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- /*
- * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
- *
- * 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 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, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- */
-
- #include <stddef.h>
- #include <string.h>
- #include <vsprintf.h>
- #include <errno.h>
- #include <assert.h>
- #include <byteswap.h>
- #include <gpxe/scsi.h>
- #include <gpxe/process.h>
- #include <gpxe/iscsi.h>
-
- /** @file
- *
- * iSCSI protocol
- *
- */
-
- static void iscsi_start_tx ( struct iscsi_session *iscsi );
-
- /****************************************************************************
- *
- * iSCSI SCSI command issuing
- *
- */
-
- /**
- * Build iSCSI SCSI command BHS
- *
- * @v iscsi iSCSI session
- */
- static void iscsi_start_command ( struct iscsi_session *iscsi ) {
- struct iscsi_bhs_scsi_command *command = &iscsi->tx_bhs.scsi_command;
-
- assert ( ! ( iscsi->command->data_in && iscsi->command->data_out ) );
-
- /* Construct BHS and initiate transmission */
- iscsi_start_tx ( iscsi );
- command->opcode = ISCSI_OPCODE_SCSI_COMMAND;
- command->flags = ( ISCSI_FLAG_FINAL |
- ISCSI_COMMAND_ATTR_SIMPLE );
- if ( iscsi->command->data_in )
- 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);
- command->lun = iscsi->lun;
- command->itt = htonl ( iscsi->itt );
- command->exp_len = htonl ( iscsi->command->data_in_len );
- memcpy ( &command->cdb, &iscsi->command->cdb, sizeof ( command->cdb ));
- }
-
- /**
- * Send iSCSI SCSI command data
- *
- * @v iscsi iSCSI session
- */
- 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 );
- }
-
- /**
- * Receive data segment of an iSCSI data-in 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_data_in ( struct iscsi_session *iscsi, void *data,
- size_t len, size_t remaining ) {
- struct iscsi_bhs_data_in *data_in = &iscsi->rx_bhs.data_in;
- unsigned long offset;
-
- /* Copy data to data-in buffer */
- offset = ntohl ( data_in->offset ) + iscsi->rx_offset;
- assert ( iscsi->command != NULL );
- assert ( iscsi->command->data_in != NULL );
- assert ( ( offset + len ) <= iscsi->command->data_in_len );
- memcpy ( ( iscsi->command->data_in + offset ), data, len );
-
- /* If this is the end, flag as complete */
- if ( ( data_in->flags & ISCSI_FLAG_FINAL ) && ( remaining == 0 ) )
- iscsi->status |= ISCSI_STATUS_DONE;
- }
-
- /****************************************************************************
- *
- * iSCSI login
- *
- */
-
- /**
- * Build iSCSI login request strings
- *
- * @v iscsi iSCSI session
- *
- * These are the initial set of strings sent in the first login
- * request PDU.
- */
- static int iscsi_build_login_request_strings ( struct iscsi_session *iscsi,
- void *data, size_t len ) {
- 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",
- iscsi->initiator, 0, iscsi->target, 0,
- 0, 0, 0, 0, 0 );
- }
-
- /**
- * Build iSCSI login request BHS
- *
- * @v iscsi iSCSI session
- * @v first Login request is the first request of a session
- */
- static void iscsi_start_login ( struct iscsi_session *iscsi, int first ) {
- struct iscsi_bhs_login_request *request = &iscsi->tx_bhs.login_request;
- int len;
-
- /* Construct BHS and initiate transmission */
- iscsi_start_tx ( iscsi );
- request->opcode = ( ISCSI_OPCODE_LOGIN_REQUEST |
- ISCSI_FLAG_IMMEDIATE );
- request->flags = ( ISCSI_LOGIN_FLAG_TRANSITION |
- ISCSI_LOGIN_CSG_OPERATIONAL_NEGOTIATION |
- ISCSI_LOGIN_NSG_FULL_FEATURE_PHASE );
- /* version_max and version_min left as zero */
- if ( first ) {
- len = iscsi_build_login_request_strings ( iscsi, NULL, 0 );
- ISCSI_SET_LENGTHS ( request->lengths, 0, len );
- }
- request->isid_iana_en = htonl ( ISCSI_ISID_IANA |
- IANA_EN_FEN_SYSTEMS );
- /* isid_iana_qual left as zero */
- request->tsih = htons ( iscsi->tsih );
- /* itt left as zero */
- /* cid left as zero */
- }
-
- /**
- * Transmit data segment of an iSCSI login request PDU
- *
- * @v iscsi iSCSI session
- *
- * For login requests, the data segment consists of the login strings.
