s3-lsa: allow to lookup BUILTIN\ in lsa_LookupNames.
[ira/wip.git] / source3 / passdb / lookup_sid.c
index dbc0e75e595c845c074d9e338a5411843f47f1c0..1fcd94c059dd22204a6363bfcccb472a5880d55f 100644 (file)
@@ -7,7 +7,7 @@
    
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2 of the License, or
+   the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.
    
    This program is distributed in the hope that it will be useful,
@@ -16,8 +16,7 @@
    GNU General Public License for more details.
    
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 #include "includes.h"
@@ -30,7 +29,7 @@
  to do guesswork.
 *****************************************************************/  
 
-BOOL lookup_name(TALLOC_CTX *mem_ctx,
+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)
@@ -46,7 +45,7 @@ BOOL lookup_name(TALLOC_CTX *mem_ctx,
 
        if (tmp_ctx == NULL) {
                DEBUG(0, ("talloc_new failed\n"));
-               return False;
+               return false;
        }
 
        p = strchr_m(full_name, '\\');
@@ -60,16 +59,19 @@ BOOL lookup_name(TALLOC_CTX *mem_ctx,
                name = talloc_strdup(tmp_ctx, full_name);
        }
 
-       DEBUG(10,("lookup_name: %s => %s (domain), %s (name)\n", 
-               full_name, domain, name));
-
        if ((domain == NULL) || (name == NULL)) {
                DEBUG(0, ("talloc failed\n"));
                TALLOC_FREE(tmp_ctx);
-               return False;
+               return false;
        }
 
-       if (strequal(domain, get_global_sam_name())) {
+       DEBUG(10,("lookup_name: %s => %s (domain), %s (name)\n",
+               full_name, domain, name));
+       DEBUG(10, ("lookup_name: flags = 0x0%x\n", flags));
+
+       if ((flags & LOOKUP_NAME_DOMAIN) &&
+           strequal(domain, get_global_sam_name()))
+       {
 
                /* It's our own domain, lookup the name in passdb */
                if (lookup_global_sam_name(name, flags, &rid, &type)) {
@@ -78,10 +80,19 @@ BOOL lookup_name(TALLOC_CTX *mem_ctx,
                        goto ok;
                }
                TALLOC_FREE(tmp_ctx);
-               return False;
+               return false;
        }
 
-       if (strequal(domain, builtin_domain_name())) {
+       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)) {
@@ -91,38 +102,41 @@ BOOL lookup_name(TALLOC_CTX *mem_ctx,
                        goto ok;
                }
                TALLOC_FREE(tmp_ctx);
-               return False;
+               return false;
        }
 
        /* Try the explicit winbind lookup first, don't let it guess the
         * domain yet at this point yet. This comes later. */
 
        if ((domain[0] != '\0') &&
+           (flags & ~(LOOKUP_NAME_DOMAIN|LOOKUP_NAME_ISOLATED)) &&
            (winbind_lookup_name(domain, name, &sid, &type))) {
                        goto ok;
        }
 
-       if (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;
                }
                TALLOC_FREE(tmp_ctx);
-               return False;
+               return false;
        }
 
-       if (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;
                }
                TALLOC_FREE(tmp_ctx);
-               return False;
+               return false;
        }
 
        if ((domain[0] == '\0') && (!(flags & LOOKUP_NAME_ISOLATED))) {
                TALLOC_FREE(tmp_ctx);
-               return False;
+               return false;
        }
 
        /* Now the guesswork begins, we haven't been given an explicit
@@ -132,14 +146,18 @@ BOOL lookup_name(TALLOC_CTX *mem_ctx,
 
        /* 1. well-known names */
 
-       if (lookup_wellknown_name(tmp_ctx, name, &sid, &domain)) {
+       if ((flags & LOOKUP_NAME_WKN) &&
+           lookup_wellknown_name(tmp_ctx, name, &sid, &domain))
+       {
                type = SID_NAME_WKN_GRP;
                goto ok;
        }
 
        /* 2. Builtin domain as such */
 
-       if (strequal(name, builtin_domain_name())) {
+       if ((flags & (LOOKUP_NAME_BUILTIN|LOOKUP_NAME_REMOTE)) &&
+           strequal(name, builtin_domain_name()))
+       {
                /* Swap domain and name */
                tmp = name; name = domain; domain = tmp;
                sid_copy(&sid, &global_sid_Builtin);
@@ -149,11 +167,13 @@ BOOL lookup_name(TALLOC_CTX *mem_ctx,
 
        /* 3. Account domain */
 
-       if (strequal(name, get_global_sam_name())) {
+       if ((flags & LOOKUP_NAME_DOMAIN) &&
+           strequal(name, get_global_sam_name()))
+       {
                if (!secrets_fetch_domain_sid(name, &sid)) {
                        DEBUG(3, ("Could not fetch my SID\n"));
                        TALLOC_FREE(tmp_ctx);
-                       return False;
+                       return false;
                }
                /* Swap domain and name */
                tmp = name; name = domain; domain = tmp;
@@ -163,11 +183,13 @@ BOOL lookup_name(TALLOC_CTX *mem_ctx,
 
