treewide: uapi: Replace zero-length arrays with flexible-array members

There is a regular need in the kernel to provide a way to declare
having a dynamically sized set of trailing elements in a structure.
Kernel code should always use “flexible array members”[1] for these
cases. The older style of one-element or zero-length arrays should
no longer be used[2].

This code was transformed with the help of Coccinelle:
(linux-5.19-rc2$ spatch --jobs $(getconf _NPROCESSORS_ONLN) --sp-file script.cocci --include-headers --dir . > output.patch)

@@
identifier S, member, array;
type T1, T2;
@@

struct S {
...
T1 member;
T2 array[
- 0
];
};

-fstrict-flex-arrays=3 is coming and we need to land these changes
to prevent issues like these in the short future:

../fs/minix/dir.c:337:3: warning: 'strcpy' will always overflow; destination buffer has size 0,
but the source string has length 2 (including NUL byte) [-Wfortify-source]
strcpy(de3->name, ".");
^

Since these are all [0] to [] changes, the risk to UAPI is nearly zero. If
this breaks anything, we can use a union with a new member name.

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays

Link: https://github.com/KSPP/linux/issues/78
Build-tested-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/62b675ec.wKX6AOZ6cbE71vtF%25lkp@intel.com/
Acked-by: Dan Williams <dan.j.williams@intel.com> # For ndctl.h
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

RDMA/cma: Provide ECE reject reason

IBTA declares "vendor option not supported" reject reason in REJ messages
if passive side doesn't want to accept proposed ECE options.

Due to the fact that ECE is managed by userspace, there is a need to let
users to provide such rejected reason.

Link: https://lore.kernel.org/r/20200526103304.196371-7-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA/cma: Connect ECE to rdma_accept

The rdma_accept() is called by both passive and active sides of CMID
connection to mark readiness to start data transfer. For passive side,
this is called explicitly, for active side, it is called implicitly while
receiving REP message.

Provide ECE data to rdma_accept function needed for passive side to send
that REP message.

Link: https://lore.kernel.org/r/20200526103304.196371-6-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA/ucma: Deliver ECE parameters through UCMA events

Passive side of CMID connection receives ECE request through REQ message
and needs to respond with relevant REP message which will be forwarded to
active side.

The UCMA events interface is responsible for such communication with the
user space (librdmacm). Extend it to provide ECE wire data.

Link: https://lore.kernel.org/r/20200526103304.196371-4-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA/ucma: Extend ucma_connect to receive ECE parameters

Active side of CMID initiates connection through librdmacm's
rdma_connect() and kernel's ucma_connect(). Extend UCMA interface to
handle those new parameters.

Link: https://lore.kernel.org/r/20200526103304.196371-3-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA/ucma: Return stable IB device index as identifier

The librdmacm uses node_guid as identifier to correlate between IB devices
and CMA devices. However FW resets cause to such "connection" to be lost
and require from the user to restart its application.

Extend UCMA to return IB device index, which is stable identifier.

Link: https://lore.kernel.org/r/20200504132541.355710-1-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

IB/cma: Define option to set ack timeout and pack tos_set

Define new option in 'rdma_set_option' to override calculated QP timeout
when requested to provide QP attributes to modify a QP.

At the same time, pack tos_set to be bitfield.

Signed-off-by: Danit Goldberg <danitg@mellanox.com>
Reviewed-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

uapi: Fix SPDX tags for files referring to the 'OpenIB.org' license

Based on discussion with Kate Stewart this license is not a
BSD-2-Clause, but is now formally identified as Linux-OpenIB
by SPDX.

The key difference between the licenses is in the 'warranty'
paragraph.

if_infiniband.h refers to the 'OpenIB.org' license, but
does not include the text, instead it links to an obsolete
web site that contains a license that matches the BSD-2-Clause
SPX. There is no 'three clause' version of the OpenIB.org
license.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Doug Ledford <dledford@redhat.com>

RDMA/CMA: Add rdma_port_space to UAPI

Since the rdma_port_space enum is being passed between user and kernel for
user cm_id setup, we need it in a UAPI header. So add it to
rdma_user_cm.h.

This also fixes the cm_id restrack changes which pass up the port space
value via the RDMA_NLDEV_ATTR_RES_PS attribute.

Fixes: 00313983cda6 ("RDMA/nldev: provide detailed CM_ID information")
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA: Change all uapi headers to use __aligned_u64 instead of __u64

The new auditing standard for the subsystem will be to only use
__aligned_64 in uapi headers to try and prevent 32/64 compat bugs
from existing in the future.

Changing all existing usage will help ensure new developers copy the
right idea.

The before/after of this patch was tested using pahole on 32 and 64
bit compiles to confirm it has no change in the structure layout, so
this patch is a NOP.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA/ucma: Fix uABI structure layouts for 32/64 compat

The rdma_ucm_event_resp is a different length on 32 and 64 bit compiles.

The kernel requires it to be the expected length or longer so 32 bit
builds running on a 64 bit kernel will not work.

Retain full compat by having all kernels accept a struct with or without
the trailing reserved field.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

License cleanup: add SPDX license identifier to uapi header files with a license

Many user space API headers have licensing information, which is either
incomplete, badly formatted or just a shorthand for referring to the
license under which the file is supposed to be. This makes it hard for
compliance tools to determine the correct license.

Update these files with an SPDX license identifier. The identifier was
chosen based on the license information in the file.

