s3:dom_sid Global replace of DOM_SID with struct dom_sid
[kamenim/samba-autobuild/.git] / source3 / passdb / lookup_sid.c
index 4e11bb84d873490200175aa10c9843da4e2b760f..181b17a8381bc6bd57048c22422a30cc857fd296 100644 (file)
 bool lookup_name(TALLOC_CTX *mem_ctx,
                 const char *full_name, int flags,
                 const char **ret_domain, const char **ret_name,
-                DOM_SID *ret_sid, enum lsa_SidType *ret_type)
+                struct dom_sid *ret_sid, enum lsa_SidType *ret_type)
 {
        char *p;
        const char *tmp;
        const char *domain = NULL;
        const char *name = NULL;
        uint32 rid;
-       DOM_SID sid;
+       struct dom_sid sid;
        enum lsa_SidType type;
        TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 
@@ -65,7 +65,7 @@ bool lookup_name(TALLOC_CTX *mem_ctx,
                return false;
        }
 
-       DEBUG(10,("lookup_name: %s => %s (domain), %s (name)\n",
+       DEBUG(10,("lookup_name: %s => domain=[%s], name=[%s]\n",
                full_name, domain, name));
        DEBUG(10, ("lookup_name: flags = 0x0%x\n", flags));
 
@@ -75,8 +75,7 @@ bool lookup_name(TALLOC_CTX *mem_ctx,
 
                /* It's our own domain, lookup the name in passdb */
                if (lookup_global_sam_name(name, flags, &rid, &type)) {
-                       sid_copy(&sid, get_global_sam_sid());
-                       sid_append_rid(&sid, rid);
+                       sid_compose(&sid, get_global_sam_sid(), rid);
                        goto ok;
                }
                TALLOC_FREE(tmp_ctx);
@@ -86,10 +85,17 @@ bool lookup_name(TALLOC_CTX *mem_ctx,
        if ((flags & LOOKUP_NAME_BUILTIN) &&
            strequal(domain, builtin_domain_name()))
        {
+               if (strlen(name) == 0) {
+                       /* Swap domain and name */
+                       tmp = name; name = domain; domain = tmp;
+                       sid_copy(&sid, &global_sid_Builtin);
+                       type = SID_NAME_DOMAIN;
+                       goto ok;
+               }
+
                /* Explicit request for a name in BUILTIN */
                if (lookup_builtin_name(name, &rid)) {
-                       sid_copy(&sid, &global_sid_Builtin);
-                       sid_append_rid(&sid, rid);
+                       sid_compose(&sid, &global_sid_Builtin, rid);
                        type = SID_NAME_ALIAS;
                        goto ok;
                }
@@ -106,7 +112,8 @@ bool lookup_name(TALLOC_CTX *mem_ctx,
                        goto ok;
        }
 
-       if (!(flags & LOOKUP_NAME_EXPLICIT) && strequal(domain, unix_users_domain_name())) {
+       if (((flags & LOOKUP_NAME_NO_NSS) == 0)
+           && strequal(domain, unix_users_domain_name())) {
                if (lookup_unix_user_name(name, &sid)) {
                        type = SID_NAME_USER;
                        goto ok;
@@ -115,7 +122,8 @@ bool lookup_name(TALLOC_CTX *mem_ctx,
                return false;
        }
 
-       if (!(flags & LOOKUP_NAME_EXPLICIT) && strequal(domain, unix_groups_domain_name())) {
+       if (((flags & LOOKUP_NAME_NO_NSS) == 0)
+           && strequal(domain, unix_groups_domain_name())) {
                if (lookup_unix_group_name(name, &sid)) {
                        type = SID_NAME_DOM_GRP;
                        goto ok;
@@ -205,8 +213,7 @@ bool lookup_name(TALLOC_CTX *mem_ctx,
            lookup_builtin_name(name, &rid))
        {
                domain = talloc_strdup(tmp_ctx, builtin_domain_name());
-               sid_copy(&sid, &global_sid_Builtin);
-               sid_append_rid(&sid, rid);
+               sid_compose(&sid, &global_sid_Builtin, rid);
                type = SID_NAME_ALIAS;
                goto ok;
        }
@@ -220,8 +227,7 @@ bool lookup_name(TALLOC_CTX *mem_ctx,
            lookup_global_sam_name(name, flags, &rid, &type))
        {
                domain = talloc_strdup(tmp_ctx, get_global_sam_name());
-               sid_copy(&sid, get_global_sam_sid());
-               sid_append_rid(&sid, rid);
+               sid_compose(&sid, get_global_sam_sid(), rid);
                goto ok;
        }
 
