slirp: Adding IPv6, ICMPv6 Echo and NDP autoconfiguration

This patch adds the functions needed to handle IPv6 packets. ICMPv6 and
NDP headers are implemented.

Slirp is now able to send NDP Router or Neighbor Advertisement when it
receives Router or Neighbor Solicitation. Using a 64bit-sized IPv6
prefix, the guest is now able to perform stateless autoconfiguration
(SLAAC) and to compute its IPv6 address.

This patch adds an ndp_table, mainly inspired by arp_table, to keep an
NDP cache and manage network address resolution.
Slirp regularly sends NDP Neighbor Advertisement, as recommended by the
RFC, to make the guest refresh its route.

This also adds ip6_cksum() to compute ICMPv6 checksums using IPv6
pseudo-header.

Some #define ETH_* are moved upper in slirp.h to make them accessible to
other slirp/*.h

Signed-off-by: Guillaume Subiron <maethor@subiron.org>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>

12 files changed, 1019 insertions, 6 deletions

diff --git a/slirp/Makefile.objs b/slirp/Makefile.objs
index 2daa9dc58d..4e3a289b08 100644
--- a/slirp/Makefile.objs
+++ b/slirp/Makefile.objs
@@ -1,3 +1,5 @@
-common-obj-y = cksum.o if.o ip_icmp.o ip_input.o ip_output.o dnssearch.o
+common-obj-y = cksum.o if.o ip_icmp.o ip6_icmp.o ip6_input.o ip6_output.o \
+               ip_input.o ip_output.o dnssearch.o
 common-obj-y += slirp.o mbuf.o misc.o sbuf.o socket.o tcp_input.o tcp_output.o
-common-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o arp_table.o
+common-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o arp_table.o \
+                ndp_table.o
diff --git a/slirp/cksum.c b/slirp/cksum.c
index bc0d017d24..2ad0e6540d 100644
--- a/slirp/cksum.c
+++ b/slirp/cksum.c
@@ -138,3 +138,28 @@ cont:
 	REDUCE;
 	return (~sum & 0xffff);
 }
+
+int ip6_cksum(struct mbuf *m)
+{
+    /* TODO: Optimize this by being able to pass the ip6_pseudohdr to cksum
+     * separately from the mbuf */
+    struct ip6 save_ip, *ip = mtod(m, struct ip6 *);
+    struct ip6_pseudohdr *ih = mtod(m, struct ip6_pseudohdr *);
+    int sum;
+
+    save_ip = *ip;
+
+    ih->ih_src = save_ip.ip_src;
+    ih->ih_dst = save_ip.ip_dst;
+    ih->ih_pl = htonl((uint32_t)ntohs(save_ip.ip_pl));
+    ih->ih_zero_hi = 0;
+    ih->ih_zero_lo = 0;
+    ih->ih_nh = save_ip.ip_nh;
+
+    sum = cksum(m, ((int)sizeof(struct ip6_pseudohdr))
+                    + ntohl(ih->ih_pl));
+
+    *ip = save_ip;
+
+    return sum;
+}
diff --git a/slirp/if.c b/slirp/if.c
index 93d7cc0b43..2e21f438e8 100644
--- a/slirp/if.c
+++ b/slirp/if.c
@@ -194,7 +194,7 @@ void if_start(Slirp *slirp)
 
         /* Try to send packet unless it already expired */
         if (ifm->expiration_date >= now && !if_encap(slirp, ifm)) {
-            /* Packet is delayed due to pending ARP resolution */
+            /* Packet is delayed due to pending ARP or NDP resolution */
             continue;
         }
 
