empty access mask is only denied on SMB2
[kai/samba.git] / source4 / ntvfs / posix / pvfs_acl.c
index 3826b2f157cb964aa369b6e7d098a4cc20c4bd10..d479f1e2ee0e452ec48243d3a6db4ec7d9e14a68 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"
 #include "vfs_posix.h"
 #include "librpc/gen_ndr/xattr.h"
 #include "libcli/security/security.h"
+#include "param/param.h"
+
+
+/* the list of currently registered ACL backends */
+static struct pvfs_acl_backend {
+       const struct pvfs_acl_ops *ops;
+} *backends = NULL;
+static int num_backends;
+
+/*
+  register a pvfs acl backend. 
+
+  The 'name' can be later used by other backends to find the operations
+  structure for this backend.  
+*/
+NTSTATUS pvfs_acl_register(const struct pvfs_acl_ops *ops)
+{
+       struct pvfs_acl_ops *new_ops;
+
+       if (pvfs_acl_backend_byname(ops->name) != NULL) {
+               DEBUG(0,("pvfs acl backend '%s' already registered\n", ops->name));
+               return NT_STATUS_OBJECT_NAME_COLLISION;
+       }
+
+       backends = talloc_realloc(talloc_autofree_context(), backends, struct pvfs_acl_backend, num_backends+1);
+       NT_STATUS_HAVE_NO_MEMORY(backends);
+
+       new_ops = talloc_memdup(backends, ops, sizeof(*ops));
+       new_ops->name = talloc_strdup(new_ops, ops->name);
+
+       backends[num_backends].ops = new_ops;
+
+       num_backends++;
+
+       DEBUG(3,("NTVFS backend '%s' registered\n", ops->name));
+
+       return NT_STATUS_OK;
+}
+
+
+/*
+  return the operations structure for a named backend
+*/
+const struct pvfs_acl_ops *pvfs_acl_backend_byname(const char *name)
+{
+       int i;
+
+       for (i=0;i<num_backends;i++) {
+               if (strcmp(backends[i].ops->name, name) == 0) {
+                       return backends[i].ops;
+               }
+       }
+
+       return NULL;
+}
+
+NTSTATUS pvfs_acl_init(struct loadparm_context *lp_ctx)
+{
+       static bool initialized = false;
+       extern NTSTATUS pvfs_acl_nfs4_init(void);
+       extern NTSTATUS pvfs_acl_xattr_init(void);
+       init_module_fn static_init[] = { STATIC_pvfs_acl_MODULES };
+       init_module_fn *shared_init;
+
+       if (initialized) return NT_STATUS_OK;
+       initialized = true;
+
+       shared_init = load_samba_modules(NULL, lp_ctx, "pvfs_acl");
+
+       run_init_functions(static_init);
+       run_init_functions(shared_init);
+
+       talloc_free(shared_init);
+
+       return NT_STATUS_OK;
+}
 
 
 /*
@@ -67,27 +142,48 @@ static void pvfs_translate_generic_bits(struct security_acl *acl)
 static NTSTATUS pvfs_default_acl(struct pvfs_state *pvfs,
                                 struct ntvfs_request *req,
                                 struct pvfs_filename *name, int fd, 
-                                struct xattr_NTACL *acl)
+                                struct security_descriptor **psd)
 {
        struct security_descriptor *sd;
        NTSTATUS status;
        struct security_ace ace;
        mode_t mode;
+       struct id_mapping *ids;
+       struct composite_context *ctx;
 
-       sd = security_descriptor_initialise(req);
-       if (sd == NULL) {
+       *psd = security_descriptor_initialise(req);
+       if (*psd == NULL) {
                return NT_STATUS_NO_MEMORY;
        }
+       sd = *psd;
 
-       status = sidmap_uid_to_sid(pvfs->sidmap, sd, name->st.st_uid, &sd->owner_sid);
-       if (!NT_STATUS_IS_OK(status)) {
-               return status;
-       }
-       status = sidmap_gid_to_sid(pvfs->sidmap, sd, name->st.st_gid, &sd->group_sid);
-       if (!NT_STATUS_IS_OK(status)) {
-               return status;
-       }
+       ids = talloc_zero_array(sd, struct id_mapping, 2);
+       NT_STATUS_HAVE_NO_MEMORY(ids);
+
+       ids[0].unixid = talloc(ids, struct unixid);
+       NT_STATUS_HAVE_NO_MEMORY(ids[0].unixid);
 
