xref: /freebsd/sys/kern/uipc_ktls.c (revision 732a02b4e77866604a120a275c082bb6221bd2ff)
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 #include <net/if.h>
58 #include <net/if_var.h>
59 #ifdef RSS
60 #include <net/netisr.h>
61 #include <net/rss_config.h>
62 #endif
63 #if defined(INET) || defined(INET6)
64 #include <netinet/in.h>
65 #include <netinet/in_pcb.h>
66 #endif
67 #include <netinet/tcp_var.h>
68 #ifdef TCP_OFFLOAD
69 #include <netinet/tcp_offload.h>
70 #endif
71 #include <opencrypto/xform.h>
72 #include <vm/uma_dbg.h>
73 #include <vm/vm.h>
74 #include <vm/vm_pageout.h>
75 #include <vm/vm_page.h>
76 
77 struct ktls_wq {
78 	struct mtx	mtx;
79 	STAILQ_HEAD(, mbuf_ext_pgs) head;
80 	bool		running;
81 } __aligned(CACHE_LINE_SIZE);
82 
83 static struct ktls_wq *ktls_wq;
84 static struct proc *ktls_proc;
85 LIST_HEAD(, ktls_crypto_backend) ktls_backends;
86 static struct rmlock ktls_backends_lock;
87 static uma_zone_t ktls_session_zone;
88 static uint16_t ktls_cpuid_lookup[MAXCPU];
89 
90 SYSCTL_NODE(_kern_ipc, OID_AUTO, tls, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
91     "Kernel TLS offload");
92 SYSCTL_NODE(_kern_ipc_tls, OID_AUTO, stats, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
93     "Kernel TLS offload stats");
94 
95 static int ktls_allow_unload;
96 SYSCTL_INT(_kern_ipc_tls, OID_AUTO, allow_unload, CTLFLAG_RDTUN,
97     &ktls_allow_unload, 0, "Allow software crypto modules to unload");
98 
99 #ifdef RSS
100 static int ktls_bind_threads = 1;
101 #else
102 static int ktls_bind_threads;
103 #endif
104 SYSCTL_INT(_kern_ipc_tls, OID_AUTO, bind_threads, CTLFLAG_RDTUN,
105     &ktls_bind_threads, 0,
106     "Bind crypto threads to cores or domains at boot");
107 
108 static u_int ktls_maxlen = 16384;
109 SYSCTL_UINT(_kern_ipc_tls, OID_AUTO, maxlen, CTLFLAG_RWTUN,
110     &ktls_maxlen, 0, "Maximum TLS record size");
111 
112 static int ktls_number_threads;
113 SYSCTL_INT(_kern_ipc_tls_stats, OID_AUTO, threads, CTLFLAG_RD,
114     &ktls_number_threads, 0,
115     "Number of TLS threads in thread-pool");
116 
117 static bool ktls_offload_enable;
118 SYSCTL_BOOL(_kern_ipc_tls, OID_AUTO, enable, CTLFLAG_RW,
119     &ktls_offload_enable, 0,
120     "Enable support for kernel TLS offload");
121 
122 static bool ktls_cbc_enable = true;
123 SYSCTL_BOOL(_kern_ipc_tls, OID_AUTO, cbc_enable, CTLFLAG_RW,
124     &ktls_cbc_enable, 1,
125     "Enable Support of AES-CBC crypto for kernel TLS");
126 
127 static counter_u64_t ktls_tasks_active;
128 SYSCTL_COUNTER_U64(_kern_ipc_tls, OID_AUTO, tasks_active, CTLFLAG_RD,
129     &ktls_tasks_active, "Number of active tasks");
130 
131 static counter_u64_t ktls_cnt_on;
132 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats, OID_AUTO, so_inqueue, CTLFLAG_RD,
133     &ktls_cnt_on, "Number of TLS records in queue to tasks for SW crypto");
134 
135 static counter_u64_t ktls_offload_total;
136 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats, OID_AUTO, offload_total,
137     CTLFLAG_RD, &ktls_offload_total,
138     "Total successful TLS setups (parameters set)");
139 
140 static counter_u64_t ktls_offload_enable_calls;
141 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats, OID_AUTO, enable_calls,
142     CTLFLAG_RD, &ktls_offload_enable_calls,
143     "Total number of TLS enable calls made");
144 
145 static counter_u64_t ktls_offload_active;
146 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats, OID_AUTO, active, CTLFLAG_RD,
147     &ktls_offload_active, "Total Active TLS sessions");
148 
149 static counter_u64_t ktls_offload_failed_crypto;
150 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats, OID_AUTO, failed_crypto, CTLFLAG_RD,
151     &ktls_offload_failed_crypto, "Total TLS crypto failures");
152 
153 static counter_u64_t ktls_switch_to_ifnet;
154 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats, OID_AUTO, switch_to_ifnet, CTLFLAG_RD,
155     &ktls_switch_to_ifnet, "TLS sessions switched from SW to ifnet");
156 
157 static counter_u64_t ktls_switch_to_sw;
158 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats, OID_AUTO, switch_to_sw, CTLFLAG_RD,
159     &ktls_switch_to_sw, "TLS sessions switched from ifnet to SW");
160 
161 static counter_u64_t ktls_switch_failed;
162 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats, OID_AUTO, switch_failed, CTLFLAG_RD,
163     &ktls_switch_failed, "TLS sessions unable to switch between SW and ifnet");
164 
165 SYSCTL_NODE(_kern_ipc_tls, OID_AUTO, sw, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
166     "Software TLS session stats");
167 SYSCTL_NODE(_kern_ipc_tls, OID_AUTO, ifnet, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
168     "Hardware (ifnet) TLS session stats");
169 #ifdef TCP_OFFLOAD
170 SYSCTL_NODE(_kern_ipc_tls, OID_AUTO, toe, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
171     "TOE TLS session stats");
172 #endif
173 
174 static counter_u64_t ktls_sw_cbc;
175 SYSCTL_COUNTER_U64(_kern_ipc_tls_sw, OID_AUTO, cbc, CTLFLAG_RD, &ktls_sw_cbc,
176     "Active number of software TLS sessions using AES-CBC");
177 
178 static counter_u64_t ktls_sw_gcm;
179 SYSCTL_COUNTER_U64(_kern_ipc_tls_sw, OID_AUTO, gcm, CTLFLAG_RD, &ktls_sw_gcm,
180     "Active number of software TLS sessions using AES-GCM");
181 
182 static counter_u64_t ktls_ifnet_cbc;
183 SYSCTL_COUNTER_U64(_kern_ipc_tls_ifnet, OID_AUTO, cbc, CTLFLAG_RD,
184     &ktls_ifnet_cbc,
185     "Active number of ifnet TLS sessions using AES-CBC");
186 
187 static counter_u64_t ktls_ifnet_gcm;
188 SYSCTL_COUNTER_U64(_kern_ipc_tls_ifnet, OID_AUTO, gcm, CTLFLAG_RD,
189     &ktls_ifnet_gcm,
190     "Active number of ifnet TLS sessions using AES-GCM");
191 
192 static counter_u64_t ktls_ifnet_reset;
193 SYSCTL_COUNTER_U64(_kern_ipc_tls_ifnet, OID_AUTO, reset, CTLFLAG_RD,
194     &ktls_ifnet_reset, "TLS sessions updated to a new ifnet send tag");
195 
196 static counter_u64_t ktls_ifnet_reset_dropped;
