[PATCH v6 10/12] net/netcat: add netcat over tcp support

Mikhail Kshevetskiy mikhail.kshevetskiy at genexis.eu
Sun Sep 15 09:05:51 CEST 2024


On 12.09.2024 03:59, Simon Glass wrote:
> Hi Mikhail,
>
> On Mon, 9 Sept 2024 at 16:27, Mikhail Kshevetskiy
> <mikhail.kshevetskiy at iopsys.eu> wrote:
>> This patch adds downloading/uploading of data with netcat.
>> Client/server mode both supported.
>>
>> 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>
>> ---
>>  cmd/Kconfig          |   7 ++
>>  cmd/net.c            |  34 ++++++--
>>  include/net.h        |   2 +-
>>  include/net/netcat.h |  20 +++++
>>  net/Makefile         |   1 +
>>  net/net.c            |   9 +++
>>  net/netcat.c         | 181 +++++++++++++++++++++++++++++++++++++++++++
>>  7 files changed, 248 insertions(+), 6 deletions(-)
>>  create mode 100644 include/net/netcat.h
>>  create mode 100644 net/netcat.c
> Reviewed-by: Simon Glass <sjg at chromium.org>

Can/should I add this "Reviewed-by" to the next patch version?

>
> nits below
>
>> diff --git a/cmd/Kconfig b/cmd/Kconfig
>> index 978f44eda42..abcd003f7f1 100644
>> --- a/cmd/Kconfig
>> +++ b/cmd/Kconfig
>> @@ -2007,6 +2007,13 @@ config CMD_WGET
>>           wget is a simple command to download kernel, or other files,
>>           from a http server over TCP.
>>
>> +config CMD_NETCAT
>> +       bool "netcat"
>> +       select PROT_TCP
>> +       help
>> +         netcat is a simple command to load/store kernel, or other files,
>> +         using netcat like manner over TCP.
> netcat-like
>
> Please add a reference to the protocol or the 'netcat' tool or both.
> Help must be at least 3 lines.

Netcat (https://en.wikipedia.org/wiki/Netcat)  uses plain TCP/UDP for
data delivery. In the TCP case, TCP by itself provides reliable,
ordered, and error-checked data delivery, so no additional protocols are
required.

Is it enough to write the following description?

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 53ce2bc5d0c..364139ec5b9 100644
>> --- a/cmd/net.c
>> +++ b/cmd/net.c
>> @@ -206,6 +206,28 @@ U_BOOT_CMD(
>>  );
>>  #endif
>>
>> +#if defined(CONFIG_CMD_NETCAT)
>> +static int do_netcat(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
>> +{
>> +       if (argc < 2)
>> +               return 1;
>> +
>> +       if (!strcmp(argv[1], "load"))
>> +               return netboot_common(NETCAT_LOAD, cmdtp, argc - 1, argv + 1);
>> +       else if (!strcmp(argv[1], "save"))
>> +               return netboot_common(NETCAT_SAVE, cmdtp, argc - 1, argv + 1);
>> +       else
>> +               return 1;
>> +}
>> +
> Needs longhelp
Could you explain? Usage examples?
>
>> +U_BOOT_CMD(
>> +       netcat,   5,      1,      do_netcat,
>> +       "load/store data via tcp netcat utility",
>> +       "load [loadAddress] [[hostIPaddr:]port]\n"
>> +       "save Address Size [[hostIPaddr:]port]\n"
>> +);
>> +#endif
>> +
>>  static void netboot_update_env(void)
>>  {
>>         char tmp[46];
>> @@ -323,16 +345,17 @@ 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:
>> @@ -354,7 +377,8 @@ 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 {
>> @@ -365,7 +389,7 @@ 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.h b/include/net.h
>> index b0ce13e0a9d..0af6493788a 100644
>> --- a/include/net.h
>> +++ b/include/net.h
>> @@ -515,7 +515,7 @@ 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
>>  };
>>
>>  extern char    net_boot_file_name[1024];/* Boot File name */
>> 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
>> + *
>> + * 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 64ab7ec740a..dac7b4859fb 100644
>> --- a/net/Makefile
>> +++ b/net/Makefile
>> @@ -33,6 +33,7 @@ obj-$(CONFIG_CMD_WOL)  += wol.o
>>  obj-$(CONFIG_PROT_UDP) += udp.o
>>  obj-$(CONFIG_PROT_TCP) += tcp.o
>>  obj-$(CONFIG_CMD_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 86182cc504e..d81604a57ce 100644
>> --- a/net/net.c
>> +++ b/net/net.c
>> @@ -108,6 +108,7 @@
>>  #include <test/test.h>
>>  #include <net/tcp.h>
>>  #include <net/wget.h>
>> +#include <net/netcat.h>
> That should be above net/tcp

Is there any reasons?

Should I move <net/wget.h> as well?

>
>>  #include "arp.h"
>>  #include "bootp.h"
>>  #include "cdp.h"
>> @@ -564,6 +565,14 @@ 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..633afe5c60b
>> --- /dev/null
>> +++ b/net/netcat.c
>> @@ -0,0 +1,181 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * 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
>> +
>> +static struct in_addr          server_ip;
>> +static u16                     server_port;
>> +static u16                     local_port;
>> +static int                     listen;
>> +static int                     reading;
>> +static unsigned int            packets;
>> +static enum net_loop_state     netcat_loop_state;
>> +
>> +static void show_block_marker(void)
>> +{
>> +       if ((packets % 10) == 0)
>> +               putc('#');
>> +       else if (((packets + 1) % (10 * HASHES_PER_LINE)) == 0)
> else if (!((packets + 1) % (10 * HASHS_PER_LINE)))
>
> but it would be nice if you could use 0x10 instead of 10 and masks
> here to avoid division. Or perhaps it doesn't matter.
>> +               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)
>> +               printf("\nnetcat: Transfer Fail, TCP status - %d\n", tcp->status);
>> +       else
>> +               printf("\nPackets %s %d, Transfer Successful\n",
>> +                      reading ? "received" : "transmitted", 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();
>> +}
>> +
>> +static void tcp_stream_on_snd_una_update(struct tcp_stream *tcp, u32 tx_bytes)
>> +{
>> +       show_block_marker();
>> +       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 u32 tcp_stream_rx(struct tcp_stream *tcp, u32 rx_offs, void *buf, u32 len)
>> +{
>> +       void *ptr;
>> +
>> +       packets++;
>> +       ptr = map_sysmem(image_load_addr + rx_offs, len);
>> +       memcpy(ptr, buf, len);
>> +       unmap_sysmem(ptr);
> blank line before final return. Please fix globally
>
>> +       return len;
>> +}
>> +
>> +static u32 tcp_stream_tx(struct tcp_stream *tcp, u32 tx_offs, void *buf, u32 maxlen)
>> +{
>> +       void *ptr;
>> +
>> +       if (tx_offs + maxlen > image_save_size)
>> +               maxlen = image_save_size - tx_offs;
>> +       if (maxlen == 0)
>> +               return 0;
>> +
>> +       packets++;
>> +       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
>> + */
>> +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;
>> +       packets = 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, ':') == NULL) {
> !strchr
>
> Please don't compare against 0 or NULL
>
>> +               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 == NULL) {
> !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();
>> +}
>> --
>> 2.45.2
>>
> Regards,
> Simon


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