- */
- static void iscsi_tx_login_request ( struct iscsi_session *iscsi ) {
- int len;
-
- len = iscsi_build_login_request_strings ( iscsi, tcp_buffer,
- tcp_buflen );
- tcp_send ( &iscsi->tcp, tcp_buffer + iscsi->tx_offset,
- len - iscsi->tx_offset );
- }
-
- /**
- * Receive data segment of an iSCSI login 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_rx_login_response ( struct iscsi_session *iscsi,
- void *data __unused,
- size_t len __unused,
- size_t remaining __unused ) {
- struct iscsi_bhs_login_response *response
- = &iscsi->rx_bhs.login_response;
-
- /* Check for fatal errors */
- if ( response->status_class != 0 ) {
- printf ( "iSCSI login failure: class %02x detail %02x\n",
- response->status_class, response->status_detail );
- iscsi->status |= ( ISCSI_STATUS_DONE | ISCSI_STATUS_ERR );
- tcp_close ( &iscsi->tcp );
- return;
- }
-
- /* If server did not transition, send back another login
- * request without any login strings.
- */
- if ( ! ( response->flags & ISCSI_LOGIN_FLAG_TRANSITION ) ) {
- iscsi_start_login ( iscsi, 0 );
- return;
- }
-
- /* Record TSIH for future reference */
- iscsi->tsih = ntohl ( response->tsih );
-
- /* Send the SCSI command */
- iscsi_start_command ( iscsi );
- }
-
- /****************************************************************************
- *
- * iSCSI to TCP interface
- *
- */
-
- static inline struct iscsi_session *
- tcp_to_iscsi ( struct tcp_connection *conn ) {
- return container_of ( conn, struct iscsi_session, tcp );
- }
-
- /**
- * Start up a new TX PDU
- *
- * @v iscsi iSCSI session
- *
- * This initiates the process of sending a new PDU. Only one PDU may
- * be in transit at any one time.
- */
- static void iscsi_start_tx ( struct iscsi_session *iscsi ) {
- assert ( iscsi->tx_state == ISCSI_TX_IDLE );
-
- /* 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;
- iscsi->tx_offset = 0;
- }
-
- /**
- * Transmit data segment of an iSCSI PDU
- *
- * @v iscsi iSCSI session
- *
- * Handle transmission of part of a PDU data segment. iscsi::tx_bhs
- * will be valid when this is called.
- */
- 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 );
- break;
- case ISCSI_OPCODE_LOGIN_REQUEST:
- iscsi_tx_login_request ( iscsi );
- break;
- default:
- assert ( 0 );
- break;
- }
- }
-
- /**
- * Handle TCP ACKs
- *
- * @v iscsi iSCSI session
- *
- * Updates iscsi->tx_offset and, if applicable, transitions to the
- * next TX state.
- */
- static void iscsi_acked ( struct tcp_connection *conn, size_t len ) {
- struct iscsi_session *iscsi = tcp_to_iscsi ( conn );
- struct iscsi_bhs_common *common = &iscsi->tx_bhs.common;
- size_t max_tx_offset;
- enum iscsi_tx_state next_state;
-
- iscsi->tx_offset += len;
- while ( 1 ) {
- switch ( iscsi->tx_state ) {
- case ISCSI_TX_BHS:
- max_tx_offset = sizeof ( iscsi->tx_bhs );
- next_state = ISCSI_TX_AHS;
- break;
- case ISCSI_TX_AHS:
- max_tx_offset = 4 * ISCSI_AHS_LEN ( common->lengths );
- next_state = ISCSI_TX_DATA;
- break;
- case ISCSI_TX_DATA:
- max_tx_offset = ISCSI_DATA_LEN ( common->lengths );
- next_state = ISCSI_TX_DATA_PADDING;
- break;
- case ISCSI_TX_DATA_PADDING:
- max_tx_offset = ISCSI_DATA_PAD_LEN ( common->lengths );
- next_state = ISCSI_TX_IDLE;
- break;
- case ISCSI_TX_IDLE:
- return;
- default:
- assert ( 0 );
- return;
- }
- assert ( iscsi->tx_offset <= max_tx_offset );
-
- /* If the whole of the current portion has not yet
- * been acked, stay in this state for now.
