From mboxrd@z Thu Jan 1 00:00:00 1970 From: Petr Vorel Date: Thu, 2 May 2019 13:44:59 +0200 Subject: [LTP] [PATCH 1/1] net/broken_ip: Rewrite into new API In-Reply-To: <5cff91e0-c566-27c3-95dd-39dd4e2b6d0e@oracle.com> References: <20190427053929.7372-1-pvorel@suse.cz> <5cff91e0-c566-27c3-95dd-39dd4e2b6d0e@oracle.com> Message-ID: <20190502114459.GA32460@dell5510> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ltp@lists.linux.it Hi Alexey, > Acked-by: Alexey Kodanev ... > > +export ICMPV4_DATA_MAXSIZE=1472 > > +export ICMPV6_DATA_MAXSIZE=1452 > Since these variables are in the library, may be it would be better to tune > them depending on an MTU of the tests interfaces? Good idea. 1472 and 1452 are based on MTU = 1500 (IPv4: 1500 - 20 bytes for IPv4 header - 8 bytes for ICMP header; IPv6: 1500 - 40 bytes for IPv6 header - 8 bytes for ICMP header), which looks to me as the default for netns NICs and ethernet and wifi NICs, but we should avoid failures when different MTU used. I propose merging this version and add MTU detection support later. I guess we don't need to check -s values passed to tst_icmp() (I guess nobody set MTU < 1000, although it's not forbidden for IPv4). But I'd add this check also into ns-icmpv[46]_sender.c. + off course other cleanup like merging ns-icmpv[46]_sender.c into single code would be nice, but first I want to finish route rewriting. > Also we can send more with fragmentation, but I guess ns-icmpv doesn't > have proper support... Do you mean to send packet big enough to have fragmentation on lhost? + setsockopt IP_PMTUDISC_DONT? Kind regards, Petr