scsi: target: iscsi: Prevent login threads from racing between each other

The tpg->np_login_sem is a semaphore that is used to serialize the login
process when multiple login threads run concurrently against the same
target portal group.

The iscsi_target_locate_portal() function finds the tpg, calls
iscsit_access_np() against the np_login_sem semaphore and saves the tpg
pointer in conn->tpg;

If iscsi_target_locate_portal() fails, the caller will check for the
conn->tpg pointer and, if it's not NULL, then it will assume that
iscsi_target_locate_portal() called iscsit_access_np() on the semaphore.

Make sure that conn->tpg gets initialized only if iscsit_access_np() was
successful, otherwise iscsit_deaccess_np() may end up being called against
a semaphore we never took, allowing more than one thread to access the same
tpg.

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Link: https://lore.kernel.org/r/20230508162219.1731964-4-mlombard@redhat.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: iscsi: Fix hang in the iSCSI login code

If the initiator suddenly stops sending data during a login while keeping
the TCP connection open, the login_work won't be scheduled and will never
release the login semaphore; concurrent login operations will therefore get
stuck and fail.

The bug is due to the inability of the login timeout code to properly
handle this particular case.

Fix the problem by replacing the old per-NP login timer with a new
per-connection timer.

The timer is started when an initiator connects to the target; if it
expires, it sends a SIGINT signal to the thread pointed at by the
conn->login_kworker pointer.

conn->login_kworker is set by calling the iscsit_set_login_timer_kworker()
helper, initially it will point to the np thread; When the login
operation's control is in the process of being passed from the NP-thread to
login_work, the conn->login_worker pointer is set to NULL. Finally,
login_kworker will be changed to point to the worker thread executing the
login_work job.

If conn->login_kworker is NULL when the timer expires, it means that the
login operation hasn't been completed yet but login_work isn't running, in
this case the timer will mark the login process as failed and will schedule
login_work so the latter will be forced to free the resources it holds.

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Link: https://lore.kernel.org/r/20230508162219.1731964-2-mlombard@redhat.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

net/sock: Introduce trace_sk_data_ready()

As suggested by Cong, introduce a tracepoint for all ->sk_data_ready()
callback implementations. For example:

<...>
iperf-609 [002] ..... 70.660425: sk_data_ready: family=2 protocol=6 func=sock_def_readable
iperf-609 [002] ..... 70.660436: sk_data_ready: family=2 protocol=6 func=sock_def_readable
<...>

Suggested-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

scsi: target: iscsi: Fix a race condition between login_work and the login thread

In case a malicious initiator sends some random data immediately after a
login PDU; the iscsi_target_sk_data_ready() callback will schedule the
login_work and, at the same time, the negotiation may end without clearing
the LOGIN_FLAGS_INITIAL_PDU flag (because no additional PDU exchanges are
required to complete the login).

The login has been completed but the login_work function will find the
LOGIN_FLAGS_INITIAL_PDU flag set and will never stop from rescheduling
itself; at this point, if the initiator drops the connection, the
iscsit_conn structure will be freed, login_work will dereference a released
socket structure and the kernel crashes.

BUG: kernel NULL pointer dereference, address: 0000000000000230
PF: supervisor write access in kernel mode
PF: error_code(0x0002) - not-present page
Workqueue: events iscsi_target_do_login_rx [iscsi_target_mod]
RIP: 0010:_raw_read_lock_bh+0x15/0x30
Call trace:
iscsi_target_do_login_rx+0x75/0x3f0 [iscsi_target_mod]
process_one_work+0x1e8/0x3c0

Fix this bug by forcing login_work to stop after the login has been
completed and the socket callbacks have been restored.

Add a comment to clearify the return values of iscsi_target_do_login()

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Link: https://lore.kernel.org/r/20221115125638.102517-1-mlombard@redhat.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: iscsi: Do not require target authentication

RFC7143 states that Initiator decides what type of authentication to
use:

The initiator MUST continue with:
CHAP_N=<N> CHAP_R=<R>
or, if it requires target authentication, with:
CHAP_N=<N> CHAP_R=<R> CHAP_I=<I> CHAP_C=<C>

Allow one way authentication if mutual authentication is configured. That
passes some tests from Windows HLK for Mutual CHAP with iSNS.

Link: https://lore.kernel.org/r/20220718152555.17084-5-d.bogdanov@yadro.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Dmitry Bogdanov <d.bogdanov@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: iscsi: Allow AuthMethod=None

Allow negotiating AuthMethod=None at CSG=0 (Security Negotiation) when
authentication is not required. That is required by the CHAP test in
Windows HLK.

Link: https://lore.kernel.org/r/20220718152555.17084-4-d.bogdanov@yadro.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Dmitry Bogdanov <d.bogdanov@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: iscsi: Support base64 in CHAP

RFC7143 allows both Base64 and Hex encoding for CHAP binary entities like
Challenge and Response. Currently the Linux iSCSI target supports only Hex
encoding.

Add support for Base64 encoded CHAP Challenge and CHAP Response required
for CHAP tests in Windows HLK.

Link: https://lore.kernel.org/r/20220718152555.17084-3-d.bogdanov@yadro.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Dmitry Bogdanov <d.bogdanov@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: iscsi: Fix NULL pointer dereference in iscsi_conn_auth_required()

Fix following coccicheck error:

./drivers/target/iscsi/iscsi_target_nego.c:831:13-26: ERROR: se_nacl is NULL but dereferenced.

