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Yaroslav Tykhiy 48aaad5fbc Our fts(3) API, as inherited from 4.4BSD, suffers from integer
fields in FTS and FTSENT structs being too narrow.  In addition,
the narrow types creep from there into fts.c.  As a result, fts(3)
consumers, e.g., find(1) or rm(1), can't handle file trees an ordinary
user can create, which can have security implications.

To fix the historic implementation of fts(3), OpenBSD and NetBSD
have already changed <fts.h> in somewhat incompatible ways, so we
are free to do so, too.  This change is a superset of changes from
the other BSDs with a few more improvements.  It doesn't touch
fts(3) functionality; it just extends integer types used by it to
match modern reality and the C standard.

Here are its points:

o For C object sizes, use size_t unless it's 100% certain that
  the object will be really small.  (Note that fts(3) can construct
  pathnames _much_ longer than PATH_MAX for its consumers.)

o Avoid the short types because on modern platforms using them
  results in larger and slower code.  Change shorts to ints as
  follows:

	- For variables than count simple, limited things like states,
	  use plain vanilla `int' as it's the type of choice in C.

	- For a limited number of bit flags use `unsigned' because signed
	  bit-wise operations are implementation-defined, i.e., unportable,
	  in C.

o For things that should be at least 64 bits wide, use long long
  and not int64_t, as the latter is an optional type.  See
  FTSENT.fts_number aka FTS.fts_bignum.  Extending fts_number `to
  satisfy future needs' is pointless because there is fts_pointer,
  which can be used to link to arbitrary data from an FTSENT.
  However, there already are fts(3) consumers that require fts_number,
  or fts_bignum, have at least 64 bits in it, so we must allow for them.

o For the tree depth, use `long'.  This is a trade-off between making
  this field too wide and allowing for 64-bit inode numbers and/or
  chain-mounted filesystems.  On the one hand, `long' is almost
  enough for 32-bit filesystems on a 32-bit platform (our ino_t is
  uint32_t now).  On the other hand, platforms with a 64-bit (or
  wider) `long' will be ready for 64-bit inode numbers, as well as
  for several 32-bit filesystems mounted one under another.  Note
  that fts_level has to be signed because -1 is a magic value for it,
  FTS_ROOTPARENTLEVEL.

o For the `nlinks' local var in fts_build(), use `long'.  The logic
  in fts_build() requires that `nlinks' be signed, but our nlink_t
  currently is uint16_t.  Therefore let's make the signed var wide
  enough to be able to represent 2^16-1 in pure C99, and even 2^32-1
  on a 64-bit platform.  Perhaps the logic should be changed just
  to use nlink_t, but it can be done later w/o breaking fts(3) ABI
  any more because `nlinks' is just a local var.

This commit also inludes supporting stuff for the fts change:

o Preserve the old versions of fts(3) functions through libc symbol
versioning because the old versions appeared in all our former releases.

o Bump __FreeBSD_version just in case.  There is a small chance that
some ill-written 3-rd party apps may fail to build or work correctly
if compiled after this change.

o Update the fts(3) manpage accordingly.  In particular, remove
references to fts_bignum, which was a FreeBSD-specific hack to work
around the too narrow types of FTSENT members.  Now fts_number is
at least 64 bits wide (long long) and fts_bignum is an undocumented
alias for fts_number kept around for compatibility reasons.  According
to Google Code Search, the only big consumers of fts_bignum are in
our own source tree, so they can be fixed easily to use fts_number.

o Mention the change in src/UPDATING.

