Commit Graph

13 Commits

Author SHA1 Message Date
Vivek Goyal
061624455f virtiofsd: Fix fuse setxattr() API change issue
With kernel header updates fuse_setxattr_in struct has grown in size.
But this new struct size only takes affect if user has opted in
for fuse feature FUSE_SETXATTR_EXT otherwise fuse continues to
send "fuse_setxattr_in" of older size. Older size is determined
by FUSE_COMPAT_SETXATTR_IN_SIZE.

Fix this. If we have not opted in for FUSE_SETXATTR_EXT, then
expect that we will get fuse_setxattr_in of size FUSE_COMPAT_SETXATTR_IN_SIZE
and not sizeof(struct fuse_sexattr_in).

Fixes: 278f064e45 ("Update Linux headers to 5.13-rc4")
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Message-Id: <20210622150852.1507204-2-vgoyal@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2021-07-05 10:51:26 +01:00
Vivek Goyal
d64907acbf viriofsd: Add support for FUSE_HANDLE_KILLPRIV_V2
This patch adds basic support for FUSE_HANDLE_KILLPRIV_V2. virtiofsd
can enable/disable this by specifying option "-o killpriv_v2/no_killpriv_v2".
By default this is enabled as long as client supports it

Enabling this option helps with performance in write path. Without this
option, currently every write is first preceeded with a getxattr() operation
to find out if security.capability is set. (Write is supposed to clear
security.capability). With this option enabled, server is signing up for
clearing security.capability on every WRITE and also clearing suid/sgid
subject to certain rules. This gets rid of extra getxattr() call for every
WRITE and improves performance. This is true when virtiofsd is run with
option -o xattr.

What does enabling FUSE_HANDLE_KILLPRIV_V2 mean for file server implementation.
It needs to adhere to following rules. Thanks to Miklos for this summary.

- clear "security.capability" on write, truncate and chown unconditionally
- clear suid/sgid in case of following. Note, sgid is cleared only if
  group executable bit is set.
    o setattr has FATTR_SIZE and FATTR_KILL_SUIDGID set.
    o setattr has FATTR_UID or FATTR_GID
    o open has O_TRUNC and FUSE_OPEN_KILL_SUIDGID
    o create has O_TRUNC and FUSE_OPEN_KILL_SUIDGID flag set.
    o write has FUSE_WRITE_KILL_SUIDGID

>From Linux VFS client perspective, here are the requirements.

- caps are always cleared on chown/write/truncate
- suid is always cleared on chown, while for truncate/write it is cleared
  only if caller does not have CAP_FSETID.
- sgid is always cleared on chown, while for truncate/write it is cleared
  only if caller does not have CAP_FSETID as well as file has group execute
  permission.

virtiofsd implementation has not changed much to adhere to above ruls. And
reason being that current assumption is that we are running on Linux
and on top of filesystems like ext4/xfs which already follow above rules.
On write, truncate, chown, seucurity.capability is cleared. And virtiofsd
drops CAP_FSETID if need be and that will lead to clearing of suid/sgid.

But if virtiofsd is running on top a filesystem which breaks above assumptions,
then it will have to take extra actions to emulate above. That's a TODO
for later when need arises.

Note: create normally is supposed to be called only when file does not
      exist. So generally there should not be any question of clearing
      setuid/setgid. But it is possible that after client checks that
      file is not present, some other client creates file on server
      and this race can trigger sending FUSE_CREATE. In that case, if
      O_TRUNC is set, we should clear suid/sgid if FUSE_OPEN_KILL_SUIDGID
      is also set.

v3:
  - Resolved conflicts due to lo_inode_open() changes.
  - Moved capability code in lo_do_open() so that both lo_open() and
    lo_create() can benefit from common code.
  - Dropped changes to kernel headers as these are part of qemu already.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20210208224024.43555-3-vgoyal@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2021-02-16 17:03:09 +00:00
Marc-André Lureau
db5deef996 virtiofsd: replace _Static_assert with QEMU_BUILD_BUG_ON
This allows to get rid of a check for older GCC version (which was a bit
bogus too since it was falling back on c++ version..)

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20201210134752.780923-7-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 12:52:10 -05:00
Markus Armbruster
4bd802b209 Clean up includes
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.

