tls.h
/*
* Copyright (c) 2016-2017, Mellanox Technologies. All rights reserved.
* Copyright (c) 2016-2017, Dave Watson <davejwatson@fb.com>. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#ifndef _TLS_OFFLOAD_H
#define _TLS_OFFLOAD_H
#include <linux/types.h>
#include <asm/byteorder.h>
#include <linux/crypto.h>
#include <linux/socket.h>
#include <linux/tcp.h>
#include <linux/mutex.h>
#include <linux/netdevice.h>
#include <linux/rcupdate.h>
#include <net/net_namespace.h>
#include <net/tcp.h>
#include <net/strparser.h>
#include <crypto/aead.h>
#include <uapi/linux/tls.h>
struct tls_rec;
struct tls_cipher_size_desc {
unsigned int iv;
unsigned int key;
unsigned int salt;
unsigned int tag;
unsigned int rec_seq;
};
extern const struct tls_cipher_size_desc tls_cipher_size_desc[];
/* Maximum data size carried in a TLS record */
#define TLS_MAX_PAYLOAD_SIZE ((size_t)1 << 14)
#define TLS_HEADER_SIZE 5
#define TLS_NONCE_OFFSET TLS_HEADER_SIZE
#define TLS_CRYPTO_INFO_READY(info) ((info)->cipher_type)
#define TLS_RECORD_TYPE_DATA 0x17
#define TLS_AAD_SPACE_SIZE 13
#define MAX_IV_SIZE 16
#define TLS_TAG_SIZE 16
#define TLS_MAX_REC_SEQ_SIZE 8
#define TLS_MAX_AAD_SIZE TLS_AAD_SPACE_SIZE
/* For CCM mode, the full 16-bytes of IV is made of '4' fields of given sizes.
*
* IV[16] = b0[1] || implicit nonce[4] || explicit nonce[8] || length[3]
*
* The field 'length' is encoded in field 'b0' as '(length width - 1)'.
* Hence b0 contains (3 - 1) = 2.
*/
#define TLS_AES_CCM_IV_B0_BYTE 2
#define TLS_SM4_CCM_IV_B0_BYTE 2
enum {
TLS_BASE,
TLS_SW,
TLS_HW,
TLS_HW_RECORD,
TLS_NUM_CONFIG,
};
struct tx_work {
struct delayed_work work;
struct sock *sk;
};
struct tls_sw_context_tx {
struct crypto_aead *aead_send;
struct crypto_wait async_wait;
struct tx_work tx_work;
struct tls_rec *open_rec;
struct list_head tx_list;
atomic_t encrypt_pending;
/* protect crypto_wait with encrypt_pending */
spinlock_t encrypt_compl_lock;
int async_notify;
u8 async_capable:1;
#define BIT_TX_SCHEDULED 0
#define BIT_TX_CLOSING 1
unsigned long tx_bitmask;
};
struct tls_strparser {
struct sock *sk;
u32 mark : 8;
u32 stopped : 1;
u32 copy_mode : 1;
u32 msg_ready : 1;
struct strp_msg stm;
struct sk_buff *anchor;
struct work_struct work;
};
struct tls_sw_context_rx {
struct crypto_aead *aead_recv;
struct crypto_wait async_wait;
struct sk_buff_head rx_list; /* list of decrypted 'data' records */
void (*saved_data_ready)(struct sock *sk);
u8 reader_present;
u8 async_capable:1;
u8 zc_capable:1;
u8 reader_contended:1;
struct tls_strparser strp;
atomic_t decrypt_pending;
/* protect crypto_wait with decrypt_pending*/
spinlock_t decrypt_compl_lock;
struct sk_buff_head async_hold;
struct wait_queue_head wq;
};
struct tls_record_info {
struct list_head list;
u32 end_seq;
int len;
int num_frags;
skb_frag_t frags[MAX_SKB_FRAGS];
};
struct tls_offload_context_tx {
struct crypto_aead *aead_send;
spinlock_t lock; /* protects records list */
struct list_head records_list;
struct tls_record_info *open_record;
struct tls_record_info *retransmit_hint;
u64 hint_record_sn;
u64 unacked_record_sn;
struct scatterlist sg_tx_data[MAX_SKB_FRAGS];
void (*sk_destruct)(struct sock *sk);
struct work_struct destruct_work;
struct tls_context *ctx;
u8 driver_state[] __aligned(8);
/* The TLS layer reserves room for driver specific state
* Currently the belief is that there is not enough
* driver specific state to justify another layer of indirection
*/
#define TLS_DRIVER_STATE_SIZE_TX 16
};
#define TLS_OFFLOAD_CONTEXT_SIZE_TX \
(sizeof(struct tls_offload_context_tx) + TLS_DRIVER_STATE_SIZE_TX)
enum tls_context_flags {
/* tls_device_down was called after the netdev went down, device state
* was released, and kTLS works in software, even though rx_conf is
* still TLS_HW (needed for transition).
