xref: /freebsd/sys/kern/uipc_ktls.c (revision 85f87cf491bec6f90948a85b10f5523ea24db9e3)
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 #ifdef TCP_OFFLOAD
67 #include <netinet/tcp_offload.h>
68 #endif
69 #include <opencrypto/xform.h>
70 #include <vm/uma_dbg.h>
71 #include <vm/vm.h>
72 #include <vm/vm_pageout.h>
73 #include <vm/vm_page.h>
74 
75 struct ktls_wq {
76 	struct mtx	mtx;
77 	STAILQ_HEAD(, mbuf_ext_pgs) head;
78 	bool		running;
79 } __aligned(CACHE_LINE_SIZE);
80 
81 static struct ktls_wq *ktls_wq;
82 static struct proc *ktls_proc;
83 LIST_HEAD(, ktls_crypto_backend) ktls_backends;
84 static struct rmlock ktls_backends_lock;
85 static uma_zone_t ktls_session_zone;
86 static uint16_t ktls_cpuid_lookup[MAXCPU];
87 
88 SYSCTL_NODE(_kern_ipc, OID_AUTO, tls, CTLFLAG_RW, 0,
89     "Kernel TLS offload");
90 SYSCTL_NODE(_kern_ipc_tls, OID_AUTO, stats, CTLFLAG_RW, 0,
91     "Kernel TLS offload stats");
92 
93 static int ktls_allow_unload;
94 SYSCTL_INT(_kern_ipc_tls, OID_AUTO, allow_unload, CTLFLAG_RDTUN,
95     &ktls_allow_unload, 0, "Allow software crypto modules to unload");
96 
97 #ifdef RSS
98 static int ktls_bind_threads = 1;
99 #else
100 static int ktls_bind_threads;
101 #endif
102 SYSCTL_INT(_kern_ipc_tls, OID_AUTO, bind_threads, CTLFLAG_RDTUN,
103     &ktls_bind_threads, 0,
104     "Bind crypto threads to cores or domains at boot");
105 
106 static u_int ktls_maxlen = 16384;
107 SYSCTL_UINT(_kern_ipc_tls, OID_AUTO, maxlen, CTLFLAG_RWTUN,
108     &ktls_maxlen, 0, "Maximum TLS record size");
109 
110 static int ktls_number_threads;
111 SYSCTL_INT(_kern_ipc_tls_stats, OID_AUTO, threads, CTLFLAG_RD,
112     &ktls_number_threads, 0,
113     "Number of TLS threads in thread-pool");
114 
115 static bool ktls_offload_enable;
116 SYSCTL_BOOL(_kern_ipc_tls, OID_AUTO, enable, CTLFLAG_RW,
117     &ktls_offload_enable, 0,
118     "Enable support for kernel TLS offload");
119 
120 static bool ktls_cbc_enable = true;
121 SYSCTL_BOOL(_kern_ipc_tls, OID_AUTO, cbc_enable, CTLFLAG_RW,
122     &ktls_cbc_enable, 1,
123     "Enable Support of AES-CBC crypto for kernel TLS");
124 
125 static counter_u64_t ktls_tasks_active;
126 SYSCTL_COUNTER_U64(_kern_ipc_tls, OID_AUTO, tasks_active, CTLFLAG_RD,
127     &ktls_tasks_active, "Number of active tasks");
128 
129 static counter_u64_t ktls_cnt_on;
130 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats, OID_AUTO, so_inqueue, CTLFLAG_RD,
131     &ktls_cnt_on, "Number of TLS records in queue to tasks for SW crypto");
132 
133 static counter_u64_t ktls_offload_total;
134 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats, OID_AUTO, offload_total,
135     CTLFLAG_RD, &ktls_offload_total,
136     "Total successful TLS setups (parameters set)");
137 
138 static counter_u64_t ktls_offload_enable_calls;
139 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats, OID_AUTO, enable_calls,
140     CTLFLAG_RD, &ktls_offload_enable_calls,
141     "Total number of TLS enable calls made");
142 
143 static counter_u64_t ktls_offload_active;
144 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats, OID_AUTO, active, CTLFLAG_RD,
145     &ktls_offload_active, "Total Active TLS sessions");
146 
147 static counter_u64_t ktls_offload_failed_crypto;
148 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats, OID_AUTO, failed_crypto, CTLFLAG_RD,
149     &ktls_offload_failed_crypto, "Total TLS crypto failures");
150 
151 static counter_u64_t ktls_switch_to_ifnet;
152 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats, OID_AUTO, switch_to_ifnet, CTLFLAG_RD,
153     &ktls_switch_to_ifnet, "TLS sessions switched from SW to ifnet");
154 
155 static counter_u64_t ktls_switch_to_sw;
156 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats, OID_AUTO, switch_to_sw, CTLFLAG_RD,
157     &ktls_switch_to_sw, "TLS sessions switched from ifnet to SW");
158 
159 static counter_u64_t ktls_switch_failed;
160 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats, OID_AUTO, switch_failed, CTLFLAG_RD,
161     &ktls_switch_failed, "TLS sessions unable to switch between SW and ifnet");
162 
163 SYSCTL_NODE(_kern_ipc_tls, OID_AUTO, sw, CTLFLAG_RD, 0,
164     "Software TLS session stats");
165 SYSCTL_NODE(_kern_ipc_tls, OID_AUTO, ifnet, CTLFLAG_RD, 0,
166     "Hardware (ifnet) TLS session stats");
167 #ifdef TCP_OFFLOAD
168 SYSCTL_NODE(_kern_ipc_tls, OID_AUTO, toe, CTLFLAG_RD, 0,
169     "TOE TLS session stats");
170 #endif
171 
172 static counter_u64_t ktls_sw_cbc;
173 SYSCTL_COUNTER_U64(_kern_ipc_tls_sw, OID_AUTO, cbc, CTLFLAG_RD, &ktls_sw_cbc,
174     "Active number of software TLS sessions using AES-CBC");
175 
176 static counter_u64_t ktls_sw_gcm;
177 SYSCTL_COUNTER_U64(_kern_ipc_tls_sw, OID_AUTO, gcm, CTLFLAG_RD, &ktls_sw_gcm,
178     "Active number of software TLS sessions using AES-GCM");
179 
180 static counter_u64_t ktls_ifnet_cbc;
181 SYSCTL_COUNTER_U64(_kern_ipc_tls_ifnet, OID_AUTO, cbc, CTLFLAG_RD,
182     &ktls_ifnet_cbc,
183     "Active number of ifnet TLS sessions using AES-CBC");
184 
185 static counter_u64_t ktls_ifnet_gcm;
186 SYSCTL_COUNTER_U64(_kern_ipc_tls_ifnet, OID_AUTO, gcm, CTLFLAG_RD,
187     &ktls_ifnet_gcm,
188     "Active number of ifnet TLS sessions using AES-GCM");
189 
190 static counter_u64_t ktls_ifnet_reset;
191 SYSCTL_COUNTER_U64(_kern_ipc_tls_ifnet, OID_AUTO, reset, CTLFLAG_RD,
192     &ktls_ifnet_reset, "TLS sessions updated to a new ifnet send tag");
193 
194 static counter_u64_t ktls_ifnet_reset_dropped;
195 SYSCTL_COUNTER_U64(_kern_ipc_tls_ifnet, OID_AUTO, reset_dropped, CTLFLAG_RD,
196     &ktls_ifnet_reset_dropped,
197     "TLS sessions dropped after failing to update ifnet send tag");
198 
199 static counter_u64_t ktls_ifnet_reset_failed;
200 SYSCTL_COUNTER_U64(_kern_ipc_tls_ifnet, OID_AUTO, reset_failed, CTLFLAG_RD,
