diff --git a/block/iscsi/pdu.c b/block/iscsi/pdu.c
new file mode 100644
index 0000000..ff3aecf
--- /dev/null
+++ b/block/iscsi/pdu.c
@@ -0,0 +1,339 @@
+/*
+   Copyright (C) 2010 by Ronnie Sahlberg <ronniesahlberg@gmail.com>
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <strings.h>
+#include <string.h>
+#include <arpa/inet.h>
+#include "iscsi.h"
+#include "iscsi-private.h"
+#include "scsi-lowlevel.h"
+#include "slist.h"
+
+struct iscsi_pdu *
+iscsi_allocate_pdu(struct iscsi_context *iscsi, enum iscsi_opcode opcode,
+		   enum iscsi_opcode response_opcode)
+{
+	struct iscsi_pdu *pdu;
+
+	pdu = malloc(sizeof(struct iscsi_pdu));
+	if (pdu == NULL) {
+		iscsi_set_error(iscsi, "failed to allocate pdu\n");
+		return NULL;
+	}
+	bzero(pdu, sizeof(struct iscsi_pdu));
+
+	pdu->outdata.size = ISCSI_HEADER_SIZE;
+	pdu->outdata.data = malloc(pdu->outdata.size);
+
+	if (pdu->outdata.data == NULL) {
+		iscsi_set_error(iscsi, "failed to allocate pdu header\n");
+		free(pdu);
+		pdu = NULL;
+		return NULL;
+	}
+	bzero(pdu->outdata.data, pdu->outdata.size);
+
+	/* opcode */
+	pdu->outdata.data[0] = opcode;
+	pdu->response_opcode = response_opcode;
+
+	/* isid */
+	if (opcode == ISCSI_PDU_LOGIN_REQUEST) {
+		memcpy(&pdu->outdata.data[8], &iscsi->isid[0], 6);
+	}
+
+	/* itt */
+	*(uint32_t *)&pdu->outdata.data[16] = htonl(iscsi->itt);
+	pdu->itt = iscsi->itt;
+
+	iscsi->itt++;
+
+	return pdu;
+}
+
+void
+iscsi_free_pdu(struct iscsi_context *iscsi, struct iscsi_pdu *pdu)
+{
+	if (pdu == NULL) {
+		iscsi_set_error(iscsi, "trying to free NULL pdu");
+		return;
+	}
+	if (pdu->outdata.data) {
+		free(pdu->outdata.data);
+		pdu->outdata.data = NULL;
+	}
+	if (pdu->indata.data) {
+		free(pdu->indata.data);
+		pdu->indata.data = NULL;
+	}
+	if (pdu->scsi_cbdata) {
+		iscsi_free_scsi_cbdata(pdu->scsi_cbdata);
+		pdu->scsi_cbdata = NULL;
+	}
+
+	free(pdu);
+}
+
+
+int
+iscsi_add_data(struct iscsi_context *iscsi, struct iscsi_data *data,
+	       unsigned char *dptr, int dsize, int pdualignment)
+{
+	int len, aligned;
+	unsigned char *buf;
+
+	if (dsize == 0) {
+		iscsi_set_error(iscsi, "Trying to append zero size data to "
+				"iscsi_data\n");
+		return -1;
+	}
+
+	len = data->size + dsize;
+	aligned = len;
+	if (pdualignment) {
+		aligned = (aligned+3)&0xfffffffc;
+	}
+	buf = malloc(aligned);
+	if (buf == NULL) {
+		iscsi_set_error(iscsi, "failed to allocate buffer for %d "
+				"bytes\n", len);
+		return -2;
+	}
+
+	if (data->size > 0) {
+		memcpy(buf, data->data, data->size);
+	}
+	memcpy(buf + data->size, dptr, dsize);
+	if (len != aligned) {
+		/* zero out any padding at the end */
+	       bzero(buf+len, aligned-len);
+	}
+
+	if (data->data != NULL) {
+		free(data->data);
+	}
+	data->data  = buf;
+	data->size = len;
+
+	return 0;
+}
+
+int
+iscsi_pdu_add_data(struct iscsi_context *iscsi, struct iscsi_pdu *pdu,
+		   unsigned char *dptr, int dsize)
+{
+	if (pdu == NULL) {
+		iscsi_set_error(iscsi, "trying to add data to NULL pdu\n");
+		return -1;
+	}
+	if (dsize == 0) {
+		iscsi_set_error(iscsi, "Trying to append zero size data to "
+				"pdu\n");
+		return -2;
+	}
+
+	if (iscsi_add_data(iscsi, &pdu->outdata, dptr, dsize, 1) != 0) {
+		iscsi_set_error(iscsi, "failed to add data to pdu buffer\n");
+		return -3;
+	}
+
+	/* update data segment length */
+	*(uint32_t *)&pdu->outdata.data[4] = htonl(pdu->outdata.size
+						   - ISCSI_HEADER_SIZE);
+
+	return 0;
+}
+
+int
+iscsi_get_pdu_size(struct iscsi_context *iscsi, const unsigned char *hdr)
+{
+	int size;
+
+	size = (ntohl(*(uint32_t *)&hdr[4])&0x00ffffff) + ISCSI_HEADER_SIZE;
+	size = (size+3)&0xfffffffc;
+
+	return size;
+}
+
+
+int
+iscsi_process_pdu(struct iscsi_context *iscsi, const unsigned char *hdr,
+		  int size)
+{
+	uint32_t itt;
+	enum iscsi_opcode opcode;
+	struct iscsi_pdu *pdu;
+	uint8_t	ahslen;
+
+	opcode = hdr[0] & 0x3f;
+	ahslen = hdr[4];
+	itt = ntohl(*(uint32_t *)&hdr[16]);
+
+	if (ahslen != 0) {
+		iscsi_set_error(iscsi, "cant handle expanded headers yet\n");
+		return -1;
+	}
+
+	for (pdu = iscsi->waitpdu; pdu; pdu = pdu->next) {
+		enum iscsi_opcode expected_response = pdu->response_opcode;
+		int is_finished = 1;
+
+		if (pdu->itt != itt) {
+			continue;
+		}
+
+		/* we have a special case with scsi-command opcodes,
+		 * they are replied to by either a scsi-response
+		 * or a data-in, or a combination of both.
