Annotation of 43BSDReno/libexec/talkd/process.c, revision 1.1.1.1

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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