xref: /spdk/module/sock/posix/posix.c (revision 1df4f4bb1853a48a986b44b49ce29af14f380bdd)
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 	.get_key = NULL,
85 	.get_key_ctx = NULL
86 };
87 
88 static struct spdk_sock_map g_map = {
89 	.entries = STAILQ_HEAD_INITIALIZER(g_map.entries),
90 	.mtx = PTHREAD_MUTEX_INITIALIZER
91 };
92 
93 __attribute((destructor)) static void
94 posix_sock_map_cleanup(void)
95 {
96 	spdk_sock_map_cleanup(&g_map);
97 }
98 
99 #define __posix_sock(sock) (struct spdk_posix_sock *)sock
100 #define __posix_group_impl(group) (struct spdk_posix_sock_group_impl *)group
101 
102 static void
103 posix_sock_copy_impl_opts(struct spdk_sock_impl_opts *dest, const struct spdk_sock_impl_opts *src,
104 			  size_t len)
105 {
106 #define FIELD_OK(field) \
107 	offsetof(struct spdk_sock_impl_opts, field) + sizeof(src->field) <= len
108 
109 #define SET_FIELD(field) \
110 	if (FIELD_OK(field)) { \
111 		dest->field = src->field; \
112 	}
113 
114 	SET_FIELD(recv_buf_size);
115 	SET_FIELD(send_buf_size);
116 	SET_FIELD(enable_recv_pipe);
117 	SET_FIELD(enable_zerocopy_send);
118 	SET_FIELD(enable_quickack);
119 	SET_FIELD(enable_placement_id);
120 	SET_FIELD(enable_zerocopy_send_server);
121 	SET_FIELD(enable_zerocopy_send_client);
122 	SET_FIELD(zerocopy_threshold);
123 	SET_FIELD(tls_version);
124 	SET_FIELD(enable_ktls);
125 	SET_FIELD(psk_key);
126 	SET_FIELD(psk_identity);
127 	SET_FIELD(get_key);
128 	SET_FIELD(get_key_ctx);
129 
130 #undef SET_FIELD
131 #undef FIELD_OK
132 }
133 
134 static int
135 posix_sock_impl_get_opts(struct spdk_sock_impl_opts *opts, size_t *len)
136 {
137 	if (!opts || !len) {
138 		errno = EINVAL;
139 		return -1;
140 	}
141 
142 	assert(sizeof(*opts) >= *len);
143 	memset(opts, 0, *len);
144 
145 	posix_sock_copy_impl_opts(opts, &g_spdk_posix_sock_impl_opts, *len);
146 	*len = spdk_min(*len, sizeof(g_spdk_posix_sock_impl_opts));
147 
148 	return 0;
149 }
150 
151 static int
152 posix_sock_impl_set_opts(const struct spdk_sock_impl_opts *opts, size_t len)
153 {
154 	if (!opts) {
155 		errno = EINVAL;
156 		return -1;
157 	}
158 
159 	assert(sizeof(*opts) >= len);
160 	posix_sock_copy_impl_opts(&g_spdk_posix_sock_impl_opts, opts, len);
161 
162 	return 0;
163 }
164 
165 static void
166 posix_opts_get_impl_opts(const struct spdk_sock_opts *opts, struct spdk_sock_impl_opts *dest)
167 {
168 	/* Copy the default impl_opts first to cover cases when user's impl_opts is smaller */
169 	memcpy(dest, &g_spdk_posix_sock_impl_opts, sizeof(*dest));
170 
171 	if (opts->impl_opts != NULL) {
172 		assert(sizeof(*dest) >= opts->impl_opts_size);
173 		posix_sock_copy_impl_opts(dest, opts->impl_opts, opts->impl_opts_size);
174 	}
175 }
176 
177 static int
178 posix_sock_getaddr(struct spdk_sock *_sock, char *saddr, int slen, uint16_t *sport,
179 		   char *caddr, int clen, uint16_t *cport)
180 {
181 	struct spdk_posix_sock *sock = __posix_sock(_sock);
182 	struct sockaddr_storage sa;
183 	socklen_t salen;
184 	int rc;
185 
186 	assert(sock != NULL);
187 
188 	memset(&sa, 0, sizeof sa);
189 	salen = sizeof sa;
190 	rc = getsockname(sock->fd, (struct sockaddr *) &sa, &salen);
191 	if (rc != 0) {
192 		SPDK_ERRLOG("getsockname() failed (errno=%d)\n", errno);
193 		return -1;
194 	}
195 
196 	switch (sa.ss_family) {
197 	case AF_UNIX:
198 		/* Acceptable connection types that don't have IPs */
199 		return 0;
200 	case AF_INET:
201 	case AF_INET6:
202 		/* Code below will get IP addresses */
203 		break;
204 	default:
205 		/* Unsupported socket family */
206 		return -1;
207 	}
208 
209 	rc = get_addr_str((struct sockaddr *)&sa, saddr, slen);
210 	if (rc != 0) {
211 		SPDK_ERRLOG("getnameinfo() failed (errno=%d)\n", errno);
212 		return -1;
213 	}
214 
215 	if (sport) {
216 		if (sa.ss_family == AF_INET) {
217 			*sport = ntohs(((struct sockaddr_in *) &sa)->sin_port);
218 		} else if (sa.ss_family == AF_INET6) {
219 			*sport = ntohs(((struct sockaddr_in6 *) &sa)->sin6_port);
220 		}
221 	}
222 
223 	memset(&sa, 0, sizeof sa);
224 	salen = sizeof sa;
225 	rc = getpeername(sock->fd, (struct sockaddr *) &sa, &salen);
226 	if (rc != 0) {
227 		SPDK_ERRLOG("getpeername() failed (errno=%d)\n", errno);
228 		return -1;
229 	}
230 
231 	rc = get_addr_str((struct sockaddr *)&sa, caddr, clen);
232 	if (rc != 0) {
233 		SPDK_ERRLOG("getnameinfo() failed (errno=%d)\n", errno);
234 		return -1;
235 	}
236 
237 	if (cport) {
238 		if (sa.ss_family == AF_INET) {
239 			*cport = ntohs(((struct sockaddr_in *) &sa)->sin_port);
240 		} else if (sa.ss_family == AF_INET6) {
241 			*cport = ntohs(((struct sockaddr_in6 *) &sa)->sin6_port);
242 		}
243 	}
244 
245 	return 0;
246 }
247 
248 enum posix_sock_create_type {
249 	SPDK_SOCK_CREATE_LISTEN,
250 	SPDK_SOCK_CREATE_CONNECT,
251 };
252 
253 static int
254 posix_sock_alloc_pipe(struct spdk_posix_sock *sock, int sz)
255 {
256 	uint8_t *new_buf;
257 	struct spdk_pipe *new_pipe;
258 	struct iovec siov[2];
259 	struct iovec diov[2];
260 	int sbytes;
261 	ssize_t bytes;
262 	int rc;
263 
264 	if (sock->recv_buf_sz == sz) {
265 		return 0;
266 	}
267 
268 	/* If the new size is 0, just free the pipe */
269 	if (sz == 0) {
270 		spdk_pipe_destroy(sock->recv_pipe);
271 		free(sock->recv_buf);
272 		sock->recv_pipe = NULL;
273 		sock->recv_buf = NULL;
274 		return 0;
275 	} else if (sz < MIN_SOCK_PIPE_SIZE) {
276 		SPDK_ERRLOG("The size of the pipe must be larger than %d\n", MIN_SOCK_PIPE_SIZE);
277 		return -1;
278 	}
279 
280 	/* Round up to next 64 byte multiple */
281 	rc = posix_memalign((void **)&new_buf, 64, sz);
282 	if (rc != 0) {
283 		SPDK_ERRLOG("socket recv buf allocation failed\n");
284 		return -ENOMEM;
285 	}
286 	memset(new_buf, 0, sz);
287 
288 	new_pipe = spdk_pipe_create(new_buf, sz);
289 	if (new_pipe == NULL) {
290 		SPDK_ERRLOG("socket pipe allocation failed\n");
291 		free(new_buf);
292 		return -ENOMEM;
293 	}
294 
295 	if (sock->recv_pipe != NULL) {
296 		/* Pull all of the data out of the old pipe */
297 		sbytes = spdk_pipe_reader_get_buffer(sock->recv_pipe, sock->recv_buf_sz, siov);
298 		if (sbytes > sz) {
299 			/* Too much data to fit into the new pipe size */
300 			spdk_pipe_destroy(new_pipe);
301 			free(new_buf);
302 			return -EINVAL;
303 		}
304 
305 		sbytes = spdk_pipe_writer_get_buffer(new_pipe, sz, diov);
306 		assert(sbytes == sz);
307 
308 		bytes = spdk_iovcpy(siov, 2, diov, 2);
309 		spdk_pipe_writer_advance(new_pipe, bytes);
310 
311 		spdk_pipe_destroy(sock->recv_pipe);
312 		free(sock->recv_buf);
313 	}
314 
315 	sock->recv_buf_sz = sz;
316 	sock->recv_buf = new_buf;
317 	sock->recv_pipe = new_pipe;
318 
319 	return 0;
320 }
321 
322 static int
323 posix_sock_set_recvbuf(struct spdk_sock *_sock, int sz)
324 {
325 	struct spdk_posix_sock *sock = __posix_sock(_sock);
326 	int min_size;
327 	int rc;
328 
329 	assert(sock != NULL);
330 
331 	if (_sock->impl_opts.enable_recv_pipe) {
332 		rc = posix_sock_alloc_pipe(sock, sz);
333 		if (rc) {
334 			return rc;
335 		}
336 	}
337 
338 	/* Set kernel buffer size to be at least MIN_SO_RCVBUF_SIZE and
339 	 * g_spdk_posix_sock_impl_opts.recv_buf_size. */
340 	min_size = spdk_max(MIN_SO_RCVBUF_SIZE, g_spdk_posix_sock_impl_opts.recv_buf_size);
341 
342 	if (sz < min_size) {
343 		sz = min_size;
344 	}
345 
346 	rc = setsockopt(sock->fd, SOL_SOCKET, SO_RCVBUF, &sz, sizeof(sz));
347 	if (rc < 0) {
348 		return rc;
349 	}
350 
351 	_sock->impl_opts.recv_buf_size = sz;
352 
353 	return 0;
354 }
355 
356 static int
357 posix_sock_set_sendbuf(struct spdk_sock *_sock, int sz)
358 {
359 	struct spdk_posix_sock *sock = __posix_sock(_sock);
360 	int min_size;
361 	int rc;
362 
363 	assert(sock != NULL);
364 
365 	/* Set kernel buffer size to be at least MIN_SO_SNDBUF_SIZE and
366 	 * g_spdk_posix_sock_impl_opts.send_buf_size. */
367 	min_size = spdk_max(MIN_SO_SNDBUF_SIZE, g_spdk_posix_sock_impl_opts.send_buf_size);