@@ -247,7 +253,7 @@ bool lookup_name(TALLOC_CTX *mem_ctx,
         * that (yet), but give it a chance. */
 
        if (IS_DC && winbind_lookup_name("", name, &sid, &type)) {
-               DOM_SID dom_sid;
+               struct dom_sid dom_sid;
                uint32 tmp_rid;
                enum lsa_SidType domain_type;
                
@@ -280,13 +286,15 @@ bool lookup_name(TALLOC_CTX *mem_ctx,
        /* 11. Ok, windows would end here. Samba has two more options:
                Unmapped users and unmapped groups */
 
-       if (!(flags & LOOKUP_NAME_EXPLICIT) && lookup_unix_user_name(name, &sid)) {
+       if (((flags & LOOKUP_NAME_NO_NSS) == 0)
+           && lookup_unix_user_name(name, &sid)) {
                domain = talloc_strdup(tmp_ctx, unix_users_domain_name());
                type = SID_NAME_USER;
                goto ok;
        }
 
-       if (!(flags & LOOKUP_NAME_EXPLICIT) && lookup_unix_group_name(name, &sid)) {
+       if (((flags & LOOKUP_NAME_NO_NSS) == 0)
+           && lookup_unix_group_name(name, &sid)) {
                domain = talloc_strdup(tmp_ctx, unix_groups_domain_name());
                type = SID_NAME_DOM_GRP;
                goto ok;
@@ -349,7 +357,7 @@ bool lookup_name(TALLOC_CTX *mem_ctx,
 bool lookup_name_smbconf(TALLOC_CTX *mem_ctx,
                 const char *full_name, int flags,
                 const char **ret_domain, const char **ret_name,
-                DOM_SID *ret_sid, enum lsa_SidType *ret_type)
+                struct dom_sid *ret_sid, enum lsa_SidType *ret_type)
 {
        char *qualified_name;
        const char *p;
@@ -407,7 +415,7 @@ bool lookup_name_smbconf(TALLOC_CTX *mem_ctx,
 }
 
 static bool wb_lookup_rids(TALLOC_CTX *mem_ctx,
-                          const DOM_SID *domain_sid,
+                          const struct dom_sid *domain_sid,
                           int num_rids, uint32 *rids,
                           const char **domain_name,
                           const char **names, enum lsa_SidType *types)
@@ -457,7 +465,7 @@ static bool wb_lookup_rids(TALLOC_CTX *mem_ctx,
        return true;
 }
 
-static bool lookup_rids(TALLOC_CTX *mem_ctx, const DOM_SID *domain_sid,
+static bool lookup_rids(TALLOC_CTX *mem_ctx, const struct dom_sid *domain_sid,
                        int num_rids, uint32_t *rids,
                        const char **domain_name,
                        const char ***names, enum lsa_SidType **types)
@@ -468,12 +476,15 @@ static bool lookup_rids(TALLOC_CTX *mem_ctx, const DOM_SID *domain_sid,
                   sid_string_dbg(domain_sid)));
 
        if (num_rids) {
-               *names = TALLOC_ARRAY(mem_ctx, const char *, num_rids);
+               *names = TALLOC_ZERO_ARRAY(mem_ctx, const char *, num_rids);
                *types = TALLOC_ARRAY(mem_ctx, enum lsa_SidType, num_rids);
 
                if ((*names == NULL) || (*types == NULL)) {
                        return false;
                }
+
+               for (i = 0; i < num_rids; i++)
+                       (*types)[i] = SID_NAME_UNKNOWN;
        } else {
                *names = NULL;
                *types = NULL;
@@ -528,9 +539,8 @@ static bool lookup_rids(TALLOC_CTX *mem_ctx, const DOM_SID *domain_sid,
 
