r22978: Don't use current_user to prep the security ctx in change_to_user
[tprouty/samba.git] / source / smbd / uid.c
index 240b4d46bbd42c6f6296ae544efb9d8b804779d3..c6d4e3329c8b9ff8513c20c8eed2dd257dc51e7c 100644 (file)
@@ -1,6 +1,5 @@
 /* 
-   Unix SMB/Netbios implementation.
-   Version 1.9.
+   Unix SMB/CIFS implementation.
    uid/user handling
    Copyright (C) Andrew Tridgell 1992-1998
    
 /* what user is current? */
 extern struct current_user current_user;
 
+/****************************************************************************
+ Iterator functions for getting all gid's from current_user.
+****************************************************************************/
+
+gid_t get_current_user_gid_first(int *piterator)
+{
+       *piterator = 0;
+       return current_user.ut.gid;
+}
+
+gid_t get_current_user_gid_next(int *piterator)
+{
+       gid_t ret;
+
+       if (!current_user.ut.groups || *piterator >= current_user.ut.ngroups) {
+               return (gid_t)-1;
+       }
+
+       ret = current_user.ut.groups[*piterator];
+       (*piterator) += 1;
+       return ret;
+}
+
 /****************************************************************************
  Become the guest user without changing the security context stack.
 ****************************************************************************/
@@ -34,7 +56,7 @@ BOOL change_to_guest(void)
 
        if (!pass) {
                /* Don't need to free() this as its stored in a static */
-               pass = getpwnam_alloc(lp_guestaccount());
+               pass = getpwnam_alloc(NULL, lp_guestaccount());
                if (!pass)
                        return(False);
        }
@@ -49,6 +71,9 @@ BOOL change_to_guest(void)
        
        current_user.conn = NULL;
        current_user.vuid = UID_FIELD_INVALID;
+
+       TALLOC_FREE(pass);
+       pass = NULL;
        
        return True;
 }
@@ -59,26 +84,67 @@ BOOL change_to_guest(void)
 
 static BOOL check_user_ok(connection_struct *conn, user_struct *vuser,int snum)
 {
-       int i;
-       for (i=0;i<conn->uid_cache.entries;i++)
-               if (conn->uid_cache.list[i] == vuser->uid)
+       unsigned int i;
+       struct vuid_cache_entry *ent = NULL;
+       BOOL readonly_share;
+       NT_USER_TOKEN *token;
+
+       for (i=0;i<conn->vuid_cache.entries && i< VUID_CACHE_SIZE;i++) {
+               if (conn->vuid_cache.array[i].vuid == vuser->vuid) {
+                       ent = &conn->vuid_cache.array[i];
+                       conn->read_only = ent->read_only;
+                       conn->admin_user = ent->admin_user;
                        return(True);
+               }
+       }
 
-       if (!user_ok(vuser->user.unix_name,snum))
+       if (!user_ok_token(vuser->user.unix_name, vuser->nt_user_token, snum))
                return(False);
 
-       i = conn->uid_cache.entries % UID_CACHE_SIZE;
-       conn->uid_cache.list[i] = vuser->uid;
+       readonly_share = is_share_read_only_for_token(vuser->user.unix_name,
+                                                     vuser->nt_user_token,
+                                                     SNUM(conn));
+
+       token = conn->nt_user_token ?
+               conn->nt_user_token : vuser->nt_user_token;
+
+       if (!readonly_share &&
+           !share_access_check(token, lp_servicename(snum),
+                               FILE_WRITE_DATA)) {
+               /* smb.conf allows r/w, but the security descriptor denies
+                * write. Fall back to looking at readonly. */
+               readonly_share = True;
+               DEBUG(5,("falling back to read-only access-evaluation due to "
+                        "security descriptor\n"));
+       }
 
