xref: /spdk/module/sock/posix/posix.c (revision f2dbb50516db0ce1bb06e37f77fef5b437e98c6a)
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 	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 = DEFAULT_SO_RCVBUF_SIZE,
73 	.send_buf_size = DEFAULT_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 	int rc;
259 
260 	if (sock->recv_buf_sz == sz) {
261 		return 0;
262 	}
263 
264 	/* If the new size is 0, just free the pipe */
265 	if (sz == 0) {
266 		spdk_pipe_destroy(sock->recv_pipe);
267 		free(sock->recv_buf);
268 		sock->recv_pipe = NULL;
269 		sock->recv_buf = NULL;
270 		return 0;
271 	} else if (sz < MIN_SOCK_PIPE_SIZE) {
272 		SPDK_ERRLOG("The size of the pipe must be larger than %d\n", MIN_SOCK_PIPE_SIZE);
273 		return -1;
274 	}
275 
276 	/* Round up to next 64 byte multiple */
277 	rc = posix_memalign((void **)&new_buf, 64, sz);
278 	if (rc != 0) {
279 		SPDK_ERRLOG("socket recv buf allocation failed\n");
280 		return -ENOMEM;
281 	}
282 	memset(new_buf, 0, sz);
283 
284 	new_pipe = spdk_pipe_create(new_buf, sz);
285 	if (new_pipe == NULL) {
286 		SPDK_ERRLOG("socket pipe allocation failed\n");
287 		free(new_buf);
288 		return -ENOMEM;
289 	}
290 
291 	if (sock->recv_pipe != NULL) {
292 		/* Pull all of the data out of the old pipe */
293 		sbytes = spdk_pipe_reader_get_buffer(sock->recv_pipe, sock->recv_buf_sz, siov);
294 		if (sbytes > sz) {
295 			/* Too much data to fit into the new pipe size */
296 			spdk_pipe_destroy(new_pipe);
297 			free(new_buf);
298 			return -EINVAL;
299 		}
300 
301 		sbytes = spdk_pipe_writer_get_buffer(new_pipe, sz, diov);
302 		assert(sbytes == sz);
303 
304 		bytes = spdk_iovcpy(siov, 2, diov, 2);
305 		spdk_pipe_writer_advance(new_pipe, bytes);
306 
307 		spdk_pipe_destroy(sock->recv_pipe);
308 		free(sock->recv_buf);
309 	}
310 
311 	sock->recv_buf_sz = sz;
312 	sock->recv_buf = new_buf;
313 	sock->recv_pipe = new_pipe;
314 
315 	return 0;
316 }
317 
318 static int
319 posix_sock_set_recvbuf(struct spdk_sock *_sock, int sz)
320 {
321 	struct spdk_posix_sock *sock = __posix_sock(_sock);
322 	int min_size;
323 	int rc;
324 
325 	assert(sock != NULL);
326 
327 	if (_sock->impl_opts.enable_recv_pipe) {
328 		rc = posix_sock_alloc_pipe(sock, sz);
329 		if (rc) {
330 			return rc;
331 		}
332 	}
333 
334 	/* Set kernel buffer size to be at least MIN_SO_RCVBUF_SIZE and
335 	 * g_spdk_posix_sock_impl_opts.recv_buf_size. */
336 	min_size = spdk_max(MIN_SO_RCVBUF_SIZE, g_spdk_posix_sock_impl_opts.recv_buf_size);
337 
338 	if (sz < min_size) {
339 		sz = min_size;
340 	}
341 
342 	rc = setsockopt(sock->fd, SOL_SOCKET, SO_RCVBUF, &sz, sizeof(sz));
343 	if (rc < 0) {
344 		return rc;
345 	}
346 
347 	_sock->impl_opts.recv_buf_size = sz;
348 
349 	return 0;
350 }
351 
352 static int
353 posix_sock_set_sendbuf(struct spdk_sock *_sock, int sz)
354 {
355 	struct spdk_posix_sock *sock = __posix_sock(_sock);
356 	int min_size;
357 	int rc;
358 
359 	assert(sock != NULL);
360 
361 	/* Set kernel buffer size to be at least MIN_SO_SNDBUF_SIZE and
362 	 * g_spdk_posix_sock_impl_opts.send_buf_size. */
363 	min_size = spdk_max(MIN_SO_SNDBUF_SIZE, g_spdk_posix_sock_impl_opts.send_buf_size);
364 
365 	if (sz < min_size) {
366 		sz = min_size;
367 	}
368 
369 	rc = setsockopt(sock->fd, SOL_SOCKET, SO_SNDBUF, &sz, sizeof(sz));
370 	if (rc < 0) {
371 		return rc;
372 	}
373 
374 	_sock->impl_opts.send_buf_size = sz;
375 
376 	return 0;
377 }
378 
379 static void
380 posix_sock_init(struct spdk_posix_sock *sock, bool enable_zero_copy)
381 {
382 #if defined(SPDK_ZEROCOPY) || defined(__linux__)
383 	int flag;
384 	int rc;
385 #endif
386 
387 #if defined(SPDK_ZEROCOPY)
388 	flag = 1;
389 
390 	if (enable_zero_copy) {
391 		/* Try to turn on zero copy sends */
392 		rc = setsockopt(sock->fd, SOL_SOCKET, SO_ZEROCOPY, &flag, sizeof(flag));
393 		if (rc == 0) {
394 			sock->zcopy = true;
395 		}
396 	}
397 #endif
398 
399 #if defined(__linux__)
400 	flag = 1;
401 
402 	if (sock->base.impl_opts.enable_quickack) {
403 		rc = setsockopt(sock->fd, IPPROTO_TCP, TCP_QUICKACK, &flag, sizeof(flag));
404 		if (rc != 0) {
405 			SPDK_ERRLOG("quickack was failed to set\n");
406 		}
407 	}
408 
409 	spdk_sock_get_placement_id(sock->fd, sock->base.impl_opts.enable_placement_id,
410 				   &sock->placement_id);
411 
412 	if (sock->base.impl_opts.enable_placement_id == PLACEMENT_MARK) {
413 		/* Save placement_id */
414 		spdk_sock_map_insert(&g_map, sock->placement_id, NULL);
415 	}
416 #endif
417 }
418 
419 static struct spdk_posix_sock *
420 posix_sock_alloc(int fd, struct spdk_sock_impl_opts *impl_opts, bool enable_zero_copy)
421 {
422 	struct spdk_posix_sock *sock;
423 
424 	sock = calloc(1, sizeof(*sock));
425 	if (sock == NULL) {
426 		SPDK_ERRLOG("sock allocation failed\n");
427 		return NULL;
428 	}
429 
430 	sock->fd = fd;
431 	memcpy(&sock->base.impl_opts, impl_opts, sizeof(*impl_opts));
432 	posix_sock_init(sock, enable_zero_copy);
433 
434 	return sock;
435 }
436 
437 static int
438 posix_fd_create(struct addrinfo *res, struct spdk_sock_opts *opts,
439 		struct spdk_sock_impl_opts *impl_opts)
440 {
441 	int fd;
442 	int val = 1;
443 	int rc, sz;
444 #if defined(__linux__)
445 	int to;
446 #endif
447 
448 	fd = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
449 	if (fd < 0) {
450 		/* error */
451 		return -1;
452 	}
453 
454 	sz = impl_opts->recv_buf_size;
455 	rc = setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &sz, sizeof(sz));
456 	if (rc) {
457 		/* Not fatal */
458 	}
459 
460 	sz = impl_opts->send_buf_size;
461 	rc = setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &sz, sizeof(sz));
462 	if (rc) {
463 		/* Not fatal */
464 	}
465 
466 	rc = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof val);
467 	if (rc != 0) {
468 		close(fd);
469 		/* error */
470 		return -1;
471 	}
472 	rc = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &val, sizeof val);
473 	if (rc != 0) {
474 		close(fd);
475 		/* error */
476 		return -1;
477 	}
478 
479 #if defined(SO_PRIORITY)
480 	if (opts->priority) {
481 		rc = setsockopt(fd, SOL_SOCKET, SO_PRIORITY, &opts->priority, sizeof val);
482 		if (rc != 0) {
483 			close(fd);
484 			/* error */
485 			return -1;
486 		}
487 	}
488 #endif
489 
490 	if (res->ai_family == AF_INET6) {
491 		rc = setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof val);
492 		if (rc != 0) {
493 			close(fd);
494 			/* error */
495 			return -1;
496 		}
497 	}
498 
499 	if (opts->ack_timeout) {
500 #if defined(__linux__)
501 		to = opts->ack_timeout;
502 		rc = setsockopt(fd, IPPROTO_TCP, TCP_USER_TIMEOUT, &to, sizeof(to));