diff --git a/slirp/ip6.h b/slirp/ip6.h
new file mode 100644
index 0000000000..731ee72d77
--- /dev/null
+++ b/slirp/ip6.h
@@ -0,0 +1,137 @@
+/*
+ * Copyright (c) 2013
+ * Guillaume Subiron, Yann Bordenave, Serigne Modou Wagne.
+ */
+
+#ifndef SLIRP_IP6_H_
+#define SLIRP_IP6_H_
+
+#include "net/eth.h"
+
+#define ALLNODES_MULTICAST  { .s6_addr = \
+                            { 0xff, 0x02, 0x00, 0x00,\
+                            0x00, 0x00, 0x00, 0x00,\
+                            0x00, 0x00, 0x00, 0x00,\
+                            0x00, 0x00, 0x00, 0x01 } }
+
+#define SOLICITED_NODE_PREFIX { .s6_addr = \
+                            { 0xff, 0x02, 0x00, 0x00,\
+                            0x00, 0x00, 0x00, 0x00,\
+                            0x00, 0x00, 0x00, 0x01,\
+                            0xff, 0x00, 0x00, 0x00 } }
+
+#define LINKLOCAL_ADDR  { .s6_addr = \
+                        { 0xfe, 0x80, 0x00, 0x00,\
+                        0x00, 0x00, 0x00, 0x00,\
+                        0x00, 0x00, 0x00, 0x00,\
+                        0x00, 0x00, 0x00, 0x02 } }
+
+static inline bool in6_equal(const struct in6_addr *a, const struct in6_addr *b)
+{
+    return memcmp(a, b, sizeof(*a)) == 0;
+}
+
+static inline bool in6_equal_net(const struct in6_addr *a,
+                                 const struct in6_addr *b,
+                                 int prefix_len)
+{
+    if (memcmp(a, b, prefix_len / 8) != 0) {
+        return 0;
+    }
+
+    if (prefix_len % 8 == 0) {
+        return 1;
+    }
+
+    return a->s6_addr[prefix_len / 8] >> (8 - (prefix_len % 8))
+        == b->s6_addr[prefix_len / 8] >> (8 - (prefix_len % 8));
+}
+
+static inline bool in6_equal_mach(const struct in6_addr *a,
+                                  const struct in6_addr *b,
+                                  int prefix_len)
+{
+    if (memcmp(&(a->s6_addr[(prefix_len + 7) / 8]),
+               &(b->s6_addr[(prefix_len + 7) / 8]),
+               16 - (prefix_len + 7) / 8) != 0) {
+        return 0;
+    }
+
+    if (prefix_len % 8 == 0) {
+        return 1;
+    }
+
+    return (a->s6_addr[prefix_len / 8] & ((1U << (8 - (prefix_len % 8))) - 1))
+        == (b->s6_addr[prefix_len / 8] & ((1U << (8 - (prefix_len % 8))) - 1));
+}
+
+
+#define in6_equal_router(a)\
+    ((in6_equal_net(a, &slirp->vprefix_addr6, slirp->vprefix_len)\
+      && in6_equal_mach(a, &slirp->vhost_addr6, slirp->vprefix_len))\
+  || (in6_equal_net(a, &(struct in6_addr)LINKLOCAL_ADDR, 64)\
+      && in6_equal_mach(a, &slirp->vhost_addr6, 64)))
+
+#define in6_equal_dns(a) 0
+
+#define in6_equal_host(a)\
+    (in6_equal_router(a) || in6_equal_dns(a))
+
+#define in6_solicitednode_multicast(a)\
+    (in6_equal_net(a, &(struct in6_addr)SOLICITED_NODE_PREFIX, 104))
+
+/* Compute emulated host MAC address from its ipv6 address */
+static inline void in6_compute_ethaddr(struct in6_addr ip,
+                                       uint8_t eth[ETH_ALEN])
+{
+    eth[0] = 0x52;
+    eth[1] = 0x56;
+    memcpy(&eth[2], &ip.s6_addr[16 - (ETH_ALEN - 2)], ETH_ALEN - 2);
+}
+
+/*
+ * Definitions for internet protocol version 6.
+ * Per RFC 2460, December 1998.
+ */
+#define IP6VERSION      6
+#define IP6_HOP_LIMIT 255
+
+/*
+ * Structure of an internet header, naked of options.
+ */
+struct ip6 {
+#ifdef HOST_WORDS_BIGENDIAN
+    uint32_t
+        ip_v:4,         /* version */
+        ip_tc_hi:4,     /* traffic class */
+        ip_tc_lo:4,
+        ip_fl_hi:4,     /* flow label */
+        ip_fl_lo:16;
+#else
+    uint32_t
+        ip_tc_hi:4,
+        ip_v:4,
+        ip_fl_hi:4,
+        ip_tc_lo:4,
+        ip_fl_lo:16;
+#endif
+    uint16_t    ip_pl;               /* payload length */
+    uint8_t     ip_nh;               /* next header */
+    uint8_t     ip_hl;               /* hop limit */
+    struct in6_addr ip_src, ip_dst;  /* source and dest address */
+} QEMU_PACKED;
+
+/*
+ * IPv6 pseudo-header used by upper-layer protocols
+ */
+struct ip6_pseudohdr {
+    struct      in6_addr ih_src;  /* source internet address */
+    struct      in6_addr ih_dst;  /* destination internet address */
+    uint32_t    ih_pl;            /* upper-layer packet length */
+    uint16_t    ih_zero_hi;       /* zero */
+    uint8_t     ih_zero_lo;       /* zero */
+    uint8_t     ih_nh;            /* next header */
+} QEMU_PACKED;
+
+
+#endif
diff --git a/slirp/ip6_icmp.c b/slirp/ip6_icmp.c
new file mode 100644
index 0000000000..9f3fd4a332
--- /dev/null
+++ b/slirp/ip6_icmp.c
@@ -0,0 +1,350 @@
+/*
+ * Copyright (c) 2013
+ * Guillaume Subiron, Yann Bordenave, Serigne Modou Wagne.
+ */
+
+#include "qemu/osdep.h"
+#include "slirp.h"
+#include "ip6_icmp.h"
+#include "qemu/timer.h"
+#include "qemu/error-report.h"
+#include "qemu/log.h"
+#include <time.h>
+
+#define NDP_Interval g_rand_int_range(slirp->grand, \
+        NDP_MinRtrAdvInterval, NDP_MaxRtrAdvInterval)
+
+static void ra_timer_handler(void *opaque)
+{
+    Slirp *slirp = opaque;
+    timer_mod(slirp->ra_timer,
+              qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + NDP_Interval);
+    ndp_send_ra(slirp);
+}
+
+void icmp6_init(Slirp *slirp)
+{
+    slirp->ra_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, ra_timer_handler, slirp);
+    timer_mod(slirp->ra_timer,
+              qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + NDP_Interval);
+}
+
+void icmp6_cleanup(Slirp *slirp)
+{
+    timer_del(slirp->ra_timer);
+    timer_free(slirp->ra_timer);
+}
+
+static void icmp6_send_echoreply(struct mbuf *m, Slirp *slirp, struct ip6 *ip,
+        struct icmp6 *icmp)
+{
+    struct mbuf *t = m_get(slirp);
+    t->m_len = sizeof(struct ip6) + ntohs(ip->ip_pl);
+    memcpy(t->m_data, m->m_data, t->m_len);
+
