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-rw-r--r--source3/modules/posixacl_xattr.c423
1 files changed, 423 insertions, 0 deletions
diff --git a/source3/modules/posixacl_xattr.c b/source3/modules/posixacl_xattr.c
new file mode 100644
index 0000000..365cdc7
--- /dev/null
+++ b/source3/modules/posixacl_xattr.c
@@ -0,0 +1,423 @@
+/*
+ Unix SMB/Netbios implementation.
+ VFS module to get and set posix acls through xattr
+ Copyright (c) 2013 Anand Avati <avati@redhat.com>
+ Copyright (c) 2016 Yan, Zheng <zyan@redhat.com>
+
+ 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 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ 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, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "includes.h"
+#include "system/filesys.h"
+#include "smbd/smbd.h"
+#include "modules/posixacl_xattr.h"
+
+/*
+ POSIX ACL Format:
+
+ Size = 4 (header) + N * 8 (entry)
+
+ Offset Size Field (Little Endian)
+ -------------------------------------
+ 0-3 4-byte Version
+
+ 4-5 2-byte Entry-1 tag
+ 6-7 2-byte Entry-1 perm
+ 8-11 4-byte Entry-1 id
+
+ 12-13 2-byte Entry-2 tag
+ 14-15 2-byte Entry-2 perm
+ 16-19 4-byte Entry-2 id
+
+ ...
+
+ */
+
+
+
+/* private functions */
+
+#define ACL_EA_ACCESS "system.posix_acl_access"
+#define ACL_EA_DEFAULT "system.posix_acl_default"
+#define ACL_EA_VERSION 0x0002
+#define ACL_EA_HEADER_SIZE 4
+#define ACL_EA_ENTRY_SIZE 8
+
+#define ACL_EA_SIZE(n) (ACL_EA_HEADER_SIZE + ((n) * ACL_EA_ENTRY_SIZE))
+
+static SMB_ACL_T mode_to_smb_acl(mode_t mode, TALLOC_CTX *mem_ctx)
+{
+ struct smb_acl_t *result;
+ int count;
+
+ count = 3;
+ result = sys_acl_init(mem_ctx);
+ if (!result) {
+ return NULL;
+ }
+
+ result->acl = talloc_array(result, struct smb_acl_entry, count);
+ if (!result->acl) {
+ errno = ENOMEM;
+ talloc_free(result);
+ return NULL;
+ }
+
+ result->count = count;
+
+ result->acl[0].a_type = SMB_ACL_USER_OBJ;
+ result->acl[0].a_perm = (mode & S_IRWXU) >> 6;
+
+ result->acl[1].a_type = SMB_ACL_GROUP_OBJ;
+ result->acl[1].a_perm = (mode & S_IRWXG) >> 3;
+
+ result->acl[2].a_type = SMB_ACL_OTHER;
+ result->acl[2].a_perm = mode & S_IRWXO;
+
+ return result;
+}
+
+static SMB_ACL_T posixacl_xattr_to_smb_acl(const char *buf, size_t xattr_size,
+ TALLOC_CTX *mem_ctx)
+{
+ int count;
+ int size;
+ struct smb_acl_entry *smb_ace;
+ struct smb_acl_t *result;
+ int i;
+ int offset;
+ uint16_t tag;
+ uint16_t perm;
+ uint32_t id;
+
+ size = xattr_size;
+
+ if (size < ACL_EA_HEADER_SIZE) {
+ /* ACL should be at least as big as the header (4 bytes) */
+ errno = EINVAL;
+ return NULL;
+ }
+
+ /* Version is the first 4 bytes of the ACL */
+ if (IVAL(buf, 0) != ACL_EA_VERSION) {
+ DEBUG(0, ("Unknown ACL EA version: %d\n",
+ IVAL(buf, 0)));
+ errno = EINVAL;
+ return NULL;
+ }
+ offset = ACL_EA_HEADER_SIZE;
+
+ size -= ACL_EA_HEADER_SIZE;
+ if (size % ACL_EA_ENTRY_SIZE) {
+ /* Size of entries must strictly be a multiple of
+ size of an ACE (8 bytes)
+ */
+ DEBUG(0, ("Invalid ACL EA size: %d\n", size));