197 SYSCTL_COUNTER_U64(_kern_ipc_tls_ifnet, OID_AUTO, reset_dropped, CTLFLAG_RD,
198     &ktls_ifnet_reset_dropped,
199     "TLS sessions dropped after failing to update ifnet send tag");
200 
201 static counter_u64_t ktls_ifnet_reset_failed;
202 SYSCTL_COUNTER_U64(_kern_ipc_tls_ifnet, OID_AUTO, reset_failed, CTLFLAG_RD,
203     &ktls_ifnet_reset_failed,
204     "TLS sessions that failed to allocate a new ifnet send tag");
205 
206 static int ktls_ifnet_permitted;
207 SYSCTL_UINT(_kern_ipc_tls_ifnet, OID_AUTO, permitted, CTLFLAG_RWTUN,
208     &ktls_ifnet_permitted, 1,
209     "Whether to permit hardware (ifnet) TLS sessions");
210 
211 #ifdef TCP_OFFLOAD
212 static counter_u64_t ktls_toe_cbc;
213 SYSCTL_COUNTER_U64(_kern_ipc_tls_toe, OID_AUTO, cbc, CTLFLAG_RD,
214     &ktls_toe_cbc,
215     "Active number of TOE TLS sessions using AES-CBC");
216 
217 static counter_u64_t ktls_toe_gcm;
218 SYSCTL_COUNTER_U64(_kern_ipc_tls_toe, OID_AUTO, gcm, CTLFLAG_RD,
219     &ktls_toe_gcm,
220     "Active number of TOE TLS sessions using AES-GCM");
221 #endif
222 
223 static MALLOC_DEFINE(M_KTLS, "ktls", "Kernel TLS");
224 
225 static void ktls_cleanup(struct ktls_session *tls);
226 #if defined(INET) || defined(INET6)
227 static void ktls_reset_send_tag(void *context, int pending);
228 #endif
229 static void ktls_work_thread(void *ctx);
230 
231 int
232 ktls_crypto_backend_register(struct ktls_crypto_backend *be)
233 {
234 	struct ktls_crypto_backend *curr_be, *tmp;
235 
236 	if (be->api_version != KTLS_API_VERSION) {
237 		printf("KTLS: API version mismatch (%d vs %d) for %s\n",
238 		    be->api_version, KTLS_API_VERSION,
239 		    be->name);
240 		return (EINVAL);
241 	}
242 
243 	rm_wlock(&ktls_backends_lock);
244 	printf("KTLS: Registering crypto method %s with prio %d\n",
245 	       be->name, be->prio);
246 	if (LIST_EMPTY(&ktls_backends)) {
247 		LIST_INSERT_HEAD(&ktls_backends, be, next);
248 	} else {
249 		LIST_FOREACH_SAFE(curr_be, &ktls_backends, next, tmp) {
250 			if (curr_be->prio < be->prio) {
251 				LIST_INSERT_BEFORE(curr_be, be, next);
252 				break;
253 			}
254 			if (LIST_NEXT(curr_be, next) == NULL) {
255 				LIST_INSERT_AFTER(curr_be, be, next);
256 				break;
257 			}
258 		}
259 	}
260 	rm_wunlock(&ktls_backends_lock);
261 	return (0);
262 }
263 
264 int
265 ktls_crypto_backend_deregister(struct ktls_crypto_backend *be)
266 {
267 	struct ktls_crypto_backend *tmp;
268 
269 	/*
270 	 * Don't error if the backend isn't registered.  This permits
271 	 * MOD_UNLOAD handlers to use this function unconditionally.
272 	 */
273 	rm_wlock(&ktls_backends_lock);
274 	LIST_FOREACH(tmp, &ktls_backends, next) {
275 		if (tmp == be)
276 			break;
277 	}
278 	if (tmp == NULL) {
279 		rm_wunlock(&ktls_backends_lock);
280 		return (0);
281 	}
282 
283 	if (!ktls_allow_unload) {
284 		rm_wunlock(&ktls_backends_lock);
285 		printf(
286 		    "KTLS: Deregistering crypto method %s is not supported\n",
287 		    be->name);
288 		return (EBUSY);
289 	}
290 
291 	if (be->use_count) {
292 		rm_wunlock(&ktls_backends_lock);
293 		return (EBUSY);
294 	}
295 
296 	LIST_REMOVE(be, next);
297 	rm_wunlock(&ktls_backends_lock);
298 	return (0);
299 }
300 
301 #if defined(INET) || defined(INET6)
302 static u_int
303 ktls_get_cpu(struct socket *so)
304 {
305 	struct inpcb *inp;
306 	u_int cpuid;
307 
308 	inp = sotoinpcb(so);
309 #ifdef RSS
310 	cpuid = rss_hash2cpuid(inp->inp_flowid, inp->inp_flowtype);
311 	if (cpuid != NETISR_CPUID_NONE)
312 		return (cpuid);
313 #endif
314 	/*
315 	 * Just use the flowid to shard connections in a repeatable
316 	 * fashion.  Note that some crypto backends rely on the
317 	 * serialization provided by having the same connection use
318 	 * the same queue.
319 	 */
320 	cpuid = ktls_cpuid_lookup[inp->inp_flowid % ktls_number_threads];
321 	return (cpuid);
322 }
323 #endif
324 
325 static void
326 ktls_init(void *dummy __unused)
327 {
328 	struct thread *td;
329 	struct pcpu *pc;
330 	cpuset_t mask;
331 	int error, i;
332 
333 	ktls_tasks_active = counter_u64_alloc(M_WAITOK);
334 	ktls_cnt_on = counter_u64_alloc(M_WAITOK);
335 	ktls_offload_total = counter_u64_alloc(M_WAITOK);
336 	ktls_offload_enable_calls = counter_u64_alloc(M_WAITOK);
337 	ktls_offload_active = counter_u64_alloc(M_WAITOK);
338 	ktls_offload_failed_crypto = counter_u64_alloc(M_WAITOK);
339 	ktls_switch_to_ifnet = counter_u64_alloc(M_WAITOK);
340 	ktls_switch_to_sw = counter_u64_alloc(M_WAITOK);
341 	ktls_switch_failed = counter_u64_alloc(M_WAITOK);
342 	ktls_sw_cbc = counter_u64_alloc(M_WAITOK);
343 	ktls_sw_gcm = counter_u64_alloc(M_WAITOK);
344 	ktls_ifnet_cbc = counter_u64_alloc(M_WAITOK);
345 	ktls_ifnet_gcm = counter_u64_alloc(M_WAITOK);
346 	ktls_ifnet_reset = counter_u64_alloc(M_WAITOK);
347 	ktls_ifnet_reset_dropped = counter_u64_alloc(M_WAITOK);
348 	ktls_ifnet_reset_failed = counter_u64_alloc(M_WAITOK);
349 #ifdef TCP_OFFLOAD
350 	ktls_toe_cbc = counter_u64_alloc(M_WAITOK);
351 	ktls_toe_gcm = counter_u64_alloc(M_WAITOK);
352 #endif
353 
354 	rm_init(&ktls_backends_lock, "ktls backends");
355 	LIST_INIT(&ktls_backends);
356 
357 	ktls_wq = malloc(sizeof(*ktls_wq) * (mp_maxid + 1), M_KTLS,
358 	    M_WAITOK | M_ZERO);
359 
360 	ktls_session_zone = uma_zcreate("ktls_session",
361 	    sizeof(struct ktls_session),
362 	    NULL, NULL, NULL, NULL,
363 	    UMA_ALIGN_CACHE, 0);
364 
365 	/*
366 	 * Initialize the workqueues to run the TLS work.  We create a
367 	 * work queue for each CPU.
368 	 */
369 	CPU_FOREACH(i) {
370 		STAILQ_INIT(&ktls_wq[i].head);
371 		mtx_init(&ktls_wq[i].mtx, "ktls work queue", NULL, MTX_DEF);
372 		error = kproc_kthread_add(ktls_work_thread, &ktls_wq[i],
373 		    &ktls_proc, &td, 0, 0, "KTLS", "thr_%d", i);
374 		if (error)
375 			panic("Can't add KTLS thread %d error %d", i, error);
376 
377 		/*
378 		 * Bind threads to cores.  If ktls_bind_threads is >
379 		 * 1, then we bind to the NUMA domain.