+    /* IPv6 Packet */
+    struct ip6 *rip = mtod(t, struct ip6 *);
+    rip->ip_dst = ip->ip_src;
+    rip->ip_src = ip->ip_dst;
+
+    /* ICMPv6 packet */
+    t->m_data += sizeof(struct ip6);
+    struct icmp6 *ricmp = mtod(t, struct icmp6 *);
+    ricmp->icmp6_type = ICMP6_ECHO_REPLY;
+    ricmp->icmp6_cksum = 0;
+
+    /* Checksum */
+    t->m_data -= sizeof(struct ip6);
+    ricmp->icmp6_cksum = ip6_cksum(t);
+
+    ip6_output(NULL, t, 0);
+}
+
+/*
+ * Send NDP Router Advertisement
+ */
+void ndp_send_ra(Slirp *slirp)
+{
+    DEBUG_CALL("ndp_send_ra");
+
+    /* Build IPv6 packet */
+    struct mbuf *t = m_get(slirp);
+    struct ip6 *rip = mtod(t, struct ip6 *);
+    rip->ip_src = (struct in6_addr)LINKLOCAL_ADDR;
+    rip->ip_dst = (struct in6_addr)ALLNODES_MULTICAST;
+    rip->ip_nh = IPPROTO_ICMPV6;
+    rip->ip_pl = htons(ICMP6_NDP_RA_MINLEN
+                        + NDPOPT_LINKLAYER_LEN
+                        + NDPOPT_PREFIXINFO_LEN);
+    t->m_len = sizeof(struct ip6) + ntohs(rip->ip_pl);
+
+    /* Build ICMPv6 packet */
+    t->m_data += sizeof(struct ip6);
+    struct icmp6 *ricmp = mtod(t, struct icmp6 *);
+    ricmp->icmp6_type = ICMP6_NDP_RA;
+    ricmp->icmp6_code = 0;
+    ricmp->icmp6_cksum = 0;
+
+    /* NDP */
+    ricmp->icmp6_nra.chl = NDP_AdvCurHopLimit;
+    ricmp->icmp6_nra.M = NDP_AdvManagedFlag;
+    ricmp->icmp6_nra.O = NDP_AdvOtherConfigFlag;
+    ricmp->icmp6_nra.reserved = 0;
+    ricmp->icmp6_nra.lifetime = htons(NDP_AdvDefaultLifetime);
+    ricmp->icmp6_nra.reach_time = htonl(NDP_AdvReachableTime);
+    ricmp->icmp6_nra.retrans_time = htonl(NDP_AdvRetransTime);
+
+    /* Source link-layer address (NDP option) */
+    t->m_data += ICMP6_NDP_RA_MINLEN;
+    struct ndpopt *opt = mtod(t, struct ndpopt *);
+    opt->ndpopt_type = NDPOPT_LINKLAYER_SOURCE;
+    opt->ndpopt_len = NDPOPT_LINKLAYER_LEN / 8;
+    in6_compute_ethaddr(rip->ip_src, opt->ndpopt_linklayer);
+
+    /* Prefix information (NDP option) */
+    t->m_data += NDPOPT_LINKLAYER_LEN;
+    struct ndpopt *opt2 = mtod(t, struct ndpopt *);
+    opt2->ndpopt_type = NDPOPT_PREFIX_INFO;
+    opt2->ndpopt_len = NDPOPT_PREFIXINFO_LEN / 8;
+    opt2->ndpopt_prefixinfo.prefix_length = slirp->vprefix_len;
+    opt2->ndpopt_prefixinfo.L = 1;
+    opt2->ndpopt_prefixinfo.A = 1;
+    opt2->ndpopt_prefixinfo.reserved1 = 0;
+    opt2->ndpopt_prefixinfo.valid_lt = htonl(NDP_AdvValidLifetime);
+    opt2->ndpopt_prefixinfo.pref_lt = htonl(NDP_AdvPrefLifetime);
+    opt2->ndpopt_prefixinfo.reserved2 = 0;
+    opt2->ndpopt_prefixinfo.prefix = slirp->vprefix_addr6;
+
+    /* ICMPv6 Checksum */
+    t->m_data -= NDPOPT_LINKLAYER_LEN;
+    t->m_data -= ICMP6_NDP_RA_MINLEN;
+    t->m_data -= sizeof(struct ip6);
+    ricmp->icmp6_cksum = ip6_cksum(t);
+
+    ip6_output(NULL, t, 0);
+}
+
+/*
+ * Send NDP Neighbor Solitication
+ */
+void ndp_send_ns(Slirp *slirp, struct in6_addr addr)
+{
+    DEBUG_CALL("ndp_send_ns");
+#if !defined(_WIN32) || (_WIN32_WINNT >= 0x0600)
+    char addrstr[INET6_ADDRSTRLEN];
+    inet_ntop(AF_INET6, &addr, addrstr, INET6_ADDRSTRLEN);
+    DEBUG_ARG("target = %s", addrstr);
+#endif
+
+    /* Build IPv6 packet */
+    struct mbuf *t = m_get(slirp);
+    struct ip6 *rip = mtod(t, struct ip6 *);
+    rip->ip_src = slirp->vhost_addr6;
+    rip->ip_dst = (struct in6_addr)SOLICITED_NODE_PREFIX;
+    memcpy(&rip->ip_dst.s6_addr[13], &addr.s6_addr[13], 3);
+    rip->ip_nh = IPPROTO_ICMPV6;
+    rip->ip_pl = htons(ICMP6_NDP_NS_MINLEN + NDPOPT_LINKLAYER_LEN);
+    t->m_len = sizeof(struct ip6) + ntohs(rip->ip_pl);
+
+    /* Build ICMPv6 packet */
+    t->m_data += sizeof(struct ip6);
+    struct icmp6 *ricmp = mtod(t, struct icmp6 *);
+    ricmp->icmp6_type = ICMP6_NDP_NS;
+    ricmp->icmp6_code = 0;
+    ricmp->icmp6_cksum = 0;
+
+    /* NDP */
+    ricmp->icmp6_nns.reserved = 0;
+    ricmp->icmp6_nns.target = addr;
+
+    /* Build NDP option */
+    t->m_data += ICMP6_NDP_NS_MINLEN;
+    struct ndpopt *opt = mtod(t, struct ndpopt *);
+    opt->ndpopt_type = NDPOPT_LINKLAYER_SOURCE;
+    opt->ndpopt_len = NDPOPT_LINKLAYER_LEN / 8;
+    in6_compute_ethaddr(slirp->vhost_addr6, opt->ndpopt_linklayer);
+
+    /* ICMPv6 Checksum */
+    t->m_data -= ICMP6_NDP_NA_MINLEN;
+    t->m_data -= sizeof(struct ip6);
+    ricmp->icmp6_cksum = ip6_cksum(t);
+
+    ip6_output(NULL, t, 1);
+}
+
+/*
+ * Send NDP Neighbor Advertisement
+ */
+static void ndp_send_na(Slirp *slirp, struct ip6 *ip, struct icmp6 *icmp)
+{
+    /* Build IPv6 packet */
+    struct mbuf *t = m_get(slirp);
+    struct ip6 *rip = mtod(t, struct ip6 *);
+    rip->ip_src = icmp->icmp6_nns.target;
+    if (IN6_IS_ADDR_UNSPECIFIED(&ip->ip_src)) {
+        rip->ip_dst = (struct in6_addr)ALLNODES_MULTICAST;
+    } else {
+        rip->ip_dst = ip->ip_src;
+    }
+    rip->ip_nh = IPPROTO_ICMPV6;
+    rip->ip_pl = htons(ICMP6_NDP_NA_MINLEN
+                        + NDPOPT_LINKLAYER_LEN);
+    t->m_len = sizeof(struct ip6) + ntohs(rip->ip_pl);
+
+    /* Build ICMPv6 packet */
+    t->m_data += sizeof(struct ip6);
+    struct icmp6 *ricmp = mtod(t, struct icmp6 *);
+    ricmp->icmp6_type = ICMP6_NDP_NA;
+    ricmp->icmp6_code = 0;
+    ricmp->icmp6_cksum = 0;
+
+    /* NDP */
+    ricmp->icmp6_nna.R = NDP_IsRouter;
+    ricmp->icmp6_nna.S = !IN6_IS_ADDR_MULTICAST(&rip->ip_dst);
+    ricmp->icmp6_nna.O = 1;
+    ricmp->icmp6_nna.reserved_hi = 0;
+    ricmp->icmp6_nna.reserved_lo = 0;
+    ricmp->icmp6_nna.target = icmp->icmp6_nns.target;
+
+    /* Build NDP option */
+    t->m_data += ICMP6_NDP_NA_MINLEN;
+    struct ndpopt *opt = mtod(t, struct ndpopt *);
+    opt->ndpopt_type = NDPOPT_LINKLAYER_TARGET;
+    opt->ndpopt_len = NDPOPT_LINKLAYER_LEN / 8;
