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34 static char sccsid[] = "@(#)table.c 8.1 (Berkeley) 6/4/93";
36 static const char rcsid[] =
41 * Routines to handle insertion, deletion, etc on the table
42 * of requests kept by the daemon. Nothing fancy here, linear
43 * search on a double-linked list. A time is kept with each
44 * entry so that overly old invitations can be eliminated.
46 * Consider this a mis-guided attempt at modularity
48 #include <sys/param.h>
50 #include <sys/socket.h>
51 #include <netinet/in.h>
52 #include <protocols/talkd.h>
61 #define MAX_ID 16000 /* << 2^15 so I don't have sign troubles */
63 #define NIL ((TABLE_ENTRY *)0)
65 static struct timespec ts;
67 typedef struct table_entry TABLE_ENTRY;
76 static void delete(TABLE_ENTRY *);
78 static TABLE_ENTRY *table = NIL;
81 * Look in the table for an invitation that matches the current
82 * request looking for an invitation
85 find_match(CTL_MSG *request)
87 TABLE_ENTRY *ptr, *next;
90 clock_gettime(CLOCK_MONOTONIC_FAST, &ts);
91 current_time = ts.tv_sec;
93 print_request("find_match", request);
94 for (ptr = table; ptr != NIL; ptr = next) {
96 if ((ptr->time - current_time) > MAX_LIFE) {
97 /* the entry is too old */
99 print_request("deleting expired entry",
105 print_request("", &ptr->request);
106 if (strcmp(request->l_name, ptr->request.r_name) == 0 &&
107 strcmp(request->r_name, ptr->request.l_name) == 0 &&
108 ptr->request.type == LEAVE_INVITE)
109 return (&ptr->request);
111 return ((CTL_MSG *)0);
115 * Look for an identical request, as opposed to a complimentary
116 * one as find_match does
119 find_request(CTL_MSG *request)
121 TABLE_ENTRY *ptr, *next;
124 clock_gettime(CLOCK_MONOTONIC_FAST, &ts);
125 current_time = ts.tv_sec;
127 * See if this is a repeated message, and check for
128 * out of date entries in the table while we are it.
131 print_request("find_request", request);
132 for (ptr = table; ptr != NIL; ptr = next) {
134 if ((ptr->time - current_time) > MAX_LIFE) {
135 /* the entry is too old */
137 print_request("deleting expired entry",
143 print_request("", &ptr->request);
144 if (strcmp(request->r_name, ptr->request.r_name) == 0 &&
145 strcmp(request->l_name, ptr->request.l_name) == 0 &&
146 request->type == ptr->request.type &&
147 request->pid == ptr->request.pid) {
148 /* update the time if we 'touch' it */
149 ptr->time = current_time;
150 return (&ptr->request);
153 return ((CTL_MSG *)0);
157 insert_table(CTL_MSG *request, CTL_RESPONSE *response)
162 clock_gettime(CLOCK_MONOTONIC_FAST, &ts);
163 current_time = ts.tv_sec;
164 request->id_num = new_id();
165 response->id_num = htonl(request->id_num);
166 /* insert a new entry into the top of the list */
167 ptr = (TABLE_ENTRY *)malloc(sizeof(TABLE_ENTRY));
169 syslog(LOG_ERR, "insert_table: Out of memory");
172 ptr->time = current_time;
173 ptr->request = *request;
175 if (ptr->next != NIL)
176 ptr->next->last = ptr;
182 * Generate a unique non-zero sequence number
187 static int current_id = 0;
189 current_id = (current_id + 1) % MAX_ID;
190 /* 0 is reserved, helps to pick up bugs */
197 * Delete the invitation with id 'id_num'
200 delete_invite(u_int32_t id_num)
205 syslog(LOG_DEBUG, "delete_invite(%d)", id_num);
206 for (ptr = table; ptr != NIL; ptr = ptr->next) {
207 if (ptr->request.id_num == id_num)
210 print_request("", &ptr->request);
220 * Classic delete from a double-linked list
223 delete(TABLE_ENTRY *ptr)
227 print_request("delete", &ptr->request);
230 else if (ptr->last != NIL)
231 ptr->last->next = ptr->next;
232 if (ptr->next != NIL)
233 ptr->next->last = ptr->last;