GPL/LGPL licensed headers get the matching GPL/LGPL SPDX license
identifier with the added 'WITH Linux-syscall-note' exception, which is
the officially assigned exception identifier for the kernel syscall
exception:

NOTE! This copyright does *not* cover user programs that use kernel
services by normal system calls - this is merely considered normal use
of the kernel, and does *not* fall under the heading of "derived work".

This exception makes it possible to include GPL headers into non GPL
code, without confusing license compliance tools.

Headers which have either explicit dual licensing or are just licensed
under a non GPL license are updated with the corresponding SPDX
identifier and the GPLv2 with syscall exception identifier. The format
is:
((GPL-2.0 WITH Linux-syscall-note) OR SPDX-ID-OF-OTHER-LICENSE)

SPDX license identifiers are a legally binding shorthand, which can be
used instead of the full boiler plate text. The update does not remove
existing license information as this has to be done on a case by case
basis and the copyright holders might have to be consulted. This will
happen in a separate step.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne. See the previous patch in this series for the
methodology of how this patch was researched.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

rdma UAPI: Use __kernel_sockaddr_storage

The kernel side is #ifdef'd to this type, and the UAPI header
should use it directly. It has slightly different alignment
requirments from the usual user space version.

Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

IB/core: Support for CMA multicast join flags

Added UCMA and CMA support for multicast join flags. Flags are
passed using UCMA CM join command previously reserved fields.
Currently supporting two join flags indicating two different
multicast JoinStates:

1. Full Member:
The initiator creates the Multicast group(MCG) if it wasn't
previously created, can send Multicast messages to the group
and receive messages from the MCG.

2. Send Only Full Member:
The initiator creates the Multicast group(MCG) if it wasn't
previously created, can send Multicast messages to the group
but doesn't receive any messages from the MCG.

IB: Send Only Full Member requires a query of ClassPortInfo
to determine if SM/SA supports this option. If SM/SA
doesn't support Send-Only there will be no join request
sent and an error will be returned.

ETH: When Send Only Full Member is requested no IGMP join
will be sent.

Signed-off-by: Alex Vesker <valex@mellanox.com>
Reviewed by: Hal Rosenstock <hal@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>

RDMA/uapi: Include socket.h in rdma_user_cm.h

added struct sockaddr_storage to rdma_user_cm.h without also adding an
include for linux/socket.h to make sure it is defined. Systemtap
needs the header files to build standalone and cannot rely on other
files to pre-include other headers, so add linux/socket.h to the list
of includes in this file.

Fixes: ee7aed4528f ("RDMA/ucma: Support querying for AF_IB addresses")
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

RDMA/ucma: Allow user space to specify AF_IB when joining multicast

Allow user space applications to join multicast groups using MGIDs
directly. MGIDs may be passed using AF_IB addresses. Since the
current multicast join command only supports addresses as large as
sockaddr_in6, define a new structure for joining addresses specified
using sockaddr_ib.

Since AF_IB allows the user to specify the qkey when resolving a
remote UD QP address, when joining the multicast group use the qkey
value, if one has been assigned.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

RDMA/ucma: Allow user space to pass AF_IB into resolve

Allow user space applications to call resolve_addr using AF_IB. To
support sockaddr_ib, we need to define a new structure capable of
handling the larger address size.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

RDMA/ucma: Allow user space to bind to AF_IB

Support user space binding to addresses using AF_IB. Since
sockaddr_ib is larger than sockaddr_in6, we need to define a larger
structure when binding using AF_IB. This time we use sockaddr_storage
to cover future cases.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

RDMA/ucma: Name changes to indicate only IP addresses supported

Several commands into the RDMA CM from user space are restricted to
supporting addresses which fit into a sockaddr_in6 structure: bind
address, resolve address, and join multicast.

With the addition of AF_IB, we need to support addresses which are
larger than sockaddr_in6. This will be done by adding new commands
that exchange address information using sockaddr_storage. However, to
support existing applications, we maintain the current commands and
structures, but rename them to indicate that they only support IPv4
and v6 addresses.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

RDMA/ucma: Add ability to query GID addresses

Part of address resolution is mapping IP addresses to IB GIDs. With
the changes to support querying larger addresses and more path records,
also provide a way to query IB GIDs after resolution completes.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

RDMA/ucma: Support querying when IB paths are not reversible

The current query_route call can return up to two path records. The
assumption being that one is the primary path, with optional support
for an alternate path. In both cases, the paths are assumed to be
reversible and are used to send CM MADs.

With the ability to manually set IB path data, the rdma cm can
eventually be capable of using up to 6 paths per connection:

forward primary, reverse primary,
forward alternate, reverse alternate,
reversible primary path for CM MADs
reversible alternate path for CM MADs.

(It is unclear at this time if IB routing will complicate this) In
order to handle more flexible routing topologies, add a new command to
report any number of paths.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

RDMA/ucma: Support querying for AF_IB addresses

The sockaddr structure for AF_IB is larger than sockaddr_in6. The
rdma cm user space ABI uses the latter to exchange address information
between user space and the kernel.

To support querying for larger addresses, define a new query command
that exchanges data using sockaddr_storage, rather than sockaddr_in6.
Unlike the existing query_route command, the new command only returns
address information. Route (i.e. path record) data is separated.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

RDMA/cma: Set qkey for AF_IB

Allow the user to specify the qkey when using AF_IB. The qkey is
added to struct rdma_ucm_conn_param in place of a reserved field, but
for backwards compatability, is only accessed if the associated
rdma_cm_id is using AF_IB.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

UAPI: (Scripted) Disintegrate include/rdma

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>