+       ids[0].unixid->id = name->st.st_uid;
+       ids[0].unixid->type = ID_TYPE_UID;
+       ids[0].sid = NULL;
+
+       ids[1].unixid = talloc(ids, struct unixid);
+       NT_STATUS_HAVE_NO_MEMORY(ids[1].unixid);
+
+       ids[1].unixid->id = name->st.st_gid;
+       ids[1].unixid->type = ID_TYPE_GID;
+       ids[1].sid = NULL;
+
+       ctx = wbc_xids_to_sids_send(pvfs->wbc_ctx, ids, 2, ids);
+       NT_STATUS_HAVE_NO_MEMORY(ctx);
+
+       status = wbc_xids_to_sids_recv(ctx, &ids);
+       NT_STATUS_NOT_OK_RETURN(status);
+
+       sd->owner_sid = talloc_steal(sd, ids[0].sid);
+       sd->group_sid = talloc_steal(sd, ids[1].sid);
+
+       talloc_free(ids);
        sd->type |= SEC_DESC_DACL_PRESENT;
 
        mode = name->st.st_mode;
@@ -154,9 +250,6 @@ static NTSTATUS pvfs_default_acl(struct pvfs_state *pvfs,
        ace.access_mask = SEC_RIGHTS_FILE_ALL;
        security_descriptor_dacl_add(sd, &ace);
        
-       acl->version = 1;
-       acl->info.sd = sd;
-
        return NT_STATUS_OK;
 }
                                 
@@ -190,35 +283,31 @@ NTSTATUS pvfs_acl_set(struct pvfs_state *pvfs,
                      uint32_t access_mask,
                      union smb_setfileinfo *info)
 {
-       struct xattr_NTACL *acl;
        uint32_t secinfo_flags = info->set_secdesc.in.secinfo_flags;
        struct security_descriptor *new_sd, *sd, orig_sd;
-       NTSTATUS status;
+       NTSTATUS status = NT_STATUS_NOT_FOUND;
        uid_t old_uid = -1;
        gid_t old_gid = -1;
        uid_t new_uid = -1;
        gid_t new_gid = -1;
+       struct id_mapping *ids;
+       struct composite_context *ctx;
 
-       acl = talloc(req, struct xattr_NTACL);
-       if (acl == NULL) {
-               return NT_STATUS_NO_MEMORY;
+       if (pvfs->acl_ops != NULL) {
+               status = pvfs->acl_ops->acl_load(pvfs, name, fd, req, &sd);
        }
-
-       status = pvfs_acl_load(pvfs, name, fd, acl);
        if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
-               status = pvfs_default_acl(pvfs, req, name, fd, acl);
+               status = pvfs_default_acl(pvfs, req, name, fd, &sd);
        }
        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }
 
-       switch (acl->version) {
-       case 1:
-               sd = acl->info.sd;
-               break;
-       default:
-               return NT_STATUS_INVALID_ACL;
-       }
+       ids = talloc(req, struct id_mapping);
+       NT_STATUS_HAVE_NO_MEMORY(ids);
+       ids->unixid = NULL;
+       ids->sid = NULL;
+       ids->status = NT_STATUS_NONE_MAPPED;
 
