git.sip-router.org Git - sip-router/blob - forward.c

   1 /*
   2  * $Id$
   3  */
   4
   5
   6 #include <string.h>
   7 #include <sys/types.h>
   8 #include <sys/socket.h>
   9 #include <netdb.h>
  10 #include <netinet/in.h>
  11 #include <arpa/inet.h>
  12
  13 #include "forward.h"
  14 #include "config.h"
  15 #include "msg_parser.h"
  16 #include "route.h"
  17 #include "dprint.h"
  18 #include "udp_server.h"
  19 #include "globals.h"
  20
  21 #define MAX_VIA_LINE_SIZE      240
  22 #define MAX_RECEIVED_SIZE  57
  23
  24
  25
  26 /* checks if ip is in host(name) and ?host(ip)=name?
  27  * ip must be in network byte order!
  28  *  resolver = DO_DNS | DO_REV_DNS; if 0 no dns check is made
  29  * return 0 if equal */
  30 int check_address(unsigned long ip, char *name, int resolver)
  31 {
  32         struct hostent* he;
  33         int i;
  34
  35         /* maybe we are lucky and name it's an ip */
  36         if (strcmp(name, inet_ntoa( *(struct in_addr *)&ip ))==0)
  37                 return 0;
  38         if (resolver&DO_DNS){
  39                 /* try all names ips */
  40                 he=gethostbyname(name);
  41                 for(i=0; he->h_addr_list[i];i++){
  42                         if (*(unsigned long*)he->h_addr_list[i]==ip)
  43                                 return 0;
  44                 }
  45         }
  46         if (resolver&DO_REV_DNS){
  47                 /* try reverse dns */
  48                 he=gethostbyaddr((char*)&ip, sizeof(ip), AF_INET);
  49                 if (strcmp(he->h_name, name)==0)
  50                         return 0;
  51                 for (i=0; he->h_aliases[i];i++){
  52                         if (strcmp(he->h_aliases[i],name)==0)
  53                                 return 0;
  54                 }
  55         }
  56         return -1;
  57 }
  58
  59
  60
  61 int forward_request(char * orig, char* buf,
  62                                          unsigned int len,
  63                                          struct sip_msg* msg,
  64                                          struct route_elem* re,
  65                                          unsigned long source_ip)
  66 {
  67         unsigned int new_len, via_len, received_len;
  68         char line_buf[MAX_VIA_LINE_SIZE];
  69         char received_buf[MAX_RECEIVED_SIZE];
  70         char* new_buf;
  71         int offset, s_offset, size;
  72         struct sockaddr_in to;
  73
  74         received_len=0;
  75
  76         via_len=snprintf(line_buf, MAX_VIA_LINE_SIZE, "Via: SIP/2.0/UDP %s:%d\r\n",
  77                                                 names[0], port_no);
  78         /* check if received needs to be added */
  79         if (check_address(source_ip, msg->via1.host, received_dns)!=0){
  80                 received_len=snprintf(received_buf, MAX_RECEIVED_SIZE,
  81                                                                 ";received=%s",
  82                                                                 inet_ntoa(*(struct in_addr *)&source_ip));
  83         }
  84
  85         new_len=len+via_len+received_len;
  86         new_buf=(char*)malloc(new_len+1);
  87         if (new_buf==0){
  88                 DPrint("ERROR: forward_request: out of memory\n");
  89                 goto error1;
  90         }
  91 /* copy msg till first via */
  92         offset=s_offset=0;
  93         size=msg->via1.hdr-buf;
  94         memcpy(new_buf, orig, size);
  95         offset+=size;
  96         s_offset+=size;
  97  /* add our via */
  98         memcpy(new_buf+offset, line_buf, via_len);
  99         offset+=via_len;
 100  /* modify original via if neccesarry (received=...)*/
 101         if (received_len){
 102                 if (msg->via1.params){
 103                                 size= msg->via1.params-msg->via1.hdr-1; /*compensate for ';' */
 104                 }else{
 105                                 size= msg->via1.host-msg->via1.hdr+strlen(msg->via1.host);
 106                                 if (msg->via1.port!=0){
 107                                         size+=strlen(msg->via1.hdr+size+1)+1; /* +1 for ':'*/
 108                                 }
 109                 }
 110                 memcpy(new_buf+offset, orig+s_offset,
