Hi Dejan, Thanks for your quick reply.
Sorry, I never tried with a mask of 128. Regards, Pascal > -----Original Message----- > From: linux-ha-dev-boun...@lists.linux-ha.org > [mailto:linux-ha-dev-boun...@lists.linux-ha.org] On Behalf Of > Dejan Muhamedagic > Sent: Friday, June 05, 2009 1:09 PM > To: High-Availability Linux Development List > Subject: Re: [Linux-ha-dev] Checksum not computed in ICMPv6 > neighbor advertisement > > Hi Andre, > > On Fri, Jun 05, 2009 at 09:34:37AM +0000, Andre, Pascal wrote: > > Hi, > > > > On an Active/Standby platform (using Linux-HA 2.1.4 RHEL5, in my > > case), when a fail-over/switch-over is initiated and > standby machine > > takes over the virtual IP (IPv6), IPv6addr broadcasts an ICMPv6 > > neighbor advertisement message. > > > > Unfortunately, this ICMPv6 message has its checksum field set to 0 > > (i.e. not computed). The message is thus discarded by recipients. > > > > Maybe this computation should be done by libnet itself. > > Unfortunately, without much time to investigate libnet, I've added > > code in resources/OCF/IPv6addr.c in order to compute the > checksum and > > provide the result to libnet (as a parameter). > > Applied. Many thanks for the patch. > > BTW, a user recently complained on the user mailing list > about not being able to run IPv6addr with mask 128. Did you > ever experience that? I looked at the code a bit, couldn't > find a problem. Oh, and it only prints the Generic error > (exit code 1) and one couldn't figure out anything from the strace. > > Cheers, > > Dejan > > > Regards, > > Pascal ANDRE > > > > > > --- IPv6addr.c.old 2009-04-30 10:15:16.000000000 +0200 > > +++ IPv6addr.c 2009-04-30 11:45:43.000000000 +0200 > > @@ -381,6 +381,58 @@ > > return OCF_NOT_RUNNING; > > } > > > > +/* compute ICMPv6 checksum */ > > +static uint32_t > > +cksum_sum(uint16_t *addr, int len, int ntoh) { > > + uint16_t * w = addr; > > + uint16_t ret = 0; > > + uint32_t sum = 0; > > + > > + while (len > 1) { > > + ret = *w++; > > + if (ntoh) ret = ntohs(ret); > > + sum += ret; > > + len -= 2; > > + } > > + > > + if (len == 1) { > > + *(unsigned char *) (&ret) = *(unsigned char *) w; sum += ret; } > > + > > + return sum; > > +} > > + > > +static uint16_t > > +icmpv6_cksum(struct in6_addr* src_ip, struct > libnet_in6_addr* dst_ip, > > +char* payload, int payload_len) { uint32_t sum = 0; > uint16_t val = > > +0; > > + > > + /* IPv6 pseudo header */ > > + sum += cksum_sum( src_ip->s6_addr16, 16, 1 ); sum += cksum_sum( > > + (uint16_t *)dst_ip, 16, 1 ); val = payload_len + (2 * > > + sizeof(uint32_t)); sum += cksum_sum( &val, 2, 0 ); val = > 58; sum += > > + cksum_sum( &val, 2, 0 ); > > + > > + /* ICMPv6 packet */ > > + val = 0x8800; > > + sum += cksum_sum( &val, 2, 0 ); > > + val = 0x2000; > > + sum += cksum_sum( &val, 2, 0 ); > > + sum += cksum_sum( (uint16_t *)payload, payload_len, 1 ); > > + > > + /* perform 16-bit one's complement of sum */ sum = (sum >> 16) + > > + (sum & 0xffff); sum += (sum >> 16); val = ~sum; > > + > > + return val; > > +} > > + > > /* Send an unsolicited advertisement packet > > * Please refer to rfc2461 > > */ > > @@ -416,7 +468,7 @@ > > > > libnet_seed_prand(l); > > /* 0x2000: RSO */ > > - libnet_build_icmpv4_echo(136,0,0,0x2000,0,(u_int8_t *)payload > > + > libnet_build_icmpv4_echo(136,0,icmpv6_cksum(src_ip,&dst_ip,payload,s > > + izeof(payload)),0x2000,0,(u_int8_t *)payload > > ,sizeof(payload), l, LIBNET_PTAG_INITIALIZER); > > libnet_build_ipv6(0,0,LIBNET_ICMPV6_H + > sizeof(payload),IPPROTO_ICMP6, > > 255,*(struct libnet_in6_addr*)src_ip, > > > _______________________________________________________ > > Linux-HA-Dev: Linux-HA-Dev@lists.linux-ha.org > > http://lists.linux-ha.org/mailman/listinfo/linux-ha-dev > > Home Page: http://linux-ha.org/ > > _______________________________________________________ > Linux-HA-Dev: Linux-HA-Dev@lists.linux-ha.org > http://lists.linux-ha.org/mailman/listinfo/linux-ha-dev > Home Page: http://linux-ha.org/ > _______________________________________________________ Linux-HA-Dev: Linux-HA-Dev@lists.linux-ha.org http://lists.linux-ha.org/mailman/listinfo/linux-ha-dev Home Page: http://linux-ha.org/
