This is nicer than the MAC_FMT stuff.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Based upon initial work by Keiichi Kii <k-keiichi@bx.jp.nec.com>.

This patch introduces support for dynamic reconfiguration (adding, removing
and/or modifying parameters of netconsole targets at runtime) using a
userspace interface exported via configfs.  Documentation is also updated
accordingly.

Issues and brief design overview:

(1) Kernel-initiated creation / destruction of kernel objects is not
    possible with configfs -- the lifetimes of the "config items" is managed
    exclusively from userspace.  But netconsole must support boot/module
    params too, and these are parsed in kernel and hence netpolls must be
    setup from the kernel.  Joel Becker suggested to separately manage the
    lifetimes of the two kinds of netconsole_target objects -- those created
    via configfs mkdir(2) from userspace and those specified from the
    boot/module option string.  This adds complexity and some redundancy here
    and also means that boot/module param-created targets are not exposed
    through the configfs namespace (and hence cannot be updated / destroyed
    dynamically).  However, this saves us from locking / refcounting
    complexities that would need to be introduced in configfs to support
    kernel-initiated item creation / destroy there.

(2) In configfs, item creation takes place in the call chain of the
    mkdir(2) syscall in the driver subsystem.  If we used an ioctl(2) to
    create / destroy objects from userspace, the special userspace program is
    able to fill out the structure to be passed into the ioctl and hence
    specify attributes such as local interface that are required at the time
    we set up the netpoll.  For configfs, this information is not available at
    the time of mkdir(2).  So, we keep all newly-created targets (via
    configfs) disabled by default.  The user is expected to set various
    attributes appropriately (including the local network interface if
    required) and then write(2) "1" to the "enabled" attribute.  Thus,
    netpoll_setup() is then called on the set parameters in the context of
    _this_ write(2) on the "enabled" attribute itself.  This design enables
    the user to reconfigure existing netconsole targets at runtime to be
    attached to newly-come-up interfaces that may not have existed when
    netconsole was loaded or when the targets were actually created.  All this
    effectively enables us to get rid of custom ioctls.

(3) Ultra-paranoid configfs attribute show() and store() operations, with
    sanity and input range checking, using only safe string primitives, and
    compliant with the recommendations in Documentation/filesystems/sysfs.txt.

(4) A new function netpoll_print_options() is created in the netpoll API,
    that just prints out the configured parameters for a netpoll structure.
    netpoll_parse_options() is modified to use that and it is also exported to
    be used from netconsole.
Signed-off-by: NSatyam Sharma <satyam@infradead.org>
Acked-by: NKeiichi Kii <k-keiichi@bx.jp.nec.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Based upon initial work by Keiichi Kii <k-keiichi@bx.jp.nec.com>.

This patch introduces support for multiple targets, independent of
CONFIG_NETCONSOLE_DYNAMIC -- this is useful even in the default case and
(including the infrastructure introduced in previous patches) doesn't really
add too many bytes to module text.  All the complexity (and size) comes with
the dynamic reconfigurability / userspace interface patch, and so it's
plausible users may want to keep this enabled but that disabled (say to avoid
a dependency on CONFIG_CONFIGFS_FS too).

Also update documentation to mention the use of ";" separator to specify
multiple logging targets in the boot/module option string.

Brief overview:

We maintain a target_list (and corresponding lock).  Get rid of the static
"default_target" and introduce allocation and release functions for our
netconsole_target objects (but keeping sure to preserve previous behaviour
such as default values).  During init_netconsole(), ";" is used as the
separator to identify multiple target specifications in the boot/module option
string.  The target specifications are parsed and netpolls setup.  During
exit, the target_list is torn down and all items released.
Signed-off-by: NSatyam Sharma <satyam@infradead.org>
Signed-off-by: NKeiichi Kii <k-keiichi@bx.jp.nec.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Based upon initial work by Keiichi Kii <k-keiichi@bx.jp.nec.com>.

To update fields of underlying netpoll structure at runtime on corresponding
NETDEV_CHANGEADDR or NETDEV_CHANGENAME notifications.

ioctl(SIOCSIFHWADDR or SIOCSIFNAME) could be used to change the hardware/MAC
address or name of the local interface that our netpoll is attached to.
Whenever this happens, netdev notifier chain is called out with the
NETDEV_CHANGEADDR or NETDEV_CHANGENAME event message.  We respond to that and
update the local_mac or dev_name field of the struct netpoll.  This makes
sense anyway, but is especially required for dynamic netconsole because the
netpoll structure's internal members become user visible files when either
sysfs or configfs are used.  So this helps us to keep up with the MAC
address/name changes and keep values in struct netpoll uptodate.

[ Note that ioctl(SIOCSIFADDR) to change IP address of interface at
  runtime is not handled (to update local_ip of netpoll) on purpose --
  some setups may set the local_ip to a private address, not necessary
  the actual IP address of the sender host, as presently allowed. ]
Signed-off-by: NSatyam Sharma <satyam@infradead.org>
Signed-off-by: NKeiichi Kii <k-keiichi@bx.jp.nec.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Based upon initial work by Keiichi Kii <k-keiichi@bx.jp.nec.com>.

