linux/include/net/tls.h
Jakub Kicinski 8d5a49e9e3 net/tls: add helper for testing if socket is RX offloaded
There is currently no way for driver to reliably check that
the socket it has looked up is in fact RX offloaded. Add
a helper. This allows drivers to catch misbehaving firmware.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-19 17:46:51 -08:00

691 lines
19 KiB
C

/*
* 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;
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;
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);
}
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 */
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) | 1);
}
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 */