sendmail/src/savemail.c

	savemail.c revision e9af4bc0b1cc30cea75d6ad4aa2fde97d985e9be
/*
 * Copyright (c) 1998-2003, 2006 Sendmail, Inc. and its suppliers.
 *  All rights reserved.
 * Copyright (c) 1983, 1995-1997 Eric P. Allman.  All rights reserved.
 * Copyright (c) 1988, 1993
 *  The Regents of the University of California.  All rights reserved.
 *
 * By using this file, you agree to the terms and conditions set
 * forth in the LICENSE file which can be found at the top level of
 * the sendmail distribution.
 *
 */

#include <sendmail.h>

SM_RCSID("@(#)$Id: savemail.c,v 8.314 2009/12/18 17:08:01 ca Exp $")

static bool errbody __P((MCI *, ENVELOPE *, char *));
static bool pruneroute __P((char *));

/*
**  SAVEMAIL -- Save mail on error
**
**  If mailing back errors, mail it back to the originator
**  together with an error message; otherwise, just put it in
**  dead.letter in the user's home directory (if he exists on
**  this machine).
**
**  Parameters:
**      e -- the envelope containing the message in error.
**      sendbody -- if true, also send back the body of the
**          message; otherwise just send the header.
**
**  Returns:
**      true if savemail panic'ed, (i.e., the data file should
**      be preserved by dropenvelope())
**
**  Side Effects:
**      Saves the letter, by writing or mailing it back to the
**      sender, or by putting it in dead.letter in her home
**      directory.
*/

/* defines for state machine */
#define ESM_REPORT      0   /* report to sender's terminal */
#define ESM_MAIL        1   /* mail back to sender */
#define ESM_QUIET       2   /* mail has already been returned */
#define ESM_DEADLETTER      3   /* save in ~/dead.letter */
#define ESM_POSTMASTER      4   /* return to postmaster */
#define ESM_DEADLETTERDROP  5   /* save in DeadLetterDrop */
#define ESM_PANIC       6   /* call loseqfile() */
#define ESM_DONE        7   /* message is successfully delivered */

bool
savemail(e, sendbody)
    register ENVELOPE *e;
    bool sendbody;
{
    register SM_FILE_T *fp;
    bool panic = false;
    int state;
    auto ADDRESS *q = NULL;
    register char *p;
    MCI mcibuf;
    int flags;
    long sff;
    char buf[MAXLINE + 1];
    char dlbuf[MAXPATHLEN];
    SM_MBDB_T user;


    if (tTd(6, 1))
    {
        sm_dprintf("\nsavemail, errormode = %c, id = %s, ExitStat = %d\n  e_from=",
            e->e_errormode, e->e_id == NULL ? "NONE" : e->e_id,
            ExitStat);
        printaddr(sm_debug_file(), &e->e_from, false);
    }

    if (e->e_id == NULL)
    {
        /* can't return a message with no id */
        return panic;
    }

    /*
    **  In the unhappy event we don't know who to return the mail
    **  to, make someone up.
    */

    if (e->e_from.q_paddr == NULL)
    {
        e->e_sender = "Postmaster";
        if (parseaddr(e->e_sender, &e->e_from,
                  RF_COPYPARSE|RF_SENDERADDR,
                  '\0', NULL, e, false) == NULL)
        {
            syserr("553 5.3.5 Cannot parse Postmaster!");
            finis(true, true, EX_SOFTWARE);
        }
    }
    e->e_to = NULL;

    /*
    **  Basic state machine.
    **
    **  This machine runs through the following states:
    **
    **  ESM_QUIET   Errors have already been printed iff the
    **          sender is local.
    **  ESM_REPORT  Report directly to the sender's terminal.
    **  ESM_MAIL    Mail response to the sender.
    **  ESM_DEADLETTER  Save response in ~/dead.letter.
    **  ESM_POSTMASTER  Mail response to the postmaster.
    **  ESM_DEADLETTERDROP
    **          If DeadLetterDrop set, save it there.
    **  ESM_PANIC   Save response anywhere possible.
    */

    /* determine starting state */
    switch (e->e_errormode)
    {
      case EM_WRITE:
        state = ESM_REPORT;
        break;

      case EM_BERKNET:
      case EM_MAIL:
        state = ESM_MAIL;
        break;

      case EM_PRINT:
      case '\0':
        state = ESM_QUIET;
        break;

      case EM_QUIET:
        /* no need to return anything at all */
        return panic;

      default:
        syserr("554 5.3.0 savemail: bogus errormode x%x",
               e->e_errormode);
        state = ESM_MAIL;
        break;
    }

    /* if this is already an error response, send to postmaster */
    if (bitset(EF_RESPONSE, e->e_flags))
    {
        if (e->e_parent != NULL &&
            bitset(EF_RESPONSE, e->e_parent->e_flags))
        {
            /* got an error sending a response -- can it */
            return panic;
        }
        state = ESM_POSTMASTER;
    }

    while (state != ESM_DONE)
    {
        if (tTd(6, 5))
            sm_dprintf("  state %d\n", state);

        switch (state)
        {
          case ESM_QUIET:
            if (bitnset(M_LOCALMAILER, e->e_from.q_mailer->m_flags))
                state = ESM_DEADLETTER;
            else
                state = ESM_MAIL;
            break;

          case ESM_REPORT:

            /*
            **  If the user is still logged in on the same terminal,
            **  then write the error messages back to hir (sic).
            */

#if USE_TTYPATH
            p = ttypath();
#else /* USE_TTYPATH */
            p = NULL;
#endif /* USE_TTYPATH */

            if (p == NULL || sm_io_reopen(SmFtStdio,
                              SM_TIME_DEFAULT,
                              p, SM_IO_WRONLY, NULL,
                              smioout) == NULL)
            {
                state = ESM_MAIL;
                break;
            }

            expand("\201n", buf, sizeof(buf), e);
            (void) sm_io_fprintf(smioout, SM_TIME_DEFAULT,
                         "\r\nMessage from %s...\r\n", buf);
            (void) sm_io_fprintf(smioout, SM_TIME_DEFAULT,
                         "Errors occurred while sending mail.\r\n");
            if (e->e_xfp != NULL)
            {
                (void) bfrewind(e->e_xfp);
                (void) sm_io_fprintf(smioout, SM_TIME_DEFAULT,
                             "Transcript follows:\r\n");
                while (sm_io_fgets(e->e_xfp, SM_TIME_DEFAULT,
                           buf, sizeof(buf)) != NULL &&
                       !sm_io_error(smioout))
                    (void) sm_io_fputs(smioout,
                               SM_TIME_DEFAULT,
                               buf);
            }
            else
            {
                syserr("Cannot open %s",
                       queuename(e, XSCRPT_LETTER));
                (void) sm_io_fprintf(smioout, SM_TIME_DEFAULT,
                             "Transcript of session is unavailable.\r\n");
            }
            (void) sm_io_fprintf(smioout, SM_TIME_DEFAULT,
                         "Original message will be saved in dead.letter.\r\n");
            state = ESM_DEADLETTER;
            break;

