Improve connection support by adding DEAD and IGNORE states

diff --git a/connections.c b/connections.c
index 4d04d46faa083898eff9e47334a819b6578f8ba7..732399ed1ffc96abc6ac0cb9b42ee005d38f44d2 100644 (file)
--- a/connections.c
+++ b/connections.c
@@ -22,9 +22,11 @@ Date: 02/2013
 ******************************************************************************/
 #include "dccp2tcp.h"
 
+int isClosed(struct hcon *A, struct hcon *B, int pkt_type);
+
 /*Lookup a connection. If it doesn't exist, add a new connection and return it.*/
 int get_host(u_char *src_id, u_char* dest_id, int id_len, int src_port, int dest_port,
-               struct hcon **fwd, struct hcon **rev){
+               int pkt_type, struct hcon **fwd, struct hcon **rev){
        struct connection *ptr;
 
        /*Empty list*/
@@ -41,13 +43,13 @@ int get_host(u_char *src_id, u_char* dest_id, int id_len, int src_port, int dest
        ptr=chead;
        while(ptr!=NULL){
                if(memcmp(ptr->A.id,src_id,id_len)==0 && ptr->A.port==src_port &&
-                               !(ptr->A.state==CLOSE && ptr->B.state==CLOSE)){
+                               !isClosed(&ptr->A, &ptr->B, pkt_type)){
                        *fwd=&ptr->A;
                        *rev=&ptr->B;
                        return 0;
                }
                if(memcmp(ptr->B.id,src_id,id_len)==0 && ptr->B.port==src_port &&
-                               !(ptr->B.state==CLOSE && ptr->A.state==CLOSE)){
+                               !isClosed(&ptr->A, &ptr->B, pkt_type)){
                        *fwd=&ptr->B;
                        *rev=&ptr->A;
                        return 0;
@@ -65,6 +67,25 @@ int get_host(u_char *src_id, u_char* dest_id, int id_len, int src_port, int dest
        return 0;
 }
 
+/*Returns true if the connection is closed and any packets should go to
+ * a new connection with the same four-tuple*/
+int isClosed(struct hcon *A, struct hcon *B, int pkt_type){
+       if(pkt_type==DCCP_PKT_REQUEST || pkt_type==DCCP_PKT_RESPONSE){
+               if(A->state==CLOSE && B->state==CLOSE){
+                       /*We're opening a new connection on hosts/ports we've used before, mark
+                        * old connection as dead*/
+                       A->state=DEAD;
+                       B->state=DEAD;
+                       return TRUE;
+               }
+       }else{
+               if(A->state==DEAD || B->state==DEAD){
+                       return TRUE;
+               }
+       }
+       return FALSE;
+}
+
 /*Add a connection. Return it. On failure, return NULL*/
 struct connection *add_connection(u_char *src_id, u_char* dest_id, int id_len, int src_port, int dest_port){
        struct connection *ptr;
@@ -177,7 +198,7 @@ u_int32_t add_new_seq(struct hcon *hcn, __be32 num, int size, enum dccp_pkt_type
        while(hcn->table[hcn->cur].old +1 < num && hcn->table[hcn->cur].old +1 > 0){
                prev=hcn->cur;
                if(num - hcn->table[hcn->cur].old +1 <100){
-                       dbgprintf(1,"Missing Packet: %X\n",hcn->table[prev].new+1);
+                       dbgprintf(1,"Missing Packet %i\n",hcn->table[prev].new+1);
                }
                hcn->cur=(hcn->cur+1)%(hcn->size);/*find next available table slot*/
                hcn->table[hcn->cur].old=hcn->table[prev].old+1;
@@ -228,8 +249,9 @@ u_int32_t convert_ack(struct hcon *hcn, __be32 num, struct hcon *o_hcn)
                }
        }
 
-       dbgprintf(1, "Error: Address Not Found! looking for: %X. Using highest ACK, %i, instead\n", num, o_hcn->high_ack);
-return 0;
+       dbgprintf(1, "Error: Sequence Number Not Found! looking for %i. Using highest ACK, %i, instead.\n",
+                                                                                                                                                                               num, o_hcn->high_ack);
+return o_hcn->high_ack;
 }
 
 /* Get size of packet being acked*/
@@ -252,7 +274,7 @@ int acked_packet_size(struct hcon *hcn, __be32 num)
                }
        }
 
-       dbgprintf(1, "Error: Address Not Found! looking for: %X\n", num);
+       dbgprintf(1, "Error: Sequence Number Not Found! looking for %i\n", num);
 return 0;
 }
 

diff --git a/dccp2tcp.c b/dccp2tcp.c
index db9ca53181241d0e9a4461778ee8ed2edacef554..488b6f309201080f412cc607a0c0db6f95be7d09 100644 (file)
--- a/dccp2tcp.c
+++ b/dccp2tcp.c
@@ -248,8 +248,8 @@ int convert_packet(struct packet *new, const struct const_packet* old)
        }
 