        new_sd = info->set_secdesc.in.sd;
        orig_sd = *sd;
@@ -232,8 +321,16 @@ NTSTATUS pvfs_acl_set(struct pvfs_state *pvfs,
                        return NT_STATUS_ACCESS_DENIED;
                }
                if (!dom_sid_equal(sd->owner_sid, new_sd->owner_sid)) {
-                       status = sidmap_sid_to_unixuid(pvfs->sidmap, new_sd->owner_sid, &new_uid);
+                       ids->sid = new_sd->owner_sid;
+                       ctx = wbc_sids_to_xids_send(pvfs->wbc_ctx, ids, 1, ids);
+                       NT_STATUS_HAVE_NO_MEMORY(ctx);
+                       status = wbc_sids_to_xids_recv(ctx, &ids);
                        NT_STATUS_NOT_OK_RETURN(status);
+
+                       if (ids->unixid->type == ID_TYPE_BOTH ||
+                           ids->unixid->type == ID_TYPE_UID) {
+                               new_uid = ids->unixid->id;
+                       }
                }
                sd->owner_sid = new_sd->owner_sid;
        }
@@ -242,8 +339,17 @@ NTSTATUS pvfs_acl_set(struct pvfs_state *pvfs,
                        return NT_STATUS_ACCESS_DENIED;
                }
                if (!dom_sid_equal(sd->group_sid, new_sd->group_sid)) {
-                       status = sidmap_sid_to_unixgid(pvfs->sidmap, new_sd->group_sid, &new_gid);
+                       ids->sid = new_sd->group_sid;
+                       ctx = wbc_sids_to_xids_send(pvfs->wbc_ctx, ids, 1, ids);
+                       NT_STATUS_HAVE_NO_MEMORY(ctx);
+                       status = wbc_sids_to_xids_recv(ctx, &ids);
                        NT_STATUS_NOT_OK_RETURN(status);
+
+                       if (ids->unixid->type == ID_TYPE_BOTH ||
+                           ids->unixid->type == ID_TYPE_GID) {
+                               new_gid = ids->unixid->id;
+                       }
+
                }
                sd->group_sid = new_sd->group_sid;
        }
@@ -286,8 +392,8 @@ NTSTATUS pvfs_acl_set(struct pvfs_state *pvfs,
        /* we avoid saving if the sd is the same. This means when clients
           copy files and end up copying the default sd that we don't
           needlessly use xattrs */
-       if (!security_descriptor_equal(sd, &orig_sd)) {
-               status = pvfs_acl_save(pvfs, name, fd, acl);
+       if (!security_descriptor_equal(sd, &orig_sd) && pvfs->acl_ops) {
+               status = pvfs->acl_ops->acl_save(pvfs, name, fd, sd);
        }
 
        return status;
@@ -302,31 +408,19 @@ NTSTATUS pvfs_acl_query(struct pvfs_state *pvfs,
                        struct pvfs_filename *name, int fd, 
                        union smb_fileinfo *info)
 {
-       struct xattr_NTACL *acl;
-       NTSTATUS status;
+       NTSTATUS status = NT_STATUS_NOT_FOUND;
        struct security_descriptor *sd;
 
-       acl = talloc(req, struct xattr_NTACL);
-       if (acl == NULL) {
-               return NT_STATUS_NO_MEMORY;
+       if (pvfs->acl_ops) {
+               status = pvfs->acl_ops->acl_load(pvfs, name, fd, req, &sd);
        }
-
-       status = pvfs_acl_load(pvfs, name, fd, acl);
        if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
-               status = pvfs_default_acl(pvfs, req, name, fd, acl);
+               status = pvfs_default_acl(pvfs, req, name, fd, &sd);
        }
        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }
 
-       switch (acl->version) {
-       case 1:
-               sd = acl->info.sd;
-               break;
-       default:
-               return NT_STATUS_INVALID_ACL;
-       }
-
        normalise_sd_flags(sd, info->query_secdesc.in.secinfo_flags);
 
        info->query_secdesc.out.sd = sd;
@@ -335,6 +429,25 @@ NTSTATUS pvfs_acl_query(struct pvfs_state *pvfs,
 }
 
 
+/*
+  check the read only bit against any of the write access bits
+*/
+static bool pvfs_read_only(struct pvfs_state *pvfs, uint32_t access_mask)
+{
+       if ((pvfs->flags & PVFS_FLAG_READONLY) &&
+           (access_mask & (SEC_FILE_WRITE_DATA |
+                           SEC_FILE_APPEND_DATA | 
+                           SEC_FILE_WRITE_EA | 
+                           SEC_FILE_WRITE_ATTRIBUTE | 
+                           SEC_STD_DELETE | 
+                           SEC_STD_WRITE_DAC | 
+                           SEC_STD_WRITE_OWNER | 
+                           SEC_DIR_DELETE_CHILD))) {
+               return true;
+       }
+       return false;
+}
+
 /*
   default access check function based on unix permissions
   doing this saves on building a full security descriptor
@@ -349,8 +462,14 @@ NTSTATUS pvfs_access_check_unix(struct pvfs_state *pvfs,
        uid_t uid = geteuid();
        uint32_t max_bits = SEC_RIGHTS_FILE_READ | SEC_FILE_ALL;
 
