2 * Copyright (c) 1983, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 static char sccsid[] = "@(#)table.c 8.1 (Berkeley) 6/4/93";
38 static const char rcsid[] =
39 "$FreeBSD: src/libexec/talkd/table.c,v 1.7 1999/08/28 00:10:17 peter Exp $";
43 * Routines to handle insertion, deletion, etc on the table
44 * of requests kept by the daemon. Nothing fancy here, linear
45 * search on a double-linked list. A time is kept with each
46 * entry so that overly old invitations can be eliminated.
48 * Consider this a mis-guided attempt at modularity
50 #include <sys/param.h>
52 #include <sys/socket.h>
53 #include <protocols/talkd.h>
60 #define MAX_ID 16000 /* << 2^15 so I don't have sign troubles */
62 #define NIL ((TABLE_ENTRY *)0)
68 typedef struct table_entry TABLE_ENTRY;
77 TABLE_ENTRY *table = NIL;
79 void delete __P((TABLE_ENTRY *));
80 CTL_MSG *find_request();
81 CTL_MSG *find_match();
82 int new_id __P((void));
83 void print_request __P((char *, CTL_MSG *));
86 * Look in the table for an invitation that matches the current
87 * request looking for an invitation
91 register CTL_MSG *request;
93 register TABLE_ENTRY *ptr;
96 gettimeofday(&tp, &txp);
97 current_time = tp.tv_sec;
99 print_request("find_match", request);
100 for (ptr = table; ptr != NIL; ptr = ptr->next) {
101 if ((ptr->time - current_time) > MAX_LIFE) {
102 /* the entry is too old */
104 print_request("deleting expired entry",
110 print_request("", &ptr->request);
111 if (strcmp(request->l_name, ptr->request.r_name) == 0 &&
112 strcmp(request->r_name, ptr->request.l_name) == 0 &&
113 ptr->request.type == LEAVE_INVITE)
114 return (&ptr->request);
116 return ((CTL_MSG *)0);
120 * Look for an identical request, as opposed to a complimentary
121 * one as find_match does
124 find_request(request)
125 register CTL_MSG *request;
127 register TABLE_ENTRY *ptr;
130 gettimeofday(&tp, &txp);
131 current_time = tp.tv_sec;
133 * See if this is a repeated message, and check for
134 * out of date entries in the table while we are it.
137 print_request("find_request", request);
138 for (ptr = table; ptr != NIL; ptr = ptr->next) {
139 if ((ptr->time - current_time) > MAX_LIFE) {
140 /* the entry is too old */
142 print_request("deleting expired entry",
148 print_request("", &ptr->request);
149 if (strcmp(request->r_name, ptr->request.r_name) == 0 &&
150 strcmp(request->l_name, ptr->request.l_name) == 0 &&
151 request->type == ptr->request.type &&
152 request->pid == ptr->request.pid) {
153 /* update the time if we 'touch' it */
154 ptr->time = current_time;
155 return (&ptr->request);
158 return ((CTL_MSG *)0);
162 insert_table(request, response)
164 CTL_RESPONSE *response;
166 register TABLE_ENTRY *ptr;
169 gettimeofday(&tp, &txp);
170 current_time = tp.tv_sec;
171 request->id_num = new_id();
172 response->id_num = htonl(request->id_num);
173 /* insert a new entry into the top of the list */
174 ptr = (TABLE_ENTRY *)malloc(sizeof(TABLE_ENTRY));
176 syslog(LOG_ERR, "insert_table: Out of memory");
179 ptr->time = current_time;
180 ptr->request = *request;
182 if (ptr->next != NIL)
183 ptr->next->last = ptr;
189 * Generate a unique non-zero sequence number
194 static int current_id = 0;
196 current_id = (current_id + 1) % MAX_ID;
197 /* 0 is reserved, helps to pick up bugs */
204 * Delete the invitation with id 'id_num'
207 delete_invite(id_num)
210 register TABLE_ENTRY *ptr;
214 syslog(LOG_DEBUG, "delete_invite(%d)", id_num);
215 for (ptr = table; ptr != NIL; ptr = ptr->next) {
216 if (ptr->request.id_num == id_num)
219 print_request("", &ptr->request);
229 * Classic delete from a double-linked list
233 register TABLE_ENTRY *ptr;
237 print_request("delete", &ptr->request);
240 else if (ptr->last != NIL)
241 ptr->last->next = ptr->next;
242 if (ptr->next != NIL)
243 ptr->next->last = ptr->last;