        /* 4. Primary domain */
 
-       if (!IS_DC && strequal(name, lp_workgroup())) {
+       if ((flags & LOOKUP_NAME_DOMAIN) && !IS_DC &&
+           strequal(name, lp_workgroup()))
+       {
                if (!secrets_fetch_domain_sid(name, &sid)) {
                        DEBUG(3, ("Could not fetch the domain SID\n"));
                        TALLOC_FREE(tmp_ctx);
-                       return False;
+                       return false;
                }
                /* Swap domain and name */
                tmp = name; name = domain; domain = tmp;
@@ -178,7 +200,9 @@ BOOL lookup_name(TALLOC_CTX *mem_ctx,
        /* 5. Trusted domains as such, to me it looks as if members don't do
               this, tested an XP workstation in a NT domain -- vl */
 
-       if (IS_DC && (pdb_get_trusteddom_pw(name, NULL, &sid, NULL))) {
+       if ((flags & LOOKUP_NAME_REMOTE) && IS_DC &&
+           (pdb_get_trusteddom_pw(name, NULL, &sid, NULL)))
+       {
                /* Swap domain and name */
                tmp = name; name = domain; domain = tmp;
                type = SID_NAME_DOMAIN;
@@ -187,7 +211,9 @@ BOOL lookup_name(TALLOC_CTX *mem_ctx,
 
        /* 6. Builtin aliases */        
 
-       if (lookup_builtin_name(name, &rid)) {
+       if ((flags & LOOKUP_NAME_BUILTIN) &&
+           lookup_builtin_name(name, &rid))
+       {
                domain = talloc_strdup(tmp_ctx, builtin_domain_name());
                sid_copy(&sid, &global_sid_Builtin);
                sid_append_rid(&sid, rid);
@@ -200,7 +226,9 @@ BOOL lookup_name(TALLOC_CTX *mem_ctx,
 
        /* Both cases are done by looking at our passdb */
 
-       if (lookup_global_sam_name(name, flags, &rid, &type)) {
+       if ((flags & LOOKUP_NAME_DOMAIN) &&
+           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);
@@ -211,7 +239,7 @@ BOOL lookup_name(TALLOC_CTX *mem_ctx,
 
        if (!(flags & LOOKUP_NAME_REMOTE)) {
                TALLOC_FREE(tmp_ctx);
-               return False;
+               return false;
        }
 
        /* If we are not a DC, we have to ask in our primary domain. Let
@@ -252,7 +280,7 @@ BOOL lookup_name(TALLOC_CTX *mem_ctx,
                        DEBUG(2, ("winbind could not find the domain's name "
                                  "it just looked up for us\n"));
                        TALLOC_FREE(tmp_ctx);
-                       return False;
+                       return false;
                }
                goto ok;
        }
@@ -262,13 +290,15 @@ BOOL lookup_name(TALLOC_CTX *mem_ctx,
        /* 11. Ok, windows would end here. Samba has two more options:
                Unmapped users and unmapped groups */
 
-       if (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 (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;
@@ -279,13 +309,13 @@ BOOL lookup_name(TALLOC_CTX *mem_ctx,
         */
 
        TALLOC_FREE(tmp_ctx);
-       return False;
+       return false;
 
  ok:
        if ((domain == NULL) || (name == NULL)) {
                DEBUG(0, ("talloc failed\n"));
                TALLOC_FREE(tmp_ctx);
-               return False;
+               return false;
        }
 
        /*
@@ -296,7 +326,7 @@ BOOL lookup_name(TALLOC_CTX *mem_ctx,
            !(*ret_name = talloc_strdup(mem_ctx, name))) {
                DEBUG(0, ("talloc failed\n"));
                TALLOC_FREE(tmp_ctx);
-               return False;
+               return false;
        }
 
        if (ret_domain != NULL) {
@@ -304,7 +334,7 @@ BOOL lookup_name(TALLOC_CTX *mem_ctx,
                if (!(tmp_dom = talloc_strdup(mem_ctx, domain))) {
                        DEBUG(0, ("talloc failed\n"));
                        TALLOC_FREE(tmp_ctx);
-                       return False;
+                       return false;
                }
                strupper_m(tmp_dom);
                *ret_domain = tmp_dom;
@@ -319,7 +349,7 @@ BOOL lookup_name(TALLOC_CTX *mem_ctx,
        }
 
        TALLOC_FREE(tmp_ctx);
-       return True;
+       return true;
 }
 
 /************************************************************************
@@ -328,7 +358,7 @@ BOOL lookup_name(TALLOC_CTX *mem_ctx,
  and then "Unix Users"\foo (or "Unix Groups"\foo).
 ************************************************************************/
 
-BOOL lookup_name_smbconf(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)
@@ -348,7 +378,7 @@ BOOL lookup_name_smbconf(TALLOC_CTX *mem_ctx,
 
                        tmp = talloc_strdup(mem_ctx, full_name);
                        if (!tmp) {
-                               return False;
+                               return false;
                        }
                        tmp[p - full_name] = '\\';
                        full_name = tmp;
@@ -364,13 +394,13 @@ BOOL lookup_name_smbconf(TALLOC_CTX *mem_ctx,
                                get_global_sam_name(),
                                full_name );
        if (!qualified_name) {
-               return False;
+               return false;
        }
 
        if (lookup_name(mem_ctx, qualified_name, flags,
                                ret_domain, ret_name,
                                ret_sid, ret_type)) {
-               return True;
+               return true;
        }
        