 111                                                                 size);
 112                 offset+=size;
 113                 s_offset+=size;
 114                 memcpy(new_buf+offset, received_buf, received_len);
 115                 offset+=received_len;
 116         }
 117         /* copy the rest of the msg */
 118         memcpy(new_buf+offset, orig+s_offset, len-s_offset);
 119         new_buf[new_len]=0;
 120
 121          /* send it! */
 122         printf("Sending:\n%s.\n", new_buf);
 123         printf("orig. len=%d, new_len=%d, via_len=%d, received_len=%d\n",
 124                         len, new_len, via_len, received_len);
 125
 126         to.sin_family = AF_INET;
 127         to.sin_port = (re->port)?htons(re->port):htons(SIP_PORT);
 128         /* if error try next ip address if possible */
 129         if (re->ok==0){
 130                 if (re->host.h_addr_list[re->current_addr_idx+1])
 131                         re->current_addr_idx++;
 132                 re->ok=1;
 133         }
 134         /* ? not 64bit clean?*/
 135         to.sin_addr.s_addr=*((long*)re->host.h_addr_list[re->current_addr_idx]);
 136
 137         re->tx++;
 138         re->tx_bytes+=new_len;
 139         if (udp_send(new_buf, new_len, &to, sizeof(to))==-1){
 140                         re->errors++;
 141                         re->ok=0;
 142                         goto error;
 143         }
 144
 145         free(new_buf);
 146         return 0;
 147 error:
 148         free(new_buf);
 149 error1:
 150         return -1;
 151
 152 }
 153
 154
 155
 156 /* removes first via & sends msg to the second */
 157 int forward_reply(char * orig, char* buf,
 158                                          unsigned int len,
 159                                          struct sip_msg* msg)
 160 {
 161
 162
 163         unsigned int new_len, via_len,r;
 164         char* new_buf;
 165         int offset, s_offset, size;
 166         struct hostent* he;
 167         struct sockaddr_in to;
 168
 169         new_buf=0;
 170
 171         /*check if first via host = us */
 172         if (check_via){
 173                 for (r=0; r<addresses_no; r++)
 174                         if(strcmp(msg->via1.host, names[r])==0) break;
 175                 if (r==addresses_no){
 176                         DPrint("ERROR: forward_reply: host in first via != me : %s\n",
 177                                         msg->via1.host);
 178                         /* send error msg back? */
 179                         goto error;
 180                 }
 181         }
 182         /* we must remove the first via */
 183         via_len=msg->via1.size;
 184         size=msg->via1.hdr-buf;
 185         if (msg->via1.next){
 186                 /* keep hdr =substract hdr size +1 (hdr':') and add
 187                  */
 188                 via_len-=strlen(msg->via1.hdr)+1;
 189                 size+=strlen(msg->via1.hdr)+1;
 190         }
 191         new_len=len-size;
 192         new_buf=(char*)malloc(new_len);
 193         if (new_buf==0){
 194                 DPrint("ERROR: forward_reply: out of memory\n");
 195                 goto error;
 196         }
 197         memcpy(new_buf, orig, size);
 198         offset=size;
 199         s_offset=size+via_len;
 200         memcpy(new_buf+offset,orig+s_offset, len-s_offset);
 201          /* send it! */
 202         printf("Sending: to %s:%d, \n%s.\n",
 203                         msg->via2.host,
 204                         (unsigned short)msg->via2.port,
 205                         new_buf);
 206         /* fork? gethostbyname will probably block... */
 207         he=gethostbyname(msg->via2.host);
 208         if (he==0){
 209                 DPrint("ERROR:forward_reply:gethostbyname failure\n");
 210                 goto error;
 211         }
 212         to.sin_family = AF_INET;
 213         to.sin_port = (msg->via2.port)?htons(msg->via2.port):htons(SIP_PORT);
 214         to.sin_addr.s_addr=*((long*)he->h_addr_list[0]);
 215
 216         if (udp_send(new_buf,new_len, &to, sizeof(to))==-1)
 217                 goto error;
 218
 219         free(new_buf);
 220         return 0;
 221
 222 error:
 223         if (new_buf) free(new_buf);
 224         return -1;
 225 }