- Every non-const pointer converts automatically to void *.
- Every pointer converts automatically to void *.
- void * converts to any other pointer.
- const void * converts to any other const pointer.
- Integer variables convert to each other.
I changed the declaration of a few variables in order to allow removing
a cast.
However, I didn't attempt to edit casts inside comparisons, since they
are very delicate. I also kept casts in variadic functions, since they
are necessary, and in allocation functions, because I have other plans
for them.
I also changed a few casts to int that are better as ptrdiff_t.
This change has triggered some warnings about const correctness issues,
which have also been fixed in this patch (see for example src/login.c).
Signed-off-by: Alejandro Colomar <alx@kernel.org>
In variadic functions we still do the cast. In POSIX, it's not
necessary, since NULL is required to be of type 'void *', and 'void *'
is guaranteed to have the same alignment and representation as 'char *'.
However, since ISO C still doesn't mandate that, and moreover they're
doing dubious stuff by adding nullptr, let's be on the cautious side.
Also, C++ requires that NULL is _not_ 'void *', but either plain 0 or
some magic stuff.
Signed-off-by: Alejandro Colomar <alx@kernel.org>
If lines start with '\0' then it is possible to trigger out of
boundary accesses.
Check if indices are valid before accessing them.
Signed-off-by: Samanta Navarro <ferivoz@riseup.net>
gethostbyname(3) was removed in POSIX.1-2008. It has been obsoleted,
and replaced by getaddrinfo(3), which is superior in several ways:
- gethostbyname(3) is not reentrant. There's a GNU extension,
gethostbyname_r(3) which is reentrant, but it's not likely to be
standardized for the following reason. And we don't care too much
about this point either.
- gethostbyname(3) only supports IPv4, but getaddrinfo(3) supports both
IPv4 and IPv6 (and may support other address families in the future).
We don't care about reentrancy, so for keeping the code simple (i.e.,
not touch call site to add code to free(3) an allocated buffer), I added
a static buffer for inet_ntop(3). We could address that in the future,
but I don't think it's worth it.
BTW, we also replace inet_ntoa(3) by inet_ntop(3), as a consequence of
using getaddrinfo(3). inet_ntoa(3) is also marked as deprecated, but
that deprecation seems to have been documented only in the manual page,
and POSIX doesn't mark it as deprecated. The deprecation notice goes
back to when the inet_ntop(3) manual page was added by Sam Varshavchik
to the Linux man-pages in version 1.30 (year 2000).
So, this, apart from updating the code to POSIX.1-2008, is also adding
support for IPv6 :) Although, probably many other parts of the code are
written for IPv4 only, so I wouldn't yet claim support for it.
A few notes:
- I didn't check the return value of inet_ntop(3), since it can't fail
for the given input:
- EAFNOSUPPORT: We only call it with AF_INET and AF_INET6.
- ENOSPC: We calculate the size of the buffer to be wide enough:
MAX(INET_ADDRSTRLEN, INET6_ADDRSTRLEN) so it always fits.
Cc: Dave Hagewood <admin@arrowweb.com>
Cc: Sam Varshavchik
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Iker Pedrosa <ipedrosa@redhat.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
It is Undefined Behavior to declare errno (see NOTES in its manual page).
Instead of using the errno dummy declaration, use one that doesn't need
a comment.
Signed-off-by: Alejandro Colomar <alx@kernel.org>
* src/login_nopam.c: Limit the scope of variables end, lineno, i,
str_len.
* src/logoutd.c: Limit the scope of variable c.
* src/vipw.c: Re-indent.
* src/vipw.c: Close the file after the creation of the backup.
* src/useradd.c (set_default): Close input file on failure.
* src/useradd.c: Limit the scope of variables spool, file, fd, gr,
gid, mode.
* src/passwd.c: Limit the scope of variables last and ok.
* src/chage.c: Fix typo (non breaking space).
* src/login.c: Limit the scope of variables erasechar killchar, c,
failed.
* src/groups.c: Limit the scope of variable ngroups, pri_grp, i.
* src/id.c: Limit the scope of variable i.
libmisc/loginprompt.c, libmisc/ttytype.c, libmisc/tz.c,
src/login_nopam.c, src/chpasswd.c, src/chgpasswd.c, lib/port.c:
The size argument of fgets is an int, not a size_t.
* libmisc/loginprompt.c: Ignore the return value from signal()
when the signal handlers are restored.
* src/chpasswd.c: Cast the return value of time() to a long
integer.
* src/chpasswd.c: Use the SCALE macro instead of (24L * 3600L)
for the values to be set in /etc/shadow.
booleans true and false instead. Change the prototypes of
list_match(), user_match(), from_match(), and string_match()
accordingly. Also use booleans internally.
* src/login_nopam.c: Add brackets and parenthesis.
* src/login_nopam.c: Avoid implicit conversion of pointers /
integers / chars to booleans.
* src/login_nopam.c: Avoid assignments in comparisons.
instead of K&R prototype.
* src/login_nopam.c: Fix the prototypes of list_match(),
user_match(), from_match(), string_match(). There were no
parameters in the prototypes.
* src/login_nopam.c: Fix the prototypes of the function parameter
match_fn of list_match().
libmisc/xgetXXbyYY.c, libmisc/xgetpwnam.c, libmisc/xgetpwuid.c,
libmisc/xgetgrnam.c, libmisc/xgetgrgid.c, libmisc/xgetspnam.c:
Added functions xgetpwnam(), xgetpwuid(), xgetgrnam(),
xgetgrgid(), and xgetspnam(). They allocate memory for the
returned structure and are more robust to successive calls. They
are implemented with the libc's getxxyyy_r() functions if
available.
* libmisc/limits.c, libmisc/entry.c, libmisc/chowntty.c,
libmisc/addgrps.c, libmisc/myname.c, libmisc/rlogin.c,
libmisc/pwdcheck.c, src/newgrp.c, src/login_nopam.c,
src/userdel.c, src/lastlog.c, src/grpck.c, src/gpasswd.c,
src/newusers.c, src/chpasswd.c, src/chfn.c, src/groupmems.c,
src/usermod.c, src/expiry.c, src/groupdel.c, src/chgpasswd.c,
src/su.c, src/useradd.c, src/groupmod.c, src/passwd.c, src/pwck.c,
src/groupadd.c, src/chage.c, src/login.c, src/suauth.c,
src/faillog.c, src/groups.c, src/chsh.c, src/id.c: Review all the
usage of one of the getpwnam(), getpwuid(), getgrnam(),
getgrgid(), and getspnam() functions. It was noticed on
http://bugs.debian.org/341230 that chfn and chsh use a passwd
structure after calling a pam function, which result in using
information from the passwd structure requested by pam, not the
original one. It is much easier to use the new xget... functions
to avoid these issues. I've checked which call to the original
get... functions could be left (reducing the scope of the
structure if possible), and I've left comments to ease future
reviews (e.g. /* local, no need for xgetpwnam */).
Note: the getpwent/getgrent calls should probably be checked also.
* src/groupdel.c, src/expiry.c: Fix typos in comments.
* src/groupmod.c: Re-indent.
* libmisc/Makefile.am, lib/groupmem.c, lib/groupio.c, lib/pwmem.c,
lib/pwio.c, lib/shadowmem.c, lib/shadowio.c: Move the __<xx>_dup
functions (used by the xget... functions) from the <xx>io.c files
to the new <xx>mem.c files. This avoid linking some utils against
the SELinux library.
Alejandro Colomar
Samanta Navarro
Serge Hallyn
Luís Ferreira
nekral-guest