503 		if (rc != 0) {
504 			close(fd);
505 			/* error */
506 			return -1;
507 		}
508 #else
509 		SPDK_WARNLOG("TCP_USER_TIMEOUT is not supported.\n");
510 #endif
511 	}
512 
513 	return fd;
514 }
515 
516 static unsigned int
517 posix_sock_tls_psk_server_cb(SSL *ssl,
518 			     const char *id,
519 			     unsigned char *psk,
520 			     unsigned int max_psk_len)
521 {
522 	long key_len;
523 	unsigned char *default_psk;
524 	struct spdk_sock_impl_opts *impl_opts;
525 
526 	impl_opts = SSL_get_app_data(ssl);
527 
528 	if (impl_opts->psk_key == NULL) {
529 		SPDK_ERRLOG("PSK is not set\n");
530 		goto err;
531 	}
532 	SPDK_DEBUGLOG(sock_posix, "Length of Client's PSK ID %lu\n", strlen(impl_opts->psk_identity));
533 	if (id == NULL) {
534 		SPDK_ERRLOG("Received empty PSK ID\n");
535 		goto err;
536 	}
537 	SPDK_DEBUGLOG(sock_posix,  "Received PSK ID '%s'\n", id);
538 	if (strcmp(impl_opts->psk_identity, id) != 0) {
539 		SPDK_ERRLOG("Unknown Client's PSK ID\n");
540 		goto err;
541 	}
542 
543 	SPDK_DEBUGLOG(sock_posix, "Length of Client's PSK KEY %u\n", max_psk_len);
544 	default_psk = OPENSSL_hexstr2buf(impl_opts->psk_key, &key_len);
545 	if (default_psk == NULL) {
546 		SPDK_ERRLOG("Could not unhexlify PSK\n");
547 		goto err;
548 	}
549 	if (key_len > max_psk_len) {
550 		SPDK_ERRLOG("Insufficient buffer size to copy PSK\n");
551 		OPENSSL_free(default_psk);
552 		goto err;
553 	}
554 
555 	memcpy(psk, default_psk, key_len);
556 	OPENSSL_free(default_psk);
557 
558 	return key_len;
559 
560 err:
561 	return 0;
562 }
563 
564 static unsigned int
565 posix_sock_tls_psk_client_cb(SSL *ssl, const char *hint,
566 			     char *identity,
567 			     unsigned int max_identity_len,
568 			     unsigned char *psk,
569 			     unsigned int max_psk_len)
570 {
571 	long key_len;
572 	unsigned char *default_psk;
573 	struct spdk_sock_impl_opts *impl_opts;
574 
575 	impl_opts = SSL_get_app_data(ssl);
576 
577 	if (hint) {
578 		SPDK_DEBUGLOG(sock_posix,  "Received PSK identity hint '%s'\n", hint);
579 	}
580 
581 	if (impl_opts->psk_key == NULL) {
582 		SPDK_ERRLOG("PSK is not set\n");
583 		goto err;
584 	}
585 	default_psk = OPENSSL_hexstr2buf(impl_opts->psk_key, &key_len);
586 	if (default_psk == NULL) {
587 		SPDK_ERRLOG("Could not unhexlify PSK\n");
588 		goto err;
589 	}
590 	if ((strlen(impl_opts->psk_identity) + 1 > max_identity_len)
591 	    || (key_len > max_psk_len)) {
592 		OPENSSL_free(default_psk);
593 		SPDK_ERRLOG("PSK ID or Key buffer is not sufficient\n");
594 		goto err;
595 	}
596 	spdk_strcpy_pad(identity, impl_opts->psk_identity, strlen(impl_opts->psk_identity), 0);
597 	SPDK_DEBUGLOG(sock_posix, "Sending PSK identity '%s'\n", identity);
598 
599 	memcpy(psk, default_psk, key_len);
600 	SPDK_DEBUGLOG(sock_posix, "Provided out-of-band (OOB) PSK for TLS1.3 client\n");
601 	OPENSSL_free(default_psk);
602 
603 	return key_len;
604 
605 err:
606 	return 0;
607 }
608 
609 static SSL_CTX *
610 posix_sock_create_ssl_context(const SSL_METHOD *method, struct spdk_sock_opts *opts,
611 			      struct spdk_sock_impl_opts *impl_opts)
612 {
613 	SSL_CTX *ctx;
614 	int tls_version = 0;
615 	bool ktls_enabled = false;
616 #ifdef SSL_OP_ENABLE_KTLS
617 	long options;
618 #endif
619 
620 	SSL_library_init();
621 	OpenSSL_add_all_algorithms();
622 	SSL_load_error_strings();
623 	/* Produce a SSL CTX in SSL V2 and V3 standards compliant way */
624 	ctx = SSL_CTX_new(method);
625 	if (!ctx) {
626 		SPDK_ERRLOG("SSL_CTX_new() failed, msg = %s\n", ERR_error_string(ERR_peek_last_error(), NULL));
627 		return NULL;
628 	}
629 	SPDK_DEBUGLOG(sock_posix, "SSL context created\n");
630 
631 	switch (impl_opts->tls_version) {
632 	case 0:
633 		/* auto-negotioation */
634 		break;
635 	case SPDK_TLS_VERSION_1_1:
636 		tls_version = TLS1_1_VERSION;
637 		break;
638 	case SPDK_TLS_VERSION_1_2:
639 		tls_version = TLS1_2_VERSION;
640 		break;
641 	case SPDK_TLS_VERSION_1_3:
642 		tls_version = TLS1_3_VERSION;
643 		break;
644 	default:
645 		SPDK_ERRLOG("Incorrect TLS version provided: %d\n", impl_opts->tls_version);
646 		goto err;
647 	}
648 
649 	if (tls_version) {
650 		SPDK_DEBUGLOG(sock_posix, "Hardening TLS version to '%d'='0x%X'\n", impl_opts->tls_version,
651 			      tls_version);
652 		if (!SSL_CTX_set_min_proto_version(ctx, tls_version)) {
653 			SPDK_ERRLOG("Unable to set Min TLS version to '%d'='0x%X\n", impl_opts->tls_version, tls_version);
654 			goto err;
655 		}
656 		if (!SSL_CTX_set_max_proto_version(ctx, tls_version)) {
657 			SPDK_ERRLOG("Unable to set Max TLS version to '%d'='0x%X\n", impl_opts->tls_version, tls_version);
658 			goto err;
659 		}
660 	}
661 	if (impl_opts->enable_ktls) {
662 		SPDK_DEBUGLOG(sock_posix, "Enabling kTLS offload\n");
663 #ifdef SSL_OP_ENABLE_KTLS
664 		options = SSL_CTX_set_options(ctx, SSL_OP_ENABLE_KTLS);
665 		ktls_enabled = options & SSL_OP_ENABLE_KTLS;
666 #else
667 		ktls_enabled = false;
668 #endif
669 		if (!ktls_enabled) {
670 			SPDK_ERRLOG("Unable to set kTLS offload via SSL_CTX_set_options(). Configure openssl with 'enable-ktls'\n");
671 			goto err;
672 		}
673 	}
674 
675 	return ctx;
676 
677 err:
678 	SSL_CTX_free(ctx);
679 	return NULL;
680 }
681 
682 static SSL *
683 ssl_sock_connect_loop(SSL_CTX *ctx, int fd, struct spdk_sock_impl_opts *impl_opts)
684 {
685 	int rc;
686 	SSL *ssl;
687 	int ssl_get_error;
688 
689 	ssl = SSL_new(ctx);
690 	if (!ssl) {
691 		SPDK_ERRLOG("SSL_new() failed, msg = %s\n", ERR_error_string(ERR_peek_last_error(), NULL));
692 		return NULL;
693 	}
694 	SSL_set_fd(ssl, fd);
695 	SSL_set_app_data(ssl, impl_opts);
696 	SSL_set_psk_client_callback(ssl, posix_sock_tls_psk_client_cb);
697 	SPDK_DEBUGLOG(sock_posix, "SSL object creation finished: %p\n", ssl);
698 	SPDK_DEBUGLOG(sock_posix, "%s = SSL_state_string_long(%p)\n", SSL_state_string_long(ssl), ssl);
699 	while ((rc = SSL_connect(ssl)) != 1) {
700 		SPDK_DEBUGLOG(sock_posix, "%s = SSL_state_string_long(%p)\n", SSL_state_string_long(ssl), ssl);
701 		ssl_get_error = SSL_get_error(ssl, rc);
702 		SPDK_DEBUGLOG(sock_posix, "SSL_connect failed %d = SSL_connect(%p), %d = SSL_get_error(%p, %d)\n",
703 			      rc, ssl, ssl_get_error, ssl, rc);
704 		switch (ssl_get_error) {
705 		case SSL_ERROR_WANT_READ:
706 		case SSL_ERROR_WANT_WRITE:
707 			continue;
708 		default:
709 			break;
710 		}
711 		SPDK_ERRLOG("SSL_connect() failed, errno = %d\n", errno);
712 		SSL_free(ssl);
713 		return NULL;
714 	}
715 	SPDK_DEBUGLOG(sock_posix, "%s = SSL_state_string_long(%p)\n", SSL_state_string_long(ssl), ssl);
716 	SPDK_DEBUGLOG(sock_posix, "Negotiated Cipher suite:%s\n",
