tftp: make TFTP ports unconditionally configurable

A few lines of code being guarded by the CONFIG_TFTP_PORT option seems
an unnecessary restriction on the TFTP support provided by a vanilla
U-Boot image. In cases where the TFTP server cannot run as superuser -
and hence cannot run on the well-known port 69 - this quirk incurs a
full reconfiguration and rebuild of the bootloader only in order to
select the appropriate destination port.

Remove the CONFIG_TFTP_PORT option entirely and make the tftpdstp and
tftpsrcp variables always have an effect. Their being unset will mean
that U-Boot behaves the same as if CONFIG_TFTP_PORT was unset. Update
the documentation accordingly. And fix up the single board which was
originally enabling this option.

Signed-off-by: Alvin Šipraga <alvin@pqrs.dk>
Reviewed-by: Quentin Schulz <quentin.schulz@cherry.de>

configs/gurnard_defconfig

@@ -42,7 +42,6 @@ CONFIG_ENV_OVERWRITE=y
 CONFIG_ENV_IS_IN_NAND=y
 CONFIG_ENV_RELOC_GD_ENV_ADDR=y
 CONFIG_NET_RETRY_COUNT=20
-CONFIG_TFTP_PORT=y
 CONFIG_TFTP_TSIZE=y
 CONFIG_AT91_GPIO=y
 CONFIG_GENERIC_ATMEL_MCI=y

doc/usage/cmd/tftpput.rst

@@ -19,9 +19,8 @@ Description
 The tftpput command is used to transfer a file to a TFTP server.
 
 By default the destination port is 69 and the source port is pseudo-random.
-If CONFIG_TFTP_PORT=y, the environment variable *tftpsrcp* can be used to set
+The environment variable *tftpsrcp* can be used to set the source port and the
-the source port and the environment variable *tftpdstp* can be used to set
+environment variable *tftpdstp* can be used to set the destination port.
-the destination port.
 
 address
     memory address where the data starts
@@ -75,9 +74,6 @@ The command is only available if CONFIG_CMD_TFTPPUT=y.
 CONFIG_TFTP_BLOCKSIZE defines the size of the TFTP blocks sent. It defaults
 to 1468 matching an ethernet MTU of 1500.
 
-If CONFIG_TFTP_PORT=y, the environment variables *tftpsrcp* and *tftpdstp* can
-be used to set the source and the destination ports.
-
 CONFIG_TFTP_WINDOWSIZE can be used to set the TFTP window size of transmits
 after which an ACK response is required. The window size defaults to 1.
 

net/Kconfig

@@ -60,24 +60,6 @@ config SYS_FAULT_ECHO_LINK_DOWN
 	  this option is active, then CONFIG_SYS_FAULT_MII_ADDR also needs to
 	  be configured.
 
-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

net/tftp.c

@@ -926,14 +926,13 @@ void tftp_start(enum proto_t protocol)
 	/* Use a pseudo-random port unless a specific port is set */
 	tftp_our_port = 1024 + (get_timer(0) % 3072);
 
-#ifdef CONFIG_TFTP_PORT
 	ep = env_get("tftpdstp");
 	if (ep != NULL)
 		tftp_remote_port = simple_strtol(ep, NULL, 10);
 	ep = env_get("tftpsrcp");
 	if (ep != NULL)
 		tftp_our_port = simple_strtol(ep, NULL, 10);
-#endif
+
 	tftp_cur_block = 0;
 	tftp_windowsize = 1;
 	tftp_last_nack = 0;