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

   1 /******************************************************************************
   2 Author: Samuel Jero
   3
   4 Date: 11/2012
   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(u_char *src_id, u_char* dest_id, int id_len, int src_port, int dest_port,
  13                 struct host **fwd, struct host **rev){
  14         struct connection *ptr;
  15
  16         /*Empty list*/
  17         if(chead==NULL){
  18                 if(add_connection(src_id, dest_id, id_len, src_port, dest_port)==NULL){
  19                         return 1;
  20                 }
  21                 *fwd=&chead->A;
  22                 *rev=&chead->B;
  23                 return 0;
  24         }
  25
  26         /*Loop list looking for connection*/
  27         ptr=chead;
  28         while(ptr!=NULL){
  29                 if(memcmp(ptr->A.id,src_id,id_len)==0 && ptr->A.port==src_port &&
  30                                 !(ptr->A.state==CLOSE && ptr->B.state==CLOSE)){
  31                         *fwd=&ptr->A;
  32                         *rev=&ptr->B;
  33                         return 0;
  34                 }
  35                 if(memcmp(ptr->B.id,src_id,id_len)==0 && ptr->B.port==src_port &&
  36                                 !(ptr->B.state==CLOSE && ptr->A.state==CLOSE)){
  37                         *fwd=&ptr->B;
  38                         *rev=&ptr->A;
  39                         return 0;
  40                 }
  41                 ptr=ptr->next;
  42         }
  43
  44         /*Add new connection*/
  45         ptr=add_connection(src_id, dest_id, id_len, src_port, dest_port);
  46         if(ptr==NULL){
  47                 return 1;
  48         }
  49         *fwd=&ptr->A;
  50         *rev=&ptr->B;
  51         return 0;
  52 }
  53
  54 /*Add a connection. Return it. On failure, return NULL*/
  55 struct connection *add_connection(u_char *src_id, u_char* dest_id, int id_len, int src_port, int dest_port){
  56         struct connection *ptr;
  57         struct connection *prev;
  58
  59         /*Allocate memory*/
  60         if(chead==NULL){
  61                 ptr=chead=malloc(sizeof(struct connection));
  62         }else{
  63                 ptr=chead;
  64                 prev=chead;
  65                 while(ptr!=NULL){
  66                         prev=ptr;
  67                         ptr=ptr->next;
  68                 }
  69                 ptr=prev->next=malloc(sizeof(struct connection));
  70         }
  71
  72         if(ptr==NULL){
  73                 dbgprintf(0,"Error: Couldn't allocate Memory\n");
  74                 exit(1);
  75         }
  76
  77         /*Initialize*/
  78         ptr->A.id=malloc(id_len);
  79         ptr->B.id=malloc(id_len);
  80         if(ptr->A.id==NULL||ptr->B.id==NULL){
  81                 dbgprintf(0,"Error: Couldn't allocate Memory\n");
  82                 exit(1);
  83         }
  84         memcpy(ptr->A.id,src_id,id_len);
  85         ptr->A.port=src_port;
  86         ptr->A.state=INIT;
  87         memcpy(ptr->B.id,dest_id,id_len);
  88         ptr->B.port=dest_port;
  89         ptr->B.state=INIT;
  90
  91         return ptr;
  92 }
  93
  94 /*Update the state on a host*/
  95 int update_state(struct host* hst, enum con_state st){
  96         if(!hst){
  97                 return 1;
  98         }
  99         hst->state=st;
 100         return 0;
 101 }
 102
 103 /*Free all connections*/
 104 void cleanup_connections(){
 105         struct connection *ptr;
 106         struct connection *prev;
 107         prev=ptr=chead;
 108
 109         while(ptr!=NULL){
 110                 prev=ptr;
 111                 free(ptr->A.id);
 112                 free(ptr->B.id);
 113                 ptr=ptr->next;
 114                 free(prev);
 115         }
 116 return;
 117 }