xref: /freebsd/sys/kern/uipc_ktls.c (revision f6a3b357e9be4c6423c85eff9a847163a0d307c8)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2014-2019 Netflix Inc.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include "opt_inet.h"
32 #include "opt_inet6.h"
33 #include "opt_rss.h"
34 
35 #include <sys/param.h>
36 #include <sys/kernel.h>
37 #include <sys/ktls.h>
38 #include <sys/lock.h>
39 #include <sys/mbuf.h>
40 #include <sys/mutex.h>
41 #include <sys/rmlock.h>
42 #include <sys/proc.h>
43 #include <sys/protosw.h>
44 #include <sys/refcount.h>
45 #include <sys/smp.h>
46 #include <sys/socket.h>
47 #include <sys/socketvar.h>
48 #include <sys/sysctl.h>
49 #include <sys/taskqueue.h>
50 #include <sys/kthread.h>
51 #include <sys/uio.h>
52 #include <sys/vmmeter.h>
53 #if defined(__aarch64__) || defined(__amd64__) || defined(__i386__)
54 #include <machine/pcb.h>
55 #endif
56 #include <machine/vmparam.h>
57 #ifdef RSS
58 #include <net/netisr.h>
59 #include <net/rss_config.h>
60 #endif
61 #if defined(INET) || defined(INET6)
62 #include <netinet/in.h>
63 #include <netinet/in_pcb.h>
64 #endif
65 #include <netinet/tcp_var.h>
66 #include <opencrypto/xform.h>
67 #include <vm/uma_dbg.h>
68 #include <vm/vm.h>
69 #include <vm/vm_pageout.h>
70 #include <vm/vm_page.h>
71 
72 struct ktls_wq {
73 	struct mtx	mtx;
74 	STAILQ_HEAD(, mbuf_ext_pgs) head;
75 	bool		running;
76 } __aligned(CACHE_LINE_SIZE);
77 
78 static struct ktls_wq *ktls_wq;
79 static struct proc *ktls_proc;
80 LIST_HEAD(, ktls_crypto_backend) ktls_backends;
81 static struct rmlock ktls_backends_lock;
82 static uma_zone_t ktls_session_zone;
83 static uint16_t ktls_cpuid_lookup[MAXCPU];
84 
85 SYSCTL_NODE(_kern_ipc, OID_AUTO, tls, CTLFLAG_RW, 0,
86     "Kernel TLS offload");
87 SYSCTL_NODE(_kern_ipc_tls, OID_AUTO, stats, CTLFLAG_RW, 0,
88     "Kernel TLS offload stats");
89 
90 static int ktls_allow_unload;
91 SYSCTL_INT(_kern_ipc_tls, OID_AUTO, allow_unload, CTLFLAG_RDTUN,
92     &ktls_allow_unload, 0, "Allow software crypto modules to unload");
93 
94 #ifdef RSS
95 static int ktls_bind_threads = 1;
96 #else
97 static int ktls_bind_threads;
98 #endif
99 SYSCTL_INT(_kern_ipc_tls, OID_AUTO, bind_threads, CTLFLAG_RDTUN,
100     &ktls_bind_threads, 0,
101     "Bind crypto threads to cores or domains at boot");
102 
103 static u_int ktls_maxlen = 16384;
104 SYSCTL_UINT(_kern_ipc_tls, OID_AUTO, maxlen, CTLFLAG_RWTUN,
105     &ktls_maxlen, 0, "Maximum TLS record size");
106 
107 static int ktls_number_threads;
108 SYSCTL_INT(_kern_ipc_tls_stats, OID_AUTO, threads, CTLFLAG_RD,
109     &ktls_number_threads, 0,
110     "Number of TLS threads in thread-pool");
111 
112 static bool ktls_offload_enable;
113 SYSCTL_BOOL(_kern_ipc_tls, OID_AUTO, enable, CTLFLAG_RW,
114     &ktls_offload_enable, 0,
115     "Enable support for kernel TLS offload");
116 
117 static bool ktls_cbc_enable = true;
118 SYSCTL_BOOL(_kern_ipc_tls, OID_AUTO, cbc_enable, CTLFLAG_RW,
119     &ktls_cbc_enable, 1,
120     "Enable Support of AES-CBC crypto for kernel TLS");
121 
122 static counter_u64_t ktls_tasks_active;
123 SYSCTL_COUNTER_U64(_kern_ipc_tls, OID_AUTO, tasks_active, CTLFLAG_RD,
124     &ktls_tasks_active, "Number of active tasks");
125 
126 static counter_u64_t ktls_cnt_on;
127 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats, OID_AUTO, so_inqueue, CTLFLAG_RD,
128     &ktls_cnt_on, "Number of TLS records in queue to tasks for SW crypto");
129 
130 static counter_u64_t ktls_offload_total;
131 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats, OID_AUTO, offload_total,
132     CTLFLAG_RD, &ktls_offload_total,
133     "Total successful TLS setups (parameters set)");
134 
135 static counter_u64_t ktls_offload_enable_calls;
136 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats, OID_AUTO, enable_calls,
137     CTLFLAG_RD, &ktls_offload_enable_calls,
138     "Total number of TLS enable calls made");
139 
140 static counter_u64_t ktls_offload_active;
141 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats, OID_AUTO, active, CTLFLAG_RD,
142     &ktls_offload_active, "Total Active TLS sessions");
143 
144 static counter_u64_t ktls_offload_failed_crypto;
145 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats, OID_AUTO, failed_crypto, CTLFLAG_RD,
146     &ktls_offload_failed_crypto, "Total TLS crypto failures");
147 
148 static counter_u64_t ktls_switch_to_ifnet;
149 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats, OID_AUTO, switch_to_ifnet, CTLFLAG_RD,
150     &ktls_switch_to_ifnet, "TLS sessions switched from SW to ifnet");
151 
152 static counter_u64_t ktls_switch_to_sw;
153 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats, OID_AUTO, switch_to_sw, CTLFLAG_RD,
154     &ktls_switch_to_sw, "TLS sessions switched from ifnet to SW");
155 
156 static counter_u64_t ktls_switch_failed;
157 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats, OID_AUTO, switch_failed, CTLFLAG_RD,
158     &ktls_switch_failed, "TLS sessions unable to switch between SW and ifnet");
159 
160 SYSCTL_NODE(_kern_ipc_tls, OID_AUTO, sw, CTLFLAG_RD, 0,
161     "Software TLS session stats");
162 SYSCTL_NODE(_kern_ipc_tls, OID_AUTO, ifnet, CTLFLAG_RD, 0,
163     "Hardware (ifnet) TLS session stats");
164 
165 static counter_u64_t ktls_sw_cbc;
166 SYSCTL_COUNTER_U64(_kern_ipc_tls_sw, OID_AUTO, cbc, CTLFLAG_RD, &ktls_sw_cbc,
167     "Active number of software TLS sessions using AES-CBC");
168 
169 static counter_u64_t ktls_sw_gcm;
170 SYSCTL_COUNTER_U64(_kern_ipc_tls_sw, OID_AUTO, gcm, CTLFLAG_RD, &ktls_sw_gcm,
171     "Active number of software TLS sessions using AES-GCM");
172 
173 static counter_u64_t ktls_ifnet_cbc;
