net/tls/tls_main.c

   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
  42 #include <net/tls.h>
  43
  44 MODULE_AUTHOR("Mellanox Technologies");
  45 MODULE_DESCRIPTION("Transport Layer Security Support");
  46 MODULE_LICENSE("Dual BSD/GPL");
  47
  48 enum {
  49         TLSV4,
  50         TLSV6,
  51         TLS_NUM_PROTS,
  52 };
  53
  54 enum {
  55         TLS_BASE_TX,
  56         TLS_SW_TX,
  57         TLS_NUM_CONFIG,
  58 };
  59
  60 static struct proto *saved_tcpv6_prot;
  61 static DEFINE_MUTEX(tcpv6_prot_mutex);
  62 static struct proto tls_prots[TLS_NUM_PROTS][TLS_NUM_CONFIG];
  63
  64 static inline void update_sk_prot(struct sock *sk, struct tls_context *ctx)
  65 {
  66         int ip_ver = sk->sk_family == AF_INET6 ? TLSV6 : TLSV4;
  67
  68         sk->sk_prot = &tls_prots[ip_ver][ctx->tx_conf];
  69 }
  70
  71 int wait_on_pending_writer(struct sock *sk, long *timeo)
  72 {
  73         int rc = 0;
  74         DEFINE_WAIT_FUNC(wait, woken_wake_function);
  75
  76         add_wait_queue(sk_sleep(sk), &wait);
  77         while (1) {
  78                 if (!*timeo) {
  79                         rc = -EAGAIN;
  80                         break;
  81                 }
  82
  83                 if (signal_pending(current)) {
  84                         rc = sock_intr_errno(*timeo);
  85                         break;
  86                 }
  87
  88                 if (sk_wait_event(sk, timeo, !sk->sk_write_pending, &wait))
  89                         break;
  90         }
  91         remove_wait_queue(sk_sleep(sk), &wait);
  92         return rc;
  93 }
  94
  95 int tls_push_sg(struct sock *sk,
  96                 struct tls_context *ctx,
  97                 struct scatterlist *sg,
  98                 u16 first_offset,
  99                 int flags)
 100 {
 101         int sendpage_flags = flags | MSG_SENDPAGE_NOTLAST;
 102         int ret = 0;
 103         struct page *p;
 104         size_t size;
 105         int offset = first_offset;
 106
 107         size = sg->length - offset;
 108         offset += sg->offset;
 109
 110         while (1) {
 111                 if (sg_is_last(sg))
 112                         sendpage_flags = flags;
 113
 114                 /* is sending application-limited? */
 115                 tcp_rate_check_app_limited(sk);
 116                 p = sg_page(sg);
 117 retry:
 118                 ret = do_tcp_sendpages(sk, p, offset, size, sendpage_flags);
 119
 120                 if (ret != size) {
 121                         if (ret > 0) {
 122                                 offset += ret;
 123                                 size -= ret;
 124                                 goto retry;
 125                         }
 126
 127                         offset -= sg->offset;
 128                         ctx->partially_sent_offset = offset;
 129                         ctx->partially_sent_record = (void *)sg;
 130                         return ret;
 131                 }
 132
 133                 put_page(p);
 134                 sk_mem_uncharge(sk, sg->length);
 135                 sg = sg_next(sg);
 136                 if (!sg)
 137                         break;
 138
 139                 offset = sg->offset;
 140                 size = sg->length;
 141         }
 142
 143         clear_bit(TLS_PENDING_CLOSED_RECORD, &ctx->flags);
 144
 145         return 0;
 146 }
 147
 148 static int tls_handle_open_record(struct sock *sk, int flags)
 149 {
 150         struct tls_context *ctx = tls_get_ctx(sk);
 151
 152         if (tls_is_pending_open_record(ctx))
 153                 return ctx->push_pending_record(sk, flags);
 154
 155         return 0;
 156 }
 157
 158 int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
 159                       unsigned char *record_type)
 160 {
 161         struct cmsghdr *cmsg;
 162         int rc = -EINVAL;
 163
 164         for_each_cmsghdr(cmsg, msg) {
 165                 if (!CMSG_OK(msg, cmsg))
 166                         return -EINVAL;
 167                 if (cmsg->cmsg_level != SOL_TLS)
 168                         continue;
 169
 170                 switch (cmsg->cmsg_type) {
 171                 case TLS_SET_RECORD_TYPE:
 172                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(*record_type)))
 173                                 return -EINVAL;