717 		      SSL_CIPHER_get_name(SSL_get_current_cipher(ssl)));
718 	return ssl;
719 }
720 
721 static SSL *
722 ssl_sock_accept_loop(SSL_CTX *ctx, int fd, struct spdk_sock_impl_opts *impl_opts)
723 {
724 	int rc;
725 	SSL *ssl;
726 	int ssl_get_error;
727 
728 	ssl = SSL_new(ctx);
729 	if (!ssl) {
730 		SPDK_ERRLOG("SSL_new() failed, msg = %s\n", ERR_error_string(ERR_peek_last_error(), NULL));
731 		return NULL;
732 	}
733 	SSL_set_fd(ssl, fd);
734 	SSL_set_app_data(ssl, impl_opts);
735 	SSL_set_psk_server_callback(ssl, posix_sock_tls_psk_server_cb);
736 	SPDK_DEBUGLOG(sock_posix, "SSL object creation finished: %p\n", ssl);
737 	SPDK_DEBUGLOG(sock_posix, "%s = SSL_state_string_long(%p)\n", SSL_state_string_long(ssl), ssl);
738 	while ((rc = SSL_accept(ssl)) != 1) {
739 		SPDK_DEBUGLOG(sock_posix, "%s = SSL_state_string_long(%p)\n", SSL_state_string_long(ssl), ssl);
740 		ssl_get_error = SSL_get_error(ssl, rc);
741 		SPDK_DEBUGLOG(sock_posix, "SSL_accept failed %d = SSL_accept(%p), %d = SSL_get_error(%p, %d)\n", rc,
742 			      ssl, ssl_get_error, ssl, rc);
743 		switch (ssl_get_error) {
744 		case SSL_ERROR_WANT_READ:
745 		case SSL_ERROR_WANT_WRITE:
746 			continue;
747 		default:
748 			break;
749 		}
750 		SPDK_ERRLOG("SSL_accept() failed, errno = %d\n", errno);
751 		SSL_free(ssl);
752 		return NULL;
753 	}
754 	SPDK_DEBUGLOG(sock_posix, "%s = SSL_state_string_long(%p)\n", SSL_state_string_long(ssl), ssl);
755 	SPDK_DEBUGLOG(sock_posix, "Negotiated Cipher suite:%s\n",
756 		      SSL_CIPHER_get_name(SSL_get_current_cipher(ssl)));
757 	return ssl;
758 }
759 
760 static ssize_t
761 SSL_readv(SSL *ssl, const struct iovec *iov, int iovcnt)
762 {
763 	int i, rc = 0;
764 	ssize_t total = 0;
765 
766 	for (i = 0; i < iovcnt; i++) {
767 		rc = SSL_read(ssl, iov[i].iov_base, iov[i].iov_len);
768 
769 		if (rc > 0) {
770 			total += rc;
771 		}
772 		if (rc != (int)iov[i].iov_len) {
773 			break;
774 		}
775 	}
776 	if (total > 0) {
777 		errno = 0;
778 		return total;
779 	}
780 	switch (SSL_get_error(ssl, rc)) {
781 	case SSL_ERROR_ZERO_RETURN:
782 		errno = ENOTCONN;
783 		return 0;
784 	case SSL_ERROR_WANT_READ:
785 	case SSL_ERROR_WANT_WRITE:
786 	case SSL_ERROR_WANT_CONNECT:
787 	case SSL_ERROR_WANT_ACCEPT:
788 	case SSL_ERROR_WANT_X509_LOOKUP:
789 	case SSL_ERROR_WANT_ASYNC:
790 	case SSL_ERROR_WANT_ASYNC_JOB:
791 	case SSL_ERROR_WANT_CLIENT_HELLO_CB:
792 		errno = EAGAIN;
793 		return -1;
794 	case SSL_ERROR_SYSCALL:
795 	case SSL_ERROR_SSL:
796 		errno = ENOTCONN;
797 		return -1;
798 	default:
799 		errno = ENOTCONN;
800 		return -1;
801 	}
802 }
803 
804 static ssize_t
805 SSL_writev(SSL *ssl, struct iovec *iov, int iovcnt)
806 {
807 	int i, rc = 0;
808 	ssize_t total = 0;
809 
810 	for (i = 0; i < iovcnt; i++) {
811 		rc = SSL_write(ssl, iov[i].iov_base, iov[i].iov_len);
812 
813 		if (rc > 0) {
814 			total += rc;
815 		}
816 		if (rc != (int)iov[i].iov_len) {
817 			break;
818 		}
819 	}
820 	if (total > 0) {
821 		errno = 0;
822 		return total;
823 	}
824 	switch (SSL_get_error(ssl, rc)) {
825 	case SSL_ERROR_ZERO_RETURN:
826 		errno = ENOTCONN;
827 		return 0;
828 	case SSL_ERROR_WANT_READ:
829 	case SSL_ERROR_WANT_WRITE:
830 	case SSL_ERROR_WANT_CONNECT:
831 	case SSL_ERROR_WANT_ACCEPT:
832 	case SSL_ERROR_WANT_X509_LOOKUP:
833 	case SSL_ERROR_WANT_ASYNC:
834 	case SSL_ERROR_WANT_ASYNC_JOB:
835 	case SSL_ERROR_WANT_CLIENT_HELLO_CB:
836 		errno = EAGAIN;
837 		return -1;
838 	case SSL_ERROR_SYSCALL:
839 	case SSL_ERROR_SSL:
840 		errno = ENOTCONN;
841 		return -1;
842 	default:
843 		errno = ENOTCONN;
844 		return -1;
845 	}
846 }
847 
848 static struct spdk_sock *
849 posix_sock_create(const char *ip, int port,
850 		  enum posix_sock_create_type type,
851 		  struct spdk_sock_opts *opts,
852 		  bool enable_ssl)
853 {
854 	struct spdk_posix_sock *sock;
855 	struct spdk_sock_impl_opts impl_opts;
856 	char buf[MAX_TMPBUF];
857 	char portnum[PORTNUMLEN];
858 	char *p;
859 	struct addrinfo hints, *res, *res0;
860 	int fd, flag;
861 	int rc;
862 	bool enable_zcopy_user_opts = true;
863 	bool enable_zcopy_impl_opts = true;
864 	SSL_CTX *ctx = 0;
865 	SSL *ssl = 0;
866 
867 	assert(opts != NULL);
868 	posix_opts_get_impl_opts(opts, &impl_opts);
869 
870 	if (ip == NULL) {
871 		return NULL;
872 	}
873 	if (ip[0] == '[') {
874 		snprintf(buf, sizeof(buf), "%s", ip + 1);
875 		p = strchr(buf, ']');
876 		if (p != NULL) {
877 			*p = '\0';
878 		}
879 		ip = (const char *) &buf[0];
880 	}
881 
882 	snprintf(portnum, sizeof portnum, "%d", port);
883 	memset(&hints, 0, sizeof hints);
884 	hints.ai_family = PF_UNSPEC;
885 	hints.ai_socktype = SOCK_STREAM;
886 	hints.ai_flags = AI_NUMERICSERV;
887 	hints.ai_flags |= AI_PASSIVE;
888 	hints.ai_flags |= AI_NUMERICHOST;
889 	rc = getaddrinfo(ip, portnum, &hints, &res0);
890 	if (rc != 0) {
891 		SPDK_ERRLOG("getaddrinfo() failed %s (%d)\n", gai_strerror(rc), rc);
892 		return NULL;
893 	}
894 
895 	/* try listen */
896 	fd = -1;
897 	for (res = res0; res != NULL; res = res->ai_next) {
898 retry:
899 		fd = posix_fd_create(res, opts, &impl_opts);
900 		if (fd < 0) {
901 			continue;
902 		}
903 		if (type == SPDK_SOCK_CREATE_LISTEN) {
904 			rc = bind(fd, res->ai_addr, res->ai_addrlen);
905 			if (rc != 0) {
906 				SPDK_ERRLOG("bind() failed at port %d, errno = %d\n", port, errno);
907 				switch (errno) {
908 				case EINTR:
909 					/* interrupted? */
910 					close(fd);
911 					goto retry;
912 				case EADDRNOTAVAIL:
913 					SPDK_ERRLOG("IP address %s not available. "
914 						    "Verify IP address in config file "
915 						    "and make sure setup script is "
916 						    "run before starting spdk app.\n", ip);
917 				/* FALLTHROUGH */
918 				default:
919 					/* try next family */
920 					close(fd);
921 					fd = -1;
922 					continue;
923 				}
924 			}
925 			/* bind OK */
926 			rc = listen(fd, 512);
927 			if (rc != 0) {
928 				SPDK_ERRLOG("listen() failed, errno = %d\n", errno);
929 				close(fd);
930 				fd = -1;
931 				break;
932 			}
933 			enable_zcopy_impl_opts = impl_opts.enable_zerocopy_send_server;
934 		} else if (type == SPDK_SOCK_CREATE_CONNECT) {
935 			rc = connect(fd, res->ai_addr, res->ai_addrlen);
936 			if (rc != 0) {
937 				SPDK_ERRLOG("connect() failed, errno = %d\n", errno);
938 				/* try next family */
939 				close(fd);
940 				fd = -1;
941 				continue;
942 			}
943 			enable_zcopy_impl_opts = impl_opts.enable_zerocopy_send_client;
944 			if (enable_ssl) {
945 				ctx = posix_sock_create_ssl_context(TLS_client_method(), opts, &impl_opts);
946 				if (!ctx) {
