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-rw-r--r--src/include/gpxe/iscsi.h138
-rw-r--r--src/include/gpxe/scsi.h10
-rw-r--r--src/net/tcp/iscsi.c210
3 files changed, 304 insertions, 54 deletions
diff --git a/src/include/gpxe/iscsi.h b/src/include/gpxe/iscsi.h
index 0419f0681..c1161de95 100644
--- a/src/include/gpxe/iscsi.h
+++ b/src/include/gpxe/iscsi.h
@@ -85,33 +85,6 @@ struct iscsi_bhs_common {
* iSCSI basic header segment common request fields
*
*/
-struct iscsi_bhs_common_request {
- /** Opcode */
- uint8_t opcode;
- /** Flags */
- uint8_t flags;
- /** Fields specific to the PDU type */
- uint8_t other_a[2];
- /** Segment lengths */
- union iscsi_segment_lengths lengths;
- /** Fields specific to the PDU type */
- uint8_t other_b[8];
- /** Initiator Task Tag */
- uint32_t itt;
- /** Fields specific to the PDU type */
- uint8_t other_c[4];
- /** Command sequence number */
- uint32_t cmdsn;
- /** Expected status sequence number */
- uint32_t expstatsn;
- /** Fields specific to the PDU type */
- uint8_t other_d[16];
-};
-
-/**
- * iSCSI basic header segment common request fields
- *
- */
struct iscsi_bhs_common_response {
/** Opcode */
uint8_t opcode;
@@ -328,8 +301,16 @@ struct iscsi_bhs_scsi_response {
/** SCSI target failure */
#define ISCSI_RESPONSE_TARGET_FAILURE 0x01
+/** SCSI sense response code offset
+ *
+ * The SCSI response may contain unsolicited sense data in the data
+ * segment. If it does, this is the offset to the sense response code
+ * byte, which is the only byte we care about.
+ */
+#define ISCSI_SENSE_RESPONSE_CODE_OFFSET 2
+
/**
- * iSCSI data in basic header segment
+ * iSCSI data-in basic header segment
*
*/
struct iscsi_bhs_data_in {
@@ -363,7 +344,7 @@ struct iscsi_bhs_data_in {
uint32_t residual_count;
};
-/** Data in opcode */
+/** Data-in opcode */
#define ISCSI_OPCODE_DATA_IN 0x25
/** Data requires acknowledgement */
@@ -375,21 +356,94 @@ struct iscsi_bhs_data_in {
/** Data underflow occurred */
#define ISCSI_DATA_FLAG_UNDERFLOW 0x02
-/** SCSI status code and verflow/underflow flags are valid */
+/** SCSI status code and overflow/underflow flags are valid */
#define ISCSI_DATA_FLAG_STATUS 0x01
/**
+ * iSCSI data-out basic header segment
+ *
+ */
+struct iscsi_bhs_data_out {
+ /** Opcode */
+ uint8_t opcode;
+ /** Flags */
+ uint8_t flags;
+ /** Reserved */
+ uint16_t reserved_a;
+ /** Segment lengths */
+ union iscsi_segment_lengths lengths;
+ /** Logical Unit Number */
+ uint64_t lun;
+ /** Initiator Task Tag */
+ uint32_t itt;
+ /** Target Transfer Tag */
+ uint32_t ttt;
+ /** Reserved */
+ uint32_t reserved_b;
+ /** Expected status sequence number */
+ uint32_t expstatsn;
+ /** Reserved */
+ uint32_t reserved_c;
+ /** Data sequence number */
+ uint32_t datasn;
+ /** Buffer offset */
+ uint32_t offset;
+ /** Reserved */
+ uint32_t reserved_d;
+};
+
+/** Data-out opcode */
+#define ISCSI_OPCODE_DATA_OUT 0x05
+
+/**
+ * iSCSI request to transfer basic header segment
+ *
+ */
+struct iscsi_bhs_r2t {
+ /** Opcode */
+ uint8_t opcode;
+ /** Flags */
+ uint8_t flags;
+ /** Reserved */
+ uint16_t reserved_a;
+ /** Segment lengths */
+ union iscsi_segment_lengths lengths;
+ /** Logical Unit Number */
+ uint64_t lun;
+ /** Initiator Task Tag */
+ uint32_t itt;
+ /** Target Transfer Tag */
+ uint32_t ttt;
+ /** Status sequence number */
+ uint32_t statsn;
+ /** Expected command sequence number */
+ uint32_t expcmdsn;
+ /** Maximum command sequence number */
+ uint32_t maxcmdsn;
+ /** R2T sequence number */
+ uint32_t r2tsn;
+ /** Buffer offset */
+ uint32_t offset;
+ /** Desired data transfer length */
+ uint32_t len;
+};
+
+/** R2T opcode */
+#define ISCSI_OPCODE_R2T 0x31
+
+/**
* An iSCSI basic header segment
*/
union iscsi_bhs {
struct iscsi_bhs_common common;
- struct iscsi_bhs_common_request common_request;
struct iscsi_bhs_common_response common_response;
struct iscsi_bhs_login_request login_request;
struct iscsi_bhs_login_response login_response;
struct iscsi_bhs_scsi_command scsi_command;
struct iscsi_bhs_scsi_response scsi_response;
struct iscsi_bhs_data_in data_in;
+ struct iscsi_bhs_data_out data_out;
+ struct iscsi_bhs_r2t r2t;
unsigned char bytes[ sizeof ( struct iscsi_bhs_common ) ];
};
@@ -452,9 +506,29 @@ struct iscsi_session {
/** Initiator task tag
*
* This is the tag of the current command. It is incremented
- * whenever a final response PDU is received.
