/*
 * 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.
 *
 */
/*
 * Copyright (c) 2016 by Delphix. All rights reserved.
 */
#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 they exist 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 their 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;
}