        /* Finally try with "Unix Users" or "Unix Group" */
@@ -380,7 +410,7 @@ BOOL lookup_name_smbconf(TALLOC_CTX *mem_ctx,
                                        unix_users_domain_name(),
                                full_name );
        if (!qualified_name) {
-               return False;
+               return false;
        }
 
        return lookup_name(mem_ctx, qualified_name, flags,
@@ -388,7 +418,7 @@ BOOL lookup_name_smbconf(TALLOC_CTX *mem_ctx,
                                ret_sid, ret_type);
 }
 
-static BOOL wb_lookup_rids(TALLOC_CTX *mem_ctx,
+static bool wb_lookup_rids(TALLOC_CTX *mem_ctx,
                           const DOM_SID *domain_sid,
                           int num_rids, uint32 *rids,
                           const char **domain_name,
@@ -400,7 +430,7 @@ static BOOL wb_lookup_rids(TALLOC_CTX *mem_ctx,
        TALLOC_CTX *tmp_ctx;
 
        if (!(tmp_ctx = talloc_init("wb_lookup_rids"))) {
-               return False;
+               return false;
        }
 
        if (!winbind_lookup_rids(tmp_ctx, domain_sid, num_rids, rids,
@@ -411,12 +441,12 @@ static BOOL wb_lookup_rids(TALLOC_CTX *mem_ctx,
                        types[i] = SID_NAME_UNKNOWN;
                }
                TALLOC_FREE(tmp_ctx);
-               return True;
+               return true;
        }
 
        if (!(*domain_name = talloc_strdup(mem_ctx, *domain_name))) {
                TALLOC_FREE(tmp_ctx);
-               return False;
+               return false;
        }
 
        /*
@@ -427,32 +457,38 @@ static BOOL wb_lookup_rids(TALLOC_CTX *mem_ctx,
        for (i=0; i<num_rids; i++) {
                if (my_names[i] == NULL) {
                        TALLOC_FREE(tmp_ctx);
-                       return False;
+                       return false;
                }
                if (!(names[i] = talloc_strdup(names, my_names[i]))) {
                        TALLOC_FREE(tmp_ctx);
-                       return False;
+                       return false;
                }
                types[i] = my_types[i];
        }
        TALLOC_FREE(tmp_ctx);
-       return True;
+       return true;
 }
 
-static BOOL lookup_rids(TALLOC_CTX *mem_ctx, const DOM_SID *domain_sid,
+static bool lookup_rids(TALLOC_CTX *mem_ctx, const DOM_SID *domain_sid,
                        int num_rids, uint32_t *rids,
                        const char **domain_name,
                        const char ***names, enum lsa_SidType **types)
 {
        int i;
 
+       DEBUG(10, ("lookup_rids called for domain sid '%s'\n",
+                  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;
+                       return false;
                }
+
+               for (i = 0; i < num_rids; i++)
+                       (*types)[i] = SID_NAME_UNKNOWN;
        } else {
                *names = NULL;
                *types = NULL;
@@ -467,7 +503,7 @@ static BOOL lookup_rids(TALLOC_CTX *mem_ctx, const DOM_SID *domain_sid,
                }
 
                if (*domain_name == NULL) {
-                       return False;
+                       return false;
                }
 
                become_root();
@@ -488,21 +524,21 @@ static BOOL lookup_rids(TALLOC_CTX *mem_ctx, const DOM_SID *domain_sid,
                }
 
                if (*domain_name == NULL) {
-                       return False;
+                       return false;
                }
 
                for (i=0; i<num_rids; i++) {
                        if (lookup_builtin_rid(*names, rids[i],
                                               &(*names)[i])) {
                                if ((*names)[i] == NULL) {
-                                       return False;
+                                       return false;
                                }
                                (*types)[i] = SID_NAME_ALIAS;
                        } else {
                                (*types)[i] = SID_NAME_UNKNOWN;
                        }
                }
-               return True;
+               return true;
        }
 
        if (sid_check_is_wellknown_domain(domain_sid, NULL)) {
@@ -513,40 +549,52 @@ static BOOL lookup_rids(TALLOC_CTX *mem_ctx, const DOM_SID *domain_sid,
                        if (lookup_wellknown_sid(mem_ctx, &sid,
                                                 domain_name, &(*names)[i])) {
                                if ((*names)[i] == NULL) {
-                                       return False;
+                                       return false;
                                }
                                (*types)[i] = SID_NAME_WKN_GRP;
                        } else {
                                (*types)[i] = SID_NAME_UNKNOWN;
                        }
                }
-               return True;
+               return true;
        }
 
        if (sid_check_is_unix_users(domain_sid)) {
                if (*domain_name == NULL) {
                        *domain_name = talloc_strdup(
                                mem_ctx, unix_users_domain_name());
+                       if (*domain_name == NULL) {
+                               return false;
+                       }
                }
                for (i=0; i<num_rids; i++) {
                        (*names)[i] = talloc_strdup(
                                (*names), uidtoname(rids[i]));
+                       if ((*names)[i] == NULL) {
+                               return false;
+                       }
                        (*types)[i] = SID_NAME_USER;
                }
-               return True;
+               return true;
        }
 
