include/net/tls.h

   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 #ifndef _TLS_OFFLOAD_H
  35 #define _TLS_OFFLOAD_H
  36
  37 #include <linux/types.h>
  38 #include <asm/byteorder.h>
  39 #include <linux/socket.h>
  40 #include <linux/tcp.h>
  41 #include <net/tcp.h>
  42
  43 #include <uapi/linux/tls.h>
  44
  45
  46 /* Maximum data size carried in a TLS record */
  47 #define TLS_MAX_PAYLOAD_SIZE            ((size_t)1 << 14)
  48
  49 #define TLS_HEADER_SIZE                 5
  50 #define TLS_NONCE_OFFSET                TLS_HEADER_SIZE
  51
  52 #define TLS_CRYPTO_INFO_READY(info)     ((info)->cipher_type)
  53
  54 #define TLS_RECORD_TYPE_DATA            0x17
  55
  56 #define TLS_AAD_SPACE_SIZE              13
  57
  58 struct tls_sw_context {
  59         struct crypto_aead *aead_send;
  60
  61         /* Sending context */
  62         char aad_space[TLS_AAD_SPACE_SIZE];
  63
  64         unsigned int sg_plaintext_size;
  65         int sg_plaintext_num_elem;
  66         struct scatterlist sg_plaintext_data[MAX_SKB_FRAGS];
  67
  68         unsigned int sg_encrypted_size;
  69         int sg_encrypted_num_elem;
  70         struct scatterlist sg_encrypted_data[MAX_SKB_FRAGS];
  71
  72         /* AAD | sg_plaintext_data | sg_tag */
  73         struct scatterlist sg_aead_in[2];
  74         /* AAD | sg_encrypted_data (data contain overhead for hdr&iv&tag) */
  75         struct scatterlist sg_aead_out[2];
  76 };
  77
  78 enum {
  79         TLS_PENDING_CLOSED_RECORD
  80 };
  81
  82 struct tls_context {
  83         union {
  84                 struct tls_crypto_info crypto_send;
  85                 struct tls12_crypto_info_aes_gcm_128 crypto_send_aes_gcm_128;
  86         };
  87
  88         void *priv_ctx;
  89
  90         u8 tx_conf:2;
  91
  92         u16 prepend_size;
  93         u16 tag_size;
  94         u16 overhead_size;
  95         u16 iv_size;
  96         char *iv;
  97         u16 rec_seq_size;
  98         char *rec_seq;
  99
 100         struct scatterlist *partially_sent_record;
 101         u16 partially_sent_offset;
 102         unsigned long flags;
 103
 104         u16 pending_open_record_frags;
 105         int (*push_pending_record)(struct sock *sk, int flags);
 106
 107         void (*sk_write_space)(struct sock *sk);
 108         void (*sk_proto_close)(struct sock *sk, long timeout);
 109
 110         int  (*setsockopt)(struct sock *sk, int level,
 111                            int optname, char __user *optval,
 112                            unsigned int optlen);
 113         int  (*getsockopt)(struct sock *sk, int level,
 114                            int optname, char __user *optval,
 115                            int __user *optlen);
 116 };
 117
 118 int wait_on_pending_writer(struct sock *sk, long *timeo);
 119 int tls_sk_query(struct sock *sk, int optname, char __user *optval,
 120                 int __user *optlen);
 121 int tls_sk_attach(struct sock *sk, int optname, char __user *optval,
 122                   unsigned int optlen);
 123
 124
 125 int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx);
 126 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
 127 int tls_sw_sendpage(struct sock *sk, struct page *page,
 128                     int offset, size_t size, int flags);
 129 void tls_sw_close(struct sock *sk, long timeout);
 130 void tls_sw_free_tx_resources(struct sock *sk);
 131
 132 void tls_sk_destruct(struct sock *sk, struct tls_context *ctx);
 133 void tls_icsk_clean_acked(struct sock *sk);
 134
 135 int tls_push_sg(struct sock *sk, struct tls_context *ctx,
 136                 struct scatterlist *sg, u16 first_offset,
 137                 int flags);
 138 int tls_push_pending_closed_record(struct sock *sk, struct tls_context *ctx,
 139                                    int flags, long *timeo);
 140
 141 static inline bool tls_is_pending_closed_record(struct tls_context *ctx)
 142 {
 143         return test_bit(TLS_PENDING_CLOSED_RECORD, &ctx->flags);
 144 }
 145
