targetcli: dump iscsi and vhost info as in targetcli

Orabug: 37301968
Signed-off-by: Richard Li <[email protected]>

Author: richl9

drgn_tools/targetcli.py

@@ -0,0 +1,292 @@
+# Copyright (c) 2025, Oracle and/or its affiliates.
+# Licensed under the Universal Permissive License v 1.0 as shown at https://oss.oracle.com/licenses/upl/
+"""
+Helpers to retrieve iscsi target info and reconstruct targetcli structure on iscsi target server.
+
+Configuration could be found under /sys/kernel/config/target/
+"""
+import argparse
+from typing import Iterable
+
+from drgn import FaultError
+from drgn import Object
+from drgn import Program
+from drgn.helpers.linux.list import hlist_for_each_entry
+from drgn.helpers.linux.list import list_for_each_entry
+
+from drgn_tools.corelens import CorelensModule
+from drgn_tools.module import ensure_debuginfo
+
+######################################
+# iscsi
+######################################
+
+
+def for_each_iqn(prog: Program) -> Iterable[Object]:
+    """
+    List tiqn from g_tiqn_list
+
+    :returns: Iterator of ``struct iscsi_tiqn *``
+    """
+    tiqn_list = prog["g_tiqn_list"]
+
+    return list_for_each_entry(
+        "struct iscsi_tiqn", tiqn_list.address_of_(), "tiqn_list"
+    )
+
+
+def for_each_iscsi_tpg(tiqn: Object) -> Iterable[Object]:
+    """
+    Get a list of tpg from tiqn
+
+    :param tiqn: ``struct iscsi_tiqn *``
+    :returns: Iterator of ``struct iscsi_portal_group *``
+    """
+    return list_for_each_entry(
+        "struct iscsi_portal_group",
+        tiqn.tiqn_tpg_list.address_of_(),
+        "tpg_list",
+    )
+
+
+def print_iscsi_info(prog) -> None:
+    """Dump iscsi section info"""
+
+    msg = ensure_debuginfo(prog, ["target_core_mod", "iscsi_target_mod"])
+    if msg:
+        print(msg)
+        return
+
+    print("o- iscsi")
+    indent = "  "
+    for tiqn in for_each_iqn(prog):
+        print(
+            "{}o- {} (struct iscsi_tiqn * {})".format(
+                indent,
+                get_tiqn_name(tiqn),
+                hex(tiqn.value_()),
+            )
+        )
+
+        for tpg in for_each_iscsi_tpg(tiqn):
+            se_tpg = tpg.tpg_se_tpg
+            print(
+                "{}o- {} (struct se_portal_group {})".format(
+                    indent * 2,
+                    get_tpg_name(se_tpg),
+                    hex(se_tpg.address_of_()),
+                )
+            )
+            print(f"{indent * 3}o- acls")
+            for acl in list_for_each_entry(
+                "struct se_node_acl",
+                se_tpg.acl_node_list.address_of_(),
+                "acl_list",
+            ):
+                print(
+                    "{}o- {} (struct se_node_acl * {})".format(
+                        indent * 4,
+                        get_acl_name(acl),
+                        hex(acl),
+                    )
+                )
+                print(f"{indent * 4}o- mapped_luns")
+                for se_dev in hlist_for_each_entry(
+                    "struct se_dev_entry",
+                    acl.lun_entry_hlist.address_of_(),
+                    "link",
+                ):
+                    print_lun_info(se_dev.se_lun, nr_indent=5)
+
+            print(f"{indent * 3}o- luns")
+            for lun in hlist_for_each_entry(
+                "struct se_lun",
+                se_tpg.tpg_lun_hlist.address_of_(),
+                "link",
+            ):
+                print_lun_info(lun, nr_indent=4)
+
+
+######################################
+# vhost
+######################################
+
+
+def for_each_vhost_tpg(prog) -> Iterable[Object]:
+    """
+    List vhost_scsi_tpg from vhost_scsi_list
+
+    :returns: Iterator of ``struct vhost_scsi_tpg *``
+    """
+
+    vhost_scsi_list = prog["vhost_scsi_list"]
+
+    return list_for_each_entry(
+        "struct vhost_scsi_tpg", vhost_scsi_list.address_of_(), "tv_tpg_list"
+    )
+
+
+def print_vhost_info(prog) -> None:
+    """Dump vhost section info"""
+
+    msg = ensure_debuginfo(prog, ["vhost", "vhost_scsi", "target_core_mod"])
+    if msg:
+        print(msg)
+        return
+
+    print("o- vhost")
+    for tpg in for_each_vhost_tpg(prog):
+        indent = "  "
