This previous commit introduced a simpler free callback for
hash data with only 1 arg, the value to free:
commit 49288fac96
Author: Peter Krempa <pkrempa@redhat.com>
Date: Wed Oct 9 15:26:37 2019 +0200
util: hash: Add possibility to use simpler data free function in virHash
It missed two functions in the hash table code which need
to call the alternate data free function, virHashRemoveEntry
and virHashRemoveSet.
After the previous patch though, there is no code that
makes functional use of the 2nd key arg in the data
free function. There is merely one log message that can
be dropped.
We can thus purge the current virHashDataFree callback
entirely, and rename virHashDataFreeSimple to replace
it.
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Add a helper that checks whether an entry with given name exists but
does not touch the userdata.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
ACKed-by: Eric Blake <eblake@redhat.com>
Add a simpler constructor for hash tables which specifically does not
require specifying the initial hash size and uses simpler freeing
function.
The initial hash table size usually is not important as the hash table
is growing when it reaches certain number of entries in one bucket.
Additionally many callers pass in a random small number for ad-hoc table
use so using a central one will simplify things.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
ACKed-by: Eric Blake <eblake@redhat.com>
Introduce a new type virHashDataFreeSimple which has only a void * as
argument for cases when knowing the name of the entry when freeing the
hash entry is not required.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
ACKed-by: Eric Blake <eblake@redhat.com>
Replace all the occurrences of
ignore_value(VIR_STRDUP(a, b));
with
a = g_strdup(b);
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Use G_GNUC_UNUSED from GLib instead of ATTRIBUTE_UNUSED.
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
In cases when the hash function for a name collides with other entry
already in the hash we prepend to the bucket. This creates a 'stack
effect' on the buckets if we then iterate through the hash. Normally
this is not a problem, but in tests we want deterministic results.
Since it does not matter where we add the entry and it's usually more
probable that a different entry will be accessed next change it to
append to the end of the bucket. Luckily we already iterate throught the
bucket once thus we can easily find the last entry and just connect the
new entry after it.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
'viralloc.h' does not provide any type or macro which would be necessary
in headers. Prevent leakage of the inclusion.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Missing semicolon at the end of macros can confuse some analyzers
(like cppcheck <filename>). VIR_ONCE_GLOBAL_INIT is almost
exclusively called without an ending semicolon, but let's
standardize on using one like the other macros.
Add a dummy struct definition at the end of the macro, so
the compiler will require callers to add a semicolon.
Reviewed-by: John Ferlan <jferlan@redhat.com>
Signed-off-by: Cole Robinson <crobinso@redhat.com>
In many files there are header comments that contain an Author:
statement, supposedly reflecting who originally wrote the code.
In a large collaborative project like libvirt, any non-trivial
file will have been modified by a large number of different
contributors. IOW, the Author: comments are quickly out of date,
omitting people who have made significant contribitions.
In some places Author: lines have been added despite the person
merely being responsible for creating the file by moving existing
code out of another file. IOW, the Author: lines give an incorrect
record of authorship.
With this all in mind, the comments are useless as a means to identify
who to talk to about code in a particular file. Contributors will always
be better off using 'git log' and 'git blame' if they need to find the
author of a particular bit of code.
This commit thus deletes all Author: comments from the source and adds
a rule to prevent them reappearing.
The Copyright headers are similarly misleading and inaccurate, however,
we cannot delete these as they have legal meaning, despite being largely
inaccurate. In addition only the copyright holder is permitted to change
their respective copyright statement.
Reviewed-by: Erik Skultety <eskultet@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
All of the ones being removed are pulled in by internal.h. The only
exception is sanlock which expects the application to include <stdint.h>
before sanlock's headers, because sanlock prototypes use fixed width
int, but they don't include stdint.h themselves, so we have to leave
that one in place.
Signed-off-by: Erik Skultety <eskultet@redhat.com>
Acked-by: Michal Privoznik <mprivozn@redhat.com>
Using the new VIR_DEFINE_AUTOPTR_FUNC macro defined in
src/util/viralloc.h, define a new wrapper around an existing
cleanup function which will be called when a variable declared
with VIR_AUTOPTR macro goes out of scope. Also, drop the redundant
viralloc.h include, since that has moved from the source module into
the header.
When variables of type virHashTablePtr are declared using
VIR_AUTOPTR, the function virHashFree will be run
automatically on it when it goes out of scope.