        if (sid_check_is_wellknown_domain(domain_sid, NULL)) {
                for (i=0; i<num_rids; i++) {
-                       DOM_SID sid;
-                       sid_copy(&sid, domain_sid);
-                       sid_append_rid(&sid, rids[i]);
+                       struct dom_sid sid;
+                       sid_compose(&sid, domain_sid, rids[i]);
                        if (lookup_wellknown_sid(mem_ctx, &sid,
                                                 domain_name, &(*names)[i])) {
                                if ((*names)[i] == NULL) {
@@ -590,7 +600,7 @@ static bool lookup_rids(TALLOC_CTX *mem_ctx, const DOM_SID *domain_sid,
  * Is the SID a domain as such? If yes, lookup its name.
  */
 
-static bool lookup_as_domain(const DOM_SID *sid, TALLOC_CTX *mem_ctx,
+static bool lookup_as_domain(const struct dom_sid *sid, TALLOC_CTX *mem_ctx,
                             const char **name)
 {
        const char *tmp;
@@ -678,7 +688,7 @@ static bool lookup_as_domain(const DOM_SID *sid, TALLOC_CTX *mem_ctx,
  * Level 6: Like 4
  */
 
-static bool check_dom_sid_to_level(const DOM_SID *sid, int level)
+static bool check_dom_sid_to_level(const struct dom_sid *sid, int level)
 {
        int ret = false;
 
@@ -719,7 +729,7 @@ static bool check_dom_sid_to_level(const DOM_SID *sid, int level)
  */
 
 NTSTATUS lookup_sids(TALLOC_CTX *mem_ctx, int num_sids,
-                    const DOM_SID **sids, int level,
+                    const struct dom_sid **sids, int level,
                     struct lsa_dom_info **ret_domains,
                     struct lsa_name_info **ret_names)
 {
@@ -746,7 +756,7 @@ NTSTATUS lookup_sids(TALLOC_CTX *mem_ctx, int num_sids,
        }
 
        dom_infos = TALLOC_ZERO_ARRAY(mem_ctx, struct lsa_dom_info,
-                                     MAX_REF_DOMAINS);
+                                     LSA_REF_DOMAIN_LIST_MULTIPLIER);
        if (dom_infos == NULL) {
                result = NT_STATUS_NO_MEMORY;
                goto fail;
@@ -767,7 +777,7 @@ NTSTATUS lookup_sids(TALLOC_CTX *mem_ctx, int num_sids,
         */
 
        for (i=0; i<num_sids; i++) {
-               DOM_SID sid;
+               struct dom_sid sid;
                uint32 rid;
                const char *domain_name = NULL;
 
@@ -804,7 +814,7 @@ NTSTATUS lookup_sids(TALLOC_CTX *mem_ctx, int num_sids,
                } else {
                        /* This is a normal SID with rid component */
                        if (!sid_split_rid(&sid, &rid)) {
-                               result = NT_STATUS_INVALID_PARAMETER;
+                               result = NT_STATUS_INVALID_SID;
                                goto fail;
                        }
                }
@@ -816,7 +826,7 @@ NTSTATUS lookup_sids(TALLOC_CTX *mem_ctx, int num_sids,
                        continue;
                }
 
-               for (j=0; j<MAX_REF_DOMAINS; j++) {
+               for (j=0; j<LSA_REF_DOMAIN_LIST_MULTIPLIER; j++) {
                        if (!dom_infos[j].valid) {
                                break;
                        }
@@ -825,7 +835,7 @@ NTSTATUS lookup_sids(TALLOC_CTX *mem_ctx, int num_sids,
                        }
                }
 
-               if (j == MAX_REF_DOMAINS) {
+               if (j == LSA_REF_DOMAIN_LIST_MULTIPLIER) {
                        /* TODO: What's the right error message here? */
                        result = NT_STATUS_NONE_MAPPED;
                        goto fail;
@@ -869,7 +879,7 @@ NTSTATUS lookup_sids(TALLOC_CTX *mem_ctx, int num_sids,
 
