/**
* Forwards an IPv6 packet. It finds an appropriate route for the
* packet, decrements the HL value of the packet, and outputs
* the packet on the appropriate interface.
*
* @param p the packet to forward (p->payload points to IP header)
* @param iphdr the IPv6 header of the input packet
* @param inp the netif on which this packet was received
*/
static void
ip6_forward(struct pbuf *p, struct ip6_hdr *iphdr, struct netif *inp)
{
struct netif *netif;
/* do not forward link-local addresses */
if (ip6_addr_islinklocal(ip6_current_dest_addr())) {
LWIP_DEBUGF(IP6_DEBUG, ("ip6_forward: not forwarding link-local address.\n"));
IP6_STATS_INC(ip6.rterr);
IP6_STATS_INC(ip6.drop);
return;
}
/* Find network interface where to forward this IP packet to. */
netif = ip6_route(IP6_ADDR_ANY6, ip6_current_dest_addr());
if (netif == NULL) {
LWIP_DEBUGF(IP6_DEBUG, ("ip6_forward: no route for %"X16_F":%"X16_F":%"X16_F":%"X16_F":%"X16_F":%"X16_F":%"X16_F":%"X16_F"\n",
IP6_ADDR_BLOCK1(ip6_current_dest_addr()),
IP6_ADDR_BLOCK2(ip6_current_dest_addr()),
IP6_ADDR_BLOCK3(ip6_current_dest_addr()),
IP6_ADDR_BLOCK4(ip6_current_dest_addr()),
IP6_ADDR_BLOCK5(ip6_current_dest_addr()),
IP6_ADDR_BLOCK6(ip6_current_dest_addr()),
IP6_ADDR_BLOCK7(ip6_current_dest_addr()),
IP6_ADDR_BLOCK8(ip6_current_dest_addr())));
#if LWIP_ICMP6
/* Don't send ICMP messages in response to ICMP messages */
if (IP6H_NEXTH(iphdr) != IP6_NEXTH_ICMP6) {
icmp6_dest_unreach(p, ICMP6_DUR_NO_ROUTE);
}
#endif /* LWIP_ICMP6 */
IP6_STATS_INC(ip6.rterr);
IP6_STATS_INC(ip6.drop);
return;
}
/* Do not forward packets onto the same network interface on which
* they arrived. */
if (netif == inp) {
LWIP_DEBUGF(IP6_DEBUG, ("ip6_forward: not bouncing packets back on incoming interface.\n"));
IP6_STATS_INC(ip6.rterr);
IP6_STATS_INC(ip6.drop);
return;
}
/* decrement HL */
IP6H_HOPLIM_SET(iphdr, IP6H_HOPLIM(iphdr) - 1);
/* send ICMP6 if HL == 0 */
if (IP6H_HOPLIM(iphdr) == 0) {
#if LWIP_ICMP6
/* Don't send ICMP messages in response to ICMP messages */
if (IP6H_NEXTH(iphdr) != IP6_NEXTH_ICMP6) {
icmp6_time_exceeded(p, ICMP6_TE_HL);
}
#endif /* LWIP_ICMP6 */
IP6_STATS_INC(ip6.drop);
return;
}
if (netif->mtu && (p->tot_len > netif->mtu)) {
#if LWIP_ICMP6
/* Don't send ICMP messages in response to ICMP messages */
if (IP6H_NEXTH(iphdr) != IP6_NEXTH_ICMP6) {
icmp6_packet_too_big(p, netif->mtu);
}
#endif /* LWIP_ICMP6 */
IP6_STATS_INC(ip6.drop);
return;
}
LWIP_DEBUGF(IP6_DEBUG, ("ip6_forward: forwarding packet to %"X16_F":%"X16_F":%"X16_F":%"X16_F":%"X16_F":%"X16_F":%"X16_F":%"X16_F"\n",
IP6_ADDR_BLOCK1(ip6_current_dest_addr()),
IP6_ADDR_BLOCK2(ip6_current_dest_addr()),
IP6_ADDR_BLOCK3(ip6_current_dest_addr()),
IP6_ADDR_BLOCK4(ip6_current_dest_addr()),
IP6_ADDR_BLOCK5(ip6_current_dest_addr()),
IP6_ADDR_BLOCK6(ip6_current_dest_addr()),
IP6_ADDR_BLOCK7(ip6_current_dest_addr()),
IP6_ADDR_BLOCK8(ip6_current_dest_addr())));
/* transmit pbuf on chosen interface */
netif->output_ip6(netif, p, ip6_current_dest_addr());
IP6_STATS_INC(ip6.fw);
IP6_STATS_INC(ip6.xmit);
return;
}
/**
* Forwards an IPv6 packet. It finds an appropriate route for the
* packet, decrements the HL value of the packet, and outputs
* the packet on the appropriate interface.
