/*---------------------------------------------------------------------------*/
void
uip_process()
{
PRINTF("NEW packet\n");
/* Check validity of the IP header. */
if((UIP_IP_BUF->vtc & 0xf0) != 0x60) { /* IP version and header length. */
PRINTF("Wrong IP Version\n");
goto drop;
}
/*
* Check the size of the packet. If the size reported to us in
* uip_len is smaller the size reported in the IP header, we assume
* that the packet has been corrupted in transit. If the size of
* uip_len is larger than the size reported in the IP packet header,
* the packet has been padded and we set uip_len to the correct
* value..
*/
if((UIP_IP_BUF->len[0] << 8) + UIP_IP_BUF->len[1] <= uip_len) {
uip_len = (UIP_IP_BUF->len[0] << 8) + UIP_IP_BUF->len[1] + UIP_IPH_LEN;
/*
* The length reported in the IPv6 header is the
* length of the payload that follows the
* header. However, uIP uses the uip_len variable
* for holding the size of the entire packet,
* including the IP header. For IPv4 this is not a
* problem as the length field in the IPv4 header
* contains the length of the entire packet. But
* for IPv6 we need to add the size of the IPv6
* header (40 bytes).
*/
} else {
PRINTF("Wrong Length\n");
goto drop;
}
PRINTF("IPv6 packet received from ");
PRINT6ADDR(&UIP_IP_BUF->srcipaddr);
PRINTF(" to ");
PRINT6ADDR(&UIP_IP_BUF->destipaddr);
PRINTF("\n");
if(uip_is_addr_mcast(&UIP_IP_BUF->srcipaddr)){
PRINTF("Dropping packet, src is mcast\n");
goto drop;
}
/*
* Next header field processing. In IPv6, we can have extension headers,
* if present, the Hop-by-Hop Option must be processed before forwarding
* the packet.
*/
uip_next_hdr = &UIP_IP_BUF->proto;
uip_ext_len = 0;
uip_ext_bitmap = 0;
if (*uip_next_hdr == UIP_PROTO_HBHO) {
#if UIP_CONF_IPV6_CHECKS
uip_ext_bitmap |= UIP_EXT_HDR_BITMAP_HBHO;
#endif /*UIP_CONF_IPV6_CHECKS*/
switch(ext_hdr_options_process()) {
case 0:
/*continue*/
uip_next_hdr = &UIP_EXT_BUF->next;
uip_ext_len += (UIP_EXT_BUF->len << 3) + 8;
break;
case 1:
/*silently discard*/
goto drop;
case 2:
/* send icmp error message (created in ext_hdr_options_process)
* and discard*/
goto send;
}
}
/* TBD Some Parameter problem messages */
if(!uip_ds6_is_my_addr(&UIP_IP_BUF->destipaddr) &&
!uip_ds6_is_my_maddr(&UIP_IP_BUF->destipaddr)) {
if(!uip_is_addr_mcast(&UIP_IP_BUF->destipaddr) &&
!uip_is_addr_link_local(&UIP_IP_BUF->destipaddr) &&
!uip_is_addr_link_local(&UIP_IP_BUF->srcipaddr) &&
!uip_is_addr_unspecified(&UIP_IP_BUF->srcipaddr) &&
!uip_is_addr_loopback(&UIP_IP_BUF->destipaddr)) {
/* Check MTU */
if(uip_len > UIP_LINK_MTU) {
uip_icmp6_error_output(ICMP6_PACKET_TOO_BIG, 0, UIP_LINK_MTU);
goto send;
}
/* Check Hop Limit */
if(UIP_IP_BUF->ttl <= 1) {
uip_icmp6_error_output(ICMP6_TIME_EXCEEDED,
ICMP6_TIME_EXCEED_TRANSIT, 0);
goto send;
}
UIP_IP_BUF->ttl = UIP_IP_BUF->ttl - 1;
PRINTF("Forwarding packet to ");
PRINT6ADDR(&UIP_IP_BUF->destipaddr);
PRINTF("\n");
goto send;
} else {
if((uip_is_addr_link_local(&UIP_IP_BUF->srcipaddr)) &&
(!uip_is_addr_unspecified(&UIP_IP_BUF->srcipaddr)) &&
(!uip_is_addr_loopback(&UIP_IP_BUF->destipaddr)) &&
(!uip_is_addr_mcast(&UIP_IP_BUF->destipaddr)) &&
(!uip_ds6_is_addr_onlink((&UIP_IP_BUF->destipaddr)))) {
PRINTF("LL source address with off link destination, dropping\n");