380 		 */
381 		if (ktls_bind_threads) {
382 			if (ktls_bind_threads > 1) {
383 				pc = pcpu_find(i);
384 				CPU_COPY(&cpuset_domain[pc->pc_domain], &mask);
385 			} else {
386 				CPU_SETOF(i, &mask);
387 			}
388 			error = cpuset_setthread(td->td_tid, &mask);
389 			if (error)
390 				panic(
391 			    "Unable to bind KTLS thread for CPU %d error %d",
392 				     i, error);
393 		}
394 		ktls_cpuid_lookup[ktls_number_threads] = i;
395 		ktls_number_threads++;
396 	}
397 	printf("KTLS: Initialized %d threads\n", ktls_number_threads);
398 }
399 SYSINIT(ktls, SI_SUB_SMP + 1, SI_ORDER_ANY, ktls_init, NULL);
400 
401 #if defined(INET) || defined(INET6)
402 static int
403 ktls_create_session(struct socket *so, struct tls_enable *en,
404     struct ktls_session **tlsp)
405 {
406 	struct ktls_session *tls;
407 	int error;
408 
409 	/* Only TLS 1.0 - 1.3 are supported. */
410 	if (en->tls_vmajor != TLS_MAJOR_VER_ONE)
411 		return (EINVAL);
412 	if (en->tls_vminor < TLS_MINOR_VER_ZERO ||
413 	    en->tls_vminor > TLS_MINOR_VER_THREE)
414 		return (EINVAL);
415 
416 	if (en->auth_key_len < 0 || en->auth_key_len > TLS_MAX_PARAM_SIZE)
417 		return (EINVAL);
418 	if (en->cipher_key_len < 0 || en->cipher_key_len > TLS_MAX_PARAM_SIZE)
419 		return (EINVAL);
420 	if (en->iv_len < 0 || en->iv_len > sizeof(tls->params.iv))
421 		return (EINVAL);
422 
423 	/* All supported algorithms require a cipher key. */
424 	if (en->cipher_key_len == 0)
425 		return (EINVAL);
426 
427 	/* No flags are currently supported. */
428 	if (en->flags != 0)
429 		return (EINVAL);
430 
431 	/* Common checks for supported algorithms. */
432 	switch (en->cipher_algorithm) {
433 	case CRYPTO_AES_NIST_GCM_16:
434 		/*
435 		 * auth_algorithm isn't used, but permit GMAC values
436 		 * for compatibility.
437 		 */
438 		switch (en->auth_algorithm) {
439 		case 0:
440 #ifdef COMPAT_FREEBSD12
441 		/* XXX: Really 13.0-current COMPAT. */
442 		case CRYPTO_AES_128_NIST_GMAC:
443 		case CRYPTO_AES_192_NIST_GMAC:
444 		case CRYPTO_AES_256_NIST_GMAC:
445 #endif
446 			break;
447 		default:
448 			return (EINVAL);
449 		}
450 		if (en->auth_key_len != 0)
451 			return (EINVAL);
452 		if ((en->tls_vminor == TLS_MINOR_VER_TWO &&
453 			en->iv_len != TLS_AEAD_GCM_LEN) ||
454 		    (en->tls_vminor == TLS_MINOR_VER_THREE &&
455 			en->iv_len != TLS_1_3_GCM_IV_LEN))
456 			return (EINVAL);
457 		break;
458 	case CRYPTO_AES_CBC:
459 		switch (en->auth_algorithm) {
460 		case CRYPTO_SHA1_HMAC:
461 			/*
462 			 * TLS 1.0 requires an implicit IV.  TLS 1.1+
463 			 * all use explicit IVs.
464 			 */
465 			if (en->tls_vminor == TLS_MINOR_VER_ZERO) {
466 				if (en->iv_len != TLS_CBC_IMPLICIT_IV_LEN)
467 					return (EINVAL);
468 				break;
469 			}
470 
471 			/* FALLTHROUGH */
472 		case CRYPTO_SHA2_256_HMAC:
473 		case CRYPTO_SHA2_384_HMAC:
474 			/* Ignore any supplied IV. */
475 			en->iv_len = 0;
476 			break;
477 		default:
478 			return (EINVAL);
479 		}
480 		if (en->auth_key_len == 0)
481 			return (EINVAL);
482 		break;
483 	default:
484 		return (EINVAL);
485 	}
486 
487 	tls = uma_zalloc(ktls_session_zone, M_WAITOK | M_ZERO);
488 
489 	counter_u64_add(ktls_offload_active, 1);
490 
491 	refcount_init(&tls->refcount, 1);
492 	TASK_INIT(&tls->reset_tag_task, 0, ktls_reset_send_tag, tls);
493 
494 	tls->wq_index = ktls_get_cpu(so);
495 
496 	tls->params.cipher_algorithm = en->cipher_algorithm;
497 	tls->params.auth_algorithm = en->auth_algorithm;
498 	tls->params.tls_vmajor = en->tls_vmajor;
499 	tls->params.tls_vminor = en->tls_vminor;
500 	tls->params.flags = en->flags;
501 	tls->params.max_frame_len = min(TLS_MAX_MSG_SIZE_V10_2, ktls_maxlen);
502 
503 	/* Set the header and trailer lengths. */
504 	tls->params.tls_hlen = sizeof(struct tls_record_layer);
505 	switch (en->cipher_algorithm) {
506 	case CRYPTO_AES_NIST_GCM_16:
507 		/*
508 		 * TLS 1.2 uses a 4 byte implicit IV with an explicit 8 byte
509 		 * nonce.  TLS 1.3 uses a 12 byte implicit IV.
510 		 */
511 		if (en->tls_vminor < TLS_MINOR_VER_THREE)
512 			tls->params.tls_hlen += sizeof(uint64_t);
513 		tls->params.tls_tlen = AES_GMAC_HASH_LEN;
514 
515 		/*
516 		 * TLS 1.3 includes optional padding which we
517 		 * do not support, and also puts the "real" record
518 		 * type at the end of the encrypted data.
519 		 */
520 		if (en->tls_vminor == TLS_MINOR_VER_THREE)
521 			tls->params.tls_tlen += sizeof(uint8_t);
522 
523 		tls->params.tls_bs = 1;
524 		break;
525 	case CRYPTO_AES_CBC:
526 		switch (en->auth_algorithm) {
527 		case CRYPTO_SHA1_HMAC:
528 			if (en->tls_vminor == TLS_MINOR_VER_ZERO) {
529 				/* Implicit IV, no nonce. */
530 			} else {
531 				tls->params.tls_hlen += AES_BLOCK_LEN;
532 			}
533 			tls->params.tls_tlen = AES_BLOCK_LEN +
534 			    SHA1_HASH_LEN;
535 			break;
536 		case CRYPTO_SHA2_256_HMAC:
537 			tls->params.tls_hlen += AES_BLOCK_LEN;
538 			tls->params.tls_tlen = AES_BLOCK_LEN +
539 			    SHA2_256_HASH_LEN;
540 			break;
541 		case CRYPTO_SHA2_384_HMAC:
542 			tls->params.tls_hlen += AES_BLOCK_LEN;
543 			tls->params.tls_tlen = AES_BLOCK_LEN +
544 			    SHA2_384_HASH_LEN;
545 			break;
546 		default:
547 			panic("invalid hmac");
548 		}
549 		tls->params.tls_bs = AES_BLOCK_LEN;
550 		break;
551 	default:
552 		panic("invalid cipher");
553 	}
554 
555 	KASSERT(tls->params.tls_hlen <= MBUF_PEXT_HDR_LEN,
556 	    ("TLS header length too long: %d", tls->params.tls_hlen));
557 	KASSERT(tls->params.tls_tlen <= MBUF_PEXT_TRAIL_LEN,
558 	    ("TLS trailer length too long: %d", tls->params.tls_tlen));
559 
560 	if (en->auth_key_len != 0) {
561 		tls->params.auth_key_len = en->auth_key_len;
562 		tls->params.auth_key = malloc(en->auth_key_len, M_KTLS,
563 		    M_WAITOK);
564 		error = copyin(en->auth_key, tls->params.auth_key,
565 		    en->auth_key_len);
566 		if (error)
567 			goto out;
568 	}
569 
570 	tls->params.cipher_key_len = en->cipher_key_len;
571 	tls->params.cipher_key = malloc(en->cipher_key_len, M_KTLS, M_WAITOK);
572 	error = copyin(en->cipher_key, tls->params.cipher_key,
573 	    en->cipher_key_len);
574 	if (error)
575 		goto out;
576 
577 	/*
578 	 * This holds the implicit portion of the nonce for GCM and
579 	 * the initial implicit IV for TLS 1.0.  The explicit portions
580 	 * of the IV are generated in ktls_frame().
