Return-Path: linux-nfs-owner@vger.kernel.org Received: from cn.fujitsu.com ([222.73.24.84]:17703 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1750879Ab3ANFLD convert rfc822-to-8bit (ORCPT ); Mon, 14 Jan 2013 00:11:03 -0500 Message-ID: <50F3937B.6000403@cn.fujitsu.com> Date: Mon, 14 Jan 2013 13:11:23 +0800 From: fanchaoting MIME-Version: 1.0 To: "J. Bruce Fields" CC: "linux-nfs@vger.kernel.org" Subject: Re: [PATCH] wireshark: can't decode callback if didn't caught CREATE_SESSION and SETCLIENTID packets before References: <50EFDEEA.4040201@cn.fujitsu.com> <20130112021020.GA32128@fieldses.org> In-Reply-To: <20130112021020.GA32128@fieldses.org> Content-Type: text/plain; charset=UTF-8 Sender: linux-nfs-owner@vger.kernel.org List-ID: J. Bruce Fields 写道: > On Fri, Jan 11, 2013 at 05:44:10PM +0800, fanchaoting wrote: >> now i found that nfs kernel use 0x40000000 as callback program number. >> the CREATE_SESSION and SETCLIENTID use 0x40000000 as callback program number, >> and they didn't change it. >> >> but i found that i use wireshark to decode nfsv4 callback procedures, it didn't >> decode them if the wireshark or tcpdump didn't caught CREATE_SESSION and SETCLIENTID >> packets before. > > No, this change is incorrect. > > It may be true that the current linux client always uses that program > number, but the protocol does allow the client to choose any program > number it wants, and I would not be surprised if other clients use > something different. > > There might be some other heuristic we could use to find the callbacks > in the case we didn't capture CREATE_SESSION or SETCLIENTID--maybe it > would be OK to just guess that 4 is the right number in that case--but > we must not ignore the provided cb program in the case where we do see > it. > thanks , but i think maybe it have some other ways to slove this problem. > --b. > >> Signed-off-by: Fan Chaoting >> >> --- >> epan/dissectors/packet-nfs.c | 10 ++++------ >> 1 file changed, 4 insertions(+), 6 deletions(-) >> >> diff --git a/epan/dissectors/packet-nfs.c b/epan/dissectors/packet-nfs.c >> index 63d1019..7b5ec88 100644 >> --- a/epan/dissectors/packet-nfs.c >> +++ b/epan/dissectors/packet-nfs.c >> @@ -7979,10 +7979,7 @@ dissect_nfs_cb_client4(tvbuff_t *tvb, int offset, proto_tree *tree) >> { >> proto_tree *cb_location = NULL; >> proto_item *fitem = NULL; >> - int cbprog; >> >> - cbprog = tvb_get_ntohl(tvb, offset); >> - reg_callback(cbprog); >> offset = dissect_rpc_uint32(tvb, tree, hf_nfs_cb_program, offset); >> fitem = proto_tree_add_text(tree, tvb, offset, 0, "cb_location"); >> >> @@ -8991,7 +8988,6 @@ dissect_nfs_argop4(tvbuff_t *tvb, int offset, packet_info *pinfo, >> proto_tree *ftree = NULL; >> proto_tree *newftree = NULL; >> guint32 string_length; >> - int cbprog; >> const char *name = NULL, *source_name = NULL, *dest_name=NULL; >> const char *opname=NULL; >> guint32 last_fh_hash=0; >> @@ -9012,6 +9008,10 @@ dissect_nfs_argop4(tvbuff_t *tvb, int offset, packet_info *pinfo, >> "Operations (count: %u)", ops); >> offset += 4; >> >> + /*Now the nfs use '0x40000000' as callback's program number.*/ >> +#define CB_PROG 0x40000000 >> + reg_callback(CB_PROG); >> + >> #define MAX_NFSV4_OPS 128 >> >> if (ops > MAX_NFSV4_OPS) { >> @@ -9469,8 +9469,6 @@ dissect_nfs_argop4(tvbuff_t *tvb, int offset, packet_info *pinfo, >> offset = dissect_nfs_create_session_flags(tvb, offset, newftree, hf_nfs_create_session_flags_csa); >> offset = dissect_rpc_chanattrs4(tvb, offset, newftree, "csa_fore_chan_attrs"); >> offset = dissect_rpc_chanattrs4(tvb, offset, newftree, "csa_back_chan_attrs"); >> - cbprog = tvb_get_ntohl(tvb, offset); >> - reg_callback(cbprog); >> offset = dissect_rpc_uint32(tvb, newftree, hf_nfs_cb_program, offset); >> offset = dissect_rpc_secparms4(tvb, offset, newftree); >> break; >> -- >> 1.7.10.1 > > > >