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xiaoxiang pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/incubator-nuttx.git
The following commit(s) were added to refs/heads/master by this push:
new a885b24 Attempt to fix race condition reported in issue #3647
a885b24 is described below
commit a885b24cc1bbb9a97230da0820843981839ca01a
Author: Anthony Merlino <anth...@vergeaero.com>
AuthorDate: Mon May 3 13:01:31 2021 -0400
Attempt to fix race condition reported in issue #3647
---
net/tcp/tcp_send_unbuffered.c | 20 ++++++++++++++++++--
1 file changed, 18 insertions(+), 2 deletions(-)
diff --git a/net/tcp/tcp_send_unbuffered.c b/net/tcp/tcp_send_unbuffered.c
index 64e41a1..d487318 100644
--- a/net/tcp/tcp_send_unbuffered.c
+++ b/net/tcp/tcp_send_unbuffered.c
@@ -538,9 +538,12 @@ ssize_t psock_tcp_send(FAR struct socket *psock,
goto errout;
}
- /* If this is an un-connected socket, then return ENOTCONN */
+ /* Check early if this is an un-connected socket, if so, then
+ * return -ENOTCONN. Note, we will have to check this again, as we can't
+ * guarantee the state won't change until we have the network locked.
+ */
- if (psock->s_type != SOCK_STREAM || !_SS_ISCONNECTED(psock->s_flags))
+ if (psock->s_type != SOCK_STREAM)
{
nerr("ERROR: Not connected\n");
ret = -ENOTCONN;
@@ -593,6 +596,19 @@ ssize_t psock_tcp_send(FAR struct socket *psock,
*/
net_lock();
+
+ /* Now that we have the network locked, we need to check the connection
+ * state again to ensure the connection is still valid.
+ */
+
+ if (!_SS_ISCONNECTED(psock->s_flags))
+ {
+ nerr("ERROR: No longer connected\n");
+ net_unlock();
+ ret = -ENOTCONN;
+ goto errout;
+ }
+
memset(&state, 0, sizeof(struct send_s));
/* This semaphore is used for signaling and, hence, should not have