+ * whenever a new command is started.
*/
uint32_t itt;
+ /** Target transfer tag
+ *
+ * This is the tag attached to a sequence of data-out PDUs in
+ * response to an R2T.
+ */
+ uint32_t ttt;
+ /**
+ * Transfer offset
+ *
+ * This is the offset for an in-progress sequence of data-out
+ * PDUs in response to an R2T.
+ */
+ uint32_t transfer_offset;
+ /**
+ * Transfer length
+ *
+ * This is the length for an in-progress sequence of data-out
+ * PDUs in response to an R2T.
+ */
+ uint32_t transfer_len;
/** Command sequence number
*
* This is the sequence number of the current command, used to
diff --git a/src/include/gpxe/scsi.h b/src/include/gpxe/scsi.h
index db57e8913..dea39e162 100644
--- a/src/include/gpxe/scsi.h
+++ b/src/include/gpxe/scsi.h
@@ -136,6 +136,10 @@ struct scsi_command {
* Must be zero if @c data_in is NULL
*/
size_t data_in_len;
+ /** SCSI statua code */
+ uint8_t status;
+ /** SCSI sense response code */
+ uint8_t sense_response;
};
/** A SCSI device */
@@ -154,6 +158,12 @@ struct scsi_device {
* @v scsi SCSI device
* @v command SCSI command
* @ret rc Return status code
+ *
+ * Note that a successful return status code indicates only
+ * that the SCSI command completed. The caller must check the
+ * status field in the command structure to see if, for
+ * example, the device returned CHECK CONDITION or some other
+ * non-success status code.
*/
int ( * command ) ( struct scsi_device *scsi,
struct scsi_command *command );
diff --git a/src/net/tcp/iscsi.c b/src/net/tcp/iscsi.c
index 5c2966f44..c138d9b69 100644
--- a/src/net/tcp/iscsi.c
+++ b/src/net/tcp/iscsi.c
@@ -33,6 +33,8 @@
*/
static void iscsi_start_tx ( struct iscsi_session *iscsi );
+static void iscsi_start_data_out ( struct iscsi_session *iscsi,
+ unsigned int datasn );
/****************************************************************************
*
@@ -44,6 +46,11 @@ static void iscsi_start_tx ( struct iscsi_session *iscsi );
* Build iSCSI SCSI command BHS
*
* @v iscsi iSCSI session
+ *
+ * We don't currently support bidirectional commands (i.e. with both
+ * Data-In and Data-Out segments); these would require providing code
+ * to generate an AHS, and there doesn't seem to be any need for it at
+ * the moment.
