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/crypto.h>
  40 #include <linux/socket.h>
  41 #include <linux/tcp.h>
  42 #include <net/tcp.h>
  43
  44 #include <uapi/linux/tls.h>
  45
  46
  47 /* Maximum data size carried in a TLS record */
  48 #define TLS_MAX_PAYLOAD_SIZE            ((size_t)1 << 14)
  49
  50 #define TLS_HEADER_SIZE                 5
  51 #define TLS_NONCE_OFFSET                TLS_HEADER_SIZE
  52
  53 #define TLS_CRYPTO_INFO_READY(info)     ((info)->cipher_type)
  54
  55 #define TLS_RECORD_TYPE_DATA            0x17
  56
  57 #define TLS_AAD_SPACE_SIZE              13
  58
  59 struct tls_sw_context {
  60         struct crypto_aead *aead_send;
  61         struct crypto_wait async_wait;
  62
  63         /* Sending context */
  64         char aad_space[TLS_AAD_SPACE_SIZE];
  65
  66         unsigned int sg_plaintext_size;
  67         int sg_plaintext_num_elem;
  68         struct scatterlist sg_plaintext_data[MAX_SKB_FRAGS];
  69
  70         unsigned int sg_encrypted_size;
  71         int sg_encrypted_num_elem;
  72         struct scatterlist sg_encrypted_data[MAX_SKB_FRAGS];
  73
  74         /* AAD | sg_plaintext_data | sg_tag */
  75         struct scatterlist sg_aead_in[2];
  76         /* AAD | sg_encrypted_data (data contain overhead for hdr&iv&tag) */
  77         struct scatterlist sg_aead_out[2];
  78 };
  79
  80 enum {
  81         TLS_PENDING_CLOSED_RECORD
  82 };
  83
  84 struct cipher_context {
  85         u16 prepend_size;
  86         u16 tag_size;
  87         u16 overhead_size;
  88         u16 iv_size;
  89         char *iv;
  90         u16 rec_seq_size;
  91         char *rec_seq;
  92 };
  93
  94 struct tls_context {
  95         union {
  96                 struct tls_crypto_info crypto_send;
  97                 struct tls12_crypto_info_aes_gcm_128 crypto_send_aes_gcm_128;
  98         };
  99
 100         void *priv_ctx;
 101
 102         u8 conf:2;
 103
 104         struct cipher_context tx;
 105
 106         struct scatterlist *partially_sent_record;
 107         u16 partially_sent_offset;
 108         unsigned long flags;
 109
 110         u16 pending_open_record_frags;
 111         int (*push_pending_record)(struct sock *sk, int flags);
 112
 113         void (*sk_write_space)(struct sock *sk);
 114         void (*sk_proto_close)(struct sock *sk, long timeout);
 115
 116         int  (*setsockopt)(struct sock *sk, int level,
 117                            int optname, char __user *optval,
 118                            unsigned int optlen);
 119         int  (*getsockopt)(struct sock *sk, int level,
 120                            int optname, char __user *optval,
 121                            int __user *optlen);
 122 };
 123
 124 int wait_on_pending_writer(struct sock *sk, long *timeo);
 125 int tls_sk_query(struct sock *sk, int optname, char __user *optval,
 126                 int __user *optlen);
 127 int tls_sk_attach(struct sock *sk, int optname, char __user *optval,
 128                   unsigned int optlen);
 129
 130
 131 int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx);
 132 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
 133 int tls_sw_sendpage(struct sock *sk, struct page *page,
 134                     int offset, size_t size, int flags);
 135 void tls_sw_close(struct sock *sk, long timeout);
 136 void tls_sw_free_tx_resources(struct sock *sk);
 137
 138 void tls_sk_destruct(struct sock *sk, struct tls_context *ctx);
 139 void tls_icsk_clean_acked(struct sock *sk);
 140
 141 int tls_push_sg(struct sock *sk, struct tls_context *ctx,
 142                 struct scatterlist *sg, u16 first_offset,
 143                 int flags);
 144 int tls_push_pending_closed_record(struct sock *sk, struct tls_context *ctx,
 145                                    int flags, long *timeo);
 146
 147 static inline bool tls_is_pending_closed_record(struct tls_context *ctx)
 148 {
 149         return test_bit(TLS_PENDING_CLOSED_RECORD, &ctx->flags);
 150 }
 151