174 SYSCTL_COUNTER_U64(_kern_ipc_tls_ifnet, OID_AUTO, cbc, CTLFLAG_RD,
175     &ktls_ifnet_cbc,
176     "Active number of ifnet TLS sessions using AES-CBC");
177 
178 static counter_u64_t ktls_ifnet_gcm;
179 SYSCTL_COUNTER_U64(_kern_ipc_tls_ifnet, OID_AUTO, gcm, CTLFLAG_RD,
180     &ktls_ifnet_gcm,
181     "Active number of ifnet TLS sessions using AES-GCM");
182 
183 static counter_u64_t ktls_ifnet_reset;
184 SYSCTL_COUNTER_U64(_kern_ipc_tls_ifnet, OID_AUTO, reset, CTLFLAG_RD,
185     &ktls_ifnet_reset, "TLS sessions updated to a new ifnet send tag");
186 
187 static counter_u64_t ktls_ifnet_reset_dropped;
188 SYSCTL_COUNTER_U64(_kern_ipc_tls_ifnet, OID_AUTO, reset_dropped, CTLFLAG_RD,
189     &ktls_ifnet_reset_dropped,
190     "TLS sessions dropped after failing to update ifnet send tag");
191 
192 static counter_u64_t ktls_ifnet_reset_failed;
193 SYSCTL_COUNTER_U64(_kern_ipc_tls_ifnet, OID_AUTO, reset_failed, CTLFLAG_RD,
194     &ktls_ifnet_reset_failed,
195     "TLS sessions that failed to allocate a new ifnet send tag");
196 
197 static int ktls_ifnet_permitted;
198 SYSCTL_UINT(_kern_ipc_tls_ifnet, OID_AUTO, permitted, CTLFLAG_RWTUN,
199     &ktls_ifnet_permitted, 1,
200     "Whether to permit hardware (ifnet) TLS sessions");
201 
202 static MALLOC_DEFINE(M_KTLS, "ktls", "Kernel TLS");
203 
204 static void ktls_cleanup(struct ktls_session *tls);
205 #if defined(INET) || defined(INET6)
206 static void ktls_reset_send_tag(void *context, int pending);
207 #endif
208 static void ktls_work_thread(void *ctx);
209 
210 int
211 ktls_crypto_backend_register(struct ktls_crypto_backend *be)
212 {
213 	struct ktls_crypto_backend *curr_be, *tmp;
214 
215 	if (be->api_version != KTLS_API_VERSION) {
216 		printf("KTLS: API version mismatch (%d vs %d) for %s\n",
217 		    be->api_version, KTLS_API_VERSION,
218 		    be->name);
219 		return (EINVAL);
220 	}
221 
222 	rm_wlock(&ktls_backends_lock);
223 	printf("KTLS: Registering crypto method %s with prio %d\n",
224 	       be->name, be->prio);
225 	if (LIST_EMPTY(&ktls_backends)) {
226 		LIST_INSERT_HEAD(&ktls_backends, be, next);
227 	} else {
228 		LIST_FOREACH_SAFE(curr_be, &ktls_backends, next, tmp) {
229 			if (curr_be->prio < be->prio) {
230 				LIST_INSERT_BEFORE(curr_be, be, next);
231 				break;
232 			}
233 			if (LIST_NEXT(curr_be, next) == NULL) {
234 				LIST_INSERT_AFTER(curr_be, be, next);
235 				break;
236 			}
237 		}
238 	}
239 	rm_wunlock(&ktls_backends_lock);
240 	return (0);
241 }
242 
243 int
244 ktls_crypto_backend_deregister(struct ktls_crypto_backend *be)
245 {
246 	struct ktls_crypto_backend *tmp;
247 
248 	/*
249 	 * Don't error if the backend isn't registered.  This permits
250 	 * MOD_UNLOAD handlers to use this function unconditionally.
251 	 */
252 	rm_wlock(&ktls_backends_lock);
253 	LIST_FOREACH(tmp, &ktls_backends, next) {
254 		if (tmp == be)
255 			break;
256 	}
257 	if (tmp == NULL) {
258 		rm_wunlock(&ktls_backends_lock);
259 		return (0);
260 	}
261 
262 	if (!ktls_allow_unload) {
263 		rm_wunlock(&ktls_backends_lock);
264 		printf(
265 		    "KTLS: Deregistering crypto method %s is not supported\n",
266 		    be->name);
267 		return (EBUSY);
268 	}
269 
270 	if (be->use_count) {
271 		rm_wunlock(&ktls_backends_lock);
272 		return (EBUSY);
273 	}
274 
275 	LIST_REMOVE(be, next);
276 	rm_wunlock(&ktls_backends_lock);
277 	return (0);
278 }
279 
280 #if defined(INET) || defined(INET6)
281 static uint16_t
282 ktls_get_cpu(struct socket *so)
283 {
284 	struct inpcb *inp;
285 	uint16_t cpuid;
286 
287 	inp = sotoinpcb(so);
288 #ifdef RSS
289 	cpuid = rss_hash2cpuid(inp->inp_flowid, inp->inp_flowtype);
290 	if (cpuid != NETISR_CPUID_NONE)
291 		return (cpuid);
292 #endif
293 	/*
294 	 * Just use the flowid to shard connections in a repeatable
295 	 * fashion.  Note that some crypto backends rely on the
296 	 * serialization provided by having the same connection use
297 	 * the same queue.
298 	 */
299 	cpuid = ktls_cpuid_lookup[inp->inp_flowid % ktls_number_threads];
300 	return (cpuid);
301 }
302 #endif
303 
304 static void
305 ktls_init(void *dummy __unused)
306 {
307 	struct thread *td;
308 	struct pcpu *pc;
309 	cpuset_t mask;
310 	int error, i;
311 
312 	ktls_tasks_active = counter_u64_alloc(M_WAITOK);
313 	ktls_cnt_on = counter_u64_alloc(M_WAITOK);
314 	ktls_offload_total = counter_u64_alloc(M_WAITOK);
315 	ktls_offload_enable_calls = counter_u64_alloc(M_WAITOK);
316 	ktls_offload_active = counter_u64_alloc(M_WAITOK);
317 	ktls_offload_failed_crypto = counter_u64_alloc(M_WAITOK);
318 	ktls_switch_to_ifnet = counter_u64_alloc(M_WAITOK);
319 	ktls_switch_to_sw = counter_u64_alloc(M_WAITOK);
320 	ktls_switch_failed = counter_u64_alloc(M_WAITOK);
321 	ktls_sw_cbc = counter_u64_alloc(M_WAITOK);
322 	ktls_sw_gcm = counter_u64_alloc(M_WAITOK);
323 	ktls_ifnet_cbc = counter_u64_alloc(M_WAITOK);
324 	ktls_ifnet_gcm = counter_u64_alloc(M_WAITOK);
325 	ktls_ifnet_reset = counter_u64_alloc(M_WAITOK);
326 	ktls_ifnet_reset_dropped = counter_u64_alloc(M_WAITOK);
327 	ktls_ifnet_reset_failed = counter_u64_alloc(M_WAITOK);
328 
329 	rm_init(&ktls_backends_lock, "ktls backends");
330 	LIST_INIT(&ktls_backends);
331 
332 	ktls_wq = malloc(sizeof(*ktls_wq) * (mp_maxid + 1), M_KTLS,
333 	    M_WAITOK | M_ZERO);
334 
335 	ktls_session_zone = uma_zcreate("ktls_session",
336 	    sizeof(struct ktls_session),
337 #ifdef INVARIANTS
338 	    trash_ctor, trash_dtor, trash_init, trash_fini,
339 #else
340 	    NULL, NULL, NULL, NULL,
341 #endif
342 	    UMA_ALIGN_CACHE, 0);
343 
344 	/*
345 	 * Initialize the workqueues to run the TLS work.  We create a
346 	 * work queue for each CPU.
