busybox/coreutils/id.c

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/* vi: set sw=4 ts=4: */
/*
* Mini id implementation for busybox
*
* Copyright (C) 2000 by Randolph Chung <tausq@debian.org>
* Copyright (C) 2008 by Tito Ragusa <farmatito@tiscali.it>
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
/* 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>
2008-09-12 15:28:11 +05:30
* Added -G option Tito Ragusa (C) 2008 for SUSv3.
Tito writes: Hi Erik, Hi to all, This is part five of the my_get*id story. I've tweaked a bit this two functions to make them more flexible, but this changes will not affect existing code. Now they work so: 1) my_getpwuid( char *user, uid_t uid, int bufsize) if bufsize is > 0 char *user cannot be set to NULL on success username is written on static allocated buffer on failure uid as string is written to buffer and NULL is returned if bufsize is = 0 char *user can be set to NULL on success username is returned on failure NULL is returned if bufsize is < 0 char *user can be set to NULL on success username is returned on failure an error message is printed and the program exits 2) 1) my_getgrgid( char *group, uid_t uid, int bufsize) if bufsize is > 0 char *group cannot be set to NULL on success groupname is written on static allocated buffer on failure gid as string is written to buffer and NULL is returned if bufsize is = 0 char *group can be set to NULL on success groupname is returned on failure NULL is returned if bufsize is < 0 char *group can be set to nULL on success groupname is returned on failure an error message is printed and the program exits This changes were needed mainly for my new id applet. It is somewhat bigger then the previous but matches the behaviour of GNU id and is capable to handle usernames of whatever length. BTW: at a first look it seems to me that it will integrate well (with just a few changes) with the pending patch in patches/id_groups_alias.patch. The increase in size is balanced by the removal of my_getpwnamegid.c from libbb as this was used only in previous id applet and by size optimizations made possible in whoami.c and in passwd.c. I know that we are in feature freeze but I think that i've tested it enough (at least I hope so.......).
2004-09-03 03:51:41 +05:30
*/
//config:config ID
//config: bool "id (6.7 kb)"
//config: default y
//config: help
//config: id displays the current user and group ID names.
//config:
//config:config GROUPS
//config: bool "groups (6.5 kb)"
//config: default y
//config: help
//config: Print the group names associated with current user id.
//applet:IF_GROUPS(APPLET_NOEXEC(groups, id, BB_DIR_USR_BIN, BB_SUID_DROP, groups))
//applet:IF_ID( APPLET_NOEXEC(id, id, BB_DIR_USR_BIN, BB_SUID_DROP, id ))
//kbuild:lib-$(CONFIG_GROUPS) += id.o
//kbuild:lib-$(CONFIG_ID) += id.o
/* BB_AUDIT SUSv3 compliant. */
//usage:#define id_trivial_usage
//usage: "[OPTIONS] [USER]"
//usage:#define id_full_usage "\n\n"
//usage: "Print information about USER or the current user\n"
//usage: IF_SELINUX(
//usage: "\n -Z Security context"
//usage: )
//usage: "\n -u User ID"
//usage: "\n -g Group ID"
//usage: "\n -G Supplementary group IDs"
//usage: "\n -n Print names instead of numbers"
//usage: "\n -r Print real ID instead of effective ID"
//usage:
//usage:#define id_example_usage
//usage: "$ id\n"
//usage: "uid=1000(andersen) gid=1000(andersen)\n"
//usage:#define groups_trivial_usage
//usage: "[USER]"
//usage:#define groups_full_usage "\n\n"
//usage: "Print the group memberships of USER or for the current process"
//usage:
//usage:#define groups_example_usage
//usage: "$ groups\n"
//usage: "andersen lp dialout cdrom floppy\n"
#include "libbb.h"