581 	 */
582 	if (en->iv_len != 0) {
583 		tls->params.iv_len = en->iv_len;
584 		error = copyin(en->iv, tls->params.iv, en->iv_len);
585 		if (error)
586 			goto out;
587 
588 		/*
589 		 * For TLS 1.2, generate an 8-byte nonce as a counter
590 		 * to generate unique explicit IVs.
591 		 *
592 		 * Store this counter in the last 8 bytes of the IV
593 		 * array so that it is 8-byte aligned.
594 		 */
595 		if (en->cipher_algorithm == CRYPTO_AES_NIST_GCM_16 &&
596 		    en->tls_vminor == TLS_MINOR_VER_TWO)
597 			arc4rand(tls->params.iv + 8, sizeof(uint64_t), 0);
598 	}
599 
600 	*tlsp = tls;
601 	return (0);
602 
603 out:
604 	ktls_cleanup(tls);
605 	return (error);
606 }
607 
608 static struct ktls_session *
609 ktls_clone_session(struct ktls_session *tls)
610 {
611 	struct ktls_session *tls_new;
612 
613 	tls_new = uma_zalloc(ktls_session_zone, M_WAITOK | M_ZERO);
614 
615 	counter_u64_add(ktls_offload_active, 1);
616 
617 	refcount_init(&tls_new->refcount, 1);
618 
619 	/* Copy fields from existing session. */
620 	tls_new->params = tls->params;
621 	tls_new->wq_index = tls->wq_index;
622 
623 	/* Deep copy keys. */
624 	if (tls_new->params.auth_key != NULL) {
625 		tls_new->params.auth_key = malloc(tls->params.auth_key_len,
626 		    M_KTLS, M_WAITOK);
627 		memcpy(tls_new->params.auth_key, tls->params.auth_key,
628 		    tls->params.auth_key_len);
629 	}
630 
631 	tls_new->params.cipher_key = malloc(tls->params.cipher_key_len, M_KTLS,
632 	    M_WAITOK);
633 	memcpy(tls_new->params.cipher_key, tls->params.cipher_key,
634 	    tls->params.cipher_key_len);
635 
636 	return (tls_new);
637 }
638 #endif
639 
640 static void
641 ktls_cleanup(struct ktls_session *tls)
642 {
643 
644 	counter_u64_add(ktls_offload_active, -1);
645 	switch (tls->mode) {
646 	case TCP_TLS_MODE_SW:
647 		MPASS(tls->be != NULL);
648 		switch (tls->params.cipher_algorithm) {
649 		case CRYPTO_AES_CBC:
650 			counter_u64_add(ktls_sw_cbc, -1);
651 			break;
652 		case CRYPTO_AES_NIST_GCM_16:
653 			counter_u64_add(ktls_sw_gcm, -1);
654 			break;
655 		}
656 		tls->free(tls);
657 		break;
658 	case TCP_TLS_MODE_IFNET:
659 		switch (tls->params.cipher_algorithm) {
660 		case CRYPTO_AES_CBC:
661 			counter_u64_add(ktls_ifnet_cbc, -1);
662 			break;
663 		case CRYPTO_AES_NIST_GCM_16:
664 			counter_u64_add(ktls_ifnet_gcm, -1);
665 			break;
666 		}
667 		m_snd_tag_rele(tls->snd_tag);
668 		break;
669 #ifdef TCP_OFFLOAD
670 	case TCP_TLS_MODE_TOE:
671 		switch (tls->params.cipher_algorithm) {
672 		case CRYPTO_AES_CBC:
673 			counter_u64_add(ktls_toe_cbc, -1);
674 			break;
675 		case CRYPTO_AES_NIST_GCM_16:
676 			counter_u64_add(ktls_toe_gcm, -1);
677 			break;
678 		}
679 		break;
680 #endif
681 	}
682 	if (tls->params.auth_key != NULL) {
683 		explicit_bzero(tls->params.auth_key, tls->params.auth_key_len);
684 		free(tls->params.auth_key, M_KTLS);
685 		tls->params.auth_key = NULL;
686 		tls->params.auth_key_len = 0;
687 	}
688 	if (tls->params.cipher_key != NULL) {
689 		explicit_bzero(tls->params.cipher_key,
690 		    tls->params.cipher_key_len);
691 		free(tls->params.cipher_key, M_KTLS);
692 		tls->params.cipher_key = NULL;
693 		tls->params.cipher_key_len = 0;
694 	}
695 	explicit_bzero(tls->params.iv, sizeof(tls->params.iv));
696 }
697 
698 #if defined(INET) || defined(INET6)
699 
700 #ifdef TCP_OFFLOAD
701 static int
702 ktls_try_toe(struct socket *so, struct ktls_session *tls)
703 {
704 	struct inpcb *inp;
705 	struct tcpcb *tp;
706 	int error;
707 
708 	inp = so->so_pcb;
709 	INP_WLOCK(inp);
710 	if (inp->inp_flags2 & INP_FREED) {
711 		INP_WUNLOCK(inp);
712 		return (ECONNRESET);
713 	}
714 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
715 		INP_WUNLOCK(inp);
716 		return (ECONNRESET);
717 	}
718 	if (inp->inp_socket == NULL) {
719 		INP_WUNLOCK(inp);
720 		return (ECONNRESET);
721 	}
722 	tp = intotcpcb(inp);
723 	if (tp->tod == NULL) {
724 		INP_WUNLOCK(inp);
725 		return (EOPNOTSUPP);
726 	}
727 
728 	error = tcp_offload_alloc_tls_session(tp, tls);
729 	INP_WUNLOCK(inp);
730 	if (error == 0) {
731 		tls->mode = TCP_TLS_MODE_TOE;
732 		switch (tls->params.cipher_algorithm) {
733 		case CRYPTO_AES_CBC:
734 			counter_u64_add(ktls_toe_cbc, 1);
735 			break;
736 		case CRYPTO_AES_NIST_GCM_16:
737 			counter_u64_add(ktls_toe_gcm, 1);
738 			break;
739 		}
740 	}
741 	return (error);
742 }
743 #endif
744 
745 /*
746  * Common code used when first enabling ifnet TLS on a connection or
747  * when allocating a new ifnet TLS session due to a routing change.
748  * This function allocates a new TLS send tag on whatever interface
749  * the connection is currently routed over.
750  */
751 static int
752 ktls_alloc_snd_tag(struct inpcb *inp, struct ktls_session *tls, bool force,
753     struct m_snd_tag **mstp)
754 {
755 	union if_snd_tag_alloc_params params;
756 	struct ifnet *ifp;
757 	struct rtentry *rt;
758 	struct tcpcb *tp;
759 	int error;
760 
761 	INP_RLOCK(inp);
762 	if (inp->inp_flags2 & INP_FREED) {
763 		INP_RUNLOCK(inp);
764 		return (ECONNRESET);
765 	}
766 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
767 		INP_RUNLOCK(inp);
768 		return (ECONNRESET);
769 	}
770 	if (inp->inp_socket == NULL) {
771 		INP_RUNLOCK(inp);
772 		return (ECONNRESET);
773 	}
774 	tp = intotcpcb(inp);
775 
776 	/*
777 	 * Check administrative controls on ifnet TLS to determine if
778 	 * ifnet TLS should be denied.
779 	 *
780 	 * - Always permit 'force' requests.
781 	 * - ktls_ifnet_permitted == 0: always deny.
782 	 */
783 	if (!force && ktls_ifnet_permitted == 0) {
784 		INP_RUNLOCK(inp);
785 		return (ENXIO);
786 	}
787 
788 	/*
789 	 * XXX: Use the cached route in the inpcb to find the
790 	 * interface.  This should perhaps instead use
791 	 * rtalloc1_fib(dst, 0, 0, fibnum).  Since KTLS is only
792 	 * enabled after a connection has completed key negotiation in
793 	 * userland, the cached route will be present in practice.