+    in6_compute_ethaddr(ricmp->icmp6_nna.target,
+                    opt->ndpopt_linklayer);
+
+    /* ICMPv6 Checksum */
+    t->m_data -= ICMP6_NDP_NA_MINLEN;
+    t->m_data -= sizeof(struct ip6);
+    ricmp->icmp6_cksum = ip6_cksum(t);
+
+    ip6_output(NULL, t, 0);
+}
+
+/*
+ * Process a NDP message
+ */
+static void ndp_input(struct mbuf *m, Slirp *slirp, struct ip6 *ip,
+        struct icmp6 *icmp)
+{
+    m->m_len += ETH_HLEN;
+    m->m_data -= ETH_HLEN;
+    struct ethhdr *eth = mtod(m, struct ethhdr *);
+    m->m_len -= ETH_HLEN;
+    m->m_data += ETH_HLEN;
+
+    switch (icmp->icmp6_type) {
+    case ICMP6_NDP_RS:
+        DEBUG_CALL(" type = Router Solicitation");
+        if (ip->ip_hl == 255
+                && icmp->icmp6_code == 0
+                && ntohs(ip->ip_pl) >= ICMP6_NDP_RS_MINLEN) {
+            /* Gratuitous NDP */
+            ndp_table_add(slirp, ip->ip_src, eth->h_source);
+
+            ndp_send_ra(slirp);
+        }
+        break;
+
+    case ICMP6_NDP_RA:
+        DEBUG_CALL(" type = Router Advertisement");
+        qemu_log_mask(LOG_GUEST_ERROR,
+                "Warning: guest sent NDP RA, but shouldn't");
+        break;
+
+    case ICMP6_NDP_NS:
+        DEBUG_CALL(" type = Neighbor Solicitation");
+        if (ip->ip_hl == 255
+                && icmp->icmp6_code == 0
+                && !IN6_IS_ADDR_MULTICAST(&icmp->icmp6_nns.target)
+                && ntohs(ip->ip_pl) >= ICMP6_NDP_NS_MINLEN
+                && (!IN6_IS_ADDR_UNSPECIFIED(&ip->ip_src)
+                    || in6_solicitednode_multicast(&ip->ip_dst))) {
+            if (in6_equal_host(&icmp->icmp6_nns.target)) {
+                /* Gratuitous NDP */
+                ndp_table_add(slirp, ip->ip_src, eth->h_source);
+                ndp_send_na(slirp, ip, icmp);
+            }
+        }
+        break;
+
+    case ICMP6_NDP_NA:
+        DEBUG_CALL(" type = Neighbor Advertisement");
+        if (ip->ip_hl == 255
+                && icmp->icmp6_code == 0
+                && ntohs(ip->ip_pl) >= ICMP6_NDP_NA_MINLEN
+                && !IN6_IS_ADDR_MULTICAST(&icmp->icmp6_nna.target)
+                && (!IN6_IS_ADDR_MULTICAST(&ip->ip_dst)
+                    || icmp->icmp6_nna.S == 0)) {
+            ndp_table_add(slirp, ip->ip_src, eth->h_source);
+        }
+        break;
+
+    case ICMP6_NDP_REDIRECT:
+        DEBUG_CALL(" type = Redirect");
+        qemu_log_mask(LOG_GUEST_ERROR,
+                "Warning: guest sent NDP REDIRECT, but shouldn't");
+        break;
+    }
+}
+
+/*
+ * Process a received ICMPv6 message.
+ */
+void icmp6_input(struct mbuf *m)
+{
+    struct icmp6 *icmp;
+    struct ip6 *ip = mtod(m, struct ip6 *);
+    Slirp *slirp = m->slirp;
+    int hlen = sizeof(struct ip6);
+
+    DEBUG_CALL("icmp6_input");
+    DEBUG_ARG("m = %lx", (long) m);
+    DEBUG_ARG("m_len = %d", m->m_len);
+
+    if (ntohs(ip->ip_pl) < ICMP6_MINLEN) {
+        goto end;
+    }
+
+    if (ip6_cksum(m)) {
+        goto end;
+    }
+
+    m->m_len -= hlen;
+    m->m_data += hlen;
+    icmp = mtod(m, struct icmp6 *);
+    m->m_len += hlen;
+    m->m_data -= hlen;
+
+    DEBUG_ARG("icmp6_type = %d", icmp->icmp6_type);
+    switch (icmp->icmp6_type) {
+    case ICMP6_ECHO_REQUEST:
+        if (in6_equal_host(&ip->ip_dst)) {
+            icmp6_send_echoreply(m, slirp, ip, icmp);
+        } else {
+            /* TODO */
+            error_report("external icmpv6 not supported yet");
+        }
+        break;
+
+    case ICMP6_NDP_RS:
+    case ICMP6_NDP_RA:
+    case ICMP6_NDP_NS:
+    case ICMP6_NDP_NA:
+    case ICMP6_NDP_REDIRECT:
+        ndp_input(m, slirp, ip, icmp);
+        break;
+
+    case ICMP6_UNREACH:
+    case ICMP6_TOOBIG:
+    case ICMP6_TIMXCEED:
+    case ICMP6_PARAMPROB:
+        /* XXX? report error? close socket? */
+    default:
+        break;
+    }
+
+end:
+    m_free(m);
+}
diff --git a/slirp/ip6_icmp.h b/slirp/ip6_icmp.h
new file mode 100644
index 0000000000..b2c40d6c96
--- /dev/null
+++ b/slirp/ip6_icmp.h
@@ -0,0 +1,203 @@
+/*
+ * Copyright (c) 2013
+ * Guillaume Subiron, Yann Bordenave, Serigne Modou Wagne.
+ */
+
+#ifndef SLIRP_NETINET_ICMP6_H_
+#define SLIRP_NETINET_ICMP6_H_
+
+/*
+ * Interface Control Message Protocol version 6 Definitions.
+ * Per RFC 4443, March 2006.
+ *
+ * Network Discover Protocol Definitions.
+ * Per RFC 4861, September 2007.
+ */
+
+struct icmp6_echo { /* Echo Messages */
+    uint16_t id;
+    uint16_t seq_num;
+};
+
+/*
+ * NDP Messages
+ */
+struct ndp_rs {     /* Router Solicitation Message */
+    uint32_t reserved;
+};
+
+struct ndp_ra {     /* Router Advertisement Message */
+    uint8_t chl;    /* Cur Hop Limit */
+#ifdef HOST_WORDS_BIGENDIAN
+    uint8_t
+        M:1,
+        O:1,
+        reserved:6;
+#else
+    uint8_t
+        reserved:6,
+        O:1,
+        M:1;
+#endif
+    uint16_t lifetime;      /* Router Lifetime */
+    uint32_t reach_time;    /* Reachable Time */
+    uint32_t retrans_time;  /* Retrans Timer */
+} QEMU_PACKED;
+
+struct ndp_ns {     /* Neighbor Solicitation Message */
+    uint32_t reserved;
+    struct in6_addr target; /* Target Address */
+} QEMU_PACKED;
+
+struct ndp_na {     /* Neighbor Advertisement Message */
+#ifdef HOST_WORDS_BIGENDIAN
+    uint32_t
+        R:1,                /* Router Flag */
+        S:1,                /* Solicited Flag */
+        O:1,                /* Override Flag */
+        reserved_hi:5,
+        reserved_lo:24;
+#else
+    uint32_t
+        reserved_hi:5,
+        O:1,
+        S:1,
+        R:1,
+        reserved_lo:24;
+#endif
+    struct in6_addr target; /* Target Address */
+} QEMU_PACKED;
+
+struct ndp_redirect {
+    uint32_t reserved;
+    struct in6_addr target; /* Target Address */
