29.01.2019, 01:18, "Paul Moore" <paul@xxxxxxxxxxxxxx>: > If we don't pass a skb into ip_options_compile(), meaning both "skb" > and "rt" will be NULL, then I don't believe the option data will > change. Am I missing something? > > -- > paul moore > www.paul-moore.com I mean, in cipso_v4_error we copy option data from skb before ip_options_compile call: + memcpy(opt->__data, (unsigned char *)&(ip_hdr(skb)[1]), opt->optlen); But skb IP header data could be already changed by first call of ip_options_compile when packet received.