source: trunk/third/sendmail/src/headers.c @ 12554

/*
 * Copyright (c) 1998 Sendmail, Inc.  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.
 *
 */

#ifndef lint
static char sccsid[] = "@(#)headers.c   8.136 (Berkeley) 1/26/1999";
#endif /* not lint */

# include <errno.h>
# include "sendmail.h"

/*
**  SETUPHEADERS -- initialize headers in symbol table
**
**      Parameters:
**              none
**
**      Returns:
**              none
*/

void
setupheaders()
{
        struct hdrinfo *hi;
        STAB *s;

        for (hi = HdrInfo; hi->hi_field != NULL; hi++)
        {
                s = stab(hi->hi_field, ST_HEADER, ST_ENTER);
                s->s_header.hi_flags = hi->hi_flags;
                s->s_header.hi_ruleset = NULL;
        }
}
/*
**  CHOMPHEADER -- process and save a header line.
**
**      Called by collect and by readcf to deal with header lines.
**
**      Parameters:
**              line -- header as a text line.
**              def -- if set, this is a default value.
**              hdrp -- a pointer to the place to save the header.
**              e -- the envelope including this header.
**
**      Returns:
**              flags for this header.
**
**      Side Effects:
**              The header is saved on the header list.
**              Contents of 'line' are destroyed.
*/

struct hdrinfo  NormalHeader =  { NULL, 0, NULL };

int
chompheader(line, def, hdrp, e)
        char *line;
        bool def;
        HDR **hdrp;
        register ENVELOPE *e;
{
        register char *p;
        register HDR *h;
        HDR **hp;
        char *fname;
        char *fvalue;
        bool cond = FALSE;
        bool headeronly;
        STAB *s;
        struct hdrinfo *hi;
        bool nullheader = FALSE;
        BITMAP mopts;

        if (tTd(31, 6))
        {
                printf("chompheader: ");
                xputs(line);
                printf("\n");
        }

        headeronly = hdrp != NULL;
        if (!headeronly)
                hdrp = &e->e_header;

        /* strip off options */
        clrbitmap(mopts);
        p = line;
        if (*p == '?')
        {
                /* have some */
                register char *q = strchr(p + 1, *p);
                
                if (q != NULL)
                {
                        *q++ = '\0';
                        while (*++p != '\0')
                                setbitn(*p, mopts);
                        p = q;
                }
                else
                        syserr("553 header syntax error, line \"%s\"", line);
                cond = TRUE;
        }

        /* find canonical name */
        fname = p;
        while (isascii(*p) && isgraph(*p) && *p != ':')
                p++;
        fvalue = p;
        while (isascii(*p) && isspace(*p))
                p++;
        if (*p++ != ':' || fname == fvalue)
        {
                syserr("553 header syntax error, line \"%s\"", line);
                return 0;
        }
        *fvalue = '\0';

        /* strip field value on front */
        if (*p == ' ')
                p++;
        fvalue = p;

        /* if the field is null, go ahead and use the default */
        while (isascii(*p) && isspace(*p))
                p++;
        if (*p == '\0')
                nullheader = TRUE;

        /* security scan: long field names are end-of-header */
        if (strlen(fname) > 100)
                return H_EOH;

        /* check to see if it represents a ruleset call */
        if (def)
        {
                char hbuf[50];

                (void) expand(fvalue, hbuf, sizeof hbuf, e);
                for (p = hbuf; isascii(*p) && isspace(*p); )
                        p++;
                if ((*p++ & 0377) == CALLSUBR)
                {
                        auto char *endp;

                        if (strtorwset(p, &endp, ST_ENTER) > 0)
                        {
                                *endp = '\0';
                                s = stab(fname, ST_HEADER, ST_ENTER);
                                s->s_header.hi_ruleset = newstr(p);
                        }
                        return 0;
                }
        }

        /* see if it is a known type */
        s = stab(fname, ST_HEADER, ST_FIND);
        if (s != NULL)
                hi = &s->s_header;
        else
                hi = &NormalHeader;

        if (tTd(31, 9))
        {
                if (s == NULL)
                        printf("no header flags match\n");
                else
                        printf("header match, flags=%x, ruleset=%s\n", 
                                hi->hi_flags,
                                hi->hi_ruleset == NULL ? "<NULL>" : hi->hi_ruleset);
        }

        /* see if this is a resent message */
        if (!def && !headeronly && bitset(H_RESENT, hi->hi_flags))
                e->e_flags |= EF_RESENT;

        /* if this is an Errors-To: header keep track of it now */
        if (UseErrorsTo && !def && !headeronly &&
            bitset(H_ERRORSTO, hi->hi_flags))
                (void) sendtolist(fvalue, NULLADDR, &e->e_errorqueue, 0, e);

        /* if this means "end of header" quit now */
        if (!headeronly && bitset(H_EOH, hi->hi_flags))
                return hi->hi_flags;

        /*
        **  Horrible hack to work around problem with Lotus Notes SMTP
        **  mail gateway, which generates From: headers with newlines in
        **  them and the <address> on the second line.  Although this is
        **  legal RFC 822, many MUAs don't handle this properly and thus
        **  never find the actual address.
        */

        if (bitset(H_FROM, hi->hi_flags) && SingleLineFromHeader)
        {
                while ((p = strchr(fvalue, '\n')) != NULL)
                        *p = ' ';
        }

        /*
        **  If there is a check ruleset, verify it against the header.
        */

        if (!def && hi->hi_ruleset != NULL)
                (void) rscheck(hi->hi_ruleset, fvalue, NULL, e);

