// See the file "COPYING" in the main distribution directory for copyright.

#include "IP.h"

#include <sys/types.h>
#include <netinet/in.h>
#include <netinet/icmp6.h>

#include "IPAddr.h"
#include "Type.h"
#include "Val.h"
#include "Var.h"
#include "ZeekString.h"
#include "Reporter.h"

static zeek::VectorValPtr BuildOptionsVal(const u_char* data, int len)
	{
	auto vv = zeek::make_intrusive<zeek::VectorVal>(zeek::id::find_type<zeek::VectorType>("ip6_options"));

	while ( len > 0 )
		{
		static auto ip6_option_type = zeek::id::find_type<zeek::RecordType>("ip6_option");
		const struct ip6_opt* opt = (const struct ip6_opt*) data;
		auto rv = zeek::make_intrusive<zeek::RecordVal>(ip6_option_type);
		rv->Assign(0, zeek::val_mgr->Count(opt->ip6o_type));

		if ( opt->ip6o_type == 0 )
			{
			// Pad1 option
			rv->Assign(1, zeek::val_mgr->Count(0));
			rv->Assign(2, zeek::val_mgr->EmptyString());
			data += sizeof(uint8_t);
			len -= sizeof(uint8_t);
			}
		else
			{
			// PadN or other option
			uint16_t off = 2 * sizeof(uint8_t);
			rv->Assign(1, zeek::val_mgr->Count(opt->ip6o_len));
			rv->Assign(2, zeek::make_intrusive<zeek::StringVal>(
			        new zeek::String(data + off, opt->ip6o_len, true)));
			data += opt->ip6o_len + off;
			len -= opt->ip6o_len + off;
			}

		vv->Assign(vv->Size(), std::move(rv));
		}

	return vv;
	}

namespace zeek {

zeek::RecordValPtr IPv6_Hdr::ToVal(zeek::VectorValPtr chain) const
	{
	zeek::RecordValPtr rv;

	switch ( type ) {
	case IPPROTO_IPV6:
		{
		static auto ip6_hdr_type = zeek::id::find_type<zeek::RecordType>("ip6_hdr");
		rv = zeek::make_intrusive<zeek::RecordVal>(ip6_hdr_type);
		const struct ip6_hdr* ip6 = (const struct ip6_hdr*)data;
		rv->Assign(0, zeek::val_mgr->Count((ntohl(ip6->ip6_flow) & 0x0ff00000)>>20));
		rv->Assign(1, zeek::val_mgr->Count(ntohl(ip6->ip6_flow) & 0x000fffff));
		rv->Assign(2, zeek::val_mgr->Count(ntohs(ip6->ip6_plen)));
		rv->Assign(3, zeek::val_mgr->Count(ip6->ip6_nxt));
		rv->Assign(4, zeek::val_mgr->Count(ip6->ip6_hlim));
		rv->Assign(5, zeek::make_intrusive<zeek::AddrVal>(IPAddr(ip6->ip6_src)));
		rv->Assign(6, zeek::make_intrusive<zeek::AddrVal>(IPAddr(ip6->ip6_dst)));
		if ( ! chain )
			chain = zeek::make_intrusive<zeek::VectorVal>(
			    zeek::id::find_type<zeek::VectorType>("ip6_ext_hdr_chain"));
		rv->Assign(7, std::move(chain));
		}
		break;

	case IPPROTO_HOPOPTS:
		{
		static auto ip6_hopopts_type = zeek::id::find_type<zeek::RecordType>("ip6_hopopts");
		rv = zeek::make_intrusive<zeek::RecordVal>(ip6_hopopts_type);
		const struct ip6_hbh* hbh = (const struct ip6_hbh*)data;
		rv->Assign(0, zeek::val_mgr->Count(hbh->ip6h_nxt));
		rv->Assign(1, zeek::val_mgr->Count(hbh->ip6h_len));
		uint16_t off = 2 * sizeof(uint8_t);
		rv->Assign(2, BuildOptionsVal(data + off, Length() - off));

