busybox/coreutils/id.c
Denis Vlasenko 2228426512 id: fix "id <user>" case. Requires getgrouplist().
function                                             old     new   delta
getgrouplist_internal                                  -     200    +200
id_main                                              462     539     +77
bb_internal_getgrouplist                               -      67     +67
bb__parsespent                                       119     117      -2
bb_internal_initgroups                               213      58    -155
------------------------------------------------------------------------------
(add/remove: 2/0 grow/shrink: 1/2 up/down: 344/-157)          Total: 187 bytes
2008-09-18 00:56:24 +00:00

179 lines
4.2 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Mini id implementation for busybox
*
* Copyright (C) 2000 by Randolph Chung <tausq@debian.org>
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
/* BB_AUDIT SUSv3 compliant. */
/* Hacked by Tito Ragusa (C) 2004 to handle usernames of whatever length and to
* be more similar to GNU id.
* -Z option support: by Yuichi Nakamura <ynakam@hitachisoft.jp>
* Added -G option Tito Ragusa (C) 2008 for SUSv3.
*/
#include "libbb.h"
#define PRINT_REAL 1
#define NAME_NOT_NUMBER 2
#define JUST_USER 4
#define JUST_GROUP 8
#define JUST_ALL_GROUPS 16
#if ENABLE_SELINUX
#define JUST_CONTEXT 32
#endif
static int printf_full(unsigned id, const char *arg, const char *prefix)
{
const char *fmt = "%s%u";
int status = EXIT_FAILURE;
if (arg) {
fmt = "%s%u(%s)";
status = EXIT_SUCCESS;
}
printf(fmt, prefix, id, arg);
return status;
}
#if (defined(__GLIBC__) && !defined(__UCLIBC__))
#define HAVE_getgrouplist 1
#elif ENABLE_USE_BB_PWD_GRP
#define HAVE_getgrouplist 1
#else
#define HAVE_getgrouplist 0
#endif
int id_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int id_main(int argc UNUSED_PARAM, char **argv)
{
const char *username;
struct passwd *p;
uid_t uid;
gid_t gid;
#if HAVE_getgrouplist
gid_t *groups;
int n;
#endif
unsigned flags;
short status;
#if ENABLE_SELINUX
security_context_t scontext;
#endif
/* Don't allow -n -r -nr -ug -rug -nug -rnug */
/* Don't allow more than one username */
opt_complementary = "?1:u--g:g--u:G--u:u--G:g--G:G--g:r?ugG:n?ugG" USE_SELINUX(":u--Z:Z--u:g--Z:Z--g");
flags = getopt32(argv, "rnugG" USE_SELINUX("Z"));
username = argv[optind];
/* This values could be overwritten later */
uid = geteuid();
gid = getegid();
if (flags & PRINT_REAL) {
uid = getuid();
gid = getgid();
}
if (username) {
#if HAVE_getgrouplist
int m;
#endif
p = getpwnam(username);
/* xuname2uid is needed because it exits on failure */
uid = xuname2uid(username);
gid = p->pw_gid; /* in this case PRINT_REAL is the same */
#if HAVE_getgrouplist
n = 16;
groups = NULL;
do {
m = n;
groups = xrealloc(groups, sizeof(groups[0]) * m);
getgrouplist(username, gid, groups, &n); /* GNUism? */
} while (n > m);
#endif
} else {
#if HAVE_getgrouplist
n = getgroups(0, NULL);
groups = xmalloc(sizeof(groups[0]) * n);
getgroups(n, groups);
#endif
}
if (flags & JUST_ALL_GROUPS) {
#if HAVE_getgrouplist
while (n--) {
if (flags & NAME_NOT_NUMBER)
printf("%s", bb_getgrgid(NULL, 0, *groups++));
else
printf("%u", (unsigned) *groups++);
bb_putchar((n > 0) ? ' ' : '\n');
}
#endif
/* exit */
fflush_stdout_and_exit(EXIT_SUCCESS);
}
if (flags & (JUST_GROUP | JUST_USER USE_SELINUX(| JUST_CONTEXT))) {
/* JUST_GROUP and JUST_USER are mutually exclusive */
if (flags & NAME_NOT_NUMBER) {
/* bb_getXXXid(-1) exits on failure, puts cannot segfault */
puts((flags & JUST_USER) ? bb_getpwuid(NULL, -1, uid) : bb_getgrgid(NULL, -1, gid));
} else {
if (flags & JUST_USER) {
printf("%u\n", (unsigned)uid);
}
if (flags & JUST_GROUP) {
printf("%u\n", (unsigned)gid);
}
}
#if ENABLE_SELINUX
if (flags & JUST_CONTEXT) {
selinux_or_die();
if (username) {
bb_error_msg_and_die("user name can't be passed with -Z");
}
if (getcon(&scontext)) {
bb_error_msg_and_die("can't get process context");
}
puts(scontext);
}
#endif
/* exit */
fflush_stdout_and_exit(EXIT_SUCCESS);
}
/* Print full info like GNU id */
/* bb_getpwuid(0) doesn't exit on failure (returns NULL) */
status = printf_full(uid, bb_getpwuid(NULL, 0, uid), "uid=");
status |= printf_full(gid, bb_getgrgid(NULL, 0, gid), " gid=");
#if HAVE_getgrouplist
{
const char *msg = " groups=";
while (n--) {
status |= printf_full(*groups, bb_getgrgid(NULL, 0, *groups), msg);
msg = ",";
groups++;
}
}
/* we leak groups vector... */
#endif
#if ENABLE_SELINUX
if (is_selinux_enabled()) {
security_context_t mysid;
getcon(&mysid);
printf(" context=%s", mysid ? mysid : "unknown");
if (mysid) /* TODO: maybe freecon(NULL) is harmless? */
freecon(mysid);
}
#endif
bb_putchar('\n');
fflush_stdout_and_exit(status);
}