-       if (conn->uid_cache.entries < UID_CACHE_SIZE)
-               conn->uid_cache.entries++;
+       if (!share_access_check(token, lp_servicename(snum),
+                               readonly_share ?
+                               FILE_READ_DATA : FILE_WRITE_DATA)) {
+               return False;
+       }
+
+       i = conn->vuid_cache.entries % VUID_CACHE_SIZE;
+       if (conn->vuid_cache.entries < VUID_CACHE_SIZE)
+               conn->vuid_cache.entries++;
+
+       ent = &conn->vuid_cache.array[i];
+       ent->vuid = vuser->vuid;
+       ent->read_only = readonly_share;
+
+       ent->admin_user = token_contains_name_in_list(
+               vuser->user.unix_name, NULL, vuser->nt_user_token,
+               lp_admin_users(SNUM(conn)));
+
+       conn->read_only = ent->read_only;
+       conn->admin_user = ent->admin_user;
 
        return(True);
 }
 
 /****************************************************************************
  Become the user of a connection number without changing the security context
- stack, but modify the currnet_user entries.
+ stack, but modify the current_user entries.
 ****************************************************************************/
 
 BOOL change_to_user(connection_struct *conn, uint16 vuid)
@@ -90,7 +156,9 @@ BOOL change_to_user(connection_struct *conn, uint16 vuid)
        char group_c;
        BOOL must_free_token = False;
        NT_USER_TOKEN *token = NULL;
-
+       int num_groups = 0;
+       gid_t *group_list = NULL;
+       
        if (!conn) {
                DEBUG(2,("change_to_user: Connection not open\n"));
                return(False);
@@ -104,39 +172,44 @@ BOOL change_to_user(connection_struct *conn, uint16 vuid)
         */
 
        if((lp_security() == SEC_SHARE) && (current_user.conn == conn) &&
-          (current_user.uid == conn->uid)) {
-               DEBUG(4,("change_to_user: Skipping user change - already user\n"));
+          (current_user.ut.uid == conn->uid)) {
+               DEBUG(4,("change_to_user: Skipping user change - already "
+                        "user\n"));
                return(True);
        } else if ((current_user.conn == conn) && 
                   (vuser != 0) && (current_user.vuid == vuid) && 
-                  (current_user.uid == vuser->uid)) {
-               DEBUG(4,("change_to_user: Skipping user change - already user\n"));
+                  (current_user.ut.uid == vuser->uid)) {
+               DEBUG(4,("change_to_user: Skipping user change - already "
+                        "user\n"));
                return(True);
        }
 
        snum = SNUM(conn);
 
-       if((vuser != NULL) && !check_user_ok(conn, vuser, snum))
+       if ((vuser) && !check_user_ok(conn, vuser, snum)) {
+               DEBUG(2,("change_to_user: SMB user %s (unix user %s, vuid %d) "
+                        "not permitted access to share %s.\n",
+                        vuser->user.smb_name, vuser->user.unix_name, vuid,
+                        lp_servicename(snum)));
                return False;
+       }
 
-       if (conn->force_user || 
-               conn->admin_user ||
-           (lp_security() == SEC_SHARE)) {
+       if (conn->force_user) /* security = share sets this too */ {
                uid = conn->uid;
                gid = conn->gid;
-               current_user.groups = conn->groups;
-               current_user.ngroups = conn->ngroups;
+               group_list = conn->groups;
+               num_groups = conn->ngroups;
                token = conn->nt_user_token;
-       } else {
-               if (!vuser) {
-                       DEBUG(2,("change_to_user: Invalid vuid used %d\n",vuid));
-                       return(False);
-               }
-               uid = vuser->uid;
+       } else if (vuser) {
+               uid = conn->admin_user ? 0 : vuser->uid;
                gid = vuser->gid;
-               current_user.ngroups = vuser->n_groups;
-               current_user.groups  = vuser->groups;
+               num_groups = vuser->n_groups;
+               group_list  = vuser->groups;
                token = vuser->nt_user_token;
+       } else {
+               DEBUG(2,("change_to_user: Invalid vuid used %d in accessing "
+                        "share %s.\n",vuid, lp_servicename(snum) ));
+               return False;
        }
 