347 	 */
348 	CPU_FOREACH(i) {
349 		STAILQ_INIT(&ktls_wq[i].head);
350 		mtx_init(&ktls_wq[i].mtx, "ktls work queue", NULL, MTX_DEF);
351 		error = kproc_kthread_add(ktls_work_thread, &ktls_wq[i],
352 		    &ktls_proc, &td, 0, 0, "KTLS", "ktls_thr_%d", i);
353 		if (error)
354 			panic("Can't add KTLS thread %d error %d", i, error);
355 
356 		/*
357 		 * Bind threads to cores.  If ktls_bind_threads is >
358 		 * 1, then we bind to the NUMA domain.
359 		 */
360 		if (ktls_bind_threads) {
361 			if (ktls_bind_threads > 1) {
362 				pc = pcpu_find(i);
363 				CPU_COPY(&cpuset_domain[pc->pc_domain], &mask);
364 			} else {
365 				CPU_SETOF(i, &mask);
366 			}
367 			error = cpuset_setthread(td->td_tid, &mask);
368 			if (error)
369 				panic(
370 			    "Unable to bind KTLS thread for CPU %d error %d",
371 				     i, error);
372 		}
373 		ktls_cpuid_lookup[ktls_number_threads] = i;
374 		ktls_number_threads++;
375 	}
376 	printf("KTLS: Initialized %d threads\n", ktls_number_threads);
377 }
378 SYSINIT(ktls, SI_SUB_SMP + 1, SI_ORDER_ANY, ktls_init, NULL);
379 
380 #if defined(INET) || defined(INET6)
381 static int
382 ktls_create_session(struct socket *so, struct tls_enable *en,
383     struct ktls_session **tlsp)
384 {
385 	struct ktls_session *tls;
386 	int error;
387 
388 	/* Only TLS 1.0 - 1.2 are supported. */
389 	if (en->tls_vmajor != TLS_MAJOR_VER_ONE)
390 		return (EINVAL);
391 	if (en->tls_vminor < TLS_MINOR_VER_ZERO ||
392 	    en->tls_vminor > TLS_MINOR_VER_TWO)
393 		return (EINVAL);
394 
395 	if (en->auth_key_len < 0 || en->auth_key_len > TLS_MAX_PARAM_SIZE)
396 		return (EINVAL);
397 	if (en->cipher_key_len < 0 || en->cipher_key_len > TLS_MAX_PARAM_SIZE)
398 		return (EINVAL);
399 	if (en->iv_len < 0 || en->iv_len > TLS_MAX_PARAM_SIZE)
400 		return (EINVAL);
401 
402 	/* All supported algorithms require a cipher key. */
403 	if (en->cipher_key_len == 0)
404 		return (EINVAL);
405 
406 	/* No flags are currently supported. */
407 	if (en->flags != 0)
408 		return (EINVAL);
409 
410 	/* Common checks for supported algorithms. */
411 	switch (en->cipher_algorithm) {
412 	case CRYPTO_AES_NIST_GCM_16:
413 		/*
414 		 * auth_algorithm isn't used, but permit GMAC values
415 		 * for compatibility.
416 		 */
417 		switch (en->auth_algorithm) {
418 		case 0:
419 		case CRYPTO_AES_128_NIST_GMAC:
420 		case CRYPTO_AES_192_NIST_GMAC:
421 		case CRYPTO_AES_256_NIST_GMAC:
422 			break;
423 		default:
424 			return (EINVAL);
425 		}
426 		if (en->auth_key_len != 0)
427 			return (EINVAL);
428 		if (en->iv_len != TLS_AEAD_GCM_LEN)
429 			return (EINVAL);
430 		break;
431 	case CRYPTO_AES_CBC:
432 		switch (en->auth_algorithm) {
433 		case CRYPTO_SHA1_HMAC:
434 			/*
435 			 * TLS 1.0 requires an implicit IV.  TLS 1.1+
436 			 * all use explicit IVs.
437 			 */
438 			if (en->tls_vminor == TLS_MINOR_VER_ZERO) {
439 				if (en->iv_len != TLS_CBC_IMPLICIT_IV_LEN)
440 					return (EINVAL);
441 				break;
442 			}
443 
444 			/* FALLTHROUGH */
445 		case CRYPTO_SHA2_256_HMAC:
446 		case CRYPTO_SHA2_384_HMAC:
447 			/* Ignore any supplied IV. */
448 			en->iv_len = 0;
449 			break;
450 		default:
451 			return (EINVAL);
452 		}
453 		if (en->auth_key_len == 0)
454 			return (EINVAL);
455 		break;
456 	default:
457 		return (EINVAL);
458 	}
459 
460 	tls = uma_zalloc(ktls_session_zone, M_WAITOK | M_ZERO);
461 
462 	counter_u64_add(ktls_offload_active, 1);
463 
464 	refcount_init(&tls->refcount, 1);
465 	TASK_INIT(&tls->reset_tag_task, 0, ktls_reset_send_tag, tls);
466 
467 	tls->wq_index = ktls_get_cpu(so);
468 
469 	tls->params.cipher_algorithm = en->cipher_algorithm;
470 	tls->params.auth_algorithm = en->auth_algorithm;
471 	tls->params.tls_vmajor = en->tls_vmajor;
472 	tls->params.tls_vminor = en->tls_vminor;
473 	tls->params.flags = en->flags;
474 	tls->params.max_frame_len = min(TLS_MAX_MSG_SIZE_V10_2, ktls_maxlen);
475 
476 	/* Set the header and trailer lengths. */
477 	tls->params.tls_hlen = sizeof(struct tls_record_layer);
478 	switch (en->cipher_algorithm) {
479 	case CRYPTO_AES_NIST_GCM_16:
480 		tls->params.tls_hlen += 8;
481 		tls->params.tls_tlen = AES_GMAC_HASH_LEN;
482 		tls->params.tls_bs = 1;
483 		break;
484 	case CRYPTO_AES_CBC:
485 		switch (en->auth_algorithm) {
486 		case CRYPTO_SHA1_HMAC:
487 			if (en->tls_vminor == TLS_MINOR_VER_ZERO) {
488 				/* Implicit IV, no nonce. */
489 			} else {
490 				tls->params.tls_hlen += AES_BLOCK_LEN;
491 			}
492 			tls->params.tls_tlen = AES_BLOCK_LEN +
493 			    SHA1_HASH_LEN;
494 			break;
495 		case CRYPTO_SHA2_256_HMAC:
496 			tls->params.tls_hlen += AES_BLOCK_LEN;
497 			tls->params.tls_tlen = AES_BLOCK_LEN +
498 			    SHA2_256_HASH_LEN;
499 			break;
500 		case CRYPTO_SHA2_384_HMAC:
501 			tls->params.tls_hlen += AES_BLOCK_LEN;
502 			tls->params.tls_tlen = AES_BLOCK_LEN +
503 			    SHA2_384_HASH_LEN;
504 			break;
505 		default:
506 			panic("invalid hmac");
507 		}
508 		tls->params.tls_bs = AES_BLOCK_LEN;
509 		break;
510 	default:
511 		panic("invalid cipher");
512 	}
513 
514 	KASSERT(tls->params.tls_hlen <= MBUF_PEXT_HDR_LEN,
515 	    ("TLS header length too long: %d", tls->params.tls_hlen));
516 	KASSERT(tls->params.tls_tlen <= MBUF_PEXT_TRAIL_LEN,
517 	    ("TLS trailer length too long: %d", tls->params.tls_tlen));
518 
519 	if (en->auth_key_len != 0) {
520 		tls->params.auth_key_len = en->auth_key_len;
521 		tls->params.auth_key = malloc(en->auth_key_len, M_KTLS,
522 		    M_WAITOK);
523 		error = copyin(en->auth_key, tls->params.auth_key,
524 		    en->auth_key_len);
525 		if (error)
526 			goto out;
527 	}
528 
529 	tls->params.cipher_key_len = en->cipher_key_len;
530 	tls->params.cipher_key = malloc(en->cipher_key_len, M_KTLS, M_WAITOK);
531 	error = copyin(en->cipher_key, tls->params.cipher_key,
532 	    en->cipher_key_len);
533 	if (error)
534 		goto out;
535 
536 	/*
537 	 * This holds the implicit portion of the nonce for GCM and
538 	 * the initial implicit IV for TLS 1.0.  The explicit portions
539 	 * of the IV are generated in ktls_frame() and ktls_seq().
