bool ng_ipv6_ext_demux(kernel_pid_t iface, ng_pktsnip_t *pkt,
uint8_t nh)
{
ng_pktsnip_t *ext_snip;
ng_ipv6_ext_t *ext;
unsigned int offset = 0;
ext = ((ng_ipv6_ext_t *)(((uint8_t *)pkt->data) + sizeof(ng_ipv6_hdr_t)));
bool c = true;
while (c) {
switch (nh) {
case PROTNUM_IPV6_EXT_HOPOPT:
case PROTNUM_IPV6_EXT_DST:
case PROTNUM_IPV6_EXT_RH:
case PROTNUM_IPV6_EXT_FRAG:
case PROTNUM_IPV6_EXT_AH:
case PROTNUM_IPV6_EXT_ESP:
case PROTNUM_IPV6_EXT_MOB:
/* TODO: add handling of types */
nh = ext->nh;
offset += ((ext->len * NG_IPV6_EXT_LEN_UNIT) + NG_IPV6_EXT_LEN_UNIT);
ext = ng_ipv6_ext_get_next((ng_ipv6_ext_t *)ext);
break;
default:
c = false;
offset += ((ext->len * NG_IPV6_EXT_LEN_UNIT) + NG_IPV6_EXT_LEN_UNIT);
ext = ng_ipv6_ext_get_next((ng_ipv6_ext_t *)ext);
break;
}
}
ext_snip = ng_pktbuf_mark(pkt, offset, NG_NETTYPE_IPV6);
if (ext_snip == NULL) {
return false;
}
ng_ipv6_demux(iface, pkt, nh); /* demultiplex next header */
return true;
}
static void _receive(ng_pktsnip_t *pkt)
{
kernel_pid_t iface = KERNEL_PID_UNDEF;
ng_pktsnip_t *ipv6, *netif;
ng_ipv6_hdr_t *hdr;
LL_SEARCH_SCALAR(pkt, netif, type, NG_NETTYPE_NETIF);
if (netif != NULL) {
iface = ((ng_netif_hdr_t *)netif->data)->if_pid;
}
if ((pkt->next != NULL) && (pkt->next->type == NG_NETTYPE_IPV6) &&
(pkt->next->size == sizeof(ng_ipv6_hdr_t))) {
/* IP header was already marked. Take it. */
ipv6 = pkt->next;
if (!ng_ipv6_hdr_is(ipv6->data)) {
DEBUG("ipv6: Received packet was not IPv6, dropping packet\n");
ng_pktbuf_release(pkt);
return;
}
}
else {
if (!ng_ipv6_hdr_is(pkt->data)) {
DEBUG("ipv6: Received packet was not IPv6, dropping packet\n");
ng_pktbuf_release(pkt);
return;
}
/* seize ipv6 as a temporary variable */
ipv6 = ng_pktbuf_start_write(pkt);
if (ipv6 == NULL) {
DEBUG("ipv6: unable to get write access to packet, drop it\n");
ng_pktbuf_release(pkt);
return;
}
pkt = ipv6; /* reset pkt from temporary variable */
ipv6 = ng_pktbuf_add(pkt, pkt->data, sizeof(ng_ipv6_hdr_t),
NG_NETTYPE_IPV6);
if (ipv6 == NULL) {
DEBUG("ipv6: error marking IPv6 header, dropping packet\n");
ng_pktbuf_release(pkt);
return;
}
}
/* extract header */
hdr = (ng_ipv6_hdr_t *)ipv6->data;
DEBUG("ipv6: Received (src = %s, ",
ng_ipv6_addr_to_str(addr_str, &(hdr->src), sizeof(addr_str)));
DEBUG("dst = %s, next header = %" PRIu8 ", length = %" PRIu16 ")\n",
ng_ipv6_addr_to_str(addr_str, &(hdr->dst), sizeof(addr_str)),
hdr->nh, byteorder_ntohs(hdr->len));
if (_pkt_not_for_me(&iface, hdr)) { /* if packet is not for me */
DEBUG("ipv6: packet destination not this host\n");
#ifdef MODULE_NG_IPV6_ROUTER /* only routers redirect */
/* redirect to next hop */
DEBUG("ipv6: decrement hop limit to %" PRIu8 "\n", hdr->hl - 1);
/* TODO: check if receiving interface is router */
if (--(hdr->hl) > 0) { /* drop packets that *reach* Hop Limit 0 */
ng_pktsnip_t *tmp = pkt;
DEBUG("ipv6: forward packet to next hop\n");
/* pkt might not be writable yet, if header was given above */
pkt = ng_pktbuf_start_write(tmp);
ipv6 = ng_pktbuf_start_write(ipv6);
if ((ipv6 == NULL) || (pkt == NULL)) {
DEBUG("ipv6: unable to get write access to packet: dropping it\n");
ng_pktbuf_release(tmp);
return;
}
ng_pktbuf_release(ipv6->next); /* remove headers around IPV6 */
ipv6->next = pkt; /* reorder for sending */
pkt->next = NULL;
_send(ipv6, false);
}
else {
DEBUG("ipv6: hop limit reached 0: drop packet\n");
ng_pktbuf_release(pkt);
return;
}
#else /* MODULE_NG_IPV6_ROUTER */
DEBUG("ipv6: dropping packet\n");
/* non rounting hosts just drop the packet */
ng_pktbuf_release(pkt);
return;
#endif /* MODULE_NG_IPV6_ROUTER */
}
/* IPv6 internal demuxing (ICMPv6, Extension headers etc.) */
ng_ipv6_demux(iface, pkt, hdr->nh);
}
