iSCSI: add configuration variables for iSCSI

This patch adds configuration variables for iSCSI to set
initiator-name to use when logging in to the target,
which type of header-digest to negotiate with the target
and username and password for CHAP authentication.

This allows specifying a initiator-name either from the command line
-iscsi initiator-name=iqn.2004-01.com.example:test
or from a configuration file included with -readconfig
    [iscsi]
      initiator-name = iqn.2004-01.com.example:test
      header-digest = CRC32C|CRC32C-NONE|NONE-CRC32C|NONE
      user = CHAP username
      password = CHAP password

If you use several different targets, you can also configure this on a per
target basis by using a group name:
    [iscsi "iqn.target.name"]
    ...

The configuration file can be read using -readconfig.
Example :
qemu-system-i386 -drive file=iscsi://127.0.0.1/iqn.ronnie.test/1
 -readconfig iscsi.conf

Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Ronnie Sahlberg 2012-01-26 09:39:02 +11:00 committed by Kevin Wolf
parent 71b58b82da
commit f9dadc9855
5 changed files with 229 additions and 15 deletions

View File

@ -455,6 +455,109 @@ iscsi_connect_cb(struct iscsi_context *iscsi, int status, void *command_data,
}
}
static int parse_chap(struct iscsi_context *iscsi, const char *target)
{
QemuOptsList *list;
QemuOpts *opts;
const char *user = NULL;
const char *password = NULL;
list = qemu_find_opts("iscsi");
if (!list) {
return 0;
}
opts = qemu_opts_find(list, target);
if (opts == NULL) {
opts = QTAILQ_FIRST(&list->head);
if (!opts) {
return 0;
}
}
user = qemu_opt_get(opts, "user");
if (!user) {
return 0;
}
password = qemu_opt_get(opts, "password");
if (!password) {
error_report("CHAP username specified but no password was given");
return -1;
}
if (iscsi_set_initiator_username_pwd(iscsi, user, password)) {
error_report("Failed to set initiator username and password");
return -1;
}
return 0;
}
static void parse_header_digest(struct iscsi_context *iscsi, const char *target)
{
QemuOptsList *list;
QemuOpts *opts;
const char *digest = NULL;
list = qemu_find_opts("iscsi");
if (!list) {
return;
}
opts = qemu_opts_find(list, target);
if (opts == NULL) {
opts = QTAILQ_FIRST(&list->head);
if (!opts) {
return;
}
}
digest = qemu_opt_get(opts, "header-digest");
if (!digest) {
return;
}
if (!strcmp(digest, "CRC32C")) {
iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_CRC32C);
} else if (!strcmp(digest, "NONE")) {
iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_NONE);
} else if (!strcmp(digest, "CRC32C-NONE")) {
iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_CRC32C_NONE);
} else if (!strcmp(digest, "NONE-CRC32C")) {
iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_NONE_CRC32C);
} else {
error_report("Invalid header-digest setting : %s", digest);
}
}
