[PATCH pynfs 3/3] itm: add a handler that truncates READDIR response page data

[Benjamin Coddington <bcodding@redhat.com>]

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
---
 itm/handlers/readdir_reply_nopages.py |   86 +++++++++++++++++++++++++++++++++
 1 files changed, 86 insertions(+), 0 deletions(-)
 create mode 100644 itm/handlers/readdir_reply_nopages.py

diff --git a/itm/handlers/readdir_reply_nopages.py b/itm/handlers/readdir_reply_nopages.py
new file mode 100644
index 0000000..e5dd91e
--- /dev/null
+++ b/itm/handlers/readdir_reply_nopages.py
@@ -0,0 +1,86 @@
+from rpc_const import *
+from xdrdef.nfs4_const import *
+from xdrdef.nfs4_type import *
+from xdrdef.nfs3_const import *
+from xdrdef.nfs3_type import *
+from xdrdef.nfs3_pack import NFS3Packer, NFS3Unpacker
+from nfs4commoncode import encode_status_by_name
+from itm.handlers import BaseHandler
+
+import itm
+import nfs4lib
+
+"""
+   This handler modifies the response body for a v4 READDIR call
+   or v3 READDIRPLUS call such that there are no pages of data in
+   the response.
+
+   https://bugzilla.redhat.com/show_bug.cgi?id=1182830
+   http://marc.info/?l=linux-nfs&m=142964061807798&w=2
+   ce85cfb NFS: Don't attempt to decode missing directory entries
+"""
+
+class Handler(BaseHandler):
+
+	def will_handle(self, cb_info):
+
+		# setup for v4:
+		if hasattr(cb_info, "v4_res"):
+			res = cb_info.v4_res;
+			my_ops = filter(lambda x: x.resop == OP_READDIR, res.resarray)
+			if not my_ops:
+				return 0;
+
+			# save the resop for handle()
+			self.my_resop = my_ops[0]
+			return 1;
+
+		# setup for v3:
+		msg = cb_info.rpc_msg
+		if msg.body.mtype == REPLY and \
+			msg.body.cbody.vers == 3 and \
+			msg.body.cbody.proc == NFSPROC3_READDIRPLUS:
+
+			unpacker = NFS3Unpacker(cb_info.rpc_msg_data)
+			self.my_resop = unpacker.unpack_READDIRPLUS3res()
+
+			return 1;
+
+		return 0;
+
+	def handle(self, cb_info):
+		print "readdir is returning no pages"
+
+		msg = cb_info.rpc_msg
+
+		if msg.body.cbody.vers == 4:
+			# remove whatever results were being returned so that we have a
+			# predictable length:
+			self.my_resop.opreaddir.resok4.reply = dirlist4([], eof=0)
+
+			p = nfs4lib.FancyNFS4Packer()
+			p.pack_COMPOUND4res(cb_info.v4_res)
+			buf = p.get_buffer()
+
+			# chop off the page data:
+			cb_info.rpc_msg_data = buf[:-8]
+			#itm.dump_data(cb_info.rpc_msg_data)
+			cb_info.encode_RPC()
+			return 1
+
+		elif msg.body.cbody.vers == 3:
+			# remove whatever results were being returned so that we have a
+			# predictable length:
+			self.my_resop.resok.reply = dirlistplus3([], eof=0)
+
+			p = NFS3Packer()
+			p.pack_READDIRPLUS3res(self.my_resop)
+			buf = p.get_buffer()
+
+			# chop off the page data:
+			cb_info.rpc_msg_data = buf[:-8]
+			#itm.dump_data(cb_info.rpc_msg_data)
+			cb_info.encode_RPC()
+			return 1
+
+		return 0
-- 
1.7.1