From: Anoop C S <anoopcs@samba.org>
Date: Tue, 24 Sep 2024 05:36:58 +0000 (+0530)
Subject: s3/smbd: Add a helper to fetch fs capabilities
X-Git-Tag: samba-4.21.5~15
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8c7d9f39d9fca3d846cc3a8f348af3788c25fd0d;p=thirdparty%2Fsamba.git

s3/smbd: Add a helper to fetch fs capabilities

We create a new helper function to retrieve the fs capabilties via
STATVFS call. Additionally set other capabilities based on specific
parametric options. This is 99.9% taken from SMB_VFS_FS_CAPABILITIES
implementation of vfs_default in preparation to be called from any
required vfs module.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15822

Signed-off-by: Anoop C S <anoopcs@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>
(cherry picked from commit b1fbaefc665a7fb0413a26bd0304f97356fda414)
---

diff --git a/source3/smbd/proto.h b/source3/smbd/proto.h
index 90387aeb6c3..093c60adcfa 100644
--- a/source3/smbd/proto.h
+++ b/source3/smbd/proto.h
@@ -1176,6 +1176,8 @@ NTSTATUS vfs_fstreaminfo(struct files_struct *fsp,
 void init_smb_file_time(struct smb_file_time *ft);
 int vfs_fake_fd(void);
 int vfs_fake_fd_close(int fd);
+uint32_t vfs_get_fs_capabilities(struct connection_struct *conn,
+				 enum timestamp_set_resolution *ts_res);
 
 /* The following definitions come from smbd/avahi_register.c */
 
diff --git a/source3/smbd/vfs.c b/source3/smbd/vfs.c
index 13b3ba61cea..388a5a90fc6 100644
--- a/source3/smbd/vfs.c
+++ b/source3/smbd/vfs.c
@@ -1300,6 +1300,78 @@ NTSTATUS vfs_at_fspcwd(TALLOC_CTX *mem_ctx,
 	return NT_STATUS_OK;
 }
 
+uint32_t vfs_get_fs_capabilities(struct connection_struct *conn,
+				 enum timestamp_set_resolution *ts_res)
+{
+	const struct loadparm_substitution *lp_sub =
+		loadparm_s3_global_substitution();
+	uint32_t caps = FILE_CASE_SENSITIVE_SEARCH | FILE_CASE_PRESERVED_NAMES;
+	struct smb_filename *smb_fname_cpath = NULL;
+	struct vfs_statvfs_struct statbuf;
+	int ret;
+
+	smb_fname_cpath = synthetic_smb_fname(talloc_tos(),
+					      conn->connectpath,
+					      NULL,
+					      NULL,
+					      0,
+					      0);
+	if (smb_fname_cpath == NULL) {
+		return caps;
+	}
+
+	ZERO_STRUCT(statbuf);
+	ret = SMB_VFS_STATVFS(conn, smb_fname_cpath, &statbuf);
+	if (ret == 0) {
+		caps = statbuf.FsCapabilities;
+	}
+
+	if (lp_nt_acl_support(SNUM(conn))) {
+		caps |= FILE_PERSISTENT_ACLS;
+	}
+
+	caps |= lp_parm_int(SNUM(conn), "share", "fake_fscaps", 0);
+
+	*ts_res = TIMESTAMP_SET_SECONDS;
+
+	/* Work out what timestamp resolution we can
+	 * use when setting a timestamp. */
+
+	ret = SMB_VFS_STAT(conn, smb_fname_cpath);
+	if (ret == -1) {
+		TALLOC_FREE(smb_fname_cpath);
+		return caps;
+	}
+
+	if (smb_fname_cpath->st.st_ex_mtime.tv_nsec ||
+			smb_fname_cpath->st.st_ex_atime.tv_nsec ||
+			smb_fname_cpath->st.st_ex_ctime.tv_nsec) {
+		/* If any of the normal UNIX directory timestamps
+		 * have a non-zero tv_nsec component assume
+		 * we might be able to set sub-second timestamps.
+		 * See what filetime set primitives we have.
+		 */
+#if defined(HAVE_UTIMENSAT)
+		*ts_res = TIMESTAMP_SET_NT_OR_BETTER;
+#elif defined(HAVE_UTIMES)
+		/* utimes allows msec timestamps to be set. */
+		*ts_res = TIMESTAMP_SET_MSEC;
+#elif defined(HAVE_UTIME)
+		/* utime only allows sec timestamps to be set. */
+		*ts_res = TIMESTAMP_SET_SECONDS;
+#endif
+
+		DBG_DEBUG("vfs_get_fs_capabilities: timestamp "
+			  "resolution of %s "
+			  "available on share %s, directory %s\n",
+			  *ts_res == TIMESTAMP_SET_MSEC ? "msec" : "sec",
+			  lp_servicename(talloc_tos(), lp_sub, conn->params->service),
+			  conn->connectpath );
+	}
+	TALLOC_FREE(smb_fname_cpath);
+	return caps;
+}
+
 static struct smb_vfs_deny_state *smb_vfs_deny_global;
 
 void smb_vfs_assert_allowed(void)