+ errno = EINVAL;
+ return NULL;
+ }
+
+ count = size / ACL_EA_ENTRY_SIZE;
+
+ result = sys_acl_init(mem_ctx);
+ if (!result) {
+ return NULL;
+ }
+
+ result->acl = talloc_array(result, struct smb_acl_entry, count);
+ if (!result->acl) {
+ errno = ENOMEM;
+ talloc_free(result);
+ return NULL;
+ }
+
+ result->count = count;
+
+ smb_ace = result->acl;
+
+ for (i = 0; i < count; i++) {
+ /* TAG is the first 2 bytes of an entry */
+ tag = SVAL(buf, offset);
+ offset += 2;
+
+ /* PERM is the next 2 bytes of an entry */
+ perm = SVAL(buf, offset);
+ offset += 2;
+
+ /* ID is the last 4 bytes of an entry */
+ id = IVAL(buf, offset);
+ offset += 4;
+
+ switch(tag) {
+ case ACL_USER:
+ smb_ace->a_type = SMB_ACL_USER;
+ break;
+ case ACL_USER_OBJ:
+ smb_ace->a_type = SMB_ACL_USER_OBJ;
+ break;
+ case ACL_GROUP:
+ smb_ace->a_type = SMB_ACL_GROUP;
+ break;
+ case ACL_GROUP_OBJ:
+ smb_ace->a_type = SMB_ACL_GROUP_OBJ;
+ break;
+ case ACL_OTHER:
+ smb_ace->a_type = SMB_ACL_OTHER;
+ break;
+ case ACL_MASK:
+ smb_ace->a_type = SMB_ACL_MASK;
+ break;
+ default:
+ DEBUG(0, ("unknown tag type %d\n", (unsigned int) tag));
+ errno = EINVAL;
+ return NULL;
+ }
+
+
+ switch(smb_ace->a_type) {
+ case SMB_ACL_USER:
+ smb_ace->info.user.uid = id;
+ break;
+ case SMB_ACL_GROUP:
+ smb_ace->info.group.gid = id;
+ break;
+ default:
+ break;
+ }
+
+ smb_ace->a_perm = 0;
+ smb_ace->a_perm |= ((perm & ACL_READ) ? SMB_ACL_READ : 0);
+ smb_ace->a_perm |= ((perm & ACL_WRITE) ? SMB_ACL_WRITE : 0);
+ smb_ace->a_perm |= ((perm & ACL_EXECUTE) ? SMB_ACL_EXECUTE : 0);
+
+ smb_ace++;
+ }
+
+ return result;
+}
+
+
+static int posixacl_xattr_entry_compare(const void *left, const void *right)
+{
+ int ret = 0;
+ uint16_t tag_left, tag_right;
+ uint32_t id_left, id_right;
+
+ /*
+ Sorting precedence:
+ - Smaller TAG values must be earlier.
+ - Within same TAG, smaller identifiers must be earlier, E.g:
+ UID 0 entry must be earlier than UID 200
+ GID 17 entry must be earlier than GID 19
+ */
+
+ /* TAG is the first element in the entry */
+ tag_left = SVAL(left, 0);
+ tag_right = SVAL(right, 0);
+
+ ret = (tag_left - tag_right);
+ if (!ret) {
+ /* ID is the third element in the entry, after two short
+ integers (tag and perm), i.e at offset 4.
+ */
+ id_left = IVAL(left, 4);
+ id_right = IVAL(right, 4);
+ ret = id_left - id_right;
+ }
+
+ return ret;
+}
+
+
+static int smb_acl_to_posixacl_xattr(SMB_ACL_T theacl, char *buf, size_t len)
+{
+ ssize_t size;
+ struct smb_acl_entry *smb_ace;
+ int i;
+ int count;
+ uint16_t tag;
+ uint16_t perm;
+ uint32_t id;
+ int offset;
+
+ count = theacl->count;
+
+ size = ACL_EA_SIZE(count);
+ if (!buf) {
+ return size;
+ }
+ if (len < size) {
+ return -ERANGE;
+ }
+ smb_ace = theacl->acl;
+
+ /* Version is the first 4 bytes of the ACL */
+ SIVAL(buf, 0, ACL_EA_VERSION);
+ offset = ACL_EA_HEADER_SIZE;
+
+ for (i = 0; i < count; i++) {
+ /* Calculate tag */
+ switch(smb_ace->a_type) {
+ case SMB_ACL_USER:
+ tag = ACL_USER;
+ break;
+ case SMB_ACL_USER_OBJ:
+ tag = ACL_USER_OBJ;
+ break;