        if (sid_check_is_unix_groups(domain_sid)) {
                if (*domain_name == NULL) {
                        *domain_name = talloc_strdup(
                                mem_ctx, unix_groups_domain_name());
+                       if (*domain_name == NULL) {
+                               return false;
+                       }
                }
                for (i=0; i<num_rids; i++) {
                        (*names)[i] = talloc_strdup(
                                (*names), gidtoname(rids[i]));
+                       if ((*names)[i] == NULL) {
+                               return false;
+                       }
                        (*types)[i] = SID_NAME_DOM_GRP;
                }
-               return True;
+               return true;
        }
 
        return wb_lookup_rids(mem_ctx, domain_sid, num_rids, rids,
@@ -557,7 +605,7 @@ 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 DOM_SID *sid, TALLOC_CTX *mem_ctx,
                             const char **name)
 {
        const char *tmp;
@@ -565,22 +613,32 @@ static BOOL lookup_as_domain(const DOM_SID *sid, TALLOC_CTX *mem_ctx,
 
        if (sid_check_is_domain(sid)) {
                *name = talloc_strdup(mem_ctx, get_global_sam_name());
-               return True;
+               return true;
        }
 
        if (sid_check_is_builtin(sid)) {
                *name = talloc_strdup(mem_ctx, builtin_domain_name());
-               return True;
+               return true;
        }
 
        if (sid_check_is_wellknown_domain(sid, &tmp)) {
                *name = talloc_strdup(mem_ctx, tmp);
-               return True;
+               return true;
+       }
+
+       if (sid_check_is_unix_users(sid)) {
+               *name = talloc_strdup(mem_ctx, unix_users_domain_name());
+               return true;
+       }
+
+       if (sid_check_is_unix_groups(sid)) {
+               *name = talloc_strdup(mem_ctx, unix_groups_domain_name());
+               return true;
        }
 
        if (sid->num_auths != 4) {
                /* This can't be a domain */
-               return False;
+               return false;
        }
 
        if (IS_DC) {
@@ -594,26 +652,26 @@ static BOOL lookup_as_domain(const DOM_SID *sid, TALLOC_CTX *mem_ctx,
                if (!NT_STATUS_IS_OK(pdb_enum_trusteddoms(mem_ctx,
                                                          &num_domains,
                                                          &domains))) {
-                       return False;
+                       return false;
                }
 
                for (i=0; i<num_domains; i++) {
                        if (sid_equal(sid, &domains[i]->sid)) {
                                *name = talloc_strdup(mem_ctx,
                                                      domains[i]->name);
-                               return True;
+                               return true;
                        }
                }
-               return False;
+               return false;
        }
 
        if (winbind_lookup_sid(mem_ctx, sid, &tmp, NULL, &type) &&
            (type == SID_NAME_DOMAIN)) {
                *name = tmp;
-               return True;
+               return true;
        }
 
-       return False;
+       return false;
 }
 
 /*
@@ -631,17 +689,17 @@ static BOOL lookup_as_domain(const DOM_SID *sid, TALLOC_CTX *mem_ctx,
  * Level 2: Ask domain and trusted domains, no builtin and wkn
  * Level 3: Only ask domain
  * Level 4: W2k3ad: Only ask AD trusts
- * Level 5: Don't lookup anything
+ * Level 5: Only ask transitive forest trusts
  * 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 DOM_SID *sid, int level)
 {
-       int ret = False;
+       int ret = false;
 
        switch(level) {
        case 1:
-               ret = True;
+               ret = true;
                break;
        case 2:
                ret = (!sid_check_is_builtin(sid) &&
@@ -653,13 +711,13 @@ static BOOL check_dom_sid_to_level(const DOM_SID *sid, int level)
                ret = sid_check_is_domain(sid);
                break;
        case 5:
-               ret = False;
+               ret = false;
                break;
        }
 
        DEBUG(10, ("%s SID %s in level %d\n",
                   ret ? "Accepting" : "Rejecting",
-                  sid_string_static(sid), level));
+                  sid_string_dbg(sid), level));
        return ret;
 }
 
@@ -703,7 +761,7 @@ 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;
@@ -761,7 +819,7 @@ 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;
                        }
                }
@@ -773,7 +831,7 @@ 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;
                        }
@@ -782,7 +840,7 @@ 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;
@@ -791,7 +849,7 @@ NTSTATUS lookup_sids(TALLOC_CTX *mem_ctx, int num_sids,
                if (!dom_infos[j].valid) {
                        /* We found a domain not yet referenced, create a new
                         * ref. */
-                       dom_infos[j].valid = True;
+                       dom_infos[j].valid = true;
                        sid_copy(&dom_infos[j].sid, &sid);
 
                        if (domain_name != NULL) {
@@ -826,7 +884,7 @@ 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;
@@ -881,6 +939,7 @@ NTSTATUS lookup_sids(TALLOC_CTX *mem_ctx, int num_sids,
 