947 					SPDK_ERRLOG("posix_sock_create_ssl_context() failed, errno = %d\n", errno);
948 					close(fd);
949 					fd = -1;
950 					break;
951 				}
952 				ssl = ssl_sock_connect_loop(ctx, fd, &impl_opts);
953 				if (!ssl) {
954 					SPDK_ERRLOG("ssl_sock_connect_loop() failed, errno = %d\n", errno);
955 					close(fd);
956 					fd = -1;
957 					SSL_CTX_free(ctx);
958 					break;
959 				}
960 			}
961 		}
962 
963 		flag = fcntl(fd, F_GETFL);
964 		if (fcntl(fd, F_SETFL, flag | O_NONBLOCK) < 0) {
965 			SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%d)\n", fd, errno);
966 			SSL_free(ssl);
967 			SSL_CTX_free(ctx);
968 			close(fd);
969 			fd = -1;
970 			break;
971 		}
972 		break;
973 	}
974 	freeaddrinfo(res0);
975 
976 	if (fd < 0) {
977 		return NULL;
978 	}
979 
980 	/* Only enable zero copy for non-loopback and non-ssl sockets. */
981 	enable_zcopy_user_opts = opts->zcopy && !sock_is_loopback(fd) && !enable_ssl;
982 
983 	sock = posix_sock_alloc(fd, &impl_opts, enable_zcopy_user_opts && enable_zcopy_impl_opts);
984 	if (sock == NULL) {
985 		SPDK_ERRLOG("sock allocation failed\n");
986 		SSL_free(ssl);
987 		SSL_CTX_free(ctx);
988 		close(fd);
989 		return NULL;
990 	}
991 
992 	if (ctx) {
993 		sock->ctx = ctx;
994 	}
995 
996 	if (ssl) {
997 		sock->ssl = ssl;
998 	}
999 
1000 	return &sock->base;
1001 }
1002 
1003 static struct spdk_sock *
1004 posix_sock_listen(const char *ip, int port, struct spdk_sock_opts *opts)
1005 {
1006 	return posix_sock_create(ip, port, SPDK_SOCK_CREATE_LISTEN, opts, false);
1007 }
1008 
1009 static struct spdk_sock *
1010 posix_sock_connect(const char *ip, int port, struct spdk_sock_opts *opts)
1011 {
1012 	return posix_sock_create(ip, port, SPDK_SOCK_CREATE_CONNECT, opts, false);
1013 }
1014 
1015 static struct spdk_sock *
1016 _posix_sock_accept(struct spdk_sock *_sock, bool enable_ssl)
1017 {
1018 	struct spdk_posix_sock		*sock = __posix_sock(_sock);
1019 	struct sockaddr_storage		sa;
1020 	socklen_t			salen;
1021 	int				rc, fd;
1022 	struct spdk_posix_sock		*new_sock;
1023 	int				flag;
1024 	SSL_CTX *ctx = 0;
1025 	SSL *ssl = 0;
1026 
1027 	memset(&sa, 0, sizeof(sa));
1028 	salen = sizeof(sa);
1029 
1030 	assert(sock != NULL);
1031 
1032 	rc = accept(sock->fd, (struct sockaddr *)&sa, &salen);
1033 
1034 	if (rc == -1) {
1035 		return NULL;
1036 	}
1037 
1038 	fd = rc;
1039 
1040 	flag = fcntl(fd, F_GETFL);
1041 	if ((!(flag & O_NONBLOCK)) && (fcntl(fd, F_SETFL, flag | O_NONBLOCK) < 0)) {
1042 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%d)\n", fd, errno);
1043 		close(fd);
1044 		return NULL;
1045 	}
1046 
1047 #if defined(SO_PRIORITY)
1048 	/* The priority is not inherited, so call this function again */
1049 	if (sock->base.opts.priority) {
1050 		rc = setsockopt(fd, SOL_SOCKET, SO_PRIORITY, &sock->base.opts.priority, sizeof(int));
1051 		if (rc != 0) {
1052 			close(fd);
1053 			return NULL;
1054 		}
1055 	}
1056 #endif
1057 
1058 	/* Establish SSL connection */
1059 	if (enable_ssl) {
1060 		ctx = posix_sock_create_ssl_context(TLS_server_method(), &sock->base.opts, &sock->base.impl_opts);
1061 		if (!ctx) {
1062 			SPDK_ERRLOG("posix_sock_create_ssl_context() failed, errno = %d\n", errno);
1063 			close(fd);
1064 			return NULL;
1065 		}
1066 		ssl = ssl_sock_accept_loop(ctx, fd, &sock->base.impl_opts);
1067 		if (!ssl) {
1068 			SPDK_ERRLOG("ssl_sock_accept_loop() failed, errno = %d\n", errno);
1069 			close(fd);
1070 			SSL_CTX_free(ctx);
1071 			return NULL;
1072 		}
1073 	}
1074 
1075 	/* Inherit the zero copy feature from the listen socket */
1076 	new_sock = posix_sock_alloc(fd, &sock->base.impl_opts, sock->zcopy);
1077 	if (new_sock == NULL) {
1078 		close(fd);
1079 		SSL_free(ssl);
1080 		SSL_CTX_free(ctx);
1081 		return NULL;
1082 	}
1083 
1084 	if (ctx) {
1085 		new_sock->ctx = ctx;
1086 	}
1087 
1088 	if (ssl) {
1089 		new_sock->ssl = ssl;
1090 	}
1091 
1092 	return &new_sock->base;
1093 }
1094 
1095 static struct spdk_sock *
1096 posix_sock_accept(struct spdk_sock *_sock)
1097 {
1098 	return _posix_sock_accept(_sock, false);
1099 }
1100 
1101 static int
1102 posix_sock_close(struct spdk_sock *_sock)
1103 {
1104 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1105 
1106 	assert(TAILQ_EMPTY(&_sock->pending_reqs));
1107 
1108 	if (sock->ssl != NULL) {
1109 		SSL_shutdown(sock->ssl);
1110 	}
1111 
1112 	/* If the socket fails to close, the best choice is to
1113 	 * leak the fd but continue to free the rest of the sock
1114 	 * memory. */
1115 	close(sock->fd);
1116 
1117 	SSL_free(sock->ssl);
1118 	SSL_CTX_free(sock->ctx);
1119 
1120 	spdk_pipe_destroy(sock->recv_pipe);
1121 	free(sock->recv_buf);
1122 	free(sock);
1123 
1124 	return 0;
1125 }
1126 
1127 #ifdef SPDK_ZEROCOPY
1128 static int
1129 _sock_check_zcopy(struct spdk_sock *sock)
1130 {
1131 	struct spdk_posix_sock *psock = __posix_sock(sock);
1132 	struct msghdr msgh = {};
1133 	uint8_t buf[sizeof(struct cmsghdr) + sizeof(struct sock_extended_err)];
1134 	ssize_t rc;
1135 	struct sock_extended_err *serr;
1136 	struct cmsghdr *cm;
1137 	uint32_t idx;
1138 	struct spdk_sock_request *req, *treq;
1139 	bool found;
1140 
1141 	msgh.msg_control = buf;
1142 	msgh.msg_controllen = sizeof(buf);
1143 
1144 	while (true) {
1145 		rc = recvmsg(psock->fd, &msgh, MSG_ERRQUEUE);
1146 
1147 		if (rc < 0) {
1148 			if (errno == EWOULDBLOCK || errno == EAGAIN) {
1149 				return 0;
1150 			}
1151 
1152 			if (!TAILQ_EMPTY(&sock->pending_reqs)) {
1153 				SPDK_ERRLOG("Attempting to receive from ERRQUEUE yielded error, but pending list still has orphaned entries\n");
1154 			} else {
1155 				SPDK_WARNLOG("Recvmsg yielded an error!\n");
1156 			}
1157 			return 0;
1158 		}
1159 
1160 		cm = CMSG_FIRSTHDR(&msgh);
1161 		if (!(cm &&
1162 		      ((cm->cmsg_level == SOL_IP && cm->cmsg_type == IP_RECVERR) ||
1163 		       (cm->cmsg_level == SOL_IPV6 && cm->cmsg_type == IPV6_RECVERR)))) {
1164 			SPDK_WARNLOG("Unexpected cmsg level or type!\n");
1165 			return 0;
1166 		}
1167 
1168 		serr = (struct sock_extended_err *)CMSG_DATA(cm);
1169 		if (serr->ee_errno != 0 || serr->ee_origin != SO_EE_ORIGIN_ZEROCOPY) {
1170 			SPDK_WARNLOG("Unexpected extended error origin\n");
1171 			return 0;
1172 		}
1173 
1174 		/* Most of the time, the pending_reqs array is in the exact
1175 		 * order we need such that all of the requests to complete are
1176 		 * in order, in the front. It is guaranteed that all requests
1177 		 * belonging to the same sendmsg call are sequential, so once
1178 		 * we encounter one match we can stop looping as soon as a
1179 		 * non-match is found.