- */
- if ( iscsi->tx_offset != max_tx_offset )
- return;
-
- iscsi->tx_state = next_state;
- iscsi->tx_offset = 0;
- }
- }
-
- /**
- * Transmit iSCSI PDU
- *
- * @v iscsi iSCSI session
- *
- * Constructs data to be sent for the current TX state
- */
- static void iscsi_senddata ( struct tcp_connection *conn ) {
- struct iscsi_session *iscsi = tcp_to_iscsi ( conn );
- struct iscsi_bhs_common *common = &iscsi->tx_bhs.common;
- static const char pad[] = { '\0', '\0', '\0' };
-
- switch ( iscsi->tx_state ) {
- case ISCSI_TX_IDLE:
- /* Nothing to send */
- break;
- case ISCSI_TX_BHS:
- tcp_send ( conn, &iscsi->tx_bhs.bytes[iscsi->tx_offset],
- ( sizeof ( iscsi->tx_bhs ) - iscsi->tx_offset ) );
- break;
- case ISCSI_TX_AHS:
- /* We don't yet have an AHS transmission mechanism */
- assert ( 0 );
- break;
- case ISCSI_TX_DATA:
- iscsi_tx_data ( iscsi );
- break;
- case ISCSI_TX_DATA_PADDING:
- tcp_send ( conn, pad, ( ISCSI_DATA_PAD_LEN ( common->lengths )
- - iscsi->tx_offset ) );
- break;
- default:
- assert ( 0 );
- break;
- }
- }
-
- /**
- * Receive data segment of an iSCSI PDU
- *
- * @v iscsi iSCSI session
- * @v data Received data
- * @v len Length of received data
- * @v remaining Data remaining after this data
- *
- * Handle processing of part of a PDU data segment. iscsi::rx_bhs
- * will be valid when this is called.
- */
- static void iscsi_rx_data ( struct iscsi_session *iscsi, void *data,
- size_t len, size_t remaining ) {
- struct iscsi_bhs_common_response *response
- = &iscsi->rx_bhs.common_response;
-
- /* Update cmdsn and statsn */
- 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_DATA_IN:
- iscsi_rx_data_in ( iscsi, data, len, remaining );
- break;
- default:
- printf ( "Unknown iSCSI opcode %02x\n", response->opcode );
- iscsi->status |= ( ISCSI_STATUS_DONE | ISCSI_STATUS_ERR );
- break;
- }
- }
-
- /**
- * Discard portion of an iSCSI PDU.
- *
- * @v iscsi iSCSI session
- * @v data Received data
- * @v len Length of received data
- * @v remaining Data remaining after this data
- *
- * This discards data from a portion of a received PDU.
- */
- static void iscsi_rx_discard ( struct iscsi_session *iscsi __unused,
- void *data __unused, size_t len __unused,
- size_t remaining __unused ) {
- /* Do nothing */
- }
-
- /**
- * Receive basic header segment of an iSCSI PDU
- *
- * @v iscsi iSCSI session
- * @v data Received data
- * @v len Length of received data
- * @v remaining Data remaining after this data
- *
- * This fills in iscsi::rx_bhs with the data from the BHS portion of
- * the received PDU.
- */
- static void iscsi_rx_bhs ( struct iscsi_session *iscsi, void *data,
- size_t len, size_t remaining __unused ) {
- memcpy ( &iscsi->rx_bhs.bytes[iscsi->rx_offset], data, len );
- }
-
- /**
- * Receive new data
- *
- * @v tcp TCP connection
- * @v data Received data
- * @v len Length of received data
- *
- * This handles received PDUs. The receive strategy is to fill in
- * iscsi::rx_bhs with the contents of the BHS portion of the PDU,
- * throw away any AHS portion, and then process each part of the data
- * portion as it arrives. The data processing routine therefore
- * always has a full copy of the BHS available, even for portions of
- * the data in different packets to the BHS.