540 	 */
541 	if (en->iv_len != 0) {
542 		MPASS(en->iv_len <= sizeof(tls->params.iv));
543 		tls->params.iv_len = en->iv_len;
544 		error = copyin(en->iv, tls->params.iv, en->iv_len);
545 		if (error)
546 			goto out;
547 	}
548 
549 	*tlsp = tls;
550 	return (0);
551 
552 out:
553 	ktls_cleanup(tls);
554 	return (error);
555 }
556 
557 static struct ktls_session *
558 ktls_clone_session(struct ktls_session *tls)
559 {
560 	struct ktls_session *tls_new;
561 
562 	tls_new = uma_zalloc(ktls_session_zone, M_WAITOK | M_ZERO);
563 
564 	counter_u64_add(ktls_offload_active, 1);
565 
566 	refcount_init(&tls_new->refcount, 1);
567 
568 	/* Copy fields from existing session. */
569 	tls_new->params = tls->params;
570 	tls_new->wq_index = tls->wq_index;
571 
572 	/* Deep copy keys. */
573 	if (tls_new->params.auth_key != NULL) {
574 		tls_new->params.auth_key = malloc(tls->params.auth_key_len,
575 		    M_KTLS, M_WAITOK);
576 		memcpy(tls_new->params.auth_key, tls->params.auth_key,
577 		    tls->params.auth_key_len);
578 	}
579 
580 	tls_new->params.cipher_key = malloc(tls->params.cipher_key_len, M_KTLS,
581 	    M_WAITOK);
582 	memcpy(tls_new->params.cipher_key, tls->params.cipher_key,
583 	    tls->params.cipher_key_len);
584 
585 	return (tls_new);
586 }
587 #endif
588 
589 static void
590 ktls_cleanup(struct ktls_session *tls)
591 {
592 
593 	counter_u64_add(ktls_offload_active, -1);
594 	if (tls->free != NULL) {
595 		MPASS(tls->be != NULL);
596 		switch (tls->params.cipher_algorithm) {
597 		case CRYPTO_AES_CBC:
598 			counter_u64_add(ktls_sw_cbc, -1);
599 			break;
600 		case CRYPTO_AES_NIST_GCM_16:
601 			counter_u64_add(ktls_sw_gcm, -1);
602 			break;
603 		}
604 		tls->free(tls);
605 	} else if (tls->snd_tag != NULL) {
606 		switch (tls->params.cipher_algorithm) {
607 		case CRYPTO_AES_CBC:
608 			counter_u64_add(ktls_ifnet_cbc, -1);
609 			break;
610 		case CRYPTO_AES_NIST_GCM_16:
611 			counter_u64_add(ktls_ifnet_gcm, -1);
612 			break;
613 		}
614 		m_snd_tag_rele(tls->snd_tag);
615 	}
616 	if (tls->params.auth_key != NULL) {
617 		explicit_bzero(tls->params.auth_key, tls->params.auth_key_len);
618 		free(tls->params.auth_key, M_KTLS);
619 		tls->params.auth_key = NULL;
620 		tls->params.auth_key_len = 0;
621 	}
622 	if (tls->params.cipher_key != NULL) {
623 		explicit_bzero(tls->params.cipher_key,
624 		    tls->params.cipher_key_len);
625 		free(tls->params.cipher_key, M_KTLS);
626 		tls->params.cipher_key = NULL;
627 		tls->params.cipher_key_len = 0;
628 	}
629 	explicit_bzero(tls->params.iv, sizeof(tls->params.iv));
630 }
631 
632 #if defined(INET) || defined(INET6)
633 /*
634  * Common code used when first enabling ifnet TLS on a connection or
635  * when allocating a new ifnet TLS session due to a routing change.
636  * This function allocates a new TLS send tag on whatever interface
637  * the connection is currently routed over.
638  */
639 static int
640 ktls_alloc_snd_tag(struct inpcb *inp, struct ktls_session *tls, bool force,
641     struct m_snd_tag **mstp)
642 {
643 	union if_snd_tag_alloc_params params;
644 	struct ifnet *ifp;
645 	struct rtentry *rt;
646 	struct tcpcb *tp;
647 	int error;
648 
649 	INP_RLOCK(inp);
650 	if (inp->inp_flags2 & INP_FREED) {
651 		INP_RUNLOCK(inp);
652 		return (ECONNRESET);
653 	}
654 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
655 		INP_RUNLOCK(inp);
656 		return (ECONNRESET);
657 	}
658 	if (inp->inp_socket == NULL) {
659 		INP_RUNLOCK(inp);
660 		return (ECONNRESET);
661 	}
662 	tp = intotcpcb(inp);
663 
664 	/*
665 	 * Check administrative controls on ifnet TLS to determine if
666 	 * ifnet TLS should be denied.
667 	 *
668 	 * - Always permit 'force' requests.
669 	 * - ktls_ifnet_permitted == 0: always deny.
670 	 */
671 	if (!force && ktls_ifnet_permitted == 0) {
672 		INP_RUNLOCK(inp);
673 		return (ENXIO);
674 	}
675 
676 	/*
677 	 * XXX: Use the cached route in the inpcb to find the
678 	 * interface.  This should perhaps instead use
679 	 * rtalloc1_fib(dst, 0, 0, fibnum).  Since KTLS is only
680 	 * enabled after a connection has completed key negotiation in
681 	 * userland, the cached route will be present in practice.