uip_icmp6_error_output(ICMP6_DST_UNREACH,
ICMP6_DST_UNREACH_NOTNEIGHBOR, 0);
goto send;
}
PRINTF("Dropping packet, not for me and link local or multicast\n");
goto drop;
}
}
while(1) {
switch(*uip_next_hdr){
case UIP_PROTO_ICMP6:
/* ICMPv6 */
goto icmp6_input;
case UIP_PROTO_HBHO:
PRINTF("Processing hbh header\n");
/* Hop by hop option header */
#if UIP_CONF_IPV6_CHECKS
/* Hop by hop option header. If we saw one HBH already, drop */
if(uip_ext_bitmap & UIP_EXT_HDR_BITMAP_HBHO) {
goto bad_hdr;
} else {
uip_ext_bitmap |= UIP_EXT_HDR_BITMAP_HBHO;
}
#endif /*UIP_CONF_IPV6_CHECKS*/
switch(ext_hdr_options_process()) {
case 0:
/*continue*/
uip_next_hdr = &UIP_EXT_BUF->next;
uip_ext_len += (UIP_EXT_BUF->len << 3) + 8;
break;
case 1:
/*silently discard*/
goto drop;
case 2:
/* send icmp error message (created in ext_hdr_options_process)
* and discard*/
goto send;
}
break;
case UIP_PROTO_DESTO:
#if UIP_CONF_IPV6_CHECKS
/* Destination option header. if we saw two already, drop */
PRINTF("Processing desto header\n");
if(uip_ext_bitmap & UIP_EXT_HDR_BITMAP_DESTO1) {
if(uip_ext_bitmap & UIP_EXT_HDR_BITMAP_DESTO2) {
goto bad_hdr;
} else{
uip_ext_bitmap |= UIP_EXT_HDR_BITMAP_DESTO2;
}
} else {
uip_ext_bitmap |= UIP_EXT_HDR_BITMAP_DESTO1;
}
#endif /*UIP_CONF_IPV6_CHECKS*/
switch(ext_hdr_options_process()) {
case 0:
/*continue*/
uip_next_hdr = &UIP_EXT_BUF->next;
uip_ext_len += (UIP_EXT_BUF->len << 3) + 8;
break;
case 1:
/*silently discard*/
goto drop;
case 2:
/* send icmp error message (created in ext_hdr_options_process)
* and discard*/
goto send;
}
break;
case UIP_PROTO_ROUTING:
#if UIP_CONF_IPV6_CHECKS
/* Routing header. If we saw one already, drop */
if(uip_ext_bitmap & UIP_EXT_HDR_BITMAP_ROUTING) {
goto bad_hdr;
} else {
uip_ext_bitmap |= UIP_EXT_HDR_BITMAP_ROUTING;
}
#endif /*UIP_CONF_IPV6_CHECKS*/
/*
* Routing Header length field is in units of 8 bytes, excluding
* As per RFC2460 section 4.4, if routing type is unrecognized:
* if segments left = 0, ignore the header
* if segments left > 0, discard packet and send icmp error pointing
* to the routing type
*/
PRINTF("Processing Routing header\n");
if(UIP_ROUTING_BUF->seg_left > 0) {
uip_icmp6_error_output(ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, UIP_IPH_LEN + uip_ext_len + 2);
goto send;
}
uip_next_hdr = &UIP_EXT_BUF->next;
uip_ext_len += (UIP_EXT_BUF->len << 3) + 8;
break;
case UIP_PROTO_FRAG:
/* Fragmentation header:call the reassembly function, then leave */
goto drop;
case UIP_PROTO_NONE:
goto drop;
default:
goto bad_hdr;
}
}
bad_hdr:
/*
* RFC 2460 send error message parameterr problem, code unrecognized
* next header, pointing to the next header field
*/
uip_icmp6_error_output(ICMP6_PARAM_PROB, ICMP6_PARAMPROB_NEXTHEADER, (u32_t)(uip_next_hdr - (uint8_t *)UIP_IP_BUF));
goto send;
/* End of headers processing */
icmp6_input:
/* This is IPv6 ICMPv6 processing code. */
PRINTF("icmp6_input: length %d\n", uip_len);
#if UIP_CONF_IPV6_CHECKS
/* Compute and check the ICMP header checksum */
if(uip_icmp6chksum() != 0xffff) {
goto drop;
}
#endif /*UIP_CONF_IPV6_CHECKS*/
/*
* Here we process incoming ICMPv6 packets
* For echo request, we send echo reply
* For ND pkts, we call the appropriate function in uip-nd6.c
* We do not treat Error messages for now