201     &ktls_ifnet_reset_failed,
202     "TLS sessions that failed to allocate a new ifnet send tag");
203 
204 static int ktls_ifnet_permitted;
205 SYSCTL_UINT(_kern_ipc_tls_ifnet, OID_AUTO, permitted, CTLFLAG_RWTUN,
206     &ktls_ifnet_permitted, 1,
207     "Whether to permit hardware (ifnet) TLS sessions");
208 
209 #ifdef TCP_OFFLOAD
210 static counter_u64_t ktls_toe_cbc;
211 SYSCTL_COUNTER_U64(_kern_ipc_tls_toe, OID_AUTO, cbc, CTLFLAG_RD,
212     &ktls_toe_cbc,
213     "Active number of TOE TLS sessions using AES-CBC");
214 
215 static counter_u64_t ktls_toe_gcm;
216 SYSCTL_COUNTER_U64(_kern_ipc_tls_toe, OID_AUTO, gcm, CTLFLAG_RD,
217     &ktls_toe_gcm,
218     "Active number of TOE TLS sessions using AES-GCM");
219 #endif
220 
221 static MALLOC_DEFINE(M_KTLS, "ktls", "Kernel TLS");
222 
223 static void ktls_cleanup(struct ktls_session *tls);
224 #if defined(INET) || defined(INET6)
225 static void ktls_reset_send_tag(void *context, int pending);
226 #endif
227 static void ktls_work_thread(void *ctx);
228 
229 int
230 ktls_crypto_backend_register(struct ktls_crypto_backend *be)
231 {
232 	struct ktls_crypto_backend *curr_be, *tmp;
233 
234 	if (be->api_version != KTLS_API_VERSION) {
235 		printf("KTLS: API version mismatch (%d vs %d) for %s\n",
236 		    be->api_version, KTLS_API_VERSION,
237 		    be->name);
238 		return (EINVAL);
239 	}
240 
241 	rm_wlock(&ktls_backends_lock);
242 	printf("KTLS: Registering crypto method %s with prio %d\n",
243 	       be->name, be->prio);
244 	if (LIST_EMPTY(&ktls_backends)) {
245 		LIST_INSERT_HEAD(&ktls_backends, be, next);
246 	} else {
247 		LIST_FOREACH_SAFE(curr_be, &ktls_backends, next, tmp) {
248 			if (curr_be->prio < be->prio) {
249 				LIST_INSERT_BEFORE(curr_be, be, next);
250 				break;
251 			}
252 			if (LIST_NEXT(curr_be, next) == NULL) {
253 				LIST_INSERT_AFTER(curr_be, be, next);
254 				break;
255 			}
256 		}
257 	}
258 	rm_wunlock(&ktls_backends_lock);
259 	return (0);
260 }
261 
262 int
263 ktls_crypto_backend_deregister(struct ktls_crypto_backend *be)
264 {
265 	struct ktls_crypto_backend *tmp;
266 
267 	/*
268 	 * Don't error if the backend isn't registered.  This permits
269 	 * MOD_UNLOAD handlers to use this function unconditionally.
270 	 */
271 	rm_wlock(&ktls_backends_lock);
272 	LIST_FOREACH(tmp, &ktls_backends, next) {
273 		if (tmp == be)
274 			break;
275 	}
276 	if (tmp == NULL) {
277 		rm_wunlock(&ktls_backends_lock);
278 		return (0);
279 	}
280 
281 	if (!ktls_allow_unload) {
282 		rm_wunlock(&ktls_backends_lock);
283 		printf(
284 		    "KTLS: Deregistering crypto method %s is not supported\n",
285 		    be->name);
286 		return (EBUSY);
287 	}
288 
289 	if (be->use_count) {
290 		rm_wunlock(&ktls_backends_lock);
291 		return (EBUSY);
292 	}
293 
294 	LIST_REMOVE(be, next);
295 	rm_wunlock(&ktls_backends_lock);
296 	return (0);
297 }
298 
299 #if defined(INET) || defined(INET6)
300 static uint16_t
301 ktls_get_cpu(struct socket *so)
302 {
303 	struct inpcb *inp;
304 	uint16_t cpuid;
305 
306 	inp = sotoinpcb(so);
307 #ifdef RSS
308 	cpuid = rss_hash2cpuid(inp->inp_flowid, inp->inp_flowtype);
309 	if (cpuid != NETISR_CPUID_NONE)
310 		return (cpuid);
311 #endif
312 	/*
313 	 * Just use the flowid to shard connections in a repeatable
314 	 * fashion.  Note that some crypto backends rely on the
315 	 * serialization provided by having the same connection use
316 	 * the same queue.
317 	 */
318 	cpuid = ktls_cpuid_lookup[inp->inp_flowid % ktls_number_threads];
319 	return (cpuid);
320 }
321 #endif
322 
323 static void
324 ktls_init(void *dummy __unused)
325 {
326 	struct thread *td;
327 	struct pcpu *pc;
328 	cpuset_t mask;
329 	int error, i;
330 
331 	ktls_tasks_active = counter_u64_alloc(M_WAITOK);
332 	ktls_cnt_on = counter_u64_alloc(M_WAITOK);
333 	ktls_offload_total = counter_u64_alloc(M_WAITOK);
334 	ktls_offload_enable_calls = counter_u64_alloc(M_WAITOK);
335 	ktls_offload_active = counter_u64_alloc(M_WAITOK);
336 	ktls_offload_failed_crypto = counter_u64_alloc(M_WAITOK);
337 	ktls_switch_to_ifnet = counter_u64_alloc(M_WAITOK);
338 	ktls_switch_to_sw = counter_u64_alloc(M_WAITOK);
339 	ktls_switch_failed = counter_u64_alloc(M_WAITOK);
340 	ktls_sw_cbc = counter_u64_alloc(M_WAITOK);
341 	ktls_sw_gcm = counter_u64_alloc(M_WAITOK);
342 	ktls_ifnet_cbc = counter_u64_alloc(M_WAITOK);
343 	ktls_ifnet_gcm = counter_u64_alloc(M_WAITOK);
344 	ktls_ifnet_reset = counter_u64_alloc(M_WAITOK);
345 	ktls_ifnet_reset_dropped = counter_u64_alloc(M_WAITOK);
346 	ktls_ifnet_reset_failed = counter_u64_alloc(M_WAITOK);
347 #ifdef TCP_OFFLOAD
348 	ktls_toe_cbc = counter_u64_alloc(M_WAITOK);
349 	ktls_toe_gcm = counter_u64_alloc(M_WAITOK);
350 #endif
351 
352 	rm_init(&ktls_backends_lock, "ktls backends");
353 	LIST_INIT(&ktls_backends);
354 
355 	ktls_wq = malloc(sizeof(*ktls_wq) * (mp_maxid + 1), M_KTLS,
356 	    M_WAITOK | M_ZERO);
357 
358 	ktls_session_zone = uma_zcreate("ktls_session",
359 	    sizeof(struct ktls_session),
360 #ifdef INVARIANTS
361 	    trash_ctor, trash_dtor, trash_init, trash_fini,
362 #else
363 	    NULL, NULL, NULL, NULL,
364 #endif
365 	    UMA_ALIGN_CACHE, 0);
366 
367 	/*
368 	 * Initialize the workqueues to run the TLS work.  We create a
369 	 * work queue for each CPU.
370 	 */
371 	CPU_FOREACH(i) {
372 		STAILQ_INIT(&ktls_wq[i].head);
373 		mtx_init(&ktls_wq[i].mtx, "ktls work queue", NULL, MTX_DEF);
374 		error = kproc_kthread_add(ktls_work_thread, &ktls_wq[i],
375 		    &ktls_proc, &td, 0, 0, "KTLS", "thr_%d", i);
376 		if (error)
377 			panic("Can't add KTLS thread %d error %d", i, error);
378 
379 		/*
380 		 * Bind threads to cores.  If ktls_bind_threads is >
381 		 * 1, then we bind to the NUMA domain.
