1 /* 2 * Copyright (c) 2016-2017, Mellanox Technologies. All rights reserved. 3 * Copyright (c) 2016-2017, Dave Watson <davejwatson@fb.com>. All rights reserved. 4 * 5 * This software is available to you under a choice of one of two 6 * licenses. You may choose to be licensed under the terms of the GNU 7 * General Public License (GPL) Version 2, available from the file 8 * COPYING in the main directory of this source tree, or the 9 * OpenIB.org BSD license below: 10 * 11 * Redistribution and use in source and binary forms, with or 12 * without modification, are permitted provided that the following 13 * conditions are met: 14 * 15 * - Redistributions of source code must retain the above 16 * copyright notice, this list of conditions and the following 17 * disclaimer. 18 * 19 * - Redistributions in binary form must reproduce the above 20 * copyright notice, this list of conditions and the following 21 * disclaimer in the documentation and/or other materials 22 * provided with the distribution. 23 * 24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 25 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 27 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 28 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 29 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 30 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 31 * SOFTWARE. 32 */ 33 34 #include <linux/module.h> 35 36 #include <net/tcp.h> 37 #include <net/inet_common.h> 38 #include <linux/highmem.h> 39 #include <linux/netdevice.h> 40 #include <linux/sched/signal.h> 41 #include <linux/inetdevice.h> 42 43 #include <net/tls.h> 44 45 MODULE_AUTHOR("Mellanox Technologies"); 46 MODULE_DESCRIPTION("Transport Layer Security Support"); 47 MODULE_LICENSE("Dual BSD/GPL"); 48 49 enum { 50 TLSV4, 51 TLSV6, 52 TLS_NUM_PROTS, 53 }; 54 55 enum { 56 TLS_BASE, 57 TLS_SW_TX, 58 TLS_SW_RX, 59 TLS_SW_RXTX, 60 TLS_HW_RECORD, 61 TLS_NUM_CONFIG, 62 }; 63 64 static struct proto *saved_tcpv6_prot; 65 static DEFINE_MUTEX(tcpv6_prot_mutex); 66 static LIST_HEAD(device_list); 67 static DEFINE_MUTEX(device_mutex); 68 static struct proto tls_prots[TLS_NUM_PROTS][TLS_NUM_CONFIG]; 69 static struct proto_ops tls_sw_proto_ops; 70 71 static inline void update_sk_prot(struct sock *sk, struct tls_context *ctx) 72 { 73 int ip_ver = sk->sk_family == AF_INET6 ? TLSV6 : TLSV4; 74 75 sk->sk_prot = &tls_prots[ip_ver][ctx->conf]; 76 } 77 78 int wait_on_pending_writer(struct sock *sk, long *timeo) 79 { 80 int rc = 0; 81 DEFINE_WAIT_FUNC(wait, woken_wake_function); 82 83 add_wait_queue(sk_sleep(sk), &wait); 84 while (1) { 85 if (!*timeo) { 86 rc = -EAGAIN; 87 break; 88 } 89 90 if (signal_pending(current)) { 91 rc = sock_intr_errno(*timeo); 92 break; 93 } 94 95 if (sk_wait_event(sk, timeo, !sk->sk_write_pending, &wait)) 96 break; 97 } 98 remove_wait_queue(sk_sleep(sk), &wait); 99 return rc; 100 } 101 102 int tls_push_sg(struct sock *sk, 103 struct tls_context *ctx, 104 struct scatterlist *sg, 105 u16 first_offset, 106 int flags) 107 { 108 int sendpage_flags = flags | MSG_SENDPAGE_NOTLAST; 109 int ret = 0; 110 struct page *p; 111 size_t size; 112 int offset = first_offset; 113 114 size = sg->length - offset; 115 offset += sg->offset; 116 117 while (1) { 118 if (sg_is_last(sg)) 119 sendpage_flags = flags; 120 121 /* is sending application-limited? */ 122 tcp_rate_check_app_limited(sk); 123 p = sg_page(sg); 124 retry: 125 ret = do_tcp_sendpages(sk, p, offset, size, sendpage_flags); 126 127 if (ret != size) { 128 if (ret > 0) { 129 offset += ret; 130 size -= ret; 131 goto retry; 132 } 133 134 offset -= sg->offset; 135 ctx->partially_sent_offset = offset; 136 ctx->partially_sent_record = (void *)sg; 137 return ret; 138 } 139 140 put_page(p); 141 sk_mem_uncharge(sk, sg->length); 142 sg = sg_next(sg); 143 if (!sg) 144 break; 145 146 offset = sg->offset; 147 size = sg->length; 148 } 149 150 clear_bit(TLS_PENDING_CLOSED_RECORD, &ctx->flags); 151 152 return 0; 153 } 154 155 static int tls_handle_open_record(struct sock *sk, int flags) 156 { 157 struct tls_context *ctx = tls_get_ctx(sk); 158 159 if (tls_is_pending_open_record(ctx)) 160 return ctx->push_pending_record(sk, flags); 161 162 return 0; 163 } 164 165 int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg, 166 unsigned char *record_type) 167 { 168 struct cmsghdr *cmsg; 169 int rc = -EINVAL; 170 171 for_each_cmsghdr(cmsg, msg) { 172 if (!CMSG_OK(msg, cmsg)) 173 return -EINVAL; 174 if (cmsg->cmsg_level != SOL_TLS) 175 continue; 176 177 switch (cmsg->cmsg_type) { 178 case TLS_SET_RECORD_TYPE: 179 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*record_type))) 180 return -EINVAL; 181 182 if (msg->msg_flags & MSG_MORE) 183 return -EINVAL; 184 185 rc = tls_handle_open_record(sk, msg->msg_flags); 186 if (rc) 187 return rc; 188 189 *record_type = *(unsigned char *)CMSG_DATA(cmsg); 190 rc = 0; 191 break; 192 default: 193 return -EINVAL; 194 } 195 } 196 197 return rc; 198 } 199 200 int tls_push_pending_closed_record(struct sock *sk, struct tls_context *ctx, 201 int flags, long *timeo) 202 { 203 struct scatterlist *sg; 204 u16 offset; 205 206 if (!tls_is_partially_sent_record(ctx)) 207 return ctx->push_pending_record(sk, flags); 208 209 sg = ctx->partially_sent_record; 210 offset = ctx->partially_sent_offset; 211 212 ctx->partially_sent_record = NULL; 213 return tls_push_sg(sk, ctx, sg, offset, flags); 214 } 215 216 static void tls_write_space(struct sock *sk) 217 { 218 struct tls_context *ctx = tls_get_ctx(sk); 219 220 if (!sk->sk_write_pending && tls_is_pending_closed_record(ctx)) { 221 gfp_t sk_allocation = sk->sk_allocation; 222 int rc; 223 long timeo = 0; 224 225 sk->sk_allocation = GFP_ATOMIC; 226 rc = tls_push_pending_closed_record(sk, ctx, 227 MSG_DONTWAIT | 228 MSG_NOSIGNAL, 229 &timeo); 230 sk->sk_allocation = sk_allocation; 231 232 if (rc < 0) 233 return; 234 } 235 236 ctx->sk_write_space(sk); 237 } 238 239 static void tls_sk_proto_close(struct sock *sk, long timeout) 240 { 241 struct tls_context *ctx = tls_get_ctx(sk); 242 long timeo = sock_sndtimeo(sk, 0); 243 void (*sk_proto_close)(struct sock *sk, long timeout); 244 245 lock_sock(sk); 246 sk_proto_close = ctx->sk_proto_close; 247 248 if (ctx->conf == TLS_HW_RECORD) 249 goto skip_tx_cleanup; 250 251 if (ctx->conf == TLS_BASE) { 252 kfree(ctx); 253 ctx = NULL; 254 goto skip_tx_cleanup; 255 } 256 257 if (!tls_complete_pending_work(sk, ctx, 0, &timeo)) 258 tls_handle_open_record(sk, 0); 259 260 if (ctx->partially_sent_record) { 261 struct scatterlist *sg = ctx->partially_sent_record; 262 263 while (1) { 264 put_page(sg_page(sg)); 265 sk_mem_uncharge(sk, sg->length); 266 267 if (sg_is_last(sg)) 268 break; 269 sg++; 270 } 271 } 272 273 kfree(ctx->tx.rec_seq); 274 kfree(ctx->tx.iv); 275 kfree(ctx->rx.rec_seq); 276 kfree(ctx->rx.iv); 277 278 if (ctx->conf == TLS_SW_TX || 279 ctx->conf == TLS_SW_RX || 280 ctx->conf == TLS_SW_RXTX) { 281 tls_sw_free_resources(sk); 282 } 283 284 skip_tx_cleanup: 285 release_sock(sk); 286 sk_proto_close(sk, timeout); 287 /* free ctx for TLS_HW_RECORD, used by tcp_set_state 288 * for sk->sk_prot->unhash [tls_hw_unhash] 289 */ 290 if (ctx && ctx->conf == TLS_HW_RECORD) 291 kfree(ctx); 292 } 293 294 static int do_tls_getsockopt_tx(struct sock *sk, char __user *optval, 295 int __user *optlen) 296 { 297 int rc = 0; 298 struct tls_context *ctx = tls_get_ctx(sk); 299 struct tls_crypto_info *crypto_info; 300 int len; 301 302 if (get_user(len, optlen)) 303 return -EFAULT; 304 305 if (!optval || (len < sizeof(*crypto_info))) { 306 rc = -EINVAL; 307 goto out; 308 } 309 310 if (!ctx) { 311 rc = -EBUSY; 312 goto out; 313 } 314 315 /* get user crypto info */ 316 crypto_info = &ctx->crypto_send; 317 318 if (!TLS_CRYPTO_INFO_READY(crypto_info)) { 319 rc = -EBUSY; 320 goto out; 321 } 322 323 if (len == sizeof(*crypto_info)) { 324 if (copy_to_user(optval, crypto_info, sizeof(*crypto_info))) 325 rc = -EFAULT; 326 goto out; 327 } 328 329 switch (crypto_info->cipher_type) { 330 case TLS_CIPHER_AES_GCM_128: { 331 struct tls12_crypto_info_aes_gcm_128 * 332 crypto_info_aes_gcm_128 = 333 container_of(crypto_info, 334 struct tls12_crypto_info_aes_gcm_128, 335 info); 336 337 if (len != sizeof(*crypto_info_aes_gcm_128)) { 338 rc = -EINVAL; 339 goto out; 340 } 341 lock_sock(sk); 342 memcpy(crypto_info_aes_gcm_128->iv, 343 ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, 344 TLS_CIPHER_AES_GCM_128_IV_SIZE); 345 memcpy(crypto_info_aes_gcm_128->rec_seq, ctx->tx.rec_seq, 346 TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE); 347 release_sock(sk); 348 if (copy_to_user(optval, 349 crypto_info_aes_gcm_128, 350 sizeof(*crypto_info_aes_gcm_128))) 351 rc = -EFAULT; 352 break; 353 } 354 default: 355 rc = -EINVAL; 356 } 357 358 out: 359 return rc; 360 } 361 362 static int do_tls_getsockopt(struct sock *sk, int optname, 363 char __user *optval, int __user *optlen) 364 { 365 int rc = 0; 366 367 switch (optname) { 368 case TLS_TX: 369 rc = do_tls_getsockopt_tx(sk, optval, optlen); 370 break; 371 default: 372 rc = -ENOPROTOOPT; 373 break; 374 } 375 return rc; 376 } 377 378 static int tls_getsockopt(struct sock *sk, int level, int optname, 379 char __user *optval, int __user *optlen) 380 { 381 struct tls_context *ctx = tls_get_ctx(sk); 382 383 if (level != SOL_TLS) 384 return ctx->getsockopt(sk, level, optname, optval, optlen); 385 386 return do_tls_getsockopt(sk, optname, optval, optlen); 387 } 388 389 static int do_tls_setsockopt_conf(struct sock *sk, char __user *optval, 390 unsigned int optlen, int tx) 391 { 392 struct tls_crypto_info *crypto_info; 393 struct tls_context *ctx = tls_get_ctx(sk); 394 int rc = 0; 395 int conf; 396 397 if (!optval || (optlen < sizeof(*crypto_info))) { 398 rc = -EINVAL; 399 goto out; 400 } 401 402 if (tx) 403 crypto_info = &ctx->crypto_send; 404 else 405 crypto_info = &ctx->crypto_recv; 406 407 /* Currently we don't support set crypto info more than one time */ 408 if (TLS_CRYPTO_INFO_READY(crypto_info)) { 409 rc = -EBUSY; 410 goto out; 411 } 412 413 rc = copy_from_user(crypto_info, optval, sizeof(*crypto_info)); 414 if (rc) { 415 rc = -EFAULT; 416 goto err_crypto_info; 417 } 418 419 /* check version */ 420 if (crypto_info->version != TLS_1_2_VERSION) { 421 rc = -ENOTSUPP; 422 