5:56 a.m.
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[I thought I'd send this to the ITS list=2C but I only sent it to myself :-=
( ]
> There is another bug in
send_list() in sssvlv.c=2C at lines 535-544:
> if ( i > 0 ) {
> tmp_node =3D tavl_end(so->so_tree=2C TAVL_DIR_RIGHT)=3B
> dir =3D TAVL_DIR_LEFT=3B
> } else {
> tmp_node =3D tavl_end(so->so_tree=2C TAVL_DIR_LEFT)=3B
> dir =3D TAVL_DIR_RIGHT=3B
> }
> for (i=3D0=3B tmp_node !=3D cur_node=3B
> tmp_node =3D tavl_next( tmp_node=2C dir )=2C i++)=3B
> so->so_vlv_target =3D i=3B
> This code is ok if the cur_node is in the left hand side of the tree=2C= but
if it is in the rhs of the tree so_vlv_target is set
I've uploaded a patch to ftp.openldap.org=2C incoming/Chris-Card-110708.ITS=
-6985-fix.patch
Chris
=
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dir=3D'ltr' [I thought I'd send this to the
ITS list=2C but I only sent it to myself :-=
( ]<br><br><div><br>>=3B >=3B >=3B >=3B
>=3B<br>>=3B >=3B >=
=3B >=3B >=3B I am running slapd built from HEAD on June 30th 2011=2C w=
ith back-sql<br>>=3B >=3B >=3B >=3B<br>>=3B
>=3B >=3B >=3B =
Can you confirm this issue with another backend=2C e.g. back-bdb? Bugs<br>&=
gt=3B >=3B >=3B >=3B specific to back-sql or to interaction with it c=
ould receive only marginal<br>>=3B >=3B >=3B >=3B
attention.<br>>=
=3B >=3B >=3B >=3B<br>>=3B >=3B >=3B >=3B
p.<br>>=3B >=3B=
>=3B >=3B<br>>=3B >=3B >=3B<br>>=3B
>=3B >=3B I've importe=
d my data into a server with a bdb backend=2C and I see the same problem.<b=
r>>=3B >=3B >=3B<br>>=3B >=3B >=3B Looking at
the code in sssvl=
v.c=2C it uses tavl_find3() to search the values=2C but the<br>>=3B >=
=3B >=3B code in tavl_find3() looks to me that it only works properly wit=
h an exact match<br>>=3B >=3B >=3B type of matching
rule:<br>>=3B &=
gt=3B >=3B<br>>=3B >=3B >=3B Avlnode *<br>>=3B
>=3B >=3B tavl=
_find3( Avlnode *root=2C const void *data=2C AVL_CMP fcmp=2C int *ret )<br>=
>=3B >=3B >=3B {<br>>=3B >=3B >=3B int cmp =3D
-1=2C dir=3B<br>=
>=3B >=3B >=3B Avlnode *prev =3D root=3B<br>>=3B >=3B
>=3B<br>&=
gt=3B >=3B >=3B while ( root !=3D 0 &=3B&=3B (cmp =3D (*fcmp)(
da=
ta=2C root->=3Bavl_data )) !=3D 0 ) {<br>>=3B >=3B >=3B prev
=3D ro=
ot=3B<br>>=3B >=3B >=3B dir =3D cmp >=3B
0=3B<br>>=3B >=3B >=
=3B root =3D avl_child( root=2C dir )=3B<br>>=3B >=3B >=3B
}<br>>=
=3B >=3B >=3B *ret =3D cmp=3B<br>>=3B >=3B >=3B return
root ? roo=
t : prev=3B<br>>=3B >=3B >=3B }<br>>=3B >=3B
>=3B<br>>=3B >=
=3B >=3B since the while loop terminates when the fcmp function returns 0=
(i.e. exact match).<br>>=3B >=3B >=3B<br>>=3B
>=3B<br>>=3B >=
=3B I think I've worked out where the problem is.<br>>=3B >=3B
Firstly=
=2C there's a comment before tavl_find3() saying<br>>=3B >=3B
/*<br>>=
=3B >=3B * tavl_find2 - returns Avlnode instead of data pointer.<br>>=
=3B >=3B * tavl_find3 - as above=2C but returns Avlnode even if no match =
is found.<br>>=3B >=3B * also set *ret =3D last comparison result=2C
or=
-1 if root =3D=3D NULL.<br>>=3B >=3B */<br>>=3B
>=3B<br>>=3B >=
=3B but the "or -1 if root =3D=3D NULL" is not done.<br>>=3B
>=3B<br>&g=
t=3B >=3B Secondly=2C if no exact match is found=2C prev is returned whic=
h may point to a node which is less than the search<br>>=3B >=3B node=
=2C depending on what the tree looks like=2C but we really want a pointer t=
o the last node which was greater than<br>>=3B >=3B the search node to
=
be returned.<br>>=3B >=3B<br>>=3B >=3B Once these
fixes are done=2C=
the correct node is returned by tavl_find3 to the call in send_list() in s=
ssvlv.c (line 523).<br>>=3B >=3B<br>>=3B >=3B There is
another bug =
in send_list() in sssvlv.c=2C at lines 535-544:<br>>=3B
>=3B<br>>=3B =
>=3B if ( i >=3B 0 ) {<br>>=3B >=3B tmp_node =3D
tavl_end(so->=3B=
so_tree=2C TAVL_DIR_RIGHT)=3B<br>>=3B >=3B dir =3D
TAVL_DIR_LEFT=3B<br>=
>=3B >=3B } else {<br>>=3B >=3B tmp_node =3D
tavl_end(so->=3Bso_t=
ree=2C TAVL_DIR_LEFT)=3B<br>>=3B >=3B dir =3D
TAVL_DIR_RIGHT=3B<br>>=
