> -----Original Message----- > From: Wong, Matthew [mailto:mw...@sonusnet.com] > Sent: Wednesday, February 22, 2017 03:19 PM > To: tipc-discussion@lists.sourceforge.net > Subject: Re: [tipc-discussion] tipc multicast stuck (hit max window) due to > invalid bc_ack value > > Hi Jon, > > Thanks for the comment, I totally agreed that skb_may_pull is the one > changing the data content, but that procedure trace is a bit Hard to follow. > So > the correct data is probably after validate has linearized the data. It seems > safe to make the change anyway since no one uses bc_ack before validate. > > We are checking that if we have your recommended patch. Is that patch > already in kernel 4.9.11?
Yes, it is. ///jon > > Thanks, > Matthew > > > -----Original Message----- > From: Jon Maloy [mailto:jon.ma...@ericsson.com] > Sent: Wednesday, February 22, 2017 2:57 PM > To: Wong, Matthew; tipc-discussion@lists.sourceforge.net > Subject: RE: [tipc-discussion] tipc multicast stuck (hit max window) due to > invalid bc_ack value > > Hi Matthew, > See below for my comment. > > Also, although this is about a different problem, you should check if you have > the following patch, and the one it is referring to: > commit 06bd2b1ed04ca9f (" tipc: fix broadcast link synchronization problem") > > > > -----Original Message----- > > From: Wong, Matthew [mailto:mw...@sonusnet.com] > > Sent: Wednesday, February 22, 2017 12:41 PM > > To: tipc-discussion@lists.sourceforge.net > > Subject: [tipc-discussion] tipc multicast stuck (hit max window) due > > to invalid bc_ack value > > > > > > Hi all, > > > > I'm currently working on 4.4.0 kernel and is observing the > > following issues on tipc multicast. > > > > > > 1. I have a system setup with 3 CPUs each using tipc to multicast to > > processes running on each CPU. After sending around 50 messages (the > > max window size), the far end did not receive the message any more. > > When Iooking at the tipc-conf -ls data, it said the broadcast-link > > start bunding > > [...] > > > > > 4. It seems the tipc_msg_validate modified the skb message and the > hdr. > > The modified data looks fine and has the correct expected bc-ack/ack > > values in the message. However, currently the bc_ack and ack value is > > initialized before the tipc_msg_validate and so we'll use that value > > which may cause issue on my bc_ack update and comparsion. > > The only possible culprit here is the function skb_may_pull(), which is called > from msg_validate() in the rare case that header part of the packet buffer is > non-linear. The function is a little hard to follow, but as I understand it, > it > linearizes the buffer in such cases, and header fields read before the > validation will obviously be wrong. > > > > > > > > > 5 If i move the bc_ack and ack after tipc_msg_validate, i don't have > > any > > more tipc multicast stuck issue. I have run it for half a day with > > multicast on 4 CPUs and so far there is no tipc multicast bundle > > trigger and no bogus bc_ack issue. All multicast messges has been sent and > received properly. > > > > > > > > 6 Is this a known behavior and is this an issue? If yes, is this a > > patch for it > > and will 4.4.48 has the same issue? Does the tipc_msg_validate > > function suppose to modify the hdr data and should we use the > > bc_ack/ack values afterwards the modification is completed. > > We have never seen this before, but your diagnostics is totally credible. I > will > post a patch for this asap. > Nice job! > > BR > ///jon > > > > > > > > > Any comment is appreciated. > > > > > > > > Regards, > > > > Matthew > > > > Sonus network. > > > > ---------------------------------------------------------------------- > > -------- Check out the vibrant tech community on one of the world's > > most engaging tech sites, SlashDot.org! http://sdm.link/slashdot > > _______________________________________________ > > tipc-discussion mailing list > > tipc-discussion@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/tipc-discussion > > > ------------------------------------------------------------------------------ > Check out the vibrant tech community on one of the world's most engaging > tech sites, SlashDot.org! http://sdm.link/slashdot > _______________________________________________ > tipc-discussion mailing list > tipc-discussion@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/tipc-discussion ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ tipc-discussion mailing list tipc-discussion@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/tipc-discussion
