s3-vfs: add copy_chunk vfs hooks

copy_chunk copies n bytes from a source file at a specific offset to a
destination file at a given offset. This interface will be used in
handling smb2 FSCTL_SRV_COPYCHUNK ioctl requests.

Use a pread/pwrite loop in vfs_default, so that requests referring to
the same src and dest file are possible.

Provide send and receive hooks for copy chunk VFS interface, allowing
asynchronous behaviour.

Check whether the request source offset + length exceeds the current
size. Return STATUS_INVALID_VIEW_SIZE under such a condition, matching
Windows server behaviour.

Reviewed by: Jeremy Allison <jra@samba.org>

1 files changed, 85 insertions, 0 deletions

diff --git a/source3/modules/vfs_time_audit.c b/source3/modules/vfs_time_audit.c
index 95b4148232..1b14d650af 100644
--- a/source3/modules/vfs_time_audit.c
+++ b/source3/modules/vfs_time_audit.c
@@ -29,6 +29,7 @@
 #include "smbd/smbd.h"
 #include "ntioctl.h"
 #include "lib/util/tevent_unix.h"
+#include "lib/util/tevent_ntstatus.h"
 
 #undef DBGC_CLASS
 #define DBGC_CLASS DBGC_VFS
@@ -1668,6 +1669,88 @@ static NTSTATUS smb_time_audit_translate_name(struct vfs_handle_struct *handle,
 	return result;
 }
 
+struct time_audit_cc_state {
+	struct timespec ts_send;
+	struct vfs_handle_struct *handle;
+	off_t copied;
+};
+static void smb_time_audit_copy_chunk_done(struct tevent_req *subreq);
+
+static struct tevent_req *smb_time_audit_copy_chunk_send(struct vfs_handle_struct *handle,
+							 TALLOC_CTX *mem_ctx,
+							 struct tevent_context *ev,
+							 struct files_struct *src_fsp,
+							 off_t src_off,
+							 struct files_struct *dest_fsp,
+							 off_t dest_off,
+							 off_t num)
+{
+	struct tevent_req *req;
+	struct tevent_req *subreq;
+	struct time_audit_cc_state *cc_state;
+
+	req = tevent_req_create(mem_ctx, &cc_state, struct time_audit_cc_state);
+	if (req == NULL) {
+		return NULL;
+	}
+
+	cc_state->handle = handle;
+	clock_gettime_mono(&cc_state->ts_send);
+	subreq = SMB_VFS_NEXT_COPY_CHUNK_SEND(handle, cc_state, ev,
+					      src_fsp, src_off,
+					      dest_fsp, dest_off, num);
+	if (tevent_req_nomem(subreq, req)) {
+		return tevent_req_post(req, ev);
+	}
+
+	tevent_req_set_callback(subreq, smb_time_audit_copy_chunk_done, req);
+	return req;
+}
+
+static void smb_time_audit_copy_chunk_done(struct tevent_req *subreq)
+{
+	struct tevent_req *req = tevent_req_callback_data(
+		subreq, struct tevent_req);
+	struct time_audit_cc_state *cc_state
+			= tevent_req_data(req, struct time_audit_cc_state);
+	NTSTATUS status;
+
+	status = SMB_VFS_NEXT_COPY_CHUNK_RECV(cc_state->handle,
+					      subreq,
+					      &cc_state->copied);
+	TALLOC_FREE(subreq);
+	if (tevent_req_nterror(req, status)) {
+		return;
+	}
+	tevent_req_done(req);
+}
+
+static NTSTATUS smb_time_audit_copy_chunk_recv(struct vfs_handle_struct *handle,
+					       struct tevent_req *req,
+					       off_t *copied)
+{
+	struct time_audit_cc_state *cc_state
+			= tevent_req_data(req, struct time_audit_cc_state);
+	struct timespec ts_recv;
+	double timediff;
+	NTSTATUS status;
+
+	clock_gettime_mono(&ts_recv);
+	timediff = nsec_time_diff(&ts_recv, &cc_state->ts_send)*1.0e-9;
+	if (timediff > audit_timeout) {
+		smb_time_audit_log("copy_chunk", timediff);
+	}
+
+	*copied = cc_state->copied;
+	if (tevent_req_is_nterror(req, &status)) {
+		tevent_req_received(req);
+		return status;
+	}
+
+	tevent_req_received(req);
+	return NT_STATUS_OK;
+}
+
 static NTSTATUS smb_time_audit_fget_nt_acl(vfs_handle_struct *handle,
 					   files_struct *fsp,
 					   uint32 security_info,
@@ -2179,6 +2262,8 @@ static struct vfs_fn_pointers vfs_time_audit_fns = {
 	.strict_lock_fn = smb_time_audit_strict_lock,
 	.strict_unlock_fn = smb_time_audit_strict_unlock,
 	.translate_name_fn = smb_time_audit_translate_name,
+	.copy_chunk_send_fn = smb_time_audit_copy_chunk_send,
+	.copy_chunk_recv_fn = smb_time_audit_copy_chunk_recv,
 	.fget_nt_acl_fn = smb_time_audit_fget_nt_acl,
 	.get_nt_acl_fn = smb_time_audit_get_nt_acl,
 	.fset_nt_acl_fn = smb_time_audit_fset_nt_acl,