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subids: support nsswitch 

Closes #154

When starting any operation to do with subuid delegation, check
nsswitch for a module to use.  If none is specified, then use
the traditional /etc/subuid and /etc/subgid files.

Currently only one module is supported, and there is no fallback
to the files on errors.  Several possibilities could be considered:

1. in case of connection error, fall back to files
2. in case of unknown user, also fall back to files

etc...

When non-files nss module is used, functions to edit the range
are not supported.  It may make sense to support it, but it also
may make sense to require another tool to be used.

libsubordinateio also uses the nss_ helpers.  This is how for instance
lxc could easily be converted to supporting nsswitch.

Add a set of test cases, including a dummy libsubid_zzz module.  This
hardcodes values such that:

'ubuntu' gets 200000 - 300000
'user1' gets 100000 - 165536
'error' emulates an nss module error
'unknown' emulates a user unknown to the nss module
'conn' emulates a connection error ot the nss module

Changes to libsubid:

Change the list_owner_ranges api: return a count instead of making the array
null terminated.

This is a breaking change, so bump the libsubid abi major number.

Rename free_subuid_range and free_subgid_range to ungrant_subuid_range,
because otherwise it's confusing with free_subid_ranges which frees
    memory.

Run libsubid tests in jenkins

Switch argument order in find_subid_owners

Move the db locking into subordinateio.c

Signed-off-by: Serge Hallyn <serge@hallyn.com>
This commit is contained in:
Serge Hallyn 2021-01-31 17:38:20 -06:00
parent 514c1328b6
commit 8492dee663
26 changed files with 935 additions and 205 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
.travis.yml
View File

@ -16,6 +16,7 @@ arch:
before_install:
- sudo apt-get update -qq
- sudo apt-get -y install -qq automake autopoint xsltproc libselinux1-dev gettext expect
- sudo apt-get -y install -qq byacc libtool
script:
- ./autogen.sh --without-selinux --disable-man
- grep ENABLE_ config.status

2
configure.ac
View File

@ -1,6 +1,6 @@
dnl Process this file with autoconf to produce a configure script.
AC_PREREQ([2.69])
m4_define([libsubid_abi_major], 1)
m4_define([libsubid_abi_major], 2)
m4_define([libsubid_abi_minor], 0)
m4_define([libsubid_abi_micro], 0)
m4_define([libsubid_abi], [libsubid_abi_major.libsubid_abi_minor.libsubid_abi_micro])

1
lib/Makefile.am
View File

@ -31,6 +31,7 @@ libshadow_la_SOURCES = \
groupio.h \
gshadow.c \
lockpw.c \
nss.c \
nscd.c \
nscd.h \
sssd.c \

157
lib/nss.c Normal file
View File

@ -0,0 +1,157 @@
#include <stdio.h>
#include <stdlib.h>
#include <dlfcn.h>
#include <stdbool.h>
#include <string.h>
#include <strings.h>
#include <ctype.h>
#include <stdatomic.h>
#include "prototypes.h"
#include "../libsubid/subid.h"
#define NSSWITCH "/etc/nsswitch.conf"
// NSS plugin handling for subids
// If nsswitch has a line like
// subid: sssd
// then sssd will be consulted for subids. Unlike normal NSS dbs,
// only one db is supported at a time. That's open to debate, but
// the subids are a pretty limited resource, and local files seem
// bound to step on any other allocations leading to insecure
// conditions.
static atomic_flag nss_init_started;
static atomic_bool nss_init_completed;
static struct subid_nss_ops *subid_nss;
bool nss_is_initialized() {
return atomic_load(&nss_init_completed);
}
void nss_exit() {
if (nss_is_initialized() && subid_nss) {
dlclose(subid_nss->handle);
free(subid_nss);
subid_nss = NULL;
}
}
// nsswitch_path is an argument only to support testing.
void nss_init(char *nsswitch_path) {
FILE *nssfp = NULL;
char *line = NULL, *p, *token, *saveptr;
size_t len = 0;
if (atomic_flag_test_and_set(&nss_init_started)) {
// Another thread has started nss_init, wait for it to complete
while (!atomic_load(&nss_init_completed))
usleep(100);
return;
}
if (!nsswitch_path)
nsswitch_path = NSSWITCH;
// read nsswitch.conf to check for a line like:
// subid: files
nssfp = fopen(nsswitch_path, "r");
if (!nssfp) {
fprintf(stderr, "Failed opening %s: %m", nsswitch_path);
atomic_store(&nss_init_completed, true);
return;
}
while ((getline(&line, &len, nssfp)) != -1) {
if (line[0] == '\0' || line[0] == '#')
continue;
if (strlen(line) < 8)
continue;
if (strncasecmp(line, "subid:", 6) != 0)
continue;
p = &line[6];
while ((*p) && isspace(*p))
p++;
if (!*p)
continue;
for (token = strtok_r(p, " \n\t", &saveptr);
token;
token = strtok_r(NULL, " \n\t", &saveptr)) {
char libname[65];
void *h;
if (strcmp(token, "files") == 0) {
subid_nss = NULL;
goto done;
}
if (strlen(token) > 50) {
fprintf(stderr, "Subid NSS module name too long (longer than 50 characters): %s\n", token);
fprintf(stderr, "Using files\n");
subid_nss = NULL;
goto done;
}
snprintf(libname, 64, "libsubid_%s.so", token);
h = dlopen(libname, RTLD_LAZY);
if (!h) {
fprintf(stderr, "Error opening %s: %s\n", libname, dlerror());
fprintf(stderr, "Using files\n");
subid_nss = NULL;
goto done;
}
subid_nss = malloc(sizeof(*subid_nss));
if (!subid_nss) {
dlclose(h);
goto done;
}
subid_nss->has_range = dlsym(h, "shadow_subid_has_range");
if (!subid_nss->has_range) {
fprintf(stderr, "%s did not provide @has_range@\n", libname);
dlclose(h);
free(subid_nss);
subid_nss = NULL;
goto done;
}
subid_nss->list_owner_ranges = dlsym(h, "shadow_subid_list_owner_ranges");
if (!subid_nss->list_owner_ranges) {
fprintf(stderr, "%s did not provide @list_owner_ranges@\n", libname);
dlclose(h);
free(subid_nss);
subid_nss = NULL;
goto done;
}
subid_nss->has_any_range = dlsym(h, "shadow_subid_has_any_range");
if (!subid_nss->has_any_range) {
fprintf(stderr, "%s did not provide @has_any_range@\n", libname);
dlclose(h);
free(subid_nss);
subid_nss = NULL;
goto done;
}
subid_nss->find_subid_owners = dlsym(h, "shadow_subid_find_subid_owners");
if (!subid_nss->find_subid_owners) {
fprintf(stderr, "%s did not provide @find_subid_owners@\n", libname);
dlclose(h);
free(subid_nss);
subid_nss = NULL;
goto done;
}
subid_nss->handle = h;
goto done;
}
fprintf(stderr, "No usable subid NSS module found, using files\n");
// subid_nss has to be null here, but to ease reviews:
free(subid_nss);
subid_nss = NULL;
goto done;
}
done:
atomic_store(&nss_init_completed, true);
free(line);
if (nssfp) {
atexit(nss_exit);
fclose(nssfp);
}
}
struct subid_nss_ops *get_subid_nss_handle() {
nss_init(NULL);
return subid_nss;
}

