Annotation of embedaddon/quagga/babeld/source.c, revision 1.1
1.1 ! misho 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: *
! 18: Copyright (c) 2007, 2008 by Juliusz Chroboczek
! 19:
! 20: Permission is hereby granted, free of charge, to any person obtaining a copy
! 21: of this software and associated documentation files (the "Software"), to deal
! 22: in the Software without restriction, including without limitation the rights
! 23: to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
! 24: copies of the Software, and to permit persons to whom the Software is
! 25: furnished to do so, subject to the following conditions:
! 26:
! 27: The above copyright notice and this permission notice shall be included in
! 28: all copies or substantial portions of the Software.
! 29:
! 30: THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
! 31: IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
! 32: FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
! 33: AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
! 34: LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
! 35: OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
! 36: THE 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:
! 51: struct source *srcs = NULL;
! 52:
! 53: struct source*
! 54: find_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:
! 93: struct source *
! 94: retain_source(struct source *src)
! 95: {
! 96: assert(src->route_count < 0xffff);
! 97: src->route_count++;
! 98: return src;
! 99: }
! 100:
! 101: void
! 102: release_source(struct source *src)
! 103: {
! 104: assert(src->route_count > 0);
! 105: src->route_count--;
! 106: }
! 107:
! 108: int
! 109: flush_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:
! 128: void
! 129: update_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:
! 148: void
! 149: expire_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:
! 168: void
! 169: check_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: }
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