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33 * @(#)table.c 8.1 (Berkeley) 6/4/93
34 * $FreeBSD: src/libexec/talkd/table.c,v 1.7 1999/08/28 00:10:17 peter Exp $
35 * $DragonFly: src/libexec/talkd/table.c,v 1.3 2003/11/14 03:54:31 dillon Exp $
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 <protocols/talkd.h>
56 #define MAX_ID 16000 /* << 2^15 so I don't have sign troubles */
58 #define NIL ((TABLE_ENTRY *)0)
64 typedef struct table_entry TABLE_ENTRY;
73 TABLE_ENTRY *table = NIL;
75 void delete (TABLE_ENTRY *);
76 CTL_MSG *find_request();
77 CTL_MSG *find_match();
79 void print_request (char *, CTL_MSG *);
82 * Look in the table for an invitation that matches the current
83 * request looking for an invitation
87 register CTL_MSG *request;
89 register TABLE_ENTRY *ptr;
92 gettimeofday(&tp, &txp);
93 current_time = tp.tv_sec;
95 print_request("find_match", request);
96 for (ptr = table; ptr != NIL; ptr = ptr->next) {
97 if ((ptr->time - current_time) > MAX_LIFE) {
98 /* the entry is too old */
100 print_request("deleting expired entry",
106 print_request("", &ptr->request);
107 if (strcmp(request->l_name, ptr->request.r_name) == 0 &&
108 strcmp(request->r_name, ptr->request.l_name) == 0 &&
109 ptr->request.type == LEAVE_INVITE)
110 return (&ptr->request);
112 return ((CTL_MSG *)0);
116 * Look for an identical request, as opposed to a complimentary
117 * one as find_match does
120 find_request(request)
121 register CTL_MSG *request;
123 register TABLE_ENTRY *ptr;
126 gettimeofday(&tp, &txp);
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130 * out of date entries in the table while we are it.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(request, response)
160 CTL_RESPONSE *response;
162 register TABLE_ENTRY *ptr;
165 gettimeofday(&tp, &txp);
166 current_time = tp.tv_sec;
167 request->id_num = new_id();
168 response->id_num = htonl(request->id_num);
169 /* insert a new entry into the top of the list */
170 ptr = (TABLE_ENTRY *)malloc(sizeof(TABLE_ENTRY));
172 syslog(LOG_ERR, "insert_table: Out of memory");
175 ptr->time = current_time;
176 ptr->request = *request;
178 if (ptr->next != NIL)
179 ptr->next->last = ptr;
185 * Generate a unique non-zero sequence number
190 static int current_id = 0;
192 current_id = (current_id + 1) % MAX_ID;
193 /* 0 is reserved, helps to pick up bugs */
200 * Delete the invitation with id 'id_num'
203 delete_invite(id_num)
206 register TABLE_ENTRY *ptr;
210 syslog(LOG_DEBUG, "delete_invite(%d)", id_num);
211 for (ptr = table; ptr != NIL; ptr = ptr->next) {
212 if (ptr->request.id_num == id_num)
215 print_request("", &ptr->request);
225 * Classic delete from a double-linked list
229 register TABLE_ENTRY *ptr;
233 print_request("delete", &ptr->request);
236 else if (ptr->last != NIL)
237 ptr->last->next = ptr->next;
238 if (ptr->next != NIL)
239 ptr->next->last = ptr->last;