From 8f39b20488271aa53d30f5e1fe8407b1fd2bd2f8 Mon Sep 17 00:00:00 2001
From: SPRESENSE <41312067+SPRESENSE@users.noreply.github.com>
Date: Wed, 22 Jul 2020 17:51:47 +0900
Subject: [PATCH] net/usrsock: Fix recv() couldn't peek data

Fix a bug that recv() couldn't peek receive data.
recv() would be failed by previous recv() call with MSG_PEEK.
---
 net/usrsock/usrsock_recvfrom.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/net/usrsock/usrsock_recvfrom.c b/net/usrsock/usrsock_recvfrom.c
index 588ada77d9b..fd01cc1d8b3 100644
--- a/net/usrsock/usrsock_recvfrom.c
+++ b/net/usrsock/usrsock_recvfrom.c
@@ -424,6 +424,15 @@ ssize_t usrsock_recvfrom(FAR struct socket *psock, FAR void *buf, size_t len,
                */
 
               outaddrlen = state.valuelen_nontrunc;
+
+              /* If the MSG_PEEK flag is enabled, it will only peek
+               * from the buffer, so remark the input as ready.
+               */
+
+              if (flags & MSG_PEEK)
+                {
+                  conn->flags |= USRSOCK_EVENT_RECVFROM_AVAIL;
+                }
             }
         }