Annotation of 43BSDReno/libexec/comsat/comsat.c, revision 1.1.1.1

1.1       root        1: /*
                      2:  * Copyright (c) 1980 Regents of the University of California.
                      3:  * All rights reserved.
                      4:  *
                      5:  * Redistribution and use in source and binary forms are permitted provided
                      6:  * that: (1) source distributions retain this entire copyright notice and
                      7:  * comment, and (2) distributions including binaries display the following
                      8:  * acknowledgement:  ``This product includes software developed by the
                      9:  * University of California, Berkeley and its contributors'' in the
                     10:  * documentation or other materials provided with the distribution and in
                     11:  * all advertising materials mentioning features or use of this software.
                     12:  * Neither the name of the University nor the names of its contributors may
                     13:  * be used to endorse or promote products derived from this software without
                     14:  * specific prior written permission.
                     15:  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
                     16:  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
                     17:  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
                     18:  */
                     19: 
                     20: #ifndef lint
                     21: char copyright[] =
                     22: "@(#) Copyright (c) 1980 Regents of the University of California.\n\
                     23:  All rights reserved.\n";
                     24: #endif /* not lint */
                     25: 
                     26: #ifndef lint
                     27: static char sccsid[] = "@(#)comsat.c   5.22 (Berkeley) 6/24/90";
                     28: #endif /* not lint */
                     29: 
                     30: #include <sys/param.h>
                     31: #include <sys/socket.h>
                     32: #include <sys/stat.h>
                     33: #include <sys/file.h>
                     34: #include <sys/wait.h>
                     35: 
                     36: #include <netinet/in.h>
                     37: 
                     38: #include <stdio.h>
                     39: #include <sgtty.h>
                     40: #include <utmp.h>
                     41: #include <signal.h>
                     42: #include <errno.h>
                     43: #include <netdb.h>
                     44: #include <syslog.h>
                     45: #include <ctype.h>
                     46: #include <string.h>
                     47: #include <paths.h>
                     48: 
                     49: int    debug = 0;
                     50: #define        dsyslog if (debug) syslog
                     51: 
                     52: #define MAXIDLE        120
                     53: 
                     54: char   hostname[MAXHOSTNAMELEN];
                     55: struct utmp *utmp = NULL;
                     56: time_t lastmsgtime, time();
                     57: int    nutmp, uf;
                     58: 
                     59: /* ARGSUSED */
                     60: main(argc, argv)
                     61:        int argc;
                     62:        char **argv;
                     63: {
                     64:        extern int errno;
                     65:        register int cc;
                     66:        char msgbuf[100];
                     67:        struct sockaddr_in from;
                     68:        int fromlen;
                     69:        void onalrm(), reapchildren();
                     70: 
                     71:        /* verify proper invocation */
                     72:        fromlen = sizeof(from);
                     73:        if (getsockname(0, &from, &fromlen) < 0) {
                     74:                (void)fprintf(stderr,
                     75:                    "comsat: getsockname: %s.\n", strerror(errno));
                     76:                exit(1);
                     77:        }
                     78:        openlog("comsat", LOG_PID, LOG_DAEMON);
                     79:        if (chdir(_PATH_MAILDIR)) {
                     80:                syslog(LOG_ERR, "chdir: %s: %m", _PATH_MAILDIR);
                     81:                exit(1);
                     82:        }
                     83:        if ((uf = open(_PATH_UTMP, O_RDONLY, 0)) < 0) {
                     84:                syslog(LOG_ERR, ".main: %s: %m", _PATH_UTMP);
                     85:                (void) recv(0, msgbuf, sizeof(msgbuf) - 1, 0);
                     86:                exit(1);
                     87:        }
                     88:        (void)time(&lastmsgtime);
                     89:        (void)gethostname(hostname, sizeof(hostname));
                     90:        onalrm();
                     91:        (void)signal(SIGALRM, onalrm);
                     92:        (void)signal(SIGTTOU, SIG_IGN);
                     93:        (void)signal(SIGCHLD, reapchildren);
                     94:        for (;;) {
                     95:                cc = recv(0, msgbuf, sizeof(msgbuf) - 1, 0);
                     96:                if (cc <= 0) {
                     97:                        if (errno != EINTR)
                     98:                                sleep(1);
                     99:                        errno = 0;
                    100:                        continue;
                    101:                }
                    102:                if (!nutmp)             /* no one has logged in yet */
                    103:                        continue;
                    104:                sigblock(sigmask(SIGALRM));
                    105:                msgbuf[cc] = 0;
                    106:                (void)time(&lastmsgtime);
                    107:                mailfor(msgbuf);
                    108:                sigsetmask(0L);
                    109:        }
                    110: }
                    111: 
                    112: void
                    113: reapchildren()
                    114: {
                    115:        while (wait3((union wait *)NULL, WNOHANG, (struct rusage *)NULL) > 0);
                    116: }
                    117: 
                    118: void
                    119: onalrm()
                    120: {
                    121:        static u_int utmpsize;          /* last malloced size for utmp */
                    122:        static u_int utmpmtime;         /* last modification time for utmp */
                    123:        struct stat statbf;
                    124:        off_t lseek();
                    125:        char *malloc(), *realloc();
                    126: 
                    127:        if (time((time_t *)NULL) - lastmsgtime >= MAXIDLE)
                    128:                exit(0);
                    129:        (void)alarm((u_int)15);
                    130:        (void)fstat(uf, &statbf);
