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/skmsg.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>
/* 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_MAX_REC_SEQ_SIZE 8
/* For AES-CCM, 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_INC_STATS(net, field) \
__SNMP_INC_STATS((net)->mib.tls_statistics, field)
#define TLS_INC_STATS(net, field) \
SNMP_INC_STATS((net)->mib.tls_statistics, field)
#define __TLS_DEC_STATS(net, field) \
__SNMP_DEC_STATS((net)->mib.tls_statistics, field)
#define TLS_DEC_STATS(net, field) \
SNMP_DEC_STATS((net)->mib.tls_statistics, field)
enum {
TLS_BASE,
TLS_SW,
TLS_HW,
TLS_HW_RECORD,
TLS_NUM_CONFIG,
};
/* TLS records are maintained in 'struct tls_rec'. It stores the memory pages
* allocated or mapped for each TLS record. After encryption, the records are
* stores in a linked list.
*/
struct tls_rec {
struct list_head list;
int tx_ready;
int tx_flags;
struct sk_msg msg_plaintext;
struct sk_msg msg_encrypted;
/* AAD | msg_plaintext.sg.data | sg_tag */
struct scatterlist sg_aead_in[2];
/* AAD | msg_encrypted.sg.data (data contains overhead for hdr & iv & tag) */
struct scatterlist sg_aead_out[2];
char content_type;
struct scatterlist sg_content_type;
char aad_space[TLS_AAD_SPACE_SIZE];
u8 iv_data[MAX_IV_SIZE];
struct aead_request aead_req;
u8 aead_req_ctx[];
};
struct tls_msg {
struct strp_msg rxm;
u8 control;
};
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_sw_context_rx {
struct crypto_aead *aead_recv;
struct crypto_wait async_wait;
struct strparser strp;
struct sk_buff_head rx_list; /* list of decrypted 'data' records */
void (*saved_data_ready)(struct sock *sk);
struct sk_buff *recv_pkt;
u8 control;
u8 async_capable:1;
u8 decrypted:1;
atomic_t decrypt_pending;
/* protect crypto_wait with decrypt_pending*/
spinlock_t decrypt_compl_lock;
bool async_notify;
};
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);
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_RX_SYNC_RUNNING = 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,
};
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 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;
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 *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;
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,
};
#define TLS_DEVICE_RESYNC_NH_START_IVAL 2
#define TLS_DEVICE_RESYNC_NH_MAX_IVAL 128
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;
};
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_context *tls_ctx_create(struct sock *sk);
void tls_ctx_free(struct sock *sk, struct tls_context *ctx);
void update_sk_prot(struct sock *sk, struct tls_context *ctx);
int wait_on_pending_writer(struct sock *sk, long *timeo);
int tls_sk_query(struct sock *sk, int optname, char __user *optval,
int __user *optlen);
int tls_sk_attach(struct sock *sk, int optname, char __user *optval,
unsigned int optlen);
int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx);
void tls_sw_strparser_arm(struct sock *sk, struct tls_context *ctx);
void tls_sw_strparser_done(struct tls_context *tls_ctx);
int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
int tls_sw_sendpage_locked(struct sock *sk, struct page *page,
int offset, size_t size, int flags);
int tls_sw_sendpage(struct sock *sk, struct page *page,
int offset, size_t size, int flags);
void tls_sw_cancel_work_tx(struct tls_context *tls_ctx);
void tls_sw_release_resources_tx(struct sock *sk);
void tls_sw_free_ctx_tx(struct tls_context *tls_ctx);
void tls_sw_free_resources_rx(struct sock *sk);
void tls_sw_release_resources_rx(struct sock *sk);
void tls_sw_free_ctx_rx(struct tls_context *tls_ctx);
int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
int nonblock, int flags, int *addr_len);
bool tls_sw_stream_read(const struct sock *sk);
ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos,
struct pipe_inode_info *pipe,
size_t len, unsigned int flags);
int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
int tls_device_sendpage(struct sock *sk, struct page *page,
int offset, size_t size, int flags);
int tls_tx_records(struct sock *sk, int flags);
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;
}
int tls_push_sg(struct sock *sk, struct tls_context *ctx,
struct scatterlist *sg, u16 first_offset,
int flags);
int tls_push_partial_record(struct sock *sk, struct tls_context *ctx,
int flags);
void tls_free_partial_record(struct sock *sk, struct tls_context *ctx);
static inline struct tls_msg *tls_msg(struct sk_buff *skb)
{
return (struct tls_msg *)strp_msg(skb);
}
static inline bool tls_is_partially_sent_record(struct tls_context *ctx)
{
return !!ctx->partially_sent_record;
}
static inline bool tls_is_pending_open_record(struct tls_context *tls_ctx)
{
return tls_ctx->pending_open_record_frags;
}
static inline bool is_tx_ready(struct tls_sw_context_tx *ctx)
{
struct tls_rec *rec;
rec = list_first_entry(&ctx->tx_list, struct tls_rec, list);
if (!rec)
return false;
return READ_ONCE(rec->tx_ready);
}
static inline u16 tls_user_config(struct tls_context *ctx, bool tx)
{
u16 config = tx ? ctx->tx_conf : ctx->rx_conf;
switch (config) {
case TLS_BASE:
return TLS_CONF_BASE;
case TLS_SW:
return TLS_CONF_SW;
case TLS_HW:
return TLS_CONF_HW;
case TLS_HW_RECORD:
return TLS_CONF_HW_RECORD;
}
return 0;
}
struct sk_buff *
tls_validate_xmit_skb(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 void tls_err_abort(struct sock *sk, int err)
{
sk->sk_err = err;
sk->sk_error_report(sk);
}
static inline bool tls_bigint_increment(unsigned char *seq, int len)
{
int i;
for (i = len - 1; i >= 0; i--) {
++seq[i];
if (seq[i] != 0)
break;
}
return (i == -1);
}
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 void tls_advance_record_sn(struct sock *sk,
struct tls_prot_info *prot,
struct cipher_context *ctx)
{
if (tls_bigint_increment(ctx->rec_seq, prot->rec_seq_size))
tls_err_abort(sk, EBADMSG);
if (prot->version != TLS_1_3_VERSION)
tls_bigint_increment(ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
prot->iv_size);
}
static inline void tls_fill_prepend(struct tls_context *ctx,
char *buf,
size_t plaintext_len,
unsigned char record_type,
int version)
{
struct tls_prot_info *prot = &ctx->prot_info;
size_t pkt_len, iv_size = prot->iv_size;
pkt_len = plaintext_len + prot->tag_size;
if (version != TLS_1_3_VERSION) {
pkt_len += iv_size;
memcpy(buf + TLS_NONCE_OFFSET,
ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv_size);
}
/* we cover nonce explicit here as well, so buf should be of
* size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
*/
buf[0] = version == TLS_1_3_VERSION ?