          case ESM_MAIL:
            /*
            **  If mailing back, do it.
            **  Throw away all further output.  Don't alias,
            **  since this could cause loops, e.g., if joe
            **  mails to joe@x, and for some reason the network
            **  for @x is down, then the response gets sent to
            **  joe@x, which gives a response, etc.  Also force
            **  the mail to be delivered even if a version of
            **  it has already been sent to the sender.
            **
            **  If this is a configuration or local software
            **  error, send to the local postmaster as well,
            **  since the originator can't do anything
            **  about it anyway.  Note that this is a full
            **  copy of the message (intentionally) so that
            **  the Postmaster can forward things along.
            */

            if (ExitStat == EX_CONFIG || ExitStat == EX_SOFTWARE)
            {
                (void) sendtolist("postmaster", NULLADDR,
                          &e->e_errorqueue, 0, e);
            }
            if (!emptyaddr(&e->e_from))
            {
                char from[TOBUFSIZE];

                if (sm_strlcpy(from, e->e_from.q_paddr,
                        sizeof(from)) >= sizeof(from))
                {
                    state = ESM_POSTMASTER;
                    break;
                }

                if (!DontPruneRoutes)
                    (void) pruneroute(from);

                (void) sendtolist(from, NULLADDR,
                          &e->e_errorqueue, 0, e);
            }

            /*
            **  Deliver a non-delivery report to the
            **  Postmaster-designate (not necessarily
            **  Postmaster).  This does not include the
            **  body of the message, for privacy reasons.
            **  You really shouldn't need this.
            */

            e->e_flags |= EF_PM_NOTIFY;

            /* check to see if there are any good addresses */
            for (q = e->e_errorqueue; q != NULL; q = q->q_next)
            {
                if (QS_IS_SENDABLE(q->q_state))
                    break;
            }
            if (q == NULL)
            {
                /* this is an error-error */
                state = ESM_POSTMASTER;
                break;
            }
            if (returntosender(e->e_message, e->e_errorqueue,
                       sendbody ? RTSF_SEND_BODY
                            : RTSF_NO_BODY,
                       e) == 0)
            {
                state = ESM_DONE;
                break;
            }

            /* didn't work -- return to postmaster */
            state = ESM_POSTMASTER;
            break;

          case ESM_POSTMASTER:
            /*
            **  Similar to previous case, but to system postmaster.
            */

            q = NULL;
            expand(DoubleBounceAddr, buf, sizeof(buf), e);

            /*
            **  Just drop it on the floor if DoubleBounceAddr
            **  expands to an empty string.
            */

            if (*buf == '\0')
            {
                state = ESM_DONE;
                break;
            }
            if (sendtolist(buf, NULLADDR, &q, 0, e) <= 0)
            {
                syserr("553 5.3.0 cannot parse %s!", buf);
                ExitStat = EX_SOFTWARE;
                state = ESM_DEADLETTERDROP;
                break;
            }
            flags = RTSF_PM_BOUNCE;
            if (sendbody)
                flags |= RTSF_SEND_BODY;
            if (returntosender(e->e_message, q, flags, e) == 0)
            {
                state = ESM_DONE;
                break;
            }

            /* didn't work -- last resort */
            state = ESM_DEADLETTERDROP;
            break;

          case ESM_DEADLETTER:
            /*
            **  Save the message in dead.letter.
            **  If we weren't mailing back, and the user is
            **  local, we should save the message in
            **  ~/dead.letter so that the poor person doesn't
            **  have to type it over again -- and we all know
            **  what poor typists UNIX users are.
            */

            p = NULL;
            if (bitnset(M_HASPWENT, e->e_from.q_mailer->m_flags))
            {
                if (e->e_from.q_home != NULL)
                    p = e->e_from.q_home;
                else if (sm_mbdb_lookup(e->e_from.q_user, &user)
                     == EX_OK &&
                     *user.mbdb_homedir != '\0')
                    p = user.mbdb_homedir;
            }
            if (p == NULL || e->e_dfp == NULL)
            {
                /* no local directory or no data file */
                state = ESM_MAIL;
                break;
            }

            /* we have a home directory; write dead.letter */
            macdefine(&e->e_macro, A_TEMP, 'z', p);

            /* get the sender for the UnixFromLine */
            p = macvalue('g', e);
            macdefine(&e->e_macro, A_PERM, 'g', e->e_sender);

            expand("\201z/dead.letter", dlbuf, sizeof(dlbuf), e);
            sff = SFF_CREAT|SFF_REGONLY|SFF_RUNASREALUID;
            if (RealUid == 0)
                sff |= SFF_ROOTOK;
            e->e_to = dlbuf;
            if (writable(dlbuf, NULL, sff) &&
                mailfile(dlbuf, FileMailer, NULL, sff, e) == EX_OK)
            {
                int oldverb = Verbose;

                if (OpMode != MD_DAEMON && OpMode != MD_SMTP)
                    Verbose = 1;
                if (Verbose > 0)
                    message("Saved message in %s", dlbuf);
                Verbose = oldverb;
                macdefine(&e->e_macro, A_PERM, 'g', p);
                state = ESM_DONE;
                break;
            }
            macdefine(&e->e_macro, A_PERM, 'g', p);
            state = ESM_MAIL;
            break;

          case ESM_DEADLETTERDROP:
            /*
            **  Log the mail in DeadLetterDrop file.
            */

            if (e->e_class < 0)
            {
                state = ESM_DONE;
                break;
            }

            if ((SafeFileEnv != NULL && SafeFileEnv[0] != '\0') ||
                DeadLetterDrop == NULL ||
                DeadLetterDrop[0] == '\0')
            {
                state = ESM_PANIC;
                break;
            }

            sff = SFF_CREAT|SFF_REGONLY|SFF_ROOTOK|SFF_OPENASROOT|SFF_MUSTOWN;
            if (!writable(DeadLetterDrop, NULL, sff) ||
                (fp = safefopen(DeadLetterDrop, O_WRONLY|O_APPEND,
                        FileMode, sff)) == NULL)
            {
                state = ESM_PANIC;
                break;
            }

            memset(&mcibuf, '\0', sizeof(mcibuf));
            mcibuf.mci_out = fp;
            mcibuf.mci_mailer = FileMailer;
            if (bitnset(M_7BITS, FileMailer->m_flags))
                mcibuf.mci_flags |= MCIF_7BIT;

            /* get the sender for the UnixFromLine */
            p = macvalue('g', e);
            macdefine(&e->e_macro, A_PERM, 'g', e->e_sender);

            if (!putfromline(&mcibuf, e) ||
                !(*e->e_puthdr)(&mcibuf, e->e_header, e,
                    M87F_OUTER) ||
                !(*e->e_putbody)(&mcibuf, e, NULL) ||
                !putline("\n", &mcibuf) ||
                sm_io_flush(fp, SM_TIME_DEFAULT) == SM_IO_EOF ||
                sm_io_error(fp) ||
                sm_io_close(fp, SM_TIME_DEFAULT) < 0)
                state = ESM_PANIC;
            else
            {
                int oldverb = Verbose;

                if (OpMode != MD_DAEMON && OpMode != MD_SMTP)
                    Verbose = 1;
                if (Verbose > 0)
                    message("Saved message in %s",
                        DeadLetterDrop);
                Verbose = oldverb;
                if (LogLevel > 3)
                    sm_syslog(LOG_NOTICE, e->e_id,
                          "Saved message in %s",
                          DeadLetterDrop);
                state = ESM_DONE;
            }
            macdefine(&e->e_macro, A_PERM, 'g', p);
            break;

          default:
            syserr("554 5.3.5 savemail: unknown state %d", state);
            /* FALLTHROUGH */

          case ESM_PANIC:
            /* leave the locked queue & transcript files around */
            loseqfile(e, "savemail panic");
            panic = true;
            errno = 0;
            syserr("554 savemail: cannot save rejected email anywhere");
            state = ESM_DONE;
            break;
        }
    }
    return panic;
}
/*
**  RETURNTOSENDER -- return a message to the sender with an error.
**
**  Parameters:
**      msg -- the explanatory message.
**      returnq -- the queue of people to send the message to.
**      flags -- flags tweaking the operation:
**          RTSF_SENDBODY -- include body of message (otherwise
**              just send the header).
**          RTSF_PMBOUNCE -- this is a postmaster bounce.
**      e -- the current envelope.
**
**  Returns:
**      zero -- if everything went ok.
**      else -- some error.
**
**  Side Effects:
**      Returns the current message to the sender via mail.
*/

#define MAXRETURNS  6   /* max depth of returning messages */
#define ERRORFUDGE  1024    /* nominal size of error message text */

int
returntosender(msg, returnq, flags, e)
    char *msg;
    ADDRESS *returnq;
    int flags;
    register ENVELOPE *e;
{
    register ENVELOPE *ee;
    ENVELOPE *oldcur = CurEnv;
    ENVELOPE errenvelope;
    static int returndepth = 0;
    register ADDRESS *q;
    char *p;
    char buf[MAXNAME + 1];

    if (returnq == NULL)
        return -1;

    if (msg == NULL)
        msg = "Unable to deliver mail";

    if (tTd(6, 1))
    {
        sm_dprintf("\n*** Return To Sender: msg=\"%s\", depth=%d, e=%p, returnq=",
            msg, returndepth, e);
        printaddr(sm_debug_file(), returnq, true);
        if (tTd(6, 20))
        {
            sm_dprintf("Sendq=");
            printaddr(sm_debug_file(), e->e_sendqueue, true);
        }
    }

    if (++returndepth >= MAXRETURNS)
    {
        if (returndepth != MAXRETURNS)
            syserr("554 5.3.0 returntosender: infinite recursion on %s",
                   returnq->q_paddr);
        /* don't "unrecurse" and fake a clean exit */
        /* returndepth--; */
        return 0;
    }

    macdefine(&e->e_macro, A_PERM, 'g', e->e_sender);
    macdefine(&e->e_macro, A_PERM, 'u', NULL);

    /* initialize error envelope */
    ee = newenvelope(&errenvelope, e, sm_rpool_new_x(NULL));
    macdefine(&ee->e_macro, A_PERM, 'a', "\201b");
    macdefine(&ee->e_macro, A_PERM, 'r', "");
    macdefine(&ee->e_macro, A_PERM, 's', "localhost");
    macdefine(&ee->e_macro, A_PERM, '_', "localhost");
    clrsessenvelope(ee);

    ee->e_puthdr = putheader;
    ee->e_putbody = errbody;
    ee->e_flags |= EF_RESPONSE|EF_METOO;
    if (!bitset(EF_OLDSTYLE, e->e_flags))
        ee->e_flags &= ~EF_OLDSTYLE;
    if (bitset(EF_DONT_MIME, e->e_flags))
    {
        ee->e_flags |= EF_DONT_MIME;

        /*
        **  If we can't convert to MIME and we don't pass
        **  8-bit, we can't send the body.
        */

        if (bitset(EF_HAS8BIT, e->e_flags) &&
            !bitset(MM_PASS8BIT, MimeMode))
            flags &= ~RTSF_SEND_BODY;
    }

    ee->e_sendqueue = returnq;
    ee->e_msgsize = 0;
    if (bitset(RTSF_SEND_BODY, flags) &&
        !bitset(PRIV_NOBODYRETN, PrivacyFlags))
        ee->e_msgsize = ERRORFUDGE + e->e_msgsize;
    else
        ee->e_flags |= EF_NO_BODY_RETN;

    if (!setnewqueue(ee))
    {
        syserr("554 5.3.0 returntosender: cannot select queue for %s",
                   returnq->q_paddr);
        ExitStat = EX_UNAVAILABLE;
        returndepth--;
        return -1;
    }
    initsys(ee);

#if NAMED_BIND
    _res.retry = TimeOuts.res_retry[RES_TO_FIRST];
    _res.retrans = TimeOuts.res_retrans[RES_TO_FIRST];
#endif /* NAMED_BIND */
    for (q = returnq; q != NULL; q = q->q_next)
    {
        if (QS_IS_BADADDR(q->q_state))
            continue;

        q->q_flags &= ~(QHASNOTIFY|Q_PINGFLAGS);
        q->q_flags |= QPINGONFAILURE;

        if (!QS_IS_DEAD(q->q_state))
            ee->e_nrcpts++;

        if (q->q_alias == NULL)
            addheader("To", q->q_paddr, 0, ee, true);
    }

    if (LogLevel > 5)
    {
        if (bitset(EF_RESPONSE, e->e_flags))
            p = "return to sender";
        else if (bitset(EF_WARNING, e->e_flags))
            p = "sender notify";
        else if (bitset(RTSF_PM_BOUNCE, flags))
            p = "postmaster notify";
        else
            p = "DSN";
        sm_syslog(LOG_INFO, e->e_id, "%s: %s: %s",
              ee->e_id, p, shortenstring(msg, MAXSHORTSTR));
    }

