xref: /freebsd/sys/kern/uipc_ktls.c (revision f18976136625a7d016e97bfd9eabddf640b3e06d)
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", "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_THREE)
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 > sizeof(tls->params.iv))
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->tls_vminor == TLS_MINOR_VER_TWO &&
429 			en->iv_len != TLS_AEAD_GCM_LEN) ||
430 		    (en->tls_vminor == TLS_MINOR_VER_THREE &&
431 			en->iv_len != TLS_1_3_GCM_IV_LEN))
432 			return (EINVAL);
433 		break;
434 	case CRYPTO_AES_CBC:
435 		switch (en->auth_algorithm) {
436 		case CRYPTO_SHA1_HMAC:
437 			/*
438 			 * TLS 1.0 requires an implicit IV.  TLS 1.1+
439 			 * all use explicit IVs.
440 			 */
441 			if (en->tls_vminor == TLS_MINOR_VER_ZERO) {
442 				if (en->iv_len != TLS_CBC_IMPLICIT_IV_LEN)
443 					return (EINVAL);
444 				break;
445 			}
446 
447 			/* FALLTHROUGH */
448 		case CRYPTO_SHA2_256_HMAC:
449 		case CRYPTO_SHA2_384_HMAC:
450 			/* Ignore any supplied IV. */
451 			en->iv_len = 0;
452 			break;
453 		default:
454 			return (EINVAL);
455 		}
456 		if (en->auth_key_len == 0)
457 			return (EINVAL);
458 		break;
459 	default:
460 		return (EINVAL);
461 	}
462 
463 	tls = uma_zalloc(ktls_session_zone, M_WAITOK | M_ZERO);
464 
465 	counter_u64_add(ktls_offload_active, 1);
466 
467 	refcount_init(&tls->refcount, 1);
468 	TASK_INIT(&tls->reset_tag_task, 0, ktls_reset_send_tag, tls);
469 
470 	tls->wq_index = ktls_get_cpu(so);
471 
472 	tls->params.cipher_algorithm = en->cipher_algorithm;
473 	tls->params.auth_algorithm = en->auth_algorithm;
474 	tls->params.tls_vmajor = en->tls_vmajor;
475 	tls->params.tls_vminor = en->tls_vminor;
476 	tls->params.flags = en->flags;
477 	tls->params.max_frame_len = min(TLS_MAX_MSG_SIZE_V10_2, ktls_maxlen);
478 
479 	/* Set the header and trailer lengths. */
480 	tls->params.tls_hlen = sizeof(struct tls_record_layer);
481 	switch (en->cipher_algorithm) {
482 	case CRYPTO_AES_NIST_GCM_16:
483 		/*
484 		 * TLS 1.2 uses a 4 byte implicit IV with an explicit 8 byte
485 		 * nonce.  TLS 1.3 uses a 12 byte implicit IV.
486 		 */
487 		if (en->tls_vminor < TLS_MINOR_VER_THREE)
488 			tls->params.tls_hlen += sizeof(uint64_t);
489 		tls->params.tls_tlen = AES_GMAC_HASH_LEN;
490 
491 		/*
492 		 * TLS 1.3 includes optional padding which we
493 		 * do not support, and also puts the "real" record
494 		 * type at the end of the encrypted data.
495 		 */
496 		if (en->tls_vminor == TLS_MINOR_VER_THREE)
497 			tls->params.tls_tlen += sizeof(uint8_t);
498 
499 		tls->params.tls_bs = 1;
500 		break;
501 	case CRYPTO_AES_CBC:
502 		switch (en->auth_algorithm) {
503 		case CRYPTO_SHA1_HMAC:
504 			if (en->tls_vminor == TLS_MINOR_VER_ZERO) {
505 				/* Implicit IV, no nonce. */
506 			} else {
507 				tls->params.tls_hlen += AES_BLOCK_LEN;
508 			}
509 			tls->params.tls_tlen = AES_BLOCK_LEN +
510 			    SHA1_HASH_LEN;
511 			break;
512 		case CRYPTO_SHA2_256_HMAC:
513 			tls->params.tls_hlen += AES_BLOCK_LEN;
514 			tls->params.tls_tlen = AES_BLOCK_LEN +
515 			    SHA2_256_HASH_LEN;
516 			break;
517 		case CRYPTO_SHA2_384_HMAC:
518 			tls->params.tls_hlen += AES_BLOCK_LEN;
519 			tls->params.tls_tlen = AES_BLOCK_LEN +
520 			    SHA2_384_HASH_LEN;
521 			break;
522 		default:
523 			panic("invalid hmac");
524 		}
525 		tls->params.tls_bs = AES_BLOCK_LEN;
526 		break;
527 	default:
528 		panic("invalid cipher");
529 	}
530 
531 	KASSERT(tls->params.tls_hlen <= MBUF_PEXT_HDR_LEN,
532 	    ("TLS header length too long: %d", tls->params.tls_hlen));
533 	KASSERT(tls->params.tls_tlen <= MBUF_PEXT_TRAIL_LEN,
534 	    ("TLS trailer length too long: %d", tls->params.tls_tlen));
535 
536 	if (en->auth_key_len != 0) {
537 		tls->params.auth_key_len = en->auth_key_len;
538 		tls->params.auth_key = malloc(en->auth_key_len, M_KTLS,
539 		    M_WAITOK);
540 		error = copyin(en->auth_key, tls->params.auth_key,
541 		    en->auth_key_len);
542 		if (error)
543 			goto out;
544 	}
545 
546 	tls->params.cipher_key_len = en->cipher_key_len;
547 	tls->params.cipher_key = malloc(en->cipher_key_len, M_KTLS, M_WAITOK);
548 	error = copyin(en->cipher_key, tls->params.cipher_key,
549 	    en->cipher_key_len);
550 	if (error)
551 		goto out;
552 
553 	/*
554 	 * This holds the implicit portion of the nonce for GCM and
555 	 * the initial implicit IV for TLS 1.0.  The explicit portions
556 	 * of the IV are generated in ktls_frame() and ktls_seq().