Link: https://lore.kernel.org/r/20220613014321.107045-1-yang.lee@linux.alibaba.com
Fixes: a75fcb0912a5 ("scsi: target: iscsi: Extract auth functions")
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: iscsi: Control authentication per ACL

Add acls/{ACL}/attrib/authentication attribute that controls authentication
for particular ACL. By default, this attribute inherits a value of the
authentication attribute of the target port group to keep backward
compatibility.

Authentication attribute has 3 states:

"0" - authentication is turned off for this ACL

"1" - authentication is required for this ACL

"-1" - authentication is inherited from TPG

Link: https://lore.kernel.org/r/20220523095905.26070-4-d.bogdanov@yadro.com
Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Reviewed-by: Konstantin Shelekhin <k.shelekhin@yadro.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Dmitry Bogdanov <d.bogdanov@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: iscsi: Extract auth functions

Create functions that answers simple questions: Whether authentication is
required, what credentials, whether connection is autenticated.

Link: https://lore.kernel.org/r/20220523095905.26070-3-d.bogdanov@yadro.com
Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Reviewed-by: Konstantin Shelekhin <k.shelekhin@yadro.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Lee Duncan <lduncan@suse.com>
Signed-off-by: Dmitry Bogdanov <d.bogdanov@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: iscsi: Add upcast helpers

iSCSI target is cluttered with open-coded container_of() conversions from
se_nacl to iscsi_node_acl. The code could be cleaned by introducing a
helper - to_iscsi_nacl() (similar to other helpers in target core).

While at it, make another iSCSI conversion helper consistent and rename
iscsi_tpg() helper to to_iscsi_tpg().

Link: https://lore.kernel.org/r/20220523095905.26070-2-d.bogdanov@yadro.com
Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Reviewed-by: Konstantin Shelekhin <k.shelekhin@yadro.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Lee Duncan <lduncan@suse.com>
Signed-off-by: Dmitry Bogdanov <d.bogdanov@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: iscsi: Rename iscsi_session to iscsit_session

The structure iscsi_session naming is used by the iSCSI initiator
driver. Rename the target session to iscsit_session to have more readable
code.

Link: https://lore.kernel.org/r/20220428092939.36768-3-mgurtovoy@nvidia.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: iscsi: Rename iscsi_conn to iscsit_conn

The structure iscsi_conn naming is used by the iSCSI initiator
driver. Rename the target conn to iscsit_conn to have more readable code.

Link: https://lore.kernel.org/r/20220428092939.36768-2-mgurtovoy@nvidia.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: iscsi: Rename iscsi_cmd to iscsit_cmd

The structure iscsi_cmd naming is used by the iSCSI initiator driver.
Rename the target cmd to iscsit_cmd to have more readable code.

Link: https://lore.kernel.org/r/20220428092939.36768-1-mgurtovoy@nvidia.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: iscsi: Drop unnecessary container_of()

The structure pointer passed to container_of() is never NULL; that was
already checked. That means that the result of container_of() operations
on it is also never NULL, even though se_node_acl is the first element
of the structure embedding it. On top of that, it is misleading to perform
a NULL check on the result of container_of() because the position of the
contained element could change, which would make the test invalid.
Remove the unnecessary NULL check.

As it turns out, the container_of operation was only made for the purpose
of the NULL check. If the container_of is actually needed, it is repeated
later. Remove the container_of operation as well.

The NULL check was identified and removed with the following Coccinelle
script.

@@
type t;
identifier v;
statement s;
@@

<+...
(
t v = container_of(...);
|
v = container_of(...);
)
...
when != v
- if (\( !v \| v == NULL \) ) s
...+>

Link: https://lore.kernel.org/r/20210510040817.2050266-1-linux@roeck-us.net
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Hou Pu <houpu@bytedance.com>
Cc: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: iscsi: Switch to kmemdup_nul()

Use kmemdup_nul() helper instead of open-coding to simplify the code.

Link: https://lore.kernel.org/r/20210402092517.2445595-1-yangyingliang@huawei.com
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: iscsi: Remove unused macro TEXT_LEN

Remove unused macro to fix the following compilation warning:

drivers/target//iscsi/iscsi_target_nego.c:31: warning: macro "TEXT_LEN" is not used [-Wunused-macros]
#define TEXT_LEN 4096

Link: https://lore.kernel.org/r/20210228055645.22253-11-chaitanya.kulkarni@wdc.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: iscsi: Fix hang in iscsit_access_np() when getting tpg->np_login_sem

The iSCSI target login thread might get stuck with the following stack:

cat /proc/`pidof iscsi_np`/stack
[<0>] down_interruptible+0x42/0x50
[<0>] iscsit_access_np+0xe3/0x167
[<0>] iscsi_target_locate_portal+0x695/0x8ac
[<0>] __iscsi_target_login_thread+0x855/0xb82
[<0>] iscsi_target_login_thread+0x2f/0x5a
[<0>] kthread+0xfa/0x130
[<0>] ret_from_fork+0x1f/0x30

This can be reproduced via the following steps:

1. Initiator A tries to log in to iqn1-tpg1 on port 3260. After finishing
PDU exchange in the login thread and before the negotiation is finished
the the network link goes down. At this point A has not finished login
and tpg->np_login_sem is held.

