usr.sbin/sendmail/src/recipient.c

/*
 * Copyright (c) 1983 Eric P. Allman
 * Copyright (c) 1988, 1993
 *      The 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[] = "@(#)recipient.c 8.3 (Berkeley) 7/13/93";
#endif /* not lint */

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

/*
**  SENDTOLIST -- Designate a send list.
**
**      The parameter is a comma-separated list of people to send to.
**      This routine arranges to send to all of them.
**
**      Parameters:
**              list -- the send list.
**              ctladdr -- the address template for the person to
**                      send to -- effective uid/gid are important.
**                      This is typically the alias that caused this
**                      expansion.
**              sendq -- a pointer to the head of a queue to put
**                      these people into.
**              e -- the envelope in which to add these recipients.
**
**      Returns:
**              The number of addresses actually on the list.
**
**      Side Effects:
**              none.
*/

# define MAXRCRSN       10

sendtolist(list, ctladdr, sendq, e)
        char *list;
        ADDRESS *ctladdr;
        ADDRESS **sendq;
        register ENVELOPE *e;
{
        register char *p;
        register ADDRESS *al;   /* list of addresses to send to */
        bool firstone;          /* set on first address sent */
        char delimiter;         /* the address delimiter */
        int naddrs;

        if (tTd(25, 1))
        {
                printf("sendto: %s\n   ctladdr=", list);
                printaddr(ctladdr, FALSE);
        }

        /* heuristic to determine old versus new style addresses */
        if (ctladdr == NULL &&
            (strchr(list, ',') != NULL || strchr(list, ';') != NULL ||
             strchr(list, '<') != NULL || strchr(list, '(') != NULL))
                e->e_flags &= ~EF_OLDSTYLE;
        delimiter = ' ';
        if (!bitset(EF_OLDSTYLE, e->e_flags) || ctladdr != NULL)
                delimiter = ',';

        firstone = TRUE;
        al = NULL;
        naddrs = 0;

        for (p = list; *p != '\0'; )
        {
                auto char *delimptr;
                register ADDRESS *a;

                /* parse the address */
                while ((isascii(*p) && isspace(*p)) || *p == ',')
                        p++;
                a = parseaddr(p, (ADDRESS *) NULL, 1, delimiter, &delimptr, e);
                p = delimptr;
                if (a == NULL)
                        continue;
                a->q_next = al;
                a->q_alias = ctladdr;

                /* see if this should be marked as a primary address */
                if (ctladdr == NULL ||
                    (firstone && *p == '\0' && bitset(QPRIMARY, ctladdr->q_flags)))
                        a->q_flags |= QPRIMARY;

                if (ctladdr != NULL && sameaddr(ctladdr, a))
                        ctladdr->q_flags |= QSELFREF;
                al = a;
                firstone = FALSE;
        }

        /* arrange to send to everyone on the local send list */
        while (al != NULL)
        {
                register ADDRESS *a = al;

                al = a->q_next;
                a = recipient(a, sendq, e);

                /* arrange to inherit full name */
                if (a->q_fullname == NULL && ctladdr != NULL)
                        a->q_fullname = ctladdr->q_fullname;
                naddrs++;
        }

        e->e_to = NULL;
        return (naddrs);
}
\f/*
**  RECIPIENT -- Designate a message recipient
**
**      Saves the named person for future mailing.
**
**      Parameters:
**              a -- the (preparsed) address header for the recipient.
**              sendq -- a pointer to the head of a queue to put the
**                      recipient in.  Duplicate supression is done
**                      in this queue.
**              e -- the current envelope.
**
**      Returns:
**              The actual address in the queue.  This will be "a" if
**              the address is not a duplicate, else the original address.
**
**      Side Effects:
**              none.
*/

ADDRESS *
recipient(a, sendq, e)
        register ADDRESS *a;
        register ADDRESS **sendq;
        register ENVELOPE *e;
{
        register ADDRESS *q;
        ADDRESS **pq;
        register struct mailer *m;
        register char *p;
        bool quoted = FALSE;            /* set if the addr has a quote bit */
        int findusercount = 0;
        char buf[MAXNAME];              /* unquoted image of the user name */
        extern int safefile();

        e->e_to = a->q_paddr;
        m = a->q_mailer;
        errno = 0;
        if (tTd(26, 1))
        {
                printf("\nrecipient: ");
                printaddr(a, FALSE);
        }

