tls: rx: don't consider sock_rcvtimeo() cumulative

Eric indicates that restarting rcvtimeo on every wait may be fine.
I thought that we should consider it cumulative, and made
tls_rx_reader_lock() return the remaining timeo after acquiring
the reader lock.

tls_rx_rec_wait() gets its timeout passed in by value so it
does not keep track of time previously spent.

Make the lock waiting consistent with tls_rx_rec_wait() - don't
keep track of time spent.

Read the timeo fresh in tls_rx_rec_wait().
It's unclear to me why callers are supposed to cache the value.

Link: https://lore.kernel.org/all/CANn89iKcmSfWgvZjzNGbsrndmCch2HC_EPZ7qmGboDNaWoviNQ@mail.gmail.com/
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index 0fc24a5..8bac7ea 100644 (file)
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -1283,11 +1283,14 @@ int tls_sw_sendpage(struct sock *sk, struct page *page,
 
 static int
 tls_rx_rec_wait(struct sock *sk, struct sk_psock *psock, bool nonblock,
-               bool released, long timeo)
+               bool released)
 {
        struct tls_context *tls_ctx = tls_get_ctx(sk);
        struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
        DEFINE_WAIT_FUNC(wait, woken_wake_function);
+       long timeo;
+
+       timeo = sock_rcvtimeo(sk, nonblock);
 
        while (!tls_strp_msg_ready(ctx)) {
                if (!sk_psock_queue_empty(psock))
@@ -1308,7 +1311,7 @@ tls_rx_rec_wait(struct sock *sk, struct sk_psock *psock, bool nonblock,
                if (sock_flag(sk, SOCK_DONE))
                        return 0;
 
-               if (nonblock || !timeo)
+               if (!timeo)
                        return -EAGAIN;
 
                released = true;
@@ -1842,8 +1845,8 @@ tls_read_flush_backlog(struct sock *sk, struct tls_prot_info *prot,
        return sk_flush_backlog(sk);
 }
 
-static long tls_rx_reader_lock(struct sock *sk, struct tls_sw_context_rx *ctx,
-                              bool nonblock)
+static int tls_rx_reader_lock(struct sock *sk, struct tls_sw_context_rx *ctx,
+                             bool nonblock)
 {
        long timeo;
        int err;
@@ -1874,7 +1877,7 @@ static long tls_rx_reader_lock(struct sock *sk, struct tls_sw_context_rx *ctx,
 
        WRITE_ONCE(ctx->reader_present, 1);
 
-       return timeo;
+       return 0;
 
 err_unlock:
        release_sock(sk);
@@ -1913,8 +1916,7 @@ int tls_sw_recvmsg(struct sock *sk,
        struct tls_msg *tlm;
        ssize_t copied = 0;
        bool async = false;
-       int target, err = 0;
-       long timeo;
+       int target, err;
        bool is_kvec = iov_iter_is_kvec(&msg->msg_iter);
        bool is_peek = flags & MSG_PEEK;
        bool released = true;
@@ -1925,9 +1927,9 @@ int tls_sw_recvmsg(struct sock *sk,
                return sock_recv_errqueue(sk, msg, len, SOL_IP, IP_RECVERR);
 
        psock = sk_psock_get(sk);
-       timeo = tls_rx_reader_lock(sk, ctx, flags & MSG_DONTWAIT);
-       if (timeo < 0)
-               return timeo;
+       err = tls_rx_reader_lock(sk, ctx, flags & MSG_DONTWAIT);
+       if (err < 0)
+               return err;
        bpf_strp_enabled = sk_psock_strp_enabled(psock);
 
        /* If crypto failed the connection is broken */
@@ -1954,8 +1956,8 @@ int tls_sw_recvmsg(struct sock *sk,
                struct tls_decrypt_arg darg;
                int to_decrypt, chunk;
 
-               err = tls_rx_rec_wait(sk, psock, flags & MSG_DONTWAIT, released,
-                                     timeo);
+               err = tls_rx_rec_wait(sk, psock, flags & MSG_DONTWAIT,
+                                     released);
                if (err <= 0) {
                        if (psock) {
                                chunk = sk_msg_recvmsg(sk, psock, msg, len,
@@ -2131,13 +2133,12 @@ ssize_t tls_sw_splice_read(struct socket *sock,  loff_t *ppos,
        struct tls_msg *tlm;
        struct sk_buff *skb;
        ssize_t copied = 0;
-       int err = 0;
-       long timeo;
        int chunk;
+       int err;
 
-       timeo = tls_rx_reader_lock(sk, ctx, flags & SPLICE_F_NONBLOCK);
-       if (timeo < 0)
-               return timeo;
+       err = tls_rx_reader_lock(sk, ctx, flags & SPLICE_F_NONBLOCK);
+       if (err < 0)
+               return err;
 
        if (!skb_queue_empty(&ctx->rx_list)) {
                skb = __skb_dequeue(&ctx->rx_list);
@@ -2145,7 +2146,7 @@ ssize_t tls_sw_splice_read(struct socket *sock,  loff_t *ppos,
                struct tls_decrypt_arg darg;
 
                err = tls_rx_rec_wait(sk, NULL, flags & SPLICE_F_NONBLOCK,
-                                     true, timeo);
+                                     true);
                if (err <= 0)
                        goto splice_read_end;