Signed-off-by: Sukrit Bhatnagar <skrtbhtngr@gmail.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>
So far we are repeating the following lines over and over:
if (!(virSomeObjectClass = virClassNew(virClassForObject(),
"virSomeObject",
sizeof(virSomeObject),
virSomeObjectDispose)))
return -1;
While this works, it is impossible to do some checking. Firstly,
the class name (the 2nd argument) doesn't match the name in the
code in all cases (the 3rd argument). Secondly, the current style
is needlessly verbose. This commit turns example into following:
if (!(VIR_CLASS_NEW(virSomeObject,
virClassForObject)))
return -1;
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
This is the responsability of the caller to apply the correct lock
before using these functions. Moreover, the use of a simple boolean
was still racy: two threads may check the boolean and "lock" it
simultaneously.
Users of functions from src/util/virhash.c have to be checked for
correctness. Lookups and iteration should hold a RO
lock. Modifications should hold a RW lock.
Most important uses seem to be covered. Callers have now a greater
responsability, notably the ability to execute some operations while
iterating were reliably forbidden before are now accepted.
Signed-off-by: Vincent Bernat <vincent@bernat.im>
Right-aligning backslashes when defining macros or using complex
commands in Makefiles looks cute, but as soon as any changes is
required to the code you end up with either distractingly broken
alignment or unnecessarily big diffs where most of the changes
are just pushing all backslashes a few characters to one side.
Generated using
$ git grep -El '[[:blank:]][[:blank:]]\\$' | \
grep -E '*\.([chx]|am|mk)$$' | \
while read f; do \
sed -Ei 's/[[:blank:]]*[[:blank:]]\\$/ \\/g' "$f"; \
done
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
While searching for an element using a function it may be
desirable to know the element key for future operation.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
The method will now return 0 on success and -1 on error, rather than number of
items which it iterated over before it returned back to the caller. Since the
only place where we actually check the number of elements iterated is in
virhashtest, return value of 0 and -1 can be a pretty accurate hint that it
iterated over all the items. However, if we really want to know the number of
items iterated over (like virhashtest does), a counter has to be provided
through opaque data to each iterator call. This patch adjusts return value of
virHashForEach, refactors the body, so it returns as soon as one of the
iterators fail and adjusts virhashtest to reflect these changes.
Signed-off-by: Erik Skultety <eskultet@redhat.com>
Our existing virHashForEach method iterates through all items disregarding the
fact, that some of the iterators might have actually failed. Errors are usually
dispatched through an error element in opaque data which then causes the
original caller of virHashForEach to return -1. In that case, virHashForEach
could return as soon as one of the iterators fail. This patch changes the
iterator return type and adjusts all of its instances accordingly, so the
actual refactor of virHashForEach method can be dealt with later.
Signed-off-by: Erik Skultety <eskultet@redhat.com>
VIR_DEBUG and VIR_WARN will automatically add a new line to the message,
having "\n" at the end or at the beginning of the message results in
empty lines.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
If this function fails, the error message is reported only in
some cases (e.g. OOM), but in some it's not (e.g. duplicate key).
This fact is painful and we should either not report error at all
or report the error in all possible cases. I vote for the latter.
Unfortunately, since the key may be an arbitrary value (not
necessarily a string) we can't report it in the error message.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
In 9190f0b0 we've tried to fix an OOM. And boy, was that fix
successful. But back then, the hash table implementation worked
strictly over string keys, which is not the case anymore. Hash
table have this function keyCopy() which returns void *.
Therefore a local variable that is temporarily holding the
intermediate return value from that function should be void *
too.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
This is a self-locking wrapper around virHashTable. Only a limited set
of APIs are implemented now (the ones which are used in the following
patch) as more can be added on demand.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
I almost wrote a hash value free function that just called
VIR_FREE, then realized I couldn't be the first person to
do that. Sure enough, it was worth factoring into a common
helper routine.
* src/util/virhash.h (virHashValueFree): New function.
* src/util/virhash.c (virHashValueFree): Implement it.
* src/util/virobject.h (virObjectFreeHashData): New function.
* src/libvirt_private.syms (virhash.h, virobject.h): Export them.
* src/nwfilter/nwfilter_learnipaddr.c (virNWFilterLearnInit): Use
common function.
* src/qemu/qemu_capabilities.c (virQEMUCapsCacheNew): Likewise.
* src/qemu/qemu_command.c (qemuDomainCCWAddressSetCreate):
Likewise.
* src/qemu/qemu_monitor.c (qemuMonitorGetBlockInfo): Likewise.
* src/qemu/qemu_process.c (qemuProcessWaitForMonitor): Likewise.