goto err_crypto_info; 423 } 424 425 switch (crypto_info->cipher_type) { 426 case TLS_CIPHER_AES_GCM_128: { 427 if (optlen != sizeof(struct tls12_crypto_info_aes_gcm_128)) { 428 rc = -EINVAL; 429 goto err_crypto_info; 430 } 431 rc = copy_from_user(crypto_info + 1, optval + sizeof(*crypto_info), 432 optlen - sizeof(*crypto_info)); 433 if (rc) { 434 rc = -EFAULT; 435 goto err_crypto_info; 436 } 437 break; 438 } 439 default: 440 rc = -EINVAL; 441 goto err_crypto_info; 442 } 443 444 /* currently SW is default, we will have ethtool in future */ 445 if (tx) { 446 rc = tls_set_sw_offload(sk, ctx, 1); 447 if (ctx->conf == TLS_SW_RX) 448 conf = TLS_SW_RXTX; 449 else 450 conf = TLS_SW_TX; 451 } else { 452 rc = tls_set_sw_offload(sk, ctx, 0); 453 if (ctx->conf == TLS_SW_TX) 454 conf = TLS_SW_RXTX; 455 else 456 conf = TLS_SW_RX; 457 } 458 459 if (rc) 460 goto err_crypto_info; 461 462 ctx->conf = conf; 463 update_sk_prot(sk, ctx); 464 if (tx) { 465 ctx->sk_write_space = sk->sk_write_space; 466 sk->sk_write_space = tls_write_space; 467 } else { 468 sk->sk_socket->ops = &tls_sw_proto_ops; 469 } 470 goto out; 471 472 err_crypto_info: 473 memset(crypto_info, 0, sizeof(*crypto_info)); 474 out: 475 return rc; 476 } 477 478 static int do_tls_setsockopt(struct sock *sk, int optname, 479 char __user *optval, unsigned int optlen) 480 { 481 int rc = 0; 482 483 switch (optname) { 484 case TLS_TX: 485 case TLS_RX: 486 lock_sock(sk); 487 rc = do_tls_setsockopt_conf(sk, optval, optlen, 488 optname == TLS_TX); 489 release_sock(sk); 490 break; 491 default: 492 rc = -ENOPROTOOPT; 493 break; 494 } 495 return rc; 496 } 497 498 static int tls_setsockopt(struct sock *sk, int level, int optname, 499 char __user *optval, unsigned int optlen) 500 { 501 struct tls_context *ctx = tls_get_ctx(sk); 502 503 if (level != SOL_TLS) 504 return ctx->setsockopt(sk, level, optname, optval, optlen); 505 506 return do_tls_setsockopt(sk, optname, optval, optlen); 507 } 508 509 static struct tls_context *create_ctx(struct sock *sk) 510 { 511 struct inet_connection_sock *icsk = inet_csk(sk); 512 struct tls_context *ctx; 513 514 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); 515 if (!ctx) 516 return NULL; 517 518 icsk->icsk_ulp_data = ctx; 519 return ctx; 520 } 521 522 static int tls_hw_prot(struct sock *sk) 523 { 524 struct tls_context *ctx; 525 struct tls_device *dev; 526 int rc = 0; 527 528 mutex_lock(&device_mutex); 529 list_for_each_entry(dev, &device_list, dev_list) { 530 if (dev->feature && dev->feature(dev)) { 531 ctx = create_ctx(sk); 532 if (!ctx) 533 goto out; 534 535 ctx->hash = sk->sk_prot->hash; 536 ctx->unhash = sk->sk_prot->unhash; 537 ctx->sk_proto_close = sk->sk_prot->close; 538 ctx->conf = TLS_HW_RECORD; 539 update_sk_prot(sk, ctx); 540 rc = 1; 541 break; 542 } 543 } 544 out: 545 mutex_unlock(&device_mutex); 546 return rc; 547 } 548 549 static void tls_hw_unhash(struct sock *sk) 550 { 551 struct tls_context *ctx = tls_get_ctx(sk); 552 struct tls_device *dev; 553 554 mutex_lock(&device_mutex); 555 list_for_each_entry(dev, &device_list, dev_list) { 556 if (dev->unhash) 557 dev->unhash(dev, sk); 558 } 559 mutex_unlock(&device_mutex); 560 ctx->unhash(sk); 561 } 562 563 static int tls_hw_hash(struct sock *sk) 564 { 565 struct tls_context *ctx = tls_get_ctx(sk); 566 struct tls_device *dev; 567 int err; 568 569 err = ctx->hash(sk); 570 mutex_lock(&device_mutex); 571 