/*
* Copyright (C) Igor Sysoev
* Copyright (C) NGINX, Inc.
*/
#include <nxt_main.h>
static nxt_int_t nxt_credential_groups_get(nxt_task_t *task, nxt_mp_t *mp,
nxt_credential_t *uc);
nxt_int_t
nxt_credential_get(nxt_task_t *task, nxt_mp_t *mp, nxt_credential_t *uc,
const char *group)
{
struct group *grp;
struct passwd *pwd;
nxt_errno = 0;
pwd = getpwnam(uc->user);
if (nxt_slow_path(pwd == NULL)) {
if (nxt_errno == 0) {
nxt_alert(task, "getpwnam(\"%s\") failed, user \"%s\" not found",
uc->user, uc->user);
} else {
nxt_alert(task, "getpwnam(\"%s\") failed %E", uc->user, nxt_errno);
}
return NXT_ERROR;
}
uc->uid = pwd->pw_uid;
uc->base_gid = pwd->pw_gid;
if (group != NULL && group[0] != '\0') {
nxt_errno = 0;
grp = getgrnam(group);
if (nxt_slow_path(grp == NULL)) {
if (nxt_errno == 0) {
nxt_alert(task,
"getgrnam(\"%s\") failed, group \"%s\" not found",
group, group);
} else {
nxt_alert(task, "getgrnam(\"%s\") failed %E", group, nxt_errno);
}
return NXT_ERROR;
}
uc->base_gid = grp->gr_gid;
}
nxt_debug(task, "about to get \"%s\" groups (uid:%d, base gid:%d)",
uc->user, uc->uid, uc->base_gid);
if (nxt_credential_groups_get(task, mp, uc) != NXT_OK) {
return NXT_ERROR;
}
#if (NXT_DEBUG)
{
u_char *p, *end;
nxt_uint_t i;
u_char msg[NXT_MAX_ERROR_STR];
p = msg;
end = msg + NXT_MAX_ERROR_STR;
for (i = 0; i < uc->ngroups; i++) {
p = nxt_sprintf(p, end, "%d,", uc->gids[i]);
}
if (uc->ngroups > 0) {
p--;
}
nxt_debug(task, "user \"%s\" has gids:%*s", uc->user, p - msg, msg);
}
#endif
return NXT_OK;
}
#if (NXT_HAVE_GETGROUPLIST && !NXT_MACOSX)
#define NXT_NGROUPS nxt_min(256, NGROUPS_MAX)
static nxt_int_t
nxt_credential_groups_get(nxt_task_t *task, nxt_mp_t *mp,
nxt_credential_t *uc)
{
int ngroups;
gid_t groups[NXT_NGROUPS];
ngroups = NXT_NGROUPS;
if (getgrouplist(uc->user, uc->base_gid, groups, &ngroups) < 0) {
if (nxt_slow_path(ngroups <= NXT_NGROUPS)) {
nxt_alert(task, "getgrouplist(\"%s\", %d, ...) failed %E", uc->user,
uc->base_gid, nxt_errno);
return NXT_ERROR;
}
}
if (ngroups > NXT_NGROUPS) {
if (ngroups > NGROUPS_MAX) {
ngroups = NGROUPS_MAX;
}
uc->ngroups = ngroups;
uc->gids = nxt_mp_alloc(mp, ngroups * sizeof(gid_t));
if (nxt_slow_path(uc->gids == NULL)) {
return NXT_ERROR;
}
if (nxt_slow_path(getgrouplist(uc->user, uc->base_gid, uc->gids,
&ngroups) < 0)) {
nxt_alert(task, "getgrouplist(\"%s\", %d) failed %E", uc->user,
uc->base_gid, nxt_errno);
return NXT_ERROR;
}
return NXT_OK;
}
uc->ngroups = ngroups;
uc->gids = nxt_mp_alloc(mp, ngroups * sizeof(gid_t));
if (nxt_slow_path(uc->gids == NULL)) {
return NXT_ERROR;
}
nxt_memcpy(uc->gids, groups, ngroups * sizeof(gid_t));
return NXT_OK;
}
#else
/*
* For operating systems that lack getgrouplist(3) or it's buggy (MacOS),
* nxt_credential_groups_get() stores an array of groups IDs which should be
* set by the setgroups() function for a given user. The initgroups()
* may block a just forked worker process for some time if LDAP or NDIS+
* is used, so nxt_credential_groups_get() allows to get worker user groups in
* main process. In a nutshell the initgroups() calls getgrouplist()
* followed by setgroups(). However older Solaris lacks the getgrouplist().
* Besides getgrouplist() does not allow to query the exact number of
* groups in some platforms, while NGROUPS_MAX can be quite large (e.g.
* 65536 on Linux).
* So nxt_credential_groups_get() emulates getgrouplist(): at first the
* function saves the super-user groups IDs, then calls initgroups() and saves
* the specified user groups IDs, and then restores the super-user groups IDs.
