[PATCH] net/netcat: add netcat over tcp support
Heinrich Schuchardt
xypron.glpk at gmx.de
Wed Jan 1 10:44:15 CET 2025
On 1/1/25 04:33, Mikhail Kshevetskiy wrote:
> This patch adds downloading/uploading of data with netcat utility.
> Client/server modes are supported both.
>
> This patch is also an example of using new tcp api for legacy stack.
>
> How to test:
> ============
> netcat-openbsd=1.219-1 from debian were used for a tests
>
> a) Load data from remote host.
> * U-Boot listen on tcp port 3456
> * PC connects
>
> u-boot: netcat load ${loadaddr} 3456
> PC: netcat -q1 ${UBOOT_IP} 3456 < image.itb
>
> b) Load data from remote host.
> * PC listen on tcp port 3456
> * U-Boot connects
>
> PC: netcat -q1 -l -p 3456 < image.itb
> u-boot: netcat load ${loadaddr} ${PC_IP}:3456
>
> c) Save data to remote host
> * U-Boot listen on tcp port 3456
> * PC connects
>
> u-boot: netcat save ${loadaddr} ${data_size_in_hex} 3456
> PC: netcat -w1 ${UBOOT_IP} 3456 >image.itb
>
> d) Save data to remote host
> * PC listen on tcp port 3456
> * U-Boot connects
>
> PC: netcat -w1 -l -p 3456 >image.itb
> u-boot: netcat save ${loadaddr} ${data_size_in_hex} ${PC_IP}:3456
>
> Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy at iopsys.eu>
> Reviewed-by: Simon Glass <sjg at chromium.org>
> ---
> cmd/Kconfig | 10 +++
> cmd/net.c | 35 ++++++--
> include/net-legacy.h | 2 +-
> include/net/netcat.h | 20 +++++
> net/Makefile | 1 +
> net/net.c | 9 ++
> net/netcat.c | 194 +++++++++++++++++++++++++++++++++++++++++++
> 7 files changed, 265 insertions(+), 6 deletions(-)
> create mode 100644 include/net/netcat.h
> create mode 100644 net/netcat.c
>
> diff --git a/cmd/Kconfig b/cmd/Kconfig
> index 93efeaec6f4..e37e50a18b5 100644
> --- a/cmd/Kconfig
> +++ b/cmd/Kconfig
> @@ -2091,6 +2091,16 @@ config CMD_DNS
> help
> Lookup the IP of a hostname
>
> +config CMD_NETCAT
> + bool "netcat"
> + select PROT_TCP
Thank you for your patch which looks like a useful addition to U-Boot.
Here you make the netcat command depend on CMD_NET. This dependency
seems unnecessary at least for the lwIP case.
> + help
> + netcat is a simple command to load/store kernel, or other files,
> + using well-known netcat (nc) utility. Unlike classic netcat utility
> + this command supports TCP-based data transfer only, thus no data
> + will be lost or reordered. Any netcat implementation should work,
> + but openbsd one was tested only.