        /*
        **  Drop explicit From: if same as what we would generate.
        **  This is to make MH (which doesn't always give a full name)
        **  insert the full name information in all circumstances.
        */

        p = "resent-from";
        if (!bitset(EF_RESENT, e->e_flags))
                p += 7;
        if (!def && !headeronly && !bitset(EF_QUEUERUN, e->e_flags) &&
            strcasecmp(fname, p) == 0)
        {
                if (tTd(31, 2))
                {
                        printf("comparing header from (%s) against default (%s or %s)\n",
                                fvalue, e->e_from.q_paddr, e->e_from.q_user);
                }
                if (e->e_from.q_paddr != NULL &&
                    (strcmp(fvalue, e->e_from.q_paddr) == 0 ||
                     strcmp(fvalue, e->e_from.q_user) == 0))
                        return hi->hi_flags;
        }

        /* delete default value for this header */
        for (hp = hdrp; (h = *hp) != NULL; hp = &h->h_link)
        {
                if (strcasecmp(fname, h->h_field) == 0 &&
                    bitset(H_DEFAULT, h->h_flags) &&
                    !bitset(H_FORCE, h->h_flags))
                {
                        if (nullheader)
                        {
                                /* user-supplied value was null */
                                return 0;
                        }
                        h->h_value = NULL;
                        if (!cond)
                        {
                                /* copy conditions from default case */
                                bcopy((char *)h->h_mflags, (char *)mopts,
                                                sizeof mopts);
                        }
                }
        }

        /* create a new node */
        h = (HDR *) xalloc(sizeof *h);
        h->h_field = newstr(fname);
        h->h_value = newstr(fvalue);
        h->h_link = NULL;
        bcopy((char *) mopts, (char *) h->h_mflags, sizeof mopts);
        *hp = h;
        h->h_flags = hi->hi_flags;

        /* strip EOH flag if parsing MIME headers */
        if (headeronly)
                h->h_flags &= ~H_EOH;
        if (def)
                h->h_flags |= H_DEFAULT;
        if (cond)
                h->h_flags |= H_CHECK;

        /* hack to see if this is a new format message */
        if (!def && !headeronly && bitset(H_RCPT|H_FROM, h->h_flags) &&
            (strchr(fvalue, ',') != NULL || strchr(fvalue, '(') != NULL ||
             strchr(fvalue, '<') != NULL || strchr(fvalue, ';') != NULL))
        {
                e->e_flags &= ~EF_OLDSTYLE;
        }

        return h->h_flags;
}
/*
**  ADDHEADER -- add a header entry to the end of the queue.
**
**      This bypasses the special checking of chompheader.
**
**      Parameters:
**              field -- the name of the header field.
**              value -- the value of the field.
**              hp -- an indirect pointer to the header structure list.
**
**      Returns:
**              none.
**
**      Side Effects:
**              adds the field on the list of headers for this envelope.
*/

void
addheader(field, value, hdrlist)
        char *field;
        char *value;
        HDR **hdrlist;
{
        register HDR *h;
        STAB *s;
        HDR **hp;

        /* find info struct */
        s = stab(field, ST_HEADER, ST_FIND);

        /* find current place in list -- keep back pointer? */
        for (hp = hdrlist; (h = *hp) != NULL; hp = &h->h_link)
        {
                if (strcasecmp(field, h->h_field) == 0)
                        break;
        }

        /* allocate space for new header */
        h = (HDR *) xalloc(sizeof *h);
        h->h_field = field;
        h->h_value = newstr(value);
        h->h_link = *hp;
        h->h_flags = H_DEFAULT;
        if (s != NULL)
                h->h_flags |= s->s_header.hi_flags;
        clrbitmap(h->h_mflags);
        *hp = h;
}
/*
**  HVALUE -- return value of a header.
**
**      Only "real" fields (i.e., ones that have not been supplied
**      as a default) are used.
**
**      Parameters:
**              field -- the field name.
**              header -- the header list.
**
**      Returns:
**              pointer to the value part.
**              NULL if not found.
**
**      Side Effects:
**              none.
*/

char *
hvalue(field, header)
        char *field;
        HDR *header;
{
        register HDR *h;

        for (h = header; h != NULL; h = h->h_link)
        {
                if (!bitset(H_DEFAULT, h->h_flags) &&
                    strcasecmp(h->h_field, field) == 0)
                        return (h->h_value);
        }
        return (NULL);
}
/*
**  ISHEADER -- predicate telling if argument is a header.
**
**      A line is a header if it has a single word followed by
**      optional white space followed by a colon.
**
**      Header fields beginning with two dashes, although technically
**      permitted by RFC822, are automatically rejected in order
**      to make MIME work out.  Without this we could have a technically
**      legal header such as ``--"foo:bar"'' that would also be a legal
**      MIME separator.
**
**      Parameters:
**              h -- string to check for possible headerness.
**
**      Returns:
**              TRUE if h is a header.
**              FALSE otherwise.
**
**      Side Effects:
**              none.
*/

bool
isheader(h)
        char *h;
{
        register char *s = h;

        if (s[0] == '-' && s[1] == '-')
                return FALSE;

        while (*s > ' ' && *s != ':' && *s != '\0')
                s++;

        if (h == s)
                return FALSE;

        /* following technically violates RFC822 */
        while (isascii(*s) && isspace(*s))
                s++;

        return (*s == ':');
}
/*
**  EATHEADER -- run through the stored header and extract info.
**
**      Parameters:
**              e -- the envelope to process.
**              full -- if set, do full processing (e.g., compute
**                      message priority).  This should not be set
**                      when reading a queue file because some info
**                      needed to compute the priority is wrong.
**
**      Returns:
**              none.
**
**      Side Effects:
**              Sets a bunch of global variables from information
**                      in the collected header.
**              Aborts the message if the hop count is exceeded.
*/

void
eatheader(e, full)
        register ENVELOPE *e;
        bool full;
{
        register HDR *h;
        register char *p;
        int hopcnt = 0;
        char *msgid;
        char buf[MAXLINE];
        extern int priencode __P((char *));