382 		 */
383 		if (ktls_bind_threads) {
384 			if (ktls_bind_threads > 1) {
385 				pc = pcpu_find(i);
386 				CPU_COPY(&cpuset_domain[pc->pc_domain], &mask);
387 			} else {
388 				CPU_SETOF(i, &mask);
389 			}
390 			error = cpuset_setthread(td->td_tid, &mask);
391 			if (error)
392 				panic(
393 			    "Unable to bind KTLS thread for CPU %d error %d",
394 				     i, error);
395 		}
396 		ktls_cpuid_lookup[ktls_number_threads] = i;
397 		ktls_number_threads++;
398 	}
399 	printf("KTLS: Initialized %d threads\n", ktls_number_threads);
400 }
401 SYSINIT(ktls, SI_SUB_SMP + 1, SI_ORDER_ANY, ktls_init, NULL);
402 
403 #if defined(INET) || defined(INET6)
404 static int
405 ktls_create_session(struct socket *so, struct tls_enable *en,
406     struct ktls_session **tlsp)
407 {
408 	struct ktls_session *tls;
409 	int error;
410 
411 	/* Only TLS 1.0 - 1.2 are supported. */
412 	if (en->tls_vmajor != TLS_MAJOR_VER_ONE)
413 		return (EINVAL);
414 	if (en->tls_vminor < TLS_MINOR_VER_ZERO ||
415 	    en->tls_vminor > TLS_MINOR_VER_THREE)
416 		return (EINVAL);
417 
418 	if (en->auth_key_len < 0 || en->auth_key_len > TLS_MAX_PARAM_SIZE)
419 		return (EINVAL);
420 	if (en->cipher_key_len < 0 || en->cipher_key_len > TLS_MAX_PARAM_SIZE)
421 		return (EINVAL);
422 	if (en->iv_len < 0 || en->iv_len > sizeof(tls->params.iv))
423 		return (EINVAL);
424 
425 	/* All supported algorithms require a cipher key. */
426 	if (en->cipher_key_len == 0)
427 		return (EINVAL);
428 
429 	/* No flags are currently supported. */
430 	if (en->flags != 0)
431 		return (EINVAL);
432 
433 	/* Common checks for supported algorithms. */
434 	switch (en->cipher_algorithm) {
435 	case CRYPTO_AES_NIST_GCM_16:
436 		/*
437 		 * auth_algorithm isn't used, but permit GMAC values
438 		 * for compatibility.
439 		 */
440 		switch (en->auth_algorithm) {
441 		case 0:
442 		case CRYPTO_AES_128_NIST_GMAC:
443 		case CRYPTO_AES_192_NIST_GMAC:
444 		case CRYPTO_AES_256_NIST_GMAC:
445 			break;
446 		default:
447 			return (EINVAL);
448 		}
449 		if (en->auth_key_len != 0)
450 			return (EINVAL);
451 		if ((en->tls_vminor == TLS_MINOR_VER_TWO &&
452 			en->iv_len != TLS_AEAD_GCM_LEN) ||
453 		    (en->tls_vminor == TLS_MINOR_VER_THREE &&
454 			en->iv_len != TLS_1_3_GCM_IV_LEN))
455 			return (EINVAL);
456 		break;
457 	case CRYPTO_AES_CBC:
458 		switch (en->auth_algorithm) {
459 		case CRYPTO_SHA1_HMAC:
460 			/*
461 			 * TLS 1.0 requires an implicit IV.  TLS 1.1+
462 			 * all use explicit IVs.
463 			 */
464 			if (en->tls_vminor == TLS_MINOR_VER_ZERO) {
465 				if (en->iv_len != TLS_CBC_IMPLICIT_IV_LEN)
466 					return (EINVAL);
467 				break;
468 			}
469 
470 			/* FALLTHROUGH */
471 		case CRYPTO_SHA2_256_HMAC:
472 		case CRYPTO_SHA2_384_HMAC:
473 			/* Ignore any supplied IV. */
474 			en->iv_len = 0;
475 			break;
476 		default:
477 			return (EINVAL);
478 		}
479 		if (en->auth_key_len == 0)
480 			return (EINVAL);
481 		break;
482 	default:
483 		return (EINVAL);
484 	}
485 
486 	tls = uma_zalloc(ktls_session_zone, M_WAITOK | M_ZERO);
487 
488 	counter_u64_add(ktls_offload_active, 1);
489 
490 	refcount_init(&tls->refcount, 1);
491 	TASK_INIT(&tls->reset_tag_task, 0, ktls_reset_send_tag, tls);
492 
493 	tls->wq_index = ktls_get_cpu(so);
494 
495 	tls->params.cipher_algorithm = en->cipher_algorithm;
496 	tls->params.auth_algorithm = en->auth_algorithm;
497 	tls->params.tls_vmajor = en->tls_vmajor;
498 	tls->params.tls_vminor = en->tls_vminor;
499 	tls->params.flags = en->flags;
500 	tls->params.max_frame_len = min(TLS_MAX_MSG_SIZE_V10_2, ktls_maxlen);
501 
502 	/* Set the header and trailer lengths. */
503 	tls->params.tls_hlen = sizeof(struct tls_record_layer);
504 	switch (en->cipher_algorithm) {
505 	case CRYPTO_AES_NIST_GCM_16:
506 		/*
507 		 * TLS 1.2 uses a 4 byte implicit IV with an explicit 8 byte
508 		 * nonce.  TLS 1.3 uses a 12 byte implicit IV.
509 		 */
510 		if (en->tls_vminor < TLS_MINOR_VER_THREE)
511 			tls->params.tls_hlen += sizeof(uint64_t);
512 		tls->params.tls_tlen = AES_GMAC_HASH_LEN;
513 
514 		/*
515 		 * TLS 1.3 includes optional padding which we
516 		 * do not support, and also puts the "real" record
517 		 * type at the end of the encrypted data.
518 		 */
519 		if (en->tls_vminor == TLS_MINOR_VER_THREE)
520 			tls->params.tls_tlen += sizeof(uint8_t);
521 
522 		tls->params.tls_bs = 1;
523 		break;
524 	case CRYPTO_AES_CBC:
525 		switch (en->auth_algorithm) {
526 		case CRYPTO_SHA1_HMAC:
527 			if (en->tls_vminor == TLS_MINOR_VER_ZERO) {
528 				/* Implicit IV, no nonce. */
529 			} else {
530 				tls->params.tls_hlen += AES_BLOCK_LEN;
531 			}
532 			tls->params.tls_tlen = AES_BLOCK_LEN +
533 			    SHA1_HASH_LEN;
534 			break;
535 		case CRYPTO_SHA2_256_HMAC:
536 			tls->params.tls_hlen += AES_BLOCK_LEN;
537 			tls->params.tls_tlen = AES_BLOCK_LEN +
538 			    SHA2_256_HASH_LEN;
539 			break;
540 		case CRYPTO_SHA2_384_HMAC:
541 			tls->params.tls_hlen += AES_BLOCK_LEN;
542 			tls->params.tls_tlen = AES_BLOCK_LEN +
543 			    SHA2_384_HASH_LEN;
544 			break;
545 		default:
546 			panic("invalid hmac");
547 		}
548 		tls->params.tls_bs = AES_BLOCK_LEN;
549 		break;
550 	default:
551 		panic("invalid cipher");
552 	}
553 
554 	KASSERT(tls->params.tls_hlen <= MBUF_PEXT_HDR_LEN,
555 	    ("TLS header length too long: %d", tls->params.tls_hlen));
556 	KASSERT(tls->params.tls_tlen <= MBUF_PEXT_TRAIL_LEN,
557 	    ("TLS trailer length too long: %d", tls->params.tls_tlen));
558 
559 	if (en->auth_key_len != 0) {
560 		tls->params.auth_key_len = en->auth_key_len;
561 		tls->params.auth_key = malloc(en->auth_key_len, M_KTLS,
562 		    M_WAITOK);
563 		error = copyin(en->auth_key, tls->params.auth_key,
564 		    en->auth_key_len);
565 		if (error)
566 			goto out;
567 	}
568 
569 	tls->params.cipher_key_len = en->cipher_key_len;
570 	tls->params.cipher_key = malloc(en->cipher_key_len, M_KTLS, M_WAITOK);
571 	error = copyin(en->cipher_key, tls->params.cipher_key,
572 	    en->cipher_key_len);
573 	if (error)
574 		goto out;
575 
576 	/*
577 	 * This holds the implicit portion of the nonce for GCM and
578 	 * the initial implicit IV for TLS 1.0.  The explicit portions
579 	 * of the IV are generated in ktls_frame() and ktls_seq().