    if (SendMIMEErrors)
    {
        addheader("MIME-Version", "1.0", 0, ee, true);
        (void) sm_snprintf(buf, sizeof(buf), "%s.%ld/%.100s",
                ee->e_id, (long)curtime(), MyHostName);
        ee->e_msgboundary = sm_rpool_strdup_x(ee->e_rpool, buf);
        (void) sm_snprintf(buf, sizeof(buf),
#if DSN
                "multipart/report; report-type=delivery-status;\n\tboundary=\"%s\"",
#else /* DSN */
                "multipart/mixed; boundary=\"%s\"",
#endif /* DSN */
                ee->e_msgboundary);
        addheader("Content-Type", buf, 0, ee, true);

        p = hvalue("Content-Transfer-Encoding", e->e_header);
        if (p != NULL && sm_strcasecmp(p, "binary") != 0)
            p = NULL;
        if (p == NULL && bitset(EF_HAS8BIT, e->e_flags))
            p = "8bit";
        if (p != NULL)
            addheader("Content-Transfer-Encoding", p, 0, ee, true);
    }
    if (strncmp(msg, "Warning:", 8) == 0)
    {
        addheader("Subject", msg, 0, ee, true);
        p = "warning-timeout";
    }
    else if (strncmp(msg, "Postmaster warning:", 19) == 0)
    {
        addheader("Subject", msg, 0, ee, true);
        p = "postmaster-warning";
    }
    else if (strcmp(msg, "Return receipt") == 0)
    {
        addheader("Subject", msg, 0, ee, true);
        p = "return-receipt";
    }
    else if (bitset(RTSF_PM_BOUNCE, flags))
    {
        (void) sm_snprintf(buf, sizeof(buf),
             "Postmaster notify: see transcript for details");
        addheader("Subject", buf, 0, ee, true);
        p = "postmaster-notification";
    }
    else
    {
        (void) sm_snprintf(buf, sizeof(buf),
             "Returned mail: see transcript for details");
        addheader("Subject", buf, 0, ee, true);
        p = "failure";
    }
    (void) sm_snprintf(buf, sizeof(buf), "auto-generated (%s)", p);
    addheader("Auto-Submitted", buf, 0, ee, true);

    /* fake up an address header for the from person */
    expand("\201n", buf, sizeof(buf), e);
    if (parseaddr(buf, &ee->e_from,
              RF_COPYALL|RF_SENDERADDR, '\0', NULL, e, false) == NULL)
    {
        syserr("553 5.3.5 Can't parse myself!");
        ExitStat = EX_SOFTWARE;
        returndepth--;
        return -1;
    }
    ee->e_from.q_flags &= ~(QHASNOTIFY|Q_PINGFLAGS);
    ee->e_from.q_flags |= QPINGONFAILURE;
    ee->e_sender = ee->e_from.q_paddr;

    /* push state into submessage */
    CurEnv = ee;
    macdefine(&ee->e_macro, A_PERM, 'f', "\201n");
    macdefine(&ee->e_macro, A_PERM, 'x', "Mail Delivery Subsystem");
    eatheader(ee, true, true);

    /* mark statistics */
    markstats(ee, NULLADDR, STATS_NORMAL);

    /* actually deliver the error message */
    sendall(ee, SM_DELIVER);

    /* restore state */
    (void) dropenvelope(ee, true, false);
    sm_rpool_free(ee->e_rpool);
    CurEnv = oldcur;
    returndepth--;

    /* check for delivery errors */
    if (ee->e_parent == NULL ||
        !bitset(EF_RESPONSE, ee->e_parent->e_flags))
        return 0;
    for (q = ee->e_sendqueue; q != NULL; q = q->q_next)
    {
        if (QS_IS_ATTEMPTED(q->q_state))
            return 0;
    }
    return -1;
}
/*
**  ERRBODY -- output the body of an error message.
**
**  Typically this is a copy of the transcript plus a copy of the
**  original offending message.
**
**  Parameters:
**      mci -- the mailer connection information.
**      e -- the envelope we are working in.
**      separator -- any possible MIME separator (unused).
**
**  Returns:
**      true iff body was written successfully
**
**  Side Effects:
**      Outputs the body of an error message.
*/

/* ARGSUSED2 */
static bool
errbody(mci, e, separator)
    register MCI *mci;
    register ENVELOPE *e;
    char *separator;
{
    bool printheader;
    bool sendbody;
    bool pm_notify;
    int save_errno;
    register SM_FILE_T *xfile;
    char *p;
    register ADDRESS *q = NULL;
    char actual[MAXLINE];
    char buf[MAXLINE];

    if (bitset(MCIF_INHEADER, mci->mci_flags))
    {
        if (!putline("", mci))
            goto writeerr;
        mci->mci_flags &= ~MCIF_INHEADER;
    }
    if (e->e_parent == NULL)
    {
        syserr("errbody: null parent");
        if (!putline("   ----- Original message lost -----\n", mci))
            goto writeerr;
        return true;
    }

    /*
    **  Output MIME header.
    */

    if (e->e_msgboundary != NULL)
    {
        (void) sm_strlcpyn(buf, sizeof(buf), 2, "--", e->e_msgboundary);
        if (!putline("This is a MIME-encapsulated message", mci) ||
            !putline("", mci) ||
            !putline(buf, mci) ||
            !putline("", mci))
            goto writeerr;
    }

    /*
    **  Output introductory information.
    */

    pm_notify = false;
    p = hvalue("subject", e->e_header);
    if (p != NULL && strncmp(p, "Postmaster ", 11) == 0)
        pm_notify = true;
    else
    {
        for (q = e->e_parent->e_sendqueue; q != NULL; q = q->q_next)
        {
            if (QS_IS_BADADDR(q->q_state))
                break;
        }
    }
    if (!pm_notify && q == NULL &&
        !bitset(EF_FATALERRS|EF_SENDRECEIPT, e->e_parent->e_flags))
    {
        if (!putline("    **********************************************",
            mci) ||
            !putline("    **      THIS IS A WARNING MESSAGE ONLY      **",
            mci) ||
            !putline("    **  YOU DO NOT NEED TO RESEND YOUR MESSAGE  **",
            mci) ||
            !putline("    **********************************************",
            mci) ||
            !putline("", mci))
            goto writeerr;
    }
    (void) sm_snprintf(buf, sizeof(buf),
        "The original message was received at %s",
        arpadate(ctime(&e->e_parent->e_ctime)));
    if (!putline(buf, mci))
        goto writeerr;
    expand("from \201_", buf, sizeof(buf), e->e_parent);
    if (!putline(buf, mci))
        goto writeerr;

    /* include id in postmaster copies */
    if (pm_notify && e->e_parent->e_id != NULL)
    {
        (void) sm_strlcpyn(buf, sizeof(buf), 2, "with id ",
            e->e_parent->e_id);
        if (!putline(buf, mci))
            goto writeerr;
    }
    if (!putline("", mci))
        goto writeerr;

