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Merge branch 'tls-pad-strparser-internal-header-decrypt_ctx-etc'
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Jakub Kicinski says:

====================
tls: pad strparser, internal header, decrypt_ctx etc.

A grab bag of non-functional refactoring to make the series
which will let us decrypt into a fresh skb smaller.

Patches in this series are not strictly required to get the
decryption into a fresh skb going, they are more in the "things
which had been annoying me for a while" category.
====================

Link: https://lore.kernel.org/r/20220708010314.1451462-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Jakub Kicinski committed Jul 9, 2022
2 parents 67d7ebd + 35560b7 commit 16bd188
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Showing 10 changed files with 418 additions and 359 deletions.
12 changes: 8 additions & 4 deletions include/net/strparser.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -65,15 +65,19 @@ struct _strp_msg {
struct sk_skb_cb {
#define SK_SKB_CB_PRIV_LEN 20
unsigned char data[SK_SKB_CB_PRIV_LEN];
/* align strp on cache line boundary within skb->cb[] */
unsigned char pad[4];
struct _strp_msg strp;
/* temp_reg is a temporary register used for bpf_convert_data_end_access
* when dst_reg == src_reg.
*/
u64 temp_reg;

/* strp users' data follows */
struct tls_msg {
u8 control;
u8 decrypted;
} tls;
/* temp_reg is a temporary register used for bpf_convert_data_end_access
* when dst_reg == src_reg.
*/
u64 temp_reg;
};

static inline struct strp_msg *strp_msg(struct sk_buff *skb)
Expand Down
278 changes: 2 additions & 276 deletions include/net/tls.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -39,7 +39,6 @@
#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>
Expand All @@ -50,6 +49,7 @@
#include <crypto/aead.h>
#include <uapi/linux/tls.h>

struct tls_rec;

/* Maximum data size carried in a TLS record */
#define TLS_MAX_PAYLOAD_SIZE ((size_t)1 << 14)
Expand All @@ -66,6 +66,7 @@
#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.
*
Expand All @@ -77,13 +78,6 @@
#define TLS_AES_CCM_IV_B0_BYTE 2
#define TLS_SM4_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)

enum {
TLS_BASE,
TLS_SW,
Expand All @@ -92,32 +86,6 @@ enum {
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 tx_work {
struct delayed_work work;
struct sock *sk;
Expand Down Expand Up @@ -348,44 +316,6 @@ struct tls_offload_context_rx {
#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);
void tls_err_abort(struct sock *sk, int err);

int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx);
void tls_update_rx_zc_capable(struct tls_context *tls_ctx);
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 flags, int *addr_len);
bool tls_sw_sock_is_readable(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);

Expand All @@ -399,58 +329,6 @@ 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)
{
struct sk_skb_cb *scb = (struct sk_skb_cb *)skb->cb;

return &scb->tls;
}

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);
Expand All @@ -469,31 +347,6 @@ static inline bool tls_is_sk_tx_device_offloaded(struct sock *sk)
#endif
}

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 void tls_bigint_subtract(unsigned char *seq, int n)
{
u64 rcd_sn;
__be64 *p;

BUILD_BUG_ON(TLS_MAX_REC_SEQ_SIZE != 8);

p = (__be64 *)seq;
rcd_sn = be64_to_cpu(*p);
*p = cpu_to_be64(rcd_sn - n);
}

static inline struct tls_context *tls_get_ctx(const struct sock *sk)
{
struct inet_connection_sock *icsk = inet_csk(sk);
Expand All @@ -504,82 +357,6 @@ static inline struct tls_context *tls_get_ctx(const struct sock *sk)
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 &&
prot->cipher_type != TLS_CIPHER_CHACHA20_POLY1305)
tls_bigint_increment(ctx->iv + prot->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)
{
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 (prot->version != TLS_1_3_VERSION &&
prot->cipher_type != TLS_CIPHER_CHACHA20_POLY1305) {
pkt_len += iv_size;

memcpy(buf + TLS_NONCE_OFFSET,
ctx->tx.iv + prot->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] = prot->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,
unsigned char record_type,
struct tls_prot_info *prot)
{
if (prot->version != TLS_1_3_VERSION) {
memcpy(buf, record_sequence, prot->rec_seq_size);
buf += 8;
} else {
size += prot->tag_size;
}

buf[0] = prot->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(struct tls_prot_info *prot, char *iv, char *seq)
{
int i;

if (prot->version == TLS_1_3_VERSION ||
prot->cipher_type == TLS_CIPHER_CHACHA20_POLY1305) {
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)
{
Expand Down Expand Up @@ -616,9 +393,6 @@ static inline bool tls_sw_has_ctx_rx(const struct sock *sk)
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)
{
Expand Down Expand Up @@ -693,31 +467,11 @@ static inline bool tls_offload_tx_resync_pending(struct sock *sk)
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);

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)
{
Expand All @@ -726,33 +480,5 @@ static inline bool tls_is_sk_rx_device_offloaded(struct sock *sk)
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 */
3 changes: 3 additions & 0 deletions net/strparser/strparser.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -533,6 +533,9 @@ EXPORT_SYMBOL_GPL(strp_check_rcv);

static int __init strp_dev_init(void)
{
BUILD_BUG_ON(sizeof(struct sk_skb_cb) >
sizeof_field(struct sk_buff, cb));

strp_wq = create_singlethread_workqueue("kstrp");
if (unlikely(!strp_wq))
return -ENOMEM;
Expand Down
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