From ed9b7646b06a2ed2450dd9437fc7d1ad2783140c Mon Sep 17 00:00:00 2001 From: Boris Pismenny Date: Mon, 8 Jun 2020 19:11:38 +0300 Subject: [PATCH] net/tls: Add asynchronous resync This patch adds support for asynchronous resynchronization in tls_device. Async resync follows two distinct stages: 1. The NIC driver indicates that it would like to resync on some TLS record within the received packet (P), but the driver does not know (yet) which of the TLS records within the packet. At this stage, the NIC driver will query the device to find the exact TCP sequence for resync (tcpsn), however, the driver does not wait for the device to provide the response. 2. Eventually, the device responds, and the driver provides the tcpsn within the resync packet to KTLS. Now, KTLS can check the tcpsn against any processed TLS records within packet P, and also against any record that is processed in the future within packet P. The asynchronous resync path simplifies the device driver, as it can save bits on the packet completion (32-bit TCP sequence), and pass this information on an asynchronous command instead. Signed-off-by: Boris Pismenny Signed-off-by: Tariq Toukan Signed-off-by: Saeed Mahameed --- include/net/tls.h | 38 ++++++++++++++++++++++++++++++++- net/tls/tls_device.c | 51 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 88 insertions(+), 1 deletion(-) diff --git a/include/net/tls.h b/include/net/tls.h index ca5f7f437289..c875c0a445a6 100644 --- a/include/net/tls.h +++ b/include/net/tls.h @@ -291,11 +291,19 @@ struct tlsdev_ops { 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; + u32 loglen; + 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; @@ -314,6 +322,10 @@ struct tls_offload_context_rx { 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 @@ -606,13 +618,37 @@ tls_driver_ctx(const struct sock *sk, enum tls_offload_ctx_dir direction) } #endif +#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) | 1); + 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) | + (len << 16) | RESYNC_REQ | RESYNC_REQ_ASYNC); + rx_ctx->resync_async->loglen = 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 diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c index a562ebaaa33c..18fa6067bb7f 100644 --- a/net/tls/tls_device.c +++ b/net/tls/tls_device.c @@ -690,6 +690,47 @@ static void tls_device_resync_rx(struct tls_context *tls_ctx, TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSRXDEVICERESYNC); } +static bool +tls_device_rx_resync_async(struct tls_offload_resync_async *resync_async, + s64 resync_req, u32 *seq) +{ + u32 is_async = resync_req & RESYNC_REQ_ASYNC; + u32 req_seq = resync_req >> 32; + u32 req_end = req_seq + ((resync_req >> 16) & 0xffff); + + if (is_async) { + /* asynchronous stage: log all headers seq such that + * req_seq <= seq <= end_seq, and wait for real resync request + */ + if (between(*seq, req_seq, req_end) && + resync_async->loglen < TLS_DEVICE_RESYNC_ASYNC_LOGMAX) + resync_async->log[resync_async->loglen++] = *seq; + + return false; + } + + /* synchronous stage: check against the logged entries and + * proceed to check the next entries if no match was found + */ + while (resync_async->loglen) { + if (req_seq == resync_async->log[resync_async->loglen - 1] && + atomic64_try_cmpxchg(&resync_async->req, + &resync_req, 0)) { + resync_async->loglen = 0; + *seq = req_seq; + return true; + } + resync_async->loglen--; + } + + if (req_seq == *seq && + atomic64_try_cmpxchg(&resync_async->req, + &resync_req, 0)) + return true; + + return false; +} + void tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq) { struct tls_context *tls_ctx = tls_get_ctx(sk); @@ -736,6 +777,16 @@ void tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq) seq += rcd_len; tls_bigint_increment(rcd_sn, prot->rec_seq_size); break; + case TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ_ASYNC: + resync_req = atomic64_read(&rx_ctx->resync_async->req); + is_req_pending = resync_req; + if (likely(!is_req_pending)) + return; + + if (!tls_device_rx_resync_async(rx_ctx->resync_async, + resync_req, &seq)) + return; + break; } tls_device_resync_rx(tls_ctx, sk, seq, rcd_sn);