--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/usr/src/cmd/cmd-inet/usr.sbin/in.talkd/table.c	Tue Jun 02 18:56:50 2009 +0900
@@ -0,0 +1,285 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License, Version 1.0 only
+ * (the "License").  You may not use this file except in compliance
+ * with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ *
+ * Copyright 2002 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+/*
+ * Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T
+ * All Rights Reserved.
+ */
+
+/*
+ * University Copyright- Copyright (c) 1982, 1986, 1988
+ * The Regents of the University of California.
+ * All Rights Reserved.
+ *
+ * University Acknowledgment- Portions of this document are derived from
+ * software developed by the University of California, Berkeley, and its
+ * contributors.
+ */
+
+#pragma ident	"@(#)table.c	1.8	05/06/12 SMI"
+
+
+/*
+ * Routines to handle insertion, deletion, etc on the table
+ * of requests kept by the daemon. Nothing fancy here, linear
+ * search on a double-linked list. A time is kept with each
+ * entry so that overly old invitations can be eliminated.
+ *
+ * Consider this a mis-guided attempt at modularity
+ */
+
+#include <sys/time.h>
+#include <string.h>
+#include <stdio.h>
+#include <malloc.h>
+#include "talkd_impl.h"
+
+#define	MAX_ID 16000 /* << 2^15 so I don't have sign troubles */
+
+typedef struct table_entry TABLE_ENTRY;
+
+struct table_entry {
+    CTL_MSG request;
+    long time;
+    TABLE_ENTRY *next;
+    TABLE_ENTRY *last;
+};
+
+static struct timeval tp;
+static TABLE_ENTRY *table = NULL;
+
+static void delete(TABLE_ENTRY *ptr);
+
+/*
+ * Look in the table for an invitation that matches the current
+ * request looking for an invitation.
+ */
+
+CTL_MSG *
+find_match(CTL_MSG *request)
+{
+	TABLE_ENTRY *ptr;
+	TABLE_ENTRY *prevp;
+	long current_time;
+
+	(void) gettimeofday(&tp, NULL);
+	current_time = tp.tv_sec;
+
+	ptr = table;
+
+	if (debug) {
+		(void) printf("Entering Look-Up with : \n");
+		print_request(request);
+	}
+
+	while (ptr != NULL) {
+
+		if ((ptr->time - current_time) > MAX_LIFE) {
+		/* the entry is too old */
+			if (debug) {
+				(void) printf("Deleting expired entry : \n");
+				print_request(&ptr->request);
+			}
+			prevp = ptr;
+			ptr = ptr->next;
+			delete(prevp);
+			continue;
+		}
+
+		if (debug)
+			print_request(&ptr->request);
+
+		if (strcmp(request->l_name, ptr->request.r_name) == 0 &&
+		    strcmp(request->r_name, ptr->request.l_name) == 0 &&
+		    ptr->request.type == LEAVE_INVITE) {
+			return (&ptr->request);
+		}
+
+		ptr = ptr->next;
+	}
+
+	return (NULL);
+}
+
+/*
+ * Look for an identical request, as opposed to a complimentary
+ * one as find_match does.
+ */
+
+CTL_MSG *
+find_request(CTL_MSG *request)
+{
+	TABLE_ENTRY *ptr;
+	TABLE_ENTRY *prevp;
+	long current_time;
+
+	(void) gettimeofday(&tp, NULL);
+	current_time = tp.tv_sec;
+
+	/*
+	 * See if this is a repeated message, and check for
+	 * out of date entries in the table while we are it.
+	 */
+
+	ptr = table;
+
+	if (debug) {
+		(void) printf("Entering find_request with : \n");
+		print_request(request);
+	}
+
+	while (ptr != NULL) {
+
+		if ((ptr->time - current_time) > MAX_LIFE) {
+			/* the entry is too old */
+			if (debug) {
+				(void) printf("Deleting expired entry : \n");
+				print_request(&ptr->request);
+			}
+			prevp = ptr;
+			ptr = ptr->next;
+			delete(prevp);
+			continue;
+		}
+
+		if (debug)
+			print_request(&ptr->request);
+
+		if (strcmp(request->r_name, ptr->request.r_name) == 0 &&
+		    strcmp(request->l_name, ptr->request.l_name) == 0 &&
+		    request->type == ptr->request.type &&
+		    request->pid == ptr->request.pid) {
+
+			/* update the time if we 'touch' it */
+			ptr->time = current_time;
+			return (&ptr->request);
+		}
+
+		ptr = ptr->next;
+	}
+
+	return (NULL);
+}
+
+void
+insert_table(CTL_MSG *request, CTL_RESPONSE *response)
+{
+	TABLE_ENTRY *ptr;
+	long current_time;
+
+	(void) gettimeofday(&tp, NULL);
+	current_time = tp.tv_sec;
+
+	response->id_num = request->id_num = new_id();
+
+	/*
+	 * Insert a new entry into the top of the list.
+	 */
+	ptr = (TABLE_ENTRY *) malloc(sizeof (TABLE_ENTRY));
+
+	if (ptr == NULL) {
+		print_error("malloc in insert_table");
+	}
+
+	ptr->time = current_time;
+	ptr->request = *request;
+
+	ptr->next = table;
+	if (ptr->next != NULL) {
+		ptr->next->last = ptr;
+	}
+	ptr->last = NULL;
+	table = ptr;
+}
+
+/*
+ * Generate a unique non-zero sequence number.
+ */
+
+int
+new_id(void)
+{
+	static int current_id = 0;
+
+	current_id = (current_id + 1) % MAX_ID;
+
+	/* 0 is reserved, helps to pick up bugs */
+	if (current_id == 0)
+		current_id = 1;
+
+	return (current_id);
+}
+
+/*
+ * Delete the invitation with id 'id_num'.
+ */
+
+int
+delete_invite(int id_num)
+{
+	TABLE_ENTRY *ptr;
+
+	ptr = table;
+
+	if (debug)
+		(void) printf("Entering delete_invite with %d\n", id_num);
+
+	while (ptr != NULL && ptr->request.id_num != id_num) {
+		if (debug)
+			print_request(&ptr->request);
+			ptr = ptr->next;
+	}
+
+	if (ptr != NULL) {
+		delete(ptr);
+		return (SUCCESS);
+	}
+
+	return (NOT_HERE);
+}
+
+/*
+ * Classic delete from a double-linked list.
+ */
+
+static void
+delete(TABLE_ENTRY *ptr)
+{
+	if (debug) {
+		(void) printf("Deleting : ");
+		print_request(&ptr->request);
+	}
+	if (table == ptr) {
+		table = ptr->next;
+	} else if (ptr->last != NULL) {
+		ptr->last->next = ptr->next;
+	}
+
+	if (ptr->next != NULL) {
+		ptr->next->last = ptr->last;
+	}
+
+	free(ptr);
+}