        *ret_domains = dom_infos;
        *ret_names = name_infos;
+       TALLOC_FREE(tmp_ctx);
        return NT_STATUS_OK;
 
  fail:
@@ -894,18 +953,20 @@ 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 DOM_SID *sid,
                const char **ret_domain, const char **ret_name,
                enum lsa_SidType *ret_type)
 {
        struct lsa_dom_info *domain;
        struct lsa_name_info *name;
        TALLOC_CTX *tmp_ctx;
-       BOOL ret = False;
+       bool ret = false;
+
+       DEBUG(10, ("lookup_sid called for SID '%s'\n", sid_string_dbg(sid)));
 
        if (!(tmp_ctx = talloc_new(mem_ctx))) {
                DEBUG(0, ("talloc_new failed\n"));
-               return False;
+               return false;
        }
 
        if (!NT_STATUS_IS_OK(lookup_sids(tmp_ctx, 1, &sid, 1,
@@ -931,16 +992,14 @@ BOOL lookup_sid(TALLOC_CTX *mem_ctx, const DOM_SID *sid,
                *ret_type = name->type;
        }
 
-       ret = True;
+       ret = true;
 
  done:
        if (ret) {
-               DEBUG(10, ("Sid %s -> %s\\%s(%d)\n",
-                          sid_string_static(sid), domain->name,
-                          name->name, name->type));
+               DEBUG(10, ("Sid %s -> %s\\%s(%d)\n", sid_string_dbg(sid),
+                          domain->name, name->name, name->type));
        } else {
-               DEBUG(10, ("failed to lookup sid %s\n",
-                          sid_string_static(sid)));
+               DEBUG(10, ("failed to lookup sid %s\n", sid_string_dbg(sid)));
        }
        TALLOC_FREE(tmp_ctx);
        return ret;
@@ -954,184 +1013,114 @@ BOOL lookup_sid(TALLOC_CTX *mem_ctx, const DOM_SID *sid,
  modified to use linked lists by jra.
 *****************************************************************/  
 
-#define MAX_UID_SID_CACHE_SIZE 100
-#define TURNOVER_UID_SID_CACHE_SIZE 10
-#define MAX_GID_SID_CACHE_SIZE 100
-#define TURNOVER_GID_SID_CACHE_SIZE 10
-
-static size_t n_uid_sid_cache = 0;
-static size_t n_gid_sid_cache = 0;
-
-static struct uid_sid_cache {
-       struct uid_sid_cache *next, *prev;
-       uid_t uid;
-       DOM_SID sid;
-       enum lsa_SidType sidtype;
-} *uid_sid_cache_head;
-
-static struct gid_sid_cache {
-       struct gid_sid_cache *next, *prev;
-       gid_t gid;
-       DOM_SID sid;
-       enum lsa_SidType sidtype;
-} *gid_sid_cache_head;
-
 /*****************************************************************
   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(DOM_SID *psid, uid_t uid)
 {
-       struct uid_sid_cache *pc;
-
-       for (pc = uid_sid_cache_head; pc; pc = pc->next) {
-               if (pc->uid == uid) {
-                       *psid = pc->sid;
-                       DEBUG(3,("fetch sid from uid cache %u -> %s\n",
-                                (unsigned int)uid, sid_string_static(psid)));
-                       DLIST_PROMOTE(uid_sid_cache_head, pc);
-                       return True;
-               }
+       DATA_BLOB cache_value;
+
+       if (!memcache_lookup(NULL, UID_SID_CACHE,
+                            data_blob_const(&uid, sizeof(uid)),
+                            &cache_value)) {
+               return false;
        }
-       return False;
+
+       memcpy(psid, cache_value.data, MIN(sizeof(*psid), cache_value.length));
+       SMB_ASSERT(cache_value.length >= offsetof(struct dom_sid, id_auth));
+       SMB_ASSERT(cache_value.length == ndr_size_dom_sid(psid, NULL, 0));
+
+       return true;
 }
 
 /*****************************************************************
   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 DOM_SID *psid )
 {
-       struct uid_sid_cache *pc;
-
-       for (pc = uid_sid_cache_head; pc; pc = pc->next) {
-               if (sid_compare(&pc->sid, psid) == 0) {
-                       *puid = pc->uid;
-                       DEBUG(3,("fetch uid from cache %u -> %s\n",
-                                (unsigned int)*puid, sid_string_static(psid)));
-                       DLIST_PROMOTE(uid_sid_cache_head, pc);
-                       return True;
-               }
+       DATA_BLOB cache_value;
+
+       if (!memcache_lookup(NULL, SID_UID_CACHE,
+                            data_blob_const(psid, ndr_size_dom_sid(psid, NULL, 0)),
+                            &cache_value)) {
+               return false;
        }
-       return False;
+
+       SMB_ASSERT(cache_value.length == sizeof(*puid));
+       memcpy(puid, cache_value.data, sizeof(*puid));
+
+       return true;
 }
 