        /* break aliasing loops */
        if (AliasLevel > MAXRCRSN)
        {
                usrerr("554 aliasing/forwarding loop broken");
                return (a);
        }

        /*
        **  Finish setting up address structure.
        */

        /* set the queue timeout */
        a->q_timeout = TimeOuts.to_q_return;

        /* get unquoted user for file, program or user.name check */
        (void) strcpy(buf, a->q_user);
        for (p = buf; *p != '\0' && !quoted; p++)
        {
                if (*p == '\\')
                        quoted = TRUE;
        }
        stripquotes(buf);

        /* check for direct mailing to restricted mailers */
        if (a->q_alias == NULL && m == ProgMailer &&
            !bitset(EF_QUEUERUN, e->e_flags))
        {
                a->q_flags |= QBADADDR;
                usrerr("550 Cannot mail directly to programs", m->m_name);
        }

        /*
        **  Look up this person in the recipient list.
        **      If they are there already, return, otherwise continue.
        **      If the list is empty, just add it.  Notice the cute
        **      hack to make from addresses suppress things correctly:
        **      the QDONTSEND bit will be set in the send list.
        **      [Please note: the emphasis is on "hack."]
        */

        for (pq = sendq; (q = *pq) != NULL; pq = &q->q_next)
        {
                if (sameaddr(q, a))
                {
                        if (tTd(26, 1))
                        {
                                printf("%s in sendq: ", a->q_paddr);
                                printaddr(q, FALSE);
                        }
                        if (!bitset(QPRIMARY, q->q_flags))
                        {
                                if (!bitset(QDONTSEND, a->q_flags))
                                        message("duplicate suppressed");
                                q->q_flags |= a->q_flags;
                        }
                        return (q);
                }
        }

        /* add address on list */
        *pq = a;
        a->q_next = NULL;

        /*
        **  Alias the name and handle special mailer types.
        */

  trylocaluser:
        if (tTd(29, 7))
                printf("at trylocaluser %s\n", a->q_user);

        if (bitset(QDONTSEND|QBADADDR|QVERIFIED, a->q_flags))
                return (a);

        if (m == InclMailer)
        {
                a->q_flags |= QDONTSEND;
                if (a->q_alias == NULL && !bitset(EF_QUEUERUN, e->e_flags))
                {
                        a->q_flags |= QBADADDR;
                        usrerr("550 Cannot mail directly to :include:s");
                }
                else
                {
                        int ret;

                        message("including file %s", a->q_user);
                        ret = include(a->q_user, FALSE, a, sendq, e);
                        if (transienterror(ret))
                        {
#ifdef LOG
                                if (LogLevel > 2)
                                        syslog(LOG_ERR, "%s: include %s: transient error: %e",
                                                e->e_id, a->q_user, errstring(ret));
#endif
                                a->q_flags |= QQUEUEUP|QDONTSEND;
                                usrerr("451 Cannot open %s: %s",
                                        a->q_user, errstring(ret));
                        }
                        else if (ret != 0)
                        {
                                usrerr("550 Cannot open %s: %s",
                                        a->q_user, errstring(ret));
                                a->q_flags |= QBADADDR;
                        }
                }
        }
        else if (m == FileMailer)
        {
                struct stat stb;
                extern bool writable();

                p = strrchr(buf, '/');
                /* check if writable or creatable */
                if (a->q_alias == NULL && !bitset(EF_QUEUERUN, e->e_flags))
                {
                        a->q_flags |= QBADADDR;
                        usrerr("550 Cannot mail directly to files");
                }
                else if ((stat(buf, &stb) >= 0) ? (!writable(&stb)) :
                    (*p = '\0', safefile(buf, RealUid, TRUE, S_IWRITE|S_IEXEC) != 0))
                {
                        a->q_flags |= QBADADDR;
                        giveresponse(EX_CANTCREAT, m, NULL, e);
                }
        }

        if (m != LocalMailer)
        {
                if (!bitset(QDONTSEND, a->q_flags))
                        e->e_nrcpts++;
                return (a);
        }