		}
		break;

	case IPPROTO_DSTOPTS:
		{
		static auto ip6_dstopts_type = zeek::id::find_type<zeek::RecordType>("ip6_dstopts");
		rv = zeek::make_intrusive<zeek::RecordVal>(ip6_dstopts_type);
		const struct ip6_dest* dst = (const struct ip6_dest*)data;
		rv->Assign(0, zeek::val_mgr->Count(dst->ip6d_nxt));
		rv->Assign(1, zeek::val_mgr->Count(dst->ip6d_len));
		uint16_t off = 2 * sizeof(uint8_t);
		rv->Assign(2, BuildOptionsVal(data + off, Length() - off));
		}
		break;

	case IPPROTO_ROUTING:
		{
		static auto ip6_routing_type = zeek::id::find_type<zeek::RecordType>("ip6_routing");
		rv = zeek::make_intrusive<zeek::RecordVal>(ip6_routing_type);
		const struct ip6_rthdr* rt = (const struct ip6_rthdr*)data;
		rv->Assign(0, zeek::val_mgr->Count(rt->ip6r_nxt));
		rv->Assign(1, zeek::val_mgr->Count(rt->ip6r_len));
		rv->Assign(2, zeek::val_mgr->Count(rt->ip6r_type));
		rv->Assign(3, zeek::val_mgr->Count(rt->ip6r_segleft));
		uint16_t off = 4 * sizeof(uint8_t);
		rv->Assign(4, zeek::make_intrusive<zeek::StringVal>(new zeek::String(data + off, Length() - off, true)));
		}
		break;

	case IPPROTO_FRAGMENT:
		{
		static auto ip6_fragment_type = zeek::id::find_type<zeek::RecordType>("ip6_fragment");
		rv = zeek::make_intrusive<zeek::RecordVal>(ip6_fragment_type);
		const struct ip6_frag* frag = (const struct ip6_frag*)data;
		rv->Assign(0, zeek::val_mgr->Count(frag->ip6f_nxt));
		rv->Assign(1, zeek::val_mgr->Count(frag->ip6f_reserved));
		rv->Assign(2, zeek::val_mgr->Count((ntohs(frag->ip6f_offlg) & 0xfff8)>>3));
		rv->Assign(3, zeek::val_mgr->Count((ntohs(frag->ip6f_offlg) & 0x0006)>>1));
		rv->Assign(4, zeek::val_mgr->Bool(ntohs(frag->ip6f_offlg) & 0x0001));
		rv->Assign(5, zeek::val_mgr->Count(ntohl(frag->ip6f_ident)));
		}
		break;

	case IPPROTO_AH:
		{
		static auto ip6_ah_type = zeek::id::find_type<zeek::RecordType>("ip6_ah");
		rv = zeek::make_intrusive<zeek::RecordVal>(ip6_ah_type);
		rv->Assign(0, zeek::val_mgr->Count(((ip6_ext*)data)->ip6e_nxt));
		rv->Assign(1, zeek::val_mgr->Count(((ip6_ext*)data)->ip6e_len));
		rv->Assign(2, zeek::val_mgr->Count(ntohs(((uint16_t*)data)[1])));
		rv->Assign(3, zeek::val_mgr->Count(ntohl(((uint32_t*)data)[1])));

		if ( Length() >= 12 )
			{
			// Sequence Number and ICV fields can only be extracted if
			// Payload Len was non-zero for this header.
			rv->Assign(4, zeek::val_mgr->Count(ntohl(((uint32_t*)data)[2])));
			uint16_t off = 3 * sizeof(uint32_t);
			rv->Assign(5, zeek::make_intrusive<zeek::StringVal>(new zeek::String(data + off, Length() - off, true)));
			}
		}
		break;

	case IPPROTO_ESP:
		{
		static auto ip6_esp_type = zeek::id::find_type<zeek::RecordType>("ip6_esp");
		rv = zeek::make_intrusive<zeek::RecordVal>(ip6_esp_type);
		const uint32_t* esp = (const uint32_t*)data;
		rv->Assign(0, zeek::val_mgr->Count(ntohl(esp[0])));
		rv->Assign(1, zeek::val_mgr->Count(ntohl(esp[1])));
		}
		break;