2. Initiator B tries to log in to iqn2-tpg1 on port 3260. After finishing
PDU exchange in the login thread the target expects to process remaining
login PDUs in workqueue context.

3. Initiator A' tries to log in to iqn1-tpg1 on port 3260 from a new
socket. A' will wait for tpg->np_login_sem with np->np_login_timer
loaded to wait for at most 15 seconds. The lock is held by A so A'
eventually times out.

4. Before A' got timeout initiator B gets negotiation failed and calls
iscsi_target_login_drop()->iscsi_target_login_sess_out(). The
np->np_login_timer is canceled and initiator A' will hang forever.
Because A' is now in the login thread, no new login requests can be
serviced.

Fix this by moving iscsi_stop_login_thread_timer() out of
iscsi_target_login_sess_out(). Also remove iscsi_np parameter from
iscsi_target_login_sess_out().

Link: https://lore.kernel.org/r/20200729130343.24976-1-houpu@bytedance.com
Cc: stable@vger.kernel.org
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Hou Pu <houpu@bytedance.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: iscsi: Fix inconsistent debug message

Commit 25cdda95fda7 ("iscsi-target: Fix initial login PDU asynchronous
socket close OOPs") changed the return value of
__iscsi_target_sk_check_close(). However, pr_debug is still printing FALSE
when returning TRUE which is a little confusing.

Link: https://lore.kernel.org/r/20200716100212.4237-3-houpu@bytedance.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Hou Pu <houpu@bytedance.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: iscsi: Fix login error when receiving

iscsi_target_sk_data_ready() could be invoked indirectly by
iscsi_target_do_login_rx() from the workqueue like this:

iscsi_target_do_login_rx()
iscsi_target_do_login()
iscsi_target_do_tx_login_io()
iscsit_put_login_tx()
iscsi_login_tx_data()
tx_data()
sock_sendmsg_nosec()
tcp_sendmsg()
release_sock()
sk_backlog_rcv()
tcp_v4_do_rcv()
tcp_data_ready()
iscsi_target_sk_data_ready()

At that time LOGIN_FLAGS_READ_ACTIVE is not cleared and
iscsi_target_sk_data_ready will not read data from the socket. Some iscsi
initiators (libiscsi) will wait forever for a reply.

LOGIN_FLAGS_READ_ACTIVE should be cleared early just after doing the
receive and before writing to the socket in iscsi_target_do_login_rx.

Unfortunately, LOGIN_FLAGS_READ_ACTIVE is also used by sk_state_change to
do login cleanup if a socket was closed at login time. It is supposed to be
cleared after the login PDU is successfully processed and replied.

Introduce another flag, LOGIN_FLAGS_WRITE_ACTIVE, to cover the transmit
part.

Link: https://lore.kernel.org/r/20200716100212.4237-2-houpu@bytedance.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Hou Pu <houpu@bytedance.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target/iscsi: fix possible condition with no effect (if == else)

Fix the following warning reported by coccicheck:

drivers/target/iscsi/iscsi_target_nego.c:175:6-8: WARNING: possible
condition with no effect (if == else)

Signed-off-by: Hariprasad Kelam <hariprasad.kelam@gmail.com>
Reviewed-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157

Based on 3 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version [author] [kishon] [vijay] [abraham]
[i] [kishon]@[ti] [com] this program is distributed in the hope that
it will be useful but without any warranty without even the implied
warranty of merchantability or fitness for a particular purpose see
the gnu general public license for more details

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version [author] [graeme] [gregory]
[gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i]
[kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema]
[hk] [hemahk]@[ti] [com] this program is distributed in the hope
that it will be useful but without any warranty without even the
implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1105 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

iscsi-target: make sure to wake up sleeping login worker

Mike Christie reports:
Starting in 4.14 iscsi logins will fail around 50% of the time.

Problem appears to be that iscsi_target_sk_data_ready() callback may
return without doing anything in case it finds the login work queue
is still blocked in sock_recvmsg().

Nicholas Bellinger says:
It would indicate users providing their own ->sk_data_ready() callback
must be responsible for waking up a kthread context blocked on
sock_recvmsg(..., MSG_WAITALL), when a second ->sk_data_ready() is
received before the first sock_recvmsg(..., MSG_WAITALL) completes.

So, do this and invoke the original data_ready() callback -- in
case of tcp sockets this takes care of waking the thread.

Disclaimer: I do not understand why this problem did not show up before
tcp prequeue removal.

(Drop WARN_ON usage - nab)

Reported-by: Mike Christie <mchristi@redhat.com>
Bisected-by: Mike Christie <mchristi@redhat.com>
Tested-by: Mike Christie <mchristi@redhat.com>
Diagnosed-by: Nicholas Bellinger <nab@linux-iscsi.org>
Fixes: e7942d0633c4 ("tcp: remove prequeue support")
Signed-off-by: Florian Westphal <fw@strlen.de>
Cc: stable@vger.kernel.org # 4.14+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target/iscsi: Convert timers to use timer_setup()

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly. Includes a fix for correcting an
on-stack timer usage.

Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
Cc: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Jiang Yi <jiangyilism@gmail.com>
Cc: Varun Prakash <varun@chelsio.com>
Cc: linux-scsi@vger.kernel.org
Cc: target-devel@vger.kernel.org
Reviewed-and-Tested-by: Bart Van Assche <Bart.VanAssche@wdc.com>
Signed-off-by: Kees Cook <keescook@chromium.org>

target/iscsi: Simplify timer manipulation code

Move timer initialization from before add_timer() to the context
where the containing object is initialized. Use setup_timer() and
mod_timer() instead of open coding these. Use 'jiffies' instead
of get_jiffies_64() when calculating expiry times because expiry
times have type unsigned long, just like 'jiffies'.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Andy Grover <agrover@redhat.com>
Cc: David Disseldorp <ddiss@suse.de>
Signed-off-by: Kees Cook <keescook@chromium.org>

iscsi-target: Add login_keys_workaround attribute for non RFC initiators

This patch re-introduces part of a long standing login workaround that
was recently dropped by:

commit 1c99de981f30b3e7868b8d20ce5479fa1c0fea46
Author: Nicholas Bellinger <nab@linux-iscsi.org>
Date: Sun Apr 2 13:36:44 2017 -0700

iscsi-target: Drop work-around for legacy GlobalSAN initiator

Namely, the workaround for FirstBurstLength ended up being required by
Mellanox Flexboot PXE boot ROMs as reported by Robert.

So this patch re-adds the work-around for FirstBurstLength within
iscsi_check_proposer_for_optional_reply(), and makes the key optional
to respond when the initiator does not propose, nor respond to it.

Also as requested by Arun, this patch introduces a new TPG attribute
named 'login_keys_workaround' that controls the use of both the
FirstBurstLength workaround, as well as the two other existing
workarounds for gPXE iSCSI boot client.

By default, the workaround is enabled with login_keys_workaround=1,
since Mellanox FlexBoot requires it, and Arun has verified the Qlogic
MSFT initiator already proposes FirstBurstLength, so it's uneffected
by this re-adding this part of the original work-around.

Reported-by: Robert LeBlanc <robert@leblancnet.us>
Cc: Robert LeBlanc <robert@leblancnet.us>
Reviewed-by: Arun Easi <arun.easi@cavium.com>
Cc: <stable@vger.kernel.org> # 3.1+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Kill left-over iscsi_target_do_cleanup

With commit 25cdda95fda7 in place to address the initial login
PDU asynchronous socket close OOPs, go ahead and kill off the
left-over iscsi_target_do_cleanup() and ->login_cleanup_work.

Reported-by: Mike Christie <mchristi@redhat.com>
Cc: Mike Christie <mchristi@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Fix initial login PDU asynchronous socket close OOPs

This patch fixes a OOPs originally introduced by:

commit bb048357dad6d604520c91586334c9c230366a14
Author: Nicholas Bellinger <nab@linux-iscsi.org>
Date: Thu Sep 5 14:54:04 2013 -0700

iscsi-target: Add sk->sk_state_change to cleanup after TCP failure

which would trigger a NULL pointer dereference when a TCP connection
was closed asynchronously via iscsi_target_sk_state_change(), but only
when the initial PDU processing in iscsi_target_do_login() from iscsi_np
process context was blocked waiting for backend I/O to complete.

To address this issue, this patch makes the following changes.

First, it introduces some common helper functions used for checking
socket closing state, checking login_flags, and atomically checking
socket closing state + setting login_flags.

Second, it introduces a LOGIN_FLAGS_INITIAL_PDU bit to know when a TCP
connection has dropped via iscsi_target_sk_state_change(), but the
initial PDU processing within iscsi_target_do_login() in iscsi_np
context is still running. For this case, it sets LOGIN_FLAGS_CLOSED,
but doesn't invoke schedule_delayed_work().

The original NULL pointer dereference case reported by MNC is now handled
by iscsi_target_do_login() doing a iscsi_target_sk_check_close() before
transitioning to FFP to determine when the socket has already closed,
or iscsi_target_start_negotiation() if the login needs to exchange
more PDUs (eg: iscsi_target_do_login returned 0) but the socket has
closed. For both of these cases, the cleanup up of remaining connection
resources will occur in iscsi_target_start_negotiation() from iscsi_np
process context once the failure is detected.

Finally, to handle to case where iscsi_target_sk_state_change() is
called after the initial PDU procesing is complete, it now invokes
conn->login_work -> iscsi_target_do_login_rx() to perform cleanup once
existing iscsi_target_sk_check_close() checks detect connection failure.
For this case, the cleanup of remaining connection resources will occur
in iscsi_target_do_login_rx() from delayed workqueue process context
once the failure is detected.

Reported-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Tested-by: Mike Christie <mchristi@redhat.com>
Cc: Mike Christie <mchristi@redhat.com>
Reported-by: Hannes Reinecke <hare@suse.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Varun Prakash <varun@chelsio.com>
Cc: <stable@vger.kernel.org> # v3.12+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h>

We are going to split <linux/sched/signal.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder <linux/sched/signal.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

target/iscsi: Fix indentation in iscsi_target_start_negotiation()

This patch avoids that smatch complains about inconsistent
indentation in iscsi_target_start_negotiation().

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: Minimize #include directives

Remove superfluous #include directives from the include/target/*.h
files. Add missing #include directives to other *.h and *.c files.
Use forward declarations for structures where possible. This
change reduces the build time for make M=drivers/target on my
laptop from 27.1s to 18.7s or by about 30%.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Bryant G. Ly <bryantly@linux.vnet.ibm.com>

iscsi-target: Fix early sk_data_ready LOGIN_FLAGS_READY race

There is a iscsi-target/tcp login race in LOGIN_FLAGS_READY
state assignment that can result in frequent errors during
iscsi discovery:

"iSCSI Login negotiation failed."

