[PATCH v2] net: lwip: add tftpsrv command
James Hilliard
james.hilliard1 at gmail.com
Sat Jun 27 01:27:08 CEST 2026
The legacy network stack supports tftpsrv, which listens for an
incoming TFTP write request and receives the first file into memory.
Despite the old command help wording, the command returns after
receiving the file and does not boot it automatically.
The lwIP stack already builds the lwIP TFTP application, but only wires
it up for client-side tftpboot. Add a lwIP tftpsrv command and
implement the server path with tftp_init_server(). Reuse the existing
lwIP TFTP write callback and memory copy path so LMB checks, progress
output, filesize/fileaddr updates and EFI bootdev handling stay
consistent with tftpboot.
Track receive timeout and write-failure state around the lwIP callbacks
so a stalled or rejected receive is not reported as a successful close.
Move CMD_TFTPSRV out of the legacy-only Kconfig block so it can be
enabled with either network stack. Update the command help text and add
usage documentation for the receive-only behavior.
Add pytest coverage for tftpsrv using a generated host file and curl's
TFTP upload support. Enable the command in qemu_arm64_lwip_defconfig so
the test can be run with the existing lwIP QEMU build when the boardenv
provides env__net_tftpsrv_file.
Signed-off-by: James Hilliard <james.hilliard1 at gmail.com>
---
Changes v1 -> v2:
- Add tftpsrv usage documentation (suggested by Quentin Schulz)
- Add tftpsrv pytest coverage (suggested by Quentin Schulz)
- Enable CMD_TFTPSRV in qemu_arm64_lwip_defconfig
- Allow tftpsrv pytest coverage to use an explicit upload URL
- Keep tftpsrv pytest coverage gated by env__net_tftpsrv_file
- Clarify that tftpsrv returns after receiving instead of booting
- Update legacy and lwIP command help text for receive-only behavior
---
cmd/Kconfig | 14 ++-
cmd/lwip/Makefile | 1 +
cmd/lwip/tftpsrv.c | 11 ++
cmd/net.c | 4 +-
configs/qemu_arm64_lwip_defconfig | 1 +
doc/usage/cmd/tftpsrv.rst | 73 ++++++++++++
include/net-lwip.h | 1 +
net/lwip/tftp.c | 181 +++++++++++++++++++++++++++++-
test/py/tests/test_net.py | 94 ++++++++++++++++
9 files changed, 367 insertions(+), 13 deletions(-)
create mode 100644 cmd/lwip/tftpsrv.c
create mode 100644 doc/usage/cmd/tftpsrv.rst
diff --git a/cmd/Kconfig b/cmd/Kconfig
index c71c6824a19..303acf8aa31 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -2127,12 +2127,6 @@ config CMD_TFTPPUT
help
TFTP put command, for uploading files to a server
-config CMD_TFTPSRV
- bool "tftpsrv"
- depends on CMD_TFTPBOOT
- help
- Act as a TFTP server and boot the first received file
-
config NET_TFTP_VARS
bool "Control TFTP timeout and count through environment"
depends on CMD_TFTPBOOT
@@ -2279,6 +2273,14 @@ config CMD_TFTPBOOT
help
tftpboot - load file via network using TFTP protocol
+config CMD_TFTPSRV
+ bool "tftpsrv"
+ depends on CMD_TFTPBOOT
+ help
+ Act as a TFTP server and receive the first incoming file into
+ memory. The command returns successfully after the transfer so
+ boot scripts can boot the received image from the load address.