557 	 */
558 	if (en->iv_len != 0) {
559 		tls->params.iv_len = en->iv_len;
560 		error = copyin(en->iv, tls->params.iv, en->iv_len);
561 		if (error)
562 			goto out;
563 	}
564 
565 	*tlsp = tls;
566 	return (0);
567 
568 out:
569 	ktls_cleanup(tls);
570 	return (error);
571 }
572 
573 static struct ktls_session *
574 ktls_clone_session(struct ktls_session *tls)
575 {
576 	struct ktls_session *tls_new;
577 
578 	tls_new = uma_zalloc(ktls_session_zone, M_WAITOK | M_ZERO);
579 
580 	counter_u64_add(ktls_offload_active, 1);
581 
582 	refcount_init(&tls_new->refcount, 1);
583 
584 	/* Copy fields from existing session. */
585 	tls_new->params = tls->params;
586 	tls_new->wq_index = tls->wq_index;
587 
588 	/* Deep copy keys. */
589 	if (tls_new->params.auth_key != NULL) {
590 		tls_new->params.auth_key = malloc(tls->params.auth_key_len,
591 		    M_KTLS, M_WAITOK);
592 		memcpy(tls_new->params.auth_key, tls->params.auth_key,
593 		    tls->params.auth_key_len);
594 	}
595 
596 	tls_new->params.cipher_key = malloc(tls->params.cipher_key_len, M_KTLS,
597 	    M_WAITOK);
598 	memcpy(tls_new->params.cipher_key, tls->params.cipher_key,
599 	    tls->params.cipher_key_len);
600 
601 	return (tls_new);
602 }
603 #endif
604 
605 static void
606 ktls_cleanup(struct ktls_session *tls)
607 {
608 
609 	counter_u64_add(ktls_offload_active, -1);
610 	if (tls->free != NULL) {
611 		MPASS(tls->be != NULL);
612 		switch (tls->params.cipher_algorithm) {
613 		case CRYPTO_AES_CBC:
614 			counter_u64_add(ktls_sw_cbc, -1);
615 			break;
616 		case CRYPTO_AES_NIST_GCM_16:
617 			counter_u64_add(ktls_sw_gcm, -1);
618 			break;
619 		}
620 		tls->free(tls);
621 	} else if (tls->snd_tag != NULL) {
622 		switch (tls->params.cipher_algorithm) {
623 		case CRYPTO_AES_CBC:
624 			counter_u64_add(ktls_ifnet_cbc, -1);
625 			break;
626 		case CRYPTO_AES_NIST_GCM_16:
627 			counter_u64_add(ktls_ifnet_gcm, -1);
628 			break;
629 		}
630 		m_snd_tag_rele(tls->snd_tag);
631 	}
632 	if (tls->params.auth_key != NULL) {
633 		explicit_bzero(tls->params.auth_key, tls->params.auth_key_len);
634 		free(tls->params.auth_key, M_KTLS);
635 		tls->params.auth_key = NULL;
636 		tls->params.auth_key_len = 0;
637 	}
638 	if (tls->params.cipher_key != NULL) {
639 		explicit_bzero(tls->params.cipher_key,
640 		    tls->params.cipher_key_len);
641 		free(tls->params.cipher_key, M_KTLS);
642 		tls->params.cipher_key = NULL;
643 		tls->params.cipher_key_len = 0;
644 	}
645 	explicit_bzero(tls->params.iv, sizeof(tls->params.iv));
646 }
647 
648 #if defined(INET) || defined(INET6)
649 /*
650  * Common code used when first enabling ifnet TLS on a connection or
651  * when allocating a new ifnet TLS session due to a routing change.
652  * This function allocates a new TLS send tag on whatever interface
653  * the connection is currently routed over.
654  */
655 static int
656 ktls_alloc_snd_tag(struct inpcb *inp, struct ktls_session *tls, bool force,
657     struct m_snd_tag **mstp)
658 {
659 	union if_snd_tag_alloc_params params;
660 	struct ifnet *ifp;
661 	struct rtentry *rt;
662 	struct tcpcb *tp;
663 	int error;
664 
665 	INP_RLOCK(inp);
666 	if (inp->inp_flags2 & INP_FREED) {
667 		INP_RUNLOCK(inp);
668 		return (ECONNRESET);
669 	}
670 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
671 		INP_RUNLOCK(inp);
672 		return (ECONNRESET);
673 	}
674 	if (inp->inp_socket == NULL) {
675 		INP_RUNLOCK(inp);
676 		return (ECONNRESET);
677 	}
678 	tp = intotcpcb(inp);
679 
680 	/*
681 	 * Check administrative controls on ifnet TLS to determine if
682 	 * ifnet TLS should be denied.
