On 2016年07月11日 18:02, Zhang Chen wrote:
+static int colo_packet_compare_icmp(Packet *spkt, Packet *ppkt)
+{
+ int network_length;
+ struct icmp *icmp_ppkt, *icmp_spkt;
+
+ trace_colo_compare_main("compare icmp");
+ network_length = ppkt->ip->ip_hl * 4;
+ if (ppkt->size != spkt->size ||
+ ppkt->size < network_length + ETH_HLEN) {
+ trace_colo_compare_icmp_miscompare_size(ppkt->size, spkt->size);
+ return -1;
+ }
+ icmp_ppkt = (struct icmp *)(ppkt->data + network_length +
ETH_HLEN);
+ icmp_spkt = (struct icmp *)(spkt->data + network_length +
ETH_HLEN);
+
+ if ((icmp_ppkt->icmp_type == icmp_spkt->icmp_type) &&
+ (icmp_ppkt->icmp_code == icmp_spkt->icmp_code)) {
+ if (icmp_ppkt->icmp_type == ICMP_REDIRECT) {
+ if (icmp_ppkt->icmp_gwaddr.s_addr !=
+ icmp_spkt->icmp_gwaddr.s_addr) {
+ trace_colo_compare_main("icmp_gwaddr.s_addr not
same");
+ trace_colo_compare_icmp_miscompare_addr("ppkt s_addr",
+ inet_ntoa(icmp_ppkt->icmp_gwaddr));
+ trace_colo_compare_icmp_miscompare_addr("spkt s_addr",
+ inet_ntoa(icmp_spkt->icmp_gwaddr));
+ return -1;
+ }
+ } else if ((icmp_ppkt->icmp_type == ICMP_UNREACH) &&
+ (icmp_ppkt->icmp_type == ICMP_UNREACH_NEEDFRAG)) {
+ if (icmp_ppkt->icmp_nextmtu != icmp_spkt->icmp_nextmtu) {
+ trace_colo_compare_main("icmp_nextmtu not same");
+ trace_colo_compare_icmp_miscompare_mtu("ppkt nextmtu",
+ icmp_ppkt->icmp_nextmtu);
+ trace_colo_compare_icmp_miscompare_mtu("spkt nextmtu",
+ icmp_spkt->icmp_nextmtu);
+ return -1;
+ }
+ }
+ } else {
+ return -1;
+ }
Why only compare part of icmp packet?
That's include most of situation, increase all part of icmp
can reduce compare efficiency.
Thanks
Zhang Chen
I believe we should cover all instead of "most" of situations. And looks
like icmp packet were all small, so there's probably no need to do
special tricks like this.