To address this bug, move the initial LOGIN_FLAGS_READY
assignment ahead of iscsi_target_do_login() when handling
the initial iscsi_target_start_negotiation() request PDU
during connection login.

As iscsi_target_do_login_rx() work_struct callback is
clearing LOGIN_FLAGS_READ_ACTIVE after subsequent calls
to iscsi_target_do_login(), the early sk_data_ready
ahead of the first iscsi_target_do_login() expects
LOGIN_FLAGS_READY to also be set for the initial
login request PDU.

As reported by Maged, this was first obsered using an
MSFT initiator running across multiple VMWare host
virtual machines with iscsi-target/tcp.

Reported-by: Maged Mokhtar <mmokhtar@binarykinetics.com>
Tested-by: Maged Mokhtar <mmokhtar@binarykinetics.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: export symbols

export symbols for ISCSI_HW_OFFLOAD
transport drivers.

Signed-off-by: Varun Prakash <varun@chelsio.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Fix rx_login_comp hang after login failure

This patch addresses a case where iscsi_target_do_tx_login_io()
fails sending the last login response PDU, after the RX/TX
threads have already been started.

The case centers around iscsi_target_rx_thread() not invoking
allow_signal(SIGINT) before the send_sig(SIGINT, ...) occurs
from the failure path, resulting in RX thread hanging
indefinately on iscsi_conn->rx_login_comp.

Note this bug is a regression introduced by:

commit e54198657b65625085834847ab6271087323ffea
Author: Nicholas Bellinger <nab@linux-iscsi.org>
Date: Wed Jul 22 23:14:19 2015 -0700

iscsi-target: Fix iscsit_start_kthreads failure OOPs

To address this bug, complete ->rx_login_complete for good
measure in the failure path, and immediately return from
RX thread context if connection state did not actually reach
full feature phase (TARG_CONN_STATE_LOGGED_IN).

Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: <stable@vger.kernel.org> # v3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: Fix max_cmd_sn increment w/o cmdsn mutex regressions

Current for-next iscsi target is broken:

commit 109e2381749c1cfd94a0d22b2b54142539024973
Author: Roland Dreier <roland@purestorage.com>
Date: Thu Jul 23 14:53:32 2015 -0700

target: Drop iSCSI use of mutex around max_cmd_sn increment

This patch fixes incorrect pr_debug() + atomic_inc_return() usage
within iscsit_increment_maxcmdsn() code.

Also fix funny iscsit_determine_maxcmdsn() usage and update
iscsi_target_do_tx_login_io() code.

Reported-by: Sagi Grimberg <sagig@mellanox.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: Drop iSCSI use of mutex around max_cmd_sn increment

In a performance profile, taking a mutex in iscsit_increment_maxcmdsn()
shows up very high. However taking a mutex around "sess->max_cmd_sn += 1"
seems pretty silly: we're not serializing against other contexts in
any useful way.

I did a quick audit and there don't appear to be any other places that
use max_cmd_sn within the mutex more than once, so this lock can't be
providing any useful serialization.

(Get correct values for logging - fix whitespace damage)

Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Spencer Baugh <sbaugh@catern.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Fix iscsit_start_kthreads failure OOPs

This patch fixes a regression introduced with the following commit
in v4.0-rc1 code, where a iscsit_start_kthreads() failure triggers
a NULL pointer dereference OOPs:

commit 88dcd2dab5c23b1c9cfc396246d8f476c872f0ca
Author: Nicholas Bellinger <nab@linux-iscsi.org>
Date: Thu Feb 26 22:19:15 2015 -0800

iscsi-target: Convert iscsi_thread_set usage to kthread.h

To address this bug, move iscsit_start_kthreads() immediately
preceeding the transmit of last login response, before signaling
a successful transition into full-feature-phase within existing
iscsi_target_do_tx_login_io() logic.

This ensures that no target-side resource allocation failures can
occur after the final login response has been successfully sent.

Also, it adds a iscsi_conn->rx_login_comp to allow the RX thread
to sleep to prevent other socket related failures until the final
iscsi_post_login_handler() call is able to complete.

Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: <stable@vger.kernel.org> # v3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Move iscsi_target_[core,stat].h under linux include

Seems strange to see in include/target/iscsi/iscsi_transport.h:
include "../../../drivers/target/iscsi/iscsi_target_core.h"

Move it to it's natural location.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: cleanup some boolean tests

Convert "x == true" to "x" and "x == false" to "!x".

Signed-off-by: Christophe Vu-Brugier <cvubrugier@yahoo.fr>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Reject zero-length payloads during SecurityNegotiation

This patch changes iscsi_target_handle_csg_zero() to explicitly
reject login requests in SecurityNegotiation with a zero-length
payload, following the language in RFC-3720 Section 8.2:

Whenever an iSCSI target gets a response whose keys, or their
values, are not according to the step definition, it MUST answer
with a Login reject with the "Initiator Error" or "Missing Parameter"
status.

Previously when a zero-length login request in CSG=0 was received,
the target would send a login response with CSG=0 + T_BIT=0 asking
the initiator to complete authentication, and not fail the login
until MAX_LOGIN_PDUS was reached. This change will now immediately
fail the login attempt with ISCSI_STATUS_CLS_INITIATOR_ERR status.

