usr.sbin/sendmail/src/envelope.c

/*
 * Copyright (c) 1983 Eric P. Allman
 * Copyright (c) 1988 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
static char sccsid[] = "@(#)envelope.c  5.22 (Berkeley) 6/1/90";
#endif /* not lint */

#include <sys/types.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <pwd.h>
#include <sys/file.h>
#include "sendmail.h"

/*
**  NEWENVELOPE -- allocate a new envelope
**
**      Supports inheritance.
**
**      Parameters:
**              e -- the new envelope to fill in.
**
**      Returns:
**              e.
**
**      Side Effects:
**              none.
*/

ENVELOPE *
newenvelope(e)
        register ENVELOPE *e;
{
        register ENVELOPE *parent;
        extern putheader(), putbody();
        extern ENVELOPE BlankEnvelope;

        parent = CurEnv;
        if (e == CurEnv)
                parent = e->e_parent;
        clearenvelope(e, TRUE);
        if (e == CurEnv)
                bcopy((char *) &NullAddress, (char *) &e->e_from, sizeof e->e_from);
        else
                bcopy((char *) &CurEnv->e_from, (char *) &e->e_from, sizeof e->e_from);
        e->e_parent = parent;
        e->e_ctime = curtime();
        e->e_msgpriority = parent->e_msgsize;
        e->e_puthdr = putheader;
        e->e_putbody = putbody;
        if (CurEnv->e_xfp != NULL)
                (void) fflush(CurEnv->e_xfp);

        return (e);
}
\f/*
**  DROPENVELOPE -- deallocate an envelope.
**
**      Parameters:
**              e -- the envelope to deallocate.
**
**      Returns:
**              none.
**
**      Side Effects:
**              housekeeping necessary to dispose of an envelope.
**              Unlocks this queue file.
*/

dropenvelope(e)
        register ENVELOPE *e;
{
        bool queueit = FALSE;
        register ADDRESS *q;

        if (tTd(50, 1))
        {
                printf("dropenvelope %x id=", e);
                xputs(e->e_id);
                printf(" flags=%o\n", e->e_flags);
        }
#ifdef LOG
        if (LogLevel > 10)
                syslog(LOG_DEBUG, "dropenvelope, id=%s, flags=%o, pid=%d",
                                  e->e_id == NULL ? "(none)" : e->e_id,
                                  e->e_flags, getpid());
#endif LOG

        /* we must have an id to remove disk files */
        if (e->e_id == NULL)
                return;

        /*
        **  Extract state information from dregs of send list.
        */

        for (q = e->e_sendqueue; q != NULL; q = q->q_next)
        {
                if (bitset(QQUEUEUP, q->q_flags))
                        queueit = TRUE;
        }

        /*
        **  Send back return receipts as requested.
        */

        if (e->e_receiptto != NULL && bitset(EF_SENDRECEIPT, e->e_flags))
        {
                auto ADDRESS *rlist = NULL;

                sendtolist(CurEnv->e_receiptto, (ADDRESS *) NULL, &rlist);
                (void) returntosender("Return receipt", rlist, FALSE);
        }

        /*
        **  Arrange to send error messages if there are fatal errors.
        */

        if (bitset(EF_FATALERRS|EF_TIMEOUT, e->e_flags) && ErrorMode != EM_QUIET)
                savemail(e);

        /*
        **  Instantiate or deinstantiate the queue.
        */

        if ((!queueit && !bitset(EF_KEEPQUEUE, e->e_flags)) ||
            bitset(EF_CLRQUEUE, e->e_flags))
        {
                if (e->e_df != NULL)
                        xunlink(e->e_df);
                xunlink(queuename(e, 'q'));
        }
        else if (queueit || !bitset(EF_INQUEUE, e->e_flags))
        {
#ifdef QUEUE
                FILE *lockfp, *queueup();
                lockfp = queueup(e, FALSE, FALSE);
                if (lockfp != NULL)
                        (void) fclose(lockfp);
#else QUEUE
                syserr("dropenvelope: queueup");
#endif QUEUE
        }

        /* now unlock the job */
        closexscript(e);
        unlockqueue(e);