683 	 *
684 	 * - Always permit 'force' requests.
685 	 * - ktls_ifnet_permitted == 0: always deny.
686 	 */
687 	if (!force && ktls_ifnet_permitted == 0) {
688 		INP_RUNLOCK(inp);
689 		return (ENXIO);
690 	}
691 
692 	/*
693 	 * XXX: Use the cached route in the inpcb to find the
694 	 * interface.  This should perhaps instead use
695 	 * rtalloc1_fib(dst, 0, 0, fibnum).  Since KTLS is only
696 	 * enabled after a connection has completed key negotiation in
697 	 * userland, the cached route will be present in practice.
698 	 */
699 	rt = inp->inp_route.ro_rt;
700 	if (rt == NULL || rt->rt_ifp == NULL) {
701 		INP_RUNLOCK(inp);
702 		return (ENXIO);
703 	}
704 	ifp = rt->rt_ifp;
705 	if_ref(ifp);
706 
707 	params.hdr.type = IF_SND_TAG_TYPE_TLS;
708 	params.hdr.flowid = inp->inp_flowid;
709 	params.hdr.flowtype = inp->inp_flowtype;
710 	params.tls.inp = inp;
711 	params.tls.tls = tls;
712 	INP_RUNLOCK(inp);
713 
714 	if (ifp->if_snd_tag_alloc == NULL) {
715 		error = EOPNOTSUPP;
716 		goto out;
717 	}
718 	if ((ifp->if_capenable & IFCAP_NOMAP) == 0) {
719 		error = EOPNOTSUPP;
720 		goto out;
721 	}
722 	if (inp->inp_vflag & INP_IPV6) {
723 		if ((ifp->if_capenable & IFCAP_TXTLS6) == 0) {
724 			error = EOPNOTSUPP;
725 			goto out;
726 		}
727 	} else {
728 		if ((ifp->if_capenable & IFCAP_TXTLS4) == 0) {
729 			error = EOPNOTSUPP;
730 			goto out;
731 		}
732 	}
733 	error = ifp->if_snd_tag_alloc(ifp, &params, mstp);
734 out:
735 	if_rele(ifp);
736 	return (error);
737 }
738 
739 static int
740 ktls_try_ifnet(struct socket *so, struct ktls_session *tls, bool force)
741 {
742 	struct m_snd_tag *mst;
743 	int error;
744 
745 	error = ktls_alloc_snd_tag(so->so_pcb, tls, force, &mst);
746 	if (error == 0) {
747 		tls->snd_tag = mst;
748 		switch (tls->params.cipher_algorithm) {
749 		case CRYPTO_AES_CBC:
750 			counter_u64_add(ktls_ifnet_cbc, 1);
751 			break;
752 		case CRYPTO_AES_NIST_GCM_16:
753 			counter_u64_add(ktls_ifnet_gcm, 1);
754 			break;
755 		}
756 	}
757 	return (error);
758 }
759 
760 static int
761 ktls_try_sw(struct socket *so, struct ktls_session *tls)
762 {
763 	struct rm_priotracker prio;
764 	struct ktls_crypto_backend *be;
765 
766 	/*
767 	 * Choose the best software crypto backend.  Backends are
768 	 * stored in sorted priority order (larget value == most
769 	 * important at the head of the list), so this just stops on
770 	 * the first backend that claims the session by returning
771 	 * success.
772 	 */
773 	if (ktls_allow_unload)
774 		rm_rlock(&ktls_backends_lock, &prio);
775 	LIST_FOREACH(be, &ktls_backends, next) {
776 		if (be->try(so, tls) == 0)
777 			break;
778 		KASSERT(tls->cipher == NULL,
779 		    ("ktls backend leaked a cipher pointer"));
780 	}
781 	if (be != NULL) {
782 		if (ktls_allow_unload)
783 			be->use_count++;
784 		tls->be = be;
785 	}
786 	if (ktls_allow_unload)
787 		rm_runlock(&ktls_backends_lock, &prio);
788 	if (be == NULL)
789 		return (EOPNOTSUPP);
790 	switch (tls->params.cipher_algorithm) {
791 	case CRYPTO_AES_CBC:
792 		counter_u64_add(ktls_sw_cbc, 1);
793 		break;
794 	case CRYPTO_AES_NIST_GCM_16:
795 		counter_u64_add(ktls_sw_gcm, 1);
796 		break;
797 	}
798 	return (0);
799 }
800 
801 int
802 ktls_enable_tx(struct socket *so, struct tls_enable *en)
803 {
804 	struct ktls_session *tls;
805 	int error;
806 
807 	if (!ktls_offload_enable)
808 		return (ENOTSUP);
809 
810 	counter_u64_add(ktls_offload_enable_calls, 1);
811 
812 	/*
813 	 * This should always be true since only the TCP socket option
814 	 * invokes this function.
815 	 */
816 	if (so->so_proto->pr_protocol != IPPROTO_TCP)
817 		return (EINVAL);
818 
819 	/*
820 	 * XXX: Don't overwrite existing sessions.  We should permit
821 	 * this to support rekeying in the future.
