Allow splice to end a TLS record after prematurely ending a splice/sendfile due to getting an EOF condition (->splice_read() returned 0) after splice had called TLS with a sendmsg() with MSG_MORE set when the user didn't set MSG_MORE. Suggested-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/CAHk-=wh=V579PDYvkpnTobCLGczbgxpMgGmmhqiTyE34Cpi5Gg@xxxxxxxxxxxxxx/ Signed-off-by: David Howells <dhowells@xxxxxxxxxx> cc: Chuck Lever <chuck.lever@xxxxxxxxxx> cc: Boris Pismenny <borisp@xxxxxxxxxx> cc: John Fastabend <john.fastabend@xxxxxxxxx> cc: Jakub Kicinski <kuba@xxxxxxxxxx> cc: Eric Dumazet <edumazet@xxxxxxxxxx> cc: "David S. Miller" <davem@xxxxxxxxxxxxx> cc: Paolo Abeni <pabeni@xxxxxxxxxx> cc: Jens Axboe <axboe@xxxxxxxxx> cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> cc: netdev@xxxxxxxxxxxxxxx --- net/tls/tls.h | 1 + net/tls/tls_main.c | 2 ++ net/tls/tls_sw.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 77 insertions(+) diff --git a/net/tls/tls.h b/net/tls/tls.h index 0672acab2773..4922668fefaa 100644 --- a/net/tls/tls.h +++ b/net/tls/tls.h @@ -97,6 +97,7 @@ 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); +void tls_sw_splice_eof(struct socket *sock); 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, diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c index e02a0d882ed3..82ec5c654f32 100644 --- a/net/tls/tls_main.c +++ b/net/tls/tls_main.c @@ -957,6 +957,7 @@ static void build_proto_ops(struct proto_ops ops[TLS_NUM_CONFIG][TLS_NUM_CONFIG] ops[TLS_BASE][TLS_BASE] = *base; ops[TLS_SW ][TLS_BASE] = ops[TLS_BASE][TLS_BASE]; + ops[TLS_SW ][TLS_BASE].splice_eof = tls_sw_splice_eof; ops[TLS_SW ][TLS_BASE].sendpage_locked = tls_sw_sendpage_locked; ops[TLS_BASE][TLS_SW ] = ops[TLS_BASE][TLS_BASE]; @@ -1027,6 +1028,7 @@ static void build_protos(struct proto prot[TLS_NUM_CONFIG][TLS_NUM_CONFIG], prot[TLS_SW][TLS_BASE] = prot[TLS_BASE][TLS_BASE]; prot[TLS_SW][TLS_BASE].sendmsg = tls_sw_sendmsg; + prot[TLS_SW][TLS_BASE].splice_eof = tls_sw_splice_eof; prot[TLS_SW][TLS_BASE].sendpage = tls_sw_sendpage; prot[TLS_BASE][TLS_SW] = prot[TLS_BASE][TLS_BASE]; diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index 38acc27a0dd0..a2fb0256ff1c 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -1157,6 +1157,80 @@ int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size) return copied > 0 ? copied : ret; } +/* + * Handle unexpected EOF during splice without SPLICE_F_MORE set. + */ +void tls_sw_splice_eof(struct socket *sock) +{ + struct sock *sk = sock->sk; + struct tls_context *tls_ctx = tls_get_ctx(sk); + struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx); + struct tls_rec *rec; + struct sk_msg *msg_pl; + ssize_t copied = 0; + bool retrying = false; + int ret = 0; + int pending; + + if (!ctx->open_rec) + return; + + mutex_lock(&tls_ctx->tx_lock); + lock_sock(sk); + +retry: + rec = ctx->open_rec; + if (!rec) + goto unlock; + + msg_pl = &rec->msg_plaintext; + + /* Check the BPF advisor and perform transmission. */ + ret = bpf_exec_tx_verdict(msg_pl, sk, false, TLS_RECORD_TYPE_DATA, + &copied, 0); + switch (ret) { + case 0: + case -EAGAIN: + if (retrying) + goto unlock; + retrying = true; + goto retry; + case -EINPROGRESS: + break; + default: + goto unlock; + } + + /* Wait for pending encryptions to get completed */ + spin_lock_bh(&ctx->encrypt_compl_lock); + ctx->async_notify = true; + + pending = atomic_read(&ctx->encrypt_pending); + spin_unlock_bh(&ctx->encrypt_compl_lock); + if (pending) + crypto_wait_req(-EINPROGRESS, &ctx->async_wait); + else + reinit_completion(&ctx->async_wait.completion); + + /* There can be no concurrent accesses, since we have no pending + * encrypt operations + */ + WRITE_ONCE(ctx->async_notify, false); + + if (ctx->async_wait.err) + goto unlock; + + /* Transmit if any encryptions have completed */ + if (test_and_clear_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask)) { + cancel_delayed_work(&ctx->tx_work.work); + tls_tx_records(sk, 0); + } + +unlock: + release_sock(sk); + mutex_unlock(&tls_ctx->tx_lock); +} + static int tls_sw_do_sendpage(struct sock *sk, struct page *page, int offset, size_t size, int flags) {
