1/* 2 * This file is free software: you may copy, redistribute and/or modify it 3 * under the terms of the GNU General Public License as published by the 4 * Free Software Foundation, either version 2 of the License, or (at your 5 * option) any later version. 6 * 7 * This file is distributed in the hope that it will be useful, but 8 * WITHOUT ANY WARRANTY; without even the implied warranty of 9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 10 * General Public License for more details. 11 * 12 * You should have received a copy of the GNU General Public License 13 * along with this program. If not, see <http://www.gnu.org/licenses/>. 14 * 15 * This file incorporates work covered by the following copyright and 16 * permission notice: 17 * 18Copyright (c) 2007, 2008 by Juliusz Chroboczek 19 20Permission is hereby granted, free of charge, to any person obtaining a copy 21of this software and associated documentation files (the "Software"), to deal 22in the Software without restriction, including without limitation the rights 23to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 24copies of the Software, and to permit persons to whom the Software is 25furnished to do so, subject to the following conditions: 26 27The above copyright notice and this permission notice shall be included in 28all copies or substantial portions of the Software. 29 30THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 31IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 32FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 33AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 34LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 35OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 36THE SOFTWARE. 37*/ 38 39#include <stdlib.h> 40#include <stdio.h> 41#include <string.h> 42#include <sys/time.h> 43 44#include "babel_main.h" 45#include "babeld.h" 46#include "util.h" 47#include "source.h" 48#include "babel_interface.h" 49#include "route.h" 50 51struct source *srcs = NULL; 52 53struct source* 54find_source(const unsigned char *id, const unsigned char *p, unsigned char plen, 55 int create, unsigned short seqno) 56{ 57 struct source *src; 58 59 for(src = srcs; src; src = src->next) { 60 /* This should really be a hash table. For now, check the 61 last byte first. */ 62 if(src->id[7] != id[7]) 63 continue; 64 if(memcmp(src->id, id, 8) != 0) 65 continue; 66 if(src->plen != plen) 67 continue; 68 if(memcmp(src->prefix, p, 16) == 0) 69 return src; 70 } 71 72 if(!create) 73 return NULL; 74 75 src = malloc(sizeof(struct source)); 76 if(src == NULL) { 77 zlog_err("malloc(source): %s", safe_strerror(errno)); 78 return NULL; 79 } 80 81 memcpy(src->id, id, 8); 82 memcpy(src->prefix, p, 16); 83 src->plen = plen; 84 src->seqno = seqno; 85 src->metric = INFINITY; 86 src->time = babel_now.tv_sec; 87 src->route_count = 0; 88 src->next = srcs; 89 srcs = src; 90 return src; 91} 92 93struct source * 94retain_source(struct source *src) 95{ 96 assert(src->route_count < 0xffff); 97 src->route_count++; 98 return src; 99} 100 101void 102release_source(struct source *src) 103{ 104 assert(src->route_count > 0); 105 src->route_count--; 106} 107 108int 109flush_source(struct source *src) 110{ 111 if(src->route_count > 0) 112 /* The source is in use by a route. */ 113 return 0; 114 115 if(srcs == src) { 116 srcs = src->next; 117 } else { 118 struct source *previous = srcs; 119 while(previous->next != src) 120 previous = previous->next; 121 previous->next = src->next; 122 } 123 124 free(src); 125 return 1; 126} 127 128void 129update_source(struct source *src, 130 unsigned short seqno, unsigned short metric) 131{ 132 if(metric >= INFINITY) 133 return; 134 135 /* If a source is expired, pretend that it doesn't exist and update 136 it unconditionally. This makes ensures that old data will 137 eventually be overridden, and prevents us from getting stuck if 138 a router loses its sequence number. */ 139 if(src->time < babel_now.tv_sec - SOURCE_GC_TIME || 140 seqno_compare(src->seqno, seqno) < 0 || 141 (src->seqno == seqno && src->metric > metric)) { 142 src->seqno = seqno; 143 src->metric = metric; 144 } 145 src->time = babel_now.tv_sec; 146} 147 148void 149expire_sources() 150{ 151 struct source *src; 152 153 src = srcs; 154 while(src) { 155 if(src->time > babel_now.tv_sec) 156 /* clock stepped */ 157 src->time = babel_now.tv_sec; 158 if(src->time < babel_now.tv_sec - SOURCE_GC_TIME) { 159 struct source *old = src; 160 src = src->next; 161 flush_source(old); 162 continue; 163 } 164 src = src->next; 165 } 166} 167 168void 169check_sources_released(void) 170{ 171 struct source *src; 172 173 for(src = srcs; src; src = src->next) { 174 if(src->route_count != 0) 175 fprintf(stderr, "Warning: source %s %s has refcount %d.\n", 176 format_eui64(src->id), 177 format_prefix(src->prefix, src->plen), 178 (int)src->route_count); 179 } 180} 181