sjero.net Git - dccp2tcp/blob - connections.c

   1 /******************************************************************************
   2 Author: Samuel Jero
   3
   4 Date: 7/2011
   5
   6 Description: Functions for differentiating different DCCP connections.
   7
   8 ******************************************************************************/
   9 #include "dccp2tcp.h"
  10
  11 /*Lookup a connection. If it doesn't exist, add a new connection and return it.*/
  12 int get_host(uint32_t src_id, uint32_t dest_id, int src_port, int dest_port, struct host **fwd, struct host **rev){
  13         struct connection *ptr;
  14
  15         /*Empty list*/
  16         if(chead==NULL){
  17                 if(add_connection(src_id, dest_id, src_port, dest_port)==NULL){
  18                         return 1;
  19                 }
  20                 *fwd=&chead->A;
  21                 *rev=&chead->B;
  22                 return 0;
  23         }
  24
  25         /*Loop list looking for connection*/
  26         ptr=chead;
  27         while(ptr!=NULL){
  28                 if(ptr->A.id==src_id && ptr->A.port==src_port &&
  29                                 !(ptr->A.state==CLOSE && ptr->B.state==CLOSE)){
  30                         *fwd=&ptr->A;
  31                         *rev=&ptr->B;
  32                         return 0;
  33                 }
  34                 if(ptr->B.id==src_id && ptr->B.port==src_port &&
  35                                 !(ptr->B.state==CLOSE && ptr->A.state==CLOSE)){
  36                         *fwd=&ptr->B;
  37                         *rev=&ptr->A;
  38                         return 0;
  39                 }
  40                 ptr=ptr->next;
  41         }
  42
  43         /*Add new connection*/
  44         ptr=add_connection(src_id, dest_id, src_port, dest_port);
  45         if(ptr==NULL){
  46                 return 1;
  47         }
  48         *fwd=&ptr->A;
  49         *rev=&ptr->B;
  50         return 0;
  51 }
  52
  53 /*Add a connection. Return it. On failure, return NULL*/
  54 struct connection *add_connection(uint32_t src_id, uint32_t dest_id, int src_port, int dest_port){
  55         struct connection *ptr;
  56         struct connection *prev;
  57
  58         /*Allocate memory*/
  59         if(chead==NULL){
  60                 ptr=chead=malloc(sizeof(struct connection));
  61         }else{
  62                 ptr=chead;
  63                 prev=chead;
  64                 while(ptr!=NULL){
  65                         prev=ptr;
  66                         ptr=ptr->next;
  67                 }
  68                 ptr=prev->next=malloc(sizeof(struct connection));
  69         }
  70
  71         if(ptr==NULL){
  72                 dbgprintf(0,"Error: Couldn't allocate Memory\n");
  73                 exit(1);
  74         }
  75
  76         /*Initialize*/
  77         ptr->A.id=src_id;
  78         ptr->A.port=src_port;
  79         ptr->A.state=INIT;
  80         ptr->B.id=dest_id;
  81         ptr->B.port=dest_port;
  82         ptr->B.state=INIT;
  83
  84         return ptr;
  85 }
  86
  87 /*Update the state on a host*/
  88 int update_state(struct host* hst, enum con_state st){
  89         if(!hst){
  90                 return 1;
  91         }
  92         hst->state=st;
  93         return 0;
  94 }
  95
  96 /*Free all connections*/
  97 void cleanup_connections(){
  98         struct connection *ptr;
  99         struct connection *prev;
 100         prev=ptr=chead;
 101
 102         while(ptr!=NULL){
 103                 prev=ptr;
 104                 ptr=ptr->next;
 105                 free(prev);
 106         }
 107 return;
 108 }