Reported-by: Tejas Vaykole <tejas.vaykole@calsoftinc.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

net: Fix use after free by removing length arg from sk_data_ready callbacks.

Several spots in the kernel perform a sequence like:

skb_queue_tail(&sk->s_receive_queue, skb);
sk->sk_data_ready(sk, skb->len);

But at the moment we place the SKB onto the socket receive queue it
can be consumed and freed up. So this skb->len access is potentially
to freed up memory.

Furthermore, the skb->len can be modified by the consumer so it is
possible that the value isn't accurate.

And finally, no actual implementation of this callback actually uses
the length argument. And since nobody actually cared about it's
value, lots of call sites pass arbitrary values in such as '0' and
even '1'.

So just remove the length argument from the callback, that way there
is no confusion whatsoever and all of these use-after-free cases get
fixed as a side effect.

Based upon a patch by Eric Dumazet and his suggestion to audit this
issue tree-wide.

Signed-off-by: David S. Miller <davem@davemloft.net>

iscsi-target: Pre-allocate more tags to avoid ack starvation

This patch addresses an traditional iscsi-target fabric ack starvation
issue where iscsit_allocate_cmd() -> percpu_ida_alloc_state() ends up
hitting slow path percpu-ida code, because iscsit_ack_from_expstatsn()
is expected to free ack'ed tags after tag allocation.

This is done to take into account the tags waiting to be acknowledged
and released in iscsit_ack_from_expstatsn(), but who's number are not
directly limited by the CmdSN Window queue_depth being enforced by
the target.

So that said, this patch bumps up the pre-allocated number of
per session tags to:

(max(queue_depth, ISCSIT_MIN_TAGS) * 2) + ISCSIT_EXTRA_TAGS

for good measure to avoid the percpu_ida_alloc_state() slow path.

Cc: <stable@vger.kernel.org> #3.12+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: fix extract_param to handle buffer length corner case

extract_param() is called with max_length set to the total size of the
output buffer. It's not safe to allow a parameter length equal to the
buffer size as the terminating null would be written one byte past the
end of the output buffer.

Signed-off-by: Eric Seppanen <eric@purestorage.com>
Cc: <stable@vger.kernel.org> #3.1+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target/iscsi: Remove macros that contain typecasts

These just want to return a pointer instead of a value, but are otherwise
the same.

ISCSI_TPG_LUN macro was unused.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target/iscsi: Remove iscsi dereferencing macros

These are all straightforward.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target; Allow an extra tag_num / 2 number of percpu_ida tags

This patch bumps the default number of tags allocated per session by
iscsi-target via transport_alloc_session_tags() -> percpu_ida_init()
by another (tag_num / 2).

This is done to take into account the tags waiting to be acknowledged
and released in iscsit_ack_from_expstatsn(), but who's number are not
directly limited by the CmdSN Window queue_depth being enforced by
the target.

Using a larger value here is also useful to prevent percpu_ida_alloc()
from having to steal tags from other CPUs when no tags are available
on the local CPU, while waiting for unacknowledged tags to be released.

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: Update copyright ownership/year information to 2013

Update copyright ownership/year information for target-core,
loopback, iscsi-target, tcm_qla2xx, vhost and iser-target.

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Convert to per-cpu ida_alloc + ida_free command map

This patch changes iscsi-target to use transport_alloc_session_tags()
pre-allocation logic for per-cpu session tag pooling with internal
ida_alloc() + ida_free() calls based upon the saved se_cmd->map_tag id.

This includes tag pool setup based upon per NodeACL queue_depth after
locating se_node_acl in iscsi_target_locate_portal().

Also update iscsit_allocate_cmd() and iscsit_release_cmd() to use
percpu_ida_alloc() and percpu_ida_free() respectively.

v5 changes;
- Convert to percpu_ida.h include

v2 changes:
- Fix bug with SessionType=Discovery in iscsi_target_locate_portal()

Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: Nicholas Bellinger <nab@daterainc.com>

iscsi-target: Remove left-over iscsi_target_do_login_io

There is no need for iscsi_target_do_login_io() anymore in modern code,
so go ahead and call iscsi_target_do_tx_login_io() directly within
iscsi_target_do_login().

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Add sk->sk_state_change to cleanup after TCP failure

This patch adds a sock->sk_state_change() -> iscsi_target_sk_state_change()
callback in order to handle transient TCP failures during the login process,
where sock->sk_data_ready() -> iscsi_target_sk_data_ready() may not be
called to release connection resources, and relinquish tpg->np_login_lock
via iscsit_deaccess_np()

It performs the sk->sk_state check using iscsi_target_sk_state_check() to
look for TCP_CLOSE_WAIT + TCP_CLOSE, and invokes schedule_delayed_work() ->
iscsi_target_do_cleanup() to perform the remaining cleanup from process
context.

It adds an explicit sk_state_check to iscsi_target_do_login() in order
to determine a state failure when iscsi_target_sk_state_change() may
not be able to proceed before LOGIN_FLAGS_READY=1 is set.

Also use sk->sk_sndtimeo -> sk->sk_rcvtimeo settings during login to
iscsi_target_set_sock_callbacks(), and revert back post login to use
MAX_SCHEDULE_TIMEOUT in iscsi_target_restore_sock_callbacks().

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Add login negotiation multi-plexing support

This patch adds support for login negotiation multi-plexing in
iscsi-target code.