682 	 */
683 	rt = inp->inp_route.ro_rt;
684 	if (rt == NULL || rt->rt_ifp == NULL) {
685 		INP_RUNLOCK(inp);
686 		return (ENXIO);
687 	}
688 	ifp = rt->rt_ifp;
689 	if_ref(ifp);
690 
691 	params.hdr.type = IF_SND_TAG_TYPE_TLS;
692 	params.hdr.flowid = inp->inp_flowid;
693 	params.hdr.flowtype = inp->inp_flowtype;
694 	params.tls.inp = inp;
695 	params.tls.tls = tls;
696 	INP_RUNLOCK(inp);
697 
698 	if (ifp->if_snd_tag_alloc == NULL) {
699 		error = EOPNOTSUPP;
700 		goto out;
701 	}
702 	if ((ifp->if_capenable & IFCAP_NOMAP) == 0) {
703 		error = EOPNOTSUPP;
704 		goto out;
705 	}
706 	if (inp->inp_vflag & INP_IPV6) {
707 		if ((ifp->if_capenable & IFCAP_TXTLS6) == 0) {
708 			error = EOPNOTSUPP;
709 			goto out;
710 		}
711 	} else {
712 		if ((ifp->if_capenable & IFCAP_TXTLS4) == 0) {
713 			error = EOPNOTSUPP;
714 			goto out;
715 		}
716 	}
717 	error = ifp->if_snd_tag_alloc(ifp, &params, mstp);
718 out:
719 	if_rele(ifp);
720 	return (error);
721 }
722 
723 static int
724 ktls_try_ifnet(struct socket *so, struct ktls_session *tls, bool force)
725 {
726 	struct m_snd_tag *mst;
727 	int error;
728 
729 	error = ktls_alloc_snd_tag(so->so_pcb, tls, force, &mst);
730 	if (error == 0) {
731 		tls->snd_tag = mst;
732 		switch (tls->params.cipher_algorithm) {
733 		case CRYPTO_AES_CBC:
734 			counter_u64_add(ktls_ifnet_cbc, 1);
735 			break;
736 		case CRYPTO_AES_NIST_GCM_16:
737 			counter_u64_add(ktls_ifnet_gcm, 1);
738 			break;
739 		}
740 	}
741 	return (error);
742 }
743 
744 static int
745 ktls_try_sw(struct socket *so, struct ktls_session *tls)
746 {
747 	struct rm_priotracker prio;
748 	struct ktls_crypto_backend *be;
749 
750 	/*
751 	 * Choose the best software crypto backend.  Backends are
752 	 * stored in sorted priority order (larget value == most
753 	 * important at the head of the list), so this just stops on
754 	 * the first backend that claims the session by returning
755 	 * success.
756 	 */
757 	if (ktls_allow_unload)
758 		rm_rlock(&ktls_backends_lock, &prio);
759 	LIST_FOREACH(be, &ktls_backends, next) {
760 		if (be->try(so, tls) == 0)
761 			break;
762 		KASSERT(tls->cipher == NULL,
763 		    ("ktls backend leaked a cipher pointer"));
764 	}
765 	if (be != NULL) {
766 		if (ktls_allow_unload)
767 			be->use_count++;
768 		tls->be = be;
769 	}
770 	if (ktls_allow_unload)
771 		rm_runlock(&ktls_backends_lock, &prio);
772 	if (be == NULL)
773 		return (EOPNOTSUPP);
774 	switch (tls->params.cipher_algorithm) {
775 	case CRYPTO_AES_CBC:
776 		counter_u64_add(ktls_sw_cbc, 1);
777 		break;
778 	case CRYPTO_AES_NIST_GCM_16:
779 		counter_u64_add(ktls_sw_gcm, 1);
780 		break;
781 	}
782 	return (0);
783 }
784 
785 int
786 ktls_enable_tx(struct socket *so, struct tls_enable *en)
787 {
788 	struct ktls_session *tls;
789 	int error;
790 
791 	if (!ktls_offload_enable)
792 		return (ENOTSUP);
793 
794 	counter_u64_add(ktls_offload_enable_calls, 1);
795 
796 	/*
797 	 * This should always be true since only the TCP socket option
798 	 * invokes this function.
799 	 */
800 	if (so->so_proto->pr_protocol != IPPROTO_TCP)
801 		return (EINVAL);
802 
803 	/*
804 	 * XXX: Don't overwrite existing sessions.  We should permit
805 	 * this to support rekeying in the future.
806 	 */
807 	if (so->so_snd.sb_tls_info != NULL)
808 		return (EALREADY);
809 
810 	if (en->cipher_algorithm == CRYPTO_AES_CBC && !ktls_cbc_enable)
811 		return (ENOTSUP);
812 
813 	/* TLS requires ext pgs */
814 	if (mb_use_ext_pgs == 0)
815 		return (ENXIO);
816 
817 	error = ktls_create_session(so, en, &tls);
818 	if (error)
819 		return (error);
820 
821 	/* Prefer ifnet TLS over software TLS. */
822 	error = ktls_try_ifnet(so, tls, false);
823 	if (error)
824 		error = ktls_try_sw(so, tls);
825 
826 	if (error) {
827 		ktls_cleanup(tls);
828 		return (error);
829 	}
830 
831 	error = sblock(&so->so_snd, SBL_WAIT);
832 	if (error) {
833 		ktls_cleanup(tls);
834 		return (error);
835 	}
836 
837 	SOCKBUF_LOCK(&so->so_snd);
838 	so->so_snd.sb_tls_info = tls;
839 	if (tls->sw_encrypt == NULL)
840 		so->so_snd.sb_flags |= SB_TLS_IFNET;
841 	SOCKBUF_UNLOCK(&so->so_snd);
842 	sbunlock(&so->so_snd);
843 
844 	counter_u64_add(ktls_offload_total, 1);
845 
846 	return (0);
847 }
848 
849 int
850 ktls_get_tx_mode(struct socket *so)
851 {
852 	struct ktls_session *tls;
853 	struct inpcb *inp;
854 	int mode;
855 
856 	inp = so->so_pcb;
857 	INP_WLOCK_ASSERT(inp);
858 	SOCKBUF_LOCK(&so->so_snd);
859 	tls = so->so_snd.sb_tls_info;
860 	if (tls == NULL)
861 		mode = TCP_TLS_MODE_NONE;
862 	else if (tls->sw_encrypt != NULL)
863 		mode = TCP_TLS_MODE_SW;
864 	else
865 		mode = TCP_TLS_MODE_IFNET;
866 	SOCKBUF_UNLOCK(&so->so_snd);
867 	return (mode);
868 }
869 
870 /*
871  * Switch between SW and ifnet TLS sessions as requested.
872  */
873 int
874 ktls_set_tx_mode(struct socket *so, int mode)
875 {
876 	struct ktls_session *tls, *tls_new;
877 	struct inpcb *inp;
878 	int error;
879 
880 	MPASS(mode == TCP_TLS_MODE_SW || mode == TCP_TLS_MODE_IFNET);
881 
882 	inp = so->so_pcb;
883 	INP_WLOCK_ASSERT(inp);
884 	SOCKBUF_LOCK(&so->so_snd);
885 	tls = so->so_snd.sb_tls_info;
886 	if (tls == NULL) {
887 		SOCKBUF_UNLOCK(&so->so_snd);
888 		return (0);
889 	}
890 
891 	if ((tls->sw_encrypt != NULL && mode == TCP_TLS_MODE_SW) ||
892 	    (tls->sw_encrypt == NULL && mode == TCP_TLS_MODE_IFNET)) {
893 		SOCKBUF_UNLOCK(&so->so_snd);
894 		return (0);
895 	}
896 
897 	tls = ktls_hold(tls);
898 	SOCKBUF_UNLOCK(&so->so_snd);
899 	INP_WUNLOCK(inp);
900 
901 	tls_new = ktls_clone_session(tls);
902 
903 	if (mode == TCP_TLS_MODE_IFNET)
904 		error = ktls_try_ifnet(so, tls_new, true);
905 	else
906 		error = ktls_try_sw(so, tls_new);
907 	if (error) {
908 		counter_u64_add(ktls_switch_failed, 1);
909 		ktls_free(tls_new);
910 		ktls_free(tls);
911 		INP_WLOCK(inp);
912 		return (error);
913 	}
914 
915 	error = sblock(&so->so_snd, SBL_WAIT);
916 	if (error) {
917 		counter_u64_add(ktls_switch_failed, 1);
918 		ktls_free(tls_new);
919 		ktls_free(tls);
920 		INP_WLOCK(inp);
921 		return (error);
922 	}
923 
924 	/*
925 	 * If we raced with another session change, keep the existing
926 	 * session.