+
config CMD_WGET
bool "wget"
default y if SANDBOX || ARCH_QEMU
diff --git a/cmd/lwip/Makefile b/cmd/lwip/Makefile
index 90df1f5511c..245683a9672 100644
--- a/cmd/lwip/Makefile
+++ b/cmd/lwip/Makefile
@@ -4,4 +4,5 @@ obj-$(CONFIG_CMD_NFS) += nfs.o
obj-$(CONFIG_CMD_PING) += ping.o
obj-$(CONFIG_CMD_SNTP) += sntp.o
obj-$(CONFIG_CMD_TFTPBOOT) += tftp.o
+obj-$(CONFIG_CMD_TFTPSRV) += tftpsrv.o
obj-$(CONFIG_CMD_WGET) += wget.o
diff --git a/cmd/lwip/tftpsrv.c b/cmd/lwip/tftpsrv.c
new file mode 100644
index 00000000000..6370c900489
--- /dev/null
+++ b/cmd/lwip/tftpsrv.c
@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <command.h>
+#include <net.h>
+
+U_BOOT_CMD(tftpsrv, 2, 1, do_tftpsrv,
+ "act as a TFTP server and receive the first file",
+ "[loadAddress]\n"
+ "Listen for an incoming TFTP transfer and receive a file into memory.\n"
+ "The transfer is aborted if a transfer has not been started after\n"
+ "about 50 seconds or if Ctrl-C is pressed.");
diff --git a/cmd/net.c b/cmd/net.c
index f6f556f36ae..0f0b2386d87 100644
--- a/cmd/net.c
+++ b/cmd/net.c
@@ -89,9 +89,9 @@ static int do_tftpsrv(struct cmd_tbl *cmdtp, int flag, int argc,
U_BOOT_CMD(
tftpsrv, 2, 1, do_tftpsrv,
- "act as a TFTP server and boot the first received file",
+ "act as a TFTP server and receive the first file",
"[loadAddress]\n"
- "Listen for an incoming TFTP transfer, receive a file and boot it.\n"
+ "Listen for an incoming TFTP transfer and receive a file into memory.\n"
"The transfer is aborted if a transfer has not been started after\n"
"about 50 seconds or if Ctrl-C is pressed."
);
diff --git a/configs/qemu_arm64_lwip_defconfig b/configs/qemu_arm64_lwip_defconfig
index a974970c3d3..06ed5a131db 100644
--- a/configs/qemu_arm64_lwip_defconfig
+++ b/configs/qemu_arm64_lwip_defconfig
@@ -7,6 +7,7 @@ CONFIG_NET_LWIP=y
CONFIG_CMD_DNS=y
CONFIG_CMD_NFS=y
CONFIG_CMD_SNTP=y
+CONFIG_CMD_TFTPSRV=y
CONFIG_CMD_WGET=y
CONFIG_EFI_HTTP_BOOT=y
CONFIG_WGET_HTTPS=y
diff --git a/doc/usage/cmd/tftpsrv.rst b/doc/usage/cmd/tftpsrv.rst
new file mode 100644
index 00000000000..597a2f3a8bd
--- /dev/null
+++ b/doc/usage/cmd/tftpsrv.rst
@@ -0,0 +1,73 @@
+.. SPDX-License-Identifier: GPL-2.0+:
+
+.. index::
+ single: tftpsrv (command)
+
+tftpsrv command
+===============
+
+Synopsis
+--------
+
+::
+
+ tftpsrv [loadAddress]
+
+Description
+-----------
+
+The tftpsrv command listens for an incoming TFTP write request and receives
+the first transferred file into memory.
+
+loadAddress
+ memory address where the received file is stored. If not provided, the
+ address is taken from the *loadaddr* environment variable or the default
+ image load address.
+
+After a successful transfer, the *fileaddr* and *filesize* environment
+variables describe the received file. The command returns successfully after
+the transfer has completed. It does not boot the file automatically; boot
+scripts can use commands such as bootm, booti or bootefi to boot from the
+load address.
+
+The transfer is aborted if no transfer has started after about 50 seconds or
+if Ctrl-C is pressed.
+
+Example
+-------
+
+In the example the following steps are executed:
+
+* setup the board network address
+* receive a FIT image from a host
+* boot the received FIT image
+
+::
+
+ => setenv autoload no
+ => dhcp
+ BOOTP broadcast 1
+ DHCP client bound to address 192.168.1.40 (7 ms)
+ => tftpsrv $loadaddr
+ Using ethernet at 1c30000 device
+ Listening for TFTP transfer on 192.168.1.40
+ Load address: 0x42000000
+ Loading: #################################################################
+ 6.5 MiB/s
+ done
+ Bytes transferred = 1048576 (100000 hex)
+ => bootm $fileaddr
+
+On the host, send the file to the board while U-Boot is listening:
+
+::
+
+ $ curl --upload-file image.fit tftp://192.168.1.40/image.fit
+
+Configuration
+-------------
+
+The command is only available if CONFIG_CMD_TFTPSRV=y.