        /*
        **  Set up macros for possible expansion in headers.
        */

        define('f', e->e_sender, e);
        define('g', e->e_sender, e);
        if (e->e_origrcpt != NULL && *e->e_origrcpt != '\0')
                define('u', e->e_origrcpt, e);
        else
                define('u', NULL, e);

        /* full name of from person */
        p = hvalue("full-name", e->e_header);
        if (p != NULL)
        {
                extern bool rfc822_string __P((char *));

                if (!rfc822_string(p))
                {
                        extern char *addquotes __P((char *));

                        /*
                        **  Quote a full name with special characters
                        **  as a comment so crackaddr() doesn't destroy
                        **  the name portion of the address.
                        */
                        p = addquotes(p);
                }
                define('x', p, e);
        }

        if (tTd(32, 1))
                printf("----- collected header -----\n");
        msgid = NULL;
        for (h = e->e_header; h != NULL; h = h->h_link)
        {
                if (tTd(32, 1))
                        printf("%s: ", h->h_field);
                if (h->h_value == NULL)
                {
                        if (tTd(32, 1))
                                printf("<NULL>\n");
                        continue;
                }

                /* do early binding */
                if (bitset(H_DEFAULT, h->h_flags))
                {
                        if (tTd(32, 1))
                        {
                                printf("(");
                                xputs(h->h_value);
                                printf(") ");
                        }
                        expand(h->h_value, buf, sizeof buf, e);
                        if (buf[0] != '\0')
                        {
                                if (bitset(H_FROM, h->h_flags))
                                {
                                        extern char *crackaddr __P((char *));

                                        expand(crackaddr(buf), buf, sizeof buf, e);
                                }
                                h->h_value = newstr(buf);
                                h->h_flags &= ~H_DEFAULT;
                        }
                }

                if (tTd(32, 1))
                {
                        xputs(h->h_value);
                        printf("\n");
                }

                /* count the number of times it has been processed */
                if (bitset(H_TRACE, h->h_flags))
                        hopcnt++;

                /* send to this person if we so desire */
                if (GrabTo && bitset(H_RCPT, h->h_flags) &&
                    !bitset(H_DEFAULT, h->h_flags) &&
                    (!bitset(EF_RESENT, e->e_flags) || bitset(H_RESENT, h->h_flags)))
                {
#if 0
                        int saveflags = e->e_flags;
#endif

                        (void) sendtolist(h->h_value, NULLADDR,
                                          &e->e_sendqueue, 0, e);

#if 0
                        /*
                        **  Change functionality so a fatal error on an
                        **  address doesn't affect the entire envelope.
                        */
                         
                        /* delete fatal errors generated by this address */
                        if (!bitset(EF_FATALERRS, saveflags))
                                e->e_flags &= ~EF_FATALERRS;
#endif
                }

                /* save the message-id for logging */
                p = "resent-message-id";
                if (!bitset(EF_RESENT, e->e_flags))
                        p += 7;
                if (strcasecmp(h->h_field, p) == 0)
                {
                        msgid = h->h_value;
                        while (isascii(*msgid) && isspace(*msgid))
                                msgid++;
                }
        }
        if (tTd(32, 1))
                printf("----------------------------\n");

        /* if we are just verifying (that is, sendmail -t -bv), drop out now */
        if (OpMode == MD_VERIFY)
                return;

        /* store hop count */
        if (hopcnt > e->e_hopcount)
                e->e_hopcount = hopcnt;

        /* message priority */
        p = hvalue("precedence", e->e_header);
        if (p != NULL)
                e->e_class = priencode(p);
        if (e->e_class < 0)
                e->e_timeoutclass = TOC_NONURGENT;
        else if (e->e_class > 0)
                e->e_timeoutclass = TOC_URGENT;
        if (full)
        {
                e->e_msgpriority = e->e_msgsize
                                 - e->e_class * WkClassFact
                                 + e->e_nrcpts * WkRecipFact;
        }

        /* message timeout priority */
        p = hvalue("priority", e->e_header);
        if (p != NULL)
        {
                /* (this should be in the configuration file) */
                if (strcasecmp(p, "urgent") == 0)
                        e->e_timeoutclass = TOC_URGENT;
                else if (strcasecmp(p, "normal") == 0)
                        e->e_timeoutclass = TOC_NORMAL;
                else if (strcasecmp(p, "non-urgent") == 0)
                        e->e_timeoutclass = TOC_NONURGENT;
        }

        /* date message originated */
        p = hvalue("posted-date", e->e_header);
        if (p == NULL)
                p = hvalue("date", e->e_header);
        if (p != NULL)
                define('a', p, e);

        /* check to see if this is a MIME message */
        if ((e->e_bodytype != NULL &&
             strcasecmp(e->e_bodytype, "8BITMIME") == 0) ||
            hvalue("MIME-Version", e->e_header) != NULL)
        {
                e->e_flags |= EF_IS_MIME;
                if (HasEightBits)
                        e->e_bodytype = "8BITMIME";
        }
        else if ((p = hvalue("Content-Type", e->e_header)) != NULL)
        {
                /* this may be an RFC 1049 message */
                p = strpbrk(p, ";/");
                if (p == NULL || *p == ';')
                {
                        /* yep, it is */
                        e->e_flags |= EF_DONT_MIME;
                }
        }

        /*
        **  From person in antiquated ARPANET mode
        **      required by UK Grey Book e-mail gateways (sigh)
        */

        if (OpMode == MD_ARPAFTP)
        {
                register struct hdrinfo *hi;

                for (hi = HdrInfo; hi->hi_field != NULL; hi++)
                {
                        if (bitset(H_FROM, hi->hi_flags) &&
                            (!bitset(H_RESENT, hi->hi_flags) ||
                             bitset(EF_RESENT, e->e_flags)) &&
                            (p = hvalue(hi->hi_field, e->e_header)) != NULL)
                                break;
                }
                if (hi->hi_field != NULL)
                {
                        if (tTd(32, 2))
                                printf("eatheader: setsender(*%s == %s)\n",
                                        hi->hi_field, p);
                        setsender(p, e, NULL, '\0', TRUE);
                }
        }

