/*------------------------------------------------------------------------------*/
u8_t
uip_fw_forward(void)
{
struct fwcache_entry *fw;
/* First check if the packet is destined for ourselves and return 0
to indicate that the packet should be processed locally. */
if(BUF->destipaddr[0] == uip_hostaddr[0] &&
BUF->destipaddr[1] == uip_hostaddr[1]) {
return UIP_FW_LOCAL;
}
/* If we use ping IP address configuration, and our IP address is
not yet configured, we should intercept all ICMP echo packets. */
#if UIP_PINGADDRCONF
if((uip_hostaddr[0] | uip_hostaddr[1]) == 0 &&
BUF->proto == UIP_PROTO_ICMP &&
ICMPBUF->type == ICMP_ECHO) {
return UIP_FW_LOCAL;
}
#endif /* UIP_PINGADDRCONF */
/* Check if the packet is in the forwarding cache already, and if so
we drop it. */
for(fw = fwcache; fw < &fwcache[FWCACHE_SIZE]; ++fw) {
if(fw->timer != 0 &&
#if UIP_REASSEMBLY > 0
fw->len == BUF->len &&
fw->offset == BUF->ipoffset &&
#endif
fw->ipid == BUF->ipid &&
fw->srcipaddr[0] == BUF->srcipaddr[0] &&
fw->srcipaddr[1] == BUF->srcipaddr[1] &&
fw->destipaddr[0] == BUF->destipaddr[0] &&
fw->destipaddr[1] == BUF->destipaddr[1] &&
#if notdef
fw->payload[0] == BUF->srcport &&
fw->payload[1] == BUF->destport &&
#endif
fw->proto == BUF->proto) {
/* Drop packet. */
return UIP_FW_FORWARDED;
}
}
/* If the TTL reaches zero we produce an ICMP time exceeded message
in the uip_buf buffer and forward that packet back to the sender
of the packet. */
if(BUF->ttl <= 1) {
/* No time exceeded for broadcasts and multicasts! */
if(BUF->destipaddr[0] == 0xffff && BUF->destipaddr[1] == 0xffff) {
return UIP_FW_LOCAL;
}
time_exceeded();
}
/* Decrement the TTL (time-to-live) value in the IP header */
BUF->ttl = BUF->ttl - 1;
/* Update the IP checksum. */
if(BUF->ipchksum >= HTONS(0xffff - 0x0100)) {
BUF->ipchksum = BUF->ipchksum + HTONS(0x0100) + 1;
} else {
BUF->ipchksum = BUF->ipchksum + HTONS(0x0100);
}
if(uip_len > 0) {
uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_TCPIP_HLEN];
uip_fw_output();
}
#if UIP_BROADCAST
if(BUF->destipaddr[0] == 0xffff && BUF->destipaddr[1] == 0xffff) {
return UIP_FW_LOCAL;
}
#endif /* UIP_BROADCAST */
/* Return non-zero to indicate that the packet was forwarded and that no
other processing should be made. */
return UIP_FW_FORWARDED;
}
/*-----------------------------------------------------------------------------*/
void
uip_split_output(void)
{
u16_t tcplen, len1, len2;
/* We only try to split maximum sized TCP segments. */
if(BUF->proto == UIP_PROTO_TCP &&
uip_len == UIP_BUFSIZE - UIP_LLH_LEN) {
tcplen = uip_len - UIP_TCPIP_HLEN;
/* Split the segment in two. If the original packet length was
odd, we make the second packet one byte larger. */
len1 = len2 = tcplen / 2;
if(len1 + len2 < tcplen) {
++len2;
}
/* Create the first packet. This is done by altering the length
field of the IP header and updating the checksums. */
uip_len = len1 + UIP_TCPIP_HLEN;
#if UIP_CONF_IPV6
/* For IPv6, the IP length field does not include the IPv6 IP header
length. */
BUF->len[0] = ((uip_len - UIP_IPH_LEN) >> 8);
BUF->len[1] = ((uip_len - UIP_IPH_LEN) & 0xff);
#else /* UIP_CONF_IPV6 */
BUF->len[0] = uip_len >> 8;
BUF->len[1] = uip_len & 0xff;
#endif /* UIP_CONF_IPV6 */
/* Recalculate the TCP checksum. */
BUF->tcpchksum = 0;
BUF->tcpchksum = ~(uip_tcpchksum());
#if !UIP_CONF_IPV6
/* Recalculate the IP checksum. */
BUF->ipchksum = 0;
BUF->ipchksum = ~(uip_ipchksum());
#endif /* UIP_CONF_IPV6 */
/* Transmit the first packet. */
uip_fw_output();
// tcpip_output();
/* Now, create the second packet. To do this, it is not enough to
just alter the length field, but we must also update the TCP
sequence number and point the uip_appdata to a new place in
memory. This place is detemined by the length of the first
packet (len1). */
uip_len = len2 + UIP_TCPIP_HLEN;
#if UIP_CONF_IPV6
/* For IPv6, the IP length field does not include the IPv6 IP header
length. */
BUF->len[0] = ((uip_len - UIP_IPH_LEN) >> 8);
BUF->len[1] = ((uip_len - UIP_IPH_LEN) & 0xff);
#else /* UIP_CONF_IPV6 */
BUF->len[0] = uip_len >> 8;
BUF->len[1] = uip_len & 0xff;
#endif /* UIP_CONF_IPV6 */
/* uip_appdata += len1;*/
memcpy(uip_appdata, (u8_t *)uip_appdata + len1, len2);
uip_add32(BUF->seqno, len1);
BUF->seqno[0] = uip_acc32[0];
BUF->seqno[1] = uip_acc32[1];
BUF->seqno[2] = uip_acc32[2];
BUF->seqno[3] = uip_acc32[3];
/* Recalculate the TCP checksum. */
BUF->tcpchksum = 0;
BUF->tcpchksum = ~(uip_tcpchksum());
#if !UIP_CONF_IPV6
/* Recalculate the IP checksum. */
BUF->ipchksum = 0;
BUF->ipchksum = ~(uip_ipchksum());
#endif /* UIP_CONF_IPV6 */
/* Transmit the second packet. */
uip_fw_output();
// tcpip_output();
} else {
