busybox/coreutils/id.c
2006-10-05 22:50:22 +00:00

112 lines
2.7 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 _NOT_ compliant -- option -G is not currently supported. */
/* Hacked by Tito Ragusa (C) 2004 to handle usernames of whatever length and to
* be more similar to GNU id.
*/
#include "busybox.h"
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#ifdef CONFIG_SELINUX
#include <selinux/selinux.h> /* for is_selinux_enabled() */
#endif
#define PRINT_REAL 1
#define NAME_NOT_NUMBER 2
#define JUST_USER 4
#define JUST_GROUP 8
static short printf_full(unsigned int id, const char *arg, const char prefix)
{
const char *fmt = "%cid=%u";
short status = EXIT_FAILURE;
if (arg) {
fmt = "%cid=%u(%s)";
status = EXIT_SUCCESS;
}
bb_printf(fmt, prefix, id, arg);
return status;
}
int id_main(int argc, char **argv)
{
struct passwd *p;
uid_t uid;
gid_t gid;
unsigned long flags;
short status;
/* Don't allow -n -r -nr -ug -rug -nug -rnug */
/* Don't allow more than one username */
opt_complementary = "?1:?:u--g:g--u:r?ug:n?ug";
flags = getopt32(argc, argv, "rnug");
/* This values could be overwritten later */
uid = geteuid();
gid = getegid();
if (flags & PRINT_REAL) {
uid = getuid();
gid = getgid();
}
if (argv[optind]) {
p = getpwnam(argv[optind]);
/* bb_xgetpwnam is needed because it exits on failure */
uid = bb_xgetpwnam(argv[optind]);
gid = p->pw_gid;
/* in this case PRINT_REAL is the same */
}
if (flags & (JUST_GROUP | JUST_USER)) {
/* JUST_GROUP and JUST_USER are mutually exclusive */
if (flags & NAME_NOT_NUMBER) {
/* bb_getpwuid and bb_getgrgid exit on failure so puts cannot segfault */
puts((flags & JUST_USER) ? bb_getpwuid(NULL, uid, -1 ) : bb_getgrgid(NULL, gid, -1 ));
} else {
bb_printf("%u\n", (flags & JUST_USER) ? uid : gid);
}
/* exit */
bb_fflush_stdout_and_exit(EXIT_SUCCESS);
}
/* Print full info like GNU id */
/* bb_getpwuid doesn't exit on failure here */
status = printf_full(uid, bb_getpwuid(NULL, uid, 0), 'u');
putchar(' ');
/* bb_getgrgid doesn't exit on failure here */
status |= printf_full(gid, bb_getgrgid(NULL, gid, 0), 'g');
#ifdef CONFIG_SELINUX
if (is_selinux_enabled()) {
security_context_t mysid;
char context[80];
int len = sizeof(context);
getcon(&mysid);
context[0] = '\0';
if (mysid) {
len = strlen(mysid)+1;
safe_strncpy(context, mysid, len);
freecon(mysid);
} else {
safe_strncpy(context, "unknown", 8);
}
bb_printf(" context=%s", context);
}
#endif
putchar('\n');
bb_fflush_stdout_and_exit(status);
}