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 && ptr->A.state!=CLOSE){
  29                         fwd=&ptr->A;
  30                         rev=&ptr->B;
  31                         return 0;
  32                 }
  33                 if(ptr->B.id==src_id && ptr->B.port==src_port && ptr->B.state!=CLOSE){
  34                         fwd=&ptr->B;
  35                         rev=&ptr->A;
  36                         return 0;
  37                 }
  38                 ptr=ptr->next;
  39         }
  40
  41         /*Add new connection*/
  42         ptr=add_connection(src_id, dest_id, src_port, dest_port);
  43         if(ptr==NULL){
  44                 return 1;
  45         }
  46         fwd=&ptr->A;
  47         rev=&ptr->B;
  48         return 0;
  49 }
  50
  51 /*Add a connection. Return it. On failure, return NULL*/
  52 struct connection *add_connection(uint32_t src_id, uint32_t dest_id, int src_port, int dest_port){
  53         struct connection *ptr;
  54         struct connection *prev;
  55
  56         /*Allocate memory*/
  57         if(chead){
  58                 ptr=chead=malloc(sizeof(struct connection));
  59         }else{
  60                 ptr=chead;
  61                 prev=chead;
  62                 while(ptr!=NULL){
  63                         prev=ptr;
  64                         ptr=ptr->next;
  65                 }
  66                 ptr=prev->next=malloc(sizeof(struct connection));
  67         }
  68
  69         if(ptr==NULL){
  70                 dbgprintf(0,"Error: Couldn't allocate Memory\n");
  71                 exit(1);
  72         }
  73
  74         /*Initialize*/
  75         ptr->A.id=src_id;
  76         ptr->A.state=INIT;
  77         ptr->B.id=dest_id;
  78         ptr->B.port=dest_port;
  79         ptr->B.state=INIT;
  80
  81         return ptr;
  82 }
  83
  84 /*Update the state on a host*/
  85 int update_state(struct host* hst, enum con_state st){
  86         if(!hst){
  87                 return 1;
  88         }
  89         hst->state=st;
  90         return 0;
  91 }