368 
369 	if (sz < min_size) {
370 		sz = min_size;
371 	}
372 
373 	rc = setsockopt(sock->fd, SOL_SOCKET, SO_SNDBUF, &sz, sizeof(sz));
374 	if (rc < 0) {
375 		return rc;
376 	}
377 
378 	_sock->impl_opts.send_buf_size = sz;
379 
380 	return 0;
381 }
382 
383 static void
384 posix_sock_init(struct spdk_posix_sock *sock, bool enable_zero_copy)
385 {
386 #if defined(SPDK_ZEROCOPY) || defined(__linux__)
387 	int flag;
388 	int rc;
389 #endif
390 
391 #if defined(SPDK_ZEROCOPY)
392 	flag = 1;
393 
394 	if (enable_zero_copy) {
395 		/* Try to turn on zero copy sends */
396 		rc = setsockopt(sock->fd, SOL_SOCKET, SO_ZEROCOPY, &flag, sizeof(flag));
397 		if (rc == 0) {
398 			sock->zcopy = true;
399 		}
400 	}
401 #endif
402 
403 #if defined(__linux__)
404 	flag = 1;
405 
406 	if (sock->base.impl_opts.enable_quickack) {
407 		rc = setsockopt(sock->fd, IPPROTO_TCP, TCP_QUICKACK, &flag, sizeof(flag));
408 		if (rc != 0) {
409 			SPDK_ERRLOG("quickack was failed to set\n");
410 		}
411 	}
412 
413 	spdk_sock_get_placement_id(sock->fd, sock->base.impl_opts.enable_placement_id,
414 				   &sock->placement_id);
415 
416 	if (sock->base.impl_opts.enable_placement_id == PLACEMENT_MARK) {
417 		/* Save placement_id */
418 		spdk_sock_map_insert(&g_map, sock->placement_id, NULL);
419 	}
420 #endif
421 }
422 
423 static struct spdk_posix_sock *
424 posix_sock_alloc(int fd, struct spdk_sock_impl_opts *impl_opts, bool enable_zero_copy)
425 {
426 	struct spdk_posix_sock *sock;
427 
428 	sock = calloc(1, sizeof(*sock));
429 	if (sock == NULL) {
430 		SPDK_ERRLOG("sock allocation failed\n");
431 		return NULL;
432 	}
433 
434 	sock->fd = fd;
435 	memcpy(&sock->base.impl_opts, impl_opts, sizeof(*impl_opts));
436 	posix_sock_init(sock, enable_zero_copy);
437 
438 	return sock;
439 }
440 
441 static int
442 posix_fd_create(struct addrinfo *res, struct spdk_sock_opts *opts,
443 		struct spdk_sock_impl_opts *impl_opts)
444 {
445 	int fd;
446 	int val = 1;
447 	int rc, sz;
448 #if defined(__linux__)
449 	int to;
450 #endif
451 
452 	fd = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
453 	if (fd < 0) {
454 		/* error */
455 		return -1;
456 	}
457 
458 	sz = impl_opts->recv_buf_size;
459 	rc = setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &sz, sizeof(sz));
460 	if (rc) {
461 		/* Not fatal */
462 	}
463 
464 	sz = impl_opts->send_buf_size;
465 	rc = setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &sz, sizeof(sz));
466 	if (rc) {
467 		/* Not fatal */
468 	}
469 
470 	rc = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof val);
471 	if (rc != 0) {
472 		close(fd);
473 		/* error */
474 		return -1;
475 	}
476 	rc = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &val, sizeof val);
477 	if (rc != 0) {
478 		close(fd);
479 		/* error */
480 		return -1;
481 	}
482 
483 #if defined(SO_PRIORITY)
484 	if (opts->priority) {
485 		rc = setsockopt(fd, SOL_SOCKET, SO_PRIORITY, &opts->priority, sizeof val);
486 		if (rc != 0) {
487 			close(fd);
488 			/* error */
489 			return -1;
490 		}
491 	}
492 #endif
493 
494 	if (res->ai_family == AF_INET6) {
495 		rc = setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof val);
496 		if (rc != 0) {
497 			close(fd);
498 			/* error */
499 			return -1;
500 		}
501 	}
502 
503 	if (opts->ack_timeout) {
504 #if defined(__linux__)
505 		to = opts->ack_timeout;
506 		rc = setsockopt(fd, IPPROTO_TCP, TCP_USER_TIMEOUT, &to, sizeof(to));
507 		if (rc != 0) {
508 			close(fd);
509 			/* error */
510 			return -1;
511 		}
512 #else
513 		SPDK_WARNLOG("TCP_USER_TIMEOUT is not supported.\n");
514 #endif
515 	}
516 
517 	return fd;
518 }
519 
520 static unsigned int
521 posix_sock_tls_psk_server_cb(SSL *ssl,
522 			     const char *id,
523 			     unsigned char *psk,
524 			     unsigned int max_psk_len)
525 {
526 	long key_len;
527 	unsigned char *psk_k = NULL;
528 	const char *cipher = NULL;
529 	struct spdk_sock_impl_opts *impl_opts;
530 	uint8_t sock_psk[PSK_MAX_PSK_LEN] = {};
531 	int rc;
532 
533 	impl_opts = SSL_get_app_data(ssl);
534 	SPDK_DEBUGLOG(sock_posix, "Received PSK ID '%s'\n", id);
535 	if (id == NULL) {
536 		SPDK_ERRLOG("Received empty PSK ID\n");
537 		goto err;
538 	}
539 
540 	SPDK_DEBUGLOG(sock_posix, "Length of Client's PSK KEY %u\n", max_psk_len);
541 
542 	if (impl_opts->get_key) {
543 		rc = impl_opts->get_key(sock_psk, PSK_MAX_PSK_LEN, &cipher, id, impl_opts->get_key_ctx);
544 		assert(cipher == NULL);
545 		if (rc < 0) {
546 			goto err;
547 		}
548 		psk_k = OPENSSL_hexstr2buf(sock_psk, &key_len);
549 	} else {
550 		if (impl_opts->psk_key == NULL) {
551 			SPDK_ERRLOG("PSK is not set\n");
552 			goto err;
553 		}
554 
555 		SPDK_DEBUGLOG(sock_posix, "Length of Client's PSK ID %lu\n", strlen(impl_opts->psk_identity));
556 		if (strcmp(impl_opts->psk_identity, id) != 0) {
557 			SPDK_ERRLOG("Unknown Client's PSK ID\n");
558 			goto err;
559 		}
560 		psk_k = OPENSSL_hexstr2buf(impl_opts->psk_key, &key_len);
561 	}
562 	if (psk_k == NULL) {
563 		SPDK_ERRLOG("Could not unhexlify PSK\n");
564 		goto err;
565 	}
566 	if (key_len > max_psk_len) {
567 		SPDK_ERRLOG("Insufficient buffer size to copy PSK\n");
568 		OPENSSL_free(psk_k);
569 		goto err;
570 	}
571 	memcpy(psk, psk_k, key_len);
572 	OPENSSL_free(psk_k);
573 
574 	return key_len;
575 
576 err:
577 	return 0;
578 }
579 
580 static unsigned int
581 posix_sock_tls_psk_client_cb(SSL *ssl, const char *hint,
582 			     char *identity,
583 			     unsigned int max_identity_len,
584 			     unsigned char *psk,
585 			     unsigned int max_psk_len)
586 {
587 	long key_len;
588 	unsigned char *default_psk;
589 	struct spdk_sock_impl_opts *impl_opts;
590 
591 	impl_opts = SSL_get_app_data(ssl);
592 
593 	if (hint) {
594 		SPDK_DEBUGLOG(sock_posix,  "Received PSK identity hint '%s'\n", hint);
595 	}
596 
597 	if (impl_opts->psk_key == NULL) {
598 		SPDK_ERRLOG("PSK is not set\n");
599 		goto err;
600 	}
601 	default_psk = OPENSSL_hexstr2buf(impl_opts->psk_key, &key_len);
602 	if (default_psk == NULL) {
603 		SPDK_ERRLOG("Could not unhexlify PSK\n");
604 		goto err;
605 	}
606 	if ((strlen(impl_opts->psk_identity) + 1 > max_identity_len)
607 	    || (key_len > max_psk_len)) {
608 		OPENSSL_free(default_psk);
609 		SPDK_ERRLOG("PSK ID or Key buffer is not sufficient\n");
610 		goto err;
611 	}
612 	spdk_strcpy_pad(identity, impl_opts->psk_identity, strlen(impl_opts->psk_identity), 0);
613 	SPDK_DEBUGLOG(sock_posix, "Sending PSK identity '%s'\n", identity);
614 
615 	memcpy(psk, default_psk, key_len);
616 	SPDK_DEBUGLOG(sock_posix, "Provided out-of-band (OOB) PSK for TLS1.3 client\n");
617 	OPENSSL_free(default_psk);
618 
619 	return key_len;
620 
621 err:
622 	return 0;
623 }
624 
625 static SSL_CTX *
626 posix_sock_create_ssl_context(const SSL_METHOD *method, struct spdk_sock_opts *opts,
627 			      struct spdk_sock_impl_opts *impl_opts)
628 {
629 	SSL_CTX *ctx;
630 	int tls_version = 0;
631 	bool ktls_enabled = false;
632 #ifdef SSL_OP_ENABLE_KTLS
633 	long options;
634 #endif
635 
636 	SSL_library_init();
637 	OpenSSL_add_all_algorithms();
638 	SSL_load_error_strings();
639 	/* Produce a SSL CTX in SSL V2 and V3 standards compliant way */
640 	ctx = SSL_CTX_new(method);
641 	if (!ctx) {
642 		SPDK_ERRLOG("SSL_CTX_new() failed, msg = %s\n", ERR_error_string(ERR_peek_last_error(), NULL));
643 		return NULL;
644 	}
645 	SPDK_DEBUGLOG(sock_posix, "SSL context created\n");
646 
647 	switch (impl_opts->tls_version) {
648 	case 0:
649 		/* auto-negotioation */
650 		break;
651 	case SPDK_TLS_VERSION_1_1:
652 		tls_version = TLS1_1_VERSION;
653 		break;
654 	case SPDK_TLS_VERSION_1_2:
655 		tls_version = TLS1_2_VERSION;
656 		break;
657 	case SPDK_TLS_VERSION_1_3:
658 		tls_version = TLS1_3_VERSION;
659 		break;
660 	default:
661 		SPDK_ERRLOG("Incorrect TLS version provided: %d\n", impl_opts->tls_version);
