Annotation of embedaddon/quagga/babeld/source.c, revision 1.1.1.1
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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