um: Convert strscpy() usage to 2-argument style

The ARCH=um build has its own idea about strscpy()'s definition. Adjust
the callers to remove the redundant sizeof() arguments ahead of treewide
changes, since it needs a manual adjustment for the newly named
sized_strscpy() export.

Cc: Richard Weinberger <richard@nod.at>
Cc: linux-um@lists.infradead.org
Signed-off-by: Kees Cook <keescook@chromium.org>

um: vector: refactor deprecated strncpy

`strncpy` is deprecated for use on NUL-terminated destination strings [1].

A suitable replacement is `strscpy` [2] due to the fact that it
guarantees NUL-termination on its destination buffer argument which is
_not_ the case for `strncpy`!

In this case, we are able to drop the now superfluous `... - 1`
instances because `strscpy` will automatically truncate the last byte by
setting it to a NUL byte if the source size exceeds the destination size
or if the source string is not NUL-terminated.

I've also opted to remove the seemingly useless char* casts. I'm not
sure why they're present at all since (after expanding the `ifr_name`
macro) `ifr.ifr_ifrn.ifrn_name` is a char* already.

All in all, `strscpy` is a more robust and less ambiguous interface
while also letting us remove some `... -1`'s which cleans things up a
bit.

[1]: www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings
[2]: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html

Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Justin Stitt <justinstitt@google.com>
Acked-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

um: vector: refactor deprecated strncpy

`strncpy` is deprecated for use on NUL-terminated destination strings [1].

A suitable replacement is `strscpy` [2] due to the fact that it
guarantees NUL-termination on its destination buffer argument which is
_not_ the case for `strncpy`!

In this case, we are able to drop the now superfluous `... - 1`
instances because `strscpy` will automatically truncate the last byte by
setting it to a NUL byte if the source size exceeds the destination size
or if the source string is not NUL-terminated.

I've also opted to remove the seemingly useless char* casts. I'm not
sure why they're present at all since (after expanding the `ifr_name`
macro) `ifr.ifr_ifrn.ifrn_name` is a char* already.

All in all, `strscpy` is a more robust and less ambiguous interface
while also letting us remove some `... -1`'s which cleans things up a
bit.

[1]: www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings
[2]: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html

Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Justin Stitt <justinstitt@google.com>
Acked-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Link: https://lore.kernel.org/r/20230807-arch-um-drivers-v1-1-10d602c5577a@google.com
Signed-off-by: Kees Cook <keescook@chromium.org>

uml: net: vector: fix const issue

Since the constification of MAC addresses, the argument
to uml_vector_default_bpf() must be const.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: anton ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

isystem: trim/fixup stdarg.h and other headers

Delete/fixup few includes in anticipation of global -isystem compile
option removal.

Note: crypto/aegis128-neon-inner.c keeps <stddef.h> due to redefinition
of uintptr_t error (one definition comes from <stddef.h>, another from
<linux/types.h>).

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

um: vector: Add dynamic tap interfaces and scripting

Provide functionality roughly compatible with the existing qemu
ifup scripting:
* invocation of an ifup script. The interface name is passed as the
first and only argument
* allocating tap interfaces on the fly if they are not explicitly
specified

Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

um: Remove redundant NULL check

Fix below warnings reported by coccicheck:
./arch/um/drivers/vector_user.c:403:2-7: WARNING: NULL check before some freeing functions is not needed.

Fixes: bc8f8e4e6e7a ("um: Add a generic "fd" vector transport")
Signed-off-by: Li Heng <liheng40@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

um: Some fixes to build UML with musl

musl toolchain and headers are a bit more strict. These fixes enable building
UML with musl as well as seem not to break on glibc.

Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

um: Fix null pointer dereference in vector_user_bpf

The bpf_prog is being checked for !NULL after uml_kmalloc
but later its used directly for example:
bpf_prog->filter = bpf and is also later returned upon
success. Fix this, do a NULL check and return right away.