                    131:        if (statbf.st_mtime > utmpmtime) {
                    132:                utmpmtime = statbf.st_mtime;
                    133:                if (statbf.st_size > utmpsize) {
                    134:                        utmpsize = statbf.st_size + 10 * sizeof(struct utmp);
                    135:                        if (utmp)
                    136:                                utmp = (struct utmp *)realloc((char *)utmp, utmpsize);
                    137:                        else
                    138:                                utmp = (struct utmp *)malloc(utmpsize);
                    139:                        if (!utmp) {
                    140:                                syslog(LOG_ERR, "malloc failed");
                    141:                                exit(1);
                    142:                        }
                    143:                }
                    144:                (void)lseek(uf, 0L, L_SET);
                    145:                nutmp = read(uf, utmp, (int)statbf.st_size)/sizeof(struct utmp);
                    146:        }
                    147: }
                    148: 
                    149: mailfor(name)
                    150:        char *name;
                    151: {
                    152:        register struct utmp *utp = &utmp[nutmp];
                    153:        register char *cp;
                    154:        off_t offset;
                    155: 
                    156:        if (!(cp = index(name, '@')))
                    157:                return;
                    158:        *cp = '\0';
                    159:        offset = atoi(cp + 1);
                    160:        while (--utp >= utmp)
                    161:                if (!strncmp(utp->ut_name, name, sizeof(utmp[0].ut_name)))
                    162:                        notify(utp, offset);
                    163: }
                    164: 
                    165: static char *cr;
                    166: 
                    167: notify(utp, offset)
                    168:        register struct utmp *utp;
                    169:        off_t offset;
                    170: {
                    171:        static char tty[20] = _PATH_DEV;
                    172:        struct sgttyb gttybuf;
                    173:        struct stat stb;
                    174:        FILE *tp;
                    175:        char name[sizeof(utmp[0].ut_name) + 1];
                    176: 
                    177:        (void)strncpy(tty + sizeof(_PATH_DEV) - 1, utp->ut_line,
                    178:            sizeof(utp->ut_line));
                    179:        if (stat(tty, &stb) || !(stb.st_mode & S_IEXEC)) {
                    180:                dsyslog(LOG_DEBUG, "%s: wrong mode on %s", utp->ut_name, tty);
                    181:                return;
                    182:        }
                    183:        dsyslog(LOG_DEBUG, "notify %s on %s\n", utp->ut_name, tty);
                    184:        if (fork())
                    185:                return;
                    186:        (void)signal(SIGALRM, SIG_DFL);
                    187:        (void)alarm((u_int)30);
                    188:        if ((tp = fopen(tty, "w")) == NULL) {
                    189:                dsyslog(LOG_ERR, "fopen of tty %s failed", tty);
                    190:                _exit(-1);
                    191:        }
                    192:        (void)ioctl(fileno(tp), TIOCGETP, &gttybuf);
                    193:        cr = (gttybuf.sg_flags&CRMOD) && !(gttybuf.sg_flags&RAW) ?
                    194:            "\n" : "\n\r";
                    195:        (void)strncpy(name, utp->ut_name, sizeof(utp->ut_name));
                    196:        name[sizeof(name) - 1] = '\0';
                    197:        (void)fprintf(tp, "%s\007New mail for %s@%.*s\007 has arrived:%s----%s",
                    198:            cr, name, sizeof(hostname), hostname, cr, cr);
                    199:        jkfprintf(tp, name, offset);
                    200:        (void)fclose(tp);
                    201:        _exit(0);
                    202: }
                    203: 
                    204: jkfprintf(tp, name, offset)
                    205:        register FILE *tp;
                    206:        char name[];
                    207:        off_t offset;
                    208: {
                    209:        register char *cp, ch;
                    210:        register FILE *fi;
                    211:        register int linecnt, charcnt, inheader;
                    212:        char line[BUFSIZ];
                    213:        off_t fseek();
                    214: 
                    215:        if ((fi = fopen(name, "r")) == NULL)
                    216:                return;
                    217:        (void)fseek(fi, offset, L_SET);
                    218:        /*
                    219:         * Print the first 7 lines or 560 characters of the new mail
                    220:         * (whichever comes first).  Skip header crap other than
                    221:         * From, Subject, To, and Date.
                    222:         */
                    223:        linecnt = 7;
                    224:        charcnt = 560;
                    225:        inheader = 1;
                    226:        while (fgets(line, sizeof(line), fi) != NULL) {
                    227:                if (inheader) {
                    228:                        if (line[0] == '\n') {
                    229:                                inheader = 0;
                    230:                                continue;
                    231:                        }
                    232:                        if (line[0] == ' ' || line[0] == '\t' ||
                    233:                            strncmp(line, "From:", 5) &&
                    234:                            strncmp(line, "Subject:", 8))
                    235:                                continue;
                    236:                }
                    237:                if (linecnt <= 0 || charcnt <= 0) {
                    238:                        (void)fprintf(tp, "...more...%s", cr);
                    239:                        return;
                    240:                }
                    241:                /* strip weird stuff so can't trojan horse stupid terminals */
                    242:                for (cp = line; (ch = *cp) && ch != '\n'; ++cp, --charcnt) {
                    243:                        ch = toascii(ch);
                    244:                        if (!isprint(ch) && !isspace(ch))
                    245:                                ch |= 0x40;
                    246:                        (void)fputc(ch, tp);
                    247:                }
                    248:                (void)fputs(cr, tp);
                    249:                --linecnt;
                    250:        }
                    251:        (void)fprintf(tp, "----%s\n", cr);
                    252: }

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