utilities: Add a GDB macro to dump any cmap structure.

Add a new GDB macro called ovs_dump_cmap, which can be used to dump any
cmap structure. Some examples:

(gdb) ovs_dump_cmap &subtable->rules
(struct cmap *) 0x3e02758

(gdb) ovs_dump_cmap &subtable->rules "struct dpcls_rule" cmap_node
(struct dpcls_rule *) 0x3e02758

(gdb) ovs_dump_cmap &subtable->rules "struct dpcls_rule" cmap_node dump
(struct dpcls_rule *) 0x3e02758 =
{cmap_node = {next = {p = 0x0}}, mask = 0x3dfe100, flow = {hash = ...

Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>

1 files changed, 66 insertions, 0 deletions

diff --git a/utilities/gdb/ovs_gdb.py b/utilities/gdb/ovs_gdb.py
index 763ece2a7..7f63dd0d5 100644
--- a/utilities/gdb/ovs_gdb.py
+++ b/utilities/gdb/ovs_gdb.py
@@ -850,6 +850,71 @@ class CmdDumpOvsList(gdb.Command):
 
 
 #
+# Implements the GDB "ovs_dump_cmap" command
+#
+class CmdDumpCmap(gdb.Command):
+    """Dump all nodes of a given cmap
+    Usage:
+      ovs_dump_cmap <struct cmap *> {[<structure>] [<member>] {dump}]}
+
+    For example dump all the rules in a dpcls_subtable:
+
+    (gdb) ovs_dump_cmap &subtable->rules
+    (struct cmap *) 0x3e02758
+
+    This is not very useful, so please use this with the container_of mode:
+
+    (gdb) ovs_dump_cmap &subtable->rules "struct dpcls_rule" cmap_node
+    (struct dpcls_rule *) 0x3e02758
+
+    Now you can manually use the print command to show the content, or use the
+    dump option to dump the structure for all nodes:
+
+    (gdb) ovs_dump_cmap &subtable->rules "struct dpcls_rule" cmap_node dump
+    (struct dpcls_rule *) 0x3e02758 =
+    {cmap_node = {next = {p = 0x0}}, mask = 0x3dfe100, flow = {hash = ...
+    """
+    def __init__(self):
+        super(CmdDumpCmap, self).__init__("ovs_dump_cmap",
+                                             gdb.COMMAND_DATA)
+
+    def invoke(self, arg, from_tty):
+        arg_list = gdb.string_to_argv(arg)
+        typeobj = None
+        member = None
+        dump = False
+
+        if len(arg_list) != 1 and len(arg_list) != 3 and len(arg_list) != 4:
+            print("usage: ovs_dump_cmap <struct cmap *> "
+                  "{[<structure>] [<member>] {dump}]}")
+            return
+
+        cmap = gdb.parse_and_eval(arg_list[0]).cast(
+            gdb.lookup_type('struct cmap').pointer())
+
+        if len(arg_list) >= 3:
+            typeobj = arg_list[1]
+            member = arg_list[2]
+            if len(arg_list) == 4 and arg_list[3] == "dump":
+                dump = True
+
+        for node in ForEachCMAP(cmap.dereference()):
+            if typeobj is None or member is None:
+                print("(struct cmap *) {}".format(node))
+            else:
+                print("({} *) {} {}".format(
+                    typeobj,
+                    container_of(node,
+                                 gdb.lookup_type(typeobj).pointer(), member),
+                    "=" if dump else ""))
+                if dump:
+                    print("  {}\n".format(container_of(
+                        node,
+                        gdb.lookup_type(typeobj).pointer(),
+                        member).dereference()))
+
+
+#
 # Implements the GDB "ovs_dump_simap" command
 #
 class CmdDumpSimap(gdb.Command):
@@ -1449,6 +1514,7 @@ CmdDumpNetdevProvider()
 CmdDumpOfpacts()
 CmdDumpOvsList()
 CmdDumpPackets()
+CmdDumpCmap()
 CmdDumpSimap()
 CmdDumpSmap()
 CmdDumpUdpifKeys()