        /* try aliasing */
        alias(a, sendq, e);

# ifdef USERDB
        /* if not aliased, look it up in the user database */
        if (!bitset(QDONTSEND|QNOTREMOTE|QVERIFIED, a->q_flags))
        {
                extern int udbexpand();
                extern int errno;

                if (udbexpand(a, sendq, e) == EX_TEMPFAIL)
                {
                        a->q_flags |= QQUEUEUP|QDONTSEND;
                        if (e->e_message == NULL)
                                e->e_message = newstr("Deferred: user database error");
# ifdef LOG
                        if (LogLevel > 8)
                                syslog(LOG_INFO, "%s: deferred: udbexpand: %s",
                                        e->e_id, errstring(errno));
# endif
                        message("queued (user database error): %s",
                                errstring(errno));
                        e->e_nrcpts++;
                        return (a);
                }
        }
# endif

        /* if it was an alias or a UDB expansion, just return now */
        if (bitset(QDONTSEND|QQUEUEUP|QVERIFIED, a->q_flags))
                return (a);

        /*
        **  If we have a level two config file, then pass the name through
        **  Ruleset 5 before sending it off.  Ruleset 5 has the right
        **  to send rewrite it to another mailer.  This gives us a hook
        **  after local aliasing has been done.
        */

        if (tTd(29, 5))
        {
                printf("recipient: testing local?  cl=%d, rr5=%x\n\t",
                        ConfigLevel, RewriteRules[5]);
                printaddr(a, FALSE);
        }
        if (!bitset(QNOTREMOTE, a->q_flags) && ConfigLevel >= 2 &&
            RewriteRules[5] != NULL)
        {
                maplocaluser(a, sendq, e);
        }

        /*
        **  If it didn't get rewritten to another mailer, go ahead
        **  and deliver it.
        */

        if (!bitset(QDONTSEND|QQUEUEUP, a->q_flags))
        {
                auto bool fuzzy;
                register struct passwd *pw;
                extern struct passwd *finduser();

                /* warning -- finduser may trash buf */
                pw = finduser(buf, &fuzzy);
                if (pw == NULL)
                {
                        a->q_flags |= QBADADDR;
                        giveresponse(EX_NOUSER, m, NULL, e);
                }
                else
                {
                        char nbuf[MAXNAME];

                        if (fuzzy)
                        {
                                /* name was a fuzzy match */
                                a->q_user = newstr(pw->pw_name);
                                if (findusercount++ > 3)
                                {
                                        a->q_flags |= QBADADDR;
                                        usrerr("554 aliasing/forwarding loop for %s broken",
                                                pw->pw_name);
                                        return (a);
                                }

                                /* see if it aliases */
                                (void) strcpy(buf, pw->pw_name);
                                goto trylocaluser;
                        }
                        a->q_home = newstr(pw->pw_dir);
                        a->q_uid = pw->pw_uid;
                        a->q_gid = pw->pw_gid;
                        a->q_ruser = newstr(pw->pw_name);
                        a->q_flags |= QGOODUID;
                        buildfname(pw->pw_gecos, pw->pw_name, nbuf);
                        if (nbuf[0] != '\0')
                                a->q_fullname = newstr(nbuf);
                        if (!quoted)
                                forward(a, sendq, e);
                }
        }
        if (!bitset(QDONTSEND, a->q_flags))
                e->e_nrcpts++;
        return (a);
}
\f/*
**  FINDUSER -- find the password entry for a user.
**
**      This looks a lot like getpwnam, except that it may want to
**      do some fancier pattern matching in /etc/passwd.
**
**      This routine contains most of the time of many sendmail runs.
**      It deserves to be optimized.
**
**      Parameters:
**              name -- the name to match against.
**              fuzzyp -- an outarg that is set to TRUE if this entry
**                      was found using the fuzzy matching algorithm;
**                      set to FALSE otherwise.
**
**      Returns:
**              A pointer to a pw struct.
**              NULL if name is unknown or ambiguous.
**
**      Side Effects:
**              may modify name.
*/

struct passwd *
finduser(name, fuzzyp)
        char *name;
        bool *fuzzyp;
{
        register struct passwd *pw;
        register char *p;
        extern struct passwd *getpwent();
        extern struct passwd *getpwnam();

        if (tTd(29, 4))
                printf("finduser(%s): ", name);