69
lib/prototypes.h
View File

@ -262,6 +262,75 @@ extern void motd (void);
/* myname.c */
extern /*@null@*//*@only@*/struct passwd *get_my_pwent (void);
/* nss.c */
#include <libsubid/subid.h>
extern void nss_init(char *nsswitch_path);
extern bool nss_is_initialized();
struct subid_nss_ops {
/*
* nss_has_any_range: does a user own any subid range
*
* @owner: username
* @idtype: subuid or subgid
* @result: true if a subid allocation was found for @owner
*
* returns success if the module was able to determine an answer (true or false),
* else an error status.
*/
enum subid_status (*has_any_range)(const char *owner, enum subid_type idtype, bool *result);
/*
* nss_has_range: does a user own a given subid range
*
* @owner: username
* @start: first subid in queried range
* @count: number of subids in queried range
* @idtype: subuid or subgid
* @result: true if @owner has been allocated the subid range.
*
* returns success if the module was able to determine an answer (true or false),
* else an error status.
*/
enum subid_status (*has_range)(const char *owner, unsigned long start, unsigned long count, enum subid_type idtype, bool *result);
/*
* nss_list_owner_ranges: list the subid ranges delegated to a user.
*
* @owner - string representing username being queried
* @id_type - subuid or subgid
* @ranges - pointer to an array of struct subordinate_range pointers, or
* NULL. The returned array of struct subordinate_range and its
* members must be freed by the caller.
* @count - pointer to an integer into which the number of returned ranges
* is written.
* returns success if the module was able to determine an answer,
* else an error status.
*/
enum subid_status (*list_owner_ranges)(const char *owner, enum subid_type id_type, struct subordinate_range ***ranges, int *count);
/*
* nss_find_subid_owners: find uids who own a given subuid or subgid.
*
* @id - the delegated id (subuid or subgid) being queried
* @id_type - subuid or subgid
* @uids - pointer to an array of uids which will be allocated by
* nss_find_subid_owners()
* @count - number of uids found
*
* returns success if the module was able to determine an answer,
* else an error status.
*/
enum subid_status (*find_subid_owners)(unsigned long id, enum subid_type id_type, uid_t **uids, int *count);
/* The dlsym handle to close */
void *handle;
};
extern struct subid_nss_ops *get_subid_nss_handle();
/* pam_pass_non_interactive.c */
#ifdef USE_PAM
extern int do_pam_passwd_non_interactive (const char *pam_service,

