usr/src/usr.bin/vacation/vacation.c

/*
 * Copyright (c) 1983, 1987 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1983, 1987 Regents of the University of California.\n\
 All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)vacation.c  5.13 (Berkeley) %G%";
#endif /* not lint */

/*
**  Vacation
**  Copyright (c) 1983  Eric P. Allman
**  Berkeley, California
*/

#include <sys/param.h>
#include <sys/file.h>
#include <pwd.h>
#include <ndbm.h>
#include <syslog.h>
#include <tzfile.h>
#include <stdio.h>
#include <ctype.h>

/*
 *  VACATION -- return a message to the sender when on vacation.
 *
 *      This program is invoked as a message receiver.  It returns a
 *      message specified by the user to whomever sent the mail, taking
 *      care not to return a message too often to prevent "I am on
 *      vacation" loops.
 */

#define MAXLINE 500                     /* max line from mail header */
#define VMSG    ".vacation.msg"         /* vacation message */
#define VACAT   ".vacation"             /* dbm's database prefix */
#define VDIR    ".vacation.dir"         /* dbm's DB prefix, part 1 */
#define VPAG    ".vacation.pag"         /* dbm's DB prefix, part 2 */

typedef struct alias {
        struct alias *next;
        char *name;
} ALIAS;
ALIAS *names;

static DBM *db;

extern int errno;

#define VIT     "__VACATION__INTERVAL__TIMER__"
static char from[MAXLINE];

main(argc, argv)
        int argc;
        char **argv;
{
        extern int optind, opterr;
        extern char *optarg;
        struct passwd *pw;
        ALIAS *cur;
        time_t interval;
        int ch, iflag;
        char *malloc();
        uid_t getuid();
        long atol();

        opterr = iflag = 0;
        interval = -1;
        while ((ch = getopt(argc, argv, "a:Iir:")) != EOF)
                switch((char)ch) {
                case 'a':                       /* alias */
                        if (!(cur = (ALIAS *)malloc((u_int)sizeof(ALIAS))))
                                break;
                        cur->name = optarg;
                        cur->next = names;
                        names = cur;
                        break;
                case 'I':                       /* backward compatible */
                case 'i':                       /* init the database */
                        iflag = 1;
                        break;
                case 'r':
                        if (isdigit(*optarg)) {
                                interval = atol(optarg) * SECSPERDAY;
                                if (interval < 0)
                                        goto usage;
                        }
                        else
                                interval = LONG_MAX;
                        break;
                case '?':
                default:
                        goto usage;
                }
        argc -= optind;
        argv += optind;

        if (argc != 1) {
                if (!iflag) {
usage:                  syslog(LOG_NOTICE, "uid %u: usage: vacation [-i] [-a alias] login\n", getuid());
                        myexit(1);
                }
                if (!(pw = getpwuid(getuid()))) {
                        syslog(LOG_ERR, "vacation: no such user uid %u.\n", getuid());
                        myexit(1);
                }
        }
        else if (!(pw = getpwnam(*argv))) {
                syslog(LOG_ERR, "vacation: no such user %s.\n", *argv);
                myexit(1);
        }
        if (chdir(pw->pw_dir)) {
                syslog(LOG_NOTICE, "vacation: no such directory %s.\n", pw->pw_dir);
                myexit(1);
        }

        if (iflag || access(VDIR, F_OK))
                initialize();
        if (!(db = dbm_open(VACAT, O_RDWR, 0))) {
                syslog(LOG_NOTICE, "vacation: %s: %s\n", VACAT,
                    strerror(errno));
                myexit(1);
        }

        if (interval != -1)
                setinterval(interval);
        if (iflag)
                myexit(0);

        if (!(cur = (ALIAS *)malloc((u_int)sizeof(ALIAS))))
                myexit(1);
        cur->name = pw->pw_name;
        cur->next = names;
        names = cur;

        readheaders();

        if (!recent()) {
                setreply();
                sendmessage(pw->pw_name);
        }
        myexit(0);
        /* NOTREACHED */
}

/*
 * readheaders --
 *      read mail headers
 */
getfrom(shortp)
char **shortp;
{
        register ALIAS *cur;
        register char *p;
        int tome, cont;
        char buf[MAXLINE], *strcpy(), *index();

