Annotation of 43BSDReno/libexec/talkd/process.c, revision 1.1

1.1     ! root        1: /*
        !             2:  * Copyright (c) 1983 Regents of the University of California.
        !             3:  * All rights reserved.
        !             4:  *
        !             5:  * Redistribution and use in source and binary forms are permitted
        !             6:  * provided that: (1) source distributions retain this entire copyright
        !             7:  * notice and comment, and (2) distributions including binaries display
        !             8:  * the following acknowledgement:  ``This product includes software
        !             9:  * developed by the University of California, Berkeley and its contributors''
        !            10:  * in the documentation or other materials provided with the distribution
        !            11:  * and in all advertising materials mentioning features or use of this
        !            12:  * software. Neither the name of the University nor the names of its
        !            13:  * contributors may be used to endorse or promote products derived
        !            14:  * from this software without specific prior written permission.
        !            15:  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
        !            16:  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
        !            17:  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
        !            18:  */
        !            19: 
        !            20: #ifndef lint
        !            21: static char sccsid[] = "@(#)process.c  5.9 (Berkeley) 6/1/90";
        !            22: #endif /* not lint */
        !            23: 
        !            24: /*
        !            25:  * process.c handles the requests, which can be of three types:
        !            26:  *     ANNOUNCE - announce to a user that a talk is wanted
        !            27:  *     LEAVE_INVITE - insert the request into the table
        !            28:  *     LOOK_UP - look up to see if a request is waiting in
        !            29:  *               in the table for the local user
        !            30:  *     DELETE - delete invitation
        !            31:  */
        !            32: #include <sys/types.h>
        !            33: #include <sys/stat.h>
        !            34: #include <stdio.h>
        !            35: #include <syslog.h>
        !            36: #include <netdb.h>
        !            37: #include <netinet/in.h>
        !            38: 
        !            39: #include <protocols/talkd.h>
        !            40: #include <paths.h>
        !            41: 
        !            42: char   *strcpy();
        !            43: CTL_MSG *find_request();
        !            44: CTL_MSG *find_match();
        !            45: 
        !            46: process_request(mp, rp)
        !            47:        register CTL_MSG *mp;
        !            48:        register CTL_RESPONSE *rp;
        !            49: {
        !            50:        register CTL_MSG *ptr;
        !            51:        extern int debug;
        !            52: 
        !            53:        rp->vers = TALK_VERSION;
        !            54:        rp->type = mp->type;
        !            55:        rp->id_num = htonl(0);
        !            56:        if (mp->vers != TALK_VERSION) {
        !            57:                syslog(LOG_WARNING, "Bad protocol version %d", mp->vers);
        !            58:                rp->answer = BADVERSION;
        !            59:                return;
        !            60:        }
        !            61:        mp->id_num = ntohl(mp->id_num);
        !            62:        mp->addr.sa_family = ntohs(mp->addr.sa_family);
        !            63:        if (mp->addr.sa_family != AF_INET) {
        !            64:                syslog(LOG_WARNING, "Bad address, family %d",
        !            65:                    mp->addr.sa_family);
        !            66:                rp->answer = BADADDR;
        !            67:                return;
        !            68:        }
        !            69:        mp->ctl_addr.sa_family = ntohs(mp->ctl_addr.sa_family);
        !            70:        if (mp->ctl_addr.sa_family != AF_INET) {
        !            71:                syslog(LOG_WARNING, "Bad control address, family %d",
        !            72:                    mp->ctl_addr.sa_family);
        !            73:                rp->answer = BADCTLADDR;
        !            74:                return;
        !            75:        }
        !            76:        mp->pid = ntohl(mp->pid);
        !            77:        if (debug)
        !            78:                print_request("process_request", mp);
        !            79:        switch (mp->type) {
        !            80: 
        !            81:        case ANNOUNCE:
        !            82:                do_announce(mp, rp);
        !            83:                break;
        !            84: 
        !            85:        case LEAVE_INVITE:
        !            86:                ptr = find_request(mp);
        !            87:                if (ptr != (CTL_MSG *)0) {
        !            88:                        rp->id_num = htonl(ptr->id_num);
        !            89:                        rp->answer = SUCCESS;
        !            90:                } else
        !            91:                        insert_table(mp, rp);
        !            92:                break;
        !            93: 
        !            94:        case LOOK_UP:
        !            95:                ptr = find_match(mp);
        !            96:                if (ptr != (CTL_MSG *)0) {
        !            97:                        rp->id_num = htonl(ptr->id_num);
        !            98:                        rp->addr = ptr->addr;