662 		goto err;
663 	}
664 
665 	if (tls_version) {
666 		SPDK_DEBUGLOG(sock_posix, "Hardening TLS version to '%d'='0x%X'\n", impl_opts->tls_version,
667 			      tls_version);
668 		if (!SSL_CTX_set_min_proto_version(ctx, tls_version)) {
669 			SPDK_ERRLOG("Unable to set Min TLS version to '%d'='0x%X\n", impl_opts->tls_version, tls_version);
670 			goto err;
671 		}
672 		if (!SSL_CTX_set_max_proto_version(ctx, tls_version)) {
673 			SPDK_ERRLOG("Unable to set Max TLS version to '%d'='0x%X\n", impl_opts->tls_version, tls_version);
674 			goto err;
675 		}
676 	}
677 	if (impl_opts->enable_ktls) {
678 		SPDK_DEBUGLOG(sock_posix, "Enabling kTLS offload\n");
679 #ifdef SSL_OP_ENABLE_KTLS
680 		options = SSL_CTX_set_options(ctx, SSL_OP_ENABLE_KTLS);
681 		ktls_enabled = options & SSL_OP_ENABLE_KTLS;
682 #else
683 		ktls_enabled = false;
684 #endif
685 		if (!ktls_enabled) {
686 			SPDK_ERRLOG("Unable to set kTLS offload via SSL_CTX_set_options(). Configure openssl with 'enable-ktls'\n");
687 			goto err;
688 		}
689 	}
690 
691 	return ctx;
692 
693 err:
694 	SSL_CTX_free(ctx);
695 	return NULL;
696 }
697 
698 static SSL *
699 ssl_sock_connect_loop(SSL_CTX *ctx, int fd, struct spdk_sock_impl_opts *impl_opts)
700 {
701 	int rc;
702 	SSL *ssl;
703 	int ssl_get_error;
704 
705 	ssl = SSL_new(ctx);
706 	if (!ssl) {
707 		SPDK_ERRLOG("SSL_new() failed, msg = %s\n", ERR_error_string(ERR_peek_last_error(), NULL));
708 		return NULL;
709 	}
710 	SSL_set_fd(ssl, fd);
711 	SSL_set_app_data(ssl, impl_opts);
712 	SSL_set_psk_client_callback(ssl, posix_sock_tls_psk_client_cb);
713 	SPDK_DEBUGLOG(sock_posix, "SSL object creation finished: %p\n", ssl);
714 	SPDK_DEBUGLOG(sock_posix, "%s = SSL_state_string_long(%p)\n", SSL_state_string_long(ssl), ssl);
715 	while ((rc = SSL_connect(ssl)) != 1) {
716 		SPDK_DEBUGLOG(sock_posix, "%s = SSL_state_string_long(%p)\n", SSL_state_string_long(ssl), ssl);
717 		ssl_get_error = SSL_get_error(ssl, rc);
718 		SPDK_DEBUGLOG(sock_posix, "SSL_connect failed %d = SSL_connect(%p), %d = SSL_get_error(%p, %d)\n",
719 			      rc, ssl, ssl_get_error, ssl, rc);
720 		switch (ssl_get_error) {
721 		case SSL_ERROR_WANT_READ:
722 		case SSL_ERROR_WANT_WRITE:
723 			continue;
724 		default:
725 			break;
726 		}
727 		SPDK_ERRLOG("SSL_connect() failed, errno = %d\n", errno);
728 		SSL_free(ssl);
729 		return NULL;
730 	}
731 	SPDK_DEBUGLOG(sock_posix, "%s = SSL_state_string_long(%p)\n", SSL_state_string_long(ssl), ssl);
732 	SPDK_DEBUGLOG(sock_posix, "Negotiated Cipher suite:%s\n",
733 		      SSL_CIPHER_get_name(SSL_get_current_cipher(ssl)));
734 	return ssl;
735 }
736 
737 static SSL *
738 ssl_sock_accept_loop(SSL_CTX *ctx, int fd, struct spdk_sock_impl_opts *impl_opts)
739 {
740 	int rc;
741 	SSL *ssl;
742 	int ssl_get_error;
743 
744 	ssl = SSL_new(ctx);
745 	if (!ssl) {
746 		SPDK_ERRLOG("SSL_new() failed, msg = %s\n", ERR_error_string(ERR_peek_last_error(), NULL));
747 		return NULL;
748 	}
749 	SSL_set_fd(ssl, fd);
750 	SSL_set_app_data(ssl, impl_opts);
751 	SSL_set_psk_server_callback(ssl, posix_sock_tls_psk_server_cb);
752 	SPDK_DEBUGLOG(sock_posix, "SSL object creation finished: %p\n", ssl);
753 	SPDK_DEBUGLOG(sock_posix, "%s = SSL_state_string_long(%p)\n", SSL_state_string_long(ssl), ssl);
754 	while ((rc = SSL_accept(ssl)) != 1) {
755 		SPDK_DEBUGLOG(sock_posix, "%s = SSL_state_string_long(%p)\n", SSL_state_string_long(ssl), ssl);
756 		ssl_get_error = SSL_get_error(ssl, rc);
757 		SPDK_DEBUGLOG(sock_posix, "SSL_accept failed %d = SSL_accept(%p), %d = SSL_get_error(%p, %d)\n", rc,
758 			      ssl, ssl_get_error, ssl, rc);
759 		switch (ssl_get_error) {
760 		case SSL_ERROR_WANT_READ:
761 		case SSL_ERROR_WANT_WRITE:
762 			continue;
763 		default:
764 			break;
765 		}
766 		SPDK_ERRLOG("SSL_accept() failed, errno = %d\n", errno);
767 		SSL_free(ssl);
768 		return NULL;
769 	}
770 	SPDK_DEBUGLOG(sock_posix, "%s = SSL_state_string_long(%p)\n", SSL_state_string_long(ssl), ssl);
771 	SPDK_DEBUGLOG(sock_posix, "Negotiated Cipher suite:%s\n",
772 		      SSL_CIPHER_get_name(SSL_get_current_cipher(ssl)));
773 	return ssl;
774 }
775 
776 static ssize_t
777 SSL_readv(SSL *ssl, const struct iovec *iov, int iovcnt)
778 {
779 	int i, rc = 0;
780 	ssize_t total = 0;
781 
782 	for (i = 0; i < iovcnt; i++) {
783 		rc = SSL_read(ssl, iov[i].iov_base, iov[i].iov_len);
784 
785 		if (rc > 0) {
786 			total += rc;
787 		}
788 		if (rc != (int)iov[i].iov_len) {
789 			break;
790 		}
791 	}
792 	if (total > 0) {
793 		errno = 0;
794 		return total;
795 	}
796 	switch (SSL_get_error(ssl, rc)) {
797 	case SSL_ERROR_ZERO_RETURN:
798 		errno = ENOTCONN;
799 		return 0;
800 	case SSL_ERROR_WANT_READ:
801 	case SSL_ERROR_WANT_WRITE:
802 	case SSL_ERROR_WANT_CONNECT:
803 	case SSL_ERROR_WANT_ACCEPT:
804 	case SSL_ERROR_WANT_X509_LOOKUP:
805 	case SSL_ERROR_WANT_ASYNC:
806 	case SSL_ERROR_WANT_ASYNC_JOB:
807 	case SSL_ERROR_WANT_CLIENT_HELLO_CB:
808 		errno = EAGAIN;
809 		return -1;
810 	case SSL_ERROR_SYSCALL:
811 	case SSL_ERROR_SSL:
812 		errno = ENOTCONN;
813 		return -1;
814 	default:
815 		errno = ENOTCONN;
816 		return -1;
817 	}
818 }
819 
820 static ssize_t
821 SSL_writev(SSL *ssl, struct iovec *iov, int iovcnt)
822 {
823 	int i, rc = 0;
824 	ssize_t total = 0;
825 
826 	for (i = 0; i < iovcnt; i++) {
827 		rc = SSL_write(ssl, iov[i].iov_base, iov[i].iov_len);
828 
829 		if (rc > 0) {
830 			total += rc;
831 		}
832 		if (rc != (int)iov[i].iov_len) {
833 			break;
834 		}
835 	}
836 	if (total > 0) {
837 		errno = 0;
838 		return total;
839 	}
840 	switch (SSL_get_error(ssl, rc)) {
841 	case SSL_ERROR_ZERO_RETURN:
842 		errno = ENOTCONN;
843 		return 0;
844 	case SSL_ERROR_WANT_READ:
845 	case SSL_ERROR_WANT_WRITE:
846 	case SSL_ERROR_WANT_CONNECT:
847 	case SSL_ERROR_WANT_ACCEPT:
848 	case SSL_ERROR_WANT_X509_LOOKUP:
849 	case SSL_ERROR_WANT_ASYNC:
850 	case SSL_ERROR_WANT_ASYNC_JOB:
851 	case SSL_ERROR_WANT_CLIENT_HELLO_CB:
852 		errno = EAGAIN;
853 		return -1;
854 	case SSL_ERROR_SYSCALL:
855 	case SSL_ERROR_SSL:
856 		errno = ENOTCONN;
857 		return -1;
858 	default:
859 		errno = ENOTCONN;
860 		return -1;
861 	}
862 }
863 
864 static struct spdk_sock *
865 posix_sock_create(const char *ip, int port,
866 		  enum posix_sock_create_type type,
867 		  struct spdk_sock_opts *opts,
868 		  bool enable_ssl)
869 {
870 	struct spdk_posix_sock *sock;
871 	struct spdk_sock_impl_opts impl_opts;
872 	char buf[MAX_TMPBUF];
873 	char portnum[PORTNUMLEN];
874 	char *p;
875 	struct addrinfo hints, *res, *res0;
876 	int fd, flag;
877 	int rc;
878 	bool enable_zcopy_user_opts = true;
879 	bool enable_zcopy_impl_opts = true;
880 	SSL_CTX *ctx = 0;
881 	SSL *ssl = 0;
882 
883 	assert(opts != NULL);
884 	posix_opts_get_impl_opts(opts, &impl_opts);
885 
886 	if (ip == NULL) {
887 		return NULL;
888 	}
889 	if (ip[0] == '[') {
890 		snprintf(buf, sizeof(buf), "%s", ip + 1);
891 		p = strchr(buf, ']');
892 		if (p != NULL) {
893 			*p = '\0';
894 		}
895 		ip = (const char *) &buf[0];
896 	}
897 
898 	snprintf(portnum, sizeof portnum, "%d", port);
899 	memset(&hints, 0, sizeof hints);
900 	hints.ai_family = PF_UNSPEC;
901 	hints.ai_socktype = SOCK_STREAM;
902 	hints.ai_flags = AI_NUMERICSERV;
903 	hints.ai_flags |= AI_PASSIVE;
904 	hints.ai_flags |= AI_NUMERICHOST;
905 	rc = getaddrinfo(ip, portnum, &hints, &res0);
906 	if (rc != 0) {
907 		SPDK_ERRLOG("getaddrinfo() failed %s (%d)\n", gai_strerror(rc), rc);
908 		return NULL;
909 	}
910 
911 	/* try listen */
912 	fd = -1;
913 	for (res = res0; res != NULL; res = res->ai_next) {
914 retry:
915 		fd = posix_fd_create(res, opts, &impl_opts);
916 		if (fd < 0) {
917 			continue;
918 		}
919 		if (type == SPDK_SOCK_CREATE_LISTEN) {
920 			rc = bind(fd, res->ai_addr, res->ai_addrlen);
921 			if (rc != 0) {
922 				SPDK_ERRLOG("bind() failed at port %d, errno = %d\n", port, errno);