256
lib/subordinateio.c
View File

@ -14,6 +14,7 @@
#include <sys/types.h>
#include <pwd.h>
#include <ctype.h>
#include <fcntl.h>
/*
* subordinate_dup: create a duplicate range
@ -311,17 +312,17 @@ static bool append_range(struct subordinate_range ***ranges, const struct subord
{
struct subordinate_range *tmp;
if (!*ranges) {
*ranges = malloc(2 * sizeof(struct subordinate_range **));
*ranges = malloc(sizeof(struct subordinate_range *));
if (!*ranges)
return false;
} else {
struct subordinate_range **new;
new = realloc(*ranges, (n + 2) * (sizeof(struct subordinate_range **)));
new = realloc(*ranges, (n + 1) * (sizeof(struct subordinate_range *)));
if (!new)
return false;
*ranges = new;
}
(*ranges)[n] = (*ranges)[n+1] = NULL;
(*ranges)[n] = NULL;
tmp = subordinate_dup(new);
if (!tmp)
return false;
@ -329,13 +330,13 @@ static bool append_range(struct subordinate_range ***ranges, const struct subord
return true;
}
void free_subordinate_ranges(struct subordinate_range **ranges)
void free_subordinate_ranges(struct subordinate_range **ranges, int count)
{
int i;
if (!ranges)
return;
for (i = 0; ranges[i]; i++)
for (i = 0; i < count; i++)
subordinate_free(ranges[i]);
free(ranges);
}
@ -602,21 +603,46 @@ int sub_uid_open (int mode)
bool sub_uid_assigned(const char *owner)
{
struct subid_nss_ops *h;
bool found;
enum subid_status status;
h = get_subid_nss_handle();
if (h) {
status = h->has_any_range(owner, ID_TYPE_UID, &found);
if (status == SUBID_STATUS_SUCCESS && found)
return true;
return false;
}
return range_exists (&subordinate_uid_db, owner);
}
bool have_sub_uids(const char *owner, uid_t start, unsigned long count)
{
struct subid_nss_ops *h;
bool found;
enum subid_status status;
h = get_subid_nss_handle();
if (h) {
status = h->has_range(owner, start, count, ID_TYPE_UID, &found);
if (status == SUBID_STATUS_SUCCESS && found)
return true;
return false;
}
return have_range (&subordinate_uid_db, owner, start, count);
}
int sub_uid_add (const char *owner, uid_t start, unsigned long count)
{
if (get_subid_nss_handle())
return -EOPNOTSUPP;
return add_range (&subordinate_uid_db, owner, start, count);
}
int sub_uid_remove (const char *owner, uid_t start, unsigned long count)
{
if (get_subid_nss_handle())
return -EOPNOTSUPP;
return remove_range (&subordinate_uid_db, owner, start, count);
}
@ -684,21 +710,45 @@ int sub_gid_open (int mode)
bool have_sub_gids(const char *owner, gid_t start, unsigned long count)
{
struct subid_nss_ops *h;
bool found;
enum subid_status status;
h = get_subid_nss_handle();
if (h) {
status = h->has_range(owner, start, count, ID_TYPE_GID, &found);
if (status == SUBID_STATUS_SUCCESS && found)
return true;
return false;
}
return have_range(&subordinate_gid_db, owner, start, count);
}
bool sub_gid_assigned(const char *owner)
{
struct subid_nss_ops *h;
bool found;
enum subid_status status;
h = get_subid_nss_handle();
if (h) {
status = h->has_any_range(owner, ID_TYPE_GID, &found);
if (status == SUBID_STATUS_SUCCESS && found)
return true;
return false;
}
return range_exists (&subordinate_gid_db, owner);
}
int sub_gid_add (const char *owner, gid_t start, unsigned long count)
{
if (get_subid_nss_handle())
return -EOPNOTSUPP;
return add_range (&subordinate_gid_db, owner, start, count);
}
int sub_gid_remove (const char *owner, gid_t start, unsigned long count)
{
if (get_subid_nss_handle())
return -EOPNOTSUPP;
return remove_range (&subordinate_gid_db, owner, start, count);
}
@ -720,42 +770,78 @@ gid_t sub_gid_find_free_range(gid_t min, gid_t max, unsigned long count)
}
/*
struct subordinate_range **list_owner_ranges(const char *owner, enum subid_type id_type)
* int list_owner_ranges(const char *owner, enum subid_type id_type, struct subordinate_range ***ranges)
*
* @owner: username
* @id_type: UID or GUID
* @ranges: pointer to array of ranges into which results will be placed.
*
* Returns the subuid or subgid ranges which are owned by the specified
* Fills in the subuid or subgid ranges which are owned by the specified
* user. Username may be a username or a string representation of a
* UID number. If id_type is UID, then subuids are returned, else
* subgids are returned. If there is an error, < 0 is returned.
* subgids are given.
* Returns the number of ranges found, or < 0 on error.
*
* The caller must free the subordinate range list.
*/
struct subordinate_range **list_owner_ranges(const char *owner, enum subid_type id_type)
int list_owner_ranges(const char *owner, enum subid_type id_type, struct subordinate_range ***in_ranges)
{
// TODO - need to handle owner being either uid or username
const struct subordinate_range *range;
struct subordinate_range **ranges = NULL;
const struct subordinate_range *range;
struct commonio_db *db;
int size = 0;
enum subid_status status;
int count = 0;
struct subid_nss_ops *h;
if (id_type == ID_TYPE_UID)
*in_ranges = NULL;
h = get_subid_nss_handle();
if (h) {
status = h->list_owner_ranges(owner, id_type, in_ranges, &count);
if (status == SUBID_STATUS_SUCCESS)
return count;
return -1;
}
switch (id_type) {
case ID_TYPE_UID:
if (!sub_uid_open(O_RDONLY)) {
return -1;
}
db = &subordinate_uid_db;
else
break;
case ID_TYPE_GID:
if (!sub_gid_open(O_RDONLY)) {
return -1;
}
db = &subordinate_gid_db;
break;
default:
return -1;
}
commonio_rewind(db);
while ((range = commonio_next(db)) != NULL) {
if (0 == strcmp(range->owner, owner)) {
if (!append_range(&ranges, range, size++)) {
free_subordinate_ranges(ranges);
return NULL;
if (!append_range(&ranges, range, count++)) {
free_subordinate_ranges(ranges, count-1);
ranges = NULL;
count = -1;
goto out;
}
}
}
return ranges;
out:
if (id_type == ID_TYPE_UID)
sub_uid_close();
else
sub_gid_close();
*in_ranges = ranges;
return count;
}
static bool all_digits(const char *str)
@ -808,17 +894,41 @@ static int append_uids(uid_t **uids, const char *owner, int n)
return n+1;
}
int find_subid_owners(unsigned long id, uid_t **uids, enum subid_type id_type)
int find_subid_owners(unsigned long id, enum subid_type id_type, uid_t **uids)
{
const struct subordinate_range *range;
struct subid_nss_ops *h;
enum subid_status status;
struct commonio_db *db;
int n = 0;
*uids = NULL;
if (id_type == ID_TYPE_UID)
h = get_subid_nss_handle();
if (h) {
status = h->find_subid_owners(id, id_type, uids, &n);
// Several ways we could handle the error cases here.
if (status != SUBID_STATUS_SUCCESS)
return -1;
return n;
}
switch (id_type) {
case ID_TYPE_UID:
if (!sub_uid_open(O_RDONLY)) {
return -1;
}
db = &subordinate_uid_db;
else
break;
case ID_TYPE_GID:
if (!sub_gid_open(O_RDONLY)) {
return -1;
}
db = &subordinate_gid_db;
break;
default:
return -1;
}
*uids = NULL;
commonio_rewind(db);
while ((range = commonio_next(db)) != NULL) {
@ -829,6 +939,11 @@ int find_subid_owners(unsigned long id, uid_t **uids, enum subid_type id_type)
}
}
if (id_type == ID_TYPE_UID)
sub_uid_close();
else
sub_gid_close();
return n;
}
@ -836,11 +951,40 @@ bool new_subid_range(struct subordinate_range *range, enum subid_type id_type, b
{
struct commonio_db *db;
const struct subordinate_range *r;
bool ret;
if (id_type == ID_TYPE_UID)
if (get_subid_nss_handle())
return false;
switch (id_type) {
case ID_TYPE_UID:
if (!sub_uid_lock()) {
printf("Failed loging subuids (errno %d)\n", errno);
return false;
}
if (!sub_uid_open(O_CREAT | O_RDWR)) {
printf("Failed opening subuids (errno %d)\n", errno);
sub_uid_unlock();
return false;
}
db = &subordinate_uid_db;
else
break;
case ID_TYPE_GID:
if (!sub_gid_lock()) {
printf("Failed loging subgids (errno %d)\n", errno);
return false;
}
if (!sub_gid_open(O_CREAT | O_RDWR)) {
printf("Failed opening subgids (errno %d)\n", errno);
sub_gid_unlock();
return false;
}
db = &subordinate_gid_db;
break;
default:
return false;
}
commonio_rewind(db);
if (reuse) {
while ((r = commonio_next(db)) != NULL) {
@ -856,20 +1000,74 @@ bool new_subid_range(struct subordinate_range *range, enum subid_type id_type, b
}
range->start = find_free_range(db, range->start, ULONG_MAX, range->count);
if (range->start == ULONG_MAX)
return false;
return add_range(db, range->owner, range->start, range->count) == 1;
if (range->start == ULONG_MAX) {
ret = false;
goto out;
}
ret = add_range(db, range->owner, range->start, range->count) == 1;
out:
if (id_type == ID_TYPE_UID) {
sub_uid_close();
sub_uid_unlock();
} else {
sub_gid_close();
sub_gid_unlock();
}
return ret;
}
bool release_subid_range(struct subordinate_range *range, enum subid_type id_type)
{
struct commonio_db *db;
if (id_type == ID_TYPE_UID)
bool ret;
if (get_subid_nss_handle())
return false;
switch (id_type) {
case ID_TYPE_UID:
if (!sub_uid_lock()) {
printf("Failed loging subuids (errno %d)\n", errno);
return false;
}
if (!sub_uid_open(O_CREAT | O_RDWR)) {
printf("Failed opening subuids (errno %d)\n", errno);
sub_uid_unlock();
return false;
}
db = &subordinate_uid_db;
else
break;
case ID_TYPE_GID:
if (!sub_gid_lock()) {
printf("Failed loging subgids (errno %d)\n", errno);
return false;
}
if (!sub_gid_open(O_CREAT | O_RDWR)) {
printf("Failed opening subgids (errno %d)\n", errno);
sub_gid_unlock();
return false;
}
db = &subordinate_gid_db;
return remove_range(db, range->owner, range->start, range->count) == 1;
break;
default:
return false;
}
ret = remove_range(db, range->owner, range->start, range->count) == 1;
if (id_type == ID_TYPE_UID) {
sub_uid_close();
sub_uid_unlock();
} else {
sub_gid_close();
sub_gid_unlock();
}
return ret;
}
#else /* !ENABLE_SUBIDS */