PR:		bin/104458
Approved by:	re (quite a while ago)
Discussed with:	deischen (the symbol versioning part)
Reviewed by:	-arch (mostly silence); das (generally OK, but we didn't
		agree on some types used; assuming that no objections on
		-arch let me to stick to my opinion)
2008-01-26 17:09:40 +00:00
bin - Roll-back attempts to mimic rename(2) atomicity introduced in 1.47, 2007-12-27 11:33:42 +00:00
cddl Remove _SOLARIS_C_SOURCE now that it doesn't do anything in FreeBSD 2007-11-28 22:58:09 +00:00
compat/opensolaris Add more OpenSolaris compatibilty headers. 2007-11-28 21:40:07 +00:00
contrib Add a -P flag to display per-cpu cpu usage stats. 2008-01-18 01:43:14 +00:00
crypto Unbreak detection of cryptodev support for FreeBSD which was broken 2008-01-13 11:44:47 +00:00
etc Generally, anything that runs rc.d scripts internally should 2008-01-26 14:02:19 +00:00
games A real gem from freebsd-current@ 2008-01-10 14:51:24 +00:00
gnu Move the code for working with kld's out into its own file. 2008-01-24 19:11:13 +00:00
include Our fts(3) API, as inherited from 4.4BSD, suffers from integer 2008-01-26 17:09:40 +00:00
kerberos5 While checking over the libraries for 7.0-REL Kris found the following 2007-11-20 04:20:32 +00:00
lib Our fts(3) API, as inherited from 4.4BSD, suffers from integer 2008-01-26 17:09:40 +00:00
libexec For un-prototyped static inline functions declared in pthread_md.h on 2007-12-01 14:24:44 +00:00
release In 'fixit mode' running "fsck /dev/ad0s1a" typically complains that it 2008-01-22 16:35:10 +00:00
rescue o Build geom for all platforms. 2007-11-04 00:44:10 +00:00
sbin Sync up quotacheck's preen.c with fsck's. This makes quotacheck 2008-01-26 12:03:26 +00:00
secure - Bump share library version which were missed in last bump 2007-06-18 18:47:54 +00:00
share Explain how the passno field in /etc/fstab works with fsck 2008-01-26 13:03:35 +00:00
sys Our fts(3) API, as inherited from 4.4BSD, suffers from integer 2008-01-26 17:09:40 +00:00
tools Update the timestamp regexps in syncstamp() and monostamp() for > 99999 2008-01-25 19:24:12 +00:00
usr.bin Document the no-op -r option of BSD xargs(1). 2008-01-26 12:38:19 +00:00
usr.sbin Clarify in what formats the grouplist for the '-G' switch may be accepted. 2008-01-25 15:54:14 +00:00
COPYRIGHT Happy new year 2008! 2007-12-31 22:09:19 +00:00
LOCKS Once the release goes out, RELENG_7_* will need approval from so@. 2008-01-24 22:07:03 +00:00
MAINTAINERS Update the maintainer id for em driver. 2007-05-23 21:47:19 +00:00
Makefile We don't need to invent BSDMAKE. ${MAKE} is sufficient. 2007-12-13 00:08:02 +00:00
Makefile.inc1 Support source upgrades from at least 6.0-RELEASE. 2008-01-23 22:21:36 +00:00
ObsoleteFiles.inc Reflect BUF_REFCNT(9) removal. 2008-01-22 20:08:09 +00:00
README Simply running ``make world'' will bomb unless you dig up the 2006-06-07 03:33:48 +00:00
UPDATING Our fts(3) API, as inherited from 4.4BSD, suffers from integer 2008-01-26 17:09:40 +00:00

This is the top level of the FreeBSD source directory.  This file
was last revised on:
$FreeBSD$

For copyright information, please see the file COPYRIGHT in this
directory (additional copyright information also exists for some
sources in this tree - please see the specific source directories for
more information).

The Makefile in this directory supports a number of targets for
building components (or all) of the FreeBSD source tree, the most
commonly used one being ``world'', which rebuilds and installs
everything in the FreeBSD system from the source tree except the
kernel, the kernel-modules and the contents of /etc.  The ``world''
target should only be used in cases where the source tree has not
changed from the currently running version.  See:
http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/makeworld.html
for more information, including setting make(1) variables.

The ``buildkernel'' and ``installkernel'' targets build and install
the kernel and the modules (see below).  Please see the top of
the Makefile in this directory for more information on the
standard build targets and compile-time flags.

Building a kernel is a somewhat more involved process, documentation
for which can be found at:
   http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig.html
And in the config(8) man page.
Note: If you want to build and install the kernel with the
``buildkernel'' and ``installkernel'' targets, you might need to build
world before.  More information is available in the handbook.

The sample kernel configuration files reside in the sys/<arch>/conf
sub-directory (assuming that you've installed the kernel sources), the
file named GENERIC being the one used to build your initial installation
kernel.  The file NOTES contains entries and documentation for all possible
devices, not just those commonly used.  It is the successor of the ancient
LINT file, but in contrast to LINT, it is not buildable as a kernel but a
pure reference and documentation file.


Source Roadmap:
---------------
bin		System/user commands.

contrib		Packages contributed by 3rd parties.

crypto		Cryptography stuff (see crypto/README).

etc		Template files for /etc.

games		Amusements.

gnu		Various commands and libraries under the GNU Public License.
		Please see gnu/COPYING* for more information.

include		System include files.

kerberos5	Kerberos5 (Heimdal) package.

lib		System libraries.

libexec		System daemons.

release		Release building Makefile & associated tools.

rescue		Build system for statically linked /rescue utilities.

sbin		System commands.

secure		Cryptographic libraries and commands.

share		Shared resources.

sys		Kernel sources.

tools		Utilities for regression testing and miscellaneous tasks.

usr.bin		User commands.

usr.sbin	System administration commands.


For information on synchronizing your source tree with one or more of
the FreeBSD Project's development branches, please see:

  http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/synching.html