        /*
@@ -146,7 +219,13 @@ BOOL change_to_user(connection_struct *conn, uint16 vuid)
         */
 
        if((group_c = *lp_force_group(snum))) {
-               BOOL is_guest = False;
+
+               token = dup_nt_token(NULL, token);
+               if (token == NULL) {
+                       DEBUG(0, ("dup_nt_token failed\n"));
+                       return False;
+               }
+               must_free_token = True;
 
                if(group_c == '+') {
 
@@ -158,36 +237,34 @@ BOOL change_to_user(connection_struct *conn, uint16 vuid)
                         */
 
                        int i;
-                       for (i = 0; i < current_user.ngroups; i++) {
-                               if (current_user.groups[i] == conn->gid) {
+                       for (i = 0; i < num_groups; i++) {
+                               if (group_list[i] == conn->gid) {
                                        gid = conn->gid;
+                                       gid_to_sid(&token->user_sids[1], gid);
                                        break;
                                }
                        }
                } else {
                        gid = conn->gid;
+                       gid_to_sid(&token->user_sids[1], gid);
                }
-
-               /*
-                * We've changed the group list in the token - we must
-                * re-create it.
-                */
-
-               if (vuser && vuser->guest)
-                       is_guest = True;
-
-               token = create_nt_token(uid, gid, current_user.ngroups, current_user.groups, is_guest, NULL);
-               must_free_token = True;
        }
        
-       set_sec_ctx(uid, gid, current_user.ngroups, current_user.groups, token);
+       /* Now set current_user since we will immediately also call
+          set_sec_ctx() */
+
+       current_user.ut.ngroups = num_groups;
+       current_user.ut.groups  = group_list;   
+
+       set_sec_ctx(uid, gid, current_user.ut.ngroups, current_user.ut.groups,
+                   token);
 
        /*
         * Free the new token (as set_sec_ctx copies it).
         */
 
        if (must_free_token)
-               delete_nt_token(&token);
+               TALLOC_FREE(token);
 
        current_user.conn = conn;
        current_user.vuid = vuid;
@@ -227,8 +304,9 @@ BOOL become_authenticated_pipe_user(pipes_struct *p)
        if (!push_sec_ctx())
                return False;
 
-       set_sec_ctx(p->pipe_user.uid, p->pipe_user.gid, 
-                   p->pipe_user.ngroups, p->pipe_user.groups, p->pipe_user.nt_user_token);
+       set_sec_ctx(p->pipe_user.ut.uid, p->pipe_user.ut.gid, 
+                   p->pipe_user.ut.ngroups, p->pipe_user.ut.groups,
+                   p->pipe_user.nt_user_token);
 
        return True;
 }
@@ -303,17 +381,6 @@ static void pop_conn_ctx(void)
        ctx_p->vuid = UID_FIELD_INVALID;
 }
 
