/*
 * badrcptto plugin for qmail-spp
 * 
 * Reject mails if recipient address is listed in  
 * CONTROL/badrcptto. addresses can be a lead part 
 * of it, ignore case, and compared with its length.
 *
 * compile: gcc badrcptto.c -o badrcptto
 * license: public domain
 *
 * Hiroshi Tsukamoto [ h1r.org ]
 * 
 */

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

#define BRTFILE "/var/qmail/control/badrcptto"

#define logmsg(s) fputs("badrcptto: " s, stderr)

#define BUFSIZE 1024
#define MIN_LEN 3

static char *id = "$Id: badrcptto.c,v 1.7 2006/05/10 09:28:29 hirobo Exp $";

int 
checkbmf(char *addr) {
  FILE *fp;
  static char buff[BUFSIZE];
  size_t rcptlen, bmflen;
  int retval;

  retval = 1;
  if ((fp = fopen(BRTFILE, "r")) == NULL) {
    logmsg("file badrcptto not found\n");
    return -1;
  }

  if ((rcptlen = strlen(addr)) >= BUFSIZE) {
    logmsg("too long RCPTTO\n");
    return -1;
  }

  if (rcptlen == 0) {
    logmsg("no RCPTTO\n");
    return -1;
  }

  while(fgets(buff, BUFSIZE - 1, fp)) {
    /* skip blank line and too short badrcptto strings */
    if ((bmflen = strlen(buff) - 1) < MIN_LEN) continue;
    /* skip comment */
    if (buff[0] == '#') continue;          
    if (bmflen > rcptlen) continue;
    if (!strncasecmp(addr, buff, bmflen)) {
      retval = 0;
      break;
    }
  }
  fclose(fp);
  return retval;
}

int 
main (int argc, char **argv) {
  char *rcpt;

  if (getenv("RELAYCLIENT")) exit(0);

  if (!(rcpt = getenv("SMTPRCPTTO"))) {
    logmsg("Error - can not read SMTPRCPTTO\n");
    exit(0);
  }
  if (!checkbmf(rcpt)) {
    puts("E550 Requested action not taken: mailbox unavailable (#5.1.1)");
    fprintf(stderr, "badrcptto: [%s] RCPT=%s SENDER=%s\n",
	    getenv("TCPREMOTEIP"), rcpt, getenv("SMTPMAILFROM"));
  }
  exit(0);
}