#include <stdio.h>
#include <stdlib.h>
#include <string.h>

char*geofile="/usr/share/ip-geo.ids";
char*ctrycodefile="/usr/share/country-codes.txt";

int showctry=1;
int showcode=0;
int showip=0;
int showrange=0;
int showmatches=0;
int showeol=1;


char matchrange[64]="";

unsigned long str2ip(char*s)
{ char*sp,*sp1,*sp2;
  int n1,n2,n3,n4;
  sp=strchr(s,'.');if(!sp)return 0;sp++;
  sp1=strchr(sp,'.');if(!sp1)return 0;sp1++;
  sp2=strchr(sp1,'.');if(!sp2)return 0;sp2++;
  n1=atoi(s);n2=atoi(sp);n3=atoi(sp1);n4=atoi(sp2);
  return (n1<<24)+(n2<<16)+(n3<<8)+n4;
}

unsigned long str2mask(int n)
{ unsigned long l=0;
  while(n>0){l>>=1;l|=0x80000000;n--;}
  return l;
}

int maskmatch(long ip,long ip2,int mask)
{ unsigned long m;
  m=str2mask(mask);
  return (ip&m) == (ip2&m);
}

char*code2loc(char*code)
{ FILE*f;
  static char s[256]="",*sp,*sp1;
  f=fopen(ctrycodefile,"r");if(!f)return "[Cannot open countrycode file.]";
  while(!feof(f)){
   s[0]=0;fgets(s,255,f);if(s[0]=='#')continue;
   sp=strchr(s,' ');if(!sp)continue;sp[0]=0;sp++;while(sp[0]==' ')sp++;
   if(strcasecmp(code,s))continue;
   fclose(f);sp1=strchr(sp,'\n');if(sp1)sp1[0]=0;return sp;
  }
  fclose(f);return "(No match.)";
}

void printcountry(char*ip,char*code,char*range)
{ char*sp;
  if(showip)printf("%s\t",ip);
  if(showrange)printf("%s\t",range);
  if(showctry){if(showcode)printf("%s",code);
                      else printf("%s",code2loc(code));}
  if(showeol)printf("\n");
}

char*ip2code(char*ipstr)
{ long xip,ip;
  int mask;
  char*code,*sp;
  char s[256]="";
  static char lastmatch[256]="";
  int lastmatchmask=0;
  FILE*f;
  strcpy(lastmatch,"");
  if(!ipstr)return "??";
  f=fopen(geofile,"r");if(!f)return "[Cannot open ip-geo.ids file.]";
  xip=str2ip(ipstr);if(xip==0)return "??";
  while(!feof(f)){
   s[0]=0;fgets(s,255,f);
   if(s[0]=='#')continue;
   sp=strchr(s,' ');if(!sp)continue;sp++;code=sp;
   sp=strchr(s,'/');if(!sp)continue;sp++;mask=atoi(sp);
   ip=str2ip(s);
   if(maskmatch(xip,ip,mask))
    {if(mask>lastmatchmask)
     {strcpy(lastmatch,s);lastmatchmask=mask;}
     if(showmatches)
      {sp=strchr(s,'\n');if(sp)sp[0]=0;
       sp=strchr(s,' ');if(sp){sp[0]=0;sp++;while(sp[0]==' ')sp++;}
       printcountry(ipstr,sp,s);
      }
    }
  }
  fclose(f);
  strncpy(matchrange,lastmatch,63);matchrange[63]=0;
  sp=strchr(matchrange,' ');if(sp)sp[0]=0;
  sp=strchr(lastmatch,'\n');if(sp)sp[0]=0;
  sp=strchr(lastmatch,' ');if(!sp)return "??";sp++;
  while(sp[0]==' ')sp++;
  return sp;
}

void showcountryranges(char*code)
{ FILE*f;
  char s[256],*sp;
  f=fopen(geofile,"r");if(!f){printf("[Cannot open ip-geo.ids file.]\n");return;}
  while(!feof(f)){
   s[0]=0;fgets(s,255,f);
   if(s[0]=='#')continue;
   sp=strchr(s,'\n');if(sp)sp[0]=0;
   sp=strchr(s,' ');if(!sp)continue;sp[0]=0;sp++;while(sp[0]==' ')sp++;
   if(strcasecmp(code,sp))continue;
   printf("%s\n",s);
  }
  fclose(f);
}

void showcountry(char*ip)
{ char*code,*sp;
  sp=strchr(ip,'\n');if(sp)sp[0]=0;
  matchrange[0]=0;
  code=ip2code(ip);
  if(!showmatches)printcountry(ip,code,matchrange);
}

void showcountrylist()
{ char s[256];
  while(!feof(stdin))
  {s[0]=0;fgets(s,255,stdin);
   if(s[0]=='\n')continue;
   if(s[0]=='#')continue;
   if(!s[0])continue;
   showcountry(s);
  }
}

void help()
{ printf(
"Usage: ip2loc [-i] [-c] IP ...\n"
"       ip2loc country_code\n"
"Shows countries or country codes for IP addresses.\n"
"\n"
"Options:\n"
"   -i          show IP\n"
"   -c          show country as code instead as name\n"
"   -C          do not show country\n"
"   -r          show IP range\n"
"   -m          show all matching ranges\n"
"   -n          do not show trailing \\n\n"
"   -L <code>   show country code <code>\n"
"   -R <code>   show IP ranges for country <code>\n"
"   -G <file>   use <file> as geolocation file instead of %s\n"
"\n"
"When IP is '-', the addresses are read from stdin.\n"
,geofile);
}

int main(int argc,char*argv[])
{ char*ip;
  char*code;
  int t;
  if(argc==2)if(isalpha(argv[1][0])){printf("%s\n",code2loc(argv[1]));return 0;}
  for(t=1;t<argc;t++)
  { if(!strcmp(argv[t],"-c")){showcode=1;continue;}
    if(!strcmp(argv[t],"-C")){showctry=0;continue;}
    if(!strcmp(argv[t],"-i")){showip=1;continue;}
    if(!strcmp(argv[t],"-r")){showrange=1;continue;}
    if(!strcmp(argv[t],"-m")){showmatches=1;continue;}
    if(!strcmp(argv[t],"-n")){showeol=0;continue;}
    if(!strcmp(argv[t],"-L")){t++;printf("%s\n",code2loc(argv[t]));continue;}
    if(!strcmp(argv[t],"-R")){t++;showcountryranges(argv[t]);continue;}
    if(!strcmp(argv[t],"-G")){t++;geofile=argv[t];continue;}
    if(!strcmp(argv[t],"-?")){help();break;}
    if(!strcasecmp(argv[t],"-h")){help();break;}
    if(!strcasecmp(argv[t],"--help")){help();break;}
    if(isdigit(argv[t][0])){showcountry(argv[t]);continue;}
    if(!strcmp(argv[t],"-")){showcountrylist();continue;}
    printf("Error: Unknown option: %s\n",argv[t]);
    break;
  }
  return 0;
}