* If no pkt is to be sent as an answer to the incoming one, we
* "goto drop". Else we just break; then at the after the "switch"
* we "goto send"
*/
switch(UIP_ICMP_BUF->type) {
case ICMP6_NS:
uip_len = 0;
break;
case ICMP6_NA:
uip_len = 0;
break;
case ICMP6_RS:
uip_len = 0;
break;
case ICMP6_RA:
uip_len = 0;
break;
case ICMP6_RPL:
uip_rpl_input();
break;
case ICMP6_ECHO_REQUEST:
uip_icmp6_echo_request_input();
break;
case ICMP6_ECHO_REPLY:
/** \note We don't implement any application callback for now */
PRINTF("Received an icmp6 echo reply\n");
uip_len = 0;
break;
default:
PRINTF("Unknown icmp6 message type %d\n", UIP_ICMP_BUF->type);
uip_len = 0;
break;
}
if(uip_len > 0) {
goto send;
} else {
goto drop;
}
/* End of IPv6 ICMP processing. */
UIP_IP_BUF->vtc = 0x60;
UIP_IP_BUF->tcflow = 0x00;
UIP_IP_BUF->flow = 0x00;
send:
PRINTF("Sending packet with length %d (%d)\n", uip_len,
(UIP_IP_BUF->len[0] << 8) | UIP_IP_BUF->len[1]);
/* Return and let the caller do the actual transmission. */
return;
drop:
uip_len = 0;
uip_ext_len = 0;
uip_ext_bitmap = 0;
return;
}
void
tcpip_ipv6_output(void)
{
uip_ds6_nbr_t *nbr = NULL;
uip_ipaddr_t *nexthop;
if(uip_len == 0) {
return;
}
if(uip_len > UIP_LINK_MTU) {
UIP_LOG("tcpip_ipv6_output: Packet to big");
uip_clear_buf();
return;
}
if(uip_is_addr_unspecified(&UIP_IP_BUF->destipaddr)){
UIP_LOG("tcpip_ipv6_output: Destination address unspecified");
uip_clear_buf();
return;
}
if(!uip_is_addr_mcast(&UIP_IP_BUF->destipaddr)) {
/* Next hop determination */
nbr = NULL;
/* We first check if the destination address is on our immediate
link. If so, we simply use the destination address as our
nexthop address. */
if(uip_ds6_is_addr_onlink(&UIP_IP_BUF->destipaddr)){
nexthop = &UIP_IP_BUF->destipaddr;
} else {
uip_ds6_route_t *route;
/* Check if we have a route to the destination address. */
route = uip_ds6_route_lookup(&UIP_IP_BUF->destipaddr);
/* No route was found - we send to the default route instead. */
if(route == NULL) {
PRINTF("tcpip_ipv6_output: no route found, using default route\n");
nexthop = uip_ds6_defrt_choose();
if(nexthop == NULL) {
#ifdef UIP_FALLBACK_INTERFACE
PRINTF("FALLBACK: removing ext hdrs & setting proto %d %d\n",
uip_ext_len, *((uint8_t *)UIP_IP_BUF + 40));
if(uip_ext_len > 0) {
extern void remove_ext_hdr(void);
uint8_t proto = *((uint8_t *)UIP_IP_BUF + 40);
remove_ext_hdr();
/* This should be copied from the ext header... */
UIP_IP_BUF->proto = proto;
}
/* Inform the other end that the destination is not reachable. If it's
* not informed routes might get lost unexpectedly until there's a need
* to send a new packet to the peer */
if(UIP_FALLBACK_INTERFACE.output() < 0) {
PRINTF("FALLBACK: output error. Reporting DST UNREACH\n");
uip_icmp6_error_output(ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADDR, 0);
uip_flags = 0;
tcpip_ipv6_output();
return;
}
#else
PRINTF("tcpip_ipv6_output: Destination off-link but no route\n");
#endif /* !UIP_FALLBACK_INTERFACE */
uip_clear_buf();
return;
}
} else {
/* A route was found, so we look up the nexthop neighbor for
the route. */
nexthop = uip_ds6_route_nexthop(route);
/* If the nexthop is dead, for example because the neighbor
never responded to link-layer acks, we drop its route. */
if(nexthop == NULL) {
