/*
**  OSSP lmtp2nntp - Mail to News Gateway
**  Copyright (c) 2001-2003 Ralf S. Engelschall <rse@engelschall.com>
**  Copyright (c) 2001-2003 The OSSP Project <http://www.ossp.org/>
**  Copyright (c) 2001-2003 Cable & Wireless Germany <http://www.cw.com/de/>
**
**  This file is part of OSSP lmtp2nntp, an LMTP speaking local
**  mailer which forwards mails as Usenet news articles via NNTP.
**  It can be found at http://www.ossp.org/pkg/tool/lmtp2nntp/.
**
**  This program is free software; you can redistribute it and/or
**  modify it under the terms of the GNU General Public  License
**  as published by the Free Software Foundation; either version
**  2.0 of the License, or (at your option) any later version.
**
**  This program is distributed in the hope that it will be useful,
**  but WITHOUT ANY WARRANTY; without even the implied warranty of
**  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
**  General Public License for more details.
**
**  You should have received a copy of the GNU General Public License
**  along with this file; if not, write to the Free Software
**  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
**  USA, or contact the OSSP project <ossp@ossp.org>.
**
**  lmtp2nntp_main.c: LMTP to NNTP main procedure
*/

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <sys/utsname.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <signal.h>
#include <stdarg.h>

/* third party (included) */
#include "lmtp2nntp_argz.h"
#include "lmtp2nntp_shpat.h"
#include "lmtp2nntp_daemon.h"

/* third party (linked in) */
#include "ex.h"
#include "str.h"
#include "l2.h"
#include "sa.h"
#include "var.h"
#include "val.h"
#include "popt.h"

/* library version check (compile-time) */
#define  L2_VERSION_HEX_REQ 0x001200
#define  L2_VERSION_STR_REQ "0.1.0"
#define STR_VERSION_HEX_REQ 0x009206
#define STR_VERSION_STR_REQ "0.9.6"
#ifdef L2_VERSION_HEX
#if L2_VERSION_HEX < L2_VERSION_HEX_REQ
#error "require a newer version of OSSP L2"
#endif
#endif
#ifdef STR_VERSION_HEX
#if STR_VERSION_HEX < STR_VERSION_HEX_REQ
#error "require a newer version of OSSP Str"
#endif
#endif

/* own headers */
#include "lmtp2nntp_global.h"
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#if defined(HAVE_DMALLOC_H) && defined(WITH_DMALLOC)
#include "dmalloc.h"
#endif
#include "lmtp2nntp_option.h"
#include "lmtp2nntp_config.h"
#include "lmtp2nntp_lmtp.h"
#include "lmtp2nntp_nntp.h"
#include "lmtp2nntp_msg.h"
#include "lmtp2nntp_common.h"
#include "sa.h"
#define _LMTP2NNTP_VERSION_C_AS_HEADER_
#include "lmtp2nntp_version.c"
#undef  _LMTP2NNTP_VERSION_C_AS_HEADER_

#ifndef FALSE
#define FALSE (1 != 1)
#endif
#ifndef TRUE
#define TRUE (!FALSE)
#endif

#ifndef NUL
#define NUL '\0'
#endif

#define STDSTRLEN 512

static lmtp_rc_t lmtp_cb_lhlo(lmtp_t *lmtp, lmtp_io_t *io, lmtp_req_t *req, void *ctx);
static lmtp_rc_t lmtp_cb_mail(lmtp_t *lmtp, lmtp_io_t *io, lmtp_req_t *req, void *ctx);
static lmtp_rc_t lmtp_cb_rcpt(lmtp_t *lmtp, lmtp_io_t *io, lmtp_req_t *req, void *ctx);
static lmtp_rc_t lmtp_cb_data(lmtp_t *lmtp, lmtp_io_t *io, lmtp_req_t *req, void *ctx);
static lmtp_rc_t lmtp_cb_noop(lmtp_t *lmtp, lmtp_io_t *io, lmtp_req_t *req, void *ctx);
static lmtp_rc_t lmtp_cb_rset(lmtp_t *lmtp, lmtp_io_t *io, lmtp_req_t *req, void *ctx);
static lmtp_rc_t lmtp_cb_quit(lmtp_t *lmtp, lmtp_io_t *io, lmtp_req_t *req, void *ctx);

static int helo_rfc0821domain(char *msg, char **domain);
static int helo_rfc1035domain(char *msg, char **domain);

static void catchsignal(int sig, ...);
static void initsession(struct session *session);
static void resetsession(struct session *session);
int groupmatch(char *, size_t, char *);

void logbook(l2_channel_t *ch, l2_level_t level, const char *fmt, ...)
{
    va_list ap;
    l2_channel_t *ch2 = NULL;

    if (strchr(fmt, '$') == NULL) {
        if (l2_channel_downstream(ch, &ch2) != L2_OK)
            return;
        ch = ch2;
    }
    va_start(ap, fmt);
    l2_channel_vlog(ch, level, fmt, ap);
    va_end(ap);
    return;
}

static var_syntax_t syntax_ctx = {
    '\\',         /* escape        */
    '$',          /* varinit       */
    '{',          /* startdelim    */
    '}',          /* enddelim      */
    '[',          /* startindex    */
    ']',          /* endindex      */
    '#',          /* current_index */
    "a-zA-Z0-9.-" /* namechars     */
};

static var_rc_t ctx_lookup(
    var_t *var,
    void *_ctx,
    const char *var_ptr, size_t var_len, int var_idx,
    const char **val_ptr, size_t *val_len, size_t *val_size)
{
    lmtp2nntp_t *ctx = (lmtp2nntp_t *)_ctx;
    var_rc_t rc;
    char *cp;
    optionval_t *ov;

    rc = VAR_ERR_UNDEFINED_VARIABLE;
    if (strncasecmp(var_ptr, "option.", strlen("option.")) == 0) {
        cp = str_dupex(var_ptr, var_len);
        if (val_get(ctx->val, cp, &ov) == VAL_OK) {
            if ((var_idx == 0) && (ov->ndata == 1) && (ov->type == OPT_SINGLE)) { /* request first/only single value */
                *val_ptr = ov->data.s;
                *val_len = strlen(ov->data.s);
                *val_size = 0;
                rc = VAR_OK;
            }
            else if ((var_idx == 0) && (ov->ndata == 1) && (ov->type == OPT_FLAG)) { /* request first/only single value */
                *val_ptr = ov->data.f == TRUE ? "yes" : "no";
                *val_len = strlen(ov->data.s);
                *val_size = 0;
                rc = VAR_OK;
            }
            else if ((var_idx < ov->ndata) && (ov->type == OPT_MULTI)) { /* request second+ from multi value */
                *val_ptr = ov->data.m[var_idx];
                *val_len = strlen(ov->data.m[var_idx]);
                *val_size = 0;
                rc = VAR_OK;
            }
        }
        free(cp);
    }
    else if (   (strncasecmp(var_ptr, "msg.header.", strlen("msg.header.")) == 0)
             && (ctx->msg != NULL)
               ) {
        headerdata_t *hdI;
        int n;
        cp = str_dupex(var_ptr + strlen("msg.header."), var_len - strlen("msg.header.") + 1);
        n = strlen(cp);
        cp[n]= ':';
        cp[n + 1] = NUL;
        for (hdI = ctx->msg->hdFirst; hdI != NULL; hdI = hdI->next) { /* for each header */
            if (hdI->name == NULL || strlen(hdI->name) == 0)
                continue;
            if (strcasecmp(cp, hdI->name) == 0)
                break;
        }
        if (hdI != NULL) {
            if ((var_idx == 0) && (hdI->ndata == 1)) { /* request first/only single value */
                *val_ptr = hdI->data.s;
                *val_len = strlen(hdI->data.s);
                *val_size = 0;
                rc = VAR_OK;
            }
            else if (var_idx < hdI->ndata) { /* request from multi value */
                *val_ptr = hdI->data.m[var_idx];
                *val_len = strlen(hdI->data.m[var_idx]);
                *val_size = 0;
                rc = VAR_OK;
            }
        }
        free(cp);
    }

    return rc;
}

static void lmtp_gfs_ns(struct ns *);
static void lmtp_gfs_lhlo(lmtp2nntp_t *);
static void lmtp_gfs_rset(lmtp2nntp_t *);
static void lmtp_gfs_quit(lmtp2nntp_t *);

static void sa2errno(sa_rc_t rv)
{
    switch (rv) {
        case SA_OK:      errno = 0;      break;
        case SA_ERR_EOF: errno = 0;      break;
        case SA_ERR_SYS:                 break;
        case SA_ERR_ARG: errno = EINVAL; break;
        case SA_ERR_USE: errno = EINVAL; break;
        case SA_ERR_MTC: errno = ENOENT; break;
        case SA_ERR_MEM: errno = ENOMEM; break;
        case SA_ERR_IMP: errno = ENOSYS; break;
        case SA_ERR_TMT: errno = EIO;    break;
        case SA_ERR_NET: errno = EIO;    break;
        case SA_ERR_FMT: errno = EIO;    break;
        case SA_ERR_INT: errno = EIO;    break;
        default:         errno = EIO;
    }
}

static ssize_t hook_lmtp_read(void *_ctx, void *buf, size_t nbytes)
{
    lmtp2nntp_t *ctx = (lmtp2nntp_t *)_ctx;
    ssize_t rc;
    size_t n;
    sa_rc_t rv;

    if (ctx->saIO != NULL) {
        if ((rv = sa_read(ctx->saIO, buf, nbytes, &n)) != SA_OK) {
            if (rv == SA_ERR_SYS)
                logbook(ctx->l2, L2_LEVEL_DEBUG, "hook_lmtp_read() sa_read failed with \"%s\" (%d) %s", sa_error(rv), errno, strerror(errno));
            else
                logbook(ctx->l2, L2_LEVEL_DEBUG, "hook_lmtp_read() sa_read failed with \"%s\"", sa_error(rv));
            if (rv == SA_ERR_EOF)
                rc = 0;
            else
                rc = -1;
            sa2errno(rv);
        }
        else
            rc = (ssize_t)n;
    }
    else {
        rc = read(ctx->fdIOi, buf, nbytes);
        if (rc == -1)
            logbook(ctx->l2, L2_LEVEL_DEBUG, "hook_lmtp_read() read failed with (%d) %s", errno, strerror(errno));
    }
    if (rc == -1)
        logbook(ctx->l2, L2_LEVEL_TRACE, "LMTP read error: %m");
    else
        logbook(ctx->l2, L2_LEVEL_TRACE, "LMTP %5d << \"%{text}D\"", rc, buf, rc);
    logbook(ctx->l2, L2_LEVEL_DEBUG, "hook_lmtp_read() return, rc=%d", rc);
    return rc;
}

static ssize_t hook_lmtp_write(void *_ctx, const void *buf, size_t nbytes)
{
    lmtp2nntp_t *ctx = (lmtp2nntp_t *)_ctx;
    ssize_t rc;
    size_t n;
    sa_rc_t rv;

    logbook(ctx->l2, L2_LEVEL_TRACE, "LMTP %5d >> \"%{text}D\"", nbytes, buf, nbytes);
    if (ctx->saIO != NULL) {
        if ((rv = sa_write(ctx->saIO, buf, nbytes, &n)) != SA_OK) {
            if (rv == SA_ERR_SYS)
                logbook(ctx->l2, L2_LEVEL_DEBUG, "hook_lmtp_write() sa_write failed with \"%s\" (%d) %s", sa_error(rv), errno, strerror(errno));
            else
                logbook(ctx->l2, L2_LEVEL_DEBUG, "hook_lmtp_write() sa_write failed with \"%s\"", sa_error(rv));
            rc = -1;
            sa2errno(rv);
        }
        else
            rc = (ssize_t)n;
    }
    else {
        rc = write(ctx->fdIOo, buf, nbytes);
        if (rc == -1)
            logbook(ctx->l2, L2_LEVEL_DEBUG, "hook_lmtp_write() write failed with (%d) %s", errno, strerror(errno));
    }
    if (rc == -1)
        logbook(ctx->l2, L2_LEVEL_TRACE, "LMTP write error");
    return rc;
}

static ssize_t hook_nntp_read(void *_ctx, void *buf, size_t nbytes)
{
    struct ns *ctx = (struct ns *)_ctx;
    ssize_t rc;
    size_t n;
    sa_rc_t rv;

    if ((rv = sa_read(ctx->sa, buf, nbytes, &n)) != SA_OK) {
        if (rv == SA_ERR_SYS)
            logbook(ctx->l2, L2_LEVEL_DEBUG, "hook_lmtp_read() sa_read failed with \"%s\" (%d) %s", sa_error(rv), errno, strerror(errno));
        else
            logbook(ctx->l2, L2_LEVEL_DEBUG, "hook_lmtp_read() sa_read failed with \"%s\"", sa_error(rv));
        if (rv == SA_ERR_EOF)
            rc = 0;
        else
            rc = -1;
        sa2errno(rv);
    }
    else
        rc = (ssize_t)n;
    if (rc == -1)
        logbook(ctx->l2, L2_LEVEL_TRACE, "NNTP read error: %m");
    else
        logbook(ctx->l2, L2_LEVEL_TRACE, "NNTP %5d << \"%{text}D\"", rc, buf, rc);
    return rc;
}

static ssize_t hook_nntp_write(void *_ctx, const void *buf, size_t nbytes)
{
    struct ns *ctx = (struct ns *)_ctx;
    ssize_t rc;
    size_t n;
    sa_rc_t rv;

    logbook(ctx->l2, L2_LEVEL_TRACE, "NNTP %5d >> \"%{text}D\"", nbytes, buf, nbytes);
    if ((rv = sa_write(ctx->sa, buf, nbytes, &n)) != SA_OK) {
        if (rv == SA_ERR_SYS)
            logbook(ctx->l2, L2_LEVEL_DEBUG, "hook_nntp_write() sa_write failed with \"%s\" (%d) %s", sa_error(rv), errno, strerror(errno));
        else
            logbook(ctx->l2, L2_LEVEL_DEBUG, "hook_nntp_write() sa_write failed with \"%s\"", sa_error(rv));
        rc = -1;
        sa2errno(rv);
    }
    else
        rc = (ssize_t)n;
    if (rc == -1)
        logbook(ctx->l2, L2_LEVEL_TRACE, "NNTP write error");
    return rc;
}

static void catchsignal(int sig, ...)
{
    va_list ap;
    static lmtp2nntp_t *ctx = NULL;
    pid_t pid;

    if(sig == 0) {
        va_start(ap, sig);
        if ((ctx = va_arg(ap, lmtp2nntp_t *)) == NULL)
            exit(ERR_EXECUTION);
        logbook(ctx->l2, L2_LEVEL_TRACE, "catching and logging signals now");
        va_end(ap);
        return;
    }
    if (ctx != NULL) {
        switch (sig) {
            case SIGCHLD:
                logbook(ctx->l2, L2_LEVEL_NOTICE, "caught signal %d - wait for child", sig);
                pid = wait(NULL);
                ctx->active_childs--;
                logbook(ctx->l2, L2_LEVEL_NOTICE, "caught signal %d - child [%ld] terminated", sig, (long)pid);
                signal(sig, (void(*)())catchsignal);
                return;
            case SIGUSR1:
                logbook(ctx->l2, L2_LEVEL_NOTICE, "caught signal %d - flush logging stream", sig);
                l2_channel_flush(ctx->l2);
                signal(sig, (void(*)())catchsignal);
                return;
            case SIGHUP:
            case SIGINT:
            case SIGQUIT:
                logbook(ctx->l2, L2_LEVEL_NOTICE, "caught signal %d - exit - no more logging", sig);
                break;
            default:
                logbook(ctx->l2, L2_LEVEL_PANIC, "CAUGHT SIGNAL %d - EXIT - NO MORE LOGGING", sig);
        }
        l2_channel_destroy(ctx->l2);
        l2_env_destroy(ctx->l2_env);
    }
    exit(ERR_EXECUTION);
}

int main(int argc, char **argv)
{
    int           rc;
    lmtp_t       *lmtp = NULL;
    lmtp_io_t     lmtp_io;
    lmtp2nntp_t  *ctx = NULL;
    int           bOk;
    int           i;             /* general purpose scratch int, index ... */
    pid_t         pid;
    FILE         *fd;
    lmtp2nntp_option_t *o;

    /* drop effective uid/gid privileges */
    seteuid(getuid());
    setegid(getgid());

    /* use unbuffered stdio */
    setvbuf(stdin,  NULL, _IONBF, 0);
    setvbuf(stdout, NULL, _IONBF, 0);
    setvbuf(stderr, NULL, _IONBF, 0);

    /* library version check (run-time) */
    if (l2_version.v_hex < L2_VERSION_HEX_REQ) {
        fprintf(stderr, "require OSSP L2 >= %s, found %s\n", L2_VERSION_STR_REQ, L2_VERSION_STR);
        CU(ERR_EXECUTION);
    }
    if (str_version.v_hex < STR_VERSION_HEX_REQ) {
        fprintf(stderr, "require OSSP Str >= %s, found %s\n", STR_VERSION_STR_REQ, STR_VERSION_STR);
        CU(ERR_EXECUTION);
    }

    /* create application context. fields are initialized to values that allow
     * detection of dynamic allocated resources which must be freed up for
     * graceful cleanup. These values are not necessarily useful application
     * defaults. Those defaults must be configured in lmtp2nntp_option.c
     * through option_register() calls */
    if ((ctx = (lmtp2nntp_t *)malloc(sizeof(lmtp2nntp_t))) == NULL)
        CU(ERR_EXECUTION);
    ctx->ctx.vp = ctx;
    ctx->prival = NULL;
    ctx->val = NULL;
    ctx->progname = NULL;
    ctx->option_groupmode = GROUPMODE_UNDEF;
    ctx->option_operationmode = OPERATIONMODE_UNDEF;
    ctx->option_operationmodefakestatus = NULL;
    ctx->option_operationmodefakedsn    = NULL; /* is joined to fakestatus in a single malloc(3) */
    ctx->option_maxmessagesize = 0;
    ctx->option_firstheaderrule = NULL;
    ctx->option_timeout_lmtp_accept  = 0;
    ctx->option_timeout_lmtp_read    = 0;
    ctx->option_timeout_lmtp_write   = 0;
    ctx->option_timeout_nntp_connect = 0;
    ctx->option_timeout_nntp_read    = 0;
    ctx->option_timeout_nntp_write   = 0;
    ctx->option_nodename = NULL;
    ctx->option_mailfrom = NULL;
    ctx->option_restrictheader = NULL;
    ctx->option_pidfile = NULL;
    ctx->option_killflag = FALSE;
    ctx->option_uid = getuid();
    ctx->option_daemon = FALSE;
    ctx->nacl = 0;
    ctx->pacl = NULL;
    ctx->option_childsmax = 0;
    ctx->active_childs = 0;
    ctx->l2_env = NULL;
    ctx->l2 = NULL;
    ctx->saaServerbind = NULL;
    ctx->saServerbind = NULL;
    ctx->saaClientbind = NULL;
    ctx->saClientbind = NULL;
    ctx->saaIO = NULL;
    ctx->saIO = NULL;
    ctx->fdIOi = -1;
    ctx->fdIOo = -1;
    ctx->nns = 0;
    ctx->pns = NULL;
    ctx->azGroupargs = NULL;
    ctx->asGroupargs = 0;
    initsession(&ctx->session);
    ctx->msg = NULL;
    ctx->config_varregex = NULL;
    ctx->config_varctx = NULL;
    ctx->msgcount = 0;

    /* private application context */
    if (val_create(&ctx->prival) != VAL_OK)
        CU(ERR_EXECUTION);

    /* create printable variables context and mount it into the private application context */
    if (val_create(&ctx->val) != VAL_OK)
        CU(ERR_EXECUTION);
    if (val_reg(ctx->prival, "printable", VAL_TYPE_VAL, "printable variables", NULL) != VAL_OK)
        CU(ERR_EXECUTION);
    if (val_set(ctx->prival, "printable", ctx->val) != VAL_OK)
        CU(ERR_EXECUTION);

    /* feed lib_val */
    if (val_reg(ctx->prival, "msgcount", VAL_TYPE_INT, "number of messages processed so far", (void *)&ctx->msgcount) != VAL_OK)
        CU(ERR_EXECUTION);
    if (val_reg(ctx->prival, "nodename", VAL_TYPE_PTR, "nodename configured or uname(3)", (void *)&ctx->option_nodename) != VAL_OK)
        CU(ERR_EXECUTION);

    /* set progname */
    ctx->progname = strdup(argv[0]);

    /* establish variable expansion context */
    {
        char *cp;

        if ((rc = var_create(&ctx->config_varctx)) != VAR_OK) {
            fprintf(stderr, "%s:Error: create varctx context failed with %s (%d)", ctx->progname, var_strerror(ctx->config_varctx, rc, &cp) == VAR_OK ? cp : "Unknown Error", rc);
            CU(ERR_EXECUTION);
        }
        if ((rc = var_config(ctx->config_varctx, VAR_CONFIG_SYNTAX, &syntax_ctx)) != VAR_OK) {
            fprintf(stderr, "%s:Error: config varctx context failed with %s (%d)", ctx->progname, var_strerror(ctx->config_varctx, rc, &cp) == VAR_OK ? cp : "Unknown Error", rc);
            CU(ERR_EXECUTION);
        }
        if ((rc = var_config(ctx->config_varctx, VAR_CONFIG_CB_VALUE, ctx_lookup, ctx)) != VAR_OK) {
            fprintf(stderr, "%s:Error: config varctx callback failed with %s (%d)", ctx->progname, var_strerror(ctx->config_varctx, rc, &cp) == VAR_OK ? cp : "Unknown Error", rc);
            CU(ERR_EXECUTION);
        }
    }


    /* read in the arguments */
    {
        lmtp2nntp_option_rc_t rvo;
        lmtp2nntp_config_rc_t rvc;
        ex_t ex;

        if (option_create(&o, ctx->val) != OPTION_OK)
            CU(ERR_EXECUTION);
        rvo = option_parse(o, argc, argv);
        rvc = CONFIG_OK;
        try {
            rvc = config_context(ctx);
        }
        catch(ex) {
            rvc = CONFIG_ERR_TRY;
        }
        if (rvc == CONFIG_OK_DRY)
            CU(0);
        if (rvo != OPTION_OK || rvc != CONFIG_OK)
            CU(ERR_EXECUTION);
    }

    if (getuid() != ctx->option_uid) {
        if (setuid(ctx->option_uid) == -1) {
            fprintf(stderr, "%s:Error: Setting UID to %d failed: %s\n",
                    ctx->progname, (int)ctx->option_uid, strerror(errno));
            CU(ERR_EXECUTION);
        }
    }

    if ((ctx->option_pidfile != NULL) && ctx->option_killflag) {
        if ((fd = fopen(ctx->option_pidfile, "r")) == NULL)
            logbook(ctx->l2, L2_LEVEL_ERROR, "cannot open pidfile \"%s\" for reading %m", ctx->option_pidfile);
        else {
            if (fscanf(fd, "%d\n", (int *)&pid) != 1) {
                fclose(fd);
                logbook(ctx->l2, L2_LEVEL_ERROR, "cannot extract pid from pidfile \"%s\"", ctx->option_pidfile);
            }
            else {
                fclose(fd);
                logbook(ctx->l2, L2_LEVEL_TRACE, "going to kill pid[%d]", pid);
                if (kill(pid, SIGHUP) == -1)
                    logbook(ctx->l2, L2_LEVEL_ERROR, "killing pid[%d] failed %m", pid);
                if (unlink(ctx->option_pidfile) == -1)
                    logbook(ctx->l2, L2_LEVEL_ERROR, "unlinking pidfile \"%s\" failed %m", ctx->option_pidfile);
            }
        }
        CU(0);
    }

    catchsignal(0, ctx);
    signal(SIGCHLD, (void(*)())catchsignal);
    signal(SIGHUP,  (void(*)())catchsignal);
    signal(SIGINT,  (void(*)())catchsignal);
    signal(SIGQUIT, (void(*)())catchsignal);
    signal(SIGILL,  (void(*)())catchsignal);
    signal(SIGBUS,  (void(*)())catchsignal);
    signal(SIGSEGV, (void(*)())catchsignal);
    signal(SIGSYS,  (void(*)())catchsignal);
    signal(SIGTERM, (void(*)())catchsignal);
    signal(SIGUSR1, (void(*)())catchsignal);
    signal(SIGUSR2,            SIG_IGN    );

    /* loop for LMTP protocol with support for alternate io through daemon */
    if (ctx->saServerbind == NULL) {
        /* initialize LMTP context */
        ctx->fdIOi = STDIN_FILENO;
        ctx->fdIOo = STDOUT_FILENO;
        lmtp_io.ctx    = ctx;
        lmtp_io.read   = hook_lmtp_read;
        lmtp_io.write  = hook_lmtp_write;
        if ((lmtp = lmtp_create(&lmtp_io)) == NULL) {
            logbook(ctx->l2, L2_LEVEL_ERROR, "Unable to initialize LMTP library\n");
            CU(ERR_EXECUTION);
        }
        /*  RFC0821, 4.5.1. MINIMUM IMPLEMENTATION
         *  In order to make SMTP workable, the following minimum implementation
         *  is required for all receivers: [...]
         *  RFC0821, 4.1.2. COMMAND SYNTAX
         *
         *  Verb Parameter
         *  ----+-------------------------------
         *  HELO <SP> <domain> <CRLF>
         *  MAIL <SP> FROM:<reverse-path> <CRLF>
         *  RCPT <SP> TO:<forward-path> <CRLF>
         *  DATA <CRLF>
         *  RSET <CRLF>
         *  NOOP <CRLF>
         *  QUIT <CRLF>
         */
        lmtp_register(lmtp, "LHLO", lmtp_cb_lhlo, ctx, NULL, NULL);
        lmtp_register(lmtp, "MAIL", lmtp_cb_mail, ctx, NULL, NULL);
        lmtp_register(lmtp, "RCPT", lmtp_cb_rcpt, ctx, NULL, NULL);
        lmtp_register(lmtp, "DATA", lmtp_cb_data, ctx, NULL, NULL);
        lmtp_register(lmtp, "RSET", lmtp_cb_rset, ctx, NULL, NULL);
        lmtp_register(lmtp, "NOOP", lmtp_cb_noop, ctx, NULL, NULL);
        lmtp_register(lmtp, "QUIT", lmtp_cb_quit, ctx, NULL, NULL);
        lmtp_loop(lmtp);
        lmtp_gfs_quit(ctx);
        lmtp_gfs_lhlo(ctx);
        lmtp_destroy(lmtp);
    } else {
        pid = getpid();
        if (ctx->option_daemon) {
            daemonize();
            logbook(ctx->l2, L2_LEVEL_NOTICE, "daemonized, previous pid[%d]", pid);
        }
        if (ctx->option_pidfile != NULL) {
            if ((fd = fopen(ctx->option_pidfile, "w+")) == NULL)
                logbook(ctx->l2, L2_LEVEL_ERROR, "cannot open pidfile \"%s\" for writing %m", ctx->option_pidfile);
            else {
                fprintf(fd, "%d\n", (int)getpid());
                fclose(fd);
            }
        }

        sa_timeout(ctx->saServerbind, SA_TIMEOUT_ALL,    0, 0);
        sa_timeout(ctx->saServerbind, SA_TIMEOUT_ACCEPT, ctx->option_timeout_lmtp_accept, 0);
        sa_timeout(ctx->saServerbind, SA_TIMEOUT_READ,   ctx->option_timeout_lmtp_read,   0);
        sa_timeout(ctx->saServerbind, SA_TIMEOUT_WRITE,  ctx->option_timeout_lmtp_write,  0);
        while (1) {
            while (ctx->active_childs >= ctx->option_childsmax) {
                logbook(ctx->l2, L2_LEVEL_ERROR, "maximum number of childs (%d) reached - waiting (1s)", ctx->option_childsmax);
                sleep(1);
            }

            if ((rc = sa_accept(ctx->saServerbind, &ctx->saaIO, &ctx->saIO)) != SA_OK) {
                if (rc == SA_ERR_SYS)
                    logbook(ctx->l2, L2_LEVEL_ERROR, "accept failed: %s: (%d) %s", sa_error(rc), errno, strerror(errno));
                else
                    logbook(ctx->l2, L2_LEVEL_ERROR, "accept failed: %s", sa_error(rc));
                sleep(10);
                continue;
            }

            /* Access Control List */
            bOk = FALSE;
            /* check positive matches */
            for (i = 0; i < ctx->nacl; i++) {
                char *cpA1;
                char *cpA2;
                if (ctx->pacl[i].not)
                    continue;
                sa_addr_a2u(ctx->pacl[i].saa, &cpA1);
                sa_addr_a2u(ctx->saaIO, &cpA2);
                if (sa_addr_match(ctx->saaIO, ctx->pacl[i].saa, ctx->pacl[i].prefixlen) == SA_OK) {
                    logbook(ctx->l2, L2_LEVEL_TRACE, "positive/inclusive ACL \"%s\" (%s/%d) matches %s: YES (stop comparison)", ctx->pacl[i].acl, cpA1, ctx->pacl[i].prefixlen, cpA2);
                    bOk = TRUE;
                    break;
                }
                else
                    logbook(ctx->l2, L2_LEVEL_TRACE, "positive/inclusive ACL \"%s\" (%s/%d) matches %s: NO", ctx->pacl[i].acl, cpA1, ctx->pacl[i].prefixlen, cpA2);
                free(cpA1);
                free(cpA2);
            }
            /* check negative matches */
            for (i = 0; i < ctx->nacl; i++) {
                char *cpA1;
                char *cpA2;
                if (!ctx->pacl[i].not)
                    continue;
                sa_addr_a2u(ctx->pacl[i].saa, &cpA1);
                sa_addr_a2u(ctx->saaIO, &cpA2);
                if (sa_addr_match(ctx->saaIO, ctx->pacl[i].saa, ctx->pacl[i].prefixlen) == SA_OK) {
                    logbook(ctx->l2, L2_LEVEL_TRACE, "negative/exclusive ACL \"%s\" (not %s/%d) matches %s: YES (stop comparison)", ctx->pacl[i].acl, cpA1, ctx->pacl[i].prefixlen, cpA2);
                    bOk = FALSE;
                    break;
                }
                else {
                    logbook(ctx->l2, L2_LEVEL_TRACE, "negative/exclusive ACL \"%s\" (not %s/%d) matches %s: NO", ctx->pacl[i].acl, cpA1, ctx->pacl[i].prefixlen, cpA2);
                }
            }
            if (bOk) {
                char *cpA;
                sa_addr_a2u(ctx->saaIO, &cpA);
                logbook(ctx->l2, L2_LEVEL_TRACE, "connection from %s accepted due to ACL", cpA);
                free(cpA);
            }
            else {
                char *cpA;
                sa_addr_a2u(ctx->saaIO, &cpA);
                logbook(ctx->l2, L2_LEVEL_ERROR, "connection from %s refused due to ACL", cpA);
                free(cpA);
                sa_destroy(ctx->saIO);
                sa_addr_destroy(ctx->saaIO);
                continue;
            }

            /* logging buffer must be empty before fork otherwise content is
             * duplicated and written twice on next flush */
            l2_channel_flush(ctx->l2);
            pid = fork();
            if (pid == -1) {
                logbook(ctx->l2, L2_LEVEL_ERROR, "daemon cannot spawn child %m");
                continue;
            }
            if (pid != 0) {
                logbook(ctx->l2, L2_LEVEL_INFO, "daemon forked process, new child pid[%d]", pid);
                ctx->active_childs++;
                sa_destroy(ctx->saIO);
                sa_addr_destroy(ctx->saaIO);
                continue;
            }
            logbook(ctx->l2, L2_LEVEL_NOTICE, "startup new child process, parent pid[%d]", getppid());

            /* child must close listening socket */
            sa_destroy(ctx->saServerbind);
            ctx->saServerbind = NULL; /* prevent cleanup from free'ing this again */

            /* initialize LMTP context */
            lmtp_io.ctx    = ctx;
            lmtp_io.read   = hook_lmtp_read;
            lmtp_io.write  = hook_lmtp_write;
            if ((lmtp = lmtp_create(&lmtp_io)) == NULL) {
                logbook(ctx->l2, L2_LEVEL_ERROR, "Unable to initialize LMTP library\n");
                CU(ERR_EXECUTION);
            }
            /*  RFC0821, 4.5.1. MINIMUM IMPLEMENTATION
             *  In order to make SMTP workable, the following minimum implementation
             *  is required for all receivers: [...]
             *  RFC0821, 4.1.2. COMMAND SYNTAX
             *
             *  Verb Parameter
             *  ----+-------------------------------
             *  HELO <SP> <domain> <CRLF>
             *  MAIL <SP> FROM:<reverse-path> <CRLF>
             *  RCPT <SP> TO:<forward-path> <CRLF>
             *  DATA <CRLF>
             *  RSET <CRLF>
             *  NOOP <CRLF>
             *  QUIT <CRLF>
             */
            lmtp_register(lmtp, "LHLO", lmtp_cb_lhlo, ctx, NULL, NULL);
            lmtp_register(lmtp, "MAIL", lmtp_cb_mail, ctx, NULL, NULL);
            lmtp_register(lmtp, "RCPT", lmtp_cb_rcpt, ctx, NULL, NULL);
            lmtp_register(lmtp, "DATA", lmtp_cb_data, ctx, NULL, NULL);
            lmtp_register(lmtp, "RSET", lmtp_cb_rset, ctx, NULL, NULL);
            lmtp_register(lmtp, "NOOP", lmtp_cb_noop, ctx, NULL, NULL);
            lmtp_register(lmtp, "QUIT", lmtp_cb_quit, ctx, NULL, NULL);
            lmtp_loop(lmtp);
            lmtp_gfs_quit(ctx);
            lmtp_gfs_lhlo(ctx);
            lmtp_destroy(lmtp);
            CU(0);
        }
    }
    CU(0);

    /* graceful shutdown */
    CUS:
    signal(SIGCHLD, SIG_DFL);
    signal(SIGHUP,  SIG_DFL);
    signal(SIGINT,  SIG_DFL);
    signal(SIGQUIT, SIG_DFL);
    signal(SIGILL,  SIG_DFL);
    signal(SIGBUS,  SIG_DFL);
    signal(SIGSEGV, SIG_DFL);
    signal(SIGSYS,  SIG_DFL);
    signal(SIGTERM, SIG_DFL);
    signal(SIGUSR1, SIG_DFL);
    signal(SIGUSR2, SIG_DFL);
    logbook(ctx->l2, L2_LEVEL_NOTICE, "graceful shutdown shortly before exit - no more logging");
    if (ctx->l2 != NULL)
        l2_channel_destroy(ctx->l2);
    if (ctx->l2_env != NULL)
        l2_env_destroy(ctx->l2_env);
    if (ctx->saServerbind)
        sa_destroy(ctx->saServerbind);
    if (ctx->saaServerbind)
        sa_addr_destroy(ctx->saaServerbind);
    if (ctx->option_restrictheader != NULL)
        free(ctx->option_restrictheader);
    if (ctx->option_pidfile != NULL)
        free(ctx->option_pidfile);
    if (ctx->pns != NULL)
        free(ctx->pns);
    if (ctx->pacl != NULL) {
        for (i = 0; i < ctx->nacl; i++)
            if (ctx->pacl[i].saa != NULL)
                sa_addr_destroy(ctx->pacl[i].saa);
        free(ctx->pacl);
    }
    if (ctx->option_nodename != NULL)
        free(ctx->option_nodename);
    if (ctx->prival != NULL)
        val_destroy(ctx->prival);
    if (ctx->val != NULL)
        val_destroy(ctx->val);
    if (ctx->progname != NULL)
        free(ctx->progname);
    if (ctx->azGroupargs != NULL)
        free(ctx->azGroupargs);
    if (ctx->config_varregex != NULL)
        var_destroy(ctx->config_varregex);
    if (ctx->config_varctx != NULL)
        var_destroy(ctx->config_varctx);
    if (ctx->option_operationmodefakestatus != NULL)
        free(ctx->option_operationmodefakestatus); /* includes dsn */
    if (ctx != NULL)
        free(ctx);
    str_parse(NULL, NULL);
    if (o != NULL)
        (void)option_destroy(o);
    return rc;
}

static void resetsession(struct session *session)
{
    if (session->lhlo_domain != NULL)
        free(session->lhlo_domain);
    initsession(session);
    return;
}

static void initsession(struct session *session)
{
    session->lhlo_seen = FALSE;
    session->lhlo_domain = NULL;
    return;
}

static lmtp_rc_t lmtp_cb_lhlo(lmtp_t *lmtp, lmtp_io_t *io, lmtp_req_t *req, void *_ctx)
{
    /*
     *  RFC0821 [excerpt] 4.1. SMTP COMMANDS
     *  4.1.1.  COMMAND SEMANTICS, HELO
     *  This command and an OK reply to it confirm that both the sender-SMTP
     *  and the receiver-SMTP are in the initial state, that is, there is no
     *  transaction in progress and all state tables and buffers are cleared.
     *
     *  The first command in a session must be the HELO command.  The HELO
     *  command may be used later in a session as well.  If the HELO command
     *  argument is not acceptable a 501 failure reply must be returned and
     *  the receiver-SMTP must stay in the same state.
     *
     *  If the transaction beginning command argument is not acceptable a 501
     *  failure reply must be returned and the receiver-SMTP must stay in the
     *  same state.  If the commands in a transaction are out of order a 503
     *  failure reply must be returned and the receiver-SMTP must stay in the
     *  same state.
     *
     *  HELO <SP> <domain> <CRLF>
     */
    lmtp2nntp_t *ctx = (lmtp2nntp_t *)_ctx;
    nntp_rc_t    rc;
    lmtp_res_t   res;
    char         str[STDSTRLEN];
    int          bOk;
    int          i;
    int          is;
    nntp_io_t    nntp_io;

    logbook(ctx->l2, L2_LEVEL_INFO, "LMTP service executing LHLO command < %s", req->msg);

    /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   503 Bad sequence of commands
     *  RFC1893 2. Status Codes                         5.X.X   Permanent Failure
     *  RFC1893 3.5 Network and Routing Status          X.0.0   Other undefined Status
     */
    logbook(ctx->l2, L2_LEVEL_TRACE, "checking for duplicate LHLO");
    if (ctx->session.lhlo_seen) {
        res.statuscode = "503";
        res.dsncode    = "5.0.0";
        res.statusmsg  = "Duplicate LHLO.";
        CU(LMTP_OK);
    }

    /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   501 Syntax error in parameters or arguments
     *  RFC1893 2. Status Codes                         5.X.X   Permanent Failure
     *  RFC1893 3.5 Network and Routing Status          X.0.0   Other undefined Status
     */
    logbook(ctx->l2, L2_LEVEL_TRACE, "checking domain to match either RFC0821 or RFC1035 syntax");
    if (! (   helo_rfc0821domain(req->msg, &ctx->session.lhlo_domain) > 0
           || helo_rfc1035domain(req->msg, &ctx->session.lhlo_domain) > 0)) {
        res.statuscode = "501";
        res.dsncode    = "5.0.0";
        res.statusmsg  = "Please identify yourself. Domain must match RFC0821/RFC1035.";
        CU(LMTP_OK);
    }

    /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   451 Requested action aborted: local error in processing
     *  RFC1893 2. Status Codes                         4.X.X   Persistent Transient Failure
     *  RFC1893 3.5 Network and Routing Status          X.3.5   System incorrectly configured
     */
    if (ctx->option_operationmode != OPERATIONMODE_FAKE) {
        logbook(ctx->l2, L2_LEVEL_TRACE, "check if at least one NNTP service was successfully configured");
        if (ctx->nns == 0) {
            res.statuscode = "451";
            res.dsncode    = "4.3.5";
            res.statusmsg  = "No valid NNTP services configured.";
            CU(LMTP_OK);
        }
    }

    logbook(ctx->l2, L2_LEVEL_TRACE, "try to establish a session to any configured NNTP services");
    if (ctx->option_operationmode == OPERATIONMODE_FAKE)
        logbook(ctx->l2, L2_LEVEL_NOTICE, "NNTP running in fake mode, network connections will be executed but result is ignored");
    i = 0;
    is = 0;
    while (i < ctx->nns) {
        logbook(ctx->l2, L2_LEVEL_DEBUG, "trying ns[%d]", i);
        bOk = TRUE;
        logbook(ctx->l2, L2_LEVEL_TRACE, "try destination#%d ${option.destination[%d]}", i, i);

        ctx->pns[i].l2 = ctx->l2;

        if (bOk && (ctx->saaClientbind != NULL)) {
            logbook(ctx->l2, L2_LEVEL_DEBUG, "bind local socket to ${option.client}");
            if (sa_bind(ctx->pns[i].sa, ctx->saaClientbind) != SA_OK) {
                bOk = FALSE;
                logbook(ctx->l2, L2_LEVEL_ERROR, "binding NNTP client to local address ${option.client} failed, %m");
            }
        }

        sa_timeout(ctx->pns[i].sa, SA_TIMEOUT_ALL, 0, 0);
        sa_timeout(ctx->pns[i].sa, SA_TIMEOUT_CONNECT, ctx->option_timeout_nntp_connect, 0);
        sa_timeout(ctx->pns[i].sa, SA_TIMEOUT_READ,    ctx->option_timeout_nntp_read,    0);
        sa_timeout(ctx->pns[i].sa, SA_TIMEOUT_WRITE,   ctx->option_timeout_nntp_read,    0);

        if (bOk) {
            logbook(ctx->l2, L2_LEVEL_DEBUG, "connect");
            if (sa_connect(ctx->pns[i].sa, ctx->pns[i].saa) != SA_OK) {
                bOk = FALSE;
                logbook(ctx->l2, L2_LEVEL_WARNING, "connect to destination#%d ${option.destination[%d]} failed, %m", i, i);
            }
        }

        if (bOk) {
            logbook(ctx->l2, L2_LEVEL_DEBUG, "nntp_create");
            nntp_io.ctx    = &ctx->pns[i];
            nntp_io.read   = hook_nntp_read;
            nntp_io.write  = hook_nntp_write;
            if ((ctx->pns[i].nntp = nntp_create(&nntp_io)) == NULL) {
                bOk = FALSE;
                logbook(ctx->l2, L2_LEVEL_ERROR, "creation of NNTP context failed");
            }
        }

        if (bOk) {
            logbook(ctx->l2, L2_LEVEL_DEBUG, "nntp_init");
            if ((rc = nntp_init(ctx->pns[i].nntp)) != NNTP_OK) {
                bOk = FALSE;
                logbook(ctx->l2, L2_LEVEL_ERROR, "initialization of NNTP context failed, (%d) %s", rc, nntp_error(rc));
            }
        }

        if (bOk) {
            logbook(ctx->l2, L2_LEVEL_INFO, "NNTP session to destination#%d ${option.destination[%d]} successfully established", i, i);
            is++;
        }
        else {
            logbook(ctx->l2, L2_LEVEL_WARNING, "NNTP session establishment to destination#%d ${option.destination[%d]} failed", i, i);
            lmtp_gfs_ns(&ctx->pns[i]);
        }
        i++;
    }
    logbook(ctx->l2, L2_LEVEL_INFO, "NNTP network connections tried %d, successful %d", i, is);

    if (ctx->option_operationmode == OPERATIONMODE_FAKE)
        logbook(ctx->l2, L2_LEVEL_NOTICE, "NNTP running in fake mode, ignoring status of real network connections");
    else
    {
        /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   421 <domain> Service not available
         *  RFC1893 2. Status Codes                         4.X.X   Persistent Transient Failure
         *  RFC1893 3.5 Network and Routing Status          X.4.1   No answer from host
         */
        logbook(ctx->l2, L2_LEVEL_DEBUG, "check if at least one NNTP session successfully established");
        if (is == 0) {
            logbook(ctx->l2, L2_LEVEL_ERROR, "no NNTP session established");
            res.statuscode = "421";
            res.dsncode    = "4.4.1";
            res.statusmsg  = "No NNTP session established.";
            CU(LMTP_OK);
        }
    }

    ctx->session.lhlo_seen = TRUE;

    /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   250 Requested mail action okay, completed
     */
    str_format(str, sizeof(str),
               "%s Hello %s, pleased to meet you.\n" /* RFC2821 4.1.1.1 */
               "ENHANCEDSTATUSCODES\n"               /* RFC2034 */
               "DSN\n"                               /* RFC1894 */
               "PIPELINING\n"                        /* RFC1854 */
               "8BITMIME",                           /* RFC1652 */
               ctx->option_nodename,
               ctx->session.lhlo_domain);
    res.statuscode = "250";
    res.dsncode    = NULL; /* DSN not used for greeting */
    res.statusmsg  = str;
    CU(LMTP_OK);

    CUS:
    lmtp_response(lmtp, &res);
    return rc;
}

static void lmtp_gfs_ns(struct ns *ns)
{
    if (ns->nntp != NULL) {
        nntp_destroy(ns->nntp);
        ns->nntp = NULL;
    }
    if (ns->sa != NULL) {
        sa_destroy(ns->sa);
        ns->sa = NULL;
    }
    if (ns->saa != NULL) {
        sa_addr_destroy(ns->saa);
        ns->saa = NULL;
    }
}

static void lmtp_gfs_lhlo(lmtp2nntp_t *ctx)
{
    int i;

    logbook(ctx->l2, L2_LEVEL_TRACE, "LMTP service LHLO command - graceful shutdown");

    for (i = 0; i < ctx->nns; i++)
            lmtp_gfs_ns(&ctx->pns[i]);

    if (ctx->option_mailfrom != NULL)
        free(ctx->option_mailfrom);
    if (ctx->saClientbind != NULL)
        sa_destroy(ctx->saClientbind);
    if (ctx->saaClientbind != NULL)
        sa_addr_destroy(ctx->saaClientbind);
}

static int helo_rfc0821domain(char *msg, char **domain)
{
    int rc;

    rc = str_parse(msg,
            "^.+ ("
    /*
     ##
     ##  The mega Perl regular expression below is generated
     ##  with the following Perl program. This is only possible
     ##  because the given grammar is Chomsky-3 (right or left
     ##  linear grammar, but noth both).
     ##

     # BNF grammar for <domain> according to RFC0821:
     # <snum>        ::= one, two, or three digits representing a decimal integer value in the range 0 through 255
     # <a>           ::= any one of the 52 alphabetic characters A through Z in upper case and a through z in lower case
     # <d>           ::= any one of the ten digits 0 through 9
     # <let-dig-hyp> ::= <a> | <d> | "-"
     # <let-dig>     ::= <a> | <d>
     # <ldh-str>     ::= <let-dig-hyp> | <let-dig-hyp> <ldh-str>
     # <dotnum>      ::= <snum> "." <snum> "." <snum> "." <snum>
     # <number>      ::= <d> | <d> <number>
     # <name>        ::= <a> <ldh-str> <let-dig>
     # <element>     ::= <name> | "#" <number> | "[" <dotnum> "]"
     # <domain>      ::= <element> | <element> "." <domain>
     #
     # corresponding Perl regular expression ($domain)
     $snum        = "(?:[0-9]|[0-9]{2}|[0-1][0-9]{2}|2[0-4][0-9]|25[0-5])";
     $d           = "[0-9]";
     $a           = "[A-Za-z]";
     $let_dig_hyp = "(?:$a|$d|-)";
     $let_dig     = "(?:$a|$d)";
     $ldh_str     = "${let_dig_hyp}+";
     $dotnum      = "$snum\\.$snum\\.$snum\\.$snum";
     $number      = "$d+";
     $name        = "$a$ldh_str$let_dig";
     $element     = "(?:$name|#$number|\\[$dotnum\\])";
     $domain      = "(?:$element\.)*$element";
     #
     # translate into C string block suitable for passing to the Perl
     # Compatible Regular Expressions (PCRE) based string library Str.
     my $cregex = $domain;
     $cregex .= "\n";
     $cregex =~ s|\\|\\\\|sg;
     $cregex =~ s|(.{17})|$1\n|sg;
     $cregex =~ s|([^\n]+)\n|"$1"\n|sg;
     $cregex =~ s|\n\n|\n|sg;
     print "$cregex";
     */

    "(?:(?:[A-Za-z](?:[A-Za-z]|[0-9]|-)+(?:[A-Za-z]|[0-9])|#[0-9]+|\\[(?:[0"
    "-9]|[0-9]{2}|[0-1][0-9]{2}|2[0-4][0-9]|25[0-5])\\.(?:[0-9]|[0-9]{2}|[0"
    "-1][0-9]{2}|2[0-4][0-9]|25[0-5])\\.(?:[0-9]|[0-9]{2}|[0-1][0-9]{2}|2[0"
    "-4][0-9]|25[0-5])\\.(?:[0-9]|[0-9]{2}|[0-1][0-9]{2}|2[0-4][0-9]|25[0-5"
    "])\\]).)*(?:[A-Za-z](?:[A-Za-z]|[0-9]|-)+(?:[A-Za-z]|[0-9])|#[0-9]+|\\"
    "[(?:[0-9]|[0-9]{2}|[0-1][0-9]{2}|2[0-4][0-9]|25[0-5])\\.(?:[0-9]|[0-9]"
    "{2}|[0-1][0-9]{2}|2[0-4][0-9]|25[0-5])\\.(?:[0-9]|[0-9]{2}|[0-1][0-9]{"
    "2}|2[0-4][0-9]|25[0-5])\\.(?:[0-9]|[0-9]{2}|[0-1][0-9]{2}|2[0-4][0-9]|"
    "25[0-5])\\])"

    ")$", domain);
    return rc;
}

static int helo_rfc1035domain(char *msg, char **domain)
{
    int rc;

    rc = str_parse(msg,
            "^.+ ("
    /*
     ##
     ##  The mega Perl regular expression below is generated
     ##  with the following Perl program. This is only possible
     ##  because the given grammar is Chomsky-3 (right or left
     ##  linear grammar, but noth both).
     ##

     # BNF grammar for <domain> according to RFC1035:
     # <letter>      ::= any one of the 52 alphabetic characters A through Z in upper case and a through z in lower case
     # <digit>       ::= any one of the ten digits 0 through 9
     # <let-dig>     ::= <letter> | <digit>
     # <let-dig-hyp> ::= <let-dig> | "-"
     # <ldh-str>     ::= <let-dig-hyp> | <let-dig-hyp> <ldh-str>
     # <label>       ::= <letter> [ [ <ldh-str> ] <let-dig> ]
     # <subdomain>   ::= <label> | <subdomain> "." <label>
     # <domain>      ::= <subdomain> | " "
     #
     # corresponding Perl regular expression ($domain)
     $letter      = "[A-Za-z]";
     $digit       = "[0-9]";
     $let_dig     = "(?:$letter|$digit)";
     $let_dig_hyp = "(?:$let_dig|-)";
     $ldh_str     = "${let_dig_hyp}+";
     $label       = "(?:$letter(?:(?:$ldh_str)?$let_dig)?)";
     $subdomain   = "(?:$label\.)*$label";
     $domain      = "(?:$subdomain| )";
     #
     # translate into C string block suitable for passing to the Perl
     # Compatible Regular Expressions (PCRE) based string library Str.
     my $cregex = $domain;
     $cregex .= "\n";
     $cregex =~ s|\\|\\\\|sg;
     $cregex =~ s|(.{17})|$1\n|sg;
     $cregex =~ s|([^\n]+)\n|"$1"\n|sg;
     $cregex =~ s|\n\n|\n|sg;
     print "$cregex";
     */

    "(?:(?:(?:[A-Za-z](?:(?:(?:(?:[A-Za-z]|[0-9])|-)+)?(?:[A-Za-z]|[0-9]))?"
    ").)*(?:[A-Za-z](?:(?:(?:(?:[A-Za-z]|[0-9])|-)+)?(?:[A-Za-z]|[0-9]))?)|"
    " )"

    ")$", domain);
    return rc;
}

static lmtp_rc_t lmtp_cb_mail(lmtp_t *lmtp, lmtp_io_t *io, lmtp_req_t *req, void *_ctx)
{
    lmtp2nntp_t *ctx = (lmtp2nntp_t *)_ctx;
    lmtp_rc_t    rc;
    lmtp_res_t   res;

    logbook(ctx->l2, L2_LEVEL_INFO, "LMTP service executing MAIL command < %s", req->msg);

    /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   553 Requested action not taken: mailbox name not allowed
     *  RFC1893 2. Status Codes                         5.X.X   Permanent Failure
     *  RFC1893 3.5 Network and Routing Status          X.1.8   Bad sender's system address
     */
    logbook(ctx->l2, L2_LEVEL_TRACE, "checking for previous LHLO");
    if (!ctx->session.lhlo_seen) {
        res.statuscode = "553";
        res.dsncode    = "5.1.8";
        res.statusmsg  = "friendly people say LHLO to open a transmission channel.";
        CU(LMTP_OK);
    }

    /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   503 Bad sequence of commands
     *  RFC1893 2. Status Codes                         5.X.X   Permanent Failure
     *  RFC1893 3.5 Network and Routing Status          X.5.0   Other or undefined protocol status
     */
    logbook(ctx->l2, L2_LEVEL_TRACE, "checking for previous MAIL");
    if (ctx->msg != NULL) {
        res.statuscode = "503";
        res.dsncode    = "5.5.0";
        res.statusmsg  = "Sender already specified.";
        CU(LMTP_OK);
    }

    /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   452 Requested action not taken: insufficient system storage
     *  RFC1893 2. Status Codes                         4.X.X   Persistent Transient Failure
     *  RFC1893 3.5 Network and Routing Status          X.3.1   Mail system full
     */
    logbook(ctx->l2, L2_LEVEL_TRACE, "msg_create");
    ctx->msgcount++;
    if ((ctx->msg = msg_create(ctx->prival)) == NULL) {
        res.statuscode = "452";
        res.dsncode    = "4.3.1";
        res.statusmsg  = "Internal error - memory.";
        CU(LMTP_ERR_MEM);
    }
    ctx->msg->l2 = ctx->l2;

    /*  RFC1652 2. Framework for the 8bit MIME Transport Extension
     *  (4)  one optional parameter using the keyword BODY is added to the MAIL
     *  FROM command.  The value associated with this parameter is a keyword
     *  indicating whether a 7bit message [...] or a MIME message [...] is
     *  being sent. The syntax of the value is as follows, using the ABNF
     *  notation [...]
     *
     *  body-value ::= "7BIT" / "8BITMIME"
     *
     *  "MAIL From:<foo@bar>"
     *  "MAIL From:<foo@bar> BODY=8BITMIME"
     *  "MAIL From:<foo@bar> BODY=7BIT"
     *
     *  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   553 Requested action not taken: mailbox name not allowed
     *  RFC1893 2. Status Codes                         5.X.X   Permanent Failure
     *  RFC1893 3.5 Network and Routing Status          X.1.7   Bad sender's mailbox address syntax
     */
    logbook(ctx->l2, L2_LEVEL_TRACE, "checking if sender address is a domain name");
    if (str_parse(req->msg, "m/^MAIL From:\\s*<(?:.+@.+)>/i") <= 0) {
        res.statuscode = "553";
        res.dsncode    = "5.1.7";
        res.statusmsg  = "Domain name required for sender address.";
        CU(LMTP_OK);
    }
    /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   501 Syntax error in parameters or arguments
     *  RFC1893 2. Status Codes                         5.X.X   Permanent Failure
     *  RFC1893 3.5 Network and Routing Status          X.5.4   Invalid command arguments
     */
    logbook(ctx->l2, L2_LEVEL_TRACE, "checking BODY keyword");
    if (str_parse(req->msg, "m/^MAIL From:\\s*<(.+@.+)>"
                            "(?:\\s+BODY=(?:7BIT|8BITMIME)\\s*)?$/i",
                            &ctx->msg->mail_from) <= 0) {
        res.statuscode = "501";
        res.dsncode    = "5.5.4";
        res.statusmsg  = "Unknown parameter for keyword BODY.";
        CU(LMTP_OK);
    }

    /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   550 Requested action not taken: mailbox unavailable
     *  RFC1893 2. Status Codes                         5.X.X   Permanent Failure
     *  RFC1893 3.5 Network and Routing Status          X.7.1   Delivery not authorized, message refused
     */
    logbook(ctx->l2, L2_LEVEL_TRACE, "checking if sender is allowed");
    if (ctx->option_mailfrom != NULL) {
        logbook(ctx->l2, L2_LEVEL_TRACE, "\"%s\" matching against \"%s\"", ctx->msg->mail_from, ctx->option_mailfrom);
        if (str_parse(ctx->msg->mail_from, ctx->option_mailfrom) <= 0) {
            res.statuscode = "550";
            res.dsncode    = "5.7.1";
            res.statusmsg  = "Delivery not authorized, message refused.";
            CU(LMTP_OK);
        }
    }

    /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   250 Requested mail action okay, completed
     *  RFC1893 2. Status Codes                         2.X.X   Success
     *  RFC1893 3.5 Network and Routing Status          X.1.0   Other address status
     */
    res.statuscode = "250";
    res.dsncode    = "2.1.0";
    res.statusmsg  = "Sender ok.";
    lmtp_response(lmtp, &res);
    return LMTP_OK;

    CUS:
    lmtp_response(lmtp, &res);
    if (ctx->msg != NULL) {
        msg_destroy(ctx->msg);
        ctx->msg = NULL;
    }
    return rc;
}

static lmtp_rc_t lmtp_cb_rcpt(lmtp_t *lmtp, lmtp_io_t *io, lmtp_req_t *req, void *_ctx)
{
    lmtp_res_t   res;
    lmtp_rc_t    rc;
    lmtp2nntp_t *ctx = (lmtp2nntp_t *)_ctx;
    char        *cp = NULL;
    char        *group;

    logbook(ctx->l2, L2_LEVEL_INFO, "LMTP service executing RCPT command < %s", req->msg);

    /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   503 Bad sequence of commands
     *  RFC1893 2. Status Codes                         5.X.X   Permanent Failure
     *  RFC1893 3.5 Network and Routing Status          X.5.0   Other or undefined protocol status
     */
    logbook(ctx->l2, L2_LEVEL_TRACE, "checking for previous MAIL");
    if ((ctx->msg == NULL) || (ctx->msg->mail_from == NULL)) {
        res.statuscode = "503";
        res.dsncode    = "5.5.0";
        res.statusmsg  = "specify sender with MAIL first.";
        CU(LMTP_OK);
    }

    /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   501 Syntax error in parameters or arguments
     *  RFC1893 2. Status Codes                         5.X.X   Permanent Failure
     *  RFC1893 3.5 Network and Routing Status          X.5.2   Syntax error
     */
    logbook(ctx->l2, L2_LEVEL_TRACE, "checking parameter syntax");
    if (str_parse(req->msg, "m/^RCPT To:\\s*(.+)$/i", &cp) <= 0) {
        res.statuscode = "501";
        res.dsncode    = "5.5.2";
        res.statusmsg  = "Syntax error in parameters.";
        CU(LMTP_OK);
    }

    /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   550 Requested action not taken: mailbox unavailable
     *  RFC1893 2. Status Codes                         5.X.X   Permanent Failure
     *  RFC1893 3.5 Network and Routing Status          X.1.1   Bad destination mailbox address
     */
    logbook(ctx->l2, L2_LEVEL_TRACE, "checking for empty parameter");
    if ((cp == NULL) || (strlen(cp) == 0)) {
        res.statuscode = "550";
        res.dsncode    = "5.1.1";
        res.statusmsg  = "empty Recipient/ Group.";
        CU(LMTP_OK);
    }

    /* in GROUPMODE = ARG|HEADER recipient must be acknowledged and stored to
     * give proper pipelining responses.  in GROUPMODE = ENVELOPE recipient is
     * transformed into a group and matched against groupfilter. Only valid
     * groups are stored to give proper pipelining responses.
     *
     *  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   550 Requested action not taken: mailbox unavailable
     *  RFC1893 2. Status Codes                         5.X.X   Permanent Failure
     *  RFC1893 3.5 Network and Routing Status          X.1.1   Bad destination mailbox address
     *                                                  X.7.2   Mailing list expansion prohibited
     */
    logbook(ctx->l2, L2_LEVEL_DEBUG, "ctx->option_groupmode=%d", ctx->option_groupmode);
    if (ctx->option_groupmode == GROUPMODE_ENVELOPE) {
        logbook(ctx->l2, L2_LEVEL_TRACE, "groupmode=envelope; transform recipient into group");
        if (str_parse(cp, "m/^<(.+)?@[^@]+>$/i", &group) <= 0) {
            res.statuscode = "550";
            res.dsncode    = "5.1.1";
            res.statusmsg  = "Recipient did not transform into group.";
            CU(LMTP_OK);
        }
        logbook(ctx->l2, L2_LEVEL_TRACE, "groupmode=envelope; match group %s", group);
        if (!groupmatch(ctx->azGroupargs, ctx->asGroupargs, group)) {
            res.statuscode = "550";
            res.dsncode    = "5.7.2";
            res.statusmsg  = "unmatched Group.";
            CU(LMTP_OK);
        }
        logbook(ctx->l2, L2_LEVEL_TRACE, "memorize group %s", group);
        argz_add(&ctx->msg->azEnvgroups, &ctx->msg->asEnvgroups, group);
    }
    logbook(ctx->l2, L2_LEVEL_TRACE, "memorize recipient %s", cp);
    argz_add(&ctx->msg->azRcpt, &ctx->msg->asRcpt, cp);

    /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   250 Requested mail action okay, completed
     *  RFC1893 2. Status Codes                         2.X.X   Success
     *  RFC1893 3.5 Network and Routing Status          X.1.5   Destination address valid
     */
    res.statuscode = "250";
    res.dsncode    = "2.1.5";
    res.statusmsg  = ctx->option_groupmode == GROUPMODE_ENVELOPE ? "Group accepted." : "Recipient accepted.";
    CU(LMTP_OK);

    CUS:
    if (cp != NULL)
        free(cp);
    lmtp_response(lmtp, &res);
    return rc;
}

int groupmatch(char *azPattern, size_t asPattern, char *cpGroup)
{
    int bGroupmatch;
    char *cpGroupmatch;

    bGroupmatch = FALSE;
    cpGroupmatch = NULL;
    while ((cpGroupmatch = argz_next(azPattern, asPattern, cpGroupmatch)) != NULL) {
        if (shpat_match(cpGroupmatch, cpGroup, 0) == 0)
            bGroupmatch = TRUE;
    }
    return bGroupmatch;
}

static lmtp_rc_t lmtp_cb_data(lmtp_t *lmtp, lmtp_io_t *io, lmtp_req_t *req, void *_ctx)
{
    lmtp2nntp_t *ctx = (lmtp2nntp_t *)_ctx;
    lmtp_rc_t    rc = LMTP_OK;
    lmtp_res_t   res;
    char        *azErr;
    size_t       asErr;
    char         errorstring[STDSTRLEN];
    char        *rcpt;
    int          i;
    int          bSuccess;
    char        *cp;
    int          bOk;
    char        *cpRestrictheader;
    char        *cpRestrictvalue;

    logbook(ctx->l2, L2_LEVEL_INFO, "LMTP service executing DATA command < %s", req->msg);

    /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   503 Bad sequence of commands
     *  RFC1893 2. Status Codes                         5.X.X   Permanent Failure
     *  RFC1893 3.5 Network and Routing Status          X.5.0   Other or undefined protocol status
     */
    logbook(ctx->l2, L2_LEVEL_TRACE, "checking for previous RCPT");
    if ((ctx->msg == NULL) || (argz_count(ctx->msg->azRcpt, ctx->msg->asRcpt) == 0)) {
        res.statuscode = "503";
        res.dsncode    = "5.5.0";
        res.statusmsg  = "specify recipient with RCPT first.";
        lmtp_response(lmtp, &res);
        return LMTP_OK;
    }

    /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   354 Start mail input; end with <CRLF>.<CRLF>
     */
    logbook(ctx->l2, L2_LEVEL_TRACE, "tell remote to send message now");
    res.statuscode = "354";
    res.dsncode    = NULL; /* DSN not used for data */
    res.statusmsg  = "Enter mail, end with \".\" on a line by itself";
    lmtp_response(lmtp, &res);

    logbook(ctx->l2, L2_LEVEL_TRACE, "read message with maximum size to accept = %d", ctx->option_maxmessagesize);
    rc = lmtp_readmsg(lmtp, &ctx->msg->cpMsg, ctx->option_maxmessagesize);

    /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   552 Requested mail action aborted: exceeded storage allocation
     *  RFC1893 2. Status Codes                         5.X.X   Permanent Failure
     *  RFC1893 3.5 Network and Routing Status          X.2.3   Message length exceeds administrative limit.
     */
    logbook(ctx->l2, L2_LEVEL_TRACE, "checking for excessive message size");
    if (rc == LMTP_ERR_OVERFLOW) {
        str_format(errorstring, sizeof(errorstring), "Message length exceeds administrative limit. %s", lmtp_error(rc));
        res.statuscode = "552";
        res.dsncode    = "5.2.3";
        res.statusmsg  = errorstring;
        rcpt = NULL;
        while ((rcpt = argz_next(ctx->msg->azRcpt, ctx->msg->asRcpt, rcpt)) != NULL) {
            lmtp_response(lmtp, &res);
        }
        return LMTP_OK;
    }

    /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   451 Requested action aborted: local error in processing
     *  RFC1893 2. Status Codes                         4.X.X   Persistent Transient Failure
     *  RFC1893 3.5 Network and Routing Status          X.3.2   System not accepting network messages
     */
    logbook(ctx->l2, L2_LEVEL_TRACE, "checking for system error");
    if (rc == LMTP_ERR_SYSTEM) {
        str_format(errorstring, sizeof(errorstring), "System error reading message: %s", strerror(errno));
        res.statuscode = "451";
        res.dsncode    = "4.3.2";
        res.statusmsg  = errorstring;
        rcpt = NULL;
        while ((rcpt = argz_next(ctx->msg->azRcpt, ctx->msg->asRcpt, rcpt)) != NULL) {
            lmtp_response(lmtp, &res);
        }
        return LMTP_OK;
    }

    /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   451 Requested action aborted: local error in processing
     *  RFC1893 2. Status Codes                         4.X.X   Persistent Transient Failure
     *  RFC1893 3.5 Network and Routing Status          X.3.2   System not accepting network messages
     */
    logbook(ctx->l2, L2_LEVEL_TRACE, "checking for other error");
    if(rc != LMTP_OK) {
        str_format(errorstring, sizeof(errorstring), "Unknown error reading message: %s", lmtp_error(rc));
        res.statuscode = "451";
        res.dsncode    = "4.3.2";
        res.statusmsg  = errorstring;
        rcpt = NULL;
        while ((rcpt = argz_next(ctx->msg->azRcpt, ctx->msg->asRcpt, rcpt)) != NULL) {
            lmtp_response(lmtp, &res);
        }
        return LMTP_OK;
    }

    /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   554 Transaction failed
     *  RFC1893 2. Status Codes                         5.X.X   Permanent Failure
     *  RFC1893 3.5 Network and Routing Status          X.6.5   Conversion Failed
     */
    logbook(ctx->l2, L2_LEVEL_TRACE, "split message");
    if ((rc = msg_split(ctx->msg)) != MSG_OK) {
        str_format(errorstring, sizeof(errorstring), "Error splitting message: %s", msg_error(rc));
        res.statuscode = "554";
        res.dsncode    = "5.6.5";
        res.statusmsg  = errorstring;
        rcpt = NULL;
        while ((rcpt = argz_next(ctx->msg->azRcpt, ctx->msg->asRcpt, rcpt)) != NULL) {
            lmtp_response(lmtp, &res);
        }
        return LMTP_OK;
    }

    if      (ctx->option_groupmode == GROUPMODE_ENVELOPE) {
        if ((cp = malloc(ctx->msg->asEnvgroups + 1)) == NULL) {
            /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   452 Requested action not taken: insufficient system storage
             *  RFC1893 2. Status Codes                         4.X.X   Persistent Transient Failure
             *  RFC1893 3.5 Network and Routing Status          X.3.1   Mail system full
             */
            ctx->msgcount++;
            if ((ctx->msg = msg_create(ctx->prival)) == NULL) {
                res.statuscode = "452";
                res.dsncode    = "4.3.1";
                res.statusmsg  = "Internal error - memory.";
                lmtp_response(lmtp, &res);
                return LMTP_ERR_MEM;
            }
        }
        ctx->msg->azNewsgroups = memcpy(cp, ctx->msg->azEnvgroups != NULL ? ctx->msg->azEnvgroups : "", ctx->msg->asEnvgroups);
        ctx->msg->asNewsgroups = ctx->msg->asEnvgroups;
    }
    else if (ctx->option_groupmode == GROUPMODE_ARG) {
        if ((cp = malloc(ctx->asGroupargs + 1)) == NULL) {
            /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   452 Requested action not taken: insufficient system storage
             *  RFC1893 2. Status Codes                         4.X.X   Persistent Transient Failure
             *  RFC1893 3.5 Network and Routing Status          X.3.1   Mail system full
             */
            ctx->msgcount++;
            if ((ctx->msg = msg_create(ctx->prival)) == NULL) {
                res.statuscode = "452";
                res.dsncode    = "4.3.1";
                res.statusmsg  = "Internal error - memory.";
                lmtp_response(lmtp, &res);
                return LMTP_ERR_MEM;
            }
        }
        ctx->msg->azNewsgroups = memcpy(cp, ctx->azGroupargs != NULL ? ctx->azGroupargs : "", ctx->asGroupargs);
        ctx->msg->asNewsgroups = ctx->asGroupargs;
    }
    else { /*                      == GROUPMODE_HEADER */
        cp = ctx->msg->azNewsgroups;
        while (cp != NULL) {
            if (!groupmatch(ctx->azGroupargs, ctx->asGroupargs, cp)) {
                if (argz_next(ctx->msg->azNewsgroups, ctx->msg->asNewsgroups, cp) == NULL) {
                    argz_delete(&ctx->msg->azNewsgroups, &ctx->msg->asNewsgroups, cp);
                    break;
                }
                else
                    argz_delete(&ctx->msg->azNewsgroups, &ctx->msg->asNewsgroups, cp);
            } else {
                cp = argz_next(ctx->msg->azNewsgroups, ctx->msg->asNewsgroups, cp);
            }
        }
        /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   550 Requested action not taken: mailbox unavailable
         *  RFC1893 2. Status Codes                         5.X.X   Permanent Failure
         *  RFC1893 3.5 Network and Routing Status          X.7.2   Mailing list expansion prohibited
         */
        if (ctx->msg->asNewsgroups == 0) {
            rcpt = NULL;
            while ((rcpt = argz_next(ctx->msg->azRcpt, ctx->msg->asRcpt, rcpt)) != NULL) {
                res.statuscode = "550";
                res.dsncode    = "5.7.2";
                res.statusmsg  = "Header did not match any valid group.";
                lmtp_response(lmtp, &res);
            }
            return LMTP_OK;
        }
    }

    /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   550 Requested action not taken: mailbox unavailable
     *  RFC1893 2. Status Codes                         5.X.X   Permanent Failure
     *  RFC1893 3.5 Network and Routing Status          X.7.1   Delivery not authorized, message refused
     */
    logbook(ctx->l2, L2_LEVEL_TRACE, "checking if restricted header causes reject");
    if (ctx->option_restrictheader != NULL) {
        bOk = FALSE;
        cp = NULL;
        while ((cp = argz_next(ctx->msg->azHeaders, ctx->msg->asHeaders, cp)) != NULL) {
            cpRestrictheader = cp;
            if ((cp = argz_next(ctx->msg->azHeaders, ctx->msg->asHeaders, cp)) == NULL)
                break;
            cpRestrictvalue = cp;
            str_format(errorstring, sizeof(errorstring), "%s %s", cpRestrictheader, cpRestrictvalue);
            if (str_parse(errorstring, ctx->option_restrictheader) <= 0) {
                logbook(ctx->l2, L2_LEVEL_TRACE, "\"%s\" matching against \"%s\" NO", errorstring, ctx->option_restrictheader);
            }
            else {
                logbook(ctx->l2, L2_LEVEL_TRACE, "\"%s\" matching against \"%s\": YES", errorstring, ctx->option_restrictheader);
                bOk = TRUE;
                break;
            }
        }
        if (bOk) {
            logbook(ctx->l2, L2_LEVEL_TRACE, "restricted header found");
            rcpt = NULL;
            while ((rcpt = argz_next(ctx->msg->azRcpt, ctx->msg->asRcpt, rcpt)) != NULL) {
                res.statuscode = "550";
                res.dsncode    = "5.7.1";
                res.statusmsg  = "Restricted header matched, message rejected.";
                lmtp_response(lmtp, &res);
            }
            return LMTP_OK;
        }
    }

    /* rewrite headers */
    logbook(ctx->l2, L2_LEVEL_TRACE, "appying header rewrite rules");
    msg_headermatrixbuildup(ctx->msg);
    headerrewrite(ctx);
    msg_headermatrixteardwn(ctx->msg);

    /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   554 Transaction failed
     *  RFC1893 2. Status Codes                         5.X.X   Permanent Failure
     *  RFC1893 3.5 Network and Routing Status          X.6.5   Conversion Failed
     */
    logbook(ctx->l2, L2_LEVEL_TRACE, "join message");
    if ((rc = msg_join(ctx->msg)) != MSG_OK) {
        str_format(errorstring, sizeof(errorstring), "Error joining message: %s", msg_error(rc));
        res.statuscode = "554";
        res.dsncode    = "5.6.5";
        res.statusmsg  = errorstring;
        rcpt = NULL;
        while ((rcpt = argz_next(ctx->msg->azRcpt, ctx->msg->asRcpt, rcpt)) != NULL) {
            lmtp_response(lmtp, &res);
        }
        return LMTP_OK;
    }

    logbook(ctx->l2, L2_LEVEL_TRACE, "deliver message");
    bSuccess = NNTP_ERR_DELIVERY; /* assume a hard error for the worst case */
    for (i = 0; i < ctx->nns; i++) {
        switch (ctx->option_operationmode) {
            case OPERATIONMODE_FAKE:
                ctx->pns[i].rc = NNTP_FAKE;
                break;
            case OPERATIONMODE_POST:
                if (ctx->pns[i].nntp)
                    ctx->pns[i].rc = nntp_post(ctx->pns[i].nntp, ctx->msg);
                break;
            case OPERATIONMODE_FEED:
                if (ctx->pns[i].nntp)
                    ctx->pns[i].rc = nntp_feed(ctx->pns[i].nntp, ctx->msg);
                break;
        }
        if (ctx->pns[i].rc == NNTP_OK)
            bSuccess = NNTP_OK;
        if (   bSuccess != NNTP_OK
            && (
                   (ctx->pns[i].rc == NNTP_ERR_SYSTEM)
                || (ctx->pns[i].rc == NNTP_DEFER)
                  )
              )
            bSuccess = NNTP_DEFER;
    }

    if (ctx->option_operationmode == OPERATIONMODE_FAKE) {
        str_format(errorstring, sizeof(errorstring),
                   "NNTP running in fake mode, delivery of %s [%d bytes] %s but delivery status forced to",
                   ctx->msg->cpMsgid,
                   strlen(ctx->msg->cpMsg),
                   ((bSuccess == NNTP_OK)    ? "succeeded" :
                    (bSuccess == NNTP_DEFER) ? "deferred"  : "failed"));
        switch (ctx->option_operationmodefakestatus[0]) {
            case '5':
                bSuccess = NNTP_ERR_UNKNOWN;
                logbook(ctx->l2, L2_LEVEL_NOTICE, "%s %s", errorstring, "failed");
                break;
            case '4':
                bSuccess = NNTP_DEFER;
                logbook(ctx->l2, L2_LEVEL_NOTICE, "%s %s", errorstring, "deferred");
                break;
            default:
                bSuccess = NNTP_OK;
                logbook(ctx->l2, L2_LEVEL_NOTICE, "%s %s", errorstring, "succeeded");
                break;
        }
    } else {
        str_format(errorstring, sizeof(errorstring), "%sdelivery of %s [%d bytes]",
                   ((ctx->option_operationmode == OPERATIONMODE_POST) ? "post " :
                   (ctx->option_operationmode == OPERATIONMODE_FEED) ? "feed " : ""),
                   ctx->msg->cpMsgid,
                   strlen(ctx->msg->cpMsg));
        if (bSuccess == NNTP_OK)
            logbook(ctx->l2, L2_LEVEL_NOTICE,  "%s %s", errorstring, "succeeded");
        else if(bSuccess == NNTP_DEFER)
            logbook(ctx->l2, L2_LEVEL_WARNING, "%s %s", errorstring, "deferred");
        else
            logbook(ctx->l2, L2_LEVEL_ERROR,   "%s %s", errorstring, "failed");
    }


    /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   250 Requested mail action okay, completed
     *                                                  451 Requested action aborted: local error in processing
     *                                                  554 Transaction failed
     *  RFC1893 2. Status Codes                         2.X.X   Success
     *                                                  4.X.X   Persistent Transient Failure
     *                                                  5.X.X   Permanent Failure
     *  RFC1893 3.5 Network and Routing Status          X.0.0   Other undefined Status
     *                                                  X.4.2   Bad connection
     */
    rcpt = NULL;
    while ((rcpt = argz_next(ctx->msg->azRcpt, ctx->msg->asRcpt, rcpt)) != NULL) {
        logbook(ctx->l2, L2_LEVEL_DEBUG, "ctx->option_operationmode=%d", ctx->option_operationmode);
        if (ctx->option_operationmode == OPERATIONMODE_FAKE) {
                    res.statuscode = ctx->option_operationmodefakestatus;
                    res.dsncode    = ctx->option_operationmodefakedsn;
                    str_format(errorstring, sizeof(errorstring),
                               "NNTP noop fake return for %s", rcpt);
        } else {
            switch (bSuccess) {
                case NNTP_OK:
                    str_format(errorstring, sizeof(errorstring),
                               "Message accepted for delivery to %s", rcpt);
                    res.statuscode = "250";
                    res.dsncode    = "2.0.0";
                    break;
                case NNTP_DEFER:
                    str_format(errorstring, sizeof(errorstring),
                               "Requested action aborted for %s, local error in processing.", rcpt);
                    res.statuscode = "451";
                    res.dsncode    = "4.4.2";
                    break;
                default:
                    str_format(errorstring, sizeof(errorstring),
                               "Error sending article for %s.", rcpt);
                    res.statuscode = "554";
                    res.dsncode    = "5.4.2";
                    break;
            }
        }
        azErr = NULL;
        asErr = 0;
        argz_add(&azErr, &asErr, errorstring);
        for (i = 0; i < ctx->nns; i++) {
            if (ctx->pns[i].rc != NNTP_OK) {
                var_rc_t var_rc;
                char *res_ptr;
                size_t res_len;
                str_format(errorstring, sizeof(errorstring),
                           "destination#%d ${option.destination[%d]} returned %s\n"
                           "destination#%d ${option.destination[%d]} lastresp \"%s\"",
                           i, i, nntp_error(ctx->pns[i].rc),
                           i, i, nntp_lastresp(ctx->pns[i].nntp));
                if ((var_rc = var_expand(ctx->config_varctx, errorstring, strlen(errorstring), &res_ptr, &res_len, FALSE)) != VAR_OK) {
                    str_format(errorstring, sizeof(errorstring),
                               "destination#%d returned %s\n"
                               "destination#%d lastresp \"%s\"",
                               i, nntp_error(ctx->pns[i].rc),
                               i, nntp_lastresp(ctx->pns[i].nntp));
                }
                else {
                    str_copy(errorstring, res_ptr, sizeof(errorstring) < res_len ? sizeof(errorstring) : res_len);
                    free(res_ptr);
                }
                argz_add(&azErr, &asErr, errorstring);
            }
        }
        if (azErr != NULL) {
            argz_stringify(azErr, asErr, '\n');
            res.statusmsg  = azErr;
            lmtp_response(lmtp, &res);
            free(azErr);
            azErr = NULL;
            asErr = 0;
        }
        else {
            res.statusmsg  = errorstring;
            lmtp_response(lmtp, &res);
        }
    }

    msg_destroy(ctx->msg);
    ctx->msg = NULL;

    return LMTP_OK;
}

static lmtp_rc_t lmtp_cb_noop(lmtp_t *lmtp, lmtp_io_t *io, lmtp_req_t *req, void *_ctx)
{
    lmtp2nntp_t *ctx = (lmtp2nntp_t *)_ctx;
    lmtp_res_t res;
    lmtp_rc_t rc = LMTP_OK;

    logbook(ctx->l2, L2_LEVEL_INFO, "LMTP service executing NOOP command < %s", req->msg);

    /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   250 Requested mail action okay, completed
     *  RFC1893 2. Status Codes                         2.X.X   Success
     *  RFC1893 3.5 Network and Routing Status          X.0.0   Other undefined Status
     */
    res.statuscode = "250";
    res.dsncode    = "2.0.0";
    res.statusmsg  = "OK. Nice talking to you.";
    lmtp_response(lmtp, &res);
    return rc;
}

static lmtp_rc_t lmtp_cb_rset(lmtp_t *lmtp, lmtp_io_t *io, lmtp_req_t *req, void *_ctx)
{
    lmtp2nntp_t *ctx = (lmtp2nntp_t *)_ctx;
    lmtp_res_t res;
    lmtp_rc_t rc = LMTP_OK;

    logbook(ctx->l2, L2_LEVEL_INFO, "LMTP service executing RSET command < %s", req->msg);

    lmtp_gfs_rset(ctx);

    /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   250 Requested mail action okay, completed
     *  RFC1893 2. Status Codes                         2.X.X   Success
     *  RFC1893 3.5 Network and Routing Status          X.0.0   Other undefined Status
     */
    res.statuscode = "250";
    res.dsncode    = "2.0.0";
    res.statusmsg  = "Reset state.";
    lmtp_response(lmtp, &res);
    return rc;
}

static void lmtp_gfs_rset(lmtp2nntp_t *ctx)
{
    logbook(ctx->l2, L2_LEVEL_TRACE, "LMTP service RSET command - graceful shutdown");

    if (ctx->msg != NULL) {
        msg_destroy(ctx->msg);
        ctx->msg = NULL;
    }
}

static lmtp_rc_t lmtp_cb_quit(lmtp_t *lmtp, lmtp_io_t *io, lmtp_req_t *req, void *_ctx)
{
    lmtp2nntp_t *ctx = (lmtp2nntp_t *)_ctx;
    lmtp_res_t res;
    lmtp_rc_t rc = LMTP_EOF;

    logbook(ctx->l2, L2_LEVEL_INFO, "LMTP service executing QUIT command < %s", req->msg);

    lmtp_gfs_quit(ctx);

    /*  RFC0821 4.2.1. REPLY CODES BY FUNCTION GROUPS   221 <domain> Service closing transmission channel
     *  RFC1893 2. Status Codes                         2.X.X   Success
     *  RFC1893 3.5 Network and Routing Status          X.0.0   Other undefined Status
     */
    res.statuscode = "221";
    res.dsncode    = "2.0.0";
    res.statusmsg  = "LMTP Service closing transmission channel.";
    lmtp_response(lmtp, &res);
    return rc;
}

static void lmtp_gfs_quit(lmtp2nntp_t *ctx)
{
    logbook(ctx->l2, L2_LEVEL_TRACE, "LMTP service QUIT command - graceful shutdown");

    lmtp_gfs_rset(ctx);
    resetsession(&ctx->session);
}