+ case SMB_ACL_GROUP:
+ tag = ACL_GROUP;
+ break;
+ case SMB_ACL_GROUP_OBJ:
+ tag = ACL_GROUP_OBJ;
+ break;
+ case SMB_ACL_OTHER:
+ tag = ACL_OTHER;
+ break;
+ case SMB_ACL_MASK:
+ tag = ACL_MASK;
+ break;
+ default:
+ DEBUG(0, ("Unknown tag value %d\n",
+ smb_ace->a_type));
+ return -EINVAL;
+ }
+
+
+ /* Calculate id */
+ switch(smb_ace->a_type) {
+ case SMB_ACL_USER:
+ id = smb_ace->info.user.uid;
+ break;
+ case SMB_ACL_GROUP:
+ id = smb_ace->info.group.gid;
+ break;
+ default:
+ id = ACL_UNDEFINED_ID;
+ break;
+ }
+
+ /* Calculate perm */
+ perm = 0;
+ perm |= (smb_ace->a_perm & SMB_ACL_READ) ? ACL_READ : 0;
+ perm |= (smb_ace->a_perm & SMB_ACL_WRITE) ? ACL_WRITE : 0;
+ perm |= (smb_ace->a_perm & SMB_ACL_EXECUTE) ? ACL_EXECUTE : 0;
+
+ /* TAG is the first 2 bytes of an entry */
+ SSVAL(buf, offset, tag);
+ offset += 2;
+
+ /* PERM is the next 2 bytes of an entry */
+ SSVAL(buf, offset, perm);
+ offset += 2;
+
+ /* ID is the last 4 bytes of an entry */
+ SIVAL(buf, offset, id);
+ offset += 4;
+
+ smb_ace++;
+ }
+
+ /* Skip the header, sort @count number of 8-byte entries */
+ qsort(buf+ACL_EA_HEADER_SIZE, count, ACL_EA_ENTRY_SIZE,
+ posixacl_xattr_entry_compare);
+
+ return size;
+}
+
+SMB_ACL_T posixacl_xattr_acl_get_fd(vfs_handle_struct *handle,
+ files_struct *fsp,
+ SMB_ACL_TYPE_T type,
+ TALLOC_CTX *mem_ctx)
+{
+ int ret;
+ int size = ACL_EA_SIZE(20);
+ char *buf = alloca(size);
+ const char *name;
+
+ if (type == SMB_ACL_TYPE_ACCESS) {
+ name = ACL_EA_ACCESS;
+ } else if (type == SMB_ACL_TYPE_DEFAULT) {
+ name = ACL_EA_DEFAULT;
+ } else {
+ errno = EINVAL;
+ return NULL;
+ }
+
+ if (!buf) {
+ return NULL;
+ }
+
+ ret = SMB_VFS_FGETXATTR(fsp, name, buf, size);
+ if (ret < 0 && errno == ERANGE) {
+ size = SMB_VFS_FGETXATTR(fsp, name, NULL, 0);
+ if (size > 0) {
+ buf = alloca(size);
+ if (!buf) {
+ return NULL;
+ }
+ ret = SMB_VFS_FGETXATTR(fsp, name, buf, size);
+ }
+ }
+
+ if (ret > 0) {
+ return posixacl_xattr_to_smb_acl(buf, ret, mem_ctx);
+ }
+ if (ret == 0 || errno == ENOATTR) {
+ SMB_STRUCT_STAT sbuf;
+ ret = SMB_VFS_FSTAT(fsp, &sbuf);
+ if (ret == 0)
+ return mode_to_smb_acl(sbuf.st_ex_mode, mem_ctx);
+ }
+ return NULL;
+}
+
+int posixacl_xattr_acl_set_fd(vfs_handle_struct *handle,
+ files_struct *fsp,
+ SMB_ACL_TYPE_T type,
+ SMB_ACL_T theacl)
+{
+ const char *name = NULL;
+ char *buf;
+ ssize_t size;
+ int ret;
+
+ if (type == SMB_ACL_TYPE_ACCESS) {
+ name = ACL_EA_ACCESS;
+ } else if (type == SMB_ACL_TYPE_DEFAULT) {
+ name = ACL_EA_DEFAULT;
+ } else {
+ errno = EINVAL;
+ return -1;
+ }
+
+ size = smb_acl_to_posixacl_xattr(theacl, NULL, 0);
+ buf = alloca(size);
+ if (!buf) {
+ return -1;
+ }
+
+ ret = smb_acl_to_posixacl_xattr(theacl, buf, size);
+ if (ret < 0) {
+ errno = -ret;
+ return -1;
+ }
+
+ return SMB_VFS_FSETXATTR(fsp, name, buf, size, 0);
+}
+
+int posixacl_xattr_acl_delete_def_fd(vfs_handle_struct *handle,
+ files_struct *fsp)
+{
+ return SMB_VFS_FREMOVEXATTR(fsp, ACL_EA_DEFAULT);
+}
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