*/
TLS_RX_DEV_DEGRADED = 0,
/* Unlike RX where resync is driven entirely by the core in TX only
* the driver knows when things went out of sync, so we need the flag
* to be atomic.
*/
TLS_TX_SYNC_SCHED = 1,
/* tls_dev_del was called for the RX side, device state was released,
* but tls_ctx->netdev might still be kept, because TX-side driver
* resources might not be released yet. Used to prevent the second
* tls_dev_del call in tls_device_down if it happens simultaneously.
*/
TLS_RX_DEV_CLOSED = 2,
};
struct cipher_context {
char *iv;
char *rec_seq;
};
union tls_crypto_context {
struct tls_crypto_info info;
union {
struct tls12_crypto_info_aes_gcm_128 aes_gcm_128;
struct tls12_crypto_info_aes_gcm_256 aes_gcm_256;
struct tls12_crypto_info_chacha20_poly1305 chacha20_poly1305;
struct tls12_crypto_info_sm4_gcm sm4_gcm;
struct tls12_crypto_info_sm4_ccm sm4_ccm;
};
};
struct tls_prot_info {
u16 version;
u16 cipher_type;
u16 prepend_size;
u16 tag_size;
u16 overhead_size;
u16 iv_size;
u16 salt_size;
u16 rec_seq_size;
u16 aad_size;
u16 tail_size;
};
struct tls_context {
/* read-only cache line */
struct tls_prot_info prot_info;
u8 tx_conf:3;
u8 rx_conf:3;
u8 zerocopy_sendfile:1;
u8 rx_no_pad:1;
int (*push_pending_record)(struct sock *sk, int flags);
void (*sk_write_space)(struct sock *sk);
void *priv_ctx_tx;
void *priv_ctx_rx;
struct net_device __rcu *netdev;
/* rw cache line */
struct cipher_context tx;
struct cipher_context rx;
struct scatterlist *partially_sent_record;
u16 partially_sent_offset;
bool in_tcp_sendpages;
bool pending_open_record_frags;
struct mutex tx_lock; /* protects partially_sent_* fields and
* per-type TX fields
*/
unsigned long flags;
/* cache cold stuff */
struct proto *sk_proto;
struct sock *sk;
void (*sk_destruct)(struct sock *sk);
union tls_crypto_context crypto_send;
union tls_crypto_context crypto_recv;
struct list_head list;
refcount_t refcount;
struct rcu_head rcu;
};
enum tls_offload_ctx_dir {
TLS_OFFLOAD_CTX_DIR_RX,
TLS_OFFLOAD_CTX_DIR_TX,
};
struct tlsdev_ops {
int (*tls_dev_add)(struct net_device *netdev, struct sock *sk,
enum tls_offload_ctx_dir direction,
struct tls_crypto_info *crypto_info,
u32 start_offload_tcp_sn);
void (*tls_dev_del)(struct net_device *netdev,
struct tls_context *ctx,
enum tls_offload_ctx_dir direction);
int (*tls_dev_resync)(struct net_device *netdev,
struct sock *sk, u32 seq, u8 *rcd_sn,
enum tls_offload_ctx_dir direction);
};
enum tls_offload_sync_type {
TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ = 0,
TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT = 1,
TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ_ASYNC = 2,
};
#define TLS_DEVICE_RESYNC_NH_START_IVAL 2
#define TLS_DEVICE_RESYNC_NH_MAX_IVAL 128
#define TLS_DEVICE_RESYNC_ASYNC_LOGMAX 13
struct tls_offload_resync_async {
atomic64_t req;
u16 loglen;
u16 rcd_delta;
u32 log[TLS_DEVICE_RESYNC_ASYNC_LOGMAX];
};
struct tls_offload_context_rx {
/* sw must be the first member of tls_offload_context_rx */
struct tls_sw_context_rx sw;
enum tls_offload_sync_type resync_type;
/* this member is set regardless of resync_type, to avoid branches */
u8 resync_nh_reset:1;
/* CORE_NEXT_HINT-only member, but use the hole here */
u8 resync_nh_do_now:1;
union {
/* TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ */
struct {
atomic64_t resync_req;
};
/* TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT */
struct {
u32 decrypted_failed;
u32 decrypted_tgt;
} resync_nh;
/* TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ_ASYNC */
struct {
struct tls_offload_resync_async *resync_async;
};
};
u8 driver_state[] __aligned(8);
/* The TLS layer reserves room for driver specific state
* Currently the belief is that there is not enough
* driver specific state to justify another layer of indirection
*/
#define TLS_DRIVER_STATE_SIZE_RX 8
};
#define TLS_OFFLOAD_CONTEXT_SIZE_RX \
(sizeof(struct tls_offload_context_rx) + TLS_DRIVER_STATE_SIZE_RX)
struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context,
u32 seq, u64 *p_record_sn);
static inline bool tls_record_is_start_marker(struct tls_record_info *rec)
{
return rec->len == 0;
}
static inline u32 tls_record_start_seq(struct tls_record_info *rec)
{
return rec->end_seq - rec->len;
}
struct sk_buff *
tls_validate_xmit_skb(struct sock *sk, struct net_device *dev,
struct sk_buff *skb);
struct sk_buff *
tls_validate_xmit_skb_sw(struct sock *sk, struct net_device *dev,
struct sk_buff *skb);
static inline bool tls_is_sk_tx_device_offloaded(struct sock *sk)
{
#ifdef CONFIG_SOCK_VALIDATE_XMIT
return sk_fullsock(sk) &&
(smp_load_acquire(&sk->sk_validate_xmit_skb) ==
&tls_validate_xmit_skb);
#else
return false;
#endif
}
static inline struct tls_context *tls_get_ctx(const struct sock *sk)
{
struct inet_connection_sock *icsk = inet_csk(sk);
/* Use RCU on icsk_ulp_data only for sock diag code,
* TLS data path doesn't need rcu_dereference().
