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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 the above copyright notice and this paragraph are
7: * duplicated in all such forms and that any documentation,
8: * advertising materials, and other materials related to such
9: * distribution and use acknowledge that the software was developed
10: * by the University of California, Berkeley. The name of the
11: * University may not be used to endorse or promote products derived
12: * from this software without specific prior written permission.
13: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
14: * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
15: * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
16: */
17:
18: #ifndef lint
19: static char sccsid[] = "@(#)process.c 5.6 (Berkeley) 6/18/88";
20: #endif /* not lint */
21:
22: /*
23: * process.c handles the requests, which can be of three types:
24: * ANNOUNCE - announce to a user that a talk is wanted
25: * LEAVE_INVITE - insert the request into the table
26: * LOOK_UP - look up to see if a request is waiting in
27: * in the table for the local user
28: * DELETE - delete invitation
29: */
30: #include <sys/types.h>
31: #include <sys/stat.h>
32: #include <stdio.h>
33: #include <syslog.h>
34: #include <netdb.h>
35: #include <netinet/in.h>
36:
37: #include <protocols/talkd.h>
38:
39: char *strcpy();
40: CTL_MSG *find_request();
41: CTL_MSG *find_match();
42:
43: process_request(mp, rp)
44: register CTL_MSG *mp;
45: register CTL_RESPONSE *rp;
46: {
47: register CTL_MSG *ptr;
48: extern int debug;
49:
50: rp->vers = TALK_VERSION;
51: rp->type = mp->type;
52: rp->id_num = htonl(0);
53: if (mp->vers != TALK_VERSION) {
54: syslog(LOG_WARNING, "Bad protocol version %d", mp->vers);
55: rp->answer = BADVERSION;
56: return;
57: }
58: mp->id_num = ntohl(mp->id_num);
59: mp->addr.sa_family = ntohs(mp->addr.sa_family);
60: if (mp->addr.sa_family != AF_INET) {
61: syslog(LOG_WARNING, "Bad address, family %d",
62: mp->addr.sa_family);
63: rp->answer = BADADDR;
64: return;
65: }
66: mp->ctl_addr.sa_family = ntohs(mp->ctl_addr.sa_family);
67: if (mp->ctl_addr.sa_family != AF_INET) {
68: syslog(LOG_WARNING, "Bad control address, family %d",
69: mp->ctl_addr.sa_family);
70: rp->answer = BADCTLADDR;
71: return;
72: }
73: mp->pid = ntohl(mp->pid);
74: if (debug)
75: print_request("process_request", mp);
76: switch (mp->type) {
77:
78: case ANNOUNCE:
79: do_announce(mp, rp);
80: break;
81:
82: case LEAVE_INVITE:
83: ptr = find_request(mp);
84: if (ptr != (CTL_MSG *)0) {
85: rp->id_num = htonl(ptr->id_num);
86: rp->answer = SUCCESS;
87: } else
88: insert_table(mp, rp);
89: break;
90:
91: case LOOK_UP:
92: ptr = find_match(mp);
93: if (ptr != (CTL_MSG *)0) {
94: rp->id_num = htonl(ptr->id_num);
95: rp->addr = ptr->addr;
96: rp->addr.sa_family = htons(ptr->addr.sa_family);
97: rp->answer = SUCCESS;
98: } else
99: rp->answer = NOT_HERE;
100: break;
101:
102: case DELETE:
103: rp->answer = delete_invite(mp->id_num);
104: break;
105:
106: default:
107: rp->answer = UNKNOWN_REQUEST;
108: break;
109: }
110: if (debug)
111: print_response("process_request", rp);
112: }
113:
114: do_announce(mp, rp)
115: register CTL_MSG *mp;
116: CTL_RESPONSE *rp;
117: {
118: struct hostent *hp;
119: CTL_MSG *ptr;
120: int result;
121:
122: /* see if the user is logged */
123: result = find_user(mp->r_name, mp->r_tty);
124: if (result != SUCCESS) {
125: rp->answer = result;
126: return;
127: }
128: #define satosin(sa) ((struct sockaddr_in *)(sa))
129: hp = gethostbyaddr(&satosin(&mp->ctl_addr)->sin_addr,
130: sizeof (struct in_addr), AF_INET);
131: if (hp == (struct hostent *)0) {
132: rp->answer = MACHINE_UNKNOWN;
133: return;
134: }
135: ptr = find_request(mp);
136: if (ptr == (CTL_MSG *) 0) {
137: insert_table(mp, rp);
138: rp->answer = announce(mp, hp->h_name);
139: return;
140: }
141: if (mp->id_num > ptr->id_num) {
142: /*
143: * This is an explicit re-announce, so update the id_num
144: * field to avoid duplicates and re-announce the talk.
145: */
146: ptr->id_num = new_id();
147: rp->id_num = htonl(ptr->id_num);
148: rp->answer = announce(mp, hp->h_name);
149: } else {
150: /* a duplicated request, so ignore it */
151: rp->id_num = htonl(ptr->id_num);
152: rp->answer = SUCCESS;
153: }
154: }
155:
156: #include <utmp.h>
157:
158: /*
159: * Search utmp for the local user
160: */
161: find_user(name, tty)
162: char *name, *tty;
163: {
164: struct utmp ubuf;
165: int status;
166: FILE *fd;
167: struct stat statb;
168: char ftty[20];
169:
170: if ((fd = fopen("/etc/utmp", "r")) == NULL) {
171: perror("Can't open /etc/utmp");
172: return (FAILED);
173: }
174: #define SCMPN(a, b) strncmp(a, b, sizeof (a))
175: status = NOT_HERE;
176: (void) strcpy(ftty, "/dev/");
177: while (fread((char *) &ubuf, sizeof ubuf, 1, fd) == 1)
178: if (SCMPN(ubuf.ut_name, name) == 0) {
179: if (*tty == '\0') {
180: status = PERMISSION_DENIED;
181: /* no particular tty was requested */
182: (void) strcpy(ftty+5, ubuf.ut_line);
183: if (stat(ftty,&statb) == 0) {
184: if (!(statb.st_mode & 020))
185: continue;
186: (void) strcpy(tty, ubuf.ut_line);
187: status = SUCCESS;
188: break;
189: }
190: }
191: if (strcmp(ubuf.ut_line, tty) == 0) {
192: status = SUCCESS;
193: break;
194: }
195: }
196: fclose(fd);
197: return (status);
198: }
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