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Diffstat (limited to 'babeld/source.c')
| -rw-r--r-- | babeld/source.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/babeld/source.c b/babeld/source.c new file mode 100644 index 00000000..772112d4 --- /dev/null +++ b/babeld/source.c @@ -0,0 +1,180 @@ +/* + * This file is free software: you may copy, redistribute and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation, either version 2 of the License, or (at your + * option) any later version. + * + * This file is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + * This file incorporates work covered by the following copyright and + * permission notice: + * +Copyright (c) 2007, 2008 by Juliusz Chroboczek + +Permission is hereby granted, free of charge, to any person obtaining a copy +of this software and associated documentation files (the "Software"), to deal +in the Software without restriction, including without limitation the rights +to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +copies of the Software, and to permit persons to whom the Software is +furnished to do so, subject to the following conditions: + +The above copyright notice and this permission notice shall be included in +all copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +THE SOFTWARE. +*/ + +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <sys/time.h> + +#include "babel_main.h" +#include "babeld.h" +#include "util.h" +#include "source.h" +#include "babel_interface.h" +#include "route.h" + +struct source *srcs = NULL; + +struct source* +find_source(const unsigned char *id, const unsigned char *p, unsigned char plen, + int create, unsigned short seqno) +{ + struct source *src; + + for(src = srcs; src; src = src->next) { + /* This should really be a hash table. For now, check the + last byte first. */ + if(src->id[7] != id[7]) + continue; + if(memcmp(src->id, id, 8) != 0) + continue; + if(src->plen != plen) + continue; + if(memcmp(src->prefix, p, 16) == 0) + return src; + } + + if(!create) + return NULL; + + src = malloc(sizeof(struct source)); + if(src == NULL) { + zlog_err("malloc(source): %s", safe_strerror(errno)); + return NULL; + } + + memcpy(src->id, id, 8); + memcpy(src->prefix, p, 16); + src->plen = plen; + src->seqno = seqno; + src->metric = INFINITY; + src->time = babel_now.tv_sec; + src->route_count = 0; + src->next = srcs; + srcs = src; + return src; +} + +struct source * +retain_source(struct source *src) +{ + assert(src->route_count < 0xffff); + src->route_count++; + return src; +} + +void +release_source(struct source *src) +{ + assert(src->route_count > 0); + src->route_count--; +} + +int +flush_source(struct source *src) +{ + if(src->route_count > 0) + /* The source is in use by a route. */ + return 0; + + if(srcs == src) { + srcs = src->next; + } else { + struct source *previous = srcs; + while(previous->next != src) + previous = previous->next; + previous->next = src->next; + } + + free(src); + return 1; +} + +void +update_source(struct source *src, + unsigned short seqno, unsigned short metric) +{ + if(metric >= INFINITY) + return; + + /* If a source is expired, pretend that it doesn't exist and update + it unconditionally. This makes ensures that old data will + eventually be overridden, and prevents us from getting stuck if + a router loses its sequence number. */ + if(src->time < babel_now.tv_sec - SOURCE_GC_TIME || + seqno_compare(src->seqno, seqno) < 0 || + (src->seqno == seqno && src->metric > metric)) { + src->seqno = seqno; + src->metric = metric; + } + src->time = babel_now.tv_sec; +} + +void +expire_sources() +{ + struct source *src; + + src = srcs; + while(src) { + if(src->time > babel_now.tv_sec) + /* clock stepped */ + src->time = babel_now.tv_sec; + if(src->time < babel_now.tv_sec - SOURCE_GC_TIME) { + struct source *old = src; + src = src->next; + flush_source(old); + continue; + } + src = src->next; + } +} + +void +check_sources_released(void) +{ + struct source *src; + + for(src = srcs; src; src = src->next) { + if(src->route_count != 0) + fprintf(stderr, "Warning: source %s %s has refcount %d.\n", + format_eui64(src->id), + format_prefix(src->prefix, src->plen), + (int)src->route_count); + } +} |