📄 uip.lst
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535 void
536 uip_listen(u16_t port)
537 {
538 1 for(c = 0; c < UIP_LISTENPORTS; ++c) {
539 2 if(uip_listenports[c] == 0) {
540 3 uip_listenports[c] = port;
541 3 return;
542 3 }
543 2 }
544 1 }
545 /*---------------------------------------------------------------------------*/
546 /* XXX: IP fragment reassembly: not well-tested. */
547
548 #if UIP_REASSEMBLY && !UIP_CONF_IPV6
#define UIP_REASS_BUFSIZE (UIP_BUFSIZE - UIP_LLH_LEN)
static u8_t uip_reassbuf[UIP_REASS_BUFSIZE];
C51 COMPILER V7.06 UIP 05/02/2009 15:51:22 PAGE 10
static u8_t uip_reassbitmap[UIP_REASS_BUFSIZE / (8 * 8)];
static const u8_t bitmap_bits[8] = {0xff, 0x7f, 0x3f, 0x1f,
0x0f, 0x07, 0x03, 0x01};
static u16_t uip_reasslen;
static u8_t uip_reassflags;
#define UIP_REASS_FLAG_LASTFRAG 0x01
static u8_t uip_reasstmr;
#define IP_MF 0x20
static u8_t
uip_reass(void)
{
u16_t offset, len;
u16_t i;
/* If ip_reasstmr is zero, no packet is present in the buffer, so we
write the IP header of the fragment into the reassembly
buffer. The timer is updated with the maximum age. */
if(uip_reasstmr == 0) {
memcpy(uip_reassbuf, &BUF->vhl, UIP_IPH_LEN);
uip_reasstmr = UIP_REASS_MAXAGE;
uip_reassflags = 0;
/* Clear the bitmap. */
memset(uip_reassbitmap, 0, sizeof(uip_reassbitmap));
}
/* Check if the incoming fragment matches the one currently present
in the reasembly buffer. If so, we proceed with copying the
fragment into the buffer. */
if(BUF->srcipaddr[0] == FBUF->srcipaddr[0] &&
BUF->srcipaddr[1] == FBUF->srcipaddr[1] &&
BUF->destipaddr[0] == FBUF->destipaddr[0] &&
BUF->destipaddr[1] == FBUF->destipaddr[1] &&
BUF->ipid[0] == FBUF->ipid[0] &&
BUF->ipid[1] == FBUF->ipid[1]) {
len = (BUF->len[0] << 8) + BUF->len[1] - (BUF->vhl & 0x0f) * 4;
offset = (((BUF->ipoffset[0] & 0x3f) << 8) + BUF->ipoffset[1]) * 8;
/* If the offset or the offset + fragment length overflows the
reassembly buffer, we discard the entire packet. */
if(offset > UIP_REASS_BUFSIZE ||
offset + len > UIP_REASS_BUFSIZE) {
uip_reasstmr = 0;
goto nullreturn;
}
/* Copy the fragment into the reassembly buffer, at the right
offset. */
memcpy(&uip_reassbuf[UIP_IPH_LEN + offset],
(char *)BUF + (int)((BUF->vhl & 0x0f) * 4),
len);
/* Update the bitmap. */
if(offset / (8 * 8) == (offset + len) / (8 * 8)) {
/* If the two endpoints are in the same byte, we only update
that byte. */
uip_reassbitmap[offset / (8 * 8)] |=
bitmap_bits[(offset / 8 ) & 7] &
~bitmap_bits[((offset + len) / 8 ) & 7];
C51 COMPILER V7.06 UIP 05/02/2009 15:51:22 PAGE 11
} else {
/* If the two endpoints are in different bytes, we update the
bytes in the endpoints and fill the stuff inbetween with
0xff. */
uip_reassbitmap[offset / (8 * 8)] |=
bitmap_bits[(offset / 8 ) & 7];
for(i = 1 + offset / (8 * 8); i < (offset + len) / (8 * 8); ++i) {
uip_reassbitmap[i] = 0xff;
}
uip_reassbitmap[(offset + len) / (8 * 8)] |=
~bitmap_bits[((offset + len) / 8 ) & 7];
}
