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