Adding upstream version 2:4.20.0+dfsg.upstream/2%4.20.0+dfsg

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

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);
+}