+
+The command is supported by both the legacy network stack and the lwIP network
+stack.
diff --git a/include/net-lwip.h b/include/net-lwip.h
index 20cb0992cce..571d8941ff0 100644
--- a/include/net-lwip.h
+++ b/include/net-lwip.h
@@ -52,6 +52,7 @@ bool wget_validate_uri(char *uri);
int do_dns(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]);
int do_nfs(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]);
+int do_tftpsrv(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]);
int do_wget(struct cmd_tbl *cmdtp, int flag, int argc, char * const argv[]);
#endif /* __NET_LWIP_H__ */
diff --git a/net/lwip/tftp.c b/net/lwip/tftp.c
index 7f3b28b8507..af25aabc973 100644
--- a/net/lwip/tftp.c
+++ b/net/lwip/tftp.c
@@ -11,6 +11,7 @@
#include <linux/delay.h>
#include <linux/kconfig.h>
#include <lwip/apps/tftp_client.h>
+#include <lwip/apps/tftp_server.h>
#include <lwip/timeouts.h>
#include <mapmem.h>
#include <net.h>
@@ -19,6 +20,8 @@
#define PROGRESS_PRINT_STEP_BYTES (10 * 1024)
/* Max time to wait for first data packet from server */
#define NO_RSP_TIMEOUT_MS 10000
+/* Max time to wait for an incoming TFTP write request */
+#define NO_WRQ_TIMEOUT_MS (TFTP_TIMEOUT_MSECS * TFTP_MAX_RETRIES)
enum done_state {
NOT_DONE = 0,
@@ -34,8 +37,27 @@ struct tftp_ctx {
ulong hash_count;
ulong start_time;
enum done_state done;
+ bool is_server;
+ bool wrq_accepted;
+ char fname[TFTP_MAX_FILENAME_LEN + 1];
};
+static struct tftp_ctx *tftpsrv_active_ctx;
+
+static void transfer_timeout(void *arg)
+{
+ struct tftp_ctx *ctx = (struct tftp_ctx *)arg;
+
+ printf("Timeout!\n");
+ ctx->done = FAILURE;
+}
+
+static void restart_transfer_timeout(struct tftp_ctx *ctx)
+{
+ sys_untimeout(transfer_timeout, ctx);
+ sys_timeout(TFTP_TIMEOUT_MSECS, transfer_timeout, ctx);
+}
+
/**
* store_block() - copy received data
*
@@ -71,7 +93,7 @@ static int store_block(struct tftp_ctx *ctx, void *src, u16_t len)
ctx->size += len;
ctx->block_count++;
- tftp_tsize = tftp_client_get_tsize();
+ tftp_tsize = ctx->is_server ? 0 : tftp_client_get_tsize();
if (tftp_tsize) {
pos = clamp(ctx->size, 0UL, tftp_tsize);
@@ -92,7 +114,20 @@ static int store_block(struct tftp_ctx *ctx, void *src, u16_t len)
static void *tftp_open(const char *fname, const char *mode, u8_t is_write)
{
- return NULL;
+ struct tftp_ctx *ctx = tftpsrv_active_ctx;
+
+ if (!IS_ENABLED(CONFIG_CMD_TFTPSRV) || !ctx || !is_write)
+ return NULL;
+
+ ctx->wrq_accepted = true;
+ ctx->start_time = get_timer(0);
+ snprintf(ctx->fname, sizeof(ctx->fname), "%s", fname);
+ restart_transfer_timeout(ctx);
+
+ printf("\nReceiving '%s' mode '%s'\n", fname, mode);
+ puts("Loading: ");
+
+ return ctx;
}
static void tftp_close(void *handle)
@@ -101,13 +136,15 @@ static void tftp_close(void *handle)
ulong tftp_tsize;
ulong elapsed;
+ sys_untimeout(transfer_timeout, ctx);
+
if (ctx->done == FAILURE || ctx->done == ABORTED) {
/* Closing after an error or Ctrl-C */
return;
}
ctx->done = SUCCESS;
- tftp_tsize = tftp_client_get_tsize();
+ tftp_tsize = ctx->is_server ? 0 : tftp_client_get_tsize();
if (tftp_tsize) {
/* Print hash marks for the last packet received */
while (ctx->hash_count < 49) {
@@ -142,9 +179,14 @@ static int tftp_write(void *handle, struct pbuf *p)
struct tftp_ctx *ctx = handle;
struct pbuf *q;
- for (q = p; q; q = q->next)
- if (store_block(ctx, q->payload, q->len) < 0)
+ for (q = p; q; q = q->next) {
+ if (store_block(ctx, q->payload, q->len) < 0) {
+ ctx->done = FAILURE;
return -1;
+ }
+ }
+
+ restart_transfer_timeout(ctx);
return 0;
}