1180 		 */
1181 		idx = serr->ee_info;
1182 		while (true) {
1183 			found = false;
1184 			TAILQ_FOREACH_SAFE(req, &sock->pending_reqs, internal.link, treq) {
1185 				if (!req->internal.is_zcopy) {
1186 					/* This wasn't a zcopy request. It was just waiting in line to complete */
1187 					rc = spdk_sock_request_put(sock, req, 0);
1188 					if (rc < 0) {
1189 						return rc;
1190 					}
1191 				} else if (req->internal.offset == idx) {
1192 					found = true;
1193 					rc = spdk_sock_request_put(sock, req, 0);
1194 					if (rc < 0) {
1195 						return rc;
1196 					}
1197 				} else if (found) {
1198 					break;
1199 				}
1200 			}
1201 
1202 			if (idx == serr->ee_data) {
1203 				break;
1204 			}
1205 
1206 			if (idx == UINT32_MAX) {
1207 				idx = 0;
1208 			} else {
1209 				idx++;
1210 			}
1211 		}
1212 	}
1213 
1214 	return 0;
1215 }
1216 #endif
1217 
1218 static int
1219 _sock_flush(struct spdk_sock *sock)
1220 {
1221 	struct spdk_posix_sock *psock = __posix_sock(sock);
1222 	struct msghdr msg = {};
1223 	int flags;
1224 	struct iovec iovs[IOV_BATCH_SIZE];
1225 	int iovcnt;
1226 	int retval;
1227 	struct spdk_sock_request *req;
1228 	int i;
1229 	ssize_t rc, sent;
1230 	unsigned int offset;
1231 	size_t len;
1232 	bool is_zcopy = false;
1233 
1234 	/* Can't flush from within a callback or we end up with recursive calls */
1235 	if (sock->cb_cnt > 0) {
1236 		errno = EAGAIN;
1237 		return -1;
1238 	}
1239 
1240 #ifdef SPDK_ZEROCOPY
1241 	if (psock->zcopy) {
1242 		flags = MSG_ZEROCOPY | MSG_NOSIGNAL;
1243 	} else
1244 #endif
1245 	{
1246 		flags = MSG_NOSIGNAL;
1247 	}
1248 
1249 	iovcnt = spdk_sock_prep_reqs(sock, iovs, 0, NULL, &flags);
1250 	if (iovcnt == 0) {
1251 		return 0;
1252 	}
1253 
1254 #ifdef SPDK_ZEROCOPY
1255 	is_zcopy = flags & MSG_ZEROCOPY;
1256 #endif
1257 
1258 	/* Perform the vectored write */
1259 	msg.msg_iov = iovs;
1260 	msg.msg_iovlen = iovcnt;
1261 
1262 	if (psock->ssl) {
1263 		rc = SSL_writev(psock->ssl, iovs, iovcnt);
1264 	} else {
1265 		rc = sendmsg(psock->fd, &msg, flags);
1266 	}
1267 	if (rc <= 0) {
1268 		if (rc == 0 || errno == EAGAIN || errno == EWOULDBLOCK || (errno == ENOBUFS && psock->zcopy)) {
1269 			errno = EAGAIN;
1270 		}
1271 		return -1;
1272 	}
1273 
1274 	sent = rc;
1275 
1276 	if (is_zcopy) {
1277 		/* Handling overflow case, because we use psock->sendmsg_idx - 1 for the
1278 		 * req->internal.offset, so sendmsg_idx should not be zero  */
1279 		if (spdk_unlikely(psock->sendmsg_idx == UINT32_MAX)) {
1280 			psock->sendmsg_idx = 1;
1281 		} else {
1282 			psock->sendmsg_idx++;
1283 		}
1284 	}
1285 
1286 	/* Consume the requests that were actually written */
1287 	req = TAILQ_FIRST(&sock->queued_reqs);
1288 	while (req) {
1289 		offset = req->internal.offset;
1290 
1291 		/* req->internal.is_zcopy is true when the whole req or part of it is sent with zerocopy */
1292 		req->internal.is_zcopy = is_zcopy;
1293 
1294 		for (i = 0; i < req->iovcnt; i++) {
1295 			/* Advance by the offset first */
1296 			if (offset >= SPDK_SOCK_REQUEST_IOV(req, i)->iov_len) {
1297 				offset -= SPDK_SOCK_REQUEST_IOV(req, i)->iov_len;
1298 				continue;
1299 			}
1300 
1301 			/* Calculate the remaining length of this element */
1302 			len = SPDK_SOCK_REQUEST_IOV(req, i)->iov_len - offset;
1303 
1304 			if (len > (size_t)rc) {
1305 				/* This element was partially sent. */
1306 				req->internal.offset += rc;
1307 				return sent;
1308 			}
1309 
1310 			offset = 0;
1311 			req->internal.offset += len;
1312 			rc -= len;
1313 		}
1314 
1315 		/* Handled a full request. */
1316 		spdk_sock_request_pend(sock, req);
1317 
1318 		if (!req->internal.is_zcopy && req == TAILQ_FIRST(&sock->pending_reqs)) {
1319 			/* The sendmsg syscall above isn't currently asynchronous,
1320 			* so it's already done. */
1321 			retval = spdk_sock_request_put(sock, req, 0);
1322 			if (retval) {
1323 				break;
1324 			}
1325 		} else {
1326 			/* Re-use the offset field to hold the sendmsg call index. The
1327 			 * index is 0 based, so subtract one here because we've already
1328 			 * incremented above. */
1329 			req->internal.offset = psock->sendmsg_idx - 1;
1330 		}
1331 
1332 		if (rc == 0) {
1333 			break;
1334 		}
1335 
1336 		req = TAILQ_FIRST(&sock->queued_reqs);
1337 	}
1338 
1339 	return sent;
1340 }
1341 
1342 static int
1343 posix_sock_flush(struct spdk_sock *sock)
1344 {
1345 #ifdef SPDK_ZEROCOPY
1346 	struct spdk_posix_sock *psock = __posix_sock(sock);
1347 
1348 	if (psock->zcopy && !TAILQ_EMPTY(&sock->pending_reqs)) {
1349 		_sock_check_zcopy(sock);
1350 	}
1351 #endif
1352 
1353 	return _sock_flush(sock);
1354 }
1355 
1356 static ssize_t
1357 posix_sock_recv_from_pipe(struct spdk_posix_sock *sock, struct iovec *diov, int diovcnt)
1358 {
1359 	struct iovec siov[2];
1360 	int sbytes;
1361 	ssize_t bytes;
1362 	struct spdk_posix_sock_group_impl *group;
1363 
1364 	sbytes = spdk_pipe_reader_get_buffer(sock->recv_pipe, sock->recv_buf_sz, siov);
1365 	if (sbytes < 0) {
1366 		errno = EINVAL;
1367 		return -1;
1368 	} else if (sbytes == 0) {
1369 		errno = EAGAIN;
1370 		return -1;
1371 	}
1372 
1373 	bytes = spdk_iovcpy(siov, 2, diov, diovcnt);
1374 
1375 	if (bytes == 0) {
1376 		/* The only way this happens is if diov is 0 length */
1377 		errno = EINVAL;
1378 		return -1;
1379 	}
1380 
1381 	spdk_pipe_reader_advance(sock->recv_pipe, bytes);
1382 
1383 	/* If we drained the pipe, mark it appropriately */
1384 	if (spdk_pipe_reader_bytes_available(sock->recv_pipe) == 0) {
1385 		assert(sock->pipe_has_data == true);
1386 
1387 		group = __posix_group_impl(sock->base.group_impl);
1388 		if (group && !sock->socket_has_data) {
1389 			TAILQ_REMOVE(&group->socks_with_data, sock, link);
1390 		}
1391 
1392 		sock->pipe_has_data = false;
1393 	}
1394 
1395 	return bytes;
1396 }
1397 
1398 static inline ssize_t
1399 posix_sock_read(struct spdk_posix_sock *sock)
1400 {
1401 	struct iovec iov[2];
1402 	int bytes_avail, bytes_recvd;
1403 	struct spdk_posix_sock_group_impl *group;
1404 
1405 	bytes_avail = spdk_pipe_writer_get_buffer(sock->recv_pipe, sock->recv_buf_sz, iov);
1406 
1407 	if (bytes_avail <= 0) {
1408 		return bytes_avail;
1409 	}
1410 
1411 	if (sock->ssl) {
1412 		bytes_recvd = SSL_readv(sock->ssl, iov, 2);
1413 	} else {
1414 		bytes_recvd = readv(sock->fd, iov, 2);
1415 	}
1416 
1417 	assert(sock->pipe_has_data == false);
1418 
1419 	if (bytes_recvd <= 0) {
1420 		/* Errors count as draining the socket data */
1421 		if (sock->base.group_impl && sock->socket_has_data) {
1422 			group = __posix_group_impl(sock->base.group_impl);
1423 			TAILQ_REMOVE(&group->socks_with_data, sock, link);
1424 		}
1425 
1426 		sock->socket_has_data = false;
1427 
1428 		return bytes_recvd;
1429 	}
1430 
1431 	spdk_pipe_writer_advance(sock->recv_pipe, bytes_recvd);
1432 
1433 #if DEBUG
1434 	if (sock->base.group_impl) {
1435 		assert(sock->socket_has_data == true);
1436 	}
1437 #endif
1438 
1439 	sock->pipe_has_data = true;
1440 	if (bytes_recvd < bytes_avail) {
1441 		/* We drained the kernel socket entirely. */
1442 		sock->socket_has_data = false;
1443 	}
1444 
1445 	return bytes_recvd;
1446 }
1447 
1448 static ssize_t
1449 posix_sock_readv(struct spdk_sock *_sock, struct iovec *iov, int iovcnt)
1450 {
1451 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1452 	struct spdk_posix_sock_group_impl *group = __posix_group_impl(sock->base.group_impl);
1453 	int rc, i;
1454 	size_t len;
1455 
1456 	if (sock->recv_pipe == NULL) {
1457 		assert(sock->pipe_has_data == false);