580 	 */
581 	if (en->iv_len != 0) {
582 		tls->params.iv_len = en->iv_len;
583 		error = copyin(en->iv, tls->params.iv, en->iv_len);
584 		if (error)
585 			goto out;
586 	}
587 
588 	*tlsp = tls;
589 	return (0);
590 
591 out:
592 	ktls_cleanup(tls);
593 	return (error);
594 }
595 
596 static struct ktls_session *
597 ktls_clone_session(struct ktls_session *tls)
598 {
599 	struct ktls_session *tls_new;
600 
601 	tls_new = uma_zalloc(ktls_session_zone, M_WAITOK | M_ZERO);
602 
603 	counter_u64_add(ktls_offload_active, 1);
604 
605 	refcount_init(&tls_new->refcount, 1);
606 
607 	/* Copy fields from existing session. */
608 	tls_new->params = tls->params;
609 	tls_new->wq_index = tls->wq_index;
610 
611 	/* Deep copy keys. */
612 	if (tls_new->params.auth_key != NULL) {
613 		tls_new->params.auth_key = malloc(tls->params.auth_key_len,
614 		    M_KTLS, M_WAITOK);
615 		memcpy(tls_new->params.auth_key, tls->params.auth_key,
616 		    tls->params.auth_key_len);
617 	}
618 
619 	tls_new->params.cipher_key = malloc(tls->params.cipher_key_len, M_KTLS,
620 	    M_WAITOK);
621 	memcpy(tls_new->params.cipher_key, tls->params.cipher_key,
622 	    tls->params.cipher_key_len);
623 
624 	return (tls_new);
625 }
626 #endif
627 
628 static void
629 ktls_cleanup(struct ktls_session *tls)
630 {
631 
632 	counter_u64_add(ktls_offload_active, -1);
633 	switch (tls->mode) {
634 	case TCP_TLS_MODE_SW:
635 		MPASS(tls->be != NULL);
636 		switch (tls->params.cipher_algorithm) {
637 		case CRYPTO_AES_CBC:
638 			counter_u64_add(ktls_sw_cbc, -1);
639 			break;
640 		case CRYPTO_AES_NIST_GCM_16:
641 			counter_u64_add(ktls_sw_gcm, -1);
642 			break;
643 		}
644 		tls->free(tls);
645 		break;
646 	case TCP_TLS_MODE_IFNET:
647 		switch (tls->params.cipher_algorithm) {
648 		case CRYPTO_AES_CBC:
649 			counter_u64_add(ktls_ifnet_cbc, -1);
650 			break;
651 		case CRYPTO_AES_NIST_GCM_16:
652 			counter_u64_add(ktls_ifnet_gcm, -1);
653 			break;
654 		}
655 		m_snd_tag_rele(tls->snd_tag);
656 		break;
657 #ifdef TCP_OFFLOAD
658 	case TCP_TLS_MODE_TOE:
659 		switch (tls->params.cipher_algorithm) {
660 		case CRYPTO_AES_CBC:
661 			counter_u64_add(ktls_toe_cbc, -1);
662 			break;
663 		case CRYPTO_AES_NIST_GCM_16:
664 			counter_u64_add(ktls_toe_gcm, -1);
665 			break;
666 		}
667 		break;
668 #endif
669 	}
670 	if (tls->params.auth_key != NULL) {
671 		explicit_bzero(tls->params.auth_key, tls->params.auth_key_len);
672 		free(tls->params.auth_key, M_KTLS);
673 		tls->params.auth_key = NULL;
674 		tls->params.auth_key_len = 0;
675 	}
676 	if (tls->params.cipher_key != NULL) {
677 		explicit_bzero(tls->params.cipher_key,
678 		    tls->params.cipher_key_len);
679 		free(tls->params.cipher_key, M_KTLS);
680 		tls->params.cipher_key = NULL;
681 		tls->params.cipher_key_len = 0;
682 	}
683 	explicit_bzero(tls->params.iv, sizeof(tls->params.iv));
684 }
685 
686 #if defined(INET) || defined(INET6)
687 
688 #ifdef TCP_OFFLOAD
689 static int
690 ktls_try_toe(struct socket *so, struct ktls_session *tls)
691 {
692 	struct inpcb *inp;
693 	struct tcpcb *tp;
694 	int error;
695 
696 	inp = so->so_pcb;
697 	INP_WLOCK(inp);
698 	if (inp->inp_flags2 & INP_FREED) {
699 		INP_WUNLOCK(inp);
700 		return (ECONNRESET);
701 	}
702 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
703 		INP_WUNLOCK(inp);
704 		return (ECONNRESET);
705 	}
706 	if (inp->inp_socket == NULL) {
707 		INP_WUNLOCK(inp);
708 		return (ECONNRESET);
709 	}
710 	tp = intotcpcb(inp);
711 	if (tp->tod == NULL) {
712 		INP_WUNLOCK(inp);
713 		return (EOPNOTSUPP);
714 	}
715 
716 	error = tcp_offload_alloc_tls_session(tp, tls);
717 	INP_WUNLOCK(inp);
718 	if (error == 0) {
719 		tls->mode = TCP_TLS_MODE_TOE;
720 		switch (tls->params.cipher_algorithm) {
721 		case CRYPTO_AES_CBC:
722 			counter_u64_add(ktls_toe_cbc, 1);
723 			break;
724 		case CRYPTO_AES_NIST_GCM_16:
725 			counter_u64_add(ktls_toe_gcm, 1);
726 			break;
727 		}
728 	}
729 	return (error);
730 }
731 #endif
732 
733 /*
734  * Common code used when first enabling ifnet TLS on a connection or
735  * when allocating a new ifnet TLS session due to a routing change.
736  * This function allocates a new TLS send tag on whatever interface
737  * the connection is currently routed over.
738  */
739 static int
740 ktls_alloc_snd_tag(struct inpcb *inp, struct ktls_session *tls, bool force,
741     struct m_snd_tag **mstp)
742 {
743 	union if_snd_tag_alloc_params params;
744 	struct ifnet *ifp;
745 	struct rtentry *rt;
746 	struct tcpcb *tp;
747 	int error;
748 
749 	INP_RLOCK(inp);
750 	if (inp->inp_flags2 & INP_FREED) {
751 		INP_RUNLOCK(inp);
752 		return (ECONNRESET);
753 	}
754 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
755 		INP_RUNLOCK(inp);
756 		return (ECONNRESET);
757 	}
758 	if (inp->inp_socket == NULL) {
759 		INP_RUNLOCK(inp);
760 		return (ECONNRESET);
761 	}
762 	tp = intotcpcb(inp);
763 
764 	/*
765 	 * Check administrative controls on ifnet TLS to determine if
766 	 * ifnet TLS should be denied.
767 	 *
768 	 * - Always permit 'force' requests.
769 	 * - ktls_ifnet_permitted == 0: always deny.
770 	 */
771 	if (!force && ktls_ifnet_permitted == 0) {
772 		INP_RUNLOCK(inp);
773 		return (ENXIO);
774 	}
775 
776 	/*
777 	 * XXX: Use the cached route in the inpcb to find the
778 	 * interface.  This should perhaps instead use
779 	 * rtalloc1_fib(dst, 0, 0, fibnum).  Since KTLS is only
780 	 * enabled after a connection has completed key negotiation in
781 	 * userland, the cached route will be present in practice.