        /* Iterate over the domains found */
 
-       for (i=0; i<MAX_REF_DOMAINS; i++) {
+       for (i=0; i<LSA_REF_DOMAIN_LIST_MULTIPLIER; i++) {
                uint32_t *rids;
                const char *domain_name = NULL;
                const char **names;
@@ -938,7 +948,7 @@ NTSTATUS lookup_sids(TALLOC_CTX *mem_ctx, int num_sids,
  *THE CANONICAL* convert SID to name function.
 *****************************************************************/  
 
-bool lookup_sid(TALLOC_CTX *mem_ctx, const DOM_SID *sid,
+bool lookup_sid(TALLOC_CTX *mem_ctx, const struct dom_sid *sid,
                const char **ret_domain, const char **ret_name,
                enum lsa_SidType *ret_type)
 {
@@ -1002,7 +1012,7 @@ bool lookup_sid(TALLOC_CTX *mem_ctx, const DOM_SID *sid,
   Find a SID given a uid.
 *****************************************************************/
 
-static bool fetch_sid_from_uid_cache(DOM_SID *psid, uid_t uid)
+static bool fetch_sid_from_uid_cache(struct dom_sid *psid, uid_t uid)
 {
        DATA_BLOB cache_value;
 
@@ -1023,7 +1033,7 @@ static bool fetch_sid_from_uid_cache(DOM_SID *psid, uid_t uid)
   Find a uid given a SID.
 *****************************************************************/
 
-static bool fetch_uid_from_cache( uid_t *puid, const DOM_SID *psid )
+static bool fetch_uid_from_cache( uid_t *puid, const struct dom_sid *psid )
 {
        DATA_BLOB cache_value;
 
@@ -1043,7 +1053,7 @@ static bool fetch_uid_from_cache( uid_t *puid, const DOM_SID *psid )
  Store uid to SID mapping in cache.
 *****************************************************************/
 
-void store_uid_sid_cache(const DOM_SID *psid, uid_t uid)
+void store_uid_sid_cache(const struct dom_sid *psid, uid_t uid)
 {
        memcache_add(NULL, SID_UID_CACHE,
                     data_blob_const(psid, ndr_size_dom_sid(psid, 0)),
@@ -1057,7 +1067,7 @@ void store_uid_sid_cache(const DOM_SID *psid, uid_t uid)
   Find a SID given a gid.
 *****************************************************************/
 
-static bool fetch_sid_from_gid_cache(DOM_SID *psid, gid_t gid)
+static bool fetch_sid_from_gid_cache(struct dom_sid *psid, gid_t gid)
 {
        DATA_BLOB cache_value;
 
@@ -1078,11 +1088,11 @@ static bool fetch_sid_from_gid_cache(DOM_SID *psid, gid_t gid)
   Find a gid given a SID.
 *****************************************************************/
 
-static bool fetch_gid_from_cache(gid_t *pgid, const DOM_SID *psid)
+static bool fetch_gid_from_cache(gid_t *pgid, const struct dom_sid *psid)
 {
        DATA_BLOB cache_value;
 
-       if (!memcache_lookup(NULL, SID_UID_CACHE,
+       if (!memcache_lookup(NULL, SID_GID_CACHE,
                             data_blob_const(psid, ndr_size_dom_sid(psid, 0)),
                             &cache_value)) {
                return false;
@@ -1098,7 +1108,7 @@ static bool fetch_gid_from_cache(gid_t *pgid, const DOM_SID *psid)
  Store gid to SID mapping in cache.
 *****************************************************************/
 
-void store_gid_sid_cache(const DOM_SID *psid, gid_t gid)
+void store_gid_sid_cache(const struct dom_sid *psid, gid_t gid)
 {
        memcache_add(NULL, SID_GID_CACHE,
                     data_blob_const(psid, ndr_size_dom_sid(psid, 0)),
@@ -1109,24 +1119,21 @@ void store_gid_sid_cache(const DOM_SID *psid, gid_t gid)
 }
 
 /*****************************************************************
- uid_t->SID conversion used if winbind is not around
+ *THE LEGACY* convert uid_t to SID function.
 *****************************************************************/  
 