#ifdef ENABLE_MOBILE_IPV6
	case IPPROTO_MOBILITY:
		{
		static auto ip6_mob_type = zeek::id::find_type<zeek::RecordType>("ip6_mobility_hdr");
		rv = zeek::make_intrusive<zeek::RecordVal>(ip6_mob_type);
		const struct ip6_mobility* mob = (const struct ip6_mobility*) data;
		rv->Assign(0, zeek::val_mgr->Count(mob->ip6mob_payload));
		rv->Assign(1, zeek::val_mgr->Count(mob->ip6mob_len));
		rv->Assign(2, zeek::val_mgr->Count(mob->ip6mob_type));
		rv->Assign(3, zeek::val_mgr->Count(mob->ip6mob_rsv));
		rv->Assign(4, zeek::val_mgr->Count(ntohs(mob->ip6mob_chksum)));

		static auto ip6_mob_msg_type = zeek::id::find_type<zeek::RecordType>("ip6_mobility_msg");
		auto msg = zeek::make_intrusive<zeek::RecordVal>(ip6_mob_msg_type);
		msg->Assign(0, zeek::val_mgr->Count(mob->ip6mob_type));

		uint16_t off = sizeof(ip6_mobility);
		const u_char* msg_data = data + off;

		static auto ip6_mob_brr_type = zeek::id::find_type<zeek::RecordType>("ip6_mobility_brr");
		static auto ip6_mob_hoti_type = zeek::id::find_type<zeek::RecordType>("ip6_mobility_hoti");
		static auto ip6_mob_coti_type = zeek::id::find_type<zeek::RecordType>("ip6_mobility_coti");
		static auto ip6_mob_hot_type = zeek::id::find_type<zeek::RecordType>("ip6_mobility_hot");
		static auto ip6_mob_cot_type = zeek::id::find_type<zeek::RecordType>("ip6_mobility_cot");
		static auto ip6_mob_bu_type = zeek::id::find_type<zeek::RecordType>("ip6_mobility_bu");
		static auto ip6_mob_back_type = zeek::id::find_type<zeek::RecordType>("ip6_mobility_back");
		static auto ip6_mob_be_type = zeek::id::find_type<zeek::RecordType>("ip6_mobility_be");

		switch ( mob->ip6mob_type ) {
		case 0:
			{
			auto m = zeek::make_intrusive<zeek::RecordVal>(ip6_mob_brr_type);
			m->Assign(0, zeek::val_mgr->Count(ntohs(*((uint16_t*)msg_data))));
			off += sizeof(uint16_t);
			m->Assign(1, BuildOptionsVal(data + off, Length() - off));
			msg->Assign(1, std::move(m));
			}
			break;

		case 1:
			{
			auto m = zeek::make_intrusive<zeek::RecordVal>(ip6_mob_hoti_type);
			m->Assign(0, zeek::val_mgr->Count(ntohs(*((uint16_t*)msg_data))));
			m->Assign(1, zeek::val_mgr->Count(ntohll(*((uint64_t*)(msg_data + sizeof(uint16_t))))));
			off += sizeof(uint16_t) + sizeof(uint64_t);
			m->Assign(2, BuildOptionsVal(data + off, Length() - off));
			msg->Assign(2, std::move(m));
			break;
			}

		case 2:
			{
			auto m = zeek::make_intrusive<zeek::RecordVal>(ip6_mob_coti_type);
			m->Assign(0, zeek::val_mgr->Count(ntohs(*((uint16_t*)msg_data))));
			m->Assign(1, zeek::val_mgr->Count(ntohll(*((uint64_t*)(msg_data + sizeof(uint16_t))))));
			off += sizeof(uint16_t) + sizeof(uint64_t);
			m->Assign(2, BuildOptionsVal(data + off, Length() - off));
			msg->Assign(3, std::move(m));
			break;
			}

		case 3:
			{
			auto m = zeek::make_intrusive<zeek::RecordVal>(ip6_mob_hot_type);
			m->Assign(0, zeek::val_mgr->Count(ntohs(*((uint16_t*)msg_data))));
			m->Assign(1, zeek::val_mgr->Count(ntohll(*((uint64_t*)(msg_data + sizeof(uint16_t))))));
			m->Assign(2, zeek::val_mgr->Count(ntohll(*((uint64_t*)(msg_data + sizeof(uint16_t) + sizeof(uint64_t))))));
			off += sizeof(uint16_t) + 2 * sizeof(uint64_t);
			m->Assign(3, BuildOptionsVal(data + off, Length() - off));
			msg->Assign(4, std::move(m));
			break;
			}

