0; i < iovcnt; i++) {
1429 			len += iov[i].iov_len;
1430 		}
1431 
1432 		if (len >= MIN_SOCK_PIPE_SIZE) {
1433 			/* TODO: Should this detect if kernel socket is drained? */
1434 			if (sock->ssl) {
1435 				return SSL_readv(sock->ssl, iov, iovcnt);
1436 			} else {
1437 				return readv(sock->fd, iov, iovcnt);
1438 			}
1439 		}
1440 
1441 		/* Otherwise, do a big read into our pipe */
1442 		rc = posix_sock_read(sock);
1443 		if (rc <= 0) {
1444 			return rc;
1445 		}
1446 	}
1447 
1448 	return posix_sock_recv_from_pipe(sock, iov, iovcnt);
1449 }
1450 
1451 static ssize_t
1452 posix_sock_recv(struct spdk_sock *sock, void *buf, size_t len)
1453 {
1454 	struct iovec iov[1];
1455 
1456 	iov[0].iov_base = buf;
1457 	iov[0].iov_len = len;
1458 
1459 	return posix_sock_readv(sock, iov, 1);
1460 }
1461 
1462 static void
1463 posix_sock_readv_async(struct spdk_sock *sock, struct spdk_sock_request *req)
1464 {
1465 	req->cb_fn(req->cb_arg, -ENOTSUP);
1466 }
1467 
1468 static ssize_t
1469 posix_sock_writev(struct spdk_sock *_sock, struct iovec *iov, int iovcnt)
1470 {
1471 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1472 	int rc;
1473 
1474 	/* In order to process a writev, we need to flush any asynchronous writes
1475 	 * first. */
1476 	rc = _sock_flush(_sock);
1477 	if (rc < 0) {
1478 		return rc;
1479 	}
1480 
1481 	if (!TAILQ_EMPTY(&_sock->queued_reqs)) {
1482 		/* We weren't able to flush all requests */
1483 		errno = EAGAIN;
1484 		return -1;
1485 	}
1486 
1487 	if (sock->ssl) {
1488 		return SSL_writev(sock->ssl, iov, iovcnt);
1489 	} else {
1490 		return writev(sock->fd, iov, iovcnt);
1491 	}
1492 }
1493 
1494 static void
1495 posix_sock_writev_async(struct spdk_sock *sock, struct spdk_sock_request *req)
1496 {
1497 	int rc;
1498 
1499 	spdk_sock_request_queue(sock, req);
1500 
1501 	/* If there are a sufficient number queued, just flush them out immediately. */
1502 	if (sock->queued_iovcnt >= IOV_BATCH_SIZE) {
1503 		rc = _sock_flush(sock);
1504 		if (rc) {
1505 			spdk_sock_abort_requests(sock);
1506 		}
1507 	}
1508 }
1509 
1510 static int
1511 posix_sock_set_recvlowat(struct spdk_sock *_sock, int nbytes)
1512 {
1513 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1514 	int val;
1515 	int rc;
1516 
1517 	assert(sock != NULL);
1518 
1519 	val = nbytes;
1520 	rc = setsockopt(sock->fd, SOL_SOCKET, SO_RCVLOWAT, &val, sizeof val);
1521 	if (rc != 0) {
1522 		return -1;
1523 	}
1524 	return 0;
1525 }
1526 
1527 static bool
1528 posix_sock_is_ipv6(struct spdk_sock *_sock)
1529 {
1530 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1531 	struct sockaddr_storage sa;
1532 	socklen_t salen;
1533 	int rc;
1534 
1535 	assert(sock != NULL);
1536 
1537 	memset(&sa, 0, sizeof sa);
1538 	salen = sizeof sa;
1539 	rc = getsockname(sock->fd, (struct sockaddr *) &sa, &salen);
1540 	if (rc != 0) {
1541 		SPDK_ERRLOG("getsockname() failed (errno=%d)\n", errno);
1542 		return false;
1543 	}
1544 
1545 	return (sa.ss_family == AF_INET6);
1546 }
1547 
1548 static bool
1549 posix_sock_is_ipv4(struct spdk_sock *_sock)
1550 {
1551 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1552 	struct sockaddr_storage sa;
1553 	socklen_t salen;
1554 	int rc;
1555 
1556 	assert(sock != NULL);
1557 
1558 	memset(&sa, 0, sizeof sa);
1559 	salen = sizeof sa;
1560 	rc = getsockname(sock->fd, (struct sockaddr *) &sa, &salen);
1561 	if (rc != 0) {
