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-rw-r--r--main/common/tcpstuff.c202
1 files changed, 102 insertions, 100 deletions
diff --git a/main/common/tcpstuff.c b/main/common/tcpstuff.c
index 8122637..f43e60a 100644
--- a/main/common/tcpstuff.c
+++ b/main/common/tcpstuff.c
@@ -1,7 +1,7 @@
/**************************************************************************
*
* Copyright (c) 2013 Alcatel-Lucent
- *
+ *
* Alcatel Lucent licenses this file to You under the Apache License,
* Version 2.0 (the "License"); you may not use this file except in
* compliance with the License. A copy of the License is contained the
@@ -43,126 +43,128 @@
#include "stddefs.h"
/* SendTcpConnectionReset():
- * Called in response to any incoming TCP request.
- * It is used to let the sender know that the TCP connection is being
- * refused.
+ * Called in response to any incoming TCP request.
+ * It is used to let the sender know that the TCP connection is being
+ * refused.
*/
int
SendTcpConnectionReset(struct ether_header *re)
{
- short datalen, flags;
- ulong ackno;
- struct ether_header *te;
- struct ip *ti, *ri;
- struct tcphdr *ttcp, *rtcp;
-
- ri = (struct ip *) (re + 1);
- datalen = ecs(ri->ip_len) - ((ri->ip_vhl & 0x0f) * 4);
-
- te = EtherCopy(re);
- ti = (struct ip *) (te + 1);
- ti->ip_vhl = ri->ip_vhl;
- ti->ip_tos = ri->ip_tos;
- ti->ip_len = ri->ip_len;
- ti->ip_id = ri->ip_id;
- ti->ip_off = ecs(IP_DONTFRAG);
- ti->ip_ttl = ri->ip_ttl/2;
- ti->ip_p = ri->ip_p;
- memcpy((char *)&(ti->ip_src.s_addr),(char *)&(ri->ip_dst.s_addr),
- sizeof(struct in_addr));
- memcpy((char *)&(ti->ip_dst.s_addr),(char *)&(ri->ip_src.s_addr),
- sizeof(struct in_addr));
-
- ttcp = (struct tcphdr *) (ti + 1);
- rtcp = (struct tcphdr *) (ri + 1);
- flags = ecs(rtcp->flags);
- flags &= ~TCP_FLAGMASK;
- flags |= (TCP_ACK | TCP_RESET);
- ttcp->flags = ecs(flags);
- ttcp->sport = rtcp->dport;
- ttcp->dport = rtcp->sport;
- memset((char *)&ttcp->seqno,0,4);
- memcpy((char *)&ackno,(char *)&rtcp->seqno,4);
- self_ecl(ackno);
- ackno+=1;
- self_ecl(ackno);
- memcpy((char *)&ttcp->ackno,(char *)&ackno,4);
-
- ttcp->windowsize = 0;
- ttcp->urgentptr = 0;
- memcpy((char *)(ttcp+1),(char *)(rtcp+1),datalen-sizeof(struct tcphdr));
-
- ipChksum(ti); /* compute checksum of ip hdr: (3rd Edition Comer pg 100) */
- tcpChksum(ti); /* Compute TCP checksum */
-
- sendBuffer(sizeof(struct ether_header) + ecs(ti->ip_len));
- return(0);
+ short datalen, flags;
+ ulong ackno;
+ struct ether_header *te;
+ struct ip *ti, *ri;
+ struct tcphdr *ttcp, *rtcp;
+
+ ri = (struct ip *)(re + 1);
+ datalen = ecs(ri->ip_len) - ((ri->ip_vhl & 0x0f) * 4);
+
+ te = EtherCopy(re);
+ ti = (struct ip *)(te + 1);
+ ti->ip_vhl = ri->ip_vhl;
+ ti->ip_tos = ri->ip_tos;
+ ti->ip_len = ri->ip_len;
+ ti->ip_id = ri->ip_id;
+ ti->ip_off = ecs(IP_DONTFRAG);
+ ti->ip_ttl = ri->ip_ttl/2;
+ ti->ip_p = ri->ip_p;
+ memcpy((char *)&(ti->ip_src.s_addr),(char *)&(ri->ip_dst.s_addr),
+ sizeof(struct in_addr));
+ memcpy((char *)&(ti->ip_dst.s_addr),(char *)&(ri->ip_src.s_addr),
+ sizeof(struct in_addr));
+
+ ttcp = (struct tcphdr *)(ti + 1);
+ rtcp = (struct tcphdr *)(ri + 1);
+ flags = ecs(rtcp->flags);
+ flags &= ~TCP_FLAGMASK;
+ flags |= (TCP_ACK | TCP_RESET);
+ ttcp->flags = ecs(flags);
+ ttcp->sport = rtcp->dport;
+ ttcp->dport = rtcp->sport;
+ memset((char *)&ttcp->seqno,0,4);
+ memcpy((char *)&ackno,(char *)&rtcp->seqno,4);
+ self_ecl(ackno);
+ ackno+=1;
+ self_ecl(ackno);
+ memcpy((char *)&ttcp->ackno,(char *)&ackno,4);
+
+ ttcp->windowsize = 0;
+ ttcp->urgentptr = 0;
+ memcpy((char *)(ttcp+1),(char *)(rtcp+1),datalen-sizeof(struct tcphdr));
+
+ ipChksum(ti); /* compute checksum of ip hdr: (3rd Edition Comer pg 100) */
+ tcpChksum(ti); /* Compute TCP checksum */
+
+ sendBuffer(sizeof(struct ether_header) + ecs(ti->ip_len));
+ return(0);
}
-/* tcpChksum():
- * Compute the checksum of the TCP packet.