+		 */
+		if (opcode == ISCSI_PDU_DATA_IN
+		    && expected_response == ISCSI_PDU_SCSI_RESPONSE) {
+			expected_response = ISCSI_PDU_DATA_IN;
+		}
+
+		if (opcode != expected_response) {
+			iscsi_set_error(iscsi, "Got wrong opcode back for "
+					"itt:%d  got:%d expected %d\n",
+					itt, opcode, pdu->response_opcode);
+			return -1;
+		}
+		switch (opcode) {
+		case ISCSI_PDU_LOGIN_RESPONSE:
+			if (iscsi_process_login_reply(iscsi, pdu, hdr, size)
+			    != 0) {
+				SLIST_REMOVE(&iscsi->waitpdu, pdu);
+				iscsi_free_pdu(iscsi, pdu);
+				iscsi_set_error(iscsi, "iscsi login reply "
+						"failed\n");
+				return -2;
+			}
+			break;
+		case ISCSI_PDU_TEXT_RESPONSE:
+			if (iscsi_process_text_reply(iscsi, pdu, hdr, size)
+			    != 0) {
+				SLIST_REMOVE(&iscsi->waitpdu, pdu);
+				iscsi_free_pdu(iscsi, pdu);
+				iscsi_set_error(iscsi, "iscsi text reply "
+						"failed\n");
+				return -2;
+			}
+			break;
+		case ISCSI_PDU_LOGOUT_RESPONSE:
+			if (iscsi_process_logout_reply(iscsi, pdu, hdr, size)
+			    != 0) {
+				SLIST_REMOVE(&iscsi->waitpdu, pdu);
+				iscsi_free_pdu(iscsi, pdu);
+				iscsi_set_error(iscsi, "iscsi logout reply "
+						"failed\n");
+				return -3;
+			}
+			break;
+		case ISCSI_PDU_SCSI_RESPONSE:
+			if (iscsi_process_scsi_reply(iscsi, pdu, hdr, size)
+			    != 0) {
+				SLIST_REMOVE(&iscsi->waitpdu, pdu);
+				iscsi_free_pdu(iscsi, pdu);
+				iscsi_set_error(iscsi, "iscsi response reply "
+						"failed\n");
+				return -4;
+			}
+			break;
+		case ISCSI_PDU_DATA_IN:
+			if (iscsi_process_scsi_data_in(iscsi, pdu, hdr, size,
+						       &is_finished) != 0) {
+				SLIST_REMOVE(&iscsi->waitpdu, pdu);
+				iscsi_free_pdu(iscsi, pdu);
+				iscsi_set_error(iscsi, "iscsi data in "
+						"failed\n");
+				return -4;
+			}
+			break;
+		case ISCSI_PDU_NOP_IN:
+			if (iscsi_process_nop_out_reply(iscsi, pdu, hdr, size)
+			    != 0) {
+				SLIST_REMOVE(&iscsi->waitpdu, pdu);
+				iscsi_free_pdu(iscsi, pdu);
+				iscsi_set_error(iscsi, "iscsi nop-in failed\n");
+				return -5;
+			}
+			break;
+		default:
+			iscsi_set_error(iscsi, "Dont know how to handle "
+					"opcode %d\n", opcode);
+			return -2;
+		}
+
+		if (is_finished) {
+			SLIST_REMOVE(&iscsi->waitpdu, pdu);
+			iscsi_free_pdu(iscsi, pdu);
+		}
+		return 0;
+	}
+
+	return 0;
+}
+
+void
+iscsi_pdu_set_pduflags(struct iscsi_pdu *pdu, unsigned char flags)
+{
+	pdu->outdata.data[1] = flags;
+}
+
+void
+iscsi_pdu_set_immediate(struct iscsi_pdu *pdu)
+{
+	pdu->outdata.data[0] |= ISCSI_PDU_IMMEDIATE;
+}
+
+void
+iscsi_pdu_set_ttt(struct iscsi_pdu *pdu, uint32_t ttt)
+{
+	*(uint32_t *)&pdu->outdata.data[20] = htonl(ttt);
+}
+
+void
+iscsi_pdu_set_cmdsn(struct iscsi_pdu *pdu, uint32_t cmdsn)
+{
+	*(uint32_t *)&pdu->outdata.data[24] = htonl(cmdsn);
+}
+
+void
+iscsi_pdu_set_expstatsn(struct iscsi_pdu *pdu, uint32_t expstatsnsn)
+{
+	*(uint32_t *)&pdu->outdata.data[28] = htonl(expstatsnsn);
+}
+
+void
+iscsi_pdu_set_cdb(struct iscsi_pdu *pdu, struct scsi_task *task)
+{
+	bzero(&pdu->outdata.data[32], 16);
+	memcpy(&pdu->outdata.data[32], task->cdb, task->cdb_size);
+}
+
+void
+iscsi_pdu_set_lun(struct iscsi_pdu *pdu, uint32_t lun)
+{
+	pdu->outdata.data[9] = lun;
+}
+
+void
+iscsi_pdu_set_expxferlen(struct iscsi_pdu *pdu, uint32_t expxferlen)
+{
+	*(uint32_t *)&pdu->outdata.data[20] = htonl(expxferlen);
+}