        /*
        **  Log collection information.
        */

        if (bitset(EF_LOGSENDER, e->e_flags) && LogLevel > 4)
                logsender(e, msgid);
        e->e_flags &= ~EF_LOGSENDER;
}
/*
**  LOGSENDER -- log sender information
**
**      Parameters:
**              e -- the envelope to log
**              msgid -- the message id
**
**      Returns:
**              none
*/

void
logsender(e, msgid)
        register ENVELOPE *e;
        char *msgid;
{
        char *name;
        register char *sbp;
        register char *p;
        int l;
        char hbuf[MAXNAME + 1];
        char sbuf[MAXLINE + 1];
        char mbuf[MAXNAME + 1];

        /* don't allow newlines in the message-id */
        if (msgid != NULL)
        {
                l = strlen(msgid);
                if (l > sizeof mbuf - 1)
                        l = sizeof mbuf - 1;
                bcopy(msgid, mbuf, l);
                mbuf[l] = '\0';
                p = mbuf;
                while ((p = strchr(p, '\n')) != NULL)
                        *p++ = ' ';
        }

        if (bitset(EF_RESPONSE, e->e_flags))
                name = "[RESPONSE]";
        else if ((name = macvalue('_', e)) != NULL)
                ;
        else if (RealHostName == NULL)
                name = "localhost";
        else if (RealHostName[0] == '[')
                name = RealHostName;
        else
        {
                name = hbuf;
                (void) snprintf(hbuf, sizeof hbuf, "%.80s", RealHostName);
                if (RealHostAddr.sa.sa_family != 0)
                {
                        p = &hbuf[strlen(hbuf)];
                        (void) snprintf(p, SPACELEFT(hbuf, p), " (%.100s)",
                                anynet_ntoa(&RealHostAddr));
                }
        }

        /* some versions of syslog only take 5 printf args */
#  if (SYSLOG_BUFSIZE) >= 256
        sbp = sbuf;
        snprintf(sbp, SPACELEFT(sbuf, sbp),
            "from=%.200s, size=%ld, class=%d, pri=%ld, nrcpts=%d",
            e->e_from.q_paddr == NULL ? "<NONE>" : e->e_from.q_paddr,
            e->e_msgsize, e->e_class, e->e_msgpriority, e->e_nrcpts);
        sbp += strlen(sbp);
        if (msgid != NULL)
        {
                snprintf(sbp, SPACELEFT(sbuf, sbp), ", msgid=%.100s", mbuf);
                sbp += strlen(sbp);
        }
        if (e->e_bodytype != NULL)
        {
                (void) snprintf(sbp, SPACELEFT(sbuf, sbp), ", bodytype=%.20s",
                        e->e_bodytype);
                sbp += strlen(sbp);
        }
        p = macvalue('r', e);
        if (p != NULL)
                (void) snprintf(sbp, SPACELEFT(sbuf, sbp), ", proto=%.20s", p);
        sm_syslog(LOG_INFO, e->e_id,
                "%.850s, relay=%.100s",
                sbuf, name);

#  else                 /* short syslog buffer */

        sm_syslog(LOG_INFO, e->e_id,
                "from=%s",
                e->e_from.q_paddr == NULL ? "<NONE>"
                                          : shortenstring(e->e_from.q_paddr, 83));
        sm_syslog(LOG_INFO, e->e_id,
                "size=%ld, class=%ld, pri=%ld, nrcpts=%d",
                e->e_msgsize, e->e_class, e->e_msgpriority, e->e_nrcpts);
        if (msgid != NULL)
                sm_syslog(LOG_INFO, e->e_id,
                        "msgid=%s",
                        shortenstring(mbuf, 83));
        sbp = sbuf;
        *sbp = '\0';
        if (e->e_bodytype != NULL)
        {
                snprintf(sbp, SPACELEFT(sbuf, sbp), "bodytype=%.20s, ", e->e_bodytype);
                sbp += strlen(sbp);
        }
        p = macvalue('r', e);
        if (p != NULL)
        {
                snprintf(sbp, SPACELEFT(sbuf, sbp), "proto=%.20s, ", p);
                sbp += strlen(sbp);
        }
        sm_syslog(LOG_INFO, e->e_id,
                "%.400srelay=%.100s", sbuf, name);
#  endif
}
/*
**  PRIENCODE -- encode external priority names into internal values.
**
**      Parameters:
**              p -- priority in ascii.
**
**      Returns:
**              priority as a numeric level.
**
**      Side Effects:
**              none.
*/

int
priencode(p)
        char *p;
{
        register int i;

        for (i = 0; i < NumPriorities; i++)
        {
                if (!strcasecmp(p, Priorities[i].pri_name))
                        return (Priorities[i].pri_val);
        }

        /* unknown priority */
        return (0);
}
/*
**  CRACKADDR -- parse an address and turn it into a macro
**
**      This doesn't actually parse the address -- it just extracts
**      it and replaces it with "$g".  The parse is totally ad hoc
**      and isn't even guaranteed to leave something syntactically
**      identical to what it started with.  However, it does leave
**      something semantically identical.
**
**      This algorithm has been cleaned up to handle a wider range
**      of cases -- notably quoted and backslash escaped strings.
**      This modification makes it substantially better at preserving
**      the original syntax.
**
**      Parameters:
**              addr -- the address to be cracked.
**
**      Returns:
**              a pointer to the new version.
**
**      Side Effects:
**              none.
**
**      Warning:
**              The return value is saved in local storage and should
**              be copied if it is to be reused.
*/

char *
crackaddr(addr)
        register char *addr;
{
        register char *p;
        register char c;
        int cmtlev;
        int realcmtlev;
        int anglelev, realanglelev;
        int copylev;
        int bracklev;
        bool qmode;
        bool realqmode;
        bool skipping;
        bool putgmac = FALSE;
        bool quoteit = FALSE;
        bool gotangle = FALSE;
        bool gotcolon = FALSE;
        register char *bp;
        char *buflim;
        char *bufhead;
        char *addrhead;
        static char buf[MAXNAME + 1];

        if (tTd(33, 1))
                printf("crackaddr(%s)\n", addr);

        /* strip leading spaces */
        while (*addr != '\0' && isascii(*addr) && isspace(*addr))
                addr++;

        /*
        **  Start by assuming we have no angle brackets.  This will be
        **  adjusted later if we find them.
        */

        bp = bufhead = buf;
        buflim = &buf[sizeof buf - 7];
        p = addrhead = addr;
        copylev = anglelev = realanglelev = cmtlev = realcmtlev = 0;
        bracklev = 0;
        qmode = realqmode = FALSE;

        while ((c = *p++) != '\0')
        {
                /*
                **  If the buffer is overful, go into a special "skipping"
                **  mode that tries to keep legal syntax but doesn't actually
                **  output things.
                */

                skipping = bp >= buflim;

                if (copylev > 0 && !skipping)
                        *bp++ = c;

                /* check for backslash escapes */
                if (c == '\\')
                {
                        /* arrange to quote the address */
                        if (cmtlev <= 0 && !qmode)
                                quoteit = TRUE;

                        if ((c = *p++) == '\0')
                        {
                                /* too far */
                                p--;
                                goto putg;
                        }
                        if (copylev > 0 && !skipping)
                                *bp++ = c;
                        goto putg;
                }

                /* check for quoted strings */
                if (c == '"' && cmtlev <= 0)
                {
                        qmode = !qmode;
                        if (copylev > 0 && !skipping)
                                realqmode = !realqmode;
                        continue;
                }
                if (qmode)
                        goto putg;

                /* check for comments */
                if (c == '(')
                {
                        cmtlev++;

                        /* allow space for closing paren */
                        if (!skipping)
                        {
                                buflim--;
                                realcmtlev++;
                                if (copylev++ <= 0)
                                {
                                        if (bp != bufhead)
                                                *bp++ = ' ';
                                        *bp++ = c;
                                }
                        }
                }
                if (cmtlev > 0)
                {
                        if (c == ')')
                        {
                                cmtlev--;
                                copylev--;
                                if (!skipping)
                                {
                                        realcmtlev--;
                                        buflim++;
                                }
                        }
                        continue;
                }
                else if (c == ')')
                {
                        /* syntax error: unmatched ) */
                        if (copylev > 0 && !skipping)
                                bp--;
                }

                /* count nesting on [ ... ] (for IPv6 domain literals) */
                if (c == '[')
                        bracklev++;
                else if (c == ']')
                        bracklev--;

                /* check for group: list; syntax */
                if (c == ':' && anglelev <= 0 && bracklev <= 0 &&
                    !gotcolon && !ColonOkInAddr)
                {
                        register char *q;

                        /*
                        **  Check for DECnet phase IV ``::'' (host::user)
                        **  or **  DECnet phase V ``:.'' syntaxes.  The latter
                        **  covers ``user@DEC:.tay.myhost'' and
                        **  ``DEC:.tay.myhost::user'' syntaxes (bletch).
                        */

                        if (*p == ':' || *p == '.')
                        {
                                if (cmtlev <= 0 && !qmode)
                                        quoteit = TRUE;
                                if (copylev > 0 && !skipping)
                                {
                                        *bp++ = c;
                                        *bp++ = *p;
                                }
                                p++;
                                goto putg;
                        }

                        gotcolon = TRUE;

                        bp = bufhead;
                        if (quoteit)
                        {
                                *bp++ = '"';

                                /* back up over the ':' and any spaces */
                                --p;
                                while (isascii(*--p) && isspace(*p))
                                        continue;
                                p++;
                        }
                        for (q = addrhead; q < p; )
                        {
                                c = *q++;
                                if (bp < buflim)
                                {
                                        if (quoteit && c == '"')
                                                *bp++ = '\\';
                                        *bp++ = c;
                                }
                        }
                        if (quoteit)
                        {
                                if (bp == &bufhead[1])
                                        bp--;
                                else
                                        *bp++ = '"';
                                while ((c = *p++) != ':')
                                {
                                        if (bp < buflim)
                                                *bp++ = c;
                                }
                                *bp++ = c;
                        }

                        /* any trailing white space is part of group: */
                        while (isascii(*p) && isspace(*p) && bp < buflim)
                                *bp++ = *p++;
                        copylev = 0;
                        putgmac = quoteit = FALSE;
                        bufhead = bp;
                        addrhead = p;
                        continue;
                }

                if (c == ';' && copylev <= 0 && !ColonOkInAddr)
                {
                        if (bp < buflim)
                                *bp++ = c;
                }

                /* check for characters that may have to be quoted */
                if (strchr(MustQuoteChars, c) != NULL)
                {
                        /*
                        **  If these occur as the phrase part of a <>
                        **  construct, but are not inside of () or already
                        **  quoted, they will have to be quoted.  Note that
                        **  now (but don't actually do the quoting).
                        */

                        if (cmtlev <= 0 && !qmode)
                                quoteit = TRUE;
                }

                /* check for angle brackets */
                if (c == '<')
                {
                        register char *q;

                        /* assume first of two angles is bogus */
                        if (gotangle)
                                quoteit = TRUE;
                        gotangle = TRUE;

                        /* oops -- have to change our mind */
                        anglelev = 1;
                        if (!skipping)
                                realanglelev = 1;

                        bp = bufhead;
                        if (quoteit)
                        {
                                *bp++ = '"';

