net: Consolidate the parsing of bootfile

The same basic parsing was implemented in tftp and nfs, so add a helper
function to do the work once.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>

include/net.h

@@ -842,6 +842,17 @@ void copy_filename(char *dst, const char *src, int size);
 /* check if serverip is specified in filename from the command line */
 int is_serverip_in_cmd(void);
 
+/**
+ * net_parse_bootfile - Parse the bootfile env var / cmd line param
+ *
+ * @param ipaddr - a pointer to the ipaddr to populate if included in bootfile
+ * @param filename - a pointer to the string to save the filename part
+ * @param max_len - The longest - 1 that the filename part can be
+ *
+ * return 1 if parsed, 0 if bootfile is empty
+ */
+int net_parse_bootfile(struct in_addr *ipaddr, char *filename, int max_len);
+
 /* get a random source port */
 unsigned int random_port(void);