		case 4:
			{
			auto m = zeek::make_intrusive<zeek::RecordVal>(ip6_mob_cot_type);
			m->Assign(0, zeek::val_mgr->Count(ntohs(*((uint16_t*)msg_data))));
			m->Assign(1, zeek::val_mgr->Count(ntohll(*((uint64_t*)(msg_data + sizeof(uint16_t))))));
			m->Assign(2, zeek::val_mgr->Count(ntohll(*((uint64_t*)(msg_data + sizeof(uint16_t) + sizeof(uint64_t))))));
			off += sizeof(uint16_t) + 2 * sizeof(uint64_t);
			m->Assign(3, BuildOptionsVal(data + off, Length() - off));
			msg->Assign(5, std::move(m));
			break;
			}

		case 5:
			{
			auto m = zeek::make_intrusive<zeek::RecordVal>(ip6_mob_bu_type);
			m->Assign(0, zeek::val_mgr->Count(ntohs(*((uint16_t*)msg_data))));
			m->Assign(1, zeek::val_mgr->Bool(ntohs(*((uint16_t*)(msg_data + sizeof(uint16_t)))) & 0x8000));
			m->Assign(2, zeek::val_mgr->Bool(ntohs(*((uint16_t*)(msg_data + sizeof(uint16_t)))) & 0x4000));
			m->Assign(3, zeek::val_mgr->Bool(ntohs(*((uint16_t*)(msg_data + sizeof(uint16_t)))) & 0x2000));
			m->Assign(4, zeek::val_mgr->Bool(ntohs(*((uint16_t*)(msg_data + sizeof(uint16_t)))) & 0x1000));
			m->Assign(5, zeek::val_mgr->Count(ntohs(*((uint16_t*)(msg_data + 2*sizeof(uint16_t))))));
			off += 3 * sizeof(uint16_t);
			m->Assign(6, BuildOptionsVal(data + off, Length() - off));
			msg->Assign(6, std::move(m));
			break;
			}

		case 6:
			{
			auto m = zeek::make_intrusive<zeek::RecordVal>(ip6_mob_back_type);
			m->Assign(0, zeek::val_mgr->Count(*((uint8_t*)msg_data)));
			m->Assign(1, zeek::val_mgr->Bool(*((uint8_t*)(msg_data + sizeof(uint8_t))) & 0x80));
			m->Assign(2, zeek::val_mgr->Count(ntohs(*((uint16_t*)(msg_data + sizeof(uint16_t))))));
			m->Assign(3, zeek::val_mgr->Count(ntohs(*((uint16_t*)(msg_data + 2*sizeof(uint16_t))))));
			off += 3 * sizeof(uint16_t);
			m->Assign(4, BuildOptionsVal(data + off, Length() - off));
			msg->Assign(7, std::move(m));
			break;
			}

		case 7:
			{
			auto m = zeek::make_intrusive<zeek::RecordVal>(ip6_mob_be_type);
			m->Assign(0, zeek::val_mgr->Count(*((uint8_t*)msg_data)));
			const in6_addr* hoa = (const in6_addr*)(msg_data + sizeof(uint16_t));
			m->Assign(1, zeek::make_intrusive<zeek::AddrVal>(IPAddr(*hoa)));
			off += sizeof(uint16_t) + sizeof(in6_addr);
			m->Assign(2, BuildOptionsVal(data + off, Length() - off));
			msg->Assign(8, std::move(m));
			break;
			}

		default:
			zeek::reporter->Weird("unknown_mobility_type", fmt("%d", mob->ip6mob_type));
			break;
		}

		rv->Assign(5, std::move(msg));
		}
		break;
#endif //ENABLE_MOBILE_IPV6

	default:
		break;
	}

	return rv;
	}

zeek::RecordValPtr IPv6_Hdr::ToVal() const
	{ return ToVal(nullptr); }

zeek::RecordVal* IPv6_Hdr::BuildRecordVal(zeek::VectorVal* chain) const
	{
	return ToVal({zeek::AdoptRef{}, chain}).release();
	}

IPAddr IP_Hdr::IPHeaderSrcAddr() const
	{
	return ip4 ? IPAddr(ip4->ip_src) : IPAddr(ip6->ip6_src);
	}

IPAddr IP_Hdr::IPHeaderDstAddr() const
	{
	return ip4 ? IPAddr(ip4->ip_dst) : IPAddr(ip6->ip6_dst);
	}

IPAddr IP_Hdr::SrcAddr() const
	{
	return ip4 ? IPAddr(ip4->ip_src) : ip6_hdrs->SrcAddr();
	}