6
lib/subordinateio.h
View File

@ -25,11 +25,11 @@ extern int sub_uid_unlock (void);
extern int sub_uid_add (const char *owner, uid_t start, unsigned long count);
extern int sub_uid_remove (const char *owner, uid_t start, unsigned long count);
extern uid_t sub_uid_find_free_range(uid_t min, uid_t max, unsigned long count);
extern struct subordinate_range **list_owner_ranges(const char *owner, enum subid_type id_type);
extern int list_owner_ranges(const char *owner, enum subid_type id_type, struct subordinate_range ***ranges);
extern bool new_subid_range(struct subordinate_range *range, enum subid_type id_type, bool reuse);
extern bool release_subid_range(struct subordinate_range *range, enum subid_type id_type);
extern int find_subid_owners(unsigned long id, uid_t **uids, enum subid_type id_type);
extern void free_subordinate_ranges(struct subordinate_range **ranges);
extern int find_subid_owners(unsigned long id, enum subid_type id_type, uid_t **uids);
extern void free_subordinate_ranges(struct subordinate_range **ranges, int count);
extern int sub_gid_close(void);
extern bool have_sub_gids(const char *owner, gid_t start, unsigned long count);

2
libmisc/idmapping.h
View File

@ -40,5 +40,7 @@ extern struct map_range *get_map_ranges(int ranges, int argc, char **argv);
extern void write_mapping(int proc_dir_fd, int ranges,
struct map_range *mappings, const char *map_file, uid_t ruid);
extern void nss_init(char *nsswitch_path);
#endif /* _ID_MAPPING_H_ */

2
libsubid/Makefile.am
View File

@ -19,7 +19,7 @@ MISCLIBS = \
libsubid_la_LIBADD = \
$(top_srcdir)/lib/libshadow.la \
$(top_srcdir)/libmisc/libmisc.la \
$(MISCLIBS)
$(MISCLIBS) -ldl
AM_CPPFLAGS = \
-I${top_srcdir}/lib \

