2 * Copyright (c) 1983, 1993
3 * The Regents of the University of California. All rights reserved.
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6 * modification, are permitted provided that the following conditions
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14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
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36 static char sccsid[] = "@(#)table.c 8.1 (Berkeley) 6/4/93";
38 static const char rcsid[] =
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 <netinet/in.h>
54 #include <protocols/talkd.h>
63 #define MAX_ID 16000 /* << 2^15 so I don't have sign troubles */
65 #define NIL ((TABLE_ENTRY *)0)
70 typedef struct table_entry TABLE_ENTRY;
79 static void delete(TABLE_ENTRY *);
81 TABLE_ENTRY *table = NIL;
84 * Look in the table for an invitation that matches the current
85 * request looking for an invitation
88 find_match(CTL_MSG *request)
93 gettimeofday(&tp, NULL);
94 current_time = tp.tv_sec;
96 print_request("find_match", request);
97 for (ptr = table; ptr != NIL; ptr = ptr->next) {
98 if ((ptr->time - current_time) > MAX_LIFE) {
99 /* the entry is too old */
101 print_request("deleting expired entry",
107 print_request("", &ptr->request);
108 if (strcmp(request->l_name, ptr->request.r_name) == 0 &&
109 strcmp(request->r_name, ptr->request.l_name) == 0 &&
110 ptr->request.type == LEAVE_INVITE)
111 return (&ptr->request);
113 return ((CTL_MSG *)0);
117 * Look for an identical request, as opposed to a complimentary
118 * one as find_match does
121 find_request(CTL_MSG *request)
126 gettimeofday(&tp, NULL);
127 current_time = tp.tv_sec;
129 * See if this is a repeated message, and check for
130 * out of date entries in the table while we are it.
133 print_request("find_request", request);
134 for (ptr = table; ptr != NIL; ptr = ptr->next) {
135 if ((ptr->time - current_time) > MAX_LIFE) {
136 /* the entry is too old */
138 print_request("deleting expired entry",
144 print_request("", &ptr->request);
145 if (strcmp(request->r_name, ptr->request.r_name) == 0 &&
146 strcmp(request->l_name, ptr->request.l_name) == 0 &&
147 request->type == ptr->request.type &&
148 request->pid == ptr->request.pid) {
149 /* update the time if we 'touch' it */
150 ptr->time = current_time;
151 return (&ptr->request);
154 return ((CTL_MSG *)0);
158 insert_table(CTL_MSG *request, CTL_RESPONSE *response)
163 gettimeofday(&tp, NULL);
164 current_time = tp.tv_sec;
165 request->id_num = new_id();
166 response->id_num = htonl(request->id_num);
167 /* insert a new entry into the top of the list */
168 ptr = (TABLE_ENTRY *)malloc(sizeof(TABLE_ENTRY));
170 syslog(LOG_ERR, "insert_table: Out of memory");
173 ptr->time = current_time;
174 ptr->request = *request;
176 if (ptr->next != NIL)
177 ptr->next->last = ptr;
183 * Generate a unique non-zero sequence number
188 static int current_id = 0;
190 current_id = (current_id + 1) % MAX_ID;
191 /* 0 is reserved, helps to pick up bugs */
198 * Delete the invitation with id 'id_num'
201 delete_invite(u_int32_t id_num)
207 syslog(LOG_DEBUG, "delete_invite(%d)", id_num);
208 for (ptr = table; ptr != NIL; ptr = ptr->next) {
209 if (ptr->request.id_num == id_num)
212 print_request("", &ptr->request);
222 * Classic delete from a double-linked list
225 delete(TABLE_ENTRY *ptr)
229 print_request("delete", &ptr->request);
232 else if (ptr->last != NIL)
233 ptr->last->next = ptr->next;
234 if (ptr->next != NIL)
235 ptr->next->last = ptr->last;