IPAddr IP_Hdr::DstAddr() const
	{
	return ip4 ? IPAddr(ip4->ip_dst) : ip6_hdrs->DstAddr();
	}

zeek::RecordValPtr IP_Hdr::ToIPHdrVal() const
	{
	zeek::RecordValPtr rval;

	if ( ip4 )
		{
		static auto ip4_hdr_type = zeek::id::find_type<zeek::RecordType>("ip4_hdr");
		rval = zeek::make_intrusive<zeek::RecordVal>(ip4_hdr_type);
		rval->Assign(0, zeek::val_mgr->Count(ip4->ip_hl * 4));
		rval->Assign(1, zeek::val_mgr->Count(ip4->ip_tos));
		rval->Assign(2, zeek::val_mgr->Count(ntohs(ip4->ip_len)));
		rval->Assign(3, zeek::val_mgr->Count(ntohs(ip4->ip_id)));
		rval->Assign(4, zeek::val_mgr->Count(ip4->ip_ttl));
		rval->Assign(5, zeek::val_mgr->Count(ip4->ip_p));
		rval->Assign(6, zeek::make_intrusive<zeek::AddrVal>(ip4->ip_src.s_addr));
		rval->Assign(7, zeek::make_intrusive<zeek::AddrVal>(ip4->ip_dst.s_addr));
		}
	else
		{
		rval = ((*ip6_hdrs)[0])->ToVal(ip6_hdrs->ToVal());
		}

	return rval;
	}

zeek::RecordVal* IP_Hdr::BuildIPHdrVal() const
	{
	return ToIPHdrVal().release();
	}

zeek::RecordValPtr IP_Hdr::ToPktHdrVal() const
	{
	static auto pkt_hdr_type = zeek::id::find_type<zeek::RecordType>("pkt_hdr");
	return ToPktHdrVal(zeek::make_intrusive<zeek::RecordVal>(pkt_hdr_type), 0);
	}

zeek::RecordVal* IP_Hdr::BuildPktHdrVal() const
	{
	return ToPktHdrVal().release();
	}

zeek::RecordValPtr IP_Hdr::ToPktHdrVal(zeek::RecordValPtr pkt_hdr, int sindex) const
	{
	static auto tcp_hdr_type = zeek::id::find_type<zeek::RecordType>("tcp_hdr");
	static auto udp_hdr_type = zeek::id::find_type<zeek::RecordType>("udp_hdr");
	static auto icmp_hdr_type = zeek::id::find_type<zeek::RecordType>("icmp_hdr");

	if ( ip4 )
		pkt_hdr->Assign(sindex + 0, ToIPHdrVal());
	else
		pkt_hdr->Assign(sindex + 1, ToIPHdrVal());

	// L4 header.
	const u_char* data = Payload();

	int proto = NextProto();
	switch ( proto ) {
	case IPPROTO_TCP:
		{
		const struct tcphdr* tp = (const struct tcphdr*) data;
		auto tcp_hdr = zeek::make_intrusive<zeek::RecordVal>(tcp_hdr_type);

		int tcp_hdr_len = tp->th_off * 4;
		int data_len = PayloadLen() - tcp_hdr_len;

		tcp_hdr->Assign(0, zeek::val_mgr->Port(ntohs(tp->th_sport), TRANSPORT_TCP));
		tcp_hdr->Assign(1, zeek::val_mgr->Port(ntohs(tp->th_dport), TRANSPORT_TCP));
		tcp_hdr->Assign(2, zeek::val_mgr->Count(uint32_t(ntohl(tp->th_seq))));
		tcp_hdr->Assign(3, zeek::val_mgr->Count(uint32_t(ntohl(tp->th_ack))));
		tcp_hdr->Assign(4, zeek::val_mgr->Count(tcp_hdr_len));
		tcp_hdr->Assign(5, zeek::val_mgr->Count(data_len));
		tcp_hdr->Assign(6, zeek::val_mgr->Count(tp->th_x2));
		tcp_hdr->Assign(7, zeek::val_mgr->Count(tp->th_flags));
		tcp_hdr->Assign(8, zeek::val_mgr->Count(ntohs(tp->th_win)));

		pkt_hdr->Assign(sindex + 2, std::move(tcp_hdr));
		break;
		}

	case IPPROTO_UDP:
		{
		const struct udphdr* up = (const struct udphdr*) data;
		auto udp_hdr = zeek::make_intrusive<zeek::RecordVal>(udp_hdr_type);

