#include "str.h"
#include "scan.h"
#include "env.h"
#include "exit.h"
#include "sgetopt.h"
#include "strerr.h"
#include "stralloc.h"
#include "pathexec.h"
#include "dns.h"

#define FATAL "rblqmtpd: fatal: "

void nomem(void)
{
  strerr_die2x(111,FATAL,"out of memory");
}
void usage(void)
{
  strerr_die1x(100,"rblqmtpd: usage: rblqmtpd [ -r base ] [ -a base ] qmtpd [ arg ... ]");
}

char *ip_env;
static stralloc ip_reverse;

void ip_init(void)
{
  unsigned int i;
  unsigned int j;

  ip_env = env_get("TCPREMOTEIP");
  if (!ip_env) ip_env = "";

  if (!stralloc_copys(&ip_reverse,"")) nomem();

  i = str_len(ip_env);
  while (i) {
    for (j = i;j > 0;--j) if (ip_env[j - 1] == '.') break;
    if (!stralloc_catb(&ip_reverse,ip_env + j,i - j)) nomem();
    if (!stralloc_cats(&ip_reverse,".")) nomem();
    if (!j) break;
    i = j - 1;
  }
}

int decision = 0; /* 0 undecided, 1 accept, 2 reject */
static stralloc text; /* defined if decision is 2 */

static stralloc tmp;

void rbl(char *base)
{
  if (decision) return;
  if (!stralloc_copy(&tmp,&ip_reverse)) nomem();
  if (!stralloc_cats(&tmp,base)) nomem();
  if (dns_txt(&text,&tmp) == -1) {
    decision = 2;
    return;
  }
  if (text.len) decision = 2;
}

void antirbl(char *base)
{
  if (decision) return;
  if (!stralloc_copy(&tmp,&ip_reverse)) nomem();
  if (!stralloc_cats(&tmp,base)) nomem();
  if (dns_ip4(&text,&tmp) == -1) {
    decision = 1;
    return;
  }
  if (text.len) decision = 1;
}

void rblqmtpd(void)
{
  _exit(0);			/* drastic times call for drastic measures */
				/* optionally, you could strerr_die here */
}

main(int argc,char **argv,char **envp)
{
  int flagwantdefaultrbl = 1;
  char *x;
  int opt;

  ip_init();

  x = env_get("RBLQMTPD");
  if (x) {
    if (!*x)
      decision = 1;
    else if (*x == '-') decision = 3;
    else decision = 2;
  }

  while ((opt = getopt(argc,argv,"r:a:")) != opteof)
    switch(opt) {
      case 'r': rbl(optarg); flagwantdefaultrbl = 0; break;
      case 'a': antirbl(optarg); break;
      default: usage();
    }

  argv += optind;
  if (!*argv) usage();

  if (flagwantdefaultrbl) rbl("rbl.maps.vix.com");
  if (decision >= 2) rblqmtpd();

  pathexec_run(*argv,argv,envp);
  strerr_die4sys(111,FATAL,"unable to run ",*argv,": ");
}