+       if (pvfs_read_only(pvfs, *access_mask)) {
+               return NT_STATUS_ACCESS_DENIED;
+       }
+
        /* owner and root get extra permissions */
-       if (uid == 0 || uid == name->st.st_uid) {
+       if (uid == 0) {
+               max_bits |= SEC_STD_ALL | SEC_FLAG_SYSTEM_SECURITY;
+       } else if (uid == name->st.st_uid) {
                max_bits |= SEC_STD_ALL;
        }
 
@@ -359,11 +478,19 @@ NTSTATUS pvfs_access_check_unix(struct pvfs_state *pvfs,
                return NT_STATUS_OK;
        }
 
+       if (uid != 0 && (*access_mask & SEC_FLAG_SYSTEM_SECURITY)) {
+               return NT_STATUS_ACCESS_DENIED;
+       }
+
        if (*access_mask & ~max_bits) {
                return NT_STATUS_ACCESS_DENIED;
        }
 
-       *access_mask |= SEC_FILE_READ_ATTRIBUTE;
+       if (pvfs->ntvfs->ctx->protocol != PROTOCOL_SMB2) {
+               /* on SMB, this bit is always granted, even if not
+                  asked for */
+               *access_mask |= SEC_FILE_READ_ATTRIBUTE;
+       }
 
        return NT_STATUS_OK;
 }
@@ -384,6 +511,16 @@ NTSTATUS pvfs_access_check(struct pvfs_state *pvfs,
        NTSTATUS status;
        struct security_descriptor *sd;
 
+       /* on SMB2 a blank access mask is always denied */
+       if (pvfs->ntvfs->ctx->protocol == PROTOCOL_SMB2 &&
+           *access_mask == 0) {
+               return NT_STATUS_ACCESS_DENIED;
+       }
+
+       if (pvfs_read_only(pvfs, *access_mask)) {
+               return NT_STATUS_ACCESS_DENIED;
+       }
+
        acl = talloc(req, struct xattr_NTACL);
        if (acl == NULL) {
                return NT_STATUS_NO_MEMORY;
@@ -391,7 +528,9 @@ NTSTATUS pvfs_access_check(struct pvfs_state *pvfs,
 
        /* expand the generic access bits to file specific bits */
        *access_mask = pvfs_translate_mask(*access_mask);
-       *access_mask &= ~SEC_FILE_READ_ATTRIBUTE;
+       if (pvfs->ntvfs->ctx->protocol != PROTOCOL_SMB2) {
+               *access_mask &= ~SEC_FILE_READ_ATTRIBUTE;
+       }
 
        status = pvfs_acl_load(pvfs, name, -1, acl);
        if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
@@ -413,8 +552,11 @@ NTSTATUS pvfs_access_check(struct pvfs_state *pvfs,
        /* check the acl against the required access mask */
        status = sec_access_check(sd, token, *access_mask, access_mask);
 
-       /* this bit is always granted, even if not asked for */
-       *access_mask |= SEC_FILE_READ_ATTRIBUTE;
+       if (pvfs->ntvfs->ctx->protocol != PROTOCOL_SMB2) {
+               /* on SMB, this bit is always granted, even if not
+                  asked for */
+               *access_mask |= SEC_FILE_READ_ATTRIBUTE;
+       }
 
        talloc_free(acl);
        
@@ -488,24 +630,24 @@ NTSTATUS pvfs_access_check_parent(struct pvfs_state *pvfs,
 /*
   determine if an ACE is inheritable
 */
-static BOOL pvfs_inheritable_ace(struct pvfs_state *pvfs,
+static bool pvfs_inheritable_ace(struct pvfs_state *pvfs,
                                 const struct security_ace *ace,
-                                BOOL container)
+                                bool container)
 {
        if (!container) {
                return (ace->flags & SEC_ACE_FLAG_OBJECT_INHERIT) != 0;
        }
 
        if (ace->flags & SEC_ACE_FLAG_CONTAINER_INHERIT) {
-               return True;
+               return true;
        }
 
        if ((ace->flags & SEC_ACE_FLAG_OBJECT_INHERIT) &&
            !(ace->flags & SEC_ACE_FLAG_NO_PROPAGATE_INHERIT)) {
-               return True;
+               return true;
        }
 
