Add iscsi helpers to dump iscsi session

Orabug: 37362180
Signed-off-by: Richard Li <[email protected]>

drgn_tools/iscsi.py

@@ -0,0 +1,149 @@
+# Copyright (c) 2024, Oracle and/or its affiliates.
+# Licensed under the Universal Permissive License v 1.0 as shown at https://oss.oracle.com/licenses/upl/
+"""
+Helper for iscsi
+"""
+import argparse
+from typing import Iterator
+from typing import Tuple
+
+from drgn import Object
+from drgn import Program
+from drgn.helpers.common import escape_ascii_string
+from drgn.helpers.common.type import enum_type_to_class
+from drgn.helpers.linux.list import list_for_each_entry
+
+from drgn_tools.corelens import CorelensModule
+from drgn_tools.scsi import for_each_scsi_host
+from drgn_tools.scsi import for_each_scsi_host_device
+from drgn_tools.scsi import get_scsi_device_name
+from drgn_tools.scsi import host_module_name
+from drgn_tools.table import print_dictionary
+from drgn_tools.util import enum_name_get
+
+ISCSI_SESSION_STATES = ["LOGGED_IN", "FAILED", "FREE"]
+
+
+def for_each_iscsi_host(prog: Program) -> Iterator[Object]:
+    """
+    Iterates through all scsi host devices and returns a
+    iterator of hosts backed by iscsi drivers
+    :returns: an iterator of ``struct Scsi_Host *``
+    """
+    for shost in for_each_scsi_host(prog):
+        if "iscsi" in host_module_name(shost).lower():
+            yield shost
+
+
+def for_each_iscsi_session(prog: Program) -> Iterator[Object]:
+    """
+    Iterates through all iscsi_cls_session and gets the associated iscsi_session
+    :returns: an iterator of ``struct iscsi_session *``
+
+    """
+    for cls_session in list_for_each_entry(
+        "struct iscsi_cls_session", prog["sesslist"].address_of_(), "sess_list"
+    ):
+        yield Object(
+            prog,
+            prog.type("struct iscsi_session", filename="libiscsi.h"),
+            address=cls_session.dd_data,
+        )
+
+
+def for_each_attached_device(
+    prog: Program, shost: Object
+) -> Iterator[Tuple[Object, str]]:
+    """
+    Iterates through all Scsi_Host and gets their associated scsi device and name
+    :returns: an iterator of (``struct scsi_device *``, ``str``)
+
+    """
+    for scsi_dev in for_each_scsi_host_device(prog, shost):
+        name = get_scsi_device_name(prog, scsi_dev)
+        yield scsi_dev, name
+
+
+def print_iscsi_report(prog: Program) -> None:
+    """
+    Prints a comprehensive report including iscsi table and session stats. More info can be added later if needed.
+    """
+    output = {}
+
+    for session in reversed(list(for_each_iscsi_session(prog))):
+        print("**********")
+        conn = session.leadconn
+
+        persistent_address = escape_ascii_string(
+            conn.persistent_address.string_()
+        )
+        persistent_port = int(conn.persistent_port)
+        output[
+            "Scsi_Host"
+        ] = f"host{session.host.host_no.value_()} ({hex(session.host.value_())})"
+        output["Session"] = hex(session.address_of_())
+        output["SID"] = str(int(session.cls_session.sid))
+        output["Persistent Portal"] = f"{persistent_address}:{persistent_port}"
+        output["Iface Name"] = escape_ascii_string(session.ifacename.string_())
+        output["Session State"] = ISCSI_SESSION_STATES[
+            session.cls_session.state
+        ]
+        connstate = enum_type_to_class(
+            prog.type("enum iscsi_connection_state"), "connstate"
+        )
+        output["Connection State"] = str(
+            enum_name_get(
+                connstate,
+                conn.cls_conn.state,
+                "UNKNOWN",
+            )
+        )
+        output["Initiatorname"] = escape_ascii_string(
+            session.initiatorname.string_()
+        )
+        output["Targetname"] = escape_ascii_string(
+            session.targetname.string_()
+        )
+
+        print_dictionary(output)
+
+        print("Attached SCSI devices: ")
+        print("**********")
+        print(
+            "Host Number: {}  STATE: {}".format(
+                session.host.host_no.value_(),
+                session.host.shost_state.format_(type_name=False),
+            )
+        )
+
+        for scsi_dev, name in for_each_attached_device(prog, session.host):
+            print(
+                "scsi{} Channel {} Id {} Lun: {}".format(
+                    session.host.host_no.value_(),
+                    int(scsi_dev.channel),
+                    int(scsi_dev.id),
+                    int(scsi_dev.lun),
+                )
+            )
+            sdev_state = enum_type_to_class(
+                prog.type("enum scsi_device_state"), "sdev_state"
+            )
+            state = enum_name_get(
+                sdev_state,
+                scsi_dev.sdev_state,
+                "UNKNOWN",
+            )
+            print("  Attached iscsi disk: {}  State: {}".format(name, state))
+
+        print()
+
+
+class IscsiDump(CorelensModule):
+    """
+    Dump iscsi info
+    """
+
+    name = "iscsi"
+
+    def run(self, prog: Program, args: argparse.Namespace) -> None:
+        print_iscsi_report(prog)

drgn_tools/scsi.py

@@ -56,6 +56,28 @@ def host_module_name(shost: Object) -> str:
     return name
 
 
+def for_each_scsi_host_device(
+    prog: Program, shost: Object
+) -> Iterator[Object]:
+    """
+    Get a list of scsi_devices asscociated with an Scsi_Host
+    :returns: a iterator of ``struct scsi_device``
+    """
+    return list_for_each_entry(
+        "struct scsi_device", shost.__devices.address_of_(), "siblings"
+    )
+
+
+def get_scsi_device_name(prog: Program, sdev: Object) -> str:
+    """
+    Get the device name associated with scsi_device.
+    :return ``str``
+    """
+    rq = sdev.request_queue
+    dev = container_of(rq.kobj.parent, "struct device", "kobj")
+    return dev.kobj.name.string_().decode()
+
+
 def print_scsi_hosts(prog: Program) -> None:
     """
     Prints scsi host information

tests/test_iscsi.py

@@ -0,0 +1,11 @@
+# Copyright (c) 2024, 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 iscsi
+from drgn_tools.module import KernelModule
+
+
+def test_iscsi(prog):
+    # make sure iscsi module is loaded
+    km = KernelModule.find(prog, "scsi_transport_iscsi")
+    if km:
+        iscsi.print_iscsi_report(prog)