1458 		if (group && sock->socket_has_data) {
1459 			sock->socket_has_data = false;
1460 			TAILQ_REMOVE(&group->socks_with_data, sock, link);
1461 		}
1462 		if (sock->ssl) {
1463 			return SSL_readv(sock->ssl, iov, iovcnt);
1464 		} else {
1465 			return readv(sock->fd, iov, iovcnt);
1466 		}
1467 	}
1468 
1469 	/* If the socket is not in a group, we must assume it always has
1470 	 * data waiting for us because it is not epolled */
1471 	if (!sock->pipe_has_data && (group == NULL || sock->socket_has_data)) {
1472 		/* If the user is receiving a sufficiently large amount of data,
1473 		 * receive directly to their buffers. */
1474 		len = 0;
1475 		for (i = 0; i < iovcnt; i++) {
1476 			len += iov[i].iov_len;
1477 		}
1478 
1479 		if (len >= MIN_SOCK_PIPE_SIZE) {
1480 			/* TODO: Should this detect if kernel socket is drained? */
1481 			if (sock->ssl) {
1482 				return SSL_readv(sock->ssl, iov, iovcnt);
1483 			} else {
1484 				return readv(sock->fd, iov, iovcnt);
1485 			}
1486 		}
1487 
1488 		/* Otherwise, do a big read into our pipe */
1489 		rc = posix_sock_read(sock);
1490 		if (rc <= 0) {
1491 			return rc;
1492 		}
1493 	}
1494 
1495 	return posix_sock_recv_from_pipe(sock, iov, iovcnt);
1496 }
1497 
1498 static ssize_t
1499 posix_sock_recv(struct spdk_sock *sock, void *buf, size_t len)
1500 {
1501 	struct iovec iov[1];
1502 
1503 	iov[0].iov_base = buf;
1504 	iov[0].iov_len = len;
1505 
1506 	return posix_sock_readv(sock, iov, 1);
1507 }
1508 
1509 static void
1510 posix_sock_readv_async(struct spdk_sock *sock, struct spdk_sock_request *req)
1511 {
1512 	req->cb_fn(req->cb_arg, -ENOTSUP);
1513 }
1514 
1515 static ssize_t
1516 posix_sock_writev(struct spdk_sock *_sock, struct iovec *iov, int iovcnt)
1517 {
1518 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1519 	int rc;
1520 
1521 	/* In order to process a writev, we need to flush any asynchronous writes
1522 	 * first. */
1523 	rc = _sock_flush(_sock);
1524 	if (rc < 0) {
1525 		return rc;
1526 	}
1527 
1528 	if (!TAILQ_EMPTY(&_sock->queued_reqs)) {
1529 		/* We weren't able to flush all requests */
1530 		errno = EAGAIN;
1531 		return -1;
1532 	}
1533 
1534 	if (sock->ssl) {
1535 		return SSL_writev(sock->ssl, iov, iovcnt);
1536 	} else {
1537 		return writev(sock->fd, iov, iovcnt);
1538 	}
1539 }
1540 
1541 static void
1542 posix_sock_writev_async(struct spdk_sock *sock, struct spdk_sock_request *req)
1543 {
1544 	int rc;
1545 
1546 	spdk_sock_request_queue(sock, req);
1547 
1548 	/* If there are a sufficient number queued, just flush them out immediately. */
1549 	if (sock->queued_iovcnt >= IOV_BATCH_SIZE) {
1550 		rc = _sock_flush(sock);
1551 		if (rc < 0 && errno != EAGAIN) {
1552 			spdk_sock_abort_requests(sock);
1553 		}
1554 	}
1555 }
1556 
1557 static int
1558 posix_sock_set_recvlowat(struct spdk_sock *_sock, int nbytes)
1559 {
1560 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1561 	int val;
1562 	int rc;
1563 
1564 	assert(sock != NULL);
1565 
1566 	val = nbytes;
1567 	rc = setsockopt(sock->fd, SOL_SOCKET, SO_RCVLOWAT, &val, sizeof val);
1568 	if (rc != 0) {
1569 		return -1;
1570 	}
1571 	return 0;
1572 }
1573 
1574 static bool
1575 posix_sock_is_ipv6(struct spdk_sock *_sock)
1576 {
1577 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1578 	struct sockaddr_storage sa;
1579 	socklen_t salen;
1580 	int rc;
1581 
1582 	assert(sock != NULL);
1583 
1584 	memset(&sa, 0, sizeof sa);
1585 	salen = sizeof sa;
1586 	rc = getsockname(sock->fd, (struct sockaddr *) &sa, &salen);
1587 	if (rc != 0) {
1588 		SPDK_ERRLOG("getsockname() failed (errno=%d)\n", errno);
1589 		return false;
1590 	}
1591 
1592 	return (sa.ss_family == AF_INET6);
1593 }
1594 
1595 static bool
1596 posix_sock_is_ipv4(struct spdk_sock *_sock)
1597 {
1598 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1599 	struct sockaddr_storage sa;
1600 	socklen_t salen;
1601 	int rc;
1602 
1603 	assert(sock != NULL);
1604 
1605 	memset(&sa, 0, sizeof sa);
1606 	salen = sizeof sa;
1607 	rc = getsockname(sock->fd, (struct sockaddr *) &sa, &salen);
1608 	if (rc != 0) {
1609 		SPDK_ERRLOG("getsockname() failed (errno=%d)\n", errno);
1610 		return false;
1611 	}
1612 
1613 	return (sa.ss_family == AF_INET);
1614 }
1615 
1616 static bool
1617 posix_sock_is_connected(struct spdk_sock *_sock)
1618 {
1619 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1620 	uint8_t byte;
1621 	int rc;
1622 
1623 	rc = recv(sock->fd, &byte, 1, MSG_PEEK);
1624 	if (rc == 0) {
1625 		return false;
1626 	}
1627 
1628 	if (rc < 0) {
1629 		if (errno == EAGAIN || errno == EWOULDBLOCK) {
1630 			return true;
1631 		}
1632 
1633 		return false;
1634 	}
1635 
1636 	return true;
1637 }
1638 
1639 static struct spdk_sock_group_impl *
1640 posix_sock_group_impl_get_optimal(struct spdk_sock *_sock, struct spdk_sock_group_impl *hint)
1641 {
1642 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1643 	struct spdk_sock_group_impl *group_impl;
1644 
1645 	if (sock->placement_id != -1) {
1646 		spdk_sock_map_lookup(&g_map, sock->placement_id, &group_impl, hint);
1647 		return group_impl;
1648 	}
1649 
1650 	return NULL;
1651 }
1652 
1653 static struct spdk_sock_group_impl *
1654 posix_sock_group_impl_create(void)
1655 {
1656 	struct spdk_posix_sock_group_impl *group_impl;
1657 	int fd;
1658 
1659 #if defined(SPDK_EPOLL)
1660 	fd = epoll_create1(0);
1661 #elif defined(SPDK_KEVENT)
1662 	fd = kqueue();
1663 #endif
1664 	if (fd == -1) {
1665 		return NULL;
1666 	}
1667 
1668 	group_impl = calloc(1, sizeof(*group_impl));
1669 	if (group_impl == NULL) {
1670 		SPDK_ERRLOG("group_impl allocation failed\n");
1671 		close(fd);
1672 		return NULL;
1673 	}
1674 
1675 	group_impl->fd = fd;
1676 	TAILQ_INIT(&group_impl->socks_with_data);
1677 	group_impl->placement_id = -1;
1678 
1679 	if (g_spdk_posix_sock_impl_opts.enable_placement_id == PLACEMENT_CPU) {
1680 		spdk_sock_map_insert(&g_map, spdk_env_get_current_core(), &group_impl->base);
1681 		group_impl->placement_id = spdk_env_get_current_core();
1682 	}
1683 
1684 	return &group_impl->base;
1685 }
1686 
1687 static void
1688 posix_sock_mark(struct spdk_posix_sock_group_impl *group, struct spdk_posix_sock *sock,
1689 		int placement_id)
1690 {
1691 #if defined(SO_MARK)
1692 	int rc;
1693 
1694 	rc = setsockopt(sock->fd, SOL_SOCKET, SO_MARK,
1695 			&placement_id, sizeof(placement_id));
1696 	if (rc != 0) {
1697 		/* Not fatal */
1698 		SPDK_ERRLOG("Error setting SO_MARK\n");
1699 		return;
1700 	}
1701 
1702 	rc = spdk_sock_map_insert(&g_map, placement_id, &group->base);
1703 	if (rc != 0) {
1704 		/* Not fatal */
1705 		SPDK_ERRLOG("Failed to insert sock group into map: %d\n", rc);
1706 		return;
1707 	}
1708 
1709 	sock->placement_id = placement_id;
1710 #endif
1711 }
1712 
1713 static void
1714 posix_sock_update_mark(struct spdk_sock_group_impl *_group, struct spdk_sock *_sock)
1715 {
1716 	struct spdk_posix_sock_group_impl *group = __posix_group_impl(_group);
1717 
1718 	if (group->placement_id == -1) {
1719 		group->placement_id = spdk_sock_map_find_free(&g_map);
1720 
1721 		/* If a free placement id is found, update existing sockets in this group */
1722 		if (group->placement_id != -1) {
1723 			struct spdk_sock  *sock, *tmp;
1724 
1725 			TAILQ_FOREACH_SAFE(sock, &_group->socks, link, tmp) {
1726 				posix_sock_mark(group, __posix_sock(sock), group->placement_id);
1727 			}
1728 		}
1729 	}
1730 
1731 	if (group->placement_id != -1) {
1732 		/*
1733 		 * group placement id is already determined for this poll group.