822 	 */
823 	if (so->so_snd.sb_tls_info != NULL)
824 		return (EALREADY);
825 
826 	if (en->cipher_algorithm == CRYPTO_AES_CBC && !ktls_cbc_enable)
827 		return (ENOTSUP);
828 
829 	/* TLS requires ext pgs */
830 	if (mb_use_ext_pgs == 0)
831 		return (ENXIO);
832 
833 	error = ktls_create_session(so, en, &tls);
834 	if (error)
835 		return (error);
836 
837 	/* Prefer ifnet TLS over software TLS. */
838 	error = ktls_try_ifnet(so, tls, false);
839 	if (error)
840 		error = ktls_try_sw(so, tls);
841 
842 	if (error) {
843 		ktls_cleanup(tls);
844 		return (error);
845 	}
846 
847 	error = sblock(&so->so_snd, SBL_WAIT);
848 	if (error) {
849 		ktls_cleanup(tls);
850 		return (error);
851 	}
852 
853 	SOCKBUF_LOCK(&so->so_snd);
854 	so->so_snd.sb_tls_info = tls;
855 	if (tls->sw_encrypt == NULL)
856 		so->so_snd.sb_flags |= SB_TLS_IFNET;
857 	SOCKBUF_UNLOCK(&so->so_snd);
858 	sbunlock(&so->so_snd);
859 
860 	counter_u64_add(ktls_offload_total, 1);
861 
862 	return (0);
863 }
864 
865 int
866 ktls_get_tx_mode(struct socket *so)
867 {
868 	struct ktls_session *tls;
869 	struct inpcb *inp;
870 	int mode;
871 
872 	inp = so->so_pcb;
873 	INP_WLOCK_ASSERT(inp);
874 	SOCKBUF_LOCK(&so->so_snd);
875 	tls = so->so_snd.sb_tls_info;
876 	if (tls == NULL)
877 		mode = TCP_TLS_MODE_NONE;
878 	else if (tls->sw_encrypt != NULL)
879 		mode = TCP_TLS_MODE_SW;
880 	else
881 		mode = TCP_TLS_MODE_IFNET;
882 	SOCKBUF_UNLOCK(&so->so_snd);
883 	return (mode);
884 }
885 
886 /*
887  * Switch between SW and ifnet TLS sessions as requested.
888  */
889 int
890 ktls_set_tx_mode(struct socket *so, int mode)
891 {
892 	struct ktls_session *tls, *tls_new;
893 	struct inpcb *inp;
894 	int error;
895 
896 	MPASS(mode == TCP_TLS_MODE_SW || mode == TCP_TLS_MODE_IFNET);
897 
898 	inp = so->so_pcb;
899 	INP_WLOCK_ASSERT(inp);
900 	SOCKBUF_LOCK(&so->so_snd);
901 	tls = so->so_snd.sb_tls_info;
902 	if (tls == NULL) {
903 		SOCKBUF_UNLOCK(&so->so_snd);
904 		return (0);
905 	}
906 
907 	if ((tls->sw_encrypt != NULL && mode == TCP_TLS_MODE_SW) ||
908 	    (tls->sw_encrypt == NULL && mode == TCP_TLS_MODE_IFNET)) {
909 		SOCKBUF_UNLOCK(&so->so_snd);
910 		return (0);
911 	}
912 
913 	tls = ktls_hold(tls);
914 	SOCKBUF_UNLOCK(&so->so_snd);
915 	INP_WUNLOCK(inp);
916 
917 	tls_new = ktls_clone_session(tls);
918 
919 	if (mode == TCP_TLS_MODE_IFNET)
920 		error = ktls_try_ifnet(so, tls_new, true);
921 	else
922 		error = ktls_try_sw(so, tls_new);
923 	if (error) {
924 		counter_u64_add(ktls_switch_failed, 1);
925 		ktls_free(tls_new);
926 		ktls_free(tls);
927 		INP_WLOCK(inp);
928 		return (error);
929 	}
930 
931 	error = sblock(&so->so_snd, SBL_WAIT);
932 	if (error) {
933 		counter_u64_add(ktls_switch_failed, 1);
934 		ktls_free(tls_new);
935 		ktls_free(tls);
936 		INP_WLOCK(inp);
937 		return (error);
938 	}
939 
940 	/*
941 	 * If we raced with another session change, keep the existing
942 	 * session.
943 	 */
944 	if (tls != so->so_snd.sb_tls_info) {
945 		counter_u64_add(ktls_switch_failed, 1);
946 		sbunlock(&so->so_snd);
947 		ktls_free(tls_new);
948 		ktls_free(tls);
949 		INP_WLOCK(inp);
950 		return (EBUSY);
951 	}
952 
953 	SOCKBUF_LOCK(&so->so_snd);
954 	so->so_snd.sb_tls_info = tls_new;
955 	if (tls_new->sw_encrypt == NULL)
956 		so->so_snd.sb_flags |= SB_TLS_IFNET;
957 	SOCKBUF_UNLOCK(&so->so_snd);
958 	sbunlock(&so->so_snd);
959 
960 	/*
961 	 * Drop two references on 'tls'.  The first is for the
962 	 * ktls_hold() above.  The second drops the reference from the
963 	 * socket buffer.
964 	 */
965 	KASSERT(tls->refcount >= 2, ("too few references on old session"));
966 	ktls_free(tls);
967 	ktls_free(tls);
968 
969 	if (mode == TCP_TLS_MODE_IFNET)
970 		counter_u64_add(ktls_switch_to_ifnet, 1);
971 	else
972 		counter_u64_add(ktls_switch_to_sw, 1);
973 
974 	INP_WLOCK(inp);
975 	return (0);
976 }
977 
978 /*
979  * Try to allocate a new TLS send tag.  This task is scheduled when
980  * ip_output detects a route change while trying to transmit a packet
981  * holding a TLS record.  If a new tag is allocated, replace the tag
982  * in the TLS session.  Subsequent packets on the connection will use
983  * the new tag.  If a new tag cannot be allocated, drop the
984  * connection.