*/
static void iscsi_start_command ( struct iscsi_session *iscsi ) {
struct iscsi_bhs_scsi_command *command = &iscsi->tx_bhs.scsi_command;
@@ -59,21 +66,49 @@ static void iscsi_start_command ( struct iscsi_session *iscsi ) {
command->flags |= ISCSI_COMMAND_FLAG_READ;
if ( iscsi->command->data_out )
command->flags |= ISCSI_COMMAND_FLAG_WRITE;
- ISCSI_SET_LENGTHS ( command->lengths, 0, iscsi->command->data_out_len);
+ /* lengths left as zero */
command->lun = iscsi->lun;
- command->itt = htonl ( iscsi->itt );
- command->exp_len = htonl ( iscsi->command->data_in_len );
+ command->itt = htonl ( ++iscsi->itt );
+ command->exp_len = htonl ( iscsi->command->data_in_len |
+ iscsi->command->data_out_len );
+ command->cmdsn = htonl ( iscsi->cmdsn );
+ command->expstatsn = htonl ( iscsi->statsn + 1 );
memcpy ( &command->cdb, &iscsi->command->cdb, sizeof ( command->cdb ));
}
/**
- * Send iSCSI SCSI command data
+ * Receive data segment of an iSCSI SCSI response PDU
*
* @v iscsi iSCSI session
+ * @v data Received data
+ * @v len Length of received data
+ * @v remaining Data remaining after this data
+ *
*/
-static void iscsi_tx_command ( struct iscsi_session *iscsi ) {
- tcp_send ( &iscsi->tcp, iscsi->command->data_out + iscsi->tx_offset,
- iscsi->command->data_out_len - iscsi->tx_offset );
+static void iscsi_rx_scsi_response ( struct iscsi_session *iscsi, void *data,
+ size_t len, size_t remaining ) {
+ struct iscsi_bhs_scsi_response *response
+ = &iscsi->rx_bhs.scsi_response;
+ int sense_offset;
+
+ /* Capture the sense response code as it floats past, if present */
+ sense_offset = ISCSI_SENSE_RESPONSE_CODE_OFFSET - iscsi->rx_offset;
+ if ( ( sense_offset >= 0 ) && len ) {
+ iscsi->command->sense_response =
+ * ( ( char * ) data + sense_offset );
+ }
+
+ /* Wait for whole SCSI response to arrive */
+ if ( remaining )
+ return;
+
+ /* Record SCSI status code */
+ iscsi->command->status = response->status;
+
+ /* Mark as completed, with error if applicable */
+ iscsi->status |= ISCSI_STATUS_DONE;
+ if ( response->response != ISCSI_RESPONSE_COMMAND_COMPLETE )
+ iscsi->status |= ISCSI_STATUS_ERR;
}
/**
@@ -86,7 +121,7 @@ static void iscsi_tx_command ( struct iscsi_session *iscsi ) {
*
*/
static void iscsi_rx_data_in ( struct iscsi_session *iscsi, void *data,
- size_t len, size_t remaining ) {
+ size_t len, size_t remaining __unused ) {
struct iscsi_bhs_data_in *data_in = &iscsi->rx_bhs.data_in;
unsigned long offset;
@@ -97,9 +132,109 @@ static void iscsi_rx_data_in ( struct iscsi_session *iscsi, void *data,
assert ( ( offset + len ) <= iscsi->command->data_in_len );
memcpy ( ( iscsi->command->data_in + offset ), data, len );
+ /* Record SCSI status, if present */
+ if ( data_in->flags & ISCSI_DATA_FLAG_STATUS )
+ iscsi->command->status = data_in->status;
+
/* If this is the end, flag as complete */
- if ( ( data_in->flags & ISCSI_FLAG_FINAL ) && ( remaining == 0 ) )
+ if ( ( offset + len ) == iscsi->command->data_in_len ) {
+ assert ( data_in->flags & ISCSI_FLAG_FINAL );
+ assert ( remaining == 0 );
iscsi->status |= ISCSI_STATUS_DONE;
+ }
+}
+
+/**
+ * Receive data segment of an iSCSI R2T PDU
+ *
+ * @v iscsi iSCSI session
+ * @v data Received data
+ * @v len Length of received data
+ * @v remaining Data remaining after this data
+ *
+ */
+static void iscsi_rx_r2t ( struct iscsi_session *iscsi, void *data __unused,
+ size_t len __unused, size_t remaining __unused ) {
+ struct iscsi_bhs_r2t *r2t = &iscsi->rx_bhs.r2t;
+
+ /* Record transfer parameters and trigger first data-out */
+ iscsi->ttt = ntohl ( r2t->ttt );
+ iscsi->transfer_offset = ntohl ( r2t->offset );
+ iscsi->transfer_len = ntohl ( r2t->len );
+ iscsi_start_data_out ( iscsi, 0 );
+}
+
+/**
+ * Build iSCSI data-out BHS
+ *
+ * @v iscsi iSCSI session
+ * @v datasn Data sequence number within the transfer
+ *
+ */
+static void iscsi_start_data_out ( struct iscsi_session *iscsi,
+ unsigned int datasn ) {
+ struct iscsi_bhs_data_out *data_out = &iscsi->tx_bhs.data_out;
+ unsigned long offset;
+ unsigned long remaining;
+ unsigned long len;
+
+ /* We always send 512-byte Data-Out PDUs; this removes the
+ * need to worry about the target's MaxRecvDataSegmentLength.