-static void legacy_uid_to_sid(DOM_SID *psid, uid_t uid)
+static void legacy_uid_to_sid(struct dom_sid *psid, uid_t uid)
 {
-       uint32 rid;
        bool ret;
 
        ZERO_STRUCTP(psid);
 
        become_root();
-       ret = pdb_uid_to_rid(uid, &rid);
+       ret = pdb_uid_to_sid(uid, psid);
        unbecome_root();
 
        if (ret) {
                /* This is a mapped user */
-               sid_copy(psid, get_global_sam_sid());
-               sid_append_rid(psid, rid);
                goto done;
        }
 
@@ -1143,10 +1150,10 @@ static void legacy_uid_to_sid(DOM_SID *psid, uid_t uid)
 }
 
 /*****************************************************************
- gid_t->SID conversion used if winbind is not around
+ *THE LEGACY* convert gid_t to SID function.
 *****************************************************************/  
 
-static void legacy_gid_to_sid(DOM_SID *psid, gid_t gid)
+static void legacy_gid_to_sid(struct dom_sid *psid, gid_t gid)
 {
        bool ret;
 
@@ -1174,15 +1181,14 @@ static void legacy_gid_to_sid(DOM_SID *psid, gid_t gid)
 }
 
 /*****************************************************************
- SID->uid_t conversion used if winbind is not around
+ *THE LEGACY* convert SID to uid function.
 *****************************************************************/  
 
-static bool legacy_sid_to_uid(const DOM_SID *psid, uid_t *puid)
+static bool legacy_sid_to_uid(const struct dom_sid *psid, uid_t *puid)
 {
        enum lsa_SidType type;
-       uint32 rid;
 
-       if (sid_peek_check_rid(get_global_sam_sid(), psid, &rid)) {
+       if (sid_check_is_in_our_domain(psid)) {
                union unid_t id;
                bool ret;
 
@@ -1217,12 +1223,12 @@ done:
 }
 
 /*****************************************************************
- SID->gid_t conversion used if winbind is not around
+ *THE LEGACY* convert SID to gid function.
+ Group mapping is used for gids that maps to Wellknown SIDs
 *****************************************************************/  
 
-static bool legacy_sid_to_gid(const DOM_SID *psid, gid_t *pgid)
+static bool legacy_sid_to_gid(const struct dom_sid *psid, gid_t *pgid)
 {
-       uint32 rid;
        GROUP_MAP map;
        union unid_t id;
        enum lsa_SidType type;
@@ -1244,7 +1250,7 @@ static bool legacy_sid_to_gid(const DOM_SID *psid, gid_t *pgid)
                return false;
        }
 
-       if (sid_peek_check_rid(get_global_sam_sid(), psid, &rid)) {
+       if (sid_check_is_in_our_domain(psid)) {
                bool ret;
 
                become_root();
@@ -1280,25 +1286,49 @@ static bool legacy_sid_to_gid(const DOM_SID *psid, gid_t *pgid)
 }
 
 /*****************************************************************
- uid_t->SID conversion
+ *THE CANONICAL* convert uid_t to SID function.
 *****************************************************************/  
 
-void uid_to_sid(DOM_SID *psid, uid_t uid)
+void uid_to_sid(struct dom_sid *psid, uid_t uid)
 {
+       bool expired = true;
+       bool ret;
        ZERO_STRUCTP(psid);
 
        if (fetch_sid_from_uid_cache(psid, uid))
                return;
 