        *fuzzyp = FALSE;

        /* look up this login name using fast path */
        if ((pw = getpwnam(name)) != NULL)
        {
                if (tTd(29, 4))
                        printf("found (non-fuzzy)\n");
                return (pw);
        }

#ifdef MATCHGECOS
        /* see if fuzzy matching allowed */
        if (!MatchGecos)
        {
                if (tTd(29, 4))
                        printf("not found (fuzzy disabled)\n");
                return NULL;
        }

        /* search for a matching full name instead */
        for (p = name; *p != '\0'; p++)
        {
                if (*p == (SpaceSub & 0177) || *p == '_')
                        *p = ' ';
        }
        (void) setpwent();
        while ((pw = getpwent()) != NULL)
        {
                char buf[MAXNAME];

                buildfname(pw->pw_gecos, pw->pw_name, buf);
                if (strchr(buf, ' ') != NULL && !strcasecmp(buf, name))
                {
                        if (tTd(29, 4))
                                printf("fuzzy matches %s\n", pw->pw_name);
                        message("sending to login name %s", pw->pw_name);
                        *fuzzyp = TRUE;
                        return (pw);
                }
        }
        if (tTd(29, 4))
                printf("no fuzzy match found\n");
#else
        if (tTd(29, 4))
                printf("not found (fuzzy disabled)\n");
#endif
        return (NULL);
}
\f/*
**  WRITABLE -- predicate returning if the file is writable.
**
**      This routine must duplicate the algorithm in sys/fio.c.
**      Unfortunately, we cannot use the access call since we
**      won't necessarily be the real uid when we try to
**      actually open the file.
**
**      Notice that ANY file with ANY execute bit is automatically
**      not writable.  This is also enforced by mailfile.
**
**      Parameters:
**              s -- pointer to a stat struct for the file.
**
**      Returns:
**              TRUE -- if we will be able to write this file.
**              FALSE -- if we cannot write this file.
**
**      Side Effects:
**              none.
*/

bool
writable(s)
        register struct stat *s;
{
        uid_t euid;
        gid_t egid;
        int bits;

        if (bitset(0111, s->st_mode))
                return (FALSE);
        euid = RealUid;
        egid = RealGid;
        if (geteuid() == 0)
        {
                if (bitset(S_ISUID, s->st_mode))
                        euid = s->st_uid;
                if (bitset(S_ISGID, s->st_mode))
                        egid = s->st_gid;
        }

        if (euid == 0)
                return (TRUE);
        bits = S_IWRITE;
        if (euid != s->st_uid)
        {
                bits >>= 3;
                if (egid != s->st_gid)
                        bits >>= 3;
        }
        return ((s->st_mode & bits) != 0);
}
\f/*
**  INCLUDE -- handle :include: specification.
**
**      Parameters:
**              fname -- filename to include.
**              forwarding -- if TRUE, we are reading a .forward file.
**                      if FALSE, it's a :include: file.
**              ctladdr -- address template to use to fill in these
**                      addresses -- effective user/group id are
**                      the important things.
**              sendq -- a pointer to the head of the send queue
**                      to put these addresses in.
**
**      Returns:
**              open error status
**
**      Side Effects:
**              reads the :include: file and sends to everyone
**              listed in that file.
*/

static jmp_buf  CtxIncludeTimeout;

int
include(fname, forwarding, ctladdr, sendq, e)
        char *fname;
        bool forwarding;
        ADDRESS *ctladdr;
        ADDRESS **sendq;
        ENVELOPE *e;
{
        register FILE *fp;
        char *oldto = e->e_to;
        char *oldfilename = FileName;
        int oldlinenumber = LineNumber;
        register EVENT *ev = NULL;
        int nincludes;
        int ret;
        ADDRESS *ca;
        uid_t uid;
        char buf[MAXLINE];
        static int includetimeout();

        if (tTd(27, 2))
                printf("include(%s)\n", fname);
        if (tTd(27, 14))
        {
                printf("ctladdr ");
                printaddr(ctladdr, FALSE);
        }

