/*---------------------------------------------------------------------------*/
void
uip_ds6_select_src(uip_ipaddr_t *src, uip_ipaddr_t *dst)
{
uint8_t best = 0; /* number of bit in common with best match */
uint8_t n = 0;
uip_ds6_addr_t *matchaddr = NULL;
if(!uip_is_addr_link_local(dst) && !uip_is_addr_mcast(dst)) {
/* find longest match */
for(locaddr = uip_ds6_if.addr_list;
locaddr < uip_ds6_if.addr_list + UIP_DS6_ADDR_NB; locaddr++) {
/* Only preferred global (not link-local) addresses */
if(locaddr->isused && locaddr->state == ADDR_PREFERRED &&
!uip_is_addr_link_local(&locaddr->ipaddr)) {
n = get_match_length(dst, &locaddr->ipaddr);
if(n >= best) {
best = n;
matchaddr = locaddr;
}
}
}
} else {
matchaddr = uip_ds6_get_link_local(ADDR_PREFERRED);
}
/* use the :: (unspecified address) as source if no match found */
if(matchaddr == NULL) {
uip_create_unspecified(src);
} else {
uip_ipaddr_copy(src, &matchaddr->ipaddr);
}
#if UIP_CONF_LOOPBACK
// FIXME: there's probably a better way to do this
if(uip_is_addr_loopback(dst)) {
uip_ipaddr_copy(src, dst);
}
#endif /* UIP_CONF_LOOPBACK */
}
/*---------------------------------------------------------------------------*/
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;
}
