Convert CONFIG_TFTP_PORT to Kconfig

This converts the following to Kconfig:
   CONFIG_TFTP_PORT

Cc: Ramon Fried <rfried.dev@gmail.com>
Signed-off-by: Tom Rini <trini@konsulko.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/net/Kconfig b/net/Kconfig
index 650551606d..af6856f7fc 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -83,6 +83,24 @@ config TFTP_BLOCKSIZE
 	  almost-MTU block sizes.
 	  You can also activate CONFIG_IP_DEFRAG to set a larger block.
 
+config TFTP_PORT
+	bool "Set TFTP UDP source/destination ports via the environment"
+	help
+	  If this is defined, the environment variable tftpsrcp is used to
+	  supply the TFTP UDP source port value.  If tftpsrcp isn't defined,
+	  the normal pseudo-random port number generator is used.
+
+	  Also, the environment variable tftpdstp is used to supply the TFTP
+	  UDP destination port value.  If tftpdstp isn't defined, the normal
+	  port 69 is used.
+
+	  The purpose for tftpsrcp is to allow a TFTP server to blindly start
+	  the TFTP transfer using the pre-configured target IP address and UDP
+	  port. This has the effect of "punching through" the (Windows XP)
+	  firewall, allowing the remainder of the TFTP transfer to proceed
+	  normally.  A better solution is to properly configure the firewall,
+	  but sometimes that is not allowed.
+
 config TFTP_WINDOWSIZE
 	int "TFTP window size"
 	default 1