busybox/loginutils/deluser.c
James Byrne 6937487be7 libbb: reduce the overhead of single parameter bb_error_msg() calls
Back in 2007, commit 0c97c9d437 ("'simple' error message functions by
Loic Grenie") introduced bb_simple_perror_msg() to allow for a lower
overhead call to bb_perror_msg() when only a string was being printed
with no parameters. This saves space for some CPU architectures because
it avoids the overhead of a call to a variadic function. However there
has never been a simple version of bb_error_msg(), and since 2007 many
new calls to bb_perror_msg() have been added that only take a single
parameter and so could have been using bb_simple_perror_message().

This changeset introduces 'simple' versions of bb_info_msg(),
bb_error_msg(), bb_error_msg_and_die(), bb_herror_msg() and
bb_herror_msg_and_die(), and replaces all calls that only take a
single parameter, or use something like ("%s", arg), with calls to the
corresponding 'simple' version.

Since it is likely that single parameter calls to the variadic functions
may be accidentally reintroduced in the future a new debugging config
option WARN_SIMPLE_MSG has been introduced. This uses some macro magic
which will cause any such calls to generate a warning, but this is
turned off by default to avoid use of the unpleasant macros in normal
circumstances.

This is a large changeset due to the number of calls that have been
replaced. The only files that contain changes other than simple
substitution of function calls are libbb.h, libbb/herror_msg.c,
libbb/verror_msg.c and libbb/xfuncs_printf.c. In miscutils/devfsd.c,
networking/udhcp/common.h and util-linux/mdev.c additonal macros have
been added for logging so that single parameter and multiple parameter
logging variants exist.

The amount of space saved varies considerably by architecture, and was
found to be as follows (for 'defconfig' using GCC 7.4):

Arm:     -92 bytes
MIPS:    -52 bytes
PPC:   -1836 bytes
x86_64: -938 bytes

Note that for the MIPS architecture only an exception had to be made
disabling the 'simple' calls for 'udhcp' (in networking/udhcp/common.h)
because it made these files larger on MIPS.

Signed-off-by: James Byrne <james.byrne@origamienergy.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-07-02 11:35:03 +02:00

