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                 rc = copy_to_user(optval, crypto_info, sizeof(*crypto_info));
 277                 goto out;
 278         }
 279
 280         switch (crypto_info->cipher_type) {
 281         case TLS_CIPHER_AES_GCM_128: {
 282                 struct tls12_crypto_info_aes_gcm_128 *
 283                   crypto_info_aes_gcm_128 =
 284                   container_of(crypto_info,
 285                                struct tls12_crypto_info_aes_gcm_128,
 286                                info);
 287
 288                 if (len != sizeof(*crypto_info_aes_gcm_128)) {
 289                         rc = -EINVAL;
 290                         goto out;
 291                 }
 292                 lock_sock(sk);
 293                 memcpy(crypto_info_aes_gcm_128->iv, ctx->iv,
 294                        TLS_CIPHER_AES_GCM_128_IV_SIZE);
 295                 release_sock(sk);
 296                 rc = copy_to_user(optval,
 297                                   crypto_info_aes_gcm_128,
 298                                   sizeof(*crypto_info_aes_gcm_128));
 299                 break;
 300         }
 301         default:
 302                 rc = -EINVAL;
 303         }
 304
 305 out:
 306         return rc;
 307 }
 308
 309 static int do_tls_getsockopt(struct sock *sk, int optname,
 310                              char __user *optval, int __user *optlen)
 311 {
 312         int rc = 0;
 313
 314         switch (optname) {
 315         case TLS_TX:
 316                 rc = do_tls_getsockopt_tx(sk, optval, optlen);
 317                 break;
 318         default:
 319                 rc = -ENOPROTOOPT;
 320                 break;
 321         }
 322         return rc;
 323 }
 324
 325 static int tls_getsockopt(struct sock *sk, int level, int optname,
 326                           char __user *optval, int __user *optlen)
 327 {
 328         struct tls_context *ctx = tls_get_ctx(sk);
 329
 330         if (level != SOL_TLS)
 331                 return ctx->getsockopt(sk, level, optname, optval, optlen);
 332
 333         return do_tls_getsockopt(sk, optname, optval, optlen);
 334 }
 335
 336 static int do_tls_setsockopt_tx(struct sock *sk, char __user *optval,
 337                                 unsigned int optlen)
 338 {
 339         struct tls_crypto_info *crypto_info, tmp_crypto_info;
 340         struct tls_context *ctx = tls_get_ctx(sk);
 341         struct proto *prot = NULL;
 342         int rc = 0;
 343
 344         if (!optval || (optlen < sizeof(*crypto_info))) {
 345                 rc = -EINVAL;
 346                 goto out;
 347         }
 348
 349         rc = copy_from_user(&tmp_crypto_info, optval, sizeof(*crypto_info));
 350         if (rc) {
 351                 rc = -EFAULT;
 352                 goto out;
 353         }
 354
 355         /* check version */
 356         if (tmp_crypto_info.version != TLS_1_2_VERSION) {
 357                 rc = -ENOTSUPP;
 358                 goto out;
 359         }
 360
 361         /* get user crypto info */
 362         crypto_info = &ctx->crypto_send;
 363
 364         /* Currently we don't support set crypto info more than one time */
 365         if (TLS_CRYPTO_INFO_READY(crypto_info))
 366                 goto out;
 367
 368         switch (tmp_crypto_info.cipher_type) {
 369         case TLS_CIPHER_AES_GCM_128: {
 370                 if (optlen != sizeof(struct tls12_crypto_info_aes_gcm_128)) {
 371                         rc = -EINVAL;
 372                         goto out;
 373                 }
 374                 rc = copy_from_user(
 375                   crypto_info,
 376                   optval,
 377                   sizeof(struct tls12_crypto_info_aes_gcm_128));
 378
 379                 if (rc) {
 380                         rc = -EFAULT;
 381                         goto err_crypto_info;
 382                 }
 383                 break;
 384         }
 385         default:
 386                 rc = -EINVAL;
 387                 goto out;
 388         }
 389
 390         ctx->sk_write_space = sk->sk_write_space;
 391         sk->sk_write_space = tls_write_space;
 392
 393         ctx->sk_proto_close = sk->sk_prot->close;
 394
 395         /* currently SW is default, we will have ethtool in future */
 396         rc = tls_set_sw_offload(sk, ctx);
 397         prot = &tls_sw_prot;
 398         if (rc)
 399                 goto err_crypto_info;
 400
 401         sk->sk_prot = prot;
 402         goto out;
 403
 404 err_crypto_info:
 405         memset(crypto_info, 0, sizeof(*crypto_info));
 406 out:
 407         return rc;
 408 }
 409
 410 static int do_tls_setsockopt(struct sock *sk, int optname,
 411                              char __user *optval, unsigned int optlen)
 412 {
 413         int rc = 0;
 414
 415         switch (optname) {
 416         case TLS_TX:
 417                 lock_sock(sk);
 418                 rc = do_tls_setsockopt_tx(sk, optval, optlen);
 419                 release_sock(sk);
 420                 break;
 421         default:
 422                 rc = -ENOPROTOOPT;
 423                 break;
 424         }
 425         return rc;
 426 }
 427
 428 static int tls_setsockopt(struct sock *sk, int level, int optname,
 429                           char __user *optval, unsigned int optlen)
 430 {
 431         struct tls_context *ctx = tls_get_ctx(sk);
 432
 433         if (level != SOL_TLS)
 434                 return ctx->setsockopt(sk, level, optname, optval, optlen);
 435
 436         return do_tls_setsockopt(sk, optname, optval, optlen);
 437 }
 438
 439 static int tls_init(struct sock *sk)
 440 {
 441         struct inet_connection_sock *icsk = inet_csk(sk);
 442         struct tls_context *ctx;
 443         int rc = 0;
 444
 445         /* allocate tls context */
 446         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
 447         if (!ctx) {
 448                 rc = -ENOMEM;
 449                 goto out;
 450         }
 451         icsk->icsk_ulp_data = ctx;
 452         ctx->setsockopt = sk->sk_prot->setsockopt;
 453         ctx->getsockopt = sk->sk_prot->getsockopt;
 454         sk->sk_prot = &tls_base_prot;
 455 out:
 456         return rc;
 457 }
 458
 459 static struct tcp_ulp_ops tcp_tls_ulp_ops __read_mostly = {
 460         .name                   = "tls",
 461         .owner                  = THIS_MODULE,
 462         .init                   = tls_init,
 463 };
 464
 465 static int __init tls_register(void)
 466 {
 467         tls_base_prot                   = tcp_prot;
 468         tls_base_prot.setsockopt        = tls_setsockopt;
 469         tls_base_prot.getsockopt        = tls_getsockopt;
 470
 471         tls_sw_prot                     = tls_base_prot;
 472         tls_sw_prot.sendmsg             = tls_sw_sendmsg;
 473         tls_sw_prot.sendpage            = tls_sw_sendpage;
 474         tls_sw_prot.close               = tls_sk_proto_close;
 475
 476         tcp_register_ulp(&tcp_tls_ulp_ops);
 477
 478         return 0;
 479 }
 480
 481 static void __exit tls_unregister(void)
 482 {
 483         tcp_unregister_ulp(&tcp_tls_ulp_ops);
 484 }
 485
 486 module_init(tls_register);
 487 module_exit(tls_unregister);