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/* SPDX-License-Identifier: BSD-3-Clause */
/*
* Copyright (c) 2013
* Guillaume Subiron, Yann Bordenave, Serigne Modou Wagne.
*/
#include "slirp.h"
#include "ip6_icmp.h"
#define NDP_Interval \
g_rand_int_range(slirp->grand, NDP_MinRtrAdvInterval, NDP_MaxRtrAdvInterval)
void icmp6_post_init(Slirp *slirp)
{
if (!slirp->in6_enabled) {
return;
}
slirp->ra_timer =
slirp_timer_new(slirp, SLIRP_TIMER_RA, NULL);
slirp->cb->timer_mod(slirp->ra_timer,
slirp->cb->clock_get_ns(slirp->opaque) / SCALE_MS +
NDP_Interval,
slirp->opaque);
}
void icmp6_cleanup(Slirp *slirp)
{
if (!slirp->in6_enabled) {
return;
}
slirp->cb->timer_free(slirp->ra_timer, slirp->opaque);
}
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);
}
void icmp6_forward_error(struct mbuf *m, uint8_t type, uint8_t code, struct in6_addr *src)
{
Slirp *slirp = m->slirp;
struct mbuf *t;
struct ip6 *ip = mtod(m, struct ip6 *);
char addrstr[INET6_ADDRSTRLEN];
DEBUG_CALL("icmp6_send_error");
DEBUG_ARG("type = %d, code = %d", type, code);
if (IN6_IS_ADDR_MULTICAST(&ip->ip_src) || in6_zero(&ip->ip_src)) {
/* TODO icmp error? */
return;
}
t = m_get(slirp);
/* IPv6 packet */
struct ip6 *rip = mtod(t, struct ip6 *);
rip->ip_src = *src;
rip->ip_dst = ip->ip_src;
inet_ntop(AF_INET6, &rip->ip_dst, addrstr, INET6_ADDRSTRLEN);
DEBUG_ARG("target = %s", addrstr);
rip->ip_nh = IPPROTO_ICMPV6;
const int error_data_len = MIN(
m->m_len, slirp->if_mtu - (sizeof(struct ip6) + ICMP6_ERROR_MINLEN));
rip->ip_pl = htons(ICMP6_ERROR_MINLEN + error_data_len);
t->m_len = sizeof(struct ip6) + ntohs(rip->ip_pl);
/* ICMPv6 packet */
t->m_data += sizeof(struct ip6);
struct icmp6 *ricmp = mtod(t, struct icmp6 *);
ricmp->icmp6_type = type;
ricmp->icmp6_code = code;
ricmp->icmp6_cksum = 0;
switch (type) {
case ICMP6_UNREACH:
case ICMP6_TIMXCEED:
ricmp->icmp6_err.unused = 0;
break;
case ICMP6_TOOBIG:
ricmp->icmp6_err.mtu = htonl(slirp->if_mtu);
break;
case ICMP6_PARAMPROB:
/* TODO: Handle this case */
break;
default:
g_assert_not_reached();
}
t->m_data += ICMP6_ERROR_MINLEN;
memcpy(t->m_data, m->m_data, error_data_len);
/* Checksum */
t->m_data -= ICMP6_ERROR_MINLEN;
t->m_data -= sizeof(struct ip6);
ricmp->icmp6_cksum = ip6_cksum(t);
ip6_output(NULL, t, 0);
}
void icmp6_send_error(struct mbuf *m, uint8_t type, uint8_t code)
{
struct in6_addr src = LINKLOCAL_ADDR;
icmp6_forward_error(m, type, code, &src);
}
/*
* Send NDP Router Advertisement
*/
static 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 *);
size_t pl_size = 0;
struct in6_addr addr;
uint32_t scope_id;
rip->ip_src = (struct in6_addr)LINKLOCAL_ADDR;
rip->ip_dst = (struct in6_addr)ALLNODES_MULTICAST;
rip->ip_nh = IPPROTO_ICMPV6;
/* 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);
t->m_data += ICMP6_NDP_RA_MINLEN;
pl_size += ICMP6_NDP_RA_MINLEN;
/* Source link-layer address (NDP option) */
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);
t->m_data += NDPOPT_LINKLAYER_LEN;
pl_size += NDPOPT_LINKLAYER_LEN;
/* Prefix information (NDP option) */
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;
t->m_data += NDPOPT_PREFIXINFO_LEN;
pl_size += NDPOPT_PREFIXINFO_LEN;
/* Prefix information (NDP option) */
if (get_dns6_addr(&addr, &scope_id) >= 0) {
/* Host system does have an IPv6 DNS server, announce our proxy. */
struct ndpopt *opt3 = mtod(t, struct ndpopt *);
opt3->ndpopt_type = NDPOPT_RDNSS;
opt3->ndpopt_len = NDPOPT_RDNSS_LEN / 8;
opt3->ndpopt_rdnss.reserved = 0;
opt3->ndpopt_rdnss.lifetime = htonl(2 * NDP_MaxRtrAdvInterval);
opt3->ndpopt_rdnss.addr = slirp->vnameserver_addr6;
t->m_data += NDPOPT_RDNSS_LEN;
pl_size += NDPOPT_RDNSS_LEN;
}
rip->ip_pl = htons(pl_size);
t->m_data -= sizeof(struct ip6) + pl_size;
t->m_len = sizeof(struct ip6) + pl_size;
/* ICMPv6 Checksum */
ricmp->icmp6_cksum = ip6_cksum(t);
ip6_output(NULL, t, 0);
}
void ra_timer_handler(Slirp *slirp, void *unused)
{
slirp->cb->timer_mod(slirp->ra_timer,
slirp->cb->clock_get_ns(slirp->opaque) / SCALE_MS +
NDP_Interval,
slirp->opaque);
ndp_send_ra(slirp);
}
/*
* Send NDP Neighbor Solitication
*/
void ndp_send_ns(Slirp *slirp, struct in6_addr addr)
{
char addrstr[INET6_ADDRSTRLEN];
inet_ntop(AF_INET6, &addr, addrstr, INET6_ADDRSTRLEN);
DEBUG_CALL("ndp_send_ns");
DEBUG_ARG("target = %s", addrstr);
/* 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_zero(&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)
{
g_assert(M_ROOMBEFORE(m) >= ETH_HLEN);
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");
slirp->cb->guest_error("Warning: guest sent NDP RA, but shouldn't",
slirp->opaque);
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_zero(&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");
slirp->cb->guest_error(
"Warning: guest sent NDP REDIRECT, but shouldn't", slirp->opaque);
break;
}
}
/*
* Process a received ICMPv6 message.
*/
void icmp6_input(struct mbuf *m)
{
Slirp *slirp = m->slirp;
/* NDP reads the ethernet header for gratuitous NDP */
M_DUP_DEBUG(slirp, m, 1, ETH_HLEN);
struct icmp6 *icmp;
struct ip6 *ip = mtod(m, struct ip6 *);
int hlen = sizeof(struct ip6);
DEBUG_CALL("icmp6_input");
DEBUG_ARG("m = %p", 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 */
g_critical("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);
}