794 	 */
795 	rt = inp->inp_route.ro_rt;
796 	if (rt == NULL || rt->rt_ifp == NULL) {
797 		INP_RUNLOCK(inp);
798 		return (ENXIO);
799 	}
800 	ifp = rt->rt_ifp;
801 	if_ref(ifp);
802 
803 	params.hdr.type = IF_SND_TAG_TYPE_TLS;
804 	params.hdr.flowid = inp->inp_flowid;
805 	params.hdr.flowtype = inp->inp_flowtype;
806 	params.hdr.numa_domain = inp->inp_numa_domain;
807 	params.tls.inp = inp;
808 	params.tls.tls = tls;
809 	INP_RUNLOCK(inp);
810 
811 	if (ifp->if_snd_tag_alloc == NULL) {
812 		error = EOPNOTSUPP;
813 		goto out;
814 	}
815 	if ((ifp->if_capenable & IFCAP_NOMAP) == 0) {
816 		error = EOPNOTSUPP;
817 		goto out;
818 	}
819 	if (inp->inp_vflag & INP_IPV6) {
820 		if ((ifp->if_capenable & IFCAP_TXTLS6) == 0) {
821 			error = EOPNOTSUPP;
822 			goto out;
823 		}
824 	} else {
825 		if ((ifp->if_capenable & IFCAP_TXTLS4) == 0) {
826 			error = EOPNOTSUPP;
827 			goto out;
828 		}
829 	}
830 	error = ifp->if_snd_tag_alloc(ifp, &params, mstp);
831 out:
832 	if_rele(ifp);
833 	return (error);
834 }
835 
836 static int
837 ktls_try_ifnet(struct socket *so, struct ktls_session *tls, bool force)
838 {
839 	struct m_snd_tag *mst;
840 	int error;
841 
842 	error = ktls_alloc_snd_tag(so->so_pcb, tls, force, &mst);
843 	if (error == 0) {
844 		tls->mode = TCP_TLS_MODE_IFNET;
845 		tls->snd_tag = mst;
846 		switch (tls->params.cipher_algorithm) {
847 		case CRYPTO_AES_CBC:
848 			counter_u64_add(ktls_ifnet_cbc, 1);
849 			break;
850 		case CRYPTO_AES_NIST_GCM_16:
851 			counter_u64_add(ktls_ifnet_gcm, 1);
852 			break;
853 		}
854 	}
855 	return (error);
856 }
857 
858 static int
859 ktls_try_sw(struct socket *so, struct ktls_session *tls)
860 {
861 	struct rm_priotracker prio;
862 	struct ktls_crypto_backend *be;
863 
864 	/*
865 	 * Choose the best software crypto backend.  Backends are
866 	 * stored in sorted priority order (larget value == most
867 	 * important at the head of the list), so this just stops on
868 	 * the first backend that claims the session by returning
869 	 * success.
870 	 */
871 	if (ktls_allow_unload)
872 		rm_rlock(&ktls_backends_lock, &prio);
873 	LIST_FOREACH(be, &ktls_backends, next) {
874 		if (be->try(so, tls) == 0)
875 			break;
876 		KASSERT(tls->cipher == NULL,
877 		    ("ktls backend leaked a cipher pointer"));
878 	}
879 	if (be != NULL) {
880 		if (ktls_allow_unload)
881 			be->use_count++;
882 		tls->be = be;
883 	}
884 	if (ktls_allow_unload)
885 		rm_runlock(&ktls_backends_lock, &prio);
886 	if (be == NULL)
887 		return (EOPNOTSUPP);
888 	tls->mode = TCP_TLS_MODE_SW;
889 	switch (tls->params.cipher_algorithm) {
890 	case CRYPTO_AES_CBC:
891 		counter_u64_add(ktls_sw_cbc, 1);
892 		break;
893 	case CRYPTO_AES_NIST_GCM_16:
894 		counter_u64_add(ktls_sw_gcm, 1);
895 		break;
896 	}
897 	return (0);
898 }
899 
900 int
901 ktls_enable_tx(struct socket *so, struct tls_enable *en)
902 {
903 	struct ktls_session *tls;
904 	int error;
905 
906 	if (!ktls_offload_enable)
907 		return (ENOTSUP);
908 
909 	counter_u64_add(ktls_offload_enable_calls, 1);
910 
911 	/*
912 	 * This should always be true since only the TCP socket option
913 	 * invokes this function.
914 	 */
915 	if (so->so_proto->pr_protocol != IPPROTO_TCP)
916 		return (EINVAL);
917 
918 	/*
919 	 * XXX: Don't overwrite existing sessions.  We should permit
920 	 * this to support rekeying in the future.
921 	 */
922 	if (so->so_snd.sb_tls_info != NULL)
923 		return (EALREADY);
924 
925 	if (en->cipher_algorithm == CRYPTO_AES_CBC && !ktls_cbc_enable)
926 		return (ENOTSUP);
927 
928 	/* TLS requires ext pgs */
929 	if (mb_use_ext_pgs == 0)
930 		return (ENXIO);
931 
932 	error = ktls_create_session(so, en, &tls);
933 	if (error)
934 		return (error);
935 
936 	/* Prefer TOE -> ifnet TLS -> software TLS. */
937 #ifdef TCP_OFFLOAD
938 	error = ktls_try_toe(so, tls);
939 	if (error)
940 #endif
941 		error = ktls_try_ifnet(so, tls, false);
942 	if (error)
943 		error = ktls_try_sw(so, tls);
944 
945 	if (error) {
946 		ktls_cleanup(tls);
947 		return (error);
948 	}
949 
950 	error = sblock(&so->so_snd, SBL_WAIT);
951 	if (error) {
952 		ktls_cleanup(tls);
953 		return (error);
954 	}
955 
956 	SOCKBUF_LOCK(&so->so_snd);
957 	so->so_snd.sb_tls_info = tls;
958 	if (tls->mode != TCP_TLS_MODE_SW)
959 		so->so_snd.sb_flags |= SB_TLS_IFNET;
960 	SOCKBUF_UNLOCK(&so->so_snd);
961 	sbunlock(&so->so_snd);
962 
963 	counter_u64_add(ktls_offload_total, 1);
964 
965 	return (0);
966 }
967 
968 int
969 ktls_get_tx_mode(struct socket *so)
970 {
971 	struct ktls_session *tls;
972 	struct inpcb *inp;
973 	int mode;
974 
975 	inp = so->so_pcb;
976 	INP_WLOCK_ASSERT(inp);
977 	SOCKBUF_LOCK(&so->so_snd);
978 	tls = so->so_snd.sb_tls_info;
979 	if (tls == NULL)
980 		mode = TCP_TLS_MODE_NONE;
981 	else
982 		mode = tls->mode;
983 	SOCKBUF_UNLOCK(&so->so_snd);
984 	return (mode);
985 }
986 
987 /*
988  * Switch between SW and ifnet TLS sessions as requested.
989  */
990 int
991 ktls_set_tx_mode(struct socket *so, int mode)
992 {
993 	struct ktls_session *tls, *tls_new;
994 	struct inpcb *inp;
995 	int error;
996 
997 	switch (mode) {
998 	case TCP_TLS_MODE_SW:
999 	case TCP_TLS_MODE_IFNET:
1000 		break;
1001 	default:
1002 		return (EINVAL);
1003 	}
1004 
1005 	inp = so->so_pcb;
1006 	INP_WLOCK_ASSERT(inp);
1007 	SOCKBUF_LOCK(&so->so_snd);
1008 	tls = so->so_snd.sb_tls_info;
1009 	if (tls == NULL) {
1010 		SOCKBUF_UNLOCK(&so->so_snd);
1011 		return (0);
1012 	}
1013 
1014 	if (tls->mode == mode) {
1015 		SOCKBUF_UNLOCK(&so->so_snd);
1016 		return (0);
1017 	}
1018 
1019 	tls = ktls_hold(tls);
1020 	SOCKBUF_UNLOCK(&so->so_snd);
1021 	INP_WUNLOCK(inp);
1022 
1023 	tls_new = ktls_clone_session(tls);
1024 
1025 	if (mode == TCP_TLS_MODE_IFNET)
1026 		error = ktls_try_ifnet(so, tls_new, true);
1027 	else
1028 		error = ktls_try_sw(so, tls_new);
1029 	if (error) {
1030 		counter_u64_add(ktls_switch_failed, 1);
1031 		ktls_free(tls_new);
1032 		ktls_free(tls);
1033 		INP_WLOCK(inp);
1034 		return (error);
1035 	}
1036 
1037 	error = sblock(&so->so_snd, SBL_WAIT);
1038 	if (error) {
1039 		counter_u64_add(ktls_switch_failed, 1);
1040 		ktls_free(tls_new);
1041 		ktls_free(tls);
1042 		INP_WLOCK(inp);
1043 		return (error);
1044 	}
1045 
1046 	/*
1047 	 * If we raced with another session change, keep the existing
1048 	 * session.