168
libsubid/api.c
View File

@ -38,132 +38,48 @@
#include "idmapping.h"
#include "api.h"
static struct subordinate_range **get_subid_ranges(const char *owner, enum subid_type id_type)
static
int get_subid_ranges(const char *owner, enum subid_type id_type, struct subordinate_range ***ranges)
{
struct subordinate_range **ranges = NULL;
switch (id_type) {
case ID_TYPE_UID:
if (!sub_uid_open(O_RDONLY)) {
return NULL;
}
break;
case ID_TYPE_GID:
if (!sub_gid_open(O_RDONLY)) {
return NULL;
}
break;
default:
return NULL;
}
ranges = list_owner_ranges(owner, id_type);
if (id_type == ID_TYPE_UID)
sub_uid_close();
else
sub_gid_close();
return ranges;
return list_owner_ranges(owner, id_type, ranges);
}
struct subordinate_range **get_subuid_ranges(const char *owner)
int get_subuid_ranges(const char *owner, struct subordinate_range ***ranges)
{
return get_subid_ranges(owner, ID_TYPE_UID);
return get_subid_ranges(owner, ID_TYPE_UID, ranges);
}
struct subordinate_range **get_subgid_ranges(const char *owner)
int get_subgid_ranges(const char *owner, struct subordinate_range ***ranges)
{
return get_subid_ranges(owner, ID_TYPE_GID);
return get_subid_ranges(owner, ID_TYPE_GID, ranges);
}
void subid_free_ranges(struct subordinate_range **ranges)
void subid_free_ranges(struct subordinate_range **ranges, int count)
{
return free_subordinate_ranges(ranges);
return free_subordinate_ranges(ranges, count);
}
int get_subid_owner(unsigned long id, uid_t **owner, enum subid_type id_type)
static
int get_subid_owner(unsigned long id, enum subid_type id_type, uid_t **owner)
{
int ret = -1;
switch (id_type) {
case ID_TYPE_UID:
if (!sub_uid_open(O_RDONLY)) {
return -1;
}
break;
case ID_TYPE_GID:
if (!sub_gid_open(O_RDONLY)) {
return -1;
}
break;
default:
return -1;
}
ret = find_subid_owners(id, owner, id_type);
if (id_type == ID_TYPE_UID)
sub_uid_close();
else
sub_gid_close();
return ret;
return find_subid_owners(id, id_type, owner);
}
int get_subuid_owners(uid_t uid, uid_t **owner)
{
return get_subid_owner((unsigned long)uid, owner, ID_TYPE_UID);
return get_subid_owner((unsigned long)uid, ID_TYPE_UID, owner);
}
int get_subgid_owners(gid_t gid, uid_t **owner)
{
return get_subid_owner((unsigned long)gid, owner, ID_TYPE_GID);
return get_subid_owner((unsigned long)gid, ID_TYPE_GID, owner);
}
static
bool grant_subid_range(struct subordinate_range *range, bool reuse,
enum subid_type id_type)
{
bool ret;
switch (id_type) {
case ID_TYPE_UID:
if (!sub_uid_lock()) {
printf("Failed loging subuids (errno %d)\n", errno);
return false;
}
if (!sub_uid_open(O_CREAT | O_RDWR)) {
printf("Failed opening subuids (errno %d)\n", errno);
sub_uid_unlock();
return false;
}
break;
case ID_TYPE_GID:
if (!sub_gid_lock()) {
printf("Failed loging subgids (errno %d)\n", errno);
return false;
}
if (!sub_gid_open(O_CREAT | O_RDWR)) {
printf("Failed opening subgids (errno %d)\n", errno);
sub_gid_unlock();
return false;
}
break;
default:
return false;
}
ret = new_subid_range(range, id_type, reuse);
if (id_type == ID_TYPE_UID) {
sub_uid_close();
sub_uid_unlock();
} else {
sub_gid_close();
sub_gid_unlock();
}
return ret;
return new_subid_range(range, id_type, reuse);
}
bool grant_subuid_range(struct subordinate_range *range, bool reuse)
@ -176,56 +92,18 @@ bool grant_subgid_range(struct subordinate_range *range, bool reuse)
return grant_subid_range(range, reuse, ID_TYPE_GID);
}
bool free_subid_range(struct subordinate_range *range, enum subid_type id_type)
static
bool ungrant_subid_range(struct subordinate_range *range, enum subid_type id_type)
{
bool ret;
switch (id_type) {
case ID_TYPE_UID:
if (!sub_uid_lock()) {
printf("Failed loging subuids (errno %d)\n", errno);
return false;
}
if (!sub_uid_open(O_CREAT | O_RDWR)) {
printf("Failed opening subuids (errno %d)\n", errno);
sub_uid_unlock();
return false;
}
break;
case ID_TYPE_GID:
if (!sub_gid_lock()) {
printf("Failed loging subgids (errno %d)\n", errno);
return false;
}
if (!sub_gid_open(O_CREAT | O_RDWR)) {
printf("Failed opening subgids (errno %d)\n", errno);
sub_gid_unlock();
return false;
}
break;
default:
return false;
}
ret = release_subid_range(range, id_type);
if (id_type == ID_TYPE_UID) {
sub_uid_close();
sub_uid_unlock();
} else {
sub_gid_close();
sub_gid_unlock();
}
return ret;
return release_subid_range(range, id_type);
}
bool free_subuid_range(struct subordinate_range *range)
bool ungrant_subuid_range(struct subordinate_range *range)
{
return free_subid_range(range, ID_TYPE_UID);
return ungrant_subid_range(range, ID_TYPE_UID);
}
bool free_subgid_range(struct subordinate_range *range)
bool ungrant_subgid_range(struct subordinate_range *range)
{
return free_subid_range(range, ID_TYPE_GID);
return ungrant_subid_range(range, ID_TYPE_GID);
}

10
libsubid/api.h
View File

@ -1,9 +1,9 @@
#include "subid.h"
#include <stdbool.h>
struct subordinate_range **get_subuid_ranges(const char *owner);
struct subordinate_range **get_subgid_ranges(const char *owner);
void subid_free_ranges(struct subordinate_range **ranges);
int get_subuid_ranges(const char *owner, struct subordinate_range ***ranges);
int get_subgid_ranges(const char *owner, struct subordinate_range ***ranges);
void subid_free_ranges(struct subordinate_range **ranges, int count);
int get_subuid_owners(uid_t uid, uid_t **owner);
int get_subgid_owners(gid_t gid, uid_t **owner);
@ -13,5 +13,5 @@ int get_subgid_owners(gid_t gid, uid_t **owner);
bool grant_subuid_range(struct subordinate_range *range, bool reuse);
bool grant_subgid_range(struct subordinate_range *range, bool reuse);
bool free_subuid_range(struct subordinate_range *range);
bool free_subgid_range(struct subordinate_range *range);
bool ungrant_subuid_range(struct subordinate_range *range);
bool ungrant_subgid_range(struct subordinate_range *range);

8
libsubid/subid.h
View File

@ -1,4 +1,5 @@
#include <sys/types.h>
#include <stdbool.h>
#ifndef SUBID_RANGE_DEFINED
#define SUBID_RANGE_DEFINED 1
@ -13,5 +14,12 @@ enum subid_type {
ID_TYPE_GID = 2
};
enum subid_status {
SUBID_STATUS_SUCCESS = 0,
SUBID_STATUS_UNKNOWN_USER = 1,
SUBID_STATUS_ERROR_CONN = 2,
SUBID_STATUS_ERROR = 3,
};
#define SUBID_NFIELDS 3
#endif

