net: dns: Allow to set variable with the resolved host ...

Add an additional [VARIABLE] parameter to the host command to allow
setting a variable with the resolved IP address.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

net: dns: leave host command with error on failure ...

When we can't resolv a host we should return an error rather than just
successfully.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

net: dns: return error codes ...

The resolv() function used to return the IP address. When net_udp_new()
fails we return an error code though which the callers of resolv() take
as an IP address. This is wrong of course and we could return 0 in this
case. Instead we return an error code and pass the resolved IP as a
pointer which allows us to return proper error codes.

This patch also adds error messages and error returns to the various
callers of resolv() which used to just continue with a zero IP and
let the user figure out what went wrong.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

net: dns: Use pr_debug ...

Use pr_debug rather than debug and add a pr_fmt string to give
the messages more context. While at it add a debug message which
prints the ip when successfully resolved.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

net: Add functions to get/set nameserver and domainname ...

It's more convenient to have getter/setter functions for
variables rather than using the detour around global vars
which use string matching and all kinds of overhead in the
background.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

net: Make domainname and nameserver globalvars ...

Register domainname and nameserver as globalvars rather than attaching
them to a dedicated net device. the global device already exists and
already contains much of the barebox configuration, so no need to add
an extra device for network config.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

convert users to %pI4 ...

Convert users of ip_to_string() and print_IPaddr() to %pI4 and
remove the now unused functions.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

string: Fix (v)asprintf prototypes ...

Our asprintf and vasprintf have different prototypes than the glibc
functions. This causes trouble when we want to share barebox code
with userspace code. Change the prototypes for (v)asprintf to match
the glibc prototypes. Since the current (v)asprintf are convenient
to use change the existing functions to b(v)asprintf.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

net: resolv: Make argument const ...

resolv() is not allowed to change the hostname argument, make it const.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

dns: handle incoming packets in the separate dns_recv() function ...

The separation of incoming packets handling makes it much easier
to run barebox dns client on top of picotcp network stack in the future.

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

commands: introduce CMD_HOST ...

... because NET_RESOLV can be used alone to turn on the functionality
of resolv().

Signed-off-by: Holger Schurig <holgerschurig@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

commands: harmonize in-barebox documentation ...

This patch does probably too much, but it's hard (and very
cumbersome/time consuming) to break it out. What is does is this:

* each command has one short description, e.g. "list MUX configuration"
* made sure the short descriptions start lowercase
* each command has one usage. That string contains just the
  options, e.g. "[-npn]". It's not part of the long help text.
* that is, it doesn't say "[OPTIONS]" anymore, every usable option
  is listed by character in this (short) option string (the long
  description is in the long help text, as before)
* help texts have been reworked, to make them
  - sometimes smaller
  - sometimes describe the options better
  - more often present themselves in a nicer format
* all long help texts are now created with BUSYBOX_CMD_HELP_
  macros, no more 'static const __maybe_unused char cmd_foobar_help[]'
* made sure the long help texts starts uppercase
* because cmdtp->name and cmdtp->opts together provide the new usage,
  all "Usage: foobar" texts have been removed from the long help texts
* BUSYBOX_CMD_HELP_TEXT() provides the trailing newline by itself, this
  is nicer in the source code
* BUSYBOX_CMD_HELP_OPT() provides the trailing newline by itself
* made sure no line gets longer than 77 characters
* delibertely renamed cmdtp->usage, so that we can get compile-time
  errors (e.g. in out-of-tree modules that use register_command()
* the 'help' command can now always emit the usage, even without
  compiled long help texts
* 'help -v' gives a list of commands with their short description, this
  is similar like the old "help" command before my patchset
* 'help -a' gives out help of all commands

Signed-off-by: Holger Schurig <holgerschurig@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

commands: group 'help' output ...

The old output of "help" was just producing a long list, that usually
scrolled of the screen (even on a X11 terminal). This list is more
compact, and also sorted by groups.

The old output format (plus grouping) is now available with 'help -v'.

Example:

   Information commands:
     ?, devinfo, help, iomem, meminfo, version
   Boot commands:
     boot, bootm, go, loadb, loads, loadx, loady, saves, uimage
   ...

Signed-off-by: Holger Schurig <holgerschurig@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

barebox: remove double semicolons ...

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

dns: fix recursive loop ...

resolv() uses getenv_ip() which in turn calls resolv(). Fix
this inifinite loop by not using getenv_ip directly.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

dns: use global nameserver/domainname ...

nameserver and domainname are now globally available in the 'net' device.
use these variables.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

net dns: remove debug code ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

net: env: getenv_ip use resolv ...

Introduce getenv_ip_dns to be able to do not do the resolv when using it in
resolv for the nameserver (Do not loop).

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>

commands: remove struct command pointer from commands ...

This is unused in all commands and thus can be removed.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

net: add a context to the packet handler ...

This is not yet used, but with this the different network
commands can get rid of their global data.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

net: add dns support ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>