Tito writes: Hi Erik, Hi to all, This is part five of the my_get*id story. I've tweaked a bit this two functions to make them more flexible, but this changes will not affect existing code. Now they work so: 1) my_getpwuid( char *user, uid_t uid, int bufsize) if bufsize is > 0 char *user cannot be set to NULL on success username is written on static allocated buffer on failure uid as string is written to buffer and NULL is returned if bufsize is = 0 char *user can be set to NULL on success username is returned on failure NULL is returned if bufsize is < 0 char *user can be set to NULL on success username is returned on failure an error message is printed and the program exits 2) 1) my_getgrgid( char *group, uid_t uid, int bufsize) if bufsize is > 0 char *group cannot be set to NULL on success groupname is written on static allocated buffer on failure gid as string is written to buffer and NULL is returned if bufsize is = 0 char *group can be set to NULL on success groupname is returned on failure NULL is returned if bufsize is < 0 char *group can be set to nULL on success groupname is returned on failure an error message is printed and the program exits This changes were needed mainly for my new id applet. It is somewhat bigger then the previous but matches the behaviour of GNU id and is capable to handle usernames of whatever length. BTW: at a first look it seems to me that it will integrate well (with just a few changes) with the pending patch in patches/id_groups_alias.patch. The increase in size is balanced by the removal of my_getpwnamegid.c from libbb as this was used only in previous id applet and by size optimizations made possible in whoami.c and in passwd.c. I know that we are in feature freeze but I think that i've tested it enough (at least I hope so.......).
2004-09-03 03:51:41 +05:30
/* This is a NOEXEC applet. Be very careful! */
#if !ENABLE_USE_BB_PWD_GRP
#if defined(__UCLIBC__) && UCLIBC_VERSION < KERNEL_VERSION(0, 9, 30)
#error "Sorry, you need at least uClibc version 0.9.30 for id applet to build"
#endif
#endif
enum {
PRINT_REAL = (1 << 0),
NAME_NOT_NUMBER = (1 << 1),
JUST_USER = (1 << 2),
JUST_GROUP = (1 << 3),
JUST_ALL_GROUPS = (1 << 4),
#if ENABLE_SELINUX
JUST_CONTEXT = (1 << 5),
#endif
};
Tito writes: Hi Erik, Hi to all, This is part five of the my_get*id story. I've tweaked a bit this two functions to make them more flexible, but this changes will not affect existing code. Now they work so: 1) my_getpwuid( char *user, uid_t uid, int bufsize) if bufsize is > 0 char *user cannot be set to NULL on success username is written on static allocated buffer on failure uid as string is written to buffer and NULL is returned if bufsize is = 0 char *user can be set to NULL on success username is returned on failure NULL is returned if bufsize is < 0 char *user can be set to NULL on success username is returned on failure an error message is printed and the program exits 2) 1) my_getgrgid( char *group, uid_t uid, int bufsize) if bufsize is > 0 char *group cannot be set to NULL on success groupname is written on static allocated buffer on failure gid as string is written to buffer and NULL is returned if bufsize is = 0 char *group can be set to NULL on success groupname is returned on failure NULL is returned if bufsize is < 0 char *group can be set to nULL on success groupname is returned on failure an error message is printed and the program exits This changes were needed mainly for my new id applet. It is somewhat bigger then the previous but matches the behaviour of GNU id and is capable to handle usernames of whatever length. BTW: at a first look it seems to me that it will integrate well (with just a few changes) with the pending patch in patches/id_groups_alias.patch. The increase in size is balanced by the removal of my_getpwnamegid.c from libbb as this was used only in previous id applet and by size optimizations made possible in whoami.c and in passwd.c. I know that we are in feature freeze but I think that i've tested it enough (at least I hope so.......).