		udp_hdr->Assign(0, zeek::val_mgr->Port(ntohs(up->uh_sport), TRANSPORT_UDP));
		udp_hdr->Assign(1, zeek::val_mgr->Port(ntohs(up->uh_dport), TRANSPORT_UDP));
		udp_hdr->Assign(2, zeek::val_mgr->Count(ntohs(up->uh_ulen)));

		pkt_hdr->Assign(sindex + 3, std::move(udp_hdr));
		break;
		}

	case IPPROTO_ICMP:
		{
		const struct icmp* icmpp = (const struct icmp *) data;
		auto icmp_hdr = zeek::make_intrusive<zeek::RecordVal>(icmp_hdr_type);

		icmp_hdr->Assign(0, zeek::val_mgr->Count(icmpp->icmp_type));

		pkt_hdr->Assign(sindex + 4, std::move(icmp_hdr));
		break;
		}

	case IPPROTO_ICMPV6:
		{
		const struct icmp6_hdr* icmpp = (const struct icmp6_hdr*) data;
		auto icmp_hdr = zeek::make_intrusive<zeek::RecordVal>(icmp_hdr_type);

		icmp_hdr->Assign(0, zeek::val_mgr->Count(icmpp->icmp6_type));

		pkt_hdr->Assign(sindex + 4, std::move(icmp_hdr));
		break;
		}

	default:
		{
		// This is not a protocol we understand.
		break;
		}
	}

	return pkt_hdr;
	}

zeek::RecordVal* IP_Hdr::BuildPktHdrVal(zeek::RecordVal* pkt_hdr, int sindex) const
	{
	return ToPktHdrVal({zeek::AdoptRef{}, pkt_hdr}, sindex).release();
	}

static inline bool isIPv6ExtHeader(uint8_t type)
	{
	switch (type) {
	case IPPROTO_HOPOPTS:
	case IPPROTO_ROUTING:
	case IPPROTO_DSTOPTS:
	case IPPROTO_FRAGMENT:
	case IPPROTO_AH:
	case IPPROTO_ESP:
#ifdef ENABLE_MOBILE_IPV6
	case IPPROTO_MOBILITY:
#endif
		return true;
	default:
		return false;
	}
	}

IPv6_Hdr_Chain::~IPv6_Hdr_Chain()
	{
	for ( size_t i = 0; i < chain.size(); ++i ) delete chain[i];
#ifdef ENABLE_MOBILE_IPV6
	delete homeAddr;
#endif
	delete finalDst;
	}

void IPv6_Hdr_Chain::Init(const struct ip6_hdr* ip6, int total_len,
                          bool set_next, uint16_t next)
	{
	length = 0;
	uint8_t current_type, next_type;
	next_type = IPPROTO_IPV6;
	const u_char* hdrs = (const u_char*) ip6;

	if ( total_len < (int)sizeof(struct ip6_hdr) )
		{
		zeek::reporter->InternalWarning("truncated IP header in IPv6_HdrChain::Init");
		return;
		}

	do
		{
		// We can't determine a given header's length if there's less than
		// two bytes of data available (2nd byte of extension headers is length)
		if ( total_len < 2 )
			return;

		current_type = next_type;
		IPv6_Hdr* p = new IPv6_Hdr(current_type, hdrs);

		next_type = p->NextHdr();
		uint16_t cur_len = p->Length();

		// If this header is truncated, don't add it to chain, don't go further.
		if ( cur_len > total_len )
			{
			delete p;
			return;
			}

		if ( set_next && next_type == IPPROTO_FRAGMENT )
			{
			p->ChangeNext(next);
			next_type = next;
			}

		chain.push_back(p);

		// Check for routing headers and remember final destination address.
		if ( current_type == IPPROTO_ROUTING )
			ProcessRoutingHeader((const struct ip6_rthdr*) hdrs, cur_len);

#ifdef ENABLE_MOBILE_IPV6
		// Only Mobile IPv6 has a destination option we care about right now.
		if ( current_type == IPPROTO_DSTOPTS )
			ProcessDstOpts((const struct ip6_dest*) hdrs, cur_len);
#endif

		hdrs += cur_len;
		length += cur_len;
		total_len -= cur_len;