        /* make sure that this envelope is marked unused */
        e->e_id = e->e_df = NULL;
        if (e->e_dfp != NULL)
                (void) fclose(e->e_dfp);
        e->e_dfp = NULL;
}
\f/*
**  CLEARENVELOPE -- clear an envelope without unlocking
**
**      This is normally used by a child process to get a clean
**      envelope without disturbing the parent.
**
**      Parameters:
**              e -- the envelope to clear.
**              fullclear - if set, the current envelope is total
**                      garbage and should be ignored; otherwise,
**                      release any resources it may indicate.
**
**      Returns:
**              none.
**
**      Side Effects:
**              Closes files associated with the envelope.
**              Marks the envelope as unallocated.
*/

clearenvelope(e, fullclear)
        register ENVELOPE *e;
        bool fullclear;
{
        register HDR *bh;
        register HDR **nhp;
        extern ENVELOPE BlankEnvelope;

        if (!fullclear)
        {
                /* clear out any file information */
                if (e->e_xfp != NULL)
                        (void) fclose(e->e_xfp);
                if (e->e_dfp != NULL)
                        (void) fclose(e->e_dfp);
        }

        /* now clear out the data */
        STRUCTCOPY(BlankEnvelope, *e);
        bh = BlankEnvelope.e_header;
        nhp = &e->e_header;
        while (bh != NULL)
        {
                *nhp = (HDR *) xalloc(sizeof *bh);
                bcopy((char *) bh, (char *) *nhp, sizeof *bh);
                bh = bh->h_link;
                nhp = &(*nhp)->h_link;
        }
}
\f/*
**  INITSYS -- initialize instantiation of system
**
**      In Daemon mode, this is done in the child.
**
**      Parameters:
**              none.
**
**      Returns:
**              none.
**
**      Side Effects:
**              Initializes the system macros, some global variables,
**              etc.  In particular, the current time in various
**              forms is set.
*/

initsys()
{
        static char cbuf[5];                    /* holds hop count */
        static char pbuf[10];                   /* holds pid */
#ifdef TTYNAME
        static char ybuf[10];                   /* holds tty id */
        register char *p;
#endif TTYNAME
        extern char *ttyname();
        extern char *macvalue();
        extern char Version[];

        /*
        **  Give this envelope a reality.
        **      I.e., an id, a transcript, and a creation time.
        */

        openxscript(CurEnv);
        CurEnv->e_ctime = curtime();

        /*
        **  Set OutChannel to something useful if stdout isn't it.
        **      This arranges that any extra stuff the mailer produces
        **      gets sent back to the user on error (because it is
        **      tucked away in the transcript).
        */

        if (OpMode == MD_DAEMON && QueueRun)
                OutChannel = CurEnv->e_xfp;

        /*
        **  Set up some basic system macros.
        */

        /* process id */
        (void) sprintf(pbuf, "%d", getpid());
        define('p', pbuf, CurEnv);

        /* hop count */
        (void) sprintf(cbuf, "%d", CurEnv->e_hopcount);
        define('c', cbuf, CurEnv);

        /* time as integer, unix time, arpa time */
        settime();

#ifdef TTYNAME
        /* tty name */
        if (macvalue('y', CurEnv) == NULL)
        {
                p = ttyname(2);
                if (p != NULL)
                {
                        if (rindex(p, '/') != NULL)
                                p = rindex(p, '/') + 1;
                        (void) strcpy(ybuf, p);
                        define('y', ybuf, CurEnv);
                }
        }
#endif TTYNAME
}
\f/*
**  SETTIME -- set the current time.
**
**      Parameters:
**              none.
**
**      Returns:
**              none.
**
**      Side Effects:
**              Sets the various time macros -- $a, $b, $d, $t.
*/

settime()
{
        register char *p;
        auto time_t now;
        static char tbuf[20];                   /* holds "current" time */
        static char dbuf[30];                   /* holds ctime(tbuf) */
        register struct tm *tm;
        extern char *arpadate();
        extern struct tm *gmtime();
        extern char *macvalue();

        now = curtime();
        tm = gmtime(&now);
        (void) sprintf(tbuf, "%02d%02d%02d%02d%02d", tm->tm_year, tm->tm_mon+1,
                        tm->tm_mday, tm->tm_hour, tm->tm_min);
        define('t', tbuf, CurEnv);
        (void) strcpy(dbuf, ctime(&now));
        *index(dbuf, '\n') = '\0';
        if (macvalue('d', CurEnv) == NULL)
                define('d', dbuf, CurEnv);
        p = newstr(arpadate(dbuf));
        if (macvalue('a', CurEnv) == NULL)
                define('a', p, CurEnv);
        define('b', p, CurEnv);
}
\f/*
**  OPENXSCRIPT -- Open transcript file
**
**      Creates a transcript file for possible eventual mailing or
**      sending back.
**
**      Parameters:
**              e -- the envelope to create the transcript in/for.
**
**      Returns:
**              none
**
**      Side Effects:
**              Creates the transcript file.
*/

openxscript(e)
        register ENVELOPE *e;
{
        register char *p;
        int fd;

# ifdef LOG
        if (LogLevel > 19)
                syslog(LOG_DEBUG, "%s: openx%s", e->e_id, e->e_xfp == NULL ? "" : " (no)");
# endif LOG
        if (e->e_xfp != NULL)
                return;
        p = queuename(e, 'x');
        fd = open(p, O_WRONLY|O_CREAT, 0644);
        if (fd < 0)
                syserr("Can't create %s", p);
        else
                e->e_xfp = fdopen(fd, "w");
}
\f/*
**  CLOSEXSCRIPT -- close the transcript file.
**
**      Parameters:
**              e -- the envelope containing the transcript to close.
**
**      Returns:
**              none.
**
**      Side Effects:
**              none.
*/

closexscript(e)
        register ENVELOPE *e;
{
        if (e->e_xfp == NULL)
                return;
        (void) fclose(e->e_xfp);
        e->e_xfp = NULL;
}
\f/*
**  SETSENDER -- set the person who this message is from
**
**      Under certain circumstances allow the user to say who
**      s/he is (using -f or -r).  These are:
**      1.  The user's uid is zero (root).
**      2.  The user's login name is in an approved list (typically
**          from a network server).
**      3.  The address the user is trying to claim has a
**          "!" character in it (since #2 doesn't do it for
**          us if we are dialing out for UUCP).
**      A better check to replace #3 would be if the
**      effective uid is "UUCP" -- this would require me
**      to rewrite getpwent to "grab" uucp as it went by,
**      make getname more nasty, do another passwd file
**      scan, or compile the UID of "UUCP" into the code,
**      all of which are reprehensible.
**
**      Assuming all of these fail, we figure out something
**      ourselves.
**
**      Parameters:
**              from -- the person we would like to believe this message
**                      is from, as specified on the command line.
**
**      Returns:
**              none.
**
**      Side Effects:
**              sets sendmail's notion of who the from person is.
*/

setsender(from)
        char *from;
{
        register char **pvp;
        char *realname = NULL;
        register struct passwd *pw;
        char buf[MAXNAME];
        char pvpbuf[PSBUFSIZE];
        extern struct passwd *getpwnam();
        extern char *macvalue();
        extern char **prescan();
        extern bool safefile();
        extern char *FullName;

        if (tTd(45, 1))
                printf("setsender(%s)\n", from == NULL ? "" : from);

        /*
        **  Figure out the real user executing us.
        **      Username can return errno != 0 on non-errors.
        */

        if (QueueRun || OpMode == MD_SMTP || OpMode == MD_ARPAFTP)
                realname = from;
        if (realname == NULL || realname[0] == '\0')
        {
                extern char *username();

                realname = username();
        }

        /*
        **  Determine if this real person is allowed to alias themselves.
        */

        if (from != NULL)
        {
                extern bool trusteduser();

                if (!trusteduser(realname) && getuid() != geteuid() &&
                    index(from, '!') == NULL && getuid() != 0)
                {
                        /* network sends -r regardless (why why why?) */
                        /* syserr("%s, you cannot use the -f flag", realname); */
                        from = NULL;
                }
        }