782 	 */
783 	rt = inp->inp_route.ro_rt;
784 	if (rt == NULL || rt->rt_ifp == NULL) {
785 		INP_RUNLOCK(inp);
786 		return (ENXIO);
787 	}
788 	ifp = rt->rt_ifp;
789 	if_ref(ifp);
790 
791 	params.hdr.type = IF_SND_TAG_TYPE_TLS;
792 	params.hdr.flowid = inp->inp_flowid;
793 	params.hdr.flowtype = inp->inp_flowtype;
794 	params.tls.inp = inp;
795 	params.tls.tls = tls;
796 	INP_RUNLOCK(inp);
797 
798 	if (ifp->if_snd_tag_alloc == NULL) {
799 		error = EOPNOTSUPP;
800 		goto out;
801 	}
802 	if ((ifp->if_capenable & IFCAP_NOMAP) == 0) {
803 		error = EOPNOTSUPP;
804 		goto out;
805 	}
806 	if (inp->inp_vflag & INP_IPV6) {
807 		if ((ifp->if_capenable & IFCAP_TXTLS6) == 0) {
808 			error = EOPNOTSUPP;
809 			goto out;
810 		}
811 	} else {
812 		if ((ifp->if_capenable & IFCAP_TXTLS4) == 0) {
813 			error = EOPNOTSUPP;
814 			goto out;
815 		}
816 	}
817 	error = ifp->if_snd_tag_alloc(ifp, &params, mstp);
818 out:
819 	if_rele(ifp);
820 	return (error);
821 }
822 
823 static int
824 ktls_try_ifnet(struct socket *so, struct ktls_session *tls, bool force)
825 {
826 	struct m_snd_tag *mst;
827 	int error;
828 
829 	error = ktls_alloc_snd_tag(so->so_pcb, tls, force, &mst);
830 	if (error == 0) {
831 		tls->mode = TCP_TLS_MODE_IFNET;
832 		tls->snd_tag = mst;
833 		switch (tls->params.cipher_algorithm) {
834 		case CRYPTO_AES_CBC:
835 			counter_u64_add(ktls_ifnet_cbc, 1);
836 			break;
837 		case CRYPTO_AES_NIST_GCM_16:
838 			counter_u64_add(ktls_ifnet_gcm, 1);
839 			break;
840 		}
841 	}
842 	return (error);
843 }
844 
845 static int
846 ktls_try_sw(struct socket *so, struct ktls_session *tls)
847 {
848 	struct rm_priotracker prio;
849 	struct ktls_crypto_backend *be;
850 
851 	/*
852 	 * Choose the best software crypto backend.  Backends are
853 	 * stored in sorted priority order (larget value == most
854 	 * important at the head of the list), so this just stops on
855 	 * the first backend that claims the session by returning
856 	 * success.
857 	 */
858 	if (ktls_allow_unload)
859 		rm_rlock(&ktls_backends_lock, &prio);
860 	LIST_FOREACH(be, &ktls_backends, next) {
861 		if (be->try(so, tls) == 0)
862 			break;
863 		KASSERT(tls->cipher == NULL,
864 		    ("ktls backend leaked a cipher pointer"));
865 	}
866 	if (be != NULL) {
867 		if (ktls_allow_unload)
868 			be->use_count++;
869 		tls->be = be;
870 	}
871 	if (ktls_allow_unload)
872 		rm_runlock(&ktls_backends_lock, &prio);
873 	if (be == NULL)
874 		return (EOPNOTSUPP);
875 	tls->mode = TCP_TLS_MODE_SW;
876 	switch (tls->params.cipher_algorithm) {
877 	case CRYPTO_AES_CBC:
878 		counter_u64_add(ktls_sw_cbc, 1);
879 		break;
880 	case CRYPTO_AES_NIST_GCM_16:
881 		counter_u64_add(ktls_sw_gcm, 1);
882 		break;
883 	}
884 	return (0);
885 }
886 
887 int
888 ktls_enable_tx(struct socket *so, struct tls_enable *en)
889 {
890 	struct ktls_session *tls;
891 	int error;
892 
893 	if (!ktls_offload_enable)
894 		return (ENOTSUP);
895 
896 	counter_u64_add(ktls_offload_enable_calls, 1);
897 
898 	/*
899 	 * This should always be true since only the TCP socket option
900 	 * invokes this function.
901 	 */
902 	if (so->so_proto->pr_protocol != IPPROTO_TCP)
903 		return (EINVAL);
904 
905 	/*
906 	 * XXX: Don't overwrite existing sessions.  We should permit
907 	 * this to support rekeying in the future.
908 	 */
909 	if (so->so_snd.sb_tls_info != NULL)
910 		return (EALREADY);
911 
912 	if (en->cipher_algorithm == CRYPTO_AES_CBC && !ktls_cbc_enable)
913 		return (ENOTSUP);
914 
915 	/* TLS requires ext pgs */
916 	if (mb_use_ext_pgs == 0)
917 		return (ENXIO);
918 
919 	error = ktls_create_session(so, en, &tls);
920 	if (error)
921 		return (error);
922 
923 	/* Prefer TOE -> ifnet TLS -> software TLS. */
924 #ifdef TCP_OFFLOAD
925 	error = ktls_try_toe(so, tls);
926 	if (error)
927 #endif
928 		error = ktls_try_ifnet(so, tls, false);
929 	if (error)
930 		error = ktls_try_sw(so, tls);
931 
932 	if (error) {
933 		ktls_cleanup(tls);
934 		return (error);
935 	}
936 
937 	error = sblock(&so->so_snd, SBL_WAIT);
938 	if (error) {
939 		ktls_cleanup(tls);
940 		return (error);
941 	}
942 
943 	SOCKBUF_LOCK(&so->so_snd);
944 	so->so_snd.sb_tls_info = tls;
945 	if (tls->mode != TCP_TLS_MODE_SW)
946 		so->so_snd.sb_flags |= SB_TLS_IFNET;
947 	SOCKBUF_UNLOCK(&so->so_snd);
948 	sbunlock(&so->so_snd);
949 
950 	counter_u64_add(ktls_offload_total, 1);
951 
952 	return (0);
953 }
954 
955 int
956 ktls_get_tx_mode(struct socket *so)
957 {
958 	struct ktls_session *tls;
959 	struct inpcb *inp;
960 	int mode;
961 
962 	inp = so->so_pcb;
963 	INP_WLOCK_ASSERT(inp);
964 	SOCKBUF_LOCK(&so->so_snd);
965 	tls = so->so_snd.sb_tls_info;
966 	if (tls == NULL)
967 		mode = TCP_TLS_MODE_NONE;
968 	else
969 		mode = tls->mode;
970 	SOCKBUF_UNLOCK(&so->so_snd);
971 	return (mode);
972 }
973 
974 /*
975  * Switch between SW and ifnet TLS sessions as requested.
976  */
977 int
978 ktls_set_tx_mode(struct socket *so, int mode)
979 {
980 	struct ktls_session *tls, *tls_new;
981 	struct inpcb *inp;
982 	int error;
983 
984 	switch (mode) {
985 	case TCP_TLS_MODE_SW:
986 	case TCP_TLS_MODE_IFNET:
987 		break;
988 	default:
989 		return (EINVAL);
990 	}
991 
992 	inp = so->so_pcb;
993 	INP_WLOCK_ASSERT(inp);
994 	SOCKBUF_LOCK(&so->so_snd);
995 	tls = so->so_snd.sb_tls_info;
996 	if (tls == NULL) {
997 		SOCKBUF_UNLOCK(&so->so_snd);
998 		return (0);
999 	}
1000 
1001 	if (tls->mode == mode) {
1002 		SOCKBUF_UNLOCK(&so->so_snd);
1003 		return (0);
1004 	}
1005 
1006 	tls = ktls_hold(tls);
1007 	SOCKBUF_UNLOCK(&so->so_snd);
1008 	INP_WUNLOCK(inp);
1009 
1010 	tls_new = ktls_clone_session(tls);
1011 
1012 	if (mode == TCP_TLS_MODE_IFNET)
1013 		error = ktls_try_ifnet(so, tls_new, true);
1014 	else
1015 		error = ktls_try_sw(so, tls_new);
1016 	if (error) {
1017 		counter_u64_add(ktls_switch_failed, 1);
1018 		ktls_free(tls_new);
1019 		ktls_free(tls);
1020 		INP_WLOCK(inp);
1021 		return (error);
1022 	}
1023 
1024 	error = sblock(&so->so_snd, SBL_WAIT);
1025 	if (error) {
1026 		counter_u64_add(ktls_switch_failed, 1);
1027 		ktls_free(tls_new);
1028 		ktls_free(tls);
1029 		INP_WLOCK(inp);
1030 		return (error);
1031 	}
1032 
1033 	/*
1034 	 * If we raced with another session change, keep the existing
1035 	 * session.