 146 static inline int tls_complete_pending_work(struct sock *sk,
 147                                             struct tls_context *ctx,
 148                                             int flags, long *timeo)
 149 {
 150         int rc = 0;
 151
 152         if (unlikely(sk->sk_write_pending))
 153                 rc = wait_on_pending_writer(sk, timeo);
 154
 155         if (!rc && tls_is_pending_closed_record(ctx))
 156                 rc = tls_push_pending_closed_record(sk, ctx, flags, timeo);
 157
 158         return rc;
 159 }
 160
 161 static inline bool tls_is_partially_sent_record(struct tls_context *ctx)
 162 {
 163         return !!ctx->partially_sent_record;
 164 }
 165
 166 static inline bool tls_is_pending_open_record(struct tls_context *tls_ctx)
 167 {
 168         return tls_ctx->pending_open_record_frags;
 169 }
 170
 171 static inline void tls_err_abort(struct sock *sk)
 172 {
 173         sk->sk_err = EBADMSG;
 174         sk->sk_error_report(sk);
 175 }
 176
 177 static inline bool tls_bigint_increment(unsigned char *seq, int len)
 178 {
 179         int i;
 180
 181         for (i = len - 1; i >= 0; i--) {
 182                 ++seq[i];
 183                 if (seq[i] != 0)
 184                         break;
 185         }
 186
 187         return (i == -1);
 188 }
 189
 190 static inline void tls_advance_record_sn(struct sock *sk,
 191                                          struct tls_context *ctx)
 192 {
 193         if (tls_bigint_increment(ctx->rec_seq, ctx->rec_seq_size))
 194                 tls_err_abort(sk);
 195         tls_bigint_increment(ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
 196                              ctx->iv_size);
 197 }
 198
 199 static inline void tls_fill_prepend(struct tls_context *ctx,
 200                              char *buf,
 201                              size_t plaintext_len,
 202                              unsigned char record_type)
 203 {
 204         size_t pkt_len, iv_size = ctx->iv_size;
 205
 206         pkt_len = plaintext_len + iv_size + ctx->tag_size;
 207
 208         /* we cover nonce explicit here as well, so buf should be of
 209          * size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
 210          */
 211         buf[0] = record_type;
 212         buf[1] = TLS_VERSION_MINOR(ctx->crypto_send.version);
 213         buf[2] = TLS_VERSION_MAJOR(ctx->crypto_send.version);
 214         /* we can use IV for nonce explicit according to spec */
 215         buf[3] = pkt_len >> 8;
 216         buf[4] = pkt_len & 0xFF;
 217         memcpy(buf + TLS_NONCE_OFFSET,
 218                ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv_size);
 219 }
 220
 221 static inline void tls_make_aad(char *buf,
 222                                 size_t size,
 223                                 char *record_sequence,
 224                                 int record_sequence_size,
 225                                 unsigned char record_type)
 226 {
 227         memcpy(buf, record_sequence, record_sequence_size);
 228
 229         buf[8] = record_type;
 230         buf[9] = TLS_1_2_VERSION_MAJOR;
 231         buf[10] = TLS_1_2_VERSION_MINOR;
 232         buf[11] = size >> 8;
 233         buf[12] = size & 0xFF;
 234 }
 235
 236 static inline struct tls_context *tls_get_ctx(const struct sock *sk)
 237 {
 238         struct inet_connection_sock *icsk = inet_csk(sk);
 239
 240         return icsk->icsk_ulp_data;
 241 }
 242
 243 static inline struct tls_sw_context *tls_sw_ctx(
 244                 const struct tls_context *tls_ctx)
 245 {
 246         return (struct tls_sw_context *)tls_ctx->priv_ctx;
 247 }
 248
 249 static inline struct tls_offload_context *tls_offload_ctx(
 250                 const struct tls_context *tls_ctx)
 251 {
 252         return (struct tls_offload_context *)tls_ctx->priv_ctx;
 253 }
 254
 255 int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
 256                       unsigned char *record_type);
 257
 258 #endif /* _TLS_OFFLOAD_H */