927 	 */
928 	if (tls != so->so_snd.sb_tls_info) {
929 		counter_u64_add(ktls_switch_failed, 1);
930 		sbunlock(&so->so_snd);
931 		ktls_free(tls_new);
932 		ktls_free(tls);
933 		INP_WLOCK(inp);
934 		return (EBUSY);
935 	}
936 
937 	SOCKBUF_LOCK(&so->so_snd);
938 	so->so_snd.sb_tls_info = tls_new;
939 	if (tls_new->sw_encrypt == NULL)
940 		so->so_snd.sb_flags |= SB_TLS_IFNET;
941 	SOCKBUF_UNLOCK(&so->so_snd);
942 	sbunlock(&so->so_snd);
943 
944 	/*
945 	 * Drop two references on 'tls'.  The first is for the
946 	 * ktls_hold() above.  The second drops the reference from the
947 	 * socket buffer.
948 	 */
949 	KASSERT(tls->refcount >= 2, ("too few references on old session"));
950 	ktls_free(tls);
951 	ktls_free(tls);
952 
953 	if (mode == TCP_TLS_MODE_IFNET)
954 		counter_u64_add(ktls_switch_to_ifnet, 1);
955 	else
956 		counter_u64_add(ktls_switch_to_sw, 1);
957 
958 	INP_WLOCK(inp);
959 	return (0);
960 }
961 
962 /*
963  * Try to allocate a new TLS send tag.  This task is scheduled when
964  * ip_output detects a route change while trying to transmit a packet
965  * holding a TLS record.  If a new tag is allocated, replace the tag
966  * in the TLS session.  Subsequent packets on the connection will use
967  * the new tag.  If a new tag cannot be allocated, drop the
968  * connection.
969  */
970 static void
971 ktls_reset_send_tag(void *context, int pending)
972 {
973 	struct epoch_tracker et;
974 	struct ktls_session *tls;
975 	struct m_snd_tag *old, *new;
976 	struct inpcb *inp;
977 	struct tcpcb *tp;
978 	int error;
979 
980 	MPASS(pending == 1);
981 
982 	tls = context;
983 	inp = tls->inp;
984 
985 	/*
986 	 * Free the old tag first before allocating a new one.
987 	 * ip[6]_output_send() will treat a NULL send tag the same as
988 	 * an ifp mismatch and drop packets until a new tag is
989 	 * allocated.
990 	 *
991 	 * Write-lock the INP when changing tls->snd_tag since
992 	 * ip[6]_output_send() holds a read-lock when reading the
993 	 * pointer.
994 	 */
995 	INP_WLOCK(inp);
996 	old = tls->snd_tag;
997 	tls->snd_tag = NULL;
998 	INP_WUNLOCK(inp);
999 	if (old != NULL)
1000 		m_snd_tag_rele(old);
1001 
1002 	error = ktls_alloc_snd_tag(inp, tls, true, &new);
1003 
1004 	if (error == 0) {
1005 		INP_WLOCK(inp);
1006 		tls->snd_tag = new;
1007 		mtx_pool_lock(mtxpool_sleep, tls);
1008 		tls->reset_pending = false;
1009 		mtx_pool_unlock(mtxpool_sleep, tls);
1010 		if (!in_pcbrele_wlocked(inp))
1011 			INP_WUNLOCK(inp);
1012 
1013 		counter_u64_add(ktls_ifnet_reset, 1);
1014 
1015 		/*
1016 		 * XXX: Should we kick tcp_output explicitly now that
1017 		 * the send tag is fixed or just rely on timers?
1018 		 */
1019 	} else {
1020 		INP_INFO_RLOCK_ET(&V_tcbinfo, et);
1021 		INP_WLOCK(inp);
1022 		if (!in_pcbrele_wlocked(inp)) {
1023 			if (!(inp->inp_flags & INP_TIMEWAIT) &&
1024 			    !(inp->inp_flags & INP_DROPPED)) {
1025 				tp = intotcpcb(inp);
1026 				tp = tcp_drop(tp, ECONNABORTED);
1027 				if (tp != NULL)
1028 					INP_WUNLOCK(inp);
1029 				counter_u64_add(ktls_ifnet_reset_dropped, 1);
1030 			} else
1031 				INP_WUNLOCK(inp);
1032 		}
1033 		INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
1034 
1035 		counter_u64_add(ktls_ifnet_reset_failed, 1);
1036 
1037 		/*
1038 		 * Leave reset_pending true to avoid future tasks while
1039 		 * the socket goes away.
1040 		 */
1041 	}
1042 
1043 	ktls_free(tls);
1044 }
1045 
1046 int
1047 ktls_output_eagain(struct inpcb *inp, struct ktls_session *tls)
1048 {
1049 
1050 	if (inp == NULL)
1051 		return (ENOBUFS);
1052 
1053 	INP_LOCK_ASSERT(inp);
1054 
1055 	/*
1056 	 * See if we should schedule a task to update the send tag for
1057 	 * this session.
1058 	 */
1059 	mtx_pool_lock(mtxpool_sleep, tls);
1060 	if (!tls->reset_pending) {
1061 		(void) ktls_hold(tls);
1062 		in_pcbref(inp);
1063 		tls->inp = inp;
1064 		tls->reset_pending = true;
1065 		taskqueue_enqueue(taskqueue_thread, &tls->reset_tag_task);
1066 	}
1067 	mtx_pool_unlock(mtxpool_sleep, tls);
1068 	return (ENOBUFS);
1069 }
1070 #endif
1071 
1072 void
1073 ktls_destroy(struct ktls_session *tls)
1074 {
1075 	struct rm_priotracker prio;
1076 
1077 	ktls_cleanup(tls);
1078 	if (tls->be != NULL && ktls_allow_unload) {
1079 		rm_rlock(&ktls_backends_lock, &prio);
1080 		tls->be->use_count--;
1081 		rm_runlock(&ktls_backends_lock, &prio);
1082 	}
1083 	uma_zfree(ktls_session_zone, tls);
1084 }
1085 
1086 void
1087 ktls_seq(struct sockbuf *sb, struct mbuf *m)
1088 {
1089 	struct mbuf_ext_pgs *pgs;
1090 	struct tls_record_layer *tlshdr;
1091 	uint64_t seqno;
1092 
1093 	for (; m != NULL; m = m->m_next) {
1094 		KASSERT((m->m_flags & M_NOMAP) != 0,
1095 		    ("ktls_seq: mapped mbuf %p", m));
1096 
1097 		pgs = m->m_ext.ext_pgs;
1098 		pgs->seqno = sb->sb_tls_seqno;
1099 
1100 		/*
1101 		 * Store the sequence number in the TLS header as the
1102 		 * explicit part of the IV for GCM.