+ */
+ offset = datasn * 512;
+ remaining = iscsi->transfer_len - offset;
+ len = remaining;
+ if ( len > 512 )
+ len = 512;
+
+ /* Construct BHS and initiate transmission */
+ iscsi_start_tx ( iscsi );
+ data_out->opcode = ISCSI_OPCODE_DATA_OUT;
+ if ( len == remaining )
+ data_out->flags = ( ISCSI_FLAG_FINAL );
+ ISCSI_SET_LENGTHS ( data_out->lengths, 0, len );
+ data_out->lun = iscsi->lun;
+ data_out->itt = htonl ( iscsi->itt );
+ data_out->ttt = htonl ( iscsi->ttt );
+ data_out->expstatsn = htonl ( iscsi->statsn + 1 );
+ data_out->datasn = htonl ( datasn );
+ data_out->offset = htonl ( iscsi->transfer_offset + offset );
+}
+
+/**
+ * Complete iSCSI data-out PDU transmission
+ *
+ * @v iscsi iSCSI session
+ *
+ */
+static void iscsi_data_out_done ( struct iscsi_session *iscsi ) {
+ struct iscsi_bhs_data_out *data_out = &iscsi->tx_bhs.data_out;
+
+ /* If we haven't reached the end of the sequence, start
+ * sending the next data-out PDU.
+ */
+ if ( ! ( data_out->flags & ISCSI_FLAG_FINAL ) )
+ iscsi_start_data_out ( iscsi, ntohl ( data_out->datasn ) + 1 );
+}
+
+/**
+ * Send iSCSI data-out data segment
+ *
+ * @v iscsi iSCSI session
+ */
+static void iscsi_tx_data_out ( struct iscsi_session *iscsi ) {
+ struct iscsi_bhs_data_out *data_out = &iscsi->tx_bhs.data_out;
+ unsigned long offset;
+ unsigned long len;
+
+ offset = ( iscsi->transfer_offset + ntohl ( data_out->offset ) +
+ iscsi->tx_offset );
+ len = ( ISCSI_DATA_LEN ( data_out->lengths ) - iscsi->tx_offset );
+ assert ( iscsi->command != NULL );
+ assert ( iscsi->command->data_out != NULL );
+ assert ( ( offset + len ) <= iscsi->command->data_out_len );
+
+ tcp_send ( &iscsi->tcp, iscsi->command->data_out + offset, len );
}
/****************************************************************************
@@ -121,11 +256,11 @@ static int iscsi_build_login_request_strings ( struct iscsi_session *iscsi,
return snprintf ( data, len,
"InitiatorName=%s%c"
"TargetName=%s%c"
- "MaxRecvDataSegmentLength=512%c"
"SessionType=Normal%c"
"DataDigest=None%c"
"HeaderDigest=None%c"
- "ErrorRecoveryLevel=0%c",
+ "DefaultTime2Wait=0%c"
+ "DefaultTime2Retain=0%c",
iscsi->initiator, 0, iscsi->target, 0,
0, 0, 0, 0, 0 );
}
@@ -134,7 +269,7 @@ static int iscsi_build_login_request_strings ( struct iscsi_session *iscsi,
* Build iSCSI login request BHS
*
* @v iscsi iSCSI session
- * @v first Login request is the first request of a session
+ * @v first Login request is the first in a sequence
*/
static void iscsi_start_login ( struct iscsi_session *iscsi, int first ) {
struct iscsi_bhs_login_request *request = &iscsi->tx_bhs.login_request;
@@ -156,8 +291,12 @@ static void iscsi_start_login ( struct iscsi_session *iscsi, int first ) {
IANA_EN_FEN_SYSTEMS );
/* isid_iana_qual left as zero */
request->tsih = htons ( iscsi->tsih );
- /* itt left as zero */
+ if ( first )
+ iscsi->itt++;
+ request->itt = htonl ( iscsi->itt );
/* cid left as zero */
+ request->cmdsn = htonl ( iscsi->cmdsn );
+ request->expstatsn = htonl ( iscsi->statsn + 1 );