1049 	 */
1050 	if (tls != so->so_snd.sb_tls_info) {
1051 		counter_u64_add(ktls_switch_failed, 1);
1052 		sbunlock(&so->so_snd);
1053 		ktls_free(tls_new);
1054 		ktls_free(tls);
1055 		INP_WLOCK(inp);
1056 		return (EBUSY);
1057 	}
1058 
1059 	SOCKBUF_LOCK(&so->so_snd);
1060 	so->so_snd.sb_tls_info = tls_new;
1061 	if (tls_new->mode != TCP_TLS_MODE_SW)
1062 		so->so_snd.sb_flags |= SB_TLS_IFNET;
1063 	SOCKBUF_UNLOCK(&so->so_snd);
1064 	sbunlock(&so->so_snd);
1065 
1066 	/*
1067 	 * Drop two references on 'tls'.  The first is for the
1068 	 * ktls_hold() above.  The second drops the reference from the
1069 	 * socket buffer.
1070 	 */
1071 	KASSERT(tls->refcount >= 2, ("too few references on old session"));
1072 	ktls_free(tls);
1073 	ktls_free(tls);
1074 
1075 	if (mode == TCP_TLS_MODE_IFNET)
1076 		counter_u64_add(ktls_switch_to_ifnet, 1);
1077 	else
1078 		counter_u64_add(ktls_switch_to_sw, 1);
1079 
1080 	INP_WLOCK(inp);
1081 	return (0);
1082 }
1083 
1084 /*
1085  * Try to allocate a new TLS send tag.  This task is scheduled when
1086  * ip_output detects a route change while trying to transmit a packet
1087  * holding a TLS record.  If a new tag is allocated, replace the tag
1088  * in the TLS session.  Subsequent packets on the connection will use
1089  * the new tag.  If a new tag cannot be allocated, drop the
1090  * connection.
1091  */
1092 static void
1093 ktls_reset_send_tag(void *context, int pending)
1094 {
1095 	struct epoch_tracker et;
1096 	struct ktls_session *tls;
1097 	struct m_snd_tag *old, *new;
1098 	struct inpcb *inp;
1099 	struct tcpcb *tp;
1100 	int error;
1101 
1102 	MPASS(pending == 1);
1103 
1104 	tls = context;
1105 	inp = tls->inp;
1106 
1107 	/*
1108 	 * Free the old tag first before allocating a new one.
1109 	 * ip[6]_output_send() will treat a NULL send tag the same as
1110 	 * an ifp mismatch and drop packets until a new tag is
1111 	 * allocated.
1112 	 *
1113 	 * Write-lock the INP when changing tls->snd_tag since
1114 	 * ip[6]_output_send() holds a read-lock when reading the
1115 	 * pointer.
1116 	 */
1117 	INP_WLOCK(inp);
1118 	old = tls->snd_tag;
1119 	tls->snd_tag = NULL;
1120 	INP_WUNLOCK(inp);
1121 	if (old != NULL)
1122 		m_snd_tag_rele(old);
1123 
1124 	error = ktls_alloc_snd_tag(inp, tls, true, &new);
1125 
1126 	if (error == 0) {
1127 		INP_WLOCK(inp);
1128 		tls->snd_tag = new;
1129 		mtx_pool_lock(mtxpool_sleep, tls);
1130 		tls->reset_pending = false;
1131 		mtx_pool_unlock(mtxpool_sleep, tls);
1132 		if (!in_pcbrele_wlocked(inp))
1133 			INP_WUNLOCK(inp);
1134 
1135 		counter_u64_add(ktls_ifnet_reset, 1);
1136 
1137 		/*
1138 		 * XXX: Should we kick tcp_output explicitly now that
1139 		 * the send tag is fixed or just rely on timers?
1140 		 */
1141 	} else {
1142 		NET_EPOCH_ENTER(et);
1143 		INP_WLOCK(inp);
1144 		if (!in_pcbrele_wlocked(inp)) {
1145 			if (!(inp->inp_flags & INP_TIMEWAIT) &&
1146 			    !(inp->inp_flags & INP_DROPPED)) {
1147 				tp = intotcpcb(inp);
1148 				CURVNET_SET(tp->t_vnet);
1149 				tp = tcp_drop(tp, ECONNABORTED);
1150 				CURVNET_RESTORE();
1151 				if (tp != NULL)
1152 					INP_WUNLOCK(inp);
1153 				counter_u64_add(ktls_ifnet_reset_dropped, 1);
1154 			} else
1155 				INP_WUNLOCK(inp);
1156 		}
1157 		NET_EPOCH_EXIT(et);
1158 
1159 		counter_u64_add(ktls_ifnet_reset_failed, 1);
1160 
1161 		/*
1162 		 * Leave reset_pending true to avoid future tasks while
1163 		 * the socket goes away.
1164 		 */
1165 	}
1166 
1167 	ktls_free(tls);
1168 }
1169 
1170 int
1171 ktls_output_eagain(struct inpcb *inp, struct ktls_session *tls)
1172 {
1173 
1174 	if (inp == NULL)
1175 		return (ENOBUFS);
1176 
1177 	INP_LOCK_ASSERT(inp);
1178 
1179 	/*
1180 	 * See if we should schedule a task to update the send tag for
1181 	 * this session.
1182 	 */
1183 	mtx_pool_lock(mtxpool_sleep, tls);
1184 	if (!tls->reset_pending) {
1185 		(void) ktls_hold(tls);
1186 		in_pcbref(inp);
1187 		tls->inp = inp;
1188 		tls->reset_pending = true;
1189 		taskqueue_enqueue(taskqueue_thread, &tls->reset_tag_task);
1190 	}
1191 	mtx_pool_unlock(mtxpool_sleep, tls);
1192 	return (ENOBUFS);
1193 }
1194 #endif
1195 
1196 void
1197 ktls_destroy(struct ktls_session *tls)
1198 {
1199 	struct rm_priotracker prio;
1200 
1201 	ktls_cleanup(tls);
1202 	if (tls->be != NULL && ktls_allow_unload) {
1203 		rm_rlock(&ktls_backends_lock, &prio);
1204 		tls->be->use_count--;
1205 		rm_runlock(&ktls_backends_lock, &prio);
1206 	}
1207 	uma_zfree(ktls_session_zone, tls);
1208 }
1209 
1210 void
1211 ktls_seq(struct sockbuf *sb, struct mbuf *m)
1212 {
1213 	struct mbuf_ext_pgs *pgs;
1214 
1215 	for (; m != NULL; m = m->m_next) {
1216 		KASSERT((m->m_flags & M_NOMAP) != 0,
1217 		    ("ktls_seq: mapped mbuf %p", m));
1218 
1219 		pgs = &m->m_ext_pgs;
1220 		pgs->seqno = sb->sb_tls_seqno;
1221 		sb->sb_tls_seqno++;
1222 	}
1223 }
1224 
1225 /*
1226  * Add TLS framing (headers and trailers) to a chain of mbufs.  Each
1227  * mbuf in the chain must be an unmapped mbuf.  The payload of the
1228  * mbuf must be populated with the payload of each TLS record.