 152 static inline int tls_complete_pending_work(struct sock *sk,
 153                                             struct tls_context *ctx,
 154                                             int flags, long *timeo)
 155 {
 156         int rc = 0;
 157
 158         if (unlikely(sk->sk_write_pending))
 159                 rc = wait_on_pending_writer(sk, timeo);
 160
 161         if (!rc && tls_is_pending_closed_record(ctx))
 162                 rc = tls_push_pending_closed_record(sk, ctx, flags, timeo);
 163
 164         return rc;
 165 }
 166
 167 static inline bool tls_is_partially_sent_record(struct tls_context *ctx)
 168 {
 169         return !!ctx->partially_sent_record;
 170 }
 171
 172 static inline bool tls_is_pending_open_record(struct tls_context *tls_ctx)
 173 {
 174         return tls_ctx->pending_open_record_frags;
 175 }
 176
 177 static inline void tls_err_abort(struct sock *sk, int err)
 178 {
 179         sk->sk_err = err;
 180         sk->sk_error_report(sk);
 181 }
 182
 183 static inline bool tls_bigint_increment(unsigned char *seq, int len)
 184 {
 185         int i;
 186
 187         for (i = len - 1; i >= 0; i--) {
 188                 ++seq[i];
 189                 if (seq[i] != 0)
 190                         break;
 191         }
 192
 193         return (i == -1);
 194 }
 195
 196 static inline void tls_advance_record_sn(struct sock *sk,
 197                                          struct cipher_context *ctx)
 198 {
 199         if (tls_bigint_increment(ctx->rec_seq, ctx->rec_seq_size))
 200                 tls_err_abort(sk, EBADMSG);
 201         tls_bigint_increment(ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
 202                              ctx->iv_size);
 203 }
 204
 205 static inline void tls_fill_prepend(struct tls_context *ctx,
 206                              char *buf,
 207                              size_t plaintext_len,
 208                              unsigned char record_type)
 209 {
 210         size_t pkt_len, iv_size = ctx->tx.iv_size;
 211
 212         pkt_len = plaintext_len + iv_size + ctx->tx.tag_size;
 213
 214         /* we cover nonce explicit here as well, so buf should be of
 215          * size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
 216          */
 217         buf[0] = record_type;
 218         buf[1] = TLS_VERSION_MINOR(ctx->crypto_send.version);
 219         buf[2] = TLS_VERSION_MAJOR(ctx->crypto_send.version);
 220         /* we can use IV for nonce explicit according to spec */
 221         buf[3] = pkt_len >> 8;
 222         buf[4] = pkt_len & 0xFF;
 223         memcpy(buf + TLS_NONCE_OFFSET,
 224                ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv_size);
 225 }
 226
 227 static inline void tls_make_aad(char *buf,
 228                                 size_t size,
 229                                 char *record_sequence,
 230                                 int record_sequence_size,
 231                                 unsigned char record_type)
 232 {
 233         memcpy(buf, record_sequence, record_sequence_size);
 234
 235         buf[8] = record_type;
 236         buf[9] = TLS_1_2_VERSION_MAJOR;
 237         buf[10] = TLS_1_2_VERSION_MINOR;
 238         buf[11] = size >> 8;
 239         buf[12] = size & 0xFF;
 240 }
 241
 242 static inline struct tls_context *tls_get_ctx(const struct sock *sk)
 243 {
 244         struct inet_connection_sock *icsk = inet_csk(sk);
 245
 246         return icsk->icsk_ulp_data;
 247 }
 248
 249 static inline struct tls_sw_context *tls_sw_ctx(
 250                 const struct tls_context *tls_ctx)
 251 {
 252         return (struct tls_sw_context *)tls_ctx->priv_ctx;
 253 }
 254
 255 static inline struct tls_offload_context *tls_offload_ctx(
 256                 const struct tls_context *tls_ctx)
 257 {
 258         return (struct tls_offload_context *)tls_ctx->priv_ctx;
 259 }
 260
 261 int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
 262                       unsigned char *record_type);
 263
 264 #endif /* _TLS_OFFLOAD_H */