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