From: Ronnie Sahlberg <ronniesahlb...@gmail.com> iscsi client library : discovery.c This file contains functions for managing discovery sessions used by iscsi clients to discover which targets may be present behind a particular iscsi portal.
... ./block/iscsi/ contains a copy of a general purpose iscsi client library which is aimed at providing a clientside api for iscsi for both qemu/kvm as well as otther scsi related utilities. As such, there is need to make merging across various consumers, qemu/kvm being one of many here, as easy as possible when features are added to the library. As such, no consumer/qemu specific code is used in this library as well as coding guidelined might not be adhered to 100% It is the intention that this library will be useful for many and that iscsi use spawned from this will flourish. Signed-off-by: Ronnie Sahlberg <ronniesahlb...@gmail.com> --- block/iscsi/discovery.c | 191 +++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 191 insertions(+), 0 deletions(-) create mode 100644 block/iscsi/discovery.c diff --git a/block/iscsi/discovery.c b/block/iscsi/discovery.c new file mode 100644 index 0000000..3ea3d74 --- /dev/null +++ b/block/iscsi/discovery.c @@ -0,0 +1,191 @@ +/* + Copyright (C) 2010 by Ronnie Sahlberg <ronniesahlb...@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 <string.h> +#include <arpa/inet.h> +#include "iscsi.h" +#include "iscsi-private.h" + +int +iscsi_discovery_async(struct iscsi_context *iscsi, iscsi_command_cb cb, + void *private_data) +{ + struct iscsi_pdu *pdu; + char *str; + + if (iscsi->session_type != ISCSI_SESSION_DISCOVERY) { + iscsi_set_error(iscsi, "Trying to do discovery on " + "non-discovery session."); + return -1; + } + + pdu = iscsi_allocate_pdu(iscsi, ISCSI_PDU_TEXT_REQUEST, + ISCSI_PDU_TEXT_RESPONSE); + if (pdu == NULL) { + iscsi_set_error(iscsi, "Out-of-memory: Failed to allocate " + "text pdu."); + return -2; + } + + /* immediate */ + iscsi_pdu_set_immediate(pdu); + + /* flags */ + iscsi_pdu_set_pduflags(pdu, ISCSI_PDU_TEXT_FINAL); + + /* target transfer tag */ + iscsi_pdu_set_ttt(pdu, 0xffffffff); + + /* sendtargets */ + str = (char *)"SendTargets=All"; + if (iscsi_pdu_add_data(iscsi, pdu, (unsigned char *)str, strlen(str)+1) + != 0) { + iscsi_set_error(iscsi, "Out-of-memory: pdu add data failed."); + iscsi_free_pdu(iscsi, pdu); + return -3; + } + + pdu->callback = cb; + pdu->private_data = private_data; + + if (iscsi_queue_pdu(iscsi, pdu) != 0) { + iscsi_set_error(iscsi, "Out-of-memory: failed to queue iscsi " + "text pdu."); + iscsi_free_pdu(iscsi, pdu); + return -4; + } + + return 0; +} + +static void +iscsi_free_discovery_addresses(struct iscsi_discovery_address *addresses) +{ + while (addresses != NULL) { + struct iscsi_discovery_address *next = addresses->next; + + if (addresses->target_name != NULL) { + free(discard_const(addresses->target_name)); + addresses->target_name = NULL; + } + if (addresses->target_address != NULL) { + free(discard_const(addresses->target_address)); + addresses->target_address = NULL; + } + addresses->next = NULL; + free(addresses); + addresses = next; + } +} + +int +iscsi_process_text_reply(struct iscsi_context *iscsi, struct iscsi_pdu *pdu, + const unsigned char *hdr, int size) +{ + struct iscsi_discovery_address *targets = NULL; + + /* verify the response looks sane */ + if (hdr[1] != ISCSI_PDU_TEXT_FINAL) { + iscsi_set_error(iscsi, "unsupported flags in text " + "reply %02x\n", hdr[1]); + pdu->callback(iscsi, SCSI_STATUS_ERROR, NULL, + pdu->private_data); + return -1; + } + + /* skip past the header */ + hdr += ISCSI_HEADER_SIZE; + size -= ISCSI_HEADER_SIZE; + + while (size > 0) { + int len; + + len = strlen((char *)hdr); + + if (len == 0) { + break; + } + + if (len > size) { + iscsi_set_error(iscsi, "len > size when parsing " + "discovery data %d>%d\n", len, size); + pdu->callback(iscsi, SCSI_STATUS_ERROR, NULL, + pdu->private_data); + iscsi_free_discovery_addresses(targets); + return -1; + } + + /* parse the strings */ + if (!strncmp((char *)hdr, "TargetName=", 11)) { + struct iscsi_discovery_address *target; + + target = malloc(sizeof(struct iscsi_discovery_address)); + if (target == NULL) { + iscsi_set_error(iscsi, "Failed to allocate " + "data for new discovered " + "target\n"); + pdu->callback(iscsi, SCSI_STATUS_ERROR, NULL, + pdu->private_data); + iscsi_free_discovery_addresses(targets); + return -1; + } + bzero(target, sizeof(struct iscsi_discovery_address)); + target->target_name = strdup((char *)hdr+11); + if (target->target_name == NULL) { + iscsi_set_error(iscsi, "Failed to allocate " + "data for new discovered " + "target name\n"); + pdu->callback(iscsi, SCSI_STATUS_ERROR, NULL, + pdu->private_data); + free(target); + target = NULL; + iscsi_free_discovery_addresses(targets); + return -1; + } + target->next = targets; + targets = target; + } else if (!strncmp((char *)hdr, "TargetAddress=", 14)) { + targets->target_address = strdup((char *)hdr+14); + if (targets->target_address == NULL) { + iscsi_set_error(iscsi, "Failed to allocate " + "data for new discovered " + "target address\n"); + pdu->callback(iscsi, SCSI_STATUS_ERROR, NULL, + pdu->private_data); + iscsi_free_discovery_addresses(targets); + return -1; + } + } else { + iscsi_set_error(iscsi, "Dont know how to handle " + "discovery string : %s\n", hdr); + pdu->callback(iscsi, SCSI_STATUS_ERROR, NULL, + pdu->private_data); + iscsi_free_discovery_addresses(targets); + return -1; + } + + hdr += len + 1; + size -= len + 1; + } + + pdu->callback(iscsi, SCSI_STATUS_GOOD, targets, pdu->private_data); + iscsi_free_discovery_addresses(targets); + + return 0; +} -- 1.7.3.1
