Change -tftp option to take a root directory, by Anthony Liguori.


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@2441 c046a42c-6fe2-441c-8c8c-71466251a162
diff --git a/slirp/tftp.c b/slirp/tftp.c
index b3947eb..96d00e6 100644
--- a/slirp/tftp.c
+++ b/slirp/tftp.c
@@ -102,8 +102,15 @@
 {
   int fd;
   int bytes_read = 0;
+  char buffer[1024];
+  int n;
 
-  fd = open(spt->filename, O_RDONLY | O_BINARY);
+  n = snprintf(buffer, sizeof(buffer), "%s/%s",
+	       tftp_prefix, spt->filename);
+  if (n >= sizeof(buffer))
+    return -1;
+
+  fd = open(buffer, O_RDONLY | O_BINARY);
 
   if (fd < 0) {
     return -1;
@@ -325,8 +332,7 @@
 
   /* only allow exported prefixes */
 
-  if (!tftp_prefix
-      || (strncmp(spt->filename, tftp_prefix, strlen(tftp_prefix)) != 0)) {
+  if (!tftp_prefix) {
       tftp_send_error(spt, 2, "Access violation", tp);
       return;
   }