2004-09-03 03:51:41 +05:30
static int print_common(unsigned id, const char *name, const char *prefix)
{
if (prefix) {
printf("%s", prefix);
}
if (!(option_mask32 & NAME_NOT_NUMBER) || !name) {
printf("%u", id);
}
if (!option_mask32 || (option_mask32 & NAME_NOT_NUMBER)) {
if (name) {
printf(option_mask32 ? "%s" : "(%s)", name);
} else {
/* Don't set error status flag in default mode */
if (option_mask32) {
if (ENABLE_DESKTOP)
bb_error_msg("unknown ID %u", id);
return EXIT_FAILURE;
}
}
}
return EXIT_SUCCESS;
Tito writes: Hi Erik, Hi to all, This is part five of the my_get*id story. I've tweaked a bit this two functions to make them more flexible, but this changes will not affect existing code. Now they work so: 1) my_getpwuid( char *user, uid_t uid, int bufsize) if bufsize is > 0 char *user cannot be set to NULL on success username is written on static allocated buffer on failure uid as string is written to buffer and NULL is returned if bufsize is = 0 char *user can be set to NULL on success username is returned on failure NULL is returned if bufsize is < 0 char *user can be set to NULL on success username is returned on failure an error message is printed and the program exits 2) 1) my_getgrgid( char *group, uid_t uid, int bufsize) if bufsize is > 0 char *group cannot be set to NULL on success groupname is written on static allocated buffer on failure gid as string is written to buffer and NULL is returned if bufsize is = 0 char *group can be set to NULL on success groupname is returned on failure NULL is returned if bufsize is < 0 char *group can be set to nULL on success groupname is returned on failure an error message is printed and the program exits This changes were needed mainly for my new id applet. It is somewhat bigger then the previous but matches the behaviour of GNU id and is capable to handle usernames of whatever length. BTW: at a first look it seems to me that it will integrate well (with just a few changes) with the pending patch in patches/id_groups_alias.patch. The increase in size is balanced by the removal of my_getpwnamegid.c from libbb as this was used only in previous id applet and by size optimizations made possible in whoami.c and in passwd.c. I know that we are in feature freeze but I think that i've tested it enough (at least I hope so.......).
2004-09-03 03:51:41 +05:30
}
2003-03-19 14:43:01 +05:30
static int print_group(gid_t id, const char *prefix)
{
return print_common(id, gid2group(id), prefix);
}
2008-11-05 13:45:13 +05:30
static int print_user(uid_t id, const char *prefix)
{
return print_common(id, uid2uname(id), prefix);
}
/* On error set *n < 0 and return >= 0
* If *n is too small, update it and return < 0
* (ok to trash groups[] in both cases)
* Otherwise fill in groups[] and return >= 0
*/
static int get_groups(const char *username, gid_t rgid, gid_t *groups, int *n)
{
int m;
if (username) {
/* If the user is a member of more than
* *n groups, then -1 is returned. Otherwise >= 0.
* (and no defined way of detecting errors?!) */
m = getgrouplist(username, rgid, groups, n);
/* I guess *n < 0 might indicate error. Anyway,
* malloc'ing -1 bytes won't be good, so: */
if (*n < 0)
return 0;
return m;
}
*n = getgroups(*n, groups);
if (*n >= 0)
return *n;
/* Error */
if (errno == EINVAL) /* *n is too small? */
*n = getgroups(0, groups); /* get needed *n */
/* if *n >= 0, return -1 (got new *n), else return 0 (error): */
return -(*n >= 0);
}
int id_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
2008-07-05 14:48:54 +05:30
int id_main(int argc UNUSED_PARAM, char **argv)
{
uid_t ruid;
gid_t rgid;
uid_t euid;
gid_t egid;
unsigned opt;
int i;
int status = EXIT_SUCCESS;
const char *prefix;
const char *username;
#if ENABLE_SELINUX
security_context_t scontext = NULL;
#endif
if (ENABLE_GROUPS && (!ENABLE_ID || applet_name[0] == 'g')) {
/* TODO: coreutils groups prepend "USER : " prefix,
* and accept many usernames. Example:
* # groups root root