This commit was created with scripts/clean-includes, with the changes
to the following files manually reverted:

    contrib/libvhost-user/libvhost-user-glib.h
    contrib/libvhost-user/libvhost-user.c
    contrib/libvhost-user/libvhost-user.h
    contrib/plugins/hotblocks.c
    contrib/plugins/hotpages.c
    contrib/plugins/howvec.c
    contrib/plugins/lockstep.c
    linux-user/mips64/cpu_loop.c
    linux-user/mips64/signal.c
    linux-user/sparc64/cpu_loop.c
    linux-user/sparc64/signal.c
    linux-user/x86_64/cpu_loop.c
    linux-user/x86_64/signal.c
    target/s390x/gen-features.c
    tests/fp/platform.h
    tests/migration/s390x/a-b-bios.c
    tests/plugin/bb.c
    tests/plugin/empty.c
    tests/plugin/insn.c
    tests/plugin/mem.c
    tests/test-rcu-simpleq.c
    tests/test-rcu-slist.c
    tests/test-rcu-tailq.c
    tests/uefi-test-tools/UefiTestToolsPkg/BiosTablesTest/BiosTablesTest.c

contrib/plugins/, tests/plugin/, and tests/test-rcu-slist.c appear not
to include osdep.h intentionally.  The remaining reverts are the same
as in commit bbfff19688.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20201113061216.2483385-1-armbru@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Tested-by: Thomas Huth <thuth@redhat.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Alexander Bulekov <alxndr@bu.edu>
2020-12-10 17:16:44 +01:00
Max Reitz
9c6ac04363 virtiofsd: Check FUSE_SUBMOUNTS
FUSE_SUBMOUNTS is a pure indicator by the kernel to signal that it
supports submounts.  It does not check its state in the init reply, so
there is nothing for fuse_lowlevel.c to do but to check its existence
and copy it into fuse_conn_info.capable.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20201102161859.156603-2-mreitz@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2020-11-02 19:22:06 +00:00
Alex Williamson
33dc9914ea Revert series: virtiofsd: Announce submounts to the guest
This reverts the following commits due to their basis on a bogus
linux kernel header update:

c93a656f7b ("tests/acceptance: Add virtiofs_submounts.py")
45ced7ca2f ("tests/acceptance/boot_linux: Accept SSH pubkey")
08dce386e7 ("virtiofsd: Announce sub-mount points")
eba8b096c1 ("virtiofsd: Store every lo_inode's parent_dev")
ede24b6be7 ("virtiofsd: Add fuse_reply_attr_with_flags()")
e2577435d3 ("virtiofsd: Add attr_flags to fuse_entry_param")
2f10415abf ("virtiofsd: Announce FUSE_ATTR_FLAGS")
97d741cc96 ("linux/fuse.h: Pull in from Linux")

Cc: Max Reitz <mreitz@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 160385090886.20017.13382256442750027666.stgit@gimli.home
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-10-28 13:17:32 +00:00
Max Reitz
2f10415abf virtiofsd: Announce FUSE_ATTR_FLAGS
The fuse_attr.flags field is currently just initialized to 0, which is
valid.  Thus, there is no reason not to always announce FUSE_ATTR_FLAGS
(when the kernel supports it).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200909184028.262297-3-mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2020-10-26 18:35:32 +00:00
Vivek Goyal
f779bc5265 virtiofsd: Parse flag FUSE_WRITE_KILL_PRIV
Caller can set FUSE_WRITE_KILL_PRIV in write_flags. Parse it and pass it
to the filesystem.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2020-01-23 16:41:37 +00:00
Stefan Hajnoczi
dad157e880 virtiofsd: add fuse_mbuf_iter API
Introduce an API for consuming bytes from a buffer with size checks.
All FUSE operations will be converted to use this safe API instead of
void *inarg.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2020-01-23 16:41:36 +00:00
Xiao Yang
8c3fe75e03 virtiofsd: Remove unused enum fuse_buf_copy_flags
Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2020-01-23 16:41:36 +00:00
Dr. David Alan Gilbert
7387863d03 virtiofsd: Format imported files to qemu style
Mostly using a set like:

indent -nut -i 4 -nlp -br -cs -ce --no-space-after-function-call-names file
clang-format -style=file -i -- file
clang-tidy -fix-errors -checks=readability-braces-around-statements file
clang-format -style=file -i -- file

With manual cleanups.

