Reviewed by:	bcr (mentor)
Approved by:	bcr (mentor)
Differential Revision:	https://reviews.freebsd.org/D24795

Typo.

data from /etc/passwd rather than /etc/master.passwd.

The libc getpwent(3) and related functions automatically read master.passwd
when run by root, or passwd when run by a non-root user.  When run by non-
root, getpwent() copes with the missing data by setting the corresponding
fields in the passwd struct to known values (zeroes for numbers, or a
pointer to an empty string for literals).  When libutil's pw_scan(3) was
used to parse a line without the root-accessible data, it was leaving
garbage in the corresponding fields.

These changes rename the static pw_init() function used by getpwent() and
friends to __pw_initpwd(), and move it into pw_scan.c so that common init
code can be shared between libc and libutil.  pw_scan(3) now calls
__pw_initpwd() before __pw_scan(), just like the getpwent() family does, so
that reading an arbitrary passwd file in either format and parsing it with
pw_scan(3) returns the same results as getpwent(3) would.

This also adds a new pw_initpwd(3) function to libutil, so that code which
creates passwd structs from scratch in some manner that doesn't involve
pw_scan() can initialize the struct to the values expected by lots of
existing code, which doesn't expect to encounter NULL pointers or garbage
values in some fields.

Spotted by:	loos
Approved by:	loos

Suggested by:	wblock
Approved by:	gnn

temporary file is created and then a rename() call move it to official file.
This operation didn't have any check to make sure data was written to disk
and if a power cycle happens system could end up with a 0 length passwd
or group database.

There is a pfSense bug with more infor about it:

https://redmine.pfsense.org/issues/4523

The following changes were made to protect passwd and group operations:

* lib/libutil/gr_util.c:
 - Replace mkstemp() by mkostemp() with O_SYNC flag to create temp file
 - After rename(), fsync() call on directory for faster result

* lib/libutil/pw_util.c
 - Replace mkstemp() by mkostemp() with O_SYNC flag to create temp file

* usr.sbin/pwd_mkdb/pwd_mkdb.c
 - Added O_SYNC flag on dbopen() calls
 - After rename(), fsync() call on directory for faster result

* lib/libutil/pw_util.3
 - pw_lock() returns a file descriptor to master password file on success

Differential Revision:	https://reviews.freebsd.org/D2978
Approved by:	bapt
Sponsored by:	Netgate

Suggested by:	wblock

it takes a new argument allowing to specify the endianness of the database
to generate

Differential Revision:	https://reviews.freebsd.org/D2730
Reviewed by:	ian