Commit f9dadc98 authored by Ronnie Sahlberg's avatar Ronnie Sahlberg Committed by Kevin Wolf
Browse files

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: default avatarRonnie Sahlberg <ronniesahlberg@gmail.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 71b58b82

block/iscsi.c

+129 −10
Original line number Diff line number Diff line
@@ -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);

    }

qemu-config.c

+27 −0
Original line number Diff line number Diff line
@@ -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,

};

qemu-doc.texi

+53 −1
Original line number Diff line number Diff line
@@ -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

qemu-options.hx

+12 −4
Original line number Diff line number Diff line
@@ -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

vl.c

+8 −0
Original line number Diff line number Diff line
@@ -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;