        /*
        **  If home directory is remote mounted but server is down,
        **  this can hang or give errors; use a timeout to avoid this
        */

        ca = getctladdr(ctladdr);
        if (ca == NULL)
                uid = 0;
        else
                uid = ca->q_uid;

        if (setjmp(CtxIncludeTimeout) != 0)
        {
                ctladdr->q_flags |= QQUEUEUP|QDONTSEND;
                errno = 0;
                usrerr("451 open timeout on %s", fname);
                return ETIMEDOUT;
        }
        ev = setevent((time_t) 60, includetimeout, 0);

        /* the input file must be marked safe */
        if ((ret = safefile(fname, uid, forwarding, S_IREAD)) != 0)
        {
                /* don't use this .forward file */
                clrevent(ev);
                if (tTd(27, 4))
                        printf("include: not safe (uid=%d): %s\n",
                                uid, errstring(ret));
                return ret;
        }

        fp = fopen(fname, "r");
        if (fp == NULL)
        {
                int ret = errno;

                clrevent(ev);
                return ret;
        }

        if (ca == NULL)
        {
                struct stat st;

                if (fstat(fileno(fp), &st) < 0)
                {
                        int ret = errno;

                        clrevent(ev);
                        syserr("Cannot fstat %s!", fname);
                        return ret;
                }
                ctladdr->q_uid = st.st_uid;
                ctladdr->q_gid = st.st_gid;
                ctladdr->q_flags |= QGOODUID;
        }

        clrevent(ev);

        if (bitset(EF_VRFYONLY, e->e_flags))
        {
                /* don't do any more now */
                ctladdr->q_flags |= QVERIFIED;
                e->e_nrcpts++;
                xfclose(fp, "include", fname);
                return 0;
        }

        /* read the file -- each line is a comma-separated list. */
        FileName = fname;
        LineNumber = 0;
        ctladdr->q_flags &= ~QSELFREF;
        nincludes = 0;
        while (fgets(buf, sizeof buf, fp) != NULL)
        {
                register char *p = strchr(buf, '\n');

                LineNumber++;
                if (p != NULL)
                        *p = '\0';
                if (buf[0] == '#' || buf[0] == '\0')
                        continue;
                e->e_to = NULL;
                message("%s to %s",
                        forwarding ? "forwarding" : "sending", buf);
#ifdef LOG
                if (forwarding && LogLevel > 9)
                        syslog(LOG_INFO, "%s: forward %s => %s",
                                e->e_id, oldto, buf);
#endif

                AliasLevel++;
                nincludes += sendtolist(buf, ctladdr, sendq, e);
                AliasLevel--;
        }
        if (nincludes > 0 && !bitset(QSELFREF, ctladdr->q_flags))
        {
                if (tTd(27, 5))
                {
                        printf("include: QDONTSEND ");
                        printaddr(ctladdr, FALSE);
                }
                ctladdr->q_flags |= QDONTSEND;
        }

        (void) xfclose(fp, "include", fname);
        FileName = oldfilename;
        LineNumber = oldlinenumber;
        return 0;
}

static
includetimeout()
{
        longjmp(CtxIncludeTimeout, 1);
}
\f/*
**  SENDTOARGV -- send to an argument vector.
**
**      Parameters:
**              argv -- argument vector to send to.
**              e -- the current envelope.
**
**      Returns:
**              none.
**
**      Side Effects:
**              puts all addresses on the argument vector onto the
**                      send queue.
*/

sendtoargv(argv, e)
        register char **argv;
        register ENVELOPE *e;
{
        register char *p;

        while ((p = *argv++) != NULL)
        {
                (void) sendtolist(p, (ADDRESS *) NULL, &e->e_sendqueue, e);
        }
}
\f/*
**  GETCTLADDR -- get controlling address from an address header.
**
**      If none, get one corresponding to the effective userid.
**
**      Parameters:
**              a -- the address to find the controller of.
**
**      Returns:
**              the controlling address.
**
**      Side Effects:
**              none.
*/

ADDRESS *
getctladdr(a)
        register ADDRESS *a;
{
        while (a != NULL && !bitset(QGOODUID, a->q_flags))
                a = a->q_alias;
        return (a);
}