static char *parse_initiator_name(const char *target)
{
QemuOptsList *list;
QemuOpts *opts;
const char *name = NULL;
list = qemu_find_opts("iscsi");
if (!list) {
return g_strdup("iqn.2008-11.org.linux-kvm");
}
opts = qemu_opts_find(list, target);
if (opts == NULL) {
opts = QTAILQ_FIRST(&list->head);
if (!opts) {
return g_strdup("iqn.2008-11.org.linux-kvm");
}
}
name = qemu_opt_get(opts, "initiator-name");
if (!name) {
return g_strdup("iqn.2008-11.org.linux-kvm");
}
return g_strdup(name);
}
/*
* We support iscsi url's on the form
* iscsi://[<username>%<password>@]<host>[:<port>]/<targetname>/<lun>
@ -465,6 +568,7 @@ static int iscsi_open(BlockDriverState *bs, const char *filename, int flags)
struct iscsi_context *iscsi = NULL;
struct iscsi_url *iscsi_url = NULL;
struct IscsiTask task;
char *initiator_name = NULL;
int ret;
if ((BDRV_SECTOR_SIZE % 512) != 0) {
@ -474,16 +578,6 @@ static int iscsi_open(BlockDriverState *bs, const char *filename, int flags)
return -EINVAL;
}
memset(iscsilun, 0, sizeof(IscsiLun));
/* Should really append the KVM name after the ':' here */
iscsi = iscsi_create_context("iqn.2008-11.org.linux-kvm:");
if (iscsi == NULL) {
error_report("iSCSI: Failed to create iSCSI context.");
ret = -ENOMEM;
goto failed;
}
iscsi_url = iscsi_parse_full_url(iscsi, filename);
if (iscsi_url == NULL) {
error_report("Failed to parse URL : %s %s", filename,
@ -492,6 +586,17 @@ static int iscsi_open(BlockDriverState *bs, const char *filename, int flags)
goto failed;
}
memset(iscsilun, 0, sizeof(IscsiLun));
initiator_name = parse_initiator_name(iscsi_url->target);
iscsi = iscsi_create_context(initiator_name);
if (iscsi == NULL) {
error_report("iSCSI: Failed to create iSCSI context.");
ret = -ENOMEM;
goto failed;
}
if (iscsi_set_targetname(iscsi, iscsi_url->target)) {
error_report("iSCSI: Failed to set target name.");
ret = -EINVAL;
@ -507,6 +612,14 @@ static int iscsi_open(BlockDriverState *bs, const char *filename, int flags)
goto failed;
}
}
/* check if we got CHAP username/password via the options */
if (parse_chap(iscsi, iscsi_url->target) != 0) {
error_report("iSCSI: Failed to set CHAP user/password");
ret = -EINVAL;
goto failed;
}
if (iscsi_set_session_type(iscsi, ISCSI_SESSION_NORMAL) != 0) {
error_report("iSCSI: Failed to set session type to normal.");
ret = -EINVAL;
@ -515,6 +628,9 @@ static int iscsi_open(BlockDriverState *bs, const char *filename, int flags)
iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_NONE_CRC32C);
/* check if we got HEADER_DIGEST via the options */
parse_header_digest(iscsi, iscsi_url->target);
task.iscsilun = iscsilun;
task.status = 0;
task.complete = 0;
@ -548,6 +664,9 @@ static int iscsi_open(BlockDriverState *bs, const char *filename, int flags)
return 0;
failed:
if (initiator_name != NULL) {
g_free(initiator_name);
}
if (iscsi_url != NULL) {
iscsi_destroy_url(iscsi_url);
}

