Libiscsi: Adding transport layer into all library utilities

lib/init: initializing connection transport

lib/socket: Adding function to initialize tcp transport.
            future commits will include adding iSER transport layer,
            so each transport option will has it's own template of functions.

all_utils: All utils stay the same, in future iSER commits in case of
	   iSER transport we will override tcp_transport in
	   iscsi_context.

connect: adding transport initialization when creating context

include/iscsi-private: Adding iscsi_transport attribute in iscsi_context

Signed-off-by: Roy Shterman <roysh@mellanox.com>

Make iscsi_init_tcp_transport private

Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>

include/iscsi-private.h

@@ -66,7 +66,21 @@ void iscsi_free_iscsi_inqueue(struct iscsi_context *iscsi, struct iscsi_in_pdu *
 /* max length of chap challange */
 #define MAX_CHAP_C_LENGTH 2048
 
+struct iscsi_transport {
+
+	int temp;
+};
+
+struct tcp_transport {
+
+	struct iscsi_transport t;
+
+};
+
 struct iscsi_context {
+
+	struct iscsi_transport *t;
+	enum iscsi_transport_type transport;
 	char initiator_name[MAX_STRING_SIZE+1];
 	char target_name[MAX_STRING_SIZE+1];
 	char target_address[MAX_STRING_SIZE+1];  /* If a redirect */
@@ -372,6 +386,8 @@ void iscsi_timeout_scan(struct iscsi_context *iscsi);
 void iscsi_reconnect_cb(struct iscsi_context *iscsi _U_, int status,
                         void *command_data, void *private_data);
 
+void iscsi_init_tcp_transport(struct iscsi_context *iscsi);
+
 #ifdef __cplusplus
 }
 #endif

include/iscsi.h

@@ -50,6 +50,9 @@ struct sockaddr;
 #define ISCSI_PORTAL_URL_SYNTAX "\"iscsi://[<username>[%<password>]@]" \
   "<host>[:<port>]\""
 
+enum iscsi_transport_type {
+	TCP_TRANSPORT = 0
+};
 
 EXTERN void iscsi_set_cache_allocations(struct iscsi_context *iscsi, int ca);
 
@@ -244,6 +247,18 @@ EXTERN struct iscsi_context *iscsi_create_context(const char *initiator_name);
  */
 EXTERN int iscsi_destroy_context(struct iscsi_context *iscsi);
 
+/*
+ * Sets and initializes the transport type for a context.
+ * TCP_TRANSPORT is the default and is available on all platforms.
+ * ISER_TRANSPORT is conditionally supported on Linux where available.
+ *
+ * Returns:
+ *  0: success
+ * <0: error
+ */
+EXTERN int iscsi_init_transport(struct iscsi_context *iscsi,
+                                enum iscsi_transport_type transport);
+
 /*
  * Set an optional alias name to identify with when connecting to the target
  *

lib/init.c

@@ -34,6 +34,39 @@
 #include "iscsi-private.h"
 #include "slist.h"
 
+
+/**
+ * Initialize transport type of session
+ */
+
+int iscsi_init_transport(struct iscsi_context *iscsi,
+			 enum iscsi_transport_type transport) {
+	struct tcp_transport *tcp_transport;
+
+	if (iscsi->t) {
+		iscsi_free(iscsi, iscsi->t);
+		iscsi->t = NULL;
+	}
+	iscsi->transport = transport;
+
+	switch (iscsi->transport) {
+	case TCP_TRANSPORT:
+		tcp_transport = iscsi_malloc(iscsi, sizeof(struct tcp_transport));
+		if (tcp_transport == NULL) {
+			iscsi_set_error(iscsi, "Couldn't allocate memory for transport\n");
+			return -1;
+		}
+		iscsi->t = &tcp_transport->t;
+		iscsi_init_tcp_transport(iscsi);
+		break;
+	default:
+		iscsi_set_error(iscsi, "Unfamiliar transport type");
+		return -1;
+	}
+
+	return 0;
+}
+
 /**
  * Whether or not the internal memory allocator caches allocations. Disable
  * memory allocation caching to improve the accuracy of Valgrind reports.
@@ -122,13 +155,19 @@ iscsi_create_context(const char *initiator_name)
 	if (iscsi == NULL) {
 		return NULL;
 	}
-	
+
 	memset(iscsi, 0, sizeof(struct iscsi_context));
 
+	/* initalize transport of context */
+	if (iscsi_init_transport(iscsi, TCP_TRANSPORT)) {
+		iscsi_set_error(iscsi, "Failed allocating transport");
+		return NULL;
+	}
+
 	strncpy(iscsi->initiator_name,initiator_name,MAX_STRING_SIZE);
 
 	iscsi->fd = -1;
-	
+
 	srand(time(NULL) ^ getpid() ^ (uint32_t) ((uintptr_t) iscsi));
 
 	/* initialize to a "random" isid */

lib/libiscsi.def

@@ -16,6 +16,7 @@ iscsi_get_lba_status_sync
 iscsi_get_lba_status_task
 iscsi_get_target_address
 iscsi_get_nops_in_flight
+iscsi_init_transport
 iscsi_inquiry_sync
 iscsi_inquiry_task
 iscsi_is_logged_in

lib/libiscsi.syms

@@ -14,6 +14,7 @@ iscsi_get_lba_status_sync
 iscsi_get_lba_status_task
 iscsi_get_target_address
 iscsi_get_nops_in_flight
+iscsi_init_transport
 iscsi_inquiry_sync
 iscsi_inquiry_task
 iscsi_is_logged_in

lib/socket.c

@@ -72,6 +72,14 @@
 #include "slist.h"
 
 static uint32_t iface_rr = 0;
+struct iscsi_transport;
+
+void iscsi_init_tcp_transport(struct iscsi_context *iscsi)
+{
+	iscsi->t = NULL;
+
+	return;
+}
 
 void
 iscsi_add_to_outqueue(struct iscsi_context *iscsi, struct iscsi_pdu *pdu)