#if UIP_CONF_IPV6_RPL
/* If we are running RPL, and if we are the root of the
network, we'll trigger a global repair berfore we remove
the route. */
rpl_dag_t *dag;
rpl_instance_t *instance;
dag = (rpl_dag_t *)route->state.dag;
if(dag != NULL) {
instance = dag->instance;
rpl_repair_root(instance->instance_id);
}
#endif /* UIP_CONF_IPV6_RPL */
uip_ds6_route_rm(route);
/* We don't have a nexthop to send the packet to, so we drop
it. */
return;
}
}
#if TCPIP_CONF_ANNOTATE_TRANSMISSIONS
if(nexthop != NULL) {
static uint8_t annotate_last;
static uint8_t annotate_has_last = 0;
if(annotate_has_last) {
printf("#L %u 0; red\n", annotate_last);
}
printf("#L %u 1; red\n", nexthop->u8[sizeof(uip_ipaddr_t) - 1]);
annotate_last = nexthop->u8[sizeof(uip_ipaddr_t) - 1];
annotate_has_last = 1;
}
#endif /* TCPIP_CONF_ANNOTATE_TRANSMISSIONS */
}
/* End of next hop determination */
#if UIP_CONF_IPV6_RPL
if(rpl_update_header_final(nexthop)) {
uip_clear_buf();
return;
}
#endif /* UIP_CONF_IPV6_RPL */
nbr = uip_ds6_nbr_lookup(nexthop);
if(nbr == NULL) {
#if UIP_ND6_SEND_NA
if((nbr = uip_ds6_nbr_add(nexthop, NULL, 0, NBR_INCOMPLETE)) == NULL) {
uip_clear_buf();
return;
} else {
#if UIP_CONF_IPV6_QUEUE_PKT
/* Copy outgoing pkt in the queuing buffer for later transmit. */
if(uip_packetqueue_alloc(&nbr->packethandle, UIP_DS6_NBR_PACKET_LIFETIME) != NULL) {
memcpy(uip_packetqueue_buf(&nbr->packethandle), UIP_IP_BUF, uip_len);
uip_packetqueue_set_buflen(&nbr->packethandle, uip_len);
}
#endif
/* RFC4861, 7.2.2:
* "If the source address of the packet prompting the solicitation is the
* same as one of the addresses assigned to the outgoing interface, that
* address SHOULD be placed in the IP Source Address of the outgoing
* solicitation. Otherwise, any one of the addresses assigned to the
* interface should be used."*/
if(uip_ds6_is_my_addr(&UIP_IP_BUF->srcipaddr)){
uip_nd6_ns_output(&UIP_IP_BUF->srcipaddr, NULL, &nbr->ipaddr);
} else {
uip_nd6_ns_output(NULL, NULL, &nbr->ipaddr);
}
stimer_set(&nbr->sendns, uip_ds6_if.retrans_timer / 1000);
nbr->nscount = 1;
/* Send the first NS try from here (multicast destination IP address). */
}
#else /* UIP_ND6_SEND_NA */
uip_len = 0;
return;
#endif /* UIP_ND6_SEND_NA */
} else {
#if UIP_ND6_SEND_NA
if(nbr->state == NBR_INCOMPLETE) {
PRINTF("tcpip_ipv6_output: nbr cache entry incomplete\n");
#if UIP_CONF_IPV6_QUEUE_PKT
/* Copy outgoing pkt in the queuing buffer for later transmit and set
the destination nbr to nbr. */
if(uip_packetqueue_alloc(&nbr->packethandle, UIP_DS6_NBR_PACKET_LIFETIME) != NULL) {
memcpy(uip_packetqueue_buf(&nbr->packethandle), UIP_IP_BUF, uip_len);
uip_packetqueue_set_buflen(&nbr->packethandle, uip_len);
}
#endif /*UIP_CONF_IPV6_QUEUE_PKT*/
uip_clear_buf();
return;
}
/* Send in parallel if we are running NUD (nbc state is either STALE,
DELAY, or PROBE). See RFC 4861, section 7.3.3 on node behavior. */
if(nbr->state == NBR_STALE) {
nbr->state = NBR_DELAY;
stimer_set(&nbr->reachable, UIP_ND6_DELAY_FIRST_PROBE_TIME);
nbr->nscount = 0;
PRINTF("tcpip_ipv6_output: nbr cache entry stale moving to delay\n");
}
#endif /* UIP_ND6_SEND_NA */
tcpip_output(uip_ds6_nbr_get_ll(nbr));
#if UIP_CONF_IPV6_QUEUE_PKT
/*
* Send the queued packets from here, may not be 100% perfect though.