1103 		 */
1104 		if (pgs->tls->params.cipher_algorithm ==
1105 		    CRYPTO_AES_NIST_GCM_16) {
1106 			tlshdr = (void *)pgs->hdr;
1107 			seqno = htobe64(pgs->seqno);
1108 			memcpy(tlshdr + 1, &seqno, sizeof(seqno));
1109 		}
1110 		sb->sb_tls_seqno++;
1111 	}
1112 }
1113 
1114 /*
1115  * Add TLS framing (headers and trailers) to a chain of mbufs.  Each
1116  * mbuf in the chain must be an unmapped mbuf.  The payload of the
1117  * mbuf must be populated with the payload of each TLS record.
1118  *
1119  * The record_type argument specifies the TLS record type used when
1120  * populating the TLS header.
1121  *
1122  * The enq_count argument on return is set to the number of pages of
1123  * payload data for this entire chain that need to be encrypted via SW
1124  * encryption.  The returned value should be passed to ktls_enqueue
1125  * when scheduling encryption of this chain of mbufs.
1126  */
1127 int
1128 ktls_frame(struct mbuf *top, struct ktls_session *tls, int *enq_cnt,
1129     uint8_t record_type)
1130 {
1131 	struct tls_record_layer *tlshdr;
1132 	struct mbuf *m;
1133 	struct mbuf_ext_pgs *pgs;
1134 	uint16_t tls_len;
1135 	int maxlen;
1136 
1137 	maxlen = tls->params.max_frame_len;
1138 	*enq_cnt = 0;
1139 	for (m = top; m != NULL; m = m->m_next) {
1140 		/*
1141 		 * All mbufs in the chain should be non-empty TLS
1142 		 * records whose payload does not exceed the maximum
1143 		 * frame length.
1144 		 */
1145 		if (m->m_len > maxlen || m->m_len == 0)
1146 			return (EINVAL);
1147 		tls_len = m->m_len;
1148 
1149 		/*
1150 		 * TLS frames require unmapped mbufs to store session
1151 		 * info.
1152 		 */
1153 		KASSERT((m->m_flags & M_NOMAP) != 0,
1154 		    ("ktls_frame: mapped mbuf %p (top = %p)\n", m, top));
1155 
1156 		pgs = m->m_ext.ext_pgs;
1157 
1158 		/* Save a reference to the session. */
1159 		pgs->tls = ktls_hold(tls);
1160 
1161 		pgs->hdr_len = tls->params.tls_hlen;
1162 		pgs->trail_len = tls->params.tls_tlen;
1163 		if (tls->params.cipher_algorithm == CRYPTO_AES_CBC) {
1164 			int bs, delta;
1165 
1166 			/*
1167 			 * AES-CBC pads messages to a multiple of the
1168 			 * block size.  Note that the padding is
1169 			 * applied after the digest and the encryption
1170 			 * is done on the "plaintext || mac || padding".
1171 			 * At least one byte of padding is always
1172 			 * present.
1173 			 *
1174 			 * Compute the final trailer length assuming
1175 			 * at most one block of padding.
1176 			 * tls->params.sb_tls_tlen is the maximum
1177 			 * possible trailer length (padding + digest).
1178 			 * delta holds the number of excess padding
1179 			 * bytes if the maximum were used.  Those
1180 			 * extra bytes are removed.
1181 			 */
1182 			bs = tls->params.tls_bs;
1183 			delta = (tls_len + tls->params.tls_tlen) & (bs - 1);
1184 			pgs->trail_len -= delta;
1185 		}
1186 		m->m_len += pgs->hdr_len + pgs->trail_len;
1187 
1188 		/* Populate the TLS header. */
1189 		tlshdr = (void *)pgs->hdr;
1190 		tlshdr->tls_vmajor = tls->params.tls_vmajor;
1191 		tlshdr->tls_vminor = tls->params.tls_vminor;
1192 		tlshdr->tls_type = record_type;
1193 		tlshdr->tls_length = htons(m->m_len - sizeof(*tlshdr));
1194 
1195 		/*
1196 		 * For GCM, the sequence number is stored in the
1197 		 * header by ktls_seq().  For CBC, a random nonce is
1198 		 * inserted for TLS 1.1+.
1199 		 */
1200 		if (tls->params.cipher_algorithm == CRYPTO_AES_CBC &&
1201 		    tls->params.tls_vminor >= TLS_MINOR_VER_ONE)
1202 			arc4rand(tlshdr + 1, AES_BLOCK_LEN, 0);
1203 
1204 		/*
1205 		 * When using SW encryption, mark the mbuf not ready.
1206 		 * It will be marked ready via sbready() after the
1207 		 * record has been encrypted.
1208 		 *
1209 		 * When using ifnet TLS, unencrypted TLS records are
1210 		 * sent down the stack to the NIC.
1211 		 */
1212 		if (tls->sw_encrypt != NULL) {
1213 			m->m_flags |= M_NOTREADY;
1214 			pgs->nrdy = pgs->npgs;
1215 			*enq_cnt += pgs->npgs;
1216 		}
1217 	}
1218 	return (0);
1219 }
1220 
1221 void
1222 ktls_enqueue_to_free(struct mbuf_ext_pgs *pgs)
1223 {
1224 	struct ktls_wq *wq;
1225 	bool running;
1226 
1227 	/* Mark it for freeing. */
1228 	pgs->mbuf = NULL;
1229 	wq = &ktls_wq[pgs->tls->wq_index];
1230 	mtx_lock(&wq->mtx);
1231 	STAILQ_INSERT_TAIL(&wq->head, pgs, stailq);
1232 	running = wq->running;
1233 	mtx_unlock(&wq->mtx);
1234 	if (!running)
1235 		wakeup(wq);
1236 }
1237 
1238 void
1239 ktls_enqueue(struct mbuf *m, struct socket *so, int page_count)
1240 {
1241 	struct mbuf_ext_pgs *pgs;
1242 	struct ktls_wq *wq;
1243 	bool running;
1244 
1245 	KASSERT(((m->m_flags & (M_NOMAP | M_NOTREADY)) ==
1246 	    (M_NOMAP | M_NOTREADY)),
1247 	    ("ktls_enqueue: %p not unready & nomap mbuf\n", m));
1248 	KASSERT(page_count != 0, ("enqueueing TLS mbuf with zero page count"));
1249 
1250 	pgs = m->m_ext.ext_pgs;
1251 
1252 	KASSERT(pgs->tls->sw_encrypt != NULL, ("ifnet TLS mbuf"));
1253 
1254 	pgs->enc_cnt = page_count;
1255 	pgs->mbuf = m;
1256 
1257 	/*
1258 	 * Save a pointer to the socket.  The caller is responsible
1259 	 * for taking an additional reference via soref().