> +
> config CMD_MII
> bool "mii"
> imply CMD_MDIO
> diff --git a/cmd/net.c b/cmd/net.c
> index 79525f73a51..d7a5025f940 100644
> --- a/cmd/net.c
> +++ b/cmd/net.c
> @@ -208,6 +208,29 @@ U_BOOT_CMD(
> );
> #endif
>
> +#if defined(CONFIG_CMD_NETCAT)
> +static int do_netcat_load(struct cmd_tbl *cmdtp, int flag, int argc,
> + char *const argv[])
> +{
> + return netboot_common(NETCAT_LOAD, cmdtp, argc, argv);
> +}
> +
> +static int do_netcat_save(struct cmd_tbl *cmdtp, int flag, int argc,
> + char *const argv[])
> +{
> + return netboot_common(NETCAT_SAVE, cmdtp, argc, argv);
> +}
> +
> +U_BOOT_LONGHELP(netcat,
> + "load [loadAddress] [[hostIPaddr:]port]\n"
> + "save Address Size [[hostIPaddr:]port]");
> +
> +U_BOOT_CMD_WITH_SUBCMDS(netcat,
> + "load/store data over plain TCP via netcat utility", netcat_help_text,
> + U_BOOT_SUBCMD_MKENT(load, 3, 0, do_netcat_load),
> + U_BOOT_SUBCMD_MKENT(save, 4, 0, do_netcat_save));
> +#endif
> +
> static void netboot_update_env(void)
> {
> char tmp[46];
> @@ -325,16 +348,17 @@ static int parse_args(enum proto_t proto, int argc, char *const argv[])
>
> switch (argc) {
> case 1:
> - if (IS_ENABLED(CONFIG_CMD_TFTPPUT) && proto == TFTPPUT)
> + if ((IS_ENABLED(CONFIG_CMD_TFTPPUT) && proto == TFTPPUT) ||
> + (IS_ENABLED(CONFIG_CMD_NETCAT) && proto == NETCAT_SAVE))
> return 1;
> -
> /* refresh bootfile name from env */
> copy_filename(net_boot_file_name, env_get("bootfile"),
> sizeof(net_boot_file_name));
> break;
>
> case 2:
> - if (IS_ENABLED(CONFIG_CMD_TFTPPUT) && proto == TFTPPUT)
> + if ((IS_ENABLED(CONFIG_CMD_TFTPPUT) && proto == TFTPPUT) ||
> + (IS_ENABLED(CONFIG_CMD_NETCAT) && proto == NETCAT_SAVE))
> return 1;
> /*
> * Only one arg - accept two forms:
> @@ -356,7 +380,8 @@ static int parse_args(enum proto_t proto, int argc, char *const argv[])
> break;
>
> case 3:
> - if (IS_ENABLED(CONFIG_CMD_TFTPPUT) && proto == TFTPPUT) {
> + if ((IS_ENABLED(CONFIG_CMD_TFTPPUT) && proto == TFTPPUT) ||
> + (IS_ENABLED(CONFIG_CMD_NETCAT) && proto == NETCAT_SAVE)) {
> if (parse_addr_size(argv))
> return 1;
> } else {
> @@ -367,7 +392,7 @@ static int parse_args(enum proto_t proto, int argc, char *const argv[])
> }
> break;
>
> -#ifdef CONFIG_CMD_TFTPPUT
> +#if defined(CONFIG_CMD_TFTPPUT) || defined(CONFIG_CMD_NETCAT)
> case 4:
> if (parse_addr_size(argv))
> return 1;
> diff --git a/include/net-legacy.h b/include/net-legacy.h
> index bc0f0cde9fe..84a4beb9ec1 100644
> --- a/include/net-legacy.h
> +++ b/include/net-legacy.h
> @@ -305,7 +305,7 @@ extern int net_restart_wrap; /* Tried all network devices */
> enum proto_t {
> BOOTP, RARP, ARP, TFTPGET, DHCP, DHCP6, PING, PING6, DNS, NFS, CDP,
> NETCONS, SNTP, TFTPSRV, TFTPPUT, LINKLOCAL, FASTBOOT_UDP, FASTBOOT_TCP,
> - WOL, UDP, NCSI, WGET, RS
> + WOL, UDP, NCSI, WGET, NETCAT_LOAD, NETCAT_SAVE, RS
> };
>
> /* Indicates whether the file name was specified on the command line */
> diff --git a/include/net/netcat.h b/include/net/netcat.h
> new file mode 100644
> index 00000000000..d8e09aaaa55
> --- /dev/null
> +++ b/include/net/netcat.h
> @@ -0,0 +1,20 @@
> +/* SPDX-License-Identifier: BSD-2-Clause
According to doc/develop/sending_patches.rst all new code should use the
GPL-2.0-or-later license.