1562 		SPDK_ERRLOG("getsockname() failed (errno=%d)\n", errno);
1563 		return false;
1564 	}
1565 
1566 	return (sa.ss_family == AF_INET);
1567 }
1568 
1569 static bool
1570 posix_sock_is_connected(struct spdk_sock *_sock)
1571 {
1572 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1573 	uint8_t byte;
1574 	int rc;
1575 
1576 	rc = recv(sock->fd, &byte, 1, MSG_PEEK);
1577 	if (rc == 0) {
1578 		return false;
1579 	}
1580 
1581 	if (rc < 0) {
1582 		if (errno == EAGAIN || errno == EWOULDBLOCK) {
1583 			return true;
1584 		}
1585 
1586 		return false;
1587 	}
1588 
1589 	return true;
1590 }
1591 
1592 static struct spdk_sock_group_impl *
1593 posix_sock_group_impl_get_optimal(struct spdk_sock *_sock, struct spdk_sock_group_impl *hint)
1594 {
1595 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1596 	struct spdk_sock_group_impl *group_impl;
1597 
1598 	if (sock->placement_id != -1) {
1599 		spdk_sock_map_lookup(&g_map, sock->placement_id, &group_impl, hint);
1600 		return group_impl;
1601 	}
1602 
1603 	return NULL;
1604 }
1605 
1606 static struct spdk_sock_group_impl *
1607 posix_sock_group_impl_create(void)
1608 {
1609 	struct spdk_posix_sock_group_impl *group_impl;
1610 	int fd;
1611 
1612 #if defined(SPDK_EPOLL)
1613 	fd = epoll_create1(0);
1614 #elif defined(SPDK_KEVENT)
1615 	fd = kqueue();
1616 #endif
1617 	if (fd == -1) {
1618 		return NULL;
1619 	}
1620 
1621 	group_impl = calloc(1, sizeof(*group_impl));
1622 	if (group_impl == NULL) {
1623 		SPDK_ERRLOG("group_impl allocation failed\n");
1624 		close(fd);
1625 		return NULL;
1626 	}
1627 
1628 	group_impl->fd = fd;
1629 	TAILQ_INIT(&group_impl->socks_with_data);
1630 	group_impl->placement_id = -1;
1631 
1632 	if (g_spdk_posix_sock_impl_opts.enable_placement_id == PLACEMENT_CPU) {
1633 		spdk_sock_map_insert(&g_map, spdk_env_get_current_core(), &group_impl->base);
1634 		group_impl->placement_id = spdk_env_get_current_core();
1635 	}
1636 
1637 	return &group_impl->base;
1638 }
1639 
1640 static void
1641 posix_sock_mark(struct spdk_posix_sock_group_impl *group, struct spdk_posix_sock *sock,
1642 		int placement_id)
1643 {
1644 #if defined(SO_MARK)
1645 	int rc;
1646 
1647 	rc = setsockopt(sock->fd, SOL_SOCKET, SO_MARK,
1648 			&placement_id, sizeof(placement_id));
1649 	if (rc != 0) {
1650 		/* Not fatal */
1651 		SPDK_ERRLOG("Error setting SO_MARK\n");
1652 		return;
1653 	}
1654 
1655 	rc = spdk_sock_map_insert(&g_map, placement_id, &group->base);
1656 	if (rc != 0) {
1657 		/* Not fatal */
1658 		SPDK_ERRLOG("Failed to insert sock group into map: %d\n", rc);
1659 		return;
1660 	}
1661 
1662 	sock->placement_id = placement_id;
1663 #endif
1664 }
1665 
1666 static void
1667 posix_sock_update_mark(struct spdk_sock_group_impl *_group, struct spdk_sock *_sock)
1668 {
1669 	struct spdk_posix_sock_group_impl *group = __posix_group_impl(_group);
1670 
1671 	if (group->placement_id == -1) {
1672 		group->placement_id = spdk_sock_map_find_free(&g_map);
1673 
1674 		/* If a free placement id is found, update existing sockets in this group */
1675 		if (group->placement_id != -1) {
1676 			struct spdk_sock  *sock, *tmp;
1677 
1678 			TAILQ_FOREACH_SAFE(sock, &_group->socks, link, tmp) {
1679 				posix_sock_mark(group, __posix_sock(sock), group->placement_id);
1680 			}
1681 		}
1682 	}
1683 
1684 	if (group->placement_id != -1) {
1685 		/*
1686 		 * group placement id is already determined for this poll group.
