diff mbox series

[net,2/2] tls: fix waitall behavior in tls_sw_recvmsg

Message ID 20180615010746.3099-3-daniel@iogearbox.net
State Accepted, archived
Delegated to: David Miller
Headers show
Series Two tls fixes | expand

Commit Message

Daniel Borkmann June 15, 2018, 1:07 a.m. UTC
Current behavior in tls_sw_recvmsg() is to wait for incoming tls
messages and copy up to exactly len bytes of data that the user
provided. This is problematic in the sense that i) if no packet
is currently queued in strparser we keep waiting until one has been
processed and pushed into tls receive layer for tls_wait_data() to
wake up and push the decrypted bits to user space. Given after
tls decryption, we're back at streaming data, use sock_rcvlowat()
hint from tcp socket instead. Retain current behavior with MSG_WAITALL
flag and otherwise use the hint target for breaking the loop and
returning to application. This is done if currently no ctx->recv_pkt
is ready, otherwise continue to process it from our strparser
backlog.

Fixes: c46234ebb4d1 ("tls: RX path for ktls")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Dave Watson <davejwatson@fb.com>
---
 net/tls/tls_sw.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index 2945a3b..f127fac 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -754,7 +754,7 @@  int tls_sw_recvmsg(struct sock *sk,
 	struct sk_buff *skb;
 	ssize_t copied = 0;
 	bool cmsg = false;
-	int err = 0;
+	int target, err = 0;
 	long timeo;
 
 	flags |= nonblock;
@@ -764,6 +764,7 @@  int tls_sw_recvmsg(struct sock *sk,
 
 	lock_sock(sk);
 
+	target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
 	timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
 	do {
 		bool zc = false;
@@ -856,6 +857,9 @@  int tls_sw_recvmsg(struct sock *sk,
 					goto recv_end;
 			}
 		}
+		/* If we have a new message from strparser, continue now. */
+		if (copied >= target && !ctx->recv_pkt)
+			break;
 	} while (len);
 
 recv_end: