#include "mfapi.h"  /* Milter-API  */
#include <stdio.h>  /* for fprintf */
#include <unistd.h> /* for getopt  */

/* Cleanup function */
extern sfsistat mlfi_cleanup(SMFICTX *, sfsistat);

/* End of message callback */
sfsistat mlfi_eom(SMFICTX *ctx)
{
        /* Remove Header, ignore any errors */
        smfi_chgheader(ctx, "Disposition-Notification-To", 1, NULL);

        /* Continue processing, accept mail in any case. */
        return mlfi_cleanup(ctx, SMFIS_ACCEPT);
}

/* Do cleanup, if any. */
sfsistat mlfi_cleanup(SMFICTX *ctx, sfsistat rc)
{
        return(rc);
}

/* Milter control block (1st three entries) and function table */
struct smfiDesc smfilter =
{
        "HeaderBuster",     /* filter name               */
        SMFI_VERSION,       /* version code              */
        SMFIF_CHGHDRS,      /* flags                     */
        NULL,               /* connection info filter    */
        NULL,               /* SMTP HELO command filter  */
        NULL,               /* envelope sender filter    */
        NULL,               /* envelope recipient filter */
        NULL,               /* header filter             */
        NULL,               /* end of header             */
        NULL,               /* body block filter         */
        mlfi_eom,           /* end of message            */
        NULL,               /* message aborted           */
        NULL                /* connection cleanup        */
};

int main(int argc, char *argv[])
{
    int c;
    const char *args = "p:";

    /* Process command line options */
    while ((c = getopt(argc, argv, args)) != -1) {
        switch (c) {
        case 'p':
            if (optarg == NULL || *optarg == '\0') {
                fprintf(stderr, "Illegal connection string: %s\n", optarg);
                exit(0);
            }

            /* Set the protocol */

            smfi_setconn(optarg);
            break;

        }
    }

    /* Register callbacks */
    if (smfi_register(smfilter) == MI_FAILURE) {
        fprintf(stderr, "smfi_register failed\n");
        exit(-1);
    }

    /* Become background process and hand over control 
     * to milter by calling smfi_main() 
     */
    if (fork() == 0) {
        return smfi_main();
    }

    /* Parent process exit */
    return 0;
}