163 lines
4.6 KiB
C

/* vi: set sw=4 ts=4: */
/*
* deluser/delgroup implementation for busybox
*
* Copyright (C) 1999 by Lineo, inc. and John Beppu
* Copyright (C) 1999,2000,2001 by John Beppu <beppu@codepoet.org>
* Copyright (C) 2007 by Tito Ragusa <farmatito@tiscali.it>
*
* Licensed under GPLv2, see file LICENSE in this source tree.
*/
//config:config DELUSER
//config: bool "deluser (9.1 kb)"
//config: default y
//config: help
//config: Utility for deleting a user account.
//config:
//config:config DELGROUP
//config: bool "delgroup (6.4 kb)"
//config: default y
//config: help
//config: Utility for deleting a group account.
//config:
//config:config FEATURE_DEL_USER_FROM_GROUP
//config: bool "Support removing users from groups"
//config: default y
//config: depends on DELGROUP
//config: help
//config: If called with two non-option arguments, deluser
//config: or delgroup will remove an user from a specified group.
// APPLET_NOEXEC:name main location suid_type help
//applet:IF_DELUSER( APPLET_NOEXEC(deluser, deluser, BB_DIR_USR_SBIN, BB_SUID_DROP, deluser))
//applet:IF_DELGROUP(APPLET_NOEXEC(delgroup, deluser, BB_DIR_USR_SBIN, BB_SUID_DROP, delgroup))
//kbuild:lib-$(CONFIG_DELUSER) += deluser.o
//kbuild:lib-$(CONFIG_DELGROUP) += deluser.o
//usage:#define deluser_trivial_usage
//usage: IF_LONG_OPTS("[--remove-home] ") "USER"
//usage:#define deluser_full_usage "\n\n"
//usage: "Delete USER from the system"
// --remove-home is self-explanatory enough to put it in --help
//usage:#define delgroup_trivial_usage
//usage: IF_FEATURE_DEL_USER_FROM_GROUP("[USER] ")"GROUP"
//usage:#define delgroup_full_usage "\n\n"
//usage: "Delete group GROUP from the system"
//usage: IF_FEATURE_DEL_USER_FROM_GROUP(" or user USER from group GROUP")
#include "libbb.h"
int deluser_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int deluser_main(int argc, char **argv)
{
/* User or group name */
char *name;
/* Username (non-NULL only in "delgroup USER GROUP" case) */
char *member;
/* Name of passwd or group file */
const char *pfile;
/* Name of shadow or gshadow file */
const char *sfile;
/* Are we deluser or delgroup? */
int do_deluser = (ENABLE_DELUSER && (!ENABLE_DELGROUP || applet_name[3] == 'u'));
#if !ENABLE_LONG_OPTS
const int opt_delhome = 0;
#else
int opt_delhome = 0;
if (do_deluser) {
opt_delhome = getopt32long(argv, "",
"remove-home\0" No_argument "\xff");
argv += opt_delhome;
argc -= opt_delhome;
}
#endif
if (geteuid() != 0)
bb_simple_error_msg_and_die(bb_msg_perm_denied_are_you_root);
name = argv[1];
member = NULL;
switch (argc) {
case 3:
if (!ENABLE_FEATURE_DEL_USER_FROM_GROUP || do_deluser)
break;
/* It's "delgroup USER GROUP" */
member = name;
name = argv[2];
/* Fallthrough */
case 2:
if (do_deluser) {
/* "deluser USER" */
struct passwd *pw;
pw = xgetpwnam(name); /* bail out if USER is wrong */
pfile = bb_path_passwd_file;
if (ENABLE_FEATURE_SHADOWPASSWDS)
sfile = bb_path_shadow_file;
if (opt_delhome)
remove_file(pw->pw_dir, FILEUTILS_RECUR);
} else {
struct group *gr;
do_delgroup:
/* "delgroup GROUP" or "delgroup USER GROUP" */
if (do_deluser < 0) { /* delgroup after deluser? */
gr = getgrnam(name);
if (!gr)
return EXIT_SUCCESS;
} else {
gr = xgetgrnam(name); /* bail out if GROUP is wrong */
}
if (!member) {
/* "delgroup GROUP" */
struct passwd *pw;
/* Check if the group is in use */
while ((pw = getpwent()) != NULL) {
if (pw->pw_gid == gr->gr_gid)
bb_error_msg_and_die("'%s' still has '%s' as their primary group!",
pw->pw_name, name);
}
//endpwent();
}
pfile = bb_path_group_file;
if (ENABLE_FEATURE_SHADOWPASSWDS)
sfile = bb_path_gshadow_file;
}
/* Modify pfile, then sfile */
do {
if (update_passwd(pfile, name, NULL, member) == -1)
return EXIT_FAILURE;
if (ENABLE_FEATURE_SHADOWPASSWDS) {
pfile = sfile;
sfile = NULL;
}
} while (ENABLE_FEATURE_SHADOWPASSWDS && pfile);
if (do_deluser > 0) {
/* Delete user from all groups */
if (update_passwd(bb_path_group_file, NULL, NULL, name) == -1)
return EXIT_FAILURE;
if (ENABLE_DELGROUP) {
/* "deluser USER" also should try to delete
* same-named group. IOW: do "delgroup USER"
*/
// On debian deluser is a perl script that calls userdel.
// From man userdel:
// If USERGROUPS_ENAB is defined to yes in /etc/login.defs, userdel will
// delete the group with the same name as the user.
do_deluser = -1;
goto do_delgroup;
}
}
return EXIT_SUCCESS;
}
/* Reached only if number of command line args is wrong */
bb_show_usage();
}