 174
 175                         if (msg->msg_flags & MSG_MORE)
 176                                 return -EINVAL;
 177
 178                         rc = tls_handle_open_record(sk, msg->msg_flags);
 179                         if (rc)
 180                                 return rc;
 181
 182                         *record_type = *(unsigned char *)CMSG_DATA(cmsg);
 183                         rc = 0;
 184                         break;
 185                 default:
 186                         return -EINVAL;
 187                 }
 188         }
 189
 190         return rc;
 191 }
 192
 193 int tls_push_pending_closed_record(struct sock *sk, struct tls_context *ctx,
 194                                    int flags, long *timeo)
 195 {
 196         struct scatterlist *sg;
 197         u16 offset;
 198
 199         if (!tls_is_partially_sent_record(ctx))
 200                 return ctx->push_pending_record(sk, flags);
 201
 202         sg = ctx->partially_sent_record;
 203         offset = ctx->partially_sent_offset;
 204
 205         ctx->partially_sent_record = NULL;
 206         return tls_push_sg(sk, ctx, sg, offset, flags);
 207 }
 208
 209 static void tls_write_space(struct sock *sk)
 210 {
 211         struct tls_context *ctx = tls_get_ctx(sk);
 212
 213         if (!sk->sk_write_pending && tls_is_pending_closed_record(ctx)) {
 214                 gfp_t sk_allocation = sk->sk_allocation;
 215                 int rc;
 216                 long timeo = 0;
 217
 218                 sk->sk_allocation = GFP_ATOMIC;
 219                 rc = tls_push_pending_closed_record(sk, ctx,
 220                                                     MSG_DONTWAIT |
 221                                                     MSG_NOSIGNAL,
 222                                                     &timeo);
 223                 sk->sk_allocation = sk_allocation;
 224
 225                 if (rc < 0)
 226                         return;
 227         }
 228
 229         ctx->sk_write_space(sk);
 230 }
 231
 232 static void tls_sk_proto_close(struct sock *sk, long timeout)
 233 {
 234         struct tls_context *ctx = tls_get_ctx(sk);
 235         long timeo = sock_sndtimeo(sk, 0);
 236         void (*sk_proto_close)(struct sock *sk, long timeout);
 237
 238         lock_sock(sk);
 239         sk_proto_close = ctx->sk_proto_close;
 240
 241         if (ctx->tx_conf == TLS_BASE_TX) {
 242                 kfree(ctx);
 243                 goto skip_tx_cleanup;
 244         }
 245
 246         if (!tls_complete_pending_work(sk, ctx, 0, &timeo))
 247                 tls_handle_open_record(sk, 0);
 248
 249         if (ctx->partially_sent_record) {
 250                 struct scatterlist *sg = ctx->partially_sent_record;
 251
 252                 while (1) {
 253                         put_page(sg_page(sg));
 254                         sk_mem_uncharge(sk, sg->length);
 255
 256                         if (sg_is_last(sg))
 257                                 break;
 258                         sg++;
 259                 }
 260         }
 261
 262         kfree(ctx->rec_seq);
 263         kfree(ctx->iv);
 264
 265         if (ctx->tx_conf == TLS_SW_TX)
 266                 tls_sw_free_tx_resources(sk);
 267
 268 skip_tx_cleanup:
 269         release_sock(sk);
 270         sk_proto_close(sk, timeout);
 271 }
 272
 273 static int do_tls_getsockopt_tx(struct sock *sk, char __user *optval,
 274                                 int __user *optlen)
 275 {
 276         int rc = 0;
 277         struct tls_context *ctx = tls_get_ctx(sk);
 278         struct tls_crypto_info *crypto_info;
 279         int len;
 280
 281         if (get_user(len, optlen))
 282                 return -EFAULT;
 283
 284         if (!optval || (len < sizeof(*crypto_info))) {
 285                 rc = -EINVAL;
 286                 goto out;
 287         }
 288
 289         if (!ctx) {
 290                 rc = -EBUSY;
 291                 goto out;
 292         }
 293
 294         /* get user crypto info */
 295         crypto_info = &ctx->crypto_send;
 296
 297         if (!TLS_CRYPTO_INFO_READY(crypto_info)) {
 298                 rc = -EBUSY;
 299                 goto out;
 300         }
 301
 302         if (len == sizeof(*crypto_info)) {
 303                 if (copy_to_user(optval, crypto_info, sizeof(*crypto_info)))
