1 /* $NetBSD: table.c,v 1.12 2025/12/18 08:26:59 nia Exp $ */ 2 3 /* 4 * Copyright (c) 1983, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 #ifndef lint 34 #if 0 35 static char sccsid[] = "@(#)table.c 8.1 (Berkeley) 6/4/93"; 36 #else 37 __RCSID("$NetBSD: table.c,v 1.12 2025/12/18 08:26:59 nia Exp $"); 38 #endif 39 #endif /* not lint */ 40 41 /* 42 * Routines to handle insertion, deletion, etc on the table 43 * of requests kept by the daemon. Nothing fancy here, linear 44 * search on a double-linked list. A time is kept with each 45 * entry so that overly old invitations can be eliminated. 46 * 47 * Consider this a mis-guided attempt at modularity 48 */ 49 #include <sys/param.h> 50 #include <sys/time.h> 51 #include <sys/socket.h> 52 #include <protocols/talkd.h> 53 #include <inttypes.h> 54 #include <syslog.h> 55 #include <endian.h> 56 #include <unistd.h> 57 #include <stdio.h> 58 #include <stdlib.h> 59 #include <string.h> 60 #include "extern.h" 61 62 #define MAX_ID 16000 /* << 2^15 so I don't have sign troubles */ 63 64 #define NIL ((TABLE_ENTRY *)0) 65 66 struct timeval tp; 67 68 typedef struct table_entry TABLE_ENTRY; 69 70 struct table_entry { 71 CTL_MSG request; 72 time_t time; 73 TABLE_ENTRY *next; 74 TABLE_ENTRY *last; 75 }; 76 77 TABLE_ENTRY *table = NIL; 78 79 static void delete(TABLE_ENTRY *); 80 81 /* 82 * Look in the table for an invitation that matches the current 83 * request looking for an invitation 84 */ 85 CTL_MSG * 86 find_match(CTL_MSG *request) 87 { 88 TABLE_ENTRY *ptr; 89 time_t current_time; 90 91 gettimeofday(&tp, NULL); 92 current_time = tp.tv_sec; 93 if (debug) 94 print_request("find_match", request); 95 for (ptr = table; ptr != NIL; ptr = ptr->next) { 96 if ((ptr->time - current_time) > MAX_LIFE) { 97 /* the entry is too old */ 98 if (debug) 99 print_request("deleting expired entry", 100 &ptr->request); 101 delete(ptr); 102 continue; 103 } 104 if (debug) 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); 110 } 111 return ((CTL_MSG *)0); 112 } 113 114 /* 115 * Look for an identical request, as opposed to a complimentary 116 * one as find_match does 117 */ 118 CTL_MSG * 119 find_request(CTL_MSG *request) 120 { 121 TABLE_ENTRY *ptr; 122 time_t current_time; 123 124 gettimeofday(&tp, NULL); 125 current_time = tp.tv_sec; 126 /* 127 * See if this is a repeated message, and check for 128 * out of date entries in the table while we are it. 129 */ 130 if (debug) 131 print_request("find_request", request); 132 for (ptr = table; ptr != NIL; ptr = ptr->next) { 133 if ((ptr->time - current_time) > MAX_LIFE) { 134 /* the entry is too old */ 135 if (debug) 136 print_request("deleting expired entry", 137 &ptr->request); 138 delete(ptr); 139 continue; 140 } 141 if (debug) 142 print_request("", &ptr->request); 143 if (strcmp(request->r_name, ptr->request.r_name) == 0 && 144 strcmp(request->l_name, ptr->request.l_name) == 0 && 145 request->type == ptr->request.type && 146 request->pid == ptr->request.pid) { 147 /* update the time if we 'touch' it */ 148 ptr->time = current_time; 149 return (&ptr->request); 150 } 151 } 152 return ((CTL_MSG *)0); 153 } 154 155 void 156 insert_table(CTL_MSG *request, CTL_RESPONSE *response) 157 { 158 TABLE_ENTRY *ptr; 159 time_t current_time; 160 161 gettimeofday(&tp, NULL); 162 current_time = tp.tv_sec; 163 request->id_num = new_id(); 164 response->id_num = htonl(request->id_num); 165 /* insert a new entry into the top of the list */ 166 ptr = (TABLE_ENTRY *)malloc(sizeof(TABLE_ENTRY)); 167 if (ptr == NIL) { 168 syslog(LOG_ERR, "insert_table: Out of memory"); 169 _exit(1); 170 } 171 ptr->time = current_time; 172 ptr->request = *request; 173 ptr->next = table; 174 if (ptr->next != NIL) 175 ptr->next->last = ptr; 176 ptr->last = NIL; 177 table = ptr; 178 } 179 180 /* 181 * Generate a unique non-zero sequence number 182 */ 183 uint32_t 184 new_id(void) 185 { 186 static uint32_t current_id = 0; 187 188 current_id = (current_id + 1) % MAX_ID; 189 /* 0 is reserved, helps to pick up bugs */ 190 if (current_id == 0) 191 current_id = 1; 192 return (current_id); 193 } 194 195 /* 196 * Delete the invitation with id 'id_num' 197 */ 198 u_char 199 delete_invite(uint32_t id_num) 200 { 201 TABLE_ENTRY *ptr; 202 203 if (debug) 204 syslog(LOG_DEBUG, "delete_invite(%"PRIu32")", id_num); 205 for (ptr = table; ptr != NIL; ptr = ptr->next) { 206 if (ptr->request.id_num == id_num) 207 break; 208 if (debug) 209 print_request("", &ptr->request); 210 } 211 if (ptr != NIL) { 212 delete(ptr); 213 return (SUCCESS); 214 } 215 return (NOT_HERE); 216 } 217 218 /* 219 * Classic delete from a double-linked list 220 */ 221 static void 222 delete(TABLE_ENTRY *ptr) 223 { 224 225 if (debug) 226 print_request("delete", &ptr->request); 227 if (table == ptr) 228 table = ptr->next; 229 else if (ptr->last != NIL) 230 ptr->last->next = ptr->next; 231 if (ptr->next != NIL) 232 ptr->next->last = ptr->last; 233 free((char *)ptr); 234 } 235
Indexes created Sun Oct 25 00:26:45 UTC 2026