985  */
986 static void
987 ktls_reset_send_tag(void *context, int pending)
988 {
989 	struct epoch_tracker et;
990 	struct ktls_session *tls;
991 	struct m_snd_tag *old, *new;
992 	struct inpcb *inp;
993 	struct tcpcb *tp;
994 	int error;
995 
996 	MPASS(pending == 1);
997 
998 	tls = context;
999 	inp = tls->inp;
1000 
1001 	/*
1002 	 * Free the old tag first before allocating a new one.
1003 	 * ip[6]_output_send() will treat a NULL send tag the same as
1004 	 * an ifp mismatch and drop packets until a new tag is
1005 	 * allocated.
1006 	 *
1007 	 * Write-lock the INP when changing tls->snd_tag since
1008 	 * ip[6]_output_send() holds a read-lock when reading the
1009 	 * pointer.
1010 	 */
1011 	INP_WLOCK(inp);
1012 	old = tls->snd_tag;
1013 	tls->snd_tag = NULL;
1014 	INP_WUNLOCK(inp);
1015 	if (old != NULL)
1016 		m_snd_tag_rele(old);
1017 
1018 	error = ktls_alloc_snd_tag(inp, tls, true, &new);
1019 
1020 	if (error == 0) {
1021 		INP_WLOCK(inp);
1022 		tls->snd_tag = new;
1023 		mtx_pool_lock(mtxpool_sleep, tls);
1024 		tls->reset_pending = false;
1025 		mtx_pool_unlock(mtxpool_sleep, tls);
1026 		if (!in_pcbrele_wlocked(inp))
1027 			INP_WUNLOCK(inp);
1028 
1029 		counter_u64_add(ktls_ifnet_reset, 1);
1030 
1031 		/*
1032 		 * XXX: Should we kick tcp_output explicitly now that
1033 		 * the send tag is fixed or just rely on timers?
1034 		 */
1035 	} else {
1036 		INP_INFO_RLOCK_ET(&V_tcbinfo, et);
1037 		INP_WLOCK(inp);
1038 		if (!in_pcbrele_wlocked(inp)) {
1039 			if (!(inp->inp_flags & INP_TIMEWAIT) &&
1040 			    !(inp->inp_flags & INP_DROPPED)) {
1041 				tp = intotcpcb(inp);
1042 				tp = tcp_drop(tp, ECONNABORTED);
1043 				if (tp != NULL)
1044 					INP_WUNLOCK(inp);
1045 				counter_u64_add(ktls_ifnet_reset_dropped, 1);
1046 			} else
1047 				INP_WUNLOCK(inp);
1048 		}
1049 		INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
1050 
1051 		counter_u64_add(ktls_ifnet_reset_failed, 1);
1052 
1053 		/*
1054 		 * Leave reset_pending true to avoid future tasks while
1055 		 * the socket goes away.
1056 		 */
1057 	}
1058 
1059 	ktls_free(tls);
1060 }
1061 
1062 int
1063 ktls_output_eagain(struct inpcb *inp, struct ktls_session *tls)
1064 {
1065 
1066 	if (inp == NULL)
1067 		return (ENOBUFS);
1068 
1069 	INP_LOCK_ASSERT(inp);
1070 
1071 	/*
1072 	 * See if we should schedule a task to update the send tag for
1073 	 * this session.
1074 	 */
1075 	mtx_pool_lock(mtxpool_sleep, tls);
1076 	if (!tls->reset_pending) {
1077 		(void) ktls_hold(tls);
1078 		in_pcbref(inp);
1079 		tls->inp = inp;
1080 		tls->reset_pending = true;
1081 		taskqueue_enqueue(taskqueue_thread, &tls->reset_tag_task);
1082 	}
1083 	mtx_pool_unlock(mtxpool_sleep, tls);
1084 	return (ENOBUFS);
1085 }
1086 #endif
1087 
1088 void
1089 ktls_destroy(struct ktls_session *tls)
1090 {
1091 	struct rm_priotracker prio;
1092 
1093 	ktls_cleanup(tls);
1094 	if (tls->be != NULL && ktls_allow_unload) {
1095 		rm_rlock(&ktls_backends_lock, &prio);
1096 		tls->be->use_count--;
1097 		rm_runlock(&ktls_backends_lock, &prio);
1098 	}
1099 	uma_zfree(ktls_session_zone, tls);
1100 }
1101 
1102 void
1103 ktls_seq(struct sockbuf *sb, struct mbuf *m)
1104 {
1105 	struct mbuf_ext_pgs *pgs;
1106 	struct tls_record_layer *tlshdr;
1107 	uint64_t seqno;
1108 
1109 	for (; m != NULL; m = m->m_next) {
1110 		KASSERT((m->m_flags & M_NOMAP) != 0,
1111 		    ("ktls_seq: mapped mbuf %p", m));
1112 
1113 		pgs = m->m_ext.ext_pgs;
1114 		pgs->seqno = sb->sb_tls_seqno;
1115 
1116 		/*
1117 		 * Store the sequence number in the TLS header as the
1118 		 * explicit part of the IV for GCM.