29
src/Makefile.am
View File

@ -111,15 +111,6 @@ grpck_LDADD = $(LDADD) $(LIBAUDIT) $(LIBSELINUX) $(LIBECONF)
grpconv_LDADD = $(LDADD) $(LIBAUDIT) $(LIBSELINUX) $(LIBECONF)
grpunconv_LDADD = $(LDADD) $(LIBAUDIT) $(LIBSELINUX) $(LIBECONF)
lastlog_LDADD = $(LDADD) $(LIBAUDIT) $(LIBECONF)
newuidmap_SOURCES = newuidmap.c ../libmisc/nss.c
newgidmap_SOURCES = newgidmap.c ../libmisc/nss.c
groupadd_SOURCES = groupadd.c ../libmisc/nss.c
groupmod_SOURCES = groupmod.c ../libmisc/nss.c
groupdel_SOURCES = groupdel.c ../libmisc/nss.c
newusers_SOURCES = newusers.c ../libmisc/nss.c
useradd_SOURCES = useradd.c ../libmisc/nss.c
usermod_SOURCES = usermod.c ../libmisc/nss.c
userdel_SOURCES = userdel.c ../libmisc/nss.c
login_SOURCES = \
login.c \
login_nopam.c
@ -169,7 +160,8 @@ endif
noinst_PROGRAMS += list_subid_ranges \
get_subid_owners \
new_subid_range \
free_subid_range
free_subid_range \
check_subid_range
MISCLIBS = \
$(LIBAUDIT) \
@ -186,7 +178,7 @@ list_subid_ranges_LDADD = \
$(top_builddir)/lib/libshadow.la \
$(top_builddir)/libmisc/libmisc.la \
$(top_builddir)/libsubid/libsubid.la \
$(MISCLIBS)
$(MISCLIBS) -ldl
list_subid_ranges_CPPFLAGS = \
-I$(top_srcdir)/lib \
@ -197,7 +189,7 @@ get_subid_owners_LDADD = \
$(top_builddir)/lib/libshadow.la \
$(top_builddir)/libmisc/libmisc.la \
$(top_builddir)/libsubid/libsubid.la \
$(MISCLIBS)
$(MISCLIBS) -ldl
get_subid_owners_CPPFLAGS = \
-I$(top_srcdir)/lib \
@ -213,7 +205,7 @@ new_subid_range_LDADD = \
$(top_builddir)/lib/libshadow.la \
$(top_builddir)/libmisc/libmisc.la \
$(top_builddir)/libsubid/libsubid.la \
$(MISCLIBS)
$(MISCLIBS) -ldl
free_subid_range_CPPFLAGS = \
-I$(top_srcdir)/lib \
@ -224,5 +216,14 @@ free_subid_range_LDADD = \
$(top_builddir)/lib/libshadow.la \
$(top_builddir)/libmisc/libmisc.la \
$(top_builddir)/libsubid/libsubid.la \
$(MISCLIBS)
$(MISCLIBS) -ldl
check_subid_range_CPPFLAGS = \
-I$(top_srcdir)/lib \
-I$(top_srcdir)/libmisc
check_subid_range_LDADD = \
$(top_builddir)/lib/libshadow.la \
$(top_builddir)/libmisc/libmisc.la \
$(MISCLIBS) -ldl
endif

48
src/check_subid_range.c Normal file
View File

@ -0,0 +1,48 @@
// This program is for testing purposes only.
// usage is "[program] owner [u|g] start count
// Exits 0 if owner has subid range starting start, of size count
// Exits 1 otherwise.
#include <config.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <stdbool.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "defines.h"
#include "prototypes.h"
#include "subordinateio.h"
#include "idmapping.h"
const char *Prog;
int main(int argc, char **argv)
{
char *owner;
unsigned long start, count;
bool check_uids;
Prog = Basename (argv[0]);
if (argc != 5)
exit(1);
owner = argv[1];
check_uids = argv[2][0] == 'u';
start = strtoul(argv[3], NULL, 10);
if (start == ULONG_MAX && errno == ERANGE)
exit(1);
count = strtoul(argv[4], NULL, 10);
if (count == ULONG_MAX && errno == ERANGE)
exit(1);
if (check_uids) {
if (have_sub_uids(owner, start, count))
exit(0);
exit(1);
}
if (have_sub_gids(owner, start, count))
exit(0);
exit(1);
}

4
src/free_subid_range.c
View File

@ -37,9 +37,9 @@ int main(int argc, char *argv[])
range.start = atoi(argv[1]);
range.count = atoi(argv[2]);
if (group)
ok = free_subgid_range(&range);
ok = ungrant_subgid_range(&range);
else
ok = free_subuid_range(&range);
ok = ungrant_subuid_range(&range);
if (!ok) {
fprintf(stderr, "Failed freeing id range\n");

10
src/list_subid_ranges.c
View File

@ -15,7 +15,7 @@ void usage(void)
int main(int argc, char *argv[])
{
int i;
int i, count=0;
struct subordinate_range **ranges;
Prog = Basename (argv[0]);
@ -23,19 +23,19 @@ int main(int argc, char *argv[])
usage();
}
if (argc == 3 && strcmp(argv[1], "-g") == 0)
ranges = get_subgid_ranges(argv[2]);
count = get_subgid_ranges(argv[2], &ranges);
else if (argc == 2 && strcmp(argv[1], "-h") == 0)
usage();
else
ranges = get_subuid_ranges(argv[1]);
count = get_subuid_ranges(argv[1], &ranges);
if (!ranges) {
fprintf(stderr, "Error fetching ranges\n");
exit(1);
}
for (i = 0; ranges[i]; i++) {
for (i = 0; i < count; i++) {
printf("%d: %s %lu %lu\n", i, ranges[i]->owner,
ranges[i]->start, ranges[i]->count);
}
subid_free_ranges(ranges);
subid_free_ranges(ranges, count);
return 0;
}