> + *
> + * netcat include file
> + * Copyright (C) 2024 IOPSYS Software Solutions AB
> + * Author: Mikhail Kshevetskiy <mikhail.kshevetskiy at iopsys.eu>
> + */
> +#ifndef __NET_NETCAT_TCP_H__
> +#define __NET_NETCAT_TCP_H__
> +
> +/**
> + * netcat_load_start() - begin netcat in loading mode
> + */
> +void netcat_load_start(void);
> +
> +/**
> + * netcat_save_start() - begin netcat in data saving mode
> + */
> +void netcat_save_start(void);
> +
> +#endif /* __NET_NETCAT_TCP_H__ */
> diff --git a/net/Makefile b/net/Makefile
> index 7c917b318c0..bc5f2f123be 100644
> --- a/net/Makefile
> +++ b/net/Makefile
> @@ -30,6 +30,7 @@ obj-$(CONFIG_CMD_WOL) += wol.o
> obj-$(CONFIG_PROT_UDP) += udp.o
> obj-$(CONFIG_PROT_TCP) += tcp.o
> obj-$(CONFIG_WGET) += wget.o
> +obj-$(CONFIG_CMD_NETCAT) += netcat.o
>
> # Disable this warning as it is triggered by:
> # sprintf(buf, index ? "foo%d" : "foo", index)
> diff --git a/net/net.c b/net/net.c
> index 1828f1cca36..595bffdc532 100644
> --- a/net/net.c
> +++ b/net/net.c
> @@ -103,6 +103,7 @@
> #include <net/fastboot_udp.h>
> #include <net/fastboot_tcp.h>
> #include <net/ncsi.h>
> +#include <net/netcat.h>
> #if defined(CONFIG_CMD_PCAP)
> #include <net/pcap.h>
> #endif
> @@ -572,6 +573,14 @@ restart:
> wget_start();
> break;
> #endif
> +#if defined(CONFIG_CMD_NETCAT)
> + case NETCAT_LOAD:
> + netcat_load_start();
> + break;
> + case NETCAT_SAVE:
> + netcat_save_start();
> + break;
> +#endif
> #if defined(CONFIG_CMD_CDP)
> case CDP:
> cdp_start();
> diff --git a/net/netcat.c b/net/netcat.c
> new file mode 100644
> index 00000000000..47dbebe5ae2
> --- /dev/null
> +++ b/net/netcat.c
> @@ -0,0 +1,194 @@
> +// SPDX-License-Identifier: GPL-2.0
According to doc/develop/sending_patches.rst all new code should use the
GPL-2.0-or-later license.
> +/*
> + * netcat support driver
> + * Copyright (C) 2024 IOPSYS Software Solutions AB
> + * Author: Mikhail Kshevetskiy <mikhail.kshevetskiy at iopsys.eu>
> + */
> +
> +#include <command.h>
> +#include <display_options.h>
> +#include <env.h>
> +#include <image.h>
> +#include <mapmem.h>
> +#include <net.h>
> +#include <net/tcp.h>
> +#include <net/netcat.h>
> +
> +#define HASHES_PER_LINE 65
> +#define MARKER_STEP 10
> +
> +static struct in_addr server_ip;
> +static u16 server_port;
> +static u16 local_port;
> +static int listen;
> +static int reading;
> +static int marker, marks_in_line;
> +static enum net_loop_state netcat_loop_state;
> +
Please, describe all functions in Sphinx style. Cf.
https://docs.kernel.org/doc-guide/kernel-doc.html#function-documentation
> +static void show_block_marker(int packets)
> +{
> + for (; marker + MARKER_STEP <= packets; marker += MARKER_STEP) {
> + marks_in_line++;
> + putc('#');
> + if (marks_in_line == HASHES_PER_LINE) {
> + marks_in_line = 0;
> + puts("\n");
> + }
> + }
> +}
> +
> +static void tcp_stream_on_closed(struct tcp_stream *tcp)
> +{
> + if (tcp->status != TCP_ERR_OK)
> + netcat_loop_state = NETLOOP_FAIL;
> +
> + /*
> + * The status line will be shown after the download/upload
> + * progress (see show_block_marker() function). This progress
> + * generally have no final "\n", so jump to new line before
> + * output the status
> + */
> + if (netcat_loop_state != NETLOOP_SUCCESS) {
> + net_boot_file_size = 0;
> + printf("\nnetcat: Transfer Fail, TCP status - %d\n", tcp->status);
> + } else {
> + env_set_hex("filesize", net_boot_file_size);
> + printf("\nPackets %s %d, Transfer Successful\n",
> + reading ? "received" : "transmitted",
