slirp: tftp: Cleanup tftp_prefix check

Perform check for set prefix early (if it's not given, tftp is disabled)
and drop redundant second check.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 7 insertions, 8 deletions

diff --git a/tftp.c b/tftp.c
index e9e2b91..ffb7f32 100644
--- a/tftp.c
+++ b/tftp.c
@@ -284,6 +284,12 @@ static void tftp_handle_rrq(struct tftp_t *tp, int pktlen)
 
     spt = &tftp_sessions[s];
 
+    /* unspecifed prefix means service disabled */
+    if (!tftp_prefix) {
+        tftp_send_error(spt, 2, "Access violation", tp);
+        return;
+    }
+
     src = tp->x.tp_buf;
     dst = spt->filename;
     n = pktlen - ((uint8_t *)&tp->x.tp_buf[0] - (uint8_t *)tp);
@@ -329,13 +335,6 @@ static void tftp_handle_rrq(struct tftp_t *tp, int pktlen)
         return;
     }
 
-    /* only allow exported prefixes */
-
-    if (!tftp_prefix) {
-        tftp_send_error(spt, 2, "Access violation", tp);
-        return;
-    }
-
     /* check if the file exists */
 
     if (tftp_read_data(spt, 0, spt->filename, 0) < 0) {
@@ -366,7 +365,7 @@ static void tftp_handle_rrq(struct tftp_t *tp, int pktlen)
             int tsize = atoi(value);
             struct stat stat_p;
 
-            if (tsize == 0 && tftp_prefix) {
+            if (tsize == 0) {
                 char buffer[1024];
                 int len;