1687 		 * Mark socket with group's placement id.
1688 		 */
1689 		posix_sock_mark(group, __posix_sock(_sock), group->placement_id);
1690 	}
1691 }
1692 
1693 static int
1694 posix_sock_group_impl_add_sock(struct spdk_sock_group_impl *_group, struct spdk_sock *_sock)
1695 {
1696 	struct spdk_posix_sock_group_impl *group = __posix_group_impl(_group);
1697 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1698 	int rc;
1699 
1700 #if defined(SPDK_EPOLL)
1701 	struct epoll_event event;
1702 
1703 	memset(&event, 0, sizeof(event));
1704 	/* EPOLLERR is always on even if we don't set it, but be explicit for clarity */
1705 	event.events = EPOLLIN | EPOLLERR;
1706 	event.data.ptr = sock;
1707 
1708 	rc = epoll_ctl(group->fd, EPOLL_CTL_ADD, sock->fd, &event);
1709 #elif defined(SPDK_KEVENT)
1710 	struct kevent event;
1711 	struct timespec ts = {0};
1712 
1713 	EV_SET(&event, sock->fd, EVFILT_READ, EV_ADD, 0, 0, sock);
1714 
1715 	rc = kevent(group->fd, &event, 1, NULL, 0, &ts);
1716 #endif
1717 
1718 	if (rc != 0) {
1719 		return rc;
1720 	}
1721 
1722 	/* switched from another polling group due to scheduling */
1723 	if (spdk_unlikely(sock->recv_pipe != NULL  &&
1724 			  (spdk_pipe_reader_bytes_available(sock->recv_pipe) > 0))) {
1725 		sock->pipe_has_data = true;
1726 		sock->socket_has_data = false;
1727 		TAILQ_INSERT_TAIL(&group->socks_with_data, sock, link);
1728 	}
1729 
1730 	if (g_spdk_posix_sock_impl_opts.enable_placement_id == PLACEMENT_MARK) {
1731 		posix_sock_update_mark(_group, _sock);
1732 	} else if (sock->placement_id != -1) {
1733 		rc = spdk_sock_map_insert(&g_map, sock->placement_id, &group->base);
1734 		if (rc != 0) {
1735 			SPDK_ERRLOG("Failed to insert sock group into map: %d\n", rc);
1736 			/* Do not treat this as an error. The system will continue running. */
1737 		}
1738 	}
1739 
1740 	return rc;
1741 }
1742 
1743 static int
1744 posix_sock_group_impl_remove_sock(struct spdk_sock_group_impl *_group, struct spdk_sock *_sock)
1745 {
1746 	struct spdk_posix_sock_group_impl *group = __posix_group_impl(_group);
1747 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1748 	int rc;
1749 
1750 	if (sock->pipe_has_data || sock->socket_has_data) {
1751 		TAILQ_REMOVE(&group->socks_with_data, sock, link);
1752 		sock->pipe_has_data = false;
1753 		sock->socket_has_data = false;
1754 	}
1755 
1756 	if (sock->placement_id != -1) {
1757 		spdk_sock_map_release(&g_map, sock->placement_id);
1758 	}
1759 
1760 #if defined(SPDK_EPOLL)
1761 	struct epoll_event event;
1762 
1763 	/* Event parameter is ignored but some old kernel version still require it. */
1764 	rc = epoll_ctl(group->fd, EPOLL_CTL_DEL, sock->fd, &event);
1765 #elif defined(SPDK_KEVENT)
1766 	struct kevent event;
1767 	struct timespec ts = {0};
1768 
1769 	EV_SET(&event, sock->fd, EVFILT_READ, EV_DELETE, 0, 0, NULL);
1770 
1771 	rc = kevent(group->fd, &event, 1, NULL, 0, &ts);
1772 	if (rc == 0 && event.flags & EV_ERROR) {
1773 		rc = -1;
1774 		errno = event.data;
1775 	}
1776 #endif
1777 
1778 	spdk_sock_abort_requests(_sock);
1779 
1780 	return rc;
1781 }
1782 
1783 static int
1784 posix_sock_group_impl_poll(struct spdk_sock_group_impl *_group, int max_events,
1785 			   struct spdk_sock **socks)
1786 {
1787 	struct spdk_posix_sock_group_impl *group = __posix_group_impl(_group);
1788 	struct spdk_sock *sock, *tmp;
1789 	int num_events, i, rc;
1790 	struct spdk_posix_sock *psock, *ptmp;
1791 #if defined(SPDK_EPOLL)