* root : root
* root : root
*/
opt = option_mask32 = getopt32(argv, "") | JUST_ALL_GROUPS | NAME_NOT_NUMBER;
} else {
/* Don't allow -n -r -nr -ug -rug -nug -rnug -uZ -gZ -GZ*/
/* 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"
IF_SELINUX(":u--Z:Z--u:g--Z:Z--g:G--Z:Z--G");
opt = getopt32(argv, "rnugG" IF_SELINUX("Z"));
}
username = argv[optind];
if (username) {
struct passwd *p = xgetpwnam(username);
euid = ruid = p->pw_uid;
egid = rgid = p->pw_gid;
} else {
egid = getegid();
rgid = getgid();
euid = geteuid();
ruid = getuid();
2008-09-12 15:28:11 +05:30
}
/* JUST_ALL_GROUPS ignores -r PRINT_REAL flag even if man page for */
/* id says: print the real ID instead of the effective ID, with -ugG */
2008-11-05 13:48:16 +05:30
/* in fact in this case egid is always printed if egid != rgid */
if (!opt || (opt & JUST_ALL_GROUPS)) {
gid_t *groups;
int n;
if (!opt) {
/* Default Mode */
status |= print_user(ruid, "uid=");
status |= print_group(rgid, " gid=");
if (euid != ruid)
status |= print_user(euid, " euid=");
if (egid != rgid)
status |= print_group(egid, " egid=");
} else {
/* JUST_ALL_GROUPS */
status |= print_group(rgid, NULL);
if (egid != rgid)
status |= print_group(egid, " ");
}
/* We are supplying largish buffer, trying
* to not run get_groups() twice. That might be slow
* ("user database in remote SQL server" case) */
groups = xmalloc(64 * sizeof(groups[0]));
n = 64;
if (get_groups(username, rgid, groups, &n) < 0) {
/* Need bigger buffer after all */
groups = xrealloc(groups, n * sizeof(groups[0]));
get_groups(username, rgid, groups, &n);
}
if (n > 0) {
/* Print the list */
prefix = " groups=";
for (i = 0; i < n; i++) {
if (opt && (groups[i] == rgid || groups[i] == egid))
continue;
status |= print_group(groups[i], opt ? " " : prefix);
prefix = ",";
}
} else if (n < 0) { /* error in get_groups() */
if (ENABLE_DESKTOP)
bb_error_msg_and_die("can't get groups");
return EXIT_FAILURE;
}
if (ENABLE_FEATURE_CLEAN_UP)
free(groups);
#if ENABLE_SELINUX
if (is_selinux_enabled()) {
if (getcon(&scontext) == 0)
printf(" context=%s", scontext);
}
#endif
} else if (opt & PRINT_REAL) {
euid = ruid;
egid = rgid;
Tito writes: Hi Erik, Hi to all, This is part five of the my_get*id story. I've tweaked a bit this two functions to make them more flexible, but this changes will not affect existing code. Now they work so: 1) my_getpwuid( char *user, uid_t uid, int bufsize) if bufsize is > 0 char *user cannot be set to NULL on success username is written on static allocated buffer on failure uid as string is written to buffer and NULL is returned if bufsize is = 0 char *user can be set to NULL on success username is returned on failure NULL is returned if bufsize is < 0 char *user can be set to NULL on success username is returned on failure an error message is printed and the program exits 2) 1) my_getgrgid( char *group, uid_t uid, int bufsize) if bufsize is > 0 char *group cannot be set to NULL on success groupname is written on static allocated buffer on failure gid as string is written to buffer and NULL is returned if bufsize is = 0 char *group can be set to NULL on success groupname is returned on failure NULL is returned if bufsize is < 0 char *group can be set to nULL on success groupname is returned on failure an error message is printed and the program exits This changes were needed mainly for my new id applet. It is somewhat bigger then the previous but matches the behaviour of GNU id and is capable to handle usernames of whatever length. BTW: at a first look it seems to me that it will integrate well (with just a few changes) with the pending patch in patches/id_groups_alias.patch. The increase in size is balanced by the removal of my_getpwnamegid.c from libbb as this was used only in previous id applet and by size optimizations made possible in whoami.c and in passwd.c. I know that we are in feature freeze but I think that i've tested it enough (at least I hope so.......).