923 				switch (errno) {
924 				case EINTR:
925 					/* interrupted? */
926 					close(fd);
927 					goto retry;
928 				case EADDRNOTAVAIL:
929 					SPDK_ERRLOG("IP address %s not available. "
930 						    "Verify IP address in config file "
931 						    "and make sure setup script is "
932 						    "run before starting spdk app.\n", ip);
933 				/* FALLTHROUGH */
934 				default:
935 					/* try next family */
936 					close(fd);
937 					fd = -1;
938 					continue;
939 				}
940 			}
941 			/* bind OK */
942 			rc = listen(fd, 512);
943 			if (rc != 0) {
944 				SPDK_ERRLOG("listen() failed, errno = %d\n", errno);
945 				close(fd);
946 				fd = -1;
947 				break;
948 			}
949 			enable_zcopy_impl_opts = impl_opts.enable_zerocopy_send_server;
950 		} else if (type == SPDK_SOCK_CREATE_CONNECT) {
951 			rc = connect(fd, res->ai_addr, res->ai_addrlen);
952 			if (rc != 0) {
953 				SPDK_ERRLOG("connect() failed, errno = %d\n", errno);
954 				/* try next family */
955 				close(fd);
956 				fd = -1;
957 				continue;
958 			}
959 			enable_zcopy_impl_opts = impl_opts.enable_zerocopy_send_client;
960 			if (enable_ssl) {
961 				ctx = posix_sock_create_ssl_context(TLS_client_method(), opts, &impl_opts);
962 				if (!ctx) {
963 					SPDK_ERRLOG("posix_sock_create_ssl_context() failed, errno = %d\n", errno);
964 					close(fd);
965 					fd = -1;
966 					break;
967 				}
968 				ssl = ssl_sock_connect_loop(ctx, fd, &impl_opts);
969 				if (!ssl) {
970 					SPDK_ERRLOG("ssl_sock_connect_loop() failed, errno = %d\n", errno);
971 					close(fd);
972 					fd = -1;
973 					SSL_CTX_free(ctx);
974 					break;
975 				}
976 			}
977 		}
978 
979 		flag = fcntl(fd, F_GETFL);
980 		if (fcntl(fd, F_SETFL, flag | O_NONBLOCK) < 0) {
981 			SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%d)\n", fd, errno);
982 			SSL_free(ssl);
983 			SSL_CTX_free(ctx);
984 			close(fd);
985 			fd = -1;
986 			break;
987 		}
988 		break;
989 	}
990 	freeaddrinfo(res0);
991 
992 	if (fd < 0) {
993 		return NULL;
994 	}
995 
996 	/* Only enable zero copy for non-loopback and non-ssl sockets. */
997 	enable_zcopy_user_opts = opts->zcopy && !sock_is_loopback(fd) && !enable_ssl;
998 
999 	sock = posix_sock_alloc(fd, &impl_opts, enable_zcopy_user_opts && enable_zcopy_impl_opts);
1000 	if (sock == NULL) {
1001 		SPDK_ERRLOG("sock allocation failed\n");
1002 		SSL_free(ssl);
1003 		SSL_CTX_free(ctx);
1004 		close(fd);
1005 		return NULL;
1006 	}
1007 
1008 	if (ctx) {
1009 		sock->ctx = ctx;
1010 	}
1011 
1012 	if (ssl) {
1013 		sock->ssl = ssl;
1014 	}
1015 
1016 	return &sock->base;
1017 }
1018 
1019 static struct spdk_sock *
1020 posix_sock_listen(const char *ip, int port, struct spdk_sock_opts *opts)
1021 {
1022 	return posix_sock_create(ip, port, SPDK_SOCK_CREATE_LISTEN, opts, false);
1023 }
1024 
1025 static struct spdk_sock *
1026 posix_sock_connect(const char *ip, int port, struct spdk_sock_opts *opts)
1027 {
1028 	return posix_sock_create(ip, port, SPDK_SOCK_CREATE_CONNECT, opts, false);
1029 }
1030 
1031 static struct spdk_sock *
1032 _posix_sock_accept(struct spdk_sock *_sock, bool enable_ssl)
1033 {
1034 	struct spdk_posix_sock		*sock = __posix_sock(_sock);
1035 	struct sockaddr_storage		sa;
1036 	socklen_t			salen;
1037 	int				rc, fd;
1038 	struct spdk_posix_sock		*new_sock;
1039 	int				flag;
1040 	SSL_CTX *ctx = 0;
1041 	SSL *ssl = 0;
1042 
1043 	memset(&sa, 0, sizeof(sa));
1044 	salen = sizeof(sa);
1045 
1046 	assert(sock != NULL);
1047 
1048 	rc = accept(sock->fd, (struct sockaddr *)&sa, &salen);
1049 
1050 	if (rc == -1) {
1051 		return NULL;
1052 	}
1053 
1054 	fd = rc;
1055 
1056 	flag = fcntl(fd, F_GETFL);
1057 	if ((!(flag & O_NONBLOCK)) && (fcntl(fd, F_SETFL, flag | O_NONBLOCK) < 0)) {
1058 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%d)\n", fd, errno);
1059 		close(fd);
1060 		return NULL;
1061 	}
1062 
1063 #if defined(SO_PRIORITY)
1064 	/* The priority is not inherited, so call this function again */
1065 	if (sock->base.opts.priority) {
1066 		rc = setsockopt(fd, SOL_SOCKET, SO_PRIORITY, &sock->base.opts.priority, sizeof(int));
1067 		if (rc != 0) {
1068 			close(fd);
1069 			return NULL;
1070 		}
1071 	}
1072 #endif
1073 
1074 	/* Establish SSL connection */
1075 	if (enable_ssl) {
1076 		ctx = posix_sock_create_ssl_context(TLS_server_method(), &sock->base.opts, &sock->base.impl_opts);
1077 		if (!ctx) {
1078 			SPDK_ERRLOG("posix_sock_create_ssl_context() failed, errno = %d\n", errno);
1079 			close(fd);
1080 			return NULL;
1081 		}
1082 		ssl = ssl_sock_accept_loop(ctx, fd, &sock->base.impl_opts);
1083 		if (!ssl) {
1084 			SPDK_ERRLOG("ssl_sock_accept_loop() failed, errno = %d\n", errno);
1085 			close(fd);
1086 			SSL_CTX_free(ctx);
1087 			return NULL;
1088 		}
1089 	}
1090 
1091 	/* Inherit the zero copy feature from the listen socket */
1092 	new_sock = posix_sock_alloc(fd, &sock->base.impl_opts, sock->zcopy);
1093 	if (new_sock == NULL) {
1094 		close(fd);
1095 		SSL_free(ssl);
1096 		SSL_CTX_free(ctx);
1097 		return NULL;
1098 	}
1099 
1100 	if (ctx) {
1101 		new_sock->ctx = ctx;
1102 	}
1103 
1104 	if (ssl) {
1105 		new_sock->ssl = ssl;
1106 	}
1107 
1108 	return &new_sock->base;
1109 }
1110 
1111 static struct spdk_sock *
1112 posix_sock_accept(struct spdk_sock *_sock)
1113 {
1114 	return _posix_sock_accept(_sock, false);
1115 }
1116 
1117 static int
1118 posix_sock_close(struct spdk_sock *_sock)
1119 {
1120 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1121 
1122 	assert(TAILQ_EMPTY(&_sock->pending_reqs));
1123 
1124 	if (sock->ssl != NULL) {
1125 		SSL_shutdown(sock->ssl);
1126 	}
1127 
1128 	/* If the socket fails to close, the best choice is to
1129 	 * leak the fd but continue to free the rest of the sock
1130 	 * memory. */
1131 	close(sock->fd);
1132 
1133 	SSL_free(sock->ssl);
1134 	SSL_CTX_free(sock->ctx);
1135 
1136 	spdk_pipe_destroy(sock->recv_pipe);
1137 	free(sock->recv_buf);
1138 	free(sock);
1139 
1140 	return 0;
1141 }
1142 
1143 #ifdef SPDK_ZEROCOPY
1144 static int
1145 _sock_check_zcopy(struct spdk_sock *sock)
1146 {
1147 	struct spdk_posix_sock *psock = __posix_sock(sock);
1148 	struct msghdr msgh = {};
1149 	uint8_t buf[sizeof(struct cmsghdr) + sizeof(struct sock_extended_err)];
1150 	ssize_t rc;
1151 	struct sock_extended_err *serr;
1152 	struct cmsghdr *cm;
1153 	uint32_t idx;
1154 	struct spdk_sock_request *req, *treq;
1155 	bool found;
1156 
1157 	msgh.msg_control = buf;
1158 	msgh.msg_controllen = sizeof(buf);
1159 
1160 	while (true) {
1161 		rc = recvmsg(psock->fd, &msgh, MSG_ERRQUEUE);
1162 
1163 		if (rc < 0) {
1164 			if (errno == EWOULDBLOCK || errno == EAGAIN) {
1165 				return 0;
1166 			}
1167 
1168 			if (!TAILQ_EMPTY(&sock->pending_reqs)) {
1169 				SPDK_ERRLOG("Attempting to receive from ERRQUEUE yielded error, but pending list still has orphaned entries\n");
1170 			} else {
1171 				SPDK_WARNLOG("Recvmsg yielded an error!\n");
1172 			}
1173 			return 0;
1174 		}
1175 
1176 		cm = CMSG_FIRSTHDR(&msgh);
1177 		if (!(cm &&
1178 		      ((cm->cmsg_level == SOL_IP && cm->cmsg_type == IP_RECVERR) ||
1179 		       (cm->cmsg_level == SOL_IPV6 && cm->cmsg_type == IPV6_RECVERR)))) {
1180 			SPDK_WARNLOG("Unexpected cmsg level or type!\n");
1181 			return 0;
1182 		}
1183 
1184 		serr = (struct sock_extended_err *)CMSG_DATA(cm);
1185 		if (serr->ee_errno != 0 || serr->ee_origin != SO_EE_ORIGIN_ZEROCOPY) {
1186 			SPDK_WARNLOG("Unexpected extended error origin\n");
1187 			return 0;
1188 		}
1189 
1190 		/* Most of the time, the pending_reqs array is in the exact
1191 		 * order we need such that all of the requests to complete are
1192 		 * in order, in the front. It is guaranteed that all requests
1193 		 * belonging to the same sendmsg call are sequential, so once
1194 		 * we encounter one match we can stop looping as soon as a
1195 		 * non-match is found.