1792 	struct epoll_event events[MAX_EVENTS_PER_POLL];
1793 #elif defined(SPDK_KEVENT)
1794 	struct kevent events[MAX_EVENTS_PER_POLL];
1795 	struct timespec ts = {0};
1796 #endif
1797 
1798 #ifdef SPDK_ZEROCOPY
1799 	/* When all of the following conditions are met
1800 	 * - non-blocking socket
1801 	 * - zero copy is enabled
1802 	 * - interrupts suppressed (i.e. busy polling)
1803 	 * - the NIC tx queue is full at the time sendmsg() is called
1804 	 * - epoll_wait determines there is an EPOLLIN event for the socket
1805 	 * then we can get into a situation where data we've sent is queued
1806 	 * up in the kernel network stack, but interrupts have been suppressed
1807 	 * because other traffic is flowing so the kernel misses the signal
1808 	 * to flush the software tx queue. If there wasn't incoming data
1809 	 * pending on the socket, then epoll_wait would have been sufficient
1810 	 * to kick off the send operation, but since there is a pending event
1811 	 * epoll_wait does not trigger the necessary operation.
1812 	 *
1813 	 * We deal with this by checking for all of the above conditions and
1814 	 * additionally looking for EPOLLIN events that were not consumed from
1815 	 * the last poll loop. We take this to mean that the upper layer is
1816 	 * unable to consume them because it is blocked waiting for resources
1817 	 * to free up, and those resources are most likely freed in response
1818 	 * to a pending asynchronous write completing.
1819 	 *
1820 	 * Additionally, sockets that have the same placement_id actually share
1821 	 * an underlying hardware queue. That means polling one of them is
1822 	 * equivalent to polling all of them. As a quick mechanism to avoid
1823 	 * making extra poll() calls, stash the last placement_id during the loop
1824 	 * and only poll if it's not the same. The overwhelmingly common case
1825 	 * is that all sockets in this list have the same placement_id because
1826 	 * SPDK is intentionally grouping sockets by that value, so even
1827 	 * though this won't stop all extra calls to poll(), it's very fast
1828 	 * and will catch all of them in practice.
1829 	 */
1830 	int last_placement_id = -1;
1831 
1832 	TAILQ_FOREACH(psock, &group->socks_with_data, link) {
1833 		if (psock->zcopy && psock->placement_id >= 0 &&
1834 		    psock->placement_id != last_placement_id) {
1835 			struct pollfd pfd = {psock->fd, POLLIN | POLLERR, 0};
1836 
1837 			poll(&pfd, 1, 0);
1838 			last_placement_id = psock->placement_id;
1839 		}
1840 	}
1841 #endif
1842 
1843 	/* This must be a TAILQ_FOREACH_SAFE because while flushing,
1844 	 * a completion callback could remove the sock from the
1845 	 * group. */
1846 	TAILQ_FOREACH_SAFE(sock, &_group->socks, link, tmp) {
1847 		rc = _sock_flush(sock);
1848 		if (rc) {
1849 			spdk_sock_abort_requests(sock);
1850 		}
1851 	}
1852 
1853 	assert(max_events > 0);
1854 
1855 #if defined(SPDK_EPOLL)
1856 	num_events = epoll_wait(group->fd, events, max_events, 0);
1857 #elif defined(SPDK_KEVENT)
1858 	num_events = kevent(group->fd, NULL, 0, events, max_events, &ts);
1859 #endif
1860 
1861 	if (num_events == -1) {
1862 		return -1;
1863 	} else if (num_events == 0 && !TAILQ_EMPTY(&_group->socks)) {
1864 		sock = TAILQ_FIRST(&_group->socks);
1865 		psock = __posix_sock(sock);
1866 		/* poll() is called here to busy poll the queue associated with
1867 		 * first socket in list and potentially reap incoming data.