/* If this fragment has the More Fragments flag set to zero, we
know that this is the last fragment, so we can calculate the
size of the entire packet. We also set the
IP_REASS_FLAG_LASTFRAG flag to indicate that we have received
the final fragment. */
if((BUF->ipoffset[0] & IP_MF) == 0) {
uip_reassflags |= UIP_REASS_FLAG_LASTFRAG;
uip_reasslen = offset + len;
}
/* Finally, we check if we have a full packet in the buffer. We do
this by checking if we have the last fragment and if all bits
in the bitmap are set. */
if(uip_reassflags & UIP_REASS_FLAG_LASTFRAG) {
/* Check all bytes up to and including all but the last byte in
the bitmap. */
for(i = 0; i < uip_reasslen / (8 * 8) - 1; ++i) {
if(uip_reassbitmap[i] != 0xff) {
goto nullreturn;
}
}
/* Check the last byte in the bitmap. It should contain just the
right amount of bits. */
if(uip_reassbitmap[uip_reasslen / (8 * 8)] !=
(u8_t)~bitmap_bits[uip_reasslen / 8 & 7]) {
goto nullreturn;
}
/* If we have come this far, we have a full packet in the
buffer, so we allocate a pbuf and copy the packet into it. We
also reset the timer. */
uip_reasstmr = 0;
memcpy(BUF, FBUF, uip_reasslen);
/* Pretend to be a "normal" (i.e., not fragmented) IP packet
from now on. */
BUF->ipoffset[0] = BUF->ipoffset[1] = 0;
BUF->len[0] = uip_reasslen >> 8;
BUF->len[1] = uip_reasslen & 0xff;
BUF->ipchksum = 0;
BUF->ipchksum = ~(uip_ipchksum());
return uip_reasslen;
}
}
nullreturn:
return 0;
C51 COMPILER V7.06 UIP 05/02/2009 15:51:22 PAGE 12
}
#endif /* UIP_REASSEMBLY */
677 /*---------------------------------------------------------------------------*/
678 static void
679 uip_add_rcv_nxt(u16_t n)
680 {
681 1 uip_add32(uip_conn->rcv_nxt, n);
682 1 uip_conn->rcv_nxt[0] = uip_acc32[0];
683 1 uip_conn->rcv_nxt[1] = uip_acc32[1];
684 1 uip_conn->rcv_nxt[2] = uip_acc32[2];
685 1 uip_conn->rcv_nxt[3] = uip_acc32[3];
686 1 }
687 /*---------------------------------------------------------------------------*/
688 void
689 uip_process(u8_t flag)
690 {
691 1 // u8_t i;
692 1 register struct uip_conn xdata *uip_connr = uip_conn;/*gateway*/
693 1
694 1 #if UIP_UDP
if(flag == UIP_UDP_SEND_CONN) {
goto udp_send;
}
#endif /* UIP_UDP */
699 1
700 1 uip_sappdata = uip_appdata = &uip_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN];
701 1
702 1 /* Check if we were invoked because of a poll request for a
703 1 particular connection. */
704 1 if(flag == UIP_POLL_REQUEST) {
705 2 if((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_ESTABLISHED &&
706 2 !uip_outstanding(uip_connr)) {
707 3 uip_flags = UIP_POLL;
708 3 UIP_APPCALL();
709 3 goto appsend;
710 3 }
711 2 goto drop;
712 2
713 2 /* Check if we were invoked because of the perodic timer fireing. */
714 2 } else if(flag == UIP_TIMER) {
715 2 #if UIP_REASSEMBLY
if(uip_reasstmr != 0) {
--uip_reasstmr;
}
#endif /* UIP_REASSEMBLY */
720 2 /* Increase the initial sequence number. */
721 2 if(++iss[3] == 0) {
722 3 if(++iss[2] == 0) {
723 4 if(++iss[1] == 0) {