- */
- static void iscsi_newdata ( struct tcp_connection *conn, void *data,
- size_t len ) {
- struct iscsi_session *iscsi = tcp_to_iscsi ( conn );
- struct iscsi_bhs_common *common = &iscsi->rx_bhs.common;
- void ( *process ) ( struct iscsi_session *iscsi, void *data,
- size_t len, size_t remaining );
- size_t max_rx_offset;
- enum iscsi_rx_state next_state;
- size_t frag_len;
- size_t remaining;
-
- while ( 1 ) {
- switch ( iscsi->rx_state ) {
- case ISCSI_RX_BHS:
- process = iscsi_rx_bhs;
- max_rx_offset = sizeof ( iscsi->rx_bhs );
- next_state = ISCSI_RX_AHS;
- break;
- case ISCSI_RX_AHS:
- process = iscsi_rx_discard;
- max_rx_offset = 4 * ISCSI_AHS_LEN ( common->lengths );
- next_state = ISCSI_RX_DATA;
- break;
- case ISCSI_RX_DATA:
- process = iscsi_rx_data;
- max_rx_offset = ISCSI_DATA_LEN ( common->lengths );
- next_state = ISCSI_RX_DATA_PADDING;
- break;
- case ISCSI_RX_DATA_PADDING:
- process = iscsi_rx_discard;
- max_rx_offset = ISCSI_DATA_PAD_LEN ( common->lengths );
- next_state = ISCSI_RX_BHS;
- break;
- default:
- assert ( 0 );
- return;
- }
-
- frag_len = max_rx_offset - iscsi->rx_offset;
- if ( frag_len > len )
- frag_len = len;
- remaining = max_rx_offset - iscsi->rx_offset - frag_len;
- process ( iscsi, data, frag_len, remaining );
-
- iscsi->rx_offset += frag_len;
- data += frag_len;
- len -= frag_len;
-
- /* If all the data for this state has not yet been
- * received, stay in this state for now.
- */
- if ( iscsi->rx_offset != max_rx_offset )
- return;
-
- iscsi->rx_state = next_state;
- iscsi->rx_offset = 0;
- }
- }
-
- /**
- * Handle TCP connection closure
- *
- * @v conn TCP connection
- * @v status Error code, if any
- *
- */
- static void iscsi_closed ( struct tcp_connection *conn, int status __unused ) {
- struct iscsi_session *iscsi = tcp_to_iscsi ( conn );
-
- /* Clear connected flag */
- iscsi->status &= ~ISCSI_STATUS_CONNECTED;
-
- /* Retry connection if within the retry limit, otherwise fail */
- if ( ++iscsi->retry_count <= ISCSI_MAX_RETRIES ) {
- tcp_connect ( conn );
- } else {
- iscsi->status |= ( ISCSI_STATUS_DONE | ISCSI_STATUS_ERR );
- }
- }
-
- /**
- * Handle TCP connection opening
- *
- * @v conn TCP connection
- *
- */
- static void iscsi_connected ( struct tcp_connection *conn ) {
- struct iscsi_session *iscsi = tcp_to_iscsi ( conn );
-
- /* Set connected flag and reset retry count */
- iscsi->status |= ISCSI_STATUS_CONNECTED;
- iscsi->retry_count = 0;
-
- /* Prepare to receive PDUs. */
- iscsi->rx_state = ISCSI_RX_BHS;
- iscsi->rx_offset = 0;
-
- /* Start logging in */
- iscsi_start_login ( iscsi, 1 );
- }
-
- /** iSCSI TCP operations */
- static struct tcp_operations iscsi_tcp_operations = {
- .closed = iscsi_closed,
- .connected = iscsi_connected,
- .acked = iscsi_acked,
- .newdata = iscsi_newdata,
- .senddata = iscsi_senddata,
- };
-
- /**
- * Issue SCSI command via iSCSI session
- *
- * @v iscsi iSCSI session
- * @v command SCSI command
- * @ret rc Return status code
- */
- int iscsi_issue ( struct iscsi_session *iscsi,
- struct scsi_command *command ) {
- iscsi->command = command;
- iscsi->status &= ~( ISCSI_STATUS_DONE | ISCSI_STATUS_ERR );
-
- if ( iscsi->status & ISCSI_STATUS_CONNECTED ) {
- iscsi_start_command ( iscsi );
- } else {
- iscsi->tcp.tcp_op = &iscsi_tcp_operations;
- tcp_connect ( &iscsi->tcp );
- }
-
- while ( ! ( iscsi->status & ISCSI_STATUS_DONE ) ) {
- step();
- }
-
- iscsi->command = NULL;
-
- return ( ( iscsi->status & ISCSI_STATUS_ERR ) ? -EIO : 0 );
- }
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