The .clang-format used is below.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed by: Aleksandar Markovic <amarkovic@wavecomp.com>

Language:        Cpp
AlignAfterOpenBracket: Align
AlignConsecutiveAssignments: false # although we like it, it creates churn
AlignConsecutiveDeclarations: false
AlignEscapedNewlinesLeft: true
AlignOperands:   true
AlignTrailingComments: false # churn
AllowAllParametersOfDeclarationOnNextLine: true
AllowShortBlocksOnASingleLine: false
AllowShortCaseLabelsOnASingleLine: false
AllowShortFunctionsOnASingleLine: None
AllowShortIfStatementsOnASingleLine: false
AllowShortLoopsOnASingleLine: false
AlwaysBreakAfterReturnType: None # AlwaysBreakAfterDefinitionReturnType is taken into account
AlwaysBreakBeforeMultilineStrings: false
BinPackArguments: true
BinPackParameters: true
BraceWrapping:
  AfterControlStatement: false
  AfterEnum:       false
  AfterFunction:   true
  AfterStruct:     false
  AfterUnion:      false
  BeforeElse:      false
  IndentBraces:    false
BreakBeforeBinaryOperators: None
BreakBeforeBraces: Custom
BreakBeforeTernaryOperators: false
BreakStringLiterals: true
ColumnLimit:     80
ContinuationIndentWidth: 4
Cpp11BracedListStyle: false
DerivePointerAlignment: false
DisableFormat:   false
ForEachMacros:   [
  'CPU_FOREACH',
  'CPU_FOREACH_REVERSE',
  'CPU_FOREACH_SAFE',
  'IOMMU_NOTIFIER_FOREACH',
  'QLIST_FOREACH',
  'QLIST_FOREACH_ENTRY',
  'QLIST_FOREACH_RCU',
  'QLIST_FOREACH_SAFE',
  'QLIST_FOREACH_SAFE_RCU',
  'QSIMPLEQ_FOREACH',
  'QSIMPLEQ_FOREACH_SAFE',
  'QSLIST_FOREACH',
  'QSLIST_FOREACH_SAFE',
  'QTAILQ_FOREACH',
  'QTAILQ_FOREACH_REVERSE',
  'QTAILQ_FOREACH_SAFE',
  'QTAILQ_RAW_FOREACH',
  'RAMBLOCK_FOREACH'
]
IncludeCategories:
  - Regex:           '^"qemu/osdep.h'
    Priority:        -3
  - Regex:           '^"(block|chardev|crypto|disas|exec|fpu|hw|io|libdecnumber|migration|monitor|net|qapi|qemu|qom|standard-headers|sysemu|ui)/'
    Priority:        -2
  - Regex:           '^"(elf.h|qemu-common.h|glib-compat.h|qemu-io.h|trace-tcg.h)'
    Priority:        -1
  - Regex:           '.*'
    Priority:        1
IncludeIsMainRegex: '$'
IndentCaseLabels: false
IndentWidth:     4
IndentWrappedFunctionNames: false
KeepEmptyLinesAtTheStartOfBlocks: false
MacroBlockBegin: '.*_BEGIN$' # only PREC_BEGIN ?
MacroBlockEnd:   '.*_END$'
MaxEmptyLinesToKeep: 2
PointerAlignment: Right
ReflowComments:  true
SortIncludes:    true
SpaceAfterCStyleCast: false
SpaceBeforeAssignmentOperators: true
SpaceBeforeParens: ControlStatements
SpaceInEmptyParentheses: false
SpacesBeforeTrailingComments: 1
SpacesInContainerLiterals: true
SpacesInParentheses: false
SpacesInSquareBrackets: false
Standard:        Auto
UseTab:          Never
...

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2020-01-23 16:41:36 +00:00
Dr. David Alan Gilbert
a3e23f3254 virtiofsd: Trim down imported files
There's a lot of the original fuse code we don't need; trim them down.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
with additional trimming by:
Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2020-01-23 16:41:36 +00:00
Dr. David Alan Gilbert
ee46c78901 virtiofsd: Pull in upstream headers
Pull in headers fromlibfuse's upstream fuse-3.8.0

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2020-01-23 16:41:36 +00:00