}
/**
@@ -240,8 +379,6 @@ static void iscsi_start_tx ( struct iscsi_session *iscsi ) {
/* Initialise TX BHS */
memset ( &iscsi->tx_bhs, 0, sizeof ( iscsi->tx_bhs ) );
- iscsi->tx_bhs.common_request.cmdsn = htonl ( iscsi->cmdsn );
- iscsi->tx_bhs.common_request.expstatsn = htonl ( iscsi->statsn + 1 );
/* Flag TX engine to start transmitting */
iscsi->tx_state = ISCSI_TX_BHS;
@@ -260,8 +397,8 @@ static void iscsi_tx_data ( struct iscsi_session *iscsi ) {
struct iscsi_bhs_common *common = &iscsi->tx_bhs.common;
switch ( common->opcode & ISCSI_OPCODE_MASK ) {
- case ISCSI_OPCODE_SCSI_COMMAND:
- iscsi_tx_command ( iscsi );
+ case ISCSI_OPCODE_DATA_OUT:
+ iscsi_tx_data_out ( iscsi );
break;
case ISCSI_OPCODE_LOGIN_REQUEST:
iscsi_tx_login_request ( iscsi );
@@ -273,6 +410,27 @@ static void iscsi_tx_data ( struct iscsi_session *iscsi ) {
}
/**
+ * Complete iSCSI PDU transmission
+ *
+ * @v iscsi iSCSI session
+ *
+ * Called when a PDU has been completely transmitted and the TX state
+ * machine is about to enter the idle state. iscsi::tx_bhs will be
+ * valid for the just-completed PDU when this is called.
+ */
+static void iscsi_tx_done ( struct iscsi_session *iscsi ) {
+ struct iscsi_bhs_common *common = &iscsi->tx_bhs.common;
+
+ switch ( common->opcode & ISCSI_OPCODE_MASK ) {
+ case ISCSI_OPCODE_DATA_OUT:
+ iscsi_data_out_done ( iscsi );
+ default:
+ /* No action */
+ break;
+ }
+}
+
+/**
* Handle TCP ACKs
*
* @v iscsi iSCSI session
@@ -318,9 +476,14 @@ static void iscsi_acked ( struct tcp_connection *conn, size_t len ) {
*/
if ( iscsi->tx_offset != max_tx_offset )
return;
-
+
+ /* Move to next state. Call iscsi_tx_done() when PDU
+ * transmission is complete.
+ */
iscsi->tx_state = next_state;
iscsi->tx_offset = 0;
+ if ( next_state == ISCSI_TX_IDLE )
+ iscsi_tx_done ( iscsi );
}
}
@@ -381,17 +544,19 @@ static void iscsi_rx_data ( struct iscsi_session *iscsi, void *data,
iscsi->cmdsn = ntohl ( response->expcmdsn );
iscsi->statsn = ntohl ( response->statsn );
- /* Increment itt when we receive a final response */
- if ( response->flags & ISCSI_FLAG_FINAL )
- iscsi->itt++;
-
switch ( response->opcode & ISCSI_OPCODE_MASK ) {
case ISCSI_OPCODE_LOGIN_RESPONSE:
iscsi_rx_login_response ( iscsi, data, len, remaining );
break;
+ case ISCSI_OPCODE_SCSI_RESPONSE:
+ iscsi_rx_scsi_response ( iscsi, data, len, remaining );
+ break;
case ISCSI_OPCODE_DATA_IN:
iscsi_rx_data_in ( iscsi, data, len, remaining );
break;
+ case ISCSI_OPCODE_R2T:
+ iscsi_rx_r2t ( iscsi, data, len, remaining );
+ break;
default:
printf ( "Unknown iSCSI opcode %02x\n", response->opcode );
iscsi->status |= ( ISCSI_STATUS_DONE | ISCSI_STATUS_ERR );
@@ -521,6 +686,7 @@ static void iscsi_closed ( struct tcp_connection *conn, int status __unused ) {
if ( ++iscsi->retry_count <= ISCSI_MAX_RETRIES ) {
tcp_connect ( conn );
} else {
+ printf ( "iSCSI retry count exceeded\n" );
iscsi->status |= ( ISCSI_STATUS_DONE | ISCSI_STATUS_ERR );
}
}
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2026-02-27 20:38:31 +0100