                                /* back up over the '<' and any spaces */
                                --p;
                                while (isascii(*--p) && isspace(*p))
                                        continue;
                                p++;
                        }
                        for (q = addrhead; q < p; )
                        {
                                c = *q++;
                                if (bp < buflim)
                                {
                                        if (quoteit && c == '"')
                                                *bp++ = '\\';
                                        *bp++ = c;
                                }
                        }
                        if (quoteit)
                        {
                                if (bp == &buf[1])
                                        bp--;
                                else
                                        *bp++ = '"';
                                while ((c = *p++) != '<')
                                {
                                        if (bp < buflim)
                                                *bp++ = c;
                                }
                                *bp++ = c;
                        }
                        copylev = 0;
                        putgmac = quoteit = FALSE;
                        continue;
                }

                if (c == '>')
                {
                        if (anglelev > 0)
                        {
                                anglelev--;
                                if (!skipping)
                                {
                                        realanglelev--;
                                        buflim++;
                                }
                        }
                        else if (!skipping)
                        {
                                /* syntax error: unmatched > */
                                if (copylev > 0)
                                        bp--;
                                quoteit = TRUE;
                                continue;
                        }
                        if (copylev++ <= 0)
                                *bp++ = c;
                        continue;
                }

                /* must be a real address character */
        putg:
                if (copylev <= 0 && !putgmac)
                {
                        if (bp > bufhead && bp[-1] == ')')
                                *bp++ = ' ';
                        *bp++ = MACROEXPAND;
                        *bp++ = 'g';
                        putgmac = TRUE;
                }
        }

        /* repair any syntactic damage */
        if (realqmode)
                *bp++ = '"';
        while (realcmtlev-- > 0)
                *bp++ = ')';
        while (realanglelev-- > 0)
                *bp++ = '>';
        *bp++ = '\0';

        if (tTd(33, 1))
        {
                printf("crackaddr=>`");
                xputs(buf);
                printf("'\n");
        }

        return (buf);
}
/*
**  PUTHEADER -- put the header part of a message from the in-core copy
**
**      Parameters:
**              mci -- the connection information.
**              h -- the header to put.
**              e -- envelope to use.
**              flags -- MIME conversion flags.
**
**      Returns:
**              none.
**
**      Side Effects:
**              none.
*/

/*
 * Macro for fast max (not available in e.g. DG/UX, 386/ix).
 */
#ifndef MAX
# define MAX(a,b) (((a)>(b))?(a):(b))
#endif

void
putheader(mci, hdr, e, flags)
        register MCI *mci;
        HDR *hdr;
        register ENVELOPE *e;
        int flags;
{
        register HDR *h;
        char buf[MAX(MAXLINE,BUFSIZ)];
        char obuf[MAXLINE];

        if (tTd(34, 1))
                printf("--- putheader, mailer = %s ---\n",
                        mci->mci_mailer->m_name);

        /*
        **  If we're in MIME mode, we're not really in the header of the
        **  message, just the header of one of the parts of the body of
        **  the message.  Therefore MCIF_INHEADER should not be turned on.
        */

        if (!bitset(MCIF_INMIME, mci->mci_flags))
                mci->mci_flags |= MCIF_INHEADER;

        for (h = hdr; h != NULL; h = h->h_link)
        {
                register char *p = h->h_value;
                extern bool bitintersect __P((BITMAP, BITMAP));

                if (tTd(34, 11))
                {
                        printf("  %s: ", h->h_field);
                        xputs(p);
                }

#if _FFR_MAX_MIME_HEADER_LENGTH
                /* heuristic shortening of MIME fields to avoid MUA overflows */
                if (MaxMimeFieldLength > 0 &&
                    wordinclass(h->h_field,
                                macid("{checkMIMEFieldHeaders}", NULL)))
                {
                        extern bool fix_mime_header __P((char *));

                        if (fix_mime_header(h->h_value))
                        {
                                sm_syslog(LOG_ALERT, e->e_id,
                                        "Truncated MIME %s header due to field size (possible attack)",
                                        h->h_field);
                                if (tTd(34, 11))
                                        printf("  truncated MIME %s header due to field size (possible attack)\n",
                                                h->h_field);
                        }
                }

                if (MaxMimeHeaderLength > 0 &&
                    wordinclass(h->h_field,
                                macid("{checkMIMETextHeaders}", NULL)))
                {
                        if (strlen(h->h_value) > MaxMimeHeaderLength)
                        {
                                h->h_value[MaxMimeHeaderLength - 1] = '\0';
                                sm_syslog(LOG_ALERT, e->e_id,
                                        "Truncated long MIME %s header (possible attack)",
                                        h->h_field);
                                if (tTd(34, 11))
                                        printf("  truncated long MIME %s header (possible attack)\n",
                                                h->h_field);
                        }
                }

                if (MaxMimeHeaderLength > 0 &&
                    wordinclass(h->h_field,
                                macid("{checkMIMEHeaders}", NULL)))
                {
                        extern bool shorten_rfc822_string __P((char *, int));

                        if (shorten_rfc822_string(h->h_value, MaxMimeHeaderLength))
                        {
                                sm_syslog(LOG_ALERT, e->e_id,
                                        "Truncated long MIME %s header (possible attack)",
                                        h->h_field);
                                if (tTd(34, 11))
                                        printf("  truncated long MIME %s header (possible attack)\n",
                                                h->h_field);
                        }
                }
#endif

                /*
                **  Suppress Content-Transfer-Encoding: if we are MIMEing
                **  and we are potentially converting from 8 bit to 7 bit
                **  MIME.  If converting, add a new CTE header in
                **  mime8to7().
                */
                if (bitset(H_CTE, h->h_flags) &&
                    bitset(MCIF_CVT8TO7|MCIF_CVT7TO8|MCIF_INMIME,
                           mci->mci_flags) &&
                    !bitset(M87F_NO8TO7, flags))
                {
                        if (tTd(34, 11))
                                printf(" (skipped (content-transfer-encoding))\n");
                        continue;
                }

                if (bitset(MCIF_INMIME, mci->mci_flags))
                {
                        if (tTd(34, 11))
                                printf("\n");
                        put_vanilla_header(h, p, mci);
                        continue;
                }

                if (bitset(H_CHECK|H_ACHECK, h->h_flags) &&
                    !bitintersect(h->h_mflags, mci->mci_mailer->m_flags))
                {
                        if (tTd(34, 11))
                                printf(" (skipped)\n");
                        continue;
                }

