table.c revision 211056
1272343Sngie/* 2272343Sngie * Copyright (c) 1983, 1993 3272343Sngie * The Regents of the University of California. All rights reserved. 4272343Sngie * 5272343Sngie * Redistribution and use in source and binary forms, with or without 6272343Sngie * modification, are permitted provided that the following conditions 7272343Sngie * are met: 8272343Sngie * 1. Redistributions of source code must retain the above copyright 9272343Sngie * notice, this list of conditions and the following disclaimer. 10272343Sngie * 2. Redistributions in binary form must reproduce the above copyright 11272343Sngie * notice, this list of conditions and the following disclaimer in the 12272343Sngie * documentation and/or other materials provided with the distribution. 13272343Sngie * 3. All advertising materials mentioning features or use of this software 14272343Sngie * must display the following acknowledgement: 15272343Sngie * This product includes software developed by the University of 16272343Sngie * California, Berkeley and its contributors. 17272343Sngie * 4. Neither the name of the University nor the names of its contributors 18272343Sngie * may be used to endorse or promote products derived from this software 19272343Sngie * without specific prior written permission. 20272343Sngie * 21272343Sngie * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22272343Sngie * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23272343Sngie * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24272343Sngie * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25272343Sngie * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26272343Sngie * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27272343Sngie * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28272343Sngie * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29272343Sngie * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30272343Sngie * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31272343Sngie * SUCH DAMAGE. 32272343Sngie */ 33272343Sngie 34272343Sngie#ifndef lint 35272343Sngie#if 0 36272343Sngiestatic char sccsid[] = "@(#)table.c 8.1 (Berkeley) 6/4/93"; 37272343Sngie#endif 38272343Sngiestatic const char rcsid[] = 39272343Sngie "$FreeBSD: head/libexec/talkd/table.c 211056 2010-08-08 02:45:48Z ed $"; 40272343Sngie#endif /* not lint */ 41272343Sngie 42272343Sngie/* 43272343Sngie * Routines to handle insertion, deletion, etc on the table 44272343Sngie * of requests kept by the daemon. Nothing fancy here, linear 45272343Sngie * search on a double-linked list. A time is kept with each 46272343Sngie * entry so that overly old invitations can be eliminated. 47272343Sngie * 48272343Sngie * Consider this a mis-guided attempt at modularity 49272343Sngie */ 50272343Sngie#include <sys/param.h> 51272343Sngie#include <sys/time.h> 52272343Sngie#include <sys/socket.h> 53272343Sngie#include <netinet/in.h> 54272343Sngie#include <protocols/talkd.h> 55272343Sngie#include <stdio.h> 56272343Sngie#include <stdlib.h> 57272343Sngie#include <string.h> 58272343Sngie#include <syslog.h> 59272343Sngie#include <unistd.h> 60272343Sngie 61272343Sngie#include "extern.h" 62272343Sngie 63272343Sngie#define MAX_ID 16000 /* << 2^15 so I don't have sign troubles */ 64272343Sngie 65272343Sngie#define NIL ((TABLE_ENTRY *)0) 66272343Sngie 67272343Sngieextern int debug; 68272343Sngiestruct timeval tp; 69272343Sngie 70272343Sngietypedef struct table_entry TABLE_ENTRY; 71272343Sngie 72272343Sngiestruct table_entry { 73272343Sngie CTL_MSG request; 74272343Sngie long time; 75272343Sngie TABLE_ENTRY *next; 76272343Sngie TABLE_ENTRY *last; 77272343Sngie}; 78272343Sngie 79272343Sngiestatic void delete(TABLE_ENTRY *); 80272343Sngie 81272343SngieTABLE_ENTRY *table = NIL; 82272343Sngie 83272343Sngie/* 84272343Sngie * Look in the table for an invitation that matches the current 85272343Sngie * request looking for an invitation 86272343Sngie */ 87272343SngieCTL_MSG * 88272343Sngiefind_match(CTL_MSG *request) 89272343Sngie{ 90272343Sngie TABLE_ENTRY *ptr; 91272343Sngie time_t current_time; 92272343Sngie 93272343Sngie gettimeofday(&tp, NULL); 94272343Sngie current_time = tp.tv_sec; 95272343Sngie if (debug) 96272343Sngie print_request("find_match", request); 97272343Sngie for (ptr = table; ptr != NIL; ptr = ptr->next) { 98272343Sngie if ((ptr->time - current_time) > MAX_LIFE) { 