    /*
    **  Output error message header (if specified and available).
    */

    if (ErrMsgFile != NULL &&
        !bitset(EF_SENDRECEIPT, e->e_parent->e_flags))
    {
        if (*ErrMsgFile == '/')
        {
            long sff = SFF_ROOTOK|SFF_REGONLY;

            if (DontLockReadFiles)
                sff |= SFF_NOLOCK;
            if (!bitnset(DBS_ERRORHEADERINUNSAFEDIRPATH,
                     DontBlameSendmail))
                sff |= SFF_SAFEDIRPATH;
            xfile = safefopen(ErrMsgFile, O_RDONLY, 0444, sff);
            if (xfile != NULL)
            {
                while (sm_io_fgets(xfile, SM_TIME_DEFAULT, buf,
                           sizeof(buf)) != NULL)
                {
                    int lbs;
                    bool putok;
                    char *lbp;

                    lbs = sizeof(buf);
                    lbp = translate_dollars(buf, buf, &lbs);
                    expand(lbp, lbp, lbs, e);
                    putok = putline(lbp, mci);
                    if (lbp != buf)
                        sm_free(lbp);
                    if (!putok)
                        goto writeerr;
                }
                (void) sm_io_close(xfile, SM_TIME_DEFAULT);
                if (!putline("\n", mci))
                    goto writeerr;
            }
        }
        else
        {
            expand(ErrMsgFile, buf, sizeof(buf), e);
            if (!putline(buf, mci) || !putline("", mci))
                goto writeerr;
        }
    }

    /*
    **  Output message introduction
    */

    /* permanent fatal errors */
    printheader = true;
    for (q = e->e_parent->e_sendqueue; q != NULL; q = q->q_next)
    {
        if (!QS_IS_BADADDR(q->q_state) ||
            !bitset(QPINGONFAILURE, q->q_flags))
            continue;

        if (printheader)
        {
            if (!putline("   ----- The following addresses had permanent fatal errors -----",
                    mci))
                goto writeerr;
            printheader = false;
        }

        (void) sm_strlcpy(buf, shortenstring(q->q_paddr, MAXSHORTSTR),
                  sizeof(buf));
        if (!putline(buf, mci))
            goto writeerr;
        if (q->q_rstatus != NULL)
        {
            (void) sm_snprintf(buf, sizeof(buf),
                "    (reason: %s)",
                shortenstring(exitstat(q->q_rstatus),
                          MAXSHORTSTR));
            if (!putline(buf, mci))
                goto writeerr;
        }
        if (q->q_alias != NULL)
        {
            (void) sm_snprintf(buf, sizeof(buf),
                "    (expanded from: %s)",
                shortenstring(q->q_alias->q_paddr,
                          MAXSHORTSTR));
            if (!putline(buf, mci))
                goto writeerr;
        }
    }
    if (!printheader && !putline("", mci))
        goto writeerr;

    /* transient non-fatal errors */
    printheader = true;
    for (q = e->e_parent->e_sendqueue; q != NULL; q = q->q_next)
    {
        if (QS_IS_BADADDR(q->q_state) ||
            !bitset(QPRIMARY, q->q_flags) ||
            !bitset(QBYNDELAY, q->q_flags) ||
            !bitset(QDELAYED, q->q_flags))
            continue;

        if (printheader)
        {
            if (!putline("   ----- The following addresses had transient non-fatal errors -----",
                    mci))
                goto writeerr;
            printheader = false;
        }

        (void) sm_strlcpy(buf, shortenstring(q->q_paddr, MAXSHORTSTR),
                  sizeof(buf));
        if (!putline(buf, mci))
            goto writeerr;
        if (q->q_alias != NULL)
        {
            (void) sm_snprintf(buf, sizeof(buf),
                "    (expanded from: %s)",
                shortenstring(q->q_alias->q_paddr,
                          MAXSHORTSTR));
            if (!putline(buf, mci))
                goto writeerr;
        }
    }
    if (!printheader && !putline("", mci))
        goto writeerr;

    /* successful delivery notifications */
    printheader = true;
    for (q = e->e_parent->e_sendqueue; q != NULL; q = q->q_next)
    {
        if (QS_IS_BADADDR(q->q_state) ||
            !bitset(QPRIMARY, q->q_flags) ||
            bitset(QBYNDELAY, q->q_flags) ||
            bitset(QDELAYED, q->q_flags))
            continue;
        else if (bitset(QBYNRELAY, q->q_flags))
            p = "Deliver-By notify: relayed";
        else if (bitset(QBYTRACE, q->q_flags))
            p = "Deliver-By trace: relayed";
        else if (!bitset(QPINGONSUCCESS, q->q_flags))
            continue;
        else if (bitset(QRELAYED, q->q_flags))
            p = "relayed to non-DSN-aware mailer";
        else if (bitset(QDELIVERED, q->q_flags))
        {
            if (bitset(QEXPANDED, q->q_flags))
                p = "successfully delivered to mailing list";
            else
                p = "successfully delivered to mailbox";
        }
        else if (bitset(QEXPANDED, q->q_flags))
            p = "expanded by alias";
        else
            continue;

        if (printheader)
        {
            if (!putline("   ----- The following addresses had successful delivery notifications -----",
                    mci))
                goto writeerr;
            printheader = false;
        }

        (void) sm_snprintf(buf, sizeof(buf), "%s  (%s)",
             shortenstring(q->q_paddr, MAXSHORTSTR), p);
        if (!putline(buf, mci))
            goto writeerr;
        if (q->q_alias != NULL)
        {
            (void) sm_snprintf(buf, sizeof(buf),
                "    (expanded from: %s)",
                shortenstring(q->q_alias->q_paddr,
                          MAXSHORTSTR));
            if (!putline(buf, mci))
                goto writeerr;
        }
    }
    if (!printheader && !putline("", mci))
        goto writeerr;

    /*
    **  Output transcript of errors
    */

    (void) sm_io_flush(smioout, SM_TIME_DEFAULT);
    if (e->e_parent->e_xfp == NULL)
    {
        if (!putline("   ----- Transcript of session is unavailable -----\n",
                mci))
            goto writeerr;
    }
    else
    {
        printheader = true;
        (void) bfrewind(e->e_parent->e_xfp);
        if (e->e_xfp != NULL)
            (void) sm_io_flush(e->e_xfp, SM_TIME_DEFAULT);
        while (sm_io_fgets(e->e_parent->e_xfp, SM_TIME_DEFAULT, buf,
                   sizeof(buf)) != NULL)
        {
            if (printheader && !putline("   ----- Transcript of session follows -----\n",
                        mci))
                goto writeerr;
            printheader = false;
            if (!putline(buf, mci))
                goto writeerr;
        }
    }
    errno = 0;