-       if (!winbind_uid_to_sid(psid, uid)) {
-               if (!winbind_ping()) {
+       /* Check the winbindd cache directly. */
+       ret = idmap_cache_find_uid2sid(uid, psid, &expired);
+
+       if (ret && !expired && is_null_sid(psid)) {
+               /*
+                * Negative cache entry, we already asked.
+                * do legacy.
+                */
+               legacy_uid_to_sid(psid, uid);
+               return;
+       }
+
+       if (!ret || expired) {
+               /* Not in cache. Ask winbindd. */
+               if (!winbind_uid_to_sid(psid, uid)) {
+                       /*
+                        * We shouldn't return the NULL SID
+                        * here if winbind was running and
+                        * couldn't map, as winbind will have
+                        * added a negative entry that will
+                        * cause us to go though the
+                        * legacy_uid_to_sid()
+                        * function anyway in the case above
+                        * the next time we ask.
+                        */
+                       DEBUG(5, ("uid_to_sid: winbind failed to find a sid "
+                                 "for uid %u\n", (unsigned int)uid));
+
                        legacy_uid_to_sid(psid, uid);
                        return;
                }
-
-               DEBUG(5, ("uid_to_sid: winbind failed to find a sid for uid %u\n",
-                       uid));
-               return;
        }
 
        DEBUG(10,("uid %u -> sid %s\n", (unsigned int)uid,
@@ -1309,40 +1339,67 @@ void uid_to_sid(DOM_SID *psid, uid_t uid)
 }
 
 /*****************************************************************
- gid_t->SID conversion
+ *THE CANONICAL* convert gid_t to SID function.
 *****************************************************************/  
 
-void gid_to_sid(DOM_SID *psid, gid_t gid)
+void gid_to_sid(struct dom_sid *psid, gid_t gid)
 {
+       bool expired = true;
+       bool ret;
        ZERO_STRUCTP(psid);
 
        if (fetch_sid_from_gid_cache(psid, gid))
                return;
 
-       if (!winbind_gid_to_sid(psid, gid)) {
-               if (!winbind_ping()) {
+       /* Check the winbindd cache directly. */
+       ret = idmap_cache_find_gid2sid(gid, psid, &expired);
+
+       if (ret && !expired && is_null_sid(psid)) {
+               /*
+                * Negative cache entry, we already asked.
+                * do legacy.
+                */
+               legacy_gid_to_sid(psid, gid);
+               return;
+       }
+
+       if (!ret || expired) {
+               /* Not in cache. Ask winbindd. */
+               if (!winbind_gid_to_sid(psid, gid)) {
+                       /*
+                        * We shouldn't return the NULL SID
+                        * here if winbind was running and
+                        * couldn't map, as winbind will have
+                        * added a negative entry that will
+                        * cause us to go though the
+                        * legacy_gid_to_sid()
+                        * function anyway in the case above
+                        * the next time we ask.
+                        */
+                       DEBUG(5, ("gid_to_sid: winbind failed to find a sid "
+                                 "for gid %u\n", (unsigned int)gid));
+
                        legacy_gid_to_sid(psid, gid);
                        return;
                }
-
-               DEBUG(5, ("gid_to_sid: winbind failed to find a sid for gid %u\n",
-                       gid));
-               return;
        }
 
        DEBUG(10,("gid %u -> sid %s\n", (unsigned int)gid,
                  sid_string_dbg(psid)));
-       
+
        store_gid_sid_cache(psid, gid);
        return;
 }
 
 /*****************************************************************
- SID->uid_t conversion
+ *THE CANONICAL* convert SID to uid function.
 *****************************************************************/  
 
-bool sid_to_uid(const DOM_SID *psid, uid_t *puid)
+bool sid_to_uid(const struct dom_sid *psid, uid_t *puid)
 {
+       bool expired = true;
+       bool ret;
+       uint32 rid;
        gid_t gid;
 
        if (fetch_uid_from_cache(puid, psid))
@@ -1354,27 +1411,35 @@ bool sid_to_uid(const DOM_SID *psid, uid_t *puid)
 
        /* Optimize for the Unix Users Domain
         * as the conversion is straightforward */
-
-       if (sid_check_is_in_unix_users(psid)) {
-               uint32_t rid;
-
-               sid_peek_rid(psid, &rid);
-               *puid = (uid_t)rid;
+       if (sid_peek_check_rid(&global_sid_Unix_Users, psid, &rid)) {
+               uid_t uid = rid;
+               *puid = uid;
 
                /* return here, don't cache */
-               DEBUG(10, ("sid %s -> uid %u\n", sid_string_dbg(psid),
-                          (unsigned int)rid));
+               DEBUG(10,("sid %s -> uid %u\n", sid_string_dbg(psid),
+                       (unsigned int)*puid ));
                return true;
        }
 