 304                         rc = -EFAULT;
 305                 goto out;
 306         }
 307
 308         switch (crypto_info->cipher_type) {
 309         case TLS_CIPHER_AES_GCM_128: {
 310                 struct tls12_crypto_info_aes_gcm_128 *
 311                   crypto_info_aes_gcm_128 =
 312                   container_of(crypto_info,
 313                                struct tls12_crypto_info_aes_gcm_128,
 314                                info);
 315
 316                 if (len != sizeof(*crypto_info_aes_gcm_128)) {
 317                         rc = -EINVAL;
 318                         goto out;
 319                 }
 320                 lock_sock(sk);
 321                 memcpy(crypto_info_aes_gcm_128->iv,
 322                        ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
 323                        TLS_CIPHER_AES_GCM_128_IV_SIZE);
 324                 memcpy(crypto_info_aes_gcm_128->rec_seq, ctx->rec_seq,
 325                        TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE);
 326                 release_sock(sk);
 327                 if (copy_to_user(optval,
 328                                  crypto_info_aes_gcm_128,
 329                                  sizeof(*crypto_info_aes_gcm_128)))
 330                         rc = -EFAULT;
 331                 break;
 332         }
 333         default:
 334                 rc = -EINVAL;
 335         }
 336
 337 out:
 338         return rc;
 339 }
 340
 341 static int do_tls_getsockopt(struct sock *sk, int optname,
 342                              char __user *optval, int __user *optlen)
 343 {
 344         int rc = 0;
 345
 346         switch (optname) {
 347         case TLS_TX:
 348                 rc = do_tls_getsockopt_tx(sk, optval, optlen);
 349                 break;
 350         default:
 351                 rc = -ENOPROTOOPT;
 352                 break;
 353         }
 354         return rc;
 355 }
 356
 357 static int tls_getsockopt(struct sock *sk, int level, int optname,
 358                           char __user *optval, int __user *optlen)
 359 {
 360         struct tls_context *ctx = tls_get_ctx(sk);
 361
 362         if (level != SOL_TLS)
 363                 return ctx->getsockopt(sk, level, optname, optval, optlen);
 364
 365         return do_tls_getsockopt(sk, optname, optval, optlen);
 366 }
 367
 368 static int do_tls_setsockopt_tx(struct sock *sk, char __user *optval,
 369                                 unsigned int optlen)
 370 {
 371         struct tls_crypto_info *crypto_info;
 372         struct tls_context *ctx = tls_get_ctx(sk);
 373         int rc = 0;
 374         int tx_conf;
 375
 376         if (!optval || (optlen < sizeof(*crypto_info))) {
 377                 rc = -EINVAL;
 378                 goto out;
 379         }
 380
 381         crypto_info = &ctx->crypto_send;
 382         /* Currently we don't support set crypto info more than one time */
 383         if (TLS_CRYPTO_INFO_READY(crypto_info)) {
 384                 rc = -EBUSY;
 385                 goto out;
 386         }
 387
 388         rc = copy_from_user(crypto_info, optval, sizeof(*crypto_info));
 389         if (rc) {
 390                 rc = -EFAULT;
 391                 goto err_crypto_info;
 392         }
 393
 394         /* check version */
 395         if (crypto_info->version != TLS_1_2_VERSION) {
 396                 rc = -ENOTSUPP;
 397                 goto err_crypto_info;
 398         }
 399
 400         switch (crypto_info->cipher_type) {
 401         case TLS_CIPHER_AES_GCM_128: {
 402                 if (optlen != sizeof(struct tls12_crypto_info_aes_gcm_128)) {
 403                         rc = -EINVAL;
 404                         goto err_crypto_info;
 405                 }
 406                 rc = copy_from_user(crypto_info + 1, optval + sizeof(*crypto_info),
 407                                     optlen - sizeof(*crypto_info));
 408                 if (rc) {
 409                         rc = -EFAULT;
 410                         goto err_crypto_info;
 411                 }
 412                 break;
 413         }
 414         default:
 415                 rc = -EINVAL;
 416                 goto err_crypto_info;
 417         }
 418
 419         /* currently SW is default, we will have ethtool in future */
 420         rc = tls_set_sw_offload(sk, ctx);