1868 		 */
1869 		if (sock->opts.priority) {
1870 			struct pollfd pfd = {0, 0, 0};
1871 
1872 			pfd.fd = psock->fd;
1873 			pfd.events = POLLIN | POLLERR;
1874 			poll(&pfd, 1, 0);
1875 		}
1876 	}
1877 
1878 	for (i = 0; i < num_events; i++) {
1879 #if defined(SPDK_EPOLL)
1880 		sock = events[i].data.ptr;
1881 		psock = __posix_sock(sock);
1882 
1883 #ifdef SPDK_ZEROCOPY
1884 		if (events[i].events & EPOLLERR) {
1885 			rc = _sock_check_zcopy(sock);
1886 			/* If the socket was closed or removed from
1887 			 * the group in response to a send ack, don't
1888 			 * add it to the array here. */
1889 			if (rc || sock->cb_fn == NULL) {
1890 				continue;
1891 			}
1892 		}
1893 #endif
1894 		if ((events[i].events & EPOLLIN) == 0) {
1895 			continue;
1896 		}
1897 
1898 #elif defined(SPDK_KEVENT)
1899 		sock = events[i].udata;
1900 		psock = __posix_sock(sock);
1901 #endif
1902 
1903 		/* If the socket is not already in the list, add it now */
1904 		if (!psock->socket_has_data && !psock->pipe_has_data) {
1905 			TAILQ_INSERT_TAIL(&group->socks_with_data, psock, link);
1906 		}
1907 		psock->socket_has_data = true;
1908 	}
1909 
1910 	num_events = 0;
1911 
1912 	TAILQ_FOREACH_SAFE(psock, &group->socks_with_data, link, ptmp) {
1913 		if (num_events == max_events) {
1914 			break;
1915 		}
1916 
1917 		/* If the socket's cb_fn is NULL, just remove it from the
1918 		 * list and do not add it to socks array */
1919 		if (spdk_unlikely(psock->base.cb_fn == NULL)) {
1920 			psock->socket_has_data = false;
1921 			psock->pipe_has_data = false;
1922 			TAILQ_REMOVE(&group->socks_with_data, psock, link);
1923 			continue;
1924 		}
1925 
1926 		socks[num_events++] = &psock->base;
1927 	}
1928 
1929 	/* Cycle the has_data list so that each time we poll things aren't
1930 	 * in the same order. Say we have 6 sockets in the list, named as follows:
1931 	 * A B C D E F
1932 	 * And all 6 sockets had epoll events, but max_events is only 3. That means
1933 	 * psock currently points at D. We want to rearrange the list to the following:
1934 	 * D E F A B C
1935 	 *
1936 	 * The variables below are named according to this example to make it easier to
1937 	 * follow the swaps.
1938 	 */
1939 	if (psock != NULL) {
1940 		struct spdk_posix_sock *pa, *pc, *pd, *pf;
1941 
1942 		/* Capture pointers to the elements we need */
1943 		pd = psock;
1944 		pc = TAILQ_PREV(pd, spdk_has_data_list, link);
1945 		pa = TAILQ_FIRST(&group->socks_with_data);
1946 		pf = TAILQ_LAST(&group->socks_with_data, spdk_has_data_list);
1947 
1948 		/* Break the link between C and D */
1949 		pc->link.tqe_next = NULL;
1950 
1951 		/* Connect F to A */
1952 		pf->link.tqe_next = pa;
1953 		pa->link.tqe_prev = &pf->link.tqe_next;
1954 
1955 		/* Fix up the list first/last pointers */
1956 		group->socks_with_data.tqh_first = pd;
1957 		group->socks_with_data.tqh_last = &pc->link.tqe_next;
1958 
1959 		/* D is in front of the list, make tqe prev pointer point to the head of list */
1960 		pd->link.tqe_prev = &group->socks_with_data.tqh_first;
1961 	}
1962 
1963 	return num_events;
1964 }
1965 
1966 static int
1967 posix_sock_group_impl_close(struct spdk_sock_group_impl *_group)
1968 {
1969 	struct spdk_posix_sock_group_impl *group = __posix_group_impl(_group);
