[Qemu-devel] [PATCH 04/14] ./block/iscsi/discovery.c

[ronniesahlberg]

From: Ronnie Sahlberg <address@hidden>

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 <address@hidden>
---
 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 <address@hidden>
+
+   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