Introduce a wrapper structure over netpoll to represent logging targets
configured in netconsole.  This will get extended with other members in
further patches.

This is done independent of the (to-be-introduced) NETCONSOLE_DYNAMIC config
option so that we're able to drastically cut down on the #ifdef complexity of
final netconsole.c.  Also, struct netconsole_target would be required for
multiple targets support also, and not just dynamic reconfigurability.
Signed-off-by: NSatyam Sharma <satyam@infradead.org>
Signed-off-by: NKeiichi Kii <k-keiichi@bx.jp.nec.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Based upon initial work by Keiichi Kii <k-keiichi@bx.jp.nec.com>.

Avoid unnecessarily disabling interrupts and calling netpoll_send_udp() if the
corresponding local interface is not up.
Signed-off-by: NSatyam Sharma <satyam@infradead.org>
Acked-by: NKeiichi Kii <k-keiichi@bx.jp.nec.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Based upon initial work by Keiichi Kii <k-keiichi@bx.jp.nec.com>.

Presently, boot/module parameters are set up quite differently for the case of
built-in netconsole (__setup() -> obsolete_checksetup() ->
netpoll_parse_options() -> strlen(config) == 0 in init_netconsole()) vs
modular netconsole (module_param_string() -> string copied to the config
variable -> strlen(config) != 0 init_netconsole() -> netpoll_parse_options()).

This patch makes both of them similar by doing exactly the equivalent of a
module_param_string() in option_setup() also -- just copying the param string
passed from the kernel command line into "config" variable.  So,
strlen(config) != 0 in both cases, and netpoll_parse_options() is always
called from init_netconsole(), thus making the setup logic for both cases
similar.

Now, option_setup() is only ever called / used for the built-in case, so we
put it inside a #ifndef MODULE, otherwise gcc will complain about
option_setup() being "defined but not used".  Also, the "configured" variable
is redundant with this patch and hence removed.
Signed-off-by: NSatyam Sharma <satyam@infradead.org>
Signed-off-by: NKeiichi Kii <k-keiichi@bx.jp.nec.com>
Acked-by: NMatt Mackall <mpm@selenic.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Based upon initial work by Keiichi Kii <k-keiichi@bx.jp.nec.com>.

The (!np.dev) check in write_msg() is bogus (always false), because: np.dev is
set by netpoll_setup(), which is called by init_netconsole() before
register_console(), so write_msg() cannot be triggered unless netpoll_setup()
successfully set np.dev.  Also np.dev cannot go away from under us, because
netpoll_setup() grabs us reference on it.  So let's remove the bogus check.
Signed-off-by: NSatyam Sharma <satyam@infradead.org>
Acked-by: NKeiichi Kii <k-keiichi@bx.jp.nec.com>
Acked-by: NMatt Mackall <mpm@selenic.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Based upon initial work by Keiichi Kii <k-keiichi@bx.jp.nec.com>.

(1) Remove unwanted headers.
(2) Mark __init and __exit as appropriate.
(3) Various trivial codingstyle and prettification stuff.
Signed-off-by: NSatyam Sharma <satyam@infradead.org>
Signed-off-by: NKeiichi Kii <k-keiichi@bx.jp.nec.com>
Acked-by: NMatt Mackall <mpm@selenic.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The beast had a long and not very happy history. At one
point, a friend (netdump) had asked that he open up a little.
Well, the friend was long gone now, and the beast had
this dangling piece hanging (netpoll_queue).

It wasn't hard to stitch the netpoll_queue back in
where it belonged and make everything tidy.
Signed-off-by: NStephen Hemminger <shemminger@osdl.org>

The beast was not always healthy. When it was sick,
it tended to be laconic and not tell anyone the real problem.
A few small changes had it telling the world about its
problems, if they really wanted to hear.
Signed-off-by: NStephen Hemminger <shemminger@osdl.org>

From: Matt Mackall <mpm@selenic.com>

netconsole is being wrong here.  If it wasn't enabled there's no error.
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Set .name in netconsole's struct console to identify the
struct's owner.
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Acked-by: NMatt Mackall <mpm@selenic.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The boot cmdline is parsed in parse_early_param() and
parse_args(,unknown_bootoption).

And __setup() is used in obsolete_checksetup().

	start_kernel()
		-> parse_args()
			-> unknown_bootoption()
				-> obsolete_checksetup()

If __setup()'s callback (->setup_func()) returns 1 in
obsolete_checksetup(), obsolete_checksetup() thinks a parameter was
handled.

If ->setup_func() returns 0, obsolete_checksetup() tries other
->setup_func().  If all ->setup_func() that matched a parameter returns 0,
a parameter is seted to argv_init[].

Then, when runing /sbin/init or init=app, argv_init[] is passed to the app.
If the app doesn't ignore those arguments, it will warning and exit.

This patch fixes a wrong usage of it, however fixes obvious one only.
Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!