From 47b6881b97e6619aa3a4f7dfdb3537fcb81c5435 Mon Sep 17 00:00:00 2001
From: Roy Shterman <roysh@mellanox.com>
Date: Fri, 27 May 2016 18:47:23 +0300
Subject: [PATCH] Libiscsi: Adding abstraction to async functions

future iSER implementation will include different implementations
for all socket relative function. in iSER we get event only when
there is new entry in completion queue opposed to TCP that we get event
when we can write to the socket.

1. iscsi_get_fd -
	TCP - returns socket fd.
	ISER - returns completion queue channel fd.
2. iscsi_service -
	TCP -   processing the event type got from the socket
		and handles it.
	ISER -  rearming the event mechanism in the completion queue
		and polling all available completion queue entries for
		process.
3. iscsi_which_events -
	TCP -   returns which type of event the library is waiting for
		(Read, Write or both).
	ISER -  in iSER we are waiting only for POLLIN event, hence this
		function always returns POLLIN.

Signed-off-by: Roy Shterman <roysh@mellanox.com>
---
 include/iscsi-private.h |  3 +++
 lib/socket.c            | 28 +++++++++++++++++++++++++---
 2 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/include/iscsi-private.h b/include/iscsi-private.h
index f24179a..d2d2cf0 100644
--- a/include/iscsi-private.h
+++ b/include/iscsi-private.h
@@ -395,6 +395,9 @@ struct iscsi_transport {
 	struct iscsi_pdu* (*new_pdu)(struct iscsi_context *iscsi, size_t size);
 	int (*disconnect)(struct iscsi_context *iscsi);
 	void (*free_pdu)(struct iscsi_context *iscsi, struct iscsi_pdu *pdu);
+	int (*service)(struct iscsi_context *iscsi, int revents);
+	int (*get_fd)(struct iscsi_context *iscsi);
+	int (*which_events)(struct iscsi_context *iscsi);
 };
 
 struct tcp_transport {
diff --git a/lib/socket.c b/lib/socket.c
index c4ba1ad..d95da9a 100644
--- a/lib/socket.c
+++ b/lib/socket.c
@@ -390,6 +390,7 @@ iscsi_tcp_disconnect(struct iscsi_context *iscsi)
 	return 0;
 }
 
+
 int
 iscsi_disconnect(struct iscsi_context *iscsi)
 {
@@ -397,7 +398,7 @@ iscsi_disconnect(struct iscsi_context *iscsi)
 }
 
 int
-iscsi_get_fd(struct iscsi_context *iscsi)
+iscsi_tcp_get_fd(struct iscsi_context *iscsi)
 {
 	if (iscsi->old_iscsi) {
 		return iscsi->old_iscsi->fd;
@@ -406,7 +407,13 @@ iscsi_get_fd(struct iscsi_context *iscsi)
 }
 
 int
-iscsi_which_events(struct iscsi_context *iscsi)
+iscsi_get_fd(struct iscsi_context *iscsi)
+{
+	return iscsi->t->get_fd(iscsi);
+}
+
+int
+iscsi_tcp_which_events(struct iscsi_context *iscsi)
 {
 	int events = iscsi->is_connected ? POLLIN : POLLOUT;
 
@@ -426,6 +433,12 @@ iscsi_which_events(struct iscsi_context *iscsi)
 	return events;
 }
 
+int
+iscsi_which_events(struct iscsi_context *iscsi)
+{
+	return iscsi->t->which_events(iscsi);
+}
+
 int
 iscsi_queue_length(struct iscsi_context *iscsi)
 {
@@ -823,7 +836,7 @@ iscsi_service_reconnect_if_loggedin(struct iscsi_context *iscsi)
 }
 
 int
-iscsi_service(struct iscsi_context *iscsi, int revents)
+iscsi_tcp_service(struct iscsi_context *iscsi, int revents)
 {
 	if (iscsi->fd < 0) {
 		return 0;
@@ -925,6 +938,12 @@ iscsi_service(struct iscsi_context *iscsi, int revents)
 	return 0;
 }
 
+int
+iscsi_service(struct iscsi_context *iscsi, int revents)
+{
+	return iscsi->t->service(iscsi, revents);
+}
+
 static int iscsi_tcp_queue_pdu(struct iscsi_context *iscsi,
                                struct iscsi_pdu *pdu)
 {
@@ -1066,6 +1085,9 @@ void iscsi_init_tcp_transport(struct iscsi_context *iscsi)
 	iscsi->t->new_pdu = iscsi_tcp_new_pdu;
 	iscsi->t->disconnect = iscsi_tcp_disconnect;
 	iscsi->t->free_pdu = iscsi_tcp_free_pdu;
+	iscsi->t->service = iscsi_tcp_service;
+	iscsi->t->get_fd = iscsi_tcp_get_fd;
+	iscsi->t->which_events = iscsi_tcp_which_events;
 
 	return;
 }