+    struct in6_addr dest;   /* Destination Address */
+} QEMU_PACKED;
+
+/*
+ * Structure of an icmpv6 header.
+ */
+struct icmp6 {
+    uint8_t     icmp6_type;         /* type of message, see below */
+    uint8_t     icmp6_code;         /* type sub code */
+    uint16_t    icmp6_cksum;        /* ones complement cksum of struct */
+    union {
+        struct icmp6_echo echo;
+        struct ndp_rs ndp_rs;
+        struct ndp_ra ndp_ra;
+        struct ndp_ns ndp_ns;
+        struct ndp_na ndp_na;
+        struct ndp_redirect ndp_redirect;
+    } icmp6_body;
+#define icmp6_echo icmp6_body.echo
+#define icmp6_nrs icmp6_body.ndp_rs
+#define icmp6_nra icmp6_body.ndp_ra
+#define icmp6_nns icmp6_body.ndp_ns
+#define icmp6_nna icmp6_body.ndp_na
+#define icmp6_redirect icmp6_body.ndp_redirect
+} QEMU_PACKED;
+
+#define ICMP6_MINLEN    4
+#define ICMP6_ECHO_MINLEN   8
+#define ICMP6_NDP_RS_MINLEN 8
+#define ICMP6_NDP_RA_MINLEN 16
+#define ICMP6_NDP_NS_MINLEN 24
+#define ICMP6_NDP_NA_MINLEN 24
+#define ICMP6_NDP_REDIRECT_MINLEN 40
+
+/*
+ * NDP Options
+ */
+struct ndpopt {
+    uint8_t     ndpopt_type;                    /* Option type */
+    uint8_t     ndpopt_len;                     /* /!\ In units of 8 octets */
+    union {
+        unsigned char   linklayer_addr[6];      /* Source/Target Link-layer */
+        struct prefixinfo {                     /* Prefix Information */
+            uint8_t     prefix_length;
+#ifdef HOST_WORDS_BIGENDIAN
+            uint8_t     L:1, A:1, reserved1:6;
+#else
+            uint8_t     reserved1:6, A:1, L:1;
+#endif
+            uint32_t    valid_lt;               /* Valid Lifetime */
+            uint32_t    pref_lt;                /* Preferred Lifetime */
+            uint32_t    reserved2;
+            struct in6_addr prefix;
+        } QEMU_PACKED prefixinfo;
+    } ndpopt_body;
+#define ndpopt_linklayer ndpopt_body.linklayer_addr
+#define ndpopt_prefixinfo ndpopt_body.prefixinfo
+} QEMU_PACKED;
+
+/* NDP options type */
+#define NDPOPT_LINKLAYER_SOURCE     1   /* Source Link-Layer Address */
+#define NDPOPT_LINKLAYER_TARGET     2   /* Target Link-Layer Address */
+#define NDPOPT_PREFIX_INFO          3   /* Prefix Information */
+
+/* NDP options size, in octets. */
+#define NDPOPT_LINKLAYER_LEN    8
+#define NDPOPT_PREFIXINFO_LEN   32
+
+/*
+ * Definition of type and code field values.
+ * Per https://www.iana.org/assignments/icmpv6-parameters/icmpv6-parameters.xml
+ * Last Updated 2012-11-12
+ */
+
+/* Errors */
+#define ICMP6_UNREACH   1   /* Destination Unreachable */
+#define     ICMP6_UNREACH_NO_ROUTE      0   /* no route to dest */
+#define     ICMP6_UNREACH_DEST_PROHIB   1   /* com with dest prohibited */
+#define     ICMP6_UNREACH_SCOPE         2   /* beyond scope of src addr */
+#define     ICMP6_UNREACH_ADDRESS       3   /* address unreachable */
+#define     ICMP6_UNREACH_PORT          4   /* port unreachable */
+#define     ICMP6_UNREACH_SRC_FAIL      5   /* src addr failed */
+#define     ICMP6_UNREACH_REJECT_ROUTE  6   /* reject route to dest */
+#define     ICMP6_UNREACH_SRC_HDR_ERROR 7   /* error in src routing header */
+#define ICMP6_TOOBIG    2   /* Packet Too Big */
+#define ICMP6_TIMXCEED  3   /* Time Exceeded */
+#define     ICMP6_TIMXCEED_INTRANS      0   /* hop limit exceeded in transit */
+#define     ICMP6_TIMXCEED_REASS        1   /* ttl=0 in reass */
+#define ICMP6_PARAMPROB 4   /* Parameter Problem */
+#define     ICMP6_PARAMPROB_HDR_FIELD   0   /* err header field */
+#define     ICMP6_PARAMPROB_NXTHDR_TYPE 1   /* unrecognized Next Header type */
+#define     ICMP6_PARAMPROB_IPV6_OPT    2   /* unrecognized IPv6 option */
+
+/* Informational Messages */
+#define ICMP6_ECHO_REQUEST      128 /* Echo Request */
+#define ICMP6_ECHO_REPLY        129 /* Echo Reply */
+#define ICMP6_NDP_RS            133 /* Router Solicitation (NDP) */
+#define ICMP6_NDP_RA            134 /* Router Advertisement (NDP) */
+#define ICMP6_NDP_NS            135 /* Neighbor Solicitation (NDP) */
+#define ICMP6_NDP_NA            136 /* Neighbor Advertisement (NDP) */
+#define ICMP6_NDP_REDIRECT      137 /* Redirect Message (NDP) */
+
+/*
+ * Router Configuration Variables (rfc4861#section-6)
+ */
+#define NDP_IsRouter                1
+#define NDP_AdvSendAdvertisements   1
+#define NDP_MaxRtrAdvInterval       600000
+#define NDP_MinRtrAdvInterval       ((NDP_MaxRtrAdvInterval >= 9) ? \
+                                        NDP_MaxRtrAdvInterval / 3 : \
+                                        NDP_MaxRtrAdvInterval)
+#define NDP_AdvManagedFlag          0
+#define NDP_AdvOtherConfigFlag      0
+#define NDP_AdvLinkMTU              0
+#define NDP_AdvReachableTime        0
+#define NDP_AdvRetransTime          0
+#define NDP_AdvCurHopLimit          64
+#define NDP_AdvDefaultLifetime      ((3 * NDP_MaxRtrAdvInterval) / 1000)
+#define NDP_AdvValidLifetime        86400
+#define NDP_AdvOnLinkFlag           1
+#define NDP_AdvPrefLifetime         14400
+#define NDP_AdvAutonomousFlag       1
+
+void icmp6_init(Slirp *slirp);
+void icmp6_cleanup(Slirp *slirp);
+void icmp6_input(struct mbuf *);
+void ndp_send_ra(Slirp *slirp);
+void ndp_send_ns(Slirp *slirp, struct in6_addr addr);
+
+#endif
diff --git a/slirp/ip6_input.c b/slirp/ip6_input.c
new file mode 100644
index 0000000000..add9e6a73a
--- /dev/null
+++ b/slirp/ip6_input.c
@@ -0,0 +1,67 @@
+/*
+ * Copyright (c) 2013
+ * Guillaume Subiron, Yann Bordenave, Serigne Modou Wagne.
+ */
+
+#include "qemu/osdep.h"
+#include "slirp.h"
+#include "ip6_icmp.h"
+
+/*
+ * IP initialization: fill in IP protocol switch table.
+ * All protocols not implemented in kernel go to raw IP protocol handler.
+ */
+void ip6_init(Slirp *slirp)
+{