#if DSN
    /*
    **  Output machine-readable version.
    */

    if (e->e_msgboundary != NULL)
    {
        (void) sm_strlcpyn(buf, sizeof(buf), 2, "--", e->e_msgboundary);
        if (!putline("", mci) ||
            !putline(buf, mci) ||
            !putline("Content-Type: message/delivery-status", mci) ||
            !putline("", mci))
            goto writeerr;

        /*
        **  Output per-message information.
        */

        /* original envelope id from MAIL FROM: line */
        if (e->e_parent->e_envid != NULL)
        {
            (void) sm_snprintf(buf, sizeof(buf),
                    "Original-Envelope-Id: %.800s",
                    xuntextify(e->e_parent->e_envid));
            if (!putline(buf, mci))
                goto writeerr;
        }

        /* Reporting-MTA: is us (required) */
        (void) sm_snprintf(buf, sizeof(buf),
                   "Reporting-MTA: dns; %.800s", MyHostName);
        if (!putline(buf, mci))
            goto writeerr;

        /* DSN-Gateway: not relevant since we are not translating */

        /* Received-From-MTA: shows where we got this message from */
        if (RealHostName != NULL)
        {
            /* XXX use $s for type? */
            if (e->e_parent->e_from.q_mailer == NULL ||
                (p = e->e_parent->e_from.q_mailer->m_mtatype) == NULL)
                p = "dns";
            (void) sm_snprintf(buf, sizeof(buf),
                    "Received-From-MTA: %s; %.800s",
                    p, RealHostName);
            if (!putline(buf, mci))
                goto writeerr;
        }

        /* Arrival-Date: -- when it arrived here */
        (void) sm_strlcpyn(buf, sizeof(buf), 2, "Arrival-Date: ",
                arpadate(ctime(&e->e_parent->e_ctime)));
        if (!putline(buf, mci))
            goto writeerr;

        /* Deliver-By-Date: -- when it should have been delivered */
        if (IS_DLVR_BY(e->e_parent))
        {
            time_t dbyd;

            dbyd = e->e_parent->e_ctime + e->e_parent->e_deliver_by;
            (void) sm_strlcpyn(buf, sizeof(buf), 2,
                    "Deliver-By-Date: ",
                    arpadate(ctime(&dbyd)));
            if (!putline(buf, mci))
                goto writeerr;
        }

        /*
        **  Output per-address information.
        */

        for (q = e->e_parent->e_sendqueue; q != NULL; q = q->q_next)
        {
            char *action;

            if (QS_IS_BADADDR(q->q_state))
            {
                /* RFC 1891, 6.2.6 (b) */
                if (bitset(QHASNOTIFY, q->q_flags) &&
                    !bitset(QPINGONFAILURE, q->q_flags))
                    continue;
                action = "failed";
            }
            else if (!bitset(QPRIMARY, q->q_flags))
                continue;
            else if (bitset(QDELIVERED, q->q_flags))
            {
                if (bitset(QEXPANDED, q->q_flags))
                    action = "delivered (to mailing list)";
                else
                    action = "delivered (to mailbox)";
            }
            else if (bitset(QRELAYED, q->q_flags))
                action = "relayed (to non-DSN-aware mailer)";
            else if (bitset(QEXPANDED, q->q_flags))
                action = "expanded (to multi-recipient alias)";
            else if (bitset(QDELAYED, q->q_flags))
                action = "delayed";
            else if (bitset(QBYTRACE, q->q_flags))
                action = "relayed (Deliver-By trace mode)";
            else if (bitset(QBYNDELAY, q->q_flags))
                action = "delayed (Deliver-By notify mode)";
            else if (bitset(QBYNRELAY, q->q_flags))
                action = "relayed (Deliver-By notify mode)";
            else
                continue;

            if (!putline("", mci))
                goto writeerr;

            /* Original-Recipient: -- passed from on high */
            if (q->q_orcpt != NULL)
            {
                (void) sm_snprintf(buf, sizeof(buf),
                        "Original-Recipient: %.800s",
                        q->q_orcpt);
                if (!putline(buf, mci))
                    goto writeerr;
            }

            /* Figure out actual recipient */
            actual[0] = '\0';
            if (q->q_user[0] != '\0')
            {
                if (q->q_mailer != NULL &&
                    q->q_mailer->m_addrtype != NULL)
                    p = q->q_mailer->m_addrtype;
                else
                    p = "rfc822";

                if (sm_strcasecmp(p, "rfc822") == 0 &&
                    strchr(q->q_user, '@') == NULL)
                {
                    (void) sm_snprintf(actual,
                               sizeof(actual),
                               "%s; %.700s@%.100s",
                               p, q->q_user,
                               MyHostName);
                }
                else
                {
                    (void) sm_snprintf(actual,
                               sizeof(actual),
                               "%s; %.800s",
                               p, q->q_user);
                }
            }

            /* Final-Recipient: -- the name from the RCPT command */
            if (q->q_finalrcpt == NULL)
            {
                /* should never happen */
                sm_syslog(LOG_ERR, e->e_id,
                      "returntosender: q_finalrcpt is NULL");

                /* try to fall back to the actual recipient */
                if (actual[0] != '\0')
                    q->q_finalrcpt = sm_rpool_strdup_x(e->e_rpool,
                                       actual);
            }

            if (q->q_finalrcpt != NULL)
            {
                (void) sm_snprintf(buf, sizeof(buf),
                           "Final-Recipient: %s",
                           q->q_finalrcpt);
                if (!putline(buf, mci))
                    goto writeerr;
            }

            /* X-Actual-Recipient: -- the real problem address */
            if (actual[0] != '\0' &&
                q->q_finalrcpt != NULL &&
                !bitset(PRIV_NOACTUALRECIPIENT, PrivacyFlags) &&
                strcmp(actual, q->q_finalrcpt) != 0)
            {
                (void) sm_snprintf(buf, sizeof(buf),
                           "X-Actual-Recipient: %s",
                           actual);
                if (!putline(buf, mci))
                    goto writeerr;
            }

            /* Action: -- what happened? */
            (void) sm_strlcpyn(buf, sizeof(buf), 2, "Action: ",
                action);
            if (!putline(buf, mci))
                goto writeerr;

            /* Status: -- what _really_ happened? */
            if (q->q_status != NULL)
                p = q->q_status;
            else if (QS_IS_BADADDR(q->q_state))
                p = "5.0.0";
            else if (QS_IS_QUEUEUP(q->q_state))
                p = "4.0.0";
            else
                p = "2.0.0";
            (void) sm_strlcpyn(buf, sizeof(buf), 2, "Status: ", p);
            if (!putline(buf, mci))
                goto writeerr;