1036 	 */
1037 	if (tls != so->so_snd.sb_tls_info) {
1038 		counter_u64_add(ktls_switch_failed, 1);
1039 		sbunlock(&so->so_snd);
1040 		ktls_free(tls_new);
1041 		ktls_free(tls);
1042 		INP_WLOCK(inp);
1043 		return (EBUSY);
1044 	}
1045 
1046 	SOCKBUF_LOCK(&so->so_snd);
1047 	so->so_snd.sb_tls_info = tls_new;
1048 	if (tls_new->mode != TCP_TLS_MODE_SW)
1049 		so->so_snd.sb_flags |= SB_TLS_IFNET;
1050 	SOCKBUF_UNLOCK(&so->so_snd);
1051 	sbunlock(&so->so_snd);
1052 
1053 	/*
1054 	 * Drop two references on 'tls'.  The first is for the
1055 	 * ktls_hold() above.  The second drops the reference from the
1056 	 * socket buffer.
1057 	 */
1058 	KASSERT(tls->refcount >= 2, ("too few references on old session"));
1059 	ktls_free(tls);
1060 	ktls_free(tls);
1061 
1062 	if (mode == TCP_TLS_MODE_IFNET)
1063 		counter_u64_add(ktls_switch_to_ifnet, 1);
1064 	else
1065 		counter_u64_add(ktls_switch_to_sw, 1);
1066 
1067 	INP_WLOCK(inp);
1068 	return (0);
1069 }
1070 
1071 /*
1072  * Try to allocate a new TLS send tag.  This task is scheduled when
1073  * ip_output detects a route change while trying to transmit a packet
1074  * holding a TLS record.  If a new tag is allocated, replace the tag
1075  * in the TLS session.  Subsequent packets on the connection will use
1076  * the new tag.  If a new tag cannot be allocated, drop the
1077  * connection.
1078  */
1079 static void
1080 ktls_reset_send_tag(void *context, int pending)
1081 {
1082 	struct epoch_tracker et;
1083 	struct ktls_session *tls;
1084 	struct m_snd_tag *old, *new;
1085 	struct inpcb *inp;
1086 	struct tcpcb *tp;
1087 	int error;
1088 
1089 	MPASS(pending == 1);
1090 
1091 	tls = context;
1092 	inp = tls->inp;
1093 
1094 	/*
1095 	 * Free the old tag first before allocating a new one.
1096 	 * ip[6]_output_send() will treat a NULL send tag the same as
1097 	 * an ifp mismatch and drop packets until a new tag is
1098 	 * allocated.
1099 	 *
1100 	 * Write-lock the INP when changing tls->snd_tag since
1101 	 * ip[6]_output_send() holds a read-lock when reading the
1102 	 * pointer.
1103 	 */
1104 	INP_WLOCK(inp);
1105 	old = tls->snd_tag;
1106 	tls->snd_tag = NULL;
1107 	INP_WUNLOCK(inp);
1108 	if (old != NULL)
1109 		m_snd_tag_rele(old);
1110 
1111 	error = ktls_alloc_snd_tag(inp, tls, true, &new);
1112 
1113 	if (error == 0) {
1114 		INP_WLOCK(inp);
1115 		tls->snd_tag = new;
1116 		mtx_pool_lock(mtxpool_sleep, tls);
1117 		tls->reset_pending = false;
1118 		mtx_pool_unlock(mtxpool_sleep, tls);
1119 		if (!in_pcbrele_wlocked(inp))
1120 			INP_WUNLOCK(inp);
1121 
1122 		counter_u64_add(ktls_ifnet_reset, 1);
1123 
1124 		/*
1125 		 * XXX: Should we kick tcp_output explicitly now that
1126 		 * the send tag is fixed or just rely on timers?
1127 		 */
1128 	} else {
1129 		INP_INFO_RLOCK_ET(&V_tcbinfo, et);
1130 		INP_WLOCK(inp);
1131 		if (!in_pcbrele_wlocked(inp)) {
1132 			if (!(inp->inp_flags & INP_TIMEWAIT) &&
1133 			    !(inp->inp_flags & INP_DROPPED)) {
1134 				tp = intotcpcb(inp);
1135 				tp = tcp_drop(tp, ECONNABORTED);
1136 				if (tp != NULL)
1137 					INP_WUNLOCK(inp);
1138 				counter_u64_add(ktls_ifnet_reset_dropped, 1);
1139 			} else
1140 				INP_WUNLOCK(inp);
1141 		}
1142 		INP_INFO_RUNLOCK_ET(&V_tcbinfo, et);
1143 
1144 		counter_u64_add(ktls_ifnet_reset_failed, 1);
1145 
1146 		/*
1147 		 * Leave reset_pending true to avoid future tasks while
1148 		 * the socket goes away.
1149 		 */
1150 	}
1151 
1152 	ktls_free(tls);
1153 }
1154 
1155 int
1156 ktls_output_eagain(struct inpcb *inp, struct ktls_session *tls)
1157 {
1158 
1159 	if (inp == NULL)
1160 		return (ENOBUFS);
1161 
1162 	INP_LOCK_ASSERT(inp);
1163 
1164 	/*
1165 	 * See if we should schedule a task to update the send tag for
1166 	 * this session.
1167 	 */
1168 	mtx_pool_lock(mtxpool_sleep, tls);
1169 	if (!tls->reset_pending) {
1170 		(void) ktls_hold(tls);
1171 		in_pcbref(inp);
1172 		tls->inp = inp;
1173 		tls->reset_pending = true;
1174 		taskqueue_enqueue(taskqueue_thread, &tls->reset_tag_task);
1175 	}
1176 	mtx_pool_unlock(mtxpool_sleep, tls);
1177 	return (ENOBUFS);
1178 }
1179 #endif
1180 
1181 void
1182 ktls_destroy(struct ktls_session *tls)
1183 {
1184 	struct rm_priotracker prio;
1185 
1186 	ktls_cleanup(tls);
1187 	if (tls->be != NULL && ktls_allow_unload) {
1188 		rm_rlock(&ktls_backends_lock, &prio);
1189 		tls->be->use_count--;
1190 		rm_runlock(&ktls_backends_lock, &prio);
1191 	}
1192 	uma_zfree(ktls_session_zone, tls);
1193 }
1194 
1195 void
1196 ktls_seq(struct sockbuf *sb, struct mbuf *m)
1197 {
1198 	struct mbuf_ext_pgs *pgs;
1199 	struct tls_record_layer *tlshdr;
1200 	uint64_t seqno;
1201 
1202 	for (; m != NULL; m = m->m_next) {
1203 		KASSERT((m->m_flags & M_NOMAP) != 0,
1204 		    ("ktls_seq: mapped mbuf %p", m));
1205 
1206 		pgs = m->m_ext.ext_pgs;
1207 		pgs->seqno = sb->sb_tls_seqno;
1208 
1209 		/*
1210 		 * Store the sequence number in the TLS header as the
1211 		 * explicit part of the IV for GCM.