+    icmp6_init(slirp);
+}
+
+void ip6_cleanup(Slirp *slirp)
+{
+    icmp6_cleanup(slirp);
+}
+
+void ip6_input(struct mbuf *m)
+{
+    struct ip6 *ip6;
+
+    DEBUG_CALL("ip6_input");
+    DEBUG_ARG("m = %lx", (long)m);
+    DEBUG_ARG("m_len = %d", m->m_len);
+
+    if (m->m_len < sizeof(struct ip6)) {
+        goto bad;
+    }
+
+    ip6 = mtod(m, struct ip6 *);
+
+    if (ip6->ip_v != IP6VERSION) {
+        goto bad;
+    }
+
+    /* check ip_ttl for a correct ICMP reply */
+    if (ip6->ip_hl == 0) {
+        /*icmp_error(m, ICMP_TIMXCEED,ICMP_TIMXCEED_INTRANS, 0,"ttl");*/
+        goto bad;
+    }
+
+    /*
+     * Switch out to protocol's input routine.
+     */
+    switch (ip6->ip_nh) {
+    case IPPROTO_TCP:
+        /*tcp_input(m, hlen, (struct socket *)NULL);*/
+        break;
+    case IPPROTO_UDP:
+        /*udp_input(m, hlen);*/
+        break;
+    case IPPROTO_ICMPV6:
+        icmp6_input(m);
+        break;
+    default:
+        m_free(m);
+    }
+    return;
+bad:
+    m_free(m);
+}
diff --git a/slirp/ip6_output.c b/slirp/ip6_output.c
new file mode 100644
index 0000000000..762cbfe89c
--- /dev/null
+++ b/slirp/ip6_output.c
@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2013
+ * Guillaume Subiron, Yann Bordenave, Serigne Modou Wagne.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+#include "slirp.h"
+
+/* Number of packets queued before we start sending
+ * (to prevent allocing too many mbufs) */
+#define IF6_THRESH 10
+
+/*
+ * IPv6 output. The packet in mbuf chain m contains a IP header
+ */
+int ip6_output(struct socket *so, struct mbuf *m, int fast)
+{
+    struct ip6 *ip = mtod(m, struct ip6 *);
+
+    DEBUG_CALL("ip6_output");
+    DEBUG_ARG("so = %lx", (long)so);
+    DEBUG_ARG("m = %lx", (long)m);
+
+    /* Fill IPv6 header */
+    ip->ip_v = IP6VERSION;
+    ip->ip_hl = IP6_HOP_LIMIT;
+    ip->ip_tc_hi = 0;
+    ip->ip_tc_lo = 0;
+    ip->ip_fl_hi = 0;
+    ip->ip_fl_lo = 0;
+
+    if (fast) {
+        if_encap(m->slirp, m);
+    } else {
+        if_output(so, m);
+    }
+
+    return 0;
+}
diff --git a/slirp/ndp_table.c b/slirp/ndp_table.c
new file mode 100644
index 0000000000..9d4c39b45c
--- /dev/null
+++ b/slirp/ndp_table.c
@@ -0,0 +1,90 @@
+/*
+ * Copyright (c) 2013
+ * Guillaume Subiron, Yann Bordenave, Serigne Modou Wagne.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+#include "slirp.h"
+
+void ndp_table_add(Slirp *slirp, struct in6_addr ip_addr,
+                    uint8_t ethaddr[ETH_ALEN])
+{
+    NdpTable *ndp_table = &slirp->ndp_table;
+    int i;
+
+    DEBUG_CALL("ndp_table_add");
+#if !defined(_WIN32) || (_WIN32_WINNT >= 0x0600)
+    char addrstr[INET6_ADDRSTRLEN];
+    inet_ntop(AF_INET6, &(ip_addr), addrstr, INET6_ADDRSTRLEN);
+    DEBUG_ARG("ip = %s", addrstr);
+#endif
+    DEBUG_ARGS((dfd, " hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n",
+                ethaddr[0], ethaddr[1], ethaddr[2],
+                ethaddr[3], ethaddr[4], ethaddr[5]));
+
+    if (IN6_IS_ADDR_MULTICAST(&ip_addr) || IN6_IS_ADDR_UNSPECIFIED(&ip_addr)) {
+        /* Do not register multicast or unspecified addresses */
+        DEBUG_CALL(" abort: do not register multicast or unspecified address");
+        return;
+    }
+
+    /* Search for an entry */
+    for (i = 0; i < NDP_TABLE_SIZE; i++) {
+        if (in6_equal(&ndp_table->table[i].ip_addr, &ip_addr)) {
+            DEBUG_CALL(" already in table: update the entry");
+            /* Update the entry */
+            memcpy(ndp_table->table[i].eth_addr, ethaddr, ETH_ALEN);
+            return;
+        }
+    }
+
+    /* No entry found, create a new one */
+    DEBUG_CALL(" create new entry");
+    ndp_table->table[ndp_table->next_victim].ip_addr = ip_addr;
+    memcpy(ndp_table->table[ndp_table->next_victim].eth_addr,
+            ethaddr, ETH_ALEN);
+    ndp_table->next_victim = (ndp_table->next_victim + 1) % NDP_TABLE_SIZE;
+}
+
+bool ndp_table_search(Slirp *slirp, struct in6_addr ip_addr,
+                      uint8_t out_ethaddr[ETH_ALEN])
+{
+    NdpTable *ndp_table = &slirp->ndp_table;
+    int i;
+
+    DEBUG_CALL("ndp_table_search");
+#if !defined(_WIN32) || (_WIN32_WINNT >= 0x0600)
+    char addrstr[INET6_ADDRSTRLEN];
+    inet_ntop(AF_INET6, &(ip_addr), addrstr, INET6_ADDRSTRLEN);
+    DEBUG_ARG("ip = %s", addrstr);
+#endif
+
+    assert(!IN6_IS_ADDR_UNSPECIFIED(&ip_addr));
+
+    /* Multicast address: fec0::abcd:efgh/8 -> 33:33:ab:cd:ef:gh */
+    if (IN6_IS_ADDR_MULTICAST(&ip_addr)) {
+        out_ethaddr[0] = 0x33; out_ethaddr[1] = 0x33;
+        out_ethaddr[2] = ip_addr.s6_addr[12];
+        out_ethaddr[3] = ip_addr.s6_addr[13];
+        out_ethaddr[4] = ip_addr.s6_addr[14];
+        out_ethaddr[5] = ip_addr.s6_addr[15];
+        DEBUG_ARGS((dfd, " multicast addr = %02x:%02x:%02x:%02x:%02x:%02x\n",
+                    out_ethaddr[0], out_ethaddr[1], out_ethaddr[2],
+                    out_ethaddr[3], out_ethaddr[4], out_ethaddr[5]));
+        return 1;
+    }
+
+    for (i = 0; i < NDP_TABLE_SIZE; i++) {
+        if (in6_equal(&ndp_table->table[i].ip_addr, &ip_addr)) {
+            memcpy(out_ethaddr, ndp_table->table[i].eth_addr,  ETH_ALEN);
+            DEBUG_ARGS((dfd, " found hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n",
+                        out_ethaddr[0], out_ethaddr[1], out_ethaddr[2],
+                        out_ethaddr[3], out_ethaddr[4], out_ethaddr[5]));
+            return 1;
+        }
+    }
+
+    DEBUG_CALL(" ip not found in table");
+    return 0;
+}
diff --git a/slirp/slirp.c b/slirp/slirp.c
index 0466d330da..049c2cfb1e 100644
--- a/slirp/slirp.c
+++ b/slirp/slirp.c
@@ -210,10 +210,12 @@ Slirp *slirp_init(int restricted, struct in_addr vnetwork,
 