1196 		 */
1197 		idx = serr->ee_info;
1198 		while (true) {
1199 			found = false;
1200 			TAILQ_FOREACH_SAFE(req, &sock->pending_reqs, internal.link, treq) {
1201 				if (!req->internal.is_zcopy) {
1202 					/* This wasn't a zcopy request. It was just waiting in line to complete */
1203 					rc = spdk_sock_request_put(sock, req, 0);
1204 					if (rc < 0) {
1205 						return rc;
1206 					}
1207 				} else if (req->internal.offset == idx) {
1208 					found = true;
1209 					rc = spdk_sock_request_put(sock, req, 0);
1210 					if (rc < 0) {
1211 						return rc;
1212 					}
1213 				} else if (found) {
1214 					break;
1215 				}
1216 			}
1217 
1218 			if (idx == serr->ee_data) {
1219 				break;
1220 			}
1221 
1222 			if (idx == UINT32_MAX) {
1223 				idx = 0;
1224 			} else {
1225 				idx++;
1226 			}
1227 		}
1228 	}
1229 
1230 	return 0;
1231 }
1232 #endif
1233 
1234 static int
1235 _sock_flush(struct spdk_sock *sock)
1236 {
1237 	struct spdk_posix_sock *psock = __posix_sock(sock);
1238 	struct msghdr msg = {};
1239 	int flags;
1240 	struct iovec iovs[IOV_BATCH_SIZE];
1241 	int iovcnt;
1242 	int retval;
1243 	struct spdk_sock_request *req;
1244 	int i;
1245 	ssize_t rc, sent;
1246 	unsigned int offset;
1247 	size_t len;
1248 	bool is_zcopy = false;
1249 
1250 	/* Can't flush from within a callback or we end up with recursive calls */
1251 	if (sock->cb_cnt > 0) {
1252 		errno = EAGAIN;
1253 		return -1;
1254 	}
1255 
1256 #ifdef SPDK_ZEROCOPY
1257 	if (psock->zcopy) {
1258 		flags = MSG_ZEROCOPY | MSG_NOSIGNAL;
1259 	} else
1260 #endif
1261 	{
1262 		flags = MSG_NOSIGNAL;
1263 	}
1264 
1265 	iovcnt = spdk_sock_prep_reqs(sock, iovs, 0, NULL, &flags);
1266 	if (iovcnt == 0) {
1267 		return 0;
1268 	}
1269 
1270 #ifdef SPDK_ZEROCOPY
1271 	is_zcopy = flags & MSG_ZEROCOPY;
1272 #endif
1273 
1274 	/* Perform the vectored write */
1275 	msg.msg_iov = iovs;
1276 	msg.msg_iovlen = iovcnt;
1277 
1278 	if (psock->ssl) {
1279 		rc = SSL_writev(psock->ssl, iovs, iovcnt);
1280 	} else {
1281 		rc = sendmsg(psock->fd, &msg, flags);
1282 	}
1283 	if (rc <= 0) {
1284 		if (rc == 0 || errno == EAGAIN || errno == EWOULDBLOCK || (errno == ENOBUFS && psock->zcopy)) {
1285 			errno = EAGAIN;
1286 		}
1287 		return -1;
1288 	}
1289 
1290 	sent = rc;
1291 
1292 	if (is_zcopy) {
1293 		/* Handling overflow case, because we use psock->sendmsg_idx - 1 for the
1294 		 * req->internal.offset, so sendmsg_idx should not be zero  */
1295 		if (spdk_unlikely(psock->sendmsg_idx == UINT32_MAX)) {
1296 			psock->sendmsg_idx = 1;
1297 		} else {
1298 			psock->sendmsg_idx++;
1299 		}
1300 	}
1301 
1302 	/* Consume the requests that were actually written */
1303 	req = TAILQ_FIRST(&sock->queued_reqs);
1304 	while (req) {
1305 		offset = req->internal.offset;
1306 
1307 		/* req->internal.is_zcopy is true when the whole req or part of it is sent with zerocopy */
1308 		req->internal.is_zcopy = is_zcopy;
1309 
1310 		for (i = 0; i < req->iovcnt; i++) {
1311 			/* Advance by the offset first */
1312 			if (offset >= SPDK_SOCK_REQUEST_IOV(req, i)->iov_len) {
1313 				offset -= SPDK_SOCK_REQUEST_IOV(req, i)->iov_len;
1314 				continue;
1315 			}
1316 
1317 			/* Calculate the remaining length of this element */
1318 			len = SPDK_SOCK_REQUEST_IOV(req, i)->iov_len - offset;
1319 
1320 			if (len > (size_t)rc) {
1321 				/* This element was partially sent. */
1322 				req->internal.offset += rc;
1323 				return sent;
1324 			}
1325 
1326 			offset = 0;
1327 			req->internal.offset += len;
1328 			rc -= len;
1329 		}
1330 
1331 		/* Handled a full request. */
1332 		spdk_sock_request_pend(sock, req);
1333 
1334 		if (!req->internal.is_zcopy && req == TAILQ_FIRST(&sock->pending_reqs)) {
1335 			/* The sendmsg syscall above isn't currently asynchronous,
1336 			* so it's already done. */
1337 			retval = spdk_sock_request_put(sock, req, 0);
1338 			if (retval) {
1339 				break;
1340 			}
1341 		} else {
1342 			/* Re-use the offset field to hold the sendmsg call index. The
1343 			 * index is 0 based, so subtract one here because we've already
1344 			 * incremented above. */
1345 			req->internal.offset = psock->sendmsg_idx - 1;
1346 		}
1347 
1348 		if (rc == 0) {
1349 			break;
1350 		}
1351 
1352 		req = TAILQ_FIRST(&sock->queued_reqs);
1353 	}
1354 
1355 	return sent;
1356 }
1357 
1358 static int
1359 posix_sock_flush(struct spdk_sock *sock)
1360 {
1361 #ifdef SPDK_ZEROCOPY
1362 	struct spdk_posix_sock *psock = __posix_sock(sock);
1363 
1364 	if (psock->zcopy && !TAILQ_EMPTY(&sock->pending_reqs)) {
1365 		_sock_check_zcopy(sock);
1366 	}
1367 #endif
1368 
1369 	return _sock_flush(sock);
1370 }
1371 
1372 static ssize_t
1373 posix_sock_recv_from_pipe(struct spdk_posix_sock *sock, struct iovec *diov, int diovcnt)
1374 {
1375 	struct iovec siov[2];
1376 	int sbytes;
1377 	ssize_t bytes;
1378 	struct spdk_posix_sock_group_impl *group;
1379 
1380 	sbytes = spdk_pipe_reader_get_buffer(sock->recv_pipe, sock->recv_buf_sz, siov);
1381 	if (sbytes < 0) {
1382 		errno = EINVAL;
1383 		return -1;
1384 	} else if (sbytes == 0) {
1385 		errno = EAGAIN;
1386 		return -1;
1387 	}
1388 
1389 	bytes = spdk_iovcpy(siov, 2, diov, diovcnt);
1390 
1391 	if (bytes == 0) {
1392 		/* The only way this happens is if diov is 0 length */
1393 		errno = EINVAL;
1394 		return -1;
1395 	}
1396 
1397 	spdk_pipe_reader_advance(sock->recv_pipe, bytes);
1398 
1399 	/* If we drained the pipe, mark it appropriately */
1400 	if (spdk_pipe_reader_bytes_available(sock->recv_pipe) == 0) {
1401 		assert(sock->pipe_has_data == true);
1402 
1403 		group = __posix_group_impl(sock->base.group_impl);
1404 		if (group && !sock->socket_has_data) {
1405 			TAILQ_REMOVE(&group->socks_with_data, sock, link);
1406 		}
1407 
1408 		sock->pipe_has_data = false;
1409 	}
1410 
1411 	return bytes;
1412 }
1413 
1414 static inline ssize_t
1415 posix_sock_read(struct spdk_posix_sock *sock)
1416 {
1417 	struct iovec iov[2];
1418 	int bytes_avail, bytes_recvd;
1419 	struct spdk_posix_sock_group_impl *group;
1420 
1421 	bytes_avail = spdk_pipe_writer_get_buffer(sock->recv_pipe, sock->recv_buf_sz, iov);
1422 
1423 	if (bytes_avail <= 0) {
1424 		return bytes_avail;
1425 	}
1426 
1427 	if (sock->ssl) {
1428 		bytes_recvd = SSL_readv(sock->ssl, iov, 2);
1429 	} else {
1430 		bytes_recvd = readv(sock->fd, iov, 2);
1431 	}
1432 
1433 	assert(sock->pipe_has_data == false);
1434 
1435 	if (bytes_recvd <= 0) {
1436 		/* Errors count as draining the socket data */
1437 		if (sock->base.group_impl && sock->socket_has_data) {
1438 			group = __posix_group_impl(sock->base.group_impl);
1439 			TAILQ_REMOVE(&group->socks_with_data, sock, link);
1440 		}
1441 
1442 		sock->socket_has_data = false;
1443 
1444 		return bytes_recvd;
1445 	}
1446 
1447 	spdk_pipe_writer_advance(sock->recv_pipe, bytes_recvd);
1448 
1449 #if DEBUG
1450 	if (sock->base.group_impl) {
1451 		assert(sock->socket_has_data == true);
1452 	}
1453 #endif
1454 
1455 	sock->pipe_has_data = true;
1456 	if (bytes_recvd < bytes_avail) {
1457 		/* We drained the kernel socket entirely. */
1458 		sock->socket_has_data = false;
1459 	}
1460 