1119 		 */
1120 		if (pgs->tls->params.cipher_algorithm ==
1121 		    CRYPTO_AES_NIST_GCM_16) {
1122 			tlshdr = (void *)pgs->hdr;
1123 			seqno = htobe64(pgs->seqno);
1124 			memcpy(tlshdr + 1, &seqno, sizeof(seqno));
1125 		}
1126 		sb->sb_tls_seqno++;
1127 	}
1128 }
1129 
1130 /*
1131  * Add TLS framing (headers and trailers) to a chain of mbufs.  Each
1132  * mbuf in the chain must be an unmapped mbuf.  The payload of the
1133  * mbuf must be populated with the payload of each TLS record.
1134  *
1135  * The record_type argument specifies the TLS record type used when
1136  * populating the TLS header.
1137  *
1138  * The enq_count argument on return is set to the number of pages of
1139  * payload data for this entire chain that need to be encrypted via SW
1140  * encryption.  The returned value should be passed to ktls_enqueue
1141  * when scheduling encryption of this chain of mbufs.
1142  */
1143 int
1144 ktls_frame(struct mbuf *top, struct ktls_session *tls, int *enq_cnt,
1145     uint8_t record_type)
1146 {
1147 	struct tls_record_layer *tlshdr;
1148 	struct mbuf *m;
1149 	struct mbuf_ext_pgs *pgs;
1150 	uint16_t tls_len;
1151 	int maxlen;
1152 
1153 	maxlen = tls->params.max_frame_len;
1154 	*enq_cnt = 0;
1155 	for (m = top; m != NULL; m = m->m_next) {
1156 		/*
1157 		 * All mbufs in the chain should be non-empty TLS
1158 		 * records whose payload does not exceed the maximum
1159 		 * frame length.
1160 		 */
1161 		if (m->m_len > maxlen || m->m_len == 0)
1162 			return (EINVAL);
1163 		tls_len = m->m_len;
1164 
1165 		/*
1166 		 * TLS frames require unmapped mbufs to store session
1167 		 * info.
1168 		 */
1169 		KASSERT((m->m_flags & M_NOMAP) != 0,
1170 		    ("ktls_frame: mapped mbuf %p (top = %p)\n", m, top));
1171 
1172 		pgs = m->m_ext.ext_pgs;
1173 
1174 		/* Save a reference to the session. */
1175 		pgs->tls = ktls_hold(tls);
1176 
1177 		pgs->hdr_len = tls->params.tls_hlen;
1178 		pgs->trail_len = tls->params.tls_tlen;
1179 		if (tls->params.cipher_algorithm == CRYPTO_AES_CBC) {
1180 			int bs, delta;
1181 
1182 			/*
1183 			 * AES-CBC pads messages to a multiple of the
1184 			 * block size.  Note that the padding is
1185 			 * applied after the digest and the encryption
1186 			 * is done on the "plaintext || mac || padding".
1187 			 * At least one byte of padding is always
1188 			 * present.
1189 			 *
1190 			 * Compute the final trailer length assuming
1191 			 * at most one block of padding.
1192 			 * tls->params.sb_tls_tlen is the maximum
1193 			 * possible trailer length (padding + digest).
1194 			 * delta holds the number of excess padding
1195 			 * bytes if the maximum were used.  Those
1196 			 * extra bytes are removed.
1197 			 */
1198 			bs = tls->params.tls_bs;
1199 			delta = (tls_len + tls->params.tls_tlen) & (bs - 1);
1200 			pgs->trail_len -= delta;
1201 		}
1202 		m->m_len += pgs->hdr_len + pgs->trail_len;
1203 
1204 		/* Populate the TLS header. */
1205 		tlshdr = (void *)pgs->hdr;
1206 		tlshdr->tls_vmajor = tls->params.tls_vmajor;
1207 
1208 		/*
1209 		 * TLS 1.3 masquarades as TLS 1.2 with a record type
1210 		 * of TLS_RLTYPE_APP.
1211 		 */
1212 		if (tls->params.tls_vminor == TLS_MINOR_VER_THREE &&
1213 		    tls->params.tls_vmajor == TLS_MAJOR_VER_ONE) {
1214 			tlshdr->tls_vminor = TLS_MINOR_VER_TWO;
1215 			tlshdr->tls_type = TLS_RLTYPE_APP;
1216 			/* save the real record type for later */
1217 			pgs->record_type = record_type;
1218 		} else {
1219 			tlshdr->tls_vminor = tls->params.tls_vminor;
1220 			tlshdr->tls_type = record_type;
1221 		}
1222 		tlshdr->tls_length = htons(m->m_len - sizeof(*tlshdr));
1223 
1224 		/*
1225 		 * For GCM, the sequence number is stored in the
1226 		 * header by ktls_seq().  For CBC, a random nonce is
1227 		 * inserted for TLS 1.1+.
1228 		 */
1229 		if (tls->params.cipher_algorithm == CRYPTO_AES_CBC &&
1230 		    tls->params.tls_vminor >= TLS_MINOR_VER_ONE)
1231 			arc4rand(tlshdr + 1, AES_BLOCK_LEN, 0);
1232 
1233 		/*
1234 		 * When using SW encryption, mark the mbuf not ready.
1235 		 * It will be marked ready via sbready() after the
1236 		 * record has been encrypted.