*/
return (__force void *)icsk->icsk_ulp_data;
}
static inline struct tls_sw_context_rx *tls_sw_ctx_rx(
const struct tls_context *tls_ctx)
{
return (struct tls_sw_context_rx *)tls_ctx->priv_ctx_rx;
}
static inline struct tls_sw_context_tx *tls_sw_ctx_tx(
const struct tls_context *tls_ctx)
{
return (struct tls_sw_context_tx *)tls_ctx->priv_ctx_tx;
}
static inline struct tls_offload_context_tx *
tls_offload_ctx_tx(const struct tls_context *tls_ctx)
{
return (struct tls_offload_context_tx *)tls_ctx->priv_ctx_tx;
}
static inline bool tls_sw_has_ctx_tx(const struct sock *sk)
{
struct tls_context *ctx = tls_get_ctx(sk);
if (!ctx)
return false;
return !!tls_sw_ctx_tx(ctx);
}
static inline bool tls_sw_has_ctx_rx(const struct sock *sk)
{
struct tls_context *ctx = tls_get_ctx(sk);
if (!ctx)
return false;
return !!tls_sw_ctx_rx(ctx);
}
static inline struct tls_offload_context_rx *
tls_offload_ctx_rx(const struct tls_context *tls_ctx)
{
return (struct tls_offload_context_rx *)tls_ctx->priv_ctx_rx;
}
static inline void *__tls_driver_ctx(struct tls_context *tls_ctx,
enum tls_offload_ctx_dir direction)
{
if (direction == TLS_OFFLOAD_CTX_DIR_TX)
return tls_offload_ctx_tx(tls_ctx)->driver_state;
else
return tls_offload_ctx_rx(tls_ctx)->driver_state;
}
static inline void *
tls_driver_ctx(const struct sock *sk, enum tls_offload_ctx_dir direction)
{
return __tls_driver_ctx(tls_get_ctx(sk), direction);
}
#define RESYNC_REQ BIT(0)
#define RESYNC_REQ_ASYNC BIT(1)
/* The TLS context is valid until sk_destruct is called */
static inline void tls_offload_rx_resync_request(struct sock *sk, __be32 seq)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
atomic64_set(&rx_ctx->resync_req, ((u64)ntohl(seq) << 32) | RESYNC_REQ);
}
/* Log all TLS record header TCP sequences in [seq, seq+len] */
static inline void
tls_offload_rx_resync_async_request_start(struct sock *sk, __be32 seq, u16 len)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
atomic64_set(&rx_ctx->resync_async->req, ((u64)ntohl(seq) << 32) |
((u64)len << 16) | RESYNC_REQ | RESYNC_REQ_ASYNC);
rx_ctx->resync_async->loglen = 0;
rx_ctx->resync_async->rcd_delta = 0;
}
static inline void
tls_offload_rx_resync_async_request_end(struct sock *sk, __be32 seq)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
atomic64_set(&rx_ctx->resync_async->req,
((u64)ntohl(seq) << 32) | RESYNC_REQ);
}
static inline void
tls_offload_rx_resync_set_type(struct sock *sk, enum tls_offload_sync_type type)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
tls_offload_ctx_rx(tls_ctx)->resync_type = type;
}
/* Driver's seq tracking has to be disabled until resync succeeded */
static inline bool tls_offload_tx_resync_pending(struct sock *sk)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
bool ret;
ret = test_bit(TLS_TX_SYNC_SCHED, &tls_ctx->flags);
smp_mb__after_atomic();
return ret;
}
struct sk_buff *tls_encrypt_skb(struct sk_buff *skb);
#ifdef CONFIG_TLS_DEVICE
void tls_device_sk_destruct(struct sock *sk);
void tls_offload_tx_resync_request(struct sock *sk, u32 got_seq, u32 exp_seq);
static inline bool tls_is_sk_rx_device_offloaded(struct sock *sk)
{
if (!sk_fullsock(sk) ||
smp_load_acquire(&sk->sk_destruct) != tls_device_sk_destruct)
return false;
return tls_get_ctx(sk)->rx_conf == TLS_HW;
}
#endif
#endif /* _TLS_OFFLOAD_H */