From d494ffecfc27fc16d72451c57e7e017273652f31 Mon Sep 17 00:00:00 2001
From: XANTRONIX Development <dev@xantronix.com>
Date: Sun, 19 Jul 2020 20:27:56 -0400
Subject: [PATCH] Fix issues encoding extended frame control fields

Changes:

    * When encoding extended frame control fields, ensure the least
      significant byte is written first, as per the AX.25 v2.2 standard
---
 src/sock.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/sock.c b/src/sock.c
index a0c3f5e..6750607 100644
--- a/src/sock.c
+++ b/src/sock.c
@@ -332,14 +332,19 @@ ssize_t patty_ax25_sock_send(patty_ax25_sock *sock,
     offset = addr_copy_to_buf(buf, sock, cr);
 
     if (sock->mode == PATTY_AX25_SOCK_SABME) {
-        buf[offset++] = (control & 0xff00) >> 8;
-        buf[offset++] =  control & 0x00ff;
+        buf[offset++] = control & 0x00ff;
+
+        if (!(PATTY_AX25_FRAME_CONTROL_U(control))) {
+            buf[offset++] = (control & 0xff00) >> 8;
+        }
     } else {
         buf[offset++] = control;
     }
 
     if (info) {
-        buf[offset++] = (uint8_t)sock->proto;
+        if (PATTY_AX25_FRAME_CONTROL_I(control)) {
+            buf[offset++] = (uint8_t)sock->proto;
+        }
 
         memcpy(buf + offset, info, infolen);
         offset += infolen;
@@ -498,9 +503,7 @@ ssize_t patty_ax25_sock_send_xid(patty_ax25_sock *sock) {
                 | PATTY_AX25_PARAM_HDLC_MODULO_128
                 | PATTY_AX25_PARAM_HDLC_SYNC_TX;
 
-    params.info_tx   = sock->n_maxlen_tx;
     params.info_rx   = sock->n_maxlen_rx;
-    params.window_tx = sock->n_window_tx;
     params.window_rx = sock->n_window_rx;
     params.ack       = sock->n_ack;
     params.retry     = sock->n_retry;