1237 		 *
1238 		 * When using ifnet TLS, unencrypted TLS records are
1239 		 * sent down the stack to the NIC.
1240 		 */
1241 		if (tls->sw_encrypt != NULL) {
1242 			m->m_flags |= M_NOTREADY;
1243 			pgs->nrdy = pgs->npgs;
1244 			*enq_cnt += pgs->npgs;
1245 		}
1246 	}
1247 	return (0);
1248 }
1249 
1250 void
1251 ktls_enqueue_to_free(struct mbuf_ext_pgs *pgs)
1252 {
1253 	struct ktls_wq *wq;
1254 	bool running;
1255 
1256 	/* Mark it for freeing. */
1257 	pgs->mbuf = NULL;
1258 	wq = &ktls_wq[pgs->tls->wq_index];
1259 	mtx_lock(&wq->mtx);
1260 	STAILQ_INSERT_TAIL(&wq->head, pgs, stailq);
1261 	running = wq->running;
1262 	mtx_unlock(&wq->mtx);
1263 	if (!running)
1264 		wakeup(wq);
1265 }
1266 
1267 void
1268 ktls_enqueue(struct mbuf *m, struct socket *so, int page_count)
1269 {
1270 	struct mbuf_ext_pgs *pgs;
1271 	struct ktls_wq *wq;
1272 	bool running;
1273 
1274 	KASSERT(((m->m_flags & (M_NOMAP | M_NOTREADY)) ==
1275 	    (M_NOMAP | M_NOTREADY)),
1276 	    ("ktls_enqueue: %p not unready & nomap mbuf\n", m));
1277 	KASSERT(page_count != 0, ("enqueueing TLS mbuf with zero page count"));
1278 
1279 	pgs = m->m_ext.ext_pgs;
1280 
1281 	KASSERT(pgs->tls->sw_encrypt != NULL, ("ifnet TLS mbuf"));
1282 
1283 	pgs->enc_cnt = page_count;
1284 	pgs->mbuf = m;
1285 
1286 	/*
1287 	 * Save a pointer to the socket.  The caller is responsible
1288 	 * for taking an additional reference via soref().
1289 	 */
1290 	pgs->so = so;
1291 
1292 	wq = &ktls_wq[pgs->tls->wq_index];
1293 	mtx_lock(&wq->mtx);
1294 	STAILQ_INSERT_TAIL(&wq->head, pgs, stailq);
1295 	running = wq->running;
1296 	mtx_unlock(&wq->mtx);
1297 	if (!running)
1298 		wakeup(wq);
1299 	counter_u64_add(ktls_cnt_on, 1);
1300 }
1301 
1302 static __noinline void
1303 ktls_encrypt(struct mbuf_ext_pgs *pgs)
1304 {
1305 	struct ktls_session *tls;
1306 	struct socket *so;
1307 	struct mbuf *m, *top;
1308 	vm_paddr_t parray[1 + btoc(TLS_MAX_MSG_SIZE_V10_2)];
1309 	struct iovec src_iov[1 + btoc(TLS_MAX_MSG_SIZE_V10_2)];
1310 	struct iovec dst_iov[1 + btoc(TLS_MAX_MSG_SIZE_V10_2)];
1311 	vm_page_t pg;
1312 	int error, i, len, npages, off, total_pages;
1313 	bool is_anon;
1314 
1315 	so = pgs->so;
1316 	tls = pgs->tls;
1317 	top = pgs->mbuf;
1318 	KASSERT(tls != NULL, ("tls = NULL, top = %p, pgs = %p\n", top, pgs));
1319 	KASSERT(so != NULL, ("so = NULL, top = %p, pgs = %p\n", top, pgs));
1320 #ifdef INVARIANTS
1321 	pgs->so = NULL;
1322 	pgs->mbuf = NULL;
1323 #endif
1324 	total_pages = pgs->enc_cnt;
1325 	npages = 0;
1326 
1327 	/*
1328 	 * Encrypt the TLS records in the chain of mbufs starting with
1329 	 * 'top'.  'total_pages' gives us a total count of pages and is
1330 	 * used to know when we have finished encrypting the TLS
1331 	 * records originally queued with 'top'.
1332 	 *
1333 	 * NB: These mbufs are queued in the socket buffer and
1334 	 * 'm_next' is traversing the mbufs in the socket buffer.  The
1335 	 * socket buffer lock is not held while traversing this chain.
1336 	 * Since the mbufs are all marked M_NOTREADY their 'm_next'
1337 	 * pointers should be stable.  However, the 'm_next' of the
1338 	 * last mbuf encrypted is not necessarily NULL.  It can point
1339 	 * to other mbufs appended while 'top' was on the TLS work
1340 	 * queue.
1341 	 *
1342 	 * Each mbuf holds an entire TLS record.
1343 	 */
1344 	error = 0;
1345 	for (m = top; npages != total_pages; m = m->m_next) {
1346 		pgs = m->m_ext.ext_pgs;
1347 
1348 		KASSERT(pgs->tls == tls,
1349 		    ("different TLS sessions in a single mbuf chain: %p vs %p",
1350 		    tls, pgs->tls));
1351 		KASSERT((m->m_flags & (M_NOMAP | M_NOTREADY)) ==
1352 		    (M_NOMAP | M_NOTREADY),
1353 		    ("%p not unready & nomap mbuf (top = %p)\n", m, top));
1354 		KASSERT(npages + pgs->npgs <= total_pages,
1355 		    ("page count mismatch: top %p, total_pages %d, m %p", top,
1356 		    total_pages, m));
1357 
1358 		/*
1359 		 * Generate source and destination ivoecs to pass to
1360 		 * the SW encryption backend.  For writable mbufs, the
1361 		 * destination iovec is a copy of the source and
1362 		 * encryption is done in place.  For file-backed mbufs
1363 		 * (from sendfile), anonymous wired pages are
1364 		 * allocated and assigned to the destination iovec.