1229  *
1230  * The record_type argument specifies the TLS record type used when
1231  * populating the TLS header.
1232  *
1233  * The enq_count argument on return is set to the number of pages of
1234  * payload data for this entire chain that need to be encrypted via SW
1235  * encryption.  The returned value should be passed to ktls_enqueue
1236  * when scheduling encryption of this chain of mbufs.
1237  */
1238 void
1239 ktls_frame(struct mbuf *top, struct ktls_session *tls, int *enq_cnt,
1240     uint8_t record_type)
1241 {
1242 	struct tls_record_layer *tlshdr;
1243 	struct mbuf *m;
1244 	struct mbuf_ext_pgs *pgs;
1245 	uint64_t *noncep;
1246 	uint16_t tls_len;
1247 	int maxlen;
1248 
1249 	maxlen = tls->params.max_frame_len;
1250 	*enq_cnt = 0;
1251 	for (m = top; m != NULL; m = m->m_next) {
1252 		/*
1253 		 * All mbufs in the chain should be non-empty TLS
1254 		 * records whose payload does not exceed the maximum
1255 		 * frame length.
1256 		 */
1257 		KASSERT(m->m_len <= maxlen && m->m_len > 0,
1258 		    ("ktls_frame: m %p len %d\n", m, m->m_len));
1259 		/*
1260 		 * TLS frames require unmapped mbufs to store session
1261 		 * info.
1262 		 */
1263 		KASSERT((m->m_flags & M_NOMAP) != 0,
1264 		    ("ktls_frame: mapped mbuf %p (top = %p)\n", m, top));
1265 
1266 		tls_len = m->m_len;
1267 		pgs = &m->m_ext_pgs;
1268 
1269 		/* Save a reference to the session. */
1270 		pgs->tls = ktls_hold(tls);
1271 
1272 		pgs->hdr_len = tls->params.tls_hlen;
1273 		pgs->trail_len = tls->params.tls_tlen;
1274 		if (tls->params.cipher_algorithm == CRYPTO_AES_CBC) {
1275 			int bs, delta;
1276 
1277 			/*
1278 			 * AES-CBC pads messages to a multiple of the
1279 			 * block size.  Note that the padding is
1280 			 * applied after the digest and the encryption
1281 			 * is done on the "plaintext || mac || padding".
1282 			 * At least one byte of padding is always
1283 			 * present.
1284 			 *
1285 			 * Compute the final trailer length assuming
1286 			 * at most one block of padding.
1287 			 * tls->params.sb_tls_tlen is the maximum
1288 			 * possible trailer length (padding + digest).
1289 			 * delta holds the number of excess padding
1290 			 * bytes if the maximum were used.  Those
1291 			 * extra bytes are removed.
1292 			 */
1293 			bs = tls->params.tls_bs;
1294 			delta = (tls_len + tls->params.tls_tlen) & (bs - 1);
1295 			pgs->trail_len -= delta;
1296 		}
1297 		m->m_len += pgs->hdr_len + pgs->trail_len;
1298 
1299 		/* Populate the TLS header. */
1300 		tlshdr = (void *)pgs->m_epg_hdr;
1301 		tlshdr->tls_vmajor = tls->params.tls_vmajor;
1302 
1303 		/*
1304 		 * TLS 1.3 masquarades as TLS 1.2 with a record type
1305 		 * of TLS_RLTYPE_APP.
1306 		 */
1307 		if (tls->params.tls_vminor == TLS_MINOR_VER_THREE &&
1308 		    tls->params.tls_vmajor == TLS_MAJOR_VER_ONE) {
1309 			tlshdr->tls_vminor = TLS_MINOR_VER_TWO;
1310 			tlshdr->tls_type = TLS_RLTYPE_APP;
1311 			/* save the real record type for later */
1312 			pgs->record_type = record_type;
1313 			pgs->m_epg_trail[0] = record_type;
1314 		} else {
1315 			tlshdr->tls_vminor = tls->params.tls_vminor;
1316 			tlshdr->tls_type = record_type;
1317 		}
1318 		tlshdr->tls_length = htons(m->m_len - sizeof(*tlshdr));
1319 
1320 		/*
1321 		 * Store nonces / explicit IVs after the end of the
1322 		 * TLS header.
1323 		 *
1324 		 * For GCM with TLS 1.2, an 8 byte nonce is copied
1325 		 * from the end of the IV.  The nonce is then
1326 		 * incremented for use by the next record.
1327 		 *
1328 		 * For CBC, a random nonce is inserted for TLS 1.1+.
1329 		 */
1330 		if (tls->params.cipher_algorithm == CRYPTO_AES_NIST_GCM_16 &&
1331 		    tls->params.tls_vminor == TLS_MINOR_VER_TWO) {
1332 			noncep = (uint64_t *)(tls->params.iv + 8);
1333 			be64enc(tlshdr + 1, *noncep);
1334 			(*noncep)++;
1335 		} else if (tls->params.cipher_algorithm == CRYPTO_AES_CBC &&
1336 		    tls->params.tls_vminor >= TLS_MINOR_VER_ONE)
1337 			arc4rand(tlshdr + 1, AES_BLOCK_LEN, 0);
1338 
1339 		/*
1340 		 * When using SW encryption, mark the mbuf not ready.
1341 		 * It will be marked ready via sbready() after the
1342 		 * record has been encrypted.
1343 		 *
1344 		 * When using ifnet TLS, unencrypted TLS records are
1345 		 * sent down the stack to the NIC.
1346 		 */
1347 		if (tls->mode == TCP_TLS_MODE_SW) {
1348 			m->m_flags |= M_NOTREADY;
1349 			pgs->nrdy = pgs->npgs;
1350 			*enq_cnt += pgs->npgs;
1351 		}
1352 	}
1353 }
1354 
1355 void
1356 ktls_enqueue_to_free(struct mbuf_ext_pgs *pgs)
1357 {
1358 	struct ktls_wq *wq;
1359 	bool running;
1360 
1361 	/* Mark it for freeing. */
1362 	pgs->mbuf = NULL;
1363 	wq = &ktls_wq[pgs->tls->wq_index];
1364 	mtx_lock(&wq->mtx);
1365 	STAILQ_INSERT_TAIL(&wq->head, pgs, stailq);
1366 	running = wq->running;
1367 	mtx_unlock(&wq->mtx);
1368 	if (!running)
1369 		wakeup(wq);
1370 }
1371 
1372 void
1373 ktls_enqueue(struct mbuf *m, struct socket *so, int page_count)
1374 {
1375 	struct mbuf_ext_pgs *pgs;
1376 	struct ktls_wq *wq;
1377 	bool running;
1378 
1379 	KASSERT(((m->m_flags & (M_NOMAP | M_NOTREADY)) ==
1380 	    (M_NOMAP | M_NOTREADY)),
1381 	    ("ktls_enqueue: %p not unready & nomap mbuf\n", m));
1382 	KASSERT(page_count != 0, ("enqueueing TLS mbuf with zero page count"));
1383 
1384 	pgs = &m->m_ext_pgs;
1385 
1386 	KASSERT(pgs->tls->mode == TCP_TLS_MODE_SW, ("!SW TLS mbuf"));
1387 
1388 	pgs->enc_cnt = page_count;
1389 	pgs->mbuf = m;
1390 
1391 	/*
1392 	 * Save a pointer to the socket.  The caller is responsible
1393 	 * for taking an additional reference via soref().