@@ -204,6 +246,9 @@ static int tftp_loop(struct udevice *udev, ulong addr, char *fname,
ctx.block_count = 0;
ctx.hash_count = 0;
ctx.daddr = addr;
+ ctx.is_server = false;
+ ctx.wrq_accepted = false;
+ ctx.fname[0] = '\0';
printf("Using %s device\n", udev->name);
printf("TFTP from server %s; our IP address is %s\n",
@@ -258,6 +303,132 @@ static int tftp_loop(struct udevice *udev, ulong addr, char *fname,
return -1;
}
+static void no_request(void *arg)
+{
+ struct tftp_ctx *ctx = (struct tftp_ctx *)arg;
+
+ if (ctx->wrq_accepted)
+ return;
+
+ printf("Timeout!\n");
+ ctx->done = FAILURE;
+}
+
+static int tftpsrv_loop(struct udevice *udev, ulong addr)
+{
+ struct netif *netif;
+ struct tftp_ctx ctx;
+ const char *ipaddr;
+ err_t err;
+
+ if (addr == 0)
+ return -1;
+
+ ipaddr = env_get("ipaddr");
+ if (!ipaddr || !*ipaddr) {
+ log_err("error: ipaddr has to be set\n");
+ return -1;
+ }
+
+ netif = net_lwip_new_netif(udev);
+ if (!netif)
+ return -1;
+
+ memset(&ctx, 0, sizeof(ctx));
+ ctx.done = NOT_DONE;
+ ctx.daddr = addr;
+ ctx.is_server = true;
+
+ printf("Using %s device\n", udev->name);
+ printf("Listening for TFTP transfer on %s\n", ipaddr);
+ printf("Load address: 0x%lx\n", ctx.daddr);
+
+ tftpsrv_active_ctx = &ctx;
+ err = tftp_init_server(&tftp_context);
+ if (err != ERR_OK) {
+ log_err("tftp_init_server err: %d\n", err);
+ tftpsrv_active_ctx = NULL;
+ net_lwip_remove_netif(netif);
+ return -1;
+ }
+
+ ctx.start_time = get_timer(0);
+ sys_timeout(NO_WRQ_TIMEOUT_MS, no_request, &ctx);
+ while (!ctx.done) {
+ net_lwip_rx(udev, netif);
+ if (ctrlc()) {
+ printf("\nAbort\n");
+ ctx.done = ABORTED;
+ break;
+ }
+ }
+ sys_untimeout(no_request, (void *)&ctx);
+
+ tftp_cleanup();
+ tftpsrv_active_ctx = NULL;
+ net_lwip_remove_netif(netif);
+
+ if (ctx.done == SUCCESS) {
+ if (env_set_hex("fileaddr", addr)) {
+ log_err("fileaddr not updated\n");
+ return -1;
+ }
+ efi_set_bootdev("Net", "", ctx.fname, map_sysmem(addr, 0),
+ ctx.size);
+ return 0;
+ }
+
+ return -1;
+}
+
+int do_tftpsrv(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
+{
+ int ret = CMD_RET_SUCCESS;
+ char *end;
+ ulong laddr;
+ ulong addr;
+
+ if (!IS_ENABLED(CONFIG_CMD_TFTPSRV))
+ return CMD_RET_FAILURE;
+
+ laddr = env_get_ulong("loadaddr", 16, image_load_addr);
+
+ switch (argc) {
+ case 1:
+ break;
+ case 2:
+ addr = hextoul(argv[1], &end);
+ if (end == argv[1] || *end) {
+ ret = CMD_RET_USAGE;
+ goto out;
+ }
+ laddr = addr;
+ break;
+ default:
+ ret = CMD_RET_USAGE;
+ goto out;
+ }
+
+ if (!laddr) {
+ log_err("error: no load address\n");
+ ret = CMD_RET_FAILURE;
+ goto out;
+ }
+
+ if (net_lwip_eth_start() < 0) {
+ ret = CMD_RET_FAILURE;
+ goto out;
+ }
+
+ if (tftpsrv_loop(eth_get_dev(), laddr) < 0)
+ ret = CMD_RET_FAILURE;
+ else
+ image_load_addr = laddr;
+
+out:
+ return ret;
+}
+
int do_tftpb(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
{
int ret = CMD_RET_SUCCESS;
diff --git a/test/py/tests/test_net.py b/test/py/tests/test_net.py
index 27cdd73fd49..a2007c2fd3a 100644
--- a/test/py/tests/test_net.py
+++ b/test/py/tests/test_net.py
@@ -59,6 +59,19 @@ For example:
'fnu': 'ubtest-upload.bin',
}
+ # Details regarding a file that may be written to U-Boot using the tftpsrv
+ # command. This variable may be omitted or set to None if tftpsrv testing
+ # is not possible or desired. The test uses host-side curl TFTP support to
+ # upload a generated file to U-Boot. The optional tftpsrv_url entry may be
+ # used when the host must use a forwarded address instead of U-Boot's
+ # ipaddr value.