1970 	int rc;
1971 
1972 	if (g_spdk_posix_sock_impl_opts.enable_placement_id == PLACEMENT_CPU) {
1973 		spdk_sock_map_release(&g_map, spdk_env_get_current_core());
1974 	}
1975 
1976 	rc = close(group->fd);
1977 	free(group);
1978 	return rc;
1979 }
1980 
1981 static struct spdk_net_impl g_posix_net_impl = {
1982 	.name		= "posix",
1983 	.getaddr	= posix_sock_getaddr,
1984 	.connect	= posix_sock_connect,
1985 	.listen		= posix_sock_listen,
1986 	.accept		= posix_sock_accept,
1987 	.close		= posix_sock_close,
1988 	.recv		= posix_sock_recv,
1989 	.readv		= posix_sock_readv,
1990 	.readv_async	= posix_sock_readv_async,
1991 	.writev		= posix_sock_writev,
1992 	.writev_async	= posix_sock_writev_async,
1993 	.flush		= posix_sock_flush,
1994 	.set_recvlowat	= posix_sock_set_recvlowat,
1995 	.set_recvbuf	= posix_sock_set_recvbuf,
1996 	.set_sendbuf	= posix_sock_set_sendbuf,
1997 	.is_ipv6	= posix_sock_is_ipv6,
1998 	.is_ipv4	= posix_sock_is_ipv4,
1999 	.is_connected	= posix_sock_is_connected,
2000 	.group_impl_get_optimal	= posix_sock_group_impl_get_optimal,
2001 	.group_impl_create	= posix_sock_group_impl_create,
2002 	.group_impl_add_sock	= posix_sock_group_impl_add_sock,
2003 	.group_impl_remove_sock = posix_sock_group_impl_remove_sock,
2004 	.group_impl_poll	= posix_sock_group_impl_poll,
2005 	.group_impl_close	= posix_sock_group_impl_close,
2006 	.get_opts	= posix_sock_impl_get_opts,
2007 	.set_opts	= posix_sock_impl_set_opts,
2008 };
2009 
2010 SPDK_NET_IMPL_REGISTER(posix, &g_posix_net_impl, DEFAULT_SOCK_PRIORITY + 1);
2011 
2012 static struct spdk_sock *
2013 ssl_sock_listen(const char *ip, int port, struct spdk_sock_opts *opts)
2014 {
2015 	return posix_sock_create(ip, port, SPDK_SOCK_CREATE_LISTEN, opts, true);
2016 }
2017 
2018 static struct spdk_sock *
2019 ssl_sock_connect(const char *ip, int port, struct spdk_sock_opts *opts)
2020 {
2021 	return posix_sock_create(ip, port, SPDK_SOCK_CREATE_CONNECT, opts, true);
2022 }
2023 
2024 static struct spdk_net_impl g_ssl_net_impl = {
2025 	.name		= "ssl",
2026 	.getaddr	= posix_sock_getaddr,
2027 	.connect	= ssl_sock_connect,
2028 	.listen		= ssl_sock_listen,
2029 	.accept		= posix_sock_accept,
2030 	.close		= posix_sock_close,
2031 	.recv		= posix_sock_recv,
2032 	.readv		= posix_sock_readv,
2033 	.writev		= posix_sock_writev,
2034 	.writev_async	= posix_sock_writev_async,
2035 	.flush		= posix_sock_flush,
2036 	.set_recvlowat	= posix_sock_set_recvlowat,
2037 	.set_recvbuf	= posix_sock_set_recvbuf,
2038 	.set_sendbuf	= posix_sock_set_sendbuf,
2039 	.is_ipv6	= posix_sock_is_ipv6,
2040 	.is_ipv4	= posix_sock_is_ipv4,
2041 	.is_connected	= posix_sock_is_connected,
2042 	.group_impl_get_optimal	= posix_sock_group_impl_get_optimal,
2043 	.group_impl_create	= posix_sock_group_impl_create,
2044 	.group_impl_add_sock	= posix_sock_group_impl_add_sock,
2045 	.group_impl_remove_sock = posix_sock_group_impl_remove_sock,
2046 	.group_impl_poll	= posix_sock_group_impl_poll,
2047 	.group_impl_close	= posix_sock_group_impl_close,
2048 	.get_opts	= posix_sock_impl_get_opts,
2049 	.set_opts	= posix_sock_impl_set_opts,
2050 };
2051 
2052 SPDK_NET_IMPL_REGISTER(ssl, &g_ssl_net_impl, DEFAULT_SOCK_PRIORITY);
2053 SPDK_LOG_REGISTER_COMPONENT(sock_posix)
2054