        SuprErrs = TRUE;
        if (from == NULL || parseaddr(from, &CurEnv->e_from, 1, '\0') == NULL)
        {
                /* log garbage addresses for traceback */
                if (from != NULL)
                {
# ifdef LOG
                        if (LogLevel >= 1)
                            if (realname == from && RealHostName != NULL)
                                syslog(LOG_NOTICE,
                                    "from=%s unparseable, received from %s",
                                    from, RealHostName);
                            else
                                syslog(LOG_NOTICE,
                                    "Unparseable username %s wants from=%s",
                                    realname, from);
# endif LOG
                }
                from = newstr(realname);
                if (parseaddr(from, &CurEnv->e_from, 1, '\0') == NULL &&
                    parseaddr("postmaster", &CurEnv->e_from, 1, '\0') == NULL)
                {
                        syserr("setsender: can't even parse postmaster!");
                }
        }
        else
                FromFlag = TRUE;
        CurEnv->e_from.q_flags |= QDONTSEND;
        loweraddr(&CurEnv->e_from);
        SuprErrs = FALSE;

        if (CurEnv->e_from.q_mailer == LocalMailer &&
            (pw = getpwnam(CurEnv->e_from.q_user)) != NULL)
        {
                /*
                **  Process passwd file entry.
                */


                /* extract home directory */
                CurEnv->e_from.q_home = newstr(pw->pw_dir);
                define('z', CurEnv->e_from.q_home, CurEnv);

                /* extract user and group id */
                CurEnv->e_from.q_uid = pw->pw_uid;
                CurEnv->e_from.q_gid = pw->pw_gid;

                /* if the user has given fullname already, don't redefine */
                if (FullName == NULL)
                        FullName = macvalue('x', CurEnv);
                if (FullName != NULL && FullName[0] == '\0')
                        FullName = NULL;

                /* extract full name from passwd file */
                if (FullName == NULL && pw->pw_gecos != NULL &&
                    strcmp(pw->pw_name, CurEnv->e_from.q_user) == 0)
                {
                        buildfname(pw->pw_gecos, CurEnv->e_from.q_user, buf);
                        if (buf[0] != '\0')
                                FullName = newstr(buf);
                }
                if (FullName != NULL)
                        define('x', FullName, CurEnv);
        }
        else
        {
                if (CurEnv->e_from.q_home == NULL)
                        CurEnv->e_from.q_home = getenv("HOME");
                CurEnv->e_from.q_uid = getuid();
                CurEnv->e_from.q_gid = getgid();
        }

        /*
        **  Rewrite the from person to dispose of possible implicit
        **      links in the net.
        */

        pvp = prescan(from, '\0', pvpbuf);
        if (pvp == NULL)
        {
# ifdef LOG
                if (LogLevel >= 1)
                        syslog(LOG_NOTICE, "cannot prescan from (%s)", from);
# endif
                usrerr("cannot prescan from (%s)", from);
                finis();
        }
        rewrite(pvp, 3);
        rewrite(pvp, 1);
        rewrite(pvp, 4);
        cataddr(pvp, buf, sizeof buf);
        define('f', newstr(buf), CurEnv);

        /* save the domain spec if this mailer wants it */
        if (CurEnv->e_from.q_mailer != NULL &&
            bitnset(M_CANONICAL, CurEnv->e_from.q_mailer->m_flags))
        {
                extern char **copyplist();

                while (*pvp != NULL && strcmp(*pvp, "@") != 0)
                        pvp++;
                if (*pvp != NULL)
                        CurEnv->e_fromdomain = copyplist(pvp, TRUE);
        }
}
\f/*
**  TRUSTEDUSER -- tell us if this user is to be trusted.
**
**      Parameters:
**              user -- the user to be checked.
**
**      Returns:
**              TRUE if the user is in an approved list.
**              FALSE otherwise.
**
**      Side Effects:
**              none.
*/

bool
trusteduser(user)
        char *user;
{
        register char **ulist;
        extern char *TrustedUsers[];

        for (ulist = TrustedUsers; *ulist != NULL; ulist++)
                if (strcmp(*ulist, user) == 0)
                        return (TRUE);
        return (FALSE);
}