cifs: Parse owner/group for stat in smb311 posix extensions

stat was returning default owner and group (unlike readdir)
for SMB3.1.1 POSIX extensions

Signed-off-by: Volker Lendecke <[e-mail]>
Reviewed-by: Paulo Alcantara (SUSE) <[e-mail]>
Signed-off-by: Steve French <[e-mail]>

fs/cifs/inode.c

···
 
 /* Fill a cifs_fattr struct with info from POSIX info struct */
 static void smb311_posix_info_to_fattr(struct cifs_fattr *fattr, struct cifs_open_info_data *data,
+				       struct cifs_sid *owner,
+				       struct cifs_sid *group,
 				       struct super_block *sb, bool adjust_tz, bool symlink)
 {
 	struct smb311_posix_qinfo *info = &data->posix_fi;
···
 	}
 	/* else if reparse point ... TODO: add support for FIFO and blk dev; special file types */
 
-	fattr->cf_uid = cifs_sb->ctx->linux_uid; /* TODO: map uid and gid from SID */
-	fattr->cf_gid = cifs_sb->ctx->linux_gid;
+	sid_to_id(cifs_sb, owner, fattr, SIDOWNER);
+	sid_to_id(cifs_sb, group, fattr, SIDGROUP);
 
 	cifs_dbg(FYI, "POSIX query info: mode 0x%x uniqueid 0x%llx nlink %d\n",
 		fattr->cf_mode, fattr->cf_uniqueid, fattr->cf_nlink);
···
 	struct cifs_fattr fattr = {0};
 	bool symlink = false;
 	struct cifs_open_info_data data = {};
+	struct cifs_sid owner, group;
 	int rc = 0;
 	int tmprc = 0;
 
···
 		goto out;
 	}
 
-	rc = smb311_posix_query_path_info(xid, tcon, cifs_sb, full_path, &data, &adjust_tz,
+	rc = smb311_posix_query_path_info(xid, tcon, cifs_sb, full_path, &data,
+					  &owner, &group, &adjust_tz,
 					  &symlink);
 
 	/*
···
 
 	switch (rc) {
 	case 0:
-		smb311_posix_info_to_fattr(&fattr, &data, sb, adjust_tz, symlink);
+		smb311_posix_info_to_fattr(&fattr, &data, &owner, &group,
+					   sb, adjust_tz, symlink);
 		break;
 	case -EREMOTE:
 		/* DFS link, no metadata available on this server */

fs/cifs/smb2inode.c

···
 				&rsp_iov[1], sizeof(idata->posix_fi) /* add SIDs */,
 				(char *)&idata->posix_fi);
 		}
+		if (rc == 0) {
+			unsigned int length = le32_to_cpu(qi_rsp->OutputBufferLength);
+
+			if (length > sizeof(idata->posix_fi)) {
+				char *base = (char *)rsp_iov[1].iov_base +
+					le16_to_cpu(qi_rsp->OutputBufferOffset) +
+					sizeof(idata->posix_fi);
+				*extbuflen = length - sizeof(idata->posix_fi);
+				*extbuf = kmemdup(base, *extbuflen, GFP_KERNEL);
+				if (!*extbuf)
+					rc = -ENOMEM;
+			} else {
+				rc = -EINVAL;
+			}
+		}
 		if (rqst[1].rq_iov)
 			SMB2_query_info_free(&rqst[1]);
 		if (rqst[2].rq_iov)
···
 
 int smb311_posix_query_path_info(const unsigned int xid, struct cifs_tcon *tcon,
 				 struct cifs_sb_info *cifs_sb, const char *full_path,
-				 struct cifs_open_info_data *data, bool *adjust_tz, bool *reparse)
+				 struct cifs_open_info_data *data,
+				 struct cifs_sid *owner,
+				 struct cifs_sid *group,
+				 bool *adjust_tz, bool *reparse)
 {
 	int rc;
 	__u32 create_options = 0;
 	struct cifsFileInfo *cfile;
 	struct kvec err_iov[3] = {};
 	int err_buftype[3] = {};
+	__u8 *sidsbuf = NULL;
+	__u8 *sidsbuf_end = NULL;
+	size_t sidsbuflen = 0;
+	size_t owner_len, group_len;
 
 	*adjust_tz = false;
 	*reparse = false;
···
 	cifs_get_readable_path(tcon, full_path, &cfile);
 	rc = smb2_compound_op(xid, tcon, cifs_sb, full_path, FILE_READ_ATTRIBUTES, FILE_OPEN,
 			      create_options, ACL_NO_MODE, data, SMB2_OP_POSIX_QUERY_INFO, cfile,
-			      NULL, NULL, err_iov, err_buftype);
+			      &sidsbuf, &sidsbuflen, err_iov, err_buftype);
 	if (rc == -EOPNOTSUPP) {
 		/* BB TODO: When support for special files added to Samba re-verify this path */
 		if (err_iov[0].iov_base && err_buftype[0] != CIFS_NO_BUFFER &&
···
 		cifs_get_readable_path(tcon, full_path, &cfile);
 		rc = smb2_compound_op(xid, tcon, cifs_sb, full_path, FILE_READ_ATTRIBUTES,
 				      FILE_OPEN, create_options, ACL_NO_MODE, data,
-				      SMB2_OP_POSIX_QUERY_INFO, cfile, NULL, NULL, NULL, NULL);
+				      SMB2_OP_POSIX_QUERY_INFO, cfile,
+				      &sidsbuf, &sidsbuflen, NULL, NULL);
+	}
+
+	if (rc == 0) {
+		sidsbuf_end = sidsbuf + sidsbuflen;
+
+		owner_len = posix_info_sid_size(sidsbuf, sidsbuf_end);
+		if (owner_len == -1) {
+			rc = -EINVAL;
+			goto out;
+		}
+		memcpy(owner, sidsbuf, owner_len);
+
+		group_len = posix_info_sid_size(
+			sidsbuf + owner_len, sidsbuf_end);
+		if (group_len == -1) {
+			rc = -EINVAL;
+			goto out;
+		}
+		memcpy(group, sidsbuf + owner_len, group_len);
 	}
 
 out:
+	kfree(sidsbuf);
 	free_rsp_buf(err_buftype[0], err_iov[0].iov_base);
 	free_rsp_buf(err_buftype[1], err_iov[1].iov_base);
 	free_rsp_buf(err_buftype[2], err_iov[2].iov_base);

fs/cifs/smb2proto.h

···
 /* query path info from the server using SMB311 POSIX extensions*/
 int smb311_posix_query_path_info(const unsigned int xid, struct cifs_tcon *tcon,
 				 struct cifs_sb_info *cifs_sb, const char *full_path,
-				 struct cifs_open_info_data *data, bool *adjust_tz, bool *reparse);
+				 struct cifs_open_info_data *data,
+				 struct cifs_sid *owner,
+				 struct cifs_sid *group,
+				 bool *adjust_tz, bool *reparse);
 int posix_info_parse(const void *beg, const void *end,
 		     struct smb2_posix_info_parsed *out);
 int posix_info_sid_size(const void *beg, const void *end);