diff options
Diffstat (limited to 'src/server/iscsi.c')
| -rw-r--r-- | src/server/iscsi.c | 74 |
1 files changed, 45 insertions, 29 deletions
diff --git a/src/server/iscsi.c b/src/server/iscsi.c index b7aacec..8546284 100644 --- a/src/server/iscsi.c +++ b/src/server/iscsi.c @@ -2851,41 +2851,40 @@ static int iscsi_connection_handle_task_func_req(iscsi_connection *conn, const i } /** - * @brief Handles an incoming iSCSI payload data NOP-Out request PDU. + * @brief Handles receiving and sending of NOP in/out packets. * - * This function handles NOP-Out request payload - * data sent by the client.\n - * If a response needs to be sent, this will - * be done as well. + * This method can handle a received NOP-Out request and send + * an according NOP-In response if applicable, i.e. the NOP-Out + * wasn't sent as a reply to a NOP-In by us.\n + * This method can also send an unsolicited NOP-In to the client + * if we want to check whether the connection is still good. * * @param[in] conn Pointer to iSCSI connection to handle. May * NOT be NULL, so take caution. - * @param[in] request_pdu Pointer to iSCSI client request PDU to handle. - * May be NULL in which case an error is returned. + * @param[in] request_pdu Pointer to iSCSI client request PDU to handle, + * or NULL for sending a connection alive check. * @return 0 on success. A negative value indicates - * an error. A positive value a warning. + * an error. */ -static int iscsi_connection_handle_nop_out(iscsi_connection *conn, const iscsi_pdu *request_pdu) +static int iscsi_connection_handle_nop(iscsi_connection *conn, const iscsi_pdu *request_pdu) { if ( conn->state != ISCSI_CONNECT_STATE_NORMAL_SESSION ) return ISCSI_CONNECT_PDU_READ_ERR_FATAL; - if ( request_pdu->ds_len > ISCSI_DEFAULT_MAX_RECV_DS_LEN ) + if ( request_pdu != NULL && request_pdu->ds_len > ISCSI_DEFAULT_MAX_RECV_DS_LEN ) return iscsi_connection_handle_reject( conn, request_pdu, ISCSI_REJECT_REASON_PROTOCOL_ERR ); - iscsi_nop_out_packet *nop_out_pkt = (iscsi_nop_out_packet *) request_pdu->bhs_pkt; - const uint32_t target_xfer_tag = iscsi_get_be32(nop_out_pkt->target_xfer_tag); - uint32_t ds_len = request_pdu->ds_len; - const uint64_t lun = iscsi_get_be64(nop_out_pkt->lun); + iscsi_nop_out_packet *nop_out_pkt = request_pdu == NULL ? NULL : (iscsi_nop_out_packet *) request_pdu->bhs_pkt; + const uint32_t target_xfer_tag = nop_out_pkt == NULL ? 0xFFFFFFFFUL : iscsi_get_be32(nop_out_pkt->target_xfer_tag); + const uint32_t init_task_tag = nop_out_pkt == NULL ? 0 : iscsi_get_be32(nop_out_pkt->init_task_tag); + uint32_t ds_len = request_pdu == NULL ? 0 : request_pdu->ds_len; + const uint64_t lun = nop_out_pkt == NULL ? 0 : iscsi_get_be64(nop_out_pkt->lun); - if ( nop_out_pkt->init_task_tag == 0xFFFFFFFFUL ) // Was response to a NOP by us - do not reply + if ( init_task_tag == 0xFFFFFFFFUL ) // Was response to a NOP by us, or no response desired - do not reply return ISCSI_CONNECT_PDU_READ_OK; - if ( (target_xfer_tag != 0xFFFFFFFFUL) && (target_xfer_tag != (uint32_t) conn->id) ) - return iscsi_connection_handle_reject( conn, request_pdu, ISCSI_REJECT_REASON_INVALID_PDU_FIELD ); // TODO: Check if this is the correct error code. - - if ( (nop_out_pkt->init_task_tag == 0xFFFFFFFFUL) && (nop_out_pkt->opcode & ISCSI_OPCODE_FLAGS_IMMEDIATE) == 0 ) - return ISCSI_CONNECT_PDU_READ_ERR_FATAL; + if ( target_xfer_tag != 0xFFFFFFFFUL ) // If the initiator tag is not the special value, the target tag has to be. + return iscsi_connection_handle_reject( conn, request_pdu, ISCSI_REJECT_REASON_INVALID_PDU_FIELD ); if ( ds_len > (uint32_t)conn->opts.MaxRecvDataSegmentLength ) ds_len = conn->opts.MaxRecvDataSegmentLength; @@ -2897,15 +2896,23 @@ static int iscsi_connection_handle_nop_out(iscsi_connection *conn, const iscsi_p iscsi_nop_in_packet *nop_in_pkt = (iscsi_nop_in_packet *) response_pdu.bhs_pkt; nop_in_pkt->opcode = ISCSI_OPCODE_SERVER_NOP_IN; - nop_in_pkt->flags = -0x80; + nop_in_pkt->flags = 0x80; nop_in_pkt->reserved = 0U; iscsi_put_be32( (uint8_t *) &nop_in_pkt->total_ahs_len, ds_len ); // TotalAHSLength is always 0 and DataSegmentLength is 24-bit, so write in one step. iscsi_put_be64( (uint8_t *) &nop_in_pkt->lun, lun ); - nop_in_pkt->target_xfer_tag = 0xFFFFFFFFUL; // Minus one does not require endianess conversion - nop_in_pkt->init_task_tag = nop_out_pkt->init_task_tag; // Copyed from request packet, no endian conversion required - iscsi_put_be32( (uint8_t *) &nop_in_pkt->stat_sn, conn->stat_sn++ ); + if ( nop_out_pkt == NULL ) { + // Send a request which needs a reply, set target tag to anything but the special value + nop_in_pkt->init_task_tag = 0xFFFFFFFFUL; + nop_in_pkt->target_xfer_tag = 0; + iscsi_put_be32( (uint8_t *) &nop_in_pkt->stat_sn, conn->stat_sn ); // Don't inc + } else { + // This is a reply, set target tag to special value to indicate we don't want a NOP-Out in response + iscsi_put_be32( (uint8_t *) &nop_in_pkt->init_task_tag, init_task_tag ); + nop_in_pkt->target_xfer_tag = 0xFFFFFFFFUL; + iscsi_put_be32( (uint8_t *) &nop_in_pkt->stat_sn, conn->stat_sn++ ); // Inc + } - if ( (nop_out_pkt->opcode & ISCSI_OPCODE_FLAGS_IMMEDIATE) == 0 ) + if ( nop_out_pkt == NULL || (nop_out_pkt->opcode & ISCSI_OPCODE_FLAGS_IMMEDIATE) == 0 ) conn->max_cmd_sn++; iscsi_put_be32( (uint8_t *) &nop_in_pkt->exp_cmd_sn, conn->exp_cmd_sn ); @@ -3366,7 +3373,7 @@ static int iscsi_connection_pdu_handle(iscsi_connection *conn, iscsi_pdu *reques switch ( opcode ) { case ISCSI_OPCODE_CLIENT_NOP_OUT : { - rc = iscsi_connection_handle_nop_out( conn, request_pdu ); + rc = iscsi_connection_handle_nop( conn, request_pdu ); break; } @@ -3422,6 +3429,7 @@ static int iscsi_connection_pdu_handle(iscsi_connection *conn, iscsi_pdu *reques */ static void iscsi_connection_pdu_read_loop(iscsi_connection *conn, const dnbd3_request_t *request, const int len) { + ssize_t ret; iscsi_pdu CLEANUP_PDU request_pdu; if ( !iscsi_connection_pdu_init( &request_pdu, 0, false ) ) @@ -3483,8 +3491,17 @@ static void iscsi_connection_pdu_read_loop(iscsi_connection *conn, const dnbd3_r // header before the loop - this saves us from accounting for this within the mainloop // 1) Receive entire BHS - if ( sock_recv( conn->client->sock, request_pdu.bhs_pkt, sizeof(iscsi_bhs_packet) ) != sizeof(iscsi_bhs_packet) ) { - logadd( LOG_INFO, "Cannot receive BHS for client %s", conn->client->hostName ); + ret = sock_recv( conn->client->sock, request_pdu.bhs_pkt, sizeof(iscsi_bhs_packet) ); + if ( ret == -1 && errno == EAGAIN ) { + // Receive timeout - send a NOP-In and try recv one more time + if ( iscsi_connection_handle_nop( conn, NULL ) != ISCSI_CONNECT_PDU_READ_OK ) { + logadd( LOG_DEBUG1, "Cannot send NOP-In to idle client %s - connection dead", conn->client->hostName ); + break; + } + ret = sock_recv( conn->client->sock, request_pdu.bhs_pkt, sizeof(iscsi_bhs_packet) ); + } + if ( ret != sizeof(iscsi_bhs_packet) ) { + logadd( LOG_DEBUG1, "Cannot receive BHS for client %s (%d/%d)", conn->client->hostName, (int)ret, (int)errno ); break; } } while ( !_shutdown ); @@ -3508,7 +3525,6 @@ void iscsi_connection_handle(dnbd3_client_t *client, const dnbd3_request_t *requ { _Static_assert( sizeof(dnbd3_request_t) <= sizeof(iscsi_bhs_packet), "DNBD3 request size larger than iSCSI BHS packet data size - Manual intervention required!" ); - sock_setTimeout( client->sock, 1000L * 3600L ); // TODO: Remove after finishing iSCSI implementation iscsi_connection *conn = iscsi_connection_create( client ); |