Solaris has a limitation on the number of file descriptors (255)
available in stdio, so that fopen() fails if more than
255 file descriptors (sockets) are open. This prevents mibs from
being loaded after 250 sockets are open, since parse.c uses stdio.
SEan <burke_sp@pacbell.net> investigated this problem, and had this
report on using the SFIO package to solve this problem.
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The SFIO package ( http://www.research.att.com/sw/tools/sfio/ )
is a buffered streams IO package that is much more more sophisticated
than stdio, but it does support stdio API's for backward compatibility,
and that's the aspect that is important here.
To compile with SFIO, we simply add -I/usr/local/sfio/include to the
$CPPFLAGS before compiling net-snmp. This causes SFIO's stdio.h to
preempt Solaris stdio, mapping calls like fopen() and fprintf() to
the SFIO implementations. This produces a libnetsnmp that does not
have the fopen() limitation. Any application that links to this
libnetsnmp must also be linked to libsfio.
Here are the two caveats:
1. libsfio exports the functions 'getc' and 'putc', for reasons that
are not clear. These are the only symbols it exports that conflict
with stdio. While getc and putc are traditionally macros, Solaris
makes them functions in multithreaded code (compiled with -mt,
-pthread, or -D_REENTRANT). If your native stdio code links to the
libsfio versions, a crash will result.
There are two solutions to this problem. You may remove getc and putc
from libsfio, since SFIO defines getc and putc as macros, by doing:
ar d libsfio.a getc.o
ar d libsfio.a putc.o
or link to SFIO's stdio compatibility library, libstdio, ahead of
libsfio. This library wraps all of the native stdio calls with
versions that are safe for native or sfio streams, in case you
need to share streams between SFIO and native stdio codes.
2. libsfio provides 64-bit offsets in fseek(), ftell(). This is
a good thing, since SFIO is intened to avoid needless limitations,
but it means that SFIO's stdio.h defines off_t to be a 64-bit offset.
Net-SNMP uses readdir(), which returns a struct dirent containing
a 32-bit off_t, so the code compiled for SFIO doesn't access
struct dirent's correctly.
There are two solutions to this problem, as well. The first is to
include <dirent.h> at the start of SFIO's stdio.h. Since SFIO
defines a macro substitution for off_t, this leaves struct dirent's
definition unchanged.
An alternative, which I haven't verified, is to define _FILE_OFFSET_BITS
to be 64 when compiling libnetsnmp. According to what I see in Solaris's
/usr/include/sys/feature_tests.h, you can select a 64-bit off_t at
compile time with this setting, which should make readdir()'s off_t
compatible with SFIO's ftell(), fseek().
[[ We have received reports that this approach does not in fact work ]]
Finally, thanks to Phong Vo and AT&T Labs for a fast, robust and
portable package that solves this headache very neatly.
-SEan <burke_sp@pacbell.net>
------------------------------------------------------------
Solaris 8 ships with a version of PERL compiled using sun's cc.
This causes a problem when attempting to compile net-snmp with the
new PERL functionality ie.
./configure --with-mib-modules="host disman/event-mib ucd-snmp/diskio" --enable-shared --enable-embedded-perl
because during the PERL section of the compile, it attempts to do so using the methodology used to
compile the original PERL, not what you're currently using. This can be discovered by typing
perl -V
and it says (among other things)
Compiler:
cc='cc'
and you don't have the full version of Sun's C compiler on your system, it's going to break.
If you have downloaded the PERL on www.sunfreeware.com, it is compiled with some extra flags
that cause the net-snmp compile to break. Given that the PERL provided with Solaris 8 (5.005_03)
is rather stale, upgrading may be to your advantage.
Download the current stable release of PERL
http://www.cpan.org/src/stable.tar.gz and gunzip and untar.
When doing the PERL ./Configure, accept most of the defaults, except
for the following:
Use which C compiler? [cc] gcc
(it tends to default to cc even if not installed)
Any additional gcc flags? [-fno-strict-aliasing -I/usr/local/include]
(if there are any additional flags, especially relating to 64 offsets, remove these)
What command should be used to create dynamic libraries? [cc] gcc
Any special flags to pass to gcc to create a dynamically loaded library?
[-G -L/usr/local/lib]
(There shouldn't be anything extra here (see above))
Any special flags to pass to gcc to use dynamic linking? [none]
(There shouldn't be anything extra here either (see above))
What is your domain name? [.foo.com]
(it may guess wrong)
What pager is used on your system? [/bin/less] /usr/bin/more
(It wants less even if it's not installed)
It will prompt you for make depend, then do:
make
make test
make install
perl -V
if everything looks all right, do the net-snmp ./configure (don't forget to make clean if necessary)
-- Bruce Shaw <Bruce.Shaw@gov.ab.ca>
------------------------------------------------------------
The version of sed in /usr/ucb on Solaris 2.5.1 and 2.6 can't
cope with the size of the subsitution strings used in config.status.
Putting /usr/bin ahead of /usr/ucb in the search path fixes this.
