Richard/iscsi

Makefile

@@ -33,4 +33,4 @@ drgn_tools/_version.py:
 .PHONY: rsync
 rsync: drgn_tools/_version.py
 	@if [ -z "$(TARGET)" ]; then echo "error: TARGET unspecified. Either set it in config.mk, or use\nmake TARGET=hostname rsync"; exit 1; fi
-	rsync -avz --exclude "__pycache__" --exclude ".git" --exclude ".mypy_cache" ./drgn_tools $(TARGET):drgn_tools/
+	rsync -avz --exclude "__pycache__" --exclude ".git" --exclude ".mypy_cache" ./drgn_tools $(TARGET)

drgn_tools/dm.py

@@ -26,14 +26,22 @@ def for_each_dm_hash(prog: Program) -> Iterable[Tuple[Object, str, str]]:
         for hc in list_for_each_entry(
             "struct hash_cell", head.address_of_(), "name_list"
         ):
-            yield hc.md, hc.name.string_().decode(), hc.uuid.string_().decode()
+            uuid = ""
+            if hc.uuid:
+                uuid = hc.uuid.string_().decode()
+
+            yield hc.md, hc.name.string_().decode(), uuid
 
 
 def for_each_dm_rbtree(prog: Program) -> Iterable[Tuple[Object, str, str]]:
     for hc in rbtree_inorder_for_each_entry(
         "struct hash_cell", prog["name_rb_tree"], "name_node"
     ):
-        yield hc.md, hc.name.string_().decode(), hc.uuid.string_().decode()
+        uuid = ""
+        if hc.uuid:
+            uuid = hc.uuid.string_().decode()
+
+        yield hc.md, hc.name.string_().decode(), uuid
 
 
 def for_each_dm(prog: Program) -> Iterable[Tuple[Object, str, str]]:

drgn_tools/iscsi.py

@@ -0,0 +1,185 @@
+# 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 drgn import container_of
+from drgn import Object
+from drgn import Program
+from drgn import sizeof
+from drgn.helpers.common import escape_ascii_string
+from drgn.helpers.linux.list import list_for_each_entry
+
+from drgn_tools.corelens import CorelensModule
+from drgn_tools.scsi import host_module_name
+from drgn_tools.table import print_dictionary
+from drgn_tools.table import print_table
+from drgn_tools.util import has_member
+
+
+def for_each_iscsi_device(prog: Program) -> Iterator[Object]:
+    """
+    Iterates through all iscsi devices and returns a
+    iterator.
+    :returns: a iterator of ``struct dev *``
+    """
+    class_in_private = prog.type("struct device_private").has_member(
+        "knode_class"
+    )
+
+    devices = Object(
+        prog,
+        "struct class",
+        address=prog["iscsi_host_class"].address_of_().value_(),
+    ).p.klist_devices.k_list.address_of_()
+
+    if class_in_private:
+        for device_private in list_for_each_entry(
+            "struct device_private", devices, "knode_class.n_node"
+        ):
+            yield device_private.device
+    else:
+        return list_for_each_entry(
+            "struct device", devices, "knode_class.n_node"
+        )
+
+
+def for_each_iscsi_host_device(prog: Program) -> Iterator[Object]:
+    """
+    Iterates through all iscsi devices and returns a
+    iterator of their host devices.
+    :returns: a iterator of ``struct dev *``
+    """
+    for dev in for_each_iscsi_device(prog):
+        while not (
+            dev.type and dev.type.name.string_().decode() == "scsi_host"
+        ):
+            if not dev.parent:
+                break
+            dev = dev.parent
+
+        if dev.type and dev.type.name.string_().decode() == "scsi_host":
+            yield dev
+
+
+def for_each_scsi_host(prog: Program) -> Iterator[Object]:
+    """
+    Iterates through all iscsi host devices and returns a
+    iterator of their hosts.
+    :returns: a iterator of ``struct Scsi_Host *``
+    """
+    for dev in for_each_iscsi_host_device(prog):
+        yield container_of(dev, "struct Scsi_Host", "shost_gendev")
+
+
+def for_each_iscsi_session(prog: Program) -> Iterator[Object]:
+    """
+    Iterates through all iscsi hosts and returns a
+    iterator of their associated sessions.
+    :returns: a iterator of ``struct iscsi_session *``
+
+    """
+    for h in for_each_scsi_host(prog):
+        yield __get_iscsi_session(prog, h)
+
+
+def __get_iscsi_session(prog: Program, Scsi_Host: Object) -> Object:
+    """
+    Get the associated session given the scsi host.
+    returns: ``struct iscsi_session *``
+    """
+    iscsi_sw_tcp_host_addr = (
+        Scsi_Host.value_()
+        + sizeof(prog.type("struct Scsi_Host"))
+        + sizeof(prog.type("struct iscsi_host"))
+    )
+    iscsi_sw_tcp_host = Object(
+        prog, "struct iscsi_sw_tcp_host", address=iscsi_sw_tcp_host_addr
+    )
+
+    return iscsi_sw_tcp_host.session
+
+
+def print_iscsi_table(prog: Program) -> None:
+    """
+    Prints basic iscsi information
+    """
+    output = [
+        [
+            "SCSI_HOST",
+            "NAME",
+            "DRIVER",
+            "Busy",
+            "Blocked",
+            "Fail",
+            "State",
+            "ISCSI_SESSION",
+        ]
+    ]
+    for shost in for_each_scsi_host(prog):
+        """
+        Since 6eb045e092ef ("scsi: core: avoid host-wide host_busy counter for scsi_mq"),
+        host_busy is no longer a member of struct Scsi_Host.
+        """
+        if has_member(shost, "host_busy"):
+            host_busy = shost.host_busy.counter.value_()
+        else:
+            host_busy = "n/a"
+        output.append(
+            [
+                hex(shost.value_()),
+                f"host{shost.host_no.value_()}",
+                host_module_name(shost),
+                host_busy,
+                shost.host_blocked.counter.value_(),
+                shost.host_failed.value_(),
+                shost.shost_state.format_(type_name=False),
+                hex(__get_iscsi_session(prog, shost).value_()),
+            ]
+        )
+    print_table(output)
+
+
+def print_iscsi_report(prog) -> None:
+    """
+    Prints a comprehensive report including iscsi table and session stats. More info can be added later if needed.
+    """
+    print_iscsi_table(prog)
+    print()
+    output = {}
+
+    for session in 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["Session"] = hex(session.value_())
+        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["Initiatorname"] = escape_ascii_string(
+            session.initiatorname.string_()
+        )
+        output["Targetname"] = escape_ascii_string(
+            session.targetname.string_()
+        )
+
+        print_dictionary(output)
+        print()
+
+
+class IscsiDump(CorelensModule):
+    """
+    Dump iscsi info
+    """
+
+    name = "iscsi"
+
+    def run(self, prog: Program, args: argparse.Namespace) -> None:
+        print_iscsi_report(prog)

tests/test_iscsi.py

@@ -0,0 +1,7 @@
+# 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
+
+
+def test_iscsi(prog):
+    iscsi.print_iscsi_report(prog)