2004-09-03 03:51:41 +05:30
}
if (opt & JUST_USER)
status |= print_user(euid, NULL);
else if (opt & JUST_GROUP)
status |= print_group(egid, NULL);
#if ENABLE_SELINUX
else if (opt & JUST_CONTEXT) {
selinux_or_die();
if (username || getcon(&scontext)) {
bb_error_msg_and_die("can't get process context%s",
username ? " for a different user" : "");
}
fputs(scontext, stdout);
Tito writes: Hi Erik, Hi to all, This is part five of the my_get*id story. I've tweaked a bit this two functions to make them more flexible, but this changes will not affect existing code. Now they work so: 1) my_getpwuid( char *user, uid_t uid, int bufsize) if bufsize is > 0 char *user cannot be set to NULL on success username is written on static allocated buffer on failure uid as string is written to buffer and NULL is returned if bufsize is = 0 char *user can be set to NULL on success username is returned on failure NULL is returned if bufsize is < 0 char *user can be set to NULL on success username is returned on failure an error message is printed and the program exits 2) 1) my_getgrgid( char *group, uid_t uid, int bufsize) if bufsize is > 0 char *group cannot be set to NULL on success groupname is written on static allocated buffer on failure gid as string is written to buffer and NULL is returned if bufsize is = 0 char *group can be set to NULL on success groupname is returned on failure NULL is returned if bufsize is < 0 char *group can be set to nULL on success groupname is returned on failure an error message is printed and the program exits This changes were needed mainly for my new id applet. It is somewhat bigger then the previous but matches the behaviour of GNU id and is capable to handle usernames of whatever length. BTW: at a first look it seems to me that it will integrate well (with just a few changes) with the pending patch in patches/id_groups_alias.patch. The increase in size is balanced by the removal of my_getpwnamegid.c from libbb as this was used only in previous id applet and by size optimizations made possible in whoami.c and in passwd.c. I know that we are in feature freeze but I think that i've tested it enough (at least I hope so.......).
2004-09-03 03:51:41 +05:30
}
/* freecon(NULL) seems to be harmless */
if (ENABLE_FEATURE_CLEAN_UP)
freecon(scontext);
#endif
bb_putchar('\n');
2006-10-27 04:51:47 +05:30
fflush_stdout_and_exit(status);
Tito writes: Hi Erik, Hi to all, This is part five of the my_get*id story. I've tweaked a bit this two functions to make them more flexible, but this changes will not affect existing code. Now they work so: 1) my_getpwuid( char *user, uid_t uid, int bufsize) if bufsize is > 0 char *user cannot be set to NULL on success username is written on static allocated buffer on failure uid as string is written to buffer and NULL is returned if bufsize is = 0 char *user can be set to NULL on success username is returned on failure NULL is returned if bufsize is < 0 char *user can be set to NULL on success username is returned on failure an error message is printed and the program exits 2) 1) my_getgrgid( char *group, uid_t uid, int bufsize) if bufsize is > 0 char *group cannot be set to NULL on success groupname is written on static allocated buffer on failure gid as string is written to buffer and NULL is returned if bufsize is = 0 char *group can be set to NULL on success groupname is returned on failure NULL is returned if bufsize is < 0 char *group can be set to nULL on success groupname is returned on failure an error message is printed and the program exits This changes were needed mainly for my new id applet. It is somewhat bigger then the previous but matches the behaviour of GNU id and is capable to handle usernames of whatever length. BTW: at a first look it seems to me that it will integrate well (with just a few changes) with the pending patch in patches/id_groups_alias.patch. The increase in size is balanced by the removal of my_getpwnamegid.c from libbb as this was used only in previous id applet and by size optimizations made possible in whoami.c and in passwd.c. I know that we are in feature freeze but I think that i've tested it enough (at least I hope so.......).
2004-09-03 03:51:41 +05:30
}