		} while ( current_type != IPPROTO_FRAGMENT &&
				  current_type != IPPROTO_ESP &&
#ifdef ENABLE_MOBILE_IPV6
				  current_type != IPPROTO_MOBILITY &&
#endif
				  isIPv6ExtHeader(next_type) );
	}

bool IPv6_Hdr_Chain::IsFragment() const
	{
	if ( chain.empty() )
		{
		zeek::reporter->InternalWarning("empty IPv6 header chain");
		return false;
		}

	return chain[chain.size()-1]->Type() == IPPROTO_FRAGMENT;
	}

IPAddr IPv6_Hdr_Chain::SrcAddr() const
	{
#ifdef ENABLE_MOBILE_IPV6
	if ( homeAddr )
		return IPAddr(*homeAddr);
#endif
	if ( chain.empty() )
		{
		zeek::reporter->InternalWarning("empty IPv6 header chain");
		return IPAddr();
		}

	return IPAddr(((const struct ip6_hdr*)(chain[0]->Data()))->ip6_src);
	}

IPAddr IPv6_Hdr_Chain::DstAddr() const
	{
	if ( finalDst )
		return IPAddr(*finalDst);

	if ( chain.empty() )
		{
		zeek::reporter->InternalWarning("empty IPv6 header chain");
		return IPAddr();
		}

	return IPAddr(((const struct ip6_hdr*)(chain[0]->Data()))->ip6_dst);
	}

void IPv6_Hdr_Chain::ProcessRoutingHeader(const struct ip6_rthdr* r, uint16_t len)
	{
	if ( finalDst )
		{
		// RFC 2460 section 4.1 says Routing should occur at most once.
		zeek::reporter->Weird(SrcAddr(), DstAddr(), "multiple_routing_headers");
		return;
		}

	// Last 16 bytes of header (for all known types) is the address we want.
	const in6_addr* addr = (const in6_addr*)(((const u_char*)r) + len - 16);

	switch ( r->ip6r_type ) {
	case 0: // Defined by RFC 2460, deprecated by RFC 5095
		{
		if ( r->ip6r_segleft > 0 && r->ip6r_len >= 2 )
			{
			if ( r->ip6r_len % 2 == 0 )
				finalDst = new IPAddr(*addr);
			else
				zeek::reporter->Weird(SrcAddr(), DstAddr(), "odd_routing0_len");
			}

		// Always raise a weird since this type is deprecated.
		zeek::reporter->Weird(SrcAddr(), DstAddr(), "routing0_hdr");
		}
		break;

#ifdef ENABLE_MOBILE_IPV6
	case 2: // Defined by Mobile IPv6 RFC 6275.
		{
		if ( r->ip6r_segleft > 0 )
			{
			if ( r->ip6r_len == 2 )
				finalDst = new IPAddr(*addr);
			else
				zeek::reporter->Weird(SrcAddr(), DstAddr(), "bad_routing2_len");
			}
		}
		break;
#endif

	default:
		zeek::reporter->Weird(SrcAddr(), DstAddr(), "unknown_routing_type",
		                      fmt("%d", r->ip6r_type));
		break;
	}
	}

#ifdef ENABLE_MOBILE_IPV6
void IPv6_Hdr_Chain::ProcessDstOpts(const struct ip6_dest* d, uint16_t len)
	{
	const u_char* data = (const u_char*) d;
	len -= 2 * sizeof(uint8_t);
	data += 2* sizeof(uint8_t);

	while ( len > 0 )
		{
		const struct ip6_opt* opt = (const struct ip6_opt*) data;
		switch ( opt->ip6o_type ) {
		case 201: // Home Address Option, Mobile IPv6 RFC 6275 section 6.3
			{
			if ( opt->ip6o_len == 16 )
				if ( homeAddr )
					zeek::reporter->Weird(SrcAddr(), DstAddr(), "multiple_home_addr_opts");
				else
					homeAddr = new IPAddr(*((const in6_addr*)(data + 2)));
			else
				zeek::reporter->Weird(SrcAddr(), DstAddr(), "bad_home_addr_len");
			}
			break;

		default:
			break;
		}

		if ( opt->ip6o_type == 0 )
			{
			data += sizeof(uint8_t);
			len -= sizeof(uint8_t);
			}
		else
			{
			data += 2 * sizeof(uint8_t) + opt->ip6o_len;
			len -= 2 * sizeof(uint8_t) + opt->ip6o_len;
			}
		}
	}
#endif