     slirp_init_once();
 
+    slirp->grand = g_rand_new();
     slirp->restricted = restricted;
 
     if_init(slirp);
     ip_init(slirp);
+    ip6_init(slirp);
 
     /* Initialise mbufs *after* setting the MTU */
     m_init(slirp);
@@ -221,6 +223,19 @@ Slirp *slirp_init(int restricted, struct in_addr vnetwork,
     slirp->vnetwork_addr = vnetwork;
     slirp->vnetwork_mask = vnetmask;
     slirp->vhost_addr = vhost;
+#if defined(_WIN32) && (_WIN32_WINNT < 0x0600)
+    /* No inet_pton helper... */
+    memset(&slirp->vprefix_addr6, 0, sizeof(slirp->vprefix_addr6));
+    slirp->vprefix_addr6.s6_addr[0] = 0xfe;
+    slirp->vprefix_addr6.s6_addr[1] = 0xc0;
+    slirp->vprefix_len = 64;
+    slirp->vhost_addr6 = slirp->vprefix_addr6;
+    slirp->vhost_addr6.s6_addr[15] = 0x2;
+#else
+    inet_pton(AF_INET6, "fec0::0", &slirp->vprefix_addr6);
+    slirp->vprefix_len = 64;
+    inet_pton(AF_INET6, "fec0::2", &slirp->vhost_addr6);
+#endif
     if (vhostname) {
         pstrcpy(slirp->client_hostname, sizeof(slirp->client_hostname),
                 vhostname);
@@ -251,8 +266,11 @@ void slirp_cleanup(Slirp *slirp)
     unregister_savevm(NULL, "slirp", slirp);
 
