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29 * @(#)table.c 8.1 (Berkeley) 6/4/93
30 * $FreeBSD: src/libexec/talkd/table.c,v 1.7 1999/08/28 00:10:17 peter Exp $
34 * Routines to handle insertion, deletion, etc on the table
35 * of requests kept by the daemon. Nothing fancy here, linear
36 * search on a double-linked list. A time is kept with each
37 * entry so that overly old invitations can be eliminated.
39 * Consider this a mis-guided attempt at modularity
41 #include <sys/param.h>
43 #include <sys/socket.h>
44 #include <protocols/talkd.h>
53 #define MAX_ID 16000 /* << 2^15 so I don't have sign troubles */
58 typedef struct table_entry TABLE_ENTRY;
67 static void delete(TABLE_ENTRY *);
69 TABLE_ENTRY *table = NULL;
72 * Look in the table for an invitation that matches the current
73 * request looking for an invitation
76 find_match(CTL_MSG *request)
81 gettimeofday(&tp, NULL);
82 current_time = tp.tv_sec;
84 print_request("find_match", request);
85 for (ptr = table; ptr != NULL; ptr = ptr->next) {
86 if ((ptr->time - current_time) > MAX_LIFE) {
87 /* the entry is too old */
89 print_request("deleting expired entry",
95 print_request("", &ptr->request);
96 if (strcmp(request->l_name, ptr->request.r_name) == 0 &&
97 strcmp(request->r_name, ptr->request.l_name) == 0 &&
98 ptr->request.type == LEAVE_INVITE)
99 return (&ptr->request);
105 * Look for an identical request, as opposed to a complimentary
106 * one as find_match does
109 find_request(CTL_MSG *request)
114 gettimeofday(&tp, NULL);
115 current_time = tp.tv_sec;
117 * See if this is a repeated message, and check for
118 * out of date entries in the table while we are it.
121 print_request("find_request", request);
122 for (ptr = table; ptr != NULL; ptr = ptr->next) {
123 if ((ptr->time - current_time) > MAX_LIFE) {
124 /* the entry is too old */
126 print_request("deleting expired entry",
132 print_request("", &ptr->request);
133 if (strcmp(request->r_name, ptr->request.r_name) == 0 &&
134 strcmp(request->l_name, ptr->request.l_name) == 0 &&
135 request->type == ptr->request.type &&
136 request->pid == ptr->request.pid) {
137 /* update the time if we 'touch' it */
138 ptr->time = current_time;
139 return (&ptr->request);
146 insert_table(CTL_MSG *request, CTL_RESPONSE *response)
151 gettimeofday(&tp, NULL);
152 current_time = tp.tv_sec;
153 request->id_num = new_id();
154 response->id_num = htonl(request->id_num);
155 /* insert a new entry into the top of the list */
156 ptr = (TABLE_ENTRY *)malloc(sizeof(TABLE_ENTRY));
158 syslog(LOG_ERR, "insert_table: Out of memory");
161 ptr->time = current_time;
162 ptr->request = *request;
164 if (ptr->next != NULL)
165 ptr->next->last = ptr;
171 * Generate a unique non-zero sequence number
176 static int current_id = 0;
178 current_id = (current_id + 1) % MAX_ID;
179 /* 0 is reserved, helps to pick up bugs */
186 * Delete the invitation with id 'id_num'
189 delete_invite(unsigned int id_num)
195 syslog(LOG_DEBUG, "delete_invite(%d)", id_num);
196 for (ptr = table; ptr != NULL; ptr = ptr->next) {
197 if (ptr->request.id_num == id_num)
200 print_request("", &ptr->request);
210 * Classic delete from a double-linked list
213 delete(TABLE_ENTRY *ptr)
217 print_request("delete", &ptr->request);
220 else if (ptr->last != NULL)
221 ptr->last->next = ptr->next;
222 if (ptr->next != NULL)
223 ptr->next->last = ptr->last;