724 5 ++iss[0];
725 5 }
726 4 }
727 3 }
728 2
729 2 /* Reset the length variables. */
730 2 uip_len = 0;
731 2 uip_slen = 0;
732 2
733 2 /* Check if the connection is in a state in which we simply wait
734 2 for the connection to time out. If so, we increase the
735 2 connection's timer and remove the connection if it times
736 2 out. */
C51 COMPILER V7.06 UIP 05/02/2009 15:51:22 PAGE 13
737 2 if(uip_connr->tcpstateflags == UIP_TIME_WAIT ||
738 2 uip_connr->tcpstateflags == UIP_FIN_WAIT_2) {
739 3 ++(uip_connr->timer);
740 3 if(uip_connr->timer == UIP_TIME_WAIT_TIMEOUT) {
741 4 uip_connr->tcpstateflags = UIP_CLOSED;
742 4 }
743 3 } else if(uip_connr->tcpstateflags != UIP_CLOSED) {
744 3 /* If the connection has outstanding data, we increase the
745 3 connection's timer and see if it has reached the RTO value
746 3 in which case we retransmit. */
747 3 if(uip_outstanding(uip_connr)) {
748 4 if(uip_connr->timer-- == 0) {
749 5 if(uip_connr->nrtx == UIP_MAXRTX ||
750 5 ((uip_connr->tcpstateflags == UIP_SYN_SENT ||
751 5 uip_connr->tcpstateflags == UIP_SYN_RCVD) &&
752 5 uip_connr->nrtx == UIP_MAXSYNRTX)) {
753 6 uip_connr->tcpstateflags = UIP_CLOSED;
754 6
755 6 /* We call UIP_APPCALL() with uip_flags set to
756 6 UIP_TIMEDOUT to inform the application that the
757 6 connection has timed out. */
758 6 uip_flags = UIP_TIMEDOUT;
759 6 UIP_APPCALL();
760 6
761 6 /* We also send a reset packet to the remote host. */
762 6 BUF->flags = TCP_RST | TCP_ACK;
763 6 goto tcp_send_nodata;
764 6 }
765 5
766 5 /* Exponential backoff. */
767 5 uip_connr->timer = UIP_RTO << (uip_connr->nrtx > 4?
768 5 4:
769 5 uip_connr->nrtx);
770 5 ++(uip_connr->nrtx);
771 5
772 5 /* Ok, so we need to retransmit. We do this differently
773 5 depending on which state we are in. In ESTABLISHED, we
774 5 call upon the application so that it may prepare the
775 5 data for the retransmit. In SYN_RCVD, we resend the
776 5 SYNACK that we sent earlier and in LAST_ACK we have to
777 5 retransmit our FINACK. */
778 5 UIP_STAT(++uip_stat.tcp.rexmit);
779 5 switch(uip_connr->tcpstateflags & UIP_TS_MASK) {
780 6 case UIP_SYN_RCVD:
781 6 /* In the SYN_RCVD state, we should retransmit our
782 6 SYNACK. */
783 6 goto tcp_send_synack;
784 6
785 6 #if UIP_ACTIVE_OPEN
case UIP_SYN_SENT:
/* In the SYN_SENT state, we retransmit out SYN. */
BUF->flags = 0;
goto tcp_send_syn;
#endif /* UIP_ACTIVE_OPEN */
791 6
792 6 case UIP_ESTABLISHED:
793 6 /* In the ESTABLISHED state, we call upon the application
794 6 to do the actual retransmit after which we jump into
795 6 the code for sending out the packet (the apprexmit
796 6 label). */
797 6 uip_flags = UIP_REXMIT;
798 6 UIP_APPCALL();
C51 COMPILER V7.06 UIP 05/02/2009 15:51:22 PAGE 14
799 6 goto apprexmit;
800 6
801 6 case UIP_FIN_WAIT_1:
802 6 case UIP_CLOSING:
803 6 case UIP_LAST_ACK:
804 6 /* In all these states we should retransmit a FINACK. */
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