1212 		 */
1213 		if (pgs->tls->params.cipher_algorithm ==
1214 		    CRYPTO_AES_NIST_GCM_16) {
1215 			tlshdr = (void *)pgs->hdr;
1216 			seqno = htobe64(pgs->seqno);
1217 			memcpy(tlshdr + 1, &seqno, sizeof(seqno));
1218 		}
1219 		sb->sb_tls_seqno++;
1220 	}
1221 }
1222 
1223 /*
1224  * Add TLS framing (headers and trailers) to a chain of mbufs.  Each
1225  * mbuf in the chain must be an unmapped mbuf.  The payload of the
1226  * mbuf must be populated with the payload of each TLS record.
1227  *
1228  * The record_type argument specifies the TLS record type used when
1229  * populating the TLS header.
1230  *
1231  * The enq_count argument on return is set to the number of pages of
1232  * payload data for this entire chain that need to be encrypted via SW
1233  * encryption.  The returned value should be passed to ktls_enqueue
1234  * when scheduling encryption of this chain of mbufs.
1235  */
1236 int
1237 ktls_frame(struct mbuf *top, struct ktls_session *tls, int *enq_cnt,
1238     uint8_t record_type)
1239 {
1240 	struct tls_record_layer *tlshdr;
1241 	struct mbuf *m;
1242 	struct mbuf_ext_pgs *pgs;
1243 	uint16_t tls_len;
1244 	int maxlen;
1245 
1246 	maxlen = tls->params.max_frame_len;
1247 	*enq_cnt = 0;
1248 	for (m = top; m != NULL; m = m->m_next) {
1249 		/*
1250 		 * All mbufs in the chain should be non-empty TLS
1251 		 * records whose payload does not exceed the maximum
1252 		 * frame length.
1253 		 */
1254 		if (m->m_len > maxlen || m->m_len == 0)
1255 			return (EINVAL);
1256 		tls_len = m->m_len;
1257 
1258 		/*
1259 		 * TLS frames require unmapped mbufs to store session
1260 		 * info.
1261 		 */
1262 		KASSERT((m->m_flags & M_NOMAP) != 0,
1263 		    ("ktls_frame: mapped mbuf %p (top = %p)\n", m, top));
1264 
1265 		pgs = m->m_ext.ext_pgs;
1266 
1267 		/* Save a reference to the session. */
1268 		pgs->tls = ktls_hold(tls);
1269 
1270 		pgs->hdr_len = tls->params.tls_hlen;
1271 		pgs->trail_len = tls->params.tls_tlen;
1272 		if (tls->params.cipher_algorithm == CRYPTO_AES_CBC) {
1273 			int bs, delta;
1274 
1275 			/*
1276 			 * AES-CBC pads messages to a multiple of the
1277 			 * block size.  Note that the padding is
1278 			 * applied after the digest and the encryption
1279 			 * is done on the "plaintext || mac || padding".
1280 			 * At least one byte of padding is always
1281 			 * present.
1282 			 *
1283 			 * Compute the final trailer length assuming
1284 			 * at most one block of padding.
1285 			 * tls->params.sb_tls_tlen is the maximum
1286 			 * possible trailer length (padding + digest).
1287 			 * delta holds the number of excess padding
1288 			 * bytes if the maximum were used.  Those
1289 			 * extra bytes are removed.
1290 			 */
1291 			bs = tls->params.tls_bs;
1292 			delta = (tls_len + tls->params.tls_tlen) & (bs - 1);
1293 			pgs->trail_len -= delta;
1294 		}
1295 		m->m_len += pgs->hdr_len + pgs->trail_len;
1296 
1297 		/* Populate the TLS header. */
1298 		tlshdr = (void *)pgs->hdr;
1299 		tlshdr->tls_vmajor = tls->params.tls_vmajor;
1300 
1301 		/*
1302 		 * TLS 1.3 masquarades as TLS 1.2 with a record type
1303 		 * of TLS_RLTYPE_APP.
1304 		 */
1305 		if (tls->params.tls_vminor == TLS_MINOR_VER_THREE &&
1306 		    tls->params.tls_vmajor == TLS_MAJOR_VER_ONE) {
1307 			tlshdr->tls_vminor = TLS_MINOR_VER_TWO;
1308 			tlshdr->tls_type = TLS_RLTYPE_APP;
1309 			/* save the real record type for later */
1310 			pgs->record_type = record_type;
1311 		} else {
1312 			tlshdr->tls_vminor = tls->params.tls_vminor;
1313 			tlshdr->tls_type = record_type;
1314 		}
1315 		tlshdr->tls_length = htons(m->m_len - sizeof(*tlshdr));
1316 
1317 		/*
1318 		 * For GCM, the sequence number is stored in the
1319 		 * header by ktls_seq().  For CBC, a random nonce is
1320 		 * inserted for TLS 1.1+.
1321 		 */
1322 		if (tls->params.cipher_algorithm == CRYPTO_AES_CBC &&
1323 		    tls->params.tls_vminor >= TLS_MINOR_VER_ONE)
1324 			arc4rand(tlshdr + 1, AES_BLOCK_LEN, 0);
1325 
1326 		/*
1327 		 * When using SW encryption, mark the mbuf not ready.
1328 		 * It will be marked ready via sbready() after the
1329 		 * record has been encrypted.
1330 		 *
1331 		 * When using ifnet TLS, unencrypted TLS records are
1332 		 * sent down the stack to the NIC.
1333 		 */
1334 		if (tls->mode == TCP_TLS_MODE_SW) {
1335 			m->m_flags |= M_NOTREADY;
1336 			pgs->nrdy = pgs->npgs;
1337 			*enq_cnt += pgs->npgs;
1338 		}
1339 	}
1340 	return (0);
1341 }
1342 
1343 void
1344 ktls_enqueue_to_free(struct mbuf_ext_pgs *pgs)
1345 {
1346 	struct ktls_wq *wq;
1347 	bool running;
1348 
1349 	/* Mark it for freeing. */
1350 	pgs->mbuf = NULL;
1351 	wq = &ktls_wq[pgs->tls->wq_index];
1352 	mtx_lock(&wq->mtx);
1353 	STAILQ_INSERT_TAIL(&wq->head, pgs, stailq);
1354 	running = wq->running;
1355 	mtx_unlock(&wq->mtx);
1356 	if (!running)
1357 		wakeup(wq);
1358 }
1359 
1360 void
1361 ktls_enqueue(struct mbuf *m, struct socket *so, int page_count)
1362 {
1363 	struct mbuf_ext_pgs *pgs;
1364 	struct ktls_wq *wq;
1365 	bool running;
1366 
1367 	KASSERT(((m->m_flags & (M_NOMAP | M_NOTREADY)) ==
1368 	    (M_NOMAP | M_NOTREADY)),
1369 	    ("ktls_enqueue: %p not unready & nomap mbuf\n", m));
1370 	KASSERT(page_count != 0, ("enqueueing TLS mbuf with zero page count"));
1371 
1372 	pgs = m->m_ext.ext_pgs;
1373 
1374 	KASSERT(pgs->tls->mode == TCP_TLS_MODE_SW, ("!SW TLS mbuf"));
1375 
1376 	pgs->enc_cnt = page_count;
1377 	pgs->mbuf = m;
1378 
1379 	/*
1380 	 * Save a pointer to the socket.  The caller is responsible
1381 	 * for taking an additional reference via soref().