            /* Remote-MTA: -- who was I talking to? */
            if (q->q_statmta != NULL)
            {
                if (q->q_mailer == NULL ||
                    (p = q->q_mailer->m_mtatype) == NULL)
                    p = "dns";
                (void) sm_snprintf(buf, sizeof(buf),
                        "Remote-MTA: %s; %.800s",
                        p, q->q_statmta);
                p = &buf[strlen(buf) - 1];
                if (*p == '.')
                    *p = '\0';
                if (!putline(buf, mci))
                    goto writeerr;
            }

            /* Diagnostic-Code: -- actual result from other end */
            if (q->q_rstatus != NULL)
            {
                if (q->q_mailer == NULL ||
                    (p = q->q_mailer->m_diagtype) == NULL)
                    p = "smtp";
                (void) sm_snprintf(buf, sizeof(buf),
                        "Diagnostic-Code: %s; %.800s",
                        p, q->q_rstatus);
                if (!putline(buf, mci))
                    goto writeerr;
            }

            /* Last-Attempt-Date: -- fine granularity */
            if (q->q_statdate == (time_t) 0L)
                q->q_statdate = curtime();
            (void) sm_strlcpyn(buf, sizeof(buf), 2,
                    "Last-Attempt-Date: ",
                    arpadate(ctime(&q->q_statdate)));
            if (!putline(buf, mci))
                goto writeerr;

            /* Will-Retry-Until: -- for delayed messages only */
            if (QS_IS_QUEUEUP(q->q_state))
            {
                time_t xdate;

                xdate = e->e_parent->e_ctime +
                    TimeOuts.to_q_return[e->e_parent->e_timeoutclass];
                (void) sm_strlcpyn(buf, sizeof(buf), 2,
                     "Will-Retry-Until: ",
                     arpadate(ctime(&xdate)));
                if (!putline(buf, mci))
                    goto writeerr;
            }
        }
    }
#endif /* DSN */

    /*
    **  Output text of original message
    */

    if (!putline("", mci))
        goto writeerr;
    if (bitset(EF_HAS_DF, e->e_parent->e_flags))
    {
        sendbody = !bitset(EF_NO_BODY_RETN, e->e_parent->e_flags) &&
               !bitset(EF_NO_BODY_RETN, e->e_flags);

        if (e->e_msgboundary == NULL)
        {
            if (!putline(
                sendbody
                ? "   ----- Original message follows -----\n"
                : "   ----- Message header follows -----\n",
                mci))
            {
                goto writeerr;
            }
        }
        else
        {
            (void) sm_strlcpyn(buf, sizeof(buf), 2, "--",
                    e->e_msgboundary);

            if (!putline(buf, mci))
                goto writeerr;
            (void) sm_strlcpyn(buf, sizeof(buf), 2, "Content-Type: ",
                    sendbody ? "message/rfc822"
                         : "text/rfc822-headers");
            if (!putline(buf, mci))
                goto writeerr;

            p = hvalue("Content-Transfer-Encoding",
                   e->e_parent->e_header);
            if (p != NULL && sm_strcasecmp(p, "binary") != 0)
                p = NULL;
            if (p == NULL &&
                bitset(EF_HAS8BIT, e->e_parent->e_flags))
                p = "8bit";
            if (p != NULL)
            {
                (void) sm_snprintf(buf, sizeof(buf),
                        "Content-Transfer-Encoding: %s",
                        p);
                if (!putline(buf, mci))
                    goto writeerr;
            }
        }
        if (!putline("", mci))
            goto writeerr;
        save_errno = errno;
        if (!putheader(mci, e->e_parent->e_header, e->e_parent,
                M87F_OUTER))
            goto writeerr;
        errno = save_errno;
        if (sendbody)
        {
            if (!putbody(mci, e->e_parent, e->e_msgboundary))
                goto writeerr;
        }
        else if (e->e_msgboundary == NULL)
        {
            if (!putline("", mci) ||
                !putline("   ----- Message body suppressed -----",
                    mci))
            {
                goto writeerr;
            }
        }
    }
    else if (e->e_msgboundary == NULL)
    {
        if (!putline("  ----- No message was collected -----\n", mci))
            goto writeerr;
    }

    if (e->e_msgboundary != NULL)
    {
        (void) sm_strlcpyn(buf, sizeof(buf), 3, "--", e->e_msgboundary,
                   "--");
        if (!putline("", mci) || !putline(buf, mci))
            goto writeerr;
    }
    if (!putline("", mci) ||
        sm_io_flush(mci->mci_out, SM_TIME_DEFAULT) == SM_IO_EOF)
            goto writeerr;

    /*
    **  Cleanup and exit
    */

    if (errno != 0)
    {
  writeerr:
        syserr("errbody: I/O error");
        return false;
    }
    return true;
}

/*
**  SMTPTODSN -- convert SMTP to DSN status code
**
**  Parameters:
**      smtpstat -- the smtp status code (e.g., 550).
**
**  Returns:
**      The DSN version of the status code.
**
**  Storage Management:
**      smtptodsn() returns a pointer to a character string literal,
**      which will remain valid forever, and thus does not need to
**      be copied.  Current code relies on this property.
*/

char *
smtptodsn(smtpstat)
    int smtpstat;
{
    if (smtpstat < 0)
        return "4.4.2";

    switch (smtpstat)
    {
      case 450: /* Req mail action not taken: mailbox unavailable */
        return "4.2.0";

      case 451: /* Req action aborted: local error in processing */
        return "4.3.0";

      case 452: /* Req action not taken: insufficient sys storage */
        return "4.3.1";

      case 500: /* Syntax error, command unrecognized */
        return "5.5.2";

      case 501: /* Syntax error in parameters or arguments */
        return "5.5.4";

      case 502: /* Command not implemented */
        return "5.5.1";

      case 503: /* Bad sequence of commands */
        return "5.5.1";

      case 504: /* Command parameter not implemented */
        return "5.5.4";

      case 550: /* Req mail action not taken: mailbox unavailable */
        return "5.2.0";

      case 551: /* User not local; please try <...> */
        return "5.1.6";

      case 552: /* Req mail action aborted: exceeded storage alloc */
        return "5.2.2";

      case 553: /* Req action not taken: mailbox name not allowed */
        return "5.1.0";

      case 554: /* Transaction failed */
        return "5.0.0";
    }

    if (REPLYTYPE(smtpstat) == 2)
        return "2.0.0";
    if (REPLYTYPE(smtpstat) == 4)
        return "4.0.0";
    return "5.0.0";
}
/*
**  XTEXTIFY -- take regular text and turn it into DSN-style xtext
**
**  Parameters:
**      t -- the text to convert.
**      taboo -- additional characters that must be encoded.
**
**  Returns:
**      The xtext-ified version of the same string.
*/

char *
xtextify(t, taboo)
    register char *t;
    char *taboo;
{
    register char *p;
    int l;
    int nbogus;
    static char *bp = NULL;
    static int bplen = 0;

    if (taboo == NULL)
        taboo = "";