12
tests/libsubid/04_nss/Makefile Normal file
View File

@ -0,0 +1,12 @@
all: test_nss libsubid_zzz.so
test_nss: test_nss.c ../../../lib/nss.c
gcc -c -I../../../lib/ -I../../.. -o test_nss.o test_nss.c
gcc -o test_nss test_nss.o ../../../libmisc/.libs/libmisc.a ../../../lib/.libs/libshadow.a -ldl
libsubid_zzz.so: libsubid_zzz.c
gcc -c -I../../../lib/ -I../../.. -I../../../libmisc -I../../../libsubid libsubid_zzz.c
gcc -L../../../libsubid -shared -o libsubid_zzz.so libsubid_zzz.o ../../../lib/.libs/libshadow.a -ldl
clean:
rm -f *.o *.so test_nss

0
tests/libsubid/04_nss/empty Normal file
View File

146
tests/libsubid/04_nss/libsubid_zzz.c Normal file
View File

@ -0,0 +1,146 @@
#include <sys/types.h>
#include <pwd.h>
#include <stdlib.h>
#include <stdbool.h>
#include <subid.h>
#include <string.h>
enum subid_status shadow_subid_has_any_range(const char *owner, enum subid_type t, bool *result)
{
if (strcmp(owner, "ubuntu") == 0) {
*result = true;
return SUBID_STATUS_SUCCESS;
}
if (strcmp(owner, "error") == 0) {
*result = false;
return SUBID_STATUS_ERROR;
}
if (strcmp(owner, "unknown") == 0) {
*result = false;
return SUBID_STATUS_UNKNOWN_USER;
}
if (strcmp(owner, "conn") == 0) {
*result = false;
return SUBID_STATUS_ERROR_CONN;
}
if (t == ID_TYPE_UID) {
*result = strcmp(owner, "user1") == 0;
return SUBID_STATUS_SUCCESS;
}
*result = strcmp(owner, "group1") == 0;
return SUBID_STATUS_SUCCESS;
}
enum subid_status shadow_subid_has_range(const char *owner, unsigned long start, unsigned long count, enum subid_type t, bool *result)
{
if (strcmp(owner, "ubuntu") == 0 &&
start >= 200000 &&
count <= 100000) {
*result = true;
return SUBID_STATUS_SUCCESS;
}
*result = false;
if (strcmp(owner, "error") == 0)
return SUBID_STATUS_ERROR;
if (strcmp(owner, "unknown") == 0)
return SUBID_STATUS_UNKNOWN_USER;
if (strcmp(owner, "conn") == 0)
return SUBID_STATUS_ERROR_CONN;
if (t == ID_TYPE_UID && strcmp(owner, "user1") != 0)
return SUBID_STATUS_SUCCESS;
if (t == ID_TYPE_GID && strcmp(owner, "group1") != 0)
return SUBID_STATUS_SUCCESS;
if (start < 100000)
return SUBID_STATUS_SUCCESS;
if (count >= 65536)
return SUBID_STATUS_SUCCESS;
*result = true;
return SUBID_STATUS_SUCCESS;
}
// So if 'user1' or 'ubuntu' is defined in passwd, we'll return those values,
// to ease manual testing. For automated testing, if you return those values,
// we'll return 1000 for ubuntu and 1001 otherwise.
static uid_t getnamuid(const char *name) {
struct passwd *pw;
pw = getpwnam(name);
if (pw)
return pw->pw_uid;
// For testing purposes
return strcmp(name, "ubuntu") == 0 ? (uid_t)1000 : (uid_t)1001;
}
static int alloc_uid(uid_t **uids, uid_t id) {
*uids = malloc(sizeof(uid_t));
if (!*uids)
return -1;
*uids[0] = id;
return 1;
}
enum subid_status shadow_subid_find_subid_owners(unsigned long id, enum subid_type id_type, uid_t **uids, int *count)
{
if (id >= 100000 && id < 165536) {
*count = alloc_uid(uids, getnamuid("user1"));
if (*count == 1)
return SUBID_STATUS_SUCCESS;
return SUBID_STATUS_ERROR; // out of memory
}
if (id >= 200000 && id < 300000) {
*count = alloc_uid(uids, getnamuid("ubuntu"));
if (*count == 1)
return SUBID_STATUS_SUCCESS;
return SUBID_STATUS_ERROR; // out of memory
}
*count = 0; // nothing found
return SUBID_STATUS_SUCCESS;
}
enum subid_status shadow_subid_list_owner_ranges(const char *owner, enum subid_type id_type, struct subordinate_range ***in_ranges, int *count)
{
struct subordinate_range **ranges;
*count = 0;
if (strcmp(owner, "error") == 0)
return SUBID_STATUS_ERROR;
if (strcmp(owner, "unknown") == 0)
return SUBID_STATUS_UNKNOWN_USER;
if (strcmp(owner, "conn") == 0)
return SUBID_STATUS_ERROR_CONN;
*ranges = NULL;
if (strcmp(owner, "user1") != 0 && strcmp(owner, "ubuntu") != 0 &&
strcmp(owner, "group1") != 0)
return SUBID_STATUS_SUCCESS;
if (id_type == ID_TYPE_GID && strcmp(owner, "user1") == 0)
return SUBID_STATUS_SUCCESS;
if (id_type == ID_TYPE_UID && strcmp(owner, "group1") == 0)
return SUBID_STATUS_SUCCESS;
ranges = (struct subordinate_range **)malloc(sizeof(struct subordinate_range *));
if (!*ranges)
return SUBID_STATUS_ERROR;
ranges[0] = (struct subordinate_range *)malloc(sizeof(struct subordinate_range));
if (!ranges[0]) {
free(*ranges);
*ranges = NULL;
return SUBID_STATUS_ERROR;
}
ranges[0]->owner = strdup(owner);
if (strcmp(owner, "user1") == 0 || strcmp(owner, "group1") == 0) {
ranges[0]->start = 100000;
ranges[0]->count = 65536;
} else {
ranges[0]->start = 200000;
ranges[0]->count = 100000;
}
*count = 1;
*in_ranges = ranges;
return SUBID_STATUS_SUCCESS;
}