TLS_RECORD_TYPE_DATA : record_type;
/* Note that VERSION must be TLS_1_2 for both TLS1.2 and TLS1.3 */
buf[1] = TLS_1_2_VERSION_MINOR;
buf[2] = TLS_1_2_VERSION_MAJOR;
/* we can use IV for nonce explicit according to spec */
buf[3] = pkt_len >> 8;
buf[4] = pkt_len & 0xFF;
}
static inline void tls_make_aad(char *buf,
size_t size,
char *record_sequence,
int record_sequence_size,
unsigned char record_type,
int version)
{
if (version != TLS_1_3_VERSION) {
memcpy(buf, record_sequence, record_sequence_size);
buf += 8;
} else {
size += TLS_CIPHER_AES_GCM_128_TAG_SIZE;
}
buf[0] = version == TLS_1_3_VERSION ?
TLS_RECORD_TYPE_DATA : record_type;
buf[1] = TLS_1_2_VERSION_MAJOR;
buf[2] = TLS_1_2_VERSION_MINOR;
buf[3] = size >> 8;
buf[4] = size & 0xFF;
}
static inline void xor_iv_with_seq(int version, char *iv, char *seq)
{
int i;
if (version == TLS_1_3_VERSION) {
for (i = 0; i < 8; i++)
iv[i + 4] ^= seq[i];
}
}
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);
}
void tls_sw_write_space(struct sock *sk, struct tls_context *ctx);
void tls_device_write_space(struct sock *sk, struct tls_context *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;
}
#if IS_ENABLED(CONFIG_TLS_DEVICE)
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);
}
#endif
/* The TLS context is valid until sk_destruct is called */
#define RESYNC_REQ (1 << 0)
#define RESYNC_REQ_FORCE (1 << 1)
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);
}
static inline void tls_offload_rx_force_resync_request(struct sock *sk)
{
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, RESYNC_REQ | RESYNC_REQ_FORCE);
}
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;
}
int __net_init tls_proc_init(struct net *net);
void __net_exit tls_proc_fini(struct net *net);
int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
unsigned char *record_type);
int decrypt_skb(struct sock *sk, struct sk_buff *skb,
struct scatterlist *sgout);
struct sk_buff *tls_encrypt_skb(struct sk_buff *skb);
struct sk_buff *tls_validate_xmit_skb(struct sock *sk,
struct net_device *dev,
struct sk_buff *skb);
int tls_sw_fallback_init(struct sock *sk,
struct tls_offload_context_tx *offload_ctx,
struct tls_crypto_info *crypto_info);
#ifdef CONFIG_TLS_DEVICE
void tls_device_init(void);
void tls_device_cleanup(void);
void tls_device_sk_destruct(struct sock *sk);
int tls_set_device_offload(struct sock *sk, struct tls_context *ctx);
void tls_device_free_resources_tx(struct sock *sk);
int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx);
void tls_device_offload_cleanup_rx(struct sock *sk);
void tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq);
void tls_offload_tx_resync_request(struct sock *sk, u32 got_seq, u32 exp_seq);
int tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx,
struct sk_buff *skb, struct strp_msg *rxm);
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;
}
#else
static inline void tls_device_init(void) {}
static inline void tls_device_cleanup(void) {}
static inline int
tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
{
return -EOPNOTSUPP;
}
static inline void tls_device_free_resources_tx(struct sock *sk) {}
static inline int
tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
{
return -EOPNOTSUPP;
}
static inline void tls_device_offload_cleanup_rx(struct sock *sk) {}
static inline void
tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq) {}
static inline int
tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx,
struct sk_buff *skb, struct strp_msg *rxm)
{
return 0;
}
#endif
#endif /* _TLS_OFFLOAD_H */