1461 	return bytes_recvd;
1462 }
1463 
1464 static ssize_t
1465 posix_sock_readv(struct spdk_sock *_sock, struct iovec *iov, int iovcnt)
1466 {
1467 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1468 	struct spdk_posix_sock_group_impl *group = __posix_group_impl(sock->base.group_impl);
1469 	int rc, i;
1470 	size_t len;
1471 
1472 	if (sock->recv_pipe == NULL) {
1473 		assert(sock->pipe_has_data == false);
1474 		if (group && sock->socket_has_data) {
1475 			sock->socket_has_data = false;
1476 			TAILQ_REMOVE(&group->socks_with_data, sock, link);
1477 		}
1478 		if (sock->ssl) {
1479 			return SSL_readv(sock->ssl, iov, iovcnt);
1480 		} else {
1481 			return readv(sock->fd, iov, iovcnt);
1482 		}
1483 	}
1484 
1485 	/* If the socket is not in a group, we must assume it always has
1486 	 * data waiting for us because it is not epolled */
1487 	if (!sock->pipe_has_data && (group == NULL || sock->socket_has_data)) {
1488 		/* If the user is receiving a sufficiently large amount of data,
1489 		 * receive directly to their buffers. */
1490 		len = 0;
1491 		for (i = 0; i < iovcnt; i++) {
1492 			len += iov[i].iov_len;
1493 		}
1494 
1495 		if (len >= MIN_SOCK_PIPE_SIZE) {
1496 			/* TODO: Should this detect if kernel socket is drained? */
1497 			if (sock->ssl) {
1498 				return SSL_readv(sock->ssl, iov, iovcnt);
1499 			} else {
1500 				return readv(sock->fd, iov, iovcnt);
1501 			}
1502 		}
1503 
1504 		/* Otherwise, do a big read into our pipe */
1505 		rc = posix_sock_read(sock);
1506 		if (rc <= 0) {
1507 			return rc;
1508 		}
1509 	}
1510 
1511 	return posix_sock_recv_from_pipe(sock, iov, iovcnt);
1512 }
1513 
1514 static ssize_t
1515 posix_sock_recv(struct spdk_sock *sock, void *buf, size_t len)
1516 {
1517 	struct iovec iov[1];
1518 
1519 	iov[0].iov_base = buf;
1520 	iov[0].iov_len = len;
1521 
1522 	return posix_sock_readv(sock, iov, 1);
1523 }
1524 
1525 static void
1526 posix_sock_readv_async(struct spdk_sock *sock, struct spdk_sock_request *req)
1527 {
1528 	req->cb_fn(req->cb_arg, -ENOTSUP);
1529 }
1530 
1531 static ssize_t
1532 posix_sock_writev(struct spdk_sock *_sock, struct iovec *iov, int iovcnt)
1533 {
1534 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1535 	int rc;
1536 
1537 	/* In order to process a writev, we need to flush any asynchronous writes
1538 	 * first. */
1539 	rc = _sock_flush(_sock);
1540 	if (rc < 0) {
1541 		return rc;
1542 	}
1543 
1544 	if (!TAILQ_EMPTY(&_sock->queued_reqs)) {
1545 		/* We weren't able to flush all requests */
1546 		errno = EAGAIN;
1547 		return -1;
1548 	}
1549 
1550 	if (sock->ssl) {
1551 		return SSL_writev(sock->ssl, iov, iovcnt);
1552 	} else {
1553 		return writev(sock->fd, iov, iovcnt);
1554 	}
1555 }
1556 
1557 static int
1558 posix_sock_recv_next(struct spdk_sock *_sock, void **buf, void **ctx)
1559 {
1560 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1561 	struct iovec iov;
1562 	ssize_t rc;
1563 
1564 	if (sock->recv_pipe != NULL) {
1565 		errno = ENOTSUP;
1566 		return -1;
1567 	}
1568 
1569 	iov.iov_len = spdk_sock_group_get_buf(_sock->group_impl->group, &iov.iov_base, ctx);
1570 	if (iov.iov_len == 0) {
1571 		errno = ENOBUFS;
1572 		return -1;
1573 	}
1574 
1575 	rc = posix_sock_readv(_sock, &iov, 1);
1576 	if (rc <= 0) {
1577 		spdk_sock_group_provide_buf(_sock->group_impl->group, iov.iov_base, iov.iov_len, *ctx);
1578 		return rc;
1579 	}
1580 
1581 	*buf = iov.iov_base;
1582 
1583 	return rc;
1584 }
1585 
1586 static void
1587 posix_sock_writev_async(struct spdk_sock *sock, struct spdk_sock_request *req)
1588 {
1589 	int rc;
1590 
1591 	spdk_sock_request_queue(sock, req);
1592 
1593 	/* If there are a sufficient number queued, just flush them out immediately. */
1594 	if (sock->queued_iovcnt >= IOV_BATCH_SIZE) {
1595 		rc = _sock_flush(sock);
1596 		if (rc < 0 && errno != EAGAIN) {
1597 			spdk_sock_abort_requests(sock);
1598 		}
1599 	}
1600 }
1601 
1602 static int
1603 posix_sock_set_recvlowat(struct spdk_sock *_sock, int nbytes)
1604 {
1605 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1606 	int val;
1607 	int rc;
1608 
1609 	assert(sock != NULL);
1610 
1611 	val = nbytes;
1612 	rc = setsockopt(sock->fd, SOL_SOCKET, SO_RCVLOWAT, &val, sizeof val);
1613 	if (rc != 0) {
1614 		return -1;
1615 	}
1616 	return 0;
1617 }
1618 
1619 static bool
1620 posix_sock_is_ipv6(struct spdk_sock *_sock)
1621 {
1622 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1623 	struct sockaddr_storage sa;
1624 	socklen_t salen;
1625 	int rc;
1626 
1627 	assert(sock != NULL);
1628 
1629 	memset(&sa, 0, sizeof sa);
1630 	salen = sizeof sa;
1631 	rc = getsockname(sock->fd, (struct sockaddr *) &sa, &salen);
1632 	if (rc != 0) {
1633 		SPDK_ERRLOG("getsockname() failed (errno=%d)\n", errno);
1634 		return false;
1635 	}
1636 
1637 	return (sa.ss_family == AF_INET6);
1638 }
1639 
1640 static bool
1641 posix_sock_is_ipv4(struct spdk_sock *_sock)
1642 {
1643 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1644 	struct sockaddr_storage sa;
1645 	socklen_t salen;
1646 	int rc;
1647 
1648 	assert(sock != NULL);
1649 
1650 	memset(&sa, 0, sizeof sa);
1651 	salen = sizeof sa;
1652 	rc = getsockname(sock->fd, (struct sockaddr *) &sa, &salen);
1653 	if (rc != 0) {
1654 		SPDK_ERRLOG("getsockname() failed (errno=%d)\n", errno);
1655 		return false;
1656 	}
1657 
1658 	return (sa.ss_family == AF_INET);
1659 }
1660 
1661 static bool
1662 posix_sock_is_connected(struct spdk_sock *_sock)
1663 {
1664 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1665 	uint8_t byte;
1666 	int rc;
1667 
1668 	rc = recv(sock->fd, &byte, 1, MSG_PEEK);
1669 	if (rc == 0) {
1670 		return false;
1671 	}
1672 
1673 	if (rc < 0) {
1674 		if (errno == EAGAIN || errno == EWOULDBLOCK) {
1675 			return true;
1676 		}
1677 
1678 		return false;
1679 	}
1680 
1681 	return true;
1682 }
1683 
1684 static struct spdk_sock_group_impl *
1685 posix_sock_group_impl_get_optimal(struct spdk_sock *_sock, struct spdk_sock_group_impl *hint)
1686 {
1687 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1688 	struct spdk_sock_group_impl *group_impl;
1689 
1690 	if (sock->placement_id != -1) {
1691 		spdk_sock_map_lookup(&g_map, sock->placement_id, &group_impl, hint);
1692 		return group_impl;
1693 	}
1694 
1695 	return NULL;
1696 }
1697 
1698 static struct spdk_sock_group_impl *
1699 posix_sock_group_impl_create(void)
1700 {
1701 	struct spdk_posix_sock_group_impl *group_impl;
1702 	int fd;
1703 
1704 #if defined(SPDK_EPOLL)
1705 	fd = epoll_create1(0);
1706 #elif defined(SPDK_KEVENT)
1707 	fd = kqueue();
1708 #endif
1709 	if (fd == -1) {
1710 		return NULL;
1711 	}
1712 
1713 	group_impl = calloc(1, sizeof(*group_impl));
1714 	if (group_impl == NULL) {
1715 		SPDK_ERRLOG("group_impl allocation failed\n");
1716 		close(fd);
1717 		return NULL;
1718 	}
1719 
1720 	group_impl->fd = fd;
1721 	TAILQ_INIT(&group_impl->socks_with_data);
1722 	group_impl->placement_id = -1;
1723 
1724 	if (g_spdk_posix_sock_impl_opts.enable_placement_id == PLACEMENT_CPU) {
1725 		spdk_sock_map_insert(&g_map, spdk_env_get_current_core(), &group_impl->base);
1726 		group_impl->placement_id = spdk_env_get_current_core();
