Sorry, but yersteday I thought that my first mail adress does not work well, cause I did not get an answer and I wrote the same message with a new mail adress. I'm newbie in mailing list, sorry again!
My problem append when I use the pbuf_cat function, and I use this only if there is a communication problem. When I look for the execution code in debug mode, when my problem append, so LWIP go in pbuf_cat function and after inet_chksum calculate checksum with p->len but the message which is sent is p->tot_len long! And wireshark says TCP CHECKSUM INCORRECT and He's right! When you go in pbuf_cat function, after the TCP Checksum is OK? > -----Message d'origine----- > De : [email protected] > [mailto:[email protected]] De la > part de Simon Goldschmidt > Envoyé : mardi 17 novembre 2009 10:11 > À : Mailing list for lwIP users > Objet : Re: RE: [lwip-users] Checksum Incorrect caused by Concatenation > > > Just sending a post a second time is normally not a way to attract much > attention... > > > "Hervé GARAT : Audemat" wrote: > > > > Kieran said: > > >No, that's wrong. p->len refers to the length of each individual pbuf. > > >We've added another pbuf to the chain, but not changed the length of > > >each pbuf. Because the chain is longer, we increment the length of > > >p->tot_len, but not the length of p->len. > > > > But in the inet_chksum_pseudo function,the len used to make checksum is > > p->len and not p->tot_len. However the message sent is long as p- > >tot_len, > > therefore the TCP checksum is Incorrect!! > > > > All the other change that I made(queuelen-- > > ;pbuf_free(p->queuelen);...)are made to have a valid checksum if LWIP do > a concatenation. > > As Kieran also said, the pbuf_free() is *wrong*, too. > > > > > What's the best way to solve my problem? > > To be able to tell you that I would have to get your problem first. In my > software, the same code path is executed and there is no error. > > Simon > -- > DSL-Preisknaller: DSL Komplettpakete von GMX schon für > 16,99 Euro mtl.!* Hier klicken: http://portal.gmx.net/de/go/dsl02 > > > _______________________________________________ > lwip-users mailing list > [email protected] > http://lists.nongnu.org/mailman/listinfo/lwip-users _______________________________________________ lwip-users mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/lwip-users