+ env__net_tftpsrv_file = {
+ 'fn': 'ubtest-tftpsrv.bin',
+ 'addr': 0x10000000,
+ 'size': 4096,
+ 'timeout': 50000,
+ }
+
# Details regarding a file that may be read from a NFS server. This variable
# may be omitted or set to None if NFS testing is not possible or desired.
env__net_nfs_readable_file = {
@@ -89,6 +102,8 @@ import utils
import uuid
import datetime
import re
+import tempfile
+import zlib
net_set_up = False
net6_set_up = False
@@ -460,3 +475,82 @@ def test_net_tftpput(ubman):
output = ubman.run_command("crc32 $fileaddr $filesize")
assert expected_tftpb_crc in output
+
+
+ at pytest.mark.buildconfigspec("cmd_crc32")
+ at pytest.mark.buildconfigspec("cmd_tftpsrv")
+ at pytest.mark.requiredtool("curl")
+def test_net_tftpsrv(ubman):
+ """Test the tftpsrv command.
+
+ A file is generated on the host, uploaded to U-Boot using TFTP and then
+ validated in U-Boot using its size and CRC32.
+
+ The details of the file to upload are provided by the boardenv_* file;
+ see the comment at the beginning of this file.
+ """
+
+ if not net_set_up:
+ pytest.skip("Network not initialized")
+
+ f = ubman.config.env.get("env__net_tftpsrv_file", None)
+ if not f:
+ pytest.skip("No tftpsrv file to write")
+
+ curl_version = utils.run_and_log(ubman, ["curl", "--version"])
+ if "tftp" not in curl_version.split():
+ pytest.skip("curl does not support TFTP")
+
+ addr = f.get("addr", None)
+ if not addr:
+ addr = utils.find_ram_base(ubman)
+
+ timeout = f.get("timeout", ubman.p.timeout)
+ timeout_secs = max(1, (timeout + 999) // 1000)
+ size = f.get("size", 4096)
+ fn = f.get("fn", "ubtest-tftpsrv.bin")
+ url = f.get("tftpsrv_url", None)
+ data = bytes([i % 251 for i in range(size)])
+ crc = "%08x" % (zlib.crc32(data) & 0xffffffff)
+
+ ip = ubman.run_command("echo $ipaddr").strip()
+ if not ip:
+ pytest.skip("No U-Boot IP address")
+ if not url:
+ url = "tftp://%s/%s" % (ip, fn)
+
+ with tempfile.NamedTemporaryFile() as tmp:
+ tmp.write(data)
+ tmp.flush()
+
+ done = False
+ with ubman.temporary_timeout(timeout):
+ try:
+ ubman.run_command("tftpsrv %x" % addr,
+ wait_for_prompt=False)
+ ubman.wait_for("Listening for TFTP transfer")
+ utils.run_and_log(
+ ubman,
+ [
+ "curl",
+ "--fail",
+ "--max-time",
+ str(timeout_secs),
+ "--upload-file",
+ tmp.name,
+ url,
+ ],
+ )
+ ubman.wait_for("Bytes transferred = %d" % size)
+ ubman.wait_for(ubman.prompt)
+ done = True
+ finally:
+ if not done:
+ ubman.ctrlc()
+ ubman.drain_console()
+
+ output = ubman.run_command("echo $filesize")
+ assert "%x" % size in output
+
+ output = ubman.run_command("crc32 $fileaddr $filesize")
+ assert crc in output
--
2.53.0
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