+        se_tpg = tpg.se_tpg
+        print(
+            "{}o- {} (struct se_portal_group {}) ({})".format(
+                indent,
+                get_tpg_name(se_tpg),
+                hex(se_tpg.address_of_()),
+                get_ci_name_from_cg(tpg.tport.tport_wwn.wwn_group),
+            )
+        )
+
+        print(f"{indent * 2}o- acls")
+        for acl in list_for_each_entry(
+            "struct se_node_acl",
+            se_tpg.acl_node_list.address_of_(),
+            "acl_list",
+        ):
+            acl_name = get_acl_name(acl)
+            if not acl_name:
+                continue
+
+            print(
+                "{}o- {} (struct se_node_acl * {})".format(
+                    indent * 3,
+                    acl_name,
+                    hex(acl),
+                )
+            )
+
+            print(f"{indent * 3}o- mapped_luns")
+            for se_dev in hlist_for_each_entry(
+                "struct se_dev_entry",
+                acl.lun_entry_hlist.address_of_(),
+                "link",
+            ):
+                print_lun_info(se_dev.se_lun, nr_indent=4)
+
+        print(f"{indent * 2}o- luns")
+        for lun in hlist_for_each_entry(
+            "struct se_lun", se_tpg.tpg_lun_hlist.address_of_(), "link"
+        ):
+            print_lun_info(lun, nr_indent=3)
+
+
+def print_lun_info(lun: Object, nr_indent: int = 1) -> None:
+    """
+    Dump lun info
+
+    :param lun: ``struct se_lun *``
+    :param nr_indent: int indicating numbers of indentations
+    """
+    print(
+        "{}o- {} (struct se_lun * {}) \n{}o- BACKSTORE: {} \n{}o- DEVICE: {}".format(
+            "  " * nr_indent,
+            get_lun_name(lun),
+            hex(lun),
+            "  " * (nr_indent + 1),
+            get_backstore_name_from_lun(lun),
+            "  " * (nr_indent + 1),
+            get_device_path_from_lun(lun),
+        )
+    )
+
+
+def get_ci_name_from_cg(cg: Object) -> str:
+    """
+    Get ci_name given a config group
+
+    :param cg: ``struct config_group *``
+    :returns: str
+    """
+    try:
+        return cg.cg_item.ci_name.string_().decode()
+    except FaultError:
+        return ""
+
+
+def get_backstore_name_from_lun(lun: Object) -> str:
+    """
+    Get backstore name given a lun
+
+    :param lun: ``struct se_lun *``
+    :returns: str
+    """
+    return get_ci_name_from_cg(lun.lun_se_dev.dev_group)
+
+
+def get_tpg_name(tpg: Object) -> str:
+    """
+    Get tpg name
+
+    :param tpg: ``struct se_portal_group``
+    :returns: str
+    """
+    return get_ci_name_from_cg(tpg.tpg_group)
+
+
+def get_acl_name(acl: Object) -> str:
+    """
+    Get acl name. If the name is empty, it could mean the acl is not configured or potentially corrupted.
+
+    :param acl: ``struct se_node_acl *``
+    :returns: str
+    """
+    return get_ci_name_from_cg(acl.acl_group)
+
+
+def get_tiqn_name(tiqn: Object) -> str:
+    """
+    Get tiqn name
+
+    :param tiqn: ``struct iscsi_tiqn *``
+    :returns: str
+    """
+    return tiqn.tiqn.string_().decode()
+
+
+def get_lun_name(lun: Object) -> str:
+    """
+    Get lun name
+
+    :param lun: ``struct se_lun *``
+    :returns: str
+    """
+    return get_ci_name_from_cg(lun.lun_group)
+
+
+def get_device_path_from_lun(lun: Object) -> str:
+    """
+    Get block backend device path given lun
+
+    :param lun: ``struct se_lun *``
+    :returns: str
+    """
+    return lun.lun_se_dev.udev_path.string_().decode()
+
+
+def dump_targetcli(prog) -> None:
+    """Dump targetcli structure"""
+
+    print_iscsi_info(prog)
+    print_vhost_info(prog)
+
+
+class TargetCli(CorelensModule):
+    """
+    Dump targetcli structure on iscsi target
+    """
+
+    name = "targetcli"
+    skip_unless_have_kmod = ["target_core_mod"]
+
+    def run(self, prog: Program, args: argparse.Namespace) -> None:
+        dump_targetcli(prog)

tests/test_targetcli.py

@@ -0,0 +1,7 @@
+# Copyright (c) 2025, Oracle and/or its affiliates.
+# Licensed under the Universal Permissive License v 1.0 as shown at https://oss.oracle.com/licenses/upl/
+from drgn_tools import targetcli
+
+
+def test_targetcli(prog):
+    targetcli.dump_targetcli(prog)