- * The incoming pointer is to an ip header, the tcp header after that ip
- * header is directly populated with the result. Similar to the udp
- * checksum calculation. This one is mandatory.
+/* tcpChksum():
+ * Compute the checksum of the TCP packet.
+ * The incoming pointer is to an ip header, the tcp header after that ip
+ * header is directly populated with the result. Similar to the udp
+ * checksum calculation. This one is mandatory.
*/
void
tcpChksum(struct ip *ihdr)
{
- register int i;
- register ushort *sp;
- register ulong t;
- short len;
- struct tcphdr *thdr;
- struct UdpPseudohdr pseudohdr;
-
- thdr = (struct tcphdr *)(ihdr+1);
- thdr->tcpcsum = 0;
-
- /* Start by building the pseudo header: */
- memcpy((char *)&pseudohdr.ip_src.s_addr,(char *)&ihdr->ip_src.s_addr,4);
- memcpy((char *)&pseudohdr.ip_dst.s_addr,(char *)&ihdr->ip_dst.s_addr,4);
- pseudohdr.zero = 0;
- pseudohdr.proto = ihdr->ip_p;
- len = ecs(ihdr->ip_len) - sizeof(struct ip);
- pseudohdr.ulen = ecs(len);
-
- /* Get checksum of pseudo header: */
- sp = (ushort *) &pseudohdr;
- for (i=0,t=0;i<(sizeof(struct UdpPseudohdr)/sizeof(ushort));i++,sp++)
- t += *sp;
-
- /* If length is odd, pad and add one. */
- if (len & 1) {
- uchar *ucp;
- ucp = (uchar *)thdr;
- ucp[len] = 0;
- len++;
- }
- len >>= 1;
-
- sp = (ushort *) thdr;
- for (i=0;i<len;i++,sp++)
- t += *sp;
- t = (t & 0xffff) + (t >> 16);
- thdr->tcpcsum = ~t;
+ register int i;
+ register ushort *sp;
+ register ulong t;
+ short len;
+ struct tcphdr *thdr;
+ struct UdpPseudohdr pseudohdr;
+
+ thdr = (struct tcphdr *)(ihdr+1);
+ thdr->tcpcsum = 0;
+
+ /* Start by building the pseudo header: */
+ memcpy((char *)&pseudohdr.ip_src.s_addr,(char *)&ihdr->ip_src.s_addr,4);
+ memcpy((char *)&pseudohdr.ip_dst.s_addr,(char *)&ihdr->ip_dst.s_addr,4);
+ pseudohdr.zero = 0;
+ pseudohdr.proto = ihdr->ip_p;
+ len = ecs(ihdr->ip_len) - sizeof(struct ip);
+ pseudohdr.ulen = ecs(len);
+
+ /* Get checksum of pseudo header: */
+ sp = (ushort *) &pseudohdr;
+ for(i=0,t=0; i<(sizeof(struct UdpPseudohdr)/sizeof(ushort)); i++,sp++) {
+ t += *sp;
+ }
+
+ /* If length is odd, pad and add one. */
+ if(len & 1) {
+ uchar *ucp;
+ ucp = (uchar *)thdr;
+ ucp[len] = 0;
+ len++;
+ }
+ len >>= 1;
+
+ sp = (ushort *) thdr;
+ for(i=0; i<len; i++,sp++) {
+ t += *sp;
+ }
+ t = (t & 0xffff) + (t >> 16);
+ thdr->tcpcsum = ~t;
}
void
tcperrmsg(char *msg)
{
- printf("TCP error: %s\n",msg);
+ printf("TCP error: %s\n",msg);
}
void
processTCP(struct ether_header *ehdr,ushort size)
{
- //struct ip *ipp;
- //struct tcphdr *tcpp;
+ //struct ip *ipp;
+ //struct tcphdr *tcpp;
- //ipp = (struct ip *)(ehdr + 1);
- //tcpp = (struct tcphdr *)((char *)ipp + IP_HLEN(ipp));
- SendTcpConnectionReset(ehdr);
- return;
+ //ipp = (struct ip *)(ehdr + 1);
+ //tcpp = (struct tcphdr *)((char *)ipp + IP_HLEN(ipp));
+ SendTcpConnectionReset(ehdr);
+ return;
}
#endif
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