This used to be a minor optimization on ix86 where registers are scarce
and the calling convention not very efficient, but this platform is not
relevant enough anymore to warrant all this dirt in the code for the sake
of saving 1 or 2% of performance. Modern platforms don't use this at all
since their calling convention already defaults to using several registers
so better get rid of this once for all.
(from ebtree 6.0.7)
Julien Thomas provided a reproducible test case where a string lookup
could return the wrong node. The issue is caused by the jump to a node
which contains less bit in common than the previous node, making the
string_equal_bits() function return -1. We must not remember more bits
than the number on the node, otherwise we can be tempted to trust them
while they can change while running down.
For a valid test case, enter : "0", "WW", "W", "S", and lookup "W".
Previously, "S" was returned.
Note: string-based ebtrees are used in haproxy in ACL, peers and
stick-tables. ACLs are not affected because all patterns are
interchangeable. stick-tables are not affected because lookups are
performed using ebmb_lookup(). Only peers might be affected though
it is not easy to infirm or confirm the issue.
(cherry picked from commit dd47a54103597458887d3cc8414853a541aee9c1)
(from ebtree 6.0.7)
root_right was wrongly initialized first to <root> which is not the same
type, to be later initialized to root->b[EB_RGHT].
Let's simply remove the wrong and useless initialization.
(cherry picked from commit e63a0c2f56369b52c4d00221d83c2c4569605c06)
(from ebtree 6.0.6)
This version is mainly aimed at clarifying the fact that the ebtree license
is LGPL. Some files used to indicate LGPL and other ones GPL, while the goal
clearly is to have it LGPL. A LICENSE file has also been added.
No code is affected, but it's better to have the local tree in sync anyway.
(cherry picked from commit 24dc7cca051f081600fe8232f33e55ed30e88425)
(from ebtree 6.0.5)
Both of them are very short and rely on another non-inlined lookup function,
so it's pointless to have them as pure functions, it wastes space.
(cherry picked from commit 1e68d6fef815f759304d4cc0e65f957689e19a7a)
(update to ebtree 6.0.4)
Recent fix fd301cc1370cd4977fe175dfa4544c7dc0e7ce6b was not OK because it
was returning one excess byte, causing some duplicates not to be detected.
The reason is that we added 8 bits to count the trailing zero but they
were implied by the pre-incrementation of the pointer.
Fixing this was still not enough, as the problem appeared when
string_equal_bits() was applied on two identical strings, and it returned
a number of bits covering the trailing zero. Subsequent calls were applied
to the first byte after this trailing zero. It was often zero when doing
insertion from raw files, explaining why the issue was not discovered
earlier. But when the data is from a reused area, duplicate strings are not
correctly detected when inserting into the tree.
Several solutions were tested, and the only efficient one consists in making
string_equal_bits() notify the caller that the end of the string was reached.
It now returns zero and the callers just have to ensure that when they get a
zero, they stop using that bit until a dup tree or a leaf is encountered.
This fix brought the unexpected bonus of simplifying the insertion code a bit
and making it slightly faster to process duplicates.
The impact for haproxy was that if many similar string patterns were loaded
from a file, there was a potential risk that their insertion or matching could
have been slower. The bigger impact was with the URL sorting feature of halog,
which is not yet merged and is how this bug was discovered.
(cherry picked from commit 518d59ec9ba43705f930f9ece3749c450fd005df)
This version adds support for prefix-based matching of memory blocks,
as well as some code-size and performance improvements on the generic
code. It provides a prefix insertion and longest match which are
compatible with the rest of the common features (walk, duplicates,
delete, ...). This is typically used for network address matching. The
longest-match code is a bit slower than the original memory block
handling code, so they have not been merged together into generic
code. Still it's possible to perform about 10 million networks lookups
per second in a set of 50000, so this should be enough for most usages.
This version also fixes some bugs in parts that were not used, so there
is no need to backport them.
Sometimes it's useful to lookup a string without terminating it with a
zero. We can do that relying on ebmb_lookup() since the string in the
tree contains a zero.
We needed to upgrade ebtree to v5.0 to support string indexing,
and it was getting very painful to have it split across 2 dirs
and to have to patch it. Now we just have to copy the .c and .h
files to the right place.