-       return False;
+       return false;
 }
 
 /*
@@ -516,7 +658,7 @@ static BOOL pvfs_inheritable_ace(struct pvfs_state *pvfs,
 static NTSTATUS pvfs_acl_inherit_aces(struct pvfs_state *pvfs, 
                                      struct security_descriptor *parent_sd,
                                      struct security_descriptor *sd,
-                                     BOOL container)
+                                     bool container)
 {
        int i;
        
@@ -603,7 +745,9 @@ NTSTATUS pvfs_acl_inherit(struct pvfs_state *pvfs,
        NTSTATUS status;
        struct pvfs_filename *parent;
        struct security_descriptor *parent_sd, *sd;
-       BOOL container;
+       bool container;
+       struct id_mapping *ids;
+       struct composite_context *ctx;
 
        /* form the parents path */
        status = pvfs_resolve_parent(pvfs, req, name, &parent);
@@ -645,18 +789,35 @@ NTSTATUS pvfs_acl_inherit(struct pvfs_state *pvfs,
                return NT_STATUS_NO_MEMORY;
        }
 
-       status = sidmap_uid_to_sid(pvfs->sidmap, sd, name->st.st_uid, &sd->owner_sid);
-       if (!NT_STATUS_IS_OK(status)) {
-               return status;
-       }
-       status = sidmap_gid_to_sid(pvfs->sidmap, sd, name->st.st_gid, &sd->group_sid);
-       if (!NT_STATUS_IS_OK(status)) {
-               return status;
-       }
+       ids = talloc_array(sd, struct id_mapping, 2);
+       NT_STATUS_HAVE_NO_MEMORY(ids);
+
+       ids[0].unixid = talloc(ids, struct unixid);
+       NT_STATUS_HAVE_NO_MEMORY(ids[0].unixid);
+       ids[0].unixid->id = name->st.st_uid;
+       ids[0].unixid->type = ID_TYPE_UID;
+       ids[0].sid = NULL;
+       ids[0].status = NT_STATUS_NONE_MAPPED;
+
+       ids[1].unixid = talloc(ids, struct unixid);
+       NT_STATUS_HAVE_NO_MEMORY(ids[1].unixid);
+       ids[1].unixid->id = name->st.st_gid;
+       ids[1].unixid->type = ID_TYPE_GID;
+       ids[1].sid = NULL;
+       ids[1].status = NT_STATUS_NONE_MAPPED;
+
+       ctx = wbc_xids_to_sids_send(pvfs->wbc_ctx, ids, 2, ids);
+       NT_STATUS_HAVE_NO_MEMORY(ctx);
+
+       status = wbc_xids_to_sids_recv(ctx, &ids);
+       NT_STATUS_NOT_OK_RETURN(status);
+
+       sd->owner_sid = talloc_steal(sd, ids[0].sid);
+       sd->group_sid = talloc_steal(sd, ids[1].sid);
 
        sd->type |= SEC_DESC_DACL_PRESENT;
 
-       container = (name->dos.attrib & FILE_ATTRIBUTE_DIRECTORY) ? True:False;
+       container = (name->dos.attrib & FILE_ATTRIBUTE_DIRECTORY) ? true:false;
 
        /* fill in the aces from the parent */
        status = pvfs_acl_inherit_aces(pvfs, parent_sd, sd, container);
@@ -676,3 +837,15 @@ NTSTATUS pvfs_acl_inherit(struct pvfs_state *pvfs,
        
        return status;
 }
+
+/*
+  return the maximum allowed access mask
+*/
+NTSTATUS pvfs_access_maximal_allowed(struct pvfs_state *pvfs, 
+                                    struct ntvfs_request *req,
+                                    struct pvfs_filename *name,
+                                    uint32_t *maximal_access)
+{
+       *maximal_access = SEC_FLAG_MAXIMUM_ALLOWED;
+       return pvfs_access_check(pvfs, req, name, maximal_access);
+}