tsocket: add tstream_readv_pdu_send/recv()

metze

2 files changed, 178 insertions, 1 deletions

diff --git a/lib/tsocket/tsocket.h b/lib/tsocket/tsocket.h
index 6583a5e786..aef73ae8c5 100644
--- a/lib/tsocket/tsocket.h
+++ b/lib/tsocket/tsocket.h
@@ -190,7 +190,7 @@ int _tstream_bsd_existing_socket(TALLOC_CTX *mem_ctx,
 				     __location__)
 
 /*
- * Queue helpers
+ * Queue and PDU helpers
  */
 
 struct tevent_req *tdgram_sendto_queue_send(TALLOC_CTX *mem_ctx,
@@ -202,5 +202,17 @@ struct tevent_req *tdgram_sendto_queue_send(TALLOC_CTX *mem_ctx,
 					    struct tsocket_address *dst);
 ssize_t tdgram_sendto_queue_recv(struct tevent_req *req, int *perrno);
 
+typedef int (*tstream_readv_pdu_next_vector_t)(struct tstream_context *stream,
+					       void *private_data,
+					       TALLOC_CTX *mem_ctx,
+					       struct iovec **vector,
+					       size_t *count);
+struct tevent_req *tstream_readv_pdu_send(TALLOC_CTX *mem_ctx,
+				struct tevent_context *ev,
+				struct tstream_context *stream,
+				tstream_readv_pdu_next_vector_t next_vector_fn,
+				void *next_vector_private);
+int tstream_readv_pdu_recv(struct tevent_req *req, int *perrno);
+
 #endif /* _TSOCKET_H */
 
diff --git a/lib/tsocket/tsocket_helpers.c b/lib/tsocket/tsocket_helpers.c
index 1876dc3882..1b9a9bf670 100644
--- a/lib/tsocket/tsocket_helpers.c
+++ b/lib/tsocket/tsocket_helpers.c
@@ -22,6 +22,7 @@
 */
 
 #include "replace.h"
+#include "system/filesys.h"
 #include "tsocket.h"
 #include "tsocket_internal.h"
 
@@ -155,3 +156,167 @@ ssize_t tdgram_sendto_queue_recv(struct tevent_req *req, int *perrno)
 	return ret;
 }
 
+struct tstream_readv_pdu_state {
+	/* this structs are owned by the caller */
+	struct {
+		struct tevent_context *ev;
+		struct tstream_context *stream;
+		tstream_readv_pdu_next_vector_t next_vector_fn;
+		void *next_vector_private;
+	} caller;
+
+	/*
+	 * Each call to the callback resets iov and count
+	 * the callback allocated the iov as child of our state,
+	 * that means we are allowed to modify and free it.
+	 *
+	 * we should call the callback every time we filled the given
+	 * vector and ask for a new vector. We return if the callback
+	 * ask for 0 bytes.
+	 */
+	struct iovec *vector;
+	size_t count;
+
+	/*
+	 * the total number of bytes we read,
+	 * the return value of the _recv function
+	 */
+	int total_read;
+};
+
+static void tstream_readv_pdu_ask_for_next_vector(struct tevent_req *req);
+static void tstream_readv_pdu_readv_done(struct tevent_req *subreq);
+
+struct tevent_req *tstream_readv_pdu_send(TALLOC_CTX *mem_ctx,
+				struct tevent_context *ev,
+				struct tstream_context *stream,
+				tstream_readv_pdu_next_vector_t next_vector_fn,
+				void *next_vector_private)
+{
+	struct tevent_req *req;
+	struct tstream_readv_pdu_state *state;
+
+	req = tevent_req_create(mem_ctx, &state,
+				struct tstream_readv_pdu_state);
+	if (!req) {
+		return NULL;
+	}
+
+	state->caller.ev			= ev;
+	state->caller.stream			= stream;
+	state->caller.next_vector_fn		= next_vector_fn;
+	state->caller.next_vector_private	= next_vector_private;
+
+	state->vector		= NULL;
+	state->count		= 0;
+	state->total_read	= 0;
+
+	tstream_readv_pdu_ask_for_next_vector(req);
+	if (!tevent_req_is_in_progress(req)) {
+		goto post;
+	}
+
+	return req;
+
+ post:
+	return tevent_req_post(req, ev);
+}
+
+static void tstream_readv_pdu_ask_for_next_vector(struct tevent_req *req)
+{
+	struct tstream_readv_pdu_state *state = tevent_req_data(req,
+					    struct tstream_readv_pdu_state);
+	int ret;
+	size_t to_read = 0;
+	size_t i;
+	struct tevent_req *subreq;
+
+	TALLOC_FREE(state->vector);
+	state->count = 0;
+
+	ret = state->caller.next_vector_fn(state->caller.stream,
+					   state->caller.next_vector_private,
+					   state, &state->vector, &state->count);
+	if (ret == -1) {
+		tevent_req_error(req, errno);
+		return;
+	}
+
+	if (state->count == 0) {
+		tevent_req_done(req);
+		return;
+	}
+
+	for (i=0; i < state->count; i++) {
+		size_t tmp = to_read;
+		tmp += state->vector[i].iov_len;
+
+		if (tmp < to_read) {
+			tevent_req_error(req, EMSGSIZE);
+			return;
+		}
+
+		to_read = tmp;
+	}
+
+	/*
+	 * this is invalid the next vector function should have
+	 * reported count == 0.
+	 */
+	if (to_read == 0) {
+		tevent_req_error(req, EINVAL);
+		return;
+	}
+
+	if (state->total_read + to_read < state->total_read) {
+		tevent_req_error(req, EMSGSIZE);
+		return;
+	}
+
+	subreq = tstream_readv_send(state,
+				    state->caller.ev,
+				    state->caller.stream,
+				    state->vector,
+				    state->count);
+	if (tevent_req_nomem(subreq, req)) {
+		return;
+	}
+	tevent_req_set_callback(subreq, tstream_readv_pdu_readv_done, req);
+}
+
+static void tstream_readv_pdu_readv_done(struct tevent_req *subreq)
+{
+	struct tevent_req *req = tevent_req_callback_data(subreq,
+				 struct tevent_req);
+	struct tstream_readv_pdu_state *state = tevent_req_data(req,
+					    struct tstream_readv_pdu_state);
+	int ret;
+	int sys_errno;
+
+	ret = tstream_readv_recv(subreq, &sys_errno);
+	if (ret == -1) {
+		tevent_req_error(req, sys_errno);
+		return;
+	}
+
+	state->total_read += ret;
+
+	/* ask the callback for a new vector we should fill */
+	tstream_readv_pdu_ask_for_next_vector(req);
+}
+
+int tstream_readv_pdu_recv(struct tevent_req *req, int *perrno)
+{
+	struct tstream_readv_pdu_state *state = tevent_req_data(req,
+					    struct tstream_readv_pdu_state);
+	int ret;
+
+	ret = tsocket_simple_int_recv(req, perrno);
+	if (ret == 0) {
+		ret = state->total_read;
+	}
+
+	tevent_req_received(req);
+	return ret;
+}
+