99272343Sngie /* the entry is too old */ 100272343Sngie if (debug) 101272343Sngie print_request("deleting expired entry", 102272343Sngie &ptr->request); 103272343Sngie delete(ptr); 104272343Sngie continue; 105272343Sngie } 106272343Sngie if (debug) 107272343Sngie print_request("", &ptr->request); 108272343Sngie if (strcmp(request->l_name, ptr->request.r_name) == 0 && 109272343Sngie strcmp(request->r_name, ptr->request.l_name) == 0 && 110272343Sngie ptr->request.type == LEAVE_INVITE) 111272343Sngie return (&ptr->request); 112272343Sngie } 113272343Sngie return ((CTL_MSG *)0); 114272343Sngie} 115272343Sngie 116272343Sngie/* 117272343Sngie * Look for an identical request, as opposed to a complimentary 118272343Sngie * one as find_match does 119272343Sngie */ 120272343SngieCTL_MSG * 121272343Sngiefind_request(CTL_MSG *request) 122272343Sngie{ 123272343Sngie TABLE_ENTRY *ptr; 124272343Sngie time_t current_time; 125272343Sngie 126272343Sngie gettimeofday(&tp, NULL); 127272343Sngie current_time = tp.tv_sec; 128272343Sngie /* 129272343Sngie * See if this is a repeated message, and check for 130272343Sngie * out of date entries in the table while we are it. 131272343Sngie */ 132272343Sngie if (debug) 133272343Sngie print_request("find_request", request); 134272343Sngie for (ptr = table; ptr != NIL; ptr = ptr->next) { 135272343Sngie if ((ptr->time - current_time) > MAX_LIFE) { 136272343Sngie /* the entry is too old */ 137272343Sngie if (debug) 138272343Sngie print_request("deleting expired entry", 139272343Sngie &ptr->request); 140272343Sngie delete(ptr); 141272343Sngie continue; 142272343Sngie } 143272343Sngie if (debug) 144272343Sngie print_request("", &ptr->request); 145272343Sngie if (strcmp(request->r_name, ptr->request.r_name) == 0 && 146272343Sngie strcmp(request->l_name, ptr->request.l_name) == 0 && 147272343Sngie request->type == ptr->request.type && 148272343Sngie request->pid == ptr->request.pid) { 149272343Sngie /* update the time if we 'touch' it */ 150272343Sngie ptr->time = current_time; 151272343Sngie return (&ptr->request); 152272343Sngie } 153272343Sngie } 154272343Sngie return ((CTL_MSG *)0); 155272343Sngie} 156272343Sngie 157272343Sngievoid 158272343Sngieinsert_table(CTL_MSG *request, CTL_RESPONSE *response) 159272343Sngie{ 160272343Sngie TABLE_ENTRY *ptr; 161272343Sngie time_t current_time; 162272343Sngie 163272343Sngie gettimeofday(&tp, NULL); 164272343Sngie current_time = tp.tv_sec; 165272343Sngie request->id_num = new_id(); 166272343Sngie response->id_num = htonl(request->id_num); 167272343Sngie /* insert a new entry into the top of the list */ 168272343Sngie ptr = (TABLE_ENTRY *)malloc(sizeof(TABLE_ENTRY)); 169272343Sngie if (ptr == NIL) { 170272343Sngie syslog(LOG_ERR, "insert_table: Out of memory"); 171272343Sngie _exit(1); 172272343Sngie } 173272343Sngie ptr->time = current_time; 174272343Sngie ptr->request = *request; 175272343Sngie ptr->next = table; 176272343Sngie if (ptr->next != NIL) 177272343Sngie ptr->next->last = ptr; 178272343Sngie ptr->last = NIL; 179272343Sngie table = ptr; 180272343Sngie} 181272343Sngie 182272343Sngie/* 183272343Sngie * Generate a unique non-zero sequence number 184272343Sngie */ 185272343Sngieint 186272343Sngienew_id(void) 187272343Sngie{ 188272343Sngie static int current_id = 0; 189272343Sngie 190272343Sngie current_id = (current_id + 1) % MAX_ID; 191272343Sngie /* 0 is reserved, helps to pick up bugs */ 192272343Sngie if (current_id == 0) 193272343Sngie current_id = 1; 194272343Sngie return (current_id); 195} 196 197/* 198 * Delete the invitation with id 'id_num' 199 */ 200int 201delete_invite(u_int32_t id_num) 202{ 203 TABLE_ENTRY *ptr; 204 205 ptr = table; 206 if (debug) 207 syslog(LOG_DEBUG, "delete_invite(%d)", id_num); 208 for (ptr = table; ptr != NIL; ptr = ptr->next) { 209 if (ptr->request.id_num == id_num) 210 break; 211 if (debug) 212 print_request("", &ptr->request); 213 } 214 if (ptr != NIL) { 215 delete(ptr); 216 return (SUCCESS); 217 } 218 return (NOT_HERE); 219} 220 221/* 222 * Classic delete from a double-linked list 223 */ 224static void 225delete(TABLE_ENTRY *ptr) 226{ 227 228 if (debug) 229 print_request("delete", &ptr->request); 230 if (table == ptr) 231 table = ptr->next; 232 else if (ptr->last != NIL) 233 ptr->last->next = ptr->next; 234 if (ptr->next != NIL) 235 ptr->next->last = ptr->last; 236 free((char *)ptr); 237} 238