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a2f80fdfc6
Previously we would always send an RDNSS option in the RA, making the guest try to resolve DNS through IPv6, even if the host does not actually have and IPv6 DNS server available. This makes the RDNSS option enabled only when an IPv6 DNS server is available. Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
442 lines
13 KiB
C
442 lines
13 KiB
C
/*
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* Copyright (c) 2013
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* Guillaume Subiron, Yann Bordenave, Serigne Modou Wagne.
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*/
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#include "qemu/osdep.h"
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#include "slirp.h"
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#include "ip6_icmp.h"
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#include "qemu/timer.h"
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#include "qemu/error-report.h"
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#include "qemu/log.h"
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#define NDP_Interval g_rand_int_range(slirp->grand, \
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NDP_MinRtrAdvInterval, NDP_MaxRtrAdvInterval)
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static void ra_timer_handler(void *opaque)
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{
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Slirp *slirp = opaque;
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timer_mod(slirp->ra_timer,
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qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + NDP_Interval);
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ndp_send_ra(slirp);
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}
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void icmp6_init(Slirp *slirp)
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{
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if (!slirp->in6_enabled) {
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return;
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}
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slirp->ra_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, ra_timer_handler, slirp);
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timer_mod(slirp->ra_timer,
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qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + NDP_Interval);
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}
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void icmp6_cleanup(Slirp *slirp)
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{
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if (!slirp->in6_enabled) {
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return;
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}
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timer_del(slirp->ra_timer);
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timer_free(slirp->ra_timer);
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}
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static void icmp6_send_echoreply(struct mbuf *m, Slirp *slirp, struct ip6 *ip,
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struct icmp6 *icmp)
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{
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struct mbuf *t = m_get(slirp);
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t->m_len = sizeof(struct ip6) + ntohs(ip->ip_pl);
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memcpy(t->m_data, m->m_data, t->m_len);
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/* IPv6 Packet */
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struct ip6 *rip = mtod(t, struct ip6 *);
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rip->ip_dst = ip->ip_src;
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rip->ip_src = ip->ip_dst;
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/* ICMPv6 packet */
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t->m_data += sizeof(struct ip6);
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struct icmp6 *ricmp = mtod(t, struct icmp6 *);
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ricmp->icmp6_type = ICMP6_ECHO_REPLY;
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ricmp->icmp6_cksum = 0;
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/* Checksum */
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t->m_data -= sizeof(struct ip6);
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ricmp->icmp6_cksum = ip6_cksum(t);
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ip6_output(NULL, t, 0);
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}
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void icmp6_send_error(struct mbuf *m, uint8_t type, uint8_t code)
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{
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Slirp *slirp = m->slirp;
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struct mbuf *t;
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struct ip6 *ip = mtod(m, struct ip6 *);
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DEBUG_CALL("icmp6_send_error");
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DEBUG_ARGS((dfd, " type = %d, code = %d\n", type, code));
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if (IN6_IS_ADDR_MULTICAST(&ip->ip_src) ||
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IN6_IS_ADDR_UNSPECIFIED(&ip->ip_src)) {
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/* TODO icmp error? */
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return;
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}
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t = m_get(slirp);
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/* IPv6 packet */
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struct ip6 *rip = mtod(t, struct ip6 *);
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rip->ip_src = (struct in6_addr)LINKLOCAL_ADDR;
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rip->ip_dst = ip->ip_src;
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#if !defined(_WIN32) || (_WIN32_WINNT >= 0x0600)
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char addrstr[INET6_ADDRSTRLEN];
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inet_ntop(AF_INET6, &rip->ip_dst, addrstr, INET6_ADDRSTRLEN);
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DEBUG_ARG("target = %s", addrstr);
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#endif
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rip->ip_nh = IPPROTO_ICMPV6;
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const int error_data_len = MIN(m->m_len,
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IF_MTU - (sizeof(struct ip6) + ICMP6_ERROR_MINLEN));
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rip->ip_pl = htons(ICMP6_ERROR_MINLEN + error_data_len);
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t->m_len = sizeof(struct ip6) + ntohs(rip->ip_pl);
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/* ICMPv6 packet */
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t->m_data += sizeof(struct ip6);
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struct icmp6 *ricmp = mtod(t, struct icmp6 *);
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ricmp->icmp6_type = type;
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ricmp->icmp6_code = code;
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ricmp->icmp6_cksum = 0;
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switch (type) {
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case ICMP6_UNREACH:
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case ICMP6_TIMXCEED:
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ricmp->icmp6_err.unused = 0;
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break;
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case ICMP6_TOOBIG:
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ricmp->icmp6_err.mtu = htonl(IF_MTU);
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break;
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case ICMP6_PARAMPROB:
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/* TODO: Handle this case */
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break;
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default:
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g_assert_not_reached();
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break;
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}
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t->m_data += ICMP6_ERROR_MINLEN;
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memcpy(t->m_data, m->m_data, error_data_len);
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/* Checksum */
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t->m_data -= ICMP6_ERROR_MINLEN;
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t->m_data -= sizeof(struct ip6);
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ricmp->icmp6_cksum = ip6_cksum(t);
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ip6_output(NULL, t, 0);
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}
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/*
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* Send NDP Router Advertisement
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*/
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void ndp_send_ra(Slirp *slirp)
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{
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DEBUG_CALL("ndp_send_ra");
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/* Build IPv6 packet */
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struct mbuf *t = m_get(slirp);
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struct ip6 *rip = mtod(t, struct ip6 *);
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size_t pl_size = 0;
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struct in6_addr addr;
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uint32_t scope_id;
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rip->ip_src = (struct in6_addr)LINKLOCAL_ADDR;
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rip->ip_dst = (struct in6_addr)ALLNODES_MULTICAST;
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rip->ip_nh = IPPROTO_ICMPV6;
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/* Build ICMPv6 packet */
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t->m_data += sizeof(struct ip6);
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struct icmp6 *ricmp = mtod(t, struct icmp6 *);
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ricmp->icmp6_type = ICMP6_NDP_RA;
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ricmp->icmp6_code = 0;
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ricmp->icmp6_cksum = 0;
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/* NDP */
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ricmp->icmp6_nra.chl = NDP_AdvCurHopLimit;
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ricmp->icmp6_nra.M = NDP_AdvManagedFlag;
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ricmp->icmp6_nra.O = NDP_AdvOtherConfigFlag;
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ricmp->icmp6_nra.reserved = 0;
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ricmp->icmp6_nra.lifetime = htons(NDP_AdvDefaultLifetime);
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ricmp->icmp6_nra.reach_time = htonl(NDP_AdvReachableTime);
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ricmp->icmp6_nra.retrans_time = htonl(NDP_AdvRetransTime);
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t->m_data += ICMP6_NDP_RA_MINLEN;
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pl_size += ICMP6_NDP_RA_MINLEN;
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/* Source link-layer address (NDP option) */
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struct ndpopt *opt = mtod(t, struct ndpopt *);
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opt->ndpopt_type = NDPOPT_LINKLAYER_SOURCE;
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opt->ndpopt_len = NDPOPT_LINKLAYER_LEN / 8;
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in6_compute_ethaddr(rip->ip_src, opt->ndpopt_linklayer);
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t->m_data += NDPOPT_LINKLAYER_LEN;
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pl_size += NDPOPT_LINKLAYER_LEN;
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/* Prefix information (NDP option) */
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struct ndpopt *opt2 = mtod(t, struct ndpopt *);
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opt2->ndpopt_type = NDPOPT_PREFIX_INFO;
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opt2->ndpopt_len = NDPOPT_PREFIXINFO_LEN / 8;
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opt2->ndpopt_prefixinfo.prefix_length = slirp->vprefix_len;
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opt2->ndpopt_prefixinfo.L = 1;
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opt2->ndpopt_prefixinfo.A = 1;
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opt2->ndpopt_prefixinfo.reserved1 = 0;
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opt2->ndpopt_prefixinfo.valid_lt = htonl(NDP_AdvValidLifetime);
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opt2->ndpopt_prefixinfo.pref_lt = htonl(NDP_AdvPrefLifetime);
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opt2->ndpopt_prefixinfo.reserved2 = 0;
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opt2->ndpopt_prefixinfo.prefix = slirp->vprefix_addr6;
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t->m_data += NDPOPT_PREFIXINFO_LEN;
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pl_size += NDPOPT_PREFIXINFO_LEN;
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/* Prefix information (NDP option) */
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if (get_dns6_addr(&addr, &scope_id) >= 0) {
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/* Host system does have an IPv6 DNS server, announce our proxy. */
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struct ndpopt *opt3 = mtod(t, struct ndpopt *);
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opt3->ndpopt_type = NDPOPT_RDNSS;
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opt3->ndpopt_len = NDPOPT_RDNSS_LEN / 8;
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opt3->ndpopt_rdnss.reserved = 0;
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opt3->ndpopt_rdnss.lifetime = htonl(2 * NDP_MaxRtrAdvInterval);
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opt3->ndpopt_rdnss.addr = slirp->vnameserver_addr6;
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t->m_data += NDPOPT_RDNSS_LEN;
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pl_size += NDPOPT_RDNSS_LEN;
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}
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rip->ip_pl = htons(pl_size);
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t->m_data -= sizeof(struct ip6) + pl_size;
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t->m_len = sizeof(struct ip6) + pl_size;
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/* ICMPv6 Checksum */
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ricmp->icmp6_cksum = ip6_cksum(t);
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ip6_output(NULL, t, 0);