=3B >=3B }<br>>=3B >=3B for (i=3D0=3B tmp_node !=3D
cur_node=3B<br>&g=
t=3B >=3B tmp_node =3D tavl_next( tmp_node=2C dir )=2C i++)=3B<br>>=3B
=
>=3B so->=3Bso_vlv_target =3D i=3B<br>>=3B >=3B This code is
ok if =
the cur_node is in the left hand side of the tree=2C but if it is in the rh=
s of the tree so_vlv_target is set<br>>=3B >=3B to an offset from the
e=
nd of the list=2C rather than the beginning.<br>>=3B
>=3B<br>>=3B<br>=
>=3B One more issue: the most recent draft spec for vlv (http://tools.iet=
f.org/html/draft-ietf-ldapext-ldapv3-vlv-09) states that the offset field i=
n the vlv request has range 1..maxInt whereas the targetPosition in the vlv=
response has range 0..maxInt.<br>>=3B<br>>=3B However=2C my
interpreta=
tion of the spec is that offset and targetPosition represent the same thing=
=2C i.e. the position of the target entry in the list=2C with the first ent=
ry having offset/targetPosition =3D 1.<br>>=3B<br>>=3B If that
interpre=
tation is correct=2C the assignment of so_vlv_target in the code above is o=
ff by one=2C since i will be zero if cur_node is at the beginning of the li=
st.<br>>=3B<br><br>I've uploaded a patch to
ftp.openldap.org=2C incoming/=
Chris-Card-110708.ITS-6985-fix.patch<br><br></div><div>Chris<br><br></div>
=
</div></body </html>=
--_3d71bf45-bf8f-4026-9c30-d39291bf9f56_--
> > > >
> > > I am running slapd built from HEAD on June 30th 2011=2C with back=
-sql
> > > > > Can you confirm this
issue with another backend=2C e.g. back-bdb? B=
ugs
> > > specific to back-sql or to interaction with it could
receive only m=
arginal
> > > attention.
> > > > > p.
> > > >
> I've imported my data into a server with a bdb backend=2C and I see t=
he
same problem.
> > > Looking at the code in
sssvlv.c=2C it uses tavl_find3() to search the=
values=2C but the
> > code in tavl_find3() looks to me that it only works
properly with an =
exact match
> > type of matching rule:
> > > Avlnode *
> > tavl_find3( Avlnode *root=2C const void *data=2C AVL_CMP fcmp=2C int =
*ret )
> > {
> > int cmp =3D -1=2C dir=3B
> > Avlnode *prev =3D root=3B
> > > while ( root !=3D 0 && (cmp =3D (*fcmp)(
data=2C root->avl_data )) !=
=3D 0 ) {
> > prev =3D root=3B
> > dir =3D cmp > 0=3B
> > root =3D avl_child( root=2C dir )=3B
> > }
> > *ret =3D cmp=3B
> > return root ? root : prev=3B
> > }
> > > since the while loop terminates when the fcmp
function returns 0 (i.e=
. exact match).
> > I
think I've worked out where the problem is.
> Firstly=2C there's a comment before tavl_find3() saying
> /*
> * tavl_find2 - returns Avlnode instead of data pointer.
> * tavl_find3 - as above=2C but returns Avlnode even if no match is foun=
d.
> * also set *ret =3D last comparison result=2C or -1 if root
=3D=3D NULL=
.
> */
> but the "or -1 if root =3D=3D NULL" is not
done.
> Secondly=2C if no exact match is found=2C prev is
returned which may po=
int to a node which is less than the search
> node=2C depending on what the tree looks like=2C but we really
want a p=
ointer to the last node which was greater than
> the search node to be returned.
> Once these fixes are done=2C the correct node is returned
by tavl_find3=
to the call in send_list() in sssvlv.c (line 523).
> to an offset from the end of the list=2C rather than the
beginning.
One more issue: the most recent draft spec for vlv (http://tools.ietf.org=
/html/draft-ietf-ldapext-ldapv3-vlv-09) states that the offset field in the=
vlv request has range 1..maxInt whereas the targetPosition in the vlv resp=
onse has range 0..maxInt.
However=2C my interpretation of the spec is that offset and targetPositio=
n
represent the same thing=2C i.e. the position of the target entry in the =
list=2C with the first entry having offset/targetPosition =3D 1.
If that interpretation is correct=2C the assignment of so_vlv_target in t=
he code
above is off by one=2C since i will be zero if cur_node is at the b=
eginning of the list.
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