-void init_conn_ctx(void)
-{
-    int i;
-    /* Initialise connection context stack */
-       for (i = 0; i < MAX_SEC_CTX_DEPTH; i++) {
-               conn_ctx_stack[i].conn = NULL;
-               conn_ctx_stack[i].vuid = UID_FIELD_INVALID;
-    }
-}
-
 /****************************************************************************
  Temporarily become a root user.  Must match with unbecome_root(). Saves and
  restores the connection context.
@@ -361,337 +428,3 @@ BOOL unbecome_user(void)
        pop_conn_ctx();
        return True;
 }
-
-/*****************************************************************
- Convert the suplimentary SIDs returned in a netlogon into UNIX
- group gid_t's. Add to the total group array.
-*****************************************************************/
-void add_supplementary_nt_login_groups(int *n_groups, gid_t **pp_groups, NT_USER_TOKEN **pptok)
-{
-       int total_groups;
-       int current_n_groups = *n_groups;
-       gid_t *final_groups = NULL;
-       size_t i;
-       NT_USER_TOKEN *ptok = *pptok;
-       NT_USER_TOKEN *new_tok = NULL;
-       if (!ptok || (ptok->num_sids == 0))
-               return;
-
-       new_tok = dup_nt_token(ptok);
-       if (!new_tok) {
-               DEBUG(0,("add_supplementary_nt_login_groups: Failed to malloc new token\n"));
-               return;
-       }
-       /* Leave the allocated space but empty the number of SIDs. */
-       new_tok->num_sids = 0;
-
-       total_groups = current_n_groups + ptok->num_sids;
-       final_groups = (gid_t *)malloc(total_groups * sizeof(gid_t));
-       if (!final_groups) {
-               DEBUG(0,("add_supplementary_nt_login_groups: Failed to malloc new groups.\n"));
-               delete_nt_token(&new_tok);
-               return;
-       }
-       memcpy(final_groups, *pp_groups, current_n_groups * sizeof(gid_t));
-       for (i = 0; i < ptok->num_sids; i++) {
-               enum SID_NAME_USE sid_type;
-               gid_t new_grp;
-               if (sid_to_gid(&ptok->user_sids[i], &new_grp, &sid_type)) {
-                       /*
-                        * Don't add the gid_t if it is already in the current group
-                        * list. Some UNIXen don't like the same group more than once.
-                        */
-                       int j;
-
-                       for (j = 0; j < current_n_groups; j++)
-                               if (final_groups[j] == new_grp)
-                                       break;
-               
-                       if ( j == current_n_groups) {
-                               /* Group not already present. */
-                               final_groups[current_n_groups++] = new_grp;
-                       }
-               } else {
-                       /* SID didn't map. Copy to the new token to be saved. */
-                       sid_copy(&new_tok->user_sids[new_tok->num_sids++], &ptok->user_sids[i]);
-               }
-       }
-       SAFE_FREE(*pp_groups);
-       *pp_groups = final_groups;
-       *n_groups = current_n_groups;
-
-       /* Replace the old token with the truncated one. */
-       delete_nt_token(&ptok);
-       *pptok = new_tok;
-}
-
-/*****************************************************************
- *THE CANONICAL* convert name to SID function.
- Tries winbind first - then uses local lookup.
-*****************************************************************/  
-
-BOOL lookup_name(const char *domain, const char *name, DOM_SID *psid, enum SID_NAME_USE *name_type)
-{
-       extern pstring global_myname;
-       extern fstring global_myworkgroup;
-       fstring sid;
-       
-       *name_type = SID_NAME_UNKNOWN;
-
-       if (!winbind_lookup_name(domain, name, psid, name_type) || (*name_type != SID_NAME_USER) ) {
-               BOOL ret = False;
-
-               DEBUG(10, ("lookup_name: winbind lookup for [%s]\\[%s] failed - trying local\n", domain, name));
-
-               /* If we are looking up a domain user, make sure it is
-                  for the local machine only */
-               
-               switch (lp_server_role()) {
-               case ROLE_DOMAIN_PDC:
-               case ROLE_DOMAIN_BDC:
-                       if (strequal(domain, global_myworkgroup)) {
-                               ret = local_lookup_name(name, psid, name_type);
-                       }
-                       /* No break is deliberate here. JRA. */
-               default:
-                       if (ret) {
-                       } else if (strequal(global_myname, domain)) {
-                               ret = local_lookup_name(name, psid, name_type);
-                       } else {
-                               DEBUG(5, ("lookup_name: domain %s is not local\n", domain));
-                       }
-               }
-
-               if (ret) {
-                       DEBUG(10,
-                             ("lookup_name: (local) [%s]\\[%s] -> SID %s (type %u)\n",
-                              domain, name, sid_to_string(sid,psid),
-                              (unsigned int)*name_type ));
-               } else {
-                       DEBUG(10,("lookup name: (local) [%s]\\[%s] failed.\n", domain, name));
-               }
-
-               return ret;
-       }
-
-       DEBUG(10,("lookup_name (winbindd): [%s]\\[%s] -> SID %s (type %u)\n",
-                 domain, name, sid_to_string(sid, psid), 
-                 (unsigned int)*name_type));
-       return True;
-}
-
-/*****************************************************************
- *THE CANONICAL* convert SID to name function.
- Tries winbind first - then uses local lookup.
-*****************************************************************/  
-
-BOOL lookup_sid(DOM_SID *sid, fstring dom_name, fstring name, enum SID_NAME_USE *name_type)
-{
-       if (!name_type)
-               return False;
-
-       *name_type = SID_NAME_UNKNOWN;
-
-       /* Check if this is our own sid.  This should perhaps be done by
-          winbind?  For the moment handle it here. */
-
-       if (sid->num_auths == 5) {
-               DOM_SID tmp_sid;
-               uint32 rid;
-
-               sid_copy(&tmp_sid, sid);
-               sid_split_rid(&tmp_sid, &rid);
-
-               if (sid_equal(&global_sam_sid, &tmp_sid)) {
-
-                       return map_domain_sid_to_name(&tmp_sid, dom_name) &&
-                               local_lookup_sid(sid, name, name_type);
-               }
-       }
-
-       if (!winbind_lookup_sid(sid, dom_name, name, name_type)) {
-               fstring sid_str;
-               DOM_SID tmp_sid;
-               uint32 rid;
-
-               DEBUG(10,("lookup_sid: winbind lookup for SID %s failed - trying local.\n", sid_to_string(sid_str, sid) ));
-
-               sid_copy(&tmp_sid, sid);
-               sid_split_rid(&tmp_sid, &rid);
-               return map_domain_sid_to_name(&tmp_sid, dom_name) &&
-                               lookup_known_rid(&tmp_sid, rid, name, name_type);
-       }
-       return True;
-}
-
-/*****************************************************************
- *THE CANONICAL* convert uid_t to SID function.
- Tries winbind first - then uses local lookup.
- Returns SID pointer.
-*****************************************************************/  
-
-DOM_SID *uid_to_sid(DOM_SID *psid, uid_t uid)
-{
-       uid_t low, high;
-       fstring sid;
-
-       if (lp_winbind_uid(&low, &high) && uid >= low && uid <= high) {
-               if (winbind_uid_to_sid(psid, uid)) {
-
-                       DEBUG(10,("uid_to_sid: winbindd %u -> %s\n",
-                               (unsigned int)uid, sid_to_string(sid, psid)));
-
-                       return psid;
-               }
-       }
-
-       local_uid_to_sid(psid, uid);
-        
-       DEBUG(10,("uid_to_sid: local %u -> %s\n", (unsigned int)uid, sid_to_string(sid, psid)));
-
-       return psid;
-}
-
-/*****************************************************************
- *THE CANONICAL* convert gid_t to SID function.
- Tries winbind first - then uses local lookup.
- Returns SID pointer.
-*****************************************************************/  
-
-DOM_SID *gid_to_sid(DOM_SID *psid, gid_t gid)
-{
-       gid_t low, high;
-       fstring sid;
-