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}
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/*
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* Send NDP Neighbor Solitication
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*/
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void ndp_send_ns(Slirp *slirp, struct in6_addr addr)
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{
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DEBUG_CALL("ndp_send_ns");
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#if !defined(_WIN32) || (_WIN32_WINNT >= 0x0600)
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char addrstr[INET6_ADDRSTRLEN];
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inet_ntop(AF_INET6, &addr, addrstr, INET6_ADDRSTRLEN);
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DEBUG_ARG("target = %s", addrstr);
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#endif
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/* Build IPv6 packet */
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struct mbuf *t = m_get(slirp);
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struct ip6 *rip = mtod(t, struct ip6 *);
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rip->ip_src = slirp->vhost_addr6;
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rip->ip_dst = (struct in6_addr)SOLICITED_NODE_PREFIX;
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memcpy(&rip->ip_dst.s6_addr[13], &addr.s6_addr[13], 3);
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rip->ip_nh = IPPROTO_ICMPV6;
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rip->ip_pl = htons(ICMP6_NDP_NS_MINLEN + NDPOPT_LINKLAYER_LEN);
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t->m_len = sizeof(struct ip6) + ntohs(rip->ip_pl);
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/* Build ICMPv6 packet */
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t->m_data += sizeof(struct ip6);
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struct icmp6 *ricmp = mtod(t, struct icmp6 *);
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ricmp->icmp6_type = ICMP6_NDP_NS;
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ricmp->icmp6_code = 0;
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ricmp->icmp6_cksum = 0;
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/* NDP */
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ricmp->icmp6_nns.reserved = 0;
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ricmp->icmp6_nns.target = addr;
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/* Build NDP option */
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t->m_data += ICMP6_NDP_NS_MINLEN;
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struct ndpopt *opt = mtod(t, struct ndpopt *);
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opt->ndpopt_type = NDPOPT_LINKLAYER_SOURCE;
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opt->ndpopt_len = NDPOPT_LINKLAYER_LEN / 8;
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in6_compute_ethaddr(slirp->vhost_addr6, opt->ndpopt_linklayer);
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/* ICMPv6 Checksum */
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t->m_data -= ICMP6_NDP_NA_MINLEN;
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t->m_data -= sizeof(struct ip6);
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ricmp->icmp6_cksum = ip6_cksum(t);
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ip6_output(NULL, t, 1);
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}
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/*
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* Send NDP Neighbor Advertisement
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*/
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static void ndp_send_na(Slirp *slirp, struct ip6 *ip, struct icmp6 *icmp)
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{
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/* Build IPv6 packet */
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struct mbuf *t = m_get(slirp);
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struct ip6 *rip = mtod(t, struct ip6 *);
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rip->ip_src = icmp->icmp6_nns.target;
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if (IN6_IS_ADDR_UNSPECIFIED(&ip->ip_src)) {
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rip->ip_dst = (struct in6_addr)ALLNODES_MULTICAST;
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} else {
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rip->ip_dst = ip->ip_src;
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}
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rip->ip_nh = IPPROTO_ICMPV6;
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rip->ip_pl = htons(ICMP6_NDP_NA_MINLEN
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+ NDPOPT_LINKLAYER_LEN);
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t->m_len = sizeof(struct ip6) + ntohs(rip->ip_pl);
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/* Build ICMPv6 packet */
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t->m_data += sizeof(struct ip6);
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struct icmp6 *ricmp = mtod(t, struct icmp6 *);
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ricmp->icmp6_type = ICMP6_NDP_NA;
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ricmp->icmp6_code = 0;
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ricmp->icmp6_cksum = 0;
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/* NDP */
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ricmp->icmp6_nna.R = NDP_IsRouter;
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ricmp->icmp6_nna.S = !IN6_IS_ADDR_MULTICAST(&rip->ip_dst);
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ricmp->icmp6_nna.O = 1;
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ricmp->icmp6_nna.reserved_hi = 0;
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ricmp->icmp6_nna.reserved_lo = 0;
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ricmp->icmp6_nna.target = icmp->icmp6_nns.target;
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/* Build NDP option */
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t->m_data += ICMP6_NDP_NA_MINLEN;
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struct ndpopt *opt = mtod(t, struct ndpopt *);
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opt->ndpopt_type = NDPOPT_LINKLAYER_TARGET;
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opt->ndpopt_len = NDPOPT_LINKLAYER_LEN / 8;
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in6_compute_ethaddr(ricmp->icmp6_nna.target,
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opt->ndpopt_linklayer);
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/* ICMPv6 Checksum */
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t->m_data -= ICMP6_NDP_NA_MINLEN;
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t->m_data -= sizeof(struct ip6);
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ricmp->icmp6_cksum = ip6_cksum(t);
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ip6_output(NULL, t, 0);
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}
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/*
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* Process a NDP message
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*/
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static void ndp_input(struct mbuf *m, Slirp *slirp, struct ip6 *ip,
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struct icmp6 *icmp)
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{
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m->m_len += ETH_HLEN;
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m->m_data -= ETH_HLEN;