> + reading ? tcp->rx_packets : tcp->tx_packets);
> + }
> + net_set_state(netcat_loop_state);
> +}
> +
> +static void tcp_stream_on_rcv_nxt_update(struct tcp_stream *tcp, u32 rx_bytes)
> +{
> + net_boot_file_size = rx_bytes;
> + show_block_marker(tcp->rx_packets);
> +}
> +
> +static void tcp_stream_on_snd_una_update(struct tcp_stream *tcp, u32 tx_bytes)
> +{
> + show_block_marker(tcp->tx_packets);
> + if (tx_bytes == image_save_size)
> + tcp_stream_close(tcp);
> +}
> +
> +static void tcp_stream_on_established(struct tcp_stream *tcp)
> +{
> + netcat_loop_state = NETLOOP_SUCCESS;
> +}
> +
> +static int tcp_stream_rx(struct tcp_stream *tcp, u32 rx_offs, void *buf, int len)
> +{
> + void *ptr;
> +
> + ptr = map_sysmem(image_load_addr + rx_offs, len);
> + memcpy(ptr, buf, len);
> + unmap_sysmem(ptr);
> +
> + return len;
> +}
> +
> +static int tcp_stream_tx(struct tcp_stream *tcp, u32 tx_offs, void *buf, int maxlen)
> +{
> + void *ptr;
> +
> + if (tx_offs + maxlen > image_save_size)
> + maxlen = image_save_size - tx_offs;
> + if (!maxlen)
> + return 0;
> +
> + ptr = map_sysmem(image_save_addr + tx_offs, maxlen);
> + memcpy(buf, ptr, maxlen);
> + unmap_sysmem(ptr);
> +
> + return maxlen;
> +}
> +
> +/*
> + * This function will be called on new connections (incoming or outgoing)
> + * It MUST:
> + * -- setup required tcp_stream callbacks (if connection will be accepted)
> + * -- return a connection verdict:
> + * 0: discard connection
> + * 1: accept connection
Please, use a Sphinx style function description.
Best regards
Heinrich
> + */
> +static int tcp_stream_on_create(struct tcp_stream *tcp)
> +{
> + if (listen) {
> + /*
> + * We are listening for incoming connections.
> + * Accept connections to netcat listen port only.
> + */
> + if (tcp->lport != local_port)
> + return 0;
> + } else {
> + /*
> + * We are connecting to remote host.
> + * Check remote IP:port to make sure that this is our connection
> + */
> + if (tcp->rhost.s_addr != server_ip.s_addr ||
> + tcp->rport != server_port)
> + return 0;
> + }
> +
> + netcat_loop_state = NETLOOP_FAIL;
> + net_boot_file_size = 0;
> + marker = 0;
> + marks_in_line = 0;
> +
> + tcp->on_closed = tcp_stream_on_closed;
> + tcp->on_established = tcp_stream_on_established;
> + if (reading) {
> + tcp->on_rcv_nxt_update = tcp_stream_on_rcv_nxt_update;
> + tcp->rx = tcp_stream_rx;
> + } else {
> + tcp->on_snd_una_update = tcp_stream_on_snd_una_update;
> + tcp->tx = tcp_stream_tx;
> + }
> +
> + return 1;
> +}
> +
> +static void netcat_start(void)
> +{
> + struct tcp_stream *tcp;
> +
> + memset(net_server_ethaddr, 0, 6);
> + tcp_stream_set_on_create_handler(tcp_stream_on_create);
> +
> + if (!strchr(net_boot_file_name, ':')) {
> + listen = 1;
> + printf("Listening on port %s...\n", net_boot_file_name);
> +
> + local_port = dectoul(net_boot_file_name, NULL);
> + } else {
> + listen = 0;
> + printf("Connecting to %s...\n", net_boot_file_name);
> +
> + server_ip = string_to_ip(net_boot_file_name);
> + server_port = dectoul(strchr(net_boot_file_name, ':') + 1, NULL);
> +
> + tcp = tcp_stream_connect(server_ip, server_port);
> + if (!tcp) {
> + printf("No free tcp streams\n");
> + net_set_state(NETLOOP_FAIL);
> + return;
> + }
> + tcp_stream_put(tcp);
> + }
> +}
> +
> +void netcat_load_start(void)
> +{
> + reading = 1;
> +
> + return netcat_start();
> +}
> +
> +void netcat_save_start(void)
> +{
> + reading = 0;
> +
> + return netcat_start();
> +}
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