* This works at least on Linux, FreeBSD, and Solaris, but does not work
* on MacOSX, getgroups(2):
*
* To provide compatibility with applications that use getgroups() in
* environments where users may be in more than {NGROUPS_MAX} groups,
* a variant of getgroups(), obtained when compiling with either the
* macros _DARWIN_UNLIMITED_GETGROUPS or _DARWIN_C_SOURCE defined, can
* be used that is not limited to {NGROUPS_MAX} groups. However, this
* variant only returns the user's default group access list and not
* the group list modified by a call to setgroups(2).
*
* For such cases initgroups() is used in worker process as fallback.
*/
static nxt_int_t
nxt_credential_groups_get(nxt_task_t *task, nxt_mp_t *mp, nxt_credential_t *uc)
{
int nsaved, ngroups;
nxt_int_t ret;
nxt_gid_t *saved;
nsaved = getgroups(0, NULL);
if (nxt_slow_path(nsaved == -1)) {
nxt_alert(task, "getgroups(0, NULL) failed %E", nxt_errno);
return NXT_ERROR;
}
nxt_debug(task, "getgroups(0, NULL): %d", nsaved);
if (nsaved > NGROUPS_MAX) {
/* MacOSX case. */
uc->gids = NULL;
uc->ngroups = 0;
return NXT_OK;
}
saved = nxt_mp_alloc(mp, nsaved * sizeof(nxt_gid_t));
if (nxt_slow_path(saved == NULL)) {
return NXT_ERROR;
}
ret = NXT_ERROR;
nsaved = getgroups(nsaved, saved);
if (nxt_slow_path(nsaved == -1)) {
nxt_alert(task, "getgroups(%d) failed %E", nsaved, nxt_errno);
goto free;
}
nxt_debug(task, "getgroups(): %d", nsaved);
if (initgroups(uc->user, uc->base_gid) != 0) {
if (nxt_errno == NXT_EPERM) {
nxt_log(task, NXT_LOG_NOTICE,
"initgroups(%s, %d) failed %E, ignored",
uc->user, uc->base_gid, nxt_errno);
ret = NXT_OK;
goto free;
} else {
nxt_alert(task, "initgroups(%s, %d) failed %E",
uc->user, uc->base_gid, nxt_errno);
goto restore;
}
}
ngroups = getgroups(0, NULL);
if (nxt_slow_path(ngroups == -1)) {
nxt_alert(task, "getgroups(0, NULL) failed %E", nxt_errno);
goto restore;
}
nxt_debug(task, "getgroups(0, NULL): %d", ngroups);
uc->gids = nxt_mp_alloc(mp, ngroups * sizeof(nxt_gid_t));
if (nxt_slow_path(uc->gids == NULL)) {
goto restore;
}
ngroups = getgroups(ngroups, uc->gids);
if (nxt_slow_path(ngroups == -1)) {
nxt_alert(task, "getgroups(%d) failed %E", ngroups, nxt_errno);
goto restore;
}
uc->ngroups = ngroups;
ret = NXT_OK;
restore:
if (nxt_slow_path(setgroups(nsaved, saved) != 0)) {
nxt_alert(task, "setgroups(%d) failed %E", nsaved, nxt_errno);
ret = NXT_ERROR;
}
free:
nxt_mp_free(mp, saved);
return ret;
}
#endif
nxt_int_t
nxt_credential_setuid(nxt_task_t *task, nxt_credential_t *uc)
{
nxt_debug(task, "user cred set: \"%s\" uid:%d", uc->user, uc->uid);
if (setuid(uc->uid) != 0) {
#if (NXT_HAVE_LINUX_NS)
if (nxt_errno == EINVAL) {
nxt_log(task, NXT_LOG_ERR, "The uid %d (user \"%s\") isn't "
"valid in the application namespace.", uc->uid, uc->user);
return NXT_ERROR;
}
#endif
nxt_alert(task, "setuid(%d) failed %E", uc->uid, nxt_errno);
return NXT_ERROR;
}
return NXT_OK;
}
nxt_int_t
nxt_credential_setgids(nxt_task_t *task, nxt_credential_t *uc)
{
nxt_runtime_t *rt;
nxt_debug(task, "user cred set gids: base gid:%d, ngroups: %d",
uc->base_gid, uc->ngroups);
rt = task->thread->runtime;
if (setgid(uc->base_gid) != 0) {
#if (NXT_HAVE_LINUX_NS)
if (nxt_errno == EINVAL) {
nxt_log(task, NXT_LOG_ERR, "The gid %d isn't valid in the "
"application namespace.", uc->base_gid);
return NXT_ERROR;
}
#endif
nxt_alert(task, "setgid(%d) failed %E", uc->base_gid, nxt_errno);
return NXT_ERROR;
}
if (!rt->capabilities.setid) {
return NXT_OK;
}
if (nxt_slow_path(uc->ngroups > 0
&& setgroups(uc->ngroups, uc->gids) != 0)) {
#if (NXT_HAVE_LINUX_NS)
if (nxt_errno == EINVAL) {
nxt_log(task, NXT_LOG_ERR, "The user \"%s\" (uid: %d) has "
"supplementary group ids not valid in the application "
"namespace.", uc->user, uc->uid);
return NXT_ERROR;
}
#endif
nxt_alert(task, "setgroups(%i) failed %E", uc->ngroups, nxt_errno);
return NXT_ERROR;
}
return NXT_OK;
}