 421         tx_conf = TLS_SW_TX;
 422         if (rc)
 423                 goto err_crypto_info;
 424
 425         ctx->tx_conf = tx_conf;
 426         update_sk_prot(sk, ctx);
 427         ctx->sk_write_space = sk->sk_write_space;
 428         sk->sk_write_space = tls_write_space;
 429         goto out;
 430
 431 err_crypto_info:
 432         memset(crypto_info, 0, sizeof(*crypto_info));
 433 out:
 434         return rc;
 435 }
 436
 437 static int do_tls_setsockopt(struct sock *sk, int optname,
 438                              char __user *optval, unsigned int optlen)
 439 {
 440         int rc = 0;
 441
 442         switch (optname) {
 443         case TLS_TX:
 444                 lock_sock(sk);
 445                 rc = do_tls_setsockopt_tx(sk, optval, optlen);
 446                 release_sock(sk);
 447                 break;
 448         default:
 449                 rc = -ENOPROTOOPT;
 450                 break;
 451         }
 452         return rc;
 453 }
 454
 455 static int tls_setsockopt(struct sock *sk, int level, int optname,
 456                           char __user *optval, unsigned int optlen)
 457 {
 458         struct tls_context *ctx = tls_get_ctx(sk);
 459
 460         if (level != SOL_TLS)
 461                 return ctx->setsockopt(sk, level, optname, optval, optlen);
 462
 463         return do_tls_setsockopt(sk, optname, optval, optlen);
 464 }
 465
 466 static void build_protos(struct proto *prot, struct proto *base)
 467 {
 468         prot[TLS_BASE_TX] = *base;
 469         prot[TLS_BASE_TX].setsockopt    = tls_setsockopt;
 470         prot[TLS_BASE_TX].getsockopt    = tls_getsockopt;
 471         prot[TLS_BASE_TX].close         = tls_sk_proto_close;
 472
 473         prot[TLS_SW_TX] = prot[TLS_BASE_TX];
 474         prot[TLS_SW_TX].sendmsg         = tls_sw_sendmsg;
 475         prot[TLS_SW_TX].sendpage        = tls_sw_sendpage;
 476 }
 477
 478 static int tls_init(struct sock *sk)
 479 {
 480         int ip_ver = sk->sk_family == AF_INET6 ? TLSV6 : TLSV4;
 481         struct inet_connection_sock *icsk = inet_csk(sk);
 482         struct tls_context *ctx;
 483         int rc = 0;
 484
 485         /* The TLS ulp is currently supported only for TCP sockets
 486          * in ESTABLISHED state.
 487          * Supporting sockets in LISTEN state will require us
 488          * to modify the accept implementation to clone rather then
 489          * share the ulp context.
 490          */
 491         if (sk->sk_state != TCP_ESTABLISHED)
 492                 return -ENOTSUPP;
 493
 494         /* allocate tls context */
 495         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
 496         if (!ctx) {
 497                 rc = -ENOMEM;
 498                 goto out;
 499         }
 500         icsk->icsk_ulp_data = ctx;
 501         ctx->setsockopt = sk->sk_prot->setsockopt;
 502         ctx->getsockopt = sk->sk_prot->getsockopt;
 503         ctx->sk_proto_close = sk->sk_prot->close;
 504
 505         /* Build IPv6 TLS whenever the address of tcpv6_prot changes */
 506         if (ip_ver == TLSV6 &&
 507             unlikely(sk->sk_prot != smp_load_acquire(&saved_tcpv6_prot))) {
 508                 mutex_lock(&tcpv6_prot_mutex);
 509                 if (likely(sk->sk_prot != saved_tcpv6_prot)) {
 510                         build_protos(tls_prots[TLSV6], sk->sk_prot);
 511                         smp_store_release(&saved_tcpv6_prot, sk->sk_prot);
 512                 }
 513                 mutex_unlock(&tcpv6_prot_mutex);
 514         }
 515
 516         ctx->tx_conf = TLS_BASE_TX;
 517         update_sk_prot(sk, ctx);
 518 out:
 519         return rc;
 520 }
 521
 522 static struct tcp_ulp_ops tcp_tls_ulp_ops __read_mostly = {
 523         .name                   = "tls",
 524         .uid                    = TCP_ULP_TLS,
 525         .user_visible           = true,
 526         .owner                  = THIS_MODULE,
 527         .init                   = tls_init,
 528 };
 529
 530 static int __init tls_register(void)
 531 {
 532         build_protos(tls_prots[TLSV4], &tcp_prot);
 533
 534         tcp_register_ulp(&tcp_tls_ulp_ops);
 535
 536         return 0;
 537 }
 538
 539 static void __exit tls_unregister(void)
 540 {
 541         tcp_unregister_ulp(&tcp_tls_ulp_ops);
 542 }
 543
 544 module_init(tls_register);
 545 module_exit(tls_unregister);