/*
* iscsi_iser_recv() - Process a successful recv completion
* @conn: iscsi connection
* @hdr: iscsi header
* @rx_data: buffer containing receive data payload
* @rx_data_len: length of rx_data
*
* Notes: In case of data length errors or iscsi PDU completion failures
* this routine will signal iscsi layer of connection failure.
*/
void
iscsi_iser_recv(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
char *rx_data, int rx_data_len)
{
int rc = 0;
int datalen;
/* verify PDU length */
datalen = ntoh24(hdr->dlength);
if (datalen > rx_data_len || (datalen + 4) < rx_data_len) {
iser_err("wrong datalen %d (hdr), %d (IB)\n",
datalen, rx_data_len);
rc = ISCSI_ERR_DATALEN;
goto error;
}
if (datalen != rx_data_len)
iser_dbg("aligned datalen (%d) hdr, %d (IB)\n",
datalen, rx_data_len);
rc = iscsi_complete_pdu(conn, hdr, rx_data, rx_data_len);
if (rc && rc != ISCSI_ERR_NO_SCSI_CMD)
goto error;
return;
error:
iscsi_conn_failure(conn, rc);
}
void
iscsi_iser_recv(struct iscsi_conn *conn,
struct iscsi_hdr *hdr, char *rx_data, int rx_data_len)
{
int rc = 0;
int datalen;
int ahslen;
/* verify PDU length */
datalen = ntoh24(hdr->dlength);
if (datalen != rx_data_len) {
printk(KERN_ERR "iscsi_iser: datalen %d (hdr) != %d (IB) \n",
datalen, rx_data_len);
rc = ISCSI_ERR_DATALEN;
goto error;
}
/* read AHS */
ahslen = hdr->hlength * 4;
rc = iscsi_complete_pdu(conn, hdr, rx_data, rx_data_len);
if (rc && rc != ISCSI_ERR_NO_SCSI_CMD)
goto error;
return;
error:
iscsi_conn_failure(conn, rc);
}
/*
* Handle incoming reply to any other type of command
*/
static int
iscsi_tcp_data_recv_done(struct iscsi_tcp_conn *tcp_conn,
struct iscsi_segment *segment)
{
struct iscsi_conn *conn = tcp_conn->iscsi_conn;
int rc = 0;
if (!iscsi_tcp_dgst_verify(tcp_conn, segment))
return ISCSI_ERR_DATA_DGST;
rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr,
conn->data, tcp_conn->in.datalen);
if (rc)
return rc;
iscsi_tcp_hdr_recv_prep(tcp_conn);
return 0;
}
/*
* Handle incoming reply to DataIn command
*/
static int
iscsi_tcp_process_data_in(struct iscsi_tcp_conn *tcp_conn,
struct iscsi_segment *segment)
{
struct iscsi_conn *conn = tcp_conn->iscsi_conn;
struct iscsi_hdr *hdr = tcp_conn->in.hdr;
int rc;
if (!iscsi_tcp_dgst_verify(tcp_conn, segment))
return ISCSI_ERR_DATA_DGST;
/* check for non-exceptional status */
if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, NULL, 0);
if (rc)
return rc;
}
iscsi_tcp_hdr_recv_prep(tcp_conn);
return 0;
}
/**
* iscsi_tcp_hdr_dissect - process PDU header
* @conn: iSCSI connection
* @hdr: PDU header
*
* This function analyzes the header of the PDU received,
* and performs several sanity checks. If the PDU is accompanied
* by data, the receive buffer is set up to copy the incoming data
* to the correct location.
*/
static int
iscsi_tcp_hdr_dissect(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
{
int rc = 0, opcode, ahslen;
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
struct iscsi_task *task;
/* verify PDU length */
tcp_conn->in.datalen = ntoh24(hdr->dlength);
if (tcp_conn->in.datalen > conn->max_recv_dlength) {
iscsi_conn_printk(KERN_ERR, conn,
"iscsi_tcp: datalen %d > %d\n",
tcp_conn->in.datalen, conn->max_recv_dlength);
return ISCSI_ERR_DATALEN;
}
/* Additional header segments. So far, we don't
* process additional headers.