    /* figure out how long this xtext will have to be */
    nbogus = l = 0;
    for (p = t; *p != '\0'; p++)
    {
        register int c = (*p & 0xff);

        /* ASCII dependence here -- this is the way the spec words it */
        if (c < '!' || c > '~' || c == '+' || c == '\\' || c == '(' ||
            strchr(taboo, c) != NULL)
            nbogus++;
        l++;
    }
    if (nbogus < 0)
    {
        /* since nbogus is ssize_t and wrapped, 2 * size_t would wrap */
        syserr("!xtextify string too long");
    }
    if (nbogus == 0)
        return t;
    l += nbogus * 2 + 1;

    /* now allocate space if necessary for the new string */
    if (l > bplen)
    {
        if (bp != NULL)
            sm_free(bp); /* XXX */
        bp = sm_pmalloc_x(l);
        bplen = l;
    }

    /* ok, copy the text with byte expansion */
    for (p = bp; *t != '\0'; )
    {
        register int c = (*t++ & 0xff);

        /* ASCII dependence here -- this is the way the spec words it */
        if (c < '!' || c > '~' || c == '+' || c == '\\' || c == '(' ||
            strchr(taboo, c) != NULL)
        {
            *p++ = '+';
            *p++ = "0123456789ABCDEF"[c >> 4];
            *p++ = "0123456789ABCDEF"[c & 0xf];
        }
        else
            *p++ = c;
    }
    *p = '\0';
    return bp;
}
/*
**  XUNTEXTIFY -- take xtext and turn it into plain text
**
**  Parameters:
**      t -- the xtextified text.
**
**  Returns:
**      The decoded text.  No attempt is made to deal with
**      null strings in the resulting text.
*/

char *
xuntextify(t)
    register char *t;
{
    register char *p;
    int l;
    static char *bp = NULL;
    static int bplen = 0;

    /* heuristic -- if no plus sign, just return the input */
    if (strchr(t, '+') == NULL)
        return t;

    /* xtext is always longer than decoded text */
    l = strlen(t);
    if (l > bplen)
    {
        if (bp != NULL)
            sm_free(bp); /* XXX */
        bp = xalloc(l);
        bplen = l;
    }

    /* ok, copy the text with byte compression */
    for (p = bp; *t != '\0'; t++)
    {
        register int c = *t & 0xff;

        if (c != '+')
        {
            *p++ = c;
            continue;
        }

        c = *++t & 0xff;
        if (!isascii(c) || !isxdigit(c))
        {
            /* error -- first digit is not hex */
            usrerr("bogus xtext: +%c", c);
            t--;
            continue;
        }
        if (isdigit(c))
            c -= '0';
        else if (isupper(c))
            c -= 'A' - 10;
        else
            c -= 'a' - 10;
        *p = c << 4;

        c = *++t & 0xff;
        if (!isascii(c) || !isxdigit(c))
        {
            /* error -- second digit is not hex */
            usrerr("bogus xtext: +%x%c", *p >> 4, c);
            t--;
            continue;
        }
        if (isdigit(c))
            c -= '0';
        else if (isupper(c))
            c -= 'A' - 10;
        else
            c -= 'a' - 10;
        *p++ |= c;
    }
    *p = '\0';
    return bp;
}
/*
**  XTEXTOK -- check if a string is legal xtext
**
**  Xtext is used in Delivery Status Notifications.  The spec was
**  taken from RFC 1891, ``SMTP Service Extension for Delivery
**  Status Notifications''.
**
**  Parameters:
**      s -- the string to check.
**
**  Returns:
**      true -- if 's' is legal xtext.
**      false -- if it has any illegal characters in it.
*/

bool
xtextok(s)
    char *s;
{
    int c;

    while ((c = *s++) != '\0')
    {
        if (c == '+')
        {
            c = *s++;
            if (!isascii(c) || !isxdigit(c))
                return false;
            c = *s++;
            if (!isascii(c) || !isxdigit(c))
                return false;
        }
        else if (c < '!' || c > '~' || c == '=')
            return false;
    }
    return true;
}
/*
**  PRUNEROUTE -- prune an RFC-822 source route
**
**  Trims down a source route to the last internet-registered hop.
**  This is encouraged by RFC 1123 section 5.3.3.
**
**  Parameters:
**      addr -- the address
**
**  Returns:
**      true -- address was modified
**      false -- address could not be pruned
**
**  Side Effects:
**      modifies addr in-place
*/

static bool
pruneroute(addr)
    char *addr;
{
#if NAMED_BIND
    char *start, *at, *comma;
    char c;
    int braclev;
    int rcode;
    int i;
    char hostbuf[BUFSIZ];
    char *mxhosts[MAXMXHOSTS + 1];

    /* check to see if this is really a route-addr */
    if (*addr != '<' || addr[1] != '@' || addr[strlen(addr) - 1] != '>')
        return false;

    /*
    **  Can't simply find the first ':' is the address might be in the
    **  form:  "<@[IPv6:::1]:user@host>" and the first ':' in inside
    **  the IPv6 address.
    */

    start = addr;
    braclev = 0;
    while (*start != '\0')
    {
        if (*start == ':' && braclev <= 0)
            break;
        else if (*start == '[')
            braclev++;
        else if (*start == ']' && braclev > 0)
            braclev--;
        start++;
    }
    if (braclev > 0 || *start != ':')
        return false;

    at = strrchr(addr, '@');
    if (at == NULL || at < start)
        return false;

    /* slice off the angle brackets */
    i = strlen(at + 1);
    if (i >= sizeof(hostbuf))
        return false;
    (void) sm_strlcpy(hostbuf, at + 1, sizeof(hostbuf));
    hostbuf[i - 1] = '\0';

    while (start != NULL)
    {
        if (getmxrr(hostbuf, mxhosts, NULL, false,
                &rcode, true, NULL) > 0)
        {
            (void) sm_strlcpy(addr + 1, start + 1,
                      strlen(addr) - 1);
            return true;
        }
        c = *start;
        *start = '\0';
        comma = strrchr(addr, ',');
        if (comma != NULL && comma[1] == '@' &&
            strlen(comma + 2) < sizeof(hostbuf))
            (void) sm_strlcpy(hostbuf, comma + 2, sizeof(hostbuf));
        else
            comma = NULL;
        *start = c;
        start = comma;
    }
#endif /* NAMED_BIND */
    return false;
}