diff options
Diffstat (limited to 'src/nss-systemd/nss-systemd.c')
| -rw-r--r-- | src/nss-systemd/nss-systemd.c | 69 |
1 files changed, 40 insertions, 29 deletions
diff --git a/src/nss-systemd/nss-systemd.c b/src/nss-systemd/nss-systemd.c index e11f917c19..5dc5aacdff 100644 --- a/src/nss-systemd/nss-systemd.c +++ b/src/nss-systemd/nss-systemd.c @@ -8,6 +8,7 @@ #include "fd-util.h" #include "group-record-nss.h" #include "macro.h" +#include "nss-systemd.h" #include "nss-util.h" #include "pthread-util.h" #include "signal-util.h" @@ -299,7 +300,7 @@ enum nss_status _nss_systemd_setpwent(int stayopen) { PROTECT_ERRNO; BLOCK_SIGNALS(NSS_SIGNALS_BLOCK); - if (userdb_nss_compat_is_enabled() <= 0) + if (_nss_systemd_is_blocked()) return NSS_STATUS_NOTFOUND; _cleanup_(pthread_mutex_unlock_assertp) pthread_mutex_t *_l = NULL; @@ -323,7 +324,7 @@ enum nss_status _nss_systemd_setgrent(int stayopen) { PROTECT_ERRNO; BLOCK_SIGNALS(NSS_SIGNALS_BLOCK); - if (userdb_nss_compat_is_enabled() <= 0) + if (_nss_systemd_is_blocked()) return NSS_STATUS_NOTFOUND; _cleanup_(pthread_mutex_unlock_assertp) pthread_mutex_t *_l = NULL; @@ -353,13 +354,7 @@ enum nss_status _nss_systemd_getpwent_r( assert(result); assert(errnop); - r = userdb_nss_compat_is_enabled(); - if (r < 0) { - UNPROTECT_ERRNO; - *errnop = -r; - return NSS_STATUS_UNAVAIL; - } - if (!r) + if (_nss_systemd_is_blocked()) return NSS_STATUS_NOTFOUND; _cleanup_(pthread_mutex_unlock_assertp) pthread_mutex_t *_l = NULL; @@ -406,14 +401,8 @@ enum nss_status _nss_systemd_getgrent_r( assert(result); assert(errnop); - r = userdb_nss_compat_is_enabled(); - if (r < 0) { - UNPROTECT_ERRNO; - *errnop = -r; - return NSS_STATUS_UNAVAIL; - } - if (!r) - return NSS_STATUS_UNAVAIL; + if (_nss_systemd_is_blocked()) + return NSS_STATUS_NOTFOUND; _cleanup_(pthread_mutex_unlock_assertp) pthread_mutex_t *_l = NULL; @@ -459,7 +448,7 @@ enum nss_status _nss_systemd_getgrent_r( } if (getgrent_data.by_membership) { - _cleanup_close_ int lock_fd = -1; + _cleanup_(_nss_systemd_unblockp) bool blocked = false; for (;;) { _cleanup_free_ char *user_name = NULL, *group_name = NULL; @@ -479,13 +468,15 @@ enum nss_status _nss_systemd_getgrent_r( continue; /* We are about to recursively call into NSS, let's make sure we disable recursion into our own code. */ - if (lock_fd < 0) { - lock_fd = userdb_nss_compat_disable(); - if (lock_fd < 0 && lock_fd != -EBUSY) { + if (!blocked) { + r = _nss_systemd_block(true); + if (r < 0) { UNPROTECT_ERRNO; - *errnop = -lock_fd; + *errnop = -r; return NSS_STATUS_UNAVAIL; } + + blocked = true; } r = nss_group_record_by_name(group_name, false, &gr); @@ -549,13 +540,7 @@ enum nss_status _nss_systemd_initgroups_dyn( if (STR_IN_SET(user_name, root_passwd.pw_name, nobody_passwd.pw_name)) return NSS_STATUS_NOTFOUND; - r = userdb_nss_compat_is_enabled(); - if (r < 0) { - UNPROTECT_ERRNO; - *errnop = -r; - return NSS_STATUS_UNAVAIL; - } - if (!r) + if (_nss_systemd_is_blocked()) return NSS_STATUS_NOTFOUND; r = membershipdb_by_user(user_name, nss_glue_userdb_flags(), &iterator); @@ -627,3 +612,29 @@ enum nss_status _nss_systemd_initgroups_dyn( return any ? NSS_STATUS_SUCCESS : NSS_STATUS_NOTFOUND; } + +static thread_local unsigned _blocked = 0; + +_public_ int _nss_systemd_block(bool b) { + + /* This blocks recursively: it's blocked for as many times this function is called with `true` until + * it is called an equal time with `false`. */ + + if (b) { + if (_blocked >= UINT_MAX) + return -EOVERFLOW; + + _blocked++; + } else { + if (_blocked <= 0) + return -EOVERFLOW; + + _blocked--; + } + + return b; /* Return what is passed in, i.e. the new state from the PoV of the caller */ +} + +_public_ bool _nss_systemd_is_blocked(void) { + return _blocked > 0; +} |