* This happens in a few cases, for example when instead of receiving a
* NA after sendiong a NS, you receive a NS with SLLAO: the entry moves
* to STALE, and you must both send a NA and the queued packet.
*/
if(uip_packetqueue_buflen(&nbr->packethandle) != 0) {
uip_len = uip_packetqueue_buflen(&nbr->packethandle);
memcpy(UIP_IP_BUF, uip_packetqueue_buf(&nbr->packethandle), uip_len);
uip_packetqueue_free(&nbr->packethandle);
tcpip_output(uip_ds6_nbr_get_ll(nbr));
}
#endif /*UIP_CONF_IPV6_QUEUE_PKT*/
uip_clear_buf();
return;
}
}
/* Multicast IP destination address. */
tcpip_output(NULL);
uip_clear_buf();
}
/**
* \brief Process the options in Destination and Hop By Hop extension headers
*/
static u8_t
ext_hdr_options_process() {
/*
* Length field in the extension header: length of th eheader in units of
* 8 bytes, excluding the first 8 bytes
* length field in an option : the length of data in the option
*/
uip_ext_opt_offset = 2;
while(uip_ext_opt_offset < ((UIP_EXT_BUF->len << 3) + 8)) {
switch (UIP_EXT_HDR_OPT_BUF->type) {
/*
* for now we do not support any options except padding ones
* PAD1 does not make sense as the header must be 8bytes aligned,
* hence we can only have
*/
case UIP_EXT_HDR_OPT_PAD1:
PRINTF("Processing PAD1 option\n");
uip_ext_opt_offset += 1;
break;
case UIP_EXT_HDR_OPT_PADN:
PRINTF("Processing PADN option\n");
uip_ext_opt_offset += UIP_EXT_HDR_OPT_PADN_BUF->opt_len + 2;
break;
case UIP_EXT_HDR_OPT_RPL:
PRINTF("Processing RPL option\n");
if (rpl_verify_header(uip_ext_opt_offset)) {
PRINTF("RPL Option Error : Dropping Packet");
return 1;
}
uip_ext_opt_offset += (UIP_EXT_HDR_OPT_RPL_BUF->opt_len) + 2;
return 0;
default:
/*
* check the two highest order bits of the option
* - 00 skip over this option and continue processing the header.
* - 01 discard the packet.
* - 10 discard the packet and, regardless of whether or not the
* packet's Destination Address was a multicast address, send an
* ICMP Parameter Problem, Code 2, message to the packet's
* Source Address, pointing to the unrecognized Option Type.
* - 11 discard the packet and, only if the packet's Destination
* Address was not a multicast address, send an ICMP Parameter
* Problem, Code 2, message to the packet's Source Address,
* pointing to the unrecognized Option Type.
*/
PRINTF("MSB %x\n", UIP_EXT_HDR_OPT_BUF->type);
switch(UIP_EXT_HDR_OPT_BUF->type & 0xC0) {
case 0:
break;
case 0x40:
return 1;
case 0xC0:
if(uip_is_addr_mcast(&UIP_IP_BUF->destipaddr)) {
return 1;
}
case 0x80:
uip_icmp6_error_output(ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION,
(u32_t)UIP_IPH_LEN + uip_ext_len + uip_ext_opt_offset);
return 2;
}
/* in the cases were we did not discard, update ext_opt* */
uip_ext_opt_offset += UIP_EXT_HDR_OPT_BUF->len + 2;
break;
}
}
return 0;
}