 /*****************************************************************
  Store uid to SID mapping in cache.
-*****************************************************************/  
+*****************************************************************/
 
 void store_uid_sid_cache(const DOM_SID *psid, uid_t uid)
 {
-       struct uid_sid_cache *pc;
-
-       /* do not store SIDs in the "Unix Group" domain */
-       
-       if ( sid_check_is_in_unix_users( psid ) )
-               return;
-
-       if (n_uid_sid_cache >= MAX_UID_SID_CACHE_SIZE && n_uid_sid_cache > TURNOVER_UID_SID_CACHE_SIZE) {
-               /* Delete the last TURNOVER_UID_SID_CACHE_SIZE entries. */
-               struct uid_sid_cache *pc_next;
-               size_t i;
-
-               for (i = 0, pc = uid_sid_cache_head; i < (n_uid_sid_cache - TURNOVER_UID_SID_CACHE_SIZE); i++, pc = pc->next)
-                       ;
-               for(; pc; pc = pc_next) {
-                       pc_next = pc->next;
-                       DLIST_REMOVE(uid_sid_cache_head,pc);
-                       SAFE_FREE(pc);
-                       n_uid_sid_cache--;
-               }
-       }
-
-       pc = SMB_MALLOC_P(struct uid_sid_cache);
-       if (!pc)
-               return;
-       pc->uid = uid;
-       sid_copy(&pc->sid, psid);
-       DLIST_ADD(uid_sid_cache_head, pc);
-       n_uid_sid_cache++;
+       memcache_add(NULL, SID_UID_CACHE,
+                    data_blob_const(psid, ndr_size_dom_sid(psid, NULL, 0)),
+                    data_blob_const(&uid, sizeof(uid)));
+       memcache_add(NULL, UID_SID_CACHE,
+                    data_blob_const(&uid, sizeof(uid)),
+                    data_blob_const(psid, ndr_size_dom_sid(psid, NULL, 0)));
 }
 
 /*****************************************************************
   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(DOM_SID *psid, gid_t gid)
 {
-       struct gid_sid_cache *pc;
-
-       for (pc = gid_sid_cache_head; pc; pc = pc->next) {
-               if (pc->gid == gid) {
-                       *psid = pc->sid;
-                       DEBUG(3,("fetch sid from gid cache %u -> %s\n",
-                                (unsigned int)gid, sid_string_static(psid)));
-                       DLIST_PROMOTE(gid_sid_cache_head, pc);
-                       return True;
-               }
+       DATA_BLOB cache_value;
+
+       if (!memcache_lookup(NULL, GID_SID_CACHE,
+                            data_blob_const(&gid, sizeof(gid)),
+                            &cache_value)) {
+               return false;
        }
-       return False;
+
+       memcpy(psid, cache_value.data, MIN(sizeof(*psid), cache_value.length));
+       SMB_ASSERT(cache_value.length >= offsetof(struct dom_sid, id_auth));
+       SMB_ASSERT(cache_value.length == ndr_size_dom_sid(psid, NULL, 0));
+
+       return true;
 }
 
 /*****************************************************************
   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 DOM_SID *psid)
 {
-       struct gid_sid_cache *pc;
-
-       for (pc = gid_sid_cache_head; pc; pc = pc->next) {
-               if (sid_compare(&pc->sid, psid) == 0) {
-                       *pgid = pc->gid;
-                       DEBUG(3,("fetch gid from cache %u -> %s\n",
-                                (unsigned int)*pgid, sid_string_static(psid)));
-                       DLIST_PROMOTE(gid_sid_cache_head, pc);
-                       return True;
-               }
+       DATA_BLOB cache_value;
+
+       if (!memcache_lookup(NULL, SID_GID_CACHE,
+                            data_blob_const(psid, ndr_size_dom_sid(psid, NULL, 0)),
+                            &cache_value)) {
+               return false;
        }
-       return False;
+
+       SMB_ASSERT(cache_value.length == sizeof(*pgid));
+       memcpy(pgid, cache_value.data, sizeof(*pgid));
+
+       return true;
 }
 
 /*****************************************************************
  Store gid to SID mapping in cache.
-*****************************************************************/  
+*****************************************************************/
 
 void store_gid_sid_cache(const DOM_SID *psid, gid_t gid)
 {
-       struct gid_sid_cache *pc;
-       
-       /* do not store SIDs in the "Unix Group" domain */
-       
-       if ( sid_check_is_in_unix_groups( psid ) )
-               return;
-
-       if (n_gid_sid_cache >= MAX_GID_SID_CACHE_SIZE && n_gid_sid_cache > TURNOVER_GID_SID_CACHE_SIZE) {
-               /* Delete the last TURNOVER_GID_SID_CACHE_SIZE entries. */
-               struct gid_sid_cache *pc_next;
-               size_t i;
-
-               for (i = 0, pc = gid_sid_cache_head; i < (n_gid_sid_cache - TURNOVER_GID_SID_CACHE_SIZE); i++, pc = pc->next)
-                       ;
-               for(; pc; pc = pc_next) {
-                       pc_next = pc->next;
-                       DLIST_REMOVE(gid_sid_cache_head,pc);
-                       SAFE_FREE(pc);
-                       n_gid_sid_cache--;
-               }
-       }
-
-       pc = SMB_MALLOC_P(struct gid_sid_cache);
-       if (!pc)
-               return;
-       pc->gid = gid;
-       sid_copy(&pc->sid, psid);
-       DLIST_ADD(gid_sid_cache_head, pc);
-
-       DEBUG(3,("store_gid_sid_cache: gid %u in cache -> %s\n", (unsigned int)gid,
-               sid_string_static(psid)));
-
-       n_gid_sid_cache++;
+       memcache_add(NULL, SID_GID_CACHE,
+                    data_blob_const(psid, ndr_size_dom_sid(psid, NULL, 0)),
+                    data_blob_const(&gid, sizeof(gid)));
+       memcache_add(NULL, GID_SID_CACHE,
+                    data_blob_const(&gid, sizeof(gid)),
+                    data_blob_const(psid, ndr_size_dom_sid(psid, NULL, 0)));
 }
 