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struct ethhdr *eth = mtod(m, struct ethhdr *);
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m->m_len -= ETH_HLEN;
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m->m_data += ETH_HLEN;
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switch (icmp->icmp6_type) {
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case ICMP6_NDP_RS:
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DEBUG_CALL(" type = Router Solicitation");
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if (ip->ip_hl == 255
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&& icmp->icmp6_code == 0
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&& ntohs(ip->ip_pl) >= ICMP6_NDP_RS_MINLEN) {
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/* Gratuitous NDP */
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ndp_table_add(slirp, ip->ip_src, eth->h_source);
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ndp_send_ra(slirp);
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}
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break;
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case ICMP6_NDP_RA:
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DEBUG_CALL(" type = Router Advertisement");
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qemu_log_mask(LOG_GUEST_ERROR,
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"Warning: guest sent NDP RA, but shouldn't");
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break;
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case ICMP6_NDP_NS:
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DEBUG_CALL(" type = Neighbor Solicitation");
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if (ip->ip_hl == 255
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&& icmp->icmp6_code == 0
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&& !IN6_IS_ADDR_MULTICAST(&icmp->icmp6_nns.target)
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&& ntohs(ip->ip_pl) >= ICMP6_NDP_NS_MINLEN
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&& (!IN6_IS_ADDR_UNSPECIFIED(&ip->ip_src)
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|| in6_solicitednode_multicast(&ip->ip_dst))) {
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if (in6_equal_host(&icmp->icmp6_nns.target)) {
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/* Gratuitous NDP */
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ndp_table_add(slirp, ip->ip_src, eth->h_source);
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ndp_send_na(slirp, ip, icmp);
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}
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}
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break;
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case ICMP6_NDP_NA:
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DEBUG_CALL(" type = Neighbor Advertisement");
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if (ip->ip_hl == 255
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&& icmp->icmp6_code == 0
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&& ntohs(ip->ip_pl) >= ICMP6_NDP_NA_MINLEN
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&& !IN6_IS_ADDR_MULTICAST(&icmp->icmp6_nna.target)
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&& (!IN6_IS_ADDR_MULTICAST(&ip->ip_dst)
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|| icmp->icmp6_nna.S == 0)) {
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ndp_table_add(slirp, ip->ip_src, eth->h_source);
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}
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break;
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case ICMP6_NDP_REDIRECT:
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DEBUG_CALL(" type = Redirect");
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qemu_log_mask(LOG_GUEST_ERROR,
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"Warning: guest sent NDP REDIRECT, but shouldn't");
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break;
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}
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}
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/*
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* Process a received ICMPv6 message.
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*/
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void icmp6_input(struct mbuf *m)
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{
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struct icmp6 *icmp;
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struct ip6 *ip = mtod(m, struct ip6 *);
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Slirp *slirp = m->slirp;
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int hlen = sizeof(struct ip6);
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DEBUG_CALL("icmp6_input");
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DEBUG_ARG("m = %lx", (long) m);
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DEBUG_ARG("m_len = %d", m->m_len);
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if (ntohs(ip->ip_pl) < ICMP6_MINLEN) {
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goto end;
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}
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if (ip6_cksum(m)) {
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goto end;
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}
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m->m_len -= hlen;
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m->m_data += hlen;
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icmp = mtod(m, struct icmp6 *);
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m->m_len += hlen;
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m->m_data -= hlen;
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DEBUG_ARG("icmp6_type = %d", icmp->icmp6_type);
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switch (icmp->icmp6_type) {
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case ICMP6_ECHO_REQUEST:
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if (in6_equal_host(&ip->ip_dst)) {
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icmp6_send_echoreply(m, slirp, ip, icmp);
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} else {
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/* TODO */
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error_report("external icmpv6 not supported yet");
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}
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break;
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case ICMP6_NDP_RS:
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case ICMP6_NDP_RA:
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case ICMP6_NDP_NS:
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case ICMP6_NDP_NA:
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case ICMP6_NDP_REDIRECT:
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ndp_input(m, slirp, ip, icmp);
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break;
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case ICMP6_UNREACH:
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case ICMP6_TOOBIG:
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case ICMP6_TIMXCEED:
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case ICMP6_PARAMPROB:
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/* XXX? report error? close socket? */
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default:
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break;
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}
|
|
|
|
end:
|
|
m_free(m);
|
|
}
|