*/
ahslen = hdr->hlength << 2;
opcode = hdr->opcode & ISCSI_OPCODE_MASK;
/* verify itt (itt encoding: age+cid+itt) */
rc = iscsi_verify_itt(conn, hdr->itt);
if (rc)
return rc;
ISCSI_DBG_TCP(conn, "opcode 0x%x ahslen %d datalen %d\n",
opcode, ahslen, tcp_conn->in.datalen);
switch(opcode) {
case ISCSI_OP_SCSI_DATA_IN:
spin_lock(&conn->session->lock);
task = iscsi_itt_to_ctask(conn, hdr->itt);
if (!task)
rc = ISCSI_ERR_BAD_ITT;
else
rc = iscsi_tcp_data_in(conn, task);
if (rc) {
spin_unlock(&conn->session->lock);
break;
}
if (tcp_conn->in.datalen) {
struct iscsi_tcp_task *tcp_task = task->dd_data;
struct hash_desc *rx_hash = NULL;
struct scsi_data_buffer *sdb = scsi_in(task->sc);
/*
* Setup copy of Data-In into the Scsi_Cmnd
* Scatterlist case:
* We set up the iscsi_segment to point to the next
* scatterlist entry to copy to. As we go along,
* we move on to the next scatterlist entry and
* update the digest per-entry.
*/
if (conn->datadgst_en &&
!(conn->session->tt->caps & CAP_DIGEST_OFFLOAD))
rx_hash = tcp_conn->rx_hash;
ISCSI_DBG_TCP(conn, "iscsi_tcp_begin_data_in( "
"offset=%d, datalen=%d)\n",
tcp_task->data_offset,
tcp_conn->in.datalen);
task->last_xfer = jiffies;
rc = iscsi_segment_seek_sg(&tcp_conn->in.segment,
sdb->table.sgl,
sdb->table.nents,
tcp_task->data_offset,
tcp_conn->in.datalen,
iscsi_tcp_process_data_in,
rx_hash);
spin_unlock(&conn->session->lock);
return rc;
}
rc = __iscsi_complete_pdu(conn, hdr, NULL, 0);
spin_unlock(&conn->session->lock);
break;
case ISCSI_OP_SCSI_CMD_RSP:
if (tcp_conn->in.datalen) {
iscsi_tcp_data_recv_prep(tcp_conn);
return 0;
}
rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
break;
case ISCSI_OP_R2T:
spin_lock(&conn->session->lock);
task = iscsi_itt_to_ctask(conn, hdr->itt);
if (!task)
rc = ISCSI_ERR_BAD_ITT;
else if (ahslen)
rc = ISCSI_ERR_AHSLEN;
else if (task->sc->sc_data_direction == DMA_TO_DEVICE) {
task->last_xfer = jiffies;
rc = iscsi_tcp_r2t_rsp(conn, task);
} else
rc = ISCSI_ERR_PROTO;
spin_unlock(&conn->session->lock);
break;
case ISCSI_OP_LOGIN_RSP:
case ISCSI_OP_TEXT_RSP:
case ISCSI_OP_REJECT:
case ISCSI_OP_ASYNC_EVENT:
/*
* It is possible that we could get a PDU with a buffer larger
* than 8K, but there are no targets that currently do this.
* For now we fail until we find a vendor that needs it
*/
if (ISCSI_DEF_MAX_RECV_SEG_LEN < tcp_conn->in.datalen) {
iscsi_conn_printk(KERN_ERR, conn,
"iscsi_tcp: received buffer of "
"len %u but conn buffer is only %u "
"(opcode %0x)\n",
tcp_conn->in.datalen,
ISCSI_DEF_MAX_RECV_SEG_LEN, opcode);
rc = ISCSI_ERR_PROTO;
break;
}
/* If there's data coming in with the response,
* receive it to the connection's buffer.
*/
if (tcp_conn->in.datalen) {
iscsi_tcp_data_recv_prep(tcp_conn);
return 0;
}
/* fall through */
case ISCSI_OP_LOGOUT_RSP:
case ISCSI_OP_NOOP_IN:
case ISCSI_OP_SCSI_TMFUNC_RSP:
rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
break;
default:
rc = ISCSI_ERR_BAD_OPCODE;
break;
}
if (rc == 0) {
/* Anything that comes with data should have
* been handled above. */
if (tcp_conn->in.datalen)
return ISCSI_ERR_PROTO;
iscsi_tcp_hdr_recv_prep(tcp_conn);
}
return rc;
}
