1 /* $OpenBSD: carp.c,v 1.3 2009/09/30 12:22:03 claudio Exp $ */
2
3 /*
4 * Copyright (c) 2006 Henning Brauer <henning@openbsd.org>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 #include <sys/types.h>
20 #include <sys/socket.h>
21 #include <sys/ioctl.h>
22 #include <net/if.h>
23
24 #include <errno.h>
25 #include <string.h>
26 #include <stdlib.h>
27 #include <unistd.h>
28
29 #include "ospfd.h"
30 #include "log.h"
31
32 struct carpgroup {
33 TAILQ_ENTRY(carpgroup) entry;
34 char *group;
35 int do_demote;
36 int changed_by;
37 };
38
39 TAILQ_HEAD(carpgroups, carpgroup) carpgroups =
40 TAILQ_HEAD_INITIALIZER(carpgroups);
41
42 struct carpgroup *carp_group_find(char *group);
43 int carp_demote_ioctl(char *, int);
44
45 struct carpgroup *
carp_group_find(char * group)46 carp_group_find(char *group)
47 {
48 struct carpgroup *c;
49
50 TAILQ_FOREACH(c, &carpgroups, entry)
51 if (!strcmp(c->group, group))
52 return (c);
53
54 return (NULL);
55 }
56
57 int
carp_demote_init(char * group,int force)58 carp_demote_init(char *group, int force)
59 {
60 struct carpgroup *c;
61 int level;
62
63 if ((c = carp_group_find(group)) == NULL) {
64 if ((c = calloc(1, sizeof(struct carpgroup))) == NULL) {
65 log_warn("carp_demote_init calloc");
66 return (-1);
67 }
68 if ((c->group = strdup(group)) == NULL) {
69 log_warn("carp_demote_init strdup");
70 free(c);
71 return (-1);
72 }
73
74 /* only demote if this group already is demoted */
75 if ((level = carp_demote_get(group)) == -1) {
76 free(c->group);
77 free(c);
78 return (-1);
79 }
80 if (level > 0 || force)
81 c->do_demote = 1;
82
83 TAILQ_INSERT_TAIL(&carpgroups, c, entry);
84 }
85
86 return (0);
87 }
88
89 void
carp_demote_shutdown(void)90 carp_demote_shutdown(void)
91 {
92 struct carpgroup *c;
93
94 while ((c = TAILQ_FIRST(&carpgroups)) != NULL) {
95 TAILQ_REMOVE(&carpgroups, c, entry);
96 if (c->do_demote && c->changed_by > 0)
97 carp_demote_ioctl(c->group, -c->changed_by);
98
99 free(c->group);
100 free(c);
101 }
102 }
103
104 int
carp_demote_get(char * group)105 carp_demote_get(char *group)
106 {
107 int s;
108 struct ifgroupreq ifgr;
109
110 if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
111 log_warn("carp_demote_get: socket");
112 return (-1);
113 }
114
115 bzero(&ifgr, sizeof(ifgr));
116 strlcpy(ifgr.ifgr_name, group, sizeof(ifgr.ifgr_name));
117
118 if (ioctl(s, SIOCGIFGATTR, (caddr_t)&ifgr) == -1) {
119 if (errno == ENOENT)
120 log_warnx("group \"%s\" does not exist", group);
121 else
122 log_warn("carp_demote_get: ioctl");
123 close(s);
124 return (-1);
125 }
126
127 close(s);
128 return ((int)ifgr.ifgr_attrib.ifg_carp_demoted);
129 }
130
131 int
carp_demote_set(char * group,int demote)132 carp_demote_set(char *group, int demote)
133 {
134 struct carpgroup *c;
135
136 if ((c = carp_group_find(group)) == NULL) {
137 log_warnx("carp_group_find for %s returned NULL?!", group);
138 return (-1);
139 }
140
141 if (c->changed_by + demote < 0) {
142 log_warnx("carp_demote_set: changed_by + demote < 0");
143 return (-1);
144 }
145
146 if (c->do_demote && carp_demote_ioctl(group, demote) == -1)
147 return (-1);
148
149 c->changed_by += demote;
150
151 /* enable demotion when we return to 0, i. e. all sessions up */
152 if (demote < 0 && c->changed_by == 0)
153 c->do_demote = 1;
154
155 return (0);
156 }
157
158 int
carp_demote_ioctl(char * group,int demote)159 carp_demote_ioctl(char *group, int demote)
160 {
161 int s, res;
162 struct ifgroupreq ifgr;
163
164 if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
165 log_warn("carp_demote_get: socket");
166 return (-1);
167 }
168
169 bzero(&ifgr, sizeof(ifgr));
170 strlcpy(ifgr.ifgr_name, group, sizeof(ifgr.ifgr_name));
171 ifgr.ifgr_attrib.ifg_carp_demoted = demote;
172
173 if ((res = ioctl(s, SIOCSIFGATTR, (caddr_t)&ifgr)) == -1)
174 log_warn("unable to %s the demote state "
175 "of group '%s'", (demote > 0) ? "increment" : "decrement",
176 group);
177 else
178 log_info("%s the demote state of group '%s'",
179 (demote > 0) ? "incremented" : "decremented", group);
180
181 close(s);
182 return (res);
183 }
184