* src/util/virclosecallbacks.c (virCloseCallbacksNew): Likewise.
* src/util/virkeyfile.c (virKeyFileParseGroup): Likewise.
* tests/qemumonitorjsontest.c
(testQemuMonitorJSONqemuMonitorJSONGetBlockInfo): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Any source file which calls the logging APIs now needs
to have a VIR_LOG_INIT("source.name") declaration at
the start of the file. This provides a static variable
of the virLogSource type.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
'const fooPtr' is the same as 'foo * const' (the pointer won't
change, but it's contents can). But in general, if an interface
is trying to be const-correct, it should be using 'const foo *'
(the pointer is to data that can't be changed).
Fix up virhash to provide a const-correct interface: all actions
that don't modify the table take a const table. Note that in
one case (virHashSearch), we actually strip const away - we aren't
modifying the contents of the table, so much as associated data
for ensuring that the code uses the table correctly (if this were
C++, it would be a case for the 'mutable' keyword).
* src/util/virhash.h (virHashKeyComparator, virHashEqual): Use
intended type.
(virHashSize, virHashTableSize, virHashLookup, virHashSearch):
Make const-correct.
* src/util/virhash.c (virHashEqualData, virHashEqual)
(virHashLookup, virHashSize, virHashTableSize, virHashSearch)
(virHashComputeKey): Fix fallout.
* src/conf/nwfilter_params.c
(virNWFilterFormatParameterNameSorter): Likewise.
* src/nwfilter/nwfilter_ebiptables_driver.c
(ebiptablesFilterOrderSort): Likewise.
* tests/virhashtest.c (testHashGetItemsCompKey)
(testHashGetItemsCompValue): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Return statements with parameter enclosed in parentheses were modified
and parentheses were removed. The whole change was scripted, here is how:
List of files was obtained using this command:
git grep -l -e '\<return\s*([^()]*\(([^()]*)[^()]*\)*)\s*;' | \
grep -e '\.[ch]$' -e '\.py$'
Found files were modified with this command:
sed -i -e \
's_^\(.*\<return\)\s*(\(\([^()]*([^()]*)[^()]*\)*\))\s*\(;.*$\)_\1 \2\4_' \
-e 's_^\(.*\<return\)\s*(\([^()]*\))\s*\(;.*$\)_\1 \2\3_'
Then checked for nonsense.
The whole command looks like this:
git grep -l -e '\<return\s*([^()]*\(([^()]*)[^()]*\)*)\s*;' | \
grep -e '\.[ch]$' -e '\.py$' | xargs sed -i -e \
's_^\(.*\<return\)\s*(\(\([^()]*([^()]*)[^()]*\)*\))\s*\(;.*$\)_\1 \2\4_' \
-e 's_^\(.*\<return\)\s*(\([^()]*\))\s*\(;.*$\)_\1 \2\3_'
On RHEL5, I got:
util/virrandom.c:66: warning: nested extern declaration of '_gl_verify_function66' [-Wnested-externs]
The fix is to hoist the verify earlier. Also some other hodge-podge
fixes I noticed while reviewing Dan's recent series.
* .gitignore: Ignore new test.
* src/util/cgroup.c: Bump copyright year.
* src/util/virhash.c: Fix typo in description.
* src/util/virrandom.c (virRandomBits): Mark doc comment, and
hoist assert to silence older gcc.
Recent discussions have illustrated the potential for DOS attacks
with the hash table implementations used by most languages and
libraries.
https://lwn.net/Articles/474912/
libvirt has an internal hash table impl, and uses hash tables for
a variety of purposes. The hash key generation code is pretty
simple and thus not strongly collision resistant.
This patch replaces the current libvirt hash key generator with
the (public domain) Murmurhash3 code. In addition every hash
table now gets a random seed value which is used to perturb the
hashing code. This should make it impossible to mount any
practical attack against libvirt hashing code.
* bootstrap.conf: Import bitrotate module
* src/Makefile.am: Add virhashcode.[ch]
* src/util/util.c: Make virRandom() return a fixed 32 bit
integer value.
* src/util/hash.c, src/util/hash.h, src/util/cgroup.c: Replace
hash code generation with a call to virHashCodeGen()
* src/util/virhashcode.h, src/util/virhashcode.c: Add a new
virHashCodeGen() API using the Murmurhash3 algorithm.
In preparation for the patch to include Murmurhash3, which
introduces a virhashcode.h and virhashcode.c files, rename
the existing hash.h and hash.c to virhash.h and virhash.c
respectively.