1382 	 */
1383 	pgs->so = so;
1384 
1385 	wq = &ktls_wq[pgs->tls->wq_index];
1386 	mtx_lock(&wq->mtx);
1387 	STAILQ_INSERT_TAIL(&wq->head, pgs, stailq);
1388 	running = wq->running;
1389 	mtx_unlock(&wq->mtx);
1390 	if (!running)
1391 		wakeup(wq);
1392 	counter_u64_add(ktls_cnt_on, 1);
1393 }
1394 
1395 static __noinline void
1396 ktls_encrypt(struct mbuf_ext_pgs *pgs)
1397 {
1398 	struct ktls_session *tls;
1399 	struct socket *so;
1400 	struct mbuf *m, *top;
1401 	vm_paddr_t parray[1 + btoc(TLS_MAX_MSG_SIZE_V10_2)];
1402 	struct iovec src_iov[1 + btoc(TLS_MAX_MSG_SIZE_V10_2)];
1403 	struct iovec dst_iov[1 + btoc(TLS_MAX_MSG_SIZE_V10_2)];
1404 	vm_page_t pg;
1405 	int error, i, len, npages, off, total_pages;
1406 	bool is_anon;
1407 
1408 	so = pgs->so;
1409 	tls = pgs->tls;
1410 	top = pgs->mbuf;
1411 	KASSERT(tls != NULL, ("tls = NULL, top = %p, pgs = %p\n", top, pgs));
1412 	KASSERT(so != NULL, ("so = NULL, top = %p, pgs = %p\n", top, pgs));
1413 #ifdef INVARIANTS
1414 	pgs->so = NULL;
1415 	pgs->mbuf = NULL;
1416 #endif
1417 	total_pages = pgs->enc_cnt;
1418 	npages = 0;
1419 
1420 	/*
1421 	 * Encrypt the TLS records in the chain of mbufs starting with
1422 	 * 'top'.  'total_pages' gives us a total count of pages and is
1423 	 * used to know when we have finished encrypting the TLS
1424 	 * records originally queued with 'top'.
1425 	 *
1426 	 * NB: These mbufs are queued in the socket buffer and
1427 	 * 'm_next' is traversing the mbufs in the socket buffer.  The
1428 	 * socket buffer lock is not held while traversing this chain.
1429 	 * Since the mbufs are all marked M_NOTREADY their 'm_next'
1430 	 * pointers should be stable.  However, the 'm_next' of the
1431 	 * last mbuf encrypted is not necessarily NULL.  It can point
1432 	 * to other mbufs appended while 'top' was on the TLS work
1433 	 * queue.
1434 	 *
1435 	 * Each mbuf holds an entire TLS record.
1436 	 */
1437 	error = 0;
1438 	for (m = top; npages != total_pages; m = m->m_next) {
1439 		pgs = m->m_ext.ext_pgs;
1440 
1441 		KASSERT(pgs->tls == tls,
1442 		    ("different TLS sessions in a single mbuf chain: %p vs %p",
1443 		    tls, pgs->tls));
1444 		KASSERT((m->m_flags & (M_NOMAP | M_NOTREADY)) ==
1445 		    (M_NOMAP | M_NOTREADY),
1446 		    ("%p not unready & nomap mbuf (top = %p)\n", m, top));
1447 		KASSERT(npages + pgs->npgs <= total_pages,
1448 		    ("page count mismatch: top %p, total_pages %d, m %p", top,
1449 		    total_pages, m));
1450 
1451 		/*
1452 		 * Generate source and destination ivoecs to pass to
1453 		 * the SW encryption backend.  For writable mbufs, the
1454 		 * destination iovec is a copy of the source and
1455 		 * encryption is done in place.  For file-backed mbufs
1456 		 * (from sendfile), anonymous wired pages are
1457 		 * allocated and assigned to the destination iovec.
1458 		 */
1459 		is_anon = (pgs->flags & MBUF_PEXT_FLAG_ANON) != 0;
1460 
1461 		off = pgs->first_pg_off;
1462 		for (i = 0; i < pgs->npgs; i++, off = 0) {
1463 			len = mbuf_ext_pg_len(pgs, i, off);
1464 			src_iov[i].iov_len = len;
1465 			src_iov[i].iov_base =
1466 			    (char *)(void *)PHYS_TO_DMAP(pgs->pa[i]) + off;
1467 
1468 			if (is_anon) {
1469 				dst_iov[i].iov_base = src_iov[i].iov_base;
1470 				dst_iov[i].iov_len = src_iov[i].iov_len;
1471 				continue;
1472 			}
1473 retry_page:
1474 			pg = vm_page_alloc(NULL, 0, VM_ALLOC_NORMAL |
1475 			    VM_ALLOC_NOOBJ | VM_ALLOC_NODUMP | VM_ALLOC_WIRED);
1476 			if (pg == NULL) {
1477 				vm_wait(NULL);
1478 				goto retry_page;
1479 			}
1480 			parray[i] = VM_PAGE_TO_PHYS(pg);
1481 			dst_iov[i].iov_base =
1482 			    (char *)(void *)PHYS_TO_DMAP(parray[i]) + off;
1483 			dst_iov[i].iov_len = len;
1484 		}
1485 
1486 		npages += i;
1487 
1488 		error = (*tls->sw_encrypt)(tls,
1489 		    (const struct tls_record_layer *)pgs->hdr,
1490 		    pgs->trail, src_iov, dst_iov, i, pgs->seqno,
1491 		    pgs->record_type);
1492 		if (error) {
1493 			counter_u64_add(ktls_offload_failed_crypto, 1);
1494 			break;
1495 		}
1496 
1497 		/*
1498 		 * For file-backed mbufs, release the file-backed
1499 		 * pages and replace them in the ext_pgs array with
1500 		 * the anonymous wired pages allocated above.
1501 		 */
1502 		if (!is_anon) {
1503 			/* Free the old pages. */
1504 			m->m_ext.ext_free(m);
1505 
1506 			/* Replace them with the new pages. */
1507 			for (i = 0; i < pgs->npgs; i++)
1508 				pgs->pa[i] = parray[i];
1509 
1510 			/* Use the basic free routine. */
1511 			m->m_ext.ext_free = mb_free_mext_pgs;
1512 
1513 			/* Pages are now writable. */
1514 			pgs->flags |= MBUF_PEXT_FLAG_ANON;
1515 		}
1516 
1517 		/*
1518 		 * Drop a reference to the session now that it is no
1519 		 * longer needed.  Existing code depends on encrypted
1520 		 * records having no associated session vs
1521 		 * yet-to-be-encrypted records having an associated
1522 		 * session.
1523 		 */
1524 		pgs->tls = NULL;
1525 		ktls_free(tls);
1526 	}
1527 
1528 	CURVNET_SET(so->so_vnet);
1529 	if (error == 0) {
1530 		(void)(*so->so_proto->pr_usrreqs->pru_ready)(so, top, npages);
1531 	} else {
1532 		so->so_proto->pr_usrreqs->pru_abort(so);
1533 		so->so_error = EIO;
1534 		mb_free_notready(top, total_pages);
1535 	}
1536 
1537 	SOCK_LOCK(so);
1538 	sorele(so);
1539 	CURVNET_RESTORE();
1540 }
1541 
1542 static void
1543 ktls_work_thread(void *ctx)
1544 {
1545 	struct ktls_wq *wq = ctx;
1546 	struct mbuf_ext_pgs *p, *n;
1547 	struct ktls_session *tls;
1548 	STAILQ_HEAD(, mbuf_ext_pgs) local_head;
1549 
1550 #if defined(__aarch64__) || defined(__amd64__) || defined(__i386__)
1551 	fpu_kern_thread(0);
1552 #endif
1553 	for (;;) {
1554 		mtx_lock(&wq->mtx);
1555 		while (STAILQ_EMPTY(&wq->head)) {
1556 			wq->running = false;
1557 			mtx_sleep(wq, &wq->mtx, 0, "-", 0);
1558 			wq->running = true;
1559 		}
1560 
1561 		STAILQ_INIT(&local_head);
1562 		STAILQ_CONCAT(&local_head, &wq->head);
1563 		mtx_unlock(&wq->mtx);
1564 
1565 		STAILQ_FOREACH_SAFE(p, &local_head, stailq, n) {
1566 			if (p->mbuf != NULL) {
1567 				ktls_encrypt(p);
1568 				counter_u64_add(ktls_cnt_on, -1);
1569 			} else {
1570 				tls = p->tls;
1571 				ktls_free(tls);
1572 				uma_zfree(zone_extpgs, p);
1573 			}
1574 		}
1575 	}
1576 }
1577