                /* handle Resent-... headers specially */
                if (bitset(H_RESENT, h->h_flags) && !bitset(EF_RESENT, e->e_flags))
                {
                        if (tTd(34, 11))
                                printf(" (skipped (resent))\n");
                        continue;
                }

                /* suppress return receipts if requested */
                if (bitset(H_RECEIPTTO, h->h_flags) &&
#if _FFR_DSN_RRT_OPTION
                    (RrtImpliesDsn || bitset(EF_NORECEIPT, e->e_flags)))
#else
                    bitset(EF_NORECEIPT, e->e_flags))
#endif
                {
                        if (tTd(34, 11))
                                printf(" (skipped (receipt))\n");
                        continue;
                }

                /* macro expand value if generated internally */
                if (bitset(H_DEFAULT, h->h_flags))
                {
                        expand(p, buf, sizeof buf, e);
                        p = buf;
                        if (*p == '\0')
                        {
                                if (tTd(34, 11))
                                        printf(" (skipped -- null value)\n");
                                continue;
                        }
                }

                if (bitset(H_BCC, h->h_flags))
                {
                        /* Bcc: field -- either truncate or delete */
                        if (bitset(EF_DELETE_BCC, e->e_flags))
                        {
                                if (tTd(34, 11))
                                        printf(" (skipped -- bcc)\n");
                        }
                        else
                        {
                                /* no other recipient headers: truncate value */
                                (void) snprintf(obuf, sizeof obuf, "%s:",
                                        h->h_field);
                                putline(obuf, mci);
                        }
                        continue;
                }

                if (tTd(34, 11))
                        printf("\n");

                if (bitset(H_FROM|H_RCPT, h->h_flags))
                {
                        /* address field */
                        bool oldstyle = bitset(EF_OLDSTYLE, e->e_flags);

                        if (bitset(H_FROM, h->h_flags))
                                oldstyle = FALSE;
                        commaize(h, p, oldstyle, mci, e);
                }
                else
                {
                        put_vanilla_header(h, p, mci);
                }
        }

        /*
        **  If we are converting this to a MIME message, add the
        **  MIME headers.
        */

#if MIME8TO7
        if (bitset(MM_MIME8BIT, MimeMode) &&
            bitset(EF_HAS8BIT, e->e_flags) &&
            !bitset(EF_DONT_MIME, e->e_flags) &&
            !bitnset(M_8BITS, mci->mci_mailer->m_flags) &&
            !bitset(MCIF_CVT8TO7|MCIF_CVT7TO8, mci->mci_flags))
        {
                if (hvalue("MIME-Version", e->e_header) == NULL)
                        putline("MIME-Version: 1.0", mci);
                if (hvalue("Content-Type", e->e_header) == NULL)
                {
                        snprintf(obuf, sizeof obuf,
                                "Content-Type: text/plain; charset=%s",
                                defcharset(e));
                        putline(obuf, mci);
                }
                if (hvalue("Content-Transfer-Encoding", e->e_header) == NULL)
                        putline("Content-Transfer-Encoding: 8bit", mci);
        }
#endif
}
/*
**  PUT_VANILLA_HEADER -- output a fairly ordinary header
**
**      Parameters:
**              h -- the structure describing this header
**              v -- the value of this header
**              mci -- the connection info for output
**
**      Returns:
**              none.
*/

void
put_vanilla_header(h, v, mci)
        HDR *h;
        char *v;
        MCI *mci;
{
        register char *nlp;
        register char *obp;
        int putflags;
        char obuf[MAXLINE];

        putflags = PXLF_HEADER;
#if _FFR_7BITHDRS
        if (bitnset(M_7BITHDRS, mci->mci_mailer->m_flags))
                putflags |= PXLF_STRIP8BIT;
#endif
        (void) snprintf(obuf, sizeof obuf, "%.200s: ", h->h_field);
        obp = obuf + strlen(obuf);
        while ((nlp = strchr(v, '\n')) != NULL)
        {
                int l;

                l = nlp - v;
                if (SPACELEFT(obuf, obp) - 1 < l)
                        l = SPACELEFT(obuf, obp) - 1;

                snprintf(obp, SPACELEFT(obuf, obp), "%.*s", l, v);
                putxline(obuf, strlen(obuf), mci, putflags);
                v += l + 1;
                obp = obuf;
                if (*v != ' ' && *v != '\t')
                        *obp++ = ' ';
        }
        snprintf(obp, SPACELEFT(obuf, obp), "%.*s",
                sizeof obuf - (obp - obuf) - 1, v);
        putxline(obuf, strlen(obuf), mci, putflags);
}
/*
**  COMMAIZE -- output a header field, making a comma-translated list.
**
**      Parameters:
**              h -- the header field to output.
**              p -- the value to put in it.
**              oldstyle -- TRUE if this is an old style header.
**              mci -- the connection information.
**              e -- the envelope containing the message.
**
**      Returns:
**              none.
**
**      Side Effects:
**              outputs "p" to file "fp".
*/

void
commaize(h, p, oldstyle, mci, e)
        register HDR *h;
        register char *p;
        bool oldstyle;
        register MCI *mci;
        register ENVELOPE *e;
{
        register char *obp;
        int opos;
        int omax;
        bool firstone = TRUE;
        int putflags = PXLF_HEADER;
        char obuf[MAXLINE + 3];

        /*
        **  Output the address list translated by the
        **  mailer and with commas.
        */

        if (tTd(14, 2))
                printf("commaize(%s: %s)\n", h->h_field, p);