        /*Get Hosts*/
-       if(get_host(new->src_id, new->dest_id, new->id_len,
-                       dccph->dccph_sport, dccph->dccph_dport, &h1, &h2)){
+       if(get_host(new->src_id, new->dest_id, new->id_len, dccph->dccph_sport,
+                       dccph->dccph_dport, dccph->dccph_type,&h1, &h2)){
                dbgprintf(0,"Error: Can't Get Hosts!\n");
                return 0;
        }
@@ -257,6 +257,11 @@ int convert_packet(struct packet *new, const struct const_packet* old)
                dbgprintf(0, "Error: Can't Get Hosts!\n");
                return 0;
        }
+       if(h1->state==IGNORE || h2->state==IGNORE){
+               dbgprintf(2, "Ignoring packet between %i and %i\n",
+                                               ntohs(dccph->dccph_sport), ntohs(dccph->dccph_dport));
+               return 0;
+       }
 
        /*set TCP standard features*/
        tcph->source=dccph->dccph_sport;
@@ -954,12 +959,20 @@ int parse_options(const u_char* opt_start, int len, struct hcon* A, struct hcon*
 
                /*Ack Vector Option*/
                if(*opt==38 || *opt==39){
-
+                       if(B->type==UNKNOWN){
+                               B->type=CCID2;
+                               dbgprintf(1,"Half-connection from port %i to %i probably using CCID 2\n",
+                                                                                       ntohs(B->port),ntohs(A->port));
+                       }
                }
 
                /*NDP Count Option*/
                if(*opt==37){
-
+                       if(B->type==UNKNOWN){
+                               B->type=CCID3;
+                               dbgprintf(1,"Half-connection from port %i to %i probably using CCID 3\n",
+                                                                                       ntohs(B->port),ntohs(A->port));
+                       }
                }
 
                /*Feature negotation*/
@@ -1005,7 +1018,7 @@ int process_feature(const u_char* feat, int len, int confirm, int L, struct hcon
        switch(*feat){
                case 1:
                        /*CCID*/
-                       if(confirm==FALSE){
+                       if(confirm==TRUE){
                                switch(*val){
                                        case 2:
                                                ccid=CCID2;
@@ -1019,16 +1032,24 @@ int process_feature(const u_char* feat, int len, int confirm, int L, struct hcon
                                }
                                if(L==TRUE){
                                        B->type=ccid;
+                                       dbgprintf(1,"Half-connection from port %i to %i using CCID %i\n",
+                                                       ntohs(B->port),ntohs(A->port), *val);
                                }else{
                                        A->type=ccid;
+                                       dbgprintf(1,"Half-connection from port %i to %i using CCID %i\n",
+                                                       ntohs(A->port),ntohs(B->port), *val);
                                }
                        }
                        break;
                case 2:
                        /*Short sequence nums*/
-                       if(confirm==FALSE && *val==1){
-                               dbgprintf(0,"Error! DCCP is trying to turn on short sequence numbers! We do not support this!!\n");
-                               exit(1);
+                       if(confirm==TRUE && *val==1){
+                               B->type=IGNORE;
+                               A->type=IGNORE;
+                               dbgprintf(0,"Error: DCCP is trying to turn on short sequence numbers\n"
+                                               "  for the connection between %i and %i. We do not support this.\n"
+                                               "  This connection will be ignored.",ntohs(A->port),ntohs(B->port));
+                               return 0;
                        }
                        break;
        }
@@ -1157,9 +1178,11 @@ return;
 
 void version()
 {
-       dbgprintf(0, "dccp2tcp version %.1f\nCopyright (C) %i Samuel Jero <sj323707@ohio.edu>\n", DCCP2TCP_VERSION,COPYRIGHT_YEAR);
+       dbgprintf(0, "dccp2tcp version %.1f\n",DCCP2TCP_VERSION);
+       dbgprintf(0, "Copyright (C) %i Samuel Jero <sj323707@ohio.edu>\n",COPYRIGHT_YEAR);
        dbgprintf(0, "This program comes with ABSOLUTELY NO WARRANTY.\n");
-       dbgprintf(0, "This is free software, and you are welcome to\nredistribute it under certain conditions.\n");
+       dbgprintf(0, "This is free software, and you are welcome to\n");
+       dbgprintf(0, "redistribute it under certain conditions.\n");
        exit(0);
 }
 

diff --git a/dccp2tcp.h b/dccp2tcp.h
index dafaeac8158b442a0179ad5f69f7d4b8de455988..3a071a6c8446ca5061b829844f38e810bd061673 100644 (file)
--- a/dccp2tcp.h
+++ b/dccp2tcp.h
@@ -84,6 +84,8 @@ enum con_state{
        INIT,
        OPEN,
        CLOSE,
+       DEAD,
+       IGNORE,
 };
 
 /*Connection Types (i.e. CCID)*/
@@ -142,7 +144,7 @@ int do_encap(int link, struct packet *new, const struct const_packet *old);
 
 /*Connection functions*/
 int get_host(u_char *src_id, u_char* dest_id, int id_len, int src_port, int dest_port,
-               struct hcon **fwd, struct hcon **rev);
+               int pkt_type, struct hcon **fwd, struct hcon **rev);
 struct connection *add_connection(u_char *src_id, u_char* dest_id, int id_len,
                int src_port, int dest_port);
 int update_state(struct hcon* hst, enum con_state st);