*
* @param p the packet to forward (p->payload points to IP header)
* @param iphdr the IPv6 header of the input packet
* @param inp the netif on which this packet was received
* @return -1 if packet is to be dropped, 0 if there's no route, 1 if forwarded
*/
static int
ip6_forward(struct pbuf *p, struct ip6_hdr *iphdr, struct netif *inp)
{
enum { FWD_DROP = -1, FWD_PROXY = 0, FWD_FORWARDED = 1 };
struct netif *netif;
/* do not forward link-local addresses */
if (ip6_addr_islinklocal(ip6_current_dest_addr())) {
LWIP_DEBUGF(IP6_DEBUG, ("ip6_forward: not forwarding link-local address.\n"));
IP6_STATS_INC(ip6.rterr);
IP6_STATS_INC(ip6.drop);
return FWD_DROP;
}
/* Find network interface where to forward this IP packet to. */
netif = ip6_route_fwd(ip6_current_dest_addr());
if (netif == NULL) {
LWIP_DEBUGF(IP6_DEBUG, ("ip6_forward: no route for %"X16_F":%"X16_F":%"X16_F":%"X16_F":%"X16_F":%"X16_F":%"X16_F":%"X16_F"\n",
IP6_ADDR_BLOCK1(ip6_current_dest_addr()),
IP6_ADDR_BLOCK2(ip6_current_dest_addr()),
IP6_ADDR_BLOCK3(ip6_current_dest_addr()),
IP6_ADDR_BLOCK4(ip6_current_dest_addr()),
IP6_ADDR_BLOCK5(ip6_current_dest_addr()),
IP6_ADDR_BLOCK6(ip6_current_dest_addr()),
IP6_ADDR_BLOCK7(ip6_current_dest_addr()),
IP6_ADDR_BLOCK8(ip6_current_dest_addr())));
#if LWIP_CONNECTION_PROXY
return FWD_PROXY;
#else /* !LWIP_CONNECTION_PROXY */
#if LWIP_ICMP6
/* Don't send ICMP messages in response to ICMP messages */
if (IP6H_NEXTH(iphdr) != IP6_NEXTH_ICMP6) {
icmp6_dest_unreach(p, ICMP6_DUR_NO_ROUTE);
}
#endif /* LWIP_ICMP6 */
IP6_STATS_INC(ip6.rterr);
IP6_STATS_INC(ip6.drop);
return FWD_DROP;
#endif /* !LWIP_CONNECTION_PROXY */
}
#if LWIP_CONNECTION_PROXY
/* The packet is for a destination on a directly connected network.
* Check for addresses in that address space that proxy wants to
* remap (e.g. to host loopback address/es) and hand it off to
* proxy */
if (netif != netif_default
&& proxy_ip6_divert_hook != NULL
&& (*proxy_ip6_divert_hook)(netif, ip6_current_dest_addr()))
{
return FWD_PROXY;
}
#endif /* LWIP_CONNECTION_PROXY */
/* Do not forward packets onto the same network interface on which
* they arrived. */
if (netif == inp) {
LWIP_DEBUGF(IP6_DEBUG, ("ip6_forward: not bouncing packets back on incoming interface.\n"));
IP6_STATS_INC(ip6.rterr);
IP6_STATS_INC(ip6.drop);
return FWD_DROP;
}
/* decrement HL */
IP6H_HOPLIM_SET(iphdr, IP6H_HOPLIM(iphdr) - 1);
/* send ICMP6 if HL == 0 */
if (IP6H_HOPLIM(iphdr) == 0) {
#if LWIP_ICMP6
/* Don't send ICMP messages in response to ICMP messages */
if (IP6H_NEXTH(iphdr) != IP6_NEXTH_ICMP6) {
icmp6_time_exceeded(p, ICMP6_TE_HL);
}
#endif /* LWIP_ICMP6 */
IP6_STATS_INC(ip6.drop);
return FWD_DROP;
}
if (netif->mtu && (p->tot_len > netif->mtu)) {
#if LWIP_ICMP6
/* Don't send ICMP messages in response to ICMP messages */
if (IP6H_NEXTH(iphdr) != IP6_NEXTH_ICMP6) {
icmp6_packet_too_big(p, netif->mtu);
}
#endif /* LWIP_ICMP6 */
IP6_STATS_INC(ip6.drop);
return FWD_DROP;
}
LWIP_DEBUGF(IP6_DEBUG, ("ip6_forward: forwarding packet to %"X16_F":%"X16_F":%"X16_F":%"X16_F":%"X16_F":%"X16_F":%"X16_F":%"X16_F"\n",
IP6_ADDR_BLOCK1(ip6_current_dest_addr()),
IP6_ADDR_BLOCK2(ip6_current_dest_addr()),
IP6_ADDR_BLOCK3(ip6_current_dest_addr()),
IP6_ADDR_BLOCK4(ip6_current_dest_addr()),
IP6_ADDR_BLOCK5(ip6_current_dest_addr()),
IP6_ADDR_BLOCK6(ip6_current_dest_addr()),
IP6_ADDR_BLOCK7(ip6_current_dest_addr()),
IP6_ADDR_BLOCK8(ip6_current_dest_addr())));
/* transmit pbuf on chosen interface */
netif->output_ip6(netif, p, ip6_current_dest_addr());
IP6_STATS_INC(ip6.fw);
IP6_STATS_INC(ip6.xmit);
return FWD_FORWARDED;
}