1734 		 * Mark socket with group's placement id.
1735 		 */
1736 		posix_sock_mark(group, __posix_sock(_sock), group->placement_id);
1737 	}
1738 }
1739 
1740 static int
1741 posix_sock_group_impl_add_sock(struct spdk_sock_group_impl *_group, struct spdk_sock *_sock)
1742 {
1743 	struct spdk_posix_sock_group_impl *group = __posix_group_impl(_group);
1744 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1745 	int rc;
1746 
1747 #if defined(SPDK_EPOLL)
1748 	struct epoll_event event;
1749 
1750 	memset(&event, 0, sizeof(event));
1751 	/* EPOLLERR is always on even if we don't set it, but be explicit for clarity */
1752 	event.events = EPOLLIN | EPOLLERR;
1753 	event.data.ptr = sock;
1754 
1755 	rc = epoll_ctl(group->fd, EPOLL_CTL_ADD, sock->fd, &event);
1756 #elif defined(SPDK_KEVENT)
1757 	struct kevent event;
1758 	struct timespec ts = {0};
1759 
1760 	EV_SET(&event, sock->fd, EVFILT_READ, EV_ADD, 0, 0, sock);
1761 
1762 	rc = kevent(group->fd, &event, 1, NULL, 0, &ts);
1763 #endif
1764 
1765 	if (rc != 0) {
1766 		return rc;
1767 	}
1768 
1769 	/* switched from another polling group due to scheduling */
1770 	if (spdk_unlikely(sock->recv_pipe != NULL  &&
1771 			  (spdk_pipe_reader_bytes_available(sock->recv_pipe) > 0))) {
1772 		sock->pipe_has_data = true;
1773 		sock->socket_has_data = false;
1774 		TAILQ_INSERT_TAIL(&group->socks_with_data, sock, link);
1775 	}
1776 
1777 	if (g_spdk_posix_sock_impl_opts.enable_placement_id == PLACEMENT_MARK) {
1778 		posix_sock_update_mark(_group, _sock);
1779 	} else if (sock->placement_id != -1) {
1780 		rc = spdk_sock_map_insert(&g_map, sock->placement_id, &group->base);
1781 		if (rc != 0) {
1782 			SPDK_ERRLOG("Failed to insert sock group into map: %d\n", rc);
1783 			/* Do not treat this as an error. The system will continue running. */
1784 		}
1785 	}
1786 
1787 	return rc;
1788 }
1789 
1790 static int
1791 posix_sock_group_impl_remove_sock(struct spdk_sock_group_impl *_group, struct spdk_sock *_sock)
1792 {
1793 	struct spdk_posix_sock_group_impl *group = __posix_group_impl(_group);
1794 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1795 	int rc;
1796 
1797 	if (sock->pipe_has_data || sock->socket_has_data) {
1798 		TAILQ_REMOVE(&group->socks_with_data, sock, link);
1799 		sock->pipe_has_data = false;
1800 		sock->socket_has_data = false;
1801 	}
1802 
1803 	if (sock->placement_id != -1) {
1804 		spdk_sock_map_release(&g_map, sock->placement_id);
1805 	}
1806 
1807 #if defined(SPDK_EPOLL)
1808 	struct epoll_event event;
1809 
1810 	/* Event parameter is ignored but some old kernel version still require it. */
1811 	rc = epoll_ctl(group->fd, EPOLL_CTL_DEL, sock->fd, &event);
1812 #elif defined(SPDK_KEVENT)
1813 	struct kevent event;
1814 	struct timespec ts = {0};
1815 
1816 	EV_SET(&event, sock->fd, EVFILT_READ, EV_DELETE, 0, 0, NULL);
1817 
1818 	rc = kevent(group->fd, &event, 1, NULL, 0, &ts);
1819 	if (rc == 0 && event.flags & EV_ERROR) {
1820 		rc = -1;
1821 		errno = event.data;
1822 	}
1823 #endif
1824 
1825 	spdk_sock_abort_requests(_sock);
1826 
1827 	return rc;
1828 }
1829 
1830 static int
1831 posix_sock_group_impl_poll(struct spdk_sock_group_impl *_group, int max_events,
1832 			   struct spdk_sock **socks)
1833 {
1834 	struct spdk_posix_sock_group_impl *group = __posix_group_impl(_group);
1835 	struct spdk_sock *sock, *tmp;
1836 	int num_events, i, rc;
1837 	struct spdk_posix_sock *psock, *ptmp;
1838 #if defined(SPDK_EPOLL)
1839 	struct epoll_event events[MAX_EVENTS_PER_POLL];
1840 #elif defined(SPDK_KEVENT)
1841 	struct kevent events[MAX_EVENTS_PER_POLL];
1842 	struct timespec ts = {0};
1843 #endif
1844 
1845 #ifdef SPDK_ZEROCOPY
1846 	/* When all of the following conditions are met
1847 	 * - non-blocking socket
1848 	 * - zero copy is enabled
1849 	 * - interrupts suppressed (i.e. busy polling)
1850 	 * - the NIC tx queue is full at the time sendmsg() is called
1851 	 * - epoll_wait determines there is an EPOLLIN event for the socket
1852 	 * then we can get into a situation where data we've sent is queued
1853 	 * up in the kernel network stack, but interrupts have been suppressed
1854 	 * because other traffic is flowing so the kernel misses the signal
1855 	 * to flush the software tx queue. If there wasn't incoming data
1856 	 * pending on the socket, then epoll_wait would have been sufficient
1857 	 * to kick off the send operation, but since there is a pending event
1858 	 * epoll_wait does not trigger the necessary operation.
1859 	 *
1860 	 * We deal with this by checking for all of the above conditions and
1861 	 * additionally looking for EPOLLIN events that were not consumed from
1862 	 * the last poll loop. We take this to mean that the upper layer is
1863 	 * unable to consume them because it is blocked waiting for resources
1864 	 * to free up, and those resources are most likely freed in response
1865 	 * to a pending asynchronous write completing.
1866 	 *
1867 	 * Additionally, sockets that have the same placement_id actually share
1868 	 * an underlying hardware queue. That means polling one of them is
1869 	 * equivalent to polling all of them. As a quick mechanism to avoid
1870 	 * making extra poll() calls, stash the last placement_id during the loop
1871 	 * and only poll if it's not the same. The overwhelmingly common case
1872 	 * is that all sockets in this list have the same placement_id because
1873 	 * SPDK is intentionally grouping sockets by that value, so even
1874 	 * though this won't stop all extra calls to poll(), it's very fast
1875 	 * and will catch all of them in practice.
1876 	 */
1877 	int last_placement_id = -1;
1878 
1879 	TAILQ_FOREACH(psock, &group->socks_with_data, link) {
1880 		if (psock->zcopy && psock->placement_id >= 0 &&
1881 		    psock->placement_id != last_placement_id) {
1882 			struct pollfd pfd = {psock->fd, POLLIN | POLLERR, 0};
1883 
1884 			poll(&pfd, 1, 0);
1885 			last_placement_id = psock->placement_id;
1886 		}
1887 	}
1888 #endif
1889 
1890 	/* This must be a TAILQ_FOREACH_SAFE because while flushing,
1891 	 * a completion callback could remove the sock from the
1892 	 * group. */
1893 	TAILQ_FOREACH_SAFE(sock, &_group->socks, link, tmp) {
1894 		rc = _sock_flush(sock);
1895 		if (rc < 0 && errno != EAGAIN) {
1896 			spdk_sock_abort_requests(sock);
1897 		}
1898 	}
1899 
1900 	assert(max_events > 0);
1901 
1902 #if defined(SPDK_EPOLL)
1903 	num_events = epoll_wait(group->fd, events, max_events, 0);
1904 #elif defined(SPDK_KEVENT)
1905 	num_events = kevent(group->fd, NULL, 0, events, max_events, &ts);
1906 #endif
1907 
1908 	if (num_events == -1) {
1909 		return -1;
1910 	} else if (num_events == 0 && !TAILQ_EMPTY(&_group->socks)) {
1911 		sock = TAILQ_FIRST(&_group->socks);
1912 		psock = __posix_sock(sock);
1913 		/* poll() is called here to busy poll the queue associated with
1914 		 * first socket in list and potentially reap incoming data.