        cont = tome = 0;
        while (fgets(buf, sizeof(buf), stdin) && *buf != '\n')
                switch(*buf) {
                case 'F':               /* "From " */
                        cont = 0;
                        if (!strncmp(buf, "From ", 5)) {
                                for (p = buf + 5; *p && *p != ' '; ++p);
                                *p = '\0';
                                (void)strcpy(from, buf + 5);
                                if (p = index(from, '\n'))
                                        *p = '\0';
                                if (junkmail())
                                        myexit(0);
                        }
                        break;
                case 'P':               /* "Precedence:" */
                        cont = 0;
                        if (strncasecmp(buf, "Precedence", 10) || buf[10] != ':' && buf[10] != ' ' && buf[10] != '\t')
                                break;
                        if (!(p = index(buf, ':')))
                                break;
                        while (*++p && isspace(*p));
                        if (!*p)
                                break;
                        if (!strncasecmp(p, "junk", 4) || !strncasecmp(p, "bulk", 4))
                                myexit(0);
                        break;
                case 'C':               /* "Cc:" */
                        if (strncmp(buf, "Cc:", 3))
                                break;
                        cont = 1;
                        goto findme;
                case 'T':               /* "To:" */
                        if (strncmp(buf, "To:", 3))
                                break;
                        cont = 1;
                        goto findme;
                default:
                        if (!isspace(*buf) || !cont || tome) {
                                cont = 0;
                                break;
                        }
findme:                 for (cur = names; !tome && cur; cur = cur->next)
                                tome += nsearch(cur->name, buf);
                }
        if (!tome)
                myexit(0);
        if (!*from) {
                syslog(LOG_NOTICE, "vacation: no initial \"From\" line.\n");
                myexit(1);
        }
}

        return start;
}

/*
 * junkmail --
 *      read the header and return if automagic/junk/bulk mail
 */
junkmail()
{
        static struct ignore {
                char    *name;
                int     len;
        } ignore[] = {
                "-request", 8,          "postmaster", 10,       "uucp", 4,
                "mailer-daemon", 13,    "mailer", 6,            "-relay", 6,
                NULL, NULL,
        };
        register struct ignore *cur;
        register int len;
        register char *p;
        char *index(), *rindex();

        /*
         * This is mildly amusing, and I'm not positive it's right; trying
         * to find the "real" name of the sender, assuming that addresses
         * will be some variant of:
         *
         * From site!site!SENDER%site.domain%site.domain@site.domain
         */
        if (!(p = index(from, '%')))
                if (!(p = index(from, '@'))) {
                        if (p = rindex(from, '!'))
                                ++p;
                        else
                                p = from;
                        for (; *p; ++p);
                }
        len = p - from;
        for (cur = ignore; cur->name; ++cur)
                if (len >= cur->len && !strncasecmp(cur->name, p - cur->len, cur->len))
                        return(1);
        return(0);
}

/*
 * recent --
 *      find out if user has gotten a vacation message recently.
 *      use bcopy for machines with alignment restrictions
 */
char *user;
{
        datum key, data;
        time_t then, next, time();

        if (d.dptr == NULL)
                return FALSE;
        bcopy(d.dptr, (char *)&ldbrec, sizeof ldbrec);  /* realign data */
        return ldbrec.sentdate + Timeout >= time((time_t *)0);
}

#ifndef VMUNIX
bcopy(from, to, size)
register char *to, *from;
register unsigned size;
{
        while (size-- > 0)
                *to++ = *from++;
}
#endif

/*
 * setinterval --
 *      store the reply interval
 */
setinterval(interval)
        time_t interval;
{
        datum key, data;

        key.dptr = VIT;
        key.dsize = sizeof(VIT) - 1;
        data.dptr = (char *)&interval;
        data.dsize = sizeof(interval);
        dbm_store(db, key, data, DBM_REPLACE);
}

/*
 * setreply --
 *      store that this user knows about the vacation.
 */
setreply()
{
        datum key, data;
        time_t now, time();

        key.dptr = from;
        key.dsize = strlen(from);
        (void)time(&now);
        data.dptr = (char *)&now;
        data.dsize = sizeof(now);
        dbm_store(db, key, data, DBM_REPLACE);
}

/*
 * sendmessage --
 *      exec sendmail to send the vacation file to sender
 */
sendmessage(myname)
        char *myname;
{
        if (!freopen(VMSG, "r", stdin)) {
                syslog(LOG_NOTICE, "vacation: no ~%s/%s file.\n", myname, VMSG);
                myexit(1);
        }
        execl("/usr/lib/sendmail", "sendmail", "-f", myname, from, NULL);
        syslog(LOG_ERR, "vacation: can't exec /usr/lib/sendmail.\n");
        myexit(1);
}

/*
 * initialize --
 *      initialize the dbm database
 */
initialize()
{
        int fd;

        if ((fd = open(VDIR, O_WRONLY|O_CREAT|O_TRUNC, 0644)) < 0) {
                syslog(LOG_NOTICE, "vacation: %s: %s\n", VDIR, strerror(errno));
                exit(1);
        }
        (void)close(fd);
        if ((fd = open(VPAG, O_WRONLY|O_CREAT|O_TRUNC, 0644)) < 0) {
                syslog(LOG_NOTICE, "vacation: %s: %s\n", VPAG, strerror(errno));
                exit(1);
        }
        (void)close(fd);
}

/*
 * myexit --
 *      we're outta here...
 */
myexit(eval)
        int eval;
{
        if (db)
                dbm_close(db);
        exit(eval);
}