1365 		 */
1366 		is_anon = (pgs->flags & MBUF_PEXT_FLAG_ANON) != 0;
1367 
1368 		off = pgs->first_pg_off;
1369 		for (i = 0; i < pgs->npgs; i++, off = 0) {
1370 			len = mbuf_ext_pg_len(pgs, i, off);
1371 			src_iov[i].iov_len = len;
1372 			src_iov[i].iov_base =
1373 			    (char *)(void *)PHYS_TO_DMAP(pgs->pa[i]) + off;
1374 
1375 			if (is_anon) {
1376 				dst_iov[i].iov_base = src_iov[i].iov_base;
1377 				dst_iov[i].iov_len = src_iov[i].iov_len;
1378 				continue;
1379 			}
1380 retry_page:
1381 			pg = vm_page_alloc(NULL, 0, VM_ALLOC_NORMAL |
1382 			    VM_ALLOC_NOOBJ | VM_ALLOC_NODUMP | VM_ALLOC_WIRED);
1383 			if (pg == NULL) {
1384 				vm_wait(NULL);
1385 				goto retry_page;
1386 			}
1387 			parray[i] = VM_PAGE_TO_PHYS(pg);
1388 			dst_iov[i].iov_base =
1389 			    (char *)(void *)PHYS_TO_DMAP(parray[i]) + off;
1390 			dst_iov[i].iov_len = len;
1391 		}
1392 
1393 		npages += i;
1394 
1395 		error = (*tls->sw_encrypt)(tls,
1396 		    (const struct tls_record_layer *)pgs->hdr,
1397 		    pgs->trail, src_iov, dst_iov, i, pgs->seqno,
1398 		    pgs->record_type);
1399 		if (error) {
1400 			counter_u64_add(ktls_offload_failed_crypto, 1);
1401 			break;
1402 		}
1403 
1404 		/*
1405 		 * For file-backed mbufs, release the file-backed
1406 		 * pages and replace them in the ext_pgs array with
1407 		 * the anonymous wired pages allocated above.
1408 		 */
1409 		if (!is_anon) {
1410 			/* Free the old pages. */
1411 			m->m_ext.ext_free(m);
1412 
1413 			/* Replace them with the new pages. */
1414 			for (i = 0; i < pgs->npgs; i++)
1415 				pgs->pa[i] = parray[i];
1416 
1417 			/* Use the basic free routine. */
1418 			m->m_ext.ext_free = mb_free_mext_pgs;
1419 
1420 			/* Pages are now writable. */
1421 			pgs->flags |= MBUF_PEXT_FLAG_ANON;
1422 		}
1423 
1424 		/*
1425 		 * Drop a reference to the session now that it is no
1426 		 * longer needed.  Existing code depends on encrypted
1427 		 * records having no associated session vs
1428 		 * yet-to-be-encrypted records having an associated
1429 		 * session.
1430 		 */
1431 		pgs->tls = NULL;
1432 		ktls_free(tls);
1433 	}
1434 
1435 	CURVNET_SET(so->so_vnet);
1436 	if (error == 0) {
1437 		(void)(*so->so_proto->pr_usrreqs->pru_ready)(so, top, npages);
1438 	} else {
1439 		so->so_proto->pr_usrreqs->pru_abort(so);
1440 		so->so_error = EIO;
1441 		mb_free_notready(top, total_pages);
1442 	}
1443 
1444 	SOCK_LOCK(so);
1445 	sorele(so);
1446 	CURVNET_RESTORE();
1447 }
1448 
1449 static void
1450 ktls_work_thread(void *ctx)
1451 {
1452 	struct ktls_wq *wq = ctx;
1453 	struct mbuf_ext_pgs *p, *n;
1454 	struct ktls_session *tls;
1455 	STAILQ_HEAD(, mbuf_ext_pgs) local_head;
1456 
1457 #if defined(__aarch64__) || defined(__amd64__) || defined(__i386__)
1458 	fpu_kern_thread(0);
1459 #endif
1460 	for (;;) {
1461 		mtx_lock(&wq->mtx);
1462 		while (STAILQ_EMPTY(&wq->head)) {
1463 			wq->running = false;
1464 			mtx_sleep(wq, &wq->mtx, 0, "-", 0);
1465 			wq->running = true;
1466 		}
1467 
1468 		STAILQ_INIT(&local_head);
1469 		STAILQ_CONCAT(&local_head, &wq->head);
1470 		mtx_unlock(&wq->mtx);
1471 
1472 		STAILQ_FOREACH_SAFE(p, &local_head, stailq, n) {
1473 			if (p->mbuf != NULL) {
1474 				ktls_encrypt(p);
1475 				counter_u64_add(ktls_cnt_on, -1);
1476 			} else {
1477 				tls = p->tls;
1478 				ktls_free(tls);
1479 				uma_zfree(zone_extpgs, p);
1480 			}
1481 		}
1482 	}
1483 }
1484