-       if (!winbind_sid_to_uid(puid, psid)) {
-               if (!winbind_ping()) {
+       /* Check the winbindd cache directly. */
+       ret = idmap_cache_find_sid2uid(psid, puid, &expired);
+
+       if (ret && !expired && (*puid == (uid_t)-1)) {
+               /*
+                * Negative cache entry, we already asked.
+                * do legacy.
+                */
+               return legacy_sid_to_uid(psid, puid);
+       }
+
+       if (!ret || expired) {
+               /* Not in cache. Ask winbindd. */
+               if (!winbind_sid_to_uid(puid, psid)) {
+                       DEBUG(5, ("winbind failed to find a uid for sid %s\n",
+                                 sid_string_dbg(psid)));
+                       /* winbind failed. do legacy */
                        return legacy_sid_to_uid(psid, puid);
                }
-
-               DEBUG(5, ("winbind failed to find a uid for sid %s\n",
-                         sid_string_dbg(psid)));
-               return false;
        }
 
        /* TODO: Here would be the place to allocate both a gid and a uid for
@@ -1388,11 +1453,14 @@ bool sid_to_uid(const DOM_SID *psid, uid_t *puid)
 }
 
 /*****************************************************************
- SID->gid_t conversion
+ *THE CANONICAL* convert SID to gid function.
+ Group mapping is used for gids that maps to Wellknown SIDs
 *****************************************************************/  
 
-bool sid_to_gid(const DOM_SID *psid, gid_t *pgid)
+bool sid_to_gid(const struct dom_sid *psid, gid_t *pgid)
 {
+       bool expired = true;
+       bool ret;
        uint32 rid;
        uid_t uid;
 
@@ -1404,37 +1472,44 @@ bool sid_to_gid(const DOM_SID *psid, gid_t *pgid)
 
        /* Optimize for the Unix Groups Domain
         * as the conversion is straightforward */
-
-       if (sid_check_is_in_unix_groups(psid)) {
-               uint32_t rid;
-
-               sid_peek_rid(psid, &rid);
-               *pgid = (gid_t)rid;
+       if (sid_peek_check_rid(&global_sid_Unix_Groups, psid, &rid)) {
+               gid_t gid = rid;
+               *pgid = gid;
 
                /* return here, don't cache */
-               DEBUG(10, ("sid %s -> gid %u\n", sid_string_dbg(psid),
-                          (unsigned int)rid));
+               DEBUG(10,("sid %s -> gid %u\n", sid_string_dbg(psid),
+                       (unsigned int)*pgid ));
                return true;
        }
 
-       /* Ask winbindd if it can map this sid to a gid.
-        * (Idmap will check it is a valid SID and of the right type) */
+       /* Check the winbindd cache directly. */
+       ret = idmap_cache_find_sid2gid(psid, pgid, &expired);
+
+       if (ret && !expired && (*pgid == (gid_t)-1)) {
+               /*
+                * Negative cache entry, we already asked.
+                * do legacy.
+                */
+               return legacy_sid_to_gid(psid, pgid);
+       }
+
+       if (!ret || expired) {
+               /* Not in cache or negative. Ask winbindd. */
+               /* Ask winbindd if it can map this sid to a gid.
+                * (Idmap will check it is a valid SID and of the right type) */
 
-       if ( !winbind_sid_to_gid(pgid, psid) ) {
-               if (!winbind_ping()) {
+               if ( !winbind_sid_to_gid(pgid, psid) ) {
+
+                       DEBUG(10,("winbind failed to find a gid for sid %s\n",
+                                 sid_string_dbg(psid)));
+                       /* winbind failed. do legacy */
                        return legacy_sid_to_gid(psid, pgid);
                }
-
-               DEBUG(10,("winbind failed to find a gid for sid %s\n",
-                         sid_string_dbg(psid)));
-               return false;
        }
 
        DEBUG(10,("sid %s -> gid %u\n", sid_string_dbg(psid),
                  (unsigned int)*pgid ));
 
        store_gid_sid_cache(psid, *pgid);
-       
        return true;
 }
-