zeek::VectorValPtr IPv6_Hdr_Chain::ToVal() const
	{
	static auto ip6_ext_hdr_type = zeek::id::find_type<zeek::RecordType>("ip6_ext_hdr");
	static auto ip6_hopopts_type = zeek::id::find_type<zeek::RecordType>("ip6_hopopts");
	static auto ip6_dstopts_type = zeek::id::find_type<zeek::RecordType>("ip6_dstopts");
	static auto ip6_routing_type = zeek::id::find_type<zeek::RecordType>("ip6_routing");
	static auto ip6_fragment_type = zeek::id::find_type<zeek::RecordType>("ip6_fragment");
	static auto ip6_ah_type = zeek::id::find_type<zeek::RecordType>("ip6_ah");
	static auto ip6_esp_type = zeek::id::find_type<zeek::RecordType>("ip6_esp");
	static auto ip6_ext_hdr_chain_type = zeek::id::find_type<zeek::VectorType>("ip6_ext_hdr_chain");
	auto rval = zeek::make_intrusive<zeek::VectorVal>(ip6_ext_hdr_chain_type);

	for ( size_t i = 1; i < chain.size(); ++i )
		{
		auto v = chain[i]->ToVal();
		auto ext_hdr = zeek::make_intrusive<zeek::RecordVal>(ip6_ext_hdr_type);
		uint8_t type = chain[i]->Type();
		ext_hdr->Assign(0, zeek::val_mgr->Count(type));

		switch (type) {
		case IPPROTO_HOPOPTS:
			ext_hdr->Assign(1, std::move(v));
			break;
		case IPPROTO_DSTOPTS:
			ext_hdr->Assign(2, std::move(v));
			break;
		case IPPROTO_ROUTING:
			ext_hdr->Assign(3, std::move(v));
			break;
		case IPPROTO_FRAGMENT:
			ext_hdr->Assign(4, std::move(v));
			break;
		case IPPROTO_AH:
			ext_hdr->Assign(5, std::move(v));
			break;
		case IPPROTO_ESP:
			ext_hdr->Assign(6, std::move(v));
			break;
#ifdef ENABLE_MOBILE_IPV6
		case IPPROTO_MOBILITY:
			ext_hdr->Assign(7, std::move(v));
			break;
#endif
		default:
			zeek::reporter->InternalWarning("IPv6_Hdr_Chain bad header %d", type);
			continue;
		}

		rval->Assign(rval->Size(), std::move(ext_hdr));
		}

	return rval;
	}

zeek::VectorVal* IPv6_Hdr_Chain::BuildVal() const
	{
	return ToVal().release();
	}

IP_Hdr* IP_Hdr::Copy() const
	{
	char* new_hdr = new char[HdrLen()];

	if ( ip4 )
		{
		memcpy(new_hdr, ip4, HdrLen());
		return new IP_Hdr((const struct ip*) new_hdr, true);
		}

	memcpy(new_hdr, ip6, HdrLen());
	const struct ip6_hdr* new_ip6 = (const struct ip6_hdr*)new_hdr;
	IPv6_Hdr_Chain* new_ip6_hdrs = ip6_hdrs->Copy(new_ip6);
	return new IP_Hdr(new_ip6, true, 0, new_ip6_hdrs);
	}

IPv6_Hdr_Chain* IPv6_Hdr_Chain::Copy(const ip6_hdr* new_hdr) const
	{
	IPv6_Hdr_Chain* rval = new IPv6_Hdr_Chain;
	rval->length = length;

#ifdef ENABLE_MOBILE_IPV6
	if ( homeAddr )
		rval->homeAddr = new IPAddr(*homeAddr);
#endif

	if ( finalDst )
		rval->finalDst = new IPAddr(*finalDst);

	if ( chain.empty() )
		{
		zeek::reporter->InternalWarning("empty IPv6 header chain");
		delete rval;
		return nullptr;
		}

	const u_char* new_data = (const u_char*)new_hdr;
	const u_char* old_data = chain[0]->Data();

	for ( size_t i = 0; i < chain.size(); ++i )
		{
		int off = chain[i]->Data() - old_data;
		rval->chain.push_back(new IPv6_Hdr(chain[i]->Type(), new_data + off));
		}

	return rval;
	}

} // namespace zeek