Date: Tue, 3 Nov 2015 15:12:50 -0500 From: Larry Baird <lab@gta.com> To: freebsd-xen@freebsd.org Subject: Checksum forwarding issue on XEN Message-ID: <20151103201250.GA92469@gta.com>
next in thread | raw e-mail | index | archive | help
Has anybody made any progress on "Bug 188261 - [xen] FreeBSD DomU PVHVM guests cannot 'route' traffic for other Xen PV guests on same Dom0 Host." (https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=188261)? The code for checksum calculation in the function xnb_add_mbuf_cksum() looks suspect. switch (iph->ip_p) { case IPPROTO_TCP: if (mbufc->m_pkthdr.csum_flags & CSUM_IP_VALID) { size_t tcplen = ntohs(iph->ip_len) - sizeof(struct ip); struct tcphdr *th = (struct tcphdr*)(iph + 1); th->th_sum = in_pseudo(iph->ip_src.s_addr, iph->ip_dst.s_addr, htons(IPPROTO_TCP + tcplen)); th->th_sum = in_cksum_skip(mbufc, sizeof(struct ether_header) + ntohs(iph->ip_len), sizeof(struct ether_header) + (iph->ip_hl << 2)); } break; case IPPROTO_UDP: if (mbufc->m_pkthdr.csum_flags & CSUM_IP_VALID) { size_t udplen = ntohs(iph->ip_len) - sizeof(struct ip); struct udphdr *uh = (struct udphdr*)(iph + 1); uh->uh_sum = in_pseudo(iph->ip_src.s_addr, iph->ip_dst.s_addr, htons(IPPROTO_UDP + udplen)); uh->uh_sum = in_cksum_skip(mbufc, sizeof(struct ether_header) + ntohs(iph->ip_len), sizeof(struct ether_header) + (iph->ip_hl << 2)); } break; default: break; } Both in_pseudo() and in_cksum_skip() set the same checksum. Does this make since to anybody? Larry -- ------------------------------------------------------------------------ Larry Baird Global Technology Associates, Inc. 1992-2012 | http://www.gta.com Celebrating Twenty Years of Software Innovation | Orlando, FL Email: lab@gta.com | TEL 407-380-0220
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20151103201250.GA92469>