1260 	 */
1261 	pgs->so = so;
1262 
1263 	wq = &ktls_wq[pgs->tls->wq_index];
1264 	mtx_lock(&wq->mtx);
1265 	STAILQ_INSERT_TAIL(&wq->head, pgs, stailq);
1266 	running = wq->running;
1267 	mtx_unlock(&wq->mtx);
1268 	if (!running)
1269 		wakeup(wq);
1270 	counter_u64_add(ktls_cnt_on, 1);
1271 }
1272 
1273 static __noinline void
1274 ktls_encrypt(struct mbuf_ext_pgs *pgs)
1275 {
1276 	struct ktls_session *tls;
1277 	struct socket *so;
1278 	struct mbuf *m, *top;
1279 	vm_paddr_t parray[1 + btoc(TLS_MAX_MSG_SIZE_V10_2)];
1280 	struct iovec src_iov[1 + btoc(TLS_MAX_MSG_SIZE_V10_2)];
1281 	struct iovec dst_iov[1 + btoc(TLS_MAX_MSG_SIZE_V10_2)];
1282 	vm_page_t pg;
1283 	int error, i, len, npages, off, total_pages;
1284 	bool is_anon;
1285 
1286 	so = pgs->so;
1287 	tls = pgs->tls;
1288 	top = pgs->mbuf;
1289 	KASSERT(tls != NULL, ("tls = NULL, top = %p, pgs = %p\n", top, pgs));
1290 	KASSERT(so != NULL, ("so = NULL, top = %p, pgs = %p\n", top, pgs));
1291 #ifdef INVARIANTS
1292 	pgs->so = NULL;
1293 	pgs->mbuf = NULL;
1294 #endif
1295 	total_pages = pgs->enc_cnt;
1296 	npages = 0;
1297 
1298 	/*
1299 	 * Encrypt the TLS records in the chain of mbufs starting with
1300 	 * 'top'.  'total_pages' gives us a total count of pages and is
1301 	 * used to know when we have finished encrypting the TLS
1302 	 * records originally queued with 'top'.
1303 	 *
1304 	 * NB: These mbufs are queued in the socket buffer and
1305 	 * 'm_next' is traversing the mbufs in the socket buffer.  The
1306 	 * socket buffer lock is not held while traversing this chain.
1307 	 * Since the mbufs are all marked M_NOTREADY their 'm_next'
1308 	 * pointers should be stable.  However, the 'm_next' of the
1309 	 * last mbuf encrypted is not necessarily NULL.  It can point
1310 	 * to other mbufs appended while 'top' was on the TLS work
1311 	 * queue.
1312 	 *
1313 	 * Each mbuf holds an entire TLS record.
1314 	 */
1315 	error = 0;
1316 	for (m = top; npages != total_pages; m = m->m_next) {
1317 		pgs = m->m_ext.ext_pgs;
1318 
1319 		KASSERT(pgs->tls == tls,
1320 		    ("different TLS sessions in a single mbuf chain: %p vs %p",
1321 		    tls, pgs->tls));
1322 		KASSERT((m->m_flags & (M_NOMAP | M_NOTREADY)) ==
1323 		    (M_NOMAP | M_NOTREADY),
1324 		    ("%p not unready & nomap mbuf (top = %p)\n", m, top));
1325 		KASSERT(npages + pgs->npgs <= total_pages,
1326 		    ("page count mismatch: top %p, total_pages %d, m %p", top,
1327 		    total_pages, m));
1328 
1329 		/*
1330 		 * Generate source and destination ivoecs to pass to
1331 		 * the SW encryption backend.  For writable mbufs, the
1332 		 * destination iovec is a copy of the source and
1333 		 * encryption is done in place.  For file-backed mbufs
1334 		 * (from sendfile), anonymous wired pages are
1335 		 * allocated and assigned to the destination iovec.
1336 		 */
1337 		is_anon = M_WRITABLE(m);
1338 
1339 		off = pgs->first_pg_off;
1340 		for (i = 0; i < pgs->npgs; i++, off = 0) {
1341 			len = mbuf_ext_pg_len(pgs, i, off);
1342 			src_iov[i].iov_len = len;
1343 			src_iov[i].iov_base =
1344 			    (char *)(void *)PHYS_TO_DMAP(pgs->pa[i]) + off;
1345 
1346 			if (is_anon) {
1347 				dst_iov[i].iov_base = src_iov[i].iov_base;
1348 				dst_iov[i].iov_len = src_iov[i].iov_len;
1349 				continue;
1350 			}
1351 retry_page:
1352 			pg = vm_page_alloc(NULL, 0, VM_ALLOC_NORMAL |
1353 			    VM_ALLOC_NOOBJ | VM_ALLOC_NODUMP | VM_ALLOC_WIRED);
1354 			if (pg == NULL) {
1355 				vm_wait(NULL);
1356 				goto retry_page;
1357 			}
1358 			parray[i] = VM_PAGE_TO_PHYS(pg);
1359 			dst_iov[i].iov_base =
1360 			    (char *)(void *)PHYS_TO_DMAP(parray[i]) + off;
1361 			dst_iov[i].iov_len = len;
1362 		}
1363 
1364 		npages += i;
1365 
1366 		error = (*tls->sw_encrypt)(tls,
1367 		    (const struct tls_record_layer *)pgs->hdr,
1368 		    pgs->trail, src_iov, dst_iov, i, pgs->seqno);
1369 		if (error) {
1370 			counter_u64_add(ktls_offload_failed_crypto, 1);
1371 			break;
1372 		}
1373 
1374 		/*
1375 		 * For file-backed mbufs, release the file-backed
1376 		 * pages and replace them in the ext_pgs array with
1377 		 * the anonymous wired pages allocated above.
1378 		 */
1379 		if (!is_anon) {
1380 			/* Free the old pages. */
1381 			m->m_ext.ext_free(m);
1382 
1383 			/* Replace them with the new pages. */
1384 			for (i = 0; i < pgs->npgs; i++)
1385 				pgs->pa[i] = parray[i];
1386 
1387 			/* Use the basic free routine. */
1388 			m->m_ext.ext_free = mb_free_mext_pgs;
1389 		}
1390 
1391 		/*
1392 		 * Drop a reference to the session now that it is no
1393 		 * longer needed.  Existing code depends on encrypted
1394 		 * records having no associated session vs
1395 		 * yet-to-be-encrypted records having an associated
1396 		 * session.
1397 		 */
1398 		pgs->tls = NULL;
1399 		ktls_free(tls);
1400 	}
1401 
1402 	CURVNET_SET(so->so_vnet);
1403 	if (error == 0) {
1404 		(void)(*so->so_proto->pr_usrreqs->pru_ready)(so, top, npages);
1405 	} else {
1406 		so->so_proto->pr_usrreqs->pru_abort(so);
1407 		so->so_error = EIO;
1408 		mb_free_notready(top, total_pages);
1409 	}
1410 
1411 	SOCK_LOCK(so);
1412 	sorele(so);
1413 	CURVNET_RESTORE();
1414 }
1415 
1416 static void
1417 ktls_work_thread(void *ctx)
1418 {
1419 	struct ktls_wq *wq = ctx;
1420 	struct mbuf_ext_pgs *p, *n;
1421 	struct ktls_session *tls;
1422 	STAILQ_HEAD(, mbuf_ext_pgs) local_head;
1423 
1424 #if defined(__aarch64__) || defined(__amd64__) || defined(__i386__)
1425 	fpu_kern_thread(0);
1426 #endif
1427 	for (;;) {
1428 		mtx_lock(&wq->mtx);
1429 		while (STAILQ_EMPTY(&wq->head)) {
1430 			wq->running = false;
1431 			mtx_sleep(wq, &wq->mtx, 0, "-", 0);
1432 			wq->running = true;
1433 		}
1434 
1435 		STAILQ_INIT(&local_head);
1436 		STAILQ_CONCAT(&local_head, &wq->head);
1437 		mtx_unlock(&wq->mtx);
1438 
1439 		STAILQ_FOREACH_SAFE(p, &local_head, stailq, n) {
1440 			if (p->mbuf != NULL) {
1441 				ktls_encrypt(p);
1442 				counter_u64_add(ktls_cnt_on, -1);
1443 			} else {
1444 				tls = p->tls;
1445 				ktls_free(tls);
1446 				uma_zfree(zone_extpgs, p);
1447 			}
1448 		}
1449 	}
1450 }
1451