     ip_cleanup(slirp);
+    ip6_cleanup(slirp);
     m_cleanup(slirp);
 
+    g_rand_free(slirp->grand);
+
     g_free(slirp->vdnssearch);
     g_free(slirp->tftp_prefix);
     g_free(slirp->bootp_filename);
@@ -744,6 +762,7 @@ void slirp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
         arp_input(slirp, pkt, pkt_len);
         break;
     case ETH_P_IP:
+    case ETH_P_IPV6:
         m = m_get(slirp);
         if (!m)
             return;
@@ -757,8 +776,13 @@ void slirp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
         m->m_data += 2 + ETH_HLEN;
         m->m_len -= 2 + ETH_HLEN;
 
-        ip_input(m);
+        if (proto == ETH_P_IP) {
+            ip_input(m);
+        } else if (proto == ETH_P_IPV6) {
+            ip6_input(m);
+        }
         break;
+
     default:
         break;
     }
@@ -826,6 +850,31 @@ static int if_encap4(Slirp *slirp, struct mbuf *ifm, struct ethhdr *eh,
     }
 }
 
+/* Prepare the IPv6 packet to be sent to the ethernet device. Returns 1 if no
+ * packet should be sent, 0 if the packet must be re-queued, 2 if the packet
+ * is ready to go.
+ */
+static int if_encap6(Slirp *slirp, struct mbuf *ifm, struct ethhdr *eh,
+        uint8_t ethaddr[ETH_ALEN])
+{
+    const struct ip6 *ip6h = mtod(ifm, const struct ip6 *);
+    if (!ndp_table_search(slirp, ip6h->ip_dst, ethaddr)) {
+        if (!ifm->resolution_requested) {
+            ndp_send_ns(slirp, ip6h->ip_dst);
+            ifm->resolution_requested = true;
+            ifm->expiration_date =
+                qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + 1000000000ULL;
+        }
+        return 0;
+    } else {
+        eh->h_proto = htons(ETH_P_IPV6);
+        in6_compute_ethaddr(ip6h->ip_src, eh->h_source);
+
+        /* Send this */
+        return 2;
+    }
+}
+
 /* Output the IP packet to the ethernet device. Returns 0 if the packet must be
  * re-queued.
  */
@@ -849,9 +898,15 @@ int if_encap(Slirp *slirp, struct mbuf *ifm)
         }
         break;
 
+    case IP6VERSION:
+        ret = if_encap6(slirp, ifm, eh, ethaddr);
+        if (ret < 2) {
+            return ret;
+        }
+        break;
+
     default:
-        /* Do not assert while we don't manage IP6VERSION */
-        /* assert(0); */
+        g_assert_not_reached();
         break;
     }
 
diff --git a/slirp/slirp.h b/slirp/slirp.h
index a6741e77b1..393a9ca6ff 100644
--- a/slirp/slirp.h
+++ b/slirp/slirp.h
@@ -111,6 +111,8 @@ void free(void *ptr);
 #include <sys/stropts.h>
 #endif
 
+#include <glib.h>
+
 #include "debug.h"
 
 #include "qemu/queue.h"
@@ -119,12 +121,14 @@ void free(void *ptr);
 
 #include "libslirp.h"
 #include "ip.h"
+#include "ip6.h"
 #include "tcp.h"
 #include "tcp_timer.h"
 #include "tcp_var.h"
 #include "tcpip.h"
 #include "udp.h"
 #include "ip_icmp.h"
+#include "ip6_icmp.h"
 #include "mbuf.h"
 #include "sbuf.h"
 #include "socket.h"
@@ -176,6 +180,23 @@ void arp_table_add(Slirp *slirp, uint32_t ip_addr, uint8_t ethaddr[ETH_ALEN]);
 bool arp_table_search(Slirp *slirp, uint32_t ip_addr,
                       uint8_t out_ethaddr[ETH_ALEN]);
 
+struct ndpentry {
+    unsigned char   eth_addr[ETH_ALEN];     /* sender hardware address */
+    struct in6_addr ip_addr;                /* sender IP address       */
+} QEMU_PACKED;
+
+#define NDP_TABLE_SIZE 16
+
+typedef struct NdpTable {
+    struct ndpentry table[NDP_TABLE_SIZE];
+    int next_victim;
+} NdpTable;
+
+void ndp_table_add(Slirp *slirp, struct in6_addr ip_addr,
+                   uint8_t ethaddr[ETH_ALEN]);
+bool ndp_table_search(Slirp *slirp, struct in6_addr ip_addr,
+                      uint8_t out_ethaddr[ETH_ALEN]);
+
 struct Slirp {
     QTAILQ_ENTRY(Slirp) entry;
     u_int time_fasttimo;
@@ -186,6 +207,9 @@ struct Slirp {
     struct in_addr vnetwork_addr;
     struct in_addr vnetwork_mask;
     struct in_addr vhost_addr;
+    struct in6_addr vprefix_addr6;
+    uint8_t vprefix_len;
+    struct in6_addr vhost_addr6;
     struct in_addr vdhcp_startaddr;
     struct in_addr vnameserver_addr;
 
@@ -234,6 +258,10 @@ struct Slirp {
     struct tftp_session tftp_sessions[TFTP_SESSIONS_MAX];
 
     ArpTable arp_table;
+    NdpTable ndp_table;
+
+    GRand *grand;
+    QEMUTimer *ra_timer;
 
     void *opaque;
 };
@@ -276,6 +304,7 @@ int translate_dnssearch(Slirp *s, const char ** names);
 
 /* cksum.c */
 int cksum(struct mbuf *m, int len);
+int ip6_cksum(struct mbuf *m);
 
 /* if.c */
 void if_init(Slirp *);
@@ -291,6 +320,14 @@ void ip_stripoptions(register struct mbuf *, struct mbuf *);
 /* ip_output.c */
 int ip_output(struct socket *, struct mbuf *);
 
+/* ip6_input.c */
+void ip6_init(Slirp *);
+void ip6_cleanup(Slirp *);
+void ip6_input(struct mbuf *);
+
+/* ip6_output */
+int ip6_output(struct socket *, struct mbuf *, int fast);
+
 /* tcp_input.c */
 void tcp_input(register struct mbuf *, int, struct socket *);
 int tcp_mss(register struct tcpcb *, u_int);
diff --git a/slirp/socket.h b/slirp/socket.h
index c4afc9494f..bcebce110d 100644
--- a/slirp/socket.h
+++ b/slirp/socket.h
@@ -102,6 +102,13 @@ static inline int sockaddr_equal(struct sockaddr_storage *a,
         return a4->sin_addr.s_addr == b4->sin_addr.s_addr
                && a4->sin_port == b4->sin_port;
     }
+    case AF_INET6:
+    {
+        struct sockaddr_in6 *a6 = (struct sockaddr_in6 *) a;
+        struct sockaddr_in6 *b6 = (struct sockaddr_in6 *) b;
+        return (in6_equal(&a6->sin6_addr, &b6->sin6_addr)
+                && a6->sin6_port == b6->sin6_port);
+    }
     default:
         g_assert_not_reached();
     }