1915 		 */
1916 		if (sock->opts.priority) {
1917 			struct pollfd pfd = {0, 0, 0};
1918 
1919 			pfd.fd = psock->fd;
1920 			pfd.events = POLLIN | POLLERR;
1921 			poll(&pfd, 1, 0);
1922 		}
1923 	}
1924 
1925 	for (i = 0; i < num_events; i++) {
1926 #if defined(SPDK_EPOLL)
1927 		sock = events[i].data.ptr;
1928 		psock = __posix_sock(sock);
1929 
1930 #ifdef SPDK_ZEROCOPY
1931 		if (events[i].events & EPOLLERR) {
1932 			rc = _sock_check_zcopy(sock);
1933 			/* If the socket was closed or removed from
1934 			 * the group in response to a send ack, don't
1935 			 * add it to the array here. */
1936 			if (rc || sock->cb_fn == NULL) {
1937 				continue;
1938 			}
1939 		}
1940 #endif
1941 		if ((events[i].events & EPOLLIN) == 0) {
1942 			continue;
1943 		}
1944 
1945 #elif defined(SPDK_KEVENT)
1946 		sock = events[i].udata;
1947 		psock = __posix_sock(sock);
1948 #endif
1949 
1950 		/* If the socket is not already in the list, add it now */
1951 		if (!psock->socket_has_data && !psock->pipe_has_data) {
1952 			TAILQ_INSERT_TAIL(&group->socks_with_data, psock, link);
1953 		}
1954 		psock->socket_has_data = true;
1955 	}
1956 
1957 	num_events = 0;
1958 
1959 	TAILQ_FOREACH_SAFE(psock, &group->socks_with_data, link, ptmp) {
1960 		if (num_events == max_events) {
1961 			break;
1962 		}
1963 
1964 		/* If the socket's cb_fn is NULL, just remove it from the
1965 		 * list and do not add it to socks array */
1966 		if (spdk_unlikely(psock->base.cb_fn == NULL)) {
1967 			psock->socket_has_data = false;
1968 			psock->pipe_has_data = false;
1969 			TAILQ_REMOVE(&group->socks_with_data, psock, link);
1970 			continue;
1971 		}
1972 
1973 		socks[num_events++] = &psock->base;
1974 	}
1975 
1976 	/* Cycle the has_data list so that each time we poll things aren't
1977 	 * in the same order. Say we have 6 sockets in the list, named as follows:
1978 	 * A B C D E F
1979 	 * And all 6 sockets had epoll events, but max_events is only 3. That means
1980 	 * psock currently points at D. We want to rearrange the list to the following:
1981 	 * D E F A B C
1982 	 *
1983 	 * The variables below are named according to this example to make it easier to
1984 	 * follow the swaps.
1985 	 */
1986 	if (psock != NULL) {
1987 		struct spdk_posix_sock *pa, *pc, *pd, *pf;
1988 
1989 		/* Capture pointers to the elements we need */
1990 		pd = psock;
1991 		pc = TAILQ_PREV(pd, spdk_has_data_list, link);
1992 		pa = TAILQ_FIRST(&group->socks_with_data);
1993 		pf = TAILQ_LAST(&group->socks_with_data, spdk_has_data_list);
1994 
1995 		/* Break the link between C and D */
1996 		pc->link.tqe_next = NULL;
1997 
1998 		/* Connect F to A */
1999 		pf->link.tqe_next = pa;
2000 		pa->link.tqe_prev = &pf->link.tqe_next;
2001 
2002 		/* Fix up the list first/last pointers */
2003 		group->socks_with_data.tqh_first = pd;
2004 		group->socks_with_data.tqh_last = &pc->link.tqe_next;
2005 
2006 		/* D is in front of the list, make tqe prev pointer point to the head of list */
2007 		pd->link.tqe_prev = &group->socks_with_data.tqh_first;
2008 	}
2009 
2010 	return num_events;
2011 }
2012 
2013 static int
2014 posix_sock_group_impl_close(struct spdk_sock_group_impl *_group)
2015 {
2016 	struct spdk_posix_sock_group_impl *group = __posix_group_impl(_group);
2017 	int rc;
2018 
2019 	if (g_spdk_posix_sock_impl_opts.enable_placement_id == PLACEMENT_CPU) {
2020 		spdk_sock_map_release(&g_map, spdk_env_get_current_core());
2021 	}
2022 
2023 	rc = close(group->fd);
2024 	free(group);
2025 	return rc;
2026 }
2027 
2028 static struct spdk_net_impl g_posix_net_impl = {
2029 	.name		= "posix",
2030 	.getaddr	= posix_sock_getaddr,
2031 	.connect	= posix_sock_connect,
2032 	.listen		= posix_sock_listen,
2033 	.accept		= posix_sock_accept,
2034 	.close		= posix_sock_close,
2035 	.recv		= posix_sock_recv,
2036 	.readv		= posix_sock_readv,
2037 	.readv_async	= posix_sock_readv_async,
2038 	.writev		= posix_sock_writev,
2039 	.writev_async	= posix_sock_writev_async,
2040 	.flush		= posix_sock_flush,
2041 	.set_recvlowat	= posix_sock_set_recvlowat,
2042 	.set_recvbuf	= posix_sock_set_recvbuf,
2043 	.set_sendbuf	= posix_sock_set_sendbuf,
2044 	.is_ipv6	= posix_sock_is_ipv6,
2045 	.is_ipv4	= posix_sock_is_ipv4,
2046 	.is_connected	= posix_sock_is_connected,
2047 	.group_impl_get_optimal	= posix_sock_group_impl_get_optimal,
2048 	.group_impl_create	= posix_sock_group_impl_create,
2049 	.group_impl_add_sock	= posix_sock_group_impl_add_sock,
2050 	.group_impl_remove_sock = posix_sock_group_impl_remove_sock,
2051 	.group_impl_poll	= posix_sock_group_impl_poll,
2052 	.group_impl_close	= posix_sock_group_impl_close,
2053 	.get_opts	= posix_sock_impl_get_opts,
2054 	.set_opts	= posix_sock_impl_set_opts,
2055 };
2056 
2057 SPDK_NET_IMPL_REGISTER(posix, &g_posix_net_impl, DEFAULT_SOCK_PRIORITY + 1);
2058 
2059 static struct spdk_sock *
2060 ssl_sock_listen(const char *ip, int port, struct spdk_sock_opts *opts)
2061 {
2062 	return posix_sock_create(ip, port, SPDK_SOCK_CREATE_LISTEN, opts, true);
2063 }
2064 
2065 static struct spdk_sock *
2066 ssl_sock_connect(const char *ip, int port, struct spdk_sock_opts *opts)
2067 {
2068 	return posix_sock_create(ip, port, SPDK_SOCK_CREATE_CONNECT, opts, true);
2069 }
2070 
2071 static struct spdk_sock *
2072 ssl_sock_accept(struct spdk_sock *_sock)
2073 {
2074 	return _posix_sock_accept(_sock, true);
2075 }
2076 
2077 static struct spdk_net_impl g_ssl_net_impl = {
2078 	.name		= "ssl",
2079 	.getaddr	= posix_sock_getaddr,
2080 	.connect	= ssl_sock_connect,
2081 	.listen		= ssl_sock_listen,
2082 	.accept		= ssl_sock_accept,
2083 	.close		= posix_sock_close,
2084 	.recv		= posix_sock_recv,
2085 	.readv		= posix_sock_readv,
2086 	.writev		= posix_sock_writev,
2087 	.writev_async	= posix_sock_writev_async,
2088 	.flush		= posix_sock_flush,
2089 	.set_recvlowat	= posix_sock_set_recvlowat,
2090 	.set_recvbuf	= posix_sock_set_recvbuf,
2091 	.set_sendbuf	= posix_sock_set_sendbuf,
2092 	.is_ipv6	= posix_sock_is_ipv6,
2093 	.is_ipv4	= posix_sock_is_ipv4,
2094 	.is_connected	= posix_sock_is_connected,
2095 	.group_impl_get_optimal	= posix_sock_group_impl_get_optimal,
2096 	.group_impl_create	= posix_sock_group_impl_create,
2097 	.group_impl_add_sock	= posix_sock_group_impl_add_sock,
2098 	.group_impl_remove_sock = posix_sock_group_impl_remove_sock,
2099 	.group_impl_poll	= posix_sock_group_impl_poll,
2100 	.group_impl_close	= posix_sock_group_impl_close,
2101 	.get_opts	= posix_sock_impl_get_opts,
2102 	.set_opts	= posix_sock_impl_set_opts,
2103 };
2104 
2105 SPDK_NET_IMPL_REGISTER(ssl, &g_ssl_net_impl, DEFAULT_SOCK_PRIORITY);
2106 SPDK_LOG_REGISTER_COMPONENT(sock_posix)
2107