This involves handling the first login request PDU + payload and
login response PDU + payload within __iscsi_target_login_thread()
process context, and then changing struct sock->sk_data_ready()
so that all subsequent exchanges are handled by workqueue process
context, to allow other incoming login requests to be received
in parallel by __iscsi_target_login_thread().

Upon login negotiation completion (or failure), ->sk_data_ready()
is replaced with the original kernel sockets handler saved in
iscsi_conn->orig_data_ready.

v3 changes:
- Convert iscsi_target_sk_data_ready() lock access to
write[lock,unlock]_bh()
- Only clear LOGIN_FLAGS_READ_ACTIVE when iscsi_target_do_login()
returns zero
- Add LOGIN_FLAGS_READY + LOGIN_FLAGS_CLOSED bit checks to
iscsi_target_sk_data_ready()
- Make INIT_DELAYED_WORK() + iscsi_target_set_sock_callbacks() setup
happen earlier by moving from iscsi_target_start_negotiation() into
iscsi_target_locate_portal()
- Set LOGIN_FLAGS_READY bit in iscsi_target_start_negotiation()
after iscsi_target_do_login() returns zero.

v2 changes:
- Add login_timer in iscsi_target_do_login_rx() to avoid
possible endless sleep with MSG_WAITALL for traditional
iscsi-target in certain network configurations.
- Convert lprintk() -> pr_debug()
- Remove forward declarations of iscsi_target_set_sock_callbacks(),
iscsi_target_restore_sock_callbacks() and iscsi_target_sk_data_ready()
- Make iscsi_target_set_sock_callbacks + iscsi_target_restore_sock_callbacks()
static (Fengguang)
- Make iscsi_target_do_login_rx() safe for iser-target w/o conn->sock

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Add demo-mode TPG authentication context support

This patch adds a auth configfs group context following existing
explict NodeACL and discovery auth within:

/sys/kernel/config/target/iscsi/$TARGETNAME/$TPGT/auth/

This patch allows these attributes to be used for CHAP authentication
an TPG is configured in demo-mode (generate_node_acl=1).

Note this authentication information takes precedence over NodeACL
authentication when struct se_node_acl->dynamic_node_acl is present.

Cc: Dax Kelson <dkelson@gurulabs.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Remove left over v3.10-rc debug printks

Reported-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Refactor RX PDU logic + export request PDU handling

This patch refactors existing traditional iscsi RX side PDU handling
to use iscsit_transport, and exports the necessary logic for external
transport modules.

This includes:

- Refactor iscsit_handle_scsi_cmd() into PDU setup / processing
- Add updated iscsit_handle_scsi_cmd() for tradtional iscsi code
- Add iscsit_set_unsoliticed_dataout() wrapper
- Refactor iscsit_handle_data_out() into PDU check / processing
- Add updated iscsit_handle_data_out() for tradtional iscsi code
- Add iscsit_handle_nop_out() + iscsit_handle_task_mgt_cmd() to
accept pre-allocated struct iscsi_cmd
- Add iscsit_build_r2ts_for_cmd() caller for iscsi_target_transport
to handle ISTATE_SEND_R2T for TX immediate queue
- Refactor main traditional iscsi iscsi_target_rx_thread() PDU switch
into iscsi_target_rx_opcode() using iscsit_allocate_cmd()
- Turn iscsi_target_rx_thread() process context into NOP for
ib_isert side work-queue.

v5 changes:

- Make iscsit_handle_scsi_cmd() static (Fengguang)
- Fix iscsit_handle_scsi_cmd() exception se_cmd leak (nab)

v3 changes:
- Add extra target_put_sess_cmd call in iscsit_add_reject_from_cmd
after completion

v2 changes:

- Disable iscsit_ack_from_expstatsn() usage for RDMAExtentions=Yes
- Disable iscsit_allocate_datain_req() usage for RDMAExtentions=Yes
- Add target_get_sess_cmd() reference counting to
iscsit_setup_scsi_cmd()
- Add TFO->lio_check_stop_free() fabric API caller
- Add export of iscsit_stop_dataout_timer() symbol
- Add iscsit_build_r2ts_for_cmd() for iscsit_transport->iscsit_get_dataout()
- Convert existing usage of iscsit_build_r2ts_for_cmd() to
->iscsit_get_dataout()
- Drop RDMAExtentions=Yes specific check in iscsit_build_r2ts_for_cmd()
- Fix RDMAExtentions -> RDMAExtensions typo (andy)
- Pass correct dump_payload value into iscsit_get_immediate_data()
for iscsit_handle_scsi_cmd()

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Initial traditional TCP conversion to iscsit_transport

This patch performs the initial conversion of existing traditional iscsi
to use iscsit_transport API callers. This includes:

- iscsi-np cleanups for iscsit_transport_type
- Add iscsi-np transport calls w/ ->iscsit_setup_up() and ->iscsit_free_np()
- Convert login thread process context to use ->iscsit_accept_np() for
connections with pre-allocated struct iscsi_conn
- Convert existing socket accept code to iscsit_accept_np()
- Convert login RX/TX callers to use ->iscsit_get_login_rx() and
->iscsit_put_login_tx() to exchange request/response PDUs
- Convert existing socket login RX/TX calls into iscsit_get_login_rx()
and iscsit_put_login_tx()
- Change iscsit_close_connection() to invoke ->iscsit_free_conn() +
iscsit_put_transport() calls.
- Add iscsit_register_transport() + iscsit_unregister_transport() calls
to module init/exit

v4 changes:

- Add missing iscsit_put_transport() call in iscsi_target_setup_login_socket()
failure case

v2 changes:

- Update module init/exit to use register_transport() + unregister_transport()

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target/iscsi: Use ISCSI_LOGIN_CURRENT/NEXT_STAGE macros

Fix bit-clearing in login_rsp->flags for case 0.

Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Always send a response before terminating iSCSI connection

There are some cases, for example when the initiator sends an
out-of-bounds ErrorRecoveryLevel value, where the iSCSI target
terminates the connection without sending back any error. Audit the
login path and add appropriate iscsit_tx_login_rsp() calls to make
sure this doesn't happen.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsit: proper endianess conversions

Make sure all on the wire types are use as big endian and big endian only so
that sparse can verify all the conversions are done right.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsit: use the itt_t abstract type

Use the special itt_t type defined by the iscsi headers and the initiator
to make sure it's an opaque value.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsit: mark various functions static

This patch marks a number of functions static to appease sparse static
checking.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Enable MaxXmitDataSegmentLength operation in login path

This patch activates MaxXmitDataSegmentLength usage that performs the
following sequence of events:

- Once the incoming initiator's MAXRECVDATASEGMENTLENGTH key is detected
within iscsi_check_acceptor_state(), save the requested MRDSL into
conn->conn_ops->MaxRecvDataSegmentLength

- Next change the outgoing target's MaxRecvDataSegmenthLength key=value
based upon the local TPG's MaxXmitDataSegmentLength attribute value.

- Change iscsi_set_connection_parameters() to skip the assignment of
conn->conn_ops->MaxRecvDataSegmentLength, now setup within
iscsi_check_acceptor_state()

Also update iscsi_decode_text_input() -> iscsi_check_acceptor_state()
code-path to accept struct iscsi_conn *.

Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Andy Grover <agrover@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target/iscsi: Don't log "iSCSI Login negotiation failed." twice

There's no need for iscsi_target_init_negotiation() to print

iSCSI Login negotiation failed.

on failure, since its only caller (__iscsi_target_login_thread())
prints exactly the same message if it gets an error return back.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: remove obvious warnings

Get rid of a bunch of write-only variables. In a number of cases I
suspect actual bugs to be present, so I left all of those for a second
look.

(nab: fix lio-core patch fuzz)

Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: Fix typo in drivers/target

Correct spelling "exeeds" to "exceeds" in iscsi/iscsi_target_nego.c
Correct spelling "diabled" to "disabled" in target_core_configfs.c

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: remove useless casts

A reader should spend an extra moment whenever noticing a cast,
because either something special is going on that deserves extra
attention or, as is all too often the case, the code is wrong.

These casts, afaics, have all been useless. They cast a foo* to a
foo*, cast a void* to the assigned type, cast a foo* to void*, before
assigning it to a void* variable, etc.

In a few cases I also removed an additional &...[0], which is equally
useless.

Lastly I added three FIXMEs where, to the best of my judgement, the
code appears to have a bug. It would be good if someone could check
these.

Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: header reshuffle, part2

This reorganized the headers under include/target into:

- target_core_base.h stays as is with all target-wide data stuctures and defines
- target_core_backend.h contains the whole interface to I/O backends
- target_core_fabric.h contains the whole interface to fabric modules

Except for those only the various configfs macro headers stay around.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Use kmemdup rather than duplicating its implementation

The semantic patch that makes this change is available
in scripts/coccinelle/api/memdup.cocci.

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

treewide: Correct spelling of successfully in comments

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

iscsi-target: Fix NULL dereference on allocation failure

This patch fixes a bug in iscsi_target_init_negotiation() where
the "goto out" path dereferences "login" which is NULL upon a
memory allocation failure.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Add iSCSI fabric support for target v4.1

The Linux-iSCSI.org target module is a full featured in-kernel
software implementation of iSCSI target mode (RFC-3720) for the
current WIP mainline target v4.1 infrastructure code for the v3.1
kernel. More information can be found here:

http://linux-iscsi.org/wiki/ISCSI

This includes support for:

* RFC-3720 defined request / response state machines and support for
all defined iSCSI operation codes from Section 10.2.1.2 using libiscsi
include/scsi/iscsi_proto.h PDU definitions
* Target v4.1 compatible control plane using the generic layout in
target_core_fabric_configfs.c and fabric dependent attributes
within /sys/kernel/config/target/iscsi/ subdirectories.
* Target v4.1 compatible iSCSI statistics based on RFC-4544 (iSCSI MIBS)
* Support for IPv6 and IPv4 network portals in M:N mapping to TPGs
* iSCSI Error Recovery Hierarchy support
* Per iSCSI connection RX/TX thread pair scheduling affinity
* crc32c + crc32c_intel SSEv4 instruction offload support using libcrypto
* CHAP Authentication support using libcrypto
* Conversion to use internal SGl allocation with iscsit_alloc_buffs() ->
transport_generic_map_mem_to_cmd()

(nab: Fix iscsi_proto.h struct scsi_lun usage from linux-next in commit:
iscsi: Use struct scsi_lun in iscsi structs instead of u8[8])
(nab: Fix 32-bit compile warnings)

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andy Grover <agrover@redhat.com>
Acked-by: Roland Dreier <roland@kernel.org>
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>