        !            99:                        rp->addr.sa_family = htons(ptr->addr.sa_family);
        !           100:                        rp->answer = SUCCESS;
        !           101:                } else
        !           102:                        rp->answer = NOT_HERE;
        !           103:                break;
        !           104: 
        !           105:        case DELETE:
        !           106:                rp->answer = delete_invite(mp->id_num);
        !           107:                break;
        !           108: 
        !           109:        default:
        !           110:                rp->answer = UNKNOWN_REQUEST;
        !           111:                break;
        !           112:        }
        !           113:        if (debug)
        !           114:                print_response("process_request", rp);
        !           115: }
        !           116: 
        !           117: do_announce(mp, rp)
        !           118:        register CTL_MSG *mp;
        !           119:        CTL_RESPONSE *rp;
        !           120: {
        !           121:        struct hostent *hp;
        !           122:        CTL_MSG *ptr;
        !           123:        int result;
        !           124: 
        !           125:        /* see if the user is logged */
        !           126:        result = find_user(mp->r_name, mp->r_tty);
        !           127:        if (result != SUCCESS) {
        !           128:                rp->answer = result;
        !           129:                return;
        !           130:        }
        !           131: #define        satosin(sa)     ((struct sockaddr_in *)(sa))
        !           132:        hp = gethostbyaddr(&satosin(&mp->ctl_addr)->sin_addr,
        !           133:                sizeof (struct in_addr), AF_INET);
        !           134:        if (hp == (struct hostent *)0) {
        !           135:                rp->answer = MACHINE_UNKNOWN;
        !           136:                return;
        !           137:        }
        !           138:        ptr = find_request(mp);
        !           139:        if (ptr == (CTL_MSG *) 0) {
        !           140:                insert_table(mp, rp);
        !           141:                rp->answer = announce(mp, hp->h_name);
        !           142:                return;
        !           143:        }
        !           144:        if (mp->id_num > ptr->id_num) {
        !           145:                /*
        !           146:                 * This is an explicit re-announce, so update the id_num
        !           147:                 * field to avoid duplicates and re-announce the talk.
        !           148:                 */
        !           149:                ptr->id_num = new_id();
        !           150:                rp->id_num = htonl(ptr->id_num);
        !           151:                rp->answer = announce(mp, hp->h_name);
        !           152:        } else {
        !           153:                /* a duplicated request, so ignore it */
        !           154:                rp->id_num = htonl(ptr->id_num);
        !           155:                rp->answer = SUCCESS;
        !           156:        }
        !           157: }
        !           158: 
        !           159: #include <utmp.h>
        !           160: 
        !           161: /*
        !           162:  * Search utmp for the local user
        !           163:  */
        !           164: find_user(name, tty)
        !           165:        char *name, *tty;
        !           166: {
        !           167:        struct utmp ubuf;
        !           168:        int status;
        !           169:        FILE *fd;
        !           170:        struct stat statb;
        !           171:        char ftty[20];
        !           172: 
        !           173:        if ((fd = fopen(_PATH_UTMP, "r")) == NULL) {
        !           174:                fprintf(stderr, "talkd: can't read %s.\n", _PATH_UTMP);
        !           175:                return (FAILED);
        !           176:        }
        !           177: #define SCMPN(a, b)    strncmp(a, b, sizeof (a))
        !           178:        status = NOT_HERE;
        !           179:        (void) strcpy(ftty, _PATH_DEV);
        !           180:        while (fread((char *) &ubuf, sizeof ubuf, 1, fd) == 1)
        !           181:                if (SCMPN(ubuf.ut_name, name) == 0) {
        !           182:                        if (*tty == '\0') {
        !           183:                                status = PERMISSION_DENIED;
        !           184:                                /* no particular tty was requested */
        !           185:                                (void) strcpy(ftty+5, ubuf.ut_line);
        !           186:                                if (stat(ftty,&statb) == 0) {
        !           187:                                        if (!(statb.st_mode & 020))
        !           188:                                                continue;
        !           189:                                        (void) strcpy(tty, ubuf.ut_line);
        !           190:                                        status = SUCCESS;
        !           191:                                        break;
        !           192:                                }
        !           193:                        }
        !           194:                        if (strcmp(ubuf.ut_line, tty) == 0) {
        !           195:                                status = SUCCESS;
        !           196:                                break;
        !           197:                        }
        !           198:                }
        !           199:        fclose(fd);
        !           200:        return (status);
        !           201: }

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