-       if (lp_winbind_gid(&low, &high) && gid >= low && gid <= high) {
-               if (winbind_gid_to_sid(psid, gid)) {
-
-                       DEBUG(10,("gid_to_sid: winbindd %u -> %s\n",
-                               (unsigned int)gid, sid_to_string(sid, psid)));
-                        
-                       return psid;
-               }
-       }
-
-       local_gid_to_sid(psid, gid);
-        
-       DEBUG(10,("gid_to_sid: local %u -> %s\n", (unsigned int)gid, sid_to_string(sid, psid)));
-
-       return psid;
-}
-
-/*****************************************************************
- *THE CANONICAL* convert SID to uid function.
- Tries winbind first - then uses local lookup.
- Returns True if this name is a user sid and the conversion
- was done correctly, False if not. sidtype is set by this function.
-*****************************************************************/  
-
-BOOL sid_to_uid(DOM_SID *psid, uid_t *puid, enum SID_NAME_USE *sidtype)
-{
-       fstring dom_name, name, sid_str;
-       enum SID_NAME_USE name_type;
-
-       *sidtype = SID_NAME_UNKNOWN;
-
-       /*
-        * First we must look up the name and decide if this is a user sid.
-        */
-
-       if ( (!winbind_lookup_sid(psid, dom_name, name, &name_type)) || (name_type != SID_NAME_USER) ) {
-               DEBUG(10,("sid_to_uid: winbind lookup for sid %s failed - trying local.\n",
-                               sid_to_string(sid_str, psid) ));
-
-               return local_sid_to_uid(puid, psid, sidtype);
-       }
-
-       /*
-        * Ensure this is a user sid.
-        */
-
-       if (name_type != SID_NAME_USER) {
-               DEBUG(10,("sid_to_uid: winbind lookup succeeded but SID is not a uid (%u)\n",
-                               (unsigned int)name_type ));
-               return False;
-       }
-
-       *sidtype = SID_NAME_USER;
-
-       /*
-        * Get the uid for this SID.
-        */
-
-       if (!winbind_sid_to_uid(puid, psid)) {
-               DEBUG(10,("sid_to_uid: winbind lookup for sid %s failed.\n",
-                               sid_to_string(sid_str, psid) ));
-               return False;
-       }
-
-       DEBUG(10,("sid_to_uid: winbindd %s -> %u\n",
-               sid_to_string(sid_str, psid),
-               (unsigned int)*puid ));
-
-       return True;
-}
-
-/*****************************************************************
- *THE CANONICAL* convert SID to gid function.
- Tries winbind first - then uses local lookup.
- Returns True if this name is a user sid and the conversion
- was done correctly, False if not.
-*****************************************************************/  
-
-BOOL sid_to_gid(DOM_SID *psid, gid_t *pgid, enum SID_NAME_USE *sidtype)
-{
-       fstring dom_name, name, sid_str;
-       enum SID_NAME_USE name_type;
-
-       *sidtype = SID_NAME_UNKNOWN;
-
-       /*
-        * First we must look up the name and decide if this is a group sid.
-        */
-
-       if (!winbind_lookup_sid(psid, dom_name, name, &name_type)) {
-               DEBUG(10,("sid_to_gid: winbind lookup for sid %s failed - trying local.\n",
-                               sid_to_string(sid_str, psid) ));
-
-               return local_sid_to_gid(pgid, psid, sidtype);
-       }
-
-       /*
-        * Ensure this is a group sid.
-        */
-
-       if ((name_type != SID_NAME_DOM_GRP) && (name_type != SID_NAME_ALIAS) && (name_type != SID_NAME_WKN_GRP)) {
-               DEBUG(10,("sid_to_gid: winbind lookup succeeded but SID is not a known group (%u)\n",
-                               (unsigned int)name_type ));
-
-               return local_sid_to_gid(pgid, psid, sidtype);
-       }
-
-       *sidtype = name_type;
-
-       /*
-        * Get the gid for this SID.
-        */
-
-       if (!winbind_sid_to_gid(pgid, psid)) {
-               DEBUG(10,("sid_to_gid: winbind lookup for sid %s failed.\n",
-                               sid_to_string(sid_str, psid) ));
-               return False;
-       }
-
-       DEBUG(10,("sid_to_gid: winbindd %s -> %u\n",
-               sid_to_string(sid_str, psid),
-               (unsigned int)*pgid ));
-
-       return True;
-}
-