1394 	 */
1395 	pgs->so = so;
1396 
1397 	wq = &ktls_wq[pgs->tls->wq_index];
1398 	mtx_lock(&wq->mtx);
1399 	STAILQ_INSERT_TAIL(&wq->head, pgs, stailq);
1400 	running = wq->running;
1401 	mtx_unlock(&wq->mtx);
1402 	if (!running)
1403 		wakeup(wq);
1404 	counter_u64_add(ktls_cnt_on, 1);
1405 }
1406 
1407 static __noinline void
1408 ktls_encrypt(struct mbuf_ext_pgs *pgs)
1409 {
1410 	struct ktls_session *tls;
1411 	struct socket *so;
1412 	struct mbuf *m, *top;
1413 	vm_paddr_t parray[1 + btoc(TLS_MAX_MSG_SIZE_V10_2)];
1414 	struct iovec src_iov[1 + btoc(TLS_MAX_MSG_SIZE_V10_2)];
1415 	struct iovec dst_iov[1 + btoc(TLS_MAX_MSG_SIZE_V10_2)];
1416 	vm_page_t pg;
1417 	int error, i, len, npages, off, total_pages;
1418 	bool is_anon;
1419 
1420 	so = pgs->so;
1421 	tls = pgs->tls;
1422 	top = pgs->mbuf;
1423 	KASSERT(tls != NULL, ("tls = NULL, top = %p, pgs = %p\n", top, pgs));
1424 	KASSERT(so != NULL, ("so = NULL, top = %p, pgs = %p\n", top, pgs));
1425 #ifdef INVARIANTS
1426 	pgs->so = NULL;
1427 	pgs->mbuf = NULL;
1428 #endif
1429 	total_pages = pgs->enc_cnt;
1430 	npages = 0;
1431 
1432 	/*
1433 	 * Encrypt the TLS records in the chain of mbufs starting with
1434 	 * 'top'.  'total_pages' gives us a total count of pages and is
1435 	 * used to know when we have finished encrypting the TLS
1436 	 * records originally queued with 'top'.
1437 	 *
1438 	 * NB: These mbufs are queued in the socket buffer and
1439 	 * 'm_next' is traversing the mbufs in the socket buffer.  The
1440 	 * socket buffer lock is not held while traversing this chain.
1441 	 * Since the mbufs are all marked M_NOTREADY their 'm_next'
1442 	 * pointers should be stable.  However, the 'm_next' of the
1443 	 * last mbuf encrypted is not necessarily NULL.  It can point
1444 	 * to other mbufs appended while 'top' was on the TLS work
1445 	 * queue.
1446 	 *
1447 	 * Each mbuf holds an entire TLS record.
1448 	 */
1449 	error = 0;
1450 	for (m = top; npages != total_pages; m = m->m_next) {
1451 		pgs = &m->m_ext_pgs;
1452 
1453 		KASSERT(pgs->tls == tls,
1454 		    ("different TLS sessions in a single mbuf chain: %p vs %p",
1455 		    tls, pgs->tls));
1456 		KASSERT((m->m_flags & (M_NOMAP | M_NOTREADY)) ==
1457 		    (M_NOMAP | M_NOTREADY),
1458 		    ("%p not unready & nomap mbuf (top = %p)\n", m, top));
1459 		KASSERT(npages + pgs->npgs <= total_pages,
1460 		    ("page count mismatch: top %p, total_pages %d, m %p", top,
1461 		    total_pages, m));
1462 
1463 		/*
1464 		 * Generate source and destination ivoecs to pass to
1465 		 * the SW encryption backend.  For writable mbufs, the
1466 		 * destination iovec is a copy of the source and
1467 		 * encryption is done in place.  For file-backed mbufs
1468 		 * (from sendfile), anonymous wired pages are
1469 		 * allocated and assigned to the destination iovec.
1470 		 */
1471 		is_anon = (pgs->flags & MBUF_PEXT_FLAG_ANON) != 0;
1472 
1473 		off = pgs->first_pg_off;
1474 		for (i = 0; i < pgs->npgs; i++, off = 0) {
1475 			len = mbuf_ext_pg_len(pgs, i, off);
1476 			src_iov[i].iov_len = len;
1477 			src_iov[i].iov_base =
1478 			    (char *)(void *)PHYS_TO_DMAP(pgs->m_epg_pa[i]) +
1479 				off;
1480 
1481 			if (is_anon) {
1482 				dst_iov[i].iov_base = src_iov[i].iov_base;
1483 				dst_iov[i].iov_len = src_iov[i].iov_len;
1484 				continue;
1485 			}
1486 retry_page:
1487 			pg = vm_page_alloc(NULL, 0, VM_ALLOC_NORMAL |
1488 			    VM_ALLOC_NOOBJ | VM_ALLOC_NODUMP | VM_ALLOC_WIRED);
1489 			if (pg == NULL) {
1490 				vm_wait(NULL);
1491 				goto retry_page;
1492 			}
1493 			parray[i] = VM_PAGE_TO_PHYS(pg);
1494 			dst_iov[i].iov_base =
1495 			    (char *)(void *)PHYS_TO_DMAP(parray[i]) + off;
1496 			dst_iov[i].iov_len = len;
1497 		}
1498 
1499 		npages += i;
1500 
1501 		error = (*tls->sw_encrypt)(tls,
1502 		    (const struct tls_record_layer *)pgs->m_epg_hdr,
1503 		    pgs->m_epg_trail, src_iov, dst_iov, i, pgs->seqno,
1504 		    pgs->record_type);
1505 		if (error) {
1506 			counter_u64_add(ktls_offload_failed_crypto, 1);
1507 			break;
1508 		}
1509 
1510 		/*
1511 		 * For file-backed mbufs, release the file-backed
1512 		 * pages and replace them in the ext_pgs array with
1513 		 * the anonymous wired pages allocated above.
1514 		 */
1515 		if (!is_anon) {
1516 			/* Free the old pages. */
1517 			m->m_ext.ext_free(m);
1518 
1519 			/* Replace them with the new pages. */
1520 			for (i = 0; i < pgs->npgs; i++)
1521 				pgs->m_epg_pa[i] = parray[i];
1522 
1523 			/* Use the basic free routine. */
1524 			m->m_ext.ext_free = mb_free_mext_pgs;
1525 
1526 			/* Pages are now writable. */
1527 			pgs->flags |= MBUF_PEXT_FLAG_ANON;
1528 		}
1529 
1530 		/*
1531 		 * Drop a reference to the session now that it is no
1532 		 * longer needed.  Existing code depends on encrypted
1533 		 * records having no associated session vs
1534 		 * yet-to-be-encrypted records having an associated
1535 		 * session.
1536 		 */
1537 		pgs->tls = NULL;
1538 		ktls_free(tls);
1539 	}
1540 
1541 	CURVNET_SET(so->so_vnet);
1542 	if (error == 0) {
1543 		(void)(*so->so_proto->pr_usrreqs->pru_ready)(so, top, npages);
1544 	} else {
1545 		so->so_proto->pr_usrreqs->pru_abort(so);
1546 		so->so_error = EIO;
1547 		mb_free_notready(top, total_pages);
1548 	}
1549 
1550 	SOCK_LOCK(so);
1551 	sorele(so);
1552 	CURVNET_RESTORE();
1553 }
1554 
1555 static void
1556 ktls_work_thread(void *ctx)
1557 {
1558 	struct ktls_wq *wq = ctx;
1559 	struct mbuf_ext_pgs *p, *n;
1560 	struct ktls_session *tls;
1561 	struct mbuf *m;
1562 	STAILQ_HEAD(, mbuf_ext_pgs) local_head;
1563 
1564 #if defined(__aarch64__) || defined(__amd64__) || defined(__i386__)
1565 	fpu_kern_thread(0);
1566 #endif
1567 	for (;;) {
1568 		mtx_lock(&wq->mtx);
1569 		while (STAILQ_EMPTY(&wq->head)) {
1570 			wq->running = false;
1571 			mtx_sleep(wq, &wq->mtx, 0, "-", 0);
1572 			wq->running = true;
1573 		}
1574 
1575 		STAILQ_INIT(&local_head);
1576 		STAILQ_CONCAT(&local_head, &wq->head);
1577 		mtx_unlock(&wq->mtx);
1578 
1579 		STAILQ_FOREACH_SAFE(p, &local_head, stailq, n) {
1580 			if (p->mbuf != NULL) {
1581 				ktls_encrypt(p);
1582 				counter_u64_add(ktls_cnt_on, -1);
1583 			} else {
1584 				tls = p->tls;
1585 				ktls_free(tls);
1586 				m = __containerof(p, struct mbuf, m_ext_pgs);
1587 				uma_zfree(zone_mbuf, m);
1588 			}
1589 		}
1590 	}
1591 }
1592