1 files changed, 87 insertions, 0 deletions
diff --git a/source3/libsmb/async_smb.c b/source3/libsmb/async_smb.c
index 7474959902..7afba0dae9 100644
--- a/source3/libsmb/async_smb.c
+++ b/source3/libsmb/async_smb.c
@@ -19,6 +19,93 @@
 
 #include "includes.h"
 
+/*
+ * Read an smb packet asynchronously, discard keepalives
+ */
+
+struct read_smb_state {
+	struct tevent_context *ev;
+	int fd;
+	uint8_t *buf;
+};
+
+static ssize_t read_smb_more(uint8_t *buf, size_t buflen, void *private_data);
+static void read_smb_done(struct tevent_req *subreq);
+
+static struct tevent_req *read_smb_send(TALLOC_CTX *mem_ctx,
+					struct tevent_context *ev,
+					int fd)
+{
+	struct tevent_req *result, *subreq;
+	struct read_smb_state *state;
+
+	result = tevent_req_create(mem_ctx, &state, struct read_smb_state);
+	if (result == NULL) {
+		return NULL;
+	}
+	state->ev = ev;
+	state->fd = fd;
+
+	subreq = read_packet_send(state, ev, fd, 4, read_smb_more, NULL);
+	if (subreq == NULL) {
+		goto fail;
+	}
+	tevent_req_set_callback(subreq, read_smb_done, result);
+	return result;
+ fail:
+	TALLOC_FREE(result);
+	return NULL;
+}
+
+static ssize_t read_smb_more(uint8_t *buf, size_t buflen, void *private_data)
+{
+	if (buflen > 4) {
+		return 0;	/* We've been here, we're done */
+	}
+	return smb_len_large(buf);
+}
+
+static void read_smb_done(struct tevent_req *subreq)
+{
+	struct tevent_req *req = tevent_req_callback_data(
+		subreq, struct tevent_req);
+	struct read_smb_state *state = tevent_req_data(
+		req, struct read_smb_state);
+	ssize_t len;
+	int err;
+
+	len = read_packet_recv(subreq, state, &state->buf, &err);
+	TALLOC_FREE(subreq);
+	if (len == -1) {
+		tevent_req_error(req, err);
+		return;
+	}
+
+	if (CVAL(state->buf, 0) == SMBkeepalive) {
+		subreq = read_packet_send(state, state->ev, state->fd, 4,
+					  read_smb_more, NULL);
+		if (tevent_req_nomem(subreq, req)) {
+			return;
+		}
+		tevent_req_set_callback(subreq, read_smb_done, req);
+		return;
+	}
+	tevent_req_done(req);
+}
+
+static ssize_t read_smb_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
+			     uint8_t **pbuf, int *perrno)
+{
+	struct read_smb_state *state = tevent_req_data(
+		req, struct read_smb_state);
+
+	if (tevent_req_is_unix_error(req, perrno)) {
+		return -1;
+	}
+	*pbuf = talloc_move(mem_ctx, &state->buf);
+	return talloc_get_size(*pbuf);
+}
+
 /**
  * Fetch an error out of a NBT packet
  * @param[in] buf	The SMB packet