View File

@ -118,6 +118,32 @@ static QemuOptsList qemu_drive_opts = {
},
};
static QemuOptsList qemu_iscsi_opts = {
.name = "iscsi",
.head = QTAILQ_HEAD_INITIALIZER(qemu_iscsi_opts.head),
.desc = {
{
.name = "user",
.type = QEMU_OPT_STRING,
.help = "username for CHAP authentication to target",
},{
.name = "password",
.type = QEMU_OPT_STRING,
.help = "password for CHAP authentication to target",
},{
.name = "header-digest",
.type = QEMU_OPT_STRING,
.help = "HeaderDigest setting. "
"{CRC32C|CRC32C-NONE|NONE-CRC32C|NONE}",
},{
.name = "initiator-name",
.type = QEMU_OPT_STRING,
.help = "Initiator iqn name to use when connecting",
},
{ /* end of list */ }
},
};
static QemuOptsList qemu_chardev_opts = {
.name = "chardev",
.implied_opt_name = "backend",
@ -580,6 +606,7 @@ static QemuOptsList *vm_config_groups[32] = {
&qemu_option_rom_opts,
&qemu_machine_opts,
&qemu_boot_opts,
&qemu_iscsi_opts,
NULL,
};

View File

@ -730,6 +730,57 @@ export LIBISCSI_CHAP_PASSWORD=<password>
iscsi://<host>/<target-iqn-name>/<lun>
@end example
Various session related parameters can be set via special options, either
in a configuration file provided via '-readconfig' or directly on the
command line.
@example
Setting a specific initiator name to use when logging in to the target
-iscsi initiator-name=iqn.qemu.test:my-initiator
@end example
@example
Controlling which type of header digest to negotiate with the target
-iscsi header-digest=CRC32C|CRC32C-NONE|NONE-CRC32C|NONE
@end example
These can also be set via a configuration file
@example
[iscsi]
user = "CHAP username"
password = "CHAP password"
initiator-name = "iqn.qemu.test:my-initiator"
# header digest is one of CRC32C|CRC32C-NONE|NONE-CRC32C|NONE
header-digest = "CRC32C"
@end example
Setting the target name allows different options for different targets
@example
[iscsi "iqn.target.name"]
user = "CHAP username"
password = "CHAP password"
initiator-name = "iqn.qemu.test:my-initiator"
# header digest is one of CRC32C|CRC32C-NONE|NONE-CRC32C|NONE
header-digest = "CRC32C"
@end example
Howto use a configuration file to set iSCSI configuration options:
@example
cat >iscsi.conf <<EOF
[iscsi]
user = "me"
password = "my password"
initiator-name = "iqn.qemu.test:my-initiator"
header-digest = "CRC32C"
EOF
qemu-system-i386 -drive file=iscsi://127.0.0.1/iqn.qemu.test/1 \
-readconfig iscsi.conf
@end example
Howto set up a simple iSCSI target on loopback and accessing it via QEMU:
@example
This example shows how to set up an iSCSI target with one CDROM and one DISK
@ -744,7 +795,8 @@ tgtadm --lld iscsi --mode logicalunit --op new --tid 1 --lun 2 \
-b /IMAGES/cd.iso --device-type=cd
tgtadm --lld iscsi --op bind --mode target --tid 1 -I ALL
qemu-system-i386 -boot d -drive file=iscsi://127.0.0.1/iqn.qemu.test/1 \
qemu-system-i386 -iscsi initiator-name=iqn.qemu.test:my-initiator \
-boot d -drive file=iscsi://127.0.0.1/iqn.qemu.test/1 \
-cdrom iscsi://127.0.0.1/iqn.qemu.test/2
@end example

View File

@ -1829,24 +1829,32 @@ Syntax for specifying iSCSI LUNs is
Example (without authentication):
@example
qemu -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \
--drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
qemu -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \
-cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \
-drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
@end example
Example (CHAP username/password via URL):
@example
qemu --drive file=iscsi://user%password@@192.0.2.1/iqn.2001-04.com.example/1
qemu -drive file=iscsi://user%password@@192.0.2.1/iqn.2001-04.com.example/1
@end example
Example (CHAP username/password via environment variables):
@example
LIBISCSI_CHAP_USERNAME="user" \
LIBISCSI_CHAP_PASSWORD="password" \
qemu --drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
qemu -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
@end example
iSCSI support is an optional feature of QEMU and only available when
compiled and linked against libiscsi.
ETEXI
DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi,
"-iscsi [user=user][,password=password]\n"
" [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
" [,initiator-name=iqn]\n"
" iSCSI session parameters\n", QEMU_ARCH_ALL)
STEXI
@item NBD
QEMU supports NBD (Network Block Devices) both using TCP protocol as well

8
vl.c
View File

@ -2529,6 +2529,14 @@ int main(int argc, char **argv, char **envp)
exit(1);
}
break;
#ifdef CONFIG_LIBISCSI
case QEMU_OPTION_iscsi:
opts = qemu_opts_parse(qemu_find_opts("iscsi"), optarg, 0);
if (!opts) {
exit(1);
}
break;
#endif
#ifdef CONFIG_SLIRP
case QEMU_OPTION_tftp:
legacy_tftp_prefix = optarg;