Signed-off-by: Gaurav Singh <gaurav1086@gmail.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

um: Add a generic "fd" vector transport

Learn to take a pre-opened file-descriptor for vector IO.

Instead of teaching the driver to open a FD in multiple ways, it can
rely on management layer to do it on its behalf. For example, this
allows inheriting a preconfigured device fd or a simple socketpair()
setup, without further arguments, privileges or system access by UML.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

um: Remove some unnecessary NULL checks in vector_user.c

kfree() already checks for null pointers, so additional checking is
unnecessary.

Signed-off-by: Alex Dewar <alex.dewar@gmx.co.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

um: Loadable BPF "Firmware" for vector drivers

All vector drivers now allow a BPF program to be loaded and
associated with the RX socket in the host kernel.

1. The program can be loaded as an extra kernel command line
option to any of the vector drivers.

2. The program can also be loaded as "firmware", using the
ethtool flash option. It is possible to turn this facility
on or off using a command line option.

A simplistic wrapper for generating the BPF firmware for the raw
socket driver out of a tcpdump/libpcap filter expression can be
found at: https://github.com/kot-begemot-uk/uml_vector_utilities/

Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

um: Add SPDX headers for files in arch/um/drivers

Convert files to use SPDX header. All files are licensed under the GPLv2.

Signed-off-by: Alex Dewar <alex.dewar@gmx.co.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

um: Error handling fixes in vector drivers

With the addition of bess support which uses connection
oriented SEQPACKET sockets the vector routines can now
encounter a "remote end closed the connection" scenario.

This adds handling code to detect it in the TX path and
the legacy RX path. There is no way to detect it in the
vector RX path because that can legitimately return 0
even if the remote end has not closed the connection. As
a result the detection is delayed until the first TX
event after the close.

Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

um: Added support for unix socket transports and bess transport

This adds support for the UNIX domain socket transports in
general and implements a Netsys::BESS compatible transport
interface.
For details on Netsys::BESS see https://github.com/NetSys/bess

Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

um: Add legacy tap support and rename existing vector to hybrid

1. Adds legacy tap support
2. Renames tap+raw as hybrid

Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

um: Remove duplicated include from vector_user.c

Remove duplicated include.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Acked-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

um: writev needs <sys/uio.h>

vector_user.c doesn't compile without this for me.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Richard Weinberger <richard@nod.at>

um: Include sys/uio.h to have writev()

sys/uio.h gives us writev(), otherwise the build might fail on
some systems.

Fixes: 49da7e64f33e ("High Performance UML Vector Network Driver")
Signed-off-by: Richard Weinberger <richard@nod.at>

um: NULL check before kfree is not needed

kfree(NULL) is safe,so this removes NULL check before freeing the mem

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

Fix vector raw inintialization logic

Vector RAW in UML needs to BPF filter its own MAC only
if QDISC_BYPASS has failed. If QDISC_BYPASS is successful, the
frames originated locally are not visible to readers on the
raw socket.

Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

High Performance UML Vector Network Driver

1. Provides infrastructure for vector IO using recvmmsg/sendmmsg.
1.1. Multi-message read.
1.2. Multi-message write.
1.3. Optimized queue support for multi-packet enqueue/dequeue.
1.4. BQL/DQL support.
2. Implements transports for several transports as well support
for direct wiring of PWEs to NIC. Allows direct connection of VMs
to host, other VMs and network devices with no switch in use.
2.1. Raw socket >4 times higher PPS and 10 times higher tcp RX
than existing pcap based transport (> 4Gbit)
2.2. New tap transport using socket RX and tap xmit. Similar
performance improvements (>4Gbit)
2.3. GRE transport - direct wiring to GRE PWE
2.4. L2TPv3 transport - direct wiring to L2TPv3 PWE
3. Tuning, performance and offload related setting support via ethtool.
4. Initial BPF support - used in tap/raw to avoid software looping
5. Scatter Gather support.
6. VNET and checksum offload support for raw socket transport.
7. TSO/GSO support where applicable or available
8. Migrates all error messages to netdevice_*() and rate limits
them where needed.

Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>