list_for_each_entry(dev, &device_list, dev_list) { 572 if (dev->hash) 573 err |= dev->hash(dev, sk); 574 } 575 mutex_unlock(&device_mutex); 576 577 if (err) 578 tls_hw_unhash(sk); 579 return err; 580 } 581 582 static void build_protos(struct proto *prot, struct proto *base) 583 { 584 prot[TLS_BASE] = *base; 585 prot[TLS_BASE].setsockopt = tls_setsockopt; 586 prot[TLS_BASE].getsockopt = tls_getsockopt; 587 prot[TLS_BASE].close = tls_sk_proto_close; 588 589 prot[TLS_SW_TX] = prot[TLS_BASE]; 590 prot[TLS_SW_TX].sendmsg = tls_sw_sendmsg; 591 prot[TLS_SW_TX].sendpage = tls_sw_sendpage; 592 593 prot[TLS_SW_RX] = prot[TLS_BASE]; 594 prot[TLS_SW_RX].recvmsg = tls_sw_recvmsg; 595 prot[TLS_SW_RX].close = tls_sk_proto_close; 596 597 prot[TLS_SW_RXTX] = prot[TLS_SW_TX]; 598 prot[TLS_SW_RXTX].recvmsg = tls_sw_recvmsg; 599 prot[TLS_SW_RXTX].close = tls_sk_proto_close; 600 601 prot[TLS_HW_RECORD] = *base; 602 prot[TLS_HW_RECORD].hash = tls_hw_hash; 603 prot[TLS_HW_RECORD].unhash = tls_hw_unhash; 604 prot[TLS_HW_RECORD].close = tls_sk_proto_close; 605 } 606 607 static int tls_init(struct sock *sk) 608 { 609 int ip_ver = sk->sk_family == AF_INET6 ? TLSV6 : TLSV4; 610 struct tls_context *ctx; 611 int rc = 0; 612 613 if (tls_hw_prot(sk)) 614 goto out; 615 616 /* The TLS ulp is currently supported only for TCP sockets 617 * in ESTABLISHED state. 618 * Supporting sockets in LISTEN state will require us 619 * to modify the accept implementation to clone rather then 620 * share the ulp context. 621 */ 622 if (sk->sk_state != TCP_ESTABLISHED) 623 return -ENOTSUPP; 624 625 /* allocate tls context */ 626 ctx = create_ctx(sk); 627 if (!ctx) { 628 rc = -ENOMEM; 629 goto out; 630 } 631 ctx->setsockopt = sk->sk_prot->setsockopt; 632 ctx->getsockopt = sk->sk_prot->getsockopt; 633 ctx->sk_proto_close = sk->sk_prot->close; 634 635 /* Build IPv6 TLS whenever the address of tcpv6_prot changes */ 636 if (ip_ver == TLSV6 && 637 unlikely(sk->sk_prot != smp_load_acquire(&saved_tcpv6_prot))) { 638 mutex_lock(&tcpv6_prot_mutex); 639 if (likely(sk->sk_prot != saved_tcpv6_prot)) { 640 build_protos(tls_prots[TLSV6], sk->sk_prot); 641 smp_store_release(&saved_tcpv6_prot, sk->sk_prot); 642 } 643 mutex_unlock(&tcpv6_prot_mutex); 644 } 645 646 ctx->conf = TLS_BASE; 647 update_sk_prot(sk, ctx); 648 out: 649 return rc; 650 } 651 652 void tls_register_device(struct tls_device *device) 653 { 654 mutex_lock(&device_mutex); 655 list_add_tail(&device->dev_list, &device_list); 656 mutex_unlock(&device_mutex); 657 } 658 EXPORT_SYMBOL(tls_register_device); 659 660 void tls_unregister_device(struct tls_device *device) 661 { 662 mutex_lock(&device_mutex); 663 list_del(&device->dev_list); 664 mutex_unlock(&device_mutex); 665 } 666 EXPORT_SYMBOL(tls_unregister_device); 667 668 static struct tcp_ulp_ops tcp_tls_ulp_ops __read_mostly = { 669 .name = "tls", 670 .uid = TCP_ULP_TLS, 671 .user_visible = true, 672 .owner = THIS_MODULE, 673 .init = tls_init, 674 }; 675 676 static int __init tls_register(void) 677 { 678 build_protos(tls_prots[TLSV4], &tcp_prot); 679 680 tls_sw_proto_ops = inet_stream_ops; 681 tls_sw_proto_ops.poll = tls_sw_poll; 682 tls_sw_proto_ops.splice_read = tls_sw_splice_read; 683 684 tcp_register_ulp(&tcp_tls_ulp_ops); 685 686 return 0; 687 } 688 689 static void __exit tls_unregister(void) 690 { 691 tcp_unregister_ulp(&tcp_tls_ulp_ops); 692 } 693 694 module_init(tls_register); 695 module_exit(tls_unregister); 696