 /*****************************************************************
@@ -1141,7 +1130,7 @@ void store_gid_sid_cache(const DOM_SID *psid, gid_t gid)
 static void legacy_uid_to_sid(DOM_SID *psid, uid_t uid)
 {
        uint32 rid;
-       BOOL ret;
+       bool ret;
 
        ZERO_STRUCTP(psid);
 
@@ -1162,7 +1151,7 @@ static void legacy_uid_to_sid(DOM_SID *psid, uid_t uid)
 
  done:
        DEBUG(10,("LEGACY: uid %u -> sid %s\n", (unsigned int)uid,
-                 sid_string_static(psid)));
+                 sid_string_dbg(psid)));
 
        store_uid_sid_cache(psid, uid);
        return;
@@ -1174,7 +1163,7 @@ static void legacy_uid_to_sid(DOM_SID *psid, uid_t uid)
 
 static void legacy_gid_to_sid(DOM_SID *psid, gid_t gid)
 {
-       BOOL ret;
+       bool ret;
 
        ZERO_STRUCTP(psid);
 
@@ -1193,7 +1182,7 @@ static void legacy_gid_to_sid(DOM_SID *psid, gid_t gid)
 
  done:
        DEBUG(10,("LEGACY: gid %u -> sid %s\n", (unsigned int)gid,
-                 sid_string_static(psid)));
+                 sid_string_dbg(psid)));
 
        store_gid_sid_cache(psid, gid);
        return;
@@ -1203,14 +1192,14 @@ static void legacy_gid_to_sid(DOM_SID *psid, gid_t gid)
  *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 DOM_SID *psid, uid_t *puid)
 {
        enum lsa_SidType type;
        uint32 rid;
 
        if (sid_peek_check_rid(get_global_sam_sid(), psid, &rid)) {
                union unid_t id;
-               BOOL ret;
+               bool ret;
 
                become_root();
                ret = pdb_sid_to_id(psid, &id, &type);
@@ -1219,9 +1208,9 @@ static BOOL legacy_sid_to_uid(const DOM_SID *psid, uid_t *puid)
                if (ret) {
                        if (type != SID_NAME_USER) {
                                DEBUG(5, ("sid %s is a %s, expected a user\n",
-                                         sid_string_static(psid),
+                                         sid_string_dbg(psid),
                                          sid_type_lookup(type)));
-                               return False;
+                               return false;
                        }
                        *puid = id.uid;
                        goto done;
@@ -1230,15 +1219,16 @@ static BOOL legacy_sid_to_uid(const DOM_SID *psid, uid_t *puid)
                /* This was ours, but it was not mapped.  Fail */
        }
 
-       DEBUG(10,("LEGACY: mapping failed for sid %s\n", sid_string_static(psid)));
-       return False;
+       DEBUG(10,("LEGACY: mapping failed for sid %s\n",
+                 sid_string_dbg(psid)));
+       return false;
 
 done:
-       DEBUG(10,("LEGACY: sid %s -> uid %u\n", sid_string_static(psid),
-               (unsigned int)*puid ));
+       DEBUG(10,("LEGACY: sid %s -> uid %u\n", sid_string_dbg(psid),
+                 (unsigned int)*puid ));
 
        store_uid_sid_cache(psid, *puid);
-       return True;
+       return true;
 }
 
 /*****************************************************************
@@ -1246,7 +1236,7 @@ done:
  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 DOM_SID *psid, gid_t *pgid)
 {
        uint32 rid;
        GROUP_MAP map;
@@ -1255,7 +1245,7 @@ static BOOL legacy_sid_to_gid(const DOM_SID *psid, gid_t *pgid)
 
        if ((sid_check_is_in_builtin(psid) ||
             sid_check_is_in_wellknown_domain(psid))) {
-               BOOL ret;
+               bool ret;
 
                become_root();
                ret = pdb_getgrsid(&map, *psid);
@@ -1265,12 +1255,13 @@ static BOOL legacy_sid_to_gid(const DOM_SID *psid, gid_t *pgid)
                        *pgid = map.gid;
                        goto done;
                }
-               DEBUG(10,("LEGACY: mapping failed for sid %s\n", sid_string_static(psid)));
-               return False;
+               DEBUG(10,("LEGACY: mapping failed for sid %s\n",
+                         sid_string_dbg(psid)));
+               return false;
        }
 
        if (sid_peek_check_rid(get_global_sam_sid(), psid, &rid)) {
-               BOOL ret;
+               bool ret;
 
                become_root();
                ret = pdb_sid_to_id(psid, &id, &type);
@@ -1279,10 +1270,10 @@ static BOOL legacy_sid_to_gid(const DOM_SID *psid, gid_t *pgid)
                if (ret) {
                        if ((type != SID_NAME_DOM_GRP) &&
                            (type != SID_NAME_ALIAS)) {
-                               DEBUG(5, ("LEGACY: sid %s is a %s, expected a group\n",
-                                         sid_string_static(psid),
+                               DEBUG(5, ("LEGACY: sid %s is a %s, expected "
+                                         "a group\n", sid_string_dbg(psid),
                                          sid_type_lookup(type)));
-                               return False;
+                               return false;
                        }
                        *pgid = id.gid;
                        goto done;
@@ -1291,16 +1282,17 @@ static BOOL legacy_sid_to_gid(const DOM_SID *psid, gid_t *pgid)
                /* This was ours, but it was not mapped.  Fail */
        }
 
