Hi Alvin,
On 10/2/25 11:43 AM, Alvin Šipraga wrote:
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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 <[email protected]>
---
---
configs/gurnard_defconfig | 1 -
doc/usage/cmd/tftpput.rst | 8 ++------
net/Kconfig | 18 ------------------
net/tftp.c | 3 +--
4 files changed, 3 insertions(+), 27 deletions(-)
diff --git a/configs/gurnard_defconfig b/configs/gurnard_defconfig
index
bde531a6003a2d7167767b3f509876137c7da1a8..85643f249aed65071005a157658c3dc11f44c619
100644
--- a/configs/gurnard_defconfig
+++ b/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
diff --git a/doc/usage/cmd/tftpput.rst b/doc/usage/cmd/tftpput.rst
index
351c9faa38b9d8357c0e200d8cebd1f90344e0a6..2bcb3032cb2444926da28454eefdb2b128a7389f
100644
--- a/doc/usage/cmd/tftpput.rst
+++ b/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 source port and the environment variable *tftpdstp* can be used to set
-the destination port.
+The environment variable *tftpsrcp* can be used to set the source port and the
+environment variable *tftpdstp* can be used to set 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.
diff --git a/net/Kconfig b/net/Kconfig
index
40ec6bbce7614afde5a2a9f90d431f19a3654a41..7ba64d43b398415825921e7b61dc4c81e986618a
100644
--- a/net/Kconfig
+++ b/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
diff --git a/net/tftp.c b/net/tftp.c
index
1ca9a5ea7cf6bac562006e2506ebcb17996a8c36..1760877107faef57107cb04c484157750ff63602
100644
--- a/net/tftp.c
+++ b/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
+
The only worry I have with this patch is the security implications of
that. Indeed, if I manage to get access to the host (root not required)
where the TFTP server is running on port 69 AND the environment of the
board, I could set tftpdstp to point to the TFTP server I (an attacker)
just started on a non-privileged port.
On another unrelated note, I'm wondering if we shouldn't make the ports
(tftp_remote_port and tftp_our_port) u16 as that's the max allowed on
Unix as far as I know.
This would allow to use env_get_ulong() here, e.g.
tftp_remote_port = env_get_ulong("tftpdstp", 10, WELL_KNOWN_PORT);
tftp_our_port = env_get_ulong("tftpsrcp", 10, 1024 + (get_timer(0) % 3072));
But that would only make sense in a separate patch.
Cheers,
Quentin
