From c06bb7db560a8862ffa59c9a5065760d1e0f8080 Mon Sep 17 00:00:00 2001
From: Jacob Barthelmeh <jacob@wolfssl.com>
Date: Fri, 28 Dec 2018 11:02:25 -0700
Subject: [PATCH] modify wolfSSH_stream_send behavior with non blocking want
 write case

---
 src/internal.c |  1 +
 src/ssh.c      | 15 +++++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/src/internal.c b/src/internal.c
index 599b27c..ae87690 100644
--- a/src/internal.c
+++ b/src/internal.c
@@ -1371,6 +1371,7 @@ int wolfSSH_SendPacket(WOLFSSH* ssh)
         if (sent < 0) {
             switch (sent) {
                 case WS_CBIO_ERR_WANT_WRITE:     /* want write, would block */
+                    ssh->error = WS_WANT_WRITE;
                     return WS_WANT_WRITE;
 
                 case WS_CBIO_ERR_CONN_RST:       /* connection reset */
diff --git a/src/ssh.c b/src/ssh.c
index 4af7ce4..f9df2ff 100644
--- a/src/ssh.c
+++ b/src/ssh.c
@@ -753,6 +753,21 @@ int wolfSSH_stream_send(WOLFSSH* ssh, byte* buf, word32 bufSz)
 
     if (ssh == NULL || buf == NULL || ssh->channelList == NULL)
         return WS_BAD_ARGUMENT;
+
+    /* case of WANT WRITE and data stored in output buffer */
+    if (ssh->error == WS_WANT_WRITE && ssh->outputBuffer.length != 0) {
+        int ret;
+
+        bytesTxd = ssh->outputBuffer.length;
+        WLOG(WS_LOG_DEBUG, "Trying to resend %d bytes\n", bytesTxd);
+        ssh->error = WS_SUCCESS;
+        ret = wolfSSH_SendPacket(ssh);
+
+        /* return the amount sent on success otherwise return error found */
+        return (ret == WS_SUCCESS)?
+            bytesTxd - (int)ssh->outputBuffer.length : ret;
+    }
+
     bytesTxd = SendChannelData(ssh, ssh->channelList->peerChannel, buf, bufSz);
 
     WLOG(WS_LOG_DEBUG, "Leaving wolfSSH_stream_send(), txd = %d", bytesTxd);