-       DEBUG(10,("LEGACY: mapping failed for sid %s\n", sid_string_static(psid)));
-       return False;
+       DEBUG(10,("LEGACY: mapping failed for sid %s\n",
+                 sid_string_dbg(psid)));
+       return false;
        
  done:
-       DEBUG(10,("LEGACY: sid %s -> gid %u\n", sid_string_static(psid),
+       DEBUG(10,("LEGACY: sid %s -> gid %u\n", sid_string_dbg(psid),
                  (unsigned int)*pgid ));
 
        store_gid_sid_cache(psid, *pgid);
 
-       return True;
+       return true;
 }
 
 /*****************************************************************
@@ -1309,24 +1301,48 @@ static BOOL legacy_sid_to_gid(const DOM_SID *psid, gid_t *pgid)
 
 void uid_to_sid(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, sid_string_static(psid)));
+       DEBUG(10,("uid %u -> sid %s\n", (unsigned int)uid,
+                 sid_string_dbg(psid)));
 
        store_uid_sid_cache(psid, uid);
        return;
@@ -1338,25 +1354,49 @@ void uid_to_sid(DOM_SID *psid, uid_t uid)
 
 void gid_to_sid(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_static(psid)));
-       
+       DEBUG(10,("gid %u -> sid %s\n", (unsigned int)gid,
+                 sid_string_dbg(psid)));
+
        store_gid_sid_cache(psid, gid);
        return;
 }
@@ -1365,16 +1405,18 @@ void gid_to_sid(DOM_SID *psid, gid_t gid)
  *THE CANONICAL* convert SID to uid function.
 *****************************************************************/  
 
-BOOL sid_to_uid(const DOM_SID *psid, uid_t *puid)
+bool sid_to_uid(const DOM_SID *psid, uid_t *puid)
 {
+       bool expired = true;
+       bool ret;
        uint32 rid;
        gid_t gid;
 
        if (fetch_uid_from_cache(puid, psid))
-               return True;
+               return true;
 
        if (fetch_gid_from_cache(&gid, psid)) {
-               return False;
+               return false;
        }
 
        /* Optimize for the Unix Users Domain
@@ -1384,29 +1426,40 @@ BOOL sid_to_uid(const DOM_SID *psid, uid_t *puid)
                *puid = uid;
 
                /* return here, don't cache */
-               DEBUG(10,("sid %s -> uid %u\n", sid_string_static(psid),
+               DEBUG(10,("sid %s -> uid %u\n", sid_string_dbg(psid),
                        (unsigned int)*puid ));
-               return True;
+               return true;
+       }
+
+       /* 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 (!winbind_sid_to_uid(puid, psid)) {
-               if (!winbind_ping()) {
+       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_static(psid)));
-               return False;
        }
 
        /* TODO: Here would be the place to allocate both a gid and a uid for
         * the SID in question */
 
-       DEBUG(10,("sid %s -> uid %u\n", sid_string_static(psid),
+       DEBUG(10,("sid %s -> uid %u\n", sid_string_dbg(psid),
                (unsigned int)*puid ));
 
        store_uid_sid_cache(psid, *puid);
-       return True;
+       return true;
 }
 
 /*****************************************************************
@@ -1414,16 +1467,18 @@ BOOL sid_to_uid(const DOM_SID *psid, uid_t *puid)
  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 DOM_SID *psid, gid_t *pgid)
 {
+       bool expired = true;
+       bool ret;
        uint32 rid;
        uid_t uid;
 
        if (fetch_gid_from_cache(pgid, psid))
-               return True;
+               return true;
 
        if (fetch_uid_from_cache(&uid, psid))
-               return False;
+               return false;
 
        /* Optimize for the Unix Groups Domain
         * as the conversion is straightforward */
@@ -1432,29 +1487,39 @@ BOOL sid_to_gid(const DOM_SID *psid, gid_t *pgid)
                *pgid = gid;
 
                /* return here, don't cache */
-               DEBUG(10,("sid %s -> gid %u\n", sid_string_static(psid),
+               DEBUG(10,("sid %s -> gid %u\n", sid_string_dbg(psid),
                        (unsigned int)*pgid ));
-               return True;
+               return true;
+       }
+
+       /* 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);
        }
 
-       /* 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 (!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_sid_to_gid(pgid, psid) ) {
-               if (!winbind_ping()) {
+                       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_static(psid)));
-               return False;
        }
 
-       DEBUG(10,("sid %s -> gid %u\n", sid_string_static(psid),
+       DEBUG(10,("sid %s -> gid %u\n", sid_string_dbg(psid),
                  (unsigned int)*pgid ));
 
        store_gid_sid_cache(psid, *pgid);
-       
-       return True;
+       return true;
 }
-