1727 	}
1728 
1729 	return &group_impl->base;
1730 }
1731 
1732 static void
1733 posix_sock_mark(struct spdk_posix_sock_group_impl *group, struct spdk_posix_sock *sock,
1734 		int placement_id)
1735 {
1736 #if defined(SO_MARK)
1737 	int rc;
1738 
1739 	rc = setsockopt(sock->fd, SOL_SOCKET, SO_MARK,
1740 			&placement_id, sizeof(placement_id));
1741 	if (rc != 0) {
1742 		/* Not fatal */
1743 		SPDK_ERRLOG("Error setting SO_MARK\n");
1744 		return;
1745 	}
1746 
1747 	rc = spdk_sock_map_insert(&g_map, placement_id, &group->base);
1748 	if (rc != 0) {
1749 		/* Not fatal */
1750 		SPDK_ERRLOG("Failed to insert sock group into map: %d\n", rc);
1751 		return;
1752 	}
1753 
1754 	sock->placement_id = placement_id;
1755 #endif
1756 }
1757 
1758 static void
1759 posix_sock_update_mark(struct spdk_sock_group_impl *_group, struct spdk_sock *_sock)
1760 {
1761 	struct spdk_posix_sock_group_impl *group = __posix_group_impl(_group);
1762 
1763 	if (group->placement_id == -1) {
1764 		group->placement_id = spdk_sock_map_find_free(&g_map);
1765 
1766 		/* If a free placement id is found, update existing sockets in this group */
1767 		if (group->placement_id != -1) {
1768 			struct spdk_sock  *sock, *tmp;
1769 
1770 			TAILQ_FOREACH_SAFE(sock, &_group->socks, link, tmp) {
1771 				posix_sock_mark(group, __posix_sock(sock), group->placement_id);
1772 			}
1773 		}
1774 	}
1775 
1776 	if (group->placement_id != -1) {
1777 		/*
1778 		 * group placement id is already determined for this poll group.
1779 		 * Mark socket with group's placement id.
1780 		 */
1781 		posix_sock_mark(group, __posix_sock(_sock), group->placement_id);
1782 	}
1783 }
1784 
1785 static int
1786 posix_sock_group_impl_add_sock(struct spdk_sock_group_impl *_group, struct spdk_sock *_sock)
1787 {
1788 	struct spdk_posix_sock_group_impl *group = __posix_group_impl(_group);
1789 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1790 	int rc;
1791 
1792 #if defined(SPDK_EPOLL)
1793 	struct epoll_event event;
1794 
1795 	memset(&event, 0, sizeof(event));
1796 	/* EPOLLERR is always on even if we don't set it, but be explicit for clarity */
1797 	event.events = EPOLLIN | EPOLLERR;
1798 	event.data.ptr = sock;
1799 
1800 	rc = epoll_ctl(group->fd, EPOLL_CTL_ADD, sock->fd, &event);
1801 #elif defined(SPDK_KEVENT)
1802 	struct kevent event;
1803 	struct timespec ts = {0};
1804 
1805 	EV_SET(&event, sock->fd, EVFILT_READ, EV_ADD, 0, 0, sock);
1806 
1807 	rc = kevent(group->fd, &event, 1, NULL, 0, &ts);
1808 #endif
1809 
1810 	if (rc != 0) {
1811 		return rc;
1812 	}
1813 
1814 	/* switched from another polling group due to scheduling */
1815 	if (spdk_unlikely(sock->recv_pipe != NULL  &&
1816 			  (spdk_pipe_reader_bytes_available(sock->recv_pipe) > 0))) {
1817 		sock->pipe_has_data = true;
1818 		sock->socket_has_data = false;
1819 		TAILQ_INSERT_TAIL(&group->socks_with_data, sock, link);
1820 	}
1821 
1822 	if (g_spdk_posix_sock_impl_opts.enable_placement_id == PLACEMENT_MARK) {
1823 		posix_sock_update_mark(_group, _sock);
1824 	} else if (sock->placement_id != -1) {
1825 		rc = spdk_sock_map_insert(&g_map, sock->placement_id, &group->base);
1826 		if (rc != 0) {
1827 			SPDK_ERRLOG("Failed to insert sock group into map: %d\n", rc);
1828 			/* Do not treat this as an error. The system will continue running. */
1829 		}
1830 	}
1831 
1832 	return rc;
1833 }
1834 
1835 static int
1836 posix_sock_group_impl_remove_sock(struct spdk_sock_group_impl *_group, struct spdk_sock *_sock)
1837 {
1838 	struct spdk_posix_sock_group_impl *group = __posix_group_impl(_group);
1839 	struct spdk_posix_sock *sock = __posix_sock(_sock);
1840 	int rc;
1841 
1842 	if (sock->pipe_has_data || sock->socket_has_data) {
1843 		TAILQ_REMOVE(&group->socks_with_data, sock, link);
1844 		sock->pipe_has_data = false;
1845 		sock->socket_has_data = false;
1846 	}
1847 
1848 	if (sock->placement_id != -1) {
1849 		spdk_sock_map_release(&g_map, sock->placement_id);
1850 	}
1851 
1852 #if defined(SPDK_EPOLL)
1853 	struct epoll_event event;
1854 
1855 	/* Event parameter is ignored but some old kernel version still require it. */
1856 	rc = epoll_ctl(group->fd, EPOLL_CTL_DEL, sock->fd, &event);
1857 #elif defined(SPDK_KEVENT)
1858 	struct kevent event;
1859 	struct timespec ts = {0};
1860 
1861 	EV_SET(&event, sock->fd, EVFILT_READ, EV_DELETE, 0, 0, NULL);
1862 
1863 	rc = kevent(group->fd, &event, 1, NULL, 0, &ts);
1864 	if (rc == 0 && event.flags & EV_ERROR) {
1865 		rc = -1;
1866 		errno = event.data;
1867 	}
1868 #endif
1869 
1870 	spdk_sock_abort_requests(_sock);
1871 
1872 	return rc;
1873 }
1874 
1875 static int
1876 posix_sock_group_impl_poll(struct spdk_sock_group_impl *_group, int max_events,
1877 			   struct spdk_sock **socks)
1878 {
1879 	struct spdk_posix_sock_group_impl *group = __posix_group_impl(_group);
1880 	struct spdk_sock *sock, *tmp;
1881 	int num_events, i, rc;
1882 	struct spdk_posix_sock *psock, *ptmp;
1883 #if defined(SPDK_EPOLL)
1884 	struct epoll_event events[MAX_EVENTS_PER_POLL];
1885 #elif defined(SPDK_KEVENT)
1886 	struct kevent events[MAX_EVENTS_PER_POLL];
1887 	struct timespec ts = {0};
1888 #endif
1889 
1890 #ifdef SPDK_ZEROCOPY
1891 	/* When all of the following conditions are met
1892 	 * - non-blocking socket
1893 	 * - zero copy is enabled
1894 	 * - interrupts suppressed (i.e. busy polling)
1895 	 * - the NIC tx queue is full at the time sendmsg() is called
1896 	 * - epoll_wait determines there is an EPOLLIN event for the socket
1897 	 * then we can get into a situation where data we've sent is queued
1898 	 * up in the kernel network stack, but interrupts have been suppressed
1899 	 * because other traffic is flowing so the kernel misses the signal
1900 	 * to flush the software tx queue. If there wasn't incoming data
1901 	 * pending on the socket, then epoll_wait would have been sufficient
1902 	 * to kick off the send operation, but since there is a pending event
1903 	 * epoll_wait does not trigger the necessary operation.
1904 	 *
1905 	 * We deal with this by checking for all of the above conditions and
1906 	 * additionally looking for EPOLLIN events that were not consumed from
1907 	 * the last poll loop. We take this to mean that the upper layer is
1908 	 * unable to consume them because it is blocked waiting for resources
1909 	 * to free up, and those resources are most likely freed in response
1910 	 * to a pending asynchronous write completing.
1911 	 *
1912 	 * Additionally, sockets that have the same placement_id actually share
1913 	 * an underlying hardware queue. That means polling one of them is
1914 	 * equivalent to polling all of them. As a quick mechanism to avoid
1915 	 * making extra poll() calls, stash the last placement_id during the loop
1916 	 * and only poll if it's not the same. The overwhelmingly common case
1917 	 * is that all sockets in this list have the same placement_id because
1918 	 * SPDK is intentionally grouping sockets by that value, so even
1919 	 * though this won't stop all extra calls to poll(), it's very fast
1920 	 * and will catch all of them in practice.
1921 	 */
1922 	int last_placement_id = -1;
1923 
1924 	TAILQ_FOREACH(psock, &group->socks_with_data, link) {
1925 		if (psock->zcopy && psock->placement_id >= 0 &&
1926 		    psock->placement_id != last_placement_id) {
1927 			struct pollfd pfd = {psock->fd, POLLIN | POLLERR, 0};
1928 
1929 			poll(&pfd, 1, 0);
1930 			last_placement_id = psock->placement_id;
1931 		}
1932 	}
1933 #endif
1934 
1935 	/* This must be a TAILQ_FOREACH_SAFE because while flushing,
1936 	 * a completion callback could remove the sock from the
1937 	 * group. */
1938 	TAILQ_FOREACH_SAFE(sock, &_group->socks, link, tmp) {
1939 		rc = _sock_flush(sock);
1940 		if (rc < 0 && errno != EAGAIN) {
1941 			spdk_sock_abort_requests(sock);
1942 		}
1943 	}
1944 
1945 	assert(max_events > 0);
1946 
1947 #if defined(SPDK_EPOLL)
1948 	num_events = epoll_wait(group->fd, events, max_events, 0);
1949 #elif defined(SPDK_KEVENT)
1950 	num_events = kevent(group->fd, NULL, 0, events, max_events, &ts);
1951 #endif
1952 
1953 	if (num_events == -1) {
1954 		return -1;
1955 	} else if (num_events == 0 && !TAILQ_EMPTY(&_group->socks)) {
1956 		sock = TAILQ_FIRST(&_group->socks);
1957 		psock = __posix_sock(sock);
1958 		/* poll() is called here to busy poll the queue associated with
1959 		 * first socket in list and potentially reap incoming data.
1960 		 */
1961 		if (sock->opts.priority) {
1962 			struct pollfd pfd = {0, 0, 0};
1963 
1964 			pfd.fd = psock->fd;
1965 			pfd.events = POLLIN | POLLERR;
1966 			poll(&pfd, 1, 0);
1967 		}
1968 	}
1969 
1970 	for (i = 0; i < num_events; i++) {
1971 #if defined(SPDK_EPOLL)
1972 		sock = events[i].data.ptr;
1973 		psock = __posix_sock(sock);
1974 
1975 #ifdef SPDK_ZEROCOPY
1976 		if (events[i].events & EPOLLERR) {
1977 			rc = _sock_check_zcopy(sock);
1978 			/* If the socket was closed or removed from
1979 			 * the group in response to a send ack, don't
1980 			 * add it to the array here. */
1981 			if (rc || sock->cb_fn == NULL) {
1982 				continue;
1983 			}
1984 		}
1985 #endif
1986 		if ((events[i].events & EPOLLIN) == 0) {
1987 			continue;
1988 		}
1989 
1990 #elif defined(SPDK_KEVENT)
1991 		sock = events[i].udata;
1992 		psock = __posix_sock(sock);
1993 #endif
1994 
1995 		/* If the socket is not already in the list, add it now */
1996 		if (!psock->socket_has_data && !psock->pipe_has_data) {
1997 			TAILQ_INSERT_TAIL(&group->socks_with_data, psock, link);
1998 		}
1999 		psock->socket_has_data = true;
2000 	}
2001 
2002 	num_events = 0;
2003 
2004 	TAILQ_FOREACH_SAFE(psock, &group->socks_with_data, link, ptmp) {
2005 		if (num_events == max_events) {
2006 			break;
2007 		}
2008 
2009 		/* If the socket's cb_fn is NULL, just remove it from the
2010 		 * list and do not add it to socks array */
2011 		if (spdk_unlikely(psock->base.cb_fn == NULL)) {
2012 			psock->socket_has_data = false;
2013 			psock->pipe_has_data = false;
2014 			TAILQ_REMOVE(&group->socks_with_data, psock, link);
2015 			continue;
2016 		}
2017 
2018 		socks[num_events++] = &psock->base;
2019 	}
2020 
2021 	/* Cycle the has_data list so that each time we poll things aren't
2022 	 * in the same order. Say we have 6 sockets in the list, named as follows:
2023 	 * A B C D E F
2024 	 * And all 6 sockets had epoll events, but max_events is only 3. That means
2025 	 * psock currently points at D. We want to rearrange the list to the following:
2026 	 * D E F A B C
2027 	 *
2028 	 * The variables below are named according to this example to make it easier to
2029 	 * follow the swaps.
2030 	 */
2031 	if (psock != NULL) {
2032 		struct spdk_posix_sock *pa, *pc, *pd, *pf;
2033 
2034 		/* Capture pointers to the elements we need */
2035 		pd = psock;
2036 		pc = TAILQ_PREV(pd, spdk_has_data_list, link);
2037 		pa = TAILQ_FIRST(&group->socks_with_data);
2038 		pf = TAILQ_LAST(&group->socks_with_data, spdk_has_data_list);
2039 
2040 		/* Break the link between C and D */
2041 		pc->link.tqe_next = NULL;
2042 
2043 		/* Connect F to A */
2044 		pf->link.tqe_next = pa;
2045 		pa->link.tqe_prev = &pf->link.tqe_next;
2046 
2047 		/* Fix up the list first/last pointers */
2048 		group->socks_with_data.tqh_first = pd;
2049 		group->socks_with_data.tqh_last = &pc->link.tqe_next;
2050 
2051 		/* D is in front of the list, make tqe prev pointer point to the head of list */
2052 		pd->link.tqe_prev = &group->socks_with_data.tqh_first;
2053 	}
2054 
2055 	return num_events;
2056 }
2057 
2058 static int
2059 posix_sock_group_impl_close(struct spdk_sock_group_impl *_group)
2060 {
2061 	struct spdk_posix_sock_group_impl *group = __posix_group_impl(_group);
2062 	int rc;
2063 
2064 	if (g_spdk_posix_sock_impl_opts.enable_placement_id == PLACEMENT_CPU) {
2065 		spdk_sock_map_release(&g_map, spdk_env_get_current_core());
2066 	}
2067 
2068 	rc = close(group->fd);
2069 	free(group);
2070 	return rc;
2071 }
2072 
2073 static struct spdk_net_impl g_posix_net_impl = {
2074 	.name		= "posix",
2075 	.getaddr	= posix_sock_getaddr,
2076 	.connect	= posix_sock_connect,
2077 	.listen		= posix_sock_listen,
2078 	.accept		= posix_sock_accept,
2079 	.close		= posix_sock_close,
2080 	.recv		= posix_sock_recv,
2081 	.readv		= posix_sock_readv,
2082 	.readv_async	= posix_sock_readv_async,
2083 	.writev		= posix_sock_writev,
2084 	.recv_next	= posix_sock_recv_next,
2085 	.writev_async	= posix_sock_writev_async,
2086 	.flush		= posix_sock_flush,
2087 	.set_recvlowat	= posix_sock_set_recvlowat,
2088 	.set_recvbuf	= posix_sock_set_recvbuf,
2089 	.set_sendbuf	= posix_sock_set_sendbuf,
2090 	.is_ipv6	= posix_sock_is_ipv6,
2091 	.is_ipv4	= posix_sock_is_ipv4,
2092 	.is_connected	= posix_sock_is_connected,
2093 	.group_impl_get_optimal	= posix_sock_group_impl_get_optimal,
2094 	.group_impl_create	= posix_sock_group_impl_create,
2095 	.group_impl_add_sock	= posix_sock_group_impl_add_sock,
2096 	.group_impl_remove_sock = posix_sock_group_impl_remove_sock,
2097 	.group_impl_poll	= posix_sock_group_impl_poll,
2098 	.group_impl_close	= posix_sock_group_impl_close,
2099 	.get_opts	= posix_sock_impl_get_opts,
2100 	.set_opts	= posix_sock_impl_set_opts,
2101 };
2102 
2103 SPDK_NET_IMPL_REGISTER(posix, &g_posix_net_impl, DEFAULT_SOCK_PRIORITY + 1);
2104 
2105 static struct spdk_sock *
2106 ssl_sock_listen(const char *ip, int port, struct spdk_sock_opts *opts)
2107 {
2108 	return posix_sock_create(ip, port, SPDK_SOCK_CREATE_LISTEN, opts, true);
2109 }
2110 
2111 static struct spdk_sock *
2112 ssl_sock_connect(const char *ip, int port, struct spdk_sock_opts *opts)
2113 {
2114 	return posix_sock_create(ip, port, SPDK_SOCK_CREATE_CONNECT, opts, true);
2115 }
2116 
2117 static struct spdk_sock *
2118 ssl_sock_accept(struct spdk_sock *_sock)
2119 {
2120 	return _posix_sock_accept(_sock, true);
2121 }
2122 
2123 static struct spdk_net_impl g_ssl_net_impl = {
2124 	.name		= "ssl",
2125 	.getaddr	= posix_sock_getaddr,
2126 	.connect	= ssl_sock_connect,
2127 	.listen		= ssl_sock_listen,
2128 	.accept		= ssl_sock_accept,
2129 	.close		= posix_sock_close,
2130 	.recv		= posix_sock_recv,
2131 	.readv		= posix_sock_readv,
2132 	.writev		= posix_sock_writev,
2133 	.recv_next	= posix_sock_recv_next,
2134 	.writev_async	= posix_sock_writev_async,
2135 	.flush		= posix_sock_flush,
2136 	.set_recvlowat	= posix_sock_set_recvlowat,
2137 	.set_recvbuf	= posix_sock_set_recvbuf,
2138 	.set_sendbuf	= posix_sock_set_sendbuf,
2139 	.is_ipv6	= posix_sock_is_ipv6,
2140 	.is_ipv4	= posix_sock_is_ipv4,
2141 	.is_connected	= posix_sock_is_connected,
2142 	.group_impl_get_optimal	= posix_sock_group_impl_get_optimal,
2143 	.group_impl_create	= posix_sock_group_impl_create,
2144 	.group_impl_add_sock	= posix_sock_group_impl_add_sock,
2145 	.group_impl_remove_sock = posix_sock_group_impl_remove_sock,
2146 	.group_impl_poll	= posix_sock_group_impl_poll,
2147 	.group_impl_close	= posix_sock_group_impl_close,
2148 	.get_opts	= posix_sock_impl_get_opts,
2149 	.set_opts	= posix_sock_impl_set_opts,
2150 };
2151 
2152 SPDK_NET_IMPL_REGISTER(ssl, &g_ssl_net_impl, DEFAULT_SOCK_PRIORITY);
2153 SPDK_LOG_REGISTER_COMPONENT(sock_posix)
2154