20
tests/libsubid/04_nss/nsswitch1.conf Normal file
View File

@ -0,0 +1,20 @@
# /etc/nsswitch.conf
#
# Example configuration of GNU Name Service Switch functionality.
# If you have the `glibc-doc-reference' and `info' packages installed, try:
# `info libc "Name Service Switch"' for information about this file.
passwd: files systemd
group: files systemd
shadow: files
gshadow: files
hosts: files mdns4_minimal [NOTFOUND=return] dns
networks: files
protocols: db files
services: db files
ethers: db files
rpc: db files
netgroup: nis

22
tests/libsubid/04_nss/nsswitch2.conf Normal file
View File

@ -0,0 +1,22 @@
# /etc/nsswitch.conf
#
# Example configuration of GNU Name Service Switch functionality.
# If you have the `glibc-doc-reference' and `info' packages installed, try:
# `info libc "Name Service Switch"' for information about this file.
passwd: files systemd
group: files systemd
shadow: files
gshadow: files
hosts: files mdns4_minimal [NOTFOUND=return] dns
networks: files
protocols: db files
services: db files
ethers: db files
rpc: db files
netgroup: nis
subid: files

22
tests/libsubid/04_nss/nsswitch3.conf Normal file
View File

@ -0,0 +1,22 @@
# /etc/nsswitch.conf
#
# Example configuration of GNU Name Service Switch functionality.
# If you have the `glibc-doc-reference' and `info' packages installed, try:
# `info libc "Name Service Switch"' for information about this file.
passwd: files systemd
group: files systemd
shadow: files
gshadow: files
hosts: files mdns4_minimal [NOTFOUND=return] dns
networks: files
protocols: db files
services: db files
ethers: db files
rpc: db files
netgroup: nis
subid: zzz

22
tests/libsubid/04_nss/subidnss.test Executable file
View File

@ -0,0 +1,22 @@
#!/bin/sh
set -e
cd $(dirname $0)
. ../../common/config.sh
. ../../common/log.sh
make
export LD_LIBRARY_PATH=.:../../../lib/.libs:$LD_LIBRARY_PATH
./test_nss 1
./test_nss 2
./test_nss 3
unshare -Urm ./test_range
log_status "$0" "SUCCESS"
trap '' 0

72
tests/libsubid/04_nss/test_nss.c Normal file
View File

@ -0,0 +1,72 @@
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <prototypes.h>
#include <stdbool.h>
#include <dlfcn.h>
extern bool nss_is_initialized();
extern struct subid_nss_ops *get_subid_nss_handle();
void test1() {
// nsswitch1 has no subid: entry
setenv("LD_LIBRARY_PATH", ".", 1);
printf("Test with no subid entry\n");
nss_init("./nsswitch1.conf");
if (!nss_is_initialized() || get_subid_nss_handle())
exit(1);
// second run should change nothing
printf("Test with no subid entry, second run\n");
nss_init("./nsswitch1.conf");
if (!nss_is_initialized() || get_subid_nss_handle())
exit(1);
}
void test2() {
// nsswitch2 has a subid: files entry
printf("test with 'files' subid entry\n");
nss_init("./nsswitch2.conf");
if (!nss_is_initialized() || get_subid_nss_handle())
exit(1);
// second run should change nothing
printf("test with 'files' subid entry, second run\n");
nss_init("./nsswitch2.conf");
if (!nss_is_initialized() || get_subid_nss_handle())
exit(1);
}
void test3() {
// nsswitch3 has a subid: testnss entry
printf("test with 'test' subid entry\n");
nss_init("./nsswitch3.conf");
if (!nss_is_initialized() || !get_subid_nss_handle())
exit(1);
// second run should change nothing
printf("test with 'test' subid entry, second run\n");
nss_init("./nsswitch3.conf");
if (!nss_is_initialized() || !get_subid_nss_handle())
exit(1);
}
const char *Prog;
int main(int argc, char *argv[])
{
int which;
Prog = Basename(argv[0]);
if (argc < 1)
exit(1);
which = atoi(argv[1]);
switch(which) {
case 1: test1(); break;
case 2: test2(); break;
case 3: test3(); break;
default: exit(1);
}
printf("nss parsing tests done\n");
exit(0);
}

50
tests/libsubid/04_nss/test_range Executable file
View File

@ -0,0 +1,50 @@
#!/bin/sh
set -x
echo "starting check_range tests"
export LD_LIBRARY_PATH=.:$LD_LIBRARY_PATH
mount --bind ./nsswitch3.conf /etc/nsswitch.conf
cleanup1() {
umount /etc/nsswitch.conf
}
trap cleanup1 EXIT HUP INT TERM
../../../src/check_subid_range user1 u 100000 65535
if [ $? -ne 0 ]; then
exit 1
fi
../../../src/check_subid_range user2 u 100000 65535
if [ $? -eq 0 ]; then
exit 1
fi
../../../src/check_subid_range unknown u 100000 65535
if [ $? -eq 0 ]; then
exit 1
fi
../../../src/check_subid_range error u 100000 65535
if [ $? -eq 0 ]; then
exit 1
fi
../../../src/check_subid_range user1 u 1000 65535
if [ $? -eq 0 ]; then
exit 1
fi
umount /etc/nsswitch.conf
mount --bind ./nsswitch1.conf /etc/nsswitch.conf
mount --bind ./empty /etc/subuid
cleanup2() {
umount /etc/subuid
umount /etc/nsswitch.conf
}
trap cleanup2 EXIT HUP INT TERM
../../../src/check_subid_range user1 u 100000 65535
if [ $? -eq 0 ]; then
exit 1
fi
echo "check_range tests complete"
exit 0

1
tests/run_some
View File

@ -127,6 +127,7 @@ run_test ./newuidmap/01_newuidmap/newuidmap.test
run_test ./newuidmap/02_newuidmap_relaxed_gid_check/newuidmap.test
run_test ./newgidmap/01_newgidmap/newgidmap.test
run_test ./newgidmap/02_newgidmap_relaxed_gid_check/newgidmap.test
run_test ./libsubid/04_nss/subidnss.test
echo
echo "$succeeded test(s) passed"