2 * Copyright (c) 1983, 1993
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32 static char sccsid[] = "@(#)table.c 8.1 (Berkeley) 6/4/93";
34 static const char rcsid[] =
39 * Routines to handle insertion, deletion, etc on the table
40 * of requests kept by the daemon. Nothing fancy here, linear
41 * search on a double-linked list. A time is kept with each
42 * entry so that overly old invitations can be eliminated.
44 * Consider this a mis-guided attempt at modularity
46 #include <sys/param.h>
48 #include <sys/socket.h>
49 #include <netinet/in.h>
50 #include <protocols/talkd.h>
59 #define MAX_ID 16000 /* << 2^15 so I don't have sign troubles */
61 #define NIL ((TABLE_ENTRY *)0)
63 static struct timeval tp;
65 typedef struct table_entry TABLE_ENTRY;
74 static void delete(TABLE_ENTRY *);
76 static TABLE_ENTRY *table = NIL;
79 * Look in the table for an invitation that matches the current
80 * request looking for an invitation
83 find_match(CTL_MSG *request)
88 gettimeofday(&tp, NULL);
89 current_time = tp.tv_sec;
91 print_request("find_match", request);
92 for (ptr = table; ptr != NIL; ptr = ptr->next) {
93 if ((ptr->time - current_time) > MAX_LIFE) {
94 /* the entry is too old */
96 print_request("deleting expired entry",
102 print_request("", &ptr->request);
103 if (strcmp(request->l_name, ptr->request.r_name) == 0 &&
104 strcmp(request->r_name, ptr->request.l_name) == 0 &&
105 ptr->request.type == LEAVE_INVITE)
106 return (&ptr->request);
108 return ((CTL_MSG *)0);
112 * Look for an identical request, as opposed to a complimentary
113 * one as find_match does
116 find_request(CTL_MSG *request)
121 gettimeofday(&tp, NULL);
122 current_time = tp.tv_sec;
124 * See if this is a repeated message, and check for
125 * out of date entries in the table while we are it.
128 print_request("find_request", request);
129 for (ptr = table; ptr != NIL; ptr = ptr->next) {
130 if ((ptr->time - current_time) > MAX_LIFE) {
131 /* the entry is too old */
133 print_request("deleting expired entry",
139 print_request("", &ptr->request);
140 if (strcmp(request->r_name, ptr->request.r_name) == 0 &&
141 strcmp(request->l_name, ptr->request.l_name) == 0 &&
142 request->type == ptr->request.type &&
143 request->pid == ptr->request.pid) {
144 /* update the time if we 'touch' it */
145 ptr->time = current_time;
146 return (&ptr->request);
149 return ((CTL_MSG *)0);
153 insert_table(CTL_MSG *request, CTL_RESPONSE *response)
158 gettimeofday(&tp, NULL);
159 current_time = tp.tv_sec;
160 request->id_num = new_id();
161 response->id_num = htonl(request->id_num);
162 /* insert a new entry into the top of the list */
163 ptr = (TABLE_ENTRY *)malloc(sizeof(TABLE_ENTRY));
165 syslog(LOG_ERR, "insert_table: Out of memory");
168 ptr->time = current_time;
169 ptr->request = *request;
171 if (ptr->next != NIL)
172 ptr->next->last = ptr;
178 * Generate a unique non-zero sequence number
183 static int current_id = 0;
185 current_id = (current_id + 1) % MAX_ID;
186 /* 0 is reserved, helps to pick up bugs */
193 * Delete the invitation with id 'id_num'
196 delete_invite(u_int32_t id_num)
201 syslog(LOG_DEBUG, "delete_invite(%d)", id_num);
202 for (ptr = table; ptr != NIL; ptr = ptr->next) {
203 if (ptr->request.id_num == id_num)
206 print_request("", &ptr->request);
216 * Classic delete from a double-linked list
219 delete(TABLE_ENTRY *ptr)
223 print_request("delete", &ptr->request);
226 else if (ptr->last != NIL)
227 ptr->last->next = ptr->next;
228 if (ptr->next != NIL)
229 ptr->next->last = ptr->last;