#if _FFR_7BITHDRS
        if (bitnset(M_7BITHDRS, mci->mci_mailer->m_flags))
                putflags |= PXLF_STRIP8BIT;
#endif

        obp = obuf;
        (void) snprintf(obp, SPACELEFT(obuf, obp), "%.200s: ", h->h_field);
        opos = strlen(h->h_field) + 2;
        if (opos > 202)
                opos = 202;
        obp += opos;
        omax = mci->mci_mailer->m_linelimit - 2;
        if (omax < 0 || omax > 78)
                omax = 78;

        /*
        **  Run through the list of values.
        */

        while (*p != '\0')
        {
                register char *name;
                register int c;
                char savechar;
                int flags;
                auto int stat;

                /*
                **  Find the end of the name.  New style names
                **  end with a comma, old style names end with
                **  a space character.  However, spaces do not
                **  necessarily delimit an old-style name -- at
                **  signs mean keep going.
                */

                /* find end of name */
                while ((isascii(*p) && isspace(*p)) || *p == ',')
                        p++;
                name = p;
                for (;;)
                {
                        auto char *oldp;
                        char pvpbuf[PSBUFSIZE];

                        (void) prescan(p, oldstyle ? ' ' : ',', pvpbuf,
                                       sizeof pvpbuf, &oldp, NULL);
                        p = oldp;

                        /* look to see if we have an at sign */
                        while (*p != '\0' && isascii(*p) && isspace(*p))
                                p++;

                        if (*p != '@')
                        {
                                p = oldp;
                                break;
                        }
                        p += *p == '@' ? 1 : 2;
                        while (*p != '\0' && isascii(*p) && isspace(*p))
                                p++;
                }
                /* at the end of one complete name */

                /* strip off trailing white space */
                while (p >= name &&
                       ((isascii(*p) && isspace(*p)) || *p == ',' || *p == '\0'))
                        p--;
                if (++p == name)
                        continue;
                savechar = *p;
                *p = '\0';

                /* translate the name to be relative */
                flags = RF_HEADERADDR|RF_ADDDOMAIN;
                if (bitset(H_FROM, h->h_flags))
                        flags |= RF_SENDERADDR;
#if USERDB
                else if (e->e_from.q_mailer != NULL &&
                         bitnset(M_UDBRECIPIENT, e->e_from.q_mailer->m_flags))
                {
                        extern char *udbsender __P((char *));
                        char *q;

                        q = udbsender(name);
                        if (q != NULL)
                                name = q;
                }
#endif
                stat = EX_OK;
                name = remotename(name, mci->mci_mailer, flags, &stat, e);
                if (*name == '\0')
                {
                        *p = savechar;
                        continue;
                }
                name = denlstring(name, FALSE, TRUE);

                /* output the name with nice formatting */
                opos += strlen(name);
                if (!firstone)
                        opos += 2;
                if (opos > omax && !firstone)
                {
                        snprintf(obp, SPACELEFT(obuf, obp), ",\n");
                        putxline(obuf, strlen(obuf), mci, putflags);
                        obp = obuf;
                        (void) strcpy(obp, "        ");
                        opos = strlen(obp);
                        obp += opos;
                        opos += strlen(name);
                }
                else if (!firstone)
                {
                        snprintf(obp, SPACELEFT(obuf, obp), ", ");
                        obp += 2;
                }

                while ((c = *name++) != '\0' && obp < &obuf[MAXLINE])
                        *obp++ = c;
                firstone = FALSE;
                *p = savechar;
        }
        *obp = '\0';
        putxline(obuf, strlen(obuf), mci, putflags);
}
/*
**  COPYHEADER -- copy header list
**
**      This routine is the equivalent of newstr for header lists
**
**      Parameters:
**              header -- list of header structures to copy.
**
**      Returns:
**              a copy of 'header'.
**
**      Side Effects:
**              none.
*/

HDR *
copyheader(header)
        register HDR *header;
{
        register HDR *newhdr;
        HDR *ret;
        register HDR **tail = &ret;

        while (header != NULL)
        {
                newhdr = (HDR *) xalloc(sizeof(HDR));
                STRUCTCOPY(*header, *newhdr);
                *tail = newhdr;
                tail = &newhdr->h_link;
                header = header->h_link;
        }
        *tail = NULL;
        
        return ret;
}
/*
**  FIX_MIME_HEADER -- possibly truncate/rebalance parameters in a MIME header
**
**      Run through all of the parameters of a MIME header and
**      possibly truncate and rebalance the parameter according
**      to MaxMimeFieldLength.
**
**      Parameters:
**              string -- the full header
**
**      Returns:
**              TRUE if the header was modified, FALSE otherwise
**
**      Side Effects:
**              string modified in place
*/

bool
fix_mime_header(string)
        char *string;
{
        bool modified = FALSE;
        char *begin = string;
        char *end;
        extern char *find_character __P((char *, char));
        extern bool shorten_rfc822_string __P((char *, int));
        
        if (string == NULL || *string == '\0')
                return FALSE;
        
        /* Split on each ';' */
        while ((end = find_character(begin, ';')) != NULL)
        {
                char save = *end;
                char *bp;
                
                *end = '\0';
                
                /* Shorten individual parameter */
                if (shorten_rfc822_string(begin, MaxMimeFieldLength))
                        modified = TRUE;
                
                /* Collapse the possibly shortened string with rest */
                bp = begin + strlen(begin);
                if (bp != end)
                {
                        char *ep = end;
                        
                        *end = save;
                        end = bp;
                        
                        /* copy character by character due to overlap */
                        while (*ep != '\0')
                                *bp++ = *ep++;
                        *bp = '\0';
                }
                else
                        *end = save;
                if (*end == '\0')
                        break;
                
                /* Move past ';' */
                begin = end + 1;
        }
        return modified;
}